title: Recovery of modifiable risk factors at four years following distal radius fracture and their role as predictors of bone mineral density, subsequent falls and osteoporotic fractures

contributor:
MacDermid, Joy
Grewal, Ruby
Beattie, Karen
Rehabilitation Science

subject: distal radius fracture, falls, osteoporosis, prevention, bone health

abstract:
Distal radius fracture (DRF) is one of the most common fall-related osteoporotic (OP) fracture
and is an early predictor of subsequent falls and OP fractures among people with DRF. The
majority of older people with DRF present with low bone mineral density (BMD) and there is
often transition to reduced muscle strength, poor balance, fear of falling and physically inactive
lifestyle after fall-related DRF. This thesis consists of three manuscripts which are aimed to
explore the recovery patterns and the role of modifiable risk factors in predicting subsequent
falls, OP fractures and BMD in patients with DRF.
The first manuscript explores the recovery patterns in modifiable risk factors for falls and OP
fractures over four years in patients with DRF. Our study findings showed that patients with
DRF experienced both short-term (6 months) and long-term (4 years) improvement in fracture specific
pain/disability, physical activity, fear of falling, BMD and general health status;
although the majority of the recovery was achieved at six months after DRF.
The second manuscript is a cross-sectional study identifying modifiable risk factors for BMD in
patients with DRF. The unaffected hand grip strength was identified as the independent predictor
of BMD explaining 17% and 12% of total variability in the BMD-femoral neck and BMD-total
hip, respectively. Among age-stratified women with DRF, balance and unaffected hand grip
strength were identified as independent determinants of BMD explaining 10% and 32% of the
total variability in BMD-femoral neck among 50-64 year and 65-80 year old, respectively.
The third manuscript is a longitudinal study identifying modifiable risk factors for subsequent
falls and OP fractures at four years after DRF. The results suggest that nearly 24% of patients
reported one or more subsequent falls (in the last six months) and 19% of patients experienced at
least one subsequent OP fracture after DRF. Patients with poor balance, low BMD, fracture specific
pain/disability of >81 points on patient-rated wrist evaluation questionnaire and presence
of a prior history of multiple falls (≥2) had three times higher odds of subsequent falls. When
adjusted for BMD, age and gender, only prior falls was identified as a significant independent
predictor of subsequent falls. We were not fully powered to explore association of various
modifiable and non-modifiable risk factors with subsequent fractures. However, we found that
patients with osteopenia or osteoporosis had clinically four times higher odds of subsequent OP
fractures than patients with normal BMD.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract: Wrist fractures are the most common fall-related fragility fractures and often an early indicator of future falls and fractures. This thesis project described recovery patterns in various risk-factors at 4-years after wrist fracture and explored their association with bone mineral density (BMD) and subsequent falls and fractures. We found that the majority of recovery in fracture-specific pain/disability, fear of falling and health-status takes place within six months, although small changes were also noted between 6 months-4 years. People with low unaffected hand grip-strength might have low BMD. Furthermore, people with poor balance, greater fracture-specific pain/disability, osteopenia or osteoporosis and a prior history of multiple falls (≥2) had nearly 3 times higher odds of secondary falls and those with osteopenia or osteoporosis had 4 times higher odds of a secondary fracture. We believe this information will help therapists/clinicians to identify people at risk of future falls/fractures and offer preventive services.


title: Saving Africa’s Children: Transnational Adoption and The New Humanitarian Order

contributor:
Chakraborty, Chandrima
Coleman, Daniel
Goellnicht, Donald
English and Cultural Studies

subject:
transnational adoption
youth and childhood studies
globalization
African Studies
postcolonialism
critical race studies
multiculturalism
motherhood
affect
intimacy
Bildungsroman
citizenship
nineteenth century
twentieth century
twenty-first century
angelina jolie
celebrity studies
olympics
black mothers
African mothers
missionaries
Mary Slessor
Victorian literature
transnational adoptees
human trafficking
slavery
Ethiopia
Nigeria

abstract: This PhD Dissertation was completed through 2011 to 2016 and was nominated for a CAGS-UMI Distinguished Dissertation Award.

abstract: My dissertation explores transnational adoptions of black African children by white Western parents as a site through which to think about global affective relationality and transnational histories within intimate proximities. The image of an interracial, transnational family can seem to be a fulfillment of the potential for transcendent love symbolized by humanitarian fundraisers such as Live Aid— a love that collapses borders and brings together races in multicultural bliss. Furthermore, adoptions of African children can potentially challenge discursive systems of categorization that frame the black body as existing outside the body politic. At the same time, however, we cannot understand transnational adoption without taking into account the histories of power that make possible and potentially limit the contours of these affective orientations. Indeed, representations of a transnational family consisting particularly of black African children and white Western parents not only invoke the logic of white moral motherhood within the context of contemporary globalization; they also point to European philosophical traditions that presuppose the colonizer’s right to the black body. In this project, thus, I ask: what are the sociopolitical and cultural motivations behind the desire to express humanitarian love towards African children through the act of adoption? How might these motivations create avenues for exclusion and exploitation even as they create new geographies of belonging? To answer these questions, this project brings the affective domain of contemporary transnational adoption between African children and white American parents into conversation with histories of colonial transnational intimacies and the precarious lived experiences of classed and racialized individuals in the African postcolony. In challenging popular celebratory fictions of the transnational family, it critically examines not only the utopian aspirations and social costs of transnational adoption as a humanitarian project, but also the very affect produced and channeled through adoption as a humanitarian act.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract:
My dissertation takes a multidisciplinary approach to analyze transnational adoptions of black African children by white Western parents. It offers answers to the following questions:

1. How do the ghosts of colonialism, along with the violent realities of globalization, expose the inequities hidden within idealized humanitarian narratives of rescue underlying global adoptions while at the same time revealing their transformative potential?

2. How can we account for the experiences and psychic struggles of the African adoptee, and what do their contradictions of idealized Western narratives tell us about the fantasies and anxieties of their Western parents?

Ultimately, I argue that while the transnational family suggests transformative transnational connections, Western humanitarian frameworks have also sought to manage the messiness of these connections, to fix white and black bodies into old colonial roles, and to exclude certain bodies, namely those of the African birth mothers, out of the affective realm of transnational adoption. At the same time, these attempts at management, I argue, only speak to the productive potential of these messy relations to transform and exceed colonial limitations.


title: Localized Feature Selection for Classification

contributor:
Reilly, James P.
Electrical and Computer Engineering

subject:
Local Feature Selection
Data Classification
Coma Outcome Prediction
Feature Selection

abstract:
The main idea of this thesis is to present the novel concept of localized feature selection (LFS) for data classification and its application for coma outcome prediction.

Typical feature selection methods choose an optimal global feature subset that is applied over all regions of the sample space. In contrast, in this study we propose a novel localized feature selection approach whereby each region of the sample space is associated with its own distinct optimized feature set, which may vary both in membership and size across the sample space. This allows the feature set to optimally adapt to local variations in the sample space. An associated localized classification method is also proposed.

The proposed LFS method selects a feature subset such that, within a localized region, within-class and between-class distances are respectively minimized and maximized. We first determine the localized region using an iterative procedure based on the distances in the original feature space.  This results in a linear programming optimization problem. Then, the second method is formulated as a non-linear joint convex/increasing quasi-convex optimization problem where a logistic function is applied to focus the optimization process on the localized region within the unknown co-ordinate system. This results in a more accurate classification performance at the expense of some sacrifice in computational time. Experimental results on synthetic and real-world data sets demonstrate the effectiveness of the proposed localized approach.

Using the LFS idea, we propose a practical machine learning approach for automatic and continuous assessment of event related potentials for detecting the presence of the mismatch negativity component, whose existence has a high correlation with coma awakening.  This process enables us to determine prognosis of a coma patient. Experimental results on normal and comatose subjects demonstrate the effectiveness of the proposed method.

abstract: Dissertation

abstract: Doctor of Philosophy (PhD)

abstract:
This study proposes a novel form of pattern classification method, which is formulated in a way so that it is easily executable on a computer.  Two different versions of the method are developed. These are the LFS (localized feature selection) and lLFS (logistic LFS) methods.  Both versions are appropriate for analysis of data with complex distributions, such as datasets that occur in biological signal processing problems. We have shown that the performance of the proposed methods is significantly improved over that of previous methods, on the datasets that were considered in this thesis.

The proposed method is applied to the specific problem of determining the prognosis of a coma patient. The viability of the formulation and the effectiveness of the proposed algorithm are demonstrated on several synthetic and real world datasets, including comatose subjects.


title: MANAGING PREOPERATIVE ANXIETY IN  CHILDREN UNDERGOING SURGERY

contributor:
Schmidt, Louis A.
Van Lieshout, Ryan J.
Neuroscience

subject:
Audiovisual aids
child
feasibility studies
psychometrics
preoperative anxiety
temperament
systematic review

abstract:
Objectives: 1) To examine the effectiveness of Audiovisual (AV) interventions at reducing preoperative anxiety (PA) and its associated outcomes in children undergoing surgery; 2) To assess the psychometric properties of a new scale, the Children’s Perioperative Multidimensional Anxiety Scale (CPMAS); 3) To examine the feasibility and acceptability of a novel tablet-based intervention, Story-Telling Medicine (STM), for reducing children’s PA; 4) To examine the relation between temperament and PA in the surgical context.
Methods: A systematic review of studies where the primary outcome was children’s PA was conducted (Study 1). A study of the reliability and validity of the CPMAS were assessed at preoperative assessment (T1), on the day of surgery (T2), and 1 month postoperatively (T3) was also undertaken (Study 2). The feasibility and acceptability of STM were then examined and compared its effect to Usual Care (UC) (Study 3). Finally, children’s temperament was examined using the Colorado Childhood Temperament Inventory at T1 along with the CPMAS assessed at T1 and T2 (Study 4).
Results: Fourteen of the 18 studies led to reductions in children’s PA (Study 1). The CPMAS demonstrated good internal consistency, stability and convergent validity across all visits (Study 2). The participant recruitment and study procedures were shown to be feasible and children in the STM group demonstrated greater reductions in CPMAS compared to the UC group (Study 3). Shyness predicted lower PA at T1, while sociability predicted higher PA at T1 and T2 (Study 4).
Conclusions: AV interventions appear useful but full-scale RCTs of these treatments are required to pinpoint those that are most effective. The CPMAS is a promising tool for evaluating children’s PA and preliminary evidence suggests that STM is a feasible intervention for reducing children's PA. Finally, our findings highlight the importance of considering individual differences in predicting anxiety in the surgical setting.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract:
Preoperative anxiety affects up to 5 million children in North America annually and is associated with many adverse psychological, behavioural, and health effects. These problems not only produce significant distress for children and families, but can have immediate and long-term effects on a child’s mental health and development.
Current methods to reduce preoperative anxiety in children (e.g., medications and psychological preparation programs) are limited by their expense and/or time-intensive nature. In an attempt to reduce children’s preoperative anxiety and its associated negative outcomes, this work examined the usefulness of audiovisual interventions in reducing children’s preoperative anxiety, sought to develop a new instrument to measure children’s preoperative anxiety, tested a new tablet-based application to reduce children’s preoperative anxiety, and examined the relation between children’s temperament and preoperative anxiety. The goal is to improve the surgical experience for children and families, and to reduce psychological and physical problems in children undergoing surgery.


