title: Fluorine-18 as a tracer in inorganic and organic syntheses and its application to positron emission tomography

contributor:
Schrobilgen, Gary J.
Chemistry

subject: Chemistry Chemistry

abstract: The application of fluorine-18 to the study of inorganic and organic reaction mechanisms has been investigated. From the distribution of [¹⁸F] among the decomposition products of NF₄⁺H*F₂⁻ it has been shown that the attack of H*F₂⁻ on NF₄⁺ occurred exclusively on the fluorine and not on the nitrogen contrary to predictions based on bond polarities. An [¹⁸F] changes experiment between ClF₅ and [¹⁸F]FNO showed complete randomization of the [¹⁸F] between the two molecules. A ¹⁹F NMR study using neat ClF₅ and ClF₅ in anhydrous HF solution in the presence and absence of excess CsF showed slow chemical exchange between ClF₅ and CsF in anhydrous HF at room temperature. Evidence from both [¹⁸F] radiotracer and ¹⁹F NMR studies has provided conclusive evidence for the existence of the ClF₆⁻ anion. Fluorine-18 has also been used as a probe to study the selectivity of F₂ towards aromatic amino acids in different solvents. Differences in reactivity and selectivity of dilute fluorine towards tyrosine and protonated tyrosine in HF and HF/BF₃ respectively, have been exploited for the synthesis of 2- and 3-fluorotyrosine. Results from the radiofluorination of m-tyrosine in different solvents showed that anhydrous HF is an ideal solvent for the synthesis of [¹⁸F] fluoro-m-tyrosine. Fluorine-18 labelled fluoro-m-tyrosine, has been synthesised and used, in conjunction with Positron Emission Tomography, to study striatal aromatic acid decarboxylase activity in living human brain. It has been demonstrated that [¹⁸F] fluoro-m-tyrosine will probably supersede [¹⁸F] fluorodopa as the compound of choice to study the dopaminergic pathway in man.

abstract: Doctor of Philosophy (PhD)


title: Presheaf Toposes and Propositional Logic

contributor:
Banaschewski, Bernhard
Mathematics

subject: Mathematics Mathematics

abstract:
To each non-degenerate topos [symbol removed] we associate L([symbol removed]), the intermediate propositional logic (i.p.l.) consisting of those polynomials, built up from variables, 0, 1, ʌ, v and →, which become valid when interpreted in the natural internal Heyting algebra structure of the subobject classifier of [symbol removed]. For various polynomials φ, we give first order characterizations for the class of small categories determined by the condition φ ε L([symbol removed]) - where [symbol removed] is the topos of sets and C ranges over small categories. A basic example is:

v v ד v ε L([symbol removed]) iff C is a groupoid.

The presheaf topos [symbol removed], of actions of a single idempotent, whose i.p.l. is given by:

φ ε L([symbol removed]) iff ד u v v v (v → u) ꜔ φ,

is used to exemplify a relativization of the basic example, to toposes. For each topos [symbol removed] we introduce r([symbol removed]), the set of all polynomials φ such that for all internal categories C of [symbol removed], if φ ε L([symbol removed]) then C is a groupoid. Using a theorem of Jankov's we can compute ɼ([symbol removed]) when M belongs to a certain class of finite monoids that includes semilattices; in particular: φ ε ɼ([symbol removed]) iff φ ꜔ u v (u → (v v ד v)). This polynomial - the cogenerator of ɼ([symbol removed]) - is strictly weaker than the generator of L([symbol removed]).

We use the higher order type theoretical language of a topos ([symbol removed]), developed in the first half of the thesis, to establish that for an extensive class of polynomials, the condition φ ε ɼ([symbol removed]) can be internalized; that is, we can define a formula ([symbol removed]), of the language of [symbol removed], such that: φ ε ɼ([symbol removed]) iff [symbols removed].

This theorem has as particular cases:

(1) [symbols removed]

(2) [symbols removed]

(3) [symbols removed]

abstract: Doctor of Philosophy (PhD)


title: Neural Network Techniques in Managerial Pattern Recognition

contributor:
Archer, Norman P.
Management Science/Systems

subject:
Management Information Systems
Management Information Systems

abstract:
The management area includes a large class of pattern recognition (classification) problems. Traditionally, these problems have been solved by using statistical methods or expert systems. In practice, however, statistical assumptions about the probability distributions of the pattern variables are often not verifiable, and expertise concerning the correct classification is often not explicitly available. These obstacles may make statistical methods and expert system techniques difficult to apply. Since the early 1980s neural network techniques have been widely used in pattern recognition, especially after Rumelhart's back propagation learning algorithm was adapted to the solution of these problems. The standard neural network, using the back propagation learning algorithm, requires no statistical assumptions but uses training sample data to generate classification boundaries, allowing it to perform pattern recognition.

In this dissertation the neural network's behavior in classification boundary generation is analyzed. Based on this analysis, three models are developed. The first model improves the classification performance of neural networks in managerial pattern recognition by modifying the training algorithm through the use of monotonicity. Using simulated and real data, the developed model is tested and verified. The second model solves bias problems caused by small sample size in neural network classification results. The third model develops multi-architecture neural networks to supply decision makers with more natural pattern recognition information, based on fuzzy theory.

abstract: Doctor of Philosophy (PhD)


title: Spatial Distribution of Active Sites and Bubble Flux Density

contributor:
Judd, Ross L.
Mechanical Engineering

subject:
Mechanical Engineering
Mechanical Engineering

abstract:
An experimental investigation is presented for boiling of water at atmospheric pressure on a single copper surface. The distribution of active site was investigated at different levels of heat flux and subcooling. The results obtained indicated that the active sites were distributed randomly on the heating surface, since the distribution of active sites followed the Poisson distribution.

Changes in heat flux and subcooling did not affect the distribution of active sites, although additional active sites formed among the sites which had been already activated when heat flux was increased.

The frequency of vapour bubble emission and the bubble flux density have been studied as well. The results obtained showed that the surface superheat had a great effect on the vapour bubble emission frequency, although the influence of subcooling was of lesser significance. The bubble flux density showed a marked tendency to cluster and was not uniformly distributed over the heating surface.

abstract: Master of Engineering (ME)


title: N-Compact Frames and Applications

subject: Mathematics Mathematics

abstract:
This thesis is a study of what it means for a frame to be N-compact. We find that the frame analogues of equivalent conditions defining N-compact spaces are no longer equivalent in the frame context; one must be careful in deciding what the appropriate frame notion is. We show that it is the assumption of a choice principle (the Axiom of Countable Choice) which provoke9 this departure from the spatial situation.

We analyze the several possibilities and show how it is the 'H-N-compact' frames which best embody the notion of N-compactness. We develop the theory and construct the H-N-compactification, which uses a frame-theoretic version of the classical ultrafilter formulation of the spatial N-compactification. We use this compactification to show how these frames relate to the other 'N-compact' frames. Along the way we construct a 0-dimensional Lindelōf co-reflection, and show how this relates to the H·N-compactification.

Recent works in Abelian group theory have employed the groups C(X, Z) in the study of reflexivity and duality. The N-compact spaces are important in this regard because of a theorem of Mrówka which shows how a group homomorphism from C(X, Z) to Z is determined on a small part of X, if X is N-compact. We use the H-N-compact frames to lift thus to a result about any group of global sections of a sheaf of Abelian groups. We then are able to give a sufficient condition for the local reflexivity of a sheaf to lift to global reflexivity; it is enough that the frame is H-N-compact. We show that the groups known to be reflexive (in ZFC) each appear as a group of global sections of some sheaf on an N-compact frame, or as the dual of such a group of sections. We can then use our generalized Mrówka's Theorem to establish their reflexivity.

In the final chapter we apply the techniques of Chapter 1 to the study of realcompact frames. These have been studied, but the definition usually given is quite restrictive. We construct the H-realcompactification and develop enough of the basic theory of H-realcompact frames to justify proposing that these be thought of as the realcompact frames.

abstract: Doctor of Philosophy (PhD)


title: Ore Localizations and Irreducible Representations of the First Weyl Algebra

contributor:
Müller, Bruno J.
Mathematics

subject: Mathematics Mathematics

abstract:
This thesis studies two problems for the first Weyl algebra A = A₁(C), namely, Ore localizations and irreducible representations.

Our contribution to the first problem is that we find two collections of torsion theories which can be determined by Ore sets. The first consists of all torsion theories generated by classes of simple A-modules which contains either all C[q]-torsion or all C[p]-torsion simple A-modules, up to an automorphism of A (for instance, any torsion theory generated by all but countably many isomorphism classes of simple modules). The second consists of all torsion theories generated by classes of at most linear simple A-modules.

The second part of the thesis studies the irreducible representations of A, i.e., the structure of simple A-modules. We generalize Block's result for linear simple modules, namely, that every linear simple module can be expressed in the form C[X,α⁻¹] for some α ∈ C[X], to arbitrary simple modules which satisfies two conditions which are necessary and sufficient. The second condition is stated in terms of two invariants of the similarity class corresponding to the given simple module, which are explicitly checkable. An important tool is an index theorem which relates two different realizations of the same simple module.

abstract: Doctor of Philosophy (PhD)


title: The role of social information in the development of preferences for nutritious foods by Long-Evans rats

contributor:
Galef, Bennett G.
Psychology

subject: Psychology Psychology

abstract:
It has long been assumed that animals select nutritionally adequate diets via innate and learned preferences for nutritious foods. However, animals typically fail to select a nutritionally adequate diet when a) more than two or three alternative diets are available, b) a needed nutrient is available only in a relatively unpalatable food. and c) recovery from nutrient deficiency is delayed. Because these three conditions are likely to occur in natural settings, the inability of animals to select adequate diets under such conditions suggests that our current understanding of diet selection in nature is in need of revision.

The present research indicated that failures on the part of animals to select adequate diets have been due to the artificial testing conditions used in previous diet-selection experiments. Animals in previous experiments were tested in isolation, and have therefore been denied a source of dietary information available to their wild counterparts: the diet selection behaviour of others. In the present research, rats rapidly developed preferences for a protein-rich food under the three conditions listed above when they were exposed to others feeding upon the protein-rich diet. Present data indicated that rats adopted the preferences of others by matching what other rats ate, rather than matching where others ate.

