title: The effects of social-comparative feedback during motor skill acquisition in highly-motivated learners: Applications to medical education

contributor:
Lyons, James
Kinesiology

subject:
motor learning
social-comparative feedback
medical trainees
technical skills
motivation
self-efficacy
skill acquisition
medical education
health professions education research
feedback
suturing
novices

abstract:
Social-comparative feedback (i.e., providing a learner with information regarding his/her performance relative to a group average) has been shown to influence a learner’s psychological and behavioural outcomes during motor skill acquisition (Avila, Chiviacowsky, Wulf, & Lewthwaite, 2012; Eliasz, 2012; Lewthwaite & Wulf, 2010; McKay, Lewthwaite, & Wulf, 2012; Stoate, Wulf, & Lewthwaite, 2012; Wulf, Chiviacowsky, & Cardozo, 2014; Wulf, Chiviacowsky, & Lewthwaite, 2010, 2012; Wulf & Lewthwaite, 2016). This research indicates that motor skill acquisition is facilitated when learners believe they are performing better than the average, regardless of their actual performance. It has been suggested (Wulf & Lewthwaite, 2016) that a better-than-average mindset enhances psychological factors such as self-efficacy and motivation and in turn, actual behaviour. However, there is also evidence to suggest that self-efficacy (having state-like properties) and motivation (having both state and trait-like properties) are related in terms of their affective influence on learning (Bandura, 1997; Schunk, 1990, 1991, 1995) but the relationship between the two constructs and its subsequent outcomes remain unclear. Even though individual differences in motivation have been suggested to influence self-efficacy beliefs, they have been largely ignored in this line of research. There is also evidence to suggest that learners possessing high levels of motivation (whether that may be at a trait or state level) may not interpret feedback in the same manner (Aronson, 1992; Festinger, 1957; Frey, 1986; Harmon-Jones, 2012; Harmon-Jones & Harmon-Jones, 2002; Harmon-Jones, Harmon-Jones, Fearn, Sigelman, & Johnson, 2008; Harmon-Jones & Mills, 1999; Harmon-Jones, Schmeichel, Inzlicht, & Harmon- Jones, 2011; Steele, 1988). Therefore, the goal of this dissertation is use both theoretical and applied perspectives to examine the degree to which social- comparative feedback affects psychological and behavioural outcomes in highly- motivated learners (e.g., medical trainees) learning procedural skills.
Independent of actual performance, we provided manipulated feedback information to novice pre-clerkship medical trainees while they were learning motor skills to suggest that they were performing better or worse than the average. The first study used a basic sequential key-press learning task (Eliasz, 2012) and a basic suturing task to explore the role of social-comparative feedback in medical trainees and tested whether features of the task were important (i.e., basic laboratory task or technical skill task) during the interpretation of this feedback. The second study used the same experimental paradigm to extend our results to a relevant medical education context (i.e., medical trainees learning basic suturing techniques). The final study examined whether the credibility of the feedback provider (i.e., expert versus peer) played a role in how social-comparative feedback was being internalized by novice medical trainees.
Our initial study demonstrated that, compared to those receiving positive or no social-comparative feedback, medical trainees receiving negative social- comparative feedback during motor skill acquisition had significant difficulties in learning both the laboratory and technical skill task. These findings suggested that compared to other learners, novice medical trainees (a subset of highly-motivated learners), responded differently to social-comparative feedback. The second study replicated this pattern and revealed that medical trainees receiving below-average feedback during technical skill acquisition experienced significant detriments to their performance, learning and self-efficacy. Our final study found that regardless of the feedback source (hypothetical expert versus another peer), the experience of receiving negative social-comparative feedback impacted self- reported psychological measures and the immediate performance of a basic surgical technique.
This dissertation provides, to the best of our knowledge, the first demonstration that medical trainees, a subset of highly-motivated learners, interpret social-comparative feedback differently than other learners studied in the literature. More specifically, receiving positive social-comparative feedback did not facilitate the learning process as found in previous studies with non-medical learners, while the delivery of negative social-comparative feedback, irrespective of task or feedback provider, was psychologically and behaviourally detrimental to novice medical trainees learning motor skills.

abstract: Dissertation

abstract: Doctor of Philosophy (PhD)

abstract: This dissertation includes three original studies designed to examine the effects of social-comparative feedback during skill acquisition in highly- motivated learners (e.g., medical trainees). Regardless of actual task performance, novice medical trainees who were provided with feedback during the learning process indicating that they were performing worse than the group average, experienced significant detriments to their psychological and behavioural outcomes. This effect was present regardless of the task being learned (i.e., key- pressing or suturing) or who was delivering the feedback (i.e., a hypothetical ‘expert’ or ‘peer’). Receiving better-than-average feedback did not result in any additional psychological and behavioural benefits. Contrary to the research with non-medical students, where “you are above-average” social-comparative feedback facilitates learning and “you are below-average” social-comparative feedback is no different than a control condition, these studies suggest that the experience of receiving below-average feedback during the learning process can be detrimental for highly-motivated novice learners. These findings are important to consider in both the context of feedback delivery and remediation as they provide evidence that novice medical trainees, regardless of the task and feedback provider, experience difficulty in receiving information that they are performing relatively poorly compared to their peers.


title: DERIVING MESENCHYMAL STEM CELLS-LIKE CELLS WITH IMPROVED ADIPOGENIC CAPACITY FROM PLURIPOTENT STEM CELL SOURCES

contributor:
Szabo, Eva
Biochemistry and Biomedical Sciences

abstract:
Mesenchymal stem cells (MSCs) have been used for tissue repair, tissue regenerative purposes, to understand cell biology of various cell types, and as an in vitro model of a disease in vitro. Primary MSCs isolated from adult human tissue (i.e. adipose tissue), have been shown to have limited proliferative and differentiation capacity over passages in vitro. Due to the limited availability of tissue donors, it is difficult to obtain sufficient primary MSCs for therapeutic purposes. Therefore, pluripotent stem cells (human embryonic stem cells, hESCs, and induced pluripotent stem cells, iPSCs) have been used an alternative source to obtain the unlimited source of MSC-like cells. These cells are reported to have similar morphological and phenotypical characteristics but have lower differentiation capability compared to primary MSCs. Additionally, the protocols used for derivation of MSC-like cells from PSC sources are lengthy, expensive, and labour intensive.
In this study, I established a method for derivation of MSC-like cells from the cells surrounding H9 hESCs and a-iPSCs (iPSC-derived by reprogramming adipose tissue-derived stem cells (ADSCs)) through a simple trypsinization step. These MSC-like cells exhibited typical fibroblastic morphology and MSC surface marker profiles akin to bonafide adult MSCs, such as ADSCs. Compared to other studies, this protocol is more time and labour efficient, and it results in the derivation of significantly more (60%) lipid droplets forming cells. However, further characterization of these cells as adipocytes is necessary, given that their differentiation capacity remains limited when compared to ADSCs.
To improve the differentiation capacity of the MSC-like cells derived from H9 hESC or a-iPSCs, I explored: 1. the role of two transcription factors, peroxisome proliferator-activated receptor γ2 (PPARγ2) and Krüppel-like factor 4 (Klf4), both of which have been shown to enhance adipogenesis in the murine system; and 2.  the effect of culture media used for adipocyte differentiation. Through these studies, I discovered that neither Klf4 nor PPARγ2 induction improved adipocyte development in my human system. Accordingly, I did not observe an increase in the adipogenic capacity of the MSC-like cells regardless of the method by which Klf4 was induced (ectopic expression or chemical induction using IBMX), or through induction of PPARγ2 using dexamethasone. However, my studies did show a significant improvement in the appearance of lipid droplet containing cells, akin to adipocytes, upon culturing the MSC-like cells with the specific concentration of MEF (Mouse Embryonic Fibroblast)-condition media compared to well-defined media that have been used for prior differentiation protocols.
Overall, compared to ADSCs, H9-MSCs and a-iPSC-MSCs displayed a unique expression pattern of MSCs and early epithelial to mesenchymal transition (EMT) genes, suggesting further analysis of H9-MSCs and a-iPSC-MSCs at global gene expression and an epigenetic level is required to improve quality of these cells to match that of adult MSCs, such as ADSCs. Additional optimization of H9-MSCs and a-iPSC-MSCs differentiation protocols is also necessary to ensure that the MSC-like cells are following the appropriate MSC differentiation trajectory, allowing us to obtain a bona fide MSC with mature adipocyte differentiation capacity, similar to that derived from ADSCs.

abstract: Thesis

abstract: Master of Science (MSc)


contributor:
Murphy, K.L.
Civil Engineering

abstract: Title: Variations of Axial Mixing in an Aeration Tank, Author: Peter L. Timpany, Location: Thode

abstract:
The axially dispersed plug flow model was used to study the
variations of axial mixing in a laboratory model aeration tank, with
variations of temperature, air flow rate, and water flow rate. The
effect of geometry was also considered briefly by comparing two different
width to depth ratios. Other theoretical models used to describe
an aeration tank were examined by comparing the predicted
theoretical tracer out-put with the experimental out-put.