contributor:
Bunting, B.T.
Geography

abstract: Title: Downslope Sequences of Sediment Transport and Deposition on High Arctic Slopes, Author: Tony J. Wilkinson, Location: Thode

abstract:
The transport of solid material in the form of
movements of suspended and bed load in overland flow is
examined. This movement achieves considerable magnitudes
in many rills flowing across low angle slopes during the
Arctic spring and summer. The occurrence of suspended
load is related to the intense runoff during the spring thaw
and summer rainstorms and also to the washing of fine sediments
trapped in the basal ice of transverse snowpatches. These
sediments which are transported from the interflow zone upslope a
from small but significant sedimentery deposits on backslopes
and low angle slopes. The latter deposits are more extensive
and appear to be incorporated in the regolith by processes
of frost action and turbulation.

abstract: Thesis

abstract: Master of Science (MS)


contributor:
Davies, D.M.
Biology

abstract: Title: An Interpretation of the Phylogeny of the Eusimulism-Group (Diptera:Simuliidae) with Descriptions of Six New Species, Author: Donald M. Wood, Location: Thode

abstract: The female, male, last stage larva and pupa of seventeen Ontario species of the Eusimulium-group are described, illustrated and keyed. Morphological and ecological knowledge of these and other species is used as a basis for interpreting the phylogeny within the group. This approach is extended, with the help of other representative species, to the derivation of a tentative phylogeny and zoogeography of the family Simuliidae. The finding from these studies contributed to the formation of a hypothesis of speciation.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: The Discrimination of Successive Sensory Impulses

subject: discrimination, successive sensory, impulses, intensity

abstract:
 Preliminary experiments were conducted to evaluate a theoretical model for predicting temporal numerosity data. The model was based on a hypothetical central unit of duration. It described the gating of sequentially presented auditory pulses. Experiment 1 offered partial
support for the prediction that events occurring within one unit 50 milliseconds in duration would be perceived as simultaneous. Results of Experiment 2 suggested that empty duration units occurring between sequential events would not affect number reported. The estimate of
the unit was 60 milliseconds. Experiment 3, an attempt to improve methodology, suggested values of the unit of approximately 75 and 106 milliseconds.

 Inadequacies of the model were discussed. Control experiments were considered to eliminate such cues for discrimination as duration and intensity differences.

abstract: Thesis

abstract: Master of Arts (MA)


title: Effects of Repeated Testing and Early Handling on Skin Conductance, Defecation and Activity in an Aversive Situation

contributor:
Roberts, L. E.
Psychology

subject: repeated testing, handling, skin conductance, defecation, aversive situation

abstract: The purpose of the present experiments was to determine whether a change in skin conductance is a reliable component of the fear pattern in the mouse. In these experiments, the sight of E was employed as an aversive stimulus. SC and defecation increased and activity decreased when the stimulus was presented. The SC and defecation responses tended to adapt with repeated testing. Decreases in activity on Day 1 were replaced by increases on subsequent days. Early handling severely attenuated the SC, defecation and freezing responses that would be normally seen on the first day of testing.

abstract: Thesis

abstract: Master of Arts (MA)


title: Decrease Over Time in the Generalization of Conditioned Suppression

contributor:
Kamin, L. J.
Psychology

subject: generalization, conditioned suppression, slope, gradient

abstract: A response conditioned to a specific stimulus will generalize to similar stimuli. Various reports have indicated that the slope of the gradient of generalization changes over a period of time. The experiments reported here investigated the generalization of an emotional response, originally conditioned to an 80 db. white noise to a 60 db. white noise. In different groups the tests for generalization were begun immediately after conditioning or after a 4 day waiting period. In further groups the animals' time during the delay period was variously taken up with bar pressing sessions; new conditioning trials with a light CS; unsignalled shock presentations, or they merely stayed in their home cages.

abstract: Thesis

abstract: Master of Arts (MA)


title: The Peripheral Effects of Cholinergic and Adrenergic Drugs on Palmar Skin Conductance in Humans

contributor:
Miller, R. D.
Psychology

subject: peripheral effects, cholinergic, adrenergic, drugs, palmar skin conductance, humans

abstract:
 The pharmacology of autonomic innervation to the peripheral skin conductance (SC) effector was studied. The drugs used included atropine, bretylium, acetylcholine (ACh),
epinephrine (EPI), and amphetamine. Drugs were administered by iontophoresis (IPS) and by local subcutaneous injection. Although several IPS procedures were used, all proved to be
inefficient and unreliable. Subsequent experiments using atropine and ACh supported the theory that innervation to the peripheral SC effector was mainly cholinergic. However, results obtained using EPI suggest that an adrenergic component might also be involved. It was concluded though that this component probably had little physiological significance. Experiments using amphetamine and bretylium were inconclusive. A comparison of behavioral and drug induced changes in SC suggested that the psychological relevance of SC might be improved through a range-correction based on pharmacologically determined SC range scores.

abstract: Thesis

abstract: Master of Arts (MA)


title: Pavlovian Conditioning and the Random Control Procedure

contributor:
Kamin, Leon J.
Psychology

subject: Pavlovian conditioning, random, control, procedure, suppression, CS

abstract:
 This thesis is concerned with control procedures employed in Pavlovian conditioning, in particular, the "truly random" control. Pilot work indicated that this procedure employed in a CER paradigm resulted in response suppression. Our first objective then was to examine this finding in a more formal experiment, as well as attempting to determine the cause of the observed suppression. In a second experiment, a variable predicted to affect the amount of conditioning within traditional conditioning theory was employed to determine the possible role of this variable in suppression produced by the random control procedure.

 It was found, in the first experiment, that two variations of the random procedure resulted in suppression in testing. The results of a third group indicated that the suppression was not due to a between-session discriminative function of the CS. A fourth group demonstrated, within
contingency logic, inhibitory control, but this group, like the others, showed suppression.

 In the second experiment, variations of stimulus conditions, none of which made the US contingent on the CS, resulted in marked differences in suppression in testing. Further, significantly different recovery rates of the operant baseline were noted both as a function of the recovery condition and of the CS employed in training.

abstract: Thesis

abstract: Master of Arts (MA)


title: The Effects of Mnemonic Instructions on Paired-Associate Learning

contributor:
Brooks, L. R.
Psychology

subject: mnemonic, instructions, paired-associate, learning, mechanisms

abstract:
 Different instructions for associating concrete nouns were given in a paired-associate learning situation. Material was varied to produce different types of interference against which to evaluate the effectiveness of the different instructions.

 The major findings were: (1) Specific instructions for association produced fewer errors than no specific instructions on the first list a subject learned. (2) After the first list, only the instructions which asked the
learner to produce a logical scene from the nouns produced fewer errors than non-specific instructions. (3) Specific instructions did not interact with material.

 Little evidence was found that the significant instructional effects were due to the specific characteristics
of the learners' mediations. These effects were more plausibly attributed to such general mechanisms as either giving the mediations during learning or having learning time occupied with irrelevant activity.

abstract: Thesis

abstract: Master of Arts (MA)


title: Alexander Invariants of Periodic Virtual Knots

contributor:
Boden, Hans U.
Nicas, Andrew J.
Mathematics

subject:
Knot Theory
Virtual Knots
Periodic Knots
Virtual Knot Theory

abstract:
In this thesis, we show that every periodic virtual knot can be realized as the closure of a periodic virtual braid. If K is a q-periodic virtual knot with quotient K_*, then the knot group G_{K_*} is a quotient of G_K and we derive an explicit q-symmetric Wirtinger presentation for G_K, whose quotient is a Wirtinger presentation for G_{K_*}. When K is an almost classical knot and q=p^r, a prime power, we show that K_* is also almost classical, and we establish a Murasugi-like congruence relating their Alexander polynomials modulo p.

This result is applied to the problem of determining the possible periods of a virtual knot $K$. For example, if K is an almost classical knot with nontrivial Alexander polynomial, our result shows that K can be p-periodic for only finitely many primes p. Using parity and Manturov projection, we are able to apply the result and derive conditions that a general q-periodic virtual knot must satisfy. The thesis includes a table of almost classical knots up to 6 crossings, their Alexander polynomials, and all known and excluded periods.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


contributor:
Johnson, Dean A. I.
Chemical Engineering

abstract: Title: DESS, an Executive System for Discrete-Event Simulation, and Application Studies of The Scheduling Operations in the Precipitation Circuit of a Bayer Process Plant for Alumina Extraction, Author: Raymond H. T. Wong, Location: Thode

abstract:
An executive system for discrete-event simulation of large, complex systems, such as chemical processes, is generated. Documentation on the system is provided in the form of a user's manual.

