1000 resultados para Choque eletrico


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O objetivo deste trabalho foi avaliar o efeito do choque térmico e mecânico na produtividade de Lentinula edodes em 140 toras de Eucalyptus saligna, completamente colonizadas pelo fungo, em diferentes tempos de imersão em água e no primeiro fluxo de produção. As toras foram imersas em água resfriada (16ºC) ou à temperatura ambiente (22ºC); os períodos de imersão corresponderam a 6, 10, 14, 18, 22, 26 e 38 horas; o choque mecânico foi acompanhado por três quedas consecutivas da tora, em posição vertical, no chão. A temperatura da água e o tempo de imersão afetaram a produção de L. edodes, resultando em aumentos significativos (2 a 4 vezes) nos tratamentos em que as toras foram submetidas à água resfriada e nos tempos de imersão mais curtos (6 e 10 horas). O choque mecânico não resultou em aumento na produção de basidiomas.

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Foram examinados 20 eqüinos adultos portadores de abdômen agudo e submetidos à laparotomia. Dez recuperaram-se sem intercorrência pós-operatória (G1) e 10 foram a óbito sete a 10 dias após a cirurgia, com sinais de choque séptico (G2). Avaliaram-se temperatura retal, freqüências cardíaca e respiratória, tempo de preenchimento capilar e teores plasmáticos das proteínas de fase aguda - fibrinogênio, ceruloplasmina, proteína C-reativa, antitripsina, haptoglobina e glicoproteína ácida -, antes e até sete dias após a laparotomia. As leucometrias às 72h e no sétimo dia pós-operatório dos eqüinos que foram a óbito foram, respectivamente, 34,6% e 57,1%, mais altas que a dos animais curados. Os maiores valores de proteína de fase aguda ocorreram no sétimo dia após a cirurgia; os percentuais de elevação de fibrinogênio, antitripsina, glicoproteina ácida, proteína C-reativa, ceruloplasmina e haptoglobina de eqüinos do G2 em relação ao G1 foram 46,8%, 67,9%, 91,9%, 112,2%, 126,9% e 186,2%, respectivamente.

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Dormancy is an inherent property of the seeds that define the environmental conditions in which they are able to germinate and their presence is an adaptive trait common in species inhabiting semiarid regions. Moreover, the ability of seedling establishment in these environments has been related to the size, strength and chemical characteristics of the seeds. This study investigated patterns of dormancy and germination speed in tree species of the Caatinga, exploring how the seed size influence the processes of germination, seedling size and biomass allocation. In addition, we aim to investigate the chemical characteristics of the reserves, to verify a possible relationship between nutritional content and the process of seed germination. Therefore, seeds were collected from ten species of woody Caatinga for tests of breaking dormancy, germination and biochemical characterization. Overall, the results show that the scarification treatments mechanical and chemical, and thermal shock influenced the percentage and speed of germination in 50 % of the species, suggesting that they have some level of physical dormancy in the seeds. Biochemical characterization showed the existence of large amounts of carbohydrates in the seeds of all species, low proportion of protein and low amounts of neutral lipids. Using linear regression, we demonstrated the existence of a significant relationship between seed size and the ratio of root/shoot where the largest seeds invested a greater amount of resources for shoot growth. The relationship between germination speed and non-reducing sugar content was also significant, so these compounds is related to the maintenance of physiological seed quality. These results confirm some relationships discussed in the literature for cultivated species, but can be applied to the species native to the Caatinga

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This study aims to verify the impact of the Bolsa Família Program (BFP) in income and school attendance of poor Brazilian families. It is intended to also check the existence of a possible negative effect of the program on the labor market, titled as sloth effect. For such, microdata from the IBGE Census sample in 2010 were used. Seeking to purge possible selection biases, methodology of Quantilic Treatment Effect (QTE) was applied, in particular the estimator proposed by Firpo (2007), which assumes an exogenous and non-conditional treatment. Moreover, Foster- Greer-Thorbecke (FGT) index was calculated to check if there are fewer households below the poverty line, as well as if the inequality among the poor decreases. Human Opportunity Index (HOI) was also calculated to measure the access of young people / children education. Results showed that BFP has positively influenced the family per capita income and education (number of children aged 5-17 years old attending school). As for the labor market (worked hours and labor income), the program showed a negative effect. Thus, when compared with not benefiting families, those families who receive the BFP have: a) a higher family income (due to the shock of the transfer budget money) b) more children attending school (due to the conditionality imposed by the program); c) less worked hours (due to sloth effect in certain family groups) and d) a lower income from work. All these effects were potentiated separating the sample in the five Brazilian regions, being observed that the BFP strongly influenced the Northeast, showing a greater decrease in income inequality and poverty, and at the same time, achieved a greater negative impact on the labor market

