title: Aging and Proteolysis in Cultured Human Fibroblasts

contributor:
Goldstein, Samuel
Medical Sciences

subject:
Medical Sciences
Medical Sciences

abstract:
Proteolysis of short-lived cellular proteins was investigated in early- and late-passage cells from normal donors and in cells from donors with the premature aging diseases of progeria and the Werner syndrome. Studies were conducted using intact cells or crude cell extracts to measure the degradation of cellular proteins pre-labeled for 1 hour with ³H- and ¹⁴C-Iabeled phenylalanine.

The purpose of these studies was:

1. To determine whether aging cells (late-passage normal, progeria and Werner) show increased proteolysis compared to early-passage normals as would be predicted from the Orgel hypothesis.

2. To investigate the effect of growth state and inhibitors on proteolysis in these cells.

3. To identify specific cell fractions or proteins which undergo increased proteolysis in aging cells.

4. To measure proteolysis of cellular proteins in extracts of cells, using both endogenous cellular proteases and added exogenous proteases. This was to probe the role of cellular proteins as substrates for prot eases in elevated proteolysis in aging cells.

Proteolysis was increased in late-passage normal, progeria and Werner cells compared to early-passage normal cells. This was found in growth and at confluence. The chymotrypsin inhibitor TPCK reduced the elevated proteolysis in freshly plated late-passage and progeria cells but did not have this effect on cultures growing logarithmically or those at confluence. Increased proteolysis of soluble (post-microsomal) proteins may be occurring in progeria cells but SDS-polyacrylamide gels failed to show increased turnover of any protein bands.

Protease activity in cell extracts could only be demonstrated at acid pH with endogenous cellular proteases. This proteolysis did not preferentially degrade proteins which have short half-lives in vivo including those containing the amino acid analogue canavanine. Proteins from early- and late-passage normal cells showed no difference in acid optimum proteolysis. However, proteins from progeria cells showed less proteolysis than normal controls. This was observed for labeled progeria proteins with proteases from extracts of normal or progeria cells. Paradoxically, proteins from progeria cells were more susceptible to labeled in the trypsin than normal controls but when proteins were labeled in the presence of TPCK no difference in trypsin susceptibility was observed.

The finding indicate:

1. Increased proteolysis is a feature of cellular aging.

2. Proteolysis in aging cells during growth shows greater elevation compared to early-passage normals, than that seen at confluence.

3. In progeria, cellular proteins have altered susceptibility to both endogenous and exogenous proteases.

4. The inhibitor TPCK can, under certain conditions, reduce increased proteolysis in late-passage normal and progeria cells.

Therefore, it is concluded that increased proteolysis occurs in aging cells and that increased activity of TPCK-sensitive proteases may in some circumstances be responsible. Thus, altered control of the proteolytic apparatus and not abnormal proteins may be causing increased proteolysis in aging cells.

abstract: Doctor of Philosophy (PhD)


title: Thermodynamic properties of Na-Al-O, Ni-Al-O, and Fe-Al-O systems

contributor:
Smeltzer, W.W.
Metallurgy

subject: Metallurgy Metallurgy

abstract:
Before utilizing the two phase mixture of β- and α-AI₂O₃ as solid electrolytes in oxygen probes that can monitor very low oxygen potentials, the chemical stability of β-AI₂O₃ (Na₂O, 11Al₂O₃) was studied by determining the sodium oxide activity in α-AI₂O₃, β-Al₂O₃ coexistence using electrochemical cells of the type

Pt⎮W(s), WS₂(s), Na₂S(s)⎮β- and α-Al₂O₃⎮M(s), MᵪO(s)⎮Pt

where M stands for Cu, Ni or Fe. The over-all cell reaction for these cells can be written as

W(s) + 2Na₂S(s) + MᵪO(s) = 2Na₂O(β) + WS₂(s) + xM(s)

By considering the following reaction

Na₂O (β) = 2Na(g) = ½O₂(g)

the measured values of Na₂O activity in α-Al₂O₃, β-Al₂O₃ coexistence were used to evaluate the variation of sodium vapor pressure over this coexistence, PNa(α-β), with temperature and oxygen pressure. The results indicate that PNa (α-β) reaches one atmospheric pressure at 1076°C in environments with AI, Al₂O₃(α) imposed-oxygen potentials, and at 1834°C in atmospheres with Fe,FeO imposed-oxygen potentials.

The activities of Na₂O in Al,Na,β-Al₂O₃ coexistence and β-Al₂O₃, β"-Al₂O₃ equilibria were also determined using the following cells

Ta⎮Al(s or ℓ), Na(ℓ)⎮β-Al₂O₃⎮NiO(s),Ni(s)⎮Pt⎮Ta,

and

Pt⎮W(s), WS₂(s), Na₂S(s)⎮β- and β"-Al₂O₃⎮Ni(s), NiO(s)⎮Pt,

respectively. The results obtained as well as the available thermodynamic data in the literature for the Na-AI-O system were used to partially represent the equilibrium oxygen pressure diagram of Na-Al-O system at 1000K.

To establish the reliability of using the two phase mixture of β- and α-Al₂O₃ as a solid electrolyte in oxygen probes, galvanic cells using solid electrolyte tubes fabricated from this mixture with electrodes of fixed oxygen chemical potentials were developed. Experimental results indicated that this solid electrolyte responded reversibly to oxygen potentials as high as those of Cu, Cu₂O equilibria between 600°C and 1000°C, and as low as those of Al-α-Al₂O₃, β-Al₂O₃ coexistence between 550°C and 800°C.

The thermodynamics parameters and phase compositions in the Ni-Al-O and Fe-Al-O systems at temperatures in the range 850°C-1150°C have been also investigated using electrochemical technique, electron microprobe analyses, and X-ray powder diffraction studies. Results showed that, about one ppm of Al in Ni or Fe is sufficient to stabilize α-AI₂O₃. Electrochemical cells with calcia stabilized zirconia as solid electrolyte and working electrodes of the type Ni (or Fe)-AI alloy Al₂O₃(α) had shown electrical instability which was not amenable to correction by coulometric disturbance or by temperature cycling. When β- and α-Al₂O₃ solid electrolyte was used in combination with Ni (or Fe)-AI,AI₂O₃(α) electrodes, steady and reproducible potentials were measured at 940°C which enabled the equilibrium oxygen pressures over these electrodes to be calculated. The values obtained for the oxygen pressures were outside the electrolytic domain of calcia stabilized zirconia which explain the instability problems of cells with this electrolyte.

Quantitative results have been obtained for the phase compositions in the ternary systems Ni-AI-O, and Fe-AI-O. These resuIts have been used to construct the 1000°C Ni-AI-O isotherm, and to modify and extend the NiO-Al₂O₃ quasibinary system given previously in the literature. The equilibrium oxygen pressure diagrams of the Ni-AI-O and Fe-AI-O systems have been constructed at 1000°C based on the results of this investigation as well as the available data in the literature.

abstract: Doctor of Philosophy (PhD)


title: The Gracious Gods and the Royal Ideology of Ugarit

contributor:
Combs, A. E.
Cooper, A. M.
Religious Studies

subject: Religion Religion

abstract:
This dissertation presents a new interpretation of the enigmatic Ugaritic text CTA 23. This study is supported by a critical transliteration and translation of the text, together with detailed textual and philological notes. A history of interpretation is included to indicate both areas of consensus and of disagreement concerning the meaning and purpose of the text.

The study indicates that CTA 23 must be understood in the context of the ancient Ugaritic concept of kingship. It substantiates this perspective by demonstrating that there are numerous points of contact between CTA 23 and the royal ideology reflected in the epic texts from Ras Shamra. Like the kings and royal progeny in the legends of Keret and Aqhat, the ᵓilm nᶜmm are the offspring of deities and are nursed by goddesses. These gods, who are invoked and honoured in the text, are identified with princes. The interest shown in the circumstances of their birth indicates that the text and its underlying ritual served as a royal apologia. The solicitude for royal parents and offspring that is reflected in CTA 23 suggests that the text's Sitz im Leben was a royal liturgy designed to ensure the well-being of royal figures.

abstract: Doctor of Philosophy (PhD)


title: An Investigation of Nuclear-Cytoplasmic Relationships in Skeletal Muscle Fibres of Mouse Chimaeras

contributor:
Peterson, Alan C.
Medical Sciences

subject:
Medical Sciences
Medical Sciences

abstract:
Nature mammalian myofibres are multinucleated elongate cells in which the nuclei are regularly distributed along the entire length of the cell. The multinucleated condition arises by the fusion of mononucleated myoblasts to form myotubes during primary development. A fundamental and essentially unexplored problem in muscle cell biology is the question of the nuclear-cytoplasmic relationship in muscle fibres. Although local membrane specializations occur, most notably in the region of innervation, it is not known if each myonucleus controls the biochemical functions of a local territory comprised of the immediately adjacent muscle cytoplasm, organelles, and membrane, or if the gene products of every myonucleus are uniformly distributed in the fibre. An understanding of this aspect of the organization of muscle cells could help solve other problems in the biology of skeletal muscle; for example, what is the significance of X-chromosome mosaicism in the expression of muscle disease problems in the biology of skeletal muscle; for example, what is the significance of X-chromosome mosaicism in the expression of muscle disease in carriers of X-linked myopathies? Which myonuclei are the targets of neurotrophic influences on muscle?

In this study I have taken advantage of the fact that in mouse chimaeras two genotypically distinct types of myonuclei are often incorporated into single myofibres skeletal muscle cells in vivo. Mouse chimaeras were produced by the aggregation of embryos homozygous for different alleles for both the monomers of the cytoplasmic enzyme glucosephosphate isomerase (GPI-1) and the monomers of the nuclear-coded mitochondrial matrix protein malic enzyme (MOD-2). Therefore, mosaic myofibres contained both Gpi-1ª/Gpi-1ª, Mod-2ª/Mod-2ª myonuclei and Gpi-1ᵇ/Gpi-1ᵇ, Mod-2ᵇ/Mod-2ᵇ myonuclei.

The distribution of the electrophoretic variants of GPI-1 was measured at various points along the length of mosaic muscle fibres. Changes in the isozyme composition along the length of a cell would indicate that the enzyme remains localized in cytoplasmic territories. A uniform isozyme profile would result if the products of individual myonuclei are homogeneously distributed. The results presented here indicate that the intracellular distribution of GPI-1 isozymes does not change along the length of mosaic myofibres in both adult and young mouse chimaeras. Therefore, the products of each myonucleus are widely distributed in skeletal myofibres.

