title: Chromosome Aberrations in Mouse Spermatocytes and Oocytes Exposed to 300R ϒ-Radiation: A Comparison

contributor:
Uchida, Irene A.
Medical Sciences

subject:
Medical Sciences
Medical Sciences

abstract:
It has been repeatedly demonstrated that radiation induces chromosome aberrations in mouse oocytes and spermatocytes. However, the results of previous studies, in which the frequency of aberrations recovered from irradiated oocytes and spermatocytes were compared, are conflicting (reviewed by L. B. Russell, 1962, L. B. Russell, 1968). The development of new techniques for making chromosome preparations from oocytes (Edwards, 1965; Tarkowski, 1966) and spermatocytes (Evans et al., 1964) has made it possible to reinvestigate the radiosensitivities of spermatocytes and oocytes.

In the present study, the frequency of chromosome aberrations recovered from irradiated dictyotene oocytes was compared to the frequencies of aberrations recovered from irradiated pachytene and diplotene spermatocytes.

Oocytes and spermatocytes were collected from mature mice one day and five days after exposure to a single acute dose of 300R ϒ-radiation. At the time of irradiation, all of the oocytes were in dictyotene while the spermatocytes collected one day and five days post-irradiation were in diplotene and pachytene, respectively. The average number of oocytes collected from irradiated mice was no different from the average number collected from controls. Although the ability of oocytes collected one day post-irradiation to mature in vitro (58.0%) was not affected, significantly fewer (53.6%) of the oocytes cultured five days post-irradiation matured in vitro. Since the frequency of abnormal cells vas the same in oocytes cultured one day and five days post-irradiation, it is unlikely that oocytes with chromosome aberrations were selectively inhibited from maturing in vitro.

The frequencies of chromosome aberrations in dictyate oocytes cultured one day and five days after irradiation were not significantly different from the frequency of aberrations in diplotene spermatocytes (20.7%). However, significantly more chromosome aberrations (32.0%) were recovered fraa irradiated pachytene spermatocytes than from either dictyate oocytes or diplotene spermatocytes. Some variation in the relative frequencies of aberrations was found.

abstract: Master of Science (MS)


title: Bi-Axial Testing of Zinc and Zinc Alloy Sheets under Superimposed Hydrostatic Pressures

contributor:
Sowerby, R.
Production

subject: Management Sciences and Quantitative Methods

abstract:
The effects of pressurization on the properties of metals has long been of interest to scientists. Bridgman found that in general, the ductility (ability of the metal to deform without fracture) increased with superimposed hydrostatic pressure. Pugh et al. confirmed similar findings.

The effects of hydrostatistic pressure on the mechanical properties of thin anisotropic zinc, heat treated and non heat treated zinc alloy sheets subjected to biaxial tension (via the circular bulge test) is investigated in this project.

A brief look is taken into the generalized conditions for the onset of tensile plastic instability in a thin circular diaphragm bulged under superimposed hydrostatic pressure. The material is assumed to obey Hill's theory of yielding for anisotropic materials. These predictions are verified by conducting bulge tests using back pressures up to 10,000 psi. It is concluded that within the pressure range of investigation there is no detectable changes in the properties of the materials tested.

In the appendix section a brief look is taken into the microstructure of the materials tested.

abstract: Master of Engineering (ME)


title: Programming Language 2100 and its Compiler HPCOM

contributor:
Solntseff, N.
Computation

subject:
Computational Engineering
Computational Engineering

abstract:
This report contains a description of the programming language PL/2100, which is a procedure oriented, block structured language with an extensive set of operators, including arithmetic, relational, logical, bit manipulation and shift operators. It is designed for writing PL/2100 programs that conform to the standard of structured programming and for efficiently expressing and implementing algorithms written in it.

This report, also, contains a description of the one-pass working compiler (HPCOM) (for PL/2100) written for the HP/2100A minicomputer.

abstract: Master of Science (MS)


title: The role of Q-banding in the cytogenetic study of human spontaneous abortions

contributor:
Carr, D.H.
Medical Sciences

subject:
Medical Sciences
Medical Sciences

abstract:
The discovery of Q-banding made it possible to identify every member of the human chromosome complement. Spontaneous abortions known to have a better than average chance of presenting with a chromosome anomaly were selected for cytogenetic analysis. A highly successful technique for culturing chorion from these specimens was developed. Direct chromosome preparations were obtained from the coverglasses on which the fibroblasts were subcultured. The characteristics of each specimen were noted as that as the information pool gives, it may be possible to define abortion syndromes.

Fifty-nine per cent of the specimens selected were abnormal. These abnormalities included trisomies 2, 8, 14, 16 and 22, triploidy and tetraploidy. Vesicular villi, maternal age over 40 and conception coincident with maternal ingestion of contraceptives were found to be excellent forcasters of chromosome anomalies. Only one embryo, 69, XXY, in which congenital malformations could be identified was collected during the duration of this project. A possible polymorphism in a non-heterochromatic region of chromosome 17, in a 16-trisomy specimen, was noted.

Heteromorphic bands have made it possible to distinguish between the members of a homologous pair of chromosomes 3, 4, 13, 14, 15, 21 and 22. A study of such markers in a twin abortus allowed for speculation on the zygosity of the embryos. Similar polymorphisms were used to determine whether the extra set of chromosomes in two triploid abortuses was of maternal or maternal origin. Distribution of these marker chromosomes was also used to determine when in meiosis the event of abnormal development occurred. The point was stressed, that some cell-to-cell variability does occur in these heteromorphic Q-bands and that great care must be taken in distinguishing maternal and paternal marker chromosomes, before the distribution of these parental chromosomes can be used to make statements about abnormal development events.

Heteromorphic bands have made it possible to distinguish between the members of a homologous pair of chromosomes 3, 4, 13, 14, 15, 21 and 22. A study of such markers in a twin abortus allowed for speculation on the zygosity of the embryos. Similar polymorphisms were used to determine whether the extra set of chromosomes in two triploid abortuses was of maternal or paternal origin. Distribution of these marker chromosomes was also used to determine when in meiosis the event of abnormal development occurred. The point was stressed, that some cell-to-cell variability does occur in these heteromorphic Q-bands and that great care must be taken in distinguishing maternal and paternal marker chromosomes, before the distribution of these parental chromosomes can be used to make statements about abnormal developmental events.

abstract: Master of Science (MS)


title: Development of Harmonic Excitation technique for Machine Tool stability analysis

contributor:
Tlusty, J.
Production

abstract:
The project described in this thesis was to establish the instrumentation and technique for analysing stability of machine-tools against chatter by harmonic excitation. To test out the technique, two sets of experiments were performed on centre lathes:

1) comparison of cutting stability with tour different types of boring bars, and

2) comparison of cutting stability of a tool oriented in seven orientations in a single plane perpendicular to the spindle axis.

The electro-dynamic exciter was used in 1) while an electro-magnetic exciter was used in 2) Data of the excitation tests were used to compute and plot the cross-receptances which indicate the limit width of cut together with the chatter frequency and the modal shapes which identify the main masses and springs of the structure. The contribution of the individual modes to the resulting degree of stability can also be obtained. Cutting tests were conducted to provide some means of checking the reliability of the excitation test results. In this report also included are the theory of vibration, theory of chatter and specification of various parts of instrumentation.

abstract: Master of Engineering (ME)


title: Compliance of Medical Outpatients with Prescribed Medication: A Protocol for a Controlled Trial of Clinical Intervention

contributor:
Sackett, D.L.
Medical Sciences

subject:
Medical Sciences
Medical Sciences

abstract:
Lack of compliance with therapeutic regimens is an important cause of inadequate or incomplete medical care.

For the purposes of furthering knowledge about problems of compliance, this thesis first surveys issues of compliance as reported in the current scientific literature and then proceeds with the development of specific strategies to improve compliance and finally with the development of a research design for testing these strategies in a controlled clinical fashion among a cohort of medical patients newly initiated into therapy.

The compliance-intervention strategies include, first, special techniques in patient education, utilizing potent behavior-oriented teaching materials, second, a flexible, opportunistic approach to fitting medical appointments and medication-taking into a patient's existing rituals and daily routine, a process here termed "tailoring", and, third, a behavior modification paradigm which reinforces prescribed behavior.

Hypertension has been chosen as a disease appropriate for the testing of the strategies because of its high prevalence and its known harmful effects, because of tho existence of efficacious treatments for it, and because of the small proportion of its victims who are receiving adequate treatment, whether for lack of detection of the condition or lack of compliance with its therapy.

A steel mill (Dominion Foundries and Steel Company) in Hamilton, Ontario, has been selected as an ideal study site for several reasons. First, the Company is owned by its employees and this has led to an exceptionally stable employee group. Second, it has an active and cooperative employee health service. Thirdly, the health service staff has become concerned about the problem of untreated hypertension through its periodic health assessment program and the high prevalence of hypertension among employees lost from active duty through vascular disease.

