710 research outputs found

    The end of an entire biome? World's largest wetland, the Pantanal, is menaced by the Hidrovia project which is uncertain to sustainably support large-scale navigation

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    The resurgent navigation project known as the Hidrovia Paraguay-Paran√° threatens the integrity of the Pantanal, the world's largest wetland, which is considered a biome of its own. Intensive barge navigation is intended to transport crops (soybean, sugar, corn) and cement, iron and manganese from areas of production in Brazil, Paraguay and Bolivia to the oceanic ports of the Plata River. This short communication assembles the information available on the potential impacts of the planned deepening of the natural channel of the Paraguay River in its ~700 km-long upper section. These river channel alterations would disconnect the river from its floodplain, shorten the inundation period, and shrink the wetland area, resulting in severe degradation of the globally outstanding biological and cultural diversity of the Pantanal. The river sediments are mostly sandy and would require perpetual dredging. The reaches needing the most intensive dredging are those of the highest ecological value, protected as a National Park, UNESCO World Heritage and Biosphere Reserves, and various Indigenous reserves and Ramsar sites. Climate change is projected to increase the occurrence of low water periods. Between 2019 and 2021, navigation was impossible even in the already-deepened reaches of the Paraguay River between Corumb√° and Asuncion during long periods of the year. Thus, despite considerable financial and technical efforts, the success of the navigation project is doubtful, whereas enormous environmental, cultural, and social impacts can be anticipated. For these reasons, the Brazilian government had already turned down the project in 2000. We suggest alternative, less impactful modes of transport of commodities, e.g., via railway

    Multiancestry analysis of the HLA locus in Alzheimer’s and Parkinson’s diseases uncovers a shared adaptive immune response mediated by HLA-DRB1*04 subtypes

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    Across multiancestry groups, we analyzed Human Leukocyte Antigen (HLA) associations in over 176,000 individuals with Parkinson‚Äôs disease (PD) and Alzheimer‚Äôs disease (AD) versus controls. We demonstrate that the two diseases share the same protective association at the HLA locus. HLA-specific fine-mapping showed that hierarchical protective effects of HLA-DRB1*04 subtypes best accounted for the association, strongest with HLA-DRB1*04:04 and HLA-DRB1*04:07, and intermediary with HLA-DRB1*04:01 and HLA-DRB1*04:03. The same signal was associated with decreased neurofibrillary tangles in postmortem brains and was associated with reduced tau levels in cerebrospinal fluid and to a lower extent with increased Aő≤42. Protective HLA-DRB1*04 subtypes strongly bound the aggregation-prone tau PHF6 sequence, however only when acetylated at a lysine (K311), a common posttranslational modification central to tau aggregation. An HLA-DRB1*04-mediated adaptive immune response decreases PD and AD risks, potentially by acting against tau, offering the possibility of therapeutic avenues

    Morphogeometric Evaluation of the Left Ventricle and Left Atrioventricular Ring in Dogs: A Computerized Anatomical Study

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    In veterinary, there is scarce availability of morphogeometric studies in normal and remodeled hearts; furthermore, ventricular geometry acts as an indicator of cardiac function. It is a highly necessary field of knowledge for the development of therapeutic protocols, especially surgical ones. The objectives of this study were: to obtain measurements of the left atrioventricular valve ring and left ventricle, to analyze the proportionality between the segments of the left cardiac chamber of normal hearts and to describe reference values for morphogeometric analysis of the left ventricle. For this, 50 hearts from small (Group 1‚ÄĒG1) and medium to large (Group 2‚ÄĒG2) dogs were laminated in the apical, basal and equatorial segments, and submitted to computer analysis to identify the perimeter of each segment and the left atrioventricular ring, wall thickness and distance from the atrioventricular sulcus to the apex. The largest internal perimeter was that of the equatorial. The basal segment had the highest mean for ventral parietal wall thickness, suggesting greater contractile reserve at that location. Considering the proportionality relationships, there was no statistical difference between the intersegmental perimeter indices for the two groups. This suggests that despite the animals‚Äô weight variations, the proportions between the left ventricular segments are maintained. Therefore, it is concluded that the data can be used as a standard of comparison for cardiac geometric assessments, as well as a basis for the development of therapeutic measures in the context of adverse cardiac remodeling

    New insights into the genetic etiology of Alzheimer’s disease and related dementias

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    Characterization of the genetic landscape of Alzheimer‚Äôs disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/‚Äėproxy‚Äô AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE őĶ4 allele

    New insights into the genetic etiology of Alzheimer’s disease and related dementias