X-linked centronuclear myopathy (XLCNM), also known as myotubular myopathy, is a rare and severe skeletal muscle disorder that manifests with congenital hypotonia and leads to early childhood mortality due to its currently limited therapeutic options. XLCNM is caused by loss-of-function mutations in the gene encoding the lipid phosphatase myotubularin (MTM1), which dephosphorylates the phosphoinositide phosphatidylinositol 3-phosphate [PI(3)P] at endosomal membranes. Among XLCNM pathomechanisms is impaired muscle cell adhesion via integrins, the transmembrane components of focal adhesions (FAs). Integrin subunit β1 (β1-integrin) plays key roles in the formation and maintenance of specialized skeletal muscle adhesions essential to muscle function. Importantly, MTM1-mediated PI(3)P turnover plays a role in the exocytosis of integrins from endosomes to the plasma membrane, yet the impact of MTM1on cell adhesions has not been described in detail. A functional association between MTM1 and phosphatidylinositol 3-kinase C2β (PI3KC2β), a lipid kinase that synthesizes PI(3)P and phosphatidylinositol 3,4-bisphosphate [PI(3,4)P2], was uncovered in mammals when skeletal muscle-specific ablation of PI3KC2β rescued the disease phenotype of XLCNM mouse models. Previous studies have proposed a direct rebalancing of PI(3)P levels by PI3KC2β as the mechanism underlying the rescue of XLCNM. However, the precise mechanistic interplay between MTM1 and PI3KC2β, and its relevance in skeletal muscle physiological and pathological conditions remains elusive. Thus, in this project we aimed to mechanistically characterize this functional interaction in a cell-based context relevant to XLCNM. By pursuing this objective, we intended to gain insights into the molecular pathogenesis of XLCNM and the role of PI3KC2β in this context, serving as a basis for the development of XLCNM therapeutic strategies. For this purpose, the murine myoblast cell line C2C12 was used to generate knockout (KO) cell lines lacking MTM1, PI3KC2β, or both enzymes. In this system, we described that loss of MTM1 led to cell adhesion defects evidenced by decreased cell spreading, number of FAs and surface activated β1-integrin, which functionally resulted in enhanced migration and impaired myoblast differentiation. Cell adhesion defects and correlated functional phenotypes were completely rescued by co-depletion of PI3KC2β. Contrary to the prevailing opinion, we showed that the accumulation of the MTM1 substrate PI(3)P observed in Mtm1KO myoblasts was not normalized upon co-depletion. Instead, we showed that blockage of endocytosis ameliorated adhesion defects in Mtm1KO myoblasts. Data from HeLa cells, included in this dissertation for completeness purposes, showed that PI3KC2β knockdown (KD) leads to impaired active β1 integrin internalization, a phenotype that we mechanistically explained by a role of PI3KC2β in clathrin-mediated endocytosis (CME) of active β1-integrins. Hence, we propose that MTM1 and PI3KC2β play antagonistic roles in the control of active β1-integrin adhesions by respectively mediating recycling to the plasma membrane and internalization via CME. Treatment of MTM1-depleted cells with a newly developed PI3KC2β inhibitor rescued the reported cell adhesion phenotypes, thus establishing proof-of-principle evidence for a PI3KC2β-targeted XLCNM therapy. Altogether, our findings provide insights into cell adhesion defects key to XLCNM pathogenesis in a newly established in vitro model system. Moreover, we uncover a novel function of PI3KC2β in the regulation of integrin adhesions, setting a mechanistic background for its rescue of the XLCNM disease phenotype, an essential step towards the development of therapies targeting PI3KC2β.

In the presented work, Internet of Things (IoT) technologies, like sensors and their applications, have been investigated from a socio-technical perspective focusing on civic purposes of the technologies’ use. The aim of the work is to gain a better understanding of civic IoT and its transformative potential for society. Therefore, the overarching research question is: What are the societal implications of the technological object civic IoT? Three application areas identified as highly relevant have been studied: community-based environmental monitoring, sustained engagement of civic tech initiatives, and the “Journalism of Things.” In the first study, the civic IoT initiative Luftdaten.info dedicated to the community-based monitoring of particulate matter in the air was examined. The initiative is organized within limits of technical equipment, resources, and academic knowledge. The case study comprises a media content analysis, a web application analysis, and two expert interviews. The data illustrates that the local air pollution topic is a discursive long-term process striving towards a more sustainable city and community. The findings show that the information provided by Luftdaten motivates certain people to become aware and engaged for their local environment, and some to change their behavior. I found that the initiative itself is managed in a sustainable way being inclusive and resource-saving. The media content analysis shows that events around the emergence of the Luftdaten initiative had a certain influence on the local media agenda. Finally, a data map comparison shows how easily misunderstandings in the representation of monitoring data can occur when taking different decisions during the data analysis and visualization of almost identical datasets. In the second study, two long-lasting civic tech initiatives of global scale were investigated to understand what makes them sustain over time. We conducted two mixed-method case studies of the initiative Luftdaten.info from Germany and the initiative Safecast from Japan. We combined social network analysis and qualitative content analysis of Twitter data with insights from expert interviews. Drawing on our findings, we identified a set of key factors that help the studied civic tech initiatives to grow and last. Contributing to Digital Civics in HCI, we argue that the civic tech initiatives’ scaling and sustaining are configured through the entanglement of (1) civic data both captured and owned by the citizens for the citizens, (2) the use of open and accessible technology, and (3) the initiatives’ public narrative, giving them a voice on the environmental issue. In the third study, Journalism of Things (JoT) as a new paradigm in digital journalism was investigated. Three case studies on recent award-winning journalism projects in Germany were conducted with the analytical lenses of boundary work and objects of journalism. The study comprises interviews with journalists, media content analyses, and observations of virtual public events. The findings suggest four typical phases in JoT projects: formation, data work, presentation, and ramification. Blurred boundaries of journalism towards science and activism become apparent when co-creative JoT teams apply scientific methods and technology design while mobilizing communities. Findings further show that things (or objects) of JoT have implications on the configuration for collaborative arrangements and audience relations. By creating and disseminating new local knowledge on matters of common concern, JoT is also contributing to empowering both journalism and citizens. This dissertation is a cumulative work comprising three peer-reviewed scientific publications.

The thesis investigates land tenure dynamics and integrated watershed management. We consider integrated watershed management as a process and act of holistically managing the environment in a given delineated spatial unit, considering both upstream and downstream systems connectivity for social and ecological systems sustainability. Integrated watershed management incorporates several implementation approaches, including integrated water resources management. In the research's first primary objective, we survey the state of integrated watershed management in dynamic land tenure contexts. The second main objective, we examine the relationship between land tenure and integrated watershed management. Proactively, the third objective assesses the relevant land and related resources legislation responsiveness to integrated watershed management and the land tenure dynamic and conceptualises for reforms. Analysing and acquiring data involves qualitative and quantitative methods. The methods include primary data collection through catchment surveys, questionnaires administration, focus group discussions, interviews, and catchment reconnaissance observation. Complimentary data consists of systematic literature reviews, secondary satellite imagery and other Geographical Information System (GIS) data. The methods applied produced both unit and spatial data, with unit data mostly from households as the primary units of analysis and interaction. The data is managed and analysed using GIS tools like ArcMap, QGIS and statistical tools in Ms Excel, SPSS, and R. The study mainly draws case studies from the global south, targeting catchments in the Victoria and Albert basin lakes in Eastern Africa. The main findings and tentative conclusions include (a) integrated watershed management approaches improve water resources governance and resource management amidst land tenure dynamics. The evidence shows a significant difference in the performance of water resources governance markedly better in the catchment with integrated water resources management practices than in the base catchment unaffected by these practices. The finding contributes to the aspirations for promoting integrated watershed management approaches for improved resource governance and the concept that resource management measures depend on governance effectiveness. However, the potential of integrated watershed management encounters limiting social factors such as land tenure. According to the comprehensive literature review (b), land tenure relates to various aspects of integrated watershed management, including driving land use and cover changes. As such, we confirm a relationship between land use and cover changes proportional areas losses ranging between 80% - 95% of woodland and indigenous forests in the case study area in the Lake Victoria basin. This degree of land use and land cover change, the functionality of other change driving factors perceived and the degree of adopting sustainable practices depends on the prevailing land tenure. Achieving integrated watershed management, conversant of the land tenure role, requires an enabling legal and institutional environment. However, the research findings for main objective (c) show the prevailing legislation needs to be more responsive to allow effective integrated watershed management. As such, we suggest reforms and provide model legislation provisional suggestions. We recommend several areas for future research, including assessing the legal feasibility of integrated watershed management and land tenure responsive legislation and the needed land administrative reforms to deliver on ensuring sustainability and sustainable development. The research enhances our understanding of the potential and possibilities of land tenure during integrated watershed management. The study also furnishes scholars, resource managers, policymakers, and program evaluators with more information for decisions.