Functional GPI-I is an oligomeric enzyme composed of two monomers. Analyses of the proportions of GPI-I dimer types in mosaic myofibres reveal that the homogenous distributions of GPI-I isozymes arise by the widespread distribution of precursors of GPI-I (monomers or monomer precursors such as messenger RNA) before dimer formation; dimers are not initially assembled in local territories around each myonucleus and then widely distributed.

The investigation was extended to the question of whether individual mitochondrion in skeletal myofibres have access to nuclear-toded proteins encoded by one or by multiple myonuclei. Evidence was obtained that indicates that both types of monomers of nuclear-coded mitochondrial malic enzyme (MOD-2) are present in an individual mitochondrion of a mosaic myofibre.

The results indicate that the gene predicts of different myonuclei are widely distributed both before the assembly of cytoplasmic oligomeric proteins and before the incorporation of proteins into mitochondria.

Taken together, the results obtained in this study constitute direct evidence that mammalian skeletal myofibres are functional syneitia in which the gene products of many myonuclei are distributed throughout each cell. Problems and possibilities regarding the mechanisms of distribution and the nature of the gene products distributed are discussed.

abstract: Doctor of Philosophy (PhD)


title: A Comparative Psychophysiological Study of Normal Subjects, Psychoneurotic Patients and Patients with Irritable Bowel Syndrome

contributor:
Campbell, D.
Medical Sciences

subject:
Medical Sciences
Medical Sciences

abstract: A broad overview of the irritable bowel syndrome (IBS), with an emphasis on theoretical problems, is followed by a comparative psychophysiological study of normal subjects, psychoneurotic patients and patients with IBS. All subjects had a psychiatric interview and psychometric testing followed by measurement of activity in the rectosigmoid colon during baseline, neutral interview, stressful interview and following a meal or neostigmine (0.5 mg I.M.). Myoelectrical activity was recorded from two intraluminal bipolar suction electrodes (4 cm apart); motor activity was recorded from two intraluminal strain gauges at the same sites. The number and duration of contractions per minute were determined by inspection of the motor activity record; the frequency content of both the motor and myoelectrical records was determined using a Fast Fourier Transform (FFT) computer assisted method. Measurements were also made of severity of pain following varying degrees of distension of the rectosigmoid colon, serum gastrin and motilin levels and heart rate responses. The two patient groups were psychologically similar to each other and more disturbed than normals both at psychiatric interview and on psychometric measures of anxiety, depression and neuroticism. The IBS patients were significantly different from the neurotics only on the lie scale of Eysenck Personality Inventory (p < .05). The ratings of pain to distension of the sigmoid colon were not significantly different in the three groups (p >.05). The ISS group did not differ significantly from the neurotic group on any of the physiological measures (p >.05); during baseline the ISS group had a greater number and duration of contractions than the normals at one recording site (p <.05). We conclude that previous reports of physiological characteristics unique to ISS have resulted from a failure to control for relevant psychological characteristics and from recording and analysis deficiences. A behavioral model, capable of accounting for both the experimental findings and observed clinical features, is described.

abstract: Doctor of Philosophy (PhD)


title: Rational Price Expectations and Small Macroeconomic Models

contributor:
Scarth, W.
Economics / Economic Policy

subject: Economics Economics

abstract:
The purpose of this study was to analyze -- both theoretically and empirically -- the effects of various models of inflation expectations formation on aggregate supply relationships, and the small scale macroeconomic models of which they form an integral component, from the point of view of information availability, modelling, and estimation. One model of inflation expectations formation in particular, rational expectations, has important implications for macroeconomic modelling and, more specifically, the tradeoff between inflation and real output.

The basic theory of rational expectations is reviewed and various problems with its empirical implementation are discussed. The properties of alternative models of expectations formation are compared. Furthermore, some direct evidence on the nature of expectations formation in active auction markets for financial instruments is presented.

Expectations by their very nature are unobservable and thus one confronts a joint hypothesis problem in the interpretation of any results using a proxy specification. To circumvent this difficulty, Monte Carlo simulation experiments with a representative small macroeconomic model are undertaken. This allows a comparison between rational and other models of expectations formation under varying -- but known -- model conditions.

Inherent in most models of expectations, and particularly for rational expectations, is the assumption that market participants possess a considerable degree of foresight with respect to information market structure, and parameter values. As an alternative, a time dependent approach to modelling with a minimum of information priors is developed and applications to real income, expected inflation and the demand for money are discussed.

abstract: Doctor of Philosophy (PhD)


title: The Use of Jewish Scriptures in Qumran and Paul as a Means of Self-Definition

contributor:
Sanders, E. P.
Religion

subject: Religion Religion

abstract:
The aim of the thesis is to examine the use of Jewish scriptures in connection with the self-definition of the Qumran community and the early church. The working hypothesis is that self-definition and scriptural interpretation were reciprocally conditioning factors in both, Qumran and the early church. That is, on the one hand, each group found itself described in the scriptures and justified its own practices and beliefs by citing them. On the other hand, the scriptures conditioned the way in which each group understood itself. Doctrines and practices were both justified by scripture and developed with dependence on it. While numerous aspects of doctrines and practices will be explored, the thesis will focus on the question of how each group's understanding of itself as the right, and the only right group was both defended by proof texts and modified by the texts cited.

There has been extensive research done on the relationship between Jewish scriptures, Qumran and the New Testament. However, very little of this work has been directed toward the study of self-definition in Qumran and the early church.

The thesis is of general significance for the broader study of religion in two ways: it addresses a significant topic in Judaism and Christianity and thus enables a fruitful comparison to be made; it bears on the question of how groups forge and modify their own self-definition.

abstract: Doctor of Philosophy (PhD)


title: On the elastic interaction of plate-shaped precipitates

contributor:
Purdy, G.R.
Metallurgy and Materials Science

subject:
Materials Science and Engineering
Metallurgy
Materials Science and Engineering

abstract:
The influence of the elastic interaction energy of plate-shaped precipitates causing tetragonal distortion on nucleation, growth and coarsening is considered.

The analysis shows that the elastic interaction energy may be minimized by the formation of regular three-dimensional arrays, which emphasize the "edge-face" configuration. Algebraic conditions of stability against coarsening are developed, and the results of the detailed numerical test of stability against coarsening for a particularly simple and symmetric array are reported. Experimental observations on θ" (Al-3%Cu alloy) microstructures show strong evidence of short-range ordering, with two characteristic configurations (edge-face and "parallel-step"), both energetically favourable.

It is shown that the elastic interaction energy may have a decisive role in the nucleation stage of θ' preoipitates. The θ' microstructure, in a relatively early stage of development, is often inhomogeneous and consists mainly of linear (parallel inclined and cross-like) stacks.

Numerical calculations of the elastic interaction energy show that the experimentally observed stacks are energetically favourable, and can be generated in an auto-catalytic way. Numerical and preliminary experimental results on the stability against growth and coarsening of elastically-locked linear arrays are reported.

Finally, the chemical driving force and elastic retarding force acting on moving ledges on a planar interphase boundary are considered. It is shown that elastic interaction may cause a departure from the local equilibrium at a moving growth ledge, and may dictate the location of "homogeneous" nucleation of growth ledges. Some experimental results concerning ledge nucleation and ledge interaction are reported.

abstract: Doctor of Philosophy (PhD)


title: Immunological Studies of Chicken Brain: Isolation, Purification, and Localization of a Neural Specific Protein CNA-1

contributor: Medical Sciences (Growth and Development)

subject:
Medical Sciences
Medical Sciences

abstract:
The differentiation of any cell leads to the synthesis of certain proteins which are responsible for its specific function. In the nervous system this includes such functions as the conductance of action potentials, synaptic transmission and the establishment of specific connections. The developmental biology of proteins unique to the nervous system is therefore of great importance when studying the relationship of proteins to physiological function.

Although some neural specific components of adult chicken brain and their ontogeny in the chicken embryo have been previously described by others, they have not been extensively characterized. The present investigation was undertaken in order to enumerate, characterize and study the embryological appearance of antigens specific to the adult chicken brain that can be demonstrated by rabbit anti-brain sera. Particular interest was given to the isolation and purification of one such neural specific antigen in hopes of further elucidating its role in adult function and embryonic development.

Antiserum produced in response to a saline soluble extract of adult chicken brain (ABE), when absorbed with adult liver, serum and kidney extracts, yielded a neural specific antiserum (AABS). This polyvalent antiserum was capable of demonstrating at least eight adult neural specific antigens within ABE during immunoelectrophoret analysis. The sequential appearance of seven of these antigens during embryonic development (D2 to D11 of incubation) was established. An eighth antigen could not be detected within the embryonic brain extracts and was assumed to be associated with posthatching neural development. By immunochemical criteria, the majority of the neural specific antigens, but not all, were demonstrated to be restricted to avian brain. Similarly the majority of these antigens, but not all, were demonstrated to be protein in nature since reactions with trypsin and chymotrypsin resulted in loss of antigenicity.

Separation of the antigens within ABE, based on their net ionic charge and molecular weight, was attempted with each resulting fraction being analyzed by immunoelectrophoresis. One neural antigen (CNA-1), possessing alpha-1 globulin mobility was isolated from the other neural specific antigens. This thesis further describes a procedure developed for the purification of CNA-1, utilizing ammonium sulphate fractionation, ion exchange chromatography, gel filtration chromatography and preparative polyacrylamide gel electrophoresis. Highly sensitive and quantitative immunochemical techniques (crossed and fused rocket immunoelectrophoresis) were employed in monitoring the purification steps.

Studies on the purified antigen revealed it to be homogeneous by a number of criteria, having a native molecular weight of 65,000 daltons as determined by molecular exclusion chromatography and possessing two identical subunits (MW 30,000) as determined by SDS polyacrylamide gel electrophoresis. The structure of CNA-1 was concluded to be protein on the basis of its sensitivity to trypsin and chymotrypsin.

Immunochemical studies utilizing a monovalent antiserum to CNA-1 revealed the protein to be avian specific and not present in brain extracts of mammalian species. Also both a high (> 1,500,000 daltons) and low (65,000 daltons) molecular weight component which shared the CNA-1 antigenic determinant were observed, indicating possible aggregation of the protein during the isolation procedure.

