Theses, Dissertations, and other Required Graduate Degree Essays

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This collection contains digitized SFU theses except for those theses submitted within the last 12 months. If you cannot find the thesis you are looking for please search Recently Submitted Theses as it may be a recently submitted thesis and thus not yet available in Summit.

Then, and only then: Long sleeves and endless dreams

Author: 
Date created: 
2018-11-27
Abstract: 

A two-part personal narrative as an attempt to provide a memoir in letter form, written from my current self to my future self, after time and age have potentially ravaged my body and mind. Part One offers the purpose behind the letters: why they are important and what they purport to do for the intended reader. It also uses authors who have played with the life-writing and memoir/narrative genre and how they influenced my own ideas of remembering. Part Two is a series of poems, followed by letters that detail and chronicle various memories through different points in place and time; an effort to remind myself how I was formed by my past, and inevitably, what I may become in the future. The narrative unfolds while consciously trying to avoid certain moments and accentuating others. It is an interplay between familiar memories, reminiscences constructed over time, and dream-like representations.

Document type: 
Graduating extended essay / Research project
File(s): 
Senior supervisor: 
Stephen Duguid
Department: 
Arts & Social Sciences: Liberal Studies Program
Thesis type: 
(Project) M.A.L.S.

Exploring substrate specificities of novel Burkholderia sp. isolates towards sustainable energy: benzoate degradation by new B. xenovorans strains

Author: 
Date created: 
2018-12-10
Abstract: 

Sustainable energy technologies demand the use of renewable sources of energy and materials, such as biomass. Remediation of toxic wastes is a related problem. The recalcitrance of the aromatic heteropolymer lignin, commonly found in plant biomass, is a major challenge for its sustainable transformation to energy and biomaterials. Biological approaches for degrading lignin and xenobiotic aromatic pollutants show great promise and are effective in some recent applications. This work aims at investigating the biodegradation activity of the newly discovered Burkholderia sp. isolates in alkali lignin, aromatic hydrocarbons, and n- or iso-alkanes under aerobic condition. Results show that no degradation was observed for alkali lignin inoculated with B. xenovorans. However, the novel B. xenovorans strains were able to grow and utilize benzoate (1 mg mL–1) as the sole carbon source in a minimal medium (M9) at relatively fast rate. HPLC analysis showed the presence of catabolic intermediates that were further used by the bacteria for growth. A 1H NMR analysis confirmed the presence of catechol as the central intermediate having a yield of 31.21 mg after hours of incubation. Furthermore, the new endophytic B. phytofirmans isolates also showed growth on M9 plates containing isooctane as the sole carbon source. More work is needed to determine the mechanism of degradation in isooctane, a recalcitrant branched alkane, by the novel B. phytofirmans. Overall, this study reveals the degradation potential of the new Burkholderia sp. isolates, in which the provided information can be harnessed for advanced applications and biotransformation strategies.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Jeffrey J. Warren
Department: 
Science: Department of Chemistry
Thesis type: 
(Thesis) M.Sc.

A combinatorial description of the cup product for smooth complete toric varieties

Author: 
Date created: 
2018-12-11
Abstract: 

For any smooth variety X, there exists an associated vector space of first-order deformations. This vector space can be interpreted using sheaf cohomology; it is the first cohomology group H^1(X,T_X), where T_X is the tangent sheaf. One can ask when it is possible to "combine" two first-order deformations. The cup product takes elements of H^1(X,T_X) x H^1(X,T_X) and maps to the obstruction space H^2(X, T_X), and the vanishing of the cup product tells us precisely when this is possible. In this thesis we give a combinatorial description of the cup product (on the level of Čech cohomology) when X is a smooth, complete, toric variety with an associated fan Σ. We also give an example of a smooth, complete, toric 3-fold for which the cup product is nonvanishing.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Nathan Ilten
Department: 
Science: Department of Mathematics
Thesis type: 
(Thesis) M.Sc.