At the time of this writing the project has been funded through the Medical Research Council and is just getting underway.

abstract: Doctor of Philosophy (PhD)


title: Modelling two-phase flow-excited fluidelastic instability in heat exchanger tube arrays

contributor:
Judd, R.L.
Weaver, D.S.
Mechanical Engineering

subject:
Mechanical Engineering
Mechanical Engineering

abstract: This thesis reports on the investigation of flow induced vibration in heat exchanger tube arrays. This work is in support of nuclear steam generator design, where attention is focussed on the tubes in the upper U-bend region which are subjected to cross-flow, and are therefore most susceptible to the destructive effects of flow-induced vibration. Results for this study are reported for a dynamically scaled model tube array in a parallel triangular layout, with a pitch over diameter ratio of P/D = 1.44, mounted in a clamped-free arrangement. This tube bundle was subjected to single and two-phase cross-flows of refrigerant R-11. The main motivation of this work is to present experimental results on fluidelastic instability, the mechanism that usually causes the most damaging vibrations, and to make comparisons with other data on the basis of non-dimensional similitude parameters to determine the effect of using different fluid mixtures to simulate the actual steam-water flow in the steam generator. A new method is proposed for calculating the average fluid density and equivalent flow velocity of the two-phase fluid, using a newly developed void fraction model which accounts for the difference in velocity between the gas and liquid phases. The fluidelastic data of several researchers, who used a variety of fluids, is re-examined using this new void fraction model and the results show a remarkable difference in trend between two common flow regimes, bubbly and intermittent flow. The latest flow regime map, developed by other researchers for predicting the two-phase flow regimes in the shell-side cross-flows in tube bundles, was applied to the fluidelastic results. This analysis showed that the sudden change in stability behavior which appeared in various data sets were directly related to a predicted change in flow regime from bubbly to intermittent flow. The two-fluid model used in the fluidelastic data analysis was developed by the present author from experimental measurements of void fraction in the horizontal tube bundle using the gamma densitometer. Measurements of the damping effect of two-phase flows were obtained in the present study and are presented and compared with previous data using an existing analysis technique. Damping measurements showed that the tube damping peaks at about 75% to 80% HEM void fraction, and decreases at lower and especially higher void fraction. The turbulence buffeting response of the tubes was measured and from this the non-dimensional spectrum of turbulent forces was determined and compared with existing data. In single phase flow, the data of the present study appears to plot higher than the extensive data points of Taylor et al. (1996), but are mostly within the upper bound determined by Taylor and Pettigrew (1999). In two-phase flow, the turbulent forces were analysed according to the new data reduction method of deLangre and Villard (1998). (Abstract shortened by UMI.)

abstract: Doctor of Philosophy (PhD)


title: Improvement of processes and product quality through multivariate data analysis

contributor:
MacGregor, John F.
Kourti, Theodora
Chemical Engineering

subject:
Chemical Engineering
Chemical Engineering

abstract: This thesis focuses on developing empirical methodologies for improving process operation and product quality, in four important chemical engineering problems, using multivariate projection methods, such as Principal Component Analysis (PCA) and Projection to Latent Structures (PLS). The four problems addressed in this work are concerned with (i) improving and optimizing the trajectories of manipulated variables in batch processes; (ii) improving the identification of non-parsimonious dynamic process models using the Jackknife and the Bootstrap methods; (iii) developing meaningful specification regions for raw materials entering a consumer's plant and, (iv) improving transition policies in start-ups, re-starts and grade changeovers that are routinely performed in multi-product plants. The first problem addresses the situation where one desires to gain understanding of how and when, during the course of a batch, manipulated process variables have a significant effect on product quality. This amounts to estimating the sensitivity of product quality to manipulated process variables at various degrees of completion in a batch process. This information can be used in process development and in the optimization of already existing processes. The proposed approach involves adding designed experiments to batch policies currently used and then analyzing the resulting data bases using multi-way multi-block PLS. A new pathway PLS algorithm was developed for incorporating intermediate quality measurements collected during the course of each batch. In the second problem, the identification of non-parsimonious dynamic process models is improved through a more judicious selection of the meta parameter in regularization methods (ridge regression) and latent variable methods. These methods are often used to overcome ill-conditioning frequently encountered in the identification of such over-parameterized models. A new criterion for selecting the meta parameter (ridge parameter in regularization methods and the number of components in latent variable methods) is proposed, based on Jackknife and Bootstrap statistics. It is shown that this criterion outperforms the use of cross-validation (default criterion) and leads to the identification of models that are closer to the true process behavior. Developing an approach for defining multivariate specifications on incoming raw materials was important because there is a void in the quality control literature in this area. Specifications are usually defined in a univariate manner, based on past and often subjective experience. This work provides a sound, data-based approach for developing truly multivariate specification regions in a variety of industrial situations. The approach uses PLS methods to analyze historical data on the incoming raw materials, on the consumer's plant, and on the consumer's end product to define multivariate specification regions for the incoming raw material properties. The last problem consists of improving the performance of process transitions (start-ups, re-starts and grade changeovers), using historical process data. In particular, this work addresses two questions: (i) how to improve transition policies to minimize transition time and amount of off-grade materials, while ensuring safe operating conditions and (ii) how to ensure that at the end of a transition, steady-state process conditions are such that good quality products are obtained, and are consistent with past periods of production.

abstract: Doctor of Philosophy (PhD)


title: Women and computer science: Alternative routes to computing careers

contributor:
Fox, J.
Sociology

subject: Sociology Sociology

abstract: Women's proportional representation in university Computer Science (CS) programs in Canada has been declining. This study set out to (1) provide a clear picture of the recent research into women and computing education and work; (2) develop a model based on past research and the theoretical perspectives of dual-systems theory, social closure, and social control; (3) assess the impact of social controls on women's education and work choices through interviews with computer workers; and (4) compare the trends in computer education and work over time. This study finds support for theories of social closure and control: interviews show that, over time, factors vary in their influences on women's computing career choices. The increasing status of computing work, the broadening applications of computing, the growing shortage of workers, and the narrow entry into CS affect beliefs about computing. Respondents' belief in myths that computing careers involve very little human interaction, and that women lack the kind of curiosity required of a computer scientist, stopped many from entering CS. The encouragement of mathematics teachers, and gaining computer-related experiences positively influence women to study computing. The alternative route to computing through a non-technical job shows that gaining computer experience even in the workplace can influence women making career choices. Women's proportions are increasing in non-university computer education as women's proportions in CS have been declining. Women taking alternative routes to computing careers tend to work in the less technical occupations, and are segregated by sex within high technology industries. They are more likely to work part-time, are clustered in lower paying specialties, and earn less income than men. The income gap is small and narrowing for women with high computer skills. Despite the benefits of high skill computer work, women are increasingly preparing themselves for medium and lower skill computing work through non-university education.

abstract: Doctor of Philosophy (PhD)


title: Eric Voegelin and the Schelling Renaissance: The Schellingian orientation in Voegelin's later works (1952--1985)

contributor:
Planinc, Zdravko
Kroeker, Travis P.
Clark, David
Religious Studies

subject: Religion Religion

abstract: This dissertation compares the philosophy of Friedrich Wilhelm Joseph von Schelling (1775-1854) and Eric Voegelin (1901-1985). More specifically, it discusses the considerable extent to which Voegelin drew upon Schelling in the formulation of his mature philosophy of consciousness and its supporting historiography. There are three parts to the presentation of my argument. First, I consider why Voegelin's published references to Schelling varied greatly throughout the course of his career. Secondly, I consider the earliest of Voegelin's major works, examining the extent to which they draw upon Schelling's. Initially, Voegelin thought of Schelling as a philosopher who managed to transcend the intellectual extremes of his time--idealism and nihilism--and Voegelin attempted to follow his example. Finally, I discuss how Voegelin distributed aspects of Schelling's post-idealist thought in his own mature works on the philosophy of consciousness and its progressive differentiation in history. I conclude by offering a number of critical reflections on Voegelin's Schellingian view of history as a theogonic process of being itself which tends toward the "immortalizing" transfiguration of humanity

abstract: Doctor of Philosophy (PhD)


title: The genetic dissection of Neu-mediated transformation

contributor:
Muller, William J.
Biology

subject: Biology Biology

abstract: The ErbB-2/Neu receptor tyrosine kinase (RTK) plays a causal role in mammary tumourígenesis in a significant proportion of women, yet mechanistically does so in ill defined manner. The carboxy-terminus of the receptor, containing several phosphotyrosine residues, is thought to mediate transformation through interactions with cytoplasmic SH2/PTB-containing signaling molecules. To assess the role of each tyrosine phosphorylation site in cellular transformation, I created and analysed several series of phosphorylation mutants. While mutation of individual sites (Y1028, Y1144, Y1201, Y1226/7, Y1253) had little effect on neu -mediated transformation, the simultaneous mutation of each known Neu autophosphorylation site rendered the receptor transformation impaired. I assessed the role of each tyrosine phosphorylation site in cellular transformation, by restoring individual tyrosine residues to this transformation debilitated neu mutant. Reversion of any one of four mutated sites (Y1144, Y1201, Y1226/7, Y1253) restored wild-type transforming activity. These transforming "add-back" mutants displayed Ras-dependent signaling, which was further correlated with the ability of two of these "add-back" mutants to bind either the GRB2 (to Y1144) or SHC (to Y1227) adaptor molecules known to couple RTKs to Ras. Microinjection experiments suggest that Y1144 and Y1227 mediate Grb2 dependent and independent signals respectively. Additionally, several proteins were found to interact with the terminal phosphorylation site (Y1253) and using finer mutagenesis, transformation from Y1253 was correlated with the binding of an unknown 34kDa protein. By contrast, restoration of tyrosine 1028 to transforming add-back mutants suppressed the transformation. Mechanistically transformation repression correlated with a reduction in the ability to bind She and Grb2. As decreased Grb2 association was reversible by protein tyrosine phosphatase (PTP) inhibition, these data suggest that tyrosine 1028 acts to decrease transformation, in part, through the activation of PTPs. I used a RT-PCR approach to isolate PTPs expressed in the mammary gland to identify PTPs relevant in Neu signaling. One candidate, Shp-1, is overexpressed in mammary tumours and epithelial cells derived thereof and inhibits Neu-mediated transformation genetically upstream of Ras. These data argue not only that the transformation by activated neu is mediated primarily through Ras by multiple signaling proteins and is regulated in a negative manner by the Shp-1 PTP, but it also provides much insight in rational drug targets for ErbB-2-mediated human diseases.