Two application studies, involving the simulation of the discrete,
scheduling operations in the precipitation circuit of a Bayer Process Plant, are made to illustrate the scope and method of the executive system and to yield further information on the precipitation process.

abstract: Thesis

abstract: Master of Engineering (ME)


title: An Analysis of Head Movements and Binocular/Monocular Viewing Conditions in Visual Position Discrimination

contributor:
Kinchla, R. A.
Psychology

subject: head movements, binocular, monocular, visual position discrimination, memory

abstract: The study concerns how human observers judge the relative position of successively presented points of light in an otherwise dark field. In particular, the possible role of involuntary head movements and binocular/monocular viewing conditions is considered. The data are analysed in terms of a mathematical model of the perceptual process which deals with short term memory for visual position. Contrary to previous suggestions in the literature, neither of the viewing variables proved to have a significant effect. In addition, the results provide a strong test of the theoretical model which appears to confirm the model's validity. The results of this study are shown to suggest a particular direction for future experimentation.

abstract: Thesis

abstract: Master of Arts (MA)


title: Sensory Bases of Schooling in Fish, in the Absence of Visual, Tactile and Chemical Stimuli

contributor:
Galef Jr., B. G.
Psychology

subject: sensory bases, fish, visual, tactile, chemical stimuli

abstract: Several experimental situations were designed to show that when all visual, tactile and chemical stimuli are eliminated, fish are still capable of attracting one another and orienting to one another. Attempts to ascertain the nature of this unknown sensory basis of schooling were unsuccessful.

abstract: Thesis

abstract: Master of Arts (MA)


contributor:
Woods, H.A.
Geography

abstract: Title: A Geographical Study of Culross Township, Author: George W. Sled, Location: Thode

abstract:
The purpose of this thesis is to discuss and explain both the physical characteristics and the historical developments of Culross Township, in order to show their relationship to each other, and to the present land use.

After describing the Township's physical setting - bedrock, geology, physiography, climate, natural vegetation, and soils - the author discusses the periods in historical development, the present land use, and finally, the urban geography of Culross.

Field work for the thesis was done by car and on foot during the weeks of late August and early September, 1962. Air photos facilitated the work. Important sources of information were the Bruce County Soil Report, the Census of Canada, and personal interviews with people of both the rural areas and urban centres of Culross.

abstract: Thesis

abstract: Bachelor of Arts (BA)


title: Polemos as Kinêsis: the effects of the Peloponnesian War on Athenian society and culture

contributor:
Corner, Sean
Classics

abstract: This is a study of war as a force for socio-economic, demographic, and political change in late fifth-century Athens. Thucydides famously describes the Peloponnesian War (431-404 BC) as the greatest kinêsis, or upheaval, ever to affect the Greek world. This protracted war placed great stress on the traditional social systems and institutions of the polis and the generation-long conflict is commonly regarded by historians as the nadir of classical Greek civilization and culture that witnessed the decline of the Greek city-state. Drawing on the testimony of Thucydides and his literary contemporaries, archaeology and epigraphy, I offer a richly textured account of the impact of the Peloponnesian War on several key aspects of Athenian life. In the first half of my thesis, I consider the material effects of the war on Athenian agriculture and food supply, investigating how the Athenians, as individuals and as a state, adapted to the economic pressures generated by the war. I argue that the material deprivation of Attica throughout the war prompted adaptive economic strategies that hastened and intensified the monetization of Athens and that the rebuilding of the agricultural economy in the aftermath of the war was a key factor in the commercialization of Athenian society in the fourth century. In the second half of the thesis, I document, diachronically, the distribution of the various burdens and opportunities engendered by conditions of protracted warfare among different citizen groups. I then demonstrate how the performance of the two essential civic obligations, military and financial service, was invoked in renegotiations of social and political privilege in the last decade of the fifth century. While there was some centralization in respect of these two areas, I argue that military mobilization and state finance in Athens continued to reflect the organizational principles and civic commitments of the democratic citizen-state into the fourth century. Thus, while offering a fine-grained account of the ways in which the Peloponnesian War was seriously disruptive to life in Athens, I demonstrate that it did not destroy the material and political conditions that provided for the flourishing of the democratic polis.

abstract: Dissertation

abstract: Doctor of Philosophy (PhD)


title: Interaction Between Auditory and Visual Discriminations Attempted Simultaneously

subject: interaction, auditory, visual discrimination, simultaneously, psychophysical

abstract: The study contains two discriminatory tasks which are attempted separately and simultaneoulsly. The subject is asked to judge the relative positions of successively presented points of light and/or to decide whether a test tone is added to continuous white noise during the interval between the two lights. It is noted that this design is similar to a retroactive interference paradigm. Analysis of the data shows that there is little interaction between decisions to each of the psychophysical tasks when they are attempted simultaneously. There also appears to be no significant change in sensitivity whether the tasks are attempted alone or together. It is suggested that-further experiments, involving different forms of visual memory, are needed.

abstract: Thesis

abstract: Master of Arts (MA)


title: Fracture in Low Carbon Steel

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

abstract: Title: Fracture in Low Carbon Steel, Author: Donald H. Timbres, Location: Thode

abstract:
A model for slip induced cleavage fracture has been proposed to account for the influence of both grain size and grain boundary carbide size on the fracture behaviour of low carbon steel.

It was shown in low carbon irons that grain boundary carbides may fracture due to inhomogeneous yielding of the ferrite matrix and provide important sources of cleavage cracks which may propagate into the ferrite matrix.

Reducing the size of the grain boundary carbide enhances the fracture resistance of the low carbon irons but continual removal has a deleterious effect.

The onset of intergranular fracture has been rationalized in terms of the stress concentrations at the head of a dislocation pile-up.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: PHENOTYPIC ANALYSIS OF SUBJECTS WITH UNCHARACTERIZED PLATELET FUNCTION DISORDERS

contributor: Medical Sciences (Blood and Cardiovascular)

subject:
platelets
lumi-aggregometry
bleeding risks
RUNX1 mutation
congenital platelet disorders
platelet function
platelet secretion
platelet aggregation

abstract:
While some rare and severe forms of platelet function disorders are now well characterized, many common types of platelet function disorders are not yet characterized. My hypothesis was that uncharacterized platelet function disorders that impair platelet function in aggregation and/or dense granule ATP release assays are associated with increased bleeding risk. The main goal of the thesis was to study the phenotype and bleeding risks for uncharacterized platelet function disorders, through analysis of the results from clinical laboratory tests of platelet function and for a detailed analysis of their reported bleeding symptoms. First, I assessed if lumi-aggregometry provides useful diagnostic information on platelet function and can be used to help decide if an individual has a bleeding disorder. Two cohorts of individuals were studied that had dense granule ATP release assessed in response to multiple agonists as part of a work-up for a bleeding disorder. Cohort I was comprised of individuals tested between January 2007 and June 2013 and cohort II was comprised of subjects tested at least twice by this assay prior to September 2015. Among subjects tested more than once for dense granule release defects as part of the work up for a bleeding disorder (cohort I; n=133; cohort II; n=17), normal findings with all tested agonists were often confirmed by the second test (cohort I: 83%; cohort II: 100%), but impaired release with multiple agonists was not often confirmed (cohort I: 34%; cohort II: 54%) and even if it was present, the finding was not predictive of a bleeding disorder. Consequentially, it was recommended that lumi-aggregometry should not be used to diagnose platelet function disorders. Next, I studied the bleeding risks associated with uncharacterized platelet function disorders, by evaluating subjects who had abnormal findings by validated assays, namely subjects who had defective aggregation responses to two or more agonists and/or dense granule deficiency. Bleeding history was evaluated using the International Society for Thrombosis and Haemostasis bleeding assessment tool (ISTH BAT) and the likelihood for bleeding symptoms/ problems, was estimated using odds ratios (OR) collected using the clinical history assessment tool - platelet (CHAT-P) for all affected subjects, a subgroup family with a mutation RUNX1, unaffected family
v
members and general population controls. Individuals with platelet function disorders (n=29) and the affected members of the family with the RUNX1 mutation (n=6) had elevated ISTH BAT scores (median: 9; range:0-18 and median: 8.5, range 4-15, respectively) and an increased risk of abnormal bruising (OR 15-65 and 11-67), nosebleeds (OR 23-40 and 19-121), menorrhagia (OR 6.5-29) and excessive bleeding after trauma or dental/surgical procedures (OR 9.5-44 and 15-77 ) and wound healing problems (OR 13 and 38) compared to general population control (n=60) and unaffected (n=12) family members. Overall, the platelet function disorders in the study present with a significantly increased risk of mild, rather than severe bleeding problems. These findings are important for individuals and healthcare providers to promote evidence-based care of common uncharacterized inherited platelet function disorders for individuals with RUNX1 mutations, dense granule deficiency and/or impaired aggregation responses.

abstract: Thesis

abstract: Master of Science (MSc)

abstract: Platelets are small blood cells that help stop bleeding. People who have platelets that do not work properly are more likely to bleed. Determining who has platelet problems can be challenging as there are limitations to diagnostic tests for these conditions. Additionally, the risks for bleeding in individuals with platelet problems are unknown. We looked at individuals with bleeding problems and found that a recommended test to assess platelet dense granule release, called lumi-aggregometry, wasn’t able to reliably identify persons with bleeding problems. Based on this, we recommend that lumi-aggregometry should not be used to diagnose platelet function disorders. We also found that individuals with uncharacterized platelet function disorders have increased risks for wound healing problems and experiencing bruising, nosebleeds, menorrhagia, and excessive bleeding after dental or surgical procedures. These risks are common among other mild bleeding disorders and will be important to differentiate bleeding risk from other platelet disorders.


