title: A 'Jaunt' Across the Pond: Investigating Patterns of Genetic Differentiation and Trans-Atlantic Migration in a Temperate Seabird (Morus Bassanus)

contributor:
Friesen, Vicki
Biology

subject:
Northern Gannet
Morus Bassanus
Outlier
Random Forest
Genetic Structure
Genetic Differentiation
ddRADseq
Seabird
Migration
Gene Flow
Divergence
Refugium
Genomics
High-Throughput Sequencing
Batch Effect
Last Glacial Maximum
Intrinsic Barriers
Extrinsic Barriers
Semi-Permeable Barrier
Trans-Atlantic
Fine-Scale Genetic Structure
Conservation
SNPs
Informative Loci
Population Assignment
Randomization

abstract:
Our understanding of the mechanisms driving population divergence is dependent on our ability to effectively detect and interpret patterns of genetic differentiation. In natural populations, the evolutionary processes influencing genetic differentiation can be difficult to ascertain. Seabirds are highly mobile, yet often display population differentiation, suggesting intrinsic barriers to gene flow are important in driving their diversification.

The northern gannet (Morus bassanus), a piscivorous, colonial seabird, is widely distributed across the North Atlantic Ocean. Despite strong dispersal abilities, decades of banding studies indicate that the North Atlantic Ocean acts as an effective barrier for migration in northern gannets. However, recent telemetry revealed that some northern gannets migrate across the ocean each year, suggesting trans-Atlantic gene flow is possible.

To investigate population differentiation in northern gannets, I analyzed genomic patterns of diversity among eight North American and European colonies. Genetic structure was characterized using indices of genetic differentiation, principal component analysis, a Bayesian clustering method, and discriminant analysis of principal components. I found significant population genetic structure across the breeding range, corresponding primarily to the division between North American and European gannet populations. My analyses did not find significant differentiation among colonies on either side of the Atlantic.

I employed Bayesian approaches to estimate contemporary gene flow and divergence between North American and European gannet populations. I found low but significant rates of migration from Europe into North America, but no migration from North America into Europe. My analyses suggest that North American and European populations diverged recently, potentially occupying separate refugia during the Last Glacial Maximum. Finally, I used outlier analysis and random forest feature selection to investigate fine-scale genetic structure, and identified loci that allowed population assignment of 85% of sampled northern gannets.

Low genetic differentiation in northern gannets may be due to shared variation following recent range expansion or to admixture resulting from overlap in nonbreeding distribution. My results suggest that the North Atlantic Ocean acts as a semi-permeable barrier to gene flow in northern gannets. The informative genetic markers I identified may allow colony-specific impact assessment and the development of targeted management strategies in northern gannets.

abstract: M.Sc.


contributor:
von Hlatky, Stéfanie
Political Studies

rights: Queen's University's Thesis/Dissertation Non-Exclusive License for Deposit to QSpace and Library and Archives Canada

rights: ProQuest PhD and Master's Theses International Dissemination Agreement

rights: Intellectual Property Guidelines at Queen's University

rights: This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner.

subject:
International Organizations
War
Cooperation
Anarchy
Afghanistan
Iraq
Libya
NATO
UN
EU
International Staff
Secretariat

abstract: Why Organizations Fight: Wars of Choice in an Age of Instability examines the participation of three international organizations, the United Nations, the North Atlantic Treaty Organization, and the European Union, across three wars: The War in Afghanistan, the War in Libya, and the War in Iraq. Each of these organizations have, as their mandate, crisis management and crisis response. As such, states have a number of organizational frameworks that they can select from. However, given the overlap in mandates, the organization that is chosen to lead is not necessarily a given. When an organization is selected by a state, or group of states, for a mission, that organization may find itself in a conflict zone that falls far beyond its initial scope and mandate. How did it come to be, for example, that NATO, a regional collective defence organization, would find itself fighting an insurgency in Afghanistan? Why, in spite of strong member-state preferences for an EU-led response in Libya, was NATO given the lead? And why did the United States, the preeminent military power, go to such lengths to try and secure a United Nations Security Council mandate for actions against Iraq? In asking these three questions, this dissertation is based on a much broader question: How are the roles of international organizations negotiated in large-scale international conflict? This dissertation argues that international organizations play an active role in shaping policy and outcomes on the battlefield. Although one may expect organizations to represent the interests of their membership, this is not always the case. Driven by their interest in survival, organizations must continuously demonstrate both material and political relevance. But demonstrating relevance is not always a straightforward process. Ensuring the survival of an organization requires navigating a complex security environment with a multiplicity of competing, and sometimes contradictory, interests.

abstract: PhD


title: The Social Practice of Crafting: Gender, Class, and Race in Western Craft

contributor:
Helland, Janice
Alfoldy, Sandra
Art History

subject: Craft

subject: Amateur Craft

subject: Domestic Craft

subject: Feminism

subject: Women's Culture

subject: Women's Creativity

subject: Craft History

subject: Art History

subject: Feminist Art

subject: Canadian Settler Colonialism

subject: Domesticity

subject: Leisure

subject: Women's Labour

subject: Craftivism

subject: 19th Century Material Culture

subject: 19th Century Settler Colonialism in British Columbia

subject: O'Keefe Ranch

subject: Critique of White Moralism in Contemporary Social Justice Activism

subject: Critique of 'Personal is Political' in Feminism

subject: Critique of White Moralism in Craftivism

abstract:
This study provides an analysis of Western amateur crafting as a social practice that is informed by a complex matrix of historical, social, cultural, ideological, and economic influences. A historical overview of amateur craft culture establishes how it became a practice that was axiomatic with middle-class femininity and domesticity beginning in the late-eighteenth century. A case study expands on this assessment, and situates the handicrafted material culture of the O’Keefe women – members of one of the first Anglo-Canadian families that settled in the interior of British Columbia in the 1870s – as an example of how amateur crafting, through imperial and colonial processes, became a racializing directive that marked and imposed social boundaries within Canadian settler-colonial society. The historical overview and the case study outlines amateur craft’s genealogy, which provides an understanding of how its ideological and symbolic associations with femininity, middle-class status, and whiteness frame contemporary amateur craft culture and practices. The thesis interrogates these symbolic associations which remain at the heart of contemporary craft culture and discourse through an examination of the white moralism of craftivism, a form of lifestyle activism popular among white, middle-class women where domestic crafts are utilized in service of a public expression of protest and dissent.

The thesis employs a queer feminist methodology to support the investigation of amateur craft as a social practice that is inherited as a direction that keeps or places the maker in line. This methodology draws the various contexts of a person’s existence into direct consideration – how they inhabit their body and negotiate social constructs such as race and gender; the straight or queer orientation of their desire; and the meanings ascribed to the body’s size, and shape, and ability. These aspects play an integral part in determining if craft is in line with that person’s direction. This project presents an analysis of how some people are oriented toward certain forms of amateur domestic crafting based on their positionality as feminine, white, and middle-class, and how amateur domestic crafting as a practice imbued with symbolic and ideological associations with whiteness, femininity, and gentility, receives and returns this direction.

abstract: PhD


title: Effect of Oncogenes Upon the Signal Transducer and Activator of Transcription-3 (Stat3) and the Dominant-Negative Isoform Stat3β

contributor:
Raptis, Leda
Biomedical and Molecular Sciences

subject:
Stat3
Stat3β
Cell Density
Simian Virus 40 Large Tumour antigen
Oncogenes
Alternative Splicing

abstract:
Stat3 is activated by cytokine receptors and non-receptor kinases and plays an etiological role in neoplasia. Stat3 activation entails phosphorylation at the tyrosine 705 residue (Y705), dimerization through a reciprocal SH2 domain-phosphotyrosine interactions, and nuclear translocation. This cascade triggers transcription of genes involved primarily in survival. Our lab recently demonstrated that engagement of cadherins, cell-cell adhesion molecules, triggers a dramatic increase in Stat3 activity, through Rac/Cdc42, IL6 and Jak.
Full-length Stat3, termed Stat3α, has an SH2 domain, Y705 residue, and a COOH terminus containing the transcription activation domain (TAD). Stat3β is a naturally-occurring splice variant lacking the TAD. Therefore, Stat3β is defective in transcriptional activation, and competitively inhibits Stat3α signaling.
Given the sequence identity around the critical Y705 in Stat3α and Stat3β, we initially set out to examine the phosphorylation pattern of the two isoforms in cells expressing two representative oncogenes, Simian Virus 40 Large Tumor antigen (SVLT) or activated Src (vSrc). My results demonstrate that extensive cell-cell adhesion brought about by cultured cell confluence results in phosphorylation of Stat3α preferentially. On the other hand, SVLT and vSrc expression result in a preferential phosphorylation of Stat3β, although to a much lesser extent by vSrc. The increase in Stat3β phosphorylation by SVLT could be attributed, in part, to an increase in total Stat3β protein levels, brought about through an increase in the levels of the adenine deaminase acting on RNA-1 (ADAR1). In addition, β-pY705-Stat3 turnover is much slower than that of α-pY705- Stat3, leading to accumulation and increased detection.
In any event, this increase β-pY705-Stat3 that reduces the activity of Stat3α inhibits transformation by SVLT and triggers apoptosis in transformed cells. Therefore, Stat3β is a naturally occurring variant which is able to curb transformation by oncogenes that require Stat3 function as part of their mechanism of action, a finding which could have important implications in cancer therapy.

