52 research outputs found

    Selección de tutores académicos en la educación superior usando árboles de decisión

    Get PDF
    ABSTRACTIn this paper, we present a method for the tutoring process in order to improve academic tutoring in higher education. The method includes identifying the main skills of tutors in an automated manner using decision trees, one of the most used algorithms in the machine learning community for solving several real-world problems with high accuracy. In our study, the decision tree algorithm was able to identify those skills and personal affinities between students and tutors. Experiments were carried out using a data set of 277 students and 19 tutors, which were selected by random sampling and voluntary participation, respectively. Preliminary results show that the most important attributes for tutors are communication, self-direction and digital skills. At the same time, we introduce a tutoring process where the tutor assignment is based on these attributes, assuming that it can help to strengthen the student's skills demanded by today's society. In the same way, the decision tree obtained can be used to create cluster of tutors and clusters of students based on their personal abilities and affinities using other machine learning algorithms. The application of the suggested tutoring process could set the tone to see the tutoring process individually without linking it to processes of academic performance or school dropout.RESUMEN  En este documento se presenta un método para mejorar el proceso de tutoría académica en la educación superior. El método incluye a identificación de las habilidades principales de los tutores de forma automática utilizando el algoritmo árboles de decisión, uno de los algoritmos más utilizados en la comunidad de aprendizaje automático para resolver problemas del mundo real con gran precisión. En el estudio, el algoritmo arboles de decisión fue capaz de identificar las habilidades y afinidades entre estudiantes y tutores. Los experimentos se llevaron a cabo utilizando un conjunto de datos de 277 estudiantes y 19 tutores, mismos que fueron seleccionados por muestreo aleatorio simple y participación voluntaria en el caso de los tutores. Los resultados preliminares muestran que los atributos más importantes para los tutores son la comunicación, la autodirección y las habilidades digitales. Al mismo tiempo, se presenta un proceso de tutoría en el que la asignación del tutor se basa en estos atributos, asumiendo que puede ayudar a fortalecer las habilidades de los estudiantes que demanda la sociedad actual. De la misma forma, el árbol de decisión obtenido se puede utilizar para agrupar a tutores y estudiantes basados en sus habilidades y afinidades personales utilizando otros algoritmos de aprendizaje automático. La aplicación del proceso de tutoría sugerido podría dar la pauta para ver el proceso de tutoría de manera individual sin vincularla a procesos de desempeño académico o deserción escolar.ABSTRACTIn this paper, we present a method for the tutoring process in order to improve academic tutoring in higher education. The method includes identifying the main skills of tutors in an automated manner using decision trees, one of the most used algorithms in the machine learning community for solving several real-world problems with high accuracy. In our study, the decision tree algorithm was able to identify those skills and personal affinities between students and tutors. Experiments were carried out using a data set of 277 students and 19 tutors, which were selected by random sampling and voluntary participation, respectively. Preliminary results show that the most important attributes for tutors are communication, self-direction and digital skills. At the same time, we introduce a tutoring process where the tutor assignment is based on these attributes, assuming that it can help to strengthen the student's skills demanded by today's society. In the same way, the decision tree obtained can be used to create cluster of tutors and clusters of students based on their personal abilities and affinities using other machine learning algorithms. The application of the suggested tutoring process could set the tone to see the tutoring process individually without linking it to processes of academic performance or school dropout

    Oral anticoagulation in elderly patients as secondary prevention of cardioembolic strokes

