2,361 research outputs found

    New distribution records, habitat description and comments on the natural history of the poorly known frog Atelognathus solitarius (Anura, Batrachylidae) from northwestern Patagonia, Río Negro Province, Argentina

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    Atelognathus solitarius is probably the least-known species of its genus. The species was described in 1970 based on a single specimen from the Las Bayas Creek, Río Negro Province, Argentina; later publications that reported new specimens did not provide new localities. Here, we present an update of its distribution, describe the habitats it occupies, detail features of its natural history, and discuss conservation aspects. For this purpose, all available records were compiled from herpetological collections, literature, and new data obtained during field trips to the type locality and surroundings. We confirmed the presence of the species near its type locality and extended the known distribution about 30 km WSW and 30 km NW. Furthermore, we discovered that in addition to using small streams, A. solitarius uses lagoons in volcanic tablelands. Future studies on the biological and ecological aspects of the species are essential to update the current conservation category of ‘Insufficiently Known’ for Argentinean categorization or ‘Data Deficient’ for IUCN.Fil: Barrasso, Diego Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Diversidad y Evolución Austral; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Área Zoología; ArgentinaFil: Basso, Nestor Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Diversidad y Evolución Austral; ArgentinaFil: Sage, Richard David. Sociedad Naturalista Andino Patagónica (SNAP); ArgentinaFil: Úbeda, Carmen. Universidad Nacional del Comahue; Argentin

    Physiological niche and geographical range in European diving beetles (Coleoptera: Dytiscidae).

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    Geographical ranges vary greatly in size and position, even within recent clades, but the factors driving this remain poorly understood. In aquatic beetles, thermal niche has been shown to be related to both the relative range size and position of congeners but whether other physiological parameters play a role is unknown. Metabolic plasticity may be critical for species occupying more variable thermal environments and maintaining this plasticity may trade-off against other physiological processes such as immunocompetence. Here we combine data on thermal physiology with measures of metabolic plasticity and immunocompetence to explore these relationships in Deronectes (Dytiscidae). While variation in latitudinal range extent and position was explained in part by thermal physiology, aspects of metabolic plasticity and immunocompetence also appeared important. Northerly distributed, wide-ranging species apparently used different energy reserves under thermal stress from southern endemic congeners and differed in their antibacterial defences. This is the first indication that these processes may be related to geographical range, and suggests parameters that may be worthy of exploration in other taxa

    Late Quaternary Activity of the La Rinconada Fault Zone, San Juan, Argentina

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    Most of the permanent deformation in the Pampean Flat slab segment of the central Andes is taken up at the Andean Orogenic Front in Argentina, a narrow zone between the Eastern Precordillera and Sierras Pampeanas that comprises one of the world's most seismically active thrust zones. Active faults and folds in the region have been extensively mapped but still largely lack information on style and rates of deformation, which is essential for understanding the distribution of regional strain and estimating the seismic potential of individual faults. Structural, geomorphic, and 36Cl cosmogenic radionuclide surface exposure age methods are used to focus on key sites along the 30-km-long La Rinconada Fault Zone in this region of west-central Argentina, which is ~15 km away from the highly populated (~500,000) city of San Juan, to define a late Quaternary average shortening rate of 0.41 ± 0.01 mm/year. This slip rate is the same order of magnitude, but slightly lower than nearby similar east dipping Eastern Precordillera faults including the La Laja and Las Tapias Faults. Relatively low slip rates are interpreted as being a consequence of distributed deformation between the latitude of the La Rinconada Fault Zone (31 and 32°S), as compared to between latitudes 32 to 33°S where deformation appears to be focused on fewer structures, including the Las Peñas and La Cal Thrust Faults. The La Rinconada Fault Zone is capable of generating earthquakes of Mw 6.6–7.2, but further investigations are required to determine timing and recurrence intervals of discrete events.Fil: Rimando, Jeremy. University of Toronto; CanadáFil: Schoenbohm, Lindsay. University of Toronto; CanadáFil: Costa, Carlos Horacio. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Departamento de Geología; ArgentinaFil: Owen, Lewis. University of Cincinnati; Estados UnidosFil: Cesta, Jason M.. University of Cincinnati; Estados UnidosFil: Richard, Andrés David. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Departamento de Geología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis; ArgentinaFil: Gardini, Carlos Enrique. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Departamento de Geología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis; Argentin

    Trypanosoma brucei aquaglyceroporin 2 is a high-affinity transporter for pentamidine and melaminophenyl arsenic drugs and the main genetic determinant of resistance to these drugs.

