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Articles 91 - 114 of 114
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Spatial And Deterministic Limits On Randomness, Matthew Davison
Spatial And Deterministic Limits On Randomness, Matthew Davison
Digitized Theses
The concept of Gaussian white noise has been very valuable in the application of stochastic differential equations to problems ranging from physics to finance. White noise has links with the diffusion equation, the solution of which gives the density of random walkers on a Euclidean space.;The use of white noise is not always appropriate in the study of random processes. In this thesis a new family of noise processes is defined. These "fractal walk" noise processes have connections with a "diffusion" equation in which the order {dollar}\gamma{dollar} of the time derivative takes on a continuous range of values between 0 …
Modulation Of Experimental Allergic Encephalomyelitis In The Sjl/J Mice By Cytokines And Anti-Cytokine Antibodies, Trang Thi Duong
Modulation Of Experimental Allergic Encephalomyelitis In The Sjl/J Mice By Cytokines And Anti-Cytokine Antibodies, Trang Thi Duong
Digitized Theses
Immunization with myelin basic protein in complete Freund's adjuvant resulted in only mild chronic-relapsing experimental allergic encephalomyelitis (EAE) with very low incidence in SJL/J mice, and no disease at all in A/J, BALB/c, C3H/HeJ, DBA/2, AKR and NZW mice. However, treatment of mice with anti-IFN{dollar}\gamma{dollar} (aIFN) monoclonal antibody (mAb) at the time of immunization determined severe disease in all those strains except AKR. Similarly, the passive induction of EAE in the SJL/J mice and in two of three resistant strains examined was significantly enhanced by aIFN mAb administration. In the SJL/J mice, administration of anti-interleukin 2 (aIL2) mAb had only …
Spectroscopic Properties Of Copper Binding To The Protein Metallothionein, Anna Rae Green
Spectroscopic Properties Of Copper Binding To The Protein Metallothionein, Anna Rae Green
Digitized Theses
Metallothionein (MT) is a low molecular weight protein found in the kidneys and livers of all mammals. Twenty of its 61 or 62 amino acid residues are cysteinyl residues, allowing the protein to act as an impressive chelating agent. Although it has been well established that mammalian MT binds seven M(II) (M = Cd(II), Zn(II), Hg(II)) ions tetrahedrally in two metal-thiolate clusters of the form M{dollar}\sb4{dollar}(S{dollar}\rm\sb{lcub}cys{rcub})\sb{lcub}11{rcub},{dollar} (the {dollar}\alpha{dollar} domain) and {dollar}\rm M\sb3(S\sb{lcub}cys{rcub})\sb9,{dollar} (the {dollar}\beta{dollar} domain), little is known about the structure of copper-containing metallothioneins. In this thesis, absorption, circular dichroism (CD) and emission spectroscopies and excited state lifetime data are …
Structural Studies On Silver(I) Metallothionein, Ziqi Gui
Structural Studies On Silver(I) Metallothionein, Ziqi Gui
Digitized Theses
Metallothioneins (MT) are a class of low molecular weight, cysteine rich proteins in almost all living things. These proteins have been found to bind a wide range of metals both in vivo and in vitro due to the unusually high cysteinyl sulfur content. The metallothioneins are believed to possess the ability to store and transport essential metals, such as Zn(II) and Cu(I), and also to detoxify toxic metals, such as Cd(II) and Hg(II). However, the precise physiological functions of these proteins still remain unclear to date. As silver(I)-metallothioneins have shown different stoichiometric ratios of Ag:MT from Zn(II)- and Cd(II)-metallothioneins in …
The Mineralogy And Inorganic Geochemistry Of Coal And Combustion Products From The Mae Moh Mine, Thailand: Environmental Implications Of Resource Utilization, Brian R. Hart
Digitized Theses
The coals, associated sediments and combustion products, from the Tertiary, Mae Moh Lignite Mine Lampang, Thailand, have been investigated using XRD, XRF, NAA and SEM/EDS. The investigation is primary aimed at documenting the overall mineralogy and geochemistry of the coal and combustion products, in an attempt to briefly describe the local environmental impacts of resource utilization.;Ash content in composite run of mine samples in three important (J, K and Q) coal zones averages 44%. Ash in the power plant feed coal averages 41%. Dominant mineral phases in the zones include: detrital quartz, illite and kaolinite along with authigenic calcite and …
Using Model Systems To Study Rat Lens Membrane Damage During Cortical Cataract Formation, Fusun Kilic
Using Model Systems To Study Rat Lens Membrane Damage During Cortical Cataract Formation, Fusun Kilic
Digitized Theses