A randomized air filter intervention study of air pollution and fetal growth in a highly polluted community: the Ulaanbaatar Gestation and Air Pollution Research (UGAAR) study

Author: 
Date created: 
2018-10-01
Abstract: 

Background: Gestational exposure to fine particulate matter (PM2.5) and cadmium may impair fetal growth. Portable high efficiency particulate air (HEPA) filter air cleaners can reduce indoor PM2.5, but their effect on fetal growth has not been evaluated. Objectives: We assessed (1) HEPA cleaner effectiveness in reducing residential indoor PM2.5 and maternal blood cadmium, (2) the effect of HEPA cleaners on fetal growth, and (3) the relationship between maternal cadmium exposure and fetal growth, among non-smoking pregnant women in Ulaanbaatar, Mongolia. Methods: We randomized 540 participants at ≤ 18 weeks gestation to an intervention (1-2 HEPA cleaners in homes from early pregnancy until childbirth) or control (no HEPA cleaners) group. We collected exposure, health, and demographic data through home and clinic visits and from clinic records. We measured one-week indoor PM2.5 concentrations in early (~11 weeks gestation) and late (~31 weeks gestation) pregnancy, collected blood samples in late pregnancy for analysis of cadmium, and obtained birth data at delivery. We evaluated the effect of the intervention on our primary outcome, birth weight, and other fetal growth indicators using unadjusted linear and logistic regression and time-to-event analysis, in intention-to-treat analyses. We also used multiple linear and logistic regression to assess the relationships between log2-transformed blood cadmium and fetal growth. Results: HEPA cleaners reduced indoor PM2.5 and blood cadmium concentrations by 29% (95% CI: 21, 37%) and 14% (95% CI: 4, 23%), respectively. Among 463 live births, the median (25th, 75th percentile) birth weights for control and intervention participants were 3450 g (3150, 3800 g) and 3550 g (3200, 3800 g), respectively, but the intervention was not associated with an increase in birth weight (18 g; 95% CI: -84, 120 g). In a pre-specified subgroup analysis of 429 term births the intervention was associated with an 85 g (95% CI: 3, 167 g) increase in mean birth weight. A doubling of blood cadmium was associated with an 86 g (95% CI: 26, 145 g) reduction in birth weight. Conclusions: Our findings provide further evidence that PM2.5 and cadmium exposures during pregnancy impair fetal growth and that exposure reduction during pregnancy can reduce these effects. Portable HEPA cleaners are an effective household-level intervention but reductions in air pollution emissions are needed to realize the largest public health benefits.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Ryan Allen
Department: 
Health Sciences: Faculty of Health Sciences
Thesis type: 
(Thesis) Ph.D.

The influence of risk assessment evidence on judicial sentencing decisions

Author: 
Date created: 
2018-12-11
Abstract: 

Despite the increased presence of risk assessment evidence in sentencing proceedings, its role has been contentious, and judges’ use of this evidence is unclear. This study examines judges’ opinions about risk assessment tools and assesses the influence of tools on judicial sentencing decisions. Specifically, it uses an experimental vignette design to evaluate whether judges’ impressions of a hypothetical offender or their sentencing recommendations are affected by the presence of an empirically-supported tool and accompanying risk rating. Participants were 170 judges from 34 American states and two Canadian provinces. The most common advantage of tools highlighted by judges was that they provide information that is helpful for making decisions, while the most common concern was their potential to obscure bias. Judges’ impressions and placement recommendations were not significantly influenced by tool presence. Judges’ program recommendations, however, were more intensive and consistent for the high-risk offender when a tool was present.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Jodi Viljoen
Department: 
Arts & Social Sciences: Department of Psychology
Thesis type: 
(Thesis) M.A.

Development and application of an In Vivo test for estimating biotransformation rate constants and bioconcentration factors of hydrophobic organic chemicals in fish

Author: 
Date created: 
2018-10-04
Abstract: 

Bioconcentration factors (BCFs) are the most commonly used metric by regulatory agencies to assess the bioaccumulation of chemicals in fish. However, due to logistical and economic constraints to laboratory testing, there is limited empirical BCF data. In addition, there are no accepted in vivo methods to measure biotransformation rates of hydrophobic organic chemicals (HOCs) in fish. This study presents a method for measuring in vivo biotransformation rate constants and BCFs of HOCs in aqueous bioconcentration tests. BCF tests were conducted for the test chemicals; methoxychlor, pyrene, cyclohexyl salicylate and 4-n-nonylphenol using a sorbent phase as a dosing reservoir. A co-exposure using non-biotransformed reference chemicals was used to derive biotransformation rates of the test chemicals. The tests were successful for measuring depuration and biotransformation rate constants (kT, kM), and BCFs in fish that will contribute empirical data for evaluating predictive models (e.g., in vitro to in vivo extrapolation; IVIVE) and in vitro kMs.