Campylobacter is a commensal microorganism that generally colonizes the ceca of avian species and is detected in high prevalence in poultry farms. Once colonized with C. jejuni, chickens may remain C. jejuni carriers and excretors until slaughter, which inevitably increases the potential for carcass contamination during processing, in turn allowing transmission of the pathogen to humans. While Campylobacter carriage in broilers is mostly asymptomatic, human infection via contaminated meat causes abdominal pain, fever and acute enteritis and occasionally serious late sequelae like the Guillain-Barré syndrome, reactive arthritis and the Miller-Fisher syndrome. The objective of the present study was to establish a broiler chicken colonization model which targets natural infection and keeps conditions close to commercial poultry production. This model was subsequently used to determine the efficacy of different non-biosecurity based intervention measures to reduce C. jejuni shedding and colonization in broiler chickens. First, we conducted two preliminary studies in which we aimed at determining the lowest inoculation dose necessary to successfully colonize all 20 broiler chickens (of breed Ross 308) after 2 days. For this purpose, we used a dose consisting of 10³ and 104 CFU of a C. jejuni strain. Results revealed that the dose consisting of 104 CFU/500μl fulfilled the desired requirement and was therefore used as an inoculation dose for further experiments. Second, we aimed at examining the effect of different non-biosecurity based intervention measures to reduce C. jejuni colonization in broiler chickens using the established seeder bird model. The study consisted of several experimental groups, each with a specific intervention measure. One group served as a control group while the other group received one of the following treatments: an essential oil (carvacrol), a complex CE culture (Aviguard®), a blend of different organic acids or a combination of two phages. Another group did not receive any treatment but was conducted with an alternative slow-growing breed (Ranger Gold) in combination with a reduced stocking density (25 kg/m2). Each of the measures evaluated showed evident potential to reduce C. jejuni colonization and shedding in broiler chickens during rearing (growing period). However, only one of the measures evaluated, the complex CE culture, proved to be effective in reducing C. jejuni colonization in the cecum. In contrast, colonization of the colon with C. jejuni was significantly reduced by all evaluated measures, except for organic acids. In summary, the complex CE culture can be considered most valuable for the control of Campylobacter in poultry farms because it led to a significant C. jejuni load reduction in the cecum. Even if the other measures did not lead to a reduction in the cecum, they still showed notable potential. Therefore, it cannot be ruled out that further optimizations and new technologies will improve their applicability. Further research, especially large-scale field trials, is needed to investigate the practical effect of distinct control strategies in a commercial poultry production setting.

The combination of high spatial and temporal resolution is still a limiting factor in the field of surface science. Only very recently, a novel experimental approach has been presented that allows versatile access to this regime by combining ultrafast Terahertz (THz) pulses with the extraordinary spatial resolution of scanning tunneling microscopy (STM): The so-called THz-STM. In this device, the THz pulses act as ultrafast transient bias voltage and hence allow to unravel the ultrafast physics of highly localized electronic states via pump-probe experiments. In this thesis, we describe the process of establishing this novel technique in our group. We firstly discuss the new configuration of the designated lab, the design and alignment of our THz-source as well as its characterization using electro-optic sampling. Subsequently we describe the modifications performed on the preexisting STM to facilitate the coupling of THz radiation. The THz-STM was thoroughly tested in different scenarios showcasing its capabilities. We initially present data originating from optical-pump, THz-probe measurements based on photoelectron emission, confirming the successful coupling of ultrashort THz pulses into the STM. Subsequent measurements using field emission resonances show the stability of our system under cryo conditions and using junctions at tunneling distances. Experiments involving Kondo resonances of point defects in MoS2 prove the sensitivity of our THz-STM when used with small nonlinearities and are used to perform exemplary spatially resolved measurements. Finally we present preliminary time-resolved data as part of an outlook.

Microplastic pollution in terrestrial ecosystems has attracted increasing concern regarding possible impacts on soil functionality. Microplastics can affect soil physicochemical properties, such as aggregation, bulk density, water holding capacity, porosity, pH, etc., and also soil microbial activity measured as respiration and enzymatic activities, with ensuing consequences on plant performance. This doctoral work firstly summarized the sources, migration, and distribution of microplastics in the soil, their effects on soil physicochemical properties, soil biota and plant performance based on previous studies. Then this work investigated the microplastic effects on soil physicochemical properties and microbial activity. The effects included both direct and indirect effects of microplastics as a single factor, as well as a study including the combined effects of microplastics with other global change factors. The review study (chapter 2) summarized the microplastic pollution in terrestrial ecosystems including the sources and distribution of microplastics in soil, and the potential migration pathways. Microplastic effects on soil physicochemical properties such as aggregation, water dynamics, pH, and organic matter contents were also included. Finally, this review provided a general understanding of the impacts of microplastics on soil biota including soil fauna and microbes, and their known consequences on plant performance. The first laboratory study (chapter 3) explored the direct impacts of microplastics with different shapes and polymer types on soil pH and microbial activity, and how these effects may change over incubation time. This work revealed the influences of twelve microplastics (four shapes made of three different polymer types) on soil pH and microbial activities. We specifically found that microplastics could affect soil pH, respiration, and enzymatic activities depending on their shape, polymer type, and incubation time. Specifically, soil pH increased with foams and fragments, and overall soil pH reduced initially and increased afterwards over time. Soil respiration increased with foams, and soil respiration declined with time. Enzymatic activities were impacted by microplastic shapes and polymer types, and fluctuated with incubation time. They were negatively correlated with soil pH, and the presence of microplastics weakened this correlation. The second laboratory work (chapter 4) revealed the indirect effects of microplastic-contaminated soil layers on water distribution, soil aggregation, and microbial activities of adjacent soil layers without microplastics. This research indicated that microplastic-contaminating soil layers could affect the water flow and distribution, the proportion of different-sized aggregates, and microbial activities in adjacent soil layers. Specifically, microplastic-contaminating soil layers impacted the vertical water flow along the soil profile surrounding soil layers, with consequences on water contents and distribution in adjacent soil layers. In addition, microplastic-contaminating soil layers changed the proportion of different-sized aggregates in different depths of the adjacent soil layers. These physical changes contributed to the alterations in soil respiration in adjacent soil layers, but not translated to soil enzymatic activities. Interestingly, microplastic fibers showed more pronounced effects than microplastic films on such soil properties. The third laboratory research project (chapter 5) examined the combined effects of microplastics and drought on a soil-plant system. This study evaluated the microplastics direct effect, and its interaction with drought on soil ecosystem functions and multifunctionality. We found that these effects varied with soil water conditions. That is, microplastic fibers (1) inhibited microbial activity (respiration and enzymatic activities) under well-water conditions, while enhanced microbial activities under drought conditions; (2) promoted litter decomposition under well-water conditions, whereas suppressed it under drought conditions; (4) diminished leachate SO42- irrespective of the soil water conditions, decreased leachate NO3- only when microplastics combined with drought, increased leachate PO43- under well-watered conditions; (5) and increased soil aggregation and soil pH regardless of water conditions; (6) microplastic fibers and drought negatively affected not only single ecosystem functions, but also soil ecosystem multifunctionality.

