title: Characterization of Virus Specific Polypeptides During Pichinde Virus Infection in Cell Culture

contributor:
Rawls, William E.
Biology

subject: Biology Biology

abstract:
Several aspects of the replication of Pichinde virus, a member of the arenavirus group, were studied in in vitro cell culture. The major emphasis in the study was the identification and characterization of Pichinde virus encoded polypeptides expressed in infected BHK-21 cells. Polypeptides were identified by immunoprecipitation of lysates of infected cells with hamster anti-Pichinde virus immune serum. Several polypeptides exhibited a temporal and multiplicity of infection dependent appearance. Polypeptides with approximate molecular weights of 200,000, 79,000, 64,000, 48,000, 38,000 and 28,000 were identified by SDS-polyacrylamide gel electrophoresis after a 1 hr pulse label of infected cells with L-[³⁵S] methionine. The same polypeptides and five more of 52,000, 36,000, 17,000, 16,500 and 14,000 daltons were identified in pulse-chase experiments. The 79,000, 52,000 and 36,000 dalton polypeptides incorporated ³H-glucosamine. The larger glycoprotein was identified as a precursor to the smaller structural glycoproteins (GPl and GP2) and has been designated GPC. In the presence of tunicamycin, an inhibitor of glycosylation, GPC was synthesized as a 42,000 dalton precursor (pGPC). The nucleoprotein (NP, 64,000 daltons) was the predominant immunoprecipitable polypeptide.

Polypeptide interrelationships were determined by two dimensional L-[³⁵S] methionine tryptic peptide mapping. The 200,000 dalton polypeptide (L), GPC and NP were distinct primary products of translation. Polypeptides of 48,000, 38,000, 28,000, 17,000, 16,500, and 14,000 daltons were all related to the nucleoprotein. NP17, l6.5 and 14 were derived proteolytically but the larger molecules (NP48, NP38 and NP28) may be distinct premature termination products of translation.

L, NP, GP1, GP2, NP48 and NP38 were found in immunoprecipitates of infected cell extracts and in purified virus preparations. GPC, NP28, NP17, NP16.5 and NP14 were evident only in immunoprecipitates of infected cell extracts. The function, if any, of the NP derivatives is not known. L was postulated to be the viral encoded RNA-dependent RNA polymerase.

The affect of amino acid analogues, actinomycin D, and α amanitin and amphotercerin B, on viral protein synthesis and processing was examined. α-ananitin and amphotercerin B did not affect the SDS-PAGE polypeptide profile. Actinomycin D did not alter the profile of immunoprecipitable polypeptides after a 1 hr pulse-label, however, after a 6 hr chase period NP17, NP16.5 and NP14 were not apparent.

The coding sequences for the primary products of translation, (L, NP, GPC) were assigned to either L or S viral RNAs. To do so, prototype Pichinde and Muchinque viruses and a reassortant virus (RE-2) were employed. The reassortant virus contains the L RNA of Pichinde virus and the S RNA of Munchique virus. NP and GPC were shown to be encoded by S RNA. The two-dimensional L-[³⁵S] methionine tryptic peptide maps of these molecules in Munchique virus and RE-2 virus were identical. L polypeptide tryptic peptide profiles were identical in Pichinde and RE-2 viruses which suggested that L is enclosed by L RNA.

A series of very preliminary experiments were performed to characterize properties of Pichinde virus replication, primarily in BHK-21 cells, but also in MDCK and Vero cells grown in vitro. Infection of all three cell lines resulted in a peak of infectious virus released into the medium 2 to 3 days later. This was followed by a rapid decline in viral release to 10% of peak levels by days 8 to 10. Similar curves were observed for synthesis of viral macro-molecules in the cell, however, immunofluorescence during this period remained high. We attempted to correlate the immunofluorescence observations with proteolytic products of NP using monoclonal anti-bodies directed against these molecules.

A model for regulation of Pichinde virus replication in infected cells is presented. The model proposes that the nucleoprotein or its proteolytic products are integral factors in the decline of viral synthesis.

abstract: Doctor of Philosophy (PhD)


title: Cavern Development in the Dimensions of Length and Breadth

contributor:
Ford, Derek C.
Geography

subject: Geography Geography

abstract:
Three conceptual models are proposed for the integration of the large systems of conduits responsible for groundwater flow in soluble rocks. These models are supported by laboratory experiments with scaled solution models, flow-field analogues, and evidence from existing caves.

The three models reflect different boundary conditions imposed by geologic structure and stratigraphy. They have three characteristics in common. First, the smaller elements of the larger systems propagate separately from points of groundwater input toward points of discharge as distributary networks. Second, the integration of the smaller networks proceeds headward from the resurgence, in a stepwise fashion. Third, the result of the integration process in each case is a tributary system with many inputs discharging through a single discharge point.

The potential for growth of each of the smaller networks, within a common pressure field, is related to its distance from the discharge boundary and the distribution of other inputs. The first input to establish a low-resistance link to the discharge boundary will effect a localized depression within the potential field, thus attracting the flow and redirecting the growth of nearby networks until they eventually link with it. As additional orders of links develop, the system takes on a tributary pattern.

The first model applies to steeply dipping rocks. Inputs occur where bedding planes are truncated by erosion, and discharge takes place to the strike. Conduits in this case evolve as a roughly rectangular grid of strike and dip oriented elements. Dip elements are the initial form, with subsequent integration along the strike. The type example is the Holloch in Switzerland.

The second model applies to flat-lying rocks. Inputs occur over a broad area, and discharge takes place along a linear boundary. Conduits in this case evolve in a trellised array with elements normal to the discharge boundary predating those parallel to it. These latter conduits integrate the flow. The type example is the Mammoth Cave Region, Kentucky.

The third model applies to simple systems which occur beneath an impermeable cap rock. Inputs occur where erosion has breached the capping beds. The type example is Cave Creek, Kentucky.

abstract: Doctor of Philosophy (PhD)


title: Covenant and Kingship in Ancient Israel. A Reading of 1 Samuel 1-12

contributor:
Cooper, A.M.
Religious Studies

subject: Religion Religion

abstract:
Chapters 8-12 of 1 Samuel have long been studied as a source of information about the development of a monarchy in ancient Israel. In modern scholarship the narrative in these chapters has usually been approached from the methodological perspective of historical criticism, in which an attempt is made to reconstruct both the historical events described in the narrative and the historical process of composition that resulted in the narrative. The result of 200 years of such study is that 1 Sam 8-12 is no longer read as a literary unit; individual units of the text are ascribed to various authors writing in various times and places, with various opinions about the concept of an Israelite monarchy.

The hypothesis explored in this dissertation is that it may yet be possible, perhaps even necessary, to read 1 Sam 8-12 as a literary whole in order to understand it properly. Moreover, initial surveying of the literary and rhetorical features of the narrative suggest that it is necessary to read 1 Sam 8-12 in the light of 1 Sam 1-7. Taken together, the various scenes in 1 Sam 1-12 constitute an episode in the continuing story of the theological-political experiment that was ancient Israel's national existence. When these twelve chapters are read together, they are found to contain a coherent exploration of a single problem experienced by ancient Israel as it attempted to live in a covenantal relationship with its national God, Yahweh.

The methodological approach used in this dissertation may be characterized as a close reading of the text that attempts to discover the literary techniques of Hebrew narrative, to describe these techniques, and to use the resulting understanding of Hebrew narratology to understand and interpret the ideas presented by the narrative. The basic premise of this approach is that in order to understand an ancient text from a foreign culture, the modern reader must allow his reading to be guided and educated by the literary conventions of the text. The most basic requirement for this type of reading is that the reader describe the narrative, rather than evaluating it, either as literature or history.

abstract: Doctor of Philosophy (PhD)


title: The Synthesis and Physical Properties of Infinite Mercury Chain Conducting Materials

contributor:
Gillespie, R.J.
Chemistry

subject: Chemistry Chemistry

abstract:
Novel synthetic pathways for the production of infinite mercury chain materials (Hg₃₋δMF₆) were investigated and some of the physical properties of the materials were studied. The solution chemistry of the homopolyatomic cation system (Hg₂²⁺, Hg₃²⁺, Hg₄²⁺) from which either Hg₃₋δAsF₆ or Hg₃₋δSbF₆ are formed was probed using ¹⁹⁹Hg NMR (Nuclear Magnetic Resonance).

Both O₂⁺ and NO+ salts of the ASF¯₆ or SbF¯₆ ions oxidized metallic mercury to produce the known materials Hg₃₋δMF₆.

Differential Thermal Analysis (DTA) was used to study both low and high temperature phase transitions in the conducting materials. A phase transition at approximately 235 K has been associated with the reversible anisotropic extrusion of mercury from the crystals.

The thermal and hydrolytic decomposition pathways for Hg₃₋δAsF₆ were characterized and the absolute reflectance was also measured.

abstract: Doctor of Philosophy (PhD)


title: Disputes Among Experts: A Sociological Case Study of the Debate Over Biology in the Mackenzie Valley Pipeline Inquiry

contributor:
Marshall, V. W.
Sociology

subject: Sociology Sociology

abstract: This work is a sociological case study of the disputes among expert biologists in the Mackenzie Valley Pipeline Inquiry. I argue that the disputes among experts are structured by the interest groups who sponsored expert testimony. Interest groups varied in their resources, organizational structure, interaction experiences, and basic defensive or critical argumentative stance. This variability is shown to be related to the cohesiveness of expert arguments across seven major debating points. Open-ended interviews form the basis of most of the analysis. Since the populations are small, extensive quotations from the responses of participants are used at many points. The analysis is qualitative at many crucial points. The interviews are supplemented by an analysis of hearing transcripts, supporting material presented at the Inquiry, and published materials relating to the Inquiry. The argument is constructed using an image of all action, including scientific reasoning, as interpretive action. Although a social product, action is considered to be a complex interpretive process. The importance of this image of action is developed in the assessment of the influence of various scientific and non-scientific issues to the opinions of scientists as experts. I treat statements by participants as part of arguments which, I suggest, are unclear as to their motivational implications. Within this framework, I consider the importance of interest groups for the structuring of expert arguments. I argue that the major industrial proponent was able to present an extremely cohesive set of expert arguments because of a variety of factors including their greater resources, their longer time to prepare a case, and their experience of having to defend a position. In contrast, critics, with their relatively meager resources, shortage of time, and position of critic, presented a far less cohesive set of expert arguments. This lack of a parallel structure in arguments runs counter to the dominant image, in the literature, of a more clearly polarized debate in conflicts among experts.