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Stroke incidence increases with age. Atrial fibrillation (AF) is an important risk factor for ischemic stroke and its incidence also increases with age. However oral anticoagulant therapy (OAT) tends to be underused in the elderly population.</p> <p>Methods</p> <p>Elderly patients (> = 80 years) with an ischemic stroke admitted in our department between 1/7/2003 and 31/6/2005 were prospectively evaluated. Baseline characteristics, risk factors, treatment and etiology according to TOAST criteria were recorded. Patients treated with OAT were followed up in order to assess any side effect and stroke recurrence. Mean follow-up was of 19.5 months (7-45) from discharge.</p> <p>Results</p> <p>Sixty four out of a hundred and fifty nine elderly patients (40.25%) were classified as cardioembolic; mean age was 84.5 years (80-97) and 64.6% were women. AF had been previously identified in 60% of them (16.9% were on OAT and 40.6% on antiplatelet therapy). At discharge, 32 patients (49.2%) were on OAT. In the follow-up 4 patients (12.5%) suffered systemic haemorrhages (3 urinary, 1 gastrointestinal bleeding), with no change in their functional status. Mean INR in this group was 5.9 <abbrgrp><abbr bid="B3">3</abbr><abbr bid="B4">4</abbr><abbr bid="B5">5</abbr><abbr bid="B6">6</abbr><abbr bid="B7">7</abbr><abbr bid="B8">8</abbr><abbr bid="B9">9</abbr><abbr bid="B10">10</abbr><abbr bid="B11">11</abbr></abbrgrp> and, in 3 of them, OAT was cancelled. No brain haemorrhages were recorded. Ischemic stroke recurred in 4 patients (INR < 1.8 in 3 of them; the other, INR 2.35). Three patients had died at the end of the follow-up, one of them as a consequence of ischemic stroke recurrence.</p> <p>Discussion</p> <p>Twenty eight point eight of stroke patients admitted in the period of study were >80 years. The high proportion of cardioembolic strokes in this age segment contrasts with the general underuse of OAT as antithrombotic prophylaxis. Our study suggests that OAT is a safe strategy when carefully prescribed, even for elderly patients.</p

    ANIMACIÓN DE UN MODELO 3D DEL ROBOT DARWIN-OP UTILIZANDO KINECT

    Get PDF
    Este documento describe herramientas relacionadas con la creación de video juegos, principalmente aquellas que soportan tareas como diseño y animación, con el propósito de integrar una representación gráfica en tres dimensiones del robot humanoide Darwin-OP. El objetivo se logra al animar esta representación mediante la incorporación de un esqueleto y el establecimiento de una conexión con el sensor movimientos de un Kinect. Los resultados iniciales de esta investigación de tipo exploratoria, muestran la factibilidad de animar articulaciones específicas de un personaje virtual a través de un dispositivo relativamente accesible.

    Inicialización de un robot humanoide tipo BIOLOID para tareas de caminado

    Get PDF
    El presente trabajo describe el desarrollo de rutinas de comportamiento reactivo para un robot humanoide con 16 articulaciones. Específicamente, esta enfocado a llevar a un robot humanoide a una configuración inicial que le permita poder ejecutar cualquier tipo de rutina de locomoción. Todos estos comportamientos dependen de la programación de servomotores así como del uso de un sensor de giro o giroscopio. Con este sensor se determina a través de un evento si el robot perdió la vertical y ha caído al piso, en cuyo caso ejecuta una rutina para llevar al robot nuevamente a una configuración que le permita continuar con su operación. El trabajo esta soportado en un proceso experimental para llegar a obtener un conjunto de parámetros que aseguran el buen funcionamiento de las rutinas, como son las velocidades de operación y valores que arroja el sensor de giro. Los resultados son muy satisfactorios tomando en cuenta que para los robots bípedos o humanoides es muy fácil que pierdan el equilibrio dadas las distintas rutinas de locomoción que se implementan y que provocan la caída del robot.Así, esta propuesta permite estar censando el estado del robot para que en cuanto éste caiga al suelo ejecute alguna de las dos rutinas de reincorporación propuestas.Palabra(s) Clave(s): robótica reactiva, robots bípedos, sensores

    Potential-density pairs for axisymmetric galaxies: the influence of scalar fields

    Full text link
    We present a formulation for potential-density pairs to describe axisymmetric galaxies in the Newtonian limit of scalar-tensor theories of gravity. The scalar field is described by a modified Helmholtz equation with a source that is coupled to the standard Poisson equation of Newtonian gravity. The net gravitational force is given by two contributions: the standard Newtonian potential plus a term stemming from massive scalar fields. General solutions have been found for axisymmetric systems and the multipole expansion of the Yukawa potential is given. In particular, we have computed potential-density pairs of galactic disks for an exponential profile and their rotation curves.Comment: 8 pages, no figures, corrected version to the one that will appear in Gen. Relativ. Gravit., where a small typo in eq. (13) is presen

