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Inégalités d’éducation et ségrégation sociale en France et en Hauts-de-France : état des lieux et recommandations
No full textInternational audienc
Un algorithme simple pour la jointure dans le pire cas et l'échantillonnage uniforme
No full textInternational audienceWe present an elementary branch and bound algorithm with a simple analysis of why it achieves worstcase optimality for join queries on classes of databases defined respectively by cardinality or acyclic degree constraints. We then show that if one is given a reasonable way for recursively estimating upper bounds on the number of answers of the join queries, our algorithm can be turned into algorithm for uniformly sampling answers with expected running time Õ(UP/OUT) where UP is the upper bound, OUT is the actual number of answers and Õ(•) ignores polylogarithmic factors. Our approach recovers recent results on worstcase optimal join algorithm and sampling in a modular, clean and elementary way
Le geste sur les scènes des XXe et XXIe siècles
No full textInternational audienceAs an object of study, the theatrical gesture remains elusive and ambiguous: it can support or contradict speech, it can transpose a movement of the soul or be devoid of any psychological reference. It is the most ephemeral component of the actor’s performance, carrying with it a tradition it can refer to. It is also a repository: each spectator, from the outside, invests it with their own imagination and culture, because the gesture is a sign that can be decoded collectively and codified individually. This volume proposes a study of gesture and its plasticity, focusing on the dialogue between invention and tradition on European stages. Focusing primarily on stage practice, the authors question the poetic and aesthetic function of gesture in both current productions of ancient texts and contemporary creations. Overall, this volume reflects a desire to open up research on gesture to a field of exploration that is constantly in resonance with the temporal dimension: from memories embodied in a gesture to the teaching of some acting techniques; from the aesthetic potential of the eternal presentification of gesture to the temporality specific to the relationship between the text and its staging.En tant qu’objet d’étude, le geste théâtral demeure insaisissable et ambigu : il peut soutenir ou contredire la parole, il peut transposer un mouvement de l’âme ou être libéré de tout référentiel psychologique. Il est la composante la plus éphémère de la performance du comédien, qui charrie en lui une tradition gestuelle à laquelle il peut faire référence. Il est aussi un lieu de dépôt: chaque spectateur, de l’extérieur, l’investit de son propre imaginaire et de sa propre culture, car le geste est un signe que l’on peut à la fois décoder collectivement et encoder individuellement. Ce volume propose une étude du geste et de sa plasticité en s’intéressant au dialogue entre invention et tradition sur les scènes européennes. S’orientant principalement vers la pratique scénique, les auteurs de cet ouvrage interrogent la fonction poétique et esthétique du geste aussi bien dans la mise en scène actuelle de textes anciens que dans les créations contemporaines. L’ensemble témoigne d’une volonté d’ouvrir la recherche sur le geste à un champ d’exploration en constante résonance avec la dimension temporelle: des mémoires incarnées dans l’acte gestuel à la transmission pédagogique d’une certaine pratique; du potentiel esthétique de l’éternelle présentification du geste à la temporalité qui est propre à la relation entre le texte et sa mise en scène
The Unexpected Role of Fluorine in the Band Gap Narrowing of Silver Niobium and Tantalum Pyrochlore Oxyfluorides
No full textInternational audienceMixed anion compounds have attracted growing interest in solid-state chemistry as a way to tailor physical properties. In this work, we synthesized new silver niobium and tantalum pyrochlore oxyfluorides by an ion-exchange reaction from Na2M2O5F2 (M = Nb or Ta). Instead of a classical Na+/Ag+ cation exchange, a less conventional dual cation and anion exchange reaction (2 Na+ + F–)/(Ag+ + H2O) takes place. Indeed, chemical and thermal analyses, as well as Rietveld refinement and 19F NMR, reveal the formation of AgTa2O5F·H2O and Na0.4Ag0.8Nb2O5F1.2·0.8H2O leading to a significant band gap narrowing of approximately 0.4 eV, as determined by diffuse reflectance spectroscopy. DFT calculations show that Ag 4d–O 2p states are located at the edge of the valence band and that the presence of fluorine in the coordination sphere of Ag promotes the hybridization and hence contributes to the band gap narrowing
