Artículo de publicación ISIA high proportion of plant species is predicted to be threatened with extinction in the near future. However, the threat status of only a small number has been evaluated compared with key animal groups, rendering the magnitude and nature of the risks plants face unclear. Here we report the results of a global species assessment for the largest plant taxon evaluated to date under the International Union for Conservation of Nature (IUCN) Red List Categories and Criteria, the iconic Cactaceae (cacti). We show that cacti are among the most threatened taxonomic groups assessed to date, with 31% of the 1,478 evaluated species threatened, demonstrating the high anthropogenic pressures on biodiversity in arid lands. The distribution of threatened species and the predominant threatening processes and drivers are different to those described for other taxa. The most significant threat processes comprise land conversion to agriculture and aquaculture, collection as biological resources, and residential and commercial development. The dominant drivers of extinction risk are the unscrupulous collection of live plants and seeds for horticultural trade and private ornamental collections, smallholder livestock ranching and smallholder annual agriculture. Our findings demonstrate that global species assessments are readily achievable for major groups of plants with relatively moderate resources, and highlight different conservation priorities and actions to those derived from species assessments of key animal groupsConsejo Nacional de Ciencia y Tecnologia
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Platelets are a major peripheral reservoir of the amyloid-β protein precursor, so they have been considered as a potential biological marker of Alzheimer's disease (AD). Here, it is demonstrated that tau protein is also present in platelets and that the levels of oligomeric species of this protein could serve as a novel and reliable biological marker for AD. Blood samples were obtained from 15 AD patients and 10 paired-age controls and platelets were separated via differential centrifugation. The purity of platelets was determined by flow cytometry and microscopy and the presence of tau was determined by immunofluorescence and immunoblots with tau specific antibodies. Immunofuorescence and immunoblot patterns of platelets were positive for tau. Immunoblots also showed the presence of high molecular weight (HMW) variants of tau that appeared to correspond to oligomeric forms of the protein. The ratio of HMW tau respect to tau monomeric species was significantly higher in AD patients than controls. The present is the first description of the presence of tau in platelets. The analysis of different tau fractions in platelets could serve as a new biological marker for AD.
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