Fragmentos do pensamento dialético na história da construção das ciências da natureza

Este trabalho tem por objetivo identificar uma possível inclinação das ciências naturais em direção ao materialismo dialético. Para tanto, procura-se apresentar a história da dialética a partir da discussão racionalismo/empirismo moderno e seus desdobramentos até as tendências dialéticos contemporâneas. Os autores discutidos são Kant, Hegel, Marx, Engels, Lenin, Horkheimer, Marcuse, Habermas, Bachelard e suas escolas epistemológicas, completadas por Althusser, Lefebvre e Kedrov. Ao lado desses autores discutem-se outros, das duas últimas décadas, procurando extrair-lhes o olhar dialético, oculto em seus discursos acerca da ciência do fim do século. Também se procura encontrar na mecânica quântica, nos fractais, na lógica para-consistente, nos modelos matemáticos e na biologia antideterminista, argumentos para existência de uma forma de abordagem dialética da natureza. Por último, procura-se refletir acerca dos motivos da resistência ao método dialético apresentado pela maioria dos cientistas ocidentais e, sua possível superação.

Hematological changes in sheep inoculated with natural and Cobalt60-irradiated Crotalus durissus terrificus venom (Laurenti, 1768)

Natural (NV) and Cobalto60-irradiated (IrV) Crotalus durissus terrificus venom were used to evaluate serum production capacity of sheep and possible hematological and biochemical effects. Freeze-dried venom aliquots were diluted in acidified saline solution (NaCl 150 mM, pH 3.0) and irradiated by a Cobalt 60 source at a dose of 5.54 x 102 Gy/h and a concentration of 2.000 Gy. Twelve sheep were divided into two groups of six animals. One group received irradiated venom (IrV) and the other natural venom (NV). Three antigen doses (venom) were administered at monthly intervals. Blood samples were collected weekly for analysis of serum neutralization potency and capacity, complete blood count (CBC), total plasma protein, fibrinogen, albumin, and globulin. At the end of the experiment, the animals were challenged with a LD50 for sheep and showed no signs of envenoming. The two groups did not present clinical alterations. Results of the total leukocyte count did not present interaction or time factor effect for both groups, but there was a different action between them, with the NV group presenting more cells than the IrV group. The leukocyte increase to 13,000/ml indicates that slight leukocytosis occurred in the week after the first inoculation in the NV group. There was no statistically significant difference between groups in the absolute count of segmented neutrophils, eosinophils, and lymphocytes but there were statistically significant oscillations in values at the different collecting times. The NV group presented an increase in the absolute neutrophil count after the first inoculation that persisted for 5 weeks. In the IrV group, the increase in neutrophils occurred only in the first week returning to normal in the following weeks. The alterations in the neutrophil count are indicative of systemic inflammatory response related to cytokine release; response was more marked in the NV group, showing its greater toxicity.

Educação ambiental e educação em valores em livros didáticos de ciências naturais

Os valores têm sido considerados importante conteúdo de ensino, sobretudo ao tratarmos de certas temáticas, como a ambiental. Procurando analisar o tratamento dado à dimensão valorativa da temática ambiental em três coleções de Ciências Naturais voltadas às séries finais do Ensino Fundamental verificamos a predominância da visão antropocêntrica, sendo a natureza valorizada em função de sua utilidade para o ser humano. O predomínio da valorização do conhecimento científico em detrimento de outras formas de conhecimento, da ação humana individual em detrimento da coletiva e a simples apresentação de leis ambientais foram outros aspectos problemáticos encontrados. Uma das coleções, entretanto, além de valorizar o trabalho coletivo dos alunos, também se destacou pela maior ênfase dada à dimensão estética, implicando uma visão de mundo menos utilitarista e um tratamento mais adequado do conteúdo valorativo da temática ambiental.

