title: The Concepts Of Deity Of Rāmānuja And Charles Hartshorne Compared

contributor:
Robertson, J.C.
Religion

subject: Religion Religion

abstract: Doctor of Philosophy (PhD)


title: Associative Basis of UCS Preexposure in Excitatory and Inhibitory Rabbit Eyelid Conditioning

contributor:
Siegel, Shepard
Psychology

subject: Psychology Psychology

abstract:
Exposure to the unconditional stimulus (UCS) prior to its pairing with the conditional stimulus (CS) retards subsequent excitatory conditional response (CR) acquisition in a variety of Pavlovian conditioning preparations. Traditionally, this UCS preexposure effect has been attributed to nonassociative, adaptational- like processes. Recently, however, it has been suggested that associative processes, involving the formation of an association between the UCS and stimuli of the context in which the UCS is preexposed, play a crucial role in the effects of UCS exposure. The experiments Ieported in this thesis were designed to determine whether conditioning to contextual stimuli may, in fact, mediate the effects of UCS preexposure in rabbit eyelid conditioning.

The results of Experiment demonstrate that the UCS preexposure effect in excitatory eyelid conditioning is evident only if CS-UCS pairings are administered in the same context as UCS preexposure. Thus, mere repeated exposure to the UCS is not sufficient for production of the UCS preexposure effect as would be expected on the basis of any entirely nonassociative account. Experiments 2 and 3 demonstrate that the detrimental effect of UCS preexposure on subsequent excitatory CR acquisition may be attenuated by associative manipulations of contextual stimuli of the preexposure environment. In Expeliment 2, contextual stimuli were "latently inhibited" (a procedure known to reduce conditioning to stimuli) prior to the start of UCS preexposure. This procedure, which should have had the effect of reducing conditioning to contextual stimuli, attenuated the UCS preexposure effect. In Experiment 3, contextual stimuli were extinguished (a procedure known to weaken established conditioning). This procedure also attenuated the UCS preexposure effect. The-results of Experiment 1, 2, and 3 establish that associative processes involving contextual stimuli are crucially involved in the UCS preexposure effect in excitatory eyelid conditioning.

In Experiment 4, the effect of UCS preexposure on inhibitory eyelid conditioning was examined. UCS preexposure facilitated inhibitory learning, an effect that would be expected if conditioning to contextual stimuli occurs during UCS preexposure, but not if UCS preexposure involves only nonassociative processes.

The results were discussed in relation to various theoretical accounts of UCS preexposure. Although other factors may be involved, the results of the present thesis demonstrate an associative basis for the effects of UCS preexposure in rabbit eyelid conditioning. The role of conditioning to contextual stimuli in other preconditioning stimulus exposure procedures (e.g., latent inhibition, truly random CS/UCS presentations), and in effects involving postconditioning UCS exposure (reinstatement of fear) was also discussed. In conclusion, it is argued that conditioning to contextual stimuli occurs in a variety of stimulus exposure procedures, and that such conditioning may be importantly involved in mediating a variety of learning phenomena.

abstract: Doctor of Philosophy (PhD)


title: Behavioral and Adrenocortical Responses of Rats with Fornix Lesions to Changes in Environmental Stimulation

contributor:
Black, A. H.
Philosophy

subject: Philosophy Philosophy

abstract: " First two papers came out black while the other ones are fine".

abstract:
The behavior of animals with hippocampal damage differs from that of normal animals across a variety of behavioral tasks. However, the indices of learning and performance used to assess the effects of hippocampal damage are limited in information content, and are easily subsumed by several current theories of hippocampal funct ion. The approach taken in the present series of experiments was to utilize tasks that consistently result in behavioral deficits in animals with hippocampal damage, but to increase the amount of information. The experiments analyzed the response of rats with total fornix lesions to the transition from acquisition to extinction of a response. Detailed observations of the behavior and measurement of corticosterone levels allowed a more complete picture of the hippocampal deficit to emerge.

Experiment 1 examined acquisition and extinction of an operant lever press response in a standard operant chamber. Fornix lesioned rats made fewer responses during acquisition and had increased resistance to extinction. Detailed analysis revealed many other differences in the behavior of control and lesioned rats. Control rats reacted to the transition to extinction with decreased frequency of bouts of food related behaviors, increased bout durations of all behaviors, changed topography of lever presses from acquisition type presses to biting responses, changed sequential organization of behaviors, and behaviors labelled as emotional. Control rats also responded to the transition with increased plasma corticosterone levels, an increase that was negatively correlated with response burst duration and amount of biting, and positively related to the maintenance of acquisition responses. Fornix lesioned rats exhibited more random behavioral organization, in both acquisition and extinction. Following the transitiun to extinction, lesioned rats did not exhibit the behavioral flexihility, corticosterone increases, or behaviorcorticosterone relationships exhibited by control rats.

Experiment 2 maintained the same task requirements but in a large, enriched environrnent. Less efficient behavioral organization resulted in lesioned rats again receiving fewer reinforcements during acquisition. Both grous extinguishnd faster tn the large enriched environment than in Experiment 1, but lesioned rats maintained food related behaviors longer than controls. Lesioned rats exhibited only acquisition type responses interspersed with short trips away from the lever and food cup. Controls exhibted two modes of response interspersed with short. ion trips away. During trips away, the groups differed in their interactions with objects in the environment in terms of frequency, duration, intensity and temporal and sequential organizations.

Experiment 3 examined exploratory behavior patterns during initial exposure to the experimental environment of Experiment 2. The groups again differed in frequency, quality and organization of their interactions with objects in the environment. Control rat exploratory patterns were similar to those during extinction, but lesioned rat patterns differed.

Experiment 4 examined the response of lesioned and control rats to environmental change in a simple appetitive consummatory task. After being allowed to eat, the rat's consummatory response was blocked while 'the cues controlling behavior were maintained. The groups differed in the frequency, duration and organization of their behavior. Controls responded to the change with increased corticosterone and altered behavioral strategies while lesioned rats showed neither.

Experiments 4, 5 and 6 examined alternative explanations of the differences in corticosterone response profiles of control and lesioned rats during acquisition and extinction. These differences appear not to have resulted from 1) differences in conditioning to the sampling procedure, 2) a general attenuation of responsiveness in lesioned rats, or 3) differences in response to the novel aspects of the testing environment.

The detailed analysis of behavior suggests that fornix lesioned rats differ from controls in the organization of behavior and in response to changes in environmental demands. The results are used to address contradictory issues in current theories of hippocampal function.

abstract: Doctor of Philosophy (PhD)


title: Sulfur Passivation of III-V Semiconductor Nanowires

contributor:
LaPierre, Ray R.
Adrian Kitai, Rafael Kleiman
Engineering Physics

subject:
Nanowire
Passivation
III-V semiconductor
Sulfur
Photoluminescence
Solar Cell
Engineering Physics
Engineering Physics

abstract:
An ammonium polysulfide (NH4)2Sx solution was optimized through a series of experiments to be used for surface passivation of III-V nanowires . The effectiveness of sulfur passivation was investigated by measuring the photoluminescence from p-InP nanowires before and after passivation. The optimized parameters included solvent type, molarity and passivation time. According to the experiments, passivation of nanowires in 0.5 M solution diluted in isopropyl alcohol for 5 min produced the maximum photoluminescence improvement. It was also demonstrated that the whole surface passivation of vertical nanowires in ensemble samples caused a 40 times increase in the photoluminescence intensity while top surface passivation of individual nanowires resulted in a 20 times increase of photoluminescence intensity. A model was developed to calculate the photoluminescence from single nanowires under different surface recombination and surface potential. The model showed that the 40 times increase in the photoluminescence is mainly due to the reduction of surface state density from 1012 cm-2 before passivation to 5×1010 cm-2 after passivation.

The effect of sulfur passivation on core-shell p-n junction GaAs nanowire solar cells has been investigated. The relative cell efficiency increased by 19% after passivation.

abstract: Doctor of Philosophy (PhD)


title: NONINVASIVE IMAGING OF LUNG PATHOLOGY AND PHYSIOLOGY IN MURINE MODELS OF ASTHMA AND COPD

contributor: Medical Sciences (Molecular Virology and Immunology Program)

subject:
CT
SPECT
V/Q
Asthma
COPD
Noninvasive Imaging
Allergy and Immunology
Circulatory and Respiratory Physiology
Disease Modeling
Immune System Diseases
Medical Biophysics
Pathology
Physiological Processes
Radiology
Respiratory Tract Diseases
Allergy and Immunology

abstract:
Obstructive lung diseases limit airflow and gas exchange and have a major impact on a patient’s long-term health. Asthma and chronic obstructive pulmonary disease (COPD) are the most prevalent obstructive lung diseases and represent a major burden on healthcare systems worldwide. It is now accepted that the pathologies associated with these diseases are heterogeneous in nature, and as the function of the lung is determined by its three-dimensional structure, methods to volumetrically evaluate the lung are important tools in furthering the study of these pathologies.

Three-dimensional imaging methodologies, such as computed tomography (CT) and single photon emission computed tomography (SPECT), are used clinically in the diagnosis of lung disease, but results are not commonly quantified. In addition, asthma and COPD develop slowly over time and diagnosis normally takes place after the underlying pathologies are well established. Experimental models in small animals, such as rats and mice, allow for the study of disease pathogenesis in a controlled setting and development of quantitative imaging practices for these models provides translational tools for relating results back to the clinic.

In this thesis, CT densitometry and ventilation/perfusion (V/Q) SPECT are explored as methods to investigate models of asthma and COPD. CT densitometry is shown to be capable of quantifying allergic inflammation in an asthma model but is of less use in a model of COPD, predominantly due to the relative amounts of inflammation present. However, V/Q imaging is shown to be quite sensitive to the effects of cigarette smoke in a model of COPD and has been used to better understand how pathologies associated with COPD contribute to gas exchange limitation in the lung.