title: COMBINED DIFFUSE OPTICAL SPECTROSCOPY – MAGNETIC RESONANCE IMAGING OF HUMAN CALF MUSCLES

contributor:
NOSEWORTHY, MICHAEL D.
FANG, QIYIN
Biomedical Engineering

subject:
DIFFUSE OPTICAL SPECTROSCOPY
NEAR-INFRARED SPECTROSCOPY

abstract: A magnetic resonance imaging (MRI) compatible near infrared spectrometer (NIRS) system was developed and evaluated for continuous-wave diffuse optical spectroscopy (DOS) and concurrent functional MRI measurements of human muscle. Phantom and in-vivo experiments using the system’s fiber bundle suggested that an isolation distance greater than 8 mm needs to exist between adjacent illumination-detection channels. Using single and probe-pair arrangements (inter-fiber separations of 80 µm and 5 mm, respectively), in-vivo DOS point-measurements (total=20 images) were performed on 1) the antecubital vein and a reference tissue area and 2) the lower leg at the medial (MG) and lateral gastrocnemius (LG) under isokinetic exercise. Mean spectral morphological differences and relative mean intensity changes at Hemoglobin key wavelengths were found, namely reduced mean pixel intensity (~30%) for the vessel-area and a signal change of ~1-4% between the rest and the recovery condition at both muscle locations for the single-probe configuration. Subsequent work is necessary to evaluate the oxygenation assessment capabilities of this system. Lastly, experiments were performed in which two volunteers had concurrent measurement of optical and blood oxygen level dependent (BOLD) MRI, before and following exercise. The same probe arrangement was used for DOS measurements for this experiment. The BOLD signal was studied for manually-derived ROIs. BOLD recovery curves corresponding to the LG followed routine temporal progression where immediate post-exercise signal is hypointense, followed with a sigmoidal-shaped recovery. A decrease ranging between ~0.1-20% was found in the normalized mean spectral signal (20 images) for recovery with reference to the rest condition at both muscle locations for single-probe measurements and for one probe-pair measurement (for 800,808 and 850 nm). The specific trend of the measured decrease in the mean spectral curves during recovery was not consistent among these trials. Future steps include repeatable phantom experiments, increased optical power delivery, enhanced skin contact and improved reflectance measurements

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: UTILIZING THE PREOPERATIVE PF4-DEPENDENT IMMUNE RESPONSE TO PREDICT ANTI-PF4/HEPARIN ANTIBODY PRODUCTION IN A COHORT OF PATIENTS UNDERGOING CARDIOPULMONARY BYPASS SURGERY

subject:
Heparin-induced thrombocytopenia
Platelets
Immunity
Cardiopulmonary bypass
Translational
Hematology

abstract: Background: Heparin-induced thrombocytopenia (HIT) is an iatrogenic immune-mediated prothrombotic disorder that is a direct consequence of heparin therapy. In HIT, antibodies are generated against complexes of platelet factor-4 (PF4) and heparin. Immunoglobulin G (IgG) antibodies bind to PF4/heparin complexes and cause Fc-receptor-mediated activation of platelets and monocytes. PF4 binds endogenous heparin-like polyanions to reveal cross-reactive epitopes that can also bind anti-PF4/heparin antibodies. Based on this observation, researchers have suggested that exposure to PF4/polyanion complexes can sensitize immune cells to become activated to produce HIT antibodies following iatrogenic heparin exposure. Research objective: The objective of this study is to determine whether the preoperative PF4-dependent immune response is associated with postoperative anti-PF4/heparin antibody production in a cohort of patients undergoing cardiopulmonary bypass surgery. Materials and methods: To assess the preoperative immune response to PF4, we utilized two assays: (1) a 3H-thymidine uptake assay to measure peripheral blood mononuclear cell (PBMC) proliferation in response to in vitro stimulation with PF4 and (2) a PBMC ELISPOT assay to measure the preoperative frequency of PF4-specific antibody-secreting cells. Proliferation was quantified as a stimulation index (SI). We then utilized a PF4/heparin-dependent enzyme immunoassay to measure the in vivo levels of anti-PF4/heparin antibodies produced by these patients in the postoperative period. Results: Our findings suggest that preoperative PF4-dependent proliferation is not associated with postoperative polyspecific anti-PF4/heparin antibody production [Spearman’s ρ (95% CI) = –0.02 (–0.32, 0.28), P = 0.91]. PF4-dependent proliferation had a weak negative association with postoperative anti-PF4/heparin IgG antibody production [Spearman’s ρ (95% CI) = –0.31 (–0.56, –0.02), P = 0.04], but was not associated with postoperative IgM or IgA anti-PF4/heparin antibody production [IgM: Spearman’s ρ (95% CI) = –0.04 (–0.33, 0.26), P = 0.78; IgA: Spearman’s ρ (95% CI) = –0.05 (–0.34, 0.25), P = 0.73]. Qualitative analysis demonstrated that two patients who had the strongest preoperative PF4-dependent proliferation responses produced the highest postoperative levels of anti-PF4/heparin IgM antibodies, but this relationship was not observed with postoperative anti-PF4/heparin IgG antibodies. Moreover, the preoperative frequency of PF4-specific antibody-secreting cells (ASCs) was also not associated with postoperative levels of anti-PF4/heparin IgM or IgG antibodies [IgM: Spearman’s ρ (95% CI) = 0.30 (–0.79, 0.93), P = 0.683; IgG: Spearman’s ρ (95% CI) = –0.21 (–0.92, 0.83), P = 0.600]; however, this was only completed on five patients and so the sample size should be increased before any meaningful conclusions can be drawn. We also demonstrated that PF4-dependent proliferation increases 5–6 days following cardiopulmonary bypass surgery [geometric mean (GM) postoperative PF4 alone proliferation (in SI) vs. GM preoperative PF4 alone proliferation (in SI) ± SEM: 23.7 ± 1.3 vs. 6.9 ± 1.5, P = 0.009]. Conclusions: Based on our findings, we conclude that preoperative PF4-dependent proliferation is unable to predict postoperative anti-PF4/heparin antibody production in this cohort of cardiopulmonary bypass patients. Due to the small sample size, we are unable to make conclusive statements regarding the relationship between preoperative PF4-specific ASC frequency and postoperative anti-PF4/heparin antibody production, but our findings would suggest that an association does not exist between these two variables in this patient cohort. Cardiopulmonary bypass surgery, however, may mobilize the postoperative immune cell repertoire to become activated against the self-protein PF4 and may therefore contribute to the postoperative HIT immune response.

abstract: Thesis

abstract: Master of Science (MSc)

abstract: Background: Heparin-induced thrombocytopenia (HIT) is an  immune-mediated disorder that is a direct consequence of heparin therapy. In HIT, antibodies are generated against complexes of platelet factor-4 (PF4) and heparin. Antibodies bind to PF4/heparin complexes and cause  activation of platelets and monocytes. Researchers have suggested that exposure to PF4/polyanion complexes can sensitize immune cells to become activated to produce HIT antibodies following iatrogenic heparin exposure. Research objective: The objective of this study is to determine whether the preoperative PF4-dependent immune response is associated with postoperative anti-PF4/heparin antibody production in a cohort of patients undergoing cardiopulmonary bypass surgery. Materials and methods: To assess the preoperative immune response to PF4, we measured cellular proliferation in response to PF4 stimulation and the preoperative frequency of PF4-specific antibody-secreting cells. We also measured the level of anti-PF4/heparin antibodies following surgery. Results: Our findings suggest that preoperative PF4-dependent proliferation is not associated with postoperative anti-PF4/heparin antibody production. Moreover, the preoperative frequency of PF4-specific antibody-secreting cells (ASCs) was also not associated with postoperative levels of anti-PF4/heparin antibodies; however, this was only completed on five patients and so the sample size should be increased before any meaningful conclusions can be drawn. We also demonstrated that proliferation increases 5–6 days following cardiopulmonary bypass surgery. Conclusions: Based on our findings, we conclude that preoperative proliferation is unable to predict postoperative anti-PF4/heparin antibody production in this cohort of patients. Due to the small sample size, we are unable to make conclusive statements regarding the relationship between preoperative ASC frequency and postoperative anti-PF4/heparin antibody production. Cardiopulmonary bypass surgery, however, may mobilize the postoperative immune cell repertoire to become activated against the self-protein PF4 and may therefore contribute to the HIT immune response.


title: Some Attempts to Manipulate the Human Alpha Frequency and the Application of a Fourier Analysis to the EEG Frequency Spectrum

contributor:
Kristofferson, A. B.
Psychology

subject: human alpha frequency, application, Fourier Analysis, EEG, spectrum, dextrose ingestion

abstract:
 The present study has two objectives. The first is to apply a reliable and valid technique of eeg frequency analysis to the measurement of the human alpha rhythm. The second objective is to find a chemical agent which will alter an individual's dominant occipital frequency 2 Hz from its resting frequency. The techniques used are: dextrose ingestion, fasting, oxygen inhalation, hyperventilation, carbon dioxide inhalation, diamox, alcohol, librium and dexedrine. The treatments which did produce a 2 Hz shift in dominant frequency
also produced new peaks in other parts of the frequency spectrum. Evidence is presented which suggests that the alpha rhythm can be made to fluctuate over a very narrow frequency range (approx. 1 Hz ).

abstract: Thesis

abstract: Master of Arts (MA)


title: Interval Effects in Tachistoscopic Recognition

contributor:
Newbigging, P. L.
Psychology

subject: interval effects, tachistoscopic, recognition, tone-stimulus

abstract: Three experiments, involving 250 subjects, were performed which support the conclusion that a tone cue presented shortly before a tachistoscopic stimulus facilitates tachistoscopic recognition. With tone-stimulus intervals below two seconds no threshold differences occurred. With intervals between two and eight seconds, the shorter the interval was, the lower thresholds were, and the more practice decrement observed. Experiment II showed that while the tone-stimulus interval affects thresholds the most, the interval between successive exposures of a stimulus affects thresholds. We concluded that as this interval is lengthened, the subject forgets information already gained. Experiment III showed that training in a reaction time task transferred positively to a tachistoscopic task when a two second tone-stimulus interval was used in both tasks. Reasons for the facilitative effect of the tone were discussed.

abstract: Thesis

abstract: Master of Arts (MA)


title: Uniform Ductility of High Carbon Steels

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

abstract: Title: Uniform Ductility of High Carbon Steels, Author: Masaru Yamaguchi, Location: Thode

abstract:
The effect of microstructure on  uniform ductility was analyzed by utilizing a fact that uniform ductility is equal to the work hardening coefficient in parabolic true stress-true strain equation. A Hall-Petch relation was found for the flow stress of lamellar and spheroidized high carbon steels. The uniform ductility was formulated as a function of reciprocal flow stress and found to fit the experimental data.</p.
An attempt to interpret the results obtained, based on the scanning and transmission electron microscopy observations, were given.

abstract: Thesis

abstract: Master of Engineering (ME)


title: Constructing a New Femininity

title: Popular Film and the Effects of Technological Gender

contributor:
Savage, Anne
English

subject: Science Fiction, gynoids, abjection, Simulacra

abstract: This project applies critical media and gender theories to the relatively unexplored social space where technology and subjectivity meet. Taking popular film as a form of public pedagogy, the project implicates unquestioned structures of patriarchal control in shaping the development and depiction of robotic bodies. The project was spurred from a decline in critical discourse surrounding technology’s potential to upset binaried gender constructions, and the increasingly simplified depictions of female-shaped robots (gynoids) as proxies for actual women. By critically engaging assumptions of gender when applied to technology, the project recontextualizes fundamental theories in contemporary popular film.

abstract: Thesis

abstract: Master of Arts (MA)


contributor:
Radforth, N.W.
Biology

abstract: Title: A Study of Growth and Morphogenesis in Oedogonium cardiacum, Author: James A. Wilfong, Location: Thode

abstract:
The investigations concerned the effect of some environmental factors on growth and zoospore production in Oedogonium cardiacum. Media and culture techniques were developed which favoured optimum growth, zoosporulation within a define time period.