In vitro cytotoxicity of some natural and semi-synthetic isocoumarins from Paepalanthus bromelioides

Numerous natural compounds have a potential for therapeutic applications, but may have to be chemically modified to alter toxic side effects. We investigated structural parameters that could affect the cytotoxicity of isocoumarins similar to 9,10-dihydroxy-5,7-dimethoxy-1H-naphtho(2,3c)pyran-1-one (paepalantine 1). Paepalantine 1 has antimicrobial activity, as well as significant in vitro cytotoxic effects in the McCoy cell line. Two other natural and two semi-synthetic isocoumarins with similar structures obtained from the capitula of Paepalanthus bromelioides were tested on the same cell line by the neutral red assay. Substitution of the 9 and/or 10-OH group made these compounds less cytotoxic.

Um estudo dos significados do conceito de tecnologia nos Parâmetros Curriculares Nacionais do Ensino Médio - PCNEM

Pós-graduação em Educação - IBRC

Sobre a filosofia da mente de John Searle

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Didática de ciências e de biologia na perspectiva da pedagogia histórico-crítica

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Sólitons e gravitação

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

O processo de ensino - aprendizado - avaliação de matemática através da resolução de problemas no contexto da formação inicial do professor de matemática

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Atividades práticas no ensino de ciências: saberes docentes e formação do professor

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Injustiça e poder segundo Noam Chomsky

Injustice and power according to Noam Chomsky. In the beginning of the Politics, Aristotle establishes the two lesser forms of sociability: the relationships between man and woman and between master and the slave. In this context, he observes that “Hellenes are natural masters of barbarians” and the reason is that Greeks know philosophy and barbarians still resort to violence (ARISTOTLE, Politics, 1252a.). Shortly after defines “just war” as a war that has a fair cause, that is, which is well justified by philosophy or a fair speech (ARISTOTLE, Politics, 1255a.). This scene briefly expresses the manner in which the USA understands their role in the contemporary world. Chomsky points out the political use of massive military force of his country and denounces how it articulates internally and externally. He affirms that politics is excessively submitted to “ideology”, to doxa, as opposed to natural sciences. His militancy, thus, only advocates freedom and unrestricted right to information. In Camelot, the Kennedy years (1993), for example, the MIT’s professor collects information from congressmen’s speeches and government officials and from secret documents made public and he explicits the methods and actions of the US government. Thereby he can conclude that the US has, for historical reasons, an internal posture that is advocate or contrary to what they imposes to other countries. Power and justice on the one hand, force and injustice on the other –according to their own political discourse.

Caracterização do compósito obtido a partir de borracha natural com negro e resíduos de couro aplicado como pisos e revestimentos

Pós-graduação em Ciência e Tecnologia de Materiais - FC

Thoron and radon activity concentration in mineral waters of spas from southeastern Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Interfaces da construção da prática docente no ensino de ciências naturais nos anos iniciais da escola pública municipal de Manaus - AM

Pós-graduação em Educação - FCT

Diferentes percepciones de un mismo ambiente: la cuestión del género en la enseñanza de la ciência

This paper relates some considerations resulting from a thesis study in Biological Sciences held at Universidade Estadual Paulista - Unesp, Bauru Campus. Considering the perceptual act endowed with simultaneous actions of the cognitive apparatus and the individual's life history as the merleau-pontyana phenmomenon tells us, the work aimed to identify how boys and girls in elementary school realize a natural savanna. The study was realized with the extension project "Walking and learning at the cerrado” in the Center for Memory and Dissemination of Science and Technology (CDMCT) of Postgraduate Education for Science in the same institution. Classes were held in these practical activities, monitored by undergraduate and graduate students, and, the project focuses on students from public and private schools in Bauru and region, and other visiting groups. Data collection was performed using the representations in the form of free drawings of students of their environment after the activity. Through qualitative and quantitative analysis, the results allowed us to highlight differences in the way in which genders perceived and thus represented the fragment of cerrado vegetation. The male drawings contained a larger amount of non-living elements, whereas the representations by women, besides their botanical details, often drew on animals and people. The framework of the drawings by the boys took the nearest way, whereas by the girls more often considered the representations and the entire context of the site visited. So, we emphasize the need for further discussions within the perception of the environment to consider differences in the representations of boys and girls within the context of the teaching of natural sciences, seeking, however, to avoid unsubstantiated preconceptions that may cause any degree of discrimination.