998 resultados para space charge
Resumo:
El déficit existente a nuestro país con respecto a la disponibilidad de indicadores cuantitativos con los que llevar a término un análisis coyuntural de la actividad industrial regional ha abierto un debate centrado en el estudio de cuál es la metodología más adecuada para elaborar indicadores de estas características. Dentro de este marco, en este trabajo se presentan las principales conclusiones obtenidas en anteriores estudios (Clar, et. al., 1997a, 1997b y 1998) sobre la idoneidad de extender las metodologías que actualmente se están aplicando a las regiones españolas para elaborar indicadores de la actividad industrial mediante métodos indirectos. Estas conclusiones llevan a plantear una estrategia distinta a las que actualmente se vienen aplicando. En concreto, se propone (siguiendo a Israilevich y Kuttner, 1993) un modelo de variables latentes para estimar el indicador de la producción industrial regional. Este tipo de modelo puede especificarse en términos de un modelo statespace y estimarse mediante el filtro de Kalman. Para validar la metodología propuesta se estiman unos indicadores de acuerdo con ella para tres de las cuatro regiones españolas que disponen d¿un Índice de Producción Industrial (IPI) elaborado mediante el método directo (Andalucía, Asturias y el País Vasco) y se comparan con los IPIs publicados (oficiales). Los resultados obtenidos muestran el buen comportamiento de l¿estrategia propuesta, abriendo así una línea de trabajo con la que subsanar el déficit al que se hacía referencia anteriormente
Resumo:
Dans le cadre de la collaboration entre le Registre valaisan des tumeurs (RVsT) de l'Observatoire valaisan de la santé (OVS) et le Département valaisan d'oncologie (DVO), il a été décidé de faire une étude sur l'épidémiologie et la prise en charge du cancer du sein en Valais de 2008 à 2010. Le but de cette étude est de décrire la fréquence, les modes de présentation, les traitements et la survie à 1 et 2 ans du cancer du sein en Valais.
Resumo:
Les carences en compétences en santé touchent principalement certaines populations à risques en limitant l'accès aux soins, l'interaction avec les soignants et l'autoprise en charge. L'utilisation systématique d'instruments de dépistage n'est pas recommandée et les interventions préconisées en pratique consistent plutôt à diminuer les obstacles entravant la communication patient-soignant. Il s'agit d'intégrer non seulement les compétences de la population en matière de santé mais aussi les compétences communicationnelles d'un système de santé qui se complexifie. Health literacy is defined as "the degree to which individuals have the capacity to obtain, process, and understand basic health information and services needed to make appropriate health decisions." Low health literacy mainly affects certain populations at risk limiting access to care, interaction with caregivers and self-management. If there are screening tests, their routine use is not advisable and recommended interventions in practice consist rather to reduce barriers to patient-caregiver communication. It is thus important to include not only population's health literacy but also communication skills of a health system wich tend to become more complex.
Resumo:
Several SL(3,C) self-dual instanton solutions of the Yang-Mills equations are presented which have very striking properties. While one of them is regular and SU(3) inside (outside) a sphere of arbitrarily large (small) radius, another one has all the characteristics of a meron solution (in particular its topological charge is concentrated at one point) although its Pontryagin number equals one. Their continuation to Minkowski space is also studied.
Resumo:
Prognosis after severe traumatic brain injury (TBI) is determined by the severity of initial injury and secondary cerebral damage. The main determinants of secondary cerebral damage are brain ischemia and oedema. Traumatic brain injury is a heterogeneous disease. Head CT-scan is essential in evaluating initial type of injury and severity of brain oedema. A standardised approach based on prevention and treatment of secondary cerebral damage is the only effective therapeutic strategy of severe TBI. We review the classification, pathophysiology and treatment of secondary cerebral damage after severe TBI and discuss the management of intracranial hypertension, cerebral perfusion pressure and brain ischemia.
Resumo:
The Gross-Neveu model in an S^1 space is analyzed by means of a variational technique: the Gaussian effective potential. By making the proper connection with previous exact results at finite temperature, we show that this technique is able to describe the phase transition occurring in this model. We also make some remarks about the appropriate treatment of Grassmann variables in variational approaches.
Resumo:
Abstract Empirical testing of candidate vaccines has led to the successful development of a number of lifesaving vaccines. The advent of new tools to manipulate antigens and new methods and vectors for vaccine delivery has led to a veritable explosion of potential vaccine designs. As a result, selection of candidate vaccines suitable for large-scale efficacy testing has become more challenging. This is especially true for diseases such as dengue, HIV, and tuberculosis where there is no validated animal model or correlate of immune protection. Establishing guidelines for the selection of vaccine candidates for advanced testing has become a necessity. A number of factors could be considered in making these decisions, including, for example, safety in animal and human studies, immune profile, protection in animal studies, production processes with product quality and stability, availability of resources, and estimated cost of goods. The "immune space template" proposed here provides a standardized approach by which the quality, level, and durability of immune responses elicited in early human trials by a candidate vaccine can be described. The immune response profile will demonstrate if and how the candidate is unique relative to other candidates, especially those that have preceded it into efficacy testing and, thus, what new information concerning potential immune correlates could be learned from an efficacy trial. A thorough characterization of immune responses should also provide insight into a developer's rationale for the vaccine's proposed mechanism of action. HIV vaccine researchers plan to include this general approach in up-selecting candidates for the next large efficacy trial. This "immune space" approach may also be applicable to other vaccine development endeavors where correlates of vaccine-induced immune protection remain unknown.