Transcultural study of perceived competence in physical education and leisure time

El objetivo fue analizar la influencia de la competencia percibida en el sexo, el patrón de actividad físico-deportiva y las etapas de cambio en la práctica de actividad físico-deportiva de tiempo libre. La muestra fue de 2168 estudiantes del primer curso de Enseñanza Secundaria Obligatoria, de Costa Rica (423), México (408) y España (1337). Se realizaron análisis de Chi-cuadrado (x2), tstudent, ANOVA y modelo lineal univariante. Los alumnos con mayor índice de práctica y en etapas activas presentaron una mayor competencia percibida, siendo superior también en los chicos que en las chicas. Por los resultados de esta investigación, hay pocas posibilidades de que la mayoría de los escolares lleguen a ser físicamente activos. Por tanto, en los tres países existe un nivel bajo de actividad físico-deportiva que podría mejorar a través de diseños metodológicos en la Educación Física escolar orientados a la mejora de competenciaThe objective was to analyze the influence of perceived competence on gender, the pattern of physical-sport activity and the stages of change in the practice of physical activity in leisure. The sample was of 2168 students of the first course of Compulsory Secondary Education, of Costa Rica (423), Mexico (408) and Spain (1337). Chi-square (x2), t-student, ANOVA and univariate linear model analyzes were performed. The students with the highest index of practice and in active stages presented a greater perceived competence, also being superior in the boys than in the girls. From the results of this research, it is very probably that most schoolchildren will not become physically active. Therefore, in the three countries there is a low level of physical-sport activity that could be improved through methodological designs in Physical Education aimed at improving perceived competenc

EFECTO DE LA SUPLEMENTACIÓN CON FUENTES DE COBRE SOBRE EL COMPORTAMIENTO PRODUCTIVO, MORFOMETRÍA INTESTINAL Y NIVEL DE COBRE HEPÁTICO EN POLLOS DE CARNE.

This study aimed to evaluate the effect of different copper sources on broilerperformance, intestinal morphology and liver copper contents. Two hundred one-dayold Cobb 500 male chicks were randomly distributed into five groups, using 4 replicates and 10 birds per replicate. The treatments were: T1, basal diet containing antibiotic(positive control); T2, basal diet without antibiotic (negative control); T3, as T2 + 250ppm Cu from copper sulphate; T4, as T2 + 250 ppm Cu from copper oxychloride; T5, T2 +250 ppm Cu from tribasic copper chloride. No significant differences were found betweentreatments on final body weight, daily body weight gain, cost/benefit ratio and carcassyield. The lowest feed intake and the best feed efficiency were observed in T2 as comparedto T1 and T2 (p<0.05). The highest copper content in liver occurred in T5 (p<0.05).Copper supplements affected villus height and area in jejunum as compared to the control groups. It is concluded that supplementation with 250 ppm Cu from copper sulphateimproves feed efficiency and that copper supplementation regardless the source affectedintestinal morphology.El estudio tuvo por objetivo evaluar el efecto de la suplementación de cobre sobre el comportamiento productivo, los niveles de cobre en el hígado y la morfometría intestinal en pollos de 0 a 40 días de edad. Se emplearon 200 pollos BB machos de la Línea Cob500, distribuidos en cinco tratamientos con cuatro repeticiones y 10 animales por repetición: T1, dieta basal con zinc bacitracina (control positivo); T2, dieta basal sin antibiótico(control negativo); T3, dieta basal con sulfato de cobre; T4, dieta basal con oxicloruro de cobre; T5, dieta basal con cobre clorado tribásico (CCTB). El cobre suplementado fue de 250 mg/kg. No se encontró diferencia estadística en peso corporal, ganancia de pesodiario, rendimiento de carcasa y rendimiento económico. El índice de conversión y el consumo de alimento fueron mejores en T3 en relación a T1 y T2 (p<0.05). El mayor nivel de cobre en hígado fue en T5 (p<0.05). Asimismo, la suplementación de cobre influyó la altura y área de vellosidad en el yeyuno comparado a los grupos control. Se concluye que con la suplementación de 250 ppm Cu, proveniente del sulfato de cobre, se mejora la conversión alimenticia y que la suplementación de cobre, independientemente de la fuente, afecta la morfología intestinal

Dissecting the RELICS cluster SPT-CLJ0615-5746 through the intracluster light: confirmation of the multiple merging state of the cluster formation

