1,528 research outputs found
La vivienda social vista por los católicos: el patronato de las viviendas del congreso eucarístico de Barcelona (1952-1965)
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
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
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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
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
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
The Periosteal Bone Surface is Less Mechano-Responsive than the Endocortical
Dynamic processes modify bone micro-structure to adapt to external loading and
avoid mechanical failure. Age-related cortical bone loss is thought to occur
because of increased endocortical resorption and reduced periosteal formation.
Differences in the (re)modeling response to loading on both surfaces, however,
are poorly understood. Combining in-vivo tibial loading, in-vivo micro-
tomography and finite element analysis, remodeling in C57Bl/6J mice of three
ages (10, 26, 78 week old) was analyzed to identify differences in mechano-
responsiveness and its age-related change on the two cortical surfaces.
Mechanical stimulation enhanced endocortical and periosteal formation and
reduced endocortical resorption; a reduction in periosteal resorption was
hardly possible since it was low, even without additional loading.
Endocortically a greater mechano-responsiveness was identified, evident by a
larger bone-forming surface and enhanced thickness of formed bone packets,
which was not detected periosteally. Endocortical mechano-responsiveness was
better conserved with age, since here adaptive response declined continuously
with aging, whereas periosteally the main decay in formation response occurred
already before adulthood. Higher endocortical mechano-responsiveness is not
due to higher endocortical strains. Although it is clear structural adaptation
varies between different bones in the skeleton, this study demonstrates that
adaptation varies even at different sites within the same bone
Genetic variability in two spanish horse populations: preliminary results
The genetic variability has been analyzed through the allelic frequencies distribution of ten STR (Short Tandem Repeat) equine loci of three different horse populations, Asturcón, Pottoka and Thoroughbred (PSI), which is considered as an outgroup. The genetic variability found in the pony breeds is higher than for PSI and only one of the ten loci analyzed is significantly desviated from Hardy-Weinberg equilibrium (= 0.01) in Asturcón and Pottoka populations. The FST value (0.054) shows a significant divergence between Asturcón and Pottoka, besides the genetic distance calculated between both populations is very lower compared to their relation with PSI.Para el estudio de la variabilidad genética de tres poblaciones diferentes de caballos, Asturcón, Pottoka y Pura Sangre Inglés (PSI), habiéndose constituido esta última como población de referencia, se ha analizado la distribución de las frecuencias alélicas de 10 STR (Short Tandem Repeat) loci equinos. La variabilidad genética encontrada en las razas de ponis es superior a la del PSI y solo uno de los loci analizados se desvía significativamente del equilibrio Hardy- Weinberg (=0,01) en las poblaciones de Asturcón y Pottoka. El valor FST estimado (0,054) muestra una divergencia significativa entre Asturcón y Pottoka, asimismo la distancia genética calculada entre ambas poblaciones es inferior comparada a la que tienen ambas con respecto al PSI
La Formación de Bellmunt (Unidad del Cadí, Pirineo oriental): aportaciones bioestratigráficas de los sistemas lacustres y palustres asociados
The Bellmunt Fm is an alluvial synorogenic unit which was deposited under the influence of the southward displacement of succesive pyrenean nappes. This unit includes, in the boundary between its lower and middle part, many lacustrine and palustrine beds with an abundant fossil fauna and flora. This fossil record allows to recognize thepaleoenviromental andpaleoclimatic scenary. Charophytes and fossil mammals indicate a Middle and Lower Bartonian age for this Formation
Bistability in the Tunnelling Current through a Ring of Coupled Quantum Dots
We study bistability in the electron transport through a ring of N coupled
quantum dots with two orbitals in each dot. One orbital is localized (called b
orbital) and coupling of the b orbitals in any two dots is negligible; the
other is delocalized in the plane of the ring (called d orbital), due to
coupling of the d orbitals in the neighboring dots, as described by a
tight-binding model. The d orbitals thereby form a band with finite width. The
b and d orbitals are connected to the source and drain electrodes with a
voltage bias V, allowing the electron tunnelling. Tunnelling current is
calculated by using a nonequilibrium Green function method recently developed
to treat nanostructures with multiple energy levels. We find a bistable effect
in the tunnelling current as a function of bias V, when the size N>50; this
effect scales with the size N and becomes sizable at N~100. The temperature
effect on bistability is also discussed. In comparison, mean-field treatment
tends to overestimate the bistable effect.Comment: Published in JPSJ; minor typos correcte
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