911 resultados para IRRADIATED GROUND-BEEF


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Presents a composite formed by orthophthalic resin and fiber loading of carnauba straw. The fibers were first dried in direct sun exposure and subsequently ground into fodder for the reduction in size. Various formulations of the composite were preliminarily tested by choosing the one presenting the best processability in applying the mold. The composite produced is used for the manufacture of a parabolic surface subsequently coated with mirror segments, flexible plastic, for reflecting the solar rays incident on it. The reflective parable represents the main element of the solar cooker that works with the concentration of sunlight and has dimensions of 1.14 m in diameter and area of 1.0 m². Manufacturing processes and assembly of solar cooker concentration produced are presented. The results of tests for cooking and baking various foods, including rice, pasta, beans, cake, cassava, shrimp, beef, breaded demonstrating the competitiveness of solar cooker studied with other stoves already manufactured and tested in Brazil are presented and in the world. It was also demonstrated the feasibility of the proposed composite for Prototypes manufacture of solar and other structures that do not require great efforts resistance

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Desde os descobrimentos pioneiros de Hubel e Wiesel acumulou-se uma vasta literatura descrevendo as respostas neuronais do córtex visual primário (V1) a diferentes estímulos visuais. Estes estímulos consistem principalmente em barras em movimento, pontos ou grades, que são úteis para explorar as respostas dentro do campo receptivo clássico (CRF do inglês classical receptive field) a características básicas dos estímulos visuais como a orientação, direção de movimento, contraste, entre outras. Entretanto, nas últimas duas décadas, tornou-se cada vez mais evidente que a atividade de neurônios em V1 pode ser modulada por estímulos fora do CRF. Desta forma, áreas visuais primárias poderiam estar envolvidas em funções visuais mais complexas como, por exemplo, a separação de um objeto ou figura do seu fundo (segregação figura-fundo) e assume-se que as conexões intrínsecas de longo alcance em V1, assim como as conexões de áreas visuais superiores, estão ativamente envolvidas neste processo. Sua possível função foi inferida a partir da análise das variações das respostas induzidas por um estímulo localizado fora do CRF de neurônios individuais. Mesmo sendo muito provável que estas conexões tenham também um impacto tanto na atividade conjunta de neurônios envolvidos no processamento da figura quanto no potencial de campo, estas questões permanecem pouco estudadas. Visando examinar a modulação do contexto visual nessas atividades, coletamos potenciais de ação e potenciais de campo em paralelo de até 48 eletrodos implantados na área visual primária de gatos anestesiados. Estimulamos com grades compostas e cenas naturais, focando-nos na atividade de neurônios cujo CRF estava situado na figura. Da mesma forma, visando examinar a influência das conexões laterais, o sinal proveniente da área visual isotópica e contralateral foi removido através da desativação reversível por resfriamento. Fizemos isso devido a: i) as conexões laterais intrínsecas não podem ser facilmente manipuladas sem afetar diretamente os sinais que estão sendo medidos, ii) as conexões inter-hemisféricas compartilham as principais características anatômicas com a rede lateral intrínseca e podem ser vistas como uma continuação funcional das mesmas entre os dois hemisférios e iii) o resfriamento desativa as conexões de forma causal e reversível, silenciando temporariamente seu sinal, permitindo conclusões diretas a respeito da sua contribuição. Nossos resultados demonstram que o mecanismo de segmentação figurafundo se reflete nas taxas de disparo de neurônios individuais, assim como na potência do potencial de campo e na relação entre sua fase e os padrões de disparo produzidos pela população. Além disso, as conexões laterais inter-hemisféricas modulam estas variáveis dependendo da estimulação feita fora do CRF. Observamos também uma influência deste circuito lateral na coerência entre potenciais de campo entre eletrodos distantes. Em conclusão, nossos resultados dão suporte à ideia de um mecanismo complexo de segmentação figura-fundo atuando desde as áreas visuais primárias em diferentes escalas de frequência. Esse mecanismo parece envolver grupos de neurônios ativos sincronicamente e dependentes da fase do potencial de campo. Nossos resultados também são compatíveis com a hipótese que conexões laterais de longo alcance também fazem parte deste mecanismo

