533 research outputs found

    Hydrologic simulation of a neotropical alpine catchment influenced by conductive topsoils in the Ecuadorian Andes

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    Highly conductive topsoils in neotropical high-elevation grassland-dominated ecosystems, or so-called paramos in the Andean region, influence the local rainfall-runoff processes predominated by saturation-excess overland flow as the primary source of freshwater. The Soil and Water Assessment Tool (SWAT) model has shown limitations when applied to mountainous catchments with highly conductive soils that generate surface runoff as saturation-excess overland flow. In this study, we enhanced SWAT to simulate runoff as saturation-excess overland flow and examined the hydrological responses of an intensively monitored paramo catchment in Ecuador. The model setup considered a detailed representation of the hydro-physical properties of the soils at different depths, including high infiltration and lateral flow rates in the hillslopes and restricted groundwater interactions, a characteristic of the páramo catchments. SWAT reasonably reproduced the daily discharge during dry and wet periods and the cumulative occurrence of high and low flows. The performance metrics NSE, RSR, and PBIAS values during calibration/validation period were 0.86/0.84, 0.31/0.4, and −11.2/-7.58, respectively. The runoff ratio and partitioning of the total runoff into the lateral flow and surface runoff were physically meaningful. More significantly, SWAT was able to simulate saturation-excess overland flow, which is dominant compared to infiltration excess, and it is a distinctive characteristic of páramo catchments. Nevertheless, the model showed limitations in simulating low flows

    Long-range and short-range dihadron angular correlations in central PbPb collisions at √sNN=2.76 TeV

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    This is the pre-print version of the Published Article, which can be accessed from the link below.First measurements of dihadron correlations for charged particles are presented for central PbPb collisions at a nucleon-nucleon center-of-mass energy of 2.76TeV over a broad range in relative pseudorapidity ( ) and the full range of relative azimuthal angle ( ). The data were collected with the CMS detector, at the LHC. A broadening of the away-side ( ) azimuthal correlation is observed at all , as compared to the measurements in pp collisions. Furthermore, long-range dihadron correlations in are observed for particles with similar values. This phenomenon, also known as the \ridge", persists up to at least j j = 4. For particles with transverse momenta (pT) of 2-4 GeV/c, the ridge is found to be most prominent when these particles are correlated with particles of pT = 2-6 GeV/c, and to be much reduced when paired with particles of pT = 10-12 GeV/c

    The Suitability of the SWAT Model to Perform Hydrolocial Assessments in High-Elevation Neotropical Catchments

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    Neotropical alpine wetlands, or so-called páramos, are one of the primary sources of freshwater in the Northern Andes. Páramos present a huge water storage and regulation capacity, which occur as a function of their geographic location, topography, soil composition, and endemic vegetation coverage. However, during the last decades, the rapid transformation of Andean landscapes into productivity lands have negatively impacted the páramos. Studies show that changes in land coverage can irreversibly alter the physical properties of the soils and decrease the water yield and regulation capacity. In addition, the projected increase in the mean air temperature due to climate change can naturally shift the vegetation patterns in páramo areas and worsen the hydrological impacts. These anthropogenic and natural disturbances constitute a constant threat to the livelihood of 135 million people who depend on the services provided by páramos. Hydrological models have been widely applied to evaluate the impacts of natural and human disturbances on Andean catchments. Overall, models have shown satisfactory performance for runoff simulation, but their application in páramo catchments are limited because of the reduced availability of hydrometeorological data. Thus, hydrological assessments in páramo catchments are prone to large uncertainties and modeling outcomes may misrepresent the páramos behavior. Hence, a proper representation of the páramos’ hydrology through hydrological modeling remains a challenge. This study used high-resolution hydrometeorological data to evaluate the suitability of the Soil and Water Assessment Tool (SWAT) for simulating the rainfall-runoff response of an Andean páramo catchment. SWAT was forced to simulate runoff by saturation excess, and the model setup included a detailed description of soil properties at different depths. SWAT performance was evaluated through graphical and statistical metrics, and through the distribution of the local water balance. The validated SWAT model was applied to evaluate the relations among land coverage, soil hydro-physical properties, runoff generation, and catchment storage. Finally, this study evaluated the hydrological impacts due to pine afforestation on the water yield and water storage capacity of tropical alpine catchments