CNA-1 was first detectable by the seventh day of incubation and continued to accumulate during the period of embryonic neural development in which both neurogenesis and synaptogenesis are known to occur. Within the adult chicken cerebellum, CNA-1 was specifically localized to the cell surfaces of particular neuronal cell types (i.e. Purkinje cells, granule cells and neurons of the deep cerebellar nuclei) by immunohistochemical techniques. Glial elements were not labelled.

Organ specific brain antigens have been described by different investigators. The antigen described within this thesis appears to be completely different from all others described in the literature as revealed by a study of its physical and chemical properties. The function and role of CNA-1 on the cell surface remains to be elucidated. Its localization on specific cell types suggests that it may be associated with inhibitory synaptic function. For this reason, further study of CNA-1 may prove to be important in unravelling some of the questions concerning cell-cell interaction and neuronal specificity during development of the central nervous system.

abstract: Doctor of Philosophy (PhD)


title: The Development of Doctrine: A Study in Bernard Lonergan's Method in Theology

contributor:
Robertson, John C.
Religion

subject: Religion Religion

abstract:
Can Catholicism's claim to permanent and normative truths be reconciled with the changes in that religion brought to light by modern historical-mindedness? Such a question frames the modern problem of doctrinal development. The argument of this thesis is that the method in theology developed by Bernard Lonergan contributes much to the clarification and solution of this problem.

The thesis is divided into two parts. Part One introduces the problem of doctrinal development and examines the context of Lonergan's approach to the problem. The first chapter analyzes the French Modernist Alfred Loisy's position on doctrinal development. It is shown that the modern problem of doctrinal development turns on the issue of synthesizing the normative and the historical elements of doctrine; and it is argued that such a synthesis must be grounded in theological foundations appropriate to historical-mindedness. In the remaining two chapters Lonergan's contribution to the formulation of such foundations is discussed: his analysis of the transition from classicism to historical-mindedness (Chapter Two) and his development of transcendental method (Chapter Three). This discussion provides the context for our analysis of Lonergan's position on doctrinal development.

Part Two addresses in detail Lonergan's efforts to synthesize the permanent and the historical elements of doctrine. Chapter Four traces changes in Lonergan's reflections on doctrinal development over the past forty years, showing that the basis for his affirmation of the permanence of doctrine has altered significantly with changes in his understanding of the method and foundations of theology. Chapter Five examines Lonergan's Christian Philosophy, showing how transcendental method provides a basis for the synthesis of the permanent and historical in doctrine. And Chapter Six discusses how the method and foundations of theology proper to Lonergan's notion of functional specialization can provide for a viable mediation of the permanent meaning of a doctrine through varying cultural and historical contexts. On the basis of the foregoing analysis there follows a response to several criticisms of Lonergan's affirmation of the permanence of doctrine.

The argument of this thesis is of value in three related areas of scholarship. First, the thesis addresses students of Lonergan's thought by showing the strengths and possible shortcomings of his theological method with respect to the specific problem of doctrinal development. Secondly, the thesis addresses Catholic theologians by illustrating the significance of Lonergan's method in theology for problems arising out of Catholicism's engagement with modern historical-mindedness. Thirdly, the thesis addresses students of modern Western thought by elucidating Lonergan's efforts to work out the foundations for modern historical-mindedness in general and a historically-minded theology in particular.

abstract: Doctor of Philosophy (PhD)


title: Language Development In Premature and High Risk Children

subject:
Language Development
Premature high risk children
Medical Sciences
Medical Sciences

abstract: With advances in neonatal intensive care, many infants born at risk due to very low birthweight (1500 grams or less), due to intrauterine growth retardation (the small-for-gestational age infant has a birthweight less than 2 SD below the mean for gestation) or due to severe Respiratory Distress Syndrome and birth asphyxia, survive free of major debilitating sequelae. However, these apparently 'healthy' children may experience difficulties in perceptual, cognitive and academic performance. The early language development of 12 'healthy' children potentially at risk due to their pre- and perinatal histories, and a group of comparison children matched for sex and social class was investigated. Their language was recorded at home at three monthly intervals during a rapid phase of acquisition (18 to 30 months), to determine whether the two populations were acquiring language similarly. Of further interest was the ambient linguistic environment provided by their mothers. The language measures, derived from the child's spontaneous speech, quantified verbal output (rate and amount of speech), syntactic complexity (mean length of utterance, upper bound and type-token ratio) and morphemic acquisition. Comprehension and expressive scores were also derived from the Reynell Language Scales. The mothers' speech was scored for verbal output and syntactic complexity. The high risk children were as verbose as the comparison children, but their language was syntactically less complex. Their comprehension scores were also significantly lower. Although the high risk scores (uncorrected for the degree of prematurity) were within normal range, they were still significantly below those of the comparison children. This, along with the fact that the language of the two groups of mothers did not differ, and the fact that social class was not a significant factor, supports the position that maturational delay and/or cortical lesion may affect language acquisition. Other issues discussed included the propriety of applying a correction for prematurity to the results, and whether the results are evidence of a developmental lag, or a continuing disability likely to affect other emerging skills. Finally, this study provided correlations between language measures derived from spontaneous speech, and those from standardised language scales.

abstract: Doctor of Philosophy (PhD)


title: Free Radical Chemistry of αHydroperoxydiazenes Synthetic Applications And Mechanistic Studies

contributor:
Warkentin, John
Biology

subject: Biology Biology

abstract:
The Structure of the products of autoxidation of hydrazones were first established in the early 1950's. Although those compounds have been known for many years, relatively little is known about their chemistry. Recent reports indicate that they can be used as oxidizing agents for a number of organic substances and as sources of hydroxyl and carbon-centered radicals. The free radical chemistry of the title compounds is the main subject of this thesis.

Alkyl(1-hydroperoxyl-1-methylethyl) diazenes (28) [(CH₃)₂C(OOH)N=NR:a, R=CH₂CF₃; b, R= CH₂CH₂OCH₃ c, R=CH₂CH₂OC₆H₅; e, R=CH(CH₃)₂; f, R=C(CH₃)₃; g, R= CH₂C₆H₅] and phenyl (1-hydroperoxyl-1-methylethyl)-diazene, 28d, were prepared in solution by autoxidation of the corresponding hydrazones of acetone. these compounds show broad bands between 3600 and3200 cm⁻¹ in their infrared spectra. The intensities of the bands decrease at different rates with decreasing hydroperoxydiazenes concentrating indicating the presence of hydrogen-bonded species.

Themolysis of 28 in enol ethers produces carbonyl compound; thus 28b decomposed in 1-ethoxyethylene (ethyl vinyl ether) and in 2-methoxypropene to give 4-methoxypropene to give 5-methoxy-2-pentanone, respectively. yields ranged between 50% and 70%. In some alkenes the compounds decompose to give alcohols. For example, 28a decompose in 1,1-diphenyl-4,4,4-trifluorobutanol.

Other alkenes, particularly those that are highly hindered, give hydroalkylation products and epoxides. For Example, decompostition of 28a in bicyclo[2.2,1]hept-2-ene (norbornene), leads primarily to formation of 2-(2,2,2-trifluoroehtyl) norbornane and exo-2,3-epoxynorbornane.

The reactions of 28 in olefinic substrate involve free radical intermediates. Product formation takes place via radical chain hydroxylalkylation and radical chain hydroalkylation. The chain-initiation step involves the unimolecular decomposition of the hydroperoxydiazene to give alkyl and hydroxyl radicals with concomittant formation of nitrogen and acetone.

In the case of hydroalkylation , the first chain-propagating step involves addition of the alkyl radical to the double bond. The adduct radical so formed the chain-tranfers by inducing the decomposition of 28 at the hydroperoxyl oxygen. According to this mechanism, the first-formed products from enol ethers are hemiacetal and hemiketals which do not survive the reaction conditions but decompose to the corresponding carbonyl compounds.

In hydroalkylation reactions, the sterically crowded alkyl radical, formed by the addition of R to the hindered alkene, propagates by abstracting the hydroperoxyl hydrogen to generate α-azoperoyl radical and alkane. The peroxyl radical, in the next, adds to the alkene and the adduct β-peroxyalkyl radical undergoes intramolecular induced decompostion by γ-scissors to give the epoxide. In less reactive, and in hindered alkenes, additions seem to be slow and that leads to very poor yields of epoxide.

Evidence for the mechanisms is presented and discussed.

abstract: Doctor of Philosophy (PhD)


title: High Temperature Sulfidation Properties of Fe-Al Alloys

contributor:
Smeltzer, W.W.
Metallurgy and Materials Science

abstract: The sulfidation properties of the Fe-Al alloys containing 6, 9, 18 and 28 atomic percent Al were investigated in alloy/FeS diffusion couples, in sulfur vapour at the dissociation pressure of the FeS and in H₂S+H atmosphereat 1173K. The reaction kinetics were determined thermogravitmetrically and by layer thickness. measurements. The reaction specimens were analyzed using light microscopy, X-ray diffraction and electron metallographic techniques (SEM, EPMA) along with EDAX spectrometry. Particular interest was given to the mode of precipitation and growth of sulfide phases. Diffusion coupling of Fe-Al alloys with FeS in the form of compacts results in periodic precipitation of sulfide (FeS+FeAl₂S₄) bands in the alloy. The thickness of sulfide bands increases with depth satisfying the Jablczynski's relationship for Liesegang type of precipitation process. The initial stage of sulfide band formation is explained by a model involving precipitation of Al₂S₃which is subsequently converted to FeAl₂S₄. Growth of each sulfide band or layer is supported by raid diffusion of iron and aluminum in the FeS phase. It is suggested that aluminum depletion from the alloy in the front of a sulfide layer ultimately leads to its cessation of growth. A new sulfide band begins to form at a distance ahead of the sulfide layer. where the concentration product for the precipitation of Al₂S₃ is satisfied. The mode of precipitation of sulfide changes from bands parallel to the original alloy surface to the platelets normal to alloy surface when Fe-6, 9 and 18 Al alloys are sulfidized in sulfur vapour supplied by a mixture of Fe and FeS. The acicular internal sulfide precipitates of FeAl₂S₄ and Al₂S₃ in these alloys are elongated in the growth direction. Their growth is interpreted by a model involving enhanced sulfur diffusion along the incoherent interfaces between the internal sulfides and alloy matrix. The alloy composition at which transition from the internal to external scale formation of Al₂S₃occurs, is calculated using available models and compared with the experimental results. Fe-9 Al alloy sulfidizes parabolically in H₂S+H atmospheres giving rise to a scale consisting of an outer Al-doped FeS layer, an inner FeS+FeAl₂S₄ layer and Al₂S₃+alloy internal precipitation zone. the Fe-18 Al alloy is sulfidized by a two-stage kinetics. In the initial stage, growth of the FeS+FeAl₂S₄ nodules is observed accompanied by the internal sulfidation beneath these nodules. The final stage of the reaction curve commences when an inner film of Al₂S₃ forms at the external scale/alloy interface. Models based upon diffusion and the thermochemistry of the sulfidation reactions are advanced to account for the reaction kinetics and sulfide morphologies. The ternary Fe-Al-S isothem is determined experimentally and it is used to interpret the scale microstructures which grew by parabolic kinetics.

abstract: Doctor of Philosophy (PhD)


title: Influence of the Stress State on Various Fracture Modes

contributor:
Embury, J.D.
Metallurgy and Materials Science

abstract:
The influence of superimposed pressure on the damage accumulation processes leading to various tensile fracture modes has been studied on axisymmetric samples of different materials.

