The stellar host in star-forming low-mass galaxies: Evidence for two classes

The morphological evolution of star-forming galaxies provides important clues to understand their physical properties, as well as the triggering and quenching mechanisms of star formation. We aim at connecting morphology and star-formation properties of low-mass galaxies (median stellar mass $\sim$ 10$^{8.5}$ M$_{\odot}$) at low redshift ($z<0.36$). We use a sample of medium-band selected star-forming galaxies from the GOODS-North field. H$\alpha$ images for the sample are created combining both spectral energy distribution fits and HST data. Using them, we mask the star forming regions to obtain an unbiased two-dimensional model of the light distribution of the host galaxies. For this purpose we use $\texttt{PHI}$, a new Bayesian photometric decomposition code. We apply it independently to 7 HST bands assuming a S\'ersic surface brightness model. Star-forming galaxy hosts show low S\'ersic index (with median $n$ $\sim$ 0.9), as well as small sizes (median $R_e$ $\sim$ 1.6 kpc), and negligible change of the parameters with wavelength (except for the axis ratio, which grows with wavelength). Using a clustering algorithm, we find two different classes of star-forming galaxies: A more compact, redder, and high-$n$ (class A) and a more extended, bluer and lower-$n$ one (class B). We also find evidence that the first class is more spheroidal-like. In addition, we find that 48% of the analyzed galaxies present negative color gradients (only 5% are positive). The host component of low-mass star-forming galaxies at $z<0.36$ separates into two different classes, similar to what has been found for their higher mass counterparts. The results are consistent with an evolution from class B to class A. Several mechanisms from the literature, like minor and major mergers, and violent disk instability, can explain the physical process behind the likely transition between the classes. [abridged]Comment: Accepted for publication in Astronomy & Astrophysics. 13 pages, 11 figure

Levels, sources and seasonality of coarse particles (PM10-PM2.5) in three European capitals e implications for particulate pollution control

Coarse particles of aerodynamic diameter between 2.5 and 10 mm (PMc) are produced by a range of natural (windblown dust and sea sprays) and anthropogenic processes (non-exhaust vehicle emissions, industrial, agriculture, construction and quarrying activities). Although current ambient air quality regulations focus on PM2.5 and PM10, coarse particles are of interest from a public health point of view as they have been associated with certain mortality and morbidity outcomes. In this paper, an analysis of coarse particle levels in three European capitals (London, Madrid and Athens) is presented and discussed. For all three cities we analysed data from both traffic and urban background monitoring sites. The results showed that the levels of coarse particles present significant seasonal, weekly and daily variability. Their wind driven and non-wind driven resuspension as well as their roadside increment due to traffic were estimated. Both the local meteorological conditions and the air mass history indicating long-range atmospheric transport of particles of natural origin are significant parameters that influence the levels of coarse particles in the three cities especially during episodic events

Els fars davanters a ull de càmara

La contínua innovació en els sistemes d'il·luminació dels automòbils comporta també una millora en els sistemes d'avaluació. Aquests estan basats en la comparació dinàmica, és a dir, que siguin els propis experts o usuaris qui comprovin la qualitat dels fars durant una sèrie de proves de conducció. L'inconvenient d'aquesta mena d'avaluació és que resulta força costós, i la capacitat de retenció visual a curt termini de les persones no assegura uns resultats definitius. Per això, el departament de Desenvolupament Elèctric, Il·luminació i Senyalització del Centre Tècnic de SEAT, a Martorell, i el Centre de Visió per Computador de la UAB han ideat un sistema de gravació, del que després es podran visionar els fotogrames i fer-ne la comparació. És necessari però, sincronització i alineació espacial entre els fotogrames per ajustar correctament els resultats a la realitat de la conducció.La continua innovación en los sistemas de iluminación de los automóviles comporta también una mejora en los sistemas de evaluación. Éstos están basados en la comparación dinámica, es decir, que sean los propios expertos o usuarios quienes comprueben la calidad de los faros durante una serie de pruebas de conducción. El inconveniente de este tipo de evaluación es que resulta bastante costoso, y la capacidad de retención visual a corto plazo de las personas no asegura unos resultados definitivos. Por eso, el departamento de Desarrollo Eléctrico, Iluminación y Señalización del Centro Técnico de SEAT, en Martorell, i el Centro de Visión por Computador de la UAB han ideado un sistema de grabación, del que después se podrán visionar los videos y realizar la comparación. Es necesario sin embargo, sincronización y alineación espacial entre los fotogramas para ajustar correctamente los resultados a la realidad de la conducción.Continuous innovation in headlamp systems also implies an improvement in how they are assessed. These assessment systems are based on dynamic comparison, i.e., experts or users themselves assess the quality of headlamps by means of different driving tests. The disadvantages of this type of assessment are the elevated cost and the fact that short-term visual retention does not guarantee definitive results. For this reason, the Department of Electrical, Lighting and Signal Development at SEAT's Technical Centre in Martorell, and Computer Vision Centre of UAB have created a recording system. The frames from these recordings will later be viewed and compared. However, first they will have to be spatially synchronised and aligned in order to adjust the results to real driving situations

