1,102 research outputs found

    Evaluation of hypoglycemic potential and pre-clinical toxicology of Morus nigra L. (Moraceae)

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    The hypoglycemic potential of crude ethanolic extract of leaves (CEE-Mn) of the Morus nigra L. (Moraceae) was evaluated in normoglycemic rats. CEE-Mn (200 and 400 mg/kg) and metformin (500 mg/kg) were tested on the glucose tolerance oral test. The acute toxicity of CEE-Mn was performed 2.0 g/kg intraperitoneally and 5.0 g/kg orally in Swiss mice. Blood was removed after seven days for laboratory analysis of hematological and biochemical parameters. In the glucose tolerance oral test, only metformin was able to reduce the glucose-induced hyperglycemia. Regarding acute toxicity no mortality and no toxicity signs were observed, indicating low toxicity of the extract. In the evaluation of hematological and biochemical parameters no alteration was observed. In conclusion, the CEE-Mn can be considered of low toxicity but did not produce the expected hypoglycemic effect in the model used.Colegio de Farmacéuticos de la Provincia de Buenos Aire

    Geographic patterns of tree dispersal modes in Amazonia and their ecological correlates

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    Aim: To investigate the geographic patterns and ecological correlates in the geographic distribution of the most common tree dispersal modes in Amazonia (endozoochory, synzoochory, anemochory and hydrochory). We examined if the proportional abundance of these dispersal modes could be explained by the availability of dispersal agents (disperser-availability hypothesis) and/or the availability of resources for constructing zoochorous fruits (resource-availability hypothesis). Time period: Tree-inventory plots established between 1934 and 2019. Major taxa studied: Trees with a diameter at breast height (DBH) ≥ 9.55 cm. Location: Amazonia, here defined as the lowland rain forests of the Amazon River basin and the Guiana Shield. Methods: We assigned dispersal modes to a total of 5433 species and morphospecies within 1877 tree-inventory plots across terra-firme, seasonally flooded, and permanently flooded forests. We investigated geographic patterns in the proportional abundance of dispersal modes. We performed an abundance-weighted mean pairwise distance (MPD) test and fit generalized linear models (GLMs) to explain the geographic distribution of dispersal modes. Results: Anemochory was significantly, positively associated with mean annual wind speed, and hydrochory was significantly higher in flooded forests. Dispersal modes did not consistently show significant associations with the availability of resources for constructing zoochorous fruits. A lower dissimilarity in dispersal modes, resulting from a higher dominance of endozoochory, occurred in terra-firme forests (excluding podzols) compared to flooded forests. Main conclusions: The disperser-availability hypothesis was well supported for abiotic dispersal modes (anemochory and hydrochory). The availability of resources for constructing zoochorous fruits seems an unlikely explanation for the distribution of dispersal modes in Amazonia. The association between frugivores and the proportional abundance of zoochory requires further research, as tree recruitment not only depends on dispersal vectors but also on conditions that favour or limit seedling recruitment across forest types

    Geography and ecology shape the phylogenetic composition of Amazonian tree communities

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    Aim: Amazonia hosts more tree species from numerous evolutionary lineages, both young and ancient, than any other biogeographic region. Previous studies have shown that tree lineages colonized multiple edaphic environments and dispersed widely across Amazonia, leading to a hypothesis, which we test, that lineages should not be strongly associated with either geographic regions or edaphic forest types. Location: Amazonia. Taxon: Angiosperms (Magnoliids; Monocots; Eudicots). Methods: Data for the abundance of 5082 tree species in 1989 plots were combined with a mega-phylogeny. We applied evolutionary ordination to assess how phylogenetic composition varies across Amazonia. We used variation partitioning and Moran\u27s eigenvector maps (MEM) to test and quantify the separate and joint contributions of spatial and environmental variables to explain the phylogenetic composition of plots. We tested the indicator value of lineages for geographic regions and edaphic forest types and mapped associations onto the phylogeny. Results: In the terra firme and várzea forest types, the phylogenetic composition varies by geographic region, but the igapó and white-sand forest types retain a unique evolutionary signature regardless of region. Overall, we find that soil chemistry, climate and topography explain 24% of the variation in phylogenetic composition, with 79% of that variation being spatially structured (R2^{2} = 19% overall for combined spatial/environmental effects). The phylogenetic composition also shows substantial spatial patterns not related to the environmental variables we quantified (R2^{2} = 28%). A greater number of lineages were significant indicators of geographic regions than forest types. Main Conclusion: Numerous tree lineages, including some ancient ones (>66 Ma), show strong associations with geographic regions and edaphic forest types of Amazonia. This shows that specialization in specific edaphic environments has played a long-standing role in the evolutionary assembly of Amazonian forests. Furthermore, many lineages, even those that have dispersed across Amazonia, dominate within a specific region, likely because of phylogenetically conserved niches for environmental conditions that are prevalent within regions

    Search for top squark pair production in pp collisions at root s=13 TeV using single lepton events

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    Search for supersymmetry in events with photons and missing transverse energy in pp collisions at 13 TeV

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    Multiplicity and rapidity dependence of strange hadron production in pp, pPb, and PbPb collisions at the LHC

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    Search for narrow resonances in dilepton mass spectra in proton-proton collisions at root s=13 TeV and combination with 8 TeV data

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    Search for heavy gauge W ' bosons in events with an energetic lepton and large missing transverse momentum at root s=13TeV

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    Search for anomalous Wtb couplings and flavour-changing neutral currents in t-channel single top quark production in pp collisions at root s=7 and 8 TeV

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