Cataract formation is a complex, multifactorial and multistep process: it is associated with cellular and biochemical changes in the lens. In the present work, steps in the pathway to cataract development were followed in vitro using two different reagents which induce cataract formation by two different mechanisms: elevated glucose (55.6 mM), as a model for in vivo diabetic cataractogenesis and an actin monomer-stabilizer, cytochalasin D (10{dollar}\sp{lcub}-5{rcub}{dollar} M, CD). Findings were utilized to classify and arrange the events in a common pathway and to focus on the mechanism of cataract production.;The development of cortical subcapsular opacity in cultured lenses was elucidated …
Evolutionary Dynamics At Two Loci Of The Human Genome As Assessed By Examination Of Nucleotide Sequence Diversity And Organization, Kathleen Allen Hill
Evolutionary Dynamics At Two Loci Of The Human Genome As Assessed By Examination Of Nucleotide Sequence Diversity And Organization, Kathleen Allen Hill
Digitized Theses
Accurate and comprehensive measurement of the extent and pattern of nucleotide diversity is necessary to refine theories on the dynamics of evolution. It is possible to determine the sequence of any genomic region for numerous individuals using the polymerase chain reaction (PCR) and associated techniques of DNA sequence analysis. The two regions of the human genome examined in this study were the third exon of the highly conserved (two major alleles) alcohol dehydrogenase, Adh2 locus and the second exon of the highly polymorphic (26 alleles) human leukocyte antigen, HLA-DQ{dollar}\beta{dollar}1 gene. Sequence information was determined from 25 individuals from Southwestern Ontario …
Depression And Vulnerability: The Role Of Mood And Depression History On Cognitive Processing, Scott Bradley Mccabe
Depression And Vulnerability: The Role Of Mood And Depression History On Cognitive Processing, Scott Bradley Mccabe
Digitized Theses
Cognitive theorists hypothesize the existence of a causal cognitive vulnerability for depression that exists as either a continuously observable trait-like difference (i.e., the main-effects model) or a latent factor observable only in interaction with life events or mood (i.e., the interaction effects model). The current investigation examined the main-effects model and one form of the interaction-effects model that emphasizes current mood as the activator of latent cognitive vulnerability, the Differential Activation Hypothesis (DAH). When primed by sad mood, vulnerable individuals purportedly process environmental information in a manner similar to currently depressed individuals, making them more vulnerable for depression.;Studies of cognition …
A Logic For Object-Oriented Databases, Machmudin Junus
A Logic For Object-Oriented Databases, Machmudin Junus
Digitized Theses
When E. F. Codd {dollar}\lbrack{dollar}Codd70{dollar}\rbrack{dollar} designed relational databases, he made use of mathematical logic concerning Predicate Calculus. However, when object-oriented databases were designed, there was no such support from any established mathematical logic.;In this thesis, we present a logic suitable for reasoning about object-oriented database systems. This logic is the result of the modification of F-logic {dollar}\lbrack{dollar}KifLa89, KifLaWu90{dollar}\rbrack.{dollar} The main difference between our proposed logic and F-logic, is the way our logic treats class objects and instance objects.;Our designed logic has the ability to represent: object identities, attributes, methods, classes, class hierarchies and inheritance. Similar to F-logic, the designed logic …
Visualization And Analysis Of Multiple Sclerosis Lesions In Magnetic Resonance Images, J Ross Mitchell
Visualization And Analysis Of Multiple Sclerosis Lesions In Magnetic Resonance Images, J Ross Mitchell
Digitized Theses
Magnetic Resonance Imaging (MRI) provides very sensitive indication of the presence and extent of the lesions of Multiple Sclerosis (MS). As a result, quantifying changes in the number and extent of lesions in MR images has been used to indicate disease activity in clinical trials of new therapies. However, lesion quantification is long, arduous, and subject to variability between and within operators. These factors limit the application of quantitative techniques and increase the duration, and thus cost, of clinical trials which rely on their measurements to assess therapeutic effect.;A computerised system was developed for assisted 3-D quantification and analysis of …
Prenatal Risk Factors For Neurological Abnormalities In The Term And Near Term Neonate, Kathleen Owen O'Connor
Prenatal Risk Factors For Neurological Abnormalities In The Term And Near Term Neonate, Kathleen Owen O'Connor
