Auf dieser Seite finden Sie die chronologisch geordneten Veröffentlichungen unserer Wissenschaftler*innen aus den vergangenen Jahren.
Aktuelle Publikationen (Politik- und Verwaltungswissenschaft)
(2023): Growth produces coordination trade-offs in Trichoplax adhaerens, an animal lacking a central nervous system Proceedings of the National Academy of Sciences of the United States of America (PNAS) ; 120 (2023), 11. - e2206163120. - National Academy of Sciences. - ISSN 0027-8424. - eISSN 1091-6490
Growth produces coordination trade-offs in Trichoplax adhaerens, an animal lacking a central nervous system
How collectives remain coordinated as they grow in size is a fundamental challenge affecting systems ranging from biofilms to governments. This challenge is particularly apparent in multicellular organisms, where coordination among a vast number of cells is vital for coherent animal behavior. However, the earliest multicellular organisms were decentralized, with indeterminate sizes and morphologies, as exemplified by Trichoplax adhaerens , arguably the earliest-diverged and simplest motile animal. We investigated coordination among cells in T. adhaerens by observing the degree of collective order in locomotion across animals of differing sizes and found that larger individuals exhibit increasingly disordered locomotion. We reproduced this effect of size on order through a simulation model of active elastic cellular sheets and demonstrate that this relationship is best recapitulated across all body sizes when the simulation parameters are tuned to a critical point in the parameter space. We quantify the trade-off between increasing size and coordination in a multicellular animal with a decentralized anatomy that shows evidence of criticality and hypothesize as to the implications of this on the evolution hierarchical structures such as nervous systems in larger organisms.
(2023): Lower diurnal HPA-axis activity in male hypertensive and coronary heart disease patients predicts future CHD risk Frontiers in Endocrinology ; 14 (2023). - 1080938. - Frontiers. - eISSN 1664-2392
(2023): Optimized proximity thermometer for ultrasensitive detection : Role of an ohmic electromagnetic environment
Optimized proximity thermometer for ultrasensitive detection : Role of an ohmic electromagnetic environment
We propose a mesoscopic thermometer for ultrasensitive detection based on the proximity effect in superconductor (S)-normal-metal (N) heterostructures. The device is based on the zero-bias anomaly (ZBA) due to the inelastic Cooper pair tunneling in an SNIS junction (I stands for an insulator) coupled to an ohmic electromagnetic (EM) environment. The theoretical model is done in the framework of the quasiclassical Usadel Green's formalism and the dynamical Coulomb blockade. The usage of an ohmic EM environment makes the thermometer highly sensitive and not saturating down to very low temperatures, T≲5 mK. Moreover, defined in this way, the thermometer is stable against small but non-vanishing voltage amplitudes typically used for measuring the zero-bias differential conductance in experiments. Finally, we proposed a simplified view, based on an analytic treatment, which is in very good agreement with numerical results and can serve as a tool for the development, calibration, and optimization of such devices in future experiments in quantum calorimetry.
(2023): LEXpander : Applying colexification networks to automated lexicon expansion Behavior Research Methods ; 2023. - Springer. - ISSN 1554-351X. - eISSN 1554-3528
Recent approaches to text analysis from social media and other corpora rely on word lists to detect topics, measure meaning, or to select relevant documents. These lists are often generated by applying computational lexicon expansion methods to small, manually curated sets of seed words. Despite the wide use of this approach, we still lack an exhaustive comparative analysis of the performance of lexicon expansion methods and how they can be improved with additional linguistic data. In this work, we present LEXpander, a method for lexicon expansion that leverages novel data on colexification, i.e., semantic networks connecting words with multiple meanings according to shared senses. We evaluate LEXpander in a benchmark including widely used methods for lexicon expansion based on word embedding models and synonym networks. We find that LEXpander outperforms existing approaches in terms of both precision and the trade-off between precision and recall of generated word lists in a variety of tests. Our benchmark includes several linguistic categories, as words relating to the financial area or to the concept of friendship, and sentiment variables in English and German. We also show that the expanded word lists constitute a high-performing text analysis method in application cases to various English corpora. This way, LEXpander poses a systematic automated solution to expand short lists of words into exhaustive and accurate word lists that can closely approximate word lists generated by experts in psychology and linguistics.
