title: Belonging In Transition: Former Youth-In-Care’s Sense of Belonging and the Transition to Adulthood

contributor:
Gladstone, Dr. James
Social Work

subject:
youth
foster care
child welfare
adulthood
belonging
transition
children

abstract: Using grounded theory methodology anchored within a life course perspective, this study explored former youth-in-care's sense of belonging and its impact on the transition to adulthood. The findings emphasized the importance of a sense of belonging to creating positive outcomes for young adults during their transition to adulthood.

abstract:
Youth growing up in foster care tend to have poorer outcomes after reaching adulthood than youth in the general population, such as lower educational attainment, lower rates of employment, and more mental/emotional health difficulties than their peers. Although several factors have been suggested to explain this difference in outcomes, most studies have focused on youth’s negative experiences in-care as being the determinant factor. My study adopted an alternative approach and focused on youth who have had positive experiences during care, in hopes of learning from their experience.

Using grounded theory methodology anchored within a life course perspective, this study explored how some youth developed a sense of belonging and what impact this had on their transition to adulthood. Each of the four young adults who participated in this studied shared their experiences of growing up in foster care and the impact this had on their transition to adulthood.

The findings emphasized the importance of a sense of belonging to creating positive outcomes for young adults during their transition to adulthood. Five categories emerged from the data: “lack of control”, “realizing a stable, loving, and secure home”, “navigating multiple attachments”, “gaining a sense of belonging”, and “successful transition to adulthood”. These findings suggest that gaining a sense of belonging may be foundational to a successful transition to adulthood, especially when success is defined in terms of interdependence rather than independence.

abstract: Thesis

abstract: Master of Social Work (MSW)


title: Transcranial Magnetic Stimulation as a Diagnostic Tool for Assessing Motor Impairment of Spinal Cord Injured Individuals

contributor:
Lyons, James
Kinesiology

subject: transcranial magnetic stimulation, diagnostic tool, motor impairment, spinal cord injured individuals, rehabilitation, muscles

abstract:
 Clinical diagnosis, classification of injury and the reliable and detailed description of a patient's neurological status are key factors in determining intervention, rehabilitation programs and predicting recovery. The American Spinal Injury Association (ASIA) impairment scale (AIS) is a standardized method for spinal cord injury (SCI) classification and neurologic status examination. Studies have revealed the AIS classification to be a general assessment tool that fails to explain the varying degrees and patterns of neurological damage, especially in individuals with incomplete injuries. In addition, intragroup variability can be attributed to inaccuracies in examinations and improper assessment tools that have limited research findings. Transcranial Magnetic Stimulation (TMS) has been used as a non-invasive method of evaluating the integrity of the motor nervous system. The primary purpose of this study was to evaluate TMS as an assessment tool to describe motor impairment of SCI individuals. A second purpose of this study was to assess AIS accuracy and sensitivity to muscle activation by using surface electromyographic (sEMG) techniques during clinical examinations. Six incomplete SCI participants were clinically assessed to obtain their individual motor scores from key muscles following AIS assessment criteria. TMS was then used to stimulate the motor cortex to elicit motor evoked potentials (MEPs) in 4 key muscles. MEPs correlated with
motor scores, where significantly higher and lower MEPs corresponded to the highest and lowest motor scores, respectively. Of the 48 muscles analyzed, 18 received a motor score of zero; however MEPs were obtained in 7 of these 18 muscles. In general, MEPs paralleled motor function as assessed by the AIS. Results suggest that TMS may provide information on the relationship between corticospinal integrity and the quality of motor function. In addition, TMS demonstrated adequate validity and sensitivity to SCI individual differences. MEPs provided additional information regarding the existence of spared neuronal pathways not identified by standard clinical evaluations. The therapeutic potential of these motor pathways has yet to be explored. EMG activity was significantly correlated to motor scores and MEPs however; EMG analysis revealed some inaccuracies in muscle examinations and supported MEP data. Results suggest that the implementation of electrophysiological assessment tools may be more sensitive to detect motor damage, adaptive movement patterns and overall muscle activation that may be misinterpreted during clinical examinations.

abstract: Thesis

abstract: Master of Science (MSc)


title: The Impact of Sprint Interval Training on Arterial Compliance and Brachial Endothelial Function in Young Healthy Males

contributor:
MacDonald, Maureen J.
Human Biodynamics

subject: sprint interval training, arterial compliance, brachial endothelial function, young, healthy, males, blood flow

abstract:
 Increased arterial stiffness and vascular endothelial dysfunction have been identified as
independent risk factors for the development and progression of cardiovascular disease.
Traditional endurance training has been associated with elevated levels of central arterial
compliance and an attenuation of cardiovascular events. As well, the positive benefits of
aerobic-based training have been acknowledged as effective modulators of vascular
endothelial function. To date, the impact of sprint interval training on cardiovascular health has not been evaluated. Furthermore, the mechanisms responsible for previously observed enhancements in endurance (750 kJ) performance following two weeks of sprint interval training remain unclear, but may be related to changes in vascular structure and function.

 Nine young healthy males [age: 22 ± 0.5 (mean± SEM)] participated in a two
week sprint interval training program consisting of 4-6 30 second maximum effort exercise bouts performed every other day on a cycle ergometer. In addition, each participant was required to complete a 750 kJ time trial on a cycle ergometer as a measure of aerobic exercise performance before (PRE) and after (POST) training. Measurements of supine, resting carotid pulse pressure, carotid cross-sectional compliance, and brachial vascular endothelial function (using flow mediated dilation) were also acquired PRE and POST training.

 Resting pulse pressure did not show any significant changes with exercise training
(PRE= 48.6±1.6, POST= 52.4±2.5 mmHg, p>0.05). Mean brachial artery diameter was
not changed with sprint interval training (PRE= 4.29±0.17, POST= 4.38±0.18 mm, p>0.05); however, mean carotid artery diameter increased significantly PRE to POST (PRE= 6.40±0.15, POST= 6.49±0.14 mm, p=0.008). Carotid cross-sectional compliance did not change PRE to POST training (PRE= 0.164±0.010, POST= 0.162±0.007 mm^2/mmHg, p>0.05). Brachial vascular endothelial function measured using flow-mediated dilation did not show a significant change with sprint interval training, however a trend towards improvement was noted (PRE= 4.6±1.8, POST= 6.4±1.0 %, p=0.296). When normalized for shear rate (which was also unaltered with sprint interval training) there were no changes in endothelial function (PRE =
0.158±0.068, POST= 0.198 ± 0.034 %/S^-1, p>0.05). Average brachial post-occlusion blood flow was significantly enhanced following training possibly revealing enhanced resistance vessel function (PRE= 296.0±37.4, POST= 324.8±38.8 ml/min, p=0.04), despite no change in peak brachial blood flow (PRE= 332.0±42.3, POST= 362.6±45.7 ml/min, p>0.05). 750 kJ time trial performance was significantly enhanced with training (PRE = 62.8±4.9; POST= 55.84±3.55 min; p=0.006).

 In conclusion, sprint interval training did not change resting carotid compliance or brachial endothelial function, despite significant improvements in aerobic performance (750 kJ). However, carotid resting diameters and brachial post occlusion blood flow were significantly increased PRE to POST and a trend towards improvement was seen for brachial flow mediated dilation. The exact mechanisms responsible for such changes
remain unknown and require further investigation.

abstract: Thesis

abstract: Master of Science (MSc)


title: Sr Isotopic Composition of Saline Waters and Host Rock in the Eye-Dashwa Lakes Pluton, Atikokan, Ontario

contributor:
McNutt, R.H.
Geology

subject: Sr Isotopic composition, saline waters, host rock, eye-dashwa lakes pluton, Atikokan, Ontario, groundwater, mineral separates, granites

abstract:
 Groundwater samples from seven boreholes at the Atikokan research area, northwestern Ontario, have been analysed to determine their Sr content and isotopic composition. Whole rock and mineral separates have also been analysed. The groundwaters can be broadly divided into two groups. The 'shallow' waters have low Sr content and high and variable isotopic ratios (.705 - .728) while the 'deep' Sr-rich saline groundwaters have low and constant 87Sr/86Sr ratios (.706 - .707). The saline waters are in isotopic equilibrium with plagioclase and the role of other major rock forming minerals in controlling the isotopic and
chemical composition of these waters is negligible. Gypsum is in isotopic equilibrium with the saline waters and appears to be 'young'.

 The degree of water-plagioclase interaction appears to have been extensive implying low water/rock ratios (ie., 'closed' system. The chemistry of the Atikokan groundwaters is similar to several Shield mine waters. If seawater was a precursor of these waters, there is no evidence for it today. Some degree of mixing with surface waters is indicated in all samples.

 The granites of the Eye-Dashwa lakes pluton are very Sr-rich. This is reflected in the low isotopic ratios of plagioclase and other minerals and in turn in the low ratios for the saline groundwaters, which are some of the lowest values yet reported.

abstract: Thesis

abstract: Master of Science (MSc)


title: Pattern Extraction by Modeling Image Spatial Relationship

contributor:
Kirubarajan, Thia
Electrical and Computer Engineering

abstract:
In this thesis, a universal framework that is able to extract image spatial relationship among multiple appearance components is proposed, which can be employed to extract additional pattern in wide computer vision tasks. In order to demonstrate its usefulness, three novel algorithms solving different computer vision problems are presented as three main contributions of this thesis, which exercise this framework to improve their performances.

Starting with the object tracking task, the framework is utilized to extract object's inner structure. The algorithm makes use of this inner structure to support a discriminative learning process for mitigating the classic error accumulation effect raising in numerous trackers. In this way, the tracking task is formulated as a prior regularized semi-supervised learning problem. To solve this particular problem, a multi-objective optimization approach is developed. The experiment conducted by the author demonstrates that this tracking algorithm advances state-of-the-art performance of object tracking.

Next, the background subtraction task is studied. In this algorithm, the background is represented by a probabilistic topic model to deal with the dynamic background challenge. This topic model takes advantage of the framework to control topic proportions, which is shown a good descriptor for recurring pixel movement in dynamic background. In order to make the topic model suitable for this on-line task, an incremental learning approach is designed. In the experiment, this background subtraction algorithm outperforms the alternatives in challenging benchmarks.

