University of Konstanz
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Aharonov-Bohm interferometer in inverted-band junctions
No full textInverted-band junctions in two-dimensional materials offer a promising platform for electron optics in condensed matter, as they allow to manipulate and guide electron beams without the need for spatial confinement. In this work, we propose the realization of an Aharonov-Bohm (AB) interferometer using such junctions. We observe AB oscillations in numerically obtained conductance and analytically identify the conditions for their appearance by analyzing the scattering processes at the interface. To support experimental implementation, we also consider junctions with a graded interface, where the potential varies smoothly between the − and -doped regions. Our results reveal an abrupt change in the AB-oscillation frequency, which we attribute to a distinct transition in the hybridization across the interface. We verify that our reported AB oscillations are robust to realistic disorder and temperature decoherence channels. Our study paves the way for realizing the Aharonov-Bohm effect in bulk mesoscopic systems without the need for external spatial confinement, offering new possibilities in electron optics.publishe
Effects of vasectomy on breeding-related movement and activity in free-ranging white-tailed deer
No full textBackground: An abundance of white-tailed deer (Odocoileus virginianus) in suburban communities can lead to problems such as increased deer-vehicle collisions (DVCs), tick-borne illnesses, and forest degradation. Deer populations can be managed using traditional lethal methods; however, these methods are often impractical, ineffective, or socially unacceptable, prompting interest in management alternatives, including fertility control. Some fertility control methods (such as vasectomy, tubal ligation, and porcine zona pellucida-based vaccines) cause unsuccessfully bred females to experience multiple estrous cycles, potentially altering their movement behavior and fine-scale activity. Such changes could increase the risk of DVCs and negatively affect the physical condition of the animals. However, the effects of such treatments on animal behavior remain poorly understood, specifically in terms of breeding-related movements and energetics. This study aimed to evaluate the behavioral impacts of a large-scale vasectomy program on white-tailed deer.
Methods: We conducted a 2-year study using a treatment/control design and analyzed biologging data of white-tailed deer at two sites near New York City, USA. We used a moving-window approach to assess the effects of a large-scale vasectomy program on the seasonal changes in movement behavior (home-range size, distance traveled, diffusion, and excursivity) and fine-scale activity (time spent in low-activity states and the daily number of state transitions).
Results: There were no biologically significant differences in movement behavior or activity trends in either sex between the treatment and control groups. Females in both groups exhibited similar trends in all movement metrics, but females at the treatment site tended to switch between activity states more often in winter. Males at the treatment site expanded their space use less than control males during peak breeding season but otherwise exhibited similar movement behavior trends. Mortality rates and causes were similar at both sites.
Conclusions: The vasectomy program, despite causing extra estrus periods in unsuccessfully bred females, is unlikely to cause appreciable behavioral changes that could exacerbate management-related issues at the time scales investigated. Fertility control methods inducing extra estrus periods could be implemented alone or alongside other strategies to reduce abundant deer populations with minimal impact on behavior.publishe
Artificial Intelligence in Chemistry Research : Implications for Teaching and Learning
No full textArtificial intelligence (AI) has become an important tool in modern scientific research, particularly in chemistry and related disciplines. Despite its growing relevance, the discussion of AI as a tool in research in (secondary) chemistry education remains limited. To address this gap, a review of AI applications in chemical and chemistry-related research was first carried out. According to this, AI is being used most frequently in the fields of pharmacology and biochemistry and is mainly used to make predictions and design molecules. Based on this review a workshop for pre- and in-service chemistry teachers was conducted to provide an initial overview of AI applications in scientific research. The workshop introduced key areas such as retrosynthesis, protein structure prediction, image processing, and autonomous laboratories, fostering awareness of AI’s role in scientific innovation. Participating secondary education science teachers reported an increased familiarity with AI applications and expressed intentions to incorporate these topics into their teaching. The findings highlight the importance of targeted teacher training programs to strengthen Technological Content Knowledge (TCK) in this emerging field. In addition, insights were gained into how such teacher training could be structured in the future to enable teachers to discuss “AI in science” in chemistry lessons. This research emphasizes the need to empower educators to bridge the gap between scientific advancements and chemistry education, preparing students for new career opportunities in AI-driven sciences. Although this work provides initial indications of possible approaches for the integration of AI applications in chemistry teacher education and chemistry lessons, further research is still needed in this area.publishe
The Coral Probiotics Village : An Underwater Laboratory to Tackle the Coral Reefs Crisis
No full textRestoration efforts are urgently needed for the conservation of coral reefs. Among emerging tools, the use of probiotics has shown promise in laboratory settings for improving coral resilience, but their validation under real‐world reef conditions remains limited. Here, we present the Coral Probiotics Village (CPV) as a novel and fully operational underwater research laboratory and a testing ground designed to support the in situ testing of microbial‐based coral restoration interventions. This manuscript describes the design, establishment, and scientific validation of the CPV, including continuous environmental monitoring, a summary of previously developed pilot trials of probiotic applications, and an integration of sensor networks, AI‐assisted reef monitoring, and autonomous technologies. We propose the CPV as a scalable model for integrated coral restoration science and suggest its replication as a tool to accelerate applied reef conservation efforts globally.publishe
