Research projects funded by the German Research Foundation

2018-2027
Mittelgeber: Deutsche Forschungsgemeinschaft (DFG)
Relevance of mast cells in maladaptation of the epidermal and endothelial, barrier during chronic skin inflammation
2021-2027
Mittelgeber: 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.
2017-2026
Mittelgeber: 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.
2023-2026
Mittelgeber: Deutsche Forschungsgemeinschaft (DFG)
An integrated semiconductor platform for the implementation and study of higher-order exceptional points
2022-2025
Mittelgeber: Deutsche Forschungsgemeinschaft (DFG)
Combination of a CD19 antibody of IgA isotype and CD47 inhibition for the treatment of BCP-ALL
2023-2025
Mittelgeber: 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.
2022-2025
Mittelgeber: 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.
2022-2025
Mittelgeber: Deutsche Forschungsgemeinschaft (DFG)
Continuum model with gas-liquid interfacial area for evaporation in porous media
2022-2025
Mittelgeber: 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.
2022-2025
Mittelgeber: Deutsche Forschungsgemeinschaft (DFG)
Rise, Fall, or Transformation of the Experience Society
2022-2025
Mittelgeber: Deutsche Forschungsgemeinschaft (DFG)
Rise, Fall or Transformation of the Experience Society?
2022-2025
Mittelgeber: 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.
2022-2025
Mittelgeber: 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.
2022-2025
Mittelgeber: 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.
2023-2025
Mittelgeber: 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.
2022-2025
Mittelgeber: 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.
2022-2025
Mittelgeber: 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.
2022-2025
Mittelgeber: 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.
2022-2025
Mittelgeber: 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.
2021-2024
Mittelgeber: 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.
2021-2024
Mittelgeber: 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.
2022-2024
Mittelgeber: 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.
2022-2024
Mittelgeber: Deutsche Forschungsgemeinschaft (DFG)
Oxide dispersion strengthened and oxidation resistant Vanadium alloys
2022-2024
Mittelgeber: 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.
2020-2024
Mittelgeber: 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.
2021-2024
Mittelgeber: 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.
2021-2024
Mittelgeber: 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.
2021-2024
Mittelgeber: Deutsche Forschungsgemeinschaft (DFG)
Neural Resources of Cognition - Unlocking the Full Cognitive Potential of the Brain
2021-2024
Mittelgeber: 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.
2021-2024
Mittelgeber: Deutsche Forschungsgemeinschaft (DFG)
SFB 1436/1 - TP MGK / IRTG
2022-2024
Mittelgeber: 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.
2021-2024
Mittelgeber: 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.
2021-2024
Mittelgeber: 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.
2021-2024
Mittelgeber: Deutsche Forschungsgemeinschaft (DFG)
NPY-mediated autophagy and the adaptation of hippocampal circuits to stress
Recent evidence suggests that Neuropeptide Y (NPY) is able to regulate neuronal autophagy both in vertebrates and invertebrates and that this might explain its capacity to modulate long-term cellular changes in neural circuitry. Complementary to a subproject of Syntophagy investigating non-cell autonomous metaplastic effects of NPY, we here focus on the role of NPY-induced autophagy in a local circuit relevant for stress adaptation and emotional and cognitive information processing. Thus, in the dentate gyrus (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. 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.
2021-2024
Mittelgeber: 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.
2021-2024
Mittelgeber: Deutsche Forschungsgemeinschaft (DFG)
Deep lung aerosol generation and virus encapsulation
Microscopic aerosols have been identified as the prime infection pathways for SARS-CoV-2. These droplets are generated deep in the lung from lining fluids. During breathing thin films form and rupture, thereby releasing fine droplets that encapsulate the viral load. In contrast to larger droplets formed in the upper airways, microscopic droplets studied here remain suspended in air much longer and thus pose a higher risk for airborne infection. Here, an interdisciplinary research team will tackle the science of aerosol generation and virus encapsulation connecting medical, biological, and fluid mechanics expertise. We will emphasis on realistic fluids together with viral particles and focus on the fast and delicate flows resulting to film rupture, droplet generation, encapsulation, and stabilization. Emphasis is placed on high spatio-temporal resolution experimentation, simulations of the atomization and drop formation process of thin films, and the biological virulence of the thereby generated aerosol particles. While the research was motivated from the virulence of SARS-CoV-2, it will also test other viruses to unravel the fundamental fluid mechanics that results to airborne transmission of pathogens from the lung.
2022-2024
Mittelgeber: Deutsche Forschungsgemeinschaft (DFG)
Integrating machine learning in combinatorial dynamic optimization for urban transportation services
The goal of this project is to provide effective decision support for stochastic dynamic pickup and delivery problems by combining the strengths of mixed-integer linear programming (MILP) and reinforcement learning (RL).Stochastic dynamic pickup-and-delivery problems play an increasingly important role in urban logistics. They are characterized by the often time-critical transport of wares or passengers in the city. Common examples are same-day delivery, ridesharing, and restaurant meal delivery. The mentioned problems have in common that a sequence of decision problems with future uncertainty must be solved in every decision step where the full value of a decision reveals only later in the service horizon. Searching the combinatorial decision space of the subproblems for efficient and feasible tours is a complex task of solving a MILP. This complexity is now multiplied by the challenge of evaluating such decision with respect to their effectiveness given future dynamism and uncertainty; an ideal case for RL. Both are crucial to fully meet operational requirements. Therefore, a direct combination of both methods is needed. Yet, a seamless integration has not been established due to different reasons and is the aim of this research project. We suggest using RL to manipulate the MILP itself to derive not only efficient but also effective decisions. This manipulation may change the objective function or the constraints. Incentive or penalty terms can be added to the objective function to enforce or prohibit the selection of certain decisions. Alternatively, the constraints may be adapted to reserve fleet-resources.The challenge is to decide where and how the manipulation takes place. SDPDPs have constraints with respect to routing, vehicle capacities, or time windows. Some constraints may be irrelevant for the fleet¿s flexibility while others might be binding. The first part of the research project focuses on identifying the "interesting¿ parts of the MILP via (un-)supervised learning. Once the "interesting¿ parts are identified, the second challenge is to find the right parametrization. Here, we will apply RL methods to learn the state-dependent manipulation of the MILP components.
2021-2024
Mittelgeber: 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.
2021-2024
Mittelgeber: 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.
2020-2024
Mittelgeber: 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.
2022-2024
Mittelgeber: Deutsche Forschungsgemeinschaft (DFG)
State-dependent decoding and control of neuronal circuits and signals for perceptual decisions
2020-2024
Mittelgeber: Deutsche Forschungsgemeinschaft (DFG)
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Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum.
2021-2024
Mittelgeber: Deutsche Forschungsgemeinschaft (DFG)
ADAMANT-II: Adaptive Data Management in Evolving Heterogeneous Hardware/Software Systems
Heterogeneous system architectures consisting of CPUs, GPUs and FPGAs offer a variety of optimization possibilities for database systems compared to pure CPU-based systems. However, it has been shown that it is not sufficient to just map existing software concepts one-to-one to non von-Neumann hardware architectures such as FPGAs to fully exploit their optimization potential. Rather, new processing capabilities require the design of novel processing concepts, which have to be considered at the planning level of query processing. A basic processing concept has already been developed in the first project phase by considering device-specific features in our plug¿n¿play system architecture. In fact, more advanced concepts are required to achieve an optimal exploitation of the capabilities of the hardware architectures. While significant speed-ups were achieved on the level of individual operators mapped to GPUs and FPGAs, the performance gain at the level of complete queries was unsatisfying. Hence, we derived the hypothesis for the second project phase that standard query-mapping approaches with their consideration of queries on the level of individual operators is not sufficient to explore the extended processing features of heterogeneous system architectures.
We will address this shortcoming by researching new processing and query mapping methods for heterogeneous systems, which question the commonly used granularity level of operators. Therefore, we will provide processing entities that encapsulate a greater functionality than standard database operators and may span multiple hardware devices. Thus, processing entities are intrinsically heterogeneous and combine the specific features of individual devices. As a result, our heterogeneous system architecture enables database operations and features that are not available or cannot be implemented efficiently in classical database systems.
To explore this extended feature set, we have identified three application domains that are still challenging for classical database systems and for which we assume that they will benefit greatly from heterogeneous system architectures: High-volume data feeds, approximate query processing and dynamic multi-query processing. The stream-based nature of high-volume data feeds asks for a hardware architecture where processing can be done on the fly without the need to store data beforehand. Hence, FPGAs are a promising hardware platform for processing high-volume data feed applications. Furthermore, FPGAs as well as GPUs are good platforms for approximate query processing, as they allow for approximate arithmetics and hardware-influenced sampling techniques. Dynamic multi-query processing is very challenging from the system management point of view, as query plans that have performed well for one workload can be inefficient for a different workload. Here, the multi-level parallelism of heterogeneous systems offers better opportunities to handle heavy workloads.
2021-2024
Mittelgeber: Deutsche Forschungsgemeinschaft (DFG)
Deep Lung Aerosol Generation and Virus Encapsulation (AGAVE)
The aim of the interdisciplinary project, which is funded by the German Research Foundation (DFG) to the tune of almost ¿900,000, is to find out why the phenomenon of so-called "superspreaders¿ exists. Researchers oft the three founded teams are looking into the question of how the virus particles in the human body are packed into the tiny aerosols and which mechanisms lead to these aerosol particles adhering to the airways of other people, where they burst and leading to further infection. Process engineers are then developing simulation models to assist in making reliable predictions about the distribution and spread of the aerosols.
2021-2024
Mittelgeber: Deutsche Forschungsgemeinschaft (DFG)
A Coupled Peridynamic-Finite-Element-Simulation for the Damage Analysis of Fibre Reinforced Composits
For the design, evaluation and approval of safety-relevant lightweight structures, the prediction of damage behaviour and residual strength within the scope of a damage tolerance assessment is decisive. Sufficiently precise and robust methods for the evaluation of a progressive damage are still missing for fiber reinforced plastics (FRP). Therefore, the damage initiation is usually utilized to determine the load-bearing capacity, which results in a conservative design For the design, evaluation and approval of safety-relevant lightweight structures, the prediction of damage behaviour and residual strength within the scope of a damage tolerance assessment is decisive. Sufficiently precise and robust methods for the evaluation of a progressive damage are still missing for fiber reinforced plastics (FRP). Therefore, the damage initiation is usually utilized to determine the load-bearing capacity, which results in a conservative design [1]. The key challenge of the analysis of FRPs in comparison to metallic materials consists in the heterogeneity of the material which results in complex failure mechanisms For the design, evaluation and approval of safety-relevant lightweight structures, the prediction of damage behaviour and residual strength within the scope of a damage tolerance assessment is decisive. Sufficiently precise and robust methods for the evaluation of a progressive damage are still missing for fiber reinforced plastics (FRP). Therefore, the damage initiation is usually utilized to determine the load-bearing capacity, which results in a conservative design [1]. The key challenge of the analysis of FRPs in comparison to metallic materials consists in the heterogeneity of the material which results in complex failure mechanisms [2]. A simulation method for the strength assessment has to take into account the damage initiation as well as the damage progression including all involved mechanisms and their interactions. The aim of the DFG project is the development of an improved damage assessment method for FRPs. The proposed solution is a new adaptive approach consisting of an interlink of the peridynamic methodology for potentially damaged parts of a structure with a FEM approach for undamaged regions. The objective of the approach is a significant improvement of the prediction accuracy of the load-bearing capacity of a structure which helps to develop more robust, safer and resource-conserving structures. The peridynamic theory is a promising method for analyzing the damage of homogeneous and heterogeneous materials For the design, evaluation and approval of safety-relevant lightweight structures, the prediction of damage behaviour and residual strength within the scope of a damage tolerance assessment is decisive. Sufficiently precise and robust methods for the evaluation of a progressive damage are still missing for fiber reinforced plastics (FRP). Therefore, the damage initiation is usually utilized to determine the load-bearing capacity, which results in a conservative design [1]. The key challenge of the analysis of FRPs in comparison to metallic materials consists in the heterogeneity of the material which results in complex failure mechanisms [2]. A simulation method for the strength assessment has to take into account the damage initiation as well as the damage progression including all involved mechanisms and their interactions. The aim of the DFG project is the development of an improved damage assessment method for FRPs. The proposed solution is a new adaptive approach consisting of an interlink of the peridynamic methodology for potentially damaged parts of a structure with a FEM approach for undamaged regions. The objective of the approach is a significant improvement of the prediction accuracy of the load-bearing capacity of a structure which helps to develop more robust, safer and resource-conserving structures. The peridynamic theory is a promising method for analyzing the damage of homogeneous and heterogeneous materials [3], For the design, evaluation and approval of safety-relevant lightweight structures, the prediction of damage behaviour and residual strength within the scope of a damage tolerance assessment is decisive. Sufficiently precise and robust methods for the evaluation of a progressive damage are still missing for fiber reinforced plastics (FRP). Therefore, the damage initiation is usually utilized to determine the load-bearing capacity, which results in a conservative design [1]. The key challenge of the analysis of FRPs in comparison to metallic materials consists in the heterogeneity of the material which results in complex failure mechanisms [2]. A simulation method for the strength assessment has to take into account the damage initiation as well as the damage progression including all involved mechanisms and their interactions. The aim of the DFG project is the development of an improved damage assessment method for FRPs. The proposed solution is a new adaptive approach consisting of an interlink of the peridynamic methodology