The responses of rats to the feeding behaviour of others seem well-matched to the goal of obtaining reliable and accurate dietary information from others. For example, rats were more likely to match a diet preference if several others arc displaying the same diet preference rather than if just one other exhibited that preference. Such a behaviour might serve to prevent rats from adopting an idiosyncratic, maladaptive preferences; it seems unlikely that several rats would display the same idiosyncratic maladaptive preference. Rats were also more likely to match the diet choices of large rats than small rats. Because large rats in the wild arc more likely to have acquired beneficial diet preferences than those of small rats, the tendency to preferentially match the diet choice of large rats would result in superior diet choices.

The degree to which rats match the diet choices of others while nutrient deprived and nutrient replete also suggests an adaptive interpretation. Nutrient-deprived rats matched the diet choices of others to a greater extent than did rats that were either recovering from nutrient-deprivation or completely recovered from nutrient-deprivation. The mechanism underlying the enhanced tendency of nutrient-deprived rats to match the diet choices of others did not appear to be an enhanced susceptibility to social influence. Rather, nutrient deprivation rendered rats more likely to restrict their diet choice to a single food. Thus, when nutrient-deprived rats were exposed to a demonstrator, they showed a greater tendency than non-deprived rats to restrict their feeding to the demonstrator's diet

Taken together, the results obtained in the present research indicated that social cues are a vital source of dietary information. In order to obtain a complete understanding of how rats, and, undoubtedly, other animals as well, select diets in natural settings, it is necessary to obtain a clearer understanding of the role of social influences in diet selection.

abstract: Doctor of Philosophy (PhD)


title: A Study of Pressure Response and Two-Phase Phenomena in a Nuclear Power Plant Pressurizer

contributor:
Garland, Wm. J.
Chang, J.-S.
Nuclear Engineering

subject:
Nuclear Engineering
Nuclear Engineering

abstract:
In a pressurizer water nuclear power plant, the pressure of the primary heat transport system is maintained mainly through the operation of a pressurizer. Existing pressurizer models are not satisfactory in predicting pressurizer behaviour in response to operating or accidental transients. This is mainly due to lack of understanding on non-thermodynamic equilibrium and other local two-phase phenomenon in the pressurizer. The primary objectives of this work are to prepare necessary tools for a systematic study of the pressurizer and to investigate pressurizer phenomena under quasi-steady-states and to determine the effects of major pressurizer control parameters to the behaviour of the pressurizer.

To achieve the first objective a rate form of equation of state is analytically derived. It is used as an analytical expression of pressurizer pressure response as well as to support and to guide the rest of the work. lDRIFF, a two-phase simulation code consisting of a lumped homogeneous model and a differentially formulated drift-flux model, is developed to accommodate any physical assumptions in pressurizer modelling. A laboratory scale pressurizer system, complete with a glass pressurizer tank, a simulated primary heat transport system and substantial monitoring facilities is also developed. Together, they provide analytical, numerical and empirical tools needed in a systematic study of pressurizer phenomena.

To achieve the second objective, various quasi-steady-state conditions in the pressurizer are simulated experimentally and four distinct flow regimes are identified in the pressurizer. With the help of numerical extrapolation by using the IDRIFF code, the data are analyzed to produce, among other things, a correlation of average void fraction, a pressurizer flow-regime map with the transitions of flow-patterns semi-analytically modelled, and a general understanding of pressurizer behaviour under quasi-steady-states.

In addition, the effects of changes in pressurizer heater, steam-bleed flow and pressurizer surge-line flow to the behaviour of the pressurizer are investigated. Perturbation transients, where the dynamic effect of the parameters can be isolated from other transient factors, are empirically and numerically simulated. The resulting overall pressurizer behaviour and observed local phenomena are analyzed in terms of their relation to quasi-steady-state behaviour, global and local pressure response, local phase distribution and pressurizer stability. Several flow and heat transfer mechanisms, such as the temperature of the steam being controlled by the liquid saturation pressure, are also summarized.

It is believed that the preparation of research tools and the accumulation of information learnt during the course of the current endeavour has formed an essential basis for a further systematic study of nuclear power plant pressurizer and has brought the study one step closer to the goal of achieving a complete understanding of pressurizer phenomena.

abstract: Doctor of Philosophy (PhD)


title: "Video lets me see what I mean": The social world of video artists

contributor:
Knight, Graham
Sociology

subject: Sociology Sociology

abstract: This dissertation examines practices of cultural resistance and subversion among marginalized cultural producers within the context of theories of hegemony (Gramsci,1988; Hall, 1986) and theories of discourse (Barthes, 1975; de Certeau, 1984; Fiske, 1989). It is a study of the struggle to produce and circulate meanings in the shadow of dominant discourses which may tend to contain alternative cultural production practices. It is also a study of a unique art world that poses a threat to the larger art world and the social, political and economic foundations upon which that larger art world rests. The empirical focus is the social world of Canadian cultural producers who call themselves video artists. A methodology of participant observation in combination with archival research and textual analysis is used. This project is also an attempt to clarify the methodological directions appropriate for studies of discourse and hegemony. I argue that video art practices are a form of subversive deviance that threatens the institutions which produce dominant discourses such as the institution of television. I attempt to demonstrate that these threats are met with containment strategies which range from selective appropriation of aesthetic and technical innovations, to enticement into the agendas of power which support dominant discourses. I conclude that these containment strategies are effective, but incomplete and have left video artists with relatively minor, but nonetheless significant, victories in the arena of cultural production. This study also has important theoretical implications regarding theories of television production and consumption. Video artists are shown to use the medium of video in ways which point out the contradictions inherent within the institution of television, an institution which uses the same medium. The cultural context of production and consumption is shown to be the decisive variable in constructing the differences between video art and television.

abstract: Doctor of Philosophy (PhD)


title: U-Series Dating of Carbonates by Mass Spectrometry With Examples of Speleothem Coral and Shell

contributor:
Ford, D. C.
Schwarcz, H. P.
Geography

subject: Geography Geography

abstract:
Uranium series dating is a well established technique for dating carbonate deposits of the last 350,000 years. The most common carbonates which have been dated are cave calcites (speleothem) and corals. The technique relies on the buildup of ²³⁰Th over time by radioactive decay of ²³⁸U and ²³⁴U, in materials which were initially free of ²³⁰Th. The ratios of the activities of ²³⁰Th/²³⁴U and ²³⁴U²³⁸/U are entered into the standard equation for radioactive decay which is then solved for time. These ratios have traditionally been measured by counting the alpha particle emissions from each isotope. An alpha counting laboratory was set up in McMaster in the early 1970s and is still in operation today. The technique has been improved considerably but the precision of dating by this method is limited by the statistics of counting small numbers of emissions from the trace quantities of isotopes trapped in the carbonate crystal lattice. Typically U ratios can be measured to 1σ precision of 1% and Th ratios to 3%. This leads to an error in the estimated date of ~10%. Alpha counting requires a rather large sample, varying from ~10 g to ~40 g depending on the U content and age of the sample. It also requires extensive chemical preparation of the sample to isolate U and Th from the matrix and to completely separate U from Th.

The development of high resolution and high abundance sensitivity thermal ionization mass spectrometry in the last decade has allowed for the measurement of heavy atom ratios to high precision with very small samples. The McMaster geology department acquired such a machine in the 1980s and it has been adopted for the measurement of ²³⁰Th/²³⁴U and ²³⁴U/²³⁸U ratios. The typical 1σ precision attainable for U ratio measurement is 0.03% and for Th ratios 0.15%, which leads to an error in the estimated age of only ~0.5%. This is more than an order of magnitude better than that attainable by alpha counting. The sample size required varies from ~0.3 g to ~6 g depending on the U content and age of the sample. Thus sampling can be at higher density or resolution than for alpha counting. The technique requires rigorous purification of U and Th from the matrix but separation of U from Th can be rough, so the chemical preparation is simpler than that for alpha counting and usually involves only anion exchange procedures. Because the samples are so small and the technique so sensitive, contamination must be carefully avoided: all operations take place in a very clean environment.

Uranium and thorium ratios cannot be measured directly. Therefore, a tracer or "spike" of artificial isotopes of U and Th in a known ratio must be added. ²³⁶U and ²²⁹Th are used. The spike was made and its concentration and isotopic ratio calibrated against four standards of different origin. The accuracy of U ratio measurement was tested by measuring NBS U standards. The accuracy of Th ratio measurement cannot be directly tested because no Th isotopic standards are available. Instead it was tested by dating thc McMaster standard speleothem 76001.

The main calcite sample to be dated was a piece of flowstone from -15 m in a flooded Bahamian cave. The many layers of calcite deposition separated by thin coatings of mud indicate that the cave was alternately air-filled (during calcite deposition) and water filled (cessation of calcite deposition) over the last 300,000 years. The drownings occur when sea level rises. The dates on the layers of calcite immediately below and above the mud-coated hiatuses give limits on the times when sea level must have been below -15 m elevation. The periods on non-deposition indicate when sea level was above -15 m. The dates on this sample allowed the construction of a sea level curve for this area of significantly higher precision than was formerly possible. The conclusion was reached that sea level events correlate with the marine foraminiferal isotopic signature which has been fitted to an orbitally-tuned timescale. This gives strong support for the orbital geometry theory (Milankovitch cycles) of climatic change.

The second sample dated was a thermal water calcite crust from Wind Cave, South Dakota. High resolution dating of this 2 cm thick crust suggested that degassing is the principal control on sub-aqueous crust formation and revealed the behaviour of the aquifer over two glacials and one interglacial. This has been modelled in terms of aquifer recharge rate and mixing of waters of surface and deep groundwater origin.

The third sample dated was a layered stalactite from Rat's Nest Cave, Alberta, which promised to yield a record of glacial advance and retreat in the Bow Valley, Rocky mountain foothills. Dating of the very thin layers simply revealed that calcite deposition correlates with interglacial periods and hiatuses correlate with glacials. A sample with thicker layers 3nd a greater number of layers is required for closer resolution of individual advance and retreat events.