Digitized Theses
An abnormal neurological examination in the neonatal hospital stay may indicate a transient or permanent neurological disturbance. Abnormal neurological symptoms therefore place an infant at increased risk for subsequent neurological problems.;This case-control study was designed to investigate prenatal and perinatal risk factors for an abnormal neurological examination in the term infant. Infants were born between 1 January, 1988 and 30 June, 1990. The sample consisted of 222 neonates with neurological abnormalities and 666 controls who were free of such problems. Data on the prenatal histories of their mothers, course of the pregnancy, intrapartum events and status of the infant after …
Developmental Potential Of Rat Myoblast Lineages, Christopher Louis Pin
Developmental Potential Of Rat Myoblast Lineages, Christopher Louis Pin
Digitized Theses
Skeletal muscle consists of multinucleated fibres which are classified as slow (I) or fast (IIA, IIB, IIX) muscle fibre types which differ in their contractile properties and their expression of contractile protein isoforms. Individual muscles contain characteristic distributions of fibre types which can be identified based on their myosin heavy chain (MyHC) content. While classical studies have demonstrated that the fibre type composition of adult muscles can be altered by extrinsic factors (such as changes in the pattern of innervation), recent studies suggest that different fibre types may be formed from distinct myoblast lineages. The purpose of this study was …
High Resolution And Wideline Nmr Studies Of Membrane Associated Molecules Involved In Signal Transduction, Alan Cavell Rigy
High Resolution And Wideline Nmr Studies Of Membrane Associated Molecules Involved In Signal Transduction, Alan Cavell Rigy
Digitized Theses
The primary focus of our investigations were centered around understanding the biochemical basis of the early events involved in signal transduction. Our work has involved two novel systems: (1) sphingolipid metabolites and (2) a synthetic peptide representing the transmembrane region of the human epidermal growth factor receptor (hEGFR).;Sphingolipid metabolites have emerged as physical modulators of many signalling pathways, including cell growth regulation, and signal transduction. N,N-({dollar}\sp2{dollar}H{dollar}\sb6{dollar}) -dimethylsphingosine and ({dollar}\sp2{dollar}H{dollar}\sb4{dollar}) -lysogalactosyl ceramide were produced by partial synthesis and studied via wideline {dollar}\sp2{dollar}H NMR, as a function of pH. Spectra of ({dollar}\sp2{dollar}H{dollar}\sb6{dollar}) -dimethylsphingosine identified that the molecule's orientation and behaviour are largely …
Epidermal Growth Factor Regulation Of Porcine Oocyte Maturation And Cumulus Cell Expansion In Vitro, Balwant Singh
Epidermal Growth Factor Regulation Of Porcine Oocyte Maturation And Cumulus Cell Expansion In Vitro, Balwant Singh
Digitized Theses
The overall objective of this study was to investigate the role in vitro of epidermal growth factor (EGF) in the regulation of both nuclear and cytoplasmic maturation of the porcine oocyte, and in the expansion of cumulus cells.;Studies aimed at the induction of oocyte maturation and cumulus expansion revealed that EGF is a potent stimulant of the resumption of meiosis in the oocyte and that the addition of FSH, but not LH, to EGF further enhances its effect on germinal vesicle breakdown (GVBD). Both estradiol-17{dollar}\beta{dollar} (E{dollar}\sb2{dollar}) and androstenedione (A{dollar}\sb4{dollar}) inhibited FSH-stimulated GVBD, but had no effect on EGF-stimulated GVBD, suggesting …
Feedback Control Mechanisms Regulating Breathing In Humans, Croix Claudette St
Feedback Control Mechanisms Regulating Breathing In Humans, Croix Claudette St
Digitized Theses
The respiratory system regulates alveolar ventilation (V{dollar}\sb{lcub}\rm A{rcub}{dollar}) almost exactly to the demands of the body so that the PCO{dollar}\sb2{dollar} and PO{dollar}\sb2{dollar} of the arterial blood are hardly altered, even during strenuous exercise or other types of respiratory stress. The feedback control of ventilation was studied in human subjects using the technique of dynamic end-tidal forcings to produce perturbations in end-tidal PCO{dollar}\sb2{dollar} (P{dollar}\sb{lcub}\rm ET{rcub}{dollar}CO{dollar}\sb2{dollar}) and end-tidal PO{dollar}\sb2{dollar} (P{dollar}\sb{lcub}\rm ET{rcub}{dollar}O{dollar}\sb2{dollar}) to stimulate the respiratory chemoreceptors.;The purpose of the first study was to investigate the interaction between ventilatory drives from the central (cR{dollar}\sb{lcub}\rm c{rcub}{dollar}) and peripheral (pR{dollar}\sb{lcub}\rm c{rcub}{dollar}) chemoreceptors using their different …