The normal sequence of cell divisions was established for young filaments. This was a problem of fundamental interest in algal ontogeny.

The normal sequence of cell divisions in filaments was disturbed by treatment with ionizing radiation. A different ontogenetic sequence was induced by ionizing radiation and this sequence was often associated with those individuals which were classified as non-survivors.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


contributor:
Tomlinson, R.H.
Chemistry

abstract: Title: The Gamma-Radiolysis of HCl-C2H4 Mixtures and Other Related Topics, Author: Eric E. Wigg, Location: Thode

abstract: The gamma-radiation induced reactions occurring in the three vapour phases systems; CH4-TiCl4, C2H4-TiCl4 and C2H4-HCl, have been studied. A solid product was obtained in the first system, which has been identified as a mixture of TiCL3 and chlorinated organic polymer. Low molecular weight chlorinated hydrocarbons were observed to form in the other two systems. The reaction taking place in the C2H4-HCl system has been shown to be a chain reaction, the chain propagator being a chlorine atom. A reaction mechanism has been devised, which gives kinetic expressions governing the rates of formation of the chlorinated products, which is in agreement with the experimental data.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Investigation of Sub-Pitch Spatial Resolution for Pixelated CZT X-Ray Detector

contributor:
Wu, Xiaolin
Electrical and Computer Engineering

subject:
CZT
CT
spatial resolution
cancer

abstract:
As everyone knows, cancer is one of the greatest health enemies of mankind and became a major public health problem all over the world. Moreover, lung cancer is the most common global cancer leading to more than 1.3 million estimated deaths annually worldwide. Breast cancer is the most common cancer and the 2nd leading cause of death from in women in the US, Canada, and China. Therefore an instrument for the early diagnosis and monitoring of cancers in areas such as lung and breast is immensely important and necessary.

The cadmium zinc telluride (CZT) semiconductor is a kind of novel radiation detector that can provide detailed information about spatial position. Also, the energy resulting from interactions between the radiation and the CZT material can also be assessed giving this type of detector added value in disease evaluation. A great deal of work on CZT detectors has been done  for breast CT scanning. Furthermore, the CZT detector is also a potential solution for problems in lung cancer CT evaluation where the lack of energy information and high radiation exposure are less than ideal. Since sub-millimetre spatial resolution is required for post-contrast thoracic CT assessment, and $100~\mu m$ or better is critical for breast CT, the investigation of spatial resolution for CZT detectors is essential.

In this thesis, the interactions within CZT detectors were analyzed.  The influence of different configurations, including adjustment of anode size, gap size, detector thickness and bias voltage, were discussed.  Next the methods to evaluate two kinds of signals (collected and transit signals), are provided in Chapter~2. In Chapter~3, an intensity difference method and an  intensity ratio method for estimating the sub-pitch spatial resolution were described in detail. Finally, a detector spatial resolution between $10~\mu m$ and $20~\mu m$ was achieved using the collecting signal intensities ratio method and a $4~mm$ thick CZT detector with gap size of $g=50~\mu m$ and bias voltage of $V=300V$.

Future work should focus on the contributions from characteristic X-rays emitted from cadmium and tellurium atoms. Also, the work presented was only on pixelated arrays and further assessment of cross-strip electrode detectors could also be of benefit. Lastly based on simulations done in this thesis all photons were assumed to strike the cathode at 90 degrees.
Future work should also include non-orthogonal directions for photons.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: A Response Selection Model for Choice Reaction Time

contributor:
Link, S. W.
Psychology

subject: response selection model, choice reaction, time, Fast Guess Model,

abstract:
 The binary choice Fast Guess Model of Ollman and Yellott was generalized to a multiple choice model and six subjects were run in a choice reaction time task to test the model.
Stimulus set sizes of two, four and six were used and response accuracy and speed motivation was manipulated through specific instructions which were changed from trial to trial. Three
different motivational instructions were used. In all cases, subjects were to respond with maximum accuracy but were also told on each trial to either disregard the duration of their
response, respond within 440 milliseconds or respond within 300 milliseconds.

 The generalized Fast Guess Model was rejected because response time parameters of the SCR state were found to change across response accuracy-speed motivation instructions and across
stimulus set sizes. Implications of these results for other classes of models were also discussed.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Thermomechanical Behavior of Shape Memory Polymer Films and Interfacial Characteristics of Metal – Film Laminates

contributor:
Jain, Mukesh
Mechanical Engineering

abstract:
Metal polymer laminates have had wide applicability in the automotive industry. In recent times, there has been an interest to introduce polymer films over metal parts prior to their forming process. This can not only result in cost cutting, but also fulfill the need for polymer films serving as paint replacement product. However, the applicability of such laminates has been limited due to the tendency of the polymer films to delaminate and wrinkle during processing and usage.
In this work a Shape Memory Polymer (SMP) – Stainless Steel (SS) laminate system has been studied for its integrity and interfacial strength under a wide range of test conditions. FE analysis of SMP – SS laminate systems have been done to help understand the role of stresses and strains in the polymer film and adhesive layers in relation to delamination and wrinkling. Further, the effect of the geometry of the laminate systems on the tendency for wrinkle formation has been analyzed.
In addition, the shape recovery phenomenon of the polyurethane films has been studied in detail at temperatures below and above the glass transition temperature Tg. The polymer is found to have 100% shape recovery, even from large deformations as 40% strains at room temperature when the material is highly crystalline. As the temperature is increased to 50°C, the material becomes viscous due to plastic dislocations and slips occurring in the polymer chains which result in decreased shape recovery as compared to room temperature. At lower temperatures such as 10°C the material becomes very stiff and also exhibits high shape fixity and low strain recovery. A specialized constitutive material model incorporating the shape memory behavior of polyurethane has been used in conjunction with themo–mechanical cycling process within the temperature range of 15°C–40°C.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: Free Radical Polymerization of Styrene in Continuous and Batch Reactors

contributor:
Hamielec, A. E.
Chemical Engineering

subject: free radical, polymerization, styrene, continuous, batch, reactors

abstract:
 Polymerization of styrene was carried out in continuous and batch reactors using azobisis obutyronitrile as initiator and benzene as solvent. Monomer conversion, molecular weight distribution (MWD) and viscosity were measured.

 Corrections to the conventional kinetic mechanism using results from the continuous reactor were determined. These corrections were applied to the batch reactor kinetic model and the conversion and MWD thus predicted were compared to experimental results. It was found that the corrections applied to the batch system were not adequate to give accurate predictions of conversion and MWD.

 A short computer study of the effect of oscillating monomer flow and temperature, as opposed to steady flow, on a transient continuous reactor was also carried out. It was found from this study that at low conversions oscillations in monomer flow will not affect the time average conversion and molecular weight. Oscillations in temperature caused an increase in time average conversion and a decrease in time average molecular weight as compared to results obtained when the reactor was operated at a steady temperature which was the average of the oscillating temperatures.

abstract: Thesis

abstract: Master of Engineering (MEngr)


title: The Effect of Hearing Loss and Hearing Aid Amplification on Predicted Pitch Salience

contributor:
Bruce, Ian
Electrical and Computer Engineering

subject:
Hearing aids
music
pitch salience
music perception

abstract:
While hearing aids are optimized for listening to and hearing speech in noisy environ- ments, there are still many challenges when using hearing aids to listen to music. This could mean that hearing impaired individuals do not perceive music the same way a normal hearing person would. When two musical tones are played simultaneously at equal presentation levels, the tone with the higher frequency will be perceived as more salient for a normal hearing person. This phenomenon is referred to as the high voice superiority effect. This study examined how different types of hearing loss affect the neural pitch salience profile obtained with a computational model of the auditory periphery. More specifically, the high voice superiority effect was examined by generating neural pitch salience profiles for different combinations of simultaneous tones at different sound presentation levels. To model other aspects of hearing aid processing, an Analog to Digital Converter (ADC) and simple noise reduction filter were added to some of the simulations.
The results show that less severe hearing loss types tend to have pitch salience profiles closer to normal after hearing aid amplification. The addition of the ADC to the simulation seems to have little effect on the pitch salience, whereas the noise reduction filter has a noticeable effect on how closely the pitch salience profile matches that of a normal hearing ear. For each different type of hearing loss there appears to be a trade-off between the ability of the upper tone and the lower tone to match normal hearing performance. Along with simulated piano tone results, pitch salience results are shown for live recordings of several instruments through hearing aids. The recordings are compared to ideal versions of the instrument parts. This study provides a starting point to improve hearing aid processing for music perception.

abstract: Thesis

abstract: Master of Applied Science (MASc)

abstract: While hearing aids are optimized for listening to speech, they still face challenges when listening to music. This study examined how different types of hearing loss and hearing aid amplification affect music perception, using the measure of neural pitch salience. The results show that less severe hearing loss types tend to have pitch salience profiles closer to normal after amplification. Along with simulated piano tone results, pitch salience results are shown for live recordings of several instruments through hearing aids. The recordings are compared to ideal versions of the instrument parts. This study provides a starting point to improve hearing aid processing for music perception.


