670 research outputs found

    Learn-ciam: a model-driven approach for the development of collaborative learning tools

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    This paper introduces Learn-CIAM, a new model-based methodological approach for the design of flows and for the semi-automatic generation of tools in order to support collaborative learning tasks. The main objective of this work is to help professors by establishing a series of steps for the specification of their learning courses and the obtaining of collaborative tools to support certain learning activities (in particular, for in-group editing, searching and modeling). This paper presents a complete methodological framework, how it is supported conceptually and technologically, and an application example. So to guarantee the validity of the proposal, we also present some validation processes with potential designers and users from different profiles such as Education and Computer Science. The results seem to demonstrate a positive reception and acceptance, concluding that its application would facilitate the design of learning courses and the generation of collaborative learning tools for professionals of both profiles

    Hábitos de sueño y problemas relacionados con el sueño en adolescentes: relación con el rendimiento escolar

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    ObjetivoConocer la prevalencia de trastornos de sueño en los adolescentes. Describir los hábitos de sueño de los adolescentes y su relación con los trastornos del sueño y los factores asociados. Conocer la relación entre los trastornos del sueño y/o los hábitos de sueño inadecuados con el rendimiento escolar.DiseñoEstudio observacional, descriptivo y transversal.EmplazamientoInstitutos de enseñanza secundaria obligatoria (ESO) de la ciudad de Cuenca.ParticipantesUn total de 1.293 alumnos escolarizados en primero y cuarto cursos de ESO.Mediciones principalesHábitos de sueño en días lectivos y fines de semana y prevalencia de trastornos del sueño medidos mediante un cuestionario estructurado con preguntas abiertas y cerradas, autoadministrado y anónimo. Se determinó el rendimiento escolar de los alumnos y su relación con los hábitos y trastornos de sueño.ResultadosDe los 1.293 alumnos matriculados, completaron la encuesta 1.155 (89,33%), 537 (45,9%) chicos y 618 (54,1%) chicas, con una media de edad de 14 años (rango, 11-18 años). Los días laborables se acuestan en promedio a las 23.17 y se levantan a las 7.46 (tiempo medio, 8 h y 18 min) y los fines de semana se acuestan a la 1.02 y se levantan a las 10.42 (tiempo medio, 9 h y 40 min). El 45,4% declara dormir mal la noche del domingo al lunes. El promedio de asignaturas suspendidas es mayor en los adolescentes con queja de sueño (2,28 frente a 1,91; p = 0,04), los que se levantan cansados (2,17 frente a 1,97; p = 0,048) y los que tienen somnolencia diurnal (2,17 frente a 1,75; p = 0,004).ConclusionesEl horario escolar conlleva deuda de sueño durante la semana que se recupera parcialmente el fin de semana. En los fines de semana se produce una rotura en los hábitos de sueño de los adolescentes. Los adolescentes con problemas relacionados con el sueño muestran peor rendimiento escolar.ObjectiveTo determine the prevalence of sleep disorders in adolescence.To describe sleeping habits of adolescents in relation to sleep disorders and associated factors. To determine the relation between sleep disorders/inappropiate sleeping habits and school performance.DesignObservational, descriptive, crosssectional study.SettingSecondary school of Cuenca (city in Spain).Participants1293 school children of first and fourth curses of secondary education.Main measuresStructured questionnaire with opened and closed questions on sleeping habits during weekdays and at weekends and sleep disorders to be answered by the adolescents anonymously and on their own. Student's school performance with relation with to sleeping habits and sleep disorders were determined.Results1155 students out of 1293 (response rate 89.33%) answered the questionnaire, 537 (45.9%) boys and 618 (54.1%) girls, 14 years old on average (between 11-18 years). On weekdays students went to bed at 23.17 h and got up at 7.46 h (average sleeping time =8 hours and 18 minutes). At weekends they went to bed at 1.02 h and got up at 10.42 h (average sleeping time =9 hours and 40 minutes). 45.4% of students said to sleep badly on Sunday night's.On average the number of subjects failed in class is higher with adolescents who complain about sleep (2.28 vs 1.91; P=.04), who are tired at waking up time (2.17 vs 1.97; P=.048) and who have morning sleepiness (2.17 vs 1.75; P=.004).ConclusionsSchools hours cause deficitsleeping time during weekdays which is partly made up for at weekend. At weekends there is an interruption of the adolescent's sleeping habits. School performance of adolescents with sleep disorders is lower

    Existem diferenças nas emoções percebidas pelos alunos do ensino médio de acordo com o sexo e o ano letivo nas sessões de expressão corporal?

