title: Development and Psychometric Assessment of the Evidence-Informed Decision-Making Competence Measure for Public Health Nursing

contributor:
Dobbins, Maureen
Nursing

subject:
public health nursing
competence assessment
evidence-informed decision-making

abstract:
Background: There are professional expectations for public health nurses to engage in and develop competencies in evidence-informed decision-making (EIDM). The purpose of this research study was to develop and psychometrically test a measure to assess competence in EIDM among public health nurses.
Methods: Guided by the Standards for Educational and Psychological Testing (American Educational Research Association, American Psychological Association, & National Council on Measurement in Education, 2014), a three stage study was employed to develop and psychometrically evaluate the new self-report EIDM Competence Measure: 1) Stage one: a systematic review of existing measures assessing four EIDM competence attributes of knowledge, skills, attitudes/beliefs, and behaviours; 2) Stage two: item development for the EIDM Competence Measure comprised of four subscales (knowledge, skills, attitudes/beliefs, and behaviours); and 3) Stage three: psychometric testing (reliability, validity, acceptability) which included item reduction from an original 40-item to a final 27-item tool.
Results: The EIDM Competence Measure consists of 27 items aligning with a four-factor model of EIDM knowledge, skills, attitudes/beliefs, and behaviours establishing internal structure validity. Cronbach’s alpha for these four factors was 0.96, 0.93, 0.80, and 0.94, respectively.
Significant associations between EIDM competence subscale scores and education, EIDM training/project involvement, and organizational culture established validity based on relationships to other variables. For the original 40-item tool, missing data was minimal as 93% of participants completed all items and mean completion time was 7 minutes and 20 seconds.
Conclusions: The EIDM Competence Measure is a conceptually and psychometrically robust instrument that has potential for use in public health nursing practice.

abstract: Dissertation

abstract: Doctor of Philosophy (PhD)

abstract: Nurses who work in public health have professional expectations to participate in evidence-informed decision-making (EIDM). Because of this, it is important to measure how competent they are in EIDM. The purpose of this study was to develop and test a tool that measures EIDM competence among public health nurses using a three-stage study. The first stage involved reviewing literature on existing tools that measure different components of EIDM competence including EIDM knowledge, skills, attitudes/beliefs, and behaviours among nurses. The second stage involved using existing tool items and developing new items for a new tool named the EIDM Competence Measure. In the third stage, the EIDM Competence Measure was tested to assess its validity, reliability, and acceptability among public health nurses in Ontario. The EIDM Competence Measure was found to have strong validity, reliability, and acceptability, showing that there is potential for its use in public health nursing practice.


title: High Temperature Creep Deformation of Silicon Nitride Ceramics

contributor:
Wilkinson, D.S.
Weatherly, G.C.
Materials Science and Engineering

subject:
high temperature
creep deformation
silicon nitride ceramics

abstract:
The compressive creep behaviour of a high purity silicon nitride ceramic with and without the addition of Ba was studied at 1400°C. Two distinct creep stages were observed during high temperature deformation of these materials. The stress exponents for creep of the two materials indicate that they have different creep mechanisms during the second stage of creep. Cavitation during creep was determined by measuring the density change before and after creep using a water-displacement method. The Ba doped material exhibited an obvious density decrease, indicating cavitation during creep, whereas the undoped material exhibited no cavitation. This is consistent with TEM observations. The microstructure of the materials, especially the amorphous grain-boundary phase was investigated for both as-sintered and crept specimans by means of transmission electron microscopy (TEM). Statistical analysis of a number of grain-boundary films indicates that the film thickness is confined to a narrow range (standard deviation less than 0.15 nm) in the as-sintered materials. The average film thickness depends on film chemistry, increasing from 1.0 nm to 1.4 nm when Ba is added. The standard deviation of the film thickness of a given material after creep, however, is considerably larger than before (0.30 nm ~ 0.59 nm). This suggests that the grain-boundary glass phase is redistributed during creep.
Viscous flow of the glass phase is proposed as die mechanism responsible for the first stage of creep. The data are compared with a model for viscous creep, yielding good correlation.

abstract: Thesis

abstract: Master of Engineering (ME)


title: An Experimental and Numerical Investigation of Turbulent Recirculating Flow within a Cavity with an Inlet Wall Jet

contributor:
Shoukri, M.
Mechanical Engineering

subject:
experimental
numerical investigation
turbulent recirculating flow
inlet wall jet

abstract: Recirculating turbulent flow within a cavity with an inlet wall jet was examined. In steady water flow velocity profiles were constructed with measurements taken with a Laser Doppler Anemometer system mounted on a traversing mechanism. Two test cases were examined Re jet = 1167 and Re jet = 3231 as well as developing wall jet profiles. The results are presented with mean velocity plots and turbulent kinetic energy contours. Comparisons are then made with results obtained using a finite difference computational scheme based on the k - e turbulence model. Good agreement was obtained between the computer code predictions and the experimental data.

abstract: Thesis

abstract: Master of Engineering (ME)


title: Confined Boiling Heat Transfer Over a Saturated Porous Structure

contributor:
Ching, C.Y.
Ewing, D.
Mechanical Engineering

subject:
confined boiling heat transfer
saturated porous structure

abstract: An experimental investigation was performed to study the confined boiling heat transfer characteristics over a saturated porous structure using distilled water as the working fluid. A thin stainless steel resistive foil stretched between two copper electrodes was used to heat a saturated porous plate with an effective pore size of 50 gm. The temperature distribution on the foil heater was measured using a high speed thermal imaging camera. The effect of the gap height between the heater and the porous plate on the heat transfer was investigated for gap heights ranging from 0 um to 1000 um and for heat fluxes ranging from 11.7 kW/m2 to 58.3 kW/m2. It was observed that the highest heat transfer rate was obtained at a gap height of approximately 600 pm. The main heat transfer mechanism is thought to be confined boiling in the small gap between the heating surface and the saturated porous structure. It was observed that the effect of the subcooled liquid temperature did not have a significant effect on the heat transfer. The effect of the pore size in the porous plate was investigated by repeating the measurements with a porous plate of 200 gm pore size. It was observed that the thermal resistance for the plate with a 200 gm pore size was significantly higher than the plate with 50 gm pores for gaps less than 300 gm. At a larger gap height of 600 gm, similar heat transfer performances were obtained for the two porous media.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: Investigations Into the Removal of Micro-Particles from Surfaces Using Ultrafast Lasers

contributor:
Haugen, Harold
Engineering Physics

subject:
micro-particles
ultrafast lasers
removal of micro-particles

abstract:
This thesis reports on the work performed on the manipulation of micro-particles on substrate surfaces using short laser pulses. For particles with diameters on the order of microns, the binding forces to surfaces are significantly larger than gravitational forces. To overcome these binding forces and manipulate the particles the use of femtosecond laser pulses has been investigated. Individual micro-particles (poly-divinylbenzene, glass and silver materials) with diameters around 2 um were removed from substrate surfaces (dielectric, semiconductor and metal substrates) using a Ti:Sapphire laser system. The pulses produced at 800 nm had pulse lengths around 140 fs and were tightly focussed onto the surface using 5x and 10x microscope objectives. The peak fluence thresholds for particle removal were determined and the surfaces examined after irradiation by a scanning electron microscope and atomic force microscope to check for damage. The experimental results indicate that ablation of the substrate below the micro-particles is most likely to be responsible for micro-particle removal from the substrate surface when using femtosecond pulses. Ablation pits were observed for the dielectric micro-spheres on semiconductor substrates. It is also believed that ablation is responsible for the removal of other types of micro-particles from various substrates. Unlike the dielectric micro-sphere on semiconductor substrate results, the other particle-substrate combinations show a close correspondence between the removal and substrate ablation thresholds. It is believed that these results indicate the occurrence of ablation leading to the removal of the micro-particles. Calculations of the local electromagnetic fields around the micro-particles have also been carried out and the distributions used to interpret the
experimental results.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: The Performance of a Waveguide-Coupled Metal-Semiconductor-Metal Optoelecctronic Matrix Switch

contributor:
Jessop, Paul
Engineering Physics

subject:
waveguide-coupled
metal-semiconductor-metal
optoelectronic matrix switch

abstract:
Metal-semiconductor-metal (MSM) photodetectors are becoming attractive devices for optoelectronic integrated circuits due to their high speed and simplicity. Optoelectronic matrix switches based on MSM detector arrays offer many advantages such as zero-bias off-state, low bias voltage, high speed and large bandwidth. While in many applications the optical input is coupled in through the top surface of the device, optical signals can also be distributed through transparent waveguides that are located below the absorbing detector layer. Such waveguide-coupled detectors will act as optical taps when the coupling between the waveguide and detector layers is well under control.
In this thesis, a 4x4 MSM waveguide-coupled optoelectronic matrix switch was demonstrated and analyzed. The strength of the coupling between the waveguide and detector layers was predicted theoretically and confirmed experimentally. Franz-Keldysh
effect in this device was also demonstrated.

abstract: Thesis

abstract: Master of Engineering (ME)


title: Polymer Functionalization of Single-Walled Carbon Nanotubes using Living Polymerization Methods

contributor:
Adronov, Alex
Chemistry

subject:
functionalization
single-walled carbon nanotube
polymerization method

abstract:
Single-w ailed carbon nanotubes (SWNTs) were oxidatively shortened and functionalized with ruthenium-based olefin metathesis catalysts. These catalyst-functionalized nanotubes were shown to be effective in the ring-opening metathesis polymerization of norbornene, resulting in rapid polymerization from the catalyst sites on the nanotube. It was found that high polymer molecular weights could be reached, and the molecular weight increased linearly with polymerization time. The resulting polynorbomene-functionalized nanotubes were found to exhibit solubility in organic solvents, while the starting materials and catalyst-functionalized nanotubes were completely insoluble. The polymerized materials were characterized by NMR, IR, DSC, AFM and TEM.
Polystyrene and poly[(t-butyl acrylate)-b-styrene] with well-defined molecular weights and polydispersities were prepared by nitroxide-mediated free-radical polymerization. The homo- and block-copolymers were used to functionalize shortened single-walled carbon nanotubes (SWNTs) through a radical coupling reaction involving polymer-centered radicals generated at 125°C via loss of the stable free-radical nitroxide capping agent. The resulting polymer-SWNT composites were fully characterized and were found to be highly soluble in a variety of organic solvents. This solubility could also be altered through chemical modification of the appended polymers. The t-butyl groups of appended PtBA-b-PS could be removed to produce poly[(acrylic acid)-b-styrene]- functionalized carbon nanotubes. The resulting composite was found to form aggregates in a mixture of chloroform/methanol (v/v: 1/1), as determined by
dynamic light scattering (DLS).