title: Anomalous Magnetism in Ferromagnetic Pyrochlores as Revealed By Neutron Scattering

contributor:
Gaulin, Bruce
Physics and Astronomy

subject:
neutron
pyrochlore
frustrated magnetism
small angle scattering
inelastic scattering

abstract:
This work is the result of two separate lines of study into the family of frustrated rare-earth pyrochlores with ferromagnetic interactions. The first is an examination of Yb2Ti2O7 and Ho2Ti2O7 through small angle neutron scattering (SANS) techniques. The sensitivity to anisotropic ferromagnetic correlations of SANS makes it an ideal tool to investigate the anomalous scattering of Yb2Ti2O7 , and to take a closer look into the low Q region of the spin ice Ho2Ti2O7 , where long range dipolar effects modify magnetic scattering. We show that in Yb2Ti2O7 the ferromagnetic order observed by other researchers coexists with short range HHH correlations to 0.03 K. We identify a new feature in Yb2Ti2O7 , a medium range (on the order of 100 ̊A) ferromagnetic correlation which appears to correlate well with the systems heat capacity anomaly. In Ho2Ti2O7 , we observe isotropic magnetic scattering in the low Q region that correlates to the system heat capacity anomaly.
The second research project involves the system Ho2Sn2−xTixO7 with x=0,0.5,1,1.5,2. We use SQUID magnetometry and inelastic neutron scattering to examine the effects of B-site disorder on the spin ice system. We find some discrepancies with previous generation instrument results for the crystal electric field (CEF) Hamiltonian, and find results consistent with our previously hypothesized picture of the effects of B-site disorder on the CEF levels. We also observe increased spin dynamics in the disordered compounds, which is consistent with recent theory work predicting a transition to a quantum spin liquid phase in disordered non-kramers spin ice compounds.

abstract: Thesis

abstract: Master of Science (MSc)


title: Upper Triassic Eumorphotis and Meleagrinella (Bivalvia) from British Columbia

contributor:
Westermann, G.E.G.
Geology

abstract:
Collections of the Aviculopectinids
Eumorphotis and Meleagrinella from the Upper Triassic of
British Columbia are described. Four species of Eumorphotis
have previously been known only from Indo-China and one from
Siberia. Five species of Eumorphotis and one of Meleagrinella
are new. Phylogenetic relationships and affinities of the
fauna are discussed. The present work is the first detailed
study of these Aviculopectinids which are among the important
biostratigraphic indices of the Triassic .

abstract: Thesis

abstract: Master of Science (MS)


title: A SYSTEMATIC ANALYSIS OF ENTREPRENEURIAL LEARNING: PRACTICE AND EFFECTS

contributor:
Honig, Benson
Business Administration

subject: Entrepreneurship education

abstract:
This thesis aims to develop a deeper understanding of entrepreneurship education as a type of entrepreneurship support. We study the overall entrepreneurship support systems, the pedagogical models developed for students with different level of entrepreneurship experience, and the long-term influences of entrepreneurship education on students.

Entrepreneurship education and training has become very popular in universities, colleges, and business development centers world-wide, and has been of great interest in academia also. However, the entrepreneurship teaching is usually not informed by solid theories, and students’ different learning needs are not taken into consideration. In addition, the long-term influences of entrepreneurship education on students are unclear.

This thesis consists of four manuscripts, each of which is a co-authored paper that presents an individual study.

Study 1 is a comprehensive literature review of 122 journal articles that disentangles multiple conceptualizations used to research entrepreneurship support and examines the effectiveness of each source and type of support. We present our theorizations found and explore how three prevailing management theories could motivate theoretical refinements in the field. We also identify areas for future research and offer guidance on how to improve the relevance of entrepreneurship support studies.

Study 2 develop a set of conceptual models anchored in learning theory regarding how entrepreneurship education should be taught to students. These conceptual models are built on the techniques of entrepreneurship pedagogy such as experiential learning. They are developed for three groups of students: students without any entrepreneurship experience, students with previous entrepreneurship experience, and students who are currently running their start-ups. A set of potential variables that could be used for course evaluation purposes is also included. Choosing a model pertinent to students’ attributes, lecturers could hence design entrepreneurship courses suitable for the students. This study also provides novel insights into educators’ design of entrepreneurship programs.

Study 3 is an approximately four-year quantitative longitudinal study examining the stability of students’ attitude, perceived behavior control, subjective norm, and intention to entrepreneurship over time, and the role of entrepreneurship education in this process. Findings have implications for interpreting extant entrepreneurial literature, and policy and practice related to nascent entrepreneurship development and support. The results support our argument that the theoretical and practical value of entrepreneurship literature should hinge on the temporal stability of the attitudinal and intentional constructs used.

Study 4 is a qualitative study exploring what are the important knowledge/skills students learned from the entrepreneurship courses they took on average five years previously, which pedagogical approach seems most effective, whether the courses are useful for entrepreneurs and company employees. The results show that the experiential learning approach is the most effective pedagogical approach, and entrepreneurship education can be useful for entrepreneurs and certain types of company employees.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Mass Transfer with Simultaneous Chemical Reaction in Drops for Liquid-Liquid Systems

contributor:
Johnson, A.I.
Science

abstract: Title: Mass Transfer with Simultaneous Chemical Reactions in Drops fir Liquid-Liquid Systems, Author: Hideki Watada, Location: Thode

abstract:
This dissertation is divided into three major self-contained
sections. The first one contains a review of previous work in the
field of mass transfer in drops for liquid-liquid systems.

The second section outlines the numerical solutions of the
continuity equation for for forced convection with simultaneous chemical
reaction in the dispersed phase. The solutions are compared with those
predicted by existing theoretical models for mass transfer in the
dispersed phase.

The third section describes the experimental equipment and
method of operation. Physical mass transfer in drops is studied
initially. This established a basis for evaluation the effect of
chemical reaction on the rate of mass transfer in a later study. The results from these experimental studies are used to test the ability
of existing models to predict mass transfer with simultaneous chemical
reaction in drops.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: CLINICAL DECISION MAKING IN PARAMEDICINE

contributor:
Monteiro, Sandra
Health Science Education

subject:
Paramedicine
Clinical Decision Making
Expertise
Feedback
Practice Guidelines
Medical Directives
Diagnostic Accuracy
Ontario

abstract:
Title:
Clinical Decision Making in Paramedicine

Author(s) & affiliation(s):
Michael Eby – McMaster University, Hamilton, ON, Canada
Sandra Monteiro – McMaster University, Hamilton, ON, Canada
Geoffrey Norman – McMaster University, Hamilton, ON, Canada
Walter Tavares – McMaster University, Hamilton, ON, Canada

Background:
Paramedics are frequently required to make rapid decisions in an uncontrolled, dynamic environment, often with limited diagnostic information. In Ontario, paramedic practice is based on a set of provincial medical directives that provide diagnostic and treatment criteria. Unsupervised deviation from these directives is classified as a form of error and highly discouraged. To date, there is little known about how years of clinical experience or level of certification affect the way these medical directives are used. The purpose of this study was to examine the relationship between paramedic experience, training and accuracy of treatment decisions when faced with patients who meet and fall outside of the existing medical directives.

Methods:
Thirty-one participants (16 experienced / 15 novice) were recruited from two paramedic services in Ontario. “Experienced” was defined as in-practice for 5 years or more. Participants were presented with 9 scenarios; in 6 scenarios, the patient presentation fit within the existing directives, while in 3 scenarios, the patient presentation fell outside the medical directives. Multiple-choice responses were used to capture participants’ decisions to treat or not treat the patients. Responses were scored and submitted to a mixed-factorial ANOVA to evaluate differences in accuracy between case types, years of experience and level of training.

Results:
There was a significant effect of case type (p < 0.004). Accuracy was lower when the patient presentation did not meet the criteria of the medical directive (76.34% (CI = 67.15% to 85.53%) vs. 98.35% (CI = 96.55% to 100%) when they did. There was no effect of years of clinical practice or level of certification.

Conclusion:
The results suggest both novice and experienced paramedics are able to accurately apply medical directives, however, there is a significant decrease in accuracy when the patient presentation does not fit one. This variation in practice may have a significant impact on patient safety, and further research is required to determine what factors may be causing this decreased accuracy.

abstract: Thesis

abstract: Master of Science (MSc)

abstract: Paramedics work in a fast-paced, dynamic environment. The types of patients, and the situations paramedics encounter are different every day. Paramedic practice is based on a series of provincial medical directives that outline the different proceedures, medications and types of patients that can be treated. While these directives cover many of the cases paramedics encounter, there will always be cases that don’t “fit”. The purose of this study is to see if paramedics approach those types of cases in a different way, and if their years of experience or level of training change how good they are at idenfiying what patients require treatment. As there is very little paramedic specific research on this topic, this study will serve as a starting point for future research and hopefully stimulate discussion about paramedic practice, and how to support paramedics getting better at their jobs.


contributor:
DeMalherbe, M.C.
Mechanical Engineering

abstract: Title: Some Studies on the Forming of Anisotropic Metals, Author: Ronald D. Venter, Location: Thode

abstract:
The diffuse and local inst ability criteria associated with sheet
metal forming limits are investigated for materials having a wide range
of properties. The results are compared with available experimental data.
An alternate method based on the pre-existence of an initial inhomogeneity
or weakness within the material is developed. The straining paths
which are dependent upon the particular applied stress ratio are
presented and the results correlated with experimental limit strains
obtained from the hydrostatic bulging of aluminum diaphragms in
circular and elliptical dies.

A method based on the finite difference technique is developed
for the construction of slip-line fields when the material has a
defined degree of anisotropy. Solutions for the indentation of semi-infinite and finite depth anisotropic media are developed and
compared with the results obtained from the indentation of aluminum;
specimens for which the degree of anisotropy is evaluated from yield
stress considerations. The solutions are extended to include the
extrusion of anisotropic materials and the approximate, but simpler,
upper bound limits. The analogue between planeplane strain slip-line field
solutions and the collapse loads associated with flat plates are
investigated for anisotropic materials .