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    Resumen: Introducción: Las emociones percibidas por los alumnos durante las sesiones de expresión corporal son determinantes para conseguir una mayor satisfacción y motivación durante la práctica. Por tanto, es importante analizar la influencia de la lógica interna en las actividades de expresión en los alumnos participantes. Objetivos: El objetivo de esta investigación fue analizar la influencia del sexo y el curso escolar en las emociones percibidas durante la realización de actividades de expresión corporal como situación motriz de expresión. Método: La muestra estuvo compuesta por 80 alumnos pertenecientes a un centro público de educación secundaria que participaron voluntariamente en esta investigación (sexo: chicos n=49, chicas n=31; curso académico: 1ª n=28, 2A n=30, 2B n=22). Se diseñaron 5 actividades, las cuales se realizaron en dos sesiones en semanas diferentes. Para analizar las emociones percibidas se les suministró la Escala Juegos Deportivos y Emociones (GES) modificada. Resultados y discusión: Se encuentran diferencias en las emociones rabia y tristeza en función del sexo siendo estas mayores en los hombres (p<.05) y en las emociones rabia, tristeza, miedo y vergüenza en función del curso escolar, reportando mayores valores en el curso donde los alumnos tenían menor edad (p<.05). Conclusiones: En conclusión, el sexo y la edad son dos factores a tener en cuenta en el diseño de las sesiones de expresión corporal debido a su influencia en las emociones percibidas por los alumnos.Abstract: Introduction: The emotions perceived by the students during the sessions of body expression are determinant to achieve a greater satisfaction and motivation in the practice. Therefore, it is important to analyse the internal logic influence in the emotions perceived by the participants in body expression sessions. Aim: The aim of this research was to analyse the sex and academic year influence on the emotions perceived during the performance of body expression activities as motor situation of expression. Methods: 80 public high-school students participated voluntarily in this research (sex: boys n=49, girls n=31, academic course: 1A n=28, 2A n=30, 2B n=22). Five activities were designed, which were performed in two sessions in different weeks. To analyze the perceived emotions, the modified Sports Games and Emotions (GES) Scale was used. Results & discussion: Differences are found in emotions according to sex and age. Rage and sadness were higher in men (p<.05), while, anger, sadness, fear and shame were higher in the youngest teenagers (p<.05). Conclusions: In conclusion, sex and age are two factors to take into account in the design of body expression sessions due to their influence on the emotions perceived by the students.Resumo: Introdução: As emoções percebidas pelos alunos durante as sessões de expressão corporal são determinantes para alcançar uma maior satisfação e motivação durante a prática. Portanto, é importante analisar a influência da lógica interna nas atividades de expressão dos alunos participantes. Objetivos: O objetivo desta pesquisa foi analisar a influência do sexo e do ano escolar sobre as emoções percebidas durante a realização de atividades de expressão corporal como situação motora de expressão. Método: A amostra foi constituída por 80 estudantes pertencentes a uma escola pública de ensino médio que participaram voluntariamente da pesquisa (sexo: meninos n=49, meninas n=31, ano acadêmico: 1A n=28, 2A n=30, 2B n=22). Cinco atividades foram planejadas, que foram realizadas em duas sessões em diferentes semanas. Para analisar as emoções percebidas, foi fornecida a escala modificada Sports Games and Emotions (GES). Resultados e discussão: Diferenças são encontradas nas emoções de raiva e tristeza dependendo do sexo, sendo mais velhas nos homens (p<.05) e nas emoções raiva, tristeza, medo e vergonha, dependendo do ano letivo, relatando valores mais elevados em o curso onde os alunos eram mais jovens (p<.05). Conclusões: Conclui-se que o sexo e a idade são dois fatores a considerar no desenho das sessões de expressão corporal, devido a sua influência nas emoções percebidas pelos estudantes

