7,316 research outputs found

    Composición corporal y parámetros sanguíneos de lechones Alentejanos y Large White × Landrace recién nacidos

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    This study aimed to compare the body composition and some blood parameters [(glucose, albumin and insulin-like growth factor 1 (IGF-1)] of newborn piglets farrowed by unselected Alentejano (AL) or conventional genotype [(Large-White × Landrace (LL)]. Carcasses (12 of each genotype) and blood samples were obtained from a total of 34 litters (18 AL, 16 LL). Gestation length was 4d shorter in AL sows compared with LL sows. When adjusted for birth weight, carcasses of AL piglets showed higher percentages of dry matter (PEl objetivo de este estudio fue comparar la composición corporal y los parámetros sanguíneos [albúmina, glucosa y factor de crecimiento insulínico tipo 1 (IGF-1)] de lechones recién nacidos procedentes de cerdas de raza no seleccionada Alentejana (AL) y de genotipo convencional [(Large-White × Landrace (LL)]). Se analizaron muestras de sangre y canal (12 de cada genotipo) de un total de 34 camadas (18 AL y 16 LL). Las cerdas AL presentaron gestaciones 4 días más cortas que las cerdas LL. Cuando se ajustaron para el peso al nacimiento, las canales de los lechones AL presentaron mayores porcentajes de materia seca (

    Arsenic in rice agrosystems (water, soil and rice plants) in Guayas and Los Rios provinces, Ecuador

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    Geogenic arsenic (As) can accumulate and reach high concentrations in rice grains, thus representing a potential threat to human health. Ecuador is one of the main consumers of rice in South America. However, there is no information available about the concentrations of As in rice agrosystems, although some water bodies are known to contain high levels of the element. We carried out extensive sampling of water, soil, rice plants and commercial rice (obtained from local markets). Water samples were analysed to determine physico-chemical properties and concentrations of dissolved arsenic. Soil samples were analysed to determine total organic C, texture, total Fe and amorphous Fe oxyhydroxides (Fe-ox), total arsenic (tAs) and the bioavailable fraction (As-Me). The different plant parts were analysed separately to determine total (tAs), inorganic (iAs) and organic arsenic (oAs). Low concentrations of arsenic were found in samples of water (generally 80%) in all parts of the rice plants. (C) 2016 Elsevier B.V. All rights reserved

    Stability of undissociated screw dislocations in zinc-blende covalent materials from first principle simulations

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    The properties of perfect screw dislocations have been investigated for several zinc-blende materials such as diamond, Si, β\beta-SiC, Ge and GaAs, by performing first principles calculations. For almost all elements, a core configuration belonging to shuffle set planes is favored, in agreement with low temperature experiments. Only for diamond, a glide configuration has the lowest defect energy, thanks to an sp2^2 hybridization in the core

    Glass/polyvinyl chloride composites

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    This paper summarizes the results obtained in the use of plastisols of vinyl chloride homopolymer (PVC), obtained by the process of emulsion polymerization, as thermoplastic matrix in the production of composite pipes and in pipe repairing. Two processing techniques commonly used with thermosetting matrices were studied: filament winding and hand lay-up. The produced composite structures of PVC reinforced with glass fibres were subsequently subjected to tests in order to determine their mechanical properties. This paper concludes that it is possible to use the described technique for piping repairing with good results

    Static Configurations of Dark Energy and Dark Matter

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    We study static configurations of dark matter coupled to a scalar field responsible for the dark energy of the Universe. The dark matter is modelled as a Fermi gas within the Thomas-Fermi approximation. The mass of the dark matter particles is a function of the scalar field. We analyze the profile of the dark matter halos in galaxies. In this case our framework is equivalent to the model of the isothermal sphere. In the presence of a scalar field, the velocity of a massive object orbiting the galaxy is not of the order of the typical velocity of the dark matter particles, as in the conventional picture. Instead, it is reduced by a factor that quantifies the dependence of the dark matter mass on the scalar field. This has implications for dark matter searches. We derive new solutions of the Einstein equations which describe compact objects composed of dark matter. Depending on the scale of the dark matter mass, the size of these objects can vary between microscopic scales and cosmological distances. We determine the mass to radius relation and discuss the similarities with conventional neutron stars and exotic astrophysical objects.Comment: 23 pages, 3 figures, minor additions to the tex

    Persistência dos efeitos da escarificação sobre a compactação de Nitossolo sob plantio direto em região subtropical úmida.

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    Avalia a persistência dos efeitos da escarificação sobre a compactação de Nitossolo Vermelho, manejado sob plantio direto (PD), na região subtropical úmida do Brasil. O experimento foi realizado em blocos ao acaso, com quatro repetições e seis tratamentos, constituídos pelo tempo de manutenção do solo sob PD após escarificação: PD contínuo por 24 meses após escarificação, realizada setembro de 2009; PD contínuo por 18 meses após escarificação, realizada em março de 2010; PD contínuo por 12 meses após escarificação, realizada em setembro de 2010; PD contínuo por seis meses após escarificação, realizada em março de 2011; plantio realizado em solo recém escarificado, em setembro de 2011; e PD contínuo e sem escarificação (testemunha). As espécies cultivadas na área foram: milho, safra 2009/2010; trigo, em 2010; soja, safra 2010/2011; centeio, em 2011; e milho, safra 2011/2012. Os efeitos dos tratamentos foram avaliados a partir de parâmetros físicos do solo e de parâmetros morfológicos e produtivos da cultura do milho, na safra 2011/2012. A escarificação do Nitossolo sob plantio direto, em região de clima subtropical úmido, não aumenta a produtividade de grãos de milho, e os seus efeitos sobre a estrutura do solo não persistem por mais de 18 meses
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