Geochemistry and high-resolution chemostratigraphy of the Haynesville Formation, East Texas

textThe Upper Jurassic Haynesville Formation of East Texas and Louisiana is an organic-rich calcareous mudrock that is Kimmeridgian in age. It underlies the less calcareous Bossier Shale, and it overlies the Smackover Formation limestone. The Haynesville has low permeability, but a relative high porosity, compared to other mudrock formations. Mudrocks are the most common sedimentary rock and some of the most challenging to study, analyze and understand. Despite having a homogeneous appearance on a macroscopic scale, mudrocks often have high variability in facies and composition on the microscopic scale and elemental level. Many studies and methods have been developed to identify facies and stratigraphic variations in mudrocks. A complete understanding of these variations is valuable to comprehend paleoenvironments, paleoclimate and paleoceanographic conditions. Mudrocks studies are also beneficial to shale exploration because these formations, which have a high hydrocarbon content, can be targeted by oil and gas companies for exploration and production. Geochemical methods, chemostratigraphy in particular, will be used in this thesis to complement core description, petrophysical studies and sedimentological studies. This thesis focuses on acquiring chemostratigraphic data from X-Ray Fluorescence (XRF) and X-Ray Diffraction (XRD) measurements to identify elemental and mineralogical variations in the T. W. George core, from the Haynesville Formation in Harrison County, Texas. The data are linked to core description and are analyzed using Hierarchical Cluster Analysis (HCA) to acquire a better understanding of the paleoceanographic conditions and depositional environments that controlled the sediment deposition of the Haynesville Formation. The Haynesville Formation comprises a Ca-rich lower Haynesville, a more Ca-rich upper Haynesville, and underlies the Si-rich and Ca-poor Bossier. The dominant condition during deposition is anoxic/euxinic in the lower Haynesville becoming dysoxic in the upper Haynesville and more oxygenated in the Bossier Formation. The greenhouse climate of the Late Jurassic led to the deposition of strata yielding petroleum source rocks such as the Haynesville Formation that today have great economic value. Thus, studying the Haynesville has both academic and economic importance.Geological Science