The intracluster light (ICL) fraction, measured at certain specific wavelengths, has been shown to provide a good marker for determining the dynamical stage of galaxy clusters, i.e., merging versus relaxed, for small to intermediate redshifts. Here, we apply it for the first time to a high-redshift system, SPT-CLJ0615-5746 at z=0.97, using its RELICS (Reionization Lensing Cluster Survey) observations in the optical and infrared. We find the ICL fraction signature of merging, with values ranging from 16 to 37%. A careful re-analysis of the X-ray data available for this cluster points to the presence of at least one current merger, and plausibly a second merger. These two results are in contradiction with previous works based on X-ray data, which claimed the relaxed state of SPT-CLJ0615-5746, and confirmed the evidences presented by kinematic analyses. We also found an abnormally high ICL fraction in the rest-frame near ultraviolet wavelengths, which may be attributed to the combination of several phenomena such as an ICL injection during recent mergers of stars with average early-type spectra, the reversed star formation-density relation found at this high redshift in comparison with lower-redshift clusters, and projection effects.Comment: 15 pages, 12 figures, submitted to A&

Extremely Metal-Poor Galaxies: The HI Content

Extremely metal-poor (XMP) galaxies are chemically, and possibly dynamically, primordial objects in the local Universe. Our objective is to characterize the HI content of the XMP galaxies as a class, using as a reference the list of 140 known local XMPs compiled by Morales-Luis et al. (2011). We have observed 29 XMPs, which had not been observed before at 21 cm, using the Effelsberg radio telescope. This information was complemented with HI data published in literature for a further 53 XMPs. In addition, optical data from the literature provided morphologies, stellar masses, star-formation rates and metallicities. Effelsberg HI integrated flux densities are between 1 and 15 Jy km/s, while line widths are between 20 and 120 km/s. HI integrated flux densities and line widths from literature are in the range 0.1 - 200 Jy km/s and 15 - 150 km/s, respectively. Of the 10 new Effelsberg detections, two sources show an asymmetric double-horn profile, while the remaining sources show either asymmetric (7 sources) or symmetric (1 source) single-peak 21 cm line profiles. An asymmetry in the HI line profile is systematically accompanied by an asymmetry in the optical morphology. Typically, the g-band stellar mass-to-light ratios are ~0.1, whereas the HI gas mass-to-light ratios may be up to 2 orders of magnitude larger. Moreover, HI gas-to-stellar mass ratios fall typically between 10 and 20, denoting that XMPs are extremely gas-rich. We find an anti-correlation between the HI gas mass-to-light ratio and the luminosity, whereby fainter XMPs are more gas-rich than brighter XMPs, suggesting that brighter sources have converted a larger fraction of their HI gas into stars. The dynamical masses inferred from the HI line widths imply that the stellar mass does not exceed 5% of the dynamical mass, while the \ion{H}{i} mass constitutes between 20 and 60% of the dynamical mass. (abridged)Comment: 30 pages, accepted for A&

The metallicity gradient of M 33: chemical abundances of HII regions

We present spectroscopic observations of a sample of 72 emission-line objects, including mainly HII regions, in the spiral galaxy M 33. Spectra were obtained with the multi-object, wide field spectrograph AF2/WYFFOS at the 4.2m WHT telescope. Line intensities, extinction, and electron density were determined for the whole sample of objects. The aim of the present work was to derive chemical and physical parameters of a set of HII regions, and from them the metallicity gradient. Electron temperatures and chemical abundances were derived for the 14 HII regions where both [OII] and [OIII] emission line fluxes were measured, including the electron temperature sensitive emission line [OIII] 436.3 nm and in a few cases [NII] 575.5 nm. The ionization correction factor (ICF) method was used to derive the total chemical abundances. The presence of abundance gradients was inferred from the radial behaviour of several emission-line ratios, and accurately measured from chemical abundances directly derived in 14 HII regions. The oxygen abundances of our HII regions, located in the radial region from ~2 to ~7.2 kpc, gave an oxygen gradient -0.054+/-0.011 dex/kpc The overall oxygen gradient for M 33 obtained using ours and previous oxygen determinations in a large number of HII regions with direct electron temperature determination as well as abundance in young stars presented a two slope shape: -0.19 dex/kpc for the central regions (R<3kpc), and -0.038dex/kpc for the outer regions (R>=3kpc).Comment: 16 pages, 14 figures, A&A accepted 10/05/200

