Effect of deformation on two-neutrino double beta decay matrix elements

We study the effect of deformation on the two-neutrino double beta decay for ground state to ground state transitions in all the nuclei whose half-lives have been measured. Our theoretical framework is a deformed QRPA based in Woods-Saxon or Hartree-Fock mean fields. We are able to reproduce at the same time the main characteristics of the two single beta branches, as well as the double beta matrix elements. We find a suppression of the double beta matrix element with respect to the spherical case when the parent and daughter nuclei have different deformations

Nuclear shape dependence of Gamow-Teller distributions in neutron-deficient Pb isotopes

We study Gamow-Teller strength distributions in the neutron-deficient even isotopes (184-194)Pb in a search for signatures of deformation. The microscopic formalism used is based on a deformed quasiparticle random phase approximation (QRPA) approach, which involves a self-consistent quasiparticle deformed Skyrme Hartree-Fock (HF) basis and residual spin-isospin forces in both the particle-hole and particle-particle channels. By analyzing the sensitivity of the Gamow-Teller strength distributions to the various ingredients in the formalism, we conclude that the beta-decay of these isotopes could be a useful tool to look for fingerprints of nuclear deformation.Comment: 20 pages, 11 figures. To be published in Physical Review

Blood–brain barrier and foetal-onset hydrocephalus, with a view on potential novel treatments beyond managing CSF flow

[EN] Despite decades of research, no compelling non-surgical therapies have been developed for foetal hydrocephalus. So far, most efforts have pointed to repairing disturbances in the cerebrospinal fluid (CSF) flow and to avoid further brain damage. There are no reports trying to prevent or diminish abnormalities in brain development which are inseparably associated with hydrocephalus. A key problem in the treatment of hydrocephalus is the blood–brain barrier that restricts the access to the brain for therapeutic compounds or systemically grafted cells. Recent investigations have started to open an avenue for the development of a cell therapy for foetal-onset hydrocephalus. Potential cells to be used for brain grafting include: (1) pluripotential neural stem cells; (2) mesenchymal stem cells; (3) geneticallyengineered stem cells; (4) choroid plexus cells and (5) subcommissural organ cells. Expected outcomes are a proper microenvironment for the embryonic neurogenic niche and, consequent normal brain development

Gamow-Teller strength distributions in Xe isotopes

The energy distributions of the Gamow-Teller strength are studied for even-even Xe isotopes with mass numbers from 124 to 142. A self-consistent microscopic formalism is used to generate the single particle basis, using a deformed Skyrme Hartree-Fock mean field with pairing correlations in BCS approximation. The Gamow-Teller transitions are obtained within a quasiparticle random phase approximation (QRPA) approach using a residual spin-isospin interaction in the particle-hole and particle-particle channels. We then discuss the pairing BCS treatment and the determination of the ph and pp residual interaction coupling constants. We study the GT+ and GT- strength distributions for the equilibrium nuclear shapes, which are an essential information for studies of charge-exchange reactions and double-beta processes involving these isotopes.Comment: 15 pages, 5 figures. To appear in Phys Rev

Alteraciones morfológicas en riñones de ratas sometidos a isquemia reperfusión

Fundamento: La isquemia reperfusión renal es un proceso en donde se involucra una serie de eventos que pueden conducir al daño y muerte celular. Objetivo: Determinar las modificaciones morfológicas que se producen en el riñón a medida que progresa el tiempo en el proceso de isquemia reperfusión. Métodos: Se utilizó como muestra un grupo de 35 ratas Wistar, machos, que fueron divididos en cinco grupos de siete ratas cada uno. Al subgrupo que no se le provocó isquemia se le denominó control (C) y al resto se les nombró experimentales (E). El subgrupo experimental E- I fue sometido a 15 minutos de isquemia, el E-II a 30 minutos, el E-III a 45 minutos y el E-IV a una hora. Luego se tomaron muestras de tejido renal para estudio morfométrico. Resultados: Se produjo una reducción significativa del número de glomérulos y de la fracción de área ocupada por estos tras isquemia reperfusión temporal de 15 minutos (EI), la que parece ser reversible por la ligera mejoría observada tras 30 minutos (EII) a partir del cual sigue recayendo hasta después de una hora de isquemia reperfusión (EIV). Conclusiones: La combinación de isquemia con reperfusión supera el tiempo crítico para provocar lesión irreversible celular del tejido renal

Arquitectura de Control Cognitivo Artificial usando una plataforma computacional de bajo coste.

