Research projects funded by the DFG
Current projects
2020 to 2030
Deutsche Forschungsgemeinschaft (DFG) // Land Sachsen-Anhalt
Program large-scale research equipment - Cell sorter INST 272/284-1 FUGG
Different cell types in an organism and even individual cells with identical functions within an organ differ both qualitatively and quantitatively in terms of epigenetic modifications, transcriptome, proteome and post-translational modifications. This heterogeneity also occurs in clonal cell lines. To date, our knowledge of the advantages and disadvantages of cellular heterogeneity for the robustness and plasticity of biological systems is still limited. A better understanding of the causes and consequences of cellular heterogeneity will help us to understand the potentially pathological consequences of increased or reduced heterogeneity. In addition to the inherent heterogeneity of eukaryotic cells, genetic manipulations of these cells, using methods such as CRISPR/Cas9, are another source of heterogeneity between cells. This artificial heterogeneity can influence the outcome of experiments and thus reduce the gain in knowledge. To avoid this, the isolation of defined cell types, individual cells or even single cell nuclei from primary tissues, in vitro, organ models or (genetically modified) cell lines is unavoidable in molecular biology and biomedical research. This allows 1) to understand the consequences and reasons of inherent heterogeneity in physiological and pathophysiological processes and 2) to reduce experimental artifacts due to clonal effects. Cell sorters allow the isolation of cell populations and single cells based on fluorescent markers. The isolated cells can either be cultivated further or analyzed directly., This text was translated with DeepL
2025 to 2028
Deutsche Forschungsgemeinschaft (DFG)
NMDA receptor-dependent prefrontal circuits critical for cognitive flexibility
The NMDA receptor complex is crucial for cognitive flexibility, but its clinically useful properties and potential are still largely unclear. We will, therefore, investigate the molecular and cellular properties of the NMDA receptor complex using a complementary molecular biochemical and behavioral pharmacological approach, focusing on the prefrontal cortex and associated circuits. Our aim is to find new drug targets for therapeutic intervention strategies for deficits in cognitive flexibility in aging and neurodegenerative diseases and to explore the potential of NMDA receptor-dependent circuits in a more general manner.
2025 to 2028
Deutsche Forschungsgemeinschaft (DFG)
C01 - Embodied cognitive reserve in the cortico-subcortical premotor network
In the recent past, the mechanisms that enable cognitive performance and learning to be maintained, despite age-related changes of the brain have increasingly attracted the attention of neuroscience, research. Surprisingly, however, comparatively little is known about the mechanisms underlying age-related changes in mobility and balance, despite the fact that cognitive processes depend on brain-body interactions and that a functioning motor system is an important component of successful ageing. A growing body of work demonstrated the significant impact of sensorimotor signals for precise spatial orientation - an embodied cognitive mechanism that could, for example, be exploited by sensorimotor (balance) training to maintain cognitive performance in old age. The aim of the present project is to identify the brain processes that enable some people to cope better than others with the progressive degradation of the supraspinal and musculoskeletal components of the sensorimotor system with ageing, ultimately contributing to interindividual differences in both motor performance (e.g., balance performance and learning, susceptibility to falls) and visuo-spatial cognition. To explain this behavioural heterogeneity, we propose an extension of the supply-demand mismatch theory of neural plasticity to include a “neurobiological capital” component (brain reserve) - i.e., stable (non-modifiable) structural traits that are not responsive to environmental stimuli (such as training) but still predict current performance as well as future improvements in a task (learning). We are particularly interested in the relative importance of brain reserve versus experience-induced plasticity in moderating the effects of frailty and brain ageing on postural control and associated visuospatial cognition, as well as possible interactions between these two factors. To address these questions, we will conduct a randomised, controlled balance training intervention study in older people and analyse the data in four work packages from different angles. Based on previous findings, we hypothesise that structural features of secondary motor network nodes (PMC, SMA) and their associated fibre connections play an important role in the implementation of an individual's ability to cope with sensorimotor decline. More specifically, we assume that cortical surface geometry acts as neurobiological capital (brain reserve), while training-induced changes e.g. in synaptic and myelin-related processes may represent promising, behaviourally relevant plasticity. To test these neurobiologically inspired hypotheses, we will use a combination of powerful 3T and ultra-high resolution 7T structural MRI together with state-of-the-art biophysical modelling, tractography and cutting-edge multivariate statistics. In terms of balance performance, we will use video-based human movement analysis in combination with deep learning techniques to identify behavioural patterns in balance adaptation and improvement and eventually relate these patterns to visuo-spatial performance in a concurrent cognitive task. The project promises to extend our understanding of neural plasticity by integrating insights from longitudinal training studies, multivariate (reserve) analyses, and advanced neuroimaging techniques. It stands to significantly impact the field of cognitive neuroscience related to ageing, informing precision medicine/prevention strategies to optimise the cognitive capacities of the elderly.
2021 to 2028
Deutsche Forschungsgemeinschaft (DFG)
Neural Resources of Cognition - Unlocking the Full Cognitive Potential of the Brain
In diesem Sonderforschungsbereich (SFB) wollen wir die physiologischen Prinzipien entschlüsseln, die die neuralen Ressourcen der Kognition auf mikro-, meso- und makroskalen Ebenen bei jungen und älteren Erwachsenen bestimmen. Wir werden uns individuelle Variabilität durch die Einbeziehung kognitiv überdurchschnittlicher Individuen wie z.B. "Superager" zunutze machen. Unser SFB wird somit dazu beitragen, übergreifende Theorien neuronaler Ressourcen zu entwickeln. Im Verlauf des SFB werden wir ein umfassendes Konzept der kognitiven Medizin entwickeln, welches individuell zugeschnittene Interventionen zum Schutz oder zur Verbesserung spezifischer kognitiver Funktionen umfasst und das Transferpotenzial von Interventionen optimiert. Nach dem erfolgreichen Abschluss der ersten Förderperiode wurde der SFB 1436 in die zweite Förderphase überführt und für weitere vier Jahre (2025–2028) bewilligt., www.sfb1436.de
2021 to 2028
Deutsche Forschungsgemeinschaft (DFG)
Human imaging at meso-scale
It is known from animal work that most mechanisms limiting neural resources manifest at the level of brain microstructure and influence brain functions at different hierarchical levels, such as brain macrostructure, neuronal networks, and behavioural phenotypes. Current research on neural resources in humans, however, often lacks a mechanistic level of explanation due to missing technology and/or methodological expertise needed to describe neuronal changes at the, meso-scale, (i.e. at the level of cortical layers or neuronal ensembles). This hinders knowledge transfer from mechanistic insights at the micro-scale gained in animal research to macro-scale human brain models and interventions. The CRC initiative has the overall goal to systematically investigate neural resources at the micro-, meso-, and macro-scale by taking an interdisciplinary and multi-scale approach and to link changes in the functional and structural architecture of cortical and subcortical micro-circuits to behavioural performance and cognitive interventions. Technological advancements in meso-scale brain imaging, meso-scale data modelling, and multi-modal and multi-scale data interaction can bridge this gap. The aim of, Z02, is to develop and test novel technologies using ultra-high resolution 7 Tesla magnetic resonance imaging (7T MRI) for wider applications in human subjects and primates and to provide them to the researchers of the CRC projects by ensuring (i) usage of appropriate and state-of-the-art MR-sequences that offer reproducible and optimised data quality and (ii) computational tools and analysis pipelines for multi-modal and multi-scale data modelling within and across individuals., Z02, has the overarching goal of modelling the human cortex in three dimensions, that is, both in plane at the cortical surface (dimensions 1&2) and in cortical depth (dimension 3, cf. Kuehn & Sereno 2018, Fig. 1). This approach extends the frequently applied localisation of function in cortical regions, e.g. Brodmann areas, or more advanced and ambitious columnar mapping, to a novel level of detail relevant for cognitive processes (e.g., Larkum et al. 2018). This will allow the CRC projects to target research questions on neural resources in a novel yet undiscovered dimension, while at the same time enabling Magdeburg to maintain its leading position for human brain imaging in Europe.
2025 to 2028
Deutsche Forschungsgemeinschaft (DFG)
Restoring neural resources perturbed by sleep deprivation (SFB 1436, C04)
Aging as well as many psychiatric disorders are characterized by a decline in cognitive functions due to a lack of neural resources but these effects are difficult to isolate. Therefore, in this project we’ll use sleep deprivation in healthy young adults to induce a transient functional loss of resources. This model will be used to better understand how the cognitive control network deals with resource availability and to potentially identify approaches to improving cognitive performance when resources are reduced.
2024 to 2028
Deutsche Forschungsgemeinschaft (DFG)
Adaptive pore network modelling and experiments of thermochemical processes in single porous particles
A crucial component in the development of DEM/CFD computational tools to describe the thermochemical behaviour of bulk solids are the single particle models for DEM. Only with accurate single particle models, particle conversion and/or particle product qualities can be reliably predicted at the outlet of industrial reactors. The complexity in the description lies in the fact that at particle scale chemistry and transport compete at similar time scales., Project B4 is driving the advancement in the modelling of reactive processes at particle level, with a primary focus on biomass pyrolysis and char conversion as model reactive systems in FP2. Biomass conversion has been selected as it can serve as a highly complex model system for DEM single particle models including heterogeneous reactions, change of particle shape and pore structure, as well as anisotropic intra-particle transport properties. As methodological approach to develop sophisticated single particle models, a novel, one-of-a-kind simulative-experimental framework will be derived. This framework will be sustained on three pillars: the development of adaptive pore network models (PNM), the parametrisation of continuum models (CM) based on effective transport, chemical, and morphological properties derived from the highly resolved PNM simulations, and the provision of measurement data that facilitate the bridging of scales from PNM to CM.
2020 to 2028
Deutsche Forschungsgemeinschaft (DFG)
Lattice Boltzmann simulations of reacting flows in small-scale static and moving beds of particles with complex shapes
he central objective of this project is to improve our basic understanding of physicochemical pro- cesses occurring at the micro-scale in particle beds including chemical reactions involving a gas phase. The gain in insight into this problem will provide fundamental guidance in the development of reduced models, suitable for simulations of the large-scale process. The shape and arrangement of particles in the bed control the resulting flow and, thereby, the final outcome of the chemical re- actions. Boundary effects and dispersion processes are important concerning pressure drop as well as species and heat transport. All relevant aspects will be taken into account during this project for typical beds of small dimensions: complex, non-spherical particle shapes; particle movement; un- steady flow - from the laminar to the low-turbulence regime; detailed kinetics and species transport. For this purpose, a Lattice Boltzmann simulation model (LBM) will be developed and applied as a tool for Direct Numerical Simulation (DNS) of reacting flows in complex geometries.
2024 to 2028
Deutsche Forschungsgemeinschaft (DFG)
Modeling the effect of authenticity and perceived complexity on situational interest, interest in scientific activities, and cognitive learning outcomes in the context of magnetic elastomers
This project investigates the influence of authenticity on interest in the context of magnetic elastomers, considering the interaction between objective complexity and subjectively perceived cognitive load. Authenticity, defined as the degree of realistic representation of contexts, has been recognized as a crucial factor in promoting interest. However, the mechanisms through which authenticity affects interest, particularly considering the role of complexity and cognitive load, are still insufficiently explored., To address this research gap, an expanded theoretical framework is developed, integrating existing models of interest, cognitive load theory, and authenticity. This framework guides the design of empirical studies that examine the causal relationships between authenticity, complexity, interest, and cognitive learning outcomes. The focus is on using original visualizations to communicate the results from the involved research groups., The mixed-methods approach includes quantitative surveys using questionnaires and eye-tracking procedures, as well as qualitative interviews. Participants will be recruited from high school and engage in scientific activities involving magnetic elastomers at OVGU Magdeburg and TU Dresden. Eye-tracking data from a smaller sample will be collected to examine the cognitive processing and complexity of the learning materials. Statistical analyses of pupil size and saccades provide insights into cognitive load and information processing during learning., Data analysis will involve statistical modeling techniques such as structural equation modeling, hierarchical regression, and analysis of eye-tracking data. This allows for investigating the complex interactions between authenticity, complexity, interest, and cognitive processing, with eye-tracking data supporting the perception of complexity. Qualitative interview data will be thematically analyzed to provide a deeper understanding of underlying processes and mechanisms., The expected outcomes of this project include a refined understanding of how authenticity influences interest, considering complexity and subjectively perceived cognitive load. The results contribute to the development of evidence-based strategies for designing authentic learning environments that promote interest, optimize cognitive processing, and improve cognitive learning outcomes. Additionally, the empirical findings provide a foundation for future research in the field of situated learning and instructional design.
2024 to 2028
Deutsche Forschungsgemeinschaft (DFG)
Experimental investigation of flow fields in the interstices of bulk particles using optical measurement techniques
The flow behaviour of the gas phase in a packed bed has important effects on mass and energy transport processes that are taking place in the bed. It is hence also a central parameter for process optimisation of such systems. Currently, however, only very limited data on the gas flow in packed beds exists, since the access to the particle interstices is very challenging with both probe-based and optical measurement methods. Furthermore, the existing results were typically obtained using refractive index matching, and are hence limited to liquids. For gaseous flows, mainly conclusions obtained using similarity theory are available, which limits the potential range of application., In the first funding period of this project, we extended optical particle image velocimetry (PIV) of the velocity fields in the gas phase within packed beds by ray tracing reconstructions. For this, we used beds consisting of transparent bulk material so that the velocity field determination can be aided with a numerical simulation of light propagation through the bed. The simulation was performed with ray tracing, and the resulting information was used to correct the raw PIV particle images of the flow. This technique then allowed for the direct measurement of velocity fields in the gas phase of transparent packed beds., The main emphasis in the second funding period will be on extending the optical measurements to other quantities, such as temperature and dispersion. Also a new experimental configuration will be used that consists of parallel transparent bars arranged in rotatable layers modelling a polyhedral packing. It will be far less regular than the reference configuration of FP1, while still providing direct optical access without considerable optical distortion, ., Simultaneous measurements of gas temperature and velocity will be performed using thermographic phosphor particles. Further, laser induced fluorescence (LIF) of Anisole will be used for the determination of gas dispersion in the packed bed. The multi-camera set-up from FP1 will be further extended to a matrix arrangement of the cameras for the acquisition of three dimensional three component (3D3C) velocity and simultaneous temperature fields in the interstices of the new reference configuration. A systematic evaluation of refractive index matching for the use in complex, also moving transparent packed beds will be done on the basis of dimensional analysis to compare results from liquid and gaseous flows. These results will be of particular interest for FP3 when moving beds will be considered., After the development of the aforementioned measurement methods, the proposed approach will enable an effective determination of concentration/dispersion, temperature and gas flow velocities in the packed bed. A wide range of parameters, such as packing density, packing size, inflow type and direction can be explored in this way. The measured data will then be used in other projects, e.g. to validate numerical calculations or for model development, especially concerning dispersion and heat transfer. Furthermore, the data provided is spatially and temporally highly resolved, allowing for the derivation of turbulence quantities for further processing and use in the partner projects.
2020 to 2028
Deutsche Forschungsgemeinschaft (DFG)
Contact heat transfer and heat conduction in packed beds of edged particles
A central parameter of thermal DEM is the particle-particle heat transfer coefficient during binary contacts. Contact heat transfer is important for thermochemical processes in particle systems, but, commonly calculated by simplified models, the validity of which is questionable even in case of equally sized spheres. Any reliable background is missing in case of polyhedral particles, despite of many applications in practice. The project aims at a new and more reliable way of predicting the heat transferred when particles come for a certain period of time in contact with each other from effective packed bed thermal conductivity. Therefore, effective packed bed thermal conductivity investigated by experiments and simulations for a wide range of different polyhedral particles. On this basis new correlations for the prediction of effective thermal conductivity for arbitrary materials that consist of polyhedron-like particles are developed. The transition to particle-particle heat transfer coeffiecients is calibrated by experiments in a small rotary drum. Binary mixtures of particles that differ in size, shape, or conductivity are also considered. Packed bed porosity and the relative area of flat interparticle contacts is derived from X-ray µ-CT imaging results. Interstitial packed bed morphology, including pore size variability, is considered.
2023 to 2028
Deutsche Forschungsgemeinschaft (DFG)
SFB 287 FP2 Bulk Reaction - Subproject C5
The aim of project C5 is to develop, derive and validate new models for a more precise coupling between fluid and particles in DEM/CFD frameworks, taking into account the heterogeneous and anisotropic structure of local particle packings. To this end, resolved simulations of particle packings are performed that include: i) particles with varying size distributions, ii) non-isothermal flows, and iii) moving particles. These extensions represent a natural evolution of our numerical tools and are of high relevance to the DEM/CFD research community., This text was translated with DeepL
2023 to 2028
Deutsche Forschungsgemeinschaft (DFG)
SFB 287 FP2 Bulk Reaction - Subproject C2
Flow mixing, heat transfer and chemical reactions in fixed bed and moving bed reactors. The C2 project investigates jet propagation in fixed-bed and moving-bed reactors, which are important for numerous applications in the chemical and energy process industries, e.g. in fixed-bed catalytic reactors, pellet boilers, shaft furnaces and grate firing systems. The experimental results are compared with numerical simulations to validate and to quantify errors in the different averaging approaches of DEM/CFD modeling. In addition, PR-DNS and DEM/CFD simulations will be continued with the new particle configurations from FP2 to identify errors in existing DEM/CFD approaches and develop improved averaging methods. These simulations also address heat transfer and contribute to the further development of the DEM/CFD framework., This text was translated with DeepL
2024 to 2028
Deutsche Forschungsgemeinschaft (DFG)
SFB-TRR 287 A2: 3D-Measurements in dense granular assemblies using hyperpolarised Magnetic Resonance Imaging
Research areas, Biomedical Technology and Medical Physics (205-32), Biomedical System Technology (407-06), Due to the limited accessibility of the bulk material to direct detection methods, often only integral flow quantities can be measured at the inlet and outlet of packed bed reactors. The exact understanding of the processes inside these technical systems is, thus, just as difficult as the system design with regard to energy efficiency and product quality. Furthermore, predictions from simulations cannot be experimentally validated in detail. Therefore, in project A2 the three-dimensional (3D) velocity field of the gas flow will be first measured in the reference configuration of the CRC/TRR with spherical and complex shaped particles by means of hyperpolarised phase contrast magnetic resonance imaging (pc-MRI). Three-dimensional, temporally and spatially resolved flow maps of the entire gas volume will be generated. These flow field data are essential and form the basis for the further understanding of the homogeneous and heterogeneous chemical reaction rates in particle beds. Sensors or tracer particles, which in turn can perturb the flow and particle movement, are not required. Optical access is also not necessary and arbitrary geometries are possible. The high flexibility of pc-MRI allows adaptations of the measurement to the requirements, e.g. regarding the sample volume (up to about 40 x 40 x 40 cm in commercial MRI) and the spatial (approx. 1 millimetre) or temporal resolution (approx. 1/10 second). With established MRI methods, usually only liquids can be detected due to their favourable physical properties with regards to generation of magnetisation (also called spin polarisation) and its life-time (relaxation properties). In this project, the transition to gaseous media is made possible by the application of highly innovative hyperpolarisation techniques. With this, the comprehensive three-dimensional, quantitative measurement of gas flow fields in complex geometries of non-transparent particle beds will be possible for the first time. Therefore, in addition to hyperpolarisation of the gas, MRI flow measurement methods for hyperpolarised magnetisation must be established. In addition, the development of materials and measurement setups is required that support the use of hyperpolarised gases without interference with the high spin polarisation. A2 will, therefore, build a continuous flow Xenon hyperpolariser with sufficient flow and polarisation level for fast and accurate MRI detection of gas (WP 1), a Xe-coil for Xe-MRI (WP 2), select and characterise proper materials for building an MR-compatible reference experiment (WP 3), extend a table to MR system for Xe-capability (WP 4), develop 3D pc-MRI flow measurement method for the application in hyperpolarised gas systems (WP 5) and measure and process flow data from the reference configuration (WP 6) to be provided to the simulation projects and to be compared to the other experimental methodology.
2024 to 2028
Deutsche Forschungsgemeinschaft (DFG)
Stability, Accuracy and Efficiency in Hybrid Finite Element / Neural Network Simulations
The solution of partial differential equations is a central subject of numerical analysis and an indispens- able tool in science and engineering. Existing approaches, such as finite elements, can provide solutions efficiently and robustly in many applications. Deep neural networks, nonetheless, emerged in the last few years as an alternative approach with promising results. Techniques that are completely or partially based on neural networks, however, currently lack the mathematical guarantees and insights available for estab- lished approaches. Furthermore, their relative performance and practical robustness in applications is at the moment unclear, even in the case of standard problems such as those from three dimensional fluid mechanics., In the proposed project, we will work towards a mathematical theory for numerical techniques that combine finite elements and deep neural networks for the solution of partial differential equations. Informed by our preliminary work, our hypothesis is that a combination of (adaptive multigrid) finite elements with deep neural networks can provide a computationally more efficient and more accurate solution than either approach alone. Concretely, we will consider the Stokes and Navier-Stokes equations and the neural networks will represent fine scale behavior not resolved by a finite element solution. The networks will be trained using high-resolution reference data, which was sufficient to attain accurate and efficient solutions of standard flow problems in 2d and 3d in our preliminary work. We will therefore not pursue physical or mathematical constraints on the solutions, as, e.g., in PINNs, and consider it an important but orthogonal research direction to our planned work. Although it is a central objective of the proposed project to develop mathematically rigorous analyses, we consider it also as important to study the practicality of our results through implementations. As part of the project, a research code for hybrid fluid flow solvers in 2d and 3d will therefore be implemented and made publicly available at the end of the project., We will build on recent work that showed that the mathematical analysis of deep neural networks is possible using tools that have been developed for the analysis of finite element methods. We will extend these results to numerical time stepping schemes for the Stokes and Navier-Stokes equations that combine a classical discretization with neural networks and consider practically relevant setups in 2d and 3d, e.g. by including relevant boundary conditions. We will also extend existing results to state-of-the art network architectures used in the machine learning literature, e.g. transformers. These are one of the most powerful architectures used in practice and at the same time well suited for scientific computing and a mathematical analysis., The first questions we want to address in the proposed project are stability and accuracy of the hybrid simulations, i.e. that they remain bounded and that a neural network is able to improve the accuracy. For a hybrid solver, this requires, among other things, neural networks that are stable for admissible inputs but also a coupling to the finite element part that preserves the stability. Second, we will explore adaptive solution schemes where a posteriori or neural network-based error estimates are used to refine a solution if necessary to meet pre-defined error criteria. We believe that the results obtained in the proposed project will also be of relevance for a more complete theory for neural network-based simulations.
2024 to 2028
Deutsche Forschungsgemeinschaft (DFG)
FOR 5599: From the manufacturing process of structured magnetic elastomers to macroscopic material behavior
Coordination fund, For a description of the project, see GEPRIS (, https://gepris.dfg.de/gepris/projekt/535421963, ):, "Magnetic gels and elastomers consist of magnetic colloidal particles embedded in a soft, elastic carrier medium. The promising properties of these materials include in particular magnetorheological effects, i.e. changes in mechanical properties in external magnetic fields, and magnetostriction, i.e. deformations induced by magnetic fields. Numerous experimental and theoretical studies have shown that the internal structuring, given by the arrangement of the magnetic particles in the elastic carrier medium, has a significant influence on these effects. Several steps are necessary to pave the way for these promising materials in applications. So far, the internal structuring in the production of magnetic elastomers has mainly been carried out with the help of external magnetic fields. We need to understand and quantify the processes involved in structure formation at the particulate level. Building on this, we are investigating how structure formation can be influenced and controlled by suitable process control. At the same time, it is necessary to quantitatively work out the links between the resulting particulate structures and macroscopic material behavior. On this basis, structures can be identified that maximize the desired macroscopic properties. This reveals the actual potential of the materials. We check whether corresponding structural elements are already contained in real samples. In the medium to long term, new methods will be developed to produce optimized systems with the desired material behavior. To ensure that the fascinating properties of magnetic elastomers are ultimately taken up for practical purposes, we are communicating them even more to a broader public. Pupils and teachers are a key target group. We are therefore planning didactic studies, including the development and evaluation of appropriate teaching and learning materials for school lessons. On the other hand, we are carrying out numerous outreach activities accompanied by subject-specific didactics. In this way, we want to get the public interested in current research and, in particular, schoolchildren interested in studying engineering and science. To work on the interdisciplinary project, we combine numerous complementary approaches, for example experimental investigations on different length scales, dynamic particle-resolved simulations, cross-scale simulations, structural analyses, different visualization methods, didactic investigations and outreach activities. We have broad expertise and a wide range of successful preliminary work in these areas. It is therefore very important to us to further advance the research and dissemination of these fascinating materials.", (DFG procedure research groups), This text was translated with DeepL
2025 to 2028
Deutsche Forschungsgemeinschaft (DFG)
Kurze Polynome finden
This project concerns the number of terms of polynomials as a complexity measure., This is an area of commutative algebra that is much less explored than degree based, complexity measures like Castelnuovo–Mumford regularity. As the finiteness results, that drive the Gröbner machinery are based on induction on the degree, they often, need to be replaced by more synergetic tools to make progress here. We envision that, combinatorial data structures like Newton polyhedra and matroids will help us to, solve the fundamental problem of this project: Is it algorithmically decidable if an, ideal in a polynomial ring contains a short polynomial?
2024 to 2028
Deutsche Forschungsgemeinschaft (DFG)
Magnetically induced particle dynamics and particulate structure formation in viscous and viscoelastic media - theoretical-numerical investigations
For a description of the project, see GEPRIS (, https://gepris.dfg.de/gepris/projekt/535543971, ):, "Magnetic gels and elastomers consist of magnetic or magnetizable colloidal particles embedded in a soft, elastic, polymeric medium. The fascinating properties of these materials include, for example, mechanical stiffness, which can be significantly and clearly altered by external magnetic fields, and magnetically induced, actuator-like deformations. Such characteristics strongly depend on the spatial arrangement of the particles, which remains permanently fixed by the surrounding elastic medium. Here, anisotropic elements such as chain-like particle aggregates can arise if strong external magnetic fields are applied during material production. We want to investigate and understand the dynamics of such processes of structure formation from particles during production. This involves the interplay of anisotropic magnetic and hydrodynamic interactions between the particles. Through their displacement, individual particles set the surrounding medium in motion and thus influence the configuration of the other particles. In particular, we also want to analyze the effects of viscoelastic properties of the medium on these particle dynamics. The transition from an originally viscoelastic-fluid to an elastic medium will be mapped. Additional parameters to be investigated are particle concentration, magnetic field strength, particle shape and particle polydispersity in shape and size. The project requires the implementation of a numerical method that couples the discrete particle motion to the dynamics of the surrounding viscoelastic medium and allows a mutual approximation of the particles to quasi-contact. We pursue a close exchange with the other groups of the research group, which carry out corresponding particle- and time-resolved experimental measurements, produce and analyze corresponding macroscopic materials, develop scale-bridging simulation methods and investigate teaching-learning possibilities for conveying our content in a didactic school context. The common goal is to develop methods for generating the most advantageous structures of particles possible, which lead to optimized macroscopic material properties, and to bring our content closer to a broad public in the context of outreach activities. In addition, the sub-project motivated here has much more general relevance. It generally concerns the collective dynamics of discrete particles in viscoelastic environments. A current example that is currently attracting a great deal of attention is the movement of active microswimmers. Their dynamics can already change qualitatively for individual objects due to the viscoelasticity of a surrounding medium.", (DFG procedure research groups), This text was translated with DeepL
2025 to 2027
Deutsche Forschungsgemeinschaft (DFG)
Das Hippocampus - präfrontale Kortex - vordere olfaktorische Nukleus Netzwerk und seine Bedeutung für den kognitiven und sensorischen Leistungserhalt während des gesunden Alterns
Das GRK2413 SynAGE bildet Doktoranden in interdisziplinärer und translationaler Forschung zu den synaptischen Mechanismen gesunden Alterns aus. Mein Projekt wird die Auswirkungen cholinerger Dysfunktion auf den vorderen olfaktorischen Nukleus und seine Kommunikation mit präfrontalem Kortex und Hippocampus darin untersuchen. Es wird die Infrastruktur und das Qualifizierungsprogramm des GRK ergänzen, umfassende Expertise in Neurophysiologie und Optogenetik einbringen und das Forschungsspektrum mit Blick auf den Zusammenhang zwischen sensorischen Wahrnehmungsstörungen und kognitivem Altern erweitern .
2023 to 2027
Deutsche Forschungsgemeinschaft (DFG)
Research Training Group RTG 2413 SynAGE: “The Ageing Synapse: Molecular, Cellular and Behavioural Underpinnings of Cognitive Decline”
The RTG2413 SynAGE is designed to provide doctoral researchers with training in cross-disciplinary approaches in the analysis of CNS function and state-of-the-art methodology that allows to address ageing-related changes at the level of protein synthesis, synaptic signals, and neural networks. Our innovative approach focusses on clarifying the mechanisms underlying “healthy” synaptic ageing and aim at scrutinizing endogenous mechanisms for maintaining synaptic functions as targets of intervention.
2022 to 2027
Deutsche Forschungsgemeinschaft (DFG)
GRK 2413/2 SynAGE TP E2 - "Cholinergic mechanisms underlying novelty detection and novelty responding - key for maintaining emotional and cognitive health in aging"
Compelling evidence suggests that acetylene choline is an important modulator of synaptic plasticity in cerebral cortex and hippocampus. Normal ageing is accompanied by a gradual loss of cholinergic function involving structural and functional alterations at the dendritic, synaptic and axonal level. Such hypofunction of the cholinergic system in the absence of overt neurodegeneration has been associated with age-related functional decline in the brain including ageing-associated cognitive impairments.Muscarinic M1 receptors (M1R), which are spared from ageing-induced loss of expression in hippocampal and neocortical regions, can be considered a target of choice for treatments alleviating cognitive decline. Based on our previous work we hypothesise that M1R critically control DG circuits mediating novelty detection. Maintaining cholinergic functionality function in these circuits via M1R may be a key to improve cognitive flexibility, memory and emotional state during ageing. Therefore, we will examine the M1R-dependent functional changes in dentate gyrus / CA3 local circuits during ageing and their effects on novelty detection and cognitive flexibility. In the first PhD project, we will investigate the specific role of M1R in the local circuitry of the dentate gyrus using viral intervention and engram labelling tools. The second PhD project will focus on network activity patterns underlying pattern completion, novelty responding and working memory in ageing mice. We will cooperate with our partners in this squad by investigating the role of the calcium binding protein calneuron in M1R mediated functions and potency of their pharmacological modulation in recovering novelty detection and cognitive functionality during ageing.
2023 to 2027
Deutsche Forschungsgemeinschaft (DFG)
RTG 2414/2 TPA2 "Mechanotransduction and the ageing synapse"
The accumulation of extracellular matrix molecules in the brain during aging leads to altered gene expression and proteostasis and thus to disruption of synaptic functions and synaptic plasticity in particular. We postulate that by modulating the mechanotransduction signaling pathways involved in these processes, age-induced loss of function in the brain can be counteracted, and that the endogenous compensatory mechanisms investigated in this project can be used to develop new pharmacological treatment strategies., Specifically, we will test the hypothesis that the protective effect of switching off Ndr2, Kinase in the aging brain, as observed in the first funding period of our RTG, is associated with such altered mechanotransduction. To this end, we will determine changes in the expression of synaptic proteins in the hippocampus of young and old Ndr2 mutant mice and the effect of targeted viral and/or pharmacological manipulation of the mechanotransduction pathways on synapse density, on synaptic transmission and plasticity, and on hippocampus-dependent learning , as well as investigate the cellular processes involved in these effects.
2023 to 2027
Deutsche Forschungsgemeinschaft (DFG)
RTG 2413: The aging synapse
Our Research Training Group 2413 is an innovate research program funded by the DFG. We - 13 PhD students and their PIs - are dealing with the idea that cognitive decline in normal aging results from synaptic dysbalances. Hence, we are highly motivated to shed more light on altered synaptic proteostasis, dysfunctions of the immune system, altered functionality of the multipart synapse and changes in neuromodulation.
2024 to 2027
Deutsche Forschungsgemeinschaft (DFG)
GRK 2413: The aging synapse
Our Research Training Group 2413 is an innovate research program funded by the DFG. We - 13 PhD students and their PIs - are dealing with the idea that cognitive decline in normal aging results from synaptic dysbalances. Hence, we are highly motivated to shed more light, on altered synaptic proteostasis, dysfunctions of the immune system, altered functionality of the multipart synapse and changes in neuromodulation.
2025 to 2027
Deutsche Forschungsgemeinschaft (DFG)
Improving simulations of large-scale dense particle-laden flows with ma- chine learning: a genetic programming approach
Particle-laden flows are encountered in many natural and industrial processes, such as, for instance, the flow of red and white blood cells in plasma, or the fluidization of biomass particles in furnaces. Over the last 40 years, scientists have used Euler-Lagrange (EL) simulations as a way to predict the behavior of such flows. However, EL simulations rely on models to describe the interaction between the fluid and the individually tracked particles. These models require the so-called "undisturbed” fluid velocity at the location of the particle, which is what the velocity of the fluid would have been if the particle had not been there. Current models for this are very rudimentary and precisely calculating the undisturbed fluid velocity is extremely expensive, as it would involve running many additional highly resolved simulations of the same case where one particle is left out., This is a project to deliver a novel model for the undisturbed fluid velocity at each particle location, given the properties of the flow around the particle and of the surrounding particles, using a supervised learning machine learning approach: genetic programming (GP). GP is highly suitable, as its result will not be a "black-box” model, but a verifiable expression for the undisturbed velocity. This expression will be validated by analytical solutions and highly resolved simulations, and will enable accurate, large-scale simulations of dense particle-laden flows, while only requiring a fraction of the cost of fully resolved simulations.
2023 to 2027
Deutsche Forschungsgemeinschaft (DFG)
Microvascular and synaptic plasticity in aging
Ageing is related to a dynamic process of ongoing microvascular injury, such as blood-brain barrier disruption, impaired hemodynamics and clearance, i.e., removal of brain protein and metabolite waste products. These processes ultimately lead to synaptic and neural network dysfunction, but could be counterbalanced by continuous microvascular repair, which in turn should be related to maintenance of synaptic and network functioning. We propose, that balance between microvascular injury and repair as well as resistance against microvascular injury in response to physiological stimuli cumulatively fail with increasing age (denoted as “microvascular brain aging”), which feeds into reduced cognitive flexibility and function., Hence, in close interaction with project B1, we aim to study in rodents (B1) and humans (B2) cortical and hippocampal synaptic function and network connectivity as a function of “microvascular brain ageing”. We specifically focus on the question, how this relationship is influenced by age-related reduced microvascular resistance against physical stress or prolonged recovery. We further particularly investigate how age-related impaired microvascular resistance/recovery and associated declined synaptic and network function can be restored through targeted pharmacological treatment.
2024 to 2027
Deutsche Forschungsgemeinschaft (DFG)
Untersuchungen zur Ambivalenz des AHR-Signalweges in Haut-krankheiten
Melanoma, the most lethal type of skin cancer, accounts for almost 2% of cancer cases worldwide, with an increasing incidence due to the unbroken trend of recreational UV exposure. The aryl hydrocarbon receptor (AHR), a ligand binding transcription factor of the basic helix-loop-helix Per-ARNT-Sim family, was initially described as the receptor for the dioxin TCDD and has been shown to mediate the detoxification of environmental pollutants. More recently, a multitude of physiological and endogenous ligands have been discovered, along with increasing evidence of physiological roles of AHR in cell proliferation, differentiation and inflammatory responses. UV light has been shown to generate the high affinity AHR agonist FICZ that promotes skin tanning as a protective response against UV. However, in cancer cells AHR activation promotes tumor progression. The current project is based on the hypothesis that AHR signaling promotes protective melanocyte responses to UV irradiation in physiological settings, whereas in pathologic settings, AHR signaling enhances malignant transformation as well as metastatic progression and impairs the efficacy of T cell directed immunotherapies. In the first work package of the project, we will use melanocyte-specific, conditional AHR knockout mice to characterize the impact of AHR signaling on the response of melanocytes to UV light. Additionally, we will also analyze the role of AHR signaling on UV-induced tumor development and progression by utilizing the Hgf-Cdk4 melanoma model crossed with the melanocyte-specific AHR knockout mice. In the second work package, we will assess the role of AHR signaling on immunotherapy. For this, we will use our transplantable melanoma cell line HCmel12 with and without a CRISPR mediated AHR knockout and perform adoptive T-cell transfer. Furthermore, we will also combine adoptive cell transfer therapies with pharmacological AHR inhibition in mice transplanted with HCmel12 melanoma cells to assess the future prospect of therapeutic AHR inhibition in man. In the third work package, we will characterize the AHR signaling dynamics in melanocytes and melanoma cells, in vitro, . Subsequently, we attempt to analyze the impact of AHR signaling on inflammation-induced melanoma cell plasticity and unravel the underlying molecular mechanism. In the final work package, we will analyze the impact of AHR signaling on the dynamics of melanoma cell transcriptional plasticity in response to inflammatory and therapeutic stimuli via single cell RNA sequencing. Additionally, we will also characterize AHR signaling on the differentiation trajectories of cutaneous melanocytes and melanoma cells following UVB irradiation. We expect that the insights gained from this project will provide a rationale for the future therapeutic modulation of AHR signaling in the treatment of melanoma.
2023 to 2027
Deutsche Forschungsgemeinschaft (DFG)
Selection, design and application of novel biocatalytic reactive crystallization concepts for the preparation of chiral beta-amino alcohols and alpha-amino acids
This it the sub project of the DFG research unit 5538 (Multistep Catalytic Production Systems for Fine Chemistry by Integrated Molecular, Material and Process Design (IMPD4Cat)), The primary goal of this subproject is to develop an efficient combination of biocatalytic reactions and selective crystallization procedures for the synthesis of chiral beta-amino alcohols and alpha amino, acids on a preparative scale. The project builds on the investigation of the fundamental physicochemical properties of the target compounds, which are to be isolated directly from aqueous reaction solutions. In parallel, the decision on the selection and use of suitable biocatalysts or their corresponding preparations is relevant for the selection of the integrated reaction route, since the corresponding reaction conditions have an influence on the solubilities of the target compounds. For amino acids, direct crystallization under the selected crystallization conditions is preferred, whereas suitable, crystallization agents are required for amino alcohols to crystallize these often hydrophilic products in the form of a salt. Process control will be supported by the integration of suitable concepts for process, analytical technology (PAT) including automated liquid chromatographic methods for real-time monitoring, control and optimization of the integrated biocatalysis-crystallization process. In, the combination of all the processes described above, the process is to be optimized and scaled up to preparative scale in the sense of a pilot plant.
2024 to 2027
Deutsche Forschungsgemeinschaft (DFG)
Optimal Design for Thurstonian IRT Models
The main aim of the present project is the development of optimal designs for Thurstonian IRT modes in the case of metric, binary, or ordinal responses which provide a sufficiently good estimation of the trait scores. In addition, binary paired comparisons will be considered which are derived from ranking more than two alternatives. In the present situation, optimal designs are characterized by combinations of those values of item parameters, factor loadings and intercepts which optimize prior determined criteria, as correlation between estimated and true trait scores. In order to apply these models in the selection of personnel, only positive factor loadings are admitted. This condition is supported by simulation studies and requires the development of novel types of optimal designs. Beyond properties of optimal designs developed in the literature so far, three more requirements have to be particularly taken into account: (a) the specific form of the non-linearity, (b) the restriction of the design region, and © the constraint that alternatives have to load on mutually distinct factors, respectively. To implement the findings of the project in practical applications, a user-friendly program in R is to be developed using a shiny app.
2024 to 2027
Deutsche Forschungsgemeinschaft (DFG)
Exploiting GaN Devices for Drive Inverters and Drive Inverters for GaN Devices (DriveForGaN)
The project pursues a holistic design approach to make use of packaged Galliumnitride (GaN) power devices in drive converter systems. The aim is to show under which boundary conditions the use of GaN power semiconductors in drive inverters is possible and to assess which prospects would result out of it. Electric drives are a high-volume application that has not yet been able to benefit from GaN and its advantageous properties such as low losses contributing to increased efficiency., Major research questions concern the evaluation of the effect of GaN devices on system behaviour, the evaluation of required measures and methods to use GaN devices in such drive converters, in particular with reference to control and protection of the devices in the converter legs, circuit and control of the power section and the machine interface respectively. These topics obviously interact with each other and should be considered with the proposed holistic approach, comprising theoretical and simulative investigations as well as an experimental validation.
