235 research outputs found

    Propulsion Mechanisms for Leidenfrost Solids on Ratchets

    Get PDF
    We propose a model for the propulsion of Leidenfrost solids on ratchets based on viscous drag due to the flow of evaporating vapor. The model assumes pressure-driven flow described by the Navier-Stokes equations and is mainly studied in lubrication approximation. A scaling expression is derived for the dependence of the propulsive force on geometric parameters of the ratchet surface and properties of the sublimating solid. We show that the model results as well as the scaling law compare favorably with experiments and are able to reproduce the experimentally observed scaling with the size of the solid

    Combined Effects of Knowledge About Others' Opinions and Anticipation of Group Discussion on Confirmatory Information Search

    Get PDF
    There is conclusive evidence that information search processes are typically biased in favor of the information seeker’s own opinion (confirmation bias). Less is known about how knowledge about others’ opinions affects this confirmatory information search. In the present study, the authors manipulated feedback about others’ opinions and anticipation of group interaction. As predicted, the effect of knowledge about others’ opinions on confirmatory information search depended on whether participants anticipated interacting with these others. Specifically, minority members anticipating a group discussion exhibited a particularly strong confirmation bias, whereas minority members who did not anticipate a discussion predominantly sought information opposing their opinion. For participants not anticipating group interaction, confidence about the correctness of one’s decision mediated the impact of knowledge about others’ opinions on confirmatory information search. Results are discussed with regard to the debiasing effect of preference heterogeneity on confirmatory information search in groups

    Biased Information Search in Homogeneous Groups: Confidence as a Moderator for the Effect of Anticipated Task Requirements

    Get PDF
    When searching for information, groups that are homogeneous regarding their members’ prediscussion decision preferences show a strong bias for information that supports rather than conflicts with the prevailing opinion (confirmation bias). The present research examined whether homogeneous groups blindly search for information confirming their beliefs irrespective of the anticipated task or whether they are sensitive to the usefulness of new information for this forthcoming task. Results of three experiments show that task sensitivity depends on the groups’ confidence in the correctness of their decision: Moderately confident groups displayed a strong confirmation bias when they anticipated having to give reasons for their decision but showed a balanced information search or even a disconfirmation bias (i.e., predominately seeking conflicting information) when they anticipated having to refute unterarguments. In contrast, highly confident groups demonstrated a strong confirmation bias independent of the anticipated task requirements

    Beyond group-level explanations for the failure of groups to solve hidden profiles: The individual preference effect revisited

    Get PDF
    The individual preference effect supplements the predominant group-level explanations for the failure of groups to solve hidden profiles. Even in the absence of dysfunctional group-level processes, group members tend to stick to their suboptimal initial decision preferences due to preference-consistent evaluation of information. However, previous experiments demonstrating this effect retained two group-level processes, namely (a) social validation of information supporting the group members’ initial preferences and (b) presentation of the additional information in a discussion format. Therefore, it was unclear whether the individual preference effect depends on the co-occurrence of these group-level processes. Here, we report two experiments demonstrating that the individual preference effect is indeed an individual-level phenomenon. Moreover, by a comparison to real interacting groups, we can show that even when all relevant information is exchanged and when no coordination losses occur, almost half of all groups would fail to solve hidden profiles due to the individual preference effect

    Social validation in group decision making: differential effects on the decisional impact of preference-consistent and preference-inconsistent information

    Full text link
    "Shared information has a stronger impact on group decisions than unshared information. A prominent explanation for this phenomenon is that shared information can be socially validated during group discussion and, hence, is perceived as more accurate and relevant than unshared information. In the present study we argue that this explanation only holds for preference-inconsistent information (i.e., information contradicting the group members’ initial preferences) but not for preference-consistent information. In Experiments 1 and 2 participants studied the protocol of a fictitious group discussion. In this protocol, we manipulated which types of information were socially validated. As predicted, social validation increased the decisional impact of preference-inconsistent but not preference-consistent information. In both experiments the effect of social validation was mediated by the perceived quality of information. Experiment 3 replicated the results of the first two experiments in an interactive setting in which two confederates discussed a decision case face-to-face with one participant." [author's abstract

    Dapper-1 is essential for Wnt5a induced cardiomyocyte hypertrophy by regulating the Wnt/PCP pathway

