540 research outputs found

    Sampling Piecewise Sinusoidal Signals With Finite Rate of Innovation Methods

    Get PDF

    Crystallographic orientation inhomogeneity and crystal splitting in biogenic calcite

    Get PDF
    The calcitic prismatic units forming the outer shell of the bivalve Pinctada margaritifera have been analysed using scanning electron microscopy–electron back-scatter diffraction, transmission electron microscopy and atomic force microscopy. In the initial stages of growth, the individual prismatic units are single crystals. Their crystalline orientation is not consistent but rather changes gradually during growth. The gradients in crystallographic orientation occur mainly in a direction parallel to the long axis of the prism, i.e. perpendicular to the shell surface and do not show preferential tilting along any of the calcite lattice axes. At a certain growth stage, gradients begin to spread and diverge, implying that the prismatic units split into several crystalline domains. In this way, a branched crystal, in which the ends of the branches are independent crystalline domains, is formed. At the nanometre scale, the material is composed of slightly misoriented domains, which are separated by planes approximately perpendicular to the c-axis. Orientational gradients and splitting processes are described in biocrystals for the first time and are undoubtedly related to the high content of intracrystalline organic molecules, although the way in which these act to induce the observed crystalline patterns is a matter of future research

    HSP: Bystander Antigen in Atopic Diseases?

    Get PDF
    Over the last years insight in the complex interactions between innate and adaptive immunity in the regulation of an inflammatory response has increased enormously. This has revived the interest in stress proteins; proteins that are expressed during cell stress. As these proteins can attract and trigger an immunological response they can act as important mediators in this interaction. In this respect, of special interest are proteins that may act as modulators of both innate and adaptive immunity. Heat shock proteins (HSPs) are stress proteins that have these, and more, characteristics. More than two decades of studies on HSPs has revealed that they are part of intrinsic, “natural” mechanisms that steer inflammation. This has provoked comprehensive explorations of the role of HSPs in various human inflammatory diseases. Most studies have focused on classical autoimmune diseases. This has led to the development of clinical studies with HSPs that have shown promise in Phase II/III clinical trials. Remarkably, only very little is yet known of the role of HSPs in atopic diseases. In allergic disease a number of studies have investigated the possibility that allergen-specific regulatory T cell (Treg) function is defective in individuals with allergic diseases. This raises the question whether methods can be identified to improve the Treg repertoire. Studies from other inflammatory diseases have suggested HSPs may have such a beneficial effect on the T cell repertoire. Based on the immune mechanisms of atopic diseases, in this review we will argue that, as in other human inflammatory conditions, understanding immunity to HSPs is likely also relevant for atopic diseases. Specifically, we will discuss why certain HSPs such as HSP60 connect the immune response to environmental antigens with regulation of the inflammatory response. Thus they provide a molecular link that may eventually even help to better understand the immune pathological basis of the hygiene hypothesis

    In the name of democracy : the value of democracy explains leniency towards wrongdoings as a function of group political organization

    Get PDF
    According to the "democracy-as-value" hypothesis, democracy has become an ideological belief system providing social value to democratic individuals, groups and institutions, granting legitimacy to their actions (even if dishonest or violent), and protecting them from consecutive punishments. The present research investigates the extent to which this legitimizing process is based on the individual endorsement of democratic principles. Across four experiments, following the misdeed of a (few) group member(s), respondents who valued democratic group organization and democracy in general expressed more lenient retributive justice judgments towards democratic (as compared with nondemocratic) offender groups. These findings shed light on the ways in which democratic ideology infuses justice judgments

    Collective punishment depends on collective responsibility and political organization of the target group

    Get PDF
    What factors determine the willingness to inflict collective punishment upon a group for a misdeed committed by individual group members? This research investigates the effect of collective responsibility shared among group members and the moderating effect of the group's political organization (democratic vs. nondemocratic). Hypothesizing that moral accountability should be greater for democratic offender groups compared to nondemocratic groups, five experiments showed that the positive effect of collective responsibility on support for collective punishment (Experiment 1) was stronger for democratic groups than for nondemocratic groups (Experiments 2-5). A sixth experiment revealed that the moral and social value ascribed to democracy led to higher expectations towards democratic groups, resulting in negative perceptions of the democratic offender group and ultimately in increased collective punishment. The results are discussed in terms of defense strategies of democratic values