abstract: Doctor of Philosophy (PhD)


title: The effects of mutagenesis on the reactive centre loop of two thrombin-inhibitory serpins, antithrombin and heparin cofactor II

contributor:
Sheffield, W.P.
Medical Sciences

subject:
Medical Sciences
Medical Sciences

abstract: Antithrombin (AT) and heparin cofactor II (HCII) are the predominant inhibitors of thrombin in plasma. They belong to the se rine p[barbelow]rotease in hibitor, or serpin, family of proteins and they inhibit their target proteases through a mechanism that is unique to this family of molecules. AT and HCII provide an ideal substrate on the reactive centre loop and subsequently form 1:1 stoichiometric inhibitory complexes with their target proteases through a mechanism that results in major conformational changes in these serpins. While thrombin acts as a target protease with these serpins, neutrophil elastase (NE), another serine proteases, reacts with AT and HCII within the reactive centre loop. Unlike thrombin, however, the interaction of NE with AT and HCII results in cleavage and inactivation of these serpins, without forming inhibitory complexes with NE. The aim of this thesis was to analyze the effects of mutagenesis of the NE cleavage sites within AT and HCII to determine the limits of amino acid substitutions that would permit AT and HCII to retain function but be less susceptible to inactivation by NE. Analyses of proteins expressed in a cell-free expression system and then in COS-1 mammalian cell culture were used to study the effects of mutagenesis at P4 and then at P4 and P5 in rabbit and human AT. While charged and polar amino acid substitutions severely reduced the function of AT, substitution of the bulkiest residue, tryptophan, at P4 and then at P5 and P5 had minimal effects on the thrombin-inhibitory activity of AT. However, the susceptibility to NE cleavage did not appear to be affected by any substitutions that were made in AT. Analysis of amino acid substitutions in bacterially-derived HCII P6 variants demonstrated a similar flexibility in amino acid composition at the site of NE cleavage, with respect to the ability to inhibit thrombin, although substitution of polar and bulky residues within the reactive centre loop of this serpin increased its resistance to NE inactivation. These results demonstrate that the amino acid composition of the reactive centre loop of AT and HCII is flexible to allow the maintenance of thrombin-inhibitory activity, although some limitations do exist. The effects of residue substitutions within the reactive centre loop on the susceptibility to NE cleavage are less clear, but the presence of bulky amino acids at the primary NE cleavage site, at least in HCII, appears to reduce the proteolytic activity of this protease. The production of an NE-resistant thrombininhibitory serpin provides the basis for the possible development of "hardened serpins" which might be of therapeutic importance in the future.

abstract: Doctor of Philosophy (PhD)


title: Identification of the effects of proline-leucine-glycine-NH(2) (PLG) on D(2)-dopamine receptor function and gene expression in the rat brain

contributor:
Mishra, R.K.
Medical Sciences

subject:
Medical Sciences
Medical Sciences

abstract: Central dopaminergic systems have been implicated in CNS disorders such as schizophrenia and Parkinson's disease. The characteristics of dopamine (DA) receptors has been well studied using a variety of pharmacological and biochemical techniques. DA receptor function is known to be modulated by the endogenous tripeptide pro-leu-gly-NH2 (PLG). A combination of novel pharmacological (guanosine-5' -O -(3[ 35 S]thio)triphosphate; [35 S]GTPγS binding) and molecular biological (differential display mRNA by RT-PCR; ddPCR) techniques were used to examine the function of endogenously expressed D2 DA-receptors in the striatum. Studies were undertaken to increase our understanding of the mechanism of action of PLG and its role in D2 receptor regulation and signal transduction. Measurement of antagonist effects in the absence of D2 receptor stimulation revealed that basal [35 S]-GTPγS binding was significantly decreased by haloperidol, butaclamol and chlorpromazine but not clozapine, sulpiride and spiperone. Thus haloperidol, butaclamol and chlorpromazine acted as negative antagonists; while clozapine, sulpiride and spiperone acted as silent antagonists. The role of PLG in D2 receptor stimulation of Gi G-proteins was examined using the [35 S]-GTPγS binding technique. The possible effect of PLG on NPA-stimulated [35 S]GTPγS binding was assessed at both maximal (1 μM NPA) and submaximal (0.1 and 0.03 μM NPA) levels of D2 receptor stimulation. It was found that PLG did not significantly alter [35 S]-GTPγS binding in bovine striatum either in the absence or presence of D2 receptor stimulation; indicating that PLG does not alter the rate of GDP:GTP exchange in the Giα G-protein subunit. Haloperidol and clozapine have distinct pharmacological profiles and have differential effects on many systems in the brain. This likely accounts for the tendency toward the development of extra pyramidal side effects (EPS) with the use of haloperidol but not clozapine. In an attempt to elucidate the mechanism of action of PLG, ddPCR was utilised to discover genes that are regulated by protracted treatment with PLG (20 mg/kg, i.p. for 28 days). In the present study, I have attempted to further the understanding of D2 receptor coupling to G-proteins in the striatum with respect to agonist efficacy and negative versus silent antagonism. I have also determined that PLG does not modulate D2 receptor signal transduction by altering the rate of GDP:GTP exchange in Gi. Furthermore, I have used the [35 S]-GTPγS binding technique to compare the effects of typical and atypical neuroleptic treatment on D2 receptor coupling to Gi. (Abstract shortened by UMI.)

abstract: Doctor of Philosophy (PhD)


title: Autonomy and Beneficence: Striking a Balance in Alzheimer's Disease

contributor:
Thomas, J.E.
Philosophy

subject: Philosophy Philosophy

abstract:
Alzheimer's Disease research is troubled by ethical problems in respect to the research design, subject selection and obtaining a valid consent. In the thesis, these ethical issues are examined with particular attention being paid to the question of whether Alzheimer's Disease patients can be involved in research offering no promise of benefits to these vulnerable subjects.

Drawing from both deontological and consequentialist ethical theories, a resolution of some of the ethical issues is proposed. Although many Alzheimer patients are no longer autonomous, they do continue to have moral worth and therefore, should be respected by society. Also, the requirement of competency for consent to be a research subject is explored and a more demanding standard of competency to consent to research participation is recommended.

The ethical tension in Alzheimer's Disease is not confined to balancing respect for the subject's autonomy with the need to learn more about this devastating disease but also, involves balancing the need to respect and protect a vulnerable population while supporting research striving to reduce the human and economic costs of Alzheimer's Disease. The proposed resolution of this ethical tension is based on a reevaluation of the requirements for an ethical design and a valid consent in the context of Alzheimer's Disease.

Recommendations on the conduct of Alzheimer's Disease are proposed which can be integrated into current research guidelines. These recommendations may also be of assistance to researchers working with other vulnerable patients.

Respect for weak and vulnerable subjects is the ethical priority and serves to restrict some types of Alzheimer's Disease. However, it is proposed that Alzheimer's Disease patients may be involved in clinical research not likely to benefit them directly, and is not expected to harm the subject on condition that the proposed, stringent rules regarding their participation are followed.

abstract: Doctor of Philosophy (PhD)


title: Magnetic Properties of Frustrated Pyrochlore Antiferromagnets

contributor:
Greedan, J.E.
Chemistry

subject: Chemistry Chemistry

abstract:
The magnetic properties of polycrystalline samples of pyrochlore antiferromagnets were investigated. The metal atoms in pyrochlores form a 3 dimensional network of comer sharing tetrahedra. Antiferromagnetic ordering is frustrated on such a lattice in the sense that all nearest neighbor microscopic interactions cannot be simultaneously satisfied. A number of experimental (Neutron diffraction, magnetic susceptibility and heat capacity) and theoretical techniques (mean field theory and Monte Carlo simulations) have been used to investigate the magnetic propenies of this interesting lattice.

Considerable experimental evidence was consistent with spin glass behavior which is unusual for chemically ordered materials. All of the compounds investigated showed dramatic irreversibilities in the magnetic susceptibility data. A few of the materials (FeF₃, Nd₂Mo₂O₇ and Mn₂Sb₂O₇) were seen to exhibit long range order, which was complex in nature. Tb₂Mo₂O₇ and Y₂Mn₂O₇ showed no signs of magnetic ordering down to 7K but neutron scattering data indicated that strong short range correlations were present over a wide temperature range. Inelastic scattering for Tb₂Mo₂O₇ was consistent with some degree of spin freezing at 25K.

Mean field theory calculations predicted that no long range order would exist in pyrochlore antiferromagnets with only nearest neighbor interactions. Further neighbor interactions would in most cases stabilize complex long range magnetic order. Monte Carlo simulations showed that thermal fluctuations were insufficient to stabilize long range order in the absence of further neighbor interactions. Extensive simulations for a model with further neighbor interactions and long range order gave strong evidence for the existence of a new universality class in pyrochlore antiferromagnets. This result was supported by neutron scattering results for FeF₃.

abstract: Doctor of Philosophy (PhD)


title: Identity, History and the Athabaskan Potlatch

contributor:
Feit, Harvey
Anthropology

subject: Anthropology Anthropology

abstract: A basic theme underlying Athabaskan culture and the potlatch is the duality of competition and cooperation. In the literature on both the Northwest Coast and Athabaskan potlatch this duality is most often considered in one of two ways: as a cultural phenomenon which is functional and ahistorical in nature, or as a product of Native and White contact. In this study I take a less radical view. Within Athabaskan culture and the potlatch cooperation and competition exist in a historically reticulate duality which provides the internal dynamic in Northern Athabaskan culture and continues to motivate attempts to redefine the culture and the potlatch. In the context of political and economic domination, however, the duality becomes an opposition in which competition is submerged and reshaped into a symbol for the White man, while cooperation becomes a symbol for unity and Indianness. The resulting ideology, or "Indian way," becomes a critique of the current situation and a vision of things as they should be. The potlatch is the major arena in which this vision derived from the past is reproduced.

abstract: Doctor of Philosophy (PhD)


title: Putative Immunosuppressive Molecules Associated with In Vitro Fertilized Embryos may be Essential Growth Factors

contributor:
Clark, David A.
Medical Sciences

subject:
Medical Sciences
Medical Sciences

abstract:
There is a high rate of pregnancy failure in humans. The greatest loss occurs at the time of implantation or immediately after the embryo has implanted. Up to 50-60% of this loss can be attributed to embryonic chromosomal abnormalities. The absence or anomalous amounts of physiologic factors which are necessary for implantation and early embryonic development may be the cause of pregnancy failure. Since the embryo is foreign, it is specifically necessary to explore the role of rejection and failure of mechanisms that suppress rejection at implantation.

The murine system has been used to investigate the identity of immunosuppressive molecules produced during the process of preimplantation embryo development. Supernatants from mouse in vitro fertilized (IVF) embryo cultures can suppress in vitro lymphocyte proliferation stimulated by the mitogen concanavalin A. Medium conditioned by incubation with mouse epididymal spermatozoa alone were even more inhibitory to mitogen stimuhued lymphocyte proliferation. Thin layer chromatography detected the polyamines spermine in sperm, and spermidine as well as spermine in IVF embryo culture supernatants. Evidence was obtained that these were possibly the ill vitro molecules that were immunosuppressive and were likely produced by the embryo. The diamine putrescine was also detected but was not immunosuppressive.

