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.

Abduction, Rebellion and Reprieve: The Narratives of Former Members of the Lord's Resistance Army

Date created: 
2015-01-14
Abstract: 

A prominent feature of rebel insurgencies in Africa is the use of abduction to recruit fighters. This research investigates forced recruits who embrace the role of rebel within the Lord’s Resistance Army (LRA). The study seeks to understand the motivations for abductees to stay and gain rank within the group that abducted them and by doing so illuminates the role that forced recruits play in the endurance and survival of armed groups that rely on abduction as a means of recruitment. The research was conducted through twenty interviews with former LRA soldiers during four months of fieldwork in northern Uganda. All participants had been recruited through abduction and have now taken up the Government amnesty and returned home. The results demonstrate that the LRA retains its recruits through finely tuned internal control mechanisms. It uses the threat of violence and manipulates a cultural belief in spirits, which both prevent people from trying to escape. Contrary to the findings in previous research, the LRA does not terrorise their recruits into staying. The LRA gives rank when recruits demonstrate compliance and commitment. In turn, rank reaffirms commitment to the group. A recruit has to demonstrate ability, initiative, courage, and the ability to kill on the battlefield; in short, they have to show they are a good soldier. Those that are not good soldiers die during the fighting, or are killed by their own side. The benefits of rank are largely non-material: rank gives a recruit respect and power within the group, and the ability to ‘marry,’ all cultural conceptions of masculinity. Overall, forced recruits stay with the LRA because gaining rank offers them status that civilian life cannot, while internal control mechanisms in the group make leaving undesirable. This research demonstrates that forced recruits are not traumatized into staying with armed groups, but rather are effectively initiated into becoming soldiers through processes that promote compliance and allegiance to the group. In conclusion, this project, by closely examining the phenomena of forced recruitment, sheds new light on the neglected issue of the role that forced recruits play in the endurance of illicit groups.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Curt Griffiths
Department: 
Arts & Social Sciences:
Thesis type: 
(Thesis) Ph.D.

Modelling the climate response to anthropogenic carbon dioxide emissions: time-dependent processes, commitment, and reversibility

Author: 
Date created: 
2017-04-13
Abstract: 

This thesis gives insight into key aspects of the climate system response to anthropogenic carbon dioxide (CO2) emissions. One characteristic is an approximately constant global mean surface air temperature (GMSAT) after cessation of emissions, but also changes in GMSAT to second order. Here it is shown that these second-order GMSAT changes are positive, i.e. there is a small committed warming from previous emissions, because the warming effect from declining ocean heat uptake dominates over the cooling effect from declining atmospheric CO2. The timing of zeroing emissions or the time horizon over which the warming commitment is calculated have minor effects on this warming commitment compared to the effect of the scenario prior to cessation of emissions. Another characteristic explored is the approximately constant ratio between GMSAT change and cumulative CO2 emissions (CE), referred to as Transient Climate Response to cumulative CO2 emissions (TCRE). It is shown that the TCRE diverges more strongly over time from a constant value under increasing atmospheric CO2 concentration than previously suggested. But it is approximately constant over time under constant CO2 concentration due to cancelling effects of changes in ocean heat and carbon uptake. Applying a wide range of sub-grid ocean mixing parameterizations does not change the temporal evolution of the TCRE significantly but leads to a wide range in the TCRE value. A third characteristic explored is irreversibility of sea level rise from thermal expansion (TSLR). It is shown here that TSLR under negative emissions does not return to pre-industrial levels for centuries after atmospheric CO2 has returned to pre-industrial concentrations. This result is robust against the choice of mixing parameter, although, generally an increased parameter leads to higher TSL rise and decline rates. The results presented in this thesis suggest that setting cumulative CO2 emission budgets in order to not exceed a certain warming target needs to be done with caution as the TCRE varies more strongly over time than previously shown and additional committed warming may lower allowable carbon budgets. Furthermore, TSLR is not linearly related to cumulative CO2 emissions and is slow to be reversed if net negative emissions are applied.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Kirsten Zickfeld
Department: 
Environment: Department of Geography
Thesis type: 
(Thesis) Ph.D.

Determining threat status for data-limited fisheries based on catch-only stock assessment models

Date created: 
2017-02-09
Abstract: 

Catch-only stock assessment methods have been developed to manage data-limited fisheries where only catch data is available. This research evaluated the ability of four catch-only stock assessment methods to correctly classify a stock of concern based on population trends. To accomplish this, true trends from simulated stocks and the trends produced by the models were used to classify stocks into threat categories based on percent change. ROC curves and PR curves were then used to test the effectiveness of the four models as classifiers. ROC curves indicated that the models performed well under most scenarios. However, the confusion matrices and PR curves revealed low precision values for all models. The high number of stocks falsely classified as threatened were masked in the ROC analysis by the imbalance of few threatened stocks compared to numerous non-threatened stocks. This is an important caveat, as it could lead to inappropriate threshold selection.