    The Sensitivity and Psychometric Properties of a Brief Computer-Based Cognitive Screening Battery in a Depression Clinic

    Get PDF
    At present, there is poor accuracy in assessing cognitive and vegetative symptoms in depression using clinician or self-rated measures, suggesting the need for development of standardized tasks to assess these functions. The current study assessed the psychometric properties and diagnostic specificity of a brief neuropsychological screening battery designed to assess core signs of depression; psychomotor retardation, attention and executive functioning difficulties, and impaired emotion perception within an outpatient psychiatry setting. Three hundred eighty-four patients with mood disorders and 77 healthy volunteers participated. A large percentage of patients met diagnostic criteria for Major Depressive Disorder alone (49%) or with another comorbid psychiatric disorder (24%). A brief, 25-min battery of computer-based tests was administered to control participants and patients measuring the constructs of inhibitory control, attention, visual perception, and both executive and visual processing speed. The patient groups performed significantly worse than the control group regardless of diagnosis on visual perception and attention accuracy and processing speed factors. Surprisingly, the anxiety disorder group performed better than several other psychiatric disorder groups in inhibitory control accuracy. Developing valid and reliable measures of cognitive signs in mood disorders creates excellent opportunities for tracking cognitive status prior to initiation of treatment, and allows for reliable retest following treatment

    Prerequisites for cytokine measurements in clinical trials with multiplex immunoassays

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Growing knowledge about cellular interactions in the immune system, including the central role of cytokine networks, has lead to new treatments using monoclonal antibodies that block specific components of the immune system. Systemic cytokine concentrations can serve as surrogate outcome parameters of these interventions to study inflammatory pathways operative in patients <it>in vivo</it>. This is now possible due to novel technologies such as multiplex immunoassays (MIA) that allows detection of multiple cytokines in a single sample. However, apparently trivial underappreciated processes, (sample handling and storage, interference of endogenous plasma proteins) can greatly impact the reliability and reproducibility of cytokine detection.</p> <p>Therefore we set out to investigate several processes that might impact cytokine profiles such as blood collecting tubes, duration of storage, and number of freeze thawing cycles.</p> <p>Results</p> <p>Since under physiological conditions cytokine concentrations normally are low or undetectable we spiked cytokines in the various plasma and serum samples. Overall recoveries ranged between 80-120%. Long time storage showed cytokines are stable for a period up to 2 years of storage at -80°C. After 4 years several cytokines (IL-1α, IL-1β, IL-10, IL-15 and CXCL8) degraded up to 75% or less of baseline values. Furthermore we show that only 2 out of 15 cytokines remained stable after several freeze-thawing cycles. We also demonstrate implementation of an internal control for multiplex cytokine immunoassays.</p> <p>Conclusion</p> <p>All together we show parameters which are essential for measurement of cytokines in the context of clinical trials.</p

    Collective apologies moderate the effects of justice concerns on support for collective punishment

    Get PDF
    Following an offense, various justice concerns arise, and people might support the punishment of the offender’s entire group to restore a sense of justice (even if the other group members are innocent). We hypothesized that support for collective punishment might increase along one’s justice concerns, and that such effect can be hindered by the group’s collective apologies. In three studies, third-party observers were presented with various cases of aggression and we measured (Study 1) or manipulated (Studies 2 and 3) their justice concerns. In all studies, the presence (vs. absence) of collective apologies was additionally manipulated. The results confirmed our hypothesis thereby increasing our knowledge of both the determinants of collective punishment and the potential effects of collective apologies.This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 703401Social decision makin

    Sampling Piecewise Sinusoidal Signals With Finite Rate of Innovation Methods

    Full text link
    corecore