Near-Infrared Time-Series Photometry in the Field of Cygnus OB2 Association I - Rotational Scenario For Candidate Members

In the last decades, the early pre main sequence stellar rotational evolution picture has been constrained by studies targeting different young regions at a variety of ages. Observational studies suggest a mass-rotation dependence, and for some mass ranges a connection between rotation and the presence of a circumstellar disk. Not still fully explored, though, is the role of environmental conditions on the rotational regulation. We investigate the rotational properties of candidate members of the young massive association Cygnus OB2. The Stetson variability index, Lomb-Scargle periodogram, Saunders statistics, string/rope length method, and visual verification of folded light curves were applied to select 1224 periodic variable stars. Completeness and contamination of the periodic sample was derived from Monte Carlo simulations, out of which 894 periods were considered reliable. Our study was considered reasonably complete for periods from 2 to 30 days. The general rotational scenario seen in other young regions is confirmed by Cygnus OB2 period distributions, with disked stars rotating on average slower than non-disked stars. A mass-rotation dependence was also verified, but as in NGC 6530, lower mass stars are rotating on average slower than higher mass stars, with an excess of slow rotators among the lower mass population. The effect of the environment on the rotational properties of the association was investigated by re-analysing the results while taking into account the incident UV radiation arising from O stars in the association. Results compatible with the disk-locking scenario were verified for stars with low UV incidence, but no statistical significant relation between rotation and disk presence was verified for stars with high UV incidence suggesting that massive stars can have an important role on regulating the rotation of nearby low mass stars.Comment: Submitted on December 23, 201

Marcadores genético-bioquímicos e resistência ao carrapato em bovinos.

Estudo da associação entre marcadores genético-bioquímicos e a resistência ao carrapato, foram analisados, preliminarmente, 60 animais (30 Canchim e 30 Nelore) para os sistemas albumina, transferrina e amilase em plasma sanguineo, e hemoglobina e anidrase carbônica em lisado de hemaceas

Estudo preliminar da relação entre marcadores genético-bioquímicos e resistência ao carrapato em gado de corte.

Relacionar os marcadores genético com a resistência ao carrapato, os animais foram classificados como sendo de alta ou baixa resistência

Dynamical Mass Constraints on Low-Mass Pre-Main-Sequence Stellar Evolutionary Tracks: An Eclipsing Binary in Orion with a 1.0 Msun Primary and an 0.7 Msun Secondary

We report the discovery of a double-lined, spectroscopic, eclipsing binary in the Orion star-forming region. We analyze the system spectroscopically and photometrically to empirically determine precise, distance-independent masses, radii, effective temperatures, and luminosities for both components. The measured masses for the primary and secondary, accurate to ~1%, are 1.01 Msun and 0.73 Msun, respectively; thus the primary is a definitive pre-main-sequence solar analog, and the secondary is the lowest-mass star yet discovered among pre-main-sequence eclipsing binary systems. We use these fundamental measurements to test the predictions of pre-main-sequence stellar evolutionary tracks. None of the models we examined correctly predict the masses of the two components simultaneously, and we implicate differences between the theoretical and empirical effective temperature scales for this failing. All of the models predict the observed slope of the mass-radius relationship reasonably well, though the observations tend to favor models with low convection efficiencies. Indeed, considering our newly determined mass measurements together with other dynamical mass measurements of pre-main-sequence stars in the literature, as well as measurements of Li abundances in these stars, we show that the data strongly favor evolutionary models with inefficient convection in the stellar interior, even though such models cannot reproduce the properties of the present-day Sun.Comment: Accepted by Ap

As relações mulher-terra na revista Agriculturas: análise temática e léxica.

Resumo: Através dos artigos da revista Agriculturas, procurou-se entender, qual o lugar e importância das mulheres, a percepção dos autores sobre a contribuição das mulheres e as principais atividades que elas desenvolvem. Os artigos foram selecionados quando tratavam de qualquer temática relacionada às mulheres e Agroecologia. As mulheres representadas atuam diretamente nas atividades produtivas da propriedade e atividades associadas ao desenvolvimento de políticas públicas. Abstract:Through articles of the journal Agriculturas about women and Agroecology, this work studied what is their place and significant role, the authors perception os their contribution and activities performed. The women in the selected articles accomplish activities in the rural property and others associated with the development of public policies

Classificação de bovinos em função de suas medidas lineares obtidas com processamento de imagens digitais.

Este trabalho apresenta um sistema informatizado que automatiza a obtenção de medidas lineares em bovinos, com o uso de técnicas do processamento de imagens digitais, bem como viabiliza a classificação com procedimentos estatísticos Bayesianos. Resultados obtidos com estudo de casos mostraram a sensibilidade do método para a classificação e indicação de classes de populações de bovinos reprodutores, de corte, leiteiro ou ainda classes rejeitadas. A opção pelo desenvolvimento no ambiente C++ Builder forneceu funcionalidades e facilidades operativas devido à utilização de menus, o que tornou o sistema amigável e viável para qualificar um método para a classificação de bovinos, o que é de interesse para o segmento agropecuário

Estimativas de efeitos aditivos e heteróticos para características de crescimento em bovinos Charolês-Nelore.

Resumo