    Features of dengue and chikungunya infections of colombian children under 24 months of age admitted to the emergency department

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    We aimed to assess clinical and laboratory differences between dengue and chikungunya in children <24 months of age in a comparative study. We collected retrospective clinical and laboratory data confirmed by NS1/IgM for dengue for 19 months (1 January 2013 to 17 August 2014). Prospective data for chikungunya confirmed by real-time polymerase chain reaction were collected for 4 months (22 September 2014-14 December 2014). Sensitivity and specificity [with 95% confidence interval (CI)] were reported for each disease diagnosis. A platelet count <150 000 cells/ml at emergency admission best characterized dengue, with a sensitivity of 67% (95% CI, 53-79) and specificity of 95% (95% CI, 82-99). The algorithm developed with classification and regression tree analysis showed a sensitivity of 93% (95% CI, 68-100) and specificity of 38% (95% CI, 9-76) to diagnose dengue. Our study provides potential differential characteristics between chikungunya and dengue in young children, especially low platelet counts. © The Author [2017].Universidad Nacional de Colombia, UN Johns Hopkins University1Departamento de Epidemiologia, Hospital Infantil Napoleón Franco Pareja—La Casa del Niño, Cartagena, Colombia 2Facultad de Medicina, Universidad Nacional de Colombia, Bogotá, Colombia 3Departamento de Epidemiologia, Faculdade de Saúde Publica, Universidade de São Paulo, São Paulo, Brazil 4Facultad de Ingenería, Universidad Tecnológica de Bolívar, Cartagena, Colombia 5Facultad Ciencias Básicas y Biomédicas, Universidad Simón Bolívar, Barranquilla, Colombia 6Facultad de Medicina, Universidad de Cartagena, Cartagena, Colombia 7Instituto de Investigaciones Biologicas del Tropico, Universidad de Córdoba, Montería, Colombia 8Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA Correspondence: Angel Paternina-Caicedo, Hospital Infantil Napoleón Franco Pareja—La Casa del Niño, Bruselas Transversal 36 N. 36-33, Cartagena, Bolívar, Colombia. Tel: +1-412-3267809. E-mail or

    High-voltage pulse generator based on sequentially charged MMC-SMs operating in a voltage-boost mode

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    Pulse forming networks and Marx generators are the classical rectangular waveform pulse generators (PGs). They are inflexible and their capacitors must be fully charged to the required voltage from 0V before delivering each high-voltage (HV) pulse. They are only able to generate unipolar pulses; if bipolar pulses are sought another generator fed from a negative supply voltage is added. Recently, several power electronics based PGs have been proposed. This paper presents an HV power electronics based PG, which is based on Half-Bridge Modular Multilevel Converter (HB-MMC) sub-modules (SMs) charged sequentially in a voltage boost mode. Each SM capacitor and main switch form a boost converter with the charging input supply and inductor. As a result, all SM capacitors are charged to a voltage greater than the input. During the discharging process the SM capacitors are connected in series, producing a rectangular HV pulse across the load. The proposed charging method allows a reduction in the converter footprint in comparison with recently proposed MMC sequentially charged PG topologies. Although only rectangular pulse waveforms are sought in this paper, a SM capacitor voltage balance method allows multilevel pulse generation. The viability of the proposed converter is confirmed by MATLAB/Simulink simulation and scaled-down experimentation

    Design and evaluation of a treatment programme for Spanish adolescents with overweight and obesity. The EVASYON Study

