The localization of phonons in ion traps with controlled quantum disorder

We show that the vibrations of a chain of trapped ions offer an interesting route to explore the physics of disordered quantum systems. By preparing the internal state of the ions in a quantum superposition, we show how the local vibrational energy becomes a stochastic variable, its statistical properties inherited from the underlying quantum parallelism of the internal state. We describe a minimally perturbing measurement of the resonance fluorescence, which allows us to study effects such as Anderson localization without the need for ground-state cooling or individual addressing and thus paves the way for high-temperature ion experiments

Control comportamental de un robot lego nxt orientado para tareas de busqueda y evasion de obstaculos

This paper shows the design of a reactive architecture for a robot using LEGO NXT drawing Brooks’ approach for the development of searching tasks and avoiding obstacles in a dynamic environment. One of the most important aspects in this work, is the implementation of two primary mechanisms of coordination mentioned by Brooks, inhibition and suppression. Reactive paradigm is one of the approaches used in the robotics field. This reactive paradigm emerged in the late 80´s as a result of researchers such as Brooks and Arkin´s work at Massachusetts Institute of Technology MIT, their proposal is based on the creation of strongly coupled systems of perception and action, which enables them to interact in dynamic environments. Subsumed Architecture SA is also one of the approaches based on this paradigm in that it proposes a parallel architecture layered behavioral, which runs asynchronously but in many cases, they have common goalsEl paradigma reactivo es uno de los enfoques más utilizados en el campo de la robótica. Surge a finales de los años 80 como resultado del trabajo de algunos investigadores como Brooks y Arkin en el MIT, su propuesta está basada en la creación de sistemas que acoplan fuertemente la percepción y la acción, lo que los capacita para interactuar con entornos dinámicos. La arquitectura subsumida es una de los enfoques basados en este paradigma y propone una arquitectura paralela dividida en capas comportamentales, las cuales se ejecutan asincrónicamente pero que en muchos casos poseen objetivos en común. El presente trabajo muestra el diseño de una arquitectura reactiva para un robot LEGO NXT utilizando el enfoque de Brooks para el desarrollo de tareas de búsqueda y evasión de obstáculos en un entorno dinámico, uno de los aspectos más relevantes en este trabajo es la implementación de los dos mecanismos primarios de coordinación mencionados por Brooks, inhibición y supresión

CCR5Δ32 variant and cardiovascular disease in patients with rheumatoid arthritis: a cohort study

Introduction The aim of our study was to analyze the influence of the CCR5Δ32 polymorphism in the risk of cardiovascular (CV) events and subclinical atherosclerosis among patients with rheumatoid arthritis (RA). Methods A total of 645 patients fulfilling the American Rheumatism Association 1987 revised classification criteria for RA were studied. Patients were genotyped for the CCR5 rs333 polymorphism using predesigned TaqMan assays. Also, HLA DRB1 genotyping was performed using molecular-based methods. Carotid intima-media thickness, flow-mediated endothelium-dependent dilatation (FMD) and endothelium-independent vasodilatation, which were used as surrogate markers of subclinical atherosclerosis, were measured in a subgroup of patients with no clinical CV disease. Results A lower frequency of carriers of the CCR5Δ32 allele among patients with CV events (3.4% versus 11.3%, P = 0.025, odds ratio 0.28, 95% confidence interval (95% CI) 0.06 to 0.89) was observed. However, after adjusting for gender, age at time of RA diagnosis, and the presence of shared epitope, rheumatoid factor and classic CV risk factors in the Cox regression analysis, this reduction of CV events in CCR5Δ32 allele carriers was slightly outside the range of significance (P = 0.097; hazard ratio 0.37 (95% CI 0.12 to 1.19)). Carriers of the CCR5Δ32 deletion also showed higher FMD values than the remaining patients (CCR5/CCR5Δ32 patients: 7.03% ± 6.61% versus CCR5/CCR5 patients: 5.51% ± 4.66%). This difference was statistically significant when analysis of covariance was performed (P = 0.024). Conclusions Our results show a potential influence of the CCR5Δ32 deletion on the risk of CV disease among patients with RA. This may be due to a protective effect of this allelic variant against the development of vascular endothelial dysfunction

IAA : Información y actualidad astronómica (30)

Sumario : Habitabilidad en el Universo.-- El imán de la Vía Láctea.-- El estudio del Universo frío.-- DECONSTRUCCIÓN Y otros ENSAYOS. Johannes Kepler.-- EL “MOBY DICK” DE... Matilde Fernández (IAA-CSIC).-- HISTORIAS DE ASTRONOMÍA. La noche de Noli.-- ACTUALIDAD.-- ENTRE BASTIDORES.-- CIENCIA: PILARES E INCERTIDUMBRES : Núcleos activos de galaxias.-- ACTIVIDADES IAA.N

