70 research outputs found

    Los conductores re-examinados: El transcurso del tiempo deteriora significativamente los conocimientos de los conductores

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    Dos mil cinco conductores, 1204 hombres y 801 mujeres,una muestra representativa de la población española deconductores, fueron nuevamente examinados utilizandoun cuestionario que reproducía fielmente un examen deconducir realizado por la Dirección General de Tráfico(DGT). Las preguntas fueron clasificadas en “muyimportantes”, “importantes” y “poco importantes”. El 96.5% de los conductores, suspendió el examen. Los resultadoseran tanto peores cuanto más tiempo había transcurridodesde la obtención del permiso de conducir. Esto eraindependiente de la importancia de las preguntas, de lamayor o menor frecuencia de conducción y afectaba porigual a hombres y mujeres. Las mujeres obtienen mejorespuntuaciones en señalización mientras que los hombres sonmejores en las preguntas de seguridad vial. Los resultadostambién demostraban que los conductores profesionales y los de mayor nivel educativo sufren un menor deterioro.Tales resultados nos llevan a considerar la relación que estosdatos puedan tener en los niveles de accidentalidad y laconveniencia de establecer pautas para la actualización delconocimiento de los conductores. Finalmente, se discutela relevancia que el examen que se utiliza para obtener elpermiso de conducir tiene como indicador o predictorde una futura conducción segura

    Evaluación de la calidad de la experiencia para servicios de datos móviles

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    La calidad de la experiencia (QoE) percibida por los usuarios móviles juega un papel importante en el posicionamiento de las empresas de telecomunicaciones y en la fidelidad de los usuarios. Además, puede ser considerada como una métrica clave en la gestión de recursos de red. Por esta razón, este trabajo se enfoca en el establecimiento de un modelo estimación del QoE considerando parámetros a nivel de red, dispositivo y aplicación para el contexto de uso de video streaming. Para este fin, se implementan una plataforma de transmisión de datos móviles y una aplicación Android que son utilizadas durante el proceso de recolección de datos. Los datos obtenidos en dicho proceso se emplean como entrada de distintos algoritmos de aprendizaje automático, cuyos desempeños son comparados con el fin de identificar a los más adecuados para la creación de un modelo que permita estimar el QoE en el contexto de uso mencionado.X Workshop Arquitectura, Redes y Sistemas Operativos (WARSO)Red de Universidades con Carreras en Informática (RedUNCI

    Evaluación de la calidad de la experiencia para servicios de datos móviles

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    La calidad de la experiencia (QoE) percibida por los usuarios móviles juega un papel importante en el posicionamiento de las empresas de telecomunicaciones y en la fidelidad de los usuarios. Además, puede ser considerada como una métrica clave en la gestión de recursos de red. Por esta razón, este trabajo se enfoca en el establecimiento de un modelo estimación del QoE considerando parámetros a nivel de red, dispositivo y aplicación para el contexto de uso de video streaming. Para este fin, se implementan una plataforma de transmisión de datos móviles y una aplicación Android que son utilizadas durante el proceso de recolección de datos. Los datos obtenidos en dicho proceso se emplean como entrada de distintos algoritmos de aprendizaje automático, cuyos desempeños son comparados con el fin de identificar a los más adecuados para la creación de un modelo que permita estimar el QoE en el contexto de uso mencionado.X Workshop Arquitectura, Redes y Sistemas Operativos (WARSO)Red de Universidades con Carreras en Informática (RedUNCI

    Evaluación de la calidad de la experiencia para servicios de datos móviles

    Get PDF
    La calidad de la experiencia (QoE) percibida por los usuarios móviles juega un papel importante en el posicionamiento de las empresas de telecomunicaciones y en la fidelidad de los usuarios. Además, puede ser considerada como una métrica clave en la gestión de recursos de red. Por esta razón, este trabajo se enfoca en el establecimiento de un modelo estimación del QoE considerando parámetros a nivel de red, dispositivo y aplicación para el contexto de uso de video streaming. Para este fin, se implementan una plataforma de transmisión de datos móviles y una aplicación Android que son utilizadas durante el proceso de recolección de datos. Los datos obtenidos en dicho proceso se emplean como entrada de distintos algoritmos de aprendizaje automático, cuyos desempeños son comparados con el fin de identificar a los más adecuados para la creación de un modelo que permita estimar el QoE en el contexto de uso mencionado.X Workshop Arquitectura, Redes y Sistemas Operativos (WARSO)Red de Universidades con Carreras en Informática (RedUNCI

