Geometria: um estudo sobre ângulos e polígonos, no 9º ano de escolaridade, com recurso ao GeoGebra

Dissertação para obtenção do Grau de Mestre em Ensino de Matemática no 3º ciclo do Ensino Básico e no SecundárioO presente estudo pretende analisar qual o contributo do ambiente de geometria dinâmica – GeoGebra - na aprendizagem da geometria, nomeadamente, no estudo de ângulos e polígonos, com alunos do 9º ano de escolaridade. Através do uso deste software em sala de aula, procurou-se ter uma melhor compreensão do interesse e motivação dos discentes, e de que modo o seu uso contribui para a aprendizagem de novos conceitos. A revisão de literatura baseou-se essencialmente na utilização das tecnologias na escola, nomeadamente, no ensino da matemática e particularizou-se para a aprendizagem em ambientes de geometria dinâmica. A metodologia utilizada foi de natureza qualitativa e recorreu a estudo de caso. A investigadora assumiu o papel de observadora participante e assistiu a todas as aulas que fazem parte deste trabalho. Na recolha de dados foram utilizados os seguintes instrumentos: notas de campo, registo de vídeo, inquéritos, entrevistas semiestruturada e documentos produzidos pelos alunos. Na análise de dados são descritas e analisadas as tarefas e exercícios realizados pelos quatro alunos em estudo. Estes apresentaram, de início, algumas dificuldades no manuseamento da ferramenta, no entanto, com o decorrer das aulas notou-se um melhor desempenho, o que os levou a ter mais confiança na resolução das tarefas e, consequentemente, menos tempo de execução. Nas últimas aulas apresentaram fluidez de raciocínio e confiança no trabalho realizado, mostrando que tinham aprendido os conceitos de ângulo, ângulo ao centro e ângulos inscrito numa circunferência, as propriedades que relacionam os ângulos ao centro, ângulos inscritos e arcos de uma mesma circunferência e as propriedades relativas à soma dos ângulos internos de polígonos convexos

Núcleos de Ensino da Unesp: artigos 2008

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Characterisation of microbial attack on archaeological bone

As part of an EU funded project to investigate the factors influencing bone preservation in the archaeological record, more than 250 bones from 41 archaeological sites in five countries spanning four climatic regions were studied for diagenetic alteration. Sites were selected to cover a range of environmental conditions and archaeological contexts. Microscopic and physical (mercury intrusion porosimetry) analyses of these bones revealed that the majority (68%) had suffered microbial attack. Furthermore, significant differences were found between animal and human bone in both the state of preservation and the type of microbial attack present. These differences in preservation might result from differences in early taphonomy of the bones. © 2003 Elsevier Science Ltd. All rights reserved

Brazilian Flora 2020: Leveraging the power of a collaborative scientific network

International audienceThe shortage of reliable primary taxonomic data limits the description of biological taxa and the understanding of biodiversity patterns and processes, complicating biogeographical, ecological, and evolutionary studies. This deficit creates a significant taxonomic impediment to biodiversity research and conservation planning. The taxonomic impediment and the biodiversity crisis are widely recognized, highlighting the urgent need for reliable taxonomic data. Over the past decade, numerous countries worldwide have devoted considerable effort to Target 1 of the Global Strategy for Plant Conservation (GSPC), which called for the preparation of a working list of all known plant species by 2010 and an online world Flora by 2020. Brazil is a megadiverse country, home to more of the world's known plant species than any other country. Despite that, Flora Brasiliensis, concluded in 1906, was the last comprehensive treatment of the Brazilian flora. The lack of accurate estimates of the number of species of algae, fungi, and plants occurring in Brazil contributes to the prevailing taxonomic impediment and delays progress towards the GSPC targets. Over the past 12 years, a legion of taxonomists motivated to meet Target 1 of the GSPC, worked together to gather and integrate knowledge on the algal, plant, and fungal diversity of Brazil. Overall, a team of about 980 taxonomists joined efforts in a highly collaborative project that used cybertaxonomy to prepare an updated Flora of Brazil, showing the power of scientific collaboration to reach ambitious goals. This paper presents an overview of the Brazilian Flora 2020 and provides taxonomic and spatial updates on the algae, fungi, and plants found in one of the world's most biodiverse countries. We further identify collection gaps and summarize future goals that extend beyond 2020. Our results show that Brazil is home to 46,975 native species of algae, fungi, and plants, of which 19,669 are endemic to the country. The data compiled to date suggests that the Atlantic Rainforest might be the most diverse Brazilian domain for all plant groups except gymnosperms, which are most diverse in the Amazon. However, scientific knowledge of Brazilian diversity is still unequally distributed, with the Atlantic Rainforest and the Cerrado being the most intensively sampled and studied biomes in the country. In times of “scientific reductionism”, with botanical and mycological sciences suffering pervasive depreciation in recent decades, the first online Flora of Brazil 2020 significantly enhanced the quality and quantity of taxonomic data available for algae, fungi, and plants from Brazil. This project also made all the information freely available online, providing a firm foundation for future research and for the management, conservation, and sustainable use of the Brazilian funga and flora