647 resultados para 892
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The effects of soybean and castorbean meals were evaluated separately, and in combinations at different ratios, as substrates for lipase production by Botryosphaeria ribis EC-01 in submerged fermentation using only distilled water. The addition of glycerol analytical grade (AG) and glycerol crude (CG) to soybean and castorbean meals separately and in combination, were also examined for lipase production. Glycerol-AG increased enzyme production, whereas glycerol-CG decreased it. A 24 factorial design was developed to determine the best concentrations of soybean meal, castorbean meal, glycerol-AG, and KH2PO4 to optimize lipase production by B. ribis EC-01. Soybean meal and glycerol-AG had a significant effect on lipase production, whereas castorbean meal did not. A second treatment (22 factorial design central composite) was developed, and optimal lipase production (4,820 U/g of dry solids content (ds)) was obtained when B. ribis EC-01 was grown on 0.5 % (w/v) soybean meal and 5.2 % (v/v) glycerol in distilled water, which was in agreement with the predicted value (4,892 U/g ds) calculated by the model. The unitary cost of lipase production determined under the optimized conditions developed ranged from US$0.42 to 0.44 based on nutrient costs. The fungal lipase was immobilized onto Celite and showed high thermal stability and was used for transesterification of soybean oil in methanol (1:3) resulting in 36 % of fatty acyl alkyl ester content. The apparent K m and V max were determined and were 1.86 mM and 14.29 μmol min -1 mg-1, respectively. © 2013 Springer Science+Business Media New York.
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This study was conducted with the objective to evaluate the duration of exposure of animals to the evaporative cooling system in the waiting barn on the weather variables (temperature and relative humidity), animal behavior, production and quality aspects of milk from Girolando cows. Sixteen multiparous lactating cows were used having a genetic composition of 7/8 Holstein-Gir and mean milk production of 18 kg animal-1day-1. A 4 × 4 Latin square design was used. The experiment was conducted during the summer season (February-March 2009) and lasted 56 days. The treatments consisted of different periods of 10, 20 and 30 minutes of exposure to acclimatization and control. Time of 30 minutes of exposure to thermal conditioning system enabled the second milking (evening shift), providing an increase in milk production in the next milking of 0.640 kg animal-1. A higher percentage of time spent on food intake and rumination (17.31 and 30.19%) in 30 minutes treatment, compared to control (15.50 and 27.37%), respectively. There was no significant effect of treatments in the composition of milk.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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The acoupa weakfish (Cynoscion acoupa - Sciaenidae) is a marine species of croaker with estuarine-dependent behavior, found in the western Atlantic from Panama to Argentina. It is one of the most exploited food fish on the northern coast of Brazil. In this study, DNA sequences were determined from the entire control region (D-loop) of the mitochondrial genome of 297 individuals collected during seven different months between December 2003 and August 2005 on the northern coast of Brazil (Amapá and Pará). Genetic variability expressed by haplotype (h = 0,892) and nucleotide (p = 0,003) diversities were low compared to other heavily exploited marine fish species from the western Atlantic and eastern Asia. AMOVA depicted a lack of genetic structuring among the samples from different years, indicating the presence of a single stock of C. acoupa within the sample area. The possible reasons for the low levels of genetic diversity are discussed. These results demonstrate a need for the monitoring of C. acoupa harvesting and the preservation of the estuaries within its geographic range, considering that this large fish depends on estuarine ecosystems during part of its life cycle.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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O presente estudo investigou a relação de comunidades de anuros de serapilheira e lagartos com a área basal de árvores, densidade do sub-bosque, cobertura do dossel e profundidade da serapilheira, a fim de verificar se a distribuição dessa comunidade, assim como de algumas espécies analisadas separadamente, seria determinada por estes fatores ambientais. A amostragem ocorreu entre agosto e novembro de 2007, em uma grade de 25 km² implantada pelo Programa de Pesquisa em Biodiversidade (PPBio) / Amazônia, localizada na Floresta Nacional de Caxiuanã, Pará, Brasil. Duas técnicas de amostragem foram utilizadas: procura ativa diurna e armadilhas de interceptação e queda. No total, foram registrados 892 lagartos e anuros, pertencentes a 27 espécies (15 de anuros e 12 de lagartos). Na coleta ativa foram registradas 12 espécies de anuros (101 indivíduos) e 12 de lagartos (171 indivíduos), enquanto que nas armadilhas de interceptação e queda foram 11 espécies de anuros (327 indivíduos) e 15 de lagartos (293 indivíduos). Não houve relação significativa entre a distribuição das comunidades de anuros e lagartos com as variáveis preditoras, indicando que essas espécies ocorrem ao longo de todos os gradientes ambientais estudados. Apenas os lagartos Coleodactylus amazonicus e Ptychoglossus brevifrontalis apresentaram uma relação entre a sua distribuição e a densidade do sub-bosque e profundidade da serapilheira, respectivamente. Espera-se com este estudo contribuir para o aprimoramento do desenho amostral da herpetofauna do PPBio.
