A study of the elements copper through uranium in Sirius A: Contributions from STIS and ground-based spectra

We determine abundances or upper limits for all of the 55 stable elements from copper to uranium for the A1 Vm star Sirius. The purpose of the study is to assemble the most complete picture of elemental abundances with the hope of revealing the chemical history of the brightest star in the sky, apart from the Sun. We also explore the relationship of this hot metallic-line (Am) star to its cooler congeners, as well as the hotter, weakly- or non-magnetic mercury-manganese (HgMn) stars. Our primary observational material consists of {\em Hubble Space Telescope} ($HST$) spectra taken with the Space Telescope Imaging Spectrograph (STIS) in the ASTRAL project. We have also used archival material from the %\citep/{ayr10}. $COPERNICUS$ satellite, and from the $HST$ Goddard High-Resolution Spectrograph (GHRS), as well as ground-based spectra from Furenlid, Westin, Kurucz, Wahlgren, and their coworkers, ESO spectra from the UVESPOP project, and NARVAL spectra retrieved from PolarBase. Our analysis has been primarily by spectral synthesis, and in this work we have had the great advantage of extensive atomic data unavailable to earlier workers. We find most abundances as well as upper limits range from 10 to 100 times above solar values. We see no indication of the huge abundance excesses of 1000 or more that occur among many chemically peculiar (CP) stars of the upper main sequence. The picture of Sirius as a hot Am star is reinforced.Comment: With 6 Figures and 4 Tables; accepted for publication in Ap

Respiratory symptoms and cross-shift lung function in relation to cotton dust and endotoxin exposure in textile workers in Nepal: a cross-sectional study

Objectives: Inhalation of a cotton-based particulates has previously been associated with respiratory symptoms and impaired lung function. This study investigates the respiratory health of Nepalese textile workers in relation to dust and endotoxin exposure. Methods: A total of 938 individuals from four sectors (garment, carpet, weaving and recycling) of the textile industry in Kathmandu, Nepal completed a health questionnaire and performed spirometry. A subset (n=384) performed cross-shift spirometry. Personal exposure to inhalable dust and airborne endotoxin was measured during a full shift for 114 workers. Results: The overall prevalence of persistent cough, persistent phlegm, wheeze ever, breathlessness ever and chest tightness ever was 8.5%, 12.5%, 3.2%, 6.5% and 12.3%, respectively. Symptoms were most common among recyclers and least common among garment workers. Exposure to inhalable dust significantly predicted persistent cough and chest tightness. Exposure to endotoxin did not have any independent predictive effect. Significant cross-shift reduction in forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) were found (p<0.001 for both) being largest for FEV1 in the recyclers (−143 mL), and least in the garment workers (−38 mL; p=0.012). Exposure to inhalable dust predicted a cross-shift reduction in FEV1. Conclusions: This study is the first to investigate the respiratory health of Nepalese cotton workers. The measured association between inhalable dust exposure and reporting of respiratory symptoms and across-shift decrement in FEV1 and FVC indicates that improved dust control measures should be instituted, particularly in the recycling and carpet sectors. The possible role of other biologically active agents of cotton dust beyond endotoxin should be further explored

A systematic review of associations between environmental exposures and development of asthma in children aged up to 9 years

Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.Peer reviewedPublisher PD

Solar abundance corrections derived through 3D magnetoconvection simulations

We explore the effect of the magnetic field when using realistic three-dimensional convection experiments to determine solar element abundances. By carrying out magnetoconvection simulations with a radiation-hydro code (the Copenhagen stagger code) and through a-posteriori spectral synthesis of three Fe I lines, we obtain evidence that moderate amounts of mean magnetic flux cause a noticeable change in the derived equivalent widths compared with those for a non-magnetic case. The corresponding Fe abundance correction for a mean flux density of 200 G reaches up to ~0.1 dex in magnitude. These results are based on space- and time-averaged line profiles over a time span of 2.5 solar hours in the statistically stationary regime of the convection. The main factors causing the change in equivalent widths, namely the Zeeman broadening and the modification of the temperature stratification, act in different amounts and, for the iron lines considered here, in opposite directions; yet, the resulting $|\Delta\log\epsilon_{\odot}(Fe)|$ coincides within a factor two in all of them, even though the sign of the total abundance correction is different for the visible and infrared lines. We conclude that magnetic effects should be taken into account when discussing precise values of the solar and stellar abundances and that an extended study is warranted.Comment: ApJ accepte

Study of Alpha-Sigma Phase Transformation in Mechanically Alloyed Fe-Cr-Sn Alloys

The solubility of tin is significantly extended by mechanical alloying in near equiatomic Fe-Cr alloys. The influences of Sn concentration and of grain size on the kinetics of formation of the sigma-phase have been studied using different techniques. The sigma-phase formation is much faster for as-milled alloys than it is for conventional alloys. The sigma-phase formation rate decreases with the increase of Sn concentration in alloys with nanometer-sized grains as it does in coarse-grained alloys. The mechanisms which are responsible for the slowing-down of the alpha-sigma transformation are different in both kinds of alloys

