University of Konstanz
KOPS - The Institutional Repository of the University of KonstanzNot a member yet
31050 research outputs found
Sort by
Having a choice of means gears incomplete runners into more effective goal engagement : The effects of deliberative mindsets on the pursuit of identity goals
No full textWhen individuals committed to a certain long-term identity goal fall short of relevant activities, they experience the state of self-incompleteness. This motivational state leads them to prioritize the identity goal pursuit by engaging in self-symbolizing behaviours. The present research investigates whether inducing a deliberative mindset in incomplete individuals by offering a choice will lead to a stronger preference for more effective options. In four studies, committed runners (N = 625) chose between two available options. In Studies 1 and 2, runners who experienced self-incompleteness were more likely to choose a more effective massage roller than runners who experienced self-completeness. In Studies 3 and 4, incomplete runners preferred a more effective phone application than complete runners. In Study 4, this effect was independent of a social reality induction. Further analyses revealed that effectiveness was related to the perceived effort of an option. Even though from a rational point of view people should prefer options that require less effort, participants committed to the identity goal of being a runner preferred to deal with their self-incompleteness feelings by engaging in the more effective but effortful means.publishe
Spin-split Andreev bound states and diode effect in an Ising superconductor Josephson junction
No full textThe transition-metal dichalcogenides featuring Ising spin-orbit coupling in so-called Ising superconductors offer a unique system to study the interplay of singlet and triplet superconductivity. The presence of high critical fields, spectral properties such as the mirage gap, and field-tunable charge and spin currents in Ising superconductor Josephson junctions are some of the important features. In this Letter, we study an Ising superconductor Josephson junction with a transparent interface and show that Andreev bound states are spin split due to a relative misorientation of in-plane fields in the superconducting contacts. Correspondingly, supercurrent-phase relations display a strongly nonsinusoidal behavior. Introducing additional spin-polarized channels with low transmission results in a nonreciprocal current-phase relation with a diode effect that can be tuned by the in-plane exchange fields. The diode efficiency reaches high values of the order of 40% and is not sensitive to disorder in the junction. Such structures can be realized in van der Waals heterostructures of two-dimensional superconductors and magnets.publishe
Microenvironments of black-tip reef sharks (Carcharhinus melanopterus) provide niche habitats for distinct bacterial communities
No full textAnimal holobionts constitute diverse yet interconnected landscapes of microenvironments that harbor specific bacterial communities with distinct functions. An increasing body of literature suggests a partitioning and distinct functional profiles of bacterial communities across shark microenvironments, which has led to the proposition that beneficial bacterial functions may contribute to shark health. Here, we provide a first assessment of bacterial communities in different microenvironments of black-tip reef sharks ( Carcharhinus melanopterus ), the most abundant reef shark species across the Indo-West Pacific. Collecting samples from 34 sharks from the Amirante Islands, Seychelles, we characterized the corresponding bacterial communities of two external skin locations, within the buccal cavity, and of the cloaca (representing the gut microbiome) using 16S rRNA gene amplicon sequencing. Overall, shark-associated bacterial communities were distinct from seawater, and skin, buccal, and cloaca samples were distinct from each other. Shark cloaca samples and seawater exhibited lower bacterial alpha diversity and richness compared to the other microenvironments. Predicted functional profiles and Linear Discriminant Effect Size analysis suggest potential differences in metabolic pathways present in the different shark-associated bacterial communities and in the seawater. Taxonomy-based functional inference suggests cloaca-associated bacterial communities specialize in the consumption and breakdown of various food items. Taken together, our data suggest distinct bacterial niche habitats within the ‘microbial landscape’ of black-tip reef sharks, as indicated by distinct bacterial communities and their predicted metabolic functions. Future (meta)genomic and functional work will help reveal potential roles of bacteria in the health of their shark hosts.publishe
Success Factors of a Large-Scale In-Service Teacher Training in Computer Science
No full textThere is an increasingly strong demand for in-service teacher training, especially in computer science and digitalisation-related fields. However, such post-qualification programmes face significant challenges for both lecturers and participants: Heterogeneity regarding prior knowledge, differing individual timetables, workload of the primary job, and a wide geographic distribution of the participants require programmes that serve a high degree of flexibility. Since 2018, we have addressed these challenges with a blended learning, Bologna-compliant programme, which trains around 200 participants annually. Despite its high workload and comprehensive scope of content, it has a dropout rate of less than 2% and a very high overall satisfaction (94% were satisfied or very satisfied). In this paper, we introduce our programme, recount our lessons learned, and present an evaluation of 327 questionnaires former programme participants have answered. As a result, we identify 27 success factors for large-scale in-service teacher training in blended learning formats.publishe
Spatial Ecology and Home Range Drivers of the Weyns's Duiker (Cephalophus weynsi) in Rainforest Habitat
No full textIn Central Africa's tropical forests, duikers (Cephalophus spp.) are essential seed dispersers and prey for apex predators and humans. However, little is known about their spatial ecology, with no studies available for medium-sized species south of the Congo River. Here, we study forest duiker spatial use in the buffer zone of Salonga National Park, Democratic Republic of the Congo. We assess capture success of (1) collective day capture with nets and (2) collective night capture with head-torches and use GPS/VHF collars to investigate species-specific home-range (a) size, (b) use and (c) overlap. Across 7 months, 47 capture attempts allowed collaring 13 Weyns's (C. weynsi), two bay (C. dorsalis), and one black-fronted (C. nigrifrons) duiker, with similar success between techniques. Weyns's duikers mean home range size was 29.38 ha, with stable core areas and dynamic boundaries. While one breeding pair showed 72.80% overlap and a mean interindividual distance of 288 m, overlap in non-breeding pairs ranged between 4.5% and 52.2%, with an average interindividual distance of 533 m. Our assessment of the spatial use of Weyns's duikers suggests that anthropogenic disturbances might affect spatial behaviour and reproductive success. Further research on the spatial ecology of forest ungulates is key to improving conservation strategies.publishe