The models, imaging techniques, and analysis methods described in this work provide insight into chronic obstructive lung disease and allow for future investigations into how pathologies effect gas exchange. Further, the characterization of the models described in this thesis allows for drug efficacy studies to be performed, both on established and novel treatments. Future research into asthma and COPD will benefit further from the use of threedimensional imaging methodologies because they provide volumetric information on structure and function and can act as a translational bridge between clinical disease and preclinical animal models.

abstract: Doctor of Philosophy (Medical Science)


title: The Search for Correlated Rotation in Sterically Hindered, Multi-n-Bladed CnArnx± (n = 5, 6 and 7) Propellers: From Models to Molecules

contributor:
McGlinchey, M. J.
Chemistry

subject: Chemistry Chemistry

abstract:
Crystallographically independent structures possessing persubstituted cyclopentadiene (C5Ar4X, C5Ar4X2) and -dienyl (C5Ar5) moieties were retrieved from the Cambridge Structural Database, and the torsional angles of selected diaryl frames presented in the form of conformational plots. Semi-empirical (AM1) calculations of the corresponding potential energy surfaces reproduced the conformational trends observed in the solid state. By the Structure Correlation principle, the internal oscillations of nearest (1,2-) and next-nearest (1,3-) aryl rings in all pseudo-propeller subunits were found to be only partially correlated. These solid-state data sets, in combination with energetic predictions of the molecules C5Ph5- 1.18, C5Ph4H- 2.1, C4Ph4C=O 1.53 and C4Ph4CH2 2.2, indicate that a delayed n-ring-flip (where n = 5, X = 0-2 in CnArn-mXm), which is otherwise unobservable via NMR spectroscopic methods, is the threshold rotational mechanism in propeller systems of this type.

The least linear motion path associated with the reorientation of a single terminal phenyl group in the parent C6Ph6, 1.125, has been mapped with the use of semi-empirical molecular orbital, ab initio Hartree Fock and hybrid density functional theory, in combination with numerous basis sets (STO-3G to cc-pVDZ). The superior energetic performance of the less common yet appropriately balanced B3PW91/6-31G(d,p) model chemistry compares favourable with the AM1 Hamiltonian in a conformational analysis of 1.125. To evaluate the energetic and structural implications of replacing a phenyl group with different sterically anisotropic fragments, a series of polyarylated benzenes of the formula C6Ar5X have been synthesized by the Diels-Alder cycloaddition of the appropriate diarylacetylenes to tetraaylcyclopentadienones and subsequent extrusion of carbon monoxide. The X-ray structure determinations of perphenylferrocene (3.19), 1-(pentaphenylphenyl)benzene-2-phenylacetylene (3.26), 1-(1,2-Z-dibromo-2-phenyl)vinyl-2,3,4,5,6-pentaphenylbezene (3.35) and 1-(2-born-2,3-en-2-yl)-2,3,4,5,6-pentaphenylbenzene (3.40) are correlated with the NMR measurements of rotational isomerism in solution.

The solid-state characterization of the heptaphenylcycloheptatrienyl cation, C7Ph7+, 1.139, in [C7Ph7+][CF3CO2]2CF3CO2H, represents the first nondisordered structure solution of a free tropylium cation and ends a formidable, three decade long crystallographic quest. The conformational features of 1.139 and other polysubstituted C7R7-mHm (where 4 ≤ m ≥ 0, R = Ph, Me) derivatives have been rationalized by semi-empirical (AM1) calculations, and reveal a compromise between steric congestion and the fractional loss in aromaticity as the central ring distorts from planarity. A correlation of the 13C-NMR chemical shift with the computed electron density for CnHnx± and CnArnx± species (n = 3 to 7) yields a proportionality factor of approximately 21 and 22 ppm per extra 0.1 electron at the central ring carbons, respectively. The steric capacity of the Diels-Alder cycloaddition reaction has been corroborated by the synthesis of C7Ph6FcH, 4.38, for which the structural perturbations induced by the ferrocenyl fragment were quantified on both static (X-ray crystallography) and dynamic (variable-temperature NMR) levels. Subsequent attempts to study π-delocalization effects in the α-stabilized organometallic cation, [C7Ph6Fc]+, were thwarted by the apparent inaccessibility of the methine hydrogen in 4.38 by appropriate reagents. An X-ray diffraction analysis confirmed the formation of [C7Ph6FcH]+ [SbCl6]-, 4.44, via an electron abstraction at the metal center.

abstract: Doctor of Philosophy (PhD)


title: Optimal Server Allocation in Zero-Buffer Tandem Queues

contributor:
Down, Douglas G.
Computing and Software

subject:
tandem queues
zero buffer
server allocation
flexible server
Applied Mathematics
Computer Sciences
Applied Mathematics

abstract: We study the server allocation problem for tandem queues in the absence of intermediate buffer space. Servers are assumed to be homogeneous and non-collaborative. We provide policies to maximize the throughput. We break down our work into four stages. First, we assume that all servers are dedicated. We propose an allocation algorithm that assigns servers to stations based on the mean service times and the current number of servers assigned to each station. The algorithm is proposed for stations with exponentially distributed service times, but where the service rate at each station may be different. We further study the impact on the proposed allocation method of including service time distributions with different coecients of variation. Second, we consider tandem queues with both dedicated and flexible servers. We examine policies to dynamically assign flexible servers. When there is one flexible server and two stations each with a dedicated server, we completely characterize the optimal policy. We use the insights gained from applying the Policy Iteration algorithm on systems with three, four, and five stations to devise heuristics for systems of arbitrary size. Third, we study cases where flexibility is constrained such that flexible servers can only service two adjacent stations. We provide optimal policies for tandem queues with three and four stations and compare them with optimal policies for corresponding non-constrained cases. Fourth, we consider two parallel tandem queues with both dedicated servers and vertical flexible servers - servers that can move between corresponding stations of the two tandem queues. The workload allocations are the same for each line and each vertical flexible server moves only between two corresponding stations. We examine policies for dynamic allocation of these vertical flexible servers. When each tandem queue has two stations, each station possesses a dedicated server, and a vertical flexible server exists for each pair of stations, we specify the optimal policy. For cases with more than two stations, heuristic assignments are proposed. We also analyze the throughput improvement gained from adding flexible servers within a tandem queue or between two parallel tandem queues. Numerical results are used to verify the heuristics provided in each of the stages.

abstract: Doctor of Philosophy (PhD)


title: FRAGILITY CURVES FOR RESIDENTIAL BUILDINGS IN DEVELOPING COUNTRIES: A CASE STUDY ON NON-ENGINEERED UNREINFORCED MASONRY HOMES IN BANTUL, INDONESIA

contributor:
El-Dakhakhni, Wael
Tait, Michael J.
Civil Engineering

subject:
fragility curves
empirical
developing countries
non-engineered masonry
seismic risk assessment
shakemaps
Structural Engineering
Structural Engineering

abstract:
Developing countries typically suffer far greater than developed countries as a result of earthquakes. Poor socioeconomic conditions often lead to poorly constructed homes that are vulnerable to damage during earthquakes. Literature review in this study highlights the lack of existing fragility curves for buildings in developing countries. Furthermore, fragility curves derived using empirical data are almost nonexistent due to the scarcity of post-earthquake damage data and insufficient ground motion recordings in developing countries. Therefore, this research proposes a methodology for developing empirical fragility curves using ground motion data in the form of USGS ShakeMaps.

The methodology has been applied to a case study consisting of damage data collected in Bantul Regency, Indonesia in the aftermath of the May 2006 Yogyakarta earthquake in Indonesia. Fragility curves for non-engineered single-storey unreinforced masonry (URM) homes have been derived using the damage dataset for three ground motion parameters; peak ground acceleration (PGA), peak ground velocity (PGV), and pseudo-spectral acceleration (PSA). The fragility curves indicate the high seismic vulnerability of non-engineered URM homes in developing countries. There is a probability of 80% that a seismic event with a PGA of only 0.1g will induce significant cracking of the walls and reduction in the load carrying capacity of a URM home, resulting in moderate damage or collapse. Fragility curves as a function of PGA and PSA were found to reasonably represent the damage data; however, fits for several PGV fragility curves could not be obtained. The case study illustrated the extension of ShakeMaps to fragility curves, and the derived fragility curves supplement to the limited collection of empirical fragility curves for developing countries. Finally, a comparison with an existing fragility study highlights the significant influence of the derivation method used on the fragility curves. The diversity in construction techniques and material quality in developing countries, particularly for non-engineered cannot be sufficiently represented through simplified or idealized analytical models. Therefore, the empirical method is considered to be the most suitable method for deriving fragility curves for structures in developing countries.

abstract: Master of Applied Science (MASc)


title: Design of an Adaptive Cruise Control Model for Hybrid Systems Fault Diagnosis

contributor:
Wassyng, Alan
Lawford, Mark
Douglas Down, Ned Nedialkov
Computing and Software

subject:
Hybrid Systems
Adaptive Cruise Control
Fault Diagnosis
Controls and Control Theory
Software Engineering
Controls and Control Theory

abstract:
Driver Assistance Systems like Adaptive Cruise Control (ACC) can help prevent accidents by reducing the workload on the driver. However, this can only be accomplished if the driver can rely on the system to perform safely even in the presence of faults.

In this thesis we develop an Adaptive Cruise Control model that will be used to investigate Hybrid Systems Fault Diagnosis techniques. System Identification is performed upon an electric motor to obtain its transfer function. This electric motor belongs to a 1/10th scale RC car that is being used as part of a test bench for the Adaptive Cruise Control system. The identified model is then used to design a hybrid controller which will switch between a set of LQR controllers to create an example Adaptive Cruise Controller. The model of the controller is then used to generate fixed point code for implementation on the testbed and validation against the model controller. Finally a detailed hazard analysis of the resulting system is performed using Leveson's STPA.

abstract: Master of Applied Science (MASc)


title: CONCENTRATOR PHOTOVOLTAIC SYSTEM DESIGN USING OFF-ANGLE TRACKING

contributor:
Kleiman, Rafael
Engineering Physics

subject:
concentrator
photovoltaic
optics
solar
nonimaging
Energy Systems
Energy Systems

abstract: This thesis will discuss a novel method of tracking the Sun. An essential aspect of the method is to rotate a polar aligned single axis tracker such that the angle between the direction of the Sun and the normal of the module remains at a constant angle of 23.44 degrees or a few degrees more. The rotational symmetry that arises from this circumstance enables seasonal tracking to occur inside the module whilst maintaining efficient concentration. Several possible optical designs and a preferred optical design are presented as a way of implementing the tracking method. The tracking method is also open to a plethora of different concentrator photovoltaic system designs which may be integrated onto rooftops more effectively than conventional dual axis tracking systems.

abstract: Master of Applied Science (MASc)


title: A Poly-N-isopropylacrylamide Based Hydrogel as a Novel Material for Vitreous Replacement

contributor:
Sheardown, Heather
Chemical Engineering

subject: Biomaterials Biomaterials

abstract:
Although improvements in vitreous replacement technologies have lead to more desirable outcomes in patients with vision problems such as retinal detachment and vitreous hemorrhage, there remain a number of issues with current approaches. Many common therapies are limited to specific cases, or require extensive post-operative positioning, follow-up, and even secondary surgery for removal.