abstract: Doctor of Philosophy (PhD)


title: Ground State Number Fluctuations of Trapped Particles

contributor:
Bhaduri, Rajat K.
Physics

subject: Physics Physics

abstract: This thesis encompasses a number of problems related to the number fluctuations from the ground state of ideal particles in different statistical ensembles. In the microcanonical ensemble most of these problems may be solved using number theory. Given an energy E, the well-known problem of finding the number of ways of distributing N bosons over the excited levels of a one-dimensional harmonic spectrum, for instance, is equivalent to the number of restricted partitions of E. As a result, the number fluctuation from the ground state in the microcanonical ensemble for this system may be found analytically. When the particles are fermions instead of bosons, however, it is difficult to calculate the exact ground state number fluctuation because the fermionic ground state consists of many levels. By breaking up the energy spectrum into particle and hole sectors, and mapping the problem onto the classic number partitioning theory, we formulate a method of calculating the particle number fluctuation from the ground state in the microcanonical ensemble for fermions. The same quantity is calculated for particles interacting via an inverse-square pairwise interaction in one dimension. In the canonical ensemble, an analytical formula for the ground state number fluctuation is obtained by using the mapping of this system onto a system of noninteracting particles obeying the Haldane-Wu exclusion statistics. In the microcanonical ensemble, however, the result can be obtained only for a limited set of values of the interacting strength parameter. Usually, for a discrete set of a mean-field single-article quantum spectrum and in the micro canonical ensemble, there are many combinations of exciting particles from the ground state. The spectrum given by the logarithms of the prime number sequence, however, is a counterexample to this rule. Here, as a consequence of the fundamental theorem of arithmetic, there is a one-to-one correspondence between the microstate and the macrostate, resulting in the vanishing of number fluctuation for all excitations. The use of the canonical or grand canonical ensembles, on the other hand, gives a substantial number fluctuation from the ground state. For a related spectrum, that given by the logarithms of an integer n, the microcanonical number fluctuation is non-zero but the application of the other ensembles is still not valid. These two spectra are examples of systems where canonical and grand canonical ensembles averagings yield answers different from the microcanonical result. Some models in physics may be used to obtain formulae known in the theory of number partition. For the same problem of N ideal bosons in a one-dimensional harmonic oscillator potential mentioned earlier, it is well known that the asymptotic (N --> ∞) density of states is identical to the Hardy-Ramanujan formula for the number of partitions of an integer n. The same statistical mechanics technique for the density of states of bosons in a power-law spectrum yields the partitioning formula for the number of partitions of n into a sum of 8th powers of a set of integers. By considering only the particle sector of the fermionic spectrum, a formula for the number of distinct partitions of n is obtained. For the s = 1 case and for finite N, the Erdos-Lehner formula for the restricted partitions, and a new formula for the distinct and restricted partitions are derived. As a diversion, we discuss the microcanonical entropy which may be uniquely defined in terms of the macrostate, or equivalently the many-body degeneracy of the state, at a given energy. The many-body degeneracy factor, however, is exceedingly difficult to calculate in general. It is thus desirable to find a different way to calculate the micro canonical entropy. It has been recently suggested that the microcanonical entropy may be accurately reproduced by including a logarithmic correction to the canonical entropy. This claim is readily tested using some of the models mentioned above, where the many-body degeneracy may be determined exactly. In addition, we also consider a system of N distinguishable particles in a d-dimensional harmonic energy spectrum. In this case the many-body degeneracy factor can be obtained analytically in a closed form.

abstract: Doctor of Philosophy (PhD)


title: GERMLINE MUTATIONS AT EXPANDED SIMPLE TANDEM REPEAT DNA LOCI IN SENTINEL MICE

contributor:
Quinn, James S.
Biology

subject: Biology Biology

abstract: Exposure to environmental contaminants that can cause genetic damage may pose a risk of induced heritable mutations in wildlife and humans. Herring guns (Larus argentatus) nesting near integrated steel mills on the Great Lakes were shown to have elevated heritable mutation rates, but the importance of airborne and aquatic routes of contaminant exposure could not be determined. I showed that sentinel mice exposed to urban-industrial air pollution in situ near two integrated steel mills and a major highway had germ line mutation rates at expanded-simple-tandem-repeat (ESTR) DNA loci that were 1.5- to 2.0-times as high as mice exposed at a cleaner rural site. In addition, high-efficiency articulate-air filtration (HEPA) reduced mutation induction at the urban-industrial site, implicating a causal role for airborne particulate matter. These experiments identify an important role for air pollution exposure in the induction of heritable DNA mutations. I developed and tested a novel diet medium for feeding high percentages of fish to mice for toxicology experiments. This diet was then used in a study of germline mutations in mice fed fish collected from a polluted industrial site, compared to those fed fish from Atlantic Canada, or control chow. There was a non-significant trend for mice that consumed fish from the polluted site to have higher germhne ESTR mutation rates than those in the other groups. For my experiments I used out-bred Swiss-Webster mice that had not been characterized previously in studies of germline ESTR mutations. I exposed male mice to ionizing radiation to determine whether germline mutation rates increased in a dose-dependent manner following exposure to a known mutagen. Mutation rates did not increase linearly with radiation dose, showing evidence of saturation, but the estimate of doubling-dose was similar to that previously published for some inbred mouse lines.

abstract: Doctor of Philosophy (PhD)


title: Space, State and Crisis: Towards a Theory of the Public City in North America

contributor:
Dear, M. J.
Geography

subject: Geography Geography

abstract:
This thesis examines the development of the public city (the increasing concentration of service-dependent populations and their helping agencies in the inner city) in North America, during the last decade. A historical materialist explanation of public city development is provided. The welfare state and the suburban form of the city are derived as structural solutions to previous impediments of the accumulation process. Inherent contradictions in these solutions are examined and the way in which they have intensified have been outlined. The public city is then viewed as an emerging structural solution to the inherent contradictions of the welfare state and and the suburban form of the city. The central city is the focus of public city development because of the characteristic features which it attained as the developing corollary of the suburban city during the suburbanization process. The gradual intensification of contradictions in the suburban form of the city made it an increasingly unsuitable and hostile environment for the service-dependent, forcing them to increasingly concentrate in the inner city. Simultaneously, the specific processes of restructuring the welfare state during the period of crisis have led to a marked intensification of public city development.

Historical analysis of the process of restructuring the Canadian Welfare State in Ontario highlighted the links between the economic crisis, the process of restructuring and the development of the public city. Service-dependent populations examined in this thesis include ex-psychiatric patients, mentally retarded, physically disabled, elderly, probationers and parolees. The results of the analysis of each of these populations indicated that restructuring of the welfare state had increasingly concentrated these populations in the inner city, leading to a rapid intensification of public city development.

abstract: Master of Arts (MA)


title: Evapotranspiration in Greenhouses

contributor:
Rouse, W.R.
Geography

subject: Geography Geography

abstract: A physically based evapotranspiration model has been developed and tested in an experimental greenhouse. Good agreement was found between hourly model estimates and mass balance measurements of the latent heat flux. The model recognizes the advective nature of the greenhouse microclimate and thus represents an improvement over empirical model estimates of evaporation based on the measurement of radiation alone. Although radiant heating is the dominant mechanism responsible for evapotranspiration it does not represent a constant proportion on an hourly or daily basis. As a result, the Bowen ratio varies over time. Most of the variation was attributable to advection, and to a lesser extent, the sensible and latent heat fluxes at the glazing. During the daytime, the evapotranspiration process utilized in excess of 70% of the net available energy at the surface. However, model estimates and empirical evidence indicate this proportion can equal or exceed 100%. Variations in the latent heat flux are shown to depend on greenhouse design and the ambient microclimate. Simulation of the greenhouse humidity environment using 10 year hourly climatic means for Woodbridge, Ontario demonstrates the effect of modifying ventilation rates, glazing transmission and intake humidity on potential evapotranspiration. A relation is presented which permits the real-time adjustment of ventilation resistance from meteorological measurements of solar radiation and dry and wet-bulb air temperature. The maintenance of potential evapotranspiration for optimal crop productivity is shown to be incompatible with the collection and storage of sensible heat of the exhaust air as a means of defraying greenhouse heating costs.

abstract: Doctor of Philosophy (PhD)


title: Perturbations of Short RNA Helices

contributor:
Neilson, Thomas
Biochemistry

subject:
Medical Biochemistry
Medical Biochemistry

abstract:
A variety of short oligoribonucleotide sequences were synthesized using the phosphotriester chemical synthesis developed in Neilson's laboratory. These sequences were designed to incorporate a variety of features that would aid in the study of perturbations of helix structure and stability. Variable temperature proton nuclear magnetic resonance (NMR) spectroscopy was used in this study and provides a powerful technique for the study of nucleic acid conformations and for the investigation of the effects of the mispairing and single stranded regions caused by the helix imperfections introduced.

The assignment procedure for NMR spectra was improved through the study of a series of related sequences. This study determined the effects that the addition of a nucleotide to the terminus of a sequence or the insertion of a nucleotide into the middle of a sequence would have on the chemical shifts from the rest of the sequence.

A series of self-complementary pentaribonucleotides, with a central non-base paired opposition (AGXCU, where X ≡ A, G, C or U), was studied to determine the effects of small loops on duplex stability. In contrast to earlier results, these pentamers formed stable duplexes when X ≡ A or C, although the duplex Tm's were significantly, reduced. These sequences also provided the opportunity to study the sequence effects of adjacent internal G.C base pairs on duplex stability when the middle base pair was A·U, G·C or G.U. Comparison with earlier results using corresponding A·U base pair neighbours, demonstrated the enhanced stabilization of G·C base pairs.

The effects of terminal non-base paired (dangling) adenosines were more closely investigated and found to contribute an average of 11°c to the thermal stability of the duplex formed. This study also demonstrated that 5'-dangling adenosines contribute less to overall stability than do 3'-dangling adenosines. However, this effect did display some sequence dependence.