    How do women living with HIV experience menopause? Menopausal symptoms, anxiety and depression according to reproductive age in a multicenter cohort

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    CatedresBackground: To estimate the prevalence and severity of menopausal symptoms and anxiety/depression and to assess the differences according to menopausal status among women living with HIV aged 45-60 years from the cohort of Spanish HIV/AIDS Research Network (CoRIS). Methods: Women were interviewed by phone between September 2017 and December 2018 to determine whether they had experienced menopausal symptoms and anxiety/depression. The Menopause Rating Scale was used to evaluate the prevalence and severity of symptoms related to menopause in three subscales: somatic, psychologic and urogenital; and the 4-item Patient Health Questionnaire was used for anxiety/depression. Logistic regression models were used to estimate odds ratios (ORs) of association between menopausal status, and other potential risk factors, the presence and severity of somatic, psychological and urogenital symptoms and of anxiety/depression. Results: Of 251 women included, 137 (54.6%) were post-, 70 (27.9%) peri- and 44 (17.5%) pre-menopausal, respectively. Median age of onset menopause was 48 years (IQR 45-50). The proportions of pre-, peri- and post-menopausal women who had experienced any menopausal symptoms were 45.5%, 60.0% and 66.4%, respectively. Both peri- and post-menopause were associated with a higher likelihood of having somatic symptoms (aOR 3.01; 95% CI 1.38-6.55 and 2.63; 1.44-4.81, respectively), while post-menopause increased the likelihood of having psychological (2.16; 1.13-4.14) and urogenital symptoms (2.54; 1.42-4.85). By other hand, post-menopausal women had a statistically significant five-fold increase in the likelihood of presenting severe urogenital symptoms than pre-menopausal women (4.90; 1.74-13.84). No significant differences by menopausal status were found for anxiety/depression. Joint/muscle problems, exhaustion and sleeping disorders were the most commonly reported symptoms among all women. Differences in the prevalences of vaginal dryness (p = 0.002), joint/muscle complaints (p = 0.032), and sweating/flush (p = 0.032) were found among the three groups. Conclusions: Women living with HIV experienced a wide variety of menopausal symptoms, some of them initiated before women had any menstrual irregularity. We found a higher likelihood of somatic symptoms in peri- and post-menopausal women, while a higher likelihood of psychological and urogenital symptoms was found in post-menopausal women. Most somatic symptoms were of low or moderate severity, probably due to the good clinical and immunological situation of these women

    COVID-19 in hospitalized HIV-positive and HIV-negative patients : A matched study

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    CatedresObjectives: We compared the characteristics and clinical outcomes of hospitalized individuals with COVID-19 with [people with HIV (PWH)] and without (non-PWH) HIV co-infection in Spain during the first wave of the pandemic. Methods: This was a retrospective matched cohort study. People with HIV were identified by reviewing clinical records and laboratory registries of 10 922 patients in active-follow-up within the Spanish HIV Research Network (CoRIS) up to 30 June 2020. Each hospitalized PWH was matched with five non-PWH of the same age and sex randomly selected from COVID-19@Spain, a multicentre cohort of 4035 patients hospitalized with confirmed COVID-19. The main outcome was all-cause in-hospital mortality. Results: Forty-five PWH with PCR-confirmed COVID-19 were identified in CoRIS, 21 of whom were hospitalized. A total of 105 age/sex-matched controls were selected from the COVID-19@Spain cohort. The median age in both groups was 53 (Q1-Q3, 46-56) years, and 90.5% were men. In PWH, 19.1% were injecting drug users, 95.2% were on antiretroviral therapy, 94.4% had HIV-RNA < 50 copies/mL, and the median (Q1-Q3) CD4 count was 595 (349-798) cells/μL. No statistically significant differences were found between PWH and non-PWH in number of comorbidities, presenting signs and symptoms, laboratory parameters, radiology findings and severity scores on admission. Corticosteroids were administered to 33.3% and 27.4% of PWH and non-PWH, respectively (P = 0.580). Deaths during admission were documented in two (9.5%) PWH and 12 (11.4%) non-PWH (P = 0.800). Conclusions: Our findings suggest that well-controlled HIV infection does not modify the clinical presentation or worsen clinical outcomes of COVID-19 hospitalization