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This work arose from our concerns with the issues of teacher training for early childhood education. From the difficulties encountered as a novice teacher in elementary, we deem important to research training needs of these professionals. Thus, we define the objective of this research to investigate the training needs of novice teachers teaching Early Childhood Education/Elementary school. Our work fits in Educational Research Qualitative Approach, and its construction procedures of the semistructured interview data and document analysis. Our empirical field was made up of schools in the metropolitan region of Natal / RN, offering kindergarten / elementary school. The subjects are five teachers who act as holder of the elementary school class and have 0-3 years of teaching practice, characterizing the second Huberman (2007) as novice teachers. Data analysis, based on principles of content analysis, three themes emerged: Beginner Teaching Professor in Early Childhood Education / Preschool; Reasons explaining the difficulties Faculty / Formative Needs Teaching and Training in Early Childhood Education / Elementary school, from the Training Needs Analysis, with their respective categories, subcategories, contributing to our understanding of the subject matter. The entry into the profession is marked by mixed feelings of euphoria and fear, where there seems to be a "clash" with reality. The difficulties are related to the planning / execution of activities, meet the individual needs of learning and assessment of children. As a strategy to overcome the difficulties the teachers exercise the action-reflection-action in their practices and seek continuous updates in the theoretical and methodological framework of early childhood education. The reasons that define these difficulties may be related to the teacher, school, family, and students of these institutions. In experiencing these difficulties has outlined the need for teacher training, among which stand out studies on ethics in teaching with children, the concept of children and their childhoods, peculiarities of teaching / learning in preschool, toys and legal determinations on early childhood education, multi-language and expressions in early childhood education, specific content areas of knowledge, among others. Furthermore, studies on the theoretical as Piaget, Vigotsky, Maria Carmen Barbosa and Emily Smith. For these professionals to be a professional early childhood education is: like children, be patient and careful, have specific theoretical and practical training for teachers in kindergarten, being able to improvise with seriousness and competence and get updates on continuing education. The surveys, together with the authors and teachers, to confirm our understanding that the training needs of beginners may be related to shortcomings in the initial and continuing education

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This work arose from our concerns with the issues of teacher training for early childhood education. From the difficulties encountered as a novice teacher in elementary, we deem important to research training needs of these professionals. Thus, we define the objective of this research to investigate the training needs of novice teachers teaching Early Childhood Education/Elementary school. Our work fits in Educational Research Qualitative Approach, and its construction procedures of the semistructured interview data and document analysis. Our empirical field was made up of schools in the metropolitan region of Natal / RN, offering kindergarten / elementary school. The subjects are five teachers who act as holder of the elementary school class and have 0-3 years of teaching practice, characterizing the second Huberman (2007) as novice teachers. Data analysis, based on principles of content analysis, three themes emerged: Beginner Teaching Professor in Early Childhood Education / Preschool; Reasons explaining the difficulties Faculty / Formative Needs Teaching and Training in Early Childhood Education / Elementary school, from the Training Needs Analysis, with their respective categories, subcategories, contributing to our understanding of the subject matter. The entry into the profession is marked by mixed feelings of euphoria and fear, where there seems to be a "clash" with reality. The difficulties are related to the planning / execution of activities, meet the individual needs of learning and assessment of children. As a strategy to overcome the difficulties the teachers exercise the action-reflection-action in their practices and seek continuous updates in the theoretical and methodological framework of early childhood education. The reasons that define these difficulties may be related to the teacher, school, family, and students of these institutions. In experiencing these difficulties has outlined the need for teacher training, among which stand out studies on ethics in teaching with children, the concept of children and their childhoods, peculiarities of teaching / learning in preschool, toys and legal determinations on early childhood education, multi-language and expressions in early childhood education, specific content areas of knowledge, among others. Furthermore, studies on the theoretical as Piaget, Vigotsky, Maria Carmen Barbosa and Emily Smith. For these professionals to be a professional early childhood education is: like children, be patient and careful, have specific theoretical and practical training for teachers in kindergarten, being able to improvise with seriousness and competence and get updates on continuing education. The surveys, together with the authors and teachers, to confirm our understanding that the training needs of beginners may be related to shortcomings in the initial and continuing education

