Domaines « vides » et structuration morphologique de l’agglomération montréalaise

L'avenir de l'agglomération montréalaise inquiète. Plusieurs s'en préoccupent. Mais s'interroge-t-on suffisamment sur le fait que la recherche de solutions a rarement suscité une remise en question de la manière dont le problème est posé depuis près de deux décennies? Se pourrait-il, par exemple, que les nombreux domaines « vides » de l'agglomération ne soient pas tant les résidus d'un étalement incontrôlé que des formes structurantes? C'est l'hypothèse qui est proposée. L'identification d'une structure de positions, contraignante à l'égard de l'établissement, permet par ailleurs de poser le problème du zonage, instrument privilégié d'un urbanisme en crise. Loin d'en justifier le rejet, la présente étude en montrera au contraire la pertinence, pourvu qu'on tienne mieux compte de sa prétention originelle, qui était de protéger les propriétés existantes bien plus que d'attribuer des utilités aux positions non encore occupées.The Montréal region is a source of concern to many. In their search for solutions over the past two decades, have those concerned considered the possibility that the problem has been posed correctly? Is it possible, for example, that the many "empty" spaces result less from urban sprawl than from structural factors? This is the hypothesis of this work. The identification of an abstract structure of locations which constrain settlement will call into question the policy of zoning, the main tool of urban planning. Zoning is not rejected, however. On the contrary, the study demonstrates its validity, provided that its use aims at protecting existing properties

How to build an average model when samples are variably incomplete? Application to fossil data

International audienceIn paleontology, incomplete samples with small or large missing parts are frequently encountered. For example,dental crowns, which are widely studied in paleontology because of their potential interest in taxonomic and phylogenetic analyses, are nearly systematically affected by a variable degree of wear that alters considerably their shape. It is then difficult to compute a significant reference surface model based on classical methods which are used to build atlases from set of samples. In this paper, we present a general approach to deal with the problem of estimating an average model from a set of incomplete samples. Our method is based on a state-of-the-art non-rigid surface registration algorithm. In a first step, we detect missing parts which allows one to focus only on the common parts to get an accurate registration result. In a second step, we try to build average model of the missing parts by using information which is available in a subset of the samples. We specifically apply our method on teeth, and more precisely on the surface in between dentine and enamel issues (EDJ). We investigate the robustness and accuracy properties of the methods on a set of artificial samples representing a high degree of incompleteness. We compare the reconstructed complete shape to a ground-truth dataset. We then show some results on real data

Effects of eight neuropsychiatric copy number variants on human brain structure

peer reviewedMany copy number variants (CNVs) confer risk for the same range of neurodevelopmental symptoms and psychiatric conditions including autism and schizophrenia. Yet, to date neuroimaging studies have typically been carried out one mutation at a time, showing that CNVs have large effects on brain anatomy. Here, we aimed to characterize and quantify the distinct brain morphometry effects and latent dimensions across 8 neuropsychiatric CNVs. We analyzed T1-weighted MRI data from clinically and non-clinically ascertained CNV carriers (deletion/duplication) at the 1q21.1 (n = 39/28), 16p11.2 (n = 87/78), 22q11.2 (n = 75/30), and 15q11.2 (n = 72/76) loci as well as 1296 non-carriers (controls). Case-control contrasts of all examined genomic loci demonstrated effects on brain anatomy, with deletions and duplications showing mirror effects at the global and regional levels. Although CNVs mainly showed distinct brain patterns, principal component analysis (PCA) loaded subsets of CNVs on two latent brain dimensions, which explained 32 and 29% of the variance of the 8 Cohen’s d maps. The cingulate gyrus, insula, supplementary motor cortex, and cerebellum were identified by PCA and multi-view pattern learning as top regions contributing to latent dimension shared across subsets of CNVs. The large proportion of distinct CNV effects on brain morphology may explain the small neuroimaging effect sizes reported in polygenic psychiatric conditions. Nevertheless, latent gene brain morphology dimensions will help subgroup the rapidly expanding landscape of neuropsychiatric variants and dissect the heterogeneity of idiopathic conditions. © 2021, The Author(s)

Effects of eight neuropsychiatric copy number variants on human brain structure

Many copy number variants (CNVs) confer risk for the same range of neurodevelopmental symptoms and psychiatric conditions including autism and schizophrenia. Yet, to date neuroimaging studies have typically been carried out one mutation at a time, showing that CNVs have large effects on brain anatomy. Here, we aimed to characterize and quantify the distinct brain morphometry effects and latent dimensions across 8 neuropsychiatric CNVs. We analyzed T1-weighted MRI data from clinically and non-clinically ascertained CNV carriers (deletion/duplication) at the 1q21.1 (n = 39/28), 16p11.2 (n = 87/78), 22q11.2 (n = 75/30), and 15q11.2 (n = 72/76) loci as well as 1296 non-carriers (controls). Case-control contrasts of all examined genomic loci demonstrated effects on brain anatomy, with deletions and duplications showing mirror effects at the global and regional levels. Although CNVs mainly showed distinct brain patterns, principal component analysis (PCA) loaded subsets of CNVs on two latent brain dimensions, which explained 32 and 29% of the variance of the 8 Cohen’s d maps. The cingulate gyrus, insula, supplementary motor cortex, and cerebellum were identified by PCA and multi-view pattern learning as top regions contributing to latent dimension shared across subsets of CNVs. The large proportion of distinct CNV effects on brain morphology may explain the small neuroimaging effect sizes reported in polygenic psychiatric conditions. Nevertheless, latent gene brain morphology dimensions will help subgroup the rapidly expanding landscape of neuropsychiatric variants and dissect the heterogeneity of idiopathic conditions

Les routes touristiques à thème : entre marketing territorial et valorisation identitaire

Le Québec s’est timidement mis à l’heure des routes touristiques à thème. On assiste en effet à une augmentation significative de telles routes touristiques depuis un peu plus d’une décennie. Le phénomène n’est pas exclusif au Québec, bien au contraire. L’Europe propose à elle seule plusieurs centaines de routes thématiques. Constituent-elles une nouveauté ou s’agit-il simplement d’un changement d’appellation répondant à un effet de mode ? En fait, il n’est pas facile de répondre à cette question, tant l’appellation semble être accolée à des réalités fort diverses, pour ne par dire disparates. La création des routes touristiques à thème participe, depuis plus d’une décennie, d’un vaste mouvement d’affirmation identitaire et de valorisations territoriales fortement enracinées. La désignation de telles routes constitue-t’ elle pour autant une formule privilégiée de mobilisation des acteurs, de développement des activités et d’aménagement du territoire conséquent ? La multiplication des créations pourrait le laisser croire, d’autant plus que les initiatives sont habituellement portées par le milieu dont les acteurs doivent s’être préalablement mobilisés. C’est donc que les projets doivent trouver un écho favorable dans les collectivités territoriales. Mais, par delà une éventuelle banalisation, n’existe-t-il pas un risque non moins préoccupant d’une discordance croissante entre les désignations et l’intérêt objectif des territoires visés ? Comment éviter en effet qu’une collectivité territoriale moins bien nantie puise allègrement dans l’arsenal du marketing territorial pour évoquer une réalité qui soit tout… sauf réelle