(2023): European tragedy as requiem, ruin, revenant in Magnet Theatre’s 'Antigone (not quite/quiet)' and Thomas Köck’s 'antigone. a requiem' South African Theatre Journal ; 2023. - Taylor & Francis. - ISSN 1013-7548. - eISSN 2163-7660
European tragedy as requiem, ruin, revenant in Magnet Theatre’s 'Antigone (not quite/quiet)' and Thomas Köck’s 'antigone. a requiem'
Offering a comparative case study of two different postcolonial responses to Sophocles’s tragedy Antigone from European and African perspectives, this article brings together Magnet Theatre’s Cape Town production of Antigone (not quite/quiet) with Thomas Köck’s play antigone. a requiem that premiered almost simultaneously in September 2019 in Hannover, Germany. Both re-examine Sophocles’s tragedy to come to terms with their respective colonial histories and postcolonial challenges: while Magnet Theatre engages with the ancient material to reflect on the difficulties of fully overcoming the legacies of colonialism in post-apartheid South Africa, Köck explores the afterlives of ‘thebaneuropean’ colonialism as manifested in current European migration policies. Comparing the adaptation principle of Magnet Theatre’s ‘ruinous’, fragmenting approach to the literary and theatrical archive of European colonialism to Köck’s postdramatic recomposition of Antigone as a requiem for migrant deaths and for European tragedy itself, the article discusses the productions in their respective contexts of political protest movements. Drawing on cultural theory of ungrievability, domopolitics, and postcolonial shame, it explores the central functions of the chorus – indecisive Europeans on the verge of anagnorisis in Köck’s play, the post-apartheid South African generation caught between rage and disillusionment in Magnet Theatre’s production – and as well as the prominence of Ismene as a problematic survivor figure in both adaptations.
(2023): 1,4-Divinylphenylene-bridged diruthenium complexes with 2-hydroxypyridine- and 2- or 8-hydroxyquinoline-olate ligands Zeitschrift für Naturforschung B ; 78 (2023), 3-4. - S. 75-93. - De Gruyter. - ISSN 0932-0776. - eISSN 1865-7117
Ruggeri's relaxed Navier-Stokes-Fourier system has three retardation times as parameters, one for shear viscosity, the second for the bulk viscosity, and the third for heat conduction.
The present paper establishes decay estimates that are uniform for these parameters tending to zero.
(2023): Maschine auf Mission Frankfurter Allgemeine Sonntagszeitung ; Nr. 9 vom 5. März 2023. - S. 56
(2023): A Facile and Rational Method to Tailor the Symmetry of Au@Ag Nanoparticles Advanced Materials ; 2023. - Wiley. - ISSN 0935-9648. - eISSN 1521-4095
Precisely controlling the morphologies of plasmonic metal nanoparticles (NPs) is of great importance for many applications. Here, a facile seed-mediated growth method is demonstrated that tailors the morphologies of Au@Ag NPs from cubes/cuboids to chiral truncated cuboids/octahedra, well-defined octahedra, and tetrahedra, via simply increasing the concentrations of AgNO3 and cysteine in the halide surfactant systems. Accordingly, the particle symmetries are also tuned. The method is quite robust where seeds with distinct shapes including irregular ones can all lead to uniform Au@Ag NPs. The evolution of these shapes can be illustrated by a recently proposed symmetry-based kinematic theory (SBKT). Furthermore, SBKT shows a strategy to optimize the preparation of chiral/dissymmetric NPs, and the experimental results confirm such a dissymmetric synthesis strategy. Cuboids and octahedra with corners differently truncated are identified as two different chiral forms. The chirality of the NPs is additionally probed by electrochemistry, where the chiral NPs show enantioselectivity in the oxidation of d- and l-glucose. Altogether, the results gain fundamental insights into tailoring the plasmonic NP morphologies, and also suggest strategies to obtain chiral NPs.
