The Diffuse Nature of Stromgren Spheres

In this Letter, we argue that the standard analytical derivations of properties of HII regions, such as the speed, shape and asymptotic position of ionisation fronts require a more precise treatment. These derivations use the on the spot approximation, which in effect ignores the diffuse component of the radiation field. We show that, in fact, HII regions are diffusion dominated. This has as a result that the morphology of inhomogeneous HII regions will be drastically different, because shadowing effects have a less profound impact on the apparent shape. Moreover, it will have influence on the propagation speed of ionisation fronts. We quantify our claims by analytically deriving the internal radiation structure of HII regions, taking diffusion fully into account for several different cosmologically relevant density distributions.Comment: 4 pages, 2 figures, accepted for publication in A&A Letter

Strength distribution of solar magnetic fields in photospheric quiet Sun regions

The magnetic topology of the solar photosphere in its quietest regions is hidden by the difficulties to disentangle magnetic flux through the resolution element from the field strength of unresolved structures. The observation of spectral lines with strong coupling with hyperfine structure, like the observed MnI line at 553.7 nm, allows such differentiation. The main aim is to analyse the distribution of field strengths in the network and intranetwork of the solar photosphere through inversion of the MnI line at 553.7 nm. An inversion code for the magnetic field using the Principal Component Analysis (PCA) has been developed. Statistical tests are run on the code to validate it. The code has to draw information from the small-amplitude spectral feature oppearing in the core of the Stokes V profile of the observed line for field strengths below a certain threshold, coinciding with lower limit of the Paschen-Back effect in the fine structure of the involved atomic levels. The inversion of the observed profiles, using the circular polarization (V) and the intensity (I), shows the presence of magnetic fields strengths in a range from 0 to 2 kG, with predominant weak strength values. Mixed regions with mean strength field values of 1130 and 435 Gauss are found associated with the network and intranetwork respectively. The MnI line at 553 nm probes the field strength distribution in the quiet sun and shows the predominance of weak, hectoGauss fields in the intranetwork, and strong, kiloGauss fields in the network. It also shows that both network and intranetwork are to be understood at our present spatial resolutions as field distributions of which we hint the mean properties.Comment: 10 pages, 6 figure

Physical activity practice and attitudes in canarian teenagers

En el presente estudio de la población adolescente de la Comunidad Autónoma de Canarias, se evidencia que aquellos adolescentes que cumplen con las recomendaciones de práctica de Actividad Física tanto de intensidad moderada como vigorosa frente a los que no las cumplen, muestran a su vez mejores valores en la percepción del conjunto de actitudes que influyen en los niveles de práctica; competencia motriz, disfrute y valor-utilidad otorgada a la misma. Lo cual nos permite afirmar que este conjunto de factores pueden determinar el tipo y grado de participación en actividades físico-deportivas en este sector de la poblaciónIn this actual study of the adolescent population of the Autonomous Region of the Canary Islands, is evident, that teens who comply with the recommendations of practice of physical activity both of moderate intensity as vigorous intensity, compared with those which do not comply, show the best values in the perception of the set of attitudes that influence the levels of practice; perceived competence, enjoyment, perceived value. Which allows us to affirm that this set of factors can determine the type and degree of participation in physical-sport activities in this sector of the populatio

Chemical Abundance Study of One Red Giant Star in NGC 5694 : A Globular Cluster with Dwarf Spheroidals' Chemical Signature?

We report the abundance analysis of one red giant branch star in the metal-poor outer halo globular cluster NGC 5694. We obtain [Fe/H] = -1.93, based on the ionized lines, and our metallicity measurement is in good agreement with previous estimates. We find that [Ca+Ti/2Fe] and [Cu/Fe] of NGC 5694 are about 0.3 -- 0.4 dex lower than other globular clusters with similar metallicities, but similar to some LMC clusters and stars in some dwarf spheroidal galaxies. Differences persist, however, in the abundances of neutron capture elements. The unique chemical abundance pattern and the large Galactocentric distance (30 kpc) and radial velocity (-138.6 +/- 1.0 km/sec) indicate that NGC 5694 had an extragalactic origin.Comment: ApJL accepte

Hardware-software co-design of an iris recognition algorithm

This paper describes the implementation of an iris recognition algorithm based on hardware-software co-design. The system architecture consists of a general-purpose 32- bit microprocessor and several slave coprocessors that accelerate the most intensive calculations. The whole iris recognition algorithm has been implemented on a low-cost Spartan 3 FPGA, achieving significant reduction in execution time when compared to a conventional software-based application. Experimental results show that with a clock speed of 40 MHz, an IrisCode is obtained in less than 523 ms from an image of 640x480 pixels, which is just 20% of the total time needed by a software solution running on the same microprocessor embedded in the architecture.Peer ReviewedPreprin

Estilos de trabajo e inteligencias múltiples

El objetivo del trabajo es determinarla validez yflabilidad del modelo dejos estilos de trabajo, fundamentado en la teoría de las Inteligencias Múltiples (IM). Primero, se analizan los componentes de dicha teoría y su incidencia en el curriculum escolar. En segundo lugar, se estudia el procedimiento de evaluación. Además, se presentan los resultados del estudio empírico realizado con una muestra de 237 alumnos pertenecientes a Educación Infantil y Primaria, escolarizados en centros públicos y privados de la Región de Murcia. Del estudio realizado se desprende que los estilos están asociados a las diferentes inteligencias; además, el inventario de estilos de trabajo arroja una validez y fiabilidad altamente consistente.________________________________ The objective of this work is to determinate the validity and reliability of the model of work styles, as set out In the theory of Multiple Intelligences (MI). First, we analyze the components of this theory and their Incidence in the school curriculum. Second, we study the evaluation procedure. Additionally, we present the results of an empirical study carried out with a sample of 237 students in public and private nursery and primary schools in the province of Murcia, Spain. The study carried out reveals that the styles are associated with the different Intelligences. Furthermore, the inventory of styles shows a highly consistent validity and reliability

On the classification and properties of noncommutative duplicates

We give an explicit description of the set of all factorization structures, or twisting maps, existing between the algebras k^2 and k^2, and classify the resulting algebras up to isomorphism. In the process we relate several different approaches formerly taken to deal with this problem, filling a gap that appeared in a recent paper by Cibils. We also provide a counterexample to a result concerning the Hochschild (co)homology appeared in a paper by J.A. Guccione and J.J. Guccione.Comment: 11 pages, no figure