992 resultados para Space-charge fields
Resumo:
Pulmonary hypertension is a frequent complication of left heart disease arising from a wide range of cardiac disorders and is associated with poor prognosis. Its pathophysiology is complex with both passive mechanisms of elevated filling pressures in left cavities and occasionally reactive mechanisms of arterial vasoconstriction and remodelling to interplay. This stage, called <out-of-proportions> pulmonary hypertension, further worsens the heart failure patients' prognosis but is still a matter of debate concerning the criteria to apply for its diagnosis and concerning the best way to manage it. This article gives an overview of the importance and pathophysiology of pulmonary hypertension associated with left heart disease, and discusses the challenges associated with its diagnosis and treatment.
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This paper introduces a State Space approach to explain the dynamics of rent growth, expected returns and Price-Rent ratio in housing markets. According to the present value model, movements in price to rent ratio should be matched by movements in expected returns and expected rent growth. The state space framework assume that both variables follow an autoregressive process of order one. The model is applied to the US and UK housing market, which yields series of the latent variables given the behaviour of the Price-Rent ratio. Resampling techniques and bootstrapped likelihood ratios show that expected returns tend to be highly persistent compared to rent growth. The Öltered expected returns is considered in a simple predictability of excess returns model with high statistical predictability evidenced for the UK. Overall, it is found that the present value model tends to have strong statistical predictability in the UK housing markets.
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This paper introduces a State Space approach to explain the dynamics of rent growth, expected returns and Price-Rent ratio in housing markets. According to the present value model, movements in price to rent ratio should be matched by movements in expected returns and expected rent growth. The state space framework assume that both variables follow an autoregression process of order one. The model is applied to the US and UK housing market, which yields series of the latent variables given the behaviour of the Price-Rent ratio. Resampling techniques and bootstrapped likelihood ratios show that expected returns tend to be highly persistent compared to rent growth. The filtered expected returns is considered in a simple predictability of excess returns model with high statistical predictability evidence for the UK. Overall, it is found that the present value model tends to have strong statistical predictability in the UK housing markets.
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[Table des matières] Généralités sur la violence domestique: Définition de la violence domestique, Prise en charge: possibilités et limites, Dépistage de la violence domestique, Signes et symptômes évoquant un contexte de violence domestique &. La situation spécifique des femmes migrantes. - Documentation: Marche à suivre: check-list, Consentement, Constat médical en cas de violence domestique, Examen physique, Attestation. - Annexes: Bases légales, Gynécologie des enfants et adolescentes, Caisse maladie et éléments financiers, Coordonnées des centres spécialisés, Centres cantonaux d'aide aux victimes d'infraction (Centres LAVI), Littérature et liens. - Suppléments: Marche à suivre: check-list, Spécimens de constat médical [Editorial (extrait)] Le groupe de travail «Abus sexuels au cabinet médical» - constitué voici quelques années par la Société Suisse de Gynécologie et d'Obstétrique - s'est vu chargé par le président de la société d'élaborer un guide pratique pour aborder la violence domestique. En Suisse, des études d'envergure montrent qu'une femme sur quatre au cours de sa vie et une femme sur dix durant les !" derniers mois sont confrontées à la violence. Ces études révèlent un lien étroit entre de nombreux problèmes de santé et le fait de subir de la violence conjugale. La moitié des femmes touchées présentent des problèmes de santé physiques et deux tiers des problèmes de santé psychiques ou des troubles d'ordre psychosomatiques. Et ce sont ces problèmes qui amèneront les femmes à consulter leur médecin. Le groupe de travail poursuit l'objectif d'améliorer la prise en charge des femmes concernées par la violence. En effet, aussi longtemps que la cause réelle des symptômes et des plaintes, à savoir le fait de vivre dans un contexte de violence, n'est pas dépistée, aucune mesure thérapeutique ne pourra avoir d'impact durable sur la santé de la patiente. Les femmes concernées par la violence domestique s'adressent de préférence à leur médecin. De ce fait, les gynécologues, au sein de leur cabinet et dans les cliniques, vont entrer en contact avec ces femmes. Il est donc important que chacun dispose des connaissances nécessaires à leur prise en charge.
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Les maladies chroniques représentent un fardeau important pour la société, en termes de morbidité, dépendance, qualité de vie, mortalité et coûts de la santé. La prise en charge des maladies chroniques constitue ainsi une priorité des systèmes de santé. Tandis que des programmes de prévention et prise en charge des maladies chroniques («prevention and chronic disease management») ont été mis sur pieds depuis plus d'une décennie d'abord en Amérique du Nord puis en Europe, leur développement en Suisse est récent. Ces programmes sont explicitement structurés et organisés, centrés sur les patients et comportent constamment un élément d'éducation thérapeutique. De plus, ils impliquent un travail en équipe ainsi que des prises en charge stratifiées en fonction de la sévérité de la maladie et des besoins des patients, et basées sur les preuves de leur efficacité. Il est important que les médecins et autres professionnels de la santé, ainsi que tous les autres acteurs du système sanitaire reconnaissent la nécessité de mettre en place des modalités adéquates et efficaces de prise en charge des patients présentant des maladies chroniques, participent à leur développement et les soutiennent.
