Geographical Features vs. Institutional Factors : New Perspectives on the Growth of Africa and Middle-East

Economic Research Forum Working paper n°490International audienceThis paper examines Africa's and Middle East's growth performance for the period 1990- 2005. It employs a Bayesian Model Averaging method that constructs estimates as a weighted average of Spatial Autoregressive estimates for every possible combination of included variables. One of the results of the paper is that the inclusion of spatial dependencies has a direct impact on the determinants of growth in Africa and Middle-East. Indeed, the methodology used in the paper offers an interesting response to the institution/geography debate on the explanation of growth and development. In particular, our methodology allows a selection of the institutional variables that count to explain low development since the geographical variables are partially integrated in the spatial dependence effect

Le développement de la compétence à écrire en langue première et en langue seconde à la fin du primaire dans des contextes d’intensification de l’enseignement de la langue seconde

Au Québec, un nombre de plus en plus important d’écoles organisent un apprentissage intensif de l’anglais en tant que langue seconde durant la sixième primaire. Nous présentons ici les premiers résultats d’une étude qui porte sur l’impact de cet apprentissage intensif sur le développement de la compétence d’écriture en français langue d’enseignement et en anglais langue seconde. Les élèves de cinq classes (n= 105) ont passé à trois reprises (début, milieu et fin de l’année scolaire) un test standardisé (WIAT-II) visant à mesurer leur compétence en écriture dans les deux langues. Les résultats obtenus à ces tests indiquent que l’ensemble des élèves manifeste des progrès en termes de performance globale en écriture tant en français qu’en anglais. Des variations entre l’évolution des performances en L1 ou L2 sont repérables selon les sous-composantes du test. Certaines différences apparaissent également selon le modèle d’intensification de l’apprentissage auquel les élèves sont exposés.Abstract : An increasing number of schools in Québec an offer students the opportunity to follow an intensive English as a second language program during their sixth year of elementary school. In this chapter we present the first results of a study that examines the impact of this intensive model of learning on the development of writing competence in French as the language of instruction and in English as a second language. Students in five classes (n = 105) completed a standardized test (WIAT-II) three times (beginning, middle and end of school year) to measure their writing skills in both languages. The results of these tests indicate that the students show progress in terms of overall performance in writing in both French and English. Variations in first and second language writing development are apparent when some subtest scores are examined. Certain differences are also observed when we compare the different models of intensive second language instruction that students were exposed to

Dating and localizing an invasion from post-introduction data and a coupled reaction-diffusion-absorption model

Invasion of new territories by alien organisms is of primary concern for environmental and health agencies and has been a core topic in mathematical modeling, in particular in the intents of reconstructing the past dynamics of the alien organisms and predicting their future spatial extents. Partial differential equations offer a rich and flexible modeling framework that has been applied to a large number of invasions. In this article, we are specifically interested in dating and localizing the introduction that led to an invasion using mathematical modeling, post-introduction data and an adequate statistical inference procedure. We adopt a mechanistic-statistical approach grounded on a coupled reaction-diffusion-absorption model representing the dynamics of an organism in an heterogeneous domain with respect to growth. Initial conditions (including the date and site of the introduction) and model parameters related to diffusion, reproduction and mortality are jointly estimated in the Bayesian framework by using an adaptive importance sampling algorithm. This framework is applied to the invasion of \textit{Xylella fastidiosa}, a phytopathogenic bacterium detected in South Corsica in 2015, France

Applying Evolutionary Optimisation to Robot Obstacle Avoidance

This paper presents an artificial evolutionbased method for stereo image analysis and its application to real-time obstacle detection and avoidance for a mobile robot. It uses the Parisian approach, which consists here in splitting the representation of the robot's environment into a large number of simple primitives, the "flies", which are evolved following a biologically inspired scheme and give a fast, low-cost solution to the obstacle detection problem in mobile robotics

Relire Feu la cendre de Jacques Derrida, ou, De l'interprétation comme brûlure inextinguible

L’ouvrage Feu la cendre de Jacques Derrida s’articule tout entier autour de l’analyse d’une courte phrase énigmatique : « Il y a là cendre ». Il s’agit d’une phrase écrite par Derrida lui-même, une dizaine d’années plus tôt, à la toute fin de La Dissémination. Feu la cendre peut donc être considéré comme un autocommentaire ou une autoanalyse. Toutefois, Jacques Derrida n’y dévoile pas une signification précise de sa propre sentence. Au contraire, Feu la cendre révèle l’illisibilité de la phrase, son caractère fuyant, sa puissance de signification impossible à maîtriser. Cette manière de relire « Il y a là cendre » correspond à la conception derridienne de la « dissémination » du sens. L’enjeu de ce mémoire consiste à rendre compte du texte Feu la cendre en tant que réitération de la pensée derridienne de la « dissémination » qui s’oppose à une conception herméneutique de l’interprétation prétendant pouvoir se saisir du « sens » univoque et stable d’un texte. Plus précisément, il s’agira de relever les stratégies d’écriture déployées par Derrida en vue de performer – donc de faire expérimenter – cette déroute du sens. Il y sera ainsi question de trois « mises en cendre » de la signification : d’abord, dans la forme « polylogale » du texte qui divise l’identité de l’énonciateur et son autorité sur son propre texte ; ensuite, dans le jeu d’échos entre les trois versions de Feu la cendre qui rend instable le « corps du texte » ; enfin, dans la structure « ouverte » de l’œuvre, hospitalière à de nombreux autres textes, qui en efface les limites.Jacques Derrida’s Cinders (Feu la cendre) is wholly centered on the analysis of a short, enigmatic sentence: “Cinders there are” (“Il y a là cendre”), written by Derrida himself ten years earlier at the very end of his Dissemination. Cinders can therefore be considered as a self-comment or a self-analysis, even though the author never reveals the precise meaning of his sentence. On the contrary, Cinders reveals the unreadability of “Cinders there are,” its fugitive nature, the untamed potential of its meaning. This reading corresponds to the author’s conception of “dissemination.” The aim of this master thesis is to read Cinders as a reiteration of Derrida’s thought on “dissemination,” a notion that opposes the hermeneutical conception of interpretation claiming the right to seize the univocal and stable meaning of a text. Specifically, this thesis will identify and analyze the writing strategies deployed by Derrida in order to perform, and thus experiment, this uncontrolled wandering of meaning. Three of these “incinerations” of meaning will be examined: firstly, the “polylogal” form of the text that divides the identity of the enunciator and his authority over his own writing; secondly, the play of echoes between the three different published versions of Cinders; and, lastly, the “open” structure of the book, its limitlessness that protects its hospitality to the Other

