The objective of this study was to explore intramolecular ketene cycloadditions with the anticipated results of developing new synthetic methodology for the synthesis of polycyclic compounds difficult to obtain by other procedures. (o-Alkenylphenoxy)ketenes were initially selected for this study because these ketenes provided a favorable proximity for the intramolecular [2+2] cycloaddition reactions. The difunctional precursors, (o-alkenylphenoxy)- acetic acids, were readily prepared from o-alkenylphenols and ∝-halocarboxylic acids and were converted to the corresponding acid chlorides by reaction with oxalyl chloride. The acid chlorides were dehydrochlorinated to the corresponding (o-alkenylphenoxy)ketenes by treatment with triethylamine. The ketenes undergo a facile intramolecular [2+2] cycloaddition to give polycyclic eye 1obutanones. The (o-vinylphenoxy)ketenes are clearly more reactive than the (o-allylphenoxy)ketenes and provide much better yields of the cycloaddition products because of electronic effects in the transition state in the cycloaddition process. The intramolecular [2+2] cycloadditions of keteniminium salts were included in this study as a more electrophilic alternative to ketenes that will react with less nucleophilic carbon-carbon double bonds. However, the use of keteniminium salts instead of ketenes in Intramolecular cycloadditions does have some limitations. The synthesis of benzofurans via the intramolecular [2+2] cycloadditions of (o-acylphenoxy)ketenes was accomplished. The initially formed ß-lactone cycloaddition products spontaneously underwent decarboxylation to the benzofurans. The aromaticity of the benzofurans is apparently a very strong driving force for the cycloaddition. During the course of this study, two new synthetic methods were discovered which in many instances represent a significant Improvement over existing methods. The Wittig Reactions of ketoacids without protecting the carboxyl groups provide a reliable source of the precursor unsaturated acids needed for intramolecular ketene-olefin cycloadditions. Also, the one-pot preparation of intramolecular ketene cycloaddition products from the carboxylic acid via the tosylate represents a new synthetic method. This procedure eliminates the acid halide preparation, isolation and purification step, thereby significantly simplifying the synthesis.

The Altona Formation represents the oldest Cambrian sedimentary unit in northern New York, recording cyclic deposition in shallow marine and fluvial environments under both fair-weather and storm conditions. Five outcrops and one well log were measured and described at the centimeter scale and the top and bottom contacts of the Altona were identified. Based on the recognition of sedimentary structures such as hummocky cross stratification, oscillatory ripples, graded bedding, trough and tabular cross stratification, and bioturbation, as well as subtle lithologic changes, six lithofacies representing non-marine, middle to upper shoreface, offshore, and carbonate ramp environments were identified. The top contact with the overlying Ausable Formation is characterized by inter-tonguing marine to non-marine siltstones and cross stratified medium sandstones. The lowermost Altona is found to lie only one meter above Precambrian basement and is interpreted to be the only non-marine facies in this unit. Throughout the 84-meter thick section, stratigraphy records a transition from upper/middle shoreface to carbonate ramp deposition and offshore muds before cycling between upper shoreface, carbonate ramp and non-marine deposits. Based on parasequence architecture, this section of rock is interpreted to represent the transition from the transgressive systems tract to the highstand systems tract. Thin sections analysis from each lithofacies quantified grain size and composition and identified a provenance. Modal analysis data from clastic lithofacies reveals subarkose to arkose sandstones with an accessory mineral suite including ilmenite, apatite, rutile, and zircon. Integrating the compositional data, particularly the accessory mineral suite, with detrital zircon dates of 1000 - 1300 Ma (Chiarenzelli et al., 2010) suggests that the Grenville Adirondacks in particular the AMCG suit and Lyon Mountain Granite are a likely source rock. Comparison with the Monkton Formations of Vermont suggest that these two units were deposited under similar sea level conditions and are therefore correlative. Provenance study suggests that they were both sourced form the Adirondack Mountains. The major difference is in their depositional environments as the Monkton represents deposition of predominantly tidally influenced deltaic environment. The environmental processes acting on the two units suggests that the paleogeography of the Iapetus margin in this area was an embayed coastline.

