403 resultados para 1214
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Incluye Bibliografía
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A esquistossomose é uma doença tropical causada, principalmente, pelo trematódeo Schistosoma mansoni, sendo que sua ocorrência afeta, mundialmente, 110 milhões de pessoas. A deposição dos ovos do parasita pode ocorrer, de forma ectópica, no sistema nervoso central (SNC) o qual leva à formação de granulomas com consequente produção do Fator de Crescimento Neuronal (NGF). Uma vez que muitos estudos demonstram a importância do NGF no desenvolvimento das vias corticais visuais, nosso estudo visou avaliar a possível alteração dos níveis de NGF no sistema visual assim como o impacto deste sobre a morfologia de células piramidais em dois modelos animais. A alteração na concentração do fator de crescimento assim como a morfometria neuronal foram avaliadas em animais permissíveis (camundongos) e não permissíveis (ratos) à infecção. Foram utilizados 174 ratos (Hooded Lister) e 135 camundongos albinos criados e mantidos em gaiolas e alimentados ad libitum. Esses animais foram inoculados, logo após o nascimento, com 50 cercárias. Setenta e sete ratos e 73 camundongos foram inoculados com solução salina e constituíram o grupo controle do estudo. Os períodos de infecção abrangeram uma a 48 semanas. Amostras do fígado e córtex visual foram retiradas, extraídas e quantificadas com kit de imunoensaio (ChemiKineTM Nerve Growth Factor (NGF) Sandwich ELISA Kit – Chemicon International). Para a análise morfométrica utilizamos células piramidais da camada IV do córtex visual marcadas através de injeção extracelular com Dextrana-Biotinilada (10.000 kDa). Os resultados foram expressos como média ± desvio padrão. Utilizamos teste t de Student para determinar diferenças estatísticas entre os grupos estudados. O valor médio de NGF encontrado no córtex visual de ratos infectados foi 39,2% maior do que no grupo controle (infectados: 400,9 ± 143,1 pg/mL; controle: 288 ± 31,9 pg/mL; p < 0,0001). Nas amostras de fígado, o aumento foi 28,9% maior no grupo infectado (infectados: 340,9 ± 103,9 pg/mL; p < 0,01; controle: 264,4 ± 38,6 pg/mL). Nenhum aumento significativo foi detectado antes de uma semana de infecção. Entre os camundongos, o aumento de NGF na área visual foi de 94,1% (infectados: 478,4 ± 284 pg/mL; p < 0,01; controle: 246,5 ± 76,8 pg/mL). No fígado destes animais o aumento foi de 138,7% (infectados: 561,8 ± 260,7 pg/mL; p < 0,01; controle: 301,3 ± 134,6 pg/mL). Em camundongos encontramos diferenças significativas quanto aos parâmetros dendríticos avaliados. A quantidade de dendritos foi 11,41% maior no grupo infectado do que no controle (controle: 25,28 ± 5,19; infectados: 28,16 ± 7,45; p < 0,05). O comprimento total dos dendritos também foi afetado (controle: 4.916,52 ± 1.492,65 μm; infectados: 5.460,40 ± 1.214,07 μm; p < 0,05) correspondendo a um aumento de 11,06%. A área total do campo receptor dendrítico sofreu um aumento de 12,99% (controle: 29.346,69 ± 11.298,62 μm2; infectados: 33.158,20 ± 7.758,31; p < 0,05) enquanto que a área somática teve uma redução de 13,61% (controle: 119,38 ± 19,68 μm2; infectados: 103,13 ± 24,69 μm2; p < 0,001). Quando foram avaliados os efeitos do aumento de NGF em ratos infectados não observamos diferenças significativas quanto aos parâmetros dendríticos analisados, em comparação ao grupo controle, com exceção de um aumento na área do corpo neuronal da ordem de 21,18% (controle: 132,20 ± 28,46 μm2; infectados: 160,20 ± 31,63 μm2; p < 0,00001). Este trabalho mostrou que a reação de produção de NGF no SNC durante a infecção por Schistosoma mansoni ocorre em maior magnitude no modelo permissível do que no modelo não permissível. Também demonstramos que, em camundongos, os efeitos sobre a morfologia neuronal é drasticamente afetada quando o organismo é submetido a um aumento na concentração de NGF em decorrência da infecção por Schistosoma mansoni. Diante destes dados, estudos avaliando as possíveis repercussões visuais e também dos efeitos na fisiologia celular causados pela infecção mansônica torna-se necessário para avaliar o real dano causado por este aumento patológico do fator de crescimento neuronal nas vias visuais de mamíferos.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fruit quality is the result of the action of several factors, in particular the individual and combined effect of mineral nutrients. The proper evaluation of mineral nutritional requirements causes that fruit plants can express all their genetic potential. Thus, a research has been conducted in tropical fruit, for evaluating the influence of mineral nutrients on fruit quality; however, they appear dispersed. The objective of this review was to compile and report the effects of mineral nutrients on fruit quality of guava, mango, banana and papaya. Consequently, information about the influence of the essential elements in color, flavor, shape, size, appearance, penetration resistance, physiological disturbs disease incidence, physicochemical characteristics and lifetime of post - harvest fruit are presented.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Y chromosome markers have been widely studied due to their various applications in the fields of forensic and evolutionary genetics. In this study, 35 Y-SNPs and 17 Y-STRs were genotyped in 253 males from the State of Espirito Santo, Brazil. A total of 18 haplogroups and 243 haplotypes were detected; the haplogroup and haplotype diversities were 0.7794 and 0.9997, respectively. Genetic distance analysis using the Y-STR data showed no statistically significant differences between Espirito Santo and other admixed populations from Brazil. The classification of paternal lineages based on haplogroups showed a predominant European contribution (85.88 %), followed by African (11.37 %) and Amerindian (2.75 %) contributions.