for potentially damaged parts of a structure with a FEM approach for undamaged regions. The objective of the approach is a significant improvement of the prediction accuracy of the load-bearing capacity of a structure which helps to develop more robust, safer and resource-conserving structures. The peridynamic theory is a promising method for analyzing the damage of homogeneous and heterogeneous materials [3], [4]. But, the application of the peridynamic approach for undamaged regions requires an unnecessary high effort for receiving sufficient accurate results For the design, evaluation and approval of safety-relevant lightweight structures, the prediction of damage behaviour and residual strength within the scope of a damage tolerance assessment is decisive. Sufficiently precise and robust methods for the evaluation of a progressive damage are still missing for fiber reinforced plastics (FRP). Therefore, the damage initiation is usually utilized to determine the load-bearing capacity, which results in a conservative design [1]. The key challenge of the analysis of FRPs in comparison to metallic materials consists in the heterogeneity of the material which results in complex failure mechanisms [2]. A simulation method for the strength assessment has to take into account the damage initiation as well as the damage progression including all involved mechanisms and their interactions. The aim of the DFG project is the development of an improved damage assessment method for FRPs. The proposed solution is a new adaptive approach consisting of an interlink of the peridynamic methodology for potentially damaged parts of a structure with a FEM approach for undamaged regions. The objective of the approach is a significant improvement of the prediction accuracy of the load-bearing capacity of a structure which helps to develop more robust, safer and resource-conserving structures. The peridynamic theory is a promising method for analyzing the damage of homogeneous and heterogeneous materials [3], [4]. But, the application of the peridynamic approach for undamaged regions requires an unnecessary high effort for receiving sufficient accurate results [5], For the design, evaluation and approval of safety-relevant lightweight structures, the prediction of damage behaviour and residual strength within the scope of a damage tolerance assessment is decisive. Sufficiently precise and robust methods for the evaluation of a progressive damage are still missing for fiber reinforced plastics (FRP). Therefore, the damage initiation is usually utilized to determine the load-bearing capacity, which results in a conservative design [1]. The key challenge of the analysis of FRPs in comparison to metallic materials consists in the heterogeneity of the material which results in complex failure mechanisms [2]. A simulation method for the strength assessment has to take into account the damage initiation as well as the damage progression including all involved mechanisms and their interactions. The aim of the DFG project is the development of an improved damage assessment method for FRPs. The proposed solution is a new adaptive approach consisting of an interlink of the peridynamic methodology for potentially damaged parts of a structure with a FEM approach for undamaged regions. The objective of the approach is a significant improvement of the prediction accuracy of the load-bearing capacity of a structure which helps to develop more robust, safer and resource-conserving structures. The peridynamic theory is a promising method for analyzing the damage of homogeneous and heterogeneous materials [3], [4]. But, the application of the peridynamic approach for undamaged regions requires an unnecessary high effort for receiving sufficient accurate results [5], [6]. In contrast, the FEM as a classical continuum mechanics based approach is very efficient, if continuous stress distributions can be assumed and finite elements with higher shape functions (p-elements) are applied For the design, evaluation and approval of safety-relevant lightweight structures, the prediction of damage behaviour and residual strength within the scope of a damage tolerance assessment is decisive. Sufficiently precise and robust methods for the evaluation of a progressive damage are still missing for fiber reinforced plastics (FRP). Therefore, the damage initiation is usually utilized to determine the load-bearing capacity, which results in a conservative design [1]. The key challenge of the analysis of FRPs in comparison to metallic materials consists in the heterogeneity of the material which results in complex failure mechanisms [2]. A simulation method for the strength assessment has to take into account the damage initiation as well as the damage progression including all involved mechanisms and their interactions. The aim of the DFG project is the development of an improved damage assessment method for FRPs. The proposed solution is a new adaptive approach consisting of an interlink of the peridynamic methodology for potentially damaged parts of a structure with a FEM approach for undamaged regions. The objective of the approach is a significant improvement of the prediction accuracy of the load-bearing capacity of a structure which helps to develop more robust, safer and resource-conserving structures. The peridynamic theory is a promising method for analyzing the damage of homogeneous and heterogeneous materials [3], [4]. But, the application of the peridynamic approach for undamaged regions requires an unnecessary high effort for receiving sufficient accurate results [5], [6]. In contrast, the FEM as a classical continuum mechanics based approach is very efficient, if continuous stress distributions can be assumed and finite elements with higher shape functions (p-elements) are applied [7], For the design, evaluation and approval of safety-relevant lightweight structures, the prediction of damage behaviour and residual strength within the scope of a damage tolerance assessment is decisive. Sufficiently precise and robust methods for the evaluation of a progressive damage are still missing for fiber reinforced plastics (FRP). Therefore, the damage initiation is usually utilized to determine the load-bearing capacity, which results in a conservative design [1]. The key challenge of the analysis of FRPs in comparison to metallic materials consists in the heterogeneity of the material which results in complex failure mechanisms [2]. A simulation method for the strength assessment has to take into account the damage initiation as well as the damage progression including all involved mechanisms and their interactions. The aim of the DFG project is the development of an improved damage assessment method for FRPs. The proposed solution is a new adaptive approach consisting of an interlink of the peridynamic methodology for potentially damaged parts of a structure with a FEM approach for undamaged regions. The objective of the approach is a significant improvement of the prediction accuracy of the load-bearing capacity of a structure which helps to develop more robust, safer and resource-conserving structures. The peridynamic theory is a promising method for analyzing the damage of homogeneous and heterogeneous materials [3], [4]. But, the application of the peridynamic approach for undamaged regions requires an unnecessary high effort for receiving sufficient accurate results [5], [6]. In contrast, the FEM as a classical continuum mechanics based approach is very efficient, if continuous stress distributions can be assumed and finite elements with higher shape functions (p-elements) are applied [7], [8]. A coupling of a peridynamic based simulation method with the FEM will result in a robust and efficient methodology to predict the damage initiation and the damage progress in specified (critical) regions For the design, evaluation and approval of safety-relevant lightweight structures, the prediction of damage behaviour and residual strength within the scope of a damage tolerance assessment is decisive. Sufficiently precise and robust methods for the evaluation of a progressive damage are still missing for fiber reinforced plastics (FRP). Therefore, the damage initiation is usually utilized to determine the load-bearing capacity, which results in a conservative design [1]. The key challenge of the analysis of FRPs in comparison to metallic materials consists in the heterogeneity of the material which results in complex failure mechanisms [2]. A simulation method for the strength assessment has to take into account the damage initiation as well as the damage progression including all involved mechanisms and their interactions. The aim of the DFG project is the development of an improved damage assessment method for FRPs. The proposed solution is a new adaptive approach consisting of an interlink of the peridynamic methodology for potentially damaged parts of a structure with a FEM approach for undamaged regions. The objective of the approach is a significant improvement of the prediction accuracy of the load-bearing capacity of a structure which helps to develop more robust, safer and resource-conserving structures. The peridynamic theory is a promising method for analyzing the damage of homogeneous and heterogeneous materials [3], [4]. But, the application of the peridynamic approach for undamaged regions requires an unnecessary high effort for receiving sufficient accurate results [5], [6]. In contrast, the FEM as a classical continuum mechanics based approach is very efficient, if continuous stress distributions can be assumed and finite elements with higher shape functions (p-elements) are applied [7], [8]. A coupling of a peridynamic based simulation method with the FEM will result in a robust and efficient methodology to predict the damage initiation and the damage progress in specified (critical) regions [9], For the design, evaluation and approval of safety-relevant lightweight structures, the prediction of damage behaviour and residual strength within the scope of a damage tolerance assessment is decisive. Sufficiently precise and robust methods for the evaluation of a progressive damage are still missing for fiber reinforced plastics (FRP). Therefore, the damage initiation is usually utilized to determine the load-bearing capacity, which results in a conservative design [1]. The key challenge of the analysis of FRPs in comparison to metallic materials consists in the heterogeneity of the material which results in complex failure mechanisms [2]. A simulation method for the strength assessment has to take into account the damage initiation as well as the damage progression including all involved mechanisms and their interactions. The aim of the DFG project is the development of an improved damage assessment method for FRPs. The proposed solution is a new adaptive approach consisting of an interlink of the peridynamic methodology for potentially damaged parts of a structure with a FEM approach for undamaged regions. The objective of the approach is a significant improvement of the prediction accuracy of the load-bearing capacity of a structure which helps to develop more robust, safer and resource-conserving structures. The peridynamic theory is a promising method for analyzing the damage of homogeneous and heterogeneous materials [3], [4]. But, the application of the peridynamic approach for undamaged regions requires an unnecessary high effort for receiving sufficient accurate results [5], [6]. In contrast, the FEM as a classical continuum mechanics based approach is very efficient, if continuous stress distributions can be assumed and finite elements with higher shape functions (p-elements) are applied [7], [8]. A coupling of a peridynamic based simulation method with the FEM will result in a robust and efficient methodology to predict the damage initiation and the damage progress in specified (critical) regions [9], [10]. This approach also allows the modelling of the feedback of a damage region to the undamaged area of a structure. In the project the peridynamic will be extended to model damages in anisotropic FPR materials on an energy based damage approach For the design, evaluation and approval of safety-relevant lightweight structures, the prediction of damage behaviour and residual strength within the scope of a damage tolerance assessment is decisive. Sufficiently precise and robust methods for the evaluation of a progressive damage are still missing for fiber reinforced plastics (FRP). Therefore, the damage initiation is usually utilized to determine the load-bearing capacity, which results in a conservative design [1]. The key challenge of the analysis of FRPs in comparison to metallic materials consists in the heterogeneity of the material which results in complex failure mechanisms [2]. A simulation method for the strength assessment has to take into account the damage initiation as well as the damage progression including all involved mechanisms and their interactions. The aim of the DFG project is the development of an improved damage assessment method for FRPs. The proposed solution is a new adaptive approach consisting of an interlink of the peridynamic methodology for potentially damaged parts of a structure with a FEM approach for undamaged regions. The objective of the approach is a significant improvement of the prediction accuracy of the load-bearing capacity of a structure which helps to develop more robust, safer and resource-conserving structures. The peridynamic theory is a promising method for analyzing the damage of homogeneous and heterogeneous materials [3], [4]. But, the application of the peridynamic approach for undamaged regions requires an unnecessary high effort for receiving sufficient accurate results [5], [6]. In contrast, the FEM as a classical continuum mechanics based approach is very efficient, if continuous stress distributions can be assumed and finite elements with higher shape functions (p-elements) are applied [7], [8]. A coupling of a peridynamic based simulation method with the FEM will result in a robust and efficient methodology to predict the damage initiation and the damage progress in specified (critical) regions [9], [10]. This approach also allows the modelling of the feedback of a damage region to the undamaged area of a structure. In the project the peridynamic will be extended to model damages in anisotropic FPR materials on an energy based damage approach [6]. For the coupling of the Peridynamik with the FEM a new coupling methodology will be developed, tested und implemented, e.g. based on the Arlequin method For the design, evaluation and approval of safety-relevant lightweight structures, the prediction of damage behaviour and residual strength within the scope of a damage tolerance assessment is decisive. Sufficiently precise and robust methods for the evaluation of a progressive damage are still missing for fiber reinforced plastics (FRP). Therefore, the damage initiation is usually utilized to determine the load-bearing capacity, which results in a conservative design [1]. The key challenge of the analysis of FRPs in comparison to metallic materials consists in the heterogeneity of the material which results in complex failure mechanisms [2]. A simulation method for the strength assessment has to take into account the damage initiation as well as the damage progression including all involved mechanisms and their interactions. The aim of the DFG project is the development of an improved damage assessment method for FRPs. The proposed solution is a new adaptive approach consisting of an interlink of the peridynamic methodology for potentially damaged parts of a structure with a FEM approach for undamaged regions. The objective of the approach is a significant improvement of the prediction accuracy of the load-bearing capacity of a structure which helps to develop more robust, safer and resource-conserving structures. The peridynamic theory is a promising method for analyzing the damage of homogeneous and heterogeneous materials [3], [4]. But, the application of the peridynamic approach for undamaged regions requires an unnecessary high effort for receiving sufficient accurate results [5], [6]. In contrast, the FEM as a classical continuum mechanics based approach is very efficient, if continuous stress distributions can be assumed and finite elements with higher shape functions (p-elements) are applied [7], [8]. A coupling of a peridynamic based simulation method with the FEM will result in a robust and efficient methodology to predict the damage initiation and the damage progress in specified (critical) regions [9], [10]. This approach also allows the modelling of the feedback of a damage region to the undamaged area of a structure. In the project the peridynamic will be extended to model damages in anisotropic FPR materials on an energy based damage approach [6]. For the coupling of the Peridynamik with the FEM a new coupling methodology will be developed, tested und implemented, e.g. based on the Arlequin method [12]. The software tools, developed in the proposed project will be freely-available as open-source software for other researchers in accordance with the DFG objectives of sustainability of research software in the context of the DFG program "e-Research Technologies¿.