The rest of the study involved a small amount of test dating of other materials. Dating of calcite raft debris from Carlsbad Caverns gave some information on the rate cf drawdown of the water table. Dating of corals established that the technique works very well on this medium. Finally, dating of tiny samples of ostrich eggshells from the Sahara demonstrated that U-series dating may work on eggshells if they can be shown to have been closed to isotopic migration for most of their history. It also indicated that this now arid area was wetter during the last interglacial.

Mass spectrometric dating of carbonates is now established at two world centres: Caltech and McMaster. In the future it may completely replace alpha counting for Th/U and U/U dating. However, alpha counting is still the best option for Pa/U dating and other techniques which require the measurement of trace amounts of isotopes with high activities.

abstract: Doctor of Philosophy (PhD)


title: Extended end-plate beam-column joints in seismic moment resisting frames

contributor: Civil Engineering and Engineering Mechanics

subject:
Civil Engineering
Engineering Mechanics
Civil Engineering

abstract: Although moment resisting frames (MRFs) are the most widely used structural system for seismic-resistant steel buildings, several important aspects of their behaviour under real earthquake excitation are not well understood. One of these issues that needs to be further studied is the seismic performance of beam-to-column joints. During severe earthquakes, joints can undergo severe inelastic deformations affecting the strength, stiffness and inelastic action distribution throughout the frames. Therefore, the objectives of this study are to investigate the behaviour of beam-to-column joints, to assess the effect of the joints' response on the frame's overall behaviour and to provide guidelines and design rules for detailing the joints. In this thesis, attention was focused on studying the behaviour of bolted extended end-plate joints. This was achieved through an experimental-analytical research program. The experimental work carried out involved two phases. First, cyclic tests on full scale beam-to-column connections was done to examine the behaviour of such a connection type, together with the response of its individual components. Second, cyclic tests on full scale subassemblages were done to study the response of panel zones of this joint type. Based on the observation and results of the experimental program, analytical models to predict the behaviour of both the connection and the panel zone were developed. The sensitivity of these models was checked by comparing their predictions with the experimental results. The models were then incorporated into Drain-2D computer program to be used in analyzing MRFs. Analytical research on the dynamic behaviour of MRFs designed to allow active yielding of panel zone joints and to permit connection deformation was performed. Several steel MRF designs for an eight-storey and twenty-storey office buildings were analyzed using various ground acceleration records. Finally, design criteria for detailing the joints, i.e. the connection and the panel zone, and code recommendations to improve the performance of MRFs subjected to severe earthquakes were introduced.

abstract: Doctor of Philosophy (PhD)


title: Advances in yield-driven design of microwave circuits

contributor:
Bandler, John W.
Electrical Engineering

subject:
Electrical and Computer Engineering
Electrical and Computer Engineering

abstract: This thesis addresses itself to computer-aided yield-driver design of microwave circuits using implementable, efficient approximation and optimization techniques. Basic concepts of yield-driven design are identified. A number of approaches to statistical design are reviewed. Their features and limitations are discussed. The recent generalized ℓp centering approach and one-sided ℓ₁ optimization algorithm are addressed. A highly efficient quadratic approximation, specially applicable to statistical design, is presented. A set of very simple and easy-to-implement formulas is derived. This approximation technique is also applied to gradient functions of circuit responses to provide higher accuracy. A combined approach to attack large scale problem is presented, which explores the most powerful capabilities of hardware and software available to us, namely, the supercomputer, efficient quadratic modeling, fast and dedicated simulation, and state-of-the-art optimization. Yield-driven design techniques are extended to deal with tunable circuits by considering tuning tolerances. A 5-channel waveguide multiplexer is considered as an example both for the combined approach and for the treatment of tunable circuits. Yield-driven design of nonlinear microwave circuits with statistically characterized devices is considered. Relevant concepts are introduced. The efficient Integrated Gradient Approximation Technique (IGAT) is presented in the statistical design environment, which avoids the prohibitive computational burden resulting from the traditional perturbation scheme. A novel approach, called Feasible Adjoint Sensitivity Technique (FAST), is derived to calculate sensitivities of nonlinear circuits that are simulated in the harmonic balance environment. By taking advantage of the computational efficiency of adjoint analysis and the implementational simplicity of the perturbation technique, FAST is responsible for great savings of computational effort required for yield-driven design of nonlinear circuits.

abstract: Doctor of Philosophy (PhD)


title: The action of 1-Nitroso-8-Nitropyrene in Escherichia Coli: DNA Adduct Formation and Mutational specificity in the laci Gene

contributor:
McCalla, D.R.
Biochemistry

subject: Biochemistry Biochemistry

abstract: 1,8-Dinitropyrene (1, 8-DNP) is an environmental contaminant which is mutagenic and carcinogenic. In both prokaryotic and eukaryotic cells 1,8-DNP is metabolized by nitroreduction and O-acetylation to yield a nitrenium ion which binds to DNA. A metabolic intermediate is 1-nitroso-8-nitropyrene (1,8-NONP). This thesis examined the DNA adducts formed by 1,8-NONP, and the mutational specificity of 1,8-NONP in the lacI gene of E. coli. Three DNA adducts were formed in E. coli following treatment with 1,8-NONP. The major lesion (dG-C(8)-ANP), which comprised about 95% of the total adduct, was formed at the C(8) position of deoxyguanosine. It is likely that one of the minor adducts resulted from reaction with deoxyadenosine, while the other minor adduct was a product of either deoxyguanosine or deoxycytidine. The mutational specificity of 1,8-NONP was examined by cloning and sequencing several hundred lacI mutations which had been recovered from four E. coli strains which differed with respect to DNA repair background. The results suggested that 1,8-NONP induced many different types of mutations, the most prominent of which were base substitutions, frameshifts and deletions. Frameshift mutations were induced in all E. coli strains tested. However, the extent of frameshift induction was relatively low in E. coli strains proficient in nucleotide excision repair, suggesting that the premutagenic adduct(s) can be efficiently recognized and repaired by the uvrABC excinuclease. 1,8-NONP-induced frameshift mutations occurred primarily at sequences of contiguous guanine residues, and were characterized by the loss of G:C base pairs. The frameshift mutatians exhibited marked site specificity, consistent with an "incorporation-slippage" model for frameshift mutation. In some cases inverted and direct repeats might contribute to frameshift mutagenesis. The vast majority of frameshift mutations occurred at G:C base pairs, and were probably targeted by the major dG-C(8)-ANP adduct. Base substitution mutation was strongly influenced by cellular error-prone repair functions. Most of the base substitutions were G:C => T:A transversions and were probably targeted by the major dG-C(8)-ANP adduct. However, a small number of A:T => T:A transversions might have been targeted by the minor deoxyadenosine adduct. The nature of the base substitutions induced by 1,8-NONP suggests that adenine is the most comnon base incorporated during error-prone bypass of the bulky DNA adducts. The endpoints of most deletion mutations were G:C rich and contained direct repeats, consistent with a slippage model for deletion mutation. Some deletion endpoints contained sequences which were similar to the putative recognition sequences for enzymes which nick DNA during replication and repair.

abstract: Doctor of Philosophy (PhD)


title: Measurement of Particle Size in the Submicron Range - Evaluation of Liquid Exclusion Chromatography (LEC)

contributor:
Hamielec, A.E.
Chemical Engineering

subject:
Chemical Engineering
Chemical Engineering

abstract:
Herein is reported a theoretical and experimental evaluation of liquid exclusion chromatography (LEC) for the measurement of particle size distribution (PSD) and diameter averages for colloidal spheres of various compositions.

Correction factors for axial dispersion have been derived for a general detector whose signal is proportional to the number of particles time particle diameter to the power gamma (γ) where γ varies from zero to six. This general detector includes a turbidimeter (γ=6) and a refractometer (γ=3).

Equipment and operational variables and their effect on resolution were investigated experimentally. These included packing and pore sizes, bed length and carrier liquid flowrate.

The use of LEC for the off-line monitoring of the growth of latex particles was investigated for the surfactant-free emulsion polymerization of two monomer systems-styrene and vinyl acetate.

LEC can be used to quantitatively measure the size distribution and diameter averages of both organic latices and inorganic particles in the submicron range in an off-line analytical mode. LEC is sufficiently rapid for the off-line monitoring of latex particle growth in emulsion polymerization. With some modification it could be used in an online mode as a sensor for reactor control.

abstract: Master of Engineering (ME)


title: Dynamics of the ammonia laser

contributor:
Reid, J.
Engineering Physics

subject:
Engineering Physics
Nuclear Engineering
Nuclear Engineering

abstract: An experimental and theoretical study of the dynamics of NH₃ lasers is presented. The significant achievements of this work are summarized below. In initial experiments, a pulsed transversely-excited CO₂ laser operating on the 9R(30) transition is used to optically pump mixtures of NH₃ in buffer gas. A simple oscillator/amplifier system allows the performance of the NH₃ amplifier in the 11 μm region to be characterized. Small-signal gain coefficients of >10%/cm are measured on the aQ(3,3) transition at 10.8 μm, while pump conversion efficiencies of ~50% are shown to occur under saturation conditions. The NH₃ laser system is described by a rate-equation model, which is validated by comparison with experiment over a wide range of operating conditions. Measurements are made for NH₃ concentrations ranging from 0.05 to 0.2%, for Ar, N₂ and He buffer gas pressures from 170 to 700 Torr, and for gas temperatures from 200 to 300 K. Optically pumped NH₃ is shown to be a versatile and efficient system for the amplification of mid-infrared radiation. The rate-equation model is used to aid in the design of a simple and efficient NH₃ laser. This laser is tuned over more than 70 vibrational band transitions between 10.08 and 14.14 μm. Output energies greater than 1 J per pulse are achieved on several of the strongest lines. In a non-selective cavity an energy conversion efficiency of greater than 35% is obtained with a maximum output energy of 4.6 J. Optically pumped NH₃ is shown to be a flexible and efficient system for the downconversion of CO₂ radiation to the 10-14 μm region. In other experiments, it is shown that optically pumped high pressure mixtures of NH₃ in N₂ are efficient, broadband amplifiers of pulsed CO₂ radiation. In a dilute NH₃ mixture at 6 atmospheres and 200 K, a single pass gain of 150 (21.8 dB) is measured for the 10P(34)CO₂ transition. Gain is observed in NH₃ at pressures as high as 10 atmospheres. Experimental measurements are made for a range of wavelengths in the 10.7 μm region, and the results compared with calculations based on a simplified rate-equation model. The operation of a two-step optically pumped NH₃ laser (using two CO₂ lasers) is examined. Output is obtained from 16-22 μm. Experimental measurements made at 200 K and 300 K are compared to calculations based on an extended rate-equation model. As a result of this work it was shown that a single CO₂ pump laser can be used to obtain 16-22 μm lasing at 200 K.

abstract: Doctor of Philosophy (PhD)


title: Critical Behaviour of CsMnBr 3

contributor:
Collins, M.F.
Physics

subject: Physics Physics

abstract:
The critical behaviour of CsMnBr₃ has been studied by magnetic neutron scattering, magnetic susceptibility measurements, and Monte Carlo simulations. The magnetic Mn²⁺ ions in this insulating material form a simple hexagonal lattice. In the absence of an applied magnetic field me Mn²⁺ magnetic moments order in a 120º structure with the spins confined to the ab-plane.

