20 research outputs found

    Radiative properties of stellar plasmas and open challenges

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    The lifetime of solar-like stars, the envelope structure of more massive stars, and stellar acoustic frequencies largely depend on the radiative properties of the stellar plasma. Up to now, these complex quantities have been estimated only theoretically. The development of the powerful tools of helio- and astero- seismology has made it possible to gain insights on the interiors of stars. Consequently, increased emphasis is now placed on knowledge of the monochromatic opacity coefficients. Here we review how these radiative properties play a role, and where they are most important. We then concentrate specifically on the envelopes of β\beta Cephei variable stars. We discuss the dispersion of eight different theoretical estimates of the monochromatic opacity spectrum and the challenges we need to face to check these calculations experimentally.Comment: 6 pages, 5 figures, in press (conference HEDLA 2010

    Bio-analytical Assay Methods used in Therapeutic Drug Monitoring of Antiretroviral Drugs-A Review

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    New insights into the genetic etiology of Alzheimer's disease and related dementias

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    Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele

    Multiancestry analysis of the HLA locus in Alzheimer’s and Parkinson’s diseases uncovers a shared adaptive immune response mediated by HLA-DRB1*04 subtypes

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    Across multiancestry groups, we analyzed Human Leukocyte Antigen (HLA) associations in over 176,000 individuals with Parkinson’s disease (PD) and Alzheimer’s disease (AD) versus controls. We demonstrate that the two diseases share the same protective association at the HLA locus. HLA-specific fine-mapping showed that hierarchical protective effects of HLA-DRB1*04 subtypes best accounted for the association, strongest with HLA-DRB1*04:04 and HLA-DRB1*04:07, and intermediary with HLA-DRB1*04:01 and HLA-DRB1*04:03. The same signal was associated with decreased neurofibrillary tangles in postmortem brains and was associated with reduced tau levels in cerebrospinal fluid and to a lower extent with increased Aβ42. Protective HLA-DRB1*04 subtypes strongly bound the aggregation-prone tau PHF6 sequence, however only when acetylated at a lysine (K311), a common posttranslational modification central to tau aggregation. An HLA-DRB1*04-mediated adaptive immune response decreases PD and AD risks, potentially by acting against tau, offering the possibility of therapeutic avenues

    Sexual harassment and menstrual disorders among Italian university women: A cross-sectional observational study

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    Aims: Menstrual disorders and sexual harassment are common among young women and interfere with their life and activities. We aimed to describe the association of sexual harassment and menstrual disorders among female university students. Methods: This cross-sectional, observational study examined the association between sexual harassment and menstrual disorders in a sample of 349 university students in Italy. Students answered an anonymous self-administered questionnaire. Descriptive bivariate analyses and logistic regression analyses were performed. Main outcome measures were associations between levels of exposure to sexual harassment (none, levels 1 and 2) and five menstrual disorders (premenstrual symptoms, heavy bleeding, pain, irregular cycles, and amenorrhea). Results: Among the women interviewed (mean age 20.4 \ub1 1.45 years), 146 (41.8%) had experienced sexual harassment in the previous 12 months: 91 (26.1%) level 1 and 55 (15.7%) level 2. The frequency of premenstrual symptoms was 31.9% (n=110); heavy bleeding, 35.3% (n=124); pain, 51.4% (n=181); irregular cycles, 55.5% (n=195); and amenorrhea, 6.7% (n=23). After adjustment for age, place of birth, being in a couple relationship and receiving hormone therapy, the frequency of menstrual disorders, except for amenorrhea, was increased with sexual harassment, with a regular gradient from no harassment to level 2 harassment. Introducing factors of depression, specific gynaecological problems and lifetime sexual violence did not change the results. For instance, the adjusted odds ratios of premenstrual symptoms were 2.10 [1.19\u20133.68] for women with level 1 harassment and 3.58 [1.83\u20137.03] for women with level 2 compared with women without harassment exposure. Conclusions: Sexual harassment is related to the prevalence of menstrual disorders. Healthcare providers should encourage dialogue with patients and address the issue of sexual violence or harassment

    Avaliação de duas fontes de metionina a dois níveis de adição no desempenho de frangos de corte (1-49 dias) Evaluation of two synthetic sources of methionine, on the performance of broilers (1-49 days)