Full scale field tests were made on an aeration tank and the
results compared to the laboratory model.

abstract: Thesis

abstract: Master of Engineering (ME)


title: "We're all in it together"" The experiences of women aging in place: The case of Searchmont, Ontario

contributor:
Zhou, Rachel
Social Work

abstract: This ethnographic case study of the experiences of older women aging in place in Searchmont, a community with a population of 293 people in northeastern Ontario, has three objectives: 1) to discover the experiences of older women in Searchmont, 2) to explore the connection between women and their community, and 3) to draw conclusions about the structural context of aging in a rural community in northern Ontario. With a growing number of older adults moving into rural communities, or remaining in rural communities into older age, it is a timely exploration. Current policy trends and service restructuring are especially harmful toward vulnerable groups, including older women living outside of the urban context. Cuts to rural services, the privatization of services, and an increased reliance on informal support networks to meet the demands of an aging population create barriers to aging in place. Current trends result in patchwork transit solutions, limited access to information and services, and housing concerns. These factors impact the health and wellbeing of rural-dwelling older women. In addition to large-scale trends, geographic context plays an important role in determining the level of support for older women in rural areas. Aging in place, critical feminist gerontology, and ecological systems theories were used to conduct this case study. The subject of the study includes a history of Searchmont and findings from interviews with five older women living in the community, highlighting the intersection of age, gender, and rural identity. The participants revealed the importance of community fluctuations and meso-level concern for community cohesion into the future. The role of gender in family and community, and level of activity as determined by health were cited as contributors to community sustainability.

abstract: Thesis

abstract: Master of Social Work (MSW)


title: Reading Practices for Indigenous Literatures:

title: Exploring Impossible Moments in Works by Richard Wagamese and Lee Maracle

contributor:
Coleman, Daniel
English and Cultural Studies

subject: Indigenous literature

abstract: This project explores ways of engaging with "impossible moments" that unsettle our reading practices.

abstract: This project arose out of restlessness, on my part, regarding how to read and engage with elements in Indigenous literatures written in Canada, which I could hitherto label as supernatural occurrences. Indeed, my Euro-Western literary education has been unable to provide appropriate tools for profoundly exploring the supernatural occurrences that I was encountering in the literature—a limitation that is made clear by scholars like Vine Deloria Jr. (Sioux), whose work calls for considering origin stories as literally possible. Through this thesis, I re-conceptualize these “supernatural” occurrences as “impossible moments”—a term that I use to avoid the connotations of Euro-Western rationalist nomenclature while also remaining aware that I read from an outsider position. My literary archive consists of Richard Wagamese’s (Anishinaabe) novel Keeper ’n Me (1994), his autobiographical book For Joshua (2002), Lee Maracle’s (Stó:lō) novel Ravensong (1993), and its sequel Celia’s Song (2014). Through the project, I establish two ethical, self-reflexive reading practices: one considers my active participation as a reader within the narratives and the other attends to my role as a reader in the “real” world. These reading practices are established both within the body of the thesis, as well as in extensive meditations within the footnotes. As an outsider, I employ my reading practices with the intention of bringing awareness to the limitations of Western literary reading practices, while at the same time not assuming an authoritative voice. Particularly important for my explorations of impossible moments is Daniel Heath Justice’s (Cherokee) principles of “kinship,” a term that identifies relational responsibilities between all living things. Utilizing the principles of kinship throughout this project allows me to demonstrate that impossible moments occur through narrations of the relational engagements that exist between all living things and the characters’ spiritual practices.

abstract: Thesis

abstract: Master of Arts (MA)

abstract: This project presents close readings of what are conceptualized as “impossible moments” in four literary works : Richard Wagamese’s (Anishinaabe) books Keeper ’n Me (1994) and For Joshua (2002), as well as author Lee Maracle’s (Stó:lō) novels Ravensong (1994) and its sequel Celia’s Song (2014). The term “impossible moments” may be understood as characterizing unsettling reading experiences, particularly those that leave the outside (i.e. non-local and, or non-Indigenous) reader on unfamiliar ground regarding how best to interpret the “impossibilities” that occur within a given narrative. The critical framework in this project demonstrates that  “impossibilities” in Wagamese and Maracle’s works are expressions of kinship between all living things (i.e. humans, the land, the animals, and spirits) as well as expressions of spiritual traditions and ceremonies. Indeed, this project demonstrates the need to reassess our reading practices to encompass differentiated ways of knowing.


title: Multi-Agent Distributed Graph Traversal

contributor:
Bonakdarpour, Borzoo
Computing and Software

subject:
multi-agent
distributed
graph
traversal
algorithms
decentralized
optimization
Unmanned Aerial Vehicles
cost-effective
autonomous

abstract:
The industry of the civil Unmanned Aerial Vehicles (UAVs) has been growing rapidly
in past few years. In many scenarios, accomplishing a task using a single UAV is
either not cost-effective due to the size of the project or not even feasible due to
the existence of unforeseen environment conditions and constraints (e.g., weather
conditions and/or physical obstacles). This limitation motivates the need to move to
solutions that incorporate a network of autonomous UAVs that carry out a joint and
coordinated mission.
This thesis introduces a multi-agent system and related algorithms that solve the
graph traversal problem in a distributed and decentralized manner while optimizing
a set of costs. The environment is modelled as a graph where every node is the point
for the agents to accomplish some task or to distinguish the point as an obstacle
where traveling is not possible. The online distributed algorithms are implemented
on a network of UAVs and we report the results of rigorous simulations and real
experiments with a network of UAVs. The results clearly validate our claim that a
network UAVs can be effectively employed to accomplish a given task.

abstract: Thesis

abstract: Master of Science (MSc)


title: A Structural and Enzymatic Characterization of Purified Human Diacylglycerol Kinase Epsilon

title: Purification and Characterization of Diacylglycerol Kinase Epsilon

contributor:
Epand, Richard
Biochemistry

subject: Membrane Protein Biochemistry

abstract: Diacylglycerol kinases (DGK’s) tightly regulate the intracellular levels of diacylglycerol (DAG) and phosphatidic acid (PA). DAG is an important intermediate in lipid biosynthetic pathways and acts as a lipid second messenger in a number of signaling pathways. Similarly, since PA serves as a potent signaling lipid and is a precursor for lipid biosynthesis, intracellular PA levels must be tightly regulated. There are ten isoforms of DGK in mammals, but we have decided to focus solely on the epsilon form (DGKε) in this work. DGKε is the only isoform that shows specificity for the acyl chains of its DAG substrate; as a consequence, it contributes to the dramatic enrichment of cellular lipids with sn-1 stearoyl and sn-2 arachidonoyl. The most notable example is the highly enriched bioactive lipid 1-stearoyl-2-arachidonoyl phosphatidylinositol. We have purified active human DGKε to near homogeneity and thoroughly characterized its stability as well as examined its secondary structure with CD. We also purified a truncated form (DGKε Δ40) that shows increased stability compared to the full-length protein. Our purified fractions are well suited for a wide range of exciting applications and studies. We have begun incorporating DGKε into liposomes in order to develop a liposome-based assay, which would be a dramatic improvement over the presently used micelle-based assay. This purification also allows for high throughput screens of chemical compounds to test for a specific inhibitor. These studies will reveal valuable information about the structural and functional properties of DGKε and will aid in the development of therapies for DGKε-related diseases.

abstract: Thesis

abstract: Master of Science (MSc)


title: A Time-Dependent Description of In-Core Gamma Heating in the McMaster Nuclear Reactor

contributor:
Luxat, John
Day, Simon
Engineering Physics

subject:
gamma heating
in-core
point kinetics
radiation transport

abstract:
Calculating or predicting the total in-core nuclear heating is a difficult tast.  Full-core models can be constructed in a Monte Carlo code, such as MCNP6 or TRIPOLI4, and will allow an analyst to calculate the prompt-gamma heating at any given in-core location; however, such codes are generally unable to track the activated or fission-product isotopes and therefore the delayed-gamma sources can't be included in such a model.

Some analysts have coupled Monte Carlo transport codes to burnup codes in an effort to include delayed-gamma sources, but the solutions tend to be reactor specific, time-independent and a lot of work.  New ideas are required to calculate the total time-dependent in-core nuclear heating.

Within this report, two new models have been derived: the nuclear heating equation, and the coupled neutron and nuclear heating point kinetics (NHPK) equations.  These models can be used to calculate the time and position-dependent in-core heating.  The nuclear heating equations are generalized expressions of the nuclear heating in a volume of interest, within an arbitrary geometry; these equations use Monte Carlo tallies as coefficients and treat the geometry's scalar neutron flux within as the independent variable.  The NHPK model describes the nuclear heating in a volume of interest, within a critical assembly by coupling nuclear heating to the famous neutron point kinetics equations.

A SCK-CEN gamma thermometer (GT) was commissioned in a materials testing reactor (MTR), the McMaster Nuclear Reactor (MNR), to measure the dynamic in-core nuclear heating in two locations.  The nuclear heating equation was used to calculate self-heating of the SCK-CEN GT by neutron capture reactions.  This calculation used CapGam and IAEA PGAA prompt-gamma emission data; delayed-particle emission data from NuDat 2.6 was also employed.  Analysis of the GT's signal resulted in a quantitative description of the dynamic delayed-gamma heating in MNR, and provided the coefficients for the NHPK model.

The NHPK model is capable of reproducing the measured time-dependent nuclear heating, and therefore should also be capable of predicting in-core nuclear heating as a function of reactor power.

abstract: Dissertation

abstract: Doctor of Philosophy (PhD)


title: THE COST OF HORMESIS

title: TRADE-OFFS IN AN ENERGETICALLY CONSTRAINED ENVIRONMENT: EMBRYONIC DEVELOPMENT OF THE LAKE WHITEFISH (COREGONUS CLUPEAFORMIS)

contributor:
Boreham, Douglas R.
Wilson, Joanna Y.
Medical Physics

subject:
hormesis
trade-offs
growth
radiation
temperature
whitefish
Coregonus clupeaformis
gamma radiation

