University of Konstanz
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Outfits Serve as Symbols for Overlapping Feminine and STEM Identity Goals
No full textWomen in science, technology, engineering, and mathematics (STEM) juggle between their feminine and professional identity goals. The present research views these struggles from the perspective of identity goal pursuits. Women in STEM may use different, sometimes even symbolic, ways to strive for the two identity goals, for example, by wearing outfits that reflect femininity, their profession, or both. In two studies, we tested to what extent these two goals overlap (are seen as similar) and whether the higher overlap between feminine and STEM professional identity goals is related to the preference for outfits that may serve two goals at the same time or only one of them. In Study 1 (N = 232), we found that willingness to wear an outfit serving both identity goals was positively related to the participant's identity goal overlap. Study 2 (N = 226) showed that overlap was related to the evaluation of the chosen outfits. Participants evaluating the chosen outfits as more multifinal reported higher overlap between the two identity goals.publishe
Canalized light creates directional and switchable surface structures in vanadium dioxide
No full textMaterials with switchable nanostructured surfaces enable optical and electronic functionalities beyond those of natural materials. Here we report the creation of self-organized, re-writable, laser-induced surface structures in single-crystalline vanadium dioxide. We discover anisotropic features caused by canalized surface plasmon polaritons that can only propagate along one crystal axis. The nanostructures remain mostly single-crystalline and preserve the material’s sharp metal-to-insulator transition, enabling femtosecond switching by temperature or light.publishe
Investigating the stress sensitivity of human RNA ligase Rlig1 deficient cells via proteomics and high-throughput screening
No full textMaintenance and repair of polynucleotides are essential processes across all life forms. While DNA repair is well-researched, RNA repair remains largely unexplored. The recent discovery of Rlig1, a 5‘-3’ RNA ligase, could represent a significant step toward the elucidation of further RNA maintenance mechanisms.
This thesis employed various approaches to investigate the functional role of Rlig1 in human cells. In the first chapter of this thesis, confocal microscopy of overexpressed Rlig1 revealed a cytosolic localisation with occasional aggregation. CRISPR/Cas9-generated Rlig1-deficient HEK293 cells displayed no phenotypic differences under physiological conditions but showed heightened sensitivity to oxidative stress induced by menadione. This sensitivity was demonstrated by increased cell death and reduced RNA integrity, particularly of the 28S rRNA. As ROS levels generated by menadione treatment were comparable between the knock-out and the parental cell line, Rlig1 appears to be directly involved in RNA-based stress response. However, attempts to rescue Rlig1-KO cells by retroactive overexpression of Rlig1 were unsuccessful, suggesting additional cellular roles for Rlig1 beyond its enzymatic activity.
In the second part of this work, protein-protein interaction partners of Rlig1 were identified by an affinity enrichment with LC-MS analysis. Enriched protein groups included ribosomal proteins, exosome components, RNA helicases, and DNA base excision repair proteins. Furthermore, Angel2 was enriched and was shown in combination with Rlig1 to repair RNA strands that would result from common RNA strand cleavage events. In further experiments, Rlig1 was proven to spatially interact with the ribosome. While no specific binding pocket of Rlig1 was identified on the ribosome, the RNA ligase seemed to localise preferentially at the large ribosomal subunit, close to rRNA hotspots on the ribosomal surface. Closer examination of the identified DNA base excision repair enzymes revealed that most of the proteins were already known to interact with RNA. The sole exception was the DNA polymerase POLB, which revealed to be able to elongate RNA in subsequent experiments. For this, exclusively nucleotides and no deoxynucleotides were utilised, proving a deliberate extension of RNA by POLB.
In the final chapter of this thesis, a semi-automated high-throughput screening identified ten biologically active small molecules that exhibit synthetic lethality with the knock-out of Rlig1, many of which inhibit NF-κB and/or STAT3, generate ROS, or arrest the cell cycle.
In conclusion, the findings of this thesis provide a basis for future research into Rlig1’s role in RNA maintenance and repair, supporting the hypothesis of previously unrecognised RNA repair pathways.publishe
Stable processes with reflections
No full textWe construct a Hunt process that can be described as an isotropic -stable Lévy process reflected from the complement of a bounded open Lipschitz set. In fact, we introduce a new analytic method for concatenating Markov processes. It is based on nonlocal Schrödinger perturbations of sub-Markovian transition kernels and the construction of two supermedian functions with different growth rates at infinity. We apply this framework to describe the return distribution and the stationary distribution of the process. To handle the strong Markov property at the reflection time, we introduce a novel ladder process, whose transition semigroup encodes not only the position of the process, but also the number of reflections.publishe
Heuristic centred-belief players
No full textStrategic behaviour often diverges from Nash-equilibrium, in particular in inexperienced play. Studying a class of games in which participants choose their payment and receive it as long as their opponent chooses a different amount, I show that none of the popular models of behavioural game theory predicts the predominant aggregate choice pattern consistently. And yet, noisy introspection (Goeree and Holt, 2004) readily accounts for about half of the individual observations. The reason for the apparent paradox and the mis-match of the aggregate data and the models is a disregarded behavioural type that makes up about 25% of the population. These 25% display a specific form of central-tendency bias, holding beliefs that peak in the centre of the option set and that are roughly symmetric. In addition, the players show a more heuristic process translating their belief into actions, as their choices cannot be explained readily by quantal responding. The behavioural pattern of a ‘centred belief’ in connection with boundedly-rational decision-making is present also in another prominent game from the literature on behavioural game theory, the 11–20 game. Finally, I show that classifying players as ‘heuristic centred-belief types’ by one game’s beliefs has predictive power for behaviour in the other game.publishe
Neuroscience and climate action : intersecting pathways for brain and planetary health
No full textThe climate crisis and the human brain are intricately connected. Climate change impacts neurocognitive health, while climate actions both shape and are shaped by the brain. However, research examining these connections remains scarce. This review highlights how neuroscience can deepen the understanding of the reciprocal relationship between climate action and the brain. First, we discuss how both individual and collective climate action can, directly and indirectly, benefit our brain health, mental health and cognitive functioning and how emphasising this holds the potential of harvesting self-interest as a driving force for change. Second, we explore the role of the brain’s emotional and decision-making systems in motivating climate action. We also discuss neuroscience’s potential to predict population-level behaviours and aid in the systematic development of interventions. By addressing current knowledge gaps, we identify the next steps for deepening our understanding of the interwoven connections between climate action and the brain.publishe
Reinforcement learning approach for finding exchange-only gate sequences for CNOT with optimized gate time
No full textExchange-only quantum computation is a version of spin-based quantum computation that entirely avoids the difficulty of controlling individual spins by a magnetic field and instead functions by sequences of exchange pulses. The challenge for exchange-only quantum computation is to find short sequences that generate the required logical quantum gates. A reduction of the total gate time of such synthesized quantum gates can help to minimize the effects of decoherence and control errors during the gate operation and thus increase the total gate fidelity. We apply reinforcement learning to the optimization of exchange-gate sequences realizing the CNOT and CZ two-qubit gates which lend themselves to the construction of universal gate sets for quantum computation. We obtain a significant improvement regarding the total gate time compared to previously published results.publishe