Neutron scattering measurements of the temperature dependence of the paramagnetic critical scattering and the antiferromagnetic order parameter have found critical exponents y = 1.01 ± 0.08, ν = 0.54 ± 0.03, and β = 0.21 ± 0.02. These exponents do not correspond to any of the standard universality classes. This is a consequence of the Z₂ x S₁ symmetry of the order parameter arising from its XY (S₁) and chiral (Z₂) degeneracy.

Elastic neutron scattering has been used to determine the magnetic phase diagram of CsMnBr₃. The application of a magnetic field along the <100> direction splits the zero field transition and results in a intermediate phase (ll) of spin-flop character. The zero field transition is a tetracritical point with cross-over exponents Ψ(p-II) = 1.21 ± 0.07 and Ψ(II-I) = 0.75 ± 0.05. The fact that both exponents are less than two reflects the narrowness of the temperature range over which the intermediate phase is stable. These exponents are not in agreement with the theoretical prediction Ψ(P-II) = Ψ(II-I) ≅ 1.04.

Magnetic susceptibility (x) measurements near the tetracritical point have shown that the phase transition is marked by a discontinuous change in the slope of X. This is in contrast the predictions of scaling theory that there should be a singularity at TN where X goes to zero.

Monte Carlo simulations of CsMnBr₃ have been performed to determine to what extent the magnetic Hamiltonian is consistent with the observed phase diagram. The results reproduce the qualitative features of the phase diagram including the tetracriticality of the zero field transition and the increase of the Neel temperature with increasing magnetic field. A substantial renormalization of the Néel temperature with the size of the lattice along the c direction due to the quasi-one-dimensional nature of the system is observed. This is consistent with a strong suppression of the Neel temperature when the system is diluted with non-magnetic impurities.

abstract: Doctor of Philosophy (PhD)


title: Karst hydrogeology of the Canadian Rocky Mountains

contributor:
Ford, D.C.
Geography

subject: Geography Geography

abstract: An analysis of the discharge and hydrochemical variations of contrasting springs at Crowsnest Pass showed they were part of a vertical hierarchy in the aquifer, in which underflow and overflow components play a dominant role. It was found that karst springs at Crowsnest Pass and elsewhere show a range between two end members. Thermal springs have long, deep flow paths, with high sulphate concentrations, low discharge variance and low flow velocities. Overflow springs have local shallow flow paths, low sulphate, high discharge variance, and high flow velocities. Intermediate between these end members are underflow springs; in the Rocky Mountains these are mostly aggraded, and give the sustained winter flow and high sulphate concentrations found in major rivers. It was found that underflow or overflow behaviour is able to explain most of the contrasts found between karst springs in discharge and sulphate concentrations. Conversely, differences in bicarbonate concentration are principally due to the ratio of allogenic to autogenic recharge to the aquifer. Hydraulic analysis showed that gradients decrease in the downstream direction, and are typically 0.0001-0.05 at maximum discharges, that friction factors vary by a factor of >1000, and that most active conduits have closed-channel flow and are in dynamic equilibrium with sediment supply. The analysis of the hydrological data from Crowsnest Pass and elsewhere has led to the development of a new conceptual model for groundwater flow in karst, in which the Hagen-Poiseuille flow net conditions the aquifer for conduit development, and determines where the conduits will be. The model explains why most conduits are in dynamic equilibrium with sediment supply, why temperate karst springs are mostly vauclusian, what the mean time for speleogenesis is, how >98% of the solution of limestone is in the surficial zone, and why there are karstic hot springs in the Rocky Mountains and elsewhere. The model enables predictions to be made of sink to resurgence flow velocities, of conduit depth below the water table, of the ratio of beds to joints used by conduits, of the spacing between cave tiers, and of the depth of vauclusian springs. This new understanding of how karstic aquifers develop and function gives a powerful predictive ability to karst hydrogeology.

abstract: Doctor of Philosophy (PhD)


title: Continuous microwave excitation of excimer lamps

contributor:
Ballik, E.A.
Engineering Physics

subject:
Engineering Physics
Other Engineering
Other Engineering

abstract: For decades, microwaves have been used to create gas discharges for many applications. This thesis deals with the use of microwaves to excite gas discharges for incoherent optical sources, with particular emphasis on excimer systems. In addition, microwave excitation of a gas laser is considered. A novel apparatus was designed and built to couple 2.45-GHz microwave radiation into a gas discharge. The microwave resonator is the essential part of this equipment, and a detailed discussion of its design and performance is given. The resonator is characterized both theoretically and experimentally in order to determine the coupling efficiency and peak electric-field strength. Specialized theory is developed in order to evaluate many parameters of a microwave-excited discharge. The phenomenon of skin effect is investigated quantitatively and expressions for the plasma frequency and electron density are developed in terms of collision frequency and observable parameters (e.g., skin depth). Expressions for peak electric-field strength, ionization coefficient and collisionless electron energy are also developed. The results of an extensive investigation of continuous-wave microwave-excited excimer fluorescence are reported. Rare-gas halide, homonuclear halogen and heteronuclear halogen systems are examined and the corresponding ultraviolet spectra are presented. Truly continuous excimer emission has been achieved (for the first time) on several transitions. For systems of particular interest (e.g. XeCl and KrCl), the effects of total pressures and gas composition on fluorescence output are investigated, and the appropriate spectra are presented. Finally, the potential operation of microwave-excited carbon dioxide and argon-ion gas lasers is investigated, and upper limits are deduced for the small-signal gain under various conditions.

abstract: Doctor of Philosophy (PhD)


title: Biblical Verse Paraphrase in the English Renaissance: A Study in Literary and Social Contexts

contributor:
Roebuck, W. G.
English

subject:
English Language and Literature
English Language and Literature

abstract: This thesis examines the literary genre of biblical verse paraphrase as practised in England between 1550 and 1640, and focuses on the social setting and function of such works from the last decade of Elizabeth's reign to the Civil War. The little attention that these works have received has generally been hampered by a desire to ascertain their poetic worth rather than recognize their historical importance. This thesis attempts to redress that tendency by considering the social conditions out of which these paraphrases arose: such aspects as the publication and patronage of them, and what part they played in a poet's career; whether that career was literary, courtly or clerical. Such an approach recognizes the paraphrases as religious, social and political, as well as poetic activities. It also examines the literary context of these paraphrases: that is, not only what part they played in the individual poetic career, but how they functioned in the development of sacred poetry in English. The thesis concludes that biblical verse paraphrase, especially in the reign of King James I, was recognized as a literary task of public as well as religious importance. The thesis proceeds by considering a broad range of paraphrasers, from such well-known poets as Michael Drayton, Thomas Middleton and John Donne, to many obscure ones, some of whose work has never reached print.

abstract: Doctor of Philosophy (PhD)


title: Characterization of Human Adenovirus Type 5 Early Region 1B 176R Protein

contributor:
Branton, Philip E.
Medical Sciences

subject:
Medical Sciences
Medical Sciences

abstract:
Cellular transformation by human adenoviruses requires the expression of two early transcription units, E1A (0 to 4.5% of the genome) and E1B (4.5 to 11.2%). The products of both genes are required to disrupt normal cellular growth control and morphology. Early region 1A products alone can induce cellular immortalization, but establishment of fully transformed cells requires cooperation with E1B. Early region 1B produces two unrelated proteins, 496R and 176R, each of which can act independently with E1A to induce cellular transformation.

176R is a membrane associated protein whose molecular role in transformation is not known. Anti-peptide sera specific for the amino- and carboxy-termini of 176R were produced. These two sera were used for further purification and biochemical characterization of the protein. The 176R migrated as two species termed 18.5 and 19K on SDS-PAGE. The generation of the two species was not due to proteolysis, nor any post-translational modification investigated.

Two post-translational modifications of 176R were identified: phosphorylation and acylation. The phosphorylation site was mapped to serine residue 164, and a mutant virus in which this amino acid was altered, pm2204, was produced by oligonucleotide-directed mutagenesis. Characterization of pm2204 as well as an E1 plasmid carrying this mutation suggested that phosphorylation is not important for the biological activity of 176R. 176R was also found to contain covalently bound palmitate and myristate. Both tryptic and chymotryptic peptide mapping as well as CNBr cleavage were used to localize the acylation site. These experiments suggested that multiple acylation sites exist, and at least one site was localized to the amino terminal region by tryptic peptide mapping. The linkage of fatty acid to 176R was o found to be via an amide, or an unusually stable ester bond to an internal amino acid. Acylation of 176R likely facilitates its membrane association, but it was not possible to test this hypothesis without precise mapping of the acylation site(s) and construction of specific mutants.

abstract: Doctor of Philosophy (PhD)


title: Illness Behaviour Associated with Chest Discomfort and No Significant Cardiac Disease: A Cognitive Behavioural Approach

contributor:
Cott, A.
Psychology

subject: Psychology Psychology

abstract:
Illness behaviour is formulated within the context of the Disease Illness Distinction Model (Cott, 1987a, 1987b), a cognitive-behavioural model that is an extension or earlier disease/illness concepts. The thesis is comprised of two studies that focus on illness behaviour associated with chest discomfort and no significant cardiac disease. In the first study, the Retrospective Chest Pain Study, the incidence, nature and degree of illness behaviour were documented in 134 individuals with chest pain that was unlikely to be of cardiac origin. Results indicated a high level of disability that was attributed to chest pain, as measured by limitations on activities, changes in employment, cardiac medication intake, and visits to physicians. The nature of the disability was consistent with that reported in previous research investigating the degree of illness in individuals with chest pain and normal coronary arteries. Three conclusions were drawn from the results: Patient attributions for chest pain mediate illness behaviour and cognitions. Medication prescriptions and ingestion facilitate disease attributions and related illness behaviour. Physicians are often unaware of symptoms and related illness behaviour in their patients.