abstract:
L'exposition à des  niveaux faibles de radiation ionisante est connue pour déclencher une réponse adaptative qui inclut la stimulation immunitaire et l'augmentation des effets protecteurs à long terme incluant l’amélioration de la détection et la réparation de dégâts causés à l’ADN, la croissance renforcée  et la longévité. Tandis que les aspects hormetique de la réponse adaptative augmentent clairement la santé physique en présence de stress environnementaux, ils doivent la diminuer dans des conditions environnementales normales parce que les mécanismes biologiques responsables ne sont pas maintenus dans un état amélioré, mais exigent plutôt une certaine forme d'exposition sensibilisante. Il a été suggéré que la stimulation de la réponse adaptative pourrait être métaboliquement coûteuse cependant aucune mesure directe du coût métabolique de la croissance stimulée de radiation a été précédemment essayée.
Cette thèse a évalué si la croissance stimulée de radiation du grand corégone (Coregonus clupeaformis) est accompagnée par un compromis dans l'efficacité métabolique ou par une augmentation durable de demandes énergiques. L'exposition à un régime fractionné de radiation ionisante d'une source de 137Cs s’est avéré stimuler considérablement la croissance dans des embryons du grand corégone comparés aux contrôles avec une augmentation correspondante de la consommation de jaune. Cependant, les mesures d'efficacité métabolique utilisant une série de temps de poids secs non préservés ont montré que la croissance stimulée était non-accompagnée par une réduction de l'efficacité métabolique.
Une température moyenne exponentiellement transformée a été utilisée comme un point de référence quantitative pour évaluer la vulnérabilité du développement des embryons du grand corégone à la disparité phénologique. Le temps d’éclosion  différait des prédictions de  références sous des régimes thermiques asymétriquement variables. Les écarts ont été attribués aux embryons grandissant à dans un stade plus avancée de développement sous des températures basses.  Le terme heterograde est proposé pour décrire la dépendance thermique dans  l'étape d’éclosion qui peut avoir évolué  comme un mécanisme pour synchroniser l’éclosion  de larves viables pour l'augmentation de la densité de  zooplancton qui accompagne le débâcle printanière  Un modèle de prédiction incorporant l’éclosion heterograde a permis une amélioration significative dans l’exactitude des prédictions comparé aux modèles précédents.
L'efficacité énergique a une importance particulière pour le grand corégone comme il a une des périodes d'incubation naturelles les plus longues pour un poisson d'eau douce, avec des températures d'incubation les plus basses et avec des œufs seulement 10 % de la taille de la plupart des salmonidés non-coregonine. L'évolution de mécanismes pour synchroniser l’éclosion au démantèlement de couverture de glace hivernale met en évidence la vulnérabilité du grand corégone  à la disparité phénologique  et ce par le développement accéléré qui cause l’éclosion asynchrone des embryons avec le démantèlement de la couverture de glace d'hiver ou par une augmentation durable de demandes énergiques qui augmentent leur vulnérabilité à la famine. L'absence de compromis mesurable dans l'efficacité métabolique indique ce dernier comme un coût général plausible de hormesis.

abstract:
Exposure to low levels of ionizing radiation is known to trigger an adaptive response that includes immune stimulation and the up-regulation of long-lasting protective effects including improved detection and repair of DNA damage, enhanced growth, and longevity. While the hormetic aspects of the adaptive response clearly increase fitness in the presence of environmental stresses, they must decrease fitness under normal environmental conditions because the responsible biological mechanisms are not maintained in an upregulated state but rather require some form of sensitizing exposure. It has been suggested that stimulation of the adaptive response could be metabolically costly however no direct measurement of the metabolic cost of radiation stimulated growth has been previously attempted.
This thesis assessed whether radiation-stimulated growth in the lake whitefish (Coregonus clupeaformis) is accompanied by a trade-off in metabolic efficiency, or by a sustained increase in energetic demands. Exposure to a fractionated regime of ionizing radiation from a 137Cs source was found to significantly stimulate growth in lake whitefish embryos compared to controls with a corresponding increase in yolk consumption. However, measurements of metabolic efficiency using a time series of unpreserved dry weights showed that the stimulated growth was unaccompanied by a reduction in metabolic efficiency.
An exponentially transformed mean temperature was used as a quantitative baseline to assess the vulnerability of developing whitefish embryos to phenological mismatch.  Hatch timing was found to deviate from baseline predictions under asymmetrically variable thermal regimes. The deviations were attributed to the embryos growing to a more advanced stage of development at low temperatures.  The term heterograde is proposed to describe the thermal dependency of hatching stage which may have evolved as a mechanism to synchronize the hatching of viable larvae to the increase of zooplankton density that accompanies spring break-up. A predictive model incorporating heterograde hatching yielded a significant improvement in predictive accuracy over previous models.
Energetic efficiency is of particular importance to the lake whitefish as it has one of the longest natural incubation periods of any freshwater fish, at some of the lowest incubation temperatures, and with eggs only 10% the size of most non-coregonine salmonids. The evolution of mechanisms to synchronize hatching to the break-up of winter ice cover highlights the vulnerability of the lake whitefish to phenological mismatch whether through accelerated development that causes embryos to hatch asynchronously with the break-up of winter ice cover, or through a sustained increase in energetic demands that increases their vulnerability to starvation.  The absence of any measurable trade-off in metabolic efficiency points to the latter as a plausible general cost of hormesis.

abstract: Dissertation

abstract: Doctor of Philosophy (PhD)


contributor:
Garside, B.K.
Engineering Physics

abstract: Title: Gain Saturation and Pulse Solutions for a CO2-HE T.E.A. Laser, Author: Terence Tricker, Location Thode

abstract: The saturation behaviour of various gain models for the CO2-HE T.E.A. laser was investigated. The corresponding laser pulse shapes for an oscillating cavity were generated by computer and compared to experimentally observed output pulses. Good agreement is obtained for low gain using a simple two-level model but at high gain, vibrational coupling between levels must be included.

abstract: Thesis

abstract: Master of Engineering (ME)


contributor:
McCaughey, J.H.
Geography

abstract: Title: An Evaluation of the Thornthwaite-Holzman Equation for Evapotranspiration, Author: Neil B.A. Trivett, Location: Thode

abstract:
Evapotranspiration involves a complex set of processes
which relate to the loss of water to the atmosphere. It involves
the uptake of water by the root system of plants, its movement through
the plant, and its diffusion through the stomata into the atmosphere.
The term evapotranspiration (Et) includes evaporation from the soil
and transpiration from vegetation. Two of the basic reasons for studying evapotranspiration are as follows: 1) Since it is the reverse process of precipitation, it has major consequences in agriculture through its control on plant growth. 2) It is one of the important energy fluxes from the earth's surface and is an integral part of the energy balance.

abstract: Thesis

abstract: Bachelor of Arts (BA)


contributor:
Harriss, R.C.
Kramer, J.R.
Geology

abstract: Title: Geochemical Investigations of Lacustrine Ferromanganese Concretions, Author: Arthur G. Troup, Location: Thode

abstract: Observations on the geological environment of formation and data concerning the mineralogy, petrography and chemistry of lacustrine ferromanganese concretions are presented. Implications of these data with respect to concretion formation are discussed, and a model for concretion genesis is suggested.

abstract: Thesis

abstract: Master of Science (MS)


title: Water Storage Dynamics in Peat-Filled Depressions of the Canadian Shield Rock Barrens: Implications for Primary Peat Formation

contributor:
Waddington, James Michael
Geography and Earth Sciences

subject:
Canadian Shield
peatlands
rock barren
peat
ecohydrology
moss stress
water table
Sphagnum
vernal pool
bog

abstract:
Northern peatlands have acted as persistent sinks of CO2 throughout the Holocene largely owing to their ability to maintain shallow water table depths that limit decomposition rates and supports the growth of keystone vegetation including Sphagnum mosses. There is concern, however, that the future success and ecosystem function of these northern peat deposits may be at risk to climate change, where temperatures and evaporation rates are predicted to increase substantially in the next century. While numerous studies have examined the hydrology and carbon dynamics in large expansive peatland systems where a water table (WT) is ever-present, relatively little research has been done on small scale peat-accumulating systems where their vulnerability remains unknown. One region where a broad spectrum in the scale of peat accumulation is present is in the bedrock depressions of Canadian Shield rock barrens, which are of special importance as many peat deposits here provide habitat to species at risk including the Blanding’s Turtle and the Massassauga Rattlesnake. This study examines the controls that govern water storage dynamics and moss water availability in 18 different peat-accumulating depressions that vary in size, catchment area, and sediment composition.
	The magnitude of WT variability was often several times greater in shallower bedrock depressions (<50 cm deep) as compared to deeper ‘bogs’ (>60 cm deep). The magnitude of depression WT variability appeared to be closely linked to the WT depth (WTD), the relative proportions of different sediment types within the depression, and the depth dependant specific yield (Sy) of each sediment type. Sites which contained large fractions of Polytrichum moss or mineral soil – which were more common in shallow depressions ¬¬– had the greatest WT variability due to the lower porosity and Sy of this sediment as compared to Sphagnum peat. Sphagnum dominated ‘vernal pools’ (30-50 cm deep) had a WT variability two to three times greater than Sphagnum dominated bogs at WTDs > 20-25 cm, which may be related to exceptionally high ash concentrations near the base of vernal pools which reduced peat porosity and Sy as compared to more organic-rich peat. As compared to bogs, pits (<15 cm deep) and vernal pools had greater rates of WT decline during drying intervals, deeper average WTDs when a WT was present, and extended periods of WT absence during the summer months. As such, moss growing in pits and vernal pools generally had lower near-surface water availability as compared to bogs, though the importance of depression depth in determining the timing of moss stress is also dependant on the hydrophysical properties (Kunsat and moisture retention) of the moss species in question. WT dynamics and moss water availability were generally weakly correlated to depression catchment size, although during wetter periods of the year the rate of WT recession was moderated in pits and vernal pools which had an upslope depression that could provide sustained water inputs for multiple days after rainfall. The results of this study suggest that depression depth may be a first order control in determining peatland vulnerability to future regime shifts induced by external forcings or disturbances. Furthermore, this study suggests that systematic differences may exist between the hydrophysical properties of peat in shallow vs. large bedrock depressions, potentially resulting from contrasts in fire frequency/severity, and/or the degree of humification/compression among geological settings.