Fast quantum gates for exchange-only qubits using simultaneous exchange pulses
No full textThe benefit of exchange-only qubits compared to other spin qubit types is the universal control using only voltage controlled exchange interactions between neighboring spins. As a compromise, qubit operations have to be constructed from non-orthogonal rotation axes of the Bloch sphere and result in rather long pulsing sequences. This paper aims to develop a faster implementation of single-qubit gates using simultaneous exchange pulses and manifests their potential for the construction of two-qubit gates. We introduce pulse sequences in which single-qubit gates could be executed faster and show that subsequences on three spins in two-qubit gates could be implemented in fewer steps. Our findings can particularly speed up gate sequences for realistic idle times between sequential pulses and we show that this advantage increases with more interconnectivity of the quantum dots. We further demonstrate how a phase operation can introduce a relative phase between the computational and some of the leakage states, which can be advantageous for the construction of two-qubit gates. In addition to our theoretical analysis, we experimentally demonstrate and characterize a simultaneous exchange implementation of rotations in a SiGe quantum dot device and compare to the state of the art with sequential exchange pulses.publishe
Preference for symmetry, balance, or proximity in picture aesthetics depends on the method of evaluation
No full textThis study investigates how the method used by participants to assess the beauty of pictures influences their preference for the compositional rules of symmetry, balance, and proximity. The hypothesis that production methods (actively arranging picture elements) prompt a local perspective, favoring proximity, while evaluation tasks (rating precomposed pictures) elicit a global perspective, favoring symmetry and balance, was tested in two experiments. Experiment 1 demonstrated that (positional) symmetry was preferred over balance, and balance over proximity, when participants rated precomposed pictures. Experiment 2, employing a production method with movable elements, showed a frequent use of proximity, yet also a tendency toward (positional) symmetry. The combined results indicate that assessment methods substantially impact the preferred composition rules.publishe
On value and the Commons
No full textApproaches to post-capitalist commons often see them defined by value practices of sharing, reciprocity, solidarity and care in opposition to capitalist market values. This contribution draws on ethnographies of actually existing commons to propose a somewhat different approach to valuation in the commons. Commons are dependent for their reproduction on market valuations, so that it becomes impossible to define commons as social spaces based on their freedom from the market. At the same time, not all market valuations are necessarily capitalistic. Moreover, value practices often considered proper to the commons are not free from dynamics of inequality and power. Focusing on the organization of labour in the commons, this contribution highlights how unevenness might build on or newly create inequalities among the commoners. Consequently, limits to the commons – in terms of their capacity to contribute to post-capitalist transformation – might arise not only from an encroachment of an external capitalist system.publishe
Computational Sarcasm Detection Examined Through the Lens of Psycholinguistics
No full textThis thesis introduces a new framework that examines sarcasm detection from the combined angles of psycholinguistics and computational linguistics. It provides empirical evidence about various factors that cause sarcasm and affect the understanding of it in human communication. The thesis also uses those findings to deepen our understanding of computational sarcasm detection models.
Our first contribution is to reveal how certain important factors relate to the production and interpretation of sarcasm. Two of our experiments examine sarcasm's relation to context, emotion, and communicative intent. We find that emotion and communicative intent are highly associated with the choice to use sarcasm. Using two further experiments, we clarify the relation between speaker perspectives and observer perspectives in navigating communicative situations involving sarcasm---a topic that is an important but neglected aspect of computational sarcasm detection.
Our second contribution is to use the key factors just mentioned as a means of investigating the nature of the automatic sarcasm detection process. We report several patterns identified through three computational experiments, whose united goal is to reveal what kinds of information are encoded in sarcasm detection models, and whether they are similar to the information shown in human behavior. The first finding is that generalizable automatic sarcasm detection is difficult, due to the varied characteristics that sarcasm has. Additionally, we find that the incongruity between the speaker's affect and the content of the utterance makes the identification of sarcasm challenging both for human observers, and language models. Finally, we show that different amounts of context play different roles in computational sarcasm detection, and that this depends on the level of disagreement about sarcasm among human observers.
Our last contribution in this thesis is to introduce a new framework that smoothly integrates experimental and computational investigation of sarcasm, which can be applied to other linguistic phenomena in future research. Our proposed framework, which is proven effective through multiple studies reported in this thesis, should bridge human communication and natural language processing, and contribute to a more multifaceted investigation of natural language in future work.publishe