abstract: Thesis

abstract: Master of Science (MS)


title: Managing Discourse: Medical Heresy, Integrative Medicine and the Therapeutic Touch Debate

contributor:
Rodman, Bill
Anthropology

subject:
medical heresy
integrative medicine
therapeutic touch debate
managing discourse

abstract: In this thesis I examine the debate surrounding Therapeutic Touch, a controversial energetic healing modality being practiced by registered nurses in biomedical institutions across North America. The debate surrounding the therapy takes place within medical journals, popular media articles, and on the internet. Within the debate, definitions of illness etiology, appropriate treatment, patient management, and alternative therapy use are contested by Therapeutic Touch proponents and critics. Through discursive analysis, interviews with local participants in the debate, and participant observation within the TT community, I present an analysis of the issues being contested and of the discursive strategies used by proponents and critics within the debate. The debate is contextualized in two ways: first, as an instance of medical heresy, in which an alternative healing group arises within the orthodox medical community and struggles to maintain itself within biomedical discourse and institutions; second, I contextualize the debate as an example of the wider trend towards integrative medicine in North America. Integrative medicine sees alternative therapies being increasingly used within health care delivery systems, either by alternative practitioners, or by biomedical practitioners who have co-opted alternative techniques. I argue that Therapeutic Touch proponents have utilized several discursive strategies in presenting and arguing for their alternative healing model. These strategies surround the issues of professional legitimacy, scientific validity, and TT’s perception as religious or spiritual. Therapeutic Touch proponents manage their discourse by conforming it to orthodox biomedical discourse and by pursuing a strategy of professionalization. Through this management process, they have been able to maintain a marginal presence within biomedicine.

abstract: Thesis

abstract: Master of Arts (MA)


title: Huggins' k' as a Measure of Non-Linearity in Normal and Cross-Linked Polystyrene

contributor:
Cragg, L. H.
Chemistry

subject:
Huggins' k'
measure
non-linearity
normal polystyrene
cross-linked polystyrene

abstract: Polystyrene samples prepared in emulsion at 55 C were carefully fractionated. The resulting fractions were in turn fractionated, combined in groups having similar intrinsic viscosities, and re-fractionated. As the intrinsic viscosity of these fractions increased, the value of Huggins' k' in methyl ethyl ketone was found to increase a slightly ( from 0.39 to 0.41). Polystyrene samples prepared in exactly the same way except for the addition of small amounts of divinylbensene, a cross-linking agent, were similarly fractionated. The value of k' in methyl ethyl ketone for these fractions increased considerably (from 0.41 to 0.68) as the intrinsic viscosity increased, even though the amount of divinylbensene added was very small (from 0.003to 0.05%). Relations were then established for these cross-linked fractions between k' and the proportion of divinylbensene present, and between k' and the intrinsic viscosity of the fractions. It was concluded that polystyrene prepared in emulsion at 55 C. is essentially linear in structure, and that the value of Huggins' k* seems to provide a convenient and sensitive test for the presence of any appreciable branching that might occur in polystyrene.

abstract: Thesis

abstract: Master of Science (MS)


title: A Study of the Association Between Two Weevils (Sitophilus oryza L., and Sitphilus granarius L.,) and the Micro-Organisms of their Mycetomes

subject:
weevils
sitophilus oryze
sitophilus granarius
micro-organisms
mycetomes

abstract: A biological investigation of the apparently intimate and mutually relationship existing between certain plant-like micro-organisms and certain insects. The literature of the subject is briefly reviewed and discussed and a critical appraisal of previous work is made. A problem, the association of certain micro-organisms with two species of grain feeding weevils, is discussed in greater detail and a method of approach is proposed and analysed. Studies of the micro-organisms in vivo and in vitro are described in conjunction with investigations, by experimental techniques, of the association of the micro-organisms and the weevils. Findings are discussed and conclusions are presented.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: A Study of the Growth in vitro of the Proembryo and Prothallium of sinus nigra ARN. VAR austriaca A. & GR

contributor:
Redforth, N.W.
Biology

subject:
growth in vitro
proembryo
prothallium
pinus nigra

abstract: Little is known about fundamental mechanisms of growth control on the growth ff single or small groups of cells of the higher plants. Study of these effects in vitro requires the knowledge of the primary conditions for growth in vitro. In this work a procedure was outlined and used in an effort to establish a basis for the standard procedure. Also the associated effects of the physical, and to some extent, the chemical environment on the growth of the proembryo and prothallium. of Linus were studied.

abstract: Thesis

abstract: Master of Science (MS)


title: The Vapour-Phase Reaction of 2-Alkyltetrahydropyrans with Anilik over Alumina

contributor:
Bourne, A.N.
Chemistry

subject:
vapour-phase reaction
2-alkyltetrahydropyrans
aniline
alumina

abstract: The vapour-phase reaction of 2-methy-tetrhydropyran and 2-ethyltetralydropyran with aniline over an activated alumina catalyst has been studied. The product, in each case, consisted of a mature of an N-aryl-piperidine, an N-arylpyrrolidine formed by ring contraction, and two N-alkelnylanilines formed by ring opening. The structures of the nitrogen heterocyclic compounds were established by independent syntheses involving the reaction of the appropriate dibromoalkane with aniline. The N-alkenylanilines were characterised by hydrogenation to known N-alkylanilines and by identification of the osonolysis products.

abstract: Thesis

abstract: Master of Science (MSc)


title: An Experimental Study on the Effect of the Swimbladder on Hearing Sensitivity om Ameirus nebulosus nebulosus (Le Sueur)

contributor:
Kleerekoper, H.
Biology

subject:
experimental study
swimbladder
hearing sensitivity
ameirus nebulosus nebulosus

abstract: This thesis is concerned with the study on the effect of the swimbbadder on hearing sensitivity in Ameiurus nebulosus nebulosus. The investigation has been performed by means of auditory threshold curves in normal catfish and in catfish in which the resonance of the swimbladder was eliminated, The results were compared. The thesis consists of an introduction to the investigation, followed by a review of the literature in relation to the problem, a description of the material and technique and of the experimental work, the results obtained with a discussion and a summary.

abstract: Thesis

abstract: Master of Science (MS)


title: Effects of Age and Thermal Acclimation on the Selected Temperature and Thermal Resistance of Culcid and Simuliid Larvae (Diptera)

contributor:
Davies, D. M.
Biology

subject:
age
thermal acclimation
selected temperature
thermal resistance
culicid larvae
simuliid larvae

abstract: Black-fly larvae, and mosquito larvae and pupae, are shown to select certain temperature ranges when given a choice in a linear gradient. Larval age has little effect on the temperature selected, but pupae are tolerant of higher temperatures than larvae. The significance of this observation is discussed. The temperature selected is affected by the previous thermal history of the insect, although acclimation to the ambient temperature may be rapid. The final selected temperature of fourth-instar Aedes aegypti larvae was determined. Rearing temperature has a profound effect on the thermal resistance of Aedes aegypti exposed to high temperatures.

abstract: Thesis

abstract: Master of Science (MS)


title: Fabrication, Design and Characterization of Silicon-on-Insulator Waveguide Amplifiers Coated in Erbium-Doped Tellurium Oxide

contributor:
Bradley, Jonathan
Knights, Andrew
Engineering Physics

subject:
photonics
silicon
waveguide
amplifier
rare-earth
integrated optics
silicon photonics
silicon-on-insulator
tellurium oxide
erbium
sputtering

abstract:
This research introduces tellurium oxide (TeO2) glass doped with optically active erbium
ions (Er3+) as an active oxide cladding material for silicon-on-insulator (SOI) waveguides
for realization of a silicon-based erbium-doped waveguide amplifier (EDWA) for
integrated optics. Optical amplification of this nature is enabled by energy transitions,
such as stimulated absorption and emission, within the shielded 4f shell of the rare-earth
atomic structure caused by excitation from photons incident on the system. Er3+ ions
are doped into the TeO2 film during deposition onto the SOI waveguides using a reactive
magnetron co-sputtering system operated by McMaster’s Centre for Emerging Device
Technologies (CEDT). Prior to fabrication, the waveguides are designed using photonic
CAD software packages, for optimization of the modal behaviour in the device, and Matlab,
for characterization of the optical gain performance through numerical analysis of
the rate and propagation equations of the Er3+-based energy system. Post fabrication,
the waveguide loss and gain of the coated devices are experimentally measured. The
fabricated waveguide amplifier produces a peak signal enhancement of 3.84 dB at 1533
nm wavelength for a 1.7 cm-long waveguide device. High measured waveguide losses (>
10 dB/cm) produce a negative internal net gain per unit length. However, the demonstration
and implementation of an active rare-earth doped cladding material on a silicon
waveguide is successful, which is a major step in developing integrated optical amplifiers
for conventional silicon photonics platforms.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: Finite Element Analysis of Concrete Structures Subjected to Alkali-Aggregate Reaction

