584 research outputs found

    Helminths in the hygiene hypothesis:Sooner or later?

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    There is increasing recognition that exposures to infectious agents evoke fundamental effects on the development and behaviour of the immune system. Moreover, where infections (especially parasitic infections) have declined, immune responses appear to be increasingly prone to hyperactivity. For example, epidemiological studies of parasite-endemic areas indicate that prenatal or early-life experience of infections can imprint an individual's immunological reactivity. However, the ability of helminths to dampen pathology in established inflammatory diseases implies that they can have therapeutic effects even if the immune system has developed in a low-infection setting. With recent investigations of how parasites are able to modulate host immune pathology at the level of individual parasite molecules and host cell populations, we are now able to dissect the nature of the host–parasite interaction at both the initiation and recall phases of the immune response. Thus the question remains – is the influence of parasites on immunity one that acts primarily in early life, and at initiation of the immune response, or in adulthood and when recall responses occur? In short, parasite immunosuppression – sooner or later

    An Exploration of how Individuals Affected by Social Anxiety Experience Relationships with Others.

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    Social anxiety causes disruption to relational functioning leading some researchers to describe it as an interpersonal problem (Alden & Taylor, 2004, 2010). However, research exploring interpersonal aspects of social anxiety is strikingly limited. Furthermore the research that has been conducted is predominantly informed by a positivist and quantitative framework. The way in which socially anxious individuals ‘experience’ interpersonal relationships with others is therefore poorly understood. The present study addresses this gap in the literature by adopting a phenomenological approach. The aim of this research is to uncover the understandings, explanations and perceptions socially anxious individuals have of interpersonal relationships. Six socially anxious individuals were recruited from UK based social anxiety support groups and interviewed about important relationships in their lives. The data generated was subjected to Interpretative Phenomenological Analysis leading to four superordinate themes: ‘The Desire for Intimacy’, ‘Interpersonal Barriers’, ‘Interpersonal Adaptations’ and ‘Intimacy’. These superordinate themes, along with their corresponding subordinate themes, capture the rich phenomenological world of the participants and provide insight into the way socially anxious individuals experience interpersonal relationships with others. These findings are discussed in the context of the existing literature. Implications for clinical practice and further research are suggested

    Orthogonal Arrays of Strength Three from Regular 3-Wise Balanced Designs

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    The construction given in Kreher, J Combin Des 4 (1996) 67 is extended to obtain new infinite families of orthogonal arrays of strength 3. Regular 3-wise balanced designs play a central role in this construction

    Setting things straight: a comparison of measures of saccade trajectory deviation

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    In eye movements, saccade trajectory deviation has often been used as a physiological operationalization of visual attention, distraction, or the visual system’s prioritization of different sources of information. However, there are many ways to measure saccade trajectories and to quantify their deviation. This may lead to noncomparable results and poses the problem of choosing a method that will maximize statistical power. Using data from existing studies and from our own experiments, we used principal components analysis to carry out a systematic quantification of the relationships among eight different measures of saccade trajectory deviation and their power to detect the effects of experimental manipulations, as measured by standardized effect size. We concluded that (1) the saccade deviation measure is a good default measure of saccade trajectory deviation, because it is somewhat correlated with all other measures and shows relatively high effect sizes for two well-known experimental effects; (2) more generally, measures made relative to the position of the saccade target are more powerful; and (3) measures of deviation based on the early part of the saccade are made more stable when they are based on data from an eyetracker with a high sampling rate. Our recommendations may be of use to future eye movement researchers seeking to optimize the designs of their studies

    Effect of organic amendments on Meloidogyne arenaria population in potted soil.

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    Organic admendments (OA) were evaluated for their effectiveness in suppressing Meloidogyne arenaria populations in 2 greenhouse experiments in naturally infeste soil

    The programming of sequences of saccades

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    Saccadic eye movements move the high-resolution fovea to point at regions of interest. Saccades can only be generated serially (i.e., one at a time). However, what remains unclear is the extent to which saccades are programmed in parallel (i.e., a series of such moments can be planned together) and how far ahead such planning occurs. In the current experiment, we investigate this issue with a saccade contingent preview paradigm. Participants were asked to execute saccadic eye movements in response to seven small circles presented on a screen. The extent to which participants were given prior information about target locations was varied on a trial-by-trial basis: participants were aware of the location of the next target only, the next three, five, or all seven targets. The addition of new targets to the display was made during the saccade to the next target in the sequence. The overall time taken to complete the sequence was decreased as more targets were available up to all seven targets. This was a result of a reduction in the number of saccades being executed and a reduction in their saccade latencies. Surprisingly, these results suggest that, when faced with a demand to saccade to a large number of target locations, saccade preparation about all target locations is carried out in paralle

    Cultivation of Heligmosomoides polygyrus:An immunomodulatory nematode parasite and its secreted products

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    Heligmosomoides polygyrus (formerly known as Nematospiroides dubius, and also referred to by some as H. bakeri) is a gastrointestinal helminth that employs multiple immunomodulatory mechanisms to establish chronic infection in mice and closely resembles prevalent human helminth infections. H. polygyrus has been studied extensively in the field of helminth-derived immune regulation and has been found to potently suppress experimental models of allergy and autoimmunity (both with active infection and isolated secreted products). The protocol described in this paper outlines management of the H. polygyrus life cycle for consistent production of L3 larvae, recovery of adult parasites, and collection of their excretory-secretory products (HES)

    Protein hydrolysates from boarfish (Capros aper) and Atlantic salmon (Salmo salar) skin gelatin improve metabolic control in genetically obese diabetic (ob/ob) mice

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    There is increasing interest in dietary protein for management of Type 2 diabetes mellitus (T2DM) and obesity. The effects of twice-daily oral administration of a salmon skin gelatin hydrolysate (SSGH, 50 mg/kg), boarfish protein hydrolysate (BPH, (50 mg/kg), metformin (200 mg/kg), or saline control, were investigated in ob/ob mice. Non-fasting blood glucose was significantly reduced with SSGH (p < 0.01), BPH (p < 0.001) and metformin (p < 0.001), which were reflected in reductions in glycated haemoglobin (HbA1c) (p < 0.001, p < 0.01 and p < 0.01, respectively). Responses to oral and intraperitoneal glucose tolerance were improved (p < 0.05–0.01), as well as circulating plasma lipid profiles (p < 0.05–0.001). Chronic BPH treatment increased circulating plasma insulin (p < 0.01), whereas SSGH improved insulin sensitivity (p < 0.05), versus respective controls. All treatments significantly reduced energy intake (p < 0.05–0.001) versus (ob/ob) controls, without affecting overall bodyweight. These findings suggest that fish hydrolysates mediate potent anti-diabetic actions similar to metformin and might be suitable for the management and prevention of T2DM

    Temporal Expression of Bacterial Proteins Instructs Host CD4 T Cell Expansion and Th17 Development

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    Pathogens can substantially alter gene expression within an infected host depending on metabolic or virulence requirements in different tissues, however, the effect of these alterations on host immunity are unclear. Here we visualized multiple CD4 T cell responses to temporally expressed proteins in Salmonella-infected mice. Flagellin-specific CD4 T cells expanded and contracted early, differentiated into Th1 and Th17 lineages, and were enriched in mucosal tissues after oral infection. In contrast, CD4 T cells responding to Salmonella Type-III Secretion System (TTSS) effectors steadily accumulated until bacterial clearance was achieved, primarily differentiated into Th1 cells, and were predominantly detected in systemic tissues. Thus, pathogen regulation of antigen expression plays a major role in orchestrating the expansion, differentiation, and location of antigen-specific CD4 T cells in vivo
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