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Bakterielle Expression eines codon-optimierten Flotillin-1-Fusionsproteins
(2025) Shams Ashaghi, Negin
Das humane Flotillin-1-Protein ließ sich bislang in Prokaryoten nicht gut exprimieren. Der Grund könnte die unterschiedliche Codonbenutzung in Pro- und Eukaryoten sein. Um für Forschungszwecke mehr lösliches Flotillin-1 als GST-Fusionsprotein zu gewinnen, war das Ziel dieser Arbeit „codon-optimierte“ Flotillin-1 Expressionsplasmide zu generieren, diese hinsichtlich Expression und Kulturbedingungen zu untersuchen und zu optimieren, sodass die höchstmögliche Proteinausbeute geschaffen wird. Dabei sollten, nach Optimierung des Leserasters des humanen Flotillin-1 für die bakterielle Expression, die Parameter Temperatur, Induktionszeit und -konzentration untersucht und optimiert, sowie die Expression des optimierten Flot-1-GST Fusionsproteins mit der nicht optimierten Sequenz verglichen werden. Für die Expressionsversuche wurde das codon-optimierte Flotillin-1 als GST-Fusion in den Vektor pGEX-4T-1 kloniert. Nach ersten Expressionsversuchen mit einer 0,2 mM IPTG-Induktion über Nacht und bei Raumtemperatur in den dafür geeigneten kompetenten Zellen BL21, konnte mittels SDS-Gelelektrophorese und Western Blot das expressionsstärkste Klon detektiert werden. Mit diesem wurden alle folgenden Versuche durchgeführt. Es wurden lediglich Vorversuche durchgeführt, um zunächst eine Tendenz zu ermitteln, ob die Optimierung gewinnbringend ist. Als Wirte für das Fusionsprotein dienten BL21-Zellen, nachdem zwischen der Expression in Rosetta DE3 und BL21 DE3 kein deutlicher Unterscheid festgestellt werden konnte. Das humane Flotillin-1 wurde in Rosetta DE3-Zellen exprimiert. Im Rahmen der Expressionsversuche konnte festgestellt werden, dass die IPTG-Konzentration keinen ausschlaggebenden Unterschied bei der Proteinexpression zeigte. Die Untersuchung der Induktionstemperatur konnte aber recht deutlich zeigen, dass die optimale Temperatur zwischen 21°C und 24°C liegt. Was den Vergleich des optimierten mit dem nicht-optimierten Flotillin-1 angeht, so konnte festgestellt werden, dass das optimierte Protein zwar etwas länger braucht, jedoch am Ende das expressionsstärkere Protein ist. Besonders in großen Mengen kann das optimierte Flotillin-1 durchaus von Vorteil sein, jedoch bringt das nicht-optimierte Flotillin-1 auch gute und zufriedenstellende Ergebnisse bei optimierten Expressionsbedingungen (Temperatur, IPTG-Konzentration und Zeit).
Behavioral Benefits of Sensorimotor Predictions: Directing Attention to Maximize Informational Gain During Motor Learning
(2026-01) Brand, Theresa Karoline
Humans internally predict the consequences of their own motor actions using so-called forward models (e.g., Anguera et al., 2009; Flanagan & Wing, 1997; Maurer et al., 2015; Wolpert, 1997). These models simulate the input-output relationship of the musculoskeletal system by integrating sensory information about the current state of the body and the environment with copies of motor commands (Jordan & Rumelhart, 1992; Kawato, 1999; Miall & Wolpert, 1996). The present dissertation investigates functional benefits of such predictive processing, focusing on how sensorimotor predictions shape visual information uptake during motor learning. Specifically, it examines whether sensorimotor predictions direct visual attention toward spatial locations in the environment that are critical for evaluating movement outcomes and adjusting subsequent actions. To address this research question, three consecutive studies were conducted in which eye movements were recorded while participants performed a semi-virtual, goal-directed throwing task. Study I showed that sensorimotor predictions can direct gaze toward predicted action effects. The high informational value of these predictively chosen fixation locations for feedback processing was expressed by a systematic modulation of fixation durations as a function of the movement outcome. Study II demonstrated that the relevance of outcomerelated information is dynamically weighted by both outcome history and the predicted result of a current trial, supporting efficient allocation of attentional resources when multiple gaze targets compete for attention. The comparison of prediction-based top-down attentional mechanisms with salience-driven bottom-up influences in Study III suggests that, with sufficient motor expertise, responsiveness to salient distractors can be selectively modulated in feedback-critical situations. Together, these findings show that during movement execution, gaze can be directed predictively toward information relevant for learning. It can be assumed that this predictive allocation likely ensures that the necessary information for evaluating outcomes and correcting errors is gathered efficiently, particularly in time-critical situations.
