A comparative evaluation of the CF:CS and CRS models in Pb-210 chronological studies applied to hydrographic basins in Brazil

The Constant Flux: Constant Sedimentation (CF:CS) and Constant Rate of Supply (CRS) of unsupported/excess Pb-210 models have been applied to a Pb-210 data set providing of eighteen sediments profiles sampled at four riverine systems occurring in Brazil, South America: Corumbatai River basin (S1=Site 1, Sao Paulo State), Atibaia River basin (S2=Site 2, Sao Paulo State), Ribeirao dos Bagres basin (S3=Site 3, Sao Paulo State) and Amazon River mouth. (S4=Site 4, Amapa State). These sites were chosen for a comparative evaluation of the performance of the CF:CS and CRS models due to their pronounced differences on the geographical location, geological context, soil composition, biodiversity, climate, rainfall, and water flow regime, among other variable aspects. However, all sediments cores exhibited a common denominator consisting on a database built from the use of the same techniques for acquiring the sediments major chemical composition (SiO2, Al2O3, Na2O, K2O, CaO, MgO, Fe2O3, MnO, P2O5, TiO2 and LOI-Loss on Ignition) and unsupported/excess 210Pb activity data. In terms of sedimentation rates, the performance of the CRS model was better than that of the CF:CS model as it yielded values more compatible with those expected from field evidences. Under the chronological point of view, the CRS model always provided ages within the permitted range of the Pb-210-method in the studied sites, whereas the CF:CS model predicted some values above 150 years. The SiO2 content decreased in accordance with the LOI increase in all cores analyzed and such inverse relationship was also tracked in the SiO2-LOI curves of historical trends. The SiO2-LOI concentration fluctuations in sites S1 and S3 also coincided with some Cu and Cr inputs in the drainage systems. (C) 2014 Elsevier Ltd. All rights reserved.

O mercado editorial na forma����o dos professores da educa����o b��sica: levantamento e caracteriza����o de revistas pedag��gicas (1996-210)

A pesquisa tem por foco o mercado editorial voltado para a forma����o dos professores da educa����o b��sica, com ��nfase para as revistas pedag��gicas com periodicidade regular em circula����o na regi��o Sudeste do pa��s. Objetivou-se reconhecer e caracterizar manifesta����es desse mercado a partir da an��lise da materialidade das revistas, buscando encontrar tamb��m representa����es sobre os professores e sua profiss��o. O trabalho foi realizado sob uma abordagem qualitativa, nos moldes da pesquisa documental. Em um primeiro momento, realizou-se a identifica����o de quais s��o as revistas pedag��gicas dispon��veis no mercado e a que tipo de profissional elas se destinam, partindo de levantamento de materiais presentes em bancas de jornal, livrarias, bibliotecas e tamb��m em sites especializados. O segundo momento caracteriza-se pela an��lise e compara����o da materialidade das revistas. Trata-se de um Trabalho de Conclus��o de Curso que teve apoio financeiro pelo Programa Institucional de Bolsas de Inicia����o Cient��fica da Pr��-Reitoria (PROPE) de Pesquisa da UNESP (PIBIC/Reitoria). �� parte do projeto ���Mercado de forma����o docente: constitui����o, funcionamento, possibilidades e limites���, financiado pelo CNPq, que por sua vez integra o Projeto Tem��tico FAPESP ���Programas Especiais de Forma����o de Professores, educa����o a dist��ncia e escolariza����o: pesquisas sobre novos modelos de forma����o em servi��o

Pb-210 and compositional data of sediments from Rondonian lakes, Madeira River basin, Brazil

Conselho Nacional de Desenvolvimento Cient��fico e Tecnol��gico (CNPq)

Pedagogical practices carried out during an in-service teachers education project: approaching history and philosophy of science to physics teaching

We report here part of a research project developed by the Science Education Research Group, titled: "Teachers��� Pedagogical Practices and formative processes in Science and Mathematics Education" which main goal is the development of coordinated research that can generate a set of subsidies for a reflection on the processes of teacher training in Sciences and Mathematics Education. One of the objectives was to develop continuing education activities with Physics teachers, using the History and Philosophy of Science as conductors of the discussions and focus of teaching experiences carried out by them in the classroom. From data collected through a survey among local Science, Physics, Chemistry, Biology and Mathematics teachers in Bauru, a S��o Paulo State city, we developed a continuing education proposal titled ���The History and Philosophy of Science in the Physics teachers��� pedagogical practice���, lasting 40 hours of lessons. We followed the performance of five teachers who participated in activities during the 2008 first semester and were teaching Physics at High School level. They designed proposals for short courses, taking into consideration aspects of History and Philosophy of Science and students��� alternative conceptions. Short courses were applied in real classrooms situations and accompanied by reflection meetings. This is a qualitative research, and treatment of data collected was based on content analysis, according to Bardin [1].