title: ON THE ORIGIN AND FUNCTION OF WAXING AND WANING IN PACEMAKER ACTIVITY IN THE SMALL INTESTINE

subject:
Interstitial cells of Cajal
slow wave
waxing waning
segmentation
continuous wavelet transmformation

abstract: The small intestine of the gastrointestinal tract displays a variety of motor patterns involved in the mixing, digestion, and propulsion of luminal content. Ultimately, it is the co-ordinated effort of smooth muscle contraction influenced by neural and myogenic stimulation that facilitate these motor patterns. While neural input from the enteric nervous system (ENS) and slow wave producing activity of the peacemaking interstitial cells of Cajal (ICC) in the myenteric plexus (ICC-MP) are key players in the manipulation of smooth muscle cells, the mechanisms behind the onset the segmentation motor pattern are currently unknown. I have demonstrated with intracellular recordings of electrical activity from circular smooth muscle cells, the same nutrient stimulants used to induce the segmentation motor pattern in whole organ preparations evokes the waxing waning phenomenon of the smooth muscle slow wave. Through the use of continuous wavelet transformation analysis on nutrient induced waxing waning, it was determined that the induction of a rhythmic low frequency component is responsible for the generation of waxing waning. Stimulated low frequency activity after methylene blue mediated elimination of ICC-MP slow wave activity suggested the low frequency component did not originate from the ICC-MP. The hypothesis emerged that the ICC of the deep muscular plexus (ICC-DMP), on the opposite side of the circular muscle thickness to the ICC-MP, were responsible for the low frequency oscillations. ICC-DMP networks in close physical proximity to nerve fibers were found to be under tonic inhibited by nitric oxide, and to respond to substance P stimulation. Both alleviation of the inhibition and stimulus by tachykinergic neurotransmission induced the low frequency component and waxing waning. The ENS and myogenic pacemakers play an important role in stimulating the segmentation motor pattern. ICC-DMP are the pacemakers responsible for generation of the low frequency component involved in waxing waning and segmentation.

abstract: Master of Science (MSc)


title: Molecular developmental analysis of artificial selection response in the male sex combs of Drosophila melanogaster

contributor: Dr. Richard Morton, Dr. Bhagwati Gupta and Dr. Ana Campos

subject:
Melanogaster
Sex Combs
artificially selected lines
doublesex
Sexcomb reduced
Developmental Biology
Developmental Biology

abstract: Evolutionary innovations, at the molecular level, represent the novel establishment of regulation networks among previously unconnected genes. Understanding the cellular and molecular mechanisms that underlies the development of such innovations is of central importance in evolutionary-developmental research (evo-devo). The sex comb of Drosophila is an excellent model to study the molecular basis of evolutionary innovations. Highline and Lowline are two artificial selected D. melanogaster lines differing in the number of sex comb bristles. It was expected that the “cross-regulation loop” between two transcription factors, Doublesex male isoform (DSXM) and Sexcombs reduced (SCR), evolves rapidly and promotes the morphological evolution of sex combs. We used immunofluorescent technique (antibody staining) to compare the expression of DSXM and SCR in the forelegs of three different lines (Highline, Wildtype and Lowline). We hypothesized that artificial selection will increase expression of DSXM and SCR in the Highline and reduce expression in the Lowline. The fluorescent pictures of antibody staining experiments indicate that the expression region of DSXM in the Highline is significantly higher than the expression region in the Lowline, and the expression levels of SCR has minor difference among the three lines. DSXM expression is altered by the artificial selection, but SCR expression is not. The influence of artificial selection appears to have been constrained by development. Our investigation provides an approach to test the validity of the models of cross-regulation s between SCR and DSXM during development.

abstract: Master of Science (MSc)


title: Feminist Resistance in the GTA: Stories of Feminist Struggle, Resistance and Success During the Harris Years (1995-2001)

contributor:
Storey, Robert
Sugiman, Pamela
Baines, Donna
Sociology

subject:
Feminist Organizations
Feminist Struggles
Resistance and Success
Neoliberalism
Ontario
Gender and Sexuality
Inequality and Stratification
Politics and Social Change
Sociology
Gender and Sexuality

abstract: While neoliberalism has increasingly been entrenched in the province of Ontario, it has also encountered resistance. A primary goal of this dissertation is to provide a vivid historical account of women’s organizing and feminist resistance that emerged during the Harris years (1995-2001). Drawing on the narratives of thirty three feminist activists and leaders working within three different organizational settings, namely organized labour, anti-racist, and anti-violence organizations, this research project aims to capture an important moment in time when women and feminists were speaking out against some of the most pressing issues of the day including gender (in)equality, poverty, violence, sexism, racism and discrimination. Thematically, this research highlights the numerous challenges, strategies and successes experienced by a variety of differently located feminists and women’s groups. By theoretically and analytically situating these women’s narrative accounts within a qualitative, intersectional feminist framework, this collection of stories not only allow us to (re)examine theoretical and practical issues related to intersectionality and pose questions for the present state of feminist organizations, but also contributes to our understanding of feminist organizational resistance in the future, the long-term impact of said resistance and how we might go about addressing the challenges that lie ahead.

abstract: Doctor of Philosophy (PhD)


title: LOWER LIMB MUSCLE ASSESSMENT USING DIFFUSION TENSOR AND BLOOD OXYGEN-LEVEL DEPENDENT IMAGING

contributor:
Noseworthy, Michael D.
Medical Physics

subject: Magnetic Resonance Imaging (MRI)

subject: Skeletal Muscle

subject: Lower Limb

subject: Diffusion Tensor Imaging (DTI)

subject: Blood Oxygen-Level Dependent (BOLD) Imaging

subject: Physics

subject: Physics

abstract:
Diffusion tensor (DT) and blood oxygen-level dependent (BOLD) imaging are two noninvasive magnetic resonance (MR) techniques that have been used to probe skeletal muscle microstructure and microvasculature, respectively. Over a series of four studies, the work in this thesis aimed at furthering our understanding of baseline DT metrics and BOLD signals in lower limb muscles (calf and foot) of healthy young subjects. Since postural changes have been shown to alter numerous quantities, including fluid volumes and muscle cross sectional area, DT indices and BOLD signal characteristics were examined in response to movement from upright to supine position.

Reductions of 3.2-6.7% and 3.4-7.5% were measured in calf DT eigenvalues and apparent diffusion coefficient (ADC) in the various muscles, following 34 and 64 minutes of supine rest, respectively (P

Establishment of baseline diffusion metrics in the foot region was feasible (chapter 6). Examination of foot DT indices in response to positional change showed that the metrics decreased from 2.7-4.6% following 34 minutes of supine rest (P

abstract: Doctor of Philosophy (PhD)


title: Identification of pry-1/Axin Mediated Wnt Signaling Targets in C. elegans and C. briggsae

contributor:
Gupta, Bhagwati
Jacobs, Roger
Biology

subject:
Molecular genetics
Molecular genetics

abstract: The Wnt signaling pathway plays a vital role in a multitude of cellular processes across a breadth of multicellular organisms, from simple nematode roundworms such as the Caenorhabditis species to humans. Through the study of this evolutionarily conserved signal transduction pathway in a simple model organism, a greater understanding of the regulation and function of the Wnt pathway can be gained. Emerging research is highlighting the promiscuous nature of Wnt signaling within the network of signaling pathways involved in C. elegans development and aging processes. However, impeding the study of the diverse roles of Wnt signaling in the nematode is the fact that little is known about regulation of key Wnt pathway components in the nematode species, and only a handful of downstream Wnt pathway target genes have been identified. We have used parallel genetic and genomic approaches to elucidate transcriptional targets of the Wnt pathway in C. elegans and the related species C. briggsae. This analysis has uncovered an array of putative Wnt pathway gene targets including pry-1/Axin, a key regulatory component of the pathway. Furthermore, our genome-wide search for Wnt targets has revealed a novel interaction between the Wnt and Hedgehog signaling pathways that is conserved between these two nematode species.

abstract: Master of Science (MSc)


title: Structuring Silicones and Silica at Interfaces

contributor:
Brook, Michael A.
Chemistry

subject:
siloxanes
elastomers
colloids
emulsions
films
resins
Materials Chemistry
Organic Chemistry
Polymer Chemistry
Materials Chemistry

abstract:
The development of both silica and silicones has led to enormous improvements in available products over the last 50 years: the compounds have now found practical applications in fields ranging from electronics to biomaterials. Both of these materials have several desirable intrinsic properties. The compounds can be combined as a blend, in a composite or at an interface with other compounds to tune the chemical and physical properties to those desired. On their own, silica and silicones also have many applications. Their utility would be enhanced if it was possible to improve morphological control of the materials independently or together.

This thesis explores various parameters and factors that enable the structuring of elastomers, colloids/suspensions, films and foams with the use of unconventional or new organosilicon chemistries. Specifically, amine and boron based catalysts are utilized to catalyze silicone and silica formation at different interfaces to create the materials mentioned above. Potential applications for these materials include drug delivery, GC chromatography and paper-based diagnostics.

abstract: Doctor of Philosophy (PhD)


title: The Interactome at the N17 Domain of Huntingtin

contributor:
Truant, Ray
Singh, Sheila
Biochemistry and Biomedical Sciences

subject:
Huntington's Disease
huntingtin interactors
SET-beta
vimentin
oxidative stress
cell stress screening
Neuroscience and Neurobiology
Neuroscience and Neurobiology

abstract: Huntington’s disease (HD) is an autosomal dominant neurodegenerative disorder caused by a polyglutamine expansion in the huntingtin protein. Recent research demonstrates that post-translational modifications of huntingtin could be an important determinant of mutant huntingtin’s toxicity in HD. In particular, phosphorylation at residues serine 13 and 16 within the first 17 amino acids of huntingtin (N17), have been shown to be critical modulators of mutant huntingtin’s toxicity and localization, and can be triggered by stress. This project aims to study how phosphorylation within N17 alters the interactome at this site and what physiological stress results in the nuclear localization of N17 and huntingtin. The initial search to identify potential interactors was conducted through an affinity chromatography assay using a wild type striatal cell line derived from knock in mouse model of HD. Fluorescent lifetime imaging microscopy (FLIM) to determine Fӧrester resonance energy transfer (FRET), co-immunoprecipitation and co-immunofluorescence assays were then used to validate real interactors of N17. Analysis from this project has validated two previously unidentified interactors of N17; SET, a small nucleo-oncoprotein, and vimentin, a type 3 intermediate filament. Both interactors have suggested two potentially novel roles for N17 within huntingtin, in cell cycle regulation and intermediate filament dynamics. Finally, smart screening techniques using stress-inducing compounds reveal that the sensitivity of N17 to stress and its subsequent nuclear localization can be attributed in part to activation of oxidative stress pathways. Data shown here can be expanded upon to elucidate how huntingtin function and response to cell stress are regulated and mediated via N17 and potentially how this mechanism is disrupted within HD.