Enriching organisational design for games: the case of badminton in physical education
No full textInternational audiencePurpose:Providing students with enjoyable experiences in Physical Education (PE) is considered a key variable in research on increasing Physical Activity (PA) levels. Designing game formats in PE is relevant to achieving this aim. Coupling principles of Motor Praxeology (MP) and the Constraints Led Approach (CLA) to design three games, the aim of this study was to examine how participants’ sex, age and skill levels (organismic constraints) interacted with varied manipulations of task and environmental constraints in the organisational design of badminton games to increase their enjoyment and PA.Method:Participants were students (n = 55, Mage = 14.0, SD = 2.41, 41.8% girls, aged 11–19) enrolled in a PE unit with three distinct badminton organisational designs for games: Individual Tournament (IT), Team Score (TS) and Personal Challenge (PC). IT challenges students in a group of a homogeneous skill level with a one-on-one competition. TS consists of a series of one-on-one games amongst a group of students with a heterogeneous skill level. PC is a competition between students in a heterogenous-level group, adopting a handicap score system. Enjoyment and level of PA was measured using a pleasure scale and accelerometers.Results:Results indicated little effect of organisational design on pupils’ enjoyment but showed a difference in their PA: younger and skilled boys moved less in the PC design compared to the TS organisational design.Discussion/conclusion:Our results suggest that potential interactions between the format of the organisational design and individual differences in students could be relevant for increasing PA in PE programmes. In exploring the effects of interactions of organisational designs for games, goal tasks and students’ characteristics, a combination of MP and CLA frameworks helps to address some of the prevailing beliefs about pleasure and the commitment made by students in common physical education play and activity formats. Our study showed that there is no ideal organisational design for engaging students, but that the most fruitful formats depend on the specific interests of the students.Practical implications:These theoretical frameworks invite PE teachers to develop organisational designs by providing interaction between goal-oriented tasks and social variables (e.g. relationships between players) to provoke richer experiences in all students from different skill levels
Création divine et naturalisation de l’ordre social aux XIIIe-XVe siècles : l’exégèse visuelle et textuelle de la Genèse dans les Bibles moralisées
No full textInternational audience"Ce que Dex garnist la mer de diverses manieres de poissons senefie Iesu Crist qi garni le munde de diverses manieres de genz": this is how the French Bible moralization produced for King Philippe Auguste, circa 1220-1223 (Vienne, Österreische Nationalbibliothek, Codex Vidobonensis 2554, fol. 1v), interprets one of the episodes from Creation (Gn 1:21). The textual exegesis is complemented by a visual exegesis in the form of an illuminated medallion showing the world, represented in the manner of a mappa mundi, populated by four individuals, each representing a human category: a knight, a butcher, a money-changer and a schoolmaster. This example perfectly illustrates one of the claims of moralized Bibles: to distinguish, name and represent the different components of medieval society, to found a social taxonomy using the historical biblical matrix. In this scholarly exegesis, intended exclusively for princes, the Book of Genesis gives rise to a homology between divine creation and a naturalized social order: each category of nature (water, sky), animal (fish, mares, birds, reptiles) or vegetable (fruit trees) corresponds to a category of man. This paper will examine the way in which theologians, through these various moralized Bibles - from those of the first quarter of the 13th century, preserved in Vienna, to the Bible of John the Fearless, dating from the early years of the 15th century - provided sovereign and princely powers with an exegesis of the Book of Genesis that founded an ordered and naturalized vision of a dominated social order.