Humboldt-Universität with participation in Collaborative Research Centres
Humboldt-Universität as co-applicant
Collaborative Research Centres
CRC-TRR 154: Mathematical Modelling, Simulation and Optimization Using the Example of Gas Networks
In recent years, ambitious climate protection initiatives have been presented in Germany. To make the transition to renewable energy sources possible, not only does infrastructure need to be newly built or repurposed, it also requires modernization and efficient operation of the grids. In the transformation to a climate-neutral energy system of the future based on electricity and (green) hydrogen, natural gas will continue to play a significant role for a long time, for (geo)political as well as security and supply reasons. In particular, hydrogen infrastructure will build on existing gas grid capacity. In addition, it is expected that hydrogen will increasingly replace gas as an energy carrier in applications and thus the transitions to climate neutrality will take place smoothly. CRC 154 set out to do just that with the analysis of gas networks, knowing fully well that deep and new mathematical insights in the context of mathematical modeling, simulation, and optimization as well as the links between them are necessary to answer the questions at the core. In doing so, we kept in mind that, in addition to researching the underlying mathematical theories, transferring to, and using these theories in a real-world context requires a corresponding lead time. Thus, outstanding new insights have been gained in the past years and especially in the last period, in which more dynamic aspects, the handling of uncertainties as well as the interrelation to gas trading and especially deregulated energy markets have been considered. The findings achieved in CRC 154 are the result of intensive, cooperative collaboration and research. The structures that CRC 154 set up and established have since become models for other larger research collaborations within and outside the university. They include cooperation in teams, in which scientists reflect the CRC 154’s findings in their discipline and deepen them there, the formation of subareas, in which scientists of different disciplines work on the coupling of the fields, as well as the consideration of demonstrators, each of which addresses problems relevant to practice, which cannot be treated by one mathematical discipline alone and thus require interdisciplinary cooperation. CRC 154 is on an excellent path to achieve and complete its initial goals, such as the development and mathematical analysis of a well-founded hierarchy of models including error analysis or the coupling of integer and continuous models and methods for decision making with inherent incomplete or uncertain information. In the following years, the goal is to raise these methods and models and their couplings to the current challenges of energy transition to a new level of quality using the existing and developed mathematical competencies. The simultaneity of the questions in the energy context paired with the inner-mathematical challenges inspires the fascination to work in this complex of topics and lets expect promising and new deep insights.
Coordinating University:
Friedrich-Alexander-Universität Erlangen-Nürnberg
Spokesperson:
Prof. Dr. Frauke Liers
Participating Departments of Humboldt-Universität Berlin:
Faculty of Mathematics and Natural Sciences, Department of Mathematics
Duration: 07/14 – 06/26
Webpage: https://www.trr154.fau.de
CRC-TRR 175: The Green Hub: Central Coordinator of Acclimation in Plants
Plants constantly adjust (acclimate) to environmental changes, involving signalling and multiple genetic and metabolic changes. The chloroplast has emerged as a hub of acclimation, serving as both sensor and target of acclimation. The TRR175 brings together scientists from Munich, Kaiserslautern, Berlin/Golm and now Bielefeld, with outstanding expertise in the genetics, molecular biology, biochemistry and systems biology in the model species Arabidopsis, tobacco, Chlamydomonas, Camelina and now Chlorella. While in the first funding period, TRR175 focused on acclimation to cold, heat and high light, in the second funding period fluctuating light, drought and prolonged cold periods have been added. TRR175 has also targeted the role of the nucleocytosolic compartment in acclimation signalling. In addition, results from cyanobacterial adaptive laboratory evolution (ALE) experiments were successfully tested in plants. Quantitative experimentation pervaded the entire research network, providing a high level of synergy between physiological, biochemical and systems biology approaches. In the third funding period, we will also address acclimation in natural environments where multiple factors are changing. In Area A (Genetic Modulators), we will build on our finding that translation is critical for acclimation, particularly to cold, and investigate the role of phase separation, the spatial organisation of acclimation responses, and, in two new projects, acclimation to multiple environmental changes. In Area B (Metabolic Modulators), we will continue to identify modulators involved in redox regulation, transport processes and primary metabolism. In a new project, we will study the interaction between photoreceptors and acclimation and analyse structure-function relationships. In Area C (Signalling), we have found that biogenic and operational chloroplast signalling is strongly intertwined with acclimation pathways. A strong focus will be on nuclear transcription factors (TFs) as targets of chloroplast signalling, and on the interplay between the chloroplast unfolded membrane protein response and retrograde signalling. In Area D (Data Mining and Modelling), we will continue to model and reconstruct acclimation processes, integrate quantitative data to predict acclimation modulators, and extend this to TF networks in a new project. Our central scientific project Z1 will continue to bundle quantitative biology approaches and to pursue innovative projects. These include a new forward genetics tool (pamiR approach), a novel approach to improve photosynthetic acclimation (F2P2) and the extension of our ALE approach to green algae. For Camelina, we will generate several additional transgenic lines with improved carbohydrate and carotenoid metabolism. The expected results will help to unravel the complexity of acclimation and to address the challenge of effectively identifying genetic factors with high potential to ultimately improve acclimation in crops.