Formações ferríferas neoproterozóicas são mundialmente conhecidas e trata-se de um tipo peculiar de depósito não só pelos aspectos econômicos, mas por estarem, geralmente, relacionadas a depósitos de origem glacial. A presente dissertação aborda as ocorrências de formações ferríferas associadas à diamictitos glaciogênicos da Formação Puga na região de Bodoquena, estado do Mato Grosso do Sul. Foram realizados processamentos de dados aeromagnetométricos, mapeamento geológico, caracterização petrográfica e geoquímica, além da avaliação dos recursos. Os dados aeromagnéticos foram eficientes para o delineamento da área de abrangência da formação ferrífera. A mesma constitui-se de camadas de óxidos de ferro disseminados, alternados com sílica. Blocos isolados ocorrem associados a formação ferrífera mas a ação tectônica dificulta a observação das relações entre os clastos e o bandamento original. As evidências geológicas observadas mostram que a deposição da Formação Puga teve contribuição de um componente glacial, provavelmente relacionada ao evento Varangeriano/Marinoano. A Formação Puga deve ter se depositado num ambiente hidrotermal distal misto com a precipitação de fluidos ferrríferos hidrotermais em sedimentos detríticos glaciais. A avaliação regional dos recursos de Bodoquena, através do uso de métodos convencionais, mostra que a região tem um potencial em torno de um bilhão de toneladas de recursos de ferro. Ensaios de caracterização tecnológica resultaram em uma recuperação final de aproximadamente 65% em massa, com um teor médio de 55% de Fe. Isto implica em produtos que atendem as especificações de mercado. / Neoproterozoic iron formations are worldwide known and they are a very peculiar kind of deposit not only by economic aspects but also they are usually related to glacial deposits. This dissertation focus on iron formation associated with glaciogenic diamictites interpreted as belonging to the Puga Formation, in Bodoquena, state of Mato Grosso do Sul. To this deposit magnetic survey, geological mapping, geochemical and petrographical characterization, as well as iron resource evaluation have been done. Moreover, aeromagnetic data were effective to delineate the total iron formation coverage. Its mostly composed of fine disseminated iron oxide layers alternated with silica. Isolated blocks occur within the iron formation but tectonic overprinting makes it difficult to have a clear observation of the relationship between clasts and original lamination. The geological evidences observed show that the Puga Formation had a glacial contribution during its deposition, and probably is related to the Varanger/Mar inoan event. It may have deposited in a distal hydrothermal environment with the ferruginous fluid precipitation together with glacial sediments. The regional evaluation of Bodoquena resources through conventional methods shows that this region has geological resource potential for more than one billion tons of iron ore. Technological characterization tests results in 65% mass recovery w ith 55% Fe. This implies in products that attend to merchantable specifications.

Formações ferríferas neoproterozóicas são mundialmente conhecidas e trata-se de um tipo peculiar de depósito não só pelos aspectos econômicos, mas por estarem, geralmente, relacionadas a depósitos de origem glacial. A presente dissertação aborda as ocorrências de formações ferríferas associadas à diamictitos glaciogênicos da Formação Puga na região de Bodoquena, estado do Mato Grosso do Sul. Foram realizados processamentos de dados aeromagnetométricos, mapeamento geológico, caracterização petrográfica e geoquímica, além da avaliação dos recursos. Os dados aeromagnéticos foram eficientes para o delineamento da área de abrangência da formação ferrífera. A mesma constitui-se de camadas de óxidos de ferro disseminados, alternados com sílica. Blocos isolados ocorrem associados a formação ferrífera mas a ação tectônica dificulta a observação das relações entre os clastos e o bandamento original. As evidências geológicas observadas mostram que a deposição da Formação Puga teve contribuição de um componente glacial, provavelmente relacionada ao evento Varangeriano/Marinoano. A Formação Puga deve ter se depositado num ambiente hidrotermal distal misto com a precipitação de fluidos ferrríferos hidrotermais em sedimentos detríticos glaciais. A avaliação regional dos recursos de Bodoquena, através do uso de métodos convencionais, mostra que a região tem um potencial em torno de um bilhão de toneladas de recursos de ferro. Ensaios de caracterização tecnológica resultaram em uma recuperação final de aproximadamente 65% em massa, com um teor médio de 55% de Fe. Isto implica em produtos que atendem as especificações de mercado. / Neoproterozoic iron formations are worldwide known and they are a very peculiar kind of deposit not only by economic aspects but also they are usually related to glacial deposits. This dissertation focus on iron formation associated with glaciogenic diamictites interpreted as belonging to the Puga Formation, in Bodoquena, state of Mato Grosso do Sul. To this deposit magnetic survey, geological mapping, geochemical and petrographical characterization, as well as iron resource evaluation have been done. Moreover, aeromagnetic data were effective to delineate the total iron formation coverage. Its mostly composed of fine disseminated iron oxide layers alternated with silica. Isolated blocks occur within the iron formation but tectonic overprinting makes it difficult to have a clear observation of the relationship between clasts and original lamination. The geological evidences observed show that the Puga Formation had a glacial contribution during its deposition, and probably is related to the Varanger/Mar inoan event. It may have deposited in a distal hydrothermal environment with the ferruginous fluid precipitation together with glacial sediments. The regional evaluation of Bodoquena resources through conventional methods shows that this region has geological resource potential for more than one billion tons of iron ore. Technological characterization tests results in 65% mass recovery w ith 55% Fe. This implies in products that attend to merchantable specifications.

