31 research outputs found

    O princípio da autonomia na universidade brasileira: sentidos em disputa

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    O princípio da autonomia tem estado no centro das discussões desde a criação das primeiras universidades. Os tensionamentos têm sido motivados, em geral, pelas disputas presentes no interior da sociedade e do Estado. O objetivo deste texto é apresentar os resultados de um estudo sobre a autonomia na tradição universitária brasileira. A pesquisa evidenciou, entre outros aspectos, uma estreita correlação entre democracia e autonomia

    On Fermat's principle for causal curves in time oriented Finsler spacetimes

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    In this work, a version of Fermat's principle for causal curves with the same energy in time orientable Finsler spacetimes is proved. We calculate the secondvariation of the {\it time arrival functional} along a geodesic in terms of the index form associated with the Finsler spacetime Lagrangian. Then the character of the critical points of the time arrival functional is investigated and a Morse index theorem in the context of Finsler spacetime is presented.Comment: 20 pages, minor corrections, references adde

    Maximal lactate steady state in swimming tethered

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    This study investigated whether aerobic capacity (AC) in tethered swimming corresponds to maximal lactate steady state (MLSS) and its correlation with 30 min (V30) and 400m (V400) free swimming velocity. Twenty-five swimmers were submitted to an incremental tethered swimming test (ITS) with each stage lasting 3 minutes, initial load 20N, with 10N increments and a 30s interval to collect blood samples and lactatemia ([La-]). The abrupt increase in [La-] against force (F) corresponded to AC (ACBI). The points obtained for [La-] against force (N) were adjusted with an exponential curve model to determine AC corresponding to 3.5mmol.l-1 (AC3.5) and 4.0mmol.l-1 (AC4.0). Later swimmers performed maximum exercise for 30 minutes (V30) and 400m (V400) in free swimming. After one week, nine swimmers performed three random 30 minute tethered swimming exercises with 90%, 100%, and 110% intensity ACBI MLSS. Comparisons between ACs (AC3.5, AC4.0, and ACBI) were made by the one-way Anova test. Pearson correlation was used for possible correlations between ACs and between ACs and V30 and V400 (p0.91) and V400 (r\u3e0.63). We can conclude that ACBI corresponds to MLSS and both individually determined. AC and from the fixed lactate concentrations (3.5 and 4mM) can be used to predict mean 30 minute and 400m free swimming velocity

    Determination of Force Corresponding to Maximal Lactate Steady State in Tethered Swimming

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    The main aim of the present investigation was to verify if the aerobic capacity (AC) measured in tethered swimming corresponds to the maximal lactate steady state (MLSS) and its correlation with 30 min and 400m free style swimming. Twenty-five swimmers were submitted to an incremental tethered swimming test (ITS) with an initial load of 20N and increments of 10N each 3min. After each stage of 3min, the athletes had 30s of interval to blood sample collections that were used to measure blood lactate concentrations ([La-]). The ACBI was determined by the abrupt increase in [La-] versus force (F). The points obtained between [La-] versus force (N) were adjusted by an exponential curve model to determine AC corresponding to 3.5mmol.l-1 (AC3.5) and 4.0mmol.l-1 (AC4.0). After these procedures, the swimmers performed maximal efforts of 30min and 400m in free style swimming. We used the distance performed in 30min and the time performed in 400m to calculate the median velocities (i.e. V30 and V400) of these protocols. After one week, in order to measure the MLSS, nine athletes performed three 30-min tethered swimming efforts with intensities of 90, 100, and 110% of ACBI. The ANOVA one-way was used to compare the ACBI, AC3.5 and AC4.0. Correlations between ACs, and between ACs and V30 and V400 (p\u3c0.05) were determined using the Pearson’s correlation coefficient. The intensity corresponding to 100% of ACBI was similar to the MLSS. It was observed significant correlations of the aerobic capacities (i.e. ACBI, AC3.5 and AC4.0) with V30 (r\u3e0.91) and V400 (r\u3e0.63). According to our results, it is possible to conclude that the ACBI corresponds to the MLSS, and both the AC - individually determined - and the AC - determined using fixed blood lactate concentrations of 3.5 and 4.0mmol.l-1 - can be used to predict the mean velocity of 30min and 400m in free style swimming. In addition to that, the tethered swimming system can be used for aerobic development in places where official sized swimming pools are not available, such as rehabilitation clinics and health clubs

    Influência da fonte de carbono nas propriedades de híbridos Ni/Carbono preparados por carbonização hidrotérmica e tratamento térmico e utilizados como suportes para eletrocatalisadores PtRu/C

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    Neste trabalho, híbridos Ni/Carbono foram preparados em duas etapas (carbonização hidrotérmica e tratamento térmico a 900 °C sob argônio) a partir de diferentes fontes de carbono: glicose, amido e celulose. Eletrocatalisadores PtRu/C foram preparados pelo método da redução por álcool utilizando os híbridos como suportes. Os materiais foram caracterizados por espectroscopia por energia dispersiva de raios-X (EDX), análise termogravimétrica (TGA), espectroscopia no infravermelho com transformada de Fourier (FTIR), isotermas de B.E.T., difração de raios-X (DRX), microscopia eletrônica de transmissão (TEM) e voltametria cíclica em meio ácido. A eletro-oxidação do metanol foi estudada por cronoamperometria. O eletrocatalisador PtRu/C preparado utilizando o híbrido sintetizado a partir da celulose apresentou uma eletroatividade levemente superior aos demais materiais obtidos.Palavras-chave: Metanol. Célula a combustível. Carboidratos.