Coordinating University:
Ludwig-Maximillians-Universität München
Spokesperson:
Prof. Dr. Dario Leister
Participating Departments of Humboldt-Universität Berlin:
Faculty of Life Sciences, Department of Biology
Duration: 07/16 – 06/28
Webpage: https://www.tr175.bio.lmu.de
CRC-TRR 266: Accounting for Transparency
The Collaborative Research Center (CRC) TRR 266 “Accounting for Transparency” explores how accounting and taxation influence transparency and how transparency in turn affects society. Accounting generates and distributes financial as well as nonfinancial information about firms and other organizations to receivers such as employees, investors, customers, suppliers, and tax authorities. Taxation uses accounting and additional information to levy governmental income. Given their societal importance, accounting and taxation are subject to regulation. They affect transparency to the extent that they produce clear and accurate information that receivers are able to process and regulators are able to act upon. The CRC’s core research agenda is to understand the functioning, determinants, and consequences of this process. During the first funding period, the CRC produced a substantial body of research resulting in a large number of publications, working papers as well as other publicly available material such as data and code. This research has strengthened the CRC team’s priors that the transparency effects of accounting and taxation are highly context-specific. For example, investors process accounting information very differently and for different objectives than other receivers, such as employees. This discrepancy can lead to undesired economic outcomes. Moreover, regulation often fails to reach its societal objective. For example, companies often struggle to predict tax effects and, thus, take inefficient business decisions. Regulatory complexity creates loopholes, increases inequality, and challenges organizations and their stakeholders, including policymakers. Overall, the CRC concludes that while transparency can provide important societal benefits, it is not a panacea as often portrayed in the public debate. These findings as well as recent societal developments provide the inspiration to continue this research agenda by focusing on settings where traditional accounting and taxation practices do not work well. For example: How should firms communicate with consumers, employees, and corporate activists? How should taxation and accounting regulation be designed to promote a shift to a sustainable economy? How does accounting and transparency influence the agility and resilience of firms and institutions? And finally: When is transparency socially desirable, and when is it not? Furthermore, the CRC establishes the German Business Panel as an institution in economics and business research, promotes the idea of open science by sharing data and methods, and communicates the findings to a diverse audience (both academic and non-academic). Thereby, it aims to contribute to the development of well-designed regulations, substantiates the public debate, and enhances societal trust in research and the economic system.
