Global ETD Search

21	Seeking the Face of God : a study on Augustine's reception in the mystical thought of Bernard of Clairvaux and William of St. Thierry Cvetković, Carmen Angela January 2010 (has links) The present thesis examines the way in which two twelfth century authors, the Cistercian monks, Bernard of Clairvaux (1091-1153) and William of St. Thierry (c. 1080-1148), used Augustine (354-430) in the articulation of their mystical thought. The approach to this subject takes into account the fact that in the works of all these medieval authors the “mystical” element is inescapably entangled with their theological discourse and that an accurate understanding of their views on the soul’s direct encounter with God cannot be achieved without a discussion of their theology. This thesis posits that the cohesion of Bernard’s and William’s mystical thought lies in their appropriation of the guiding principle of Augustine’s mystical theology: “You made us for yourself and our heart is restless until it rests in you” (conf. 1.1.1), reflected in the subtle interplay of three main themes, namely (1) the creation of humanity in the image and likeness of God, which provides the grounds for the understanding of the soul’s search for direct contact with God; (2) love as a longing innate in every human being, which explores the means to attain immediacy with God; and (3) the soul’s direct encounter with God, which discusses the nature of the soul’s immediate experience of the divine presence that can only be achieved in lasting fullness at the end of time. This examination of Bernard’s and William’s use of Augustine is structured on the basis of these three core themes which form the scaffolding of their mystical thought. Investigating the specific methods of their reception of Augustine will highlight the originality and uniqueness of each of the two Cistercian authors, who while drawing on the same patristic source use it nevertheless in various ways, by focussing on different aspects of Augustine’s immense oeuvre and by arriving at distinct mystical programmes. 270.092
22	Mechanistic insights into enzymatic and homogeneous transition metal catalysis from quantum-chemical calculations Crawford, Luke January 2015 (has links) Catalysis is a key area of chemistry. Through catalysis it is possible to achieve better synthetic routes, exploit molecules normally considered to be inactive and also attain novel chemical transformations. The development of new catalysts is crucial to furthering chemistry as a field. Computational chemistry, arising from applying the equations of quantum and classical mechanics to solving chemical problems, offers an essential route to investigating the underlying atomistic detail of catalysis. In this thesis calculations have been applied towards studying a number of different catalytic processes. The processing of renewable chemical sources via homogeneous reactions, specifically cardanol from cashew nuts, is discussed. All routes examined for monoreduction of a diene model by [Ru(H)(iPrOH)(Cl)(C₆H₆)] and [Ru(H)(iPrOH)(C₆H₆)]⁺ are energetically costly and would allow for total reduction of the diene if they were operating. While this accounts for the need of high temperatures, further work is required to elucidate the true mechanism of this small but surprisingly complex system. Gold-mediated protodecarboxylation was examined in tandem with experiment to find the subtle steric and electronic effects that dictate CO₂ extrusion from gold N-heterocyclic carbene activated benzene-derived carboxylic acids. The origin of a switch in the rate limiting step from decarboxylation to protodeauration with less activated substrates was also clearly demonstrated. Studies of gold systems are closed with examinations of 1,2-difluorobenzene C–H activation and CO₂ insertion by [Au(IPr)(OH)]. Calculations highlight that the proposed mechanism for oxazole-derived substrates cannot be extended to 1,2-difluorobenzene and instead a digold complex offers more congruent predicted kinetics. The lens of quantum chemistry was turned upon palladium-mediated methoxycarbonylation reactions. An extensive study was undertaken to attempt to understand the bidentate diphosphine ligand dependency on forming either methylpropanoate (MePro) or copolymers. Mechanisms currently suggested in literature are shown to be incongruous with the formation of MePro by Pd(OAc)₂ and bulky diphosphines. A possible alternative route is proposed in this thesis. Four mechanisms for methoxycarbonylation with Pd(2-PyPPh₂)ₙ are detailed. The most accessible route is found to be congruent with experimental reports of selectivity, acid dependency and slight steric modifications. A modification of 2-PyPPh₂ to 2-(4-NMe₂-6-Me)PyPPh₂ is shown to improve both selectivity and turnover, the latter by four orders of magnitude (highest transition state from 22.9 kcal/mol to 16.7 kcal/mol ∆G), and this new second generation in silico designed ligand is studied for its applicability to wider substrate scope and different solvents. The final chapter of this thesis is a mixed quantum mechanics and molecular mechanics (QM/MM) examination of an enzymatic reaction, discussing the need for certain conditions and the role of particular amino acid residues in an S[sub]N2 hydrolysis reaction. 541