abstract: Master of Science (MSc)


title: Proposed Summary Measures for Ranking Treatments in Network Meta-Analysis

contributor:
Beyene, Joseph
Mathematics and Statistics

subject:
Statistical Methodology
Statistical Methodology

abstract: Network meta-analysis (NMA) is a process by which several treatments can be simultaneously compared for relative effectiveness. When conducted in a Bayesian framework, the probability that each treatment is ranked 1st, 2nd and so on can be calculated. A square matrix of these probabilities, referred to as the rank probability matrix, can be structured with rows representing treatments and columns representing ranks. In this thesis, a simulation study was conducted to explore properties of five proposed rank probability matrix summary measures: determinant, Frobenius norm, trace, diagonal maximum and diagonal minimum. Each measure is standardized to approach 1 for absolute certainty. The goal of this simulation is to identify strengths and weaknesses of these measures for varying networks. The measures are applied to previously published NMA data for further investigation. The simulation study and real data analysis revealed pros and cons of each summary measure; the Frobenius norm was found most effective. All summary measures yielded higher values with increases in symmetry, relative effect size and number of studies in the network. If the rank probability matrix is used as the primary output of a network meta-analysis (as is often the case), a simple measure of the overall confidence in the rankings is beneficial. Future research will require exploration into the distributions of these measures.

abstract: Master of Science (MSc)


title: MICROFLUIDIC DEVICE FOR MICROINJECTION OF CAENORHABDITIS ELEGANS

contributor:
Selvaganapathy, P. R.
Gupta, Bhagwati
Mechanical Engineering

subject:
Microfluidic
Microinjection
C. elegans
Transgenic
Behavioral Neurobiology
Biological Engineering
Biology
Biomechanical Engineering
Biomedical devices and instrumentation
Behavioral Neurobiology

abstract: Microinjection is an established and reliable method to deliver transgenic constructs and other reagents to specific locations in the animal. Specifically, microinjection of a desired DNA construct into the distal gonad is the most widely used method to generate germ-line transformation of C. elegans. Although, current C. elegans microinjection method is an effective manner for creating transgenic worms, it requirements such as expensive multi DOF micromanipulator, detailed injection alignment procedure and skilled operator which makes the microinjection process slow and not suitable for scale to high throughput. Although many microfabricated microinjectors exist, none of them are capable of immobilizing a freely mobile animal such as C.elegans worm. In this research, a microfluidic microinjector was developed to simultaneously immobilize a freely mobile animal such as C.elegans and perform microinjection by using a simple and fast mechanism for needle actuation. The entire process of the microinjection takes ~30 seconds which includes 10s for worm loading and aligning, 5s needle penetration, 5s reagent injection and 5s worm unloading. The capability of the microinjector chip for creating transgenic C. elegans was illustrated (with success rate between 4% to 20%)

abstract: Master of Science (MSc)


title: Double-Rotor Switched Reluctance Machine for Integrated Electro-Mechanical Transmission in Hybrid Electric Vehicles

contributor:
Emadi, Ali
Schofield, Nigel
Habibi, Saeid
Electrical and Computer Engineering

subject:
Double-rotor
DRSRM
hybrid electric vehicles
HEV
integrated transmission
switched reluctance machine
Power and Energy
Power and Energy

abstract:
The world transportation sector has been relying on the oil industry for more than a hundred years, accounting for the largest oil consumption and one third of the greenhouse gas emissions. However, with the boosting demand, escalating national energy security concerns and emerging environmental issues, reducing and displacing petroleum fuel in transportation sector has become an urging global target. As a result, hybrid electric vehicles evolve as one solution to displace petroleum fuel by utilizing vehicle onboard electrical systems, achieving higher fuel economy and less emissions by vehicle electrification and hybridization.

However, since hybrid electric vehicles add additional electrical components and systems to realize better fuel economy, the system complexity increases and thus the cost increases. Hence, it is an objective of this thesis research to focus on the integrations and optimizations, aiming to simplify and optimize the hybrid power-trains in both system level and component level.

This thesis contributes to a novel integrated electro-mechanical hybrid transmission that is potentially more compact and more operational flexible with fewer components compared to the GM Allison Two-Mode hybrid transmission. Comprehensive commercialized power-train transmissions are reviewed and analyzed to serve as background information for comparison. It also contributes to a family of double-rotor switched reluctance machines that are more integrated and suitable for hybrid electric vehicle applications. A prototype double-rotor switched reluctance machine has been built and tested for concept proving. Detailed machine design process is reported with the emphasis on design novelties. Finite element analysis and optimization techniques are applied and the accuracy is confirmed by the experiments. In addition, methods of machine loss analysis, thermal analysis and drive analysis are established; manufacturing and testing procedures are documented in detail that can be used for future machine designs guidance.

abstract: Doctor of Philosophy (PhD)


title: NOVEL ROLES FOR NEU1 SIALIDASE IN LIPOPROTEIN METABOLISM AND INFLAMMATION: BRIDGING MOLECULAR MECHANISMS IN ATHEROSCLEROSIS

contributor:
Igdoura, Suleiman
Trigatti, Bernardo
Biology

subject:
Atherosclerosis
Sialidase
Neuraminidase
Neu1
Lipoprotein
Inflammation
Molecular Biology
Molecular Biology

abstract: Atherosclerosis is a complex multi-factorial disease that involves the interaction of many cell types and a plethora of molecular events. Initiation of the disease occurs when circulating LDL gets trapped in the sub-endothelial space of arteries, where LDL is oxidized causing inflammatory responses by endothelial cells. This results in recruitment and differentiation of monocytes into macrophages; macrophages in turn continue to take up cholesterol and propagate inflammation. Such a gloomy milieu of immune cells, lipids, and smooth muscle cells can give rise to atherosclerotic plaques, which then cause stenosis, vascular stiffening and eventually thrombosis. Common risk factors such as cholesterol levels, lifestyle and genetic predisposition can accelerate this potentially life threatening series of events. The downstream long-term effects of atherosclerosis, including heart disease and strokes, are now the number one cause of death in the world. While a large amount of knowledge and evidence is available in understanding this disease, prevention and treatment strategies remain somewhat ineffective. Sialylation of immune cells, lipoproteins and cellular receptors has been previously implicated in metabolic and molecular pathways relevant to atherosclerosis; however, little is known about the functional role of sialidase in these processes. Sialidase cleaves sialic acid, and is a ubiquitously expressed and evolutionarily conserved protein with essential functions in many life forms. In this study, we sought to investigate the impact of sialidase activity on atherosclerosis, emphasizing the interaction of lipid metabolism and inflammation. We have demonstrated a significant role for sialidase in cholesterol iv and lipoprotein metabolism in vivo. Specifically, hypomorphic sialidase mice have increased hepatic storage of lipids and triglycerides, decreased VLDL production, lower circulating LDL levels and alterations in regulation of LDLR. Mice over-expressing hepatic human sialidase have increased atherosclerotic lesion formation, higher serum cholesterol esters and lower levels of hepatic LDLR and SRB-1 protein. In vitro, we have shown that VLDL can induce differentiation and cytokine production in monocytes coupled with an up-regulation of Neu1. Inhibition of sialidase using DANA attenuated VLDL-induced monocyte differentiation and lipid uptake, as well as activation of macrophages, implicating Neu1 in inflammatory processes associated with initiation of atherosclerosis. Furthermore, we have shown that hypomorphic sialidase activity increases LDLR-dependent LDL uptake and cholesterol efflux to HDL in macrophages. We conclude that reduction of sialidase activity can lead to an atheroprotective phenotype with multiple effects on mechanisms involved in disease progression. This work represents novel contributions into delineating both metabolic and inflammatory processes of atherosclerosis and enables the advancement of future treatment strategies.

abstract: Doctor of Philosophy (PhD)


title: Functional Studies of TRF2 and its Interacting Proteins in Maintaining Telomere Length and Integrity

contributor:
Zhu, Xu-Dong
Biology

subject:
Telomeres
Aging
Molecular biology
Cancer
DNA damage
senescence
Cell Biology
Cell Biology

abstract: The ends of eukaryote chromosomes, a region called the telomeres, plays a critical role in maintaining genome stability. With each round of mitotic division the telomeres erode until a critically short length is reached, which signals the cell to permanently stop dividing. This is recognized as a contributing factor to ageing and the onset of age related diseases. Telomere repeat binding factor 2 (TRF2), is an important telomere DNA binding protein that has an essential role in protecting telomeres from being recognized as DNA breaks, however it has also been implicated in other aspects of telomere maintenance, such as telomere replication and telomere transcription. TRF2 acts as a protein hub for the recruitment of a number of telomere associated proteins involved in telomere maintenance, and it has been shown to be heavily modified by numerous types of post-translational modification. We demonstrate that TRF2 is methylated on arginine residues in its N-terminal region by protein arginine methyltransferase 1 (PRMT1) and that this arginine methylation is important for proper telomere maintenance. We further demonstrate that methylated TRF2 is a component of the nuclear matrix and has a distinct staining pattern in senescent cells. The importance of telomeres to ageing is exemplified by previously reported observations that defects in telomere maintenance are a common characteristic to numerous premature ageing disorders. We show that the premature ageing disorder, Cockayne Syndrome has an underlying defect in telomere maintenance. Approximately 80% of Cockayne Syndrome patients have mutations in the Cockayne syndrome group B (CSB) protein. We identified a novel interaction between TRF2 and CSB. The work presented in this thesis characterizes these novel interactions and gives new insight into the function of TRF2 in telomere maintenance.