2024 to 2027
Deutsche Forschungsgemeinschaft (DFG)
Automated Segmentation and DIscrimination for Intracranial Aneurysms (AI4IA): Enhancing Robustness of Clinical Risk Scores based on Morphology and Hemodynamics
Rupturierte intrakranielle Aneurysmen (IAs) sind die Hauptursache für Subarachnoidalblutungen, welche zu schweren Behinderungen oder zum Tode führen können. Die Versorgung von noch unrupturierten IAs, welche vergleichsweise häufig auftreten, stellt eine Herausforderung dar, da es zahlreiche Unsicherheiten bezüglich der individuellen Prognose, der optimalen Therapiestrategie sowie möglicher Behandlungskomplikationen gibt. Morphologische und hämodynamische Parameter können hier einen Beitrag zur Risikostratifizierung leisten, sind jedoch aufgrund mangelnder Robustheit bisher klinisch wenig verbreitet. Hauptziel des AI4IA-Projekts ist es, im Rahmen des SPP2311 Unsicherheitsquellen in der Bestimmung morphologischer und hämodynamischer Parameter der Ruptur Risiko zu identifizieren und zu reduzieren, um die Translation in die Patient:innenversorgung zu ermöglichen. Dazu sind folgende Hauptaufgaben geplant: • Untersuchung möglicher Unterschiede in der Bilddatenerfassung zwischen zwei klinischen Standorten sowie Aufbau einer Datenbank mit realen IA-Geometrien. • Entwicklung von Standardarbeitsanweisungen für die Bilddaten- und Geometrieverarbeitung, die Blutflusssimulation sowie die Bestimmung der morphologischen und hämodynamischen Parameter. • Identifikation geeigneter Open Source Tools für die einzelnen Arbeitsschritte, damit der Workflow von Dritten möglichst einfach reproduziert werden kann. • Automatisierung der Geometriesegmentierung mit Hilfe künstlicher neuronaler Netzwerke sowie der anschließenden Analyse morphologischer und hämodynamischer Parameter. • Beurteilung der Unsicherheit morphologischer und hämodynamischer Parameter, die mit Hilfe von Machine-Learning-Lösungen erfasst wurden, im Vergleich zur manuellen Segmentierung. • Identifikation eines optimalen Satzes robuster morphologischer und hämodynamischer Parameter, um unrupturierte von rupturierten IAs zu unterscheiden. Außerdem Identifikation von gemeinsamen Eigenschaften, die robuste Parameter auszeichnen. Das Projekt ist als erster Schritt zur Entwicklung robuster Rupturrisiko-Vorhersagesysteme konzipiert und auf eine Dauer von 36 Monaten im Rahmen der zweiten SPP2311-Phase angelegt. Es ist als Kooperationsprojekt zwischen den auf neurovaskuläre Fragestellungen spezialisierten Forschungsgruppen in Berlin und Magdeburg geplant, wobei jede Forschungsgruppe von einem klinischen Partnerstandort unterstützt wird. Die Forschungsgruppen haben langjährige Erfahrung in der Modellierung von IAs, während die klinischen Partnerstandorte über entsprechende klinische Expertise verfügen und Geometrien realer IAs in pseudonymisierter Form bereitstellen.
2021 to 2027
Deutsche Forschungsgemeinschaft (DFG)
Bile acid receptors and their role for maladaptive processes in cholangiocytes and biliary diseases
Biliary tract cancer, also known as cholangiocarcinoma (CCA9, accounts for about 2% of all malignancies, but incidences of intrahepatic CCA are rising and prognosis of CCA is dismal with surgical resection or liver transplantation as only curative treatment options. Chronic inflammation of the bile ducts and surrounding portal fields are a hallmark of CCA pathogenesis. Chronic diseases of the intra- and extrahepatic bile ducts, such as primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC) predispose to CCA development. Bile acids (BAs) play a fundamental role in both liver damage and regeneration. BA effects are mediated through different receptor molecules, comprising nuclear BA receptors (BARs) and G protein-coupled receptors (GPCRs), such as the Takeda G protein-coupled receptor-5 (TGR5, GPBAR1) or the sphingosine 1-phosphate receptor-2 (S1PR2). While secondary BAs have been shown to impair epithelial barrier function in different epithelial cells through disruption of tight junction integrity, BARs such as TGR5 can protect epithelial cells at the interface with bile through increased bicarbonate secretion and phosphorylation and stabilization of tight junction and adhesional molecules., TGR5 is expressed in biliary epithelial cells (BECs, cholangiocytes) throughout the biliary tree including the extrahepatic duct as well as the gallbladder both in humans and rodents. TGR5 is localized both in the apical membrane and in the primary cilium which represent the interface of BECs with bile. Previously, we identified an essential role of TGR5 and TGR5-dependent signaling for BA-induced BEC proliferation. Besides proliferation, TGR5 protects BECs from BA toxicity and preserves integrity of the epithelial barrier. The mechanisms contributing to this protective effect comprise anti-apoptotic signaling, strengthening of tight junction integrity and increased chloride and bicarbonate secretion. The latter contributes to the formation of the so-called „bicarbonate umbrella”, which shields the biliary epithelial barrier from the detergent activity of biliary BAs. Absence of TGR5 in mice was associated with a maladaptation to injury resulting in aggravated biliary injury, reduced compensatory biliary proliferation, increased portal pressure, rapid development of liver fibrosis. In line with these findings, we observed a disease and cell-type specific downregulation of TGR5 in BECs from patients with PSC, a rare cholestatic liver disease characterized by chronic inflammation and progressive fibrosis of the intra- and extrahepatic bile ducts. Mice lacking the hepatocyte phospholipid floppase Abcb4 recapitulate the progressive fibrosing cholangitis aspect of human PSC and also develop intrahepatic malignancy. We recently described that reduction of TGR5 in BECs of Abcb4, -/-, mice triggers development of the inflammatory, reactive BEC phenotype typical for sclerosing cholangitis as demonstrated by single-cell RNA-sequencing. In contrast, overexpression of TGR5 abolished the reactive BEC phenotype, which could also be achieved by norUDCA feeding. The latter was associated with normalization of TGR5 expression in BECs of Abcb4, -/-, mice. We thus identified a hitherto unknown mode of action of norUDCA, which is currently tested in a phase III clinical trial for PSC. In addition to TGR5, BECs and immune cells also express S1PR2. While liver injury was aggravated in TGR5, -/-, , knockdown of S1PR2 ameliorated liver damage. The extent to which the functions of these two BARs overlap and in which aspects their role differs in BECs is yet unclear. Moreover, the interplay of TGR5 and S1PR2 in different liver cells during cholestasis is incompletely understood. Both TGR5 and S1PR2 are druggable targets with a variety of potential applications in liver diseases. A better understanding of the regulation, function and interaction of TGR5 and S1PR2 in BECs and adjacent immune and matrix cells under physiological and biliary disease conditions is the central aim of the project. We hypothesize that both TGR5 and S1PR2 contribute to BEC barrier function and that maladaptation of the crosstalk and the mutual interdependence of these BARs in BECs and surrounding immune cells and myofibroblasts in response to injury results in biliary disease.
2024 to 2027
Deutsche Forschungsgemeinschaft (DFG)
Boolean Functions meet Combinatorics
In this project, we suggest a completely novel approach to studiying vectorial functions pn vector spaces over finite fields. The novelty is the fact that we are going to describe the important differential properties of Boolean functions in terms of design theory. This may open a completely new approach to the investigation of differential properties of Boolean functions. We also expect that the well-known ninlinearity measure of functions via the Walsh transform can be extended by replacing the classical Sylvester-Hadamard matrix by a different Hadamard matrix.
2024 to 2027
Deutsche Forschungsgemeinschaft (DFG)
The role of GABAergic interneurons in mouse superior colliculus in visual processing and visually guided behaviours
A central task of the visual system is to detect behaviourally relevant objects in the environment and to guide appropriate behavioural responses. The superior colliculus (SC) in the midbrain receives direct inputs from the retinal ganglion cells and plays key roles in visually guided behaviours. Importantly, the superior colliculus houses a high density and large diversity of inhibitory neurons, suggesting a vital role of inhibitory neurons in visual processing in the superior colliculus. However, how different inhibitory neuron types sculpt the neuronal representation of visual information within the superior colliculus, and their role in visually guided behaviours is poorly understood. The main objective of this Project is to study the role of inhibitory neurons in superior colliculus through large-scale electrophysiological recordings using high-density electrodes, cell-type specific identification and causal optogenetic perturbation of superior colliculus neurons in head-fixed mice that preform a visually guided behavioural task, in combination with advanced data analysis and computational modelling. To understand how inhibitory neurons in the superior colliculus shape the representation of visual information we will (1) investigate how superior colliculus neurons integrate inputs from retinal ganglion cells in vivo using a newly developed method and reveal the role of inhibitory SC neurons in visual processing by optogenetic manipulation (2). To study the role of inhibitory SC neurons in visually guided behaviours, we will (3) record the activity of optogenetically identified neurons during a visual detection task and investigate how visual and behavioural information is represented on the high-dimensional level in neuronal populations using advanced data analysis. Moreover, to test the causal role on the behaviour we will perturb inhibitory neurons using optogenetic manipulations during the task (4). Finally, we will (5) integrate the experimental data in a computational circuit model of the visual layers of the superior colliculus to investigate how interacting excitatory and inhibitory neurons integrate and shape visual processing. Thus, the overarching goal of this Project is to examine how inhibitory neurons in the superior colliculus sculpt the population activity in during the visual processing and to reveal their causal role in visually guided behaviours.
2021 to 2027
Deutsche Forschungsgemeinschaft (DFG)
GRK2408/TP12 - Th2 cell-dependent effects on the airway epithelial barrier during chronic asthma
Allergic asthma is characterized by chronic inflammation and airway remodeling, which involves epithelial barrier dysfunction, fibrosis, goblet cell hyperplasia/metaplasia, smooth muscle thickening and increased endothelial permeability (Lambrecht & Hammad, 2015). Repetitive chronic exposure to allergens such as from HDM mediates a dysregulation of the airway epithelia including alveolar type II cells (AECsII) (Heijink et al., 2020). This cumulates in Th2 cell activation and the amplification of asthmatic airway inflammation. However, how the intercellular communication between alveolar epithelial cells and Th2 cells contributes to the fixation of especially chronic asthmatic airway inflammation is still not fully understood. We hypothesize that in chronic asthma, metabolites provide a specific metabolic environment within the lung, which favors chronic inflammation and fixation of the disease by changing the epithelial barrier.
2021 to 2027
Deutsche Forschungsgemeinschaft (DFG)
Hetero-aggregation of fluidized nanoparticles and solid-containing aerosol droplets
The project aims at mixing in fluidized bed very small particles (nanoparticles or submicron particles) of different composition to hetero-agglomerates, which may additionally be encapsulated or coated with the help of aerosol droplets that contain embedding solid material. In this way, binary or ternary particulate composites of extremely finely dispersed constituents are produced. Instead of conventional fluidization, special spouted bed equipment with adjustable air inlet is used for processing. High-velocity air inlet jets help to shift the dynamic equilibrium between aggregation and breakage towards smaller and stronger agglomerates in this kind of equipment. Regarding the characterization of agglomerates, new methods to reconstruct 3D agglomerate structure from 2D imaging data are developed. In this frame, the level of sub-agglomerate mixing can be identified and pushed towards individual nanoparticles by use of non-flame, i.e. not sintered, raw material. To describe the process, novel population balances and discrete models are used. Hetero-agglomerate conductivity (thermal, electrical) is measured and modelled.
2018 to 2027
Deutsche Forschungsgemeinschaft (DFG)
Maladaptive processes across physiological barriers in chronic diseases
Graduiertenkollge 2408, Chronische Erkrankungen stellen eine zunehmende gesundheitspolitische Herausforderung dar. Zelluläre Maladaptationen und die fehlgeleitete Zell-Zellkommunikation an physiologischen Barrieren sind mechanistische Aspekte von zentraler Bedeutung bei chronischen Erkrankungen wie Atherosklerose oder chronische Erkrankungen der Niere, der Haut, oder des Gastrointestinaltrakts. Physiologische Grenzflächen werden durch hoch spezialisierte Zellen, z.B., Endothelzellen, oder, Epithelzellen, , definiert. Störungen in der Regulation und Funktion dieser Grenzflächen führen zu einem pathophysiologischen Mikromilieu, charakterisiert z.B. durch ein spezifisches Sekretom sowie der Aktivierung lokaler Zellen und/oder Rekrutierung von Entzündungszellen. Von besonderer Bedeutung bei chronischen Erkrankungen ist die, Perpetuierung, maladaptiver Prozesse, die auf, posttranslationalen Proteinmodifikationen, beruhen. Das Verständnis molekularer Veränderungen, die maladaptiven Krankheitsprozessen an physiologischen Grenzflächen zugrunde liegen, ist derzeit noch sehr limitiert. Innerhalb des, GRK’s, beabsichtigen wir Krankheit-auslösende maladaptive Prozesse an, endothelialen und epithelialen Grenzflächen, zu erforschen.
2018 to 2027
Deutsche Forschungsgemeinschaft (DFG)
Maladaptive Prozesse an physiologischen Grenzflächen bei chronischen Erkrankungen. Projekt P2: Einfluss epigenetischer Genregulationsmechanismen auf die Pertubation intestinaler Entzündung und die Entstehung von Dysplasie
Akute Entzündungen sind in der Regel selbstlimitierend und nach ihrem Abklingen wird im zuvor entzündeten Bereich wieder der immunologische Grundzustand hergestellt. Unter bestimmten Bedingungen kann sich aus einer zunächst akuten jedoch eine chronische Entzündung etablieren, die sich dann weiter zur Dysplasie und im ungünstigsten Fall zu einer bösartigen Tumorerkrankung weiter entwickeln kann. In unserem Teilprojekt P2 innerhalb des GRK 2408 möchten wir der Hypothese nachgehen, dass sich entzündliche Veränderungen durch posttranslationale Histonmodifikationen im Genom intestinaler Epithelzellen dauerhaft manifestieren können und dass diese epigenetischen Veränderungen im Darmepithel an der Entstehung chronischer Darmerkrankungen und Darmkrebs mechanistisch beteiligt sind. Unsere Analysen basieren auf dem Einsatz moderner ChIP-Seq und RNA-Seq Analysen an primären intestinalen Epithelzellen aus gesunden Mäusen im Vergleich zu Mäusen mit akuter und chronischer Colitis sowie Mäusen mit Darmkrebs. Perspektivisch planen wir, unsere im Tiermodell gewonnenen Daten anhand von humanen Darmbiopsien zu überprüfen.
2023 to 2027
Deutsche Forschungsgemeinschaft (DFG)
"Multi-stage catalytic production systems for fine chemistry through integrated design of molecules, materials and processes (IMPD4Cat)"
Cooperation project in Research Unit 5538 Multi-stage catalytic production systems for fine chemistry through integrated design of molecules, materials and processes., Subproject SP6, "Integrated computer-aided molecule, material and process design for the multi-stage catalytic conversion of olefins into alpha-amino acids and beta-amino alcohols, This text was translated with DeepL
2024 to 2027
Deutsche Forschungsgemeinschaft (DFG)
Multiregional circuits underlying sensorimotor behaviours
Orienting movements are essential for animals to actively sense and interact with their environment. The superior colliculus is crucial for multimodal sensory integration and orienting motor behaviors; however, it does not operate in isolation but in close interaction with thalamo-cortical circuits. Therefore, appropriate sensorimotor behaviors require a dynamic interaction between the cortex and the superior colliculus, yet the underlying circuit mechanisms remain largely elusive. In this project, we investigate these circuit mechanisms and the role of cortico-collicular interactions in motor preparation, navigation, decision-making, and sensorimotor learning. To that end, we employ a novel real-world floating environment and high-density electrodes to study the neuronal basis of active sensing and voluntary body movements. This project aims to provide new insights into the role of cortico-collicular-thalamic circuits in guiding naturalistic behavior and sensorimotor learning.
2024 to 2027
Deutsche Forschungsgemeinschaft (DFG)
Two-, three- and four-way coupling of suspended elongated particles in turbulent flows
The project deals with the development of precise models to describe the behavior of non-spherical particles in turbulent multiphase flows, which frequently occur in industrial processes., The aim is to overcome the previous assumption of spherical particles, as it often leads to inaccurate results. Using an Euler/Lagrange approach that integrates LES and RANS methods, particle feedback effects on the flow, fluid dynamic interactions and particle collisions are to be taken into account. The models are based on fundamental physical principles and are derived using particle-resolved direct numerical simulations (PR-DNS). The results should significantly improve the prediction and optimization of processes with non-spherical particles., This text was translated with DeepL
2023 to 2027
Deutsche Forschungsgemeinschaft (DFG)
Selbstlernende Regelung der katalytischen Umwandlung von Olefinen zu α-Aminosäuren und β-Aminoalkoholen
Dieses Vorhaben ist Teil der DFG-Forschergruppe FOR5538: Mehrstufige katalytische Produktionssysteme für die Feinchemie durch integriertes Design von Molekülen, Materialien und Prozessen (IMPD4Cat). Im Rahmen des vorliegenden Projektes sollen selbstlernende Regelsysteme für die Online-Optimierung der katalytischen Konversion von Olefinen zu α-Aminosäuren und β-Aminoalkoholen entwickelt werden., Als Prozessbeispiele sollen in der ersten Förderphase die enzymkatalysierte Reaktionen von α-Keto Carboxylsäuren zu α-Aminosäuren, insbesondere Homophenylalanin, und α-Hydroxyketonen zu β-Aminoalkoholen, insbesondere Homophenylalaninol, mit integrierter Produktkristallisation betrachtet werden. Anschließend sollen auch die Membrantrennprozesse zur Katalysator- und Lösungsmittelabtrennung untersucht werden., Dazu wird eine repetitive Online-Optimierung auf 'single batch' und/oder 'batch to batch' Ebene durchgeführt, wobei die Betriebsbedingungen mit Hilfe verfügbarer Messinformation und, sogenannten hybriden mathematischen Modellen zyklisch re-adjustiert werden. Die hybride Modellierung kombiniert dabei das physikalisch chemische Grundlagenwissen aus den anderen Teilprojekten mit datengetriebene Ansätzen des maschinellen Lernens. Wesentliche Arbeitsschritte umfassen: (i) die Entwicklung geeigneter hybrider Modelle für die betrachteten Prozessschritte, (ii) die Entwicklung geeignete Methoden für die Online-Adaption der entwickelten Modelle und (iii) effiziente Strategien für die Online-Optimierung, (iv) die Integration der genannten Methoden im Rahmen eines selbstlernenden Regelungskonzeptes, (v) systematische in silico Tests und (vi) schließlich die experimentelle Validierung in Kooperation mit den anderen Teilprojekten dieser Forschergruppe.
2024 to 2027
Deutsche Forschungsgemeinschaft (DFG)
The immunoproteasome in cancer-associated myositis - a possible link between autoimmunity and cancer
Dermatomyositis (DM) is a systemic autoimmune disease with close association of subgroups to malignancy. As an immune response, diverse autoantibodies as well as characteristic cellular infiltration, overexpression of MHC class-I and an interferon signature are detectable in affected skin, muscle and organ tissues such as lungs. The associated pathogenesis is unclear, whereby only specific autoantibodies such as against TIF1g are available to date for the risk assessment of a malignancy. Preliminary results show an increased expression of immunoproteasome subunits in DM, whereby this was detectable in muscle cells as well as in infiltrating dendritic cells, CD68+ macrophages and CD8+ T cells. Of note, an overexpression of certain, inducible subunits of the immunoproteasome was shown particularly in cancer-associated DM. Since the proteasome system is variously involved in the regulation of cellular homeostasis as well as in immune regulation via the production of antigenic peptides for the MHC class I presentation pathway, and became activated under the influence of inflammatory cytokines such as interferon-g into the immunoproteasome, these results are to be expected. However, the proteasome also plays a relevant role in malignant diseases and proteasome inhibitors represent an effective therapy option, e.g. in multiple myeloma. This raises the question for us whether and how the proteasome is involved in the pathogenesis of cancer-associated DM? The investigations planned for this purpose can clarify whether there are differences in the expression and function of the proteasome in DM patients with malignancy. To investigate the involvement of the proteasome in the pathogenesis of cancer-associated DM in more depth, our aim is to clarify if i) identification of DM patients at risk of cancer is possible by cytometric and/or mRNA profiles, ii) the relevant myositis antigens TIF1-γ and Mi-2 show different expression and modification in skeletal muscle samples as well as in cell lines, iii) the tumor suppressor proteins p53/pRb and the anti-oxidative stress transcription factor Nrf2, which are regulated by proteasome, show an association to cancer development, iv) selected peptides of TIF1-γ and Mi-2 exhibit an effect on the TCR and BCR repertoire, and v) if isolated anti-TIF1-γ and anti-Mi-2 antibodies express effects upon proliferation, apoptosis and cytokine production of primary muscle cell culture and cancer cell lines.
2023 to 2027
Deutsche Forschungsgemeinschaft (DFG)
Basale Vorderhirn vermittelte Modulationen der Informationsverarbeitung in olfaktorischen kortikalen Arealen bei wachen Mäusen
Die sensorische Informationsaufnahme und -verarbeitung gehört zu den zentralen Aufgaben des Gehirns. Sensorische Informationen werden durch mehrere Gehirngebiete geleitet, die diese verarbeiten und massiv modulieren, um sie an die Bedürfnisse des Tieres anzupassen. Solche zustandsabhängigen Anpassungen können durch klassische neuromodulatorische Zentren wie dem basalen Vorderhirn oder dem Locus coeruleus vermittelt werden, die eine Vielzahl von unterschiedlichen Hirnarealen entlang der sensorischen Bahnen innervieren. Das basale Vorderhirn ist dabei ein besonders relevantes Zentrum, da es z.B. durch eine Verstärkung von relevanten Signalen oder der Schärfung von rezeptiven Feldern das Verhalten sowie kognitive Prozesse beeinflussen kann. Neuere Studien deuten darauf hin, dass zustandsabhängige Verhaltensanpassungen wahrscheinlich auf ein komplexes Zusammenspiel von Modulationsvorgängen auf kortikalen sowie subkortikalen Verarbeitungsebenen zurückzuführen sind. Im olfaktorischen System konzentrierte sich die neuromodulatorische Forschung bisher vor allem auf den Riechkolben (olfaktorischer Bulbus), der ersten zentralen Ebene der olfaktorischen Informationsverarbeitung. Modulationen auf der Ebene des olfaktorischen Kortex wurden bisher weitgehend ignoriert, nicht zuletzt aufgrund des Fehlens detaillierter Kenntnisse der anatomischen Verbindungen zwischen dem basalen Vorderhirn und dem olfaktorischen Kortex sowie der eingeschränkten Zugänglichkeit dieser tiefen Hirngebiete.In diesem Projekt planen wir den Einfluss des basalen Vorderhirns auf zwei primäre olfaktorische kortikale Areale, den vorderen olfaktorischen Kern (AON) und den vorderen piriformen Kortex (APC), detailliert zu untersuchen. Diese kortikalen olfaktorischen Areale scheinen von besonderer Bedeutung zu sein, da sie nicht nur direkte sensorische Eingänge sowie zentrifugale Projektionen von neuromodulatorischen Zentren erhalten, sondern auch zahlreiche Rückprojektionen zum OB senden. Zunächst werden wir die zentrifugalen Verbindungen des basalen Vorderhirns zum AON bzw. APC mithilfe eines dualen neuronalen Tracings im Hinblick auf folgende Fragestellungen untersuchen: Welche neuronalen Subtypen und Unterkerne des basalen Vorderhirns projizieren zu den jeweiligen olfaktorischen Kortex-Gebieten und gehören Neurone des basalen Vorderhirns, die zu AON und APC projizieren, zu separaten oder zu überlappenden Populationen? Zudem planen wir mit diesem Tracing-Ansatz, AON- oder APC-projizierende Neurone des basalen Vorderhirns selektiv mithilfe neuester optogenetischer Konstrukte spezifisch zu modulieren, und gleichzeitig neuronale Aktivität im olfaktorischen Kortex im anästhesierten sowie im wachen, sich verhaltenden Tier aufzuzeichnen. Eine weitere Reihe von Experimenten zielt schließlich darauf ab, die Auswirkungen einer spezifischen Aktivierung oder Hemmung von Fasern des basalen Vorderhirns in AON oder APC auf das olfaktorische Verhalten zu untersuchen.
2023 to 2027
Deutsche Forschungsgemeinschaft (DFG)
Optimierung und Bereitstellung eines präzisen Geruchsapplikationsgerätes...
Die zuverlässige Präsentation von Gerüchen ist eine grosse Herausforderung für die olfaktorische neurowissenschaftliche Forschung. Oft ist die Reproduzierbarkeit von Düften zwischen unterschiedlichen Arbeitsgruppen, oder sogar innerhalb eines Labors, nicht gewährleistet. Eine präzise Stimuluskontrolle ist jedoch für die im Rahmen dieser Forschergruppe zu untersuchenden rekurrenten Eingänge unerlässlich, da nur so deren Modulationseffekte von primären sensorischen Signalen getrennt werden können. In Rahmen dieses Z-Projekts planen wir ein standardisiertes Geruchsapplikationsgerät (Olfaktometer) zu entwickeln, das sowohl in Nagetier- als auch in Insekten-Laboratorien der Forschungsgruppe eingesetzt werden kann. Der Aufbau des Gerätes wird auf einem vor kurzem von uns veröffentlichten Design eines zeitlich präzisen und modularen Olfaktometers basieren (Ackels et al. 2021). In diesem Projekt planen wir, die spezifischen Bedürfnisse aller teilnehmenden Labore im Hinblick auf ihre vorhandenen Versuchsaufbauten zu erfassen, um anschließend Olfaktometer-Hardware verbunden mit einer professionellen, standardisierten und versionskontrollierten Steuerungssoftware zu entwickeln. In der zweiten Hälfte des Förderzeitraums planen wir, allen teilnehmenden Laboratorien eine erste Generation dieses Olfaktometers zur Verfügung zu stellen. Durch die sorgfältige Entwicklung von Standardarbeitsanweisungen (SOPs) in Kooperation mit zwei ausgewählten Pilotlabors (welche über experimentelle Methoden verfügen, die eine hohe zeitliche Auflösung bieten; Nager: Rothermel, Insekt: Strube-Bloss) werden wir in einem interaktiven Prozess ein Höchstmaß an Verlässlichkeit und Nutzbarkeit des Olfaktometers innerhalb der gesamten Forschungsgruppe sicherstellen. Durch 2-4 wöchige Laborrotationen einzelner Studierender in den Z-Projektlaboren werden wir nicht nur eine kontinuierliche Soft- und Hardware-Unterstützung für das Olfaktometer sicherstellen, sondern das Z-Projekt wird auch als Ankerpunkt innerhalb der Forschungsgruppe fungieren und so ein schnelles und produktives Feedback für zukünftige Entwicklungen sicherstellen. Darüber hinaus werden wir nach der Entwicklung und erfolgreichen Einführung dieses modularen Olfaktometers das Design und die SOPs frei verfügbar machen und so die internationale Sichtbarkeit der Forschungsgruppe weiter erhöhen.
2024 to 2027
Deutsche Forschungsgemeinschaft (DFG)
HELICAP (Health Literacy in Early Childhood Allergy Prevention) -Gesundheitskompetenz-orientierte Beratung zur frühkindlichen Allergieprävention durch Hebammen: partizipative Entwicklung einer Intervention (Gesundheitsprofessionelle)
Der Zeitraum um die Geburt eines Kindes bietet die Möglichkeit zur Verbesserung der elterlichen Gesundheitskompetenz (GK) durch Hebammen. Sie stehen im engen, kontinuierlichen Austausch mit Familien und bieten ihre einzigartige vor- und nachgeburtliche Betreuung und Beratung auch im häuslichen Umfeld an. Dabei tragen sie bereits zur Gesundheitsförderung bei. Allerdings weisen die Ergebnisse unserer qualitativen Studie darauf hin, dass ihr Wissen oftmals nicht ausreicht, um tragfähige Beratungsstrategien zur GK und frühkindlichen Allergieprävention (FKAP) anwenden zu können. Denn: Vorhandene Interventionen zur GK-orientierten Beratung zwischen Gesundheitsfachkräften und Patienten richten sich bisher nicht an (werdende) Hebammen. Mit der Umstellung der Hebammenausbildung auf die Vollakademisierung 2019 wurde nun auch die Gesundheitsförderung durch Hebammen als Tätigkeit gesetzlich verankert. Daher ist es erforderlich, die derzeitigen Praktiken, Barrieren und Förderfaktoren einer GK-orientierten FKAP-Beratung durch Hebammen weiter zu erforschen und eine passgenaue Intervention für die Qualifikation, Fort- und Weiterbildung von Hebammen zu entwickeln. Ziel ist es eine Intervention partizipativ zu entwickeln, die Hebammen unterstützt die GK von Familien in der Beratung zu FKAP einzuschätzen und zu berücksichtigen, GK-orientierte Beratungsstrategien anzuwenden und die GK von Familien allgemein zu fördern. Das Projekt gliedert sich in vier Arbeitspakete und folgt dem MRC Framework. Zunächst wird eine quantitative Datenerhebung und -analyse auf Basis der qualitativen Erkenntnisse zu aktuellen Praktiken, Hindernissen und Förderfaktoren einer GK-orientierten FKAP-Beratung durch Hebammen mittels Befragung von Hebammen aus Rheinland-Pfalz und Bayern durchgeführt. Im zweiten Arbeitspaket werden Co-Design Workshops mit verschiedenen Stakeholdern veranstaltet. Unter Anwendung der design thinking Methode sollen Ideen für eine Intervention generiert werden. Basierend auf diesen Ideen wird im dritten Arbeitspaket eine Intervention entwickelt, die anschließend in Arbeitspaket 4 bei verschiedenen Zielgruppen pilotiert und evaluiert wird. Aufgrund der Förderung der elterlichen GK und FKAP durch Hebammen ist das Teilprojekt (TP) Gesundheitsprofessionelle im Versorgungskontext angesiedelt. TP-Interessenkonflikte und TP-Lebende systematische Übersichtsarbeiten liefern Forschungsevidenz, die auch für TP-Gesundheitsprofessionelle relevant ist. TP-Planetare Gesundheit wird die Entwicklung der Intervention hinsichtlich Erfordernisse aufgrund der Klimafolgen unterstützen. TP-"Doing Health" sowie TP-Epidemiologie geben Einblicke in die FKAP-Praktiken von Eltern. Die Ergebnisse aus TP-Gesundheitsprofessionelle werden mit TP-Nutzerbedürfnisse verglichen.
2024 to 2027
Deutsche Forschungsgemeinschaft (DFG)
Large-scale research device "Real-time deformation cytometer"
A real-time deformability cytometer for the high-throughput characterization of soft microscopic objects in polymer research - in particular microgels, but also vesicles and surfactant-stabilized microdroplets - will be installed at the Chair of Organic Chemistry. The requested device consists of four integrated modules: the actual real-time deformability cytometer (RT-DC), an inverted fluorescence microscope ("F") for multi-channel fluorescence measurements, a sorting unit for the separation of object-laden fluid streams ("so") and a temperature-controlled measuring chamber for the characterization of temperature-sensitive or -responsive materials., The key innovative feature of the soRT-FDC is the use of hydrodynamic forces in microchannels to record not only optical properties - as in conventional flow cytometry - but also mechanical object properties. Originally developed as a cell analysis device, a dedicated application of the proposed device in materials science is planned. Here, the real-time analysis of a large number of optical (brightness, fluorescent dye distribution), morphological (object area/height/length ratio, surface roughness, inertia ratio) and mechanical material properties (deformability or modulus of elasticity) of 100 to 1,000 objects per second will represent a significant further development of the characterization of individual objects, which to date has been based in particular on (confocal) fluorescence microscopy and atomic force microscopy (AFM)., This text was translated with DeepL
2019 to 2027
Deutsche Forschungsgemeinschaft (DFG)
DFG-Forschungsgruppe HELICAP: FOR 2959
Die Stärkung der Gesundheitskompetenz (GK) ist ein prioritäres Public Health (PH)-Handlungsfeld in Deutschland. Es zeigt sich, dass höhere GK mit besserer Gesundheit in Zusammenhang steht und dass über die Hälfte der deutschen Bevölkerung Schwierigkeiten im Umgang mit Gesundheitsinformationen und der Navigation im Gesundheitssystem hat., Aktuell wird GK zumeist verstanden als das Wissen, die Kompetenz und die Motivation von Individuen, Gesundheitsinformationen zu finden, zu verstehen, (kritisch) zu bewerten und anzuwenden, um gute gesundheitsbezogene Entscheidungen treffen zu können., Dieses Verständnis von GK bringt mehrere Herausforderungen mit sich: So ist es notwendig, (i) die individuellen Bedürfnisse und Limitationen nicht nur der Allgemeinbevölkerung, sondern auch spezifischer Zielgruppen, wie z.B. Risikogruppen, zu berücksichtigen, (ii) die komplexen sozialen, ethischen, ökologischen und systemischen Kräfte zu berücksichtigen, die sich auf Gesundheitsentscheidungen auswirken, (iii) die Rolle von sich ändernden wissenschaftlichen Erkenntnissen und professioneller Expertise in der Public-Health Forschung weiter zu klären, sowie, (iv) die Messung von GK voranzubringen und, (v) die Unsicherheit wissenschaftlicher Erkenntnisse und Empfehlungen zu adressieren., Die DFG-Forschungsgruppe HELICAP widmet sich diesen Herausforderungen am Beispiel zweier Anwendungsbereiche, der frühkindlichen Allergieprävention (FKAP) und COVID-19 bei Kindern mit Allergien (COVICAL). Beide sind durch ein hohes Maß an Unsicherheit gekennzeichnet. Auf Grundlage eines modifizierten GK-Modells, in welchem soziale, umwelt- und situationsbedingte sowie persönliche Determinanten einbezogen werden, untersucht HELICAP die GK in fünf verschiedenen Teilprojekten (TP), die vom wissenschaftlichen Koordinierungszentrum (SCC) koordiniert werden. Das SCC ist verantwortlich für das gemeinsames Arbeitsprogramm der HELICAP-Gruppe und setzt dieses in drei Hauptaufgaben um:, (1) Unterstützung der Beteiligung verschiedener Stakeholder durch einen Public Health Partizipationsbeirat, einen wissenschaftlichen Public Health Beirat, sowie die Fortführung der bereits etablierten Task Force „Partizipatives Forschen“ (TFPF), (2) Durchführung einer Begleitforschungsstudie der Beiratstreffen (Konversationsanalyse, teilnehmende Beobachtung) und Evaluation der HELICAP-Workshops sowie, (3) Synthese von Forschungsergebnissen, einschließlich einer Übersicht über in der Forschungsgruppe entwickelte GK-Interventionen auf Bildungs- wie auch auf Systemebene. HELICAP besitzt im Vergleich zur ersten Förderphase einen stärker interventionellen Charakter., Die fünf interdisziplinären Teilprojekte sind:, Interventionen zur Prävention von Allergien bei Kindern und zur Förderung der Gesundheitskompetenz im Zusammenhang mit Allergieprävention und COVID-19: Lebende systematische Übersichtsarbeiten (TP LSR), Gesundheitskompetenz-orientierte Beratung zur frühkindlichen Allergieprävention durch Hebammen: partizipative Entwicklung einer Intervention (TP HP), "Doing health" - eine ethnographische Studie zu (Für-) Sorge Praktiken während der Schwangerschaft und dem ersten Lebensjahr eines Kindes (TP DH), Einrichtungen im Gesundheits- und Sozialwesen als Anbieter von Gesundheitsinformationen zur frühkindlichen Allergieprävention für Eltern: qualitative Implementierungsstudie. (TP UN), Elterliche Gesundheitskompetenz und Prävention, Diagnostik und Behandlung von allergischen Erkankungen bei Kindern (TP EPI), Ziel ist es außerdem, das bereits in der ersten Förderphase modifizierte GK-Modell für die beiden Anwendungsfälle FKAP und COVICAL zu spezifizieren. HELICAP-Workshops, Beiratstreffen, wissenschaftliche Nachwuchsworkshops und die TFPF -Treffen stellen sicher, dass kontinuierlich Raum für interdisziplinären wissenschaftlichen Diskurs besteht.
2019 to 2027
Deutsche Forschungsgemeinschaft (DFG)
DFG-Forschungsgruppe HELICAP: FOR 2959 (WP2)
Nicht reproduzierbare und widersprüchliche Ergebnisse der Gesundheitsforschung können zu Verunsicherung bei Gesundheitsprofessionellen und der Öffentlichkeit führen. Die Methodik der Evidenzsynthese mittels systematischer Übersichtsarbeiten (engl. systematic reviews, SR) wirkt diesem Problem entgegen. SRs (und Leitlinien) verlieren in Feldern dynamischer Forschungstätigkeit wie der frühkindlichen Allergieprävention (FKAP) und Interventionen zur Verbesserung der Gesundheitskompetenz (GK) schnell an Aktualität. Lebende systematische Übersichtsarbeiten (engl. living systematic reviews, LSRs) können die Lücke zwischen aktuellem Wissenstand und praktischer Umsetzung schließen, indem SRs zu Interventionsstudien kontinuierlich aktualisiert werden. Etablierte Methoden der Evidenzsynthese bieten jedoch nur begrenzte Analysemöglichkeiten. Die Meta-Analyse individueller Teilnehmendendaten entwickelte sich als Goldstandard, um Fragestellungen jenseits durchschnittlicher kausaler Effekte wie z.B. zu Heterogenität oder Publikationsverzerrungen zu bearbeiten. Die Translation von Erkenntnissen in die Praxis bleibt jedoch eine große Herausforderung, die bei GPs und Eltern häufig durch Zugangsbarrieren und Verständnisprobleme erschwert wird. Daher ist ein Evidenz-Ökosystem erforderlich, das kontinuierlich Ergebnisse integriert und eine nachhaltige sowie benutzerfreundliche Datenbank bereitstellt. TP2 wendet das Paradigma der Evidenzsynthese auf FKAP und GK an. Konkrete Ziele sind (1) die Aktualisierung von SRs (anknüpfend an die erste Förderphase) sowie Erweiterung des Evidenz-Ökosystems mit Unterstützung der Epistemonikos-Stiftung, (2) die Durchführung von Meta-Analysen individueller Teilnehmendendaten für orale Interventionen wie z. B. Beikosteinführung und hydrolysierte Säuglingsnahrung. Zudem werden (3) das LSR zu Interventionen zur Verbesserung der COVID-19-bezogenen GK fortgesetzt, (4) ein LSR zu FKAP-bezogenen GK etabliert und (5) Zusammenfassungen der Ergebnisse in einfacher Sprache (engl. plain language summaries, PLS) mittels eines partizipativen Forschungsansatzes erstellt. Ein besonderer Fokus wird auf die Aufdeckung von Publikationsverzerrungen gelegt werden, vor allem in Feldern mit starkem Industrieeinfluss. In Jahr 1 werden Datenaustauschvereinbarungen für die Meta-Analysen getroffen, im 2. und 3.Jahr erfolgen die Analysen. Parallel dazu werden PLS zu allen LSR-Themen entwickelt und auf einer interaktiven Website bereitgestellt. TP2 wird ein lebendiges Evidenz-Ökosystem zu FKAP, FKAP-GK und COVID-19-GK erstellen. Es ist eng mit TP1-Interessenskonflikte verknüpft, innerhalb dessen die Evidenzen zu FKAP-Interventionen mit den in der ersten Förderphase identifizierten Leitlinien abgeglichen werden. Zudem ist TP2 mit TP3-Gesundheitsprofessionelle, TP5-Nutzerbedürfnisse und TP7-Planetare Gesundheit verbunden, die edukative und systembezogene Interventionen zur Verbesserung des FKAP-Wissens und der GK entwickeln und pilotimplementieren.
2024 to 2027
Deutsche Forschungsgemeinschaft (DFG)
New alloy families made from recycled aluminum for sustainability and conservation of resources
The need to deal with recycled, secondary materials is constantly increasing. In terms of circular economy, sustainability and resource conservation, the use of recycled, secondary aluminum alloys or closed-loop aluminum alloys offers comparatively particularly large potential. The production of primary aluminum accounts for 3% of total greenhouse gas emissions (15% of emissions in the industrial sector). It requires 1% of global energy production. The energy consumption for processing circular Al alloys is only 5% compared to primary aluminum. The effect of using closed-loop Al alloys to reduce emissions is enormous. It is estimated that the amount of recycled Al will exceed the primary aluminum production in a few years. In the recycling process, impurity and accompanying elements such as Fe, Cu, Ti, V, Cr, Mn, Co, Ni and Zn accumulate beyond the tolerance limits. Due to the formation of intermetallic phases, these elements have a predominantly negative effect on the properties in the entire range of applications of aluminum. The causal removal of the impurity and accompanying elements is associated with an unacceptable high energy consumption or loss of material, or only a partial reduction is achievable. Currently, high-energy pure primary aluminum is added for dilution in order to comply with compositional tolerances of the alloys. However, it is expected that there will be limits for the use of primary aluminum in new products in the future. Research into how to deal with the impurities and accompanying elements that are unavoidably introduced during recycling while maintaining the quality for the use of closed-loop aluminum alloys is of exceptional interest for the environment and the economy. The proposed project has the visionary goal of laying fundamental scientific findings in order to create new families of closed-loop aluminum alloys whose outstanding properties are comparable to or better than those of classic alloys and make economic sense, as well as meeting the sustainability requirement and not degrading in further circulatory cycles. It should thus be possible to integrate every recycled Al component as a closed-loop Al alloy. Here, the intermetallic phases are specifically adjusted by new refiners so that their presence in the microstructure can be tolerated or even be used without any disadvantages. Research into the production and effect of new tailor-made active-reactive refiners and additional surface-active elements using extracted and processed alloy-specific intermetallic particles with the impurity and accompanying elements themselves on the formation of the intermetallic phases provides the key for the appropriate use of those unavoidable impurity - and accompanying elements.
2024 to 2027
Deutsche Forschungsgemeinschaft (DFG)
Molecular catalyst data driven reaction monitoring and control in homogeneous catalysis
Catalysis is one of the most important technologies of our age, that will enhance sustainability in the chemical industry. Catalyst research rather focusses on activity and selectivity then stability of the catalyst. The latter is essential for industrial realization, determines the connectivity of research projects and is essential when switching to renewable feeds. Especially in homogeneous catalysis, there is a small share of stability studies compared to heterogeneous catalysis., The main objective of this project is to provide a deeper understanding of deactivation mechanisms in homogeneous catalysis and how to avoid accompanying negative effects on catalyzed reactions for continuous reaction processes. The introduced 4 deactivation modes will be covered in detail during this project:, Mode 1: Long-term deactivation due to inherent dynamic catalyst complex reactions (ageing), Mode 2: Catalyst losses due to leaching of continuous process incl. catalyst separation/recycle, Mode 3: Deactivation induced by gas/liquid mass transport limitations, Mode 4: Impurity-induced deactivation (inherent dynamic reactor operation), Methodically, this will be achieved by using multi-spectroscopic measurements combined with advanced chemometric analysis during kinetic and continuous experiments including catalyst separation and recycle on process level. The resulting time-resolved molecular data of catalyst species and reactants will be used to develop new mechanistic kinetic models of deactivation. These models serve as origin for model-based process control and optimization, by catalyst dosing strategies, as a countermeasure for negative effects on catalyzed reactions that will be validated in long-term continuous reaction campaigns in miniplants. A fundamental understanding and mathematical description of catalyst deactivation is the basis of a future feedstock substitution in the chemical industry.
