Multi-level Contextual Type Theory

Contextual type theory distinguishes between bound variables and meta-variables to write potentially incomplete terms in the presence of binders. It has found good use as a framework for concise explanations of higher-order unification, characterize holes in proofs, and in developing a foundation for programming with higher-order abstract syntax, as embodied by the programming and reasoning environment Beluga. However, to reason about these applications, we need to introduce meta^2-variables to characterize the dependency on meta-variables and bound variables. In other words, we must go beyond a two-level system granting only bound variables and meta-variables. In this paper we generalize contextual type theory to n levels for arbitrary n, so as to obtain a formal system offering bound variables, meta-variables and so on all the way to meta^n-variables. We obtain a uniform account by collapsing all these different kinds of variables into a single notion of variabe indexed by some level k. We give a decidable bi-directional type system which characterizes beta-eta-normal forms together with a generalized substitution operation.Comment: In Proceedings LFMTP 2011, arXiv:1110.668

Hypothèse de restitution d'un navire à dolia: la construction d'une maquette

International audiencePrésentation de l'étude d'architecture navale nécessaire à la réalisation d'une maquette de l'épave du navire à dolia de Ladispoli : collecte des informations archéologiques, réalisation du plan de forme, construction du modèle d'étude au 1/10e. L'expérimentation compare les données recueillies sur d'autres épaves et a permis de proposer une hypothèse sur le chargement de la cargaison

Explicit Substitutions for Contextual Type Theory

In this paper, we present an explicit substitution calculus which distinguishes between ordinary bound variables and meta-variables. Its typing discipline is derived from contextual modal type theory. We first present a dependently typed lambda calculus with explicit substitutions for ordinary variables and explicit meta-substitutions for meta-variables. We then present a weak head normalization procedure which performs both substitutions lazily and in a single pass thereby combining substitution walks for the two different classes of variables. Finally, we describe a bidirectional type checking algorithm which uses weak head normalization and prove soundness.Comment: In Proceedings LFMTP 2010, arXiv:1009.218

Étude sur l'expérience d'un partenariat entre des intervenants des ressources communautaires œuvrant en matière pénale et des services correctionnels du Québec

L'objectif de cette étude de type exploratoire est de mieux connaître les perceptions des intervenants du réseau correctionnel québécois face au partenariat en général. Plus spécifiquement, elle vise à mieux saisir les perceptions des intervenants du réseau communautaire oeuvrant en matière pénale ainsi que des intervenants des Services correctionnels (SC) du ministère de la Sécurité publique à l'égard des éléments favorables et des contraintes du partenariat vécu particulièrement dans le milieu correctionnel québécois. Pour les fins de l'étude, la méthode de type qualitatif est privilégiée, soit l'interrogation de onze répondants provenant du réseau communautaire et des SC et intervenant auprès de personnes contrevenantes quant à leurs perceptions sur le partenariat ainsi que sur les éléments favorables et les contraintes du partenariat vécu. Les données ont été recueillies sur une période de deux mois (juin et juillet 2005), par entrevues semi-dirigées. Il ressort de la recherche qu'il existe des éléments généraux favorables au partenariat; ainsi, la transparence, le respect et la confiance à l'égard des relations entre partenaires sont rapportés comme étant favorables au partenariat. Plus spécifiquement, des éléments individuels et organisationnels ont aussi été relevés à la fois par des répondants de l'étude et dans la littérature recensée. Il s'agit respectivement de la motivation à collaborer ensemble, du respect des interventions, de l'autonomie des partenaires, de la confiance envers les intervenants, de la complémentarité, de l'entraide, du travail d'équipe, de la prise de décisions communes et des buts communs

Analysis of the erosive effect of different dietary substances and medications

Excessive consumption of acidic drinks and foods contributes to tooth erosion. The aims of the present in vitro study were twofold: (1) to assess the erosive potential of different dietary substances and medications; (2) to determine the chemical properties with an impact on the erosive potential. We selected sixty agents: soft drinks, an energy drink, sports drinks, alcoholic drinks, juice, fruit, mineral water, yogurt, tea, coffee, salad dressing and medications. The erosive potential of the tested agents was quantified as the changes in surface hardness (ΔSH) of enamel specimens within the first 2 min (ΔSH2-0 = SH2 min - SHbaseline) and the second 2 min exposure (ΔSH4-2 = SH4 min - SH2 min). To characterise these agents, various chemical properties, e.g. pH, concentrations of Ca, Pi and F, titratable acidity to pH 7·0 and buffering capacity at the original pH value (β), as well as degree of saturation (pK - pI) with respect to hydroxyapatite (HAP) and fluorapatite (FAP), were determined. Erosive challenge caused a statistically significant reduction in SH for all agents except for coffee, some medications and alcoholic drinks, and non-flavoured mineral waters, teas and yogurts (P < 0·01). By multiple linear regression analysis, 52 % of the variation in ΔSH after 2 min and 61 % after 4 min immersion were explained by pH, β and concentrations of F and Ca (P < 0·05). pH was the variable with the highest impact in multiple regression and bivariate correlation analyses. Furthermore, a high bivariate correlation was also obtained between (pK - pI)HAP, (pK - pI)FAP and ΔSH

