title: DESPAIR AND DISINTEGRATION IN AYI KWEI ARMAH'S THE BEAUTYFUL ONES ARE NOT YET BORN AND FRAGMENTS

contributor:
Bishop, Alan
English

abstract: The thesis explores the dominant themes of Armah's novels the despair and social fragmentation that plague post-Independence Africa. These themes are treated in varying degrees 1n all of Armah's five novels: The Beautyful Ones Are Not Yet Fragments, Why Are We So Blest?, Two Thousand Seasons and The Healers. In each of them, however, the time, setting and focus are different. However, his conviction that Africa's vision has been impaired because she traded her traditional values for unsuitable alien ones, with the resultant tension in family and social relationships, is consistent. Because of length restriction, this thesis focuses on The Beautyful Ones Are Not Yet Born and Fragments, Armah's first two novels. However, an attempt 1S made to generalize the Ghanaian experience in these two novels to embrace the whole of Africa, by making comparisons with and drawing parallels to the rest of his novels as well as novels by other African writers, notably Achebe and Ngugi. The first two chapters deal almost exclusively with Armah's literary treatment of the botched-up political experiment of Independence. The concluding chapter examines the likely political future of Ghana (and Africa) vis-a-vis current political events and the dominant themes of armah's novels, for which he Appendix provides political and historical background.

abstract: Master of Arts (MA)


title: Avison and the Metaphysicals

contributor:
Roebuck, W. G.
English

subject:
English Language and Literature
English Language and Literature

abstract: This study seeks to prove that Margaret Avison can justifiably be considered a metaphysical poet. An analysis is made of the historical, socio-cultural and political conditions that formed Herbert, Vaughan, and Hopkins. The intention is to show that Avison has been subjected to similar stresses during her lifetime as were the metaphysical poets, and that one finds in her work as in theirs evidence revealing a metaphysical tendency of mind. It is shown that Herbert, Hopkins and Avison all perceive the universe as being Christocentric and that all four poets are particularly concerned with the God-Christ-man relationship.

abstract: Master of Arts (MA)


title: Collective Memory and Performance: An Analysis of Two Adaptations of the Legend of Beatrice Cenci

contributor:
Kehler, Grace
York, Lorraine
Fast, Susan
English and Cultural Studies

subject: Canadian Opera

subject: Beatrice Chancy

subject: Beatrice Cenci

subject: George Elliott Clarke

subject: Percy Bysshe Shelley

subject: Dramatic Literature, Criticism and Theory

subject: Literature in English, British Isles

subject: Literature in English, North America

subject: Musicology

subject: Other Race, Ethnicity and post-Colonial Studies

subject: Performance Studies

abstract: This study focuses on two incarnations of the Cenci legend: Percy Bysshe Shelley’s 1819 verse drama The Cenci and George Elliott Clarke and James Rolfe’s 1998 chamber opera Beatrice Chancy. Shelley composed The Cenci after he discovered an Italian manuscript recounting the life of Beatrice Cenci who, after being raped by her father, plotted the murder of the debauched patriarch and was subsequently executed for parricide. Nearly two centuries later, Clarke and Rolfe created Beatrice Chancy, an Africadianized adaptation of the Cenci legend inspired by Shelley’s play. This study investigates they way in which multiple performance genres re-embody history in order to contest collective memory and reconfigure concepts of nationhood and citizenship. It examines the principles of nineteenth-century closet drama and the way in which Shelley's play questions systems of despotic, patriarchal power by raising issues of speech and silence, public and private. This is followed by a consideration of how Clarke and Rolfe's transcultural adaptation uncovers similar issues in Canadian history, where discourses of domestic abuse come to reflect public constructs of citizenship. Particularly this study examines how, through the immediacy of operatic performance and the powerful voice of the diva, Beatrice Chancy contests Canada’s systematic silencing of a violent history of slavery and oppression.

abstract: Master of Arts (MA)


title: DIABETIC MYOPATHY: CHANGES TO CONTRACTILE FUNCTION, MORPHOLOGY AND REGENERATIVE CAPACITY OF SKELETAL MUSCLE IN A MURINE MODEL OF TYPE 1 DIABETES MELLITUS

contributor:
Hawke, Thomas J
Medical Sciences

subject:
skeletal muscle
type 1 diabetes
injury
regeneration
growth
pathology
Musculoskeletal Diseases
Musculoskeletal Diseases

abstract: Type 1 diabetes mellitus (T1DM) is a disease defined by its complications as much as its central pathology. One such complication, diabetic myopathy, has received more attention in recent years as it has become clear that by maintaining a healthy skeletal muscle mass, diabetic individuals are more likely to maintain metabolic control and avoid the health consequences associated with hyperglycemia. While only a limited number of studies have been performed on diabetic human skeletal muscle, the research clearly indicates that a loss of muscular strength and alterations in muscle phenotype are a result of T1DM, occurring within weeks of disease inception. Studies employing rodent models of T1DM have identified several key changes underlying the loss of contractile capacity and the changes to muscle phenotype. The research to date, however, has yet to thoroughly elucidate the mechanisms underlying diabetic myopathy. The goal of the following studies is to gain a more thorough understanding of the effects of T1DM on skeletal muscle contractile capacity, morphology, and regenerative capacity using the C57BL/6J-Ins2Akita (Ins2WT/C96Y) diabetic mouse model. Given the crucial role of muscle repair in maintaining a healthy muscle mass, any deficit observed here could have important implications in the pathophysiology of diabetic myopathy. The results of the following studies indicate that the Ins2WT/C96Y mouse undergoes a loss of glycolytic muscle mass and other morphological/phenotypic alterations concomitant with loss of peak contractile force. Furthermore, the regenerative capacity of the muscle following injury is impaired in glycolytic muscle groups, particularly the tibialis anterior (TA). This impairment in regeneration can be, at least partly, attributed to chronic elevation in plasminogen activator inhibitor-1 (PAI-1). Pharmacological inhibition of this hormone improves regeneration of the TA in the Ins2WT/C96Y mouse. These data have improved our mechanistic understanding of diabetic myopathy and have clinical implications for the treatment of T1DM.

abstract: Doctor of Philosophy (PhD)


title: Towards a Microsimulation Residential Housing Market Model: Real Estate Appraisal and New Housing Development

contributor:
Kanaroglou, Pavlos
Darren Scott; Antonio Paez
Darren Scott; Antonio Paez
Geography and Earth Sciences

subject: real estate appraisal; new housing development; microsimulation; housing market

subject: Human Geography

subject: Quantitative, Qualitative, Comparative, and Historical Methodologies

subject: Statistical Models

subject: Urban Studies and Planning

subject: Human Geography

abstract: As a mid-size industrial city in North America, the City of Hamilton has been increasingly experiencing urban sprawl in the past six decades coupled with population growth and economic development. The study of various interdependent processes driving the evolution of urban form requires the application of simulation models that offer urban planners and policy-makers an efficient means for evaluating urban development policies. This thesis focuses on the modeling efforts towards building a microsimulation residential housing market system for the City of Hamilton. To this end, two major tasks have been conducted in this research. First, a state-of-the-art agent-based microsimulation housing market framework has been designed. Second, two model components in the microsimulation framework, namely a real estate appraisal model and a new housing development model, have been estimated. The objective of the real estate appraisal model is to assess the market values of existing dwellings based on the housing transactions in the previous period. Thre e model forms, including a traditional hedonic model, a spatial regression model, and a regression Kriging model, have been employed in estimations for comparison purposes. A series of independent variables that describe the characteristics of dwelling, location, and neighborhood are specified in the explanatory model. The comparisons among estimation results demonstrate that the spatial regression model has achieved a higher goodness-of-fit than the traditional hedonic model. In addition, we verified that spatial autocorrelation is present in the residuals of the traditional hedonic model, which is explicitly captured by the spatial regression model. In terms of model prediction accuracy, spatial models (SAR and Kriging) both achieve a certain level of improvements over the traditional hedonic model. Overall, we end up recommending that the SAR model is more appropriate to be incorporated into the microsimulation framework, as it provides the best match between predicted and observed values. The new housing development model enables the development of a dynamic housing supply module in the simulation framework by modeling the location and type decisions during the housing development process for each year. A parcel -level two-tier nested-logit model has been estimated. The model is able to deal with not only the decision to develop a specific vacant residential land parcel, but also the development type choice. In terms of the factors influencing the decision to develop, the picture revealed from the model estimation results is that land developers are more likely to start a development project in greenfields than in brownfields. As for the type choice decision during the development process, a variety of variables describing transportation accessibility, residential amenities, the characteristics of the land parcel and neighborhood are included in the model specifications.

abstract: Master of Arts (MA)


title: Variable Transition Time Predictive Control

contributor:
Mohrenschildt, Martin von
Down, Doug
Down, Doug
Computing and Software

subject:
optimal control
variable sampling
receding horizon control
Controls and Control Theory
Process Control and Systems
Controls and Control Theory

abstract: This thesis presents a method for the design of a predictive controller with variable step sizes.Predictive methods such as receding horizon control (or model predictive control) use aa fixed sampling frequency when updating the inputs. In the proposed method, the switchingtimes are incorporated into an optimization problem, thus resulting in anadaptive step-size control process. The controller with variable timesteps is shown to require less tuning and to reduce the number of expensive model evaluations.An alternate solution approach had to be developed to accommodate the new problem formulation.The controller's stability is proven in a context that does not require terminal cost or constraints.The thesis presents examples that compare the performance of the variable switching time controllerwith the receding horizon method with a fixed step size. This research opens many roads for futureextension of the theoretical work and practical applications of the controller.