Modélisation des erreurs thermiques des machines-outils numériques à cinq-axes

RÉSUMÉ Les erreurs thermiques des machines-outils numériques à cinq-axes sont la cause principale des erreurs quasi-statiques qui limitent la précision d’usinage de ces machines. Ce travail de recherche présente la méthodologie adoptée pour mesurer, modéliser et compenser les erreurs thermiques d’un centre d’usinage dues à la variation de son état thermique et de l’historique de son activité. Une approche expérimentale est adoptée, qui consiste à varier l’état thermique de la machine en exerçant ses axes selon différents cycles de chauffage et de refroidissement. Les écarts volumétriques dans le volume de travail de la machine sont périodiquement mesurés, ainsi que la puissance réelle des 5 axes et de la broche. Plusieurs capteurs et accessoires sont spécialement conçus ou adaptés pour garantir une stabilité thermique et permettre une mesure rapide et nette de l’erreur thermique. Une analyse volumétrique détaillée des erreurs thermiques permet de comprendre le comportement thermique volumétrique de la machine-outil, en particulier les axes qui causent les erreurs les plus importantes, les effets observés sur le comportement volumétrique de la machine, ainsi que les interactions thermiques des axes voisins. L’analyse volumétrique a permis d’identifier les axes rotatifs comme étant les causes principales des erreurs thermiques de la machine. Une étude plus approfondie des erreurs géométriques paramétriques utilise la méthode SAMBA, qui modélise ces erreurs et permet leur estimation. Les résultats permettent d’identifier les paramètres dominants d’erreurs thermiques. La modélisation de ces paramètres dominants est faite en fonction de la mesure de la consommation de puissance des axes rotatifs par la superposition de fonctions de transfert de 1er ordre à une entrée et une sortie. L’efficacité du modèle thermique est validée par deux méthodes. La première validation est faite par la comparaison de la simulation du modèle avec les mesures obtenues par un nouveau test qui utilise des séquences de chauffage complètement différentes. La deuxième validation consiste en un test d’usinage exécuté à la suite d’une routine de chauffage aléatoire, où la comparaison des coupes compensées et non-compensées met en évidence l’efficacité du modèle thermique. En résumé, cette recherche a contribué à la compréhension du comportement thermique de la machine-outil. Elle a aussi définit une méthodologie efficace de mesure, de modélisation et de compensation des erreurs thermiques.----------ABSTRACT Thermal errors of five-axis numerical machine tools are the main cause of quasi-static errors which limit the machining accuracy of these machines. This research presents the methodology adopted to measure, model and compensate the thermal errors of a machining center caused by the variation of its thermal state and its activity history. An experimental approach is adopted, in which the thermal state of the machine is altered by different heating and cooling routines of all machine axes. Volumetric errors in the machine work volume are measured periodically, as well as the true power of the 5 axes and the spindle. Several sensors and accessories are specifically designed or adapted to assure a thermal stability and allow a quick and clear measurement of the thermal error. A detailed volumetric analysis of thermal errors allows a comprehension of the thermal volumetric behavior of the machine tool, in particular the axes causing the biggest errors, the observed effects on the machine’s behavior and the thermal interactions between neighboring axes. The volumetric analysis identified the rotary axes as the main cause of machine’s volumetric error. A more detailed study of the parametric geometric errors is performed using the SAMBA method, which models these errors and estimates them. The results allowed the identification of dominant thermal error parameters. These dominant parameters are modelled as functions of the measured rotary axes power consumption by the superposition of single-input single-output first order transfer functions. The thermal model efficiency is validated using two methods. The first validation is done by comparing the model simulation to the measurements of a new test having different heating sequences. The second validation consists of a machining test that follows an arbitrary heating routine, where the comparison of compensated and uncompensated cuts highlights the thermal model’s efficiency. In summary, this research contributed to the understanding of the thermal behavior of the machine tool. It also defined an efficient methodology for measuring, modelling and compensating thermal errors

Synthesizing Strained Azatriseptane Frameworks

Embedding seven-membered rings into polycyclic aromatic molecules is attractive as they can exert an influence on molecular conformation that ultimately changes the solubility and π-electronics. The considerations in designing and synthesizing a highly strained azatriseptane framework is discussed herein. We employ a twofold macrocyclization strategy to form the [7,7,7]-system and through scoping various strategies identify a Friedel–Crafts approach is key. The synthetic limitations we have identified, in addition to the successes presented here, highlights the key challenges in forming triseptane frameworks and paves the way for second-generation analogues that may have various applications in optical as well as electronic organic materials

A Novel Role for CSRP1 in a Lebanese Family with Congenital Cardiac Defects

Despite an obvious role for consanguinity in congenital heart disease (CHD), most studies fail to document a monogenic model of inheritance except for few cases. We hereby describe a first-degree cousins consanguineous Lebanese family with 7 conceived children: 2 died in utero of unknown causes, 3 have CHD, and 4 have polydactyly. The aim of the study is to unveil the genetic variant(s) causing these phenotypes using next generation sequencing (NGS) technology. Targeted exome sequencing identified a heterozygous duplication in CSRP1 which leads to a potential frameshift mutation at position 154 of the protein. This mutation is inherited from the father, and segregates only with the CHD phenotype. The in vitro characterization demonstrates that the mutation dramatically abrogates its transcriptional activity over cardiac promoters like NPPA. In addition, it differentially inhibits the physical association of CSRP1 with SRF, GATA4, and with the newly described partner herein TBX5. Whole exome sequencing failed to show any potential variant linked to polydactyly, but revealed a novel missense mutation in TRPS1. This mutation is inherited from the healthy mother, and segregating only with the cardiac phenotype. Both TRPS1 and CSRP1 physically interact, and the mutations in each abrogate their partnership. Our findings add fundamental knowledge into the molecular basis of CHD, and propose the di-genic model of inheritance as responsible for such malformations

Regulation through Contortion: From Supramolecular Surface-Interaction to Tunable Spin Information Relays