Healthcare costs are systematically rising, and current therapy-focused healthcare systems are not sustainable in the long run. While disease prevention is a viable instrument for reducing costs and suffering, it requires risk modeling to stratify populations, identify high- risk individuals and enable personalized interventions. In current clinical practice, however, systematic risk stratification is limited: on the one hand, for the vast majority of endpoints, no risk models exist. On the other hand, available models focus on predicting a single disease at a time, rendering predictor collection burdensome. At the same time, the den- sity of individual patient data is constantly increasing. Especially complex data modalities, such as -omics measurements or images, may contain systemic information on future health trajectories relevant for multiple endpoints simultaneously. However, to date, this data is inaccessible for risk modeling as no dedicated methods exist to extract clinically relevant information. This study built on recent advances in machine learning to investigate the ap- plicability of four distinct data modalities not yet leveraged for risk modeling in primary prevention. For each data modality, a neural network-based survival model was developed to extract predictive information, scrutinize performance gains over commonly collected covariates, and pinpoint potential clinical utility. Notably, the developed methodology was able to integrate polygenic risk scores for cardiovascular prevention, outperforming existing approaches and identifying benefiting subpopulations. Investigating NMR metabolomics, the developed methodology allowed the prediction of future disease onset for many common diseases at once, indicating potential applicability as a drop-in replacement for commonly collected covariates. Extending the methodology to phenome-wide risk modeling, elec- tronic health records were found to be a general source of predictive information with high systemic relevance for thousands of endpoints. Assessing retinal fundus photographs, the developed methodology identified diseases where retinal information most impacted health trajectories. In summary, the results demonstrate the capability of neural survival models to integrate complex data modalities for multi-disease risk modeling in primary prevention and illustrate the tremendous potential of machine learning models to disrupt medical practice toward data-driven prevention at population scale.

With the advances in high-throughput data acquisition technologies, the amount of heterogeneous and complex data is constantly increasing. The application of intelligent algorithms such as deep neural networks (DNNs), which learn a hierarchy of increasingly complex features from the data, is emerging as an effective paradigm for analyzing complex datasets. In medical research, however, deep learning (DL) may suffer from overfitting due to the high dimensionality of the data. The scarcity of good quality labeled data also intensifies this issue due to the expensive and time-consuming process of providing labels and metadata by the human expert. Besides, despite the simple linear operation of core building blocks of DNNs, the hierarchical combination of these blocks may result in over-parameterization, which makes it challenging to explain their behavior. The black-box nature of these models raises a severe issue on the trustworthiness and reliability of deployed models, especially in high-stakes prediction applications. Therefore, to analyze high-dimensional medical data using DL models in medical settings, we need to address two important questions: 1) How to deal with the curse of dimensionality and limitation of annotated data? 2) How to improve the transparency of deep learning models through interpretability, as it potentially leads to a better understanding of the data and the deployed model?

This thesis addresses these challenges in high-throughput structured data and high-dimensional imaging data modalities. We begin our study on high-throughput structured data with the application of proteomics data analysis. We robustly learn the data representation and extract the medically relevant information using DL techniques. We develop novel data analysis based on what the DL model can learn through interpreting its predictions. This information enables getting insight into the data patterns and discovering discriminating features. We also justify the reliability of the model interpretation through comprehensive quantitative assessments. We show that the proper combination of DL techniques coupled with interpretation strategies that enable an in-depth understanding of model decisions can guide towards a reliable clinical decision support system.

Further, we study DL techniques on high-dimensional imaging data. Unlike structured data where desired features appear with slight deviations, regions of interest on medical images may appear with a large deviation on different data points. Therefore, we built our image analysis on supervised convolutional neural networks (CNN), which can handle large deviations. We investigate different CNN architectures and compare their strength. Finally, we built a robust pipeline on heterogeneous imaging data with the challenging application of human spinal vertebra detection-identification. To deal with the scarcity of data, we show how different techniques, including transfer learning, data augmentation, human-in-the-loop, and synthetic generation of data in medical settings, boost generalization.

In this work the laser-induced ultrafast demagnetization and switching dynamics of magnetically ordered materials were simulated by means of atomistic spin-dynamics simulations. The dynamics of the system were calculated numerically using the stochastic Landau-Lifshitz-Gilbert equation. The obtained results were compared with experimental measurements performed by collaborators from the University of California in Berkeley and at the Fritz-Haber Institute in Berlin, as well as with previously published data. First, various ferrimagnetic GdFeCo alloys were investigated as they are particularly well suited for all-optical switching. During this process, the magnetization is reversed within a few picoseconds of excitation by an ultrashort short laser pulse (approximately 100 fs). Of great technical interest is switching using electrical pulses, which are, however, significantly longer (5-6~ps). Therefore, a wide range of pulse durations were simulated in order to investigate their ability to switch various GdFeCo alloys. It was found that single pulse all-optical switching is possible for pulse durations that span two orders of magnitude. The same underlying physics, based on atomistic spin-dynamics simulations, is able to describe switching within hundreds of femtoseconds as well as tens of picoseconds. Furthermore, element-specific damping was found to be a key parameter for switching using longer pulse durations. The simulation results were compared to experiments, yielding a quantitative agreement when including local Gd-concentration inhomogeneities. Furthermore, the Heusler alloy MnRuGa was modeled. The derived model was able to reproduce various key material properties, such as the Curie temperature, the magnetization curve or the Ru-concentration dependence of the magnetization-compensation temperature. Moreover the model was able to quantitatively reproduce the magnetization dynamics of single pulse toggle switching as measured by Banerjee t al.. It was also demonstrated that, contrary to previous understanding coming from rare-earth transition metal alloys, toggle switching in MnRuGa is possible even when both Mn sublattices demagnetize at very similar rates.

After simulating these two ferrimagnets a general study of switching and magnetization dynamics in ferrimagnetic materials was carried out. A general macroscopic theory for the magnetization dynamics of ferrimagnetic materials driven by femtosecond laser photo excitation was derived. The theory reproduces all stages of the switching process observed in experiments. It was found that during the switching process the magnetization dynamics transitions from a relativistic relaxation path to an exchange-dominated regime due to the strong enhancement of the exchange relaxation.

Next, the special case of an antiferromagnet was considered. The previously developed macroscopic model was applied to antiferromagnets and an equation of motion for their magnetic order were derived. With the help of atomistic spin simulations, a faster, exchange-enhanced magnetization dynamic of antiferromagnets was found and systematically investigated, which was previously only suspected. Notably, the found exchange enhancement depends strongly on the number of neighboring spins of the other sublattice.

In order to better understand switching of magnetic materials, other systems such as the electron and the phonon system are also of great importance. Therefore, spin dynamics simulations in nickel, cobalt and iron were performed using ab initio calculations with the aim of better understanding experimentally measured lattice dynamics. It was found that the energy flow to and from the spin system is of great importance and has a slowing effect on the phonon dynamics. Comparison with experimental data showed that the atomistic spin dynamics simulations provide a consistent quantitative description of all three subsystems, which is an improvement on previously used models such as the three-temperature model.

