4,902 research outputs found

    A NOTE ON COMONOTONICITY AND POSITIVITY OF THE CONTROL COMPONENTS OF DECOUPLED QUADRATIC FBSDE

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    In this small note we are concerned with the solution of Forward-Backward Stochastic Differential Equations (FBSDE) with drivers that grow quadratically in the control component (quadratic growth FBSDE or qgFBSDE). The main theorem is a comparison result that allows comparing componentwise the signs of the control processes of two different qgFBSDE. As a byproduct one obtains conditions that allow establishing the positivity of the control process.Comment: accepted for publicatio

    Comparação da eficiência de fontes de fósforo na produção de arroz de terras altas.

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    O arroz de terras altas é importante componente dos sistemas de produção na região do Cerrado do Brasil. A deficiência de fósforo é um dos fatores limitantes na produção das culturas nessa região. Foi conduzido um ensaio em casa de vegetação com o objetivo de avaliar fontes de fósforo na produção de arroz de terras altas. Foram utilizadas seis fontes de P, i. e. Superfosfato simples (SFS), superfosfato simples policote (SFSP), superfosfato triplo (SFT), superfosfato triplo policote SFTP), fosfato monoamômico (FMA) e fosfato monoamômicopolicote (FMAP). As doses de P utilizados foram 50, 100, 200 e 400 mg kg-1 + testemunha. Houve resposta significativa e quadrática à aplicação de fontes de P na produção de grãos. Baseado na produção máxima, as fontes de P foram classificadas na ordem de fosfato monoamômicopolicote> superfosfato simples = fosfato monoamômico>superfosfatosimples policote > superfosfato triplo > superfosfato triplo policote

    Construção de estufas para produção de hortaliças nas Regiões Norte, Nordeste e Centro-Oeste.

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    bitstream/CNPH-2009/31468/1/ct_38.pd

    On the search for the chiral anomaly in Weyl semimetals: The negative longitudinal magnetoresistance

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    Recently, the existence of massless chiral (Weyl) fermions has been postulated in a class of semi-metals with a non-trivial energy dispersion.These materials are now commonly dubbed Weyl semi-metals (WSM).One predicted property of Weyl fermions is the chiral or Adler-Bell-Jackiw anomaly, a chirality imbalance in the presence of parallel magnetic and electric fields. In WSM, it is expected to induce a negative longitudinal magnetoresistance (NMR), the chiral magnetic effect.Here, we present experimental evidence that the observation of the chiral magnetic effect can be hindered by an effect called "current jetting". This effect also leads to a strong apparent NMR, but it is characterized by a highly non-uniform current distribution inside the sample. It appears in materials possessing a large field-induced anisotropy of the resistivity tensor, such as almost compensated high-mobility semimetals due to the orbital effect.In case of a non-homogeneous current injection, the potential distribution is strongly distorted in the sample.As a consequence, an experimentally measured potential difference is not proportional to the intrinsic resistance.Our results on the MR of the WSM candidate materials NbP, NbAs, TaAs, TaP exhibit distinct signatures of an inhomogeneous current distribution, such as a field-induced "zero resistance' and a strong dependence of the `measured resistance" on the position, shape, and type of the voltage and current contacts on the sample. A misalignment between the current and the magnetic-field directions can even induce a "negative resistance". Finite-element simulations of the potential distribution inside the sample, using typical resistance anisotropies, are in good agreement with the experimental findings. Our study demonstrates that great care must be taken before interpreting measurements of a NMR as evidence for the chiral anomaly in putative Weyl semimetals.Comment: 13 pages, 6 figure

    Análise in silico de genes de Caseíno-quinases tipo I e II de Coffea arabica.

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    As proteínas quinases são enzimas fundamentais na transmissão de sinais intra e extracelulares de organismos eucariotos, incluindo organismos unicelulares, animais e plantas. Esta classe de enzimas é responsável pela regulação de inúmeros processos celulares, incluindo divisão celular, expressão gênica, desenvolvimento de tecidos, entre outros. No gênero Coffea, há pouca informação sobre as proteínas quinases e o papel que desempenham. Este trabalho tem como objetivo identificar genes semelhantes a caseíno-quinase tipo I e caseíno-quinase tipo II, através da análise in silico utilizando a base de dados do CafEST

    A Nuclear Localization Signal and a Membrane Association Domain Contribute to the Cellular Localization of the Tobacco Mosaic Virus 126-kDa Replicase Protein

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    AbstractA transient expression system using onion epidermal cells was used to investigate domains of the Tobacco mosaic virus (TMV) 126-kDa replicase protein involved in cellular localization. Initially, a nuclear localization signal (NLS), identified within the amino-terminus of the 126-kDa protein, was investigated for its functionality using fusion constructs containing the green fluorescent protein (GFP). Fusion of the amino-terminal 70 amino acids of the 126-kDa protein, containing the NLS, to a β-glucuronidase-GFP open reading frame (ORF), directed the accumulation of fluorescence to the nucleus. In contrast, similar constructs lacking the NLS or containing a mutated NLS sequence failed to accumulate within the nucleus. Additional investigations using GFP fusion constructs containing the first 178 or 388 amino acids of the 126-kDa protein also displayed nuclear localization. However, fusion constructs encoding the first 781 amino acids or the entire 126-kDa ORF did not accumulate within the nucleus but instead associated with the endoplasmic reticulum (ER), forming spot-like inclusions. Thus, a dominant ER association domain exists between amino acids 388 and 781 of the 126-kDa protein. Interestingly, a full-length 126-kDa GFP fusion construct encoding a nonfunctional NLS mutation also localized to the ER but did not form inclusions. Furthermore, a TMV mutant containing the same nonfunctional NLS mutation failed to replicate in protoplasts. Together these findings suggest that both the NLS and the ER retention domain contribute to the functional localization of the 126-kDa protein

    Floração de espécies apícolas no Pantanal baseada em informações de herbário e literatura.

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    O objetivo desse estudo foi descrever e avaliar a influência do porte das plantas apícolas do Pantanal na ocorrência de floração ao longo do ano. As informações das espécies apícolas foram organizadas a partir da compilação de dados de literatura e do acervo do herbário CPAP, anotando-se o período de floração, porte de crescimento (herbáceo, arbustivo, arbóreo ou trepadeira), sendo que as palmeiras foram consideradas como de porte arbóreo, e a ocorrência ou não em área inundável (espécies aquáticas ou anfíbias e terrestres).bitstream/CPAP-2010/57290/1/BP91.pd
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