694 research outputs found

    Dislocation loops in overheated free-standing smectic films

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    Static and dynamic phenomena in overheated free-standing smectic-A films are studied using a generalization of de Gennes' theory for a confined presmectic liquid. A static application is to determine the profile of the film meniscus and the meniscus contact angle, the results being compared with those of a recent study employing de Gennes' original theory. The dynamical generalization of the theory is based on on a time-dependent Ginzburg-Landau approach. This is used to compare two modes for layer-thinning transitions in overheated films, namely "uniform thinning" vs. nucleation of dislocation loops. Properties such as the line tension and velocity of a moving dislocation line are evaluated self-consistently by the theory.Comment: 16 pages, 8 figure

    HLA homozygosity does not adversely affect measles vaccine-induced cytokine responses

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    AbstractThe association between HLA homozygosity and measles-specific Th1 (IFN-γ, IL-2 and IL-12p40) and Th2 (IL-4 and IL-10) cytokine responses were assessed in a group of 339 healthy schoolchildren 12–18 years of age previously immunized with two doses of live-attenuated measles virus vaccine. No associations were observed between class I HLA homozygosity and measles-specific cytokine levels. Children who were homozygous at the class II DRB1, DQA1, DPA1 and DPB1 loci had higher median IFN-γ secretion levels compared with children who were heterozygous for DRB1 (77.7 vs. 39.5 pg/ml, p=0.05), DQA1 (60.9 vs. 36.6 pg/ml, p=0.03), DPA1 (46.1 vs. 27.1 pg/ml, p=0.01) and DPB1 (61.5 vs. 36.0 pg/ml, p=0.01) loci, respectively. Homozygosity at increasing numbers of HLA loci ( >=4) was associated with increased IFN-γ secretion levels (test for trend p-value=0.01). Our results suggest that HLA homozygosity showed no disadvantage for measles-specific cytokine responses and instead was associated with increased IFN-γ levels

    Replication of EPHA1 and CD33 associations with late-onset Alzheimer's disease: a multi-centre case-control study

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    <p>Abstract</p> <p>Background</p> <p>A recently published genome-wide association study (GWAS) of late-onset Alzheimer's disease (LOAD) revealed genome-wide significant association of variants in or near <it>MS4A4A, CD2AP, EPHA1 </it>and <it>CD33</it>. Meta-analyses of this and a previously published GWAS revealed significant association at <it>ABCA7 </it>and <it>MS4A</it>, independent evidence for association of <it>CD2AP, CD33 </it>and <it>EPHA1 </it>and an opposing yet significant association of a variant near <it>ARID5B</it>. In this study, we genotyped five variants (in or near <it>CD2AP, EPHA1, ARID5B</it>, and <it>CD33</it>) in a large (2,634 LOAD, 4,201 controls), independent dataset comprising six case-control series from the USA and Europe. We performed meta-analyses of the association of these variants with LOAD and tested for association using logistic regression adjusted by age-at-diagnosis, gender, and <it>APOE ε4 </it>dosage.</p> <p>Results</p> <p>We found no significant evidence of series heterogeneity. Associations with LOAD were successfully replicated for <it>EPHA1 </it>(rs11767557; OR = 0.87, p = 5 × 10<sup>-4</sup>) and <it>CD33 </it>(rs3865444; OR = 0.92, p = 0.049), with odds ratios comparable to those previously reported. Although the two <it>ARID5B </it>variants (rs2588969 and rs494288) showed significant association with LOAD in meta-analysis of our dataset (p = 0.046 and 0.008, respectively), the associations did not survive adjustment for covariates (p = 0.30 and 0.11, respectively). We had insufficient evidence in our data to support the association of the <it>CD2AP </it>variant (rs9349407, p = 0.56).</p> <p>Conclusions</p> <p>Our data overwhelmingly support the association of <it>EPHA1 </it>and <it>CD33 </it>variants with LOAD risk: addition of our data to the results previously reported (total n > 42,000) increased the strength of evidence for these variants, providing impressive p-values of 2.1 × 10<sup>-15 </sup>(<it>EPHA1</it>) and 1.8 × 10<sup>-13 </sup>(<it>CD33</it>).</p

    Relative Intake of Macronutrients Impacts Risk of Mild Cognitive Impairment or Dementia

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    Abstract. High caloric intake has been associated with an increased risk of cognitive impairment. Total caloric intake is determined by the calories derived from macronutrients. The objective of the study was to investigate the association between percent of daily energy (calories) from macronutrients and incident mild cognitive impairment (MCI) or dementia. Participants were a population-based prospective cohort of elderly persons who were followed over a median 3.7 years (interquartile range, 2.5-3.9) of follow-up. At baseline and every 15 months, participants (median age, 79.5 years) were evaluated using the Clinical Dementia Rating scale, a neurological evaluation, and neuropsychological testing for a diagnosis of MCI, normal cognition, or dementia. Participants also completed a 128-item food-frequency questionnaire at baseline; total daily caloric and macronutrient intakes were calculated using an established database. The percent of total daily energy from protein (% protein), carbohydrate (% carbohydrate), and total fat (% fat) was computed. Among 937 subjects who were cognitively normal at baseline, 200 developed incident MCI or dementia. The risk of MCI or dementia (hazard ratio, [95% confidence interval]) was elevated in subjects with high % carbohydrate (upper quartile: 1.89 [1.17-3.06]; p for trend = 0.004), but was reduced in subjects with high % fat (upper quartile: 0.56 [0.34-0.91]; p for trend = 0.03), and high % protein (upper quartile 0.79 [0.52-1.20]; p for trend = 0.03) in the fully adjusted models. A dietary pattern with relatively high caloric intake from carbohydrates and low caloric intake from fat and proteins may increase the risk of MCI or dementia in elderly persons
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