3,498 research outputs found

    A formação de professores de química e o conhecimento poderoso

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    O trabalho discute a concepção de Conhecimento Poderoso proposta por Young, que estabelece o denominado conhecimento especializado como condição da aquisição de um conhecimento emancipatório. Entendemos, porém que nas «ciências duras» tal é condição necessária, mas não suficiente, para consecução de tal empoderamento (empowerment). Defende-se que, além dele, serem os processos de uma ação pedagógica que «fale do mundo» um requisito essencial a ser valorizado na perspectiva de finalidades emancipatórias construídas no sentido de deslocar os futuros alunos de entornos intelectuais, sociais e culturais limitados. Também é apresentado resultado de pesquisa exploratória inicial, em uma universidade pública brasileira, evisando a detectar, se, na formação de professores, são incorporados elementos que lhes permitam «falar do mundo» em aulas de Química

    Efectos de la conectividad sobre comunidades de aves forestales de paisajes fragmentados adyacentes

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    We assessed bird sensitivity to forest fragmentation in two adjacent landscapes in the Atlantic Forest of southern Brazil. One landscape is naturally fragmented and has high connectivity, whereas the other is human-fragmented and has low connectivity. We tested whether the sensitivity of bird species to fragmentation depends more on the intrinsic characteristics of the birds than on landscape connectivity. Point counts were used to sample small and large forest remnants in each landscape. The abundance of each species in these remnants was used as a proxy for sensitivity. To test whether the two landscapes differ in connectivity, we compared the following landscape metrics: landscape shape index (LSI), proximity index (PROX) and connectance index (CONNECT). We analysed the sensitivity of 85 species, 51 of which occurred exclusively in one of the two landscapes. In the landscape with low connectivity we recorded a large number of sensitive species. Among the 34 species that occurred in both landscapes, 24 species (18 non-sensitive and six sensitive) had the same sensitivity. Landscape connectivity seems to be more significant when we focus on the bird communities as a whole. However, when we focus on the same bird species in different landscapes, intrinsic characteristics of species seem to affect their sensitivity to fragmentation more than does landscape connectivity, especially for bird species with lower sensitivity. Therefore, our results show that increasing landscape connectivity may not be the best tool for bird conservation in naturally fragmented landscapes. Nevertheless, it will be important to test further whether forest bird species are more sensitive to environmental degradation in naturally fragmented landscapes than in human-fragmented landscapes.En el presente estudio analizamos la sensibilidad de las aves a la fragmentación del bosque en dos paisajes contiguos de la Mata Atlántica del sur de Brasil. Uno de los paisajes está fragmentado de manera natural y presenta alta conectividad, mientras que en el otro la fragmentación es de origen antrópico y tiene baja conectividad. Evaluamos si la sensibilidad de las especies a la fragmentación depende más de sus características intrínsecas que de la conectividad del paisaje. Usamos puntos de conteo para estimar la abundancia de aves en fragmentos grandes y pequeños en cada paisaje, como un indicador de su sensibilidad a la fragmentación. Para testar si los dos paisajes difieren en conectividad calculamos las siguientes métricas del paisaje: índice de forma del paisaje (LSE), índice de proximidad (PROX) e índice de conectividad (CONNECT). Evaluamos la sensibilidad de 85 especies, de las cuales 51 ocurrieron solamente en uno de los dos paisajes. En el paisaje con baja conectividad registramos un mayor número de especies sensibles. Entre las 34 especies detectadas en los dos paisajes, 24 (18 no sensibles y 6 sensibles) mostraron la misma sensibilidad. Cuando consideramos la comunidad de aves en su conjunto la conectividad del paisaje resulta más relevante, sin embargo, al analizar la misma especie en diferentes paisajes, las características intrínsecas de la especie parecen afectar más su sensibilidad a la fragmentación que la conectividad del paisaje, especialmente en el caso de aves con baja sensibilidad. Nuestros resultados muestran que aumentar la conectividad del paisaje puede no ser la mejor herramienta para la conservación de las aves en paisajes fragmentados de manera natural. No obstante, sería importante estudiar si las aves forestales son más sensibles a la degradación ambiental en paisajes fragmentados naturalmente que en los fragmentados por la actividad humana.The CNPq (Brazilian Research Council) gave us financial support through the Mata Atlântica Program. E. V. Lopes received a PhD scholarship from CNPq during the present study and a sandwich scholarship for a four-month research stay at the Universidad de Alicante in Spain (processes 140353/2006-2 and 202232/2007-7, respectively). L. B. Mendonça received a PhD scholarship from CNPq (process 140317/2006-6). L. dos Anjos received a CNPq research productivity fellowship level 1D (process 305593-2007-2)