Thermally responsive materials composed of N-isopropylacrylamide, N-acryloxysuccinimide, and poly(ethylene glycol) were obtained through free-radical polymerization and were examined for the potential for use as artificial vitreous replacements. While in solution these materials were capable of transitioning from free-flowing liquids at room temperature to viscous solutions at physiological temperatures. Solutions of these materials were shown to have refractive indices similar to currently used vitreous replacements and gel-like mechanical properties at 37oC. Optical transparency studies were performed and most samples displayed adequate transmittance values in the visible spectrum. Co-monomer content and molecular weight were found to have an effect on the temperature of the phase transition, as well as the transparency and cellular compatibility of the solutions at 37oC.

While the materials studied require further optimization, these results suggest that poly(N-isopropylacrylamide) based polymers may have potential for use in vitreous replacement therapies

abstract: Master of Applied Science (MASc)


title: SUFFERING IN SILENCE? THE EFFECTS OF THE STIGMATIZATION OF MENTAL ILLNESS ON LIFE SATISFACTION

contributor:
Schormans, Ann Fudge
Greene, Saara
Social Work

subject:
mental illness
stigma
life satisfaction
selective disclosure
performing
resiliency
recovery
coping mechanisms
Cognitive Behavioral Therapy
Mental Disorders
Psychiatric and Mental Health
Social Work
Cognitive Behavioral Therapy

abstract:
The term ‘stigma’ is formally defined as the assignment of negative perceptions to an individual because of perceived difference from the population at large (The Free Online Dictionary by Farlex). Stigma, pervasive on a micro, mezzo and macro level serves to devalue individuals who have been diagnosed with mental illness and the support systems that are designed to assist them. Although efforts have been made in public awareness campaigns to reduce the stigma associated with mental illness, stigma continues to limit opportunities and restrain individuals from living full and enriching lives. Many individuals “suffer in silence” often resorting to maladaptive coping mechanisms to manage symptoms.

The purpose of this study was to uncover the short term and long term impact of stigma from the perspective of those who are labelled with mental illness in order to gain a deeper and more accurate understanding of the effects of such on life satisfaction. Existing literature suggests that the result of anticipated and experienced stigma can affect individuals in multiple ways: diminished self-esteem, self-efficacy, and self-worth; social withdrawal; identity ambivalence; secrecy and reduced opportunities (employment, housing, income).

This research utilized qualitative semi-structured interviews and photo elicitation to gain an understanding of experienced and anticipated stigma as perceived by those with mental illness. Theoretically, the study was influenced by the modified labelling theory which posits that social and internalized stigma associated with mental illness is a societal creation in that its’ development exists as a result of disapproving social attitudes about mental illness. Eight individuals with various diagnosed mental disorders participated in the study. The findings suggest that for each of the participants in this study, initial dealings with the mental health care system and its’ components are likely to impact individuals negatively but once effective treatment, medication stabilization and a good practitioner are found, the experience becomes positive and empowering to individuals. Regardless of the level to which internalized stigma exists, all participants engaged in acts of secrecy, withdrawal, passing and selective disclosure adversely affecting life satisfaction. The implications for practice include recognizing the structural factors that influence clients’ internalization of stigma which likely contributes to feelings of empowerment and control over ones’ life. Revealing mental health status to others may be beneficial in contributing to an improved quality of life satisfaction.

abstract: Master of Social Work (MSW)


title: The effects of aging on visual contour and shape perception

contributor:
Bennett, Patrick J.
Sekuler, Allison B.
Christensen, Bruce
Psychology

subject:
aging
contour integration
vision
perception
shape
orientation
older adults
integration
noise
Cognition and Perception
Developmental Psychology
Cognition and Perception

abstract:
Human vision has an incredible ability to translate light reaching the retinae into a coherent, three-dimensional representation of the outside world in a fraction of a second. Much research has been devoted to understanding how local orientation information is integrated to form global contours and shapes -– a crucial step in visual processing. This dissertation describes experiments examining how contour and shape perception are affected in healthy aging.

Chapter 2 examined contour grouping at low contrast and in the absence of distracters. Unlike younger subjects, older subjects did not benefit from co-alignment of local orientations with the contour’s outline, suggesting that grouping by orientation co-alignment is impaired in older age in low contrast. Chapters 3 and 4 examined the effects of aging on the ability to detect and discriminate high-contrast contours embedded in a dense field of distracters, as real life situations often require detecting objects among clutter, such as a snake hiding among tall grass. Results showed that older adults require significantly more time to discriminate contours in clutter, especially for less salient contours. Moreover, increasing the relative density of background clutter had a greater detrimental effect on older, compared to younger, subjects. However, aging did not seem to affect the ability to group contours across a range of spatial distances, or the sensitivity of contour integration to orientation misalignment. Lastly, Chapter 5 examined the influence of local orientation information on the perception of a contour's shape. Results revealed that older and younger subjects perceived the shape of a sampled contour in the same way, even when the contour's orientation and position information were in conflict. These findings indicated that the integration of orientation and position information in shape perception does not change with age.

abstract: Doctor of Philosophy (PhD)


title: THE HISTORICAL JESUS AND THE JOHANNINE APOSYNAGŌGOS PASSAGES

contributor:
Runesson, Anders
Westerholm, Stephen
Schuller, Eileen
Religious Studies

subject: historical Jesus; Gospel of John; synagogue

subject: Biblical Studies

subject: Biblical Studies

abstract: This study will critically evaluate the dominant framework through which the Johannine aposynagōgos passages (John 9:22, 12:42, 16:2) are read. This dominant framework, which understands these passages as allegorically encoding the history of a putative Johannine community some forty to fifty years after Jesus’ lifetime, will be judged exegetically and historically implausible. An alternative reading of the passages will be developed, grounded in a philosophy of history derived from the critical realist epistemology developed by Bernard Lonergan and introduced into New Testament studies by Ben F. Meyer. It will be argued that these passages are historically plausible and that the Gospel author intended factuality and was plausibly knowledgeable on the matter. Consequently, it will be argued that a positive judgment of historicity can be assigned to these passages.

abstract: Doctor of Philosophy (PhD)


title: PARALLEL IMAGE PROCESSING FOR HIGH CONTENT SCREENING DATA

contributor:
Fang, Qiyin
M. Jamal Deen, David W. Andrews
Jeremic, Aleksandar
Biomedical Engineering

subject: Parallel Computing

subject: Image Processing

subject: Cell Imaging

subject: High Content Screening

subject: Threshold Adjacency Statistics

subject: Bioimaging and biomedical optics

subject: Biomedical

subject: Computer and Systems Architecture

subject: Molecular, cellular, and tissue engineering

subject: Bioimaging and biomedical optics

abstract: High-content screening (HCS) produces an immense amount of data, often on the scale of Terabytes. This requires considerable processing power resulting in long analysis time. As a result, HCS with a single-core processor system is an inefficient option because it takes a huge amount of time, storage and processing power. The situation is even worse because most of the image processing software is developed in high-level languages which make customization, flexibility and multi-processing features very challenging. Therefore, the goal of the project is to develop a multithreading model in C language. This model will be used to extract subcellular localization features, such as threshold adjacency statistics (TAS) from the HCS data. The first step of the research was to identify an appropriate dye for use in staining the MCF-7 cell line. The cell line has been treated with staurosporin kinase inhibitor, which can provide important physiological and morphological imaging information. The process of identifying a suitable dye involves treating cells with different dye options, capturing the fluorescent images of the treated cells with the Opera microscope, and analyzing the imaging properties of the stained cells. Several dyes were tested, and the most suitable dye to stain the cellular membrane was determined to be Di4-Anepps. The second part of the thesis was to design and develop a parallel program in C that can extract TAS features from the stained cellular images. The program reads the input cell images captured by Opera microscopes, converts it to TIFF format from the proprietary Opera format, identifies the region-of-interest contours of each cell, and computes the TAS features. A significant increase in speed in the order of four fold was obtained using the customized program. Different scalability tests using the developed software were compared against software developed in Acapella scripting language. The result of the test shows that the computational time is proportional to number of cells in the image and is inversely proportional to number of cores in a processor.

abstract: Master of Applied Science (MASc)


title: Investigation of Interface, Defects, and Growth of GaSb/Si Heteroepitaxial Films using Aberration-Corrected Scanning Transmission Electron Microscopy

contributor:
Botton, Gianluigi
John S. Preston, Jeffrey J. Hoyt
Materials Science and Engineering

subject: GaSb/Si

subject: Interface

subject: Defects

subject: Heteroepitaxy

subject: Abserration-corrected Scanning Transmission Electron Microscopy

subject: HAADF-STEM

abstract:
Heteroepitaxial films of group III-antimonide-based semiconductor compounds on Si are amongst the most appealing candidates for solar applications because of the well-established Si platform and also for offering band-gap energies beyond the silicon road map. Nonetheless, high lattice mismatch between GaSb and Si as well as ambiguous nucleation of GaSb on Si are major drawbacks in manufacturing of heteroepitaxial GaSb/Si films because they can generate various defects in films. Atomic-level detection of these defects and delving into their origin, orientation, distribution, propagation, and interaction with each other will therefore provide an insight into inhibiting their formation or reducing their severity. State-of-the-art aberration-corrected transmission electron microscopes have marked a new era in the investigation of interfaces and defects. With sub-angstrom electron probes in scanning transmission electron microscopes, it is possible to pinpoint the individual atomic columns at interfaces and defects.