The triribonucleotide GpCpA was the first trimer shown to form a stable RNA duplex (Tm = 33°C). The duplex consisted of two G·C base pairs and two 3'-dangling adenosines and had a stability equal to that of the tetramer duplex UpGpCpA with four Watson-Crick base pairs.

The influence of base stacking on duplex formation was studied and it was discovered that the direction of base stacking had a definite influence on helix stability. Stacking in the 5'→3' direction was more favourable to duplex formation than stacking in the 3'→5' direction.

Lastly, the significance of invariant adenosines at position 14 and 21, in the D-stem of tRNA, was investigated through a model study that suggested the adenosines contributed to D-stem stability.

Most of the results presented in this thesis have been published or accepted for publication in:

1. Jeremy R. Everett, Donald W. Hughes, Russell A. Bell, Dirk Alkema, Thomas Neilson and Paul J. Romaniuk. "Nearest-Neighbour and Next-Nearest-Neighbour Effects in the Proton NMR Spectra of the Oligoribonucleotides ApGpX and CpApX." (1980) Biopolymers 19, 557.

2. Thomas Neilson, Paul J. Romaniuk, Dirk Alkema, Donald W. Hughes, Jeremy R. Everett and Russell A. Bell. "The Effects of Base Sequence on the Stability of Short Ribonucleic Acid Duplexes." (1980) Nucleic Acids Res. Sym. Series No. 7, 293.

3. Dirk Alkema, R.A. Bell, P.A. Hader and T. Neilson. "Triplet GpCpA Forms a Stable RNA Duplex." (1981) J. Am. Chem. Soc. 103, 2866.

4. Russell A. Bell, Jeremy R. Everett, Donald W. Hughes, Dirk Alkema, Paul Hader, Thomas Neilson and Paul J. Romaniuk. "Nearest-Neighbour and Next-Nearest-Neighbour Effects in the Proton NMR Spectra of the Oligoribonucleotides ApXpG, CpXpG, CpApXpUpG, ApGpXpC and ApGpXpCpU." (1981) Biopolymers 20, 1383.

5. Dirk Alkema, Russell A. Bell, Paul A. Hader and Thomas Neilson. "Short RNA duplex Stability: Contribution from non-base paired residues to the direction of stacking." (1981) in "Biomolecular Stereodynamics" R.H. Sarma, ed., Adenine Press, Elmsford, NY., p. 417.

6. Dirk Alkema, Russell A. Bell, Paul A. Hader and Thomas Neilson. "Invariant Adenosine Residues Stabilize tRNA D-steins." (1982) Accepted for publication in FEBS Letters.

7. Dirk Alkema, Paul A. Hader, Russell A. Bell and Thomas Neilson. "Effects of Flanking G·U· Base Pairs on Internal Watson-Crick, G·U and Non-Bonded Base Pairs Within a Short RNA Duplex." (1982) Accepted for publication in-Biochemistry.

Two additional publications will appear shortly:

1. Paul A. Hader, Thomas Neilson, Dirk Alkema, Eric C. Kofoid and M.C. Ganoza. "Sequencing of Short RNA Oligomers by Proton Nuclear Magnetic Resonance." (1982) Accepted for publication in FEBS Letters.

2. Paul A. Hader, Dirk Alkema, Russell A. Bell and Thomas Neilson. "Parameters for Proton Chemical Shift Prediction in Oligoribonucleotides." (1982) J. Chem. Comm. (in press).

abstract: Doctor of Philosophy (PhD)


title: Role of ErbB3 During Mammary Tumorigenesis

contributor:
Muller, William J.
Medical Sciences

subject:
Medical Sciences
Medical Sciences

abstract: Overexpression of the Neu/ErbB-2 receptor tyrosine kinase is implicated in the genesis of human breast cancer. Previous studies have observed elevated levels of endogenous ErbB3 protein in Neu-induced tumors. Although it has been suggested that the aberrant co-expression of Neu and ErbB3 may play a critical role in the induction of human breast tumors, the biological significance and the molecular mechanism of ErbB3 regulation during Neu-mediated tumorigenesis remains unclear. The results of this thesis demonstrate that the ability of ErbB3 to be constitutively phosphorylated and to regulate cell cycle progression through the activation of the PI-3K/mTOR pathway fully depends on the activity of Neu. Both PI-3K and mTOR in turn are involved in sustaining high levels of ErbB3 protein by increasing its stability. A mutant of ErbB3 unable to recruit and activate PI-3K (ErbB3-6F), blocks Neu-induced transformation, disrupts the mTOR/4EBP1 pathway and leads to apoptotic cell death. This strongly suggests that ErbB3 's role in these tumors is to provide cell survival signals by recruiting the p85 regulatory unit of PI-3K and coupling overexpressed Neu to the PI-3K/mTOR/4EBPl pathway. This thesis further demonstrates that the mTOR inhibitor rapamycin, delays the onset and inhibits the growth of Neu-induced mammary tumors in transgenic mice. The rapamycin-induced tumor inhibition correlates with downregulation of ErbB3, S6K, 4EBP1 and cyelin D1. I also show that the ErbB3-6F mutant exhibits antitumor activity in vivo by preventing tumor growth and facilitating tumor regression. Therefore, the antitumor activity of the rapamycin analogue, CCI-779 in human breast cancer may be mediated, in part, through the inactivation of ErbB3 thereby inhibiting the critical cell survival signals necessary for transformation. Taken together these results strongly suggest that Neu requires ErbB3 to drive mammary transformation and that the ErbB2/ErbB3 heterodimer may function as an oncogenic unit to recruit distinct yet complimentary signaling pathways that cooperate during mammary tumor progression. The results of this thesis provide a molecular basis for the selective targeting of the ErbB3/PI-3K/mTOR signaling pathway in the treatment of HER2-mediated human breast malignancies in which HER3 is overexpressed.

abstract: Doctor of Philosophy (PhD)


title: EXPLODING THE CULTURE OF CENSORSHIP, REPRESSION AND SILENCE: A CRITICAL ETHNOGRAPHIC STUDY OF RESPONSE TO SEXUAL BEHAVIOUR IN PERSONS WITH DEMENTIA LIVING IN LONG TERM CARE

contributor:
Skelly, Jennifer
Nursing

subject: Nursing Nursing

abstract: This dissertation was undertaken to scrutinize the positions of professional and family care givers in response to the sexual behaviours of persons living with dementia in three long term care facilities. In keeping with the tenets of critical ethnography and critical social theory, the intent was to identify response patterns that might need to be altered to reflect a person-centred dementia care philosophy (Kitwood, 1997, 1998). Semi-structured interviews, focus groups, and document review provided the material through which the rules, moral codes and actions in response to sexual behaviours were explicated. Ethnographic data transformation was undertaken through a process of description, analysis and interpretation. The most striking findings of this research were: a) the response patterns were conservative, protectionist and linear, ultimately leading to sexual expression being forbidden or admonished; b) There was a lack of organizational support so that study participants were operating within a vacuum. Consequently, participants relied upon their own value and belief systems when responding to sexual behaviour, leading to practice inconsistencies; and c) There was an overwhelming culture of silence in regard to the sexual behaviour of persons with dementia. The reluctance and discomfort, with which both staff and families approached sexual expression of residents with dementia, resulted in collusion that ensured sexual expression remained closeted and repressed. Study findings suggest that the culture of censorship and silence surrounding sexuality in persons with dementia remains similar to the centuries-old viewpoint requiring strict moral controls (Foucault, 1978). Evolving from the participants' accounts, an alternative approach involving collective dialogue is suggested. Implications of these findings extend to the need to expand organizational cultural perspectives through practice guideline development, educational initiatives and further research so that they come into alignment with the person-centred approaches that acknowledge the humanity, value and worth of those living with a dementia.

abstract: Doctor of Philosophy (PhD)


title: Integrated Coastal Engineering Modeling

contributor:
Tsanis, LK.
Civil Engineering

subject:
Civil Engineering
Civil Engineering

abstract: An Integrated Coastal Engineering model (ICEM) has been developed, which models the waves, the coastal circulation and the rates of bed level changes simultaneously. The wave model simulates the combined effect of refraction, diffraction, shoaling, reflection and breaking and the circulation model simulates the wave driven currents in the coastal zone. Finally, the morphological model simulates the sediment transport loads and the morphological changes after solving the combined wave current boundary layer. The waves, currents and sediment transport loads are recalculated for every so-called morphological time step. The ICEM is capable of modeling both the short and long term effects of coastal structures such as groins, detached breakwaters, seawalls, etc. The ICEM is calibrated and verified using field data in the Mediterranean coast of Egypt. The model is applied to similar areas in Crete, where the wave climate and bathymetric data are available. The best protection scheme is defined for each area. From the engineering point of view, this research provides an effective design tool for coastal protection projects. It also can provide an assessment on the effectiveness of the existing coastal protection projects.

abstract: Doctor of Philosophy (PhD)


title: THE INTERNATIONALIZATION OF PUBLIC POLICY AND MULTI-LEVEL GOVERNANCE: A COMPARISON OF FINANCIAL SERVICES SECTOR REFORM IN CANADA AND FRANCE

contributor:
Porter, Tony
Political Science

subject:
Political Science
Political Science

abstract: By constructing a theory of multi-level governance, the thesis advances a framework to study the internationalization of public policy and that of the international economy. The theory is used to analyse the autonomy of states and national governments in a globalizing environment. The thesis looks at the policy process in Canada and France in the financial services sector to determine the effects of multi-level governance on the way states take policy decisions. In Canada, the policy process for Bill C8, often incorrectly referred to as the merger legislation, was studied noting the changes that have occurred in the policymaking process since the last cycle of reform in the early 1990s. In France, the same type of analysis is provided for the newly adopted Financial Safety Bill, comparing the process for this legislation to that of the country's 1984 Bank Act. In both states, the discourse was adapted to include commitments and market opportunities provided through multi-level governance. The policy options studied took into account (though were not directed by) multi-level governance participation. The issue of competition was a dominant consideration in the policy process for both Canada and France. Lastly, the actors involved in the policy process have changed partly as a result of multi-level governance. Just as importantly, multi-level governance has strengthened the role of both public and non-governmental actors in policymaking. Contrary to those who see political globalization as restricting accessibility of policymaking processes, the strengthening of multi-level governance leads to greater openness of policy networks. Non-governmental actors, including private actors and consumer and civil society groups, are more prominent in these networks, but they do not exercise control, but rather engage further in broad-based policy consultation and negotiation. A striking feature of this thesis is the autonomy retained by states, even in Europe, in policymaking despite the internationalized nature of the fmance industry.