Compositional Analysis Of Gate Dielectric Films, Hongtao Tang
Compositional Analysis Of Gate Dielectric Films, Hongtao Tang
Digitized Theses
Oxynitride has recently drawn attention as a candidate gate dielectric material for deep sub-micron devices, e.g. MOSFET's. Since the oxide growth rates in pure oxygen are high, efforts to scale down device dimensions with high quality ultrathin ({dollar}<{dollar}100A) SiO{dollar}\sb2{dollar} films are encountering some difficulties. Recently, it has been found that oxynitride films fabricated directly by a N{dollar}\sb2{dollar}O-rapid thermal processing method exhibit improved electrical properties compared to SiO{dollar}\sb2{dollar} films. Structural analysis for such oxynitride films is necessary in order to understand the physical reasons behind the observed improvements.;Nuclear reaction analysis combined with a chemical step-etching method was performed to depth profile nitrogen quantitatively in N{dollar}\sb2{dollar}O-RTP grown oxynitride films. The oxynitride dielectric composition dependence on growth conditions in a rapid thermal processing system was also investigated by nuclear reaction analysis. It is found that most N in the oxynitride films accumulates in a region close to the interface (less than 25 A from the interface in the oxynitride). Both N concentration and film thickness increase with temperature. Furthermore, a UHV initial growth study of oxynitride films on a Si(100) substrate was carried out by nuclear reaction analysis and Auger electron spectroscopy. The results clearly confirm that the nitrogen involvement occurs primarily before an oxynitride film thickness of {dollar}\sim{dollar}25 A is developed, and the subsequent film growth is dominated by oxidation. For the first time, it is found that there is a special growth period at the very beginning during which nitridation (with no simultaneous oxidation) dominates the growth process. It is speculated that the phenomenon results from a competition between reactions of Si with O and N. The dependence of film growth on temperature is such that below 950{dollar}\sp\circ{dollar}C, there is little nitrogen incorporated in the oxide film.
Traits, Situations, And Managerial Behaviour: Test Of A Trait Activation Hypothesis, Robert Preston Tett
Traits, Situations, And Managerial Behaviour: Test Of A Trait Activation Hypothesis, Robert Preston Tett
Digitized Theses
Results supporting the predictive validity of assessment centres (e.g., Gaugler, Rosenthal, Thornton & Bentson, 1987) are at odds with widely reported findings that behavioural consistency among assessment centre exercises is low (e.g., Sackett & Dreher, 1982). Lack of behavioural consistency raises doubts as to how assessment centres work. Drawing from principles of person-situation interactionism, a trait activation hypothesis is proposed to help explain the conflicting findings and direct development of valid simulation exercises. The hypothesis holds that the behavioural expression of a trait requires arousal of that trait by trait-relevant situational cues. Cross-situational consistency in behaviour is thereby conceived to …
Finite Element Analysis Of Geometrically Nonlinear Laminated Composite Shell Structures, Bin Wang
Finite Element Analysis Of Geometrically Nonlinear Laminated Composite Shell Structures, Bin Wang
Digitized Theses
This thesis is concerned with static and dynamic analysis of linear and geometrically nonlinear laminated composite plate and shell structures by using the finite element method.;The emphasis has been on establishing a sound theoretical basis for the formulation of simple and efficient finite elements for large scale linear and geometrically nonlinear analysis of laminated composite plate and shell structures.;A series of simple three-node, six degree-of-freedom (DOF) per node, hybrid strain based flat laminated composite triangular shell finite elements (HLCTS) for linear analysis were developed. These elements were based on the degenerated three dimensional solid concept. The first order shear deformation …
Using The Quantum Mechanical Path Integral In Quantum Field Theory, Siu Kwan Wong
Using The Quantum Mechanical Path Integral In Quantum Field Theory, Siu Kwan Wong
Digitized Theses
Matrix elements of the form {dollar}\langle x\vert\exp({lcub}-{rcub}iHt)\vert y\rangle{dollar} arise when operator regularization, a symmetry-preserving regulating procedure that avoids explicit occurrence of divergences, is employed to do perturbative calculations in quantum field theory. In recent years, it is shown that this matrix element can be evaluated using a path integral encountered in single particle quantum mechanics. This technique has the advantage of eliminating loop momentum integrals and algebraically complicated vertices in gauge theories. We develop this technique to handle various problems. Our approach is similar to but distinct from the one of Polyakov and Strassler which is related to the string …