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    OBJECTIVES: Trypanosoma brucei drug transporters include the TbAT1/P2 aminopurine transporter and the high-affinity pentamidine transporter (HAPT1), but the genetic identity of HAPT1 is unknown. We recently reported that loss of T. brucei aquaglyceroporin 2 (TbAQP2) caused melarsoprol/pentamidine cross-resistance (MPXR) in these parasites and the current study aims to delineate the mechanism by which this occurs. METHODS: The TbAQP2 loci of isogenic pairs of drug-susceptible and MPXR strains of T. brucei subspecies were sequenced. Drug susceptibility profiles of trypanosome strains were correlated with expression of mutated TbAQP2 alleles. Pentamidine transport was studied in T. brucei subspecies expressing TbAQP2 variants. RESULTS: All MPXR strains examined contained TbAQP2 deletions or rearrangements, regardless of whether the strains were originally adapted in vitro or in vivo to arsenicals or to pentamidine. The MPXR strains and AQP2 knockout strains had lost HAPT1 activity. Reintroduction of TbAQP2 in MPXR trypanosomes restored susceptibility to the drugs and reinstated HAPT1 activity, but did not change the activity of TbAT1/P2. Expression of TbAQP2 sensitized Leishmania mexicana promastigotes 40-fold to pentamidine and >1000-fold to melaminophenyl arsenicals and induced a high-affinity pentamidine transport activity indistinguishable from HAPT1 by Km and inhibitor profile. Grafting the TbAQP2 selectivity filter amino acid residues onto a chimeric allele of AQP2 and AQP3 partly restored susceptibility to pentamidine and an arsenical. CONCLUSIONS: TbAQP2 mediates high-affinity uptake of pentamidine and melaminophenyl arsenicals in trypanosomes and TbAQP2 encodes the previously reported HAPT1 activity. This finding establishes TbAQP2 as an important drug transporter

    Bat trait, genetic and pathogen data from large-scale investigations of African fruit bats, Eidolon helvum.

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    Bats, including African straw-coloured fruit bats (Eidolon helvum), have been highlighted as reservoirs of many recently emerged zoonotic viruses. This common, widespread and ecologically important species was the focus of longitudinal and continent-wide studies of the epidemiological and ecology of Lagos bat virus, henipaviruses and Achimota viruses. Here we present a spatial, morphological, demographic, genetic and serological dataset encompassing 2827 bats from nine countries over an 8-year period. Genetic data comprises cytochrome b mitochondrial sequences (n=608) and microsatellite genotypes from 18 loci (n=544). Tooth-cementum analyses (n=316) allowed derivation of rare age-specific serologic data for a lyssavirus, a henipavirus and two rubulaviruses. This dataset contributes a substantial volume of data on the ecology of E. helvum and its viruses and will be valuable for a wide range of studies, including viral transmission dynamic modelling in age-structured populations, investigation of seasonal reproductive asynchrony in wide-ranging species, ecological niche modelling, inference of island colonisation history, exploration of relationships between island and body size, and various spatial analyses of demographic, morphometric or serological data.This is the final version of the article. It first appeared from Nature Publishing Group via http://dx.doi.org/10.1038/sdata.2016.4

    A machine-learning data set prepared from the NASA solar dynamics observatory mission