Finally, the proposed framework is expanded by applying it on a single image processing task, airborne ship detection. The algorithm handles this detection problem by modeling the ocean background and treating the ship pixels as outliers. For simultaneously encoding the dynamic nature and the local similarity of ocean background texture, the framework is used to explore the majority of pixel intensity across the image plane. An extensive experiment shows robustness and accuracy of the ship detection algorithm on a large number of tested images.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: The role of microvesicles in the hyper-coagulation associated with prostate cancer

contributor:
Al-Nedawi, Khalid
Medical Sciences

subject:
prostate cancer
microvesicles
coagulation

abstract: Patients with prostate cancer (PC) are at high risk of developing migratory thrombosis compared to healthy individuals. This is due to the haemostatic abnormality as a result of the presence of cancer, and is referred to as Trousseau’s syndrome. Trousseau's syndrome leads to increased mortality among cancer patients, and is considered the second cause of death after cancer itself. We investigated the role of microvesicles (MVs), which are circular membrane compartments shed from cancer as well as from healthy cells, in the development of Trousseau’s syndrome. We compared the pro-coagulant activities between MVs derived from PC cell lines with different oncogenic and metastatic characteristics, using chromogenic assays to determine their thrombin generation. Microvesicles from the more aggressive DU145vIII and more metastatic PC3-MLN4 show increased thrombin generation compared to MVs derived from DU145 and PC3. We also compared thrombin generation in MVs extracted from plasma of PC patients of various cancer stages. MVs from PC patients with a metastasized tumour had increased thrombin generation compared to patients with localized tumours. Finally, we transfected the CHO cell line with the human protease-activated receptor 1 (hPAR1), the principal receptor of thrombin. PC MVs led to the activation of PAR1 in CHO (hPAR1), indicating thrombin generation. Our in vitro studies suggest a potential role of PC MVs in the migratory thrombosis observed in Trousseau’s syndrome, due to their independent ability to generate active thrombin. We also demonstrated that thrombin generation of PC-derived MVs correlated with the oncogenic and metastatic characteristics of prostate cancer.

abstract: Thesis

abstract: Master of Science (MSc)


title: Repeats in Strings and Application in Bioinformatics

contributor:
Smyth, William F
Golding, Brian
Computational Engineering and Science

subject: Repeats String Bioinformatics Algorithm

abstract:
A string is a sequence of symbols, usually called letters, drawn from some alphabet.
It is one of the most fundamental and important structures in computing, bioinformatics and mathematics. Computer files, contents of a computer memory, network
and satellite signals are all instances of strings. The genome of every living thing
can be represented by a string drawn from the alphabet {a, c, g, t}. The algorithms
processing strings have a wide range of applications such as information retrieval,
search engines, data compression, cryptography and bioinformatics. In a DNA sequence the indeterminate symbol {a, c} is used when it is unclear whether a given nucleotide is a or c, We could then say that {a, c} matches
another symbol {c, g} which in turn matches {g, t}, but {a, c} certainly does not
match {g, t}. The processing of indeterminate strings is much more difficult because
of this nontransitivity of matching. Thus a combinatorial understanding of indeterminate strings becomes essential to the development of efficient methods for their
processing. With indeterminate strings, as with ordinary ones, the main task is the
recognition/computation of patterns called regularities . We are particularly interested in regularities called repeats, whether tandem such as acgacg or nontandem
(acgtacg). In this thesis we focus on newly-discovered regularities in strings, especially the enhanced cover array and the Lyndon array, with attention paid to extending the
computations to indeterminate strings. Much of this work is necessarily abstract in
nature, because the intention is to produce results that are applicable over a wide
range of application areas. We will focus on finding algorithms to construct different
data structures to represent strings such as cover arrays and Lyndon arrays. The
idea of cover comes from strings which are not truly periodic but "almost" periodic
in nature. For example abaababa is covered by aba but is not periodic. Similarly the
Lyndon array describes the string in another unique way and is used in many fields of
string algorithms. These data structures will help us in the field of string processing.
As one application of these data structures we will work on "Reverse Engineering";
that is, given data structures derived from of a string, how can we get the string back. Since DNA, RNA and peptide sequences are effectively "strings" with unique
properties, we will adapt our algorithms for regular or indeterminate strings to these
sequences. Sequence analysis can be used to assign function to genes and proteins
by observing the similarities between the compared sequences. Identifying unusual
repetitive patterns will aid in the identification of intrinsic features of the sequence
such as active sites, gene-structures and regulatory elements. As an application of
periodic strings we investigate microsatellites which are short repetitive DNA patterns where repeated substrings are of length 2 to 5. Microsatellites are used in a
wide range of studies due to their small size and repetitive nature, and they have
played an important role in the identification of numerous important genetic loci. A
deeper understanding of the evolutionary and mutational properties of microsatellites
is needed, not only to understand how the genome is organized, but also to correctly
interpret and use microsatellite data in population genetics studies.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Effect of Whey and Casein Proteins on Muscle Protein Synthesis after Resistance Exercise

subject: whey and casein proteins, muscle synthesis protein, resistance exercise, digestibility, amino acids, unilateral

abstract:
 Protein digestibility, a function of the source of amino acids consumed, can differentially
affect postprandial protein anabolism at rest. We investigated the effect of ingesting whey and casein proteins, in isolation and in combination, after an acute bout of unilateral resistance exercise on muscle protein synthesis in eight healthy resistance trained men (24.4 ± 4.8 yr; 177.4 ± 4.2 cm; 85.5 ± 14.8 kg; means± SD). On three occasions, participants performed a unilateral bout of resistance exercise following which they consumed a drink containing whey, whey and casein (1:1), or casein protein. Each drink provided 10 g of essential amino acids. Mixed muscle protein fractional synthetic rate (FSR) was determined by pulse-tracer injections of L-[ring-2H5]phenylalanine and L-[15N]phenylalanine 120-180 min after protein ingestion. The pattern of amino acid appearance in the blood after consuming the protein drinks was not different. Consequently, while consumption of the protein drinks stimulated a larger increase in FSR in the exercised leg compared to the rested leg (p < 0.05), there were no differences
between the drinks. Thus, while the source of amino acids may affect protein turnover at rest, this effect is not apparent after resistance exercise. Therefore, we conclude that the ingestion of whey and casein proteins, in isolation or combination, stimulates mixed muscle protein synthesis to similar degrees after an acute bout of resistance exercise.

abstract: Thesis

abstract: Master of Science (MSc)


title: The Effects of Previous Athletic Experience on Error Detection and Identification Abilities in Novice and Experienced Coaches

contributor:
Lyons, J.L.
Kinesiology

subject: previous athletic experience, error detection, identification abilities, novice, experienced coaches, skills

abstract:
 Qualitative research exploring the development of coaching skills and knowledge suggests that this development begins with early athletic involvement. Unfortunately, the quantitative research exploring the association between athletic involvement and coaching abilities has not been able to identify a clear and causal relationship. This thesis investigates the relationship between previous athletic experience and current perceptual-cognitive coaching skills in novice and experienced gymnastics coaches using a quantitative experimental paradigm. Novice and experienced provincial and national level gymnastics coaches with and without experience competing at the provincial or national level participated
in this study. In Experiment 1, twenty-three coaches completed a Knowledgebase Task and an Error Identification task. The data demonstrated that experienced coaches performed better on the knowledgebase task (F(1,19)=7.113, p. =0.016) and the Error Identification task than the novice coaches (F(1,18)=14.916, p. =0.001). While there were no performance differences on either task for experienced coaches with either significant or minimal athletic histories, novice coaches without previous athletic experience outperformed the novice coaches with previous athletic experience when asked to identify the initial error in a flawed gymnastics sequence (F(1,18)=5.338,p. =0.03). This counterintuitive result was further explored in Experiment 2. It was hypothesized that the nature of the knowledge on which the novice coaches rely differed based on their athletic histories. Specifically, novice coaches without athletic experience would rely to a greater degree on explicit knowledge whereas novice coaches with previous athletic experience would rely upon implicit knowledge acquired while an athlete. The results of Experiment 2 did not support this hypothesis. While this thesis was able to develop further insight into the relationship between previous athletic experience and current perceptual-cognitive coaching abilities, no clear and causal conclusions were drawn. Additional research is required to fully understand this complex and multi-dimensional relationship.

abstract: Thesis

abstract: Master of Science (MSc)


title: INVESTIGATING THE EFFECT OF AEROBIC EXERCISE ON COGNITIVE FUNCTION IN OLDER ADULTS

contributor:
Heisz, Jennifer
Kinesiology

abstract:
Aging is associated with cognitive decline and an increased risk for
neurodegenerative disease. Physical exercise may be an effective intervention to enhance
cognitive function in older adults; however, the optimal dose for maximal cognitive
benefit is unknown. Additionally, the mechanism through which exercise may promote
cognition in older adults is poorly understood. The present study investigated the effect of aerobic exercise intensity on cognitive function in three domains: memory, processing
speed, and executive functions. Brain-derived neurotrophic factor (BDNF), a protein that
supports the growth and survival of neurons, was examined as a potential mechanism
underlying the effect of exercise on cognition. Sixty-four sedentary older adults (39
females; mean age=72 years; age range=60-88 years) were randomly assigned to one of three groups: 1) high-intensity interval training group (HIIT; n=21), 2) moderate
continuous training group (MCT; n=20), or 3) active control group (n=23). Cognitive
function was assessed pre- and post-intervention using a Mnemonic Similarity
Task (memory), a Go-nogo task (processing speed and executive function), and a Flanker
task (executive function). Serum BDNF concentrations were assessed using enzyme-linked immunosorbent assays (ELISAs). It was hypothesized that HIIT would result in
the greatest cognitive benefit, followed by MCT. The control group was not expected to
improve. It was predicted that improvements in cognition would be accompanied by
increases in serum BDNF. HIIT resulted in better performance on the Mnemonic
Similarity Task [F(2, 55)=6.04, p=0.004] compared to both MCT and control. The MCT group had faster processing speed on the Go-nogo task [F(2, 59)=4.16, p=0.02] compared to control. HIIT and MCT both had a trend toward better performance on the Go-nogo task [F(2, 59)=2.54, p=0.088] compared to control. Only HIIT resulted in a trend toward better performance on the Flanker task [F(2, 56)=2.41, p=0.099] compared to both MCT and control. No significant differences were found in BDNF concentration between groups. This is one of the first trials to directly compare the effect of different intensities of aerobic exercise on cognitive function. Consistent with prior literature, the results suggest that aerobic exercise can enhance cognitive function in older adults, and critically, HIIT was the most effective. However, BDNF may not mediate the changes in cognition in older adults. This research may help inform exercise prescription for optimal cognitive health in the growing population of older adults.