The second study, the Chest Discomfort Intervention Study, examined the utility of cognitive-behavioural interventions, based on the Disease Illness Distinction Model, in decreasing the degree of illness behaviour reported by individuals with chest discomfort and normal coronary arteries (n - 14) or mitral valve prolapse (n - 90). A second purpose was to examine the role of cognitions in illness behaviour. The cognitive-behavioural interventions were applied in both individual and group education formats, and were compared to self-monitoring attention control and wait list control groups. Results indicate that the cognitive-behavioural interventions were successful in reducing self- reported city attributed to chest discomfort and limitations on routine daily and exercise activities relative to control groups. The interventions were also more successful in shifting locus of control toward "internal," compared to controls. Fin3lly, the data indicate that while symptoms and illness behaviour appear to be related, improvements in symptoms are not necessary for reducing disability in these individuals. It was argued that the relationships identified between symptom measures and other measures of illness are medinted through cognitions regarding the significance of symptoms (e.g., "hurt" versus "harm"), rather than being the direct result of subjective characteristics of symptoms.

abstract: Doctor of Philosophy (PhD)


title: 'History and Hope': E.P. Thompson and the Making of the English Working Class

contributor:
Rempel, Richard A.
Willey, Thomas E.
History

subject: History History

abstract: The Making of the English Working Class is widely regarded as a seminal contribution to the development of post-war English historiography. Whether historians agree with Thompson's views or not, they cannot study the period 1780-1832 without paying some attention to the arguments expressed in that text. The Making also claimed the attention of socialists and sociologists since it dealt explicitly with the concept of social class. Indeed, Thompson's arguments on this question challenged, as he intended, many of the ideas then current on class and the attendant notion of revolution. Although I refer briefly to the literature dealing with the impact of The Making in the introduction, this dissertation has little to say on that subject. Instead, it inquires into the concerns that prompted the publication of the text. There has been no adequate study of the relationship between The Making and the political and intellectual context in which Thompson wrote. This is a serious omission, because the status of the text cannot be established without understanding Thompson's intentions. This dissertation hopes to go some way to filling in the gaps in the literature on Thompson's work by considering this aspect of it. A central proposition in The Making is Thompson's defence of the claim that men have the capacity to act as agents in the making of their own history. This notion, he argued, was denied by the ideologies which gave the Cold War its specificity. Marxists, in the Leninist tradition, reduced human thought to terms defined by abstract economic laws over which men had no control. Bourgeois thought similarly constrained human motives, but within a framework defined by an acquisitive and competitive conception of man's nature. In both cases human nature was assumed to be fixed and the character of this could be seen to be reflected in the existing organization of social relationships. According to Thompson, bourgeois and Marxist alike had reified a particular present and derived an eternal human nature from these abstractions. Thompson rejected this ideological conception of human nature and, following the early Marx, argued that men define their own nature through their actions. Thompson also traced this theme to the emphasis which the English Romantic critique of industrial capitalism placed on creative labour. The definition of creative labour, especially in the work of William Blake and William Morris, can be shown to have played an important role in shaping Thompson's own understanding of socialism. Thompson, in fact, drew heavily from Romanticism and integrated themes from this tradition with his own experiences in the labour movement to aniculate an original conception of socialist activity. The connection between his study of William Morris - one of his earliest and most important statements on Romanticism - and his later political and historical work, up to and including The Making, has all too often been ignored. This study focuses on this relationship in the belief that it will help one to understand some of the reasons lying behind publication of The Making. The first two chapters deal with Thompson's interpretation of the importance of English Romanticism for contemporary socialist practice. They are followed by a fairly detailed discussion, in chapters 3 and 4, of Thompson's critique of the Marxist orthodoxy that was dominant in the 1950s. Chapter 5 considers Thompson's explanation both of the sources of political apathy in post-war Britain and the factors which he believed portended socialist alternatives to the present. Chapters 6 and 7 pursue a theme introduced in chapter 2: the political significance of Thompson's history. I conclude with a general discussion of the significance which Thompson attributed to the role of creative literature, and especially to poetry, to the task of creating a socialist consciousness.

abstract: Doctor of Philosophy (PhD)


title: Spin and Parity Assignments in ⁶³Zn

contributor:
Cameron, John A.
Physics

subject: Physics Physics

abstract:
The two reactions, ⁶⁰Ni(α,nΥ) ⁶³Zn (Eα=12.0 Mev) and ⁶⁴Zn(p,d) ⁶³Zn (Ep=18.0 Mev) were studied.

Υ angular distributions and Υ-Υ coincidence yields were extracted and correlated to ascertain the ⁶³Zn decay scheme. ℓ values and spectroscopic factors were determined from DWBA fits to the neutron pickup cross sections. The following spin and parity assignments were made to the low-lying states of ⁶³Zn: E=626.5 kev (J^π=1/2ˉ,3/2ˉ,5/2ˉ), E=637.0 kev (J^π=7/2ˉ), E=650.0 kev (J^π=5/2ˉ), E=1023.2 kev (J^π=3/2ˉ), E=1206.4 kev (J^π=7/2ˉ), E=1284.8 kev (J=5/2), E=1436.7 kev (J=3/2,5/2), E=1703.8 kev (J=7/2), E=1861.6 kev (J=7/2). E=2050.8 kev (J=9/2). A level at 1392.4 kev was observed in the (p,d) experiment. The state at 1063.9 kev was observed to be a doublet, with a separation of less than 1.5 kev (J^π=7/2ˉ, J^π=(1/2ˉ)).

abstract: Master of Science (MS)


title: Seeking the Boundaries: Gerardus van der Leeuw on the Study of Religion and the Nature of Theology

contributor:
Vallée, Gérard
Religious Studies

subject: Religion Religion

abstract: Relative to his significance and his contribution to the intellectual life of the twentieth century, the thought of the Dutch scholar Gerardus van der Leeuw (1890-1950) has not been much investigated. This lack of study, along with the failure to situate van der Leeuw in his Dutch context and the failure to explore the various sides of his versatile career and vast corpus, has led to much misunderstanding of his life and thought. Van der Leeuw is most often thought of by scholars as a phenomenologist of religion - the side of his work for which he became internationally famous. Little, however, is generally know about his other pursuits, especially his devotion to Christian theology. In light of this situation, this study attempts to contextualize and investigate van der Leeuw's thought by asking the question: How did van der Leeuw conceive the study of religion, the nature of theology and their relationship? It argues that although he has been widely assumed to be principally a phenomenologist of religion, van der Leeuw should be understood first and foremost as a Christian theologian, which entails paying close attention to his virtually ignored book Inleiding tot de theologie (Introduction to theology), where he most carefully articulated his conception of Christian theology as well as his view of the integral relationship between Christian theology and the study of religion. As both a scholar of religion and a Christian theologian, moreover, van der Leeuw's conception of theology stands out - especially in terms of his view of the relationship between theology and the study of religion, which is one of the most comprehensive and sophisticated such views set forth in the twentieth century.

abstract: Doctor of Philosophy (PhD)


title: The Role of the E1b Gene Products of Adenovirus Serotype 12 in Lytic Infection and Transformation

contributor:
Mak, S.
Biology

subject: Biology Biology

abstract: It is well documented that two regions of the human adenoviruses, each encoding multiple polypeptides, are responsible for the transforming activity of these viruses and that these genes are essential for the efficient production of virus in permissively infected cells. This study was undertaken to examine the importance of the individual proteins of one of these regions from adenovirus serotype 12 (Ad12), the E1b region, in lytic infection and transformation. Molecular defects have been identified in the smaller protein, the 19K, in two of the cytocidal (cyt) mutants of Ad12. Direct evidence has been obtained demonstrating that the point mutation in the 19K of one of the mutants is sufficient to cause the degradation of DNA in infected KB cells and reduce the transforming activity of the mutant virus and perhaps its tumourigenic potential, which are characteristic phenotypes of the cyt mutants. A mutation was also engineered in the larger, 55K E1b protein and was found to impair viral DNA replication, reduce the expression of the late, structural proteins of the virus and block the inhibition of cellular protein synthesis which is normally observed upon infection of KB cells with the wild type virus. The 55K was also found to be necessary for the efficient expression of the early genes of the virus, particularly the E2b gene, which encodes essential proteins for viral DNA replication. The multiplicity dependent leakiness of the DNA replication defect of this mutant was exploited to separate the DNA replication defect from the defects in late protein expression and shut off of host protein synthesis. The observation that this mutant exhibited 1% of the transforming activity of the wild type virus but that transformants were fully tumourigenic also separated a transformation function from a tumourigenic function of this protein.

abstract: Doctor of Philosophy (PhD)


title: Sulfonated and Derivatized Sulfonated Polyurethanes for Biomedical Applications

contributor:
Brash, J.L.
Chemical Engineering

abstract:
Polyurethanes have been a material of choice for the fabrication of many conventional blood-contact devices such as vascular grafts, cardiac assist devices and total artificial hearts. Although these applications have had some success for short term applications there is a major limitation in their use for long term applications. The deficiency of the current devices and their associated materials arises from the foreign nature of these prostheses with respect to the body. Most often these devices initiate a natural physiological response that defends the body by attacking the foreign surfaces. When the materials contact with blood, the response is a series of events which lead to the eventual formation of a thrombus. In turn this often results in the dislodging of microscopic thrombi which can embolize and cause strokes.