abstract: Doctor of Philosophy (PhD)


title: CARING FOR COGNITIVELY IMPAIRED ELDERLY IN NURSING HOMES IN ONTARIO: A CASE STUDY

contributor:
Black, Margaret
Nursing

subject: Nursing Nursing

abstract: The purpose of this case study was to describe registered nurses' experiences of working with the cognitively impaired elderly in three nursing homes in Southern Ontario. Interviews were conducted with registered nurses, the Directors of Care and the Educators at each of the nursing homes. A semi-structured questionnaire was used was used to elicit information regarding the nurses' choice to work in a nursing home, the nurses' experiences working with the cognitively impaired elderly, and factors that contribute to job satisfaction, dissatisfaction and commitment to remain working at the nursing home. Information was also collected from the nursing home database on turnover rates, absenteeism rates, RN salary scales and the number of educational sessions provided annually by the nursing homes. Thematic coding was used to identify themes within each case (registered nurse). A cross case analysis was conducted to determine relationships and explanations across the cases. A sub case analysis was also carried out, to identify patterns and themes present across the three nursing homes. Two major findings emerged from this study. The first finding was that registered nurses chose to work in a nursing home primarily as a 'job of convenience', i.e., no other positions in nursing were available in their desired geographical area; or they needed to find part-time work in their immediate geographical area in order to supplement their income. However, characteristics of the organizational environment played a major role in their remaining. Those characteristics were: a 'supportive environment' that included provision of opportunities for professional development, the presence of supportive colleagues, and flexible work scheduling practices. The second finding was the importance that the nurses placed on the caring relationship with the residents at the nursing home. All of the RNs described the enjoyment and the satisfaction that they obtained when caring for these residents. The primacy of 'caring' occurred even in the presence of some adverse characteristics of the work environment. The opportunity for 'caring' also influenced the nurses' choice to remain at the nursing home.

abstract: Doctor of Philosophy (PhD)


title: Identification of cell cycle regulatory proteins that interact with HCF-1

contributor:
Capone, John P.
Biochemistry

subject: Biochemistry Biochemistry

abstract: HCF-l, a transcriptional regulatory protein, was originally identified as an accessory factor for the induction of Herpes Simplex Virus immediate-early genes by the viral transactivator VP16. Recently, HCF-1 has emerged as a chromatin-binding transcriptional co-regulator that plays an essential role in cellular proliferation. In order to further characterize the function of HCF-1 and determine the mechanisms by which it contributes to cellular proliferation we have sought to identify novel HCF-1 interaction partners and elucidate their function. In this thesis, we describe the identification of key cell cycle regulatory proteins, Miz-1 and E2F-4, as novel HCF-1 interaction partners. Miz-1, a transcription factor that activates transcription of cell cycle inhibitory genes, is an integral part of the anti-mitogenic TGF-β pathway and contributes to cell cycle arrest following DNA damage and differentiation signals. HCF-1 associates with the Miz-1 transactivation domain and antagonizes Miz-1-dependent transcriptional activation of p15INK4b, a cyclin-dependent kinase inhibitor, suggesting that HCF-1 can indirectly promote pRB family inactivation, and thus, cellular proliferation. E2F-4, a member of the E2F family of transcription factors that regulate cellular proliferation in conjunction with the retinoblastoma family of proteins, is involved in repression of E2F responsive genes at G0/G1 and consequently, cell cycle arrest or differentiation. Overexpression of E2F-4 suppresses HCF-1-mediated rescue of cellular proliferation, indicating an antagonistic role for these proteins in the cell cycle. Together, these findings contribute to identifying additional HCF-1 interaction partners and may provide insight into the molecular mechanism of HCF-1-mediated cell cycle progression.

abstract: HCF-l, a transcriptional regulatory protein, was originally identified as an accessory factor for the induction of Herpes Simplex Virus immediate-early genes by the viral transactivator VPl6. Recently, HCF-1 has emerged as a chromatin-binding transcriptional co-regulator that plays an essential role in cellular proliferation. In order to further characterize the function of HCF-l and determine the mechanisms by which it contributes to cellular proliferation we have sought to identify novel HCF-1 interaction partners and elucidate their function. In this thesis, we describe the identification of key cell cycle regulatory proteins, Miz-1 and E2F-4, as novel HCF-1 interaction partners. Miz-1, a transcription factor that activates transcription of cell cycle inhibitory genes, is an integral part of the anti-mitogenic TGF-β pathway and contributes to cell cycle arrest following DNA damage and differentiation signals. HCF-1 associates with the Miz-1 transactivation domain and antagonizes Miz-1- dependent transcriptional activation of p15INK4b, a cyclin-dependent kinase inhibitor, suggesting that HCF-1 can indirectly promote pRB family inactivation, and thus, cellular proliferation. E2F-4, a member of the E2F family of transcription factors that regulate cellular proliferation in conjunction with the retinoblastoma family of proteins, is involved in repression of E2F responsive genes at GO/G1 and consequently, cell cycle arrest or differentiation. Overexpression of E2F-4 suppresses HCF-1-mediated rescue of cellular proliferation, indicating an antagonistic role for these proteins in the cell cycle. Together, these findings contribute to identifying additional HCF-1 interaction partners and may provide insight into the molecular mechanism of HCF-1-mediated cell cycle progression.

abstract: Doctor of Philosophy (PhD)


title: Cell Cycle and HEB Mediated Regulation of Gene Expression during Myogenic Differentiation

contributor:
Rudnicki, Michael A.
Medical Sciences

subject:
Medical Sciences
Medical Sciences

abstract: Embryonic studies clearly demonstrate that MyoD and Myf5 are required for specification of the myogenic lineage. Moreover, MyoD plays an essential role in initiating expression of myogenin and inducing differentiation. However, the factors and mechanisms which temporally regulate expression of myogenic genes are not fully understood. Furthermore, the controversy of whether cell cycle withdrawal precedes induction of MyoD transcriptional activity, or MyoD activity induces cell cycle withdrawal, still exist. In this thesis, I demonstrate that although MyoD transcriptional activity is regulated by cell cycle regulators, such as pRb, cdk4 and cyclin D 1, these molecules are functioning in a cell cycle-independent manner. In addition, MyoD regulates cell cycle progression, and more specifically S-phase entry, by regulating the stability of cyclin E. Moreover, MyoD regulates expression of cyclin Dl indirectly by modulating activation of NF-lCB. Importantly, I demonstrate how the E-protein, HEB, regulates myogenic gene expression in an isoform-specific, MRF-specific, and promoterspecific manner. In the absence of HEB, MyoD is unable to effectively induce expression of myogenin, and differentiation is inhibited. Therefore, ubiquitously expressed factors, such as pRb and HEB, are able to regulate the restricted pattern of gene expression in myogenic differentiation.

abstract: Doctor of Philosophy (PhD)


title: IMAGINING JUSTICE: THE POLITICS OF POSTCOLONIAL FORGIVNESS AND RECONCILIATION

contributor:
O`Brien, Susie
English

subject:
English Language and Literature
English Language and Literature

abstract: Possibly owing to a spirit of millenarianism, discourses of forgiveness and reconciliation have emerged as powerful scripts of interracial and interethnic negotiation in states struggling with the legacies of colonialism. This study examines the representation and production of these discourses in contemporary fiction by J.M. Coetzee, Joy Kogawa, David Malouf, and Michael Ondaatje. It argues that although they disconcel1 or stupefy critics situated in postmodern contexts, the rhetoric and rituals that structure reconciliation processes may be crucial to a departure from colonialist and racist relations, and to the commencement of a more democratic future. Using a postcolonial methodology, Imagining Justice challenges assumptions that discourses of forgiveness and reconciliation necessarily entail a rush to closure, repression of memory, or recuperation by power. Ultimately it suggests that if the prerogative of oppressed groups to devise their terms is conceded, forgiveness and reconciliation may render radical revision to prevailing systems of violence and injustice imaginable.

abstract: Doctor of Philosophy (PhD)


title: THE HIGH ENERGY COST OF WALKING IN CHILDREN AND ADOLESCENTS WITH SPASTIC CEREBRAL PALSY: PHYSIOLOGIC, ELECTROMYOGRAPHIC AND BIOMECHANICAL IMPLICATIONS