abstract: Thesis

abstract: Master of Science (MSc)


title: Synthesis and Evaluation of Nuclear and Optical Tetrazine-6-Hydrazinopyridine-3-Carboxylic Acid Probes for Molecular Imaging using Pretargeting and Bioorthogonal Chemistry

contributor:
Valliant, John F.
Chemical Biology

abstract:
The aim of this thesis was to develop a new platform for the creation of targeted nuclear and optical molecular imaging probes. Current probes suffer from low target-to- background ratios, which can hinder diagnosis and monitoring of disease treatments due to poor image acquisition. To overcome this limitation, the approach taken involved coupling 6-hydrazinopyridine-3-carboxylic acid (HYNIC) to a tetrazine, where the product could be used to create targeted 99mTc and near-infrared dye probes. Targeting could then be accomplished using bioorthogonal chemistry with trans-cyclooctene (TCO) functionalized biomolecules, through an inverse electron demand Diels-Alder cycloaddition.
The assessment for the clinical translation of 99mTc-HYNIC based nuclear probes was evaluated to determine the feasibility of using a ‘kit-like’ formulation system. A limitation associated with the development of HYNIC-based radiopharmaceuticals is the need for HPLC purification. The investigation into the need for HPLC purification was performed, where it was determined that there was no significant difference in target uptake between the HPLC-purified and non-purified 99mTc-HYNIC probe 6 when used with bone-seeking TCO-derived bisphosphonate (4.73 ± 0.47 versus 4.15 ± 0.27%ID/g in shoulder, 6.32 ± 0.21 versus 5.94 ± 0.59%ID/g in knee, respectively). This suggests that a kit-like system would be practical; thus streamlining the chemistry required for radiopharmaceutical development. Efforts to reduce non-target organ uptake observed with using 6 was accomplished through the synthesis of a more polar construct 12. While the compound rapidly cleared from non-target organs, it also displayed lower target uptake compared to 6 (1.62 ± 0.22 versus 4.15 ± 0.27%ID/g in shoulder, 2.39 ± 0.22 versus 5.94 ± 0.59%ID/g in knee, respectively), demonstrating the need for further pharmacokinetic optimization.
The synthesis and evaluation of optical imaging probes was also completed, where the HYNIC-tetrazine core was linked to a commercially-available near-infrared dye through a hydrazone linkage. The bacterial binding capabilities of fluorescent compounds 22 and 24 (analogous to the 99mTc-labelled 6 and 12) were investigated in vitro using Gram-positive Staphylococcus aureus with TCO-modified vancomycin. The targeted samples exhibited a 3.8-fold (22) and 8.6-fold (24) increase in fluorescent intensity when compared to the blocking control used to account for binding specificity. Fluorescent microscopy images were also obtained, however only bacterial aggregates were observed, indicating the need for optimization of microscopy procedures. As such, a HYNIC-tetrazine platform was successfully developed as a means synthesize various targeting probes for molecular imaging applications using pretargeted, bioorthogonal chemistry.

abstract: Thesis

abstract: Master of Science (MSc)


title: The Regulation of IL-33 and Arginase-1 by Oncostatin M in Mouse Lung Systems

contributor: Medical Sciences (Molecular Virology and Immunology Program)

subject: gp130 cytokines, lung, fibrosis, influenza, alarmin, IL-33, macrophage, arginase-1

abstract:
Excessive tissue fibrosis in various lung diseases contributes to decline in lung function and subsequent morbidity and mortality. Mechanisms involve complex networks of molecules such as cytokines that are not clearly worked out in conditions such as Idiopathic pulmonary fibrosis (IPF). Furthermore, pulmonary virus infection has been linked to exacerbations of IPF. Previous studies have demonstrated that transient pulmonary over-expression of Oncostatin M (OSM) leads to increased extracellular matrix (ECM) accumulation, Th2-skewed cytokines and Arg1+ M2-like macrophage accumulation in mouse models. OSM can also robustly induce interleukin-33 (IL-33), an IL1 family cytokine or alarmin, both in vivo and in vitro mouse lung systems. Since others have shown that soluble IL-33 exacerbates bleomycin-induced lung fibrosis in mouse models and is associated with Th2-type lung diseases, IL-33 may mediate OSM effects on ECM and Arg1+ macrophage-like cell accumulation. The main hypothesis in this thesis is that OSM can induce IL-33 expression and Arg1+ cells, that OSM can potentiate IL-33 release from virally-infected epithelial cells, and that OSM can prime lungs to subsequent influenza infection and exacerbate pathology.
Results demonstrated that OSM induced robust up-regulation of pulmonary IL-33 and Arg1 mRNA and protein expression in vivo, in comparison to another gp130 cytokine, IL-6. However, IL-6 was required for OSM-induced arginase-1 expression in vivo, but not IL-33 expression in vivo. OSM-induced Arg1 expression was also dependent upon IL-33 presence as demonstrated in IL-33-/- animals. This finding implicates a role for both IL-33 and IL-6 in mediating OSM-induced Arg1+ macrophage-like cell accumulation within the lung.
Additionally, results showed that a respiratory Influenza A virus infection in vivo alone induced a time-dependent increase in OSM and IL-33 (Day 4), however reduced IL-33 by 7-days post-infection. Influenza infection in AdOSM-primed mice and led to decreased IL-33 expression and eosinophilic infiltration within the lung 5-days post-influenza infection. Collectively, these results demonstrate that OSM can drive Th2-associated pathology correlated to increased IL-33 and Arg1 expression. Contrary to expectations, influenza A virus infection led to a reduction in OSM-induced Th2-phenotype in vivo. Further exploration into the OSM-IL-33 pathway will provide insight into innate immune mechanisms of lung inflammation, virus infection and control of ECM accumulation.

abstract: Thesis

abstract: Master of Science (MSc)


title: The Effect of Verbal Prosody on Speech Perception in Adults With and Without Down Syndrome

subject: verbal prosody, speech perception, adults, down syndrome, motor control

abstract:
 Emotion perception in speech has been shown to facilitate greater understanding and
learning in adults as well as children. There is an atypical RH specialization for speech perception that exists in individuals with Down Syndrome (DS). Individuals with DS have a typical left hemisphere specialization for motor control and speech production, similar to those individuals from the general population which may cause a functional dissociation between speech perception and motor control for these individuals (Heath et al., 2000). What remains unknown is how this atypical lateralization may influence speech perception when emotional intonation is included with verbal stimuli. Using a free recall dichotic listening paradigm, it was found that individuals with DS process verbal stimuli similarly to mental-age matched peers
(individuals with a developmental delay, and individuals for the general population.) To investigate this further, a directed attention paradigm was employed. Participants listened to a particular ear for either a particular word or emotion. It was found that individuals from the general population were more accurate than individuals from either of the other two groups for perception of the word. Also, an effect for Ear was found with the right ear being significantly more accurately perceived than the left for all three groups. When emotion was attended to specifically, the left ear was more accurately perceived than the right. These results are somewhat consistent with previous findings (e.g., Bulman-Fleming & Bryden, 1994) for participants from the general population however the expected lateralization in DS group was not evident. This lack of atypical RHA in individuals with DS may be related to the task itself.

abstract: Thesis

abstract: Master of Science (MSc)


title: Determinants of Physical Activity in Chronic Kidney Disease Patients: An Examination of the Theory of Planned Behaviour

contributor:
Ginis, K.A. Martin
Kinesiology

subject: determinants, physical activity, chronic kidney disease patients, theory of planned behaviour, predialysis

abstract:
 Physical activity improves physical and psychological functioning in patients with chronic kidney disease (CKD). However, no studies have investigated the determinants of physical activity in the CKD population. The purpose of the study was to evaluate the utility of the Theory of Planned Behaviour (TPB) for understanding physical activity in the CKD population. A secondary purpose of this study was to examine alternate conceptualizations of the subjective norm construct within the TPB framework. We hypothesized that attitude, subjective norm (injunctive and descriptive norms), perceived behavioural control (PBC), and social support would predict intention to engage in physical activity and that both intention and PBC would predict physical activity behaviour.

 Participants (52 male, 28 female, mean age = 68.43 (13.21)) were recruited from nephrologists' clinics and were all predialysis (mean serum creatinine = 310.55 (148.75) μmol/L). Participants completed a questionnaire
assessing attitude, subjective norm, PBC, and social support. One week later, participants were phoned for a follow-up interview to assess their physical activity during the preceding week.

 In a regression model, 61% of the variance in intention to perform physical activity was explained, with PBC (β=.69,p<.001) emerging as the sole significant predictor, while attitude (β=.17, p=.10), subjective norm (β=.02, p=.89), informational support from family (β=-.10,p=.33), and informational support from doctors (β=-.05, p=.54) were non-significant predictors. In a regression model to explain physical activity, 28% of the variance in physical activity was explained, with intention emerging as a significant predictor (β=.53,
p=.02), but not PBC (β=.18, p=.29).

 The hypotheses were only partially supported, as PBC emerged as a significant predictor of physical activity intention, while attitude, subjective norm, and social support did not. Furthermore, intention, but not PBC, predicted
physical activity behaviour. These results demonstrate the utility of the TPB for explaining physical activity in the CKD population. Additional research is required to clarify if targeting PBC may be an effective means for intervention to increase physical activity in the CKD population.

abstract: Thesis

abstract: Master of Science (MSc)


title: CHARACTERIZATION OF THE INLET FLOW CONDITIONS FOR THE MODERATOR TEST FACILITY

contributor: Engineering Physics and Nuclear Engineering

subject: CFD Turbulence Moderator CANDU RANS Manifold

abstract:
Flow in the Moderator of a CANDU reactor can be very complex due to the interplay of convective and buoyant effects. Experiments have been performed to measure temperature and velocity fields for these kind of flows, although concerns still exist. As a result a Moderator test facility has been built in order to validate CFD models for future predictions and safety analysis. To properly validate this experiment an accurate set of inlet flow conditions must be established in order to ensure a fair comparison.

A series of flow conditions indicative of the header assemblies which feed flow into the moderator test facility have been investigated through experimentation, empirical evaluation and numerical simulation. They include flow through curved tubes, turbulent free jets and flow through dividing manifolds. The goal of the present study is to establish the modelling approach to predict the flow distribution inside the manifold and velocity field out of the J-nozzles.

