Dissertationen/Habilitationen
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Item type: Item , Epithelial Factors Affecting Smooth Muscle Contraction of the Mouse Epididymis(2025) Haas, Dirk StefanUrinary tract infections (UTIs) are some of the most common human bacterial infections, ascending up to the kidneys in severe cases. The epididymis, beyond its known functions in sperm maturation, storage, and transport, may also act through its epithelium as a sensory organ capable of detecting pathogens and initiating defensive response, i.e. contraction of its smooth muscles. This study investigates the role of epithelial taste receptor signaling, particularly the Trpm5 ion channel, in mediating smooth muscle contraction in the mouse epididymis. Using immunohistochemistry, a subpopulation of keratin5-positive basal cells with slender processes extending into the lumen was identified. Co-expression with GNAT3, representing the gustatory signaling cascade, and Dclk1, a marker for tuft cells, indicates the presence of the gustatory signaling cascade and the chemosensory nature of these cells, suggesting these cells may detect luminal stimuli, often linked to danger or infection. Time-lapse imaging experiments revealed that application of the bitter compound denatonium benzoate induced a statistically significant increase in contraction frequency in wild type mice, but not in Trpm5 knockout (KO) mice. These findings confirm the involvement of Trpm5-mediated signaling in the contractile response and suggest that epithelial chemosensory cells play a critical role in the defense mechanism of the epididymis. This mechanism may represent a key evolutionary adaptation for protecting ascending UTI.Item type: Item , The role of small open reading frames in Shewanella oneidensis phage λSo in host takeover and phage proliferation(2025-08) Thöneböhn, Svenja WiebkeBacteriophages are the most abundant biological entities on Earth. They wield an immense influence on microbial ecosystems in almost all habitats by regulating bacterial population dynamics. Most phages follow one of two well-characterised strategies for host exploitation: the lytic or the lysogenic cycle. In both pathways, host cell lysis represents the terminal event and is therefore central to phage fitness. The temperate phage λSo is one of four known prophages in the genome of Shewanella oneidensis MR-1 and has a genome size of about 51 kbp. During lysogeny, λSo remains integrated into the host chromosome, replicating in concert with the host cell. In this study, the lysis system of λSo was characterised as a pinholin-SAR endolysin-two-component spanin pathway. The λSo holin protein, SSo, contains two transmembrane do-mains and also produces an antagonistic isoform through an alternative translation start, named antiholin. This regulatory mechanism enables precise temporal control over the in-itiation of host lysis. In addition to the pinholin and the SAR endolysin, the lysis system requires a two-component spanin complex, made up of an inner membrane protein (i-Spanin, RzSo) and an outer membrane protein (o-Spanin, Rz1So). The corresponding genes are present in an overlapping reading frame structure, and the encoded proteins likely form a functional dimer of two dimers. This putative dimer enables the fusion of the inner and outer membrane. In addition, this work has shown that further, previously uncharacterised gene products are involved in cell lysis. Like many phages, λSo harbours genes encoding small proteins of unknown function. A gene cluster, so called cluster C, was identified, whose deletion significantly reduced the number of plaque-forming units. Cluster C consists of six genes (lcc1 - lcc6) encoding proteins between 41 and 137 amino acids in length that have no obvious homologies to known protein domains. Bioinformatic analysis suggests that Lcc4 and Lcc6 contain putative transmembrane domains. Functional characterisation revealed that Lcc6 plays a critical role in phage-induced host cell lysis. In lcc6 deletion strains, induction of the lytic cycle of λSo using mitomycin C resulted in the formation of phage particles, which, however, failed to lyse the host cells and are therefore not released. These findings suggest that Lcc6 participates in an early phase of the lysis cascade, likely acting in concert with pinholin-mediated membrane disruption. The ectopic expression of the Lcc4 protein on the other hand resulted in a pronounced elongation of the host cells and delocalisation of the FtsZ rings - a phenotype that is compatible with a disruption of cell division. The modelling of plausible protein interactions confirmed that this phenotype results from a direct interaction of Lcc4 with key components of the bacterial divisome, particularly FtsZ and ZipA. Site-directed mutagenesis identified isoleucine residues at positions 16 and 19 as essential for the interaction with FtsZ, and tryptophan 80 and arginine 84 as critical for binding to ZipA. Taken together, these results suggest that Lcc4 specifically inhibits bacterial cytokinesis following prophage induction in order to maximise the availability of the metabolic resources of the host cell during phage replication. The Lcc proteins, encoded by genes of the cluster C, thus represents a previously undescribed phage-host effector system with profound influence on cellular organisation and the course of lysis.Item type: Item , Cholinerge Regulation der ATP-vermittelten Freisetzung des pro-inflammatorischen Zytokins Interleukin-1β(2024-10-31) Richter, KatrinTrotz intensiver Forschung führen Polytraumata und schwere Operationen auch heute noch zu lebensbedrohlichen systemischen Entzündungen, Sepsis und Multiorganversagen, mit einer nicht akzeptablen hohen Gesamtletalität (Westphal und Kampmeier 2015). Eine bedeutende Rolle in der Pathogenese dieser traumainduzierten Immundysfunktion spielt das hochpotente pro-inflammatorische Zytokin IL-1β, welches von Monozyten, Makrophagen sowie von Epithelzellen synthetisiert wird und unerlässlich für die Immunabwehr gegen Infektionen ist. Die Synthese und Freisetzung von IL-1β muss strikt reguliert werden (Dinarello 2018). Nach Verletzungen wird die Reifung und Ausschüttung von IL-1β durch extrazelluläres ATP, das aus dem Zytoplasma geschädigter Zellen stammt, stimuliert und aktives IL-1β sezerniert. Unter normalen Bedingungen bleiben diese pro-inflammatorischen Reaktionen lokal begrenzt. Bei schweren Traumata und großen chirurgischen Eingriffen kommt es hingegen durch massive Gewebeschädigung zu einer überschießenden Zytokin-Ausschüttung und folglich zur traumainduzierten Immundysfunktion. Bis heute gibt es neben entzündungshemmenden Therapien, welche die Infektanfälligkeit aber maßgeblich erhöhen können, keine geeigneten Behandlungen für die traumainduzierte Immundysfunktion. In dieser kumulativen Habilitationsschrift wurden verschiedene Forschungsprojekte zusammengefasst, die einen neuen anti-inflammatorischen cholinergen Kontrollmechanismus der ATP-vermittelten Freisetzung von IL-1β aus mononukleären Phagozyten identifizieren und charakterisieren (Hecker et al. 2015; Zakrzewicz & Richter et al. 2017; Richter et al. 2016; Backhaus et al. 2017 Richter et al. 2018a). Diese cholinerge Regulation beruht auf der Aktivierung von unkonventionellen nAChRs mit den evolutionär hoch konservierten Untereinheiten α7, α9 und/oder α10 durch klassische Agonisten wie ACh, Cholin