Patient*innen auf der Intensivstation werden regelhaft mit Sedativa behandelt. Diese Behandlung ist integraler Bestandteil der evidenzbasierten, intensivmedizinischen Therapie und dient der Behandlung von Angst, Stress und Agitation. Neben nicht-pharmakologischen Maßnahmen, kommen Sedativa auch zur symptomorientierten Behandlung von Symptomen eines Delirs zum Einsatz. Studien der letzten Jahre zeigen jedoch, dass gerade die unkritische, tiefe Sedierung mit einem schlechteren Behandlungsergebnis einhergeht und aktuell erheblicher Forschungsbedarf besteht, wie eine sedierende Therapie möglichst risikoarm gestaltet werden kann. In der vorliegenden Arbeit werden drei Aspekte zur Sedierung intensivpflichtiger Patient*innen thematisiert. Zunächst konnte gezeigt werden, dass die Wahl des Benzodiazepins während einer intensivmedizinischen Sedierung mit Sedierungstiefen-Unterschieden und konsekutiven Mortalitätsunterschieden verknüpft ist und selbst die Einmalgabe des Sedativums Etomidat mit potentiell gefährlichen Komplikationen einhergehen kann. Weiter wurde erstmals in der Erwachsenen-Intensivmedizin gezeigt, dass eine tiefere Sedierung die diagnostische Validität der empfohlenen Delirscreeninginstrumente beeinflusst. Dies wurde in einem bizentrischen Ansatz und in einem Kollektiv von Neuro-Intensivpatient*innen untersucht und bestätigt. Interessanterweise sind gerade bei Letzteren die untersuchten, krankheitsspezifischen Störfaktoren weniger relevant als die Sedierung, sodass die diagnostischen Barrieren ähnlich der nicht-neurologischen Intensivmedizin zu bewerten sind. Es spricht also nichts gegen eine prinzipielle Implementierung eines Delirscreenings auch in diesem speziellen Intensivkollektiv. Hierzu konnte bezüglich der aggregierten Evidenz in Form von Leitlinien festgehalten werden, dass zwar aktuell drei qualitativ hochwertige Leitlinien zum Thema Sedierung verfügbar sind, diese aber mutmaßlich wegen Barrieren in der Anwendbarkeit nicht gut in die Praxis implementiert sind. Das Implementierungsdefizit wird in einer untersuchten Ausgangslage vor Leitlinienveröffentlichung im anästhesiologischen, nicht-intensivmedizinischen Schnittstellenbereich unterstrichen: Hier ist ein evidenzbasiertes Delirscreening nur in Einzelfällen implementiert. Folglich sind strukturierte Implementierungskonzepte relevant, um Leitlinienempfehlungen im klinischen Alltag praktikabel umzusetzen zu können. Die in der vorliegenden Arbeit untersuchten Domänen Sedativa, Interaktion von Sedierung und Delir, sowie Implementierung eines Sedierungsmanagements bilden mutmaßlich auch zukünftig wichtige, klinisch und wissenschaftlich relevante Anknüpfungspunkte für die Verbesserung des Managements der Sedierung bei intensivpflichtigen Patient*innen.

Control over the intracellular localisation of RNA is an important aspect of post-transcriptional regulation, especially for highly polarised cells like neurons. The presence of specific transcripts in axons and dendrites, together neurites, is determined by cis-active elements called zipcodes and ultimately allows neurons to locally synthesise required proteins and adapt quickly to cues of the local environment. This capability is important for the correct function of synapse remodelling and memory formation and a disruption of RNA localisation in neurons has been associated with several neurodegenerative diseases.

Using RNA sequencing a vast number of transcripts can be detected in neurites of neuronal model systems. With over 7500 transcripts even the neurite core transcriptome, which I summarised from the published datasets generated in the last decade, contains at least half or a third of the full neuronal transcriptome. Whether all of these transcripts should be considered localised to neurites or if this designation is better determined by differential expression analysis between compartments is still diffcult to answer. For one thing, no strong overlap of transcripts with localisation based on significant enrichment in many individual datasets exists and also my integrated analysis utilising batch correction did only generate a relatively small set of differentially expressed genes, which however tend to have more conserved enrichment. Secondly, several transcripts that are generally considered as classical localised transcripts, like the Actb mRNA, are not relatively enriched in neurites, even if they are strongly expressed there.

Relying on a set of transcripts with consistent neurite enrichment based on datasets from primary murine neurons I designed Nzip, a massively parallel reporter assay (MPRA) aimed at the identification of unknown zipcodes. Based on 16 candidate sequences determined from the first experiment, it was possible to identify 2 new zipcode motifs utilising a secondary library with a mutational analysis approach: the let-7 miRNA seed sequence CUACCUC and an (AU)𝑛 repeat motif. The compartmental quantification of miRNAs and associated protein machinery indicates a stronger activity of let-7 in soma, providing a potential mechanism for its zipcode activity. Additionally, also the (AU)𝑛 motif is also associated with lower read counts in soma and several identified binding proteins have known effects on RNA stability, indicating that it likely also affects RNA localisation through stability regulation. Building on my observations that assignment of RNA localisation state based on either detection or enrichment in neurites both is problematic and that Nzip mainly identified motifs conferring neurite enrichment by RNA stability, I argue that a clear distinction between localised and not-localised tran- scripts may not be an accurate description of the biological system. Instead, zipcodes likely affect the probability of a given transcript to reach neurites and there may also be different mechanisms that affect the tendency for localisation as measured by enrichment or detection. Whether this is a more accurate description of RNA localisation mechanics as well as the exact functions of the zipcodes I identified should be further investigated in future studies.

As a second part of my work I have contributed to studying the human neurodegenerative disease amyotrophic lateral sclerosis (ALS). This affliction is mainly characterised by the degradation of motor neurons usually starting at the synapses between axons and skeletal muscle, the neuromuscular junction (NMJ), and in many cases is known to be caused by mutations in several RNA binding proteins affecting RNA localisation. Among these is the FUS protein, whose mutations often disrupt its exclusive nuclear localisation and thus can lead both to a loss-of-function as well as a toxic gain-of-function trough availability of new RNA targets in the cytoplasm. To study a disease like ALS a cellular model system for human neurons is needed, which replicates the relevant molecular signatures of affected motor neurons, specifically including the axonal containing neurite compartment. I have characterised the transcriptome and proteome of induced motor neurons (iMN) generated by expression of NGN2, ISL1 and LHX3 transcription factors. This system showed expected expression of marker genes throughout motor neuron differentiation as well as proper specification of neurite compartment and similarity with signatures of electrophysiological maturity. Using the iMN model system I performed investigative analysis for the effect of ALS patient derived FUS mutations on the proteome and transcriptome, specifically including effects pronounced in the neurite compartment. With this I identified many differentially expressed genes already associated with ALS or FUS mutations, which, however, span a very wide field of functional associations and to my understanding are more likely linked to a disruption of normal FUS activity. However, I also observed a more consistent and rarely reported pattern of down-regulation of genes building the extracellular matrix around the NMJ, which was specifically notable in the neurites of cells with cytoplasmic localised P525L FUS. Additionally, I found a very similar pattern of down-regulation in neurites for genes passing the secretory pathway, known target transcripts of FUS, as well as those with a G-quadruplex motif, which has been identified as a potential binding site for both FUS and other ALS associated RBPs. This highlights a potential toxic gain-of-function for FUS as well as a particular pathway which may be important in the axonal degeneration in ALS. Validation of this observation including any potential significance of an overlap between the affected gene groups I identified should be the focus of further work.

