Detailed atmospheric abundance analysis of the optical counterpart of the IR source IRAS 16559-2957

We have undertaken a detailed abundance analysis of the optical counterpart of the IR source IRAS16559-2957 with the aim of confirming its possible post-AGB nature. The star shows solar metallicity and our investigation of a large number of elements including CNO and 12C/13C suggests that this object has experienced the first dredge-up and it is likely still at RGB stage.Comment: 10 pages, 4 figures, 4 tables. To be published by Revista Mexicana de Astronomia y Astrofisica, April 201

Are There Cost Differences in the Argentinean Pension Fund Industry? An Efficiency Frontier Analysis

The purpose of this paper is to study the existence of differences in costs between pension fund administrators (PFAs) through the estimation of an econometric cost frontier for Argentina. Like in other eleven Latin American, and some other Central Asian and Eastern Europe countries, the social security has been privatized, and the individual accounts of defined contribution plans are managed by PFAs. The issue is relevant because of its potential regulatory implications. Cost savings (efficiency gains) could be passed-through to contributors, increasing their pension funds (that is, their pensions at retirement). The concept is applied to utilities’ regulation in countries where price-caps are applied, and an X-factor is set by the regulator to distribute the efficiency gains, but it is not the practice in privatized social security systems. In Argentina a price-cap has been introduced in pension funds markets since a 2007 reform. Though it allows the regulator to modify that cap, in doing that no provision was established for a technically acceptable methodology. We show that the use of efficiency frontiers could fill the gap, because it provides a technical tool to help in that key resource allocation decision. From the empirical work, it is found that there are important differences in efficiency among PFAs. This gives some clues to the regulator for implementing sector policies.pension fund; Efficiency Frontier Analysis

Efficiency in Water and Sanitation Sector. A Survey on Empirical Literature

In this paper, it was made an exhaustive survey of the literature related with cost and production frontiers in the water and sanitation sector. The survey shed light in order to determine the variables to choose in the model to be estimated in a further empirical estimation developed for the Latin American Region by the authorsfrontiers; water and sanitation sector; empirical estimation

A Benchmarking Exercise on Latin American Water Util

The aim of this study is to estimate both stochastic and mathematical programming cost functions and frontier studies with the ADERASA’s database. ADERASA is a Latin American association of water regulators, which has done a systematic effort on data collection. Econometric and DEA techniques were employed here. This study fills a gap on the understanding of relative efficiency in the Latin American water sector., through a consistent database. Firstly we present a survey of the empirical literature related with cost and production frontiers in the water and sanitation sector. The survey shed light in order to determine the variables to choose in the models to be estimated. Secondly, some models were estimated, differing each other on the specification, and the environmental variables included. The results are satisfactory, with the expected signs and plausible values for the coefficients. Some consistency between methodologies was found.Benchmarking; cost functions; frontier; stochastic model; ADERASA

Fourier Decomposition of RR Lyrae light curves and the SX Phe population in the central region of NGC 3201

CCD time-series observations of the central region of the globular cluster NGC~3201 were obtained with the aim of performing the Fourier decomposition of the light curves of the RR~Lyrae stars present in that field. This procedure gave the mean values, for the metallicity, of [Fe/H]$_{ZW}=-1.483 \pm 0.006$ (statistical) $\pm 0.090$ (systematical), and for the distance, $5.000 \pm 0.001$~kpc (statistical) $\pm 0.220$ (systematical). The values found from two RRc stars are consistent with those derived previously. The differential reddening of the cluster was investigated and individual reddenings for the RR Lyrae stars were estimated from their $V-I$ curves. We found an average value of $E(B-V)= 0.23 \pm 0.02$. An investigation of the light curves of stars in the {\it blue stragglers} region led to the discovery of three new SX~Phe stars. The period-luminosity relation of the SX~Phe stars was used for an independent determination of the distance to the cluster and of the individual reddenings. We found a distance of 5.0 kpcComment: To appear in Revista Mexicana de Astronom\'ia y Astrof\'isica, Octuber 2014 issue, Vol 50. 17 pages, 10 figure

Reduction of Lie--Jordan algebras: Quantum

In this paper we present a theory of reduction of quantum systems in the presence of symmetries and constraints. The language used is that of Lie--Jordan Banach algebras, which are discussed in some detail together with spectrum properties and the space of states. The reduced Lie--Jordan Banach algebra is characterized together with the Dirac states on the physical algebra of observables