abstract: Doctor of Science  (PhD)


title: EXAMINATION OF ENZYMATIC ACTIVITY AND SUBSTRATE SPECIFICITY IN ENZYMES INVOLVED IN THE PHOSPHATIDYLINOSITOL CYCLE

contributor:
Epand, Richard
Yang, Daniel
Truant, Ray
Biochemistry and Biomedical Sciences

subject: Lipid metabolism

subject: signal transduction pathways

subject: acyl chain specificity

subject: phosphatidylinositol cycle

subject: diacylglycerol kinase epsilon

subject: CDP-DAG synthase

subject: Biochemistry, Biophysics, and Structural Biology

abstract: Phosphatidylinositol (PI) is a phospholipid that constitutes only a minor component of eukaryotic membranes. However, they are critical in many fundamental cellular processes, such as signal transduction pathways, vesicular trafficking and actin cytoskeletal dynamics. PI is highly enriched in specific acyl chains at both the sn-1 and sn-2 positions, the major species being 1-stearoyl-2-arachidonoyl. Enzymes required for PI synthesis are believed to play a major role in this enrichment through the selective catalysis of specific substrates. We have studied several aspects of two enzymes involved in PI synthesis, Diacylglycerol kinase ε (DGKε) and CDP-Diacylglycerol synthases (CDS). We have studied the role of the ATP-binding motif of DGKε and showed that this enzyme is not only required for enzymatic activity, but substrate specificity and sub-cellular localization. We have also looked at the region adjacent to the catalytic site, containing a cholesterol recognition motif, and determined that this also affects the enzymes activity and substrate specificity. Finally, we have characterized the enzymatic properties of two CDS isoforms in vitro and demonstrated that these isoforms exhibit different substrate specificities. Taken together, our results serve to further our understanding of both DGKε and CDS1/2 and their roles in PI synthesis and enrichment with specific acyl chains.

abstract: Master of Science (MSc)


title: Using Förster Resonance Energy Transfer (FRET) To Define the Conformational Changes of Huntingtin at the Clinical Threshold for Huntington’s Disease

contributor:
Truant, Ray
David Andrews, Jon Draper
Biochemistry and Biomedical Sciences

subject:
Huntington's disease
huntingtin
biosensor
FRET
Medical Cell Biology
Medical Molecular Biology
Nervous System Diseases
Medical Cell Biology

abstract: Huntington’s disease (HD) is a progressive, neurodegenerative disorder that leads to the selective loss of neurons in the striatum and the cerebral cortex. HD is caused by a CAG trinucleotide repeat expansion beyond the normal length in the IT15 (Htt) gene. The CAG stretch codes for an elongated polyglutamine tract within the amino‐terminus of the huntingtin protein. Polyglutamine tracts with lengths exceeding 37 repeats cause HD whereas repeat lengths below do not. This phenomenon has plagued the HD community since the discovery of the gene in 1993. In this thesis, we sought to elucidate the molecular mechanism by which huntingtin becomes toxic at polyglutamine lengths above 37. Using Förster resonance energy transfer (FRET) techniques, we describe an intramolecular proximity between the first 17 residues (N17) and the proline-rich regions, which flank the polyglutamine tract of huntingtin. We report that we can precisely measure differences between the conformations adopted by the huntingtin protein with polyglutamine tracts below and above the pathogenic repeat threshold of 37 repeats. Our data supports the hypothesis that polyglutamine tracts below the pathogenic threshold can act as a flexible hinge allowing the N17 domain to freely fold back upon huntingtin and come into close 3D proximity with the polyproline region. This flexibility is lost in polyglutamine tracts with >37 repeats resulting in a diminished spatial proximity between N17 and the polyproline domain.

abstract: Doctor of Philosophy (PhD)


title: Analytical Probabilistic Models for Evaluating the Hydrologic Performance of Structural Low Impact Development Practices

contributor:
Guo, Yiping
Sarah E. Dickson, Paulin Coulibaly
Civil Engineering

subject: Analytical Probabilistic Models; Low Impact Development Practices; Hydrologic Performance

subject: Environmental Engineering

subject: Hydraulic Engineering

subject: Environmental Engineering

abstract:
Low Impact Development (LID) practices have been increasingly used to mitigate the adverse impacts of urbanization. Reliable methods are in need to provide hydrologic performance assessment of different types of LID practices. The purpose of this thesis is to develop a set of analytical models which can be used to assist the planning and design of commonly used structural LID practices such as green roofs, rain gardens, bioretention and permeable pavement systems.

The analytical LID models are derived on the basis of exponential probability density functions (PDF) of local rainfall characteristics and mathematical representations of the hydraulic and hydrologic processes occurring in association with the operation of LID practices. Exponential PDFs are found to provide good fits to the histograms of rainfall characteristics of five cities located in different climatic zones. The mathematical representations are all physically based and most of the input parameters used in these representations are the same as those required in commonly used numerical models.

The overall reliability of the analytical LID models are tested by comparing the results from these analytical models with results determined from long-term continuous simulations, in addition to that the accuracy of the analytical model for green roofs is also verified against observations from a real case study. The long-term rainfall data from the five cities and a variety of LID practice design configurations are used in the comparisons. The relative differences between the results calculated using the analytical LID models and the results determined from corresponding SWMM simulations are all less than 10%.

The Howard’s conservative assumption is adopted in the development of the analytical models for rain gardens and permeable pavement systems. This assumption results in conservative estimations of the stormwater management performances of these LID practices. Instead of adopting the Howard’s conservative assumption, an approximate expected value of the surface depression water content of a bioretention system at the end of a random rainfall event [denoted as ] is derived and used in the development of the analytical model for bioretention systems. The use of is proven to be advantageous over the use of the Howard’s conservative assumption.

The analytical LID models are comprised of closed-form mathematical expressions. The application of them can be easy and efficient as illustrated in the application examples. For a specific location of interest, with a goodness-of-fit examination of the exponential PDFs to local rainfall data and verification of the accuracy of the analytical LID models, these models can be used as a convenient planning, design, and management tool for LID practices.

abstract: Doctor of Philosophy (PhD)


title: Dynamic Simulation and Control of a Hybrid Coal Gasifier / Steam Methane Reformer System

contributor: Christopher L.E. Swartz, Prashant Mhaskar

subject:
Process Control and Systems
Process Control and Systems

abstract:
Polygeneration plants are proposed as an attractive solution to today’s challenging economic and political climate, whereby fossil fuels (e.g.: coal, natural gas) can be co-processed to obtain multiple products, such as electricity, gasoline and diesel. To this end, this thesis investigates the feasibility of the operation and control of a novel cooling system which incorporates steam methane reformer (SMR) tubes into a gasifier radiant syngas cooler (RSC). This approach capitalizes on available exergy by producing valuable H2-rich synthesis gas (syngas) for liquid fuel production. As the device is still in the conceptual phase, a detailed multi-scale, two-dimensional, heterogeneous model has been developed in prior work to accurately predict the unit’s operation.

A base case design was developed for both counter-current and co-current flow configurations, wherein a PI control structure designed to achieve performance objectives. Key trade-offs were found between the configurations: the counter-current design was more robust and effective in rejecting moderate and severe disturbances, while providing greater cooling duty and natural gas throughput, but at the expense of dangerously high tube wall temperatures, which can greatly reduce tube lifetime. The co-current design operates in a safer temperature range and satisfactorily rejects moderate disturbances, but requires feedforward control to handle extreme gasifier upsets.

An offset-free linear model predictive controller (MPC) was developed for the co-current system to address process interactions. The MPC model was identified from ‘data’ derived from the rigorous plant model, with a Luenberger observer used to estimate and eliminate the plant-model mismatch. MPC offered superior set point tracking relative to discrete-PI control, especially in cases where discrete-PI destabilized the system. Using the co-current design, the flexibility of the device to adjust natural gas throughput based on variations in downstream syngas demand was demonstrated.

abstract: Master of Applied Science (MASc)


title: Complex Dietary Interventions to Slow Rates of Aging

contributor:
Rollo, David C.
Szechtman, Henry
McClelland, Grant
Biology

subject: Aging and Anti-Aging

subject: Complex Dietary Supplement

subject: Motor Cognitive Sensory Function

subject: Free Radicals Oxidative Damage and Mitochondria

subject: Brain Neuroprotection Neurodegenerative Disease

subject: Blood Glucose Cancer p53 and Growth

subject: Behavioral Neurobiology

subject: Biology

subject: Complex Mixtures

subject: Other Nutrition

subject: Systems and Integrative Physiology

subject: Behavioral Neurobiology

abstract: Aging erodes motivation, cognition, sensory modalities and physical capacities, effectively depleting quality of life. Declining sensory, cognitive and motor function are reliable biomarkers of aging and mortality risk. These declines are associated with dysregulation of systemic and cellular processes. We developed a complex dietary supplement (DSP) designed to ameliorate five mechanisms of aging (oxidative processes, inflammation, mitochondrial function, insulin resistance and membrane integrity). Remarkably, normal mice fed the DSP retained youthful functionality into old ages, reflecting slower aging rates. Marked improvements in motor function, memory capacity, spatial learning, muscle strength, visual acuity, olfaction, fecundity and important behavioral functions were observed in aging supplemented mice. Conversely, untreated control animals showed age-related declines in all of the above. Functional improvements were associated with reduced oxidative damage, elevated mitochondrial activity, positive cellular energy balance, improved glucose tolerance, boosted neurotransmitters, greater synaptic density and higher neuronal numbers throughout the brain. A 30% reduction in cancer rates was also documented for DSP treated p53+/- mice. The vast functional benefits greatly exceed the modest longevity extension (11%) in normal supplemented mice. For aging humans, maintaining functionality and performance into later years may provide greater socioeconomic and health benefits than simply prolonging lifespan. Implications of these findings extend to common age-related pathologies including dementia and neurodegenerative diseases, diabetes, cancer, sarcopenia and age-related macular degeneration. Although identifying the role of specific ingredients remains outstanding, results provide proof of principle that complex dietary cocktails can powerfully ameliorate biomarkers of aging and modulate mechanisms considered ultimate goals for aging interventions.