    Super-Resolution Microscopy Using a Bioorthogonal-Based Cholesterol Probe Provides Unprecedented Capabilities for Imaging Nanoscale Lipid Heterogeneity in Living Cells

    Get PDF
    Despite more than 20 years of work since the lipid raft concept was proposed, the existence of these nanostructures remains highly controversial due to the lack of noninvasive methods to investigate their native nanorganization in living unperturbed cells. There is an unmet need for probes for direct imaging of nanoscale membrane dynamics with high spatial and temporal resolution in living cells. In this paper, a bioorthogonal-based cholesterol probe (chol-N-3) is developed that, combined with nanoscopy, becomes a new powerful method for direct visualization and characterization of lipid raft at unprecedented resolution in living cells. The chol-N-3 probe mimics cholesterol in synthetic and cellular membranes without perturbation. When combined with live-cell super-resolution microscopy, chol-N-3 demonstrates the existence of cholesterol-rich nanodomains of <50 nm at the plasma membrane of resting living cells. Using this tool, the lipid membrane structure of such subdiffraction limit domains is identified, and the nanoscale spatiotemporal organization of cholesterol in the plasma membrane of living cells reveals multiple cholesterol diffusion modes at different spatial localizations. Finally, imaging across thick organ samples outlines the potential of this new method to address essential biological questions that were previously beyond reach.M.L., O.T., and J.A.N.-G. contributed equally to this work. This work was supported by grants from the Spanish Ministry of Science Innovation and Universities, (Grant No. BFU-2015-68981-P) and the Basque Government (Grant No. IT1264-19) to F.-X.C. and M.L.. The authors thank J. M. Gonzalez Manas and Sergio Perez Acebron for helful comments on the manuscript. The authors thank the technical and human support provided by the analytical and high-resolution microscopy facility (SGIker) of UPV/EHU and European funding (ERDF and ESF). J.B.d.l.S. acknowledges funding from the Bill and Melinda Gates Foundation and the BBSRC (Grant Nos. INV-016631 and BB/V019791/1, respectively). This work was supported in part by the Fundacion Biofisica Bizkaia (FBB) and the Basque Excellence Research Centre (BERC) program of the Basque Government. J.A.N.-G. was supported by a FI predoctoral fellowship from the Basque Government and currently by FBB. Documen

    Association between vitamin D receptor rs731236 (Taq1) polymorphism and risk for restless legs syndrome in the Spanish caucasian population

    Get PDF
    Varios trabajos recientes sugieren un posible papel de la deficiencia de vitamina D en la etiología o el síndrome de las piernas inquietas (RLS). Hemos analizado la posible relación de 2 polimorfismos de un solo nucleótido (SNP) en el receptor de la vitamina D3 (GEN VDR) con el riesgo de SPI. Hemos estudiado la variante alélica genotipo y frecuencias de VDR rs2228570 y rs731236 VDR SNPs en 205 RLS pacientes y 445 controles sanos mediante un ensayo TaqMan. Las frecuencias de los rs731236AAgenotype y la variante alélica rs731236un SPI fue significativamente inferior en los pacientes que en los controles (P<0,005 y 0,01, respectivamente). El síndrome de las piernas inquietas pacientes portadoras de la variante alélica rs731236G había una edad temprana en el inicio, y los portadores del genotipo GG731236rs tuvieron mayor severidad de RLS, aunque estos datos desaparecieron después de los análisis multivariados. Ninguno de los SNPs estudiados estaba relacionada con la positividad de la historia familiar de SPI. Estos resultados sugieren una modesta, pero significativa asociación entre rs731236 VDR SNP y el riesgo de síndrome de piernas inquietas.Several recent works suggest a possible role of vitamin D deficiency in the etiology or restless legs syndrome (RLS). We analyzed the possible relationship of 2 common single nucleotide polymorphisms (SNPs) in the vitamin D3 receptor (VDR) gene with the risk for RLS. We studied the genotype and allelic variant frequencies of VDR rs2228570 and VDR rs731236 SNPs in 205 RLS patients and 445 healthy controls using a TaqMan essay. The frequencies of the rs731236AAgenotype and the allelic variant rs731236A were significantly lower in RLS patients than in controls (P<0.005 and<0.01, respectively). Restless legs syndrome patients carrying the allelic variant rs731236G had an earlier age at onset, and those carrying the rs731236GG genotype had higher severity of RLS, although these data disappeared after multivariate analyses. None of the SNPs studied was related with the positivity of family history of RLS. These results suggest a modest, but significant association between VDR rs731236 SNP and the risk for RLS.• Instituto de Salud Carlos III, Madrid, Fondo de Investigación Sanitaria: Ayudas PI12/00241, PI12/00324, y RETICS RD12/0013/0002 • Junta de Extremadura: GR15026 y PRIS10016 • Ministerio de Ciencia e Innovación: Ayudas SAF2006-10126 (2006–2009) y SAF2010-22329-C02-01 (2011-2013) • Parciamente financiado con Fondos FEDERpeerReviewe

