562 research outputs found
Design and validation of a socio-emotional questionnaire for youth football players
Con el objetivo de detectar y controlar los factores socio-emocionales que influyen en la progresión del joven futbolista, se diseñó un cuestionario auto-cumplimentado de 40 ítems, agrupados en 3 dimensiones (entorno social, bienestar e inteligencia emocional). Se analizó la validez de contenido mediante la valoración de 14 expertos y la validez de constructo mediante análisis factorial. Se evaluó la fiabilidad del cuestionario, administrándolo a jóvenes futbolistas de élite (n=281) y analizando la consistencia interna por el método del Alfa de Cronbach y la fiabilidad test-retest mediante el coeficiente de correlación intraclase (CCI). El análisis factorial confirmó la existencia de 18 categorías, que en conjunto explican el 65,40% de la varianza total. El Alfa de Cronbach del cuestionario fue de 0,944 (p<0,01) y el CCI de 0,894 (p<0,01). El cuestionario reúne suficientes propiedades psicométricas como para ser considerado una herramienta válida y fiable para medir el entorno socio-emocional de jóvenes futbolistas.The objective of this study was to design a valid questionnaire to detect and manage the socio-emotional factors that influence the performance of young football players. A group of specialists designed a self-completion questionnaire of 40 items grouped into 3 dimensions. Content validity was analysed and evaluated by 14 experts and construct validity was analysed by factorial analysis. To evaluate reliability the questionnaire was administered to young elite football players, and internal consistency was analysed with Cronbach’s alpha. Test-retest reliability was assessed with the intraclass correlation coefficient (ICC). Factor analysis confirmed the existence of 18 factors, which as a whole explained 65.40% of the total variance. The Cronbach’s alpha of the questionnaire was 0.944 (p<0.01) and the ICC of the entire questionnaire was 0.894 (p<0.01). The questionnaire gathers together enough psychometric properties to be considered a valid and reliable tool for gauging the socio-emotional environment of young football players
Impedancias dinámicas en zapatas rígidas y flexibles sobre medios viscoelásticos
Se presentan aplicaciones recientes del Método de los Elementos
de Contorno al cálculo de impedancias de cimentaciones
en terrenos viscoelásticos, haciendo especial hincapié en el tratamiento de medios estratificados para problemas con simetría
de revolución y en la forma de tratar zapatas flexibles
Escalas de respuesta tipo Likert. ¿Es relevante la alternativa 'indiferente'?
En tests de actitudes y de personalidad es frecuente utilizar escalas de respuesta tipo Likert. En este tipo de escalas es frecuente también que se presente una catego-ría intermedia. Esta categoría representa una posición intermedia a lo largo del continuo y entre las categorías adyacentes. El presente estudio evalúa si las categorías de las escalas de respuesta de una serie de cuestionarios frecuentemente utilizados en la evaluación organizacional se presentan realmente ordenadas, tal y como asume el sistema de puntuación empleado. Asimismo, se evalúa si la categoría intermedia ("indiferente") es relevante en términos de probabilidad de respuesta. Los cuestionarios analizados presentan una escala de respuesta tipo Likert de cinco puntos. Para lograr los objetivos propuestos, se ha aj ustado el modelo nominal de Bock (1972). Los resultados obtenidos indican que si bien las categorías de respuesta aparecen ordenadas, la categoría intermedia"indiferente" no es relevante, es decir, en ningún intervalo de valores del rasgo latente aparece como la alternativa que presenta una mayor probabilidad de respuesta. Estos resultados sugieren eliminar la citada categoría de respuesta de las escalas de respuesta empleadas
Employment outcomes for people with schizophrenia spectrum disorder: A meta-analysis of randomized controlled trials
Parásitos intestinales en fangos de depuradora y posible riesgo asociado a su reutilización
La reutilización de fangos de salida de depuradora se ha convertido en un valioso recurso dado su contenido en nutrientes. Sin embargo, puede suponer un riesgo para la salud pu´blica si su higienización no es adecuada, por la variedad de potenciales pato´genos que pueden contener. La normativa vigente sobre reutilización de fangos (RD 1310/90 y AAA/1072/2013) únicamente hace referencia a la presencia de E. coli y Salmonella spp. Sin embargo, varios estudios sugieren que el uso tradicional de bacterias indicadoras de contaminacio´n fecal no predice la presencia de otros pato´genos como para´sitos y protozoos1. Giardia duodenalis, Cryptosporidium spp. o Entamoeba spp. son protozoos distribuidos mundialmente, causantes de trastornos gastrointestinales en gran número de hospedadores y transmitidos principalmente por el consumo de agua y alimentos de consumo crudo contaminados
In silico mechano-chemical model of bone healing for the regeneration of critical defects: The effect of BMP-2