contributor:
Pietruszczak, S.
Civil Engineering

subject:
finite element analysis
concrete structures
alkali-aggregate reaction

abstract:
The alkali-aggregate reaction was first reported in 1940 as a cause of severe cracking in some concrete structures. It is only in recent years that papers have been published dealing with the effects of AAR on the performance of structures. This thesis outlines a methodology for numerical simulation of the response of concrete subjected to continuing AAR. First a constitutive model is presented based on the framework proposed by Pietruszczak (1996). The formulation incorporates an assumption that the rate of expansion depends on the confining pressure, the age of concrete and the temperature.
The progress in the reaction is coupled with the degradation of mechanical properties, in particular the elastic modulus and the compressive and tensile strengths. Subsequently, the procedures for generating finite element models are described, including geometric modeling, mesh generation techniques, graphical representation of the results and interfacing between pre- and post-processor and the finite element solvers. The numerical analysis, undertaken in this thesis, pertains to the Beauharnois Powerhouse, situated in Quebec, Canada. The powerhouse has been experiencing problems related to a continuing expansion of concrete due to AAR since the early 1960’s. The progressive formation of macrocracks and the volumetric expansion in concrete has caused operational problems, such as the reduction in clearance between turbine runner blades and throat rings. In this study, typical structural units of the Beauharnois Powerhouse were selected for the numerical analysis. The AAR constitutive model was applied in a finite element framework. Mechanical properties of concrete were carefully evaluated based on available experimental data. Simulations were focused on the deformation and the time history of progressive macro/microcracking due to continuing reaction. Structural responses under isothermal as well as non-isothermal conditions were simulated. The results of the numerical analyses were then compared with in-situ measurements.

abstract: Thesis

abstract: Master of Engineering (ME)


title: Outlier Detection in Gaussian Mixture Models

contributor:
McNicholas, Paul
Statistics

subject:
clustering
outliers
model selection
mixture models

abstract: Unsupervised classification is a problem often plagued by outliers, yet there is a paucity of work on handling outliers in unsupervised classification. Mixtures of Gaussian distributions are a popular choice in model-based clustering. A single outlier can affect parameters estimation and, as such, must be accounted for. This issue is further complicated by the presence of multiple outliers. Predicting the proportion of outliers correctly is paramount as it minimizes misclassification error. It is proved that, for a finite Gaussian mixture model, the log-likelihoods of the subset models are distributed according to a mixture of beta-type distributions. This relationship is leveraged in two ways. First, an algorithm is proposed that predicts the proportion of outliers by measuring the adherence of a set of subset log-likelihoods to a beta-type mixture reference distribution. This algorithm removes the least likely points, which are deemed outliers, until model assumptions are met. Second, a hypothesis test is developed, which, at a chosen significance level, can test whether a dataset contains a single outlier.

abstract: Thesis

abstract: Master of Science (MSc)


title: EVALUATING THE IMPACTS OF EXTREME WEATHER EVENTS ON THE INFRASTRUCTURE DEVELOPMENT OR CONSTRUCTION INDUSTRY IN ONTARIO

contributor:
Arain, Altaf
Earth and Environmental Sciences

subject: Construction companies, Extreme weather events, Companies operations

abstract:
In Canada, construction companies are facing disruptions to their operations due to bad or extreme weather conditions such as thunderstorms, heavy precipitation, flooding, heatwaves and snowstorms, which cause project delays, loss of productivity and increased financial costs. This sector is prone to more disruptions due to increase in the frequency, duration and intensity of extreme weather events due to future climate change. This study examined the impacts of extreme weather events on infrastructure development companies and investigated their current practices and actions to alleviate these impacts. A survey questionnaire was developed and administrated to owners, managers, engineers, supervisors and planners of construction companies. Apart from descriptive evaluations, the survey responses were quantitatively analyzed to determine the impact of bad weather conditions on the construction companies. The findings of this study suggested that most construction companies’ operations were delayed due to bad or extreme weather events. However, construction industry is not adopting proactive measures to avoid or minimize these impacts. The main environmental factors impacting construction companies, included flooding, high winds or thunderstorms, warm/cold temperatures, heatwaves and snow/ice storms. These bad weather impacts were more significant for non-government construction companies as compared to those working in the government sector. Indirect impacts of bad weather included disruptions to their supply chain networks and changes in customer behaviors; however, these impacts were minor compared to direct environmental impacts. The study found that both government and non-government sector construction companies granted accommodations to the workers during bad weather conditions; however, government sector companies were more accommodating as compared to non-government companies.
The study results also provided insight into the financial impacts of extreme weather events on construction companies. Weighted average losses for government sector companies were $2,200 per day of bad weather as compared to $8,155 per day for non-government companies. This suggested that non-government construction companies may experience serious financial consequences due to bad or extreme weather events. Study results further showed that there were no adequate guidelines, protocols or standards available to construction companies to adapt their operations and planning for extreme weather events. The study also highlighted the lack of adequate insurance products available for the construction sector to deal with bad weather. There was little tendency shown by the construction companies to use new technologies to deal with bad weather conditions. Therefore, there is an urgent need to develop guidelines, protocols or standards for construction companies by involving all levels of the government and relevant private sector organizations. This study helps to determine the nature and scale of extreme weather impacts on construction industry and explores what strategies may be developed to alleviate these impacts and risks. Such knowledge will help companies better plan and manage their operations and effectively use their human resources. It will help in timely delivery of services and savings in costs by the infrastructure development companies, which are a major contributor to the Canadian economy.

abstract: Thesis

abstract: Master of Science (MSc)


title: Is A-movement a movement? An eye-tracking and self-paced reading investigation

contributor:
Kučerová, Ivona
Cognitive Science of Language

subject:
linguistics
theoretical syntax
experimental syntax
eye-tracking
self-paced reading
A-movement

abstract:
In this thesis, I investigate the link between A-movement and online processing in eye-tracking and self-paced reading (SPR). A-movement refers to movement of an element to an argument position, where an element may be base-generated and hold a semantic role of the main predicate of the clause. I analyze six constructions in English, divided into three experimental pairings. Unaccusative constructions argued to involve movement are contrasted with unergatives as control, in a purely intransitive pairing. Transitive verb expectations are controlled by contrasting optional transitive constructions and purported movement in inchoative constructions. Argument alternation is taken into consideration in comparing instrumental constructions and possible movement in middle constructions.
The results from the SPR experiment did not show significant differences in reading times or fixation durations between pairings in any regions. In the eye-tracking results, no significant effects were found at the verb region, where the syntactic complexity of movement could lead to greater processing effort. In the subject noun region of the optional transitive and inchoative constructions and instrumental and middle constructions, significant differences in gaze duration, total fixation duration, and go-past time were found. These results are compatible with theories of frequency effects. Differences at the adverb could support lexical or derivational approaches, as controls and experimental conditions had equal length fixations in our first pairing, controls had longer fixations in our second pairing, and experimental items had longer fixations in our third pairing. Ultimately, the results do not offer strong support for the derivational approach, and are not accounted for through a lexical approach.

abstract: Thesis

abstract: Master of Science (MSc)


title: Aerobic exercise-induced functional and cellular adaptations in patients with myotonic dystrophy type 1

contributor:
Tarnopolsky, Mark
Kinesiology

subject:
Myotonic dystrophy type 1
exercise
mitochondria

abstract: Myotonic dystrophy type 1 (DM1) is the most common adult muscular dystrophy affecting ~1/8000 people worldwide. DM1 is characterized by accelerated skeletal muscle weakness and wasting, myotonia and insulin resistance, ultimately causing impaired function and diminished quality of life. A trinucleotide (CTG) repeat expansion in the 3’ region upstream of the DMPK gene results in dysregulation of several RNA binding proteins (RNABPs) important for muscle health such as MBNL and CUGBP1. Exercise was shown to ameliorate DM1 pathology in mice and to be safe for DM1 patients. This thesis aimed to investigate the muscular adaptations of 12-weeks of aerobic exercise in DM1 patients. Eleven DM1 patients (DM1, 42.6 ± 3 y) were recruited from the Neuromuscular and Neurometabolic clinic at McMaster University and age matched to healthy controls (CON, 42.5 ± 2 y). DM1 and CON performed incremental VO2peak testing, muscle and spirometry functional tests and a skeletal muscle biopsy from the Vastus lateralis. After 12-weeks of training on a cycle ergometer (3x/wk @ ~65 %VO2peak), DM1 patients completed post-testing. Exercise training significantly increased total lean mass (TLM) by ~ 1.6 kg (p<0.05) and fibre cross-sectional area by ~30 % in DM1 patients. Aerobic fitness was enhanced following training from 19.7 ± 1.5 mL/kg/min to 26.0 ± 2.1 mL/kg/min (p<0.05). Furthermore, training improved 6-min walk test, timed up & go, and 5X sit-to-stand scores (p<0.05).  Mechanistically, exercise modestly altered expression of RNABPs, and augmented mitochondrial function and protein content. This is the first study to comprehensively investigate the effects of aerobic training on muscle health and function in DM1. Our data provides evidence that exercise training can augment fitness, functional capacity and muscle mass in DM1. Further understanding the influence of exercise on DM1 pathology could outline the efficacy of a simple life intervention and provide insight for future pharmacological discoveries for DM1.