(2023): Population dynamics hide phenotypic changes driven by subtle chemical exposures : implications for risk assessments Ecotoxicology ; 32 (2023). - S. 281-289. - Springer. - ISSN 0963-9292. - eISSN 1573-3017
Population dynamics hide phenotypic changes driven by subtle chemical exposures : implications for risk assessments
Ecological risk assessment of chemicals focuses on the response of different taxa in isolation not taking ecological and evolutionary interplay in communities into account. Its consideration would, however, allow for an improved assessment by testing for implications within and across trophic levels and changes in the phenotypic and genotypic diversity within populations. We present a simple experimental system that can be used to evaluate the ecological and evolutionary responses to chemical exposure at microbial community levels. We exposed a microbial model system of the ciliate Tetrahymena thermophila (predator) and the bacterium Pseudomonas fluorescens (prey) to iron released from Magnetic Particles (MP-Fe dis ), which are Phosphorus (P) adsorbents used in lake restoration. Our results show that while the responses of predator single population size differed across concentrations of MP-Fe dis and the responses of prey from communities differed also across concentration of MP-Fe dis , the community responses (species ratio) were similar for the different MP-Fe dis concentrations. Looking further at an evolutionary change in the bacterial preys’ defence, we found that MP-Fe dis drove different patterns and dynamics of defence evolution. Overall, our study shows how similar community dynamics mask changes at evolutionary levels that would be overlooked in the design of current risk assessment protocols where evolutionary approaches are not considered.
(2023): Fairness of inequality and support for redistribution : directly comparing citizens and legislators West European Politics ; 2023. - Routledge. - ISSN 0140-2382. - eISSN 1743-9655
Economic inequality constitutes a defining challenge of our time and it remains puzzling why rising levels of inequality have not led to more redistribution. In this article a novel individual-level perspective is taken, with a focus on how much legislators and citizens agree on questions of redistribution and inequality, and what causes these mismatches. The study compares legislators’ views to a representative citizen sample in Switzerland. The results show considerable disagreement between the groups with legislators being more sceptical towards redistribution and seeing inequality as fairer outcome. The mismatch is only partially explained by legislators’ higher social status. Ideology plays a fundamental role as more polarisation according to ideological lines is found among elites and their attitudes are also more rooted in their ideology. In sum, the findings point to some underexplored angles of the puzzle of why not more redistribution has been observed and thus offer a valuable addition to the existing literature.
(2023): Vocabulary Teaching in Refugee Children within the Context of the Greek Formal Education Languages ; 8 (2023), 1. - 7. - MDPI. - eISSN 2226-471X
The aim of the present study is to investigate vocabulary teaching in children with refugee backgrounds. The effectiveness of three vocabulary interventions—flashcards, pantomime, and use of contextual cues—is examined within the context of formal primary education in Greece. The improvement of the children’s vocabulary is also assessed in association with factors related to the students’ background as well as factors related to the words taught. Thirty-three pupils from the second to the sixth primary school grade attended the teaching interventions. Their first languages are Arabic, Farsi, and Kurdish. According to the results, flashcards and pantomime significantly improve children’s second language vocabulary skills, while this finding does not apply to the intervention involving contextual cues. Age is found to play a role only in the latter intervention, while the effectiveness of no intervention was influenced by word category.
(2023): Excess labile carbon promotes diazotroph abundance in heat-stressed octocorals Royal Society Open Science ; 10 (2023), 3. - 221268. - The Royal Society. - eISSN 2054-5703
Nitrogen limitation is the foundation of stable coral-algal symbioses. Diazotrophs, prokaryotes capable of fixing N 2 into ammonia, support the productivity of corals in oligotrophic waters, but could contribute to the destabilization of holobiont functioning when overstimulated. Recent studies on reef-building corals have shown that labile dissolved organic carbon (DOC) enrichment or heat stress increases diazotroph abundance and activity, thereby increasing nitrogen availability and destabilizing the coral-algal symbiosis. However, the (a)biotic drivers of diazotrophs in octocorals are still poorly understood. We investigated diazotroph abundance (via relative quantification of nifH gene copy numbers) in two symbiotic octocorals, the more mixotrophic soft coral Xenia umbellata and the more autotrophic gorgonian Pinnigorgia flava, under (i) labile DOC enrichment for 21 days, followed by (ii) combined labile DOC enrichment and heat stress for 24 days. Without heat stress, relative diazotroph abundances in X. umbellata and P. flava were unaffected by DOC enrichment. During heat stress, DOC enrichment (20 and 40 mg glucose l −1 ) increased the relative abundances of diazotrophs by sixfold in X. umbellata and fourfold in P. flava , compared with their counterparts without excess DOC. Our data suggest that labile DOC enrichment and concomitant heat stress could disrupt the nitrogen limitation in octocorals by stimulating diazotroph proliferation. Ultimately, the disruption of nitrogen cycling may further compromise octocoral fitness by destabilizing symbiotic nutrient cycling. Therefore, improving local wastewater facilities to reduce labile DOC input into vulnerable coastal ecosystems may help octocorals cope with ocean warming.
