On the local Lorentz invariance in N=1 supergravity

We discuss the local Lorentz invariance in the context of N=1 supergravity and show that a previous attempt to find explicit solutions to the Lorentz constraint in terms of $\gamma-$matrices is not correct. We improve that solution by using a different representation of the Lorentz operators in terms of the generators of the rotation group, and show its compatibility with the matrix representation of the fermionic field. We find the most general wave functional that satisfies the Lorentz constraint in this representation

Recent sediments of the Eume river: mineralogical and textural composition

[Resumen] Se analiza la granulometría, textura y mineralogía de sedimentos recogidos en los fondos de la ría de Ares, estuario y tramo final del río Eume. Texturalmente, las muestras se agrupan en francolimosas o francoarenosas y su distribución está defmida según las características dinámicas de la ría y las modificaciones realizadas por las obras de infraestructura. La mineralogía de la fracción arcilla es muy homogénea, con caolinita y filosilicatos 2: 1 dominantes, junto con pequeñas antidades de cuarzo y feldespato. El contenido en carbonatos es bajo, siempre menor del 30 %, destacando los porcentajes encontrados en el sondeo de la cola del embalse del Eume, de origen claramente antrópico. Textura y mineralogía son coherentes con el marco geológico del que proceden, excepto en la presencia de carbonatos y exceso de partículas finas con caolinita cristalina existentes en la cola del embalse del Eume. La distribución de las partículas, según su tamaño, obedece fundamentalmente a causas naturales, pero existen imponantes modificaciones relacionadas con el papel de barrera del embalse y las obras de infraestructura que han alterado la circulaci6n original en algunas zonas del estuario y desembocadura.[Abstract] A textural and mineralogical analysis is made to sediments sampled at the bottom of the Ría de Ares, estuarine and Eume river. Clay mineralogy is very similar for all the samples and consists of kaolinite and 2: 1 phyllosilicates with small amounts of quartz and fe'ldspar. The percentage of carbonates is small, always less than 30 o/o. There should be pointed out the values found in the Eume reservoir core, with a clear antropic origino Texture and mineralogy are coherent with the geology of the basin they come from, excepting the carbonates and fine particle excess with cristaline caolinite in the Eume reservoir core. Size grain distribution is due to the dinamic characteristics of the ría, but there are important rnodifications related to the reservoir, that acts as a barrier, and the constructions in the lower part of the river that have changed the original circulation in sorne areas of the ría

Independent Component Analysis to Detect Clustered Microcalcification Breast Cancers

The presence of clustered microcalcifications is one of the earliest signs in breast cancer detection. Although there exist many studies broaching this problem, most of them are nonreproducible due to the use of proprietary image datasets. We use a known subset of the currently largest publicly available mammography database, the Digital Database for Screening Mammography (DDSM), to develop a computer-aided detection system that outperforms the current reproducible studies on the same mammogram set. This proposal is mainly based on the use of extracted image features obtained by independent component analysis, but we also study the inclusion of the patient's age as a nonimage feature which requires no human expertise. Our system achieves an average of 2.55 false positives per image at a sensitivity of 81.8% and 4.45 at a sensitivity of 91.8% in diagnosing the BCRP_CALC_1 subset of DDSM

Superevolution

Usually, in supersymmetric theories, it is assumed that the time-evolution of states is determined by the Hamiltonian, through the Schr\"odinger equation. Here we explore the superevolution of states in superspace, in which the supercharges are the principal operators. The superevolution equation is consistent with the Schr\"odinger equation, but it avoids the usual degeneracy between bosonic and fermionic states. We discuss superevolution in supersymmetric quantum mechanics and in a simple supersymmetric field theory.Comment: 23 page

