328 research outputs found

    Muscle power in basketball and volleyball players: relationship between isokinetic dynamometry and vertical jump

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    The aims of this study were: 1) to determine the anthropometric characteristics and body compositon of players; 2) to evaluate the maximal muscle power of the knee extensors muscles with the isokinetic dynamometry; 3) to determine the relationships between the test of isokinetic power and the vertical jum p test; 4) to compare the results between sports. A sample of 12 basketball players and 13 volleyball players was evaluated in several anthropometric measures and in two tests of muscle power. Body composition was determined through the equation by Jackson & Pollock (1978). Vertical jum p test was made without the arm movements, and the isokinetic muscle power test of the knee extensors was made in four speeds: 60, 180, 240 and 300°/sec.The results showed that the basketball players were taller, heavier and fatter than the volleyball players. There were no significant diferences in power output. When power was related to body weight, volleyball players showed higher values in the vertical jum p test and the isokinetic power test at 60°/sec. and in the vertical jump test when corrected by lean body mass. Relationships between maximal power tests showed from moderate to high degree between isokinetic power test at 180 and 300°/sec. and the vertical jum p test for basketball players. Volleyball players showed similar results at 180 and 300°/sec. Similar results were found when tests were corrected for body weight and lean body mass for basketball players, but in volleyball players relationships were from low to moderateOs objetivos do estudo foram: 1) determinar as características antropométricas e a composição corporal dos jogadores, 2) avaliar a potência máxima dos músculos extensores do joelho com a dinamometria isocinética, 3) verificar a relação entre o teste isocinético e o teste de salto vertical e 4) comparar os dois grupos de jogadores. Uma amostra de 12 jogadores de basquetebol e 13 de voleibol foi submetida a uma avaliação antropométrica e dois testes de potência muscular. A composição corporal foi calculada a partir da equação de Jackson & Pollock (1978). O teste de salto vertical foi realizado sem o auxílio dos membros superiores e a dinamometria isocinética executada no movimento de extensão do joelho às velocidades de 60, 180, 240 e 300°/seg. Nos jogadores de basquetebol foram encontrados valores mais altos para estatura peso e quantidade de gordura comparados com os voleibolistas. Os dois grupos apresentaram desempenho neuromuscular semelhante em termos absolutos. Relativo ao peso corporal os voleibolistas foram superiores no salto vertical e na potência à 60°/seg. e também no salto vertical relativo à massa magra. Na relação entre os dois testes em termos absolutos, correlações moderadas para altas foram encontradas à 180 e 300°/seg. para os jogadores de basquete e 180 e 240°/seg. para os de voleibol. Resultados semelhantes ocorreram nos praticantes de basquetebol relativo ao peso corporal e a massa magra, contudo, para os voleibolistas as relações foram de baixas para moderada

    Evolutionary Responses of a Reef-building Coral to Climate Change at the End of the Last Glacial Maximum

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    Climate change threatens the survival of coral reefs on a global scale, primarily through mass bleaching and mortality as a result of marine heatwaves. While these short-term effects are clear, predicting the fate of coral reefs over the coming century is a major challenge. One way to understand the longer-term effect of rapid climate change is to examine the response of coral populations to past climate shifts. Coastal and shallow-water marine ecosystems such as coral reefs have been reshaped many times by sea-level changes during the Pleistocene, yet few studies have directly linked this with its consequences on population demographics, dispersal, and adaptation. Here we use powerful analytical techniques, afforded by haplotype-phased whole-genomes, to establish such links for the reef-building coral, Acropora digitifera. We show that three genetically distinct populations are present in northwestern Australia, and that their rapid divergence since the last glacial maximum (LGM) can be explained by a combination of founder-effects and restricted gene flow. Signatures of selective sweeps, too strong to be explained by demographic history, are present in all three populations and overlap with genes that show different patterns of functional enrichment between inshore and offshore habitats. In contrast to rapid divergence in the host, we find that photosymbiont communities are largely undifferentiated between corals from all three locations, spanning almost 1000 km, indicating that selection on host genes, and not acquisition of novel symbionts, has been the primary driver of adaptation for this species in northwestern Australia

