Constraints on nuclear matter properties from QCD susceptibilities

We establish the interrelation between the QCD scalar response of the nuclear medium and its response to a scalar probe coupled to nucleons, such as the scalar meson responsible for the nuclear binding. The relation that we derive applies at the nucleonic as well as at the nuclear levels. Non trivial consequences follow. In particular it opens the possibility of relating medium effects in the scalar meson exchange or three-body forces of nuclear physics to QCD lattice studies of the nucleon massComment: Submitted to EPJ

Progress in Understanding the Nuclear Equation of State at the Quark Level

At the present time there is a lively debate within the nuclear community concerning the relevance of quark degrees of freedom in understanding nuclear structure. We outline the key issues and review the impressive progress made recently within the framework of the quark-meson coupling model. In particular, we explain in quite general terms how the modification of the internal structure of hadrons in-medium leads naturally to three- and four-body forces, or equivalently, to density dependent effective interactions.Comment: Invited presentation at XXX Symposium on Nuclear Physics, Hacienda Cocoyoc, Jan. 3-6, 200

Hypernuclei in the quark-meson coupling model

We present results of hypernuclei calculated in the latest quark-meson coupling (QMC) model, where the effect of the mean scalar field in-medium on the one-gluon exchange hyperfine interaction, is also included self-consistently. The extra repulsion associated with this increased hyperfine interaction in-medium completely changes the predictions for {\Sigma} hypernuclei. Whereas in the earlier version of QMC they were bound by an amount similar to {\Lambda} hypernuclei, they are unbound in the latest version of QMC, in qualitative agreement with the experimental absence of such states.Comment: 6 pages, 3 figures, to be published in the proceedings of Achievements and New Directions in Subatomic Physics: Workshop in Honour of Tony Thomas' 60th Birthday, Adelaide, South Australia, 15-19 Feb 201

Fermi matrix element with isospin breaking

Prompted by the level of accuracy now being achieved in tests of the unitarity of the CKM matrix, we consider the possible modification of the Fermi matrix element for the $\beta$-decay of a neutron, including possible in-medium and isospin violating corrections. While the nuclear modifications lead to very small corrections once the Behrends-Sirlin-Ademollo-Gatto theorem is respected, the effect of the $u-d$ mass difference on the conclusion concerning $V_{ud}$ is no longer insignificant. Indeed, we suggest that the correction to the value of $|V_{ud}|^2 \, + \, |V_{us}|^2 \, + \, |V_{ub}|^2$ is at the level of $10^{-4}$

Quark structure and nuclear effective forces

We formulate the quark meson coupling model as a many-body effective Hamiltonian. This leads naturally to the appearance of many-body forces. We investigate the zero range limit of the model and compare its Hartree-Fock Hamiltonian to that corresponding to the Skyrme effective force. By fixing the three parameters of the model to reproduce the binding and symmetry energy of nuclear matter, we find that it allows a very satisfactory interpretation of the Skyrme force.Comment: 4 pages, 1tabl

EMC and Polarized EMC Effects in Nuclei

We determine nuclear structure functions and quark distributions for $^7$Li, $^{11}$B, $^{15}$N and $^{27}$Al. For the nucleon bound state we solve the covariant quark-diquark equations in a confining Nambu--Jona-Lasinio model, which yields excellent results for the free nucleon structure functions. The nucleus is described using a relativistic shell model, including mean scalar and vector fields that couple to the quarks in the nucleon. The nuclear structure functions are then obtained as a convolution of the structure function of the bound nucleon with the light-cone nucleon distributions. We find that we are readily able to reproduce the EMC effect in finite nuclei and confirm earlier nuclear matter studies that found a large polarized EMC effect.Comment: 8 pages, 9 figure

Training future language teachers to develop online tutors' competence through reflective analysis