(2023): Are we hunting bats to extinction? : Worldwide patterns of hunting risk in bats are driven by species ecology and regional economics Biological Conservation ; 279 (2023). - 109944. - Elsevier. - ISSN 0006-3207. - eISSN 1873-2917
Are we hunting bats to extinction? : Worldwide patterns of hunting risk in bats are driven by species ecology and regional economics
Bats are routinely neglected in conservation, often regarded as uncharismatic and constantly maligned despite their provision of economic and ecosystem services. Yet many species are threatened, and while the loss of roosting and foraging habitat has been explored, the impacts of hunting on species survival are less well understood. Here, we analysed the hunting risk of 1320 bat species (of 1400 known) from around the world and explored the association between ecological traits and socioeconomic variables. Globally, at least 19 % of species are threatened by hunting. Large-bodied bats with narrow distributions are at increased risk of hunting, particularly in tropical regions. Multiple threats, such as habitat loss and modification, are likely to exacerbate the pressures experienced by hunted species. Furthermore, accessibility to bat habitats and low-income drive bat hunting in developing countries. With the global economic recession and the need for economic recovery following the pandemic, hunters may rely more on wildlife for subsistence and pose a threat to both biodiversity and public health. Achieving the balance between economics and conserving biodiversity is challenging due to socioeconomic factors, and the complex interplay of different forms of threat. Therefore, interventions to reduce bat hunting activities should include greater investment to facilitate sustainable livelihood development in the rural economy, and elevating public knowledge about bat ecosystem services, and their potential role in the transmission of zoonotic diseases.
(2023): Thermally induced all-optical ferromagnetic resonance in thin YIG films New Journal of Physics ; 25 (2023), 3. - 033016. - IOP Publishing. - eISSN 1367-2630
All-optical ferromagnetic resonance (AO-FMR) is a powerful tool for the local detection of micromagnetic parameters, such as magnetic anisotropy, Gilbert damping or spin stiffness. In this work we demonstrate that the AO-FMR method can be used in thin films of yttrium iron garnet (YIG) if a metallic capping layer (Au, Pt) is deposited on top of the film. Magnetization precession is triggered by heating of the metallic layer with femtosecond laser pulses. The heat pulse modifies the magneto-crystalline anisotropy of the YIG film and shifts the quasi-equilibrium orientation of the magnetization, which results in precessional magnetization dynamics. The laser-induced magnetization precession corresponds to a uniform (Kittel) magnon mode, with the precession frequency determined by the magnetic anisotropy of the material as well as the external magnetic field, and the damping time set by a Gilbert damping parameter. The AO-FMR method thus enables measuring local magnetic properties, with a resolution given by the laser spot size.
(2023): Specifications of standards in systems and synthetic biology: status and developments in 2022 and the COMBINE meeting 2022 Journal of Integrative Bioinformatics ; 20 (2023), 1. - 20230004. - Walter de Gruyter GmbH. - eISSN 1613-4516
Specifications of standards in systems and synthetic biology: status and developments in 2022 and the COMBINE meeting 2022
This special issue of the Journal of Integrative Bioinformatics contains updated specifications of COMBINE standards in systems and synthetic biology. The 2022 special issue presents three updates to the standards: CellML 2.0.1, SBML Level 3 Package: Spatial Processes, Version 1, Release 1, and Synthetic Biology Open Language (SBOL) Version 3.1.0. This document can also be used to identify the latest specifications for all COMBINE standards. In addition, this editorial provides a brief overview of the COMBINE 2022 meeting in Berlin.
