Ability of nitrones of various structures to control the radical polymerization of styrene mediated by in situ formed nitroxides

in Polymer (2005), 46(23), 9632-9641

The ability of several nitrones to control the radical polymerization of styrene at 110 °C has been investigated by high-throughput experimentation. The nitrone/free radical initiator pair dictates the ... [more ▼]

The ability of several nitrones to control the radical polymerization of styrene at 110 °C has been investigated by high-throughput experimentation. The nitrone/free radical initiator pair dictates the structure of the nitroxide and the alkoxyamine formed in situ, which determines the position of the equilibrium between the active and the dormant species operating in the nitroxide-mediated polymerization. For the styrene polymerization to be controlled, the nitrone must be reacted with 2,2'-azo-bis-isobutyronitrile (AIBN) at 85 °C, prior to addition of styrene and polymerization at 110 °C. The effect of the nitrone structure on the kinetics of the styrene polymerization has been emphasized. Amongst all the nitrones tested, those of the C-phenyl-N-tert-butylnitrone (PBN) type are the most efficient in terms of polymerization rate, control of molecular weight and polydispersity. Electrophilic substitution of the phenyl group of PBN by either an electrodonor or an electroacceptor group has only a minor effect on the polymerization kinetics. Importantly, the polymerization rate is not governed by the thermal polymerization of styrene but by the alkoxyamine formed in situ during the pre-reaction step. The initiation efficiency is, however, very low, consistent with a limited conversion of the nitrone into nitroxide and alkoxyamine. [less ▲]

La réserve d’office des intérêts civils par le juge pénal et la mise en état des causes ( le nouvel article 4 du titre préliminaire du Code de procédure pénale )

in Journal des Tribunaux (2005), 6199

Le nouvel article 4 du titre préliminaire du Code de procédure pénale — tel que modifié par la loi du 13 avril 2005 — contient deux lignes de force. D’une part, il étend la réserve d’office des intérêts ... [more ▼]

Le nouvel article 4 du titre préliminaire du Code de procédure pénale — tel que modifié par la loi du 13 avril 2005 — contient deux lignes de force. D’une part, il étend la réserve d’office des intérêts civils par le juge répressif à toutes les affaires pénales et ce quel que soit le mode de saisine de la juridiction compétente. D’autre part, il organise une procédure de mise en état devant permettre aux parties intéressées d’obtenir un calendrier aux fins qu’il soit statué sur les intérêts civils. La contribution qui suit entend d’abord rappeler les modalités de l’exercice de l’action civile devant la juridiction pénale. Par la suite, elle s’attache à cerner les principes qui régissent la réserve d’office des intérêts civils et ses implications, tout particulièrement, sur les voies de recours et la prescription. Enfin, la dernière partie de l’article s’attache à examiner les divers problèmes engendrés par la mise en état des intérêts civils devant le juge pénal et les solutions susceptibles d’y être apportées. [less ▲]

Integrazione scolastica e immigrazione in Europa

Conference given outside the academic context (2005)

Bird and Environment

in Current Science (2005), 89(9), 1461-1462

Cartographie de l’accessibilité par les alternatives à la voiture

Conference (2005, November 09)

Grande bourgeoisie et politique en Belgique. L’exemple de l’industrie des médias

Conference given outside the academic context (2005)

Cultures de la qualité des services et cultures de l'accompagnement dans le secteur de l'éducation des jeunes enfants : essai de théorisation

Doctoral thesis (2005)

La thèse se présente comme un essai de théorisation des conceptions de la qualité des services et de leur accompagnement dans le secteur de l'éducation des jeunes enfants. Elle appréhende celles-ci sous ... [more ▼]

La thèse se présente comme un essai de théorisation des conceptions de la qualité des services et de leur accompagnement dans le secteur de l'éducation des jeunes enfants. Elle appréhende celles-ci sous le prisme de cultures, marquant le caractère construit de l'objet de recherche. Inspirée des méthodologies de la théorisation ancrée, elle propose deux approches complémentaires. La première interroge les usages de la notion de qualité dans les recherches sur l'éducation des jeunes enfants de manière à la fois diachronique et internationale ainsi que la référence à l'accompagnement dans les publications récentes parues en sciences de l'éducation et de la formation. La deuxième approche consiste à analyser les conceptions de la qualité des services et de leur accompagnement dans des débats menés dans des dispositifs de formation que l'auteure a elle-même mis en place. [less ▲]

Vers une démarche structurée de gestion forestière intégrée et participative

Learning material (2005)

This paper is aiming at presenting the main guidelines of a structured approach to an integrated forest management. Such a type of management that can be defined as being a concerted multipurpose ... [more ▼]

This paper is aiming at presenting the main guidelines of a structured approach to an integrated forest management. Such a type of management that can be defined as being a concerted multipurpose management takes into account numerous objectives that forest should be able to fulfil as well as the opinions of the actors involved in the forestry world. This approach consists of an evaluation and a subsequent multicriteria comparison of possible management alternatives. These management options and the expected consequences of their application on the future forest in terms of structure, composition and ability to meet all the expectations must be analyzed. In this respect scenario modellings are built, using simulations that suppose a good and very large knowledge of species autecology, site quality, level of biological quality. Various criteria and indicators are then used to assess the capacity of each alternative to achieve each defined and concerted objective. This is the starting point for comparisons between the management alternatives, based on the multicriteria decision-making technique, the so called ELECTRE III. This promising method has been tested in the context of a belgian pilot forest covering nearly 800 hectares in which foresters, private and public forest owners, hunters, naturalists, walkers and some other stakeholders are deeply involved. [less ▲]

Modulation of intestinal urea cycle by dietary spermine in suckling rat

in Biochemical and Biophysical Research Communications (2005), 336(4), 1119-1124

Argininosuccinate synthetase, an ubiquitous enzyme in mammals, catalyses the formation of argininosuccinate, the precursor of arginine. Arginine is recognised as an essential amino acid in foetuses and ... [more ▼]

Argininosuccinate synthetase, an ubiquitous enzyme in mammals, catalyses the formation of argininosuccinate, the precursor of arginine. Arginine is recognised as an essential amino acid in foetuses and neonates, but also as a conditionally essential amino acid in adults. Argininosuccinate synthetase is initially expressed in enterocytes during the developmental period, it disappeared from this organ then appeared in the kidneys. Although the importance of both intestinal and renal argininosuccinate synthetases has been recognised for a long time, nutrients have not yet been identified as inducers of the gene expression. In the context of a proteomic screening of intestinal modifications induced by dietary spermine in suckling rats, we showed that argininosuccinate synthetase and carbamoyl phosphate synthase disappeared from enterocytes after this treatment. The disappearance of argininosuccinate synthetase in small intestine was confirmed by immunodetection. Expression of carbamoyl phosphate synthase and argininosuccinate synthetase coding genes decreased also after spermine administration. Expression of other urea cycle enzyme coding genes was modulated by spermine administration: argininosuccinate lyase decreased and arginase increased. Our results fit with the developmental variation of argininosuccinate synthetase and carbamoyl phosphate synthase. Modulation of the gene expression for several urea cycle enzymes suggests a coordination between all the pathway steps and switch toward polyamine (or proline and glutamate) biosynthesis from ornithine. (c) 2005 Elsevier Inc. All rights reserved. [less ▲]

An O(1) Solver for the Helmholtz Equation

Scientific conference (2005, November 04)