    Computer-assisted evaluation of sperm vitality in humans

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    En la actualidad una de cada seis parejas presenta problemas de fertilidad y en el 50% de los casos se debe al factor masculino. A la fecha, el análisis seminal es la única prueba que permite determinar el potencial fértil de un hombre. Entre otros parámetros, la viabilidad espermática es evaluada manualmente presentando una variabilidad debido a la subjetividad producida por la fatiga ocular del experto. El propósito de este trabajo fue desarrollar y validar experimentalmente una herramienta computacional flexible, programable y modular basada en el procesamiento digital de imágenes, para la identificación y clasificación de espermatozoides humanos en una muestra seminal. Las regiones fueron extraídas mediante la técnica de análisis discriminante de Fisher y su clasificación se realizó a través del análisis de agrupamiento y particularmente la técnica de K-medias. Los resultados obtenidos muestran 87,9% de exactitud en la identificación de los espermatozoides vivos y los espermatozoides muertos, 93,4% de efectividad para detectar espermatozoides vivos y 76% de efectividad para detectar los espermatozoides muertos, a partir de un conjunto de 110 imágenes obtenidas de 14 individuos, en comparación con el análisis manual acorde a los procedimientos establecidos por la Organización Mundial de la Salud. La herramienta computacional mostrada aquí contribuye al análisis objetivo de espermatozoides humanos, convirtiéndose en una alternativa a los costosos sistemas comerciales de análisis seminal asistido por computador.Currently one out of six couples present fertility problems, with 50% of the cases being due to the male. Until now, seminal fluid analysis is the only test that evaluates a male’s fertility potential. Among other parameters, sperm viability is manually assessed, which contributes to high data variability as a result of expert subjectivity and eye-fatigue. The purpose of the present study was to develop and experimentally validate a flexible, programmable and modular-based computational tool for digital image processing, identification and classification of human sperm in a semen sample. The regions were extracted using Fisher discriminant analysis and classification methods by cluster analysis and particularly the K-means technique. The results show 87.9% accuracy in identifying living and dead sperm, 93.4% effectiveness in detecting live sperm and 76% effectiveness in detecting dead sperm, from a set of 110 images obtained from 14 individuals, compared with manual analysis according to the procedures established by the World Health Organization. This computational tool contributes to the objective analysis of human sperm, becoming an alternative to expensive commercial systems for computer-assisted semen analysi

    Height and timing of growth spurt during puberty in young people living with vertically acquired HIV in Europe and Thailand.

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    OBJECTIVE: The aim of this study was to describe growth during puberty in young people with vertically acquired HIV. DESIGN: Pooled data from 12 paediatric HIV cohorts in Europe and Thailand. METHODS: One thousand and ninety-four children initiating a nonnucleoside reverse transcriptase inhibitor or boosted protease inhibitor based regimen aged 1-10 years were included. Super Imposition by Translation And Rotation (SITAR) models described growth from age 8 years using three parameters (average height, timing and shape of the growth spurt), dependent on age and height-for-age z-score (HAZ) (WHO references) at antiretroviral therapy (ART) initiation. Multivariate regression explored characteristics associated with these three parameters. RESULTS: At ART initiation, median age and HAZ was 6.4 [interquartile range (IQR): 2.8, 9.0] years and -1.2 (IQR: -2.3 to -0.2), respectively. Median follow-up was 9.1 (IQR: 6.9, 11.4) years. In girls, older age and lower HAZ at ART initiation were independently associated with a growth spurt which occurred 0.41 (95% confidence interval 0.20-0.62) years later in children starting ART age 6 to 10 years compared with 1 to 2 years and 1.50 (1.21-1.78) years later in those starting with HAZ less than -3 compared with HAZ at least -1. Later growth spurts in girls resulted in continued height growth into later adolescence. In boys starting ART with HAZ less than -1, growth spurts were later in children starting ART in the oldest age group, but for HAZ at least -1, there was no association with age. Girls and boys who initiated ART with HAZ at least -1 maintained a similar height to the WHO reference mean. CONCLUSION: Stunting at ART initiation was associated with later growth spurts in girls. Children with HAZ at least -1 at ART initiation grew in height at the level expected in HIV negative children of a comparable age