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    Background The prevalence of overweight and obesity (OW/OB) among adolescents worldwide has increased since the 60 s. Spain has reached one of the highest OW/OB prevalence rates among adolescents from European countries. The aim of this methodological paper is to describe the design and evaluation in the EVASYON study (Development, implementation and evaluation of the efficacy of a therapeutic programme for adolescents with OW/OB: integral education on nutrition and physical activity). Methods/Design The EVASYON was planned by a multidisciplinary team to treat OW/OB in Spanish adolescents. The EVASYON is a multi-centre study conducted in 5 hospitals in 5 Spanish cities (Granada, Madrid, Pamplona, Santander and Zaragoza) and two hundred and four OW/OB Spanish adolescents were recruited for this intervention. The treatment was implemented for approximately one-year follow-up. The adolescents were treated in groups of a maximum of 10 subjects; each group had 20 visits during the treatment period in two phases: intensive during the first 2 months (1st to 9th visits), and extensive during the last 11 months (10th to 20th visits). In order to assess the efficacy of the treatment, 8 dimensions were measured: diet; physical activity and fitness; eating behaviour; body composition; haematological profile; metabolic profile; minerals and vitamins; immuno-inflammatory markers. Moreover, genetic polymorphisms were also determined. Discussion The treatment programme developed in the EVASYON study was designed as a national pilot study to be implemented as an effective treatment for adolescents with OW/OB into the Spanish Health Care Service

    Atmospheric effects on extensive air showers observed with the Surface Detector of the Pierre Auger Observatory

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    Atmospheric parameters, such as pressure (P), temperature (T) and density, affect the development of extensive air showers initiated by energetic cosmic rays. We have studied the impact of atmospheric variations on extensive air showers by means of the surface detector of the Pierre Auger Observatory. The rate of events shows a ~10% seasonal modulation and ~2% diurnal one. We find that the observed behaviour is explained by a model including the effects associated with the variations of pressure and density. The former affects the longitudinal development of air showers while the latter influences the Moliere radius and hence the lateral distribution of the shower particles. The model is validated with full simulations of extensive air showers using atmospheric profiles measured at the site of the Pierre Auger Observatory.Comment: 24 pages, 9 figures, accepted for publication in Astroparticle Physic

    Update on the correlation of the highest energy cosmic rays with nearby extragalactic matter

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    Data collected by the Pierre Auger Observatory through 31 August 2007 showed evidence for anisotropy in the arrival directions of cosmic rays above the Greisen-Zatsepin-Kuz'min energy threshold, \nobreak{6×10196\times 10^{19}eV}. The anisotropy was measured by the fraction of arrival directions that are less than 3.13.1^\circ from the position of an active galactic nucleus within 75 Mpc (using the V\'eron-Cetty and V\'eron 12th12^{\rm th} catalog). An updated measurement of this fraction is reported here using the arrival directions of cosmic rays recorded above the same energy threshold through 31 December 2009. The number of arrival directions has increased from 27 to 69, allowing a more precise measurement. The correlating fraction is (386+7)(38^{+7}_{-6})%, compared with 2121% expected for isotropic cosmic rays. This is down from the early estimate of (6913+11)(69^{+11}_{-13})%. The enlarged set of arrival directions is examined also in relation to other populations of nearby extragalactic objects: galaxies in the 2 Microns All Sky Survey and active galactic nuclei detected in hard X-rays by the Swift Burst Alert Telescope. A celestial region around the position of the radiogalaxy Cen A has the largest excess of arrival directions relative to isotropic expectations. The 2-point autocorrelation function is shown for the enlarged set of arrival directions and compared to the isotropic expectation.Comment: Accepted for publication in Astroparticle Physics on 31 August 201

    The Fluorescence Detector of the Pierre Auger Observatory

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    The Pierre Auger Observatory is a hybrid detector for ultra-high energy cosmic rays. It combines a surface array to measure secondary particles at ground level together with a fluorescence detector to measure the development of air showers in the atmosphere above the array. The fluorescence detector comprises 24 large telescopes specialized for measuring the nitrogen fluorescence caused by charged particles of cosmic ray air showers. In this paper we describe the components of the fluorescence detector including its optical system, the design of the camera, the electronics, and the systems for relative and absolute calibration. We also discuss the operation and the monitoring of the detector. Finally, we evaluate the detector performance and precision of shower reconstructions.Comment: 53 pages. Submitted to Nuclear Instruments and Methods in Physics Research Section
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