abstract: Doctor of Philosophy (PhD)


title: INVESTIGATING DISEASE RESISTANCE IN EUTREMA SALSUGINEUM & THE ESTABLISHMENT OF A EUTREMA-P. SYRINGAE PLANT PATHOSYSTEM

contributor:
Cameron, Robin
Weretilnyk, Elizabeth A.
Elliot, Marie
Biology

subject:
Eutrema salsugineum
Thellungiella salsuginea
Pseudomonas syringae
defense priming
plant-pathogen interactions
Plant Pathology
Plant Pathology

abstract: Eutrema salsugineum is an extremophile plant native to the Yukon Territory and coastal China. As an extremophile, Yukon Eutrema is tolerant to highly saline, drought conditions and cold temperatures while Shandong Eutrema can survive in highly saline conditions (Griffith et al., 2007; Guevara et al., 2012; Inan et al., 2004). The disease resistance responses of the Yukon and Shandong accessions of Eutrema were investigated to understand how an abiotic stress-tolerant plant responds to biotic stress. A pathosystem was developed using Pseudomonas syringae pv. tomato DC3000 (Pst) to examine Eutrema defense responses. Compared to Arabidopsis (Col-0), both Eutrema accessions exhibited resistance to Pst, with Shandong Eutrema displaying greater resistance than Yukon Eutrema. Resistance to P. syringae pv. maculicola (Psm) was also observed in both accessions. Furthermore, both Eutrema accessions displayed a differential capacity for effector-triggered immunity (ETI). RNA-Seq data of uninoculated Shandong vs. Yukon Eutrema revealed an overrepresentation of defense genes including PR1 (pathogenesis-related1; Champigny et al., 2013). Expression of the Eutrema PR1 ortholog in uninoculated Shandong leaves combined with enhanced resistance to Pst compared to Yukon Eutrema or Col-0 Arabidopsis suggests that Shandong plants exist in a defense-primed state. Resistance to other pathogens such as Pectobacterium carotovorum ssp. wasabiae (Pcw) further supported the hypothesis that Shandong Eutrema is primed for pathogen tolerance. The Eutrema-P. syringae pathosystem will facilitate future studies to understand how Eutrema deals with multiple or concurrent stresses and this knowledge will contribute to efforts to improve tolerance to both abiotic and biotic stress in crop plants.

abstract: Master of Science (MSc)


title: Single Particle TIRF Detection of Bid Molecular Complexes Embedded in Mitochondria-like Supported Lipid Bilayers

contributor:
Fradin, Cécile
Physics and Astronomy

subject:
Single Particle
Fluorescence
TIRF
Bid
Bcl-2 Family of Proteins
Biological and Chemical Physics
Biological and Chemical Physics

abstract: Bid is a member of the Bcl-2 family of proteins, which are known as the regula- tors of apoptosis. Bid recruits Bax, another Bcl-2 family protein, which forms large oligomers that permeabilize the mitochonrdial outer membrane during apoptosis. In this thesis, Bid complexes embedded in a mitochondria-like supported lipid bilayer were investigated using single molecule fluorescence techniques. The bilayer, con- taining a lipophilic tracer, was formed on a mica surface and ATTO647 labelled Bid was added to it. For experiments where the effect of Bax on Bid complexes was investigated, a wild type Bax or a HiLyte488 labelled Bax was added as well. The protein-bilayer sample was imaged using total internal reflection fluorescence (TIRF). The formation of a fluid bilayer was confirmed by the observation of the lateral diffusion of DiD. Single particle tracking of the lipid molecules was used to measure the diffusion coefficent of DiD which was determined to be 2.2μm2 /s. The TIRF images also revealed two populations of Bid complexes, immobile and mobile. The diffusion coefficient of the observed Bid complexes was determined to be about three times slower than that of DiD (0.8±0.5μm2 /s). This provides evidence that mobile Bid is embedded in the bilayer. Image analysis of immobile Bid complexes showed a step-wise decrease in the fluorescence intensity due to photobleaching. The oligomeric distribution of the immobile Bid complexes was determined from the num- ber of steps, which corresponds to the number of particles in each complex. From these distributions it was concluded that the imaged immobile Bid existed mainly as monomers. However dimer and trimer complexes of Bid were also observed. The detected oligomeric distribution was not affected by the presence of either wild type Bax or Hilyte488 Bax. However Bid was imaged for the first time participating in Bax complexes. The acquired results somewhat differ from what had been observed in confocal imaging of the same samples, where mostly larger Bid complexes (dimers and up) were detected. We attribute the difference to the superior sensitivity of the TIRF method presented here.

abstract: Master of Science (MSc)


title: INFLUENCE OF HYDROGEOLOGICAL SETTING ON PEATLAND BURN SEVERITY

contributor:
Waddington, James
School of Geography and Geology

subject:
peatland
wildfire
carbon
boreal
organic soil
hydrogeology
Hydrology
Hydrology

abstract: Organic soil depth of burn in Canadian boreal peatlands cited in the literature generally ranges from 0.05 to 0.10 m despite fire manager reports that suggest higher burn severity (> 0.50 cm) may exist on the landscape. It was hypothesized that hydrogeological setting imposes different landscape patterns of peat bulk density and moisture content leading to greater variability in organic soil burn severity across the landscape than previously thought. To examine this, depth of burn was measured in three peatlands located along a hydrogeological and topographic gradient that were affected by the May 2011 Utikuma Complex forest fire (SWF-057, ~90,000 ha) in Canada’s Western Boreal Plain. The results demonstrate that peatland margins, due to fluctuating water tables, burned significantly deeper (0.25 ± 0.01 m) than the middle (0.06 ± 0.01 m) of peatlands. Additionally, in a coarse textured glaciofluvial outwash, a bog with ephemeral groundwater connections had the greatest depth of burn (0.51 ± 0.02 m) and a low-lying flow-through bog had the lowest burn severity (0.07 ± 0.03 m). An expansive peatland in the lacustrine clay plain showed an intermediate depth of burn (0.16 ± 0.01 m). To further investigate the role of groundwater connectivity in the outwash, GWC and smouldering energy dynamics were modelled at several unburned peatlands across a topographic gradient. It was shown that the peatland with the most groundwater connectivity showed the lowest vulnerability, while the ephemerally perched peatland was the most vulnerable. The peatland at the highest topographic position and least groundwater connection showed intermediate vulnerability. This research indicates that groundwater connectivity and subsequent influence on water table fluctuations in peatland margins can have a dominant control on soil carbon combustion, it is therefore suggested that a hydrogeological ‘template’ be used to identify deep burning ‘hotspots’ on the landscape a priori, so as to increase the efficacy of wildfire mitigation strategies.

abstract: Master of Science (MSc)


title: Characterization of xZnf131 in the early development of Xenopus laevis

contributor:
Daniel, Juliet
Marsden, Mungo
Campos, Ana R.
Biology

subject:
Xenopus
POZ-ZF
Znf131
Development
Gastrulation
Neurulation
Biology
Developmental Biology
Biology

abstract:
Early Xenopus laevis development involves highly complex morphogenic movements. Two key movements are gastrulation, which establishes germ layer spatial arrangement, and neurulation, which results in the folding and closure of the neural tube. Multiple signaling pathways are involved in regulating cell adhesion, migration, shape and polarity during these processes to ensure normal development. Two of the most characterized pathways are the canonical and non-canonical Wnt pathways. However, the roles of all the individual molecules involved are not fully understood. In this thesis I provide initial characterization of the POZ-ZF transcription factor xZnf131. Znf131 is a transcriptional activator and its binding partner Kaiso negatively regulates this function. Since Znf131 and Kaiso display antagonistic roles and Kaiso mediates Wnt signaling and morphogenesis during Xenopus gastrulation and neurulation I hypothesize that xZnf131 is also required to regulate morphogenesis during these key developmental events.

Like other POZ-ZF proteins, xZnf131 contains an amino-terminal POZ domain and a carboxy-terminal ZF domain comprised of five zinc fingers. xZnf131 is continuously expressed through early Xenopus development but was spatially localized to the dorsal and anterior structures of the embryo, notably the neural plate. Morpholino oligonucleotide (MO) knockdown of xZnf131 resulted in severe defects in notochord and neural plate formation, with abnormal cell morphology, typical of non-canonical Wnt misregulation. Interestingly, xZnf131 overexpression produced phenotypes very similar to xZnf131 knockdown suggesting that xZnf131 protein levels need to be tightly maintained to regulate the correct/normal morphogenic movements during Xenopus gastrulation and neurulation.

Our findings indicate that xZnf131 plays a role in the morphogenic movements during Xenopus gastrulation and neurulation. Our data provides a useful foundation for future experiments to elucidate the biological mechanism of xZnf131 action during these key developmental processes.

abstract: Master of Science (MSc)


title: Early postnatal expression of proteins associated with inhibitory synapses in the auditory brainstem

contributor:
Gillespie, Deda
Roger Jacobs, Dan Goldreich
Neuroscience

subject:
synapse
auditory brainstem
lateral superior olive
development
vesicular transporter
circuit refinement
Neurosciences
Neurosciences

abstract:
The lateral superior olive (LSO) is a binaural nucleus that is critical for azimuthal sound localization. Bipolar principal cells of the LSO compute interaural level differences (ILDs) by comparing converging excitatory and inhibitory inputs driven by either ear. More specifically, this computation relies on integrating excitatory inputs from the ipsilateral cochlear nucleus with inhibitory, GABA/glycinergic inputs from the medial nucleus of the trapezoid body (MNTB), which are driven by sound originating at the contralateral ear. In order to reliably compute ILDs, the converging inputs must represent sounds of the same frequency. This specificity emerges during the first few weeks of postnatal life in rats as a result of functional and anatomical refinement. Interestingly, significant refinement of this auditory circuit occurs in the absence auditory experience. We focused on changes in the subcellular location of MNTB inputs and the expression of vesicular proteins before hearing onset.