    Chronic alcohol administration alters metabolomic profile of murine bone marrow

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    IntroductionPeople with hazardous alcohol use are more susceptible to viral, bacterial, and fungal infections due to the effect of alcohol on immune system cell function. Metabolized ethanol reduces NAD+ to NADH, affecting critical metabolic pathways. Here, our aim was to investigate whether alcohol is metabolized by bone marrow cells and if it impacts the metabolic pathways of leukocyte progenitor cells. This is said to lead to a qualitative and quantitative alteration of key metabolites which may be related to the immune response.MethodsWe addressed this aim by using C57BL/6 mice under chronic ethanol administration and evaluating the metabolomic profile of bone marrow total cells by gas chromatography–coupled mass spectrometry (GC–MS).ResultsWe identified 19 metabolites. Our data demonstrated that chronic ethanol administration alters the metabolomic profile in the bone marrow, resulting in a statistically diminished abundance of five metabolites in ethanol-treated animals: uracil, succinate, proline, nicotinamide, and tyrosine.DiscussionOur results demonstrate for the first time in the literature the effects of alcohol consumption on the metabolome content of hematopoietic tissue and open a wide range of further studies to investigate mechanisms by which alcohol compromises the cellular function of the immune system

    Age-Related Metabolic Pathways Changes in Dental Follicles: A Pilot Study

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    Aging is not a matter of choice; it is our fate. The “time-dependent functional decline that affects most living organisms” is coupled with several alterations in cellular processes, such as cell senescence, epigenetic alterations, genomic instability, stem cell exhaustion, among others. Age-related morphological changes in dental follicles have been investigated for decades, mainly motivated by the fact that cysts and tumors may arise in association with unerupted and/or impacted teeth. The more we understand the physiology of dental follicles, the more we are able to contextualize biological events that can be associated with the occurrence of odontogenic lesions, whose incidence increases with age. Thus, our objective was to assess age-related changes in metabolic pathways of dental follicles associated with unerupted/impacted mandibular third molars from young and adult individuals. For this purpose, a convenience sample of formalin-fixed paraffin-embedded (FFPE) dental follicles from young (<16 y.o., n = 13) and adult (>26 y.o., n = 7) individuals was selected. Samples were analyzed by high-performance liquid chromatography-mass spectrometry (HPLC-MS)-based untargeted metabolomics. Multivariate and univariate analyses were conducted, and the prediction of altered pathways was performed by mummichog and Gene Set Enrichment Analysis (GSEA) approaches. Dental follicles from young and older individuals showed differences in pathways related to C21-steroid hormone biosynthesis, bile acid biosynthesis, galactose metabolism, androgen and estrogen biosynthesis, starch and sucrose metabolism, and lipoate metabolism. We conclude that metabolic pathways differences related to aging were observed between dental follicles from young and adult individuals. Our findings support that similar to other human tissues, dental follicles associated with unerupted tooth show alterations at a metabolic level with aging, which can pave the way for further studies on oral pathology, oral biology, and physiology

    O goleiro de handebol

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    O goleiro de handebol tem como função principal à defesa da meta, sendo incumbido também de orientar seus companheiros e participar das ações ofensivas de seu time. Os professores e/ou treinadores da modalidade têm a responsabilidade de estimular os jovens a ocupar esta posição, sendo para isto necessário que estes detenham o conhecimento das suas principais características. Por intermédio de uma pesquisa bibliográfica, objetivou-se nesse estudo delimitar o papel do goleiro de handebol, abordando suas principais características físicas, motoras, técnicas, táticas e psicológicas. Dentre os atributos físicos relevantes para a posição são destacados as características antropométricas (estatura e envergadura) e as capacidades motoras (velocidade, coordenação e destreza, flexibilidade, força, potência e resistência.). No âmbito técnico-tático os elementos preponderantes são: deslocamentos, posicionamento, postura e as defesas (em bolas altas, médias e baixas). E por fim, destaca-se a coragem, a calma, a concentração, a decisão e o estilo como características psicológicas fundamentais para os goleiros de handebol. Embora o treinamento específico para goleiro seja de grande importância, os jovens que almejam atuar nessa posição devem receber uma formação variada e ampla antes da especialização. Nos processos de aprendizagem inicial, por volta dos 13-14 anos de idade, alguns cuidados merecem destaque como: não fazer da posição um lugar para castigos e nem utilizá-la como recurso para absorver alunos pouco habilidosos
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