163 research outputs found

    Diversity of seed mineral composition of Phaseolus vulgaris L. germplasm

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    A collection of 155 accessions of ancient Portuguese common beans (Phaseolus vulgaris L.) was evaluated in relation to the content of 8minerals (Zn, Cu, Fe, Mn, Ca, Mg, P and K) important for human nutrition. A high degree of variability for P, Fe, Zn, Cu, Mn and Ca was observed in the collection. Total correlation matrix analysis revealed the existence of two important sets of strong positive correlations (P 0.0001), one involving P, Fe, Zn, Cu and protein, and the other Ca and Mn. The principal component analysis showed that Zn, Fe and Cu are highly correlated to the first component (27% of variability) and Mn and Ca to the second component (22% of the variability). The high mineral variability observed in the seeds of this common bean collection could be useful for the selection of cultivars with higher nutrition value and for the improvement of seed nutrition quality traits

    CONSERVATION OF THE ORINOCO GOOSE (NEOCHEN JUBATA) IN THE MIDDLE ARAGUAIA RIVER, TOCANTINS, BRAZIL.

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    The Orinoco goose, (Neochen jubata) is a grazing herbivore of open habitats that was once widely distributed in tropical South America. Centuries of overhunting and habitat loss have reduced it to widely scattered remnant populations; it is categorized as Near Threatened globally. Within the Cerrado biome, the Middle Araguaia River houses the largest remnant population. In August 2017, a study was started to assess the situation of the Orinoco Goose in the regions of Araguaia National Park, Cantão State Park, and adjacent rice fields. We conducted counts from an aerial census (a 700 km transect), monthly boat censuses (40 km) and land censuses in rice plantations. The aircraft census counted 367 individuals in August 2017, while monthly monitoring of a stretch of the lower Javaés River over more than two years showed a seasonal population variation associated with the flood regime, with the species virtually disappearing during the flood period between January and April when river beaches are submerged. During this period, large flocks of about 1,000 Orinoco Geese were discovered not far away, concentrated in small stretches of rice plantation agro-systems in the region.  This behavioral seasonal concentration makes the species susceptible to poisoning and epizootic diseases. The findings suggest the need to re-categorize the Orinoco Goose population of the Middle Araguaia River as “Threatened” for the State of Tocantins due to the decline observed in the last 10 years, the maximum estimated population size, and the significant seasonal concentrations in a restricted area. At the same time, it is necessary to develop an action plan for its conservation in the surroundings of Ilha do Bananal, and throughout Brazil, where its threat status must be reviewed

    A hydraulic feedback loop between mesendoderm cell migration and interstitial fluid relocalization promotes embryonic axis formation in zebrafish

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    Interstitial fluid (IF) accumulation between embryonic cells is thought to be important for embryo patterning and morphogenesis. Here, we identify a positive mechanical feedback loop between cell migration and IF relocalization and find that it promotes embryonic axis formation during zebrafish gastrulation. We show that anterior axial mesendoderm (prechordal plate [ppl]) cells, moving in between the yolk cell and deep cell tissue to extend the embryonic axis, compress the overlying deep cell layer, thereby causing IF to flow from the deep cell layer to the boundary between the yolk cell and the deep cell layer, directly ahead of the advancing ppl. This IF relocalization, in turn, facilitates ppl cell protrusion formation and migration by opening up the space into which the ppl moves and, thereby, the ability of the ppl to trigger IF relocalization by pushing against the overlying deep cell layer. Thus, embryonic axis formation relies on a hydraulic feedback loop between cell migration and IF relocalization
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