43 research outputs found

    Propriedades químicas de uma Terra Roxa Estruturada influenciadas pela cobertura vegetal de inverno e pela adubação orgùnica e mineral

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    O presente trabalho teve por objetivo avaliar a influĂȘncia da cobertura vegetal de inverno, constituĂ­da de uma associação de aveia preta (Avena strigosa Schreb) com nabo forrageiro (Raphanus sativus L.), da adubação orgĂąnica com esterco de aves e da adubação mineral sobre propriedades quĂ­micas de uma Terra Roxa Estruturada do estado de Santa Catarina. As anĂĄlises foram realizadas em amostras de solo coletadas em agosto de 1994 e janeiro de 1995, nas profundidades de 0-10, 10-20 e 20-30 cm, em um experimento iniciado em 1990. Observou-se que a cobertura vegetal de inverno mostrou-se eficiente na manutenção de nutrientes, especialmente o potĂĄssio, e dos nĂ­veis de carbono orgĂąnico, dentro dos limites da camada arĂĄvel. O uso de adubo orgĂąnico proporcionou acĂșmulo de nutrientes no solo, enquanto os adubos organomineral e mineral mostraram tendĂȘncia de redução, principalmente dos nĂ­veis de potĂĄssio do solo

    Phylogenomics and the rise of the angiosperms

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    Angiosperms are the cornerstone of most terrestrial ecosystems and human livelihoods1,2. A robust understanding of angiosperm evolution is required to explain their rise to ecological dominance. So far, the angiosperm tree of life has been determined primarily by means of analyses of the plastid genome3,4. Many studies have drawn on this foundational work, such as classification and first insights into angiosperm diversification since their Mesozoic origins5,6,7. However, the limited and biased sampling of both taxa and genomes undermines confidence in the tree and its implications. Here, we build the tree of life for almost 8,000 (about 60%) angiosperm genera using a standardized set of 353 nuclear genes8. This 15-fold increase in genus-level sampling relative to comparable nuclear studies9 provides a critical test of earlier results and brings notable change to key groups, especially in rosids, while substantiating many previously predicted relationships. Scaling this tree to time using 200 fossils, we discovered that early angiosperm evolution was characterized by high gene tree conflict and explosive diversification, giving rise to more than 80% of extant angiosperm orders. Steady diversification ensued through the remaining Mesozoic Era until rates resurged in the Cenozoic Era, concurrent with decreasing global temperatures and tightly linked with gene tree conflict. Taken together, our extensive sampling combined with advanced phylogenomic methods shows the deep history and full complexity in the evolution of a megadiverse clade

    Supplementary Material for: A Novel ex vivo Mouse Mesometrium Culture Model for Investigating Angiogenesis in Microvascular Networks

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    <b><i>Background:</i></b> The development of models that incorporate intact microvascular networks enables the investigation of multicellular dynamics during angiogenesis. Our laboratory introduced the rat mesentery culture model as such a tool, which would be enhanced with mouse tissue. Since mouse mesentery is avascular, an alternative is mouse mesometrium, the connective tissue of uterine horns. The study’s objective was to demonstrate that mouse mesometrium contains microvascular networks that can be cultured to investigate multicellular dynamics during angiogenesis. <b><i>Methods:</i></b> Harvested mesometrium tissues from C57Bl/6 female mice were cultured in media with serum for up to 7 days. PECAM, NG2, αSMA, and LYVE-1 labeling identified endothelial cells, pericytes, smooth muscle cells, and lymphatic endothelial cells, respectively.<b><i> Results:</i></b> These cells comprised microvascular networks with arterioles, venules, and capillaries. Compared to day 0, capillary sprouts per vascular length were increased by 3 and 5 days in culture (day 0, 0.08 ± 0.01; day 3, 3.19 ± 0.78; day 5, 2.49 ± 0.05 sprouts/mm; <i>p</i> < 0.05). Time-lapse imaging of cultured tissues from FlkEGFP mice showcases the use of the model for lineage studies. The impact is supported by the identification of endothelial cell jumping from one sprout to another. <b><i>Conclusion:</i></b> These results introduce a novel culture model for investigating multicellular dynamics during angiogenesis in real-time ex vivo microvascular networks
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