abstract: M.Sc.


title: Supporting Post-Secondary Educational Data Usage in the Assessment Process with Information Visualization

contributor:
Frank, Brian
Electrical and Computer Engineering

subject:
Assessment Data
Information Visualization
Higher Education
Program Improvement

abstract:
Programs, institutions, and governments are increasingly looking at data about student learning for both accountability and program improvement activities. Faculties at post-secondary institutions have employed systems to gather vast amounts of assessment data in recent years with the ultimate goal of using the data to improve the student learning experience. Unfortunately, faculty members responsible for this data are unfamiliar with analyzing data sets of this magnitude or complexity and therefore cannot extract actionable insight from the data to inform their program improvement decisions. Approaches to support this process are still developing, referred to largely as Educational Data Mining. Information Visualization is one technique that has shown promise in facilitating the extraction of meaningful information, though there has been little research conducted into where and how visualizations are utilised at a post-secondary level. The ultimate goal of this research is to build a support that encourages the usage of educational data through visualizations. To build one that is effective, a research study was conducted to discover the factors surrounding how educational data was used in this setting.
The research was a three-phase qualitative study aimed at determining the attitudes around data usage as well as what aspects of assessment data usage are currently challenging education staff and faculty members in achieving their program improvement goals. The study included interviews, a focus group, and an open-response survey created using an emergent design methodology. Participants were from institutions in Canada, focused largely at Queen’s University. The outcome of the research findings was a model of four major stakeholders in the process of educational data usage and some of the important factors that surround the usage and the interaction between stakeholders. The resulting support tool built from this research aims to support those interactions and specifically identified challenges by bringing the principles from the broader field of information visualization into an accessible form for staff and faculty at post-secondary institutions trying to work with educational data.

abstract: M.A.Sc.


title: Parallel Divergence by Allochrony and Cryptic Speciation in two Highly Pelagic Seabird Species Complexes (Hydrobates spp.)

contributor:
Friesen, Vicki
Lougheed, Stephen
Biology

rights: Attribution-NonCommercial-NoDerivs 3.0 United States

subject:
Speciation
Cryptic Species
Allochronic Speciation
Storm-Petrel

abstract: Sympatric speciation, the evolution of reproductive isolation between populations without physical barriers to dispersal, is less likely than allopatric speciation due to the need to overcome potentially homogenizing gene flow. Cryptic species - two or more species mistakenly classified as one usually due to morphological similarity - can form in allopatry or sympatry. One potential mechanism of cryptic speciation in sympatry is allochronic speciation, i.e. divergence driven by differences in breeding time. In this thesis, I first collated examples where allochrony caused divergence between populations to glean new insights into drivers of shifts in breeding time across taxonomic groups and the genetic underpinnings involved, and to create a framework for future investigations. Using both genetic and genome-wide sequencing techniques, I then investigated drivers of cryptic divergence and the evolution of allochronic populations across the global breeding ranges of two cryptic seabird species complexes, Leach’s and band-rumped storm-petrels (Hydrobates spp.). In Leach’s storm-petrels, I found non-physical barriers to be stronger drivers of divergence than physical ones, with some genetic differentiation between ocean basins but higher differentiation among colonies in the Pacific Ocean. Phylogenetic reconstruction revealed that Guadalupe seasonal populations likely speciated allochronically. In band-rumped storm-petrels, colonies in different ocean basins were genetically differentiated, however phylogenomic reconstruction placed South Atlantic colonies as sister to Pacific colonies, and revealed strong genetic structuring within ocean basins, again suggesting non-physical barriers as drivers of divergence. Band-rumped storm-petrels consist of seven reciprocally monophyletic groups, and thus likely represent up to seven different species. I then investigated whether allochronic populations of band-rumped storm-petrel formed due to a mutation shifting breeding time in a founder event, standing genetic variation at the population level, or plasticity in breeding time. My findings indicate breeding season changes are unlikely to have involved a mutation and founder event, however further work is needed to tease apart the potential roles of standing variation and plasticity. Altogether, this thesis reveals the importance of non-physical barriers to gene flow in Leach’s and band-rumped storm-petrels, uncovers cryptic species needing taxonomic and conservation consideration, and furthers our knowledge of allochronic divergence, an underappreciated mechanism of cryptic diversification.

abstract: PhD


title: Geometallurgical and Geological Evaluation of the High-Grade Polymetallic Unconformity-Related Cigar Lake Uranium Deposit

contributor: Geological Sciences and Geological Engineering

subject:
Geometallurgy
Geology
Geochemistry
Cigar Lake
Uranium

abstract:
The high-grade, polymetallic, unconformity-related, Cigar Lake uranium deposit, located in northern Saskatchewan, Canada, is the focus of a detailed mineralogical, geochemical and geospatial study aimed at geometallurgical characterization and reconstruction of its underlying geological history. The main mineralization event occurred before 1468±93 Ma and was likely syngenetic with the basin wide (ca. 1590 Ma) U mineralization event. Uraninite co-precipitated with common Pb-bearing arsenides, sulpharsenides and sulphides. Molybdenum was mobile during primary mineralization, crystallizing within Stage 1 uraninite. Relatively high and consistent δ34S values up to 14.6‰ indicate a significant basinal and marine SO42- contribution and an open-system with a well-mixed source. Low 207Pb/206Pb values (0.56–0.86) is imprinted on co-precipitated chalcopyrite, spatially and texturally associated with Stage 1 uraninite, suggesting that the U and Cu were sourced from Archean minerals. Syn-ore calcite equilibrated with a fluid having high δ18O values between +1.8 to +7.2‰, typical of diagenetic basinal brine in the Athabasca Basin, and low δ13C values ranging from -22.4 to -21.8‰, consistent with a source from underlying graphite.
	Stage 2 fluid incursion, constrained by U/Pb dates at 1270-1163 Ma resulted in crystallization, recrystallization and Pb absorption forming radiogenic (206Pb/204Pb ~1000) and selenite-bearing sulphides and sulpharsenides concurrent with enhanced clay alteration. Stage 3 alteration, with U/Pb and Pb/Pb dates between 947-755 Ma was responsible for extensive hematization and crystallization of anomalously radiogenic (206Pb/204Pb ~3000–20,000) bornite, chalcocite and galena. The most recent deposit alteration event, stage 4 (242-0 Ma), manifests as extensive coffinitization and re-mobilization of U as perched mineralization. The paragenetic stages coincide with major, far-field tectonic and regional geological events: (1) Stage 2 with the Grenville Orogeny, the Mackenzie dyke swarm and the Moore Lake olivine diabase, (2) Stage 3 with the breakup of the supercontinent Rodinia, and (3) Stage 4 with recent meteoric and glacial meltwaters.
The paragenesis, geochronology and stable isotopes reveal a protracted history, with ongoing episodic fluid incursion, driven by far-field tectonics that resulted in alteration and re-mobilization of selected elements. Using the geometallurgical paradigm presented here, the geology at Cigar Lake can be used to optimize and reduce risk during long-term mine and mill planning.

abstract: M.Sc.