The subcellular distribution of inputs onto a neuron heavily influences synaptic integration and the mature distribution likely emerges during a period of circuit refinement. Little is known about how the inputs are distributed onto LSO principal cells and how the mature distribution is achieved. We studied the distribution of inhibitory inputs onto LSO neurons and found that significant re- distribution occurs before hearing onset. The mechanisms underlying the refinement of the inhibitory MNTB projection are not well understood but could be related to the transient co-transmission of the excitatory neurotransmitter glutamate. We studied the expression of vesicular proteins that may regulate the release of GABA/glycine and glutamate at the immature MNTB terminal. We found that MNTB terminals transiently express two Ca++ sensors, which may be associated with the different release properties for GABA/glycine and glutamate. Lastly, we asked one specific example of what controls the expression and sorting of vesicular proteins at the immature MNTB terminal.

abstract: Doctor of Philosophy (PhD)


title: A Metagenomic Analysis of Ancient Sedimentary DNA Across the Pleistocene-Holocene Transition

contributor:
Golding, GB
Poinar, HN
Xu, JP
Biology

subject:
Metagenomic
Ancient DNA
Pleistocene
Holocene
Climate Change
Yukon
Biology
Biology

abstract: Ancient DNA has the power to elucidate ecological and evolutionary relationships that were previously only quantifiable by proxy. This work details both a metagenetic and a targeted metagenomic study of ancient sedimentary DNA. By using DNA to investigate the plants and animals present in twelve different time points, we describe the nature of the ecological change over the Pleistocene-Holocene transition. We show that as the stability of the habitat degraded due to climate change, the dominant plant communities exhibited a shift from functional groups such as forbs to shrubs and trees. As this cascading change consequently affected the animal communities, we demonstrate the decline, extinction, and replacement of a variety of megafaunal species and mammoths. As well, we provide a proof-ofconcept for the targeted oligonucleotide enrichment for ancient sedimentary DNA. By processing the same DNA extracts with targeted enrichment, we show that metagenomic soil DNA can provide the same taxonomic fingerprint unique to each time period even using different genetic loci. This unique pattern can be used as a reference in future studies. Although the oligonucleotide baits did not yield the composition of taxa that we expected, the oligonucleotide baits did increase the eukaryotic fraction of DNA extracts by up to 50%. Overall, this technique is open to further study and has fantastic potential to redefine the metagenomic work of ancient DNA soil cores.

abstract: Master of Science (MSc)


title: The Role of the YjeQ GTPase in Bacterial Ribosome Biogenesis: Function of the C-terminal Zinc-finger Domain

contributor:
Ortega, Joaquin
Brown, Eric
Biochemistry and Biomedical Sciences

subject:
YjeQ
RbfA
ribosome assembly
GTPase
30S subunit
bacterial ribosome
Biochemistry
Structural Biology
Biochemistry

abstract: Our understanding of the mechanism of ribosome assembly in bacteria is still in its infancy. Work from our laboratory and others have recently established that some protein assembly factors assist the assembly process at its late stages, mediating the correct folding of the functional core of the 30S and 50S subunits. The GTPase YjeQ is an assembly factor that displaces the upper domain of h44 of the mature 30S subunit upon binding, inducing a distortion in the decoding center. We hypothesized that the displacement of h44 is caused by the zinc-finger domain of YjeQ and mediates the release of RbfA, another assembly factor involved in 30S subunit maturation. To understand how the zinc-finger domain of YjeQ implements the functional interplay with RbfA, we constructed several deletion mutants of the domain. We found that the zinc-finger domain of YjeQ was required to bind the 30S subunit, but not the C-terminal extension (CTE) of the domain. The CTE was necessary for stimulation of GTPase activity upon binding to the 30S subunit and removal of bound RbfA from the 30S subunit. The data presented here suggests that the zinc-finger domain is essential for YjeQ to bind the 30S subunit and to implement the functional interplay with RbfA. Ongoing structural studies of the complex formed by the YjeQ CTE variant and the 30S subunit will provide a three dimensional view of the conformational changes that occur to implement the functional interplay between YjeQ and RbfA at the late stages of 30S subunit assembly.

abstract: Master of Science (MSc)


title: Effect of Dietary Protein Intake on Body Composition Changes During Intense Training in an Energy Deficit

contributor:
Phillips, Stuart M
Gibala, Martin
Bray, Steven
Kinesiology

subject:
protein
high-intensity training
energy deficit
high protein
resistance exercise
HIIT
Exercise Science
Exercise Science

abstract: What a ride it has been. The ups and downs of the McMaster graduate program has been a sweet one. It has been a pleasure working with the Exercise Metabolism Research Group for the past 2 years, and I will miss being around the work that goes on in the trenches around the lab. I have leaned on many people for all types of guidance through this journey, and would like to thank everyone for their unprecedented support. I have grown as a person and student and will use everything I have learned at this fine establishment I’m sure at one point or another along the great path of life. I must thank my amazing parents, family, friends and of coarse Ashley for putting up with my work ethic throughout my studies; the long days that I would go missing. Without their support none of this would have been possible. I have to specially mention Melanie Wolfe for recommending myself, and ultimately Stu Phillips for presenting this opportunity that is coming to a close. I have had great senior support from Cam Mitchell, Tyler Churchward-Venne, Todd Prior and Michaela Devries in putting this document together, and would not be submitting this without their selfless assistance. It’s been a journey getting to this point, but I wouldn’t change it for the world, to the next chapter in life, cheers and God Bless.

abstract: Higher dietary protein intake, greater than the Recommended Dietary Allowance (RDA; 0.8 g protein/kg/d), coupled with resistive exercise has been shown to aid in preservation of muscle mass during hypocaloric diet-induced weight loss. We examined the impact of dietary protein supplementation at two levels (1.2 and 2.4 g/kg/d) on body composition during a 4wk hypocaloric dietary intervention that included 6d/wk of high intensity resistance exercise and interval training. In a single blind study, forty young men consumed 33±1.1 kcal/LBM (~40% reduction versus estimated energy requirements), and were randomly assigned to a group that consumed either 1.2g/kg/d protein or 2.4g/kg/d. Body composition was determined using DXA, Bod Pod, and Bio-impedance pre- and post-intervention to derive a 4-compartment model for body composition. Both groups retained lean mass (LM), but retention was greater in the higher protein group (p

abstract: Master of Science (MSc)


title: Insertion/deletion (Indel) Based Approach for the Detection of Escherichia coli O157:H7 in Freshwater Environments

contributor:
Schellhorn, Herb E.
Gupta, Radhey S.
Kolasa, Jurek
Biology

subject:
Escherichia coli
O157:H7
pathogen detection
qPCR
environmental samples
indel
Biology
Biology

abstract: Though pathogenic strains represent a small portion of the total variety of existing Escherichia coli strains, they contribute extensively to human morbidity and mortality. Disease outbreaks caused by enterohaemorrhagic E. coli of the serotype O157:H7 and the “Big Six” serotypes (i.e., O26, O45, O103, O111, O121 and O145) have driven the development of assays for pathogen detection. From culture-based assays requiring several days for confirmation of target organisms, to quantitative PCR (qPCR) tests that provide pathogen identification in several hours’ time, the sensitivity, specificity and speed of bacterial diagnostics have seen improvements that increased the efficacy of assays used to detect pathogens at clinically relevant levels. One relatively unexplored field of diagnostics is the use of conserved signature insertion/deletions (CSIs) as stable genetic markers for pathogen detection. This thesis presents two qPCR assays that target an E. coli O157:H7-specific insertion in a CSI. In a more preliminary study, an EvaGreen-based qPCR assay was developed that had a detection limit of 16 E. coli O157:H7 genome equivalents. An improved format of the O157:H7-specific CSI assay, using TaqMan probes, was later established. TaqMan probes are sequence-specific, while DNA-intercalating EvaGreen dye is sequence-independent. Though the TaqMan probe-based assay had a higher detection limit of 100 genome equivalents, the assay maintained detection sensitivity in presence of genetically similar (E. coli K-12) and dissimilar (fish sperm) DNA in excess amounts (1000-fold and 800-fold excess of target DNA, respectively), demonstrating its potential for pathogen detection in environmental samples where the presence of background flora may influence detection. These assays thus represent an exploration into the use of CSIs as diagnostic tools. This thesis also provides a guide for future developments of pathogen detection using CSIs, such as those that may be present in toxigenic species of Cyanobacteria and human pathogens, including Vibrio and Campylobacter.

abstract: Master of Science (MSc)


title: Primary Cilia Dynamics, Morphology and Acetylation are Abnormal in Huntington’s Disease Cell Models

contributor:
Truant, Ray
Guarne, Alba
Burrows, Lori
Biochemistry and Biomedical Sciences

subject:
Primary Cilia
Huntington's disease
Huntingtin
Acetylation

abstract: The primary cilium is a singular signaling organelle found on most mammalian cell types. Dysfunction of the primary cilium or associated structures form a group of genetic disorders called ciliopathies. Recently, Huntington’s disease (HD), a monogenetic neurodegenerative disorder, was classified, at least in part, as a ciliopathy. How the primary cilium contributes to the pathogenesis of HD is the focus of this work. We demonstrate that huntingtin localization to the basal body or primary cilium is dependent on the phosphorylation status of serine residues 13 and 16. Furthermore, we demonstrate that, compared to controls, HD cell models have an increased number of cells with a primary cilium and that these cells have higher presence of huntingtin within the ciliary compartment. The primary cilia that form in HD cell lines demonstrate abnormal dynamics and morphology with bulging tips, characteristic of defective retrograde trafficking. We also demonstrate that alpha tubulin acetyltransferase 1 (αTAT1) expression and localization is increased in the primary cilium of HD cell lines. Subsequently, the primary cilium of HD cell lines are highly acetylated when compared to controls. These data support that primary cilia structure, ciliogenesis and ciliome are altered in HD.

abstract: Master of Science (MSc)


title: Implementation of Sampled-Data Supervisory Control

contributor:
Leduc, Ryan
Computing and Software

subject: DES, TDES, Discrete Event Systems, Supervisory Control, Automata, VERILOG, FSM, Moore Machines, System Model

abstract:
This thesis focuses on the issues related to the implementation of theoretical timed discrete-event systems (TDES) supervisors. In particular, we examine issues related to implementing TDES as sampled-data (SD) controllers, which were introduced by Wang and Leduc. An SD controller is driven by a periodic clock and sees the system as a series of inputs and outputs. On each clock edge (tick event), it samples its inputs, changes state, and updates its outputs.

We first introduce the sampled-data setting from Wang, and then define the sampled-data properties he identified, including the SD controllability property. We then introduce Wang's formal representation of an SD controller as a Moore synchronous finite state machine (FSM). We then discuss Wang's modular and centralized translation method.

We next introduced new modular results for the SD controllability point 3.1, SD controllability point 3.2, SD controllability point 4, activity loop free and S-singular prohibitable behaviour that allow one to verify the properties using only a portion of the system, instead of having to construct the entire system model. This should allow faster verification times as well as allow larger systems to be verified. We then introduce for the first time algorithms to verify Wang's CS Deterministic and non self-loop ALF properties.

The remainder of the thesis focuses on developing algorithms and software to automatically convert a TDES first into an FSM, and then into a VERILOG module. VERILOG is a hardware description language which allows our FSM to be compiled and implemented on digital logic devices such as an FPGA.

