297 research outputs found
Jet shapes in ep collisions at HERA
New measurements of the jet shape in ep collisions at HERA using the
k_T-cluster jet algorithm are presented.Comment: 7 pages, 3 figures; plenary talk given at the 3rd UK Phenomenology
Workshop on HERA Physics, Durham, UK, September 199
Heterologous viral expression systems in fosmid vectors increase the functional analysis potential of metagenomic libraries
The extraordinary potential of metagenomic functional analyses to identify activities of interest present in uncultured microorganisms has been limited by reduced gene expression in surrogate hosts. We have developed vectors and specialized E. coli strains as improved metagenomic DNA heterologous expression systems, taking advantage of viral components that prevent transcription termination at metagenomic terminators. One of the systems uses the phage T7 RNA-polymerase to drive metagenomic gene expression, while the other approach uses the lambda phage transcription anti-termination protein N to limit transcription termination. A metagenomic library was constructed and functionally screened to identify genes conferring carbenicillin resistance to E. coli. The use of these enhanced expression systems resulted in a 6-fold increase in the frequency of carbenicillin resistant clones. Subcloning and sequence analysis showed that, besides β-lactamases, efflux pumps are not only able contribute to carbenicillin resistance but may in fact be sufficient by themselves to convey carbenicillin resistance.España, Ministerio de Educación y Ciencia BIO2011-24003España, Ministerio de Educación y Ciencia CSD2007-000
Sistema embebido de procesamiento de vídeo para la realización de prácticas docentes
El Congreso TAEE'06, organizado por la Universidad Politécnica de Madrid,tuvo lugar entre el 12 de julio y el 15 de julio de 2006La realización, fomento y búsqueda de temas transversales en el proceso de enseñanza y aprendizaje, de manera que los contenidos curriculares se impregnen de ellos, es determinante para conseguir una docencia de calidad. Sin embargo, la estructura departamental universitaria no fomenta precisamente esta transversalidad. En un esfuerzo por mejorar las prácticas realizadas por Departamentos adscritos a la Escuela Superior de Ingenieros de Sevilla, se plantea el desarrollo de un entorno práctico para alumnos de la misma titulación y en asignaturas relacionadas con el diseño y desarrollo de sensores inteligentes y sistemas microprocesadores actuales y con los sistemas de percepción, visión y procesamiento de imágenes
Role of oxidative stress on the etiology and pathophysiology of Amyotrophic Lateral Sclerosis (ALS) and its relation with the enteric nervous system
Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease affecting motor neurons in the spinal cord, cerebral cortex, and medulla oblongata. Most patients present a clinical phenotype of classic ALS—with predominant atrophy, muscle weakness, and fasciculations—and survival of 3 to 5 years following diagnosis. In the present review, we performed a literature search to provide an update on the etiology and pathophysiological mechanisms involved in ALS. There are two types of ALS: the familial form with genetic involvement, and the sporadic form with a multifactorial origin. ALS pathophysiology is characterized by involvement of multiple processes, including oxidative stress, glutamate excitotoxicity, and neuroinflammation. Moreover, it is proposed that conditioning risk factors affect ALS development, such as susceptibility to neurodegeneration in motor neurons, the intensity of performed physical activity, and intestinal dysbiosis with involvement of the enteric nervous system, which supports the existing theories of disease generation. To improve patients’ prognosis and survival, it is necessary to further deepen our understanding of the etiopathogenesis of ALS
Predictive middle point modulation: a new modulation method for parallel active filters
When designing an Active filter, using a current-controlled voltage source inverter, there are two main tasks : to generate an appropiate reference, for nulling harmonic current and reactive power, ant, on the other side, to generate a switching pattern that permits to follow the reference as close as it can be done. Predictive Middle Point Modulation (PMPM) is a novel modulation technique, specially suited for Active Filters. This method is derived from predictive Dead-Beat controller, improving its dynamic response and current error. Simulation results confirm the validity of the proposed method. Experimental results will be provided in the final paper
Incremental SVM of controlled full-bridge rectifiers to allow IEC 61000-3-2 enforcement in power grid connection of modern elevator systems
