The explosion mechanism of core-collapse supernovae: progress in supernova theory and experiments

The explosion of core-collapse supernova depends on a sequence of events taking place in less than a second in a region of a few hundred kilometers at the center of a supergiant star, after the stellar core approaches the Chandrasekhar mass and collapses into a proto-neutron star, and before a shock wave is launched across the stellar envelope. Theoretical efforts to understand stellar death focus on the mechanism which transforms the collapse into an explosion. Progress in understanding this mechanism is reviewed with particular attention to its asymmetric character. We highlight a series of successful studies connecting observations of supernova remnants and pulsars properties to the theory of core-collapse using numerical simulations. The encouraging results from first principles models in axisymmetric simulations is tempered by new puzzles in 3D. The diversity of explosion paths and the dependence on the pre-collapse stellar structure is stressed, as well as the need to gain a better understanding of hydrodynamical and MHD instabilities such as SASI and neutrino-driven convection. The shallow water analogy of shock dynamics is presented as a comparative system where buoyancy effects are absent. This dynamical system can be studied numerically and also experimentally with a water fountain. The potential of this complementary research tool for supernova theory is analyzed. We also review its potential for public outreach in science museums.Comment: 19 pages, 6 figures, invited review accepted for publication in PAS

Un cadre de conception pour réunir les modèles d'interaction et l'ingénierie des interfaces

National audienceWe present HIC (Human-system Interaction Container), a general framework for the integration of advanced interaction in the software development process. We show how this framework allows to reconcile the software development methods (such MDA, MDE) with the architectural models of software design such as MVC or PAC. We illustrate our approach thanks to two different types of implementation for this concept in two different business areas: one software design pattern, MVIC (Model View Interaction Control) and one architectural model, IM (Interaction Middleware)

Un service d'urgence en psychiatrie : quelle interface pour l'accès aux soins ?: Etude statistique de l'activité d'un service d'urgence de 1999 à 2003

Article en ligne : http://www.john-libbey-eurotext.fr/en/revues/medecine/ipe/e-docs/00/04/21/59/article.phtmlInternational audienceEmergency psychiatric services: what interface is needed to access care? Statistical study into the activities of an emergency ward from 1999 to 2003.Emergency reception is a core issue in the question of access to psychiatric care. Reception facilities are not restricted to an institution, but are rather an interface between the various types of demand and the array of possible courses of treatment in psychiatry. At the specialised hospital at Saint-Jean-de-Dieu in Lyon, the emergency ward and department for medical information inventoried arrivals in their emergency reception over a period of 5 years (1999-2003) asking doctors to fill in a form giving precise details on the profile of patients dealt with. The data compiled represents 14,689 emergency situations corresponding to 6,568 patients. Different patient profiles were established revealing differing demands on emergency care. In emergency reception a crisis reception service and chronicity reception service coexist. Emergency reception is a crucial interface for patients of the first category (crisis profile) to access care, but a “substitute” structure for the second group (chronic). This raises the idea of creating reception areas specifically directed at chronic mental distress.L'accueil des urgences est au cœur de la problématique de l'accès aux soins en psychiatrie. Loin d'être exclusivement un lieu de soin institutionnel, il se présente comme une interface entre une demande multiforme de prise en charge et la multiplicité des parcours de soin en psychiatrie. Au CHS Saint-Jean-de-Dieu à Lyon, le service des urgences et le DIM ont recensé, pendant 5 ans (de 1999 à 2003), les passages dans l'UAU de leur établissement grâce à une fiche remplie par les médecins et renseignant de façon précise le profil des patients reçus en urgence. Les données collectées représentent 14 689 situations d'urgences correspondant à 6 568 patients. Différents profils de patients ont pu être établis et amènent à constater une consommation différenciée de l'urgence. À l'UAU cohabitent un accueil de la crise et un accueil de la chronicité. L'urgence est une interface indispensable pour l'accès aux soins pour les patients de la première catégorie (profil de crise) mais une structure de « substitution » pour la deuxième population (chroniques). Cela amène à penser la création de lieux d'accueil spécifiques de la détresse psychique chroniqu

A new geodynamic interpretation for the South Portuguese Zone (SW Iberia) and the Iberian Pyrite Belt genesis.