The conclusion from the studies suggest that polyamines may have a role in vivo in suppressing uterine immune response thereby assisting the embryo in the process of implantation. Failure of embryos to produce sufficient amounts of polyamines perhaps due to chromosome abnormalities, may explain failure of embryo implantation. As well, the failure of IVF embryos to produce adequate quantities of polyamines which are known to be essential for cell proliferation, could lead to embryo division arrest. In this broad sense polyamines may be viewed as "growth factors" i.e. defined molecules essential for cell division.

abstract: Doctor of Philosophy (PhD)


title: The photochemistry of alkylcyclobutenes at 228-nm: An investigation of the Rydberg excited state reactivity

contributor:
Leigh, William J.
Chemistry

subject: Chemistry Chemistry

abstract: In apparent contradiction with the Woodward-Hoffmann rules of pericyclic reactions, the photochemical ring-opening of alkylcyclobutenes to 1,3-dienes has been shown to proceed nonstereospecifically. There is now substantial evidence to support a mechanism in which the reaction occurs adiabatically to produce the symmetry-allowed diene in the excited singlet state. Relaxation to the ground state provides the observed mixture of diene isomers. Although the ring-opening is presumed to occur from the π,π* excited state alone, the potential involvement of the low-lying Rydberg π,R(3s) has never been completely ruled out. In order to assess the contribution of the Rydberg state to the photochemistry of cyclobutenes, a series of 1,2-dialkyl substituted derivatives were irradiated at 228-nm where the π,R(3s) state can be excited selectively. Under these conditions, it was found that these cyclobutenes continue to give rise to ring-opening products in substantial yields. Furthermore, with cis - and trans -1,2,3,4-tetramethylcyclobutene, the reaction proceeds with conrotatory (thermal) stereospecificity. The possibility of reaction from upper vibrational levels of the ground state was investigated. The quantum yields for ring-opening at 228-nm for a series of cyclobutenes were determined, and compared to values calculated with the assumption that reaction proceeds entirely via a hot ground state mechanism. The calculated quantum yields were based on rate constants from RRKM theory and the rate of relaxation from upper vibrational levels of the ground state. Hot ground state reactivity was shown to be insignificant by the lack of any correlation between the experimental and calculated quantum yields. The ring-opening reaction from the Rydberg state was shown to be dependent on the incipient torsional mobility about the central C1-C2 bond of the cyclobutene. Derivatives with small ancillary rings attached to the central bond displayed reactivity similar to the π,π* state, where those with large ancillary rings gave products enriched in the conrotatory diene isomers. Both the π,π* (adiabatic) and Rydberg state ring-opening reactions can be rationalized in terms of these results. The pathway to ring-opening on the Rydberg state potential energy surface likely encounters a barrier associated with twisting about the central bond. If the barrier is sufficiently large, the state can cross with the π,π* surface and products of adiabatic ring-opening are formed. When there is free rotation about the central bond, conrotatory ring-opening from the Rydberg state occurs.

abstract: Doctor of Philosophy (PhD)


title: Hillslope hydrology and runoff processes in a subarctic, subalpine environment

contributor:
Woo, Ming-ko
Geography

subject: Geography Geography

abstract: Within the subalpine zone of a subarctic basin, hydrological processes were studied on four hillslopes within 5 km2 in an attempt to determine the factors that cause the variability in the magnitude and timing of water balance components. The hillslope was chosen as the scale of study as it links process operating at the point with streamflow, and exhibits strong contrasts in microclimate, vegetation, frost and soils, providing an ideal natural laboratory. Hillslopes showed strong asymmetry in the timing and magnitude of processes during the melt and summer period. On slopes with well drained soils and seasonal frost, vertical hydrological exchanges predominate over the entire year and slopes rarely contribute runoff for streamflow. In contrast, hillslopes underlain with permafrost and/or poorly drained soils with a capping organic layer produce strong lateral fluxes. Water balance information highlighted the principal factors that lead to differences in process magnitudes and timing. This information is important in understanding basin hydrology, as streamflow is a summation of lateral fluxes from slopes. The presence of ice-rich layers blocking soil interstices encourages runoff by restricting drainage. Runoff exhibits a two-layer flow system consisting of quickflow (pathways in the porous organic layer, pipes, rills, and interconnected depressions) and slowflow (pathways in underlying mineral soils and highly decomposed and compacted peat). Quickflow controls the shape and timing of the runoff hydrograph, which is influenced by properties of hillslope wetness and organic layer thickness. Recession analysis revealed variable source areas for runoff generation and highlighted the role of wetness-controlled hydrologic connectivity of a slope segment. Results from this thesis have implications for water resource inventories and predicting hydrologic behaviour of subarctic, subalpine hillslopes.

abstract: Doctor of Philosophy (PhD)


title: Aspects of settling in the activated sludge process

contributor:
Dold, P.L.
Civil Engineering

subject:
Civil Engineering
Civil Engineering

abstract: This study focuses on sludge settleability and SVI-type measures. Quantification of sludge settleability is crucial. This usually is done via empirical relationships. Parameters used in these relationships require measurement of sludge zone settling velocity in column settling tests over a wide range of concentrations. Due to the extensive experimental effort involved, several alternative measures (e.g. SVI, DSVI, SSVI) have gained favour for monitoring sludge settleability at full-scale treatment facilities. There is considerable debate over which SVI-type measure is best. The study also includes a section on one-dimensional settling tank models. These models often are incorporated into wastewater treatment process simulators. Many of the one-dimensional settling tank models proposed to date are plagued by numerical instability and solution problems. Background for this thesis is provided in Chapter 2. Included in this section is background on settling tests used to quantify the effect of suspended solids concentration on sludge settling velocity. Chapter 2 also provides background on the development of secondary settling tank modelling. The main body of this thesis is presented as a series of four papers. The first paper (Chapter 3) addresses the considerable confusion which exists as to the best SVI-type parameter and experimental technique to use. A simple mechanistic model was developed and used to evaluate the effects of biosolids characteristics and test parameters on SVI-type indices. The model explains many of the artifacts associated with SVI and questions the validity of correlations for zone settling parameters based on SVI-type measures. The second paper (Chapter 4) examines the approach of correlating SVI-type measures with zone settling velocity (ZSV) parameters for use in flux theory analysis (design or operating charts). Correlations were assessed using the model developed in Chapter 3. The results show that use of the correlations may lead to erroneous results. The third paper (Chapter 5) presents experimental data to demonstrate that differences in column height and sludge concentration can lead to large differences in calculated SVI for a given sludge. The model developed in Chapter 3 was used to further highlight these potential problems and evaluate the effects of sludge characteristics and test parameters on SVI-type indices. The paper raises considerable doubt regarding the validity of correlations for zone settling parameters based on SVI-type measures. An alternative SVI-based method was proposed for determining zone settling parameters. The fourth paper (Chapter 6) outlines the approaches commonly used in one-dimensional layered secondary settling tank models. Two cases were examined: steady-state for a continuous flow secondary settling tank, and unsteady-state for a batch settling test. These cases were used as a basis to provide a rational explanation of numerical solution and stability problems that historically have plagued the one-dimensional layered modelling approach. The results show that the approach of introducing flux constraints into one-dimensional models should be avoided.

abstract: Doctor of Philosophy (PhD)


title: Partitioning the electron number, pair and transition densities of silanes: An atoms in molecules study of the properties of silicon compounds

contributor:
Bader, Richard F. W.
Chemistry

subject: Chemistry Chemistry

abstract: The field of silicon chemistry has proven to be an ever-expanding subject of interest in both the academic and industrial fields. A large portion of this work involves computational and theoretical studies of electronic structure. These studies use Molecular Orbital theory to obtain results which closely correspond with experiment. It is not enough, however, to know the properties of the molecule as a whole, frequently, important insights can be gained by understanding the contribution of an atom in that molecule to those total properties. While invaluable for computing the properties of an entire molecule, molecular orbitals contain no information about individual atoms, requiring the development of arbitrary mathematical treatments that partition the molecular orbitals according to their basis function expansions. The theory of Atoms in Molecules removes the need for arbitrary models by partitioning the molecular properties on the basis of the topology of the electron density, a method based on established quantum mechanical principles. This work began with a detailed analysis of the bonding and atomic properties of simple compounds containing silicon, with the analogous carbon compounds used as a comparison. This initial study illustrated why silicon species react the way they do, and how the electronic differences between silicon and carbon species result in differences in chemical properties. This work also studied the localization of electron density in silicon compounds using the pair density to further illustrate the nature of silicon's electronic structure. The focus of the study then shifted to oligosilanes, known to undergo strong electronic excitations that experience a bathochromic shift with increased chain length. Attempts to determine the nature of this so-called σ-conjugation made use of the electron and pair density properties, and finally the transition density, which allows one to partition the probability of excitation into its atomic contributions.

abstract: Doctor of Philosophy (PhD)


title: Thermal error modelling and compensation for a coordinate measuring machine

contributor:
Elbestawi, M. A.
Spence, A. D.
Mechanical Engineering

abstract: A methodology for quasi-static error correction by compensation for an intrinsic Coordinate Measuring Machine (CMM) is proposed and tested in this thesis. It consists of three major parts. In the first part includes a systematic approach to machine kinematic modelling. Using this approach results in an analytically based, forward kinematics model of the machine including its errors. In the second part, the model error functions are identified, at the constant thermal state. At a later stage of the research, error functions identification at varying thermal states. The third part of the proposed methodology includes the actual utilization of the model in a compensation strategy to correct for the machine errors. To visualize the effect of the proposed methodology, the performance of the CMM is evaluated using the standard ASME B.89 test before and after compensation for its errors in the constant thermal state. Dramatic improvements are obtained reducing the machine error in measurement by 93%. A modified version of the B.89 standard incorporating the thermal state of the machine is used to test the machine performance at varying thermal states. Improvement of the CMM performance by reducing the volumetric error by 97% is obtained. The research was expanded by applying the proposed methodology to CMM contouring. Regression analysis was proposed for the models. Thermal sensors were used to provide information to update the models. The CMM behavior was tested through simulation in tracking the diagonals of its work volume. Remarkable improvement in the tracking errors reduction is observed. Results obtained show an improvement in the CMM performance to a level close to machine resolution.

abstract: Doctor of Philosophy (PhD)


title: Axial Load Behavior of Thin Walled Steel Sections with Openings

contributor:
Sivakumaran, K.S.
Civil Engineering

subject:
Civil and Environmental Engineering
Engineering
Civil and Environmental Engineering

abstract:
In the application of cold formed steel structural members, holes are usually cut in the webs of sections for passing pipes or conduits. The Canadian standard for the design of cold formed steel sections does not provide sufficient design information for theses conditions. However, the American Iron and Steel Institute has recently provided design guidelines for sections with circular perforations based on limited available experimental data.

