1,367 research outputs found

    Compatible blends of thermoplastic starch and hydrolyzed ethylene-vinyl acetate copolymers

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    AbstractEthylene-vinyl acetate copolymer (EVA) with 19% of vinyl acetate and its derivatives modified by hydrolysis of 50 and 100% of the initial vinyl acetate groups were used to produce blends with thermoplastic starch (TPS) plasticized with 30wt% glycerol. The blends were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction, water absorption, stress–strain mechanical tests, dynamic mechanical analysis and thermogravimetric analysis. In contrast to the blends with unmodified EVA, those made with hydrolyzed EVA were compatible, as demonstrated by the brittle fracture surface analysis and the results of thermal and mechanical tests. The mechanical characteristics and water absorption of the TPS were improved even with a small addition (2.5wt%) of hydrolyzed EVA. The glass transition temperature rose with the degree of hydrolysis of EVA by 40 and 50°, for the EVA with 50 and 100% hydrolysis, respectively. The addition of hydrolyzed EVA proved to be an interesting approach to improving TPS properties, even when very small quantities were used, such as 2.5wt%

    Effects of the Energy Error Distribution of Fluorescence Telescopes on the UHECR energy spectrum

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    The measurement of the ultra high energy cosmic ray (UHECR) spectrum is strongly affected by uncertainties on the reconstructed energy. The determination of the presence or absence of the GZK cutoff and its position in the energy spectrum depends not only on high statistics but also on the shape of the energy error distribution. Here we determine the energy error distribution for fluorescence telescopes, based on a Monte Carlo simulation. The HiRes and Auger fluorescence telescopes are simulated in detail. We analyze the UHECR spectrum convolved with this energy error distribution. We compare this spectrum with one convolved with a lognormal error distribution as well as with a Gaussian error distribution. We show that the energy error distribution for fluorescence detectors can not be represented by these known distributions. We conclude that the convolved energy spectrum will be smeared but not enough to affect the GZK cutoff detection. This conclusion stands for both HiRes and Auger fluorescence telescopes. This result differs from the effect of the energy error distribution obtained with ground detectors and reinforces the importance of the fluorescence energy measurement. We also investigate the effect of possible fluorescence yield measurement errors in the energy spectrum.Comment: 24 pages, 11 figure

    Size matters: fishing less and yielding more in smaller-scale fisheries

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    Several factors influence catches and the sustainability of fisheries, and such factors might be different depending on the scale on which fisheries work. We investigated the existence of possible subdivisions within small-scale fisheries (SSF) themselves, regarding their economic performance and relative social and environmental impacts to understand which categories of these two types of fleets are best positioned to support sustainability. By doing so, we investigated if it is a good strategy for SSF to aim to grow towards larger scales. We obtained economic and ecological data from landing samplings and information on technological efficiency of this fleet, using a northeastern Brazilian state as a case study. We defined a cut-off point to separate the SSF into two categories of boats, according to their size and gear. We compared their cpue and the factors affecting it within each category; we also compared economic (number of boats, number of landings, jobs, gears, catch, travel time and total time of the fishery, revenues, costs, profits, revenue per unit of effort, and profit per unit of effort) and ecological factors (vulnerability of species caught) between the two categories. We found that small boats spent less time fishing and employed comparatively more people per landed value and catch. The cpue and profits of small boats were also higher. Both large and small boats exploit species with the same overall vulnerability. Therefore, being smaller, even within the SSF category, seems to be a more advantageous social and economic strategy for guaranteeing higher catches and more employment opportunities per catch. These findings need to be taken into account when defining new policies, such as the distribution of subsidies that support or not the sustainable use of fishery resources

    Trabalhadores Usuários De Drogas Em Recuperação Em Uma Região Industrial Do Brasil