    Search for high-mass exclusive γγ\gamma\gamma\to WW and γγ\gamma\gamma\to ZZ production in proton-proton collisions at s\sqrt{s} = 13 TeV

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    A search is performed for exclusive high-mass γγ\gamma\gamma\to WW and γγ\gamma\gamma\to ZZ production in proton-proton collisions using intact forward protons reconstructed in near-beam detectors, with both weak bosons decaying into boosted and merged jets. The analysis is based on a sample of proton-proton collisions collected by the CMS and TOTEM experiments at s \sqrt{s} = 13 TeV, corresponding to an integrated luminosity of 100 fb1^{−1}. No excess above the standard model background prediction is observed, and upper limits are set on the pp → pWWp and pp → pZZp cross sections in a fiducial region defined by the diboson invariant mass m(VV) > 1 TeV (with V = W, Z) and proton fractional momentum loss 0.04 < ξξ < 0.20. The results are interpreted as new limits on dimension-6 and dimension-8 anomalous quartic gauge couplings.[graphic not available: see fulltext

    Measurement of inclusive and differential cross sections for single top quark production in association with a W boson in proton-proton collisions at s \sqrt{s} = 13 TeV

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    International audienceMeasurements of the inclusive and normalised differential cross sections are presented for the production of single top quarks in association with a W boson in proton-proton collisions at a centre-of-mass energy of 13 TeV. The data used were recorded with the CMS detector at the LHC during 2016–2018, and correspond to an integrated luminosity of 138 fb1^{−1}. Events containing one electron and one muon in the final state are analysed. For the inclusive measurement, a multivariate discriminant, exploiting the kinematic properties of the events is used to separate the signal from the dominant tt \textrm{t}\overline{\textrm{t}} background. A cross section of 79.2±0.9(stat)8.0+7.7(syst)±1.2(lumi) 79.2\pm 0.9{\left(\textrm{stat}\right)}_{-8.0}^{+7.7}\left(\textrm{syst}\right)\pm 1.2\left(\textrm{lumi}\right) pb is obtained, consistent with the predictions of the standard model. For the differential measurements, a fiducial region is defined according to the detector acceptance, and the requirement of exactly one jet coming from the fragmentation of a bottom quark. The resulting distributions are unfolded to particle level and agree with the predictions at next-to-leading order in perturbative quantum chromodynamics.[graphic not available: see fulltext

    Search for Higgs Boson and Observation of Z Boson through their Decay into a Charm Quark-Antiquark Pair in Boosted Topologies in Proton-Proton Collisions at s\sqrt{s} =13 TeV

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    A search for the standard model (SM) Higgs boson (H) produced with transverse momentum greater than 450 GeV and decaying to a charm quark-antiquark (ccˉ\mathrm{c\bar{c}}) pair is presented. The search is performed using proton-proton collision data collected at s\sqrt{s} = 13 TeV by the CMS experiment at the LHC, corresponding to an integrated luminosity of 138 fb1^{-1}. Boosted H \toccˉ\mathrm{c\bar{c}} decay products are reconstructed as a single large-radius jet and identified using a deep neural network charm tagging technique. The method is validated by measuring the Z \toccˉ\mathrm{c\bar{c}} decay process, which is observed in association with jets at high pTp_\mathrm{T} for the first time with a signal strength of 1.00 0.14+0.17_{-0.14}^{+0.17} (syst) ±\pm 0.08 (theo) ±\pm 0.06 (stat), defined as the ratio of the observed process rate to the standard model expectation. The observed (expected) upper limit on σ\sigma(H) B\mathcal{B}(H \toccˉ\mathrm{c\bar{c}}) is set at 47 (39) times the SM prediction at 95% confidence level
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