27 research outputs found
Determining the Physical Properties of the B Stars I. Methodology and First Results
We describe a new approach to fitting the UV-to-optical spectra of B stars to
model atmospheres and present initial results. Using a sample of lightly
reddened stars, we demonstrate that the Kurucz model atmospheres can produce
excellent fits to either combined low dispersion IUE and optical photometry or
HST FOS spectrophotometry, as long as the following conditions are fulfilled:
1) an extended grid of Kurucz models is employed,
2) the IUE NEWSIPS data are placed on the FOS absolute flux system using the
Massa & Fitzpatrick (1999) transformation, and
3) all of the model parameters and the effects of interstellar extinction are
solved for simultaneously.
When these steps are taken, the temperatures, gravities, abundances and
microturbulence velocities of lightly reddened B0-A0 V stars are determined to
high precision. We also demonstrate that the same procedure can be used to fit
the energy distributions of stars which are reddened by any UV extinction curve
which can be expressed by the Fitzpatrick & Massa (1990) parameterization
scheme.
We present an initial set of results and verify our approach through
comparisons with angular diameter measurements and the parameters derived for
an eclipsing B star binary. We demonstrate that the metallicity derived from
the ATLAS 9 fits to main sequence B stars is essentially the Fe abundance. We
find that a near zero microturbulence velocity provides the best-fit to all but
the hottest or most luminous stars (where it may become a surrogate for
atmospheric expansion), and that the use of white dwarfs to calibrate UV
spectrophotometry is valid.Comment: 17 pages, including 2 pages of Tables and 6 pages of Figures.
Astrophysical Jounral, in pres
Uso del recuento folicular a campo. Impacto del recuento de folículos antrales sobre la fertilidad de vaquillonas para carne.
El recuento de folículos antrales (RFA) está asociado con la fertilidad (Evans et al., 2012). Vacas lecheras con bajo RFA tienen una menor performance reproductiva, expresada por un incremento en los días entre el parto y el primer servicio y entre el parto y la concepción (Martinez et al., 2016). Investigaciones sobre el RFA y fertilidad en ganado de carne son muy escasas en el mundo. Estudios en ésta temática podrían revelar asociaciones con importantes implicancias en la selección de vaquillonas de reposición en los rodeos de cría. En vaquillonas para carne, el RFA está relacionado con el momento de la concepción, aspecto relevante en la productividad y longevidad de las vacas (Cushman et al., 2013). Otro aspecto importante es que ésta herramienta se ha utilizado para seleccionar vaquillonas que son servidas por primera vez a los 14 meses de edad, en sistemas de producción intensivos. En este trabajo nos planteamos la hipótesis de que el RFA está relacionado con el comportamientoreproductivo en el primer servicio con 24 meses de vaquillonas de razas carniceras manejadas en las condiciones de explotación de Uruguay, y que esta información podría utilizarse para rechazar vaquillonas antes del servicio y mejorar el desempeño reproductivo del rodeo de cría
Influence of selenite resistant rhizobacteria on the SeO32- phytoextraction efficiency of Brassica juncea grown on water-filtering artificial beds
The role of the rhizobacteria inhabiting the rhizosphere of Brassica juncea in selenite phytoextraction are discussed with reference to water-filtering artificial beds
Laparoscopic para-aortic lymph node sampling for pancreatic duct adenocarcicoma – An oncological practice
Self-Construction, Cognitive Conflicts, and Disordered Eating Attitudes in Young Women
The aim of this study is to identify cognitive variables that predict disordered eating attitudes in a nonclinical sample composed of 50 female university students. Repertory grid technique was used to assess cognitive features of self-construing and cognitive conflicts. Drive for Thinness and Body Dissatisfaction scales from the Eating Disorder Inventory 2 were used as dependent variables, as previous studies suggested that high scores on these scales are associated with the risk of developing or aggravating eating syndromes. Results suggest that drive for thinness can be associated with cognitive conflicts, whereas body dissatisfaction may be higher for those who construct themselves as inadequate and similar to others. In addition, both dependent variables were predicted by being younger and having a higher body mass index
Metabolic syndrome in HIV-infected patients receiving antiretroviral therapy in Latin America
OBJECTIVE: To evaluate the prevalence of and the associated factors for metabolic syndrome (MS) among Latin American HIV-infected patients receiving antiretroviral therapy (ART) using baseline data from the RAPID II study. METHODS: A longitudinal study to evaluate the metabolic profile, cardiovascular disease (CVD) risk and associated treatment practices to reduce this risk has been conducted in seven Latin American countries (the RAPID II study). Adult HIV patients with at least six months of RT were enrolled. MS was defined following ATP-III criteria. Demographic and anthropometric data, serum biochemical and clinical parameters were compared in patients with and without MS using bivariate and multivariate analysis. RESULTS: A total of 4,010 patients were enrolled, 2,963 (74%) were males. Mean age (SD) was 41.9 (10.0) years. The prevalence of MS was 20.2%. Females had higher prevalence of MS than males (22.7% vs. 19.4%, p = 0.02). MS was driven by high triglycerides, low HDL-cholesterol and high blood pressure (HBP). Patients with MS had higher 10year CVD risk: 22.2% vs. 7.4%, p < 0.001. Age (OR: 1.05 per year), female gender (OR: 1.29), family history of CVD (OR: 1.28), CD4 cell count (OR: 1.09 per 100 cell increase), and protease inhibitor based-ART (OR: 1.33) correlated with MS in the multivariate analysis. CONCLUSIONS: Prevalence of MS in this setting was similar to that reported from developed countries. MS was driven by high triglycerides, low-HDL and HBP, and it was associated with higher risk of CVD. Traditional risk factors, female gender, immune reconstitution, and protease inhibitor based-ART correlated with MS