In this thesis, GaSb epilayers grown with molecular beam epitaxy on Si substrates were studied through aberration-corrected scanning transmission electron microscopy. The strain-relief mechanism of the epitaxial GaSb through formation of interfacial misfit dislocations was investigated and the strain distribution in the vicinity of dislocation cores as well as epitaxial layer was analyzed. The specific atomic-number dependent contrast mechanism of the high-angle annular dark-field technique enabled the unprecedented direct observation of anti-phase boundaries, the extended defects of highest interest in polar-on-nonpolar growths. This observation unraveled the ambiguity of nucleation of GaSb at interface regardless of preferential deposition of atomic species during growth procedure. The growth of GaSb at the initial stage of deposition was further investigated to understand the role of an AlSb buffer layer and growth mechanism of GaSb precisely. This investigation showed that AlSb and GaSb epilayers occur by Volmer-Weber growth mode and AlSb islands provide energetically favorable nucleation sites for GaSb film. Furthermore, taking advantage of atomic-resolution detection capability of high-angle annular dark-field in scanning transmission electron microscopy a novel mechanism of strain relief through multiple twining resulting in a lattice-registered growth of GaSb on Si(211) was elucidated. This contribution demonstrates that aberration-corrected scanning transmission electron microscopy provides profound insight into the polar-on-nonpolar growth which can be exploited to suppress the formation of structural defects.

abstract: Doctor of Philosophy (PhD)


title: Studies on the Homogeneous Nucleation of Crystalline Solids From Lyotropic Liquid Crystalline Solutions

contributor:
Dr. O. E. Hileman, Jr.
Chemistry

subject: Chemistry Chemistry

abstract:
The results of a study on the homogeneous nucleation of liquid crystalline solutions are reported.

We report the synthesis and some properties of four new esters of sulfoacetic acid and note the observation of the liquid crystalline properties of their aqueous solutions. The existence of these mesophases is interpreted in terms of the micelle structures offerred elsewhere for the similar case of sulfonic acid soap solutions. Also the metastability of some mesophase transitions is reported.

Some significant nucleation parameters are derived from the application of classical nucleation theory to the liquid crystal-solid phase transition. Discrepancies between these values and the literature results for other compounds are interpreted in terms of the extensive pre-nucleation ordering in the liquid phase.

abstract: Doctor of Philosophy (PhD)


title: Noise Characterization and Modeling of MOSFETs for RF IC Applications

contributor:
Deen, Jamal M.
Electrical Engineering

subject:
Electrical and Computer Engineering
Electrical and Computer Engineering

abstract:
This thesis develops a systematic and self-consistent framework for the RF noise characterization, modeling and simulation of deep sub-micron MOSFETs. The techniques and procedures developed in this thesis are general and can be applied to the high-frequency noise characterization of any active device. In general, there are five topics presented in this research work. First, a systematic calculation method that can directly calculate the noise parameters - minimum noise figure NFmin, equivalent noise resistance Rn, optimized source resistance Ropt and reactance Xopt - of an active device using matrix computation is presented. This method is general and can calculate the noise parameters of any noisy two-port network including correlated noise sources.

Second, a new de-embedding procedure based on a cascade configuration to remove the parasitic effects of the probe pads and the metal connections from the measured noise and s-parameters is developed. Two "THRU" dummy structures are proposed in the new de-embedding procedure and no equivalent circuit models for the probe pads and the interconnections are required. From theory, it has no frequency limitation (or it is valid to the frequency at which the discontinuity effect has to be taken into account) and works for any geometry of interconnection designed without introducing more dummy structures.

Third, two extraction methods to obtain the spectral densities of the channel noise, induced gate noise and their noise correlation from the intrinsic noise parameters as a function of frequency and bias condition are presented. The extracted noise spectral densities of desired noise sources will serve as a direct target for the verification of any proposed noise model developed.

Fourth, new physics-based channel noise models to predict the channel noise, induced gate noise and their noise correlation are developed and verified with the extracted noise sources. The impact of the channel-length modulation (CLM) effect, the hot electron effect, and the velocity saturation effect on the desired noise sources in the deep sub-micron MOSFETs are discussed in detail.

Lastly, the design strategies of a low noise amplifier based on the developed noise models and extracted noise information are presented as a guide line to choose the device size and bias condition of the transistors. The impact of the model accuracy on the simulated noise performance of a two stage low noise amplifier is also presented.

abstract: Doctor of Philosophy (PhD)


title: Using Population Survey Data to Model Determinants of HIV Status and Sexual Risk Behaviours

contributor:
Dushoff, Jonathan
Bolker, Ben
Biology

subject:
HIV
Epidemiology
Condom
Contraceptive
Modelling
Risk
Health Policy
Health Policy

abstract: Sub-Saharan Africa (SSA) continues to be disproportionately burdened by the HIV/AIDS epidemic. In 2011, the region saw 1.8 million new infections, contributing to a prevalence of 4.9% among adults, or 23.5 million people living with HIV/AIDS. This thesis uses data collected by the Demographic and Health Surveys (DHS) to answer questions about risk factors and behaviours associated with HIV acquisition. I use logistic regression models to assess the impact of purported risk factors on sexual behaviours and HIV status. In Chapter One, I evaluate the association between respondents' condom use and their awareness of their own \local" epidemic. In Chapter Two, the association between hormonal contraceptives and risk of HIV infection is examined. The purpose of these analyses is to contribute to the body of literature that identifes factors that mitigate or contribute to risk for HIV infection, and help to inform public health policy.

abstract: Master of Science (MSc)


title: Religious Conceptions and the World of Nature in Ancient Egypt

contributor:
Combs, A. E.
Religious Sciences

subject:
Religious Studies
Philosophy
Philosophy

abstract: This dissertation has two major aims. The first is to achieve a fresh understanding of the relationship between the natural environment and religious conceptions in ancient Egypt. The second is to demonstrate that religious studies have to be both more consciously interdisciplinary and more deliberately comparative. The foundations for the inquiry are laid by a critical analysis of the theories put forward by J. H. Breasted, Henri Frankfort, and John A. Wilson concerning the relationship between nature and ancient Egyptian religion. The general assumption of these three scholars that nature directly influenced Egyptian religious beliefs is found to be untenable. The analysis also reveals the dangers of ignoring comparative material and the great need for an interdisciplinary perspective. Certain selected ideas of Peter L. Berger, a sociologist, are then used to open up a new approach to ~he problem under investigation. A distinction is made between natures- it-is and "the world of nature" created by the ancient Egyptians, and evidence is provided to show how Egyptian religious beliefs were affected by the latter.

abstract: Doctor of Philosophy (PhD)


title: Ultrastable Response-Stimulus Synchronization: Acquisition, Stimulus Control, and a Model of Steady State Performance

contributor:
Kristofferson, Alfred B.
Psychology

subject: Psychology Psychology

abstract: Human beings have a remarkable ability to accurately anticipate the time of occurrence of a predictable sensory event and synchronize an overt response with that event. Presumably this behaviour is mediated by central temporal mechanisms which are involved in timing the delay required to trigger the response at some precise point in time. It was the purpose of this investigation to examine the nature and functioning of these human temporal mechanisms. The basic task, modelled after Kristofferson (1976), involved presenting two brief stimuli, separated by a short time interval. Interstlmulus interval was fixed for a particular subject and the subject was instructed to anticipate the second stimulus, timing from the first, in order to trigger a response which would be manifested in synchrony with onset of the second stimulus. Several modifications were made to this basic response-stimulus synchronization procedure, which included subject-paced trials, and provision of highly salient feedback. These modifications resulted in a significant reduction in the lowest, previous estimate of minimum response latency variance. Minimum variances under 35 msec2 were obtained and the data indicated that response latency variance was independent of mean latency over a range of synchronization intervals from 310 to 550 msec. Within this range, latency distributions were the same, symmetrical, and sharp-peaked, unlike typical reaction time. All responses fell within a 50 msec time window. This independence of mean latency and latency variance was present throughout acquisition. A special technique allowed isolation of the controlling stimuli used for synchronization timing and showed that, in some situations, subjects were able to transfer timing control for synchronization responding from one modality to another with no loss of performance. This was true when transferring between auditory and tactile modalities, but not when visual interval markers were employed. A study of these dissimilar intra-modality findings, using a simple reaction time procedure, suggested that the differences could be attributed to a large afferent latency variance associated with visual stimulation which was not inherent in the other modalities. The role of feedback in acquisition and maintenance of synchronization performance was also examined, using manipulations which either selectively removed a particular source of feedback or altered the integrity of the feedback information. These manipulations provided data which indicated feedback to be one of the most important factors responsible for producing ultrastable stimulus-response latencies variance. and maintaining low The other important levels of response latency factor appears to be prolonged practice at a particular synchronization interval. Results are discussed in terms of support for the notion of nonvariable, centrally-timed delays which can be inserted into the stimulus-response chain. These delays are easily adjustable, but once set, are deterministic. A formal, mathematical model was formulated which describes the response-stimulus synchronization data remarkably well and provides a well-defined theoretical framework for conceptualizing this type of behaviour. From the model, independent variance estimates were derived for both central and efferent components in the stimulus-response chain. Values obtained are consistent with previous estimates derived from quite diverse methodologies in the literature. The model also provided some insight into what changes in processing occur during acquisition of this skill.

abstract: Doctor of Philosophy (PhD)


title: Nesting Behavior of Lactating Norway Rats: Influence of Dams' Choice of Temperature and Pup-Associated Stimuli

contributor:
Leon, M.
Psychology

subject: Psychology Psychology

abstract:
Norway rat dams show an intermittent pattern of contact with their young during the first two weeks postpartum. Previous research has shown that one important factor influencing the length of the intermittent contacts (or nest bouts) is the body temperature of the dam. Dams tend to terminate nest bouts when their body temperature rises, and over the first two weeks postpartum nest bout durations decrease, as the dam experiences an elevation in body temperature during a nest bout both more frequently and more rapidly. In the present series of studies, the analysis of the pattern of mother-young contact is extended to include an investigation of the thermal environment that the dam herself chooses to nest in and the consequences of this choice for the pattern of nesting behaviour. Further, not only are nest bout durations considered in these studies, but also nest bout frequencies and interbout intervals.