The healing of bone defects is a challenge for both tissue engineering and modern ortho- paedics. This problem has been addressed through the study of scaffold constructs com- bined with mechanoregulatory theories, disregarding the influence of chemical factors and their respective delivery devices. Of the chemical factors involved in the bone healing pro- cess, bone morphogenetic protein-2 (BMP-2) has been identified as one of the most power- ful osteoinductive proteins. The aim of this work is to develop and validate a mechano- chemical regulatory model to study the effect of BMP-2 on the healing of large bone defects in silico. We first collected a range of quantitative experimental data from the literature con- cerning the effects of BMP-2 on cellular activity, specifically proliferation, migration, differen- tiation, maturation and extracellular matrix production. These data were then used to define a model governed by mechano-chemical stimuli to simulate the healing of large bone de- fects under the following conditions: natural healing, an empty hydrogel implanted in the de- fect and a hydrogel soaked with BMP-2 implanted in the defect. For the latter condition, successful defect healing was predicted, in agreement with previous in vivo experiments. Further in vivo comparisons showed the potential of the model, which accurately predicted bone tissue formation during healing, bone tissue distribution across the defect and the quantity of bone inside the defect. The proposed mechano-chemical model also estimated the effect of BMP-2 on cells and the evolution of healing in large bone defects. This novel in silico tool provides valuable insight for bone tissue regeneration strategies
A mechanistic protrusive-based model for 3D cell migration
Cell migration is essential for a variety of biological processes, such as embryogenesis, wound healing, and the immune response. After more than a century of research—mainly on flat surfaces—, there are still many unknowns about cell motility. In particular, regarding how cells migrate within 3D matrices, which more accurately replicate in vivo conditions. We present a novel in silico model of 3D mesenchymal cell migration regulated by the chemical and mechanical profile of the surrounding environment. This in silico model considers cell’s adhesive and nuclear phenotypes, the effects of the steric hindrance of the matrix, and cells ability to degradate the ECM. These factors are crucial when investigating the increasing difficulty that migrating cells find to squeeze their nuclei through dense matrices, which may act as physical barriers. Our results agree with previous in vitro observations where fibroblasts cultured in collagen-based hydrogels did not durotax toward regions with higher collagen concentrations. Instead, they exhibited an adurotactic behavior, following a more random trajectory. Overall, cell’s migratory response in 3D domains depends on its phenotype, and the properties of the surrounding environment, that is, 3D cell motion is strongly dependent on the context
Computational model of mesenchymal migration in 3D under chemotaxis
Cell chemotaxis is an important characteristic of cellular migration, which takes part in crucial aspects of life and development. In this work, we propose a novel in silico model of mesenchymal 3D migration with competing protrusions under a chemotactic gradient. Based on recent experimental observations, we identify three main stages that can regulate mesenchymal chemotaxis: chemosensing, dendritic protrusion dynamics and cell–matrix interactions. Therefore, each of these features is considered as a different module of the main regulatory computational algorithm. The numerical model was particularized for the case of fibroblast chemotaxis under a PDGF-bb gradient. Fibroblasts migration was simulated embedded in two different 3D matrices – collagen and fibrin – and under several PDGF-bb concentrations. Validation of the model results was provided through qualitative and quantitative comparison with in vitro studies. Our numerical predictions of cell trajectories and speeds were within the measured in vitro ranges in both collagen and fibrin matrices. Although in fibrin, the migration speed of fibroblasts is very low, because fibrin is a stiffer and more entangling matrix. Testing PDGF-bb concentrations, we noticed that an increment of this factor produces a speed increment. At 1 ng mL-1 a speed peak is reached after which the migration speed diminishes again. Moreover, we observed that fibrin exerts a dampening behavior on migration, significantly affecting the migration efficiency
Development and validation of the scale of psychological abuse in intimate partner violence (EAPA-P)
Background: In the context of intimate partner violence, psychological abuse (PA) has progressively gained scientific relevance. Even so, a greater effort is needed to define and evaluate psychological intimate partner abuse. A new exhaustive and operative taxonomy of PA strategies leads to the contribution of a new evaluation instrument. Method: Participants were 101 women between 24 and 82 years old, who were abused by their partners and attended to in different municipal Catalan services, specialized in the topic. Results: The analyses have shown the suitability of a 19-item instrument divided into two factors: (1) direct PA strategies and (2) indirect PA strategies. The former includes strategies that affect the emotional, cognitive and behavioral dimension of the victim. The latter includes items that measure the amount of control and domination over the victim’s context. This scale has adequate psychometric properties in terms of score reliability and the validity of the relationship with other women’s health variables. Conclusions: The EAPA-P, created based on a new definition and taxonomy of the forms of PA, is presented as a valid instrument to detect and measure intimate partner PA
Estudio de la capacidad estabilizadora del peroné en fracturas de tibia de conejo
El objetivo de este trabajo es estudiar la capacidad estabilizadora del peroné en fracturas de tibia. Si dicha capacidad es suficiente, sería posible evitar el uso de sistemas de fijación en los experimentos de laboratorio con este tipo de fracturas. Para comprobarlo se ha realizado una simulación computacional por elementos finitos de la tibia y el peroné de un conejo, con una fractura en el tercio medio superior de la diáfisis sin ningún elemento estabilizador. El conjunto ha sido sometido a las cargas más desfavorables del proceso de salto comprobándose que en este caso el peroné fracturaría en su parte inferior del mismo modo que sucede en la experimentación en laboratorio
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