University of Konstanz
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Is My Wage Fair? : Validating Fairness Perceptions among Women and Men
No full textThe authors examine gender differences in perceptions of the fairness of one’s own pay. This work differs from previous studies, as the authors not only assess whether women are as likely as men to perceive their pay as unfair at the same absolute wage levels. Instead, they use an innovative methodology based on linked employer-employee data. This makes it possible to compare subjective perceptions of (un)fair pay with the predicted pay of comparable others with the same individual-, work-, occupation-, and firm-related characteristics. The authors use the measurement of how closely a person’s pay aligns with the predicted pay of comparable others as a strictly empirical indicator of whether someone’s pay is fair. Overall, women are as likely as men to perceive a fair wage as unfair or an unfair wage as fair. Although the data at hand do not make it possible to explore the causes of this, or to assess whether women and men used to differ more in their perceptions of fairness, the authors speculate that women today may be more aware of the societal debate about gender-based wage discrimination, and their perceptions of appropriate compensation may be less influenced by gendered comparison groups and gender status beliefs than previous research has suggested.publishe
Pannexin-2 deficiency disrupts visual pathways and leads to ocular defects in zebrafish
No full textPannexin-2 (Panx2) is a unique ion channel localized to ER-mitochondria contact sites. These specialized microdomains are abundant in neurons and glia and essential for cellular signaling and metabolism. While synaptic interactions are well-studied, the role of intracellular contacts, such as those of ER-mitochondrial junctions, in neuronal function and neurodegeneration remains largely unexplored. To investigate the roles of Panx2 in neuronal communication, we examined its expression pattern in the zebrafish brain and used TALEN technology to generate homozygous Panx2 knockout (Panx2Δ11) zebrafish. Our results demonstrate that panx2 mRNA is present in several brain regions, notably in visual centers such as the optic tectum and the thalamus. In 6 days post fertilization TL (Panx2+/+) larvae, Panx2 expression was observed in the retina and the arborization fields of the optic tract. Transcriptome profiling of Panx2Δ11 larvae by RNA-seq analysis revealed down-regulation of genes involved in visual perception and lens development. Behavioral tests showed that loss of Panx2 leads to an altered ability to interpret visual information, such as changes in ambient illuminations, and respond with the characteristic motor action. Additionally, the knockout larvae displayed significantly impaired optomotor response. Lastly, when we tested the retinal structure of adult zebrafish eyes using optical coherence tomography, Panx2Δ11 fish revealed a longer mean axial length and a negative shift in retinal refractive error (RRE) values. Our findings highlight a distinct, novel function of Panx2 in sensory perception and ocular health, beyond its recognized roles in neurodevelopment and cancer.publishe
Thin slices of teaching behavior : Video observation as complement to the assessment of teaching quality and teacher training interventions
No full textIn research on teaching and teachers, there is a need for valid and economic methods of assessing teaching quality. One approach to such assessment of teaching quality is the so-called thin slices method of video observations—short sequences judged by briefly trained raters. Until now, this method has been used on cross-sectional data only, and not in studies evaluating professional development programs of teachers. In this study, ratings of 41 teacher trainees were cross-validated with student judgments (N = 806) of the same observed lessons in the context of a mindfulness intervention study. For the aspects Disturbances, Time Efficiency, and Student Support, the agreement of students’ and external raters’ ratings was established, underscoring the criterion validity. Additionally, ratings based on the thin slices method were sensitive enough to detect general time effects during teacher training and training effects of an intervention for teachers both on classroom disturbances.publishe
Guidance for Good In Vitro Reporting Standards (GIVReSt) : A draft for stakeholder discussion and background documentation
No full textReproducibility of cell culture experiments between laboratories needs to be improved by ensuring more complete reporting of methodology in scientific papers. The minimum reporting standards suggested here cover various cell culture methods including monolayers, stem cells, organoids, and microphysiological systems (MPS). The standards build on existing guidance like Good Cell Culture Practice (GCCP 2.0) and OECD test reporting guidelines on how to quality-assure in vitro work, focusing on transparency and completeness of reporting. Key elements to be reported include full details of cell source and identity, cell quality control and characterization, materials and reagents used, culture conditions and protocols, experimental design, data analysis, data availability, and legal and ethical aspects. For complex models, additional details need to be provided such as cell ratios, microenvironment conditions, functional characterization, etc. The guidance for Good In Vitro Reporting Standards (GIVReSt) is part of a broader initiative of evidence-based toxicology encompassing the improvement of the quality of in vitro studies for safety assessments and regulatory decisions. In summary, GIVReSt addresses incomplete reporting as a major factor affecting reproducibility of cell culture experiments by providing clear standards around transparency and rigor in reporting. The integration of agentic artificial intelligence (AI) is envisioned to streamline compliance checking, providing real-time feedback and accelerating scientific discovery by making high-quality evidence more accessible. This should lead to more reliable cell culture research overall.publishe