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    Context: The number of illicit drug users worldwide is estimated at 210 million people annually, of which at least 200,000 die as a result. Drug abuse affects not only the user but also their family, friends, coworkers, and community. Objective: This study outlines a sociodemographic profle of workers undergoing treatment for chemical dependency recovery in Campinas (SP). Method: Cross-sectional, exploratory study with data collected in rehabilitation centers for chemical dependency treatment in Campinas by means of a self-administered and anonymous questionnaire. The research was conducted between July 2011 and July 2012 and focused on the analysis of health and work conditions. The study included workers who were followed for more than 30 days (n=200). Results: 87.8% of the population were aged 18-54 years. Most of them had completed high school, had an income of some kind, and of which 54.5% were formally employed. 48.4% hadcontract positions of less than one year and 42.1% had a salary range below R$1,020.00 (Brazilian real). Conclusion: This study provides information not explored in other studies and has a potential value related to the prevention, treatment, and rehabilitation of workers in similar conditions.142788

    TOPOGRAFIA DOS COLATERAIS CALIBROSOS DO ARCO AÓRTICO DE UM MÃO - PELADA (Procyon cancrivorus GRAY, 1865) (CARNIVORA PROCYONIADAE)

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    Estudou-se a topografia dos colaterais calibrosos do arco aórtico em um exemplar de Procyon cancrivorus, adulto, macho, proveniente da Fazenda Experimental do Glória, da Universidade Federal de Uberlândia, MG, Brasil, o qual teve seus vasos arteriais injetados com solução corada de Neoprene Latex 450, com posterior fixação em solução aquosa de formol a 10% e submetidos à dissecação. O arco aórtico encontra-se em correspondência à terceira costela, no antímero esquerdo da cavidade torácica. O primeiro ramo calibroso do arco aórtico é o tronco braquiocefálico, situado medialmente à terceira costela, originando as artérias carótida comum esquerda, carótida comum direita e a subclávia direita, em correspondência ao primeiro espaço intercostal. A artéria subclávia esquerda é o segundo ramo emergente do arco aórtico, originando-se medialmente à terceira costela. As artérias subclávias direita e esquerda, cedem os mesmos colaterais em ambos os antímeros, ou seja, tronco costocervical esquerdo (medialmente à primeira costela), tronco costocervical direito (borda cranial da primeira costela), artérias cervical superficial esquerda e cervical superficial direita (borda cranial da primeira costela), artéria torácica interna esquerda (medialmente à segunda costela) e artéria torácica interna direita (borda cranial da primeira costela). The topography of the thick collaterals of the aortic arch in a crab eating raccoon Procyon cancrivorus Gray, 1865, Carnivora Procyoniadae Abstract An anatomical study has been carried out on the topography of the thick collateral branches of the aortic arch in an adult male specimen of raccoon (Procyon cancrivorus) from the Gloria Experimental Farm, Federal University of Uberlandia MG, Brasil. For this purpose, the arterial blood vessels were injected with a ruddy solution of Neoprene Latex 450, fixed by means of a 10% aqueous solution of formaldehyde and then dissected. It has been observed that the aortic arch is in correspondence with the third rib at the left side of the thoracic cavity The first thick branch of the aortic arch is the brachiocephalic trunk which is situaded medially in regard to the third rib, originating the left common carotid artery, the right common carotid artery and the right subclavian artery in correspondence with the first intercostal space. The left subclavian artery is the second emerging branch of the aortic arch originating itself medialy to the third rib. The right and the left subclavian arteries give way to the same collaterals in both sides, as the left costocervical trunk (medially to the first rib), the right costocervical trunk (cranial edge of the first rib), the left and the right superficial cervical arteries (cranial edge of the first rib, the left internal thoracic artery (medially to the second rib), and the right internal thoracic artery (cranial edge of the first rib)