There is therefore a need to better understand the interactions of blood with polyurethanes and to develop polyurethanes of improved blood compatibility. In this thesis the proposition is explored that improved materials may be achieved by incorporating chemical functional groups that are known to be important in the interactions of vascular and other components tending to prevent thrombogenesis. These components are the plasma proteins, the blood cells and the endothelium. Thus functional groups have been incorporated covalently into "conventional" polyurethanes as follows: (1) sulfonate groups which are an important component of the vascular wall and of the anticoagulant heparin, (2) certain amino acid moieties which are involved in the neutralization of clotting enzymes particularly serine proteases, (3) hydrocarbon chains which might be expected to bind albumin, a passivating protein, from blood, and (4) polyethylene oxide chains which might be expected to simulate the hydrogel-like nature of quiescent blood cell/plasma interfaces and which have been shown by others to minimize interactions with proteins.

The novel polyurethane materials were extensively characterized for several aspects of bulk and surface properties and response to plasma proteins. The functionalized materials were found to have greatly modified properties relative to conventional non-functionalized polyurethanes. Using differential scanning calorimetry and Fourier transform infra-red spectroscopy it was possible to associate this modified behaviour with the formation of Ionic clusters within the microdomain structures of the polyurethanes.

The different functional groups of the sulfonated and derivatized polymers allow the materials to achieve very high levels of water uptake. These elevated water levels give a hydrogel-like character to the polymers which in turn yields very low contact angle values. Furthermore, it would appear from ESCA (electron spectroscopy for chemical analysis) surface analysis data and the time dependence of sessile drop contact angle data that the material surface in air is substantially different than when the surface is contacted with an aqueous medium.

Measurements of the adsorption of fibrinogen from plasma and buffer were carried out using radiolabelling methods. The specific functionality of the different materials combine with their hydrogel-like nature to yield fibrinogen adsorption patterns in plasma that are unique and different from previously studied polyurethanes. Some of the materials were evaluated for their ability to delay plasma clotting times using standard thrombin time measurements. The results would suggest that sulfonaed and some derivatized polyurethanes may be capable of deactivating thrombin, which is a key enzyme in the formation of fibrin, the primary constituent of blood clots.

The work of this thesis makes the following contributions: (i) a general method of introducing chemical function into the hard segment of polyurethanes involving reaction of amine or hydroxyl groups with sulfonyl chloride, (ii) improved understanding of polyurethane ionomer structure. (iii) methods of controlling protein interactions and water uptake of polyurethanes by incorporation of specific functional groups.

abstract: Doctor of Philosophy (PhD)


title: Orientational Control of Chemical Reactivity in Liquid Crystalline Solvents

contributor:
Leigh, W.J.
Chemistry

subject: Chemistry Chemistry

abstract: The effect of cholesteric and smectic liquid crystalline solvent order on the regiochemical control of a thermal bimolecular reaction has been investigated. The cycloaddition reaction of cholesta-5,7-dien-3β-ylacetate with rigid enophiles has been shown to yield several 1:1 cycloadducts. The relative product yields for this reaction have been determined in a number of isotropic solvents, two cholesteric liquid crystals and a highly ordered smectic B phase. In ordered media, the relative yield of one product is enhanced at the expense of the others. The magnitude of this effect is highly dependent on the rod-like shape of the enophile and on the ordered nature of the solvent. We rationalize these results in terms of how the average orientation of the reactants within the liquid crystal influences the energetics of reaction. The enhanced adduct occurs via a transition state orientation that, compared to the other products, is much more compatible with liquid crystalline order. In ordered media, this pathway becomes energetically favoured. The largest effects on reactivity are seen when the reactants are rod-like in shape, the reactive centres are conformationally immobile and the solvent is highly ordered. This is explained in terms of how reactant shape and solvent order influence the average orientation of the solutes within the liquid crystal. It appears that more rod-like reactants are better oriented, resulting in a larger influence on reaction energetics. The more ordered smectic mesogen exerts a larger influence on regiochemical control than the more fluid cholesteric phases, presumably due to a better average orientation of the reactant(s). Activation parameters and thermal microscopy data indicate that while the orientational control of reactivity is greater in the smectic phase, the reactants may experience a heterogeneous environment.

abstract: Doctor of Philosophy (PhD)


title: Stress, Distress, and "Nerves": A Sicilian-Canadian Idiom of Distress

contributor:
Rodman, W.
Anthropology

subject: Anthropology Anthropology

abstract:
The concept of "nerves" has received considerable attention in scholarly literature. Scholars agree that the concept represents an idiom of distress -- i.e., a culturally recognized and accepted means by which individuals can communicate their pain and suffering to significant others. In the dissertation, I make use of ethnographic data, including case histories of "nerves" sufferers, to examine the extent to which this conclusion applies to the Sicilian-Canadian "nerves" complex. My findings are consistent with the views expressed by other researchers.

The phenomenon, however, is much more complex; it does not serve solely as a means of expressing distress. Among Sicilian-Canadians the concept can be manipulated, in both medical and non-medical situations, to generate a number of alternative messages. My second goal in the dissertation, then, is to examine the many meanings people attach to the term within the context of Sicilian-Canadian belief and action. I argue that the "nerves" idiom also operates as an effective impression management technique. Individuals can make use of the concept to promote or maintain a positive image of themselves within the community. At a more general level of analysis, the phenomenon allows Sicilian-Canadians to voice their discontentment with certain aspects of the immigration experience. As part of this discussion I examine how these alternative messages are linked to the "language of distress".

Since other folk concepts may also serve as idioms of distress, I have created a classificatory model that allows me to compare and contrast "nerves" with these other phenomena. The model contributes to our understanding distress idioms by facilitating both intra- and crosscultural comparison. Finally, the dissertation addresses the implications of my findings for both the general study of "nerves", and the provision of health-care to Sicilian-Canadian patients. The work, then, has both a theoretical and an applied focus.

abstract: Doctor of Philosophy (PhD)


title: Redeeming Patterns of Experience: John Montague's Text and Tradition

contributor:
John, Brian
English

abstract:
The informing and animating principle behind John Montague's critical, editorial, and creative agenda has been his unremitting search for "redeeming patterns of experience." As a Northern poet coming of age in Dublin at mid-century and bearing witness to both the Republic's far-reaching cultural revolution in the early 1960s and the reemergence of the Troubles in Ulster later that decade, Montague has sought to create for himself a fertile literary context where there had once been only acrimony and discontent, to redefine the traditions handed down to him and understand their relevance to the world at large, and to reintegrate and re-member the communities, both large and small, of which he is the self-appointed spokesman. In reassessing tradition and reformulating his context, Montague has also undertaken an ongoing revision and full-scale reordering of his body of work.

Early in his career, Montague participated in the cultural debates enforced by the tension between Joycean and Yeatsian imperatives. The rise of Liam Miller's Dolmen Press and the generation of poets it brought to attention (including Montague) acted as a mitigating and liberating force on the Irish literary scene, and helped to resolve this long-standing debate and bestride its intractable categorizations. Montague has come to fulfill his own belief: "A man's life-work can be seen as a pattern, with individual works existing not so much in themselves but as part of a total elaboration and investigation of themes .... " The multivalence of individual texts arising from their canonical reordering helps to illustrate and reinforce the creative tension between fixity and flux that informs and cements Montague's vision. The precarious atemporality of memory and the poet's mnemonic function is another aspect of this tension, yet it is also part of Montague's palliative and therapeutic art where the act of remembering, of confronting the past, history, or history's most immediate form--politics--works towards the remembering of communities as well as towards a healing of the wounds by which they have fallen into division or obscurity.

abstract: Doctor of Philosophy (PhD)


title: Ion Implantation Damage in Quartz

contributor:
Thompson, D.A.
Materials Science and Engineering

subject:
Materials Science and Engineering
Materials Science and Engineering

abstract: This thesis is a report on a series of measurements of ion-bombardment effects on α-quartz crystals. Damage was produced in α-quartz (single-crystal SiO₂) by bombarding with ions of ⁴He⁺ to ²⁰⁹Bi⁺⁺ in the energy range of 15 - 200 keV, at both 300 K and ≤ 50 K. The samples were analysed in - situ with Rutherford backscattering/channeling, using 1 - 2 MeV ⁴He⁺ ions; data was obtained from both the oxygen and silicon peaks, so that damage stoichiometry could be calculated. At low ion fluences (~ 10¹⁰ - 10¹¹ ions/mm²) the apparent damage level increases linearly with fluence, but at rates of about 3 - 19 times greater than predicted by the modified Kinchin-Pease equation. At higher fluences (~ 10¹¹ - 10¹² ions/mm²) the rate of damage increases with fluence for elastic energy deposition rates of less than :::= 0.08 eV/atom, but remains constant for greater elastic energy deposition rates. At even higher ion fiuences saturation of the damage occurs. It has been observed that the analysis beam creates damage at a rate dependent on the level of damage already present in the crystal; furthermore, the damage created by the analysis ions appears to be predominantly due to the inelastically deposited energy. Strain effects seem to greatly exaggerate the level of damage indicated by simple channeling calculations. A simple model is proposed to explain both the high rates of damage production and the non-stoichiometry of the damage. The model indicates that the effects of elastic energy deposition, inelastic energy deposition, strain produced by damage, and lattice relaxation into a '"quasi-amorphous" state. all contribute to the apparent damage levels synergistically.