und Nikotin. Es konnten aber auch mehrere bisher unbekannte, endogene nAChR-Agonisten identifiziert werden: Phosphatidylcholine sowie deren Metabolite wie PC und PC-haltige Moleküle. Gleichzeitig konnte eine vollkommen neue biologische Funktion des Akute-Phase-Proteins CRP, ein sensitiver Entzündungsmarker und Standardparameter in der klinischen Blutanalyse, aufgeklärt werden: In seiner endogenen, PC-bindenden, pentameren Form inhibiert CRP effizient und über nAChR-vermittelt die monozytäre ATP-induzierte Freisetzung von IL-1β (Richter et al. 2018b). Interessanterweise hängt dieser inhibitorische Effekt nicht nur von dem CRP-gebundenen Liganden ab, vielmehr noch potenziert CRP die cholinerge Wirkung von freiem PC um ein Vielfaches (Richter et al. 2018b). Eine prospektive klinische Studie legt zudem nahe, dass erhöhte CRP-Konzentrationen vor einer traumainduzierten Immundysfunktion schützen (Richter et al. 2018b). Demnach scheint CRP Teil einer negativen Rückkopplungsschleife zu sein, welche die IL-1β-Freisetzung bei systemischer Entzündung limitiert. Als einen potenziellen Gegenspieler des cholinergen Regulationsmechanismus, konnte das Aβ1-42-Peptid identifiziert werden (Richter et al. 2020), welches bisher hauptsächlich im Zusammenhang mit der Alzheimer-Krankheit untersucht wurde. An unkonventionellen, monozytären nAChRs wirkt Aβ1-42 in vitro antagonistisch und ermöglicht so die ATP-induzierte IL-1β-Freisetzung in Anwesenheit von nAChR-Agonisten. Da wir zudem Hinweise erbringen konnten, dass das Aβ1-42-Peptid auch in vivo wirkt (Richter et al. 2020), könnte das Aβ1-42-Peptid somit als endogener, pro-inflammatorischer Regulator präventiv gegen Infektionen und Sepsis sein. Die hier zusammengefassten Arbeiten haben zudem wesentlich zu einem Paradigmenwechsel im wissenschaftlichen Blick auf die nAChRs beigetragen. Während nAChRs kanonisch als ionotrope Rezeptoren eine unerlässliche Rolle für die Reizweiterleitung im neuronalen System spielen, sind es metabotrope Funktionen der unkonventionellen nAChRs in mononukleären Phagozyten, die zur Inhibition des ATP-sensitiven P2X7 Rezeptors führen und somit die IL-1β-Freisetzung inhibieren (Hecker et al. 2015; Zakrzewicz & Richter et al. 2017; Richter et al. 2016; Richter et al. 2023a). Diese Erkenntnisse sind von großer Bedeutung für die Rezeptorforschung und gehen weit über die cholinerge Kontrolle der IL-1β-Freisetzung hinaus. Durch unsere Erkenntnisse rückte auch die α9-nAChR-Untereinheit immer mehr in den Fokus. In weiteren Arbeiten konnten neben synthetischen nAChR-silent agonists auch spezifische α9-Agonisten charakterisiert werden (Richter et al. 2022; Richter et al. 2023b). Dabei zeigten sich neben der anti-inflammatorischen Wirkung auch eine potente analgetischen Wirkung von α9-nAChR-Liganden, die somit eine vielversprechende therapeutische Option zur Behandlung von inflammatorischen Erkrankungen und Schmerz sein könnten. Ein großer Vorteil des hier identifizierten cholinergen Kontrollmechanismus ist, dass gezielt die traumainduzierte (ATP-abhängige) Freisetzung von IL-1β inhibiert, gleichzeitig die IL-1β-abhängige Pathogenabwehr jedoch nicht völlig unterbunden wird. Zudem erwarten wir von den endogenen nAChR-Agonisten wie Phosphatidylcholine und seine Metabolie, sowie von den synthetischen silent agonists, dass sie nicht mit den kanonischen nAChR-Funktionen im Nervensystem interferieren. Somit ist dieser Mechanismus ein vielversprechender Ansatzpunkt für die dringend benötigten präventiven Therapien einer traumainduzierten Immundysfunktion.Item type: Item , Feasibility Studies towards Accessing Generalised Distribution Amplitudes in Exclusive γ-Meson and γγ Production with PANDA at FAIR(2025) Khalid, FaizaUnderstanding the fundamental properties and interactions of the proton remains a central focus in contemporary hadron physics. Its internal structure and the dynamics of hadronic interactions can be explored through exclusive reactions involving antiproton–proton annihilation. This work presents a study of three exclusive channels: $\bar{p}$p → π⁰γ, $\bar{p}$p → π⁰π⁰, and $\bar{p}$p → γγ, with a focus on their potential to probe nucleon structure and reaction dynamics. The studies are performed at four discrete beam momenta of 2.5, 5, 10, and 15 GeV/c. These investigations are carried out in the framework of the PANDA experiment at the upcoming FAIR facility in Darmstadt, which will utilize a high-intensity antiproton beam in the momentum range of 1.5–15 GeV/c. Data samples for both the signal and all relevant background channels were generated and simulated using the PANDARoot framework. This study includes the optimization of the signal-to-background ratio, estimation of count rates, and determination of expected cross sections along with their statistical uncertainties. The results demonstrate that all relevant background channels can be sufficiently suppressed, confirming the feasibility of measuring these reactions at PANDA with sufficient accuracy to significantly advance the understanding of hadron structure in the time-like regime.Item type: Item , Einfluss inflammatorischer Stimuli auf das kardiomyozytäre Differenzierungspotential mesenchymaler Stammzellen(2024) Hellwig, YuliyaThe results of this project show that an inflammatory environment impairs the cardiac differentiation of stem cells. The meta-analyses show that stem cell therapies significantly reduce mortality and improve LVEF moderately, but significantly. However, the effect that was hoped for, namely the regeneration of infarcted tissue, does not materialize. The results of this study show that the inflammatory environment prevailing after a heart attack has a negative effect on the cardiac differentiation of stem cells. Modulation of the inflammatory niche could improve the cardiac differentiation rate of stem cells and thus achieve regeneration of the damaged myocardium. Further studies could focus on identifying factors that interfere with cardiac differentiation more precisely. Another starting point for research could be the modulation of inflammation, which would lead to better differentiation of the injected stem cells.Item type: Item , Interphase Growth Kinetics and the Partial Electronic Conductivity of Constituents in Sulfide Solid-State Batteries(2025-06) Alt, Christoph DanielLarge-scale electrification of transportation and advancements in energy storage are key to achieving net-zero emissions. Solid-state batteries present a promising energy storage solution, expected to enable the use of high-capacity electrode materials such as lithium metal and lithium alloys, while also improving safety. However, effectively integrating high-capacity electrode materials remains a key challenge in unlocking the potential of solid-state batteries. The high reactivity of lithium metal poses both safety and operational challenges, leading to dendrite formation and loss of active redox species (i.e., long-term capacity fading). Since most inorganic solid electrolytes undergo reduction upon contact with alkali metal, the corresponding interphase formation and the resulting long-term increase in cell resistance are often underestimated. However, interphase kinetics and the consequent impact on cell performance strongly depend on the composition and properties of the reaction products. Revealing the interphase composition, growth kinetics, and the influence and role of its individual constitu-ents