In the first part of this thesis, the general coordination and organometallic chemistry of technetium was explored. The preparation and reactivity of technetium hydrido complexes based on an improved synthetic protocol for the scalable synthesis of the technetium(III) hydride [TcH3(PPh3)4] was investigated. As a result, the technetium(I) hydride mer-trans-[TcH(CO)3(PPh3)2] became available in scalable amounts, which led to the isolation of a variety of structurally similar technetium(I) complexes containing two or three carbonyl ligands through its reactions with Brønsted acids. Reactions with Brønsted acids of weakly coordinating counter-ions resulted in the formation of the labile aqua complex mer-trans-[Tc(OH2)(CO)3(PPh3)2]+ that has been used as a labile starting material for ligand exchange reactions with various ligands of general interest to the coordination chemistry of technetium. The non-protic dimethylsulfide surrogate mer-trans-[Tc(SMe2)(CO)3(PPh3)2]+ was developed and successfully used for the preparation of novel organometallic technetium complexes, for example the isolation of the first acetylido complexes of technetium was accomplished. Throughout these studies, a series of structurally related compounds containing the mer-{Tc(CO)3}+ or cis-{Tc(CO)2}+ cores was prepared, that enabled a detailed evaluation of structural relationships among technetium complexes having the same core structure but different ligands. Most importantly, 99Tc NMR spectroscopy was proven as an invaluable and highly specific tool for the analysis of the lowvalent technetium carbonyl species. Besides carbonyl complexes, also the chemistry of the low-valent technetium(I) complexes [Tc(NO)(Cp)(PPh3)Cl] and [TcI(NO)(PPh3)(LOMe)Cl] has been investigated. Finally, the reduction chemistry of pertechnetate in highly acidic media was studied resulting in the characterization of the previously unknown, mixed-valence ammonium polyoxometallate salt (NH4)4[{TcVO(TcVIIO4)4}4]. In the second part of this thesis, the coordination chemistry of organoselenium- and tellurium compounds was studied. A method for the easy and reliable preparation of organochalcogenolato complexes from dichalcogenides and metal phosphine complexes was developed using reductionsensitive Schiff’ base substituted dichalcogenides as model compounds. The coordination of one chalcogen atom of the dichalcogenide increases the reactivity of the second chalcogen atom through an increase in its electropositive σ-hole and, thus, enables the nucleophilic attack of the in situ released reducing agent. The method was expanded from the originally studied rhenium(V) oxido and arylimido complexes to nickel, palladium and platinum complexes in the oxidation state +2. With phosphine-free starting materials, the Schiff’ base substituted dichalcogenides form clusters of varying structure. For the first time, the interconversion of the gyrobifastigial and cuboid-like structures of tetrameric Pd4Chal4 central units for compounds with the same chemical composition has been observed. Lastly, large bowl-shaped telluroxane clusters have been investigated. The coordination of the central unit of each half-shell in the large telluroxane-clusters to calcium in a crown-ether-like fashion led to a loss in color. The shift of the UV-VIS absorption could be explained by DFT calculations due to an increased delocalization of electron density in the telluroxane framework.
View lessThe field of optogenetics is in constant development while searching for new optogenetic tools that can be used to control nerve cells, stimulus and optical control of neuronal activity. Among the candidates to be developed as new optogenetics tools, are the LOV (Light Oxygen Voltage) proteins which are ubiquitous photosensors in all domains of life. Channelrhodopsins are frequently used in optogenetics due to their light-gated cation activity, which is a unique characteristic among the ion channels.
Channelrhodopsin-1 from Chlamydomonas augustae (CaChR1) exhibits slower inactivation under continuous illumination and a shift in the visible maximum absorption compared to Channelrhodopsin-1 and Channelrhodopsin-2 from Chlamydomonas reinhardtii. These features are advantageous when developing optogenetic tools, securing CaChR1 as a viable candidate for research. Here, by variation of amino acid chains, an investigation of the molecular changes in the photocycle of CaChR1 was conducted. Steady-state and time-resolved molecular spectroscopy revealed the unusual deprotonated cysteine amino acid (C174) in the ground state. It was also established that C174 plays a central role as the internal proton donor to the retinal Schiff base during the decay of the P2380 intermediate state, which is concomitant with the deprotonation of D299 and protonation of E136 and E169 amino acids.
Among the LOV domains an investigation on a variant of the short LOV protein from Dinoroseobacter shibae was conducted. The DsLOV-M49S has the advantage of having an exceptionally fast photocycle compared to other LOV domains. This unique feature of DsLOV-M49S enables the performance of time-resolved molecular spectroscopy and the characterization of the thio-adduct state’s formation. Using an infrared quantum cascade laser (QCL), the evolution of the weak changes in absorption were successfully tracked for the S-H vibration of a single cysteine residue. The changes indicate the deprotonation of C72 with a time constant of 12 µs, which coincides with the formation of the FMN-cystenyl-thiol-adduct state.
This thesis focuses on a deep biophysical mechanistic investigation of these two systems candidates to optogenetic tools. The experiments performed elucidate the choreographed sequence of proton transfers, changes in electron densities, spin alterations, and transient bond formations and breakages; all of which supplement and refine the mechanistic interpretation of the light-induced structural changes in LOV domains and CaChR1.
View lessDuring cancer development, malignant tumours accumulate genetic and epigenetic alterations that cause dysregulation of gene expression and cellular processes. Since the regulation of gene expression controls many cellular processes, understanding the transcriptome of malignant tumours provides insights into the biology of cancer. Key technology for the molecular analysis of whole cancer transcriptomes is next- generation sequencing (NGS) of RNA (RNA-seq) from bulk tumours. However, to derive information about cancer transcriptomes from RNA-seq data, a variety of computational tools and analyses are needed. The following work presents two cancer transcriptome studies addressing the computational analysis of RNA-seq data from colorectal carcinomas (CRC) and medulloblastomas (MB) by applying statistical and machine learning (ML) methods.
CRC is a clinically challenging disease because only a fraction of tumours responds to available chemo- and targeted therapies. Functional loss of the tumour suppressor APC has been suggested to represent the initial mutation, activating Wnt signalling. Additional events include mutually exclusive mutations in the RAS/RAF proto-oncogenes as well as in the TGFβ, PI3K, and TP53 pathways. Routinely used biomarkers of resistance to the EGFR inhibitor cetuximab are RAS/RAF mutations that activate signalling downstream of EGFR. Still, a fraction of wild-type CRCs is resistant to cetuximab treatment. Addressing the need for a better molecular understanding of CRC in precision oncology, the OncoTrack consortium (Innovative Medicine Initiative) designed a multi-omics strategy integrating the establishment of a pre-clinical platform for CRC organoid and animal models. In the study presented below, we focused on the integrative analysis of gene expression and drug response data obtained from patient-derived xenografts (PDXs) treated with cetuximab. Applying statistical methods, we identified a signature of 241 genes associated with response to cetuximab, which allowed us to dissect the expression profiles of responding and non-responding CRC. We used a support vector machine (SVM), a supervised ML algorithm, to obtain a gene-expression-based classifier predictive of response to cetuximab. Here, we selected 16 highly predictive genes using multiple SVM recursive feature elimination. The built classifier outperformed RAS/RAF mutations as a predictor of cetuximab response and performed well in RAS/RAF-wild-type CRC that currently lacks biomarkers of cetuximab treatment outcome in clinical practice.