The purpose of this study is to determine the effect of size and shape of openings on the axial load behaviour of cold formed sections having different flat width-to-thickness ratios of webs.

A total of fifty five stub column tests were performed to provide design guidelines for stiffened plates with openings. Cold formed lipped channel steel sections were selected for the tests. Circular, square or slotted holes were cut in the centres of webs. The diameter, or width of the openings, varied from 0 to 0.6 times the flat width of the web. The tests were performed under axial compression and centering of the specimen was done with the help of strain gauges. Load versis axial shortening and out-of-plane deflections curves are plotted. Experimental buckling loads of the sections are obtained using the strain reversal method. Ultimate loads of the stub columns are calculated using the effective width approach given in North American codes. An empirical relationship was derived from the experimental data for the effect of square of circular openings in the web on the strength of cold formed sections.

It was found that the buckling load of a section decreases with respect to the buckling load of an unperforated section when size (diameter or width) of the opening is 20% of the flat width of the web but increases as the size of the opening is increased to 60%. The ultimate strength of sections with circular and square openings changes insignificantly when the size of the openings is 20% of the flat width of web. However, it drops to about 87% when the opening size is increased to 60%.

The shape of the opening influences the degree of reduction in strength. The shapes in increasing order of influence are circular, square and slotted openings. The maximum drop in compressive strength, about 14%, was for the section with a slotted opening, of width of about 48% of the web flat width. It also shows the importance of both the longitudinal and transverse dimensions of the opening. The design guidelines provided by the American Iron and Steel Institute (1986) are conservative. The equation proposed herein accurately predicts the effect of square or circular perforations on the strength of the cold formed steel sections.

abstract: Master of Engineering (ME)


title: Characterization of Pichinde Arenavirus Infection and Replication in Cell Cultures

contributor:
Harnish, Delsworth G.
Medical Sciences

subject:
Medical Sciences
Medical Sciences

abstract:
In order to establish a model of arenavirus infection of monocytes, human peripheral blood monocytes (PBM), human promyelocytic HL60 cells and human THP-1 promoncytic cells were infected with Pichinde virus (PV). PV replication was analyzed using a variety of assays which detected viral antigen, RNA and progeny virus. While human PBM were susceptible to PV infection and replication, HL60 cells did not support PV replication, even when cells were induced to differentiate to monocytes with the phorbol ester, PMA. THP-1 cells supported high levels of PV replication only when cells were exposed to PMA. THP-1 cells not treated with PMA supported lower levels of PV replication. Infection of PMA treated THP-1 cells by PV was dependant on protein kinase C (PKC) activation and host cell transcription.

The restriction of PV replication in untreated THP-1 cells was characterized further. Experiments with lysosomotropic compounds demonstrated that equal amounts of PV were bound and internalized by both THP-1 cells and PMA treated THP-1 cells. These studies also indicated that PV enters THP-1 cells by endocytosis into acidic vesicles. The expression of PV specific RNAs in PMA treated and untreated THP-1 cells were also examined. PV SRNA genomes, antiger omes, GPC mRNA, NP mRNA and L RNAs were expressed at higher levels in PMA treated THP-1 cells versus untreated THP-1 cells. Degradation of input viral S RNA could not account for the reduction of PV RNA replication in the untreated THP-1 cells. Increasing the multiplicity of infection of untreated THP-1 cells with PV was only able to partially overcome the restriction of virus multiplication. This suggested that the restriction of PV replication in the THP-cells occurred later than the initial binding and penetration stages but at, or just prior to, primary transcription of viral mRNAs. These studies supported a role host cell factors and a dependence on the activation or differentiation state of the THP-1 cell in order to support PV replication.

In order to gain further insight into the mechanisms utilized by PV to initiate transcription and replication, the 5' termini of PV S RNA genomes, antigenomes, GPC mRNA and NP mRNA were characterized. All termini sequenced had at least one extra nontemplated base. In clones that contained a single extra nucleotide, this was invariably a G nucleotide. Clones containing single nontemplated G nucleotides were only the derived from PV infected total cellular RNA. The 5' termini of NP and GPC mRNAs had on average 4-8 nontemplated bases. In addition, on genomic sense RNAs the base a -1 did not appear to be conserved. These data have important implication with respect to the mechanisms of PV transcription and replication initiation and are discussed in the context of two possible models.

abstract: Doctor of Philosophy (PhD)


title: Luke's Knowledge of the Septuagint: A Study of the Citations in Luke-Acts

contributor:
Westerholm, Stephen
Religious Studies

subject: Religion Religion

abstract: This study focuses on the OT citations and major allusions in Luke-Acts, in order to evaluate the conclusion of Traugott Holz (Untersuchungen über die alttestamentlichen Ziate bei Lukas) that Luke was only familiar with the LXX of Minor Prophets, Isaiah and the Psalms, whereas for the Pentateuch and historical books of the OT was dependant on the other sources such as testimonia. In doing so, the study aims to ascertain the extent of Luke's familiarity with the LXX, to ascertain whether Luke's LXX mss may have been Hebraicizing, and to understand how Luke's redactional activity affects the final form citations. The study concludes that Luke demonstrates knowledge of the LXX Pentateuch, but while Luke tends to use to LXX directly, at times he does use sources other than the OT either because he wished to be faithful to a source which he held in high regard, or because the version of the OT material in his source was particularly applicable to the context which he placed the OT reference. The ms of the LXX Minor Prophets which Luke used was likely Hebraicizing, but there is little significant evidence that he was using a Hebraicizing LXX ms for any other OT book. Finally, Lukan redaction is evident in all OT material both in altering the passages in such a way that his christological or apologetic interpretation is embedded in them, and in altering them stylistically (even to the point of summarizing or simply alluding to them) to fit the context of his narrative. The latter is most evident in the references to the Pentateuch which tend to be embedded in the Lukan narrative, and in which there is less material amenable to christological or apologetic interpretation.

abstract: Doctor of Philosophy (PhD)


title: Theoretical Analysis of T-Joints in Hollow Structural Sections

contributor: Civil Engineering and Engineering Mechanics

subject:
Civil Engineering
Engineering Mechanics
Civil Engineering

abstract:
A research program is presented to analyse the behaviour of the T-joints between square (or rectangular) HSS in the elastic range. An attempt was made to obtain the joint rigidity in both cases of loading, applied moment and branch member axial loads.

Two different joint types were analysed, unreinforced T-joint as well as the haunch reinforcement type. In each case, the chord top flange was considered as a thin pIate loaded on the perimeter of a rigid inclusion.

A theoretical model was established for the chord member to describe the continuity between the top flange plate with the chord webs, and to permit the introduction of elastically restrained edges for deflection as well as rotation.

The finite difference method was used together with a variety of edge boundary conditions to study the effect of the width ratio λ, the haunch size parameter λ₁ and the width-thickness ratio b/t.

The joint stiffness values (axial and bending) were obtained theoretically for 80 different joint sizes with 5 different edge conditions for the chord plate. A comparison with the available experimental and other theoretical results is also presented.

The main contribution in the study was the theoretical analysis presented for the haunch type connection, which has not been done previously.

An elastic stress analysis was also conducted to define limits for the working loads that may be applied to the joints without incurring yielding in the chord member.

The theoretical study confirms the results of tests that the unequal width unreinforced connection is generally too weak to be viable practically. However, the haunch connection, while not as "aesthetically attractive as the unreinforced type, has adequate strength and stiffness for most applications.

abstract: Master of Engineering (ME)


title: The Role of Glycogen Phosphorylase a Activation in in vivo Stimulation of Muscle Glycogenolysis

contributor: Medical Sciences (Blood and Cardiovascular)

subject:
Medical Sciences
Medical Sciences

abstract:
In animal models it has been demonstrated that stimulation of muscle glycogenolysis is associated with the activation of phosphorylase b (phos b) to phosphorylase a (phos a). In similar experiments in rat skeletal muscle, we found that sclatic nerve stimulation increased glycogenolysis in the first 15 sec. of stimulation in close correlation with an increase in the phos a activity. However by 30 sec. the phos a had returned to resting levels although glycogenolysis continued at a stimulated rate.

We did a series of experiments in human subjects to determine whether activation of phos b to phos a was essential in the activation of skeletal muscle glycogenolysis. Six normal male subjects underwent maximal voluntary isometric contraction of the quadriceps for 60 sec. Muscle needle biopsies were obtained at 0,10,20 and 60 sec. after onset of contraction. The rate of muscle glycogenolysis increased from less than 2.05 ± .35 at rest to 17.5 ± 0.7 umol/g during contraction, calculated from the increase in muscle lactate concentration. Enzyme analysis in the same biopsies revealed that the phos a: total phosphorylase ratios remained unchanged (0.05 ± 0.006). In separate experiments 5 normal male subjects exercised on a cycle ergometer at 66% of their VO₂ max. work load until exhaustion. After 40 min. exercise at 66% VO₂ max. load the muscle lactate concentration rose from 1.1 ± 0.005 umol/g at rest to 11.6 ± 0.8 umol/g. When subjects were exercised at 90% VO₂ max. until exhaustion; the change in muscle lactate was taken as a semi-quantitative reflection of the rate of muscle glycogenolysis. The change in the rate of music lactate production increased from 0.2 umol/g/min at the end of 66% work load, to 1.2 umol/g/min at exhaustion, indicating that glycogenolysis was stimulated. The phos a: total phosphorylase ratio and the active to total phosphorylase b kinase ratio remained unchanged at the end of 40 min. exercise and at exhaustion, from the resting value. We conclude that activation of phosphorylase (phos b to phos a conversion) is not an absolute prerequisite for stimulating glycogenolysis in skeletal muscle.

abstract: Master of Science (MS)


title: A Study of the Kinetics and Mechanisms of Materials Ejection from a Basic Oxygen Furnance

contributor:
Lu, W-K.
Cosma, D.
Metallurgy and Materials Science

subject:
Materials Science and Engineering
Metallurgy
Materials Science and Engineering

abstract:
A production basic oxygen furnace installation at Dominion Foundries and Steel Ltd., Hamilton, Ontario was used to develop and evaluate a method of measuring the rates of materials ejection during steelmaking. These rates are determined by periodic sampling at the mouth of the BOF with a tubular sampler, during the oxygen blow.