abstract: Thesis

abstract: Master of Science (MSc)

abstract:
Canada is home to one of the largest reservoirs of organic carbon stored on land in the world, in unique ecosystems called peatlands. Peatlands are formed in wetland environments where a thick layer of organic matter has accumulated over time due to the average rate of vegetation growth on the surface of peatlands exceeding the rate of decomposition of the underlying organic matter. This net accumulation of organic matter over time has caused peatlands to act as a long term sink of carbon dioxide, which is a greenhouse gas that is a primary driver of global warming. The ability of peatlands to have slow decomposition rates and support the growth of key peatland vegetation, most notably various species of ‘peat moss’, is highly dependent upon their ability to keep their water table (i.e. the surface below which pore spaces in the organic matter are saturated with water) close to their growing surface. There is concern, however, that a warmer and dryer climate in the future could cause deeper water table positions in peatlands, thereby increasing decomposition rates, decreasing the growth rate of peat moss, and potentially turning peatlands into a net source of carbon dioxide.
	Most peatland studies to date, however, have focused on water storage/movement and carbon exchange in large, deep peatland systems, whereas relatively little research has been conducted on smaller peatlands. As such, the vulnerability of these smaller peatlands to future climate change remains uncertain. One region where peatlands exist over a wide range of different sizes and landscape positions is in bedrock depressions of the Canadian Shield, which are of special interest as they also provide habitat for species at risk including the Blanding’s Turtle and the Massassauga Rattlesnake. This study looked at how the water table positions and water availability to different species of peat moss compared over the growing season between 18 peatlands of different sizes and landscape position (i.e. peatlands with a relatively ‘small’ and ‘large’ area upslope of them).
	This study finds that deeper peatlands (with organic matter layers > 60 cm deep) usually had a shallower water table over the summer months than shallower peatlands (< 50 cm deep), primarily due to differences in the properties of the organic matter underlying their growing surfaces. Furthermore, each of the 12 studied peatlands < 50 cm deep lost their water table for a considerable amount of time during the summer (when their water table position dropped below the underlying bedrock of the depression), whereas each of the six peatlands > 60 cm deep had a water table present for the entire growing season. Surprisingly, a peatland’s position on the landscape seemed to have a relatively minor effect on determining the depth/presence of its water table. As deeper peatlands usually had a water table that was closer to the growing surface and was always present, more moisture was available to the peat moss growing at their surface than for peat moss in shallower depressions, though this moisture availability also depended upon the growth form of the different species of peat moss (some species of peat moss were better at accessing subsurface water than others). Through its impact on water table positions and moisture availability for peat moss, peatland depth is likely a primary control governing peatland vulnerability climate change, with shallower peatlands being more vulnerable to warmer and dryer conditions in the future.


title: WHEN GLOBAL IDEAS COLLIDE WITH DOMESTIC INTERESTS: THE POLITICS OF SECONDARY EDUCATION GOVERNANCE IN ARGENTINA, CHILE AND COLOMBIA

contributor:
Dion, Michelle
Political Science

subject:
education policy
education governance
education reform
education privatization
social policy
globalization
curriculum policy
standardized exams

abstract: Latin American countries have shifted from a model of education governance based on hierarchical rules and centralized authority to a results-driven model with shared responsibility among state and non-state actors. Yet, adopted governance models show remarkable cross-national variation. This dissertation aims at explaining this variation amid convergence through the qualitative comparative analysis of education governance in Chile, Argentina, and Colombia during three distinct periods of development, namely centralized education planning from the standpoint of manpower needs (1960s-1970s), market-oriented governance mechanisms (1980s-1990s), and accountability-oriented education for all (2000s-2010s). This analysis demonstrates that while diffusion of widely recognized policy ideas about education governance produces convergence, political contestation of domestic organized actors produces variation that ranges from full adoption to outright rejection of foreign recommendations. My study qualifies insights from institutional and diffusion theories by specifying the conditions in which domestic actors are able to modify both, domestic institutions and powerful foreign ideas.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract: Education reforms in several Latin American countries follow a global trend characterized by at least three changes: 1) from selective student recruitment towards the universalization of secondary education and school choice for families; 2) from a centralized curriculum towards curricular autonomy; and 3) from student evaluation exclusively delegated to teachers towards national standardized tests. Yet, adopted governance models show remarkable cross-national variation. Chile has traditionally emulated global ideas and become a quasi-market of education. Argentina was more reluctant to global norms and made only moderate changes to the state-run governance model. Finally, Colombia left the education of the wealthy to the market, while centralized the authority over the education of the poor. Through a comparative historical analysis of these three countries, this study explains the way in which global ideas are domestically translated through the interaction between diffusion mechanisms, domestic policy legacies, and the ability of domestic actors to negotiate the implementation of foreign recommendations. The evidence provided by this dissertation suggests that the level of organization, the closeness to the decision-making process, and the impact of the power resources of supporters and opponents of global ideas define the extent to what these ideas are adopted. If global ideas favor the interests of powerful actors and opposition is weak the more likely result is the emulation of foreign recommendations. Yet, the more the opposition obtains resources to force powerful actors to bargain, the more the chances for global norms to be resisted or rejected. This analysis explains how the encounter between global norms and domestic institutions shapes processes of domestic institutional entrepreneurship and uncovers paths through which this entrepreneurship is more likely to produce emulation or rejection of global ideas. This dissertation qualifies insights of historical and sociological institutionalisms and contributes to the literature on education policy globalization.


contributor:
Shewchun, J.
Electrical Engineering

abstract: Title: Electrical Properties of Nitrogen and Oxygen Ion Implanted Silicon, Author: Vince P. Tovizi, Location: Thode

abstract:
The electrical properties of nitrogen and oxygen
ion implanted silicon samples have been investigated as
a function of various implantation and annealing conditions.

The temperature dependence of the electrical
characteristics of the implanted samples were analysed and
the results were compared with the ones obtained from
experiments performed on typical bulk silicon samples.
A unique computer controlled automatic system (J . Shewchun
et al.) was used for the low temperature conductivity
and Hall effect measurements. Donor behaviour of the
implanted layers was observed in both the nitrogen and
oxygen implantation cases. It has been established that
very low conversion efficiency can be achieved in the
nitrogen and oxygen implants. Less than 1% of the
implanted ions became active after a high temperature
(325°C) anneal. The activation energies of donor like
impurities were determined by analysing the carrier
concentration versus reciprocal temperature graphs. It
has been concluded that the form of the above graphs
can only be described by a partially compensated
semiconductor model which has more than one donor energy
level. A model containing two monovalent kinds of donors
with different energy levels and some assorted compensating
acceptors was used to fit the carrier concentration vs. (1/T)
curves. The activation energies of donor impurities were
determined to be ED1= 0.016 ± 0.001 (eV), ED2 = 0.034 ± 0.003
(eV) for the nitrogen implants and ED1 = 0.021 ± 0.001 (eV) 1
+ E = 0.031 - 0.001 (eV) for the oxygen implanted silicon. We found the above ionization energies consistent and independent
of the implantation and annealing conditions.

This study showed that the active impurity centers
in the implanted layers could be well controlled by the
implanted total dose, and were reproducible in the concentration
range which is generally used in device fabrications.

abstract: Thesis

abstract: Master of Engineering (ME)


title: Fantasy: The Literature of Repetition

title: Fantasy: The Literature of Repetition – An Examination of Lady Éowyn, Hermione Granger, and Keladry of Mindelan

contributor:
Grisé, Catherine Annette
English and Cultural Studies

subject:
fantasy literature
children's literature
young adult literature
feminist theory
J.R.R. Tolkien
Lord of the Rings
Lady Eowyn
J.K. Rowling
Harry Potter
Hermione Granger
Tamora Pierce
Protector of the Small
Keladry of Mindelan
subversion
legacy code
refactoring

abstract: This project explores the narrative arcs of strong female characters in Young Adult (YA) fantasy literature. Taking up Rosemary Jackson’s assertion that fantasy literature can ‘subvert patriarchal society,’ this thesis examines the fantasy ‘legacy code’ of strong and subversive female characters who settle into a stereotypical performance of gender after finding fulfillment in the heteronormative roles of lover, wife, and mother. This pattern is exemplified by Lady Éowyn of J.R.R. Tolkien’s The Two Towers (1954) and The Return of the King (1955), and reproduced by Hermione Granger of J.K. Rowling’s  Harry Potter series – consisting of Harry Potter and the Philosopher’s Stone (1997), Harry Potter and the Chamber of Secrets (1998), Harry Potter and the Prisoner of Azkaban (1999), Harry Potter and the Goblet of Fire (2000), Harry Potter and the Order of the Phoenix (2003), Harry Potter and the Half-Blood Prince (2005), and Harry Potter and the Deathly Hallows (2007). In contrast Keladry of Mindelan in Tamora Pierce’s Protector of the Small series – consisting of First Test (1999), Page (2000), Squire (2001), and Lady Knight (2002) – demonstrates the impact ‘refactoring’ fantasy ‘legacy code’ has on the narrative conclusions of female characters. Using Judith Butler’s theory on the performative nature of gender and building on Farah Mendlesohn’s computer programming analogy of ‘legacy code,’ this thesis illustrates the ways in which fantasy literature often fails to be the literature of subversion Jackson envisions, and demonstrates how refactoring aspects of a female character’s narrative exemplifies subversive narrative conclusions for young adult readers of fantasy literature.

abstract: Thesis

abstract: Master of Arts (MA)

abstract: This thesis examines the ways in which a heteronormative ‘legacy code’ – exemplified by Lady Éowyn in J.R.R. Tolkien’s Lord of the Rings – has been perpetuated in literature marketed towards young adult readers by Hermione Granger in J.K. Rowling’s Harry Potter series and ‘refactored’ by Keladry of Mindelan in Tamora Pierce’s Protector of the Small series. Starting with Rosemary Jackson’s analysis of fantasy literature as a genre with subversive potential and with Judith Butler’s assertion that gender is performative, this thesis analyses the narrative arcs of Éowyn, Hermione, and Kel and demonstrates how the continual representation of strong female characters finding fulfillment in the roles of lover, wife, and mother is limiting, and highlights the subversive potential in ‘refactoring’ heteronormative ‘legacy code.’


title: Linking Super Earth Composition to Planet Formation History

contributor:
Pudritz, Ralph
Physics and Astronomy

subject:
planet formation
super Earths
protoplanetary disks
planet composition

abstract: Super Earths are a class of exoplanets with masses between 1-10 M⊕. Comprising nearly 70 % of the discovered planet population, they are largest class of exoplanets known. Super Earths exhibit an interesting variety of compositions, as their densities imply that they range from dense, rocky planets to those with substantial amounts of water. This thesis aims to understand why super Earths form so frequently, and to connect the final compositions of super Earths to the regions where they form in protoplanetary disks. To do this, we combine a model that calculates the physical and chemical conditions within a protoplanetary disk with a core accretion model of planet formation. A key feature of our planet formation model is planet traps that act as barriers to rapid type-I migration. The traps we include in our model are the dead zone, which can be caused by cosmic ray or X-ray ionization, the ice line, and the heat transition. In disks with lifetimes >􏰐 4 Myr we find that planet formation in all traps results in Jovian planets. Typically, the X-ray dead zone and heat transition traps produce hot Jupiters orbiting near 0.05 AU while the cosmic ray dead zone and ice line traps produce Jupiters near 1 AU. Super Earths are found to form in disks with short lifetimes 􏰑< 2 Myr that photoevaporate prior to planets undergoing runaway gas accretion. Additionally, we find that super Earth formation takes place in low-mass disks (<􏰑 0.05 M⊙), where planet formation timescales exceed disk lifetimes inferred through observations. The location of various traps throughout the disk play a key role in allowing super Earths to achieve a range of compositions. Super Earths forming in the ice line or heat transition accrete solids from cold regions of the disk, resulting in planets with large ice contents (up to 50 % by mass). Conversely, super Earths formed in the dead zone trap accrete solids from warm regions of the disk and are therefore composed of mostly rocky materials (less than 5 % ice by mass).