For ductile fracture damage accumulated in both smooth and notched tensile samples had been characterized in a variety of spheroidized steels tested under superimposed pressures ranging from 0.1 MPa to 1100 MPa by counting the number of voids existing at the cementite-iron interfaces and measuring their area fraction. A quantitative model accounting for the size dependence of void nucleation has been developed to describe these results.

The shear fraction mode has been investigated by performing tensile tests on an Al-Zn-Mg alloy under superimposed pressures up to 1100 MPa. The pressure does not affect the onset of shear bands, but changes their growth as it opposes and dilational damage created in the bands. This allows the occurrence of the further plastic deformation process to take place. The microscopic observation of the shear bands, but changes their growth as it opposes any dilational damage created in the bands. This allows the occurrence of the further plastic deformation to take place. The microscopic observation of the shear bands has revealed that they are created by structural softening events, and that they involve a complex spatial correlation of crystallographic slip events over the entire cross-section.

Brittle fracture has been studied in both Al-Au and Fe-P alloys, displaying intergranular fracture and transgranular cleavage. The pattern of microcrack development and the changes in fracture modes have been characterized for these two alloys.

Finally, two types of fracture maps in stress space are presented, where the various fracture mechanisms are represented by lines, and which can also be used as damage contour maps. These maps are constructed either by considering a complete model of damage accumulation and fracture criterion, or simplified analytical relationships to express damage development and occurrence of failure.

abstract: Doctor of Philosophy (PhD)


title: Metabolic Studies of N⁶-(²- Isopentenyl)Adenosine in Normal and Autonomous Tissues of Nicotiana tabacum L.

contributor:
Hall, R.H.
Biochemistry

subject: Biochemistry Biochemistry

abstract:
The nucleoside, N⁶-(Δ²-isopentenyl)adenosine (i⁶Ado) stimulates growth and differentiation of lines of tobacco callous tissue grown in culture. The nucleoside is extensively metabolized by the plant tissue. The hypothesisis been advanced that the expression of growth and differentiation is due to the interaction of some or all the metabolites of i⁶Ado rather than due to i⁶Ado alone or one of its metabolites.

To study this hypothesis, the metabolism of i⁶Ado was followed in two lines of tobacco callous tissue. One line, KX, required the presence of i⁶Ado and auxin for growth, the second line, an autonomous line, 0-1, required neither hormone for growth. Both lines metabolized [8-¹⁴C]i⁶Ado, yielding a mixture of 12 metabolites, 9 of which were identified. Quantitatively the two patterns of metabolism differed. The principle product in the KX tissue was ribosylzeatin, whereas in the 0-1 tissue it was N⁶-(Δ²-isopentenyl) adenosine.

The effect of other plant hormones, auxin and abscisic acid an the metabolism of i⁶Ado was studied. Auxin had no effect on i⁶Ado metabolism on 0-1 tissue, but in KX tissue it depressed the rate of uptake. Abscisic acid caused a change in ratios of i⁶Ado metabolites in KX tissue, but not in the autonomous tissue.

These data do not prove or disprove the hypothesis mentioned above, they do indicate, however, that a varied pattern of metabolic products of i⁶Ado are formed in normal tobacco callous tissue.

abstract: Doctor of Philosophy (PhD)


title: The Ecophysiology of Surface Cryptogams from Alpine Tundra and Semi-Arid Grassland of Southwestern Alberta

contributor:
Kershaw, K.A.
Biochemistry

subject:
Ecology and Evolutionary Biology
Other Ecology and Evolutionary Biology
Ecology and Evolutionary Biology

abstract:
The seasonal response patterns of net photosynthesis and respiration (and nitrogenase activity in Nostoc) are described within a multivariate framework of temperature, moisture and light for the alpine and grassland crustaceous lichens Rhizocarpon superficiale and Caloplaca trachyphylla respectively and for the grassland surface cyanophyte Nostoc commune. These physiological responses are discussed in context of each species' boundary layer environment, with particular emphasis placed on interactions between environmental constancy and adoption of acclimation strategies.

For R. superficiale the high frequency of thermal fluctuations experienced by hydrated thalli, sometimes on an hourly basis, precluded any strategy of seasonal acclimation. Instead, photosynthetic rates exhibited a broad temperature response, remaining near 1 mg CO₂ h⁻¹g⁻¹ from 1 up to 21°C, with no changes evident between seasonal responses. In marked contrast C. trachyphylla shows a distinct winter/summer pattern of photosynthetic acclimation. In winter months rates are optimal near 7°C, while in summer the temperature optima of net photosynthesis shift to 21°C. These changes correlate well with predictable seasonal microclimate events, particularly those associated with winter Chinook snowmelt periods. A third pattern of response was seen in N. commune, where no seasonal changes in response patterns were evident and both nitrogenase activity and net photosynthesis were maximal near 35°C. This response pattern allows maximum carbon gain and nitrogen fixation during spring and summer periods following precipitation events, while its more sheltered aspect reduces the importance of winter snowmelt periods.

abstract: Doctor of Philosophy (PhD)


title: Photophysics of the Phenylnaphthalenes and Binaphthyls: Evidence for Conformers

subject: Biology Biology

abstract:
The simple biaryls 1- and 2- phenylnaphthalene 1, 1' - ,1,2'- and 2,2'-binaphthyl may, in principle, exist as distinct molecular conformers differing chiefly in their rotational configuration about the interannular bond. The steady-state fluorescence and fluorescence decay spectroscopy of these molecules in dilute solution has been examined for evidence of such single bond rotational conformers.

While the fluorescence of 1-phenylnaphthalene originates from essentially a unique molecular conformation in fluid solution or in rigid organic glasses at 77K, singlet decay measurements of 2-phenylnaphthalene at 295K and 77K indicate the presence of at least two emissive components. This is confirmed by the emission spectroscopy at low temperature and by the effect of selective oxygen quenching on the room tmeperature fluorescence. In a polycrytalline matrix of methylcyclohexane at 77K the 2-phenylnaphthalene molecule appears constrained to a single, more planar conformation.

Of the binaphthyl only the 2,2'-isomer exhibits complex fluorescence behaviour in the fluid hydrocarbon solvents, the spectrum showing a distinct excitation wavelength dependence while the fluorescence decay can be best analyzed as the sum of long and short lived exponential decays. Molecular Oxygen was used to enhance these spectroscopic differences, differentially quenching the longer lived conformer of 2,2'-binaphthyl. The Shpol'skii (polycrystalline) emission spectrum of this compound at 77k indicated the presence of spectroscopically distinct conformers different from those seen in fluid media and separated by ~525cm⁻¹ in their fluorescence origins. 1,1'- and 1,2'- binaphthyl, while giving no evidence of confromeric fluorescence at 295K did give a biexponential fluorescence decay in organic glasses at 77K.

These studies suggest that relatively stable single bond conformers may be more ubiquitous than is generally supposed. Where these conformers differ spectroscopically the technique of fluorescence emission and decay spectroscopy may be successfully applied in conjunction with the selective quenching techniques.

abstract: Doctor of Philosophy (PhD)


title: "The Balance Wheel of the Industrial System": Maximum Hours, Minimum Wage, and Workmen's Compensation Legislation in Ontario, 1900-1939

contributor:
Sheriff, Peta
Sociology

subject: Sociology Sociology

abstract: Recent attempts to extend Marx's analysis of capitalism by developing a class-based theory of the role and functions of the capitalist state have turned on the debate between the "instrumentalist" and "structuralist" perspectives. Subsequent critiques and extensions of these two conceptions of the relations between the state and the major classes within capitalist society have raised the issues of the role of class struggle in the development of state structure and policy as well as the impact of the capitalists state itself on the nature of class relations. Although theorists have pointed to the mutually conditioning effects characterizing the relationship between the state and social classes, there has bee little empirical examination of this relationship. The precise nature of the kinds of mechanisms linking various social classes and the state together with the concrete effects of these links on state and class relations required further specification. In response to this significant gap in the development of the theory of the capitalist state, the present research was formulated to address the issue of specifying the forms of mediation between the state, industrial capitalists and labour through an analysis of the history of maximum hours, minimum wage, and workmen's compensation legislation in Ontario between 1900 and 1939. These areas of legislation were chosen because of their significance, for both capitalists and workers; they represent a potential drain on accumulated surplus for owners of capital and a potential improvement in subsistence and working conditions for labour. The development of legislation in each of these areas thus provided a focus for examining relations between owners of industrial capital, wage labour, and the state. The major sources of data for the primary analysis covering the period from 1900 to 1939 consisted of private papers, published and unpublished government documents located in the Public Archives of Ontario and the Public Archives of Canada, labour newspapers, and the journal of the Canadian Manufacturers' Association. The analysis of relations between workers, employers, and the state around limitations on working hours, minimum wage regulation, and the establishment of a workmen's compensation program identifies a number of modes by which capitalist domination in the workplace is mediated to the level of political relations. These modes of mediation function through mutually reinforcing economic, political and ideological forms and have as their primary effect the frustration of the political organization of labour as a class. Capitalist modes of mediation are parallelled and supported by the modes of mediation adopted by the state in its role of managing class relations. In the process of the development of the areas of legislation which are the focus of this study, the state functioned to maintain the hegemony of capitalist social relations of production by transforming the economic class struggle and processing labour demands in such a way that subsequent state policy and structure were guided in the direction of comparability with prevailing class relations of domination and subordination.