2024 to 2027
Deutsche Forschungsgemeinschaft (DFG)
Active particle assemblies and active elastic solids under hydrodynamic, viscoelastic and elastic interactions in thin, enclosing layers
Project description according to DFG, see GEPRIS (, https://gepris.dfg.de/gepris/projekt/541972050, ):, "It is fascinating to observe the emergence of collective motion in assemblies of self-propelled particles. At the same time, such investigations are of great importance for understanding the fundamental properties of active matter in general. Individual propelled objects in such assemblies can align their directions of motion through direct mutual adjustment. However, a surrounding medium can also promote the emergence of collective motion. The latter has been investigated in particular for active microswimmers in space-filling viscous fluids at small Reynolds numbers. In this project, we extend corresponding studies of fundamental properties of active matter in three fundamental directions. First, we include the role of surrounding media. We consider thin films on substrates or free-standing films, which allows a two-dimensional evaluation. They enclose the active objects in the layer or film plane. The presence of the surrounding medium leads to additional interactions between the active objects. Secondly, we concentrate on the influence of the viscoelasticity of the surrounding medium. This means that in addition to the effects of flow, elasticity must also be taken into account. This often applies to biological systems. However, model experiments using synthetic particles have also been carried out to investigate the influence of viscoelasticity. Perfectly elastic media form a limiting case. Finally, we investigate the dynamics of active solids. For this purpose, elastic spring networks are considered as models of elastic solids but also assemblies of self-propelled objects under mutual isotropic attraction. As a result, we investigate the collective and internal dynamics of assemblies of active objects and of active solids under spatial constraints and in viscoelastic environments. The contributions of the respective components are quantified. By bringing these contributions together, we support the transfer of central, fundamental concepts from research on theoretical and artificial model systems to studies on biological systems. We choose the different topics in such a way that collaborations and joint progress together with leading experimental research groups in the respective fields are possible. As a future extension of our investigations, we are considering studies on motion-induced phase separation and the derivation of corresponding statistical field theories.", (DFG procedure for grants in kind), This text was translated with DeepL
2024 to 2027
Deutsche Forschungsgemeinschaft (DFG)
Integration of physically motivated material models for filled elastomers in multi-body simulations of highly dynamic systems
The DFG-funded research project aims to increase the numerical prediction capability for technical systems by implementing a holistic simulation methodology that enables efficient coupling between a multi-body simulation and a non-linear FE model. An extension of the physically motivated dynamic flocculation model is used to fully and precisely map the non-linear material behavior of elastomeric bearing elements. The focus here is primarily on the changes in the properties of the bearings under multi-axial loading, which are often neglected in current modeling approaches at . Since the integration of a detailed FE model leads to an increase in the necessary computing resources, different levels of detail of the solver coupling are implemented and analyzed in this project with the aim of allowing a reduction in computing time with an acceptable loss of accuracy. The resulting different levels of complexity of the developed methodology are comprehensively compared with conventional modeling strategies. The individual coupling strategies are evaluated with regard to the implementation and parameterization effort as well as the physical interpretability and the required computing resources. The developed and validated FE models based on the DFM are also examined with regard to their suitability, to what extent and with what reliability certain material parameters can be transferred once to other geometries and load scenarios. Finally, the accuracy of all investigated strategies for coupling the FEM and MBS is assessed with the aid of test results from real applications. The FEM is integrated into the MBS both directly via various solver couplings and indirectly by generating a characteristic map or a surrogate model with the aid of the FE model for use within the MBS. The first application example is a laboratory centrifuge, whose vibration amplitudes and operating resonances are measured and compared with the numerically obtained results of the respective coupling strategies. Furthermore, the developed methodology is applied and validated in the context of a vibration analysis of chassis components of an electric vehicle., This text was translated with DeepL
2024 to 2027
Deutsche Forschungsgemeinschaft (DFG)
Efficient nonparametric analysis of diagnostic and prognostic bio- markers
Diagnostic trials to evaluate biomarker reliabilities have become an important area in clinical as well as in pre-clinical and translational research. Existing statistical methods mostly rely on total areas under ROC curves and thus take the entire range of true and false positives into account. Partial areas under the ROC curves (and other accurate measures, e.g. Youden-indices) are more informative, because they focus on clinically relevant segments. Statistical inference methods for the analysis of these measures in factorial diagnostic trials have not been developed and implemented yet. This project aims to close these gaps to improve biometric practice. The proposed research has been motivated by, various real trials and statistical consulting.
2018 to 2027
Deutsche Forschungsgemeinschaft (DFG)
Relevance of mast cells in maladaptation of the epidermal and endothelial, barrier during chronic skin inflammation
Chronische Erkrankungen stellen eine zunehmende gesundheitspolitische Herausforderung dar. Zelluläre Maladaptationen und die fehlgeleitete Zell-Zellkommunikation an physiologischen Barrieren sind mechanistische Aspekte von zentraler Bedeutung bei chronischen Erkrankungen wie Atherosklerose oder chronische Erkrankungen der Niere, der Haut, oder des Gastrointestinaltrakts.Physiologische Grenzflächen werden durch hoch spezialisierte Zellen, z. B. Endothelzellen oder Epithelzellen, definiert. Störungen in der Regulation und Funktion dieser Grenzflächen führen zu einem pathophysiologischen Mikromilieu, charakterisiert z. B. durch ein spezifisches Sekretom sowie der Aktivierung lokaler Zellen und/oder Rekrutierung von Entzündungszellen. Von besonderer Bedeutung bei chronischen Erkrankungen ist die Perpetuierung maladaptiver Prozesse, die auf posttranslationalen Proteinmodifikationen beruhen. Das Verständnis molekularer Veränderungen, die maladaptiven Krankheitsprozessen an physiologischen Grenzflächen zugrunde liegen, ist derzeit noch sehr limitiert. Innerhalb des GRK’s beabsichtigen wir Krankheit-auslösende maladaptive Prozesse an endothelialen und epithelialen Grenzflächen zu erforschen. Mittels systematischer Ansätze planen wir Untersuchungen zur Bedeutung posttranslationaler Modifikationen für die Barrierefunktion (z. B. Zellmigration), die Proteostase (z. B. Bedeutung des endoplasmatischen Retikulums, des Proteintransports und Abbaus), sowie molekularer Netzwerke (z. B. HIF oder NF- B Signaltransduktion, Zytokine) an endothelialen und epithelialen Grenzflächen. Die vergleichenden Untersuchungen dieser beiden Grenzflächen-definierenden Zelltypen ermöglicht den Studenten einen Ideenaustausch sowie die gemeinsame Nutzung experimenteller (z. B. Tiermodelle, Ko-Kultur Systeme) und technologischer (z. B. hochauflösendes 3D-imaging, Intravital 2-photon-Mikroskopie, Massenspektrometrie) Systeme, von Reagenzien und methodischen Ansätzen, was einen erheblichen Mehrwert in der Ausbildung der Studenten darstellt. Zudem unterstützt die unmittelbare Interaktion mit Medizinstudenten und Klinikern eine translationale Ausrichtung der Projekte. Somit wird das GRK junge Wissenschaftler in einem hoch-relevanten Thema unter Verwendung von state-of-the-art Techniken ausbilden und ihnen eine breit angelegte Basis für eine wissenschaftliche Karriere bieten.
2021 to 2027
Deutsche Forschungsgemeinschaft (DFG)
Urban Mobility and Logistics: Learning and Optimization under Uncertainty
The goal of this project is to systematically improve quantitative decision support for urban mobility and logistics, to analyze its methodological functionality, to derive general conceptual insight, and to use the derived concept for future method designs.For applications in urban mobility and logistics, operational decision support needs to be effective, fast, and applicable on a large scale - often under incomplete information. Providers face uncertainty in many components, for example, the customer demand, the urban traffic conditions, or even the driver behavior. Mere adaptions to new information are often insufficient and anticipation of this uncertainty is key for successful operations. In research and practice, a range of anticipatory methods has been developed, usually tailored to specific practical problems. Such methods may follow intuitive rule-of-thumbs, draw on sampling procedures, or use reinforcement learning techniques. While the methods may perform well for individual problems, there is still a very limited understanding of the general dependencies of a method’s performance and a problem’s characteristics. This research project will provide this conceptual understanding.To this end, the project will systematically develop and compare different methodology for a set of problems from three different application areas, one combining urban mobility and transport as a service, one using a network of parcel stations for urban transportation, and one performing pickup and delivery with a gig economy workforce. The three problems differ in several dimensions, especially in their sources of uncertainty. To classify the problems, measures will be developed, for example, with respect to the scale of the problem or structure and degree of uncertainty. For each problem, a set of different methods will be developed. The methods will improve decision support for the specific problems while simultaneously allowing a systematic analysis of dependencies between problem and methodology performance. To this end, additional measures will be developed to classify method performance, for example, decision speed, or the interpretability of a method. Based on the problem and method measures and the extensive experiments and analyses, a framework will be developed to guide future method design for this emerging research field.This project will span six years and will be hosted at the TU München (TUM). During the project, the PI will supervise three PhD-students, each student working four years in one application area. The PI and the students will collaborate with researchers from TUM and the Georgia Institute of Technology.
2024 to 2027
Deutsche Forschungsgemeinschaft (DFG) // Land Sachsen-Anhalt
DFG large-scale research unit: Processing station for electrochemical precision ablation
Due to the wide range of applications of EC ablation in automotive, aerospace, medical technology and tool and mold making, the processing station for EC precision ablation includes the necessary equipment with additional components that enable research into fundamental issues through to applied research along the product value chain. EC precision ablation is based on the ablation of metallic materials using pulsed direct current and an oscillating cathode. Due in particular to the process-related advantages, such as damage-free surfaces, high surface quality and burr-free machining, EC precision ablation is the focus for highly stressed components and precision components whose surfaces must not be affected by the manufacturing process. In addition to researching the basic material-specific removal mechanism of EC precision machining, research at the Chair of Production Engineering with a focus on cutting will focus on resource-efficient EC technologies, process control of EC precision machining through simulation as well as interfaces and data chains for digital twins of EC precision machining processes., This device is funded by the German Research Foundation (DFG) with project number 467011871., This text was translated with DeepL
2024 to 2027
Deutsche Forschungsgemeinschaft (DFG) // Land Sachsen-Anhalt
DFG large-scale research unit: Machining station for precision spark erosion
Precision spark erosion is a machining process in precision and micro-manufacturing technology that is used to produce tools and machine elements with the highest precision requirements. Due in particular to the process-related advantages, such as machining independent of the mechanical workpiece properties and freedom from burrs, precision spark erosion is the focus for highly stressed components and products made of high-strength materials. Using the device applied for, the process variants of precision spark erosion sinking, precision spark erosion drilling and precision spark erosion milling can be researched. In addition to micro-manufacturing issues in the near-surface area, research work in the macroscopic component area focusing on precise shaping, resource-efficient production and functional surfaces can also be realized. The device applied for addresses components with processing areas of up to around 600 cm², which can be processed using a required pulse current of up to 80 A. In addition to researching the fundamental process understanding of precision spark erosion, the Chair of Production Engineering with a focus on cutting will also focus on resource-efficient technologies, process control of precision spark erosion through simulation as well as interfaces and data chains for digital twins of precision spark erosion., This device is funded by the German Research Foundation (DFG) with project number 509924008., This text was translated with DeepL
2024 to 2027
Deutsche Forschungsgemeinschaft (DFG)
The role of SLAMF7 during differentiation of CD4 T helper cells
Oberflächenmoleküle, die auf THelfer-Zellen exprimiert werden, steuern deren Schicksal und bieten eine wirksame Strategie zur Steuerung von Immunantworten. Um neue Signalkomponenten zu bestimmen, die bei der Aktivierung von THelfer-Zellen induziert werden, haben quantitative Phosphoproteomics und Massenspektrometrie ergeben, dass SLAMF7 eine Komponente bei T-Zell-Antworten ist. Erste Daten aus der Literatur sind widersprüchlich, so kann SLAMF7 in NK Zellen sowohl aktivierende als auch inhibierende Funktion ausführen und in CD4 THelfer Zellen wurden sie mit zytotoxischen Molekülen detektiert. Über CD4 T-Zellantworten in vitro haben wir erste Hinweise, dass SLAMF7 unterschiedlich häufig auf Subpopulationen exprimiert wird, was zum Teil auf TGFβ zurückgeführt werden kann. In dem vorliegenden Projekt soll nun die Rolle von SLAMF7 für THelfer Zellen in einem Infektionsmodell untersucht werden.
2024 to 2027
Deutsche Forschungsgemeinschaft (DFG)
Molecular and cellular characterization of cell death pathways involved in Leishmania host cell exit and cell-to-cell transfer
In order to survive and replicate as a parasite population, L. major, amastigotes have to undergo cycles of infection, intracellular proliferation, host cell exit and entry into new host cells. By the combination of both, in vitro, human live cell imaging, flow cytometry quantification of the exit process and intravital 2-photon imaging of the infection site in the mouse model, we aim to identify mechanisms underlying this fundamental process crucial for, Leishmania, persistence, propagation and pathogenesis., Using a genetically encoded proliferation reporter system and growth-inhibited KBMA pathogens, we found in the first funding period of the SPP that, Leishmania, exit, both, in vivo, and, in vitro, is triggered by the parasite’s proliferation state. Highly proliferating amastigotes are the predominating form involved in exit and pro-inflammatory macrophages were found as the preferred niche for strongly increased proliferation. Involvement of apoptosis in human macrophages, in vitro, and in the mouse tissue, in vivo, was demonstrated, whereby exit was mostly observed in the context of cell material transfer from the initially infected cell. This suggests a direct cell-to-cell transfer with only minimal exposure to the extracellular milieu. Also, pyroptosis, in addition to apoptosis, might contribute to the process. Furthermore, we found evidence that, Leishmania, proliferation modulates the host cell metabolism such as expression of the lipid receptor CD36, which might impact both on host cell death, as well as on efferocytosis by other cells., We now aim to elucidate the involvement of both apoptosis and pyroptosis in pathogen exit on a molecular level by using the BLaER1 cell line and cell death-specific caspase-3 and Gasdermin D knockouts. These experiments will be complemented using caspase-3 inhibition and Gasdermin D deficient host cells in the mouse model., Using both the proliferation reporter and KBMA systems, we want to dissect the host cell phenotypes supporting efficient exit of amastigotes, which will enable FACS sorting enrichment and consequent mass spectrometry analyses as well as functional and correlative imaging of the exit mechanism in more detail. Finally, to investigate the metabolic changes required for a productive cell-to-cell transfer, we will characterize host cell lipid metabolism and address the impact of CD36 deficiency both for pathogen exit as well as for pathogen uptake by new host cells.
2023 to 2027
Deutsche Forschungsgemeinschaft (DFG)
Scaling Invariant Multidimensional Projections for Information Visualization
Finding good projections from multi-dimensional data domains to the 2D screen is a standard problem in many fields. Multidimensional data usually considered in Multifield Visualization (a subfield of Scientific Visualization) often comes with the property that the dimensions are measured in different physical units, making the ratio between arbitrary. We propose to develop projection techniques thatare independent of the chosen physical unit of each dimension, i.e., they are invariant on the scaling of each dimension. While many standard measures and features do not have this scaling invariance (such as relative Euclidean distance, PCA, t-SNE), simple solutions like normalization of each dimension does not solve the problem adequately. We propose to develop scaling invariant versions of standard automatic non-linear projection techniques such as t-SNE or UMAP. Also, we search for scaling invariant versions of linear projections (such as PCA), as well as for standard clustering techniques. We see the main application of scaling invariant projection techniques in the visual analysis of multifield data.
2024 to 2026
Deutsche Forschungsgemeinschaft (DFG)
AddBluff4NH3/H2: Additive manufactured bluff-body burner, characterized by detailed simulations and experiments for fuel-flexible, stable and safe combustion of NH3/H2 mixtures
This project is a joint project within the framework of the, DFG SPP 2419 "A contribution to the realization of the energy transition: Optimization of thermochemical energy conversion processes for the flexible use of hydrogen-based renewable fuels through additive manufacturing processes"., In this project, an, additively manufactured bluff-body burner for the fuel-flexible, stable and safe combustion of NH3/H2 mixtures is considered. Accurate numerical simulations and detailed experiments are carried out to investigate the combustion characteristics and pollutant emissions. The burner design is then optimized (in terms of shape, size and position of the flame holder) to achieve efficient combustion behavior. Open and closed burner geometries are considered. The side of the flame holder in contact with the flame and other high temperature parts are produced by additive manufacturing using initially Ni-based alloys and later ultra-high temperature resistant refractory metal alloys to allow rapid geometry variations. The dynamics of the turbulent flame, the interactions between flame and wall, the limit of stable combustion, flashback and heat release are investigated. Finally, an optimal bluff-body burner design is developed for stable, safe, fuel-flexible and clean combustion of NH3/H2 as a mixed fuel., This text was translated with DeepL
2023 to 2026
Deutsche Forschungsgemeinschaft (DFG)
Pressure effects ON TEMperature stratification and circulation in lakes - PONTEM
Societal Relevance:, Providing the population with sufficient good quality water will be one of the great challenges in near future. Land use and climate change exacerbate this problem. We have only limited possibilities to create new water or transfer water in reservoirs seasonally to periods of shortage. Wise use and management of water resources appear as the most promising tools to alleviate the situation. Hence, numerical models have been adopted for lakes: the implementation of water properties however is still tied to ocean assumptions. As a consequence, simulated flows in the deep water of lakes close to temperature of maximum density (i.e. near 4°C) are flawed or entirely disconnected from reality. We have much better knowledge of the physical properties of lake waters. Numerical lake models could be substantially improved., Scientific Challenge:, Thermobaricity is controlling recirculation in deep lakes in the temperate and subpolar climate zone. Though the topic has gained interest recently in oceanography, the features in deep lakes have not been properly dealt with. By definition, the convenient property of potential density is lost, when thermobaric effects are dominant. This makes stability considerations difficult to display. However, we are convinced that the description of thermobaric effects can significantly be improved. We propose to start from basics of thermodynamic approaches to stability considerations to parsimonious modelling and will complete this research programme by the implementation of a proper inclusion of thermobaricity in numerical models to demonstrate the effects in some prominent cases., We hypothesize that an inclusion of thermobaricity in numerical models solves this issue and thermobaric effects are properly reflected.
2021 to 2026
Deutsche Forschungsgemeinschaft (DFG)
"Die durch endotheliale Zellen vermittelte metabolische Maladaption von CLL-Zellen kontrolliert die therapeutische Resistenz und die immunologische Flucht"
Die chronisch lymphatische Leukämie (CLL) ist die häufigste Leukämie im Erwachsenenalter. In diesem Projekt wird untersucht, ob der Kontakt zu Endothelzellen (EZ), die Widerstandsfähigkeit von CLL-Zellen gegenüber konventionellen und immunbasierten Therapien verändert. Das bessere Verständnis der zugrunde liegenden Mechanismen könnte uns dabei unterstützen, die Effektivität der Behandlung noch weiter zu verbessern.
2024 to 2026
Deutsche Forschungsgemeinschaft (DFG)
A simplified model of the coupled linear anisotropic distortion gradient elasticity and its applications to applications to the solution of various boundary value problems
The objectives of the research project are to develop simplified anisotropic constitutive relations within the coupled distortion gradient elasticity, to determine corresponding scale parameters, to apply such modeling to the solution of some boundary value problems where classical elasticity has its limitations, and to prove that these limitations can be overcome. In detail it is investigated:, - Homogenization problems considering the size effect are considered. In particular, limits as in Voigt and Reuss and as in Hashin-Shtrikman are obtained for particulate composites using the principles of minimum potential energy and complementary energy, effective properties of fiber-reinforced and particulate composites are considered in the framework of the coupled anisotropic, The distortion gradient elasticity is evaluated., - Crack problems with plane distortion, i.e. crack problems with Mode I, II and III, as well as problems with, with a crack at the edge are examined., - Problems with concentrated forces, in particular with a half plane loaded on the surface, a force applied in the interior and on the free edge of the plate are analyzed within the framework of the theory., For all problems, the influence of the coupling term and the anisotropy of the material properties on the solutions, the deviation of the solutions from the predictions of the classical elasticity and from the uncoupled distortion gradient elasticity are investigated. The results are compared in the context of the results available in the literature and, analyzed., This text was translated with DeepL
2024 to 2026
Deutsche Forschungsgemeinschaft (DFG)
Energy Focusing of Cavitation Bubbles in Flows near Boundaries
Cavitation bubbles are mostly empty bubbles that frequently occur in high-speed liquid flows. After reaching a maximum volume, they shrink in an accelerated fashion. During this so-called collapse, cavitation bubbles focus the kinetic energy of the liquid, giving rise to localized high temperatures and pressures. If this occurs near a rigid structure, i.e. a hydrofoil or the blades of a pump, they may be eroded. Although the ability of cavitation bubbles to focus energy has received a lot of scientific attention, the effect of an external flow on this phenomenon has hardly been investigated. Yet our recent findings point out that slight asymmetries during the collapse, e.g. due to a background flow, can enhance the energy focusing drastically. Although most cavitation occurrences in real-world applications are in the presence of a flow, their effect on the energy focusing and in particular on erosion has not been studied on a single bubble level. In the present proposal, we want to elucidate the importance of flows on bubbles collapsing near rigid boundaries. For this, we expose cavitation bubbles to two kinds of flows: a stagnation point flow induced by a submerged wall jet, and pressure driven shear flows. The shear flows studies are split into a simple planar flow and a radially expanding shear flow. We will utilize high-speed imaging, high bandwidth acoustic measurements, axisymmetric Volume-of-Fluid simulations, and analysis of the eroded volume with confocal laser scanning microscopy. The aim is to understand how a flow affects the energy focusing, thus if certain flows prevent or enhance cavitation erosion. The implications of such findings would be significant. They could guide cavitation erosion models in computational fluid dynamics for more realistic effects of single bubble collapse. Also, the design of cavitation-prone flows such as through narrow constrictions of nozzles, propellers, flow bends, or even for artificial heart valves would benefit from the understanding of how to avoid erosion. More importantly, adding a background flow could help to enhance energy focusing to achieve beneficial effects from cavitation. This could be nanoparticle generation, cavitation peening of materials, or increased efficiency in sonochemical reactors. Thus, we see this proposal as a starting point in a research field that has limited activities so far, but yet has high impact potential.
2023 to 2026
Deutsche Forschungsgemeinschaft (DFG)
Long-lasting consequences of early-life influenza A virus infection for the tissue-resident memory T cell niche and susceptibility to secondary infections (TRR359, Teilprojekt A05)
Mit der Geburt wird das Immunsystem des Neugeborenen plötzlich mit einer großen Anzahl von Mikroorganismen ausgesetzt und Infektionen finden in der frühen Phase nach der Geburt häufig statt. Unser Projekt ist Teil des Transregio TRR359 „Perinatale Entwicklung der Topologie der Immunzellen“ ist, dessen Ziel die Erlangung eines besseren Verständnisses der komplexen Anpassungen des frühen Immunsystems auf Infektionen und andere äußere Einflüsse ist. Unser Teilprojekt untersucht, welche langfristigen Konsequenzen eine Influenzainfektion kurz nach der Geburt auf die Zusammensetzung und Funktion von lungenresidenten Zellen (u.a. alveolaren Epithelzellen, Makrophagen und bestimmte T-Zellsubpopulationen) hat und wie sich dieses auf den Verlauf bakterieller Lungeninfektionen später im Leben auswirkt.
2024 to 2026
Deutsche Forschungsgemeinschaft (DFG)
Junior Research Group in the Emmy Noether Program (2nd funding phase)
Both dust flames and industrial cell cultivations often exhibit carrier flows that are turbulent. Turbulence is an apparently random movement of the carrier fluid caused by small disturbances. Since turbulence influences the small-scale momentum, mass and heat exchange between the carrier medium and the dispersed particles, our focus in the second funding section is on the question of how this influence affects large-scale prediction parameters such as the oxide particle size distribution or the number of cells? To answer this question, the equation of motion, which describes the behavior of the particle population, is embedded in a higher-level statistical description. One advantage of this nested approach is that expressions for chemical reactions and for gas-particle mass and heat exchange, which were determined in laminar flows, remain valid and can be treated in a closed way., Finally, the complete modeling framework is used to assess the pollutant and oxide particle output of a turbulent dust flame and to predict both the spatial microcarrier distribution in a bioreactor and possible substrate limitations. For validation purposes, we use comparisons with existing experimental measurements., This text was translated with DeepL
2024 to 2026
Deutsche Forschungsgemeinschaft (DFG)
Computational methods for wave-type problems with non-standard boundary conditions
This project deals with the numerical analysis of hyperbolic problems such as the wave equation in connection with non-trivial boundary conditions. These include kinetic as well as acoustic boundary conditions and can - in contrast to Dirichlet or Neumann boundary conditions - reflect the behavior at the boundary in a special way. This possibility is indispensable when it comes to modeling special properties of the boundary dynamics, as is the case with the membrane of a drum, for example., The numerical methods to be constructed and analyzed in this project are based on a reformulation of the problem as a partial differential algebraic equation. This means that the dynamics on the boundary is considered as an independent system, which is then coupled to the wave equation in the interior of the domain. This alternative formulation allows the choice of different grid widths or even completely different discretization approaches in the interior and on the boundary. This in turn promises significant numerical advantages if strong oscillations play a role on the boundary., This text was translated with DeepL
2023 to 2026
Deutsche Forschungsgemeinschaft (DFG)
Ein robustes, reliables und multimodales KI-System zur Schmerzquantifizierung
In Deutschland leiden mehr als 1,7 Millionen Menschen an einer Demenz. Da diese von kognitiven Einschränkungen betroffen sind, sollten hier Fremdeinschätzungsinstrumente für die Schmerzerkennung eingesetzt werden, da bei dieser Patientengruppe die Selbstauskunft keine verlässliche Information darstellt. Daher ist die Schmerzerkennung bei Demenz eine große Herausforderung für das klinische Monitoring und wird dies auch auf unabsehbare Zeit bleiben. Somit ist die, Entwicklung eines Systems zur Schmerzerkennung und -quantifizierung von großer Relevanz für zahlreiche Anwendungen im klinischen Umfeld, welches die Forderungen nach Robustheit und Zuverlässigkeit erfüllt. Zum Beispiel wäre dies in der Notfall- und Akutmedizin wünschenswert, um bei der Diagnosefindung eine derartige technische Unterstützung durch ein KI-System vorzusehen. Das Vorhaben wird die, Entwicklung eines robusten, reliablen und multimodalen KI-Systems zur Schmerzerkennung und –quantifizierung adressieren. Es beschäftigt sich, erstens, mit dem Forschungsziel tiefe neuronale Netze und Transferlernen mit umfangreichen, bestehenden in-the-wild Datenbanken zum Anlernen von diversen Mimikmerkmalen und zur Erhöhung der Robustheit gegenüber verschiedener, in verfügbaren Schmerzdatensätzen unterrepräsentierter Varianzen (Erscheinungsbild, Beleuchtung, Teilverdeckung, etc.) einzusetzen, um die Grundlagen für eine Technologie zu schaffen, die für die zukünftige potentielle Verwendung im klinischen Umfeld mit Schwerpunkt der Applikation bei Demenzkranken, insbesondere für das postoperative Monitoring in Aufwachräumen, geeignet ist.
2023 to 2026
Deutsche Forschungsgemeinschaft (DFG)
FlexiDS 2.0: Directed growth behavior of novel eutectic V-Si-B alloys - characterization and properties for high temperature applications
V-Si-B, alloys have been the focus of scientific material development for several years. Due to their, outstanding specific mechanical properties, , these alloys represent a promising alternative to Ni and Mo-based materials in the field of high-temperature alloys. In terms of its microstructure, the V-Si-B alloy system has some interesting similarities with the well-studied Mo-Si-B sister system. Both alloy systems form a ternary eutectic in the metal-rich region (e.g. vanadium) from a solid solution, V(Mk), and the two intermetallic phases V3Si and V5SiB2. Directional solidification allows the, eutectic to be "grown" along the direction of solidification, which results in a, strong directional dependence of the resulting mechanical properties (strength, creep resistance). Similar to Ni-based superalloys, these could be specifically adjusted for an application-relevant load case. The proposed project investigates the microstructure formation and the resulting properties (direction-dependent strength and creep properties) of directionally solidified, novel eutectic V-Si-B alloys. For this purpose, the, zone melting process, will be investigated and analyzed both ex-situ and the direct transition from the liquid to the solid phase at the moment of directional solidification in-situ., This text was translated with DeepL
2024 to 2026
Deutsche Forschungsgemeinschaft (DFG)
Laser-induced cavitation near a rigid boundary in a sound field
avitation denotes the formation of bubbles far from their equilibrium size, i.e., they are expanded to a much larger size than their rest radius. This can be achieved by either depositing energy in the liquid that explosively expands a void in the liquid (termed cavitation nucleation by energy deposition), or by supplying a low pressure or a tension such that a bubble expands from its equilibrium radius to a considerably larger size (termed cavitation by tension). For cavitation bubbles generated by either method, once reaching their maximum size they shrink in an accelerated fashion and focus energy from the liquid thereby compressing the bubble content to enormous pressures and temperatures, initiating chemical reactions, emitting shock waves, accelerating liquid jets, and eroding any material nearby., The advantage of cavitation through energy deposition is the excellent control of later bubble dynam- ics. Meanwhile, tension can be more easily achieved, for example, in an ultrasound field. The present proposal is a continuation of the successful DFG-funded project OH 75/4-1 ending in September 2023. In that project, a solver was developed that accounts for the fluid-structure interaction between a collapsing or expanding cavitation bubble and a linearly elastic solid using direct numerical simulations. The solver is embedded in the OpenFOAM framework and uses the Volume-of-Fluid method. Next, we want to uti- lize this solver together with straightforward experiments to unravel the non-spherical cavitation bubble dynamics in an ultrasound field. Our focus lies in the interaction of the cavitation bubble with the sound field in the presence of a single nearby boundary as well as in a confined liquid filled gap. The cavitation bubble is generated with a laser pulse in the sound field of an acoustic horn (sonotrode). The project is split into three work packages. First we want to understand the importance of phase, pressure, and position of the bubble in a standing wave sound field on the non-spherical bubble dynamics. Then, the bubble will be generated close to a boundary where the attractive force of the boundary competes with the acoustic pressure gradient. This will lead to a complex boundary layer flow that we will resolve. The third part of the proposal studies thin gaps where the bubble dynamics are confined. Significant erosion is observed in thin gaps, and the aim of the third part is to understand the kind of bubble dynamics that cause it., All three work packages include experiments and simulations. The validated simulations will provide details about the forces and fluid flows that are difficult to resolve in the experiments.
2023 to 2026
Deutsche Forschungsgemeinschaft (DFG)
Multimodale KI-basierte Schmerzmessung bei Intermediate Care Patienten in der postoperativen Phase
Das Vorhaben beschäftigt sich mit Methoden der künstlichen Intelligenz zur automatisierten, multimodalen und kontinuierlichen Messung der Schmerzintensität in einer postoperativen Umgebung auf einer Intermediate Care Station nach größeren operativen Eingriffen. Langfristig soll die Technologie für Patienten mit eingeschränkten Kommunikationsfähigkeiten eine bessere Behandlung der Schmerzen und ihrer Ursachen ermöglichen, indem sie das medizinische Personal bei der Schmerzbeurteilung durch ein automatisiertes Echtzeitschmerzmonitoring unterstützt und entlastet sowie eine präzisere, individual- und situationsspezifische Analgesie möglich macht. Perspektivisch könnte die Technologie in weiterführenden Projekten auch für andere Patientenkollektive (z.B. Kinder und Demenzerkrankte) weiterentwickelt, validiert und eingesetzt werden.
2022 to 2026
Deutsche Forschungsgemeinschaft (DFG)
Peridynamic Modeling, Identification and Validation of Laminates Responses Beyond Damage Initiation
With the development of advanced manufacturing technologies,composite materials and laminates are widely used in engineering asthey are advantageous over traditional materials. While the deformation behaviour up to the damage initiation can be predicted bythe classical continuum mechanics with satisfactory accuracy,analysis of progressive failure beyond the critical damage state is still a major challenge. Peridynamics (PD) as a non-local continuum mechanics theory is very suitable for analyzing discontinuous problems such as material failure, crack initialization, crack propagation, crack patterns formation and crack interactions. Based on the recent activities of the research group (RG) in OvGU Magdeburg on PD modeling of crack patterns in float glass,identification of long-range forces in peel films, this project aims to contribute novel formulations for composite laminate structures to offer engineers an alternative solution to tackle fracture problems. A novel PD damage constitutive modeling framework to describedamage initiation, damage growth and crack propagation in a unifiedmanner will be developed by RG in OvGU. Based on the previous research on float glass, the available experimental data will be appliedto identify material parameters, to capture initial distribution of flawsand to describe damage patterns in ring bending tests on glassplates. For the validation, ball drop tests will be simulated and results will be compared with experimental data. In addition, non-local models will be developed and calibrated in OvGU to capture long-range, forces observed in peel tests. By the use of the layer-wise approach the developments will be consolidated to formulate a new PD theory for laminates subjected to severe loading in the post-critical damage regime. Based on the available experimental data on laminated glass, a benchmark problem will be developed and solved to verify the theoretical developments as well as analytical and, numerical solution procedures.
2023 to 2026
Deutsche Forschungsgemeinschaft (DFG)
Structured-entities Ontology Extension
Reference ontologies play an essential role in organising knowledge in the life sciences and other domains. They are built and maintained manually. Since this is an expensive process, many reference ontologies only cover a small fraction of their domain. The goal of this project is to develop techniques that enable the automatic extension of the coverage of a reference ontology by extending it with classes that have not been manually added yet. The extension shall be faithful to the (often implicit) design decisions by the developers of the reference ontology., While this is a generic problem, our use case addresses the automatic extension of the Chemical Entities of Biological Interest (ChEBI) ontology with classes of molecules, since the chemical domain is particularly suited to our approach. We achieve our goal by using the leaf classes of the manually curated reference ontology to train a system to predict subclass relationships between mid-level classes and new classes. Thus, our method uses machine learning techniques, but – in contrast to other approaches – does not rely on text corpora as input, but utilises the content of the ontology itself. Annotations of classes that provide information that are relevant for the classification of a given entity within the ontology play a key role in this learning task. E.g., in the case of ChEBI these are annotations that represent the structure of chemical entities (e.g., molecules and functional groups)., In addition, the axioms of the ontology are represented as logical neural networks, which are used during the training of prediction models. Thus, our approach for ontology extension provides a kind of neural-symbolic integration. In our previous work we have established the feasibility of the approach by comparing the performance of a number of machine learning approaches at subclass prediction. In spite of the limitations of this initial work, the performance of some of our models compare positively to ClassyFire. The latter is a rule-based system representing the state of the art for this task, and is already being used in the development of hEBI. Furthermore, our results show that different machine learning approaches are suited for different kinds of chemical entities. Thus, we plan to use an ensemble approach in our project., The outcomes of this project will be (a) a benchmark training set for training models for chemical ontology extension, and (b) a system that – when provided with a set of new chemical entities as input – will automatically generate a new ontology that extends ChEBI to cover these entities. The benefit of this work is a novel methodology for extending the coverage of existing reference ontologies. If adopted, it will allow improved interoperability and knowledge integration for the communities that use these reference ontologies. Another benefit will be a novel neural-symbolic architecture, integrating graph neural networks, transformers and logical neural networks., The project is a cooperation project with Prof. Dr. Janna Hasting (University of Zurich) as part of the DFG’s Weave Lead Agency process.
2022 to 2026
Deutsche Forschungsgemeinschaft (DFG)
Timing and valence reversal: Which individual dopaminergic input neurons into the mushroom body are sufficient? (FOR 2705: Decoding a brain circuit: structure, plasticity and behavioral function of the Drosophila mushroom body)
Obtaining rewards and avoiding punishment are powerful goals of human and animal behavior. To this end, humans and animals have developed mechanisms to predict the occurrence of rewards and punishments. These mechanisms have been intensively researched and are now well understood in principle. However, the entire flip side of the learning processes via rewards and punishments is usually not taken into account. Namely, it is equally crucial to learn stimuli that predict the loss of a reward or the exposure to a punishment! In fact, it feels good to receive a reward, but it is unpleasant when it is withdrawn. Accordingly, stimuli that are linked to the receipt or loss of rewards are learned as positive or negative. And the same applies to punishments: being punished is immediately bad, but it is "nice when the pain subsides". This so-called valence reversal is a fundamental characteristic of the processing of reward and punishment, but its neurobiological mechanisms are still completely poorly understood. Since dopaminergic neurons play an important role in reward and punishment processing throughout the animal kingdom, including humans, we aim to exploit the unique experimental capabilities of the simple nervous system of the fruit fly Drosophila to investigate the role of individual identified dopamine neurons in valence reversal. We want to understand how one and the same experience can cause two opposing memories - namely for stimuli that precede it, or which are linked to its end. To this end, we combine high-resolution behavioral experiments with methods of optogenetics and our latest findings on the synaptic connectome of the learning center in the Drosophila brain, the so-called mushroom body., This text was translated with DeepL
2023 to 2026
Deutsche Forschungsgemeinschaft (DFG)
Incipient spray fluidized bed agglomeration at the border to coating
The project aims to track the border between spray fluidized bed agglomeration and coating, which are the important key processes for advanced particle engineering. We will investigate experimentally agglomeration in the vicinity of this border (borderline agglomeration), focusing on the starting period of it (incipient agglomeration), in which dimers (to single particles stacked together) are formed from primary particles. The main focus is on simplest agglomerate structure and clearest conditions of spray fluidized bed agglomeration process. The process will also be described by modeling. Here, we can capitalize on own Monte Carlo models, which are stochastic and discrete, able of representing micro-scale events and processes. The goal is to radically improve these models. So the crucial model constituents will be revised, namely the sub-models for breakage and drying, based on separate experiments without spraying (for breakage) or without binder in the spray (for drying). The criterion for aggregation or rebound after wet collision will also be revisited, though still based on normal momentum dissipation. The improved model will provide direct and unconditional access to the agglomeration-coating border, making regime maps obsolete.
2023 to 2026
Deutsche Forschungsgemeinschaft (DFG)
Additively-manufactured bluff-body burner investigated by high-fidelity simulations and experiments for fuel-flexible, stable, and safe combustion of NH3/H2 mixtures
This project investigates an additively-manufactured bluff-body burner for fuel-flexible, stable and safe combustion of NH, 3, /H, 2, mixtures. High-fidelity numerical simulations and detailed experimental investigations are carried out to study combustion and pollutant emission characteristics in this burner. The burner design is then optimized (with respect to bluff-body shape, size and position) to achieve an efficient combustion behavior. Open and confined burner geometry will be considered. Flame-side bluff-body and other high-temperature parts are produced by additive manufacturing using Ni-based alloys and ultra-high temperature resistant refractory metal-based alloys to enable geometry variations. Turbulent flame dynamics, flame-wall interactions, blow-off, flame flash-back events, and heat release are investigated in detail. Finally, an optimal bluff-body burner design will be obtained for stable, safe, fuel-flexible, and clean combustion of NH, 3, /H, 2, as blend fuel.
2023 to 2026
Deutsche Forschungsgemeinschaft (DFG)
The pulvinar nuclei as a computational system: Computing and calibrating the organization of 3-D visual space
Project in DFG Priority Program SPP2411, We present a novel hypothesis of the functions of the pulvinar in the primate and make proposals for specific tests to probe predictions of this hypothesis. The pulvinar nuclei are greatly enlarged in primates compared with other mammals. We advance the view that the pulvinar may function as a computational system that is specifically suited to adaptive computation. As a specific case of this general hypothesis, we will examine how the pulvinar and its connected neocortical areas may support the structuring of 3-D spatial relationships in the visual world. Information about the 3-D structure of the immediately visible world is important for both sensory, perceptual judgments about the size, shape and position or objects, but also for motor activity, particular the control of eye movements. In humans, such movements are inherently binocular in nature and therefore embedded in 3-D spatial processing. Few, if any, studies of the pulvinar nuclei have examined binocular 3-D properties of pulvinar neurons. By contrast, there has been extensive study of the binocular function of sensory cortical areas. We seek to build upon the current canonical view that the pulvinar nuclei provide a relay or ‘efference copy’ of cognitive signals such as spatial attention. This project will test the hypothesis that the pulvinar relay applies a transform to neuronal signals about 3-D spatial relationships as they pass from one visual cortical area to another. We will make dual electrophysiological recordings from the pulvinar nuclei and anatomically connected visual cortical areas The project will test the adaptive, regulatory role of the pulvinar by employing standard visuomotor adaptation paradigms, in combination with interventions that aim to temporarily and reversibly disrupt pulvinar function.