The second study addressed the molecular analysis of MB. MB, a tumour of the cerebellum, is the most common malignant brain tumour in children. Transcriptome profiling of MB using microarrays had revealed four tumour subgroups, namely WNT, SHH, Group 3 and Group 4, each related to distinct genetic alterations, molecular profiles, and clinical features. Recurrent mutations mainly cause pathway activation in WNT and SHH MB, respectively, whereas in Group 3 and Group 4 MB, gross chromosomal alterations are more prevalent and tumours express a specific cell-type- rather than a pathway-related gene signature. Additional molecular complexity has been identified within these four main subgroups, which could be dissected further into subtypes. However, the gene regulatory networks that contribute to the molecular heterogeneity in MB are only partially known, and the role of long non-coding (lnc) genes remains poorly addressed in this disease. To gain further insights into the molecular biology of MB, the PedBrain project was founded within the ICGC framework. As a contribution to this project, we sequenced and computationally analysed 164 MB RNA-seq samples. Addressing the heterogeneity of MB, we identified and validated molecular subclusters within the four main subgroups. Subgroup- and subcluster-specific gene expression profiles were analysed by functional enrichments and gene regulatory networks (GRNs) inferred from gene expression data. These GRNs revealed communalities and differences in gene regulation among subclusters and subgroups. By estimating the impact of TFs, we could unravel master regulators of subcluster-specific gene expression in a systematic fashion for the first time and highlight unknown regulators of Group 4 MB. Furthermore, we characterised lnc genes that were differentially expressed in MB. Among these genes, we identified 20 lnc genes that show brain- development-associated expression patterns, which is of interest due to the embryonic origin of MB. We identified a co-expression cluster that accumulates known cancer-related lnc genes and associates these genes with cancer-promoting protein biogenesis. Survival analyses revealed the lnc gene MEG3 as a prognostic marker in SHH and Group 4 subcluster, potentially acting as a tumour suppressor that negatively regulates cell cycle and TGFβ receptor expression.
View lessChildren grow and adapt very obviously and constantly, but they are not the only ones. People change across their whole life span. Empirical evidence shows that also adults’ personality (i.e., openness to experience, conscientiousness, extraversion, agreeableness, neuroticism) and their social participation (e.g., social network size) change up until old age. Even though the phenomenon of lifelong personality trait change is widely accepted, the causes of change and thus the possibilities to intervene are much debated currently. So far, little attention has been paid to the role of social participation with regard to personality change and vice versa. Firstly, this thesis introduces the literature on personality development and social participation over the life span (Chapter 1), followed by a review of the empirical evidence on changes in personality traits and in social behavior, i.e., in-person social contacts, leisure activities (Chapters 2-4). In order to further contribute to research on life span development and catalysts of personality change, the following research questions (RQ) will be investigated: RQ 1. Can an intensive cognitive training change personality trait, especially openness to experience, in the long run? (Study 1, Chapter 2) RQ 2. How does in-person social contact frequency develop across the adult life span? (Study 2, Chapter 3) RQ 3. Are changes in frequency of different leisure activities and overall (social) participation associated with personality change? – If so, which direction do they take? (Study 3, Chapter 4) The data to answer these questions are derived from two data sets. Firstly, the COGITO study that was originally designed to investigate day-to-day fluctuations in cognitive performance and to examine transfer effects of trained cognitive tasks on nontrained cognitive tasks (Chapter 2). Secondly, the German Socio-Economic Panel Study (SOEP), which is a large, ongoing survey of private households and individuals in Germany which was initiated in 1984 (Chapters 3 and 4). The results of the empirical chapters lead to the following answers (A) to the research questions: A 1. Cognitive training does not affect changes in any facet of openness to experience in the long-run. This was true for young and old participants as well as for men and women. A 2. The frequency of in-person contacts with family members remains relatively stable across the life span. The frequency of visits to and from nonfamily members (neighbors, friends, and acquaintances) declines, following a cubic trajectory and drops below the frequency of family visits once people are in their mid-30s. A 3. Frequency of different leisure activities and the overall participation are most strongly associated with openness to experience trait at a between-person level. However, at within-person level, reciprocal effects are discerned only for extraversion with overall participation and socializing (i.e. in-person contacts). These results are integrated into the literature on personality development and social psychology in the general discussion and implications for research and practice are discussed respectively (Chapter 5). In conclusion, this thesis minimizes some gaps in the literature by comprehensively investigating mechanisms of personality change and patterns of social behavior in adulthood.
View lessThis thesis analyses the evolution of the sexual and gender-based violence prohibition norm at the International Criminal Court. Underpinned by social constructivist research on international norms, insights into the appropriate application of legal norms, as well as feminist institutionalist and legal perspectives, the evolution is identified as an outcome of a socialization process with the norm’s appropriate application. The case study, based on qualitative data analysis, embraces seven stages of this process, each accompanied by a triangulation inquiry. Connecting research on the evolution of norms in international relations with that on resistance practices against international courts, this analysis studies the constellation and agency of the involved actors, institutional and structural as well as socio-political factors. The findings of this study should contribute to the understanding and conceptualization of the evolution of international norms, specifically in the fields of human rights and gender justice from an interdisciplinary perspective, joining political, social and legal aspects through a feminist lens.
View lessTitle of the PhD-Thesis: From porcine skin samples in situ to three-dimensional human skin constructs in vitro. Studying skin with a focus on the 3R principles. Chapter 1 gives a general introduction to the importance of animal models, focusing on porcine models as well as on in vitro models in skin research. Chapter 2 presents a literature review of research on pigs as animal models for human skin in skin research and of in vitro models of skin research. Furthermore, the principle of the 3Rs is reviewed. Chapter 3 states the objectives and hypotheses of this thesis. Chapters 4 and 5 cover the two main publications for this thesis. Chapter 4 reports on the comparison between abdominal human skin and four different areas of pig skin (the ear, the flank, the back, and the caudal abdomen). The skin samples were examined by light microscope (LM), transmission electron microscope (TEM) and immunohistochemistry. In addition, skin permeability studies were performed. The results of this study show both the similarities and differences in histological and ultrastructural features. The epidermis of the examined regions in both pigs and humans, except for the stratum corneum, is of similar thickness. Although the number of corneocyte layers was not different in the two species, the human corneocyte layer was thicker than that of the pig. The dermal structure of humans and pigs is similar, the thickness of the human one is more similar to the one of the porcine flank and back region. The ear and caudal abdomen of the pig showed a thinner dermis when compared with those of humans. The epidermal-dermal thickness ratio of the porcine back, flank and abdomen was similar to that of humans. The dermo-epidermal length was not found to be different in humans and pigs. This is significant since the skin´s barrier function depends on this interface. The number of hair follicles and arrector pili muscles of the porcine abdominal and ear skin was different from that of the human skin. The number of sweat glands of the four areas of pig skin was not significantly different from that of the human skin. The number of blood vessels in the human dermis was significantly lower than in the pig dermis. Chapter 5 reports on the comparison between the two types of in-house skin constructs and human skin as examined by light and transmission electron microsopy. Data were analyzed by semi-quantitative and qualitative methods. The two types of skin constructs included a construct consisting of keratinocytes and fibroblasts only (type 1, KCFB) and another construct made of keratinocytes as well as fibroblasts and vascular endothelial cells (type 2, KCFB_EC). Both types of skin constructs showed all strata as known from human skin. When compared with the skin constructs without EC or with normal human skin, the skin constructs with endothelial cells were characterized by unorganized epidermal layers, significantly more mitotic cells in the stratum spinosum, more layers of the stratum granulosum and more keratohyaline granules. Chapter 6 discusses whether specific skin regions of domestic pigs were suitable for human skin replacement. According to the results reported in the first section, the back region, particularly of the German Landrace breed, had superior skin characteristics to those from the flank, the abdominal and the caudal ear regions. The dermal thickness of the back region was comparable to the thickness of human abdominal skin. It is possible that the caudal ear skin could be used as a model in studies of chemicals utilizing the trans-follicular route for their absorption. The second section addressed the morphology and ultrastructure, and the effect of endothelialization on epidermal differentiation in two types of skin constructs. The epidermis in both the KCFB and KCFB-EC skin models had a similar overall architecture and ultrastructure to native skin. When the KCFB-EC and KCFB models were compared, however, there were several differences. The KCFB-EC constructs featured more mitotic cells, a considerable epidermal differentiation, and a significantly more disorganized epidermal architecture. The data supported the hypothesis that VEGF promotes epidermal thickness and keratinocyte proliferation. VEGF was obtained from both culture medium and keratinocyte culture. Increased VEGF levels may play a crucial role in these issues. In addition, no vasculogenesis was observed in the fibroblast matrix of the KCFB-EC constructs. Due to a lack of interaction between endothelial cells and fibroblasts, endothelial cells failed to form capillaries. To build a stable dermis, fibroblasts and endothelial cells quantity must be optimized. Thus, the epidermis may be initiated by seeding keratinocytes on top of the optimal dermis.