    Heme oxygenase-1 and 2 common genetic variants and risk for restless legs syndrome

    Get PDF
    Varios neurotransmisores, neuropatológicos, neuroimagen, y los datos experimentales, sugieren que la deficiencia de hierro juega un papel importante en la fisiopatología del síndrome de piernas inquietas (RLS). HMOX (Hemeoxygenases) es un importante mecanismo de defensa contra el estrés oxidativo, principalmente a través de la degradación del hemo a biliverdin, libre de hierro, y monóxido de carbono. Hemos analizado si los genes HMOX1 y HMOX2 están relacionados con el riesgo de desarrollar el síndrome de piernas inquietas. Se analizó la distribución de genotipos y las frecuencias alélicas de los HMOX1 rs2071746, HMOX1 rs2071747, HMOX2 rs2270363 y rs1051308 HMOX2 SNPs, así como la presencia de variaciones de número de copia (CNVs) de estos genes en 205 sujetos RLS y 445 controles sanos. Las frecuencias de rs2071746 genotipo TT y R2071746T variante alélica fueron significativamente inferiores en los pacientes de SPI que en controles, aunque los otros 3 SNPs estudiados RLS no difirió entre pacientes y controles. Ninguno de los polimorfismos estudiados influyeron en el inicio de la enfermedad, la gravedad de la RLS, historia familiar de SPI, la ferritina sérica, o respuesta a agonistas dopaminérgicos, clonazepam o GABAergic drogas. El presente estudio sugiere una débil asociación entre el polimorfismo rs2071746 HMOX1 y el riesgo de desarrollar el SPI en la población española.Several neurochemical, neuropathological, neuroimaging, and experimental data, suggest that iron deficiency plays an important role in the pathophysiology of restless legs syndrome (RLS). Hemeoxygenases (HMOX) are an important defensive mechanism against oxidative stress, mainly through the degradation of heme to biliverdin, free iron, and carbon monoxide. We analyzed whether HMOX1 and HMOX2 genes are related with the risk to develop RLS. We analyzed the distribution of genotypes and allelic frequencies of the HMOX1 rs2071746, HMOX1 rs2071747, HMOX2 rs2270363, and HMOX2 rs1051308 SNPs, as well as the presence of Copy number variations (CNVs) of these genes in 205 subjects RLS and 445 healthy controls. The frequencies of rs2071746TT genotype and rs2071746T allelic variant were significantly lower in RLS patients than that in controls, although the other 3 studied SNPs did not differ between RLS patients and controls. None of the studied polymorphisms influenced the disease onset, severity of RLS, family history of RLS, serum ferritin levels, or response to dopaminergic agonist, clonazepam or GABAergic drugs. The present study suggests a weak association between HMOX1 rs2071746 polymorphism and the risk to develop RLS in the Spanish population.• Instituto de Salud Carlos III, Fondo de Investigación Sanitaria: Ayudas PI12/00241, PI12/00324 y RETICS RD12/0013/0002 • Junta de Extremadura: Ayuda GR10068 GR10068 y PRIS10016 (Fundesalud,Mérida, Spain) • Ministerio de Ciencia e Innovación: Ayudas SAF2006-10126 (2006–2009) y SAF2010-22329-C02-01 (2011–2013) • Parcialmente financiado Fondos FEDER – Fondo Europeo de Desarrollo RegionalpeerReviewe
    corecore