contributor:
Bar-Or, Oded
Medical Sciences

subject:
Medical Sciences
Medical Sciences

abstract: Six studies (Studies 1-6) were performed to gain insight into selected physiologic (metabolic, cardiorespiratory, thermoregulatory), electromyographic, and biomechanical implications of the high energy cost of walking in children and adolescents with mild cerebral palsy (CP). Controls (CON) were also tested in Studies 3 and 4. Studies 1 and 2 examined issues related to habituation to treadmill walking. The purpose of Study 1 was to determine if after one, 12-15-minute treadmill walking practice session: i) metabolic and cardiorespiratory responses during walking are affected by repeated walking bouts on different days, and ii) if these responses are different at different speeds. After 12-15 minutes of treadmill walking practice, subjects walked on the treadmill (3-minute bouts) at 60, 75, 90% of the fastest walking speed (FWS), on three different days. From Day 1 to Day 3, net ventilation ('VE) and net heart rate (HR) at 90% FWS decreased by 3.6 l'minute⁻¹ and 8 beats·minute⁻¹, respectively. There were no differences between Day 1 and Day 2 or Day 1 and Day 3 for any other metabolic or cardiorespiratory variable at any speed. Between-day reliability of most metabolic and cardiorespiratory responses was ~ 0.95. Since there were no Day 1 to Day 3 differences in metabolic variables, Day 1 to Day 3 decreases at 90% FWS in net HR may reflect reduced emotional stress over time and decreases in net VE, an uncoupling of oxygen uptake (V02) and VE. Despite between-day differences, it appears that reliable metabolic and cardiorespiratory data may be obtained in these subjects after one, 12-15-minute treadmill walking practice session. In Study 2 the subjects practiced walking on the treadmill as in Study 1 and, on a different day, they then walked once on the treadmill for three minutes, at 90% FWS. In this case, the purpose of the study was to determine: i) minute-by-minute differences in lower limb antagonist muscle co-activation and stride length during a 3-minute treadmill walk following 12-15 minutes of treadmill walking practice, and ii) if the minute-by-minute pattern of co-activation is affected by site (thigh or lower leg) and lower limb dominance. During the treadmill walk, non-dominant thigh co-activation decreased between minute 1 and a) minute 2 (6%), b) minute 3 (7.2%). Co-activation for the dominant lower leg decreased between minute 1 and minute 3 (11.3%). Non-dominant thigh coactivation was on average 27.3% higher than for the dominant thigh, independent of time. Thigh co-activation was on average 27.7% higher than for the lower leg, independent of dominance or time. Stride length increased between minute 1 and minute 3 by 2.1 %. These data suggest that 12-15 minutes of treadmill walking practice may be sufficient time to obtain stable co-activation and stable stride length by minute 2 of a fast treadmill walk. The data also suggest that dominance and site affect the magnitude of co-activation. The purpose of Studies 3 and 4 was to determine if children and adolescents with mild spastic CP differ from CON in their thermoregulatory responses during exercise in the heat, where such exercise would have the same oxygen (O2) cost for both groups (Study 3) and where such exercise would have a higher O2 cost for those with CP compared to CON (Study 4). Each subject with CP was individually matched to a CON. The CP subject and their CON-match arm-cranked (Study 3) or walked on the treadmill (Study 4) at the same intensity for three, 10-minute bouts in 35 °C, 50% relative humidity. In Study 3, there were no CP-CON differences in \/02 or in thermal strain. In Study 4, V02, body temperatures, and HR were higher in the CP group compared to CON (V02 was 40% higher, rectal temperature was 0.4 °C higher). Those with CP demonstrated greater thermal strain than CON during treadmill walking where they required more metabolic energy, and thus produced more metabolic heat than CON, but not during arm-cranking where their V02 was matched and heat production was therefore similar between the groups. The primary purposes of Studies 5 and 6 were to determine whether there was a relationship between the subjects' level of habitual physical activity (PA) and their 02 cost of walking (Study 5) or their biomechanical walking economy (Study 6). In both studies subjects walked on the treadmill at the same speeds and with the same amount of practice as in Study 1. HR (Study 5) and movement (Study 6) were also monitored over 2 weekdays and 1 weekend day. In Study 5 habitual PA (derived from monitored HR) was related (r = -.70 to -.84) to net V02 at 60 and 75% FWS, to net V02 m-1 , averaged across the three speeds, and to % peak \/02 at all three speeds. PA was not related to net \/02 at 90% FWS. In Study 6, biomechanical walking economy, as measured by the biomechanical economy quotient (SEQ), at 60, 75 or 90% FWS explained about half of the intersubject variance in PA as measured by accelerometer movement counts. A similar relationship was found between SEQ and accelerometer movement counts at or above the 80th and 90th percentile for both the total minutes d-1, and the number of 5-minute bouts d-1. The data from Studies 5 and 6 suggest that PA in these subjects may be related to their walking economy.

abstract: Doctor of Philosophy (PhD)


title: An Expert Performance and Deliberate Practice Analysis of Open Sport Referees

contributor:
Starkes, J.L.
Kinesiology

subject: Kinesiology Kinesiology

abstract: The deliberate practice theory and the expert performance approach were used to explore expertise in open-sport referees in four related studies. Study 1 used questionnaires focused on deliberate practice training activities. Findings showed that world-class level soccer referees specialize early in referee training activities, with an emphasis on physical training to the virtual exclusion of perceptual-cognitive training. Similar to studies with athletes, activities rated high in effort were also rated high in enjoyment. Distinct from studies with athletes, however, highly effortful activities were not always rated high in relevance. Study 2 combined biographical experience and practice data with performance on video-based laboratory tasks. Findings indicate that part of referee skill involves anticipation of movements, but not necessarily superior strategic decision-making. Studies 3 and 4 moved to the sport of basketball with more detailed tests of video-based laboratory tasks. Study 3 findings indicate that referee skill in video-based infraction detection and decision-making tasks may be influenced by features of the video display (e.g., speed and camera angle) and the inclusion of secondary, visual processing tasks. The visual processing style used to interpret and classify video clip actions may also interact with expertise level. Finally, study 4 indicates that the choice of game clips as well as their sequencing relative to the signals contained within needs to be examined closely when creating testing and training tools. As one of the first focused programmes of research on expertise in open-sport referees, this work highlights a number of areas of future research.

abstract: Doctor of Philosophy (PhD)


title: CONTESTED STRUCTURES: NATURE AND CULTURE IN EIGHTEENTH-CENTURY WRITING

contributor:
Walmsley, Peter
English

abstract: The two terms "nature" and "culture" can suggest a binary or oppositional structure. The general objective of this doctoral dissertation is to investigate the historical conditions under which the nature/culture opposition was produced in eighteenth-century British writing. I examine a set of specific configurations taken by the historical nature/culture dichotomy, but I also investigate the connections and continuities between formations of nature and culture that this dichotomy, understood as an oppositional structure, would seem to disavow. The concrete points of intersection thus revealed between constructions of nature and culture at times threaten to disrupt the entire dichotomy. As I undertake this critique, I ask how we may rethink the boundaries of this structure. In separate chapters of this thesis, I select art, natural history, and health practices as topical sites in terms of which the boundaries between nature and culture are being delineated, often quite provisionally, during the eighteenth century. Art is particularly relevant to my aim of exploring the boundaries between nature and culture, as a central question in eighteenth-century debates about art was whether or not the art object should be considered an expression of human fashions or natural forms. I also examine natural history, for its subject matter typically bridged normative boundaries between human and natural; many naturalists who wrote general histories of particular regions not only investigated natural phenomena such as animals, their environments, and the weather, but also incorporated descriptions of human social and economic relations into their accounts. Finally, I investigate practices of health that mediated a complex set of relations between leisured people in search of better health, certain cultural conceptions of healthy bodies, and the natural environments that these practices depicted as a primary source of good human health. In practical terms, each of these sites produces a different form of the nature/culture dichotomy, and so provides a unique perspective from which to consider its general structure and limits.

abstract: Doctor of Philosophy (PhD)


title: Crystallographic, Spectroscopic and Theoretical Studies of Fluoro- Kr(II), Xe(ID, Au(V) and Halogen(VII) Compounds; and New Synthetic Developments in Bromine(VII) Oxide Fluoride Chemistry

contributor:
Schrobilgen, G. J.
Chemistry

subject: Chemistry Chemistry

abstract: The structures of a-KrF2, [KrF][W'6] (M = As, Sb, Bi, Au) and several salts containing the Kr₂F₃⁺ cation have been determined by use of low-temperature single-crystal X-ray diffraction. These structures account for nearly all of the crystallographic work reported for Kr(ll) compounds, and represent the first studies of heir kind for salts containing the KrF⁺ and Kr₂F₃⁺ cations. The crystallographic characterization of the strongly fluorine bridged [KrF][MF₆] ion pairs prompted a more comprehensive survey of XeF⁺ salts, which included the X-ray structure determinations of [XeF][MF₆] (M = As, Sb, Bi), and [XeF][M2FU] (M = Sb, Bi). Variations in the Ng--Fb (Ng = Kr, Xe) bridge bond lengths of the NgF+ salts were used to assess the relative fluoride ion acceptor strengths of AsF 5, SbF 5, BiP 5, AuF 5, Sb2F 10 and BhF 10 and the results were compared with a recently reported Lewis acidity scale derived from electronic structure calculations. The potent oxidizer properties of the KrF+ cation have been used to synthesize [02][AuF6] by the reaction of [KrF][AuF6] with 02. A previously unknown and ordered phase of [02][AuFd was identified by variable temperature Raman spectroscopy and by single- crystal X-ray diffraction, and resulted in the reassignment of the V2(Eg} vibrational mode of AuF6-. The limited chemistry of Br(W) has been extended in several respects. Accurate geometric parameters for the previously known BrF6 + cation and its chlorine and iodine analogues have been determined by single-crystal X-ray diffraction, allowing bond length trends among the late period 3 - 5 hexafluoro-species to be established. The octahedral geometries of the XF6 + (X = CI, Br, I) cations in solution have been confirmed by the measurement of their 35,370, 79,81Br an.d 1271 NMR spectra an.d spin.-Iattice relaxation times (T1) in HF solution. The previously un.1rnown. fluoride ion acceptor properties of Br03F have been established by its reaction.s with [N(CH3)4][F], CsF, RbF, KF an.d NOF. The resulting Br03F2- anion is only the fourth example of a Br(VTI) species, with its predicted D3h symmetry having been. confirmed by vibration.al spectroscopy, 19F NMR spectroscopy, single-crystal X-ray diffraction an.d electronic structure calculations. The internal and symmetry force constants of Br03F2- have been determined and are compared with the isostructural species Xe03F2, Os03F2 and CI03F2-. The stronger fluoride ion. acceptor properties of Br03F relative to those of CI03F have been demonstrated by use electronic structure calculations and have helped to explain. failed attempts to prepare the 003F2- anion. The fluoride ion. don.or properties of Br03F and CI03F were investigated by their reactions with SbF5(l). Whereas CI03F does not react with SbFs(l), Br03F undergoes reductive elimination of 02 to form [Br02] SbnFsn+l]. The geometric parameters of the Br02 + cation have been obtained for the first time in the solid state by the X-ray structure determination of [Br02][SbF6]. The contrasting reactivities ofBr03F and CI03F towards (SbFs)n have been addressed by use ofthermochemical calculations. Attempts to prepare Br01F3 or salts containing the Br01Ft cation by ligand exchange reactions with Br03F and oxidative fluorination of Br02F were unsuccessful, but have been accounted for by use of electronic structure calculations which were employed to evaluate the thermochemistries of the attempted reactions.