Coordinating University:
Universität Paderborn
Spokesperson:
Prof. Dr. Caren Sureth-Sloane
Participating Departments of Humboldt-Universität Berlin:
School of Business and Economics
Duration: 07/19 – 06/27
Webpage: https://www.accounting-for-transparency.de
CRC-TRR 388: Rough Analysis, Stochastic Dynamics and Related Fields
Stochastic dynamics builds on probability theory and Itô’s stochastic analysis to study the evolution of systems under the influence of randomness, with a profound impact on many fields, including statistical physics, mathematical finance, uncertainty quantification, quantum field theory, mathematical biology, economics. Rough analysis, on the other hand, stands for recent breakthroughs in mathematics, rooted in Lyons’ rough path theory. With the original motivation of introducing robustness in noise/signal, rough analysis offers a nonlinear extension of distribution theory that is crucial for understanding singular stochastic dynamics and their possible renormalizations, and to capture nonlinear effects of signals. Transcending its origins, rough analysis recently saw the emergence of deep mathematical structures with significant geometric and algebraic components. Together, they form the fertile grounds for this TRR Rough Analysis, Stochastic Dynamics and Related Fields. With an intense interplay of analysis, algebra/geometry and probability theory together with closely related applied topics, such as statistics, robust modeling under uncertainty, and stochastic control theory and mathematical finance, our overarching goal is to foster mutually beneficial interactions with the new field of rough analysis. To achieve this we have identified the following central questions that will guide our investigations. (i) Singular Dynamics - How to approach long-term/large scale stochastic effects in singular dynamics? (ii) Robustification - How do complex stochastic systems depend on specified noise?(iii) How do we, and how should we, understand paths?(iv) What is the role of Markovianity in rough, stochastic and singular dynamics? Our answers to these overarching questions pass through outward-looking investigations of rough and stochastic (partial) differential equations (e.g. understanding universal objects in statistical physics, ‘KPZ fixed point’, robustness and uncertainty quantification, relations to optimal transport), the study of related algebraic structures for statistics and high-dimensional probability (e.g. rough path induced signatures), robust and efficient statistics for dynamically specified non-linear stochastic processes, as well as the emergence and use of rough structures in stochastic control theory and financial mathematics (e.g. rough volatility). The area of rough analysis has, to a large extent, progressed as a theory in its own right. With our motto “Repeat the success of Itô calculus!” we envision a future where these ideas profoundly influence the vast community of probability, including financial mathematics and statistics, and beyond. Our TRR team offers the ideal complementary scientific expertise and the firm commitment, through the development of new important applications and in combination with significant outreach work, to contribute substantially to this goal.
Coordinating University:
Technische Universität Berlin
Spokesperson:
Prof. Dr. Peter Karl Friz
Participating Departments of Humboldt-Universität Berlin:
Faculty of Mathematics and Natural Sciences, Department of Mathematics
Duration: 10/24 – 06/28
Webpage: https://sites.google.com/view/trr388
Humboldt-Universität as participant
CRC 1078: Protonation Dynamics in Protein Function
Central mechanistic principles of protein function, such as the lock-and-key principle in substrate binding, have been identified over the past decades. CRC1078 has proposed to put a further key principle into place, namely the control and coordination of complex protein functions by protonation dynamics. Spatio-temporal fluctuations of the functionally relevant hydrogen-bonded networks result from protonation dynamics, that is, the movement of protons on various time and length scales – from femtoseconds to seconds and from less than 0.1 to more than 10 nm. The experimental works are actively linked to theory and simulations to achieve a profound understanding of protonation-dependent mechanisms in the selected proteins. Different facets of protonation dynamics have been and will be studied in two central proteins involved in biological energy conversion: Oxygen reduction coupled to proton pumping in cytochrome c oxidase and water oxidation in photosystem II. The latter will be amended by a new project on protonation dynamics in photosystem I. Whereas larger structural changes are supposed to slow down or even obstruct electron transfer in proteins, light-induced conformational changes play vital roles in phytochromes and channelrhodopsins. These structural changes are associated with or even driven by protonation events. Based on the expertise of CRC1078 and the inclusion of new projects, we will extend the scope of research by investigating pH-gated proton channels that are involved in viral infection (viroporins). Therefore, we will transfer the developed methodologies and acquired knowledge on protonation dynamics to study this new class of ion channels in the next funding period. The development and adaption of various advanced methods to the requirements of the specific protein systems was and will be a major asset of this CRC1078, including the incorporation of non-canonical amino acids into proteins, time-resolved serial femtosecond X-ray crystallography using free electron lasers, nuclear magnetic resonance spectroscopy at high magnetic fields, time-resolved electronic and vibrational spectroscopies in a wide dynamic range, and multiscale computational approaches such as quantum-mechanics, molecular dynamics simulations and their hybrids. The application of such sophisticated techniques to the research agenda of the CRC is challenging as most of the proteins are integral membrane proteins.In conclusion, CRC1078 aims at the comprehensive understanding of protonation dynamics and their role in the function of the five selected proteins and to establish this process as a generic principle in protein function. Beyond the anticipated scientific success of CRC1078, the training of graduate students in this truly interdisciplinary field is particularly rewarding as a basis is generated for career development not only in academia but also for the employability in industry.
