Exchange Rates and the Canadian Economy

An objective assessment of the effects of the appreciation of the Canadian dollar in 2003 and 2004 on exports and imports requires a detailed review of the numerous other factors which may have been at play. Dion, Laurence, and Zheng discuss the influences that have affected Canada's international trade over the past two years, including exchange rate movements, global and sector-specific shocks, constraints on the domestic supply of a few products, and competition from emerging economies, most notably, China. The analysis is complemented with econometric models developed at the Bank which provide statistically valid estimates of the contribution of the Canadian-dollar appreciation to the recent developments in exports and imports.

An arbitrary Lagrangian-Eulerian finite element approach to non-steady state turbulent fluid flow with application to mould filling in casting

This is the pre-peer reviewed version of the following article : An arbitrary Lagrangian-Eulerian finite element approach to non-steady state turbulent fluid flow with application to mould filling in casting, Gaston L., Kamara A., Bellet M. International Journal for Numerical Methods in Fluids 34, 4 (2000) pages 341-369, which has been published in final form at http://dx.doi.org/10.1002/1097-0363(20001030)34:4%3C341::AID-FLD64%3E3.0.CO;2-KInternational audienceThis paper presents a two-dimensional Lagrangian-Eulerian finite element approach of non-steady state turbulent fluid flows with free surfaces. The proposed model is based on a velocity-pressure finite element Navier-Stokes solver, including an augmented Lagrangian technique and an iterative resolution of Uzawa type. Turbulent effects are taken into account with the k-epsilon two-equation statistical model. Mesh updating is carried out through an arbitrary Lagrangian-Eulerian (ALE) method in order to describe properly the free surface evolution. Three comparisons between experimental and numerical results illustrate the efficiency of the method. The first one is turbulent flow in an academic geometry, the second one is a mould filling in effective casting conditions and the third one is a precise confrontation to a water model

Appuis et obstacles dans l'usage didactique des modélisations d'accompagnement pour une éducation au développement durable

International audienceCompanion modelling1 associates simulation using a Multi agent system, a Geographical Information System and role playing in order to create a model and to simulate dynamics of eco-socio-systems. Their main aims are to help taking decision about complex problems related to management of resources, natural patrimonies and biodiversity. We have enlightened different supports and obstacles for their didactic transposition in vocational teaching in agriculture. The companion modellings can allow to sensitize to eco-socio-system dynamics ; their internal transposition is necessary to make them considered by the learner as a mirror of the reality and to allow him to be involved and to change during the game.Les modélisations d'accompagnement, en tentant de prendre en compte la dynamique d'écosocio-systèmes, se veulent être un outil d'aide à la décision dans le cadre de problématiques complexes telles que la gestion de la biodiversité. Conçues par et avec les acteurs du territoire, elles associent un système multi-agent, un jeu de rôle et un système d'information géographique qui visualise l'évolution du territoire en fonction des choix pris par les acteurs durant le jeu. Nous avons mis en évidence différents appuis et obstacles à la transposition didactique dont elles font l'objet dans l'enseignement agricole. Si les modélisations peuvent permettre de répondre à des objectifs de sensibilisation relatifs au fonctionnement d'écosocio-systèmes complexes, une transposition interne se justifie pour leur permettre d'être conçues comme miroir d'une réalité, pouvant permettre l'implication et l'évolution de l'élève dans le jeu

Biology of the immunomodulatory molecule HLA-G in human liver diseases.

International audienceThe non-classical human leukocyte antigen-G, HLA-G, plays an important role in inducing tolerance, through its immunosuppressive effects on all types of immune cells. Immune tolerance is a key issue in the liver, both in liver homeostasis and in the response to liver injury or cancer. It would therefore appear likely that HLA-G plays an important role in liver diseases. Indeed, this molecule was recently shown to be produced by mast cells in the livers of patients infected with hepatitis C virus (HCV). Furthermore, the number of HLA-G-positive mast cells was significantly associated with fibrosis progression. The generation of immune tolerance is a role common to both HLA-G, as a molecule, and the liver, as an organ. This review provides a summary of the evidence implicating HLA-G in liver diseases. In the normal liver, HLA-G transcripts can be detected, but there is no HLA-G protein. However, HLA-G protein is detectable in the liver tissues and/or plasma of patients suffering from hepatocellular carcinoma, hepatitis B or C, or visceral leishmaniasis and in liver transplant recipients. The cells responsible for producing HLA-G differ between diseases. HLA-G expression is probably induced by microenvironmental factors, such as cytokines. The expression of HLA-G receptors, such as ILT2, ILT4, and KIRD2L4, on liver cells has yet to be investigated, but these receptors have been detected on all types of immune cells, and such cells are present in liver. The tolerogenic properties of HLA-G explain its deleterious effects in cancers and its beneficial effects in transplantation. Given the key role of HLA-G in immune tolerance, new therapeutic agents targeting HLA-G could be tested for the treatment of these diseases in the future

A Schwarz Waveform Relaxation Method for Advection—Diffusion—Reaction Problems with Discontinuous Coefficients and Non-matching Grids

International audienceWe present a non-overlapping Schwarz waveform relaxation method for solving advection-reaction-diffusion problems in heterogeneous media. The do-main decomposition method is global in time, which permits the use of different time steps in different subdomains. We determine optimal non-local, and optimized Robin transmission conditions. We also present a space-time finite volume scheme es-pecially designed to handle such transmission conditions. We show the performance of the method on an example inspired from nuclear waste disposal simulations

A study of composite material damage induced by laser shock waves

A laser shock wave technique has been used to study the damage tolerance of T800/M21 CFRP (Carbon Fiber Reinforced Polymer) composite material with different lay_ups. Different levels of damage have been created according to various laser irradiation conditions. Several characterization methods such as Optical Microscopy, X-ray Radiography, or Interferometric Confocal Microscopy have been used to quantify these defects. The nature of the defects induced by the shock wave propagation has been studied. The sensitivity of the composite material damage to the shock conditions has been shown and quantified. Moreover, the experimental results gathered with each technique have been compared to each other and it leads to a better understanding of the CFRP behavior under high dynamic loading. These original results have enabled the definition of a specific damage criterion for CFRP under dynamic loading