Asymmetric I-V characteristics and magnetoresistance in magnetic point contacts

We present a theoretical study of the transport properties of magnetic point contacts under bias. Our calculations are based on the Keldish's non-equilibrium Green's function formalism combined with a self-consistent empirical tight-binding Hamiltonian, which describes both strong ferromagnetism and charging effects. We demonstrate that large magnetoresistance solely due to electronic effects can be found when a sharp domain wall forms inside a magnetic atomic-scale point contact. Moreover we show that the symmetry of the $I$-$V$ characteristic depends on the position of the domain wall in the constriction. In particular diode-like curves can arise when the domain wall is placed off-center within the point contact, although the whole structure does not present any structural asymmetry.Comment: 7 figures, submitted to PR

Estrategias de cooperación inter-empresa para el desarrollo de mejores prácticas medioambientales en la industria de los astilleros colombianos

The present work aims to develop strategies that allow implementingenvironmental best practices in the Colombian shipyard industry, a sector that has been growing for the last decade and that is identified as a potential world-class industry in the country. Collaborative work was carried out with four of the biggest Colombian shipyards and an international firm to identify legal and operational issues regarding the industrial activity, to reach unified consensus to represent the whole sector. Finally, an environmentalbest practices document was elaborated to guideshipyard operationsin the country, with the potential to be constituted as an official guide of the Colombian Ministry for the Environment.El presente trabajo tiene como objetivo desarrollar estrategias que permitan incorporar buenas prácticasambientales en la industria astillera Colombiana, sector que ha mostrado un crecimiento significativo en la última década y que representa una apuesta productiva para el país. Se efectuó un trabajo colaborativo con cuatro de los astilleros más representativos en el país y una empresa internacional para identificar los aspectos legales y de operación de la actividad industrial que impactan el medio ambiente, de manera que se lograse unificar criterios que tuviesen una representatividad sectorial. Finalmente se consolidóun documento de buenas prácticas ambientales para orientar la operación de astilleros en el país, con el potencial de constituirse como una guía oficial del Ministerio de Ambiente, Vivienda y Desarrollo Territorial colombiano

DON BENITO PÉREZ GALDÓS [Material gráfico]

Copia digital. Madrid : Ministerio de Educación, Cultura y Deporte. Subdirección General de Coordinación Bibliotecaria, 201

IL-17A and Streptococcus pneumoniae respiratory infection: Prospects for the development of new immunotherapies

Nasopharyngeal colonization by Streptococcus pneumoniae constitutes a pre-requisite for development of pneumonia and invasive pneumococcal diseases. Colonization is typically asymptomatic and is resolved due to a dynamic and complex interplay between microbiota, host immune system and environmental factors. Working with a murine model of pneumococcal nasopharyngeal colonization, we have shown that IL-17A is a key cytokine in this process, since Il17a-/- mice were persistently colonized for up to 6 months whereas wild type mice cleared colonization in 10 days. We are currently trying to elucidate the downstream mechanisms that may account for the phenotype showed in Il17a-/- mice, including the production of specific antibodies, as well as the recruitment of innate cells and the expression of immune mediators in WT and Il17a-/- mice. On the other hand, we have studied the role of IL-17A in the development of protective immunity against acute pneumococcal pneumonia. Previously, we showed that prior sublethal infection resulted in solid protection against invasive pneumonia which is associated with over expression of IL-17A together with the presence of Th17 cells in the lungs. However, Il17a-/- mice showed same level of protection than WT, demonstrating that IL-17A by itself is not essential for protective immunity. Interestingly Il17a-/- mice showed overexpression of other IL-17 related genes suggesting a complex network where compensatory effects may be occurring. Finally, we have developed and tested alternative immunotherapies against pneumococcal pneumonia, and have evaluated the role of IL17A in the protection afforded. Overall, we believe that deciphering the molecular basis of protective immunity will result in the development of new cost-effective immunotherapies against pneumococcal pneumonia

Versalhes Redimido?

