1,592 research outputs found

    Dual-energy X-ray absorptiometry study of body composition in patients with lipodystrophy

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    Inst Estadual Diabet & Endocrinol, Metab Unit, Rio de Janeiro, BrazilUniversidade Federal de São Paulo, Dept Endocrinol & Metab, São Paulo, BrazilDENSSO, Rio de Janeiro, BrazilUniversidade Federal de São Paulo, Dept Endocrinol & Metab, São Paulo, BrazilWeb of Scienc

    Fine-scale variability in coral bleaching and mortality during a marine heatwave

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    Coral bleaching and mortality can show significant spatial and taxonomic heterogeneity at local scales, highlighting the need to understand the fine-scale drivers and impacts of thermal stress. In this study, we used structure-from-motion photogrammetry to track coral bleaching, mortality, and changes in community composition during the 2019 marine heatwave in Kāneʻohe Bay, Hawaiʻi. We surveyed 30 shallow reef patches every 3 weeks for the duration of the bleaching event (August-December) and one year after, resulting in a total of 210 large-area, high-resolution photomosaics that enabled us to follow the fate of thousands of coral colonies through time. We also measured environmental variables such as temperature, sedimentation, depth, and wave velocity at each of these sites, and extracted estimates of habitat complexity (rugosity R and fractal dimension D) from digital elevation models to better understand their effects on patterns of bleaching and mortality. We found that up to 80% of corals experienced moderate to severe bleaching in this period, with peak bleaching occurring in October when heat stress (Degree Heating Weeks) reached its maximum. Mortality continued to accumulate as bleaching levels dropped, driving large declines in more heat-susceptible species (77% loss of Pocillopora cover) and moderate declines in heat-tolerant species (19% and 23% for Porites compressa and Montipora capitata, respectively). Declines in live coral were accompanied by a rapid increase in algal cover across the survey sites. Spatial differences in bleaching were significantly linked to habitat complexity and coral species composition, with reefs that were dominated by Pocillopora experiencing the most severe bleaching. Mortality was also influenced by species composition, fractal dimension, and site-level differences in thermal stress. Our results show that spatial heterogeneity in the impacts of bleaching are driven by a mix of environmental variation, habitat complexity, and differences in assemblage composition

    Genomics and epidemiology of the P.1 SARS-CoV-2 lineage in Manaus, Brazil

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    Cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in Manaus, Brazil, resurged in late 2020 despite previously high levels of infection. Genome sequencing of viruses sampled in Manaus between November 2020 and January 2021 revealed the emergence and circulation of a novel SARS-CoV-2 variant of concern. Lineage P.1 acquired 17 mutations, including a trio in the spike protein (K417T, E484K, and N501Y) associated with increased binding to the human ACE2 (angiotensin-converting enzyme 2) receptor. Molecular clock analysis shows that P.1 emergence occurred around mid-November 2020 and was preceded by a period of faster molecular evolution. Using a two-category dynamical model that integrates genomic and mortality data, we estimate that P.1 may be 1.7- to 2.4-fold more transmissible and that previous (non-P.1) infection provides 54 to 79% of the protection against infection with P.1 that it provides against non-P.1 lineages. Enhanced global genomic surveillance of variants of concern, which may exhibit increased transmissibility and/or immune evasion, is critical to accelerate pandemic responsiveness

    From colorectal cancer pattern to the characterization of individuals at risk: Picture for genetic research in Latin America