title: Elucidation of the Roles and Functional Implications of the RET Receptor Tyrosine Kinase in Cancer

contributor:
Mulligan, Lois
Pathology and Molecular Medicine

subject: RET cancer

abstract: RET is a receptor tyrosine kinase that plays important roles in normal development of the kidney, spermatogonia, and neuroendocrine tissues. RET is also implicated in various diseases, including tumors of the breast, prostate and thyroid. Normally, RET is activated through the formation of a tri-molecular complex involving its co-receptor, GFRα1, and its ligand, GDNF. The formation of this tri-molecular complex leads to the activation of many signaling pathways that induce cellular processes such as cell survival, differentiation and proliferation. RET is expressed in approximately 30-70% breast cancer cases. While initial work suggested that RET was associated with luminal forms of breast cancer, more recent data suggest that this receptor tyrosine kinase may be more broadly implicated with multiple subtypes of breast cancer.  Here, we  used in vitro cell-based models to further investigate the role of RET in breast cancer. Through our analysis, we found five RET-positive breast cancer cell lines, and confirmed the suitability of these models to explore the role of RET in breast cancer. Further, our data suggest that RET activation through GDNF treatment increases proliferation of most of these breast cancer cells. In a high throughput screen using a protein domain microarray dataset, a potential interaction between RET and the BCAR3 adaptor protein was previously identified. To gain a more mechanistic understanding of RET’s contribution to cancer, we characterized and explored the functional implications of RET’s interaction with the adaptor protein, BCAR3. Here, we confirm that RET and BCAR3 interact, and that it is a direct interaction between the SH2 domain of BCAR3 and RET. As we were not able to identify in our studies a suitable breast cancer cell model in which RET and BCAR3 were co-expressed, we used SH-SY5Y neuroblastoma cells, a cell line that co-expresses RET and BCAR3, for our functional analyses. Our data suggest that BCAR3 knockdown in SH-SY5Y neuroblastoma cells has a broad role in proliferation and adhesion, independent of RET.  Further research is required to fully elucidate the functional relevance of the RET-BCAR3 association.

abstract: PhD


title: Laboratory Strength Testing of Argillaceous Limestone Under Varying Saturation, Scale, Loading Rate, and Confinement Conditions

subject:
Cobourg Limestone
Crack Initiation
Crack Damage
Uniaxial Compressive Strength
Brazilian Tensile Strength
Triaxial Strength
Saturation Effect
Scale Effect
Loading Rate Effect
Confinement Dependency
Experimental Testing Methodology

abstract:
The Deep Geological Repository (DGR) concept is the proposed solution for the long-term storage of nuclear waste in Canada. While site selection processes are currently underway for high-level waste storage, a low and intermediate waste storage DGR is planned for development at depth in Kincardine, Ontario. The DGR site is to be hosted in the Cobourg limestone, a rock formation which presents varying heterogeneity at different scales. The successful design of long-term nuclear waste storage requires engineered barriers and geology designed to safely and securely contain contaminants. The excavation of hard rocks at depth can induce damage to the surrounding rock mass. This damage corresponds to the initiation and propagation of fractures and is related to in situ stress conditions and excavation processes. Heterogeneous rock masses can further complicate the initiation and propagation of fractures, causing inconsistent behaviour related to the variability of the rock. The changing in situ conditions of DGR host rocks can also influence fracture behaviour, highlighting the need for a better understanding of the effect of rock conditions on the damage behaviour of brittle rocks.
	This research examines the influences of various testing conditions on the geomechanical properties of Cobourg limestone, to address the changing in situ conditions that may be present during long-term storage of nuclear waste. The effects of specimen saturation, scale, loading rate, and confinement have been investigated through the laboratory strength testing of specimens representative of Cobourg limestone found at depth for the proposed low and intermediate level DGR site. Using standardized laboratory testing practices and newly developed experimental methodologies, this thesis describes the influences of testing condition on the elastic and strength properties of the rock. The testing methodology is presented and examined to evaluate the effectiveness of the different testing conditions in properly characterizing the Cobourg limestone. The observations and results from this work provide details regarding the physical properties and failure behaviour of the rock, as well as non-standard testing techniques for investigating heterogeneous rock masses. This research provides insight into the characterization of brittle rock failure under different testing conditions, which is important for future DGR site selection.

abstract: M.A.Sc.


title: Modification of Poly(methyl methacrylate) Surfaces with Azobenzene Groups to Develop a Photoresponsive Surface

contributor:
Wells, Laura
Chemical Engineering

subject:
Surface Modification
Photoresponsive
Azobenzene

abstract:
Photoswitchable surfaces can be used to reversibly control surface wettability, adsorptivity, and protein adhesion to influence cell interactions at the surface. Control over protein adsorption and cell adhesion is useful in many applications, from cell culture scaffolds to drug delivery devices and improving the cell response to materials in vivo. Switchable properties can be attained by polymerizing light-responsive monomers or by modifying existing materials. This project investigates surface modification as a method of developing light-responsive poly(methyl methacrylate) (PMMA) surfaces and coatings of a copolymer of methyl methacrylate (MMA) and 2-aminoethyl methacrylate (AEM) (termed MMAcoAEM).

In this work, PMMA surfaces were functionalized with amine or carboxyl groups for azobenzene modification and cell-material interaction studies. PMMA was functionalized with hexamethylenediamine (HMD) or O,O'-bis(2-aminopropyl) propylene glycol-block-polyethylene glycol-block-polypropylene glycol (PPG-PEG-PPG) groups via aminolysis or functionalized with carboxyl groups via hydrolysis. Aminated PMMA was then modified with 4-(phenylazo)benzoic acid using a carbodiimide reaction. Surfaces were characterized using ninhydrin assays, titration, contact angle measurements, x-ray photoelectron spectroscopy (XPS), ultraviolet-visible (UV-VIS) spectroscopy and nuclear magnetic resonance spectroscopy (NMR).

The aminolysis reaction conditions from literature1 were revised to improve the graft density, with up to 36.4 ± 7.0 nmol/cm2 of HMD or 20.3 ± 2.9 nmol/cm2 of PPG-PEG-PPG groups functionalized to PMMA. The copolymer MMAcoAEM contained 44.0 ± 2.2 nmol/cm2 of amine groups as a surface coating. Amine-functionalized PMMA or MMAcoAEM surfaces were modified with 20.5 ± 0.4 nmol/cm2 (HMD), 11.2 ± 2.6 nmol/cm2 (PPG-PEG-PPG), or 24.8 ± 4.4 nmol/cm2 (MMAcoAEM) of 4-(phenylazo)benzoic acid. UV-VIS spectroscopy was used to confirm that azobenzene grafted to materials retained the ability to photoisomerize and interact with β-cyclodextrin (β-CD).

Functionalized PMMA was also used to study cell-material interactions with neutrophil-like HL-60 human promyelocytic leukemia cells activated with phorbol 12-myristate 13-acetate (PMA) to induce cell adhesion. AlamarBlue® assays and live/dead deoxyribonucleic acid (DNA) staining indicated that amine-modified surfaces contained the highest amount of extracellular DNA after incubation with HL-60s, believed to be extracellular traps (ETs). Future research aims to study the cell-material interactions with azobenzene-modified surfaces and further modify the surface using biomolecules conjugated to β-CD.

abstract: M.A.Sc.


title: Nanoelectromechanical Studies of Suspended Resonators using Graphene grown by Chemical Vapour Deposition

contributor: Physics, Engineering Physics and Astronomy

subject:
Physics
Nanomechanics
Nanofabrication
Graphene Mechanical Resonators
Chemical Vapor Deposition
Nonlinear Dynamics
Duffing Resonator
Parametric Amplification

abstract: Graphene is an ideal material for high quality nanoelectromechanical resonators due to its high Young's modulus, low mass to surface ratio, ability to sustain high in-plane strain, and unique electrical properties like high carrier mobility, ballistic transport and nonlinear modulation of conductance under the electric field effect. In this work, atmospheric pressure chemical vapour deposition (CVD) is employed to obtain monolayer graphene on copper. The effect of growth parameters such as gas concentration, growth temperature and growth time are studied and optimized such that predominantly monolayer graphene is obtained. Scanning electron microscopy and Raman analysis reveal the presence of high quality, monolayer graphene. The graphene is transferred to Si/SiO_{2} wafers and multiple step electron beam lithography, metal deposition, substrate etching, and critical point drying are used to fabricate suspended graphene doubly-clamped resonators. The present fabrication technique, thus combines top-down and bottom-up fabrication method and presents an important work in the development of batch-processing of large area graphene towards future industrial applications. Modeling the suspended devices as Duffing resonators near their fundamental flexural mode shows the presence of mechanical nonlinearity in response to an applied force even at moderate bias voltages. We discuss the implications of this nonlinearity for parametric amplification. Interesting parametric responses such as gain saturation and presence of multistability are obtained as a result of the complex interplay between the mechanical nonlinearities in graphene suspended resonators. As a final step, a measurement system is developed to electrostatically actuate the suspended devices and read out the motion using nonlinear mixing of graphene's electrical conductivity. The electromechanical data for one such device is analyzed to quantify the resonant frequency and quality factors of three detectable modes. Experimental data for resonance and frequency tunability of the fundamental mode illustrates the presence of mass loading and initial strain in the suspended device. The present work combining the fabrication, modeling and electromechanical measurements are important steps for the prospects of developing measurement techniques for future sensors and quantum-limited mechanical measurements of CVD-grown graphene.

