907 resultados para Early childhood education. Early grades of elementary school


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Includes bibliography

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Includes bibliography

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There is species divergence in control of DNA methylation during preimplantation development. The exact pattern of methylation in the bovine embryo has not been established nor has its regulation by gender or maternal signals that regulate development such as colony stimulating factor 2 (CSF2). Using immunofluorescent labeling with anti-5-methylcytosine and embryos produced with X-chromosome sorted sperm, it was demonstrated that methylation decreased from the 2-cell stage to the 6-8 cell stage and then increased thereafter up to the blastocyst stage. In a second experiment, embryos of specific genders were produced by fertilization with X- or Y-sorted sperm. The developmental pattern was similar to the first experiment, but there was stage × gender interaction. Methylation was greater for females at the 8-cell stage but greater for males at the blastocyst stage. Treatment with CSF2 had no effect on labeling for DNA methylation in blastocysts. Methylation was lower for inner cell mass cells (i.e., cells that did not label with anti-CDX2) than for trophectoderm (CDX2-positive). The possible role for DNMT3B in developmental changes in methylation was evaluated by determining gene expression and degree of methylation. Steady-state mRNA for DNMT3B decreased from the 2-cell stage to a nadir for D 5 embryos >16 cells and then increased at the blastocyst stage. High resolution melting analysis was used to assess methylation of a CpG rich region in an intronic region of DNMT3B. Methylation percent decreased between the 6-8 cell and the blastocyst stage but there was no difference in methylation between ICM and TE. Results indicate that DNA methylation undergoes dynamic changes during the preimplantation period in a manner that is dependent upon gender and cell lineage. Developmental changes in expression of DNMT3B are indicative of a possible role in changes in methylation. Moreover, DNMT3B itself appears to be under epigenetic control by methylation. © 2013 Dobbs et al.

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Phylogeographic studies provide an important framework for investigating the mechanisms operating during the earliest stages of speciation, as reproductive barriers can be examined among divergent lineages in a geographic context. We investigated the evolution of early stages of intrinsic postmating isolation among different populations and lineages of Epidendrum denticulatum, a Neotropical orchid distributed across different biomes in South America. We estimated genetic diversity and structure for both nuclear and plastid markers, using a haplotype network, differentiation tests, Bayesian assignment analysis, and divergence time estimates of the main lineages. Reproductive barriers among divergent lineages were examined by analyzing seed viability following reciprocal crossing experiments. Strong plastid phylogeographic structure was found, indicating that E. denticulatum was restricted to multiple refuges during South American forest expansion events. In contrast, significant phylogeographic structure was not found for nuclear markers, suggesting higher gene flow by pollen than by seeds. Large asymmetries in seed set were observed among different plastid genetic groups, suggesting the presence of polymorphic genic incompatibilities associated with cytonuclear interactions. Our results confirm the importance of phylogeographic studies associated with reproductive isolation experiments and suggest an important role for outbreeding depression during the early stages of lineage diversification. © 2013 The Society for the Study of Evolution.

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Paracoccidioidomycosis is a human systemic mycosis caused by the fungus Paracoccidioides brasiliensis. The mechanisms involved in innate immune response to this fungus are not fully elucidated. Leukotrienes are known to be critical for the clearance of various microorganisms, mainly by mediating the microbicidal function of phagocytes. We investigated the involvement of leukotriene B4 in the early stages of experimental paracoccidioidomycosis, which was induced by intratracheal inoculation of the fungus in selected mouse lines. The mouse lines utilized were produced through bi-directional phenotypic selection, endowed with maximal or minimal acute inflammatory reactivity, and designated AIRmax and AIRmin, respectively. AIRmax mice were more resistant to the infection, which was demonstrated by reduced lung fungal loads. However, the two lines produced similar amounts of leukotriene B4, and pharmacological inhibition of this mediator provoked similar fungal load increases in the two lines. The lower fungal load in the AIRmax mice was associated with a more effective inflammatory response, which was characterized by enhanced recruitment and activation of phagocytic cells and an increased production of activator cytokines. This process resulted in an increased release of fungicidal molecules and a diminution of fungal load. In both lines, leukotriene production was associated with a protective response in the lung that was consequent to the effect of this eicosanoid on the influx and activation of phagocytes. © 2013 ISHAM.

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Pós-graduação em Educação - IBRC

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Pós-graduação em Serviço Social - FCHS

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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O presente estudo objetiva desvelar, a memória de escola de adolescentes em conflito com a Lei e que cumprem medidas na Fundação da Criança e do Adolescente do Pará, na Unidade Socioeducativa de Internação de Val-de-Cães. A intenção é traçar por meio dos enunciados discursivos destes sujeitos, suas incursões no ambiente educacional e assim identificar o que os fizeram abandonar a escola de forma precoce e/ou apresentarem em seus currículos escolares um alto índice de repetência. As questões que norteiam este estudo são: Que fatores contribuíram para que estes adolescentes abandonassem o ambiente educacional de forma precoce? Até que ponto a escola e a exclusão social foram fatores relevantes para o envolvimento destes adolescentes com a violência e criminalidade? Qual o comprometimento da escola na formação dos adolescentes em conflito com a Lei, levando em consideração o papel da escola na formação do sujeito? Partindo das questões norteadoras o estudo objetiva identificar que Rede de Significados estão envolvidas nestes questionamentos. A amostra contou com a participação de 18 adolescentes na faixa etária de 12 a 17 anos de idade, com escolaridade de 13 série do ensino básico até a 83 série do ensino fundamental, nascidos no Estado do Pará, cumprindo medidas socioeducativas pelo ato infracional que vai do dano ao patrimônio público (Art. 163) a assalto seguido de morte (Art.12l c/c Art. 14). Foi utilizado como instrumentos de coleta de dados a entrevista semi-estruturada e documentos cedidos pela Fundação, como os prontuários, com os dados pessoais e acompanhamento de cada adolescente. O corpus da pesquisa foi analisado por meio dos seguintes eixos-temáticos: Escola; Família; Violência e Criminalidade; Relações Interpessoais e Perspectivas Futuras. O referencial teórico utilizado para análise dos dados segue a concepção de Bakhtin sobre a rede de significados e de autores que discutem aspectos relacionados aos eixos temáticos. Para tal utilizei autores como ROSSETTI e FERRElRA (2004); ARROYO (1997); BOSSA (2002); CORDIÉ (1996); VYGOTSKY (2000); PINTO (2002), entre outros. Nesta perspectiva, o objetivo foi o de encontrar correspondência com os princípios e critérios que pudessem contribuir para a fundamentação desta análise, favorecendo a interação entre as diferentes formas de produção de conhecimento, sobretudo, pelos dados apresentados ao processo de escolarização destes sujeitos, uma vez que contribuiu para reprovações, repetências, defasagens, e não raro, para a evasão escolar.