Le sujet de cette thèse est la phase d'accrétion emballée du gaz lors de la formation des planètes géantes, au moyen de simulations hydrodynamiques. Une planète de la masse de Jupiter est simulée au sein d'un disque circumstellaire autour d'une étoile de masse solaire. Grâce aux grilles emboitées du code JUPITER, le voisinage de la planète est résolu suffisamment pour étudier le disque circumplanétaire. Des simulations 3D localement isothermes révèlent que l'accrétion est un processus fondamentalement tridimensionnel, avec 90% du gaz accrété verticalement à travers le sillon ouvert par la planète, via une circulation méridienne entre les disques circumstellaire et circumplanétaire. Le taux d'accrétion est mesuré à partir de simulations sans viscosité, en accord avec les conditions qui règnent dans l'environnement planétaire. On trouve que Jupiter doublerait sa masse en un demi million d'années durant cette phase emballée, ce qui est similaire au temps de dispersion du disque, et pourrait donc expliquer la rareté des exoplanètes très massives (plus de 3 masses de Jupiter). En ajoutant les effets thermiques au code Jupiter, nous avons réalisé des simulations radiatives, avec des températures plus réalistes. Celles-ci montrent que la température de la planète influence fortement les propriétés de la matière circum-planétaire : même une planète assez massive pour ouvrir un sillon ne peut former qu'une enveloppe planétaire supportée par la pression si sa température est élevée (~13000 K), comme une planète de faible masse. Au contraire, dans les simulations où la température au voisinage de la planète est bornée à 1000-2000 K, un disque circum-planétaire se forme. / This thesis is focusing on the runaway gas accretion phase of giant planet formation with hydrodynamic simulations. A Jupiter-mass planet is simulated embedded in a circumstellar disk around a Solar-mass star. Thanks to the JUPITER-code nested meshing technique, the planet vicinity is resolved with high resolution allowing to study the circumplanetary disk formed around the giant planet. Isothermal, 3-dimensional simulations revealed that the accretion is truly 3D process, with 90% of the gas accreted from the vertical direction through the planetary gap. This vertical influx is part of a meridional circulation between the circumstellar and circumplanetary disks. The accretion rate to planet was determined from inviscid simulation, in order to account for the presumably low viscosity environment in the forming planet’s vicinity. In this inviscid limit, the mass doubling time in the runaway phase can be as long as half a million years, competing with the gas dispersal timescale, hence providing a possible solution for the missing population of massive (>3 Jupiter-mass) giant planets. Incorporating the thermal effects into the JUPITER-code, radiative simulations with more realistic temperature information were carried out as well. These simulations revealed that the planetary temperature greatly determines the properties of the circumplanetary material. Even a gap-opening giant planet could only form a circumplanetary, pressure-supported envelope, if the planet temperature is high (~13,000 Kelvin), similarly to low-mass planets. In contrary, in the simulations were the central temperatures were capped at 1000-2000 Kelvins, circumplanetary disks were formed.