2022 to 2026
Deutsche Forschungsgemeinschaft (DFG)
Freiheit & Sicherheit - Diskurse um Äußere und Innere Sicherheit in Deutschland seit 1990. - Teilprojekt in der Forschungsgruppe "Kontroverse Diskurse. Sprachgeschichte als Zeitgeschichte seit 1990"
Das Projekt wird in der ersten Förderphase vorwiegend an der Universität Trier durchgeführt, während die zweite Förderphase an der OvGU Magdeburg vorbereitet wird., Das Teilprojekt erweitert in der ersten Förderphase die narrative Sprachgeschichte kontroverser Diskurse um die Äußere Sicherheit bis etwa 1990 um die Untersuchung seitheriger Diskussionen insbesondere um Bundeswehreinsätze und Beteiligungen und Nicht-Beteiligungen an weltweiten militärischen Aktionen. Dies wird verknüpft mit der Fragestellung, in welcher Weise in solchen öffentlichen Diskussionen "Freiheit" und "Sicherheit" zur Legitimation oder Ablehnung anstehender Entscheidungen herangezogen wurden. Das schwierige Verhältnis von, Freiheit, und, Sicherheit, steht auch in der geplanten zweiten Förderphase im Mittelpunkt, in der ein weiteres inhaltliches Feld, das der Inneren Sicherheit, betrachtet werden soll. Denn im Untersuchungszeitraum werden Diskussionen um Militäreinsätze, um die Äußere Sicherheit, mit der die Freiheiten einer demokratischen Gesellschaft gesichert werden sollen, oft verknüpft und legitimiert mit der Bekämpfung von internationalem "Terrorismus". Das verzahnt sie sehr eng mit auf die Innere Sicherheit ausgerichteten Überlegungen zum Schutz vor "Terror". Eine übergreifende Frage beider Förderperioden lautet daher: Welche Spannungen baut das neue sicherheitspolitische Selbstverständnis der Bundesrepublik, das um den Begriff der Sicherheit kreist, zum hochgradig ambigen Freiheitsbegriff auf? Dieses Verhältnis als eine diskursive Grundfigur demokratischer Diskurse über die Zeit hinweg an den Diskussionen um die sog. Äußere und Innere Sicherheit zu ergründen und zu beschreiben, verspricht Einsichten auch in andere gesellschaftliche Themenfelder. So steht auch in den aktuellen Corona-Debatten das Verhältnis von - in diesem Fall gesundheitlicher - Sicherheit und Freiheit zur Disposition ebenso wie in Debatten um Datenschutz oder Umweltschutz. In der ersten Förderperiode aber steht die, Sicherheit, vor Gefahren von außen sowie die Behauptung der weltweiten Bewahrung und/oder Wiederherstellung von, Freiheit, und, Menschenrechten, im Fokus der Untersuchung, weil - so die Ausgangshypothese - vor allem mit diesen Hochwertworten um die (De-)Legitimation von Militäreinsätzen, Rüstungsausgaben sowie anderen Beteiligungen und Nicht-Beteiligungen Deutscher an internationalen multilateralen Aktivitäten gestritten wurde., Daneben trägt das Teilprojekt zum methodologischen Ziel der Projektgruppe der Entwicklung einer kollaborativen digital gestützten Diskursanalyse bei. Dafür wird das Teilprojekt vor allem qualitative Interpretationen der sich wandelnden Bedeutung von Schlüsselwörtern (z.B. mit framesemantisch inspirierten Analysen), der Wirklichkeitskonstruktionen durch Metapherngebrauch, von metasprachlichen Äußerungen und von seriell genutzten Argumentationsmustern so weiterentwickeln, dass über Annotationen in den Korpusdatenbanken auch diachrone quantitative Vergleiche ermöglicht werden.
2023 to 2026
Deutsche Forschungsgemeinschaft (DFG)
DAMP activation and orchestration of cytokine storm by the cold shock protein
Acute kidney injury is a common sequela of diseases associated with blood pressure decrements, such as septicemia or hypoxia. Dead cells and activated tissue resident cells trigger an immune response with subsequent organ failure that represents a complex intermingled process. The focus of this application is to elucidate common underlying mechanisms and cell responses. In sepsis, soluble factors released by bacteria into the blood, circulate as pathogen-associated molecular patterns (PAMPs) and incite local and systemic inflammatory responses. PAMPs are recognized by pattern recognizing receptors (PRRs) and activate NF-κB signaling, leading to increased expression of damage-associated molecular patterns (DAMPs). DAMPs are released from the nuclear, mitochondrial, or cytoplasmic compartments following inflammasome activation, pyroptosis, necroptosis, or by exosomes. DAMPs initiate and sustain a noninfectious inflammatory response that is associated with systemic inflammation, organ damage, and cell death., Y-box binding protein-1 (YB-1) is a mediator of local and systemic inflammatory responses. Inflammatory stimuli, such as LPS and hypoxia, trigger intracellular upregulation as well as YB‑1 secretion., Wild type, and whole body, Ybx1, knockout mice (, Ybx1, Δ, RosaCreERT, ) were challenged with LPS. While the majority (70%) of, wild type, mice die, 75% of, Ybx1, knockout mice survive. Changes in the inflammatory milieu show that YB-1 is not only present in the secretome but also regulates the composition. These findings form the basis for the present work program, in which the role of YB-1 in DAMP activation and orchestration of cytokine storm will be investigated. The following questions will be addressed: (i) Which DAMPs are regulated by YB-1 in a cell-specific manner? Comparative studies of secretomes in different cell types of, wild type, and, Ybx1, knockout, mice will be performed. (ii) What is the contribution of YB-1 for DAMP-dependent cell-cell communication in, in vitro, models? (iii) What is the, in vivo, relevance of YB-1 for damage perpetuation and protective effects in an ischemia/reperfusion model. Chimeric bone marrow animals with YB-1, wild type, and YB-1-deficient cells will be generated. The secretome data will be analyzed for cell-specific protective factors as well as damage markers. These data will be used to design therapeutic strategies. Two approaches are envisioned: 1. Blockade of LPS and hypoxia-induced damage markers (DAMPs, cytokines) by inhibiting YB-1 activities and 2. To introduce the identified protective factors as an intervention strategy., In summary, the project proposal will expand our understanding of inflammatory secretomes, with a focus on a centrally acting molecule of the cold shock protein family. The results will be translated into intervention strategies to ameliorate acute kidney injury and initiate tissue regeneration.
2023 to 2026
Deutsche Forschungsgemeinschaft (DFG)
Rolle von kortikalen-subkortikalen Schleifen bei der Erkennung von Geruchsreizen sowie der Trennung von Vordergrund- und Hintergrunddüften...
Der olfaktorische Bulbus (OB) ist die erste Verarbeitungsstation für Geruchsinformationen im Gehirn. Dieses subkortikale Gebiet sendet Informationen an mehrere kortikale olfaktorische Zentren und erhält direkte Rückprojektionen, die umfangreiche kortikale-subkortikale Schleifen bilden. Bislang ist die genaue physiologische Funktion dieser Schleifen nur unzureichend beschrieben. Eine prominente Theorie, die auf der Grundlage von Computermodellen entwickelt wurde, besagt, dass olfaktorische kortikale-subkortikalen Schleifen die durch den Geruch hervorgerufene neuronale Aktivität an den OB zurückspiegeln und dadurch die Erkennung von "Vordergrund"-Gerüchen in einem verrauschten Dufthintergrund verstärken. Diese "Vordergrund-Hintergrund-Trennung" ist für viele sensorische Verarbeitungsmodalitäten wesentlich. In diesem Tandemprojekt zwischen den Rothermel und Schwarz Labor werden wir die reziproke neuronale Aktivität zwischen dem OB und den zugehörigen kortikalen Zentren untersuchen, um ihren Beitrag zur Erkennung von Geruchsreizen sowie der Trennung von Vordergrund- und Hintergrunddüften aufzudecken. Insbesondere werden wir die kortikalen Schleifen, die zwischen dem OB und dem vorderen olfaktorischen Nukleus (AON) sowie dem OB und dem vorderem piriformen Kortex (APC) gebildet werden, funktionell vergleichen. Zu diesem Zweck werden wir eine gleichzeitige 2P-Ca2+-Bildgebung von kortikalen Fasern und OB-Ausgangsneuronen verwenden (Ziel 1), um ihre räumlich-zeitliche Beziehung bei verschiedenen Geruchsaufgaben zu untersuchen. Die Daten aus diesen Experimenten werden zur Verfeinerung bestehender OB-olfaktorischer Kortex-Modelle verwendet (Ziel 2). In Ziel 3 werden wir eine aktivitätsabhängige Markierung der Zellen des olfaktorischen Kortex etablieren. Die geruchsabhängige Markierung aktiver AON- und APC-Neuronen wird es uns ermöglichen deren reziproke Projektionen mit dem OB in noch nie dagewesenem Detail mit Hilfe der Lichtblatt-Fluoreszenz-Expansionsmikroskopie (LSFEM) zu untersuchen. Schließlich wird die Expression von optogenetischen Aktuatoren in aktivitätsmarkierten Neuronen es uns ermöglichen, die kausale Beziehung der AON/APC-Aktivität bei der Geruchserkennung und der Trennung von Vordergrund- und Hintergrunddüften zu untersuchen (Ziel 4). Eine erfolgreiche Umsetzung dieses Projekts wird unser Verständnis der physiologischen Funktionen von OB-kortikalen Schleifen für die Geruchsverarbeitung und geruchsgesteuerte Verhaltensweisen grundlegend verbessern.
2022 to 2026
Deutsche Forschungsgemeinschaft (DFG)
SFB1315 B06
The proposed project aims at understanding how systems level hippocampally-related functional connectivity as well as cortico-cortical microstructure changes indicative of memory engrams develop during memory consolidation. We will use a novel and unique 7T connectome MRI for humans to achieve the highest to-date possible resolution for functional and diffusion magnetic resonance imaging (MRI). This will allow imaging of the emergence of cortico-cortical connectivity and engram-related plasticity in a layer-specific manner in early and late stages of memory consolidation, thereby narrowing the gap between an animal-led and human-led understanding of memory consolidation. As neuromodulatory inputs related to more or less salient memory events are one of the most prominent drivers of the long-term stability of memories we will additionally investigate how a stronger involvement of neuromodulatory and ‘saliency-processing structures’ affects memory consolidation. Moreover, we will assess whether semantic congruency affects the time course of dynamics in the memory consolidation network or memory engram formation.
2022 to 2026
Deutsche Forschungsgemeinschaft (DFG)
Vascular resistance and resilience in ALS – an ultrahigh-resolution 7T MRI study of the motor cortex
Amyotrophic lateral sclerosis (ALS) is a rapidly progressive neuromuscular disorder hallmarked by pyramidal cell degeneration of the motor cortex (M1). The underlying causes of sporadic ALS remain largely unknown, limiting its treatment options to supportive measures without any causal therapies. Even though many patients die within 3 to 5 years through respiratory insufficiency, individual ALS disease course and prognosis are highly variable. This is mirrored by distinct motor phenotypes, very long survival times of up to 10 years, and cessation or even reversal of disease progression in individual patients.In the presented proposal we hypothesize that a root cause of clinical ALS heterogeneity is a variable vascular supply of the motor cortex, which mitigates M1 pyramidal cell degeneration (“resistance”) or its impact on motor function (“resilience”). To address this question, we will prospectively examine a selected cohort of 20 ALS patients and 20 age- and sex-matched controls that will undergo 7 Tesla ultra-high field magnetic resonance imaging (MRI) applying angiographic (ToF-MRA) and anatomical sequences (MPRAGE). By visual rating two vascular patterns of M1 supply will be distinguished for the branches of the anterior cerebral artery (medial motor cortex) and middle cerebral artery (lateral motor cortex), respectively: a “single supply” pattern in which the M1 supply is provided by the terminal cortical arteries of one single branch only, or a “double supply” pattern, in which two branches feed the supplying terminal cortical arteries. We assume that a “double supply” pattern results in overlapping perfusion territories of both branches which mitigate M1 pyramidal cell degeneration or its impact on motor function. For quantitative analysis vessel distance mapping will be applied, which assigns each non-vessel voxel the distance to each of the examined arteries and thus consequently allows an approximation of the branches’ perfusion territories. Based upon mediation models the direct effects of the vascular supply patterns and perfusion territories on pyramidal cell degeneration (studied using M1 cortical thickness, global and body-part specific) will be assessed, as well as whether their severity mediates the influence of vascular supply patterns and perfusion territories upon motor function (global and body-part specific), both, at the time of the baseline MRI and longitudinally.Vascular patterns could serve as a new marker to explain the phenotypic variability in ALS, which might prove useful as an additional aspect for an individualized patient counseling regarding disease course and prognosis. Additionally the cerebral vasculature is potentially “dynamic” tissue, whose functionality can be modified through lifestyle and certain drugs. A “vascular approach to therapy” might lead to new avenues in the prevention and treatment of ALS.
2023 to 2026
Deutsche Forschungsgemeinschaft (DFG)
Binaural infrasound perception
An increasing number of individuals are being exposed to infrasound, e.g., due to the energy transition. This can lead to a significant reduction in the quality of life due to a range of complaints (sleep disturbances, concentration disorders, restlessness, migraines). Several studies indicate that infrasound is perceived by the auditory system. How infrasound is processed by the auditory system is still largely unclear. For example, it is not yet clear to what extent the concepts of binaural perception known from the classical audible frequency range can be transferred to the infrasound perception. Insights into binaural processing are of great interest because environmental sounds usually reach both ears and the brain has to form from the signals arriving at both ears a unified percept. The goal of the project is to describe aspects of the binaural perception of infrasound experimentally and with models, so that in the future the effects of infrasound on humans can be better studied., At the beginning of the project, a binaural reproduction system will be developed on the basis of an already established low-distortion reproduction system, which is designed for monaural infrasound reproduction. In listening tests, this binaural reproduction system is then used to determine thresholds in quiet (infrasound without background noise) and masking thresholds (infrasound in the presence of background noise). It is tested if concepts for binaural processing in the classical audible frequency range are also valid in the infrasound frequency range. These concepts include not only an improvement of perception by binaural presentation (binaural integration) but also that the auditory system is able to better detect a target signal in the presence of a noise by comparing the two ear signals (binaural unmasking). In addition, it will be investigated whether listeners can also perceive binaural beats for infrasound stimuli, which, in the classical audible frequency range, are seen as further evidence for specific binaural processing. For the aspect of binaural beats, in addition to auditory experiments, the electrical response of the brain is recorded by electroencephalography (EEG). Based on the experimental results, models of binaural infrasound perception will be developed., The long-term goal is to use the findings of the project for the protection against possible health damages caused by infrasound and the adequate description of the emission of infrasound sources. The findings will thus be of importance both for health protection in general and specifically with regard to the energy transition (infrasound emissions from heat pumps, wind turbines, and other technical facilities).
2023 to 2026
Deutsche Forschungsgemeinschaft (DFG)
Development of unspecific peroxygenases for the ß-hydroxylation of amines on a preparative scale.
We are convinced that unspecific peroxygenases (UPOs) are excellent enzymes for C-H functionalization with an extraordinary synthetic potential. By combining protein and process engineering, we aim to demonstrate the potential of UPOs by synthesizing pharmaceutically important building blocks on a gram scale. UPOs are fungal enzymes that transfer a peroxidic oxygen to sp3 carbons and have an impressive substrate diversity with more than 400 known examples. They exhibit excellent enantioselectivities and impressive total turnover numbers of up to 300,000 for benzylic hydroxylations. About four thousand putative UPO genes have been annotated, but less than 20 different UPO enzymes have been studied in detail due to their difficult heterologous expression. These production limitations have also significantly hampered the targeted development of these proteins, so that the current substrate palette consists mainly of wild-type activities. It would be of utmost importance to utilize the catalytic machinery of UPOs for new industrially relevant substrates. In particular, substrates with aliphatic amines are ubiquitous in active pharmaceutical ingredients (APIs), but there are few examples of UPOs that hydroxylate these compounds. The vicinal amino alcohol class of molecules is of particular interest as these groups of UPOs could be synthesized from amines and represent exciting scaffolds for the pharmaceutical industry. The proposed research project directly addresses the current limitations of UPOs to amine substrates and aims to utilize an integrated approach of biochemistry and process engineering for the development and application of genetically engineered UPOs. In the field of protein engineering, the methodology includes the development of a rapid analytical system for the detection of aminoalcohols and a redesign of the active site including the amine-anchored regions for the design of potent amine-converting UPOs. On the process engineering side, online methods for the control of hydrogen peroxide and the integration of ion exchange and crystallization techniques are tailored to the requirements of UPO-catalyzed reactions. The implementation of the developed biocatalysts and methods will be explicitly investigated for a wide range of substrates and on a gram scale. The research project is divided into eight objectives and four milestones, which will be tackled in a structured manner by the two project partners. It begins with the development and engineering of assays, proteins, real-time analyses and selective product removal and culminates in preparative syntheses on a gram scale., This text was translated with DeepL
2023 to 2026
Deutsche Forschungsgemeinschaft (DFG)
Perception of sounds containing low-frequency tonal components
Low-frequency noise has a considerable impact on the perception of sounds. The sound sources are often manmade, e.g. compressors, car or ships. Important parts of the energy transition like wind turbines or heat pumps can also emit such low-frequency sounds. Thus, to evaluate the noise emission of environmental sounds, it is crucial to understand the perception of the low-frequency content of a sound by the auditory system. The audible low-frequency range extends from 20 Hz to around 250 Hz. The sound can be perceived as humming, rumbling or booming, if the sound contains tonal components in this range. These sensations are specific to the low-frequency range. A humming sound contains a low-frequency pure tone; if the level of this tone varies over time, it is perceived as rumbling. Does the sound contain, apart from the low frequency component, also higher tonal components it can be perceived as booming. The aim of the project is to characterise main contributions to the sensations humming, rumbling and booming. To this end, the effect of the variation of characteristic signal properties of basic signal types on the sensations is measured. The results are used to develop models of these sensations. The long-term goal is to use simulations of the sensations humming, rumbling and booming in models for noise evaluation of environmental sounds with respect to annoyance, pleasantness or quality.
2023 to 2026
Deutsche Forschungsgemeinschaft (DFG)
WSAM: Wide Synthetic Aperture Sampling for Motion Classification
We will collaborate with the Johannes Kepler University in Linz and the German Aerospace Center (DLR) in Oberpfaffenhofen. The goal of the project is the use of autonomous drone swarms for rescue applications. Here, drones can imitate the swarming behavior of birds to always have an optimal view for rescue purposes., Considering the current high level of attention that is being paid to drones, it is easy to overlook the enormous potential that they bring with them in civilian areas. Drone groups are establishing themselves worldwide in blue light organizations such as the police, fire brigade and mountain rescue to use this technology to save human lives. Search and rescue operations benefit, among other things, from the flexible, fast and - compared to helicopters - inexpensive and safe use of drones. They are also used in the inspection of disaster areas, for the early detection of forest fires, for border security, or wildlife observation. The problem with all these applications is always the occlusion caused by vegetation, such as forest, which usually makes it impossible to find, detect, and track people, animals or vehicles in single aerial photographs. This project is based on the "Airborne Optical Sectioning" (AOS) imaging method developed at the Johannes Kepler University and will study further potentials of the swarms.
2023 to 2026
Deutsche Forschungsgemeinschaft (DFG)
Daten-Segmentierung für nicht-stationäre Zeitreihen
Die Möglichkeit nicht-stationäre Zeitreihen in Segmente mit ähnlichem stochastischen Verhalten aufteilen zu können, ist eine zentrale Voraussetzung zur weiteren Analyse in vielen Anwendungsgebieten. Frühere Ansätze (Kirch, Reckruehm (2023)) arbeiten nur mit einer einzigen Bandbreite und einem Inspektionsparameter, was in der Regel zu einem Güte-Verlust führt. Eine bessere Performance ist zu erwarten, wenn die Information aus Verfahren mit verschiedenen Bandbreiten kombiniert wird (Multiskalen-Verfahren) und der Inspektionsparameter regelmäßig neu geschätzt wird. Genau hierum geht es in diesem Projekt: Hierbei muss zum einen auf computationelle Aspekte geachtet werden, zum anderen wird aber auch die mathematische Analyse deutlich komplexer.
2023 to 2026
Deutsche Forschungsgemeinschaft (DFG)
Gerätezentrum "Magdeburg UHF-MR" Core Facility
The Magdeburg UHF-MR Core Facility will provide 7T MRI technology and methodology that is unique in Europe. As the first centre in Europe, the Magdeburg UHF-MR Core Facility will operate two human 7T MRI systems, one state-of-the-art 7T MRI and one 7T “Connectome” MRI with unprecedented gradient performance. Users are scientists mainly from the field of basic, applied and clinical neuroscience from different institutions in Magdeburg as well as external researchers., The main goal is to establish and provide the best possible infrastructure, measurement methods and technologies together with professional support for all imaging researchers. The project is structured into 5 work packages:, - develop and maintain cutting edge methodology, - establish methods to ensure and monitor highest data quality, - provide training and imaging support to the users, - develop and provide digital research data management tools, - establish the organizational structure and administrative procedures, The unique 7T hardware capabilities and the available unique methodological expertise and longest standing 7T MRI experience in Magdeburg form the basis for new superb research opportunities with highest level support and service for the users.
2020 to 2026
Deutsche Forschungsgemeinschaft (DFG)
Thermomechanical ring rolling with predictive property control
Due to the large number of interacting material-physical effects, it is not yet common to produce all the desired properties in a single processing step. A multi-stage process of pre-treatment, rolling and subsequent heat treatment of the functional surfaces is therefore always necessary. From an energy point of view, it would be desirable to set as many properties as possible as close to the final state as possible during production in order to ideally be able to dispense with heat treatment. Only a few control variables are available on the machine side, but these have an interacting and non-linear effect. Conventional control is therefore difficult or impossible to implement. Predictive process control can already predict the desired end properties in the control loop on the basis of a semi-analytical model and thus provide specific control specifications., The aim of the research project is to design such a control system for integration into a real process and to parameterize the necessary models. Several components are to be interlinked: predictive modeling of the process makes it possible to provide optimal control specifications, while an in-process sensor based on the eddy current method supplies real data as a corrector., This text was translated with DeepL
2023 to 2026
Deutsche Forschungsgemeinschaft (DFG)
The pulvinar nuclei as a computational system: Computing and calibrating the organization of 3-D visual space
We present a novel hypothesis of the functions of the pulvinar in the primate and make proposals for specific tests to probe predictions of this hypothesis. The pulvinar nuclei are greatly enlarged in primates compared with other mammals. We advance the view that the pulvinar may function as a computational system that is specifically suited to adaptive computation. As a specific case of this general hypothesis, we will examine how the pulvinar and its connected neocortical areas may support the structuring of 3-D spatial relationships in the visual world. Information about the 3-D structure of the immediately visible world is important for both sensory, perceptual judgments about the size, shape and position or objects, but also for motor activity, particular the control of eye movements. In humans, such movements are inherently binocular in nature and therefore embedded in 3-D spatial processing. Few, if any, studies of the pulvinar nuclei have examined binocular 3-D properties of pulvinar neurons. By contrast, there has been extensive study of the binocular function of sensory cortical areas. We seek to build upon the current canonical view that the pulvinar nuclei provide a relay or ‘efference copy’ of cognitive signals such as spatial attention. This project will test the hypothesis that the pulvinar relay applies a transform to neuronal signals about 3-D spatial relationships as they pass from one visual cortical area to another. We will make dual electrophysiological recordings from the pulvinar nuclei and anatomically connected visual cortical areas The project will test the adaptive, regulatory role of the pulvinar by employing standard visuomotor adaptation paradigms, in combination with interventions that aim to temporarily and reversibly disrupt pulvinar function.
2023 to 2026
Deutsche Forschungsgemeinschaft (DFG)
Lazy Estimation in Networked Systems
The amount of sensor data provided by battery-driven, widely distributed devices is steadily increasing. Since sensor data are typically fed into information processing units, it is worth considering how information processing itself can be exploited to reduce communication and energy demands. For this purpose, this project focuses on information-processing techniques that can incorporate implicit information conveyed by the transmission mechanism. Although a sensor node decides not to send its data, the receiver can still leverage the absence of data to update its state estimates. For instance, sensor readings can be compared against a threshold to decide for a transmission. The receiver can translate this decision rule into information about the data although no transmission took place. Sender and receiver can negotiate such decision rules in order to minimize communication costs, on the transmitting end, and to maximize the retrievable information, on the receiving end. Since threshold-based strategies are far too restrictive for time-varying systems being observed, model-based and data-driven policies will be investigated., This project primarily investigates stochastic decision rules to trigger transmissions. In contrast to deterministic triggers, stochastic mechanisms can preserve the Gaussianity of the implicit information simplifying the estimator design at the receiver. For instance, a Kalman filter only requires minor adaptions to incorporate implicit information when no transmission event is triggered. The goal of this project is to push the principles of stochastic triggering forward to establish a comprehensive framework of lazy estimation. First, the investigations are concerned with general properties and the design of intelligent trigger decisions to improve the effectiveness and robustness of lazy state estimation. These include model-based and data-driven trigger mechanisms, aperiodic and asynchronous transmission and processing times, as well as the study of unreliable communication links. The results provide the foundations for large-scale lazy estimation with respect to both multisensor systems and high-dimensional state representations. For instance, multiple systems collaboratively monitor a dynamic system and fuse exchanged sensor data and estimates. Such distributed data fusion problems lead to dependent trigger decisions that require self-adapting trigger mechanisms. In particular, the project considers applications in object tracking to evaluate the derived concepts. Lazy estimation shows great potential in the processing of neuromorphic sensor data.
2023 to 2026
Deutsche Forschungsgemeinschaft (DFG)
Using photorealistic visual images to understand the neuronal integration of visual cues for depth and shape in the ventral stream pathways of the primate brain.
The organization of the nervous system for the visual recognition of objects is often thought to be hierarchical. Nerve cells near the top of the hierarchy can typically be activated only by complex and meaningful stimuli, whereas nerve cells low down in the hierarchy are activated by specific distributions of luminance intensities in the image received by the eye. The encoding of information in the high-level stages resembles perception of the object itself, whereas pattern of activity in the earliest stages resembles a simple transformation of the original image., The “hard problem” for visual processing takes place in the critical, intermediate stages, where the transformation from image to object takes place. This project will concern itself with two of these stages in the ventral visual pathways of the macaque cerebral cortex: the fourth visual area (V4) and the posterior inferotemporal (PIT) region. This project will adopt two new technological developments to address the role of these areas in visual processing. First, new designs of microelectrodes will be employed, which allow the recording of up to several hundreds of neurons simultaneously. Second, the project will exploit a new method of creating photorealistic images of recognizable objects, which allows specific manipulation of different sources of information about the size, shape and structure of the viewed object., An important goal is to explore the responses of neurons with full control over the binocular image content. When viewing solid objects, macaque monkeys directly view the object of interest with the most sensitive portion of forward-facing eyes, rotating the two eyes inwards to view near objects, just like humans do. This mode of vision provides information about binocular depth, called stereopsis. My research group has recently studied the responses of V4 and PIT neurons to binocular depth in considerable detail. However, the visual stimuli used for these existing experiments used artificial patterns of dots, which are excellent for isolating the response to binocular depth in a pure form, but do not probe vision with naturalistic stimuli., Prior to the neurophysiological recordings, the macaques will be trained to perform discrimination tasks with the photorealistic images, in which the 3-D shape or configuration of the portrayed object will be subtly altered. This approach will ensure that the animals’ attention is fully engaged with the images and the task, which will allow us to reveal the most sensitive components of the neuronal responses. Full advantage will be taken of the parallel capture of recordings from multiple neurons to test modern theories of information representation in the nervous system.
2025 to 2026
Deutsche Forschungsgemeinschaft (DFG)
Elucidation of microstructure-property relations of novel refractory metal based multi- component alloys for biomedical applications
This project brings together the expertise of the chair "High Temperature Materials" at OVGU with the groups of Prof. H. Stone and Prof. N. Jones at the Department of Materials Science and Metallurgy of the University of Cambridge, UK., The project focuses on materials development and understanding of microstructure-property-relations between the microstructure of multi-component metallic materials and their mechanical properties. Selected materials are examples from the class of biocompatible Ti-Nb-Ta alloys.
2024 to 2026
Deutsche Forschungsgemeinschaft (DFG)
Development and characterization of eutectic V-Si-B alloys with improved specific mechanical properties: role of the new V8SiB4 phase
Vanadium silicide materials represent a potential alternative to currently used high-temperature materials, in particular due to their excellent specific mechanical properties. For example, V-Si-B alloys from the vanadium-rich region of the three-material system consist of a ductile vanadium solid solution (V-Mk) and the two intermetallic phases V, 3, Si and V, 5, SiB, 2, . However, this alloy system, which has been little researched to date, has some surprising similarities to its well-studied neighboring system Mo-Si-B in terms of microstructure. In initial preliminary tests on V-Si-B alloys, significantly better specific compressive strengths were achieved in the temperature range from 600 °C to 900 °C compared to Ni-based alloys. However, the mechanism of phase formation and the correlation of the microstructure-property relationships are still completely unexplored. The primary objective of this project is the development of novel V-Si-B alloys for high temperature applications. The aim is to develop ternary-eutectic alloys. In a series of V-rich binary and ternary test alloys, the phase formation and stability from the melt to the homogenized microstructure will be investigated. In the 2nd funding phase, research will focus on the significance of the newly discovered phase V8SiB4., This text was translated with DeepL
2021 to 2026
Deutsche Forschungsgemeinschaft (DFG)
Mathematical Complexity Reduction (DFG GRK 2297/2)
Im Kontext des vorgeschlagenen Graduiertenkollegs (GK) verstehen wir Komplexität als eine intrinsische Eigenschaft, die einen mathematischen Zugang zu einem Problem auf drei Ebenen erschwert. Diese Ebenen sind eine angemessene mathematische Darstellung eines realen Problems, die Erkenntnis fundamentaler Eigenschaften und Strukturen mathematischer Objekte und das algorithmische Losen einer mathematischen Problemstellung. Wir bezeichnen alle Ansätze, die systematisch auf einer dieser drei Ebenen zu einer zumindest partiellen Verbesserung fuhren, als mathematische Komplexitätsreduktion. Für viele mathematische Fragestellungen sind Approximation und Dimensionsreduktion die wichtigsten Werkzeuge auf dem Weg zu einer vereinfachten Darstellung und Rechenzeitgewinnen. Wir sehen die Komplexitätsreduktion in einem allgemeineren Sinne und werden zusätzlich auch Liftings in höherdimensionale Raume und den Einfluss der Kosten von Datenerhebungen systematisch untersuchen. Unsere Forschungsziele sind die Entwicklung von mathematischer Theorie und Algorithmen sowie die Identifikation relevanter Problemklassen und möglicher Strukturausnutzung im Fokus der oben beschriebenen Komplexitätsreduktion. Unser umfassendes Lehr- und Forschungsprogramm beruht auf geometrischen, algebraischen, stochastischen und analytischen Ansätzen und wird durch effiziente numerische Implementierungen komplementiert. Die Doktorandinnen nehmen an einem maßgeschneiderten Ausbildungsprogramm teil. Dieses enthalt unter anderem Kompaktkurse, ein wöchentliches Seminar und ermutigt zu einer frühzeitigen Integration in die wissenschaftliche Community. Das GK dient als ein Katalysator zur Etablierung dieser erfolgreichen DFG Ausbildungskonzepte an der Fakultät für Mathematik und hilft, die Gleichstellungssituation zu verbessern. Die Komplexitätsreduktion ist ein elementarer Aspekt der wissenschaftlichen Hintergründe der beteiligten Wissenschaftler. Die Kombination von Expertisen unterschiedlicher mathematischer Bereiche gibt dem GK ein Alleinstellungsmerkmal mit großen Chancen für wissenschaftliche Durchbruche. Das GK hat Anknüpfungspunkte an zwei Fakultäten der OVGU, an ein Max-Planck-Institut und an mehrere nationale und internationale Forschungsaktivitäten in verschiedenen wissenschaftlichen Communities. Die Studierenden im GK werden in einer Fülle von mathematischen Methoden und Konzepten ausgebildet und erlangen dadurch die Fähigkeit, herausfordernde Aufgaben zu losen. Wir erwarten weiterhin Erfolge in der Forschung und in der Ausbildung der nächsten Generation führender Wissenschaftler in Akademia und Industrie.
2017 to 2026
Deutsche Forschungsgemeinschaft (DFG)
Mathematical Complexity Reduction
In the context of the proposed RTG we understand complexity as an intrinsic property that makes, it difficult to determine an appropriate mathematical representation of a real world problem, to assess the fundamental structures and properties of mathematical objects, and to algorithmically solve a given mathematical problem. By complexity reduction we refer to all approaches that help to overcome these difficulties in a systematic way and to achieve the aforementioned goals more efficiently., For many mathematical tasks, approximation and dimension reduction are the most important tools to obtain, a simpler representation and computational speedups. We see complexity reduction in a more general way and, will also, e.g., investigate liftings to higher-dimensional spaces and consider the costs of data observation., Our research goals are the development of cross-disciplinary mathematical theory and methods for complexity, reduction and the identification of relevant problem classes and effective exploitation of their structures., We aim at a comprehensive teaching and research program based on geometric, algebraic, stochastic, and, analytic approaches, complemented by efficient numerical and computational implementations. In order to, ensure the success of our doctoral students, they will participate in a tailored structured study program. It will, contain training units in form of compact courses and weekly seminars, and encourage early integration into the, scientific community and networking. We expect that the RTG will also serve as a catalyst for a dissemination, of these successful practices within the Faculty of Mathematics and improve the gender situation., Complexity reduction is a fundamental aspect of the scientific backgrounds of the principal investigators., The combination of expertise from different areas of mathematics gives the RTG a unique profile, with high, chances for scientific breakthroughs. The RTG will be linked to two faculties, a Max Planck Institute, and, several national and international research activities in different scientific communities., The students of the RTG will be trained to become proficient in a breadth of mathematical methods, and, thus be ready to cope with challenging tasks in particular in cross-disciplinary research teams. We expect an, impact both in terms of research successes, and in the education of the next generation of leading scientists in, academia and industry.
2023 to 2026
Deutsche Forschungsgemeinschaft (DFG)
OTU-Deubiquitinylasen
In dem Projekt wird das Ausmaß der suppressiven/regulatorischen Kapazität verschiedener OTUs auf die molekulare Dynamik der klassischen und alternativen NF-kB-Regulation und den apoptotischen Zelltod bei einer, H. pylori, -Infektion untersucht. Einschichtige 2D-Magenorganoide ermöglichen es, die funktionelle Spezifität der OTUs in primären Zellen zu erforschen. Mittels CRISPR/Cas9-Technologie werden eine Reihe von Knock-out-Organoide für bestimmte OTUs generiert, sowie ein DUB-spezifischer CRISPR/Cas9-Screen durchgeführt. Die Expression von NF-kB-regulierenden OTUs wird zudem in menschlichen Magenbiopsien untersucht, um die veränderte Expression mit dem Krankheitsstatus zu korrelieren. Die Entschlüsselung der Rolle von DUB-Enzymen bei der NF-kB Kontrolle, dem Zellüberleben und der Magenpathologie bei einer, H. pylori, -Infektion wäre ein bedeutender Fortschritt zum Verständnis der Entstehung menschlicher Magenerkrankungen.
2023 to 2026
Deutsche Forschungsgemeinschaft (DFG)
Project 8: Intimate interaction of monocytes/macrophages with resident kidney cells in maladaptive tubular damage
Tubular cells are metabolically highly active and responsive to "external stimuli” by direct contact to urine outflow. Activated tubular cells release mediators affecting local and recruited immune cells, aiming to maintain a balanced milieu. However, if errant, these processes lead to maladaptive responses involving tubular cells, pericytes, and endothelial cells resulting in renal fibrosis and vascular rarefication. Our preliminary data demonstrate that cold shock proteins (e.g. YB-1) largely control monocytic cell recruitment to activated tubular cells. The mechanisms through which YB-1 regulates the tubular cell phenotype, e.g. its impact on gene expression and PTMs, remain unknown. Furthermore, the mechanistic relevance of YB-1 for monocyte recruitment, and phenotypic changes, pericyte-phenotype, and peri-tubular capillaries remains unclear. We hypothesize that YB-1 regulates the tubular secretome and thus the peritubular micromilieu, modulating the phenotype of adjacent cells and the recruitment of monocytes in chronic kidney disease. We speculate that YB-1 activity is persistently posttranslationally modulated (e.g. acetylation, ubiquitination). To address these questions we will analyze chronic kidney injury models in mice lacking YB-1 or the YB-1 target Notch3 specifically in tubular cells (cooperation with Project 5). YB-1 dependent gene expression (expression profiling and ChIP analyses) and the tubular secretome (BIOPLEX) will be determined in cooperation with Project 9. The regulation of YB-1 stability and function through post-translational modifications will be analyzed in cooperation with Project 1, Project 2, and Project 7. Structure-function in vitro analyses will be conducted to delineate the mechanistic relevance of these post-translational modifications. Kinetic analyses will enable us to determine the relevance of YB-1 modifications for disease perpetuation. To this end ex vivo approaches with co-culture systems will be conducted (including primary tubular cells from wt and genetically modified mice). The relevance of YB-1 in tubular cells or monocytes for peritubular capillary rarefication will be analyzed in cooperation with Project 4 using state of the art in vivo imaging. In a translational approach human tissue samples will be analyzed to validate the findings.
2022 to 2026
Deutsche Forschungsgemeinschaft (DFG)
Zugehörigkeit. Die Geschichte der Adoption von Kindern (1945/9-2000)
Die Frage nach der Zugehörigkeit zu einer Familie, zu einer ethnischen oder religiösen Gruppe oder zu einem Staat ist immer brisant. Der Fokus der derzeitigen Flüchtlingspolitik und die weltweite Zunahme von isolationistischen, nationalistischen und identitären Parteien zeugen davon, wie aufgeheizt dieses Thema sein kann., Solche Debatten über Zugehörigkeit, Herkunft und Identität spielten eine wesentliche Rolle in der Geschichte der Adoption von Kindern. Hier wurden politische Vorgaben und gesellschaftliche Diskussionen mit psychologischen und medizinischen Annahmen über das gesunde Aufwachsen und die Herstellung familiärer Bindung und Liebe verbunden und in Praktiken übersetzt, die darüber entschieden, welches Kind in welche Familie kam und wie dieses Kind zum „eigenen“ Kind wurde. Zugleich ging es kontinuierlich um Grenzziehungen und Ausschluss: Wer konnte oder durfte kein Kind aufziehen? Wer sollte nicht adoptiert werden? Schließlich bewegte sich die Adoption von Kindern in einem immer wieder neu vermessenen Spannungsfeld: zwischen humanitären Interventionen zum Wohlergehen des Kindes, normativen Vorstellungen über Asozialität und Erziehungsunfähigkeit, den Wünschen elternloser Paare nach einem Kind sowie – in der Bundesrepublik – der Logik eines zunehmend internationalen Adoptionsmarktes., Dieses Projekt stellt die erste übergreifende Erforschung der Geschichte der Adoption von Kindern in der DDR und der Bundesrepublik bis in die Transformationszeit der 1990er Jahre dar. Es stützt sich auf ein innovatives methodisches Design, das verschiedene Quellengenres und -zugänge miteinander kombiniert und u.a. Verwaltungsakten, Dokumente von Adoptionsagenturen, Ratgeber, Kinderliteratur, wissenschaftliche Aufsätze aus Psychologie, Psychiatrie und Sozialarbeit sowie Ego-Dokumenten konsultiert. Ein Teil der Studie basiert auf lebensgeschichtlichen Interviews.