abstract: Doctor of Philosophy (PhD)


title: Characterization of the Transforming Poteins of Adenovirus Type 5 Synthesized in Infected Human Cells and Transformed Hamster Cells

contributor:
Graham, Frank L.
Biology

subject: Biology Biology

abstract:
It is known that human adenovirus type 5 gene products will cause the conversion of primary cells to a potentially oncogenic state. The transforming gene resides in a 4050 base pair (bp) region (early region 1; E1: 0-11.2 map units, mu) at the left end of the physical map of the linear duplex DNA genome (ca. 37,000 bp). Early region 1 is organized into two transcription units, E1A (0-4.5 mu) and E1B (4.5-11.2 mu), each of which produces multiple species of mRNAs and polypeptides. The results of studies on a libraryof baby hamsters kidney cell lines transformed by the adenoviral DNA fragments representing all (XhoI C:0-16 mu) or only a part (Hind III G:0-8 mu) of E1 established that the E1-58 product was unnecessary for both maintenance of the transformed state and oncogenicity. It was further shown that although mutants defective for 58K expresion are transformation deficient in the virion mediated transformation assays, the DNA extracted from these mutant viruses possessed transforming activity comparable to wt in in vitro DNA transfection assays. The mutant transformed hamster cells lines which emerged from these experiments fid not express the 58K product but exhibited a range of oncogenic potentials in newborn hamsters similar to wt transformed lines.

Hamster anti-tumor serum and a rabbit serum specific for a synthetic peptide corresponding to the carboxy terminus of the E1A proteins were used to identify E1A proteins (52K, 50K. 48.5K, 37.5K, 35K, 29K, AND 25K) and E1B proteins (19K and 58K) in infected and transformed cells. Interestingly, the few batches of anti-tumor sera positive for E1A products all recognized only a subset (52K, 48.5K, 37.5K) of the E1A proteins corresponding to the products of only the largest of the E1A mRNAs. These immunoreagents were used to study the deposition of transforming proteins by cell fraction and indirect immunofluoresence techniques. The E1B-19K was resolved into two related cytoplasmic membrane associated polypeptides (19K and 18.5K) neither of which were detected on the outer surface of the plasma membrane. The E1B-58K appeared to accumulate in the nucleus during the lytic cycle. E1A products localized in both nuclear and cytoplasmic compartments and, within the cytoplasm, these proteins showed a marked affinity for the cytoskeleton.

By examining the kinetics of early protein synthesis during lytic infection of KB cells by wild type (wt), it was shown that E1A, E1B, E2 (61.6-74.9 mu) and E4 (91.4-99.1 mu) proteins were expressed in a temporal relationship. Infectious with the E1A host range (hr) mutant hr3 were characterized by severely depressed levels of early protein synthesis consistent with the proposed role of E1A gene products as activators of early transcription units. The normal pattern of expression was also perturbed by a defect in E1B as the E1B host range mutant hr6 showed generally delayed and reduced levels of early gene expression suggesting a role for E1B gene products in the efficient expression of early genes.

abstract: Doctor of Philosophy (PhD)


title: "The Signes of Heaven to Ken": Astrological Lore and Spenser's The Shepheardes Calender

contributor:
Cain, T.H.
English Literature

subject:
English Language and Literature
Literature in English, North America
English Language and Literature

abstract: This thesis argues that Spenser's handling of character, situation, and theme throughout The Shepheardes Calender corresponds to the traditional significant of the planetary and zodiacal governors of the twelve eclogues. The introductory chapter outlines some fundamental principles of the two astrological traditions relevant to the present study, traditions that I have loosely called Ptolemaic or "scientific" and Neoplatonic, and explains that the lack of horoscopal information about the characters constitutes no serious barrier to my approach. To avoid the repetition that would result from organizing the study around zodiacal zodiacal signs, i have used a planet-by-planet approach. Chapter I analyses Colin Clout's past achievements and his present predicament in terms of two distinct but related conceptions of Saturn and melancholy: its main argument is that Colin's early accomplishments align him with a benevolent Saturn and with what Yates calls inspired melancholy (based ultimately on the "Aristotelian" Physical Problems XXX), the early Venus leads him in a contrary direction, and the frustration of this Venerean impulse makes him a victim of the malevolent Saturn of popular asrology. Chapter II argues that in "Februarie", ruled by Jupiter, a mean between Saturn and Venus, the confict between the malevolent Saturn and the earthly Venus reappears in the debate between a Saturnian Thenot and a Venerean Cuddie, and that since all figures in the debate and the tale are "failed Jupiters",the conflict ends in a deadlock aptly corresponding to the fact that the fish in Pisces move in the opposite direction, but within the same element, and are bound by a common cord. In "November", however, Dido is a true Jovial figure, and the Jovial aspect of the eclogue's context temporarily dispels Colin's Saturnian gloom and cooperate with the benevolent Saturn to lift Colin's mind "above the starry skie", a movement appropriate to the significations of the centaur-figure Saggitarius. Chapter III shows that Spencer accommodates Mars in his Calender: by parodic reduction on "March" and by evoking Mars in "October" to point beyond the pastoral to his projected epic. The Venus inherited by the Renaissance represents a vast range of ideas about love and beauty, from the basest carnality through to the principles of cosmic harmony and the most mystical expressions of love for God. Chapter IV discusses the correspondence between several of these significations and the eclogues for Venus' two signs, Taurus ("April") and Libra ("September")" in addition to discussing Golin's misadventure in love, this chapter demonstrates "April's" suitability for a celebration of the encomiastic poet; discusses the manifestations of Venus that are in harmony with the benevolent Saturn; examines Eliza's role as a Venus figure presiding over an idyllic natural, political, and poetic environment in contrast to to the iron age of the framing dialogue; and shows that although the world Diggon describes in "September" is the antithesis of that depicted in the "April" ode, Roffyn in actuality, and Hobbinoll and Diggon in potentiality, represent the forces (seen as another Saturn- Venus combination) that can effectively reconstruct the world in imitation of the peace, harmony, justice, mercy, friendship and liberality of the "April" ode. Chapter V examines Mercurial motifs in "Maye" and "August": the stress in "Maye's" debate on the duties and responsibilities of the clergy, particularly with respect: to worldly wealth and to preaching ability and'debating skills, is suitable to Mercury's rulership, as is the emphasis on 'fraud, deceit, and wealth in Piers' tale; Mercury's gift of verbal skill and dexterity is manifested in both the roundelay and the sestina in "August". Since the sun signifies things spiritual, while the moon is an age-old symbol of material mutability, "Julye" appropriately deals with ecclesiastical matters and "June" with secular; the two eclogues are complementary discussions of the moral and practical problems for the poet and priest of prominence or aspiration. Chapter VI shows that Spenser handles the themes of prominence and aspiration in ways suitable to the celestial governors of these eclogues: the sun and Leo are consistently associated with the ambitious or pre-eminent and with the perils and temptations besetting them, so "Julye's" debate covers these subjects and provides a 'catalogue of notable men; the most wellknown properties of the moon and Cancer (e.g., the moon's inconstancy and its shining by borrowed light and the sun's reversal of direction in Cancer) do not augur well for any ambitious impulse, so in "June" neither speaker is ambitious and Colin provides a bewildering series of rationalizations to justify his loss of aspiration. The concluding chapter suggests some possibilities for further study.

abstract: Doctor of Philosophy (PhD)


title: Neuropharmacological Analysis of the Mechanism of Action of L-Prolyl-L-Leucyl-Glycinamide (PLG) in Relation to Movement Disorders

contributor:
Mishra, Ram K.
Medical Sciences, Neurosciences

subject:
Neuroscience and Neurobiology
Pharmacology
Neuroscience and Neurobiology

abstract:
Centrally active peptides have increasingly been implicated in diverse neuro-psychiatric disorders in humans. Although several clinical studies have attested to the therapeutic potential of L-Prolyl-L-Leucyl-Glycinamide (PLG) in Parkinson's disease, no unifying hypothesis concerning its mode of action can be formulated. The present critical analysis of the pharmacological property of PLG was predicated on the hypothesis that there exist putative receptor sites of PLG manifesting differential modulatory effects on dopaminergic neurotransmission.

The action of PLG was examined in behavioral paradihms reflecting dopamine dependent extrapyramidal motor dysfunction: haloperidol-and morphine-induced catalepsy in rats. Chronic, but not acute, treatment of PLG significantly antagonized hoth morphine and haloperidol catalepsy.

The influence of PLG on in vitro dopamine receptor function was evaluated, and the resutls showed that PLG selectively enhanced the affinity of the specific binding of the agonist H-apomorphine to doapmine receptors in rat striatum. PLG, however, failed to alter ³H-spiroperidol binding in vitro.

A radioligand binding assay was developed to identify specific putative binding sites of PLG in normal rat and human brain. ³H-PLG bound to membrane homogenates from both human and rat striatum with high affinity and in a saturable manner. The regional distribution profile of the specific ³H-PLG binding demonstrated that human substantia nigra exhibited thehighest level of ³H-PLG binding sites, followed by the striatum and hypothalamus. In the rat brain, the striatum was highly enriched with PLG binding sites. Pharmacologically active analogues of PLG completed for specific ³H-PLG binding with relative potencies paralleling their in vitro biological activities.

The potential anti-dyskinetic activity of PLG was evaluated in the pharmacological animal model of tardive dyskinesia. In rats, PLG, when administered concurrently with haloperidol of chlorpromazine, antagonized the enhancements in specific ³H-spiroperidol binding in the striatum as associated with chronic neuroleptic treatment.

