2,992 research outputs found

    The use of IRT to investigate the relationships between the g factor and cognitive tasks

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    Las relaciones entre el factor g y tareas de procesamiento de la información han abierto la puerta a la comprensión de la naturaleza de g ( Jensen, 1998). No obstante, es necesario superar determinados problemas metodológicos para poder comprender hasta qué punto las diferencias en g son ocasionadas por diferencias en procesos cognitivos. En este sentido, la falta de fiabilidad de las puntuaciones en las tareas de procesos puede llevar a conclusiones equivocadas sobre la naturaleza de dichas relaciones. Un medio de abordar este problema es seleccionar a las personas con un menor error de estimación del nivel de habilidad. Los resultados muestran un aumento de las correlaciones entre g y memoria de trabajo en el grupo de sujetos mejor medidos frente al grupo de personas con un error de estimación mayorMany authors have looked for the relations between the g factor and cognitive tasks in order to find out the nurture of the g factor (Jensen, 1998). Nevertheless, some methodological problems must be solved to understand if the individual differences in g are differences in cognitive processes. One of them is the low reliability of the scores in this kind of tasks. On the grounds of the standard error of the ability level estimation, we hypothesized that the correlations between the g factor and a working memory task would be larger in the g roup of the subjects better measured (less standard error). The results support this hypothesi

    Spanish version of the Coping Strategies Inventory

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    Introducción. En el presente trabajo acometimos la adaptación del Inventario de Estrategias de Afrontamiento (CSI) al ámbito español. Esta necesidad se justifica, por una parte, por la escasez y las limitaciones de los instrumentos disponibles en nuestro idioma, y por otra, por las excelentes potencialidades que ofrece el CSI. Método. Fue traducido y aplicado a una muestra de 337 personas adultas de características sociodemográficas diversas, recogida de forma incidental en actividades formativas en la provincia de Sevilla. Resultados. Los resultados mostraron unas excelentes propiedades psicométricas superando incluso las del estudio original: ocho factores explicaron un 61 % de la varianza con sólo 40 ítems (frente a los 72 que explicaban un 47% en el instrumento original) y obtuvieron coeficientes de consistencia interna entre 0,63 y 0,89. La validez convergente se comprobó utilizando las intercorrelaciones entre escalas y las correlaciones con disposiciones de personalidad (NEO-FFI) y eficacia percibida del afrontamiento. Conclusiones. El CSI se comportó de forma válida y fiable en la evaluación de la utilización de estrategias de afrontamiento en una amplia variedad de situaciones.Introduction. The aim of the present study was to adapt the Coping Strategies Inventory (CSI) to the Spanish setting. This need is justified on the one hand by the shortage and limitations of the instruments available in our language and, on the other, by the excellent potentialities that the CSI offers. Method. It was translated and applied to a sample of 337 adults, with diverse demographic characteristics, recruited from different teaching activities by the authors in the province of Seville (Spain). Results. The results showed excellent psychometric properties surpassing those of the original study: eight factors accounted for 61% of variance with only 40 items (as opposed to the 72 that accounted for 47% in the original study) and obtained Alpha coefficients between 0.63 and 0.89. The convergent validity was verified using intercorrelations between scales, correlations with personality dispositions (NEO-FFI) and with the coping efficacy. Discussion. The CSI was a valid and reliable measure of coping strategies used in many stressful situations

    Arcillas cerámicas de Andalucía. VI. Yacimientos terciarios y cuaternarios de la provincia de Huelva. comarcas de Huelva y El Condado

