Electric and magnetic dipolar response of Germanium spheres: Interference effects, scattering anisotropy and optical forces

We address the scattering cross sections, and their consequences, for submicrometer Germanium spheres. It is shown that there is a wide window in the near infrared where light scattering by these particles is fully described by their induced electric and magnetic dipoles. In this way, we observe remarkable anisotropic scattering angular distributions, as well as zero forward or backward scattered intensities, which until recently was theoretically demonstrated only for hypothetically postulated magnetodielectric spheres. Also, interesting new effects of the optical forces exerted on these objects are now obtained.Comment: 13 pages, 4 figure

IAA : Información y actualidad astronómica (32)

Sumario : El laboratorio de polvo cósmico del IAA ...2 La interminable historia del agua en la Luna ...6 Multiversos y cómics ...9 HISTORIAS DE ASTRONOMÍA. Caroline Herschel ...13 DECONSTRUCCIÓN Y otros ENSAYOS. Zoom al centro galáctico ...14 EL “MOBY DICK” DE... Marta González (IAA-CSIC)...16 ACTUALIDAD ...17 ENTRE BASTIDORES ...21 CIENCIA: PILARES E INCERTIDUMBRES Tormentas solares ...22 ACTIVIDADES IAA, AGENDA Y RECOMENDADOS ...23 y 24N

Murine muscle engineered from dermal precursors: an in vitro model for skeletal muscle generation, degeneration and fatty infiltration.

Skeletal muscle can be engineered by converting dermal precursors into muscle progenitors and differentiated myocytes. However, the efficiency of muscle development remains relatively low and it is currently unclear if this is due to poor characterization of the myogenic precursors, the protocols used for cell differentiation, or a combination of both. In this study, we characterized myogenic precursors present in murine dermospheres, and evaluated mature myotubes grown in a novel three-dimensional culture system. After 57 days of differentiation, we observed isolated, twitching myotubes followed by spontaneous contractions of the entire tissue-engineered muscle construct on an extracellular matrix (ECM). In vitro engineered myofibers expressed canonical muscle markers and exhibited a skeletal (not cardiac) muscle ultrastructure, with numerous striations and the presence of aligned, enlarged mitochondria, intertwined with sarcoplasmic reticula (SR). Engineered myofibers exhibited Na+- and Ca2+-dependent inward currents upon acetylcholine (ACh) stimulation and tetrodotoxin-sensitive spontaneous action potentials. Moreover, ACh, nicotine, and caffeine elicited cytosolic Ca2+ transients; fiber contractions coupled to these Ca2+ transients suggest that Ca2+ entry is activating calcium-induced calcium release from the SR. Blockade by d-tubocurarine of ACh-elicited inward currents and Ca2+ transients suggests nicotinic receptor involvement. Interestingly, after 1 month, engineered muscle constructs showed progressive degradation of the myofibers concomitant with fatty infiltration, paralleling the natural course of muscular degeneration. We conclude that mature myofibers may be differentiated on the ECM from myogenic precursor cells present in murine dermospheres, in an in vitro system that mimics some characteristics found in aging and muscular degeneration

IAA : Información y actualidad astronómica (26)

Sumario : Estrellas de neutrones: furioso magnetismo.-- La astronomía en el arte.-- DECONSTRUCCIÓN Y otros ENSAYOS : Lo más frío del Universo.-- CIENCIA: PILARES E INCERTIDUMBRES : Los meteoritos “ordinarios”.-- ACTUALIDAD.-- ENTRE BASTIDORES : Las generaciones perdidas.-- HISTORIAS DE ASTRONOMÍA : El organista que descubrió Urano.-- ACTIVIDADES IAA.Esta revista se publica con la ayuda FCT-08-0130 del Programa Nacional de Fomento de la Cultura Científica y Tecnológica 2008.N

Zone design of specific sizes using adaptive additively weighted voronoi diagrams