Coordinating University:
Freie Universität Berlin
Spokesperson:
Prof. Dr. Joachim Heberle
Participating Departments of Humboldt-Universität Berlin: Faculty of Life Sciences, Department of Biology
Duration: 01/13 – 12/24
Homepage: https://sfb1078.de
CRC 1265: Re-Figuration of Spaces
The Collaborative Research Center 1265 investigates current processes of the spatial reordering of society as a “re-figuration of spaces”. Conceiving of sociality as an essentially spatial phenomenon, it seeks to develop an empirically-based theory of contemporary social change that views social change as a form of processual, spatial-communicative refiguration.In the first funding phase, the CRC’s work focused on elaborating basic concepts of social theory related to the spatiality of society, and on empirically identifying the qualitative features of refiguration. This empirical analysis advanced an in-depth specification of the sensitizing concepts translocalization, mediatization and polycontexturalization. The CRC identified four socially dominant spatial figures: territorial space, network space, trajectorial space, and place.For the second funding phase, three key priorities have been outlined: Research will (1.) highlight the role of conflicts in processes of spatial construction, particularly in and between different spatial figures. This inherently conflict-theoretical focus is (2.) linked to an in-depth exploration of the phenomenon of polycontexturalization and the way it is subjectively managed. These empirical investigations include the task of identifying and differentiating new emerging spatial orders.Insights gained during the first phase have made it clear that though refiguration processes share certain similarities with regards to their qualitative features, there are also crucial differences resulting from tensions between the different spatial figures. Focusing on these similarities and differences, as well as the multiple interconnections between the spaces studied in widely different societies around the globe, the CRC will continue to systematically pursue its comparative perspective concerning (3.) multiple spatialities. Methodologically, this approach allows us to explore both social convergences and divergences of refiguration on different scales without having to ex ante identify the spaces under study as clearly demarcated or independent entities. The CRC thereby accounts for the – at times conflictual – plurality of spatial knowledges, spatial actions and spatial regimes in order to gain a more nuanced understanding of these concepts. In addition to qualitative methods used to study refiguration, the CRC will further expand its repertoire by incorporating more quantitative data and mixed methods research. By utilizing innovative combinations, such as panel data and spatial data, alongside novel mapping procedures, the CRC will continue to advance the task it set itself during the first funding period of developing methods of social-science-based spatial research. The successful interdisciplinary collaboration between scholars of sociology, geography, communication studies, planning studies, architecture and the arts will be carried forward. Anthropology represents a new addition to this interdisciplinary framework .
Coordinating University:
Technische Universität Berlin
Spokesperson:
Prof. Dr. Martina Löw
Participating Departments of Humboldt-Universität Berlin:
Faculty of Mathematics and Natural Sciences, Department of Geography
Faculty of Humanities and Social Sciences, Department of Social Sciences
Faculty of Arts and Humanities, Department of European Ethnology
Duration: 01/18 – 12/25
Homepage: https://sfb1265.de/en/
CRC 1294: Data Assimilation – The Seamless Integration of Data and Models
The seamless integration of large data sets into sophisticated computational models provides one of the central research challenges for the mathematical sciences in the 21st century. When the computational model is based on evolutionary equations and the data set is time-ordered, the process of combining models and data is called “data assimilation”. The assimilation of data into computational models serves a wide spectrum of purposes ranging from model calibration and model comparison all the way to the validation of novel model design principles. The field of data assimilation has been largely driven by practitioners from meteorology, hydrology and oil reservoir exploration. However, a theoretical foundation of the field is largely missing. Furthermore, many new applications are emerging from biology, medicine, and cognitive neuroscience, for example. These fields need novel data assimilation techniques. The goal of the CRC is therefore twofold: 1) to develop principled methodologies for data assimilation, and 2) to demonstrate the computational effectiveness and robustness of these methodologies, by implementing them in established and novel application areas. While most current data assimilation algorithms are derived and analysed from a Bayesian perspective, the CRC views data assimilation from a general statistical inference perspective. Major challenges arise from the high dimensionality of the inference problems, the nonlinearity of the models, or non-Gaussian statistics. Targeted application areas include the geosciences, as well as emerging fields for data assimilation such as biophysics, cognitive neuroscience, and pharmacology.