A variety of RANS based turbulence models and computational meshes were employed in the numerical study. The turbulence model that was found to perform best was the realizable k- model. It was also found that the velocity field of the J-nozzles is constant between Reynolds numbers of 6800-9300. These Reynolds numbers are indicative of those expected out of the header assemblies.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: Effects of 8-Weeks of Isometric Handgrip Training on Resting Arterial Pressure

contributor:
McCartney, Neil
Kinesiology

subject: 8-weeks, isometric, handgrip, training, resting arterial pressure, heart rate

abstract:
 Recent evidence has demonstrated that isometric handgrip training may improve resting arterial blood pressure. The current study evaluated the ability of simple, spring handgrips to reduce resting arterial blood pressure in normotensive participants using an 8-week randomized controlled design.

 Forty-nine (age: 66 ± 1) participants, 28 female and 21 males were recruited. All participants completed 5 pre-training sessions, used to familiarize and assess baseline blood pressure, heart rate and maximal hand strength. Maximal hand strength was assessed by three bilateral, maximal contractions with a hand dynamometer. Blood pressure and heart rate were assessed with an automated acquisition system. Participants were stratified to control and intervention groups based on baseline age and blood pressure by matched-pair randomization.

 Participants in the training condition (n = 25) completed 8 weeks of thrice weekly handgrip training at approximately 30% of their baseline maximal hand strength using a spring handgrip. Seated blood pressure and heart rate were assessed prior to each training session following 10 minutes of isolated rest. Training included 4, 2-minute contractions separated by 2 minutes of rest and completed bilaterally. Control participants (n = 24) completed weekly-seated measurements of blood pressure and heart rate following 10 minutes of isolated rest. Following 8 weeks of intervention all participants completed 3 sessions of post-training measurements.

 In trained participants, resting systolic and diastolic pressure decreased significantly from pre- to post- (SBP: 122 ± 3 mmHg to 112 ± 3 mmHg, DBP: 70 ± 1 mmHg to 67 ± 1 mmHg) while heart rate remained unaltered. Pulse pressure was significantly reduced with handgrip training, from 52 ± 3 mmHg to 45 ± 3 mmHg. Control participants demonstrated no changes in blood pressure, heart rate and pulse pressure, over the course of the study.

 In conclusion, spring handgrip training results in significant decreases in systolic, diastolic and pulse pressure. The mechanisms behind these improvements remain unknown and require further investigation.

abstract: Thesis

abstract: Master of Science (MSc)


title: The Acute Cardiovascular Response to Multiple Wingate Exercise in Healthy Males

contributor:
MacDonald, Maureen Jane
Kinesiology

subject: acute, cardiovascular, response, multiple wingate exercises, healthy, males, blood flow, recovery, total peripheral resistance

abstract:
 The Wingate anaerobic test can be used in an exercise training program as a powerful training stimulus for producing metabolic and performance enhancements. Although the acute cardiovascular responses in terms of heart rate (HR), blood pressure (BP), stroke volume (SV), cardiac output (CO), and leg blood flow following a single Wingate have been characterized, the acute cardiovascular recovery pattern in response to multiple Wingate exercise bouts performed in an interval pattern have yet to be described. The purpose of the current investigation was to characterize that acute cardiovascular recovery period following multiple Wingate exercise. We observed the recovery patterns of HR, BP, SV, CO, and leg blood flow for 120 minutes immediately following multiple Wingate exercise. Ten recreationally active males aged 19.8 ± 1.2 years (mean± SD) years performed a single bout of Wingate exercise, and a session of multiple Wingate exercise in random order, on separate days. Cardiovascular measurements were conducted at rest and after two-minutes of recovery and then continued at 15-minute intervals until 120 minutes of recovery. HR was elevated
immediately after exercise compared to rest, and declined towards resting values for the
remainder of recovery, although HR failed to return to resting values after 120 minutes of
recovery. SV was significantly decreased, compared to rest, immediately following exercise from 87.3 ± 5.7 to 60.0 ± 5.6 ml. CO was increased compared to rest at two minutes following multiple Wingate exercise, and continued to increase to a maximum recovery value of 8.1 ± 0.7 L/min at R15. Immediately following exercise systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP) were all elevated to 155 ± 3, 73 ± 2, and 100 ± 3 mmHg respectively. Although SBP and MAP returned to resting values 15-minutes after exercise, DBP continued to decrease, resulting in a period of hypotension observed from R15 and R30. Leg blood flow was elevated compared to rest following exercise. Common femoral artery (CFA) blood flow was higher after a single Wingate, than after multiple Wingate exercise (1264 ± 109 and 1036 ± 86 ml/min respectively). Superficial femoral artery (SFA) blood flow (616 ± 55 ml/min) immediately following multiple Wingate exercise was not different following a single Wingate, however the time to return to resting values was longer after multiple Wingate exercise. We attribute the sustained elevations in (SFA) blood flow to increased cutaneous flow for thermoregulation purposes following multiple Wingate exercise.

 The results of this investigation indicate that the general cardiovascular recovery time is longer after multiple Wingate exercise, than after a single Wingate bout. This type of supramaximal exercise temporarily reduces SV due to elevated SBP and decreases in cardiac preload that are not facilitated by vasodilatation and decreased total peripheral resistance (TPR).

abstract: Thesis

abstract: Master of Science (MSc)


title: The Effects of Performance-Based and Self-Controlled Feedback Schedules on Motor Learning

contributor:
Lee, Timothy D.
Kinesiology

subject: performance-based, self-controlled, feedback, schedules, motor learning

abstract:
This study examined the effects of self-controlled and performance-based feedback schedules on the acquisition and retention of a novel motor task. In Experiment 1 participants performed an interception task on a computer using a mouse-controlled cursor. The goal of the task was to intercept the image of a red circle as it passed through a designated area. Each trial received a score based on the speed and accuracy of the interception movement. Participants were randomly assigned to three feedback groups: Best-trial feedback, Worst-trial
feedback, and Self-controlled feedback. No differences were found between groups in acquisition, however analysis of no-feedback retention and transfer tests indicated that the Worst-trial group showed the most significant improvements in performance. Experiment 2 examined the potential mechanisms contributing to the advantages of a worst-trial feedback schedule. Participants in the second experiment performed the same interception task utilized in Experiment 1 under two novel feedback conditions: Estimation feedback and Immediate feedback. These new groups were compared to the Worst-trial group from Experiment 1.
Analysis of no-feedback retention and transfer tests again indicated that the Worst-trial group showed the most significant improvements in performance. These results suggest that self-controlled schedules may not be ideal when feedback is based on performance; instead, specific error information for the least successful trials appear to be most beneficial, especially when individuals have knowledge of results regarding previous attempts at the task.

abstract: Thesis

abstract: Master of Science (MSc)


title: In Vivo Quantification of Bone Strontium Using X-Ray Fluorescence

contributor:
Chettle, David R.
Medical Physics

subject: In vivo, quantification, bone strontium, x-ray, fluorescence, skeletal health, mineral

abstract:
Strontium (Sr) is an element naturally present in the human skeleton and is acquired through dietary means. Exposure to strontium has been linked to both harmful and beneficial effects on skeletal health. Recently, the administration of strontium has been shown to induce a therapeutic effect of increasing bone strength and bone mineral density in women suffering from post-menopausal osteoporosis. The advent of this new therapy has warranted the continued development of an energy dispersive x-ray fluorescence (EDXRF) system that may be used as a diagnostic tool for non-invasive measuring and monitoring of in vivo bone strontium levels. This device is currently housed at McMaster University and has been previously optimized to measure bone strontium in vivo. One shortcoming with this system is the inability to quantify absolute amounts of bone strontium in vivo due to Sr x-ray
absorption by soft-tissue overlying bone. This work describes an attempt to examine several imaging modalities to determine which modality may provide overlying tissue thickness readings with an acceptable range of accuracy to correct for Sr x-ray absorption. A performance comparison between magnetic resonance imaging, x-ray computed tomography, 8, 25 and 55 MHz ultrasound, in estimating the tissue thickness of seven cadaver fingers, illustrated that 55 MHz ultrasound provided a superior range of accuracy at 3.2%. It further indicated that the currently used 8 MHz ultrasound may be used to accurately estimate tissue thickness, though with a diminished accuracy of 6.6%. EDXRF measurements were performed on cadaver fingers ex vivo. Analysis of results indicated that quantification might be achieved if signals are normalizated to the 35 keV coherent scatter peak and correction of both soft-tissue absorption of Sr x-rays and differences in 125I excitation source activity are carried out. Four EDXRF measurements were performed on a strontium citrate supplemented individual starting six months after Sr medicating had begun. Analysis of strontium levels revealed that bone strontium was already at a plateau by the first measurement and that these levels did not change in the 6 months following.

abstract: Thesis

abstract: Master of Science (MSc)


title: Effects of Isometric Handgrip Training on Resting Arterial Pressure and Heart Rate Variability in Newly Diagnosed Hypertensives

subject: isometric handgrip training, resting arterial pressure, heart rate, variability, newly diagnosed hypertensives, exercise

abstract:
 Hypertension is a modifiable risk factor for cardiovascular disease. The current treatment options are drug therapy and lifestyle modifications. A promising lifestyle modification therapy for the management of hypertension is isometric exercise, as several studies have demonstrated that isometric handgrip (IHG) training reduces resting arterial blood pressure (ABP) (Peters et al., 2006; Taylor et al., 2003; Wiley et al., 1992). The purpose of the present investigation was two-fold: 1) to examine the effectiveness of IHG training in reducing resting ABP in newly diagnosed hypertensive patients, in comparison to matched controls receiving advice from a physician about lifestyle modifications; and 2) to examine markers of autonomic function, specifically, heart rate variability (HRV) to determine if changes in the autonomic nervous system (ANS) existed between the two groups of hypertensive adults.

 Resting blood pressure and heart rate were assessed with an automated acquisition system before, during and after the 6-week intervention period. Also, power spectral analysis of HRV was used to assess changes in modulation of the ANS. Participants in
both groups (n=14) were given lifestyle modification recommendations regarding diet,
exercise and stress reduction, while participants in the training group (n=8) also
completed a bilateral IHG training protocol 3 times/week at 30% maximum voluntary
contraction (MVC).

