Análise de episódios de ensino : articulando os discursos teórico e prático na formação de professores

O presente trabalho apresenta a estrutura de uma disciplina de prática de ensino que está fundamentada na matriz sociocultural. A ação mediada é sugerida na disciplina como uma construção teórica que permite desenvolver um modelo de organização do ensino, no qual o professor se oriente para planejar suas aulas. O modelo topológico de ensino é uma ferramenta metodológica derivada da teoria da ação mediada que julgamos capaz de subsidiar a organização do ensino no cotidiano da sala de aula e em diferentes estágios da vida escolar. Para caracterizar o domínio e apropriação das diferentes ferramentas culturais utilizadas pelos professores, quando esses planejam e analisam as sequências de ensino, coletamos dados em questionários, registro audiovisual das aulas e relatórios individuais. Dados de resposta a um questionário são apresentados e analisados neste trabalho

G.I.S. technologies for data collection, management and visualization of large slope instabilities: two applications in the Western Italian Alps

International audienceLarge slope instabilities are gravitational phenomena whose main characteristics are the multi-km2 area extension and the complex geometrical, geomorphological and geomechanical settings. Several studies outlined their importance in spatial and temporal occurrence of natural hazards on wide mountain areas and their possible interaction in human activities. For the study of large slope instability and deep seated slope gravitational deformations in the Susa and Aosta Valleys (Western Italian Alps) a complete multiscale program (spatial and temporal) analysis has been performed, giving contributions to the reconstruction and settings of their possible evolution. A complex geodatabase has been created, including thematic elements from field-data collection (geomorphology, hydrology, lithology, structural geology) and instability events analysis from data archives and remote sensing images. To facilitate the management of a large amount of collected data a G.I.S. (Geographical Information System) has been developed, including two main levels of information: local and regional. Local information is mainly devoted to detailed geothematic mapping of single instability phenomena. Clot Brun case study is presented, where original and derived landslide features have been elaborated through arithmetical and statistical operations, in order to identify different instability zones and to assess displacements and state of activity through-time. Regional information collected for a landslide inventory of Aosta Valley (IFFI project) summarizes historical and remote sensing data, combined with metadata from local analysis, in order to assess spatial and temporal hazards. To avoid problems of data accuracy (quality and positioning) due to different source archives, a semi-automatic system for selection and validation of data has been created, based on their spatial characteristics (buffer analysis and control). G.I.S. technologies have been used to archive, manage and visualize collected data through 2-D and 3-D models of single case studies and regional distribution of large slope instabilities

Time response of a landslide to meteorological events

International audienceA landslide affecting two small villages located on the Northwestern Italian Apennines has been investigated since the year 2000 through the use of different equipment. A complex monitoring system has been installed in the area. The system includes several inclinometers, piezometers and a raingauge. An Automatic Inclinometric System (AIS) has been also installed that automatically performs measurements, twice a day, along the entire length of a pipe that is 45 m deep. This monitoring system has been set up to identify a methodology that allowed to deal with landslides, trying to predict their behaviour beforehand for warning purposes. Previous researches carried out in the same area for a period of about 7 months, in the year 2000, have allowed to identify a correlation between deep slope movements and rainfalls. In particular, it has been possible to determine the time lag needed for a rainfall peak to produce a corresponding peak of the landslide movements; this time lag was of 9 days. This result was possible because the AIS allows to obtain, as mentioned, daily inclinometric measurements that can be correlated with the recorded rainfalls. In the present report we have extended the analysis of the correlation between deep slope movements and rainfalls to a greater period of observation (2 years) to verify over this period the consistency of the time lag mentioned above. The time lag previously found has been confirmed. We have also examined the possibility to extend to the entire landslide body the correlation that has been found locally, analyzing the results of the remaining inclinometric tubes with traditional reading installed on the landslide and comparing them with the results of the AIS. The output of the tubes equipped with piezometric cells has also been analyzed. The relations existing among rainfalls, ground water level oscillations and the related slope movements have been explore

A formação do conceito científico mediado pela produção escrita de gênero escolar-científico no currículo de química

Este artigo propõe uma discussão sobre fundamentos da teoria da cognição na formação do conceito científico proposta por Vigotski e sua relação com aspectos da metalingüística proposta por Bakhtin, quando discute as esferas da atividade humana,as noções de enunciado e seus aspectos intimamente ligados, o conteúdo temático, o estilo e a construção composicional, conformando os gêneros do discurso. As tipologias propostas por Schneuwly & Dolz adquirem importância relevante na construção dialógica dos gêneros do discurso escrita por estudantes e mediada por modelos padrão para introdução e aplicação no currículo formal de química no ensino médio

Preface Results of the open session on "Documentation and monitoring of landslides and debris flows" for mathematical modelling and design of mitigation measures, held at the EGU General Assembly 2009