Coordinating University:
Universität Potsdam
Spokesperson:
Prof. Dr.-Ing. Sebastian Reich
Participating Departments of Humboldt-Universität Berlin:
Faculty of Mathematics and Natural Sciences, Department of Mathematics
Duration: 07/17 – 06/25
Homepage:https://www.sfb1294.de/
CRC 1349: Fluorine-Specific Interactions: Fundamentals and Functions
The aim of the CRC 1349 is to understand, control and apply the complex interactions that can arise from fluorinated groups in chemical systems and are denoted as Fluorine-Specific interactions. This includes systems with H∙∙∙F Interactions, with Acceptorcontrolled Properties, e.g., in fluorinated Lewis-acids, and Interactions with fluorous Systems such as those encountered between (per-)fluorinated alkane groups. Interactions on a molecu-lar scale differ significantly from collective interactions due to mutually influencing, non-additive effects that exist on surfaces or in liquid phases. Therefore, the investigated systems range from single molecules through various ensembles to condensed phases or interfaces. The CRC focuses on the influences of the investigated interactions on a wide range of physicochemical properties and chemical reactivities. This includes the effects of Fluorine-Specific interactions on the properties of functional materials, the mechanisms of catalytic processes, and the function of biochemical systems and pharmaceuticals. For this purpose, the comprehensive expertise of the working groups involved in synthesis/biosynthesis, analysis/spectroscopy, and theory/modeling is linked in a complementary and synergistic manner to establish an understanding of Fluorine-Specific interactions, their con-ceptual foundation, and their numerous consequences and to translate all these into functional systems.
Coordinating University:
Freie Universität Berlin
Spokesperson:
Prof. Dr. Sebastian Hasenstab-Riedel
Participating Departments of Humboldt-Universität Berlin:
Faculty of Mathematics and Natural Sciences, Department of Chemistry
Duration: 07/19 – 12/26
Homepage: https://sfb1349.de
CRC 1375: Nonlinear Optics down to Atomic Scales (NOA)
The interaction of light with matter commonly scales linearly with the incident light intensity, inducing weak excitations in the system. The processes occurring in the medium can often be described perturbatively within linear response with a classical, spatially homogenous field. For the light, the interaction is described to occur with an effective medium. However, these approaches cannot be invoked when reaching down to atomic scales: (i) with spatial dimensions of the system approaching the atomic scale, as is the case, for example, for low-dimensional and nanoscale structures, the description of an effective medium fails; (ii) at moderately higher light intensities, nonlinear optical processes occur; and (iii) processes involving the generation or interaction with single photons cannot be described with linear response theories. It is the aim of NOA to explore fundamental nonlinear optical processes of light-matter interaction reaching down to the atomic scale. To reach this goal, NOA combines theoretical research in area A with experimental research focusing on nonlinear optical processes in low-dimensional and nanoscale structures, nonlinear wave-mixing and single-photon nonlinear optical processes in research areas B and C. In the first funding phase, theoretical methods, methodologies, and numerical schemes have been developed and applied along the scientific questions in areas B and C. From the experimental side, two-dimensional systems such as crystalline 2D-materials (area B) but also lower-dimensional systems such as nanowires, nanoscale tips, nanoparticles, or quantum dots (area C) and their nonlinear interaction with light have been the focus of investigation. After having analysed and described these systems individually, NOA will investigate systems with mixed dimensionality in the prospective second funding phase: this includes chemically or electronically locally modified nanowires or sheets, nanowires attached to 2D-materials, local point defects and/or single photon emitters in 2D materials or atomically thin layered materials with the aim of tailoring the design of the nonlinear optical response. Incorporating novel research activities in the area of quantum optics in Jena, NOA will include two new projects investigating (nonlinear) optical processes down to the single photon scale in the second funding phase. Moreover, a new public outreach project devoted to science communication will enrich NOA, aiming at developing an attractive didactic concept for both the general audience and pupils of secondary schools. As a major disseminating platform, the Deutsches Optisches Museum will provide a unique environment for NOA science communication. With this combined approach, NOA will be able to establish new paradigms for nonlinear optics down to atomic scales, not only – but primarily – in terms of fundamental physics, but also towards applications.