The materials ejected are classified into two categories, slopping and metal ejection. From the measured rates and analyses of ejected materials, combined with the composition of the slag and metal bath as obtained by direct sampling, certain insights are made about the mechanisms of materials ejection. Among the process variables examined, the metal bath level, oxygen flow and course of slag development showed the largest influence on ejection rates.

abstract: Master of Engineering (ME)


title: Stochastic Analysis of Manufacturing Errors in Cam Mechanisms

contributor:
Newcombe, W.R.
Mechanical Design

abstract: A realistic relationship between cam and follower motion is developed taking into full account the effect of manufacturing errors as defined by the specified error bound of the tolerances and clearances. Probability theory is used, and a general computer program has been developed to obtain the motion relationships and the effects of these equal errors on the standard cam motion programs are compared.

abstract: Master of Engineering (ME)


title: The Ideology of Large Landowners in Late Eighteenth Century Ireland

contributor:
Cuneo, Carl
Sociology

subject: Sociology Sociology

abstract: The ideology of the Anglo-Irish landlords in Ireland at the end of the eighteenth century is examined using a structural approach and placed in the context of class conflict and changing class alliances. It was found that the formulation of ideology was influenced by the landlords' desire to maintain existing class relationships and by their desire to gain greater control over Ireland's economic and political developments while remaining within the British social formation.

abstract: Master of Arts (MA)


title: Aesthetic Phenomena as Religion: A Study of Tristan and Isolde in The Birth of Tragedy

contributor:
Grant, G.P.
Religious Sciences

subject: Religion Religion

abstract: "It is only as an aesthetic phenomenon that existence and the world are eternally justified." This sentence, repeated twice in The Birth of Tragedy, and standing as it does as the essential purpose and motivation of the book, seems to be an intentional turning about of the Lutheran doctrine of sale fide. Here art appropriates to itself what is essentially a religious function; art is the realm of human activity where experiences are ordered and intensified, and subsequently, where redemption is to be gained. In formulating his ideas on art and on Greek tragedy Nietzsche was influenced by Wagner. It was Wagner's music, above all else, that opened up to Nietzsche new problems for art and religion. The musical dissonance or Tristan opened up to Nietzsche the secret key to Greek tragedy. It was the recognition of the Dionysian origin of tragedy, of its origin out of the spirit of music, that enabled Nietzsche to discover the essence of tragedy free from the conventional aesthetics, which expected tragedy to answer the criterion of the plastic arts, that is, of beauty. The Birth of Tragedy announced to the world, as Nietzsche wrote to Wagner, that "practically nothing remains of traditional theories of 'AEsthetics'." In what follows an interpretation of the religious significance of this new aesthetics will be offered by way of a study of the role of Wagner's Tristan and Isolde in The Birth of Tragedy.

abstract: Master of Arts (MA)


title: Plotting on an Electrostatic Printer/Plotter

contributor:
Kenworthy, D.
Computation

subject:
Computer Engineering
Computer Engineering

abstract: A survey of printers and plotters is given, and in particular the operation and capabilities of electrostatic printer/Plotters is discussed. An implementation of a plotting system which plots on an electrostatic printer/plotter is presented. This plotting system is designed to be compatible with the Benson-Lehner plotting system. The standard "PLOT" routine is replaced by a two pass system, which generates plots on the printer/plotter. In addition to the plotting system, an implementation of a graph utility is presented. This utility provides a single one pass system that plots one or more functions (where the function has one value for each value of x.)

abstract: Master of Science (MS)


title: A Strategy for the Periodic Assessment of the Degree of Hypertension Control in the Community

contributor:
Sackett, D.L.
Medical Sciences

subject:
Medical Sciences
Medical Sciences

abstract:
Hypertension is a chronic affliction which has a significant economic and health impact on Canadian society. Efforts to control hypertension are likely to produce significant returns, if the programs are effective in treating the hypertensive population. Before research efforts can be profitably directed at determining the most efficient method of achieving hypertension control, the state of, and deficiences in, the present health care system must be identified. The best approach to obtaining the information needed to evaluate the present system, is through a special-purpose, population-based survey.

The proper methodologic design of a population survey requires the use of probability sampling procedures. In addition, the blood pressure should be measured at several visits, using a standardized procedure. Examination of the literature reveals that no study satisfies all of the basic standards.

It is possible to identify six steps that must be followed if hypertension control is to be achieved. These steps form a conceptual model that can provide the basis of a general measurement strategy that can be used to assess the degree of hypertension control in a specific community.

This measurement strategy is used to develop a survey design to measure the degree of hypertension control in the Province of Ontario. A specially-created interview team will examine 3,850 individuals, located in selected geographic areas across the Province. Blood pressure will be measured using a Hawksley Random-zero Sphygmomanometer, at a maximum of three separate visits. Questionnaires will be developed to obtain valid information about health knowledge, attitudes and beliefs. The survey design will permit regional comparisons.

abstract: Master of Science (MS)


title: Weighted sum of order p and minisum location models

contributor:
Love, Robert F.
Wesolowsky, George O.
Parlar, Mahmut
Management Science/Systems

abstract: The Weighted Sum of Order p is a norm ([cursive l] bp -norm) that we adopt to estimate distances in a given transportation network. A distance function is used to transform the point coordinate differences of two points into an estimate of the travel distance between them. Distance functions are employed in applications such as location and location-allocation models, transportation and facility layout problems, distribution management software, computational geometry, distance calculations in Geographical Information Systems, accuracy validation of actual road network distance data, service cost quotations, and random problem generation to test algorithms. In this dissertation, we investigate the superiority of the [cursive l] bp -norm in distance estimation accuracy over the well known weighted [cursive l]p distance. We present computational procedures for determining the parameters of the [cursive l]bp -norm for a given transportation network and we provide theoretical and empirical results indicating its higher accuracy. In order to determine the best parameter values of the [cursive l]bp -norm and to measure its accuracy, we utilize an estimation errors function, the sum of Squared Deviations (SD ), as the goodness-of-fit criterion. We develop certain properties of the [cursive l]bp -norm and the SD function, and using these properties we produce a computational procedure for determining the parameters of the [cursive l]bp -norm. We apply the procedure in seventeen geographical regions and find that the [cursive l] bp -norm models the distances with a higher accuracy than its closest competitor, the weighted [cursive l]p -norm. A new method is devised to calculate the confidence intervals for estimated distances. Using this method, the confidence intervals for estimated actual distances are developed for the [cursive l]p norm and [cursive l] bp -norm. Our empirical study in the seventeen geographical regions indicates that better confidence intervals for the unknown actual distances are obtained with the [cursive l]bp -norm than the [cursive l]p -norm. A distance function constitutes an important part of the objective function in continuous location models. A minisum continuous location model is concerned with the determination of one or more new facility locations in a region so that the total transportation cost between the demand points and the new facilities and also between the new facilities is minimized. Total transportation cost is given by the sum of distances weighted by their corresponding demands. Since the model should represent the real situation as accurately as possible, the accuracy of the distance function employed plays a crucial role in terms of the validity and the applicability of the locational decisions. Therefore, we incorporate the new distance function in single-facility and multi-facility continuous location models and develop generalized iterative solution procedures and fixed point optimality conditions. We also investigate the convergence properties of the iterative procedure when it is applied to the single-facility minisum location models. In order to terminate the iterative procedure used to solve the location problem a bounding method is required. We consider a method which involves the solution of a rectangular distance location problem in each iteration, and provide its generalizations to the approximated [cursive l] p and the [cursive l]bp distance location problems. Finally, we develop the lagrangian and the conjugate dual formulations of the most general [cursive l]p -norm multi-facility minisum location model considering both linear and distance constraints, and also generalize our results to the [cursive l]bp -norm location models.

abstract: Doctor of Philosophy (PhD)


title: Follicular Development in Rabbits After Active Immunization to Testosterone

contributor: Medical Sciences (Growth and Development)

subject:
Medical Sciences
Medical Sciences

abstract:
The role of testosterone in follicular development and ovulatIon has been investigated by immunizing female rabbits to testosterone-3-bovine serum albumin (T-3-BSA). The intent of this procedure was to render any endogenously produced testosterone inactive by means of its high affinity binding to specific antibody.

In order to determine the time course of the effects of this procedure three groups of 12 - 6 control, 6 experimental - immaturely immunized rabbits were sacrificed at 5, 8 and 11 weeks after immunization. The effects observed at 11 weeks were compared with a group of 10 - 6 control, 4 experimental - maturely immunized rabbits sacrificed after the same length of immunization. In addition a group of 11 - 5 control, 6 experimental - immaturely immunized animals were mated to a proven male 14 weeks after immunization.

Animals were boosted regularly and the antiserum titer followed weekly. Blood samples were taken weekly for the determination of FSH and LH levels and the total and percent bound testosterone and estradiol. After sacrifice the ovaries and uteri were removed for histology. Follicular development was examined and the maximum follicular diameter ≥ 1.0 mm and ≥ 1.5 mm was recorded. In mated animals the number of corpora lutea per ovary were counted.