abstract: Doctor of Science  (PhD)


title: The Electrophoretic Deposition of Conjugated Polymer Functionalized Carbon Nanotubes for Photovoltaic Applications

contributor:
Botton, Gianluigi
Zhitomirsky, Igor
Adronov, Alex
Materials Science and Engineering

subject:
electrophoretic deposition
conjugated polymer
carbon nanotubes
organic solar cell
photovoltaic
electrodeposition
Polymer and Organic Materials
Polymer and Organic Materials

abstract:
This experimental research thesis describes the combination of conjugated polymers and carbon nanotubes with the fields of electrophoretic deposition (EPD) and organic solar cells. Prior to these contributions, soluble conjugated polymers and carbon nanotubes that have been functionalized by them had not yet been deposited by EPD from solution or by using non-toxic solvents. Additionally, EPD had not yet been utilized to deposit the active layer in a solid organic photovoltaic device.
The EPD of soluble conjugated polymer functionalized carbon nanotubes from non-toxic solvents was achieved through an iterative process of experimentation and technique refinement. The developed EPD technique utilized the high pH region at the cathode substrate to neutralize positively charged weak polyelectrolytes macromolecules. Their functional groups were protonated using a minimized amount of acetic acid which also enabled their solubility. Deprotonation of the quaternary ammonium functional groups rendered them neutrally charged and insoluble tertiary amines. This mechanism facilitated the formation of coatings that were predictable and uniform in appearance and thickness.
Control over coating thickness was demonstrated by coatings spanning 100 nm to 10 μm. These coatings were produced by adjusting the applied voltage, solution concentration, and tuning the deposition duration.
Techniques for the fabrication of a photovoltaic device using an active layer produced by EPD were established though modifications of general organic photovoltaic device fabrication procedures. These modifications involved redesigning the photolithographic ITO etching pattern, adding an insulating barrier strip, thickening the aluminum electrode layer, and switching the top buffer layer from LiF to BCP.

abstract: Master of Applied Science (MASc)


title: Studies on a RNA Polymerase Induced in L-Cells Infected with Vesicular Stomatitis Virus

contributor:
Prevec, L.A.
Biology

subject: Biology Biology

abstract: A RNA dependent RNA polymerase induced in L-cells infected with VSV was studied. The in vitro properties of this enzyme and the nature of its synthesized products were examined. The products were characterized in terms of size, poly A content, and homology of both the infectious and defective particles of VSV. Analysis of this enzymatic activity during interference indicated a direct correlation between the in vitro activity and the in vivo interference.

abstract: Doctor of Philosophy (PhD)


title: DNA Base Complexes of Platinum and the Antitumor Action of cis-Pt(NH₃)₂Cl₂

contributor:
Lock, C.J.L.
Chemistry

subject: Chemistry Chemistry

abstract: A previously unknown mode of binding of platinum complexes to the DNA bases is described. The binding mode is characteristic of cis and not trans-Pt(NH₃)₂Cl₂ and is thought to be related to the ability of cis compounds to form hydroxobridged dimers. It is suggested that the differing anticancer activity of cis and trans-Pt(NH₃)₂Cl₂ may result from this difference in chemistry which is based on the differing stereochemical requirements of cis and trans isomers.

abstract: Doctor of Philosophy (PhD)


title: A Systematic Review of Head-to-Head Comparison Studies of the Roland-Morris and Oswestry Measures' Abilities to Assess Change

contributor:
Stratford, Paul W.
Letts, Lori
Spadoni, Gregory
Health Sciences

subject:
Roland Morris Questionnaire
Oswestry Disability Index
Systematic Review
Sensitivity to Change
Quality Criteria Form
Physiotherapy
Physiotherapy

abstract:
Low back pain (LBP) is a common musculoskeletal condition that can lead to pain, functional limitations and disability. Due to the prevalence of LBP, multiple self-reported outcome measures have been developed, which have resulted in redundancy in the literature. Two frequently used outcome measures are the Roland Morris Questionnaire (RMQ) and the Oswestry Disability Index (ODI). Few authors have performed head-to-head comparison studies to determine which of these outcome measures are the most successful at measuring sensitivity to change. The purpose of this thesis was to answer the question: Is there a difference in the sensitivity to change between the RMQ and the ODI in their ability to measure pain-related functional status in persons with low back pain?

The first part of this thesis involves a systematic review of head-to-head comparison studies to determine the difference in the sensitivity to change of the RMQ and the ODI. Five databases were searched and nine articles were located. The second part of this thesis entails the development of a quality criteria form to evaluate head-to-head comparison studies.

The third aspect of this research was to perform a head-to-head comparison study of the RMQ and the ODI using data from the nine studies. A small but significant difference was noted in favour of the RMQ in terms of the Spearman rank correlation coefficient between its change scores and the reference standard (Z = 2.36, p = 0.018; Z = 3.28, p = 0.001) and also in the Receiver Operating Characteristic curve area (X21 = 8.58, p = 0.003).

abstract: Master of Science Rehabilitation Science (MSc)


title: MOTHERHOODS, BODIES AND INEQUALITIES: AN EXPLORATION OF SURROGACY AND ITS IMPLICATIONS FOR SOCIAL WORK

contributor:
Zhou, Rachel
Sinding, Christina
Gladstone, James
Social Work

subject:
surrogacy
motherhood
bodies
Social Work
Social Work

abstract:
Surrogacy is an emerging phenomenon in Canada, facilitated by societal changes and advances in reproductive technologies. Although surrogacy offers individuals an alternative form of family creation, it is rife with issues of inequality and social injustice based on gender, class, age, sexuality and geographical location. These social justice issues are evident in surrogacy discourses, which have influenced public perception on surrogacy and particularly in relation to women and their role as mothers. This exploratory research will examine these discourses and their representations of women and motherhood through a critical discourse analysis combined with a theoretical framework drawing upon post-structural feminist, social constructionist and social justice theories.

Surrogacy discourses have been influenced by patriarchal notions of women and motherhood which evolved during time from focusing on issues of paternity, to women’s rights, to children’s bests interests and finally to family interests. Although the rhetoric surrounding surrogacy has changed, the discourses have always contained oppressive norms concerning women and their bodies. With the rise of global markets and capitalism, these oppressive discourses have taken on global implications for families involved in surrogacy arrangements. These implications beckon the attention of the field of social work on various individual, institutional, structural and global levels through program development, research and advocacy. This research will highlight these implications and will explore recommendations for the social work field in the hopes of providing avenues for social workers to act as agents of social change.

abstract: Master of Social Work (MSW)


title: The role of motor information in learning and behavior in the presence and absence of challenge, physical or cognitive.

contributor:
Lee, Timothy D.
Neuroscience

subject:
motor learning
aging
enactment
balance
alzheimer's disease
Cognitive Neuroscience
Psychology of Movement
Cognitive Neuroscience

abstract: This thesis was specifically designed to explore the role of motor information in behavior and learning in the presence and absence of physical and cognitive challenges. The first experiment examined the role of motor information in the maintenance of standing balance. This study found that light touch (motor information) was most useful when visual condition was challenging, eyes closed. Increased benefit of touch in the presence of challenge suggests that motor information may provide similar information as other senses, and act in a compensatory fashion when those senses are challenged. The second study examined the role of motor information, in the form of enactment, in learning a motor communication task. Results from this study support a role for motor information in enriching the learning environment by strengthening memory to reduce rate of forgetting. The third study examined the role of motor information in disease, using motor-centric instruction and guided movements to teach persons with Alzheimer Dementia to bowl using the Nintendo Wii TM. The spared motor learning observed in these participants confirms claims in the literature of spared motor function in persons with dementia and strengthens the claim the motor system can provide compensatory information to support challenged cognitive systems. Taken together, these findings add to the current literature supporting motor pathways with information separable form other sensory pathways and spared motor capacity to learn in dementia.

abstract: Doctor of Philosophy (PhD)


title: Regulation of macrophage SR-BI by lipoproteins and inflammatory stimuli

contributor:
Trigatti, Bernardo L.
Igdoura, Suleiman A.
Truant, Ray
Biochemistry

subject: Atherosclerosis receptor cholesterol inflammation macrophage lipoprotein

subject: Biochemistry

subject: Biology

subject: Cell Biology

subject: Immunity

subject: Medical Biochemistry

subject: Medical Cell Biology

subject: Medical Molecular Biology

subject: Medical Sciences

subject: Molecular Biology

subject: Biochemistry

abstract: In atherosclerotic plaques, macrophages ingest modified LDL and turn to foam cells. Others have shown that SR-BI expression levels inversely correlated with cellular cholesterol levels, and is independent of well characterized cholesterol sensing pathways; SREBP and LXR. Thus the mechanism of regulation of SR-BI is unclear. In this study, we showed that treating macrophage with agents known to increase cellular cholesterol levels, namely acLDL, LDL, MβCD:Cholesterol, resulted in reduction in HMGCoAR mRNA and SR-BI expression levels. In contrast, acLDL did not reduce SR-BI mRNA levels in macrophages from acLDL SR-A KO mice, demonstrating that acLDL mediate suppression of SR-BI was dependent on SR-A. Fucoidan, a known competitive inhibitor of acLDL binding to SR-A, and subsequent degradation, also suppressed SR-BI expression levels. Unlike acLDL, however, fucoidan induced mRNA levels corresponding to the pro-inflammatory genes iNOS and IL-6 mRNA levels, and its effects were not altered by the lack of SR-A. Instead, fucoidan mediated stimulation of iNOS and IL-6 and suppression of SR-BI mRNA levels was prevented by an anti-CD14 blocking antibody, demonstrating that the fucoidan mediated effects were dependent on CD14. Interleukin-15, a pro-inflammatory cytokine that binds to a distinct receptor, also induced iNOS and IL-6 mRNA levels and reduced SR-BI expression, suggesting that inflammatory signaling in general can reduce SR-BI expression levels. Treatment of macrophages with the lipoproteins acLDL, LDL or HDL suppressed the induction of iNOS and IL-6 mRNA by fucoidan or IL-15. Macrophages foam cells in an atherosclerotic plaque may have reduced SR-BI due to exposure with modified LDL or inflammatory cytokines or both in an atherosclerotic plaque. SR-BI expression in macrophages protects against atherosclerosis development. Our data suggests that modified lipoproteins as well as inflammatory stimuli suppress SR-BI expression in macrophages and this may contribute to their pro-apoptotic properties.