The Jasper Hiemstra limestone quarry outside of Delta, Iowa, preserves an aquatic and terrestrial fauna from the Late Mississippian of Midwestern North America. Stratigraphic and paleontological data demonstrate that the quarry correlates with the Ste. Genevieve Formation, approximately 330 million years (Ma) ago. The site formed in a karst terrain with at most minor marine influence. Numerous invertebrate and as-yet undefined vertebrate taxa are preserved. Three new vertebrate taxa are described here for the first time. Eustreptogyracanthus iaspius is a gyracanth gnathostome that possesses unique sculpturing on the pectoral fins. It is associated with scales and elements of the pectoral girdle, similar to those seen elsewhere in the group. Floydus punicellus is a rhizodontid sarcopterygian that possesses a partially ossified brain case, enlarged pelvis, sculptured underside to the postparietals and anteroposterior lateral line enervation of the postparietals and supratemporals. Aliuslater inmuri is an actinopterygian that possesses an unusual upper jaw. Previous workers have found evidence for a consistant tetrapod province around the world over a period of time that includes the Hiemstra Quarry's deposition, but the present analysis does not find strong support for this hypothesis.

The broad aim of the work presented in this thesis was to examine the relationship between the mineral and organic phases of calcium oxalate monohydrate (COM) crystals, which are the principal components of human kidney stones. The results presented, clearly demonstrate the presence of some amino acids and urinary proteins in the crystals and suggest a role for intracrystalline proteins in urolithiasis. The adsorptive affinities of twenty amino acids to COM, calcium hydrogen phosphate, tricalcium phosphate and hydroxyapatite were assessed over the physiological urinary pH range (pH 5-8) in aqueous solutions. In all cases adsorption was strongest at pH 5 and decreased as the pH increased as a result of the increasing negative charge of both substrate and adsorbate. Binding was higher to COM than to the phosphate minerals, owing to differences in the surface charge or coordination-site availability. Aspartic acid (Asp), glutamic acid (Glu) and y- carboxyglutamic acid (Gla), which each have at least two carboxyl groups, exhibited the highest binding affinities, suggesting that binding occurs by chelation. Further, binding affinity was reasoned to result from the ability of the zwitterions of Asp, Glu and Gla to adopt favourable conformations in which two carboxyl groups, and possibly the amino group, can interact with the mineral surface without further rotation. Although free amino acids are unlikely to fulfil a prominent inhibitory role in stone pathophysiology, they could, nonetheless, fulfil an important function as terminal residues or as exposed components of calcium-binding domains of proteins involved in stone formation. The existence of intracrystalline proteins and amino acids in COM crystals was demonstrated by Synchrotron X-ray Diffraction (SXRD) analysis. / Non-uniform strains and crystallite sizes were derived from SXRD whole pattern line widths using Rietveld analysis, which showed an increase in average non-uniform strain and a decrease in average crystallite size. These were attributed to intracrystalline molecules. Occluded molecules were Glu, Gla, human prothrombin (PT) and to a lesser extent, human serum albumin (HSA), as well as crystal matrix extract (CME), which comprises a complex mixture of soluble organic molecules remaining after demineralization of COM crystals grown in centrifuged and filtered (CF) urine. COM grown in CF urine possessed greater non-uniform strain and smaller crystallite size than COM grown in ultrafiltered (UF) urine, indicating that the majority of intracrystalline macromolecules in crystals derived from CF urine were >10kDa in molecular mass. Asp, AspAsp, GluGlu and Tamm Horsfall glycoprotein (THG) were non-occluded molecules. Proteinase treatment of COM crystals grown in CF urine produced a marked decrease in non-uniform strain and an increase in crystallite size, suggesting that smaller crystallite material, more intimately associated with proteins than the bulk COM, was liberated during the treatment. A reciprocal relationship was found between non-uniform strain and crystallite size, which was dependent upon the type of molecule(s) in which the COM crystals were grown. For a given increment in non-uniform strain, the corresponding decrease in crystallite size was found to be considerably greater for occluded macromolecules, than for amino acids. This difference was attributed to the capacity of macromolecules, once incorporated into the crystal, to disrupt a larger volume of the mineral bulk than amino acids. Alternatively, unlike amino acids, macromolecules might possibly stabilise an amorphous phase. / Amorphous contributions resulting from the occlusion of PT and molecules from CF urine and UF urine in COM were found to range between 5-9%. The SXRD data derived from the COM crystals were further analysed for anisotropy using Williamson-Hall plots and individual peak analysis (SHADOW). Crystals grown in distilled water COM (distilled water) and