23	Etude de l'implication des cellules microgliales et de l'α-synucleine dans la maladie neurodégénérative de Parkinson Moussaud, Simon 25 February 2011 (has links) (PDF) Les maladies neurodégénératives liées à l'âge, telle celle de Parkinson, sont un problème majeur de santé publique. Cependant, la maladie de Parkinson reste incurable et les traitements sont très limités. En effet, les causes de la maladie restent encore mal comprises et la recherche se concentre sur ses mécanismes moléculaires. Dans cette étude, nous nous sommes intéressés à deux phénomènes anormaux se produisant dans la maladie de Parkinson : l'agrégation de l'α-synucléine et l'activation des cellules microgliales. Pour étudier la polymérisation de l'α-synucléine, nous avons établi de nouvelles méthodes permettant la production in vitro de différents types d'oligomères d'α-synucléine. Grâce à des méthodes biophysiques de pointe, nous avons caractérisé ces différents oligomères à l'échelle moléculaire. Puis nous avons étudié leurs effets toxiques sur les neurones. Ensuite, nous nous sommes intéressés à l'activation des microglies et en particulier à leurs canaux potassiques et aux changements liés au vieillissement. Nous avons identifié les canaux Kv1.3 et Kir2.1 et montré qu'ils étaient impliqués dans l'activation des microglies. En parallèle, nous avons établi une méthode originale qui permet l'isolation et la culture de microglies primaires issues de cerveaux adultes. En comparaison à celles de nouveaux-nés, les microglies adultes montrent des différences subtiles mais cruciales qui soutiennent l'hypothèse de changements liés au vieillissement. Globalement, nos résultats suggèrent qu'il est possible de développer de nouvelles approches thérapeutiques contre la maladie de Parkinson en modulant l'action des microglies ou en bloquant l'oligomérisation de l' α-synucléine. Vieillissement Maladies neurodégénératives Maladie de Parkinson Neurodégénération Α-synucléine Oligomères Toxicité Dopamine Neurones Neuroinflammation Microglies Immunité du cerveau Lignée cellulaire C8-B4 Cultures primaires Méthode d'isolation in vitro Patch-clamp Electrophysiologie Canaux potassiques Kv1.3 - Kir2.1 Oxyde nitrique Cytokines
24	Characteristics Associated with Neonatal Carnitine Levels: A Systematic Review & Clinical Database Analysis Sutherland, Sarah C. 28 January 2013 (has links) Newborn screening programs measure analyte levels in neonatal blood spots to identify individuals at high risk of disease. Carnitine and acylcarnitine levels are primary markers used in the detection of fatty acid oxidation disorders. These analytes may be influenced by certain pre/perinatal or newborn screening related factors. The primary objective of this study was to explore the association between these characteristics and levels of blood carnitines and acylcarnitines in the newborn population. The study was composed of two parts: a systematic review and a clinical database analysis of existing newborn screening data. The systematic review results suggested considerable variability across studies in the presence and directionality of associations between analyte levels and birth weight, gestational age, age at time of blood spot collection, type of sample, and storage time. Sex was not significantly associated with carnitine or acylcarnitine levels in neonatal blood. We identified a need to more fully investigate a potential interaction between gestational age and birth weight in regard to analyte levels. The secondary data analyses indicated a statistically significant relationship between analyte levels and all perinatal / infant and newborn screening related factors of interest, but effect sizes were generally small. The interaction between gestational age and birth weight was significant in all models; when further explored through graphical analysis with conditional means, extremely premature neonates stood out as having distinct analyte patterns in relation to birth weight. Variation in the ratio of total acylcarnitine to free carnitine was better accounted for by the perinatal and newborn factors than was variation in any individual carnitine or acylcarnitine, indicating that proportions of carnitine and acylcarnitines may be more important in understanding an individual’s metabolic functioning than individual analyte levels. A low proportion of variation was explained in all multivariate models, supporting the use of universal algorithms in newborn screening and suggesting the need for further large scale empirical research targeted at previously unaccounted for perinatal factors such as birth stress. newborn screening neonatal screening carnitine acylcarnitine mass screening inborn errors of metabolism lipid metabolism fatty acid oxidation fatty acid oxidation disorders free carnitine octanoylcarnitine C8 short chain acylcarnitine medium chain acylcarnitine long chain acylcarnitine birth weight gestational age sex age at collection age of collection blood spot heel prick socioeconomic status feeding breast milk formula transit time transfusion false positive Newborn Screening Ontario Ontario Newborn Screening Program database analysis systematic review
25	Odour signals relevant to beetles in deadwood habitats - odorants, olfaction and behaviour. / Duftstoffsignale bedeutend für Käfer in Totholzhabitaten - Duftstoffe, Wahrnehmung und Verhalten. Holighaus, Gerrit 27 April 2012 (has links) No description available. 570 Biowissenschaften Biologie WYP 550 Forest Sciences and Forest Ecology Xylobios Ambrosiakäfer Holzzersetzung Wirt Volatile Wirtserkennung VOC Holz GC-EAD EAG Mykophagie Hefe LOX Oxylipine C8 Cerambycidae Lymexylidae Tenebrionidae Scolytinae Polyporales saproxylic fungus-growing wood decay host non-host volatiles host recognition VOC wood assessment GC-EAD EAG fungivory yeast secondary pheromone component LOX oxylipin eight-carbon 42.99 Biologie: Sonstiges 42.75 Insecta: Entomologie 35.70 Biochemie: Chemische Ökologie
