3,089 research outputs found

    Wavefront reconstruction of discontinuous phase objects from optical deflectometry

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    One of the challenges in phase measuring deflectometry is to retrieve the wavefront from objects that present discontinuities or non-differentiable gradient fields. Here, we propose the integration of such gradients fields based on an Lp-norm minimization problem. The solution of this problem results in a nonlinear partial differential equation, which can be solved with a fast and well-known numerical methods and doesn't depend on external parameters. Numerical reconstructions on both synthetic and experimental data are presented that demonstrate the capability of the proposed method

    First measurements of a scintillator based fast-ion loss detector near the ASDEX Upgrade divertor

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    A new reciprocating scintillator based fast-ion loss detector has been installed a few centimeters above the outer divertor of the ASDEX Upgrade tokamak and between two of its lower Edge Localized Modes (ELM) mitigation coils. The detector head containing the scintillator screen, Faraday cup, calibration lamp, and collimator systems are installed on a motorized reciprocating system that can adjust its position via remote control in between plasma discharges. Orbit simulations are used to optimize the detector geometry and velocity-space coverage. The scintillator image is transferred to the light acquisition systems outside of the vacuum via a lens relay (embedded in a 3D-printed titanium holder) and an in-vacuum image guide. A charge coupled device camera, for high velocity-space resolution, and an 8 Ă— 8 channel avalanche photo diode camera, for high temporal resolution (up to 2 MHz), are used as light acquisition systems. Initial results showing velocity-space of neutral beam injection prompt losses and fast-ion losses induced by a (2, 1) neoclassical tearing mode are presented.EURATOM 63305

    A Comparison of Morphological, Jump, and Sprint Kinematic Asymmetries in Division I Track and Field Athletes

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    International Journal of Exercise Science 16(1): 1306-1319, 2023. Inter-limb asymmetries are the difference in performance in one limb with respect to the other. Running events in track and field are considered symmetrical while jumping and throwing events are considered asymmetrical. It is unknown if competing in these different events result in differences in inter-limb asymmetries, thus, this study compared the magnitude of jump, sprint, and morphological asymmetries in track and field athletes who compete in symmetrical and asymmetrical events. Forty-six Division I track and field athletes performed a series of vertical jumps (VJ) and broad jumps (BJ) with force platforms measuring peak force of each limb, and 30-meter fly sprints with kinematics (step length (SL), flight time (FT), and contact time (CT)) recorded during the sprints. Additionally, thirty-eight of these subjects underwent body composition analysis via dual x-ray absorptiometry to determine morphological asymmetries. Asymmetries were calculated using the symmetry index and the asymmetry measures were compared between sprinters, distance runners, throwers, and jumpers utilizing a one-way analysis of variance or Kruskal-Wallis tests with post-hoc comparisons as necessary. There were no differences in VJ, BJ, and sprint kinematic asymmetries found between groups but there were differences in leg fat mass asymmetries (H(3)=8.259, p=0.041, eta2= 0.101) as well as arm lean mass (H(3)=9.404, p=0.024, eta2=0.152), fat mass (H(3)=17.822,

    Tuning the antimicrobial behaviour of Cu 85 Zr 15 thin films in “wet” and “dry” conditions through structural modifications

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    The antimicrobial behaviour of Cu85Zr15 at.% thin films prepared by magnetron sputtering was studied in both wet and dry conditions. Small variations in key deposition processing parameters (pressure and substrate temperature) enabled the growth of thin films with similar nanostructures but different degrees of compactness, according to the Thornton's structural zone model. This model has proven its effectiveness in providing sensitive structural information to explain significant differences in antimicrobial behaviour of the CuZr thin films, even when processing conditions lie within the same structural zone. The antimicrobial behaviour has been studied for E. coli and S. aureus for up to 4 h of “dry” contact. Structures of lower compactness, grown at higher deposition pressure, are shown to provide higher antimicrobial activity for “dry” conditions than for “wet” conditions. For thin films of CuZr deposited at 0.5 Pa, the reduction percentage of bacteria is 99.47%, which is much higher than the results of 70–80% obtained for the films deposited at 0.1 and 0.3 Pa. Microscopy studies indicate that for 4 h of contact time, bacteria exhibit inner damage and even lysis, however, no morphological changes are detected because of the short timeframes used

    Atmospheric lepton fluxes at ultrahigh energies

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    In order to estimate the possibility to observe exotic physics in a neutrino telescope, it is essential to first understand the flux of atmospheric neutrinos, muons and dimuons. We study the production of these leptons by high-energy cosmic rays. We identify three main sources of muons of energy E > 10^6 GeV: the weak decay of charm and bottom mesons and the electromagnetic decay of unflavored mesons. Contrary to the standard assumption, we find that eta mesons, not the prompt decay of charm hadrons, are the dominant source of atmospheric muons at these energies. We show that, as a consequence, the ratio between the neutrino and muon fluxes is significantly reduced. For dimuons, which may be a background for long-lived staus produced near a neutrino telescope, we find that pairs of E ~ 10^7 GeV forming an angle above 10^-6 rad are produced through D (80%) or B (10%) meson decay and through Drell-Yan proceses (10%). The frequency of all these processes has been evaluated using the jet code PYTHIA.Comment: 10 pages, 4 figures; published versio