Document type: 
Graduating extended essay / Research project
File(s): 
Senior supervisor: 
Frank Gobas
Department: 
Environment: School of Resource and Environmental Management
Thesis type: 
(Project) M.R.M.

How Iceland Writers Retreat markets itself as an international writers event

Author: 
Date created: 
2018-12-10
Abstract: 

The first Iceland Writers Retreat (IWR) was held in 2014. It has since grown to be an annual event that boasts participants from around the globe, who travel to Iceland to learn from internationally renowned faculty, immerse themselves in the literary traditions of Iceland, and explore an unforgettable setting. This report outlines and examines Iceland Writers Retreat marketing efforts, particularly online. Further, it historicizes the beginning and inspirations of IWR, and delineates IWR’s role within both the landscape of international writing events and the liminal space it occupies between the Icelandic tourism industry and cultural sphere. It aims to outline marketing best practices that can be useful not only to other writing retreats and events, but also to any cultural organization that is moving their marketing efforts primarily online. Finally, it attempts to highlight opportunities for IWR to continue to grow their audience—both online and at the event.

Document type: 
Graduating extended essay / Research project
File(s): 
Senior supervisor: 
Leanne Johnson
Department: 
Communication, Art & Technology: Publishing Program
Thesis type: 
(Project) M.Pub.

Cell towers and the ambient population: A spatial analysis of disaggregated property crime in Vancouver, BC

Author: 
Date created: 
2018-12-10
Abstract: 

The current study employs a new measure of the ambient population, constructed using cell tower location data from OpenCellID, to compare residential and ambient population-based crime rates in Vancouver, BC. Five disaggregated property crime types are examined at the dissemination area level. Findings demonstrate striking differences in the spatial patterns of crime rates constructed using these two different measures of the population at risk. Multivariate results from spatial error models also highlight the substantial impact that the use of a theoretically-informed crime rate denominator can have on Pseudo R2 values, variable retention, and trends in significant relationships. Implications for theory testing and policy are discussed.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Martin Andresen
Department: 
Arts & Social Sciences: School of Criminology
Thesis type: 
(Thesis) M.A.

Game theoretic models of clear versus plain speech

Author: 
Date created: 
2018-11-27
Abstract: 

Clear speech is a speaking style intended to improve the comprehension of the hearer, which is usually due to the external noise, less ideal listening conditions, or the speaker is intended to be more intelligible. Clear speech, which exhibits increased duration, pitch, amplitude, and more exaggerated articulation, consumes more energy in order to improve the likelihood of accurate communication. To strike a balance between the cost of clear speech and the improvement it brings, we use game theory to model the phenomenon of clear speech. The conventions that speakers and hearers use to communicate are considered as equilibria in the communication game, and we need to make predictions of how the equilibria changes under the different circumstances. How our models correspond to what is experimentally observed, and what predictions are made for experimental results are discussed in the thesis. In the basic model, we study the case where the speaker has to send one of two messages equally likely in one-dimensional acoustic space. Next, we make a further discussion of the basic model in a priori probability of the sent message, the number of messages, and the conflicts between clearness and comprehensibility. The third contribution of this thesis is to extend the one-dimensional acoustic space to two dimensions, by introducing uncontrastive and contrastive features.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Paul Tupper
Department: 
Science: Department of Mathematics
Thesis type: 
(Thesis) M.Sc.

Activity monitor reliability and validity in community-dwelling older adults

Author: 
Date created: 
2018-11-20
Abstract: 

Monitoring older adult physical activity is central to surveillance of individual and population health as well as delivery and evaluation of health promotion programs, and it requires reliable and valid measurement tools. I investigated step count test-retest reliability and criterion validity across consumer-grade activity monitors in community-dwelling older adults with and without self-reported mobility limitations during over-ground walking (n = 36; mean 71.4 years). I evaluated six activity monitors (Fitbit Charge, Fitbit One, Garmin vívofit 2, Jawbone UP2, Misfit Shine, and New-Lifestyles NL-1000) during two 100-step walks, one continuous 400-metre walk, and one interrupted 400-metre walk. On average, all monitors undercounted steps. Step counts from hip-worn monitors generally exhibited better reliability and validity than from wrist-worn monitors. Mobility status did not affect monitor step count errors, but interruptions to walking negatively impacted criterion validity. The hip-worn Fitbit One was the only monitor with sufficiently high test-retest reliability and criterion validity.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Dawn Mackey
Department: 
Science: Department of Biomedical Physiology and Kinesiology
Thesis type: 
(Thesis) M.Sc.