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    Colorectal cancer (CRC) is one of the most common cancers in Latin America and the Caribbean, with the highest rates reported for Uruguay, Brazil and Argentina. We provide a global snapshot of the CRC patterns, how screening is performed, and compared/contrasted to the genetic profile of Lynch syndrome (LS) in the region. From the literature, we find that only nine (20%) of the Latin America and the Caribbean countries have developed guidelines for early detection of CRC, and also with a low adherence. We describe a genetic profile of LS, including a total of 2,685 suspected families, where confirmed LS ranged from 8% in Uruguay and Argentina to 60% in Peru. Among confirmed LS, path_MLH1 variants were most commonly identified in Peru (82%), Mexico (80%), Chile (60%), and path_MSH2/EPCAM variants were most frequently identified in Colombia (80%) and Argentina (47%). Path_MSH6 and path_PMS2 variants were less common, but they showed important presence in Brazil (15%) and Chile (10%), respectively. Important differences exist at identifying LS families in Latin American countries, where the spectrum of path_MLH1 and path_MSH2 variants are those most frequently identified. Our findings have an impact on the evaluation of the patients and their relatives at risk for LS, derived from the gene affected. Although the awareness of hereditary cancer and genetic testing has improved in the last decade, it is remains deficient, with 39%–80% of the families not being identified for LS among those who actually met both the clinical criteria for LS and showed MMR deficiency.Fil: Vaccaro, Carlos Alberto. Hospital Italiano; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: López Kostner, Francisco. No especifíca;Fil: Adriana, Della Valle. Hospital Fuerzas Armadas; UruguayFil: Inez Palmero, Edenir. Hospital de cáncer de Barretos, FACISB; BrasilFil: Rossi, Benedito Mauro. Hospital Sirio Libanes; BrasilFil: Antelo, Marina. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología "Dr. Carlos B. Udaondo"; Argentina. Universidad Nacional de Lanús; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Solano, Angela Rosario. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Carraro, Dirce Maria. No especifíca;Fil: Forones, Nora Manoukian. Universidade Federal de Sao Paulo; BrasilFil: Bohorquez, Mabel. Universidad del Tolima; ColombiaFil: Lino Silva, Leonardo S.. Instituto Nacional de Cancerologia; MéxicoFil: Buleje, Jose. Universidad de San Martín de Porres; PerúFil: Spirandelli, Florencia. No especifíca;Fil: Abe Sandes, Kiyoko. Universidade Federal da Bahia; BrasilFil: Nascimento, Ivana. No especifíca;Fil: Sullcahuaman, Yasser. Universidad Peruana de Ciencias Aplicadas; Perú. Instituto de Investigación Genomica; PerúFil: Sarroca, Carlos. Hospital Fuerzas Armadas; UruguayFil: Gonzalez, Maria Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Medicina Traslacional e Ingeniería Biomédica - Hospital Italiano. Instituto de Medicina Traslacional e Ingeniería Biomédica.- Instituto Universitario Hospital Italiano de Buenos Aires. Instituto de Medicina Traslacional e Ingeniería Biomédica; ArgentinaFil: Herrando, Alberto Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Medicina Traslacional e Ingeniería Biomédica - Hospital Italiano. Instituto de Medicina Traslacional e Ingeniería Biomédica.- Instituto Universitario Hospital Italiano de Buenos Aires. Instituto de Medicina Traslacional e Ingeniería Biomédica; ArgentinaFil: Alvarez, Karin. No especifíca;Fil: Neffa, Florencia. Hospital Fuerzas Armadas; UruguayFil: Galvão, Henrique Camposreis. Barretos Cancer Hospital; BrasilFil: Esperon, Patricia. Hospital Fuerzas Armadas; UruguayFil: Golubicki, Mariano. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología "Dr. Carlos B. Udaondo"; ArgentinaFil: Cisterna, Daniel. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología "Dr. Carlos B. Udaondo"; ArgentinaFil: Cardoso, Florencia C.. Centro de Educación Medica E Invest.clinicas; ArgentinaFil: Tardin Torrezan, Giovana. No especifíca;Fil: Aguiar Junior, Samuel. No especifíca;Fil: Aparecida Marques Pimenta, Célia. Universidade Federal de Sao Paulo; BrasilFil: Nirvana da Cruz Formiga, María. No especifíca;Fil: Santos, Erika. Hospital Sirio Libanes; BrasilFil: Sá, Caroline U.. Hospital Sirio Libanes; BrasilFil: Oliveira, Edite P.. Hospital Sirio Libanes; BrasilFil: Fujita, Ricardo. Universidad de San Martín de Porres; PerúFil: Spirandelli, Enrique. No especifíca;Fil: Jimenez, Geiner. No especifíca;Fil: Santa Cruz Guindalini, Rodrigo. Universidade de Sao Paulo; BrasilFil: Gondim Meira Velame de Azevedo, Renata. No especifíca;Fil: Souza Mario Bueno, Larissa. Universidade Federal da Bahia; BrasilFil: dos Santos Nogueira, Sonia Tereza. No especifíca;Fil: Piñero, Tamara Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Medicina Traslacional e Ingeniería Biomédica - Hospital Italiano. Instituto de Medicina Traslacional e Ingeniería Biomédica.- Instituto Universitario Hospital Italiano de Buenos Aires. Instituto de Medicina Traslacional e Ingeniería Biomédica; Argentin

    Local hydrological conditions influence tree diversity and composition across the Amazon basin

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    Tree diversity and composition in Amazonia are known to be strongly determined by the water supplied by precipitation. Nevertheless, within the same climatic regime, water availability is modulated by local topography and soil characteristics (hereafter referred to as local hydrological conditions), varying from saturated and poorly drained to well-drained and potentially dry areas. While these conditions may be expected to influence species distribution, the impacts of local hydrological conditions on tree diversity and composition remain poorly understood at the whole Amazon basin scale. Using a dataset of 443 1-ha non-flooded forest plots distributed across the basin, we investigate how local hydrological conditions influence 1) tree alpha diversity, 2) the community-weighted wood density mean (CWM-wd) – a proxy for hydraulic resistance and 3) tree species composition. We find that the effect of local hydrological conditions on tree diversity depends on climate, being more evident in wetter forests, where diversity increases towards locations with well-drained soils. CWM-wd increased towards better drained soils in Southern and Western Amazonia. Tree species composition changed along local soil hydrological gradients in Central-Eastern, Western and Southern Amazonia, and those changes were correlated with changes in the mean wood density of plots. Our results suggest that local hydrological gradients filter species, influencing the diversity and composition of Amazonian forests. Overall, this study shows that the effect of local hydrological conditions is pervasive, extending over wide Amazonian regions, and reinforces the importance of accounting for local topography and hydrology to better understand the likely response and resilience of forests to increased frequency of extreme climate events and rising temperatures
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