    Perceptron capacity revisited: classification ability for correlated patterns

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    In this paper, we address the problem of how many randomly labeled patterns can be correctly classified by a single-layer perceptron when the patterns are correlated with each other. In order to solve this problem, two analytical schemes are developed based on the replica method and Thouless-Anderson-Palmer (TAP) approach by utilizing an integral formula concerning random rectangular matrices. The validity and relevance of the developed methodologies are shown for one known result and two example problems. A message-passing algorithm to perform the TAP scheme is also presented

    Metal Hydrides and Related Materials - Energy Carriers for Novel Hydrogen and Electrochemical Storage

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    The seventh edition of the International Renewable and Sustainable Energy Conference (IRSEC) was held in Agadir (Sofitel Royal Bay, November 27–30, Morocco) under the Program Chair of Prof. Ahmed Ennaoui (IRESEN). IRSEC, as one of the biggest conferences in north Africa, aims at creating an international forum to facilitate discussions and exchanges in all aspects of renewable and sustainable energy. This Viewpoint will summarize the scientific presentations and stimulated discussions during the Special Session (November 28–29) on Metal Hydrides’ Energy covering topics of metal hydrides and energy related issues for innovative processes and technologies, with a focus on magnesium-based hydrides, intermetallic hydrides, complex and melt hydrides, porous materials, and thin films

    Formyltetrahydrofolate Synthetase Gene Diversity in the Guts of Higher Termites with Different Diets and Lifestyles

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    In this study, we examine gene diversity for formyl-tetrahydrofolate synthetase (FTHFS), a key enzyme in homoacetogenesis, recovered from the gut microbiota of six species of higher termites. The "higher" termites (family Termitidae), which represent the majority of extant termite species and genera, engage in a broader diversity of feeding and nesting styles than the "lower" termites. Previous studies of termite gut homoacetogenesis have focused on wood-feeding lower termites, from which the preponderance of FTHFS sequences recovered were related to those from acetogenic treponemes. While sequences belonging to this group were present in the guts of all six higher termites examined, treponeme-like FTHFS sequences represented the majority of recovered sequences in only two species (a wood-feeding Nasutitermes sp. and a palm-feeding Microcerotermes sp.). The remaining four termite species analyzed (a Gnathamitermes sp. and two Amitermes spp. that were recovered from subterranean nests with indeterminate feeding strategies and a litter-feeding Rhynchotermes sp.) yielded novel FTHFS clades not observed in lower termites. These termites yielded two distinct clusters of probable purinolytic Firmicutes and a large group of potential homoacetogens related to sequences previously recovered from the guts of omnivorous cockroaches. These findings suggest that the gut environments of different higher termite species may select for different groups of homoacetogens, with some species hosting treponeme-dominated homoacetogen populations similar to those of wood-feeding, lower termites while others host Firmicutes-dominated communities more similar to those of omnivorous cockroaches

    Mapeamento do uso atual e cobertura vegetal dos solos do Estado do Rio de Janeiro.