It was shown that when dams were allowed to choose from a wide range of surface temperatures they placed their pups on a warm surface (approximately 32ºC) and seemed to prefer to spend time between nest bouts on a fairly warm surface (approximately 24 - 26 ºC). In comparison to dams that were not given a range of temperatures to choose from, dams that established a warm nest site and spent time between nest bouts on a warm surface showed much shorter nest bout durations, a higher frequency of nest bouts (although the frequency of nest bouts that were long enough for milk delivery to occur was similar between groups), and longer durations between nest bouts. While the short nest bout durations were most probably due to the fact that the dams were more likely to experience a fairly rapid rise in temperature during nest bouts, it was necessary to test separately whether the temperature that the dams preferred between nest bouts or the warm temperature at which the pups were maintained contributed to the higher frequency of nest bouts and the prolonged durations between nest bouts. It was found that if dams were forced to spend all interbout intervals on a fairly warm surface (approximately 26ºC), they showed much longer intervals between nest bouts which were typically accompanied by a slow decline in the dam's body temperature. Maintaining the pups at a warm ·temperature during the dam's absence produced prolonged intervals between nest bouts in which milk delivery could occur and also a much higher frequency of nest bouts.

While previous investigations had assumed that the pups play a passive role in the determination of nest bout termination, it was found in the present investigation that the pups played both passive and active roles in the overall pattern of nesting. It was shown that dams maintain contact with pups if the pups are cold. Pups might also play a more active role in maintaining contact with the dam by attaching to the dam's nipples soon after contact is established, because failure to attach to the nipples soon after contact was established frequently led to rapid nest bout termination. Finally, it was found that pups could actively curtail interbout intervals by emitting ultrasonic vocalizations. While ultrasonic vocalizations are typically emitted only when the pups are subjected to some stress, and thus may not be important in a controlled laboratory situation, this finding is of particular significance, as it indicates that the pups are not merely passive recipients of maternal caret but rather are capable of actively altering the pattern of nesting behaviour.

abstract: Doctor of Philosophy (PhD)


title: Identifying the health and supportive care needs of adolescent and young adult survivors diagnosed with cancer: a mixed methods study

contributor:
Klassen, Anne F.
Barr, Ronald D.
Health Research Methodology

subject:
adolescent
young adult
cancer
health
supportive care
needs
Health and Medical Administration
Hematology
Medical Education
Oncology
Health and Medical Administration

abstract:
Purpose: Current cancer programs in Canada manage adolescents (15-18 years) under a pediatric model of care, and young adults (19-25 years) under a disease-centered model of care. Key issues arise because neither of these models adequately meets the needs of adolescents and young adults (AYA). The aim of this study is to identify health and supportive care (HSC) needs of AYA survivors with cancer. Method: A concurrent nested mixed-method design was employed. Qualitative description and a systematic literature review (SLR) were used. Medline, Cochrane Central, PubMed, PsycInfo CINAHL and EMBASE were searched from their date of inception to October 2011. A comprehensive search strategy was developed.
A purposive sample of AYA survivors with cancer, aged 15-25 years were recruited. Face-to-face qualitative interviews were digitally recorded and transcribed verbatim. Line-by-line coding was used to establish codes and categories.
Result: Our SLR retrieved 760 citations. Among them, 12 were relevant. Qualitative findings are based on 20 interviews. Twelve diagnosed during adolescence and eight in young adulthood. Participants described several HSC needs that we categorized into 7 broad themes (e.g., social health) and 29 sub-themes (e.g., social support). Among the most commonly reported HSC needs for AYA survivors with cancer from both studies, were social wellbeing, information-sharing and communication and service provision. Conclusion: This study has identified a comprehensive set of HSC needs of AYA survivors with cancer. Study results will be used to inform the potential development of a new healthcare program for AYA patients in the Hamilton Health Sciences.

abstract: Master of Science (MSc)


title: In-Plane Anisotropy of Ultrathin Co/W(110) Films and the Néel Transition in Bilayer Ultrathin CoO/Co/W(110) Films

contributor:
Venus, David
Physics and Astronomy

subject:
Ultrathin films
Cobalt
Interfacial Exchange Interaction
Transverse Susceptibility
Anisotropy
Néel Transition
Condensed Matter Physics
Condensed Matter Physics

abstract:
The study of ultrathin magnetic films offers novel magnetic phenomena due to the reduced symmetry of these 2D systems. The magnetic anisotropy differentiates behaviour in ultrathin films from the bulk environment, as additional anisotropies emerge from the ultrathin film thickness and the inherent strain of ultrathin films. In this work, the in-plane magnetic anisotropy of strained ferromagnetic (FM) ultrathin Co(0001) films grown on a W(110) substrate is measured over a range of temperatures (150-320 K). Low energy electron diffraction (LEED) and Auger electron spectroscopy (AES) were used to determine the film structure and thickness. The anisotropy is derived from the quotient of the saturation magnetization and the transverse susceptibility, which are measured using the surface magneto-optic Kerr effect (SMOKE).

This work’s second objective is to study the Néel transition in antiferromagnetic (AFM) ultrathin films. The zero net magnetization of AFM materials and the minute sample size of ultrathin films make magnetic measurements impossible with conventional methods. An alternative approach is to study a single AFM ultrathin film that is coupled by the interfacial exchange interaction to a FM ultrathin film. The upper layers of ultrathin Co/W(110) films were oxidized to produce ultrathin CoO/Co/W(110) films, creating an AFM/FM bilayer system. SMOKE measurement of the transverse magnetic susceptibility of the FM Co layer reveal the Néel transition of the AFM layer indirectly through the interfacial exchange interaction.

abstract: Master of Science (MSc)


title: THE EFFECT OF CHOLESTEROL ON THE STRUCTURE OF MITOCHONDRIAL LIKE LIPID BILAYERS: AN X-RAY STUDY

contributor:
Fradin, Cecile
Rheinstädter, Maikel
Dalnoki-Veress, Kari
Physics and Astronomy

subject:
Apoptosis
Cholesterol
Temperature
Mitochondrial Outer Membrane
Bcl-2 Proteins
Bax
Biophysics
Biophysics

abstract: Apoptosis plays a key role in the regulation and development of healthy multicellular organisms throughout their lifetimes. The mitochondria play a key role in this cellular process, as it contains proapoptotic factors, which once released into the cytosol of the cell, results in the death of the cell. The Bcl-2 family of proteins play a key role in apoptosis, acting as the gateway between life and death of the cell. Proteins such as tBid and Bax act to permeabilize the mitochondrial outer membrane (MOM), releasing the proapoptotic factors into the cell’s cytosol. The interactions between these proteins and the mitochondrial outer membrane have yet to be fully understood. The lipid composition and cholesterol content of the membrane effectively inhibit or promote pore formation by Bax. Specifically, the addition of cholesterol into the membrane inhibits pore formation. This thesis attempts to further understand the effects cholesterol has on the structure of the MOM, and link those changes to the inhibited activity of Bax pore formation. MOM-like lipid bilayers were studied under varying temperatures and with the addition of cholesterol using x-ray reflectivity. Increasing temperatures from 10°C to 30°C resulted in bilayer thinning, as did decreasing cholesterol concentrations below 30%. From 10°C to 20°C, bilayer thickness showed a bell shaped profile, and changed to a linear decrease above about 20°C. This may assist Bax in pore formation, as it has also been observed to cause bilayer thinning. Increasing Cholesterol concentrations up to 30% resulted in little variation in bilayer thickness though hindrance of Bax pore formation is observed at content levels as low as 8%. Thus it is unlikely that bilayer thickening by cholesterol causes the inhibition of Bax pore formation. In addition, cholesterol was observed to increase the electron density of the core of the bilayer at concentration levels above 25%.

abstract: Master of Science (MSc)


title: Characterization and Alignment of the STED Doughnut Using Fluorescence Correlation Spectroscopy

contributor:
Fradin, Cecile
Dalnoki-Veress, Kari
Preston, John
Physics and Astronomy

subject:
Confocal Microscopy
FCS
STED
Imaging
Diffusion
Fluorescence
Biophysics
Biophysics

abstract: This report primarily focuses on effectively obtaining a Stimulated Emission Depletion fluorescence (STED) microscope, while using Fluorescence Correlation Spectroscopy (FCS) as a guide for the alignment of the system. STED is a super-resolution microscopy technique that has gained favour in the biological sciences due to its ability to successfully resolve sub-diffraction structures within live cells. Moreover the ease with which it can be combined with FCS has extended the applications of this technique to the study of the dynamics within a system as well. The central premise of this work focuses around building a STED-FCS system and developing an alignment tool for obtaining a symmetric STED doughnut. Since the point spread functions (PSF) seen in confocal microscopy can be generally approximated by a Gaussian function, we approximate the doughnut PSF with a difference of Gaussian functions. We calculated an autocorrelation function (ACF) corresponding to the simplified Gaussian form of the doughnut PSF and we found that this ACF contained three very similar diffusion times, all inversely proportional to the dye diffusion coefficient. In agreement with the fact that the doughnut PSF is spread out compared to the purely Gaussian PSF, the doughnut ACF amplitude is lower and its average diffusion time large. Lastly we calculated the quality factor, which is the product of the amplitude of the correlation function with the average intensity, Q=G(0)*I, for the purposes of alignment of the system. When translating the confocal pinhole along an axis of the doughnut we were able to identify the centre of the doughnut due to the presence of a minimum in Q which can be very handy for alignment of the doughnut with respect to the pinhole. This operation is essential when aligning the excitation and STED beam. For future work, a road map for alignment of the two beams in the focal plane is also presented utilizing the cross correlation function between the two beams.

abstract: Master of Science (MSc)


title: Addiction Services for Older Adults: A Service Provider Perspective

contributor:
Denton, Margaret
Health and Aging

subject:
seniors
substance abuse
drug abuse
age-specific
treatment
addiction
Other Mental and Social Health
Social Work
Substance Abuse and Addiction
Other Mental and Social Health

abstract:
Substance abuse is a major public health concern. Scholars predict a growing proportion of people aged 50 years and older suffering from addiction to alcohol, prescription or over-the-counter medications and/or illegal substances (Wu & Blazer, 2011; Han et al., 2009). Available Canadian statistics reveal that 6-10% of older adults experience alcohol problems, 1% use illegal substances and approximately 6% seek addiction treatment for prescription opioids (Public Health Agency of Canada, 2010; Tjepkema, 2004; CAMH, 2008). Older adults face personal, social, and structural barriers to treatment, which result in a significant number of people living with addiction and remaining undiagnosed and untreated in the community (Crome & Bloor, 2005b). Nevertheless, this issue is significantly understudied and under-recognized, particularly within Canadian literature.