abstract: Thesis

abstract: Master of Science (MSc)


title: Methodological and analytical considerations on ranking probabilities in network meta-analysis: Evaluating comparative effectiveness and safety of interventions

contributor:
Hamid, Jemila S
Health Research Methodology

subject: network meta-analysis

subject: ranking probabilities

abstract:
Network meta-analysis (NMA) synthesizes all available direct (head-to-head) and indirect evidence on the comparative effectiveness of at least three treatments and provides coherent estimates of their relative effects. Ranking probabilities are commonly used to summarize these estimates and provide comparative rankings of treatments. However, the reliability of ranking probabilities as summary measures has not been formally established and treatments are often ranked for each outcome separately. This thesis aims to address methodological gaps and limitations in current literature by providing alternative methods for evaluating the robustness of treatment ranks, establishing comparative rankings, and integrating ranking probabilities across multiple outcomes. These novel tools, addressing three specific objectives, are developed in three papers.
     The first paper presents a conceptual framework for quantifying the robustness of treatments ranks and for elucidating potential sources of lack of robustness. Cohen’s kappa is proposed for quantifying the agreement between two sets of ranks based on NMAs of the full data and a subset of the data. A leave one-study-out strategy was used to illustrate the framework with empirical data from published NMAs, where ranks based on the surface under the cumulative ranking curve (SUCRA) were considered. Recommendations for using this strategy to evaluate sensitivity or robustness to concerning evidence are given.
     When two or more cumulative ranking curves cross, treatments with large probabilities of ranking the best, second best, third best, etc. may rank worse than treatments with smaller corresponding probabilities based on SUCRA. This limitation of SUCRA is addressed in the second paper through the proposal of partial SUCRA (pSUCRA) as an alternative measure for ranking treatments. pSUCRA is adopted from the partial area under the receiver operating characteristic curve in diagnostic medicine and is derived to summarize relevant regions of the cumulative ranking curve.
     Knowledge users are often faced with the challenge of making sense of large volumes of NMA results presented across multiple outcomes. This may be further complicated if the comparative rankings on each outcome contradict each other, leading to subjective final decisions. The third paper addresses this limitation through a comprehensive methodological framework for integrating treatments’ ranking probabilities across multiple outcomes. The framework relies on the area inside spie charts representing treatments’ performances on all outcomes, while also incorporating the outcomes’ relative importance. This approach not only provides an objective measure of the comparative ranking of treatments across multiple outcomes, but also allows graphical presentation of the results, thereby facilitating straightforward interpretation.
     All contributions in this thesis provide objective means to improve the use of comparative treatment rankings in NMA. Further extensive evaluations of these tools are required to assess their validity in empirical and simulated networks of different size and sparseness.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract:
Decisions on how to best treat a patient should be informed by all relevant evidence comparing the benefits and harms of available options. Network meta-analysis (NMA) is a statistical method for combining evidence on at least three treatments and produces a coherent set of results. Nevertheless, NMA results are typically presented separately for each health outcome (e.g., length of hospital stay, mortality) and the volume of results can be overwhelming to a knowledge user. Moreover, the results can be contradictory across multiple outcomes. Statistics that facilitate the ranking of treatments may aid in easing this interpretative burden while limiting subjectivity. This thesis aims to address methodological gaps and limitations in current ranking approaches by providing alternative methods for evaluating the robustness of treatment ranks, establishing comparative rankings, and integrating ranking probabilities across multiple outcomes. These
contributions provide objective means to improve the use of comparative treatment rankings in NMA.


title: Movement of Goods in Canada: A State-of-the-Art Review and a Grounded Theory Investigation of Perceived Barriers

title: PERCEIVED BARRIERS TO FREIGHT MOBILITY IN CANADA

contributor:
Paez, Antonio
Razavi, Saiedeh
Geography and Earth Sciences

subject:
Freight
Logistics
Canada
Grounded Theory
GT
Congestion
Freight Mobility
Last Mile
Qualitative Methods

abstract:
This twofold work first presents a state-of-the-art review of the roots and context for freight mobility barriers, and secondly investigates the key barriers to freight mobility in Canada from the perspective of stakeholders. The review provides a holistic approach to understanding the interconnected nature of mobility, spatial structure, congestion, supply chains, and the economy on generating, demanding, and hindering freight movements.
The investigation develops a novel theory grounded in the experiences of stakeholders following the Strauss/Corbin extended Grounded Theory approach of symbolic interactionism. From interviews with 28 industry and government stakeholders, a total of 50 themes emerged as barriers. These barriers were grouped into four categories which frame the issue of freight mobility as being impacted by high infrastructure utilization, cost impacts of diminishing distribution reliability, rapidly growing regions and ineffective or absent policy support, and lacking a robust data collection, analysis, and sharing framework.
The categories were considered in the frame of addressing goods movement barriers and were argued to be influenced by factors of cost, political risk, implement-ability, and maintainability. A framework was developed by integrating the emergent categories and factors, identifying four high-level interventions: data and knowledge mobilization; public-private collaborative freight evaluations; government funding and political support; and, capacity alterations: improvements and expansions. Overall, the key concepts of the emergent theory are to collect and analyze data to inform public-private stakeholder evaluations of policy interventions, with government funding to support both knowledge generation efforts, policy actions and capacity investments. There is a significant need to expand data collection and information sharing to enable firms and government to address physical and policy barriers which impede the effective goods movements, including infrastructure and land use planning. The theory is generally consistent with barriers identified internationally.

abstract: Thesis

abstract: Master of Science (MSc)

abstract:
This twofold work first presents a state-of-the-art review of the roots and context for hinderances to the movement of freight, and secondly, investigates the key barriers to freight mobility in Canada as perceived by Canadian stakeholders. The review provides a holistic approach to understanding the interconnected nature of mobility, spatial structure, congestion, supply chains, and the economy on generating, demanding, and hindering freight movements.
The investigation develops a novel theory grounded in the experiences of stakeholders in Canada. Emergent are categories which frame the barriers to freight mobility as high infrastructure utilization, diminishing reliability, rapidly growing regions, ineffective or absent policy support, and insufficient data collection and sharing. These categories are theorized to be influenced by cost, political risk, implement-ability, and maintainability considerations. The concepts are to collect and analyze data to inform stakeholder evaluations of policy interventions, with government funding to support knowledge generation, policy actions, and capacity investments.


title: DEVELOPMENT OF BIOFABRICATION TECHNIQUES TO ENGINEER 3D IN VITRO AVATARS OF TISSUES

contributor:
Selvaganapathy, Ponnambalam Ravi
Biomedical Engineering

subject:
Biomedical Engineering
Tissue Engineering
3D in vitro models
Biofabrication
Bioprinting
Bioassembly
Dynamic models

abstract: Two-dimensional (2D) in vitro models of tissues and organs have long been used as one of the main tools to understand human physiology and for applications such as drug discovery. But there is a huge disparity between in vivo conditions and these models which has created the need for better models. It has been shown that making three-dimensional models with dynamic environments that provide proper physical and chemical cues for cells, can bridge this gap between 2D models and in vivo conditions but the toolbox for creating such models has been imperfect and rudimentary. Introduction of tissue engineering concept and advent of biofabrication tools to meet its demands has provided new possible avenues for in vitro modeling but many of these tools are specifically designed to create tissue and organ replacements and lack features such as the ability to investigate cellular behavior with ease that are necessary for in vitro modeling purposes. The objective of this doctoral thesis was to introduce a novel toolbox of biofabrication techniques, based on bioprinting and bioassembly, that together are capable of recapitulating anatomical and physiological requirements of different tissue in in vitro setups in a more relevant way while creating the possibility of investigating cellular behavior. A bioprinting technique was developed that allowed formation of large constructs with proper mechanical stability, perfusion, and direct access to cells in different locations. The second technique was based on bioassembly of collagenous grafts in micro-molds and cells from different tissues with the ability to control cell positioning and create tissue-relevant cell densities with higher degree of similarity to human tissues compared to previous techniques. The third technique was based on bioassembled stand alone and dense cell-sheets for cells capable of fusion. These techniques were subsequently used for modeling a few chosen biological phenomenon to showcase the advantages of the techniques over previously developed ones and to further shed light on possible shortcomings of each of the techniques in their application for those specific tissues. In conclusion, our techniques may serve as valuable and easy to use tools for researchers, specifically biologists to investigate different aspects of human biology and disease mechanism in more details.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract: Experimentation on humans is unethical, therefore in order to understand how human body works and test new therapeutic drugs researchers have used animals and cells isolated from animals or humans. Animals are inherently different from humans and isolated cells are culture in conditions different than human body, therefore a huge gap exists between the knowledge derived from these models and what happens in human body. Since there is no one-size-fits-all technique to model all of the human tissues, the objective of current study was set to build a toolbox of techniques that each could create better environment in the lab for cells isolated from different tissues and organs with more similarity to original tissues, to bridge the gap and eliminate the need to use animal models entirely. During the course of this PhD studies, three different techniques that can be used to make such models for different tissues and organs, as well as different diseases, were developed and characterized. These techniques were also used to shed light on some of the cellular behavior that are already observed in human body but either are not explained or aren’t re-created in the lab for mechanistic studies. Certain questions regarding selected tissues were chosen and the technique most compatible with that tissue was used for the modeling purposes. For example, one investigated niche was the origin of the bone sensory cells which could be important to heal damaged bones or prevent osteoporosis. The first technique was deemed most suitable for this question while for the next question, how the fat and muscle cells are affecting each other that can be useful to better understand conditions such as diabetes and obesity, the second technique was the best option. Overall, a variety of tools were developed that can be used by biologists to create better models of human tissues in the lab as platforms to study human physiology and as media for developing treatments for different diseases.


