¿Se puede mejorar el aprendizaje espacial con las PAU? Un estudio de caso: la PAU de Geografía de Valencia de 2012

Las Pruebas de Acceso a la Universidad (PAU) han sido establecidas en el sistema escolar para seleccionar el alumnado en el momento de ingresar en los estudios universitarios, pero al mismo tiempo para valorar el aprendizaje realizado en los estudios previos. En este artículo queremos mostrar algunas evidencias de que las PAU, al menos en el caso de la Geografía, pueden servir para mejorar el aprendizaje del alumnado, además de ofrecer explicaciones pragmáticas que ayudarían a mejorar la selección del alumnado en relación con sus competencias. Todo ello gracias al estudio de una muestra representativa de exámenes que desvela el nivel cognitivo de las respuestas de los alumnos, extrayendo conclusiones muy interesantes

Detección y seguimiento de desnutrición en ancianos no institucionalizados por el farmacéutico comunitario en las Islas Baleares

Introducción: La desnutrición es un factor de morbi-mortalidad que frecuentemente pasa desapercibido. La detección precoz y un tratamiento adecuado pueden mejorar el pronóstico. En este sentido el farmacéutico comunitario puede ser un agente sanitario útil.Objetivos: Comparar el estado nutricional de personas mayores de 65 años no institucionalizadas en Baleares, antes y después de la intervención del farmacéutico comunitario, y estimar la prevalencia y factores de riesgo de desnutrición en la comunidad.Material y método: Se realizó un cribado mediante el cuestionario MNA entre personas mayores de 65 años usuarias de farmacias comunitarias. En caso de resultar desnutrición o riesgo de padecerla, el farmacéutico comunitario realizó una acción de educación nutricional y se emplazó a los pacientes a dos revisiones a los 3 y 6 meses.Resultados: Se obtuvieron 392 encuestas de las cuales resultó una prevalencia de malnutrición de 0,8% y un riesgo de malnutrición de 12,2%. De los pacientes incluidos en seguimiento solo 14 acabaron el programa. No es un resultado representativo estadísticamente, sin embargo se obtuvo una mejora del estado nutricional en el 45% de ellos.Discusión y conclusiones: El farmacéutico comunitario puede contribuir a detección precoz de la desnutrición, la mejora y el seguimiento del estado nutricional de los pacientes. A pesar de que la mejora en el estado nutricional de los pacientes se debió a la intervención del farmacéutico, se necesitan más estudios para confirmar el efecto de dicha intervención farmacéutica

Angular dependence of the artificially induced anistropy in α-axis-oriented EuBa_2Cu_3O_7/PrBa_2Cu_3O_7 superconducting superlattices

α-axis-oriented EuBa_2Cu_3O_7/PrBa_2Cu_3O_7 (EBCO/PBCO) superlattices allow us to separate contributions to the anisotropy coming from the natural layered structure of EBCO from that introduced by the artificial layering with PBCO. The angular dependence of the critical current and resistivity in a magnetic field has been studied with different superlattice modulation lengths (strong coupling regime). The increase in the insulating PBCO layer thickness produces a crossover from an a-axis-oriented three-dimensional (3D) superconductor with a distribution of planar pinning centers to a 3D superconductor with an angular anisotropy behavior similar to single-phase c-axis-oriented films

Thermophilic co-digestion of organic fraction of municipal solid wastes with FOG wastes from a sewage treatment plant : reactor performance and microbial community monitoring

