Landau-Ginzburg method applied to finite fermion systems: Pairing in Nuclei

Given the spectrum of a Hamiltonian, a methodology is developed which employs the Landau-Ginsburg method for characterizing phase transitions in infinite systems to identify phase transition remnants in finite fermion systems. As a first application of our appproach we discuss pairing in finite nuclei.Comment: 14 pages, 4 figure

Les fondements microéconomiques de la persistance de l'innovation. Une analyse économétrique

The microeconomic foundations of innovation persistence: an econometric analysis This study examines the persistence of innovation in French manufacturing firms over the period 1986-1996. We find that innovation is strongly persistent at the firm level and that the nature of this persistence depends on the size of the firm. While learning-by-doing may explain innovation persistence in the small firms, the large firms exhibit a sequential model of formal research investment where learning-by-doing is not significant.Cette étude examine la persistance des comportements d'innovation des entreprises industrielles françaises entre 1986 et 1996. Nous trouvons que l'innovation est fortement persistante et que la nature de cette persistance dépend de la taille de l'entreprise. Alors que le modèle d'apprentissage est pertinent pour les petites entreprises, les grandes entreprises font reposer leurs innovations sur un modèle séquentiel d'investissement en recherche où l'apprentissage n'est pas significatif.Duget Emmanuel, Monjon Stéphanie. Les fondements microéconomiques de la persistance de l'innovation. Une analyse économétrique. In: Revue économique, volume 53, n°3, 2002. pp. 625-636

Le biais technologique : une analyse économétrique sur données individuelles.

Skill bias: an econometric analysis at the firm level Over the last 20 years the structure of firms' employment has moved towards more skilled personnel while unskilled workers have faced a high and persistent unemployment. The purpose of this paper is to test the hypothesis of a skill-biased technical progress. We introduce three new features. First, we estimate our model at the firm level. Second, we distinguish 5 innovation types, that allow fora decomposition of the skill bias. Last, firm level innovation is endogenous.Le biais technologique. Une analyse économétrique sur données individuelles Sur les vingt dernières années, la structure de la main-d'œuvre des entrepri­ses s'est déformée au profit des personnels les plus qualifiés, alors que la main-d'œuvre non qualifiée a dû faire face à un chômage élevé et persistant. L'objectif de cette étude est de tester l'hypothèse d'un progrès technique biaisé en faveur de la main-d'œuvre qualifiée. Elle présente trois originalités. Premièrement, les estimations sont réalisées au niveau de l'entreprise. Deuxièmement, nous mesu­rons le progrès technique par cinq types d'innovation différents qui permettent de décomposer le biais technologique. Troisièmement, l'innovation est endogène.Greenan Nathalie, Duget Emmanuel. Le biais technologique : une analyse économétrique sur données individuelles. In: Revue économique, volume 48, n°5, 1997. pp. 1061-1089

Hexapodes de positionnement de précision

L’hexapode est un robot parallèle permettant la mise en position d’objets suivant les six degrés de liberté (trois translations Tx, Ty, Tz et trois rotations Rx, Ry, Rz). Au milieu du xxe siècle, les premiers hexapodes ont servi à tester des pneus ou comme simulateurs de vol. Dans les années 1990, grâce à l’évolution des composants électroniques et à l’augmentation des capacités de calcul, l’arrivée de contrôleurs abordables et performants a permis leur essor. Nous verrons dans cet article comment un hexapode est constitué et étudierons les critères de sélection les plus pertinents avant de décrire quelques exemples d’applications

L-Asparaginase Loaded into Erythrocytes (GRASPA): Principle and Interests in Acute Lymphoblastic Leukemia.

Abstract L-asparaginase is an essential drug in the treatment of acute lymphoblastic leukemia (ALL) in cleaving plasmatic asparagine, an aminoacid involved in lymphoblastic cell proliferation. However, the short half-life (24h) of the native L-asparaginase requests massive and repeated injections (5000 to 10000 IU/m2) leading to potential adverse events. Reactions of hypersensitivity and/or anti-asparaginase neutralizing antibodies are often observed. The encapsulation of L-asparaginase into erythrocytes is an interestic way to improve the therapeutic index and decreasing side effects. The technique of encapsulation is carried out by reversible osmotic lysis: qualified red blood cells (RBCs) are subjected to hypo-osmotic conditions by dialysis followed by one return to the isotonicity. During dialysis, the RBCs inflate and pores are formed on the membrane. L-asparaginase penetrates by these pores into the erythrocytes. Back to isotonicity, RBCs recover their original shape and size, the pores are then definitively closed, and L-asparaginase is definitively encapsulated. An automated device allows achievement of an accurate reproducibility of the technique of entrapment which is assessed by the quality of the red cells and quantity of drug entrapped. In addition, the technology employed allows a 2-hour preparation of the product which can be shipped to physician the same day of the prescription. An intra corpuscular activity of L-asparaginase of 112±11,3 IU/ml of pure RBCs is obtained with an output of L-asparaginase encapsulation of 29,8± 2,1%. 250 ml-packed RBCs (hematocrit 50%), contains about 14000 IU. The encapsulation of L-asparaginase in the erythrocytes is a technology which strongly increases the half-life of the enzyme (29,2±9,7 days versus 24 hours) and reduces the immunogenicity of the enzyme. Here the red cell works as a bioreactor: L-asparaginase is maintained active inside the erythrocyte as long as this one is circulating. The plasmatic asparagine, a small size protein, penetrates passively and continuously towards the intra-erythrocyte compartment, where it is cleaved by the enzyme. In addition, the membrane of red blood cells avoids bindings between anti-asparaginase antibodies and the enzyme leading to decreased reactions of hypersensibility. A randomized multicenter phase II clinical trial including ALL patients in first relapse (GRASPALL) is currently ongoing in France and Belgium. The main objective is to establish a dose/effect relationship between 3 doses of entrapped L-asparaginase (50, 100, 150 IU/kg) or the free form of the enzyme and the duration of the plasmatic asparagine depletion (&lt;2 μmol/L). All patients receive a 6-drugs 4-weeks induction chemotherapy combining L-asparaginase (entrapped or non-) with dexamethasone, prednisone, vincristine, methotrexate and cytarabine as recommended by French and Belgium pediatric groups (COOPRALL). Twenty-one patients on the twenty-four patients planned, aged from 1 to 55 years (2 strates children and adults (more than 18yr) are already enrolled. GRASPA is given as a single injection once a month. The mean dosage (100 IU/kg) should be able to reach approximately 30 days of continuous plasmatic asparagine depletion. Thanks to the improvement of the pharmacokinetic and pharmacodynamic and especially to the side effects reduction, this new form of L-asparaginase is very promising especially in patients with a poor tolerance to the free form such as intolerant, hypersensitive or elderly patients.</jats:p

Catalytic Properties of Various Oxides and Mesoporous Materials Containing Niobium and Sulfate Ions, in the Oxidation Reaction of 1-Octanol

International audienc

Preparation and Catalytic Properties of Various Oxides and Mesoporous Materials Containing Niobium and Sulfate Ions, in the Etherification Reaction of 2-Naphtol

International audienc