A5008216554- Stellar, planetary, and galactic studies
- Astrophysics and Star Formation Studies
- Astronomy and Astrophysical Research
- Astro and Planetary Science
- Astrophysical Phenomena and Observations
- Genetic Associations and Epidemiology
- Diabetes and associated disorders
- Chemical Thermodynamics and Molecular Structure
- Phase Equilibria and Thermodynamics
- Race, Genetics, and Society
- Galectins and Cancer Biology
- Atmospheric Ozone and Climate
- Hemoglobinopathies and Related Disorders
- Cosmology and Gravitation Theories
- T-cell and B-cell Immunology
- Adaptive optics and wavefront sensing
- Folate and B Vitamins Research
- Forensic and Genetic Research
- Protein Tyrosine Phosphatases
- Vitamin D Research Studies
- Business and Management Studies
- Impact of Light on Environment and Health
- Space Exploration and Technology
- Education and Public Policy
- Science and Science Education
Universidade Federal de Sergipe
2020-2024
Universidade de São Paulo
2010-2020
Universidade Cidade de São Paulo
2018
Universidade Católica de Brasília
2009-2012
Ancestry informative SNPs can be useful to estimate individual and population biogeographical ancestry. Brazilian is characterized by a genetic background of three parental populations (European, African, Native Amerindians) with wide degree diverse patterns admixture. In this work we analyzed the information content 28 ancestry-informative into multiplexed panels using sources (African, Amerindian, European) infer admixture in an urban sample five geopolitical regions. The assigned apart...
We apply the viscous decretion disc (VDD) model to interpret infrared continuum emission of 80 Be stars observed in different epochs. In this way, we determined 169 specific structures, namely their density scale, ρ0, and exponent, n. found that n values range mainly between 1.5 3.5, ρ0 varies 10−12 10−10 g cm−3, with a peak close lower value. Our large sample also allowed us firmly establish discs around early-type are denser than late-type stars. Additionally, estimated mass rates they...
Be stars are main-sequence massive with emission features in their spectrum, which originates circumstellar gaseous discs. Even though the viscous decretion disc model can satisfactorily explain most observations, two important physical ingredients, namely magnitude of viscosity (α) and mass injection rate, remain poorly constrained. The light curves that undergo events formation dissipation offer an opportunity to constrain these quantities. A pipeline was developed use a grid synthetic...
Rapid rotation is a fundamental characteristic of classical Be stars and crucial property allowing for the formation their circumstellar disks. Past evolution in mass angular momentum transferring binary system offers plausible solution to how attained fast rotation. Although subdwarf remnants donors such systems should exist abundance, only few have been confirmed due tight observational constraints. An indirect method detecting otherwise hidden companions offered by effect on outer parts...
Context. The structure of the inner parts Be star disks (20 stellar radii) is well explained by viscous decretion disk (VDD) model, which able to reproduce observable properties most objects studied so far. outer parts, on ther hand, are not observationally well-explored, as they only at radio wavelengths. A steepening spectral slope somewhere between infrared and wavelengths was reported for several stars that were previously detected in radio, but a convincing physical explanation this...
Bulge globular clusters (GCs) with metallicities [Fe/H] <~ -1.0 and blue horizontal branches are candidates to harbor the oldest populations in Galaxy. Based on analysis of HST proper-motion-cleaned color-magnitude diagrams filters F435W F625W, we determine physical parameters for old bulge NGC 6522 6626 (M28), both well-defined branches. We compare these results similar data inner halo cluster 6362. These have (-1.3 <= -1.0) obtained from high resolution spectroscopy. derive ages, distance...
Be stars are surrounded by outflowing circumstellar matter structured in the form of decretion discs. They often members binary systems, where it is expected that disc interacts both radiatively and gravitationally with companion. In this work we study how various orbital (period, mass ratio eccentricity) (viscosity) parameters affect structure coplanar systems. We simulate such binaries use a smoothed particle hydrodynamics code. The main effects secondary on its truncation accumulation...
Context: Lupus is recognised as one of the closest star-forming regions, but lack trigonometric parallaxes in pre-Gaia era hampered many studies on kinematic properties this region and led to incomplete censuses its stellar population. Aims: We use second data release Gaia space mission combined with published ancillary radial velocity revise census stars investigate 6D structure complex. Methods: performed a new membership analysis association based astrometric photometric over field 160...
Background: Population stratification is the main source of spurious results and poor reproducibility in genetic association findings. heterogeneity can be controlled for by grouping individuals ethnic clusters; however, admixed populations, there evidence that such proxies do not provide efficient control. The aim this study was to evaluate relation self-reported with ancestry statistical risk an sample based on ancestry.Methods: A questionnaire included item completed 189 female volunteers...
We investigate the continuum emission of viscous decretion discs around Be stars in this paper. The results obtained from non-LTE (local thermodynamic equilibrium) radiative transfer models show two regimes disc surface brightness profile: an inner optically thick region, which behaves as a pseudo-photosphere with wavelength-dependent size, and thin tenuous outer part, contributes about third total flux. isophotal shape is well described by elliptical contours axial ratio b/a = cos i for...
