De l'ancienne à la nouvelle économie : un processus de modernisation sociale de l'industrie

Cette recherche est réalisée dans le cadre d'une bourse post-doctorale accordée par le Conseil de recherche en sciences humaines du Canada (CRSH). Elle fut menée sous la supervision de Pierre-André Julien, directeur de la Chaire Bombardier en gestion du changement technologique dans les PME, elle-même partie intégrante de l'Institut de recherche sur les PME (INRPME) de l'Université du Québec à Trois-Rivières. Dans le contexte du passage de l'ancienne à la nouvelle économie, nous proposons une analyse socio-économique de la modernisation sociale de l'industrie. Notre objectif premier est d'identifier, puis de comprendre comment les diverses logiques d'action des acteurs présents permettent, tant au niveau économique (industriel et technologique) que politique (participation) ou culturel (identité), de construire des mondes réels de production qui débouchent sur des avantages comparatifs. La perspective qui est développée dans cette recherche s'appuie sur l'hypothèse que le secteur (ou l'industrie) et le territoire constituent les deux principaux espaces intermédiaires à l'intérieur desquels les échanges économiques se construisent. Ces échanges s'établissent à travers des processus d'auto-organisation des acteurs ainsi que dans le cadre de réalisation de la politique publique. Le présent document vise à développer une problématique pour appréhender cette modernisation sociale de l'industrie ainsi qu'à construire une grille d'analyse pour opérationnaliser la démarche. Pour y parvenir, nous nous sommes fortement inspirés de l'approche monographique développée par le Centre de recherche sur les innovations sociales dans l'économie sociale, les entreprises et les syndicats (CRISES) pour analyser les processus de modernisation sociale des entreprises. La méthodologie ainsi que les grandes dimensions analytiques développées par ce groupe de recherche sont à la base de notre propre démarche. Deux types de secteurs ont été choisis pour l'analyse empirique : d'une part une industrie typique de la nouvelle économie (multimédia), caractérisée du côté de l'offre par la prépondérance du savoir scientifique, et du côté de la demande par une incertitude radicale; d'autre part d'une industrie typique de l'ancienne économie (meuble) avec du côté de l'offre des relations basées sur le métier et la tradition, et du côté de la demande par des produits standards. Dans une étape préliminaire, nous avons produit des « états de la situation » pour les deux industries choisies (Bourque, 1999, 2000). Des analyses plus globales, et comparatives, devraient suivre dans une étape ultérieure

Evaluation of anomalies observed on film from S-190A flight system calibration test

Due to a persistent problem of scratched film from testing of the Skylab S-190A system, a series of tests were designed to identify the cause of the film scratching. The procedures followed in this test for pretest handling and packaging of the film, the makeup of the rolls for processing, and the results of the processed film evaluation are reported

Coordination and Organometallic Chemistry of Novel Gallium Complexes: Synthesis, Reactivity and Spectroscopy

The work described in this thesis incorporates three main themes: the synthesis and reactivity of new coordination and organometallic gallium compounds, and the chemical state determination of molecular gallium complexes using XPS and XAS. The coordination chemistry of low valent gallium cations was explored using macrocyclic ethers as ligands. The experimental oxidation number, or chemical state, of newly synthesized low valent gallium cationic complexes was compared to known compounds to allow for the assessment of the electronic environment at gallium. The organometallic chemistry of gallium was examined using donor ligands to stabilize monomeric organogallium(III) compounds, demonstrating the ability to substitute the ligands on gallium and to generate a compound containing a gallium-carbon double bond. Two multinuclear low valent gallium cations were synthesized using cryptand[2.2.2] as a stabilizing ligand and Ga2Cl4(THF)2 as a starting material. Conventional characterization techniques and computational methods were used to examine the structure and bonding of the cationic gallium cores contained within the cryptand ligand. These compounds are the first examples of binuclear cryptand[2.2.2] complexes, where two metal centres are located within the cryptand cavity. The experimental chemical states, namely the experimentally determined electronic environments or partial charges, of the gallium centres in two gallium-cryptand[2.2.2] complexes were evaluated using X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS) as a means of probing the electronic environment of the gallium centres. The experimental XPS data of the gallium-cryptand complexes were compared to known gallium compounds with unambiguously assigned oxidation numbers to determine the electron density at the gallium centres and to allow for an assessment of their potential reactivity. To overcome the instrumental limitations of the XPS experiments, XAS studies of the synthesized gallium-cryptand[2.2.2] complexes and other low valent gallium compounds with multiple gallium atoms were performed to separate the signals originating from the individual gallium centres. The higher resolution of the XAS data allowed for the observation of multiple signals from gallium centres with different assigned oxidation numbers within a single complex and gave additional information on the electronic structure and bonding of the cryptand complexes in conjunction with computational studies. The synthesis and reactivity of a gallium(I) cationic complex using 12-crown-4 as a stabilizing ligand was explored. The synthesis of [Ga(12-crown-4)][GaCl4] was achieved in one step from commercially available starting materials. Anion exchange reactions to replace the reactive tetrachlorogallate anion for the perfluorophenylborate were performed. [Ga(12- crown-4)][B(C6F5)4] was analyzed using XPS, which allowed for the classification of the gallium(I)-crown ether complex as electron deficient. Reactions of the gallium(I)-crown ether complex with Cp*K, cryptand[2.2.2], and DMAP demonstrated the facile synthesis of known gallium(I) compounds as well as the generation of novel gallium(I) cations, highlighting the use of the gallium(I)-crown ether complex as an effective starting material for new gallium(I) compounds. The synthesis of a compound with a gallium-carbon double bond, a gallene, was explored. The synthetic route utilized was inspired by strategies reported for the synthesis of compounds containing main group element-carbon double bonds with the key step being a dehydrohalogenation of a gallium(III) fluoride. The precursor organogallium(III) fluorides were synthesized using an NHC and DMAP as donors ligands to stabilize neutral species. Dehydrohalogenation of the gallium(III) fluoride was examined in an attempt to generate a gallene. Tolualdehyde was used as a trapping agent in situ, resulting in the formation of a 2:1 cycloadduct, giving evidence for the generation of an intermediate gallene. The synthetic route presented highlights the use of donor stabilization to facilitate ligand substitution and exchange reactions for neutral organogallium compounds