title: Risk Assessment of Venous Thromboembolism and Bleeding in Hospitalized Medical Patients

title: VENOUS THROMBOEMBOLISM AND BLEEDING IN MEDICAL INPATIENTS

contributor:
Schünemann, Holger
Health Research Methodology

subject: risk assessment model, prediction, prognosis, venous thromboembolism, venous thromboembolism, bleeding, hospitalized medical patients, GRADE, guidelines, clinical expertise

abstract:
Determining the prognosis or risk of an individual experiencing a specific health outcome within a certain time period is essential to improve health. An important aspect of prognostic research is the development of risk assessment models (RAMs). In support of the movement towards personalized medicine, health care professionals have employed RAMs to stratify an individual patient’s absolute risk of developing a health condition and select the optimal management strategy for that patient. The development of RAMs is generally conducted using data driven methods or through expert consensus. However, these methods present limitations. Accordingly, we recognized the need to select factors for RAM development or update that are evidence-based and clinically relevant using a structured and transparent approach. In this sandwich thesis, I highlight the methods used to select prognostic factors for VTE and bleeding RAMs for hospitalized medical patients. However, the same methods can be applied to any clinical outcome of interest.
This work presents a conceptualized and tested novel mixed methods approach to select prognostic factors for VTE and bleeding in hospitalized medical patients that are evidence-based, clinically meaningful and relevant. Our findings may inform the development of new RAMs, the update of widely used RAMs, and external validation and prospective impact assessment studies. Also, these findings may assist decision makers in evaluating the risk of an individual having an outcome to optimize patient care.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract:
Measuring the probability of an individual experiencing a specific health outcome in a certain period of time based on that individual’s risk factors is important to improve health. Prediction tools are often used to calculate the probability of an outcome. Health care practitioners use prediction tools to assess an individual’s risk of a certain health outcome and in turn provide individualized management. Prediction tools include a number of agreed upon risk factors that should be assessed in order to best estimate the risk of an outcome. These risk factors are usually selected through exploring sets of data or by consulting a group of experts in the field. However, these methods have limitations. Therefore, we recognized that it is important, when developing prediction tools, to select risk factors that are evidence-based and clinically relevant by adopting a systematic, comprehensive, structured and transparent approach. These sets of risk factors can then aid health researchers when developing new prediction tools or updating existing ones and help clinicians predicting risk. In this thesis, I highlight the methods used to select factors for prediction tools that evaluate the risk of having a venous clot or a bleeding event in patients that are hospitalized for a medical condition. However, the same methods can be applied to any clinical condition and outcome of interest.
This work presents a new approach that we conceptualized and tested to select risk factors for venous clots and bleeding events in hospitalized medical patients that are evidence-based, clinically meaningful and relevant. Our findings may inform the development of new prediction tools, the update of widely used tools, and the design of studies to validate these tools. Also, these findings may assist decision makers in evaluating the risk of an individual having an outcome to optimize patient care.


title: ASSESSMENT OF HIP FRACTURE RISK IN OLDER ADULTS BY CONSIDERING THE EFFECT OF GEOMETRY AND BONE MINERAL DENSITY DISTRIBUTION IN THE FEMUR USING SINGLE DUAL-ENERGY X-RAY ABSORPTIOMETRY SCANS

contributor:
QUENNEVILLE, CHERYL
Mechanical Engineering

subject:
Hip fracture risk
DXA scan
Medical image processing
Older adults

abstract:
Hip fractures in older adults have severe effects on patients’ morbidity as well as mortality, so it is crucial to avoid this injury through the early identification of patients at high risk. Currently, the diagnosis of osteoporosis and consequently hip fracture risk is done through the measurement of bone mineral density by a dual-energy X-ray absorptiometry (DXA) scan. However, studies show that this method is not accurate enough, and a high percentage of patients who sustain a hip fracture had non-osteoporotic DXA scans less than a year before the incidence.
In this research, to enhance the hip fracture risk prediction, the effect of a femur’s geometry and bone mineral density distribution was considered in the hip fracture risk estimation. This was done through 2D and 3D statistical shape and appearance modeling of the proximal femur using standard clinical DXA scans. To assess the proposed techniques, destructive mechanical tests were performed on 16 isolated cadaveric femurs. Also, through collaboration with the Canadian Osteoporosis Study (CaMos), the proposed statistical techniques to predict the hip fracture risk were evaluated in a clinical population as well.
The results of this study showed that new techniques can enhance hip fracture risk estimation; in the clinical study, 2D and 3D statistical modeling were able to improve identifying patients at high risk by 40% and 44% over the clinical standard method. Also, the percentage of correct predictions using 2D statistical models did not differ significantly from the 3D predictions. Therefore, by applying these techniques in clinical practice it could be possible to identify patients at high risk of sustaining a hip fracture more accurately and eventually reduce the incidence of hip fractures and the pain and social and economic burden that comes with it.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract:
Diagnosis of osteoporosis and consequently hip fracture risk is based on the measurement of bone mineral density in clinical imaging called DXA scanning. However, studies have shown that this method is not sufficient in identifying all patients at high risk of sustaining a hip fracture.
The purpose of this work was to incorporate the geometry and bone mineral density distribution of the proximal femur in hip fracture risk prediction through image processing of DXA scans.  Two algorithms of 2D and 3D statistical shape and appearance modeling were implemented and evaluated in a cadaveric study (comparing the predicted fracture load to measured ones) as well as a clinical study (comparing the fracture predictions to the fracture history of patients).
The results indicated that new techniques can enhance hip fracture risk estimation compared to the clinical standard method, and hence the devastating injury can be prevented through applying protective measures.


title: Effects of Glycosaminoglycans on DNase-Mediated Degradation of DNA, DNA-Histone Complexes, and NETs

contributor: Medical Sciences (Thrombosis & Haemostasis & Atherosclerosis)

subject:
Sepsis
Neutrophil Extracellular Traps (NETs)
Extracellular DNA
DNA-Histone Complexes
DNase I
DNase1L3
Glycosaminoglycans

abstract:
Neutrophil extracellular traps (NETs) are a link between infection and coagulation in sepsis. The major structural component of NETs is nucleosomes, consisting of DNA and histones. NETs not only act as a scaffold to trap platelets, but NET components also promote coagulation and impair fibrinolysis. Thus, removal of extracellular DNA by DNases may be a potential therapeutic strategy for sepsis. Since heparin is used for thromboprophylaxis in sepsis and may also be a potential anti-sepsis therapy, we investigated the mechanisms by which various forms of heparins modulate DNase function.
There are two types of DNases in vivo: DNase I (produced by exocrine and endocrine glands) and DNase1L3 (secreted by immune cells). DNase I cleaves free DNA, whereas DNase1L3 preferentially cleaves DNA in complex with proteins such as histones. In this study, we investigated how DNase I and DNase1L3 activities are modulated by the following heparins: unfractionated heparin (UFH), enoxaparin (a low-molecular-weight heparin), Vasoflux (a low-molecular-weight, non-anticoagulant heparin), and fondaparinux (the pentasaccharide unit).
Using agarose gel experiments, we showed that UFH, enoxaparin, and Vasoflux enhance the ability of DNase I to digest DNA-histone complexes (presumably by displacing DNA from histones), whereas fondaparinux does not. These findings are consistent with the KD values of the binding of heparin variants to histones, with fondaparinux having >1000-fold lower affinity for histones compared to the other heparins. Taken together, our data suggests that the ability of heparin to enhance DNase I-mediated digestion of DNA-histone complexes is size-dependent and independent of the pentasaccharide region of heparin. With respect to DNase1L3, we observed that it is able to digest histone-bound DNA, and that all heparins, except fondaparinux, inhibited DNase1L3-mediated digestion of histone-bound DNA.
Next, we visualized the degradation of NETs by fluorescence microscopy. DNase I (± heparin variants) completely degraded NETs, presumably by digesting extracellular chromatin at histone-free linker regions, thereby releasing nucleosome units. DNase1L3 also degraded NETs, but not as effectively as DNase I, and was inhibited by all heparins except fondaparinux. Finally, we showed that DNase I levels are decreased and DNase1L3 levels are elevated in septic patients. Taken together, our findings demonstrate that heparin modulates the function of DNases, and that endogenous DNase levels are altered in sepsis pathophysiology.

abstract: Thesis

abstract: Master of Science (MSc)

abstract: Sepsis, a life-threatening condition due to hyperactivation of the immune system in response to infection, results in widespread inflammation and blood clotting. During sepsis, immune cells release sticky strands of DNA that block blood vessels and damage organs. Two different enzymes in the blood (DNase I and DNase1L3) can digest these DNA strands, and may represent a new class of anti-sepsis drugs. Our goal was to determine how heparins, commonly used blood thinners, alter the function of these enzymes. We found that (a) larger-sized heparins improved the activity of DNase I towards DNA-histone complexes and do not require any specific portion of heparin, (b) DNase I is more efficient than DNase1L3 in digesting DNA strands released from immune cells, and (c) levels of DNase I and DNase1L3 are altered in septic patients. Taken together, our studies provide new insights into how these enzymes function.


title: Good Character and Philosophy in Plato's Republic

contributor:
Johnstone, Mark
Philosophy

subject:
Philosophy
Ancient Philosophy
Ethics
Virtue
Plato
Republic

abstract: In this thesis, I argue that the ethical theory Plato develops in the Republic assigns critical importance to the role of one’s moral dispositions in their ability to make progress in philosophy. On this view, cultivating a good character, although not sufficient for pursuing philosophy, is necessary for success in philosophic endeavor. Conversely, having a vicious character precludes one from being able to acquire wisdom, which is the goal of philosophy. This is in contrast to Socratic intellectualism, which Plato is commonly seen to have adhered to in his earlier writings. The intellectualist view holds that knowledge is sufficient for virtue, and so one naturally becomes virtuous through the acquisition of wisdom. In other words, rather than virtuous character being necessary for philosophy, it is merely an effect of becoming wise. I argue that Plato moderates this kind of intellectualism in Republic in a way that makes the relationship between moral virtue and wisdom bidirectional. I demonstrate the plausibility of this thesis by examining an array of themes in the Republic, starting with the nature of philosophy and what it means to be a philosopher, and concluding with a look at the theory of education Plato advances throughout the dialogue.