COM (Asp, AspAsp, GluGlu, Gla, HSA, THG and PT) were isotropic with respect to both non-uniform strain and crystallite size. Although COM (Glu) and COM (UF) were isotropic with respect to non-uniform strain, the crystallite sizes were smaller along the (100) and (001) principal axes, respectively. COM (CF urine) and COM (CME) were also anisotropic, but with respect to crystallite size, with the shortest lengths occurring along the (100) and (001) axes. The absence of anisotropy in non-uniform strain was ascribed to experimental error. The data also showed that stacking faults contributed significantly to crystal disorder. Largest stacking faults, highest non-uniform strain and lowest crystallite sizes were generally found along the (13i) plane. Computer- generated models showed that molecules as large as proteins could not effectively be incorporated along the (13i) plane in COM. It was concluded therefore, that they transmit disorder from the principal (100,010, 001) planes in the crystal to the (13i) plane by diagonal sliding of one or more rows of oxalate ions, calcium ions and water molecules. SXRD single peak and whole pattern analysis of COM crystals grown in aqueous solutions of increasing concentrations of PT, HSA, CME and Gla showed that non- uniform strain increased, crystallite size decreased and stacking faults increased, to limiting values. / This was also found for crystals grown in UF urine containing CME and HSA. When crystals with occluded proteins were treated with proteinase K, their stacking faults and non-uniform strain decreased, and crystallite size increased, indicating that the non-crystalline material is more intimately associated with the protein and is physically removed or solubilised when the protein is destroyed. FESEM observations of the internal architecture of fractured CaOx crystals grown in human urine and synthetic solutions containing PT, revealed an inhomogeneous microstructure containing low density zones not observed in COM crystals grown in water or UF urine. Proteolytic treatment of the fractured crystals, created an internal honey combed structure that replaced the “low-density” zones. A timed growth study showed the internal ultrastructure of urinary COM crystals depended to a significant extent, upon the ratio of crystal-binding proteins to the available quantities of solute ions during growth. Dissolution studies of COM crystals showed that the process obeyed the Shrinking Core model and was therefore surface area-dependent. Pure COM dissolved more rapidly than crystals derived from UF urine, which dissolved at a faster rate than crystals precipitated from CF urine. This was attributed to shielding of the exposed COM surface by occluded molecules, which would reduce the effective surface area and slow dissolution. There is also the possibility that the macromolecules would have bound to the ions and retard their release into solution. The use of proteinase inhibitors verified the presence of proteinases in fresh urine and showed that they were capable of attacking proteins occluded in COM, in particular, proteins with Mr > 10kDa. / Although COM (CF) crystals were more difficult to dissolve than COM (UF) crystals in aqueous solutions, they were far more susceptible to endogenous proteolytic degradation in urine. Collectively, these findings have formed the basis of a novel hypothesis, which proposes that the type and concentration of urinary proteins incorporated inside CaOx crystals are fundamental to the disposal of CaOx crystals precipitated and retained within the renal system, and may therefore play an important role in the prevention of urolithiasis.

Dans l'apprentissage de la maîtrise des risques, l'outil le plus couramment utilisé est aujourd'hui la formation, qui doit chercher à faire produire des comportements de sécurité aux individus. Nous avons mené une réflexion sur les comportements de sécurité liés à la maîtrise de risques industriels et sur les actions susceptibles de les faire émerger, notamment au travers de la représentation du risque. Nous avons construit un modèle de production de comportements à visée opérationnelle, basé d'une part sur une approche cognitive et affective et d'autre part sur une approche situationnelle. Pour cela, nous avons fait appel à la communication persuasive et à la théorie de l'engagement. Par une démarche de « Recherche Action », nous avons élaboré une formation à la maîtrise des risques pour un groupe pharmaceutique, dans un objectif de changement « culturel ». Par la mise en place d'un programme expérimental, nous avons également participé à la production de connaissances utiles pour l'action. Parallèlement, nous nous sommes intéressés à une formation informative et comportementale dispensée par les sapeurs-pompiers, reconnue pour son impact positif sur la sécurité. En essayant d'en comprendre les leviers d'action, nous avons pu l'optimiser et construire les bases du concept de formation engageante. La formation à la maîtrise des risques se doit d'être un processus spécifiquement ciblé et non plus un dispositif informatif généraliste. En permettant aux individus de basculer dans un mode comportemental, ils acquièrent ainsi un véritable statut d'acteurs de la maîtrise des risques.