For the design, evaluation and approval of safety-relevant lightweight structures, the prediction of damage behaviour and residual strength within the scope of a damage tolerance assessment is decisive. Sufficiently precise and robust methods for the evaluation of a progressive damage are still missing for fiber reinforced plastics (FRP). Therefore, the damage initiation is usually utilized to determine the load-bearing capacity, which results in a conservative design [1]. The key challenge of the analysis of FRPs in comparison to metallic materials consists in the heterogeneity of the material which results in complex failure mechanisms [2]. A simulation method for the strength assessment has to take into account the damage initiation as well as the damage progression including all involved mechanisms and their interactions. The aim of the DFG project is the development of an improved damage assessment method for FRPs. The proposed solution is a new adaptive approach consisting of an interlink of the peridynamic methodology for potentially damaged parts of a structure with a FEM approach for undamaged regions. The objective of the approach is a significant improvement of the prediction accuracy of the load-bearing capacity of a structure which helps to develop more robust, safer and resource-conserving structures. The peridynamic theory is a promising method for analyzing the damage of homogeneous and heterogeneous materials [3], [4]. But, the application of the peridynamic approach for undamaged regions requires an unnecessary high effort for receiving sufficient accurate results [5], [6]. In contrast, the FEM as a classical continuum mechanics based approach is very efficient, if continuous stress distributions can be assumed and finite elements with higher shape functions (p-elements) are applied [7], [8]. A coupling of a peridynamic based simulation method with the FEM will result in a robust and efficient methodology to predict the damage initiation and the damage progress in specified (critical) regions [9], [10]. This approach also allows the modelling of the feedback of a damage region to the undamaged area of a structure. In the project the peridynamic will be extended to model damages in anisotropic FPR materials on an energy based damage approach [6]. For the coupling of the Peridynamik with the FEM a new coupling methodology will be developed, tested und implemented, e.g. based on the Arlequin method [12]. The software tools, developed in the proposed project will be freely-available as open-source software for other researchers in accordance with the DFG objectives of sustainability of research software in the context of the DFG program "e-Research Technologies¿.

[1] Gross, D., Seelig, T.: Bruchmechanik - Mit einer Einführung in die Mikromechanik. Springer Vieweg,
2018.
For the design, evaluation and approval of safety-relevant lightweight structures, the prediction of damage behaviour and residual strength within the scope of a damage tolerance assessment is decisive. Sufficiently precise and robust methods for the evaluation of a progressive damage are still missing for fiber reinforced plastics (FRP). Therefore, the damage initiation is usually utilized to determine the load-bearing capacity, which results in a conservative design [1]. The key challenge of the analysis of FRPs in comparison to metallic materials consists in the heterogeneity of the material which results in complex failure mechanisms [2]. A simulation method for the strength assessment has to take into account the damage initiation as well as the damage progression including all involved mechanisms and their interactions. The aim of the DFG project is the development of an improved damage assessment method for FRPs. The proposed solution is a new adaptive approach consisting of an interlink of the peridynamic methodology for potentially damaged parts of a structure with a FEM approach for undamaged regions. The objective of the approach is a significant improvement of the prediction accuracy of the load-bearing capacity of a structure which helps to develop more robust, safer and resource-conserving structures. The peridynamic theory is a promising method for analyzing the damage of homogeneous and heterogeneous materials [3], [4]. But, the application of the peridynamic approach for undamaged regions requires an unnecessary high effort for receiving sufficient accurate results [5], [6]. In contrast, the FEM as a classical continuum mechanics based approach is very efficient, if continuous stress distributions can be assumed and finite elements with higher shape functions (p-elements) are applied [7], [8]. A coupling of a peridynamic based simulation method with the FEM will result in a robust and efficient methodology to predict the damage initiation and the damage progress in specified (critical) regions [9], [10]. This approach also allows the modelling of the feedback of a damage region to the undamaged area of a structure. In the project the peridynamic will be extended to model damages in anisotropic FPR materials on an energy based damage approach [6]. For the coupling of the Peridynamik with the FEM a new coupling methodology will be developed, tested und implemented, e.g. based on the Arlequin method [12]. The software tools, developed in the proposed project will be freely-available as open-source software for other researchers in accordance with the DFG objectives of sustainability of research software in the context of the DFG program "e-Research Technologies¿.

[1] Gross, D., Seelig, T.: Bruchmechanik - Mit einer Einführung in die Mikromechanik. Springer Vieweg,
2018.
[2] Puck, A.: Festigkeitsanalyse von Faser-Matrix-Laminaten. Hanser, 1996.
For the design, evaluation and approval of safety-relevant lightweight structures, the prediction of damage behaviour and residual strength within the scope of a damage tolerance assessment is decisive. Sufficiently precise and robust methods for the evaluation of a progressive damage are still missing for fiber reinforced plastics (FRP). Therefore, the damage initiation is usually utilized to determine the load-bearing capacity, which results in a conservative design [1]. The key challenge of the analysis of FRPs in comparison to metallic materials consists in the heterogeneity of the material which results in complex failure mechanisms [2]. A simulation method for the strength assessment has to take into account the damage initiation as well as the damage progression including all involved mechanisms and their interactions. The aim of the DFG project is the development of an improved damage assessment method for FRPs. The proposed solution is a new adaptive approach consisting of an interlink of the peridynamic methodology for potentially damaged parts of a structure with a FEM approach for undamaged regions. The objective of the approach is a significant improvement of the prediction accuracy of the load-bearing capacity of a structure which helps to develop more robust, safer and resource-conserving structures. The peridynamic theory is a promising method for analyzing the damage of homogeneous and heterogeneous materials [3], [4]. But, the application of the peridynamic approach for undamaged regions requires an unnecessary high effort for receiving sufficient accurate results [5], [6]. In contrast, the FEM as a classical continuum mechanics based approach is very efficient, if continuous stress distributions can be assumed and finite elements with higher shape functions (p-elements) are applied [7], [8]. A coupling of a peridynamic based simulation method with the FEM will result in a robust and efficient methodology to predict the damage initiation and the damage progress in specified (critical) regions [9], [10]. This approach also allows the modelling of the feedback of a damage region to the undamaged area of a structure. In the project the peridynamic will be extended to model damages in anisotropic FPR materials on an energy based damage approach [6]. For the coupling of the Peridynamik with the FEM a new coupling methodology will be developed, tested und implemented, e.g. based on the Arlequin method [12]. The software tools, developed in the proposed project will be freely-available as open-source software for other researchers in accordance with the DFG objectives of sustainability of research software in the context of the DFG program "e-Research Technologies¿.

[1] Gross, D., Seelig, T.: Bruchmechanik - Mit einer Einführung in die Mikromechanik. Springer Vieweg,
2018.
[2] Puck, A.: Festigkeitsanalyse von Faser-Matrix-Laminaten. Hanser, 1996.
[3] Silling, S.A., Lehoucq, R.B.: Peridynamic Theory of Solid Mechanics, Advances in Applied
Mechanics, 44 (2010), pp. 73-168.
For the design, evaluation and approval of safety-relevant lightweight structures, the prediction of damage behaviour and residual strength within the scope of a damage tolerance assessment is decisive. Sufficiently precise and robust methods for the evaluation of a progressive damage are still missing for fiber reinforced plastics (FRP). Therefore, the damage initiation is usually utilized to determine the load-bearing capacity, which results in a conservative design [1]. The key challenge of the analysis of FRPs in comparison to metallic materials consists in the heterogeneity of the material which results in complex failure mechanisms [2]. A simulation method for the strength assessment has to take into account the damage initiation as well as the damage progression including all involved mechanisms and their interactions. The aim of the DFG project is the development of an improved damage assessment method for FRPs. The proposed solution is a new adaptive approach consisting of an interlink of the peridynamic methodology for potentially damaged parts of a structure with a FEM approach for undamaged regions. The objective of the approach is a significant improvement of the prediction accuracy of the load-bearing capacity of a structure which helps to develop more robust, safer and resource-conserving structures. The peridynamic theory is a promising method for analyzing the damage of homogeneous and heterogeneous materials [3], [4]. But, the application of the peridynamic approach for undamaged regions requires an unnecessary high effort for receiving sufficient accurate results [5], [6]. In contrast, the FEM as a classical continuum mechanics based approach is very efficient, if continuous stress distributions can be assumed and finite elements with higher shape functions (p-elements) are applied [7], [8]. A coupling of a peridynamic based simulation method with the FEM will result in a robust and efficient methodology to predict the damage initiation and the damage progress in specified (critical) regions [9], [10]. This approach also allows the modelling of the feedback of a damage region to the undamaged area of a structure. In the project the peridynamic will be extended to model damages in anisotropic FPR materials on an energy based damage approach [6]. For the coupling of the Peridynamik with the FEM a new coupling methodology will be developed, tested und implemented, e.g. based on the Arlequin method [12]. The software tools, developed in the proposed project will be freely-available as open-source software for other researchers in accordance with the DFG objectives of sustainability of research software in the context of the DFG program "e-Research Technologies¿.