abstract: Thesis

abstract: Master of Philosophy (MA)


title: Multisegment Injection-Nonaqueous Capillary Electrophoresis-Mass Spectrometry Based Metabolomics for Rapid Analysis of Fatty Acids for Dietary and Cardiometabolic Risk Assessment

contributor:
Britz-McKibbin, Philip
Chemistry and Chemical Biology

abstract: Biomarkers play a key role in human health for early disease screening for public health, improved diagnosis of human diseases, and monitoring of treatment responses on an individual level. However, there is urgent need for high throughput technologies to accelerate biomarker discovery based on comprehensive analyses of metabolites and lipids in complex human biofluids. This thesis contributes to new advances in metabolomics research and biomarker discovery in three major areas. In specific, this thesis describes (1) the development and validation of a multiplexed separation platform based on multisegment injection-nonaqueous capillary electrophoresis-mass spectrometry (MSI-NACE-MS) for the rapid and accurate determination of fatty acids and synthetic environmental lipids in blood specimens, (2) the application of this technique in support of nutritional epidemiology for objective assessment of dietary fat intake in women that can be correlated with self-reported food frequency questionnaires, and (3) the discovery of a panel of serum biomarkers for differentiation of peripheral artery disease (PAD) in older persons at high risk for limb amputation and death. Chapter I provides an introduction in biomarkers and metabolomics, including an overview of the data workflow when performing comprehensive metabolite profiling with emphasis on methods applicable to comprehensive fatty acid analysis. Chapter II introduces a novel assay based on MSI-NACE-MS for high throughput analyses of nonesterified or total hydrolyzed fatty acids in serum/plasma extracts following a rigorous method optimization and an inter-method comparison to conventional gas chromatography (GC) to demonstrate good mutual agreement. MSI-NACE-MS enables multiplexed analyses of seven samples within a single run with stringent quality control, robust inter-batch correction, and accurate electromigration modeling for lipid identification without pre-column chemical derivatization and complicated sample workup procedures. Chapter III further expands concentration sensitivity when using MSI-NACE-MS/MS for rapid biomonitoring of low nanomolar levels of perfluoroalkyl substance (PFAS) exposures as they are a class of ubiquitous environmental pollutants with endocrine-disruption functions. Perfluorooctanoic acid and perfluorooctanesulfonic acid were quantified in a subset of serum extracts from pregnant women before and after 2009 with lower exposures measured in accordance with enforced PFAS regulation. Chapter IV demonstrates the clinical utility of circulating NEFA for accurate nutritional assessment of fat intake in women. MSI-NACE-MS was applied in observational and intervention studies to demonstrate that polyunsaturated omega-3 and saturated odd-chain NEFAs serve as promising dietary biomarkers to monitor intake of oily fish/fish oil supplement and full-fat dairy intake, respectively. Chapter V describes an untargeted characterization of the serum metabolome of nondiabetic PAD patients for differentiation of chronic limb-threatening ischemia from intermittent claudication as compared to the ankle brachial index. A panel of serum metabolites, including several amino acids and fatty acids were identified as promising clinical biomarkers for early diagnosis and/or prognostication of PAD that also provides insights into its underlying pathophysiology. Lastly, Chapter VI provides an overview of the major contributions derived from this thesis, as well as a perspective on future research initiatives.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Efforts Towards Functionalizing a DNAzyme for Non-Invasive Colorectal Cancer Detection

contributor:
Li, Yingfu
Biochemistry and Biomedical Sciences

subject:
DNAzyme
colorectal cancer
Fusobacterium nucleatum
biosensor
stool
target identification

abstract:
The need for a non-invasive, accurate, easy-to-use, and cost-effective colorectal cancer (CRC) detection device is apparent in the low survival rates seen in late-stage diagnoses. Once CRC has progressed past stage I, the 5-year survival rate drops significantly, and treatment options become less favourable. The best way to treat CRC is to catch it early. The development of an RNA-cleaving fluorogenic DNAzyme (RFD) holds the potential to remediate this deficiency. A DNAzyme, called RFD-FN1, was identified from a synthetic random-sequence DNA library to selectively bind to an unknown target associated with Fusobacterium nucleatum, which has been found to be overabundant in pre- and cancerous colorectal tissue and stool. Target recognition by the DNAzyme induces the cleavage of a fluorogenic substrate and generates a fluorescent signal to indicate the presence of the bacterium. This thesis outlines the efforts made towards functionalizing the F. nucleatum-responsive probe in stool samples to create a non-invasive screening test.
RFD-FN1 is selective towards a heat-stable F. nucleatum protein, but its limit of detection is only 10^7 CFU/mL. Although able to detect spiked concentrations of F. nucleatum cells in processed stool samples, the use of heat, filtering, centrifugation, antibiotics, culturing or serial dilutions are not sufficient to detect the F. nucleatum that is naturally present in the diseased samples. Experiments designed to enrich the target concentration revealed that the target is not produced consistently in any growing condition tested.
Size exclusion chromatography and mass spectrometry analysis identified five potential targets that RFD-FN1 may be responding to. Three candidate targets were cloned and purified, but they failed to induce RFD-FN1’s activity. Due to the COVID-19 pandemic, the purification of the final two proteins was not completed. Purifying the two candidate targets and testing their ability to induce RFD-FN1 represents future research efforts. If the target for the DNAzyme is confirmed, a reselection for a more sensitive DNAzyme, that can function in human stool, can be attempted.

abstract: Thesis

abstract: Master of Health Sciences (MSc)


title: Restoration of Massasauga Rattlesnake (Sistrurus C. Catenatus) Overwintering Habitat: Design, Construction and Ecohydrological Assessment

contributor:
Waddington, James Michael
Earth and Environmental Sciences

subject:
Restoration
wetlands
Species at risk
overwintering
peatland
Sphagnum

abstract: The eastern massasauga rattlesnake, or massasauga, is threatened in Ontario. Massasaugas overwinter in habitat that is sufficiently moist, above the water table, and below the zero-degree isotherm in a physical space conceptualized as a resilience zone. A development project in the Eastern Georgian Bay subpopulation of massasaugas overwintering habitat necessitated restoration. The Toronto Zoo hibernacula design was deemed inappropriate for use in this bedrock dominated landscape, as the limited deep groundwater percolation would result in flooding of the habitat from the fall to spring. Massasaugas in EGB, overwinter above the water table in Sphagnum peat hummocks. The ecohydrological factors of these hummocks in confirmed massasauga habitat were evaluated in a mixed effect linear model. It was found that taller hummocks, taller shrubs, and less WT variability were the best predictor of suitable conditions. This information was combined into a restoration method that moves surficial peat material from a soon to be impacted wetlands to an adjacent depression with mean depths of 40-80 cm, with mean bottom substrates 15-30 cm, and varying proportions of open water and floating peat with different vegetation communities. This design limits water table variability and allows for the growth of tall shrubs. Unforeseen circumstances meant that peat to be used in the project had to be stockpiled, which increased peat bulk density and limited photosynthesis. Despite this, restored habitat had similar mean lengths of unsuitable conditions compared to confirmed massasauga wetland habitat. The physical size of available overwintering habitat, as well as the total duration of unsuitable conditions, was not significantly different between restored wetlands, unconfirmed wetlands, and confirmed wetlands. Amendments to increase the cover of live Sphagnum moss will likely increase the duration and size of suitable conditions in the restored wetlands. Based on this success with degraded materials this new method of restoration design shows great promise in this region.

abstract: Thesis

abstract: Master of Science (MSc)


title: Improving the accuracy of statistics used in de-identification and model validation (via the concordance statistic) pertaining to time-to-event data

contributor:
Pond, Gregory R.
Mathematics and Statistics

subject:
Statistics
Time-to-Event Analysis
Survival Analysis
De-identification
Anonymization
Model Validation
Concordance Statistic
AUC

abstract:
Time-to-event data is very common in medical research. Thus, clinicians and patients need analysis of this data to be accurate, as it is often used to interpret disease screening results, inform treatment decisions, and identify at-risk patient groups (ie, sex, race, gene expressions, etc.). This thesis tackles three statistical issues pertaining to time-to-event data.

The first issue was incurred from an Institute for Clinical and Evaluative Sciences lung cancer registry data set, which was de-identified by censoring patients at an earlier date. This resulted in an underestimate of the observed times of censored patients. Five methods were proposed to account for the underestimation incurred by de-identification. A subsequent simulation study was conducted to compare the effectiveness of each method in reducing bias, and mean squared error as well as improving coverage probabilities of four different KM estimates. The simulation results demonstrated that situations with relatively large numbers of censored patients required methodology with larger perturbation. In these scenarios, the fourth proposed method (which perturbed censored times such that they were censored in the final year of study) yielded estimates with the smallest bias, mean squared error, and largest coverage probability. Alternatively, when there were smaller numbers of censored patients, any manipulation to the altered data set worsened the accuracy of the estimates.

The second issue arises when investigating model validation via the concordance (c) statistic. Specifically, the c-statistic is intended for measuring the accuracy of statistical models which assess the risk associated with a binary outcome. The c-statistic estimates the proportion of patient pairs where the patient with a higher predicted risk had experienced the event. The definition of a c-statistic cannot be uniquely extended to time-to-event outcomes, thus many proposals have been made. The second project developed a parametric c-statistic which assumes to the true survival times are exponentially distributed to invoke the memoryless property. A simulation study was conducted which included a comparative analysis of two other time-to-event c-statistics. Three different definitions of concordance in the time-to-event setting were compared, as were three different c-statistics. The c-statistic developed by the authors yielded the smallest bias when censoring is present in data, even when the exponentially distributed parametric assumptions do not hold. The c-statistic developed by the authors appears to be the most robust to censored data. Thus, it is recommended to use this c-statistic to validate prediction models applied to censored data.