abstract: PhD


title: Systemic Vascular Dysfunction in Patients with Mild Chronic Obstructive Pulmonary Disease

contributor:
Neder, J Alberto
Fisher, John
Biomedical and Molecular Sciences

rights: Attribution-NonCommercial 3.0 United States

subject:
COPD
Cardiovascular Disease
Mild
Arterial Stiffness
Endothelial Dysfunction

abstract:
Background: Chronic obstructive pulmonary disease (COPD) is associated with an increased risk of cardiovascular disease, a finding that might be mechanistically linked to systemic vascular abnormalities. In fact, coexistent cardiovascular disease is a major cause of disability and death in COPD patients with only mild airflow obstruction. It remains unknown however whether these patients may present with systemic vascular dysfunction. Moreover, it remains unclear whether specific lung structural abnormalities (i.e., emphysema versus airway disease) would be associated with greater systemic vascular dysfunction. We hypothesized that patients with mild COPD, particularly those with larger emphysema burden, would present with abnormalities in systemic vascular function compared to controls.
Methods: In an observational and prospective study, we measured central and peripheral pulse wave velocity (PWV), flow mediated dilation (FMD) of the brachial artery, systemic levels of plasma interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF) in 16 COPD patients (FEV1=8613 % predicted) and 16 age- and gender-matched sedentary controls. Emphysema and airway disease burden were quantified by chest computed tomography in patients.
Results: Patients and controls were well-matched by comorbidities burden, including cardiovascular disease. Patients presented with greater central aortic stiffness (aPWV=9.571.39m/s versus 7.741.30m/s; p=0.002) but preserved peripheral arterial compliance (p =0.43) compared to controls. Patients had impaired shear rate-corrected FMD (- 1.86-fold; p=0.03) and delayed maximum vasodilatory response (-16.5 s; p<0.01). Emphysema extent (but not airway disease) and lung transfer factor for carbon monoxide (DLCO) were significantly related to higher central arterial stiffness and both impaired and slowed flow-mediated dilation of the brachial artery (r values ranging from 0.50 to 0.66; p<0.05).
Conclusion: Systemic vascular dysfunction is present in patients with mild COPD, particularly in patients with greater emphysema burden and low DLCO. These patients might be at higher risk of negative cardiovascular events thereby deserving more detailed screening and closer longitudinal follow-up.

abstract: M.Sc.


title: Towards a Cognitive Poetics of Puppetry

contributor:
Rewa, Natalie
Morehead, Alison
Kuhlmeier, Valerie
Cultural Studies

subject:
Puppetry
Performance
Cognitive Poetics
Cognitive Sciences
Performing Arts
Practice-Led Research
Auto-Ethnography
Trans-Disciplinary
Uncanny Valley
Animacy Perception
Agency
Tinbergen

abstract: Spectators routinely ascribe intention, personality, even an inner life to inanimate, contingently moving objects like puppets. Why do spectators do so? The prevailing semiotic approach is unable to bring light into this fundamental perceptual issue of puppetry. On the other hand, phenomenology and cognitive psychology are shown to be productive when it comes to tackling questions of the perceptual processes involved in contemporary puppetry. A bird’s eye view on the research areas that involve puppetry is proposed and a modified Tinbergian framework, which originates in ethology, is suggested. The research question is then situated within this framework. An overview of the scholarly works relating to puppets and the apparent missed connections between them underscores the need for a unifying framework. Detailed descriptions acquaint the reader with current works in puppetry. The works emphasize the need for tools that go beyond traditional semiotics for analyses of today’s puppetry arts. By applying a perceptual analysis, a cognitive poetics of puppetry is outlined. The assumptions of this cognitive poetics are tested against a first-hand experiential/experimental foray into the practice of puppetry. This thesis thus contributes to the emerging field of studies in puppetry arts in a threefold way: outlining the need for going beyond semiotics, suggesting a productive framework for the organization of the field, and developing a cognitive poetics approach within this newly defined framework to answer the question “How does it work?”

abstract: PhD


title: Health Inequalities of Older People in China

contributor:
Rosenberg, Mark
Geography and Planning

subject: Health inequalities, older people, China

abstract:
China is facing serious population aging issues because of unintended consequences of the economic reforms and social policies which began in the 1980s. Despite the remarkable progress in health status (e.g., the increasing life expectancy) in China, there remain large inequalities not only across the country, but also at a micro geographic scale. Health inequalities can be attributed to biological variations but also other variables including demographic socioeconomic and environmental indicators.

Research on health inequalities in western countries is robust. However, there are few comprehensive studies of health inequalities in China. This research analyses the patterns of health inequalities and the associated social determinants of health with a specific focus on Chinese older people. Mixed methods are employed to garner a nuanced perspective on health inequalities and the social determinants of health. Data are extracted from both statistical surveys and semi-structure interviews. Quantitative methods are used to analyse the relationships between health inequalities and social determinants of health at various geographic scales. An analysis of semi-structured interviews is used to inform the quantitative finding providing further depth to an understanding of health inequalities among older people living in China.

Several major findings result from this research. The population aging process has a significant influence on health inequalities for older people. China exhibits a significant rural-urban developmental divide with a noticeable impact on health inequalities. Socio-economic changes have significant impacts on health inequalities in China. The relationship between better socio-economic status and better health status is similar to but different than what is found in research in developed countries because of the various types of pensions. Compared to traditional environmental factors, the built environment in which older people live plays a significant role in determining health inequalities.

To sum up, a comprehensive health care system is required in order to meet sustainable development and to narrow health inequalities in China. Socio-economic, environmental and other factors make significant contributions to determine older people’s health outcomes. As China is undergoing top-down social reform, health inequalities are widening. Promoting balance among different groups of older people is a principal challenge for Chinese society.

abstract: PhD


title: 3D Object Recognition and Registration Using Minimalist Descriptors

contributor:
Greenspan, Michael
Marshall, Joshua
Electrical and Computer Engineering

subject:
Computer Vision
Pattern Recognition
Object Recognition
Registration
3D Range Image Processing

abstract: This thesis presents a novel minimalist descriptor for 3D object recognition and registration problems called 3DLD (3D line descriptors). Building off of previous work on multiple point descriptors, this thesis introduces the first descriptor to apply lines to both of these problems. Each 3DLD is based on the depth information obtained between two 3D points. An efficient indexing scheme using multiple hash maps is introduced to efficiently retrieve the descriptors. From experimentation, 3DLD are very effective in both registration and recognition problems - achieving near perfect true positive rates in many of the tests. Particularly, on complex data, with cluttered and occluded scenes, 3DLD can provide superior efficiency.

abstract: M.A.Sc.


title: Natural Selection on Phenology Across an Elevational  Gradient in Seasonality

contributor:
Eckert, Christopher
Biology

subject:
Natural Selection
Phenology
Adaptation
Plant Biology
Trade-Offs

abstract:
Many populations are locally adapted to their environment, but across an environmental gradient, trade-offs among phenotypic traits may result in a failure to adapt. Species exist across a seasonal gradient, which can create selection for phenology, the timing of key life history events. Flowering phenology is important because flowering late exposes the plants to abiotic risks, like frost damage, whereas flowering early can lower fecundity if there is a trade-off between time to and size at flowering. This trade-off should result in different patterns of selection across a seasonal gradient, with stabilizing selection favouring intermediate flowering in long growing seasons, and selection favouring early flowering in short growing seasons. While this theory is well established, few studies have measured selection on flowering phenology across a seasonal gradient in natural populations.
	In 2015 and 2016, I measured selection on the time to and size at flowering from 12 populations (24 site × year combinations) of the annual herb Rhinanthus minor (yellow rattle), across an elevational gradient of 900m, in the Rocky Mountains of Alberta, Canada. For each site × year I quantified the growing season length measured using cumulative growing degree days (CGDD).

	I predicted that 1) CGDD would vary linearly with elevation, 2) There would be selection favouring early flowering in sites with low CGDD, 3) There would be stabilizing selection for intermediate flowering in sites with moderate and high CGDD, 4) There would be a trade-off between time to and size at flowering.

	Contrary to my predictions I found that 1) CGDD varied quadratically with elevation, as low and mid elevational sites had similar CGDD, 2) Selection favoured early flowering plants across the gradient in season length, 3) There was no stabilizing selection for flowering time, 4) There was no evidence of a trade-off between time to and size at flowering.