is crucial for developing protective strategies and enhancing material compatibility. Within this doctoral thesis, the intrinsic transport properties and growth kinetics of the interphase and its constituents for lithiated Li6PS5Cl are investigated, emphasizing their impact on long-term cell operation. Following the quantification of the interphase's partial conductivities through bulk-material synthesis, which revealed a significant resistance contribution over the battery's lifespan, conventional physiochemical concepts were revisited. The Wagner diffusion model, predicting diffusion-controlled interphase growth based on experimental data, was analyzed for solid|solid interfaces alongside the Hebb-Wagner method for accurately quantifying low electronic conductivities in lithium-ion conductors. The former addressed the influence of different interface morphologies on evaluating interphase rate constants by impedance measurements, while the latter revealed the partial electronic conductivity of lithium halides (i.e., LiCl, LiBr, and LiI) present in various interphases. Alloy electrodes, owing to their higher electrode potentials relative to lithium metal, are expected to cause reduced degradation of sulfide solid electrolytes. In this context, In/(InLi)x electrodes – prominent for exhibiting a stable potential of 0.62 V vs. Li+/Li – were first investigated to assess how preparation influences electrode microstructure and performance. Controlling microstructure is critical to avoid current constriction and ensure consistent operation. Studies on thin indium films deposited on current collectors offered insights into interphase growth kinetics at alloying interlayers – an essential challenge for reservoir-free cells – and highlighted the gradual degradation of Li6PS5Cl at the electrode potential of In/(InLi)x. Overall, this doctoral thesis advances the fundamental understanding of intrinsic degradation processes at the electrode|electrolyte interface. In particular, this work provides a new perspective on how multiphase interphases form and evolve over time, depending on their partial ionic and electronic transport properties. It delivers essential insights on previously inaccessible kinetic parameters that now enable more accurate computational simulations, improve the prediction by analytical models, and guide the rational design of more stable materials and interfaces to minimize capacity losses in (reservoir-free) solid-state batteries.Item type: Item , Essays on Climate Change, Migration and Labor Mobility(2025) Braun, MariusThis dissertation consists of five papers that explore different themes from the fields of environmental and migration economics. The first two papers are concerned with the impacts of climate change and natural disasters on international as well as regional migration patterns. The following two articles investigate the distributional and regional effects of CO2 pricing in Germany. The final paper analyzes differences in labor mobility across immigrant generations in the context of the European Debt Crisis.Item type: Item , Visualization of parasite–host interactions using atmospheric-pressure MALDI mass spectrometry imaging(2025) Wiedemann, Katja RebeccaEndoparasites completely rely on the host organism to survive, once they entered their host. Though, hosts do not capitulate but try to protect themselves against potential damage induced by the parasite. Taking these two effects together, leads to measurable changes in the composition and lateral distribution of metabolites in host tissue (upon infection). In order to find novel drug targets, further knowledge on such changes is crucial. Using mass spectrometry imaging to investigate host-parasite interactions in vivo in an untargeted fashion whilst maintaining the lateral information of metabolites is a powerful approach. Therefore, two distinct models were studied: Schistosoma-mansoni-egg-containing liver samples of hamsters infected with the blood flukes, and bovine skin tissue, showing cysts formed by the apicomplexan parasite Besnoitia besnoiti.
For both parasite-host systems, characteristic infection markers were found with significant changes in signal intensities.
Additionally, by benefiting from the fact that lateral information is kept during mass spectrometry imaging analysis, the lateral distribution of infection markers was revealed. For some of them, co-localized biological structures were observed in optical images of the analyzed tissues.
During schistosomiasis, Schistosoma mansoni eggs are deposited in the hamster liver, leading to granuloma formation around the eggs. The high lateral resolution of the AP-SMALDI5 AF ion source enabled the unambiguous visualization of both, eggs (100 µm to 200 µm in diameter) and local abundance changes of lipids in granulomatous tissue compared to healthy hepatic tissue. Guided by results obtained with liquid chromatography-tandem mass spectrometry, we observed a substructure in formed granulomas by applying mass spectrometry imaging. For example, ether-phosphatidyl-ethanolamines were mainly found in the outer part of the granulomas. In total, 372 substances were found to be significantly changed due to infection.
In the skin of Besnoitia besnoiti-infected cattle, MS images showed both, enrichment and depletion of several lipid species inside parasite-formed cysts. Due to the high lateral resolution at 2 µm pixel size, some of them were even found to be characteristic for the thin cyst walls. Applying multiple MSI methodologies, cysts were further characterized by on-tissue tandem mass spectrometry as well as 3-dimensional imaging. Overall, 552 ions were found to be altered due to infection.
Overall, gained insights into parasite-host interactions can now be used as starting points for further metabolism studies and also serve as potential drug targets.Item type: Item , Dynamic critical behavior of hot and dense QCD matter from the real-time functional renormalization group(2025) Roth, JohannesIn this work, we study dynamic critical behavior of hot and dense QCD matter near second-order phase transitions. We consider the chiral phase transition for two flavors of massless quarks, as well as the conjectured critical point at physical quark masses and finite baryon chemical potential. These are plausibly in the same dynamic universality classes as a four-component Heisenberg antiferromagnet and the liquid-gas critical point of a pure fluid, respectively, whose critical dynamics are described by Models G and H in the Halperin-Hohenberg classification.
Our central tool in this work is a real-time generalization of the functional renormalization group (FRG) based on the Schwinger-Keldysh contour. Starting with Model G, we develop a novel formulation of the real-time FRG which preserves all relevant symmetries of dynamical systems with reversible mode couplings. We show that associated Ward identities imply exact statements about the FRG flow, including the non-renormalization of the mode-coupling constant, and the independence of the static free energy on the dynamics. We show that the formalism reproduces the non-trivial value z=d/2 for the dynamic critical exponent in d spatial dimensions, and we compute a novel scaling function which describes the universal temperature and momentum dependence of the iso-vector and iso-axial-vector charge diffusion coefficient in the chiral limit.
