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

Estoques de Carbono Orgânico em Solos do Corredor de Nacala, Moçambique.

Apoiado por cooperações internacionais, Moçambique tem buscado desenvolver uma agricultura sustentável e auto - suficiente em alimentos. O objetivo deste trabalho foi avaliar estoques de carbono e suas implicações em solos de uma área piloto do Corredor de Nacala, em Moçambique. Em amostras de oito perfis de solo foram determinadas características físicas, químicas, COT e calculado o estoque de carbono do solo (ECS) para horizontes e camadas de 0 - 30 e 0 - 100 cm. Os teores de COT foram baixos e o ECS não diferiu para classes de solo e condições de drenagem. O ECS da camada de 0 - 30 cm representou mais de 50% do estoque da camada de 0 - 100 cm. A adoção de práticas conservacionistasde manejo do solo, como o abandono da queima deresíduos, redução da mobilização do solo e uso de plantas de cobertura com alta produção de resíduos são recomendáveis, assim como estudos mais específicos para melhor entendimento da dinâmica da matéria orgânica nesses pedoambientes

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

Notas sobre el complejo taxonómico Cardamine flexuosa With. (Cruciferae) y su presencia en la Comunidad Valenciana

Se comunica la presencia de Cardamine flexuosa With. s. str. como primera cita para la Comunidad Valenciana y de Cardamine flexuosa subsp. debilis O. E. Schulz como primera cita para la provincia de Valencia. Se repasan ciertos aspectos nomenclaturales, taxonómicos, corológicos y ecológicos referentes a los dos táxones, así como de Cardamine hirsuta L., especie morfológicamente afín. Se propone una clave dicotómica para la identificación y discriminación de estos tres táxones. Se informa sobre la probable vía de entrada de C. flexuosa s.l. y se evalúa su estado como posible potencial invasor.First record of Cardamine flexuosa With. s. str. from the Valencian Community and first record of Cardamine flexuosa subsp. debilis O. E. Schulz from the Province of Valencia, both placed at Eastern Spain, are reported. Some nomenclatural, taxonomic, chorological and ecological aspects reporting both taxa are reviewed, as well as those related to Cardamine hirsuta L., a morphologically very similar species. A dichotomous key to identify and separate these three taxa is proposed. The introduction way of the alien species C. flexuosa s.l. is suggested and an evaluation of the status as a possible potential invasive species is made

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

Smart Learning

Artificial intelligence applied to the educational field has a vast potential, especially after the e ects worldwide of the COVID-19 pandemic. Online or blended educational modes are needed to respond to the health situation we are living in. The tutorial e ort is higher than in the traditional face-to-face approach. Thus, educational systems are claiming smarter learning technologies that do not pretend to substitute the faculty but make their teaching activities easy. This Special Issue is oriented to present a collection of papers of original advances in educational applications and services propelled by artificial intelligence, big data, machine learning, and deep learning

Primera cita de Epilobium ciliatum Raf. (Onagraceae) en la Comunidad Valenciana

Se comunica la presencia de la especie alóctona Epilobium ciliatum Raf. (Onograceae) en la Comunidad Valenciana (España). Esta cita constituye la segunda referencia para la especie en la Península Ibérica, tras su localización reciente en la Comunidad de Madrid. Se comentan algunos aspectos de su posible introducción en el territorio valenciano así como su estado como planta alóctona potencialmente invasora y los caracteres morfológicos más útiles para su identificación

Proposta de novos procedimentos de identificação de horizonte A húmico.

No processo de revisão do SiBCS, várias tentativas para redefinir horizonte A húmico foram feitas (NAIME; SANTOS, 2007a e 2007b). Com a publicação da 2a edição do SiBCS foi incluído o procedimento que considera a média ponderada da argila e o teor de carbono multiplicado pela espessura do suborizonte (EMBRAPA SOLOS, 2006). Esta proposta para identificação de horizonte A húmico fundamenta-se nos princípios básicos desenvolvidos por Carvalho et al. (2007), com modificação no cálculo do carbono orgânico, isto é, considerando o valor médio (média ponderada) e não o somatório do carbono multiplicado pela espessura do horizonte correspondente como vem sendo utilizado. Há também alteração na equação para estimar o valor mínimo de carbono requerido para horizonte A húmico em função do teor de argila. Em ambos os casos, tanto a argila como o carbono orgânico são relacionados à espessura do horizonte A.bitstream/item/66559/1/doc97-2007-proposta-novos-procedimentos.pd