    Exercise Attenuates Renal Dysfunction with Preservation of Myocardial Function in Chronic Kidney Disease

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    Previous studies have suggested that exercise improves renal and cardiac functions in patients with chronic kidney disease. the aim of this study was to evaluate the effects of long-term aerobic swimming exercise with overload on renal and cardiac function in rats with 5/6 nefrectomy (5/6Nx). Eight Wistar rats were placed into 4 groups: Control (C), Control+Exercise (E), Sedentary 5/6Nx (NxS) and 5/6Nx+Exercise (NxE). the rats were subjected to swimming exercise sessions with overload for 30 min five days per week for five weeks. Exercise reduced the effect of 5/6Nx on creatinine clearance compared to the NxS group. in addition, exercise minimized the increase in mean proteinuria compared to the NxS group (96.9 +/- 10.0 vs. 51.4 +/- 9.9 mg/24 h; p<0.05). Blood pressure was higher in the NxS and NxE groups compared to the C and E groups (216 +/- 4 and 178 +/- 3 vs. 123 +/- 2 and 124 +/- 2 mm Hg, p<0.05). in the 200 glomeruli that were evaluated, the NxS group had a higher sclerosis index than did the NxE group (16% vs. 2%, p<0.05). Echocardiography demonstrated a higher anterior wall of the left ventricle (LV) in diastole in the NxS group compared with the C, E and NxE groups. the NxS group also had a higher LV posterior wall in diastole and systole compared with the E group. the developed isometric tension in Lmax of the heart papillary muscle was lower in the NxS group compared with the C, E and NxE groups. These results suggested that exercise in 5/6Nx animals might reduce the progression of renal disease and lessen the cardiovascular impact of a reduction in renal mass.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundacao Oswaldo Ramos (FOR)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Universidade Federal de São Paulo, UNIFESP EPM, Dept Med, Div Nephrol, São Paulo, BrazilUniversidade Federal de São Paulo, Cardiophysiol & Pathophysiol Lab, São Paulo, BrazilUniv São Paulo, Sch Med, Heart Inst InCor, Lab Genet & Mol Cardiol, São Paulo, BrazilUniversidade Federal de São Paulo, UNIFESP EPM, Dept Med, Div Nephrol, São Paulo, BrazilUniversidade Federal de São Paulo, Cardiophysiol & Pathophysiol Lab, São Paulo, BrazilWeb of Scienc

    Diacutaneous fibrolysis versus passive stretching after articular immobilisation : muscle recovery and extracellular matrix remodelling

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    Introduction Atrophy and muscle shortening due to articular immobilisation are common problems in musculoskeletal rehabilitation. Muscle stretching mechanical stimuli might be considered as the golden standard procedure to improve muscle flexibility in rehabilitation. Muscle stretching generates mechanotransduction, potentiating specific gene expression and promotes sarcomerogenesis and extracellular matrix remodelling on shortened and atrophied muscles. Hypothesis Diacutaneous fibrolysis, like stretching, uses an external force to stress connective and muscle tissues mechanically to treat muscle shortening; thus, it is widely used in clinical practice even if there is no evidence to support it. Considering this subject, we have hypothesised that diacutaneous fibrolysis can generate mechanotransduction, affecting muscle hypertrophy and extracellular matrix remodelling after immobilisation. Evaluation of hypothesis We have designed a laboratory experimental study with a sample of 50 rats. The sample was randomly divided into five groups: Control group (n = 10) with non–immobilised rats; 3–week immobilisation group (n = 10); 3–week immobilisation/3–week non–immobilisation group (n = 10);3–week immobilisation/3–week stretching group (n = 10); and 3–week immobilisation/3–week diacutaneous fibrolysis group (n = 10). All rats had their left tibiotarsal joint immobilised in maximum plantar flexion with the orthotics for 3 consecutive weeks. After the immobilisation period, the intervention groups received their respective intervention on their left triceps suralis for 3 weeks. Dependent variables of the study were sarcomere analysis, polymerase chain reaction, connective tissue density, collagen birefringence and matrix metalloproteinases. Statistical analysis was performed using analysis of variance and Duncan post hoc test was applied for differences between groups. For all calculations, a 5% (p < 0.05) significance level was established. Conclusion If the hypothesis is confirmed, the present study might provide evidence to support the use of this physical therapy resource widely used to treat muscle dysfunctions