abstract: Thesis

abstract: Master of Science (MSc)


title: Polyamide Carbon Fibre Filled Composite Ageing Characterization in Conventional Automotive Fluids

contributor:
Thompson, Michael
Chemical Engineering

subject: polyamide, carbon fibre, composite, ageing, characterization, automotive, chemical resistance, mechanical degradation, plasticization, capillary action, diffusion

abstract:
The use of carbon fibre-reinforced plastic technology is steadily gaining traction in the modern automotive industry as a lightweight alternative to conventional materials. The versatile chemical resistance of polyamide resins combined with the high strength properties of carbon fibre filler content aims to meet this growing need in the industry. By employing a number of accelerated and amplified ageing techniques, this work hopes to assess the resilience of carbon fibre-reinforced polyamide composites in a variety of foreseeable chemical, temperature, moisture, and stress environments.
The resins included in this characterization study include polyamide-6 (PA6) and polyamide-6,6 (PA6/6). The carbon fibre-reinforced composite specimens are subject to long term immersion in commercial automotive fluids at room and elevated temperatures. Results show that the mechanical properties of both polyamide resins are sensitive to windshield washer fluid exposure, regardless of temperature. The significant drop in glass transition temperature and greater elongation at break confirmed a plasticization effect. The Young’s modulus and tensile strength experienced a loss of approximately 40% at saturation.
Elevated temperatures resulted in increased fluid sorption rates of antifreeze and E-20 gasoline into the PA6 composite specimens. Likewise, a corresponding drop in PA6 composite mechanical properties was noted for the antifreeze and E-20 gasoline at elevated temperatures. The mechanical properties of the PA6/6 composite were largely retained in all tested automotive fluids, except windshield washer fluid, at elevated temperatures. The effect of absorbed fluid on mechanical properties tended to increase with higher fibre loadings for the PA6/6 composite and lower fibre loadings for the PA6 composite.
Finally, a single parameter acoustic emission testing technique was employed to assess internal damage of stressed PA6 composite specimens exposed to different temperature and humidity levels. However, there was no discernible correlation between environmental stress conditions and internal damage for short term exposure times.

abstract: Thesis

abstract: Master of Applied Science (MASc)

abstract: The use of carbon fibre-reinforced plastic technology is steadily gaining traction in the modern automotive industry as a lightweight alternative to conventional materials. The versatile chemical resistance of polyamide resins combined with the high strength properties of carbon fibre filler content aims to meet this growing need in the industry. By employing a number of accelerated and amplified ageing techniques, this work assessed the resilience of carbon fibre-reinforced polyamide composites in a variety of foreseeable chemical, temperature, moisture, and stress environments. The composite only showed significant sensitivity to windshield wiper fluid in the tests.


title: Bicycling in Hamilton: Challenges Associated with Bicycling and Cyclists' Subjective Identities

contributor:
Gillett, James
Health and Aging

subject: bicycling, cyclists, barriers, cyclist identity, Hamilton

abstract: In order to adequately design for and promote safe and regular use of the bicycle as a form of active transportation, researchers and policy-makers alike would benefit from the input of practiced bicyclists. These lay experts possess unique experiential knowledge of local routes, gaps in the network and the degree of comfort afforded by different types of infrastructure. Furthermore, these individuals are adept at commenting on subjectively valuable aspects of bicycling, which may assist in informing promotion and marketing of this activity. This research draws on the knowledge of lay experts who regularly bicycle in Hamilton, Ontario. The objectives of this research were to identify and understand the challenges associated with bicycling in Hamilton, and to explore the subjective identities of Hamilton’s cyclists. A thematic analysis of 10 semi-structured interviews was conducted and the following themes were identified and explored: an array of physical, structural and social deterrents to bicycling exist in Hamilton; and the identities of Hamilton’s cyclists are complex, locally rooted and multidimensional in nature. Using a critical lens, with the help of the Social Ecological Model of Health and Identity Theory, this study draws the following conclusions: cyclists are well-equipped to critically evaluate the urban spaces through which they travel; cyclists may play an important role in encouraging non-users to take up bicycling; and cyclists and auto drivers may benefit from collaborating over mutually beneficial goals. Furthermore, while many individuals who ride bicycles do identify themselves as “cyclists” this terminology can be contentious and the identity is heavily rooted in cyclists’ local context. Although this identity is primarily experienced individually, a sense of community does exist; and the identity often spans beyond the simple action of riding a bicycle.

abstract: Thesis

abstract: Master of Arts (MA)

abstract: In order to adequately design for and promote safe and regular use of the bicycle as a form of active transportation, researchers and policy-makers alike would benefit from the input of practiced bicyclists. These lay experts possess unique experiential knowledge of local routes, gaps in the network and the degree of comfort afforded by different types of infrastructure. Furthermore, these individuals are adept at commenting on subjectively valuable aspects of bicycling, which may assist in informing promotion and marketing of this activity. This research draws on the knowledge of lay experts who regularly bicycle in Hamilton, Ontario. The objectives of this research were to identify and understand the challenges associated with bicycling in Hamilton, and to explore the subjective identities of Hamilton’s cyclists. An analysis of 10 semi-structured interviews was conducted and the following themes were identified and explored: an array of physical, structural and social deterrents to bicycling exist in Hamilton; and the identities of Hamilton’s cyclists are complex, locally rooted and multidimensional in nature. This research emphasizes the contributions bicyclists have to offer social science literature and highlights the need for continual input and engagement with everyday bicycle users. This ongoing communication is important to adequately support and encourage regular and new bicycle users in practicing this healthy and sustainable means of transportation.


title: THE INTERACTIVE EFFECTS OF GREEN TEA EXTRACT SUPPLEMENTATION AND EXERCISE ON METABOLISM AND GLYCEMIC CONTROL IN HUMANS

contributor:
Gibala, Martin
Kinesiology

subject: Green Tea Extract, Exercise, Metabolism, Glycemic Control

abstract: Green tea contains high concentrations of polyphenolic compounds known as catechins. Studies in animal models suggest several potential mechanisms for specific metabolic effects at rest and during exercise, including improved glycemic control,  altered activity of several glucose transporter proteins and improved endurance capacity. In humans, green tea extract (GTE) supplementation has been associated with improved glycemic control under resting conditions and increased fat oxidation during exercise. This dissertation examined the potential interactive effects of GTE supplementation and exercise on metabolism in humans with a focus on glycemic control. In Study 1, we demonstrated that GTE increased lipolysis and reduced heart rate during steady-state exercise in recreationally active men. Although substrate oxidation was not affected, GTE appeared to lower postprandial glucose under resting conditions. We hypothesized that the effects of GTE on exercise metabolism and glycemic control would be more apparent in humans with reduced exercise tolerance and impaired glucose tolerance. Thus, in Study 2, we examined the effects of GTE in sedentary overweight men. There were no differences in any metabolic or physiological responses during exercise; however, following exercise, GTE supplementation reduced [glucose] and insulinemia in response to an oral glucose load. Based on the findings of Study 2, the aim of Study 3 was to elucidate potential mechanisms for the alterations in glycemic response. Through the use of a dual-glucose tracer method, we demonstrated that GTE did not affect the rate of appearance of glucose in plasma in sedentary men; however, GTE supplementation allowed for the same glucose clearance rate despite a reduced insulinemia. We also observed lower carbohydrate oxidation during exercise with GTE. These findings suggest that GTE has an insulin-sensitizing effect during recovery from exercise, possibly due to enhanced glucose transporter activity; however, this hypothesis warrants further investigation in humans.

abstract: Dissertation

abstract: Doctor of Science  (PhD)

abstract: Tea is one of the most popular beverages in the world. Compared to other teas, green tea has a greater abundance of catechins, compounds that have been associated with health benefits particularly related to the metabolism of sugars and fats. This unique property of green tea could partly explain its longstanding medicinal role in some Asian cultures. Extensive research on green tea has increased its popularity over the past three decades. Studies involving both humans and other animals have shown improvements in weight control and glycemic control. In response to these findings green tea is often touted as having “anti-obesity” and anti-diabetic” properties. This dissertation examined the interaction between green tea extract supplementation and exercise on metabolism with a particular focus on blood sugar control. We observed that supplementation with green tea extract improved the response to sugar ingested after exercise. This finding has important implications for improving the control of ingested sugar in humans.


title: Fast and Inexpensive Detection of Bacterial Viability and Drug Susceptibility Through Metabolic Monitoring

contributor:
Selvaganapathy, Ponnambalam Ravi
Biomedical Engineering

subject:
Point of care technology (POC)
diagnostics
infectious diseases
nanotechnology

abstract: Conventional methods for the detection of bacterial infection such as DNA or immunoassays are either expensive, time consuming, or not definitive; thus may not provide all the information sought by the medical professionals. In particular, it is difficult to obtain information about viability or drug effectiveness, which are crucial to formulate a treatment.  Bacterial culture test is the “gold standard” because it is inexpensive and does not require extensive sample preparation, and most importantly, provides all the necessary information sought by healthcare professionals, such as bacterial presence, viability and drug effectiveness. These conventional culture methods, however, have a long turnaround time: anywhere between 1 day to 4 weeks.  This thesis proposes to solve this problem by monitoring the growth of bacteria in thousands of nanowells simultaneously to identify its presence in the sample and its viability, faster. The segmentation of a sample with low bacterial concentration into thousands of nanoliter wells digitizes the samples and increases the effective concentration in those wells that contain bacteria. The user may then monitor the metabolism of the aerobic bacteria by using an oxygen sensitive fluorophore, ruthenium tris (2,2’-diprydl) dichloride hexahydrate (Ru(Bpy)3) by monitoring the dissolved oxygen concentration in the nanowells. Using E.Coli K12, it is demonstrated that the detection time of E.coli can be as fast as 35-60 minutes with sample concentrations varying from 104(62 minutes for detection), 106 (42 minutes) and 108 cells/mL (38 minutes).  More importantly, throughout the thesis it is also demonstrated that reducing the well size can reduce the time of detection. Finally, this thesis will discuss how the drug effectiveness information can be obtained in this format by loading the wells with the drug and monitoring the metabolism of the bacteria. The method that is developed in this thesis is low cost, simple, requires minimal sample preparation and can potentially be used with a wide variety of samples in resource poor setting to detect bacterial infections such as Tuberculosis.

