84 research outputs found
Recursos litosféricos y medio ambiente
This paper focuses that geological resources is an essential need in development of the society and specially of the developing countries. Taking into account the processes and environmental problems related to mining exploitation, these activities should be performed in environment concordance. For these reason all the available environ-mental techniques and tools for a responsible exploitation of resources should be used
Is profitable to play in Spanish Soccer First Division?
El artículo presenta la primera fase de un estudio del fútbol español, cuyo objetivo es averiguar si es rentable jugar en Primera División de fútbol (1ª) para cualquier equipo profesional y si todos los clubes de 2ªA deberían aspirar al ascenso. Se comparan resultados en la población seleccionada y en dos grupos de la misma: equipos que se han mantenido en 1ª y equipos ascensor. Se examinan mediante análisis exploratorio de datos resultados económicos y deportivos, se identifican factores que influyen en su variación y se clasifican los clubes según dichos factores. También se determina la influencia de ascensos y descensos en los resultados. Se deduce que los equipos ascensor obtienen peores resultados aun jugando en la misma liga. Además, a su estabilidad económico financiera le afecta más el ascenso y descenso continuo que el mantenerse en una categoría concreta. Finalmente, que la “gestión del miedo” no siempre conduce a una mejor clasificación y añade tensión financiera. Se concluye que no a todos los clubes les conviene militar en 1ª división de fútbol, que ésta debe reestructurarse y se debe reforzar la 2ªAThe paper presents the first phase of a Spanish football study. The aim is to determine if it is profitable to play in 1ª D league for any professional team and if all clubs in 2ª A division should aspire to climb. Various results are compared in the selected population and also in two groups identified: equipment that have remained in 1ªD and “elevator teams”. The economics and sports results are examined by exploratory data analysis. We identify factors that are influence in change and the teams are classified according to these factors. Finally the influence of promotion and relegation in these results is determined. It follows that the "Fear Management" doesn’t always lead to better classification and adds financial stress, “elevator equipment” that perform worse even playing in the same league and its economic and financial stability will most affect the rise and decline that continued the stay in a particular category. We conclude: not all clubs suit them military in 1ª, it would be to restructure and strengthen the 2ª
Electrokinetic Behaviour and Interaction with Oxalic Acid of Different Hydrous Chromium(III) Oxides
Three samples of hydrous chromium(III) oxide have been prepared by different procedures, and their electrokinetic mobilities have been measured. In mineral media, isoelectric points were found to be 8.45 ±0.15. This value is shifted from the solution isoelectric point by –0.35 ±0.15, due to the contribution of solvation energy to the energy of ionic adsorption. On the basis of a simple model, it is suggested that the two successive surface acidity constants of hydrous chromium(III) oxide are pKS a1 = 7.17 and pKS a2 = 9.72. The influence of oxalic acidity on mobility may be described in terms of two successive adsorption equilibria, the first one conducive to the neutralization of positive protonic charge, and the second one originating a charge reversal. It is shown that the apparent affinity for this latter mode is lower in one of the samples, suggesting that surface complexation constants may in fact be sensitive to the history of hydrous chromium(III) oxide particles. The three samples show similar dissolution behaviour but the specific rates differ, in one case by two orders of magnitude. This difference is explained in terms of the influence of crosslinking on the reactivity
Evaluación del bullying como victimización: Estructura, fiabilidad y validez del Cuestionario de Acoso entre Iguales (CAI)
The aim of the present study was to provide preliminary evidence concerning validation of the Cuestionario de Acoso entre Iguales (CAI) [Peer Bullying Questionnaire] (Magaz, Chorot, Sandín, Santed, & Valiente, 2011). We examined the factor structure, reliability and convergent and discriminant validity of the Conductas de Acoso (CAI-CA) scale [Bullying Behaviors] in a sample of school-aged children and adolescents. Exploratory and confirmatory factor analyses provided support for a structure of seven uncorrelated factors which correspond to the following kinds of bullying: physical aggression, verbal aggression, direct social exclusion, indirect social exclusion, threats, cyberbullying, and aggression based on physical objects. Results provide support for factorial validity, internal consistency, and convergent and discriminant validity of the questionnaire. Data suggest that the CAI-CA is an appropriate assessment instrument of bullying victimization that may be a suitable tool for research and clinical purposes.El objetivo del presente estudio consistió en validar el Cuestionario de Acoso entre Iguales (CAI) (Magaz, Chorot, Sandín, Santed, y Valiente, 2011). Examinamos la estructura factorial, la fiabilidad y la validez convergente y discriminante de la escala de Conductas de Acoso (CAI-CA) en una muestra de niños y adolescentes. Los análisis factoriales exploratorios y confirmatorios constataron una estructura de siete factores no correlacionados que se corresponden con los siguientes tipos de bullying: maltrato físico, maltrato verbal, exclusión social directa, exclusión social indirecta, amenazas, ciberbullying, y agresión basada en objetos. Los resultados apoyan la validez factorial, la consistencia interna, y la validez convergente y discriminante del cuestionario. Los datos sugieren que el CAI-CA puede ser una herramienta apropiada para evaluar el bullying de victimización tanto en contextos de investigación como clínicos
Estilos de apego y acoso entre iguales (bullying) en adolescentes
The aim of this work is twofold, (a) to validate the Spanish version of the Adolescent Relationship Scales Questionnaire (ARSQ) and (b) to examine associations between attachment and peer bullying (victimization). A total of 600 adolescents (aged 13-16 years) completed the ARSQ and the CAI-CA (a Spanish questionnaire of bullying victimization). Exploratory factor analyses of the ARSQ yield a structure of three uncorrelated factors which appear to correspond to the secure, fearful/preoccupied and dismissing kinds of attachment, respectively. Girls scored higher than boys on secure and fearful/preoccupied attachment. Thirty-four percent of the sample reported to have been victim of peer bullying. A hierarchical logistic regression analysis indicated that, after controlling for age and gender, fearful/preoccupied attachment significantly predicted the risk of being a victim of bullying. Results are discussed in respect of possible implications for the primary prevention of bullying.El objetivo del presente trabajo es doble: (a) validar la versión española del Adolescent Relationship Scales Questionnaire (ARSQ), y (b) examinar la asociación entre el apego y el acoso entre iguales (victimización). Un total de 600 adolescentes (entre 13 y 16 años de edad) cumplimentó el ARSQ y el CAI-CA (Cuestionario de Acoso entre Iguales—Conductas de Acoso). A través de análisis factoriales exploratorios del ARSQ obtuvimos una estructura de tres factores no correlacionados, los cuales correspondían a las formas de apego seguro, miedoso/preocupado y evitativo, respectivamente. Las chicas puntuaron más alto que los chicos en apego seguro y miedoso/ preocupado. El 34% de la muestra informó haber sido víctima de acoso entre iguales. El análisis de regresión logística jerárquica indicó que, tras controlar el efecto de la edad y el género, el apego miedoso/preocupado predecía el riesgo de ser víctima de acoso por los compañeros. Se discuten los resultados en relación con posibles implicaciones sobre la prevención primaria del bullying.
