28 research outputs found

    Peramorphosis, an evolutionary developmental mechanism in neotropical bat skull diversity

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    Background The neotropical leaf鈥恘osed bats (Chiroptera, Phyllostomidae) are an ecologically diverse group of mammals with distinctive morphological adaptations associated with specialized modes of feeding. The dramatic skull shape changes between related species result from changes in the craniofacial development process, which brings into focus the nature of the underlying evolutionary developmental processes. Results In this study, we use three鈥恉imensional geometric morphometrics to describe, quantify, and compare morphological modifications unfolding during evolution and development of phyllostomid bats. We examine how changes in development of the cranium may contribute to the evolution of the bat craniofacial skeleton. Comparisons of ontogenetic trajectories to evolutionary trajectories reveal two separate evolutionary developmental growth processes contributing to modifications in skull morphogenesis: acceleration and hypermorphosis. Conclusion These findings are consistent with a role for peramorphosis, a form of heterochrony, in the evolution of bat dietary specialists

    Reptiles of the municipality of Juiz de Fora, Minas Gerais state, Brazil

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    Eating down the food chain: generalism is not an evolutionary dead end for herbivores

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    Objeto de aprendizaje: Presentaci贸n multimediaEste recurso educativo habla acerca del tercer punto de la base triangular de la sexolog铆a, la funci贸n sexual del aparato sexual masculino.1. Introducci贸n1.1. Funci贸n del aparato sexual masculino1.1.1. Primera funci贸n1.1.2. Segunda funci贸n1.1.3. Tercera funci贸n2. Actividad de aprendizaje3. Bibliograf铆a1.0This educational resource talks about the third point of the triangular basis of sexology, the sexual function of the male sexual apparatus

    Partial purification, immobilization and preliminary biochemical characterization of lipases from Rhizomucor pusillus

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    Lipases have important applications in biotechnological processes, motivating us to produce, purify, immobilize and perform a biochemical characterization of the lipase from Rhizomucor pusillus. The fungus was cultivated by solid state fermentation producing lipolytic activity of about 0.5 U/mL(4U/g). A partial purification by gel filtration chromatography in Se-phacryl S-100 allowed obtaining a yield of about 85% and a purification factor of 5.7. Our results revealed that the purified enzyme is very stable with some significant differences in its properties when compared to crude extract. The crude enzyme extract has an optimum pH and temperature of 7.5 掳 C and 40 掳 C, respectively. After purification, a shift of the optimum pH from 7 to 8 was observed, as well as a rise in optimumtemperature to 60 掳 C and an increase in stability. The enzyme was immobilized on CNBr-Agarose and Octyl-Agarose supports, having the highest immobilization yield of 94% in the second resin. The major advantage of immobilization in hydrophobic media such as Octyl is in its hyper activation, which in this case was over 200%, a very interesting finding. Another advantage of this type of immobilization is the possibility of using the derivatives in biotechnological applications, such as in oil enriched with omega-3 as the results obtained in this study display the hydrolysis of 40% EPA and 7% DHA from sardine oil, promising results compared to the literature
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