Mechanisms for photon sorting based on slit-groove arrays

Mechanisms for one-dimensional photon sorting are theoretically studied in the framework of a couple mode method. The considered system is a nanopatterned structure composed of two different pixels drilled on the surface of a thin gold layer. Each pixel consists of a slit-groove array designed to squeeze a large fraction of the incident light into the central slit. The Double-Pixel is optimized to resolve two different frequencies in the near infrared. This system shows a high transmission efficiency and a small crosstalk. Its response is found to strongly depend on the effective area shared by overlapping pixels. Three different regimes for the process of photon sorting are identified and the main physical trends underneath in such regimes are unveiled. Optimal efficiencies for the photon sorting are obtained for a moderate number of grooves that overlap with grooves of the neighbor pixel. Results could be applied to optical and infrared detectors.Comment: 12 pages, 4 figure

Transmittance of a subwavelength aperture flanked by a finite groove array \\ placed near the focus of a conventional lens

One-dimensional light harvesting structures illuminated by a conventional lens are studied in this paper. Our theoretical study shows that high transmission efficiencies are obtained when the structure is placed near the focal plane of the lens. The considered structure is a finite slit-groove array (SGA) with a given number of grooves that are symmetrically distributed with respect to a central slit. The SGA is nano-patterned on an opaque metallic film. It is found that a total transmittance of 80% is achieved even for a single slit when (i) Fabry-Perot like modes are excited inside the slit and (ii) the effective cross section of the aperture becomes of the order of the full width at half maximum of the incident beam. A further enhancement of 8% is produced by the groove array. The optimal geometry for the groove array consists of a moderate number of grooves ($\geq 4$) at either side of the slit, separated by a distance of half the incident wavelength $\lambda$. Grooves should be deeper (with depth $\geq \lambda/4$) than those typically reported for plane wave illumination in order to increase their individual scattering cross section.Comment: 7 pages, 6 figure

Educating for participation from a planetary perspective. Analysis of educational experiences in Andalusia

Las finalidades básicas de la Educación Ambiental y de la Educación para la Ciudadanía pueden confluir en una perspectiva de “educación ciudadana planetaria”, que tenga como eje central la educación para la participación como ciudadanos en relación con los problemas sociales y ambientales, a escala local y a escala global. Desde este marco se analizan varios programas de educación para la participación ciudadana desarrollados en Andalucía: “Ecoescuela”, “Parlamento Joven” y “Seguro que te mueves”, valorando sus potencialidades y sus dificultades, con especial atención a las concepciones del profesorado y del alumnado implicados en los mismos.The basic aims of Environmental Education and Education for Citizenship can converge in a perspective of “global citizenship education”, which has as its central axis education for participation as citizens in relation to social and environmental issues, in a local and global scale. From this framework several education programs for citizen participation developed in Andalusia are analyzed: “Eco-School”, “Youths’ Parliament” and “Sure You Move”, assessing their strengths and their difficulties, with particular attention to the conceptions of teachers and students involved therein

Environment and citizenship: Education for the participation as a base for a global citizenship education

Ciudadanía y medio ambiente se plantean como dos de los grandes retos a abordar en el siglo XXI en el ámbito de la educación. Esta investigación pretende aportar resultados acerca de la relevancia que los programas de participación ciudadana tienen en el alumnado en orden a fomentar las competencias relacionadas con la ciudadanía activa. Proponemos un marco teórico conjunto de la educación ambiental y la educación para la ciudadanía asumiendo una perspectiva de educación ciudadana planetaria o educación global. La investigación se desarrolla sobre varios casos de programas de educación para la participación ciudadana (Ecoescuela, Parlamento joven, Seguro que te mueves) en Andalucía y utiliza una metodología cualitativa de triangulación de datos con cuestionarios, entrevistas y grupos de discusión, utilizándose el software Atlas.ti para el tratamiento de los datos. Pretendemos así identificar las potencialidades y limitaciones de dichos programas, que han ido surgiendo de la necesidad de dar respuesta a valores considerados como deseables para la ciudadanía del siglo XXI. Entre los resultados obtenidos destacamos la potencialidad de estos programas educativos para formar ciudadanos comprometidos con los problemas sociales y ambientales desde una perspectiva de ciudadanía planetaria.Citizenship and environment are presented as two of the big challenges to be faced in the 21st century in the area of education. This research aims to provide results about the relevance that citizen participation programs have on students in order to foster the skills related to active citizenship. A theoretical framework of environmental education and education for citizenship is set assuming a perspective of planetary or global citizenship education. The research is based on several cases of education programs for citizen participation (Eco-Shool, Parlamento Joven, Seguro que te mueves) in Andalusia and uses a qualitative methodology of triangulation data through questionnaires, interviews and focus groups, using the software Atlas.ti for the data processing. We intend to identify the potentials and limitations of these programs, which have arisen from the need to provide responses to what are considered desirable values for 21st century citizenship. Among the results we highlight the potential of these educational programs to educate citizens involved in social and environmental problems from the perspective of global citizenship.Ministerio de Educación y Ciencia y por Fondos FEDE