[1] Gross, D., Seelig, T.: Bruchmechanik - Mit einer Einführung in die Mikromechanik. Springer Vieweg,
2018.
[2] Puck, A.: Festigkeitsanalyse von Faser-Matrix-Laminaten. Hanser, 1996.
[3] Silling, S.A., Lehoucq, R.B.: Peridynamic Theory of Solid Mechanics, Advances in Applied
Mechanics, 44 (2010), pp. 73-168.
[4] Madenci, E., Oterkus, E.: Peridynamic Theory and Its Applications, Springer 2014
For the design, evaluation and approval of safety-relevant lightweight structures, the prediction of damage behaviour and residual strength within the scope of a damage tolerance assessment is decisive. Sufficiently precise and robust methods for the evaluation of a progressive damage are still missing for fiber reinforced plastics (FRP). Therefore, the damage initiation is usually utilized to determine the load-bearing capacity, which results in a conservative design [1]. The key challenge of the analysis of FRPs in comparison to metallic materials consists in the heterogeneity of the material which results in complex failure mechanisms [2]. A simulation method for the strength assessment has to take into account the damage initiation as well as the damage progression including all involved mechanisms and their interactions. The aim of the DFG project is the development of an improved damage assessment method for FRPs. The proposed solution is a new adaptive approach consisting of an interlink of the peridynamic methodology for potentially damaged parts of a structure with a FEM approach for undamaged regions. The objective of the approach is a significant improvement of the prediction accuracy of the load-bearing capacity of a structure which helps to develop more robust, safer and resource-conserving structures. The peridynamic theory is a promising method for analyzing the damage of homogeneous and heterogeneous materials [3], [4]. But, the application of the peridynamic approach for undamaged regions requires an unnecessary high effort for receiving sufficient accurate results [5], [6]. In contrast, the FEM as a classical continuum mechanics based approach is very efficient, if continuous stress distributions can be assumed and finite elements with higher shape functions (p-elements) are applied [7], [8]. A coupling of a peridynamic based simulation method with the FEM will result in a robust and efficient methodology to predict the damage initiation and the damage progress in specified (critical) regions [9], [10]. This approach also allows the modelling of the feedback of a damage region to the undamaged area of a structure. In the project the peridynamic will be extended to model damages in anisotropic FPR materials on an energy based damage approach [6]. For the coupling of the Peridynamik with the FEM a new coupling methodology will be developed, tested und implemented, e.g. based on the Arlequin method [12]. The software tools, developed in the proposed project will be freely-available as open-source software for other researchers in accordance with the DFG objectives of sustainability of research software in the context of the DFG program "e-Research Technologies¿.

[1] Gross, D., Seelig, T.: Bruchmechanik - Mit einer Einführung in die Mikromechanik. Springer Vieweg,
2018.
[2] Puck, A.: Festigkeitsanalyse von Faser-Matrix-Laminaten. Hanser, 1996.
[3] Silling, S.A., Lehoucq, R.B.: Peridynamic Theory of Solid Mechanics, Advances in Applied
Mechanics, 44 (2010), pp. 73-168.
[4] Madenci, E., Oterkus, E.: Peridynamic Theory and Its Applications, Springer 2014
[5] Willberg, C., Krause, D.: Peridynamic analysis of fibre-matrix debond and matrix failure
mechanisms in composites under transverse tensile load by an energy-based damage criterion,
Composites Part B: Engineering, Volume 158, February 2019, pp. 18-27.
For the design, evaluation and approval of safety-relevant lightweight structures, the prediction of damage behaviour and residual strength within the scope of a damage tolerance assessment is decisive. Sufficiently precise and robust methods for the evaluation of a progressive damage are still missing for fiber reinforced plastics (FRP). Therefore, the damage initiation is usually utilized to determine the load-bearing capacity, which results in a conservative design [1]. The key challenge of the analysis of FRPs in comparison to metallic materials consists in the heterogeneity of the material which results in complex failure mechanisms [2]. A simulation method for the strength assessment has to take into account the damage initiation as well as the damage progression including all involved mechanisms and their interactions. The aim of the DFG project is the development of an improved damage assessment method for FRPs. The proposed solution is a new adaptive approach consisting of an interlink of the peridynamic methodology for potentially damaged parts of a structure with a FEM approach for undamaged regions. The objective of the approach is a significant improvement of the prediction accuracy of the load-bearing capacity of a structure which helps to develop more robust, safer and resource-conserving structures. The peridynamic theory is a promising method for analyzing the damage of homogeneous and heterogeneous materials [3], [4]. But, the application of the peridynamic approach for undamaged regions requires an unnecessary high effort for receiving sufficient accurate results [5], [6]. In contrast, the FEM as a classical continuum mechanics based approach is very efficient, if continuous stress distributions can be assumed and finite elements with higher shape functions (p-elements) are applied [7], [8]. A coupling of a peridynamic based simulation method with the FEM will result in a robust and efficient methodology to predict the damage initiation and the damage progress in specified (critical) regions [9], [10]. This approach also allows the modelling of the feedback of a damage region to the undamaged area of a structure. In the project the peridynamic will be extended to model damages in anisotropic FPR materials on an energy based damage approach [6]. For the coupling of the Peridynamik with the FEM a new coupling methodology will be developed, tested und implemented, e.g. based on the Arlequin method [12]. The software tools, developed in the proposed project will be freely-available as open-source software for other researchers in accordance with the DFG objectives of sustainability of research software in the context of the DFG program "e-Research Technologies¿.

[1] Gross, D., Seelig, T.: Bruchmechanik - Mit einer Einführung in die Mikromechanik. Springer Vieweg,
2018.
[2] Puck, A.: Festigkeitsanalyse von Faser-Matrix-Laminaten. Hanser, 1996.
[3] Silling, S.A., Lehoucq, R.B.: Peridynamic Theory of Solid Mechanics, Advances in Applied
Mechanics, 44 (2010), pp. 73-168.
[4] Madenci, E., Oterkus, E.: Peridynamic Theory and Its Applications, Springer 2014
[5] Willberg, C., Krause, D.: Peridynamic analysis of fibre-matrix debond and matrix failure
mechanisms in composites under transverse tensile load by an energy-based damage criterion,
Composites Part B: Engineering, Volume 158, February 2019, pp. 18-27.
[6] Willberg, C., Wiedemann, L., Rädel, M.: A mode-dependent energy-based damage model for
peridynamics and its implementation, J. Mechanics of Materials and Structures, Vol. 14, 2, 2019,
pp. 193-217.
For the design, evaluation and approval of safety-relevant lightweight structures, the prediction of damage behaviour and residual strength within the scope of a damage tolerance assessment is decisive. Sufficiently precise and robust methods for the evaluation of a progressive damage are still missing for fiber reinforced plastics (FRP). Therefore, the damage initiation is usually utilized to determine the load-bearing capacity, which results in a conservative design [1]. The key challenge of the analysis of FRPs in comparison to metallic materials consists in the heterogeneity of the material which results in complex failure mechanisms [2]. A simulation method for the strength assessment has to take into account the damage initiation as well as the damage progression including all involved mechanisms and their interactions. The aim of the DFG project is the development of an improved damage assessment method for FRPs. The proposed solution is a new adaptive approach consisting of an interlink of the peridynamic methodology for potentially damaged parts of a structure with a FEM approach for undamaged regions. The objective of the approach is a significant improvement of the prediction accuracy of the load-bearing capacity of a structure which helps to develop more robust, safer and resource-conserving structures. The peridynamic theory is a promising method for analyzing the damage of homogeneous and heterogeneous materials [3], [4]. But, the application of the peridynamic approach for undamaged regions requires an unnecessary high effort for receiving sufficient accurate results [5], [6]. In contrast, the FEM as a classical continuum mechanics based approach is very efficient, if continuous stress distributions can be assumed and finite elements with higher shape functions (p-elements) are applied [7], [8]. A coupling of a peridynamic based simulation method with the FEM will result in a robust and efficient methodology to predict the damage initiation and the damage progress in specified (critical) regions [9], [10]. This approach also allows the modelling of the feedback of a damage region to the undamaged area of a structure. In the project the peridynamic will be extended to model damages in anisotropic FPR materials on an energy based damage approach [6]. For the coupling of the Peridynamik with the FEM a new coupling methodology will be developed, tested und implemented, e.g. based on the Arlequin method [12]. The software tools, developed in the proposed project will be freely-available as open-source software for other researchers in accordance with the DFG objectives of sustainability of research software in the context of the DFG program "e-Research Technologies¿.

[1] Gross, D., Seelig, T.: Bruchmechanik - Mit einer Einführung in die Mikromechanik. Springer Vieweg,
2018.
[2] Puck, A.: Festigkeitsanalyse von Faser-Matrix-Laminaten. Hanser, 1996.
[3] Silling, S.A., Lehoucq, R.B.: Peridynamic Theory of Solid Mechanics, Advances in Applied
Mechanics, 44 (2010), pp. 73-168.
[4] Madenci, E., Oterkus, E.: Peridynamic Theory and Its Applications, Springer 2014
[5] Willberg, C., Krause, D.: Peridynamic analysis of fibre-matrix debond and matrix failure
mechanisms in composites under transverse tensile load by an energy-based damage criterion,
Composites Part B: Engineering, Volume 158, February 2019, pp. 18-27.
[6] Willberg, C., Wiedemann, L., Rädel, M.: A mode-dependent energy-based damage model for
peridynamics and its implementation, J. Mechanics of Materials and Structures, Vol. 14, 2, 2019,
pp. 193-217.
[7] Szabó, B., Babu¿ka, I.: Finite Element Analysis. John Wiley & Sons, 1991.
For the design, evaluation and approval of safety-relevant lightweight structures, the prediction of damage behaviour and residual strength within the scope of a damage tolerance assessment is decisive. Sufficiently precise and robust methods for the evaluation of a progressive damage are still missing for fiber reinforced plastics (FRP). Therefore, the damage initiation is usually utilized to determine the load-bearing capacity, which results in a conservative design [1]. The key challenge of the analysis of FRPs in comparison to metallic materials consists in the heterogeneity of the material which results in complex failure mechanisms [2]. A simulation method for the strength assessment has to take into account the damage initiation as well as the damage progression including all involved mechanisms and their interactions. The aim of the DFG project is the development of an improved damage assessment method for FRPs. The proposed solution is a new adaptive approach consisting of an interlink of the peridynamic methodology for potentially damaged parts of a structure with a FEM approach for undamaged regions. The objective of the approach is a significant improvement of the prediction accuracy of the load-bearing capacity of a structure which helps to develop more robust, safer and resource-conserving structures. The peridynamic theory is a promising method for analyzing the damage of homogeneous and heterogeneous materials [3], [4]. But, the application of the peridynamic approach for undamaged regions requires an unnecessary high effort for receiving sufficient accurate results [5], [6]. In contrast, the FEM as a classical continuum mechanics based approach is very efficient, if continuous stress distributions can be assumed and finite elements with higher shape functions (p-elements) are applied [7], [8]. A coupling of a peridynamic based simulation method with the FEM will result in a robust and efficient methodology to predict the damage initiation and the damage progress in specified (critical) regions [9], [10]. This approach also allows the modelling of the feedback of a damage region to the undamaged area of a structure. In the project the peridynamic will be extended to model damages in anisotropic FPR materials on an energy based damage approach [6]. For the coupling of the Peridynamik with the FEM a new coupling methodology will be developed, tested und implemented, e.g. based on the Arlequin method [12]. The software tools, developed in the proposed project will be freely-available as open-source software for other researchers in accordance with the DFG objectives of sustainability of research software in the context of the DFG program "e-Research Technologies¿.

