The oxygen abundance in the IFU era

Spatially-resolved information of gas-phase emission provided by integral field units (IFUs) are allowing us to perform a new generation of emission-line surveys, based on large samples of HII regions and full two-dimensional coverage. Here we present two highlights of our current studies employing this technique: 1) A statistical approach to the abundance gradients of spiral galaxies, which indicates an -universal- radial gradient for oxygen abundance; and 2) The discovery of a new scaling relation of HII regions in spiral galaxies, the "local" mass-metallicity relation of star-forming galaxies.Comment: 6 pages, to appear in Highlights of Spanish Astrophysics VII, Proceedings of the X Scientific Meeting of the Spanish Astronomical Society held on July 9-13, 2012, in Valencia, Spai

Inner and outer star forming regions over the disks of spiral galaxies. I. Sample characterization

Context. The knowledge of abundance distributions is central to understanding the formation and evolution of galaxies. Most of the relations employed for the derivation of gas abundances have so far been derived from observations of outer disk HII regions, despite the known differences between inner and outer regions. Aims. Using integral field spectroscopy (IFS) observations we aim to perform a systematic study and comparison of two inner and outer HII regions samples. The spatial resolution of the IFS, the number of objects and the homogeneity and coherence of the observations allow a complete characterization of the main observational properties and differences of the regions. Methods. We analyzed a sample of 725 inner HII regions and a sample of 671 outer HII regions, all of them detected and extracted from the observations of a sample of 263 nearby, isolated, spiral galaxies observed by the CALIFA survey. Results. We find that inner HII regions show smaller equivalent widths, greater extinction and luminosities, along with greater values of [NII]{\lambda}6583/H{\alpha} and [OII]{\lambda}3727/[OIII]{\lambda}5007 emission-line ratios, indicating higher metallicites and lower ionization parameters. Inner regions have also redder colors and higher photometric and ionizing masses, although Mion/Mphot is slighty higher for the outer regions. Conclusions. This work shows important observational differences between inner and outer HII regions in star forming galaxies not previously studied in detail. These differences indicate that inner regions have more evolved stellar populations and are in a later evolution state with respect to outer regions, which goes in line with the inside-out galaxy formation paradigm.Comment: 16 page

PPAK Wide-field Integral Field Spectroscopy of NGC 628: II. Emission line abundance analysis

In this second paper of the series, we present the 2-dimensional (2D) emission line abundance analysis of NGC 628, the largest object within the PPAK Integral Field Spectroscopy (IFS) Nearby Galaxies Survey: PINGS. We introduce the methodology applied to the 2D IFS data in order to extract and deal with large spectral samples, from which a 2D abundance analysis can be later performed. We obtain the most complete and reliable abundance gradient of the galaxy up-to-date, by using the largest number of spectroscopic points sampled in the galaxy, and by comparing the statistical significance of different strong-line metallicity indicators. We find features not previously reported for this galaxy that imply a multi-modality of the abundance gradient consistent with a nearly flat-distribution in the innermost regions of the galaxy, a steep negative gradient along the disc and a shallow gradient or nearly-constant metallicity beyond the optical edge of the galaxy. The N/O ratio seems to follow the same radial behaviour. We demonstrate that the observed dispersion in metallicity shows no systematic dependence with the spatial position, signal-to-noise or ionization conditions, implying that the scatter in abundance for a given radius is reflecting a true spatial physical variation of the oxygen content. Furthermore, by exploiting the 2D IFS data, we were able to construct the 2D metallicity structure of the galaxy, detecting regions of metal enhancement, and showing that they vary depending on the choice of the metallicity estimator. The analysis of axisymmetric variations in the disc of NGC 628 suggest that the physical conditions and the star formation history of different-symmetric regions of the galaxy have evolved in a different manner.Comment: Accepted for publication in MNRAS, 40 pages, 22 figures, online data: http://www.ast.cam.ac.uk/ioa/research/ping

The role of gas infall in the evolution of disc galaxies

Spiral galaxies are thought to acquire their gas through a protracted infall phase resulting in the inside-out growth of their associated discs. For field spirals, this infall occurs in the lower density environments of the cosmic web. The overall infall rate, as well as the galactocentric radius at which this infall is incorporated into the star-forming disc, plays a pivotal role in shaping the characteristics observed today. Indeed, characterising the functional form of this spatio-temporal infall in-situ is exceedingly difficult, and one is forced to constrain these forms using the present day state of galaxies with model or simulation predictions. We present the infall rates used as input to a grid of chemical evolution models spanning the mass spectrum of discs observed today. We provide a systematic comparison with alternate analytical infall schemes in the literature, including a first comparison with cosmological simulations. Identifying the degeneracies associated with the adopted infall rate prescriptions in galaxy models is an important step in the development of a consistent picture of disc galaxy formation and evolution.Comment: 12 pages, 12 figures, MNRAS, accepte