	There was no evidence for a trade-off, therefore earlier flowering plants were able to flower both early and at a larger size, resulting in higher fitness. My results challenge commonly held life history assumptions and demonstrate the importance of foundational research in natural systems.

abstract: M.Sc.


title: Physical Activity, Sedentary Time, Sleep Duration, and Self-Rated Health in Older Adults: A Compositional Analysis

contributor:
Rosenberg, Mark
Aronson, Kristan
Public Health Sciences

subject:
Physical Activity
Epidemiology
Compositional Analysis
Self-Rated Health

abstract:
Purpose: The purpose of this study was to determine the relationship between movement behaviours that make up a day and self-rated health (SRH) in adults aged 60-79, while adjusting for time spent in all other behaviours. This required the application of a compositional data framework to the analysis, which is an emerging method in physical activity epidemiology.
Methods: This study was conducted using cycles 1-3 of the Canadian Health Measures Survey. SRH, sleep duration, and covariates were self-reported, and sedentary time (ST), light-intensity physical activity (LIPA), and moderate-to-vigorous intensity physical activity (MVPA) were measured using an Actical accelerometer. Traditional descriptive statistics were computed for the outcome and covariates, while compositional descriptive statistics were displayed for the movement behaviours. Logistic regression analyses were run to determine the association between the overall composition of movement behaviours and SRH, as well as the association between each movement behaviour and SRH. The odds of reporting ‘poor’ or ‘fair’ SRH were modeled.
Results: The distribution of time spent in sleep, ST, LIPA, and MVPA is associated with SRH (p<0.001). Relative to the other movement behaviours, both sleep duration (OR= 0.17) and MVPA (OR=0.81) were associated with better SRH. ST was associated with poorer SRH (OR=12.4). No statistically significant association was found for LIPA.
Conclusion: SRH in older adults was positively associated with sleep duration and MVPA, and negatively associated with ST. Future research on physical activity should consider the effects of each movement behaviour on health outcomes, while taking into account the other behaviours.

abstract: M.Sc.


title: Determining the Mechanisms of Subsidence at a Dewatered Carlin Trend Underground Mine using Numerical Modeling Methods

contributor:
McKinnon, Stephen
Kalenchuk, Katherine
Mining Engineering

subject:
Subsidence
Carlin Trend
Underground Mining
Mine Dewatering
Aquifer Deformation
Numerical Modeling

abstract:
Subsidence can be produced by multiple types of subsurface ground behavior, and is a potential concern in a mining environment due to the impacts this behavior can have on underground excavations. Subsidence was detected by InSAR methods in the region of the Leeville underground mining complex between 2004 and 2015. The Leeville operations are located on the Carlin Trend in northern Nevada, include extraction of multiple tabular orebodies, and primarily utilize longhole stoping methods with backfill. The measured subsidence forms an irregular shaped pattern that is much broader than the underground footprint of mining, with a trough that experiences higher displacements located over a mined-out area.
The subsidence mechanism was investigated because it was unclear whether the subsidence was caused by mine dewatering or underground mining. Geologic, groundwater, and extraction data were reviewed to form hypotheses of the causes and controls of subsidence, which were then tested in a 3-D geomechanical model. A method to numerically simulate subsidence due to the coupled effects of underground mining and dewatering was developed, which involved starting with very simple elastic models, testing each mechanism or control incrementally, and eventually building in the appropriate mechanisms and controls into the model. The InSAR data was used as the main calibration dataset.
The main findings of this thesis include: subsidence in the Leeville area is likely the result of two mechanisms, mining-induced deformations and compaction in the deep carbonate aquifer; geologic factors, such as low permeability features and hydrothermally altered/fractured zones, form controls on the subsidence pattern; and that yielding of the rock mass is likely producing higher strain magnitudes over stoping. This thesis has implications for understanding ground behavior and mine design at the Leeville operations and other underground Carlin Trend mines.

abstract: M.A.Sc.


title: Probing The Link Between Indolent Aneurysm Dome Infection And Brain Aneurysm Growth And Rupture.

contributor:
Cook, Douglas
Neuroscience Studies

subject: Microbiology Aneurysm Inflammation

abstract:
Background: Vascular inflammation and immune activation play important roles in intracranial aneurysm (IA) pathology. From mycotic aneurysms it is apparent that fulminant microbial infection can drive aneurysm formation and rupture. Recently microbial DNA has also been discovered in aneurysm domes with no clinical signs of infection. This suggests that low level microbial infections may also influence aneurysm pathology. However, more comprehensive analyses are required to test this hypothesis. To this end, we explored the possibility that IA progression is related to indolent, subclinical infection of the aneurysm dome by microorganisms originating from commensal or pathogenic populations existing elsewhere in the host.
Methods: IA dome samples originating from one of three patient populations (stable, growing or ruptured IAs) were collected along with controls from patients undergoing IA clipping surgeries. DNA was extracted from each sample for 16S rRNA analysis using Illumina MySeq. Microbial populations in each sample were identified and analyzed to determine differences microbial populations between IA pathologies.
Results and Discussion: 84 different operational taxonomic units were identified in patient samples, with 19 found only in IA tissues. No differences were seen between IA patient populations. However, IA tissues contained higher bacterial load, species number, and Bifidobacterium adolescentis and Desulovibrio count when compared to controls. In addition, a number of opportunistic pathogens were also found in IA tissues. Based on our findings it is unclear whether microorganisms pay a role in IA progression, but they may suggest a possible microbial influence in aneurysmal disease as a whole.

abstract: M.Sc.


title: Christian Manhood on Crusade: A Gender Analysis of Clerical Discourses on Latin Masculinities, 1095-1120

contributor:
Husain, Adnan
History

subject: Gender Sexuality Medieval France Masculinity Manhood Crusades

abstract: The birth of crusading and the religious reform movements of the late eleventh century left deep impressions on how some clerical and lay authors thought about, described, and discursively represented the masculine ideals of laymen in Christian terms. These complex social and religious campaigns created a climate of penitentialism and lived religiosity that reshaped how clerics and laymen conceptualized performative aspects of masculinity and manhood. In texts written or mediated by clergy, laymen expressed sincere anxieties about gendered behaviour such as military violence and sexual intimacy, and critically examined their involvement in morally complex activities in charters, wills, chronicles, poetry and other surviving texts. This thesis investigates how laymen navigated and responded to these popular religious movements in documentary sources produced by clergy, and also by laymen themselves. It considers how lay conceptions of masculinity and manhood developed into the first decades of the twelfth century and were informed by these ideological currents.

abstract: PhD


title: Neural Correlates of Saccade Target Selection and Programming in Superior Colliculus

contributor:
Pare, Martin
Neuroscience Studies

subject:
Decision Making
Superior Colliculus
Noise Correlations
Threshold Mechanism
Decoding

abstract: Decision-making process involves sequential stages of sensory processing, perceptual selection of a target for the behavior, preparation of an action, and execution of that action. Superior colliculus is at the center of a network which integrates the sensory information into evidence towards decisions about whether, to where and when a saccade should be made, and is therefore a suitable model to explore different aspects of these stages. This work explores the dynamics of interactions of SC populations during a decision that involves selection of a particular stimulus among the alternative options as the target for a future saccade. I show that these interactions evolve in time along with the requirements of the task, and the patterns of this evolution are different among neurons from the same or different SC populations. I further explore the impact of correlations within the activity rates of these neurons on the efficiency of coding this decision variable. I show that while the variability in pairs of neurons seems to increase the available information about the encoded target for the saccade, they decrease the performance of two biologically plausible decoders over simulated large populations. Finally, I explore the role of neuros in intermediate layers of SC in saccade production in a task where the subjects anticipate the possibility of withholding a programmed saccade. I show that while an accumulation of evidence towards a decision to execute a saccade appears to happen in SC, this activity pattern cannot fully account for the behavior of the subject. SC should be mainly considered as the threshold unit that transfers this decision variable from an accumulation unit elsewhere in the brain, such as the frontal eye fields, to the execution unit in the brainstem. This work confirms previous findings on the role of SC in two perceptual and executive stages of a decision process and provides additional insights on the details of how these roles are implemented.

abstract: PhD


title: The Inhomogeneous Microstructure and Deformation of Similar and Dissimilar Al-Zn Containing Mg Friction Stir Welds

contributor:
Daymond, Mark
Mechanical and Materials Engineering

subject:
Friction Stir Welding
AZ80
AZ31
AZ61
Residual Stress
Residual Strain
Texture
Synchrotron
Strain Mapping
Periodicity
Onion Ring
Digital Image Correlation
Wormhole
Interface
Magnesium
Dissimilar

abstract:
The magnesium-based aluminum-zinc alloys have excellent stiffness to weight ratios, and may be combined by friction stir welding to expand the possible applications.  The high aluminum alloy AZ80 in particular has the advantage of being relatively stiff but still extrudable.  However limited friction stir welding research is available for this alloy and extrapolation from the extensive work in aluminum alloys is impractical due differences in precipitation behaviour, and magnesium's high plastic anisotropy and tendency to form strong textures during friction stir welding.