26	Characteristics Associated with Neonatal Carnitine Levels: A Systematic Review & Clinical Database Analysis Sutherland, Sarah C. 28 January 2013 (has links) Newborn screening programs measure analyte levels in neonatal blood spots to identify individuals at high risk of disease. Carnitine and acylcarnitine levels are primary markers used in the detection of fatty acid oxidation disorders. These analytes may be influenced by certain pre/perinatal or newborn screening related factors. The primary objective of this study was to explore the association between these characteristics and levels of blood carnitines and acylcarnitines in the newborn population. The study was composed of two parts: a systematic review and a clinical database analysis of existing newborn screening data. The systematic review results suggested considerable variability across studies in the presence and directionality of associations between analyte levels and birth weight, gestational age, age at time of blood spot collection, type of sample, and storage time. Sex was not significantly associated with carnitine or acylcarnitine levels in neonatal blood. We identified a need to more fully investigate a potential interaction between gestational age and birth weight in regard to analyte levels. The secondary data analyses indicated a statistically significant relationship between analyte levels and all perinatal / infant and newborn screening related factors of interest, but effect sizes were generally small. The interaction between gestational age and birth weight was significant in all models; when further explored through graphical analysis with conditional means, extremely premature neonates stood out as having distinct analyte patterns in relation to birth weight. Variation in the ratio of total acylcarnitine to free carnitine was better accounted for by the perinatal and newborn factors than was variation in any individual carnitine or acylcarnitine, indicating that proportions of carnitine and acylcarnitines may be more important in understanding an individual’s metabolic functioning than individual analyte levels. A low proportion of variation was explained in all multivariate models, supporting the use of universal algorithms in newborn screening and suggesting the need for further large scale empirical research targeted at previously unaccounted for perinatal factors such as birth stress. newborn screening neonatal screening carnitine acylcarnitine mass screening inborn errors of metabolism lipid metabolism fatty acid oxidation fatty acid oxidation disorders free carnitine octanoylcarnitine C8 short chain acylcarnitine medium chain acylcarnitine long chain acylcarnitine birth weight gestational age sex age at collection age of collection blood spot heel prick socioeconomic status feeding breast milk formula transit time transfusion false positive Newborn Screening Ontario Ontario Newborn Screening Program database analysis systematic review
27	Characteristics Associated with Neonatal Carnitine Levels: A Systematic Review & Clinical Database Analysis Sutherland, Sarah C. January 2013 (has links) Newborn screening programs measure analyte levels in neonatal blood spots to identify individuals at high risk of disease. Carnitine and acylcarnitine levels are primary markers used in the detection of fatty acid oxidation disorders. These analytes may be influenced by certain pre/perinatal or newborn screening related factors. The primary objective of this study was to explore the association between these characteristics and levels of blood carnitines and acylcarnitines in the newborn population. The study was composed of two parts: a systematic review and a clinical database analysis of existing newborn screening data. The systematic review results suggested considerable variability across studies in the presence and directionality of associations between analyte levels and birth weight, gestational age, age at time of blood spot collection, type of sample, and storage time. Sex was not significantly associated with carnitine or acylcarnitine levels in neonatal blood. We identified a need to more fully investigate a potential interaction between gestational age and birth weight in regard to analyte levels. The secondary data analyses indicated a statistically significant relationship between analyte levels and all perinatal / infant and newborn screening related factors of interest, but effect sizes were generally small. The interaction between gestational age and birth weight was significant in all models; when further explored through graphical analysis with conditional means, extremely premature neonates stood out as having distinct analyte patterns in relation to birth weight. Variation in the ratio of total acylcarnitine to free carnitine was better accounted for by the perinatal and newborn factors than was variation in any individual carnitine or acylcarnitine, indicating that proportions of carnitine and acylcarnitines may be more important in understanding an individual’s metabolic functioning than individual analyte levels. A low proportion of variation was explained in all multivariate models, supporting the use of universal algorithms in newborn screening and suggesting the need for further large scale empirical research targeted at previously unaccounted for perinatal factors such as birth stress. newborn screening neonatal screening carnitine acylcarnitine mass screening inborn errors of metabolism lipid metabolism fatty acid oxidation fatty acid oxidation disorders free carnitine octanoylcarnitine C8 short chain acylcarnitine medium chain acylcarnitine long chain acylcarnitine birth weight gestational age sex age at collection age of collection blood spot heel prick socioeconomic status feeding breast milk formula transit time transfusion false positive Newborn Screening Ontario Ontario Newborn Screening Program database analysis systematic review

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