published_or_final_version / Zoology / Master / Master of Philosophy

The collapse of buildings and infrastructure is an unfortunate consequence of major earthquakes (e.g., the 1964 Alaskan earthquake, the 1995 Kobe earthquake in Japan and the 2007 Pisco earthquake in Peru). Liquefaction-induced lateral spreading is known to be one cause of severe damage to deep foundation systems. However, the dynamic soil-structure interaction between liquefied soil and piles is extremely complex and further work is required to define the appropriate design pressures and to understand the mechanisms at work. This thesis presents the findings of an experimental program carried out using the large geotechnical centrifuge at C-CORE in St John’s Newfoundland, to investigate the mechanism of lateral spreading and its implications for dynamic soil-pile interaction. Soil and pile responses were measured using accelerometers, pore pressure transducers, and digital imaging using a high speed camera. Using these images, transient profiles of slope deformation were quantitatively measured using Particle Image Velocimetry (PIV). These tests illustrate the potential for earthquake shaking to excite the natural frequency of the liquefied soil column, which can lead to increased transient lateral pressures on piles in liquefiable ground. This study recommends that this potential for “auto tuning” should be anticipated in design and proposes a new limiting pseudo-static backbone p-y curve for use in the design of piles subjected to lateral spreading ground deformation. / Thesis (Master, Civil Engineering) -- Queen's University, 2009-01-27 10:09:43.902

Piles are engineering structures which are subjected to axial and lateral loading. In this dissertation, pile load tests were performed on a full-scale fabricated pile to understand lateral pile responses under static and cyclic loading. The experiments were performed on a fabricated test pile at the Geo-Engineering Laboratory at Queen's University. Dry loose Olimag Synthetic Olivine sand was used as the test soil. Instrumentation including axial strain gauges, null sensors (earth pressure sensors) and string potentiometers were used to monitor pile responses throughout the tests. What differentiates the current study from previous investigations is direct measurements of lateral earth pressure on a test pile using those null sensors with conventional measurements of curvature and deformation. The null sensors of Talesnick (2005) have ‘infinite stiffness’ and calibration that is almost independent of the soil type, soil condition and stress history, qualities that make the sensor superior to other commercially available sensors. The initial pile response under static loading was examined. Previous laterally loaded pile test programs have utilized curvature measurements to infer moments, and differentiation of moments to determine lateral forces. Comparisons with the directly measured pressures confirmed the effectiveness of differentiated moments. To understand offshore structures, the behaviour of a pile subjected to cyclic loading is examined and explained by elastic soil response at low load levels and the progressive development of inelastic response at higher load levels. In addition, the loading condition (i.e. two-way versus one-way loading) was found to have a substantial effect on pile responses. The pressure distributions for two-way cyclic loading suggest that the lateral pressure is proportional to displacement with peak pressures near the ground surface during elastic responses. The peak lateral pressures move deeper towards the point of rotation with increasing cyclic loads to generate inelastic responses. However, the lateral pressure response is consistently inelastic for one-way loading. / Thesis (Master, Civil Engineering) -- Queen's University, 2014-05-02 20:29:56.489

Lateral diffusion of phospholipids is a process essential to membrane function, and can be measured by nuclear magnetic resonance (NMR). This project will use CODEX (Centerband-Only Detection of Exchange), the most highly-evolved NMR experiment combining magic angle spinning with exchange sensitivity, to measure lateral diffusion. 31P CODEX NMR measurements were performed on phospholipids in small unilamellar vesicles (SUV) in a high viscosity solution to slow the rotational tumbling of the SUV and minimize its influence on the CODEX decay. For SUV composed of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), alone or mixed with 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoglycerol (POPG) or cholesterol (CHOL), 31P CODEX spectra showed well-resolved resonances for POPC and POPG, with monoexponential decays for both, from which the correlation time for molecular motion could be extracted. The lateral diffusion coefficients were determined, and fell in the range of 1.0 - 3.3 x 10-12 m2s-1 at 10°C, which agree with established literature values for POPC and POPG.

Lateral diffusion of phospholipids is a process essential to membrane function, and can be measured by nuclear magnetic resonance (NMR). This project will use CODEX (Centerband-Only Detection of Exchange), the most highly-evolved NMR experiment combining magic angle spinning with exchange sensitivity, to measure lateral diffusion. 31P CODEX NMR measurements were performed on phospholipids in small unilamellar vesicles (SUV) in a high viscosity solution to slow the rotational tumbling of the SUV and minimize its influence on the CODEX decay. For SUV composed of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), alone or mixed with 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoglycerol (POPG) or cholesterol (CHOL), 31P CODEX spectra showed well-resolved resonances for POPC and POPG, with monoexponential decays for both, from which the correlation time for molecular motion could be extracted. The lateral diffusion coefficients were determined, and fell in the range of 1.0 - 3.3 x 10-12 m2s-1 at 10°C, which agree with established literature values for POPC and POPG.

Amyotrophic lateral sclerosis (ALS) is a progressive and fatal motor neuron disease of unclear aetiology, although the general consensus is of a multifactorial disease. The kynurenine pathway (KP), activated during neuroinflammation, is emerging as a possible contributory factor in ALS. The KP is the major route for tryptophan (TRP) catabolism. The intermediates generated can be either neurotoxic, such as quinolinic acid (QUIN), or neuroprotective, such as picolinic acid (PIC), an important endogenous metal chelator. The first and inducible enzyme is indoleamine 2,3-dioxygenase (IDO). As the extent of the involvement of the KP in ALS is unknown, the main aim of this thesis was to attempt to answer that question. The techniques used in this work include HPLC, GC/MS, RT-PCR, immunohistochemistry and immunocyctochemsitry. The main findings of this project are: (1) the complete KP is present in the mouse motor neuron cell line, NSC-34; (2) QUIN toxicity on NSC-34 cells may be ameliorated through the administration of NMDA antagonists, neuroprotective kynurenines, kynurenine inhibitor and QUIN monoclonal antibody; (3) in ALS patients, QUIN CSF and serum levels are significantly elevated, while PIC serum levels are significantly reduced; (4) ALS brain and spinal cord tissue show extensive microglia activation and positive immunoreactivity IDO and QUIN in spinal motor neurons and Betz cells in the motor cortex; and (5) kynurenine pathway inhibitor and analogue, R061-8048 and tranilast, are able to prolong the survival in the G93A SOD1 ALS transgenic mouse model. In conclusion, this study provide the first strong evidence for the involvement of the KP in ALS, and these data point to an inflammation-driven excitotoxic-chelation defective mechanism in ALS, which is amenable to KP analogue and inhibitor in ALS transgenic mice.

Diss. (sammanfattning) Umeå : Univ., 2005. / Härtill 5 uppsatser.

Diss. (sammanfattning) Uppsala : Univ., 2004. / Härtill 5 uppsatser.

Thesis (Ph.D.)--University of Nebraska-Lincoln, 2008. / Title from title screen (site viewed Mar. 10, 2009). PDF text: xvi, 170 p. : ill. (some col.) ; 2 Mb. UMI publication number: AAT 3331437. Includes bibliographical references. Also available in microfilm and microfiche formats.

Thesis (M.S.)--Florida State University, 2004. / Advisor: Dr. Richard Hyson, Florida State University, College of Arts and Sciences, Dept. of Psychology. Title and description from dissertation home page (viewed Jan. 19, 2005). Includes bibliographical references.