1,057 research outputs found
Spanish validation of the locus of control questionnaire in sport for children
El locus de control ha sido estudiado en el deporte, sin embargo no existía
un instrumento válido para evaluarlo en deporte infantil. Este estudio lleva a cabo
la validación española del Children´s Sport Locus of Control Scale (CSLCS) que
desarrollaron Tsai y Hsieh (2015). La adaptación presenta dos fases: una
primera exploratoria con 248 niños entre 7 y 16 años para observar el
comportamiento cualitativo de los ítems; y una segunda con 221 deportistas
entre 8 y 22 años en la que se modificó el cuestionario para ajustarlo a los
resultados obtenidos. Se obtiene una escala final de 10 ítems, con 5 ítems por
dimensión (interna y externa), que presenta un ajuste adecuado. Los resultados
demuestran que la versión española de la escala posee cualidades
psicométricas adecuadas para ser utilizada en la investigación y la práctica
aplicada en la evaluación deportiva infantilLocus of control has been studied in the sport context, however there was no
valid instrument to evaluate it in children's sport. This study adapts into Spanish
and validates the Children's Locus of Control Scale for Sport (CSLCS) in the
Spanish language. This CSLCS was developed by Tsai y Hsieh (2015). The
adaptation has two phases: an initial screening of 248 children between the
ages of 7 and 16 to observe the qualitative behavior of the items; and a second
one with 221 athletes with children between the ages of 8 and 22 in which the
questionnaire was modified to fit the results. A final 10-item scale was obtained,
with 5 items per dimension (internal and external), which presents an adequate
fit. Results show that the Spanish version of the scale possesses adequate
psychometric qualities for its use in research and applied fields in child´s sport
evaluatio
Crystallographic orientation inhomogeneity and crystal splitting in biogenic calcite
The calcitic prismatic units forming the outer shell of the bivalve Pinctada margaritifera have been analysed using scanning electron microscopy–electron back-scatter diffraction, transmission electron microscopy and atomic force microscopy. In the initial stages of growth, the individual prismatic units are single crystals. Their crystalline orientation is not consistent but rather changes gradually during growth. The gradients in crystallographic orientation occur mainly in a direction parallel to the long axis of the prism, i.e. perpendicular to the shell surface and do not show preferential tilting along any of the calcite lattice axes. At a certain growth stage, gradients begin to spread and diverge, implying that the prismatic units split into several crystalline domains. In this way, a branched crystal, in which the ends of the branches are independent crystalline domains, is formed. At the nanometre scale, the material is composed of slightly misoriented domains, which are separated by planes approximately perpendicular to the c-axis. Orientational gradients and splitting processes are described in biocrystals for the first time and are undoubtedly related to the high content of intracrystalline organic molecules, although the way in which these act to induce the observed crystalline patterns is a matter of future research
Measurement invariance of the Satisfaction with Life Scale by sexual orientation
The Satisfaction with Life Scale (SWLS) has shown strong evidence of reliability, validity, and gender invariance, and there is some evidence of invariance across age, culture, and educational levels. So far, invariance across sexual orientation has not been studied, despite the number of works that relate well-being to sexual orientation. The SWLS should be invariant across sexual orientation to be able to compare group means. This study aimed to explore the invariance of the SWLS across sexual orientation. A non-probabilistic sample with 553 Spanish adults (208 males, 345 females; 212 heterosexuals, 182 gays, and 138 bisexuals among other sexual orientations) participated in a survey. We tested a one-factor model using confirmatory factor analysis. We tested the configural, metric, and scalar invariance of the factorial structure of the SWLS across sexual orientation with heterosexual, lesbian/gay, and bisexual groups. According to our results, the Spanish version of the SWLS shows scalar invariance across sexual orientations, allowing a valid comparison between sexual minority and heterosexual people. Moreover, in our sample, lesbian/gay and bisexual participants obtained lower scores in life satisfaction than heterosexual participants. Bisexual people obtained the lowest score in well-being compared with the other groups. Implications related to the importance of checking instrument invariance before comparing mean differences between groups are discussed.info:eu-repo/semantics/publishedVersio
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The contribution of greenhouse gases to the recent slowdown in global-mean temperature trends
The recent slowdown in the rate of increase in global-mean surface temperature (GMST) has generated extensive discussion, but little attention has been given to the contribution of time-varying trends in greenhouse gas concentrations. We use a simple model approach to quantify this contribution. Between 1985 and 2003, greenhouse gases (including well-mixed greenhouse gases, tropospheric and stratospheric ozone, and stratospheric water vapour from methane oxidation) caused a reduction in GMST trend of around 0.03–0.05 K decade−1 which is around 18%–25% of the observed trend over that period. The main contributors to this reduction are the rapid change in the growth rates of ozone-depleting gases (with this contribution slightly opposed by stratospheric ozone depletion itself) and the weakening in growth rates of methane and tropospheric ozone radiative forcing. Although CO2 is the dominant greenhouse gas contributor to GMST trends, the continued increase in CO2 concentrations offsets only about 30% of the simulated trend reduction due to these other contributors. These results emphasize that trends in non-CO2 greenhouse gas concentrations can make significant positive and negative contributions to changes in the rate of warming, and that they need to be considered more closely in analyses of the causes of such variations
Benefits of vibration training in the neuromuscular system of the elderly
Introducción: El entrenamiento vibratorio puede ser una opción de intervención óptima para prevenir la pérdida de masa muscular en adultos mayores.
