Renewed uplift of the Central Andes Forearc revealed by coastal evolution during the Quaternary

Accepted Manuscript for publication in Earth and Planetary Science LettersMost of the Pacific coast of the Central Andes, between 15°S and 30°S, displays a wide (a couple of kilometres) planar feature, gently dipping oceanwards and backed by a cliff. This morphology, usually of marine orgin, is called rasa, and argues for a recent and spatially continuous uplift of the margin over the 1,500-km-long coastal region we describe. The cliff foot is found at a similar elevation (~110 m amsl) all over the studied area, with the exception of peninsulas such as the Mejillones Peninsula. The compilation of published chronological data and the extrapolation of re-appraised uplift rates provide evidence for a common cliff foot age of around 400 ka (i.e., Marine Isotopic Stage MIS 11). This, together with other geological constraints, indicates a Quaternary renewal of uplift in the Central Andes forearc after a late Pliocene quiescence or subsidence

Discovery of a VHE gamma-ray source in the W51 region

International audienceThe W51 region has been intensively studied at several wavelengths and is known to host high energy phenomena in which high energy particle acceleration is believed to occur. The H.E.S.S. telescope array observed this region in 2007 and 2008 and has discovered a new source of VHE °- rays, HESS J1923+141. The possible origins of this emission are discussed

Linear collider test facility: ATF2 final focus active stabilisation pertinence

International audienceBeam motion at the Interaction Point (IP) of ATF2 has to be less than 10nm relative to the instrumentation used for measurements. Due to ground motion (GM), the beam can pass off-axis through the quadrupoles of the beam line and hence be deflected. It was shown in previous studies that good spatial coherence of the GM over a few meters makes the relative motion of the Final Doublets (FD) small enough for the tolerance not to be exceeded. However, since the coherence drops rapidly with distance, other quadrupoles further upstream can be expected to induce significant effects. In this paper, an evaluation taking into account all ATF2 quadrupoles is presented, using a GM generator with parameters tuned to dedicated measurements done recently along the ATF2 beam line and propagating to the IP with the optical transfer matrices. It was shown that although large IP beam motion can indeed be induced by some specific upstream quadrupoles, the combined effect of all is small because of compensations. The tolerance can thus be achieved without specially stabilising these quadrupoles

Convolution lambda-bar-mu-calculus

International audienceWe define an extension of Herbelin's lambda-bar-mu-calculus, introducing a product operation on contexts (in the sense of lists of arguments, or stacks in environment machines), similar to the convolution product of distributions. This is the computational couterpart of some new semantical constructions, extending models of Ehrhard-Regnier's differential interaction nets, along the lines of Laurent's polarization of linear logic. We demonstrate this correspondence by providing this calculus with a denotational semantics inside a lambda-model in the category of sets and relations

Automatic Package Coupling and Cycle Minimization

International audienceObject-oriented (OO) software is usually organized into subsystems using the concepts of package or module. Such modular structure helps applications to evolve when facing new requirements. However, studies show that as software evolves to meet requirements and environment changes, modularization quality degrades. To help maintainers improve the quality of software modularization we have designed and implemented a heuristic search-based approach for automatically optimizing inter-package connectivity (i.e., dependencies). In this paper, we present our approach and its underlying techniques and algorithm. We show through a case study how it enables maintainers to optimize OO package structure of source code. Our optimization approach is based on Simulated Annealing technique

News from Virgo: present status and future upgrades

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Hannibal's trek across the alps: Geomorphological Analysis of sites of geoarchaeological interest

International audienceA ~2200 year-old question related to Hannibal's invasion route across the Alps into Italia, has been argued by classicists without recovery of material evidence. A comparison of topographical descriptions in the ancient literature with environmental parameters in the Alps, attempted here for the first time, provides a database against which various pathways can be assessed. Identification of sites using geological, geomorphological, astronomical, chemical and petrological methods leads to the exclusion of certain transit points and targeting of others where geoarchaeological excavation might yield important evidence related to the military culture of ancient Carthage

Hilbert domains quasi-isometric to normed vector spaces

We prove that a Hilbert domain which is quasi-isometric to a normed vector space is actually a convex polytope

Les sentiers d'interprétation glaciaire : des outils de valorisation différenciée des glaciers et de leur territoire

National audienceLes glaciers peuvent se révéler de remarquables géosites, dont l'importance sociétale se renforce avec le réchauffement global qui menace leur existence dans les Alpes. Parmi l'ensemble de l'offre en matière de sentier d'interprétation au coeur du massif alpin, 30 réalisations permettent de découvrir autant de vallées glaciaires, abritant toujours un glacier. L'analyse de la répartition spatiale de ces sentiers montre que des pays comme l'Autriche et l'Italie sont particulièrement actifs dans la création de ce type d'offre écotouristique qui allie des pratiques sportives de pleine nature respectueuses de l'environnement à la découverte de celui-ci. Les jeux d'acteurs à l'origine de ces créations permettent d'établir une typologie expliquant en partie la répartition observée. L'analyse qualitative des sentiers eux-mêmes ainsi que des outils de médiation produits afin de guider le randonneur nous permettra de mieux cerner les objectifs poursuivis par les concepteurs et donc les messages qu'ils cherchent à faire passer auprès du public