1,251 research outputs found

    Selection On Different Genes With Equivalent Functions: The Convergence Story Told By Hox Genes Along The Evolution Of Aquatic Mammalian Lineages

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    Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Convergent evolution has been a challenging topic for decades, being cetaceans, pinnipeds and sirenians textbook examples of three independent origins of equivalent phenotypes. These mammalian lineages acquired similar anatomical features correlated to an aquatic life, and remarkably differ from their terrestrial counterparts. Whether their molecular evolutionary history also involved similar genetic mechanisms underlying such morphological convergence nevertheless remained unknown. To test for the existence of convergent molecular signatures, we studied the molecular evolution of Hox genes in these three aquatic mammalian lineages, comparing their patterns to terrestrial mammals. Hox genes are transcription factors that play a pivotal role in specifying embryonic regional identity of nearly any bilateral animal, and are recognized major agents for diversification of body plans. Results: We detected few signatures of positive selection on Hox genes across the three aquatic mammalian lineages and verified that purifying selection prevails in these sequences, as expected for pleiotropic genes. Genes found as being positively selected differ across the aquatic mammalian lineages, but we identified a substantial overlap of their developmental functions. Such pattern likely resides on the duplication history of Hox genes, which probably provided different possible evolutionary routes for achieving the same phenotypic solution. Conclusions: Our results indicate that convergence occurred at a functional level of Hox genes along three independent origins of aquatic mammals. This conclusion reinforces the idea that different changes in developmental genes may lead to similar phenotypes, probably due to the redundancy provided by the participation of Hox paralogous genes in several developmental functions.16Ciencia sem Fronteiras - Atracao de Jovens Talentos CAPES [054/2012]FAPESP-Brazil [2010/52316-3]CNPq-Brazil [563232/2010-2]Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

    From Clinical Presentation to the Outcome: the Natural History of PML in a Portuguese Population of HIV Infected Patients

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    Background Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease of the central nervous system, associated with immunosuppression states. As there are only some non-published documents concerning PML in HIV infected patients in Portugal, we pretend to characterize natural history of PML infection in a population of HIV patients. Methods We retrospectively reviewed, from 1992 to 2009, PML cases in a population of 724 HIV infected patients followed in our institution. Clinical, biological, imagery features and outcomes were characterized. Results Twenty-five (3.45%) patients were identified as having PML. The mean time between HIV and PML diagnosis was 20.4 months. PML was the presentation of HIV infection in 40% of the patients, and 92% had CD4 T cell count lower than 200/mm3. Paresis was the most common clinical presentation. No specific characteristics were found in cerebrospinal fluid and JCV DNA was positive in 3 of 7 patients. MRI revealed characteristic findings. Combined antiretroviral therapy was started or changed in 96% of the patients. Neurological condition got worse in 12 patients. From the 14 deaths, 5 were directly attributed to PML progression. Follow-up was lost in 8 patients. Conclusions PML was the presentation of HIV infection in more than 1/3 of patients, frequently associated with advanced immunocompromise. MRI sensitivity to PML is high, and JCV DNA determination in CSF was not revealed to be sensible. PML diagnosis should be taken into account in HIV patients presenting any neurological symptoms, and HIV infection should be suspected when radiological findings suggest PML lesions even in previously healthy individuals

    Introdução e avaliação de forrageiras em pastagens nativas da Ilha de Marajó.

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    Resumo publicado também em: REUNIÃO ANUAL DA SOCIEDADE BRASILEIRA DE ZOOTECNIA, 36., 1999, Porto Alegre. Resumos dos trabalhos apresentados... Porto Alegre: Sociedade Brasileira de Zootecnia, 1999. p. 71

    Avaliação de forrageiras em savanas mal drenadas da Ilha de Marajó.

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    Increased rate of hair keratin gene loss in the cetacean lineage

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    Avaliação de estratégias de produção em agricultura irrigada no perímetro de irrigação do Jaíba.