Corona-Australis DANCe I. Revisiting the census of stars with Gaia-DR2 data

Context. Corona-Australis is one of the nearest regions to the Sun with recent and ongoing star formation, but the current picture of its stellar (and substellar) content is not complete yet. Aims. We take advantage of the second data release of the Gaia space mission to revisit the stellar census and search for additional members of the young stellar association in Corona-Australis. Methods. We applied a probabilistic method to infer membership probabilities based on a multidimensional astrometric and photometric data set over a field of 128 deg(2) around the dark clouds of the region. Results. We identify 313 high-probability candidate members to the Corona-Australis association, 262 of which had never been reported as members before. Our sample of members covers the magnitude range between G greater than or similar to 5 mag and G less than or similar to 20 mag, and it reveals the existence of two kinematically and spatially distinct subgroups. There is a distributed "off-cloud" population of stars located in the north of the dark clouds that is twice as numerous as the historically known "on-cloud" population that is concentrated around the densest cores. By comparing the location of the stars in the HR-diagram with evolutionary models, we show that these two populations are younger than 10 Myr. Based on their infrared excess emission, we identify 28 Class II and 215 Class III stars among the sources with available infrared photometry, and we conclude that the frequency of Class II stars (i.e. "disc-bearing" stars) in the on-cloud region is twice as large as compared to the off-cloud population. The distance derived for the Corona-Australis region based on this updated census is d = 149.4(-0.4)(+0.4) pc, which exceeds previous estimates by about 20 pc. Conclusions. In this paper we provide the most complete census of stars in Corona-Australis available to date that can be confirmed with Gaia data. Furthermore, we report on the discovery of an extended and more evolved population of young stars beyond the region of the dark clouds, which was extensively surveyed in the past

Empleo de materiales secundarios como materia prima de nuevos tipos de cementos

The present paper is a comparative study of some characteristics of new belite cements obtained from two kind of wastes, which were used as secondary raw materials: fly ash (FA), of low CaO content, from coal combustion, and ash from incineration of municipal solid waste (MSWIA). Cements were synthesised in a range of temperature between 700°C and 900°C from MSWIA and FA, which were previously activated by hydrothermal treatment at 200°C The evolution of cemented phases with the heating temperature was followed by X-ray diffraction (XRD). The results were compared with those obtained from heating the starting FA and MSWIA without the previous hydrothermal treatment. The degree of hydration was quantitatively evaluated by the combined water content, determined from thermogravimetric analyses, during a period of 28 days or 200 days from mixing depending of hydration kinetics of each cement.Este trabajo es un estudio comparativo de algunas de las características de nuevos cementos belíticos, obtenidos a partir de dos tipos de residuos, como materia prima secundaria: cenizas volantes (CV) de bajo contenido en cal, procedentes de la combustión del carbón y cenizas procedentes de la incineración de residuos sólidos urbanos (CIRSU). Los cementos fueron sintetizados en un rango de temperaturas comprendido entre 700°C y 900°C después de un tratamiento hidrotermal de la CV y CIRSU a 200°C La evolución de las fases cementicias, con la temperatura de calentamiento, fue estudiada por difracción de rayos X (DRX). Los resultados fueron comparados con aquellos obtenidos, directamente, por calentamiento de los residuos, sin un tratamiento hidrotermal previo de los mismos. El grado de hidratación fue cuantitativamente evaluado, por medio del análisis termogravimétrico, a partir del agua combinada de los cementos hidratados durante un período de 28 días o 200 días, dependiendo de la cinética de hidratación de cada cemento

El mundo funerario Tardorromano en Baelo Claudia. Novedades de las intervenciones arqueológicas del 2005 en la muralla oriental

The first results of an archaeological excavation carried out in the Baelo Claudia city wall are shown. The area is the one between the so called “Puerta de Carteia” ant the 4th tower . Six stratigraphic soundings have been developed, fi ve of them outside the wall and only one inside. A late roman cementery has been discovered in the upper part of the sequence, dating back to the V-VII c. AD. An archaeological, paleoanthropologic, paleopathologic study of the skeletals, and the funeral ritual has been carried out. Eight tombs have been digged up, three double and four single, containing seven adults and four children. Two tombs show an interesting disposition of skeletal remains, some of them reusing the graves, and a newly born with an anomalous position. Also, animals phalanges could have been placed in the children tombs as amulets, as well as a marine shell probably as a symbol of a fi sherman. All of adults present skeletal stress work and nutritional indicators.Se presentan los primeros resultados de una actuación arqueológica realizada en la muralla oriental de Baelo Claudia, comprendida entre la denominada Puerta de Carteia y la torre 4. Se han realizado seis sondeos estratigráfi cos, cinco extramuros y uno al interior de la cinta muraria, en los cuales se ha documentado una necrópolis tardorromana (ss. V-VII d.C.) en la parte superior de la secuencia estratigráfi ca. Se exponen los resultados preliminares del estudio arqueológico, paleoantropológico y paleopatológico, y del ritual funerario, de los individuos hallados en las ocho tumbas excavadas. El total de individuos exhumados fue de once (siete adultos y cuatro infantiles), hallándose unos interesantes rituales de reutilización de las tumbas, un recién nacido en una posición “anómala” y falanges de animales depositadas, quizás como amuletos, así como una caracola como ajuar de un posible almadrabero. Tanto en hombres como en mujeres se advierten marcadores paleoocupacionales que muestran que realizaban una actividad laboral intensa