View lessZiel dieser Arbeit ist die Zusammenstellung der Studien zur Ernährung der Katze bis 2020 in einer zusammenfassenden Übersichtsarbeit. Hierzu wurden zunächst 1164 Literaturquellen nach gezielten Kriterien systematisch ausgewählt, katalogisiert und entsprechenden zuvor festgelegten Themenfeldern zugeordnet. Es fanden sodann für diese Arbeit 491 Literaturquellen tatsächlich Berücksichtigung für die Auswertung. Katzen weisen als obligat carnivore Tierart verdauungs- und ernährungsphysiologische Besonderheiten auf. In der Ernährungsforschung nimmt die Beurteilung des Energiebedarfs seit Mitte der 1990er Jahre einen großen Stellenwert ein. Bei der Durchführung von Studien zum Energiebedarf ist es von großer Bedeutung, einen standardisierten Versuchsaufbau zu konzipieren, der eine einheitliche Methodik nutzt und beeinflussende Komponenten wie die Körperkonstitution, Geschlecht, Kastrationsstatus und Alter der Katzen berücksichtigt. Die Forschung zum Proteinbedarf beginnt schon etwa 10 Jahre früher in den Mittelpunkt des Interesses zu rücken. Die Katze kann direkt nach der Futteraufnahme die Aminosäuren zur Gluconeogenese nutzen. Sie ist auf der anderen Seite aber nur limitiert in der Lage, den katabolen Stoffwechsel der Enzyme im Proteinstoffwechsel an ein proteinarmes Futter anzupassen. Das dritte große Themenfeld in der Ernährung der Katze umfasst die Forschung zum Kohlenhydratstoffwechsel seit den 1980er Jahren. Der zunehmende Einsatz von Kohlenhydraten vor allem bei der Trockenfutterherstellung machte es notwendig, sich mit der Verdauung, Akzeptanz und möglichen Nebenwirkungen für die Fleischfresser zu befassen. So weist die Katze eine verringerte Aktivität der für die Verdauung von Kohlenhydraten verantwortlichen Enzyme auf. Interessanterweise ließ sich in mehreren Studien eine gute Verdaulichkeit vor allem von thermisch aufgeschlossenen Kohlenhydraten nachweisen. Allerdings lässt die Akzeptanz eines Futter mit mehr als 30 % Kohlenhydratanteil deutlich nach. Kontroverse Diskussionen gibt es im Hinblick auf den Einfluss von der Trockenfuttergabe auf ernährungsbedingte Erkrankungen. Hier liegt der Fokus bei der Erforschung der Entstehung von Übergewicht und Diabetes mellitus. Der Zusammenhang zwischen dem Phosphatgehalt im Futter und der Ausbildung einer CNE bei bisher gesunden Katzen bzw. der Progression der Erkrankung bei erkrankten Katzen ist aktuell im Mittelpunkt der Forschung. Auch stieg das Interesse in den 2000er Jahren bei den Studien zu anderen Mineralstoffen in Futtermitteln, da hier ein direkter Bezug zu ernährungsbedingten Krankheiten wie der FLUTD und der CNE hergestellt werden konnte. Recht übersichtlich sind die Studien in der Rubrik Fette und Vitamine, die vor allem in den 1980er und 1990er Jahren durchgeführt wurden. Hier scheinen die Ergebnisse wenig Anlass für weitere Studiendesigns zu liefern. In der Gesamtheit stellen die hier zusammengetragenen Studienergebnisse die Schwierigkeit verbindlicher und langfristig geltender Aussagen und Empfehlungen zur optimalen Ernährung der Katze dar. So werden die Empfehlungen internationaler Vereinigungen für die einzelnen Nährstoffe immer wieder hinterfragt. Für zukünftige Studien sollte der Fokus auf der Erforschung und vor allem der Prävention von ernährungsbedingten Erkrankungen liegen. Für eine bessere Vergleichbarkeit der Studienergebnisse wäre hierbei eine Standardisierung des Studiendesigns erstrebenswert. Bei aller Sorgfalt in der Erarbeitung eines idealen Fütterungsregimes der Hauskatze wird als individueller und schwer kalkulierbarer Faktor immer der Tierhalter stehen, der in der Lage sein muss, die entsprechenden Empfehlungen bestmöglich umzusetzen.