The results of the present study support the hypothesis that putative PLG binding sites are functionally coupled to dopamine/neuroleptic adenylate cyclase complex and raise the issue as to the feasibility of specific peptidergic dysfunction and peptide replacement therapy in neuro-psychiatric disorders.

abstract: Doctor of Philosophy (PhD)


title: Oxidation Properties of Fe-Al Alloys at 1173K

abstract: The oxidation properties of Fe-Al alloys containing 1.5,3,4,5,7,8,12,16,20 atomic percent aluminum were investigated in dry oxygen, wet oxygen, laboratory air and alloy/(Fe+FeAl₂O₄+Al₂O₃) diffusion couples at 1173K. The reaction kinematics were determined thermogravimetrically and by layer thickness measurements. The reacted specimens were analyzed using light microscopy, electron metallography, x-ray diffraction, Auger electron spectroscopy and Mössbauer spectroscopy. Particular interest was given to the growth of Al₂O₃on these alloys. A duplex external scale consisting of Fe₂O₃at gas/scale interface, (Fe,Al)₃O₄ at scale/subscale interface and a subscale of FeAl₂O₄ platelets with Al₂O₃tips grew on alloys containing up to 5 a/o Al oxidized in dry oxygen. The growth of the FeAl₂O₄-Al₂O₃ platelet precipitates, which is interpreted by a (Fe,Al)₃O₄/Al (alloy) solid state displacement reaction, is controlled by oxygen diffusion torugh the subscale in the very early stage of oxidation. A oxidation continues, the oxygen pressre at the scale/subscale interface decreases due to increase of aluminum concentration of (Fe,Al)₃O₄ by dissolution of FeAl₂O₄ precipitates. The diffusion outward from the bulk alloy plays and important role as the velocity of precipitation front decreased by decreasing oxygen activity which leads to the development of a continuous Al₂O₃film at the subscale front in Fe-5 a/o Al alloy and isolation of the subscale from the alloy substrate. Multilayered scale consisting of Fe₂O, Fe₃O, FeO+Fe₃O, FeO+FeAl₂O₄ and subscale grew on alloys containing up to 5 a/o Al alloy oxidized in air or wet oxygen. The FeO+FeAl₂O₄ layer and subscale grew by inward oxygen migration generated by dissociation of wustite. The high rate of oxygen transfer inward with hydrogen generated by dissociation of water vapour, accelerated the oxidation processes and did not allow aluminum diffusion outward from the bulk of the alloy to affect the oxidation behavior. For Fe-7 and 8 a/o A alloys, a thin duplex scale was formed consisting of Fe₂O₃ layer at oxygen/scale interface and Al₂O₃ layer at scale/alloy interface. An oxidation model was advanced to describe the scale, development involving iron diffusion through leakage paths in the Al₂O₃ formed initially to form Fe₂O₃ layer at the scale/gas interface. Only the Al₂O₃ is formed on Fe-12, 16 and 20 a/o Al alloys. An oxidation mechanism is proposed based on inward oxygen diffusion down the grain boundaries and outward aluminum diffusion to account for the formation of hollow nodules in the scale. Alloys containing 3, 5, 7 and 8 a/o Al oxidized internally when coupled with (Fe+FeAl₂O₄+Al₂O₃) mixture. The Fe-3 a/o Al alloy oxidized linearly but the Fe-5, 7, and 8 a/o Al alloys at internal oxidation zone/alloy interface. However, an Al₂O₃ film was formed at (Fe+FeAl₂O₄+Al₂O₃)/alloy interface with no internal oxidation in Fe-12 a/o Al alloy diffusion couple. Alloy composition at which transition from internal to external scale formation of Al₂O₃ occurs, is calculated using available models and compared with the experimental results.

abstract: Doctor of Philosophy (PhD)


title: Microanalytical Study of Discontinuous Precipitaton in Aluminium-Zinc Alloys

abstract:
This thesis treats the discontinuous mode of precipitation in Al-22 and 28 at .8 Zn. High resolution STEM x-ray microanalysis has been used to measure the composition profiles in individual depleted lamella formed under isothermal conditions. These data, combined with local values of cell velocity and interlamellar spacing, have been used to evaluatethe kinetic and thermodynamic quantities of main concern. It is shown that the reaction is grain boundary-diffusion controlled and depending of individual grain boundary characteristics. The driving force for grain boundary migration and possible free-energy sinks are discussed. The results are compared with predictions of existing theories.

The problem of the optimal interlamellar spacing is addressed, mainly from the experimental point of view. Experimental data for Al-Zn and Mg-Al alloys are analyzed and related to the discussion.

The problem of the optimal interlamellar spacing is addressed, mainly from the experimental point of view. Experimental data for Al-Zn and Mg-Al alloys are analyzed and related to the discussion.

It is demonstrated that initiation involves diffusion induced grain boundary displacements, and that during the growth process a significant amount of elastic energy is stored in the product phases. The dissolution of the reheated lamellar structure is volume diffusion-controlled.

abstract: Doctor of Philosophy (PhD)


title: Participant Values in System Development

contributor:
Welke, Richard J.
Management Science/Systems

subject: Management Information Systems

subject: Management Sciences and Quantitative Methods

subject: Management Information Systems

abstract:
A value is the concept of the desirable. If those who develop information systems and those who use information systems have different values, the value gap can lead to serious consequences. Two methods are developed and tested in this thesis to measure the value systems of developers, users and other participants in the information system development process: one based on a personal value questionaire (PVQ) and the other based on multi-attribute value theory (MAVT).

A framework for information systems (IS) relevant values was developed to enumerate and organize the values to be measured into three groups: economic, technical and socio-political-psychological.

There were 86 values enumerated, which were used in the PVQ method to survey 132 system developers and 47 47 system users in 13 firms. Developers and users were found to have similar values with respect to economic and technological items but sharply differing values in the socio-political-psychological group.

A condensed set of items consisting of two economic, five technological and four socio-political items, were organized in a hierarchical struture, for the MAVT method. Preference conditions were assessed and values were measured using the rating scale approach. Three subjects were interviewed in depth; two produced additive multi-attribute value functions, while one produced a multiplicative function

abstract: Doctor of Philosophy (PhD)


title: LIMITATION OF EXERCISE PERFORMANCE BY ACTIVITY OF INTRACEREBRAL DOPAMINERGIC SYNSPSES

contributor:
Coates, Geoffrey
Health Sciences

subject:
Medicine and Health Sciences
Medicine and Health Sciences

abstract:
Evidence from the literature suggests that a limiting factor to the performance of exhaustive exercise is the ability of the brain to maintain the stimulation of the alpha-motor neuron. This these examined the hypothesis that this "central fatigue" results from a deficit in the transfer of information across striatal dopaminergic synapses. Decreases in striatal dopaminergic activity should impair exercise capacity whereas increases in dopaminergic activity should therefor improve exercise capacity. The rat was chosen as the experimental animal because of the availability of techniques to alter dopaminergic activity and to quantify exercise capacity. Striatal dopaminergic activity was reduced by depletion of striatal dopamine by an intracerebroventricular injection of 200mg of 6-hydroxydopamine. Dopaminergic activity was increases by an intreperitoneal injection of the specific dopamine receptor agonist apormorphine. Exercise capacity was quantified with treadmill-grid system by measuring the time taken for a running rat to become exhausted. Striatal dopamine depletion decreased exercise capacity whereas apomorphine increased xercise capacity. In contras, striatal and hpothalmic norepinephrine depletion had no effect on exercise capacity.

The limitation of exercise capacity by the activity of striatal dopaoinergic synapses was not due to a failure of these synapses to maintain the release of dopamine, but may be due to these synapses releasing amounts of dopamine which are insufficient to transmit all the information arriving at the presynaptic terminal to the postsynaptic neuron. I propose that the release of dopamine is limited in exhausted rats by the activitation of presynaptic dopamine receptors located on the terminal and that the purpose of these receptors is to maintain the concentration of dopamine in the functional pool of the terminal.

abstract: Doctor of Philosophy (PhD)


title: The Rhetoric of Revenge The Use of Forensic Rhetoric in The Spanish Tragedy, Titus Andronicus and The Jew of Malta

contributor:
Duncan, Douglas
English Literature

subject:
English Language and Literature
Literature in English, British Isles
English Language and Literature

abstract: The thesis examined is that the authors of The Spanish Tragedy, Titus Andronicus and The Jew of Malta are making a case for and against the protagonist as in a revenge trial, not as it would be conducted in an Elizabethan court, but as it might be constructed from the works of the Roman rhetors studied in the schools. The method is first to consider the advice given to orators by the Roman rhetors most commonly studied in the schools, which reveals that they emphasise the forensic oration and the dramatic quality of rhetoric, and all give instructions for conducting a case of revenge. Secondly, examination of the system of teaching rhetoric in Elizabethan schools supports the probability that rhetorical precepts would be applied to writing plays. Thirdly, scholarly opinion suggests that forensic rhetoric was already employed in pre-Elizabethan drama, although not in the form of a trial. Lastly, consideration of Elizabethan opinions on blood revenge suggests that its legal status as criminal homicide may have appeared over-simplified to a generation trained in the Roman rhetors' view of revenge as an issue meriting an equitable decision according to the circumstances of the case. This inference is supported by the sophisticated defence provided for the revenger in the plays which would not have been available in an Elizabethan court. Analysis of the plays according to the precepts revealed by the background material indicates that many structural, persuasive and argumentative features of The Spanish Tragedy and Titus Andronicus conform to the rhetorical techniques of the revenge trial. The same method of analysing the elements of the revenge trial apparent in The Jew of Malta highlights Marlowe's variations on Kyd's approach. The most important of these is his argumentative method which employs the resources of both rhetoric and logical dialectic to turn consideration of the case of the revenger into an attack on the audience.