    Get PDF
    AbstractThe Wnt signaling pathway was identified as crucial mediator of cardiomyocyte hypertrophy. In this study we found that activation of non-canonical Wnt signaling by Wnt5a stimulates protein synthesis and enlargement of cardiomyocyte surface area. These hypertrophic features were inhibited in Dapper-1 (Dpr1) depleted cells. On the molecular level, we observed inhibition of the non-canonical Wnt/planar-cell-polarity (PCP) pathway denoted by reduction of c-jun-n-terminal-kinase (JNK) phosphorylation. Upstream of JNK, increased protein levels of the Wnt/PCP trans-membrane receptor van-Gogh-like-2 (Vangl2) were observed along with an enrichment of Vangl2 in perinuclear located vesicles. The findings suggest that Dpr1 is essential for execution of the Wnt/PCP pathway and regulation of the Vangl2/JNK axis. Depletion of Dpr1 inhibits non-canonical Wnt signaling induced cardiomyocyte hypertrophy by blocking Wnt/PCP signaling

    Auxiliary Subunits Control Function and Subcellular Distribution of AMPA Receptor Complexes in NG2 Glia of the Developing Hippocampus

    Get PDF
    Synaptic and axonal glutamatergic signaling to NG2 glia in white matter is critical for the cells’ differentiation and activity dependent myelination. However, in gray matter the impact of neuron-to-NG2 glia signaling is still elusive, because most of these cells keep their non-myelinating phenotype throughout live. Early in postnatal development, hippocampal NG2 glia express AMPA receptors with a significant Ca2+ permeability allowing for plasticity of the neuron-glia synapses, but whether this property changes by adulthood is not known. Moreover, it is unclear whether NG2 glia express auxiliary transmembrane AMPA receptor related proteins (TARPs), which modify AMPA receptor properties, including their Ca2+ permeability. Through combined molecular and functional analyses, here we show that hippocampal NG2 glia abundantly express TARPs γ4, γ7, and γ8 as well as cornichon (CNIH)-2. TARP γ8 undergoes profound downregulation during development. Receptors of adult NG2 glia showed an increased sensitivity to blockers of Ca2+ permeable AMPA receptors, but this increase mainly concerned receptors located close to the soma. Evoked synaptic currents of NG2 glia were also sensitive to blockers of Ca2+ permeable AMPA receptors. The presence of AMPA receptors with varying Ca2+ permeability during postnatal maturation may be important for the cells’ ability to sense and respond to local glutamatergic activity and for regulating process motility, differentiation, and proliferation

    AARC Blueprint Architecture 2019

    Get PDF
    The AARC Blueprint Architecture (BPA) provides a set of building blocks for software architects and technical decision makers who are designing and implementing access management solutions for international research collaborations. This document describes the evolution of the AARC Blueprint Architecture, starting with a summary of the changes since AARC-BPA-2017. The current iteration of the BPA focuses on the interoperability aspects, to address an increasing number of use cases from research communities requiring access to federated resources offered by different research and e-Infrastructures. Hence the introduction of the Community AAI, which streamlines researchers’ access to services. These typically include services offered to members of a specific community, as well as infrastructure services that may be shared with other communities. Users can authenticate to the Community AAI primarily via institutional credentials from national identity federations in eduGAIN, but, if permitted by the community, can also use other Identity Providers

    Guidelines for expressing group membership and role information (AARC-G069)

    Get PDF
    Information about the groups a user is a member of is commonly used by relying parties in order to authorise user access to protected resources. This document provides guidelines for expressing group membership and role information across AARC BPA-compliant AAI services. Specifically, it defines a URN namespace for expressing this information using common identity federation protocols, namely SAML and OpenID Connect/OAuth2

    Liquid Wells as Self-Healing, Functional Analogues to Solid Vessels

    Get PDF
    Liquids are traditionally handled and stored in solid vessels. Solid walls are not functional, adaptive, or self-repairing, and are difficult to remove and re-form. Liquid walls can overcome these limitations, but cannot form free-standing 3D walls. Herein, a liquid analogue of a well, termed a “liquid well” is introduced. Water tethered to a surface with hydrophobic–hydrophilic core–shell patterns forms stable liquid walls capable of containing another immiscible fluid, similar to fluid confinement by solid walls. Liquid wells with different liquids, volumes, and shapes are prepared and investigated by confocal and Raman microscopy. The confinement of various low-surface-tension liquids (LSTLs) on surfaces by liquid wells can compete with or be complementary to existing confinement strategies using perfluorinated surfaces, for example, in terms of the shape and height of the confined LSTLs. Liquid wells show unique properties arising from their liquid aggregate state: they are self-healing, dynamic, and functional, that is, not restricted to a passive confining role. Water walls can be easily removed and re-formed, making them interesting as sacrificial templates. This is demonstrated in a process termed water-templated polymerization (WTP). Numerical phase-field model simulations are performed to scrutinize the conditions required for the formation of stable liquid wells
    • …
    corecore