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    Se estudian veintiséis muestras de arcilla de interés cerámico, procedentes de diversos yacimientos en explotación situados en el Sur de la provincia de Huelva, en las comarcas de El Condado y zona costera. Los materiales proceden de sedimentos terciarios (la mayor parte) y cuaternarios, constituidos por margas de textura arcillo-arenosa o arcillo-limosa y se emplean en la fabricación de ladrillos y tejas en fábricas modernas de gran producción. Los materiales más plásticos se utilizan en alfarería y talleres de cerámica artística en Huelva y Trigueros. Las técnicas empleadas han sido las Siguientes: Análisis químico, capacidad de cambio, análisis térmico ponderal y diferencial, diagramas de difracción de rayos X, examen al microscopio electrónico, análisis mecánico, agua de moldeo, plasticidad (Riecke) , poroSidad, secado a 50ºC. (Diagramas de Bourry) , contracción por calcinación, peso específico y resistencia a la compresión en probetas calcinadas. Se desprende que estas arcillas son de naturaleza fundamentalmente montmorillonítica, con una elevada participación de minerales caoliníticos y micáceos (ilita y micas potásicas). Como minerales secundarios y accesorios contienen cuarzo, geles y feldespatos. Todas las muestras contienen cantidades medias hasta altas de calcita en grano fino, que en ciertos casos es de mayor tamaño y puede llegar a ser perjudicial sin un tratamiento conveniente. Las pruebas tecnológicas indican que se trata de materiales naturales de buenas propiedades cerámicas, de utilidad para la industria de materiales de construcción, y en otros casos para alfarería y cerámica artística. La gran potencia de los yacimientos, su fácil explotación y laboreo, su situación en terreno llano y de buenas comunicaciones y la constancia en la composición química y textura de la materia bruta, hace que los consideremos de interés industrial.Twenty Six samples of clay, interesting from the ceramic viewpoint, from several beds located in the South of the province of Huelva, in the country of El Condado and the coast have been studied. The great majority of materials belong to the Tertiary and Quaternary sediments and are formed by marls of sandy or silty clayed texture. They are used by large modern factories producing bricks and tiles. The more plastic materials are used by pottery and artistic ceramic industries in Huelva and Trigueros. The following techniques have been used: Chemical analysis, base exchange capacity, ponderal thermal analysis, D. T. A., X-ray difraction, electronic microscope, mechanical analysis, moulding water, plasticity (Riecke), porosity, drying shrinkage at 50°C. (Bourry's diagrams) firing shrinkage, specific gravity and crushing strength of fired bodies. It is concluded that these clays are fundamentally of montmorillonitic nature, with, a high proportion of kaolinitic and micaceous minerals (illite and potasic micas). They contain as secondary minerals, quartz gels and feldspars. All the samples contain medium to high quantities of fine grain ed calcite, which, in some casos, may be of larger size, being pernicious without previous treatment. The technological tests suggest that these materials are of good ceramic properties, useful in the building industry and in other cases, for pottery and artistic ceramics. The great depth of these beds, their easy explotation and working, their situation on flat and well communicated land and the constancy of chemical and textural composition of the raw materials make them of industrial interest

    On the optimaL response of q-vortex

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    Wingtip vortices represent a hazard for the stability of the following airplane in airport highways. These flows have been usually modeled as swirling jets/wakes, which are known to be highly unstable and susceptible to breakdown at high Reynolds numbers for certain flow conditions, but different to the ones present in real flying airplanes. A very recent study based on Direct Numerical Simulations (DNS) shows that a large variety of helical responses can be excited and amplified when a harmonic inlet forcing is imposed. In this work, the optimal response of q-vortex (both axial vorticity and axial velocity can be modeled by a Gaussian profile) is studied by considering the time-harmonically forced problem with a certain frequency ω. We first reproduce Guo and Sun’s results for the Lamb-Oseen vortex (no axial flow) to validate our numerical code. In the axisymmetric case m = 0, the system response is the largest when the input frequency is null. The axial flow has a weak influence in the response for any axial velocity intensity. We also consider helical perturbations |m| = 1. These perturbations are excited through a resonance mechanism at moderate and large wavelengths as it is shown in Figure 1. In addition, Figure 2 shows that the frequency at which the optimal gain is obtained is not a continuous function of the axial wavenumber k. At smaller wavelengths, large response is excited by steady forcing. Regarding the axial flow, the unstable response is the largest when the axial velocity intensity, 1/q, is near to zero. For perturbations with higher azimuthal wavenumbers |m| > 1, the magnitudes of the response are smaller than those for helical modes. In order to establish an alternative validation, DNS has been carried out by using a pseudospectral Fourier formulation finding a very good agreement.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Arcillas cerámicas de Andalucía V. Yacimientos de terrenos ígneos y sedimentos primarios de la provincia de Huelva. Comarcas de Sierra Morena y Andévalo

