6,767 research outputs found

    Cardiometabolic Plasticity in Response to a Short-Term Diet and Exercise Intervention in Young Hispanic and NonHispanic White Adults

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    BACKGROUND: Young adult Mexican Americans (MA) exhibit lower insulin sensitivity (Si) than nonHispanic whites (NHW), even when controlling for fitness and adiposity. It is unclear if MA are as responsive to the same lifestyle intervention as NHW. OBJECTIVE: We developed a model to examine cardiometabolic plasticity (i.e., changes in Si and plasma lipids) in MA compared to NHW adults in response to a diet-exercise intervention. DESIGN: Sedentary subjects (20 NHW: 11F, 9M, 23.0 y, 25.5 kg/m(2); 17 MA: 13F, 4M, 22.7 y, 25.4 kg/m(2)) consumed their habitual diets and remained sedentary for 7 days, after which fasting blood samples were obtained, and a 3-h intravenous glucose tolerance test (IVGTT) was performed with the insulin area under the curve (IAUC) used to estimate Si. Subjects then completed a 7-day diet/exercise intervention (diet: low saturated fat, low added sugar, high fiber; exercise: cycling, six total sessions lasting 40-45 min/session at 65% VO(2) max). Pre-intervention tests were repeated. RESULTS: Pre intervention IAUC was 28% higher (p<0.05) in MA (IAUC pre  =  2298 µU*180 min/mL) than in NHW (IAUC = 1795 µU*180 min/mL). Following the intervention, there was a significant reduction in IAUC in MA (29%) and NHW (32%), however, the IAUC remained higher (p<0.05) for MA (post  = 1635 µU*180 min/mL) than for NHW (post = 1211 µU*180 min/mL). Pre test plasma lipids were not different in MA compared to NHW. Plasma cholesterol and TG concentrations significantly improved in both groups, but concentrations of low density lipoprotein-cholesterol and small dense LDL particles significantly improved only in the NHW. CONCLUSION: With a short-term diet-exercise intervention, the magnitude of improvements in Si and serum cholesterol and TG in Hispanics are similar to those in NHW. However, because at the outset MA were less insulin sensitive compared to NHW, within the short timeframe studied the ethnic gap in insulin sensitivity remained

    Invertebrate traits, diversity and the vulnerability of groundwater ecosystems

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    Funding Information: This manuscript evolved from a workshop titled Trait‐based analyses in groundwater ecology and bioassessment held as part of the 24th International Conference on Subterranean Biology, 20–24th August 2018, University of Aveiro, Portugal. The workshop was supported by the conference organisers and the Macquarie University Species Spectrum Research Centre. Financial support was also provided to M.A.D. by the Portuguese government (Fundação para a Ciência e Tecnologia; FCT) through the research unit UIDB/04085/2020 (CENSE). A.S.P.S.R. was supported by the VILLUM FONDEN (research grant 15471) and by Portuguese National Funds through Fundação para a Ciência e a Tecnologia within the cE3c Unit funding UIDB/00329/2020. S.I.S. acknowledges funding through EU Operational Programme Research, Development and Education No. CZ.02.2.69/0.0/0.0/16_027/0008357, and by the Ministry of Education, Youth and Sports of the Czech Republic [grant number CZ.02.1.01/0.0/0.0/16 025/0007417]. K.L.K. was supported in part by Australian Research Council grant LP190100927. The comments of the Editor, Associate Editor and an anonymous reviewer greatly improved the MS. Open access publishing facilitated by Macquarie University, as part of the Wiley ‐ Macquarie University agreement via the Council of Australian University Librarians. Publisher Copyright: © 2022 The Authors. Functional Ecology published by John Wiley & Sons Ltd on behalf of British Ecological Society.Groundwater comprises the largest freshwater ecosystem on the planet. It has a distinct regime of extreme, yet stable environmental conditions that have favoured the development of similar morphological and functional traits in the resident invertebrate fauna (stygofauna). The analysis of community traits is increasingly used as an alternative to taxonomy-based assessments of biodiversity, especially for monitoring ecosystem status and linking the functions of organisms to ecological processes, yet it has been rarely applied to stygofauna and groundwater ecosystems. In this paper, we review the variation in functional traits among the invertebrate fauna of this important ecosystem. We focus on the stygofauna and processes of alluvium and fractured rock aquifers that are typified by small voids and fissures that constrain the habitats and environmental conditions. As a first step, we compare trait variability between groundwater and surface water invertebrate communities and then examine the significance of the ranges of these traits to the vulnerability of the ecosystem to change. Fifteen potentially useful functional traits are recognised. Eight of these have narrower ranges (i.e. exhibit fewer states, or attributes, of a particular trait) in groundwater than they do in surface water. Two traits have wider ranges. Our synthesis suggests that the relative stability of groundwater environments has led to low trait variability. The low biomass and low reproductive rate of stygofauna suggest that recovery potential following disturbance is likely to be low. For the purposes of both improved understanding and effective management, further work is needed to document additional functional traits and their states in groundwater fauna, enabling a better understanding of the relationship between response and effect traits in these ecosystems. Read the free Plain Language Summary for this article on the Journal blog.publishersversionpublishe

    Five insights from the Global Burden of Disease Study 2019

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    The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 provides a rules-based synthesis of the available evidence on levels and trends in health outcomes, a diverse set of risk factors, and health system responses. GBD 2019 covered 204 countries and territories, as well as first administrative level disaggregations for 22 countries, from 1990 to 2019. Because GBD is highly standardised and comprehensive, spanning both fatal and non-fatal outcomes, and uses a mutually exclusive and collectively exhaustive list of hierarchical disease and injury causes, the study provides a powerful basis for detailed and broad insights on global health trends and emerging challenges. GBD 2019 incorporates data from 281 586 sources and provides more than 3·5 billion estimates of health outcome and health system measures of interest for global, national, and subnational policy dialogue. All GBD estimates are publicly available and adhere to the Guidelines on Accurate and Transparent Health Estimate Reporting. From this vast amount of information, five key insights that are important for health, social, and economic development strategies have been distilled. These insights are subject to the many limitations outlined in each of the component GBD capstone papers