Unlike cardiac or skeletal muscle cells, vascular smooth muscle cells (VSMCs) retain a remarkable degree of plasticity. On environmental cues they can dedifferentiate from a quiescent contractile state towards phenotypes of increased proliferation and migration as well as secretory capacity and inflammation. This ability to transition between different phenotypes is a prerequisite for physiological vascular remodeling processes, but also plays a key role in the pathogenesis of virtually all vascular diseases. These vascular diseases, above all atherosclerosis resulting in myocardial infarction or stroke, are still the leading cause of death worldwide. Based on the respective metabolic requirements of proliferating versus quiescent cells it was hypothesised that VSMCs undergo metabolic changes during dedifferentiation. Therefore, the aim of this study was to investigate the metabolic adaptions VSMCs exhibit during phenotypic transition and identify possible regulators thereof. Utilising two in vitro models and one in vivo model for VSMC dedifferentiation, this study showed that dedifferentiated VSMCs shift their energy generation from mitochondrial respiration towards elevated glycolysis and lactate production, reminiscent of the Warburg effect observed in cancer cells. Dedifferentiated VSMCs also displayed reduced expression of genes involved in mitochondrial respiration, lower mitochondrial abundance and altered mitochondrial shape, indicating a strong association between mitochondrial homeostasis and VSMC plasticity. The second objective of this study was to investigate whether intervention in VSMC metabolism would affect VSMC plasticity and vascular remodeling. Two known regulators of metabolism, Sirt6 and Sirt7, were chosen for their regulatory function in glucose and mitochondrial metabolism, respectively. The effects of VSMC specific knock-outs of Sirt6 and Sirt7 on VSMC dedifferentiation and proliferation were assessed in vitro and in vivo. Both sirtuins were expected to display atheroprotective functions. This could be confirmed for Sirt7 as the VSMC-specific knock-out of Sirt7 resulted in elevated neointima formation in a carotid artery ligation mouse model and increased plaque sizes in an ApoE-/- atherosclerosis mouse model. VSMC-specific knock-out of Sirt6 did not impact both these parameters. Contrary to expectations, the effects of the Sirt7 knock-out did not seem to be mediated by regulation of mitochondrial homeostasis. The atheroprotective role shown in this study, nevertheless renders Sirt7 an interesting target for the treatment of vascular diseases.

Over the first years of their life, children attain a multitude of social-emotional milestones and develop competencies in the emotional and social domain. Those include the expression and understanding of basic emotions, acquiring emotion regulation strategies, development of early forms of prosocial behavior, or building and maintaining early relationships with their peers. Caregivers support a child’s social-emotional development via a variety of socialization practices and processes: They are, for example, models for constructive emotion regulation, employ emotion-related parenting practices, and create a positive emotional climate. Of particular relevance for a child’s early social-emotional development is the attachment relationship, the “emotional bond” between a child and their caregiver. Delays or deficits in the development of social-emotional competence may indicate signs of early maladjustment or translate into subsequent problems or disorders. Psychosocial risk factors predict the occurrence and perpetuation of early social-emotional problems, while promotive and protective factors are associated with positive developmental outcomes. Developmentally appropriate preventive intervention programs strive to contain age-specific risk factors, promote risk-reducing conditions, and support children and adolescents to attain vital developmental tasks and transitions. Due to the strong increase in the rate of childcare for children under the age of three in Germany, the early childhood education and care (ECEC) center and ECEC teachers as context and agents of preventive interventions come to focus. Teachers’ relationships with the children are of great importance for their social-emotional development, and these relationships may qualify as attachment relationships. Accordingly, several preventive intervention programs have focused on the child-teacher relationship and have repeatedly shown to be effective in targeting teacher variables such as knowledge, attitudes, or interaction quality and children variables such as social-emotional or communicative skills. Nonetheless, there is a lack of evaluated, quality-assured programs in Germany that can be comprehensively implemented. The aims of this dissertation are, thus, 1.) to investigate the how family risk factors exert their influence on a child’s developmental outcomes in the ECEC context, 2.) how these effects can be addressed by ECEC teachers, and 3.) to describe the development, content, as well as formative and summative evaluation of the prevention program Papilio-U3 (Ortelbach et al., 2022) that addresses teachers in ECEC. The Papilio-U3 program aims at fostering sensitive teacher-child interactions and by this, the social-emotional development and attachment security of the children to their ECEC teachers. The Papilio-U3 program was developed and evaluated in a research project by collaborating teams from Freie Universität Berlin, Friedrich-Alexander-Universität Erlangen-Nürnberg, and Papilio gGmbH, Augsburg. It was evaluated by implementing a multi-centric, randomized intervention and waiting-control group design study that comprised three measurement waves and assessed numerous outcome measures and important covariates on the teacher and child level (e.g., observational, questionnaire, and developmental test data). The dissertation encompasses three manuscripts that draw on the data of the Papilio-U3 pilot evaluation. The aim of the first manuscript was to investigate individual and institutional risk and protective conditions for the development of social-emotional competence and problems children display in the ECEC center. The second manuscript built on these insights and aimed to introduce the developmentally appropriate prevention program Papilio-U3 and to document the initial results from the pilot evaluation study. The aim of the third manuscript was to evaluate the effectiveness of the Papilio-U3 program regarding outcomes at the teacher level. For Manuscript I, we asked 56 ECEC teachers to provide information on the characteristics of the ECEC center, their job-related stress, and self-efficacy beliefs as well as to assess the social-emotional competence and problems of the children from their groups (N = 353). Additionally, the parents provided information on family risk factors (proximal and distal risk). To account for the nested data structure, we conducted multilevel analyses and estimated a series of linear mixed models separately for children’s social-emotional competence and problems as outcomes. More proximal (but not distal) risk factors predicted higher social-emotional problem scores of the children and we found a trend for a cross-level interaction involving teachers’ self-efficacy: The association of risk and problem score decreased with increasing levels of teachers’ self-efficacy. A child’s age and gender, as well as teachers’ self-efficacy, predicted social-emotional competence: Higher competence scores were associated with females, older children, and higher teacher self-efficacy. Manuscript II comprises the overview of the development and evaluation of the developmentally appropriate prevention program Papilio-U3 according to the intervention mapping approach (IMA, Bartholomew Eldredge et al., 2016): We described the program planning process comprising a needs assessment and description of the intervention context, the derivation of the change model, gave an account of the program design, production, implementation, and an overview of the program evaluation study. For the formative evaluation, the teachers of the intervention group (IG) provided extensive information on training content, methods, and potential challenges during the program implementation. Results indicated that the participating teachers were generally satisfied with the program content and teaching methods and stated that they would recommend it to other teachers. Manuscript III considered teacher attributes (i.e., perceived job-related stress and teachers’ self-efficacy beliefs) as the first outcomes of the summative evaluation of the Papilio-U3 program. These teacher attributes have in past studies been linked to process quality (e.g., teacher-child interactions) and child outcomes. We randomly assigned the participating teachers (N = 125) to an intervention or waiting-control group and asked them to rate their job-related stress and self-efficacy on three occasions (before, during, and after program implementation). Longitudinal analyses of covariance revealed that, post-intervention, teachers of the intervention group reported higher self-efficacy beliefs compared to the waiting-control group (controlling for baseline scores). The groups did not differ significantly on job-related stress. For the concluding discussion of the dissertation, I focus on the relevance of teachers’ self-efficacy beliefs, job-related stress, and the importance to support teachers in ECEC. I then provide an outlook on the further steps of the program evaluation. A detailed discussion of program contents focuses exemplarily on fostering teachers’ emotion talk and the utilization of the video-feedback method. Furthermore, important practical implications of the results of this dissertation are outlined, namely, the widespread implementation of the Papilio-U3 program, the relation to the two subsequent programs for preschoolers and children of the first years in elementary school, Papilio-3to6 and Papilio-6to9 (Lechner et al., 2022; Scheithauer & Peter, 2022), and the benefits of a sequence of prevention programs for children aged 0 to 9.

