Ser innovador exige cambio constructivo en el docente

Se parte de la hipótesis: “dadas las circunstancias que se vivencian en el campo educativo,es posible que la innovación docente se dé, solo si hay un cambio personal”. Mediante los métodos hermenéutico, interpretativo y exegético se formula algunas interrogantes: ¿Están mejorando los centros de formación o se están destruyendo poco a poco?, ¿por qué hay o no hay fracaso en los centros de formación?, ¿dónde está el error?, ¿cómo mejorar la formación?,y otras. Aborda el contexto cultural, percibiendo que los centros educativos presentan, por lo menos, tres problemas centrales: a) persistencia de un modelo cultural de centros selectivos; b) problemas de fragmentación y anacronismo de las estructuras curriculares y organizativas; y c) cierto escepticismo sobre la posibilidad de cambio. Es necesario estudiar el saber docente partiendo de las crisis y considerando las intenciones y experiencia del profesorado en el aula,como facilitador, guía, orientador y creador de hábitos y destrezas para buscar y seleccionar la información

Composition and luminescence of AlInGaN layers grown by plasma-assisted molecular beam epitaxy

A study of AlInGaN epilayers, grown by plasma-assisted molecular beam epitaxy, was performed using spatially resolved x-ray microanalysis and luminescence spectroscopy in order to investigate competition between the incorporation of In, Al, and Ga as a function of the growth temperature in the 565-660 °C range and the nominal AlN mole fraction. The samples studied have AlN and InN mole fractions in the ranges of 4%-30% and 0%-16%, respectively. Composition measurements show the effect of decreasing temperature to be an increase in the incorporation of InN, accompanied by a small but discernible decrease in the ratio of GaN to AlN mole fractions. The incorporation of In is also shown to be significantly increased by decreasing the Al mole fraction. Optical emission peaks, observed by cathodoluminescence mapping and by photoluminescence, provide further information on the epilayer compositions as a function of substrate temperature, and the dependencies of peak energy and linewidth are plotted

On non-formality of a simply-connected symplectic 8-manifold

We show an alternative construction of the first example of a simply-connected compact symplectic non-formal 8-manifold given in arXiv:math/0506449. We also give an alternative proof of its non-formality using higher order Massey products.Comment: 10 pages; to appear in American Institute of Physics Conference Proceedings. Proceedings of the XVI International Fall Workshop on Geometry and Physics, Lisboa 200

Espacios, tiempos y saberes para una subjetividad reflexiva en la escuela primaria Bellaterra

Este artículo presenta los principales resultados de una investigación narrativa sobre la construcción de la subjetividad en la escuela primaria. Dado que en este tipo de investigación, el investigador es considerado un sujeto social en relación con otros, el proceso de escritura de los diarios durante el trabajo de campo etnográfico muestra las tentativas para incluir a los otros en la representación, los diversos momentos de duda, y hace visibles las interrupciones y giros en nuestras posiciones investigadoras. Además, hemos tratado de escapar de la objetivación y fijación del sujeto, planteando una visión relacional y procesual de la subjetividad, a veces incluso fragmentada. Para ello, hemos interpretado la representación de la infancia y del aprendizaje en la escuela, cómo las maestras y los maestros con quienes trabajamos comparten una visión reflexiva, integral, cooperativa y comunitaria del sujeto escolar. También hemos observado e interpretado cómo los niños y niñas desarrollan formas de posicionamiento, identificación y diferenciación desde la relación con los otros. Así, hemos reconstruido cómo se forma la subjetividad infantil a partir de narrar escenas observadas en las aulas de diferentes grupos de niños y niñas y en otros espacios de la escuela donde estos grupos desarrollan diferentes actividadesIn this article we present the results of a narrative inquiry into the construction of subjectivity in primary schools. In this study the researchers' own subjectivities came under the same scrutiny as those who were the focus of the research, and were placed in relation to them. We will discuss the doubts that arose as we carried out our research as well as how our positions as researchers changed over the course of the study. We will also describe our attempts to give voice to teachers and learners through our narratives. This goal led us to produce an account of subjectivity that was relational, process-based, and, sometimes, fragmented. Our interpretation of the representation of childhood/learners and learning in school is based upon how the teachers we have worked with shared a reflective, integral, cooperative, and community view of learning. We will also discuss how learners develop forms of positioning, identification, and differentiation depending on their relationships with others. In this way we have been able to reconstruct the way in which learners' subjectivities are formed by narrating scenes observed in classrooms with different groups of peers, and in other areas of the school where these groups carry out different activitie

Sobre la ocurrencia del cretáceo superior marino en Coihaique , Provincia de Aisén