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


contributor:
Galef, Bennett G.
Psychology

abstract: Title: Interactions Between Copy-When and Copy-Who Strategies of Social Learning, Author: Lauren Dukas, Location: Thode

abstract:
Theoretical models predict conditions under which individuals should forgo individual
learning and instead copy the behaviours of others. These predictions are categorized as
copy-when and copy-who social learning strategies, and pertain to when an individual
should rely on social learning to guide its behaviour and whom that individual should
select as a demonstrator. In general, and particularly in Norway rats (Rattus norvegicus),
there is greater empirical support for copy-when than copy-who strategies. In this thesis,
we present a novel approach to the study of social learning in hypothesizing that
interactions exist between copy-when and copy-who strategies that predispose individuals
to be more discriminating when choosing whom to copy. Consequently, the failure of
some studies to find evidence of copy-who strategies may be due, in part, to experimental
protocols that did not incorporate critical copy-when variables. We tested the prediction
that 'observer' Norway rats would preferentially copy successful over unsuccessful
demonstrators when uncertain about the relative safety of two novel foods, but not when
certain. The results of two experiments presented herein, confirm our prediction that
observer rats do copy successful demonstrators when uncertain. Additionally these results
are the first to show that Norway rats actively select particular conspecifics to serve as
models when choosing whom to copy. Further investigation of similar interactions
between copy-when and copy-who strategies promises to be a rewarding avenue of
research for both theoretical and empirical studies of social learning.

abstract: Thesis

abstract: Master of Science (MS)


title: Social and Reproductive Behaviour of the Smooth-billed Ani

contributor:
Quinn, James
Biology

abstract:
Sentinel behaviour has been widely described in a variety of species. The term
sentinel behaviour is typically used to describe a vigilant animal that watches over
foraging conspecifics. Several studies have examined the advantages of sentinels
in providing early detection of predators while increasing uninterrupted foraging
opportunities. However, very little effort has been made to perform formal tests
of coordination of sentinel bouts (i.e. the defining feature of sentinel behaviour).
For the first portion of this thesis (Chapter II), I tested for sentinel coordination
in Smooth-billed Anis. By examining differences between observed and expected
proportion of time without a sentinel, and overlap between multiple sentinels, I
show that Smooth-billed Anis do not possess a coordinated sentinel system and
may have multiple sentinels overlapping at once.
Competitive dynamics of broods have been suggested to influence how adaptive
sex ratios allocation can occur across hatching order. Furthermore, the influences
of maternal condition and variance in reproductive success (i.e. Trivers-Willard
hypothesis) have also been argued to inform sex ratio allocation of offspring sex
ratios in a variety of animals. In the latter part of my thesis (Chapter III), I report
a sex ratio bias of last-hatched Smooth-billed Anis chicks and show that rainfall (a
proxy for maternal condition) does not have a statistically significant influence on
the sex ratio of broods. While a male bias in last hatched chicks may represent a
tactic to mitigate asymmetrical sibling competition, the mechanisms and adaptive
advantage of this strategy remains to be explored.

abstract: Thesis

abstract: Master of Science (MSc)

abstract:
Sentinels are vigilant animals that watch over foraging group members. While
sentinels has been reported in many animal species, minimal work has been done to
test for coordination of sentinel behaviour. I tested for coordination of sentinel behaviour
in Smooth-billed Anis and show that they do not coordinate sentinel bouts.
I also examined sex ratios of Smooth-billed Anis. Adaptive sex ratio allocation in
relation to hatching order has been suggested to reduce asymmetrical sibling competition
and increase offspring survival. Females may also bias sex ratios of their
offspring depending on their condition to maximize their fitness benefits. Here I
report a male bias in last hatched chicks and no significant influence of rainfall
(proxy for maternal condition) on brood sex ratios.


contributor:
Franek, Frantisek
Computer Science

abstract: Title: Java Error Correction Algorithm in the Framework of an Intelligent Tutoring System, Author: Edward R. Skyes, Location: Thode

abstract:
Intelligent Tutoring Systems (ITS) are, in many respects, very similar to human
tutors. Based on cognitive science and Artificial Intelligence (AI), ITS have proven their
significance in many disciplines. Currently, ITS can be found in core Mathematics,
Physics, and Language courses in hundreds of schools across Canada, the United States,
and various countries in Europe. ITS are growing in acceptance and popularity for
reasons including: i) increased student performance, ii) deepened cognitive development,
and iii) reduced time for student to acquire skills and knowledge.

Bloom (1984) showed that one-on-one human tutors could increase the average
student's performance to the ninety-eighth percentile in a standard classroom.
Furthermore, in order for students to reach their potential, individualized tutoring is a
necessity. Intelligent Tutoring Systems have demonstrated that student achievement is
1.0 standard deviation higher than typical classroom environments. Another benefit ITS
have is the speed of knowledge acquisition. Students learning from an ITS have
completed problems in one-third of the time compared to students in the control group.

This thesis focuses on the design and implementation of an error correction
algorithm in the specific context for use in an ITS for the Java programming language.
The Java Error Correction Algorithm (JECA) was designed to be used by first year
College and University students with little or no programming experience. JECA
attempts to determine the "intent" of the student's submission by rigorously analyzing the
student's code. Behind the scenes, JECA makes changes to the student's submission in
order to facilitate this analysis. However, once JECA determines the most reasonable
intent of the student, these changes are made known to the student. The results from
JECA are passed to the Java Intelligent Tutoring System (JITS) in the form of hints and
suggestions, which are then used for instructional purposes.

This thesis focuses on JECA, however, to ensure contextual relevance and
significance, the Java Intelligent Tutoring System is included. JITS is implemented using
advanced e-learning technologies and its multi-threaded distributed architecture makes
JITS scalable, robust and easy to maintain. JITS supports personalized student
development by tracking and modeling every student in the system. JITS is an online
website always available for students and requires only a browser and an internet
connection.

abstract: Thesis

abstract: Master of Science (MSc)


title: THE ROLE OF THE IRE1α PATHWAY IN VASCULAR STIFFENING AND FIBROSIS

contributor: Medical Sciences (Division of Physiology/Pharmacology)

subject:
Hypertension
Unfolded Protein Response
Endoplasmic Reticulum Stress
Vascular Stiffening
Fibrosis

abstract:
Background: Vascular stiffening develops with both hypertension and aging, and is a strong predictor of end-organ damage. Excessive deposition of collagen by vascular smooth muscle cells (VSMCs) can lead to decreased compliance of vessels such as the aorta. The IRE1α arm of the unfolded protein response is activated in cells with a secretory phenotype due to its role in augmenting protein folding capacity. We hypothesize that by a similar mechanism, VSMCs transitioning to a collagen-secreting phenotype in response to TGF-β1 require the activation of IRE1. Inhibition of this pathway is hypothesized to reduce collagen secretion and hence prevent the development of fibrosis in the aorta.
Methods: Collagen deposition by VSMCs in vitro was measured using immunoblotting and a Picrosirius Red-based colorimetric assay. Western blot and qRT-PCR were used to assess the expression of ER stress markers. Ex vivo culture of aortic rings was also performed to determine the effect of 4µ8c on TGF-β1-induced vascular stiffening. 12-14 week old male spontaneously hypertensive rats were divided into three treatment groups: 1) No treatment, 2) L-NAME (50 mg/L), and 3) L-NAME and the IRE1α inhibitor 4µ8c (2.5 mg/kg/day i.p.). Aortic compliance after 18 days of treatment was measured ex vivo using a wire myograph to construct tension-diameter curves.
Results: Inhibition of IRE1α endonuclease activity by 4µ8c reduced collagen production in VSMCs stimulated with TGF-β1 or Ang II. A decrease in the expression of the collagen-associated chaperones PDI, GRP78 and GRP94 was observed. Aortic rings treated with TGF-β1 developed vascular stiffening, which was improved by co-treatment with 4µ8c. SHRs treated with L-NAME for 18 days developed aortic stiffening, which was prevented by daily injections of 4µ8c.
Conclusions: Our data suggest that inhibition of the IRE1α pathway can reduce vascular stiffening and fibrosis by disrupting the collagen biosynthesis pathway in VSMCs.

abstract: Thesis

abstract: Master of Science (MSc)


title: Quantitative Susceptibility Mapping of Atherosclerosis in Carotid Arteries

contributor:
Haacke, E. Mark
Biomedical Engineering

subject:
Magnetic Resonance Imaging
Quantitative Susceptibility Mapping
Carotid Atherosclerosis

abstract:
Carotid atherosclerosis, one of the leading causes of ischemic stroke worldwide, can induce severe narrowing or even occlusion of the vessel, restricting blood flow to the brain and resulting in perfusion deficits. The plaque that has a high probability of undergoing rapid progression or future ruptures is defined as “vulnerable plaque”. Identifying vulnerable plaque is of great importance in clinical carotid atherosclerosis imaging. To date, a multi-contrast magnitude-based MR approach with blood suppression technique has been widely used to detect vulnerable plaque features. However, due to the limitations of magnitude-based methods, developing new MR techniques that have better sensitivity to hemorrhage and calcification is of great interest.