Hintergrund: Die vorliegende Arbeit beschäftigt sich mit der Bildung und Wirkungsweise von Omega 3 Epoxyeicosanoiden, einer neuen Klasse bioaktiver Lipidmediatoren, die durch Cytochrom P450 Enzyme (CYP) aus langkettigen Omega-3 Fettsäuren gebildet werden.

Hypothesen und Zielstellung: Es wird vermutet, dass die Omega-3 Epoxyeicosanoide die kardioprotektiven und antiarrhythmischen Effekte der im Fischöl enthaltenen Omega-3 Fettsäuren, insbesondere der Eicosapentaensäure (EPA) und Docosahexaensäure (DHA), vermitteln. Bei den infrage kommenden Metaboliten handelt es sich um 17,18 Epoxyeicosatetraensäure (17,18-EEQ) und 19,20-Epoxydocosapentaensäure (19,20-EDP). Dementsprechend sollte in der vorliegenden Arbeit die Hypothese geprüft werden, ob 17,18-EEQ selbst über die gewünschten kardioprotektiven und antiarrhythmischen Eigenschaften verfügt, die sonst EPA zugeschrieben wird. Darüber hinaus sollten erste Untersuchungen zum Verständnis der beteiligten Signalwege durchgeführt werden. Ein weiteres wesentliches Ziel war die Identifizierung von metabolisch stabilen, synthetischen 17,18-EEQ Analoga für eine zukünftige klinische Anwendung.

Methoden: Zur Erreichung dieser Ziele wurde ein in der Literatur bereits beschriebenes Zellmodell zur Analyse der kardioprotektiven und antiarrhythmischen Eigenschaften von Omega-3 Fettsäuren aufgebaut und nach detaillierter Validierung angewendet. Es handelt sich um ein Schlagfrequenz Assay, der mit isolierten, spontan schlagenden neonatalen Rattenkardiomyozyten (NRKM) durchgeführt wird. Der Hauptweg zur Identifizierung der Signaltransduktionskomponenten waren pharmakologische Interventionsstudien.

Ergebnisse: Die Schlagfrequenz der NRKMs wurde durch 17,18-EEQ und deren getesteten synthetischen Analoga innerhalb weniger Minuten reduziert. Dieser negativ chronotrope Effekt stellte einen Surrogatmarker für die kardioprotektiven und antiarrhythmischen Effekte der Epoxyeicosanoide dar. Unter den validierten Bedingungen wurde für 17,18 EEQ ein halbmaximale Wirkungskonzentration (EC50) von 11,96 nM und ein maximaler negativ chronotroper Effekt von -28,93 Schlägen pro Minute (bpm) ermittelt. Im Gegensatz dazu trat der negativ chronotrope Effekt von EPA erst nach einer Inkubation von über 30 min auf und erreichte bei einem EC50 von 2342 nM in etwa die gleiche Schlagfrequenzreduktion. Darüber hinaus konnte gezeigt werden, dass eine pharmakologische Inhibition von CYP-Epoxygenasen durch den Wirkstoff MS-PPOH zum Verlust der Wirkung von EPA, aber nicht von 17,18-EEQ führte. Im Ergebnis der Struktur-Funktions-Analyse von 17,18-EEQ wurde die Compound 4 (C4) identifiziert, die sich gegenüber 17,18-EEQ durch einen verbesserten EC50 (1,41 nM) und einem erhöhten negativ chronotropen Effekt (-36,70 bpm) auszeichnete. Gegenüber 17,18 EEQ enthält C4 nur eine Doppelbindung (11,12-Position), die Epoxygruppe ist durch ein Bioisostere (Oxamid-Gruppe) ersetzt und eine weitere Modifikation (3 Oxa Gruppe) dient zur Verhinderung der β-Oxidation und des Membraneinbaus. Die Beteiligung des PI3K/AKT/eNOS/PKG Signalwegs sowie ATP-abhängiger Kalium-Kanäle (KATP) konnte am Effekt von 17,18-EEQ und C4 mittels pharmakologischer Inhibitionen identifiziert werden. Primäre Zielstruktur ist möglicherweise ein G-Protein gekoppelter Rezeptor (GPCR), da die Behandlung der NRKMs mit Pertussis Toxin sowie der lentivirale Knockdown von Filamin A zum Verlust der Wirksamkeit von 17,18-EEQ und C4 führten. C4 reduzierte im NRKM Assay zudem signifikant die elektrische Erregbarkeit, sowie die Ca2+ Transientenamplitude im Vergleich zum Vehikel.

Schlussfolgerungen: Die Ergebnisse der vorliegenden Arbeit bestätigen die Hypothese, dass Omega-3 Epoxyeicosanoide die eigentlichen Vermittler der kardioprotektiven und antiarrhythmischen Effekte von Omega-3 Fettsäuren sind. Die Wirkung umfasst Veränderungen im Ca2+ Stoffwechsel und der elektrischen Erregbarkeit von Kardiomyozyten. Der Mechanismus beruht wahrscheinlich auf einer GPCR vermittelten Aktivierung des PI3K/AKT/eNOS/PKG Signalweges sowie von KATP Kanälen. Mit C4 konnte ein biologisch hochaktives und metabolisch stabiles 17,18-EEQ Analog identifiziert werden. Tatsächlich erwies sich C4 in weiterführenden Untersuchungen der OMEICOS Therapeutics GmbH auch in anderen präklinischen Modellen als therapeutisch wirksam und steht jetzt für erste klinische Anwendungen zur Verfügung.