[1] Gross, D., Seelig, T.: Bruchmechanik - Mit einer Einführung in die Mikromechanik. Springer Vieweg,
2018.
[2] Puck, A.: Festigkeitsanalyse von Faser-Matrix-Laminaten. Hanser, 1996.
[3] Silling, S.A., Lehoucq, R.B.: Peridynamic Theory of Solid Mechanics, Advances in Applied
Mechanics, 44 (2010), pp. 73-168.
[4] Madenci, E., Oterkus, E.: Peridynamic Theory and Its Applications, Springer 2014
[5] Willberg, C., Krause, D.: Peridynamic analysis of fibre-matrix debond and matrix failure
mechanisms in composites under transverse tensile load by an energy-based damage criterion,
Composites Part B: Engineering, Volume 158, February 2019, pp. 18-27.
[6] Willberg, C., Wiedemann, L., Rädel, M.: A mode-dependent energy-based damage model for
peridynamics and its implementation, J. Mechanics of Materials and Structures, Vol. 14, 2, 2019,
pp. 193-217.
[7] Szabó, B., Babu¿ka, I.: Finite Element Analysis. John Wiley & Sons, 1991.
[8] Willberg, C., Duczek, S., Vivar-Perez, J.M. Schmicker, D., Gabbert, U.: Comparison of different
higher order nite element schemes for the simulation of Lamb waves, Computer Methods in
Applied Mechanics and Engineering, 241-244 (2012), S. 246-261.
For the design, evaluation and approval of safety-relevant lightweight structures, the prediction of damage behaviour and residual strength within the scope of a damage tolerance assessment is decisive. Sufficiently precise and robust methods for the evaluation of a progressive damage are still missing for fiber reinforced plastics (FRP). Therefore, the damage initiation is usually utilized to determine the load-bearing capacity, which results in a conservative design [1]. The key challenge of the analysis of FRPs in comparison to metallic materials consists in the heterogeneity of the material which results in complex failure mechanisms [2]. A simulation method for the strength assessment has to take into account the damage initiation as well as the damage progression including all involved mechanisms and their interactions. The aim of the DFG project is the development of an improved damage assessment method for FRPs. The proposed solution is a new adaptive approach consisting of an interlink of the peridynamic methodology for potentially damaged parts of a structure with a FEM approach for undamaged regions. The objective of the approach is a significant improvement of the prediction accuracy of the load-bearing capacity of a structure which helps to develop more robust, safer and resource-conserving structures. The peridynamic theory is a promising method for analyzing the damage of homogeneous and heterogeneous materials [3], [4]. But, the application of the peridynamic approach for undamaged regions requires an unnecessary high effort for receiving sufficient accurate results [5], [6]. In contrast, the FEM as a classical continuum mechanics based approach is very efficient, if continuous stress distributions can be assumed and finite elements with higher shape functions (p-elements) are applied [7], [8]. A coupling of a peridynamic based simulation method with the FEM will result in a robust and efficient methodology to predict the damage initiation and the damage progress in specified (critical) regions [9], [10]. This approach also allows the modelling of the feedback of a damage region to the undamaged area of a structure. In the project the peridynamic will be extended to model damages in anisotropic FPR materials on an energy based damage approach [6]. For the coupling of the Peridynamik with the FEM a new coupling methodology will be developed, tested und implemented, e.g. based on the Arlequin method [12]. The software tools, developed in the proposed project will be freely-available as open-source software for other researchers in accordance with the DFG objectives of sustainability of research software in the context of the DFG program "e-Research Technologies¿.

[1] Gross, D., Seelig, T.: Bruchmechanik - Mit einer Einführung in die Mikromechanik. Springer Vieweg,
2018.
[2] Puck, A.: Festigkeitsanalyse von Faser-Matrix-Laminaten. Hanser, 1996.
[3] Silling, S.A., Lehoucq, R.B.: Peridynamic Theory of Solid Mechanics, Advances in Applied
Mechanics, 44 (2010), pp. 73-168.
[4] Madenci, E., Oterkus, E.: Peridynamic Theory and Its Applications, Springer 2014
[5] Willberg, C., Krause, D.: Peridynamic analysis of fibre-matrix debond and matrix failure
mechanisms in composites under transverse tensile load by an energy-based damage criterion,
Composites Part B: Engineering, Volume 158, February 2019, pp. 18-27.
[6] Willberg, C., Wiedemann, L., Rädel, M.: A mode-dependent energy-based damage model for
peridynamics and its implementation, J. Mechanics of Materials and Structures, Vol. 14, 2, 2019,
pp. 193-217.
[7] Szabó, B., Babu¿ka, I.: Finite Element Analysis. John Wiley & Sons, 1991.
[8] Willberg, C., Duczek, S., Vivar-Perez, J.M. Schmicker, D., Gabbert, U.: Comparison of different
higher order nite element schemes for the simulation of Lamb waves, Computer Methods in
Applied Mechanics and Engineering, 241-244 (2012), S. 246-261.
[9] Oterkus, E., Madenci, E., Weckner, O., Silling, S.A., Bogert P., Tessler, A.: Combined nite element
and peridynamic analyses for predicting failure in a stiffened composite curved panel with a
central slot, Composite Structures, 94.3 (2012), pp. 839-850.
For the design, evaluation and approval of safety-relevant lightweight structures, the prediction of damage behaviour and residual strength within the scope of a damage tolerance assessment is decisive. Sufficiently precise and robust methods for the evaluation of a progressive damage are still missing for fiber reinforced plastics (FRP). Therefore, the damage initiation is usually utilized to determine the load-bearing capacity, which results in a conservative design [1]. The key challenge of the analysis of FRPs in comparison to metallic materials consists in the heterogeneity of the material which results in complex failure mechanisms [2]. A simulation method for the strength assessment has to take into account the damage initiation as well as the damage progression including all involved mechanisms and their interactions. The aim of the DFG project is the development of an improved damage assessment method for FRPs. The proposed solution is a new adaptive approach consisting of an interlink of the peridynamic methodology for potentially damaged parts of a structure with a FEM approach for undamaged regions. The objective of the approach is a significant improvement of the prediction accuracy of the load-bearing capacity of a structure which helps to develop more robust, safer and resource-conserving structures. The peridynamic theory is a promising method for analyzing the damage of homogeneous and heterogeneous materials [3], [4]. But, the application of the peridynamic approach for undamaged regions requires an unnecessary high effort for receiving sufficient accurate results [5], [6]. In contrast, the FEM as a classical continuum mechanics based approach is very efficient, if continuous stress distributions can be assumed and finite elements with higher shape functions (p-elements) are applied [7], [8]. A coupling of a peridynamic based simulation method with the FEM will result in a robust and efficient methodology to predict the damage initiation and the damage progress in specified (critical) regions [9], [10]. This approach also allows the modelling of the feedback of a damage region to the undamaged area of a structure. In the project the peridynamic will be extended to model damages in anisotropic FPR materials on an energy based damage approach [6]. For the coupling of the Peridynamik with the FEM a new coupling methodology will be developed, tested und implemented, e.g. based on the Arlequin method [12]. The software tools, developed in the proposed project will be freely-available as open-source software for other researchers in accordance with the DFG objectives of sustainability of research software in the context of the DFG program "e-Research Technologies¿.

[1] Gross, D., Seelig, T.: Bruchmechanik - Mit einer Einführung in die Mikromechanik. Springer Vieweg,
2018.
[2] Puck, A.: Festigkeitsanalyse von Faser-Matrix-Laminaten. Hanser, 1996.
[3] Silling, S.A., Lehoucq, R.B.: Peridynamic Theory of Solid Mechanics, Advances in Applied
Mechanics, 44 (2010), pp. 73-168.
[4] Madenci, E., Oterkus, E.: Peridynamic Theory and Its Applications, Springer 2014
[5] Willberg, C., Krause, D.: Peridynamic analysis of fibre-matrix debond and matrix failure
mechanisms in composites under transverse tensile load by an energy-based damage criterion,
Composites Part B: Engineering, Volume 158, February 2019, pp. 18-27.
[6] Willberg, C., Wiedemann, L., Rädel, M.: A mode-dependent energy-based damage model for
peridynamics and its implementation, J. Mechanics of Materials and Structures, Vol. 14, 2, 2019,
pp. 193-217.
[7] Szabó, B., Babu¿ka, I.: Finite Element Analysis. John Wiley & Sons, 1991.
[8] Willberg, C., Duczek, S., Vivar-Perez, J.M. Schmicker, D., Gabbert, U.: Comparison of different
higher order nite element schemes for the simulation of Lamb waves, Computer Methods in
Applied Mechanics and Engineering, 241-244 (2012), S. 246-261.
[9] Oterkus, E., Madenci, E., Weckner, O., Silling, S.A., Bogert P., Tessler, A.: Combined nite element
and peridynamic analyses for predicting failure in a stiffened composite curved panel with a
central slot, Composite Structures, 94.3 (2012), pp. 839-850.
[10] Galvanetto, U., Mudric, T., Shojaei, A., Zaccariotto, M.: An effective way to couple FEM meshes
and Peridynamics grids for the solution of static equilibrium problems, Mechanics Research
Communications 76 (2016), pp. 41-47.
For the design, evaluation and approval of safety-relevant lightweight structures, the prediction of damage behaviour and residual strength within the scope of a damage tolerance assessment is decisive. Sufficiently precise and robust methods for the evaluation of a progressive damage are still missing for fiber reinforced plastics (FRP). Therefore, the damage initiation is usually utilized to determine the load-bearing capacity, which results in a conservative design [1]. The key challenge of the analysis of FRPs in comparison to metallic materials consists in the heterogeneity of the material which results in complex failure mechanisms [2]. A simulation method for the strength assessment has to take into account the damage initiation as well as the damage progression including all involved mechanisms and their interactions. The aim of the DFG project is the development of an improved damage assessment method for FRPs. The proposed solution is a new adaptive approach consisting of an interlink of the peridynamic methodology for potentially damaged parts of a structure with a FEM approach for undamaged regions. The objective of the approach is a significant improvement of the prediction accuracy of the load-bearing capacity of a structure which helps to develop more robust, safer and resource-conserving structures. The peridynamic theory is a promising method for analyzing the damage of homogeneous and heterogeneous materials [3], [4]. But, the application of the peridynamic approach for undamaged regions requires an unnecessary high effort for receiving sufficient accurate results [5], [6]. In contrast, the FEM as a classical continuum mechanics based approach is very efficient, if continuous stress distributions can be assumed and finite elements with higher shape functions (p-elements) are applied [7], [8]. A coupling of a peridynamic based simulation method with the FEM will result in a robust and efficient methodology to predict the damage initiation and the damage progress in specified (critical) regions [9], [10]. This approach also allows the modelling of the feedback of a damage region to the undamaged area of a structure. In the project the peridynamic will be extended to model damages in anisotropic FPR materials on an energy based damage approach [6]. For the coupling of the Peridynamik with the FEM a new coupling methodology will be developed, tested und implemented, e.g. based on the Arlequin method [12]. The software tools, developed in the proposed project will be freely-available as open-source software for other researchers in accordance with the DFG objectives of sustainability of research software in the context of the DFG program "e-Research Technologies¿.