abstract: Master of Science (MSc)


title: A Narrative Study of the Older Patient and Family Caregiver Experience of Alternate Level of Care

contributor:
Ploeg, Jenny
Nursing

subject:
alternate level of care
narrative research
patient and family experiences
uncertainty
information needs
discharge planning
acute care
Geriatric Nursing
Geriatric Nursing

abstract: Alternate Level of Care, or ALC, is a designation assigned to a patient during an acute care hospital stay when that patient is occupying a bed but no longer requires that intensity of service. A high proportion of beds occupied by patients requiring ALC results in problems in the healthcare system related to patient flow, access, and efficiency. The purpose of this study was to better understand the experience of older patients and family caregivers while the patient is designated as requiring ALC. This study employed the Three-Dimensional Narrative Inquiry Space method of Clandinin and Connelly (2000) to examine the experiences of five patients and four family caregivers. The primary data source for this study was a series of semi-structured interviews with individual participants over time while they were in the midst of the experience of ALC. Data analysis involved a twofold process of restorying all interview transcriptions for a given participant into a single story summarizing his or her experience, and analyzing the content across stories to identify common themes. The major finding of this study was that uncertainty was a significant part of the experience of ALC. This uncertainty was manifest in relation to self-concept, waiting for placement, not knowing about information, not being included in planning, lack of mobility, and lack of meaningful activity. The study findings have implications for strategies to manage uncertainty in the areas of practice, policy, education, and research in order to improve the experience of older patients and their family caregivers.

abstract: Master of Science (MSc)


title: “YOUNG CARERS” OF PARENTS WITH MENTAL HEALTH ISSUES

contributor:
Aronson, Jane
Social Work

subject:
young carer
mental health
informal care
mental illness
Social Work
Social Work

abstract:
ABSTRACT

It is estimated that twenty percent of the Canadian population experiences a serious mental illness at some point in their lifetime. A portion of those that do so will be parents. Research indicates that in some circumstances, when a parent with a serious mental illness needs support that they are not getting from other adults or the formal mental health care system, the caregiving responsibilities can fall to their children. Sometimes called “young carers” in literature developed in the U.K. and elsewhere, there has been little attention in Canada to this population or the implications of the term “young carers”. Through a critical feminist lens, a small qualitative study was undertaken to explore the lived experiences of adults looking back on having been “young carers”, a perspective seldom taken in the literature.

The four study participants had all cared for their mothers in households with extended social networks that included fathers and siblings- an interesting counterpoint to the “young carer” literature, which has centered on isolated single parents with children. Participants described how they found themselves in caring roles, what their caring consisted of, and why they continued to care despite other options being available. The study reveals the intricate social pressures that the participants faced, and suggests that becoming a carer may be more complex than past studies have indicated. I examined participants’ stories with an eye to the structural forces that shaped their pathways as carers and their reflections on those pathways. The discussion focuses on what the participants’ experiences can tell us about the contemporary neoliberal political climate: how its emphases on individualism, independence and smaller government, contribute to the depletion of public mental health services and a troubling focus on sustaining “young carers” rather than questioning their positioning.

abstract: Master of Social Work (MSW)


title: THE INFLUENCE OF MACHINE MODEL AND OPTIMIZATION PARAMETERS ON THE GENERATION OF NARROW SEGMENTS IN STEP AND SHOOT INTENSITY MODULATED RADIOTHERAPY PLANS FOR SIMPLIFIED GEOMETRIES

contributor:
Ostapiak, Orest
Diamond, Kevin
Farrell, Tom
Medical Physics

subject:
Step-and-shoot IMRT
Optimization
Treatment planning
Beam penumbra
Medical Biophysics
Medical Biophysics

abstract: Generation of narrow segments is a matter of concern in step-and-shoot intensity modulated radiotherapy for several reasons. The measurement, calculation and delivery of dose from narrow segments may be complicated due to: the dosimetric properties of the detector; the effect of beam penumbra and heterogeneities within the patient; and the requirement for high geometric delivery precision respectively. The main purpose of this thesis was to investigate the parameters affecting the generation of narrow beam segments in IMRT optimization. Parameters such as effective source size, Gaussian height and width, density of the target volume, and gap between the tumor and normal tissue were varied to determine their influence on the number of narrow leaf pair separations. The gradient and penumbra were also examined. Two simple geometric models (thick model and thin model) with different dimensions were used. In the thick model, two 6-MV photon beams were incident on the target at right angles. A rectangular target was centered in a phantom with dimensions 20.25 cm×5.25 cm×20.25 cm. In the thin model, one 6-MV photon beam was normally incident on a 20.25 cm×1.25 cm×20.25 cm slab phantom. The relationship between the penumbra and number of narrow separated leaf pairs were examined for the thick model. The results did not show a consistent pattern. For the thin model, creating a gap between the target and the OAR decreased the total number of narrowly separated leaf pairs along the interface but increased the average dose delivered to the OAR. By varying the OAR max dose or the gap between the target and OAR, a peak was created in the dose profiles to compensate the penumbra. As gradient increased the peak height increased to compensate the dose fall-off. The width of the peak at half maximum changed with gradient but not in a predictable fashion.

abstract: Master of Science (MSc)


title: Fuel and Core Physics Considerations for a Pressure Tube Supercritical Water Cooled Reactor

contributor: Engineering Physics and Nuclear Engineering

subject:
Reactor physics
supercritical water cooled reactor
fuel
Nuclear Engineering
Nuclear Engineering

abstract:
The supercritical water cooled reactor (SCWR) is a Generation IV reactor concept that features light water coolant in a supercritical state. Canada is developing a pressure tube variant of the supercritical water reactor as an evolution of the CANDU reactor. The main advantages of the pressure tube SCWR are an improved thermal efficiency over current reactors, enhanced safety through passive safety features, and plant simplifications. The objective of this thesis was to investigate current fuel and core designs for the Canadian SCWR concept.

Simulations of 2-D lattice cells for fuel assemblies containing 43 and 54 fuel elements were performed using the neutron transport code WIMS-AECL. Safety parameters and fuel burnup performance were investigated here. Three dimensional full core simulations were performed using the diffusion code RFSP. These studies examined batch fueling, cycle length, radial and axial power profiles, linear element ratings, and reduction of axial power peaking through graded enrichment along the fuel channel. Finally, a study of reactivity transients was performed using the FUELPIN heat transfer/point kinetics code.

The main results of the studies show that the coolant density change that occurs as water passes through the pseudocritical point strongly affects fuel performance. It is concluded that the 54 element assembly design is acceptable in terms of coolant void reactivity performance with lattice pitch smaller than 26 cm. To meet the burnup target, a fuel enrichment of about 5% is required. From the RFSP studies, this level of fuel enrichment will provide an operating period of 370 days between refueling. Relatively high axial power peaking is observed at the beginning of cycle conditions. A main finding is that the proposed reactor power level of 2540 MWth produces unacceptably high linear element ratings. This is confirmed using the FUELPIN code. A reduction in linear element rating is suggested for consideration.

abstract: Master of Applied Science (MASc)


title: Design, Modeling and Simulation of Planar Waveguide Time Domain Optical Fourier Transformer

contributor:
Li, Xun
Shiva Kumar, Chih-Hung Chen
Shiva Kumar, Chih-Hung Chen
Electrical and Computer Engineering

subject:
Time Domain Optical Fourier Transformer
Planar Waveguide
Electromagnetics and photonics
Electromagnetics and photonics

abstract: A novel planar waveguide Time Domain Optical Fourier Transformer (TD-OFT), which is composed of waveguide lenses and blazed phase gratings, is proposed. A detailed mathematical derivation based on scalar diffraction optics is presented. In order to verify the theoretical analysis, the reciprocity in TD-OFT is also studied. Three different pulse examples, including the Gaussian pulse, square pulse and square pulse train, are implemented by analytical formulations. To evaluate the device performance, the similarity coefficient is defined. The results show that the similarity increases as the device aperture increases. However, there is trade-off between the similarity and the spectra resolution. For the input pulse, under the circumstance of same similarity, the shorter temporal pulse duration (larger bandwidth) needs smaller aperture size. Improved waveguide lens is particularly designed and then the whole device is simulated by Extension of BPM (EX-BPM) with two specific pulses, Gaussian and raised cosine pulse. The simulation results are also verified by reciprocity theorem using the numerical method. The designed TD-OFT occupies a size about 600μm (in width)×5mm (in length) for an ultrafast pulse around 10fs. It is possible to make the device size even smaller either by reducing the focal length of the collimating lens or enlarging the bandwidth of input pulse. Compared with currently proposed TD-OFT made by discrete photonic and optoelectronic components, this design can be integrated with a more compact size and seems more appealing on the simulated performance and fabrication cost. As a result, the planar waveguide TD-OFT has great potential in the next ultrafast optical network.

abstract: Master of Applied Science (MASc)


title: "Warden" or "Neighbour"? Can Power be Shared in Child Welfare?

contributor:
Schormans, Ann Fudge
Sammon, Sheila
Sinding, Chris
Social Work

subject:
child welfare
community development
power
Foucault
narrative
Social Work
Social Work

abstract:
Child welfare in Ontario has been the object of much scrutiny over the last two decades. The field has experienced a great deal of change as the focus of child welfare shifts to meet the latest political agenda. The mandated role of Children’s Aid Societies has remained constant with child safety at its core and within this role child protection workers wield a great deal of power over families and the community.

At Brant CAS, an alternate to main-stream centralized child protection practice was created to shift to a model that shared the expert role of child welfare with community partners. This model is referred to as an integrated model of community-based child protection. As part of this model, child protection workers and community development programs were relocated to off-site community locations to work collaboratively with families and service providers. TheNew Beginnings Resource Centre is one of these off-site locations where a layering of services is available to families within the community as a means to increasing child safety.