Using the CCSD­(T) model, we evaluated the intermolecular potential energy surfaces of the He–, Ne–, and Ar–phosgene complexes. We considered a representative number of intermolecular geometries for which we calculated the corresponding interaction energies with the augmented (He complex) and double augmented (Ne and Ar complexes) correlation-consistent polarized valence triple-ζ basis sets extended with a set of 3s3p2d1f1g midbond functions. These basis sets were selected after systematic basis set studies carried out at geometries close to those of the surface minima. The He–, Ne–, and Ar–phosgene surfaces were found to have absolute minima of −72.1, −140.4, and −326.6 cm^–1 at distances between the rare-gas atom and the phosgene center of mass of 3.184, 3.254, and 3.516 Å, respectively. The potentials were further used in the evaluation of rovibrational states and the rotational constants of the complexes, providing valuable results for future experimental investigations. Comparing our results to those previously available for other phosgene complexes, we suggest that the results for Cl₂–phosgene should be revised

FORMULATION OF THE HEAT CONDUCTION EQUATION FOR HETEROGENEOUS MEDIA WITH MULTIPLE SPATIAL SCALES USING REITERATED HOMOGENIZATION

Heterogeneous media with multiple spatial scales are finding increased importance in engineering. An example might be a large scale, otherwise homogeneous medium filled with dispersed small-scale particles that form aggregate structures at an intermediate scale. The objective in this paper is to formulate the strong-form Fourier heat conduction equation for such media using the method of reiterated homogenization. The phases are assumed to have a perfect thermal contact at the interface. The ratio of two successive length scales of the medium is a constant small parameter ε. The method is an up-scaling procedure that writes the temperature field as an asymptotic multiple-scale expansion in powers of the small parameter ε . The technique leads to two pairs of local and homogenized equations, linked by effective coefficients. In this manner the medium behavior at the smallest scales is seen to affect the macroscale behavior, which is the main interest in engineering. To facilitate the physical understanding of the formulation, an analytical solution is obtained for the heat conduction equation in a functionally graded material (FGM). The approach presented here may serve as a basis for future efforts to numerically compute effective properties of heterogeneous media with multiple spatial scales

Comparing the allelopathic potential of exotic and native plant species on understory plants: are exotic plants better armed?

La alelopatía es un mecanismo clave en las invasiones biológicas. Este estudio se propuso analizar el efecto de extractos acuosos de hojas de tres especies de árboles exóticos comunes en bosques ri- parios españoles sobre la germinación de seis herbáceas comunes en su sotobosque. Comparamos los efectos de las especies exóti- cas con los de una especie de árbol nativo, el álamo blanco. Las variables más sensibles a los extractos fueron la velocidad de ger- minación y el crecimiento radicular, mientras que el porcentaje de germinación apenas fue afectado. Principalmente, los extractos tu- vieron un efecto negativo sobre la germinación de todas las espe- cies, excepto Chenopodium album. El álamo blanco causó efectos similares o incluso más negativos que las especies exóticas. Nues- tros resultados muestran que la alelopatía es un fenómeno com- plejo, en el que las especies nativas también están involucradas

Mediterranean springs: Keystone ecosystems and biodiversity refugia threatened by global change

Mediterranean spring ecosystems are unique habitats at the interface between surface water and groundwater. These ecosystems support a remarkable array of biodiversity and provide important ecological functions and ecosystem services. Spring ecosystems are influenced by abiotic, biotic, and anthropogenic factors such as the lithology of their draining aquifers, their climate, and the land use of their recharge area, all of which affect the water chemistry of the aquifer and the spring discharges. One of the most relevant characteristics of spring ecosystems is the temporal stability of environmental conditions, including physicochemical features of the spring water, across seasons and years. This stability allows a wide range of species to benefit from these ecosystems (particularly during dry periods), fostering an unusually high number of endemic species. However, global change poses important threats to these freshwater ecosystems. Changes in temperature, evapotranspiration, and precipitation patterns can alter the water balance and chemistry of spring water. Eutrophication due to agricultural practices and emergent pollutants, such as pharmaceuticals, personal care products, and pesticides, is also a growing concern for the preservation of spring biodiversity. Here, we provide a synthesis of the main characteristics and functioning of Mediterranean spring ecosystems. We then describe their ecological value and biodiversity patterns and highlight the main risks these ecosystems face. Moreover, we identify existing knowledge gaps to guide future research in order to fully uncover the hidden biodiversity within these habitats and understand the main drivers that govern them. Finally, we provide a brief summary of recommended actions that should be taken to effectively manage and preserve Mediterranean spring ecosystems for future generations. Even though studies on Mediterranean spring ecosystems are still scarce, our review shows there are sufficient data to conclude that their future viability as functional ecosystems is under severe threat.Mediterranean spring ecosystems are unique habitats supporting a remarkable array of biodiversity and providing important ecological functions and ecosystem services. However, global change poses important threats to these freshwater ecosystems, such as changes in climate patterns and increasing human pressures like overexploitation and pollution. We provide a synthesis of the main characteristics and functioning of Mediterranean spring ecosystems and their threats due to global change.imag