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    O experimento foi conduzido no Setor de Avicultura do Departamento de Zootecnia da Universidade Federal de Santa Maria (RS), no período de 12 de setembro à 01 de novembro de 1989, com o objetivo de avaliar os efeitos de diferentes fontes e níveis de adição de aminoácido metionina, através do desempenho de aves (machos e fêmeas) criados separadamente no período de 1 - 49 dias. Foram utilizados 640 pintos de corte, sexados, da linhagem Hubbard. O delineamento experimental utilizado foi o inteiramente casualizado, num esquema fatorial 2 x 2 x 2 (2 fontes x 2 níveis x 2 sexos) com quatro repetições de 20 aves cada unidade experimental. As fontes foram: DL-Metionina e Methionina Hidróxi-Análoga (MHA), com dois níveis de metionina suplementar: 1500 e 1050ppm, nível alto e baixo de cada, respectivamente; sendo que na fase inicial (1 - 20 dias) utilizou-se 100% destes níveis, no crescimento, (21 - 42 dias) 83,3% e na fase de terminação (43 - 49 dias), 75% destes níveis. As dietas foram calculadas para serem isonutritivas, diferindo apenas nos níveis de peso, consumo alimentar, conversão alimentar, viabilidade criatória e índice de eficiência produtiva. Apesar de ter havido diferenças significativas nos períodos inicial, crescimento e terminação enttre alguns tratamentos, no período total (1 - 49 dias) estas diferenças não foram significativas (P > 0,05) evidenciando uma compensação de ganho de peso. Na análise estatística do consumo alimentar verificou-se na fase inicial (1 - 20 dias) houve diferenças significativas (F = 5,97 P < 0,0223) para machos, onde o consumo alimentar foi maior na fonte de MHA em nível alto. Na fase de terminação (43 - 49 dias) houve diferença significativa (P< 0,01) entre sexos onde os machos obtiveram melhor conversão alimentar que as fêmeas. Para o item índice de eficiência produtiva, houve diferença significativa (P < 0,05), entre os sexos, onde os machos demonstraram ser 21,4% mais eficientes que as fêmeas. O escore de empenamento foi significativamente melhor para fêmeas. Gordura abdominal e rendimento de carcaça não foram influenciados pelas fontes ou níveis de metionina, mas diferenças altamente significativa entre sexos, onde as fêmeas tiveram 26,2% mais gordura abdominal que os machos e o rendimento de carcaça foi 2,7% melhor para machos. Conclui-se que ambas as fontes de metionina, em base equimolar de adição, podem ser usadas para frangos de corte, sem redução no desempenho.<br>This study was conducted in the Poultry Section of the Animal Science Department at the Federal University of Santa Maria, RS - Brazil, from September 12th to November 1st, 1989. The main objective was to evaluate the effect of two different sources and levels of synthetic methionine on the broiler performance, raised separetely by sex, from day old up to 49 days of age. A total of 640 dayold chicks, from both sexes, on pen floor were used. The experimental design was enterely randomized in a factorial 2 x 2 x 2 (source x level x sex) with 4 replicates of 20 chicks each. The sources of methionine were DL-Methionine and Methionine Hidroxy-analogue, and the levels were 1.500 and 1.050ppm for phase I (1 - 20 days); for phase II (20 - 42 days) and phase III (42 - 49 days), were 83.33 and 75.0% of the phase I, respectively. Diets contained 20.5, 19.5 and 17.5% of crude protein and 3.000, 3.050 and 3.100kcal/kg of ME for phase I, II and III, respectively. In all phases, males were significantly better than females for all parameters studied. Weight gain was different at phases I and III for sources and levels, but not in the overall period which demonstrates a compensatory growth through the period. Feed consumption and feed conversion for the overall period (1 - 49 days) did not show significant differences for sources or levels. Viability was similar between sexes and also related to sources or levels of methionine suplementation. The productive efficiency index (IEP) was 21.4% better for males than females. Feathering score was significantly better for females. The abdominal fat and carcass yield were not affected by sources or levels of methionine, but highly differents between sexes; females had 26.2% more abdominal fat deposition than males, and the carcass yield was 2.7% better for males. It was concluded that both sources of methionine (DL-Methionine or MHA) on a equimolar basis of adition for broiler diets, can be used without any reduction of performance
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