\'Evaluation entre pairs en math\'ematiques: activit\'e d'\'etudiant∙\bulletes lors d'\'evaluations de preuves

This article deals with peer-assessment in the context of higher education teaching in mathematics, and examines the nature of student activity when assessing work produced by peers. After an overview of research on peer assessment, we propose an experiment with students in a specific post-secondary scientific class, and analyze the activity of the students involved. Our analyses are based on a priori analyses of the proposed tasks and tools from research on students personal mathematical work. We base on written notes of assessments, observations of pairs in assessment situations, and answers to a questionnaire on the perception of their activity. We have identified some specific student activities during the peer assessment process, in particular related to the analysis and correction of proofs, but also to the awareness of the issues associated with evaluation. This enables us to argue for the potential of peer assessment in higher mathematics education.Comment: in French languag

Sur une expérience d'enseignement à distance des Ecoles des Mines: illustration par la formation en résistance des matériaux

Dans cette communication on présente un retour d’expérience de la Formation Continue Diplômante d’ingénieur organisée par le Groupe des Ecoles des Mines. On fait le point sur le retour d’expérience de sept années de formation et d’environ 70 ingénieurs formés. On part de la problématique d’évolution de la formation continue diplômante face à l’évolution des effectifs et des offres de financements. Les outils numériques et d’enseignement à distance via internet ont été utilisés pour répondre à ce problème. Après une description globale de la démarche retenue et du pilotage pédagogique de cette formation, on s’appuiera sur l’exemple de l’enseignement de la résistance des matériaux pour illustrer notre propos. Un point spécifique sera fait sur les commodités de ce type d’enseignement à distance pour les ressortissants des pays du sud de la méditerranée et de l’Afrique en général

Pre-formulation and systematic evaluation of amino acid assisted permeability of insulin across in vitro buccal cell layers

The aim of this work was to investigate alternative safe and effective permeation enhancers for buccal peptide delivery. Basic amino acids improved insulin solubility in water while 200 and 400 µg/mL lysine significantly increased insulin solubility in HBSS. Permeability data showed a significant improvement in insulin permeation especially for 10 µg/mL of lysine (p < 0.05) and 10 µg/mL histidine (p < 0.001), 100 µg/mL of glutamic acid (p < 0.05) and 200 µg/mL of glutamic acid and aspartic acid (p < 0.001) without affecting cell integrity; in contrast to sodium deoxycholate which enhanced insulin permeability but was toxic to the cells. It was hypothesized that both amino acids and insulin were ionised at buccal cavity pH and able to form stable ion pairs which penetrated the cells as one entity; while possibly triggering amino acid nutrient transporters on cell surfaces. Evidence of these transport mechanisms was seen with reduction of insulin transport at suboptimal temperatures as well as with basal-to-apical vectoral transport, and confocal imaging of transcellular insulin transport. These results obtained for insulin is the first indication of a possible amino acid mediated transport of insulin via formation of insulin-amino acid neutral complexes by the ion pairing mechanism

Traitement séquentiel par lamivudine puis interféron de l'hépatite B chronique (une étude rétrospective)

PARIS5-BU Méd.Cochin (751142101) / SudocPARIS-BIUM (751062103) / SudocCentre Technique Livre Ens. Sup. (774682301) / SudocSudocFranceF

Mettre à portée d'apprentis les méthodes de résolution par éléments finis : alignement pédagogique, évaluation par les pairs, classe inversée et analyse d'enseignement

National audienc

Synthesis and characterization of an acylated di-peptide (Myr-Trp-Leu) with modified transmucosal transport properties

In order to improve the buccal absorption of a dipeptide model compound, Tryptophan-Leucine (Trp-Leu), we have synthesised a lipophilic derivative by myristoylation of the N- terminal amino group of Trp-Leu. The acylated peptide (Myr-Trp-Leu) was characterized by HPTLC, purified and isolated by chromatography on a silica gel column. Its structure was confirmed by (13)C and (1)H NMR and mass spectroscopy. The increased lipophilicity of the Myr-Trp-Leu was compared to that of the native peptide by chromatography and by its partition coefficient between n-octanol and saline phosphate buffer. In addition, the sensitivity towards hydrolytic enzymes was studied. The interaction of Trp-Leu with liposomes as model membranes was also studied. The phase transition temperature of dipalmitoylphosphatidylcholine (DPPC) was lowered in the presence of Myr-Trp-Leu, while it was increased in the presence of native parent peptide. Permeation experiments performed in vitro with pig buccal mucosa showed that the Myr-Trp-Leu accumulated in the tissue at the various concentrations tested. In contrast, the native peptide was able to pass through the membrane at all concentrations used. Lipophilic modification of the peptide by acylation drastically changes its behaviour towards tissue systems

Mettre à portée d'apprentis les méthodes de résolution par éléments finis : alignement pédagogique, évaluation par les pairs, classe inversée et analyse d'enseignement

National audienc

Morphological, Packing, Flow and Tableting Properties of New Avicel Types

The six Avicel products designed for compression - the classical grades PH-105, PH-103, PH-101 and PH-102, and the new Avicels PH-112 and PH-200 - have been submitted to a comparative investigation for both their basic and tableting properties. According to the manufacturer all these products differ by their nominal particle size and moisture content. Basic properties of the powders were first determined, namely moisture content (loss on drying and Karl Fischer titration), particle size and shape (sieving and image analysis), densities (true bulk and tap densities, Hausner ratio) and flow properties (vibratory hopper technique). As tableting properties, the compactibility of the powders and the effect of adding a hydrophobic lubricant (0.5% magnesium stearate) on the compact strength were evaluated by preparing compacts at a given applied pressure using a hydraulic press. Weight and dimensional variations were assessed by preparing tablets at a target crushing strength of 70 Newtons on a high speed machine. The comparison of the conventional Avicel PH grades showed that Avicel PH-105 differed markedly in its properties (high compressibility on tapping, high compactibility, inacceptable tablet weight variability and very poor disintegrating properties) from the other grades. As to the two new Avicel PH grades, conflicting results with the literature were obtained with the low-moisture product Avicel PH-112. We observed, like other authors but in contrast to manufacturer's data, values of compactibility and strength reduction ratio upon lubrication as well as of the coefficient of tablet weight variation similar to those of the standard Avicel PH-102, of comparable particle size. This can be certainly explained by an uptake of moisture of the Avicel PH-112 powder as proved experimentally. This would limit the use of this material to an air-conditioned room. The large particle size product Avicel PH-200 displayed a compactibility close to that of all the other Avicel PH grades (except PH-105), but the highest susceptibility to magnesium stearate. As expected, because it is free-flowing, Avicel PH-200 gave the lowest tablet weight variability. Additionnally, the two new grades showed disintegrating properties similar to those of Avicel PH-103, PH-102 and PH-101. Finally, one should bear in mind that the small differences reported here may not be significant because of substantial inter batch variability