Gloria Anzaldúa’s Mexican Genealogy: From Pelados and Pachucos to New Mestizas

This essay examines Gloria Anzaldúa’s critical appropriation of two Mexican philosophers in the writing of Borderlands/La Frontera: Samuel Ramos and Octavio Paz. We argue that although neither of these authors is cited in her seminal work, Anzaldúa had them both in mind through the writing process and that their ideas are present in the text itself. Through a genealogical reading of Borderlands/La Frontera, and aided by archival research, we demonstrate how Anzaldúa’s philosophical vision of the “new mestiza” is a critical continuation of the broader tradition known as la filosofía de lo mexicano, which flourished during a golden age of Mexican philosophy (1910–1960). Our aim is to open new directions in Latinx and Latin American philosophy by presenting Anzaldúa’s Borderlands/La Frontera as a profound scholarly encounter with two classic works of Mexican philosophy, Ramos’ Profile of Man and Culture in Mexico and Paz’s The Labyrinth of Solitude

Inmigración ilegal, aplicación de la ley en la frontera y salarios relativos: elementos de juicio sobre las detenciones en la frontera entre EE.UU. y México

(Disponible en idioma inglés únicamente) En este trabajo se analizan los factores determinantes de la inmigración ilegal hacia EE. UU. desde México desde 1976 hasta 1995. El principal problema de este trabajo empírico es que las observaciones no son de la cantidad de personas que tratan de entrar ilegalmente a EE. UU. , sino del número de las detenidas en el intento de cruzar ilícitamente la frontera entre EE. UU. y México. Basándonos en un modelo simple de la decisión individual de emigrar, sugerimos la existencia de una función de detenciones, que expresa el número de detenciones realizadas en la frontera entre México y EE. UU. como función del número de intentos ilícitos de cruzar la frontera y el grado en que el gobierno estadounidense aplica la ley en la frontera.

Broad band time-resolved E_{p,i}--L_{iso} correlation in GRBs

We report results of a systematic study of the broad band (2--2000 keV) time resolved prompt emission spectra of a sample of gamma-ray bursts (GRBs) detected with both Wide Field Cameras on board the \sax\ satellite and the \batse\ experiment on board CGRO. In this first paper, we study the time-resolved dependence of the intrinsic peak energy $E_{p,i}$ of the $E F(E)$ spectrum on the corresponding isotropic bolometric luminosity $L_{\rm iso}$. The $E_{p,i}$--$L_{\rm iso}$ relation or the equivalent relation between $E_{p,i}$ and the bolometric released energy $E_{iso}$, derived using the time averaged spectra of long GRBs with known redshift, is well established, but its physical origin is still a subject of discussion. In addition, some authors maintain that these relations are the result of instrumental selection effects. We find that not only a relation between the measured peak energy $E_p$ and the corresponding energy flux, but also a strong $E_{p,i}$ versus $L_{\rm iso}$ correlation are found within each burst and merging together the time resolved data points from different GRBs. We do not expect significant instrumental selection effects that can affect the obtained results, apart from the fact that the GRBs in our sample are sufficiently bright to perform a time-resolved spectroscopy and that they have known redshift. If the fundamental physical process that gives rise to the GRB phenomenon does not depend on its brightness, we conclude that the found $E_{p,i}$ versus $L_{\rm iso}$ correlation within each GRB is intrinsic to the emission process, and that the correlations discovered by Amati et al. and Yonetoku et al. are likely not the result of selection effects. We also discuss the properties of the correlations found.Comment: 27 pages,4 tables, 7 figure, accepted for publication in The Astrophysical Journa

An upscattering spectral formation model for the prompt emission of Gamma-Ray Bursts

We propose a model for the spectral formation of Gamma Ray Burst (GRB) prompt emission, where the phenomenological Band's function is usually applied to describe the GRB prompt emission. We suggest that the GRB prompt emission is mainly a result of two upscattering processes. The first process is the Comptonization of relatively cold soft photons of the star off electrons of a hot shell of plasma of temperature T_e of the order of 10^{9} K (or kT_e~100 keV) that moves sub-relativistically with the bulk velocity V_b substantially less than the speed of light c. In this phase, the Comptonization parameter Y is high and the interaction between a blackbody-like soft seed photon population and hot electrons leads to formation of a saturated Comptonization spectrum modified by the sub-relativistic bulk outflow. The second process is an upscattering of the previously Comptonized spectrum by the plasma outflow once it becomes relativistic. This process gives rise to the high-energy power-law component above the peak in the EF(E)-diagram where F(E) is the energy flux. The latter process can be described by a convolution of the Comptonized spectrum with a broken-power-law Green function. Possible physical scenarios for this second upscattering process are discussed. In the framework of our model, we give an interpretation of the Amati relation between the intrinsic spectral peak photon energy and radiated energy or luminosity, and we propose a possible explanation of the GRB temporal variability.Comment: 27 pages, 8 figures, accepted for publication in the Astrophysical Journa

Average power density spectrum of long GRBs detected with BeppoSAX/GRBM and with Fermi/GBM

From past experiments the average power density spectrum (PDS) of GRBs with unknown redshift was found to be modelled from 0.01 to 1 Hz with a power-law, f^(-alpha), with alpha broadly consistent with 5/3. Recent analyses of the Swift/BAT catalogue showed analogous results in the 15-150 keV band. We carried out the same analysis on the bright GRBs detected by BeppoSAX/GRBM and Fermi/GBM. The BeppoSAX/GRBM data, in the energy range 40-700 keV and with 7.8 and 0.5-ms time resolutions, allowed us to explore for the first time the average PDS at very high frequencies (up to 1 kHz) and reveal a break around 1-2 Hz, previously found in CGRO/BATSE data. The Fermi/GBM data, in the energy band 8-1000 keV, allowed us to explore for the first time the average PDS within a broad energy range. Our results confirm and extend the energy dependence of the PDS slope, according to which harder photons have shallower PDS.Comment: 13 pages, 9 figures, accepted to MNRA

Measuring the efficiency in Spanish municipal refuse collection services

The objective of this study is to analyse the technical or productive efficiency of the refuse collection services in 75 municipalities located in the Spanish region of Catalonia. The analysis has been carried out using various techniques. Firstly we have calculated a deterministic parametric frontier, then a stochastic parametric frontier, and finally, various non-parametric approaches (DEA and FDH). Concerning the results, these naturally differ according to the technique used to approach the frontier. Nevertheless, they have an appearance of solidity, at least with regard to the ordinal concordance among the indices of efficiency obtained by the different approaches, as is demonstrated by the statistical tests used. Finally, we have attempted to search for any relation existing between efficiency and the method (public or private) of managing the services. No significant relation was found between the type of management and efficiency indices- L'objectiu d'aquest estudi és analitzar l'eficiència tècnica o productiva dels serveis de recollida d'escombraries a 75 municipis de Catalunya. L'anàlisi s'ha portat a terme utilitzant varies tècniques. En primer lloc, hem calculat una frontera paramètrica determinística, després una frontera paramètrica estocàstica, i finalment, varies aproximacions no-paramètriques (DEA i FDH). Pel que fa als resultats, aquests naturalment difereixen en funció de la tècnica utilitzada per aproximar la frontera. No obstant això, guarden una aparença de solidesa, al menys pel que fa referència a la concordança ordinal entre els índexs d'eficiència obtinguts per les diferents aproximacions, com mostren els tests estadístics utilitzats. Finalment, hem intentat buscar si existeix alguna relació entre l'eficiència i el mètode (públic o privat) de gestionar els serveis, no trobant-se cap relació significativa entre el tipus de gestió i els índexs d'eficiència