International audienceThis article sets out to identify key competencies which language tutors need to develop in order to manage synchronous online teaching. In order to aptly monitor interactions with distant learners, it is proposed that three types of regulation pertaining to socio-affective, pedagogical and multimedia aspects are required. On the one hand, this research aims at specifying these competencies and, on the other hand, it seeks to identify the relevance of reflective analysis for professional development. The context of this study is a teacher training programme for Masters Degree students in teaching French as a foreign language that provides trainees with the opportunity of teaching online to intermediate-level students of French from a North American university via a desktop videoconferencing platform. This programme first endeavours to put trainees in a professional situation by getting them to prepare and administer sessions in order to confront them with the specific challenges of synchronous online tutoring. Second, it seeks to help them to gain insight into their own activity by developing critical thinking towards their own practice. The data elicited for this research derive from the tutor trainees' interpretations of their own practice when confronted with the film of their own situated activity. The episodes chosen by the trainees to feed the self-confrontation process constitute significant units because by being told and commented upon, they elucidate how and to what extent competencies are built. Three discursive strategies have been identified and used to organise the content analysis of the data: description; expression of a difficulty; reflective review of the activity. The strategies used by trainees to verbalise their own activity can inform teacher educators about the constraints of the work situation and about the resources trainees need to deploy to face up to this unknown professional situation. Results indicate that trainees concentrate particularly on pedagogical aspects that distance and faulty technology have rendered complex. The encountered difficulties are equally distributed between a repertoire of competencies pertaining to language teaching and competencies more directly linked with online teaching. Finally, this study has enabled us to assess the potential of self-confrontation for teacher practice and leads us to propose directions for improving this training device

Recherche-développement et didactique des langues

National audienceThis article aims at analysing the potential of contextualised research-development for research in applied linguistics. Starting from the meaning this methodology has for the industrial sector in which it originated, our purpose will be firstly to propose a definition for contextualised research-development, and secondly to describe its particular mode of production of knowledge so as to highlight its key elements and its limits for research on foreign language learning through multimedia.Cet article vise à analyser le potentiel de la recherche-développement pour la recherche en didactique des langues. En partant de son acception pour le secteur industriel dont cette démarche est issue, il s'agira de définir ce que pourrait être une recherche-développement contextualisée, de décrire son mode particulier de production des connaissances afin d'en souligner les éléments essentiels et les limites pour la recherche sur l'apprentissage médiatisé des langues étrangères

Le journal de conception : un outil de construction de la compétence professionnelle

International audienceLa présente recherche s'appuie sur un corpus composé de journaux de conception tenus par des étudiants inscrits dans une formation universitaire professionnalisante (master 2 "didactique des langues et TICE") alors qu'ils réalisent un projet de conception multimédia. Le journal de conception est un outil proposé à ces futurs enseignants pour accompagner le processus de professionnalisation, et particulièrement les aspects technologiques. Cet article postule en effet que la compétence professionnelle se construit dans l'action et par le biais de la réflexivité. Une analyse de contenu menée sur un échantillon de journaux de conception contribue à appréhender de quelles façons les formés mobilisent des ressources diverses, se confrontent à leurs propres émotions et à des logiques différentes, et se créent une mémoire de l'action propice à rendre effectives les compétences développées lors de la formation

Évaluation du potentiel d'apprentissage d'une tâche médiatisée

National audienceWhen it comes within the framework of Research and Development (R&D), the design of computer-mediated tasks for language learning should be supported by existing theoretical knowledge, especially coming from the field of psycholinguistics. The design process enables the researcher to test a hypothesis and give it substance through a pedagogic scenario. Yet the research and development cycle is only complete when the learning potential is assessed against the initial hypotheses. This last step is essential to verify both the validity of the theoretical framework and the appropriateness of the pedagogic tool for the learners' needs. This article illustrates the three-stage process – theoretical choices, design and assessment. Its main objective is to demonstrate how Swain's “Comprehensible Output” theory underpins the pedagogic scenario of Virtual Cabinet – a site designed to develop listening comprehension – and provides relevant criteria for its evaluation.Quand elle s'inscrit dans le modèle de la recherche-développement, la conception de tâches médiatisées pour l'apprentissage de l'anglais gagne à être étayée par des connaissances théoriques existantes émanant, en particulier, de la psycholinguistique. La conception fournit l'occasion de tester une hypothèse et de lui donner corps dans un scénario pédagogique. Toutefois, le cycle de la recherche-développement n'est complet que lorsque le potentiel d'apprentissage est évalué par rapport aux hypothèses initiales. Cette dernière étape est déterminante pour vérifier, d'une part, la validité du cadre théorique et, d'autre part, l'adéquation de la proposition pédagogique aux besoins des apprenants. Ce processus en trois temps (choix théoriques, conception et évaluation) est illustré dans cet article qui vise à montrer comment une théorie psycholinguistique, celle de l'output compréhensible émise par Swain, a nourri l'écriture du scénario pédagogique de Virtual Cabinet, un site d'apprentissage pour développer la compréhension de l'anglais oral, et a fourni les critères pour son évaluation