Analysis of the erosive effect of different dietary substances and medications

Excessive consumption of acidic drinks and foods contributes to tooth erosion. The aims of the present in vitro study were twofold: (1) to assess the erosive potential of different dietary substances and medications; (2) to determine the chemical properties with an impact on the erosive potential. We selected sixty agents: soft drinks, an energy drink, sports drinks, alcoholic drinks, juice, fruit, mineral water, yogurt, tea, coffee, salad dressing and medications. The erosive potential of the tested agents was quantified as the changes in surface hardness (ΔSH) of enamel specimens within the first 2min (ΔSH2-0=SH2min−SHbaseline) and the second 2min exposure (ΔSH4-2=SH4min−SH2min). To characterise these agents, various chemical properties, e.g. pH, concentrations of Ca, Pi and F, titratable acidity to pH 7·0 and buffering capacity at the original pH value (β), as well as degree of saturation (pK−pI) with respect to hydroxyapatite (HAP) and fluorapatite (FAP), were determined. Erosive challenge caused a statistically significant reduction in SH for all agents except for coffee, some medications and alcoholic drinks, and non-flavoured mineral waters, teas and yogurts (P<0·01). By multiple linear regression analysis, 52% of the variation in ΔSH after 2min and 61% after 4min immersion were explained by pH, β and concentrations of F and Ca (P<0·05). pH was the variable with the highest impact in multiple regression and bivariate correlation analyses. Furthermore, a high bivariate correlation was also obtained between (pK−pI)HAP, (pK−pI)FAP and ΔS

Classification and automatic indexing in a persistent object environment

The goal of this project is to study classification and automatic indexing for multimedia data in the context of digital libraries. The general objectives are: (1) to propose methods for digital media classification and indexing and (2) to implement them effectively by using a persistent environment provided by object-oriented database systems

Une expérience d'annotation à large échelle : le projet OTIM

Nous proposons dans cette présentation de faire le point sur une opération dannotation de grande envergure conduite dans le cadre du projet OTIM. Nous avons dans le cadre de ce projet constitué un grand corpus audio-visuel de parole spontanée comprenant 8 heures de dialogues (soit 102.457 mots correspondant à 6.611 formes différentes) totalement transcrit, aligné et richement annoté pour lensemble des domaines et des modalités. Nous avons donc été confrontés aux principaux problèmes posés par lannotation de ce type de ressource. Cette présentation décrit les recommandations et les techniques que nous avons utilisées pour parvenir à nos fins

Resection and resolution of bone marrow lesions associated with an improvement of pain after total knee replacement: a novel case study using a 3-Tesla metal artefact reduction MRI sequence

We present our case report using a novel metal artefact reduction magnetic resonance imaging (MRI) sequence to observe resolution of subchondral bone marrow lesions (BMLs), which are strongly associated with pain, in a patient after total knee replacement surgery. Large BMLs were seen preoperatively on the 3-Tesla MRI scans in a patient with severe end stage OA awaiting total knee replacement surgery. Twelve months after surgery, using a novel metal artefact reduction MRI sequence, we were able to visualize the bone-prosthesis interface and found complete resection and resolution of these BMLs. This is the first reported study in the UK to use this metal artefact reduction MRI sequence at 3-Tesla showing that resection and resolution of BMLs in this patient were associated with an improvement of pain and function after total knee replacement surgery. In this case it was associated with a clinically significant improvement of pain and function after surgery. Failure to eradicate these lesions may be a cause of persistent postoperative pain that is seen in up to 20% of patients following TKR surgery

La contrefaçon des produits de santé dans le monde (moyens de lutte et implication du pharmacien d officine)

La contrefaçon des produits de santé est un véritable problème de santé publique mondial en pleine croissance. Les médicaments contrefaits représenteraient 10% du commerce mondial de médicaments, soit 75 milliards de dollars chaque année. Dans certaines zones d Afrique, d Asie ou d Amérique du Sud, plus de 30% des médicaments vendus sont falsifiés. Et, ces contrefaçons sont responsables de dizaines de milliers de morts chaque année dans le monde. Les pays développés quant à eux, sont généralement épargnés par ce fléau, grâce à leurs réseaux de distribution plus sécurisés. Pour contourner ces réseaux, les contrefacteurs utilisent alors internet : 62% des médicaments qui y sont vendus sont contrefaits. Depuis une dizaine d années, de nombreux acteurs de la lutte anti-contrefaçon travaillent ensemble à l échelle nationale comme internationale. La lutte passe par l organisation d actions coup de poing , de campagnes de sensibilisation, le développement de technologies anti-contrefaçon, le renforcement des sanctions prévues pour les contrefacteurs. De par sa proximité avec les patients, le pharmacien d officine joue un rôle important de sensibilisation. Il se doit d informer ses patients sur les dangers des achats de médicaments sur internet, et devra les conseiller en cas de séjour dans des pays touchés par la contrefaçon. Le pharmacien doit également savoir repérer d éventuelles contrefaçons dans l exercice de son travail.Health products counterfeit is a major worldwide public health concern, actively growing. Counterfeit medicines represent about 10% of drugs international trade, amounting 75 billion dollars annually. This black market is increasing strongly. In some areas of Africa, Asia and South America, over 30% of sales are fakes. And these are responsible for tens of thousands of deaths worldwide each year. For their part, developed countries are usually spared by this scourge, their distribution networks being more secured. To get around these networks, counterfeiters use internet : 62% of medicines sold online are counterfeit. Over the past ten years, counterfeit fighting actors have collaborated nationally and internationally. This fight requires lightening raids, awareness campaigns, development of anti-counterfeit technologies, and strengthening of sanctions against counterfeiters. Being close to patients, the pharmacist plays an important educating role. He must inform them of the risk of buying medicines online, and advise them if they plan to travel to countries affected by counterfeiting. Finally, the pharmacist must be able to detect potential counterfeits, in the course of his work.ANGERS-BU Médecine-Pharmacie (490072105) / SudocSudocFranceF