318 research outputs found
Robust outlier detection in high-density surface electromyographic signals
Conf Proc IEEE Eng Med Biol Soc. 2010;2010:4850-3. PubMed PMID: 2109664
Real-time gaze estimation using a Kinect and a HD webcam
In human-computer interaction, gaze orientation is an important and promising source of information to demonstrate the attention and focus of users. Gaze detection can also be an extremely useful metric for analysing human mood and affect. Furthermore, gaze can be used as an input method for human-computer interaction. However, currently real-time and accurate gaze estimation is still an open problem. In this paper, we propose a simple and novel estimation model of the real-time gaze direction of a user on a computer screen. This method utilises cheap capturing devices, a HD webcam and a Microsoft Kinect. We consider that the gaze motion from a user facing forwards is composed of the local gaze motion shifted by eye motion and the global gaze motion driven by face motion. We validate our proposed model of gaze estimation and provide experimental evaluation of the reliability and the precision of the method
Arsenic in Latin America
An overview about the presence of arsenic (As) in waters of Latin America (LA) is presented. Aspects on As occurrence, effects of As on human health, regulations regarding the maximum allowable concentration of As in drinking water, analytical techniques for As determination, and conventional/emerging technologies for As removal developed in LA are indicated. Arsenic presence has been identified in many LA countries in a range of concentrations, originated from various sources; however, its origin is mainly natural. Main analytical techniques available in LA laboratories are described. Pathologies derived from the chronic consumption of As, the metabolism of As in the human body and the effects of the different As chemical forms are detailed. A list of conventional and emerging technologies for As removal in LA waters for human consumption, for large, medium and small populations, rural and periurban, is reported. Conclusions and recommendations to face the problem are included.Fil: Litter, Marta Irene. Comisión Nacional de Energía Atómica; Argentina. Universidad Nacional de San Martín. Instituto de Investigación e Ingeniería Ambiental. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación e Ingeniería Ambiental; ArgentinaFil: Armienta, M.A.. Universidad Nacional Autónoma de México; MéxicoFil: Villanueva Estrada, Ruth E.. Universidad Nacional Autónoma de México; MéxicoFil: Villaamil Lepori, Edda. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Laboratorio de Toxicología y Química Legal; ArgentinaFil: Olmos, Valentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Laboratorio de Toxicología y Química Legal; Argentin
Tracing sulfate recycling in the hypersaline Pétrola lake (SE Spain): A combined isotopic and microbiological approach
Sulfur (S) plays a significant role in saline environments, and sulfate (SO4 2−) is an important component of the biogeochemical S-cycle since it acts as the main electron acceptor in anoxic sediments. The purpose of this paper is to evaluate the fate of S, its origin, and processes affecting sulfate outcome in the hypersaline Pétrola Lake in the Castilla-La Mancha region (High Segura Basin, SE Spain). The lake is the terminal discharge zone of an endorheic basin with considerable anthropogenic pressures. Anthropogenic activities (mainly agricultural inputs and wastewater discharge), together with bedrock leaching of sulfate and sulfide-rich sediments, increase dissolved SO4 2− in surface and groundwater up to 123,000 mg/L. The source and fate of sulfate in this environment was investigated coupling hydrochemistry, including hydrogen sulfide (H2S) microprofiles, isotopic analyses (δ34S, δ18OSO4, δ2HH2O, δ18OH2O, and tritium), mineralogical determinations, and molecular biology tools (16S rDNA amplification and sequencing). The origin of dissolved SO4 2− in water is related to pyrite oxidation from Lower Cretaceous sediments, and secondary gypsum dissolution. Under the lake, dissolved SO4 2− decreases with depth, controlled by three main processes: (1) seasonal evaporation cycles, (2) hydrodynamic instability caused by the different density-driven groundwater flow, and (3) sulfate-reduction processes, i.e. dissimilatory bacterial sulfate reduction (BSR). These processes control the continuous recycling of sulfur in the system. Lake water and groundwater are in hydraulic connection, and a density-driven flow (DDF) is able to transport reactive organic matter and dissolved SO4 2− towards the underlying aquifer. Hydrochemical evolution in depth, H2S production (up to 0.024 nmol/cm3·s) and the presence of sulfate-reducing bacteria suggest the existence of BSR processes. However, isotope techniques are insufficient to elucidate BSR processes since their isotopic effect is masked by low isotope fractionation and high SO4 2− concentrations. The pattern here described may be found in other saline basins worldwide
PhaseGAN a deep learning phase retrieval approach for unpaired datasets