View lessThermophilic Campylobacter spp. are zoonotic bacteria leading to the most often reported gastroenteritis in the European Union. Campylobacter jejuni and Campylobacter coli are the major species relevant for human campylobacteriosis, which manifests with watery or bloody diarrhea, abdominal cramps, fever and in few cases leads to autoimmune sequelae, such as reactive arthritis, irritable bowel disease and Guillain-Barré syndrome. Even though the pathogens are fastidious in vitro and only grow at reduced oxygen levels, they are very successful in colonizing different warm-blooded hosts and in quickly spreading within a chicken flock. This PhD theses was focused on genomic diversity of C. jejuni and C. coli and the underlying mechanisms, in particular, natural transformation, which is the capacity to take up free DNA from the environment and adapt to changing conditions. We identified strains with ambiguous results in species differentiation by real-time PCR targeting genes, usually distinct for C. coli and C. jejuni. Using next generation sequencing and k-mer analysis the strains were identified as C. coli, harboring a substantial amount of recombined C. jejuni sequences, leading to gene variants. Interestingly, these so-called hybrid strains shared a common set of genes with C. jejuni sequence introgression, which may have a potential role in stress defense. Since the hybrid strains were preferentially isolated from egg shells, which is a dry and harmful environment for thermophilic Campylobacter spp., this may hint at selection for strains which survived harsh environmental conditions. It also demonstrated that Campylobacter is able to undergo extensive genetic exchange. The question arose, under which conditions the pathogen acquires genetic material by natural transformation, leading to the introduction of such an amount of new genetic material. Factors regulating natural transformation and competence development are only poorly understood in C. jejuni. Therefore, we developed a single cell-based uptake assay to monitor competence development. As a fresh field isolate we used C. jejuni strain BfR-CA-14430 which had recently been isolated from chicken meat and belongs to clonal complex 21 (ST44), which is also commonly found in human isolates. For better comparability this strain was distributed for common use in the PAC-CAMPY consortium. Since no sequence data was available we sequenced this strain using short-read Illumina and single molecule real-time (SMRT) long-read sequence analysis. BfR-CA-14430 had a genome size of 1.6 Mb and harbored a 41 kb plasmid. For visualization of DNA uptake, we covalently labelled C. jejuni genomic DNA with a fluorophore and added this labelled DNA to C. jejuni cells under different growth conditions. The results obtained by the single cell assay correlated well with the results obtained by a classical assay approach based on the transformation and subsequent selection for a resistance marker. This showed that the assay is a powerful tool to analyze competence development in C. jejuni. Increase from pH 6.5 to 7.5 resulted in a higher fraction of competent cells. Below pH 5 neither competence development nor DNA uptake was observed. Furthermore, aerobic conditions abolished competence development but not DNA uptake in already competent C. jejuni. These findings suggested a strong regulation of competence development in C. jejuni. We further showed that competence development in C. jejuni did not depend on growth temperatures or carbon dioxide concentrations. Since C. jejuni often resides in the slightly alkaline intestine of poultry, the results implicate extensive genetic exchange in the host. This might be beneficial to switch hosts and/or to survive in the environment. In a cooperation study, the single cell assay was used to check the effect of an immune-stimulative substance, curcumin, which was suggested as a potential treatment option for campylobacteriosis, on natural transformation. The DNA uptake assay did not identify either stimulating or inhibiting effects of curcumin on natural transformation in C. jejuni, which corroborates its application during campylobacteriosis without triggering the adaptive potential of the pathogen. In conclusion, extensive genetic exchange occurs in Campylobacter, potentially enlarging the adaptive potential of the food-borne pathogen. This might support the pathogen as successful colonizer and survivor. Besides, high genetic plasticity may hinder correct diagnostics and has to be taken into account for continuous monitoring of Campylobacter variants. It remains important to study natural transformation in detail in order to reduce the adaptability of thermophilic Campylobacter spp. in the future.
View lessA remarkable discovery made in rodents three decades ago demonstrated that the brain reactivates previous experience during sleep and wakeful rest. This phenomenon, since known as replay, has been implicated in a variety of cognitive functions, ranging from spatial navigation and episodic memory consolidation to planning and decision-making. At the same time, research in machine learning (ML) has found that experience replay can substantially improve the performance of artificial agents. Together, these observations have spawned the idea that replay supports behavior by retrieving information from abstract internal representations of the environment. How the interplay between replay and internal task representations supports learning and decision-making in humans is still not well understood. In addition, investigating replay in humans is challenging because replay is fast, sequential, and occurs throughout the brain, but current non-invasive neuroimaging methods offer either sufficient temporal or spatial resolution, but not both. This dissertation consists of three publications that offer a theoretical and empirical perspective on the role of replay in learning and decision-making as well as methodological advances for the study of replay in humans using functional magnetic resonance imaging (fMRI). In Paper I, we provide a review of the recent computational and neuroscientific literature on replay and elucidate how replay can improve learning and decision-making in both biological and artificial agents. We identified five key computational functions of replay which include faster and data efficient learning, less forgetting, the reorganization and augmentation of experiences, planning, and generalization. We also discussed the benefits of reactivating abstract internal representations instead of recapitulating veridical experiences, and explored the idea that replay could be involved in learning which representation is useful for a given task. In Paper II, we developed and experimentally validated multivariate analysis methods for fMRI that allow studying the sequentiality and speed of fast-paced neural event sequences, like replay, with anatomical precision in humans. The results showed that probabilistic fMRI pattern classifiers make it possible to detect the sequential order of neural image representations at speeds of up to 32 milliseconds between sequence items. Finally, applying these methods to fMRI data from awake resting-state scans, we could differentiate fast from slow neural sequences that occurred at random time points and found evidence for sequential replay of task-related stimulus sequences during post-task rest. In Paper III, we investigated how humans form predictive internal representations of the statistical relationships between task stimuli and if the brain reactivates sequences from these internal representations during short pauses from ongoing behavior. The results showed that humans learned the higher-order relationships between consecutively presented images in the form of a predictive cognitive map that represents each item in terms of the subsequent items that follow from it. Applying the fMRI methods developed in Paper II to neural data during short pauses interleaved with task performance, we found that participants reactivated upcoming stimulus sequences that were most likely given this predictive internal representation. In summary, this dissertation makes three major contributions. First, linking findings about replay in the neuroscience and ML literature spurs new ideas how replay can support learning and decision-making in both biological and artificial agents. Second, novel methods to characterize the speed and sequentiality of replay with spatial specificity using fMRI have the potential to foster future insights into the role of replay in the human brain. Third, studying how replay interacts with internal representations opens avenues to further understand how the reactivation of experience supports adaptive behavior in machines and humans.
View lessRydberg atoms are the “giants” in the world of atomic physics. Their highly excited valence electron gives them remarkable properties, such as a long lifetime, large dipole moments and great sensitivity to external fields rendering them ideal tools for the study of quantum effects and quantum technology applications. Quantum technologies promise to outperform their classical counterparts in terms of speed, security, accuracy and performance while presenting us with new challenges. This thesis explores different applications of Rydberg atoms for quantum technologies from a quantum control perspective with a special focus on quantum measurements.
Many quantum technologies require the fast and accurate engineering of quantum states to achieve peak performance and avoid decoherence. I tackle this requirement by employing quantum optimal control theory (OCT) and demonstrate fast and accurate navigation in the high-dimensional Stark manifold of rubidium Rydberg atoms. This is illustrated by means of two examples: the circularisation of Rydberg atoms and the preparation of a Schrödinger-cat-like state which promises quantum sensing of electric fields at the fundamental limit using alkali atoms.
While Rydberg physics has focused for a long time on alkali atoms, it is worth to extend the study to alkaline-earth atoms, as their second valence electron promises new opportunities for quantum technology. However, modelling alkaline-earth atoms is challenging due to electronic interactions. I therefore develop an improved single-active-electron model and optimise the parameters to maximise the agreement with spectroscopic data. This enables OCT applications of strontium which require a precise model for the quantum system under consideration.
Fast protocols are an important tool to avoid decoherence. However, quantum technologies rely on accessing the system for information processing and read-out. The study of open quantum systems is thus crucial for realising quantum technology in presence of decoherence. I therefore propose a quantum simulator for open quantum systems which enables the systematic study of dissipation, memory effects and their interplay for quantum control. The simulator is based on frequent measurements of a system by a meter which can be realised, for instance, by a photonic mode of a cavity and a Rydberg atom, respectively.
The strong interaction of composite systems involving Rydberg atoms lends itself not only for quantum simulation but also for spectroscopy. Many standard detection methods for quantum objects are based on their destruction, e.g. by absorption or ionisation. Förster resonance energy transfer (FRET), on the other hand, is a popular spectroscopic tool and promising candidate for the non-destructive detection of polar molecules. The large size of Rydberg atoms, however, suggests a breakdown of the commonly employed dipole-dipole approximation. To enable the study of FRET, I simulate the collision between a Rydberg atom and a polar molecule considering dipole-dipole, -quadrupole and -octupole interactions. The computed scattering cross-sections allow for studying of the multipolar character of FRET and its spectroscopic potential.