Coordinating University:
Friedrich-Schiller-Universität Jena
Spokesperson:
Prof. Dr. Ulf Peschel
Participating Departments of Humboldt-Universität Berlin:
Faculty of Mathematics and Natural Sciences, Department of Physics
Duration: 07/19 – 06/27
Homepage: https://www.noa.uni-jena.de
CRC 1499: Dynamic Hydrogels at Biointerfaces
The overarching goal of this CRC is to define the key physicochemical parameters that determine protective hydrogel function at biological interfaces in health, and abnormalities in disease for prospective development of novel therapeutic strategies. To achieve this goal, we will perform a detailed analysis of the physical, chemical and biological properties of synthetic and native hydrogels (i.e. mucus and glycocalyx). We focus on the individual and combined contributions of hydrogel components and their functional impact on airway and intestinal surfaces constituting the largest biointerfaces covered by hydrogels in the human body. In this context, we will include studies of exemplary pulmonary and gastrointestinal diseases, in which abnormal hydrogels have been implicated as important determinants of pathogenesis. These examples include i) cystic fibrosis (mucoviscidosis) as a chronic muco-obstructive lung disease triggered by abnormal viscoelastic properties of mucus in the airways; ii) acute respiratory tract infections caused by bacteria and viruses; and iii) inflammatory bowel disease as chronic disease condition associated with abnormal mucus composition in the gastrointestinal tract. Our overarching approach will determine mucus properties and dynamics at the molecular level including structure, mesh size, charge conditions, viscoelastic and transport behavior, to determine which molecular parameters define healthy vs. disease states. We base the approach on our unique capability to (bio)synthetically build key hydrogel components and compare them with the native hydrogels. The three main research objectives of the CRC are i) to determine the structure and role of individual hydrogel components, i.e. glycoproteins, salt and water, in the complex process of hydrogel formation and its function at biointerfaces; ii) to reconstitute synthetic mimics of native hydrogel components and study whether the synthetic hydro-gel variants can recapitulate the native barrier to prevent infection by bacteria and viruses; iii) to define the relationship of hydrogel properties (mucus/glycocalyx) in health vs. disease to design new therapeutic concepts.
Coordinating University:
Freie Universität Berlin
Spokesperson:
Prof. Dr. Rainer Haag
Participating Departments of Humboldt-Universität Berlin:
Faculty of Mathematic and Natural Sciences, Department of Chemistry
Duration: 01/21 – 12/24
Homepage: https://www.sfb1449.de
CRC 1636: Elementary Processes of Light-Driven Reactions at Nanoscale Metals
Light-driven chemistry at nanoscale metals is an emerging, interdisciplinary research field. It is based on experimental and theoretical expertise ranging from nano-optics and condensed matter physics over physical chemistry to organic and inorganic chemistry. The vision is to not only control chemical reactions via the catalytic properties of nanoscale metals, but also to control and amend reaction paths so precisely that they may be activated by sunlight to enable sustainable technology. Chemical reactions that are amplified by coupling light into collective charge oscillations in the metal are known as "plasmonic chemistry", with controversial details such as the relevance of charge transfer and local heating in various reactions. Our research programme has two goals: We want to (A) develop a comprehensive, fundamental microscopic understanding of the primary processes that lead to light-driven chemical reactions at nanoscale metals based on a set of model systems. On the other hand, we want to (B) explore new chemical pathways based on plasmon-assisted chemistry with the long-term aim to establish new materials and new synthesis methods. The research activities in (A) therefore concentrate on elementary physical processes in model systems that form the basis for new chemical reactions (B) that take place at nanoscale metals. We focus on light-induced transformation of organic molecules, polymerisations and nanoparticle functionalization. With experiments and theoretical modelling we will investigate the elementary steps that make quantized photon energy usable for chemical reactivity: energetic electrons and holes generated by photo-excitation of the metal activate molecular bonds through charge transfer. At the same time, electronic energy is converted into vibrational excitations in the metal and its surroundings at the nanoscale. Phenomena such as hybrid light-matter states emerging through strong coupling and nanoscale heat transport including quantum effects are current challenges for experiments and modelling. Our arsenal of highly specific, ultrafast pump-probe techniques from mid-infrared to hard X-rays aims at recording the primary processes in their chronological sequence and elucidating them spectroscopically. Microscopy with atomic resolution and single molecule spectroscopy will help us to examine the reaction intermediates and products. Together we will develop and establish new plasmon-assisted synthesis schemes that enable light-induced selective and efficient chemistry. Our concentration of expertise provides an excellent opportunity to bring together researchers with strong backgrounds in chemical analysis and synthesis and characterising elementary processes. Timely interdisciplinary training across chemistry and physics will help to develop a modern view of light-driven chemistry based on modern methods of nanoscale control.