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Este trabalho foi desenvolvido com o objetivo de pesquisar o efeito da energia da dieta sobre a temperatura do cólon e concentração de proteína de choque térmico (Hsp70) de frangos à temperatura ambiente, bem como durante o estresse calórico agudo. Os frangos foram criados até 51 dias de idade e alimentados com dietas contendo nível de energia alto (13.186 kJ EM/kg) ou baixo (12.139 kJ EM/kg). No 21º e 51º dias de idade, a temperatura do cólon foi medida e amostras de fígado foram obtidas para quantificação da Hsp70 através da análise por Western Blotting.. Nessas mesmas idades, a resposta das aves ao estresse calórico agudo (37º C/5 h) foi avaliada (temperatura colón e Hsp70 no fígado). Os resultados mostraram que aos 21 dias de idade, à temperatura ambiente, a temperatura do cólon e a concentração de Hsp70 hepática não foram afetadas pela energia da dieta, mas, aos 51 dias de idade, os frangos alimentados com baixos teores de energia apresentaram menores concentrações de Hsp70 no fígado. As respostas ao estresse calórico agudo mostraram que as aves alimentadas com dietas de alta energia tiveram menor incremento na temperatura do cólon, bem como no conteúdo de Hsp70 hepático. Os resultados desse estudo sugerem que a síntese de Hsp70 no fígado pode ser afetada pela energia da dieta e que frangos alimentados com altos níveis de energia podem ter a termotolerância alterada em condições de estresse agudo pelo calor.

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Com o objetivo de se avaliar o comportamento fisiológico das aves, bem como, se ocorre a expressão da proteína do choque térmico (Hsp 70) no fígado e cérebro, como conseqüência da exposição ao estresse por calor, em quatro dias sucessivos (2 a 5 dias de vida), 20 pintos de corte de duas linhagens Pescoço pelado (Na/na) e Hubbard-Petersen, foram ou não estressados à temperatura de 36-37°C, durante cinco horas. Foram colhidas amostras de fígado e cérebro, ao final do período de estresse, e analisadas por Western Blotting, para determinação dos níveis de Hsp 70. Os resultados não mostraram associação entre perda de peso corporal e as demais características. Aumentos da variação de temperatura cloacal apresentaram aumentos nos níveis de Hsp70 no tecido hepático e cerebral. Concluiu-se que a concentração de Hsp70 no cérebro, apresentou-se correlacionada com a variação de temperatura cloacal, quando se usou o condicionamento ao calor em pintos de corte, embora não se possa afirmar que seria indicativo de termotolerância de aves.

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Porous ceramics have many applications: thermal insulation, catalytic support, materials to fire protection, filters, and others. There are many techniques to production of ceramic filters. One technique to obtain ceramic filters is the replication method. This method consists in the impregnation of polymeric foam with ceramic slurry followed by a heating treatment that will burn out the organic elements and sintering of the material, resulting of a replication of the original foam. To perform their functions ceramic filters must satisfy mechanical requirements and permeability parameters (darcian k1 and no-darcian k2). The permeability and the strength of the ceramic material are dependent of the pore size and pore distribution. To the use at high temperatures the evaluation of mechanical properties in these temperatures is necessary. In this work the mechanical behavior of two commercial porous ceramics (10 and 40 poros per inch) was studied these materials were submitted to compression and four-point flexure test (room temperature, at 1000 °C, after thermal shock). Density and porosity measurements, permeability tests and microstructural analysis by scanning electronic microscopy (SEM) were realized. The Results showed that the decrease of mechanical strength of these materials, when submitted to thermal shock, occur for propagation of new cracks from cracks pre-existing and the permeability depends of the pore size