This qualitative research study examined the perspectives of addiction service providers regarding the issue of addiction among older adults. A descriptive, qualitative research design was used to explore the perspectives of addiction service providers using in-depth, semi-structured personal interviews. Purposive sampling techniques were used to recruit 24 service providers employed by Hamilton addiction services. Semi-structured interviews included questions on (a) the current provision of addiction services for older adults, (b) characteristics of older adults (c) perceived barriers to treatment, and (d) recommendations for addressing the needs of older adults living with addiction. The interview also collected demographic information to describe the demographic profile of agencies and research participants involved in the study.

By using Braun and Clarke’s (2006) phases of thematic analysis, this study observed several key themes that confirmed and extended existing literature. New contributions highlight the following: (1) according to service providers, older adults demonstrate a greater readiness for change and stronger commitment to their treatment plan regardless of whether they are enrolled in a mixed-age or age-specific program. (2) Some older adults use substances to cope with cumulative shame that stems from unresolved, traumatic early-life experiences. This new finding supports principles of the life course perspective by highlighting the impact of early life events on late life experiences. (3) Service providers can address some of the age-specific needs of older adults by assigning them to an older counselor in treatment. (4) In order to enhance treatment outcomes, older adults should direct their care and be viewed as experts in their treatment needs. (5) From the perspective of service providers, older and younger adults benefit from interactions with each other when the older adult is in recovery and the younger adult is recovering. Older adults recovering also benefit from interactions with older peers in recovery, particularly when they are in mixed-age programs. Opportunities for peer interaction during and after treatment can produce favourable recovery outcomes.

abstract: Master of Arts (MA)


title: Characterization of the Interaction Between Dbf4 and Rad53 During Replication Stress in Budding Yeast

contributor:
Guarne, Alba
Melacini, Giuseppe
Wright, Gerry
Biochemistry

subject: Dbf4

subject: Rad53

subject: BRCT

subject: FHA

subject: Replication Checkpoint

subject: Biochemistry, Biophysics, and Structural Biology

abstract: All living things must replicate their DNA. Despite being essential for life, this process is also inherently dangerous. Replication stress, which induces replication fork stalling, is an unavoidable risk that can trigger potentially harmful changes to the genome. Eukaryotes have a replication checkpoint pathway that stabilizes stalled replication forks to prevent damage. One of the critical protein interactions in this pathway, between Dbf4 and Rad53, pauses the cell cycle in budding yeast. This is important to give the cell time to recover from stress. The molecular details of this interaction were investigated to shed light on how this association is regulated by the cell. The structure of an N-terminal domain from Dbf4 was solved through X-ray crystallography and discovered to have a modified BRCA-1 C-terminal (BRCT) fold, which included an additional N-terminal helix. This domain could interact with the ForkHead Associated 1 (FHA1) domain from Rad53 in vitro, and the additional helix was necessary for complex formation. Although the FHA1 domain has a well-characterized binding site for phospho-epitopes, a combination of chemical cross-linking and NMR spectroscopy experiments demonstrated that the N-terminal domain from Dbf4 is contacting an alternative surface. However, the full-length Dbf4 protein in vivo may be contacting both this distal site and the phospho-epitope binding pocket. This bipartite interaction between Dbf4 and Rad53 would lend specificity to the complex and also suggests a kinase may be regulating the association. As FHA and BRCT domains are prevalent in eukaryotic nuclear proteins, these findings are instructive for how these domains mediate interactions in other signaling pathways.

abstract: Doctor of Philosophy (PhD)


title: Structural and Electronic Properties of BaV10O15, BaV10-xTixO15, and BaVO3-x

contributor:
Greedan, John E.
Chemistry

subject: Chemistry Chemistry

abstract:
The compound BaV10O15 exhibits a first-order structural phase transition in the temperature range 105K-135K, depending upon the sample. The variation in transition temperature has been correlated with a variation in the lattice parameters and degree of sample oxidation. Crystal symmetry decreases from Cmca in the high temperature phase, to Pbca in the low temperature phase. Single crystal work has shown a decrease in certain V-V distances, which has been attributed to metal-metal bond formation. A cooperative magnetic transition occurs near 42K that contains features of both spin glass behavior and long range magnetic order. Powder neutron diffraction has shown that the moment is much lower than the expected value of 2.2μB. Furthermore, the magnetic entropy released below 70K is less than 15% of the entropy release expected for this moment value.

The series BaV10-xTixO15 (x=0-8) is isostructural with the high temperature phase of BaV10O15. Spin glass-like behavior is observed up to a doping level of ~50% titanium, above which there is no apparent collective magnetic transition. Two models have been proposed to explain the thermopower and resistivity data for this series. The first model is based upon small polaron hopping of localized carriers. The second involves hole doping of instrinsic band semiconductor.

A new preparation route has been developed for 5H BaVO2.8 using the induction furnace. It was determined that addition of 4% to 8% molar excess of vanadium in the reaction produced a pure material. In a study of BaVO2.8 using power neutron diffraction, peaks due to long-range magnetic order were not detected. The possibilities of either a spin-glass or superparamagnetic ground state remain. Transport property measurements on BaVO2.8 suggest that two-dimensional variable range hopping is occurring at low temperatures. With oxidation, the dominant carrier type changes from holes (BaVO2.8) to electrons (BaVO3.0).

abstract: Doctor of Philosophy (PhD)


title: The bivalency effect in task-switching

contributor:
Shedden, Judith M.
Psychology

subject:
bivalency effect
task-switching
ERP
EEG
cognitive control
conflict
Cognitive Psychology
Cognitive Psychology

abstract: During task-switching, if we occasionally encounter stimuli that cue more than one task (i.e. bivalent stimuli), response slowing is observed on all univalent trials within that block, even when no features overlap with the bivalent stimuli. This observation is known as the bivalency effect. Here, I show that the bivalency effect reflects a form of top-down cognitive control that is not easily explained by most current models of control in the literature. The research presented within my thesis reveals that the bivalency effect reflects an adjustment in cognitive control that is highly dependent on past experience with response conflict (chapters 4 and 5), violations of expectancy (chapter 3 and 5), and recent inhibition (chapters 3, 4, and 5). Furthermore, the processes in response to these factors are likely captured by the dorsal anterior cingulate cortex (dACC) and the temporal parietal junction (TPJ) (chapters 2 and 5), reflecting responses to inhibitory demands, and extra visual feature extraction after encountering bivalent stimuli, respectively. These findings provide support for a recent cognitive control model that suggests that the role of the ACC is to track current and recent changes in the environment in order to optimize future performance by predicting changes in cognitive demand (Sheth et al., 2012).

abstract: Doctor of Philosophy (PhD)


title: BUILDING FROM AND MOVING BEYOND THE STATE: The National and Transnational Dimensions of Afro-Brazilian Women's Intersectional Mobilization

contributor: Political Science - International Relations

subject: Race

subject: Gender

subject: Brazil

subject: Transnationalism

subject: Women

subject: Activism

subject: Feminist, Gender, and Sexuality Studies

subject: Latin American Languages and Societies

subject: Race, Ethnicity and post-Colonial Studies

subject: Feminist, Gender, and Sexuality Studies

abstract:
Race and gender categories have rarely operated in isolation in the lives of Afro-Brazilian women, intersecting to shape their historical and social positioning, everyday experiences, and collective activism. Despite opposition from the Brazilian state and some civil society groups, the Afro-Brazilian women’s movement has increased awareness of the specificity of black women’s identities and oppressions. In recent years their activism has moved beyond Brazil’s borders through participation in United Nations (UN) Conferences. Yet, the dynamism of Afro-Brazilian women’s intersectional identities and their strategic use to gain legitimacy in these arenas has remained noticeably understudied.

This dissertation argues that since activist groups do not participate in transnational forums detached from their specific histories and localized experiences, their actions, and strategies must be historically grounded. It draws upon the major arguments of postcolonial feminism, intersectionality, and the political process model to examine how national and transnational processes have shaped the identity articulations and mobilization strategies of Afro-Brazilian women activists. Four distinct processes operating in and outside of Brazil are identified as critical to the identity positions, strategies, and overall trajectory of the Afro-Brazilian women’s movement: colonialism, slavery, democratic transition, and preparations for and proceedings of UN Conferences. The influence of Afro-Brazilian women activists in domestic policy domains and internal movement dynamics are also explored. The result is a comprehensive analysis of the intricate workings of race and gender categories in activist spaces and the multiple historical and contextual factors which shape their configuration, intersection, and impact.

abstract: Doctor of Philosophy (PhD)


title: ADVERSE EVENTS IN CANADIAN MANUAL PHYSIOTHERAPY: THE PATIENT, PRACTITIONER AND RESEARCH EXPERIENCE

contributor:
MacDermid, Joy
Santaguida, Lina P.
Thabane, Lehana
Health Research Methodology

subject:
adverse events
practice patterns
patient beliefs
survey
cohort
pilot study
Physiotherapy
Physiotherapy

abstract: Background and objectives: Physiotherapists provide conservative treatment for neck pain utilizing manual therapies (MT), including spinal manipulation. Adverse events (AE) have been associated with manipulation provided mainly by other professions. Physiotherapy specific data are lacking. Definitions of AEs following MT require clear standardized criteria informed by both practitioners and patients. The objectives of this thesis were to: a) establish practice patterns of spinal manipulation in Canadian manipulative physiotherapists (CMPTs), b) establish patients’ perceptions of an AE related to MT and c) pilot the collection of AE data reported by practitioners and patients. Methods: For the first objective, multiple linear regression of survey data determined the association between experience and frequency of use of manipulation amongst CMPTs. For the second objective, Poisson regression identified predictors of patients more likely to report the occurrence of an AE. The final objective utilized descriptive statistics of patient and practitioner reported AE to assess feasibility for a future large-scale study. Results: For the first, increased experience was associated with increased use of upper cervical manipulation in males (14% more often for every 10 years after certification; beta 1.37, (95% confidence interval) (0.89,1.85) pConclusion: Manipulation by CMPTs remains a valued option as experience increases. Adverse events reported by patients are influenced by expectations. A large cohort study attempting to accurately define and measure AE rates following manipulation will be challenging to perform in private practice settings.