Structure of Mandelate Racemase with Bound Intermediate Analogues Benzohydroxamate and Cupferron

Mandelate racemase (MR, EC 5.1.2.2) from Pseudomonas putida catalyzes the Mg2+-dependent interconversion of the enantiomers of mandelate, stabilizing the altered substrate in the transition state by 26 kcal/mol relative to the substrate in the ground state. To understand the origins of this binding discrimination, we determined the X-ray crystal structures of wild-type MR complexed with two analogues of the putative aci-carboxylate intermediate, benzohydroxamate and Cupferron, to 2.2-Å resolution. Benzohydroxamate is shown to be a reasonable mimic of the transition state and/or intermediate because its binding affinity for 21 MR variants correlates well with changes in the free energy of transition state stabilization afforded by these variants. Both benzohydroxamate and Cupferron chelate the active site divalent metal ion and are bound in a conformation with the phenyl ring coplanar with the hydroxamate and diazeniumdiolate moieties, respectively. Structural overlays of MR complexed with benzohydroxamate, Cupferron, and the ground state analogue (S)-atrolactate reveal that the para carbon of the substrate phenyl ring moves by 0.8−1.2 Å between the ground state and intermediate state, consistent with the proposal that the phenyl ring moves during MR catalysis while the polar groups remain relatively fixed. Although the overall protein structure of MR with bound intermediate analogues is very similar to that of MR with bound (S)-atrolactate, the intermediate−Mg2+ distance becomes shorter, suggesting a tighter complex with the catalytic Mg2+. In addition, Tyr 54 moves closer to the phenyl ring of the bound intermediate analogues, contributing to an overall constriction of the active site cavity. However, site-directed mutagenesis experiments revealed that the role of Tyr 54 in MR catalysis is relatively minor, suggesting that alterations in enzyme structure that contribute to discrimination between the altered substrate in the transition state and the ground state by this proficient enzyme are extremely subtle

Maternal iron homeostasis: Effect on placental development and function

Iron is an essential mineral that participates in oxygen transport, DNA synthesis and repair, and as a cofactor for various cellular processes. Iron deficiency is the most common nutritional deficiency worldwide. Due to blood volume expansion and demands from the fetal-placental unit, pregnant women are one of the populations most at risk of developing iron deficiency. Iron deficiency during pregnancy poses major health concerns for offspring, including intrauterine growth restriction and long-term health complications. Although the underlying mechanisms remain unclear, maternal iron deficiency may indirectly impair fetal growth through changes in the structure and function of the placenta. Since the placenta forms the interface between mother and baby, understanding how the placenta changes in iron deficiency may yield new diagnostic indices of fetal stress in affected pregnancies, thereby leading to earlier interventions and improved fetal outcomes. In this review, we compile current data on the changes in placental development and function that occur under conditions of maternal iron deficiency, and discuss challenges and perspectives on managing the high incidence of iron deficiency in pregnant women

Vascular Aging and Hemodynamic Stability in the Intraoperative Period

The proportion of elderly people in the population is steadily increasing, and the inevitable consequence is that this subpopulation is more frequently represented in common medical procedures and surgeries. Understanding the circulatory changes that accompany the aging process is therefore becoming increasingly timely and relevant. In this short review, we discuss aspects of vascular control in aging that are particularly relevant in the maintenance of intraoperative hemodynamic stability. We subsequently review the effects of certain notable anesthetic agents with respect to the aging vasculature

Politique et stratégie industrielle: analyse sociologique des approches concurrentielle, institutionnaliste et de la nouvelle approche keynésienne

Cet essai constitue la réponse à l'une de mes questions de synthèse. Il consiste d'abord à circonscrire et à définir le champ et les principaux concepts de la politique industrielle par rapport à l'ensemble des politiques publiques. Par la même occasion, un ensemble de liens sont soulignés entre ces politiques industrielles et des mesures relevant d'autres politiques publiques avec lesquelles elles peuvent être combinées dans le cadre d'une stratégie de développement. Toutefois, la plus grande partie de ce travail repose sur l'analyse de trois courants de pensée concernant leur réflexion sur la notion de politique industrielle. Nous en sommes venus à identifier trois grandes approches: une approche concurrentielle, unissant autour d'une foi inébranlable aux mécanismes du marché un ensemble d'interprétations des phénomènes économiques, des néolibéraux les plus fondamentalistes jusqu'au modèle le plus à la mode de l'action stratégique des firmes; une nouvelle approche keynésienne, opposée à la stratégie suicidaire et au courtermisme de l'approche précédente, rassemblant des keynésiens fidèles à l'esprit interventionniste de Keynes, mais déplaçant leurs préoccupations du côté de la demande vers celui de l'offre, proposant une stratégie compétitive fondée sur la coopération; enfin une approche dite "institutionnaliste", multidisciplinaire, partageant avec les autres approches un intérêt pour une action du côté de l'offre, mais dont la préoccupation principale réside dans l'interrogation des processus et des conditions des arrangements institutionnels favorables à de nouvelles stratégies de développement. Pour conclure, j'aimerais remercier Gilles Bourque pour sa direction et ses précieux commentaires, et signaler que mes recherches furent appuyées par une bourse du CRSH