This qualitative research project utilizes the New Beginnings Resource Centre as a case study to examine power constructs that exist in the field of child welfare to gain a better understanding as to whether power may be shared within a community-based model of child protection. Using a window metaphor, this study involves a textual analysis supplemented by additional stories that have come to life through my experiences working at the centre. This research project is grounded in an interpretative critical social work framework drawing from a Foucauldian perspective of power. The complexities of power will be explored as it relates to knowledge, use of self, and the development of relationships within the community. Emphasis is given to reflective practice as a means to deconstruct power. Although the origins of a community-based model are altruistic, there is concern that power may be used as a means of surveillance and social control. The purpose of this study is to gain insight into whether space can be created within community-based child protection to share power. Are we “neighbours” or “wardens”?

abstract: Master of Social Work (MSW)


title: The Development of a Medium Energy Ion Reflection Spectrometer and Some Problems Associated with its Application to Materials Analysis

contributor:
Thompson, D.A.
Electrical Engineering

subject:
Electrical and Electronics
Electrical and Electronics

abstract:
This thesis reports on the development and characteristics of an ion reflection spectrometer designed to operate in the 20 - 150 KeV range with specific application to near surface analysis of solids. The work is divided into two parts.

Part I details the design, operation and calibration of the systems within the spectrometer. They include a high resolution electrostatic analyzer and a premium solid state detector cooled to provide an excellent resolution figure. Control of the spectrometer is via a small minicomputer programmed with machine language in a real-time operating environment. Both energy and geometrical calibration procedures as well as results are provided. Examples are given which illustrate the performance characteristics of the spectrometer. Various corrections to both ESA (eg. neutral component) and solid state detector (eg. pulse height defect) results are determined and applied where necessary.

Part II shows the capabilities of the spectrometer as exhibited during the study of three areas of the medium energy ion-solid interactions. The first is an examination of the large angle scattering cross section behaviour for various incident ions (1 ≤ Z₁ ≤ 10) in gold layers. The results are compared to current theoretical predictions and experimental values. The second is an investigation of the neutralization of charged particles (1 ≤ Z₁ ≤ 10) as they exit from clean gold surfaces. Other experimental values, as well as various theories are discussed in relation to the observed results. The last study includes the determination of the stopping of light mass particles (H,He) in Au films. These values are obtained after the application of several corrections based on methods and results of the previous sections. The stopping powers are related to other experimental results.

From the foregoing investigations, it is concluded that the state of medium energy ion-solid interactions is by no means as quantitative as in the higher energy regime. The energy loss processes and charge neutralization behaviour are not well understood so that there is a great need for reliable and accurate experimental measurements that can provide a solid foundation on which to base a better theoretical model of the processes involved.

abstract: Doctor of Philosophy (PhD)


title: Sex, Contamination and Movement in an Invasive Fish

contributor:
Balshine, Sigal
Psychology

subject:
round goby
Hamilton Harbour
ecotoxicology
behaviour
ecology
reproductive tactics
Zoology
Zoology

abstract: Animal movement has had a long history of study in the fields of behavioural ecology and toxicology, but rarely is the ecological context of behaviour in toxicology directly addressed. To explore how movement might be influenced by both sex differences and habitat contamination, I conducted studies on the round goby, an invasive fish, in a highly polluted part of Lake Ontario. In the first half of my dissertation I examined the reproductive biology of this species, finding evidence of multiple male reproductive tactics, and extended this to predict sex differences in goby movement. I showed that male fish were more exploratory in the laboratory, and over multiple years moved further in the field than females. This difference may predict variation in sex ratio along a round goby invasion front. Second, I accumulated multiple lines of evidence for contaminant exposure in these fish, validating their utility as a contaminant sentinel species in the field. With the same battery of behavioural tests, I revealed that round goby collected from cleaner sites were more exploratory than fish from highly contaminated sites in the laboratory, but moved similar distances in the field. Although changes in activity level are the most frequently used behavioural measure of contaminant exposure, the ecological relevance of change was not apparent in this study. These results challenge the utility of movement as an integrated biomarker of contaminant exposure beyond the laboratory.

abstract: Doctor of Philosophy (PhD)


title: Sedimentary architecture of shallow and deep subsurface Quaternary sediments, southern Ontario

contributor:
Eyles, Carolyn H.
Geography and Earth Sciences

abstract:
Architectural element analysis (AEA) is a tool developed by Allen (1983) and Miall (1985) to describe and understand the internal and external geometry of fluvial sedimentary deposits observed in outcrop, and has been applied to a variety of depositional environments. AEA is a valuable methodology for the detailed reconstruction of sedimentary heterogeneity within stratigraphic units and aquifers/aquitards, which is particularly important in areas strongly reliant on groundwater as a potable source of water such as the Georgetown area in southern Ontario.

This thesis involves a detailed facies and architectural analysis of subsurface Quaternary glacial sediments in the Limehouse and Georgetown area of southern Ontario. A local aggregate pit in Limehouse, Ontario provides several well-exposed outcrop faces primarily composed of coarse-grained sand and gravel deposits (Chapter 2). Architectural elements delineated from the outcrop faces in Limehouse serve as an analogue to deeper subsurface sediments recorded from fully-cored boreholes drilled in the Sixteen Mile Creek area of Georgeotwn, Ontario, which is an area devoid of outcrop exposures (Chapter 3). The Quaternary stratigraphy of the Limehouse and Georgetown area is significantly heterogeneous with a complex architecture recorded in both shallow and deep subsurface sediments (Chapters 2, 3). Aquitard and aquifer/recharge zone layers may be discontinuous and incised/truncated in some places, which may form a hydrologic connection between units and through till sheets (considered to be regional aquitards) to underlying aquifer units (Chapters 2, 3). The geometry and architecture of stratigraphic units can improve the understanding of groundwater flow behaviour, contaminant migration pathways and may enhance the accuracy of local and regional three-dimensional geologic and hydrogeologic models in southern Ontario and for similar glaciated terrains elsewhere.

abstract: Master of Science (MSc)


title: L' ABSURDE ET L' ANGOISSE DANS DEUX PIÈCES DE BECKETT: DÉSIR ET IMPOSSIBILITÉ D'ÉVASION

contributor:
Léger-Lucas, Anna St.
French

subject: French and Francophone Language and Literature

abstract: Dans cette étude, nous examinons deux pièces de Samuel Beckett : En attendant Godot et Fin de partie. A notre avis, ces deux pièces exemplifient l'absurde et l'angoisse inéluctable de la condition humaine. Nous avons choisi comme modèle méthodologique les sept critères proposés par Martin Esslin dans The Theatre of the Absurd pour définir ce qu'il appelle «l'absurde». Notre première partie examine le manque d'intrigue évidente, le manque de développement des personnages et le manque de dialogue pertinent. Ces trois critères distinguent l'absurde dans le monde théâtral de Beckett. Notre deuxième partie applique les quatre derniers critères d'Esslin, exploités afin de faire oublier provisoirement l'angoisse d'une situation impossible mais sans solution. Ce sont: le théâtre pur, la bouffonnerie, le non-sens verbal et l'onirisme. Nous ajoutons à ces quatre techniques celle de la répétition pour compléter la théorie d'Esslin par rapport à Beckett. Ce dernier aspect revient constamment et Beckett l'exploite tout autant que les quatre autres pour révéler que personne n'échappe à la souffrance. L'application du modèle d'Esslin aux deux pièces de Beckett nous pennet de mieux comprendre pourquoi et comment les personnages souffrent. Ils sont constamment pris entre deux pôles: l'espoir et l'impossibilité de mieux, l'espoir et l'impossibilité d'une éventuelle évasion. La tension ainsi créée provoque l'angoisse perpétuelle des personnages qui cherchent sans cesse à échapper à une situation impossible mais qui n'évolue pas. Ce tiraillement constant s'étend aux spectateurs qui espèrent, malgré tout, une résolution heureuse. Enfin, on constate que la complexité de l'univers théâtral de Beckett révèle un monde contradictoire, incertain et sans solution, monde qui nous pousse à y reconnaître le nôtre et à prendre conscience de l'absurdité fondamentale de la condition humaine.

abstract: Master of Arts (MA)


title: An Evaluation of Female Arm Strength Predictions based on Hand Location, Arm Posture and Force Direction

contributor:
Potvin, James
Peter Keir, Jim Lyons
Peter Keir, Jim Lyons
Kinesiology

subject:
arm strength prediction
arm posture
force direction
hand location
3DSSPP evaluation
multi-dimensional exertions
Biomechanics
Biomechanics

abstract: The primary purpose of this thesis was to measure arm strengths, in combinations of exertion directions, and to evaluate the importance of knowing the precise posture of the arm and specific joint locations in 3D space when predicting female arm strength. A stepwise multiple regression approach was utilized in the prediction of female arm strengths, using kinematic measures of hand location, arm posture and 26-force directions from 17 subjects and 8 hand locations as inputs. When including measures of arm posture, the regression model was indeed improved, explaining 75.4% of the variance, with an RMS error of 9.1 N, compared to an explained variance of 67.3% and an RMS error of 10.5 N without those postural variables. A comparison was also made between the empirical strength data from this thesis and the outputs from the University of Michigan’s Center for Ergonomics 3-Dimensional Static Strength Prediction Program (3DSSPP) software. A poor correlation (R-square = 0.305) and high RMS error (39 N) was found, indicating a definite need for further evaluation of the 3DSSPP package, as it is one of the most commonly used ergonomic tools in industry.

abstract: Master of Science (MSc)


title: Predicting epidemiological transitions in infectious disease dynamics: Smallpox in historic London (1664-1930)

contributor:
Earn, D.J.D.
Mathematics and Statistics

subject:
transition analysis
smallpox
SIR model
London Bills of Mortality
Other Applied Mathematics
Other Applied Mathematics

abstract:
Mathematical modelling has become a powerful tool used to predict the spread of infectious diseases in populations. Successful analysis and modeling of historical infectious disease data can explain changes in the pattern of past epidemics and lead to a better understanding of epidemiological processes. The lessons learned can be used to predict future epidemics and help to improve public healthstrategies for control and eradication.

