Is socioeconomic position early in life associated with physical activity during adulthood following the accumulation of risk model with additive effects?

L'activité physique améliore la santé, mais seulement 4.8% des Canadiens atteignent le niveau recommandé. La position socio-économique est un des déterminants de l'activité physique les plus importants. Elle est associée à l’activité physique de manière transversale à l’adolescence et à l’âge adulte. Cette thèse a tenté de déterminer s'il y a une association à long terme entre la position socio-économique au début du parcours de vie et l’activité physique à l’âge adulte. S'il y en avait une, un deuxième objectif était de déterminer quel modèle théorique en épidémiologie des parcours de vie décrivait le mieux sa forme. Cette thèse comprend trois articles: une recension systématique et deux recherches originales. Dans la recension systématique, des recherches ont été faites dans Medline et EMBASE pour trouver les études ayant mesuré la position socio-économique avant l'âge de 18 ans et l'activité physique à ≥18 ans. Dans les deux recherches originales, la modélisation par équations structurelles a été utilisée pour comparer trois modèles alternatifs en épidémiologie des parcours de vie: le modèle d’accumulation de risque avec effets additifs, le modèle d’accumulation de risque avec effet déclenché et le modèle de période critique. Ces modèles ont été comparés dans deux cohortes prospectives représentatives à l'échelle nationale: la 1970 British birth cohort (n=16,571; première recherche) et l’Enquête longitudinale nationale sur les enfants et les jeunes (n=16,903; deuxième recherche). Dans la recension systématique, 10 619 articles ont été passés en revue par deux chercheurs indépendants et 42 ont été retenus. Pour le résultat «activité physique» (tous types et mesures confondus), une association significative avec la position socio-économique durant l’enfance fut trouvée dans 26/42 études (61,9%). Quand seulement l’activité physique durant les loisirs a été considérée, une association significative fut trouvée dans 21/31 études (67,7%). Dans un sous-échantillon de 21 études ayant une méthodologie plus forte, les proportions d’études ayant trouvé une association furent plus hautes : 15/21 (71,4%) pour tous les types et toutes les mesures d’activité physique et 12/15 (80%) pour l’activité physique de loisir seulement. Dans notre première recherche originale sur les données de la British birth cohort, pour la classe sociale, nous avons trouvé que le modèle d’accumulation de risque avec effets additifs s’est ajusté le mieux chez les hommes et les femmes pour l’activité physique de loisir, au travail et durant les transports. Dans notre deuxième recherche originale sur les données canadiennes sur l'activité physique de loisir, nous avons trouvé que chez les hommes, le modèle de période critique s’est ajusté le mieux aux données pour le niveau d’éducation et le revenu, alors que chez les femmes, le modèle d’accumulation de risque avec effets additifs s’est ajusté le mieux pour le revenu, tandis que le niveau d’éducation ne s’est ajusté à aucun des modèles testés. En conclusion, notre recension systématique indique que la position socio-économique au début du parcours de vie est associée à la pratique d'activité physique à l'âge adulte. Les résultats de nos deux recherches originales suggèrent un patron d’associations le mieux représenté par le modèle d’accumulation de risque avec effets additifs.

Structural features in ODP Holes 128-794D and 128-799B

Numerous structural features occur in the Leg 128 cores from the Japan Sea. They include (1) gravity-induced structures such as slump folds, (2) dewatering structures comprising several sets of veins, and (3) larger faults and veins developed in the volcanic basement of the Yamato Basin as well as in the sedimentary rocks of the Oki Ridge and Kita-Yamato Trough. Gravity-induced structures, mainly slumps and associated faults, suggest the existence of paleoslopes and the dominance of gravitational tectonics during the early and middle Miocene, at the Pliocene/Pleistocene boundary, and during the Quaternary. Several types of mud-filled veins having various shapes were observed. These are especially abundant in the middle Miocene siliceous claystones and porcellanites from the Kita-Yamato Trough. They have been interpreted as dewatering conduits that formed preferentially in highly porous, water-saturated diatomaceous muds on a slope, because of episodic loss of sediment strength, collapse of the sediment framework, and consequent fluid migration. The central part of the vein serves once as a fluid conduit, whereas the transition between conduit-controlled and intergranular flow occurs at the branching extremities, with concentration of fines. The likely trigger responsible for the strength loss is seismic activity. Development of these veins, spatially and chronologically linked to small normal microfaults, implies an extensional regime having layer-parallel extension and a local bedding-parallel shear couple, probably the result of gravitational gliding. The brittle fractures found in Yamato Basin basement Hole 794D cores comprise joints, faults, and veins filled with chlorite-saponite, saponite, and calcite. They suggest a likely transpressive to transtensional regime around the early Miocene/ middle Miocene boundary, with a north-northeast-south-southwest compression alternating with a west-northwest-eastsoutheast extension. The faults from Site 799 cores on the Yamato Rise exhibit a prominent early Miocene-middle Miocene extensional environment, a late Miocene-early Pliocene phase of normal and strike-slip faulting, and a final phase that began during the latest Pliocene. Site 798, on the Oki Ridge, reveals faults that recorded a consistent extensional tectonic regime from Pliocene to the Holocene. These data support the pull-apart kinematic model for early Miocene-middle Miocene time, as regarding the stress regime deduced from the Yamato Basin basement fractures. The recent compression known in the eastern margin of the Japan Sea was not documented by compressive structures at any site. The late Miocene-early Pliocene faulting phase corresponds to a major and general reorganization of the stress distribution in the arc area. Evidence for rapid and main subsidence and synsedimentary extension of the Yamato Basin and Yamato Rise areas between 20 and 15 Ma, and the concomitant rotation of southwest Japan, raise the question of links between this opening and the Shimanto Belt collision in southwest Japan, between the arc and the Philippine Sea Plate.