2023 to 2026
Deutsche Forschungsgemeinschaft (DFG)
An integrated semiconductor platform for the implementation and study of higher-order exceptional points
The transfer of fundamental concepts of open wave or quantum systems to highly integrated solid-state devices is of utmost importance both for a deeper understanding of the underlying physics and for new technologies. In recent years, non-Hermitian systems have come into focus, including those that exhibit parity time-reversal symmetry. The main reason for the increasing interest are the so-called exceptional points (EPs) in parameter space, i.e. exotic degeneracies where two or more energy eigenvalues and the corresponding eigenstates coincide. Besides a number of interesting fundamental aspects, these degeneracies hold great potential for highly sensitive sensors. Potentially even more so when moving from second-order EPs to nth-order EPs, where n eigenvalues and eigenstates coincide. This interdisciplinary research project is located at the interface between experimental solid-state optics and theoretical non-Hermitian photonics. The Magdeburg group will provide the foundations and theoretical framework by using coupled mode theory and numerical simulations to obtain suitable parameter sets for EPs (higher order) and to simulate and evaluate the potential for novel sensors. The Würzburg group will use its expertise in semiconductor epitaxy and device fabrication to realize tailor-made EP devices based on scalable group III-V materials. The fabrication and optimization of the devices will be closely linked to the numerical simulations and efficiently performed in an iterative manner. The aim of this project is to develop a robust and versatile integrated semiconductor platform that enables the concept of EPs to be combined with the mechanism for generating so-called exceptional surfaces in parameter space and the resulting robust EPs. Using semi-automated device characterization, we will map the parameter space and realize second- and third-order EPs in ring laser devices coupled with suitable bus waveguides. We will use advanced spectroscopic techniques to characterize the properties of the fabricated devices and demonstrate the desired nth root scaling of the system response to perturbations. Using an artificial scattering body, which will be both lithographically defined and mobile, we will investigate the sensing capabilities of these scalable devices. In a later phase of the project, we will turn to mapping the energy surfaces in the vicinity of the EPs. This will give us valuable insights into the not yet well understood topology around higher order EPs, which will link our research to the exciting new field of topological photonics., This text was translated with DeepL
2021 to 2025
Deutsche Forschungsgemeinschaft (DFG)
ACCESS: Access to social rights in Germany, France and Europe
Our project aims to investigate the impact of Europeanization on the conditions of access to social rights and benefits in Germany and France - from Europeanization that shifts the repertoires of compensation for social inequalities to a repertoire of struggle against discrimination. The concept of social citizenship, by which we mean (i) a narrative of social cohesion, (ii) a relationship between individual participation and social protection and status, and (iii) a territorially constituted relationship, offers an innovative analytical framework for this. France and Germany from the 1950s until today have been chosen as comparative contexts, whose contrasting traditions of social citizenship enter into different entanglements with Europeanization. In France, this is based on an abstract concept of equality and a universally understood social integration that differentiates according to social status and thus allows concrete objectives to be set for public action. In Germany, on the other hand, it is based on belonging to a cultural community and is generally delegated to intermediary bodies, allowing for more disparities thanks to decentralized organization. We examine social inequalities and discrimination in access to social rights with regard to women and migrants. These two population groups have been historically marginalized in the labour market and in the context of social security in both countries. Our project has three interrelated objectives. 1. On the basis of available literature, we develop an overview of (i) the forms of problematization of access to social rights, (ii) the legal codifications and (iii) the policy instruments of public action regarding social inequalities and discrimination based on gender, migration or ethnicity in France and Germany. 2. take stock of European provisions and regulations on access to social rights and benefits on the basis of administrative and legal documents. 3. we examine the effects of Europeanization processes on the definition and regulation of social rights and benefits in both countries, particularly with regard to the selected population groups. We focus on the period after 2000, after the adoption of the European Anti-Discrimination Directive. The project aims to identify the changes, adaptations and difficulties in legal codification and in the development of policy instruments on the basis of which inequalities are compensated and discrimination is combated. We work on the basis of symmetrically designed case studies with a thematic focus on access to basic social security and vocational training measures., This text was translated with DeepL
2022 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Rise, Fall, or Transformation of the Experience Society
Neuere Zeitdiagnosen zeichnen ein eher düsteres Bild der gesellschaftlichen Verhältnisse, so bspw. die "Flucht nach vorn: Die Erfolgskultur der Gegenwart" (Neckel 2008), die "Gesellschaft der Angst" (Bude 2014) oder die "Abstiegsgesellschaft" (Nachtwey 2016). Der Kontrast zu den Gesellschaftsdiagnosen vor der Jahrtausendwende ist beachtlich. Paradigmatisch für den Optimismus der 1980er und 1990er Jahre war die These der Erlebnisgesellschaft von Gerhard Schulze (1992): Angesichts des materiellen Überflus-ses für breite Schichten habe sich die Modernisierung von außen nach innen gewendet, weg von einer Orientierung auf Status und materiellen Erfolg hin zum fast spielerischen "Projekt des schönen Lebens". Infolge dessen seien auch soziale Ungleichheiten im Alltag der Menschen weitgehend irrelevant geworden, was Schulze als subjektive Entvertikalisierung bezeichnet. Konfrontiert mit den jüngsten Gegenwartsdiagnosen und der dort thematisierten steigenden ökonomischen Ungleichheit und Unsicherheit stellt sich daher die spannende Frage: Ist die Erlebnisgesellschaft schon wieder Geschichte? Oder leben wir immer noch - und vielleicht sogar mehr denn je - in einer Erlebnisgesellschaft? Oder hat sich die Gesellschaft angesichts neuer sozio-ökologischer Krisen und Herausforderungen (Stichworte: Nachhaltigkeit und Postwachstum) zuletzt in eine ganz andere Richtung entwickelt? In diesem Spannungsfeld der Zeitdiagnosen soll das beantragte Projekt eine Positionsbestimmung der deutschen Gesellschaft vor dem Hintergrund der Theorie der Erlebnisgesellschaft vornehmen, die im Jahr 2022 ihr 30-jähriges Jubiläum feiert. Wir erforschen, ob der Wandel zur Erlebnisgesellschaft trotz fragiler gewordener Rahmenbedingungen immer noch intakt ist (Szenario "Aufstieg der Erlebnisgesellschaft") oder sich wieder umgekehrt hat (Szenario "Fall der Erlebnisgesellschaft"). Dabei ist das Projekt auch offen für die Möglichkeit, dass die Gesellschaft mit dem neuen existenziellen Problem des "nachhaltigen Lebens" eine neue Entwicklungsrichtung eingeschlagen hat (Szenario "Transformation der Erlebnisgesellschaft").Um diese Positionsbestimmung vornehmen zu können, stellt das Projekt zwei Grundannahmen der Schulze’schen Theorie in den Mittelpunkt: die der innengerichteten Modernisierung in Richtung Erlebnisorientierung sowie die der subjektiven Entvertikalisierung der Gesellschaft. Diese Grundannahmen überprüfen wir bevölkerungsrepräsentativ im Zeitverlauf (ab ca. 1980 bis heute) für Deutschland und zusätzlich mit aktuellen Querschnittsdaten im internationalen - v. a. europäischen - Ländervergleich (ab ca. 2000 bis heute). Das Forschungsvorhaben ist in großen Teilen sekundäranalytisch angelegt, nur für das Thema der Transformation planen wir eine explorative Primärdatenerhebung. Unser Projekt ist nicht nur zeitdiagnostisch hochrelevant, sondern stellt, von vereinzelten Arbeiten abgesehen, seit langem ein soziologisches Forschungsdesiderat dar., https://gepris.dfg.de/gepris/projekt/465345673
2023 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Autonomous control of a process chain for CO2 carbonization using mining waste
The aim of the project is to develop an autonomous and self-learning process chain to turn CO2, and mining waste via carbonate formation to produce a poorly soluble solid. In four steps, 1. calcium and magnesium ions are dissolved out of the mineral, 2. the resulting suspension is filtered, by 3. in the aqueous solution in a pH change process with the addition of CO2, to cause the targeted formation of calcium carbonate and magnesium carbonate and then 4. to centrifuge off the solids., The process should also run autonomously in the event of changes to the initial and boundary conditions., find and adjust the optimum conditions for the targeted production of solids, in order to achieve the desired product properties and consume as little energy as possible., The project is embedded in the SPP2364 and is being worked on together with colleagues at KIT Karlsruhe and TU Kaiserslautern., This text was translated with DeepL
2022 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Autonomous control of a process chain for carbonate formation from CO2 using mining waste
A process chain, starting with the extraction of calcium and magnesium from mining waste with acidic solutions, the filtration of the suspension through to the final processing of the solution in a pH change process using CO2 under higher pressure and the addition of base for the targeted production of calcium and magnesium carbonate as poorly soluble precipitation products, is to be optimally controlled and autonomously regulated under changing conditions of the starting materials and process environment. In cooperation with the TU Kaiserslautern (control) and the KIT (triggering and filtration), the complex process is to be set up, investigated in detail and optimized in a miniplant as a pilot plant in Magdeburg as part of the SPP2364., This text was translated with DeepL
2023 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Autonome Strukturbildung bei der Wirbelschichtsprühagglomerationen (SPP2364)
Im Rahmen des vorliegenden Projektes werden dynamische Modelle und Methoden der modellgestützten Prozessführung für die Partikelbildung durch Wirbelschichtsprühagglomerationen entwickelt und experimentell erprobt. Zentrale Zielsetzung ist die gezielte Einstellung gewünschter Partikelstrukturen mittels modellgestützter Prozessführung. Das Projekt ist im DFG Schwerpunktprogramm SPP 2364 Autonome Prozesse der Partikeltechnik angesiedelt und wird in Kooperation mit der AG Tsotsas von der Otto-von-Guericke-Universität und der AG Bück von der Friderich Alexander Universität Erlangen Nürnberg durchgeführt.
2023 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Direct numerical simulations and data-driven analysis of ignition and combustion in realistic pre-chamber/ engine systems with NH3/H2 blend fuel
To facilitate carbon-free and low emission combustion in practical engine systems, this project investigates the transient ignition and turbulent combustion process in a realistic pre-chamber/engine geometry with NH3/H2 blend fuel. Direct numerical simulations (DNS) are carried out for this system with exascale computation on Supercomputers, generating a vast amount of high-fidelity data. Machine learning techniques are applied to accelerate the chemical kinetic computation in DNS. The realistic geometry is represented by the immersed boundary method. Data-driven analysis is done to investigate in detail the ignition characteristics and the multi-scale features of the turbulent flames. NOx emissions are also investigated. A better understanding of the practical pre-chamber/engine system using NH3/H2 fuel should be finally obtained, which would be useful for both fundamental academic research and practical applications.
2020 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Effects of hippocampal vascularization patterns on the neural resources of MTL neurocognitive circuits
The hippocampus and adjacent entorhinal cortex (EC) form a neural circuit within the medial temporal lobe (MTL) that is crucial for episodic memory formation. Integrity of this circuit is massively affected by age-related degeneration, partly due to pathology (e.g. tau, microinfarcts), partly due to environmental factors. Interestingly, the pattern of hippocampal vascularization varies among individuals, that is, there are individuals with a single supply, and there are individuals with a double supply., We recently found out that the individual vascularization profile interacts with verbal memory and global cognition: participants with a double supply had higher scores in the California Verbal Learning Test (CVLTII). What is not clear so far is which neuronal mechanisms underlie this effect. How does the individual vascularization profile affect cognitive aging? How does a double supply contribute to cognitive resource, and does it interact with training success?, These are the key questions addressed in this project within the CRC 1436. Here, we use the beneficial effect of a double hippocampal blood supply as model to understand the neuronal basis of cognitive resources in younger and older adults. By using ultra-high resolution functional and structural imaging at 7 Tesla together with advanced modeling techniques, we will investigate how the fine-grained hippocampal vascular supply affects age-related MTL pathology, MTL integrity, and MTL myeloarchitecture (neural resources), and how this mediates subregion-specific memory function (cognition). Finally, we will test how the effect of cognitive interventions on MTL function is modified by the hippocampal vascularization patterns.
2023 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Exzellenzcluster SE²A: C3.1 - Funtional 3D design and experimental validation of shape adaptive fan blading
In the first phase of SE2A, Project C3.1 explored the potential of morphing high pressure compressor blade designs based on titanium alloys and composite actuators made of active materials. To further expand and enhance the morphing capabilities of engine blades, the subsequent project focuses on state-of-the-art UHBR fan blading. By applying 3D-design measures, such as sweep and dihedral as well as alternative materials and advanced actuation concepts, this research aims to boost sustainability of future aircraft engine concepts, independent of the respective propulsion architecture. In the design of UHBR fan blading, the focus especially lies on a composite blade body to increasingly tailor the achievable morphing magnitudes and shapes. Through structural morphing simulations and aerodynamic performance evaluations a suitable blade prototype is identified and manufactured. The composite blade prototype and its morphing behavior is then experimentally evaluated under realistic but static load conditions as a preparation for a future application in a rotating environment.
2022 to 2025
Deutsche Forschungsgemeinschaft (DFG)
FOR 5228 Syntophagy - Teilprojekt RP9: NPY-mediated autophagy and the adaptation of hippocampal circuits to stress
The mammalian brain has an enormous capacity for structural and functional plasticity adjusting behavior to an ever-changing environment. This ability requires highly coordinated signaling, synchronized (de-)construction of synapses and adjustment of proteostasis in functional neuronal circuits. Maladaptive changes, arising from early-life adverse experiences, traumatic stress or neurodegenerative processes, can lead to neuropsychiatric conditions such as post-traumatic stress disorder (PTSD), depression or dementia., Neuropeptide Y (NPY) is well established as an anxiolytic and stress-reducing factor and NPY transmission in the dorsal dentate gyrus (DG) has been demonstrated by us and others to control fear memory salience and traumatic stress resilience. Moreover, recent evidence suggests that NPY might play a key role in synaptic preoteostasis, by regulating neuronal autophagy both in vertebrates and invertebrates and that this might explain its capacity to modulate long-term cellular changes in neural circuitry. In this project we will therefore study the role of NPY-induced autophagy in a local circuit relevant for stress adaptation and emotional and cognitive information processing., Specifically, in the DG-to-cornu ammonis (CA)3 system we will address mechanisms of behavioral induced autophagy in DG mossy fibers (MF) and their associated local NPY-secreting interneurons. The role of postsynaptic NPY-Y1 and pre-synaptic/autoregulatory NPY-Y2 receptors as well as intracellular and local circuitry signals will be examined. In addition, we will investigate the behavioral consequences of disturbed NPY-induced autophagy in these cells and ultimately aim to identify molecular and cellular processes that mediate NPY-induced adaptive changes and stress resilience. Our project intends to bridge a cellular and molecular analysis of autophagy to its involvement in adaptive cognitive and emotional brain function and is thereby interwoven with various other research projects of Syntophagy.
2022 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Gradual Functional Changes
With the advance of computer facilities and data storage warehouses, more and more data are being recorded continuously during a time, period or intermittently at plethora of discrete time points. These are, both examples of functional data, which furthermore embrace random, fields or manifolds. Our attention is devoted to stochastic functions, predominantly represented by random curves or surfaces, where, every function is considered as a single observation. These, observations are naturally ordered with respect to time and possibly, changing over time. The interest is not in an individual change within each curve, but in a change of the pattern across the sequence of, curves. Almost all existing change detection methods are designed to, discover abrupt breaks. Little attention has been paid to smooth, structural changes, which may be more realistic in practice. With the, vantage of functional analysis and empirical processes, we can, deploy advanced statistical tools like bootstrap or lasso to diagnose, the gradual change of functional form in the time series of random, curves.
2022 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Combination of a CD19 antibody of IgA isotype and CD47 inhibition for the treatment of BCP-ALL
In this project, we hypothesize that the combination of a CD19-IgA antibody with blockade of CD47 will result in improved recruitment of myeloid effector cells such as granulocytes and macrophages, and therefore better preclinical efficacy, in vivo, . The results of the proposed experiments will constitute the basis for the translation of clinical protocols combining anti-CD19-IgA constructs with CD47 blockade into early phase clinical trials in adult and pediatric ALL. Such strategies may be particularly relevant in subgroups with an urgent need for therapy optimization, such as, KMT2A, -rearranged disease at all ages.
2023 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Nonlinear capillary systems with surfactant-laden interfaces
Surface-active substances adsorbed at fluid interfaces are ubiquitous and understanding their subtle but often dominant influence is therefore of central importance for a variety of technical applications and natural phenomena. Theoretical studies on the physico-chemical hydrodynamics of capillary systems with surfactants have so far been mainly limited to simple surfactants, cases without topology changes and small Reynolds numbers. As a result, there is no comprehensive understanding of the influence of surface viscosity and inertia, which is important in technical applications from bioengineering to manufacturing, in capillary systems including changes in interface topology. This project investigates the fundamental physical mechanisms associated with the nonlinear behavior of surfactant-laden capillary systems, focusing on the subtle but important influence of surface viscosity and the development of capillary instabilities and fragmentation., This will contribute to a more detailed understanding of the interaction of surface viscosity and inertia with surface-tension dominated interfacial motion and its effects on topology changes in capillary systems over a wide range of length scales. To study these flows, we will develop new numerical methods for simulating interfacial flows with insoluble surfactants and surface viscosity in the domain of continuum mechanics, which, integrated with state-of-the-art numerical simulation tools, will provide a rational computational framework for the accurate modeling of surface-active substances., This text was translated with DeepL
2023 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Pro-Active Routing for Emergency Testing in Pandemics
A pandemic can immobilize municipalities within a short amount of time. The key is to discover and avoid spreading of infection clusters through fast and effective testing. An innovative idea implemented during the COVID-19 pandemic in metropolitan areas such as Vienna, Austria, is the employment of a workforce of mobile testers. This project deals with the operational management of such mobile testers and the resulting impact on the spread of a disease using COVID-19 as an example.Based on state-of-the-art multi-agent simulation models, we will generate and analyze data on the tem-poral and spatial spreading (descriptive analytics). With methods of predictive analytics, we will aggregate the data to a detailed information model with a particular focus on modelling correlation for testing de-mand. Using this, we will model and solve the dynamic tester routing with infection hot spots and correla-tion demand problem (TRISC) using methods of prescriptive analytics, esp. reinforcement learning. The obtained policies will be evaluated by the multi-agent simulation again.Hypotheses / research questions / objectivesThe following core research questions will be investigated: (1) How can data of the spread of highly infec-tious diseases like COVID-19 be analyzed and modeled for the purpose of dynamic workforce control? (2) How can we achieve an effective dynamic control of the workforce in reaction and in anticipation of the complex disease information? (3) When is anticipatory dynamic workforce control effective in containing the spread of pandemics?The problem at hand shows new and severe complexity in the information model of the demand (test requests) and in the decision model for the operational control. Deriving the demand information model (via predictive analytics) is complex because it must capture the spatial-temporal correlation of demand. The decision model for the problem is a novel stochastic and dynamic vehicle routing problem. Determin-ing high-quality decisions that integrate the information model (via prescriptive analytics) is therefore additionally challenging. The evaluation by an established agent-based simulation is particularly excep-tional for this research field.The project will be conducted by Jan Fabian Ehmke (JE, Universität Wien), Marlin Ulmer (MU, Technische Universität Braunschweig), and Niki Popper (NP, Technische Universität Wien). JE will serve as coordina-tor and is responsible for tasks of predictive analytics. MU leads the project part on prescriptive analytics for dynamic vehicle routing. NP will contribute with an agent-based simulation that supports the creation of the predictive information model and the evaluation of dynamic and stochastic disease sampling. This will provide unique opportunities to extend current methods including their evaluation in the urgent ap-plication of disease routing.
2023 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Dynamische Eigenschaften anisotroper magnetischer Fluide
Weiche multifunktionale Materialien eröffnen neue Wege für das Design intelligenter Bauelemente, die auf verschiedene Stimuli, wie elektrische und magnetische Felder, mechanische Deformation und chemische Reize reagieren. Magnetische Nanokomposite, die auf Flüssigkristallen basieren, sind sehr vielversprechende Systeme, da die Flüssigkristallstruktur die magnetische Ordnung stabilisieren kann. Jüngste Demonstrationen der spontanen ferromagnetischen Ordnung im Flüssigkristallzustand gestatteten das Design neuer optischer Materialien, die sehr empfindlich auf magnetische Felder reagieren. Unser Projekt setzt die Verfolgung der Ziele der ersten Förderperiode fort mit dem Fokus, die Dynamik und Selbstorganisationsmechanismen in anisotropen Flüssigkeiten mit magnetischer Ordnung zu verstehen. Der neue Antrag baut auf den Erfolgen und den neuen Erkenntnissen beim Studium der Dynamik von Dispersionen magnetischer Nanoplättchen auf, die in der ersten Förderperiode unter Anwendung der AC-Suszeptometrie sowie mechanischen, magnetischen und optischen Untersuchungen im rotierenden Magnetfeld gewonnen wurden. In der neuen Förderperiode werden wir die Untersuchungen an Nanoplättchen enthaltenden magnetischen Flüssigkeiten fortsetzen und die Rolle von Matrix-vermittelten Wechselwirkungen und der Wirkung von räumlichen Beschränkungen auf die Selbstorganisation untersuchen sowie den Charakter von Matrix-vermittelten Kopplungen studieren sowie rheologische Untersuchungen durchführen. Insbesondere werden wir den Einfluss von Grenzflächenverankerungen auf die Struktur und Dynamik von räumlich eingeschränkten Ferronematen und ferromagnetischen Nematen, wie Mikrotröpfchen, erforschen. Die Verwendung von Mischungen von thermotropen Nematen mit Nanoplättchen wird uns gestatten, aktive magnetische Emulsionen zu produzieren und untersuchen, in denen Mikrotröpfchen in der Anwesenheit von Tensiden mit Konzentrationen oberhalb der kritischen mizellaren Konzentration angetrieben werden. Die Anwendung von vor Kurzem entdeckten ferroelektrischen Nematen als Matrix für die ferromagnetischen Nanoplättchen wird uns die Präparation multiferroischer Materialien gestatten, die die Eigenschaften von flüssigen Ferroelektrika und Ferromagneten kombinieren. Der eingereichte Projektantrag liefert eine einzigartige Möglichkeit, unser Verständnis von flüssigen ferromagnetischen Materialien zu erweitern, was sowohl für die Grundlagenforschung als auch für technologische Anwendungen essentiell ist.
2022 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Schubspannungen an festen und elastischen Oberflächen durch Ultraschallkavitation
Interest in bubble-induced shear stress is motivated by a variety of technological, chemical and biomedical applications, where this effect is used. Ultrasonic cleaning, micromixing of liquids, intensification of chemical reactions and heat-exchange processes are examples of such applications in the engineering field. In the biomedical field, ultrasound-mediated drug delivery, ultrasound-induced blood-brain barrier opening, bacteria lysis or disinfection are examples of bubble-mediated bioeffects. During decades research works mainly focused on the violent mechanisms resulting from bubble collapses, including shockwave emissions and the generation of microjets. Recent sensitive applications have demonstrated that purely oscillating bubbles may also produce significant mechanical effects on rigid or elastic surfaces through the generation of shear stress. This shear stress results from the liquid flows created in vicinity of the oscillating bubbles. Up to now, the influence and modification of surfaces by bubble-induced shear stress has been mostly investigated qualitatively. The quantitative measurement of shear stress, as well as the potential control of the force exerted by an oscillating or a collapsing bubble near rigid and elastic surfaces, remain challenging., The CaviStress project consequently focuses on the quantification of bubble-induced shear stress, through theoretical, numerical and experimental investigations of the interplay between a cavitation bubble and an in-vicinity interface. The main objective of the project is the control and optimization of wall shear stresses induced by cavitating bubbles, and its application in two different fields: (i) the particle removal on solid surfaces, and (ii) the molecular uptake into biological cells., We investigate theoretically and numerically the shear stress induced by oscillating and collapsing bubbles both in bulk fluid and near rigid or elastic walls. The bubble-induced liquid flows are derived theoretically. The fundamental findings are compared to controlled experiments, from the single bubble case to a realistic multi-bubble streamer where turbulence and mixing occur. Once the liquid flows are characterized, the shear stress is theoretically and numerically quantified. Experimental investigation of the impact of shear stress on rigid walls focuses on its scaling dependence, thus allowing to identify parameter ranges where damage-free cleaning of sensible surfaces is feasible. In parallel, experimental studies of the shear stress on elastic walls focus on the internalization of molecules into biological cells by evaluating the cell poration efficiency from well controlled oscillating or collapsing bubbles. The expected quantification and differentiation of the bubble-induced mechanical effects paves the path to improved ultrasound-based procedures for cleaning and drug delivery through bubbles.
2022 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Autonomous structure formation rocesses in spray fluidized bed agglomeration
Recent progress in spray fluidized bed agglomeration enables to model kinetics and particle formation during the process. With minimal amount of empirical information on the influence of operating conditions on fractal dimension, agglomerates can be produced in silico, even printed out in 3D. Such advanced technologies shall be applied to the continuously operated process, in combination with new methods for inline monitoring and automatic control. The goal is to automatic control. The goal is to autonomously run the process towards desired agglomerate structures and structure-dependent end-user properties.
2020 to 2025
Deutsche Forschungsgemeinschaft (DFG) // Land Sachsen-Anhalt
Planning, Navigation and Monitoring Device for CT-guided Interventions (Großgeräteantrag)
In this project within the framework of the DFG major research instrumentation programme, a planning/navigation device is to be interfaced with a computer tomograph so that it can act as a central information system. In addition, algorithms are to be developed to facilitate CT-supported interventions in cooperation with several research groups on the STIMULATE research campus. These include, for example, new deep-learning-based segmentation procedures and path optimization algorithms to support multi-applicator planning or new CT image reconstruction procedures to reduce artifacts while saving radiation dose.
2022 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Continuum model with gas-liquid interfacial area for evaporation in porous media
The drying kinetics of porous materials is influenced by the liquid-gas interfaces (menisci) developed and displaced in the course of drying. This project seeks to incorporate the liquid-gas interfacial area into continuum models of drying by combination of state of the art of pore network modeling, pore network simulations, and new experiments.
2021 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Research Group 5228 "Syntophagy” Project RP9: NPY-mediated autophagy and the adaptation of hippocampal circuits to stress
Recent findings suggest that neuropeptide Y (NPY) can regulate autophagy in neurons from both vertebrate and invertebrate animals. This ability could explain how NPY can induce long-term cellular changes in neural circuits. In addition to the Syntophagy project RP8, which investigates the non-cell-autonomous metaplastic effects of NPY, we focus here on the role of NPY-induced autophagy in a local circuit for stress adaptation and for processing emotional and cognitive information in the dentate gyrus (DG) -to- Cornu-Ammonis (CA) 3 system. We will investigate mechanisms of behavior-induced autophagy in DG moss fibers (MF) and the associated local NPY-secreting interneurons. We will also determine the behavioral effects of impaired NPY-induced autophagy in these cells and ultimately identify molecular substrates that mediate these adaptive changes. In our project we intend, in close collaboration with various other Syntophagy projects, to combine a cellular and molecular analysis of stress-induced autophagy with the elucidation of its role in adaptive cognitive and emotional functions.
2021 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Principal component analysis for multivariate extremes
The aim of this project is to explore extensions of the classical dimension reduction technique of principal component analysis (PCA) to the setting of multivariate extreme value theory. In this setting, a challenging aspects is that in the natural modelling framework of non-negative max-stable vectors the orthogonal decomposition in the Euclidean space standing behind the PCA for normally distributed data is no longer applicable. Instead, the max-times-algebra lends itself to a more suitable framework for a decomposition of the dependence structure. This project explores how an optimal projection of a max-stable vector into a lower dimensional space can be implemented efficiently, justified theoretically and how we can interpret the result for specific classes of models
2022 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Modellierung und Quantifizierung von Effektgrößen für faktorielle Daten in der Überlebenszeitanalyse -Teil II
Ziel dieses Vorhabens ist es, den erfolgreichen Weg der ersten Projektphase fortzusetzen und biostatistische Verfahren zur Effektquantifzierung in komplexen Designs mit 'time-to-event' Endpunkten (weiter) zu entwickeln. Diese sind motiviert durch interdisziplinäre Kooperationen der PIs mit medizinischen Kollegen von nationalen Universitätskliniken sowie auftretenden Problemen mit existierenden Verfahren aus der Literatur. Ein besonderer Fokus liegt deshalb auf gut interpretierbaren Estimands wie dem RMST (restricted mean survival time) sowie Situationen mit nichtproportionalen Hazards und/oder konkurrierenden Risiken wie sie bspw. in der Onkologie (insbesondere bei neuartigen Immuntherapien), bei bestimmten Autoimmunerkrankungen (wie multipler Sklerose) oder chronischen Atemwegserkrankungen (wie Asthma im Kindesalter) auftreten können., Um für solche Settings vertrauensvolle biostatistische Inferenzmethoden (Punktschätzer, Konfidenzintervalle und -bereiche sowie Tests) zu entwickeln, werden auf methodischer Ebene bspw. permutations- und bootstrapbasierte Verfahren mit modernen Techniken der nichtparametrischen Statistik, des multiplen Testens und des maschinellen Lernens kombiniert. In ausgiebigen Simulationsstudien, gemeinsamen Analysen mit interdisziplinären Kooperationspartnern /innen sowie rekonstruierten Daten von aktuellen Studien wird die Methodik hinsichtlich Praktikabilität und Effizienz optimiert. Im Anschluss werden die Verfahren in R-Pakten und nutzerfreundlichen shiny-Apps einer breiten Maße von Biometrikern/innen zur flexiblen Analyse von komplexen 'time-to-event'-Daten zur Verfügung gestellt. Ausführliche Guidelines sowie eingängliche Zeitschriften-Artikel ermöglichen den einfachen und unmittelbaren Zugang zur Software.
2022 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Optimization of the operation of fluidized bed processes using machine learning
Fluidized bed processes are the basis for many applications where rapid mixing, heat and mass transfer between gas and solid particles is required. Their performance is largely dependent on bubble dynamics: rising bubbles drive solids circulation and significantly improve gas-solid contact, enhancing mixing, reaction and transport properties. To date, almost all fluidized beds have been operated with a uniform gas flow. However, current scientific work shows that operating a fluidized bed with an alternating gas flow (e.g. sinusoidal, gas fluidization velocity) leads to different bubble patterns and dynamics. The aim of this project is to analyze the bubbles in a fluidized bed by applying artificial intelligence methods., (AI) such as evolutionary algorithms and genetic programming. We will use our lab-scale fluidized bed with camera system and computational models in Euler-Euler and Euler-Lagrange method to capture the dynamics of bubbles in the fluidized bed while varying the fluidized gas velocity spatially and temporally. Initially, these results are used to find the optimal inflow pattern for given objective functions., The challenge for the AI algorithms is to find the right balance between the time-consuming experimental data and the simulation data to efficiently provide the required fluidization velocity profile. Furthermore, we will consider several conflicting objective functions using multi-objective optimization algorithms. Secondly, the AI algorithms will be used to obtain optimal bubble size and dynamics by controlling the velocity profile. The ability to control the behavior of the bubbles in a fluidized bed enables the improvement of product quality, efficiency and selectivity of the process, among others., This text was translated with DeepL
2022 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Oxide dispersion strengthened and oxidation resistant Vanadium alloys
The, complex oxidation behavior, of vanadium is the reason why vanadium-based alloys cannot be considered for use at high temperatures, despite their high strength and low density. In addition, vanadate changes very easily between different oxidation states and thus extremely accelerates the high-temperature corrosion of Ni, Co or Fe-based materials, especially when it is present in molten form. This also rules out the use of current vanadium alloys in the environment of these materials., In order to make vanadium alloys usable at high temperatures, a completely new and, innovative approach to oxidation protection, with, simultaneous, oxide particle reinforcement, is therefore to be pursued: The development of Mg- and Ca-containing oxide particles for the production of oxidation-resistant ODS vanadium-silicon alloys. The ODS particles introduced in sufficient concentration should prevent liquid phase formation at high temperatures. At the same time, the ODS particles are expected to have a strength-enhancing effect, which is to be quantified in the potential application area of such alloys from room temperature to 1050 °C., The project aims to clarify (1) up to what volume fraction of MgO, CaO or magnesium orthosilicate particles homogeneous microstructures can be achieved in vanadium materials, (2) how high the necessary MgO, CaO or magnesium orthosilicate concentration is in order to prevent liquid phase formation or to provoke a self-protecting mechanism, (3) how great the strength-enhancing effect of the addition of oxide dispersoids is and how the ODS particles affect creep formation. to provoke a self-protecting mechanism, (3) how great the strength-enhancing effect is through the addition of oxide dispersoids and how the ODS particles affect the creep behavior of vanadium alloys., This text was translated with DeepL
2023 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Strategies for the dynamic adaptation of discretization based on higher-order transition elements for the analysis of wave propagation processes using high-performance computers
Adaptive mesh refinement (AMR) methods are absolutely essential in many industrial and scientific applications in order to reduce the numerical effort and thus make complex problems manageable in the first place. However, a look at the current literature on AMR reveals a number of shortcomings that still need to be resolved. In order to achieve local mesh refinement, either hybrid meshes consisting of simplex and tensor product elements or constraints must be used. However, both approaches inevitably lead to local accuracy losses. Furthermore, in industrial applications, linear approach functions are often used, which is why only algebraic convergence can be achieved. In the scientific environment, there are of course also approaches for complete hp-adaptivity. However, due to the complexity of their implementation, these methods are designed for networks with one hanging node per element edge/surface and have weaknesses when applied to highly dynamic processes (explicit time integration), as diagonal mass matrices are not available. It should be noted, however, that exponential convergence rates can be achieved compared to simple h-refinements. The mentioned problems can easily be eliminated by higher-order transition elements derived on the basis of the so-called mixed (transfinite) interpolation. The element formulation is based on quadrilateral or hexahedral elements in the reference domain and can couple arbitrary discretizations. In principle, a wide variety of element families can be coupled, which differ not only in size or order of approach. Since the functional space does not have to be restricted by constraints, there is no need to compromise on accuracy. For high-frequency, transient calculations, suitable methods for diagonalizing the mass matrix are also being developed in this project. The resulting element family forms the basis for dynamic mesh refinements. The special feature of this approach is the targeted combination of refinement and coarsening steps, which are carried out in each time step of the simulation. This allows optimal convergence rates to be achieved with the lowest possible numerical effort . In order to further increase the efficiency of the developed technique, the algorithms are prepared for high-performance computers. The outstanding properties of the proposed methodology are illustrated using selected examples of wave propagation. For this purpose, continuous structural monitoring by means of guided waves in microstructured materials and the analysis of seismic activities are used., This text was translated with DeepL
2022 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Technology-aware 3D Interconnect Architectures for heterogeneous SoCs manufactured in Monolithic 3D Integration
Monolithic 3D integration (M3D) is a disruptive technology for the design of 3D System-on-Chips. In contrast to more conventional 3D integration schemes, M3D permits a very dense integration of vertical interconnects between neighboring tiers. Together with extrinsic heterogeneity, i.e., the combination of tiers with different electrical characteristics, unprecedented opportunities for new architectural designs and extended system functionalities arise., These benefits have been proven by numerous works addressing processing elements and memories; yet, for on-chip communication architectures such as Network-on-Chips, only few related works exist. Further on, these works often neglect the significant impact of intrinsic heterogeneity caused by monolithic fabrication, such as process-related transistor degradations on higher tiers, interconnect degradations on lower tiers, or the non-uniform distribution of routing resources among tiers. Finally, previous works primarily exploit wire length reduction in 3D, yet do not consider the extended micro- and macroarchitectural design space., We want to address all of these shortcomings by analyzing how the characteristics of monolithic 3D integration affect the design of the microarchitecture of individual network components, and the architecture of the communication infrastructure. Furthermore, we will analyze the impact of these modifications and extended design options on the overall system architecture., The project will provide four specific contributions to the scientific community:, 1) It will provide systematic design guidelines and a set of architectural templates for optimized 3D interconnect architectures addressing extrinsic and intrinsic heterogeneity;, 2) it will provide models for formulating Network-on-Chip topology synthesis as an optimization problem;, 3) it will provide a toolset for supporting a systematic design space exploration, which accounts for all relevant M3D technology characteristics;, 4) it will demonstrate the optimization potential by means of two demonstrators, a Vision-System-on-Chip and a multiprocessor system., The main outcome of this project will be a deeper understanding on how the disruptive characteristics of Monolithic 3D integration can be exploited for improving the interconnect architecture in 3D integrated circuits. This allows for the design of optimized systems, not supported by current design concepts.
2022 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Rise, Fall or Transformation of the Experience Society?
Neuere Zeitdiagnosen zeichnen ein eher düsteres Bild der gesellschaftlichen Verhältnisse, so bspw. die "Flucht nach vorn: Die Erfolgskultur der Gegenwart" (Neckel 2008), die "Gesellschaft der Angst" (Bude 2014) oder die "Abstiegsgesellschaft" (Nachtwey 2016). Der Kontrast zu den Gesellschaftsdiagnosen vor der Jahrtausendwende ist beachtlich. Paradigmatisch für den Optimismus der 1980er und 1990er Jahre war die These der Erlebnisgesellschaft von Gerhard Schulze (1992): Angesichts des materiellen Überflus-ses für breite Schichten habe sich die Modernisierung von außen nach innen gewendet, weg von einer Orientierung auf Status und materiellen Erfolg hin zum fast spielerischen "Projekt des schönen Lebens". Infolge dessen seien auch soziale Ungleichheiten im Alltag der Menschen weitgehend irrelevant geworden, was Schulze als subjektive Entvertikalisierung bezeichnet. Konfrontiert mit den jüngsten Gegenwartsdiagnosen und der dort thematisierten steigenden ökonomischen Ungleichheit und Unsicherheit stellt sich daher die spannende Frage: Ist die Erlebnisgesellschaft schon wieder Geschichte? Oder leben wir immer noch - und vielleicht sogar mehr denn je - in einer Erlebnisgesellschaft? Oder hat sich die Gesellschaft angesichts neuer sozio-ökologischer Krisen und Herausforderungen (Stichworte: Nachhaltigkeit und Postwachstum) zuletzt in eine ganz andere Richtung entwickelt? In diesem Spannungsfeld der Zeitdiagnosen soll das beantragte Projekt eine Positionsbestimmung der deutschen Gesellschaft vor dem Hintergrund der Theorie der Erlebnisgesellschaft vornehmen, die im Jahr 2022 ihr 30-jähriges Jubiläum feiert. Wir erforschen, ob der Wandel zur Erlebnisgesellschaft trotz fragiler gewordener Rahmenbedingungen immer noch intakt ist (Szenario "Aufstieg der Erlebnisgesellschaft") oder sich wieder umgekehrt hat (Szenario "Fall der Erlebnisgesellschaft"). Dabei ist das Projekt auch offen für die Möglichkeit, dass die Gesellschaft mit dem neuen existenziellen Problem des "nachhaltigen Lebens" eine neue Entwicklungsrichtung eingeschlagen hat (Szenario "Transformation der Erlebnisgesellschaft").Um diese Positionsbestimmung vornehmen zu können, stellt das Projekt zwei Grundannahmen der Schulze’schen Theorie in den Mittelpunkt: die der innengerichteten Modernisierung in Richtung Erlebnisorientierung sowie die der subjektiven Entvertikalisierung der Gesellschaft. Diese Grundannahmen überprüfen wir bevölkerungsrepräsentativ im Zeitverlauf (ab ca. 1980 bis heute) für Deutschland und zusätzlich mit aktuellen Querschnittsdaten im internationalen - v. a. europäischen - Ländervergleich (ab ca. 2000 bis heute). Das Forschungsvorhaben ist in großen Teilen sekundäranalytisch angelegt, nur für das Thema der Transformation planen wir eine explorative Primärdatenerhebung. Unser Projekt ist nicht nur zeitdiagnostisch hochrelevant, sondern stellt, von vereinzelten Arbeiten abgesehen, seit langem ein soziologisches Forschungsdesiderat dar.
2022 to 2025
Deutsche Forschungsgemeinschaft (DFG)
A Common Storage Engine for Modern Memory and Storage Hierarchies
Scientific research is increasingly driven by data-intensive problems. As the complexity of studied problems is rising, so does their need for high data throughput and capacity. The globally produced data volume doubles approximately every two years, leading to an exponential data deluge. This deluge then directly challenges database management systems and file systems, which provide the foundation for efficient data analysis and management. These systems use different memory and storage devices, which were traditionally divided into primary, secondary and tertiary memory. However, with the introduction of the disruptive technology of non-volatile RAM (NVRAM), these classes started to merge into one another leading to heterogeneous storage architectures, where each storage device has highly different performance characteristics (e.g., persistence, storage capacity, latency). Hence, a major challenge is how to exploit the specific characteristics of memory devices., To this end, SMASH will investigate the benefits of a common storage engine that manages a heterogeneous storage landscape, including traditional storage devices and non-volatile memory technologies. The core for this storage engine will be B-epsilon-trees, as they can be used to efficiently exploit these different devices. Furthermore, data placement and migration strategies will be investigated to minimize the overhead caused by transferring data between different devices. Eliminating the need for volatile caches will allow data consistency guarantees to be improved. From the application side, the storage engine will offer key-value and object interfaces that can be used for a wide range of use cases, such as high-performance computing (HPC) and database management systems. Moreover, due to the widening gap between the performance of computing and storage devices as well as their stagnating access performance, data reduction techniques are in high demand to reduce the bandwidth requirements when storing and retrieving data. We will, therefore, conduct research regarding data transformations in general and the possibilities of external and accelerated transformations. As part of SMASH, we will provide a prototypical standalone software library to be used by third-party projects. Common HPC workflows will be supported through an integration of SMASH into the existing JULEA storage framework, while database systems can use the interface of SMASH directly whenever data is stored or accessed.
2022 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Optimierung des Betriebs von Wirbelschichtverfahren mittels maschinellen Lernens
Fluidized beds are the basis for scores of applications in which fast mixing, heat and mass transfer of gas and solid particles are essential. Their performance largely relies on the bubble dynamics: rising bubbles drive the solids circulation and significantly enhance gas-solids contact, improving mixing, reactions, and transport properties. So far, almost all fluidized beds are operated with a uniform gas flow. However, some recent academic work shows that operating a fluidized bed with an alternating gas flow (e.g. sinusoidal gas fluidisation velocity) leads to different bubble patterns and dynamics. In this project, we aim to control the bubbles in a fluidized bed, by application of computational intelligence (CI) methodologies such as evolutionary algorithms and genetic programming. We will use our lab-scale fluidized bed with camera system and our model developments in the Eulerian-Eulerian and Eulerian-Lagrangian frameworks to capture the dynamics of bubbles in the fluidized bed as the fluidizing gas velocity is spatio-temporally varied. Firstly, these results will be used to find the optimal inflow-pattern for given target functions. The challenge for the CI algorithm is to find the right balance between the computationally and timely intensive experimental data and the simulation data to efficiently deliver the required fluidization velocity profile. In addition, we aim to address multiple conflicting target functions using multi-objective optimization algorithms. Secondly, the CI algorithm will be used to steer and control the velocity profile, to obtain a specified bubble size and dynamics. Being able to control the behavior of the bubbles in a fluidized bed will significantly improve the desired outcome, such as product quality, efficiency and selectivity of the process, to name a few.
2021 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Stochastic Optimisation of Urban Delivery Systems with Micro Hubs
To compete with e-commerce giants such as Amazon, many local businesses start to offer fast same-day delivery, often within a few hours after an order was placed. Deliveries are conducted by local delivery fleets. However, the narrow delivery times and the geographical spread of pickup and delivery locations result in a lack of consolidation opportunities. This can be remedied by so-called micro hubs, which can serve as transhipment centres for parcels in urban delivery. Drivers can store parcels from adjacent shops for redistribution. They also can pick up parcels from different shops for joint delivery to customers in the same region. Thus, micro hubs can increase consolidation opportunities and may also enable the use of smaller, green, and clean vehicles for first and last mile delivery. Within this project, optimisation models incorporating consolidation centres in the pickup and delivery system of urban same day delivery are developed. Further, different solution approaches will be investigated to cope for the uncertainty in demand at time of planning.
