La investigación cooperativa

La "Collaborative Research" (Investigación cooperativa) se presenta como una alternativa del diseño "R and D" en Educación y una de las modalidades de la "Action Research". Puede considerarse a E.E.U.U. como país pionero de sus más importantes realizaciones. El artículo intenta presentar una síntesis de la evolución histórica de este tipo de investigación, deteniéndose especialmente en sus orígenes, vinculados a la "Action Research"; la crisis de esta ultima; la creación de los diseños interactivos IR and DT de Tikunoff, Ward y Griffin en 1975 (Interactive Research and Development on teaching) en un contexto internacional favorable al resurgimiento de la Action Research y explicitado en diversidad de corrientes y movimientos orientados a potenciar el cambio educativo y social a través de la investigación; finalmente, su expansión actual. Del estudio de las obras de sus representantes principales (Griffin, Oja, Pine, Smulyan, Tikunoff, Ward, etc.), se extraen los elementos que podemos considerar claves para una definición de la Collaborative Research, los procesos y diseños de investigación empleados y las condiciones requeridas para que pueda llevarse a cabo. A partir de este análisis se ofrece una reflexión sobre los problemas concretos vinculados a este tipo de investigación: los que surgen al inicio de la misma; los que se dan en torno al proceso de comunicación y, sobre todo los relacionados con la producción real de conocimiento científico, señalando en cada uno de estos apartados posibles vías de soluci6n, apuntadas desde los nuevos enfoques de la investigación educativa. * Profesora Catedrática del Departamento de Métodos de Investigación y Diagnóstico en Educación.The Collaborative Research to wants to be as an alternative of the design ((R and D)) in Education and one of some kinds of the Action Research. E.E.U.U. can be considerates as the first country in these works. The article wishes to do a short exposition of the historic evolution of this way of Research for to considerer its beginnings in relation at the Action Research and its last crisis; the establishment of the interactive design IR and DT (Interactive Research and Development on Teaching) of Tikunnoff Ward and Griffin in nineteen seventy five in a international favourable contex for a resurgence of the Action Research for to give a stronger at the educative and social change by the way of the Research; finishment its present. Of the study of the works of their principals figures (Griffin, Oja, Pine, Smulyan, Tikunnoff, Ward, etc.) we can take the elements which we can look as Keys for a definition of the Collaborative Research; the ways and designs of Research useds and the conditions for that the process can be done. After of this, we can think about of the specific problems in relation at this way of Research: those that to come at the beginning of itself; those that are given around of the process of communication, and very much those that are connected with the trust"worthiness of the scientific knowledge showing in every one of these possible ways of solution showeds since the news kinds of the Educational Research

Las paradojas de la ética y el derecho: la hermenéutica y sus efectos de poder

Trata dos paradoxos existentes entre a ética e o direito, analisando-os em face da hermenêutica jurídica, tendo em vista a construção do discurso sobre a propriedade privada, especificamente no que tange à terra, ponderando sobre o seu valor ético, a interpretação jurídica e as diversas relações de poder

Enhancement of the magnetic anisotropy of Co clusters by Au capping

et al.We study the magnetic properties of Co nanoparticles, prepared by sputtering, with diameters ranging from 1 to 3.5 nm. The effective anisotropy, which determines the activation energy for the magnetization reversal, increases with decreasing particle's size, showing the dominant role played by surface atoms. We find that the superparamagnetic blocking temperature and the coercive field are significatively enhanced when the clusters are capped by a thin Au layer. This enhancement is probably caused by the bonding or hybridization of Co and Au atoms at the interface between the two metals. It provides thus a method to modify the magnetic anisotropy, which can be of interest for the applications of magnetic nanoparticles.Peer reviewe

Structural and magnetic properties of amorphous Co-W alloyed nanoparticles

18 páginas, 20 figuras, 4 tablas.-- PACS number(s): 75.75.Fk, 75.50.Kj, 75.30.Gw, 61.46.Df.-- et al.et al.W-capped Co nanoparticles dispersed in an alumina matrix are studied by means of high-resolution transmission electron microscopy, extended x-ray absorption fine structure, SQUID-based magnetic measurements, dc magnetization, ac magnetic susceptibility, and x-ray magnetic circular dichroism. Results show the formation of amorphous Co-W alloy nanoparticles, the magnetic properties of which are modified by the amount of W or Co present in the samples. The average Co magnetic moment depends on the number of W atoms surrounding it. Co-W particles show superparamagnetic behavior and are described as an array of noninteracting particles with random anisotropy axes and an average moment per particle proportional to the particle volume and to the average Co moment for each alloy composition. Values of the magnetic anisotropy constant of the particles are on the order of 106 erg/cm3, higher than that of bulk Co. Evidence of short-range ordering within each amorphous particle is found that provides insight of the origin of their magnetic anisotropy.The financial support of MICINN-FEDER MAT08/1077 and Aragonese IMANA project is acknowledged. A.I.F. acknowledges a CSIC JAE2008-Predoc grant.Peer reviewe

European Economies in the First Epoch of Imperialism and Mercantilism. 1415-1846.