Coordinating University:
Universität Potsdam
Spokesperson:
Prof. Dr. Mathias Bargheer
Participating Departments of Humboldt-Universität Berlin:
Faculty of Mathematic and Natural Sciences, Department of Chemistry and Department of Physics
Duration: 04/24 – 12/27
Homepage: https://www.uni-potsdam.de/en/sfb1636
CRC 1644: Phenotypic Plasticity in Plants – Mechanisms, Constraints and Evolution
Plants have colonised almost every habitat on earth. They are the dominant organismal kingdom by biomass, and all animal life depends on them. A major feature that has enabled this success is the remarkable ability of plants to adjust their growth and development to different environments. The ability of a given genotype to generate different phenotypes in different environments is termed phenotypic plasticity. Such plasticity is a universal feature of life, and understanding its molecular basis and evolution is a fundamental goal in biology. This understanding has major implications for predicting plant responses to a changing climate and environment and for accelerating plant breeding tailored to specific environments. With our CRC, we propose an interdisciplinary research program to tackle this key challenge across multiple scales of biological organization. Genotypes can differ in how they respond to the same environmental cue, for example because of molecular differences in their environmental response machinery. Thus, the plasticity of a focal trait to an environmental cue is itself a heritable trait. At the same time, phenotypic plasticity is not unlimited, but is associated with costs and constraints. One important source of such constraints are genetic correlations between plastic responses of different traits. The magnitude and shape of plastic responses can be described by the reaction norm that relates the trait values of a given genotype to the values of the environmental cue. Previous work has both demonstrated ample variation in reaction-norm shapes, and elucidated the molecular mechanisms underlying plasticity to particular cues in model genotypes. However, these two fields of research are largely unconnected and we still know very little about what makes different genotypes respond differently to the same environmental cue? To address this overarching question, our CRC will tackle the following four common questions across the individual projects: (i) What is the genetic and molecular basis of variation in phenotypic plasticity of key traits to environmental cues in natural populations? (ii) How do the genes that influence the reaction-norm shape of a trait act mechanistically, and to what extent are these molecular mechanisms shared across taxa? (iii) Are there genetic correlations between the extents of phenotypic plasticity for different focal traits that constrain plasticity? (iv) Which type of natural selection acts on phenotypic plasticity of a focal trait, and is there evidence for recent positive selection on plasticity? To achieve these goals, our consortium will integrate genetics, cell and developmental biology, physiology, evolutionary biology, ecology, computational biology and mathematical modeling. As a result, we will obtain a step-change in our understanding of phenotypic plasticity as an evolving trait of critical importance to the fate of plant populations in the face of environmental change.
Coordinating University:
Universität Potsdam
Spokesperson:
Prof. Dr. Michael Lenhard
Participating Departments of Humboldt-Universität Berlin:
Faculty of Life Sciences, Department of Biology
Duration: 04/24 – 12/27
Homepage: https://www.uni-potsdam.de/en/ppp/
CRC 1665: Sexdiversity – Determinants, meanings and implications of sex diversity in sociocultural, medical and biological landscapes
The categorisation of sex and the relationship between sex and gender are among the most controversial aspects of our understanding of the human body. Recently there has been substantial criticism by both the humanities and the biological sciences of an exclusively binary and essentialising model of sex. Thus, a starting point for new research is the observation that sex is multi-layered, dynamic, and in need of context-dependent reference frames. In this CRC, we aim to define the diversity of sex in different research contexts. In the different layers of analysis – from cells to organs, from organisms to societies – and by characterising the determinants, meanings and implications of sex at each of these levels, we will specify what “sex” refers to. The CRC will enable us to address the central hypothesis that sex is diverse and manifests itself through context-dependent differences that emerge on multiple levels. We will use cutting-edge methodology from the natural sciences, the humanities and social sciences to generate new insights into the biology of sex diversification, the impacts of (biological) sex and (socio-cultural) gender norms on clinical practice and biomedical research, and the sociocultural formation of sex categories. The CRC brings together scholars, researchers and clinicians from the Universität zu Lübeck with strong expertise in their respective fields, and who have already collaborated on fundamental, translational and clinical aspects of sex-related research. They are complemented by experts from the Christian-Albrechts-Universität zu Kiel, with whom long-standing scientific and clinical collaborations exist. They are further complemented by selected external experts from Berlin, Flensburg, Magdeburg, Munich and Hannover with specific expertise in DSD research, gender studies and the legal aspects of sex diversity. The CRC will be organised in a way that stimulates interdisciplinary work between biological sciences, medicine, humanities and social sciences. Collaboratively, we will develop new research questions and understandings of sex diversity, and involve stakeholders and societal actors in the research process, thereby generating transdisciplinary impact. With the CRC, we hope to change the way sex is considered as a research variable in biomedical research and basic science by providing definitions and reference frames for sex which are contextual and adequate for its complexity and multi-layered nature. This will lead to more accurate and differentiated understanding of sex and sex diversity and thereby provide a solid basis for personalised medicine. The contribution of the humanities and social sciences will be to deepen the understanding of the interaction of sex and gender, and support methodological reflexivity. The findings of the CRC will elucidate the determinants, meanings and implications of sex and sex diversity, which is of utmost societal relevance and at the very core of our self-concept as humans.