We present spatially and spectrally resolved Br-gamma emission around the planet-hosting, transitional Herbig Ae/Be star HD 100546. Aiming to gain insight into physical origin of line in possible relation accretion processes, we carried out spectro-interferometry using AMBER/VLTI from three different baselines achieving spatial spectral resolutions 2-4 mas 12000. The visibility is larger than that continuum for all baselines. Differential phases reveal a shift between photocentre -displaced...
We analyzed V-band photometry of the Be star {\omega} CMa, obtained during last four decades, which went through complete cycles disc formation and dissipation. The data were simulated by hydrodynamic models based on a time-dependent implementation viscous decretion (VDD) paradigm, in around fast-spinning is formed material ejected driven to progressively larger orbits means torques. Our simulations offer good description photometric variability phases dissipation, suggests that VDD model...
The VISCACHA (VIsible Soar photometry of star Clusters in tApii and Coxi HuguA) Survey is an ongoing project based on deep photometric observations Magellanic Cloud clusters, collected using the SOuthern Astrophysical Research (SOAR) telescope together with SOAR Adaptive Module Imager. Since 2015 more than 200 h time were used to observe about 130 stellar most them low mass (M < 104 M⊙) and/or located outermost regions Large Small Cloud. With this high-quality data set, we homogeneously...
The viscous decretion disk (VDD) model is able to explain most of the currently observable properties circumstellar disks Be stars. However, more stringent tests, focusing on reproducing multitechnique observations individual targets via physical modeling, are needed study predictions VDD under specific circumstances. In case nearby, bright star $\beta$ CMi, these circumstances a very stable low-density and late-type (B8Ve) central star. aim test thoroughly, exploiting full diagnostic...
ABSTRACT This paper presents chemical abundances of 12 elements (C, Na, Mg, Al, Si, K, Ca, Ti, V, Cr, Mn, and Fe) for 80 FGK dwarfs in the Pleiades open cluster, which span a temperature range $\sim$2000 K T$_{\rm eff}$, using high-resolution (R$\sim$22 500) near-infrared SDSS (Sloan Digital Sky Survey)-IV/APOGEE (Apache Point Observatory Galactic Evolution Experiment) spectra ($\lambda$1.51–1.69 $\mu$m). Using 1D local thermodynamic equilibrium abundance analysis, we determine an overall...
The vitamin D receptor (VDR) is an essential protein related to bone metabolism. Some VDR alleles are differentially distributed among ethnic populations and display variable patterns of linkage disequilibrium (LD). In this study, 200 unrelated Brazilians were genotyped using 21 single nucleotide polymorphisms (SNPs) 28 ancestry informative markers. LD haplotype distribution compared Brazilian the HapMap African (YRI), European (CEU) Asian (JPT+CHB) origins. Conditional regression...
The prevalence of metabolic disorders varies among ethnic populations and these represent a critical health care issue for elderly women. This study investigated the correlation between genetic ancestry body composition, traits clinical status in sample Clinical, nutritional anthropometric data were collected from 176 volunteers. Genetic was estimated using 23 ancestry-informative markers. Pearsons test used to examine relationship continuous variables an independent samples t-test compare...
A sample of 27 sources, catalogued as pre-main sequence stars by the Pico dos Dias Survey (PDS), is analyzed to investigate a possible contamination post-AGB stars. The far-infrared excess, due dust present in circumstellar envelope, typical for both categories: young and objects that have already left main are suffering severe mass-loss. presence two known our inspired us seek other very likely or among PDS sources previously suggested be Herbig Ae/Be stars, revisiting observational...
ABSTRACT Classical B emission (Be) stars are fast rotating, near-main-sequence B-type stars. The rotation and the presence of circumstellar discs profoundly modify observables active Be Our goal is to infer stellar disc parameters, as well distance interstellar extinction, using currently most favoured physical models for these objects. We present BeAtlas, a grid $61\, 600$ non-local thermodynamic equilibrium radiative transfer stars, calculated with hdust code. was coupled Monte Carlo...
The rs2476601-T allele at the protein tyrosine phosphatase non-receptor type 22 (PTPN22) gene has been consistently associated with several autoimmune diseases in European-derived populations. However, little is known about and haplotype frequency distributions PTPN22 among populations derived from other ethnic groups. In present study, of six single nucleotide polymorphisms (SNPs) were compared Brazilian HapMap phase 3 dataset. A total 10 different population samples evaluated....
The CTLA-4 protein is expressed in activated T cells and plays an essential role the immune response through its regulatory effect on cell activation. Polymorphisms of gene have been correlated with autoimmune, neoplastic infectious illnesses. This work aimed to verify possible associations between single nucleotide polymorphisms (SNPs) CTLA-4, -318C/T promoter +49A/G exon 1 paracoccidioidomycosis (PCM) caused by Paracoccidioides brasiliensis. For this purpose, 66 chronic form PCM patients...
Abstract The VISCACHA (VIsible Soar photometry of star Clusters in tApii and Coxi HuguA † ) Survey is an ongoing project based on deep spatially resolved photometric observations Magellanic Cloud clusters, collected using the SOuthern Astrophysical Research (SOAR) telescope together with SOAR Adaptive Module Imager. So far we have used >300h time to observe ∼150 mostly low mass ( M < 10 4 ⊙ outskirts LMC SMC. With this high-quality data set, homogeneously determine physical properties...