851 resultados para Approaching methodology
Resumo:
OBJECTIVE: The aim of this study was to establish and validate a three-dimensional imaging protocol for the assessment of Computed Tomography (CT) scans of abdominal aortic aneurysms in UK EVAR trials patients. Quality control and repeatability of anatomical measurements is important for the validity of any core laboratory. METHODS: Three different observers performed anatomical measurements on 50 preoperative CT scans of aortic aneurysms using the Vitrea 2 three-dimensional post-imaging software in a core laboratory setting. We assessed the accuracy of intra and inter observer repeatability of measurements, the time required for collection of measurements, 3 different levels of automation and 3 different automated criteria for measurement of neck length. RESULTS: None of the automated neck length measurements demonstrated sufficient accuracy and it was necessary to perform checking of the important automated landmarks. Good intra and limited inter observer agreement were achieved with three-dimensional assessment. Complete assessment of the aneurysm and iliacs took an average (SD) of 17.2 (4.1) minutes. CONCLUSIONS: Aortic aneurysm anatomy can be assessed reliably and quickly using three-dimensional assessment but for scans of limited quality, manual checking of important landmarks remains necessary. Using a set protocol, agreement between observers is satisfactory but not as good as within observers.
Resumo:
Statins have anti-inflammatory and immunomodulatory properties in addition to their lipid-lowering effects. Currently, the effects of statins on multiple sclerosis are still controversial. Therefore, randomized clinical trials are needed to provide better evidence on the therapeutic potential of statins in multiple sclerosis. The SWiss Atorvastatin and Interferon Beta-1b trial in Multiple Sclerosis (SWABIMS) evaluates the efficacy, safety and tolerability of atorvastatin 40 mg per os daily and subcutaneous interferon beta-1b every other day compared to monotherapy with subcutaneous interferon beta-1b every other day in patients with relapsing-remitting multiple sclerosis.
Resumo:
Monte Carlo simulation was used to evaluate properties of a simple Bayesian MCMC analysis of the random effects model for single group Cormack-Jolly-Seber capture-recapture data. The MCMC method is applied to the model via a logit link, so parameters p, S are on a logit scale, where logit(S) is assumed to have, and is generated from, a normal distribution with mean μ and variance σ2 . Marginal prior distributions on logit(p) and μ were independent normal with mean zero and standard deviation 1.75 for logit(p) and 100 for μ ; hence minimally informative. Marginal prior distribution on σ2 was placed on τ2=1/σ2 as a gamma distribution with α=β=0.001 . The study design has 432 points spread over 5 factors: occasions (t) , new releases per occasion (u), p, μ , and σ . At each design point 100 independent trials were completed (hence 43,200 trials in total), each with sample size n=10,000 from the parameter posterior distribution. At 128 of these design points comparisons are made to previously reported results from a method of moments procedure. We looked at properties of point and interval inference on μ , and σ based on the posterior mean, median, and mode and equal-tailed 95% credibility interval. Bayesian inference did very well for the parameter μ , but under the conditions used here, MCMC inference performance for σ was mixed: poor for sparse data (i.e., only 7 occasions) or σ=0 , but good when there were sufficient data and not small σ .
Resumo:
Recent publishing on the migration phenomena in the communitarian and globalized Europe, puts in evidence a fundamental racism which is capable of making cultural processes grow and feed both chaos and social disorder. As a matter of fact we are approaching the ending debates on multicultural citizenship as well as on solidary integration and antiracism. Since the appearing of these phenomena, namely the huge post colonial migration in the nineteen-eighties, by which the colonized countries became almost “emigrant nurseries”, one could expect their stabilization. On the contrary, globalization and migration (twin subjects) everywhere still produce, at various levels, social disturbances together with some chauvinistic limitations as an ultimate kind of western prosperity defense. The peculiar European features of this new racism, less than ideological (superiority, homogeneity and civilizing mission), are confined to the concepts of patriotism, inequality and exclusion. In these terms one can understand why the new economic expansionism and the quest for new world markets makes European policies unstable, which remain undecided between conservatism, liberalism and extreme right. All this explains at least two things: the existing ambiguities of some European policies aiming to enhance particular forms of protectionism, and the difficulties in which the antiracist thought seems to be embedded. Indeed, according to what Walter Lorenz has already made clear, by using a well founded methodology, which prevents any fruitless protestations, it is impossible to contrast racism and nationalism. In such context, the educational field should try to use an operative epistemology. In other words the antiracist thought should dispose of competences and skills and, especially, personal and reflective capabilities. All this in order to avoid that which, in different historical scenes, permit the revival of the sense of moral opprobrium could not be identified with the political alibi to maintain privileges as well as advantages for the exclusive benefit of wealthy countries.