The third project in this thesis developed and assessed the appropriateness of an empirical time-to-event c-statistic that is derived by estimating the survival times of censored patients via the EM algorithm.  A simulation study was conducted for various sample sizes, censoring levels and correlation rates. A non-parametric bootstrap was employed and the mean and standard error of the bias of 4 different time-to-event c-statistics were compared, including the empirical EM c-statistic developed by the authors. The newly developed c-statistic yielded the smallest mean bias and standard error in all simulated scenarios. The c-statistic developed by the authors appears to be the most appropriate when estimating concordance of a time-to-event model. Thus, it is recommended to use this c-statistic to validate prediction models applied to censored data.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Structural Basis of Amyloid Oligomer Toxicity and Inhibition by Small Molecules and Molecular Chaperones

contributor:
Melacini, Giuseppe
Biochemistry and Biomedical Sciences

subject:
Alzheimer's Disease
Parkinson's Disease
Amyloid Beta
Alpha Synuclein
Nuclear Magnetic Resonance
Biophysics
Membrane
Oligomers
Structure
Toxicity

abstract: Protein misfolding and the accumulation of insoluble aggregates is a hallmark of several neurodegenerative disorders, including Alzheimer’s (AD) and Parkinson’s disease (PD). In AD and PD patients, extracellular protein deposits consisting of amyloid beta (Aβ) and intraneuronal inclusions composed of alpha synuclein (αS) are observed, respectively. Notably, the spatiotemporal patterning of soluble protein oligomers of αS and Aβ closely follow disease progression, giving support to an emerging role of soluble oligomers in PD and AD pathogenesis. However, the structural features underlying the toxicity of Aβ and αS oligomers remain elusive. This doctoral dissertation aims at elucidating the structural determinants of oligomer toxicity by focusing on the development and application of multidisciplinary approaches based primarily on solution NMR in combination with electron microscopy, multi-angle light scattering, fluorescence microscopy, wide-angle x-ray diffraction and cellular biophysics. Using this interdisciplinary approach, in chapters 2 and 3, we identify at atomic resolution the key structural elements that facilitate the colocalization, interaction and subsequent insertion of soluble Aβ oligomers into membranes, which ultimately result in the loss of membrane integrity. Notably, we show that small molecules, such as green tea catechins, remodel these structural features and effectively perturb the interactions with membranes. In chapter 4, we extend these analyses to αS and identify how the chaperone, Human Serum Albumin (HSA), remodels toxic αS oligomers into non-toxic species and breaks the catalytic cycle that generates new toxic oligomers. Lastly, in chapter 5, we describe a novel solution NMR approach to map at atomic resolution the sites of early self-association, with minimal bias from monomer dynamics, an effect that frequently dominates residue-dependent variations in solution NMR measurements. Overall, given that Aβ and αS are archetypical amyloidogenic proteins, we anticipate that the structure – toxicity relationships established herein, and the related experimental approaches may be transferrable to other amyloidogenic systems.

abstract: Dissertation

abstract: Doctor of Philosophy (PhD)


title: Alumina Directed Ortho Allylation of Phenols

contributor:
Magolan, Jakob
Biochemistry and Biomedical Sciences

subject: alumina

abstract:
The structures of natural products have long inspired and motivated innovation in organic chemistry.   Chemists strive to compete with the efficiency and selectivity of biological enzymatic reactions.  This thesis describes the development of a new synthetic methodology that enables a regioselective allylation of phenols that is analogous to the remarkable transformations done by prenyltransferase enzymes.
The main topic of this thesis is covered in Chapters 1 and 2.  In Chapter 1 prenyltransferase enzymes are introduced and the significance of aromatic allylation chemistry in Nature is discussed.   Synthetic methods for the allylation of phenols are thoroughly reviewed.   This research begins with the use of alumina, a heterogeneous reagent, to promote an indole alkylation reaction.   Next, the discovery and development of an alumina-directed ortho-selective allylation of phenols is described.   Mechanistic investigations and reaction optimization are described.  The robust substrate scope of this reaction is illustrated via the synthesis of 52 allylic phenols and this new methodology is applied to the synthesis of anti-inflammatory drug candidate L-651896.
In Chapter 2, this new methodology is applied to the synthesis of five natural products.   Natural products have long been of interest in pharmaceutical sciences, originating long before modern medicine with thousands of years of treatment of disease with traditional plant-based remedies.  Studies of traditional medicines and natural products led to the discoveries some modern drugs such as aspirin, digitoxin, morphine, quinine and pilocarpine.  Prenylated phenols are ubiquitous among natural products in the plant kingdom and in traditional medicine.  In this chapter, our alumina-directed ortho-selective allylation has been applied in the efficient synthetic preparation of five plant-derived prenylated phenolic natural products: cannabigerol, grifolin, piperogalin, amorphastibol, and iroko.
In Chapter 3, the total synthesis of the alkaloid natural product veranamine is described followed by the synthesis and biological evaluation of a library of veranamine analogues.  Veranamine binds to sigma 1 and 5HT2B receptors and has demonstrated potent antidepressant activity in a mouse assay.  The synthesis of one of the veranamine analogues is made possible by the alumina-directed ortho-allylation methodology that is the main focus of this thesis.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: INVESTIGATING THE ASSOCIATIONS BETWEEN CARDIORESPIRATORY FITNESS, SLEEP AND COGNITION IN AGING.

contributor:
Heisz, Jennifer J.
Kinesiology

subject: Sleep Exercise Cognition Memory

abstract: With increasing age there is a decline in cognitive functions, including episodic memory and executive functioning. This decline is thought to be related to changes in sleep, as sleep quality and quantity also decline with aging. Physical activity is a promising tool that has been found to increase both sleep and cognition in older adults. Physical activity has been shown to protect executive functions against poor sleep in older adults. However, it is unknown if physical activity also helps to protect memory against poor sleep, and if this relationship differs by age. The present study investigated the relationship between cardiorespiratory fitness, sleep, and memory in both older and young adults. Twenty-six older adults (M ± SD: 70.7 ± 2.8) and thirty-five young adults (M ± SD: 21.0 ± 3.1) completed the Rockport 1-mile walk test to measure cardiorespiratory fitness. Participants wore an actigraph for one week to measure habitual sleep, and returned for a second visit to perform tasks assessing episodic memory and executive functioning. An interaction was found between sleep quality and cardiorespiratory fitness (p = .021), in that sleep enhanced memory for low fit older adults (p = .047) but not for high fit older adults (p = .19). Sleep also predicted executive functioning performance in older adults (p = .007), but this association was observed regardless of cardiorespiratory fitness. No significant relationships were observed between cardiorespiratory fitness, sleep, and cognition in young adults. Overall, these results suggest the relationship between cardiorespiratory fitness and sleep may differ for episodic memory and executive functions. Given that these aspects of cognition are supported by different underlying neurological processes, fitness and sleep may provide complementary support for the aging brain. Future research should further investigate the underlying mechanism for the relationship between sleep, cardiorespiratory fitness, and cognition.

abstract: Thesis

abstract: Master of Science (MSc)


title: An Axial-Flux Switched Reluctance Motor for Light Electric Vehicles

contributor:
Ali Emadi, Berker Bilgin
Mechanical Engineering

subject: electric motor axial flux reluctance vehicle

abstract:
In an increasingly urgent climate crisis, the use of electric powertrains in smaller,
purpose-built vehicles can expedite the global adoption of electrification. This thesis discusses
the detailed design of an axial-flux switched reluctance motor for application in a light electric
vehicle, such as an E-motorcycle. A vehicle application is studied based on typical driving
conditions in an urban environment. The requirements of the propulsion motor are extracted,
and a baseline machine topology is analyzed for its performance and manufacturability,
towards the goal of a functional prototype. The prototype design includes a self-supporting
foil winding, designed to maximize the use of axial space and allow for good conductive heat
transfer to the machine casing. The rotor structure is found to be a limiting factor, where
maximum speed is limited by the mechanical stresses.
The performance of the motor is analyzed in detail, beginning with a numerical iron
loss model that is implemented to provide faster simulation time of the machine efficiency
than FEA. The efficiency is found to peak at 90%, comparable with other traction motors
of similar size on the market. The switching angles are studied, and the trade-offs between
torque quality and efficiency are quantified over the drive cycle. It was determined that
the vehicle could save 19.6 Wh/km by accepting poor torque quality and operating with
the most efficient control parameters. Thermal analysis is performed to determine the
realistic performance limitations. The machine was found to have power ratings of 7.12
kW instantaneous and 4.76 kW continuous. The final temperature of the winding during the
drive cycle was predicted not to exceed the temperature ratings of the insulation system.
Finally, the prototype is assembled, and a test plan is outlined for qualification of the motor.

abstract: Thesis

abstract: Master of Applied Science (MASc)

abstract:
This thesis documents the design of a new type of electric motor that is intended to be used
in a small electric vehicle. The electric motor is different from the majority of motors used
in this application for two reasons: firstly, the motor is a switched reluctance motor, which
means that it does not contain any permanent magnets, offering cost savings and additional
robustness. Secondly, the machine takes the form of a disk, where the magnetic interface
between rotating and stationary components is on the face perpendicular to the axis of
rotation. Normally, electric motors have the magnetic interface on the cylindrical surface
which is parallel to the axis of rotation. The disk form factor presents multiple design
challenges, which when coupled with the switched reluctance motor type, are addressed.
A series of mathematical models are built to predict the performance of the motor in the
vehicular application. Finally, a prototype of the motor is constructed.


title: Development of a Modified Anthropomorphic Test Device for the Quantification of Behind Shield Blunt Impacts

title: Quantification of Loading for Behind Shield Blunt Impacts

contributor:
Quenneville, Cheryl
Mechanical Engineering

subject:
Anthropomorphic Test Device
Ballistic Shield
Crash Test Dummy
Mechanical Design
Pneumatic Impactor

abstract:
Ballistic shields are used by defense teams in dangerous situations as protection against threats such as gunfire. When a ballistic shield is struck, the shield material will deform to absorb the kinetic energy of the incoming projectile. The rapid back-face deformation of the shield can contact the arm, which can impart a large force over an extremely short duration. This work modified an Anthropomorphic Test Device (ATD) to be used for the characterization of behind ballistic shield blunt impact loading profiles.