[1] Gross, D., Seelig, T.: Bruchmechanik - Mit einer Einführung in die Mikromechanik. Springer Vieweg,
2018.
[2] Puck, A.: Festigkeitsanalyse von Faser-Matrix-Laminaten. Hanser, 1996.
[3] Silling, S.A., Lehoucq, R.B.: Peridynamic Theory of Solid Mechanics, Advances in Applied
Mechanics, 44 (2010), pp. 73-168.
[4] Madenci, E., Oterkus, E.: Peridynamic Theory and Its Applications, Springer 2014
[5] Willberg, C., Krause, D.: Peridynamic analysis of fibre-matrix debond and matrix failure
mechanisms in composites under transverse tensile load by an energy-based damage criterion,
Composites Part B: Engineering, Volume 158, February 2019, pp. 18-27.
[6] Willberg, C., Wiedemann, L., Rädel, M.: A mode-dependent energy-based damage model for
peridynamics and its implementation, J. Mechanics of Materials and Structures, Vol. 14, 2, 2019,
pp. 193-217.
[7] Szabó, B., Babu¿ka, I.: Finite Element Analysis. John Wiley & Sons, 1991.
[8] Willberg, C., Duczek, S., Vivar-Perez, J.M. Schmicker, D., Gabbert, U.: Comparison of different
higher order nite element schemes for the simulation of Lamb waves, Computer Methods in
Applied Mechanics and Engineering, 241-244 (2012), S. 246-261.
[9] Oterkus, E., Madenci, E., Weckner, O., Silling, S.A., Bogert P., Tessler, A.: Combined nite element
and peridynamic analyses for predicting failure in a stiffened composite curved panel with a
central slot, Composite Structures, 94.3 (2012), pp. 839-850.
[10] Galvanetto, U., Mudric, T., Shojaei, A., Zaccariotto, M.: An effective way to couple FEM meshes
and Peridynamics grids for the solution of static equilibrium problems, Mechanics Research
Communications 76 (2016), pp. 41-47.
[11] Yang, D., He, X., Yi, S., Deng, Y., Liu, X.: Coupling of peridynamics with finite elements for brittle
crack propagation problems, Theoretical and Applied Fracture Mechanics, Volume 107, June
2020, 102505.
12] Barthel, C., Gabbert, U.: Application of the Arlequin Method in the virtual engineering design
process, PAMM, 10.1, 2010, pp. 141- 142.
2021-2024
Mittelgeber: Deutsche Forschungsgemeinschaft (DFG)
Development of high brightness quantum dot lasers for LIDAR light sources at 1250 nm
Novel semiconductor laser technology is on-demand for light detection and ranging (LiDAR) systems which are key safety components for autonomous driving assistance systems (ADAS). In LiDAR, light pulses are sent out omnidirectional and, once reflected from objects, are received by photodetection systems. Fundamentally, the system¿s scan speed depends on the laser power that is available at each measurement spot. Unfortunately, the light output from conventional semiconductor edge-emitting lasers is highly divergent along the vertical direction which not only reduces power density but also the possible resolution of the LiDAR system. Moreover, as these system operate in free-space eye safety regulations have to be obeyed. Current systems operate at non-optimum wavelengths around 905 nm since a mature semiconductor technology at the most attractive wavelength of 1250 nm has not been demonstrated so far. With this project, a Chinese and a German group team up for developing epitaxial growth and laser technology to cover this gap. Two recently patented novel concepts for high brightness edge emitting lasers, the HiBBEE laser, and the corrugated stripe laser will be combined with high-density quantum dot stacks and optimized for high-brightness, low-divergence 1250 nm laser emission. With these novel lasers higher resolution, faster scanning, and higher energy efficiency LiDAR systems will become available. In addition the complexity and cost of any of the potential optical ADAS systems when including these single mode lasers is dramatically reduced.
2021-2024
Mittelgeber: 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.
2020-2024
Mittelgeber: Deutsche Forschungsgemeinschaft (DFG)
Optimal Sampling Design for Big Data
Modern information technology allows for collecting hugh amounts of data both in terms of units (size) as well as in terms of variables (multivariate observations) which are frequently called "Big Data¿. However, the pure availability of Big Data does not necessary lead to further insight into causal structures within the data. Instead the sheer amount of data may cause severe problems for a statistical analysis. Moreover, in many situations parts (certain variables) of the data are cheap to obtain while other variables of interest may be expensive. Therefore prediction of the expensive variables would be desirable. This can be achieved by standard statistical methods when for a suitable subsample also the expensive variables are available. To reduce costs and/or improve the accuracy of the prediction there is a need for optimal sampling schemes. Concepts of optimal design theory originally related to technical experiments may be deployed in a non-standard way to generate efficient sampling strategies. Basic concepts like relaxation to continuous distributions of the data and symmetry properties may lead to substantial reduction in complexity and, hence, to feasible solutions. To make this general ideas more precise and to put them on a sound foundation to make them applicable to real data constitutes the aim of the present project.
2022-2024
Mittelgeber: Deutsche Forschungsgemeinschaft (DFG)
Coalescence of soap bubbles and gas bubbles in liquids and non-Newtonian fluids
Despite the significant importance of the coalescence of individual bubbles for the growth, structure and microscopic properties of foams, very few studies have dealt with the detailed fluid mechanics of the fusion of liquid films. These investigations will now be carried out.
When two soap bubbles are brought together, the liquid films of the bubbles deform at a small distance from each other: the bubbles form a dimple and thus enclose a tiny volume of air. At the crests of the dimple the distance between the bubbles is smallest, such that the liquid bridge can form there. The two individual films of the bubbles merge into a single one. The rim of the spreading film is accelerated for a short moment. During this time a Rayleigh-Taylor instability sets in which leads to an instability of the rim of the liquid film. The velocity of the rim is higher in the dimple area because the curvature in this area is greater. After coalescence, two bubbles remain which share a common film.
In this research project the fluid mechanics during the fusion of two Newtonian and non-Newtonian soap bubbles shall be experimentally recorded, described and compared with numerical models. The Rayleigh-Taylor instability occurs within one microsecond. The assumed wavelength of the instability is only a few micrometers. In order to achieve the above-mentioned goal, the spatial and temporal resolution of the experiment must be significantly improved: Among other things with a quasi-two-dimensional configuration of the experiment to enable the observation of instability from the side view (not as previously in a top view) as well as the use of an ultra-high-speed camera and a long-range microscope. At the same time, the experiments will be compared with external numerical models.
A further goal is to investigate the coalescence of gas bubbles in a soap solution, since so far only work in pure water or salty solutions has been carried out. The presence of surface-active substances will have a significant influence on the physics of coalescence in this system. Important information which will be obtained from the experimental work is the coalescence time of the bubbles as a function of their collision velocity and the Weber number as well as the coalescence time as a function of the viscosity ratio between bubble and soap solution (with Newtonian and non-Newtonian liquids). For this purpose, a suitable method shall be established to determine the beginning of the interaction of the bubbles. In addition, the approach velocity of the bubbles must be accurately determined to allow a quantitative comparison with the simulations.
2021-2024
Mittelgeber: Deutsche Forschungsgemeinschaft (DFG)
The impact of using AI-powered technology for lie detection in negotiations
The increasing digitization of social and economic interactions is proceeding at a considerable speed. Research on digitization processes should reconcile two areas of knowledge, which are usually examined separately from each other: First, the question of technical development and second, the question of the effects of this development on human behavior. In the project applied for, an attempt will be made to combine both perspectives in an interdisciplinary approach, whereby the focus is on behavioral analysis, but the technical components are nevertheless strongly represented. The use case chosen for this type of analysis of digitization processes is the phenomenon of asymmetric information. Specifically, we investigate to what extent the paradigm of asymmetric information has become at least partially obsolete through the use of AI technologies. In our interdisciplinary project, instead of waiting for technological developments in the field of AI-based lie detection, we would like to contribute to technological progress on our part, while experimentally investigating the possible social consequences of this technology.The project proposal combines two research areas: Economics (WW) and Neuro-Information Technology (NIT). In both fields, the identification of private information plays a major role, but is approached from different angles. While economic analysis focuses on the role and importance of private information in negotiation situations, NIT focuses on the feasibility and quality of automated recognition of personal characteristics.
2021-2024
Mittelgeber: 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.
2020-2024
Mittelgeber: Deutsche Forschungsgemeinschaft (DFG)
Creep behavior of advanced directionally solidified multi-phase Mo-alloys with and without coating (HTMA-DS Mo)
Mo-Hf-B and Mo-Zr-B alloys as a new class of refractory alloys are potential candidates in stationary and mobile turbine applications. Due to the high melting points of the constituents high-temperature strength and creep strength are expected up to 1,400 °C. Those high service temperatures, in turn, may result in higher turbine efficiencies and may reduce primary energy consumption.

As a manufacturing route, directional solidification via zone melting as a new processing approach for Mo-Hf-B and Mo-Zr-B results in low oxygen (< 50 ppm) impurities, which is essential to avoid embrittlement of these alloys; moreover the materials possess an anisotropic lamellae-reinforced microstructure.
2021-2023
Mittelgeber: Deutsche Forschungsgemeinschaft (DFG)
Our aim is to develop new processing concepts for exploiting the special characteristics of hardware accelerators in heterogeneous system architectures for classical and non-classical database systems. On the system management level, we want to research alternative query modeling concepts and mapping approaches that are better suited to capture the extended feature sets of heterogeneous hardware/software systems. On the hardware level, we will work on how processing engines for non-classical database systems can benefit from heterogeneous hardware and in which way processing engines mapped across device boundaries may provide benefits for query optimization. Our working hypothesis is that standard query mapping approaches with their consideration of queries on the level of individual operators is not sufficient to explore the extended processing features of heterogeneous system architectures. In the same way, implementing a complete operator on an individual device does not seem to be optimal to exploit heterogeneous systems. We base these claims on our results from the first project phase where we developed the ADAMANT architecture allowing a plug & play integration of heterogeneous hardware accelerators. We will extend ADAMANT by the proposed processing approaches in the second project phase and focus on how to utilize the extended feature sets of heterogeneous systems rather than how to set such systems up.
2020-2023
Mittelgeber: 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.
2021-2023
Mittelgeber: 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.
2021-2023
Mittelgeber: Deutsche Forschungsgemeinschaft (DFG)
Patterning valence specific amygdala memory by dorsal tegmental area (DTA) and ventral tegmental area (VTA) dopamine (DA) subsystems.
2021-2023
Mittelgeber: Deutsche Forschungsgemeinschaft (DFG)
Experimental and numerical OPtimization of a cross-flow TIDal turbinE (OPTIDE)
2017-2023
Mittelgeber: Deutsche Forschungsgemeinschaft (DFG)
PROTHOR: A randomized controlled trial
2021-2023
Mittelgeber: Deutsche Forschungsgemeinschaft (DFG)
Cell death dependency of Leishmania exit from infected macrophages
In order to establish infection and persist as a parasite population in the host, Leishmania major (L. major) has to undergo cycles of infection, intracellular proliferation, and transit to new host phagocytes. Therefore, the exit from an infected primary host cell and uptake by new, secondary infected cells are central to the parasite¿s lifestyle in the infected patient. However, the underlying cellular and molecular mechanisms have remained elusive. Live cell imaging suggests that parasites leave damaged host macrophages by parasitophorous extrusions, and that the exit is closely connected with cell-to-cell transfer. Our preliminary work also reveals that macrophages appear to sense amastigote membrane proximity and phagocytose parasites from infected cells. Consequently, we hypothesize that cell death induction is a central mechanism underlying both the exit of L. major from infected host cells and uptake into new host cells. Furthermore, a high proliferation rate of has been observed in parasites shortly before cell-to-cell transfer, thus, the physiological state of L. major might affect cell death induction.
Consequently, in this project we will focus on the link between cell death induction and parasite proliferation with L. major exit. By the combination of both human and mouse live cell imaging, flow cytometry quantification of the exit process and intravital 2-photon imaging of the site of infection in a mouse model, we expect to identify cellular and molecular mechanisms involved in this fundamental process crucial for Leishmania persistence, propagation and pathogensis.
Specifically, we will (1) elucidate in vitro and in vivo the possible modes of cell death associated with L. major exit and transfer to new host cells, (2) manipulate the identified candidate cell-to-cell transfer mechanisms in order to prevent the exit and dissemination of the parasite in vitro and at the site of infection, and (3) identify candidates of the L. major secretome/proteome within the infected host cell which are linked to high pathogen proliferation, the induction of host cell death, and parasite exit.
With the characterization of the host cell death pathways and parasite factors associated with the induction of L. major exit, the proposed research should identify unrecognized virulence elements critical for pathogen survival and propagation in the host, and thus reveal on both the host and the pathogen side new important molecular targets for treatment of infection.
2019-2023
Mittelgeber: Deutsche Forschungsgemeinschaft (DFG)
Targeting perisynaptic ECM mediated synaptic dysfunction in cerebral small vessel disease
2022-2023
Mittelgeber: Deutsche Forschungsgemeinschaft (DFG)
Transition metal-nitride-AlGaN layers for electronic applications by sputtering epitaxy
To further enhance GaN power electronics and enable new device
structures as well as device designs we will investigate transition
metal based nitrides and their alloys as well as their alloys with AlN
and GaN. This with the goal to enable true vertical electronics on low
cost silicon substrates and lateral enhancement-mode high electron
mobility transistors (HEMT) allowing for higher current densities and,
therefore more compact device size. In addition we will apply a new
growth method, pulsed sputtering epitaxy, which is capable of growing
high quality GaN layers at temperatures below 800 °C and thus offers
a huge potential for Si CMOS integration of GaN electronics. To
identify new materials suited to achieve conducting buffer layers for
subsequent GaN epitaxy as well as to achieve new or better
functionalities of group-III-N based devices we will investigate
transition metal (TM) nitrides also alloyed with AlN and GaN for their
potential in group-III-nitride electronic applications. For this we will first
study the properties of pure and alloyed group-IIIb -IVb and -Vbnitrides
(Cr, V, Ti, Sc, Nb, Zr, Ta, Hf) with AlN and in some cases also
with GaN. Our goal is a database on crystal structure, lattice
parameter, electrical and optical properties for a wide range of
compositions. In detail the potential will then be investigated for thin
films for applications as active layer in electronic devices, e.g. for
polarization optimization in HEMTs, novel HEMT structures with, e.g.
binary, highly conducting GaN/ScN/GaN channels, as thicker highly
conducting film, or as electrically conducting strain engineering layer,
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. Based on the properties of TMNs
known to date, we expect that fully vertical devices on Si as well as
better HEMT devices are achievable which will primarily result in a
further increase in power density of GaN based devices.
2020-2023
Mittelgeber: Deutsche Forschungsgemeinschaft (DFG)
Filled Polar Liquid Crystals from Umbrella-Shaped Mesogens
The work group (WG) Lehmann (Würzburg) synthesizes star mesogens on the basis of a subphthalocyanine core with conjugated arms (oligothiophenes, benzothienobenzothiophenes, thienylpyrrolopyrrolthiophenes) decorated with aliphatic chains. The latter induces columnar liquid-crystalline (LC) phases. The photophysical properties are studied in solution and thin films. The thermotropic behavior and the structure of the mesophases will be investigated by means of polarized optical microscopy, differential scanning calorimetry, X-ray scattering (WAXS, SAXS, GISAXS) and the modelling with the program Materials Studio. The umbrella-shaped, semiconducting mesogens form polar phases, for which an anomalous photovoltaic effect in thin, aligned films is expected. Therefore, alignment of the materials will be studied with a number of methods (different surfaces, magnetic and electric fields) in the WG Eremin (Magdeburg). The polar properties will be studied will be investigated by means of dielectric spectroscopy, second harmonic generation and the piezoelectric effect. On the thin oriented, polar films, the anomalous photovoltaic effect will be tested. These materials should exhibit a photocurrent without the need of a donor-acceptor (p/n) junction.
The result regarding the phase transitions, transition temperatures, alignment and the photocurrent will be considered to optimize the LC materials by synthesis. Moreover, the WG Lehmann will prepare star mesogen derivatives, for which the conjugated arms are tethered to fullerenes (C60) via flexible spacers with different spacer length. These molecules are sterically overcrowded and do not form LC phases. The original star mesogens without fullerenes possess between their arms intrinsic free space, which can host C60. Consequently, the mixture between these molecules with the sterically overcrowded fullerene derivatives results in new, polar, highly ordered, columnar donor-acceptor LC phases. These are filled mesophases, which will be thoroughly investigated in the WG Lehmann and Eremin with respect to their structure-property relationships, i.e. the mesophase structure, photophysical and polar properties, alignment, charge carrier mobilities with the Time-Of-Flight method and the photovoltaic properties. The latter will be studied by means of an inverted device structure in collaboration with a Japanese expert (Dr. Araoka, Tokyo). The filled liquid crystals are new donor-acceptor materials, which allow the control of the morphology and the alignment between electrodes. The polar properties will facilitate charge separation. The joint, multidisciplinary project of the WG Lehmann and Eremin will result in a new generation of liquid-crystalline, polar semiconductor materials, which allow the application in organic photovoltaics.
2019-2023
Mittelgeber: Deutsche Forschungsgemeinschaft (DFG)
Antifungal T-cell responses of neonates, infants, and children
T-cell immunity efficiently protects the organism from the onslaught by pathogens, including bacteria and fungi, but bears inherent risk of collateral damage and immuno-pathology. Therefore, tight control of T cells, the decision-makers of the adaptive immune response, is necessary. The challenge to balance protection against pathogens without harming the body itself is especially important for neonates and infants. And indeed, neonates and infants, in particular pre-term babies, and young infants are at significant higher risk of serious infections than adults are. Currently, too little is known about age-related human T-cell differentiation and capacity for defense against pathogens to understand this phenomenon. In the present project, we aim to identify peculiarities of fungus-specific immune responses in neonates, infants and children in order to better understand them.
2019-2023
Mittelgeber: Deutsche Forschungsgemeinschaft (DFG)
Functional characterization of cysteine residues in the regulation of Zap-70 activity in physiology and disease
2020-2023
Mittelgeber: Deutsche Forschungsgemeinschaft (DFG)
Dynamic properties of anisotropic magnetic fluids
In recent years, soft multifunctional materials became the focus of intensive scientific research. They open new avenues for designing smart devices responsive to various electric, magnetic, mechanical and chemical stimuli. Magnetic nanocomposite materials based on liquid crystals are very promising systems since the liquid crystalline structure can stabilise the magnetic order. It was demonstrated that such materials are capable of exhibiting even a spontaneous magnetic order forming "fluid ferromagnets¿.