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    O conhecimento do uso atual e cobertura do solo é imprescindível em qualquer projeto de caracterização e monitoramento ambientais, permitindo demarcar os diferentes usos da terra e vegetação, bem como subsidiar o planejamento e gestão ambientais. O presente trabalho abrange a totalidade do Estado do Rio de Janeiro, compreendido entre os meridianos 410 e 450 de longitude Oeste e os paralelos 200 30º e 230 30º de latitude Sul, estendendo-se por aproximadamente 44.000 km2. Tem como objetivo inventariar e mapear o estado atual da ocupação dos solos, distinguindo e quantificando os principais tipos de uso do solo e de cobertura vegetal, apresentados numa escala generalizada de 1:250.000. Para tal, fez-se um mapeamento preliminar com base nos padrões espectrais das imagens de satélite Landsat ETM7+, cedidas pela EMATER-RJ, utilizando-se de diferentes algoritmos de classificação espectral. Durante a elaboração da versão final do Mapa de Uso Atual e Cobertura Vegetal dos Solos do Estado do Rio de Janeiro, foram viagens de verificação in situ a fim de esclarecer dúvidas e subsidiar ajustes e modificações posteriores. O trabalho de pré-processamento, interpretação e classificação das imagens para a produção e edição final do Mapa de Uso Atual e Cobertura Vegetal realizou-se no período de março de 2002 a fevereiro de 2003, pelas equipes técnicas da CPRM (Serviço Geológico Brasileiro), Divisão de Geoprocessamento - DIGEOP, Departamento de Informações Institucionais (DEINF) e o Laboratório de Geoinformação da Embrapa Solos. Foram identificadas e mapeadas 13 grandes classes de uso e ocupação do solo, algumas delas subdivididas em tipos, assim classificadas e distribuídas: 1 - Mata Atlântica (Remanescente/Secundária e Ciliar); 2 - Mangue (Mangue e Mangue Degradado); 3 - Restinga; 4 - Pecuária (Pastagem Plantada e Campo / Pastagem em Zona Úmida); 5 - Agricultura; 6 - Reflorestamento; 7 - Afloramento de Rocha; 8 - Solo Exposto; 9 - Corpo d'Água; 10 - Salina; 11 - Extração de Areia / Mineração; 12 - Praia e Duna; 13 - Área Urbana.bitstream/CNPS/11606/1/bpd22_2003_mapeamento_rj.pd

    Draft Genome of the Pearl Oyster Pinctada fucata: A Platform for Understanding Bivalve Biology

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    The study of the pearl oyster Pinctada fucata is key to increasing our understanding of the molecular mechanisms involved in pearl biosynthesis and biology of bivalve molluscs. We sequenced ∼1150-Mb genome at ∼40-fold coverage using the Roche 454 GS-FLX and Illumina GAIIx sequencers. The sequences were assembled into contigs with N50 = 1.6 kb (total contig assembly reached to 1024 Mb) and scaffolds with N50 = 14.5 kb. The pearl oyster genome is AT-rich, with a GC content of 34%. DNA transposons, retrotransposons, and tandem repeat elements occupied 0.4, 1.5, and 7.9% of the genome, respectively (a total of 9.8%). Version 1.0 of the P. fucata draft genome contains 23 257 complete gene models, 70% of which are supported by the corresponding expressed sequence tags. The genes include those reported to have an association with bio-mineralization. Genes encoding transcription factors and signal transduction molecules are present in numbers comparable with genomes of other metazoans. Genome-wide molecular phylogeny suggests that the lophotrochozoan represents a distinct clade from ecdysozoans. Our draft genome of the pearl oyster thus provides a platform for the identification of selection markers and genes for calcification, knowledge of which will be important in the pearl industry

    Evolutionary Responses of a Reef-building Coral to Climate Change at the End of the Last Glacial Maximum

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    Climate change threatens the survival of coral reefs on a global scale, primarily through mass bleaching and mortality as a result of marine heatwaves. While these short-term effects are clear, predicting the fate of coral reefs over the coming century is a major challenge. One way to understand the longer-term effect of rapid climate change is to examine the response of coral populations to past climate shifts. Coastal and shallow-water marine ecosystems such as coral reefs have been reshaped many times by sea-level changes during the Pleistocene, yet few studies have directly linked this with its consequences on population demographics, dispersal, and adaptation. Here we use powerful analytical techniques, afforded by haplotype-phased whole-genomes, to establish such links for the reef-building coral, Acropora digitifera. We show that three genetically distinct populations are present in northwestern Australia, and that their rapid divergence since the last glacial maximum (LGM) can be explained by a combination of founder-effects and restricted gene flow. Signatures of selective sweeps, too strong to be explained by demographic history, are present in all three populations and overlap with genes that show different patterns of functional enrichment between inshore and offshore habitats. In contrast to rapid divergence in the host, we find that photosymbiont communities are largely undifferentiated between corals from all three locations, spanning almost 1000 km, indicating that selection on host genes, and not acquisition of novel symbionts, has been the primary driver of adaptation for this species in northwestern Australia
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