Lack of association between TLR4 rs4986790 polymorphism and risk of cardiovascular disease in patients with rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory disease associated with increased cardiovascular (CV) mortality. Toll-like receptor-4 (TLR4) activates the innate immune response via NF-kB pathway and mitogen-activated protein kinase signaling, leading to expression of proinflammatory cytokines and chemokines. The G allele of TLR4 rs4986790 (+896A > G, Asp299Gly) gene polymorphism has been implicated in reduction of risk of atherosclerosis. In this study, 1481 RA patients fulfilling the 1987 American College of Rheumatology (ACR) criteria were genotyped for the rs4986790 TLR4 variant to determine the influence of this variant in the risk of CV events in these patients. Also, HLA-DRB1 status was determined using molecular based methods. Moreover, potential influence of rs4986790 variant in the development of subclinical atherosclerosis was assessed in a subgroup of RA patients with no history of CV events by the measurement of surrogate markers of subclinical atherosclerosis. No statistically significant differences in allele or genotype frequencies for the rs4986790 variant between RA patients who experienced CV events or not were found. Likewise, no significant association between this gene variant and any of the surrogate markers of subclinical atherosclerosis was found. In summary, results in our study do not support the hypothesis that the rs4986790 (+896A > G, Asp299Gly) TLR4 variant may influence predisposition for subclinical atherosclerosis and clinically evident CV disease in RA patients

Genetic Markers of Cardiovascular Disease in Rheumatoid Arthritis

Cardiovascular (CV) disease is the most common cause of premature mortality in patients with rheumatoid arthritis (RA). It is the result of an accelerated atherosclerotic process. Both RA and atherosclerosis are complex polygenic diseases. Besides traditional CV risk factors and chronic inflammation, a number of studies have confirmed the role of genetic factors in the development of the atherogenesis observed in RA. In this regard, besides a strong association between the HLA-DRB1∗04 shared epitope alleles and both endothelial dysfunction, an early step in the atherosclerotic process, and clinically evident CV disease, other polymorphisms belonging to genes implicated in inflammatory and metabolic pathways, located inside and outside the HLA region, such as the 308 variant (G > A, rs1800629) of the TNFA locus, the rs1801131 polymorphism (A > C; position + 1298) of the MTHFR locus, or a deletion of 32 base pairs on the CCR5 gene, seem to be associated with the risk of CV disease in patients with RA. Despite considerable effort to decipher the genetic basis of CV disease in RA, further studies are required to better establish the genetic influence in the increased risk of CV events observed in patients with RA

CARD8 rs2043211 (p.C10X) polymorphism is not associated with disease susceptibility or cardiovascular events in Spanish rheumatoid arthritis patients

Rheumatoid arthritis (RA) is a complex polygenic inflammatory disease associated with accelerated atherosclerosis, which is the main cause of increased cardiovascular (CV) morbidity and mortality in RA patients. CARD8 is a constituent of inflammasome, which regulates interleukin 1-beta production, and has been associated with a worse disease course in early RA. One thousand six hundred twenty-one patients fulfilling the 1987 ACR classification criteria for RA and 1300 matched controls, were genotyped for the CARD8 rs2043211 (30T > A, p.C10X) single-nucleotide polymorphism (SNP) using predesigned TaqMan SNP genotyping assay. The genotyping success rate in our study was greater than 94%. We assessed CARD8 rs2043211 gene polymorphism results in 1530 Spanish RA patients in whom information on CV disease and CV risk factors was available at the time of the study. Also, a subgroup of patients with no history of CV events (n = 276) was assessed for the potential influence of the rs2043211 variant in the development of subclinical atherosclerosis, by measurement of carotid intima-media thickness (IMT) and presence of carotid plaques. No statistically significant differences in allele or genotype frequencies for the rs2043211 CARD8 gene variant between patients with RA and controls were seen. Similarly, CARD8 rs2043211 (30T > A, p.C10X) SNP did not influence the development of CV events or the risk of CV events throughout the time. Likewise, no significant association between this gene variant and carotid IMT or the presence of plaques was found. In summary, our results do not support a role of the CARD8 rs2043211 gene variant in susceptibility to RA or in the development of CV disease in patients with RA

Modelo cinemático de un robot móvil implementado con LEGO NXT para un sistema de localización Indoor diseñado en LABVIEW

El estudio de la cinemática de una plataforma móvil establece el desarrollo de modelos matemáticos que permite conocer el comportamiento de las velocidades relacionadas con las características de los motores usados en el móvil. Por lo general, en la gran cantidad de artículos consultados, el proceso de validación de los modelos no son especificados ni detallados pero la importancia de su implementación permitiría conocer su comportamiento real y los errores sistemáticos que están presentes. Este trabajo presenta el proceso de validación del modelo cinemático y odométrico para una plataforma diferencial construida con LEGO NXT que permita la implementación de algoritmos de planificación de rutas y sistemas de navegación en zonas desconocidos dentro de un entorno cerrado, que son necesarios para el desarrollo de un sistema de localización para un sistema multirobot