Propiedades de Calidad de Servicio en el Descubrimiento de Recursos Grid

Uno de los problemas abiertos en el contexto de las Arquitecturas Orientadas a Servicios es del descubrimiento de recursos y/o servicios adecuados para llevar a cabo una tarea determinada. Los proveedores de información Grid básicamente ofrecen información funcional sobre los recursos Grid que monitorizan, por lo que los modelos de información Grid básicamente representan esta información sintáctica, y los consumidores de información Grid usan normalmente dichas propiedades funcionales para seleccionar recursos. En la práctica, muchos trabajos se reinician debido a fallos en los recursos, aunque existen iniciativas que tratan de usar técnicas aisladas para manejar algunas propiedades de calidad de servicio. En el presente artículo se propone un nuevo enfoque para modelar recursos Grid junto con propiedades de calidad de servicio. Por un lado, este modelo está basado en una ontología desarrollada para integrar los modelos existentes tanto a nivel de representación de información Grid como de calidad de servicio en general. Por otro lado, también propone la creación de un sistema de medida - actualmente en desarrollo - para algunas propiedades de calidad de servicio (disponibilidad, rendimiento y fiabilidad)

Centinela: A human activity recognition system based on acceleration and vital sign data

This paper presents Centinela, a system that combines acceleration data with vital signs to achieve highly accurate activity recognition. Centinela recognizes five activities: walking, running, sitting, ascending, and descending. The system includes a portable and unobtrusive real-time data collection platform, which only requires a single sensing device and a mobile phone. To extract features, both statistical and structural detectors are applied, and two new features are proposed to discriminate among activities during periods of vital sign stabilization. After evaluating eight different classifiers and three different time window sizes, our results show that Centinela achieves up to 95.7% overall accuracy, which is higher than current approaches under similar conditions. Our results also indicate that vital signs are useful to discriminate between certain activities. Indeed, Centinela achieves 100% accuracy for activities such as running and sitting, and slightly improves the classification accuracy for ascending compared to the cases that utilize acceleration data only

Clinicopathologic study on the effects of Glyphosate (Roundup?) at sublethal levels in a murine experimental model

P?ginas 17-24Recurso Electr?nicoEn Colombia, los pesticidas a base de glifosato se usan para el control de malezas en la agricultura y erradicaci?n de cultivos il?citos. Sin embargo, los efectos t?xicos en animales y humanos expuestos a dosis subletales son desconocidos. Este estudio evalu? los efectos cl?nico-patol?gicos de dietas con 7,5 ppm y 15 ppm glifosato en ratones Mus musculus gestantes, usando el herbicida Roundup?. Se registr? el peso corporal de las hembras, de sus cr?as, y la viabilidad de las camadas diariamente. Las lesiones macrosc?picas e histopatol?gicas en el h?gado, ri??n, ?tero y cerebro se determinaron a trav?s de necropsias en los d?as 5, 30 y 45 despu?s de la exposici?n, adem?s de los ?ndices org?nicos hep?tico y cardiaco. No hubo diferencias significativas en el peso corporal, el tama?o y la viabilidad de las camadas a ninguna de las dosis evaluadas. Se observ? congesti?n y aumento en el tama?o del h?gado, ri??n y bazo, despu?s de 5 d?as de exposici?n, sugiriendo un proceso de desintoxicaci?n. A 30 y 45 d?as, no se observaron signos cl?nicos ni lesiones patol?gicas atribuibles al glifosato; sin embargo, un aumento en el tama?o de los hepatocitos, con contenido vacuolar y granular de aspecto protein?ceo indican un efecto evidente, aunque sutil del Roundup? a dosis subletales con posible adaptabilidad org?nica. Se concluye que el consumo de alimento con 7,5 ppm y 15 ppm de glifosato durante 5, 30 y 45 d?as causa alteraciones sutiles de toxicidad en ratones durante la gestaci?n, la lactancia y el posparto, pero no en sus camadas.ABSTRACT. In Colombia, glyphosate-based pesticides are used for weed control in agriculture and eradication of illicit crops; however, the toxic effects in animals and humans exposed to sublethal doses are unknown. This study evaluated the clinical and pathological changes induced by diets containing glyphosate at 7,5 ppm and 15 ppm in pregnant mice Mus musculus, using the herbicide Roundup ?. The body-weight of pregnant females and offspring and the viability of litters were recorded daily. Gross and microscopic lesions in liver, kidney, uterus and brain were determined at necropsies performed at 5, 30 and 45 days post- exposure, in addition to the liver and heart organic indexes. No significant differences were found in body weight, size and viability of litters at any dose. Organs such as the liver, kidney and spleen were enlarged and congested at day 5 post exposure, suggesting a detoxification process. At 30 and 45 days, no clinical signs or pathological lesions attributed to glyphosate were found. However, there was an increase in the hepatocyte size, with vacuolar and granular cytoplasm and proteinaceus-like content, suggesting a subtle effect of sublethal doses of Roundup ?, with possible organ adaptability. We conclude that the consumption of food containing 7.5 ppm and 15 ppm of glyphosate for 5, 30 and 45 days, cause subtle toxic alterations in mice during pregnancy, lactation and postpartum, but not in their litters