 Our results demonstrate that contrary to our hypothesis, isometric exercise in combination with lifestyle modification recommendations did not result in a reduction of resting ABP or change indices of HRV. Possible explanations for these results are that unlike previous IHG training, the present study was the first to use home-based training and the small sample size of this investigation would limit our ability to identify
alterations in resting ABP or HRV.

abstract: Thesis

abstract: Master of Science (MSc)


title: Bridging the gap: cognitive approaches to musical preference using large datasets

contributor:
Woolhouse, Matthew H.
Psychology

subject:
Music cognition
music preference
music information retrieval

abstract: Using a large dataset of digital music downloads, this thesis examines the extent to which cognitive-psychology research can generate and predict user behaviours relevant to the distinct fields of computer science and music perception. Three distinct topics are explored. Topic one describes the current difficulties with using large digital music resources for cognitive research and provides a solution by linking metadata through a complex validation process. Topic two uses this enriched information to explore the extent to which extracted acoustic features influence genre preferences considering personality, and mood research; analysis suggests acoustic features which are pronounced in an individual's preferred genre influence choice when selecting less-preferred genres. Topic three examines whether metrics of music listening behaviour can be derived and validated by social psychological research; results support the notion that user behaviours can be derived and validated using an informed psychological background, and may be more useful than acoustic features for a variety of computational music tasks. A primary motivation for this thesis was to approach interdisciplinary music research in two ways: (1) utilize a shared understanding of statistical learning as a theoretical framework underpinning for prediction and interpretation; and (2) by providing resources, and approaches to analysis of "big data" which are experimentally valid, and psychologically useful. The unique strengths of this interdisciplinary approach, and the weaknesses that remain, are then addressed by discussing refined analyses and future directions.

abstract: Thesis

abstract: Master of Science (MSc)

abstract: This thesis examines whether research from cognitive psychology can be used to inform and predict behaviours germane to computational music analysis including genre choice, music feature preference, and consumption patterns from data provided by digital-music platforms. Specific topics of focus include: information integrity and consistency of large datasets, whether signal processing algorithms can be used to assess music preference across multiple genres, and the degree to which consumption behaviours can be derived and validated using more traditional experimental paradigms. Results suggest that psychologically motivated research can provide useful insights and metrics in the computationally focused area of global music consumption behaviour and digital music analysis. Limitations that remain within this interdisciplinary approach are addressed by providing refined analysis techniques for future work.


title: Autonomy Support, Self-Determined Motivation, and Exercise Adherence in Cardiac Rehabilitation

contributor:
Bray, S.R.
Kinesiology

subject: Autonomy, Exercise, Cardiac Rehabilitation, Self-Determined, patients, behavioural

abstract: Despite the known benefits of regular exercise for cardiac patients (Jolliffe et al., 2001) and the delivery of cardiac rehabilitation programs to facilitate exercise participation in this population, exercise adherence remains a challenge for these individuals as evidenced by the reported decline in exercise participation over time (e.g., Moore et al., 2006). Investigating cardiac patients' motivation or willingness to engage in exercise may provide a better understanding of why some patients are better maintainers of exercise and others are not. Using self-determination theory (Deci & Ryan, 1985; 2002), the present study investigated changes in need satisfaction and selfdetermined motivation, as well as the role of perceived autonomy support relative to patient motivation, in the early months of participation in cardiac rehabilitation. It was hypothesized that need satisfaction and autonomous forms of behavioural regulation would increase over time, and that perceived autonomy support (ratings of exercise leaders' tendencies to acknowledge patients' perspectives, provide choices and contingent feedback, etc.) would positively predict changes in behavioural regulation, mediated by changes in psychological need satisfaction. Another aim of the study was to examine how autonomous forms of behavioural regulation related to cardiac patients' exercise intentions and self-managed exercise behaviour, and it was hypothesized that this relationship would be positive for both exercise intentions and behaviour. Fifty-three male participants (Mage= 62.83 ± 10.78) who were enrolled in a hospital-based cardiac rehabilitation program completed assessments of perceived autonomy support, need satisfaction and behavioural regulation at weeks 4, 8, and 12 of program participation. At week 14, participants' self-managed exercise behaviour and their exercise intentions to engage in independent exercise for the next 4 weeks were assessed. In general, participants' scores for all variables of interest were relatively high. Consistent with hypotheses, autonomy and relatedness need satisfaction, along with integrated and intrinsic regulation increased from week 4 to week 12 during cardiac rehabilitation. However, perceived autonomy support was not related to changes in need satisfaction or behavioural regulation, and thus, support for mediation was not obtained. Nonetheless, the high ratings of perceived autonomy support reflect the exercise leaders' natural tendency to use an autonomy supportive teaching style with patients. In addition, a positive relationship was found between autonomous forms of behavioural regulation (i.e., integrated and intrinsic) and exercise intentions, lending support to the SDT framework. The positive findings for need satisfaction, autonomous regulation, exercise intentions, and behaviour reflect a highly self-determined group of cardiac patients who are choosing to engage in self-managed exercise while still participating in the supervised cardiac rehabilitation program. These findings are promising in terms of regular exercise adoption in this population.

abstract: Thesis

abstract: Master of Science (MSc)


title: Measurement of Body Postures and Movements in Adults with Cerebral Palsy

contributor:
Gorter, Jan Willem
Rehabilitation Science

subject:
Adults
Cerebral Palsy
Activity Monitor
Physical Behaviour
Postures and Movements
Measurement

abstract:
Aim: To determine the criterion validity of the Activ8a and VitaMoveb activity monitors (AM) in measuring body postures and movements (P&M) in adults with spastic cerebral palsy (CP) with different gross motor functional abilities in a simulated free-living environment.
Methods: In this observational validation study participants were included between March and June 2016. Participants were divided into two groups: ambulatory and non-ambulatory adults (wheelchair users). For ambulatory adults, three Activ8 monitors (attached to the frontal thigh, lateral thigh, and in the pant pocket) and three synchronized VitaMove monitors (attached to the chest and each leg) were worn while participants were video recorded when performing a standardized activity protocol. For non-ambulatory adults, two synchronized Activ8 monitors (attached to the dominant wrist and wheelchair wheel) and three VitaMove monitors (attached to the chest and each wrist) were worn while participants were video recorded when performing a standardized wheelchair protocol. A native Dutch student provided standardized instructions while the author video recorded participants. Activities were performed in a movement laboratory and simulated free-living environment. Output data of the Activ8 and the VitaMove monitors were compared with video observation as a criterion measure. Absolute and relative time differences were calculated for each detected body P&M and for total measurement time for each participant. The following body P&M categories were detected: sitting, standing, walking, running, cycling, wheelchair driving, active upper body (stable wheelchair), and assisted driving. Agreement between the Activ8 and VitaMove during activity measurement was determined for each activity using Spearman Rho correlation coefficients, which were then compared with Meng’s test. Adapted Bland-Altman plots were completed to determine agreement at an individual level and Wilcoxon Signed-Rank tests were calculated to evaluate differences between detected P&M time across measures. Relative time differences of <10% between measures were indicative of acceptable validity.
Results: Fifteen adults with spastic CP [10 men; mean(SD) age, 35.7(13) years; Gross Motor Function Classification System distribution: level I (n=6), level II (n=5), level III (n=3), level IV (n=1)] were included. For ambulatory adults (n=14), criterion validity of the Activ8 at the lateral thigh location during basic and complex daily life activities was moderate to good (average relative time differences: 0.25% for sitting, 4.69% for standing, 2.46% for walking, 3.19% for cycling, and 1.96% for light-to-moderate upright activity), except for running (34.6% average difference) The criterion validity of the VitaMove was acceptable, with the exception of standing and running (average relative time differences: 1.69% for sitting, 12.3% for standing, 4.84% for walking, 9.70% for cycling, 23.8% for running, and 0.91% for light-to-moderate upright activity). Spearman Rho correlation coefficients were significantly greater between video/lateral thigh Activ8 than video/frontal thigh Activ8 and video/pant pocket Activ8 for P&M categories sitting, basic standing, basic walking, and light-to-moderate upright activity (p<0.01 for all).  Moreover, Spearman Rho correlation coefficients were significantly greater between video/Activ8 than video/VitaMove for basic walking and light-to-moderate upright activity P&M categories (p<0.01). In non-ambulatory, wheelchair users (n=3), the Wheelchair Activ8 demonstrated greater validity than the VitaMove monitor, when compared to video observation, for the detection of sedentary upper body and active upper body behaviours.
Conclusion: The Activ8, positioned on the lateral thigh, demonstrates adequate validity as a tool for monitoring of body P&M during free-living activities in ambulatory adults with spastic CP. The Activ8 demonstrated superior validity as a direct measure of body P&M compared to the VitaMove AM. The sample size of non-ambulatory adults was small (n=3) and allowed for descriptive and exploratory analysis only; therefore, validity of the Wheelchair Activ8 for has to be further examined in a larger number of participants.
Clinical relevance: The Activ8 and Wheelchair Activ8 shows promise as a clinical measurement tool of physical behaviour for adults with CP across GMFCS levels I-IV. The Activ8 could be used in the future development of health promotion initiatives, due to the features of goal setting and user feedback, while providing researchers greater insight in activity data than consumer-grade AMs.