As a next step, we adapt this novel FRG technique to Model H. We derive analytical expressions for dynamic critical exponents that describe the universal power-law divergence of the heat conductivity and the shear viscosity near the QCD critical point. As a central result, we find that the critical exponent of the shear viscosity as a function of d exhibits a maximum in the range 2 < d < 4 and approaches zero for d=2 spatial dimensions. We verify the robustness of this result by considering improved truncations of the static free energy. In parallel, we emphasize the structural similarities and differences with Model G by comparing the fixed-point structures of both models and discuss the presence/absence of weak and strong dynamic scaling relations.
While the leading universal scaling behavior can be described by Models G and H, non-universal corrections require a real-time description of the microscopic dynamics. In this regard, we consider a real-time formulation of the quark-meson model as a particular low-energy effective theory for QCD. As a first application, we study the influence of bosonic dissipation on the phase diagram and the excitation spectrum. We find that dissipation has a non-vanishing but quantitatively small effect on equilibrium observables. The influence on the excitation spectrum, on the other hand, can be drastic, as (over-)damping potentially turns weakly-damped quasiparticles into purely relaxational excitations.Item type: Item , Insect mediated bioconversion in the circular bioeconomy: evaluation of quality, safety and environmental impact(2024) Rossi, GiacomoIndustrially farmed insects are receiving increasing attention within the modern bioeconomy. Due to a diverse range of microorganisms living in their gut, insects are able to grow on biological waste and by-products, recover nutrients and produce new high-quality materials to be exploited within the agriculture, food, feed, medical and industrial sectors. Their high adaptability to different conditions, along with their limited production of greenhouse gasses, low use of resources, high feed conversion and valuable nutritional profile, has also suggested them as potential food and feed sources for the future. However, despite such interesting properties, legislative limitations, often led by fragmented and contradictory knowledge or lack of data, appear to be a serious limitation for their affirmation in the circular bioeconomy. This thesis focuses on the evaluation of quality, safety and environmental impact of edible insects produced by applying circular economy concepts. Chapter 1 defines the overall background knowledge motivating the performed experiments. It offers an overview of the research gaps that form the basis for the experimental work and describes the overall structure of the thesis. A general introduction covering several aspects concerning the use of insects in the circular bioeconomy, with a specific focus on insects as waste management tool and as future food and feed is summarised in Chapter 2. Chapter 3 represents the core of the thesis. Six experiments, carried out with the aim of answering the research questions defined in Chapter 1 and addressing the identified research gaps are presented and discussed. Specifically, section 3.1 focuses on the development of a new, non-destructive optical system for the rapid monitoring of quality changes of edible insect products. Fluorescence spectra of dry insect powders, produced by milling insects of five different species belonging to the Orthoptera order, were recorded. The 3D data were organised into an Excitation Emission Matrix (EEM) and analysed through machine learning tools. Five independent fluorescence peaks, each resulting from a different class of chemical compounds, were identified. The obtained results were therefore further applied to detect the oxidation status of insect paste subjected to high hydrostatic pressure (HHP) processing (section 3.2). Two experiments were conducted by applying HHP to insect paste at 600 MPa for 5 min. In the first experiment (experiment 2.1), three modified atmosphere packaging (MAP) and normal air packaging were applied after HHP treatment and microbial load as well as lipid and protein oxidation status were monitored during 28 days of refrigerated storage. Results suggested that the combination of HHP with oxygen-free MAP allowed shelf-life extension up to 10 days when refrigeration was applied. However, HHP treatment was found to be responsible for oxidation initialisation. Therefore, the second experiment (experiment 2.2) aimed to validate such observation and test whether addition of commercial antioxidant mixtures before applying HHP could delay the oxidation process. Results showed that although antioxidants exhibited their activity differently during the storage (with the synthetic antioxidant being more active in the initial stage of the storage while the natural antioxidant being more active in a later stage), HHP alone was not responsible for any significant oxidation. Considering the most interesting aspect of edible insects regarding waste conversion, section 3.3 investigates the possibility of using black soldier fly larvae (BSFL) as a tool for managing waste from aquaculture production (ASW). Two experiments, the first using fresh (daily-collected) ASW and the second applying anaerobically digested (bulk-accumulated) ASW, were therefore carried out. The first experiment (experiment 3.1) demonstrated that BSFL can conveniently convert ASW; however, the high water content of the initial material required the inclusion of other ingredients in the diet. Mixtures consisting of 75% ASW and 25% of chicken feed were found to be optimal for supporting larval growth and waste conversion. However, the amount of nutrients assimilated by the larvae was extremely low, indicating a significant loss of nutrients. High nutrients retention and consequently a low environmental impact was observed in substrate 100ASW, which was characterised by low dry matter content, resulting in feed limitation for the BSFL. These results were further confirmed in the second experiment (experiment 3.2), which showed that conditions leading to high larval growth performances were negatively correlated with the reduction of environmental impact. Furthermore, experiment 3.2 also displayed low growth ability of BSFL on bulk accumulated ASW, indicating that fresh ASW should be preferred for insect-mediated aquaculture waste conversion processes. However, although these two experiments showed low nutrient retention by BSFL reared under optimal conditions, the actual amounts of nutrients lost by the larvae in form of gas were not quantified. Therefore, in order to accurately quantify the gas emissions from edible insects during the rearing process, a new open dynamic gas emission