Solar Energetic Particle Spectral Breaks

The five large solar particle events during October–November 2003 presented an opportunity to test shock acceleration models with in-situ observations. We use solar particle spectra of H to Fe ions, measured by instruments on ACE, SAMPEX, and GOES-11, to investigate the Q/M-dependence of spectral breaks in the 28 October 2003 event. We find that the break energies scale as (Q/M)^b with b ≈ 1.56 to 1.75, somewhat less than predicted. We also conclude that SEP spectra >100 MeV/nucleon are best fit by a double power-law shape. ©2005 American Institute of Physic

New Measurement of the Cosmic-Ray Positron Fraction from 5 to 15 GeV

We present a new measurement of the cosmic-ray positron fraction at energies between 5 and 15 GeV with the balloon-borne HEAT-pbar instrument in the spring of 2000. The data presented here are compatible with our previous measurements, obtained with a different instrument. The combined data from the three HEAT flights indicate a small positron flux of non-standard origin above 5 GeV. We compare the new measurement with earlier data obtained with the HEAT-e+- instrument, during the opposite epoch of the solar cycle, and conclude that our measurements do not support predictions of charge sign dependent solar modulation of the positron abundance at 5 GeV.Comment: accepted for publication in PR

Observations of the longitudinal spread of solar energetic particle events in solar cycle 24

With the twin STEREO spacecraft, significantly separated from L1-based satellites such as ACE, simultaneous multi-point measurements of solar energetic particle (SEP) events can be made for H-Fe ions from a few hundred keV/nuc to over 100 MeV/nuc and for electrons from tens to hundreds of keV. These observations allow studies of the longitudinal characteristics of SEP events to advance beyond statistical analysis of single point measurements. Although there have been few large SEP events thus far in cycle 24, there have been a number of smaller events that have been detected by more than one spacecraft. The composition of these SEP events, as indicated by the H/He and Fe/O abundance ratios, shows a dependence on longitudinal distance from the solar source in some events, at times with ratios varying by an order of magnitude. However, these variations are not organized by either the speed or width of the associated coronal mass ejections

The Charge-to-Mass Dependence of Solar Energetic Particle Spectral Breaks

Measurements of the energy spectra of SEP events over a broad energy range (~0.1 to 100 MeV/nuc) show that all large SEP events have spectral beaks organized by the charge-to-mass ratio (Q/M) of the ions. In this paper we present preliminary results of a multi-spacecraft study of the Q/M-dependence of spectral breaks in 11 SEP events and investigate whether the deduced Q/M dependence is correlated with other characteristics of the events