The papers that are here presented and summarised represent the recent scientific contributions of some authors coming from different countries and working in the fields of monitoring, modelling, mapping and design of mitigation measures against mass movements. The authors had the opportunity to present their recent advancements, discuss each other needs and set forth future research requirements during the 2009 EGU General Assembly, so that their scientific contributions can be considered the result of the debates and exchanges that were set among scientists and researchers, either personally or during the review phase since that date. In this resume, the scientific papers of the special issue are divided according to different thematic areas and summarised. The most innovative scientific approaches proposed in the special issue, regarding the monitoring methodologies, simulation techniques and laboratory equipment are described and summarised. The obtained results are very promising to keep on future research at a very satisfactory level

Survey solutions for 3D acquisition and representation of artificial and natural caves

A three-dimensional survey of natural caves is often a difficult task due to the roughness of the investigated area and the problems of accessibility. Traditional adopted techniques allow a simplified acquisition of the topography of caves characterized by an oversimplification of the geometry. Nowadays, the advent of LiDAR and Structure from Motion applications eased three-dimensional surveys in different environments. In this paper, we present a comparison between other three-dimensional survey systems, namely a Terrestrial Laser Scanner, a SLAM-based portable instrument, and a commercial photo camera, to test their possible deployment in natural caves survey. We presented a comparative test carried out in a tunnel stretch to calibrate the instrumentation on a benchmark site. The choice of the site is motivated by its regular geometry and easy accessibility. According to the result obtained in the calibration site, we presented a methodology, based on the Structure from Motion approach that resulted in the best compromise among accuracy, feasibility, and cost-effectiveness, that could be adopted for the three-dimensional survey of complex natural caves using a sequence of images and the structure from motion algorithm. The methods consider two different approaches to obtain a low resolution complete three-dimensional model of the cave and ultra-detailed models of most peculiar cave morphological elements. The proposed system was tested in the Gazzano Cave (Piemonte region, Northwestern Italy). The obtained result is a three-dimensional model of the cave at low resolution due to the site’s extension and the remarkable amount of data. Additionally, a peculiar speleothem, i.e., a stalagmite, in the cave was surveyed at high resolution to test the proposed high-resolution approach on a single object. The benchmark and the cave trials allowed a better definition of the instrumentation choice for underground surveys regarding accuracy and feasibility

A percepção dos estudantes sobre ciência e tecnologia : uma análise em Vigotski

Ao percebermos elementos da realidade o fazemos baseados em conhecimentos adquiridos anteriormente e analisados em torno da situação presente, interpretando os dados percebidos em função dos conteúdos psicológicos disponíveis no momento. O objeto é percebido como uma realidade completa e articulada e não como um conjunto de informações sensoriais (Vigotski). Assim o desenvolvimento do indivíduo, sua caminhada, suas experiências, o seu conhecimento de mundo têm implicações diretas no modo como a percepção se dá. Neste trabalho apresentaremos alguns resultados obtidos durante uma investigação realizada em uma escola pública na cidade de São Paulo/Brasil, com estudantes a respeito de percepções de Ciência e Tecnologia (CT) apresentadas por esses estudantes

APPLICATION OF ORGANIC ACIDS AND SALT IN REPLACEMENT OF SODIUM METABISULFITE IN DEHYDRATED CUBE APPLES

Increasingly the population adopts a healthy diet and becomes demanding about the nutritional value of food, which has increased the demand for dehydrated foods as a healthy and practical option for intermediate meals. Enzymatic browning is a phenomenon that induces changes in color, taste and nutritional losses and is related to the enzyme polyphenoloxidase, which uses phenolic compounds as substrates. The objective of this work was to evaluate the application of conservative solutions containing citric acid (AC), ascorbic acid (AA) and sodium chloride (NaCl), replacing sodium metabisulfite in preserving the color of dehydrated apples. Analyzes were performed to evaluate the stability of the apples, through the pH content, soluble solids and sensorial analysis. At the end of the 10 hrs drying process, the final humidity of the apples was 3.58%. The pH levels in all solutions remained similar, decreasing as the acid concentration increased. Soluble solids contents also presented few variations, explained due to the content of soluble solids present naturally in the fruits in natura. According to the analyzes performed, it can be seen that the conservative solution containing ascorbic acid, citric acid and NaCl was effective to control enzymatic browning, serving as a potential substitute for Sodium Metabisulfite

Determinação do grau de dialogia de interações virtuais assíncronas

Neste trabalho fazemos uma discussão sobre as interações discursivas em atividades educacionais não presenciais mediadas pela internet apontando algumas novas formas de linguagens que estão surgindo e discutindo formas de envolver o aluno na aprendizagem utilizando-se um estilo enunciativo que favorece os vínculos interpessoais. Aliado a isto, realizamos um estudo sobre as propriedades dualísticas do enunciado – as funções unívoca e dialógica – e elaboramos quatro categorias de análises – engajamento, problematização, retomada da fala do outro e referência a outros interlocutores – para subsidiar processos de tutoria pela internet, de forma que possamos, por meio delas, determinar o grau de dialogia de interações virtuais assíncronas