University of Konstanz
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ARTHUR: authoring human–robot collaboration processes with augmented reality using hybrid user interfaces
No full textWhile augmented reality shows promise for supporting human–robot collaboration, creating such interactive systems still poses great challenges. Addressing this, we introduce ARTHUR, an open-source authoring tool for augmented reality-supported human–robot collaboration. We thereby propose to combine desktop interfaces and touchscreen devices for effective authoring with head-mounted displays for testing and in-situ refinements. ARTHUR supports 20 types of multi-modal feedback to convey robot, task, and system state, 10 actions that enable the user to control the robot and system, and 18 conditions for feedback customization and triggering of actions. By combining these elements, users can create interaction spaces, controls, and information visualizations in augmented reality for collaboration with robot arms. To demonstrate the general applicability of ARTHUR for human–robot collaboration scenarios, we replicate representative examples from prior work. Further, in an evaluation with five domain-savvy participants, we reflect on the usefulness of our hybrid user interface approach and the supported functionality, highlighting its potential and directions for future work.publishe
An efficacious remedy for status inequality? : Indigenous policies in Norway and Sweden
No full textMost states publicly support the recognition of Indigenous rights. Nevertheless, their domestic policies to address Indigenous rights issues vary considerably across countries. So far, research has not committed itself to investigating the consequences of different Indigenous policies on the peoples concerned and their social status. Do policy contexts that accommodate Indigenous rights firmly contribute to status equality between Indigenous people and the ethnic majority? I study this question in the case of Norway and Sweden. These countries host one Indigenous people – the Sámi – but pursue diverging Indigenous policies. Using new survey data, I show that, despite the absence of material inequalities, there is a clear gap in the social status perceptions between Indigenous and majority respondents in Sweden. In Norway, I do not find that Sámi’s perception of their social position is lower than the majority's. The results suggest that the Swedish policies governing the recognition of Sámi rights are less effective in resolving unequal status perceptions.publishe
Stress correlations and stress memory kernels in viscoelastic fluids
No full textWe discuss the spatio-temporal correlations of stress fluctuations in viscoelastic fluids, including colloidal dispersions, polymer melts and glass-forming liquids. First, we relate the tensor of stress auto-correlation functions to its corresponding tensor of generalized Onsager transport kernels. The relation is valid at finite wavelengths and frequencies, and serves as basis for continuum mechanics approximations, where it leads to the viscosities in a fluid and to the elastic constants in a solid. Second, we consider the long wavelength limit and re-derive the far-field power-law stress correlations in fluid states. Two theoretical approaches are studied and give equivalent results. One approach is based on the familiar Zwanzig–Mori decomposition of the stress tensor, while the other approach decomposes the stress into a deterministic one due to the history of prior internal flow and a contribution due to “stress noise” that persists even if internal flow is suppressed. The general results are used to predict the distance dependence of the shear stress correlation function both for 2D and 3D systems. An encouraging agreement of these predictions with simulation data on 2D and 3D binary hard-sphere mixtures is observed.publishe
The innexin 7 gap junction protein contributes to synchronized activity in the Drosophila antennal lobe and regulates olfactory function
No full textIn the mammalian olfactory bulb (OB), gap junctions coordinate synchronous activity among mitral and tufted cells to process olfactory information. In insects, gap junctions are also present in the antennal lobe (AL), a structure homologous to the mammalian OB. The invertebrate gap junction protein ShakB contributes to electrical synapses between AL projection neurons (PNs) in Drosophila . Other gap junction proteins, including innexin 7 (Inx7), are also expressed in the Drosophila AL, but little is known about their contribution to intercellular communication during olfactory information processing. In this study, we report spontaneous calcium transients in PNs grown in cell culture that are highly synchronous when these neurons are physically connected. RNAi-mediated knockdown of Inx7 in cultured PNs blocks calcium transient neuronal synchronization. In vivo , downregulation of Inx7 in the AL impairs both vinegar-induced electrophysiological calcium responses and behavioral responses to this appetitive stimulus. These results demonstrate that Inx7-encoded gap junctions functionally coordinate PN activity and modulate olfactory information processing in the adult Drosophila AL.publishe
Rückkehr zum Dialog : Public Anthropology und die Untersuchung von repugnant others
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Individual preferences for certain types of spirals and the possible role of creativity