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The segment of the structural ceramics industry is one of the most important to the economy of Rio Grande do Norte. The supply chain makes a total of 206 companies that are distributed in 39 counties, concentrated in three regional centers: Seridó Apodi / Assu and great Natal. The ceramic industry in the state is around 80 million pieces per month, with 50,186 million of these tiles, which makes the Rio Grande do Norte one of the largest manufacturers of product in the Country. Different ceramic products can be manufactured by mixing two or more clays and accessory minerals. Mixtures acquire characteristics and form what is called the ceramic body. Refractory masses have a high melting point and thermal shock support. Its composition contains refractory clays with a little iron oxide and material fluxes. A line of semi-refractory ceramic products that stands out for its high added value are the bricks in ivory or red, used in building barbecues, fireplaces, wood stoves and braziers. The aim of this study was to use alumina-clay or silica- alumina-clay to the industrial RN, for the production of refractory bricks semi-refractory burning light. Clay and Kaolin were characterized for their chemical and mineralogical composition, immediately after ceramic bodies were made with different concentrations of the components, they were raised, pressed and sintered. After sintering the resulting products were characterized in terms of mechanical, thermal and dimensional than the characterization by X-ray diffraction and scanning electron microscopy. After obtaining the results, we concluded that the studied clay can be used for the production of semi-refractory bricks

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Universidade Federal do Rio Grande do Norte

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

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O envelhecimento pode estar associado ao maior acúmulo de lesões celulares decorrentes das espécies reativas do oxigênio e do nitrogênio derivadas do metabolismo mitocondrial. Com a progressão da idade, há acúmulo de proteínas, lipídeos, carboidratos e DNA oxidados em relação a organismos jovens, de acordo com a teoria dos radicais livres. Entretanto, nem sempre os idosos ou animais envelhecidos apresentam maior estresse oxidativo que os jovens. Este artigo discute o paradoxo da teoria dos radicais livres de acordo com a teoria da biogênese da manutenção adequada do metabolismo mitocondrial. Diversos fatores podem contribuir para a redução do estresse oxidativo, como a hormese induzida pela prática regular de exercícios físicos, a restrição calórica, a ingestão de antioxidantes nutricionais e o aumento da produção de antioxidantes celulares que. em conjunto, estes promovem a expressão das sirtuínas e das proteínas do choque térmico, protegendo a integridade e funcionalidade mitocondriais, reduzindo o estresse oxidativo e nitrosativo, o que está associado à redução do envelhecimento e aumento da longevidade.

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We use a finite diference eulerian numerical code, called ZEUS 3D, to do simulations involving the collision between two magnetized molecular clouds, aiming to evaluate the rate of star formation triggered by the collision and to analyse how that rate varies depending on the relative orientations between the cloud magnetic fields before the shock. The ZEUS 3D code is not an easy code to handle. We had to create two subroutines, one to study the cloud-cloud collision and the other for the data output. ZEUS is a modular code. Its hierarchical way of working is explained as well as the way our subroutines work. We adopt two sets of different initial values for density, temperature and magnetic field of the clouds and of the external medium in order to study the collision between two molecular clouds. For each set, we analyse in detail six cases with different directions and orientations of the cloud magnetic field relative to direction of motion of the clouds. The analysis of these twelve cases allowed us to conform analytical-theoretical proposals found in the literature, and to obtain several original results. Previous works indicate that, if the cloud magnetic fields before the collision are orthogonal to the direction of motion, then a strong inhibition of star formation will occur during a cloud-cloud shock, whereas if those magnetic fields are parallel to the direction of motion, star formation will be stimulated. Our treatment of the problem confirmed numerically those results, and further allowed us to quantify the relative star forming efficiencies in each case. Moreover, we propose and analyse an intermediate case where the field of one of the clouds is orthogonal to the motion and the field of the other one is parallel to the motion. We conclude that, in this case, the rate at which the star formation occurs has a value also intermediate between the two extreme cases we mentioned above. Besides that we study the case in which the fields are orthogonal to the direction of the motion but, instead of being parallel to each other, they are anti-parallel, and we obtained for this case the corresponding variation of the star formation rate due to this alteration of the field configuration. This last case has not been studied in the literature before. Our study allows us to obtain, from the simulations, the rate of star formation in each case, as well as the temporal dependence of that rate as each collision evolves, what we do in detail for one of the cases in particular. The values we obtain for the rate of star formation are in accordance with those expected from the presently existing observational data