Rear end structural crashworthiness of perimeter frame vehicles. Summary report. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

Rear end structural crashworthiness of perimeter frame vehicles, design development and verification. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

Rear end structural crashworthiness of unitized construction vehicles - summary report. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

Seismically-Induced Rock-Slope Failure: Numerical Investigation using the Bonded Particle Model

Thesis (Ph.D.)--University of Washington, 2016-06

Nonparametric Identication and Structural Estimation of Auction Models

Thesis (Ph.D.)--University of Washington, 2016-06

Quantum transport and integrability of the Anderson model for a quantum dot with multiple leads

We show that an Anderson Hamiltonian describing a quantum dot connected to multiple leads is integrable. A general expression for the nonlinear conductance is obtained by combining the Bethe ansatz exact solution with Landauer-Buttiker theory. In the Kondo regime, a closed form expression is given for the matrix conductance at zero temperature and when all the leads are close to the symmetric point. A bias-induced splitting of the Kondo resonance is possible for three or more leads. Specifically, for N leads, with each at a different chemical potential, there can be N-1 Kondo peaks in the conductance.

Structural Insights into Viral Membrane Fusion Machinery via Cryo-Electron Tomography: Influenza Virus and Human Parainfluenza Virus

Thesis (Ph.D.)--University of Washington, 2016-06

Dynamical properties of a strongly correlated model for quarter-filled layered organic molecular crystals

The dynamical properties of an extended Hubbard model, which is relevant to quarter-filled layered organic molecular crystals, are analyzed. We have computed the dynamical charge correlation function, spectral density, and optical conductivity using Lanczos diagonalization and large-N techniques. As the ratio of the nearest-neighbor Coulomb repulsion, V, to the hopping integral, t, increases there is a transition from a metallic phase to a charge-ordered phase. Dynamical properties close to the ordering transition are found to differ from the ones expected in a conventional metal. Large-N calculations display an enhancement of spectral weight at low frequencies as the system is driven closer to the charge-ordering transition in agreement with Lanczos calculations. As V is increased the charge correlation function displays a collective mode which, for wave vectors close to (pi,pi), increases in amplitude and softens as the charge-ordering transition is approached. We propose that inelastic x-ray scattering be used to detect this mode. Large-N calculations predict superconductivity with d(xy) symmetry close to the ordering transition. We find that this is consistent with Lanczos diagonalization calculations, on lattices of 20 sites, which find that the binding energy of two holes becomes negative close to the charge-ordering transition.

Modelling the input-output behaviour of piezoelectric structural health monitoring systems for composite plates

This paper investigates the input-output characteristics of structural health monitoring systems for composite plates based on permanently attached piezoelectric transmitter and sensor elements. Using dynamic piezoelectricity theory and a multiple integral transform method to describe the propagating and scattered flexural waves an electro-mechanical model for simulating the voltage input-output transfer function for circular piezoelectric transmitters and sensors adhesively attached to an orthotropic composite plate is developed. The method enables the characterization of all three physical processes, i.e. wave generation, wave propagation and wave reception. The influence of transducer, plate and attached electrical circuit characteristics on the voltage output behaviour of the system is examined through numerical calculations, both in frequency and the time domain. The results show that the input-output behaviour of the system is not properly predicted by the transducers' properties alone. Coupling effects between the transducers and the tested structure have to be taken into account, and adding backing materials to the piezoelectric elements can significantly improve the sensitivity of the system. It is shown that in order to achieve maximum sensitivity, particular piezoelectric transmitters and sensors need to be designed according to the structure to be monitored and the specific frequency regime of interest.

