Introduction review on cosmology with Type Ia supernovae

In this short review, some key aspects of the cosmology with type Ia supernovae are discussed in light of the recent results of high redshift surveys. The interpretation of SNe colours, the impact of calibration and the recent developments in the tests for an evolution of the population with redshift are addressed

The Transformative Role of Telemedicine on Coordination: A Practice Approach

Delivering coordinated care at a distance challenges work practices and interprofessional collaboration. Using a case study methodology, we analyzed how three occupational groups, pathologists, technologists, and surgeons, coordinate work during the deployment of a major telepathology network in Eastern Canada. The aim of this study is to determine the extent to which and how telemedicine modifies coordination practices. \ \ Transformations emerged from our in-depth case analysis around three aspects of coordination: predictability, common understanding and accountability. First, predictability relied on routines in traditional settings, but shifted to a reliance on plans and rules in a telemedicine setting. Second, common understanding of the task shifted from relying on familiarity between stakeholders to an emphasis on standards. Third, accountability became less collective and more individual and contractual in a telemedicine setting, resulting in more marked boundaries between professional groups. Finally, proximity remained a determinant of accountability in telemedicine contexts, regardless of organizational arrangements. Implications for research and practice are discussed

Dynamics of rational symplectic mappings and difference Galois theory

In this paper we study the relationship between the integrability of rational symplectic maps and difference Galois theory. We present a Galoisian condition, of Morales-Ramis type, ensuring the non-integrability of a rational symplectic map in the non-commutative sense (Mishchenko-Fomenko). As a particular case, we obtain a com- plete discrete analogue of Morales-Ramis Theorems for non-integrabi- lity in the sense of Liouville

Pouvoir et démocratie dans une congrégation religieuse féminine

Pouvoir et démocratie dans une congrégation religieuse féminine. Guy Michelat, Julien Potel. Dans une congrégation religieuse féminine où le principe « autorité-obéissance » est fondamental, quelle est la part de la « démocratie » ? Les élections au Chapitre, assemblée collégiale représentative de toutes les sœurs de la Province, se font en trois étapes : nomination, acceptation de candidature, élection proprement dite. À chacune de ces étapes on relève l'importance des mêmes facteurs : origines sociales, niveau de diplômes, responsabilités exercées. Le résultat est que plus on monte dans la hiérarchie, plus la composition sociale tend à s'écarter de celle de la base. Si le système d'autorité traditionnel de l'Église se maintient malgré d'importants changements intervenus après le concile Vatican II, la participation des sœurs à la vie de la Congrégation est réelle, mais, de même que dans d'autres organisations ou dans l'ensemble de la société, le processus de sélection sociale des élites, fondé sur la compétence que les autres (et soi-même) attribuent aux origines sociales et au capital scolaire, se renforce progressivement à l'intérieur même de la Congrégation

Cross section measurements of the reactions induced by deuteron particles on ¹³C

Nuclear reactions induced by deuterons have been found to be an ideal analysis tool for depth profiling of light elements in the first microns of materials. In particular, the nonresonant nuclear reactions (d, p), (d, α) and (d, t) are well adapted to determine depth distributions of C and C in a single measurement. Nevertheless, only the cross section of the C(d, p)C nuclear reaction is well known for various experimental configurations. Thus, we measured the differential cross sections of the C(d, p)C, C(d, α)B, C(d, α)B and C(d, t)C nuclear reactions. A thin C foil (83 nm thick) was used and the measurements were performed at deuteron energies from 0.5 to 1.65 MeV for different laboratory angles of detection (135°, 150° and 165° with respect to the incident beam). Then, the results obtained in this work were compared to cross sections measured by Marion and Weber for a detection angle of 135°. © 2006 Elsevier B.V. All rights reserved

Quantum transport of slow charge carriers in quasicrystals and correlated systems

We show that the semi-classical model of conduction breaks down if the mean free path of charge carriers is smaller than a typical extension of their wavefunction. This situation is realized for sufficiently slow charge carriers and leads to a transition from a metallic like to an insulating like regime when scattering by defects increases. This explains the unconventional conduction properties of quasicrystals and related alloys. The conduction properties of some heavy fermions or polaronic systems, where charge carriers are also slow, present a deep analogy.Comment: 4 page

Formation of carbon nitride compounds during successive implantations in copper

Copper substrates are successively implanted with carbon and nitrogen (C and N) at high fluences (5 × 10 and 1 × 10 at. cm, respectively) in order to synthesize specific carbon nitride compounds. The concentration as well as the depth distribution of carbon C and nitrogen N are determined using non resonant nuclear reactions induced by a 1.05 MeV deuteron beam. The use of (d,p) and (d,α) reactions allows us to profile both C and N elements with a single and relatively rapid measurement and a quite good resolution. The bonded states of carbon and nitrogen are studied as a function of depth by X-ray photoelectron spectroscopy (XPS). The curve fitting of the C 1s and N 1s photopeaks shows that carbon and nitrogen atoms exist in different chemical states depending on the analysis depth, which correspond to specific kinds of chemical bonds. At least two characteristic C-N bonds are detected indicating that different carbon nitride compounds have been formed during the implantations. © 2005 Elsevier B.V. All rights reserved

Vision-based macroscopic pedestrian models

International audienceWe propose a hierarchy of kinetic and macroscopic models for a system consisting of a large number of interacting pedestrians. The basic interaction rules are derived from earlier work where the dangerousness level of an interaction with another pedestrian is measured in terms of the derivative of the bearing angle (angle between the walking direction and the line connecting the two subjects) and of the time-to-interaction (time before reaching the closest distance between the two subjects). A mean-field kinetic model is derived. Then, three different macroscopic continuum models are proposed. The first two ones rely on two different closure assumptions of the kinetic model, respectively based on a monokinetic and a von Mises-Fisher distribution. The third one is derived through a hydrodynamic limit. In each case, we discuss the relevance of the model for practical simulations of pedestrian crowds