Effect of diets supplemented with phytase and 25-hydroxycholecalciferol on productive performance, and mineralization and integrity of tibias in broilers

El estudio tuvo por objetivo evaluar la suplementación de la enzima fitasa y la vitamina 25-hidroxicolecalciferol (25-OHD3) en dietas para pollos de carne a través de su respuesta productiva y características de la tibia. Se utilizaron 200 pollos machos de la Línea Cobb 500, distribuidos en cuatro tratamientos con cinco repeticiones y 10 animales por repetición: T1, control; T2, iso-nutritivo como T1, considerando la matriz de la fitasa (0.178% Ca y 0.15% Pd – fósforo disponible); T3, iso-nutritivo como T1, considerando la matriz de la 25-OHD3 (0.1% Ca y 0.05% Pd) y T4, iso-nutritivo como T1, considerando las matrices de la fitasa y 25-OHD3. El peso de los pollos y el consumo de alimento fueron registrados los días 7, 14 y 21. El día 21 se midió la longitud y peso de la tibia de 12 pollos por tratamiento. Las tibias izquierdas fueron procesadas para determinar el contenido de ceniza, calcio y fósforo. No se encontró diferencia estadística en peso corporal, ganancia de peso diario o rendimiento de carcasa entre tratamientos. T3 resultó con valores menores en el largo, peso y densidad de la tibia (p&lt;0.05) en comparación a los demás tratamientos. Los porcentajes de cenizas y calcio de la tibia de pollos en T2 y T4 fueron menores a los pollos en T1 o T3 (p&lt;0.05). El porcentaje de fósforo de la tibia de pollos en T2, T3 y T4 fue similar al grupo control (T1). Se concluye que la enzima fitasa, la vitamina 25-OHD3 y la combinación de ambas como suplemento en las dietas de pollos de carne no tuvieron un efecto positivo en el comportamiento productivo de las aves, ni contribuyeron a una eficaz mineralización de la tibia

On faint companions in the close environment of star-forming dwarf galaxies. Possible external star formation triggers ?

We have searched for companion galaxies in the close environment of 98 star-forming dwarf galaxies (SFDGs) from field and low density environments, using the NASA Extragalactic Database. Most of the companions are dwarf galaxies which due to observational selection effects were previously disregarded in environmental studies of SFDGs. A subsample at low redshift, cz<2000 km/s, was chosen to partially eliminate the observational bias against distant dwarf companions. We find companion candidates for approximately 30% of the objects within a projected linear separation s_p<100 kpc and a redshift difference (Delta cz)<500 km/s. The limited completeness of the available data sets, together with the non-negligible frequency of HI clouds in the vicinity of SFDGs indicated by recent radio surveys, suggest that a considerably larger fraction of these galaxies may be accompanied by low-mass systems. This casts doubt on the hypothesis that the majority of them can be considered truly isolated. The velocity differences between companion candidates and sample SFDGs amount typically to (Delta cz)<250 km/s, and show a rising distribution towards lower (Delta cz). This is similarly found for dwarf satellites of spiral galaxies, suggesting a physical association between the companion candidates and the sample SFDGs. SFDGs with a close companion do not show significant differences in their Hbeta equivalent widths and B-V colours as compared to isolated ones. However, the available data do not allow us to rule out that interactions with close dwarf companions can influence the star formation activity in SFDGs.Comment: 9 pages, 5 figures, to appear in A&A; also available at http://www.uni-sw.gwdg.de/~knoeske/PUB_LIST/sfdg_comps.ps.g

Rendimiento Productivo e Integridad Ósea de Pollos de Carne en Respuesta a Suplementación Dietaria con Cuatro Fuentes de Fitasa Comercial