One of the major proteins involved in the pathogenesis of inflammatory diseases of the intestine is tumor necrosis factor (TNF), a pro-inflammatory cytokine that can disturb epithelial barrier function by altering the composition of tight junction (TJ) proteins, such as claudins (Mullin and Snock, 1990). A disbalance of sealing and pore-forming claudins in impaired intestinal barrier function attributable to TNF is often characterized by an uncontrolled permeability to toxins and bacteria, resulting in diarrhea. Nevertheless, the detailed functional and molecular mechanisms of TNF-induced barrier disturbance remain the focus of current research in order to provide improved preventive and therapeutical approaches in the future. Because of the morphological and nutritional similarities between the gastrointestinal tract of pigs and humans, porcine models are suitable for analyzing both pig and human intestinal diseases. However, to date, only limited information regarding TNF effects on porcine epithelial barrier function is available. Therefore, the objective of the present work has been to analyze the functional and molecular impact of the pro-inflammatory cytokine on epithelial barrier function in porcine models. Subsequent to experiments, the effects of TNF on barrier function have been examined more closely, by paying special attention to TJ proteins and TNF signaling. These aspects have been assessed by using two distinct models as explained in the following. 1. The non-transformed cell line IPEC-J2 During the first study described in the present thesis, barrier-disturbing effects of TNF on the porcine intestinal epithelium were examined in vitro by using IPEC-J2 cells. The IPEC-J2 cell line, which originated from the jejunal epithelium of a neonatal piglet, constitutes a well-established model for the analysis of gastrointestinal barrier function (Schierack et al., 2006). Incubation with TNF led to a considerable disturbance of the epithelial barrier, represented by a decreased transepithelial resistance (TER) and an increased paracellular permeability to 3H-D-Mannitol. This barrier damage was accompanied by a significant reduction of the sealing TJ proteins claudin-1, -3, and occludin. Furthermore, incubation of IPEC-J2 cells with TNF led to an increase in the expression of specific TNF receptor-1 (TNFR-1), verifying the self-enhancing inflammatory effect under TNF treatment. Use of ML-7, a specific blocker of the myosin light chain kinase (MLCK), significantly prevented effects on TER and alterations in claudin-3 and TNFR-1 expression. Moreover, cells recovered from TNF-induced barrier loss, as 48 h after removal of the cytokine the TJ proteins claudin-1 and occludin were integrated once again at the functional lateral membrane of the cells. In addition, no significant changes in an ApoTox-Glo assay were observed, excluding an induction of apoptosis by TNF in IPEC-J2 cells. The obtained data from this study explain (i) the barrier-disturbing effect of TNF on TJ composition, (ii) the involvement of MLCK in TNF-induced signaling in IPEC-J2, and (iii) the up-regulation of the specific TNFR-1, underlining the exponential nature of inflammation. 2. The follicle-associated epithelium of porcine Peyer’s patches The second part of the present work examined the effects of TNF on porcine intestinal tissue samples ex vivo by using the Ussing chamber technique. The experiments were conducted by using two different types of tissue, one being the immunological active Peyer’s patch (PP), and the other one being the neighboring villus epithelium (VE), both obtained from adult pigs at a slaughterhouse. The PP is covered by the follicle-associated epithelium (FAE), whose primary purpose is to limit the uptake of antigens from the intestine, and which therefore requires an efficient epithelial barrier (Jung et al., 2010). As one major restriction of the Ussing chamber technique is the experimental time limitation (Pearce et al., 2018), an improved setup was established to analyze the effects of TNF on PP and VE for up to 10 h. An incubation of PP with TNF led to a significant decrease in TER after 8 h, whereas the paracellular flux to 3H-D-Mannitol was unaltered. Western blot analysis and immunostaining revealed a decrease of sealing claudin-1 and -4, whereas the pore-forming claudin-2 was significantly up-regulated and functionally integrated into the TJ structure. In contrast to in vitro experiments, a significant increase of TNFR-2 could be observed in PP FAE after addition of TNF. In adjacent VE, neither TER alterations, nor effects on TJ proteins or TNF receptors could be observed after incubation with the cytokine. This highlights the important role of FAE in intestinal mucosal defense.

A city is a highly complex, anthropogenically constructed system – an urban ecosystem. Researchers that study this system come from very different academic fields, bringing with them their own methods and research questions. From the perspective of (biological) urban ecology, this thesis first takes a step back, and focuses on knowledge production in general academia (chapter 1). The concept knowledge in the dark, or short: dark knowledge, describes the gap between potential and actual knowledge. In chapter 1, several potential reasons for dark knowledge in general are discussed. Focusing on the acasemic system, these are for example loss of academic freedom, research and publication biases, a lack of reproducibility, financial interests and barriers in understanding each other among disciplines and different areas of society. We also discuss potential solutions. One important aspect is rethinking and improving research synthesis and finding ways to bridge language and information barriers both within and beyond the academic system. Chapters 2, 3 and 4 then take up a main theme from chapter 1: research synthesis, and within the setting of urban ecology show how different approaches to synthesis can help bridge communication between researchers within and beyond one discipline (biological urban ecology), identify biases and knowledge gaps, and visualize and summarize available knowledge. The chapters proceed from a very broad perspective on urban ecology to the topic of urban biotic homogenization, and then a very specific aspect within urban biodiversity research: the influence of mowing of urban lawns on arthropods, which is one specific cause of biotic homogenization in cities. In Chapter 2, together with a group of urban ecologists predominantly based in Berlin, I collected 62 research hypotheses from urban ecology. In a second step, my co-authors and I present a first map of these hypotheses in a structured, bipartite network. As urban ecology is a multi-disciplinary field that is of high interest to urban planners and administrations, knowledge transfer between different stakeholders is particularly important. The network we propose consists of four distinct clusters, into which the hypotheses we previously identified can be grouped: (i) Urban species traits & evolution, (ii) Urban communities, (iii) Urban habitats and (iv) Urban ecosystems. This work is intended to grow, and as an invitation to researchers, practitioners and others interested in urban ecology to contribute to collecting additional hypotheses, jointly fill the network (or rather the underlying Wikidata project) with empirical data. Chapter 2 is thus intended as a first step towards an open and community curated knowledge base for urban ecology. Chapter 3 focuses on one of the hypotheses from our network: urban biotic homogenization (UBH). Urbanization, which is restructuring ecosystems at an unprecedented pace, is hypothesized to cause the homogenization of urban species communities. This idea has also been applied to other biodiversity levels like genetic diversity, behavioural diversity, functional diversity, and the like. There is, however, good reason to also formulate a hypothesis predicting the opposite effect: biotic diversification, that predicts species communities (and other levels of biodiversity) to become biologically more diverse because of ongoing urbanization. In chapter 3, I disentangle the different connotations, scales and “auxiliary hypotheses”, i.e., hypotheses that often unspokenly accompany a tested research hypothesis, which have been applied in the research literature on urban biotic homogenization and diversification. Applying the hierarchy-of-hypotheses approach, I systematically map and structure the comprehensive body of literature on UBH, comprising 225 individual tests of the hypothesis from 145 publications. Interestingly, UBH is generally used with two very different connotations in relation to scale (i.e., homogenization across cities versus within cities). There are several strong research biases, for example in relation to taxonomic focus, scale, and study systems. We visualize support and biases in an evidence gap map and provide a bibliographic network of the field. Chapter 4 is a meta-analysis of the impact of reduced mowing frequencies on the abundance and diversity of arthropods on urban grassland sites. It is based on 46 datasets on arthropod abundance and 23 datasets on taxa richness, respectively. As in chapter 3, we report severe geographical biases. While we find a medium positive effect (effect size: g = 0.54) of reduced mowing on arthropod abundance, the effect that reduced mowing has on urban arthropod taxa richness is larger (g = 1.25). Some functional groups benefit more from reduced mowing, especially winged insects, and perceived non-pest species. In the final, General Discussion, I try to connect several points that can be traced to all four chapters and discuss them in the context of urban ecology. These are: knowledge gaps and biases, with a brief discussion of how the concept of dark knowledge can (and should) be relevant to researchers from urban ecology, and research and knowledge synthesis. I finish my thesis by reflecting on how these are important in the context of urban ecological knowledge in the Anthropocene, and how they should be extended in the face of planetary crisis.