Molecular analysis of the pathway for the synthesis of thiol tripeptides in the model legume Lotus japonicus

The thiol tripeptides, glutathione (GSH) and homoglutathione (hGSH), perform multiple roles in legumes, including protection against toxicity of free radicals and heavy metals. The three genes involved in the synthesis of GSH and hGSH in the model legume, Lotus japonicus, have been fully characterized and appear to be present as single copies in the genome. The gamma-glutamylcysteine synthetase (gammaecs) gene was mapped on the long arm of chromosome 4 (70.0 centimorgans [cM]) and consists of 15 exons, whereas the glutathione synthetase (gshs) and homoglutathione synthetase (hgshs) genes were mapped on the long arm of chromosome 1 (81.3 cM) and found to be arranged in tandem, with a separation of approximately 8 kb. Both genes consist of 12 exons of exactly the same size (except exon 1, which is similar). Two types of transcripts were detected for the gshs gene, which putatively encode proteins localized in the plastids and cytosol. Promoter regions contain cis-acting regulatory elements that may be involved in the plant's response to light, hormones, and stress. Determination of transcript levels, enzyme activities, and thiol contents in nodules, roots, and leaves revealed that gammaecs and hgshs are expressed in all three plant organs, whereas gshs is significantly functional only in nodules. This strongly suggests an important role of GSH in the rhizobia-legume symbiosis.

Structural studies of copper(II)-amine terminated dendrimer complexes by EXAFS

The three-dimensional branched nature of dendritic macromolecules provides many potential sites per molecule for the complexation of metal ions. Therefore, dendrimers may act as hosts for metals with coordination potentially occurring at the periphery, the interior, or both. To understand further the complexation of dendrimers with metal ions EXAFS experiments were carried out. In this work, the interaction of amine-terminated polyamido(amine), PAMAM, dendrimer with copper(II) ions determined by EXAFS is reported. It was found that a model consisting of the copper(II) ion forming five- and six-membered rings by chelating with the primary amine, amide, and tertiary amine nitrogen donors of the PAMAM dendrimer could describe the experimental EXAFS data well. Corroborative evidence for binding to amide nitrogen donors comes from the broadening of NMR resonances of a copper(Il)-PAMAM mixture revealing the presence of paramagnetic copper(II) ions at these sites. The significance of the results presented in this paper is that copper(II) ions form complexes within the dendrimer structure and not just at the periphery. The current study may have implications for the use of PAMAM dendrimers as effective ligands in sensing systems.

Permeability studies of alkylamides and caffeic acid conjugates from echinacea using a Caco-2 cell monolayer model

Background: Echinacea is composed of three major groups of compounds that are thought to be responsible for stimulation of the immune system-the caffeic acid conjugates, alkylamides and polysaccharides. This study has focussed on the former two classes, as these are the constituents found in ethanolic liquid extracts. Objective: To investigate the absorption of these two groups of compounds using Caco-2 monolayers, which are a model of the intestinal epithelial barrier. Results: The caffeic acid conjugates (caftaric acid, echinacoside and cichoric acid) permeated poorly through the Caco-2 monolayers although one potential metabolite, cinnamic acid, diffused readily with an apparent permeability (P-app) of 1x10(-4) cm/s. Alkylamides were found to diffuse through Caco-2 monolayers with P-app ranging from 3x10(-6) to 3x10(-4) cm/s. This diversity in P-app for the different alkylamides correlates to structural variations, with saturation and N-terminal methylation contributing to decreases in P-app. The transport of the alkylamides is not affected by the presence of other constituents and the results for synthetic alkylamides were in line with those for the alkylamides in the echinacea preparation. Conclusion: Alkylamides but not caffeic acid conjugates are likely to cross the intestinal barrier.

Crystal structure of P450cin in a complex with its substrate, 1,8-cineole, a close structural homologue to D-camphor, the substrate for P450cam

Cytochrome P450cin catalyzes the monooxygenation of 1,8-cineole, which is structurally very similar to D-camphor, the substrate for the most thoroughly investigated cytochrome P450, cytochrome P450cam. Both 1,8-cineole and D-camphor are C-10 monoterpenes containing a single oxygen atom with very similar molecular volumes. The cytochrome P450cin-substrate complex crystal structure has been solved to 1.7 Angstrom resolution and compared with that of cytochrome P450cam. Despite the similarity in substrates, the active site of cytochrome P450cin is substantially different from that of cytochrome P450cam in that the B' helix, essential for substrate binding in many cytochrome P450s including cytochrome P450cam, is replaced by an ordered loop that results in substantial changes in active site topography. In addition, cytochrome P450cin does not have the conserved threonine, Thr252 in cytochrome P450cam, which is generally considered as an integral part of the proton shuttle machinery required for oxygen activation. Instead, the analogous residue in cytochrome P450cin is Asn242, which provides the only direct protein H-bonding interaction with the substrate. Cytochrome P450cin uses a flavodoxin-like redox partner to reduce the heme iron rather than the more traditional ferredoxin-like Fe2S2 redox partner used by cytochrome P450cam and many other bacterial P450s. It thus might be expected that the redox partner docking site of cytochrome P450cin would resemble that of cytochrome P450BM3, which also uses a flavodoxin-like redox partner. Nevertheless, the putative docking site topography more closely resembles cytochrome P450cam than cytochrome P450BM3.