We then tested our method by modelling a simple door locking system as TDES, checking that the system satisfies the required sampled-data properties, and then translating the result into VERILOG. The above algorithms and methods have all been implemented as a part of the graphical DES research tool, DESpot.

abstract: Thesis

abstract: Master of Computer Science (MCS)


title: Awareness of the Evidence for Practice of Registered Massage Therapists in Ontario

contributor: Clinical Epidemiology/Clinical Epidemiology & Biostatistics

subject:
Evidence informed practice
massage therapy
sources of information
awareness of evidence

abstract:
Background:  Evidence-informed practice (EIP) is part of a healthcare ethos, in which practitioners apply evidence together with their expertise contextualized by the unique values of the patient.  Studies about EIP focus on attitudes or confidence related to EIP. Individuals’ abilities to assess their own knowledge or performance are low.  Therefore, a positive rating of attitude or confidence does not likely portray accurately the EIP knowledge or ability of the practitioner.  It was hypothesized that awareness of evidence might be a more accurate measure.
Objective: This study sought to understand registered massage therapists’ (RMTs) awareness of the current evidence for practice and to identify sources of information that inform that awareness.
Methods: An online questionnaire-based mixed-methods cross-sectional study was conducted.  Ontario RMTs were invited to participate.  This report focuses on the results of the quantitative analysis.
Results: In total, 1,762 questionnaires were included; a 16.9% response rate.  The mean awareness score was 9.4 ± 7.2.  A multiple regression showed four factors that explained 4% of the variation seen in the awareness score: membership in the professional association (RMTAO), EIP attitude score, post-graduate education, and home-based practice.
Of seven sources of information provided, respondents rated cumulative professional experience as most important, followed by recent research studies and education. Cumulative professional experience also rated as most frequently used, followed by other RMTs and education.
Conclusions: This study investigated the level of awareness of evidence of RMTs. The results of the awareness score showed opportunity for improvement and require further investigation.  Future research should explore other factors, which may show a better model of predictability of the awareness score.  It is proposed that awareness of the evidence for practice might be a better predictor of use of evidence in practice than self-reported attitude or capacity but further research is needed.

abstract: Thesis

abstract: Master of Science (MSc)


title: Investigation into the role of the hexosamine biosynthesis pathway in hyperglycemia-induced atherosclerosis

contributor:
Werstuck, Geoff
Biochemistry and Biomedical Sciences

rights: An error occurred getting the license - uri.

subject:
Diabetes
Atherosclerosis
Hexosamine biosynthesis pathway
ER Stress

abstract: Diabetes mellitus dramatically increases the risk for atherosclerotic cardiovascular disease. It has been established that chronic hyperglycemia promotes an increase in glucose flux through the hexosamine biosynthesis pathway (HBP). Central to this pathway is glutamine:fructose-6-phosphate amidotransferase (GFAT), the rate-limiting enzyme controlling the conversion of glucose to glucosamine. We have shown that glucosamine is a potent inducer of endoplasmic reticulum (ER) stress, which is characterized by the accumulation of misfolded proteins in the ER. Chronic ER stress can initiate a multifaceted response that results in lipid accumulation, inflammation and apoptosis: the hallmark features of atherosclerosis. We hypothesized that conditions of chronic hyperglycemia, associated with diabetes mellitus, can accelerate the development of atherosclerosis by a mechanism that involves increased HBP flux resulting in glucosamine-induced ER stress and the subsequent activation of pro-atherogenic pathways. In support of the hypothesis we found that glucosamine-supplemented apoE-/- mice had elevated levels of ER stress and atherosclerosis. Mechanistically, our data showed that glucosamine induced ER stress by interfering with the lipid-linked oligosaccharide biosynthesis pathway and protein N-glycosylation. These findings support a model by which conditions of hyperglycemia promote vascular complications through a glucosamine-intermediate.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract: Diabetes mellitus dramatically increases the risk for heart attacks and strokes. High blood glucose is utilized in cells through its conversion into metabolites, such as glucosamine. We hypothesized that conditions of high blood glucose can led to an increase in intracellular glucosamine which can initiate pathways involved in accelerating atherosclerosis. Our results show that this is possible in both human cells and mice.


title: Determination of Metamorphic Grade for Two Formations of the Huronian Supergroup: Whitefish Falls Area, Ontario

contributor:
Schwarcz, H.P.
Geology

subject: chemical petrographic metamorphism minerology

abstract:
Samples from the Whitefish Falls Area were examined
petrographically and chemically to determine the regional
grade of metamorphism. Mineralogy from the Lorrain formation
(quartzities) and Gowganda Formation (argillites) were
apparently incongrous. The resolution of this problem formed
the major part of the study.

Mineralogically the quartzites contained a kyanitequartz
paragenesis with a subordinate kyanite-chloritoidquartz
paragenesis. The argillites showed a chlorite-biotite
-plagioclase-calcite-quartz paragenesis with only minor
epidote present. From textural evidence possible reactions
were deduced which were used to set the upper and lower limits
for pressure and temperature. These boundaries were 470°C
and 3.9 kb., lower limit and 550°C with a variable pressure
for the upper limit.

Chemically, whole rock analysis was used to determine
the parameters for various chemographic diagrams. AFM, ACF
and AKF plots for the argillites showed a very restrictive
composition which excluded the almandine field and promoted
the biotite field. The bulk composition of the argillites
was cited as the main reason for the inhibition of high
grade index minerals, thus appearing to be lower grade than
their quartzite counterparts. AFM and AKF diagrams for the
quartzites verified their mineralogy and proved their high
grade nature.

abstract: Thesis

abstract: Bachelor of Science (BSc)


title: A Computational Benchmark Study of Forced Convective Heat Transfer to Water at Supercritical Pressure Flowing Within a 7 Rod Bundle

title: Submission to the GIF SCWR Computational Benchmark Exercise

contributor:
Novog, David
Engineering Physics

subject:
CFD
Heat Transfer
Fluid mechanics
STAR-CCM+
Turbulence Modelling
SCWR

abstract:
The  research  and  development  effort  for  the  next  generation  of  nuclear  power
stations is being coordinated by the Generation IV International Forum (GIF). The
supercritical water reactor (SCWR) is one of the six reactor technologies currently
being pursued by the GIF. The unique nature of supercritical water necessitates
further  examination  of  its  heat  transfer  regimes.  The  GIF  SCWR  blind
computational benchmark exercise is focused on furthering the understanding of
the heat transfer to supercritical water as well as its prediction.
A  methodology  for  computational  fluid  dynamics  (CFD)  simulations  using
STAR-CCM+  9.02.005  has  been  developed  for  submission  to  the  GIF  SCWR
computational  benchmark  exercise.  The  experiments  of  the  GIF  SCWR
computational  benchmark  exercise  were  those  conducted  by  the  Japan  Atomic
Energy Agency (JAEA). They are of supercritical water flowing upward in a 7
rod bundle. Of the three experimental cases there are (i) an isothermal case, (ii) a
low enthalpy, low heat flux case and (iii) a high enthalpy, high heat flux case. A
separate  effects  study  has  been  undertaken  and  the  SST  turbulence  model  has
been chosen to model each of the three experiments. A near wall treatment that ensures  a  y+<0.09  has  been used for both  of  the heated  cases and  a  near  wall
treatment  that  ensures  a  y+<0.53  has  been  used  for  the  isothermal  case.  This computational approach was determined to be the optimal choice which balances
solution accuracy with computation time.
Final  simulation  results  are  presented  in  advance  of  the  release  of  the
experimental results in June 2014.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: Analysis of Multilayer sandwhich beams and Multipier shear walls

contributor:
Robinson, H.
Engineering

subject:
multilayer sandwich beams
multipier shear walls
symmetrical loading
influence of normal deformation

abstract: Investigation of simply supported Multilayer sandwich beams with symmetrical loading and of Multipier shear walls with arbitrary horizontal loadings. The analysis contains the influence of normal deformation of the layers and piersrespectively.

abstract: Thesis

abstract: Master of Engineering (ME)


title: Oxidation and Decarburization Kinetics of Iron-Carbon Alloys in Carbon dioxide - Carbon Monoxide Atmospheres

contributor:
Smeltzer, W. W.
Metallurgy

subject: oxidation decarburization carbon-monoxide

abstract:
In this thesis, the results of oxidation and decarburization
experiments with pure iron-carbon alloys over the temperature range
800 - 950ºc, and in atmospheres of varying carbon monoxide - carbon
dioxide ratio are reported. Most of the experimental work is concerned
with a 1.065 weight percent carbon alloy at temperatures where austenite
is the stable phase. Complex kinetic behaviour was observed for this
alloy in the range 10 - 100 volume percent carbon dioxide. An analysis
is given which in turn associates the kinetics with a pure diffusion
controlled decarburization model and a pure surface controlled decarburization model. The latter best represents the interaction of the
decarburization mechanism with the scaling process on Y - iron.
Metallographic evidence is provided where possible in support of the
results of the afore-mentioned analysis. Mathematical relations are
introduced which attempt to describe qualitatively the kinetics of the
carbon alloys in all the atmospheres employed. A statement is made as
to the applicability of the model to carbon steels in general at
temperatures where austenite is the stable phase and where the atmospheres employed are of various carbon monoxide - carbon dioxide ratio.

abstract: Thesis

abstract: Master of Science (MS)


title: DATA-DRIVEN MODELING FOR QUALITY CONTROL IN CHEMICAL PROCESSES

contributor:
Mhaskar, Prashant
Chemical Engineering

abstract:
This thesis considers the problem in data-driven modeling for quality control of complex chemical processes characterized by nonlinearity and time-varying dynamics over a wide range of operating conditions. The critical steps in data-driven modeling for quality control, such as data pretreatment, online inferential model maintenance and quality control mechanism designs, are investigated separately in previous studies, which calls for holistic research on those topics.

In the initial phase of this research, the missing measurement problem in data-driven modeling is addressed by two developed probabilistic partial least squares (PPLS) methods. In the expectation-maximization (EM) based PPLS (EM-PPLS), the convergence properties for model parameters and estimated values of missing measurements are proved in explicit forms, enabling effective and robust application. In parallel, full Bayesian treatment is employed in the Bayesian inference based PPLS (BI-PPLS), to substantially reduce the computational complexity in latent variable selection in the PPLS model. In both proposed PPLS methods, data-driven model generation and missing measurement estimation can be carried out concurrently along with the uncertainty handling in process measurements through a probabilistic strategy.

Next, the degradation problem in the online implementation of the data-driven inferential models is addressed. The discrepancy between the actual model parameters in the data-driven model and filtered model parameters by Kalman filter is calculated and utilized to derive a model mismatch index, decomposition of which can further lead to identification of leading abnormal model parameters in the data-driven model. With the developed model mismatch index, an online model update strategy is developed to maintain the data-driven inferential model online.