The upper Llandovery succession across the Jupiter-Chicotte formational contact on Anticosti Island, Québec, allows us to study the sediment dynamics and stratigraphic architecture of a storm-dominated, carbonate ramp. The Anticosti paleotropical ramp was slowly subsiding and recording significant changes in sea level in a far field glacial setting during the early Telychian. Three facies associations, grouping nine facies, are recognized along the E-W outcrop belt, and from top to bottom as the: (FA-1) encrinitic carbonate facies, (FA-2) mixed siliciclastic and carbonate facies, and (FA-3) non-encrinitic carbonate facies. These mid to outer ramp sediments represent deposition mostly from episodic, high-energy storm events as evidenced by hummocky cross-stratification, large wave ripples, gutter casts, and wave-enhanced sediment-gravity flow deposits. Spatial and temporal changes in siliciclastic content imply basin margin depositional environments in the eastern sections and change in climate regime from arid to humid conditions. The Chicotte deposition marks a major faunal change with the domination of crinoids triggered by increasing siliciclastic supply, rapid sea level fluctuations and change in substrates. The recognition of one major transgressive-regressive (TR) sequence subdivided in distinct meter-scale cycles allows a high resolution E-W correlation. The development of the TR sequence and meter-scale cycles is driven by glacio-eustacy where the main sequence is 4th order (~400 Ky) with superimposed meter-scale cycles that are 5th and/or 6th order (~100 Ky). Nevertheless, erosional capping surfaces within the more proximal tempestites represent ancient rocky shorelines that developed during forced sea level falls. In order to explain this stratigraphic architecture, a carbonate open-ramp model is proposed with a concave-up profile and a narrow and steep inner ramp in equilibrium with a high-energy coastline.

Cette recherche est de type théorique et interprétatif. La démarche vise la compréhension du concept d'approche culturelle en enseignement proposée par le ministère de l'Éducation, comme l'une des composantes des deux volets de la formation initiale des maîtres au Québec: la professionnalisation et l'approche culturelle en enseignement. L'auteur aborde l'analyse dans une perspective herméneutique centrée sur l'approche dite « anthropique », qui a comme centre une interprétation dynamique venant de la construction du sens que l'herméneute donne, à partir de la mobilité de sa pensée et de son expérience. La thèse aborde la compréhension de l'approche culturelle en enseignement, dans une perspective pédagogique, pour son utilisation en formation initiale des maîtres. La recherche étant théorique, le travail vise la construction d'un cadre de référence de type pédagogique pour l'accompagnement des futurs maîtres dans leur devenir en tant que « professionnels cultivés ». L'auteur expose ses influences théoriques, issues de sa pratique en tant qu'éducateur et formateur de maîtres. À partir de la mise en évidence de ses influences, l'auteur de la thèse « problématise » (s'interroge sur) le concept visé. Ces influences théoriques et conceptuelles passent par l'éducation populaire issue de la philosophie de la libération et de la pédagogie de la libération latino-américaine, le courant autobiographique et celui des histoires de vie en formation, la théorie du projet, l'esthétique de la pédagogie comme cadre de référence pour une définition de la relation pédagogique. Par une démarche d'interprétation herméneutique et une méthodologie basée sur trois moments d'élaboration, l'auteur crée des liens, problématise la compréhension du concept d'approche culturelle à l'enseignement, et propose un modèle d'accompagnement des futurs maîtres en formation. Les trois moments d'élaboration de la thèse peuvent se résumer ainsi: l'interprétation, l'argumentation et le raconter. Le processus est décrit comme une démarche d'exploration critique, sur les bases des expériences et connaissances de l'auteur, afin d'arriver à l'élargissement de la compréhension de l'objet visé (le concept d'approche culturelle) et de ses applications pédagogiques dans la formation initiale des maîtres.