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    Twenty two samples of clays, interesting from the ceramic viewpoint, from several beds located on the northern and central regions of the province of Huelva, in the country of Sierra Morena and El Andévalo, respectively, have he en studied. The materials belong to outcrops of igneous nature and slate sediments from the Silurian and Carboniferous, and are of highly sandy texture in general. They are used to make bricks and tiles. The materials of higher clay content are used in pottery and artistic ceramic industries, specially those from Aracena and Cortegana. The following techniques have been used: chemical arialysis, base exchange capacity, ponderal thermal analysis D.T.A., X-ray diffraction, electron microscopy, mechanical analysis, moulding water, plasticity (Riecke), porosity, drying shrinkage at 50ºC. (Bourry's diagrams), firing shrinkage, specific gravity and crushing strength in fired bodies. It is concluded that the main components of the materials belonging to the igneous outcrops (granites, porphides, etc.), are fundamentally of kaolinitic nature, with a high proportion of micaceous minerals, free quartz as an accesory mineral and a variable amount of hydrated iron and aluminum oxides. Minerals of 14 A spacings are scarce. Samples from altered slate of Andévalo show distinctly a higher illite content followed by kaolinite and iron and aluminum gels. The presence of montmorillonitic minerals is more obvious. The technological tests suggest) that these raw materials have good ceramic properties, with a high iron content, appropriate for the uses mentioned above. The small extension of these beds prevent the use of these materials by the large ceramic industries.Se estudian veintidós muestras de arcilla de interés cerámico procedentes de diversos yacimientos situados en las regiones norte y centro de la provincia de Huelva, en las comarcas de Sierra Morena y El Andévalo, respectivamente. Los materiales proceden de afloramientos de naturaleza ígnea y sedimentos de pizarras del Silúrico y Carbonífero, de textura fuertemente arenosa en general, y se emplean en la fabricación de ladrillos y tejas. Los materiales más arcillosos se utilizan en alfarerías y talleres de cerámica artística, destacando los de Aracena y Cortegana. Las técnicas empleadas han sido las siguientes: Análisis químico, capacidad de cambio, análisis térmico ponderal y diferencial, diagramas de difracción de rayos X, examen al microscopio electrónico, análisis mecánico, agua de moldeo, plasticidad (Riecke), porosidad, secado a 50ºC (diagramas de Bourry), contracción por calcinación, peso específico y resistencia a la compresión en probetas calcinadas. Se deduce que los materiales procedentes de yacimientos sobre afloramientos ígneos (granito, pórfidos, etc.) son de naturaleza fundamentalmente caolinita, con una alta proporción de minerales micáceos, cuarzo libre como mineral accesorio y un contenido variable en óxidos de hierro y aluminio hidratados. Minerales con espaciados de 14 A apenas son apreciables. Las muestras procedentes de pizarras alteradas de El Andévalo destacan por su mayor contenido en Hita, seguida de caolinita y geles de hierro y aluminio. Se intensifica la presencia de minerales montmorilloníticos. Las pruebas tecnológicas indican que se trata de materiales naturales de buenas propiedades cerámicas, con alto contenido en hierro, aptos para los usos que hemos citado

    Motivación para el cambio como predictor de la adherencia terapéutica en el dolor crónico

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    Los tratamientos psicológicos que enfatizan la autogestión han resultado comúnmente apropiados como alternativas a la intervención médica en el dolor crónico. Desafortunadamente esta aproximación a menudo falla en comprometer a una porción significativa de individuos hacia los tratamientos y considerables índices de abandono y de recaída. El objetivo de este estudio fue comprobar la validez predictiva del modelo de estadíos de cambio en el dolor crónico a través del Pain States of Change Questionnaire (PSOCQ) sobre la adherencia y los resultados terapéuticos. La muestra se compuso de 48 pacientes de dolor crónico, concretamente con trastorno de fibromialgia, reclutados en una unidad de dolor de un hospital público de Sevilla. La mitad de ellos siguió una intervención cognitivo-conductual, y la otra mitad un programa de autogestión guiado por pacientes entrenados. Los resultados avalan la capacidad predictiva del PSOCQ, en tanto en cuanto: a) se constató una probabilidad estadísticamente significativa de no completar el tratamiento cuanto menor fue la motivación para el cambio; b) la motivación para el cambio de los pacientes que completaron el tratamiento se incrementó de forma estadísticamente significativa; y, c) una menor motivación para el cambio tras el tratamiento se asoció a una mayor gravedad del trastorno. La discusión se centra en el interés de manejar la motivación para el cambio para mejorar la eficiencia terapéutica.Psychological treatments that emphasize the auto-management have turned out to be commonly adapted like alternative to the medical intervention in the chronic pain. Unfortunately this approximation often fails in compromising to a significant portion of individuals towards treatments and many abandons and relapses. The aim of this study was to verify the predictive validity of States of Change Model in chronic pain using the Pain States of Change Questionnaire (PSOCQ) to predict adherence and therapeutic results. The sampled consisted of 48 patients of chronic pains-fibromyalgia recruited in a public pain clinic of Seville (Spain). The half of them followed a cognitive-behavioral intervention, and another half a program of auto-management guided by expert patients. The results support the predictive validity of the PSOCQ, while in all that: a) patient with less change motivation had less probability of completing the treatment; b) change motivation increased as effect of the treatment; and c) a less change motivation was associated to more gravity of the disorder. The discussion centers of the interest of considering change motivation to improve therapeutic efficiency.Consejería de Salud de la Junta de Andalucí

    Attribution of risk factors for suicide in children and adolescents in the Latino immigrant community: a sample of Southern California