This thesis is focused on the analysis and modelling of smallpox dynamics based on the weekly smallpox mortality records in London, England, 1664-1930. Statistical analysis of these records is presented. A timeline of signiﬁcant historical events related to changes in variolation and vaccination uptake levels and demographics was established. These events were correlated with transitions observed in smallpox dynamics. Seasonality of the smallpox time series was investigated and the contact rate between susceptible and infectious individuals was found to be seasonally forced. Seasonal variations in smallpox transmission and changes in their seasonality over long time scale were estimated. The method of transition analysis, which is used to predict qualitative changes in epidemiological patterns, was used to explain the transitions observed in the smallpox time series. We found that the standard SIR model exhibits dynamics similar to the more realistic Gamma distributed SEIR model if the mean serial interval is chosen the same, so we used the standard SIR model for our analysis. We conclude that transitions observed in the temporal pattern of smallpox dynamics can be explained by the changes in birth, immigration and intervention uptake levels.

abstract: Doctor of Philosophy (PhD)


title: CHAPLIN AMYLOID FIBER FORMATION AND THE ROLE OF THE CHAPLINS IN THE AERIAL DEVELOPMENT OF STREPTOMYCES COELICOLOR

contributor:
Elliot, Marie
Biology

subject:
Streptomyces development
surface ultrastructure
sporulation
functional amyloid
Molecular Biology
Molecular Biology

abstract:
The chaplin proteins are functional amyloids that are produced by filamentous Streptomyces bacteria. The chaplins are essential for the morphological development of S. coelicolor, and are important for altering the surface ultrastructure of aerial hyphae and spores. Although it is well established that the chaplins play an important role in S. coelicolor aerial development, there is still much that remains unknown regarding their activity; in particular, how each of the chaplins contribute to promoting aerial development, and the importance that chaplin amyloidogenesis has in this process.

Previous work has revealed that only three of the eight chaplins (ChpE, ChpC, and ChpH) are necessary for promoting aerial development, and that ChpH plays a significant role in this process. For this reason, ChpH was used as the ‘model chaplin’ to examine the primary sequence determinants governing chaplin amyloidogenesis, and to explore the relationship between ChpH amyloid fiber formation and ChpH-dependent aerial development. This analysis revealed that ChpH contains two amyloidogenic regions, at the N- and C-termini, both of which are necessary for promoting aerial development, while the N-terminal domain is dispensable for surface fiber assembly.

A separate study focused on the role of the short chaplin ChpE. One of the surprising findings of this work is that, unlike the other chaplins, ChpE is essential for maintaining cell viability. The relationship between ChpE cell surface localization and the presence of the long chaplins was also examined. This work showed that the long chaplins are not required for the surface attachment of ChpE (nor the other short chaplins), but do function to enhance the activity of the short chaplins in promoting aerial development, in addition to being necessary for the organization and assembly of surface fibers.

abstract: Doctor of Philosophy (PhD)


title: THE ARTICULATION OF PUBLIC VALUES IN HEALTH TECHNOLOGY ASSESSMENT: THE USE OF DELIBERATIVE DISCOURSE

contributor:
Julia Abelson, PhD
Mita Giacomini, PhD
Andrea Frolic, PhD
Health Research Methodology

subject:
public engagement
deliberative discourse
discourse analysis
health technology assessment
Health Policy
Health Policy

abstract: Objectives: The use of interactive public engagement methods to elicit public values is becoming routine practice in health system planning, policy and evaluation; however, little systematic attention has been given to the analysis of how these values are articulated. This process will be examined with the use of deliberative discourse methods in the context of health technologies. Approach: The deliberations of a 14-person Citizens’ Reference Panel on Health Technologies were audiotaped and transcribed. The panel provided input to the Ontario Health Technology Advisory Committee in developing its recommendations. Discussion transcripts were analyzed using Gee’s (2005) ‘building tasks’ framework with a focus on identities, relationships, and politics. In depth language-context analysis was then used to study ‘situated meanings’ of social and ethical citizen values. Both levels of discourse analysis were then used to elicit the meso-level dynamics within the citizen panel deliberations. Results: Panel members used the provided materials, personal experience and other sources of information to express their values toward the technologies under review. In the group, members used their occupational, personal and cultural identities and adopted in-group citizen panel roles that involved summarizing small group discussions, challenging other members, providing information, providing expertise, interpreting information and facilitating. These individual roles were similar across meetings and members began to form relationships with their fellow citizens and make connections between the values involved in similar technologies. Conclusion: Discourse analysis methods can be used to draw in-depth insights from public engagement deliberations which contribute important new knowledge to the field of public deliberation and health policy. Further use and refinement of deliberative discourse methods will allow public values to be better understood and more adequately portrayed in the health technology assessment process.

abstract: Master of Science (MSc)


title: Regulation of the professional relationship: a case study

contributor:
Schormans, Ann Fudge
Social Work

subject:
Social Work
public policy
critical disability theory
L’Arche
professional relationship
Social Work
Social Work

abstract:
The social inclusion of adults with intellectual and developmental disabilities remains an elusive goal for many adults, their families, and allies. Many of the typical relational human interactions people without intellectual and developmental disabilities enjoy and take for granted, have been denied to adults with intellectual and developmental disabilities, largely because of harmful conceptualizations of what it means to live with a disability. These conceptualizations have not only influenced the development of public policy but they have also shaped the interactions and relationships between professionals and adults with intellectual and developmental disabilities. Equipped with the historical knowledge of how public policy was used to cultivate and maintain the mass institutionalization of adults living with intellectual and developmental disabilities – and then subsequently used to lead to it’s demise – this study set out investigate if and how public policy might influence the nature of professional relationships between service users with intellectual and developmental disabilities and service providers. Using qualitative methods guided by critical disability theory, this study looked specifically at how Ontario Regulation 299/10 has already, and/or may in the future, change the interpersonal relationships that exist between adults living with intellectual and developmental disabilities and their care-givers at L’Arche Hamilton. Research methods included working with the policy document and also conducting face-to-face interviews with adults with intellectual and developmental disabilities and their caregivers. It was important for this study to include the voices of adults with intellectual and developmental disabilities and to examine the research question from their perspective because without their input it would not be possible to really understand the regulation’s impact.

This study focused on the current experiences of three residents (core members) and three care-givers (assistants) at L’Arche. It was found that there exist genuine and caring relationships between the two; relationships shaped by the understanding of the assistants that adults with intellectual and developmental disabilities have something of value – a “gift” – to contribute to what they define as a mutual relationship. In addition, both core members and assistants point to the importance of human touch in care-giving interactions – touch that moves beyond the functional (e.g., assistance with personal care) to also include expressive touch (e.g., hugs) that conveys affection and love. However, the findings further suggest that Ontario Regulation 299/10 threatens the ability of care-givers to engage in the intentional form of relationship which currently exists within the L’Arche service model. This form of relationship is understood to be restricted by the regulation under the guise of “protection” and as being “best practice”. The legislation recognizes that people living with disabilities have higher rates of abuse then those living without disabilities; in response to this reality the legislation attempts to reduce opportunity for such abuses to occur and, as a result, articulates clear boundaries around the type of relationships that are permissible. The assistants interviewed for this study also recognize these concerns but they also worry that these concerns overlook the reality of the limited opportunities for genuine relationships between adults with intellectual and developmental disabilities and those without. Further research, directed by adults with intellectual and developmental disabilities, is needed to unpack how this relationship is understood and experienced by both parties, and how each feels it should be maintained, especially in regards to the use of physical touch as an expression of relationship. Research which engages the core members in dialogue on what “safety” and “relationship” mean and looks like for them is needed in order to truly understand the potential impact limiting the professional relationship may have.

abstract: Master of Social Work (MSW)


title: From Alienation to Integration in Alcoholics Anonymous: A descriptive Analysis Using Dialectical Sociology of Religion

contributor:
Mol, Hans
Sociology

subject: Sociology Sociology Sociology

abstract: This thesis addresses itself toward two interrelated tasks. The first task is to provide an ethnographic description of Alcoholics Anonymous (A.A.), the meetings and the members. The second task is to describe A.A.'s methods using dialectical sociology of religion. Excessive consumption of alcohol provides a variety of social problems and Alcoholics Anonymous has been an increasingly popular solution for those who wish to discontinue their destructive drinking habits. Sociological research on A.A. has, however, been limited; A.A.'s interesting combination of religion and self-help practices has not been combined under one theoretical paradigm. This thesis attempts to respond to that void; to describe A.A.'s effectiveness by combining the social and religious attributes of the program. Alcoholism is conceptualized as a state of alienation, where anomie and normlessness combine with alcohol consumption to present personal and social problems. In Chapter Two, dialectical sociology of religion is outlined as a theoretical model that accounts for the alcoholic's transformation from alienation to integration as an A.A. member. The career model is utilized to organize the data substantiating this theory of transformation, in Chapter Three. Chapters Four to Seven describe the four mechanisms of ritual, objectification, commitment, and myth which facilitate the transformation and Chapter Eight presents a critique of the data, the theory, and the work of this thesis. Alcoholics Anonymous has become one of the most successful self-help groups ever. It has been able to change hopeless human beings into integrated members of society. An organization that can have such a drastic effect on human life warrants further sociological examination.

abstract: Master of Arts (MA)


title: STATIC AND DYNAMIC MODELING OF DNA BIOSENSORS FOR BIOMEDICAL APPLICATIONS

contributor:
Deen, Jamal M.
Ponnambalam Selvaganapathy, Xun Li
Ponnambalam Selvaganapathy, Xun Li
Electrical and Computer Engineering

subject: biosensor

subject: model

subject: DNA

subject: simulation

subject: finite-element

subject: lab-on-chip

subject: Biochemical and Biomolecular Engineering

subject: Biomedical devices and instrumentation

subject: Biophysics

subject: Biotechnology

subject: Nanoscience and Nanotechnology

subject: Other Electrical and Computer Engineering

abstract:
Achieving control over the construction and operation of microfabricated label-free DNA biosensors would be a big leap in the quest for highly reliable clinical laboratory tests. Reliable outcomes of critical medical tests mean less need for repetitions and earlier isolation of outbreaks. Nanotechnology has lent itself well to this purpose, with a plethora of work that attempt to produce highly sensitive nano-biosensors for detection of DNA strands. The problem of achieving a repeatable outcome is crude at best. Additionally, the mechanism of sensing in label-free Field-Effect based DNA sensors is still a matter of dispute. Simulation of the sensors using physical models can shed light into these mechanisms and help answer this question. Computational calculations can also allow designers to assess the importance of several parameters involved in the fabrication.