No full textThis study explores the appeal of different types of spirals, commonly found in nature, architecture, and art. The first experiment investigated aesthetic appreciation of Archimedean, logarithmic, and golden spirals, considering factors such as size and the number of turns. As a result, three groups of individuals were identified: those who favored golden spirals, those who preferred Archimedean spirals, and a group that liked logarithmic spirals and similar ones. Interestingly, personality traits showed no clear relation with these preferences. In the first part of a second experiment, the participants were not only asked to choose between different types of spirals, but also to justify their choice by providing reasons. The results indicate that the preferences often stem from the spirals’ features as well as from personal associations, confirming that aesthetic judgments are influenced by both objective and subjective factors. However, results also suggested that the preference for certain types of spirals is related to creativity. This hypothesis was tested in the second part of the second experiment in which participants generated associations to the spirals. The analysis of the frequency and originality of the associations revealed that individuals who prefer the golden spiral to the Archimedean spiral tend to be more creative. Overall, the study highlights the complexity of aesthetic preferences and the potential role of both objective features and subjective associations in shaping our responses to spirals.publishe
Enhanced Detection of Age‐Related and Cognitive Declines Using Automated Hippocampal‐To‐Ventricle Ratio in Alzheimer's Patients
No full textThe hippocampal‐to‐ventricle ratio (HVR) is a biomarker of medial temporal atrophy, particularly useful in the assessment of neurodegeneration in diseases such as Alzheimer's disease (AD). To minimize subjectivity and inter‐rater variability, an automated, accurate, precise, and reliable segmentation technique for the hippocampus (HC) and surrounding cerebro‐spinal fluid (CSF) filled spaces—such as the temporal horns of the lateral ventricles—is essential. We trained and evaluated three automated methods for the segmentation of both HC and CSF (Multi‐Atlas Label Fusion (MALF), Nonlinear Patch‐Based Segmentation (NLPB), and a Convolutional Neural Network (CNN)). We then evaluated these methods, including the widely used FreeSurfer technique, using baseline T1w MRIs of 1641 participants from the AD Neuroimaging Initiative study with various degree of atrophy associated with their cognitive status on the spectrum from cognitively healthy to clinically probable AD. Our gold standard consisted in manual segmentation of HC and CSF from 80 cognitively healthy individuals. We calculated HC volumes and HVR and compared all methods in terms of segmentation reliability, similarity across methods, sensitivity in detecting between‐group differences and associations with age, scores of the learning subtest of the Rey Auditory Verbal Learning Test (RAVLT) and the Alzheimer's Disease Assessment Scale 13 (ADAS13) scores. Cross validation demonstrated that the CNN method yielded more accurate HC and CSF segmentations when compared to MALF and NLPB, demonstrating higher volumetric overlap (Dice Kappa = 0.94) and correlation (rho = 0.99) with the manual labels. It was also the most reliable method in clinical data application, showing minimal failures. Our comparisons yielded high correlations between FreeSurfer, CNN and NLPB volumetric values. HVR yielded higher control:AD effect sizes than HC volumes among all segmentation methods, reinforcing the significance of HVR in clinical distinction. The positive association with age was significantly stronger for HVR compared to HC volumes on all methods except FreeSurfer. Memory associations with HC volumes or HVR were only significant for individuals with mild cognitive impairment. Finally, the HC volumes and HVR showed comparable negative associations with ADAS13, particularly in the mild cognitive impairment cohort. This study provides an evaluation of automated segmentation methods centered to estimate HVR, emphasizing the superior performance of a CNN‐based algorithm. The findings underscore the pivotal role of accurate segmentation in HVR calculations for precise clinical applications, contributing valuable insights into medial temporal lobe atrophy in neurodegenerative disorders, especially AD.publishe
On the integration of collective motion and temporal synchrony in animal collectives
No full textAnimal groups come in diverse forms—from fish schools swimming in unison to crickets chirping in synchrony. Although these behaviors may seem considerably different to one another, they share a common mathematical core, and can therefore be considered in a unified manner. We discuss the commonalities and differences by synthesizing existing literature from both fields, encompassing both theoretical and empirical advances. We emphasize the crucial role of mixing, induced by individual movements, as a main differentiating factor. Along the way, we propose promising future directions for achieving a more comprehensive understanding of self-organized collective behavior.publishe
Are poor people poorly heard?
No full textA growing body of literature shows that the preferences of poorer groups in society are less well represented than the preferences of the rich. This paper scrutinises one possible explanation of inequality in representation: that politicians hold biased perceptions of what citizens want. We conducted surveys with citizens and politicians in four countries: Belgium, Switzerland, Canada and Germany. Citizens provided their preferences regarding concrete policy proposals, and then politicians estimated these preferences. Comparing politicians’ estimates with the actual preferences of different social groups, the paper shows that politicians’ perceptions are closer to the preferences of the richer than to those of poorer people for issues that matter most for economic inequality: socio‐economic issues. Further, we find that especially right‐wing politicians tend to think about the preferences of richer societal groups when estimating the preferences of their partisan electorates on socio‐economic matters.publishe