Working at thermophilic conditions instead of mesophilic, and also the addition of a co-substrate, are both ways to intend to improve the anaerobic digestion of the source-collected organic fraction of municipal solid wastes (SC-OFMSW). Addition of sewage treatment plant fat, oil and grease wastes (STP-FOGW), that are nowadays sent to landfill, would represent an opportunity to recover a wasted methane potential and, moreover, improve the whole process. In this study, after a first period feeding only SC-OFMSW, a co-digestion step was performed maintaining thermophilic conditions. During the co-digestion period enhancements in biogas production (52 %) and methane yield (38 %) were achieved. In addition, monitoring of microbial structure by using PCR-DGGE and cloning techniques showed that bacterial community profiles clustered in two distinct groups, before and after the extended contact with STP-FOGW, being more affected by the STP-FOGW addition than the archaeal one.The financial support from Fundacao para a Ciencia e Tecnologia (FCT) and European Community fund FEDER, trough Program COMPETE, in the ambit of the Project FCOMP-01-0124-FEDER-007087 (PTDC/BIO/69745/2006) and from Xarxa de Referencia en Biotecnologia (Generalitat de Catalunya) is gratefully acknowledged. Lucia Martin thanks Universitat Autonoma de Barcelona for a pre-doctoral fellowship

Experimental adiabatic vortex ratchet effect in Nb films with asymmetric pinning trap

Nb films grown on top of an array of asymmetric pinning centers show a vortex ratchet effect. A net flow of vortices is induced when the vortex lattice is driven by fluctuating forces on an array of pinning centers without reflection symmetry. This effect occurs in the adiabatic regime and it could be mimiced only by reversible DC driven forces

Magnetic properties of Ni nanoparticles dispersed in silica prepared by high-energy ball milling

We analyze the magnetic properties of mechanically ground nanosized Ni particles dispersed in a SiO_2 matrix. Our magnetic characterization of the as-milled samples show the occurrence of two blocking processes and that of non-monotonic milling time evolutions of the magnetic-order temperature, the high-field magnetization and the saturation coercivity. The measured coercivities exhibit giant values and a uniaxial- type temperature dependence. Thermal treatment carried out in the as-prepared samples result in a remarkable coercivity reduction and in an increase of the high-field magnetization. We conclude, on the basis of the consideration of a core (pure Ni) and shell (Ni-Si inhomogeneous alloy) particle structure, that the magnetoelastic anisotropy plays the dominant role in determining the magnetic properties of our particles

Anisotropic pinning enhancement in Nb films with arrays of submicrometric Ni lines

Arrays of submicrometric Ni lines have been fabricated in superconducting Nb films by electron beam lithography. In the mixed state, these arrays induce strong anisotropy in the dissipation behavior. The dissipation is reduced several orders of magnitude, in the whole applied magnetic field range, when the vortex motion is perpendicular to the Ni lines (applied current parallel to them) in comparison with dissipation of vortices moving parallel to the lines. In addition, for the samples studied in this work, a change in the slope of the ρ(B) curves is observed when the vortices move perpendicular to the lines and the vortex lattice parameter matches the width of the Ni lines. © 2002 American Institute of Physics.The authors want to thank Spanish CICYT MAT2002- 04543 and ESF Vortex program. D.J. and E.M.G. thank Ministerio de Ciencia y Tecnologı´a ~Spain! for Ramo´n y Cajal Contracts.Peer reviewe

Lattice effects and current reversal in superconducting ratchets

Competition between the vortex lattice and a lattice of asymmetric artificial defects is shown to play a crucial role in ratchet experiments in superconducting films. We present a novel and collective mechanism for current reversal based on a reconfiguration of the vortex lattice. In contrast to previous models of vortex current reversal, the mechanism is based on the global response of the vortex lattice to external forces.Comment: 12 pages, 7 figure

Experimental vortex ratchet effect in nanostructured superconductors

Superconducting Nb thin films were grown on different arrays of triangle-shape metallic islands. The vortex lattice dynamics could be strongly modified by these asymmetric vortex traps. These asymmetric pinning potentials lead to a rectification effect on the vortex motion: Injecting an ac supercurrent on the sample yields a net dc vortex flow. This vortex ratchet ffect is adiabatic and reversible: The effect is frequency independent and the polarity of the dc voltage output could be tuned by the applied magnetic fields and the input ac currents