RBS1423 - a new QSO with relativistic reflection from an ionised disk

We present the analysis and results of a 20 ks XMM-Newton observation of RBS1423. X-ray spectral analysis is used to establish a significantly broadened relativistic iron K-alpha line from a highly ionised disk. A QSO at z=2.262 was considered to be the optical counterpart of this ROSAT Bright Survey X-ray source. Based on the improved XMM-Newton source position we identified a z=0.208 QSO as optical counterpart to RBS1423. The 0.2-12 keV X-ray luminosity of this radio-quiet QSO is 6x10^{44} erg/s. The XMM-EPIC spectra are well described by a power law with a significantly broadened iron K-alpha line. Disk line models for both Schwarzschild and Kerr black holes require hydrogen-like iron ions to fit the measured line profile. Significant ionisation of the reflection disk is confirmed by model fits with ionised disk models, resulting in an ionisation parameter xi~2000.Comment: 7 pages, 8 figures, accepted for publication in A&A (2 April 2007

SISTEMA MULTI-AGENTE DE APOYO AL ANÁLISIS DE UNA ACTIVIDAD COLABORATIVA DE UN VIDEOJUEGO

ResumenLa evolución de las tecnologías de la información y la comunicación ha permitido que los sistemas evolucionen, proporcionando mecanismos novedosos que apoyen a los usuarios en la realización de sus actividades, particularmente, en los Sistemas Colaborativos (SC), ya que este tipo software tiene como objetivo apoyar el trabajo en grupo, en donde los participantes llevan a cabo interacciones sociales y además se encuentran de manera presencial o distribuida, y trabajan de forma síncrona o asíncrona. Este software se caracteriza por proveer herramientas de comunicación, coordinación, colaboración y regulación y es deseable, que además cuente con mecanismos que permitan: adaptación al contexto de uso, medición de rendimiento de desempeño de usuarios, adaptación de interfaces, etc., a partir del análisis de la información generada durante el desarrollo de la actividad colaborativa. Este trabajo se enfoca en el análisis de las interacciones sociales en un videojuego colaborativo cuyo objetivo es "capturar y mantener una bandera". La actividad colaborativa en esta modalidad es muy dinámica y las interacciones sociales se llevan a cabo con una alta velocidad, por lo que en este trabajo se propone un software con tecnología multi-agente, que permita reproducir una actividad colaborativa e identificar las interacciones individuales y sociales realizadas.Palabra(s) Clave: Análisis de actividad, Sistemas colaborativos, Sistemas multi-agente, Videojuego. MULTI-AGENT SYSTEM TO SUPPORT THE ANALYSIS OF A COLLABORATIVE ACTIVITY OF A VIDEOGAMEAbstractThe evolution of information and communication technologies has allowed systems to evolve, as it provides novel mechanisms that support users in their activities. In particular, Collaborative Systems (CS), are a software type that aims to support group work. On these groups, users carry out social interactions, are located in the same or different place, and work in synchronous or asynchronous way. CSs are characterized by providing communication, coordination, collaboration and regulation tools. Nevertheless, it is desirable that CSs gather the necessary information from group activity, which allows them to: adapt to the context of use, measure performance of users, user interfaces. This work focuses on the analysis of social interactions in a collaborative video game aimed at "capturing and maintaining a flag". Collaborative activity in this modality is very dynamic and social interactions are carried out with a high speed, so in this work we propose a multi-agent system that allows to reproduce a collaborative activity and to identify the individual and social interactions.Keywords: Activity analysis, Collaborative Systems, Multi-agent systems, Video game

Movement velocity as a measure of exercise intensity in three lower limb exercises