This work investigates the correlations between local friction stir welded microstructures, textures, residual strains, and the local deformation behaviour based on strain mapping during tensile tests. Covering bead-on-plate and butt configurations, joining of similar and dissimilar materials, and a range of processing conditions, many findings of interest for deformation modelling and industrial applications are presented.

Synchrotron x-ray diffraction study of an entire friction stir weld was used to determine texture, residual strain and dislocation density data from a single experiment.  A number of unique findings were made, mainly related to the asymmetric distribution of properties both between sides of the weld and through the depth.  Particularly in the case of strain measurements, features not detectable at coarser measurement spacing or by line scan are presented and compared for multiple processing conditions.

Investigation of the longitudinal material flow during welding showed that even when periodicity in grain size, precipitate distribution, or texture was not observed, periodic changes in texture intensity resulting from compaction of material behind the tool were present, providing evidence that movement of nugget material remained periodic.

Strain localisation and fracture behaviour were found to be completely different between good quality similar and dissimilar friction stir welds. For similar magnesium friction stir welds, higher heat input was shown to improve mechanical performance by reducing the residual strain, while for dissimilar friction stir welds, deformation behaviour was found to be more sensitive to the final material distribution in the friction stir weld nugget.  For dissimilar welds, even minor changes to the material flow were shown to have a major impact on the tensile performance.

abstract: PhD


title: CO2-Responsive Surfaces

contributor:
Jessop, Phillip
Cunningham, Michael
Chemistry

subject:
CO2
Carbon Dioxide
Switchable
Surfaces
stimuli-responsive
ATRP
AGET-ATRP
ARGET-ATRP
Polymer
Polymer-Grafted
Smart Surfaces

abstract: Designing smart materials with green chemistry in mind is a common theme throughout this thesis.  Smart surfaces, i.e. a surface that can perform multiple tasks as a function of an external stimulus, have the potential to reduce waste by simplifying processes, reducing solvent use, and extending the lifetime of materials through simple regenerative procedures.  The work presented in this thesis focuses on the development of CO2-responsive smart surfaces for green applications.  CO2-responsive smart surfaces have been used as desiccants for the removal of water from organic solvents.  For the first time, CO2-responsive smart desiccants were able to remove more water and were regenerated at a lower energy cost than traditional recyclable desiccants such as molecular sieves.  Additionally, CO2-responsive smart surfaces were demonstrated to be smart supports for heterogeneous catalysis with ruthenium nanoparticles by allowing reversible changes in catalyst selectivity for the hydrogenation of furfural.  In both applications, the CO2-responsive smart materials were recycled multiple times with little to no loss in performance.  CO2-responsive smart materials were demonstrated to selectively capture and release hydrophobic liquids and dyes without loss of performance over time.  A variety of substrates were evaluated as CO2-switchable surfaces using both single-unit and polymeric modifiers.  A robust and user-friendly method for “surface-initiated activators generated by electron transfer atom transfer radical polymerization” (SI-AGET-ATRP) is described.  The SI-AGET-ATRP technique is compatible with various CO2-responsive polymers and will allow future work to study topics of interest such as the relationships between grafting density, molecular weight, and material performance.

abstract: PhD


title: Identification of Novel Proteins Interacting with LATS1/2 During Tumorigenesis and Anti-Tubulin Drug Response

contributor:
Yang, Xiaolong
Pathology and Molecular Medicine

subject:
Hippo Pathway
LATS1/2
WWP1
Pin1
Cancer
Drug Resistance
Functional Genomics Screening
Breast
Lung

abstract:
The Hippo pathway is a signaling cascade that plays essential roles in organisms such as development, organ size control, stem cell differentiation and renewal, as well as important processes necessary for cancer development and progression. Within the core cassette of the pathway are LATS1 and LATS2, serine/threonine kinases with a continually expanding repertoire of functions and effectors that relay upstream tumor suppressive signals. Despite the plethora of studies investigating Hippo pathway signaling, few LATS1/2 interacting proteins have been identified.
In this thesis, the regulatory networks surrounding LATS1/2 are explored. By screening the Nedd4-like family E3 ubiquitin ligases, WWP1 was identified as a novel negative regulator of LATS1 by ubiquitinating and promoting its degradation by the 26S proteasome pathway. Importantly, loss of LATS1 stability was shown to be critical for WWP1-induced increases in cell proliferation and anchorage-independent growth of breast cancer cells. Furthermore, a novel signaling axis involving Cdk1, LATS2 and Pin1 was identified. After anti-tubulin drug treatment, activated Cdk1 kinase can directly phosphorylate LATS2 at five sites which subsequently binds Pin1 and inactivates its anti-apoptotic function. Lastly using CRISPR/Cas9 functional genomics screening, novel genes that promoted LATS2-induced S-phase cell cycle accumulation in lung cancer cells were identified and validated.
Collectively these findings uncover novel upstream regulators and downstream mediators of LATS1/2 in functions related to tumorigenesis and drug response. The novel interacting proteins identified in this work may serve as potential new biomarkers for breast and lung cancer progression as well as anti-tubulin drug sensitivity. Thus mapping the molecular network of the Hippo pathway, with emphasis on the bona fide tumor suppressors LATS1/2, may have significant implications for the prognosis and treatment of breast and lung cancers.

abstract: PhD


title: Metal-Ion Catalyzed Alcoholysis Based Disclosure Solution for the Detection of CW Nerve Agents on Sensitive Materials for Spray and Wipe-Based Applications

contributor:
Brown, Robert Stanley
Chemistry

subject:
chemical warfare agents
phosphonate
CBRN
sarin
sensitive equipment
disclosure solution
VX
chromogenic sensor
force protection
chemical detection
metal ion catalyzed alcoholysis
Sarin

abstract: Chemical warfare agents (CWA) are defined by the Chemical Weapons Convention as "any chemical which, through its chemical effect on living processes, may cause death, temporary loss of performance, or permanent injury to people and animals." Chemical warfare agents, such as the nerve agents and vesicants still pose a threat to global security and western interests. State and non-state actors continue to develop, stockpile, and weaponize these agents due to their mass effect on life, their ability to deny territory, and the ability to cause social and psychological distress. Since World War 1, CWA detection methodologies have been researched and implemented. They permit security forces and first responders to obtain early warning and adopt force protective measures. Briefly summarized is the chemistry of past and in-service chromogenic CWA detection systems, followed by a literature review of chromogenic and fluorogenic chemical-based detection methodologies currently being researched for nerve agents and vesicants. It is concluded that presently there is no suitable universal disclosure system or approach which can undergo an immediate, sensitive, and practical chromogenic response in the presence of CW nerve agents; phosphonofluoridates, phosphonocyanidates, and phosphonothioates. As a result, a novel and practical strategy is proposed and developed which combine La(III) metal-ion catalyzed alcoholysis (MICA) and chromogenic sensors. Since the strategy utilizes alcohol at neutral conditions, it can be employed to disclose CWA on sensitive materials. Three novel strategies are investigated for the detection of the phosphonofluoridates, two of which detect for F- produced via MICA. First, the cleavage of silylated ethers with a chromophoric core, and second, a displacement mechanism where F- interacts with La(III) resulting in the displacement of a metal-associated chromophoric sensor into solution. The third strategy focuses on the production and detection of H+, another product of MICA. The detection of phosphonocyanidates is adapted to this H+ strategy by the addition of a borderline M(II) that associates with the –CN product. Furthermore, a compatible sensor, 83, based on thiol-disulfide interchange, is developed and investigated for the detection of phosphonothioates. Finally, the sensors and methodologies are integrated into a stable universal solution, and its effectiveness demonstrated.

abstract: M.Sc.