In this thesis, the problem of modeling FET-based DNA hybridization sensors (named BioFET) is approached. Using the Finite-Element Method, a scalable model for the BioFET is produced and solved in 3D. The results are compared to an earlier work and we find that higher dimension physical modeling is essential for more realistic results. Additionally, we present a model for the impedance of the BioFET which allows the calculation of parasitic components that can contaminate the impedance measurements.

The issue of variations in the sensed signal from the BioFET is addressed by performing hybrid Finite-Element/Monte Carlo simulations on the conformation of single-stranded DNA. From electrostatic considerations alone, it is concluded that the change of conformation upon hybridization is a main contributor to the induced signal. We also simulate the positional variations of the DNA molecules on the sensitive surface. This computation yields an estimate for the amount of variation in the sensed signal due to the random placement of DNA molecules, and an estimate for the total signal-to-noise ratio is deduced.

abstract: Doctor of Philosophy (PhD)


title: Topological and Quantum Mechanical Study of Molecular Charge Distributions

contributor:
Bader, Richard F. W.
Chemistry

subject: Chemistry Chemistry

abstract:
This thesis is concerned with the rigorous definitions of the two central concepts embodied in the notion of molecular structure, namely, the concepts of atoms and bonds. The basis for the present approach is provided by the topological properties of the charge distribution in a given molecular system. The essential observation is that the only local maxima of a ground state distribution occur at the positions of the nuclei. The nuclei are, therefore, identified as point attractors of the gradient vector field of the charge density. The associated basins partition the molecule into atomic fragments. Each atom is a stable structural unit defined as the union of an attractor and its basin. The common boundary of two neighbouring atomic fragments, the interatomic surface, contains a particular critical point, which generates a pair of gradient paths linking the two neighbouring attractors. The union of this pair of gradient paths and their endpoints is called a bond path. The network of bond paths defines a molecular graph of the system.

Having defined a unique molecular graph for any molecular geometry, the total configuration space is partitioned into a finite number of regions. Each region is associated with a particular structure defined as an equivalence class of molecular graphs. A chemical reaction in which chemical bonds are broken and/or formed is, therefore, a trajectory in configuration space which must cross one of the boundaries between two neighbouring structural regions. These boundaries form the catastrophe set of the system which, like a phase diagram in thermodynamics, denotes the points of "balance" between neighbouring structures. A general analysis of the structural changes in an ABC type system is given in detail, together with specific examples of all possible structural elements in a molecular system.

The topological definition of an atom as the union of a nuclear attractor and its basin is equivalent to its definition in terms of its boundary. An atomic boundary consists of the union of a number of surfaces through which the flux of the gradient vector of the charge density is zero. Such a surface is called a zero-flux surface. In general, the zero-flux surfaces define subsystems of a molecular system which represent atomic fragments or functional groupings of such fragments. The properties of these subsystems are delineated through a variational approach to the quantum mechanics of molecular subsystems. In both the time-dependent and the stationary state case, the variational equations for a subsystem are generalizations of the corresponding expressions for a total system. The stationary-state variational principle relates the first-order change in the subsystem energy functional to the flux, through the boundary of the subsystem, of the current density generated by an infinitesimal arbitrary variation in the state function. From this principle, the generalizations of the important hypervirial and virial theorems are obtained, which apply equally to a subsystem as to the total system. In particular, a definition of the subsystem energy, which exhibits the important additivity property, is obtained through the subsystem virial theorem. The time-dependent variational equations generalize the stationary state variational principle; they are shown to follow from Schwinger's quantum action principle and principle of stationary action. The application of these principles to a subsystem requires that the subsystem quantum action integral be stationary in the sense that its first variation, ensuing from arbitrary variations in the state function between two given time endpoints, contains only contributions from these time end-points and from the spatial boundary of the subsystem, at intermediate times. When the aforementioned variations are produced by an infinitesimal unitary transformation, the subsystem variational principle relates that change in the subsystem Lagrangian to the commutator of the generator of the transformation with the Hamiltonian of the system. From this statement of the time-dependent variational principle, a force law is obtained, which generalizes Ehrenfest's theorem, and can be regarded as the quantum analogue of Newton's equation of motion. The variational principle also leads to a generalization of the continuity equation, which governs the time change of an atomic population, and an extension of the virial theorem to describe a subsystem - an atom, or a functional grouping of atoms - in a time-dependent molecular environment.

abstract: Doctor of Philosophy (PhD)


title: Beneath and Beyond the Surfaces: The Road to A Wild Old Man on The Road

contributor:
Rosenblood, N.
English

subject:
English Language and Literature
English Language and Literature

abstract: The psychological themes of innocence, guilt, and betrayal are central to much of Morley Callaghan's works. As Patricia Morley indicates in her article, "Innocence Betrayal and Betraying," there is a significant difference in the treatment of innocence between Callaghan's novels of the thirties and his postwar work. Using the psychoanalytic model of criticism, this thematic development is examined from Callaghan's thirties period to his last novel, A Wild Old Man on the Road (1988). Having established the psychodynamics within both representative novels from several phases in Callaghan's career, as well as the evolving pattern throughout, this analysis reveals a significant correlation between the psychological conflicts within each novel and period, and as they evolve thematically, the various dynamic points within the Oedipus Complex, as described by Sigmund Freud. Callaghan's protagonists feature an inherent Oedipal fixation: they attempt, to varying degrees, yet are unable to attain, Oedipal resolution.

abstract: Master of Arts (MA)


title: Reading and Writing Emily Carr

contributor:
Adamson, Joseph
English

abstract: Emily Carr is a critically neglected figure in Canadian literature. Our current perception of her is defined almost totally by biographies and myth. This thesis attempts to demonstrate the sorts of strategies of truth which permeate the discourses of biography and autobiography. I confront the question of identity by examining how Emily Carr's writing about herself differs from that of her biographers. Where does the self that is allegedly carried by and through language find itself to be? Writing is treated as a representational medium; the page is the canvas painted by the grapheme. While I believe that we cannot avoid defining Carr in traditional terms of family, society, geography etc., I hope that this thesis provides an alternate reading of familiar concepts. I wish to represent Emily Carr as a Western writer but one with a "difference."

abstract: Master of Arts (MA)


title: Time-to-Collision of Looming Spherical Objects: Tau Revisited

contributor:
Sun, Hong-jin
Bennett, Patrick J.
Maurer, Daphne M.
Psychology

subject:
tau
time-to-collision
motion-in-depth
perception
ecological psychology
optic flow
Cognition and Perception
Cognition and Perception

abstract:
As an object approaches an observer’s eye, tau, defined as the inverse relative expansion rate of the object’s image on the retina (Lee, 1976) approximates time-to-collision (TTC). Many studies have suggested that human observers use TTC information, but evidence for the use of tau remains inconclusive. Here we present two studies that investigated the use of tau in object-motion and observer-motion situations. In Study I, we dissociated several monocular variables that potentially contributed to TTC perception, and found that participants were most sensitive to TTC information when performing a relative TTC estimation task; and less sensitive to non-time variables such as distance-to-collision, speed and object size. Additionally, when we manipulated sources of information to specify conflicting time-of-arrivals, TTC specified by tau was weighted more than TTC derived from distance and speed. Thus, we concluded that even in the presence of monocular depth information, observers strongly utilize tau when estimating TTC.

In Study II, observers estimated TTC of a looming target in the presence or absence of background expansion. Results demonstrated that participants overestimated TTC in situations where the surroundings of the target’s contours expanded at a reduced rate. Moreover, simulated self-motion was unnecessary to induce this bias, as results were comparable in situations where this relative expansion was limited to the target’s immediate surroundings. Therefore, we also concluded that a relative tau variable, based on the relative rate of expansion, is utilized whenever expansion beyond the object’s immediate boundaries is less than the target’s absolute rate of expansion.

abstract: Master of Science (MSc)


title: Synthesis, Characterization and Evaluation of Central Nervous System Targeted Metallocarborane Complexes

contributor:
Valliant, John F.
Chemistry

subject:
organometallic
carborane
rhenium
technetium
radiochemistry
click chemistry
Inorganic Chemistry
Inorganic Chemistry

abstract:
A series of new methodologies to link a neurotransmitter receptor targeting vector (WAY) to carboranes and the preparation of the corresponding metallocarboranes (M = Re, 99mTc) as a new class of organometallic CNS imaging probes is described. WAY-carboranes (5, 6, 16) and the corresponding metallocarboranes (M = Re (12, 13, 22a, 22b), 99mTc (14a, 15, 23)) were synthesized in yields ranging from 10-95%. The first observed 3,1,2 versus 2,1,8 rhenacarborane isomerization process was discovered for 12 where isomerization and complexation occurred simultaneously. Re-carboranes 22a and 22b had similar carbon-carbon cage configuration where electronic effects was the driving force behind isomerization.

The lipophilicities of 99mTc-carboranes (14a, 15, 23) were within the ideal range to cross the BBB (log P = 2.4-2.6). In vitro binding data showed that 22b has high affinity for alpha-adrenergic receptors (Ki = 17-39 nM) resulting in the first organometallic complex to effectively bind to this class of receptors. SPECT images of 14a in rats showed no brain uptake, while quantitative biodistribution studies indicated modest, non-negligible brain uptake in the hypothalamus region.

The neutral [M(CO)2(NO)(C2B9H10R)] analogues (30, 34, 37) were prepared to address the limited brain uptake of the [M(CO)3(C2B9H10R)]- complexes. Reactivity differences between Re and 99mTc were noted during nitrosation conditions where the initial products from the reaction led to nitration of the phenyl group in addition to nitrosation of the metal core. The fluorescence properties of 29 were measured.