The principal objective of our proposal is to understand the dynamics and self-assembly mechanisms in anisotropic fluids exhibiting magnetic order. In particular, we intend to explore the effects of the coupling between the magnetic and the orientational degrees of freedom, between hydrodynamic flows and the magnetisation in bulk and in confined and chiral environments, respectively. Such couplings affect both magnetic and optical responses of the nanocomposite magnetic materials. As an anisotropic matrix, we shall consider either a liquid crystal or a self-assembled colloidal liquid crystal of magnetic nanoparticles. Our proposal is largely based on the results of our collaborative research in the frame of DFG Priority Program 1681 "Field controlled particle-matrix interactions: synthesis multi-scale modelling and application of magnetic hybrid materials¿. Three kinds of systems will be in focus of the current studies: ferronematics, LC-based ferromagnetic nematics and colloid-based ferromagnetic nematics. In our proposal, we intend to explore the collective modes in response to oscillating and rotating magnetic fields and to understand how these modes affect the optical behaviour, flow and dynamics of magnetic particles. The novelty of our proposal lies in focusing on the magnetic dynamics: we propose to employ various experimental techniques such as AC susceptibility and rotating magnetic field measurements as well as magnetorelaxometry for studying magnetic dynamics. These measurements complement the magneto-optical studies in rotating/oscillating magnetic fields, measurements of the magneto-mechanical conversion in a rotating magnetic field utilising a torsional pendulum. This will allow a direct comparison between the relaxation modes and the mechanical response. Furthermore, we shall explore the role of interfacial anchoring on the structure and dynamic properties of ferronematics and ferromagnetic nematic materials. The output of this project will provide a detailed understanding of the magnetic and magnetooptical dynamics in an anisotropic matrix with orientational order.
2021-2023
Mittelgeber: Deutsche Forschungsgemeinschaft (DFG)
Synchronization emergence in manufacturing systems and its effect on logistic performance
2017-2023
Mittelgeber: Deutsche Forschungsgemeinschaft (DFG)
Agar-based gel-electrolytes for corrosion diagnostic
2017-2023
Mittelgeber: Deutsche Forschungsgemeinschaft (DFG)
Simulating by DNS the nanoparticle production in a spray flame
2020-2023
Mittelgeber: 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 (c) maternal behavior and/or (d) via the maternal germline.
2019-2023
Mittelgeber: Deutsche Forschungsgemeinschaft (DFG)
Impact of stress on aging of BDNF-dependent synaptic and cognitive functions
During aging many biological and environmental processes contribute to the functional
decline of cells. However, the mechanisms how this aging is reflected on the level of altered
synaptic plasticity is unknown. Interestingly, there is a wide heterogeneity in the pace of
aging in human and animal populations (Foebel, Pedersen, 2016). One factor that likely
contributes to accelerated aging processes is the exposure to adverse environmental events
in early and/or later life (Gassen et al., 2017). There is strong evidence that stress-induced
3 Research Program RTG SynAGE
31
Figure 12: A: Heterozygous BDNF knockout animals exhibit an age-dependent deficit in spatial learning. B: The
abundance of signaling-competent TrkB receptors declines with aging. C: BDNF protein expression declines in
different areas with aging.
alterations in BDNF expression contribute to long-lasting cellular and functional alterations in
the hippocampal network (Bath et al., 2013). Stressful events alter spine densities in areas
CA3 and CA1 of the hippocampus (Duman and Duman, 2015) and result in long-lasting
reductions in BDNF protein expression (Lakshminarasimhan and Chattarji, 2012). Since
BDNF is a key mediator of synaptic plasticity and exerts neuroprotective functions, reduced
BDNF levels and subsequently altered activation of downstream signaling molecules (Panja
et al., 2014) might be a key mechanism for accelerated aging of synaptic transmission. We
recently observed a decline of brain BDNF levels and abundance of signaling-competent
flTrkB receptors in aged WT mice (Petzold et al., 2015). In BDNF+/- mice this additional agedependent
decline leads to deficits in hippocampus- and amygdala-dependent learning
processes (Psotta et al., 2013; Endes and Lessmann, 2012; see Figure 12).
However, the mechanisms how BDNF and its downstream signaling molecules are involved
in these processes are widely unknown, thus limiting the exploitation of its possible therapeutic
potential against such aging processes. Identifying altered signaling events and protein
interaction partners downstream of TrkB activation are likely to provide novel approaches to
reverse stress-induced changes that result in accelerated aging.
2019-2023
Mittelgeber: Deutsche Forschungsgemeinschaft (DFG)
DNS and Visual Analysis of Superstructures in Turbulent Channels with Mixing by Parallel Injection
In order to analyze the occurrence and the impact of superstructures on
turbulent mixing in channels at high Reynolds numbers with a parallel injection,
a combination of Direct Numerical Simulation (DNS), vortex
definition and identification, and feature-based visualization, is
proposed. Standard, off-the-shelf solutions are not available for this
purpose.
Concerning DNS, the central issue is to access high Reynolds numbers
with excellent efficiency on HPC systems. Additionally, suitable
models must be included to describe numerically all fluid
properties relevant for mixing.
The main challenge in vortex extraction is three-fold. Firstly,
high-intensity turbulence excludes standard vortex definitions that are
based on a local analysis of the flow derivatives. Instead, global,
Lagrangian, or hierarchical vortex definitions are necessary that are
based on filtering operations on the flow map instead of the velocity
field. Secondly, vortex definitions and parameter tuning has to be
adapted such that it does not focus on upstream vortices
close to injection but tackles the less obvious, noisier
and more unsteady vortex structures downstream. Thirdly, in terms of
visual analysis, the main challenge is associated with the sheer size of
the data sets: DNS typically delivers data sets that cannot be
completely stored during the simulation. Hence, on-the-fly solutions for
the visual analysis are necessary.
To analyze the phenomena, DNS, vortex extraction and visualization have
to be combined into a feedback cycle in a computational steering sense.
While a multi-scale POD along with an automatic vortex extraction is carried out
on-the-fly, the resulting vortices are later visually analyzed in an interactive manner,
allowing adaptation of both the visualization parameters and further simulation
parameters. This efficient combination of DNS, POD, and visual analysis shall allow the identification of superstructures and help explain their impact on transport processes.
2019-2023
Mittelgeber: Deutsche Forschungsgemeinschaft (DFG)
Female Scientists Network FSN - Magdeburg connects life-scientists and alumnae
The Female Scientists Network invites all female scientists connected to Magdeburg to join. It doesn't matter whether Magdeburg was the starting point, an intermediate stop or the goal of your career.

The task of our network is to connect alumni and currently in Magdeburg working scientists, to win them as role models or mentors for future junior scientists and to highlight various career paths inside and outside academia.
Funded by: RTG 2413, RTG 2408, CRC 854
2019-2023
Mittelgeber: Deutsche Forschungsgemeinschaft (DFG)
RTG 2413: The aging synapse
Coordination of the research training group RTG 2413. 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.
2019-2023
Mittelgeber: Deutsche Forschungsgemeinschaft (DFG)
SynAGE Subproject 2: AUTOPHAGY MECHANISMS IN THE AGING HIPPOCAMPUS
Autophagy is essential for the maintenance of normal synaptic function. Increased autophagy has been observed under neurodegenerative conditions, but may also protect neurons from the toxicity of intracellular and extracellular aggregates.