abstract: Doctor of Philosophy (PhD)


title: MEMBRANE AND TEMPERATURE BASED METHODS FOR PROCESSING AND PURIFYING MONOCLONAL ANTIBODIES

contributor:
Ghosh, Raja
Prashant Mhaskar, Ravi Selvaganapathy
Chemical Engineering

subject: Hydrophobic Interaction Membrane Chromatography

subject: Thermal cycling of Monoclonal Antibodies

subject: Chimeric Heavy Chain Monoclonal Antibody (cHCmAb)

subject: Processing and Purification of Monoclonal Antibodies

subject: Membrane Adsorbers

subject: IgG1

subject: EG2.

subject: Amino Acids, Peptides, and Proteins

subject: Biotechnology

subject: Macromolecular Substances

subject: Membrane Science

subject: Other Chemical Engineering

subject: Amino Acids, Peptides, and Proteins

abstract:
Monoclonal antibodies (mAbs) as therapeutic proteins have shown great potential in treatment of various human diseases because of their highly specific nature. This has attracted worldwide attention leading to increased demand for such mAb products. To meet this demand large scale manufacturing is carried out using recombinant mammalian cell culture techniques for high yields and faster production. mAb products are worth the investment if produced in their native state. The quantity of mAb present in such cell cultures is very less and therefore special care is needed while handling them. Purifying antibody molecules from heterogeneous cell culture impurities and maintaining their native functional state is a critical task mainly because these antibodies are labile in nature. Care also need to be exercised during processing because mAbs have inherent tendancy to aggregate which is undesirable since such aggregates in antibody formulation produces immunogenic reaction when injected in humans. The other important factor in mAb purification is the processing cost involved since majority of the total production cost is utilized for purification of mAb. Protein-A chromatography is the first choice for purifying antibodies and is widely adopted. However failure in distinguishing between monomer and aggregate antibody molecules along with harsh acidic processing conditions necessitates the use of further purification steps.

In this work various techniques for mAb processing are discussed and are outlined below:

Removal of impurities from mAbs is a major challenge and this thesis discusses various processing options available to purify these mAbs. Impurities in mAb products are usually the aggregate byproducts formed due to unfolded monomer antibody molecules. These molecules are naturally hydrophobic in nature and display great differences in hydrophobicity on aggregation. Hydrophobic interaction membrane chromatography (HIMC) makes use of this hydrophobicity difference and helps in removal of aggregate impurities from monomer antibody.

Heavy chain mAbs (hcmAbs) are promising new developments in the area of biopharmaceuticals because of their unique structural composition. Similar to conventional mAbs these hcmAbs are also rapidly finding their way into therapeutic markets. Purifying hcmAbs will be an important step in their development and for this purpose we use HIMC technique for removing impurities and obtain pure product.

Antibody molecules are almost always lost as aggregates which leads to great economic losses and the ability to disaggregate these mAb oligomers would be of significant practical and scientific interest. In this work a novel thermalcycling technique is discussed to disaggregate such mAb oligomers and potentially recover functional monomer mAb molecules.

abstract: Master of Applied Science (MASc)


title: Gathering places and neighbourhood sense of place: Exploring single women’s experiences across the life course

contributor:
Williams, Allison
Geography and Earth Sciences

subject:
sense of place
neighbourhood
women
feminist geography
community development
Human Geography
Human Geography

abstract: Sense of place (SoP) at the neighbourhood scale is one phenomenon that can bring to light the forces that shape residents’ experiences of living in urban neighbourhoods, and play a role in shaping their identity. At an even smaller scale are the gathering places of everyday life, where people can come together and spend time on a regular basis. This research is about single women’s experiences of local gathering places and their neighbourhood SoP in Hamilton, Ontario, from a feminist perspective. Feminist research values the knowledge and experiences of research participants and has the goal of understanding the world in order to build a more just society. A qualitative case study was employed, with face-to-face interviews (n=15) being the primary method of data collection. Participants were single mothers and single older women living in a neighbourhood in central-east, lower city Hamilton. This thesis explores the themes resulting from the interviews, including: factors influencing neighbourhood SoP; types of gathering places; social and emotional qualities of gathering places; physical/spatial qualities of gathering places, and; the relationship between gathering places and neighbourhood sense of place. These themes highlight the importance of gathering places to neighbourhood SoP, and the potential for the perspectives and recommendations of the participants to be included in current efforts around neighbourhood development in Hamilton. The results also point to areas for further research around SoP, and next steps for Hamilton in terms of creating a safe and age-friendly city, and engaging in critical community development.

abstract: Master of Arts (MA)


title: Modeling Lung Structure in Rodents

contributor:
Labiris, Nancy
Farncombe, Troy
Inman, Mark
Medical Physics

subject:
Lung Structure
Computed Tomography
Rodents
Airways
Vasculature
Quantitative Histology
Circulatory and Respiratory Physiology
Circulatory and Respiratory Physiology

abstract:
Pre-clinical imaging has provided pulmonary researchers with a number of valuable tools for studying both the lung and lung disease. A greater understanding of the structure/function relationships within the rodent lung would help to bridge the gap between functional images of the lung and its underlying anatomy.

The objectives of this work were to visualize and measure the components of rodent lung anatomy. Contrast-enhanced microCT images were used to visualize the airways and major blood vessels from both the Sprague-Dawley rat and the BALB/c mouse. These observations and measurements were used in the development of a pulmonary lung model containing both the conducting airways and blood vessels. The model can be applied to unenhanced images of the rodent lung to facilitate the regionalization of functional imaging data (SPECT/PET). The model has been used to simulate bronchoconstriction and deposition patterns of inhaled particles. Extensive validation revealed that the model was unable to fully reproduce the rodent lung and that further refinement is necessary.

The finer structure of the rodent lung, which could not be resolved using our microCT system, was measured using histological sections of the rodent lung. Software was developed and validated to automatically quantify the increases in airspace size that are associated with several respiratory conditions.

Together, this work sheds light on the underlying anatomy of the rodent lung that is present in both anatomical and functional images. The knowledge will help researchers to understand some of the structural changes that are occurring with the development of lung disease.

abstract: Doctor of Philosophy (PhD)


title: Learning to walk again: Use of motor learning principles as a theoretical framework for walking-skill training in community-dwelling individuals following stroke

contributor:
Wishart, Laurie R.
Rehabilitation Science

subject:
stroke
motor learning
walking
physiotherapy
rehabilitation
randomized controlled trial
Physiotherapy
Physiotherapy

abstract:
Background: Walking dysfunction is one of the most disabling and persistent of stroke-related sequela. Theory- and research-derived motor learning principles (MLPs) offer an ideal theoretical framework for the development and evaluation of walking-skill focused interventions.

Purpose: To: 1) appraise the degree of adherence to motor learning principles (MLPs) in current post-stroke walking-skill training research; 2) describe the Motor Learning Walking Program (MLWP), a novel, MLPs-framed walking training program; and 3) compare the MLWP to an alternate theory-framed walking-focused intervention in community-dwelling individuals within one year of stroke.

Methods: A scoping review methodology was used to identify the prevalent theoretical frameworks in current post-stroke walking training literature, and to appraise the adherence to selected MLPs in walking-focused interventions. A randomized controlled trial (n=71) was conducted to compare the MLWP to a body-weight-supported treadmill training (BWSTT) intervention.

Results: In the scoping review of 27 walking-focused studies, a minority of investigators explicitly stated a theoretical-framework. Application of MLPs was inconsistent across interventions. In the randomized controlled trial, both intervention groups improved walking function after 5 weeks of training however, there were no significant between-group differences in the primary and secondary outcomes.

Conclusions: To date, there has been limited integration of MLPs into post-stroke walking-skill training literature. This randomized controlled trial is unique in its comparison of two theoretically divergent, yet equally intense, walking-training interventions. While the results were equivocal, future research should continue to explore the impact of application of MLPs on walking-skill recovery after stroke.

abstract: Doctor of Philosophy (PhD)


title: Wendell Berry's Imagination in Place: Affection, Community, and Literature

contributor:
Kroeker, Travis P.
Zdravko Planinc, Jason Peters
Religious Studies

subject: Theological Ethics

subject: Christianity

subject: Religion and Literature

subject: Christianity

subject: Ethics in Religion

subject: Modern Literature

subject: Religious Thought, Theology and Philosophy of Religion

subject: Christianity

abstract:
This thesis argues that Wendell Berry’s idea of a healthy community and his understanding of membership is embodied in his fiction. The imagined community of Port William is neither an ideal blueprint for instantiating a new form of collective life in modern society, nor is it a nostalgic recreation of lost rural communities for representing an alternative culture. Berry’s imagination—both the creative process and its material products—is a funding current for both analyzing North American democracy and its failings as well as cultivating pluralities of communities that address these inadequacies. The form and discipline of Berry’s imaginative engagement with the particularities of his place uncovers the divine creativity operating in it; his fictional writing incarnates his conception and experience of this divine presence as God’s kenotic love. The upshot is not a simplistic return to traditional life but rather an affectionate and self-effacing approach to nature that converges with God’s manner of creating and relating to the world as it is conceived within the Christian tradition. Berry’s moral imagination emerges from a cultural approach to Christianity that engenders people who seek out those aspects of society and moments in life that are struggles—for justice, happiness, reconciliation—in order to incarnate a loving openness to others that does not re-inscribe further failures of Western consumer culture and political economy.

