413 research outputs found

    Effects of air temperature on physiology and productive performance of pigs during growing and finishing phases

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    Thirty-six castrated male pigs were used to determine the influence of thermal environment and reduction of consumption on performance and carcass composition. Animals were housed in two climate chambers. In one, animals were in thermal comfort (TN) (22 °C), and in the other, pigs were under heat stress (HS) (34 °C). Animals were distributed in a randomized block design, making three treatments (TN, HS and animals in thermal comfort with food consumption paired with that observed in HS (PFTN)), with six replicates and two animals per experimental unit. Data were obtained on performance and carcass composition. The weight gains of HS and PFTN animals were reduced by 40.5% and 34.7%, respectively, reflecting a reduction of 13.2% in the final weight of PFTN animals. Triiodothyronine concentration was not affected by heat, but there was an increase in lymphocyte numbers in PFTN animals. The HS and PFTN animals showed lower hot carcass weight. However, there were no effects on hot carcass yield and relative weights of heart, lung and spleen. Heat stress compromised performance. The negative effects of high temperature on pigs include reduction in feed intake and changes in physiology.Keywords: Environment, heat stress, pair feed, pig growth, pig productio

    Enhancement of physical and reaction to fire properties of crude glycerol polyurethane foams filled with expanded graphite

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    The reation to fire of polyurethane foams (PUFs) has been a subject of increasing relevance, so in this study the reaction to fire performance of PUFs derived from crude glycerol (CG) has been improved using expanded graphite (EG). The influence of different loadings of EG on the physical–mechanical properties of composite foams has been assessed and the results obtained show that it has significant positive impact. Moreover, the reaction to fire of the PUF and EG/PUF composites has been investigated and the results obtained showed that the fire behavior of composite foams containing as little as 5 wt% of EG are significantly improved. Indeed a dramatic reduction of the rate of heat release, mass loss rate, effective heat of combustion and specific extinction area, has been observed even for a relative low amount of EG. Likewise, the use of Infrared Thermography as a function of time has proven that, when EG is used, the combustion stops suddenly and the temperature drops sharply compared with the behavior of the unfilled PUF sample, which suggests that EG acts like a flame extinguisher. The results obtained have proven the suitability of CG for the production of PUFs and that the addition of EG considerably improves the reaction to fire of composite foams.publishe

    The three-dimensional randomly dilute Ising model: Monte Carlo results

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    We perform a high-statistics simulation of the three-dimensional randomly dilute Ising model on cubic lattices L3L^3 with L256L\le 256. We choose a particular value of the density, x=0.8, for which the leading scaling corrections are suppressed. We determine the critical exponents, obtaining ν=0.683(3)\nu = 0.683(3), η=0.035(2)\eta = 0.035(2), β=0.3535(17)\beta = 0.3535(17), and α=0.049(9)\alpha = -0.049(9), in agreement with previous numerical simulations. We also estimate numerically the fixed-point values of the four-point zero-momentum couplings that are used in field-theoretical fixed-dimension studies. Although these results somewhat differ from those obtained using perturbative field theory, the field-theoretical estimates of the critical exponents do not change significantly if the Monte Carlo result for the fixed point is used. Finally, we determine the six-point zero-momentum couplings, relevant for the small-magnetization expansion of the equation of state, and the invariant amplitude ratio Rξ+R^+_\xi that expresses the universality of the free-energy density per correlation volume. We find Rξ+=0.2885(15)R^+_\xi = 0.2885(15).Comment: 34 pages, 7 figs, few correction

    Nova pesquisa sobre as coleções de Richard Spruce na Amazônia: uma colaboração Brasil-Reino Unido

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    The Northwest Amazon comprises a large region of equatorial forest on the border of Brazil, Colombia and Venezuela, which has been inhabited by indigenous peoples since the pre-colonial period. Today they occupy 80% of its area. Travellers such as Richard Spruce, who visited the region in the 1850s-1860s, described the vitality and dynamics of these populations, demonstrated by the size of their longhouses, their extensive inter-communal ceremonies, and their rich material culture. The biocultural objects and associated information collected by Richard Spruce constitute a unique point of reference for the useful plants, ethnobotany, anthropology and environmental history of the region. Housed at the Royal Botanic Gardens, Kew and the British Museum, both in London, this underresearched collection incorporates indigenous plant-based artefacts, samples of useful plant products, detailed archival notes on the use of plants by inhabitants of the Amazon, and accompanying herbarium voucher collections. This paper focusses on an ongoing research programme aimed at building capacity in Brazil to research, cataloguing and mobilising data from these biocultural collections, and developing these important resources for improved understanding of the useful and cultural properties of plants. It aims to build collaborative relationships, making biocultural collections and associated data freely accessible online, and above all to strengthen capacity of indigenous communities on the Rio Negro for autonomous research into material culture and plant use. We present the activities we have developed in the first two years of the programme. Workshops at Kew, Rio de Janeiro and São Gabriel da Cachoeira have enabled the Spruce collections to be fully digitised and artefacts made available through the Reflora portal (reflora.jbrj.gov. br). Training has been given in collection and study of biocultural objects, both to museum staff and representatives of indigenous communities, and a research agenda developed that focuses on better understanding of the shifting relationships between people and natural resources over the last 200 years. We discuss how a broad collaboration has led to constructive, culturally appropriate engagement with local communities, providing a portal into the world of scientific knowledge and helping to mobilise both scientific and indigenous knowledge in a mutually beneficial manner

    The role of phospho-tyrosine signaling in platelet biology and hemostasis

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    Platelets are small enucleated cell fragments specialized in the control of hemostasis, but also playing a role in angiogenesis, inflammation and immunity. This plasticity demands a broad range of physiological processes. Platelet functions are mediated through a variety of receptors, the concerted action of which must be tightly regulated, in order to allow specific and timely responses to different stimuli. Protein phosphorylation is one of the main key regulatory mechanisms by which extracellular signals are conveyed. Despite the importance of platelets in health and disease, the molecular pathways underlying the activation of these cells are still under investigation. Here, we review current literature on signaling platelet biology and in particular emphasize the newly emerging role of phosphatases in these processes

    Vascular Flora Of The Legado Das Águas, Reserva Votorantim, Municipalities Of Tapiraí, Miracatú And Juquiá, São Paulo, Brazil

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    Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)We present a list of vascular plants found in Legado das Águas, Reserva Votorantim, a private reserve having an area of approximately 35,000 ha that spans the municipalities of Tapiraí, Miracatú, and Juquiá, in the state of São Paulo, Brazil. The reserve is part of a complex of state-protected areas including Alto Ribeira Touristic State Park, Intervales State Park, Carlos Botelho State Park, Jurupará State Park, and Serra do Mar State Park. Together, these form an important and large area of continuous and well-preserved forest. Our study, which involved two main floristic surveys in March/April 2013 and April 2014, recorded 768 species, representing 131 families and 432 genera. The majority of species were angiosperms (619) representing 106 families and 370 genera. There were also two species of gymnosperms belonging to two genera in separate families; 147 species of ferns and lycophytes belonging to 23 families and 60 genera. In demonstrating the presence of almost 800 species of plants, of which 16 are threatened, our study highlights the importance of floristic surveys and the critical role of private protected areas in managing and preserving native flora. © 2016 Check List and Authors.1262011/22923-8, FAPESP, Fundação de Amparo à Pesquisa do Estado de São Paulo2015/9444-4, FAPESP, Fundação de Amparo à Pesquisa do Estado de São PauloFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP
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