2023 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Tribological optimization of hip endoprostheses through the development of an artificial synovial fluid and a novel hip tribometer
In Germany, around 200,000 people opt for an artificial hip every year and have their hip joint replaced with an endoprosthesis. The operation is one of the standard procedures in orthopaedic surgery. During movement, the hip prosthesis, in particular the sliding pairing between the ball of the femoral head and the socket, is exposed to heavy loads and therefore also to heavy wear. The mechanical work of the two friction partners in the joint causes considerable material abrasion, which can lead to inflammation of the surrounding tissue and subsequent loosening of the endoprosthesis, necessitating a hip prosthesis replacement. Replacing the hip prosthesis is made more difficult, however, because the endoprosthesis is more difficult to attach to the bone compared to the first operation. The reason for this is inflammation caused by the metal and plastic abrasion of the sliding partners in the artificial joint, which leads to a reduction in bone substance. The lubricating fluid of a healthy hip joint is the synovial fluid produced by the joint mucosa. Implantation and joint inflammation change the composition of this synovial fluid, which leads to a reduced lubricity of the fluid. In this, The aim of the proposed project is to investigate the properties of the synovial fluid before and after prosthesis implantation. With the help of the results obtained, a, artificial synovial fluid that meets the requirements for optimum lubrication of the implant. To investigate the tribological properties, a, A new type of test rig will be developed, which is designed as a femoral head ball/acetabular cup test rig and can measure the friction directly on the test pairing, taking into account a more realistic joint-like amount of lubricant (approx. 3-10 ml). This makes it possible to identify an optimum lubricating fluid for each sliding pairing and to test how the artificial synovial fluid resembles the human synovial fluid and which influencing factors have a positive effect on the lubricating properties. The aim is to develop an artificial synovial fluid with optimal lubrication conditions that can potentially be applied to patients in the future., This text was translated with DeepL
2022 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Implicit mobile human-robot communication for spatial action coordination with context-specific semantic environment modeling
The use of robots in the industry as well as in the work and everyday life is becoming more and more flexible. Current methods for machine learning and adaptive motion planning are leading to a more robust behavior and a higher autonomy of the robots. Nevertheless, collaborative human-robot interactions still happen to have interruptions and breakdowns in cases where the human is not able to comprehend the robot's movement behavior. A common cause is that the human has an incorrect or limited picture of what the robot is currently perceiving and what its internal state is. This could be avoided if the robot could understand and incorporate the mental states and the perspective of the interaction partner in its own action generation in order to actively generate a common understanding of the interaction.A key competence for such a collaboration between humans and robots is the ability of communication and mutual coordination via implicit signals of body language and movement. The project investigates the implicit human-robot communication in collaborative actions by using the example of the joint construction of a shelf. In experimental studies, situations will be created and recorded in which the interaction and perception between the human and the robot is disturbed. On the one hand, new perception methods are explored, that robustly detect interaction-relevant features based on head and body poses and facial expressions against occlusions. These are interpreted in the context of the action and the environment, so that implicit communication signals (e.g., turning toward, turning away, compliance, hinting, etc.) and internal states (e.g., approval, disapproval, willingness to interact, etc.) can be inferred. On the other hand, new methods are being explored to make the robot infer the perspective and the state of the human interlocutor in its own action planning and actively requests user reactions.This leads to a spatial coordination of the partners during the construction of the shelf by taking into consideration the mutual perception and the goal of the action. Via an active use of body pose, relative orientation and movement of the robot, conflict situations can be solved in advance without the need for explicit instructions to the robot.
2022 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Novel approaches for the integration of induced crystallization in biosynthetic processes: from new conceptual approaches to practicable solutions.
The project serves to investigate biocatalytic reaction systems and the integration of selective crystallization techniques. The main focus is on the synthesis of chiral amines and carboxylic acids. The project also includes the introduction of computational technology to predict, design and ultimately improve reactive crystallization in biosynthetic processes. This direct link to technical systems, including access to the necessary instruments, enables synergy effects with related research areas., This text was translated with DeepL
2021 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Übergangsmetall-nitrid-AlGaN Schichten mittets Sputterepitaxie für elektronische Anwendungen
Goal of this project is to identify specific TM-group-III-N layers with epitaxial quality for a potential application in group-III-nitride electronics. For this we will first study the properties of pure and alloyed group-IIIb-, -IVb-, and -Vb-nitrides (Cr, V, Ti, Sc, Nb, Zr, Ta, Hf) with AlN and in some cases also with GaN. This will result in a database of material parameters, namely crystal structure, lattice parameter, electrical and optical properties for a wide range of compositions., Their potential should be then evaluated within the framework of thin films applied as active layers, i.e. for polarization optimization in HEMTs, novel HEMT structures as, for example, GaN/ScN/GaN binary high mobility electron channels or as thicker films for an application as highly conductive buffer layer and electrically conducting strain engineering layers, enabling true vertical electronic devices on Si substrates. For the latter pure TMN alloys or TMN alloys with AlN are the most promising candidates, while for active layers, apart from binary TMN layers, also alloys with GaN are interesting.
2022 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Extension of fictitious domain methods for vibroacoustic issues - analysis of heterogeneous insulation materials
Predicting the acoustic behavior of systems containing materials with complex microstructure is a major challenge for several reasons. On the one hand, it is very time-consuming to build high-resolution numerical models using geometry-conforming discretizations and, on the other hand, all physically relevant interactions of the structure with both the surrounding and the enclosed fluid must be taken into account. The geometry-conform discretization of heterogeneous materials with complex microstructure usually leads to a very high number of finite elements and thus to unacceptable computing times. In recent years, fictitious domain methods, such as the Finite Cell Method (FCM), have emerged as an effective alternative. To capture the acoustic or vibroacoustic properties, the FCM must be extended in some aspects for the new field of application. First, the acoustic wave equation for calculations in the time domain and the Helmholtz equation for analyses in the frequency domain must be discretized using fictitious domain methods. Furthermore, suitable coupling strategies between the structural and fluid domains must be developed. The subfields can be coupled both weakly (without feedback) and strongly (with feedback). The advantage of fictitious domain methods is, in addition to the highly accurate resolution of the geometry (despite non-conformal discretization), the possibility of superimposing structural and fluid elements. This makes it possible to develop an effective strategy for the vibroacoustic coupling of heterogeneous materials. The numerical effort of these complex simulations is still very high, even when using fictitious domain methods. Therefore, another goal is to derive simplified models based on numerical homogenization methods in addition to the microstructurally resolved models. Despite the strong abstraction of reality, it is expected that useful results can be achieved for various applications. The final focus of the project is the experimental validation of the numerical methods developed. Various test rigs will be used for this purpose. The vibration behavior of the structure is crucial for the implementation of the vibroacoustic coupling. This can be investigated using a 3D laser scanning vibrometer. In addition, the frequency-dependent acoustic parameters are measured using various simple measurement setups, such as a Kundt's tube, and compared with the simulated results. Furthermore, the sound radiation is measured in a free-field room using microphone arrays and far-field microphones. On the basis of this data, the performance of the implemented models can be verified. Finally, guidelines for their use are derived., This text was translated with DeepL
2021 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Interdependencies of autophagy, protein synthesis, aging, activity and synaptic viability.
Synapses in the brain can persist for months and even years. Their proteinaceous components, however, become dysfunctional after much shorter periods, and thus must be continuously removed and degraded. Autophagy is one such removal pathway, mainly involved in clearance of protein complexes and aggregates. Significant evidence suggests that aging is associated with impaired protein clearance, and that manipulations that augment autophagy increase life-span and rejuvenate multiple physiological processes including several pertaining to synaptic and cognitive functions. Catabolic and anabolic processes are often coupled, and thus manipulations that enhance autophagy are likely to affect other aspects of protein metabolism. Our overall goal in this project is thus to gain a broader view of the effects exerted by such manipulations, using them to expose interdependencies among autophagy, protein synthesis, aging, activity, and synaptic viability. To that end we will examine how manipulations of autophagy affect (synaptic) protein synthesis and degradation in standard and aged neuronal cultures, in mice of different ages, and in mice raised in enriched environments. Long-term imaging will be used to examine how these manipulations affect autophagic flux, neuronal viability, synaptic persistence, tenacity and function, as well as resilience to stressors. Ultimately, we hope to use the obtained data to identify autophagy-associated targets for manipulations aimed at improving life-long neuronal and synaptic viability, and test a subset of these within the consortium.
2022 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Dynamic Mesh Refinement Exploiting High-Order Transfinite Elements for the Analysis of Wave Propagation Phenomena on High-Performance Clusters
Adaptive mesh refinement (AMR) strategies are of interest in many branches in science and engineering. Due to the possibility to generate locally refined discretizations, large-scale problems of practical relevance become tractable. However, a review of the state of the art in AMR reveals several issues that are not sufficiently resolved yet. First, often only low-order finite elements in combination with h-extensions are applied in commercial codes resulting in a sub-optimal convergence of algebraic type. Additionally, to ensure a conformal coupling, either unstructured discretizations consisting of both simplex and tensor-product elements have to be utilized or the ansatz space of the elements has to be constrained reducing the overall accuracy of the approach. Second, high-order hp-type refinement strategies, mainly implemented in a research environment, suffer from restrictions to 1-irregular meshes to decrease the implementational complexity or are based on hierarchic shape functions that do not permit the construction of diagonal mass matrices which is essential for (explicit) transient analyses. However, these methods are at least capable of delivering exponential rates of convergence. Therefore, a novel methodology to construct dynamically refined meshes based on (nodal) high-order quadrilateral and hexahedral finite element types is proposed. Fortunately, the aforementioned drawbacks can easily be overcome by employing the so-called transfinite interpolation technique (Gordon-Coons interpolation) enabling the construction of arbitrary transition elements. In principle, it is possible to couple elements of different types, sizes, and polynomial orders without any compromise on the attainable accuracy. This unique versatility opens up a wide variety of possible applications for this element type. Additionally, highly accurate mass lumping schemes are developed to facilitate the application to transient analyses. The proposed novel family of elements constitutes the cornerstone for implementing a dynamic refinement strategy, where both refinement and coarsening steps are executed in each time step of a dynamic analysis. Hence, optimal rates of convergence can be achieved with minimal numerical effort. To increase the efficiency of the proposed framework even further, all algorithms are implemented in a high-performance computing framework. The exceptional properties of the novel methodology are showcased using different numerical examples from the area of wave propagation analysis, where dynamic mesh refinement techniques are indispensable for a numerically efficient simulation. To this end, guided waves in the context of structural health monitoring in micro-structured materials and seismic wave propagation over large regions are discussed.
2023 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Structure, heat, elasticity and their interplay in soft polymer-based composites across different length scales
Heisenberg funding, Project description according to DFG, see GEPRIS (, https://gepris.dfg.de/gepris/projekt/413993216, ):, "The aim of the Heisenberg Program is to enable outstanding academics who meet all the requirements for appointment to a long-term professorship to prepare themselves for an academic leadership role and to work on further research topics during this time. In pursuing this goal, it is not always necessary to select and implement project-based approaches. For this reason, in contrast to other funding instruments, no "summary" of project descriptions and project results is required when submitting applications or later when writing final reports. Consequently, such information is also not made available in GEPRIS.", This text was translated with DeepL
2022 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Mechanismen der Differenzierungsentscheidung einer eukaryontischen Zelle
The development and fate of a eukaryotic cell is controlled by complex networks of, interacting biomolecules. They regulate the differential expression of genes that drive the, process of cell differentiation or that are required to execute this process. There is a, tremendous body of information available on the regulatory mechanisms of gene expression in, eukaryotic cells and on the cell type-specific expression of transcription factors and other, regulators. However, the overall functional interplay of these molecules in determining the fate, of a differentiating cell or the identity of a stem cell which is able to differentiate into various, specialized cell types, is not really understood. Gene regulatory mechanisms in prokaryotes, the, lambda switch that controls the entry of the phage into the lytic cycle for example, are well-, established (Delbrück 1949; Kafri et al. 2013) and influence our thinking. The situation in, eukaryotes however is more complex with combinatorial control of gene expression. In, eukaryotes, many molecular factors can act together in binding to promoter regions, thereby, controlling the expression of a certain gene, often in a context-dependent manner. This variety, makes it very difficult to integrate the many pieces of knowledge on local molecular, mechanisms into a coherent picture or even into a mechanistic model of regulatory control that, would predict the differentiation behavior of the cell. Thus, while we can see expression, changes on a global scale and deduce connections between genes, we are currently only at the, beginning of discriminating and understanding cause and effect. This situation basically holds, for all eukaryotic cells, from Dictyostelium to mammalian cells. In well-studied yeasts for, example, interaction networks on gene expression and protein abundance levels were, described (e.g. Moignard et al. 2015), but even those detailed analyses yielded just static, pictures of potential hubs and interactions of components, while it is known that the dynamics of, regulation essentially determines the final outcome (Endres 2012; Rowland et al. 2012; Varusai, et al. 2015; Vilar et al. 2003)., Some regulatory networks are known to involve developmental switches that give rise to so, called commitment points, at which the decision on the cell fate is irreversibly made., Commitment points in the cell cycle of yeasts are related, well-known paradigms for the control, of cell proliferation (Zachariae and Tyson 2016). Here, essential molecular players and their, fuctional interactions in generating irreversible switches are well understood. Co-regulated with, the cell cycle, the protein abundance is adjusted by modulating gene expression (Eser et al., 2011). In contrast however, commitment points that decide on the differentiation destiny of a, eukaryotic cell are currently not well understood., There are two prevailing and in part contradicting views of how the differentiation of, eukaryotic cells is controlled, both dating back to the year of 1969 (Britten and Davidson 1969;, Kauffman 1969a; Kauffman 1969b) and both pursued and elaborated until today ((Thomas, 1981; Abou-Jaoudé et al. 2016; Peter and Davidson 2011; Bornholdt and Kauffman 2019) and, references therein). The model by Britten and Davidson (Britten and Davidson 1969) assumes a- 2 -, hierarchical control based on uni-directional information flow (Peter and Davidson 2011), assuming complex connections but without variability, acting like the rigid steering mechanics of, a technical device. The model by Kauffmann (Bornholdt and Kauffman 2019; Kauffman 1969a;, Kauffman 1969b) on the other hand explains the global dynamics of gene regulation by a, system of interconnected switches. While there are good arguments in favour for each of both, competing views, direct experimental proof or disproof is pending and obviously difficult, (Newman 2020)., Intrinsic transcriptional heterogeneity is widely observed in clonal populations of, mammalian cells in culture, but also occurs in intact tissues under physiological conditions, (Marco et al. 2014). Approaches to explain this heterogeneity while considering the global, dynamics which is expected for a complex gene regulatory network (and which the Britten-, Davidson model neglects), are based on the Kauffman model and have been metaphorically, illustrated by Waddington's epigenetic landscape (Huang et al. 2009; Waddington 1957). Here, the global dynamics of the regulatory network is explained by a quasi-potential landscape, in the, following simply called Waddington landscape, that represents possible states of the dynamic, system while defining the probabilities for state transitions to occur ((Graf and Enver 2009;, Huang 2011; Huang et al. 2009; Macarthur et al. 2009; Moris et al. 2016; Wu et al. 2017; Zhou, and Huang 2011); Fig. 1A). Although there are theoretically sound formal frameworks that, principally allow to compute the quasi-potential landscape from a set of differential equations, these approaches have currently still limited practical value simply because the molecular, interactions within considered regulatory networks are not sufficiently known and hence, differential equations and their parameters are elusive. Experimental analysis, on the other, hand, would require the measurement of true time-series in individual cells but such approaches, are still in the fledgling stages, at least in mammalian cells., The reconstruction of pseudo-time series from static snapshots taken of mammalian cell, populations depends on certain assumptions and unequivocal conclusions are hardly possible, for principle reasons (Weinreb et al. 2018). This limitation however, tends to be neglected or, even ignored for the sake of simplicity. Until recently, the Waddington landscape, and the, existence of attractors, accordingly remained a theoretical concept. It is supported by many, experimental observatios, while basic features, including the functional role of stochasticity, are, still a matter of pure speculation ((Moris et al. 2016) and references therein)., We have overcome this limitation by developing an experimental system that allows to, take true time series, i.e. to test the same cell all over again. True time series for individual cells, can be taken by repeated, non-destructive sampling retrieving just small parts of the stirred, cytoplasmic volume of the giant amoeba Physarum polycephalum. In these multinucleate cells, the cytoplasm is homogenous due to continuous mixing by the vigorous cytoplasmic streaming, (Guttes and Guttes 1961, 1964; Rusch et al. 1966; Sachsenmaier et al. 1972; Starostzik and, Marwan 1995a; Walter et al. 2013) (Pretschner et al. 2021). Based on our single cell data we, have developed an appropriate computational approach to identify attractors, to reconstruct the, Waddington landscape from gene expression time series, and to disentangle the complex, response revealing the differential regulation of the individual genes (Rätzel et al. 2020;, Werthmann and Marwan 2017; Pretschner et al. 2021). We have shown that cells, as predicted, by the model of the Waddington landscape, take individually different gene expression routes, (trajectories) to sporulation and that these routes converge to highly similar states of gene, expression. These findings however are only valid for the small set of 35 genes analysed in the, respective studies. Although our work resulted in a proof of principle, the molecular details of, developmental switching and especially of the commitment point have, due to the limited size of, the data set, not yet been identified. Neither in Physarum nor in mammalian cells it is clear, whether all cells of a population do cross the same commitment point or might use alternative, commitment points with different molecular signatures and mechanisms, that all might lead to, the same differentiated state. These fundamental questions are addressed in the proposed, project and the generation of the necessary data sets simply depends on funding.
2024 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Initiation of international collaboration on the crystal structure, microstructure and mechanical properties of precipitation hardened Fe-Cu-Ni-Ti-Al complex concentrated alloys
Since the CCAs are being actively explored for next-generation structural materials for high-temperature applications and therefore, they should have a high creep resistance besides that a comprehensive understanding of their creep and fracture behaviors is also indispensable., Among the several anomalies existing in the creep behavior of HEAs, the foremost important is the stress exponent, n, calculated from the Berkovich nanoindentation creep tests turns out to be much larger than that calculated based on the uniaxial stress relaxation and spherical nanoindentation creep tests, and this could not be explained using classical creep theory for crystalline metals. It is still uncertain whether the classical creep theory for conventional metals are applicable for the HEAs., The Fe32.3Al29.3Cu11.7Ni10.8Ti15.9 CCA, developed by OVGU-HT Materials group – whose compression behavior was studied under a constant displacement test with quasi static strain rate between room temperature (RT) and 1100°C revealed a stable single phase bcc microstructure with precipitates at the grain boundaries. The high temperature deformation and creep behavior of this material will be studied during a 3 months visit of Prof. Puspendu Sahu, Professor of Physics), Jadavpur University, Kolkata, India. In addition, TEM analyses are planned to perform at Jadavpur University with the deformed materials to get insights into the deformation mechanisms.
2022 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Mechanism of agglomeration in spray drying with the fine particle recirculation
Powders manufactured by spray drying often require an additional enlargement step, which is mainly carried out either outside the drying tower or by recycling dry undersized particles into the drying tower. In this project, we advance the knowledge in the enlargement of powders in spray drying with fines return, targeting both the process quality and product quality. An efficient prediction tool within a computational fluid dynamics (CFD) framework is constructed and assessed by means of spatially and temporally resolved pilot-scale plant experiments.
2022 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Molekulare Mechanismen der Notch3-abhängigen Immunzellinfiltration, Entwicklung einer fibrogenen Niche und Nierenfibroseentstehung
ME 1365/7-3, Chronische Nierenerkrankungen betreffen etwa 10% der Allgemeinbevölkerung und stellen aufgrund der hohen Kosten und Chronizität eine große Belastung für das Gesundheitssystem dar. Bei der Mehrzahl der Betroffenen kommt es zu einem nicht reversiblen Rückgang der Nierenfunktion. Die zugrundeliegenden Ursachen sind vielfältig und reichen von arterieller Hypertonie, Hyperglykämie bis hin zu Autoimmunerkrankungen. Es entwickelt sich eine progressive tubulointerstitielle Fibrose mit Verlust der Nierengewebsarchitektur und einem Rückgang der Anzahl der Nephrone. Es ist ein enger zeitlicher und räumlicher Zusammenhang der Nierengewebsschädigung mit tubulointerstitieller Zellinfiltration und einer "aktivierten" fibrogenen Nische nachweisbar. Unsere Arbeitsgruppe sowie andere identifizierten die Rezeptoren der Notch-Familie als zentrale Regulatoren des Nierenschadens. Mäuse mit einer genetischen Ablation des Notch3 Rezeptors sind vor experimentellen Nierenerkrankungen wie der Harnleiterobstruktion und der nephrotoxischen Serumnephritis geschützt. Die grundlegende Rolle des Notch3 Rezeptors für die zelluläre Antwort auf Gewebeschäden wird bei diesen Tieren durch die Beobachtung einer schwächeren Integrin-Aktivierung, einer geringeren Leukozyteninfiltration in das Gewebe und fehlende Aktivierung des NF-kB-Signalweges unterstrichen. Unsere neueren Ergebnisse definieren eine zellspezifische Funktion des Notch3 Rezeptors. Dabei konnte zum einem die Funktion des Notch3 Rezeptors in nierenresidenten Zellen (z.B. tubuläre sowie tubulointerstitielle Zellen und Mesangialzellen) und zum anderen in peripheren Immunzellen beschrieben werden., Die Ergebnisse werden unser Verständnis zur Pathophysiologie chronischer Nierenerkrankungen mit dem Fokus auf ein Schlüsselrezeptormolekül vertiefen. Diese werden genutzt, um Interventionsstrategien mit zellspezifischer Behandlung sowohl einer Entzündungsreaktion als auch der Organfibrose zu gestalten.
2022 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Improvement of the numerical efficiency of rotordynamic simulations by applying the Scaled Boundary Finite Element Method to compute the hydrodynamic bearings
The rotordynamic properties of systems with hydrodynamic bearings are affected crucially by the nonlinear bearing forces. Regarding fast-rotating, lightly-loaded rotors, this causes subsynchronous self-excited oscillations with potentially high amplitudes, which can reduce the durability of the components, cause critical noise emissions, and affect the energy efficiency of the machine. To reduce expensive test bench experiments and time-consuming iterations in the product development process, the design has to be based on precise simulative analyses of the operating behavior under consideration of the nonlinear interactions between the bearing forces and the shaft vibrations. To this end, the equation of motion of the elastic shaft is incorporated into a time integration scheme and coupled with the Reynolds equation, which describes the pressure generation in hydrodynamic bearings. Hence, each time step of the simulation includes a solution of the Reynolds equation, for which numerical methods, analytical approximations, and look-up tables are employed. While numerical methods lead to considerable and often inacceptable computational times, analytical solutions are only possible in conjunction with substantial simplifications. The look-up table approach, to some extent, offers a tradeoff between these two extremes, while the modeling depth is usually limited, since the interpolation effort increases with every considered physical effect., A promising basis for the development of a novel, numerically efficient solution without the substantial limitations of analytical methods or look-up table techniques is the semi-analytical Scaled Boundary Finite Element Method (SBFEM). The fundamentals for solving the Reynolds equation with the SBFEM have been derived in preliminary work, but the potential of the approach has not been exploited yet, which is the objective of this project. In order to further reduce the numerical effort, high-order shape functions need to be employed in combination with an automatic, adaptive mesh refinement as well as coarsening and a transformation of the Reynolds equation in a manner that smoothens the solution is analyzed. Another strategy worth investigating is to avoid the repeated solution of eigenvalue problems within the time integration scheme. This requires that the eigenvalue problem is differentiated with respect to the parameters of the shaft displacement and developed into a series prior to the rotordynamic simulation. In order to improve the modeling depth of the SBFEM solution compared to the preliminary work, strategies for incorporating mass-conserving cavitation models as well as shaft tilting need to be investigated. In the last step, the developed methodology is to be verified and analyzed with regard to its efficiency. To ensure a realistic context, this is done within the framework of a rotor dynamics or MBS formulation, whereby complex technical overall systems can also be simulated.
2023 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Visual peripheral perception in virtual reality
Based on the results of the previous project, there are further, research deficits, especially related to the understanding of the, coupling of peripheral visual stimuli, eye-tracking motion, and action., This leads to theoretical and methodological challenges, especially in, complex situations as they exist in sports. Using appropriate VR tools, systematic and standardized studies are conducted with the following, objectives: • Comparison of peripheral perception and motor response, to these signals in head-mounted displays (HMD) and in the real, world (RW) • Influence of different peripheral signals in head-mounted, displays (HMD) on eye-following movements and motor response behavior in complex situations. From this, the following theoretical, insights are expected: • Similarities and differences of peripheral, vision in RW and VR • Further established findings on the functionality, of peripheral perception in RW and VR • Influence of the perception of, different visual peripheral signals on the movement action.
2023 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Tribologische Optimierung von Hüftendoprothesen durch Entwicklung einer künstlichen Synovialflüssigkeit und eines neuartigen Hüft-Tribometers
In Deutschland entscheiden sich jährlich rund 200.000 Menschen für eine künstliche Hüfte und lassen ihr Hüftgelenk durch eine Endoprothese ersetzen. Die Operation gehört zu den Standardeingriffen in der orthopädischen Chirurgie. Die Hüftprothese ist während der Bewegung, insbesondere die Gleitpaarung zwischen Hüftkopfkugel und Pfanne, starken Belastungen und daher auch einem starken Verschleiß ausgesetzt. Durch mechanische Arbeit der beiden im Gelenk befindlichen Reibpartner wird ein nicht unerheblicher Materierialabrieb erzeugt, welcher zu einer Entzündung des umliegenden Gewebes und einer nachfolgenden Lockerung der Endoprothese führen kann und ein Hüftprothesenwechsel erfordert. Der Hüftprothesenwechsel wird allerdings erschwert, weil die Endoprothese sich im Vergleich zur ersten Operation schlechter im Knochen befestigen lässt. Ursache hierfür ist Entzündung verursacht durch den Metall - und Plastikabrieb der Gleitpartner im künstlichen Gelenk, welche zu einer Abnahme der Knochensubstanz führen. Die Schmierflüssigkeit eines gesunden Hüftgelenks ist die von der Gelenkschleimhaut produzierten Synovialflüssigkeit. Durch Implantation und Gelenkentzündung verändert sich die Zusammensetzung dieser Synovialflüssigkeit, was zu einer verminderten Schmierfähigkeit der Flüssigkeit führt. In dem hier beantragten Vorhaben sollen die Eigenschaften der Synovialflüssigkeit vor und nach Prothesenimplantation näher untersucht werden. Mit Hilfe der gewonnenen Ergebnisse soll eine künstliche Synovialflüssigkeit hergestellt werden, welche den Anforderungen der optimalen Schmierung des Implantats gerecht wird. Zur Untersuchung der tribologischen Eigenschaften soll ein neuartiger Prüfstand entwickelt werden, der als Hüftkopfkugel/Pfanne-Prüfstand ausgeführt ist und die Reibung unter Berücksichtigung einer realistischeren gelenkähnlichen Schmiermittelmenge (ca. 3-10 ml) direkt an der Prüfpaarung messen kann. So wird es möglich für jede Gleitpaarung eine optimale Schmierflüssigkeit zu identifizieren und zu prüfen wie die künstliche Synovialflüssigkeit der humanen Synovialflüssigkeit gleicht und welche Einflussfaktoren die Schmiereigenschaften positiv beeinflussen. Ziel ist es, eine künstliche Synovialflüssigkeit mit optimalen Schmierbedingungen zu entwickeln, welche potentiell in Zukunft im Patienten appliziert werden kann.
2022 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Gradual Functional Changes
With the advance of computer facilities and data storage warehouses, more and more data are being recorded continuously during a time period or intermittently at plethora of discrete time points. These are both examples of functional data, which furthermore embrace random fields or manifolds. Our attention is devoted to stochastic functions predominantly represented by random curves or surfaces, where every function is considered as a single observation. These observations are naturally ordered with respect to time and possibly changing over time. The interest is not in an individual change withineach curve, but in a change of the pattern across the sequence of curves. Almost all existing change detection methods are designed to discover abrupt breaks. Little attention has been paid to smooth structural changes, which may be more realistic in practice. With the vantage of functional analysis and empirical processes, we can deploy advanced statistical tools like bootstrap or lasso to diagnose the gradual change of functional form in the time series of random curves.
2020 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Lead-free programmable multistable piezo-thermal actuators (LEAP)
We aim to develop novel multistable and programmable actuators based on the combination of piezoelectric and thermal actuation. Whilst generally creating new performance and functionality compared to present piezo actuators, we address the key challenge of implementing lead-free alternatives to conventional lead-ziconate-titanate (PZT) based ceramics.
2022 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Role of Filamin A in integrin-dependent dendritic growth and hippocampus function
Filamin A (FlnA) is a large dimeric protein that can cross-link actin fibers and serve as a bridge between the cytoskeleton and cell membrane integrins. Mutations in the FlnA gene in humans result in periventricular heterotopia, in which neurons aggregate along the lateral ventricles due to impaired migration. Therefore, previous research has focused on the importance of FlnA for neuronal migration and its contribution to neuron maturation is not well understood. However, we and other groups have shown that the actin cytoskeleton and integrins play important roles in dendrite development and plasticity. In concrete preliminary work for this project, we have also collected evidence that FlnA is significantly involved in the formation of dendritic branches in hippocampal neurons. Using molecular biology, anatomical, electrophysiological and behavioural methods, we now investigate the cellular mechanisms underlying the involvement of FlnA in dendritic growth and determine the role of these processes in hippocampal-dependent information processing and memory formation.
2022 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Development and systematic validation of a system for contactless, camera-based measurement of the heart rate variability
Heart rate variability (HRV) provides important information for the medical analysis of the cardiovascular system and the activity of the autonomic nervous system, as well as for the diagnosis and prevention of diseases. Traditional HRV monitoring systems are contact-based techniques that require sensors to be attached directly to the person's body, such as an electrocardiogram (ECG) or contact photoplethysmography (PPG). These techniques are only partially suitable for long-term monitoring or early detection of disease symptoms. In addition, they can have some negative effects on the monitored person, such as skin irritations, an increased risk of spreading disease germs due to direct contact, etc.The aim of this research project is the optical measurement of heart rate variability (HRV) from video images using PPG. PPG is an optical, non-invasive technology that uses light to record volumetric variations of blood circulation in the skin. In recent years, this technique has been realized remotely and contact-free through the use of cameras and has already been successfully used for the measurement of heart rate (HR) from video data. For the measurement of HRV a precise temporal determination of the heartbeat peaks in the PPG signal is necessary. The high measurement accuracy of HR in the state of the art can only be achieved by a strong temporal filtering. However, this makes it impossible to localize the heartbeats precisely over time. A challenge is that even smallest movements and facial expressions of the test persons lead to artifacts in the PPG signal. This is where this research project takes effect, by systematically detecting these artifacts in the PPG signal and subsequently compensating them. Up to now, almost all methods for measuring the PPG signal have been based on color value averaging of (partial) areas of the skin in the face. Movement compensation is not possible with these methods because position informations is lost. To train models that are invariant to movement, deep neural networks (Convolutional Neural Network (CNN)) are well suited. Using 3D head pose estimation methods and action unit recognition (facial muscle movements), a system will be trained to extract motion-invariant PPG signals from video data. For this purpose, information on detected skin regions in each image will be generated using new segmentation methods based on CNN and used for motion compensation. The data obtained by this network will be further processed with another recurrent neural network (Long Short-Term Memory (LSTM)) optimized for temporal signal processing in order to determine the pulse peaks in the PPG signal precisely in time.
2022 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Intravascular crosstalk of interleukin-6 and therapeutic glucocorticoids in SARS-CoV2 infection
SARS-CoV2 is highly infectious and causes the disease COVID-19. 10-20 % of patients infected with SARS-CoV2 develop severe symptoms. In these patients, SARS-CoV2 can trigger a cytokine storm that leads to the life-threatening Cytokine Release Syndrome (CRS). Among the cytokines released, Interleukin-6 (IL-6), a paradigm pro-inflammatory cytokine with deleterious functions, correlates strongly with and predicts the severity of COVID-19. Noteworthy, systemic vascular complications in critically ill COVID-19 patients represent a main risk. The expression of SARS-CoV2 entry factors on vascular cells in virtually all organs suggests that vascular damage could be a consequence of lytic viral infection of vascular cells. However, it is also discussed that impaired vessel function is mediated by loss of function of non-infected vascular cells exposed to systemically elevated levels of IL-6. In addition, SARS-CoV2 may locally affect IL-6 signalling pathways by controlling the expression and release of IL-6 receptor subunits and IL-6 itself. The suspected role of IL-6 in the development of COVID-19 is the basis for several ongoing clinical trials with approved drugs that either inhibit IL-6 function extracellularly or intervene in intracellular IL-6 signal processing. However, the molecular mechanisms and pathophysiological consequences of IL-6 and the causes of vascular damage in COVID-19 are still unknown., Preliminary results from clinics show that immunosuppressive glucocorticoids (GC) reduce deaths in certain patient groups by for so far unknown reasons. Remarkedly, both extracellular and intracellular IL-6 signalling is influenced by GC and, vice versa, IL-6 influences GC signalling. To address the increasing concerns about the efficacy of GC treatment for COVID-19 and possible (adverse) effects of GCs on the vascular system, the molecular mechanisms of GC action in SARS-CoV2-infected cells and the crosstalk of GC and IL-6 must be elucidated., The aim of this project is to gain profound translational knowledge about molecular mechanisms and pathophysiological consequences of IL-6 and GC action in SARS-CoV2-infected cells and non-infected vascular cells. For this purpose, we will use highly defined, 2D and 3D in vitro, vascular models and single cell techniques to define the consequences of SARS-CoV2 infection in the two integral vessel cell types, endothelial cells and smooth muscle cells. The results obtained will be a prerequisite for understanding SARS-CoV2 infection and targeted development of treatments to cope with COVID-19.
2018 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Analysis of forced periodic modes of operation using the example of methanol synthesis (SPP 2080)
Methanol is an important raw material in the chemical industry, which is traditionally produced in large quantities from synthesis gas using heterogeneous Cu/ZnO/Al_2 O_3 catalysts under stationary conditions. The present project investigates the extent to which methanol synthesis can be improved by forced periodic operation. The project is part of the DFG priority program SPP 2080 "Catalysts and reactors under dynamic operating conditions for energy storage and conversion"., This text was translated with DeepLCompleted projects
2021 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Tissue engineering von Lymphgefässen unter Mikrogravitation ohne Scaffolds und Protein analysis in extracellular vesicles from dermal microvascular endothelial cells from patients with systemic sclerosis
Die klinische Forschungsgruppe der MTRM unter Leitung von Prof. Infanger konzentriert sich auf das Gebiet der rekonstruktiven Chirurgie einschl. Handchirurgie, freier Lappenplastiken und, Lymphchirurgie, ebenso auf die Themen Tissue Engineering und Tumorforschung. Supermikrochirurgische Lymphchirurgie als neues Verfahren zur Behandlung von, Patienten mit Lymphödem ist nur mit den Mikroskopen der Neuen Generation möglich.
2021 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Optimizing graph databases focussing on data processing and integration of machine learning for large clinical and biological datasets
Graphdatenbanken stellen eine effiziente Technik zur Speicherung und zum Zugriff auf hochgradig, verknüpfte Daten unter Verwendung einer Graphstruktur dar, wie z.B. Verbindungen zwischen Messdaten zu Umweltparametern oder klinischen Patientendaten. Die flexible Knotenstruktur macht es einfach, die Ergebnisse verschiedener Untersuchungen hinzuzufügen. Dies reicht von einfachen Blutdruckmessungen über die neuesten CT- und MRT-Scans bis hin zu hochauflösenden Omics-Analysen (z.B. von Tumorbiopsien, Darmmikrobiom-Proben). Allerdings wird das volle Potenzial der Datenverarbeitung und -analyse mittels Graphdatenbanken in biologischen und klinischen Anwendungsfällen noch nicht vollständig ausgeschöpft. Insbesondere die riesige Menge an miteinander verbundenen Daten, die geladen, verarbeitet und analysiert werden müssen, führt zu zu langen Verarbeitungszeiten, um in klinische Arbeitsabläufe integriert werden zu können. Um dieses Ziel zu erreichen sind neuartige Optimierungen von Graph-Operatoren sowie eine geeignete Integration von Analyseansätzen notwendig., Dieses Projekt zielt darauf ab, die oben genannten Probleme in zwei Richtungen zu lösen: (i) Vorschlag geeigneter Optimierungen für Graphdatenbank-Operationen, auch unter Einsatz moderner Hardware, und(ii) Integration von Algorithmen des maschinellen Lernens für eine einfachere und schnellere Analyse der biologischen Daten. Für die erste Richtung untersuchen wir den Stand der Technik von Graphdatenbanksystemenund deren Speicherung sowie ihr Verarbeitungsmodell. Anschließend schlagen wir Optimierungen für effiziente, operationale und analytische Operatoren vor. Für die zweite Richtung stellen wir uns vor, Algorithmen des maschinellen Lernens näher an ihre Datenlieferanten - die Graphdatenbanken - heranzubringen. Zu diesem Zweck füttern wir in einem ersten Schritt die Algorithmen des maschinellen Lernens direkt mit dem Graphen als Eingabe, indem wir geeignete Graphenoperatoren entwerfen. In einem zweiten Schritt integrieren wir das maschinelle Lernen direkt in die Graphdatenbank, indem wir spezielle Knoten hinzufügen, die das Modell des Algorithmus für maschinelles Lernen repräsentieren., Die Ergebnisse unseres Projekts sind verbesserte Operatoren, die sowohl moderne Hardware als auch Integrationskonzepte für Algorithmen des maschinellen Lernens nutzen. Unsere allgemein entwickelten Ansätze werden das Verarbeiten und Analysieren riesiger Graphen in einer Fülle von Anwendungsfällen über unseren angestrebten Anwendungsfall der biologischen und klinischen Datenanalyse hinaus vorantreiben.
2021 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Multi-scale coupling of the vascular hemodynamics for an AI-assisted, standardized evaluation of neurological pathologies
Neurovascular diseases can lead to severe limitations and disabilities in affected individuals and are also among the leading causes of death in Germany. Particularly patient-specific changes in the cerebral vessels are expressed, for example, in the form of so-called intracranial aneurysms (permanent, balloon-like vessel bulges) or arteriovenous malformations (abnormal connections of arterial and venous vessels without capillary bed). Although continuously evolving imaging modalities enable a reliable diagnosis, individual risk assessment is highly complex, subject to numerous influencing variables, and too simplified in clinical practice due to the lack of models. As a result, the optimal treatment decision is challenging., In the context of this research project, a holistic approach to evaluate neurovascular pathologies shall be realized by means of multi-scale modeling. First, the cardiovascular hemodynamics are described by means of a one-dimensional model. Subsequently, the neurovascular circulation and the venous system are mapped in 3D using computational fluid dynamics. Through this highly individualized and AI-assisted approach, the aforementioned pathologies can be precisely described morphologically and hemodynamically to computationally track their growth and remodeling processes along the time scale. For the time scale, time-dependent 4D flow measurements and tomographic image data are employed as well as longitudinal studies., After the successful realization of the modeling "from the aorta to the vein", the project aims to standardize the developed in-silico models via a usability module within the framework. In parallel, high-resolution in vitro validation measurements will be performed to ensure the plausibility of the models. Finally, the transfer of the developments into a scoring system is planned in order to prepare an application in the clinical environment. The standardization as well as the scoring system will exploit methods based on artificial intelligence (AI). This comprises the image- and mesh-based preprocessing and evaluation of flow simulation (with focus on deep learning) as well as the classification of extracted parameters (with focus on machine learning)., In summary, the planned holistic approach to assess neurovascular pathologies enables a highly interdisciplinary combination of patient-specific hemodynamics with medical imaging, AI-based image processing and evaluation, and simulative description. Consequently, transferring these influencing variables and conditions into a standardized assessment system can enable a precise and risk-free assessment of the actual disease state for the patient.
2020 to 2025
Deutsche Forschungsgemeinschaft (DFG)
The role of inclusions in thin, functionalized, elastic or viscoelastic layers, films and membranes
For a description of the project, see GEPRIS (, https://gepris.dfg.de/gepris/projekt/413993436, ):, "Increased mechanical strength is one of the advantages of reinforcing elastic materials with embedded fibers. This allows the dimensions of workpieces to be reduced. In extreme cases, bulky components can be replaced by elastic membranes, thin layers and films. Our overarching goal is to develop theoretical-analytical methods to efficiently describe such thin elastic composite materials. As a first step towards this goal, we investigate the role of particle-like inclusions in thin elastic environments. First, the mutual interactions of the inclusions due to deformations of the elastic membrane are characterized, as well as their influence on the global properties of the membrane. With a view to a later holistic description that can be adapted to the respective situation, methods for characterizing different individual cases are then developed. In addition to purely static elasticity, these include dynamic viscoelasticity, different membrane surface conditions, thermal and thermophoretic effects when the inclusions are heated from the outside, and the associated actuation. In addition to inclusions in thin films, the adsorption of particles on membranes and the resulting deformation effects are also discussed in part. While we initially have to limit ourselves to flat and linearly elastic membranes, nonlinear elasticity and curved membranes will also be considered. The functionalization with particle-like inclusions already promises a broad spectrum of tailor-made applications. Examples could include special loudspeaker membranes, switchable membranes for the controlled release of drugs or even thin actuators. In a broader context, our results can also support the interpretation of data from AFM (atomic force microscopy) measurements and are also important for aspects of the targeted manipulation of biological cell membranes for technical applications. Building on the results obtained here, our long-term goal is the theoretical description of fiber-reinforced thin elastic composite materials.", (DFG procedure for grants in kind), This text was translated with DeepL
2023 to 2025
Deutsche Forschungsgemeinschaft (DFG)
26592_ Extension of fictitious domain methods for vibroacoustic issues - analysis of heterogeneous insulation materials
The project is dedicated to the development of an efficient calculation method for solving three-dimensional vibroacoustic problems using porous insulation materials. The aim is to resolve the microstructure of the insulation material in order to overcome the current limitations of Biot's theory, which is often used and seems particularly unsuitable for modeling closed-cell foams. In order to enable the extremely complex geometry-resolved modeling we are aiming for, fictitious domain methods with higher-order approach functions are to be used. On the one hand, these can be applied very advantageously to voxel data and, on the other hand, a high efficiency for wave propagation problems can be expected.
2021 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Methodologies of Economic Criticism
The network "Methodologies of Economic Criticism" will systematise, compare and evaluate the diverse and partially overlapping methodologies within English Studies that constitute the burgeoning, yet still inchoate field of Economic Criticism - an interdisciplinary research area that explores the various interconnections, past and present, between literature, culture, the economy and economics. As a reaction to the financial crisis of 2007/8 and global challenges with clear links to the economy (e.g. climate change, economic inequalities, automation, digitalisation, migration), Economic Criticism is currently flourishing in English Studies and the humanities more broadly. Despite an outpouring of publications, however, a decidedly methodological approach to analysing literature, culture and the economy is still missing. The network will fill this research gap by uniting scholars from three German-speaking countries, who have longstanding expertise in different approaches to Economic Criticism and who represent four sub-disciplines of English Studies. As its main goal, the ‘intra-interdisciplinary’ network will jointly develop and publish a "Handbook: Methodologies of Economic Criticism" providing a comprehensive, critical and historically informed overview of established and innovative analytical tools for scrutinising economic concerns with the means provided by (Anglophone) literary studies, cultural studies and postcolonial studies. A second goal is to implement the findings into academic teaching, by developing a set of teaching materials on Economic Criticism for tertiary education. For this purpose, the network also includes members with a background in didactics.