Quantitative Susceptibility Mapping (QSM) is a technique that utilizes the MR phase information and has been widely used for quantifying the tissue susceptibility in the brain. The susceptibility contrast is extremely sensitive to hemorrhage and calcium which makes QSM a potential tool for carotid plaque imaging to identify intraplaque hemorrhage (IPH) and calcification. However, existing QSM methods have not been successfully implemented in the neck due to several challenges. The presence of air/tissue interface, plaque that has high susceptibility, and fat surrounding the carotid arteries can cause severe phase aliasing and other problems that will induce errors in the resultant susceptibility maps.
To overcome these challenges and thus, develop a robust method for carotid QSM, a protocol that includes both data acquisition strategy and post-processing methods is proposed. For data acquisition, four echoes including two water/fat in-phase echoes and two water/fat out-of-phase echoes were collected. For data post-processing, temporal domain algorithm Catalytic Multiecho Phase Unwrapping Scheme (CAMPUS) was used to unwrap the phase images and local QSM was proposed. This protocol is able to properly unwrap the phase images even with the presence of high susceptibility plaque and eliminate the water/fat chemical shift effect in QSM reconstructions which will generate reliable susceptibility maps. From our results, the proposed QSM protocol has demonstrated the ability to generate reliable susceptibility maps and excellent sensitivity to IPH and calcification. Combining QSM with existing magnitude-based methods will lead to a major improvement in the diagnosis of carotid atherosclerosis.

abstract: Thesis

abstract: Master of Applied Science (MASc)


contributor:
Humphreys, Karen R.
Psychology

abstract: Title: Conversational Disfluencies as a Predictor of Attention Problems in Preschool, Author: Elizabeth Hart, Location: Thode

abstract:
Attention Deficit Hyperactivity Disorder (ADHD) is frequently comorbid with language
impairment. There is currently no detailed linguistic profile of children with ADHD. A
previous study (Redmond, 2004) found that in conversation, children with ADHD
produced more words per maze than typically developing controls, but did not determine
the specific disfluency driving the correlation. The present study examined the
conversational language, and measures of attention deficits, executive functioning and
spatial intelligence of a non-clinical community sample of 46 preschool-aged children.
The results replicated Redmond's finding and further indicated that attention deficits and
executive dysfunctioning were associated with the production of more long repairs and
restarts. The number of pauses was positively correlated with spatial abilities. Findings
suggest that a preschooler who produces many long repairs and restarts should be
monitored for possible attention deficits.

abstract: Thesis

abstract: Master of Science (MS)


contributor:
Vaillancourt, Tracy
Psychology

abstract: Title: Some Get Mad, Others Get Sad: the Mediating Role of Jealousy in Female Undergraduate Students' Experiences with Romantic Relational Aggression, Author: Steven Arnocky, Location: Thode

abstract:
Romantic relational aggression is a form of psychological abuse that is meant to
purposefully incite or induce insecurity about the relationship. It has been shown to be
associated with emotional problems such as increased anxiety and depression symptoms
as well as aggression, all of which may be manifestations of jealousy. The goal of this
study was to propose and test a theoretical model explaining the fundamental role that
jealousy plays in mutual romantic relational aggression in intimate partnerships using
structural equation modeling. Results indicated that romantic relational victimization is
predictive of possessiveness (an indicator of jealousy), which in tum was predictive of
aggression use and anxious and depressive symptoms. Model fit indices supported our
theory that in this manner, relational victimization serves as a form of jealousy induction,
and that the resulting jealousy experienced by the victim can manifest as reciprocal
relational aggression, depressive, or anxious symptoms.

abstract: Thesis

abstract: Master of Science (MS)


contributor:
Balakrishnan, Narayanaswami
Statistics

abstract: Title: Competing Causes of Failure for Weibull Lifetimes Under Type II Progressive Censoring, Author: Mallikarjuna R. Rettiganti, Location: Thode

abstract:
In life-testing experiments, specimens may fail due to more than one cause. Usually,
the researcher who is interested in the primary cause of failure, treats the other causes
of failure as censored data. In recent times, however, analysis is being done in the
presence of competing causes of failure. Also, censoring becomes inevitable since it
saves time and resources. In this project, we discuss inference for competing risks
under Type II progressive censoring for Weibull lifetimes. We have considered a
simple model where we assume equal shape parameters.

This report is organized into six chapters. In Chapter 1, the concepts of progressive
censoring and competing risks are introduced. The model is presented and then
described. Notations used throughout the project are also given. Maximum likelihood
equations are derived in Chapter 2 and the algorithm for solving them is also
presented. Different confidence intervals for the parameters are discussed in Chapter
3 and the simulation results comparing the probability coverages and the lengths
of the different confidence intervals are provided in Chapter 4. The performance of
these different intervals is illustrated using a real dataset in Chapter 5. Finally, in
Chapter 6, we provide a summary of the results and some extensions that may be
carried out in the future.

abstract: Thesis

abstract: Master of Science (MS)


title: MENTAL HEALTH, QUALITY OF LIFE AND LIFE EXPERIENCES OF GHANAIAN WOMEN LIVING WITH BREAST CANCER

contributor:
Shannon, Harry
Williams, Allison
Global Health

subject:
Breast Cancer
Quality of Life
Psychological Distress
Life Experiences
Ghana

abstract:
Background: The burden of breast cancer may contribute to elevated psychological distress. Conversely, distress may negatively impact the development, recurrence and diagnosis of cancer as it compromises the immune system and adherence to treatment, creating a vicious cycle. With the breast cancer fatality rate significantly higher in Sub-Saharan African women than in women living in higher income countries, further research is needed to limit the devastating impact of chronic diseases on this population.
Purpose: The aim of the study was to determine if Ghanaian breast cancer patients were more susceptible to higher psychological distress and lower quality of life than healthy Ghanaian women and how their lived experiences affect their mental health.
Method: Sixty-four breast cancer patients and 64 healthy participants were recruited to complete the Kessler Psychological Distress Scale and World Health Organization Quality of life-BREF scale. The life experiences of women living with breast cancer were assessed through semi-structured interviews.
Results: Breast cancer patients had higher psychological distress than the healthy women and also scored lower on the quality of life domains of physical health, psychological well-being and environment. The lived experiences of the breast cancer patients followed a similar journey from suspicion of ill-health to difficulty navigating the health system, feeling the effects of breast cancer and lastly, regaining confidence. Breast cancer had affected the women’s daily activities, health, female identity, roles and responsibilities. However, financial, emotional and social support, together with individual coping mechanisms such as religion and physical exercise, mitigated the impact of the breast disease.
Conclusion: Patient centered care approaches could ease the psychological distress of breast cancer patients. Finally, future research should investigate methods of improving the women’s psychological well-being, physical health and environment as it may positively impact the prognosis of Ghanaian breast cancer patients.

abstract: Thesis

abstract: Master of Science (MSc)


title: Modeling and adjoint sensitivity analysis of general anisotropic high frequency structures

contributor:
Bakr, Mohamed
Electrical and Computer Engineering

subject:
adjoint variable method
anisotropic material
sensitivity analysis
transmission line modeling
invisibility cloaking
optimization
numerical modeling

abstract:
We propose an efficient wideband theory for adjoint variable sensitivity analysis of problems with general anisotropic materials.  The method is formulated based on the transmission line numerical modeling technique.  The anisotropic material properties of potential interest are the full tensors of permittivity, permeability, electrical conductivity, magnetic resistivity, magnetoelectric coupling, and electromagnetic coupling.  The tensors may contain non-diagonal elements.  Our method estimates the gradients of the desired response with respect to all designable parameters using at most one extra simulation, regardless of their number.  In contrast, in the conventional sensitivity analysis method using central finite differences, the number of the required simulations scales linearly with the number of designable parameters.  The theory has been implemented for sensitivity analysis of the two and three-dimensional structures.  The available adjoint variable method (AVM) sensitivities enable the optimization-based design of anisotropic and dispersive anisotropic structures.
We apply our AVM technique to optimization-based wideband invisibility cloak design of arbitrary-shape objects.  Our method optimizes the voxel-by-voxel constitutive parameters of an anisotropic cloak.  This results in a large number of optimizable parameters.  The associated sensitivities of a wideband cloaking objective function are efficiently estimated using our anisotropic adjoint variable method technique.  A gradient-based optimization algorithm utilizes the available sensitivity information to iteratively minimize the visibility objective function and to determine the constitutive parameters of the optimal cloak.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: A Multi-objective Decision-Making Framework for Sustainable Urban Development

contributor:
Baetz, Brian
Civil Engineering

subject: MODM MADM Sustainable development

abstract:
Planning in the context of urban sustainability is very challenging as it requires simultaneous integration of a large number of conflicting objectives pertaining to economic, environmental and social dimensions. It also involves multiple stakeholders with opposing views, and a high level of uncertainty. In addition, the process should be transparent, participatory and understandable by all participants.
Existing literature has called for exploring new analytical methods to support decision-making for urban sustainability. This research introduces a structured decision support framework underpinned by Multi-objective Decision-Making (MODM) and Multi-attribute Decision Making (MADM). The framework provides systematic guidance to decision-making starting from problem structuring to generating a wide range of alternatives until the selection of the final solution.
The developed framework is tested in two different decision-making situations pertaining to real urban problems. In the first case study, the framework is examined in the situation where the decision-maker is available to interact with the planner at the design stage. The framework is used to find a sustainable distribution of healthcare centers taking into consideration conflicting objectives including cost, efficiency of service and accessibility. The optimal solution is reached through an interactive process with stakeholders.
In the second case study, the framework is examined in the situation where the decision-maker is unavailable for interaction at the design stage. The framework is used to develop planning scenarios for transit-oriented development (TOD) around a transit station. The optimal intensification of land use and land use mix is achieved taking into consideration the conflicting objectives of various stakeholders. Large number of non-dominated alternative solutions has been generated. An interactive tool has been developed by which the stakeholders can identify the alternative that best reflects their preference.
The quality of the outputs for both case studies has shown that the developed planning methodology outperforms conventional approaches. The developed framework has proved to be a flexible and practical approach to assist decision-making in the context of urban sustainability

abstract: Dissertation

abstract: Doctor of Philosophy (PhD)

abstract: Achieving sustainable urban development is a very challenging task for planners.  It requires simultaneous integration of a large number of conflicting objectives pertaining to economic, environmental and social dimensions. It also involves multiple stakeholders with opposing views, and a high level of uncertainty.  In addition, the decision-making process should be transparent, participatory and understandable by all participants. This research introduces a decision-support framework, underpinned by mathematical modeling techniques, to assist in achieving sustainable solutions for urban development problems.  The framework is  examined through two case studies. First, it is used to find a sustainable distribution of healthcare centers taking into consideration conflicting objectives including cost, efficiency of service and accessibility. Second, the framework is used to develop planning scenarios for transit-oriented development (TOD) around a transit station.  The developed framework has proved to be a flexible and practical approach to assist decision-making in the context of urban sustainability