SignifIcant antiserum titers to testosterone were observed in all experimental rabbits by 5 weeks of immunization. Over the 14 weeks of the experiment values ranged from 1:700 to 1:52,000.

In control rabbits serum testosterone values were less than 0.5 ng/ml while values in experimental rabbits rose steadily over the length of the experiment (group values ranged from 0.6 ± 0.1 ng/ml to 2.1 ± 0.9 ng/ml, 2.2 ± 0.7 ng/ml to 5.7 ± 0.8ng/ml and 4.4 ± 1.2 ng/ml to 6.8 ± 1.2 ng/ml at 5,8 and 11 weeks respectively). Testosterone binding in control animals remained in the 93% to 95% range throughout the experiment while in experimental animals testosterone binding increased significantly to approximately 99% at 5 weeks of immunization and remained constant thereafter.

Estradiol values in control rabbits remained relatively constant throughout the ewperiment (group range: 50.7 ± 5.4 pg/ml to 81.8 ± 4.9 pg/ml). A consistent and significant increase in estradiol occurred in experimental animals (group values ranged from 69.5 ± 15.4 pg/ml to 88.5 ± 8.7 pg/ml, 74.5 ± 9.8 pg/ml to 118.5 ± 13.1 pg/ml and 81.6 ± 6.9 pg/ml to 157 ± 30.3 pg/ml at 5,8 and 11 weeks after immunization. Prior to immunization estradiol binding in experimental rabbits was not different from control values (range : 83% to 88%). There was a significant increase in estradiol binding by 5 weeks of immunization in the experimental groups (range: 89.4% to 94.5%). By 11 weeks estradiol binding increased to as much as 97.9%.

Follicular development was abnormal in T-3-BSA immunized rabbits. The ovaries contained numerous large cystic and hemorrhagic follicles. At 8 weeks experimental ovaries contained more follicles ≥1.0 mm (27.2 ± 3.1 versus 15.3 ± 2.9, p < 0.01) and ≥1.5 mm (5.83 ± 1.7 versus 0.42 ± 0.2, p < 0.005). At 11 weeks there were more follicles ≥ 1.5 mm in both immature (5.0 ± 0.9 versus 0.92 ± 0.31, p < 0.001) and mature (7.25 ± 0.92 versus 4.17 ± 0.74, p < 0.05) experimental ovaries. Increased vascularization, some thecal cell hypertrophy, and marked interstitial cell hypertrophy were characteristic of the experimental ovaries. There was also a significant increase in the number of ovulations in the experimental rabbits (8.0 ± 2.1 versus 4.4 ± 1.9, p < 0.005).

Immunization of female rabbits to testosterone is a useful tool for the study of hormone interactions in the regulation of follicular development and ovulation. In addition it may serve as a useful model for the study of the processes involved in the development of cystic ovaries.

abstract: Master of Science (MS)


title: Metal Speciation Determined Using Multiresponse Fluorescence

contributor:
Kramer, J.R.
Geochemistry

subject: Geochemistry Geochemistry

abstract: metal fate, transport and toxicity are speciation dependent. Natural organic matter (NOM) is a complex mixture of many potential metal binding sites and it is ubiquitous in the environment. Therefore, a site-specific, non-invasive, sensitive method is required to investigate metal interactions with NOM. This thesis considers the development and application of a multiresponse fluorescence method to determine site-specific binding of Al, Cu and H to model NOM ligands, fulvic acid and isolated NOM samples. Natural organic matter is treaed as a mixture of average binding sites. The minimum number of sites along with their excitation and emission wavelengths are determined from deconvolution of fluorescence surfaces using SIMPLISMA (Windig and Guilment, Anal. Chem. 1991, 63, 1425-1432). Fluorescence at wavelengths corresponding to these components is measured during metal titration and the multiresponse data are fit to a multi-site speciation model for the metal-NOM system. This multiresponse fluorescence method is validated in that it recovers known values for Al with two model ligands simultaneously and predicts free copper during a titration of Suwannee River fulvic acid within 0.1 log units when compared to the model of Cabaniss and Schuman (Geochim. Cosmochim. Acta 1988, 52, 185-193). A total of seven different fluorophores were identified in NOM isolated from nine different watersheds in Norway. Each sample contained four to six of the seven identified fluorophores. On average, at pH 4, the fluorophores bind Al with a strength similar to salicylic acid (logK'≈5.5), although there are stronger and weaker sites with logK'≈7 and logK'≈3, respectively. The speciation results are dependent on the isolation method used to obtain the NOM sample. For the NOM samples, the difference between reverse osmosis and low-pressure-low-temperature evaporative isolates are as large as the differences between sampling sites. Suwannee River fulvic acid is represented by five fluorescent binding sites for Cu, Al and H binding. The constants for Al and Cu are consistent with salicylic acid-like sites and the H binding can only be explained if diprotic sites are used. Thus, multiresponse fluorescence methods allow discrimination between monoprotic and polyprotic models. Finally, a protocol is proposed for multiresponse fluorescence determination of metal interactions with NOM.

abstract: Doctor of Philosophy (PhD)


title: Digital Baseband Processing of a Mills' Cross Array Antenna

contributor:
Haykin, Simon
Electrical Engineering

subject:
Electrical and Electronics
Electrical and Electronics

abstract:
A digital signal processor, operating at baseband, is described for the scanning of a Mills' cross array antenna. The processor uses time modulation to scan the pencil beam produced by the array in a raster-like fashion over the prescribed sector. The scheme uses within-pulse scanning in order to avoid the loss of power in the fan beams outside the area covered by the pencil beam. This processor provides flexibility in applying different types of aperture distribution to modify the side-lobe structure of the antenna pattern. It provides a simple means for changing the scanning rate of the array.

The different types of scanning technique are reviewed briefly. A detailed mathematical analysis of time modulation scanning technique is presented. Experimental results are included to demonstrate the practical feasibility of the digital baseband processor for scanning the Mills' cross array antenna along prescribed look directions inside the visible region of interest.

abstract: Master of Engineering (ME)


title: On the Call for a Feminist Notion of Autonomy in Biomedical Ethics

contributor:
Boetzkes, Elisabeth
Philosophy

subject: Philosophy Philosophy

abstract:
In this thesis I argue that the received view of autonomy is insufficient for both biomedical ethics and feminist theory. I begin with an examination of the received view of autonomy; I then indicate the way in which this view of autonomy has been applied to health care ethics. A feminist relational approach to autonomy is explored: I argue that such an approach has many strengths in that it gives us a more accurate picture of the self-in-relationships and that it recognizes many social and structural conditions that may impede an individual’s attempts to be autonomous.

This feminist relational approach to autonomy, once defined, is applied to the medical/social practices of cosmetic surgery and contract motherhood. I do this to show the practical implications of this contextual approach to autonomy.

abstract: Doctor of Philosophy (PhD)


title: Process Measures of Quality of Care: A Strategy for Validation against Outcomes

contributor:
Sackett, D.L.
Clinical Epidemiology

subject:
Life Sciences
Life Sciences

abstract:
Quality of care evaluation strategies are needed for meaningful assessment of health care delivery for research, quality assurance and educational purposes.

For the purpose of improving strategies for measuring quality of care, this thesis first reviews methodologic features of available measurement strategies as reported in the current scientific literature. Secondly it proceeds with the development of a descriptive research design to evaluate the criterion validity of a strategy for evaluating process items by comparison with comprehensive outcome measures including physical, emotional and social function. Thirdly, the development of a new strategy for measurement of interpersonal skills, which is incorporated into the process evaluation, is described.

The objective of the study is to study patients with acute myocardial infarction in order to determine whether measurable differences in the care administered to and received by these patients result in clinically significant differences in these patient's health status six months later. Acute myocardial infarction has been chosen as a disease appropriate for the testing of this strategy because if its high incidence, its functional impact upon the patient, the variation in process management items performed by different physicians, the different clinical settings involved, the relative diagnosis and availability of an inception cohort. A community hospital setting has been selected for the reason that, compared with a teaching hospital setting, the generalisability of the study to the practice of other physicians will be greater since the majority of physicians involved in the care of patients with acute myocardial infarction work in community hospital settings.

abstract: Master of Science (MS)


title: Do Simplified Drug Regimens Improve Compliance?

subject:
Medical Sciences
Medical Sciences

abstract: A PROTOCOL FOR THE DESIGN OF A RANDOMIZED CLINICAL TRIAL IN A FAMILY PRACTICE SETTING IS DESCRIBED. THE TRIAL IS DESIGNED TO TEST IF TWICE A DAY (B.I.D.) ANTIBIOTICS PRODUCED BETTER COMPLIANCE THAN THE STANDARD FOUR TIMES A DAY (Q.I.D.) REGIMENS. THE DISEASE MODELS OF STREPTOCOCCAL PHARYNGITIS AND UNCOMPLICATED URINARY TRACT INFECTION ARE USED BECAUSE OF THEIR SIMILARITY AND BECAUSE THEY ARE COMMON IN THE FAMILY PRACTICE SETTING. COMPLIANCE MEASURES INCLUDE URINE ASSAY FOR ANTIBIOTIC PILL COUNTS AND DROP OUT RATES. COMPLIANCE WILL BE ANALYZED IN RELATIONSHIP TO THE TYPE OF REGIMEN, SIDE EFFECTS AND DISEASE OUTCOME.

abstract: Master of Science (MS)


title: Measures of Association on a Bibliographic Data Base

contributor:
Rink, R.A.
Computation

abstract: A critical survey of research done in automatic, indexing and classification and statistical linguistics, of importance to the study of bibliographic data bases, is given. A theory of measures of association in vector form is presented and applied using the FAMULUS system for storage and retrieval, and a data base in the social sciences constructed using that system. Certain conclusions are drawn regarding the usefulness of the various measures of association employed, and some argue of future research are given.

abstract: Master of Science (MS)


title: Parental origin of triploidy and trisomy in human miscarriages

subject:
Medical Sciences
Medical Sciences

abstract:
Caspersson (1970) discovered that each chromosome pair has a characteristic banding pattern when chromosomes are stained with the fluorescent dye, quinacrine. With this dye there are certain chromosome regions which are polymorphic. These regions can be used as markers in the study of the inheritance of chromosome anomalies. The purpose of this study was to determine, using chromosome markers, the parental origin of the extra chromosomes found in triploid and D, G trisomic spontaneous abortuses. Polymorphisms in the chromosomes of parents of 15 triploid and 12 trisomic abortuses were compared with those of their abortus to determine which parent donated the extra chromosome(s). The distribution of the markers was used to determine whether the error occurred during meiosis I or meiosis II or, in the case of triploids, to distinguish between a meiotic error and dispermy. Of the 15 triploids examined, 7 were informative as to the origin of the extra set of chromosomes. In 3 of these there was failure to extrude to second polar body during oogenesis. In 3 other cases it was impossible to distinguish between an error during meiosis of spermatogenesis and dispermy. The other informative case definitely arose by dispermy. Mechanisms for the origin of triploidy were discussed, in particular, aging of gametes. Only 1 of the 12 trisomies examined was informative. This was a trisomy 22 in which the extra 22 was from the mother but it was not possible to distinguish between non-disjunction during meiosis I and meiosis II. Possible mechanisms for the production of trisomies were discussed including maternal irradiation, autoimmune processes, possible endocrine factors and drugs.