    Parameters for three growth curves and factors that influence them for Bergamasca sheep in the Brasilia Region

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    A análise de um banco de dados de crescimento em ovinos Bergamácia (pesos até dois anos de idade de 1982 a 1996) foi feita usando-se métodos não-lineares para determinar parâmetros de três curvas (Brody, Richards e Logística) de crescimento. Os parâmetros das curvas foram analisados pelo Statistical Analysis System (SAS) usando o procedimento GLM e CORR para determinar fatores que influenciaram os parâmetros e as correlações entre os parâmetros e pesos dos animais. O sistema de manejo foi semi-extensivo com os ovinos ao pasto durante o dia e presos à noite para proteger dos predadores. Os fatores fixos incluídos foram ordem do parto, sexo do cordeiro, tipo de nascimento, mês e ano. As médias dos parâmetros das curvas foram: Richards - A = 50,024, B = 0,647, k = 0,003, M = 17,771 e R2 = 0,838; Brody - A= 52,763, B=0,885, k =0,003, R2= 0,842; Logístico - A=47,894, B=-3,895, k=0,007 e R²= 0,840. O meio ambiente influenciou o crescimento e a reprodução de ovinos na região de Brasília. A correlação negativa entre k e A indica que animais que amadurecem mais cedo têm menos probabilidade de atingir pesos adultos mais altos que animais que amadurecem tardiamente. A curva Logística estimou o peso adulto dos animais com média inferior às das outras curvas. Os pesos atuais estão, contudo, mais bem correlacionados com os estimados pela Logística. Não houve diferença entre os três tipos de curvas em termos de R2. O quadrado médio do resíduo foi maior para a curva de Richards. A curva recomendada para ajustar dados de crescimento de ovinos da raça Bergamácia é Logística. _________________________________________________________________________________ ABSTRACTFifteen years of data from a flock of Bergamasca sheep weighed every two weeks was analyzed using non-linear methods to determine parameters of three growth curves (Brody , Richards and Logistic). The curve parameters were analyzed using Statistical Analysis System (SAS) procedures GLM and CORR to determine factors which influenced them and correlations between the parameters and weights at determined ages. Fixed effects in the model included lambing number, sex of lamb, type of birth and month and age of lambing. The management system is semi-extensive, with the sheep at pasture during the day and imprisoned at night to protect them against predators. Means of the parameters were: Richards; A = 50.024, B = 0.647, k = 0.003, M = 17.771 and R2= 0.838; Brody; A= 52.763, B=0.885, k=0.003, R2= 0.842; Logistic; A =47.894, B=-3.895, k=0.007 and R²= 0.840. The environment influenced the growth of sheep in the region of Brasilia. The Logistic curve estimated adult weights lower than the other curves but the actual weights were better correlated with those estimated by this curve. There was no difference between the curves in terms of R2, and the error mean square was higher for the Richards curve. The negative correlation between A and k indicates that early maturing animals were less likely to reach high mature weights, compared with late maturing ones. The recommended curve for adjusting growth curves in Bergamasca sheep is the Logistic curve

    Highly sensitive C-reactive protein and male gender are independently related to the severity of coronary disease in patients with metabolic syndrome and an acute coronary event

