Generic model transformations: Write once, reuse everywhere

The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-642-21732-6_5Proceedings of 4th International Conference, ICMT 2011, Zurich, Switzerland, June 27-28, 2011Model transformation is one of the core techniques in Model Driven Engineering. Many transformation languages exist nowadays, but few offer mechanisms directed to the reuse of whole transformations or transformation fragments in different contexts. Taking inspiration from generic programming, in this paper we define model transformation templates. These templates are defined over meta-model concepts which later can be bound to specific meta-models. The binding mechanism is flexible as it permits mapping concepts and meta-models with certain kinds of structural heterogeneities. The approach is general and can be applied to any model transformation language. In this paper we report on its application to ATL.Work funded by the Spanish Ministry of Science (projects TIN2008-02081 and TIN2009-11555), and the R&D programme of the Madrid Region (project S2009 /TIC-1650

Observational hints of radial migration in disc galaxies from CALIFA

Context. According to numerical simulations, stars are not always kept at their birth galactocentric distances but they have a tendency to migrate. The importance of this radial migration in shaping galactic light distributions is still unclear. However, if radial migration is indeed important, galaxies with different surface brightness (SB) profiles must display differences in their stellar population properties. Aims: We investigate the role of radial migration in the light distribution and radial stellar content by comparing the inner colour, age, and metallicity gradients for galaxies with different SB profiles. We define these inner parts, avoiding the bulge and bar regions and up to around three disc scale lengths (type I, pure exponential) or the break radius (type II, downbending; type III, upbending). Methods: We analysed 214 spiral galaxies from the CALIFA survey covering different SB profiles. We made use of GASP2D and SDSS data to characterise the light distribution and obtain colour profiles of these spiral galaxies. The stellar age and metallicity profiles were computed using a methodology based on full-spectrum fitting techniques (pPXF, GANDALF, and STECKMAP) to the Integral Field Spectroscopic CALIFA data. Results: The distributions of the colour, stellar age, and stellar metallicity gradients in the inner parts for galaxies displaying different SB profiles are unalike as suggested by Kolmogorov-Smirnov and Anderson-Darling tests. We find a trend in which type II galaxies show the steepest profiles of all, type III show the shallowest, and type I display an intermediate behaviour. Conclusions: These results are consistent with a scenario in which radial migration is more efficient for type III galaxies than for type I systems, where type II galaxies present the lowest radial migration efficiency. In such a scenario, radial migration mixes the stellar content, thereby flattening the radial stellar properties and shaping different SB profiles. However, in light of these results we cannot further quantify the importance of radial migration in shaping spiral galaxies, and other processes, such as recent star formation or satellite accretion, might play a role

Generic meta-modelling with concepts, templates and mixin layers

The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-642-16145-2_2Proceedings of 13th International Conference, MODELS 2010, Oslo, Norway, October 3-8, 2010.Meta-modelling is a key technique in Model Driven Engineering, where it is used for language engineering and domain modelling. However, mainstream approaches like the OMG’s Meta-Object Facility provide little support for abstraction, modularity, reusability and extendibility of (meta-)models, behaviours and transformations. In order to alleviate this weakness, we bring three elements of generic programming into meta-modelling: concepts, templates and mixin layers. Concepts permit an additional typing for models, enabling the definition of behaviours and transformations independently of meta-models, making specifications reusable. Templates use concepts to express requirements on their generic parameters, and are applicable to models and meta-models. Finally, we define functional layers by means of meta-model mixins which can extend other meta-models. As a proof of concept we also report on MetaDepth, a multi-level meta-modelling framework that implements these ideas.Work sponsored by the Spanish Ministry of Science, project TIN2008-02081 and mobility grants JC2009-00015 and PR2009-0019, and by the R&D programme of the Community of Madrid, project S2009/TIC-165

On the Anticorrelation Between Galaxy Light Concentration and X-ray-to-Optical Flux Ratio

Active Galactic Nuclei (AGN) play an important role in many aspects of the modern cosmology, and of particular interest is the issue of the interplay between AGN and their host galaxy. Using X-ray and optical data sets, we have explored the properties of a large sample of AGNs in the Subaru/XMM-Newton Deep Survey (SXDS) field, and studied their evolution in relation with the evolution of their host galaxy. We present here an anticorrelation between X-ray-to-optical flux ratio (X/O) and galaxy light concentration (C), which has been found for the first time and might suggest that early type galaxies, having poor matter supply to feed the AGN activity, have lower Eddington rates than those of late type galaxies.Comment: 9 pages, 3 figures, accepted for publication in ApJ Letter