A number of technical factors which influence the appearance of polymorphic regions were also discussed.

abstract: Master of Science (MS)


title: Ideology Surrounding Women's Work in Canada, 1931-1956

contributor:
Synge, Jane
Sociology

subject: Sociology Sociology

abstract: Ideology determines how one experiences the world, shapes beliefs and expectations. Ideology is rooted in the structural dynamics of the social formation within which it exists. The articulation of the ideological with the economic structure can become problematic at certain points in time. This thesis uses a structural analysis to explore how changes in the economy have affected women in the Canadian labour force and how these changes related to the ideology surrounding women's work. Integral to this thesis is an analysis of how the State, through its labour policy, its government publications, and so on, does at times mediate between the economic situation and the dominant ideology as reflected in the popular media. This ideology is manifested through the institutional structure of the State as it influences both labour policy and the media.+ This thesis presents empirical data on the changes that took place in Canada between 1931 and 1956 in the ideology surrounding women's work. We take articles appearing in popular magazines and government publication of the era to be manifestations of the dominant ideology. We analyze materials in Maclean's, Chatelaine, Saturday Night, and the National Home Monthly. We analyzed government publications relating to labour policy; focussing on the Labour Gazette, and several reports and publications of government committees. The thesis begins with a theoretical outline. We discuss the concept of ideology and consider its role in the reproduction of class relations, the concept of a reserve army of labour, and finally, a brief summary of the concepts outlined above. We conclude the first chapter with a discussion of the methodologies used in our qualitative and quantitative analyses. The second, third and fourth chapters use qualitative analyses of periodicals to trace the articulation of the ideoloeical with the economic. Specific references are made to the media, to labour policy and to changes in the economy. These chapters deal with three distinct time periods -- with the Depression, with the World War Two years, and the period 1946 to 1956. In Chapter 5 we present a quantitative content analysis of selected magazines over the three periods. Our analyses of variations in the frequency of publications of articles relating to women's work and their activities both inside and outside the home confirm the shifts in emphasis over the period 1931 to 1956 that emerge from the earlier quantitative analyses. However, while the content and tone of articles does change with time, as is revealed in the qualitative analysis, the majority of articles have always related to traditionally domestic and feminine concerns. The data show an increasing professionalization of the housewife role. We conclude with a discussion of the importance of ideology in determining what is defined as women's work, and the importance of the control of women's labour market participation to the maintenance of the existing capitalist economic order.

abstract: Master of Arts (MA)


title: An Econometric Analysis of the Number and Timing of Births: The Case of Vietnam

contributor:
Spencer, B.G.
Denton, F.T.
Dooley, M.D.
Economics / Economic Policy

subject: Economics Economics

abstract: This thesis represents an intensive econometric study of two important aspects of reproductive behavior - namely the level of fertility and the intervals between births. The analysis is economics-based, but the standard microeconomic framework is extended to take into account the effects of social factors on reproduction. The estimation is based on data from the 1988 Vietnam Demographic and Health Survey. The initial analysis of the determinants of fertility (defined as the number of children ever born per woman) is conducted within a static framework, and three alternative statistical models (OLS, Poisson and ordered-logit) are estimated and the results compared. Fertility decision-making is then modeled as a dynamic sequential response process, with particular attention to the effects of sex preference and child mortality on subsequent fertility. The analysis of birth intervals is based on the estimation of birth non-parametric life table methods and the (semi-parametric) proportional hazard model. Among the main results of the study is the finding that individual and social characteristics generally have little effect on reproductive behavior in the first ten years or so of reproductive life, apparently reflecting the strong desire of typical couples to have at least two children. Such characteristics of the wife as education, knowledge of contraceptives, the industrial sector in which she works, and whether she lives in an urban or rural area are found to have statistically significant effects on both the level and timing of completed reproductive behavior, although the magnitudes of the effects are generally moderate. Certain characteristics of the husband (notably, his education attainment and the industrial sector in which he works) also affect the level and timing of births. However, no evidence is found to support an opportunity-cost effect of either the wife’s or the husband’s education on fertility. That finding is readily interpreted in the Vietnamese context and may explain why the estimated effects of education are considerably smaller in Vietnam than in other, more market-oriented countries. Finally, in Vietnam, the preference for sons is strong and largely independent of socioeconomic variables: furthermore, the evidence indicates that parents, whatever their levels of education or other characteristics, wish to have one living son, not necessarily more.

abstract: Doctor of Philosophy (PhD)


title: An Analysis of Laboratory Utilization in a Family Practice Unit

contributor:
Lyons, Denis
Medical Sciences

subject:
Medical Sciences
Medical Sciences

abstract:
This thesis is a report of the evaluation of laboratory utilization by a Family Practice Clinic. The evaluation covered the month of October, 1975. All encounter forms generated by patient visits in October were included in the study sample.

The encounter form records whether a patient is new to the clinic, the nature of his visit, whether the visit is the first for a given problem or a follow-up visit, the diagnosis made at the visit, and any laboratory procedure ordered. These variables were combined in an instrument that determined the motive a physician might have for ordering a laboratory investigation.

Three motives for ordering a laboratory procedure were defined, ie. casefinding, monitoring or diagnostic use. Tests requested were classified into the three categories. The classification instrument was validated and shown to be reliable. The data used from the encounter was shown to be only 50% reliable with unrecorded information being the major factor contributing to the unreliability of the data.

The study showed that requests for laboratory procedure can be classified by the three motives for requesting them, ie. diagnosing, casefinding or monitoring. Sixty-one percent of the tests were used for diagnosis, 11% for casefinding and 28% for monitoring. Age, sex, nature of visit and the diagnosis of the patient were shown to be important variables in explaining the physician's use of the laboratory.

The results indicate that the classification logic is an operational tool but in this study its validity has not been completely assured.

abstract: Master of Science (MS)


title: Chemical Speciation(I) in Freshwater

subject: Geochemistry Geochemistry

abstract: Recently, background silver concentrations in freshwater have been shown to be only 0.001-0.01 nanomolar. However, locations with significant sewage input have concentrations at least two orders of magnitude greater. Although geochemical processes appear to regulate background silver at picomolar levels, there is concern that point-discharges of silver may produce acute and/or chronic toxic responses in aquatic organisms. How silver speciates in these waters will largely determine its bioavailability and toxicity. This thesis project investigated silver(I) speciation in freshwater. Silver binds much more strongly to sulfide, S(-II), containing ligands compared with ligands containing nitrogen and oxygen. Determinations of silver-sulfide formation constants gave log K values of 11.0 to 13.0 compared with log K values of <6.0 for ligands containing nitrogen and oxygen. Thermodynamic calculations suggest that silver in freshwaters is over-saturated relative to Ag₂S(s) solubility (Ksp = 35.94, 25℃, μ = 0.0) and that predominant silver species in freshwater should be AgHS〫and Ag-thiolates. However, field studies at a sewage treatment plant, Dundas, Ontario and at an old mining camp, Cobalt, Ontario, demonstrated that silver is 90%-100% colloidally bound, which explains silver's apparent over-saturation in natural waters. Concentrations of aquo silver species (AgHS〫and Ag-thiolates) represent <10% of total silver in these waters. The field studies also demonstrated that inorganic sulfide is present in oxic waters at 10-200 nM (80-100% colloidally bound) while thiol concentrations are below 1 nM. Using a competitive ligand equilibration-solvent extraction technique we showed that silver is bound to the inorganic sulfide. This inorganic sulfide is likely present as metal sulfide clusters that are bound to natural organic matter (NOM). The complexation of sulfide by metals would explain its persistence even in oxic waters. In sediments silver likely forms Ag₂-S(s) as long as the silver to sulfide ratio is <1. A laboratory study demonstrated that silver reacts rapidly with sedimentary FeS and behaves thermodynamically like a distinct acanthite, Ag₂S(s), phase. Silver measurable in the porewaters is probably associated with colloidal metal sulfides, as was observed for the surface waters and sewage treatment plant effluents. In summary, the findings of this thesis research showed for the first time that sulfides are important to the speciation of silver not only in anoxic sediments but also in oxic surface waters and sewage treatment plant effluents. Based on these findings, we recommend that the SEM/AVS approach, developed as a sediment quality criterion, could also be used as a water quality criterion for silver. However, before adopting this approach, toxicity studies need to be carried out using well-characterized silver-sulfide species to verify that sulfide protects aquatic organisms from silver bioaccumulation and toxicity.

abstract: Doctor of Philosophy (PhD)


title: Elastic Stabilization of Arrays of Precipitates in Al-4%Cu Alloy

contributor:
Purdy, G.R.
Metallurgy

subject: Metallurgy Metallurgy

abstract:
The elastic interaction of the new phase coherent particles with tetragonal distortion is considered. The analysis shows that the elastic energy may be minimized by the formation of regular tridimensional arrays.

Studies of the variations of the interaction energy of the Tyapkin array with respect to displacements and volume perturbation of the particles (in the finite approximation) lead to the conclusion that the periodic distribution is stable.

abstract: Master of Engineering (ME)