Objetivo: Comprobar la efectividad del entrenamiento vibratorio en el sistema neuromuscular de los adultos mayores.
Material y método: Revisión bibliográfica en las bases de datos Medline, CINAHL, WOS y PEDro, mediante la combinación de los descriptores del Medical Subjects Headings referentes a entrenamiento vibratorio, fuerza muscular, masa muscular y personas mayores.
Resultados: Los estudios localizados sobre el entrenamiento vibratorio en personas mayores se realizaron, bien como única intervención, o en combinación con otro tipo de ejercicios de fuerza, aeróbicos, de equilibrio o de flexibilidad. La diversidad de protocolos empleados dificulta una comparación entre estudios.
Conclusión: El entrenamiento con plataformas vibratorias demuestra ser un método de entrenamiento de la fuerza seguro, adecuado y eficaz para la población de mayor edad, pero con resultados similares al ejercicio de resistencia convencional
Structure and crystallography of foliated and chalk shell microstructures of the oyster Magallana: the same materials grown under different conditions.
Oyster shells are mainly composed of layers of foliated microstructure and lenses of chalk, a highly porous, apparently poorly organized and mechanically weak material. We performed a structural and crystallographic study of both materials, paying attention to the transitions between them. The morphology and crystallography of the laths comprising both microstructures are similar. The main differences were, in general, crystallographic orientation and texture. Whereas the foliated microstructure has a moderate sheet texture, with a defined 001 maximum, the chalk has a much weaker sheet texture, with a defined 011 maximum. This is striking because of the much more disorganized aspect of the chalk. We hypothesize that part of the unanticipated order is inherited from the foliated microstructure by means of, possibly, [Formula: see text] twinning. Growth line distribution suggests that during chalk formation, the mantle separates from the previous shell several times faster than for the foliated material. A shortage of structural material causes the chalk to become highly porous and allows crystals to reorient at a high angle to the mantle surface, with which they continue to keep contact. In conclusion, both materials are structurally similar and the differences in orientation and aspect simply result from differences in growth conditions
Myristic acid potentiates palmitic acid-induced lipotoxicity and steatohepatitis associated with lipodystrophy by sustaning de novo ceramide synthesis.
Palmitic acid (PA) induces hepatocyte apoptosis and fuels de novo ceramide synthesis in the endoplasmic reticulum (ER). Myristic acid (MA), a free fatty acid highly abundant in copra/palmist oils, is a predictor of nonalcoholic steatohepatitis (NASH) and stimulates ceramide synthesis. Here we investigated the synergism between MA and PA in ceramide synthesis, ER stress, lipotoxicity and NASH. Unlike PA, MA is not lipotoxic but potentiated PA-mediated lipoapoptosis, ER stress, caspase-3 activation and cytochrome c release in primary mouse hepatocytes (PMH). Moreover, MA kinetically sustained PA-induced total ceramide content by stimulating dehydroceramide desaturase and switched the ceramide profile from decreased to increased ceramide 14:0/ceramide16:0, without changing medium and long-chain ceramide species. PMH were more sensitive to equimolar ceramide14:0/ceramide16:0 exposure, which mimics the outcome of PA plus MA treatment on ceramide homeostasis, than to either ceramide alone. Treatment with myriocin to inhibit ceramide synthesis and tauroursodeoxycholic acid to prevent ER stress ameliorated PA plus MA induced apoptosis, similar to the protection afforded by the antioxidant BHA, the pan-caspase inhibitor z-VAD-Fmk and JNK inhibition. Moreover, ruthenium red protected PMH against PA and MA-induced cell death. Recapitulating in vitro findings, mice fed a diet enriched in PA plus MA exhibited lipodystrophy, hepatosplenomegaly, increased liver ceramide content and cholesterol levels, ER stress, liver damage, inflammation and fibrosis compared to mice fed diets enriched in PA or MA alone. The deleterious effects of PA plus MA-enriched diet were largely prevented by in vivo myriocin treatment. These findings indicate a causal link between ceramide synthesis and ER stress in lipotoxicity, and imply that the consumption of diets enriched in MA and PA can cause NASH associated with lipodystrophy
Thermal analysis of space debris for infrared based active debris removal
In space, visual based relative navigation systems suffer from dynamic illumination conditions of the target (Eclipse conditions, solar glare...etc.) where most of these issues are addressed by advanced mission planning techniques. However, such planning would not be always feasible or even if it is, it would not be straightforward for Active Debris Removal (ADR) missions. On the other hand, using an infrared based system would overcome this problem, if a guideline to predict infrared signature of space debris based on the target thermal profile could be provided for algorithm design and testing.
Spacecraft thermal design is unique to every platform. This means every ADR target will have a different infrared signature which changes over time not just only due to orbital dynamics but also due to its thermal surface coatings. In order to provide a space debris infrared signature guideline for most of the possible ADR targets, we introduce an innovative grouping system for thermal surface coatings based on their behaviour in Space environment. Through the use of this grouping system, we propose a space debris infrared signature estimation method which was extensively verified by our simulations and experiments. During our verifications, we have also found out very important problem so called ”Signature Ambiguity” that is unique to Infrared Based Active Debris Removal (IR-ADR) systems which we have also discussed in our work
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