Suppliers:
a.	Activ8, trademark of Remedy Distribution Ltd. (original equipment manufacturer is 2M Engineering Ltd.), John F Kennedylaan 3, 5555XC, Valkenswaard, The Netherlands
b.	VitaMove, 2M Engineering Ltd., John F Kennedylaan 3, 5555XC, Valkenswaard, The Netherlands

abstract: Thesis

abstract: Master of Science (MSc)


title: Low Volume Resistance Exercise Prevents Loss of Muscle Mass and Function During 14 Days of Knee Immobilization

contributor:
Phillips, Stuart M.
Kinesiology

subject: low volume resistance, exercise, loss of muscle mass, knee, immobilization, gastrocnemius, flexion

abstract:
 We aimed to determine the effectiveness of a low volume of high-intensity resistance
exercise, alone (EX) or in combination with a whey protein supplement (WHY +EX), on
prevention of muscle mass and strength loss following 14 days of knee immobilization in
humans. Seventeen recreationally active (i.e., exercise ≤ 2-3 d·wk^-1) participants (23.9±5.0 yr; BMI = 25.4±3.6 kg·m^-2) were divided into three groups: exercise (EX;
n=6), whey protein supplementation with exercise (WHY+EX; n=6), and control (CON;
n=5). All subjects wore a knee-immobilization brace such that one leg was completely non-weight bearing for 14d. The resistance exercise (RE) were performed unilaterally and consisted of one set of ten repetitions of leg press (with plantar flexion at full extension), knee extension, and seated calf raises every other day during the 14d immobilization period, at 80% of one repetition maximum. Subjects in the WHY+EX group consumed two 30g boluses of whey protein daily while EX and CON consumed isocaloric carbohydrate beverages. Immobilization induced a significant reduction (p<0.05) in thigh cross-sectional area (CSA), isometric knee extensor strength, and isometric plantar flexion strength in CON but not in EX and WHY+EX. There were significant losses in lower leg CSA for all three groups, with a tendency for losses to be mitigated in both the EX and WHY+EX groups versus CON (p=0.065). The two constituent muscles of the triceps surae muscle group showed a differential response to the RE training with the gastrocnemius showing reductions in CSA almost uniformly across the three groups whereas soleus CSA was significantly reduced in the CON (p<0.05) but not in the EX and WHY+EX groups. We conclude that a relatively low volume of high-intensity resistance exercise is an effective countermeasure against atrophy of the thigh and the soleus muscle, as well as against knee extension and plantar flexion strength loss during 14d of leg immobilization. As a countermeasure to immobilization, there is no additional benefit of consumption of a daily whey protein supplement in combination with resistance exercise in maintaining muscle mass or strength.

abstract: Thesis

abstract: Master of Science (MSc)


title: Activation of Satellite Cells Following Eccentrically-Biased Exercise in Humans

contributor:
Parise, Gianni
Kinesiology

subject: activation, satellite cells, eccentrically-biased, exercise, humans, blood samples, HGF protein, muscle

abstract:
 We aimed to examine the satellite cell response and the potential of HGF signaling in
mediating satellite cell activation and proliferation. To achieve this, we determined the time course of satellite cell activation and expression of HGF, HGFA, HAI-l, HAI-2 and the MRFs in skeletal muscle, as well as HGF protein in the blood, before and over five days following an acute bout of eccentrically-biased exercise. Eight recreationally active participants (20.6 ± 2.1 y; 180.5 ± 5.2 cm; 81.4 ± 9.8 kg) were recruited for the study. Subjects were required to perform 300 eccentric contractions involving the quadriceps femoris muscles at 180 °/s, over a 60° range of motion with a randomly selected leg. A baseline biopsy (PRE) was taken from the opposite leg. Muscle and blood samples were taken before the exercise (PRE) and at 4 h  (T4), 24 h (T24), 72 h (T72) and 120 h (T120) following the exercise. The exercise protocol resulted in an increase in the number of satellite cells (N-CAM labeled cells), expressed both relative to myofiber number and relative to total myonuclei, between PRE and T4 which was sustained over the time course (p<0.001). Further increases in N-CAM labeled cells, expressed relative to myofibre cross-section, were observed between T4 and T24 (p=0.01) and between T4 and T72 (p=0.002). Myf5 mRNA expression increased significantly from both PRE and T4 by T24 (p=0.04). MyoD mRNA increased significantly from PRE by T4 (p=0.02).
Myogenin mRNA increased significantly at T24 versus PRE (p=0.02). No significant change was observed over time for MRF4. HGF protein increased significantly in serum from baseline (PRE) to T4 (p=0.04). Active HGF protein was detected in skeletal muscle at rest (14.4±1.3 avg IDV/actin avg IDV) and tended to increase from PRE to T24 (p=0.12). HGFA protein increased significantly from PRE to T24 (p=0.04). HAI-2 increased significantly from PRE at T72 (p=0.03) and T120 (p=0.04). HAI-1 protein increased significantly from PRE to T24 (p=0.02). HAI-2 (32 kDa) increased significantly from baseline (PRE) by T24 (p=0.03), and also by T72 and T120 (p=0.02). HAI-2 (28 kDa) protein showed no significant change over time HGF, HGFA, HAI-1, and HAI-2 transcripts were undetected over the time course. We conclude that a single bout of high-intensity exercise is sufficient to activate satellite cells, which may involve both a local and systemic response to exercise-induced injury. Furthermore, we propose that HGF signaling plays an important role in the regulation of satellite cells in the post exercise period.

abstract: Thesis

abstract: Master of Science (MSc)


title: Gas Slag Reaction Kinetics in Slag Cleaning of Copper Slags

contributor:
Coley, K. S.
Materials Science and Engineering

subject: Gas slag, reaction, kinetics, copper slags, gas phase, flowrate

abstract:
The reduction of iron oxide from slag is involved in many processes, such as, bath smelting, EAF steelmaking and copper slag cleaning processes, and it is known to occur via gaseous intermediates. Four possible rate determining steps are involved during the reduction. Among them, these two interfacial chemical reactions, gas slag and gas carbon could ultimately limit the enhancement of these processes.

In this work, the gas slag reaction kinetics in slag cleaning of copper slags has been studied. The dissociation rate of CO2 on the surface of liquid copper slags is measured using an isotope exchange method, where the mass transfer in the gas phase was eliminated by using a sufficiently high gas flowrate.

It is found that, for slag of the FexO-SiO2-Al2O3-Cu2O system, the apparent rate constant remains fixed with Cu2O content from 1-10 wt pct at higher oxygen potentials. The rate constant becomes approximately 2 times higher after metallic copper is reduced from the slag, this is due to the suspension of small metal drops on the slag surface.

The effect of temperature in the range from 1200-1450°C on the rate constants was also studied. The activation energy was 190 kJ/mole for slag of composition 60FexO30SiO2-1 0Al2O3. In the presence of Cu metal~10%, the activation energy was reduced to 122 kJ/mole.

abstract: Thesis

abstract: Master of Engineering (MEngr)


title: The Acute Effects of Arm Ergometry on Affect

subject: acute, effects, affect, arm, ergometry, dual-mode theory, exercise

abstract:
The primary purpose of this study was to test the predictions of the Dual-mode theory using arm ergometry as the exercise modality. It was hypothesized that changes in affect during exercise would be greater in high (105% GET) and low (80% GET) intensity exercise conditions than in a control condition, while differences in affect would be observed between exercise conditions. In addition, it was predicted that during recovery, there would be no differences in affect between the exercise conditions. Study participants were 24 physically active men. A within-subjects design was used. Affect was measured using the Activation-Deactivation Adjective Check List (Thayer, 1986) and the State Anxiety Inventory (Spielberger et al., 1970). Cognitive (i.e., self-efficacy, enjoyment) and physiological (i.e., heart rate, pain, perceived exertion) mediators of the exercise-affect relationship were also examined. Results showed that during exercise, changes in affect were greater in the exercise conditions than the control condition, and affective valence in the exercise conditions declined relative to the control condition. In partial support of the Dual-mode theory, self-efficacy mediated the relationship between below GET exercise and affect, whereas pain mediated the relationship between above GET exercise and affect. During recovery, arousal was higher in the exercise conditions compared to control, affective valence was less positive compared to control, and state anxiety did not differ across conditions. Finally, there were no significant differences
between the two exercise conditions on any of the affect measures. These findings highlight the importance of exercise intensity to the affective benefits of exercise.

abstract: Thesis

abstract: Master of Arts (MA)


title: HMGB1 regulates the nuclear import of huntingtin in a ROS-dependent manner

contributor:
Truant, Ray
Biochemistry and Biomedical Sciences

subject:
Huntington's disease
huntingtin
HMGB1
neurodegeneration
nuclear localization
N17
PY-NLS
ROS
oxidative stress
phosphorylation

abstract: In healthy cells, huntingtin is primarily found in the cytoplasm; however, upon cellular stress, huntingtin is phosphorylated (phospho-huntingtin) at serines 13 and 16 of the amino-terminal N17 domain and shuttled into the nucleus. Such dynamism in nucleocytoplasmic translocation and post-translational modification suggests an important role for huntingtin in Huntington’s disease (HD) pathogenesis as these phenotypes propose possible mechanisms for disease progression. Huntingtin nuclear import is also facilitated by its proline-tyrosine nuclear localization signal (PY-NLS), which harbours a highly conserved intervening sequence specific to the huntingtin gene. This encouraged a proteome investigation to identify potential protein partners of the PY- NLS. Results of this study revealed that high mobility group box 1 (HMGB1), a cofactor of base excision repair, uniquely bound to the wild-type PY-NLS, but not the PY-NLS KK177/178AA mutant. Immunofluorescence microscopy in human telomerase reverse transcriptase (hTERT) immortalized fibroblast cells using HMGB1- and phospho- huntingtin-specific antibodies revealed a promising association between the two, as changes in nuclear levels of HMGB1 positively correlated with nuclear levels of phospho- huntingtin. This relationship was further confirmed by co-immunoprecipitation of HMGB1 by the PY-NLS and N17 domain. Also, when exogenous oxidative stress was introduced, increased interaction between HMGB1 and huntingtin was observed. This suggests that HMGB1 facilitates the nuclear import of huntingtin in a ROS-dependent manner, and thus, presents a novel avenue to a potential therapeutic target in HD pathogenesis.

abstract: Thesis

abstract: Master of Science (MSc)


title: Alternative Approaches to Assessing the Anaerobic-Aerobic Power Ratio; Age Related Changes from Childhood to Early Adulthood

contributor:
Blimkie, Cameron J.R.
Kinesiology

subject: alternative approaches, anaerobic-aerobic, power ratio, age related, changes, childhood, adulthood

abstract:
 The anaerobic-to-aerobic power ratio is a useful tool to evaluate the strengths and
weaknesses of both the aerobic and anaerobic energy systems. The traditional method of
calculation has shown this ratio to increase with age in children and to plateau by late
adolescence or early adulthood. However, by using the traditional approach, the aerobic
component of the ratio is likely highly influenced by anaerobic sources and therefore, may not demonstrate the true proportional changes observed in the respective physiological capacities comprising this ratio with age through childhood and adolescence. The purpose of this study was to examine the age-related development of the power ratio using two new approaches. The lactate threshold (LT) and ventilatory anaerobic threshold (VAT) were identified in 31 competitive male hockey players ranging from 10 to 21 years of age and compared across three discrete age groups. Peak mechanical anaerobic power was obtained from a Wingate test (WAnT) and incorporated into the numerator of the power ratio, while peak mechanical aerobic power was obtained from a modified McMaster all-out progressive test and included into the denominator of the ratio. Mechanical power at the LT and VAT were also identified and integrated into the denominator of the power ratio and results compared to the traditional approach to identify similarities or differences in developmental trends with age. Furthermore, the reliability of the traditional, LT and VAT approaches was examined with retests of six
subjects using intra-class correlation analysis and Method Error analysis. When power ratio approaches were compared among discrete age groups, significant differences (P≤0.05) were found between the youngest and oldest age groups for each of the three approaches. Notwithstanding the trend for progressive increases with advancing age group for all approaches, significant correlations with age were only found for the traditional approach (r=0.36). Finally, the VAT approach was the most reliable (r=0.95; ME=0.13) while the LT and traditional approaches demonstrated strong but non-significant test-retest correlations. Results of this study suggest that the LT and VAT approaches may theoretically be more accurate methods of measuring the power ratio than the traditional approach, as there is likely less anaerobic contribution to the denominator of the ratio. Each of the new approaches demonstrates expected age-related trends, and notwithstanding methodological and sample limitations, the VAT in particular, appears to be a more reliable and accurate means of assessing the power ratio compared to the traditional or LT approach.