abstract: Thesis

abstract: Master of Science (MSc)


title: Pharmaceuticals, wastewater effluent, and agonistic behaviours in a wild, invasive fish (Neogobius melanostomus)

contributor:
Balshine, Sigal
Psychology

abstract: Anthropogenic contaminants in aquatic ecosystems are of widespread concern for ecosystem managers, scientists, and the organisms living in impacted habitats. Certain contaminants, like human pharmaceuticals and personal care products that are found in wastewater effluents, have been shown to have subtle but important effects on the physiology and behaviour of exposed organisms. Ecotoxicologists are therefore increasingly using behavioural endpoints to evaluate the impacts of treated wastewater effluents and pharmaceuticals on aquatic animals. However, few studies have evaluated whether behaviour is altered following exposure to wastewater effluents that wild fish are exposed to in their environments. Moreover, few studies have comprehensively evaluated the impacts of a given pharmaceutical or effluent exposure by testing behaviour over multiple behavioural contexts. In my thesis, I examined the effects of a pharmaceutical commonly reported in the environment, the antidepressant fluoxetine, as well as a complex mixture, wastewater effluent, on the behaviour of an invasive fish species, the round goby (Neogobius melanostomus). I focused on aggressive and social behaviours that are both critical for this species’ survival and reproduction, and also explored these behaviours in the absence of any exposure. I showed that round goby are attracted to conspecifics, but do not preferentially associate with larger versus smaller groups of conspecifics (Chapter 2). Most of the “social” interactions were aggressive in nature, and I further explored aggression, showing that round goby were more aggressive over high quality (enclosed) shelters compared to low quality (open) shelters (Chapter 3). When round goby were exposed to the antidepressant fluoxetine, aggression declined rapidly and in multiple aggressive contexts, but only at concentrations higher than those reported in surface waters (Chapter 4). Intriguingly, fish exposed to wastewater effluent in the laboratory also showed reduced aggression towards a mirror (Chapter 5), but fish exposed to wastewater effluent in the wild showed little evidence of behavioural or physiological change following exposure (Chapter 6). Across experiments, I evaluated the relevance of mirror aggression assays as a surrogate for dyadic aggressive contests, and concluded that mirror aggression assays poorly predicted the outcome of more ecologically relevant paired interactions. Altogether, my findings suggest that adult round goby may be resilient to the exposure conditions I tested. My work further develops behaviour as a tool for investigating the impacts on environmental contaminants on aquatic organisms and broadens the species range used for such studies.

abstract: Dissertation

abstract: Doctor of Philosophy (PhD)


title: Mass-Yield Variations in the Thermal and Epi-Thermal Fissions of 239Pu

contributor:
Fritze, K.
Chemistry

subject: mass-yield, thermal, fissions, neutron

abstract:
 Some cumulative mass-yield ratios for thermal to epi-thermal neutron fissions of 239Pu have been measured by nondestructive Ge(Li) spectrometric and radiochemical methods. The mass-yield ratios of 85mKr, 91Sr- 91mY, 92Sr, 97Nb-97Zr, 99mTc, 103Ru, 105Ru, 131I, 132Te-132I, 133I, 135I-135Xe, 140Ba-140La, 143Ce and 147Nd for both thermal to epi-Cd and thermal to epi-Sm fissions did not show any significant fluctuations. The yields of 72Zn and 166Dy-166Ho in epi-Sm fission were found to be 30±2% lower than in the fission caused by thermal neutrons. Similarly the yields of 115Cd and 112Pd were found to be lower by 46±2% and 24±3% respectively. The 77 mass chain, measured as both 77Ge and 77As, showed only a very slight, if any, decrease for epi-Cd and epi-Sm fissions as compared with
thermal neutron fissions.

 The results are consistent with the two-mode-of-fission
hypothesis. An attempt has also been made to correlate the observations with the effect of the spin states of the fissioning nucleus at the saddle point.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Design, Simulation and Optimization of a Biomass-Natural-gas-and-Nuclear to Liquid Fuels and Power Process

contributor:
Adams II, Thomas A
Chemical Engineering

abstract: The unsustainable use of natural resources to power our world has depleted energy stores globally, and evokes a need to explore other environmentally-friendly options. This thesis presents a novel polygeneration design of a woody biomass-natural gas-nuclear energy-to-liquid-fuels and power (BGNTL) process, and assesses its economic and environmental feasibility in the context of Ontario, Canada. To assess the efficacy of nuclear energy in this system, a BGTL (biomass-natural gas to liquid fuels and power) system was compared with the BGNTL system. In both processes, carbon capture sequestration (CCS) was also incorporated. Many different cases of the plant were analyzed, including combinations of steam radiant syngas cooling (RSC), steam methane reforming integrated with the RSC (IR), and the addition or removal of CCS. It was found that for CCS cases, there was a positive relationship between the increase of CO2 tax and profitability. The optimal design produces only dimethyl ether (DME), uses no nuclear energy, and sends all of the off-gas to the solid-oxide-fuel-cell (SOFC). In the optimal case, the RSC making steam was slightly better than the IR by about 0.6% net-present-value (NPV), and a switch from non-CCS to CCS resulted in a 1% increase in NPV. Minimal DME prices to keep optimal cases profitable were around $798 - $807 for CCS and non-CCS cases, respectively. Overall, it was found that the life cycle CO2 impact in the optimal case of DME production was much less environmentally damaging compared with traditional diesel production. Specifically, in the CCS case, DME had approximately 100,000 less grams of CO2e / GJ of energy than a traditional diesel production. In the non-CCS case, the impact was approximately 50,000 less grams of CO2e / GJ of energy.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: CHARACTERIZATION OF MUSASHI-2 IN HEMATOPOIETIC STEM CELLS

title: CHARACTERIZATION OF MUSASHI-2 IN HEMATOPOIETIC STEM CELL SELF-RENEWAL

contributor:
Hope, Kristin
Biochemistry and Biomedical Sciences

abstract: The life-long production of blood cells is enabled by hematopoietic stem and progenitor cells (HSPC) residing in the bone marrow. An understanding of the genes that control how HSPCs work to sustain the continued production of blood cells will enable new therapies to expand them for life-saving transplantation therapies. The Musashi gene family of RNA binding proteins (RBP) has been implicated to control stem cell function in a variety of adult tissues (e.g. brain and gut) and emerging evidence in mice shows Musashi-2 (Msi2) to be an essential positive regulator of HSPCs, yet no work to date has tested its function in the human system. Here I show that MSI2 is highly expressed in cord blood (CB) HSPCs and that knockdown of MSI2 impairs HSC repopulation in xenotransplanted mice. Conversely, MSI2 overexpression yields multiple pro-self-renewal phenotypes, including 17-fold expansion of short-term repopulating cells as readout at an early post-transplant time point, and upon ex vivo culture, a net 23-fold expansion of long-term hematopoietic stem cells (LT-HSC). I further found that MSI2 overexpression post-transcriptionally downregulates the aryl hydrocarbon signalling pathway, which has been shown when repressed by a small molecule antagonist, greatly supports the expansion of human HSCs. Altogether, this work highlights RBPs and post-transcriptional control to have an integral role in controlling human HSC self-renewal. For the second part of my thesis, I re-explored the role of Msi2 in the mouse hematopoietic system using a newly generated tamoxifen inducible Msi2 knockout mouse. Using this approach I found Msi2 deletion significantly restricted repopulation in competitively transplanted mice and that this effect was due to depletion of early types of multipotent progenitors and not due to a loss of LT-HSCs. As there is currently a discrepancy as to which cells Msi2 precisely regulates in the mouse hematopoietic system, my work provides support that MPPs are the most affected cell type. Altogether, my thesis provides novel insight in to the role and mechanism of action of Musashi-2 in both human and mouse HSPCs.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Analysis of Flow Reversal under Two-Phase Natural Circulation in CANDU9 during Small Loss of Coolant Accident with Loss of Class IV Power

contributor:
Luxat, John
Engineering Physics

subject:
flow reversal
natural circulation

abstract:
A thermal hydraulic analysis has been conducted to investigate the conditions leading
to the channel flow reversal and the subsequent effects that may have on the Primary
Heat Transfer System(PHTS) thermohydraulic parameters during the natural circulation
under the specific accident scenarios for a generic CANDU 900 MW plant model
similar to Darlington NGS. The assumed initiating events are the combination of a
small Loss Of Coolant Accident (LOCA) with a loss of Class IV power, as well as the
unavailability of Emergency Coolant Injection (ECI) system. No makeup inventory
is taken into account in this study, and there is no fuel sheath temperature excursion
or fuel centerline melting, i.e., the integrity of fuel is always maintained.
A one-dimensional quasi-steady state Homogeneous Equilibrium Model(HEM) has
been constructed for the study. A specific node-link structure is adopted to represent
the primary heat transfer loop: The whole loop and different components in HTS are
represented by a series of nodes that have quasi-static thermal hydraulic characteristics
such as pressure and enthalpy, etc. Dynamic characteristics are delivered by the
links between nodes, e.g., flow rate and pressure drop. The channel powers (decay
heat), the secondary side pressure and the pressure at Reactor Inlet Header(RIH) are
chosen as boundary conditions to describe the assumed initiating incidents for the
iii
model.
With ongoing loss of inventory and system depressurization, vapor lock occurs
in Steam Generator(SG), and it increases the pressure drop from Reactor Outlet
Header(ROH) to RIH across SG and forms an increasingly negative RIH-to-ROH
pressure differential. Flow reversal occurs in the channel due to the counter force balance
between negative RIH-to-ROH pressure difference and the driving force derived
from the density difference between the hot and cold legs. It is found that channels
in row A have the highest reversal preference, then followed by the channels in row B,
and in that order subsequently. Row A reverses when inventory decreases to about
79.5% of initial value, with following boundary conditions: decay heat is 1.5% of Full
Power(FP) and secondary side pressure is 5.070 MPa. In addition, it is found that the
decrease in channel power accelerates the depressurization process and brings forward
the occurrence of flow reversal in fuel channels.