The costs and benefits of European Imperialism from the conquest of Ceuta, 1415, to the Treaty of Lusaka, 1974.Twelfth International Economic History Congress. Madrid, 1998.Patrick K. O'Brien and Leandro Prados de la Escosura (eds.)Editada en la Fundación Empresa PúblicaJorge M. Pedreira. «To Have and To Have not». The Economic Consequences of Empire: Portugal (1415-1822).-- Bartolomé Yun-Casalilla. The American Empire and the Spanish Economy: An Institutional and Regional Perspective.-- Pieter C. Emmer. The Economic Impact of the Dutch Expansion Overseas, 1570-1870.-- Paul Butel and François Crouzet. Empire and Economic Growth: the Case of 18th Century France.-- Stanley L. Engerman. British Imperialism in a Mercantilist Age, 1492-1849: Conceptual Issues and Empirical Problems.Publicad

Morphology and magnetic properties of W-capped Co nanoparticles

3 páginas, 3 figuras, 2 tablas.-- et al.Co–W nanoparticles formed by sequential sputtering of Co on amorphous alumina substrate and subsequent W capping are studied by high resolution and by scanning transmission electron microscopies, and by superconducting quantum interference device magnetometry. The analysis is focused on W nominal thickness dependence. Results suggest the formation of amorphous Co–W alloy nanoparticles, whose magnetic moment per Co atom is systematically reduced as the nominal thickness of W capping layer increases. The Co–W nanoparticles show superparamagnetic behavior. The activation energy for moment reversal and the effective anisotropy are obtained.The financial support of MAT08/1077 is acknowledged. A. I. Figueroa acknowledges a JAE-Predoc grant.Peer reviewe

Mössbauer study of the hyperfine interactions and spin dynamics in -iron(II) phthalocyanine

13 pages, 8 figures, 3 tables.-- PACS number(s): 75.50.Xx, 76.80.+y, 75.50.DdThe 57Fe Mössbauer spectroscopy on -iron(II) phthalocyanine (FePc) as a function of temperature (1.3<T<295 K) and applied field (0<B<10 T) has been used to study the peculiar magnetic properties of this ferromagnetic quasilinear chain type compound. One sextet with an internal hyperfine field Bint=66.2 T was observed at 1.3 K, a very large value for a bivalent iron with S=1 pointing to the existence of large positive orbital and dipolar contributions in the investigated FePc. Under an applied field, the experimental spectra exhibited two nonequivalent Fe positions, due to spin canting, with the values for the hyperfine fields of the split sextets increasing with increasing field, an indication that unlike most cases, Bint in -FePc is positive, i.e., parallel to the magnetic moment of iron. Therefore, the origin of the large hyperfine field is the orbital moment rather than the Fermi's contact interaction. This fact is ascribed to the orbital degeneracy of the ground state of Fe(II) in the present configuration, where an unpaired hole occupies the orbital doublet (dxz, dyz). This feature supports and explains the magnetization and susceptibility data as well as the anomalously high hyperfine field observed at 57Fe nucleus. The relaxational behavior in the ac susceptibility and Mössbauer spectra found in the region 5–20 K was ascribed to solitonlike motion of domain walls within the magnetic chains, with a single-kink activation energy of 72 K.This work has been supported by Project No. MAT05/ 1272 of the Spanish Ministry of Education and Science. M. D. Kuz’min acknowledges Grant No. SAB2000-0084. G. F. acknowledges the Royal Society Research Grant at the University of Liverpool and Grant No. SAB2003/0226 from Ministerio de Education, Cultura y Deporte of Spain. The final part of this work was facilitated and supported by EU Network of Excellence MAGMANet.Peer reviewe

Magnetic anisotropy of maghemite nanoparticles probed by RF transverse susceptibility

We present radio frequency magnetic transverse susceptibility measurements on γ-Fe2O3 nanoparticles, which yield an estimation of their effective anisotropy constant, Keff as a function of nanoparticle size. The resulting values range from 4 to 8 × 104 erg/cm3, being on the order of the magnetocrystalline anisotropy in bulk maghemite. Keff values increase as the particle diameter increases. Evidences of anisotropy field distribution given by the size distribution in the samples, and interparticle interactions that increase as the particle size increases, are also observed in the TS measurements. The effects of such interparticle interaction overcome those of thermal fluctuations, in contrast with the behavior of other iron oxide particles.The financial support of the Spanish MINECO MAT2011-23791, MAT2014-53921-R, and MAT2014-54975-R and Aragonese DGA-IMANA E34 and M4 projects is acknowledged.Peer Reviewe

Biphasic effect of insulin on beta cell apoptosis depending on glucose deprivation

AbstractInsulin resistant states are associated with an increase in the beta cell mass and also high levels of circulating insulin. Ultimately the beta cells undergo a failure that leads to diabetes. At this stage, a question arises if those persistent high levels of circulating insulin may contribute to beta cell damage. To address this important issue, we submitted beta cells to a prolonged effect of increasing concentrations of insulin. We observed that a prolonged effect of high levels of insulin on the presence of serum (15–24h) in glucose-deprived beta cells induced apoptosis. This apoptotic effect was both dose- and cycloheximide-dependent

Rasmussen, Chenery and Watanabe, and labour-based multiplier analysis and sensitivity analysis of input coefficients for Spain in 2009

In this paper we identify the key sectors of the Spanish economy with the last input-output available data following the approaches by Rasmussen and by Chenery and Watanabe. We also calculate labour-based multipliers and sensitivity of input coefficients and we compare the results in order to present useful advice for sector policiesEn este trabajo analizamos cuáles son los sectores claves en España con los últimos datos publicados del marco input-output. Seguimos las metodologías de Rasmussen y de Chenery y Watanabe. También hacemos uso de los multiplicadores de remuneraciones, trabajadores y asalariados así como de la técnica de sensibilidad de coeficientes. En las conclusiones se presentan los principales hallazgos que permiten diseñar una política sectorial eficaz para Españ