An NGS-based phylogeny of Orthotricheae (Orthotrichaceae, Bryophyta) with the proposal of the new genus Rehubryum from Zealandia

Phylogenomic data increase the possibilities of resolving the evolutionary and systematic relationships among taxa. This is especially valuable in groups with few and homoplasious morphological characters, in which systematic and taxonomical delimitations have been traditionally difficult. Such is the case of several lineages within Bryophyta, like Orthotrichaceae, the second most diverse family of mosses. Members of tribe Orthotricheae are common in temperate and cold regions, as well as in high tropical mountains. In extratropical areas, they represent one of the main components of epiphytic communities, both in dry and oceanic or hyperoceanic conditions. The epiphytic environment is considered a hostile one for plant development, mainly due to its low capacity of moisture retention. Thus, the diversification of the Orthotrichaceae in this environment could be seen as striking. Over the last two decades, great taxonomic and systematic progresses have led to a rearrangement at the generic level in this tribe, providing a new framework to link environment to patterns of diversification. Here, we use nuclear loci targeted with the GoFlag 408 enrichment probe set to generate a well-sampled phylogeny with well-supported suprageneric taxa and increasing the phylogenetic resolution within the two recognized subtribes. Specifically, we show that several genera with Ulota-like morphology jointly constitute an independent lineage. Within this lineage, the recently described Atlantichella from Macaronesia and Western Europe appears as the sister group of Ulota bellii from Zealandia. This latter species is here segregated in the new genus Rehubryum. Assessment of the ecological and biogeographical affinities of the species within the phylogenetic framework suggests that niche adaptation (including climate and substrate) may be a key evolutionary driver that shaped the high diversification of Orthotrichea

Aplicación de analisis de imagen y tecnología NIRS a la evaluacion de la porosidad de planchas, láminas y tapones de corcho y su relacion con la calidad industrial

The quality of cork is one of the most important issues for the cork industry. It is a complex process that requires evaluating many factors and simultaneously handles continuous and discrete variables, sometimes with a high degree of subjectivity. There are two objectives, in first place to establish the relationship between the commercial quality of the cork and the porosity measured by image analysis at different stages of industrial processing (planks, sheets, and stoppers), and in second place, to evaluate the potential of NIRS technology as a method of assessing the porosity and, therefore, the industrial quality. For this, there has been used a sample group formed by 479 planks, 176 sheets and 90 one piece natural cork stoppers, classified industrially into 4, 2 and 3 quality classes, respectively. The coefficient of porosity was evaluated into two and three classes of color by using image analysis techniques. NIRS spectra were obtained in the transverse section (planks and stoppers), in the tangential section (sheets and stoppers) and in the radial section (stoppers), with a spectrophotometer Foss NIRSystems 6500 SY II, by remote reflectance mode. Statistical analysis of the relationship between quality and coefficient of porosity, measured by image analysis, discriminates two quality classes for planks and sheets, and three classes for stoppers. Classifying the image into a larger number of clusters improves the results. Best NIRS calibrations were obtained measuring the porosity into 3 classes of color, matching the results obtained by image analysis. This allow to discriminate two quality classes in planks (refuse and race), the two classes in sheets (R2 =0.83; r2 =0.78) and the three classes for stoppers (R2 =0.67; r2 =0.53). Due to the difficulties of automated image analysis in the early stages of industrial processing, NIRS technology could be an objective tool to evaluate the porosity and to differentiate two classes of quality in planks and sheets, and three classes in stoppers.La calidad del corcho es una de las cuestiones más relevantes para el sector corchero. Es un proceso complejo que requiere evaluar múltiples factores y manejar simultáneamente variables cuantitativas y cualitativas, en ocasiones, con un alto grado de subjetividad. Se presentan dos objetivos, en primer lugar establecer la relación entre la calidad comercial del corcho y la porosidad medida mediante análisis de imagen en diferentes etapas de la transformación industrial (planchas, láminas y tapones), y en segundo lugar, evaluar el potencial de la tecnología NIRS como método de caracterización de la porosidad y, por tanto, de la calidad industrial. Para ello se ha utilizado un colectivo muestral formado por 479 planchas, 176 láminas y 90 tapones de corcho natural de una pieza, clasificados industrialmente en 4, 2 y 3 clases de calidad, respectivamente. El coeficiente de porosidad se evaluó aplicando técnicas de análisis de imagen, en dos y tres clases de color. Los espectros NIRS se obtuvieron en la sección transversal (planchas y tapones), en la sección tangencial (láminas y tapones) y en la sección radial (tapones), con un espectrofotómetro Foss NIRSystems 6500 SY II, mediante la modalidad de reflectancia remota. El análisis estadístico de la relación entre calidad y coeficiente de porosidad, medido mediante análisis de imagen, permite discriminar dos clases de calidad para planchas y láminas y tres clases para tapones. La clasificación de la imagen en un mayor número de cluster mejora los resultados. Las mejores calibraciones NIRS se obtuvieron para la porosidad medida en 3 clases de color, coincidiendo con los resultados obtenidos mediante análisis de imagen y permiten discriminar dos clases de calidad en planchas (refugo y corcho taponable), las dos clases en láminas (R2 =0,83; r2 =0,78) y las tres clases en tapones (R2 =0,67; r2 =0,53). Debido a las dificultades de automatización del análisis de imagen en las primeras etapas de la transformación industrial, la tecnología NIRS podría ser una herramienta objetiva que permitiera evaluar la porosidad y diferenciar dos clases de calidad en planchas y láminas y tres clases en tapones