Measuring Bound Attention During Complex Liver Surgery Planning : Feasibility Study
No full textBackground
The integration of advanced technologies such as augmented reality (AR) and virtual reality (VR) into surgical procedures has garnered significant attention. However, the introduction of these innovations requires thorough evaluation in the context of human-machine interaction. Despite their potential benefits, new technologies can complicate surgical tasks and increase the cognitive load on surgeons, potentially offsetting their intended advantages. It is crucial to evaluate these technologies not only for their functional improvements but also for their impact on the surgeon’s workload in clinical settings. A surgical team today must increasingly navigate advanced technologies such as AR and VR, aiming to reduce surgical trauma and enhance patient safety. However, each innovation needs to be evaluated in terms of human-machine interaction. Even if an innovation appears to bring advancements to the field it is applied in, it may complicate the work and increase the surgeon’s workload rather than benefiting the surgeon.
Objective
This study aims to establish a method for objectively determining the additional workload generated using AR or VR glasses in a clinical context for the first time.
Methods
Electroencephalography (EEG) signals were recorded using a passive auditory oddball paradigm while 9 participants performed surgical planning for liver resection across 3 different conditions: (1) using AR glasses, (2) VR glasses, and (3) the conventional planning software on a computer.
Results
The electrophysiological results, that is, the potentials evoked by the auditory stimulus, were compared with the subjectively perceived stress of the participants, as determined by the National Aeronautics and Space Administration-Task Load Index (NASA-TLX) questionnaire. The AR condition had the highest scores for mental demand (median 75, IQR 70-85), effort (median 55, IQR 30-65), and frustration (median 40, IQR 15-75) compared with the VR and PC conditions. The analysis of the EEG revealed a trend toward a lower amplitude of the N1 component as well as for the P3 component at the central electrodes in the AR condition, suggesting a higher workload for participants when using AR glasses. In addition, EEG components in the VR condition did not reveal any noticeable differences compared with the EEG components in the conventional planning condition. For the P1 component, the VR condition elicited significantly earlier latencies at the Fz electrode (mean 75.3 ms, SD 25.8 ms) compared with the PC condition (mean 99.4 ms, SD 28.6 ms).
Conclusions
The results suggest a lower stress level when using VR glasses compared with AR glasses, likely due to the 3D visualization of the liver model. Additionally, the alignment between subjectively determined results and objectively determined results confirms the validity of the study design applied in this research.publishe
Development and Validation of the Value of Physical Effort (VoPE) Scale
No full textPhysical effort has instrumental value because it helps people attain their goals. Growing evidence suggests that people might also experience the exertion of effort itself as valuable. To test this idea, we developed and examined the 4-item Value of Physical Effort (VoPE) scale. Across three independent studies (total N = 1364), we established the basic psychometric properties of the VoPE scale and showed consistent associations with measures of sports and exercise behavior. In a study with a longitudinal design, the VoPE scale demonstrated test-retest reliability and forecasted physical activity and exercise behavior. Psychometric network analysis and elastic net regression suggest the VoPE scale’s potential to cover a unique content area and make novel contributions to the prediction of sports behavior. Taken together, the present research yields empirical evidence for the idea that people value physical effort to varying degrees, and that these differences can be efficiently measured with the VoPE scale. We demonstrated reliability and validity of the VoPE scale across three datasets and its ability to predict self-reported sports and exercise behavior. The VoPE scale might thus extend our understanding of how people allocate (physical) effort.publishe
Multi-Objective Mixed-Integer Nonconvex Optimization : Adaptive Relaxation-Refinement Schemes Guided In The Image Space
No full textMulti-objective mixed-integer nonlinear optimization problems frequently arise in real-world applications due to their ability to handle conflicting objectives. Examples can be found in various domains, such as healthcare management, energy network planning, or production planning. Since mathematical models of such applications often result in large and complex optimization problems, efficient algorithms to solve them are necessary.