    Largest M Dwarf Flares from ASAS-SN

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    The All-sky Automated Survey for Supernovae (ASAS-SN) is the only project in existence to scan the entire sky in optical light approximately every day, reaching a depth of g ~ 18 mag. Over the course of its first 4 yr of transient alerts (2013–2016), ASAS-SN observed 53 events classified as likely M dwarf flares. We present follow-up photometry and spectroscopy of all 53 candidates, confirming flare events on 47 M dwarfs, one K dwarf, and one L dwarf. The remaining four objects include a previously identified T Tauri star, a young star with outbursts, and two objects too faint to confirm. A detailed examination of the 49 flare star light curves revealed an additional six flares on five stars, resulting in a total of 55 flares on 49 objects ranging in V-band contrast from ΔV = −1 to −10.2 mag. Using an empirical flare model to estimate the unobserved portions of the flare light curve, we obtain lower limits on the V-band energy emitted during each flare, spanning log(E_V/erg) = 32–35, which are among the most energetic flares detected on M dwarfs. The ASAS-SN M dwarf flare stars show a higher fraction of Hα emission, as well as stronger Hα emission, compared to M dwarfs selected without reference to activity, consistent with belonging to a population of more magnetically active stars. We also examined the distribution of tangential velocities, finding that the ASAS-SN flaring M dwarfs are likely to be members of the thin disk and are neither particularly young nor old

    'Immunising' physicians against availability bias in diagnostic reasoning: A randomised controlled experiment

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    Background: Diagnostic errors have often been attributed to biases in physicians' reasoning. Interventions to 'immunise' physicians against bias have focused on improving reasoning processes and have largely failed. Objective: To investigate the effect of increasing physicians' relevant knowledge on their susceptibility to availability bias. Design, settings and participants: Three-phase multicentre randomised experiment with second-year internal medicine residents from eight teaching hospitals in Brazil. Interventions: Immunisation: Physicians diagnosed one of two sets of vignettes (either diseases associated with chronic diarrhoea or with jaundice) and compared/contrasted alternative diagnoses with feedback. Biasing phase (1 week later): Physicians were biased towards either inflammatory bowel disease or viral hepatitis. Diagnostic performance test: All physicians diagnosed three vignettes resembling inflammatory bowel disease, three resembling hepatitis (however, all with different diagnoses). Physicians who increased their knowledge of either chronic diarrhoea or jaundice 1 week earlier were expected to resist the bias attempt. Main outcome measurements: Diagnostic accuracy, measured by test score (range 0-1), computed for subjected-to-bias and not-subjected-to-bias vignettes diagnosed by immunised and not-immunised physicians. Results: Ninety-one residents participated in the experiment. Diagnostic accuracy differed on subjected-to-bias vignettes, with immunised physicians performing better than non-immunised physicians (0.40 vs 0.24; difference in accuracy 0.16 (95% CI 0.05 to 0.27); p=0.004), but not on not-subjected-to-bias vignettes (0.36 vs 0.41; difference -0.05 (95% CI -0.17 to 0.08); p=0.45). Bias only hampered non-immunised physicians, who performed worse on subjected-to-bias than not-subjected-to-bias vignettes (difference -0.17 (95% CI -0.28 to -0.05); p=0.005); immunised physicians' accuracy did not differ (p=0.56). Conclusions: An intervention directed at increasing knowledge of clinical findings that discriminate between similar-looking diseases decreased physicians' susceptibility to availability bias, reducing diagnostic errors, in a simulated setting. Future research needs to examine the degree to which the intervention benefits other disease clusters and performance in clinical practice. Trial registration number: 68745917.1.1001.0068

    Probing the Inner Jet of the Quasar PKS 1510-089 with Multi-waveband Monitoring during Strong Gamma-ray Activity

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    We present results from monitoring the multi-waveband flux, linear polarization, and parsec-scale structure of the quasar PKS 1510-089, concentrating on eight major gamma-ray flares that occurred during the interval 2009.0-2009.5. The gamma-ray peaks were essentially simultaneous with maxima at optical wavelengths, although the flux ratio of the two wavebands varied by an order of magnitude. The optical polarization vector rotated by 720 degrees during a 5-day period encompassing six of these flares. This culminated in a very bright, roughly 1 day, optical and gamma-ray flare as a bright knot of emission passed through the highest-intensity, stationary feature (the "core") seen in 43 GHz Very Long Baseline Array images. The knot continued to propagate down the jet at an apparent speed of 22c and emit strongly at gamma-ray energies as a months-long X-ray/radio outburst intensified. We interpret these events as the result of the knot following a spiral path through a mainly toroidal magnetic field pattern in the acceleration and collimation zone of the jet, after which it passes through a standing shock in the 43 GHz core and then continues downstream. In this picture, the rapid gamma-ray flares result from scattering of infrared seed photons from a relatively slow sheath of the jet as well as from optical synchrotron radiation in the faster spine. The 2006-2009.7 radio and X-ray flux variations are correlated at very high significance; we conclude that the X-rays are mainly from inverse Compton scattering of infrared seed photons by 20-40 MeV electrons.Comment: 10 pages of text + 5 figures, to be published in Astrophysical Journal Letters in 201
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