Seabird Ontogeny in an Antarctic Environment. Threats, Coping Strategy and its Consequences for Wilson's Storm-petrel Chicks
(2026) Küpper, Nadja Denise
In the extreme environments of polar areas, time for offspring rearing is limited by environmental conditions for many animals. The completion of all body structures and functions in time as well as juvenile survival is linked to efficient development. Additionally, poor weather or foraging conditions may force long-live species with high adult survival rates like procellariiform seabirds to abandon their egg or chick to ensure their own survival in case of elongated breeding periods. Yet, seabird chicks are not only dependent on their parents' care and environmental conditions. During the last decades several anthropogenic threats were detected that may impair chick development and survival.<br> In my thesis I studied anthropogenic, environmental and biological influences on the ontogeny of a procellariiform seabird, the Wilson's Storm-petrel (*Oceanites oceanicus*). Chicks of this species are known to be spontaneously reversibly able to reduce their body temperature and metabolism (facultative hypothermia). This is considered as a survival strategy to preserve energy. I identified body condition for unfed chicks as crucial factor to determine if they could maintain a constant body temperature between 36 °C and 41 °C or not (Chapter 1). After periods of unpredictable feeding that followed snowstorms, facultative hypothermia occurred almost in all chicks for several days until they could recover. Next, I examined the potential consequences of facultative hypothermia use to preserve energy resources, on developmental processes (Chapter 2). Low body temperatures had negative influences on growth, immune parameters, and fat physiology. Growth rates, that were reduced by hypothermia, recovered soon after rewarming. To evaluate if a chick could recover from e ects of facultative hypothermia on other physiological parameters or if its development with regard to these might be slowed down, the available data was insufficient. Lastly, I evaluated anthropogenic pollutants that accumulated in embryos through transfer of nutrients from yolk and albumen, which the mother collects during a prey-laying exodus and deposits to the egg (Chapter 3). Embryos were contaminated with legacy pollutants like polychlorinated biphenyls (PCBs), metabolites of dichlorodiphenyltrichloroethane (DDT), and mercury (Hg), and their PCB concentrations were higher than species with similar diets. Among samples collected during different years, those had higher PCB and Hg concentrations that were about ten years older. Concentrations of DDT metabolites remained similar among the differently aged samples.<br> Concluding, in the current environmental conditions, Wilson's Storm-petrel chicks can cope with weather extremes and unpredictable feeding by using facultative hypothermia, and seem able to recover from physiological setbacks regarding growth during hypothermia. In addition, they face high concentrations of pollutants from the very beginning. As seabird populations are declining worldwide, awareness of threats at all life-history stages is crucial to act successfully on their protection.
Dissonant Heritage: A Comprehensive Analysis of Local Voices, Perceptions, and Challenges in the Development of Dark Tourism in Muynak
(2025) Allaberganov, Azizbek
This dissertation investigates the development of dark tourism in the town of Muynak following the environmental disaster of the Aral Lake. It explores how Muynak transformed into a dark tourism destination, the perceived impacts of this development on local communities, the challenges associated with dark tourism, and the extent to which residents support its further growth. An exploratory sequential mixed-methods design was employed, combining qualitative interviews with experts and stakeholders, quantitative surveys of local residents, as well as informal interviews and field observations to provide contextual insights. Findings reveal that Muynak has gradually transitioned from a leisure-oriented tourism destination to a dark tourism site. Economic and environmental benefits were particularly significant, whereas socio-cultural impacts were comparatively modest. Despite the presence of challenges, local communities generally support further dark tourism development due to its positive economic and environmental outcomes. The study offers both practical and theoretical implications for policymakers and businesses, highlighting strategies to enhance benefits, address challenges, and promote sustainable, community-oriented tourism development.
Between the political and politics: Infrastructure as hegemony in Israel and Palestine
(2026) Nolte, Amina
This cumulative dissertation examines infrastructure as a hegemonic socio-material formation through the case of Israel and Palestine, with a particular focus on Jerusalem and its urban transportation systems. Bringing together perspectives from infrastructure studies, post-foundational political theory, and critical security studies, the dissertation develops the concept of “infrastructure as hegemony” in order to analyze how infrastructures materialize political orders spatially and temporally while simultaneously remaining sites of contestation and negotiation. The dissertation argues that infrastructures are not merely technical systems enabling circulation, mobility, and everyday life, but political projects that embody and stabilize specific relations of power. Drawing on the work of Antonio Gramsci, Ernesto Laclau, Chantal Mouffe, and Henri Lefebvre, the study conceptualizes infrastructures as sedimented political formations that shape social realities while appearing naturalized and apolitical in everyday life. At the same time, infrastructures remain open-ended assemblages through which political struggles, resistance, and alternative futures emerge. Empirically, the dissertation analyzes infrastructures of transportation, security, and urban governance in Jerusalem and beyond. Central case studies include the Jerusalem Light Rail, critical infrastructure and securitization practices, and “Safe” and “Smart City” projects. Through ethnographic fieldwork, discourse analysis, and critical spatial analysis, the dissertation demonstrates how infrastructures participate in processes of territorialization, selective inclusion and exclusion, securitization, and the production of political subjectivities. Particular attention is given to how infrastructures in contested urban environments mediate between state power, everyday life, and competing claims to space, mobility, and belonging. The dissertation further contributes to infrastructure studies by bridging debates between approaches that understand infrastructures as inherently political projects and approaches inspired by Science and Technology Studies (STS) and Actor-Network Theory (ANT), which emphasize relationality and socio-technical assemblages. By combining post-foundational theories of hegemony with methodological attentiveness to infrastructural practices and materialities, the study proposes an integrative framework for analyzing infrastructures as both politically grounded and continuously assembled through everyday practices. Overall, the dissertation highlights the ambivalent character of infrastructures: while they stabilize hegemonic orders and organize circulation, mobility, and security, they also create possibilities for disruption, resistance, and political transformation. In doing so, the study contributes to contemporary debates in sociology, political geography, urban studies, and critical security studies by demonstrating how infrastructures function as central sites through which political power, social order, and conflict are materially produced and contested.