abstract: Doctor of Philosophy (PhD)


title: The Motivational Bases of Voluntary Action

contributor:
Carment, D.W.
Heshka, Stanley
Social Psychology

subject:
Social Psychology and Interaction
Social Psychology and Interaction

abstract: Five Investigations were conducted to examine the antecedents of participation in voluntary organizations. The objective of these studies were to identify factors which influence the decision to become a volunteer. While much prior research has been devoted to this subject, his series is distinctive insofar as it examines a broader range of potential determinants, employs longitudinal panel designs and directs particular attention to individual differences in the circumstance, the events and the psychological stares which precede voluntary action. In the first study, the reasons advanced by individuals to account for their decision to volunteer were examined employing open-ended interview questions and rating scale measures. Consistent with prior research, it was observed that most persons had more than one reason for volunteering. However, application of two statistical reduction techniques revealed that these reasons tended to be given in clusters and that there were three main purposes for joining: (1) Advancements of Career and Personal Goals (2) Social and Situational Compensation (3) Altruism The second study was designed to explore the relationship between social background factors and the reasons for undertaking voluntary action. This investigation demonstrated that persons with similar social backgrounds often pursue voluntary action for similar purposes. The analysis revealed that students often participate to obtain career experience while unemployed persons and those recently experiencing major life events (e.g. retirement, loss of spouse, change in parental responsibilities), were more likely to volunteer in order to meet people, relieve boredom, and find purpose in life. In addition, while most persons mentioned a desire to help others among their reasons for volunteering, only retired or full-time employed respondents with situational stability (i.e., no recent life events) accentuated the altruistic purpose of their actions in their explanations. These results suggest that social background factors may influence the perceived utility of such pursuits and influence the reasons why people volunteer. Study three examined the amount of social encouragement to volunteer received by various types of initiators. This investigation revealed that young individuals, persons with less formal education and first time joiners were especially likely to have been persuaded to join. Conversely, elderly persons, those experiencing recent major life events and individuals with previous volunteer experience were considerably less likely to have been persuaded. While prior research has shown that social encouragement is frequently associated with the initiation of voluntary action, this study is the first to assess which types of joiners were most likely to receive encouragement to volunteer. The fourth and fifth study of this thesis examined the relationship between attitudes toward voluntary action and participation in instrumental voluntary organizations. Study four assessed whether attitudes were predictive of joins which took place after various temporal delays. Attitudes were found to be excellent predictors of participation initiated within one to eight months of an attitude measure, but progressively less predictive of joins occurring after longer delays. Moreover, it was also discovered that attitudes tend to be better long-range predictors when the join was not preceded by a life event and when the individual undertook participation to promote organizational goals rather than personal objectives. Finally, a three part investigation was conducted to examine the extent to which attitudes change when individuals become volunteers. Part one was a two-year longitudinal study which demonstrated that attitudes toward voluntary action became significantly more favourable when individuals joined voluntary organizations and significantly less favourable when such activities were terminated. In part two, it was observed that this attitude change occurred before the individuals had joined the organization and changed little once participation had begun. Finally, part three of this investigation indicated that attitudes toward voluntary action generally became more favourable only after the individual had decided to become a volunteer. The implications of these findings with respect to the role of attitudes in the decision to volunteer are discussed. Throughout these studies, individual differences in the determinants of these activities were repeatedly noted. It is crucial that investigators direct increased attention to these differences in the development of their models of volunteer motivation. To assist in this regard, a model is presented which accommodates individual variation in the antecedents of participation and provides a conceptual framework in which to consider the significance of various antecedents of this phenomenon.

abstract: Doctor of Philosophy (PhD)


title: Separated Double Chord RHS Joints

contributor: Civil Engineering and Engineering Mechanics

subject:
Civil Engineering
Civil Engineering

abstract:
The central focus of research undertaken concerned the strength and behaviour of separated double chord rectangular hollow section (RHS) K-joints. Peripherally the concepts of the twin member shear beam is introduced as a simple and inexpensive bridging for revealing the intrinsic structural properties of such joints.

The finite element method has been used to investigate the stiffness characteristics of the separated joint. The RHS chord member is idealized by a thin plate representing the inner web and a channel representing the top and bottom flanges and the outer web. The stiffening effect by the channel is incorporated through its condensation into a boundary stiffness matrix to be added to the inner web stiffness matrix.

The proposed finite element formulation includes rectangular plate elements in the inner web plate and a variety of beam elements in the channel forming grillage. The formulation considers both bending and in-plane actions. Material nonlinearities of the joint are assumed to be adequately represented by the Von Mises yield criterion and the associated plastic flow rule. While geometric nonlinearities have been excluded, this was deemed reasonable for the range of displacements considered in this study.

To verify the finite element model, a number of experiments were conducted on twin shear beams with the objective of making definitive statements about the joint performance to be anticipated for the finite element model. Twenty-four specimens were tested in the Applied Dynamics Laboratory of McMaster University. Test results showed a definite improvement in structural performances for both increased depth and a decrease in the gap.

From experimental result, a local deflection limit criterion was suggested to define a range of permissible displacements in double chord joints. Such a criterion was based upon that presented in the literature for single chord joints.

A verification of the finite element model was made using the experimental data of the twin shear beams and it exhibited good correlation. A model of sensitivity analysis was then carried out with the objective of furthering understanding of the behaviour of such structural components.

The model was extended to the general model called EPAC-RHS (Elasto-Plastic Analysis of RHS Connections). In the process of this extension, triangular plane stress-plate bending elements were introduced to accommodate an arbitrary joint assembly of K and N configuration. In addition, member preloads were accounted for in EPAC-RHS.

Theoretical results of simulated K-joint models were compared with experimental data of K-joints obtained from the literature. While strength predictions were somewhat conservative, very good agreement of elastic response was observed for all tests.

A yield line theory was developed for which two strength models, trapezoidal and conical were proposed. Their predicted strengths were compared with experimental loads at the limiting deflections suggested. Good agreement with the tests was found particularly for the trapezoidal model. The twin shear beam models were then extended to be applicable to K-joints by taking into account both the reduction in strength due to chord axial preload and the horizontal component of the diagonal force. Theoretical results were compared with previous experiments on K-joints and exhibited reasonable correlation.

abstract: Doctor of Philosophy (PhD)


title: Language Acquisition in YOung Boy and Girls in Relation to Manual Motor Function and Laterality

subject:
Medical Sciences
Physiological Processes
Medical Sciences

abstract: Language acquisition in relation to sex, manual motor skill and laterality was studied in forty-nine middle class normally developing children. A longitudinal design was employed and testing was done at 18, 24 and 30 months of age. Measures of language function, motor function, lateral asymmetry and general cognitive ability were used. It was predicted that: (a) girls would perform better than boys on the language measures, (b) children who scored high on manual motor tasks would talk better, (c) handedness would not be related to language ability, and that, (d) handedness and motor asymmetries would be observed at 18 months and not change at 24 and 30 months. The girls performed better than the boys on almost all the language measures. There were no sex differences for any of the other tests given. A weak association was found between manual motor skill and language productivity, but handedness and language ability were not related. Hand preference and motor asymmetries were observed at 18 months and maintained at 24 and 30 months. These results further our understanding of language development in young children and may help the assessment and treatment of children with developmental language problems. The measurement of handedness and lateral behaviors in young children permits inferences about hemisphere specialization in the young child. The results of this research support the position that hemispheric specialization does not develop with age but is present from a very early age.

abstract: Doctor of Philosophy (PhD)


title: Physical adsorption of simple linear molecules on graphite

contributor:
Morrison, J. A.
Biology

subject: Biology Biology

abstract: Some properties of the small linear molecules N₂, CO and C₂H₂, physically absorbed on a graphite surface, are investigated in experiments and computer simulations. Acetylene, physically absorbed on graphite, is known to have two solid phases, but no clear indications of liquid-gas and liquid-solid coexistence has been observed. Vapor pressure isotherms of C₂H₂ on exfoliated graphite are measured revealing the two solid phases and also both coexistence phases. At high temperature Henry's law constants of C₂H₂ and CO on graphite are measure and used to refine the parameters of potential models. For CO, it is found that a 10-4 model is easily fit to the data, but in the case of C₂H₂ no realistic parameters in a 10-4 model resulted in an acceptable fit. A qualitative explanation, invoking an image force, is offered but quantitative attempts fail as the large quadrupole moment of C₂H₂ causes the model for the image interaction to break down. Monte Carlo calculations of the two solid structures are presented which disagree with the proposals in the literature but are in agreement with diffraction data. X-ray and LEED studies of monolayer densities of CO and N₂ absorbed on graphite have revealed the low temperature structure to be a 1x√3 herringbone and to change to an incommensurate herringbone structures at slightly greater densities. Orientational order-disorder transitions occur at both densities but the character of the transition is different in N₂ than in CO. Classical Monte Carlo calculations of the integral heat absorption vs. coverage are presented for several potential models are compared to experimental measurements. The best of these models are used in Monte Carlo simulations of the orientational order-disorder transition in N₂ and CO. The result for N₂ compare well with experiment but in the case of CO the agreement is not a good as the potential model seems to correspond to a molecule which is too small

abstract: Doctor of Philosophy (PhD)


title: The Design and Implementation of a Library Data Base

contributor:
Redish, K. A.
Computer Science

subject:
Computer Sciences
Computer Sciences

abstract:
This project will implement an interactive system that allows users to interrogate the hierarchic program Library Index.

Major components include transformation of the existing Index into the necessary Data Base and the Design and Implementation of the interactive query-answer system.

The system will include the SCHEMA, SUB-SCHEMAS and the required application Programs.

abstract: Master of Science (MS)


title: Possible repair of radiation-induced nondisjunction in mouse oocytes

contributor: Medical Sciences (Growth and Development)

subject:
Medical Sciences
Medical Sciences

abstract: There are some data human epidemiological studies which suggest that radiation has a small but significant effect in causing aneuploid gametes. Alberman et al. (1972) suggested that much of this radiation occurred more than ten years before the conception of the abnormal child. Mice have been used to study experimentally radiation effects on chromosome segregation. Radiation induces nondisjunction in several strains, including (C₃HxICR/Swiss)F₁ females. The present study was designed to investigate the possibility of repair of the mechanisms which results in nondisjunction following irradiation. Female (C₃HxICR/Swiss)F₁ mice were randomized into 4 experimental groups at 6-8 weeks of age. Some were irradiated at 3 months with 20R gamma rays from a ¹³⁷Cs source. Young mice were sacrificed at 3 months of age, within 24-48 hours of irradiation. Others were irradiated then housed until 9 months old. At the time of sacrifice ovaries were removed and the oocytes obtained were cultured to the metaphase II stage. Chromosomes were then analyzed. Oocytes from 974 mice were studied. The frequency of spontaneous nondisjunction in oocytes from young mice was quite low (0.2%) and this increased significantly after irradiation to 1.6% (p=0.001). The spontaneous frequency of nondisjunction in oocytes increased with age from 0.2% to 1.2%. In contrast the nondisjunction frequency in oocytes from irradiated-aged animals was 0.0%. In other words, following irradiation at a young age, no aneuploid oocytes were recovered. This is significant different from the frequency in control aged animals, p=0.002. The mechanism by which radiation causes nondisjunction is not known. Possibilities include damage to the centromere region or radiaton could act by causing premature or accelerated terminalization of chiasma. The disappearance of aneuploid oocytes in irradiated-aged animals in this study suggests that in addition to causing nondisjunction immediately there is a delayed effect somewhere between 48 hours and 6 months which results in an elimination of abnormal cells. This experimental finding in mice is quite different from epidemiological information from humans. It provides an avenue for further research into agents causing chromosome abnormalities and the factors involved in germ cell selection and survival.