Phase retrieval approaches based on deep learning DL provide a framework to obtain phase information from an intensity hologram or diffraction pattern in a robust manner and in real time. However, current DL architectures applied to the phase problem rely on i paired datasets, i. e., they are only applicable when a satisfactory solution of the phase problem has been found, and ii the fact that most of them ignore the physics of the imaging process. Here, we present PhaseGAN, a new DL approach based on Generative Adversarial Networks, which allows the use of unpaired datasets and includes the physics of image formation. The performance of our approach is enhanced by including the image formation physics and a novel Fourier loss function, providing phase reconstructions when conventional phase retrieval algorithms fail, such as ultra fast experiments. Thus, PhaseGAN offers the opportunity to address the phase problem in real time when no phase reconstructions but good simulations or data from other experiments are availabl
Multiparametric renal magnetic resonance imaging: A reproducibility study in renal allografts with stable function
Monitoring renal allograft function after transplantation is key for the early detection of allograft impairment, which in turn can contribute to preventing the loss of the allograft. Multiparametric renal MRI (mpMRI) is a promising noninvasive technique to assess and characterize renal physiopathology; however, few studies have employed mpMRI in renal allografts with stable function (maintained function over a long time period). The purposes of the current study were to evaluate the reproducibility of mpMRI in transplant patients and to characterize normal values of the measured parameters, and to estimate the labeling efficiency of Pseudo-Continuous Arterial Spin Labeling (PCASL) in the infrarenal aorta using numerical simulations considering experimental measurements of aortic blood flow profiles. The subjects were 20 transplant patients with stable kidney function, maintained over 1 year. The MRI protocol consisted of PCASL, intravoxel incoherent motion, and T1 inversion recovery. Phase contrast was used to measure aortic blood flow. Renal blood flow (RBF), diffusion coefficient (D), pseudo-diffusion coefficient (D*), flowing fraction (
f
), and T1 maps were calculated and mean values were measured in the cortex and medulla. The labeling efficiency of PCASL was estimated from simulation of Bloch equations. Reproducibility was assessed with the within-subject coefficient of variation, intraclass correlation coefficient, and Bland-Altman analysis. Correlations were evaluated using the Pearson correlation coefficient. The significance level was p less than 0.05. Cortical reproducibility was very good for T1, D, and RBF, moderate for
f
, and low for D*, while medullary reproducibility was good for T1 and D. Significant correlations in the cortex between RBF and
f
(r = 0.66), RBF and eGFR (r = 0.64), and D* and eGFR (r = -0.57) were found. Normal values of the measured parameters employing the mpMRI protocol in kidney transplant patients with stable function were characterized and the results showed good reproducibility of the techniques
Supervivencia del injerto tras trasplante hepático: aproximación a un nuevo índice de riesgo español
Introducción: existen diversos indicadores para la valoración de la supervivencia del injerto hepático (DRI americano y ET-DRI europeo, entre otros), pero existen diferencias importantes entre los programas de trasplante de los diferentes países y podría ser que dichos indicadores no sean válidos en nuestro medio.
Objetivos: el objetivo de este estudio es describir un nuevo indicador nacional de riesgo del injerto hepático a partir de los resultados del Registro Español de Trasplante Hepático (RETH) y validar el DRI y el ET-DRI. Metodología: el RETH incluye un análisis de Cox de los factores relacionados con la supervivencia del injerto. En base a sus resultados se define el indicador graft risk index (GRI). Las variables que contempla dependen del proceso de donación: edad, causa de muerte, compatibilidad sanguínea y tiempo de isquemia fría; y del receptor: edad, enfermedad de base, virus C, número de trasplante, estado UNOS y técnica quirúrgica. Se obtuvo la curva de la regresión logística y se calcularon las curvas de supervivencia del injerto por estratificación. La precisión se evaluó mediante el área ROC.
Resultados: un GRI de 1 se corresponde con una probabilidad de pérdida del injerto del 23, 25%; cada punto de aumento del GRI supone que la probabilidad se multiplica por 1, 33. El GRI mostró la mejor discriminación por estratificación. El área ROC del DRI fue 0, 54 (95% IC, 0, 50-0, 59) y del ET-DRI, 0, 56 (95% IC, 0, 51-0, 61), frente al GRI 0, 70 (95% IC, 0, 65-0, 73) (p < 0, 0001).
Conclusiones: el DRI y el ET-DRI no parecen útiles en nuestro medio y sería necesario disponer de un indicador propio. El GRI requiere un estudio nacional que perfile más el indicador y realice una validación más amplia.
Introduction: several indicators are available to assess liver graft survival, including the American DRI and the European ET-DRI. However, there are significant differences between transplant programs of different countries, and the previously mentioned indicators might be not valid in our setting.
Objectives: the aim of the study was to describe a new national liver graft risk indicator based on the results obtained from the Registro Espanol de Trasplante Hepatico (RETH) and to validate the DRI and ET-DRI indicators.
