119 research outputs found

    Cardiac autonomic activity during sleep in high-altitude resident children compared with lowland residents

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    Study Objectives We aimed to characterize heart-rate variability (HRV) during sleep in Andean children native to high altitude (HA) compared with age, gender, and genetic ancestry-similar low-altitude (LA) children. We hypothesized that the hypoxic burden of sleep at HA could induce variation in HRV. As children have otherwise healthy cardiovascular systems, such alterations could provide early markers of later cardiovascular disease. Methods Twenty-six LA (14F) and 18 HA (8F) children underwent a single night of attended polysomnography. Sleep parameters and HRV indices were measured. Linear mixed models were used to assess HRV differences across sleep stage and altitude group. Results All children showed marked fluctuations in HRV parameters across sleep stages, with higher vagal activity during nonrapid eye movement sleep and greater variability of the heart rate during rapid eye movement (REM). Moreover, HA children showed higher very low-frequency HRV in REM sleep and, after adjusting for heart rate, higher low-to-high frequency ratio in REM sleep compared with children living at lower altitude. Conclusions We confirmed previous findings of a stage-dependent modulation of HRV in Andean children living at both HA and LA. Moreover, we showed subtle alteration of HRV in sleep in HA children, with intriguing differences in the very low-frequency domain during REM sleep. Whether these differences are the results of an adaptation to high-altitude living, or an indirect effect of differences in oxyhemoglobin saturation remains unclear, and further research is required to address these questions

    Beyond the MHC: A canine model of dermatomyositis shows a complex pattern of genetic risk involving novel loci

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    Juvenile dermatomyositis (JDM) is a chronic inflammatory myopathy and vasculopathy driven by genetic and environmental influences. Here, we investigated the genetic underpinnings of an analogous, spontaneous disease of dogs also termed dermatomyositis (DMS). As in JDM, we observed a significant association with a haplotype of the major histocompatibility complex (MHC) (DLA-DRB1*002:01/-DQA1*009:01/-DQB1*001:01), particularly in homozygosity (P-val = 0.0001). However, the high incidence of the haplotype among healthy dogs indicated that additional genetic risk factors are likely involved in disease progression. We conducted genome-wide association studies in two modern breeds having common ancestry and detected strong associations with novel loci on canine chromosomes 10 (P-val = 2.3X10-12) and 31 (P-val = 3.95X10-8). Through whole genome resequencing, we identified primary candidate polymorphisms in conserved regions of PAN2 (encoding p.Arg492Cys) and MAP3K7CL(c.383_392ACTCCACAAA\u3eGACT) on chromosomes 10 and 31, respectively. Analyses of these polymorphisms and the MHC haplotypes revealed that nine of 27 genotypic combinations confer high or moderate probability of disease and explain 93% of cases studied. The pattern of disease risk across PAN2 and MAP3K7CL genotypes provided clear evidence for a significant epistatic foundation for this disease, a risk further impacted by MHC haplotypes. We also observed a genotype-phenotype correlation wherein an earlier age of onset is correlated with an increased number of risk alleles at PAN2 and MAP3K7CL. High frequencies of multiple genetic risk factors are unique to affected breeds and likely arose coincident with artificial selection for desirable phenotypes. Described herein is the first three-locus association with a complex canine disease and two novel loci that provide targets for exploration in JDM and related immunological dysfunction

    UReCA, the NCHC Web journal of Undergraduate Research and Creative Activity

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    Our vision is an academic community without borders, a connected network of aspirational students committed to the advancement of knowledge and appreciation of the arts. UReCA fosters the exchange of intellectual and creative work between undergraduate students, providing a platform where students can engage with and contribute to the advancement of their individual fields. UReCA was first conceived by Johnny MacLean (Southern Utah University) and Brian White (Graceland University) at an annual NCHC conference in Phoenix, Arizona. MacLean and White noticed that while several academic outlets existed for honors faculty and administrators, there was an absence of student-focused publications within the NCHC community. Inspired by the experiential education model used by Partners in the Parks, Johnny and Brian saw another opportunity for honors students to engage in experiential learning. Their vision: an international undergraduate journal, peer reviewed and produced for the web by an interdisciplinary community of honors students

    Childhood socioeconomic position and objectively measured physical capability levels in adulthood: a systematic review and meta-analysis

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    <p><b>Background:</b> Grip strength, walking speed, chair rising and standing balance time are objective measures of physical capability that characterise current health and predict survival in older populations. Socioeconomic position (SEP) in childhood may influence the peak level of physical capability achieved in early adulthood, thereby affecting levels in later adulthood. We have undertaken a systematic review with meta-analyses to test the hypothesis that adverse childhood SEP is associated with lower levels of objectively measured physical capability in adulthood.</p> <p><b>Methods and Findings:</b> Relevant studies published by May 2010 were identified through literature searches using EMBASE and MEDLINE. Unpublished results were obtained from study investigators. Results were provided by all study investigators in a standard format and pooled using random-effects meta-analyses. 19 studies were included in the review. Total sample sizes in meta-analyses ranged from N = 17,215 for chair rise time to N = 1,061,855 for grip strength. Although heterogeneity was detected, there was consistent evidence in age adjusted models that lower childhood SEP was associated with modest reductions in physical capability levels in adulthood: comparing the lowest with the highest childhood SEP there was a reduction in grip strength of 0.13 standard deviations (95% CI: 0.06, 0.21), a reduction in mean walking speed of 0.07 m/s (0.05, 0.10), an increase in mean chair rise time of 6% (4%, 8%) and an odds ratio of an inability to balance for 5s of 1.26 (1.02, 1.55). Adjustment for the potential mediating factors, adult SEP and body size attenuated associations greatly. However, despite this attenuation, for walking speed and chair rise time, there was still evidence of moderate associations.</p> <p><b>Conclusions:</b> Policies targeting socioeconomic inequalities in childhood may have additional benefits in promoting the maintenance of independence in later life.</p&gt

    Synthetic Social Support: Theorizing Lay Health Worker Interventions

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    Levels of social support are strongly associated with health outcomes and inequalities. The use of lay health workers (LHWs) has been suggested by policy makers across the world as an intervention to identify risks to health and to promote health, particularly in disadvantaged communities. However, there have been few attempts to theorize the work undertaken by LHWs to understand how interventions work. In this article, the authors present the concept of 'synthetic socialsupport' and distinguish it from the work of health professionals or the spontaneous social support received from friends and family. The authors provide new empirical data to illustrate the concept based on qualitative, observational research, using a novel shadowing method involving clinical and non-clinical researchers, on the everyday work of 'pregnancy outreach workers' (POWs) in Birmingham, UK. The service was being evaluated as part of a randomized controlled trial. These LHWs provided instrumental, informational, emotional and appraisal support to the women they worked with, which are all key components of social support. The social support was 'synthetic' because it was distinct from the support embedded in spontaneous social networks: it was non-reciprocal; it was offered on a strictly time-limited basis; the LHWs were accountable for the relationship, and the social networks produced were targeted rather than spontaneous. The latter two qualities of this synthetic form of social support may have benefits over spontaneous networks by improving the opportunities for the cultivation of new relationships (both strong and weak ties) outside the women's existing spontaneous networks that can have a positive impact on them and by offering a reliable source of health information and support in a chaotic environment. The concept of SSS can help inform policy makers about how deploying lay workers may enable them to achieve desired outcomes, specify their programme theories and evaluate accordingly. [Abstract copyright: Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

    Harmonization of Neuroticism and Extraversion phenotypes across inventories and cohorts in the Genetics of Personality Consortium : an application of Item Response Theory

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