Attraction et rétention des immigrants récents hors Montréal : une analyse longitudinale par cohorte d’arrivée au Québec (1992, 1996, 2000 et 2004)

Cette étude s’intéresse à l’évolution de la capacité du Québec hors Montréal à attirer et retenir les immigrants depuis l’introduction d’un axe de régionalisation dans la politique québécoise d’immigration au début des années 1990. À partir d’une exploitation longitudinale du Fichier d’inscription des personnes assurées de la Régie de l’assurance maladie du Québec, nous avons reconstruit jusqu’en 2007 les trajectoires résidentielles de quatre cohortes d’immigrants admises au Québec entre 1992 et 2004. Nos résultats montrent que la présence d’immigrants hors Montréal est davantage tributaire du choix du premier lieu de résidence que de la migration secondaire interne. Tant la répartition initiale que les échanges migratoires subséquents ont toutefois connu des changements profitables au Québec hors Montréal qui reçoit une part accrue des nouveaux immigrants et qui est devenu plus attractif auprès des immigrants de Montréal. Les résultats précisent aussi qu’à l’extérieur de Montréal, ce sont les principaux centres urbains (Québec, Gatineau et Sherbrooke) qui exercent la plus forte attraction, mais que des agglomérations de taille plus réduite ont considérablement amélioré leur bilan.This article examines the evolution of the capacity of the areas of Québec outside Montréal to attract and retain immigrants since initiatives for regionalization became part of Québec’s immigration policy at the beginning of the 1990s. Through the longitudinal use of FIPA, the insured persons registration file of the Régie de l’assurance maladie du Québec, we reconstructed up until 2007 the residential trajectories of four immigrant cohorts admitted to Québec between 1992 and 2004. Our findings show that the presence of immigrants outside Montréal depends more on the choice of first place of residence than on internal secondary migration. However, both initial distribution and subsequent migratory exchanges with Montréal profited the rest of Québec, which welcomed a higher share of new immigrants and became more attractive to Montréal immigrants. The findings also show that outside Montréal it is the main urban centres (Québec, Gatineau and Sherbrooke) that are exerting the strongest pull on immigrants but that smaller urban areas have improved their situations considerably

Cerebrovascular and blood-brain barrier impairments in Huntington's disease: Potential implications for its pathophysiology: Vascular impairments in HD

ObjectiveAlthough the underlying cause of Huntington's disease (HD) is well established, the actual pathophysiological processes involved remain to be fully elucidated. In other proteinopathies such as Alzheimer's and Parkinson's diseases, there is evidence for impairments of the cerebral vasculature as well as the blood–brain barrier (BBB), which have been suggested to contribute to their pathophysiology. We investigated whether similar changes are also present in HD.MethodsWe used 3‐ and 7‐Tesla magnetic resonance imaging as well as postmortem tissue analyses to assess blood vessel impairments in HD patients. Our findings were further investigated in the R6/2 mouse model using in situ cerebral perfusion, histological analysis, Western blotting, as well as transmission and scanning electron microscopy.ResultsWe found mutant huntingtin protein (mHtt) aggregates to be present in all major components of the neurovascular unit of both R6/2 mice and HD patients. This was accompanied by an increase in blood vessel density, a reduction in blood vessel diameter, as well as BBB leakage in the striatum of R6/2 mice, which correlated with a reduced expression of tight junction‐associated proteins and increased numbers of transcytotic vesicles, which occasionally contained mHtt aggregates. We confirmed the existence of similar vascular and BBB changes in HD patients.InterpretationTaken together, our results provide evidence for alterations in the cerebral vasculature in HD leading to BBB leakage, both in the R6/2 mouse model and in HD patients, a phenomenon that may, in turn, have important pathophysiological implications. Ann Neurol 2015;78:160–17