Une relecture juridique de "La chanson de Roland"(*)

(*)Ce texte reprend et résume un article que nous avions donné dans une revue un peu confidentielle: "Lovaina. Critique, idées et tendances du temps", 15e année, 3e trimestre 1957, nº 44, pp. 27-43, sous le titre, un rien provocant: "Roland, le Traître..

Extremely Luminous Water Vapor Emission from a Type 2 Quasar at Redshift z = 0.66

A search for water masers in 47 Sloan Digital Sky Survey Type 2 quasars using the Green Bank Telescope has yielded a detection at a redshift of z = 0.660. This maser is more than an order of magnitude higher in redshift than any previously known and, with a total isotropic luminosity of 23,000 L_sun, also the most powerful. The presence and detectability of water masers in quasars at z ~ 0.3-0.8 may provide a better understanding of quasar molecular tori and disks, as well as fundamental quasar and galaxy properties such as black hole masses. Water masers at cosmologically interesting distances may also eventually provide, via direct distance determinations, a new cosmological observable for testing the reality and properties of dark energy, currently inferred primarily through Type 1a supernova measurements.Comment: 8 pages including 1 figure; accepted for publication in ApJ Letter

Le Lancelot-Guenièvre de Jean Cocteau

Au firmament des couples d’amants célèbres, à côté de Tristan et d’Yseult, d’Abélard et Héloïse, de Roméo et Juliette, scintille aussi, de presque égale magnitude, cette étoile double de l’amour courtois : Lancelot et Guenièvre. Faut-il rappeler ce qu’en rapporte la tradition légendaire ? Lancelot du Lac s’est emparé du château de la Douloureuse Garde. Le roi Arthur y vient. À ses côtés, Lancelot aperçoit la reine. À l’instant, du premier regard, il tombe en extase d’amour, perdant conscience..

Agriculture et biodiversité. Valoriser les synergies

Que sait-on aujourd'hui des impacts, positifs et négatifs, de l’agriculture sur la biodiversité ? Quels services la biodiversité peut-elle apporter à l’agriculture, et à quelle hauteur de performance ? Comment favoriser au champ les synergies entre agriculture et biodiversité ? Quels instruments de politiques publics, économiques et juridiques, faut-il mettre en place pour promouvoir ces interactions ? Ces questions ont mobilisé un groupe pluridisciplinaire d’experts (écologues, agronomes, microbiologistes, spécialistes de santé végétale, économistes, juristes, sociologues), de différentes institutions (Inra, CNRS, IRD, Universités, Ecoles supérieures agronomiques) en France et à l’étrange

Determining anion-quadrupole interactions among protein, DNA, and ligand molecules

Background An extensive search through the Protein Databank (about 4500 nonredundant structures) was previously completed within our lab to analyze the energetic and geometric characteristics of an understudied molecular interaction known as an anion-quadrupole (AQ) interaction. Such an interaction occurs when the positively charged edge of an aromatic ring, resulting from a quadruple moment (i.e., a dual dipole moment), renders the aromatic molecule noncovalently bound to a nearby anionic molecule. The study considered a very limited scenario of molecules that can participate in AQ interactions, consisting of the phenyl group of a phenylalanine (phe) amino acid as the aromatic participant and the carboxylate group of an aspartate (asp) or glutamate (glu) amino acid as the anionic participant. The results revealed anion-quadrupole pairs to be prevalent within most of the protein structures. It was also observed that the interaction energy for AQ pairs was heavily dependent on the angle between the anion and plane of the aromatic ring, favoring a more planar interaction. In light of these critical observations being made from such a limited scenario, only phe-glu and phe-asp pairs and in a reduced sample set of the PDB, we are now continuing this work of identifying AQ interactions using a greatly expanded strategy. We are following these four aims: 1. Optimizing the AQ-search program to run in a semi-parallel fashion and on a large cluster of processors in order to handle larger analyses, 2. Adding to our search additional anionic participants which will include non-protein structures such as DNA and small ligands, 3. Studying a subset of the AQ pairs with molecular dynamics simulations in buried and solvent exposed environments to observe non-static behavioral traits as well as the reproducibility of AQ interactions by force field parameters. 4. Building an online database for public access to our data and search program. Acknowledgments We would like to acknowledge the NSF-IGERT traineeship, Scalable Computing and Leading Edge Innovative Technologies (SCALE-IT), for providing the resources for this project

