458 research outputs found

    Efeito da suplementação alimentar no ganho de peso de ovelhas criadas em pastagem de B. brizantha.

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    A ovinocultura pode tornar-se uma atividade altamente rentável para o Amazonas, contribuindo para o abastecimento de carne no mercado local. Entretanto, há uma extrema carência de informações e tecnologia que permitam à ovinocultura uma melhor eficiência, como por exemplo sobre o uso de suplementação alimentar, prática comum no Estado do Amazonas, usando produtos de baixo custo disponíveis no mercado local. Em função disto, realizou-se um ensaio objetivando avaliar o efeito da suplementação alimentar sobre o ganho de peso de ovelhas criadas a pasto. Para tanto, dois lotes de dez ovelhas com peso médio de 27 kg foram mantidos em um sistema de pastejo rotacionado sobre B. brizantha, sendo que um deles recebeu suplementação de 300g diárias de farelo de milho (33%), farelo de trigo (33%) e casquilho de soja (33%). O GMD obtido com a suplementação foi 43% superior, comprovando a eficácia desta prática local de suplementação e permitindo sua recomendação

    Comportamento do Angiostrongylus costaricensis em planorbídeos

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    Some terrestrial mollusks are natural hosts of Angiostrongylus costaricensis. In the laboratory, this nematode can be maintained in certain planorbids, which are aquatic mollusks and intermediate hosts of Schistosoma mansoni. Mollusks can be infected with Angiostrongylus costaricensis by ingestion of or active penetration by the first-stage larvae. In this work we assessed the ability of Biomphalaria glabrata to attract first-stage larvae of A. costaricensis. Movement of the nematode larvae towards the mollusks was observed after 15 min, 30 min and 1 h. B. glabrata did not attract the first-stage larvae of A. costaricensis in any of the three intervals. The susceptibility of two populations of Biomphalaria tenagophila to infection by A. costaricensis was also determined. One population was genetically selected for the susceptibility to S. mansoni while the other was not. Third-stage larvae were recovered from the snails 30 days after exposure of the two populations to 120 first-stage larvae. All the mollusks were infected. However, a significantly higher number of third-stage larvae were recovered in mollusks not genetically selected.Alguns moluscos terrestres são hospedeiros naturais do Angiostrongylus costaricensis. No laboratório, esse nematódeo pode ser mantido em planorbídeos, que são moluscos aquáticos e hospedeiros intermediários do Schistosoma mansoni. Os moluscos podem ser infectados com A. costaricensis por ingestão ou por penetração ativa de larvas de primeiro estágio. Neste trabalho, testamos a habilidade de Biomphalaria glabrata em atrair larvas de primeiro estágio de A. costaricensis. A movimentação das larvas do nematódeo em direção aos moluscos foi observada após 15 minutos, 30 minutos e 1 hora. B. glabrata não atraiu as larvas de primeiro estágio de A. costaricensis nos três intervalos de tempo. Verificamos também a suscetibilidade de duas populações de Biomphalaria tenagophila à infecção por A. costaricensis. Uma população era selecionada geneticamente para a susceptibilidade ao S. mansoni, enquanto a outra não o era. Larvas de terceiro estágio foram recuperadas dos moluscos 30 dias após a exposição das duas populações a 120 larvas de primeiro estágio. Todos os moluscos estavam infectados. Entretanto, um número significativamente maior de larvas de terceiro estágio foi recuperado em moluscos não geneticamente selecionados.19920

    Resistência à penetração do solo em sistemas de integração lavoura-pecuária-floresta em solos de textura muito argilosa na Amazônia Central.

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    Este estudo teve como objetivo comparar a resistência à penetração do solo em áreas cultivadas intensivamente com cana-de-açúcar, sistema de integração lavoura-pecuária-floresta e a floresta primitiva

    Produção de Brachiaria brizantha cv. Xaraés em sistemas de integração lavoura-pecuária-floresta no Estado do Amazonas.