abstract: Thesis

abstract: Master of Applied Science (MASc)


contributor:
Hoffman, T.W.
Chemical Engineering

abstract: Title: A Flow of Reversal Study in Opposing Free and Forced Convective Flow in a Vertical Tube, Author: Brian K. Tsang, Location: Thode

abstract: Flov reversal conditions in the turbulent opposing convection regime were investigated in the cooling of upflow water and the data correlated by the equation: Gr/(Re^2.58)=0.053/Pr for 6 ≤ (L/d) ≤ 18. The Metais-Eckert plot, which depicts the region of natural/forced convection interaction effects on the heat transfer coefficient, was found to be unsuitable for correlating the conditions for which flow reversal occurs because of the improper inclusion. of the parameter (d/L).

abstract: Thesis

abstract: Master of Engineering (ME)


title: A Diffuse Reflectance Spectroscopy Instrument for use in the Optical Biopsy of Brain Tumour Margins

contributor: Radiation Sciences (Medical Physics/Radiation Biology)

subject:
Optical Biopsy
Diffuse Reflectance
Tissue Optics

abstract:
Optical biopsy is a medical technique that uses light to perform non-invasive analysis of tissue in-situ. This technology has many applications in the medical profession, opening up exciting new possibilities for surgical guidance and diagnosis of malignancies and other conditions. Optical biopsy allows a medical professional to perform near instantaneous, real time analysis of tissue composition without the need to physically remove tissue from the body, as required in traditional biopsy.
A technique frequently used for this purpose is diffuse reflectance spectroscopy (DRS): collection and analysis of the spectrum of light reflected from a material. Another technique frequently used for optical biopsy is laser induced fluorescence spectroscopy (LIFS): analysis of the fluorescence spectrum returned by a material when illuminated at a specific wavelength.
This thesis discusses the design and construction of a spatially resolved DRS system intended for use in a dual modality DRS and time resolved LIFS optical biopsy instrument for clinical analysis of brain tissue. This instrument is specifically intended for use in the surgical removal of malignant gliomas: infiltrating tumours associated with a poor patient prognosis.
Theoretical simulation based studies were used to optimize the design of a compact, dual modality fibre optic probe for use in the system and  a novel algorithm was developed to allow recovery of the optical properties of tissue from reflectance spectra obtained with this probe. This probe was manufactured and a corresponding spectrometer based system was created for the acquisition of diffuse reflectance spectra. Components were designed to allow sterilization and thus clinical use in an operating room environment. A laboratory trial of this system demonstrated its range and ability to recover the optical properties of lipid emulsion optical phantoms.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


contributor:
Kirkaldy, J.S.
Metallurgy and Materials Science

abstract: Title: The Growth of Intermetallic Phases on Iron Galvanized in an Aluminum-Bearing Zinc Bath at 450°C, Author: Miroslav Urednicek, Location: Thode

abstract:
This thesis is concerned with determination of the nature and
growth characteristics of the intermediate phases formed on iron galvanized in Al-bearing Zn at 450°C, Long time equilibrium experiments have been carried out to explain the nature of intermetallic phases and their equilibria in the system Fe-Zn-AI at 450°C using electron probe microanalysis and metallographic techniques.

The growth characteristics of intermediate phases formed on iron galvanized in AL-bearing Zn at 450°C have been investigated by metallography and low angle X-ray diffraction. It has been confirmed that the inhibition layer is composed of Zn-bearing Fe2Al5 and FeAl5. While the FeAl2 phase was erratically detected, we did not detect the presence of FeAl. X-ray
diffraction data for FeAl2, so far missing from the ASTM X-Ray Data File,
have been recorded. A correlation of our results and that of other workers
with our newly investigated and proposed ternary isotherm at 450°C using an analysis via diffusion paths on the isotherm has produced a convincing
rationalization of the inhibiting effect and the catastrophic interface
instabilities which develop preferentially in stagnant baths after long
times and with the higher bath Fe contents.

abstract: Thesis

abstract: Master of Engineering (ME)


title: The Magicians and North American Education

title: Fantasy Fiction as a Tool for Pedagogical Change

contributor:
Grisé, Catherine A.
English and Cultural Studies

subject:
fantasy
education
Lev Grossman
The Magicians
literary analysis
pedagogy

abstract: Taking up Henry Giroux’s call for an “enobling [sic], imaginative vision” and a “language of possibility” with which to generate hope and a plan for improving education in North America, this thesis presents Lev Grossman’s fantasy series – the Magicians trilogy, consisting of The Magicians (2009), The Magician King (2011), and The Magician’s Land (2014) – as providing this ‘vision’ and ‘language’ through its representations of education. Using a close reading practice alongside the method of thematic criticism outlined by Farah Mendlesohn, key passages in the series are analysed to explicate an “imaginative vision” of an ideal, alternative education and present this vision – alongside a plan for achieving it – to educators. I argue that the series can be a pedagogical tool to serve educators in recognising the issues inherent in the current North American education system and the need for reform, in facilitating and motivating the implementation of an ideal alternative in their classrooms – an autonomous education practice based on the theories of Paulo Freire and John Holt – and in aiding with explicit instruction on the concept of agency to foster student success within the new classroom practice. Through a process of literary analysis, the Magicians series is presented to educators to help them understand and implement theories such as liberating and dominating praxis, banking education, and autonomous education. Rather than waiting for institutional-level or school-level reforms, this thesis helps educators reform their classrooms immediately, improving education outcomes for students and demonstrating the possibilities and benefits of adopting an autonomous education practice. In addition to presenting the Magicians series as a pedagogical tool to address the issues in education, this thesis also posits fantasy fiction as a valuable body of literature for seeking solutions to real world problems by demonstrating the applicability of fantastic representations of education to solving real world issues.

abstract: Thesis

abstract: Master of Arts (MA)

abstract: This thesis presents Lev Grossman’s Magicians trilogy as a tool for teachers, scholars, and students to use in addressing the problems in education in North America today. Starting with Henry Giroux’s research and writings on the problems with North American education, the Magicians is presented as the “imaginative vision” Giroux says must be located in order to inspire hope and present a plan for addressing these issues and modifying education to improve the outcomes for every student. Combining the theories of educators Paulo Freire and John Holt with the practice of literary analysis, this thesis examines the Magicians and argues that a critical reading of this fantasy series can serve educators by identifying the current problems and the need for reform, by introducing a new autonomous education practice that can be used in individual classrooms, and by supporting students in this new system through teaching the concept of agency directly.


title: The Good, The Bad, and the Indifferent: Lodging Homes in Hamilton, Ontario

contributor:
Zhou, Y. Rachel
Social Work

subject:
lodging home
poverty
mental illness
social worker

abstract: This research aims to explore the ways in which community-based mental health social workers assess the qualities of residential care facilities in order to make recommendations to their service users. The daily challenges of serving a marginalized population within the context of structural inequalities and neoliberalist service provision describe some of the contradictions that shape the work experiences of social workers. This research seeks to contribute to and further our understanding of critical social work practice, social justice, and structural oppression. In addressing the phenomenon of structural inequalities and neoliberalist service provision from the perspective of those affected, it will assist in a broader understanding of how social workers support service users to find supportive housing. Semi-structured interviews with community-based mental health social workers employed in Hamilton, Ontario were conducted and complement the existing literature on residential care facilities, the deterioration of the social welfare system, managerialism, and client-centeredness. This is an exploratory study as few previous research has been conducted with social workers in the context of lodging homes. Previous literature existed from the perspective of residents of lodging homes in Hamilton, Ontario. This research suggests that social workers are influenced by a complex number of phenomena in their daily work in order to make recommendations for supportive housing.

abstract: Thesis

abstract: Master of Social Work (MSW)


title: Study of bioaccumulation and radiobiological effects of environmentally relevant level of Radium-226

abstract:
The primary aim of this thesis is to investigate the bioaccumulation of environmental level of Ra-226 in fish and the induced radiobiological effects. Elevated Ra-226 levels in the environment are of increasing concern because of its high radiotoxicity and long half-life.
One in vivo study analyzed the accumulation of Ra-226 in fathead minnows exposed to environmental level of Ra-226 via ingestion. A second in vitro study focused on the biological effects of chronic low-dose radiation from Ra-226 and the induction of adaptive response.
The main findings of the thesis revealed that the accumulation of Ra-226 in fish was not linear in relation to the dietary Ra-226 activity. The highest concentration factor was obtained from lowest food activity, and uptake was inversely proportional to the dietary Ra-226 concentrations. The fish fed with radioactive food showed some growth suppression compared to control.
The results of the in vitro study indicated that chronic low-dose radiation from Ra-226 had an impact on the clonogenic survival of cells, but had no influence on the proliferation of cells. The reactions of CHSE/F (fish embryonic cells) and HaCaT (human epithelial cells) to chronic radiation from Ra-226 were different. After being cultured in medium containing Ra-226 over multiple generations, CHSE/F cells were sensitized by the radiation, while HaCaT cells were firstly sensitized and after several generations they showed the trend of getting adapted to the radiation. Furthermore, no adaptive response was induced by long-term low-dose radiation from Ra-226 when cells were subsequently exposed by acute high-dose challenge radiation, except for small adaptive responses at sporadic dose points.
This thesis may provide information about the transfer and influence of low-dose Ra-226. It may motivate other studies to estimate the risks of internal alpha-emitters, to identify the influence of chronic radiation on different species, and to develop radiation protection guidelines.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Development and validation of clinical prediction models to diagnose acute respiratory infections in children and adults from Canadian Hutterite communities.

