15 resultados para 1274
Resumo:
OBJECTIVE: Impaired flow-mediated dilation (FMD) occurs in disease states associated with atherosclerosis, including SLE. The primary hemodynamic determinant of FMD is wall shear stress, which is critically dependent on the forearm microcirculation. We explored the relationship between FMD, diastolic shear stress (DSS), and the forearm microcirculation in 32 patients with SLE and 19 controls. METHODS AND RESULTS: DSS was calculated using (mean diastolic velocity x 8 x blood viscosity)/baseline brachial artery diameter. Doppler velocity envelopes from the first 15 seconds of reactive hyperemia were analyzed for resistive index (RI), and interrogated in the frequency domain to assess forearm microvascular hemodynamics. FMD was significantly impaired in SLE patients (median, 2.4%; range, -2.1% to 10.7% versus median 5.8%; range, 1.9% to 14%; P
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The effect of water depth on the performance of a small surging wave energy converter (WEC) is investigated analytically, numerically and experimentally. It is shown that although the average annual incident wave power is significantly reduced by water depth, a large proportion of this reduction is due to the dissipation of highly energetic, but largely unexploitable seas. It is also shown that the power capture is related more closely to incident wave force than incident wave power. Experimental results demonstrate that both the surge wave force and power capture of a flap-type WEC increase in shallow water.
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The modern world is replete with ethical challenges of Orwellian proportions. The violation of human rights and misrecognition of identities are two of the most pressing examples. In this paper, the ethical theories of Habermas and Honneth are aligned as a way of addressing these specific challenges within social work. It is suggested that these theories are complementary, mutually rectifying and concordant at the meta-ethical level of analysis. The alignment is also justified, pargmatically, through the construction of three hypothetical vignettes demonstrating different kinds of practice dilemmas. The need for egalitarian communication and the imperative to recognise human identity in all its dimensions subsequently emerge as the two foundation stones for ethical deliberation in social work.
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Life-history theory suggests that offspring desertion can be an adaptive reproductive strategy, in which parents forgo the costly care of an unprofitable current brood to save resources for future reproduction. In the burying beetle, Nicrophorus vespilloides, parents commonly abandon their offspring to the care of others, resulting in female-only care, male-only care, brood parasitism, and the care of offspring sired by satellite males. Furthermore, when there is biparental care, males routinely desert the brood before larval development is complete, leaving females behind to tend their young. We attempted to understand these patterns of offspring desertion by using laboratory experiments to compare the fitness costs associated with parental care for each sex and the residual reproductive value of the 2 sexes. We also tested whether current brood size and residual reproductive value together predicted the incidence of brood desertion. We found that males and females each sustained fecundity costs as a consequence of caring for larvae and that these costs were of comparable magnitude. Nevertheless, males had greater residual reproductive value than females and were more likely than females to desert experimental broods. Our results can explain why males desert the brood earlier than females in nature and why female-only care is more common than male-only care. They also suggest that the tipping point from brood parasitism or satellite male behavior to communal breeding (and vice versa) depends on the value of the current brood relative to residual reproductive value.
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Abstract Objective: To report trends in underweight, overweight and obesity in 12–15-year-old adolescents and examine changes in dieting behaviour, which have been less well documented. Design: Comparison of two independent representative cross-sectional surveys. Setting: Northern Ireland. Subjects: Weight and height were objectively measured in 1324 boys and 1160 girls in 1996 and 1274 boys and 1374 girls in 2007. Participants reported whether they were following any particular diet including a self-proposed or prescribed weight-reduction diet. Results: Overweight and obesity increased in girls from 15% to 23% and 2% to 6%, respectively. Increases were more modest in boys with overweight increasing from 13% to 18% and obesity from 3% to 6%. The proportion of underweight adolescents decreased from 9% to 6% in girls and 8% to 5% in boys. Evidence of social disparity was observed in girls from a manual socio-economic background, with overweight/obesity prevalence rates increasing from 21% to 36% compared with 15% to 26% in girls from a non-manual background. Despite these trends fewer adolescents, in particular girls, reported following weight-reduction diets (14% of overweight/obese girls in 2007 v. 21% in 1996; 8% of boys in 2007 v. 13% in 1996). Of these girls, the proportion from a manual background following weight-reduction diets decreased from 25% to 11%. Conclusions: Overweight and obesity are continuing to increase in adolescents despite government and media awareness strategies. There also appears to be reduced dieting behaviour, despite increasing body weight, particularly in girls from manual socio-economic backgrounds.
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Objectives This study describes the in-situ gelling of econazole nitrate containing thermosensitive polymers composed of poloxamer 407 and 188 as a novel treatment platform for vaginal candidiasis.
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CTLA-4 is a crucial immune regulator that mediates both negative co-stimulation signals to T cells, and regulatory T (Treg) cell extrinsic control of effector responses. Here we present evidence supporting a novel mechanism for this extrinsic suppression, executed by the alternatively spliced soluble CTLA-4 isoform (sCTLA-4). Analyses of human T cells in vitro show that sCTLA-4 secretion can be increased during responses, and has potent inhibitory properties, since isoform-specific blockade of its activity significantly increased antigen-driven proliferation and cytokine (interferon-?, IL-17) secretion. Treg cells were demonstrated to be a prominent source of sCTLA-4, which contributed to suppression in vitro when their numbers were limiting. The soluble isoform was also produced by, and inhibited, murine T cells responding to antigen in vitro, and blockade of its activity in vivo protected against metastatic spread of melanoma in mice. We conclude that sCTLA-4 is an important immune regulator, responsible for at least some of the inhibitory effects previously ascribed to the membrane-bound isoform. These results suggest that the immune system exploits the different CTLA-4 isoforms for either intrinsic or extrinsic regulation of T-cell activity.
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The organizational and architectural configuration of white matter pathways connecting brain regions has ramifications for all facets of the human condition, including manifestations of incipient neurodegeneration. Although diffusion tensor imaging (DTI) has been used extensively to visualize white matter connectivity, due to the widespread presence of crossing fibres, the lateral projections of the corpus callosum are not normally detected using this methodology. Detailed knowledge of the transcallosal connectivity of the human cortical motor network has therefore remained elusive. We employed constrained spherical deconvolution (CSD) tractography - an approach that is much less susceptible to the influence of crossing fibres, in order to derive complete in-vivo characterizations of white matter pathways connecting specific motor cortical regions to their counterparts and other loci in the opposite hemisphere. The revealed patterns of connectivity closely resemble those derived from anatomical tracing in primates. It was established that dorsal premotor cortex (PMd) and supplementary motor area (SMA) have extensive interhemispheric connectivity - exhibiting both dense homologous projections, and widespread structural relations with every other region in the contralateral motor network. Through this in-vivo portrayal, the importance of non-primary motor regions for interhemispheric communication is emphasized. Additionally, distinct connectivity profiles were detected for the anterior and posterior subdivisions of primary motor cortex. The present findings provide a comprehensive representation of transcallosal white matter projections in humans, and have the potential to inform the development of models and hypotheses relating structural and functional brain connectivity.
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This paper details the results from a large European Union rotomoulding research project on the adaptation and development of industrial microwave oven technology to the rotational moulding process. Following computer modelling, an industrial scale microwave oven was specifically designed, manufactured and attached to the drop-arm of a convention rotational moulding machine where extensive moulding trials were carried out. The design and development of the microwave oven and test mould, together with the savings in terms of energy efficiency and mould heating rate that were achieved are discussed.