BUSCA de Biomarcadores em Longevidade Humana: Investigação dos Genes Mthfd1l e Serpina3

A longevidade humana, tempo que excede a expectativa média de vida da população, é uma característica multifatorial determinada por fatores ambientais e de predisposição genética. Apesar de vários estudos investigarem a influência de componentes ambientais na longevidade, o papel de variantes genéticas nesta característica ainda não está bem esclarecido. Genes que participam do metabolismo de aminoácidos e genes que atuam em processos inflamatórios, como os genes MTHFD1L e SERPINA3, respectivamente, poderiam influenciar nas variações de tempo de vida de indivíduos de uma população. Assim, este estudo teve como objetivo avaliar se existe associação dos polimorfismos de MTHFD1L (rs11754661) e SERPINA3 (rs4934) com a longevidade humana em indivíduos atendidos em um hospital de referência no atendimento de geriatria da Grande Vitória-ES, Brasil. Foram selecionados 436 participantes, divididos em grupos de longevos (acima de 85 anos) e idosos com idade próxima a expectativa de vida da população (entre 70 e 75 anos). A genotipagem foi realizada por PCR em tempo real e os polimorfismos identificados estavam em equilíbrio de Hardy-Weinberg. As análises estatísticas foram realizadas por meio dos testes de Odds Ratio (OR) com Intervalo de Confiança de 95%, &#967;² e Fisher, com p-value &#8804;0,05. Não foi observada associação do polimorfismo rs4934 do gene SERPINA3 com a longevidade. Todavia, o alelo G do polimorfismo rs11754661 do gene MTHFD1L se comportou como um alelo de risco para a longevidade humana na população analisada (p=0,027; OR=1,976; IC 95% variando de 1,080 a 3,616), bem como o genótipo GG (p=0,030; OR=2,006; IC 95% variando de 1,070-3,761), enquanto que o genótipo AG atuou como fator de proteção (p=0,041; OR=0,518; IC 95% variando de 0,275 a 0,974). Os resultados sugerem que o polimorfismo rs11754661 do gene MTHFD1L está associado com a longevidade humana na amostra de indivíduos da Grande Vitória-ES, Brasil e que o polimorfismo rs4934 do gene SERPINA3 não está associado com longevidade na amostra avaliada

Resistance or resignation to welfare reform? The activist politics for and against social citizenship

Since 2008, mature welfare states have, to varying degrees, pursued a strategy of welfare reform that has reconfigured the dominant praxis of social citizenship. Drawing on qualitative data from two studies, this paper explores what bearing this has had on the political subjectivity of welfare claimants in the New Zealand context. The findings suggest welfare claimants engage in diverse political struggles for and against social citizenship to resist, reconfigure and resign themselves to the prevailing socio-political settlement. In light of this, conclusions are drawn about the insurgent politics of low-income social security claimants as political agents in the citizenship-making process

Introducing Optics in the Kindergarten

Introducing Optics in the Kindergarteninfo:eu-repo/semantics/publishedVersio

Addition of the apical oblique projection increases the detection of acute traumatic shoulder abnormalities in adults

Purpose Plain radiographic evaluation of acute shoulder trauma in adults requires a minimum of two projections, commonly the anteroposterior (AP) and lateral scapular projections, with additional projections taken for diagnosis. The aim of this retrospective study was to determine whether the addition of the apical oblique (AO) projection to the AP and lateral scapular projections increases the number and/or alters the types of abnormalities detected in the examination of acute shoulder trauma. Methods Examinations of 56 adults who had undergone three-projection (AP, lateral scapular, AO) radiographic shoulder examination for acute trauma were allocated into two-projection (AP, lateral scapular) and three-projection cases and assessed by a radiologist. The differences in number and types of abnormalities between the two-projection and three-projection cases were quantified using the one-tailed t test and chi-square goodness-of-fit test, respectively. Results Test-retest reliability was moderate (intra-class correlation coefficient [95%CI], 0.56 [0.15 to 0.80]) for number, and almost perfect (kappa [95%CI], 0.94 [0.85 to 1.00]) for types, of abnormalities detected. There was a significant increase in the number of abnormalities detected across all three-projection versus two-projection cases (difference in means [95%CI], 0.20 [0.01 to 0.39]) and for fractures (difference in means [95%CI], 0.30 [0.11 to 0.49]), but no difference in the types of abnormalities detected (χ 2 = 4.7, p = 0.19). Conclusion This study suggests that adding the AO projection to two-projection examination of acute shoulder trauma increases the number of abnormalities detected; this has potential implications for patient management. Further research investigating differences in types of abnormalities detected between two-projection and three-projection cases is warranted