contributor:
Loeb, Mark
Health Research Methodology

subject:
Prediction models
Recursive partitioning
Generalized Estimating Equations
Cox Proportional Hazard models
Acute respiratory infections
Score
Influenza
Decision trees

abstract:
Acute respiratory infections (ARI) caused by influenza and other respiratory viruses affect millions of people annually. Although usually self-limiting a more complicated or severe course may occur in previously healthy people but are more likely in individuals with underlying illnesses. The most common viral agent is rhinovirus whereas influenza is less frequent but is well known to cause winter epidemics. In primary care, rapid diagnosis of influenza virus infections is essential in order to provide treatment. Clinical presentations vary among the different pathogens but may overlap and may also depend on host factors. Predictive models have been developed for influenza but study results may be biased because only individuals presenting with fever were included. Most of these models have not been adequately validated and their predictive power, therefore, is likely overestimated. The main objective of this thesis was to compare different mathematical models for the
derivation of clinical prediction rules in individuals presenting with symptoms of ARI to better distinguish between influenza, influenza A subtypes and entero-/rhinovirus-related illness in children and adults and to evaluate model performance by using data-splitting for internal validation.
Data from a completed prospective cluster-randomized trial for the indirect effect of influenza vaccination in children of Hutterite communities served as a basis of my thesis. There were a total of 3288 first episodes per season of ARI in 2202 individuals and 321 (9.8%) influenza positive events over three influenza seasons (2008-2011). The data set was divided into children under 18 years and adults. Both data sets were randomly split by subjects into a derivation (2/3 of the dataset) and a validation population (1/3 of the dataset). All predictive models were developed in the derivation sets. Demographic factors and the classical symptoms of ARI were evaluated with logistic regression and Cox proportional hazard models using forward stepwise selection applying robust estimators to account for non-independent data and by means of recursive partitioning. The beta coefficients of the independent predictors were used to develop different point scores. These scores were then tested in the validation groups and performance between validation and derivation set was compared using receiver operating characteristics (ROC) curves. We determined sensitivities and specificities, positive and negative predictive values, and likelihood ratios at different cut-points which could reflect test and treatment thresholds. Fever, chills, and cough were the most important predictors in children whereas chills and cough but not fever were most predictive of influenza virus infection in adults. Performance of the individual models was moderate with areas under the receiver operating characteristic curves between 0.75 and 0.80 for the main outcome influenza A or B virus infection. There was no statistically significant difference in performance between the derivation and validation sets for the main outcome. The results have shown, that various mathematical models have similar discriminative ability to
distinguish influenza from other respiratory viruses. The scores could assist clinicians in their decision-making. However, performance of the models was slightly overestimated due to potential clustering of data and the results would first needed to be validated in a different population before application in clinical practice.

abstract: Thesis

abstract: Master of Science (MSc)

abstract:
Every year, millions of people are attacked by "the flu" or the common cold. Certain signs and symptoms apparently are more discriminative between the common cold and the flu. However, the decision between starting a simple symptom orientated treatment, treating empirically for influenza or ordering a rapid diagnostic test that has only moderate sensitivity and specificity can be challenging.
This thesis, therefore, aims to help physicians in their decision-making process by developing simple scores and decision trees for the diagnosis of influenza versus non-influenza respiratory infections.
Data from a completed trial for the indirect effect of influenza vaccination in children of Hutterite communities served as a basis of my thesis. There were a total of 3288 first seasonal episodes of ARI in 2202 individuals and 321 (9.8%) influenza positive events over three influenza seasons (2008-2011). The data set was divided into children under 18 years and adults. Both data sets were split into a derivation and a validation set (=holdout group). Different mathematical models were applied to the derivation set and demographic factors as well as the classical symptoms of ARI were evaluated. The scores generated from the most important factors that remained in the model were then tested in the validation group and performance between validation and derivation set was compared. Accuracy was determined at different cut-points which could reflect test and treatment thresholds. Fever, chills, and cough were the most important predictors in children whereas chills and cough but not fever were most predictive of influenza virus infection in adults. Performance of the individual models was moderate for the main outcome influenza A or B virus infection. There was no statistically significant difference in performance between the derivation and validation sets for the main outcome. The results have shown, that various mathematical models have similar discriminative ability to distinguish influenza from other respiratory viruses. The scores could assist clinicians in their decision-making. However, the results would first needed to be validated in a different population before application in clinical practice.


title: HYPERSPECTRAL IMAGING AND DATA ANALYSIS OF SKIN ERYTHEMA POST RADIATION THERAPY TREATMENT

contributor:
FANG, QIYIN
Biomedical Engineering

subject:
HYPERSPECTRAL IMAGING
SKIN ERYTHEMA

abstract: I DEVELOPED A NEW HIGH THROUGHPUT DUAL CHANNEL HYPERSPECTRAL IMAGING CONFIGURATION BASED ON ACOUSTO-OPTIC TUNABLE FILTER. THE DEVELOPED IMAGING SYSTEM WAS CHARACTERIZED AND EVALUATED IN COMPARISON WITH OTHER CONVENTIONAL CONFIGURATIONS. THE NEW IMAGING SYSTEM PROVED HIGHER THROUGHPUT WITH RESPECT TO THE CURRENTLY USED CONFIGURATIONS.THE IMAGING SYSTEM WAS THEN USED TO QUANTITATIVELY ASSESS AND PRECISELY CLASSIFY SKIN ERYTHEMA INDUCED ARTIFICIALLY ON VOLUNTEERS AND NATURALLY ON SKIN CANCER PATIENTS DUE TO RADIOTHERAPY TREATMENT.

abstract:
Recent cancer statistics show that 40% of Canadians might contract cancer during their life and 25% of Canadians might die due to cancer. In skin, head and neck cancers, surgery and radiation therapies are the most prevalent treatment options, while radiation therapy is the most commonly used approach. A common problem in radiation therapy is tumors behave differently against ionizing radiation. For instance, with the same dose, some tumors are fully damaged or shrunk, while others are less affected. The difference in individual tumor response to therapy is transformed into a research question: how to quantitatively assess tumor response to radiation and how to tune radiation therapy to achieve full destruction for tumor cells? Few past studies addressed the question, although no definite answer was realized.
This work is a part of a project that investigates the hypothesis that radiation response of skin is correlated to individual tumor response. In the case of high correlation, the skin’s faster response to ionizing radiation can be used to modify the irradiation dose to achieve the maximum destruction of individual’s tumor. To examine the project hypothesis, radiation-induced skin redness or erythema was selected as an acute skin reaction to being objectively quantified. Hence, the overall goal of the research thesis work is to objectively assess and precisely quantify radiation-induced erythema or radiation dermatitis. Skin erythema was assessed formerly by multiple optical and non-optical modalities. The current gold standard is the visual assessment (VA). Unfortunately, VA lacks objectiveness, precise communication, and quantification. To push the limitations of VA and past techniques, hyperspectral imaging (HSI) was proposed to be used for erythema assessment. The work detailed in this thesis aims to create more confidence in HSI to be utilized toward objectively quantify skin erythema. To reach this goal, initially, a new high-throughput dual channel acousto-optic tunable filter (AOTF)-based-HSI instrument was developed for monitoring radiation dermatitis. AOTF-HSI instrument design, implementation, and full characterization are presented. Second, the developed AOTF-HSI instrument is evaluated against a liquid crystal tunable filter (LCTF) instrument. Third, to be prepared for clinical operation, the AOTF-HSI equipment was used to classify an artificially-induced erythema on healthy volunteers in an exploratory study. A robust linear discriminant analysis (LDA)-based classification method was developed for the purpose of image classification. Finally, HSI instrument and LDA classification method were utilized in a preliminary clinical study to properly monitor and precisely quantify radiation dermatitis for skin cancer patients. In the clinical study, erythema indices were computed using Dawson’s method. Least square fitting was used to fit the acquired absorbance data, and thus quantify the hemoglobin concentration change along the study duration. Moreover, LDA was used to contrast spectral and digital imaging for erythema classification. In sum, the work documented in this thesis was willfully directed to achieve an efficient, portable, user-friendly hyperspectral imaging system which has the opportunity to be a benchtop in the clinical daily procedure in the near future.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Medical Students and Faculty Perceptions Towards a Case Based Learning Intervention at an Indian Medical College

title: Case Based Learning at an Indian Medical College

contributor:
Hunter, Andrea
Jain, Animesh
LaPierre, David
Global Health

subject:
case based learning
India
medical education

abstract:
Background: Current literature promotes a student-centred approach with an active learning design, as such curricula have demonstrated improvements in outcomes such as critical thinking and clinical competence. Current literature demonstrates success in North America and Europe. However, research in low-resource countries have highlighted resource- and satisfaction-related issues due to such shifts. This study implements a case-based learning (CBL) intervention at Kasturba Medical College Mangalore Campus (KMCMG), India. Faculty and undergraduate medical student perceptions are explored in order to understand the contextual factors that will lead to an effective, acceptable and feasible medical curriculum.
Methods: This cross-sectional, mixed-methods study employed a Likert scale questionnaire and semi-structured focus groups to 3rd year medical students (n=248), as well as semi-structured interviews with faculty (n=10) in the Department of Community Medicine. Cases were created through a co-development process with KMCMG faculty. Questionnaire data was analyzed by descriptive statistics and qualitative data was analyzed primarily by an inductive-iterative approach.
Results: Both faculty and students find CBL to be more valuable than the traditional lecture-based method, and find CBL meaningful for students as future physicians. Comments highlighted the importance of student preparedness and of trained facilitators in order to enhance the learning experience. A significantly larger proportion of Indian schooled students, versus those who studied abroad, felt that CBL helped acquire new information (p=0.016), enhanced their clinical approach (p=0.008), and believed the role of the facilitator was important (p=0.001).
Conclusion: Feedback towards CBL was found to be satisfactory in all aspects, and both students and faculty would like to see more CBL sessions in the future. Limitations such as faculty shortage and the inability to use informational technology at this time should be taken into consideration when moving forward. It is recommended that a resource-light version of CBL be considered, to provide robust orientations to faculty and students, and to further engage with faculty and students in order to enhance the CBL experience.

abstract: Thesis

abstract: Master of Science (MSc)