(2023): Stimulus classification with electrical potential and impedance of living plants : comparing discriminant analysis and deep-learning methods Bioinspiration & Biomimetics ; 18 (2023), 2. - 025003. - IOP Publishing. - ISSN 1748-3182. - eISSN 1748-3190
Stimulus classification with electrical potential and impedance of living plants : comparing discriminant analysis and deep-learning methods
The physiology of living organisms, such as living plants, is complex and particularly difficult to understand on a macroscopic, organism-holistic level. Among the many options for studying plant physiology, electrical potential and tissue impedance are arguably simple measurement techniques that can be used to gather plant-level information. Despite the many possible uses, our research is exclusively driven by the idea of phytosensing, that is, interpreting living plants’ signals to gather information about surrounding environmental conditions. As ready-to-use plant-level physiological models are not available, we consider the plant as a blackbox and apply statistics and machine learning to automatically interpret measured signals. In simple plant experiments, we expose Zamioculcas zamiifolia and Solanum lycopersicum (tomato) to four different stimuli: wind, heat, red light and blue light. We measure electrical potential and tissue impedance signals. Given these signals, we evaluate a large variety of methods from statistical discriminant analysis and from deep learning, for the classification problem of determining the stimulus to which the plant was exposed. We identify a set of methods that successfully classify stimuli with good accuracy, without a clear winner. The statistical approach is competitive, partially depending on data availability for the machine learning approach. Our extensive results show the feasibility of the blackbox approach and can be used in future research to select appropriate classifier techniques for a given use case. In our own future research, we will exploit these methods to derive a phytosensing approach to monitoring air pollution in urban areas.
(2023): Sozialisation und die Reflexivität von Kultur in der Einwanderungsgesellschaft : Eine videoethnografische Untersuchung des Alltags in postmigrantischen Familien Sozialisation und gesellschaftlicher Zusammenhalt : Aufwachsen in Krisen und Konflikten / Ertugrul, Baris; Bauer, Ullrich (Hrsg.). - Frankfurt am Main : Campus, 2023. - S. 267-300. - ISBN 978-3-593-51734-6
(2023): Apraxie neuroreha ; 15 (2023), 01. - S. 29-35. - Georg Thieme Verlag KG. - ISSN 1611-6496. - eISSN 1611-7654
Das schnelle Erkennen der facettenreichen und durch Störung der motorisch-kognitiven Fähigkeiten gekennzeichnete Gliedmaßenapraxie gestaltet sich häufig schwierig. Oft ist sie durch andere Beeinträchtigungen wie Aphasie, Gedächtnisprobleme oder Hemiplegie verdeckt. Der Artikel gibt Hinweise zur Diagnostik und zu therapeutischen Ansätzen.
(2023): Immune escape of colorectal tumors via local LRH-1/Cyp11b1-mediated synthesis of immunosuppressive glucocorticoids Molecular Oncology ; 2023. - Wiley. - ISSN 1574-7891. - eISSN 1878-0261
Immune escape of colorectal tumors via local LRH-1/Cyp11b1-mediated synthesis of immunosuppressive glucocorticoids
Control of tumor development and growth by the immune system critically defines patient fate and survival. What regulates the escape of colorectal tumors from destruction by the immune system is currently unclear. Here, we investigated the role of intestinal synthesis of glucocorticoids in the tumor development during inflammation-induced mouse model of colorectal cancer. We demonstrate that the local synthesis of immunoregulatory glucocorticoids has dual roles in the regulation of intestinal inflammation and tumor development. In the inflammation phase LRH-1/Nr5A2-regulated and Cyp11b1-mediated intestinal glucocorticoid synthesis prevents tumor development and growth. In established tumors, however, tumor-autonomous Cyp11b1-mediated glucocorticoid synthesis suppresses anti-tumor immune responses and promotes immune escape. Transplantation of glucocorticoid synthesis-proficient colorectal tumor organoids into immunocompetent recipient mice resulted in rapid tumor growth, whereas transplantation of Cyp11b1-deleted and glucocorticoid synthesis-deficient tumor organoids was characterized by reduced tumor growth and increased immune cell infiltration. In human colorectal tumors, high expression of steroidogenic enzymes correlated with the expression of other immune checkpoints and suppressive cytokines, and negatively correlated with overall patients’ survival. Thus, LRH-1-regulated tumor-specific glucocorticoid synthesis contributes to tumor immune escape and represents a novel potential therapeutic target.