573 research outputs found
Efectos del género en la percepción de apoyo de las necesidades psicológicas básicas en educación física
El rol que ejerce el maestro de Educación Física en el desarrollo óptimo de los procesos motivacionales y en la promoción de la práctica de actividad física de niños y adolescentes es una temática de interés creciente en los últimos años. En este sentido, la adopción de estilos más activos y saludables en el tiempo de ocio constituye uno de los principales objetivos que rigen el curriculum ordinario. Así, siguiendo la Teoría de la Autodeterminación (Ryan & Deci, 2002) el objetivo del presente estudio fue analizar la percepción del apoyo de las necesidades psicológicas básicas (autonomía, competencia y relaciones sociales) de los discentes en las clases de Educación Física, en función del género. En el estudio participaron 158 alumnos de 10 a 12 años (M edad = 10.81, DT = 0.62), 76 chicos y 82 chicas y sus 6 maestros (3 varones y 3 mujeres) de Educación Física (M edad = 39.75; DT = 0.48). Para ello, se midió este antecedente social a través del Cuestionario de Apoyo a las Necesidades Psicológicas Básicas (Sánchez-Oliva, Leo, Sánchez-Miguel, Amado & García-Calvo, 2013). Los resultados señalan que los chicos presentan valores significativamente superiores que las chicas en la percepción de apoyo a la competencia y apoyo a la autonomía. Por tanto, se proponen como implicaciones prácticas que los docentes traten de apoyar los mediadores psicológicos mediante diferentes estrategias de intervención, haciendo hincapié en el género femenino. Para ello, la formación en teorías y estrategias motivacionales parece una de las líneas educativas prioritarias en los planes de formación docente
Characterization of nuclear material by Neutron Resonance Transmission Analysis
The use of Neutron Resonance Transmission Analysis for the
characterization of nuclear materials is discussed. The method, which relies on resonance structures in neutron-induced reaction cross sections, can be applied as a non-destructive method to characterise complex nuclear materials such as melted fuel resulting from a severe nuclear accident. Results of a demonstration experiment at the GELINA facility reveal that accurate data can be obtained at a compact facility even in the case of strong overlapping resonances
High accuracy 234U(n,f) cross section in the resonance energy region
New results are presented of the 234U neutron-induced fission cross section, obtained with high accuracy in the resonance region by means of two methods using the 235U(n,f) as reference. The recent evaluation of the 235U(n,f) obtained with SAMMY by L. C. Leal et al. (these Proceedings), based on previous n-TOF data [1], has been used to calculate the 234U(n,f) cross section through the 234U/235U ratio, being here compared with the results obtained by using the n-TOF neutron flux
Neutron cross-sections for advanced nuclear systems : The n-TOF project at CERN
© Owned by the authors, published by EDP Sciences, 2014 This is an Open Access article distributed under the terms of the Creative Commons Attribution License 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly citedThe study of neutron-induced reactions is of high relevance in a wide variety of fields, ranging from stellar nucleosynthesis and fundamental nuclear physics to applications of nuclear technology. In nuclear energy, high accuracy neutron data are needed for the development of Generation IV fast reactors and accelerator driven systems, these last aimed specifically at nuclear waste incineration, as well as for research on innovative fuel cycles. In this context, a high luminosity Neutron Time Of Flight facility, n-TOF, is operating at CERN since more than a decade, with the aim of providing new, high accuracy and high resolution neutron cross-sections. Thanks to the features of the neutron beam, a rich experimental program relevant to nuclear technology has been carried out so far. The program will be further expanded in the near future, thanks in particular to a new high-flux experimental area, now under construction.Peer reviewedFinal Published versio
Towards the high-accuracy determination of the 238U fission cross section at the threshold region at CERN - N-TOF
The 238U fission cross section is an international standard beyond 2 MeV where the fission plateau starts. However, due to its importance in fission reactors, this cross-section should be very accurately known also in the threshold region below 2 MeV. The 238U fission cross section has been measured relative to the 235U fission cross section at CERN - n-TOF with different detection systems. These datasets have been collected and suitably combined to increase the counting statistics in the threshold region from about 300 keV up to 3 MeV. The results are compared with other experimental data, evaluated libraries, and the IAEA standards
Retrospective analysis of melanocytic lesions in children at the National Cancer Institute-RJ
Multiple unbiased approaches identify oxidosqualene cyclase as the molecular target of a promising anti-leishmanial
Phenotypic screening identified a benzothiophene compound with activity against Leishmania donovani, the causative agent of visceral leishmaniasis. Using multiple orthogonal approaches, oxidosqualene cyclase (OSC), a key enzyme of sterol biosynthesis, was identified as the target of this racemic compound and its enantiomers. Whole genome sequencing and screening of a genome-wide overexpression library confirmed that OSC gene amplification is associated with resistance to compound 1. Introduction of an ectopic copy of the OSC gene into wild-type cells reduced susceptibility to these compounds confirming the role of this enzyme in resistance. Biochemical analyses demonstrated the accumulation of the substrate of OSC and depletion of its product in compound (S)-1-treated-promastigotes and cell-free membrane preparations, respectively. Thermal proteome profiling confirmed that compound (S)-1 binds directly to OSC. Finally, modeling and docking studies identified key interactions between compound (S)-1 and the LdOSC active site. Strategies to improve the potency for this promising anti-leishmanial are proposed
- …