Os devastadores conflitos que acompanharam a desagregação dos estados multinacionais comunistas na década de 90 estiveram na base das muitas análises que traçaram um paralelo entre duas transições de ordens internacionais: a de 1919 e a de 1989-91. Em ambos os casos, a cultura política das elites envolvidas na criação de novos estados independentes haveria de revelar-se altamente nociva para a constituição de uma ordem política mais liberal no espaço dos antigos impérios. A grande diferença é que, pelo menos, a ordem de Versalhes possuía uma doutrina consistente para lidar com o desafio do nacionalismo étnico, a qual assumiu a forma de um regime internacional de protecção das minorias, garantido pela SDN. Daí, talvez, a tendência recente para a reabilitação do Acordo de Versalhes, depois de durante décadas este ter sido alvo de uma persistente difamação por parte da historiografia internacional

Monitoreo Externo al Proceso de Implementación del Programa del Teletrabajo para la Población en Condición de Discapacidad Visual: Estudio de Caso en el Instituto Distrital de Recreación y Deporte

Monitorear externamente el proceso de implementación del Programa del Teletrabajo de la Política Pública de Gestión Integral del Talento Humano Distrital, adaptando el monitoring goverment policy toolkit, concretamente, al beneficio selectivo de priorización para la población en condición de discapacidad visual mediante estudio de caso en el Instituto Distrital de Recreación y Deporte, con el fin de generar aportes/recomendaciones para el reconocimiento del enfoque de acción sin daño en la implementación de la modalidad.El presente documento trata sobre la implementación de la Política Pública para la Gestión Integral del Talento Humano Distrital, PPGITHD, vigencia 2020-2030, en lo referente al beneficio selectivo de priorización en el Programa del Teletrabajo en los organismos y entidades públicas del Distrito Capital. Concretamente, en el monitoreo externo al proceso de implementación de la modalidad de organización e inclusión laboral del teletrabajo por parte del Instituto Distrital de Recreación y Deporte para el segmento de población con discapacidad visual—Artículo 3º, criterios de prioridad, del Decreto Distrital 806 de 2019 emitido por la Alcaldía Mayor de Bogotá, D.C. El estudio de corte exploratorio-descriptivo pretende generar aportes/recomendaciones para el reconocimiento del enfoque de la acción sin daño en los procesos de formación e implementación de los beneficios selectivos en las Políticas Públicas dirigidas al talento humano de los organismos y entidades públicas del Distrito Capital.This document exposes the implementation of the Public Policy to the human resources of Colombia Capital District, PPGITHD 2020-2030, in relation to the selective benefit of prioritization in the Teleworking Program of the public organizations. In particular, in the process implementation external monitoring of the organization’s modality and labor inclusion of teleworking by the District Institute of Recreation and Sports for the people with visual impairments. This descriptive study aims to generate recommendations for the recognition of the approach to do no harm action in the planning processes and implementation of selective benefits in public policies to talent management of the public entities of the Capital District

Monitoreo Externo al Proceso de Implementación del Programa del Teletrabajo para la Población en Condición de Discapacidad Visual: Estudio de Caso en el Instituto Distrital de Recreación y Deporte

