24 research outputs found

    Open Issues on the Synthesis of Evolved Stellar Populations at Ultraviolet Wavelengths

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    In this paper we briefly review three topics that have motivated our (and others') investigations in recent years within the context of evolutionary population synthesis techniques. These are: The origin of the FUV up-turn in elliptical galaxies, the age-metallicity degeneracy, and the study of the mid-UV rest-frame spectra of distant red galaxies. We summarize some of our results and present a very preliminary application of a UV grid of theoretical spectra in the analysis of integrated properties of aged stellar populations. At the end, we concisely suggest how these topics can be tackled once the World Space Observatory enters into operation in the midst of this decade.Comment: 8 pages, 4 figures, accepted for publication in Astrophysics & Space Science, UV Universe special issu

    Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.

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    BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362

    Photosynthetic pathway variation among C4 grasses along a precipitation gradient in Argentina

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    Aim Based on the biochemical and physiological attributes of C4 grasses, and on the close association between decarboxylation pathways and the taxa in which they evolved, the hypotheses tested were: (1) that C4 grasses would become progressively more abundant as precipitation decreased, with grasses of the NADP-me subtype more abundant in wetter sites and those of the NAD-me subtype more common in arid regions; and (2) that the distribution of grass subfamilies would also be correlated with annual precipitation. Location The study was conducted along a precipitation gradient in central Argentina, from the eastern Pampas (>1000 mm year)1 ) to the western deserts and semi-deserts near the Andes (<100 mm year)1 ). Methods Percentage of species and relative cover of C3 and C4 grasses (including C4 subtypes) in local floras from 15 lowland sites of central Argentina were obtained from our own unpublished data and from recently published floristic surveys. Pearson correlation coefficients were obtained between grass distribution parameters and the available climatic data. Results The percentage of C4 grasses increased towards the arid extreme and showed a strong negative correlation with annual rainfall (r = )0.74, P < 0.01). Within the C4 subtypes, the NADP-me species showed a higher proportional representation at the wetter extreme, whereas the representation of NAD-me species increased towards the more arid extreme. The relationship of PEP-ck species with climatic parameters in central Argentina was less evident. The distributions of the Panicoideae and Chloridoideae subfamilies along the precipitation gradient were diametrically opposed, with the Panicoideae positively (r = 0.86, P < 0.001) and the Chloridoideae negatively (r = )0.87, P < 0.001) correlated with annual precipitation. Main conclusions Our data are consistent with the broad observation that C4 grasses tend to dominate in areas where the wet season falls in the warmer summer months. In agreement with previously reported results for Africa, Asia, Australia and North America, we describe here for the first time a significant relationship between annual precipitation and the prevalence of the NADP-me and NAD-me photosynthetic pathways along climatic gradients for the Neotropics. We also report for the first time that correlations between C4 species and annual rainfall are stronger when the relative cover of grass species is considered. The association of grass subfamilies Panicoideae and Chloridoideae with rainfall is as strong as that recorded for the NADP-me and NAD-me variants, respectively, suggesting that characteristics other than decarboxylation type may be responsible for the geographic patterns described in this studyFil: Cabido, Marcelo Ruben. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Pons, Stella Maris. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias; ArgentinaFil: Cantarero, Juan Jose. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria; ArgentinaFil: Lewis, Juan Pablo. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Anton, Ana Maria Ramona. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentin
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