title: As Above so Below? - Impacts of Water Limitation on Growth and Nutrient Accumulation of a Crop Plant and its Soil Microbes Across a Fertility Gradient

contributor:
Grogan, Paul
Biology

subject:
Leaf Sap
Metabolic
Soil
Microbial Biomass
Nitrogen
Potassium
Water Limitation
Crop
Agriculture
Fertilizer Gradient
Plant
Collard Greens
Brassica oleracea var. acephala

abstract: Strategies to increase crop yields and drought stress tolerance are urgently needed to meet future global food demands in a changing climate. Although the effects of fertilizer application and drought stress in agriculture have each been researched extensively, the combined impacts of these two factors on crop yield, soil microbes, and nutrient availability are not well understood. High soil nitrogen availability promotes rapid plant growth, and increases leaf sap nitrate concentrations, but reduces carbon-based solute concentrations. By contrast, plants accumulate carbon-based solutes in response to drought. This project evaluates changes in leaf sap composition in response to fertilizer and water availability, to determine whether a trade-off exists between reduced leaf sap carbon concentrations associated with rapid plant growth, and subsequent tolerance to water-limitation. My thesis research centred on a greenhouse experiment to investigate the effects of nitrogen and potassium fertilizer (NK) additions at three levels on soil microbes, shoot growth, and leaf sap composition of replicate (n=9) Collard greens (Brassica oleracea) before and after a moderate water-limitation treatment. Increasing levels of NK addition progressively enhanced shoot biomass, and the medium and high levels doubled leaf sap total nitrogen and halved leaf sap carbon concentrations after 63 days of growth (i.e. at the end of the ‘normal’ trial). However, after three-weeks of subsequent water-stressed conditions (i.e. at the end of the normal plus water-limitation phases – the ‘water limitation’ trial), shoot biomass increases maintained a similar growth pattern to the normal trial, indicating that low leaf sap carbon concentrations did not reduce the subsequent shoot growth rate under water-limited conditions. Soil microbial N accumulation was equivalent across all fertilizer addition levels at the end of the normal trial, but increased progressively with NK addition after the water-limitation trial. Finally, leaf sap nitrate correlated closely with soluble soil nitrate, indicating that the former may provide an effective low-cost in-field test to determine the status of soluble nitrogen in agricultural soils. Overall, I found new and important relationships among leaf sap, soil microbial biomass, and bulk soil nutrient pools that will contribute to the improvement of soil management practices to meet the agricultural challenges of the future.

abstract: M.Sc.


title: Improving Communication Performance in GPU-Accelerated HPC Clusters

contributor:
Afsahi, Ahmad
Electrical and Computer Engineering

subject:
HPC
GPU
Communication performance
MPI

abstract:
In recent years, GPUs have been adopted in many High-Performance Computing (HPC) clusters due to their massive computational power and energy efficiency. The Message Passing Interface (MPI) is the de-facto standard for parallel programming. Many HPC applications, written in MPI, use parallel processes and multiple GPUs to achieve higher performance and GPU memory capacity. In such applications, efficiently performing GPU inter-process communication is the key in the application performance.

In this dissertation, we present proposals to improve the GPU inter-process communication in HPC clusters using novel GPU-aware designs, efficient and scalable algorithms, topology-aware designs, and hardware features. Specifically, we propose various approaches to improve the efficiency of MPI communication routines in GPU clusters. We also propose designs that evaluate the total application inter-process communication and provide solutions to improve its efficiency.

First, we propose efficient GPU-aware algorithms to improve MPI collective performance. We show the importance of minimizing CPU intervention on GPU collective performance. We also utilize GPU features to enhance both collective communication and computation. As inter-process communications scale to across multi-GPU nodes and clusters, efficient inter-process communication routines must consider the physical structure of the underlying system. Given the hierarchical nature of the GPU clusters with multi-GPU nodes, we propose hierarchy-aware designs for GPU collectives and show that different algorithms are favored at different hierarchy levels.

With the presence of multiple data copy mechanisms in modern GPU clusters, it is crucial to make an informed decision on how to use them for efficient inter-process communications. In this regard, we propose designs that intelligently decide which data copy mechanisms to use in GPU collectives. Using these designs, we reveal the importance of using multiple data copy mechanisms in performing multiple inter-process communications.

Finally, we provide topology-aware solutions to improve the application inter-process communication efficiency, both within multi-GPU nodes and across GPU clusters. First, we study the performance of different communication channels used for GPU inter-process communications. Next, we propose topology-aware designs that consider both the system physical topology and application communication pattern. These designs improve the communication performance by performing more intensive inter-process communication on stronger communication channels.

abstract: PhD


title: Far-Field Stress Determination Using Seismic Stress Inversion

contributor:
McKinnon, Stephen D.
Mining Engineering

subject:
Geomechanics
Seismic Stress Inversion
Far-field Stress Determination
Mining Seismicity

abstract:
The objective of this research is to develop tools and methodologies to achieve more reliable information about the stress field in deep mines, especially around mining excavations by using the method of seismic stress inversion.
After investigating several stress inversion algorithms, one method, MOTSI, has been applied to the seismic data collected from Nickel Rim South Mine (NRS) located in Sudbury, Canada. Although NRS hosts relatively massive rock mass with high strength, it is structurally complicated. There are many faults located in the mine, which can both influence the stress field and be the source of seismic events. The seismic array has good coverage over the active volume of the mine and consists of a number of sensors with different types (uniaxial and triaxial geophones and accelerometers). This combination of sensors covers the seismic events with a range of moment magnitudes between -3 and 3. Extensive filtering has been applied to the seismic data and finally, for mapping the stress field, more than 1000 seismic events were manually processed and after removing noise and applying different filters, it was possible to determine the orientation of the principal stresses through seismic stress inversion from the middle level of the mine. The aggregate of the inversions inferred a north–south, northeast/southwest orientation of the maximum principal stress and near vertical minimum principal stress.  In each inversion processed, several events were tagged as outliers according to the MOTSI software criteria. Several statistical analyses including mean, standard deviation, variance, t-test, box plot, Kruskal–Wallis test, and principal component analysis (PCA) were conducted over 10 seismic source parameters (i.e. source radius, seismic moment, etc.) to determine the relation between outliers and used data. Finally, a relation between principal stresses and relative stress ratio has been described and the application of this relation and the overcoring stress measurements for determining the far-field stresses are explained.
Based on the results of this research, guidelines are prepared outlining how the stress inversion technique can be applied to mining seismicity to extract information about the stress field.

abstract: PhD


title: Nationalism and Pre-Raphaelite Art

contributor:
Helland, Janice
Art History

subject:
Pre-Raphaelite
Nationalism
Rossetti
Millais
Hunt
Victorian
National Identity
Victorian Religion
Evangelicalism
Art Market
Crimean War
Irish Potato Famine

abstract: Recent scholars of Pre-Raphaelite art have focused on the history of women, material culture, and social context. An area that has received little attention is the concept of nationalism and national identity. This thesis closely examines the influence of such ideas through paintings created by Dante Gabriel Rossetti, John Everett Millais, and William Holman Hunt, between 1848 and 1865. To outline these directions, artist biography, correspondence, and the nineteenth-century British press were considered critically. What this study reveals is that Pre-Raphaelite art was heavily influenced by socio-political, national and international events. Previously, Rossetti, Millais, and Hunt were understood to be rebellious, anti-establishment artists; this study shows that these artists were aware of their shifting political and cultural atmosphere, and consciously catered to national sentiment in order to gain financial success. Early paintings of Rossetti, Millais, and Hunt coincide with the religious, evangelical fervour of the mid-nineteenth century. I argue that Rossetti continued to appeal to religious buyers through a Cycle of Mary images in the 1850s and was influenced by the Morant Bay Rebellion (1865) in his creation of The Beloved (1865, Tate). In the early 1850s, Millais appealed to popular opinion in his works through commentary on the Protestant-Catholic debates, and the Crimean War (1853-56). Through their correspondence, we now know that Millais and Rossetti did not share the views represented in their art, which further highlights the financial motivations behind the paintings. Furthermore, I argue that the early reviews of Pre-Raphaelite paintings were affected by the national religious mood, and coincidentally by the Irish Potato Famine (1845-52). A study of the press reveals stark similarities in language between these reviews and the debates on national and international events. Unlike Rossetti and Millais, Hunt relied on his personal beliefs to create his early religious paintings. However, I argue that to attract specific buyers such as Thomas Combe and Ernest Gambart, Hunt modelled his paintings after popular evangelical sermons. Through the lens of nationalism, this study offers a new perspective which can help unify the often-fragmented study of Pre-Raphaelite art, and make it relevant across multiple disciplines.

abstract: PhD


title: Examining Sex Differences in Hippocampal Theta Activity in Relation to Anxiety-Like Behaviours in Rats

contributor:
Dringenberg, Hans
Neuroscience Studies

subject: Sex Difference in Hippocampal Theta Activity

subject: Hippocampal Theta

subject: Theta Suppression Model

subject: Theta Activity Anxiety

subject: Sex Difference in Anxiety

abstract:
Hippocampal theta activity is an oscillatory, highly rhythmic (4-14 Hz) activity pattern generated by the hippocampal formation of mammals. Theta activity has been linked to anxiety states in rodent, based on a number of studies showing that anxiety-reducing pharmacological agents (anxiolytics) consistently decrease the frequency of theta activity in rats, leading to the influential “theta suppression model of anxiolysis.” To this date, very few studies have systemically compared anxiety-related defensive behaviour and hippocampal theta activity in males and females. The primary objectives of this thesis were to examine a possible association of theta frequency and behavioural levels of “anxiety” in individual rats, and to examine
potential sex differences in anxiety, theta activity, and the anxiety-theta association. Female and male rats were tested on the elevated plus maze (EPM), a common paradigm to assess anxiety in rodents. Interestingly, the findings reveal that females exhibited higher amounts of open arm activity (number of open arm entries and open arm time) compared to males, indicative of reduced “anxiety” in females. Following the behavioral assessment, the same rats were anesthetized using urethane and underwent electrophysiological procedures to characterize hippocampal theta frequencies activity. Theta activity was recorded in the CA1 field of the hippocampus and was elicited by electrical stimulation of the brainstem reticular formation (consisting of 5-s trains of 0.1 ms duration pulses delivered at 100 Hz). Systemic administration of the clinically used anxiolytic drug buspirone, which acts as a partial agonist at 5-HT1A receptors, was shown to decrease the frequency of theta activity, a finding that is in agreement with prior work. These experiments showed that there was no sex difference in theta frequency, and that theta frequency in individual rats did not correlate with behavioral measures of anxiety in the EPM. Together, the results of this work show that theta frequency does not predict levels of anxiety-like behavior in the EPM and challenge the predictive validity of hippocampal theta frequency as an index of anxiety levels.