    Macoilin, a Conserved Nervous System–Specific ER Membrane Protein That Regulates Neuronal Excitability

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    Genome sequence comparisons have highlighted many novel gene families that are conserved across animal phyla but whose biological function is unknown. Here, we functionally characterize a member of one such family, the macoilins. Macoilins are characterized by several highly conserved predicted transmembrane domains towards the N-terminus and by coiled-coil regions C-terminally. They are found throughout Eumetazoa but not in other organisms. Mutants for the single Caenorhabditis elegans macoilin, maco-1, exhibit a constellation of behavioral phenotypes, including defects in aggregation, O2 responses, and swimming. MACO-1 protein is expressed broadly and specifically in the nervous system and localizes to the rough endoplasmic reticulum; it is excluded from dendrites and axons. Apart from subtle synapse defects, nervous system development appears wild-type in maco-1 mutants. However, maco-1 animals are resistant to the cholinesterase inhibitor aldicarb and sensitive to levamisole, suggesting pre-synaptic defects. Using in vivo imaging, we show that macoilin is required to evoke Ca2+ transients, at least in some neurons: in maco-1 mutants the O2-sensing neuron PQR is unable to generate a Ca2+ response to a rise in O2. By genetically disrupting neurotransmission, we show that pre-synaptic input is not necessary for PQR to respond to O2, indicating that the response is mediated by cell-intrinsic sensory transduction and amplification. Disrupting the sodium leak channels NCA-1/NCA-2, or the N-,P/Q,R-type voltage-gated Ca2+ channels, also fails to disrupt Ca2+ responses in the PQR cell body to O2 stimuli. By contrast, mutations in egl-19, which encodes the only Caenorhabditis elegans L-type voltage-gated Ca2+ channel α1 subunit, recapitulate the Ca2+ response defect we see in maco-1 mutants, although we do not see defects in localization of EGL-19. Together, our data suggest that macoilin acts in the ER to regulate assembly or traffic of ion channels or ion channel regulators

    Impact of the first wave of the SARS-CoV-2 pandemic on the outcome of neurosurgical patients: A nationwide study in Spain

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    Objective To assess the effect of the first wave of the SARS-CoV-2 pandemic on the outcome of neurosurgical patients in Spain. Settings The initial flood of COVID-19 patients overwhelmed an unprepared healthcare system. Different measures were taken to deal with this overburden. The effect of these measures on neurosurgical patients, as well as the effect of COVID-19 itself, has not been thoroughly studied. Participants This was a multicentre, nationwide, observational retrospective study of patients who underwent any neurosurgical operation from March to July 2020. Interventions An exploratory factorial analysis was performed to select the most relevant variables of the sample. Primary and secondary outcome measures Univariate and multivariate analyses were performed to identify independent predictors of mortality and postoperative SARS-CoV-2 infection. Results Sixteen hospitals registered 1677 operated patients. The overall mortality was 6.4%, and 2.9% (44 patients) suffered a perioperative SARS-CoV-2 infection. Of those infections, 24 were diagnosed postoperatively. Age (OR 1.05), perioperative SARS-CoV-2 infection (OR 4.7), community COVID-19 incidence (cases/10 5 people/week) (OR 1.006), postoperative neurological worsening (OR 5.9), postoperative need for airway support (OR 5.38), ASA grade =3 (OR 2.5) and preoperative GCS 3-8 (OR 2.82) were independently associated with mortality. For SARS-CoV-2 postoperative infection, screening swab test <72 hours preoperatively (OR 0.76), community COVID-19 incidence (cases/10 5 people/week) (OR 1.011), preoperative cognitive impairment (OR 2.784), postoperative sepsis (OR 3.807) and an absence of postoperative complications (OR 0.188) were independently associated. Conclusions Perioperative SARS-CoV-2 infection in neurosurgical patients was associated with an increase in mortality by almost fivefold. Community COVID-19 incidence (cases/10 5 people/week) was a statistically independent predictor of mortality. Trial registration number CEIM 20/217

    Children living with HIV in Europe: do migrants have worse treatment outcomes?

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    Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

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    The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality
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