    A reversal in the obesity epidemic? A quasi-cohort and gender-oriented analysis in Spain

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    Background: The prevalence of obesity has recently stabilized in some developed countries. Some studies show this stabilization in Spain, but they do not analyse its evolution by cohort. Objective: This paper analyses the transformation of the Spanish population over time and between quasi-cohorts of weight change by age and sex. Methods: Data was taken from seven waves of the National Health Survey of Spain between 1995 and 2017, with a sample of 100,206 individuals aged 20-79 years old. Adjusted prevalence of being overweight and obesity were calculated. The changes in body mass index (BMI) by sex and age, by and between quasi-birth cohorts, and over time were analysed using test of proportions, ANOVA, and the t-test. Results: The prevalence of excessive body weight has stabilized or decreased in men since 2017 and in women since 1997. Among men, the prevalence of obesity stabilized recently and weight gain with age decreased after the 1950s cohort. Among women, mean BMI and excessive body weight decreased after the 1940s cohort. Conclusions: Our findings showed a stabilization and subsequent decrease in excessive body weight that is recent among men but took place more than two decades ago among women. Contribution: This is the first study that analyses the evolution of obesity by comparing the age-related weight gains between quasi-cohorts. This is also the first study that analyses the stabilization of excessive body weight in Spain by quasi-cohort, age, and sex, and that shows that this stabilization is due to a bigger weight control among the older cohorts in the older ages

    Efficacy of a Deep Learning Convolutional Neural Network System for Melanoma Diagnosis in a Hospital Population

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    The purpose of this study was to evaluate the efficacy in terms of sensitivity, specificity, and accuracy of the quantusSKIN system, a new clinical tool based on deep learning, to distinguish between benign skin lesions and melanoma in a hospital population. (2) Methods: A retrospective study was performed using 232 dermoscopic images from the clinical database of the Ramón y Cajal University Hospital (Madrid, Spain). The skin lesions images, previously diagnosed as nevus (n = 177) or melanoma (n = 55), were analyzed by the quantusSKIN system, which offers a probabilistic percentage (diagnostic threshold) for melanoma diagnosis. The optimum diagnostic threshold, sensitivity, specificity, and accuracy of the quantusSKIN system to diagnose melanoma were quantified. (3) Results: The mean diagnostic threshold was statistically lower (p < 0.001) in the nevus group (27.12 ± 35.44%) compared with the melanoma group (72.50 ± 34.03%). The area under the ROC curve was 0.813. For a diagnostic threshold of 67.33%, a sensitivity of 0.691, a specificity of 0.802, and an accuracy of 0.776 were obtained. (4) Conclusions: The quantusSKIN system is proposed as a useful screening tool for melanoma detection to be incorporated in primary health care systems.Depto. de Optometría y VisiónFac. de Óptica y OptometríaTRUEpu

    Number of prior episodes and the presence of depressive symptoms are associated with longer length of stay for patients with acute manic episodes

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    <p>Abstract</p> <p>Background</p> <p>Few studies have analyzed predictors of length of stay (LOS) in patients admitted due to acute bipolar manic episodes. The purpose of the present study was to estimate LOS and to determine the potential sociodemographic and clinical risk factors associated with a longer hospitalization. Such information could be useful to identify those patients at high risk for long LOS and to allocate them to special treatments, with the aim of optimizing their hospital management.</p> <p>Methods</p> <p>This was a cross-sectional study recruiting adult patients with a diagnosis of bipolar disorder (<it>Diagnostic and Statistical Manual of Mental Disorders</it>, 4th edition, text revision (DSM-IV-TR) criteria) who had been hospitalized due to an acute manic episode with a Young Mania Rating Scale total score greater than 20. Bivariate correlational and multiple linear regression analyses were performed to identify independent predictors of LOS.</p> <p>Results</p> <p>A total of 235 patients from 44 centers were included in the study. The only factors that were significantly associated to LOS in the regression model were the number of previous episodes and the Montgomery-Ă…sberg Depression Rating Scale (MADRS) total score at admission (<it>P </it>< 0.05).</p> <p>Conclusions</p> <p>Patients with a high number of previous episodes and those with depressive symptoms during mania are more likely to stay longer in hospital. Patients with severe depressive symptoms may have a more severe or treatment-resistant course of the acute bipolar manic episode.</p
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