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    In this paper, we present a curated data set from the NASA Solar Dynamics Observatory (SDO) mission in a format suitable for machine-learning research. Beginning from level 1 scientific products we have processed various instrumental corrections, down-sampled to manageable spatial and temporal resolutions, and synchronized observations spatially and temporally. We illustrate the use of this data set with two example applications: forecasting future extreme ultraviolet (EUV) Variability Experiment (EVE) irradiance from present EVE irradiance and translating Helioseismic and Magnetic Imager observations into Atmospheric Imaging Assembly observations. For each application, we provide metrics and baselines for future model comparison. We anticipate this curated data set will facilitate machine-learning research in heliophysics and the physical sciences generally, increasing the scientific return of the SDO mission. This work is a direct result of the 2018 NASA Frontier Development Laboratory Program. Please see the Appendix for access to the data set, totaling 6.5TBs

    Children’s first experience of taking anabolic-androgenic steroids can occur before their 10th birthday: a systematic review identifying 9 factors that predict doping among young people

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    Taking performance-enhancing drugs (PEDs) can cause serious and irreversible health consequences, which can ultimately lead to premature death. Some young people may take PEDs without fully understanding the ramifications of their actions or based on the advice from others. The purpose of this systematic review was to identify the main factors that predicted doping among young people. The literature was systematically reviewed using search engines, manually searching specialist journals, and pearl growing. Fifty-two studies, which included 187,288 young people aged between 10 and 21 years of age, 883 parents of adolescent athletes, and 11 adult coaches, who were interviewed regarding young athletes, were included in this review. Nine factors predicted doping among young people: gender; age; sports participation; sport type; psychological variables; entourage; ethnicity; nutritional supplements’ and health harming behaviors. In regards to psychological variables, 22 different constructs were associated with doping among young people. Some psychological constructs were negatively associated with doping (e.g., self-esteem, resisting social pressure, and perfectionist strivings), whereas other were positively associated with doping (e.g., suicide risk, anticipated regret, and aggression). Policy makers and National Anti-Doping Organisations could use these findings to help identify athletes who are more at risk of doping and then expose these individuals to anti-doping education. Based on the current findings, it also appears that education programs should commence at the onset of adolescence or even late childhood, due to the young age in which some individuals start doping

    Publicación científica entre los directivos de la Asociación Científica de Estudiantes de Medicina de Colombia: características y factores asociados

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    Introducción. La publicación científica se debe incentivar desde el pregrado, sobre todo en carreras de ciencias de la salud.Objetivo. Determinar las características y los factores asociados a la publicación científica entre los miembros de la Asociación Científica de Estudiantes de Medicina de Colombia (ASCEMCOL).Materiales y métodos. Se realizó un estudio transversal analítico que se basó en una encuesta presencial aplicada a los miembros de la ASCEMCOL. Se definió como publicación la realizada en una revista científica indexada; la información recolectada se cruzó con variables para obtener estadísticos de asociación.Resultados. Al realizar el análisis multivariado, se asoció a mayor participación en investigaciones científicas el encontrarse en un semestre académico superior (RPa: 1.25; IC95%: 1.01-1.56; p=0.043) y tener más cantidad de investigaciones extracurriculares (RPa: 1.26; IC95%: 1.15-1.38; p0.001); así mismo, la menor frecuencia de publicación se asoció a la percepción de pobre apoyo por parte de la universidad (RPa: 0.28; IC95%: 0.22-0.34; p0.001), ajustado por la cantidad de trabajos presentados a congresos y la universidad de procedencia.Conclusión. La frecuencia de publicación fue baja en esta población. Se encontraron factores de gran importancia, como estar en un mayor semestre y tener mayor número de investigaciones realizadas y publicaciones.Introduction: The scientific publication should be encouraged from the undergraduates, especially in science health careers.Objective: To determine the features and factors associated with scientific publication among members of the Scientific Association of Medical Students of Colombia (ASCEMCOL).Materials and methods: An analytic cross-sectional study, which was based on a face survey applied to the members of the ASCEMCOL. A publication was defined as a publication made in an indexed scientific journal; and the information collected was crossed with variables to obtain a statistical association.Results: When performing multivariate analysis, it was associated with increased participation in scientific research the fact of being in a superior academic semester (RPA: 1.25; 95% CI: 1.01-1.56; p value: 0.043), more of extracurricular investigations (RPA: 1.26; 95% CI: 1.15-1.38; p value 0.001). Likewise, the lower frequency of publications associated with the perception of poor support from the university (RPA: 0.28; 95% CI: 0.22-0.34; p value 0.001), adjusted to the number of papers presented in congresses and the university of origin.Conclusion: The publication frequency was low in this population; we find important factors like being in a superior academic semester, such as having a greater number of investigations and publications