View lessThis dissertation examines the introduction of the technologies of motion pictures and recorded sound in Argentina, Chile, and Uruguay and analyzes the changes they triggered in communication and cultural production. It reconstructs the lives and careers of a group of immigrant men who sold, distributed, and produced movies and records for the urban markets of these three countries, shaping the emergence of new media and the integration of the region into a global entertainment market. This dissertation poses the question of what impact the positions of Argentina, Chile, and Uruguay in the global economy had on the changes triggered by the introduction of motion picture and recorded sound technologies. It argues that cities in these three countries became part of a global entertainment market between the 1890s and 1920s in a particular way, which had important implications for cultural production and communication. Unlike in the United States and Europe, where production was the most dynamic sphere and producers the most powerful actors, the growth of the sphere of consumption drove the consolidation of distribution networks and the production of films and records in the case of the countries under examination in this study. Through advertisement and based on knowledge about the users’ expectations and demands, retailers shaped the appropriations of the new technologies. Entrepreneurs followed a strategy of vertical integration by moving from commercialization to distribution, establishing agreements with European and US based companies for the rights of their products in the region, further competing against each other for the bigger share. This had consequences for production and for the discourses that these media spread and contributed to shape alleged national cultural expressions, since producers favored certain genres and contents in which they could offer a distinctive feature based on local cultural references.
View lessBHLHE40 ist ein Transkriptionsfaktor aus der Familie der basic helix-loop-helix Proteine, der hauptsächlich als Transkriptionsrepressor fungiert. Die repressive Wirkung wird meist via direkter DNA-Bindung oder indirekt, über Protein-Protein-Interaktion mit anderen Transkriptionsfaktoren, vermittelt. BHLHE40 ist involviert in die Steuerung der Adipogenese im Fettgewebe. Darüber hinaus lieferten Voruntersuchungen zu der vorliegenden Arbeit Hinweise darauf, dass BHLHE40, über die Beeinflussung von PPARα- und ChREBP-Zielgenen, an der Regulation des Energiestoffwechsels in der Leber beteiligt ist. Diese Arbeit sollte dazu beitragen, die Rolle von BHLHE40 während der Adipozytendifferenzierung noch besser zu verstehen, sowie potenzielle neue Funktionen von BHLHE40 im Energiemetabolismus der Leber aufzudecken. In diesem Zusammenhang wurde zusätzlich mittels Chromatin-Immunpräzipitation nach neuen genomischen BHLHE40-Bindungsstellen in der Leber gesucht. Zunächst konnten die Ergebnisse einer anderen Arbeitsgruppe bestätigt werden, dass eine Bhlhe40-Überexpression in 3T3-L1 Zellen zu einer Inhibition der Adipogenese führt. Diese hemmende Wirkung scheint allerdings nicht, wie vorgeschlagen, über eine direkte Repression der Pparγ2-Promotoraktivität vermittelt zu werden. Vielmehr deuten Ergebnisse dieser Arbeit darauf hin, dass BHLHE40 die Differenzierungskaskade upstream von PPAR2 hemmt. Weiterhin konnte gezeigt werden, dass ein Bhlhe40-Knockdown den gegenteiligen Effekt auf 3T3-L1 Zellen hat und die Adipozytendifferenzierung fördert. Anhand von Bhlhe40-Knockdown und -Überexpression in primären murinen Hepatozyten, konnte im zweiten Teil dieser Arbeit festgestellt werden, dass BHLHE40 die Expression bestimmter PPARα- und ChREBP-Zielgene fördert. Insbesondere die Expression von Hmgcs2, limitierendes Enzym in der Ketogenese, wird durch Bhlhe40-Knockdown und Bhlhe40-Überexpression signifikant reguliert. Zusammen mit der Tatsache, dass BHLHE40 unter Fütterung in der Leber hochreguliert wird, deutet dieses Ergebnis darauf hin, dass BHLHE40 an der Entstehung der diabetischen Ketose unter Hyperglykämie beteiligt ist. Zuletzt wurden mittels BHLHE40-spezifischer Chromatin-Immunpräzipitation in Leberproben von gefütterten, männlichen C57BL/6J Mäusen neue genomische BHLHE40-Bindungsstellen in der Nähe der Gene Klf10 und Dgat2 detektiert.
View lessIn dieser Studie wurde der Einfluss,den verschiedene Schweregrade von Geburtshilfen bei Kühen auf die folgende Laktation hatten betrachtet. Es wurden retrospektiv Daten zu 261 Geburten, an denen eine tierärztliche Geburtshilfe geleistet worden war, in drei Gruppen eingeteilt: mittlere Geburtshilfe (MG), schwere Geburtshilfe (SG) und Kaiserschnitt (KS). Zu jeder Schwergeburt wurde ein Kontrolltier ausgewählt, das ohne tierärztliche Hilfe im selben Zeitraum gekalbt hatte und im selben Alter, in derselben Laktation war und derselben Rasse angehörte. Studien und Kontrolltiere wurden hinsichtlich Milchleistung, Milchinhaltsstoffe, Fruchtbarkeit und Abgangsraten von Kuh und Kalb untersucht. MG hatte nur geringe Auswirkungen auf die Milchleistung, Fruchtbarkeit und die Abgangsrate der Kühe. Verglichen mit den Kontrolltieren gingen mehr SG (28.1 vs. 25.8%) und KS (30.3 vs. 15.8%) ab. Bis zum 200. Laktationstag waren weniger Tiere tragend in der SG Gruppe (48.3 vs. 61.8%) und in der KS Gruppe (48.7 vs. 69.7%). Der Unterschied war nur für die KS Tiere signifikant. Die SG zeigte keinen Einfluss auf die Milchleistung, während die KS tiere eine signifikant niedrigere Milchleistung in den ersten 5 Kontrollmonaten als ihre Kontrolltiere aufwiesen. Im Vergleich zu der Kontrolltieren steigen die Kosten mit der Schwere der Geburtshilfe an (MG 58.86, SG 130.51, KS 236.61 / Tier).
View lessLocated in the northwest of China and southeast of the Eurasian Steppe, Xinjiang has always been considered one vital meeting point that bridges East China, Central Asia, and Europe. The bridging road was then named the “Silk Road.” The earliest historical documents in the Han dynasty recorded the first official expansion carried out by Zhang Qian, a Chinese envoy, in 114 BC. This expedition put the previous communication between east and west into a formal connection. The languages and cultures of the Silk Road have exchanged various cultures from different regions, including the pre-Han time.
There were several independent small states in the Tianshan Mountain ranges before the Han government, like Yuezhi, Wusun, Xiongnu, etc. These states have displayed similar nomadic lifestyles with each other and other cultures from the north. Therefore, communication must have existed long before the Han Dynasty. The prehistoric Xinjiang must have several external/internal communication approaches that developed in many aspects.
This dissertation intends to organize the prehistoric Xinjiang materials, reconstruct the prehistoric Xinjiang framework, and provide new research to study subsistence patterns, economic strategy, social status, and state formation.
The whole dissertation is articulated as follows:
Part I. An introductive chapter provides the background and outlines of the research. Chapter 1 is devoted to the geographical and climate descriptions. The topography characteristic of Xinjiang can be summarized as “two basins sandwiched between three mountains” (Altai Mountain, Tianshan Mountain, Kunlunshan Mountain, Junggar Basin, and Tarim Basin). Its large scale contributes to variable climate differences from north to south: mountain-oasis-desert condition. Xinjiang is generally in the central continent and exhibits a typical continental arid climate. The dry weather has preserved the ancient relic remains in good condition.