This thesis encompasses a multifaceted exploration of polycyclic aromatic hydrocarbons (PAHs) and their implications in supramolecular chemistry, electron paramagnetic resonance (EPR), and the interplay of axial chirality within bridged biphenyl systems. Chapter I introduces the world of curved PAHs, investigating synthetic strategies to induce negative curvature in flat aromatic compounds. The focus then shifts to nitrogen-centered PAHs, emphasizing the synthesis of a novel triarylamine core intricately embedded with three heptagons, each sharing a C‒N bond. These efforts reveal promising preliminary results in the realm of supramolecular assemblies. In Chapter II, an in-depth analysis of EPR, specifically photoexcited chromophore‒radical systems, is presented, featuring novel perylene‒eTEMPO isomers and underscoring the importance of considering rotational conformers in interpreting spectroscopic data. Chapter III bridges foundational knowledge and complex system exploration, delving into axial chirality’s role in shaping the dynamics of photoinduced electron transfer. The synthesis of chromophore‒linker‒radical systems, with a strategic emphasis on the incorporation of a bridged biphenyl linker, elucidates the subtle nuances of axial chirality. This chapter not only serves as a pivotal bridge in the thesis, but also anticipates future directions, envisioning the extension of the chromophore‒linker‒radical family to more complex porphyrin chromophores, promising exciting possibilities for innovation in molecular design and chirality dynamics

Les endotoxines du genre Bordetella (structure, évolution et impact sur la virulence bactérienne)