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

Self-Explanation and Self-Questioning Prompts in Online Medical Health Learning

Author: 
Date created: 
2017-04-13
Abstract: 

Online instruction in medical education is beneficial due to moves toward competency-based curricula, continuing education, serving professionals in remote locations, and knowledge updates as research advances. Those who study content online may require support to use effective methods that transform passive, less-engaged learning into active comprehension and purposeful application. This study compared two learning tactics: self-questioning and self-explanation that have not been compared in prior research. Health professionals and students across Canada studied a chapter in the Canadian Fundamentals of Fetal Health Surveillance (FHS) Self-Learning Online Manual, presented on an online learning management system. Participants used nStudy learning software to open note templates and type in either self-explanations or choose one among several question stems then fill in blank space(s) to create a question. Participants who created self-explanations performed better on the achievement posttest than those who generated self-questions. Further analyses disaggregated posttest items into intentional learning (relating to information in the text about which participants were prompted to generate an annotation) and incidental learning (relating to information in the text not directly prompted for annotation). Within the self-explanation condition, there was no statistically detectable difference in recall on intentional (prompted) content compared to incidental (non-prompted) content. In the self-questioning condition, incidental content was recalled similarly to the self-explanation group. However, there was a marked and statistically detectable decrease in recall of content about which participants were prompted to generate self-questions. Possible reasons for this effect based on past research and participant comments are discussed along with limitations of the study and opportunities for further research.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Philip Winne
Department: 
Education: Faculty of Education
Thesis type: 
(Thesis) M.A.

Modeling Canadian Federal Electoral Reforms

Author: 
Date created: 
2017-04-10
Abstract: 

This research project is focused on developing an exploratory model that can help explain the factors that affect the political desire for electoral reform. The model, premised on institutional and rational actor theories, develops a set of “endogenous” and “exogenous” factors that allow for evaluation of electoral reform discourse. While some attention is paid to the major reforms that the electoral system has undergone since Confederation, detailed analysis is reserved to the post-1980 period. Data was collected from party manifestos and Speeches from the Throne. Because the federal government has not made any structural changes to its electoral system, provincial and international electoral reforms are considered for the potential influence by “contagion”. Institutional barriers to reform are also factored into the model. Lastly, the model introduces the element of developing web-based technologies such as social media that are changing how the electorate is exerting its influence on the federal parties. From 1980 to 2015, what factors and influences, both endogenous and exogenous to Canada’s national political framework, have affected parliamentary debates on electoral reform?

Document type: 
Graduating extended essay / Research project
File(s): 
Senior supervisor: 
David Laycock
Department: 
Arts & Social Sciences: Department of Political Science
Thesis type: 
(Research Project) M.A.

Myosin Light Chain Phosphatase regulates the transcription of Wingless target genes in Drosophila

Date created: 
2017-03-28
Abstract: 

Canonical Wnt, or Wingless (Wg) in Drosophila, is an evolutionarily well-conserved signalling pathway that is important for a wide range of processes, including cell fate determination, axis formation and stem cell renewal. Wg signalling primarily functions to regulate the cytosolic stability of the key effector β-catenin (Armadillo, Arm, in Drosophila). Arm promotes the transcription of Wg target genes but also is required for the formation of stable adherens junctions. Previously, the Verheyen lab identified the non-muscle myosin II regulator Myosin Light Chain Phosphatase (MLCP) as a putative regulator of Wg signalling. Here we find that reducing the expression MLCP components leads to the attenuation of Wg target gene expression. I present our evidence that MLCP knock down directly regulates Wg signal transduction and that this regulation is through Arm localization. Thus, our work supports mounting evidence of a regulatory relationship between the adherens junctions and the Wg signalling pathway.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Esther Verheyen
Department: 
Science: Department of Molecular Biology and Biochemistry
Thesis type: 
(Thesis) M.Sc.

Relationships between STEM self-efficacy, same-sex role models and academic behaviour

Author: 
Date created: 
2017-04-11
Abstract: 

Although women make up approximately half of undergraduate enrolments in postsecondary educational institutions, women continue to be significantly underrepresented in many areas of science, technology, engineering and mathematics (STEM). In this study, survey responses from 249 undergraduate students enrolled in at least one STEM course were analyzed to further investigate possible relationships among sex, academic course choices, same-sex role models and STEM self-efficacy. Results show that female students were less likely than male students to declare a STEM major. Among female students there was a correlation between the number of same-sex instructors and being a STEM major as well as the number of STEM courses taken, and further investigation revealed that self-efficacy was a significant predictor of female undergraduate’s major. Implications, future directions and study limitations are discussed.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Phil Winne
Department: 
Education: Faculty of Education
Thesis type: 
(Thesis) M.A.