chamber was designed and validated for monitoring the greenhouse gas (GHG) emissions from edible insects on a small scale (section 3.4). Validation experiment was carried out by rearing BSFL on moistened chicken feed. Obtained results showed that BSFL produced neither CH4 nor N2O, while CO2 production strictly depended on insect growth and metabolic activity. Accordingly, CO2 emission curves closely resembled the larval growth curves, indicating that an accurate estimation of GHG emission from insects should consider the overall life cycle of the insect, from eggs to harvesting stage, including the neonate stage. Based on the obtained results, an overall conclusion highlighting the main findings and addressing the research questions defined at the beginning of the thesis is presented in the final chapter (Chapter 4). Relevance of the overall thesis within the circular bioeconomy framework and the future steps needed to promote a full transition to the circular bioeconomy, are also illustrated in this chapter.Item type: Item , Analyse der Wirkung von microRNAs auf die Monozyten-Makrophagen Differenzierung am Beispiel von THP-1 Zellen(2025) Aslantas, ÖzdenDie Erforschung von microRNAs verspricht in Zukunft bahnbrechende Ergebnisse in der Diagnose und Therapie von Erkrankungen zu liefern. Sie beteiligen sich auch an der Entstehung der Atherosklerose, welche den Grundpfeiler für kardiovaskuläre Erkrankungen bildet. Ein wesentlicher Schritt bei der Entstehung der Atherosklerose ist die Differenzierung von Monozyten zu Makrophagen. Die hier vorgelegte Studie untersucht die Expression ausgewählter microRNAs während der Monozyten- Makrophagen-Differenzierung. Die Untersuchung erfolgte an THP-1 Zellen, einer monozytären Zelllinie. Unter Stimulation der Zellen mit Phorbol-12-myristat-13-acetat (5ng /ml PMA) differenzierten diese zu Makrophagen, was schon mikroskopisch an einem veränderten Phänotyp mit Pseudopodien und polymorpher Erscheinungsform zu erkennen war. Auch die CD14- mRNA Expression, als Marker für die Makrophagendifferenzierung, zeigte eine signifikante Erhöhung nach 72-stündiger PMA-Stimulation. Unter dieser PMA- Stimulation wurden Expressionen verschiedener microRNAs analysiert. let-7f und miR- 92a wurden unter PMA-Gabe runterreguliert. Eine Hochregulation erfuhren miR-1, miR- 22 und miR-143. Die Expression von miR-21, miR-99a und miR-223 blieb unverändert. Die unter PMA-Gabe runterregulierten microRNAs, let-7f und miR-92a, zeigten nach Transfektion mit ihren jeweiligen AgomiRen einen Anstieg der Expression in den behandelten Zellen. AgomiR-let-7f steigerte die CD14-mRNA Expression, wohingegen der Einsatz von AgomiR-92a dazu führte, dass die CD14-mRNA Expression unter PMA reduziert wurde. Unter den AntagomiRen bewirkte lediglich AntagomiR-1 eine signifikante Erniedrigung der miR-1 Expression unter PMA. Unter diesen Bedingungen stieg die CD14-mRNA Expression. Die Makrophagendifferenzierung ist demnach bei niedriger miR-1 Expression verstärkt. Schlussfolgernd kann man sagen, dass von den untersuchten microRNAs let-7f, miR-92a und miR-1 die Differenzierung von Monozyten zu Makrophagen unter PMA-Gabe beeinflussen. Verhindert man den Abfall von miR-92a, so wird die CD14-mRNA Expression und somit die Makrophagendifferenzierung reduziert. Dagegen bewirkt eine Reduktion von let-7f oder miR-1 eine erhöhte CD14-mRNA Expression, was auf eine verstärkte Differenzierung zu Makrophagen hinweist. Somit könnte eine Modulation der miR-1, miR-92a oder let-7f Expression therapeutisch genutzt werden, um atherosklerotische Vorgänge zu reduzieren.Item type: Item , Structural development and functional reconstitution in the olfactory system of the clawed frog Xenopus laevis(2025) Kahl, MelinaThe transition of tetrapods to terrestrial habitats is concomitant with the adaptation of the olfactory system (OS) to the environment. This is reflected at the anatomical and functional levels with the formation of different subsystems, including cell subpopulations that exhibit distinct protein expression at the molecular level. The expression patterns of specific proteins vary between different species, although the olfactory systems show general anatomical similarities. For instance, in fish the calcium-binding protein S100Z is expressed in different cell types in their olfactory epithelium, while in mammals it is associated with cells within the vomeronasal organ (VNO). In the course of my thesis, I analyzed the expression pattern of S100Z in the OS of the anuran Xenopus laevis. Using immunohistochemistry in whole mount and slice preparations I identified a subgroup of S100Z expressing olfactory receptor neurons (ORNs) in the larval main OS and in the middle cavity of adult Xenopus laevis. In larval animals, these ORNs showed a lateral distribution bias in the olfactory epithelium and exclusively projected into the intermediate and lateral glomerular cluster. In conclusion, S100Z expression in the OS of Xenopus laevis is exclusively associated with the main OS and not with the VNO. Maintaining regenerative capacity is essential for the OS because of its exposed position to toxic substances or physical trauma. This capacity is attributed to the presence of two main cell types. Firstly, the basal cells of the olfactory epithelium, which are neuronal stem cells and support constant renewal by developing new supporting cells and ORNs. Secondly, the olfactory ensheathing cells (OECs), which enwrap the axons of ORNs until they project into the olfactory bulb (OB) in the forebrain. To date, the existence and role of OECs in the OS of Xenopus laevis have not been investigated in detail. I found vimentin expressing OECs enwrapping ORN axon bundles from the epithelium until the OB in larval Xenopus using immunohistochemistry. The presence of fibroblasts and macrophages in the olfactory nerve (ON) was determined through the utilization of immunohistochemistry and transgenic Xenopus lines. Unilateral ON transection induced a temporary transient and dynamic phosphorylation of the ribosomal protein S6 in these non-neuronal cells. In summary, I identified various cell types within the ON which protein expression is influenced by ON injury. The exact function of phosphorylated ribosomal protein S6 in the OS of Xenopus is still unknown.Item type: Item , Struktur-Funktions-Analyse der äußeren Netzhaut von Patienten mit biallelischen Sequenzvariationen im RPE65 Gen mittels Spectral Domain Optischer Kohärenztomographie(2025) Tanrikulu, ÖzgünBiallelische Sequenzvariationen im RPE65 Gen stellen sich phänotypisch variabel als Lebersche Congenitale Amaurosis (LCA), Early Onset Severe Retinal Degeneration (EOSRD) oder Retinitis Pigmentosa (RP) dar und sind mit frühen funktionellen und strukturellen Veränderungen der Netzhaut assoziiert. Diese manifestieren sich unter anderem mit einem reduzierten