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    O objetivo desse trabalho foi avaliar a produção de uma pastagem de Brachiaria brizantha renovada por meio de um sistema de integração lavoura-pecuária. O experimento foi instalado na Estação Experimental do Distrito Agropecuário da Suframa, pertencente à Embrapa Amazônia Ocidental, localizada em Manaus-AM

    Immunoglobulin genes implicated in glioma risk

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    Both genetic and environmental factors are thought to be causal in gliomagenesis. Several genes have been implicated in glioma development, but the putative role of a major immunity-related gene complex member, immunoglobulin heavy chain γ (IGHG) has not been evaluated. Prior observations that IGHG-encoded γ marker (GM) allotypes exhibit differential sensitivity to an immunoevasion strategy of cytomegalovirus, a pathogen implicated as a promoter of gliomagenesis, has lead us to hypothesize that these determinants are risk factors for glioma. To test this hypothesis, we genotyped the IGHG locus comprising the GM alleles, specifically GM alleles 3 and 17, of 120 glioma patients and 133 controls via TaqMan® genotyping assay. To assess the associations between GM genotypes and the risk of glioma, we applied an unconditional multivariate logistic regression analysis adjusted for potential confounding variables. In comparison to subjects who were homozygous for the GM 17 allele, the GM 3 homozygotes were over twice as likely, and the GM 3/17 heterozygotes were over three times as likely, to develop glioma. Similar results were achieved when analyzed by combining the data corresponding to alleles GM 3 and GM 3/17 in a dominant model. The GM 3/17 genotype and the combination of GM 3 and GM 3/17 were found to be further associated with over 3 times increased risk for high-grade astrocytoma (grades III-IV). Allele frequency analyses also showed an increased risk for gliomas and high-grade astrocytoma in association with GM 3. Our findings support the premise that the GM 3 allele may present risk for the development of glioma, possibly by modulating immunity to cytomegalovirus

    The Emergence of Miller's Magic Number on a Sparse Distributed Memory

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    Human memory is limited in the number of items held in one's mind—a limit known as “Miller's magic number”. We study the emergence of such limits as a result of the statistics of large bitvectors used to represent items in memory, given two postulates: i) the Sparse Distributed Memory; and ii) chunking through averaging. Potential implications for theoretical neuroscience are discussed

    Cost effectiveness of outpatient lumbar discectomy

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    Background: Microdiscectomy is the most commonly performed spine surgery and the first transitioning for outpatient settings. However, this transition was never studied, in what comes to cost-utility assessment. Accordingly, this economic study aims to access the cost-effectiveness of outpatient lumbar microdiscectomy when compared with the inpatient procedure. Methods: This is a cost utility study, adopting the hospital perspective. Direct medical costs were retrieved from the assessment of 20 patients undergoing outpatient lumbar microdiscectomy and 20 undergoing inpatient lumbar microdiscectomy Quality-adjusted life-years were calculated from Oswestry Disability Index values (ODI). ODI was prospectively assessed in outpatients in pre and 3- and 6-month post-operative evaluations. Inpatient ODI data were estimated from a meta-analysis. A probabilistic sensitivity analysis was performed and incremental cost-effectiveness ratio (ICER) calculated. Results: Outpatient procedure was cost-saving in all models tested. At 3-month assessment ICER ranged from €135,753 to €345,755/QALY, higher than the predefined threshold of €60,000/QALY gained. At 6-month costs were lower and utilities were higher in outpatient, overpowering the inpatient procedure. Probabilistic sensitivity analysis showed that in 65% to 73% of simulations outpatient was the better option. The savings with outpatient were about 55% of inpatient values, with similar utility scores. No 30-day readmissions were recorded in either group. Conclusion: This is the first economic study on cost-effectiveness of outpatient lumbar microdiscectomy, showing a significant reduction in costs, with a similar clinical outcome, proving it cost-effective
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