    Revealing the Chemical Structure of the Magellanic Clouds with APOGEE. III. Abundance Gradients of the Small Magellanic Cloud

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    We determine radial- and age-abundance gradients of the Small Magellanic Cloud (SMC) using spectra of 2,062 red giant branch (RGB) field stars observed by SDSS-IV / APOGEE-2S. With coverage out to \sim9 kpc in the SMC, these data taken with the high resolution (R22,500R \sim 22,500) APOGEE HH-band spectrograph afford the opportunity to measure extensive radial gradients for as many as 24 abundance ratios. The SMC is found to have an overall metallicity gradient of -0.0546 ±\pm 0.0043 dex/kpc. Ages are calculated for every star to explore the evolution of the different abundance gradients. As a function of age, many of the gradients show a feature 3.66--5.58 Gyr ago, which is especially prominent in the [X/H] gradients. Initially many gradients flatten until about \sim5.58 Gyr ago, but then steepen in more recent times. We previously detected similar evolutionary patterns in the Large Magellanic Cloud (LMC) which are attributed to a recent interaction between the LMC and SMC. It is inferred that the feature in the SMC gradients was caused by the same interaction. The age-[X/Fe] trends, which track average [X/Fe] over time, are flat, demonstrating a slow enrichment history for the SMC. When comparing the SMC gradients to the LMC and MW, normalized to disk scale length (RdR_\text{d}), the [X/Fe] and [X/Mg] gradients are similar, but there is a dichotomy between the dwarfs and the Milky Way (MW) for the [X/H] gradients. The median MW [X/H] gradient around -0.125 dex/RdR_\text{d} whilst the Clouds have gradients of about -0.075 dex/RdR_\text{d}.Comment: 27 pages, 22 figures, and 11 table

    Prospective Validation of Pooled Prognostic Factors in Women with Advanced Cervical Cancer Treated with Chemotherapy with/without Bevacizumab: NRG Oncology/GOG Study

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    PURPOSE: In the randomized phase III trial, Gynecologic Oncology Group (GOG) protocol 240, the incorporation of bevacizumab with chemotherapy significantly increased overall survival (OS) in women with advanced cervical cancer. A major objective of GOG-240 was to prospectively analyze previously identified pooled clinical prognostic factors known as the Moore criteria. EXPERIMENTAL DESIGN: Potential negative factors included black race, performance status 1, pelvic disease, prior cisplatin, and progression-free interval <365 days. Risk categories included low-risk (0-1 factor), mid-risk (2-3 factors), and high-risk (4-5 factors). Each test of association was conducted at the 5% level of significance. Logistic regression and survival analysis was used to determine whether factors were prognostic or could be used to guide therapy. RESULTS: For the entire population (n = 452), high-risk patients had significantly worse OS (P < 0.0001). The HRs of death for treating with topotecan in low-risk, mid-risk, and high-risk subsets are 1.18 [95% confidence interval (CI), 0.63-2.24], 1.11 (95% CI, 0.82-1.5), and 0.84 (95% CI, 0.50-1.42), respectively. The HRs of death for treating with bevacizumab in low-risk, mid-risk, and high-risk subsets are 0.96 (95% CI, 0.51-1.83; P = 0.9087), 0.673 (95% CI, 0.5-0.91; P = 0.0094), and 0.536 (95% CI, 0.32-0.905; P = 0.0196), respectively. CONCLUSIONS: This is the first prospectively validated scoring system in cervical cancer. The Moore criteria have real-world clinical applicability. Toxicity concerns may justify omission of bevacizumab in some low-risk patients where survival benefit is small. The benefit to receiving bevacizumab appears to be greatest in the moderate- and high-risk subgroups (5.8-month increase in median OS)
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