Finally, a predictive controller based on multiple data-driven dynamic and inferential models is designed to control the final product quality in the batch processes. The entire batch is divided into several modeling phases based on the availability of intermittent quality measurements, in which local dynamic models are identified using weighted autoregressive exogenous (ARX) models. Meanwhile, multiway PLS (MPLS) models are also constructed to predict the quality at batch termination given the intermittent quality measurements at the initiation of each modeling phase. The data-driven models are integrated within model predictive control (MPC) framework to control the final product quality in Penicillin fermentation process with the consideration of causality relationships between the future inputs and final product quality.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: Flexible Multiple Description Lattice Vector Quantizer with General Number of Descriptions

contributor:
Dumitrescu, Sorina
Electrical and Computer Engineering

subject:
Multiple description coding
lattice quantization
high resolution analysis

abstract:
This thesis addresses the design of multiple description lattice vector quantizer (MDLVQ) with a general number L of descriptions, L >= 3.
In the previous work on MDLVQ with L>= 3, once the central and side lattice codebooks are fixed, the decoding quality is determined for all numbers k of received descriptions. Therefore, it is not possible to achieve tradeoffs between the quality of reconstruction for different values of k, 1<= k <= L-1.

In order to overcome the above drawback, we propose two flexible MDLVQ schemes for L >= 3. Our first design employs a different reconstruction method than in prior work and a heuristic index assignment algorithm, which uses L-2 parameters to control the distortions for 2 <= k <= L-1. Experimental results for the cases L=3 and L=4 show that significant tradeoffs are achieved by controlling the parameters mentioned above.
Our second design is based on a structured index assignment. We start with the case L=3 and then generalize the index assignment to any L >= 3. The structured index assignment is able to control the tradeoff by adjusting the sizes of some L-1 subsets of side lattice points. Another important contribution of the thesis is the derivation of analytical expressions of the distortions for the structured index assignment, under the high resolution assumption. These expressions show that a wide range of distortion values can be achieved.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: Aerodynamic excitation of the diametral modes of an internal axisymmetric cavity

contributor:
Ziada, Samir
Mechanical Engineering

subject:
aerodynamic excitation
diametral acoustic modes
axisymmetric free shear layer

abstract:
The aerodynamic excitation of the diametral acoustic modes of an
axisymmetric cavity-duct system is investigated experimentally. The change experienced by the acoustic diametral modes with the increase of the mean flow Mach number is investigated numerically. The first objective of this research is to examine the ability of the axisymmetric free shear layer forming along the cavity mouth to excite the asymmetric diametral modes which do not have preferred azimuthal orientations. The dependency of the system aeroacoustic response on both the cavity length and its depth is investigated to determine the limitations imposed by the relative dimensions of the cavity on the excitation process. The azimuthal behaviour of the self-excited diametral modes is also
characterized.

 An experimental set-up is designed to ensure the coincidence of the
frequencies of the shear layer oscillation with the acoustic resonance
frequencies. The selection of the test section dimensions is based on finite
element simulation of the acoustic diametral modes for several geometries. To simulate the diametral modes at different flow Mach numbers, a finite difference code is developed based on a two-step computational aeroacoustic approach. This approach allows the simulation of the acoustic field, taking into account the convection effect of the mean flow.

The experimental results show that the diametral modes are very liable to be self-excited when the mean flow Mach number is higher than 0.1. The level of acoustic pressure during the diametral mode resonance increases rapidly with the increase of the ratio of the cavity depth, d, to the pipe diameter, D. However, the maximum acoustic pressure during each resonance decreases with the increase of the ratio of the cavity length, L, to the pipe diameter, D. The selfexcitation of the diametral modes is sustainable with d/D as small as 1/12. Further reduction in this ratio may result in complete suppression of the resonance. For deep cavities, d/D>3/12, the first and second diametral modes are more liable to excitation than the higher order modes. This is attributed to the fact that the low order modes have relatively higher radial acoustic particle
velocity amplitude at the cavity mouth compared to the higher order ones. For d/D=l/12, the higher order modes have relatively higher radial acoustic particle velocity amplitude and consequently their tendency to be self-excited increases. For long cavities, L/D>2/3, the duct longitudinal acoustic modes start to be excited and become more dominant as the cavity length is further increased. The excitation mechanism of these longitudinal modes has not been investigated in this work since sufficient details already exist in the literature.

The azimuthal behaviour of the diametral modes is characterized for all the tested cases. For short cavities, the diametral modes are classified as spinning modes; while for long cavities, L/D> 1/2, the orientation of the mode changes randomly over time. Small imperfections in the axisymmetric geometry result in what is described as partially spinning modes. An analytical model is developed to describe quantitatively the spinning behaviour of the diametral modes. The free shear layer and the diametral modes are found to be fully coupled in the azimuthal direction. The random behaviour of the diametral modes in the case of long cavities is attributed to the increase of randomness in the turbulent shear layer

The numerical simulations show that the diametral modes experience
considerable changes with the increase of the mean flow Mach number. At the cavity mouth, both the amplitude and phase distributions of the acoustic particle velocity are altered with the increase of the Mach number. This demonstrates the importance of considering the effect of the mean flow on the acoustic power production process. Moreover, the resonance frequency of the diametral modes decreases with the increase of the Mach number.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: EXAMINING PATIENT-PREFERRED ATTRIBUTES TO ENCOURAGE MENTAL HEALTH TREATMENT INITIATION AND SUSTAINED ENGAGEMENT: RESULTS FROM TWO DISCRETE CHOICE CONJOINT EXPERIMENTS

contributor:
Christensen, Bruce
Psychology

subject:
early intervention
discrete choice conjoint experiments
latent class analysis
patient preferences
mental health services
randomized first choice simulations

abstract:
PREFACE: The purpose of this Master’s thesis was to determine which attributes of an early intervention (EI) mental health service would encourage treatment initiation and sustained engagement. This research was motivated by the bourgeoning interest in patient-centered care, particularly the incorporation of patient preferences into service design and implementation. Additionally, the research was inspired by the use of marketing research methodology in healthcare. Two conjoint surveys were formulated with the purpose of asking two questions: what EI service attributes will increase the likelihood of someone (1) initiating contact with an EI service and attending their first appointment, and (2) remaining engaged in treatment. A literature search determined which attributes would be the most relevant and important for conceptualizing an EI service. These attributes were narrowed down with the help of focus groups, key informant interviews, the expertise of the authors, and in the case of the second survey, was also informed by the first survey’s results. Each attribute was assigned four levels and these multi-level attributes were formulated into the two aforementioned surveys that were completed by mental health patients, their families, and mental health professionals.
Chapter 1 of this thesis contains a short overview of the research literature investigating the benefits of EI services, some of the reasons why many patients may not receive such services, and some potential strategies to enhance patients’ initial contact and ongoing engagement with such services. In particular, the central tenet of this thesis is that patient engagement with EI services will be enhanced if service design considers and incorporates the preferences of patients and their families with regard to the attributes that characterize the service and its delivery. This hypothesis is explored using discrete choice conjoint experimental (DCE) methods to identify important service attributes regarding patient initiation and engagement. Given that DCEs are the central methodology of this thesis, Chapter 1 also includes an introduction to these methods and their unique benefits. Each of these service attribute questions posed above is addressed in a separate survey and experiment. Therefore, the rationale, methods, results and conclusions of each experiment are described in separate chapters (Chapters 2 & 3). It should be noted that these two chapters are written in the form of stand-alone scientific reports, each of which is about to be submitted for publication to peer-reviewed journals. Finally, the thesis concludes with a General Discussion (Chapter 4), which attempts to frame the two studies, and this line of inquiry more generally, in the broader research literature and highlight their clinical and policy implications. It should also be noted that, given that there exists substantial conceptual overlap between the two experiments and the main issues described in both the General Introduction and General Discussion, the reader may encounter some repetition throughout the thesis.

abstract: Mental illness places a large burden on individuals and society-at-large, a problem that becomes much worse the longer it is left untreated. Early intervention (EI) can mitigate this burden; however, those experiencing emerging mental illnesses often do not seek help promptly. Patient-centered care, such as shared-decision making models of mental healthcare, may reduce barriers to treatment. A central tenet of patient-centered care is that patient engagement and service utilization increases when patient preferences are incorporated into clinical services. In the current thesis, discrete choice conjoint experiments (DCE) were used to elicit the preferences of patients and their families, as well as the hypothesized preferences of patients according to mental health professionals, in two surveys. The first survey aimed to identify the attributes of an EI service that would encourage people experiencing psychiatric symptoms to initiate contact with a service and attend their first appointment (Chapter 2). The second survey sought to determine which service attributes would encourage someone to remain engaged with mental health treatment (Chapter 3). Both surveys used Latent Class Analysis to segment the study populations into identifiable subgroups based on shared preferences, and Randomized First Choice simulations to predict which service delivery model each of these identified groups would most likely use. The results of these studies have several implications for current and future mental health services. Effective EI mental health services should include rapid access to services, a range of treatment options, and effective crisis response. Moreover, future DCE studies should focus on replicating these results using more heterogeneous samples and improving DCE methods.

abstract: Thesis

abstract: Master of Science (MSc)


title: Lipid Metabolism of Primary Cultures of Aortic Smooth Muscle Cells

contributor:
Bell, F.P.
Biochemistry

subject:
smooth muscles cells
sera tests

abstract:
Smooth muscle cells from pig aortic media were grown in tissue
culture, in medium containing 10% calf serum. Lipid biosynthesis from
radioactive substrates 1-¹⁴C-acetate, U-¹⁴C-D-glucose, 1-¹⁴C-oleic acid
and ³²P-phosphoric acid was measured. In addition, the influence of
various sera, including pig serum, normolipemic human serum (NLHS), and hyperlipemic human serum (HLHS) on lipid biosynthesis from acetate and phosphoric acid was studied

Compared to calf serum, all three test sera caused a stimulation of
lipid synthesis in the lipid classes, phospholipid (PL), free fatty acids
(FFA), triglycerides (TG) and cholesterol esters (CE), and an inhibition
of cholesterol plus diglyceride (S + DG) synthesis. The extent of stimulation was least for pig serum and greatest for HLHS; the inhibition of
S + DG was greatest for HLHS and least for pig serum. It was noted that
the HLHS stimulation of CE synthesis was proportionately greater than the
stimulation of the other lipid classes and that the HLHS inhibition of
S + DG was significantly greater than that seen with the other test sera.