abstract: Doctor of Philosophy (PhD)


title: A Kinetic Study of the Electron Stimulated Adsorption of Ammonia on Tungsten Single Crystal Surfaces

contributor:
Dawson, Peter T.
Chemistry

subject: Chemistry Chemistry

abstract: This thesis reports a comprehensive investigation of the effects of ammonia gas pressure, crystal temperature, electron beam current and angle of incidence on electron stimulated adsorption (ESA) of ammonia on W(100) and W(1lO) surfaces. An understanding of the kinetics of the ammonia dissociative adsorption has tremendous technological importance. AES studies on the interaction of NH3 with W(100) and W(110) have been conducted. The cross-section for ESA on W(110) is calculated to be 3.4x10-16 cm2. The ESA rate increases with ammonia pressure at very low pressures but becomes independent of it at higher pressures. The ESA rate is first order in electron beam current but decreases with increasing crystal temperature. Except at low pressures, the ESA rate is found coverage-independent over a large coverage range. The desorption energies of two precursor states found are calculated to be 120 kJ mol-I (N-W bonded) and 7 kJ mol-1 (H-bonded). All the evidence suggests a precursor state mechanism in which the activation sites and chemisorption sites are different. Yet it is inappropriate for a well-ordered single crystal surface and a novel alternative mechanism has been discovered. The electron beam study leads to an understanding of how different adsorbates (NH3, NH2, NH and N) make different contributions to the measured overall N AES signal, and the signal attenuation is related to the shielding of the N atom by the bonded H atoms. An adsorption mechanism involving concepts about vacant site exclusion and stimulated dissociation of adsorbates was used to simulate the coverage evolution of individual adsorbates. The Auger sensitivity factors describing the signal attenuation from hydrogen shielding and from the electron beam's incident angle were deduced. The factors and the simulated coverages combined to produce simulated AES data that match the experimental results and reproduce the apparent coverage-independence.

abstract: Doctor of Philosophy (PhD)


title: Inferential Methods for Censored Bivariate Normal Data

contributor:
Balakrishnan, Narayanaswamy
Mathematics

subject: Mathematics Mathematics

abstract: In this thesis, we consider inferential methods for a bivariate normal distribution based on Type-II right censored or progressively Type-II right censored data. We first propose the use of the Expectation-Maximization (EM) algorithm to determine maximum likelihood estimates (MLEs) based on Type-II right censored samples. We derive the asymptotic variances and covariances of the MLEs from the Fisher information (FI) matrix as well as from the partially observed information (POI) matrix by using the missing information principle. There are slight differences between the variances and covariances of the MLEs from the FI matrix and those from the POI matrix, but the advantage of the use of the POI matrix is that it does not require any extensive numerical integration as the FI requires. Next, we derive the MLEs and the asymptotic variance- ovariance matrix of the MLEs based on progressively Type-II right censored samples. To improve the coverage probabilities of the asymptotic confidence intervals (CIs) using the asymptotic normality of the MLEs, especially for the correlation coefficient, we propose to use sample-based Monte Carlo percentage points and the coverage probabilities of the CIs so obtained turn out to be closer to the nominal level. Next, we extend the use of the EM-algorithm to determine MLEs based on progressively Type-II right censored bivariate normal data, and derive the symptotic variances and covariances of the MLEs by using the missing information principle. We discuss the determination of optimal censoring schemes with respect to minimum trace as well as maximum information about p. Type-n right censoring is not to be recommended in general, and that the progressive censoring scheme (n - m, 0, ... ,0) is nearly as efficient as the best progressive censoring scheme for each combination of nand m considered. Finally, we propose three run-based and two rank-based nonparametric tests for independence between life-times and covariates from censored bivariate normal samples. The two rank-based test and the T test based on the sample correlation coefficient perform better (in terms of power) than the three run-based tests under bivariate normality. However, the R tests are robust (in terms of level of significance) when the samples come from a population with heavier tails than the normal distribution, such as the t distribution and the scale- utlier model.

abstract: Doctor of Philosophy (PhD)


title: The Heat Transfer and the Soot Deposition Characteristics in Diesel Engine Exhaust Gas Recirculation System Cooling Devices

contributor:
Ewing, Daniel
Chang, Jen-Shih
Mechanical Engineering

subject:
Mechanical Engineering
Mechanical Engineering

abstract: Exhaust gas recirculation (EGR) cooiing devices are used in EGR systems to significantly reduce NOx emissions from diesel engines. However, the thermal and hydraulic performances of these devices change over time during operation due to the deposition of soot from the diesel exhaust gas in these devices. The objective of this work was to investigate in detail the heat transfer and the soot deposition characteristics in diesel engine EGR cooling devices. Controlled soot deposition tests were performed on a series of generic single-tube and three-tube EGR cooling devices that were exposed to exhaust gas for ifferent periods of times in the diesel exhaust test facility to investigate the time-dependent heat transfer and pressure drop characteristics of these devices. A non-destructive technique was developed to characterize the three dimensional soot layers that occurred in the EGR cooling devices using the neutron radiography test facility of the McMaster Nuclear Reactor. The results showed that the deposited soot layer in the single-tube devices was much larger for the higher flow rate which corresponded to turbulent flow, particularly in the entrance region. The thickness of the deposited soot in the entrance region of the tube was much larger than the remainder of the tube, and appeared to restrict the flow area by up to 75% over a length of 4 tube diameters. The variation in the deposited soot thickness throughout the rest of the tube is similar in magnitude to the layer itself indicating that the soot layer in the tube was three- imensional. The results also showed that the profiles of the deposited soot had a wave-like structure in all cases. The thermal effectiveness of the devices decreased from approximately 82% to % over 5 hours for the laminar flow test case, and from 70% to 35% for the turbulent flow test. The pressure drop across these devices increased by up to 320% during the 5 hours of testing. Measurements were also performed using three-tube EGR cooling devices with 45° and 60° expansion angle inlet headers exposed to diesel exhaust for 3 hours. The soot deposition was more evenly distributed in the tube bundle with the 60° expansion angle inlet header suggesting that the flow may be more evenly distributed in this device. There was more soot deposited in the center tube than outer tubes in the three-tube bundle with the 45° expansion angle inlet header suggesting that the flow was not evenly distributed. The thermal effectiveness in both cooling devices decreased during the 3 hours of testing, but the change in the effectiveness was larger for the device with the 45° expansion angle inlet header. The pressure change in the exhaust gas across the cooling devices increased more rapidly for the device with the 45° expansion inlet header, reaching a nearly constant value of nearly 5 times the initiai value after 3 hours.

abstract: Doctor of Philosophy (PhD)


title: Mechanisms of transport of Na+, K+ and CI- in Malpighian tubules of Rhodnius prolixus and Drosophila melanogaster

contributor:
O`Donnell, Michael J.
Biology

subject: Biology Biology

abstract: Most insects regulate their haemolymph composition and volume within narrow ranges even when exposed to extreme or variable environmental conditions. Osmotic and ionic balance are maintained by the actions of the excretory system which consists of the Malpighian tubules and hindgut. In this thesis I examine the mechanisms of ion secretion involved in fluid secretion by Malpighian tubules of species faced with excess sodium or potassium in the diet. Malpighian tubules of the blood-feeder Rhodnius prolixus secrete Na + -rich fluid, whereas tubules of Drosophila melanogaster, which feeds on yeast growing on rotting fruit, secrete K+ -rich fluid. Of particular interest is the means by which tubules ofthese two species control the ratio of Na+ to K+ in the secreted fluid. My results show that K+ and Cl- are actively transported into the cells across the basolateral membrane of Malpighian tubule cells of both species through a bumetanidesensitive cotransporter driven by the electrochemical potential favouring Na+ entry. In Mapighian tubules of Drosophila most of the Na+ that enters through the bumetanidesensitive transporter is recycled back to the haemolymph through a Na+/K+-ATPase, resulting in secretion of a K+ -rich fluid. I hypothesize that the Na + /K+ ratio of the fluid secreted by tubules of Drosophila is modulated by the activity of the Na+ /K+ -ATPase. Serotonin-stimulated Malpighian tubules of Rhodnius do not recycle Na+ and secrete Na+-rich fluid. The secreted fluid Na+/K+ ratio varies with haemolymph composition, so that less K+ is secreted as haemolymph K+ concentration declines. This replacement of K+ by Na+ in the secreted fluid contributes to homeostasis by regulating the concentrations ofK+ and Na+ in the haemolymph.

abstract: Doctor of Philosophy (PhD)


title: On the Essential Unpredictability of Certain Human Actions and Certain Mechanical Processes in Certain Deterministic Systems

contributor:
Griffin, Nicholas J.
Philosophy

subject: Philosophy Philosophy

abstract: This work deals with the impossibility of full and precise prediction even of a domain of prediction which is supposed to be completely (metaphysically) determined by physical relations and regularities, and regardless of quantum mechanical limitations. The Laplacian notion of an Intelligence capable of complete prediction based on complete information is explored and shown to be impossible. It is further suggested that the impossibility of full prediction even of completely (metaphysically) determined systems, referred to as the property of "impredictfulness", bears striking similarities to the limitative results of Turing, Gödel and Tarski, regarding computational, syntactical and semantical properties of formal systems.

abstract: Master of Arts (MA)


title: Modulation of Intestinal Epithelial Physiology and Signal Transduction by Transforming Growth Factor-beta

contributor:
McKay, D.M.
Medical Sciences

subject:
Medical Sciences
Medical Sciences

abstract: Intestinal epithelia contribute to gut homeostasis by acting as a selectively permeable barrier and establishing a driving force for water movement through vectorial ion transport. These processes are affected by cytokines. As TGFß levels can be increased in gut inflammation, a situation where epithelial function is often altered. the aim of this thesis was to d.efine the effeets of TGFß on intestinal epithelial barrier and ion transport function. The first study characterized the kinetics and signal transduction pathway behind the novel observation that intestinal epithelial monolayers treated with TGFß display reduced stimulated secretory responses. The mechanisms involved in this process were further delineated in a second study where it was determined TGFp treatment causes a down-regulation and altered sub-cellular localization of the main apical chloride channel (CFTR). The final study defined the mechanism behind TGFp-induced epithelial barrier enhancement in terms of signal transduction pathways and regulation of proteins involved in maintaining a physiologically "tight" barrier. Furthermore, it was determined that TGFß treatment protects against barrier damage caused by pathogenic bacteria, and the mechanisms behind this have been revealed. The first two manuscripts present a substantial body of evidence on the kinetics and mechanisms of TGFß-induced diminished epithelial ion transport. In addition to furthering understanding of cytokine regulation of epithelial function, these data are particularly relevant to the field of enteric disease where water balance is often perturbed. In the tinal manuscript, the protective role of TGFß on epithelial barrier function is illustrated by its ability to preserve banier function from damage caused by the pathogenic bacteria. enterohemonhagic E. coli (EHEC) 0157:H7. Having determined mechanisms underlying ephhelial banier enhancement and protection by TGF~, potential therapeutic targets have been revealed that might be strategic in treating individuals with conditions of increased banier permeability. such as inflammatory bowel disease relapses and EHEC infection.