« Ce que Dex garnist la mer de diverses manieres de poissons senefie Iesu Crist qi garni le munde de diverses manieres de genz » : c’est ainsi que la moralisation de la Bible française réalisée pour le roi Philippe Auguste, vers 1220-1223 (Vienne, Österreische Nationalbibliothek, Codex Vidobonensis 2554, fol. 1v), interprète l’un des épisodes de la Création (Gn 1,21). À l’exégèse textuelle s’ajoute une exégèse visuelle en un médaillon enluminé qui montre le monde, représenté à la manière d’une mappa mundi, peuplé de quatre individus représentant chacun une catégorie humaine : un chevalier, un boucher, un changeur et un maître d’école. Cet exemple illustre parfaitement ce que fut l’une des prétentions des Bibles moralisées : distinguer, nommer et représenter les différentes composantes de la société médiévale, fonder une taxinomie sociale en usant de la matrice historique biblique. Dans cette exégèse savante exclusivement destinée aux princes, le livre de la Genèse donne lieu à l’exposition d’une homologie entre la Création divine et celle d’un ordre social naturalisé : à chaque catégorie de la nature (eau, ciel), d’animaux (poissons, juments, oiseaux, reptiles) ou de végétaux (arbres fruitiers) correspond une catégorie d’hommes. Il sera donc question, dans cette communication, d’examiner la façon dont les théologiens, par le biais de ces différentes Bibles moralisées – depuis celles du premier quart du XIIIe siècle, conservées à Vienne, jusqu’à la Bible dite « de Jean sans Peur », datant des premières années du XVe siècle –, ont livré aux pouvoirs souverains et princiers une exégèse du livre de la Genèse fondant une vision ordonnancée et naturalisée d’un ordre social dominé
Fighting for resources: a unified growth model of the Great Divergence
No full textInternational audienceThis paper interprets the Great Divergence as the cumulative influence of small asymmetries in technology or various initial conditions, amplified through conflict over resources. It introduces a tractable framework that integrates demography, technological progress, and conflict into a unified growth model. The amplification effect of resource appropriation is characterized by conflict multipliers in both the short- and long-run. Conflict is a source of substantial divergence, as the appropriation of resources allows some countries to develop faster at the expense of others. Reconvergence is, however, possible through population growth, due to strategic complementarities in fertility decisions and staggered demographic transitions. Rich and non-linear dynamics display key features of comparative economic development between the West and the Global South, but also shed light on a variety of historical case studies that share such dynamics of divergence and reconvergence, as well as more dramatic episodes of population extinction in a dominated country. Our framework can easily be extended to study the role of resource exhaustion or the fundamental trade-off between trade and conflict
An exploratory analysis of learning from peers: Radial vs. nonradial efficiency measures and convex vs. nonconvex technologies
No full textInternational audienceThis work investigates to which extent the known substantial differences between technical efficiencies on convex and nonconvex technologies translate into different learning possibilities. We also study whether radial and nonradial efficiency measures lead to a different learning experience. To our knowledge, these questions have never been investigated. Our empirical research is guided by three working hypotheses regarding how the analysis of peers facilitates learning by comparing on the one hand convex versus nonconvex technologies, and on the other hand radial versus nonradial efficiency measures. These working hypotheses are investigated using three distinct metrics: peer count, peer similarity, and peer dominance. We employ five existing secondary data sets and one large sample of more than 10,000 observations on Belgian traffic control centres in an effort to refute our three working hypotheses using these three metrics. Anticipating our conclusion, the combination of the logical, the statistical, and the managerial arguments against convexity is rather overwhelming in our data and we think that convexity is an axiom that should be scrutinized in all these three respects in all future methodological innovations as well as in empirical applications
Isabelle-Rachel Casta, « Florence Boulerie et Cristina Panzera, Sages lecteurs et/ou galopins farceurs », Strenæ [En ligne], 26 | 2025, mis en ligne le 31 août 2025, consulté le 16 novembre 2025. URL : http://journals.openedition.org/strenae/11660 ; DOI : https://doi.org/10.4000/155azhttps://journals.openedition.org/strenae/11660: Recension
No full textInternational audienceIl s'agit du compte-rendu d'un ouvrage collecti