Chapter 2 revived the research history concerning the Xinjiang prehistoric study, which can be divided into four phases: 1. 1900-1940s, 2. 1940-1970s, 3. 1970-1990s, 4. 2000-present. Even after more than 100 years of exploration, the comprehensive research on prehistoric Xinjiang is still limited due to the lack of excavation materials and little multidisciplinary cooperation.
Chapter 3 concerns the research problems, methodology, and related concepts during the research. After more than 100 years of research, it is evident that Xinjiang prehistoric cultures have been closely connected with other neighboring cultures, and this chapter mainly describes the possible related cultures in the nearby regions: Yamnaya culture, Afanasievo culture, Andronovo culture, Siba culture, and Kayue culture, etc.
Part II regards the prehistoric materials that have been published yet, which is the central part of this dissertation. In this part, Chapter 4 views the “Paleolithic Age” sites that are dated between 240,000-4,000 BP, while Chapter 5 is about the “Bronze Age”- “Iron Age” sites, according to the geographical order. Each site is described based on the smallest excavation unit, trying to provide the most detailed information for the reconstruction. Each section of this part follows the framework of 1. Location, 2. Research History, 3. Findings, 4. Age, 5. Interpretation.
Part III is the discussion part, in which it first establishes the prehistoric chronological sequence and then divides the whole prehistoric Xinjiang into 11 cultural zones: (A). Southern Hami Zone, (B). Eastern Hami Zone, (C). Balikun region Zone, (D). Turfan Basin Zone, (E). Altai Mountain Zone, (F). Western Junggar Zone, (G). Mid-northern Tianshan Mountain Zone, (H). Mid-southern Tianshan Mountain Zone, (I). Lop Nur Zone Southern, (J). Tarim Zone, (K). Pamir Plateau Zone. According to the chronological framework and the separate cultural zones, this chapter proposes the possible cultural communication route in prehistoric Xinjiang.
The conclusive part, Chapter 7, summarizes the prehistoric material and the cultural zones and provides a general picture of prehistoric Xinjiang before Han Dynasty.
The prehistoric Xinjiang started around 300,000 BP in the Altun Mountains region, when two spots exhibit the earliest lithic percussion assemblage. Several Paleolithic sites were distributed in the Altai Mountain, Hami Basin, and Tarim Basin until 4,000 BP, respectively; however, these lithic traditions did not transform into the Neolithic technologies in the following centuries. The arrival of Bronze Age cultures from central Asia leads the Paleolithic Xinjiang into the Bronze Age around 2,500 BC. The outside Bronze Age culture from the west and east contribute to the unique Xinjiang native cultures, with the coexistence of painted pottery wares and bronze items. The continuous communication helped the development of metallurgy; at the beginning of the first millennium BC, iron came into use in Xinjiang prehistoric sites. The transmission of tool production and continuously external/internal cultural communication contributed to the revolution on subsistence strategy. The rise of horse nomadism with metal harnesses and weapons has led to frequent conflicts and expansion of local territory. The adoption of agricultural practice assured a relatively stable sedentary life.
In general, this thesis intends to first build a fundamental database for prehistoric Xinjiang research, and this database will be enriched with more discoveries and research results. Only by collecting all the published data can we have a basic knowledge for the further study. In addition, this thesis also provids a new general chronological sequence of Xinjiang prehistory, and discussed the possible cultural interaction route according to the cultural comparisons.
View lessParental self-efficacy is an essential predictor of beneficial parenting practices, parenting skills, and positive child development (Albanese et al., 2019; Ardelt & Eccles, 2001; P. K. Coleman & Karraker, 2000; T. L. Jones & Prinz, 2005; Schuengel & Oosterman, 2019; Stievenart & Martinez Perez, 2020; Verhage et al., 2013; Wilson et al., 2014; Wittkowski et al., 2017). It describes the parents’ belief in their efficaciousness in influencing the child and its environment in such a way that it supports child development (Ardelt & Eccles, 2001). Parental self-efficacy as a parental belief (Sigel & McGillicuddy–De Lisi, 2002) is part of the home learning environment. The home learning environment has proven to be an important factor for beneficial child development and later school performance (Kluczniok et al., 2013; Lehrl et al., 2012; Sammons et al., 2015; Tamis- LeMonda et al., 2017). Studies indicate that the home learning environment can be structured into structural family characteristics (e.g., socio-economic background or family language), beliefs (e.g., parental self-efficacy), and processes or process quality (e.g., parent-child activities), whereby the processes have a direct effect on child development (Anders et al., 2011; Kluczniok et al., 2013; NICHD Early Child Care Research Network, 2003). This thesis follows the structure of the home learning environment, called the home learning environment model, and presents its component’s interrelationships. In the first study, the construct of parental self-efficacy is investigated in more detail. The construct of parental self-efficacy and, in particular, its content-specificity is not well understood: Parental self-efficacy can either refer to parents’ general perception of how well they judge themselves in their role as parents or refer to a specific parental task. To investigate this, it was tested whether (a) general and task-related parental self-efficacy could be assessed separately or (b) be mapped in a hierarchical model. Results indicate that general and task-related parental self-efficacy are separate dimensions. Furthermore, general and task-related parental self-efficacy were tested for differences in family characteristics. Results suggested that parents with a non-German family language experienced lower general parental self-efficacy and perceived themselves to be less self-efficacious in caring for a sick child. Parents with a university degree felt more efficacious in communicating a responsible media use but less efficacious in caring for a sick child than parents who did not have a university degree. The second study investigated the relationship of parental self-efficacy with family characteristics and home learning activities of native-born German parents and parents with a Turkish immigration background. Little is known (a) about the relationships between structural characteristics, parental self-efficacy, and home learning activities, especially for Turkish immigrant families with average educational levels and income, and (b) whether parental self-efficacy and home learning activities and their relationship are affected by the parents’ immigration background. Results showed that parental self-efficacy and the educational level but not the immigration background were significant predictors of home learning activities. The immigration background was related to the number of home learning activities via parental self-efficacy. However, there was no direct relationship between the immigration background and the home learning activities. This indicates the importance of parental self-efficacy for home learning activities regardless of the immigration background. Surprisingly, parents with a Turkish immigration background felt significantly more self-efficacious than native-born German parents. The third study investigated the relationship of parental self-efficacy and home learning activities with child outcomes at the children’s transition from preschool to elementary school. The interplay between parental self-efficacy, home learning activities, and preschool children’s socio-emotional and language skills has not yet been investigated. By linking these variables, this study went beyond previous research that concentrated on relationships between two factors. Findings indicate that the more self-efficacious parents felt, the more home learning activities they offered, and the higher they rated their children’s language skills at age 5. Moreover, parents who felt more efficacious in supporting their children’s language skills also described their children as having fewer socio-emotional problems. Also, parents whose children were about to transition from preschool to elementary school did not significantly undertake more school-preparatory home learning activities than parents of children who were not to enter elementary school. This thesis contributes to better understand the structure of parental self-efficacy in terms of the relationship between different levels of measurement. Furthermore, this thesis was able to show that parents with an immigration background do not generally perceive themselves as less self-efficacious in parenting their children, but that other family characteristics and the context are also decisive for this relationship. Finally, parental self-efficacy emerged as a significant predictor of the number of home learning activities, emphasizing the importance of parental self-efficacy for improving the home learning environment.
