477 research outputs found

    Intake and Digestibility of Nutrients of Corn and \u3cem\u3eStylosanthes\u3c/em\u3e Silages in Diets for Sheep

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    The low concentration of water soluble carbohydrates, the high buffering capacity and the low autochthonous population of lactic acid bacteria are limiting factors to legume ensiling. However, recent research with tropical legumes has shown that the silages presented an adequate fermentation profile (Liu et al. 2012; Silva et al. 2012; Pereira et al. 2012). Nevertheless, there are few studies on the use of stylosanthes silages cv. Campo Grande (Stylosanthes capitata + Stylosantes macrocephala) for sheep feeding. The objective of this study was to evaluate the intake and digestibility of nutrients of stylosanthes and corn silages in sheep diets

    Is evolution faster at ecotones? A test using rates and tempo of diet transitions in Neotropical Sigmodontinae (Rodentia, Cricetidae)

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    We evaluated whether evolution is faster at ecotones as niche shifts may be needed to persist under unstable environment. We mapped diet evolution along the evolutionary history of 350 sigmodontine species. Mapping was used in three new tipbased metrics of trait evolution – Transition Rates, Stasis Time, and Last Transition Time – which were spatialized at the assemblage level (aTR, aST, aTL). Assemblages were obtained by superimposing range maps on points located at core and ecotone of the 93 South American ecoregions. Using Linear Mixed Models, we tested whether ecotones have species with more changes from the ancestral diet (higher aTR), have maintained the current diet for a shorter time (lower aST), and have more recent transitions to the current diet (lower aLT) than cores. We found lower aTR, and higher aST and aLT at ecotones than at cores. Although ecotones are more heterogeneous, both environmentally and in relation to selection pressures they exert on organisms, ecotone species change little from the ancestral diet as generalist habits are necessary toward feeding in ephemeral environments. The need to incorporate phylogenetic uncertainty in tip-based metrics was evident from large uncertainty detected. Our study integrates ecology and evolution by analyzing how fast trait evolution is across space

    Fine Mapping of the Interaction between C4b-Binding Protein and Outer Membrane Proteins LigA and LigB of Pathogenic Leptospira interrogans.

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    The complement system consists of more than 40 proteins that participate in the inflammatory response and in pathogen killing. Complement inhibitors are necessary to avoid the excessive consumption and activation of this system on host cells. Leptospirosis is a worldwide zoonosis caused by spirochetes from the genus Leptospira. Pathogenic leptospires are able to escape from complement activation by binding to host complement inhibitors Factor H [FH] and C4b-binding protein (C4BP) while non-pathogenic leptospires are rapidly killed in the presence of fresh serum. In this study, we demonstrate that complement control protein domains (CCP) 7 and 8 of C4BP α-chain interact with the outer membrane proteins LcpA, LigA and LigB from the pathogenic leptospire L. interrogans. The interaction between C4BP and LcpA, LigA and LigB is sensitive to ionic strength and inhibited by heparin. We fine mapped the LigA and LigB domains involved in its binding to C4BP and heparin and found that both interactions are mediated through the bacterial immunoglobulin-like (Big) domains 7 and 8 (LigA7-8 and LigB7-8) of both LigA and LigB and also through LigB9-10. Therefore, C4BP and heparin may share the same binding sites on Lig proteins

    Fine Mapping of the Interaction between C4b-Binding Protein and Outer Membrane Proteins LigA and LigB of Pathogenic Leptospira interrogans.

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    The complement system consists of more than 40 proteins that participate in the inflammatory response and in pathogen killing. Complement inhibitors are necessary to avoid the excessive consumption and activation of this system on host cells. Leptospirosis is a worldwide zoonosis caused by spirochetes from the genus Leptospira. Pathogenic leptospires are able to escape from complement activation by binding to host complement inhibitors Factor H [FH] and C4b-binding protein (C4BP) while non-pathogenic leptospires are rapidly killed in the presence of fresh serum. In this study, we demonstrate that complement control protein domains (CCP) 7 and 8 of C4BP α-chain interact with the outer membrane proteins LcpA, LigA and LigB from the pathogenic leptospire L. interrogans. The interaction between C4BP and LcpA, LigA and LigB is sensitive to ionic strength and inhibited by heparin. We fine mapped the LigA and LigB domains involved in its binding to C4BP and heparin and found that both interactions are mediated through the bacterial immunoglobulin-like (Big) domains 7 and 8 (LigA7-8 and LigB7-8) of both LigA and LigB and also through LigB9-10. Therefore, C4BP and heparin may share the same binding sites on Lig proteins

    Map-A-Mole: greenspace area influences the presence and abundance of the European mole Talpa europaea in urban habitats

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    The European mole Talpa europaea is common across much of Britain. It has a unique fossorial lifestyle, and evidence of its presence is readily identified through the presence of characteristic molehills. Although molehills are often a common sight in urban greenspaces, moles are remarkably understudied, with very few studies to date exploring the urban ecology of moles. Here, we investigate if factors such as greenspace (largely urban parks and playing fields) area, intensity of management, distance to nearest patch, amount of time the patch had been isolated from other green patches, and the amount of urbanization (constructed surfaces) surrounding the patch, influence the distribution and abundance of urban moles. Mole signs (hills and surface runs) were counted in all discrete urban greenspaces (excluding domestic gardens and one private golf course) within an 89.5 km2 area in the UK town of Reading. We found that 17 out of 59 surveyed sites contained moles, with their presence being recorded in greenspaces with a minimum patch area of approximately 0.1 km2 (10 ha). Where present, the abundance of mole territories in the greenspaces was associated with both the area of greenspace and degree of urbanization within 150 m of the patch boundary. While the former was not surprising, the latter outcome may be a consequence of sites with an increased risk of flooding being home to fewer moles, and the surrounding area is also less likely to be built upon. This case study highlights how choices made in designing urban green infrastructure will determine which species survive in urban areas long into the future

    HISTÓRICO DA COMPOSIÇÃO DA VEGETAÇÃO ARBÓREA DO PARQUE DO IBIRAPUERA E SUA CONTRIBUIÇÃO PARA A CONSERVAÇÃO DA BIODIVERSIDADE

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    Os parques urbanos, além de importantes espaços de recreação, esportes, lazer, cultura e promover melhoria na qualidade de vida, apresentam potencial de contribuir para a biodiversidade regional. Objetivou-se discutir as modificações históricas da composição da vegetação arbórea do Parque Ibirapuera de São Paulo, SP; sua contribuição para a conservação da biodiversidade regional; e analisar as espécies arbóreas do Parque quanto ao risco de queda. Para isso, foi elaborado inventário por censo dos indivíduos arbóreos do Parque Ibirapuera. Historicamente as primeiras vegetações inseridas no Parque possuíam o papel de promover a drenagem da área com o uso de espécies arbóreas exóticas, como as do gênero Eucalyptus e Ligustrum, que hoje representam 16% e 7,29% das árvores, respectivamente. Estas representaram a maior porcentagem de espécies classificadas em risco de queda alto, 83,7%. A inserção posterior de espécies nativas no Parque contribuiu para o aumento da biodiversidade regional, atualmente apresentando 39,4% de árvores nativas brasileiras. Os resultados indicam a necessidade da contínua diversificação de árvores e arbustos com espécies nativas, pois além de contribuir para a minimização de pragas e doenças vegetais, pela manutenção da diversidade e dos processos ecológicos na paisagem urbana, poderá prevenir fatores importantes que provocam a queda de árvores

    Desempenho de bovinos em sistema de Integração Lavoura-Pecuária de longa duração.

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