The value of the fine structure constant over cosmological times

The optical spectra of objects classified as QSOs in the SDSS DR6 are analyzed with the aim of determining the value of the fine structure constant in the past and then check for possible changes in the constant over cosmological timescales. The analysis is done by measuring the position of the fine structure lines of the [OIII] doublet (4959 and 5008) in QSO nebular emission. From the sample of QSOs at redshifts z < 0.8 a subsample was selected on the basis of the amplitude and width of the [OIII] lines. Two different method were used to determine the position of the lines of the [OIII] doublet, both giving similar results. Using a clean sample containing 1568 of such spectra, a value of Delta alpha /alpha=(+2.4 +-2.5) x 10^{-5} (in the range of redshifts 0-0.8) was determined. The use of a larger number of spectra allows a factor ~5 improvement on previous constraints based on the same method. On the whole, we find no evidence of changes in alpha on such cosmological timescales. The mean variation compatible with our results is 1/ Delta alpha/alpha=(+0.7 +- 0.7) x 10^{-14} yr^{-1}. The analysis was extended to the [NeIII] and [SII] doublets, although their usefulness is limited due to the fact that all these doublets in QSOs tend to be fainter than [OIII], and that some of them are affected by systematics.Comment: 22 pages, 10 figures. Accepted for publication in Astrophysical Journa

Diagnostic concordance of DSM-IV and DSM-5 Posttraumatic Stress Disorder (PTSD) in a clinical sample

The present study aims to analyze diagnostic concordance between the DSM-IV and the DSM-5 for posttraumatic stress disorder (PTSD) diagnostic criteria and their different groups of symptoms. Furthermore, analyses are conducted to establish the features of participants with no concordant diagnoses. Method: The study assessed 166 people over 18 who had experienced at least one traumatic event. PTSD diagnosis was established using the Global Scale for Posttraumatic Stress (EGEP), a self-report measure to assess PTSD. Results: The presence of cognitive avoidance was a determinant in the PTSD DSM-5 diagnosis (86% positive predictive value). The analysis of the non-concordant individuals revealed that individuals who were diagnosed according to the DSM-IV criteria but not the DSM-5 criteria were primarily indirect victims. Conversely, individuals who were diagnosed with the DSM-5 criteria and not with the DSM-IV criteria presented cognitive avoidance and alterations in cognition not included in the DSM-IV criteria. Conclusions: A withinsubjects concordance analysis showed high agreement for PTSD diagnosis between the two classifi cations. Differences between the diagnoses are due to the new defi nition of C (avoidance) and D (negative alterations in cognitions and mood) in the DSM-

Generative capacities of cellular automata codification for evolution of NN codification

Proceeding of: International Conference on Artificial Neural Networks. ICANN 2002, Madrid, Spain, August 28-30, 2002Automatic methods for designing artificial neural nets are desired to avoid the laborious and erratically human expert’s job. Evolutionary computation has been used as a search technique to find appropriate NN architectures. Direct and indirect encoding methods are used to codify the net architecture into the chromosome. A reformulation of an indirect encoding method, based on two bi-dimensional cellular automata, and its generative capacity are presented.Publicad

Estudio de viabilidad de la reutilización de baños de tintura textil

En este trabajo se hace un estudio de viabilidad técnica y económica de la integración de un tratamiento de decoloración de baños agotados de tintura a un proceso de tintura téxtil convencional con el objetivo de reutilizar el agua tratada y en especial, de aprovechar la sal necesaria para realizar la tintura. El tratamiento de decoloración se lleva a cabo en una celula electroquímica asistida por luz ultravioleta y el agua decolorada es almacenada en un deposito para su posterior reutilización en el proceso de tintura. La implementación de este sistema de tratamiento y reutilización permite ahorrar el 70% de agua y el 60% de la sal necesarios para preparar los banos de tintura. Lo que aparte de reportar una horro económico directo, también supone un ahorro en el cánon de vertido de aguas residuales. Por el contrario, si se quiere hacer un proceso ininterrumpido de sucesivas reutilizaciones, en algunas ocasiones y en función del color requerido, debe aumentarse la cantidad de colorante respecto de la fórmula inicial para evitar una merma en la calidad de las tinturas y precisamente por ello es importante la realización del estudio económico para demostrar su viabilidad

Estudio experimental y numérico de uniones con angulares ejecutadas con perfiles europeos

In this paper, four specimens with different thickness of top and seat angle with double web angle connections are experimentally tested and numerically modeled. The model has been solved by means of Abaqus® finite element package. Moment rotation curves obtained from the experiments are compared with those obtained from FE models and good agreement is observed. These results validate this numerical modeling in order to use it in future studies on angle connections.En este artículo se presenta el ensayo experimental y el modelo numérico de cuatro uniones de estructura metálica realizadas con casquillos angulares de diferentes espesores. El problema se ha resuelto mediante el programa comercial de elementos finitos Abaqus®. Las curvas experimentales momento-rotación obtenidas concuerdan razonablemente con los resultados de los modelos propuestos, de modo que con este trabajo se ha establecido una base numérica sólida para estudios posteriores

Non-Direct Encoding Method Based on Cellular Automata to Design Neural Network Architectures

Architecture design is a fundamental step in the successful application of Feed forward Neural Networks. In most cases a large number of neural networks architectures suitable to solve a problem exist and the architecture design is, unfortunately, still a human expert’s job. It depends heavily on the expert and on a tedious trial-and-error process. In the last years, many works have been focused on automatic resolution of the design of neural network architectures. Most of the methods are based on evolutionary computation paradigms. Some of the designed methods are based on direct representations of the parameters of the network. These representations do not allow scalability; thus, for representing large architectures very large structures are required. More interesting alternatives are represented by indirect schemes. They codify a compact representation of the neural network. In this work, an indirect constructive encoding scheme is proposed. This scheme is based on cellular automata representations and is inspired by the idea that only a few seeds for the initial configuration of a cellular automaton can produce a wide variety of feed forward neural networks architectures. The cellular approach is experimentally validated in different domains and compared with a direct codification scheme.Publicad