DISTRIBUCIÓN DE ALGUNOS TAXONES (AQUIFOLIACEAE, SAXIFRAGACEAE, ROSACEAE, TAXACEAE), EN LA PROVINCIA DE CASTELLÓN (ESPAÑA)

A great population of Taxus baccata L. and other interesting taxa such as Ilex aquifolium L., and Saxifraga granulata L., has been found in the Sierra Espadán (Castellón) where these species were hardly known or not known at all.Se ha encontrado una importante población de Taxus baccata L. y otros taxones interesantes como Ilex aquifolium L., y Saxifraga granulata L., en la Sierra de Espadán (Castellón) donde estas especies eran escasamente conocidas

Estoque de carbono em solos de uma área de expansão do Projeto Jaíba, no norte de Minas Gerais.

Com a expansão do Projeto Jaíba e a entrada da irrigação em novas áreas, ocasionando avanço no desmatamento e nas mudanças de uso das terras, é fundamental que se conheçam características relacionadas à qualidade do solo a fim de evitar sua degradação. Nesse contexto, o objetivo deste estudo foi avaliar o estoque de carbono no solo em uma das áreas de expansão do Projeto Jaíba. O ECS foi calculado por horizonte, até 100 cm, para 9 perfis de solos: Chernossolo Rêndzico (J16); Cambissolos Háplicos (J13 e J19), Gleissolo Háplico (J20) e Neossolo Flúvico (J17); Latossolos Amarelos (J11 e J21), Neossolo Quartzarênico (J15) e Planossolo Háplico (J14). Os ECS foram variáveis entre os solos e agrupados em 3 níveis de acordo com o conteúdo de carbono: G1 (Chernossolo), com o maior valor de ECS, 111,8 Mg ha-1, seguido pelo G2 (Cambissolos, Gleissolo, Neossolo Fúvico), variando de 55,2 a 72,1 Mg ha-1 e G3 (Planossolo, Latossolos e Neossolo Quartzarênico), com 25,0 a 44,6 Mg ha-1 de carbono. A posição dos solos na paisagem e suas características físico-químicas parecem ser os principais fatores responsáveis pela variação nos estoques de carbono entre os solos estudados. O conhecimento do ECS da área irá contribuir para a orientação do uso e manejo dos solos, a fim de favorecer mecanismos de acúmulo de carbono orgânico, em especial para os Latossolos, que ocorrem em maior proporção na área, são os mais propícios à utilização de sistemas de irrigação

Generic competences for the IT knowledge workers: a study from the field.

Proceedings of: Third World Summit on the Knowledge Society (WSKS 2010), Corfu, Greece, September 22-24, 2010This paper aims to identify generic competency levels relevant to a particular kind of knowledge workers: software engineers. Based on previous works, and in particular in the description of a professional career, authors review of the literature related to the characterization of the labor force in the Software Engineering (SE) domain. Subsequently, using a quantitative analysis based on investigative surveys administered to a number of representative professionals, authors provide with a generic competency ladder adapted to the given career description.Publicad