The modified ATD was instrumented to measure impacts at the hand, wrist, forearm, and elbow to compare the force transfer at different locations of impact. A custom jig was designed to support the ATD behind a ballistic shield, provide a high degree of adjustability, and be subjected to impact testing. Two ballistic shield models, both with the same protection rating, were tested and showed to have statistically different responses to the same impact conditions, indicating further need for shield safety evaluation.

To apply these loading profiles to future injury criteria development tests, a pneumatic impacting apparatus was re-designed that will allow the high energy impact profiles to be re-created in the McMaster Injury Biomechanics lab. Understanding the ballistic impact conditions, as well as the response of different ballistic shield models provided insight into the possible methods available to reduce upper extremity injury risk. This work has provided essential data for informing a future standard for shield safety evaluation.

abstract: Thesis

abstract: Master of Applied Science (MASc)

abstract:
When a ballistic shield is impacted by a bullet it deforms to absorb the incoming energy. The high-speed deformation of the shield material can impact the arm leading to fracture and possible life-threatening risks if the shield is dropped due to this injury. At the time of this work, there were no standards that limited the amount of allowable back-face deflection or tools available that could measure the force transferred to the arm in this scenario.

The purpose of this work was to develop a measurement device that could measure the force transferred to the arm from the behind shield impact. An existing crash test dummy arm was modified to provide measurement capabilities for this loading scenario. Ballistic shield testing was conducted where two different ballistic shield models were impacted to observe how the impact force changed with shield design, as well as the distance the device was placed behind the shield. A pneumatic impacting apparatus was then re-designed in the McMaster Injury Biomechanics lab that will allow the ballistic impact conditions to be re-created for evaluating the injury tolerance of the arm. The results of this work will be used to inform the future development of a ballistic shield evaluation standard.


title: Numerical Analysis of Two-Asset Options in a Finite Liquidity Framework

contributor:
Pirvu, Traian
Mathematics and Statistics

subject:
Mathematical Finance
Derivative Pricing
Stochastic Analysis
Computational Finance
Machine Learning
Deep Learning

abstract:
In this manuscript, we develop a  nite liquidity framework for two-asset
markets. In contrast to the standard multi-asset Black-Scholes framework,
trading in our market model has a direct impact on the asset's price. The
price impact is incorporated into the dynamics of the first asset through a
specific trading strategy, as in large trader liquidity models. We adopt Euler-
Maruyama and Milstein scheme in the simulation of asset prices. Exchange
and Spread option values are numerically estimated by Monte Carlo with the
Margrabe option as a controlled variate. The time complexity of these numerical
schemes is included. Finally, we provide some deep learning frameworks
to implement these pricing models effectively.

abstract: Thesis

abstract: Master of Science (MSc)


title: The ecology and network structure of mushroom-insect interactions from two forest regions in Southern Ontario

contributor:
Xu, Jianping
Biology

subject:
Mushroom-insect interactions
DNA barcoding
Network analyses

abstract: Mushrooms and insects are both integral components of ecosystems worldwide. Interactions between these two groups of organisms are particularly interesting to study due to the transient nature of mushroom fruiting bodies, which form for a short period of time when environmental conditions are optimal to allow the fungus to distribute its spores. Despite this unpredictability in where and when mushrooms will grow, a variety of insect species use mushrooms as a food source and a substrate on which to lay their eggs. Interactions between these two groups of organisms have been documented extensively in Europe. However, little is known about the diversity of insects that associate with mushrooms in Canada. In this study, 1,017 mushrooms were collected from forests in Hamilton and the Tillsonburg, Ontario regions between fall 2018 and fall 2019. Mushrooms and their associated insects were identified through DNA barcoding using sequences of the nuclear ITS region and the mitochondrial CO1 gene for the mushrooms and insects, respectively. In total, more than 100 insect species from at least 35 families and five orders were identified from the approximately 200 mushroom species collected. While some insect species displayed evidence of specificity in their choice of mushroom host, the larger network of associations was moderately generalized and many insect species inhabited mushrooms from multiple families and orders. This study highlights the incredible diversity of organisms that rely on mushrooms for survival and contributes to our overall understanding of mushroom-insect associations in this region of Southern Ontario.

abstract: Thesis

abstract: Master of Science (MSc)

abstract: Mushrooms and insects are both highly important organisms within ecosystems around the world. Mushrooms play key roles in breaking down organic matter within forests and contributing to plant health, while insects are important decomposers and pollinators. This project involved collecting over 1,000 mushrooms from two regions in Southern Ontario and identifying the insect species found living within these mushrooms in order to examine patterns in the interactions. To our knowledge, this is the first time a survey of mushroom-insect associations has been conducted in Canada. The collected mushrooms were inhabited by a diverse range of insect species, which included mostly flies and beetles, and each of the main sampling locations had their own unique mushroom and insect communities. Some insect species displayed preference in their choice of mushroom host.  Overall, this study contributes greatly to our current understanding of mushroom and insect diversity in this part of Canada.


title: Paper-Based Extraction and Amplification of Bacterial Genomic DNA to Monitor Food Safety

contributor:
Filipe, Carlos
Chemical Engineering

subject:
food safety
rapid bacterial detection
bacterial detection
food monitoring

abstract:
The development of rapid detection methods for bacterial contamination in the industrial agriculture sector is vital for improving food safety and public health. Furthermore, it is important to tailor these rapid methods for low-resource settings, because the majority of foodborne illness outbreaks occur in developing nations. Currently, the most widely used methods rely on nucleic acid testing using the polymerase chain reaction (PCR). This detection reaction provides repeatable results, is highly sensitive, and is highly specific, as it can detect a single strain within a species. However, PCR is reliant on proper sample pre-treatment to remove inhibitory contaminants which can affect downstream results, which leads to a trade-off between detection time and sensitivity of results. Rolling circle amplification (RCA) is another potential detection reaction which has the same advantages and is also better suited to low-resource settings, as it works at room temperature.
This thesis reports on the development of a rapid sample preparation method that can be seamlessly integrated into simple PCR and is also well suited to low-resource settings due to the low cost and high availability of the required reagents. A modification of the hot sodium hydroxide plus tris (HotSHOT) lysis reaction was implemented to extract genomic DNA (gDNA), which was then captured onto cellulose filter paper, allowing for multiple samples to be simultaneously processed in under 30 minutes. This pre-treatment can even recover gDNA for detection from samples that would have caused complete inhibition of PCR. The calculated limit of detection (LoD) of extraction followed by simple PCR was similar to that of government-approved commercial kits, without needing a lengthy bacterial enrichment step. Improvements are needed to make this a truly quantitative detection system. Finally, our paper-based pre-treatment was integrated into an RCA reaction to detect at least 105 cells, which provides proof-of-concept for combining paper-based sample preparation with isothermal amplification of target nucleic acids.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: Exploring Women's use of Facebook pages to discuss their experiences of Miscarriage and Pregnancy Loss

contributor:
Ion, Allyson
Social Work

subject:
Social Work
Social Sciences

abstract: Miscarriage and pregnancy loss are deeply personal and painful experiences for women and their families.  These losses are publicly unacknowledged and represent an undeveloped area within social work practice and research. It is estimated that between fifteen and twenty percent of pregnancies end in miscarriage, this population of women encounter medical and social care spaces that do not adequately meet their needs for recognition, validation and support (SOGC, 2017). The present study explores the ways in which women use the online social networking site Facebook to seek out opportunities to share their stories and engage in exchanges of support with others who have miscarried. Furthermore, through a thematic analysis of posts and comments shared to the “Miscarriage & Pregnancy Loss” Facebook page, this study utilizes Feminist Standpoint Theory to examine how women describe their experiences of miscarriage and pregnancy loss, which yields three distinct themes. First, miscarriage is a multi-layered experience for women that involves physical, emotional, psychological and social levels of embodiment and meaning. Second, women acknowledge that interactions with medical professionals reproduce harmful ideas and language that minimizes their experiences. Subsequently, women resist and counteract these ideas and language in their comments and exchanges of support with one another. Third, women engage with the idea of a maternal identity, which for some, endures following miscarriage, while for others motherhood is framed as something they almost achieved. This exploratory research provides insights into the utility of online resources and support networks in developing an understanding of the impacts of miscarriage and pregnancy loss, and how women use these spaces to offer words of empathy and compassion to one another.

abstract: Thesis

abstract: Master of Social Work (MSW)


title: Modelling Annual Bike Share Ridership at Hubs with Bike Share Expansion in Mind

contributor:
Scott, Darren M.
Geography

subject:
Active Travel
Public Bike Share System
Hub Usage
Ridership
Sustainable Transportation
Travel Behavior

abstract: Public bike share systems have been recognized as an effective way to promote active and sustainable public transportation. With the health benefits of bike share becoming better understood, North American cities have continued to invest in cycling infrastructure and impose new policies to not only encourage the usage of bike share systems but also expand their operations to new cities. The city of Hamilton, Ontario, implemented its own bike share system in March 2015. Using the system’s global positioning system (GPS) data for annually aggregated trip departures, arrivals, and totals in 2017, this research explores various environment factors that have an impact on users’ bike share usage at hub level. Nine predictive linear regression models were developed for three different scenarios depending on the type of hubs and members for trip departures, arrivals, and totals. In terms of variance explained across the core service area, the models suggested the main factors that attract users were distance to McMaster University and the number of racks available at hubs. Furthermore, the working population and distance to the Central Business District and the closest bike lane in the immediate vicinity (200 m buffer) also played important roles as contributing factors. Based on the primary predictors, this research takes one step further and estimates potential trips at candidate sites to inform future expansion of public bike share system. The candidate locations were created on appropriate land uses by applying a continuous surface of regularly shaped cells, a hexagonal tessellation, on the area of interest. The estimated potential usage at candidate sites demonstrated that the east part of the city should be targeted for future bike share expansion.

abstract: Dissertation

abstract: Master of Science (MSc)