2021 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Patterning valence specific amygdala memory by dorsal tegmental area (DTA) and ventral tegmental area (VTA) dopamine (DA) subsystems
The amygdala is a key structure for the association of Pavlovian conditioned (CS) to unconditioned (US) stimuli. The basolateral complex of the amygdala (BLA) integrates CS information from the auditory cortex and aversive US information from thalamic and sensory cortical inputs. Signals are then relayed via an inhibitory network of primarily central lateral amygdala (CEl) SST+ and PKC delta+ neurons to basal forebrain and the brainstem nuclei, thereby controlling fear behaviors (Tovote, 2016). Dopamine (DA) neurons located in the dorsal tegmental area (DTA neurons), are interconnected with the basolateral (BLA)- central amygdala (CE) circuitry. The CE-projecting DTA neurons send a prediction error coupled DAergic reinforcement signal to the CE. Importantly, this, signal rewires the BLA to CEl neuronal connectivity by shifting the weight from PKC delta+ to SST+ synapses (Groessl, 2018; Li, 2013). The amygdala has been mostly investigated in aversive fear learning,but there is increasing recognition that the BLA-CE network encodes also reward behaviors. However, the specific BLA-CE circuit rearrangements underlying discriminatory associative reinforcement learning related to negative or positive experiences are not resolved.The ventral tegmental area (VTA) and the mesolimbic reward system also project to the BLA/CE network. Therefore, we propose that BLACE circuitry unifies both negative and positive associative learning by DTA and VTA coupled reinforcement signals, respectively. In support of this view, VTA neuron activity and amygdala DA levels, likely originating from the VTA, increase during reward learning (Correia, 2016). Likewise, DTA neuron activity and amygdala DA levels (Groessl, 2018), in part originating from DTA cells (unpublished), are strongly increased during exposure to aversive experience. Thus, these two circuits might represent two distinctly different midbrain systems recruited during positively and negatively rated learning paradigms. Moreover, D1 vs. D2 DA receptors are asymmetrically distributed in the genetically defined neuronal subtypes. Here, a simple assumption would imply that DTA and VTA differentially innervate SST+ and PKC delta+ cells. We therefore hypothesize that negatively valenced fear and positively valenced reward signals generate memory traces that differentially map on the genetic BLA to SST+ and BLA to PKC delta+ circuit architecture. We propose that DA originating from the DTA reinforces BLA to SST+ synapses during fear learning, while DA arising from the VTA, enhances BLA to CEl PKC delta+ synapses during reward learning. If we will find that aversive and rewarding stimuli affect the network in the same direction, the simple hypothesis would have to be rejected in favor of control of synaptic transmission by DA along the anatomical rostro-caudal gradients (Kim, 2017) rather than along genetically defined neuronal types.
2021 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Politics in Search of Evidence (PoSEvi) -The role of Political Philosophy and Public Health in the political responses to COVID-19
Das Projekt ist Teil einer Forschungskooperation zwischen dem Institut für Sozialmedizin und Gesundheitssystemforschung (ISMG) und der Hochschule für Philosophie München. Das Projekt wird geleitet von Prof. Dr. Michael Reder (Hochschule für Philosophie München) und Prof. Dr. Dr. Christian Apfelbacher (ISMG, Medizinische Fakultät, OvGU Magdeburg)., Ziel des Teams in Magdeburg ist es, zu erforschen und zu verstehen, wie Epidemiolog:innen/Public Health-Wissenschaftler:innen das Verhältnis zwischen ihrer Disziplin und der politischen Entscheidungsfindung wahrnehmen, wie Epidemiolog:innen/Public Health-Wissenschaftler:innen ihre eigene Rolle als Wissenschaftler:innen und Bürger:innen mit politischer Meinung aushandeln, wie Epidemiolog:innen/Public Health-Wissenschaftler:innen das Verhältnis zwischen ihrer und anderen wissenschaftlichen Disziplinen wahrnehmen, welche normativen Annahmen Epidemiolog:innen/Public Health-Wissenschaftler:innen bei der Produktion und Verbreitung von Forschungsergebnissen machen, wie politische und kulturelle Kontexte das Selbstverständnis von Epidemiolog:innen/Public Health-Wissenschaftler:innen und ihr Verhältnis zur Politik beeinflussen., Neben einer systematischen Analyse von themenbezogenen Dokumenten (Positionspapiere, Stellungnahmen, Fact sheets etc.) werden Interviews mit Expert:innen aus den Subdisziplinen der Epidemiologie und aus dem Bereich Public Health durchgeführt. Das Forschungsvorgehen orientiert sich an den Prinzipien der Grounded Theory (Methodology) mit dem Ziel der Entwicklung eines theoretischen Modells zum Verhältnis von evidenzbasierter Politik und Wissenschaft., Von Projektbeginn an sowie insbesondere bei der Interpretation der Daten ist ein intensiver Austausch mit dem Forschungsteam der Hochschule für Philosophie vorgesehen., Die Ergebnisse werden abschließend im Rahmen eines Stakeholder-Dialogs vorgestellt und diskutiert.
2021 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Robuster Entwurf und Regelung von Power-to-Methanol Prozessen mit Methoden des maschinellen Lernens (SPP 2331)
Im Rahmen der Energiewende spielt die Herstellung von grünem Methanol eine wichtige Rolle. Dazu wird überschüssiger Strom aus erneuerbaren Energien (Wind, Sonne) in Wasserstoff umgewandelt, der dann mit Hilfe von CO und CO_2 aus organischen Abfällen zu Methanol umgesetzt wird. Da die Ver-fügbarkeit dieser Ausgangsstoffe/Energie starken zeitlichen Fluktuationen auf unterschiedlichen Zeitskalen unterliegt, werden neue Konzepte für den robusten Prozessentwurf und die robuste Prozessführug benötigt. Dazu werden im Rahmen des vorliegenden Projektes datengetriebene Ansätze des maschinellen Lernens verwendet. Das Projekt ist im DFG Schwerpunktprogramm SPP 2331 "Machine Learning in Chemical Engineering" angesiedelt.
2021 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Investigation of complex amino acid and amine-based in situ product crystallization strategies in transaminase- and amine dehydrogenase-catalyzed reactions and their development into flow reaction concepts.
Transaminases are extremely selective biocatalysts for the synthesis of chiral amines. Unfortunately, numerous applications of these biocatalysts involve unfavorable equilibrium positions and thus low atomic efficiencies in the asymmetric synthesis direction, which have to be compensated for at great expense. Multi-stage biocatalytic cascade reactions, an over-stoichiometric use of the donor amine and special donor amines with non-enzymatic side reactions are common. the research project presented takes this limitation into account and aims to enable the direct removal of the product amine from the reaction solution by selective in situ crystallization in an integrated process approach. The crystallization of the product amine is to take place specifically through the formation of a sparingly soluble salt, which is thereby continuously removed from the reaction solution in the course of the biocatalytic reaction. This should then shift the reaction equilibrium to the product side and at the same time separate the product (as a salt) from the reaction solution by means of simple filtration. Ultimately, the concept is to be transferred to continuous process control, including full recycling of the unreacted reactants to overcome the low atomic efficiency, up to the multi-gram scale. The research project is structured into 7 work packages and 2 milestones, which will address the issue in a structured manner, starting with the screening of suitable acids through to optimized integrated reaction control. After selecting suitable acids for the crystallization of the amine, the salt pairs will be characterized and the reaction conditions adapted for efficient coupling for various transaminases. The scale-up including continuous reaction control will then be established. Finally, the selective crystallization of the co-product pyruvate will be investigated, which may lead to an equilibrium shift., This text was translated with DeepL
2022 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Coupled 3D CFD model for the calculation of piston ring packs taking into account mixed friction, dynamics and structural deformations
In view of the demand for increasing efficiency and power density of machine elements, there is a need for new 3D simulation methods that are as detailed as possible. Flow simulation using CFD (computational fluid dynamics) to investigate lubricated tribological systems will become increasingly important in the future. In many applications, complex fluid-structure interactions prevail, which significantly influence the system behavior. In addition to the existence of several phases, multi-body dynamics, structural deformations and mixed friction conditions are frequent boundary conditions in these tribological systems. The aim of this project is therefore to develop methods for integrating these influences into CFD. A suitable application to be used as an example for this is the piston ring pack as part of the piston/cylinder pairing of combustion engines. On the one hand, it offers an interesting and diverse field of application, as combustion engines will continue to play a significant role in the future due to further optimizations and the use of new synthetic fuels, and the piston/cylinder pairing tends to be responsible for the largest proportion of engine friction. On the other hand, it is a sophisticated system for which no CFD models exist to date that take into account all of the aforementioned influences in the necessary level of detail., The novel calculation approach, which is intended to improve the investigation of the blowby quantity and friction, consists of the development of a 3D CFD model of the piston ring pack coupled with user-defined functions. Of particular importance here are the three-dimensional dynamics and deformation of the piston ring, which are to be represented by an FE model. This involves not only implementing the coupling with the fluid mechanical solution and the solid contact, but also developing efficient algorithms for adapting the three-dimensional calculation meshes. In addition, a mixed friction model and a model to take into account lubricant storage in the honing profile of the cylinder are to be implemented. Finally, the overall model will be validated using the measurement results of a floating liner test rig., As part of the proposed research project, it is expected that generally applicable methodological skills for the three-dimensional calculation of fluid-structure interactions in lubricated machine elements will be acquired. At the end of the project, in addition to comprehensive details on the friction and transport mechanisms within the piston ring package, findings and 3D partial models for coupling multiphase CFD with models for mixed friction, structural dynamics and user-defined network dynamics will be available, which can be transferred to other lubricated machine elements., This text was translated with DeepL
2022 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Lattice-Boltzmann simulations of particulate flows
Turbulent flows laden with particles are ubiquitous in a wide range of industrial and natural processes including biomass combustion, pollutant transport, sand storms, icy clouds, etc. In most of these applications particle shape is not spherical. Numerical simulation of turbulent flows with non-spherical particles is complicated because the orientation and distribution of particles play an important role and can significantly modify flow and turbulence behavior. Most numerical studies dealing with turbulent flows involving non-spherical particles are limited to point particles. However, when particles become larger than the Kolmogorov length scale, simulations become more complex and demand large computational efforts. Very few numerical studies of turbulent flows with interface-resolved non-spherical particles can be found in the scientific literature up to now. Most of these studies have considered isothermal conditions. However, heat transfer from/to particles can again significantly alter all flow properties. Hot particles can also modify the turbulence spectra through pressure dilatation. Such effects have never been addressed thoroughly in the past. The goal of this study is to bridge this gap by performing direct numerical simulation (DNS) of turbulent flows containing non-spherical particles and considering heat transfer effects. Given the complexity of the problem and very high computational costs required for the simulations, a lattice Boltzmann method (LBM) solver is chosen for this study. Due to the locality of all operations, parallel computations are straightforward with LBM. Moreover, it can relatively easily be applied to complex domains, which makes it suitable for the purpose of the present proposal. To this end, an immersed boundary method (IBM) combined with an LBM solver will be employed. In order to deliver information relevant for practical applications, the final simulations will consider a pipe flow, opening the door for a better physical understanding of important phenomena like particle position in catalytic reactors, or fouling in heat exchangers. Such DNS (here based on LBM) will improve our understanding of the physical transfer mechanisms. Combining turbulence, non-isothermal and fluid dynamics aspects and considering the mutual interactions that occur during the motion of non-spherical particles are the central goals of this proposal. The results of this study will also enable practical progress concerning heat transfer enhancement, possibly coupled to drag-reduction effects.
2022 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Dissecting pathogen persistence- versus clearance-promoting functions of monocyte-derived cell populations during L. major infection
Tissue damage and infection results in the massive recruitment of immune cells from the bloodstream. Among these recruited cells, the monocytes give rise to a versatile system of phagocytes which can take up and neutralize pathogens, activate the adaptive immune system, but also induce tissue repair. Despite intense investigation in a variety of disease models, it has remained unclear how the different functions of specific monocyte subsets are induced after recruitment to the tissue, and how these functions contribute to the control of infections. This question is especially important for the infection with intracellular pathogens such as, L. major, , for which monocyte-derived cells can serve both as niches for intracellular growth of the pathogen, but also as effector cells fighting the infection., In our previous work, we have identified distinct subsets of monocyte-derived cells that harbour, L. major, with different intracellular proliferation rates, exhibit characteristic gene expression patterns, and are differentially engaged by effector T cells. How such differences relate to distinct effects of the individual monocyte-derived subsets, i.e. to what extent they promote intracellular survival and persistence of the pathogen, or pathogen clearance by activating the immune system, is unclear yet., The objective of the proposed research is therefore to investigate the following questions:, (1) How are the monocyte-derived cell subsets are recruited to, and activated at, the site of L. major skin infection?, To achieve this, we will employ fluorescent reporter systems that allow us to track in vivo the recruitment and activation of monocytes to the site of infection., (2) How do the different subsets interact with T cells and modulate T cell effector functions?, For this, we will investigate by intravital 2-photon microscopy in vivo, and by live cell imaging and RNA sequencing ex vivo, the capacity of different monocyte-derived cell subsets to interact with and activate effector T cells., (3) How do candidate genes shown to be specifically expressed in distinct monocyte-derived cell subsets impact on the role of these subsets in promoting pathogen persistence versus clearance?, To investigate this question, we will apply mixed bone marrow chimeric models combined with partial cell depletion to address cell-intrinsic versus cell extrinsic effects of candidate gene deficiencies on pathology and infection course., The proposed research should critically contribute to our understanding of the mechanisms and dynamics of how different monocyte-derived cell subsets impact on the course of infection. Given the widespread involvement of monocytes in a variety of infectious, inflammatory and malignant diseases, elucidating the mechanisms that control such immunostimulatory versus immunomodulatory functions could guide novel therapeutic strategies targeting this balance specifically in monocytes.
2020 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Adaptive plasticity of brain structure and function in response to consecutive stress exposure: assessing the role of endocannabinoid receptors as mediators of resilience
The major aim of this project is to unravel neurobiological, cellular, molecular, and epigenetic events that mediate the development of stress resilience versus stress vulnerability in a rat model of early life stress (ELS). The overarching hypothesis is that vulnerable as well as resilient individuals exist and that exposure to ELS (1st hit) induces different or contrasting adaptive plasticity processes in the respective animals. We will test if repeated exposure to stress at different stages of development, ELS as 1st "hit” and swim stress at juvenility as 2nd "hit” will have lasting effects on neuronal networks in the brain, specifically those mediating affect regulation and social approach and reward. More specifically, we will analyze if rats classified as resilient or susceptible following the 1st hit and subsequently exposed to a 2nd hit at juvenility will demonstrate the same phenotype at adulthood, that is, resilient animals will remain resilient throughout the lifespan, whereas susceptible animals may display exacerbation of symptoms following the 2nd hit (cumulative stress concept)., On the mechanistic level we will address two complementary hypotheses of ELS-induced brain plasticity. First, we hypothesize that a) the mPFC-amygdala-NAc circuit is central in understanding vulnerability vs resilience due to its continuous and significant maturation during juvenility ; b) the long-term effect of ELS-induced "stress-inoculation” vs vulnerability is sex-specific and is conferred c) by activity-induced changes in the expression of synaptic plasticity proteins within specific neuronal ensembles, which confer d) structural long-term changes in synaptic connectivity and plasticity. Second, we hypothesize that ELS-induced resilience is conferred e) by changes in CB1 receptors, whose expression f) is epigenetically re-programmed by ELS. Finally, the project will also elucidate if and in which way pharmacological interventions on the endocannabinoid system may be effective in normalizing behavioral pathology and in epigenetic "reprogramming” of ELS-induced brain functions., This multidisciplinary project is essential in order to disentangle the factors that moderate the long-term effects of ELS, which is crucial for identifying the biological underpinnings of resilience and characterizing neural circuits and molecular pathways involved in (re-)programming mechanisms.
2020 to 2025
Deutsche Forschungsgemeinschaft (DFG)
Inter- and transgenerational consequences of early life adversity on oxytocin-receptor gene expression
Experience-driven maturation of neuronal and behavioral functions represents a fundamental principle of functional brain development. During brain development, genetically preprogrammed events interact with environmental and psychological ‘epigenetic’ factors, which results in ‘fine-tuning’ of neuronal networks in order to adapt to an individual´s environment and to generate appropriate responses to environmental challenges. Studies in humans as well as in various animal models have shown that the exposure to one or multiple forms of early-life adversity (ELA), such as childhood stress, abuse and neglect, constitutes a major risk factor for developing somatic and behavioral disorders and in the etiology of a wide range of mental diseases. Increasing evidence, including those from our own studies, demonstrated that negative and positive environmental early-life experiences critically interfere with the maturation of brain structure and function . Hence, synaptic circuitries adapt or maladapt to a given environment, which - in the case of adverse experiences such as socio-emotional neglect, abuse, and trauma - can lead to dysfunctional neuronal circuitries, and thereby contribute to the aetiology of mental and behavioral disorders. Moreover, evidence is emerging that behavioral and brain structural/functional consequences of ELA can be transmitted to the next generations, however, the detailed mechanisms underlying inter- and transgenerational transmission of ELA are still poorly understood., Based on these findings the aim of this project is to compare the inter- and transgenerational transmission of ELA-induced changes in behavior and in prefrontal and hippocampal Oxytocin-receptor (OxtR) expression, including the underlying epigenetic regulation, in male and female offspring (F1 and F2 generation) of stress-exposed mothers (F0 generation)., We expect that the brain of individuals, which were exposed to ELA, suffers from dysfunctional neuronal circuits in prefrontal and hippocampal areas, which hinders their behavioral flexibility and adaptations to the environment. We will focus on the oxytocinergic system (specifically the expression of the OxtR) based on our previous investigations, where we observed a) depressive-like and ADHD-like behavioral phenotypes in ELA animals, b) impaired maternal care behavior in ELA females (F0 generation) towards their offspring (F1 generation) and c) decreased OxtR gene-expression in the PFC of ELA exposed F0 females. We will address the working hypothesis (a) that the ELA induced decrease in OxtR gene expression in the brain and oocytes of adult female mice (F0 generation) is a) epigenetically regulated and b) transmitted to their F1 and F2 offspring via © maternal behavior and/or (d) via the maternal germline.
2021 to 2024
Deutsche Forschungsgemeinschaft (DFG)
Aldehyddehyrogenasen als metabolische Instruktoren der Tumorimmunologie (AMINO, M-020)
Strategisch-gefördertes Kooperationsprojekt zum wissenschaftlichen Austausch zwischen der Volksrepublik China und Deutschland. Das Projekt wird zu gleichen Teilen aus den Mitteln der nationalen Forschungsorganisationen finanziert (Deutsche Forschungsgemeinschaft/DFG und National Natural Science Foundation of China/NSFC). Die Förderung dient der Unterstützung von Experten als besonders vielversprechender Sino-Deutscher Kooperationen aller Wissenschaftsbereiche. Inhaltlich wir im Projekt untersucht, in wie fern die Klasse der Aldehyddehydrogenasen (ALDH), metabolische Enzyme mit Bedeutung in der positiven Regulierung der Tumorstammzellen, die Immunogenität von Tumoren beeinflusst.
2021 to 2024
Deutsche Forschungsgemeinschaft (DFG)
Auswirkung der Vaskularisierung des Hippocampus auf neuronale Ressourcen des MTL und assoziierter neurokognitive Netzwerke
Dieses Projekt bildet das B04 Projekt des SFB 1436 "Neural Resources of Cognition". Das Ziel dieses Projektes ist es, zu untersuchen, wie sich die präzise Architektur der Gefäße im Hippocampus auf die individuellen kognitiven Ressourcen bei jüngeren und älteren Menschen auswirkt. Ich leite dieses Projekt zusammen mit Dr. Anne Maass and Prof. Stefanie Schreiber.
2019 to 2024
Deutsche Forschungsgemeinschaft (DFG)
Bayesian semiparametric models with time series errors
Bayesian time series analysis is becoming increasingly popular in the specialist literature., Modeling is often based on a stationary centered time series., In many relevant cases, however, such a time series is not the primary object of interest, but is merely used as an error term in a model with an additional (finite-dimensional) "parameter of interest"., Examples range from linear models (with model coefficients as parameters of interest) to structural break models (with the structural breaks as parameters of interest) to non-linear regression (with regression function as parameter of interest)., If you do not want to restrict yourself to a finite-dimensional time series model for the error term, it is possible to model it non-parametrically - in this case, it is referred to as a semi-parametric model., Although there is some work on Bayesian semiparametric models in the literature, few semiparametric approaches have been developed in the time series context., There are also hardly any theoretical findings, particularly with regard to asymptotic considerations., We consider a Bayesian semiparametric linear model, with error term consisting of a stationary centered time series, which is modeled nonparametrically with a Bernstein-Hpd-Gamma prior for the spectral density matrix in conjunction with Whittle likelihood., The results of the procedure are evaluated in a comparative simulation study., For the important special case of the expected value model, contraction rates of the joint a posteriori distribution and a Bernstein-von Mises result for the marginal a posteriori distribution of the expected value are also derived., This text was translated with DeepL
2021 to 2024
Deutsche Forschungsgemeinschaft (DFG)
Gaze track representation in high-level visual cortex
When we look at a face, we carry out distinctive eye movements leading to gaze paths that can easily be discriminated from the gaze paths elicited by other objects. It is well-known that frontal and parietal areas support the planning and execution of such eye movements. However, we recently showed that face and house-specific gaze tracks can be decoded in the fusiform face area (FFA) and the parahippocampal place area (PPA) - even in the absence of a face or house to look at. We concluded that action (gaze) patterns are represented in high-level visual cortex, demonstrating a potential neural basis for close interactions of perception and action. While we think we have presented solid evidence for this counterintuitive mapping of complex gaze patterns in high-level perceptual areas, many questions as to their nature and function remain., In the first experiment of the present proposal, we want to investigate the nature of this novel finding, specifically at what time the critical information is represented in a gaze track and if it is coded in the sequence or rather the location of fixations. In a second experiment, we want to learn if the gaze tracks elicited when identifying a face respectively identifying a facial emotion expression are represented in different perceptual brain areas. Finally, we plan to investigate if microsaccades elicited during face viewing are represented in a similar way as saccades in the FFA.
2021 to 2024
Deutsche Forschungsgemeinschaft (DFG)
The NMDA receptor complex - a signalling hub at the origin of cognitive flexibility?
The aim of our project is to unravel the contribution of the NMDAR signalling hub to cognitive flexibility. We will focus our analysis on subregions of the frontal cortex involved in cognitive flexibility. We will combine a sophisticated behavioural paradigm in mice (attentional set shifting) with state-of-the-art, highly sensitive proteome analyses deciphering molecular, cellular and network properties of cognitive flexibility. In particular, the effect of age, environmental and cognitive enrichment, and circadian strain on the NMDAR signalling hub will be assessed with the aim to identify key players in the different subregions of the frontal cortex.
2022 to 2024
Deutsche Forschungsgemeinschaft (DFG)
Die Wirkung des Einsatzes KI gestützter Technologie zur Lügenerkennung in Verhandlungen
Die zunehmende Digitalisierung gesellschaftlicher und ökonomischer Interaktionen verläuft mit, einer erheblichen Geschwindigkeit. Forschung zu Digitalisierungsprozessen sollte dabei zwei Erkenntnisgegenstände, miteinander in Einklang bringen, die für gewöhnlich allerdings getrennt voneinander, untersucht werden: Erstens die Frage der technischen Entwicklung und zweitens die, Frage der Auswirkungen dieser Entwicklung auf menschliches Verhalten. In dem hier beantragten, Projekt soll der Versuch unternommen werden, beide Perspektiven in einem interdisziplinären, Zugang miteinander zu verbinden, wobei der Schwerpunkt zwar auf der Verhaltensanalyse liegt, die technische Komponenten aber dennoch stark vertreten ist. Der Anwendungsfall, der für diese, Art der Analyse von Digitalisierungsprozessen gewählt wird, ist das Phänomen asymmetrischer, Information., Asymmetrisch verteilte Information spielt in vielen ökonomischen Kontexten eine wichtige Rolle., Informationsasymmetrien sind verantwortlich für Adverse Selektion (Akerlof, 1978) und Moral Hazard, auf Versicherungsmärkten, spielen im Human Resource Management eine große Rolle und, verhindern, dass bilaterale Verkaufsverhandlungen sicher zu effizienten Lösungen führen, (Kennan and Wilson, 1993). Bisher gab es kaum eine Möglichkeit, diese Asymmetrien zu beseitigen, weil die asymmetrisch verteilte Information privater Natur ist. Nur das jeweilige in einer, Verhandlung stehende Individuum kennt sie. Deshalb konzentrierte sich die Forschung lange auf, die Frage, ob es Anreizsysteme gibt, unter denen die wahrheitsgemäße Offenbarung privater, Information eine beste Antwort sein kann (Myerson and Satterthwaite, 1983). In der jüngsten Zeit, hat sich die Situation insofern geändert, als es mit Methoden der künstlichen Intelligenz (KI) möglich, geworden ist, aus der Mimik von Menschen auf Gefühlszustände zu schließen, um so beispielsweise, detektieren zu können, ob gelogen wird oder nicht (Pérez-Rosas et al., 2015). Es ist, davon auszugehen, dass angesichts der fortschreitenden Digitalisierung die Qualität derartiger, Algorithmen weiter zunehmen wird. Künstliche Intelligenz umfasst hier vor allem das Forschungsgebiet Maschinelles Lernen, in dem ein künstliches System anhand von Beispielen trainiert wird und zwar so, dass es anschließend für unbekannte Daten verallgemeinert., Das Projektvorhaben verbindet zwei Forschungsbereiche: Wirtschaftswissenschaften (WW) sowie, Neuro-Informationstechnik (NIT). In beiden Bereichen spielt die Identifikation privater Information, eine große Rolle, wird jedoch aus unterschiedlichen Blickwinkeln betrachtet. Während die, ökonomische Analyse sich auf die Rolle und Wichtigkeit privater Information in Verhandlungssituationen, fokussiert, steht bei NIT die Machbarkeit und Qualität einer automatisierten Erkennung, persönlicher Charakteristiken im Vordergrund. Dass das Zusammenwirken beider Forschungszweige, erfolgreich möglich ist, wird anhand der gemeinsamen Publikation der Antragsteller, (Othman et al., 2019) deutlich., Im Zentrum dieses Forschungsvorhabens stehen mehrere Fragen. Die ökonomisch bedeutsame, Frage ist, ob und wie Menschen auf die Existenz einer wenig invasiven Technologie zur Lügendetektion, reagieren. Dabei wird es einerseits darum gehen, wie Menschen mit den Informationen, umgehen, die eine KI erzeugt und zum anderen, wie sich die bloße Existenz einer solchen Technologie, auswirkt. Es wird untersucht, ob Institutionen (zum Beispiel Märkte), die die automatisierte, Erkennung privater Information benutzen, Institutionen vorgezogen werden, die auf diese Technik, verzichten. Aus technischer Perspektive soll geklärt werden, wie gut eine KI gestützte Technologie, in der Lage ist, einfache Lügen im ökonomischen Kontext zu erkennen. Die Forschungsfragen, lassen sich wie folgt zusammenfassen., Aus ökonomischer Sicht, werden folgende Forschungsfragen untersucht:, 1. Wie wirkt sich die Existenz einer KI basierten Technologie zur Detektion von Lügen a priori, auf das Kommunikationsverhalten und insbesondere auf den Gebrauch von Lügen aus?, 2. Wie nutzen Menschen die Informationen über die Ehrlichkeit ihres Verhandlungspartners, die die KI gestützte Technologie Ihnen präsentiert?, 3. Kommt es durch die Existenz derartiger KI Technologien zu Marktselektionseffekten? Unter, welchen Umständen werden Akteure ein Marktdesign vorziehen, das KI gestützte, Technologie einsetzt oder auslässt?, Aus ingenieurstechnischer Sicht stehen folgende Forschungsfragen im Vordergrund:, 1. Inwiefern ist die Detektion von Lügen in simplen Verhandlungssituationen mit finanzieller, Incentivierung mittels einer KI gestützten mimischen Expressionsanalyse möglich?, 2. Wie lässt sich die Detektion von Lügen durch die Hinzunahme weitere Modalitäten, z.B., der automatisierten, bildbasierten Vitalparameterschätzung verbessern?, 3. Wie können die Klassifikationsmodelle interpretiert, der Einfluss unterschiedlicher Modalitäten, bewertet und Merkmale, die zur Detektion von Lügen geeignet sind, identifiziert, werden?, Das Projekt nutzt die KI-Technologie, um die Frage zu beantworten, wie sich individuelles Verhalten in Konfliktsituationen mit privater Information durch die Existenz solcher Mechanismen ändert. Dies geschieht mit Hilfe incentivierter Laborexperimente und des Einsatzes der KI-Technologie. Die finale Forschungsfrage ist, ob die alleinige Existenz solcher Technologien die Menschen in ihrem Verhalten beeinflusst. So wird Käufern und Verkäufern die Möglichkeit gegeben, sich für oder gegen diese Technologie zu entscheiden, um Zugriff auf private Informationen des Verhandlungspartners zu erlangen. Damit befasst sich das Projekt mit ökonomischen Konsequenzen der Digitalisierung im Bereich des Marktdesigns. Es soll untersucht werden, wie sich die Akteure in entsprechende Teilmärkte selektieren und ob die Märkte überhaupt, zustande kommen. Diese Forschungsfrage ist von hoher praktischer und wissenschaftlicher Relevanz., Der Einsatz von KI wird in den nächsten Jahren stark zunehmen und in immer mehr Anwendungen auftreten. Angesichts dieser Entwicklung ist es von hohem gesellschaftlichem und wissenschaftlichem Interesse zu wissen, wie die Verwendung solcher Technologien das Verhalten der betroffenen Akteure beeinflusst. Dies ist sowohl für die Beantwortung der Frage nach den Wohlfahrtseffekten der KI als auch für konkrete Fragen des Marktdesigns relevant. Eine hervorhebenswerte Stärke des Projektes zu ist, dass das erwartete Lügeverhalten durch entsprechende laborexperimentelle Methoden incentiviert ist und die KI auf incentivierten Datensätzen lernen kann. Die KI gestützte Technologie, die in dem Projekt zum Einsatz kommt, ist allerdings nicht nur geeignet, Lügen zu detektieren, sondern kann ganz allgemein dafür verwendet werden emotionale Zustände aufzudecken. In diesem Zusammenhang stellt sich zusätzlich die Frage, ob eine höhere Transparenz der emotionalen Zustände der Verhandlungsteilnehmer Auswirkungen auf den Verlauf der Verhandlungen bzw. auf deren Ergebnisse hat. Als ein Nebenprodukt können die im Rahmen des Projekts gesammelten methodischen Erfahrungen zur Analyse emotionaler Reaktionen dazu genutzt werden, um Beweggründe von Versuchspersonen in anderen Laborexperimenten auf eine neue Art zu analysieren.
2022 to 2024
Deutsche Forschungsgemeinschaft (DFG)
Die Wirkung des Einsatzes KI gestützter Technologie zur Lügenerkennung in Verhandlungen
Die zunehmende Digitalisierung gesellschaftlicher und ökonomischer Interaktionen verläuft mit einer erheblichen Geschwindigkeit. Forschung zu Digitalisierungsprozessen sollte dabei zwei Erkenntnisgegenstände miteinander in Einklang bringen, die für gewöhnlich allerdings getrennt voneinander untersucht werden: Erstens die Frage der technischen Entwicklung und zweitens die Frage der Auswirkungen dieser Entwicklung auf menschliches Verhalten. In dem hier beantragten Projekt soll der Versuch unternommen werden, beide Perspektiven in einem interdisziplinären Zugang miteinander zu verbinden, wobei der Schwerpunkt zwar auf der Verhaltensanalyse liegt, die technische Komponenten aber dennoch stark vertreten ist. Der Anwendungsfall, der für diese Art der Analyse von Digitalisierungsprozessen gewählt wird, ist das Phänomen asymmetrischer Information. Konkret wird untersucht, inwieweit das Paradigma der asymmetrischen Informationsverteilung durch den Einsatz von KI Technologien zumindest teilweise obsolet geworden ist. In unserem interdisziplinären Projekt möchten wir, anstatt die technologische Entwicklung auf dem Gebiet der maschinellen Lügendetektion abzuwarten, unsererseits zum technologischen Fortschritt beitragen und gleichzeitig die möglichen gesellschaftlichen Folgen dieser Technologie experimentell untersuchen.Das Projektvorhaben verbindet zwei Forschungsbereiche: Wirtschaftswissenschaften (WW) sowie Neuro-Informationstechnik (NIT). In beiden Bereichen spielt die Identifikation privater Information eine große Rolle, wird jedoch aus unterschiedlichen Blickwinkeln betrachtet. Während die ökonomische Analyse sich auf die Rolle und Wichtigkeit privater Information in Verhandlungssituationen fokussiert, steht bei NIT die Machbarkeit und Qualität einer automatisierten Erkennung persönlicher Charakteristiken im Vordergrund.Das wesentliche Ziel ist die Beantwortung der zwei Fragen. (1) Kommt es durch die Existenz derartiger KI-Technologien zu Marktselektionseffekten? (2) Unter welchen Umständen werden Akteure ein Marktdesign vorziehen, das KI gestützte Technologie einsetzt oder auslässt? Als wesentliche Teilziele möchten wir herausfinden, wie gut sich das Lügen in unserem Verhandlungskontext maschinell erkennen lässt und wie die Probanden mit den Informationen dieser KI-Technologie umgehen.Damit befasst sich das Projekt mit ökonomischen Konsequenzen der Digitalisierung im Bereich des Marktdesigns. Es soll untersucht werden, wie sich die Akteure in entsprechende Teilmärkte selektieren und ob die Märkte überhaupt zustande kommen. Diese Forschungsfrage ist von hoher praktischer und wissenschaftlicher Relevanz. Der Einsatz von KI wird in den nächsten Jahren stark zunehmen und in immer mehr Anwendungen auftreten. Angesichts dieser Entwicklung ist es von hohem gesellschaftlichem und wissenschaftlichem Interesse zu wissen, wie die Verwendung solcher Technologien das Verhalten der betroffenen Akteure beeinflusst.
2021 to 2024
Deutsche Forschungsgemeinschaft (DFG)
Dynamic modelling of training-induced, response-optimised mobilisation of neural resources
This projects tests if neural resource mobilisation can be optimized by adapting the task demands relative to the subject’s current ability in healthy older participants. We refer to the gap between task demand and ability as the Ability Prediction Error (APE). Using computational modelling and longitudinal quantitative MRI (qMRI), we aim to explore how APEs control sensorimotor performance improvements, behavioural transfer and the time course of neural resource mobilization at macro- and mesoscopic brain levels in a defined (pre-) frontal brain circuit.
2020 to 2024
Deutsche Forschungsgemeinschaft (DFG)
Effects of hippocampal vascularization patterns on the neural resources of MTL neurocognitive circuits
The hippocampus and adjacent entorhinal cortex (EC) form a neural circuit within the medial temporal lobe (MTL) that is crucial for episodic memory formation. Integrity of this circuit is massively affected by age-related degeneration, partly due to pathology (e.g. tau, microinfarcts), partly due to environmental factors. Interestingly, the pattern of hippocampal vascularization varies among individuals, that is, there are individuals with a single supply, and there are individuals with a double supply., We recently found out that the individual vascularization profile interacts with verbal memory and global cognition: participants with a double supply had higher scores in the California Verbal Learning Test (CVLTII). What is not clear so far is which neuronal mechanisms underlie this effect. How does the individual vascularization profile affect cognitive aging? How does a double supply contribute to cognitive resource, and does it interact with training success?, These are the key questions addressed in this project within the CRC 1436. Here, we use the beneficial effect of a double hippocampal blood supply as model to understand the neuronal basis of cognitive resources in younger and older adults. By using ultra-high resolution functional and structural imaging at 7 Tesla together with advanced modeling techniques, we will investigate how the fine-grained hippocampal vascular supply affects age-related MTL pathology, MTL integrity, and MTL myeloarchitecture (neural resources), and how this mediates subregion-specific memory function (cognition). Finally, we will test how the effect of cognitive interventions on MTL function is modified by the hippocampal vascularization patterns.
2022 to 2024
Deutsche Forschungsgemeinschaft (DFG)
A hybrid sea ice model to estimate the impact of floe scale sea ice-ocean-atmosphere coupling on the Antarctic sea ice evolution
A number of mechanisms have been proposed to explain the decrease and increase of the Antarctic sea ice extent in the recent years. But the processes that drive this evolution are not well understood. The simulation of Antarctic sea ice in current climate models remains a fundamental problem and the reason for this shortcoming is a current research question. But there is some evidence that this stems, in addition to the formulation of atmospheric and oceanic processes, also from the description of the sea ice physics in the Southern Ocean. Even though much of the current sea ice cover in the Southern Ocean resembles a marginal ice zone, continuum sea ice models usually do not resolve sea ice floes nor parameterize this regime and neglect important feedbacks on climate and weather. Furthermore, the application of continuum sea ice models at or below the resolution of individual floes is questionable as the underlying continuum assumption of those sea ice models likely breaks down. In this proposal we will address these shortcomings of current continuum sea ice models used in climate models by developing a hybrid sea ice model, that explicitly describes atmosphere, sea ice and ocean interactions up to the floe scale. The hybrid approach provides a seamless model framework to predict the sea ice state, ranging from interacting sea ice floes in the marginal ice zone up to pack ice. The development of new numerical models and their validation to improve the understanding of Polar Processes and Mechanisms is a central aspect of the current call. Our hybrid model, which combines particle with continuum methods, will contribute to a better understanding and prediction of the Antarctic climate system by explicitly including coupling and feedbacks between atmosphere, sea ice and ocean at the floe scale. Small scale processes related to individual floes are important to the polar climate, but their parameterization in continuum sea ice models remains a research question.To understand the impact of floe scale interactions on the evolution of the sea ice cover in the Southern Ocean, we will develop a Discrete Element sea ice model, based on the description of DESIgn and the Princeton DEM, and nest it into the continuum sea ice formulation in the climate model ICON. Our goal is to explicitly simulate discrete sea ice floes in a subdomain of interest such as the marginal ice zone. In regions where a high spatial resolution is not required, the simulation is based on the continuum model, which is a suitable, computational efficient, approach to describe the sea ice evolution at large scales and low resolutions. Using the hybrid approach, we will explicitly take the floe size distribution into account, which significantly impacts the simulated sea ice volume. Finally, owing to the particle approach used in the hybrid sea ice model, this project opens a pathway towards exascale sea ice modeling, including the possible use of GPUs.
2020 to 2024
Deutsche Forschungsgemeinschaft (DFG)
Creation and analysis of a biomarker-based age cohort
As we age, our mental capacity and memory decline. However, the severity of this decline varies greatly between different people. A rapid decline in memory can also be an early sign of Alzheimer's disease, in which proteins are deposited in the brain and restrict the function of nerve cells. The aim of the central project Z03 is to better understand healthy cognitive ageing using various imaging techniques. In a large cohort of cognitively healthy elderly subjects, we want to investigate the molecular, functional and structural properties of the brain in old age. For this purpose, we are recruiting subjects aged 60 years and older over a period of 4 years. One focus of our study is on the group of super-agers, who are at least 80 years old and have above-average cognitive performance (for their age), and all subjects undergo a 3 Tesla MRI examination to investigate brain structure and function. Some of the test subjects will also be further examined for tau deposits using PET. In addition, various proteins, including Alzheimer's-associated proteins, are examined in the blood. Furthermore, the test subjects will be further examined in other subprojects of the CRC, which include cognitive training interventions, for example., This text was translated with DeepL
2021 to 2024
Deutsche Forschungsgemeinschaft (DFG)
Exploratory attentional resource allocation by the anterior prefrontal cort
Allocation of attention enables us to focus on the task at hand. However, in a constantly changing environment it is also necessary to explore the environment for the adaptive reallocation of resources. The anterior prefrontal cortex (aPFC) is regarded as a decisive part of a neurocognitive circuit for the neuronal realization of exploratory resource allocation in human and non-human primates. However, rodents (with their less differentiated frontal cortex) also show exploratory resource allocation. We plan to investigate the neural processes of exploratory attentional resource shifts on the macro-scale and meso-scale across humans and Mongolian gerbils. We utilize a novel, complementary foraging paradigm in both species based on exploitation / exploration trade-offs and record brain activity from the aPFC with respect to its local micro- and widespread macro-circuitry. Moreover, there is emerging evidence that exploratory attention is diminished in old age revealed by-sometimes perseverative- exploitative behaviour. Exploratory resource allocation is also likely to be a prerequisite for successful transfer of learning. This will be investigated in collaboration with other subprojects of the CRC.
2021 to 2024
Deutsche Forschungsgemeinschaft (DFG)
A Coupled Peridynamic-Finite-Element-Simulation for the Damage Analysis of Fibre Reinforced Composits
The prediction of damage behaviour and residual strength as part of a damage tolerance assessment is crucial for the design, evaluation and approval of safety-relevant lightweight structures. For fibre-reinforced composites (FRP), sufficiently precise and robust methods for evaluating progressive damage have been lacking to date. The main challenge for analysing FRP structures in comparison to metallic materials is the heterogeneity of FRPs, which leads to complex failure mechanisms. A simulation methodology for strength assessment must therefore be able to depict both the initiation and progression of damage, including all the mechanisms at work and their interaction., The aim of the DFG project is to develop an improved damage analysis methodology for FRP. For this purpose, a new adaptive solution approach is proposed, which consists of a coupling of the peridynamics (PD) for potentially damaged model areas with the FEM for the undamaged areas. The aim of the project is to increase the prediction accuracy of the load-bearing behaviour and thus to develop more robust, safe and resource-efficient structures., PD is a promising non-local method for describing damage and dynamic crack growth, especially in brittle materials. However, the computational effort is extremely high in order to achieve a sufficiently accurate description of the crack behaviour. In order to reduce the computational effort, peridynamics is only used in those parts of a structure in which cracks can potentially occur. The remaining structural areas are modelled using the classical finite element method (FEM). In the project, suitable methods for coupling the PD with the FEM are developed, tested and evaluated and used for crack propagation. Initial good results were achieved with the Arlequin Method, the Alternating Schwarz Method and the Splice Method. The Splice Method has provided the best test results and is characterised by comparatively simple coupling equations. The software developed in the project will be made freely available (open source software) in accordance with the DFG goal of "sustainability of research software" as part of the "e-Research Technologies" funding programme in order to enable further use by other researchers.