The morphology of cultured aortic smooth muscle cells  grown in 10%
calf serum and 10% HLHS was examined by means of scanning and transmission electronmicroscopy. It was observed that HLHS caused degenerative alterations in the morphology of the cultured smooth muscle cells, such as an abundance of lipid droplets and  cellular debris. The implications of these results in relation to the development of atherosclerosis are discussed.

abstract: Thesis

abstract: Master of Science (MS)


title: The Realization of Narrow Band-Pass characteristics Using Sampled Data Filters

contributor:
Haykim, S.S.
Electrical Engineering

subject:
realization
narrow band-pass filters
comparison
3 channel sample data filter
quadrature modulation

abstract: Pages 42, 63, 69, 71-72, 77, 87, 90, 93-94, and 97 had titles that were cut off in the scanning process. The administrator uploading this file re-wrote them on the bottom of each page.

abstract:
This thesis presents the results of an investigation of an
alternative technique for the realization of narrow band-pass filters.
This technique uses N parallel connected RC time-varying networks.
A comparison of the performance of the 3-channel sampled data filter
and one using the technique of quadrature modulation is made with
respect to overall system performance.

Excellent agreement between the theoretical and experimental
results are obtained for the band-pass characteristics. Design criteria
are also presented in order to approach the ideal operation of an N-path
sampled data filter.

abstract: Thesis

abstract: Master of Engineering (ME)


title: Adjuster Rod Design in a CANDU Reactor and Flux Distributions Due to an Arbitrary Source of Neutrons

contributor:
Trojan, O.A.
Akhtar, P.
Engineering Physics

subject:
tube thickness
Bruce B adjuster rods
SUPERCELL method
total reactivity
flux distributions

abstract: This submission is officially titled as a project. The author has also produced a second project relating to the same topic, titled "Part B: Power Transient in a CANDU Reactor"

abstract: This report consists of two separate studies. The first part deals with the calculation of the tube thickness of the Bruce B adjuster rods. The incremental cross-section for four tube thicknesses were obtained using the SUPERCELL Method. The tube thicknesses were then calculated so that the flux distributions at steady state full power and the corresponding total reactivity worth of the adjuster rods were in agreement with the reference design valves. The second part deals with the modifications made to the three-dimensionalSORGHUM code to permit calculations of steady-state flux distributions in asubcritical assembly in the presence of a constant non-fission meutron source.

abstract: Thesis

abstract: Master of Engineering (ME)


title: Power Transient in a CANDU Reactor

subject:
effectiveness
Shutoff Rod System
CANDU Reactor
full core simulation

abstract: This file is officially titled as a project. This is Part B in connection with another project by the same author, titled "Part A: Adjuster Rod Design in a CANDU Reactor and Flux Distributions Due to an Arbitrary Source of Neutrons."http://hdl.handle.net/11375/15387

abstract:
In this report, the effectiveness of a proposed Shutoff Rod System
a CANDU Reactor was investigated. A full core simulation was done,
to study the neutronic power transient following a change in coolant
conditions.

abstract: Thesis

abstract: Master of Engineering (ME)


title: REDUCTION OF PRESSURE PULSATIONS ON AUTOMOTIVE TRANSMISSION OIL VANE PUMP

contributor:
Ziada, Samir
Lightstone, Marilyn
Mechanical Engineering

abstract:
The balanced oil pump is an important component of the automatic transmission in modern
automotive vehicles. During the pump operation, pressure pulsations are generated, which negatively
affect the working characteristics of a pump, including pump noise and durability. Thus, pressure
pulsations must be minimized in order to ensure smooth operation of the pump, low noise and
increased durability.
The current work uses Computational Fluid Dynamics (CFD) to explore the effects of port design on
pump pressure pulsations for binary transmission vane pump. Several different approaches are
considered, such as port length at intake and discharge, implementation of metering grooves at
discharge and intake ports, along with different shapes of metering grooves.
More than 20 CFD cases are analyzed to study the effect of different port design on pressure pulsations
of the pump. Validation against experimental data is performed to provide confidence in the CFD
modeling results. It is found that ports can be designed more precisely using CFD than described using
the simple models that are typically used for pump analysis. Implementing metering grooves helps
decreasing pressure pulsations. There is no significant difference in the pressure pulsation generated
with different shapes of metering grooves in the pump non‐cavitation regime. Future work could
consider the effects of the metering grooves geometry on feasibility and durability within the cavitation
regime.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: Sustainable Wastewater Treatment: Nutrient Separation, Energy Recovery and Water Reuse

contributor:
Kim, Younggy
Civil Engineering

subject:
Sustainable wastewater treatment
Nutrient recovery
Energy recovery
Bioelectrochemical systems

abstract: There is a growing awareness of the valuable nutrients (nitrogen and phosphorus) being lost in conventional wastewater treatment systems. Although the removal of these nutrients has been well addressed, efforts for nutrient recovery have seen little development. As the emphasis on sustainability in the wastewater treatment industry increases, conventional wastewater treatment processes are being re-evaluated and new treatment systems developed. A possible nutrient recovery mechanism is the precipitation of magnesium ammonium phosphate hexahydrate (MgNH4PO4·6H2O), commonly known as struvite.  Human urine has been identified as a rich source of nutrients in wastewater; hence the separate collection of urine is considered a viable method of enabling struvite recovery. Since dilution of urine to a certain degree is inevitable, reconcentration of urine beyond the solubility limit of struvite is critical. Currently available methods for reconcentration (e.g., evaporation, freeze-thaw, reverse osmosis and electrodialysis) are relatively expensive with high energy demand. Thus, the research here aims to demonstrate nutrient reconcentration from diluted urine and simultaneous organic removal by using the principles of microbial desalination cells (MDCs), where energy released from organic oxidation is partially used for the separation of nutrient ions. With reduced energy demand, a sustainable method for the utilization of source-separated urine is examined. The performance of bioelectrochemical systems relies on the activity of exoelectrogenic bacteria to transfer electrons to the anode. An examination of exoelectrogen sensitivity at various wastewater treatment conditions (i.e. ammonia and oxygen) is an important component of this research. Methanogenesis is considered the greatest challenge in achieving practical applications in anaerobic bioelectrochemical systems. An electrolytic oxygen production method is suggested for effective control of methanogenesis in a feasible and cost-effective manner.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: Arcadia, Void and Equilibrium: Turgenev's Fathers and Sons and the Writing of Contemporary Ukrainian-Canadians

title: Arcadia, Void and Equilibrium

contributor:
York, Lorraine
English

subject:
Ivan Turgenev
allusions
social
economic
hardship
ideal
reality
resolution

abstract:
Russian realist writer Ivan Turgenev wrote Fathers and Sons in 1861, the middle of the politically, socially and ideologically eventful nineteenth century. While the turbulent historical moment is certainly reflected in the imagined landscape of the novel, Turgenev's text is first and foremost a literary work with implications that extend beyond the moment of its conception. Through allusions to the classical pastoral and juxtaposition of social and economic hardship, Turgenev creates a disconcerting ironic pastoral, or Russian Arcadia, that is marked by tension between a discordant ideal and reality. Resolution can be achieved in two ways that mirror nature's duality: one may become brutal, nihilistic and destructive, or one may strive for harmony and endure with the earth. By contemplation of one's own nature and the limits imposed by culture and
nature itself, Turgenev demonstrates that the individual can come to this harmony, or an adaptive equilibrium that is characterized by balance, stability, and enjoyment of sensory experience.

Turgenev's ironic pastoral, his concern with human brutality and the
madness attendant upon it, the recognition of boundaries, and the sensory as an enduring mode of experience and communication are revisited and reworked by Ukrainian-Canadians in the twentieth century. The 1987 anthology, Yarmarok: Ukrainian writing in Canada since the Second World War, represents one of the most comprehensive collections of Ukrainian-Canadian writing in English and brings together both accomplished and previously unpublished writers that include: Mykola Ponedilok, Ruth Andrishak, Wasyl Sofroniw Levytsky, Stefania
Hurko, Oleh Zujewskyj, Dennis Gruending, Maara Haas, and Bob Wakulich.
These writers draw upon personal and family history and memory, which are haunted by the revolution Turgenev anticipated in Fathers and Sons, to relate their Arcadias, and the equilibriums they envision for individuals striving for balance within the limits imposed by the Canadianizing environment.

abstract: Thesis

abstract: Master of Arts (MA)


title: HYDROGELS AND AEROGELS BASED ON CHEMICALLY CROSS-LINKED CELLULOSE NANOCRYSTALS

contributor:
Cranston, Emily
Chemical Engineering

abstract:
Cellulose nanocrystals (CNCs) make up a promising new class of renewable nanomaterials with unique properties including nano-dimensions, high strength, light weight, liquid crystalline behaviour, biodegradability and general biocompatibility. The objective of this work was to study the use of chemically cross-linkable cellulose nanocrystals in gels, specifically injectable hydrogels and aerogels.

First, aldehyde-functionalized CNCs (CHO–CNCs) were used to reinforce injectable hydrogels based on carboxymethyl cellulose and dextran. The mechanical properties, internal morphology, and swelling of injectable hydrogels with unmodified and modified CNCs at various loadings were examined. The maximum storage modulus was observed in hydrogels with 0.250 wt. % of unmodified CNCs and 0.375 wt. % of CHO–CNCs. CHO–CNCs acted as both a filler and a chemical cross-linker, making the CHO–CNC-reinforced hydrogels more elastic, more dimensionally stable, and capable of facilitating higher nanoparticle loadings, compared to hydrogels with unmodified CNCs. When immersed in purified water or 10 mM PBS buffer, all CNC-reinforced hydrogels maintained their original shape for more than 60 days. No significant cytotoxicity to NIH 3T3 fibroblast cells was observed for the hydrogels or their individual components. These properties make CNC-reinforced injectable hydrogels of potential interest for various biomedical applications such as drug delivery vehicles or tissue engineering matrices.

Next, chemically cross-linked “all-CNC” aerogels were prepared based on similar hydrazone cross-linking with hydrazide-functionalized CNCs (NHNH2-CNCs) and CHO-CNCs. These ultra lightweight (5.6 mg/cm3) and highly porous (99.6%) aerogels displayed bimodal pore distribution (mesopores <50 nm and macropores >1 µm). Chemically cross-linked CNC aerogels showed enhanced mechanical properties and shape recovery ability, particularly in water, compared to previous reports of physically cross-linked CNC aerogels. Specifically, the aerogel shape recovers at least 85% after 80% compressive strain, even after 20 compress and release cycles. These CNC aerogels can absorb significant amounts of both water (160 ± 10 g per g) and dodecane (72 ± 5 g per g) with cyclic absorption capacity. It is demonstrated that CNC aerogels may have application as superabsorbents and for oil/water separations.

abstract: Thesis

abstract: Master of Applied Science (MASc)