View lessThe experience of prolonged stress at the workplace is associated with a variety of adverse health outcomes among employees. If job demands are high and job-related stress is chronic, employees are at risk of developing physical and mental health problems. A common health problem among working populations is burnout, a syndrome that results from prolonged exposure to job demands that exceed the individual’s abilities to cope. An occupational group that is especially vulnerable to develop burnout are police officers, who are exposed to high job demands and serious stressors on a daily basis. The aim of this thesis is to identify factors that protect against work-related strain in policing, with a special focus on the beneficial role of leadership for workplace health promotion. Results of study 1 indicated that job demands, operationalized by high workload and assaults by citizens, were associated with higher levels of depression and anxiety levels among police officers, mediated through emotional exhaustion, the core dimension of burnout. On the other hand, social support by colleagues, shared values and positive leadership climate constituted job resources that were negatively associated with the experience of depression and anxiety. Furthermore, job resources buffered the effect of job demands on emotional exhaustion, indicating that the more resources are available in the work context, the lower is the negative impact of job demands on police officers’ mental health. In study 2 the concept of health-oriented leadership was applied to the context of police work. The results confirmed the beneficial impact of health-oriented leadership on police officers’ health. It was associated with more well-being and lower levels of burnout, depression and musculoskeletal problems. Moreover, health-oriented leadership was positively associated with work-related health behaviors (self-care) of subordinate police officers. Thus, health-oriented leaders promoted police officers’ self-care, which was associated with higher levels of well-being in turn. This implicates that police leaders do not solely affect officer health and well-being by creating favorable working conditions but also by promoting officers’ own health-related behaviors. According to the well-established effort-reward imbalance (ERI) model, job rewards in terms of money, esteem, and career opportunities counterbalance the health-impairing impact of job demands. Leadership plays only a minor role in the operationalization of the reward dimension in the ERI model. The aim of study 3 was thus to enhance the ERI model by adding the concept of health-oriented leadership and to apply it to the context of police work. The results showed that high work effort was associated with higher levels of burnout among police officers. Furthermore, both job rewards and health-oriented leadership were associated with lower levels of burnout. However, only health-oriented leadership, but not job rewards, buffered the health impairing effects of high work effort on burnout levels. In summary, the results of all three studies point to the crucial role of leadership for the prevention of psychological strain and the promotion of health in policing. Police officers especially seem to benefit from leaders who adopt a leadership style that is not only characterized by health-promoting behavior, but also by a heightened awareness for specific health issues at the work and a sense of responsibility for health concerns. The findings of this thesis provide valuable directions for future research and practical interventions for promoting healthy working conditions in the challenging and demanding job of police officers.
View lessDie Verkehrswende, der Umbau des Verkehrssystems hin zu einer ökologisch nachhaltigen Mobili-tät, ist ein komplexer gesellschaftlicher Transformationsprozess. Der Wandel erfordert, neben der Schaffung entsprechender politischer Rahmenbedingungen und dem Einsatz neuer Technologien, tiefgreifende Änderungen von Einstellungen und Verhaltensweisen sowie kulturell geprägter Deu-tungsmuster in der Gesellschaft. Unter welchen Bedingungen sich derartige Veränderungen auf der Ebene des Individuums und auf der Ebene sozialer Strukturen ergeben können und wie diese Ebe-nen miteinander wechselwirken, ist jedoch nicht ausreichend erforscht. Ziel dieser kumulativen Dissertation ist es, auf theoretischer sowie empirischer Basis ein agentenbasiertes Modell der Ein-stellungs- und Entscheidungsänderungen der Verkehrsmittelwahl zu schaffen. Ich beziehe mich dabei auf die kognitionswissenschaftliche Forschung zur Rolle von Emotionen bei der Informati-onsverarbeitung und Entscheidungsfindung, auf Forschungsarbeiten zu der Wirkung sozialer Ein-flüsse aus den Bereichen der Sozialpsychologie und Soziologie sowie auf die umweltpsychologische Forschung zur Segmentierung von Zielgruppen. In Studie 1 wurde anhand eines Vignettenexperiments und eines kognitiv-affektiven Modells dyadischer Kommunikation untersucht, welchen Einfluss die Verwendung emotionaler Sprache im Zuge persuasiver Kommunikation auf die Informationsverarbeitung von Menschen hat. Die Ergeb-nisse zeigen, dass die Tendenz zur motivierten Informationsverarbeitung (motivierte Kognition) durch die Valenz und den Grad der Emotionalität in der Kommunikation beeinflusst wird. Mithilfe des Modells können die beobachteten Effekte durch den Mechanismus der emotionalen Kohärenz erklärt und in ihrer Wirkung auf mentale Strukturen geschätzt werden. In Studie 2 wurden die Einstellungen und affektiven Bedeutungen einer breiten Palette von konventionellen und neueren Verkehrsmitteln untersucht. Auf Basis der affektiven Wahrnehmun-gen konnten unterschiedliche Mobilitätstypen identifiziert werden. Darüber hinaus zeigt die Studie, dass die typspezifischen affektiven Bedeutungsmuster die Bereitschaft, emissionsarme Verkehrsmit-tel zu nutzen, im hohen Maße bestimmen. In Studie 3 wurden die theoretischen und empirischen Ergebnisse aus den vorangegangenen Studien in dem agentenbasierten Modell InnoMind (Innovation diffusion driven by changing Minds) zusammengeführt. Die Simulationsszenarien zu unterschiedlichen Fördermaßnahmen von Elektromobilität verdeutlichen, dass die Wirksamkeit der Instrumente durch die zielgruppenspezifi-schen Einstellungsmuster und sozialen Interaktionen der Verkehrsteilnehmerinnen und Verkehrs-teilnehmer beeinflusst werden. In Studie 4 wurde das Modell InnoMind genutzt, um die einstellungsverändernden Effekte von Informationskampagnen zur Nutzung von Carsharing zu untersuchen. Das Vorgehen verdeutlicht die Flexibilität und Adaptivität des Simulationsansatzes. Darüber hinaus zeigt die Studie, dass die veränderte Darstellung der Mobilitätsoptionen in den Kampagnen deren Wirkung in bedeutsamen Maß beeinflussen kann. Insgesamt unterstreichen die Ergebnisse die Bedeutung affektiv-emotionaler Prozesse für die Einstellungsbildung und -änderung. Die Verarbeitung von (sozialen) Informationen unterliegt Ver-zerrungen, die zu einer Konstruktion einer konsistenten Repräsentation bestehender Überzeugun-gen und Emotionen führen. Diese auf individueller Ebene wirkenden Mechanismen haben in Wechselwirkung mit sozialen Kommunikationsprozessen und Informationsflüssen einen entschei-denden Einfluss auf die Dynamiken im Zuge gesellschaftlicher Transformationen. Das in dieser Arbeit entwickelte agentenbasierte Modell ermöglicht es, derartige komplexe In-teraktionsprozesse und Dynamiken zu analysieren. Auf der Grundlage kognitionswissenschaftlicher, sozialpsychologischer und soziologischer Theorien sowie umfassender Empirie erweitert es die bis-herige Forschung zu Meinungsdynamiken und sozialen Einflüssen mithilfe sozialer Simulationen. Zudem vermittelt das Modell handlungsrelevantes Wissen, um die Akzeptanz der Verkehrswende in der Gesellschaft zu fördern.