Coordinating University:
Universität zu Lübeck
Spokesperson:
Prof. Dr. med. Olaf Hiort
Participating Departments of Humboldt-Universität Berlin:
Faculty of Arts and Humanities, Department of History
Duration: 04/24 – 12/27
Homepage: https://www.sfb1665.uni-luebeck.de/sfb-1665
CRC/TR 384: Inhibitory neurons: shaping the cortical code (IN-CODE)
The brain enables us to feel, act, learn and remember, to process and store information with an effi-ciency and flexibility that by far surpasses any machine. At the same time, dysfunctions of the brain cause a number of devastating cognitive disorders. Cognitive functions depend on the cortex. Since ~80% of cortical cells are excitatory principal neurons (PNs), they have received greatest attention. This work revealed that even individual PNs represent significant information, such as place cells in the hippocampus or PNs in sensory areas tuned to stimulus features (single neuron code). Advances in large-scale recordings started to uncover how PNs combine to represent information at the popula-tion level (population code). However, the activity of PNs is markedly shaped by GABAergic inhibitory interneurons, a smaller but highly diverse class of cortical cells. Inhibition has recently emerged as an essential factor that plays complex roles in cortical networks. Indeed, through their great diversity and specific connectivity, interneurons can determine not only if, but also when and where individual PNs fire to encode information. Thus, the emerging picture suggests that, while PN assemblies sus-tain the information content, interneurons offer key mechanisms that sculpt the activity of neuronal subpopulations in space and time and thereby contribute to the process of information encoding in the brain. Driven by this hypothesis, the proposed CRC/TRR aims to investigate in what ways inter-neurons tune cortical network computations and thereby shape the cortical population code. Interneurons are characterized by diverse morphologies, molecular and synaptic properties, connectivities and activity profiles, and may tune cortical cods according to the changing computational demands. Using mouse models for genetic circuit dissection and human tissue, we will focus on a number of cortical areas, vital for higher brain functions. By combining state-of-the-art optical and electrical recordings with pharmaco- and optogenetic perturbation, quantitative behavior, computa-tional modeling, high-dimensional data analysis and deep learning, the proposed CRC/TRR will pro-vide multidisciplinary insights on a number of central questions in neuroscience: How do interneurons shape cortical codes in relation to experience? How do structural-functional interneurons properties contribute to encoding of information? How is the encapsulation of information in the neuronal population code controlled by interneurons? Addressing these questions critically depends on synergies between our members in terms of tools, methods, concepts, computational and translational integration. The proposed topic is timely as reflected by the continuous rise of related publications in high impact journals in the last 10 years. We strongly believe that our work will build a foundation on the role of interneurons in controlling encoding of behaviorally relevant information in cortical circuits.
Coordinating University:
Albert-Ludwigs-Universität Freiburg
Spokesperson:
Prof. Dr. Marlene Bartos
Participating Departments of Humboldt-Universität Berlin:
Faculty of Life Sciences, Department of Biology
Duration: 04/24 – 12/27
Homepage: https://sfb-trr384.de/