The purpose of this study was to investigate the relationship between movement velocity and relative load in three lower limbs exercises commonly used to develop strength: Leg Press, Full Squat, and Half Squat. The percentage of one Repetition Maximum (%1RM) has typically been used as the main parameter to control resistance training, however more recent research has proposed movement velocity as an alternative. Fifteen participants performed a load progression with a range of loads until they reached their one repetition maximum (1RM). Maximum instantaneous velocity V max) and mean propulsive velocity (MPV) of the knee extension phase of each exercise were assessed. For all exercises, a strong relationship between V max and the %1RM was found: Leg Press (r2adj=0.96; 95% CI for slope is [-0.0244,-0.0258], p<0.0001), Full Squat (r2adj=0.94; 95% CI for slope is [-0.0144, -0.0139], p<0.0001), and Half Squat (r2adj=0.97; 95% CI for slope is [-0.0135, -0.00143], p<0.0001), and for MPV, Leg Press (r2adj=0.96; 95% CI for slope is [- 0.0169, -0.0175], p<0.0001, Full Squat (r2adj=0.95; 95% CI for slope is [-0.0136, -0.0128], p<0.0001), and Half Squat (r2adj=0.96; 95% CI for slope is [-0.0116, 0.0124], p<0.0001). The 1RM was attained with a MPV and Vmax of 0.21±0.06 ms-1 and 0.63±0.15 ms-1, 0.29±0.05 ms-1 and 0.89±0.17 ms-1, 0.33±0.05 ms-1, and 0.95±0.13 ms-1 for Leg Press, Full Squat and Half Squat respectively. Results indicate that it is possible to determine an exercise-specific %1RM by measuring movement velocity for that exercise

The Endoplasmic Reticulum Stress Response in Neuroprogressive Diseases: Emerging Pathophysiological Role and Translational Implications

The endoplasmic reticulum (ER) is the main cellular organelle involved in protein synthesis, assembly and secretion. Accumulating evidence shows that across several neurodegenerative and neuroprogressive diseases, ER stress ensues, which is accompanied by over-activation of the unfolded protein response (UPR). Although the UPR could initially serve adaptive purposes in conditions associated with higher cellular demands and after exposure to a range of pathophysiological insults, over time the UPR may become detrimental, thus contributing to neuroprogression. Herein, we propose that immune-inflammatory, neuro-oxidative, neuro-nitrosative, as well as mitochondrial pathways may reciprocally interact with aberrations in UPR pathways. Furthermore, ER stress may contribute to a deregulation in calcium homoeostasis. The common denominator of these pathways is a decrease in neuronal resilience, synaptic dysfunction and even cell death. This review also discusses how mechanisms related to ER stress could be explored as a source for novel therapeutic targets for neurodegenerative and neuroprogressive diseases. The design of randomised controlled trials testing compounds that target aberrant UPR-related pathways within the emerging framework of precision psychiatry is warranted

Superplasticity of Fe3Al(Cr)

The superplasticity of an Fe3Al based intermetallic alloy with 3 at.-% chromium has been investigated in the strain rate range 10-5-10-2 s-1 at test temperatures between 700 and 900°C. The composition of the iron aluminide was Fe–28Al–3Cr (at.-%) with additions of titanium and carbon. After thermomechanical processing the material possessed a coarse grained microstructure with an average grain size of 55 ± 10 μm. Strain rate exponents of 0·33≤m≤0.42 were recorded at strain rates of approximately 10-5-10-3 s-1 in the temperature range 750-900°C. Superplastic elongations of 350% and more were achieved. From thermal activation analysis of superplastic flow, an activation energy of 185 ± 10 kJ mol-1 was derived. This value is comparable to activation energies of superplastic flow in Fe3Al(Ti) alloys. However, in unalloyed Fe3Al the activation energy is higher, ~ 263 kJ mol-1. Optical microscopy showed grain refinement to ~ 30 ± 5 μm in size in superplastically strained tensile specimens. Transmission electron microscopy gave evidence of the formation of subgrains of 0·3–0·5 μm in size. Superplasticity in this iron aluminide is mainly attributed to viscous dislocation glide, controlled by solute drag in the transformed B2 lattice at the deformation temperatures. During superplastic deformation, subgrain formation and grain refinement in the gauge length were revealed. From this it is concluded that dynamic recrystallisation makes an important contribution to the deformation mechanism of superplastic flow in this material.Peer reviewe