Low yields and multistep syntheses associated with the preparation of substituted carborane led to the development of a carborane-alkyne platform. Alkyne-carboranes (53-55) were developed and conjugated to WAY-azide (46) using “click” chemistry. The metallocarboranes (M = Re (69-71), 99mTc (72-74)) were generated in yields ranging from 45-71%.

abstract: Doctor of Philosophy (PhD)


title: ASPECTS OF CHRISTIAN RELIGIOUS EXCLUSIVITY AND THE “CHRISTIANISATION” OF THE PAGAN IDENTITY

contributor:
Haley, Evan
Eilers, Claude
Beckmann, Martin
Classical Studies

subject: Christianity

subject: Paganism

subject: Roman

subject: Empire

subject: Religion

subject: Church

subject: Ancient History, Greek and Roman through Late Antiquity

abstract: Scholarship dealing with the phenomenon of Christianisation in the Roman Empire has overwhelmingly been Christian-centred, often ignoring the importance of the declining pagan communities in the fourth century A.D. During this period of cultural and religious transformation in the Empire, the construction of religious identity by the Church resulted in the need for pagan communities to adapt themselves to a Judeo-Christian understanding of religion, in order to establish their place in an increasingly Christianizing society. Consequently, the isolation of pagans from, and their vilification within, the growing Christian world were factors that had aided the development of a pagan socio-religious identity which had not existed in previous centuries. Therefore, this paper will examine the question of what elements constituted the pagan identity in late antiquity, and, perhaps more importantly, how this identity had come to be formed.

abstract: Master of Arts (MA)


title: The Effect of Compacted Graphite Iron Microstructure on Fracture and Machining

contributor:
Aziz, Mohamed Abdel
Ng, Eu-gene
Veldhuis, Stephen
Mechanical Engineering

subject:
Compacted graphite
finite element
modeling
machining
Applied Mechanics
Computer-Aided Engineering and Design
Manufacturing
Numerical Analysis and Computation
Other Mechanical Engineering
Applied Mechanics

abstract:
The graphite structure in compacted graphite iron (CGI) is more coral-like and interconnected only within each eutectic cell. The irregular surface of the graphite-matrix interface has blunt edges which results in the intimate adhesion of the graphite particles to the metal matrix producing more resistance to crack initiation and more vermicular paths arrest crack propagation. Furthermore, the coral-like graphite particles, which are characterized with round edges, also do not promote crack propagation and serve as crack arrestors once cracks are initiated. This unique morphology of graphite in CGI, thereafter, pays off in a higher tensile strength and modulus of elasticity while possessing reasonable thermal conductivity.

This work is divided into two phases. The first phase establishes a foundation of a microstructure modeling technique which will be then applied to model CGI in machining. Modeling is being done to shift the approach away from trial and error as is currently being done to a more physics based approach. As machining is conceptually a controlled fracture process, this stage comprehensively studies and models the initiation and propagation of fracture in compacted graphite iron.

The second phase serves as an application of the previously built model to capture the more complex scenario involving machining of CGI at different cutting speeds and feeds. The finite element modeling of CGI in machining provides an as of yet unavailable procedure on which future optimization techniques can be performed. The study of chip formation, cutting insert wear, and force measurements are performed in parallel with the modeling process and are employed as means to validate the FE model. Validation of both work phases has been completed to support the model developed in this thesis that captures the critical aspects of machining CGI under different operating scenarios.

abstract: Doctor of Philosophy (PhD)


title: Seeing Differently in Near and Far

contributor: Daniel Goldreich, Jim Lyons, Scott Watter

subject:
Peripersonal/extrapersonal space
isoluminance
detection
identification
visual pathways.
Cognition and Perception
Cognition and Perception

abstract:
Based on evidence from studies involving animal single cell recording, animal brain lesion, and human brain damage, researchers have suggested that there may be differential visual representations for objects in near (peripersonal, within arm’s reach) and far (extrapersonal, beyond arm’s reach) space in the human visual system. The findings in Chapter 2 and Chapter 3 of the present thesis provide the first behavioural evidence suggesting that healthy human observers prefer to rely on different visual mechanisms in processing information in near and far spaces. The different performance in detecting visual targets presented in near and far space indicates that the brain can actively modulate the information processing either in parvocellular and magnocellular pathways or in ventral and dorsal streams.
 To determine the loci of the neural modulation regarding near and far viewing, visual identification tasks were employed in Chapter 4. In four experiments, visual stimuli were presented in either isoluminant green or achromatic white in order to decouple the neural processing in parvocellular and magnocellular pathways. The different patterns of the visual performance in the four experiments suggest that the change to near or far viewing distance results in altered information transmission in parvocellular and magnocellular pathways. Thus, the data in the present thesis provide the first behavioural evidence indicating that the LGN serves as a gatekeeper for regulating and redistributing visual information for later cortical analysis.

abstract: Doctor of Science  (PhD)


title: The utilization of activated B cell for cell carrier for viral vectored antigen delivery in the acceleration of CD8 T cell recall response

contributor: Medical Sciences (Molecular Virology and Immunology Program)

subject:
cancer immunotherapy
cellular immunity
viral antigen delivery
Medical Immunology
Medical Immunology

abstract: Cancer vaccine therapy aims at harnessing effective antigen specific immune responses to treat tumor. In particular, CD8+ T cells have the unique capacity to recognize and destroy tumor cell throughout the body. One potential approach to elicit high numbers of effector CD8+ T cells to control tumor growth is through repeated vaccination, a strategy called prime-boost vaccination. However, booster immunization is relatively inefficient during primary immune response because pre-activated effector T cells tend to impair robust antigen presentation. This phenomenon has been interpreted as a negative feedback mechanism where recently activated CD8+ T cells clear the antigen-bearing dendritic cells (DCs) and prevent memory T cells from the access of the boosting antigen. Interestingly, however, using in vitro activated B cell as a viral vector delivery system, we can boost T cell responses with the minimum viral input at a very short interval between immunizations. This B cell carrier is capable of delivering different viral vectors expressing different antigens, displaying a potential for broad application. The mechanisms behind B cell carrier-mediated efficient secondary responses are three fold: 1. Without the engagement of MHC molecules and antigen presentation, B cell carrying viral vector can bypass the killing by pre-existing effector T cells 2. B cells can delivery viruses to B cell follicles, a place separated from effector T cells, and mediate memory T cell expansion. 3. B cells can deliver antigen to both spleen and lymph node and induce antigen specific T cell expansion in multiple lymphoid organs. Our studies provide a novel boosting platform to accelerate CTL responses that has important clinical implications.

abstract: Master of Science (MSc)


title: Study of Liquid-Liquid Dispersion of High Viscosity Fluids in SMX Static Mixer in the Laminar Regime

contributor:
Hrymak, Andrew N.
Baird, Malcolm H.I.
Thompson, Michael R.
Chemical Engineering

subject:
SMX
static mixers
Hough transform
liquid-liquid dispersion
Catalysis and Reaction Engineering
Complex Fluids
Other Chemical Engineering
Polymer Science
Robotics
Catalysis and Reaction Engineering

abstract:
In this research, liquid-liquid dispersion of viscous fluids was studied in an SMX static mixer in the laminar regime. Backlighting technique was used for flow visualization, and the Hough transform for circle detection was used in OpenCV to automatically detect and measure drop diameters for obtaining the size distribution. Silicone oil and an aqueous solution of high fructose corn syrup were used for dispersed and continuous phases respectively, and sodium dodecyl sulfate was used as the surfactant to modify the interfacial tension. Experiments were conducted at varying viscosity ratios and flow rates-each at zero, low (~200 ppm) and high (~1000 ppm) surfactant concentrations. The effect of holdup was explored only for a few cases, but it was found to have a minimal effect on the weighted average diameter D43.

It was found that the superficial velocity and the continuous phase viscosity had a dominant effect on D43. The tail at the higher end of the droplet size distribution decreased with increasing superficial velocity and continuous phase viscosities. It was also found that D43 decreased with lowering of the interfacial tension. Furthermore, the effect of the dispersed phase viscosity was significant only at non zero surfactant concentrations.

An approximate model has been proposed that relates D43 to the capillary number. It is based on an energy analysis of the work done by the viscous and surface forces on a drop of an initial diameter that is largely determined by the gap distance between the cross bars in the element

abstract: Master of Applied Science (MASc)


title: AN INVESTIGATION OF SPATIAL REFERENCE FRAMES AND THE CHARACTERISTICS OF BODY-BASED INFORMATION FOR SPATIAL UPDATING

contributor:
Sun, Hong-Jin
Sue Becker and David Shore
Sue Becker and David Shore
Psychology

subject:
spatial reference frames
spatial updating
facilitative effect of locomotion
scene recognition
Cognitive Psychology
Other Psychology
Cognitive Psychology

abstract: Successful navigation requires an accurate mental spatial representation of the environment that can be updated during movement. Experiments with animals and humans have demonstrated the existence of two forms of spatial representation: egocentric (observer-centered) and allocentric (environment-centered). Unfortunately, specifically how humans use these two systems is not well understood. The current dissertation was focused on providing evidence differentiating human use of egocentric and allocentric spatial reference frames, specifically examining the characteristics and contributions from body-based sources. Two empirical chapters are presented that include experiments involving two common spatial tasks. In Chapter 2, updating of feature relations within a room-sized environment was examined by having observers provide directional judgments to learned features with respect to an imagined orientation that was either congruent or incongruent with their physical orientation. The information available for updating the physical orientation was manipulated across experiments. Performance differences between congruent and incongruent conditions demonstrated the reliance on egocentric representations for updating, and differentiated body- and knowledge-based components of the egocentric updating process. The specificity of the body-based component was examined in Chapter 3 by having observers detect changes made to a tabletop spatial scene following a viewpoint shift resulting from their movement, scene rotation or both. The relation between the extent of observer movement and the magnitude of the experienced viewpoint shift was manipulated. Change detection performance was best when the extent of observer movement most closely matched the viewpoint shift, and declined as the match declined. Thus, body-based cues contributed specific information for updating self-to-feature relations that facilitated scene recognition. Throughout the course of the research program it has become clear that humans rely on egocentric representations to complete these tasks, and sensory and motor modalities involved in self-motion are integrated for updating spatial relations of novel environments.

abstract: Doctor of Philosophy (PhD)


title: Discrete Atomic Simulation of Fracture in Iron

contributor:
Dokainish, M. A.
Mechanical Engineering

subject:
Mechanical Engineering
Mechanical Engineering

abstract:
The thesis is concerned with improving the understanding of materials at the atomic level by computer simulation. The work has centered on three areas: a study of the efficiency of various computer algorithms used to carry out these simulations; the development of a new and very versatile boundary condition scheme for such problems; and the application of the results of these two studies to the simulation of (001) plane fracture in α-iron.

