DomeView : a tool for digital planetariums

The content produced for fulldome projection is usually made in a frame (the master) with a format corresponding to a projection of the dome on a plane, commonly the fisheye projection. Due to the distortions involved, looking at the master does not give a clear idea of the final result once projectedon a planetarium dome. The common solution when creating and composing content is to go through an iterative process, making successive projections on a planetarium until the desired result is achieved. However, repeatedaccess to a planetarium is difficult, costly, and time consuming. So there is a need for an application that can provide theuser with a clear notion of the final result in the planetarium. In addition, if the application could be used to show content in a small (single projector) planetarium, like a portable one, its versatility would increase substantially. This paper reports on such an application: Domeview

Zonal flows and long-distance correlations during the formation of the edge shear layer in the TJ-II stellarator

A theoretical interpretation is given for the observed long-distance correlations in potential fluctuations in TJ-II. The value of the correlation increases above the critical point of the transition for the emergence of the plasma edge shear flow layer. Mean (i.e. surface averaged, zero-frequency) sheared flows cannot account for the experimental results. A model consisting of four envelope equations for the fluctuation level, the mean flow shear, the zonal flow amplitude shear, and the averaged pressure gradient is proposed. It is shown that the presence of zonal flows is essential to reproduce the main features of the experimental observations.Comment: 19 pages, 7 figure

Neurologic Paraneoplastic Syndromes

Algumas síndromes neurológicas estão ocasionalmente associadas ao cancro sistémico, na forma de síndrome paraneoplásica. Destas, a degenerescência cerebelosa subaguda, neuronopatia sensitiva, dermatomiosite polimiosite, síndrome miasténica de Eaton-Lambert e neuronopatia motora subaguda tornam obrigatória uma investigação exaustiva, no sentido de identificar o tumor primitivo, devido à sua forte correlação com neoplasia oculta.Os AA apresentam uma revisão sumária destas síndromes, ilustrando as três primeiras com casos clínicos. Faz-se referência aos aspectos imunológicos associados e à sua importância na caracterização destas entidades

Oral Contraceptive Use and Clinical Outcomes in Patients with Multiple Sclerosis

Experimental and clinical data suggest a role of sex steroids in the pathogenesis of multiple sclerosis (MS). Scant information is available about the potential effect of oral contraceptive (OC) use on the prognosis of the disease. We aimed to evaluate this. The study population consisted of 132 women with relapsing-remitting MS before receiving disease modifying treatment and a mean disease duration 6.2 (SD 5.1) years. Three groups of patients were distinguished according to their OC behavior: [1] never-users, patients who never used OC [2] past-users, patients who stopped OC use before disease onset, and [3] after-users, those who used these drugs after disease onset. Multiple linear and logistic regression models were used to analyze the association between oral contraceptive use and annualized relapse rates, disability accumulation and severity of the disease. After-user patients had lower Expanded Disability Status Scale (EDSS) and Multiple Sclerosis Severity Score (MSSS) values than never users (p<0.001 and p=0.002, respectively) and past users (p=0.010 and p=0.002, respectively). These patients were also more likely to have a benign disease course (MSSS<2.5) than never and past users together (OR: 4.52, 95%CI: 2.13-9.56, p<0.001). This effect remained significant after adjustment for confounders, including smoking and childbirths (OR: 2.97, 95%CI: 1.24, 6.54, p=0.011 and for MSSS β: -1.04; 95% C.I. -1.78, -0.30, p=0.006). These results suggest that OC use in women with relapsing-remitting MS is possible associated with a milder disabling disease course

The CWKB particle production and classical condensate in de Sitter spacetime

The complex time WKB approximation is an effective tool in studying particle production in curved spacetime. We use it in this work to understand the formation of classical condensate in expanding de Sitter spacetime. The CWKB leads to the emergence of thermal spectrum that depends crucially on horizons (as in de Sitter spacetime) or observer dependent horizons (as in Rindler spacetime). A connection is sought between the horizon and the formation of classical condensate. We concentrate on de Sitter spacetime and study the cosmological perturbation of $k=0$ mode with various values of $m/H_0$. We find that for a minimally coupled free scalar field for $m^2/H_0^2<2$, the one-mode occupation number grows more than unity soon after the physical wavelength of the mode crosses the Hubble radius and soon after diverges as $N(t)\sim O(1)[\lambda_{phys}(t)/{H_0^{-1}}]^{2\sqrt{\nu^2-1/4}}$, where $\nu\equiv (9/4 -m^2/{H_0^2})^{1/2}$. The results substantiates the previous works in this direction. We also find the correct oscillation and behaviour of $N(z)$ at small $z$ from a single expression using CWKB approximation for various values of $m/H_0$. We also discuss decoherence in relation to the formation of classical condensate. We also find that the squeezed state formalism and CWKB method give identical results.Comment: 19 pages, revtex, 5 figure