Imagerie à travers la turbulence par déconvolution myope multi-trame

La déconvolution par analyse de fronts d'onde est une technique d'imagerie à haute résolution en présence de turbulence atmosphérique. Elle consiste en une déconvolution multi-trame d'images courte pose utilisant des mesures de fronts d'onde enregistrées simultanément. L'approche bayésienne proposée ici nous permet de construire un algorithme de déconvolution original pour prendre en compte le bruit sur les mesures de front d'onde. L'utilisation de connaissances a priori sur les objets observés et sur la statistique de la turbulence atmosphérique nous permet de plus de régulariser le problème. Une simulation numérique montre l'utilité de la régularisation sur les fronts d'onde

Combining Logic and Probabilities for Discovering Mappings between Taxonomies

Abstract. In this paper, we investigate a principled approach for defining and discovering probabilistic mappings between two taxonomies. First, we compare two ways of modeling probabilistic mappings which are compatible with the logical constraints declared in each taxonomy. Then we describe a generate and test algorithm which minimizes the number of calls to the probability estimator for determining those mappings whose probability exceeds a certain threshold. Finally, we provide an experimental analysis of this approach

Essais en bassin du comportement dynamique d'une éolienne flottante sous l'action conjuguée de la houle et du vent

Ce travail porte sur l'étude expérimentale du comportement dynamique d'une éolienne offshore flottante sous l'action conjuguée de la houle et du vent. Pour cela, un nouveau moyen d'essai permettant la génération de vent a été développé sur le bassin de génie océanique de l'École Centrale de Nantes. La qualification aérodynamique de ce dispositif a mis en évidence un faible taux de turbulence et une bonne homogénéité spatiale. Dans un second temps, un modèle réduit d'éolienne flottante a été dimensionné à l'échelle du 1/50e suivant une méthodologie adaptée à ce type d'essai. Le dimensionnement de la maquette est basé sur l'éolienne générique NREL 5MW. Cette éolienne repose sur un flotteur de type semi-submersible (Dutch Tri-floater). Cette maquette a ensuite été étudiée en bassin afin de caractériser son comportement sous l'action de la houle et du vent. L'influence de la directionnalité de la houle et de fluctuations basses fréquences caractéristiques d'un spectre de vent marin est aussi évoquée dans ce document

The EAGLE instrument for the E-ELT: developments since delivery of Phase A

The EAGLE instrument is a Multi-Object Adaptive Optics (MOAO) fed, multiple Integral Field Spectrograph (IFS), working in the Near Infra-Red (NIR), on the European Extremely Large Telescope (E-ELT). A Phase A design study was delivered to the European Southern Observatory (ESO) leading to a successful review in October 2009. Since that time there have been a number of developments, which we summarize here. Some of these developments are also described in more detail in other submissions at this meeting. The science case for the instrument, while broad, highlighted in particular: understanding the stellar populations of galaxies in the nearby universe, the observation of the evolution of galaxies during the period of rapid stellar build-up between redshifts of 2-5, and the search for 'first light' in the universe at redshifts beyond 7. In the last 2 years substantial progress has been made in these areas, and we have updated our science case to show that EAGLE is still an essential facility for the E-ELT. This in turn allowed us to revisit the science requirements for the instrument, confirming most of the original decisions, but with one modification. The original location considered for the instrument (a gravity invariant focal station) is no longer in the E-ELT Construction Proposal, and so we have performed some preliminary analyses to show that the instrument can be simply adapted to work at the E-ELT Nasmyth platform. Since the delivery of the Phase A documentation, MOAO has been demonstrated on-sky by the CANARY experiment at the William Herschel Telescope.Comment: 10 pages, SPIE Conference proceedings, Amsterdam, July 201

Hyperbolic manifolds with convex boundary

Let $(M, \partial M)$ be a compact 3-manifold with boundary, which admits a convex co-compact hyperbolic metric. We consider the hyperbolic metrics on $M$ such that the boundary is smooth and strictly convex. We show that the induced metrics on the boundary are exactly the metrics with curvature $K>-1$, and that the third fundamental forms of \dr M are exactly the metrics with curvature $K2\pi$. Each is obtained exactly once. Other related results describe existence and uniqueness properties for other boundary conditions, when the metric which is achieved on \dr M is a linear combination of the first, second and third fundamental forms.Comment: Check the updated version(s) on http://picard.ups-tlse.fr/~schlenker/ Version 2: an error corrected. Version 3: simpler main statement, small corrections, more details on one technical statement. Version 5: one error correcte

Henipavirus and Tioman Virus Antibodies in Pteropodid Bats, Madagascar

Specimens were obtained from the 3 Malagasy fruit bats, Pteropus rufus, Eidolon dupreanum, and Rousettus madagascariensis. Antibodies against Nipah, Hendra, and Tioman viruses were detected by immunoassay in 23 and by serum neutralization tests in 3 of 427 serum samples, which suggests that related viruses have circulated in Madagascar

Accumulation and transport of microbial-size particles in a pressure protected model burn unit: CFD simulations and experimental evidence

<p>Abstract</p> <p>Background</p> <p>Controlling airborne contamination is of major importance in burn units because of the high susceptibility of burned patients to infections and the unique environmental conditions that can accentuate the infection risk. In particular the required elevated temperatures in the patient room can create thermal convection flows which can transport airborne contaminates throughout the unit. In order to estimate this risk and optimize the design of an intensive care room intended to host severely burned patients, we have relied on a computational fluid dynamic methodology (CFD).</p> <p>Methods</p> <p>The study was carried out in 4 steps: i) patient room design, ii) CFD simulations of patient room design to model air flows throughout the patient room, adjacent anterooms and the corridor, iii) construction of a prototype room and subsequent experimental studies to characterize its performance iv) qualitative comparison of the tendencies between CFD prediction and experimental results. The Electricité De France (EDF) open-source software <it>Code_Saturne</it>^®(<url>http://www.code-saturne.org</url>) was used and CFD simulations were conducted with an hexahedral mesh containing about 300 000 computational cells. The computational domain included the treatment room and two anterooms including equipment, staff and patient. Experiments with inert aerosol particles followed by time-resolved particle counting were conducted in the prototype room for comparison with the CFD observations.</p> <p>Results</p> <p>We found that thermal convection can create contaminated zones near the ceiling of the room, which can subsequently lead to contaminate transfer in adjacent rooms. Experimental confirmation of these phenomena agreed well with CFD predictions and showed that particles greater than one micron (i.e. bacterial or fungal spore sizes) can be influenced by these thermally induced flows. When the temperature difference between rooms was 7°C, a significant contamination transfer was observed to enter into the positive pressure room when the access door was opened, while 2°C had little effect. Based on these findings the constructed burn unit was outfitted with supplemental air exhaust ducts over the doors to compensate for the thermal convective flows.</p> <p>Conclusions</p> <p>CFD simulations proved to be a particularly useful tool for the design and optimization of a burn unit treatment room. Our results, which have been confirmed qualitatively by experimental investigation, stressed that airborne transfer of microbial size particles via thermal convection flows are able to bypass the protective overpressure in the patient room, which can represent a potential risk of cross contamination between rooms in protected environments.</p

Chikungunya Virus, Cameroon, 2006

We report the isolation of chikungunya virus from a patient during an outbreak of a denguelike syndrome in Cameroon in 2006. The virus was phylogenetically grouped in the Democratic Republic of the Congo cluster, indicating a continuous circulation of a genetically similar chikungunya virus population during 6 years in Central Africa