View lessDie KMK hat diagnostische Kompetenzen als eine der vier zentralen professionsbezogenen Kompetenzen von Lehrkräften herausgestellt, die es bereits im Studium vorzubereiten gilt. Bislang ist das Angebot an evaluierten Interventionen zur Förderung, vor allem in der universitären Ausbildungsphase, allerdings überschaubar. Dabei kann professionelles diagnostisches Vorgehen bereits im Lehramtsstudium vorbereitet werden, indem neben deklarativem Wissen auch prozedurales diagnostisches Wissen gefördert wird (diagnostische Expertise). Die Förderung prozeduralen Wissens ist jedoch mit Herausforderungen verbunden, weil dabei praktische Erfahrungen essentiell sind. In der vorliegenden Arbeit wird die Entwicklung, Erprobung und Evaluation einer fallbasierten Lerngelegenheit vorgestellt, die den Aufbau prozeduralen Wissens von Lehramtsstudierenden unterstützt. Im Rahmen komplexitätsreduzierter, realistischer Fallvignetten wird damit auf einen Diagnoseanlass vorbereitet, der weitreichende Konsequenzen hat: die Feststellung von Lernbesonderheiten. Dieser Diagnoseanlass erfordert sogenannte formelle Diagnosen, die im Rahmen eines regelgeleiteten diagnostischen Prozesses unter Anwendung standardisierter diagnostischer Testverfahren erstellt werden. Zur Vorbereitung auf diese anspruchsvolle Aufgabe üben die Studierenden im Fallinventar die Vergabe von Diagnosevermutungen sowie die Ableitung von pädagogischen Anschlusshandlungen ein. Bei der Bearbeitung des Fallinventars zeigte sich, dass den Studierenden die Ableitung von Anschlusshandlungen noch schwerer fällt als die Vergabe von Diagnosevermutungen. Diese Schwierigkeit konnte dadurch erklärt werden, dass die Studierenden formelle diagnostische Informationen noch nicht systematisch genug nutzten und dass sie ihre Empfehlungen nicht auf Grundlage der Diagnosen vergaben. Die Fähigkeit zur Vergabe von Empfehlungen konnte erfreulicherweise durch die Arbeit mit dem Fallinventar verbessert werden, indem prozedurales Wissen trainiert wurde. In Kombination mit einer aufgabenbasierten Übung konnte andererseits deklaratives Wissen gefördert werden, das die Trefferquoten bei Diagnosevermutungen erhöhte. Außerdem konnten erste affektiv-motivationale Voraussetzungen geschaffen werden, die die Wahrscheinlichkeit diagnostisch kompetenten Verhaltens in der späteren Berufspraxis erhöhen. Um diese Voraussetzungen zu stabilisieren und weiter auszubauen, bedarf es allerdings weiterer Lerngelegenheiten, die eine schrittweise Praxisannäherung im Lehramtsstudium ermöglichen. Die Ergebnisse erweitern die Befundlage zur Förderung diagnostischer Kompetenzen im Lehramtsstudium und haben Implikationen für die Modellierung diagnostischer Kompetenzen, die bislang die Qualität der Anschlusshandlungen unzureichend berücksichtigt.
View lessPhänomene der Immersion gehen häufig mit dem Wirkungsversprechen einher, Rezipierende möglichst komplett in eine Umgebung, Fiktion oder Parallelwelt einzutauchen. Insbesondere der Topos einer ‚totalen‘ Immersion suggeriert, dass Rezipierende physisch, psychisch oder emotional derart eingenommen werden, dass sie nicht nur das Vermögen verlieren, zwischen Realität und Fiktion zu unterscheiden, sondern auch, dass ihr Reflexionsvermögen zugunsten eines unmittelbaren, intensiven Erlebens eingeschränkt werde. Die vorliegende Studie zeigt am Beispiel immersiven Theaters jedoch, dass es gerade die emotionale Involvierung ist, die Prozesse der Reflexion auslöst – und eine solche, den Diskurs prägende, binäre Denkfigur die Komplexität zahlreicher Immersionsphänomene deshalb nicht angemessen erfassen kann. Vor dem Hintergrund der transdisziplinären Immersionsforschung differenziert die Studie zunächst zwischen immersiven Aufführungsdispositiven und immersivem Theater im engeren Sinn. Letzteres zeichnet sich dadurch aus, dass Zuschauer:innen nicht nur in einen multisensorischen Erfahrungsraum, sondern zugleich in eine geschlossene, gestaltete Weltversion eingelassen werden. Für die Analyse der Publikumsinvolvierung im immersiven Theater wird eine polyperspektivische Szenen- und Situationsanalyse vorgeschlagen. Diese fokussiert anhand ausgewählter Sequenzen die Relation von Aufführungsdispositiv und Zuschauer:innen im Hinblick auf konstellierte Selbst-/Weltverhältnisse. Ausgehend von der These, dass die verschiedenen Modi der Involvierung (räumlich, haptisch-taktil, olfaktorisch, figurenperspektivisch oder handlungsbezogen etc.) wirkungsästhetisch auf Vereinnahmung zielen, zeigen die Analysen, wie Zuschauer:innen z.B. von Geruchs- oder Soundwahrnehmungen derart affiziert werden können, dass es sie situativ zu einer bestimmten Re-Aktion drängt. Prozesse der Vereinnahmung werden dabei nicht nur konstitutiv reziprok gedacht, sondern in ihren vielschichtigen, hochgradig ambivalenten Wirkungen beschrieben. Über das Konzept der Vereinnahmung und die Analyse vereinnahmender Publikumsinvolvierung wird eine affekttheoretische Perspektive auf immersives Theater plausibilisiert. Die Studie nimmt damit nicht nur eine wichtige, korpusgebundene Präzisierung des umbrella-Phänomens immersive theatre vor. Sie leistet nicht zuletzt über die Integration von Zuschauer:innen-Interviews zudem eine methodische Erweiterung etablierter Strategien der Aufführungs- und Inszenierungsanalyse und zielt mit dem Konzept der Vereinnahmung auf eine Theoriebildung für Prozesse der Publikumsinvolvierung im Gegenwartstheater.
View lessFung Asseng (馮亞星, 1792–?) und Fung Ahok (馮亞學, 1798–1877), zwei einigermaßen gebildete Matrosen aus der chinesischen Provinz Guǎngdōng oder Canton (廣東), waren die ersten Chinesen, die sich nachweislich in Deutschland aufhielten. In den 1820er Jahren fertigten sie in Halle und Potsdam umfangreiche zweisprachige Handschriften christlichen Inhalts an, in denen sie ihre frühkantonesischen Aussprachen zahlreicher chinesischer Schriftzeichen in das lateinische Alphabet transkribierten. Gleichzeitig berichteten auch einige deutsche Autoren über ihre Sprache. Diese Schriften, die von Asseng und Ahok selbst oder ihren deutschen Mitmenschen produziert wurden und summarisch als die „deutschen Quellen“ bezeichnet werden können, gelten als aufschlussreiche Materialien für die Erforschung der frühkantonesischen Sprache. Sie werden in der vorliegenden Arbeit zum ersten Mal systematisch untersucht, und zwar aus der Perspektive der chinesischen Dialektologie, der Missionarslinguistik sowie der (deutschen) Graphematik. Dadurch können nicht nur zwei historische Varianten des Frühkantonesischen phonetisch und phonologisch rekonstruiert, sondern auch die Transkriptionsregeln herausgearbeitet werden, die im Wesentlichen unter dem Einfluss der neuhochdeutschen Orthographie entstanden sind.
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