The high ammonia emissions associated with pig fattening have serious consequences for the health of the animals, the people who care for them, and the global climate. For example, about 50 % of fattening pigs undergo severe pneumonia with identifiable scarring of the lung tissue in the course of their lives (Hillen et al. 2014; Maes et al. 2001; Grest et al. 1997). The source of this ammonia is degradation of protein within the gut, which is absorbed, detoxified by the liver and renally excreted. Most steps of this process have been investigated in detail. However, the mechanism by which ammonia is absorbed from the intestine continues to be unclear. Previous studies suggest that certain members of the TRP channel family contribute to uptake of ammonia in the form of NH4+ from the rumen. The aims of the present thesis were to investigate evidence for a channel-mediated uptake of NH4+ from the various parts of the porcine intestine, to study the expression of certain relevant members of the TRP family by the gut and to explore the effects of selected phytogenic agonists with a potential effect on these channels. A better understanding of the absorption mechanisms from the gastrointestinal tract of the pig is a prerequisite for the development of rational strategies in breeding and feeding with the aim of reducing ammonia excretion in fattening farms. Within the context of the two studies presented in this thesis, the expression levels of nine different TRP channels were studied and compared at mRNA level in the stomach (cardia and fundus), duodenum, jejunum, ileum, caecum and colon, always distinguishing between tissues of epithelial or muscular origin. While TRPV2, TRPV3, TRPV4, TRPV6, TRPM6, TRPM7, and TRPA1 could be detected in various segments of the porcine gastrointestinal tract, no evidence could be found for the expression of TRPV1 and TRPM8. Two channels with potential relevance for NH4+ transport, TRPV3 and TRPV4, were investigated further at protein level by immunoblot and immunohistochemistry, showing a predominant staining of the apical membrane of the epithelium in all segments. While TRPV4 was expressed throughout the gastrointestinal tract, mRNA data suggest that expression of the full-length TRPV3 protein is limited to those segments with the highest absorption of ammonia, namely caecum and colon. Via the Ussing chamber technique, functional evidence of TRPV3 and TRPV4 was obtained using the selective agonists 2-APB and GSK106790A. In line with a functional expression of these channels, electrogenic transport of NH4+ could be observed and was found to be further enhanced by the removal of divalent cations. In conjunction, the results suggest that the transport of NH4+ across the caecum and colon of the pigs may involve TRPV3, with possible further contributions of TRPV4. In the second study, the electrophysiological effects of the TRPA1 agonist cinnamaldehyde and the TRPV3 and TRPA1 agonist thymol were investigated in the colon of pigs. For this purpose, the Ussing chamber technique and the use of different blockers and solutions were used to investigate the mechanism of action in more detail. It was shown that the effect of cinnamaldehyde in the colon is most likely due to HCO3- mediated secretion by a prostaglandin-mediated signalling cascade following activation of TRPA1. In contrast, the electrophysiological effects after thymol addition were diverse, suggesting different mechanisms of action, which need to be investigated in more detail in further studies. The results presented provide an overview of the expression pattern of nine different TRP channels in seven different parts of the porcine gastrointestinal tract. Furthermore, evidence is presented for the electrogenic transport of ammonia in the form of NH4+. Functional data suggest a direct involvement of TRPV3 and TRPV4 in colonic transport, while TRPA1 modulates transport via a prostaglandin-dependent signalling cascade. By targeted modulation of these channels, e.g. by phytogenic agents, it seems possible to influence the transport and metabolism of cations, including the physiologically relevant NH4+ ion. Compounds with a selective inhibitory effects on the absorption of NH4+ from the hindgut are thus conceivable, but have yet to be developed. However, the use of currently available phytogenic agents, such as cinnamaldehyde, may result in other positive effects, such as the stimulation of bicarbonate secretion with buffering of protons in the lumen.

This thesis attempts to transfer the spotlight upon the political issue about democratization in China to something else that has not been spared enough attention yet. Here it refers to the transformation of governance mode. The rather rapid industrialization and urbanization in the process of modernization in China does not aggravate the swelling of bureaucratic system to the extent that largely increases financial burden, internal disorder, and inefficiency. The maintenance of a stable and controllable government on both national and local level benefits from the transformation of governance mode from command mode to network mode.

RNA polymerase II (Pol II) regulation during early elongation has emerged as a regulatory hub in the gene expression of multicellular organisms. Prior research links the BRD4 protein to this control point, regulating the release of paused Pol II into productive elongation. However, the exact roles and mechanisms by which BRD4 influences this and potentially other post-initiation regulatory processes remain unknown. This study combines rapid BRD4 protein degradation and multi-omics approaches, including nascent elongating transcript sequencing (NET-seq), to uncover BRD4’s direct protein functions.

Applying NET-seq in comparative studies required experimental adaptations. First, analyses with spiked-in mouse cells proved essential for reliable normalization. Second, the study identified a disproportional enrichment of a chromatin-associated RNA class as NET-seq’s major limitation. Incorporating an additional enrichment step solved this problem and significantly increased Pol II coverage.

The resulting high-sensitivity NET-seq method confirmed BRD4’s proposed role in early elongation by revealing a global defect in Pol II pause release upon BRD4 degradation. Observations from proteomics and chromatin immunoprecipitation followed by sequencing (ChIP-seq) experiments suggest that the failed recruitment of Pol II-associated factors (PAF) causes an assembly defect of a competent elongation complex.

Interestingly, the elongation defect also affected transcribed enhancers. Pol II occupancy increased in a region proximal to the enhancer center, strikingly similar to the impaired Pol II pause release at genes. An integrated multi-omics analysis that included genome-wide 3D genome information revealed reduced interactions between these enhancers and other regulatory regions.

Another unexpected result was the widespread Pol II readthrough transcription quantified by the developed readthrough index, revealing an apparent transcriptional termination defect. The implementation of long-read nascent RNA-sequencing (nascONT-seq) combined with a 3’-RNA cleavage efficiency test detected impaired 3’-RNA processing. Notably, those 3’-RNA cleavage defects correlated with the observed termination defects. A potential explanation is the BRD4-dependent recruitment of general 3’-RNA processing factors to the 5’-control region. These observations start to establish regulatory links between 5’ and 3’ control that require further validation. Overall, the results indicate a general BRD4-dependent 5’ elongation control point required for 3’-RNA processing and termination.

Molecular switches can interconvert between two stable states controlled by an external stimulus. They are applied in adaptive materials, molecular electronics, and are needed to develop artificial molecular machines. Molecular switches can be assembled and operated based on noncovalent interactions. A detailed understanding of the involved noncovalent interactions is fundamental to develop new switching functions and operation modes. In this thesis, the redox-switchable units tetrathiafulvalene (TTF) and naphthalene diimide (NDI) are incorporated into crown ethers. The thermodynamic binding properties of crown ethers and sec-ammonium ions were investigated through isothermal titration calorimetry (ITC). The effects of the counterion as well as the structural changes both in the macrocycle and in the axle on the noncovalent interactions in the pseudorotaxanes were identified. Additionally, an organic cage was developed, which can adopt a self-inclusion complex. The cage showed a very strong enthalpy driven binding (Ka > 109 M-1) of cations such as acetylcholine. Interestingly, the binding was also entropically favoured. Based on a toolbox of molecular components of redox-switchable crown ethers and sec-ammonium axles, different functions of molecular switches were constructed using the concepts of self-assembly, self-sorting, mechanical bonding, and multivalency. Switching of a kinetically hindered pseudorotaxane revealed differences in the disassembly timeframe depending on the type of the applied stimulus. Five redox-switchable monovalent rotaxanes with different switching modes were assembled. In two of these rotaxanes a shuttling motion of the wheel along the axle was observed upon switching. In a planar chiral rotaxane, redox-switching resulted in a sign inversion in the electronic circular dichroism spectrum. In a homo[3]rotaxane, attractive noncovalent interactions between two extended TTF units which are incorporated in both wheels were identified. When both TTFs were oxidised to TTF2+, Coulomb repulsion triggers a 180° rotation of the wheels in relation to each other. By applying integrative self-sorting, two different wheels were combined on one axle to form hetero[3]pseudorotaxanes. The self-sorting equilibrium was studied and it revealed a major impact of the smaller second wheel on the hetero[3]pseudorotaxane properties. The construction of four hetero[3]rotaxanes was achieved. The formation of a divalent pseudorotaxane containing TTF and NDI showed positive chelate cooperativity and an emerging intramolecular charge-transfer band confirmed the donor-acceptor interaction between TTF and NDI. The investigation of the redox-switching of a divalent donor-acceptor rotaxane revealed interesting optoelectronic properties.