Berry’s imagined community educates the affections in order to transform the way in which we relate to one another and treat the environment. His fiction is an education in being at home in the world as it is where we find it. Rather than theorizing the structure of a locally adapted community, or offering techniques for establishing the existence of such a community, Berry shows us how to live where we are through literary biography.

abstract: Doctor of Philosophy (PhD)


title: Methodological Issues in Design and Analysis of Studies with Correlated Data in Health Research

contributor: Clinical Epidemiology/Clinical Epidemiology & Biostatistics

subject: longitudinal study

subject: cluster randomized trials

subject: correlated data

subject: missing data

subject: imputation

subject: sample size calculation

subject: Clinical Trials

subject: Longitudinal Data Analysis and Time Series

subject: Survival Analysis

subject: Clinical Trials

abstract: Correlated data with complex association structures arise from longitudinal studies and cluster randomized trials. However, some methodological challenges in the design and analysis of such studies or trials have not been overcome. In this thesis, we address three of the challenges: 1) Power analysis for population based longitudinal study investigating gene-environment interaction effects on chronic disease: For longitudinal studies with interest in investigating the gene-environment interaction in disease susceptibility and progression, rigorous statistical power estimation is crucial to ensure that such studies are scientifically useful and cost-effective since human genome epidemiology is expensive. However conventional sample size calculations for longitudinal study can seriously overestimate the statistical power due to overlooking the measurement error, unmeasured etiological determinants, and competing events that can impede the occurrence of the event of interest. 2) Comparing the performance of different multiple imputation strategies for missing binary outcomes in cluster randomized trials: Though researchers have proposed various strategies to handle missing binary outcome in cluster randomized trials (CRTs), comprehensive guidelines on the selection of the most appropriate or optimal strategy are not available in the literature. 3) Comparison of population-averaged and cluster-specific models for the analysis of cluster randomized trials with missing binary outcome: Both population-averaged and cluster-specific models are commonly used for analyzing binary outcomes in CRTs. However, little attention has been paid to their accuracy and efficiency when analyzing data with missing outcomes. The objective of this thesis is to provide researchers recommendations and guidance for future research in handling the above issues.

abstract: Doctor of Philosophy (PhD)


title: Lightcurve Analysis of Eclipsing Binaries Containing Cepheids

contributor:
Welch, Douglas L.
Physics and Astronomy

subject:
Physics and Astronomy
Physics
Physics

abstract:
A method for solving the lightcurve of an eclipsing binary system which contains a Cepheid variable as one of its components is presented. We construct a geometric model where the component stars are assumed to be spherical and on circular orbits. The emergent system flux is computed as a function of time, with the intrinsic variations in temperature and radius of the Cepheid treated self-consistently. Fitting the adopted model to photometric observations, incorporating data from multiple bandpasses, yields a single parameter set best describing the system.

This method is then applied to three eclipsing Cepheid systems from the MACHO Project Large Magellenic Cloud database: MACHO ID's 6.6454.5, 78.6338.24 and 81.8997.87. Best-fit values are obtained for each system's orbital period and inclination and for the relative radii, relative surface brightnesses and limb-darkening coefficients of each star. Pulsation periods, radial amplitudes and parameterizations of the intrinsic surface brightness variations of the Cepheids are also obtained.

The system 6.6454.5 is found to contain a 4.97-day Cepheid with an unexpectedly brighter companion. The system 78.6338.24 consists of a 17.7-day, W Vir Class Type II Cepheid with a smaller, dimmer companion. And the system 81.8997.87 contains an intermediate-mass, 2.03-day overtone Cepheid with a dimmer, red giant secondary.

For each star, an LMC distance modulus of 18.5 mag was used to convert mean magnitudes into luminosities, and effective temperature values were found from a Teff - (V-R) calibratation. Comparison with theoretical tracks and isochrones.

A complete inventory of observations of all three systems is listed, including data not utilized in this work.

abstract: Master of Science (MS)


title: Environmental History of Northern Cod from Otolith Isotopic Analysis

contributor:
Schwarcz, H.P.
Geology

subject: Geology Geology

abstract:
The study was concerned with analyzing the stable isotopic compositions (18O/16O, 13C/12C ratios) of otoliths from Atlantic cod (Gadus morhua) of the northern cod stock off the east of Newfoundland and Labrador, Canada. The purpose was to examine whether environmental changes in the northwest Atlantic, particularly cold temperatures, in the early 1990s may have influenced the collapse of this stock. A number of separate studies were also conducted to examine some of the factors which may influence the isotope ratios of otoliths to aid our interpretation.

Cod from both inshore and offshore locations in Newfoundland were collected and 13C/12C and 15N/14N ratios of muscle tissue were analyzed to quantify the effect of ontogenetic diet change on the isotopic composition of metabolic carbon. Parallel isotopic increase of carbon (+2.6%) and nitogen (+3.6%) in muscle tissue confirmed that cod undergo almost continuous trophic level change related to ontogenetic diet change in early life. Otoliths from some of the same fish were then examined to determine if this trophic level change effects otolith 13C/12C ratios. A significant correlation was found between muscle isotope ratios of tissue and otolith. Ontogenetic diet change can explain up to 80% of the otolith's variation in 13C/12C with age. An additional decrease of 20% in the proportion of metabolic carbon between juvenile and adult cod explains the remainder of the variation. We then examined otoliths from nothern cod to look at their lifetime 13C/12C records. These records were remarkably consistent across the study area indicating that similar biological factors are at work in all cod. Stock components could be identified based on their characteristic isotopic signatures and there was some indication that juveniles from different areas were feeding at different trophic levels. Long-term environmental change seemed to be reflected in decreased 13C/12C during the mid-1980s. The exact cause of this change, however, remains uncertain.

To aid in the interpretation of the oxygen records, an extensive survey of 18O/16O in seawater was carried out over the Newfoundland and Labrador Shelves, examining spatial and temporal variation. There is an inshore to offshore gradient between low salinity and 18O/16O near shore and high salinity and isotope ratios offshore and also a strong linear correlation between isotope ratios and salinity. These observations were combined with isotopic records of individual northern cod otoliths to examine migration and environmental change. Most of the individual records displayed increasing ratios with age indicating an important ontogenetic habitat change towards higher salinity waters. Inshore cod form a distinct group with distinctly different lifetime records of 18O/16O. There is also a temporal trend towards lower mean adult and juvenile values which may indicate changes in recruitment and is consistent with a southward shift in distribution of northern cod.

abstract: Doctor of Philosophy (PhD)


title: Stratigraphy, Paleoecology and Functional Morphology of Heteromorph Ammonites of the Upper Cretaceous Nanaimo Group, British Columbia and Washington

contributor:
Wastermann, G.E.G.
Geology

subject: Geology Geology Geology

abstract:
The litho- and biostratigraphy of the Upper Cretaceous Nanaimo Group of the Vancouver Island region is revised on the bases of new fossil and field data. The Extension, Ganges and Protection Formations, recently subordinated into the Extension-Protection Formation by Muller and Jeletzky (1970) are readily mappable units, and are redefined as separate formations. The Haslam Formation contains previously unrecognized turbiditic facies. A new range zone, based on the range of Baculites chicoense Trask and Submortoniceras chicoense (Trask) is superjacent to the Schmidti Zone and subjacent to the Vancouverense Zone. The Pacificum subzone of the Vancouverense Zone (Muller and Jeletzky, 1970) is given full zonal status because of the non-overlap of Metaplacenticeras cf. pacificum (Smith) and Pachydiscus suciaensis (Meek).

The paleoecology of the Elongatum Zone is examined using multivariate techniques. Four faunal assemblages are differentiated with cluster analysis: an inocerami-ammonite assemblage, a deposit-feeding bivalve dominant assemblage, an infaunal suspension feeding bivalve assemblage, and an anomiid bivalve-ammonite assemblage. The majority of the heteromorph ammonites of the Nanaimo Group were facies independent, suggesting either a wide enviromental tolerance, or extensive post - mortal transportation.

A detailed morphological examination of a number of Nanaimo Group heteromorph ammonites indicates near or neutral buoyancy for the complete living animal and shell.

Volume and density estimates for the heteromorphic species Didyrnoceras (Bostrychoceras) elongaturn (Whiteaves), Glyptoxoceras subcompressum (Forbes), Ryugassella ryugasensis Wright and Matsumoto, Baculites inornatus (Meek), B. anceps pacificus Matsumoto and Pseudoxybeloceras (Cyphoceras) nanaimoense Ward and Mallory all show positive buoyancy for complete animal without cameral fluid. A new technique to simulate living positions using exact and scale models made.of microcrystalline sculpting wax of varying densities is employed. Baculitids show a near-vertical orientation in all growth stages. D. elongatum has a vertical orientation (apex upwards) until formation of the U-shaped body chamber, when a slight tilting of the entire shell takes place. G. subcompressum, with a complex sequence of orthoconic, torticonic and finally gyroconic stages, shows a variety of attitudes. The hamitid P. nanaimoense shows a progressive "tumbling" in orientation during growth.

abstract: All copies in McMaster University’s holdings are missing p. 54; and p.55 is duplicated. McMaster Digitization Centre, 15 February 2019.

abstract: Doctor of Philosophy (PhD)


title: CHARACTERIZATION OF BCL-2 INTERACTING PARTNERS AT THE ENDOPLASMIC RETICULUM

contributor:
Andrews, David W.
Brian Leber, Ray Truant
Biochemistry

subject:
Breast Cancer
Programmed Cell Death
Autophagy
Endoplasmic reticulum
Bcl-2 family
Apoptosis
Biochemistry
Biochemistry

abstract:
Cancer occurs when cells acquire a number of mutations that trigger uncontrolled cell growth. The normal cellular response to this dysregulation of growth is the activation of programmed cell death. While focus in cancer research has been mainly concentrated in the mechanism of programmed cell death at the mitochondria, endoplasmic reticulum is slowly emerging as an essential platform for this regulatory mechanism.

Bcl-2 is the founding member of the Bcl-2 family of protein, which contributes to the regulation of cell death at the mitochondria and at the endoplasmic reticulum. Previously in our lab, we have shown using MCF-7 cells stably expressing Bcl-2 targeted to the endoplasmic reticulum; they were protected from estrogen deprivation induced cell death. Thus the regulatory mechanism of Bcl-2 at the endoplasmic reticulum represents an interesting avenue to improve current cancer therapeutics.

Two approaches were utilized to identify and characterize Bcl-2 and its interacting partners at the endoplasmic reticulum. Using an affinity tag fused to Bcl-2 that has been engineered to target the endoplasmic reticulum, tandem affinity purification was utilized to identify novel Bcl-2 interacting partners when estrogen receptor positive cells are treated with estrogen deprivation. Using fluorescent protein fused to the proteins of interest, Fluorescent Lifetime Imaging Measurement (FLIM) was used to characterize the interactions of Bcl-2 and its known interacting partner at the endoplasmic reticulum. The findings of this thesis verify the applications of the two aforementioned methods in the study of Bcl-2 interacting proteins at the endoplasmic reticulum.

abstract: Master of Science (MSc)