Young deceased donor kidneys show a survival benefit over older donor kidneys in transplant recipients aged 20-50 years:a study by the ERA-EDTA Registry
Background: Updated survival outcomes of young recipients receiving young or old deceased donor kidneys are required when considering accepting a deceased donor kidney. Methods: We examined outcomes in 6448 European kidney allografts donated from younger (≥20-<50 years) and older (≥50-<70 years) deceased donors when transplanted into very young (≥20-<35 years) or young (≥35-<50 years) adult recipients. Outcomes of first kidney transplantations during 2000-13 and followed-up to 2015 were determined via competing risk, restricted mean survival and Cox regression methods. Results: The 10-year cumulative incidence of graft failure was lowest in very young {22.0% [95% confidence interval (95% CI) 19.1-24.9]} and young [15.3% (95% CI 13.7-16.9)] recipients of younger donor kidneys and highest in very young [36.7% (95% CI 31.9-41.5)] and young [29.2% (95% CI 25.1-33.2)] recipients of older donor kidneys. At the 10-year follow-up, younger donor kidneys had a 1 year (very young) or 9 months (young) longer mean graft survival time compared with older donor kidneys. Graft failure risk in younger donor kidneys was 45% [very young adjusted hazard ratio (aHR) 0.55 (95% CI 0.44-0.68)] and 40% [young aHR 0.60 (95% CI 0.53-0.67)] lower compared with older donor kidneys. A 1-year increase in donor age resulted in a 2% [very young aHR 1.02 (95% CI 1.00-1.04)] or 1% [young aHR 1.01 (95% CI 1.00-1.01)] increase in the 10-year risk of death. Conclusions: Younger donor kidneys show survival benefits over older donor kidneys in adult recipients ages 20-50 years. Updated survival outcomes from older deceased donors are necessary due to advances in transplantation medicine and the increasing role these donors play in organ transplantation
Stiffness memory of indirectly 3D-printed elastomer nanohybrid regulates, chondrogenesis and osteogenesis of human mesenchymal stem cells
The cellular microenvironment is dynamic, remodeling tissues lifelong. The biomechanical properties of the extracellular matrix (ECM) influence the function and differentiation of stem cells. While conventional artificial matrices or scaffolds for tissue engineering are primarily static models presenting well-defined stiffness, they lack the responsive changes required in dynamic physiological settings. Engineering scaffolds with varying elastic moduli is possible, but often lead to stiffening and chemical crosslinking of molecular structure with limited control over scaffold architecture. A family of indirectly 3D printed elastomeric nanohybrid scaffolds with thermoresponsive mechanical properties that soften by inverse self-assembling at body temperature have been developed recently. The initial stiffness and subsequent stiffness relaxation of the scaffolds regulated the proliferation and differentiation of human bone-marrow derived mesenchymal stem cells (hBM-MSCs) towards the chondrogenic and osteogenic lineages over 4 weeks, as measured by immunohistochemistry, histology, ELISA and qPCR. hBM-MSCs showed enhanced chondrogenic differentiation on softer scaffolds and osteogenic differentiation on stiffer ones, with similar relative expression to that of human femoral head tissue. Overall, stiffness relaxation favored osteogenic activity over chondrogenesis in vitro
Development data associated with effects of stiffness softening of 3D-TIPS elastomer nanohybrid scaffolds on tissue ingrowth, vascularization and inflammation in vivo
This DiB article contains data related to the research article entitled “Cellular responses to thermoresponsive stiffness memory elastomer nanohybrid scaffolds by 3D-TIPS” [1]. Thermoresponsive poly (urea-urethane) nanohybrid elastomer (PUU-POSS) scaffolds were implanted in rats for up to 3 months. The porous structure and tensile mechanical properties of the scaffolds are listed and compared before and after in vitro and in vivo tests. The details of histological analysis of the explants with different initial stiffness and porous structures at various time points are presented. The images and data presented support the conclusion about the coupled effects of stiffness softening and the hierarchical porous structure modulating tissue ingrowth, vascularization and macrophage polarization the article [1]
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