This thesis proposes a novel deterministic framework for solving multi-objective mixed-integer nonlinear optimization problems. The framework is based on the idea of iteratively refining piecewise linear outer approximations of the feasible set, a well-known technique from single-objective optimization, which is extended to the multi-objective setting for the first time. To guide the refinement process, the framework leverages image space information. This enables individualization of the outer approximations to the needs of the different relevant regions of the image space.
By selecting suitable relaxation and refinement techniques, the framework can be turned into practical algorithms. This thesis presents various options for both, proves correct and finite termination for all resulting variants and provides numerical tests evidencing their applicability.
The proposed framework is related to (box-)enclosure algorithms, a relatively new but increasingly prominent class of algorithms for computing a coverage of the nondominated set. While the framework presented here computes a similar coverage, the output does not strictly belong to this category. To address this, a novel theoretical concept is introduced: pseudo enclosures of the nondominated set, which allows to rigorously describe the output of the proposed algorithms mathematically.publishe
The influence of charge transfer on the emissive properties of pyridine dipyrrolide bismuth complexes
No full textBy judicious ligand design, the quantum yield of the phosphorescence emission from pyridine-2,6-dipyrrolide bismuth complexes increases by up to 20-fold.publishe
MiniMates : Miniature Avatars for AR Remote Meetings within Limited Physical Spaces
No full textRemote meetings using 3D avatars in Augmented Reality (AR) allow effective communication and enable users to retain awareness of their surroundings. However, positioning 3D avatars effectively and consistently for all users in AR is challenging since most spaces, such as offices or living rooms, are not large enough to accommodate multiple life-sized avatars without interference. To address this issue, we contribute MiniMates—a novel approach leveraging miniature avatars, which make it possible to place multiple remote users in a limited physical space. We see MiniMates as complementary to traditional 2D video conferencing and immersive telepresence. Our approach automatically adjusts the formation of avatars and redirects users’ head and body orientation to facilitate communication. Results from our user study (n = 24) show that participants experience a higher sense of co-presence compared to video conferencing, and that MiniMates enabled them to communicate the direction of their interactions non-verbally as well as manage multiple simultaneous conversations.publishe
Exact and Approximate Hierarchical Hub Labeling
No full textHub Labeling (HL) is a state-of-the-art technique for accelerating shortest path computation in road networks. By utilizing precomputed node labels, it can answer distance queries in microseconds on continent-sized networks. The optimization goal is to get correct query results with a minimum number of labels. There is an O(log n) approximation algorithm for the size of an HL with a running time of O(n3 log n). However, existing practical implementations rely mostly on heuristics for a special type of HL, so called Hierarchical HL (HHL). Deciding whether a graph admits a labeling of size at most k is NP-hard for both HL and HHL. For HHL, an O(√n log n) approximation algorithm (called w-HHL) is known. In this article, we devise an exact HHL algorithm for general graphs. We also show that the exact algorithm transfers to Hierarchical Landmark HL (HLHL), which is a generalization of HHL. Moreover, we prove that w-HHL provides a constant factor approximation on trees and investigate for the first time the practical performance of HHL approximation algorithms. We also compare the resulting label sizes to heuristic HHL and HLHL. Our experimental results offer novel insights and show that commonly used methods for HHL are noticeably outperformed by w-H(L)HL on general graphs as well as trees.publishe