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    Apresenta-se aqui o relatório de projeto de pesquisa, parcialmente financiado pelo Conselho Nacional de Desenvolvimento Científico e Tecnológico, CNPq, que teve como objetivo gerar uma base de informações para dar suporte a decisões relativas ao manejo da irrigação e ao planejamento para o perímetro de irrigação Jaíba. O relatório compreende o período de 10 de agosto de 2005 a 10 de agosto de 2007. Informações técnicas e econômicas de cinco culturas perenes e quinze anuais foram levantadas na literatura internacional, nacional e local e em relatórios dos distritos de irrigação Jaíba e Gorutuba e da Codevasf. Séries históricas de dados de clima foram obtidas na Embrapa Milho e Sorgo. Foram utilizados parâmetros hidrodinâmicos e de retenção de água do solo já determinados. Os coeficientes técnicos dos custos de produção foram obtidos no distrito de irrigação Jaíba e, para os custos dos fatores de produção, foram considerados valores médios para o Norte de Minas Gerais atualizados para de- zembro de 2006. Consideraram-se os custos de água de irrigação praticados no perímetro e os preços de venda dos produtos foram ajustados com base em uma série histórica, corrigida pelo IPCA, obtida junto aos distritos de irrigação, Emater-MG e Codevasf e preços recebidos no Ceasa-MG em diferentes épocas do ano. Os requerimentos totais de irrigação (RIT) e as produtividades relativas totais (YRT) foram obtidos mediante simulações com o modelo MCID. Posteriormente, essas informações foram empregadas nos estudos de otimização de padrão de cultivo, associados à análise de risco, na definição de coeficientes técnicos relativos à função objetivo e na definição de restrições no modelo de programação linear. Visando demonstrar a aplicação das ferramentas de otimização de padrão de cultivo e de requerimento de água, foi construído um modelo de programação linear associado à análise de risco. Para executar a análise de risco, empregou-se o modelo P-Risco, no qual algumas variáveis de entrada e de saída são consideradas de forma estocástica, tendo a elas associada uma distribuição de probabilidade de ocorrência. Para a propriedade de 19 hectares do perímetro Jaíba, o ponto de máximo valor presente líquido total foi igual a R278.394,48,ocorrendo,todavia,restric\ca~odeaˊguaemalgunsmesesnosquatroanosdocenaˊrioanalisado.Entretanto,paraumvalorpresentelıˊquidototaldeR 278.394,48, ocorrendo, todavia, restrição de água em alguns meses nos quatro anos do cenário analisado. Entretanto, para um valor presente líquido total de R 275.000,00, ou seja, 1,22% menor que o máximo, verificou-se uma redução de 11,65% no requerimento de água para as culturas. Quando foi realizada a análise de risco, com base na probabilidade de ocorrência de certas variáveis de entrada do modelo, o valor presente líquido total (VPLT), para a propriedade de 19 hectares do perímetro Jaíba, foi reduzido para R$ 211.973,71, ou seja, 24% inferior ao valor obtido para um cenário de quatro anos apenas. Além do mais, quando se trabalha com rentabilidade máxima, existe uma probabilidade de 50% de que o requerimento de irrigação total (RIT) seja superior ao valor permitido, o que poderia comprometer a sustentabilidade do empreendimento devido ao risco de escassez de água. Todavia, quando se trabalha com uma rentabilidade menor, não se verifica risco de restrição de água. Essas análises demonstram a poderosa capacidade das ferramentas propostas para o planejamento e para o auxílio à tomada de decisões em propriedades de perímetros irrigados.bitstream/CNPMS-2009-09/21155/1/Doc_69.pd

    Time-budget of horses reared for meat production: Influence of stocking density on behavioural activities and subsequent welfare