Visus und einer Schichtdickenreduktion der äußeren Retina. Das Ziel dieser Studie war eine Feinanalyse und Charakterisierung der Veränderungen in der zentralen Retina vom Retinalen Pigmentepithel (RPE) bis zur Externen Limitierenden Membran (ELM) mittels A-Scan Analyse des Spectral Domain- Optischen Kohärenztomographen (SD-OCT) bei Patienten mit genetisch gesicherten biallelischen Sequenzvariationen im RPE65 Gen (RPE65-Inherited Retinal Dystrophies/RPE65-IRDs) im Vergleich zu einer gesunden Kontrollprobandengruppe sowie eine Struktur-Funktions-Analyse des fovealen Zentrums und des Visus. Ferner wurden die interokulär funktionelle Symmetrie des BCVA und die strukturelle Symmetrie der Schichten im fovealen Zentrum der Patientenaugen untersucht. SD-OCT-B-Scans von 21 Augen von 11 Patienten mit RPE65-IRDs wurden anhand von Qualitätskriterien und einer zumindest partiellen Abgrenzbarkeit der Ellipsoid Zone (EZ) ausgewählt und analysiert. Die SD-OCT-A-Scans wurden im fovealen Zentrum und an definierten Messpunkten in Abständen von 250-500 μm bis zu 3000 μm nach nasal und temporal zum fovealen Zentrum untersucht. Die im Hinblick auf das Lebensalter angeglichene gesunde Kontrollprobandengruppe bestand aus 10 Probanden. Die Abstände der Peaks der hyperreflektiven Banden der äußeren retinalen Schichten wurden vom RPE zur ELM, vom RPE zur EZ und von der EZ zur ELM jeweils mit einer hausintern entwickelten MATLAB Software in vertikaler Achse bestimmt. Der jeweilige bestkorrigierte Visus (BCVA) zum Untersuchungszeitpunkt wurde der Patientenakte entnommen. Bei einem jungen Patientenkollektiv [Altersspannweite 4-23 Jahre, Altersmedian 7 Jahre] mit mindestens partiell erhaltenen Schichten der äußeren Retina bestätigte diese Studie vorangegangene strukturelle Erkenntnisse, wie die eines frühen Verlusts der EZ- und ELM-Schicht und eine Reduktion der äußeren Retina. Auch die vorbekannte hohe funktionelle interokuläre Symmetrie der Abnahme des BCVA konnte für die Gesamtgruppe der Patienten bestätigt werden. Bei Betrachtung der Ellipsoid Zone Width (EZW) als Landmarke der retinalen Degeneration wurde als neue Erkenntnis hinzugewonnen, dass Patientenaugen mit regelrechter EZW im B-Scan eine ebenfalls hohe interokuläre Symmetrie des BCVA gezeigt haben, wohingegen bei Schädigung der EZW im B-Scan eine Abnahme der interokulären BCVA Symmetrie nachweisbar war. Wie vorangegangene Studien war bei hoher Streuung der Werte kein linearer oder anderer Zusammenhang zwischen der Reduktion der äußeren Retina im fovealen Zentrum und des BCVA abgrenzbar. Bei Unterteilung der Zapfen im fovealen Zentrum in die Subschichten RPE-EZ als Schicht der Außensegmente und der äußeren Innensegmente sowie der EZ-ELM als Schicht der inneren Innensegmente ließ sich als weiterführende neue Subanalyse jeweils kein linearer Zusammenhang dieser Schichten und des BCVA feststellen. Während als weitere neue Erkenntnis bei regelrechter Abgrenzbarkeit der hyperreflektiven Schichten der äußeren Retina und einem BCVA ≤0.1 logMAR die RPE-ELM Schicht und die RPE-EZ Schicht im fovealen Zentrum eine interokuläre Symmetrie zeigten, ließ die EZ-ELM Schicht keine interokuläre Symmetrie erkennen. Letztere könnte auf eine frühe, ungleichförmig interokuläre Degeneration der Innensegmente der M- und L-Zapfen im fovealen Zentrum schließen lassen. Unter Nutzung der Kennzonen der Early Treatment Diabetic Retinopathy Study (ETDRS) konnte als weitere neue Erkenntnis bei Patientenaugen mit einem BCVA ≤0.1 logMAR für die RPE-ELM und RPE-EZ Schichten ein erhaltenes physiologisch glockenförmiges Muster von der temporären und nasalen Makulakennzone zum fovealen Zentrum beobachtet werden, während dieses physiologische Muster von der peripheren zur makulären Kennzone bereits bei diesen Patientenaugen aufgehoben war. Da bei der gleichen Patientenaugengruppe dieses physiologische Muster für die EZ-ELM Schicht in sämtlichen ETDRS Kennzonen nicht nachweisbar war, könnte dies einen Indikator einer frühen Degeneration der Photorezeptorinnensegmente darstellen. Bei den Patientenaugengruppen mit einem BCVA >0.1 logMAR konnten sowohl für die RPE- ELM Schicht wie auch für die Subschichten RPE-EZ und EZ-ELM eine Aufhebung des glockenförmigen Verdickungsmusters abgegrenzt werden, sodass eine ungerichtete und homogene Reduktion, respektive Degeneration, in der zentralen Retina nachweisbar war. Die Gruppe mit einem BCVA >0.1 - 0.49 logMAR und ohne Sehschwäche zeigte dabei ein identisches Degenerationsmuster wie die Gruppe mit einem BCVA >0.49 logMAR und Sehschwäche nach WHO-Kriterien. Mittels SD-OCT-A-Scan Analyse der äußeren Schichten in der zentralen Retina kann durch Peak-zu-Peak-Messung der hyperreflektiven Schichten eine unkomplizierte Degenerationsevaluation bei Patienten mit biallelischer Sequenzvariation im RPE65 Gen im Verlauf bzw. zur Evaluation möglicher gentherapeutischer Effekte in den postinterventionellen Kontrollen sowie im postinterventionellen Langzeitkontrollverlauf vorgenommen werden. Bei bereits nachgewiesener Zapfendegeneration bei jungen Patienten mit sehr gutem BCVA regen diese Ergebnisse ferner eine Diskussion zur frühen Indikationsstellung der subretinalen Gentherapie an.Item type: Item , Die Bedeutung humaner Papillomviren in der Kopf-Hals-Onkologie(2024) Wagner, SteffenTrotz des allgemeinen sinkenden Konsums von Tabak bleibt die Inzidenz von Kopf-Hals-Karzinomen (KHK) in Deutschland und anderen Ländern weitgehend konstant. Dies geht auf eine signifikante Zunahme HPV-assoziierter Karzinome zurück, was inzwischen als Risikofaktor bei Plattenepithelkarzinomen des Oropharynx (OPSCC) anerkannt ist. Unsere, sowie weitere Arbeiten der letzten Jahre zeigen, dass HPV-assoziierte OPSCC eine eigenständige Tumorentität sind und sich grundlegend von Noxen-assoziierten KHK unterscheiden. Virale Onkoproteine wie E6 und E7 sind neben der charakteristischen Überexpression des zellulären p16INK4a an einer Reihe molekularer Veränderungen beteiligt, die in HPV-negativen OPSCC durch genetische Veränderungen ausgelöst werden. Hierzu gehören insbesondere immun-escape Mechanismen, wie die Reduktion der HLA Klasse I Expression oder die Induktion hemmender Liganden (z.B. PD-L1) von Immun-Checkpoint Signalwegen. Dennoch sind HPV assoziierte OPSCC durch eine Präsenz von Immunzellen (wie NK-Zellen) charakterisiert. Viele dieser HPV-bedingten Veränderungen können diagnostisch und therapeutisch bedeutsam sein. So kann virale DNA im Blut von Tumorpatienten (liquid biopsy) nachgewiesen und mit dem Verlauf der Erkrankung korreliert werden. Angesichts der Bedeutung von HPV in der Kopf-Hals-Onkologie und des spezifischen Mechanismus der Karzinogenese, mit vergleichsweise homogenen Veränderungen und meist milderen klinischen Verläufen, erscheinen HPV assoziierte OPSCC besonders geeignet für neue immunologische Therapiekonzepte.Item type: Item , Analyse der DNA-Reparaturmechanismen nach therapeutischer Genomeditierung mittels induzierbarer Cas9 Endonuklease in vitro(2025) Türk, Franziska MariaErblich bedingte Netzhauterkrankungen betreffen viele Menschen und sind häufig verantwortlich für den Verlust der Sehkraft. Begründet liegen sie meist in einer Mutation eines relevanten Gens. Es existieren unterschiedliche therapeutische Optionen, die abhängig von dem Wissen um die Ursache und dem Fortschritt der Erkrankung zum Einsatz kommen. Therapeutische Genomeditierung, das damit einhergehende Einbringen eines DSBs sowie die nachfolgenden zelleigenen Reparaturmechanismen stellen eine wichtige Rolle im Bereich der Gentherapie dar. Ziel dieser Arbeit war es, das BRET-Reportersystem in Verbindung mit einer induzierbaren Cas-Variante zu testen und mehr Informationen über das neuronenspezifische Verhalten nach einem induzierten DSB zu generieren. Nachdem die Funktionalität des bereits in der Arbeitsgruppe entwickelten BRET-Systems mit den entsprechenden gRNA/Cas9-Komplexen bestätigt wurde, folgte die Herstellung eines induzierbaren Cas9-Systems passend zu den Targetsequenzen der BRET-Reporter, welche in HEK293-T-Zellen transfiziert und auf ihre Funktionalität hin überprüft wurden. Im letzten Schritt der Arbeit wurde versucht, das Cas9-System mit gRNA und BRET-Reporten mittels Cotransfektion in die iNGNs zu integrieren. In Zukunft kann die Kombination der gRNA/iCas mit anderen Reportersystemen zu weiteren Informationen über das zellspezifische Reparaturverhalten nach einem DSB führen. Hier sollte jedoch zunächst die Erhöhung der Transfektionseffizienz der iNGNs im Fokus stehen und durch Änderung der Transfektionsmethode, der DNA-Bereitstellung und/oder des Promotors gesteigert werden. Kurzfristiges Ziel ist es, die iNGNs als intermediäres System mit gRNA/iCas-Systemen zu etablieren, um neuronenspezifische Informationen im Bereich der DNA-Reparaturforschung in Bezug auf erblich bedingte Netzhauterkrankungen generieren zu können. Langfristig steht die Ermöglichung einer direkten Therapie von erblich bedingten Erkrankungen mittels Genome Editing im Zentrum des Bestrebens. Zukünftig könnten CRISPR/(i)Cas und iPSCs somit einen wesentlichen Beitrag zu einer patientenspezifischen, regenerativen Medizin leisten.Item type: Item , Mitigating Interfacial Degradation in Sulfide-Based Solid-State Batteries using Polymer Coatings and Surface-Modified Solid Electrolytes(2025-04-11) Shi, Bing-XuanThe growing market for electric vehicles is driving demand for high-energy-density batteries. Conven-tional liquid electrolyte batteries (LEBs) are nearing their energy-density limits, while solid electrolyte batteries (SEBs) using high-nickel cathode active materials (CAMs), solid electrolytes (SEs), and the lithium metal anode promise much higher energy densities. Sulfide-based SEs, such as Li6PS5Cl, exhibit particularly high ionic conductivity, making them promising candidates for industrial applications. How-ever, the interfacial degradation between sulfide-based SEs and electrodes limits their electrochemical performance. This dissertation explores innovative strategies to enhance the interfacial stability at both the cathode-electrolyte interphase (CEI) and the solid electrolyte interphase (SEI) in SEBs, focusing on polyelectrolyte coatings and modified sulfide-based SEs. Polyelectrolytes are selected as electrode coating materials in this dissertation for their flexibility, ease of processing, and lower cost than inorganic coatings. Moreover, they provide intrinsic ionic conductivity compared to neutral polymers, which is essential in SEBs but less of a concern in LEBs. While polymers as coatings in LEBs are well-studied, there is limited insight into their use in SEBs. This gap motivates this dissertation, demonstrating how polyelectrolytes enhance interfacial stability and performance in SEBs. The journey begins with exploring a polycation coating on LiNi0.83Co0.11Mn0.06O2 using the spray-drying method, revealing their potential and limitations. The polycation coating uniformly covers CAM particles to enhance cycling stability, but improved lithium-ion conductivity is needed to prevent capacity loss. Building on these findings, a subsequent study introduces a polyanion/amide polymer blend as a coating on LiNi0.9Co0.05Mn0.05O2, with the polyanion providing a lithium source to mitigate capacity loss and the amide polymer serving as a coating inducer. However, the polyanion/amide polymer coating demonstrates stiffness that needs more flexibility. As a result, a polyelectrolyte complex (PEC) coating is developed for LiNiO2 (LNO) cathode and a Si anode. This PEC employs a polycation to induce coating formation alongside a polyanion with a flowing nature that enhances both lithium-ion conductivity and flexibility. On the other hand, compared with the use of polyelectrolyte coatings, the modification of sulfide-based SEs via solvent treatment provides another approach to reducing the interfacial degradation of SEBs. This method improves the interfacial stability between the LNO cathode and the sulfide-based SE while preventing dendrite formation from the lithium metal anode. Additionally, modified sulfide-based SEs reveal a mechanism for enhancing cathodic performance different from the polyelectrolyte coating layer. This suggests that the combination of polyelectrolyte coatings with modifications to sulfide-based SEs could further bolster interfacial stability. This dissertation comprises four studies, including polyelectrolyte-coated electrodes and modified sul-fide-based SEs in SEBs. Each study employs a distinct approach to mitigate interfacial degradation and shows promising potential for industrial application. Collectively, these investigations provide a compre-hensive understanding of the strategies to improve interfacial stability while providing future strategies that can be further developed and studied.Item type: Item , Illuminating the Regulatory Dynamics of Plant Growth: A Study on Cell Cycle Genes and Motif Enrichment in Arabidopsis thaliana(2024) Wang, XuesongPlant growth and development rely on the proliferation and expansion of root tip cells, which involves a network of genes participating in the regulation of the cell cycle, namely the mitotic cell cycle and endocycle. Since plants have their sessile nature, they cannot actively avoid adverse factors imposed by the environment, compelling them to develop a suite of adaptive mechanisms to enhance their adaptability and ensure survival. Some of these adaptive mechanisms influence the regulation of the cell cycle, although the underlying mechanistic connections remain elusive. Including the role of transcription factors in regulating the expression of cell cycle genes and their influencing factors, as well as the regulation of the transition between