Treatment of the afebrile patient after catheter withdrawal: drugs and duration

AbstractCatheter-related infections constitute 10–15% of all nosocomial infections, and constitute a relevant and growing problem, with an impact that is far from irrelevant, especially in the intensive care unit. The most frequent pathogens implicated come from the skin flora; Gram-positive cocci are responsible for about two-thirds of the infections, and Candida has emerged as another important cause. Questions about drug, route of administration, dosage and duration of antibiotherapy for patients who have become apyretic and with no signs of sepsis after catheter removal are still under debate, and far from being definitively answered. Decisions regarding these questions are based on three main factors: namely, which is the microoorganism responsible for the infection, what was the time to response, and what kind of patient are we dealing with? However, the microorganism is clearly the main factor in making a decision. In summary, all catheter-related infections should be treated with appropriate antibiotics, regardless of the removal of the catheter, with parenteral drugs, using high doses and short courses, namely 1 week, and de-escalating to narrow-spectrum drugs on the basis of susceptibility tests as soon as possible. Staphylococcus aureus catheter-related infections constitute an exception, needing longer courses, as it is difficult to predict who will be high-risk patients

The effect of phase transitions on the droplet size distribution in homogeneous isotropic turbulence

We investigate the dynamics of an ensemble of discrete aerosol droplets in a homogeneous, isotropic turbulent flow. Our focus is on the stationary distribution of droplet sizes that develops as a result of evaporation and condensation effects. For this purpose we simulate turbulence in a domain with periodic boundary conditions using pseudo-spectral discretization. We solve in addition equations for the temperature and for a scalar field, which represents the background humidity against which the size of the droplets evolves. We apply large-scale forcing of the velocity field to reach a statistically steady state. The droplets are transported by the turbulent field while exchanging heat and mass with the evolving temperature and humidity fields. In this Euler-Lagrange framework, we assume the droplets volume fraction to be sufficiently low to allow one-way coupling of the droplets and turbulence dynamics. The motion of the droplets is time-accurately tracked. The Stokes drag force is included in the equation of motion of the individual droplets. The responsiveness of the droplets to small turbulent scales is directly related to the size of the individual spherical droplets. We perform direct numerical simulation to ultimately obtain the probability density function of the evolving radius of the droplets at different points in time with characteristic heat and mass transfer parameters. We determine the gradual convergence of the distribution function to its statistically stationary state for forced homogeneous, isotropic turbulence

Um Sistema de Informação Geográfica para a prevenção e combate aos incêndios florestais (SIGPF)

Comunicação apresentada no Congresso Ibérico de Fogos Florestais que decorreu de 17 a 19 de Dezembro de 2000, em Castelo Branco, na Escola Superior Agrária do Instituto Politécnico.Para uma maior eficácia na prevenção e combate aos fogos florestais é fundamental um conhecimento adequado e actualizado da área de intervenção. No âmbito da protecção civil, compete às Câmaras Municipais, em conjugação com outras instituições, a elaboração de Planos Municipais de Intervenção Florestal, no sentido de minimizar o risco da ocorrência de incêndios e optimizar os meios envolvidos no combate. Os sistemas de informação geográfica ao relacionarem informação espacial e alfanumérica, possibilitando a manipulação, análise e visualização dos dados, apresentam-se como um recurso informático de extrema importância no planeamento de medidas de prevenção e combate aos fogos florestais. A metodologia utilizada passou por uma sequência de fases usuais na construção deste tipo de aplicações, tendo como objectivo a caracterização da área de estudo quanto à ocupação do solo, rede viária, superfícies com água e postos de vigia. Os resultados obtidos são (1) cartografia temática de ocupação de solo e infra-estrutura (2) carta de risco de incêndio florestal

Approximation of periodic solutions for a dissipative hyperbolic equation

This paper studies the numerical approximation of periodic solutions for an exponentially stable linear hyperbolic equation in the presence of a periodic external force f. These approximations are obtained by combining a fixed point algorithm with the Galerkin method. It is known that the energy of the usual discrete models does not decay uniformly with respect to the mesh size. Our aim is to analyze this phenomenon's consequences on the convergence of the approximation method and its error estimates. We prove that, under appropriate regularity assumptions on f, the approximation method is always convergent. However, our error estimates show that the convergence's properties are improved if a numerically vanishing viscosity is added to the system. The same is true if the nonhomogeneous term f is monochromatic. To illustrate our theoretical results we present several numerical simulations with finite element approximations of the wave equation in one or two dimensional domains and with different forcing terms

Reusing built heritage resources with sustainability

Many old cities spread all over the world, face obsolete buildings, quarters or areas that urge for maintenance, re-adaptation or demolition. Among time, built heritage has always been re-used or recycled, suffering adaptations related to the living needs of its inhabitants and contemporary society context. Commonly, building’s lifespan regarding its survival and eventual disappearance, either partial or total, has scarcely been taken into consideration. But now, with the Ecological concerns as an imperative XXI century claim from our devastated planet, Society has to face existent buildings as a liable construction resource, that already occupies a considerable area of our cities and that would be foolish to waste. Re-Architecture: Lifespan Rehabilitation of Built Heritage, born in 2002 as a concept and is now being developed in a PhD research; coordinated by Prof. Ir. Jouke Post and Dr. Ir. Peter Erkelens. This renewal system under development, will not only contribute for the quality improvement of existent buildings interventions; in flexibility, sustainability and lifespan assessment, adaptive to consumer/user expectations and needs; but also for the preservation of both built and environmental heritage

Asymptotic models and inference for extremes of spatio-temporal data

Recently there has been a lot of effort to model extremes of spatially dependent data. These efforts seem to be divided into two distinct groups: the study of max-stable processes, together with the development of statistical models within this framework; the use of more pragmatic, flexible models using Bayesian hierarchical models (BHM) and simulation based inference techniques. Each modeling strategy has its strong and weak points. While max-stable models capture the local behavior of spatial extremes correctly, hierarchical models based on the conditional independence assumption, lack the asymptotic arguments the max-stable models enjoy. On the other hand, they are very flexible in allowing the introduction of physical plausibility into the model. When the objective of the data analysis is to estimate return levels or kriging of extreme values in space, capturing the correct dependence structure between the extremes is crucial and max-stable processes are better suited for these purposes. However when the primary interest is to explain the sources of variation in extreme events Bayesian hierarchical modeling is a very flexible tool due to the ease with which random effects are incorporated in the model. In this paper we model a data set on Portuguese wildfires to show the flexibility of BHM in incorporating spatial dependencies acting at different resolutions