Escuela y desarrollo comunitario: educación ambiental y ciudadanía en las aulas de secundaria

La finalidad básica de la investigación que aquí se presenta es analizar la potencialidad educativa del programa Seguro que te mueves, cuyo objetivo es favorecer la participación activa del alumnado en su entorno inmediato, generando actitudes de compromiso con las problemáticas de su localidad. Se han analizado las propuestas llevadas a cabo en dos institutos de enseñanza secundaria de la provincia de Sevilla (España). Para el análisis se ha diseñado una metodología de carácter cualitativo que ha permitido establecer las dificultades pero, sobre todo, las posibilidades del programa para construir un modelo deseable de ciudadanía participativa y comprometida con el entorno. En cuanto a las conclusiones, se percibe una carencia de actividades específicas que permitan entender las cuestiones detectadas desde un enfoque más amplio, conectando así los problemas locales con los globales.The basic end of the research presented in this article is to analyze the educational potential of the “Move Already!” program, which is aimed at encouraging students’ active participation in their immediate surroundings, while generating attitudes of commitment toward local problems. An analysis was made of the actions carried out in two secondary schools in Seville, Spain. Qualitative methodology has allowed a definition of difficulties, as well as a program’s possibilities in constructing a desirable model of participative citizens committed to their environment. In conclusion, a lack of specific activities prevents understanding issues from a broader perspective that would connect local and global problems

Mechanisms for photon sorting based on slit-groove arrays

Mechanisms for one-dimensional photon sorting are theoretically studied in the framework of a coupled-mode method. The considered system is a nanopatterned structure composed of two different pixels drilled on the surface of a thin gold layer. Each pixel consists of a slit-groove array designed to squeeze a large fraction of the incident light into the central slit. The Double-Pixel is optimized to resolve two different frequencies in the near infrared. This system shows high transmission efficiencies and a small crosstalk. It is found that the response of the system strongly depends on the effective area shared by overlapping pixels. According to such degree of overlap, photon sorting can be achieved within three different regimes, which are discussed in detail. Optimal photon-sorting efficiencies are obtained for a moderate number of grooves that overlap with grooves of the neighbor pixel. These results could be applied to both optical and infrared detectors.The authors gratefully acknowledge financial support by European Projects EC FP7-ICT PLAISIR Project Ref. 247991, the Spanish Ministry of Science and Innovation project MAT2011-28581-C02-02, and the CUD project Ref. 2013-13.Peer Reviewe

Tau Phosphorylation, Aggregation, and Cell Toxicity

Protein aggregation takes place in many neurodegenerative disorders. However, there is a controversy about the possible toxicity of these protein aggregates. In this review, this controversy is discussed, focussing on the tau aggregation that takes place in those disorders known as tauopathies

Researching the crisis

La crisis es un problema que afecta y preocupa a todas las personas, también al alumnado. Este problema puede ser trabajado y aprendido de forma significativa con una metodología de investigación escolar, que tiene en cuenta la aportación de los contenidos disciplinares, la significación para el alumnado y la relevancia del problema social. Desde estas bases, se muestra el diseño y la puesta en práctica de una unidad didáctica sobre la crisis, siguiendo un modelo de investigación escolar. Los contenidos trabajados en esta unidad permiten la integración de las distintas áreas curriculares y favorecen el logro de las competencias básicas.The crisis is a problem that affects and concerns all people, including the students. This problem can be worked with and learned significantly with school research methodology, which takes into account the contribution of the disciplinary content, the significance for students and the relevance of the social problem. From these bases, we show the design and implementation of a didactic unit on the crisis, following a model of school research. The contents worked in this unit allow the integration of curricular areas and promote the achievement of basic skill