Hoy en día, las principales líneas de investigación tanto en Europa como de EEUU a nivel industrial, abordan aspectos como la interacción hombre-robot y dotar de inteligencia a las máquinas, y por tanto tienen un papel fundamental a la hora de desarrollar cualquier propuesta. Una manera de dotar a las máquinas de conocimiento de la operación que realizan y su interacción con el resto del flujo productivo es la utilización de arquitecturas de control inteligente artificial. A pesar que dichas arquitecturas están dentro de las áreas de investigación priorizadas, aún existen muchas restricciones para su aplicación en la industria de manera general. En este trabajo se propone la emulación de las experiencias socio-cognitivas del ser humano para la toma de decisiones a escala industrial. Las técnicas basadas en Lógica Borrosa, la optimización heurística y las técnicas de auto-aprendizaje desempeñan cada día un papel más importante a la hora de crear los diferentes niveles o capas dentro del sistema. En este trabajo se implementa una arquitectura de control cognitiva artificial enfocada en cuatro aspectos fundamentales: capacidades de auto-aprendizaje y auto-optimización para la estimación; portabilidad y escalabilidad basada en plataformas computacionales de bajo coste; conectividad basada en middleware y enfoque basado en modelos para la estimación y predicción de estados. Finalmente se muestran algunos ensayos de validación en un proceso de microtaladrado que muestran una buena respuesta transitoria y un error de estado estacionario aceptable. Sin lugar a dudas, con la arquitectura de control cognitivo artificial propuesta se sientan las bases para su futura aplicación en una instalación industrial

Análisis del clima urbano a partir de imágenes de satélite en el centro peninsular español

In this paper, urban thermic island of some cities of central Spain (Madrid, Segovia, Ávila, Guadalajara and Toledo), with very different natural and social characteristics, has been analyzed. Field-city thermic contrasts have been drawn out through NOAA and Landsat images, as well as weather stations data. Diurnal temperatures are often lower inside the cities than on not urbanised areas of their surroundings. This urban thermical anomaly seems to be related to the different heating-cooling rate of the land cover, so «urban heat island» is only apparent by night, while, inversely, during day time these cities show an «urban cool island» in relation to their neighbouring areas. In this way, cities work as heat accumulators during day time and releasing the stored energy during night.Este trabajo analiza la isla térmica urbana de ciudades del centro de España (Madrid, Segovia, Ávila, Guadalajara y Toledo), con características físicas y humanas muy dispares. El contraste térmico campo-ciudad se analiza a partir de la información aportada por los satélites NOAA y Landsat y por las estaciones meteorológicas. Las temperaturas diurnas resultan con frecuencia más bajas en el interior de las ciudades que en las áreas no urbanizadas de su entorno. Esta anomalía térmica urbana diurna parece responder al distinto ritmo de caldeamiento-enfriamiento de los materiales, de modo que la «isla de calor urbana» sólo se manifiesta por la noche, mientras que durante el día las ciudades estudiadas muestran una «isla de frío» respecto a su entorno. Así, las ciudades estarían funcionando como acumuladores térmicos durante el día, y liberando la energía almacenada en todo el entramado urbano por la noche

A collection of three integration-free iPSCs derived from old male and female healthy subjects

Here, we present the characterization of three iPSC lines derived from dermal fibroblasts of old healthy subjects. Fibroblasts were reprogrammed using Sendai viral vectors encoding OCT4, SOX2, KLF4 and c-MYC. The iPSCs expressed endogenous pluripotency markers, could generate the three germ layers (ectoderm, mesoderm and endoderm), maintained a stable karyotype, and were free from Sendai vectors and reprogramming factors. These integration-free iPSCs can serve for establishing control cell cultures in studies searching for phenotypes and mechanisms that could potentially be dysregulated in degenerative diseases

beta-decay in neutron-deficient Hg, Pb, and Po isotopes

The effect of nuclear deformation on the energy distributions of the Gamow-Teller strength is studied in neutron-deficient Hg, Pb, and Po even isotopes. The theoretical framework is based on a self-consistent deformed Skyrme Hartree-Fock mean field with pairing correlations between like nucleons in BCS approximation and residual spin-isospin interactions treated in the proton-neutron quasiparticle random phase approximation. After a systematic study of the Gamow-Teller strength distributions in the low excitation energy region, relevant for beta-decay, we have identified the best candidates to look for deformation signatures in their beta-decay patterns. beta+ half-lives and total Gamow-Teller strengths B(GT+) and B(GT-) are analyzed as well.Comment: 18 pages, 7 figures, to appear in Phys. Rev.

Relativistic description of 3He(e,e'p)2H

The Relativistic Distorted-Wave Impulse Approximation is used to describe the $^3$He($e,e^\prime p$)$^2$H process. We describe the $^3$He nucleus within the adiabatic hyperspherical expansion method with realistic nucleon-nucleon interactions. The overlap between the $^3$He and the deuteron wave functions can be accurately computed from a three-body calculation. The nucleons are described by solutions of the Dirac equation with scalar and vector (S-V) potentials. The wave function of the outgoing proton is obtained by solving the Dirac equation with a S-V optical potential fitted to elastic proton scattering data on the residual nucleus. Within this theoretical framework, we compute the cross section of the reaction and other observables like the transverse-longitudinal asymmetry, and compare them with the available experimental data measured at JLab.Comment: 4 pages, 3 figures. Proceedings of the 21st European Few Body Conference held in Salamanca (Spain) in August-September 201