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    Patients with metabolic syndrome are at high-risk for development of atherosclerosis and cardiovascular events. The objective of this study was to examine the major determinants of coronary disease severity, including those coronary risk factors associated with metabolic syndrome, during the early period after an acute coronary episode. We tested the hypothesis that inflammatory markers, especially highly sensitive C-reactive protein (hsCRP), are related to coronary atherosclerosis, in addition to traditional coronary risk factors. Subjects of both genders aged 30 to 75 years (N = 116) were prospectively included if they had suffered a recent acute coronary syndrome (acute myocardial infarction or unstable angina pectoris requiring hospitalization) and if they had metabolic syndrome diagnosed according to the National Cholesterol Education Program/Adult Treatment Panel III. Patients were submitted to a coronary angiography and the burden of atherosclerosis was estimated by the Gensini score. The severity of coronary disease was correlated (Spearman’s or Pearson’s coefficient) with gender (r = 0.291, P = 0.008), age (r = 0.218, P = 0.048), hsCRP (r = 0.256, P = 0.020), ApoB/ApoA ratio (r = 0.233, P = 0.041), and carotid intima-media thickness (r = 0.236, P = 0.041). After multiple linear regression, only male gender (P = 0.046) and hsCRP (P = 0.012) remained independently associated with the Gensini score. In this high-risk population, male gender and high levels of hsCRP, two variables that can be easily obtained, were associated with more extensive coronary disease, identifying patients with the highest potential of developing new coronary events.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Disciplina de CardiologiaUNIFESP, EPM, Disciplina de CardiologiaSciEL

    “Espetáculo de Luta”: a presença feminina na capoeira em Belém do Pará no final do século XIX e início do XX

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    O presente trabalho realiza reflexões referentes à presença feminina na prática da capoeira em Belém do Pará no final do século XIX e início do XX, sendo analisadas as ações desempenhadas por essas mulheres e sua atuação na capoeiragem, tendo como objetivo geral analisar a atuação feminina na capoeira no espaço urbano, frente ao modelo de comportamento proposto pelas políticas contidas no período republicano. Os objetivos específicos estão baseados em identificar as punições feitas às mulheres capoeiras e compreender como se dava sua presença no ambiente da república paraense. A metodologia utilizada neste trabalho consiste em uma abordagem qualitativa utilizando o procedimento técnico da análise documental e bibliográfica, sendo examinados relatos jornalísticos e o Código Penal de 1890, que criminalizou a capoeira. Desse modo, desenvolver o debate em torno da história social da capoeira no Pará, envolvendo as mulheres, consiste em visibilizá-las como sujeitas históricas, revelando as múltiplas dimensões sociais e de historicidade vivenciadas por elas

    DESCRITORES MORFOMÉTRICOS E QUALIDADE FISIOLÓGICA DE SEMENTES PARA SELEÇÃO DE MATRIZES DE Aspidosperma pyrifolium Mart.

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    Aspidosperma pyrifolium Mart. (Apocynaceae) is a tree species with high ecological and economic potential. Therefore, the need to select trees for producing high-quality seeds is evident. In this sense, the objective of this study was to select A. pyrifolium matrices based on the morphometric descriptors of fruits and seeds and the physiological quality of seeds from a natural population. For this, 11 A. pyrifolium trees were selected, and their fruits and seeds were submitted to biometric analysis; in addition, the physiological quality of the seeds was evaluated. The morphometric characteristics of fruits and seeds and the physiological quality of the seeds evidenced differences and variations among the seeds of the different A. pyrifolium trees, making it possible to group them according to the similarity degree. Thus, seven trees were selected as seed matrices based on superior physiological quality and genetic dissimilarity.Aspidosperma pyrifolium Mart. (Apocynaceae) é uma espécie arbórea com elevado potencial ecológico e econômico, por isso, evidencia-se a necessidade de seleção de árvores para a produção de sementes de alta qualidade. Nesse sentido, o objetivo deste estudo foi selecionar matrizes de A. pyrifolium com base nos descritores morfométricos de frutos e de sementes e na qualidade fisiológica de sementes provenientes de uma população natural. Para isso, onze árvores de A. pyrifolium foram selecionadas, cujos frutos e sementes foram submetidos à análise biométrica, bem como realizada a avaliação da qualidade fisiológica das sementes. Os caracteres morfométricos de frutos e de sementes, e a qualidade fisiológica das sementes evidenciaram diferenças e variações entre as sementes oriundas das diferentes árvores de A. pyrifolium, tornando possível agrupá-las conforme o grau de similaridade. Assim, foram selecionadas sete árvores como matrizes produtoras de sementes baseado na qualidade fisiológica superior e na maior dissimilaridade genética
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