Monitorear externamente el proceso de implementación del Programa del Teletrabajo de la Política Pública de Gestión Integral del Talento Humano Distrital, adaptando el monitoring goverment policy toolkit, concretamente, al beneficio selectivo de priorización para la población en condición de discapacidad visual mediante estudio de caso en el Instituto Distrital de Recreación y Deporte, con el fin de generar aportes/recomendaciones para el reconocimiento del enfoque de acción sin daño en la implementación de la modalidad.El presente documento trata sobre la implementación de la Política Pública para la Gestión Integral del Talento Humano Distrital, PPGITHD, vigencia 2020-2030, en lo referente al beneficio selectivo de priorización en el Programa del Teletrabajo en los organismos y entidades públicas del Distrito Capital. Concretamente, en el monitoreo externo al proceso de implementación de la modalidad de organización e inclusión laboral del teletrabajo por parte del Instituto Distrital de Recreación y Deporte para el segmento de población con discapacidad visual—Artículo 3º, criterios de prioridad, del Decreto Distrital 806 de 2019 emitido por la Alcaldía Mayor de Bogotá, D.C. El estudio de corte exploratorio-descriptivo pretende generar aportes/recomendaciones para el reconocimiento del enfoque de la acción sin daño en los procesos de formación e implementación de los beneficios selectivos en las Políticas Públicas dirigidas al talento humano de los organismos y entidades públicas del Distrito Capital.This document exposes the implementation of the Public Policy to the human resources of Colombia Capital District, PPGITHD 2020-2030, in relation to the selective benefit of prioritization in the Teleworking Program of the public organizations. In particular, in the process implementation external monitoring of the organization’s modality and labor inclusion of teleworking by the District Institute of Recreation and Sports for the people with visual impairments. This descriptive study aims to generate recommendations for the recognition of the approach to do no harm action in the planning processes and implementation of selective benefits in public policies to talent management of the public entities of the Capital District

Mechanisms of refractive index modification during femtosecond laser writing of waveguides in alkaline lead-oxide silicate glass

3 pages, 3 figures.We report on the mechanisms responsible for the formation of optical waveguides upon femtosecond laser irradiation of an alkaline lead-oxide silicate glass. MicroRaman spectroscopy and nonlinear fluorescence were employed to probe the local glass network structure and the formation of optically active defects respectively. At low laser pulse energies, the laser modified region is formed by a single light guiding region, whereas for pulses above 14 µJ the modified region is formed by a central dark zone, which does not guide light, accompanied by light guiding zones located in the surrounding of the dark one. This behavior is different from that observed in common silica glass systems but agrees with recent results obtained in phosphate and heavy metal oxide glasses. However, our results show that, unlike the latter glass, local densification of the glass occurs in the whole laser modified region, i.e., in the dark and the guiding zones. The suppression of light guiding in the dark region is explained by a high density of absorbing color centers.This work was partially supported by CICYT (Spain) under Project No. DPI2002-00151. One of the authors (V.D.B.) acknowledges the financial support of the CSIC and the European Social Fund through an I3P Ph.D. fellowship. Another author (P.L.-A. acknowledges funding from the Spanish Government ( the Ramón y Cajal program and Grant No. TIC2003-07485).Peer reviewe

In situ assessment and minimization of nonlinear propagation effects for femtosecond-laser waveguide writing in dielectrics

The effect of nonlinear propagation on the shape of the focal volume has been assessed by in situ plasma emission imaging during the subsurface processing of a commercial phosphate glass. The sample was processed with an elliptically shaped femtosecond-laser beam at 1 kHz repetition rate and scanned transversely with respect to the writing beam axis. As a consequence, optimal conditions for minimizing undesirable nonlinear propagation effects during the production of optical waveguides by direct laser writing have been determined. Under these conditions, it is possible to induce structural transformations and still preserve the focal volume shape associated with the linear propagation regime. While at low pulse energy a single scan laser-written structure does not support a guided mode, the use of multiple scans with minimized nonlinear propagation effects enables the production of optical waveguides. The latter show a significantly improved performance in terms of the refractive index change and propagation losses when compared to single scan waveguides. © 2010 Optical Society of America.This work was partially supported by the University of Zaragoza under Project 223/88 and by the Spanish Ministry of Science and Innovation under TEC2008-01183 project. A. Ruiz de la Cruz and W. Gawelda acknowledge their I3P-CSIC postdoctoral contracts (co-funded by the European Social Fund). D. Puerto and A. Ferrer acknowledge their grants under Projects TEC 2005-00074 and TEC 2006-04538.Peer Reviewe