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The human auditory system is comprised of specialized but interacting anatomic and functional pathways encoding object, spatial, and temporal information. We review how learning-induced plasticity manifests along these pathways and to what extent there are common mechanisms subserving such plasticity. A first series of experiments establishes a temporal hierarchy along which sounds of objects are discriminated along basic to fine-grained categorical boundaries and learned representations. A widespread network of temporal and (pre)frontal brain regions contributes to object discrimination via recursive processing. Learning-induced plasticity typically manifested as repetition suppression within a common set of brain regions. A second series considered how the temporal sequence of sound sources is represented. We show that lateralized responsiveness during the initial encoding phase of pairs of auditory spatial stimuli is critical for their accurate ordered perception. Finally, we consider how spatial representations are formed and modified through training-induced learning. A population-based model of spatial processing is supported wherein temporal and parietal structures interact in the encoding of relative and absolute spatial information over the initial ∼300ms post-stimulus onset. Collectively, these data provide insights into the functional organization of human audition and open directions for new developments in targeted diagnostic and neurorehabilitation strategies.
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This paper aims at providing a Bayesian parametric framework to tackle the accessibility problem across space in urban theory. Adopting continuous variables in a probabilistic setting we are able to associate with the distribution density to the Kendall's tau index and replicate the general issues related to the role of proximity in a more general context. In addition, by referring to the Beta and Gamma distribution, we are able to introduce a differentiation feature in each spatial unit without incurring in any a-priori definition of territorial units. We are also providing an empirical application of our theoretical setting to study the density distribution of the population across Massachusetts.
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Tobacco smoking is a major public health issue and a better understanding of tobacco addiction represents an important challenge. Many factors are involved in tobacco addiction, including genetic factors. Taking them into account in smoking cessation programs would allow to better adapt these programs to individual characteristics and improve their rate of success. Given enzymatic induction by tobacco smoke, smoking cessation can nevertheless have important consequences on the metabolism of some drugs, that have to be taken into consideration. Here we present different clinical and genetic aspects of smoking and of smoking cessation. A dose adjustment of drugs influenced by tobacco smoke is proposed when quitting smoking.
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Water movement in unsaturated soils gives rise to measurable electrical potential differences that are related to the flow direction and volumetric fluxes, as well as to the soil properties themselves. Laboratory and field data suggest that these so-called streaming potentials may be several orders of magnitudes larger than theoretical predictions that only consider the influence of the relative permeability and electrical conductivity on the self potential (SP) data. Recent work has improved predictions somewhat by considering how the volumetric excess charge in the pore space scales with the inverse of water saturation. We present a new theoretical approach that uses the flux-averaged excess charge, not the volumetric excess charge, to predict streaming potentials. We present relationships for how this effective excess charge varies with water saturation for typical soil properties using either the water retention or the relative permeability function. We find large differences between soil types and the predictions based on the relative permeability function display the best agreement with field data. The new relationships better explain laboratory data than previous work and allow us to predict the recorded magnitudes of the streaming potentials following a rainfall event in sandy loam, whereas previous models predict values that are three orders of magnitude too small. We suggest that the strong signals in unsaturated media can be used to gain information about fluxes (including very small ones related to film flow), but also to constrain the relative permeability function, the water retention curve, and the relative electrical conductivity function.
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"Vegeu el resum a l'inici del document del fitxer adjunt"
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Water transport in wood is vital for the survival of trees. With synchrotron radiation X-ray tomographic microscopy (SRXTM), it has become possible to characterize and quantify the three-dimensional (3D) network formed by vessels that are responsible for longitudinal transport. In the present study, the spatial size dependence of vessels and the organization inside single growth rings in terms of vessel-induced porosity was studied by SRXTM. Network characteristics, such as connectivity, were deduced by digital image analysis from the processed tomographic data and related to known complex network topologies.
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Real-world objects are often endowed with features that violate Gestalt principles. In our experiment, we examined the neural correlates of binding under conflict conditions in terms of the binding-by-synchronization hypothesis. We presented an ambiguous stimulus ("diamond illusion") to 12 observers. The display consisted of four oblique gratings drifting within circular apertures. Its interpretation fluctuates between bound ("diamond") and unbound (component gratings) percepts. To model a situation in which Gestalt-driven analysis contradicts the perceptually explicit bound interpretation, we modified the original diamond (OD) stimulus by speeding up one grating. Using OD and modified diamond (MD) stimuli, we managed to dissociate the neural correlates of Gestalt-related (OD vs. MD) and perception-related (bound vs. unbound) factors. Their interaction was expected to reveal the neural networks synchronized specifically in the conflict situation. The synchronization topography of EEG was analyzed with the multivariate S-estimator technique. We found that good Gestalt (OD vs. MD) was associated with a higher posterior synchronization in the beta-gamma band. The effect of perception manifested itself as reciprocal modulations over the posterior and anterior regions (theta/beta-gamma bands). Specifically, higher posterior and lower anterior synchronization supported the bound percept, and the opposite was true for the unbound percept. The interaction showed that binding under challenging perceptual conditions is sustained by enhanced parietal synchronization. We argue that this distributed pattern of synchronization relates to the processes of multistage integration ranging from early grouping operations in the visual areas to maintaining representations in the frontal networks of sensory memory.