abstract: Doctor of Philosophy (PhD)


title: GEOMETRIC AND QUASI-STATIC THERMAL ERROR COMPENSATION OF A LASER DIGITIZER ON A COORDINATE MEASURING MACHINE

contributor:
Spence, Allan D.
Mechanical Engineering

abstract: Coordinate measuring machines (CMM) are widely used in inspection and reverse engineering. There is increasing interest in using optical sensors, such as laser digitizers, to take advantage of their high data acquisition rates and the fact that they are a non-contact measurement suitable for soft materials or delicate parts. The issue to be addressed is the fact that the sensors and CMMs are made by different manufacturers, so there is no integration of the error compensation scheme. As well, unlike conventional touch trigger probes, correction of the laser digitizer pose must be explicitly incorporated. The purpose of this study was to develop a mathematical algorithm that would improve the accuracy of data collected with a laser digitizer mounted on a CMM. To this end, an algorithm was developed to compensate for the variations in digitizer pose. It compensates for both positional errors and angular errors, whether caused by CMM geometric component error or quasi-static thermal error. To implement and verify the error compensation, tests were made using a Hymarc laser digitizer mounted on a DEA Iota 1102 CMM. The thesis proposes using an optical ballbar, an adaptation of the traditional ballbar recommended by ASME Standard B89.4. The scan plane coordinates of the digitizer. the CMM axis scale positions and temperatures were recorded simultaneously in real time. The CMM error compensation algorithm was then used to post process the data to obtain improved global part coordinates. Accuracy of a laser equipped CMM is improved from 67 um to 17 um. The benefits of using optical sensors can be improved by incorporating this error compensation scheme into an integrated optical metrology system.

abstract: Doctor of Philosophy (PhD)


title: FLEXIBILITY IN CATEGORIZATION AS A FUNCTION OF VARIABILITY OF REPRESENTATION TYPE: STUDIES IN FEATURE WEIGHTING AND CATEGORICAL BIASING

contributor:
Brooks, L. R.
Psychology

subject: Psychology Psychology

abstract: For nearly the last fifty years, most research on the acquisition and application of conceptual knowledge has focused on structural relations and abstract descriptions as the composing a concept. In this thesis I show that conceptual content is much richer than this, and includes instantiated forms of knowledge as well as abstract descriptions. This instantiated knowledge, both at the featural and procedural level, is necessary to explain error patterns in probe and biasing studies. Furthermore, this variety in content is shown to be systematically linked to different decision patterns, providing an explanation for the flexibility of categorization. Much critical learning done in concept formation, therefore, involves learning optimal feature descriptions and task-appropriate procedures. These ideas are discussed in terms of embodied cognition.

abstract: Doctor of Philosophy (PhD)


title: Psychologism, Semantics and the Subject Matter of Logic

contributor:
Griffin, Nicholas
Philosophy

subject: Philosophy Philosophy

abstract: Despite a pronounced rejection of psychologism at the turn of the previous century, contemporary epistemology has witnessed its pervasive return. This inquiry seeks to contribute to a philosophical resolution of the psychologism de bate, not by defending antipsychologism against its historical and contemporary objectors, but by offering a perspective from which a viable anti-psychologism might be articulated. Psychologism about logic is a family of views asserting a dependency of logic on psychology. Typically, such a dependence jeopardizes the objectivity and necessity of logic. Frequently, this dependency is established through the metaphysical claim that the subject matter of logic is psychological in nature. Metaphysical accounts of logic explain its status and foundation in terms of its subject matter. Standard accounts have portrayed the subject matter of logic as a class of mental entities (ideas), abstract entities, or concrete, particular entities. Following a review of Frege's critique of psycho logism (the first option), I consider historical representatives of the two remaining alternatives: Frege's Platonism and Mill's empiricism. Witnessing the failings of each of these theories, I turn to a positivistic account which provides logic with a linguistic, rather than a metaphysical, foundation. As an alternative to metaphysical accounts, I consider the view that logic has no subject matter. I argue that metaphysical accounts of logic may be equivalently expressed as theses concerning the semantics of the logical lexicon. Specifically, the question of psychologism may be seen as the question of how to properly explain the semantics of the logical lexicon. I engage Quine's response to positivistic accounts of logic, arguing that his naturalised holism misconstrues logic's function in theory and its fuundation. I suggest that a pragmatic account of logic, focussing on the linguistic function of logical expressions in our language, may provide a viable alternative for explaining the nature and foundation of logic.

abstract: Doctor of Philosophy (PhD)


title: MUSCULOSKELETAL CHANGES AFTER SPINAL CORD INJURY: EFFECTS OF BODY WEIGHT SUPPORTED TREADMILL TRAINING

contributor:
McCartney, Neil
Kinesiology

subject: Kinesiology Kinesiology

abstract: The overall focus of this thesis was musculoskeletal changes after individuals with spinal cord injury. The bulk ofthe thesis investigated the impact of a rehabilitation intervention, namely body weight supported treadmill training (BWSTT), on skeletal health and muscle atrophy in individuals with acute and chronic spinal cord injury (SCI). The first two studies in this thesis were methodological in nature. The first revealed that the presence of metal in a dual-energy x-ray absorptiometry scan results in reproducible errors in estimations of bone mineral content and body composition. The second study demonstrated that mid-tibia speed of sound measurements obtained with quantitative ultrasound might not reveal the changes that occur in the skeleton after SCI. These studies impart an important contribution to the area of osteoporosis diagnosis in individuals with SCI. The two longitudinal prospective studies presented here add to the growing body of literature that BWSTT can improve ambulation in individuals with chronic and acute incomplete SCI. Individuals participating in regular BWSTT improved their walking abilities on the treadmill, and some individuals improved their over ground walking abilities. The studies in this thesis are the first to investigate the impact of BWSTT on bone and muscle together in individuals with acute and chronic SCI. BWSTT had a positive impact on muscle, in that significant increases in lean mass and muscle cross- ectional area were observed after training in both acute and chronic SCI. BWSTT did not appear to have an impact on the skeleton, but further research is required to confirm these findings. Ultimately, it appears that individuals with SCI stand to benefit from BWSTT and the benefits are not limited to improved ambulation.

abstract: Doctor of Philosophy (PhD)


title: BATCH PROCESS IMPROVEMENT USING LATENT VARIABLE METHODS

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

subject:
Chemical Engineering
Chemical Engineering

abstract: This thesis deals with the following four topics: 1. Multivariate statistical methods are used to analyze data from an industrial batch drying process. Principal Component Analysis (PCA) and Partial least-squares (PLS) methods were able to isolate which group of variables from the initial conditions and the process variables were related to a poor-quality product. The use of a novel approach to the time warping of the trajectories for batches, and the subsequent use of the time-warping information, is presented. 2. In the procedure to monitor a new batch using the method proposed by Nomikos and MacGregor (1994), an assumption about the unknown future samples in the batch has to be taken. This work demonstrates that using the missing data (MD) option and estimating the score with an appropriate method are equivalent to the use of an adaptive-expansive multivariate time series model in the forecasting for the unknown future samples. The benefits of using the MD option are analyzed on the basis of (i) the accuracy of the forecast, (ii) the quality of the score estimates, and (iii) the detection performance during monitoring. 3. laeckle and MacGregor (1998) introduced a technique to estimate operating conditions in order for a process to yield a product with a desired set of characteristics. This thesis provides a detailed study of the application of such technique in designing the operation of a batch process. The original technique is modified to include constraints and other optimal criteria onto the desired quality and the trajectories. A parallel approach based on derivative-augmented models is proposed to avoid the analysis of the null space. 4. An extension to the work by laeckle and MacGregor (2000) in solving the product transfer problem is proposed. The early technique does not consider all the data structures involved in the problem and particularly the operating conditions from the source plant. The Joint-Y PLS model is presented as an alternative to solve this problem using all the available data.

abstract: Doctor of Philosophy (PhD)


title: Putting Health in its Place: Women's Perceptions and Experiences of Health in Hamilton's North End.

contributor:
Herring, D. Ann
Anthropology

subject: Anthropology Anthropology

abstract: This study explores the self perceived health status and health priorities of a diverse group of women living in the highly industrialized and stigmatized North End neighbourhood of Hamilton, Ontario. Through the use of qualitative methods such as indepth interviewing, focus group discussion, and participant observation, this medical anthropology research locates the health of the study participants (n = 46) within their neighbourhood, explores their experiences in this environment, and examines their understanding of the relationships between those experiences and their health. Guided by biocultural and critical interpretive perspectives, the study focuses on the personal knowledge and interpretations that women themselves assign to health concerns in their communities. The North End women in this study understand health as a multidimensional concept and articulate the ways in which their overall health and well being is enhanced and/or compromised by a variety of place-based characteristics. Despite the fact that they reside in the same neighbourhood, they offer diverse opinions about the effects that neighbourhood attributes have on their health. These differences reflect the variability in participants' health status and needs, socio-demographic circumstances, feelings of personal agency, satisfaction levels, time spent in the neighbourhood on a daily basis, and expectations of their neighbourhood. Because health experiences are embedded in everyday life, I assert that women's own perspectives, experiences and priorities must be incorporated into place-based health research and integrated into program and policy development. Women provide an invaluable and rich form of experiential knowledge about their health and their environment that differs from the "objective facts" put forth by outside individuals with no vested interest in the neighbourhood. Place is an important determinant of health that warrants serious attention by medical anthropologists who thus far have tended to view it merely as a backdrop for their research.