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Over the last three decades, researchers have responded to the demands of industry to manufacture mechanical components with geometrical tolerance, dimensional tolerance, and surface finishing in nanometer levels. The new lapgrinding process developed in Brazil utilizes lapping kinematics and a flat grinding wheel dressed with a single-point diamond dresser in agreement with overlap factor (U(d)) theory. In the present work, the influences of different U(d) values on dressing (U(d) = 1, 3 e 5) and grain size of the grinding wheel made of silicon carbide (SiC = 800, 600 e 300 mesh) are analyzed on surface finishing of stainless steel AISI 420 flat workpieces submitted to the lapgrinding process. The best results, obtained after 10 minutes of machining, were: average surface roughness (Ra) 1.92 nm; 1.19 mu m flatness deviation of 25.4 mm diameter workpieces and mirrored surface finishing. Given the surface quality achieved, the lapgrinding process can be included among the ultra-precision finishing processes and, depending on the application, the steps of lapping followed by polishing can be replaced by the proposed abrasive process.

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This work analyses the waveshapes of continuing currents and parameters of M-components in positive cloud-to-ground (CG) flashes through high-speed GPS synchronized videos. The dataset is composed of only long continuing currents (with duration longer than 40 ms) and was selected from more than 800 flashes recorded in Sao Jose dos Campos (45.864 degrees W, 23.215 degrees S) and Uruguaiana (29.806 degrees W, 57.005 degrees S) in Southeast and South of Brazil, respectively, during 2003 to 2007 summers. The videos are compared with data obtained by the Brazilian Lightning Location System (BrasilDAT) in order to determine the polarity of each flash and select only positive cases. There are only two studies of waveshapes of continuing currents in the literature. One is based on direct current measurements of triggered lightning, in which four different types of waveshapes were observed; and the other is based on measurements of luminosity variations in high-speed videos of CG negative lightning, in which besides the four types above mentioned two additional types were observed. The present work is an extension of the latter, using the same method but now applied to obtain the waveshapes of positive CG lightning. As far as the authors know, this is the first report on M-components in positive continuing currents. We also have used the luminosity-versus-time graphs to observe their occurrence and measure some parameters (duration, elapsed time and time between two successive M-components), whose statistics are presented and compared in detail to the data for negative flashes. We have plotted a histogram of the M-components elapsed time over the total duration of the continuing current for positive flashes, which presented an exponential decay (correlation coefficient: 0.83), similar to what has been observed for negative flashes. (C) 2008 Elsevier B.V. All rights reserved.

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The thermoluminescence (TL) response of Dy and Li doped 20CaB(4)O(7)-80CaB(2)O(4) (Wt%) glass-ceramic irradiated with ultraviolet (UV) radiation was studied. In order to act as TL activator ions, the Dy and Li ions were included in the matrix during the melting process to increase its TL efficiency. A single crystalline CaB2O4 phase was present in the glass-ceramic as determined by X-ray diffraction (XRD). The glass-ceramic 20CaB(4)O(7)-80CaB(2)O(4):Dy,Li wt% (named 20CBO7:Dy,Li) is a newly prepared TL material. Its thermoluminescent dosimetric characteristics have shown a linear response under UV radiation exposure and a good TL signal reproducibility, thus proving to be a promising material for using as an ultraviolet radiation dosimeter. (C) 2007 Elsevier B.V. All rights reserved.

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Natural (NV) and Cobalto60-irradiated (IrV) Crotalus durissus terrificus venom were used to evaluate serum production capacity of sheep and possible hematological and biochemical effects. Freeze-dried venom aliquots were diluted in acidified saline solution (NaCl 150 mM, pH 3.0) and irradiated by a Cobalt 60 source at a dose of 5.54 x 102 Gy/h and a concentration of 2.000 Gy. Twelve sheep were divided into two groups of six animals. One group received irradiated venom (IrV) and the other natural venom (NV). Three antigen doses (venom) were administered at monthly intervals. Blood samples were collected weekly for analysis of serum neutralization potency and capacity, complete blood count (CBC), total plasma protein, fibrinogen, albumin, and globulin. At the end of the experiment, the animals were challenged with a LD50 for sheep and showed no signs of envenoming. The two groups did not present clinical alterations. Results of the total leukocyte count did not present interaction or time factor effect for both groups, but there was a different action between them, with the NV group presenting more cells than the IrV group. The leukocyte increase to 13,000/ml indicates that slight leukocytosis occurred in the week after the first inoculation in the NV group. There was no statistically significant difference between groups in the absolute count of segmented neutrophils, eosinophils, and lymphocytes but there were statistically significant oscillations in values at the different collecting times. The NV group presented an increase in the absolute neutrophil count after the first inoculation that persisted for 5 weeks. In the IrV group, the increase in neutrophils occurred only in the first week returning to normal in the following weeks. The alterations in the neutrophil count are indicative of systemic inflammatory response related to cytokine release; response was more marked in the NV group, showing its greater toxicity.