The purpose of this paper is the study of different power converters and control techniques to allow power grid connection of modern vertical operation systems, verifying IEC 61000-3-2. We focus on the harmonic current analysis produced by the industrial standard AC/DC/3-phase AC machines system. Different AC/DC converters and control techniques have been compared to determine the one that minimizes low frequency harmonic current production. An incremental space vector modulator to regulate power grid current flow in electrical reference frame with a full-bridge controlled rectifier has been proven as the best power grid connection system. A general purpose test rig has been designed to evaluate the different power grid interface policies. Experimental results have been provided to show the effectiveness of the method
New controllability criteria for 3-phase 4-wire inverters applied to shunt active power filters
In shunt active filter applications, the 3-phase 4-wire topology is frequently used when dealing with unbalanced loads containing zero sequence components. A new design criteria for this topology is presented, based on the well-known existing method for the 3-phase 3-wire system. Simulation and experimental results confirms the validity of this new criteria, providing an easy method for the design of the reactive elements involved in a shunt active filter
Cell Expansion-Dependent Inflammatory and Metabolic Profile of Human Bone Marrow Mesenchymal Stem Cells
Stem cell therapy has emerged as a promising new area in regenerative medicine allowing the recovery of viable tissues. Among the many sources of adult stem cells, bone marrow-derived are easy to expand in culture via plastic adherence and their multipotentiality for differentiation make them ideal for clinical applications. Interestingly, several studies have indicated that MSCs expansion in vitro may be limited mainly due to cell aging related to the number of cell divisions in culture. We have determined that MSCs exhibit a progressive decline across successive passages in the expression of stem cell markers, in plasticity and in the inflammatory response, presenting low immunogenicity. We have exposed human MSCs after several passages to TLRs ligands and analyzed their inflammatory response. These cells responded to pro-inflammatory stimuli (i.e., NOS-2 expression) and to anti-inflammatory cytokines (i.e., HO1 and Arg1) until two expansions, rapidly declining upon subculture. Moreover, in the first passages, MSCs were capable to release IL1β, IL6 and IL8, as well as to produce active MMPs allowing them to migrate. Interestingly enough, after two passages, anaerobic glycolysis was enhanced releasing high levels of lactate to the extracellular medium. All these results may have important implications for the safety and efficacy of MSCs-based cell therapies
Measurements of top-quark pair single- and double-differential cross-sections in the all-hadronic channel in pp collisions at √s = 13 TeV using the ATLAS detector
Artículo escrito por un elevado número de autores, solo se referencian el que aparece en primer lugar, el nombre del grupo de colaboración, si le hubiere, y los autores pertenecientes a la UA
Reliability of streetscape audits comparing on‐street and online observations : MAPS-Global in 5 countries
Background: Microscale environmental features are usually evaluated using direct on-street observations. This study assessed inter-rater reliability of the Microscale Audit of Pedestrian Streetscapes, Global version (MAPS-Global), in an international context, comparing on-street with more efficient online observation methods in five countries with varying levels of walkability.
Methods: Data were collected along likely walking routes of study participants, from residential starting points toward commercial clusters in Melbourne (Australia), Ghent (Belgium), Curitiba (Brazil), Hong Kong (China), and Valencia (Spain). In-person on the street and online using Google Street View audits were carried out by two independent trained raters in each city. The final sample included 349 routes, 1228 street segments, 799 crossings, and 16 cul-de-sacs. Inter-rater reliability analyses were performed using Kappa statistics or Intraclass Correlation Coefficients (ICC).
Results: Overall mean assessment times were the same for on-street and online evaluations (22 ± 12 min). Only a few subscales had Kappa or ICC values < 0.70, with aesthetic and social environment variables having the lowest overall reliability values, though still in the "good to excellent" category. Overall scores for each section (route, segment, crossing) showed good to excellent reliability (ICCs: 0.813, 0.929 and 0.885, respectively), and the MAPS-Global grand score had excellent reliability (ICC: 0.861) between the two methods.
Conclusions: MAPS-Global is a feasible and reliable instrument that can be used both on-street and online to analyze microscale environmental characteristics in diverse international urban settings
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