7,675 research outputs found

    Gravitational Waves from Wobbling Pulsars

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    The prospects for detection of gravitational waves from precessing pulsars have been considered by constructing fully relativistic rotating neutron star models and evaluating the expected wave amplitude hh from a galactic source. For a "typical" neutron matter equation of state and observed rotation rates, it is shown that moderate wobble angles may render an observable signal from a nearby source once the present generation of interferometric antennas becomes operative.Comment: PlainTex, 7 pp. , no figures, IAG/USP Rep. 6

    Genetic variation and correlation of agronomic traits in meadow bromegrass (Bromus riparius Rehm) clones.

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    Meadow bromegrass (Bromus riparius Rehm.) is a recently introduced pasture grass in western Canada. Its leafy production and rapid regrowth have made it a major grass species for pasturing beef animals in this region. As relatively little breeding work kas been done on this species, there is little information on its breeding behaviour. The main objective of this study was to estimate total genetic variability, broad-sense heritability, phenotypic and genetic correlations. Forty-four meadow bromegrass clones were evaluated for agronomic characters. Genetic variation for dry matter yield, seed yield, fertility index, harvest index, plant height, plant spread, crude protein, neutral de ter gent fiber and acid de ter gent fiber, was significant. Broad-sense heritability estimates exceeded 50% for all characters. Heritability estimates were at least 3.5 times greater than their standard errors. Phenotypic and genetic correlation between all possible characters were measured There was general agreement in both sign and magnitude between genetic and phenotypic correlations. Correlations between the different characters demonstrated that it is possible to simultaneously improve seed and forage yield. Based on the results, it appears that the development of higher yielding cultivars with higher crude protein, and lower acid and neutral detergent fibers concentration should be possible

    Efeito do sombreamento no crescimento de mudas de copaĆ­ba (Copaifera sp.).

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    A copaĆ­ba Ć© uma Ć”rvore com grande potencial medicinal, pela produĆ§Ć£o de seu Ć³leo-resina indicado para o controle de inflamaƧƵes em geral, como antissĆ©ptico e cicatrizante. Estudos sobre a produĆ§Ć£o de mudas dessa espĆ©cie sĆ£o escassos. O presente estudo objetivou avaliar a influĆŖncia de diferentes nĆ­veis de sombreamento no desenvolvimento inicial de mudas de copaĆ­ba (CopaĆ­fera sp). O experimento foi conduzido no viveiro do Campo experimental da Embrapa Acre. Os tratamentos foram compostos por cinco nĆ­veis de sombreamento (pleno sol, 20%, 30%, 50% e 75%), obtidos com telas sombrite com as referidas capacidades de retenĆ§Ć£o da radiaĆ§Ć£o solar. O delineamento experimental utilizado foi de blocos ao acaso, com seis repetiƧƵes e oito plantas por unidade amostral. Aos 10 meses apĆ³s a semeadura, foram avaliadas as seguintes variĆ”veis: diĆ¢metro do coleto, diĆ¢metro da copa, altura e matĆ©ria seca total das plantas. Observou-se diferenƧa significativa para todas as variĆ”veis analisadas. O crescimento das mudas de copaĆ­ba foi modificado pela intensidade de sombreamento. Todas as variĆ”veis avaliadas foram afetadas significativamente (p<0,05) pelo nĆ­vel de sombreamento incidente nas plantas. Tanto o excesso de sombreamento como o de radiaĆ§Ć£o solar foram prejudiciais ao crescimento das plantas. Sombreamentos em torno de 43 a 53% proporcionaram os melhores resultados paras as variĆ”veis estudadas (diĆ¢metro do coleto, massa seca da parte aĆ©rea e massa seca total. Pelos resultados obtidos, conclui-se que mudas de copaĆ­ba (Copaifera sp.) necessitam de sombra, sendo um sombreamento de 50% o recomendado para a produĆ§Ć£o de mudas desta espĆ©cie, em funĆ§Ć£o da disponibilidade no mercado de tela sombrite com essa retenĆ§Ć£o de luminosidade

    Murcha-de-Phytomonas do coqueiro: uma ameaƧa Ơ cultura no Amazonas.

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    OcorrĆŖncia. Sintomas. DisseminaĆ§Ć£o. Controle. Controle dos insetos vetores.bitstream/item/122321/1/Folder-murcha-de-phytomonas.pd
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