In the brain ,autophagy is controlled by the mTOR signaling pathway, which is required for synaptic pruning during development and links autophagy to the state of metabolic activity. However, the routes that control autophagy and their effect on synaptic proteostasis in the aging brain have not been clarified so far.

A new regulator of these processes is the serine / threonine kinase Ndr2. NDR family kinases are involved in the control of proliferation and differentiation, as well as apoptosis signaling, and are known to play an important role in the development and function of the nervous system.

We postulate that Ndr2 is a novel and potent factor for controlling autophagy induction in the brain and can be used to regulate age-related autophagy deficits. In this project, we therefore investigate the effects of altered mTOR-dependent autophagic activity in the aging hippocampus on hippocampal physiology and hippocampus-dependent behavior. In addition, we use targeted molecular and pharmacological intervention to analyze the intracellular signaling pathways, in particular with regard to the role of the serine-threonine kinase Ndr2, and their potential as targets for therapeutic interventions.
2019-2023
Mittelgeber: Deutsche Forschungsgemeinschaft (DFG)
SynAGE TP10: HIPPOCAMPAL INTERNEURON CIRCUITS DURING COGNITIVE DECLINE
Local interneurons critically control activity and plasticity in the hippocampus during memory storage. Strikingly, aging in rodents has been associated with a loss of parvalbumin (PV) and somatostatin (SST) subclasses of hippocampal interneurons, in association with cholinergic dysfunction. Changes in these two cell populations likely contribute to the general alteration of GABAergic inhibition, altered excitation/inhibition balance and reduced capacity to modulate inhibition in the hippocampus of aged rodents. They may also account for disturbances in the propagation of gamma oscillations and altered timing of activity between CA3 and CA1. SST-positive interneurons of the hippocampus appear to be particularly vulnerable to age-related neuropathology and the loss of these interneurons in the hilus discriminates between good and bad memory performers during aging of rats.
The activity of both PV neurons and SST interneurons in the hippocampus are controlled by M1 muscarinic receptors, which in turn have been identified as a major target of pharmacotherapy in dementia and are downregulated in a mouse model of early senescence. In our work, we could recently demonstrate the role of a subgroup of hippocampal SST interneurons in the encoding of context memory salience and identified involved critical molecular components of these cells including the transcription factor CREB, neuropeptide Y and the M1 receptor.

We postulate that PV and SST interneurons mediate the consequences of cholinergic decline on synaptic aging in the hippocampus, and, thus, may serve as target sites for therapy and cognitive enhancement. We therefore in this project define the following aims:
    1. We investigate effects of long-term changes in the activity of interneurons and the networks they control on the composition and function of the excitatory synapses of the hippocampus.2. We specifically induce changes in the molecular components that control the activity of interneurons and hippocampal network function, with the aim of counteracting the loss of cognitive performance during ageing.
2020-2023
Mittelgeber: Deutsche Forschungsgemeinschaft (DFG)
Smectic freely suspended films under microgravity conditions
2020-2023
Mittelgeber: 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 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.
2019-2023
Mittelgeber: Deutsche Forschungsgemeinschaft (DFG)
The ageing synapse - molecular, cellular and behavioral underpinnings of cognitive decline.
Aging and cognitive decline are highly correlated in the elderly population even in the absence of neurodegenerative diseases. Despite the high burden for each individual and the society as a whole the molecular, cellular, and behavioral underpinnings of cognitive decline are barely understood. We concentrate on synaptic dysbalances involving (i) altered synaptic proteostasis and (ii) altered functionality of the multipartite synapse accompanied by (iii) dysfunctions of the immune system and (iv) changes in neuromodulation as the core for cognitive decline. SynAGE will address these four transversal themes in a joint effort by a team of molecular/cellular and systems neurobiologists to eventually break ground for innovative intervention strategies.
2020-2023
Mittelgeber: 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.
2019-2023
Mittelgeber: Deutsche Forschungsgemeinschaft (DFG)
Coupled Storage System for Efficient Management of Self-Describing Data Formats
Over the last decades, societies came to rely more than ever on technological progress in information technology. Especially in the area of scientific research, this does enable the possibility to solve increasingly complex problems, which nowadays require the computational power of supercomputers. The rising complexity of the processed problems as well as the growth of computation power leads to rapidly increasing data volumes; the globally produced data volume doubles approximately every two years, leading to an exponential data deluge. This imposes a serious problem as the development of the storage and network technologies is considerably slower. The result is a widening gap between the performance of computing and storage devices, resulting in a storage bottleneck. This is especially true for large-scale systems found in high-performance computing. To ease this situation, a hierarchy of different storage devices is used to suffice the demand for high capacity on the one hand and for high velocity as well as reliability on the other hand. By combining the advantages of different storage technologies, the overall performance is significantly increased while inducing lesser costs for acquisition, operation and maintenance. However, for future exascale systems, the difficulties will get even worse, requiring critical improvements in order to exploit the systems' capabilities. The existing input/output (I/O) stack leads to additional performance and management issues.
The produced data is typically stored using self-describing data formats to facilitate exchange and analysis within the scientific community. The project goal is to explore the benefits of a coupled storage system for these formats. It will introduce a novel hybrid approach leveraging storage technologies from the fields of high-performance computing and database systems, where each technology will be used according to its respective strengths and weaknesses. By coupling the storage system tightly with self-describing data formats, it can make use of structural information for selecting appropriate storage technologies and tiers. As such information is currently not available, storage systems have to employ heuristics, which often lead to suboptimal performance as well as unnecessary and expensive data movements. Moreover, the storage system will support adaptable I/O semantics to tune its performance according to application and data format requirements. Together, these features will enable completely new data management methods and provide significant performance improvements. Existing workflows of scientific users will be supported through a dedicated data analysis interface. All changes will be thoroughly tested to ensure backwards compatibility with existing applications and interfaces. Consequently, no modifications will be necessary to run applications on top of CoSEMoS, which helps preserve past investments in scientific software development.
2019-2023
Mittelgeber: Deutsche Forschungsgemeinschaft (DFG)
Interaction of ILCs and neurons during homeostasis and neuroinflammation induced during Toxoplasma gondii
The close interaction between the immune and nervous systems has been the focus of research for a long time. Previous studies have already revealed that the innate lymphoid cells (ILCs) located in the intestinal tissue are influenced by various neural signals. Nowadays, ILCs are recognized to play decisive roles during homeostasis as well as during inflammatory processes. More recently, ILCs have also been shown to be present in the central nervous system (CNS), in the immediate vicinity of the blood-brain barrier, and are thus involved in the regulation of vascular integrity and neuroinflammatory processes. However, the exact communication pathways have not yet been sufficiently clarified.
In previous projects we have already been able to show that all ILC subpopulations are present in the healthy CNS and that their number increases significantly during neuroinflammation. Furthermore, we could show the close interaction between immune cells and the cells located in the CNS during toxoplasmosis and the subsequent neuroinflammatory response.
In this project we will further characterize the complex functions of the different ILC subpopulations and their interaction with neurons under both healthy and pathological conditions. The results obtained will contribute to a better understanding of the bidirectional communication between the immune system and the CNS both in principle and in the context of pathological changes.
2020-2023
Mittelgeber: 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.
2020-2023
Mittelgeber: Deutsche Forschungsgemeinschaft (DFG)
Theorems of Linear Elasticity extended to Gradient Elasticity and their Applications
The classical theory of elasticity is an integral part of the daily routine of engineers. It was placed on a firm theoretical foundation between the beginning of the 19th century and the mid-20th century. Its development can be considered complete. Unfortunately, its scope is limited: It is size insensitive, it contains singularities in the stresses and displacements when discontinuities appear in the boundary data, and can not include boundary and surface energies. Thus, it is limited to typical engineering applications. For the description of micro-components or phenomena in the micron- and nanometer range it is only partially suitable.

A natural extension of classical elasticity is the strain gradient elasticity, in which higher derivatives of the displacement field appear. It has been shown in numerous papers that the limitations of classical elasticity theory can be overcome with gradient expansion without blurring the usual separation between structure- and material properties, as is the case with alternative nonlocal theories. Unfortunately, it has not yet been possible to develop a complete solid foundation for gradient elasticity as it exists for classical elasticity theory.

This is not a purely academic matter. The increasing miniaturization of components and the targeted development of micro-structured materials require us to go beyond the classical theory of elasticity. Furthermore, by removing the singularities of classical elasticity, we are able to apply a number of criteria (e.g. fracture and flow criteria), which are usually formulated in the Cauchy stresses, also in the vicinity of boundary discontinuities. This significantly increases the applicability of the elasticity theory.

In this project, the well-established theoretical foundations of classical elasticity are to be expanded to strain gradient elasticity. For this purpose, a generalizing axiomatic theory has been worked out, about 2/3 of which have already been transferred to the gradient theory. We try to complete this transfer, which is the core of the work of the German project partner. The Russian project partner is concerned with specific applications. For example, uniqueness theorems for boundary value problems with pure displacement or pure stress boundary conditions are applied in homogenization. With them, for example, the Eshelby fundamental solution of an elliptical inclusion in an infinite matrix can be extended. Another application are transversely isotropic fiber-reinforced composites, for which both a scale transition and the specific properties of the stiffness tensor are to be investigated. Finally, the de Saint-Venant principle for gradient elasticity will be investigated in beam experiments.
2020-2023
Mittelgeber: Deutsche Forschungsgemeinschaft (DFG)
Gait control - visuo-motor interactions and plasticity in glaucoma
Unsteady gait is a cause of increased incidences of falls and reduced mobility in the elderly, and is thus a source of a significant reduction in quality of life. A critical factor of gait control constitutes, apart from the motor- skills themselves, the interplay of the motoric system with both sensory and cognitive processes. This renders elderly with sensory impairment particularly prone to falls. Important examples are persons with glaucoma, a prevalent disease causing substantial visual impairment. An understanding of the role of visual, cognitive and visuo-cognitive functionality and their interactions during gait control is expected to pave the way for efficient interventional instruments to improve gait control in glaucoma and beyond. This prompts the question, whether multimodal movement-related interventions, i.e., those addressing motor-, sensory, and cognitive functions in a combined manner, are superior to unimodal movement-related interventions in their effect on gait control.
Our project aims to understand the interplay of motor-, visual, cognitive and visuo-cognitive function during gait control and its impact on the development of interventional instruments. It addresses glaucoma as an important and relevant model for risk groups with sensory impairment. In a multidisciplinary approach the project combines expertise in physical-activity and movement sciences, ophthalmology and neurosciences to address the following steps: (i) Development of research tools to identify interactions of visual function, cognition, visuo-cognition and gait control for both laboratory settings and, importantly, everyday like conditions. (ii) Application of these tools in =50 participants with glaucoma and matched controls to uncover and understand the relative importance of visual function, cognition, and visuo- cognition for gait control. (iii) Comparison of two interventional concepts, a unimodal and a multimodal movement-related intervention, in a longitudinal design in two glaucoma intervention groups, comprising a total of =50 participants. Behavioural readouts of the intervention effects will be combined with physiological correlates from resting state fMRI, to uncover mechanisms of neuro-plasticity and their correlation with behavioural measures. This will target changes in functional connectivity between brain regions representing motor skills, vision and cognition.
We expect this investigation of the interaction of cognition, vision, and visuo- cognition in gait control in glaucoma and matched controls to considerably increase our understanding of gait control and to guide the identification of efficient interventional concepts for prevention and rehabilitation in general.
2018-2023
Mittelgeber: Deutsche Forschungsgemeinschaft (DFG)
Normoxic HIF stabilization at the vascular barrier in atherosclerosis
Hypothesis: We hypothesize that proatherogenic micromilieu factors induce normoxic HIF stabilization, leading to molecular fixation of atherogenic maladaptation and loss of EndoC barrier function.

Aims 
  1. Systematic analysis of the effect of atherosclerosis-associated micromilieu factors on HIF-1a stabilization under normoxic conditions using a HCS with subsequent imaging-independent verification
  2. Functional characterization of HIF stabilizing agents with regard to barrier function and modulation of the EndoC secretome

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