the mitotic cycle and endocycle, remain current research challenges. Research on plant cell cycle genes reached its peak in the early 21st century when combining cell cycle synchronization in cell cultures with DNA microarray and other technologies. At that time cycle-related genes have been assigned to different cell cycle phases. However, since then, the cell cycle gene networks have hardly been studied or annotated in more detail. Moreover, the ramifications of cell cycle synchronization on the cell cycle dynamics are not fully characterized and quantified. To this end, this work aimed to map and analyze cell cycle gene networks, leveraging more advanced technologies and methodologies, such as single-cell sequencing, to undertake a comprehensive exploration of the cell cycle networks. As for transcriptional regulation mechanisms of cell cycle genes, the focus has primarily been on the issue of transcription factor binding under single motif conditions. This work will focus on the binding characteristics of motif pairs and their role in transcriptional regulation. This work integrated root single-cell and bulk sequencing data of *Arabidopsis thaliana* to calculate correlations, delineating developmental zones at the single-cell level. Cycling cells in these zones were identified using known cell cycle genes and clustering methods. Differential expression analyses on cells in different cycle phases expanded the cell cycle-related gene set. The Paired Motif Enrichment Tool (PMET) identifies promoter motif pairs. Building on the existing PMET foundation, this work extends its application to uncover genetic mechanisms regulating the mitotic cycle and endocycle. Using PMET, diverse promoter motif pairs linked to cell cycle-related and stress-induced genes were identified, elucidating gene regulatory patterns involving synergistic transcription factors. Many motif pairs are specific to genes in certain cycle phases and stress conditions, offering new insights into the regulatory mechanisms of cell cycle and stress-induced gene networks.Item type: Item , Critical analysis of socio-natural dynamics driven by the agricultural commodity boom: the case of Hass avocado in northern Caldas, Colombia(2025) Suarez, AndresThis explanatory study investigates the expansion of Hass avocado plantations (HAP) and their transformative impact on the socio-natural dynamics in Salamina, Caldas, Colombia. The central research question—Why are Hass avocado plantations expanding and transforming the socio-natural dynamics in the Global South?—is addressed through a systematic approach grounded in interdisciplinary frameworks and methods. To address this overarching question, a robust theoretical framework was first developed to analyze the socio-natural interactions underlying these transformations. The study then employed four sub-questions to explore the issue systematically. The first sub-question examined the phenomenon from a Global South perspective, followed by two sub-questions focusing on the specifics of the Salamina case. The final sub-question recontextualized the findings within the broader global transformations of food systems, offering insights into the dynamics of these changes as part of a larger learning process. This interdisciplinary research is underpinned by Critical Realism, integrating theoretical and conceptual approaches from political ecology, critical resource geography, and critical political economy. A multilevel design was utilized to address the four sub-questions, employing tailored sub-designs for each. The study’s overarching objective was explanatory: not only to elucidate the socio-economic and environmental implications of HAP expansion but also to analyze the socio-historical, economic, and political structures enabling this phenomenon. Methodologically, a mixed-methods approach was employed through a sequential design, balancing qualitative and quantitative data collected and analyzed simultaneously before integration during interpretation. A single cross-sectional explanatory case study further deepened the analysis. Findings reveal a complex landscape of socio-economic and environmental dynamics in Colombia’s HAP sector. While the plantations have driven economic growth and employment in Salamina and Caldas, they have also introduced significant environmental and social challenges. Colombia faces a critical juncture where economic development must align with environmental sustainability and social responsibility. Policymakers, environmental agencies, and the agricultural community must act decisively to achieve this balance, leveraging the economic potential of Hass avocados while safeguarding ecological systems and cultural heritage. The development and enforcement of sustainable public policies will be essential to navigating this multifaceted challenge.Item type: Item , Stoffeigenschaften und Umweltverhalten von Ivermectin und anderen Antiparasitika im One Health-Kontext: Interdisziplinäre Herausforderungen für den Bodenschutz(2025) Heinrich, Andre PatrickDie kumulative Dissertation untersucht die Stoffeigenschaften und das Umweltverhalten des Veterinär-Antiparasitikums Ivermectin und weiterer verwandter Wirkstoffe. Ziel ist es, die Umweltrisiken dieser Substanzen aus einer One Health Perspektive zu betrachten. Diese strebt die ganzheitliche Betrachtung der Zusammenhänge zwischen menschlicher Gesundheit, Tiergesundheit und Umweltschutz an. Die Wirkstoffe gehören zur Gruppe der makrozyklischen Laktone, die in Human- und Veterinärmedizin sowie im Pflanzenschutz zur Kontrolle von Schadorganismen verwendet werden. Zunehmend wird auch ein Einsatz in der Vektorkontrolle diskutiert. Der breite Einsatz der Wirkstoffe wirft daher Fragen nach der Vereinbarkeit von Gesundheitszielen und Umweltschutz im Sinne von One Health auf.Item type: Item , Planen - Unterstützen - Durchführen: Fortbildungen in Volkshochschul-Verbandsstrukturen(2025) Nistal, Lydia JohannaDie Verbänden der Volkshochschulen und ihren stadtstaatlichen Zusammenschlüsse sind wichtige Akteure in der Erwachsenen- und Weiterbildung. Sie führen die politische Interessenvertretung ihrer Mitglieder aus, erbringen Dienstleistungen und sind an Forschung und Zeitschriftenwesen in der Erwachsenen- und Weiterbildung beteiligt. Als Forschungsgegenstand sind sie dagegen erst sporadisch erschlossen. Anhand recherchierter Forschungsdesiderate erforscht die Dissertation in einem qualitativen Vorgehen verbandliche Funktionen in Volkschochschul-Verbandsstrukturen. Dabei wird ein besonderer Fokus auf Fortbildungen gelegt, die für die Mitglieder und ihr Personal entwickelt, angeboten und durchgeführt werden. Hierbei zeigen sich mehrere Varianten der Zusammenarbeit zwischen den Verbänden, ihren Mitgliedern und weiteren Akteuren aus dem Organisationalen Feld in verschiedenen Konstellationen.