Tests were performed comparing various solution methods used for atomic level computer modelling. The results are presented and indicate the most efficient method to be chosen for various problems. This may allow a reduction in computer cost by factors of two or three over that of other, often used, methods.

The new boundary scheme which was developed involves the use of the finite element method. This offers several advantages over previous methods.

The new boundary scheme was applied to the (001) plane crack in α-iron. Two dimensional cracks with crack line directions of [010] and [110] were modelled. Significant differences in lattice trapping limits and crack propagation speeds were observed between these two cases. Information on the magnitude and shape of the non-linear component of the crack tip displacement field is provided for both cases. No dislocations were emitted at low temperatures from these models, but warming the [010] model to 400 K apparently resulted in the emission of a dislocation from the crack tip. Experimental information available in the literature pertaining to these points is discussed and possible future work is described.

abstract: Doctor of Philosophy (PhD)


title: SMOOTH VARIABLE STRUCTURE FILTERING: THEORY AND APPLICATIONS

contributor:
Habibi, Saeid R.
Mechanical Engineering

subject:
estimation
filtering
variable structure
kalman
controls
mechatronics
Mechanical Engineering
Mechanical Engineering

abstract:
Filtering strategies play an important role in estimation theory, and are used to extract knowledge of the true states typically from noisy measurements or observations made of the system. The name ‘filter’ is appropriate since it removes unwanted noise from the signal. In 2007, the smooth variable structure filter (SVSF) was introduced. This filter is based on the sliding mode control and estimation techniques, and is formulated in a predictor-corrector fashion. The SVSF makes use of an existence subspace and of a smoothing boundary layer to keep the estimates bounded within a region of the true state trajectory. This creates a robust and stable estimation strategy. The research presented in this thesis focuses on advancing the development and implementation of the SVSF.

In its original form, the SVSF does not utilize a state error covariance matrix, which is a measure of the accuracy of the state estimates. Therefore, the first major contribution of this research is the formulation of an SVSF strategy with a covariance derivation. This creates a number of research opportunities that can only be pursued and rely on the availability of the error covariance matrix. In an effort to further improve the estimation accuracy, a time-varying smoothing boundary layer is created by minimizing the covariance. This contribution significantly improves the SVSF, and provides a mechanism for combining the SVSF with other popular estimation strategies. A linear system example with the presence of uncertainties is studied which demonstrates that the proposed SVSF improves the estimation accuracy by approximately 20%. Furthermore, a new model-based fault detection strategy is created based on the interacting multiple model (IMM) method. This new method (IMM-SVSF) is applied on an experimental apparatus for the purposes of fault detection. It is able to improve upon the fault detection probability by 10-30% (depending on the fault), when compared with the most commonly used strategy. The IMM-SVSF method is also found to work extremely well for target tracking problems, demonstrating an improvement of roughly 40%. This research results in a number of novel contributions, and significantly advances the development of the SVSF.

abstract: Doctor of Philosophy (PhD)


title: Transitioning to Critical Care: An Exploration of the New Graduate Registered Nurse Experience

contributor:
Baxter, Pamela E.
Jenny Ploeg, Charlotte Noesgaard
Jenny Ploeg, Charlotte Noesgaard
Nursing

subject:
new graduate nurse
critical care
graduate nurse
Critical Care Nursing
Critical Care Nursing

abstract:
With the increasing demand on the health-care system and increasing human resource shortages, the delivery of critical care services is facing a crisis. Although funding is being provided to increase the number of critical care beds to meet the physical demands, the supply of qualified registered nurses (RNs) is decreasing. To increase the required staff, new graduate RNs are being hired into critical care units more than ever before. The influx of newly graduated RNs has been deemed controversial as it is viewed that new graduates are unable to engage in complex decision-making or complete the technical skills required in critical care.

The research objective of this study was to explore the experiences of new graduate RNs entering a critical care unit and to gain an understanding of the barriers and facilitators present when transitioning to the unit. Semi-structured interviews with eleven participants were conducted with new graduates from four critical care units within two major teaching hospitals in Southwestern Ontario. A qualitative descriptive design described by Sandelowski (2000) was used for this research study. The findings describe the experiences of new graduates including the emotional experience, the times of transition, becoming a professional, embracing team support and learning to feel comfortable within the unit.

These findings will be of interest to a broad audience including nursing students, new graduates, hospital managers and administrators, educators and policy makers. It is anticipated that these results will help inform organizational policy and programs and will direct further research on this topic.

abstract: Master of Science (MSc)


title: Increased hospitalization for hemorrhages in patients taking amiodarone with warfarin: a population-based cohort study

contributor: Clive Kearon, Eleanor Pullenayegum, Fred Spencer

contributor: Clinical Health Sciences (Health Research Methodology)

subject:
drug interaction
amiodarone
warfarin
hemorrhage
bleed
administrative database
Medicine and Health Sciences
Medicine and Health Sciences

abstract:
BACKGROUND

Amiodarone is believed to inhibit the hepatic metabolism of warfarin, potentiating its hypoprothrombinemic effect and increasing the risk of hemorrhage. The consequences of this drug interaction on important clinical outcomes are unknown.

METHODOLOGY

Using linked health administrative databases, we conducted a population-based retrospective cohort study among Ontario residents aged 66 years or older who had been treated with warfarin therapy for at least 6 months. Within this group, we identified subjects who initiated amiodarone while on warfarin. Each of these subjects was matched to a subject not treated with amiodarone on age, sex, year of cohort entry, and a high dimensional propensity score. The primary outcome was a hospitalization due to a hemorrhagic event within 30 days of follow-up. In a secondary analysis, we examined in-hospital mortality following hospitalization for major hemorrhage.

RESULTS

We identified 60,497 eligible patients between July 1, 1994 and March 31, 2009. Of these, 11,665 (19.3%) received a new prescription for amiodarone while receiving ongoing warfarin therapy and 7,124 (61.1%) of these were matched to a subject who was not exposed to amiodarone while receiving warfarin therapy. The median age at cohort entry of the matched cohort was 76 years, 51.6% in the cohort were male, 14.5% lived in a rural location, 2.8% had a bleed in the past year, and 21.6% had a diagnosis of congestive heart failure in the past year. Fifty-six amiodarone recipients experienced a hemorrhagic event (0.8%) as compared to 23 individuals (0.3%) in the non-exposed group at 30 day follow-up (adjusted hazard ratio (HR) = 2.45; 95% CI, 1.49 to 4.02). Seven patients in the amiodarone group died after hospitalization for a hemorrhage versus four in the non-exposed group (adjusted HR = 1.74; 95% CI, 0.25 to 12.24).

CONCLUSION

Initiation of amiodarone in patients on chronic warfarin therapy was associated with a two-fold increase in the risk of hospitalization due to a hemorrhagic event. Physicians should closely monitor the response to warfarin following initiation of amiodarone.

abstract: Master of Science (MSc)


title: THE PERCEPTUAL COMPLETION PROCESS: EVIDENCE FROM 8-YEAR-OLDS, 11-YEAR-OLDS, AND ADULTS

contributor: Daniel Goldreich, Ph.D., Allison Sekuler, Ph.D.

subject: object completion

subject: development of the perceptual completion process

subject: quasi-regular occluded object

subject: time course of completion

subject: amodal completion

subject: global and local processing

subject: Developmental Psychology

subject: Developmental Psychology

abstract: Three main theories have been proposed to account for the completion of occluded objects, namely local theories (e.g., Kellman & Shipley, 1991), global theories (e.g., Boselie & Leeuwenberg, 1986), and integrative models of completion (e.g., Sekuler, 1994; van Lier et al., 1994). Here, we investigated age-related changes in the completion of a complex partially occluded object using a prime-matching task. Subjects were shown a prime (global, local, occluded, or no prime) that was followed immediately by two shapes that were judged as being the same or different. In Experiment 1, we tested adults (n = 36/group) at various prime durations (150 - 700 msec) to tap into earlier and later representations of the occluded object. Although the occluded object primed both the global and local shapes at 150 and 500 msec (ps<0.05), only the global shapes were primed at 300 and 700 msec (ps<0.05). Overall, our results are most consistent with integrative models of completion. In Experiment 2, we tested 8-year-olds (n = 20) at a prime duration of 700 msec and 11-year-olds (n = 30/group) at a prime duration of 300 or 700 msec. For 11-year-olds, unlike adults, the occluded object did not significantly prime either the global or local shapes at 300 msec (p>0.50). For both 8- and 11-year-olds, the global, local, and occluded primes did not significantly prime either shape at 700 msec (ps>0.50). Based on the current testing conditions, we found that the perceptual completion process may not be adult-like even at 11 years of age.

abstract: Master of Science (MSc)


title: LABOUR MARKET PERCEPTIONS OF CARIBBEAN INTERNATIONAL STUDENTS AND THE FACTORS THAT INFLUENCE THEIR DECISIONS OF WHETHER TO REMAIN IN CANADA TO WORK OR TO RETURN HOME

contributor:
Mills, Suzanne
Baines, Donna
Lewchuk, Wayne
Work and Society

subject:
Caribbean international students
perceptions
international mobility
brain drain
labour market
caribbean immigrants
Other International and Area Studies
Other International and Area Studies

abstract: Many Caribbean international students travel to Canada to complete their post-secondary education. Upon graduation, these students often remain in Canada to work as opposed to returning home. This study identifies the factors that influenced Caribbean international students’ decisions of whether to remain in Canada or to return home and evaluates the relative importance of their labour market perceptions in light of all of the factors influencing their decisions. Factors such as easy labour market entry, high wages, less stringent immigration policies, careers relevant to the students’ degrees, family ties and relationships with loved ones, discrimination in the labour market, lifestyle and attitudes of governing bodies and prominent community members can all act as push or pull factors in Canada, the host country, or the students’ countries of origin. These factors influence the students’ decisions of whether they should remain in Canada to work or return home. However, results support the conclusion that labour market perceptions are the most significant factors in students’ decision making.

abstract: Master of Arts (MA)