Robots for inclusive classrooms: a scoping review

Robot-based activities have been proven to be a valuable tool for children with learning and developmental disabilities. However, their feasibility in general educational environments needs further exploration. This scoping review provides a critical examination of robot-based learning experiences involving children with disabilities, implemented either in mainstream schools or in specialized centers in order to gain insight into their potential to support inclusion. For this purpose, a search was conducted in the multidisciplinary Scopus and WoS databases, completed with Dialnet database. Based on PRISMA guidelines for literature reviews, we limited the systematic analysis to 33 papers published after 2009 that contain information on the instructional design and details of how the activities were implemented. On the other hand, studies reporting interventions with robots for clinical purposes were excluded as well as papers focused exclusively on technical developments. Content analysis shows that most experiences lead to improvements in terms of educational goals and/or stakeholders’ satisfaction. However, the analysis also reported issues that may hinder the adoption of these practices in general classrooms and integrated education services. The reported difficulties include the lack of stability and autonomy of the robots used, the need for aids and adaptations to enable children with sensory and physical impairments to interact easily with the robots, and the requirement of technical support with system’s setup, implementation and maintenance. We conclude that robots and robotics are a powerful tool to address the needs of diverse learners who are included in mainstream classrooms. This review aims at presenting evidences of good practices and recommendations for successful implementation.Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. The authors did not receive support from any organization for the submitted work.Peer ReviewedPostprint (published version

The role of gas infall in the evolution of disc galaxies

Spiral galaxies are thought to acquire their gas through a protracted infall phase resulting in the inside-out growth of their associated discs. For field spirals, this infall occurs in the lower density environments of the cosmic web. The overall infall rate, as well as the galactocentric radius at which this infall is incorporated into the star-forming disc, plays a pivotal role in shaping the characteristics observed today. Indeed, characterising the functional form of this spatio-temporal infall in-situ is exceedingly difficult, and one is forced to constrain these forms using the present day state of galaxies with model or simulation predictions. We present the infall rates used as input to a grid of chemical evolution models spanning the mass spectrum of discs observed today. We provide a systematic comparison with alternate analytical infall schemes in the literature, including a first comparison with cosmological simulations. Identifying the degeneracies associated with the adopted infall rate prescriptions in galaxy models is an important step in the development of a consistent picture of disc galaxy formation and evolution

Design issues for the VLSI implementation of universal approximator fuzzy systems

Comunicación presentada al "CSCC'99" celebrado en Atenas en Julio de 1999.Several VLSI realizations of fuzzy systems have been proposed in the literature in the recent years. They employ analog or digital circuitry, offering more or less programmability, implementing different inference methods, with different types of membership functions as well as different antecedents’ connectives. This paper centers this wide design space by fixing several parameters that allow efficient VLSI implementations of programmable fuzzy systems featuring first, second and third order accurate approximation. Hardware requirements are discussed and compared from the point of view of approximation capability or precision, thus attempting to a formalization that has never been applied before to the field of fuzzy hardware.This work has been partially supported by the Spanish CICYT Project TIC98-0869.Peer reviewe

Corrección de consolidación viciosa diafisaria de fémur: osteotomía en caparazón. A propósito de dos casos.

La adecuada alineación del miembro inferior es esencial para el adecuado reparto de cargas que permita una deambulación sin alteraciones. Por lo que a la hora del tratamiento de fracturas de huesos largos del miembro inferior, fundamentalmente fémur y tibia, habrá que evitar cualquier deformidad angular que a medio plazo provoque fenómenos degenerativos en las articulaciones adyacentes. Se presentan dos casos clínicos complejos, en los que se corrigieron sendas consolidaciones viciosas de fracturas diafisarias de fémur satisfactoriamente, mediante osteotomía tipo caparazón o clamshellThe lower limb alignment is essential to share correctly the bearing weight of the body to allow a suitable gait. We should take it into account when treating femoral and tibial diaphyseal fractures, in order to avoid angular deformities which could lead to degenerative changes in adjacent joints. We report two complex cases, with femoral shaft malunions corrected satisfactorily by using a clamshell osteotom