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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This article aims to list the studies on environmental training published in the Scopus and Web of Science databases, to emphasize the publications most relevant according to the number of citations in other research, list the most prominent authors regarding the topic, the contexts studied and the researcher’s countries of origin. The concepts of environmental management and environmental training were reviewed. The systematic literature review is presented as the methodology, which has as its results the identification of the most influential papers studied in the area, the countries of origin of researchers and the relation between context and origin of the researcher, concluding that Brazil stands out in the study of the theme. That there is a small number of researchers studying different contexts in their country of origin and that partnership between researchers from different countries are required for studies in the area. The study presents as a limitation the still restricted access to some journals presenting articles on the topic, making it impossible to analyze them. It contributes with researchers and those responsible for human resource managers in organizations because it shows the most relevant studies of the area in a compiled form.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Let me begin today by offering my congratulations to each of you who is a member of this new LEAD class. You are embarking upon a truly exciting, rewarding opportunity, important to both you and Nebraska. Our state needs good leaders, people dedicated to keeping our organizations, communities, and Nebraska strong, and moving forward. We need leaders of courage and compassion, able to think clearly, assess information, formulate a plan, and adjust that plan as needed. We need leaders who work toward a common good.
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Coagulation factor VIII (FVIII) concentrates are used in the treatment of patients with Hemophilia A. Human FVIII was purified directly from plasma using anion exchange chromatography followed by gel filtration. Three Q-Sepharose resins were tested, resulting in 40% recovery of FVIII activity using Q-Sepharose XL resin, about 80% using Q-Sepharose Fast Flow and 70% using the Q-Sepharose Big Beads. The vitamin K-dependent coagulation factors co-eluted with FVIII from the anion exchange columns. In the second step of purification, when Sepharose 6FF was used, 70% of FVIII activity was recovered free from vitamin K-dependent factors.
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This paper examines the local power of the likelihood ratio, Wald, score and gradient tests under the presence of a scalar parameter, phi say, that is orthogonal to the remaining parameters. We show that some of the coefficients that define the local powers remain unchanged regardless of whether phi is known or needs to be estimated, where as the others can be written as the sum of two terms, the first of which being the corresponding term obtained as if phi were known, and the second, an additional term yielded by the fact that phi is unknown. The contribution of each set of parameters on the local powers of the tests can then be examined. Various implications of our main result are stated and discussed. Several examples are presented for illustrative purposes
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The starting point of this article is the question "How to retrieve fingerprints of rhythm in written texts?" We address this problem in the case of Brazilian and European Portuguese. These two dialects of Modern Portuguese share the same lexicon and most of the sentences they produce are superficially identical. Yet they are conjectured, on linguistic grounds, to implement different rhythms. We show that this linguistic question can be formulated as a problem of model selection in the class of variable length Markov chains. To carry on this approach, we compare texts from European and Brazilian Portuguese. These texts are previously encoded according to some basic rhythmic features of the sentences which can be automatically retrieved. This is an entirely new approach from the linguistic point of view. Our statistical contribution is the introduction of the smallest maximizer criterion which is a constant free procedure for model selection. As a by-product, this provides a solution for the problem of optimal choice of the penalty constant when using the BIC to select a variable length Markov chain. Besides proving the consistency of the smallest maximizer criterion when the sample size diverges, we also make a simulation study comparing our approach with both the standard BIC selection and the Peres-Shields order estimation. Applied to the linguistic sample constituted for our case study, the smallest maximizer criterion assigns different context-tree models to the two dialects of Portuguese. The features of the selected models are compatible with current conjectures discussed in the linguistic literature.