abstract: Doctor of Philosophy (PhD)


title: Episodic Specialization of Classification Rules

contributor:
Brooks, L. R.
Psychology

subject: Psychology Psychology

abstract: This thesis reports research investigating the effect of practice on the operation of an explicitly stated rule. Subjects were furnished with an easy, sufficient additive rule and given practice classifying pictures of imaginary animals into two categories. Following practice, subjects showed a strong similarity effect: They were faster and more accurate at classifying positive matches (new items in the same category as the most similar old item) than negative matches (new items in the opposite category to the most similar old item), suggesting that memory for specific prior episodes played an important role in applying the rule. Subjects were not always wrong on the negative matches, and were usually immediately aware of any mistakes they did make, suggesting that the rule had not been abandoned but may have served a monitoring function. Mnemonically distinctive stimuli are probably important for episode-based responding since these effects did not occur when the items were presented as written lists of features. When subjects were stressing accuracy, and paying a large premium in response times, the negative match effect remained, while fewer than half the subjects considered similarity to old items when questioned about the cause of their errors, suggesting that the episodic information can have effects without subjects' awareness. However, a similarity strategy can be under strategic control as shown when the rule was manipulated so that information from prior experience was in opposition to the present rule information for nearly all the items. Additionally, negative matches were more disrupting if seen in the context of predominantly old items, these episodic effects were helpful when the rule was not perfectly predictive, and the classification decisions of third grade children were strikingly similar to those of the adults suggesting that children of this age group were employing a similar balance between the use of the abstract and episodic information. While some previous accounts of categorization suggest that episode-based responding is important only before subjects develop a rule or some other basis of categorization the current results suggest that, for some common types of stimuli, similarity to prior episodes may become more important with practice.

abstract: Doctor of Philosophy (PhD)


title: The Contribution of Special Expertise to the Identification of Pictures

subject: Psychology Psychology

abstract:
Determining how people identify objects and pictures in real world settings is one of the major challenges in psychology. Under normal conditions, objects and pictures are subject to an extraordinary amount of variability in perceptual characteristics. Within object categories, there are a wide variety of objects, and for any given object. there is a wide variety of possible viewing conditions. The ease with which people overcome the variability in the surface characteristics of objects and pictures is the phenomenon of interest here.

Current theories of object identification stress robust identification procedures. By the robustness view, identification proceeds by identifying reliable stimulus characteristics, and assigning category on the basis of these characteristics. Idiosynchratic, stimulus specific features are not considered a normal path to object identification. In abstractive theories of concept learning, this view of object identification is often implicit, but sometimes it is an explicit design feature of the theory. In contrast, episodic views of concept learning stress the use of prior items in categorization. Implicit in such a view is that adventitious stimulus characteristics that have been used previously to good advantage will be exploited in object identification. This is akin to Newell and Simon's view of expertise in which the expert adapts prior solutions to new problems rather than apply the same algorithmic solution again. This adaptation of prior solutions to new problems will be termed special expertise.

It is widely recognized that robust identification procedures do not exist for all object" and viewing conditions. Therefore. normal object and picture identification is a mixture or hybrid of robust procedures and special expertise. However, it is necessary to place some empirical constraints on the contribution of special expertise to determine whether special expertise is a special case reserved for unusual perceptual problems or whether it is a normal part of object perception.

The following series of experiments assesses the contribution of special expertise to picture identification by replicating and extending prior work. Additional work is reported that clarities factors potentially important to special expertise. Implications for theories of concept learning will he discussed.

abstract: Doctor of Philosophy (PhD)


title: Solar Radiative Fluxes for Realistic Extended Broken Cloud Fields Above Reflecting Surfaces

contributor:
Davies, John A.
Geography

subject: Geography Geography

abstract:
Structural properties and solar radiative fluxes for broken, inhomogeneous cloud fields (primarily fairweather cumulus) are examined from the point of view of sub-grid parameterization for global climate models (GCMs). AVHRR satellite visible and infrared radiances (256x256 km images) display almost identical one and two-dimensional wavenumber spectra. For scales greater than ~4 km, radiance spectra follow k⁻¹ to k⁻⁵/³ where k is wavenumber (at scales greater than ~40 km, radiance spectra for stratocumulus and stratocumulus of open polygonal cells behave as white noise). At scales between ~4 km and ~2 km, spectra follow ~k⁻⁴. Aircraft observations of cloud microphysics and temperature, however, suggest that these fields follow closely Kolmogorov's classic k⁻⁵/³ law down to at least ~120 m. The dramatic scaling change in radiance fields may, therefore, be due to horizontal variation in the vertical integral of liquid water content.

Based on the empirical data, a phenomonological scaling cloud field model which produces three different forms of a cloud field is developed and demonstrated. The cloud fields produced by this model are used ultimately in a three-dimensional atmospheric Monte Carlo photon transport model which is developed and validated. Also, two methods of including an underlying reflecting surface are developed and validated.

Using the models mentioned above, fluxes for various scaling, random, regular, and plane-parallel broken cloud fields are compared. Scaling cloud fields span a spectrum from white noise fields to plane-parallel. If most cloud fields scale between k⁻⁰.⁵ and k⁻⁵/³ over regions the size of GCM grids, as they probably do, neither the plane-parallel nor the random array models yield adequate flux estimates.

If a scaling cloud field with horizontally variable optical depth is transformed so that all cells with optical depth greater than zero are replaced by cells with optical depth equal to grid-averaged optical depth, reflectance is increased by 10 to 20%. This is due to the non-linearity of radiative transfer and the fact that photons are more likely to encounter liquid water in the homogenized case. Accounting for variable geometric depth of cloud may be important in warm regions where substantial towering clouds occur regularly. Also, at GCM gridbox scales it is probably just as important to account for low frequency whitish noise in cloud fields as it is to account for high frequency smoothing at scales below typical cloud cell diameter.

The convenient Lambertian surface approximation is probably adequate for most broken cloud scenarios. Expected errors in fluxes probably will not exceed a few percent. A method is developed for calculating cloudbase reflectance in a Monte Carlo simulation. For the widely used geometric sum formulae for flux calculation to be applicable, cloudbase reflectance must be independent of the number of internal reflections. For broken scaling clouds, however, this is violated. Fortuitously and fortunately, if cloudbase reflectance in the geometric sum formulae is set to the spherical albedo of the cloud field, errors in flux estimates should be small (≲ 5%) in most cases. Finally, it is shown analytically that reduction in system albedo due to the introduction of broken, non-absorbing clouds is possible but highly unlikely to occur with any importance on Earth.

abstract: Doctor of Philosophy (PhD)


title: Polymorphism in Solid 1,1,1-trichloroethane and Solid 2,2-dichloropropane

contributor:
Morrison, J. A.
Chemistry

subject: Chemistry Chemistry

abstract:
The methylchloromethane (MCM) compounds ((CH₃) in C Cl(n-4) with 0

2,2-dichloropropane has three solid phases and only one is cubic. The cubic phase is unusually stable; this may be attributable to a stabilizing influence of the surface (glass) of the sample cell. The optical birefringence results give a different view of the transitions than that deduced from existing meagre thermal data.

The information gleaned from the optical birefringence measurements had subsequently led to an extensive investigation of the thermal properties of 1,1,1-trichloroethane with a high precision adiabatic calorimeter. It has confirmed the general description of the interrelation between the different phases given here as well as the strategic role played by impurities.

abstract: Master of Science (MS)


title: Structure and Reactivity of Paramagnetic Iron Dinitrosyl Complexes

contributor:
Eaton, D.R.
Chemistry

subject: Chemistry Chemistry

abstract:
Paramagnetic iron dinitrosyl complexes have been investigated since 1968. The compounds are not easy to isolate and the majority of studies have concentrated on solution EPR measurements. As a result ambiguities remain, which concern both the geometries and electronic structures of these complexes. More recently, their catalytic properties in reactions involving the polymerization and oligimerization of olefinic compounds have been reported. Questions remain regarding the effectiveness of the complexes as catalysts, the mechanism of catalysis and the variation in catalytic activity with changes in the ligands.

This thesis reports research aimed at clarifying both the structural and catalytic chemistry of this class of compounds. The major tool used in the structural work is solid state EPR spectroscopy, although this has been supplemented by infra-red spectroscopy and X-ray crystallography. The conclusions reached favour a description of the electronic configuration which differs from that adopted by most previous researchers. The emphasis in the catalytic work has been the determination of the mechanism of polymerization. The effect of electron-withdrawing or -donating substituents on the rate of polymerization was studied. In addition, the tacticity of the polymeric products was characterized using high resolution ¹³C NMR spectroscopy. Different microstructures are predicted for polymers produced using a metal-coordinated catalyst or using free-radical, anionic or cationic initiators.

It was determined that the paramagnetic Fe(NO)₂ compounds are best described as 17-electron complexes with a d⁹, rather than a d⁷, electronic configuration on iron and a distorted tetrahedral geometry. The nature of the distortion is dependent on the type of ligands bonded to iron. When the Iigands include hard, nonpolarizable donor atoms such as oxygen or fluoride, the complex distorts towards a square-planar geometry. The spin-containing molecular orbital is predominantly dᵪ²y². When atoms such as sulfur and phosphorus are bonded to iron the geometry of the complex can be described as a trigonal bipyramid with one axial ligand missing. The dz² orbital now contains the unpaired electron. When the ligands are halides or N-bonded species, the distortions from tetrahedral are less extreme and the spin-containing MO is comprised of a mixture of d orbitals. The crystal structure of [Fe(NO)₂I₂]⁻ has been determined to be tetrahedral with a slight distortion towards the tbp geometry. This is the first example of an unrestricted complex with a tetrahedral geometry. The factors influencing these structural changes will also be discussed.