On the (<sub>2</sub>)-condition of edge rings for cactus graphs
No full textA cactus graph is a connected graph in which every block is either an edge or a cycle. In this paper, we will examine cactus graphs where all the blocks are 3-cycles, i.e., triangular cactus graphs, of diameter 4. Our main focus is to prove that the corresponding edge ring of this family of graphs is not normal and satisfies Serre’s condition (2). We use a criterion due to Katthän for non-normal affine semigroup rings.publishe
Bidding in multi-unit auctions under limited information
No full textMulti-unit auctions frequently take place in environments with limited information, such as in new markets and under volatile macroeconomic conditions. We characterize optimal prior-free bids in such auctions; these bids minimize the maximal loss in expected utility resulting from uncertainty surrounding opponent behavior. We show that optimal bids are readily computable in this environment despite bidders having multi-dimensional private information. In the pay-as-bid auction the prior-free bid is unique; in the uniform-price auction the prior-free bid is unique if the bidder is allowed to determine the quantities for which they bid, as in many practical applications. We compare prior-free bids and auction outcomes across auction formats; while outcome comparisons are ambiguous, pay-as-bid auctions tend to generate greater revenue and welfare than uniform-price auctions when bidders' values are dispersed. We also compare outcomes in limited-information environments to outcomes in high-information environments, modeled as bidders playing Bayes-Nash equilibrium, and show that Bayes-Nash outcomes dominate prior-free outcomes when the auction is competitive.publishe
How does using an AR learning environment affect student learning of a radical substitution mechanism?
No full textAs the use of augmented reality (AR) in educational settings grows, it becomes increasingly important to understand how to use AR in classrooms. Here, we present an AR learning environment that we designed for teaching an organic chemistry reaction mechanism in high school chemistry classes. This new environment was tested in six tenth-grade chemistry classes (upper secondary) taught by five different teachers in three different schools over the course of five months and evaluated for effectiveness. Students completed knowledge tests before and after they used the AR learning environment to test their learning gain, and surveys to measure their acceptance of the technology, the cognitive load they experienced, and their attitude toward the use of AR to learn the mechanism for radical substitution. Analysis shows that the knowledge posttest scores were significantly higher than the pretest scores (p < 0.001), with a large effect size (r = 0.8). Student responses showed acceptance of the technology, experience of low extraneous cognitive load, and a positive attitude toward the use of AR to learn this reaction mechanism. These findings indicate that this AR learning environment can be used to teach the mechanism of radical substitution to tenth-grade students in introductory high school chemistry courses.publishe
Using Gesture and Speech to Control Surgical Lighting Systems: Mixed Methods Study
No full textBackground:
Surgical lighting systems (SLSs) provide optimal lighting conditions for operating room personnel. Current systems are mainly adjusted by hand; surgeons either accommodate the light themselves or communicate their requirements to an assistant to ensure optimal surgical conditions. This poses challenges to maintaining sterility, proper accessibility, and illumination and can lead to potential collision problems. Furthermore, the personnel operating the light may not have deep medical knowledge or equipment expertise.
Objective:
This paper introduces a touch-free interaction concept for controlling an SLS using speech and gestures.
Methods:
We used an iterative, user-centered design approach with participatory design sessions. This process involved conducting a literature review, several observations of actual surgical sites, and engaging stakeholders through interviews and focus groups. In addition, we carried out 2 user studies: one in a virtual reality setup and another in a living laboratory environment. Results:
Our findings indicate that our interaction concept is a viable alternative for controlling an SLS. Despite some technical limitations, surgical experts found the system intuitive and useful, recognizing the significant potential for touch-free lighting adjustments in the operating room. The combination of speech and gesture modalities was seen as helpful and even necessary, with some interactions better suited to one modality over the other. Offering both modalities for each interaction provided greater flexibility.
Conclusions:
Our findings suggest that our proposed touch-free interaction concept can enhance surgical conditions and has the potential to replace traditional adjustment.publishe
How strong is the rhythm of perception? : A registered replication of Hickok et al. (2015)
No full textOur ability to predict upcoming events is a fundamental component of human cognition. One way in which we do so is by exploiting temporal regularities in sensory signals: the ticking of a clock, falling of footsteps and the motion of waves each provide a structure that may facilitate anticipation. But how strong is the effect of rhythmic anticipation on perception? And to what degree do people vary in their ability to capitalize on these regularities? In 2015, Hickok et al. introduced a behavioural paradigm to assess how a rhythmic auditory stimulus affects perception of subsequent targets (Hickok G, Farahbod H, Saberi K. 2015 The rhythm of perception: entrainment to acoustic rhythms induces subsequent perceptual oscillation. Psychol. Sci. 26, 1006–1013. (doi:10.1177/0956797615576533)). They tested five listeners and found that perception (target detection accuracy) fluctuated rhythmically just like the sound rhythm. Here, we replicate the original finding, assess how likely the finding is to be observed for any individual, and quantify effect size in a large sample of adult listeners (n = 149). We introduce a model-based analysis approach that allows separate estimates of amplitude and phase information in target detection responses, and quantifies effect size for individual listeners. Together our results strongly support the presence of oscillatory influences on target detection accuracy, as well as substantial variability in the magnitude of this effect across listeners.publishe