International audienceThe South Portuguese Zone (SPZ) constitutes the southernmost segment of the Variscan Iberian Massif. It is bounded to the north by the Beja-Acebuches Ophiolitic Complex and related accretionary wedge. To the south lie the Iberian Pyrite Belt (IPB) and flysch deposits forming the southern extent of the zone. Structural analysis within the Spanish side of the SPZ supports continuous south propagating deformation, evolving from early synmetamorphic thrusting in the internal zone to thin-skinned tectonics in the southern external domain. The accretion of the SPZ to the Ossa Morena Zone is also witnessed by the presence of various mélanges, observed throughout the investigated area. Part of the mélanges observed in the IPB are related to the volcanics and mineralizations setting. A key point to understand the IPB mineralizations genesis is to constrain the volcanogenic model. One underestimated feature is the large amount of submarine calc-alkaline ignimbritic facies, implying the presence of caldera structures within the province. Such correlation between caldera environment and ore deposits strongly suggests that the IPB developed in a continental arc. Our geodynamic model proposes an early north directed subduction associated with the obduction of the oceanic crust toward the south. Southward, this episode is immediately followed by the development of the accretionary prism, while farther south, a second subduction zone responsible for the arc setting of the IPB initiates. Subsequent Visean continental collision is associated with the deposit of the south propagating flysch and the present geometry of the SPZ

Compact and high-quality gamma-ray source applied to 10 μm-range resolution radiography

International audienceGamma-ray beams with optimal and tuneable size, temperature, and dose are of great interest for a large variety of applications. These photons can be produced by the conversion of energetic electrons through the bremsstrahlung process in a dense material. This work presents the experimental demonstration of 30 μm resolution radiography of dense objects using an optimized gamma-ray source, produced with a high-quality electron beam delivered by a compact laser-plasma accelerator

Proving the absence of unbounded polymers in rule-based models

International audienceRule-based languages, such as Kappa and BNGL, allow for the description of very combinatorial models of interactions between proteins. A huge (when not infinite) number of different kinds of bio-molecular compounds may arise due to proteins with multiple binding and phosphorylation sites. Knowing beforehand whether a model may involve an infinite number of different kinds of bio-molecular compounds is crucial for the modeller. On the first hand, having an infinite number of kinds of bio-molecular compounds is sometimes a hint for modelling flaws: forgetting to specify the conflicts among binding rules is a common mistake. On the second hand, it impacts the choice of the semantics for the models (among stochastic, differential, hybrid). In this paper, we introduce a data-structure to abstract the potential unbounded polymers that may be formed in a rule-based model. This data-structure is a graph, the nodes and the edges of which are labelled with patterns. By construction, every potentially unbounded polymer is associated to at least one cycle in that graph. This data-structure has two main advantages. Firstly, as opposed to site-graphs, one can reason about cycles without enumerating them (by the means of Tarjan's algorithm for detecting strongly connected components). Secondly, this data-structures may be combined easily with information coming from additional reachability analysis: the edges that are labelled with an overlap that is proved unreachable in the model may be safely discarded

Démarche participative "Centre et Rives" en Ville de Neuchâtel, résultats de la consultation sur l'avant-projet Ring

Dans le cadre d’une démarche de processus participatif lancée par la Ville de Neuchâtel par l’intermédiaire de la Direction de l’Urbanisme de la Ville en mars 2014, une consultation a été proposée sur l’avant-projet Ring aux Jeunes-Rives selon différentes modalités : une exposition, un questionnaire, l’animation des « midis de la participation » dans le cadre de l’exposition et un Livre d’Or. Le présent rapport consigne les résultats de cette consultation