A novel colour Hessian and its applications

Author: 
Date created: 
2017-04-12
Abstract: 

The idea of contrast at a pixel, including contrast in colour or higher-dimensional image data, has traditionally been associated with the Structure Tensor, also named the di Zenzo matrix or Harris matrix. This 2×2 array encapsulates how colour-channel first-derivatives give rise to change in any spatial direction in x, y. The di Zenzo or Harris matrix Z has been put to use in several different applications. For one, the Spectral Edge method for image fusion uses Z for a putative colour image, along with the Z for higher-dimensional data, to produce an altered RGB image which properly has exactly the same Z as that of high-D data. As well, Z has been used as the foundation for the Harris interest-point or corner-point detector. However, a competing definition for Z is the 2 × 2 Hessian matrix, formed from second-derivative values rather than first derivatives. In this thesis we develop a novel Z which in the first place utilizes the Harris Z, but then goes on to modify Z by adding some information from the Hessian. Moreover, here we consider an extension to a Hessian for colour or higher-D image data which treats colour channels not as simply to be added, but in a colour formulation that generates the Hessian from a colour vector. For image fusion, results are shown to retain more details and also generate fused images that have smaller CIELAB errors from the original RGB. Using the new Z in corner-detection, the novel colour Hessian produces interest points that are more accurate, and as well generates fewer false positive points.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Mark Drew
Department: 
Applied Sciences: School of Computing Science
Thesis type: 
(Thesis) M.Sc.

HCN channel gating models: a re-evaluation based on how the voltage-sensing and cAMP-sensing domains regulate kinetics

Date created: 
2017-04-03
Abstract: 

Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels contribute to rhythmic oscillations in the heart and brain. Upon membrane hyperpolarization, HCN channel pore opening is coupled to inward movement of the S4 helix within the transmembrane voltage sensing domain (VSD, helices S1-S4). The gating pathway is proposed to include an initial voltage-dependent VSD movement step followed by a voltage-independent pore movement step (a cyclic allosteric mechanism). Various other mechanisms influence open state stability: A cytosolic cyclic nucleotide-binding (CNB) fold destabilizes the open state when unliganded (an autoinhibition mechanism), whereas binding of the phospholipid PIP2 to the transmembrane domain stabilizes the open state. After pore opening, the channel undergoes a mode-shift, presumed to include lateral movement of S4 towards S2, forming a more stable open state. Despite the knowledge of open state stabilization mechanisms, it remains unclear how these mechanisms affect the kinetics of the gating pathway. Do these mechanisms apply equally strongly to channel thermodynamics and kinetics? Do they apply under a variety of cellular conditions? And do they regulate the VSD movement step, the pore movement step, or both? In this work I examined both the thermodynamics and kinetics of the activation and deactivation pathways in a variety of HCN channel derivatives. I used two-electrode voltage clamp to determine that while channel thermodynamics follow the predictions of the autoinhibition model, a channel with an unliganded CNB fold has faster activation than a channel with autoinhibition relieved by CNB fold deletion. I propose this fast activation is promoted by a “quickening conformation” of the intact CNB fold. The quickening conformation is independent of PIP2 in both autoinhibited and autoinhibition-free channels. I used voltage clamp fluorometry to determine the speed of a VSD movement during channel deactivation in relation to pore closure. The speed of this VSD movement did not limit the rate of the deactivation pathway at strong depolarizations and showed stronger voltage dependence than pore closure. The speed of this VSD movement was independent of both cAMP binding and mode shift. Together my results clarify the HCN gating mechanisms of cyclic allostery, autoinhibition, PIP2 potentiation and mode shift, and produce novel models of both HCN channel activation and deactivation.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Edgar Young
Department: 
Science: Department of Molecular Biology and Biochemistry
Thesis type: 
(Thesis) Ph.D.

On the Neuro-Turn in Education: From Inside Out

Author: 
Date created: 
2017-03-30
Abstract: 

On the Neuro-Turn in Education gives a lived account of my exploration of quantitative research in education at the intersections of neuroscience, cognitive science, and cognitive psychology. I argue that existing quantitative studies fall short of meeting all (if any) of transdisciplinarity’s multiple dimensions, and I assert that such research is, in essence and methodology, an expression of the neuro-turn in education. This turn has reinforced a view of education, even if largely implicit, as a closed and mechanistic system—a perspective that so far has prevailed in our society over the view of education as a living process.I have met with transhumanists gravitating toward the outer edge of the neuroscience of learning, in the stratosphere of artificial intelligence, where the prospect of becoming smarter overshadows the wish to become wiser. In that respect, neuroethics - the most recent subdiscipline of applied ethics - rises from the paraxial fact that neurotechnologies are generating ethical challenges while at the same time promoting a neuroscientific understanding of ethics. I argue that ethical questions related to “my brain” are not distinct from ethical questions about “my self” in relation to others, a fact that a subdiscipline risks missing because it focuses on the particulars of the biological explanation of ethics, at the cost of the bigger picture: the complexity of the societal constructs involved in elaborating our moral judgments. I reclaim the richness of my embodied phenomenological being across an inside–out continuum from self to others, and from human to non-human others; and I explore intersubjectivity as resonance at both the philosophical and the organic levels. Finally, I reflect on how, as a philosopher of education, I can be an active participant in sharing with educators and all stakeholders a redefinition of the purpose and aims of education. Central to such dialogue is an urgent need to shed light on toxic metaphors that turn humans into data. By illuminating such issues, I hope to initiate our homecoming to a posthumanity embedded in the fabric of the world.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Heesoon Bai
Department: 
Education: Faculty of Education
Thesis type: 
(Thesis) Ph.D.