abstract: Thesis

abstract: Master of Science (MSc)


title: The Effects of Six Weeks of Isometric Handgrip Training on Blood Pressure, The Autonomic Nervous System and Arterial Stiffness in Newly Diagnosed Hypertensives

subject: six weeks, isometric handgrip training, blood pressure, autonomous nervous system, arterial stiffness, diagnosed, hypertensives

abstract:
 Supervised isometric handgrip training (IHG) has been shown to lower blood pressure (BP) and therefore, may be an effective non-pharmacological treatment for hypertension. The present investigation examined the efficacy of unsupervised IHG to lower BP in patients who were recently diagnosed as hypertensive. Since the mechanisms responsible for attenuating BP remain unclear, this study also investigated the concurrent effects of IHG training on the
autonomic nervous system (ANS) and arterial stiffness.

Eight participants were randomized to the experimental group and the remaining six served as controls. Lifestyle modifications to lower BP were recommended for both groups. In addition, the experimental group completed IHG three times per week for six weeks. IHG consisted of four two-minute
isometric contractions at 30% maximal voluntary contraction using alternate hands, each separated by a one-minute rest period. Pre- (PRE) and post-intervention (POST), BP was measured and the ANS was assessed by baroreceptor sensitivity (BRS) and both systolic and diastolic blood pressure variability (SBPV and DBPV) and arterial stiffness was evaluated by carotid-finger pulse wave velocity (PWV). All measures were assessed during a period of
supine rest and during a 60° passive tilt.

 There were no significant changes in any BP measure from PRE to POST for either the experimental or control groups. There was a non-significant trend toward decreased heart rate (p = 0.065). BRS decreased from PRE to POST in both the experimental (10.7 ± 2.4 mm Hg to 9.7 ± 2.3 mm Hg) and control groups
(8.6 ± 2.1 mm Hg to 7.6 ± 1.5 mm Hg), but there was no difference between groups. SBPV LF:HF was lower at POST than PRE in both experimental (6.8 ± 1.5 to 4.6 ± 1.1) and control (3.4 ± 1.9 to 2.3 ± 0.9), but there were no other differences in any other BPV variable. There were no significant changes in PWV.

 In conclusion, unsupervised IHG did not lower resting BP in newly diagnosed hypertensive patients, so there were no improvements in autonomic indices. There was a decrease in SBPV LF:HF indicating improved sympathovagal balance, but this was likely a result of lifestyle modification rather than IHG. Future studies are necessary to determine appropriate use of IHG as a treatment for hypertension and to verify the mechanisms responsible for BP attenuation with IHG.

abstract: Thesis

abstract: Master of Science (MSc)


title: Effects of 8-Week Isometric Handgrip Exercise on Aortic Distensibility and Central Cardiovascular Responses

subject: 8-week isometric, handgrip exercise, aortic distensibility, responses, cardiovascular, hypertension, heart rate, blood pressure

abstract:
 Recent evidence suggests that isometric handgrip training improves resting arterial blood pressure (BP) in normotensive and hypertensive individuals, however the mechanisms remain elusive. The purposes of the current investigation were to replicate the finding that 8 weeks of isometric handgrip training (IHG) improve resting BP in persons medicated for hypertension, to determine if training could improve aortic stiffness and to examine the acute cardiovascular response to IHG. Seventeen participants were recruited and familiarized with the laboratory and techniques used. Training consisted of 8 weeks of thrice weekly IHG training sessions using a pre-programmed handgrip dynamometer (4, 2-minute contractions separated by 4 minutes rest). Measurements of resting ABP (assessed by automated oscillometry), aortic stiffness (assessed by simultaneous ultrasound and applanation tonometry), and the acute
cardiovascular response (heart rate, blood pressure, rate-pressure product, and cardiac
output) were made at baseline and following 8 weeks of IHG training.

 Following training, there were no differences observed in resting systolic or diastolic systolic blood pressure, resting heart rate or cardiac output. Furthermore, handgrip training did not improve aortic distensibility or reduce stiffness index. The acute responses of heart rate, blood pressure, rate pressure product and cardiac output were not altered with training. In response to an acute bout of IHG there were significant increases seen in heart rate (55±2 to 65±3 BPM, p<0.01), blood pressure (systolic: 137.2±3.7 to 157.1±7.3; diastolic: 77.8±3.4 to 92.2±4.8 mmHg, p<0.01) and rate-pressure product (7369.4±302.0 to 10159.0±666.6 beatsxmmHg/min). Thus isometric handgrip training is a safe modality which does not appear to alter the stiffness of the proximal aorta or generate a significant cardiovascular strain in the acute phase.

abstract: Thesis

abstract: Master of Science (MSc)


title: Peak Discharge Estimation for Rural Areas Using APSWM and OTTHYMO Models

contributor:
Guo, Yiping
Civil Engineering

subject: Peak discharge, Rural areas, Using APSWM, OTTHYMO models, Streamflow data, Precipitation run-off

abstract:
Traditional methods for flood estimation can be categorized as (1) simplified
methods, e.g., regression analysis, (2) frequency analysis of streamflow data, (3)
design storm-based precipitation-runoff modeling, and ( 4) continuous
precipitation-runoff simulation modeling. The new approach - the Analytical
Probabilistic Stormwater Model - was developed as an alternative to provide an
efficient way of getting realistic estimation of peak discharges of desired frequencies
for use in stormwater management of urban areas. To extend APSWM's application to
rural areas, a series of comparisons were made between the calibrated design
storm-based OTTHYMO model results, frequency analysis results and APSWM
results for the Ganaraska River watershed. Special considerations were given to the
transformation of the input parameter values of OTTHYMO model to those of
APSWM. Comparable results were obtained for large floods, while APSWM may
underestimate peak discharges of low return periods. Upon further testing and
development, APSWM may be used for large rural areas.

abstract: Thesis

abstract: Master of Engineering (MEngr)


title: Monitoring and Advising System for Iodine Status

contributor:
Garland, W.J.
Engineering Physics

subject: monitoring, advising system, iodine, status, reactor, concentration, MASIS

abstract: Iodine-125 is produced from Xe-124 at McMaster Nuclear Reactor (MNR) for medical applications. Excessive amounts of this isotope in the air of the reactor site can be hazardous especially for the staff members who are continuously working at the reactor building. Therefore there is a critical need to monitor the concentration of iodine released to the air. In the previous iodine monitoring system available at MNR, there were several technical and practical problems. Consequently a new monitoring system was designed to overcome the previous problems and to provide with further facilities for the staff. The system is developed in the LabVIEW1 platform and is easily maintainable. The external data acquisition board LabJack is used to transfer the data to the PC. Briefly, by using radiation monitoring techniques and statistical methods, a computerized embedded system is designed to keep the MNR a safe place for operators and visitors. This thesis examines in detail the design and implementation of the new monitoring system, MASIS.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: ROLE OF THE IRE/XBP-1 PATHWAY IN CIGARETTE SMOKE AFFECTED MACROPHAGE POLARIZATION IN VITRO

contributor: Medical Sciences (Molecular Virology and Immunology Program)

subject: ER Stress, Cigarette smoke, IRE-1, UPR, macrophage polarization, Chronic Lung Disease

abstract:
Cigarette smoke contributes to 90% of lung cancer cases and 80% of COPD cases. These concerns loom large as lung cancer represents 13% of all cancer deaths and estimates report by 2020 COPD will be the third leading cause of death in the world. The master regulator of the ER stress response, IRE-1, in the context of cigarette smoke exposure lacks study. Interestingly, its downstream pathways are activated. In fact, the 2014 Surgeon General’s report on the health consequences of smoking highlighted the endoplasmic reticulum (ER) stress response as a potential mechanism leading to the development of lung cancer and Chronic Obstructive Pulmonary Disorder (COPD).
Following acute cigarette smoke exposure, mouse lung homogenates exhibited increased levels of XBP-1 along with downstream mediators of IRE-1 activation— GRP-78 and CHOP. Specifically observing macrophages, an important immune cell and source of acute inflammation, cigarette smoke induced activation of IRE-1/XBP-1 pathway through splicing of XBP-1 mRNA. However, upon assaying for pro-inflammatory cytokines we were unable to determine that cigarette smoke directly caused inflammation in vitro. Furthermore, cigarette smoke inhibited the activation of M2 macrophages, an anti-inflammatory and tissue healing subset seen through CCL18 inhibition.
A majority of M2 and M1 macrophage markers were decreased from IRE-1/XBP-1 inhibition. This suggests a different phenotype than classical M1 or M2 polarization being induced by cigarette smoke. In addition, it suggests the IRE-1/XBP-1 pathway having a robust role in controlling gene expression and balance of cellular proteomics.

abstract: Thesis

abstract: Master of Science (MSc)

abstract:
Cigarette smoke exposure damages the lungs and over time places the user at risk for increased infections, progressive decreases in lung function and cancer.
A specific cell of the immune system and found in the lungs, macrophages or “Big Eater” cells, responds first by picking up debris and responding to harmful foreign substances by releasing proteins signaling the immune system to become activated.
Within all animal cells, an organelle called the Endoplasmic Reticulum (ER) manufactures a third of proteins produced allowing the cell to adapt to foreign substances, including cigarette smoke. Cigarette smoke could cause the ER, a plastic organelle, to change in size and function at a heightened level due to activation of a sensing protein integrated in the ER, Inositol Requiring Enzyme-1 (IRE-1).
Both activation of the ER and cigarette smoke causes macrophages to behave as “tissue-healing” or M2 subsets that release factors promoting reconstruction of the lungs; alternatively, M1 macrophages fight diseases and promote further inflammation. Using genetic analysis of macrophages exposed to cigarette smoke in culture dishes and analyzing the proteins secreted, we determined cigarette smoke inhibits M1 macrophages and the “tissue-healing” subset, while increasing adhesion molecule expression.
Overall, cigarette smoke affected the polarization of M1 and M2 phenotype, analyzed through proteins and genes expression. We observed an increase in sXBP-1, indicative of IRE-1/XBP-1 pathway activation, from cigarette smoke extract exposure in macrophages.  However, the use of IRE-1 inhibitors increased ER stress markers while affecting M1 and M2 markers. This suggests ER compensation from the use of inhibiting one arm of the ER stress response.