Methods: the RETH includes a Cox analysis of factors associated with graft survival; the graft risk index (GRI) indicator was defined based on these results. The variables considered are dependent upon the donation conditions (age, cause of death, blood compatibility and cold ischemia time) and the transplant recipient (age, underlying disease, hepatitis C virus, transplant number, UNOS status and surgical technique). A logistic regression curve was obtained and graft survival curves were calculated by stratification. Precision was assessed using the ROC analysis.
Results: a GRI of 1 represents a probability of graft loss of 23.25%; each point increase in the GRI score multiplies this probability by 1.33. The best discrimination of GRI was obtained by stratification.The DRI ROC area was 0.54 (95% CI, 0.50-0.59) and the ET-DRI ROC area was 0.56 (95% CI, 0.51-0.61), compared to 0.70 (95% CI, 0.65-0.73) (p < 0.0001) for the GRI.
Conclusions: both the DRI and ET-DRI do not seem to be useful in our setting. Hence a national indicator is more desirable.The GRI requires a national study in order to further streamline and assess this indicator
Impacto del teletrabajo en el nivel de compromiso laboral (engagement) y de agotamiento de los docentes del Tecnológico Nacional de México en la pandemia COVID 19 y el retorno a la nueva normalidad.
This article have the purpose to determinate the impact that was had on the teachers of the National Technological Institute of Mexico in terms of the level of their commitment and exhaustion work during the times of COVID-19 pandemic, performing their teaching function throught teleworking, to carry out this study to work was carried out in collaboration with CIRCULAR HR Fundación Chile y UNESCO WHEC (World Higher Education Conference 2022), 1994 surveys were applied to teachers of all the categories of the Technological System. This instrument was applied in different universities convened by UNESCO, in total were 3351 surveys and the Technological System help the 59.5% of the information for this study. As part of the results obtained, it was found that if there were differences on the level of exhaustion depending on the main function of each teaching category and the gender, but the level of commitment remained the same regardless of seniority, gender or category in which teacher was.El presente artículo tiene como finalidad determinar cuál fue el impacto que se tuvo en los docentes del Tecnológico Nacional de México en cuanto a su nivel de compromiso y el agotamiento laboral durante los tiempos de pandemia COVID-19 realizando su funciones docentes a través del teletrabajo, para llevar a cabo este estudio se trabajó en colaboración con CIRCULAR HR Fundación Chile Y UNESCO WHEC (World Higher Education Conference 2022), se aplicaron 1994 encuestas a docentes de todas las categorías del Sistema Tecnológico. Este instrumento fue aplicado a diferentes universidades convocadas por la UNESCO, en total fueron 3351 encuestas y el Sistema Tecnológico aportó el 59.5% de la información para este estudio. Como parte de los resultados obtenidos se encontró que si hay diferencias en nivel de agotamiento dependiendo de la función principal de cada categoría docente y el género, pero el nivel de compromiso se mantenía igual independientemente de la antigüedad, género o categoría en la que estuviera el docente
Role of targeted therapies in rheumatic patients on COVID-19 outcomes: Results from the COVIDSER study
Objectives To analyse the effect of targeted therapies, either biological (b) disease-modifying antirheumatic drugs (DMARDs), targeted synthetic (ts) DMARDs and other factors (demographics, comorbidities or COVID-19 symptoms) on the risk of COVID-19 related hospitalisation in patients with inflammatory rheumatic diseases. Methods The COVIDSER study is an observational cohort including 7782 patients with inflammatory rheumatic diseases. Multivariable logistic regression was used to estimate ORs and 95% CIs of hospitalisation. Antirheumatic medication taken immediately prior to infection, demographic characteristics, rheumatic disease diagnosis, comorbidities and COVID-19 symptoms were analysed. Results A total of 426 cases of symptomatic COVID-19 from 1 March 2020 to 13 April 2021 were included in the analyses: 106 (24.9%) were hospitalised and 19 (4.4%) died. In multivariate-adjusted models, bDMARDs and tsDMARDs in combination were not associated with hospitalisation compared with conventional synthetic DMARDs (OR 0.55, 95% CI 0.24 to 1.25 of b/tsDMARDs, p=0.15). Tumour necrosis factor inhibitors (TNF-i) were associated with a reduced likelihood of hospitalisation (OR 0.32, 95% CI 0.12 to 0.82, p=0.018), whereas rituximab showed a tendency to an increased risk of hospitalisation (OR 4.85, 95% CI 0.86 to 27.2). Glucocorticoid use was not associated with hospitalisation (OR 1.69, 95% CI 0.81 to 3.55). A mix of sociodemographic factors, comorbidities and COVID-19 symptoms contribute to patients'' hospitalisation. Conclusions The use of targeted therapies as a group is not associated with COVID-19 severity, except for rituximab, which shows a trend towards an increased risk of hospitalisation, while TNF-i was associated with decreased odds of hospitalisation in patients with rheumatic disease. Other factors like age, male gender, comorbidities and COVID-19 symptoms do play a role.
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