The OTELO survey. A case study of [O III]4959,5007 emitters at <z> = 0.83

The OTELO survey is a very deep, blind exploration of a selected region of the Extended Groth Strip and is designed for finding emission-line sources (ELSs). The survey design, observations, data reduction, astrometry, and photometry, as well as the correlation with ancillary data used to obtain a final catalogue, including photo-z estimates and a preliminary selection of ELS, were described in a previous contribution. Here, we aim to determine the main properties and luminosity function (LF) of the [O III] ELS sample of OTELO as a scientific demonstration of its capabilities, advantages, and complementarity with respect to other surveys. The selection and analysis procedures of ELS candidates obtained using tunable filter (TF) pseudo-spectra are described. We performed simulations in the parameter space of the survey to obtain emission-line detection probabilities. Relevant characteristics of [O III] emitters and the LF([O III]), including the main selection biases and uncertainties, are presented. A total of 184 sources were confirmed as [O III] emitters at a mean redshift z=0.83. The minimum detectable line flux and equivalent width (EW) in this ELS sample are $\sim$5 $\times$ 10$^{-19}$ erg s$^{-1}$ cm$^{2}$ and $\sim$6 \AA, respectively. We are able to constrain the faint-end slope ($\alpha = -1.03\pm0.08$) of the observed LF([O III]) at z=0.83. This LF reaches values that are approximately ten times lower than those from other surveys. The vast majority (84\%) of the morphologically classified [O III] ELSs are disc-like sources, and 87\% of this sample is comprised of galaxies with stellar masses of M$_\star$ $<$ 10$^{10}$ M$_{\odot}$.Comment: v1: 16 pages, 6 figures. Accepted in Astronomy \& Astrophysics. v2: Author added in metadat

Galaxy classification: deep learning on the OTELO and COSMOS databases

Context. The accurate classification of hundreds of thousands of galaxies observed in modern deep surveys is imperative if we want to understand the universe and its evolution. Aims. Here, we report the use of machine learning techniques to classify early- and late-type galaxies in the OTELO and COSMOS databases using optical and infrared photometry and available shape parameters: either the Sersic index or the concentration index. Methods. We used three classification methods for the OTELO database: 1) u-r color separation , 2) linear discriminant analysis using u-r and a shape parameter classification, and 3) a deep neural network using the r magnitude, several colors, and a shape parameter. We analyzed the performance of each method by sample bootstrapping and tested the performance of our neural network architecture using COSMOS data. Results. The accuracy achieved by the deep neural network is greater than that of the other classification methods, and it can also operate with missing data. Our neural network architecture is able to classify both OTELO and COSMOS datasets regardless of small differences in the photometric bands used in each catalog. Conclusions. In this study we show that the use of deep neural networks is a robust method to mine the cataloged dataComment: 20 pages, 10 tables, 14 figures, Astronomy and Astrophysics (in press