abstract: Doctor of Philosophy (PhD)


title: ADAPTIVE SCHEDULING FOR AN INCREMENTAL FLEXIBLE -FORGING CELL

contributor:
Nye, Tim
Spence, Allan
Metzger, Don
Mechanical Engineering

abstract: An adaptive forging schedule procedure that targets forging simple 3-D external profiles on a flexible forging cell is presented. The cell is composed of a numerically controlled press, a robot for workpiece manipulation, a shape feedback system and a main supervisory computer. The scheduling procedure utilizes the shape error, computed from the required and the initial workpiece shapes, to plan and execute a set of forging steps. The feedback system is then used to capture the deformed shape of the workpiece and update the shape error to adaptively plan the next set of forging steps. This adaptive control loop iterates until the workpiece shape is forged within a preset tolerance. The reduction in height and the bite values used in the schedule are limited by a set of technological bounds. Several of those bounds were identified and modelled as constraints on the adaptive scheduling procedure. Illustrative case studies showed that the adaptive scheduling procedure successfully forged external profiles (given an arbitrarily set tolerance limit) when a-priori approaches failed. The studies also showed that the new scheduling procedure could forge 2-D and 3-D profiles as easily (in terms of programming effort) as forging a uniform billet. Three new spread prediction models are developed, of which the newly developed Incrementally Updated Upper Bound model proved to provide the most accurate spread estimate compared to other developed and traditional spread prediction models. This model was then chosen to be integrated with the adaptive scheduling procedure to form an intelligent forging schedule procedure. The integration provided predictive capabilities to the adaptive scheduling module and enabled the generation of better quality forging schedules. In a typical example the number of forging steps in the forging schedule were reduced from six (using the adaptive scheduling procedure) to two (using the intelligent scheduling one).

abstract: Doctor of Philosophy (PhD)


title: Spatially Explicit Habitat Characterization, Suitability Analysis, Verification, and Modelling of the Yellow Perch Perca f1avescens (Mitchell 1814) Population in Long Point Bay, Lake Erie

contributor:
Minns, Charles K.
Biology

subject: Biology Biology

abstract: Different approaches were used to characterize, assess, test and model the fish-habitat interactions of yellow perch in Long Point Bay. Chapter 1 describes the methodologies for explicitly characterizing spatial and temporal habitat through mapping and modelling. Chapter 2 connects habitat and ontogenetic niche shifts in perch life history, with the aim of determining suitable habitat availability for the Long Point Bay perch population. Habitat suitability indices and models were used to map and identify the areas of suitable habitat, including thermal habitat. Chapter 3 compares a known distribution of yellow perch larvae with HSI predictions of habitat suitability as a validation exercise. Abundance and size distributions from the survey were compared to thermal and HSI predictions of suitable habitat to test for correspondence. The relationship between food availability and habitat characteristics, especially vegetation, were also tested. A model was developed in Chapter 4 that concentrated on the first year of life and the effect of consecutive constraints on early life stages with different habitat requirements. The purpose of the model was to compare the potential growth and survival of consecutive life stages in a spatially explicit manner when different habitat-based rules are imposed. The results highlight the importance of life history theory and knowledge of mechanisms used in habitat selection for determining limits to fish production.

abstract: Doctor of Philosophy (PhD)


title: ADAPTIVE DIGITAL FILTERING FOR COHERENT MTI RADAR

contributor:
Haykin, S.
Electrical Engineering

abstract: Doctor of Philosophy (PhD)


title: Facial Resemblance Affects Behaviour and Attributions

contributor:
Wilson, Margo
Daly, Martin
Psychology

subject: Psychology Psychology

abstract: Two lines of reasoning predict that highly social species will have mechanisms to influence behaviour towards individuals depending on their degree of relatedness. First, inclusive fitness theory (Hamilton, 1964) leads to the prediction that organisms will preferentially help closely-related kin over more distantly-related individuals. Second, evaluation of the relative costs and potential benefits of inbreeding suggests that the degree of kinship should also be considered when choosing a mate. In order to behaviourally discriminate between individuals with different levels of relatedness, organisms must be able to discriminate cues of kinship. Facial resemblance is one such potential cue in humans. Computer-graphic manipulation of face images has made it possible to experimentally test hypotheses about human kin recognition by facial phenotype matching. I show that humans respond to facial resemblance in ways consistent with inclusive fitness theory and considerations of the costs of inbreeding, namely by increasing prosocial behaviour and positive attributions toward self-resembling images and selectively tempering attributions of attractiveness to other-sex faces in the context of a sexual relationship. The four studies presented in this thesis use face images made to resemble either the experimental participants or unfamiliar people in order to test the impact of facial resemblance on behaviour and attributions. In Chapter 2, I demonstrated that people favour individuals represented by resembling faces in an economic game. In chapter 3, I tested the hypothesis that men, because of paternity uncertainty, should be more sensitive to phenotypic cues of relatedness to children than women should be. Although facial resemblance increased the attractiveness of and self-reported willingness to invest in pictured children, I found no evidence for a greater effect in men than women. To test whether responses to a kinship cue are sensitive to contexts in which the adaptive response should be different, I tested the perceived attractiveness of same-sex and other-sex self-similar faces in Chapter 4. Although self-resemblance increased the perceived "averageness" of male and female faces equally, self-resemblance increased the attractiveness of same-sex faces only. Additionally, in Chapter 5 I tested other-sex faces for trustworthiness, attractiveness in the context of a long-term relationship, and attractiveness in the context of a short-term relationship. Self-resemblance of other-sex faces increased attributions of trustworthiness, had no effect on attractiveness for a long-term relationship, and decreased attractiveness for a short-term relationship. The results of these four studies indicate that humans respond to self-resembling faces in ways that are consistent with facial resemblance being a cue of kinship. Nonadaptive hypothesis explaining these results as byproducts of general perceptual mechanisms were tested and not supported. Specifically, the finding that same-sex faces were perceived as no more average than other-sex faces was evidence against the hypothesis that separate mental representations of male and female faces could explain the increased attractiveness of same-sex self-resembling faces relative to other-sex selfresembling faces in Chapter 4. The opposite responses to an other-sex self-resembling face for judgments of trustworthiness versus judgments of attractiveness in the context of a short-term relationship in Chapter 5 provided evidence against the "mere familiarity" hypothesis whereby exposure globally increases liking. Consequently, responses to facial resemblance seem best interpreted as evidence of specialized adaptations to the problems of kin recognition in the domains of mate choice and prosocial behaviour.

abstract: Doctor of Philosophy (PhD)


title: Numerical Simulation of a Single Screw Plasticating Extruder

contributor:
Vlachopoulos, J.
Chemical Engineering

abstract:
A fully-predictive steady-state computer model has been developed for a single screw plasticating extruder. Included in the model are:

(i) a model for the flow of polymer solids in the feed hopper,

(ii) a variation of the Darnell and Mol model for solids flow in the extruder screw channel,

(iii) a modification of the Tadmor melting model for the melting zone in the screw channel,

(iv) an implicit finite difference solution of the conservation of mass, momentum and energy equations for the flow of the polymer melt in the screw channel and die, and

(v) a predictive correlation for the extrudate swell at the die exit.

A temperature and shear rate dependent viscosity relation is used to describe the melt flow behaviour in the model. The parameters in the viscosity relation are obtained by applying regression analysis to Instron capillary rheometer data. Extrudate swell theories developed for capillary rheometers have been utilized in the development of the correlation are the prediction of the extrudate swell at the extruder die exit. The parameters in the correlation are obtained by applying regression analysis to Instron extrudate swell data.

Given the material and rheological properties of the polymer, the screw geometry and dimensions, and the extruder operating conditions (i.e. screw speed, barrel temperature profile, etc.), the following are predicted:

(i) mass flow rate of the polymer,

(ii) pressure and temperature profiles along the extruder screw channel and in the die, and

(iii) extrudate swell at the die exit.

The overall extruder model predictions have been confirmed with experimental results from a 1 1/2 inch (38 mm) diameter, 24:1 L/D single screw extruder with a 3/16 inch (4.76 mm) diameter cylindrical rod die. High- and low-density polyethylene resins were used.

abstract: Doctor of Philosophy (PhD)


title: Learning-by-Doing in Dynamic General Equilibrium Models: Macroeconomic Implications and Estimates

contributor:
Johri, Alok
Economics / Economic Policy

subject: Economics Economics

abstract: This thesis develops and estimates a structural model in which organizations, engaged in the process of production, acquire knowledge that raises their productivity. This knowledge is treated as an organization specific capital good, that is jointly produced with output and embodied in the organization itself. This organizational capital is accumulated subject to an accumulation technology that implies production units faces a trade-off between maximizing current period profits and losing future productivity increases. This thesis shows that this dynamic structure, which has previously been ignored in existing studies of learning-by-doing, might have important economic implications. The results presented in this thesis contribute to our knowledge of the macroeconomic effects associated with the accumulation of organizational capital by focusing exclusively upon the accumulation of organizational capital by production units. This thesis establishes that when production experience is accumulated and stored by production units the implied values of several key macroeconomic variables in the non-stochastic steady state will be quite different to those implied by an otherwise identical model that ignores the accumulation of organizational capital. It is also shown that the accumulation of organizational capital generates a hump-shaped dynamic response of output to a fiscal policy shock. This hump-shaped output response is an important feature of the empirical dynamic responses. More importantly, a model that ignores organizational capital is unable to produce dynamic responses in output and investment that exhibit this hump-shaped response. Consequently, the dynamic responses associated with the accumulation of organizational capital might be consistent with the stylized facts associated with the empirical responses. These results suggest that the accumulation of production experience by production units will likely to be an important component of the endogenous propagation mechanism identified by Cooper & Johri (2002). These macroeconomic effects arising from the accumulation of organizational capital rely critically upon the existence of a dynamic structure, at the plant level, associated with the accumulation of organizational capital. The results presented in this thesis suggest that this dynamic structure will be empirically important for production units across a diverse range of (manufacturing) industries. Consequently, existing studies of learning-by-doing that aim to quantify the productivity of (accumulated) production experience without also considering the (endogenous) accumulation of this production experience are likely to be seriously flawed.

abstract: Doctor of Philosophy (PhD)