The aim of this study was to determine the effects of four sources of commercial phytases on the performance and bone integrity of broilers from 1 to 28 days of age. Three hundred 1-day old Cobb 500 male chickens were distributed in 30 pens (10 birds per pen) and fed with the experimental diets for 28 days. The treatments were: T1, diet with adequate phosphorus (PAD); T2, phosphorus deficient diet (PDD); T3, PDD + phytase A (100 g/t); T4, PDD + phytase B (100 g/t); T5, PDD + phytase C (50 g/t) and T6, PDD + phytase D (50 g/t). Feeds and water were provided ad libitum. Body weight, body weight gain, feed consumption, feed conversion, and mortality were recorded weekly. At 28 days of age, 20 chicks per treatment were slaughtered to determine carcass and leg yield and tibia weight, plus bone moisture and ash content in the tibia. The results showed that the productive performance of broilers fed diets with normal levels of phosphorus (T1) were significantly higher (p&lt;0.05) than chicks in the other treatments. Similarly, treatments T3 and T5 and treatments T4 and T6 presented similar responses, while T2 (deficient level of phosphorus) showed lower yields. Bone ash in all treatments, except for T2 (p&lt;0.05), showed adequate levels. It was concluded that the productive responses of the birds that received diets deficient in phosphorus with the addition of phytase were lower than the level of response of the birds fed the diet with adequate level of phosphorus.El objetivo del presente ensayo fue determinar el efecto de cuatro fuentes de fitasas comerciales sobre el rendimiento productivo y la integridad ósea de pollos de carne de 1 a 28 días de edad. Se utilizaron 300 pollos BB machos de la Línea Cobb 500 distribuidos al azar en 30 corrales en piso (10 aves por corral), alimentados durante 28 días con uno de los siguientes tratamientos: T1, Dieta normal en fósforo (DNP); T2, Dieta deficiente en fósforo (DDP); T3, DDP + Fitasa A (100 g/t); T4, DDP + Fitasa B (100 g/t); T5, DDP + Fitasa C (50 g/t) y T6, DDP + Fitasa D (50 g/t). El suministro de alimento y agua fue ad libitum. El peso vivo, ganancia de peso, consumo de alimento, conversión alimentaria y mortalidad se registraron semanalmente. A los 28 días de edad, 20 aves por tratamiento fueron sacrificados para determinar el rendimiento de carcasa, rendimiento de piernas, peso de tibias y, posteriormente, contenidos de humedad y ceniza en tibias. Los resultados mostraron que el comportamiento productivo de los pollos de carne alimentados con niveles normales de fósforo (T1) fueron significativamente superiores (p&lt;0.05) al resto de tratamientos; asimismo, los tratamientos T3 y T5 y los tratamientos T4 y T6 presentaron respuestas similares, mientras que T2 (nivel deficiente de fósforo), mostró rendimientos menores. Las tibias de las aves de los tratamientos, con excepción del T2 (p&lt;0.05), mostraron niveles adecuados de cenizas. Se concluye que las respuestas productivas de las aves que recibieron la dieta deficiente en fósforo con la adición de fitasas fueron menores que el nivel de respuesta de las aves alimentadas con la dieta normal en fósforo

Effect of supplementation with dietary yacon meal or copaiba oil on broiler performance and intestinal integrity of broilers inoculated with coccidia

El estudio tuvo por objetivo evaluar el efecto de la suplementación de harina de yacón (Smallanthus sonchifolius) y de aceite de copaiba en el comportamiento productivo y morfometría intestinal en pollos de 1 a 21 días de edad y desafiados con coccidias (Eimeria) a los 14 días de edad. Se emplearon 120 pollos BB machos de la Línea Cobb 500, distribuidos en cuatro tratamientos con tres repeticiones y 10 animales por repetición: T1, dieta basal (sin coccidiostato); T2 dieta basal + coccidiostato; T3 dieta basal + harina de yacón (0.25%) y T4, dieta basal + aceite de copaiba (0.15 ml/kg). Al final del ensayo se sacrificaron 6 aves por tratamiento y se tomaron muestras de intestino delgado para medir la altura de vellosidad, profundidad de cripta, número de células caliciformes y relación altura de vellosidad/profundidad de cripta. Asimismo, se hizo el recuento de ooquistes/g de heces. No se encontró diferencia estadística en ganancia de peso, consumo de alimento ni en conversión alimenticia. Tampoco se encontró diferencia estadística para la altura de vellosidades. Aves tratadas con aceite de copaiba (T4) presentaron mayor profundidad de cripta en duodeno y menor número de células calciformes en íleon (p&lt;0.05). No hubo diferencias estadísticas en el recuento de ooquistes. La suplementación con aceite de copaiba mostró tener un efecto sobre la regeneración celular a nivel intestinal en pollos infectados experimentalmente con Eimeria