abstract: Doctor of Philosophy (PhD)


title: Finite Element Modelling of Stiffened Steel Box Girders with Imperfections

subject:
Civil Engineering
Mechanical Engineering
Civil Engineering

abstract: An elasto-plastic large displacement finite element model has been developed to analyse stiffened plated box girders. It is capable of predicting inelastic buckling behaviour and ultimate strength under stated loads. Both geometric imperfections and residual stresses are included to account for inherent flaws due to fabrication processes. The model is formulated through a three-dimensional assemblage of rectangular plate elements for the webs, flanges and diaphragms, and eccentric beam elements for stiffeners. Plate and beam elements employed in the model incorporate both bending and in-plane actions. The non-conforming rectangular plate elements used to utilize special provisions for displacement continuity along junctions between components of the box. To reduce computational time and half band width requirements, diaphragms are treated as substances and then coupled with the rest of the box. For material nonlinearity, yielding is described by the Bon Mises criterion and the associated Prandtl-Reuse equations of plasticity. Subsequent yielding is governed by the isotropic hardening rule. Finite element formulation for large deflection is based upon a total Lagrangian description. In the solution to problems, the analysis involves the Newton-Raphson iterative method for the nonlinear analysis using an incremental load procedure. The formulation is first verified using a variety of beams, plates and three-dimensional plate assemblage problems. The present predictions compare favourably with other theoretical and experimental results already published in the technical literature. The proposed model is then applied to a symmetrical overhanging stiffened steel box girder recently tested to stimulate a typical pier girder of a continuous bridge. A series of numerical simulations were made both for the perfect box and its imperfect equivalent, in which imperfections are confined to the compression flange. Attention was focused on initial plate panel imperfections, longitudinal stiffener out-of-straightness, and idealized residual stresses. Analytical results to be presented include ultimate load, failure mode, state of longitudinal stress distribution, and spread of plasticity. A comparison with results from the physical model shows excellent agreement. The imperfections postulated for the theoretical model are shown to somewhat reduce the predicted strength of box girders. Any analysis neglecting this effect overestimates the buckling strength.

abstract: Doctor of Philosophy (PhD)


title: Bounding Methods for Facilities Location Problems

contributor:
Love, R. F.
Management Science/Systems

subject: Management Information Systems

subject: Management Information Systems

abstract: Several methods have been proposed and tested for calculating lower bounds on the objective function of facilities problems. These methods contribute to the efficiency of iterative solution methods by allowing the user to terminate the computation process when the objective function comes within a predetermined fraction of the optimal solution. Two of the existing bounding methods have been presented only for single facility location models with Euclidean (straight-line) distances. One of these methods uses the dual of the single facility location model to compute a lower bound. This thesis introduces a method for generating a feasible dual solution from any primal solution by means of a projection matrix. The projection matrix method is applied to single and multi-facility models. The second bounding method, which involves the solution of a rectilinear distance model to obtain a lower bound, is extended in this thesis to include a generalized, distance function and the multi-facility situation. Computation results for the two new bounding methods are compared with several existing bounding methods. These results should aid practitioners in selecting an appropriate bounding method for an iterative solution method to a facilities location problem.

abstract: Doctor of Philosophy (PhD)


title: Decay of a High Arctic Lake Ice Cover

contributor:
Woo, M.K.
Biology

subject: Biology Biology

abstract:
This is a study of the decay processes if an ice cover on a small Arctic lake. The study was carried out neat Resolute. N.W.T., Canada, for two melt seasons commencing in late May prior to melt and continuing until the lake was ice-free in late July. During this period, ice thickness, other ice properties and melt from the upper and lower ice surfaces were measured rapidly. In addition, environmental conditions which affect the melt rate, such as air and water temperatures and net radiation were obtained to permit a computation of the energy balance for the ice.

A one-dimensional energy balance model used to calculate the ice melt, at a site performs well in predicting the ablation from the upper ice surfaces, melt from the lower ice surface and the internal melt and ice density. For the two study years, 49 percent of the melt (in water equivalent units) occurred in the ice interior due to absorbed radiation while ice melt at the upper ice surface (in water equivalent) amounted to 40 percent. Melt at the lower ice surface was only 11 percent of the total ice melt. Seventy five percent of the change in ice thickness occurred at the upper ice surface where much of the internal ice melt was concentrated, producing low surface ice densities.

The formation of a moat along the edge of the ice cover and its subsequent growth was investigated. The results were incorporated in a two-dimensional model of ice decay along a transect normal to the shore. A series of transects allowed a simulation of the behaviour of the entire ice cover. The modelled results agree closely with the observed ice decay events from the beginning of melt until the fragmentation of the ice cover. Although the ice decay period was emphasized, the two-dimensional model can be expanded to include the season of ice growth.

abstract: Doctor of Philosophy (PhD)


title: A Kinetic Study of Hot Metal Desulphurization by Calcium Carbide Powder Injection

contributor:
Irons, G.A.
Lu, W. K.
Engineering

subject: Engineering Engineering

abstract:
Currently, sulphur is the most problematic impurity which affects the physical and mechanical properties of steel. Therefore all the integrated steel producers desulphurize iron before steelmaking. Calcium carbide is one of the reagents used to desulphurize hot metal from the blast furnace, yet the kinetic reaction phenomena are not clear. The present work was initiated to study the kinetics of hot metal desuIphurization by calcium carbide powder Injection at the 3 Tonne scale.

The most Important variables which affect the rate and efficiency of calcium carbide desulphurization are the type of top slag, the Injection conditions and the oxygen activity In the hot metal.

The present results quantitatively demonstrate these effects. The experimental results indicate that control of the Initial slag condition can effectively improve the, rate and efficiency of calcium carbide desulphurization. It was found that lower solid loading Is kinetically favorable for both slag/metaI and plume desuIphurization. Oxygen activity measurements show that oxygen plays a crucial role in desuIphurization, particularly to achieve extra-low suIphur levels.

A steady-state, one-dimensional, three-phase model was developed to model the plume desulphurization kinetics. The model permits a quantitative analysis of the present experimental results. The computed results from the model are found to be consistent with the experimental data.

abstract: Doctor of Philosophy (PhD)


title: Application of Eccentricity Concept to Multistory Buildings

subject:
Civil Engineering
Other Mechanical Engineering
Civil Engineering

abstract: This thesis presents a study in extending the eccentricity concept to multistory buildings to evaluate their torsional behavior under static and dynamic lateral loads. The eccentricity concept enables the separation of horizontal loadings into lateral and torsional components thereby enhancing the understanding of the structural behaviour of multistory buildings. To achieve this, formal definition for the center of rigidity is established for eccentric and irregular multistory buildings in general. The centers of rigidity are shown to be load centers at the floors and they should be reference points from which eccentricities are measured. A procedure is given to locate the rigidity centers with the aid of a plane frame program. The centers of twist are then defined. They are convenient points of reference for the generalized floor displacements and will lead to uncoupled equations of lateral and torsional equilibrium. The centers of rigidity and centers of twist are in general load dependent and not the same set of points for multistory buildings. Only for buildings with proportional framing that they become the same set of points. A method for lateral load analysis of symmetric and eccentric setback structures is presented next. The eccentricity concept and the displacement compatible load concept are employed by the proposed method. This is a non-trivial application of the eccentricity concept in analysis of irregular multistory buildings. Finally, an analytical investigation into the static and dynamic behaviour of uniform eccentric wall-frame buildings is carried out to examine the complexities of wall-frame interaction under eccentric loadings. A class of uniform eccentric wall-frame buildings had been identified which will have centers of rigidity along a vertical line, thereby satisfied the seismic provision requirement of NBCC 1985. The adequacy of the code procedures is evaluated for this class of structures. It is shown that for other classes of eccentric wall-frame multistory buildings, it is difficult to apply the concept of eccentricity and code procedures to obtain reasonable estimates of the torsional effect. For eccentric wall-frame structures in general, therefore, dynamic analysis remains to be the most reliable method to distribute the torsional effect at the present time.

abstract: Doctor of Philosophy (PhD)


title: Runoff Hydrology of a Low Arctic Drainage Basin

subject: Biology Biology

abstract:
This is a study of the hydrology of a low Arctic drainage basin in the continuous permafrost region. The basin has a varied surface cover of upland tundra, wetlands and lakes. A water balance computed at the basin in scale determines the relative importance of various hydrological components including snowmelt, rainfall, inflow, evaporation and outflow. Studies conducted at the sites representative of uplands, wetlands and lakes quantify the magnitude and temporal variability of runoff. By combining the process and water balance studies results, an explanatory framework is developed for the spring and summer hydrology.

Snowmelt is the largest input of water to the basin and runoff is one thirds greater than evaporation as a loss. Peak discharges occurs during snowmelt when the meltwater exceeds the storage capacity available in the basin. Snowmelt contribution is greater from the wetlands areas, but, because of a larger area extent, upland meltwater contribution is also significant. The wetlands areas provide a route through which lake and channel overbank flow and meltwater are conveyed to the basin output. Surface flow is the primary runoff process during snowmelt in both wetland an upland areas.

In summer, evaporation is the major process through which water is lost from the basin. Upland areas become dry, but wetlands have enough stored water to sustain evaporation at potential rates. Runoff response to a rainstorm is negligible when the basin is dry, but is significant of previous storms have saturated the upland and the wetland areas. Storm runoff is produced first from hummocky areas at the base of hillslopes, then from uplands and finally from the wetlands. When all the parts of the basin contribute storm runoff the basin response will be both large and rapid. Stormflow recession is long for all storms.

The upland-wetland-lake hydrological system examined in this study is typical of the North American low Arctic environment. Through an understanding of both the hydrological processes with each subsystem and the linkages between subsystems an explanation of the runoff regime of a low Arctic drainage basin is obtained.

abstract: Doctor of Philosophy (PhD)