De l’idée à l’oeuvre : Figures, fonctions, formes, langage dans la Notation I pour orchestre de Pierre Boulez

La transfiguration de quelques mesures de piano en un morceau pour grand orchestre fournit une bonne occasion de comprendre comment une petite idée musicale peut engendrer tout un univers sonore. Cet article montre comment Boulez crée la Notation I pour orchestre (1978) en composant l’aura de la Notation I pour piano (1945). La composition est réalisée à partir d’opérations déductives sur les caractéristiques structurelles des figures de piano, opérations qui permettent de définir des fonctions, puis de varier des formes et finalement de construire un langage. Le déploiement musical se présente alors comme intégralement sous-tendu par la tripartition anacrouse-accent-désinence, tripartition héritée de Messiaen mais que Boulez systématise en en faisant le principe d’articulation de tous les niveaux de la composition.The transfiguration of a few measures of a piano piece into an orchestral work offers a fine opportunity to understand how a little musical idea can generate an entire sound world. This article shows how Boulez created Notation I for orchestra (1978) by composing the aura of the first piano Notation (1945). The composition is created out of deductive operations of the structural characteristics of the piano figures, operations which allow for the definition of functions, and for the variation of forms, which, in the end, is used to construct a language. The entire musical canvas is then seen as being entirely subtended by the tripartite structure of anacrusis-accent-decay, a tripartition inherited from Messiaen, but which Boulez systematizes by making it a principle of articulation on all levels of the composition

Aix-en-Provence – Collège Mignet

Identifiant de l'opération archéologique : 8299 Date de l'opération : 2007 (SP) Inventeur(s) : Ratsimba Antoine (COL) ; Bonnet Stéphane (COL) Le projet d’extension du parking souterrain Mignet a entraîné la prescription d’une fouille préventive qui s’est déroulée du 9 avril au 12 juillet (BSR PACA, 2006 : 114). Cette opération fait suite à deux opérations préventives qui ont été réalisées dans l’enceinte du collège Mignet, en 1990 (dir. R. Chemin, AFAN ; NIL PACA,1990 : 68-69) puis en 2001 (d..

Iterative methods for scattering problems in isotropic or anisotropic elastic waveguides

International audienceWe consider the time-harmonic problem of the diffraction of an incident propagative mode by a localized defect, in an infinite straight isotropic elastic waveguide. We propose several iterative algorithms to compute an approximate solution of the problem, using a classical finite element discretization in a small area around the perturbation, and a modal expansion in unbounded straight parts of the guide. Each algorithm can be related to a so-called domain decomposition method, with or without an overlap between the domains. Specific transmission conditions are used, so that only the sparse finite element matrix has to be inverted, the modal expansion being obtained by a simple projection, using the Fraser bi-orthogonality relation. The benefit of using an overlap between the finite element domain and the modal domain is emphasized, in particular for the extension to the anisotropic case. The transparency of these new boundary conditions is checked for two- and three-dimensional anisotropic waveguides. Finally, in the isotropic case, numerical validation for two- and three-dimensional waveguides illustrates the efficiency of the new approach, compared to other existing methods, in terms of number of iterations and CPU time

275: Percutaneous insertion of a Melody valve in tricuspid position: technical aspects

Backgroundpercutaneous transcatheter heart valve replacement of aortic or pulmonary valve is established. Transcatheter atrioventricular valve replacement is been described. We report our experience focusing on the technical aspects.Methodswe retrospectively review the files of patients who received a transcatheter valve in tricuspid position between 2008 and 2012.ResultsFour patients were found. 3 had a heterograft (conduit of 14-mm, Sorin 33 et Edwards Perimount 33) and one had a connection between the RA and the RV infundibulum without a valve. Two patients had tricuspid regurgitation as a primary lesion, one had stenotic valve and the last one a mixted lesion. All successfully received a Melody valve from a femoral access. In patients with stenotic lesion, a predilatation using a high pressure balloon was performed before valve implant. In patients with regurgitation, the landing zone was calibrated using a low pressure balloon. These patients were presented to create a landing zone of adequate diameter. Melody valves were inserted using a 22-mm balloon catheter in 3 and a 24-mm in one. All but one were post-dilated. There was no significant regurgitation. The mean gradient across the tricuspid valve felt from 12 to 4.6-mmHg. One patient needed an epicardic pacemaker because of AV block following balloon dilatation. One patient required inotropic support and ventilation following the procedure but recovered after few days.ConclusionTranscatheter tricuspid valve insertion is feasible in patients with surgical hetero or homografts after a careful selection. The mechanism of dysfunction must be known. In case of stenosis or mixted lesions, the only question is to know if the stenosis could be relief. In case of regurgitation, it is very important to know the features of surgical substrats and to calibrate the tricuspid orifice. Finally, patients with inappropriate landing zone should be presented prior to valve insertion

The value chain approach in one health: Conceptual framing and focus on present applications and challenges

The value chain (VC) is a major operational concept for socioeconomic analysis at meso level. Widely mobilized in development practice, it is still undergoing conceptual and practical refining, e.g., to take account of environmental and social sustainability. Briefly, VC refers to a system of value creation through the full set of actors, links, technical and commercial activities and flows involved in the provision of a good or service on a market. In the past decade, this concept has been promoted in the management of animal health. In particular, the emergence of highly pathogenic avian influenza (HPAI) has triggered an interdisciplinary dynamic including VC analysis as a central tool. These efforts promoted participatory investigation methods in the analysis of health systems. Using qualitative and quantitative data, these methods acknowledge the usefulness of actors' involvement and knowledge, hence facilitating the transdisciplinarity needed for effective action. They fit into adaptive and action-oriented strategies, fostering stakeholders' participation. Recent research on HPAI surveillance in South-East Asia merged VC and participatory approaches to develop innovative tools for analyzing constraints to information flow. On-going interventions for HPAI prevention and control as well as the prevention of other emerging zoonotic risks in Africa are presently building on this VC framework to develop strategies for its application at national and regional scales. Based on the latter experiences, this article proposes a field-based perspective on VC applications to animal and public health systems, within a One Health approach responding to the overall challenge of complexity

The Halfspace Matching Method : a new method to solve scattering problem in infinite media

International audienceWe are interested in acoustic wave propagation in time harmonic regime in a two-dimensional medium which is a local perturbation of an infinite isotropic or anisotropic homogeneous medium. We investigate the question of finding artificial boundary conditions to reduce the numerical computations to a neighborhood of this perturbation. Our objective is to derive a method which can extend to the anisotropic elastic problem for which classical approaches fail. The idea consists in coupling several semi-analytical representations of the solution in halfspaces surrounding the defect with a Finite Element computation of the solution around the defect. As representations of the same function, they have to match in the infinite intersections of the halfspaces. It leads to a formulation which couples, via integral operators, the solution in a bounded domain including the defect and its traces on the edge of the halfspaces. A stability property is shown for this new formulation