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    Horses reared for meat production can be kept in intensive breeding farms where they are housed in group pens at high stocking densities. The present study aimed to evaluate whether the expressed behaviours correlated with stocking density, and to compare their time-budget with that of wild-living horses. An ethogram of 13 mutually exclusive behavioural activities was developed. Behavioural observations were performed over a 72 h period on group pens selected on the basis of stocking density and the homogeneity of breed, age, height at the withers, and time since arriving at the farm. Scan sampling (n = 96 scans/horse/day) was used on 22 horses. The mean frequency (%) standard deviation (SD) for each behavioural activity was calculated to obtain the time-budget. The associations between time-budget and stocking density were evaluated using a bivariate analysis. The relationships were analysed by Pearson’s correlation coecient (r). Our results show that locomotion, playing, and self-grooming positively correlated with a reduction in stocking density, indicating the potential to use these behaviours as positive welfare indicators for young horses kept in group pens. The data also revealed an unusual time-budget, where the main behavioural activity expressed was standing (30.56% 6.56%), followed by feeding (30.55% 3.59%), lying (27.33% 2.05%), and locomotion (4.07% 1.06%)

    Sildenafil improves microvascular O-2 delivery-to-utilization matching and accelerates exercise O-2 uptake kinetics in chronic heart failure

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    Sperandio PA, Oliveira MF, Rodrigues MK, Berton DC, Treptow E, Nery LE, Almeida DR, Neder JA. Sildenafil improves microvascular O-2 delivery-to-utilization matching and accelerates exercise O-2 uptake kinetics in chronic heart failure. Am J Physiol Heart Circ Physiol 303: H1474-H1480, 2012. First published September 28, 2012; doi:10.1152/ajpheart.00435.2012.-Nitric oxide (NO) can temporally and spatially match microvascular oxygen (O-2) delivery (QO(2mv)) to O-2 uptake (VO2) in the skeletal muscle, a crucial adjustment-to-exercise tolerance that is impaired in chronic heart failure (CHF). To investigate the effects of NO bioavailability induced by sildenafil intake on muscle QO(2mv)-to-O-2 utilization matching and VO2 kinetics, 10 males with CHF (ejection fraction = 27 +/- 6%) undertook constant work-rate exercise (70-80% peak). Breath-by-breath VO2, fractional O-2 extraction in the vastus lateralis {similar to deoxy-genated hemoglobin + myoglobin ([deoxy-Hb + Mb]) by near-infrared spectroscopy}, and cardiac output (CO) were evaluated after sildenafil (50 mg) or placebo. Sildenafil increased exercise tolerance compared with placebo by similar to 20%, an effect that was related to faster on-and off-exercise VO2 kinetics (P 0.05). On-exercise [deoxy-Hb + Mb] kinetics were slowed by sildenafil (similar to 25%), and a subsequent response overshoot (n = 8) was significantly lessened or even abolished. in contrast, [deoxy-Hb + Mb] recovery was faster with sildenafil (similar to 15%). Improvements in muscle oxygenation with sildenafil were related to faster on-exercise VO2 kinetics, blunted oscillations in ventilation (n = 9), and greater exercise capacity (P < 0.05). Sildenafil intake enhanced intramuscular QO(2mv)-to-VO2 matching with beneficial effects on VO2 kinetics and exercise tolerance in CHF. the lack of effect on CO suggests that improvement in blood flow to and within skeletal muscles underlies these effects.Universidade Federal de São Paulo, Dept Med, Div Resp Dis, Pulm Funct & Clin Exercise Physiol Unit, BR-04020050 São Paulo, BrazilQueens Univ, Dept Med, Div Resp & Crit Care Med, Kingston, ON K7L 3N6, CanadaUniversidade Federal de São Paulo, Dept Med, Div Cardiol, BR-04020050 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Med, Div Resp Dis, Pulm Funct & Clin Exercise Physiol Unit, BR-04020050 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Med, Div Cardiol, BR-04020050 São Paulo, BrazilWeb of Scienc
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