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To quantify the effects of methylmercury (MeHg) on amacrine and on ON-bipolar cells in the retina, experiments were performed in MeHg-exposed groups of adult trahiras (Hoplias malabaricus) at two dose levels (2 and 6 µg/g, ip). The retinas of test and control groups were processed by mouse anti-parvalbumin and rabbit anti-aprotein kinase C (aPKC) immunocytochemistry. Morphology and soma location in the inner nuclear layer were used to identify immunoreactive parvalbumin (PV-IR) and aPKC (aPKC-IR) in wholemount preparations. Cell density, topography and isodensity maps were estimated using confocal images. PV-IR was detected in amacrine cells in the inner nuclear layer and in displaced amacrine cells from the ganglion cell layer, and aPKC-IR was detected in ON-bipolar cells. The MeHg-treated group (6 µg/g) showed significant reduction of the ON-bipolar aPKC-IR cell density (mean density = 1306 ± 393 cells/mm2) compared to control (1886 ± 892 cells/mm2; P < 0.001). The mean densities found for amacrine PV-IR cells in MeHg-treated retinas were 1040 ± 56 cells/mm2 (2 µg/g) and 845 ± 82 cells/mm2 (6 µg/g), also lower than control (1312 ± 31 cells/mm2; P < 0.05), differently from the data observed in displaced PV-IR amacrine cells. These results show that MeHg changed the PV-IR amacrine cell density in a dose-dependent way, and reduced the density of aKC-IR bipolar cells at the dose of 6 µg/g. Further studies are needed to identify the physiological impact of these findings on visual function.
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The objective of this work was to evaluate the inter-relationship between dietary supplementation with Saccharomyces cerevisiae cell wall and vaccination against Streptococcus agalactiae, and its effect on the productive performance and hematological variables of Nile tilapia (Oreochromis niloticus). Eighty-four Nile tilapia were distributed in 12 fiber boxes (n=7), in a 2x2x3 factorial arrangement, corresponding to two levels of supplementation with yeast cell wall, two types of inoculation, and three evaluation times. Fish were fed during 77 days. Vaccination of fish was done 60 days after feeding started. Fifteen days after vaccination, all fish were subjected to challenge with live strain of S. agalactiae, and 6, 24, and 48 hours after the challenge, blood was collected from the caudal vein for evaluations. Fish fed with supplemented diets show greater weight gain and specific growth rate, and the interaction between the diet and vaccination effects results in higher hematocrit, hemoglobin, and leukocyte rates.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Since the 1950s, fatigue is the most important project and operational consideration for both civil and military aircrafts. For some aircraft models the most loaded component is one that supports the motor: the Motor Cradle. Because they are considered critical to the flight safety the aeronautic standards are extremely rigorous in manufacturing them by imposing a zero index of defects on the final weld quality (Safe Life), which is 100% inspected by Non-Destructive Testing/NDT. This study has as objective to evaluate the effects of up to four successive TIG welding repairs on the axial fatigue strength of an AISI 4130 steel. Tests were conducted on hot-rolled steel plate specimens, 0.89 mm thick, with load ratio R = 0.1, constant amplitude, at 20 Hz frequency and in room temperature, in accordance with ASTM E466 Standard. The results were related to microhardness and microstructural and geometric changes resulting from welding cycles.