The In Vitro Studies On Phage Mu Transposase, Zhenguo Wu
The In Vitro Studies On Phage Mu Transposase, Zhenguo Wu
Digitized Theses
Bacteriophage Mu is one of the model systems to study DNA transposition. The availability of an in vitro soluble system greatly facilitates the dissection of the transposition mechanisms at the molecular levels. Several aspects of the in vitro mini-Mu DNA transposition have been dealt with in this thesis.;First, the flanking host DNA sequences on the strand cleavage step mediated by Mu transposase (Mu A protein) was investigated. We found that certain flanking host sequences could inhibit the strand cleavage step without affecting the earlier synapsis step. Furthermore, this cleavage defect could be overcome by the Mu B protein in the …
Chemistry Of Antiwear Films By X-Ray Absorption Spectroscopy, Zhanfeng Yin
Chemistry Of Antiwear Films By X-Ray Absorption Spectroscopy, Zhanfeng Yin
Digitized Theses
The antiwear and antioxidant additives, zinc dialkyldithiophosphates (ZDDPs), are an essential ingredient in engine oil formulations, and have been in use for many years. These additives function by forming antiwear films on surfaces in sliding contact, and thus reduce friction and wear. Among the surface techniques employed, X-ray absorption spectroscopy (including EXAFS and XANES) has been mainly used because of its high resolution, low detection limit and non-destructive characteristics.;This is the first time that P and S L-edge XANES spectroscopy has been used to analyze antiwear films and thermal films. About two hundred antiwear films and thermally prepared films have …
The Effects Of Preadministration Of Nmda Antagonists On Kindling With Carbachol, Deborah Michelle Saucier
The Effects Of Preadministration Of Nmda Antagonists On Kindling With Carbachol, Deborah Michelle Saucier
Digitized Theses
This thesis evaluated the hypothesis that N-methyl-D-aspartate (NMDA) receptor activity is essential for the development of kindling and/or the maintenance of the kindled state in male hooded rats. Kindling was produced by the infusion of carbachol, a muscarinic cholinergic agonist, directly into either the basolateral nucleus of the amygdala or the dentate gyrus of the hippocampus. The infusions of carbachol took place over 70 seconds and were given every 2 days. At a previously determined time before the infusion of carbachol, either APV (DL-aminophosphonovaleric acid, infused into the site of recording) or NPC 17742 (2R,4R,2S-(2-amino-4,5(cyclohexyl)-7-phosphonoheptanoic acid, i.p.) was given. Both …
Sustainability And Canada's National Parks: Suitability For Policy, Planning And Management, Stephen William Boyd
Sustainability And Canada's National Parks: Suitability For Policy, Planning And Management, Stephen William Boyd
Digitized Theses
As a term, sustainability has often come to be adopted as the 'panacea' for many problems without any clear understanding that the solutions will vary given the nature of the problem, the scale involved and the goals and objectives set out. As a result, what has emerged in the literature has been many different 'pictures' of sustainability, all of which may be relevant in certain contexts. This research examined the potential of the concept within the context of Canadian national parks. Emphasis was directed toward understanding, through the perceptions of 'expert' groups knowledgeable about parks, the key elements needed to …
Intramolecular Aldol Condensation Reactions And Transacetalization Equilibria, Junan Guo
Intramolecular Aldol Condensation Reactions And Transacetalization Equilibria, Junan Guo
Digitized Theses
Part I. Intramolecular aldol condensation reactions. The detailed kinetics and equilibrium for the intramolecular aldol condensation reaction of 2,5-hexanedione, 2, 6-heptanedione, 1-phenyl-1, 5-hexanedione and 5-oxohexanal were studied and correlated in terms of Marcus theory. All the reactions, with the readily explained exception of the intramolecular aldol addition of 5-oxohexanal, gave us approximately constant intrinsic barriers: 14.49 {dollar}\pm{dollar} 0.82 kcal/mol for the intramolecular aldol addition step and 13.99 {dollar}\pm{dollar} 0.74 kcal/mol for the subsequent dehydration step, which are also in excellent agreement with the intrinsic barriers found for intermolecular aldol condensation reactions.{dollar}\sp{lcub}16{rcub}{dollar} This means that Marcus theory is applicable to intramolecular …