Le genre Bordetella comporte à l heure actuelle neuf espèces, majoritairement responsables d infections respiratoires. B. pertussis, agent de la coqueluche, est le modèle de travail de cette thèse avec d autres espèces telles que B. holmesii et B. avium. Les endotoxines bactériennes sont les composants essentiels de la membrane externe des bactéries à Gram-négatif. Du point de vue chimique, ce sont des lipopolysaccharides (LPS) qui provoquent un grand nombre de désordres physiopathologiques allant de la simple fièvre, à faible dose, jusqu au choc endotoxinique mortel, à forte dose. L analyse structurale des LPS de Bordetella est la spécialité majeure du laboratoire et la structure des endotoxines de la plupart des espèces de ce genre y a été décrite. Il est admis que le lipide A, qui constitue la région hydrophobe des LPS, est responsable de la majorité des activités biologiques de ces molécules. Ainsi, la moindre variation structurale de ces molécules a une répercussion importante sur la reconnaissance hôte-pathogène, les activités biologiques et la virulence bactérienne. A titre d exemple, il a été mis en évidence que la modification spécifique, par substitution des groupes phosphate du lipide A, avec de la glucosamine, jouait un rôle majeur dans la modulation de la réponse immunitaire. Cette originalité structurale qui a été mise en évidence dans notre équipe chez B. avium, B. bronchiseptica puis chez B. pertussis; elle semble être un trait spécifique des Bordetelles. Il faut savoir que la coqueluche fait des ravages dans les pays sous-développés et touche les nouveau-nés dans de nombreux pays, comme la France, d une maladie infectieuse mortelle dans les cas graves. Le vaccin qui ne peut être injecté qu à l âge de 2-3 mois et dont les rappels ne sont pas régulièrement suivis est imparfait. Les spécialistes du domaine ont reconnu qu un complément antigénique serait nécessaire pour le rendre plus efficace. Au cours de cette thèse, nous avons analysé la structure des LPS d isolats cliniques de B. pertussis afin d étudier leur évolution et leur adaptation avec le temps ainsi que leur application vaccinale potentielle. De plus, concernant deux souches de B. pertussis, BP338 et BP18-323 nous avons contribué à la mise en évidence de nouveaux gènes impliqués dans la biosynthèse de la GlcN substituant les groupes phosphate de la région lipidique et à expliquer la différence de longueur du seul acide gras distinct entre les deux souches. L étude de l influence de ces éléments structuraux sur l activation du complexe, TLR4/MD-2 apporte de nouveaux éclairages sur les interactions entre les lipides A et ce récepteur. Nos études sur les isolats cliniques de B. holmesii, pathogène opportuniste responsable d affections de type coqueluche, montrent une grande hétérogénéité structurale du lipide A au sein d un même isolat. Nous avons montré dans cette souche la présence d un marqueur spécifique des souches de Bordetella, il s agit d un acide gras présent uniquement chez les lipides A des isolats humains. Nos travaux effectués sur des isolats cliniques de B. pertussis appartenant aux ères pré- et post-vaccinales et provenant de différents pays, montrent une perte du matériel génétique avec une déficience de certains antigènes majeurs. Nous avons démontré, via des méthodes physico-chimiques, que ces modifications ne concernaient pas les LPS de ces isolats. La stabilité de ces antigènes ainsi que nos méthodes de purification, nous permettent de proposer que ces LPS détoxifiés soient de bons candidats pour améliorer l efficacité des vaccins coquelucheux acellulaires. Enfin, toutes les études structurales présentées dans cette thèse ont permis de mieux comprendre la régulation de certains gènes en réponse à un stress extérieur. Elles participent, sur l exemple d un pathogène majeur, au déchiffrage des mécanismes moléculaires qui mènent à la virulence et à l adaptation bactérienne.The Bordetella genus is actually composed of nine species responsible for respiratory infections. B. pertussis, the agent of whooping cough, is the main model of this thesis along with other species such as B. holmesii and B. avium. Bacterial endotoxins are the major components of Gram-negative bacteria external membrane. From a chemical point of view, they are lipopolysaccharides (LPS) causing a high number of pathophysiological disorders ranging from low fever at weak doses, to lethal endotoxic choc at high ones. Structural analysis of the Bordetellae LPS is the major specialty of our group where the endotoxin structures of most species of the genus were described. It is well-known that lipid A, which constitutes the hydrophobic moiety of LPS, is responsible for the majority of biological activities of these molecules. Thus, any structural change of these molecules has an important impact on host-pathogen recognition, biological activities and bacterial virulence. For example, it has been demonstrated that the specific modification by grafting glucosamine on lipid A phosphate groups plays a major role in modulating the immune response. This structural peculiarity was highlighted by our team first in B. avium, B. bronchiseptica then in B. pertussis; it seems to be a unique trait of Bordetella. It should be noted that pertussis wreaks havoc in developing countries and affects newborns in several others, including France, where this infectious disease causes a significant death toll. The vaccine, which cannot be injected before the age of 2-3 months, could be improved and boosters are not regularly monitored. Experts in the domain have recognized the lack of an antigenic complement to make it more effective. In this thesis, we analyzed the structure of LPS from B. pertussis clinical isolates to study their evolution and adaptation over time along with their potential use in the design of new vaccines. In addition, regarding two strains of B. pertussis, BP338 and BP18-323, we have contributed to the identification of new genes involved in the biosynthesis of GlcN substituting the phosphate groups of the lipid moiety, which helped explaining the difference in the length of the single fatty acid differing between the two strains. The analysis of the influence of these structural elements on the activation of the receptor complex, TLR4/MD-2 sheds new light on the interactions between lipids A and this receptor. Our studies on clinical isolates of B. holmesii, an opportunistic pathogen responsible for pertussis-like illness, show great structural heterogeneity in the lipid A of these isolates. We showed the presence of a specific marker of Bordetella species, namely a fatty acid present only in the lipid A of human isolates. Our works on B. pertussis clinical isolates belonging to pre- and post-vaccine eras and coming from different countries show a loss of genetic material with a deficiency in certain major antigens. We have demonstrated, via physico-chemical methods, that these modifications did not affect the LPS of these isolates. The stability of these antigens and our ability to purify them, allow us to propose that detoxified LPS could be good candidates for improving the effectiveness of acellular pertussis vaccines. Finally, all structural studies presented in this thesis have provided insight into the regulation of certain genes in response to external stress. Our compiled work on a major pathogen is an important step in deciphering the molecular mechanisms leading to bacterial virulence and adaptation.PARIS11-SCD-Bib. électronique (914719901) / SudocSudocFranceF