    Future environmental and agricultural impacts of Brazil's Forest Code

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    The role of improving the enforcement of Brazil's Forest Code in reducing deforestation in the Amazon has been highlighted in many studies. However, in a context of strong political pressure for loosening environmental protections, the future impacts of a nationwide implementation of the Forest Code on both environment and agriculture remain poorly understood. Here, we present a spatially explicit assessment of Brazil's 2012 Forest Code through the year 2050; specifically, we use a partial equilibrium economic model that provides a globally consistent national modeling framework with detailed representation of the agricultural sector and spatially explicit land-use change. We test for the combined or isolated impacts of the different measures of the Forest Code, including deforestation control and obligatory forest restoration with or without environmental reserve quotas. Our results show that, if rigorously enforced, the Forest Code could prevent a net loss of 53.4 million hectares (Mha) of forest and native vegetation by 2050, 43.1 Mha (81%) of which are in the Amazon alone. The control of illegal deforestation promotes the largest environmental benefits, but the obligatory restoration of illegally deforested areas creates 12.9 Mha of new forested area. Environmental reserve quotas further protect 5.8 Mha of undisturbed natural vegetation. Compared to a scenario without the Forest Code, by 2050, cropland area is only reduced by 4% and the cattle herd by 8%. Our results show that compliance with the Forest Code requires an increase in cattle productivity of 56% over four decades, with a combination of a higher use of supplements and an adoption of semi-intensive pasture management. We estimate that the enforcement of the Forest Code could contribute up to 1.03 PgCO<sub>2</sub>e to the ambitious GHG emissions reduction target set by Brazil for 2030

    TOPOGRAFIA DO CONE MEDULAR EM UM GATO MOURISCO, Herpailurus yagouaroundi (Severtzow, 1858)(FELIDAE)

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    A anestesia caudal foi proposta pela primeira vez em 1926 e diversas técnicas foram desenvolvidas para anestesiar os nervos espinhais lombares e sacrais. Os métodos para anestesia epidural exigem conhecimento da anatomia da região envolvida. O objetivo deste estudo foi determinar a topografia do cone medular do gato mourisco, tornando possível a realização desta técnica anestésica em um felino silvestre de nossa fauna. Uma gata mourisca, adulta, proveniente do Zoológico Parque do Sabiá, Uberlândia-MG, foi encaminhado ao Laboratório de Pesquisa em Animais Silvestres (LAPAS), com o objetivo de determinar a topografia do cone medular para tornar possível a realização desta técnica anestésica em um felino silvestre de nossa fauna. Este animal foi fixado em solução de formol a 10%. Feita incisão de pele, os músculos da coluna vertebral foram retirados, os arcos vertebrais foram seccionados para visualização da medula espinhal e seus envoltórios. O cone medular neste animal iniciou-se na sexta vértebra lombar (L6) e terminou na segunda vértebra sacral (S2), com comprimento total de 50mm. O comprimento corporal deste felino foi de 473mm. Conclui-se que o melhor local para a anestesia epidural do membro pélvico no gato mourisco está entre as vértebras L6 e S2. Topographycal study on the medullar cone in jaguarundi, Herpailurus yagouaroundi (Severtzow,1858)(FELIDAE Abstract Since the caudal anesthesia was first proposed in 1926 many techniques were developed to anesthethize the lumbar and sacral nerves. Such methods for epidural anesthesia require knowledge of the relative anatomical regions. The objetive of the present study was to determine the topographic anatomy of the jaguarundi medullar cone as a morphological basis for application of anesthesis techniques. One adult female jaguarondi that perished by natural death has been obtained form the Sabiá Zoo Park, Uberlândia, MG, Brazil and conducted to tha Wild Animals Laboratory. The animal was fixes in 10% formalin solution. Following skin incision, muscles of the vertebral column were removed and the vertebral arcs sectioned for the visualization of hte spinal cord and its wrappers. Epidural anesthesic drug in the medullar cone. The medullar cone in this jaguarundi startet in the sixth lumbar vertebra (L6) and ended in the second sacral vertebra (S2); the spinal cord length was 50mm. The corporal length of this feline measured 473mm. The best region to perform the pelvic anesthesia in a jaguarundi is between the vertebra L6 and S2
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