title: Identification of Markers of Profibrotic Macrophages Shared Between Human and Murine Systems, and Their Relevance to Systemic Sclerosis

title: Markers of Profibrotic Macrophages and Their Relevance to Scleroderma

contributor:
Ask, Kjetil
Medical Sciences

subject:
Macrophages
Scleroderma
Fibrosis
Systemic Sclerosis
Clec7a
Bioinformatics
M2 macrophages

abstract: Systemic sclerosis (SSc), or scleroderma, is a complex, rare disease of unknown etiology. Macrophages constitute a large portion of the immune cell infiltrate in the skin of patients with SSc, and are an important target of study. Particularly, the M2 macrophage has been implicated scleroderma and other fibrotic diseases as a key contributor to fibrotic processes. However, the definition of an M2 macrophage appears to change with context, and is poorly elucidated in different species. With varying characterizations between species and disease models, there is a need to establish some consensus on how to identify this macrophage in an uniform manner across species. We used a bioinformatic approach to identify a unique gene signature for the M2 macrophage phenotype, which is shared between human and mouse systems. We were able to confirm a 7-gene subset of this theorized signature using human and mouse in vitro systems. In addition, we selected one of the identified genes, Clec7a, and characterized its expression at the protein level on different macrophage phenotypes, across several human and mouse models. Our data show that Clec7a is a more selective marker of murine M2 macrophages than current reference markers, and is useful in human models as well. Using our M2-specific gene signature, we also identified a potential inhibitor of the signature and showed its effects on M2 marker expression. Finally, we showed some preliminary work into Clec7a expression in skin tissue from patients with scleroderma. Overall, our data suggest that Clec7a may be a valuable addition to the panel of markers used to characterize M2 macrophages and distinguish between macrophage phenotypes, and perhaps provide clarity into the development and function of the M2 macrophage. Better understanding of the M2 macrophage would ultimately be useful to the study of fibrotic diseases such as scleroderma, wherein this macrophage phenotype may be a viable target for antifibrotic therapy.

abstract: Thesis

abstract: Master of Science (MSc)


title: Microbial Contribution to Proteolytic Homeostasis in the Gut

contributor: Medical Sciences (Division of Physiology/Pharmacology)

abstract: Proteases mediate a vast array of physiological functions, and their enzymatic activity must be tightly regulated by protease inhibitors. Proteolytic homeostasis is crucial in the gastrointestinal tract, and disturbances are associated with several gastrointestinal disorders including irritable bowel syndrome (IBS), inflammatory bowel disease (IBD), colorectal cancer (CRC), and celiac disease (CeD). Perturbed proteolytic balance is hypothesized to contribute to disease pathophysiology by inducing structural and functional changes in the intestinal barrier and promoting inflammation, and modulation of this proteolytic imbalance through delivery of protease inhibitors represents a therapeutic target. Studies addressing proteolytic homeostasis in the gut have focused on proteases and protease inhibitors produced by the host, while largely ignoring the potential contribution of the microbiota. This is a major oversight given the wide repertoire of proteases and protease inhibitors produced by the intestinal microbiota, as well as the strong association between alterations in microbiota and several chronic intestinal disorders. We hypothesized that increased microbial proteolytic activity can elicit deleterious effects on the host, while microbial protease inhibitors such as those produced by probiotic strains may have a therapeutic role in gut inflammatory disorders. The aims of this thesis were: (1) to investigate the contribution of microbial proteolytic activity to the processes underlying disease pathogenesis, and, (2) to test the therapeutic potential of bacterial probiotic strains naturally expressing protease inhibitor genes. We first employed a reductionist model wherein gnotobiotic mice were colonized with microbial communities expressing a specific proteolytic functional phenotype in vitro. Colonization of germ-free mice with microbiota with high proteolytic activity resulted in increased systemic translocation of live bacteria and low-grade inflammation. Some of these effects were mitigated after treatment with the probiotic B. longum strain expressing its serine protease inhibitor (Srp). Moreover, treatment with this Srp-expressing B. longum strain prevented immunopathology in a mouse model of gluten sensitivity. Together, these results demonstrate the relevance of microbiota-derived proteases and protease inhibitors in the modulation of host responses and gut homeostasis.

abstract: Thesis

abstract: Master of Science (MSc)


title: Electron Cyclotron Resonance Chemical Vapour Deposition of SiOxNy Films for Use in Flat Panel Displays

contributor:
Mascher, Peter
Engineering Physics

subject: electron cyclotron, resonance, chemical, vapour deposition, films, flat panel, displays, silicon

abstract:
 Thin silicon based films were produced using low temperature (less than 60° C) electron cyclotron resonance plasma enhanced chemical vapour deposition (ECR PECVD). These films were examined for suitability in flat panel display applications. SiOxNy films were tested for use as insulating films in thin film electroluminescent (TFEL) devices. The ECR PECVD method was found to be suitable when the plasma was created using pure nitrogen (as opposed to argon) in high ratios to the silane precursor.

 Hydrogenated silicon films were also produced and evaluated for their suitability as semiconductor layers in thin film transistors (TFTs). The silicon films were subject to nickel induced crystallization. The silicon films were found to crystallize at low temperatures, (<950° C) in the presence of nickel. These films were used to produce prototype metal insulator semiconductor (MIS) capacitors and TFTs.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: Imagining the Possibilities: Investigating the Effects of a Possible Selves Intervention on Self-Regulatory Efficacy and Exercise Behaviour

contributor:
Ginis, K. A. Martin
Kinesiology

subject: Possible selves intervention, exercise behaviour, self-regulatory efficacy, inactive individuals

abstract:
The present study was conducted to determine the effect of a possible selves
intervention on self-regulatory efficacy and exercise behaviour. Participants were 19 men
and 61 women (Mage= 21.43, SD = 3.28) who reported exercising less than 3 times per
week. Participants were randomly assigned to a control condition, a hoped-for possible
selves intervention condition, or a feared possible selves intervention condition. Participants in the hoped-for and feared possible selves conditions completed an activity
where they imagined themselves in the future as either healthy, regular exercisers or
unhealthy, inactive individuals, respectively. Participants in the control group completed
a quiz about physical activity. Measures of self-regulatory efficacy (scheduling, planning,
goal-setting, and barrier self-efficacy) were taken immediately before and after exposure
to the intervention. Participants who received a possible selves intervention reported
greater exercise behaviour 4 weeks post-intervention than participants in the control
group (p = .05). Furthermore, planning self-efficacy was found to partially mediate the
effect of the possible selves intervention on exercise behaviour. These findings suggest
that possible selves may play a role in increasing exercise behaviour among inactive
individuals. Future research is warranted to examine the role of possible selves
interventions in increasing exercise behaviour and to determine which other variables
may mediate this intervention-exercise behaviour relationship.

abstract: Thesis

abstract: Master of Science (MSc)


title: The Portevin-Le Chatelier Effect and Shear Band Formation in AA5754 Aluminum Alloy

contributor:
Wilkinson, David S.
Niewczas, M.
Materials Science and Engineering

subject: Portevin-Le Chatelier effect, shear band, formation, aluminum, alloy, failure mechanism, plastic deformation, strain rate, tensile tests

abstract:
 The use of AA 5754 Al-Mg alloy for automotive applications is limited by its rapid shear failure process, due to shear banding. This failure mechanism is further complicated by the presence of inhomogeneous plastic deformation, so-called Portevin-Le Chatelier (PLC) effect, during deformation. Therefore, the purpose of this study was primarily to investigate the impact of Portevin-Le Chatelier (PLC) banding towards shear banding in this commercial alloy. The second objective was to study the PLC banding as a function of prior deformation under positive strain rate sensitivity condition.

 The experimental work involved pre-straining experiments coupled with a non-contact strain measurement technique. Pre-straining experiments were carried out by deforming the sample at 223 K, at which the PLC effect is significantly suppressed, up to a prescribed amount of true strain prior to room temperature testing. A non-contact strain measurement technique, based on digital image correlation (DIC), was utilized in order to observe PLC band behavior during tensile tests at room temperature and subsequently to measure the amount of plastic strain carried within the band.

 The results showed the appearance of random nucleation deformation bands, associated with type B PLC banding, with short distance propagation during constant
strain rate tensile test at room temperature. A change in the nature of PLC banding, marked by distinct band propagation, was observed once a critical amount of pre-strain is given. However, there is no evidence of a relationship between two existing phenomena, PLC banding and shear banding, in this alloy.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: Development of in-situ flow electrochemical Scanning Transmission X-ray Microscopy

contributor:
Hitchcock, Adam
Chemistry

subject:
Electrochemistry
STXM
MEMS
3D Printing
NEXAFS Spectroscopy
Copper Electrochemistry

abstract: Understanding electrically activated processes at electrode-electrolyte interfaces is needed to improve many technologies, including energy conversion, semiconductor devices, bio-sensors, corrosion protection, etc. In-situ spectro-electrochemical studies based on a wide range of spectroscopies are particularly useful. Scanning Transmission X-ray microscopy (STXM) is a synchrotron-based technique which measures near-edge X-ray absorption fine structure (NEXAFS) with high spatial resolution. In addition to information on morphology, STXM also provides chemical state analysis using the X-ray absorption data, which makes in-situ STXM studies of electrochemical process of special interest. This thesis reports ex-situ and in-situ STXM based qualitative and quantitative studies on copper (Cu) electrodeposition and electrostripping. The influence of electrolyte pH on the distribution of Cu(I) and Cu(0) species electrodeposited from aqueous CuSO4 solutions was studied. An instrument capable of performing in-situ flow electrochemical STXM studies was designed and fabricated. The performance of this device was evaluated for in-situ Cu electrodeposition studies. Findings based on ex-situ and in-situ STXM studies are discussed. Suggestions are made for further instrumentation improvements.

abstract: Thesis

abstract: Master of Science (MSc)