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

Origin of the negative differential resistance in the output characteristics of a picene-based thin-film transistor

© 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.In this work, we have fabricated and studied p-type picene thin-film transistors. Although the devices exhibited good electrical performance with high field-effect mobility (up to 1.3 cm2/V¿s) and on/off ratios above 105, the output electric characteristics of the devices exhibited a Negative Differential Resistance for higher drain-source voltage. Finally, a possible explanation for this phenomenon is developed.Peer ReviewedPostprint (author's final draft

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

Prótesis como solución en fractura de caninos

La prótesis a nivel odontológico es una solución poco utilizada, debido por un lado al desconocimiento de sus indicaciones y a la problemática de no tener fácil acceso a protésicos veterinarios o de humana que por un lado estén dispuestos a colaborar con nosotros o bien que estén plenamente calificados para realizarlas. Por otro lado, todo ello implica un alto coste. Presentamos un caso clínico en el que se efectuó una prótesis de un canino, mediante una funda en material metálico con la suficiente resistencia para el perfecto funcionamiento de ésta, perdurando a largo plazo.The prothesis at odontological level is a seldom used solution; due, in one hand, to the unfamiliarity of its indications and the problem of not having an easy access to human or veterinary prothesis technicien willing to cooperate with us or fully quelifies to do it. On the other hand, all of it implies high costs. We are presenting a clinic case in which a prothesis was done on a canine by metalic-material case with enough resistance to operase properly and lasting on the long term

An approach to a reference model for a sentient smart city

The interest about Smart City concept has in creased in recent years. In fact, Smart Cities is ex pected to improve cityzens life experience by driv ing the next digital revolution, moving from the personal area (mobile computing, smart home) to the urban area (collective computing and collective intelligence). But the development of Smart Cities is not being as fast as expected. Several problems need to be undertaken in order to achieve the ob jectives of the paradigm. This paper presents an approach to address one of these problems: to or chestrate the platform that is required for gathering information about city, store it in a model and ena ble it for exploitation. The heterogeneity of the po tential data sources available and the complexity of the information nature and structure, make it a non trivial task that have to be solved before commer cial solutions appear and provide specific and non interoperable solutions

Carnot, Stirling, Ericsson stochastic heat engines: Efficiency at maximum power

This work obtains the efficiency at maximum power for a stochastic heat engine performing Carnot-like, Stirling-like and Ericsson-like cycles. For the mesoscopic engine a Brownian particle trapped by an optical tweezers is considered. The dynamics of this stochastic engine is described as an overdamped Langevin equation with a harmonic potential, whereas is in contact with two thermal baths at different temperatures, namely, hot ($T_h$) and cold ($T_c$). The harmonic oscillator Langevin equation is transformed into a macroscopic equation associated with the mean value $\langle x^2(t)\rangle$ using the original Langevin approach. At equilibrium stationary state this quantity satisfies a state-like equation from which the thermodynamic properties are calculated. To obtained the efficiency at maximum power it is considered the finite-time cycle processes under the framework of low dissipation approach.Comment: 2 3pages, 5 figure

Kν10.1 K⁺ - channel plasma membrane discrete domain partitioning and its functional correlation in neurons

AbstractKV10.1 potassium channels are implicated in a variety of cellular processes including cell proliferation and tumour progression. Their expression in over 70% of human tumours makes them an attractive diagnostic and therapeutic target. Although their physiological role in the central nervous system is not yet fully understood, advances in their precise cell localization will contribute to the understanding of their interactions and function. We have determined the plasma membrane (PM) distribution of the KV10.1 protein in an enriched mouse brain PM fraction and its association with cholesterol- and sphingolipid-rich domains. We show that the KV10.1 channel has two different populations in a 3:2 ratio, one associated to and another excluded from Detergent Resistant Membranes (DRMs). This distribution of KV10.1 in isolated PM is cholesterol- and cytoskeleton-dependent since alteration of those factors changes the relationship to 1:4. In transfected HEK-293 cells with a mutant unable to bind Ca2+/CaM to KV10.1 protein, Kv10.1 distribution in DRM/non-DRM is 1:4. Mean current density was doubled in the cholesterol-depleted cells, without any noticeable effects on other parameters. These results demonstrate that recruitment of the KV10.1 channel to the DRM fractions involves its functional regulation