2,113 research outputs found

    Arranjos e populações de plantas de milho e feijão no sistema consorciado em Sergipe.

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    bitstream/item/69094/1/CPATC-COM.-TEC.-02-79.pd

    The Brightest Lyα\alpha Emitter: Pop III or Black Hole?

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    CR7 is the brightest z=6.6Lyαz=6.6 \, {\rm Ly}\alpha emitter (LAE) known to date, and spectroscopic follow-up by Sobral et al. (2015) suggests that CR7 might host Population (Pop) III stars. We examine this interpretation using cosmological hydrodynamical simulations. Several simulated galaxies show the same "Pop III wave" pattern observed in CR7. However, to reproduce the extreme CR7 Lyα{\rm Ly}\alpha/HeII1640 line luminosities (Lα/HeIIL_{\rm \alpha/He II}) a top-heavy IMF and a massive (>107M>10^{7}{\rm M}_{\odot}) PopIII burst with age <2<2 Myr are required. Assuming that the observed properties of Lyα{\rm Ly}\alpha and HeII emission are typical for Pop III, we predict that in the COSMOS/UDS/SA22 fields, 14 out of the 30 LAEs at z=6.6z=6.6 with Lα>1043.3ergs1L_{\alpha} >10^{43.3}{\rm erg}\,{\rm s}^{-1} should also host Pop III stars producing an observable LHeII>1042.7ergs1L_{\rm He II}>10^{42.7}{\rm erg}\,{\rm s}^{-1}. As an alternate explanation, we explore the possibility that CR7 is instead powered by accretion onto a Direct Collapse Black Hole (DCBH). Our model predicts LαL_{\alpha}, LHeIIL_{\rm He II}, and X-ray luminosities that are in agreement with the observations. In any case, the observed properties of CR7 indicate that this galaxy is most likely powered by sources formed from pristine gas. We propose that further X-ray observations can distinguish between the two above scenarios.Comment: 6 pages, 4 figure

    Introdução e avaliação de gramíneas e leguminosas forrageiras na zona do litoral de Sergipe.

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    bitstream/item/88607/1/CPATC-PESQ.-AND.-30-85.pd

    Inexact restoration method for derivative-free optimization with smooth constraints

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    Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)A new method is introduced for solving constrained optimization problems in which the derivatives of the constraints are available but the derivatives of the objective function are not. The method is based on the inexact restoration framework, by means of which each iteration is divided in two phases. In the first phase one considers only the constraints, in order to improve feasibility. In the second phase one minimizes a suitable objective function subject to a linear approximation of the constraints. The second phase must be solved using derivative-free methods. An algorithm introduced recently by Kolda, Lewis, and Torczon for linearly constrained derivative-free optimization is employed for this purpose. Under usual assumptions, convergence to stationary points is proved. A computer implementation is described and numerical experiments are presented.A new method is introduced for solving constrained optimization problems in which the derivatives of the constraints are available but the derivatives of the objective function are not. The method is based on the inexact restoration framework, by means of23211891213CNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFAPERJ - FUNDAÇÃO CARLOS CHAGAS FILHO DE AMPARO À PESQUISA DO ESTADO DO RIO DE JANEIROFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)CNPq [E-26/171.164/2003-APQ1]FAPESP [FAPESP 2011-51305-0]FAPESP [03/09169-6, 06/53768-0, 07/06663-0, 08/00468-4]E-26/171.164/2003–APQ12011-51305-0; 03/09169-6; 06/53768-0; 07/06663-0; 08/00468-4sem informaçãoWe are indebted to associate editor Prof. Margaret Wright and two anonymous referees for many useful comments and remarks that led to significant improvement of this pape

    Criopreservação de Ovócitos e o Impacto da Pandemia COVID‑19

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    Egg freezing has evolved over the last decades, becoming an accepted and recognized technique for fertility preservation. This technique has various medical and non ‑medical indications and it is becoming an important step in overcoming age‑related de‑clines in fertility. Nonetheless, since it remains inadequately understood by the general public and medical professionals, raising its awareness is of vital importance. There are numerous factors that influence the technique’s success, particularly the number of matured eggs retrieved and the woman’s age, which affects the quantity and quality of oocytes. Women were prompted to more seriously contemplate social egg freezing throughout the COVID‑19 pandemic, given that social isolation complicated their search for an ideal male partner and allowed for more time to consider and research this topic.info:eu-repo/semantics/publishedVersio

    Entre a educação e a ciência:: um percurso acadêmico-institucional

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    Aula inaugural proferida em 27 de abril de 2016
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