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    In the last years an alarming increase has taken place in the number of suicides in children and teenagers, being a daily reality in the panorama of the USA, especially in the case of Latino immigrants. In the current study, a survey about the perceived risk factors for suicide was established between risk population. The sample was composed of 593 children and adolescents aged between 11 and 18 years, most Latino ethnicity, belonging to "Latina Youth Program" (LYP), a program of suicide prevention in risk population, developed by Pacifics Clinics, an organization that operates in Los Angeles, California. They interviewed the participants about the factors they considered risk for suicidal behavior. Participants were randomly selected in 2003, 2005 and 2008. The factors most commonly identified risk were the regulation of emotions (96.57%), poor family communication, poor school performance, the influence of the peer group (89.67%, 82. 73% and 41.57% respectively). The found trend is towards an increase in the perception of risk factors detected in any case up to ten risk factors for suicide. The higher quantity of variables impede the precise determination of the (s) reason (s) that might end in this fatidical conclusion, being the most common a panorama in which converge multitude of variables, crucial to settling objectives in interventionsEn los últimos años se ha producido un incremento alarmante en el número de suicidios en niños y adolescentes, siendo una realidad cotidiana en el panorama de los EEUU, especialmente en el caso de inmigrantes latinos. En el presente estudio, se estableció un sondeo en población de riesgo acerca de los factores de riesgo de suicidio percibidos. La muestra quedó conformada por 593 niños y adolescentes de edades comprendidas entre los 11 y los 18 años, la mayoría de etnia latina, pertenecientes a “Latina Youth Program” (LYP), un programa de prevención del suicidio en población de riesgo, desarrollado por Pacifics Clinics, una organización que desarrolla su actividad en Los Ángeles, California. Se entrevistó a los participantes acerca de los factores que ellos consideraban de riesgo para la conducta suicida. Los participantes fueron seleccionados aleatoriamente en los años 2003, 2005 y 2008. Los factores de riesgo más comúnmente señalados fueron la regulación de emociones (96.57%), la pobre comunicación familiar, bajo rendimiento escolar, la influencia del grupo de iguales (89.67%, 82. 73% y 41.57% respectivamente). La tendencia encontrada apunta hacia un aumento en la percepción de factores de riesgo, detectándose en cualquier caso hasta diez factores de riesgo de suicidio. La cantidad de variables puestas en juego complejizan la determinación precisa de la(s) causa(s) que podrían desembocar en este fatídico desenlace, siendo lo más común un panorama en el que confluyen multitud de variables, cruciales para asentar objetivos en las intervencione

    Exploratory and confirmatory factorial structure of the MCMI-III personality disorders: overlapping versus non-overlapping scales

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    Background and Objectives: The aim of this study was to explore the factorial structure of the 14 Personality Disorder (PD’s) scales of the MCMI-III for the overlapping and non-overlapping scales, independently. Previous exploratory studies using different factor extraction procedures inform that the structure of MCMI-III personality disorders has between 2 and 4 factors. Methods: The present study used a large sample of 674 non-clinical subjects divided at random in two groups: a) calibration, and b) validation. In the calibration group, principal component analysis with orthogonal rotation was carried out, obtaining 2, 3 and 4 factors for the overlapping and non-overlapping scales independently. In the validation group, the three models were compared using confirmatory factorial analysis techniques. Results and Conclusions: The exploratory and confirmatory results indicate that the 4-factor solution is the most plausible. Although the congruence coefficients between non-overlapping and overlapping scales in the 4-factor solution were higher, confirmatory factor analysis showed that models designed from overlapping scales did not fit well to data

    Associations between sedentary time, physical activity and bone health among older people using compositional data analysis

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    Introduction : Aging is associated with a progressive decrease in bone mass (BM), and being physical active is one of the main strategies to combat this continuous loss. Nonetheless, because daily time is limited, time spent on each movement behavior is co-dependent. The aim of this study was to determine the relationship between BM and movement behaviors in elderly people using compositional data analysis. Methods : We analyzed 871 older people [395 men (76.9 +/- 5.3y) and 476 women (76.7 +/- 4.7y)]. Time spent in sedentary behavior (SB), light physical activity (LPA) and moderate-to-vigorous physical activity (MVPA), was assessed using accelerometry. BM was determined by bone densitometry (DXA). The sample was divided according to sex and bone health indicators. Results : The combined effect of all movement behaviors (PA and SB) was significantly associated with whole body, leg and femoral region BM in the whole sample (p<0.05), with leg and pelvic BM (p<0.05) in men and, with whole body, arm and leg BM (p<0.05) in women. In men, arm and pelvic BM were negatively associated with SB and whole body, pelvic and leg BM were positively associated with MVPA (p<0.05). In women, whole body and leg BM were positively associated with SB. Arm and whole body BM were positively associated and leg BM was negatively associated with LPA and arm BM was negatively associated with MVPA (p<0.05). Women without bone fractures spent less time in SB and more in LPA and MVPA than the subgroup with bone fractures. Conclusion : We identified that the positive effect of MVPA relative to the other behaviors on bone mass is the strongest overall effect in men. Furthermore, women might decrease bone fracture risk through PA increase and SB reduction, despite the fact that no clear benefits of PA for bone mass were found
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