Influence of turbidity and clouds on satellite total ozone data over Madrid (Spain)

This article focuses on the comparison of the total ozone column data from three satellite instruments; Total Ozone Mapping Spectrometers (TOMS) on board the Earth Probe (EP), Ozone Monitoring Instrument (OMI) on board AURA and Global Ozone Monitoring Experiment (GOME) on board ERS/2, with ground-based measurement recorded by a well calibrated Brewer spectrophotometer located in Madrid during the period 1996–2008. A cluster classification based on solar radiation (global, direct and diffuse), cloudiness and aerosol index allow selecting hazy, cloudy, very cloudy and clear days. Thus, the differences between Brewer and satellite total ozone data for each cluster have been analyzed. The accuracy of EP-TOMS total ozone data is affected by moderate cloudiness, showing a mean absolute bias error (MABE) of 2.0%. In addition, the turbidity also has a significant influence on EP-TOMS total ozone data with a MABE ~1.6%. Those data are in contrast with clear days with MABE ~1.2%. The total ozone data derived from the OMI instrument show clear bias at clear and hazy days with small uncertainties (~0.8%). Finally, the total ozone observations obtained with the GOME instrument show a very smooth dependence with respect to clouds and turbidity, showing a robust retrieval algorithm over these conditions.Manuel Ant´on thanks Ministerio de Ciencia e Innovaci´on and Fondo Social Europeo for the award of a postdoctoral grant (Juan de la Cierva). This work was partially supported by Ministerio de Ciencia e Innovacion under project CGL2008-05939-C03-02/CLI

Renormalized Kaluza-Klein theories

Using six-dimensional quantum electrodynamics ($QED_6$) as an example we study the one-loop renormalization of the theory both from the six and four-dimensional points of view. Our main conclusion is that the properly renormalized four dimensional theory never forgets its higher dimensional origin. In particular, the coefficients of the neccessary extra counterterms in the four dimensional theory are determined in a precise way. We check our results by studying the reduction of $QED_4$ on a two-torus.Comment: LaTeX, 36 pages. A new section added; references improved, typos fixe

Las fuerzas armadas peronistas (FAP): los orígenes de la guerrilla peronista y sus debates políticos estratégicos

La historia de las Fuerzas Armadas Peronistas (FAP) es un hecho que no ha recibido demasiada atención por parte de los análisis que sobre la guerrilla argentina se han realizado. Sin embargo, el hecho concreto de haber sido una de las Organizaciones fundantes de este fenómeno en la Argentina, nos ha llevado a plantearnos la necesidad de su abordaje a fin de intentar contribuir de un modo más integral a la comprensión de la emergencia de la lucha armada, desarrolla durante las décadas del sesenta y el setenta. La lucha armada fue la expresión de la radicalización política de sectores juveniles que provocó un cambio cualitativo en el proceso político nacional de la época, que se tradujo en el llamamiento la GAN y en la reincorporación del Peronismo al sistema político como forma de buscar la pacificación nacional. En ese sentido, el presente trabajo es primer intento de acercamiento a esta Organización y lo hemos desarrollado a través de un proyecto de investigación en el marco del “Taller de protesta social, crisis política y formación de la nueva izquierada en la Argentina 1955–1975”, dictado en esta Facultad por la Profesora María Cristina Tortti, en el año 2002.Facultad de Humanidades y Ciencias de la Educació

A new general relativistic magnetohydrodynamics code for dynamical spacetimes

We present a new numerical code that solves the general relativistic magneto-hydrodynamical (GRMHD) equations coupled to the Einstein equations for the evolution of a dynamical spacetime within a conformally-flat approximation. This code has been developed with the main objective of studying astrophysical scenarios in which both, high magnetic fields and strong gravitational fields appear, such as the magneto-rotational collapse of stellar cores, the collapsar model of GRBs, and the evolution of neutron stars. The code is based on an existing and thoroughly tested purely hydrodynamical code and on its extension to accommodate weakly magnetized fluids (passive magnetic-field approximation). These codes have been applied in the past to simulate the aforementioned scenarios with increasing levels of sophistication in the input physics. The numerical code we present here is based on high-resolution shock- capturing schemes to solve the GRMHD equations, which are cast in first-order, flux-conservative hyperbolic form, together with the flux constraint transport method to ensure the solenoidal condition of the magnetic field. Since the astrophysical applications envisaged do not deviate significantly from spherical symmetry, the conformal flatness condition approximation is used for the formulation of the Einstein equations; this has repeatedly shown to yield very good agreement with full general relativistic simulations of core- collapse supernovae and the evolution of isolated neutron stars. In addition, the code can handle several equations of state, from simple analytical expressions to microphysical tabulated ones. In this paper we present stringent tests of our new GRMHD numerical code, which show its ability to handle all aspects appearing in the astrophysical scenarios for which the code is intended, namely relativistic shocks, highly magnetized fluids, and equilibrium configurations of magnetized neutron stars. As an application, magneto- rotational core-collapse simulations of a realistic progenitor are presented and the results compared with our previous findings in the passive magnetic-field [email protected]; [email protected]