2020 to 2024
Deutsche Forschungsgemeinschaft (DFG)
Hybrid^2-Index Structures for Main Memory Databases
Aim of this project is to speed up index accesses of database management systems (DBMS) in order to improve the total performance. As index accesses are starting points for all succeeding processing steps of database queries, fast index accesses are the key to a superior total performance of DBMS. For the purpose of speeding up index accesses we propose to investigate and develop new hardware-/software index structures, which realize structure-hybrid indexes, i.e., the combination of static and dynamic indexes, on hybrid shared-memory system architectures consisting of a CPU and an FPGA or GPU as hardware accelerator. Such hybrid^2-indexes are not considered so far in literature, such that the possibilities of current hybrid shared-memory system architectures are not utilized in an optimal way. Because of the reduction of the communication costs between CPU and hardware accelerator many existing design rules for utilizing hardware accelerators must be rethought, especially concerning the complexities of tasks taken over by the hardware accelerators.Within this project we will hence research on which and how static and dynamic index structures can be realized in an efficient way with high performance on hybrid systems. Furthermore, we will investigate how to react on changing access patterns by dynamically swapping used index structures on the hardware accelerators. We expect novel, adaptive structure- and hardware-hybrid index structures, which significantly improve the performance of index accesses in DBMS in comparison to existing traditional systems.
2020 to 2024
Deutsche Forschungsgemeinschaft (DFG)
Kriechverhalten von gerichtet solidified Mo-Werkstoffen mit und ohne Beschichtung; High temperature mechanical behavior of advanced directionally solidified multi-phase Mo-alloys
As part of the DFG joint project launched in 2020, complex, multifunctional oxidation protection coating systems were developed for the material protection of molybdenum (Mo)-containing refractory metal alloys. Such alloys exhibit higher thermal stability than the nickel-based superalloys previously used as turbine materials. With sufficient long-term stability, they could therefore be operated in turbine applications at temperatures 150 K higher, which would result in an increase in turbine efficiency. However, the oxidation of Mo and the evaporation as Mo oxide are proving to be a problem, which inevitably leads to the mechanical disintegration of a corresponding component and requires protective coatings of a few tens to a few hundred micrometers thick, preferably with a self-healing function to prevent cracking in the coating., Such a coating system, consisting of a so-called preceramic polymer - an oligomeric chemical compound that can be converted into a ceramic by heat treatment -, particulate fillers such as silicon, boron and hexagonal boron nitride, was tested in long-term oxidation experiments and shows promising properties on selected Mo-containing alloys., As the layer thicknesses cannot be extended indefinitely, a supplementary application was submitted to the above-mentioned application in order to combine the coating process based on filled preceramic polymers with the so-called, pack cementation, process - a coating process in which protective components such as boron and silicon are applied from the powder bed using transport agents via diffusion processes in the gas phase - and thus a) to further increase the layer thicknesses and b) the effectiveness of the protective layers obtained. Initial results are promising and show that it is possible to combine both processes to produce oxidation protection coatings with thicknesses of more than one hundred micrometers. The work on combining both processes is being systematically investigated as part of a Walter Benjamin Research Fellowship funded by the DFG., This text was translated with DeepL
2021 to 2024
Deutsche Forschungsgemeinschaft (DFG)
Laser-based additive manufacturing of metal parts from powder in microgravity - LMD@µg
Fixed base stations are to be set up on the moon and on Mars in the near future. Accordingly, the duration and number of space missions will continue to increase in the long term. At the same time, the probability of component failures increases during the flight. In order to be able to react quickly in such a case, a process must be developed where parts can be manufactured or repaired, so that the total mass of spare parts on the spaceship can also be reduced to a minimum., The project is implemented through the development of a laser-based additive manufacturing process for the production of metal parts from powder (titanium and nickel alloys) in microgravity in a pressurized volume. The approach is based on the "Laser Metal Deposition" (LMD) process known for earth gravity. The aims of the research project are the development of a reliable powder handling technology, an LMD device and the guarantee of a stable melting process. The production of microgravity is done with the help of the Einstein-Elevator., The project is being carried out by the Institute of Transport and Automation Technology (ITA) at Leibniz University Hannover in cooperation with the Institute für Logistics and Material Handling Systems (ILM) at Otto-von-Guericke University in Magdeburg.
2021 to 2024
Deutsche Forschungsgemeinschaft (DFG)
Meso-scale Bildgebung am Menschen
Dieses Projekt bildet das Z-Projekt des SFB 1436 "Neural Resources of Cognition". Das Ziel dieses Projektes ist es, Methoden zur meso-scale Modellierung von ultra-hochfeld MRT-Daten zu entwickeln um neuronal Ressourcen in jungen und älteren Menschen zu identifizieren. Ich leite dieses Projekt zusammen mit Prof. Oliver Speck and Prof. Michael Hanke.
2021 to 2024
Deutsche Forschungsgemeinschaft (DFG)
"Metabolische Dysregulationen bei EMT-getriebener metastatischer Kolonisierung"
Die metastatische Kolonisierung erfordert eine dynamische Adaptation von Tumorzellen and sich permanent ändernde Bedingungen der Tumorumgebung. Dies wird durch die Aktivierung des embryonalen Programmes der epithelialen-mesenchymalen Transition (EMT) ermöglicht, welche Tumorzellen die notwendige Plastizität verleiht. Wir und andere Arbeitsgruppen haben gezeigt, dass diese Plastizität auch die permanente Adaptation metabolischer Prozesse einschließt. In Projekt A03 werden wir untersuchen, wie die EMT-Aktivierung mit metabolischen Veränderungen in der metastatischen Kolonisierung verknüpft ist, mit dem Ziel molekulare "Schwachstellen" als neue therapeutische Angriffspunkte zu identifizieren. Wir werden charakterisieren, wie EMT-Faktoren metabolische Prozesse (z.B. den Wechsel in zentralen Energie-Signalwegen) regulieren, neue Wege eines gezielten Eingreifens erforschen und die Ergebnisse an humanen Krebserkrankungen validieren.
2019 to 2024
Deutsche Forschungsgemeinschaft (DFG)
"Metabolische und dietäre Kontrolle von mesenchymalem Gewebspriming und chronischer Arthritis"
Zelluläre und systemische Änderungen des Stoffwechsels haben dramatische Auswirkungen auf die Immunantwort und auf die Entstehung und den Ablauf von rheumatoider Arthritis (RA). In der ersten Förderperiode der FOR2886 haben wir gezeigt, dass metabolische Aktivierung synovialer Fibroblasten (SF) die Schwere und Länge von wiederholt auftretenden Artrhritisschüben erhöht ("entzündliches Gewebspriming"). Unsere Vorarbeiten für die zweite Förderperiode weisen darauf hin, dass Ernährungsumstellungen, wie zum Beispiel Nahrungsergänzung mit kurzkettigen Fettsäuren oder Intervallfasten (IF), in Mäusen die Entwicklung von entzündlichem Gewebspriming unterdrücken. IF bewirkte in unseren präliminären Versuchen substantielle Änderungen sowohl des Serum-Metaboloms als auch der bioenergetisch-transkriptionellen Signatur von SF. Außerdem resultierte IF in signifikanten Änderungen der Zusammensetzung der Darmmikrobiota. Während der zweiten Förderperiode planen wir daher, die direkten und indirekten Mechanismen zu entschlüsseln, die dieser Neustrukturierung des systemischen und zellulären Stoffwechsels durch IF zugrunde liegen und die letztendlich die Abmilderung von Arthritis begünstigen. Längerfristig ist es unsere Vision, eine Diät zu entwickeln, die die Entstehung von Arthritis und das entzündliche Gewebspriming in präklinischen Mausmodellen vermindert. Die aus diesen Versuchen gewonnene Erkenntnisse wollen wir dann auf Patienten mit RA und anderen Formen entzündlicher Gelenkserkrankungen übertragen
2024 to 2024
Deutsche Forschungsgemeinschaft (DFG)
Netzwerke, Paradigmen und Karrieren im akademischen Feld
Das von der Deutschen Forschungsgemeinschaft finanzierte Projekt untersucht den Wandel der Logik akademischer Felder von einem Wettbewerb um Erkenntnisgewinn hin zu einem Wettbewerb um Drittmittel und Sichtbarkeit. Insbesondere drei Aspekte sind dabei von Interesse: die Verengung der paradigmatischen Vielfalt in einem akademischen Feld, die sich verändernden Kooperationsmuster der Wissenschaftler:innen sowie der Wandel und die zunehmende Standardisierung wissenschaftlicher Karriereverläufe. Das Projekt untersucht diese Entwicklungen für das Feld der Soziologie in einer komparativen empirischen Studie, in der für den Zeitraum 2000 bis 2019 die Veränderungen der US-amerikanischen und der deutschen Soziologie im Vergleich analysiert werden. Um unsere forschungsleitenden Hypothesen zu prüfen, sowie Hypothesen zu generieren, die sich auf die Untersuchung des Wandels des akademischen Feldes auf den Ebenen von Ländern, Institutionen und Forschenden beziehen, kombinieren wir unterschiedliche Datentypen: Publikationsdaten (z.B. Artikelabstracts auf SCOPUS), Netzwerkdaten (Kooperationen, z.B. Koautorenschaft und Zitationen zwischen Forscher:innen, Berufungsdaten), Lebenslaufdaten, institutionelle Daten (z.B. finanzielle Ausstattung der Fachbereiche) und in qualitativer Befragung von Soziolog:innen generierte Interviewdaten, die Einsichten in die persönlichen Erfahrung des angenommenen Wandels eröffnen sollen. Für die Auswertung dieser Daten werden Methoden der geometrischen Datenanalyse, der Netzwerkanalyse, der quantitativen Textanalyse, der Sequenzanalyse und der qualitativ-rekonstruktiven Sozialforschung genutzt.
2021 to 2024
Deutsche Forschungsgemeinschaft (DFG)
Olfaktorisch-limbische Verbindung: vom Geruch zum Verhalten...
Soziale Verhaltensweisen, konfliktiv (z.B. Aggression, Kindstötung) oder kooperativ (z.B. Paarung, Mutter-Kind Interaktionen), können bei allen sich sexuell fortpflanzenden Tierarten beobachtet werden und sind entscheidend für Gesundheit, Überleben und Reproduktion. Diese Verhaltensweisen sind vielfach instinktiv und werden ohne vorherige Exposition allein in Gegenwart von spezifischen sensorischen Reizen, die oft olfaktorischer oder Pheromon-artiger Natur sind, gezeigt. Über die neuronalen Schaltkreise, die diese Verhaltensweisen codieren, ist jedoch wenig bekannt. In diesem Projekt sollen die molekularen, zellulären und neuronalen Grundlagen olfaktorisch vermittelter sozialer Verhaltensweisen untersucht werden – ausgehend von einer Charakterisierung der neuronalen Schaltkreise bis hin zur Verhaltensrelevanz. Unser Ziel ist es zu bestimmen, wie soziale Signale zuerst im olfaktorischen Bulbus umgewandelt und im Anschluss an limbische Systeme, die für soziales Verhalten wichtig sind, weitergeleitet werden. Des Weiteren wollen wir untersuchen, wie spezielle Neurone im limbischen System, die den Neurotransmitter GABA und das Enzym Aromatase exprimieren, diese Signale verarbeiten sowie die sozialen Verhaltensweisen identifizieren, die zu ihrer Aktivierung führen. Wir werden einen vielseitigen Ansatz verwenden, der in vivo Zwei-Photonen- und mikroendoskopische Aufzeichnungen, eine selektive Markierung von neuronalen Schaltkreisen, Gentargeting sowie Verhaltenstests kombiniert, um die anatomischen und physiologischen Eigenschaften von olfaktorischen Netzwerken aufzuklären, die der Steuerung von sozialem Verhalten zugrunde liegen. Soziale Verhaltensweisen sind meist stereotyp und eine festprogrammierte Verschaltung während der Entwicklung ermöglicht ihre Charakterisierung anhand von molekulargenetischen Ansätzen. Wir werden drei spezifische Ziele verfolgen, die unabhängig, aber miteinander verbunden sind. Zu Beginn werden wir, unter Verwendung von viralen Tracern, die Neuronen Populationen des olfaktorischen Bulbus identifizieren, die auf GABAerge und Aromatase exprimierende Neuronen in der medialen Amygdala und im BNST (bed nucleus of the stria terminalis) projizieren sowie die molekulare Identität dieser Neurone untersuchen. In einem zweiten Schritt werden wir, mithilfe der in vivo Kalzium-Bildgebung, diese Neurone des olfaktorischen Bulbus auf die molekulare Bandbreite ihrer Antworten auf Chemosignale, die spezifisches soziales Verhalten codieren, untersuchen. Anschließend wird die Aktivität von GABA- und Aromatase positiven Neuronen in der Amygdala und im BNST in unterschiedlichen sozialen Verhaltensweisen funktional charakterisiert. Diese detaillierte Studie der neuronalen Schaltkreise, die gut definierte, angeborene soziale Verhaltensweisen steuern, wird einen wichtigen Schritt zum Verständnis der Codierung komplexer Verhaltensweisen durch das Gehirn liefern.
2022 to 2024
Deutsche Forschungsgemeinschaft (DFG)
Planar and Vertical Junctions for Innovative GaN-Based High-Power Devices
The development of group III nitrides has started a new era of high-frequency and high-power electronics. With the surge in regenerative energy sources, electric vehicles, data centres and many more mobile and energy-hungry applications, more efficient, compact and economical power conversion systems are required. In this context, a superior Baliga Figure of Merit is one factor, which promises significant potential for GaN-based power electronics (PE).Its workhorse is the lateral AlGaN/GaN HFET, which has reached commercial maturity in the 600 V regime. Generally, the vertical device geometry is preferred due to significant scaling benefits (as the maximum operating voltage can be scaled without compromising wafer area) and improved isolation properties. Electric field peaks are buried in the bulk, rendering vertical devices less prone to surface-related breakdown and parasitic effects like current collapse. Vertical power devices rely on specific types of 3D field-shaping and current-guiding (hetero)structures to ensure low leakage currents and high breakdown voltages. However, the failure of dopant implantation and diffusion processes in GaN leaves selected-area growth (SAG) as the most viable option. SAG has already yielded promising results, but a still relatively immature state is preventing the commercialization of vertical PE devices based on GaN. Material issues, especially linked to defects and non-ideal interfaces, are far from being solved. In addition to the high cost of native GaN substrates, a lack of knowledge of microstructure and defect characteristics and immature fabrication processes have prevented the development of a viable vertical GaN device technology.In this project, a systematic analysis of growth- and process-related defects and microscopic properties of p-n junctions and heterojunctions will be conducted. Compound Semiconductor Technology (CST) of RWTH Aachen University will employ SAG processes to create planar and vertical p-n junctions and heterojunctions in specific test structures for electrical and microscopic characterization. The Semiconductor Physics group at OvGU Magdeburg will perform detailed micro- and nanoscopic studies via (scanning) transmission electron microscopy ((S)TEM), cathodoluminescence (STEM-CL) spectroscopy, electron beam induced current (STEM-EBIC) measurements as well as time-of-flight transport analysis to identify defects, characterize carrier and exciton transport/dynamics and link these to electrical data and growth/processing conditions. This, complemented by physical modelling, will generate a deep understanding of the impact of defects and processes on the macroscopic material, interface and device properties and lead to novel strategies to fabricate PE devices. Finally, improved junction barrier Schottky diodes (JBS), vertical-channel junction field effect transistors (vc-JFET) or current aperture vertical electron transistors (CAVET) will be demonstrated.
2020 to 2024
Deutsche Forschungsgemeinschaft (DFG)
Restoring neural resources perturbed by sleep deprivation
Many disorders as well as ageing cause a decline in cognitive functions, yet experimentally inducible, changes in neural resources are required to understand how these declines arise and how they are, counteracted by mechanisms mobilising remaining resources. Lack of sleep destabilises and impairs, cognitive performance and renders mistakes more likely, presumably by functionally depleting neural, resources. In this project we aim to establish and characterise sleep deprivation (SD) as a model to, test and simulate the effects of declining cognitive functions as a result of reduced availability of neural resources (a "functional loss of resources”) in humans. On the other hand, cognitive control may adaptively mobilise resources according to needs and availability. To probe neural resources and mechanisms maintaining cognitive functions in spite of SD effects, cognitive control is investigated using a task allowing us to disentangle contributions of the posterior medial frontal, lateral frontal, and occipital cortices which together form a neural network that facilitates behavioural adaptations. Employing model-based and multivariate pattern analyses (MVPA) to neuroimaging data in rested wakefulness (RW) and after SD, the contributions of individual regions and the network itself will be investigated. Structural predictors of resource vs. vulnerability to SD, such as intracortical myelination, will be explored using microstructural MRI. Orexin (OX) is a neuropeptide that, in interaction with the noradrenergic (NA) system, stabilises and adjusts arousal and may have the potential to revert SD effects. Therefore, its role of in stabilising and restoring neural resources will be studied in pharmacological challenge studies.
2021 to 2024
Deutsche Forschungsgemeinschaft (DFG)
SBF 1436/1 - A07 "Molecular & cellular determinants of neural resources - Orexinergic modulation of neural resource"
Orexinergic neurons are potent mediators of circadian fluctuation in cognitive function. In the proposed, project, we aim to explore the potential of orexinergic neuromodulation and the associated wakefulness, promoting system to mobilise neural resources by stimulating prefrontal cortex (PFC)-tohippocampus, signalling and to build up resources through increasing neural plasticity in the hippocampus., We will impose circadian disturbances together with pharmacological and viral interventions, to dissect the circuit mechanisms that underlie the circadian neuromodulation of memory formation, pattern recognition and cognitive flexibility. Engram labelling, slice physiology and molecular analysis, will be utilised to determine the cellular mechanisms of resource formation within hippocampal microcircuits., Our project will closely connect with other CRC projects that target cellular and circuit mechanism, of resource management and ultimately aims to investigate the potential of orexinergic modulation, for the mobilisation of cognitive reserve beyond circadian modulation. Thus, the interactive approach, within the CRC will provide fundamental insights into neuronal circuits and cellular mechanism, that may be utilised to battle cognitive decline, e.g. during ageing
2021 to 2024
Deutsche Forschungsgemeinschaft (DFG)
SBF 1436/1 - A07 Orexinergic modulation of neural resource
In the proposed project, we aim to explore the potential of orexinergic neuromodulation and the associated wakefulness promoting system to mobilize neural resources by stimulating prefrontal cortex (PFC)-to hippocampus signaling and to build up resources through increasing neural plasticity in the hippocampus. To dissect the underlying neuronal mechanisms, we will use behavioral, pharmacological and viral interventions. In close connection to other CRC projects we expect to gain insight in to the neuronal circuits and cellular mechanism that may be utilized to battle cognitive decline.
2021 to 2024
Deutsche Forschungsgemeinschaft (DFG)
SFB 1436/1 - TP MGK / IRTG
We provide a platform for the structured interdisciplinary scientific training of our doctoral as well as postdoctoral researchers within the proposed CRC to meet both individual career needs but also the transfer of knowledge form basic science into application, and the involvement of the public in research questions.
2021 to 2024
Deutsche Forschungsgemeinschaft (DFG)
SFB 1436/1 - Z01 "Functional neural circuit analysis and small animal imaging in vivo"
Neurobiological studies of memory over the past century have progressed along two relatively independent lines of inquiry: (1) a top-down approach that examines the animal’s behaviours associated with memory acquisition, consolidation, and retrieval as well as the brain regions and circuits underlying these processes, and (2) a bottom-up approach that explores the cellular and circuit mechanisms of memory encoding and storage by examining the patterns of neuronal firing and the efficacy of synaptic transmission. Project Z01 will integrate these approaches, bridge micro- meso- and macroscale analyses, and provide most recent technology for functional neural circuit analysis to several projects conducting animal experiments within this CRC.
2021 to 2024
Deutsche Forschungsgemeinschaft (DFG)
SFB 1436: Neural Resources of Cognition - Unlocking the Full Potential of the Brain. TP A06: Neural resource mediated by BDNF-dependent neuroplasticity of cortico-hippocampal interactions
Neuronal interactions between the hippocampus (HIP) and prefrontal cortex (PFC) mediate essential, cognitive brain functions including spatial learning and fear extinction. This project will study how performancedeficits due to pathophysiological or ageing-dependent malfunction in one of the two brain, areas can be ameliorated by BDNF release-dependent compensatory re-shaping of HIP-PFC synaptic, circuits. We hypothesise that the HIP-PFC synaptic circuit provides a platform to serve as a neural, resource that can be tuned by BDNF-dependent mechanisms and exploited as a neural reserve during, age- or disease-related malfunctioning. To test this, we will employ optogenetically controlled BDNF, release in separate experiments in HIP and PFC neurons, respectively, and investigate in a combined, in vivo and ex vivo approach (1) the mechanisms of HIP-PFC neuronal interactions that provide the, compensatory neural reserve/resource and (2) how unlocking this resource can improve cognitive, functions in adult, healthy, aged, and diseased mice.
2021 to 2024
Deutsche Forschungsgemeinschaft (DFG)
SFB 1436 "Neuronal Resources of Cognition"; Project B6 "Mobilisation of neural resources for temporal attention"
The external environment is rich with multiple sources of sensory stimulation, and our ability to adapt, to our surroundings requires the efficient use of neural resources to process this dynamic input. Attendingto particular moments in time is a key cognitive capacity instrumental in all animals’ survival., This requires associations between sensory systems and top-down executive control. How our senses, give us information about the environment changes as we age, often becoming compromised, and, resulting in drastic lifestyle changes, including problems with communicating and learning; ultimately, leading to isolation and further cognitive decline. While previous designs to prolong cognitive functioningacross the lifespan often rely on unisensory training programs, in the ‘real’ world, events often stimulate more than one sensory modality simultaneously and, therefore, may enhance the efficacy ofresource utilisation. The hidden potential underlying multisensory information processing within theseneurocognitive circuits during temporal attention, as well as the changes in these capacities acrossageing, remain unclear. Our project focuses on a key component that is instrumental in cognitive performanceand memory formation, the utilisation of temporal information in multisensory contexts; further, we will determine the potential to enhance these cognitive processes through interventionssuch as external feedback and multisensory training. We evaluate the potential for elevating cognitiveefficiency by manipulating expectations about the timing of sensorially cued events (WP1), testing thetransfer of information across modalities (WP2), and combining sensory categories (WP3) to ultimatelystabilise memory engrams. Across all three aims, we will relate behavioural readouts directly with neuronalactivity on the meso-scale and macro-scale level using functional magnetic resonance imaging(fMRI) in both humans and mice as well as micro-scale single-cell resolution two-photon (2P) Ca2+imaging and immediate early gene (IEG) expression in mice.
2021 to 2024
Deutsche Forschungsgemeinschaft (DFG)
C05 "Intervening in circuits for cognitive resource allocation in primates"
SFB 1436 aims to investigate neural resources at all size scales through an interdisciplinary approach that relates functional and structural properties of cortical and subcortical circuits to behaviour and performance and investigates interventions. Technological advances in in vivo brain imaging of the human brain and multimodal modelling will build a bridge between molecular studies in animal models and behavioural studies in subjects and patients., Project C05 of SFB 1436 - in collaboration with Prof. Dr. Petra Ritter (Charite, Berlin) - takes a combined theoretical and empirical approach to investigate causally - from neurons to behaviour - how resource allocation in visual and parietal brain regions can be controlled by altering functional connectivity in the animal model closest to human cognition, the rhesus monkey.
2019 to 2024
Deutsche Forschungsgemeinschaft (DFG)
Simulation and analysis for temporal multiscale problems with partial differential equations
In this project, we investigate temporal multi-scale problems with partial differential equations. Many applications describe long-term effects, such as material aging, material damage due to cracks, biological pattern formation processes or biological growth processes. These phenomena are often determined by important short-term influences., A detailed numerical simulation of such processes with established methods is not possible. As an example, we consider the growth of artheriosclerotic plaque, which takes place over a period of several months, but is significantly determined by the mechanical stress of the pulsating blood flow, which requires a resolution of less than one second. A direct simulation over long periods of time with very fine resolution is beyond the possibilities., We will develop, investigate and implement temporal multi-scale methods to approximate these problems. These methods are based on averaging the fast processes in order to obtain an effective equation to describe the long-term behavior., One part of the project is dedicated to the mathematical analysis of temporal multi-scale problems with partial differential equations. Usually, a scale parameter describing the ratio between slow and fast scale can be introduced. We will investigate the convergence of the multiscale solution to the averaged solution with respect to this scale parameter., In the second part, efficient numerical methods for the fast approximation of temporal multi-scale problems are developed and implemented. These methods are based on an efficient approximation of the averaged long-time problems. For local discretization we use the finite element method, temporal discretization is based on Galerkin methods. To achieve efficient algorithms, we will consistently rely on adaptive methods in space and time., The mathematical analysis of temporal multi-scale in the context of partial differential equations is a challenging problem that has hardly been systematically investigated so far., This text was translated with DeepL
2020 to 2024
Deutsche Forschungsgemeinschaft (DFG)
Strengthening the link between subjective and objective visual acuity
Visual acuity testing is a fundamental ophthalmological examination with eminent relevance for diagnostics, medico-legal decisions, and research progress in clinical and basic science. Importantly, the standard procedure to determine visual acuity is ‘subjective’ testing, where the validity of the results critically depends on the reliability of the patient’s responses. In certain groups of patients this is, due to inability or lack of willingness, a serious confound with far reaching consequences. While ‘objective’ visual acuity testing based on visual evoked potentials (VEPs) has proven to be of value, it is suffering from severe limitations that compromise the reliability of the VEP-acuity estimates. Our recent research advances indicate that these challenges can be overcome with an acuity-testing approach that is based on the cognitive event-related-potential component ‘P300’. Based on the momentum of this research, the current proposal aims to improve objective acuity testing in order to stimulate the wide-spread use of electrophysiological visual acuity estimation., We will address the challenges and limitations of conventional objective acuity testing with a bicentric approach combining bi-modal neuro-imaging [P300/VEP and magnetic resonance imaging (MRI & fMRI)] and psychophysics with the goal to devise an innovative objective acuity-testing scheme. Specifically, we plan to test 250 patients with visual impairment down to legal blindness. We will assess discrepancies between subjective and P300- and VEP-based acuity caused by (i) disease-type, (ii) spatial stimulus characteristics, (iii) cortical constraints, and (iv) temporal dynamics. We will use these insights to (v) establish an integrated framework for beyond-state-of-the-art electrophysiological acuity assessment in clinical and research applications. The aspects addressed will include effects of the interplay of central visual loss and fixation behavior, distorted vision, inherent differences in self-paced psychophysics vs non-self-paced objective readouts, and the scope of cognitive event related potentials and fMRI- based visual field acuity maps. This will advance both the application and our basic understanding of objective acuity testing., With the overarching goal to substantially improve the robustness, reliability, and specificity of objective visual acuity estimates, the project has a strong focus on practical relevance, aiming at the translation of findings into clinical routine and the identification of biomarkers for therapy-success readout. Simultaneously, the experiments will shed light on important aspects of the structure-function interaction in the healthy and diseased human visual system.
2021 to 2024
Deutsche Forschungsgemeinschaft (DFG)
The NMDA receptor complex - a signalling hub at the origin of cognitive flex-ibility?
The NMDA receptor (NMDAR) is one of the most thoroughly investigated receptors in the mammalian brain. It plays an important role in learning and memory and NMDAR hypofunction or pharmacological NMDAR inhibition leads to impairments in cognitive flexibility. However, the mechanistic underpin-nings of its role for cognitive flexibility and consequently the possibilities to exploit, expand or mobi-lise neural resource associated with its function are rather poorly investigated and developed so far. Research has staggered here at least in part for two reasons, the lack of behavioural paradigms that are sophisticated and sensitive enough to unmask underlying behavioural processes and the lack of knowledge about the NMDAR signalling hub. This hub extends beyond the receptor complex itself and its interactome in the sense that endogenous modulators and eventually glial signalling components are part of it. The aim of our project is to unravel the contribution of the NMDAR signalling hub to cog-nitive flexibility. We will focus our analysis on subregions of the frontal cortex involved in cognitive flexibility. We will combine a sophisticated behavioural paradigm in mice (attentional set shifting) with state-of-the-art, highly sensitive proteome analyses deciphering molecular, cellular and network properties of cognitive flexibility. In particular, the effect of age, environmental and cognitive enrich-ment, and circadian strain on the NMDAR signalling hub will be assessed with the aim to identify key players in the different subregions of the frontal cortex. This will enable us to identify druggable targets and corresponding intervention strategies. Our hypothesis is that a specific modulation of those com-ponents of the NMDAR signalling hub that are associated - both on a group and individual level - with stronger cognitive flexibility can be used as a neural resource. Consequently, pharmacological inventions specifically targeting these components should efficiently improve impaired cognitive flexi-bility and thereby improve cognitive functioning in general.
2021 to 2024
Deutsche Forschungsgemeinschaft (DFG)
Ultrathin coating of fluidized particles by means of aerosol
Coated particles for various applications are usually produced by spraying solid-containing liquid on mechanically agitated or fluidized cores. Every spray droplet which is deposited on the surface of a core particle leaves behind a solid remnant after evaporation of the solvent or suspension liquid (preferably water). Each such deposit is a building block (BB) of the coating layer. However, spray droplets are quite large (typically 40 µm with two-fluid nozzles) in present technology, so that BBs are also large, resulting in coarse and thick coating. Radically thinner and finer resolved coating layers (down to the nanoscale) could be produced on fluidized particles by using aerosol (with droplet diameters around 1 µm or less) instead of common spray. Feasibility of the respective aerosol fluidized bed (AFB) coating process has recently been shown by a proof-of-principle experiment. On this basis, the present project aims at a thorough scientific investigation of the novel AFB process. This includes batch coating experiments with variation of operating parameters, materials, as well as aerosol generation and entrance conditions. The quality of coated particles is characterized thoroughly by scanning electron microscopy and various image analysis techniques in regard of intra-particle coating thickness distribution, inter-particle coating thickness distribution, average porosity, porosity distribution, and pore size distribution. Supported by such unique data, a stochastic (Monte Carlo) model is developed and parameterized to accurately simulate the buildup of coating layers on single particles and in the population of particles; Moreover, in the surface coverage period (possibly with island growth) and later on (in the coating layer growth period). Finally, measurements are conducted and a model is developed to predict solids yield of the process, which is equivalent to the efficiency of the fluidized bed in filtering aerosol droplets out of the gas flow.
2022 to 2024
Deutsche Forschungsgemeinschaft (DFG)
Stand-alone two-phase parahydrogen induced hyperpolarizer for ultra-low and high field MR (2P-PHIP)
Magnetic resonance (MR) plays a pivotal role in many fields of science, and to enhance its intrinsically low signal several hyperpolarization (HP) techniques were developed For instance, dissolution dynamic nuclear polarization (dDNP) is in a state of preclinical research. It requires low temperatures (~1 K), paramagnetic agents together with microwaves for HP, and the rapid dissolution in a suitable carrier. This makes dDNP technically challenging and essentially a one-shot technique.An alternative HP method is the exploitation of the intrinsic spin order of para hydrogen (pH2 - the spin singlet isomer of H2), which can be transferred to target molecules. pH2 induced polarization (PHIP) makes use of the hydrogenation of target molecules with pH2, whereas signal amplification by reversible exchange (SABRE) allows spin order transfer without the modification of target molecules and enables continuous HP. As pH2 generation is low cost, low instrumentation demands and pH2 can be stored for months, PHIP and SABRE are promising methods of HP for future clinical applications.The project 2P-PHIP aims to the development of a cost-efficient PHIP and SABRE-based stand-alone continuous flow hyperpolarization reactor for biochemistry and future in vivo biomedical applications. In contrast to commercially available dDNP, the reactor will be able to continuously deliver high purity hyperpolarized liquids enabling MR experiments with longer acquisition times and larger quantities. A novel two-phase pH2 induced HP technique with the catalyst retained in a fluorinated phase (or another hydrophobic phase) will be pursued as the most promising route. This approach will facilitate the extraction of hyperpolarized substrates with high purity needed for future in vivo applications. More traditional (single-phase) PHIP and SABRE implementations will also be possible with this polarizer. The stand-alone reactor can be used at ultra-low (µT-range) or high magnetic field (T-range) MR enabling unique features of both regimes. MR at high magnetic fields provide superior spectral resolution, whereas imaging at low magnetic fields is compatible with sensitive implants (i.e. pacemakers). The investigation of HP using non-traditional methods, the direct observation of the HP itself will be carried out using the most sensitive SQUID instrumentation available. As we ultimately aim to in vivo applications, proof-of-concept experiments on biological samples, such as cell cultures, blood or homogenized brain tissue will also be undertaken.The outcome of the 2P-PHIP project will be a multipurpose stand-alone pH2-based polarizer featuring high concentrations of highly polarized substrates with high tracer throughput for in vivo applications.
2021 to 2024
Deutsche Forschungsgemeinschaft (DFG)
Structure and dynamics of nematic phases with strong smectic fluctuations formed by bent-core mesogens
Mesophases with mesogens of non-cylindrical shapes exhibit remarkable complex structures and, in some phases, a very fast electro-optical response. Enhanced polar and smectic fluctuations, driven by steric interactions of bent mesogens, for instance, result in the formation of cluster phases with strong susceptibility to external fields. Such highly responsive materials have broad perspectives for applications. The shape of the mesogens can also be controlled by external stimuli such as light in photoisomerisable molecules. This proposal is based on the extensive collaboration between our group in Magdeburg and the Department of Organic Chemistry at Martin Luther University Halle (C. Tschierske and M. Alaasar). The proposal's primary aim is to investigate the effects of the photo-tuneable nanostructures on liquid crystals' micro and macroscopical properties in bulk and restricted geometry. We propose to study complex liquid crystalline systems such as photoswitchable mesogens forming nematic, twist-bend nematic phase, bent-core smectic phases with the heliconical nanostructure, and the newly discovered polar nematic phase. The central questions are how the nanostructure of the mesophase and photo-stimulation affect the bulk and surface properties of liquid crystals, how it affects the behaviour of colloids based on such materials. We will study the behaviour of liquid crystals in bulk, in droplets and filaments as well. The proposed research will be conducted in five stages, starting with the characterisation of the bulk properties and shifting the focus to the studies of light-driven anchoring transitions in pure photoswitchable compounds and systems with photoswitchable surfaces only. We will employ the acquired knowledge for understanding the behaviour of the solid inclusions in an LC matrix. The translational and rotational motions of colloidal particles will be investigated in the nematic, twist-bend nematic and ferroelectric nematic phases. At the final stage, we will explore the dynamics of liquid crystal filaments with photoismerisable mesogens. The output of this research will elucidate the mechanisms underlying the interplay between the light-driven mesogenic shape changes, structure formation and the properties of the novel liquid crystalline systems.
2021 to 2024
Deutsche Forschungsgemeinschaft (DFG)
Common and pleiotropic genetic factors in epileptogenesis
Previous studies on identifying genetic risk loci implicated in epileptogenesis have usually employed standard genetic risk models under which these variants act, namely single common variants under a multiplicative (i.e. additive in the number of alleles) model (GWAS studies) or several subsets of rare variants acting together as a genetic burden (exome studies). In the 1st funding period, we (1) identified 2 novel suceptibility loci for GGE (NCAM1, MAP3K9), (2) described an aberrant ALDH5A1 promoter regulation, and (3, formerly P2) conducted a benchmarking study for common-variant pleiotropy detection and applied such methodsto GWAS datasets from ILAE2. In the 2nd period, project P3 will pursue different statistical and bioinformatic approaches in parallel to identify epilepsy-related genetic variants that act under non-standard risk models or those which require additional information, including external epigenomic data or information on related traits, to achieve sufficient power for their successful identification. This involves widened pleiotropy detection, Bayesian GWAS, polygenic risk scores (PRS) profiling and improved epilepsy sub-phenotype delineation, systematic investigation of compound heterozygous risk models and of pairwise epistasis as well as several approaches based on integration of transcriptional and epigenetic data. We will focus on generalized genetic epilepsies (GGEs) while also considering focal epilepsies (FEs) as well as developmental and epileptic encephalopathies (DEEs). Project P3 will share novel candidate loci with P1, P2 and the experimental projects P4-P8.
2020 to 2023
Deutsche Forschungsgemeinschaft (DFG) // Land Sachsen-Anhalt
2-Photonen-Mikroskop für ex vivo Untersuchungen im Gewebeschnitt (Imaging / Elektrophysiologie)
Die 2-Photonen-Mikroskopie ist heute als modernes bildgebendesVerfahren für die Untersuchung zellulärer Funktionen imGewebeverband unentbehrlich geworden. Diese fortschrittliche mikroskopische Technik erlaubt aufgrund der geringeren Streuung des verwendeten langwelligen Anregungslichts im Infrarot-Bereicheine im Vergleich zur konventionellen Fluoreszenzmethoden erheblich größere Eindringtiefe. So können zelluläre Prozesse noch in einer Tiefe von ca. 150 µm in Schnittpräparaten visualisiert werden, deren Untersuchung für viele neurowissenschaftlich und immunologisch arbeitende Gruppen der Otto-von-Guericke-Universität essentiell ist. Obwohl in einer Reihe von AGs der Medizinischen Fakultät breites Interesse an solchen Experimenten in Gewebeschnitten besteht, existieren hier gegenwärtig nur 2-Photonen-Mikroskope, deren spezielle Konfigurationen auf Versuche mit lebenden Tierenzugeschnitten sind. Eine transiente Umrüstung dieser vorhandenen Geräte für Arbeiten in Gewebeschnitten wäre aufgrund langer Umrüstzeiten und dem damit verbundenen Arbeitsaufwand sehr ineffizient. Das beantragte 2-Photonen-Mikroskop soll deshalb als dedizierter Messplatz für Schnittpräparate dienen, wobei den Nutzern des Gerätes insbesondere auch simultane elektrophysiologische Ableitungen ermöglicht werden sollen. Das Gerät soll in die Serviceeinheit "Mehrdimensionale Mikroskopie und zelluläre Diagnostik" integriert werden, um es für alle Forschenden der OVGU Magdeburg nutzbar zu machen. Die Spezifikationen des Mikroskops sind so gewählt, dass anspruchsvolle "Live-Cell Imaging"-Experimente mit grünen und roten Fluorophoren mit hoher zeitlicher und räumlicher Auflösung durchgeführt werden können. Dazu soll das Gerät über zwei unabhängige Laserlinien (ein stimmbarer Laser und ein Festwellenlängen-Laser) verfügen, mit deren Hilfe die jeweils benutzen Fluorophore simultan nahe ihrer Absorptionsmaxima angeregt werden können. Die Ausstattung des Scan-Kopfes ist außerdem so gewählt, dass Linien, Areale und Volumenanteile des Präparates schnell und präzise abgetastet werden können. Die verbauten Detektoren sollen außerdem regelbar sein ("gated Photomultiplier"), so dass bei optogenetischer Stimulation mittels eines externen Lasers Beschädigungen durch massiven Lichteinfall ausgeschlossen werden können. Insgesamt soll durch die Beschaffung dieses modernen 2-Photonen-Mikroskops eine erfolgreiche Bearbeitung vieler DFG-geförderter Projekte am Standort direkt unterstützt werden.
2020 to 2023
Deutsche Forschungsgemeinschaft (DFG) // Land Sachsen-Anhalt
Creep behavior of directionally solidified Mo materials with and without coating
The work focuses on the development and characterization of novel multiphase high-temperature materials based on a Mo solid solution phase (Moss) reinforced with intermetallic Mo2ZrB2 and Mo2HfB2 phases with high melting points. Mo-Hf-B and Mo-Zr-B are a class of high-temperature materials that can find various applications, e.g. in the aircraft industry due to their high creep resistance at the targeted application temperatures, which is superior to modern nickel-based superalloys. However, the material behaviour in the medium temperature range is critical; here the molybdenum oxidizes, which makes material protection necessary., As part of a sub-project, self-healing coating systems are being developed, characterized and tested in an application-oriented manner. These coating systems consist of an oxygen-free preceramic polymer and oxygen-binding filler particles such as Si and B. The conversion into a closed ceramic protective layer takes place in an inert atmosphere in the temperature range between 800 °C and 1200 °C., Cyclic oxidation tests prove a protective effect (still to be improved) of the coating in the temperature range between 800 °C and 1000 °C; the effect at higher temperatures is currently being investigated., Initial results of radiographic investigations show that a zirconium molybdate phase is formed by adding ZrO2 as an additional filler, i.e. the alloy components Mo react to form stable phases and remain in the sample; the evaporation of Mo oxides is largely prevented. The role of the protective layer in this process has not yet been fully clarified and is the subject of further investigations., This text was translated with DeepL
2018 to 2022
Deutsche Forschungsgemeinschaft (DFG) // Land Sachsen-Anhalt
ADAPtive T cell migration into the stressed brain
The ADAP-SKAP55 proteins form a molecular complex that regulates adhesion and migration of T cells. Our findings from the 2nd funding period suggest a role of the two proteins in modulating membrane scaffolding and actin filament organization. We now plan to delineate their contribution to actin-mediated migration of T cells by structural, biochemical and molecular biology techniques. We will exploit our mechanistic insights to probe in mice the role of ADAP-SKAP55 as well as their interaction partners in stress-induced T cell extravasation into the brain meningeal space and clarify their relevance for T cell-supported cognitive functioning and coping with traumatic stress.Due to technical reasons only 200 projects can be displayed.
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