Territory or zone design processes entail partitioning a geographic space, organized as a set of areal units, into different regions or zones according to a specific set of criteria that are dependent on the application context. In most cases, the aim is to create zones of approximately equal sizes (zones with equal numbers of inhabitants, same average sales, etc.). However, some of the new applications that have emerged, particularly in the context of sustainable development policies, are aimed at defining zones of a predetermined, though not necessarily similar, size. In addition, the zones should be built around a given set of seeds. This type of partitioning has not been sufficiently researched; therefore, there are no known approaches for automated zone delimitation. This study proposes a new method based on a discrete version of the adaptive additively weighted Voronoi diagram that makes it possible to partition a two-dimensional space into zones of specific sizes, taking both the position and the weight of each seed into account. The method consists of repeatedly solving a traditional additively weighted Voronoi diagram, so that each seed?s weight is updated at every iteration. The zones are geographically connected using a metric based on the shortest path. Tests conducted on the extensive farming system of three municipalities in Castile-La Mancha (Spain) have established that the proposed heuristic procedure is valid for solving this type of partitioning problem. Nevertheless, these tests confirmed that the given seed position determines the spatial configuration the method must solve and this may have a great impact on the resulting partition

IAA : Información y actualidad astronómica (33)

Sumario : Las estrellas jóvenes “imitan” a los agujeros negros.-- La Nebulosa de la Pipa.-- Galaxias “guisante verde”.-- HISTORIAS DE ASTRONOMÍA. Palomas y elefantes.-- DECONSTRUCCIÓN Y otros ENSAYOS. Misión Sunrise.-- EL “MOBY DICK” DE... Martín Guerrero Roncel (IAA-CSIC).-- ACTUALIDAD.-- ENTRE BASTIDORES.-- CIENCIA: PILARES E INCERTIDUMBRES : Agujeros negros.-- ACTIVIDADES IAA, AGENDA Y RECOMENDADOS.N

IAA : Información y actualidad astronómica (22)

Sumario : Estrellas binarias: un matrimonio muy ventajoso.-- Mujeres y ciencia: rompiendo techos.-- La estrella más masiva.-- DECONSTRUCCIÓN Y otros ENSAYOS : Criterios termodinámicos en la evolución de agujeros negros.-- ACTUALIDAD.-- ENTRE BASTIDORES.-- CIENCIA: PILARES E INCERTIDUMBRES. Núcleos de galaxias activas .-- HISTORIAS DE ASTRONOMÍA: “Serendipia” cósmica.-- El increíble y asombroso viaje de Fotón. II Parte.-- ACTIVIDADES IAA.Esta revista se publica con la ayuda de la Acción Complementaria CCT005-06-00178 del Programa Nacional de Fomento de la Cultura Científica y Tecnológica.N

IAA : Información y actualidad astronómica (24)

Sumario : Máseres en el espacio.-- Venus Express.-- El complejo cinturón de asteroides.-- DECONSTRUCCIÓN Y otros ENSAYOS : Rotación diferencial y oscilaciones estelares.-- ACTUALIDAD.-- ENTRE BASTIDORES .-- HISTORIAS DE ASTRONOMÍA: El astrónomo de vista prodigiosa.-- CIENCIA: PILARES E INCERTIDUMBRES : Ondas gravitatorias.-- ACTIVIDADES IAA.Esta revista se publica con la ayuda FCT-08-0130 del Programa Nacional de Fomento de la Cultura Científica y Tecnológica 2008.N

Adolescents and young adults evaluating a website for affective‐sexual information and education: a mixed‐methods study protocol

The website Sexe Joves is a website on sexuality of the Department of Health of the Government of Catalonia (Spain). This study aims to understand the experiences and opinions of people aged 14 to 25 regarding this website, taking into account sex, gender identity, sexual orientation, socioeconomic status and location within Catalonia (urban, semiurban and rural areas). With the objective of improving the website and adpating the resources allocated to it, this study evaluates whether this population is familiar with it and uses it, as well as the website's usability and accessibility (digital equity), usefulness and the relevance of its content. A parallel convergent triangulation design is used: a qualitative study using a social constructivist perspective, and an observational, descriptive and cross-sectional quantitative study. We conduct a discourse analysis of participants and use an 'ad hoc' questionnaire to collect quantitative data. A descriptive analysis of all variables is carried out. Affective-sexual education aimed at young people must stem from their participation and the whole range of sexual and gender diversity in order to reach the entire population equally. This analysis will contribute to the design of new strategies for the wesbite Sexe Joves, a public health resource, in order to improve affective-sexual education for young people