Semantic mutation testing

This is the Pre-print version of the Article. The official published version can be obtained from the link below - Copyright @ 2011 ElsevierMutation testing is a powerful and flexible test technique. Traditional mutation testing makes a small change to the syntax of a description (usually a program) in order to create a mutant. A test suite is considered to be good if it distinguishes between the original description and all of the (functionally non-equivalent) mutants. These mutants can be seen as representing potential small slips and thus mutation testing aims to produce a test suite that is good at finding such slips. It has also been argued that a test suite that finds such small changes is likely to find larger changes. This paper describes a new approach to mutation testing, called semantic mutation testing. Rather than mutate the description, semantic mutation testing mutates the semantics of the language in which the description is written. The mutations of the semantics of the language represent possible misunderstandings of the description language and thus capture a different class of faults. Since the likely misunderstandings are highly context dependent, this context should be used to determine which semantic mutants should be produced. The approach is illustrated through examples with statecharts and C code. The paper also describes a semantic mutation testing tool for C and the results of experiments that investigated the nature of some semantic mutation operators for C

Barriers to Systematic Model Transformation Testing

International audienceModel Driven Engineering (MDE) techniques support extensive use of models in order to manage the increasing complexity of software systems. Approp riate abstractions of software system elements can ease reasoning and understand ing and thus limit the risk of errors in large systems. Automatic model transfor mations play a critical role in MDE since they automate complex, tedious, error- prone, and recurrent software development tasks. A fault in a transformation can introduce a fault in the transformed model, which if undetected and not removed , can propagate to other models in successive development steps. As a fault prop agates further, it becomes more difficult to detect and isolate. Since model tra nsformations are meant to be reused, faults present in them may result in many f aulty models. Model transformations constitute a class of programs with unique c haracteristics that make testing them challenging. The complexity of input and o utput data, lack of model management tools, and the heterogeneity of transformat ion languages pose special problems to testers of transformations. In this paper we identify current model transformation characteristics that contribute to the difficulty of systematically testing transformations. We present promising solu tions and propose possible ways to overcome these barriers

A Search for H2O Megamasers in High-z Type-2 AGNs

We report a search for H2O megamasers in 274 SDSS type-2 AGNs (0.3 < z < 0.83), half of which can be classified as type-2 QSOs from their [OIII] 5007 luminosity, using the Robert C. Byrd Green Bank Telescope (GBT) and the Effelsberg 100-m radio telescope. Apart from the detection of the extremely luminous water vapor megamaser SDSS J080430.99+360718.1, already reported by Barvainis & Antonucci (2005), we do not find any additional line emission. This high rate of non-detections is compared to the water maser luminosity function created from the 78 water maser galaxies known to date and its extrapolation towards the higher luminosities of "gigamasers" that we would have been able to detect given the sensitivity of our survey. The properties of the known water masers are summarized and discussed with respect to the nature of high-z type-2 AGNs and megamasers in general. In the appendix, we list 173 additional objects (mainly radio galaxies, but also QSOs and galaxies) that were observed with the GBT, the Effelsberg 100-m radio telescope, or Arecibo Observatory without leading to the detection of water maser emission.Comment: 28 pages, 3 figures. Accepted for publication in the Astrophysical Journa

Reifying Concurrency for Executable Metamodeling

International audienceCurrent metamodeling techniques can be used to specify the syntax and semantics of domain specific modeling languages (DSMLs). However, there is currently very little support for explicitly specifying concurrency semantics using metamodels. Often, such semantics are provided through implicit concurrency models embedded in the underlying execution environment supported by the language workbench used to implement the DSMLs. The lack of an explicit concurrency model has several drawbacks: it not only prevents from developing a complete understanding of the behavioral semantics, it also prevents development of effective concurrency-aware analysis techniques, and effective techniques for producing semantic variants in the cases where the semantic base has variation points. This work reifies concurrency as a metamodeling facility, leveraging formalization work from the concurrency theory and models of computation (MoC) community. The essential contribution of this paper is a proposed language workbench for binding domain-specific concepts and models of computation through an explicit event structure at the metamodel level. We illustrate these novel metamodeling facilities for designing two variants of a concurrent and timed final state machine, and provide other experiments to validate the scope of our approach

Temporo-Spatial Dynamics of Event-Related EEG Beta Activity during the Initial Contingent Negative Variation

In the electroencephalogram (EEG), early anticipatory processes are accompanied by a slow negative potential, the initial contingent negative variation (iCNV), occurring between 500 and 1500 ms after cue onset over prefrontal cortical regions in tasks with cue-target intervals of about 3 s or longer. However, the temporal sequence of the distributed cortical activity contributing to iCNV generation remains unclear. During iCNV generation, selectively enhanced low-beta activity has been reported. Here we studied the temporal order of activation foci in cortical regions assumed to underlie iCNV generation using source reconstruction of low-beta (13–18 Hz) activity. During the iCNV, elicited by a cued simple reaction-time task, low-beta power peaked first (750 ms after cue onset) in anterior frontal and limbic regions and last (140 ms later) in posterior areas. This activity occurred 3300 ms before target onset and provides evidence for the temporally ordered involvement of both cognitive-control and motor-preparation processes already at early stages during the preparation for speeded action