Quantum corrections to Higher-Dimensional Theories

This is a non-technical summary of the subtleties of quantum corrections on extra-dimensional theories: should one first renormalize and then mode expand, or first expand in four-dimensional modes and then renormalize?Comment: 9 pages, based on a talk at IRGAC 2006, Barcelon

Freshwater ecotoxicity assessment of pesticide use in crop production: Testing the influence of modeling choices

Pesticides help to control weeds, pests, and diseases contributing, therefore, to food availability. However, pesticide fractions not reaching the intended target may have adverse effects on the environment and the field ecosystems. Modeling pesticide emissions and the link with characterizing associated impacts is currently one of the main challenges in Life Cycle Assessment (LCA) of agricultural systems. To address this challenge, this study takes advantage of the latest recommendations for pesticide emission inventory and impact assessment and frames a suitable interface for those LCA stages and the related mass distribution of pesticide avoiding a temporal overlapping. Here, freshwater ecotoxicity impacts of the production of feed crops (maize, grass, winter wheat, spring barley, rapeseed, and peas) in Denmark were evaluated during a 3-year period, testing the effects of inventory modeling and the recent updates of the characterization method (USEtox). Potential freshwater ecotoxicity impacts were calculated in two functional units reflecting crop impact profiles per ha and extent of cultivation, respectively. Ecotoxicity impacts decreased over the period, mainly because of the reduction of insecticides use (e.g., cypermethrin). Three different emission modeling scenarios were tested; they differ on the underlining assumptions and data requirements. The main aspects influencing impact results are the interface between inventory estimates and impact assessment, and the consideration of intermedia processes, such as crop growth development and pesticide application method. Impact scores for AS2 were higher than RS and AS1, but the differences in the crops ranking was less apparent. On the other hand, the influence on the estimation of impacts for individual AIs was considerable and statistical differences were found in the impact results modeled in scenarios RS and AS2. Thereby indicating the effect of inventory models on ecotoxicity impact assessment.info:eu-repo/semantics/acceptedVersio

Continuous intraocular pressure monitoring in patients with obstructive sleep apnea syndrome using a contact lens sensor

Purpose To analyse nocturnal intraocular pressure (IOP) fluctuations in patients with obstructive sleep apnea syndrome (OSAS) using a contact lens sensor (CLS) and to identify associations between the OSAS parameters determined by polysomnographic study (PSG) and IOP changes. Method Prospective, observational study. Twenty participants suspected of having OSAS were recruited. During PSG study, IOP was monitored using a CLS placed in the eye of the patient. The patients were classified according to the apnea-hypopnea index (AHI) in two categories, severe (>30) or mild/moderate (<30) OSAS. We evaluated several parameters determined by the IOP curves, including nocturnal elevations (acrophase) and plateau times in acrophase (PTs) defined by mathematical and visual methods. Results The IOP curves exhibited a nocturnal acrophase followed by PTs of varying extents at which the IOP remained higher than daytime measurement with small variations. We found significant differences in the length of the PTs in patients with severe OSAS compared to those with mild/moderate disease (P = 0.032/P = 0.028). We found a positive correlation between PTs and OSAS severity measured by the total number of apneic events (r = 0.681/ 0.751 P = 0.004/0.001) and AHI (r = 0.674/0.710, P = 0.004/0.002). Respiratory-related arousal and oxygen saturation also were associated significantly with the IOP PT length. Conclusions Periods of nocturnal IOP elevation lasted longer in severe OSAS patients than those with mild/moderate OSAS and correlate with the severity of the disease. The length of the nocturnal PT is also associated to respiratory parameters altered in patients with OSAS

SDSSJ143244.91+301435.3: a link between radio-loud narrow-line Seyfert 1 galaxies and compact steep-spectrum radio sources?

We present SDSSJ143244.91+301435.3, a new case of radio-loud narrow line Seyfert 1 (RL NLS1) with a relatively high radio power (P1.4GHz=2.1x10^25 W Hz^-1) and large radioloudness parameter (R1.4=600+/-100). The radio source is compact with a linear size below ~1.4 kpc but, contrary to most of the RL NLS1 discovered so far with such a high R1.4, its radio spectrum is very steep (alpha=0.93) and not supporting a 'blazar-like' nature. Both the small mass of the central super-massive black-hole and the high accretion rate relative to the Eddington limit estimated for this object (3.2x10^7 Msun and 0.27, respectively, with a formal error of ~0.4 dex on both quantities) are typical of the class of NLS1. Through a modeling of the spectral energy distribution of the source we have found that the galaxy hosting SDSSJ143244.91+301435.3 is undergoing a quite intense star-formation (SFR=50 Msun y^-1) which, however, is expected to contribute only marginally (~1 per cent) to the observed radio emission. The radio properties of SDSSJ143244.91+301435.3 are remarkably similar to those of compact steep spectrum (CSS) radio sources, a class of AGN mostly composed by young radio galaxies. This may suggest a direct link between these two classes of AGN, with the CSS sources possibly representing the misaligned version (the so-called parent population) of RL NLS1 showing blazar characteristics.Comment: 14 pages, 7 figures, 4 tables, accepted for publication in MNRA