Interfaces entre as políticas educacionais e os marcadores sociais : Quem sao os alunos que fracassam num contexto em todos têm direito a educaçao?

A implantaçao da obrigatoriedade do acesso à escola pública de Ensino Fundamental no Brasil, a partir do final dos aos 1980, produziu uma nova realidade no sistema de ensino. Por um lado, a taxa de frequência da escola básica passou de 75,03 (1990) para 92,14 (2010). Em contrapartida, a taxa de analfabetismo de pessoas com mais de 18 anos ainda é de 10,19 e somente 54,92 das pessoas com 18 anos ou mais tem Ensino Fundamental completo. Um conjunto de contradiçoes produzidas e reproduzidas sob o enfoque da justiça escolar a qual, norteia à universalizaçao do acesso a escola básica. Neste sentido, a ideia central desse trabalho foi reconhecer o perfil socioeducacional dos alunos em situaçao de fracasso escolar (repetência, distorçao idade-série e evasao escolar) no estado brasileiro que apresenta o melhor índice desenvolvimento da escola básica. Para tanto, foram analisadas as respostas de 87.607 questionários respondidos por alunos do 9o ano, participantes da Prova Brasil 2011. Com auxílio do software SPSS, foram produzidos procedimentos estatísticos para sistematizar e ampliar a análise que teve com suporte teórico as reflexoes preconizadas por distintos autores da Sociologia da Educaçao

Anisotropy and acoustic properties at DSDP Holes 62-463 and 62-465A

Variations of acoustic properties within the sediment column may significantly affect the propagation of acoustic energy in the upper portion of the oceanic crust. Moreover, the acoustic properties of sediments reflect their mineral compositions, fabrics, and degrees of compaction and cementation. Hence, the physical properties of indurated deep-sea sediments are of considerable geophysical and geological interest. Chalks and limestones are particularly important because substantial accumulations of biogenic carbonates are generally present at the base of the deep-sea sediment column, and high-standing features such as Hess Rise are capped by calcareous deposits. This paper constitutes a preliminary report of the compressional-wave velocities and densities of 31 indurated calcareous sediment samples recovered at DSDP Sites 463 and 465, in the Mid-Pacific Mountains and on Hess Rise, respectively. The sample set includes nine pairs of samples in which velocities were measured parallel and perpendicular to bedding to determine the velocity anisotropy of the sediment. This research is part of an ongoing study of the seismic properties of indurated deep-sea carbonates.

Mineralogy and pyrolysis at DSDP Hole 62-463

A 15-meter sequence of early Aptian organic-matter-rich sediments, cored at Deep Sea Drilling Project Site 463 (western Mid-Pacific Mountains) has been submitted for detailed mineralogical studies (XRD, SEM) and organiccarbon characterization. Although intense diagenesis has obscured the sedimentary record of depositional conditions, the history has been tentatively reconstructed. Through sustained volcanic activity and alteration processes on the archipelago, large amounts of silica were released into the sea water, resulting in a "bloom" of radiolarians. Hard parts settled in large amounts, yielding a hypersiliceous sediment; amorphous silica was diagenetically transformed into chalcedony, opal-CT and clinoptilolite through dissolution and recrystallization. Oxidization of part of the radiolarian soft parts (1) depleted the sea water in dissolved oxygen, allowing the burial of organic matter, and (2) generated carbon dioxide which led to dissolution of most of the calcareous tests. Moderate depositional depth and a high sedimentation rate are though to have prevailed during this episode. An immature stage of evolution is assigned to the studied organic matter, which is of two origins: autochthonous marine material, and allochthonous humic compounds and plant debris. Rhythmic sedimentation characterizes the distribution of the organic matter; each sequence shows (1) an upward progressive increase in organic-carbon content, and (2) an upward enrichment in marine organic matter.