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The growth hormone receptor (GHR) is the cell surface receptor for growth hormone (GH) and is required for GH to carry out its effects on target tissues. The objectives of the present study were to estimate the allele and genotype frequencies of the GHR/Alu I gene polymorphism located in the regulatory region in beef cattle belonging to different genetic groups and to determine associations between this polymorphism and growth and carcass traits. Genotyping was performed on 384 animals, including 79 Nellore (Zebu), 30 Canchim (5/8 Charolais+3/8 Zebu), 30 Simmental X Nellore crossbred and 245 Angus x Nellore crossbred cattle. Alleles Alu I(+), Alu I(-) and Alu I(N)-null allele-were evidenced for the GHR/Alu I polymorphism and the frequency of the Alu I(N) allele was significantly higher than the frequency of the Alu I(+) and Alu I(-) alleles in all genetic groups. Genotype Alu I(N/N) of the GHRIAlu I predominated in Nellore animals, while the Alu I(N/+) and Alu I(N/-) predominated in the other genetic groups. In the association studies, traits of interest were analyzed using the General Linear Model (GLM) procedure of the SAS program and least squares means of the genotypes were compared by the Tukey test. Significant associations (P < 0.05) were observed between the Alu I(N/N) genotype of the GHRIAlu I polymorphism and lower weight gain and body weight at slaughter, although a confounding between genotypes and genetic groups may have occurred. (c) 2005 Elsevier B.V. All rights reserved.

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Growth hormone (GH), insulin-like growth factors 1 and 2 (IGF1 and IGF2) and their associated binding proteins and transmembrane receptors (GHR, IGF1R and IGF2R) play an important role in the physiology of mammalian growth. The objectives of the present study were to estimate the allele and genotype frequencies of microsatellite markers located in the 5'-regulatory region of the IGF1 and GHR genes in beef cattle belonging to different genetic groups and to determine effects of these markers on growth and carcass traits in these animals under an intensive production system. For this purpose, genotyping was performed on 384 bulls including 79 Nellore, 30 Canchim (5/8 Charolais + 3/8 Zebu) and 275 crossbred animals originating from crosses of Simmental (1/2 Simmental, n = 30) and Angus (1/2 Angus, n = 245) sires with Nellore females. The effects of substituting L allele for S allele of GHR microsatellite across Nellore, Canchim and 1/2 Angus were significant for weight gain and body weight (P < 0.05). The IGF1 microsatellite allele substitutions of 229 for 225 within Nellore group and of 225 for 229 within 1/2 Angus were not significant for any of the traits.

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Molecular biology techniques are of help in genetic improvement since they permit the identification, mapping and analysis of polymorphisms of genes encoding proteins that act on metabolic pathways involved in economically interesting traits. The somatotrophic axis, which essentially consists of growth hormone releasing hormone (GHRH), growth hormone (GH), insulin-like growth factors I and II (IGF-I and IGF-II), and their associated binding proteins and receptors (GHRHR, GHR, IGF-IR and IGF-IIR), plays a key role in the metabolism and physiology of mammalian growth. The objectives of the present study were to estimate the allele and genotype frequencies of the IGF-I/SnaBI, IGF-IR/TaqI and GHRH/HaeIII gene polymorphisms in different genetic groups of beef cattle and to determine associations between these polymorphisms and growth and carcass traits. For this purpose, genotyping was performed on 79 Nellore animals, 30 Canchim (5/8 Charolais+3/8 Zebu) animals and 275 crossbred cattle originating from the crosses of Simmental (n=30) and Angus (n=245) sires with Nellore females. In the association studies, traits of interest were analyzed using the GLM procedure of SAS and least square means of the genotypes were compared by the Tukey test. Associations of IGF-I/SnaBI genotypes with body weight and subcutaneous backfat were significant (p < 0.05), and nearly significant for longissimus dorsi area (p=0.06), with the 1313 genotype being favorable compared to the AB genotype. No significant associations were observed between this polymorphism and weight gain or carcass yield (P > 0.05). The IGF-IR/TaqI and GHRH/HaeIII polymorphisms showed no association with production traits. (c) 2004 Elsevier B.V All rights reserved.

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