A Real-Time Robust SLAM for Large-Scale Outdoor Environments

International audienceThe problem of simultaneous localization and mapping (SLAM) is still a challenging issue in large-scale unstructured dynamic environments. In this paper, we introduce a real-time reliable SLAM solution with the capability of closing the loop using exclusive laser data. In our algorithm, a universal motion model is presented for initial pose estimation. To further refine robot pose, we propose a novel progressive refining strategy using a pyramid grid-map based on Maximum Likelihood mapping framework. We demonstrate the success of our algorithm in experimental result by building a consistent map along a 1.2 km loop trajectory (an area about 100,000 m2) in an increasingly unstructured outdoor environment, with people and other clutter in real time

A Real-Time Robust Global Localization for Autonomous Mobile Robots in Large Environments

International audienceGlobal localization aims to estimate a robot's pose in a learned map without any prior knowledge of its initial pose. Achieving highly accurate global localization remains a challenge for autonomous mobile robots especially in large-scale unstructured outdoor environments. This paper introduces a real-time reliable global localization approach with the capability of addressing the kidnapped robot problem using only laser sensors. Our approach includes four steps: 1) local Simultaneous Localization and Mapping 2) map matching 3) position tracking and 4) localization quality evaluation. For sensor perception, we use occupancy grid method to represent robot environment. A novel pyramid grid-map based coarse-to-fine matching approach is proposed to improve the localization accuracy. Experimental results including an outdoor environment of 25,000 m2 are presented to validate the feasibility and reliability of the proposed approach

Applying Evolutionary Optimisation to Robot Obstacle Avoidance

This paper presents an artificial evolutionbased method for stereo image analysis and its application to real-time obstacle detection and avoidance for a mobile robot. It uses the Parisian approach, which consists here in splitting the representation of the robot's environment into a large number of simple primitives, the "flies", which are evolved following a biologically inspired scheme and give a fast, low-cost solution to the obstacle detection problem in mobile robotics

Des pistes pour améliorer les compétences en lecture des élèves

La dernière enquête pancanadienne sur les compétences en lecture des élèves du secondaire dresse un portrait peu flatteur des élèves québécois par comparaison avec leurs pairs de l’Ontario, de l’Alberta ou de la Colombie-Britannique. Profitant de la diffusion de ces résultats accablants, la ministre de l’Éducation, du Loisir et du Sport a annoncé un certain nombre de mesures visant à rectifier le tir en matière d’enseignement de la lecture, répondant ainsi en partie à des revendications portées depuis quelque temps par les instances syndicales. Les mesures annoncées concernent la révision des orientations du programme du préscolaire et du primaire pour les premiers apprentissages, l’ajout d’une épreuve d’évaluation à la fin du deuxième cycle du primaire ainsi qu’un engagement à débloquer des fonds non négligeables pour des recherches relatives à la question de l’acquisition de la compétence en lecture

Electrophysiological and Imaging Calcium Biomarkers of Aging in Male and Female 5×FAD Mice

BACKGROUND: In animal models and tissue preparations, calcium dyshomeostasis is a biomarker of aging and Alzheimer\u27s disease that is associated with synaptic dysfunction, neuritic pruning, and dysregulated cellular processes. It is unclear, however, whether the onset of calcium dysregulation precedes, is concurrent with, or is the product of pathological cellular events (e.g., oxidation, amyloid-β production, and neuroinflammation). Further, neuronal calcium dysregulation is not always present in animal models of amyloidogenesis, questioning its reliability as a disease biomarker. OBJECTIVE: Here, we directly tested for the presence of calcium dysregulation in dorsal hippocampal neurons in male and female 5×FAD mice on a C57BL/6 genetic background using sharp electrodes coupled with Oregon-green Bapta-1 imaging. We focused on three ages that coincide with the course of amyloid deposition: 1.5, 4, and 10 months old. METHODS: Outcome variables included measures of the afterhyperpolarization, short-term synaptic plasticity, and calcium kinetics during synaptic activation. Quantitative analyses of spatial learning and memory were also conducted using the Morris water maze. Main effects of sex, age, and genotype were identified on measures of electrophysiology and calcium imaging. RESULTS: Measures of resting Oregon-green Bapta-1 fluorescence showed significant reductions in the 5×FAD group compared to controls. Deficits in spatial memory, along with increases in Aβ load, were detectable at older ages, allowing us to test for temporal associations with the onset of calcium dysregulation. CONCLUSION: Our results provide evidence that reduced, rather than elevated, neuronal calcium is identified in this 5×FAD model and suggests that this surprising result may be a novel biomarker of AD