The paramagnetic Fe(NO)₂ complexes are labile in solution and one complex can often be converted to another simply by addition of excess ligand to the reaction mixture. The reactivity of these compounds is dependent on the availability of a vacant coordination site on iron, therefore the more labile complexes are more reactive, while complexes missing one ligand have significantly greater reactivity than those which are four-coordinate. The paramagnetic dinitrosyl complexes effectively initiate the polymerization of styrene. The efficiency of initiation does not depend markedly on the geometry of the complex. A mechanism is suggested in which the alkene coordinates to iron; this is followed by electron transfer which formally reduces the iron. This process creates an organic ligand which bears a formal positive charge and which subsequently participates in a cationic polymerization mechanism. This mechanism is unusual in that a paramagnetic complex is involved, but the mechanism is not a free radical one. Although the 17-electron complexes react quite well with alkenes they do not react with cyclooctatetraene or dienes such as norbomadiene and isoprene.

abstract: Doctor of Philosophy (PhD)


title: The fate of dinitropyrenes in Salmonella typhimurium metabolism and DNA-adduct formation

contributor:
Quilliam, M.
McCalla, D.
Biology

subject: Biology Biology

abstract: The nitro substituted polycyclic aromatic hydrocarbons (nitro-PAH) are a class of environmental contaminants which are potent mutagens in a number of biological test systems. The three dinitropyrene (DNP) isomers are of special interest because of their extremely high mutagenicity in the Ames Salmonella typhimurium reversion assay. Metabolic studies in S. typhimurium using both tritium labelled and unlabelled DNP demonstrated that the DNPs undergo nitro reduction and N-acetylation. Mutagenicity studies of DNP metabolites in S. typhimurium strains demonstrated that the reactive metabolite responsible for the mutagenic activity of the DNPs is at the oxidation state intermediate between nitroso-nitropyrene and amino-nitropyrene and both nitro reduction and acetylation are required for expression of mutagenicity. Efforts were directed toward synthesis of hydroxylamino-nitropyrenes (HANP) derivatives as they appeared to be likely candidates for the reactive metabolite and could be easily synthesized. The 1,8-HANP derivation was shown to produce the same covalently DNA bound adduct as that produced in vivo by the bacterial metabolism of 1,8-DNP. The 1,3-and 1,6-substituted HANP derivatives were also shown to produce covalently bound DNA adducts in vitro. Based upon the known structures of other DNA-adducts, it was postulated that these in vitro adducts were the result of bond formation between the exocyclic amino nitrogen of an amino-nitropyrene moiety and C-8 of 2'-deoxyguanosine. However, the characterization of these adducts presented many difficulties. Acquisition of UV-visible spectra of these DNP-DNA adducts was aided by coupling reverse phase high pressure liquid chromatography (RPLC) with diode array detection. The RPLC analyses of these adducts also demonstrated that they undergo extensive degradation under both acidic and basic conditions. Interpretation of their NMR spectra was difficult because of line broadening effects due to stacking of the adducts in solution. The acquisition of mass spectra of these in vitro was difficult because of their low volatility and pH instability. A number of "soft" ionization techniques such as "in-beam" ionization, fast atom bombardment (FAB), field desorption (FD), and coupled LCFAB-MS were evaluated, but only poor quality spectra were obtained. These difficulties were overcome by producing the trimethylsilyl and t-butyldimethylsilyl derivatives MS analysis of these derivatives using desorption electron ionization (DEI) mass spectrometry produced mass spectra that were rich in fragmentation ions allowing final characterization of the adducts. Finally the interaction between calf thymus-DNA and aminonitropyrene (ANP) or diaminopyrene (DAP) metabolites was studied because these metabolites were structurally similar to known DNA intercalators. The interaction of these metabolites was shown to be different than the structurally similar intercalators.

abstract: Doctor of Philosophy (PhD)


title: Production of volatile sulfides from freshwater algae and implications for the environment

contributor:
Kramer, J.R.
Geochemistry

subject: Geochemistry Geochemistry

abstract:
Dimethyl sulfide (OMS) is the major volatile sulfide (VS) species of biogenic origin released to the atmosphere. Large amounts of OMS can originate from the decomposition of the metabolic precursor Dimethylsulfoniopropionate (DMSP) in marine algae. Quantitatively, the emissions of OMS and other VS to the atmosphere are in the same order of magnitude as atmospheric sulfur from man-made pollution. Therefore the study of OMS and other VS has a significant relevance to atmospheric chemistry.

Early studies on OMS focused on the marine environment and coastal waters. The presence of other biogenic species such as H₂S, COS, CS₂, CH₃SH (MeSH), CH₃SSCH₃ (DMDS) was also detected in various types of environments including salt ponds, meromictic lakes, soils, freshwaters.

The present work is a laboratory-oriented study on the processes of formation of VS from freshwater algae. The approach undertaken is threefold: 1) Establish the presence and/or production of OMS and possibly other VS from algae cultures and surrounding lake waters. 2) Identify some key parameters influencing the formation of VS from freshwater algae. 3) Estimate the atmospheric contribution of VS from some freshwater algae and lakes.

This study showed that all species of algae and all natural waters contain OMS in amounts comparable to marine waters. However, in contrast to marine waters, OMS generally constitutes only 5 to 25% of all the sulfides, whereas MeSH usually predominates (40-80 %). H₂S+COS, CS₂ and DMDS are commonly present, whereas other species are rarely detected.

Changes in sulfate concentration had 115 significant effect on VS production by algae, but there was a threshold level of about 2 mg/L SO₄ for VS production. Cysteine also caused no significant change in VS production, but a small influence was observed with the addition of methyl donors. Methionine holds a key part in formation of methylated sulfides: additions provoked an increase of MeSH and DMDS production by up to 2 or 3 orders of magnitude.

Calculations suggest that VS from freshwater algae contribute about 115 tons S/year in Lake Ontario. This estimate is quite variable, but it is small compared to other sulfur inputs, including pollution.

abstract: Doctor of Philosophy (PhD)


title: A THEORETICAL STUDY OF THE REACTIVITY AND SYNTHESIS OF MOLECULES: APPLICATIONS AND EXTENSIONS OF THE THEORY OF ATOMS IN MOLECULES

contributor:
Bader, Richard F. W.
Chemistry

subject: Chemistry Chemistry

abstract:
This thesis applies and extends the theory of atoms in molecules to some general, important and chemically interesting subjects: a means of studying molecules of biochemical size using high-level quantum chemistry, the chemical reactivities of aromatic molecules as well as the nature of π-type hydrogen bonding.

Quantum mechanical principles define an atom in a molecule and its properties as well as the chemical bonds which link the atoms to yield a molecular structure. The resulting theory is called the theory of atoms in molecules. The theory also predicts the chemical reactivity of a molecule through the properties of the Laplacian of its electronic charge distribution, the Laplacian of the charge density also provides the physical basis of the Lewis and VSEPR models. The theory is reviewed in Chapter 1.

Molecules of biochemical interest always cause difficulties for computational chemists because of the size. Semiempirical methods have been used in the past. but must alternatively be replaced by ab initio theory. An attempt to use a nonempirical method with reliable trial functions to solve such problems, as made possible through the application of the tools provided in the theory of atoms in molecules, is presented in Chapter 2, and gives ml encouraging result.

The study of the chemical reactivities of aromatic I10lecules is of general interest to chemists. An enormous amount of research has been done in this area. A new way of using the theory to study the reactivities and energetics of monosubstituted benzenes and their para and meta protonated intermediates is presented in Chapters 3 and 4. The directing ability of a substituent and its ability to activate or deactivate the phenyl group in electrophilic substitution reaction are related to atomic, bond and molecular properties of the aromatic molecules.

The nature of π-type hydrogen bonding is discussed in Chapter 5. The molecular structures of three C₈H₈HF complexes are determined for the first time.

abstract: Doctor of Philosophy (PhD)


title: Construction of a Genetic Linkage Map of the Rhizobium meliloti 1600 Kilobase Megaplasmid pRmeSU47b, Generation of Defined Megaplasmid Deletions, and Study of Megaplasmid-Borne Genes

contributor:
Finan, T.M.
Biology

subject: Biology Biology

abstract:
A significant amount of the Rhizobium meliloti strain SU47 genome is located on two megaplasmids, both of which carry genes that are involved in the formation of N₂- fixing alfalfa root nodules. The function of most of the DNA carried by these replicons is undefined. A genetic linkage map was made of the larger of the two megaplasmids, pRmeSU47b (pEXO). The map consists of an ordered collection of transposon Tn5 and Tn5-derivative insertions encoding alternating antibiotic resistances, sequentially linked by phage ΦM12 transduction. By converting cotransduction frequencies to physical distance, pRmeSU47b was estimated to be 1600 kb in size. The positions of all known pRmeSU47b loci were determined on the linkage map: two clusters of exopolysaccharide synthetic genes, exo and exp; two separate thiamine biosynthetic loci, thi-502 and thi- 504; a locus involved in symbiosis, fix-386; genes for dicarboxylic acid transport, dct; and lactose utilization, lac.

Deletions with defined endpoints were created by recombination between the IS50 elements of transposon insertions. One additional deletion was isolated after selection for loss of the sucrose sensitivity encoded by a Tn5-B12S insertion. In all 1400 kb of pRmeSU47b was deleted. Phenotypic analysis of deletion carrying strains resulted in the discovery of several novel loci: a locus required for the formation of symbiotically effective nodules, fix114, and loci required for utilization of several carbon sources (dulcitol, melibiose, raffinose, β-hydroxybutyrate, acetoacetate, protocatechuate and quinate).

Analysis of the fix114 locus by cloning, site-directed Tn5 mutagenesis, and the isolation of active translational fusions to the E. coli reporter gene phoA revealed the size of this locus to be ca. 5 kb and suggested that it encoded extracytoplasmic protein(s). On low osmolarity solid media, fix114 mutants exhibited a mucoid phenotype which appeared to be dependent on expression of genes for synthesis of exopolysaccharide II but not exopolysaccharide I.

abstract: Doctor of Philosophy (PhD)


title: Seventeenth Century London Midwives: Their Training, Licensing and Social Profile

contributor:
Alsop, J.D.
History

subject: History History

abstract: This study is an exploration of seventeenth-century London midwives which is based, for the most part, on seventeenth-century archival sources. It is a study which challenges current and firmly entrenched perceptions of these women. The core of the thesis focuses on seventy-six midwives drawn from twelve parishes who have been examined within the context of their repective parishes. In addition, an index containing the names and other relevant information pertaining to some 900 midwives has been compiled. We will demonstrate by an investigation of the ecclesiastical licensing process, pre-licensed experience, midwives' clients, and the midwives' socio-economic circumstances, that London midwives in the Tudor-Stuart period were not incompetent and poor. Midwives were highly skilled and thoroughly experienced through their participation in a system of unofficial apprenticeship. They were, moreover, well respected both within their own parishes and by clients drawn from a broad spectrum of geographic and socio-economic settings. Many midwives were well-to-do and were the wives or widows of prosperous and influential parishioners. Throughout the seventeenth century London midwives made a valued and important contribution to the City's inhabitants who faced the perils and pleasures of childbirth.

abstract: Doctor of Philosophy (PhD)