abstract: M.Sc.


title: Authority, Communication and Discrimination in Agency Models

contributor:
Zabojnik, Jan
Viero, Marie-Louise
Cotton, Christopher
Economics

subject: Authority Communication Discrimination Organization

abstract:
This thesis develops three theoretical frameworks to investigate questions relating to authority within both firms and governments as well as discrimination in the labor market. The first chapter develops a theoretical framework that incorporates the deleterious effects of tournaments on cooperation in order to generate a more complete theory of the optimal organizational structure. I study how well information will be generated by the agents and utilized by the decision maker(s) in either a centralized or a decentralized setting. I show that tournaments can achieve what I refer to as the Constrained First Best outcome and will negatively impact cooperation only in a decentralized setting. This chapter also suggests that a limited liability constraint will increase the complementarity between decentralization  and the agents' productivity. Furthermore, I argue that periods of economic contraction will favor a centralized setting and I uncover a trade-off between communication noise, which depresses centralized profits, and production noise, which depresses decentralized profits.

	Using a model with an overall population consisting of two different groups, the second chapter shows that imposing optimal constraints on the set of implementable policies based on demographics and misalignment of preferences increases social welfare. I also argue that the more misaligned the preferences of two groups are, the more restrictive these optimal constraints should be. When using these optimal constraints or no constraints at all, allocating power based on the plurality rule is optimal. However, if restrictive suboptimal constraints are utilized, then allocating power to a minority group becomes potentially optimal. Finally, I show that while overly-lax suboptimal constraints still increase welfare, overly-burdensome suboptimal constraints do so if the two groups' preferences are sufficiently misaligned.

	The third chapter provides a theoretical framework to compare two different hiring practices: an unpaid competitive internship which is followed by a potential job offer versus a standard series of interviews. After fully characterizing the optimal hiring process, I show that labor regulations that ban the use of unpaid internships or that prevent employers from giving truthful references can exacerbate the obstacles to employment of a community traditionally facing discrimination.

abstract: PhD


title: Characterization of the Human Atypical Kinase, aarf Domain-Containing Kinase 3, and its Substrates Required for Coenzyme Q biosynthesis

contributor:
Jia, Zongchao
Biomedical and Molecular Sciences

subject:
ADCK3
Coq8
Protein Expression
Protein Purification
X-Ray Crystallography
Coenzyme Q
Coq5
Coq7
Methyltransferase
ATPase Activity Assay
Kinase Activity Assay
Protein Kinase
Atypical Kinase
Co-Immunoprecipitation

abstract:
Aarf domain-containing kinase 3, ADCK3, is a human atypical protein kinase located in the inner membrane of the mitochondria that is required for the biosynthesis of coenzyme Q (CoQ). Stable supply of CoQ is essential to human health as it plays a critical role as an electron transporter in the electron transport chain which is required for proper ATP production. Although the exact role of ADCK3 is unknown, patients possessing mutations within this gene are often diagnosed with autosomal recessive cerebellar ataxia type 2, which results from CoQ deficiency. To better understand the involvement of ADCK3 and other proteins in CoQ biosynthesis, their structure, function, and their interactions with each other were investigated. ADCK3 is hypothesized to regulate the CoQ biosynthesis using its kinase activity to activate several proteins found in the CoQ biosynthetic complex; however, previous work has failed to show direct evidence of its kinase activity and its functional interaction with the other Coq proteins.
In this work, using a soluble construct of ADCK3, we solved its structure by X-ray crystallography. Various constructs of ADCK3 were transfected into Human Embryonic Kidney cells in an attempt to extract and identify its substrates. Further, the genes of the potential substrates, Coq3, Coq5, and Coq7 were cloned into various expression vectors and transformed into Escherichia coli expression cell lines. After the extensive expression trials, the combination of N-terminal fusions with maltose-binding proteins and the RIPL E. coli cell expression line was found to facilitate the expression of Coq5 and Coq7. However, using radiometric kinase assays, we show that ADCK3 exhibited no kinase activity towards Coq5 and Coq7. Finally, this work also shows the methyltransferase activity of Coq5 using its substrate analog. It is anticipated that our results will serve as a foundation for further characterization of the proteins involved in the human CoQ10 biosynthesis.

abstract: M.Sc.


title: Richardson Among the Philosophers: Interiority, Perspective, and Formal Irony In the Fiction of Samuel Richardson

contributor:
Fanning, Christopher
English Language and Literature

subject:
Richardson, Samuel
Interiority
Perspective
Philosophy
Irony
Hume, David
Smith, Adam

abstract:
Samuel Richardson developed a narrative technique that recreates the epistemological and ontological conditions of selfhood theorized by empiricist philosophy; these conditions are the complex interplay between interior and exterior states that creates interiority and the dynamics of limited perspective. This technique I call formal irony. Locke, Hume, and Smith all theorize selves that exist as ontologically separate minds with epistemologically limited perceptions; by developing a narrative technique that recreates these conditions, Richardson represents characters as separated from others (what I call social irony) and separated from their own hearts (internal irony). Richardson considered these conditions problems, however, and each of his novels is an attempt to solve them, though these solutions are often made provisional by the very conditions they attempt to escape.
	In chapter 1, I theorize my major terms and begin my investigation of interiority and perspective by examining Locke’s theory of language in An Essay Concerning Human Understanding. In chapter 2 I read Pamela alongside Hume’s A Treatise of Human Nature and examine the way Richardson represents character as a function of limited perspective, the way he uses disclosure to solve the separations created by interiority, but also the way disclosure is a naïve solution, one that does not fully account for the distortions of self. In chapter 3 I read Clarissa and examine the way Richardson, now more aware of the complications of interiority and perspective, further explores separation by including multiple narrators who use competing hermeneutics. Richardson uses typology as a solution to these problems; his typological solution, however, though it appears to resolve the separation of self and heart, fails to resolve the separation of self and other. In chapter 4 I read Grandison alongside Smith’s A Theory of Moral Sentiment and examine the way Richardson uses deliberate acts of imaginative transposition to transcend the limitations of self and solve the separation of self and other; this solution is only possible, however, because Richardson re-fashions the self to be less of an individual. Richardson, I argue throughout, is an innovator, someone constantly re-examining the problems of the self and constantly proposing new solutions.

abstract: PhD


title: Laboratory Ultrasonic Pulse Velocity Logging for Determination of Elastic Properties from Rock Core

contributor: Geological Sciences and Geological Engineering

subject:
Laboratory Ultrasonic Testing
Elastic Modulus
Rockburst Hazard
Drill Core Assessment

abstract: During the development of deep underground excavations spalling and rockbursting have been recognized as significant mechanisms of violent brittle failure. In order to predict whether violent brittle failure will occur, it is important to identify the location of stiffness transitions that are associated with geologic structure. One approach to identify the effect of geologic structures is to apply borehole geophysical tools ahead of the tunnel advance. Stiffness transitions can be identified using mechanical property analysis surveys that combine acoustic velocity and density data to calculate acoustic estimates of elastic moduli. However, logistical concerns arise since the approach must be conducted at the advancing tunnel face. As a result, borehole mechanical property analyses are rarely used. Within this context, laboratory ultrasonic pulse velocity testing has been proposed as a potential alternative to borehole mechanical property analysis since moving the analysis to the laboratory would remove logistical constraints and improve safety for the evaluators. In addition to the traditional method of conducting velocity testing along the core axis, two new methodologies for point-focused testing were developed across the core diameter, and indirectly along intact lengths of drill core. The indirect test procedure was implemented in a continuous ultrasonic velocity test program along 573m of drill core to identify key geologic structures that generated transitions in ultrasonic elastic moduli. The test program was successful at identifying the location of geologic contacts, igneous intrusions, faults and shear structures. Ultrasonic values of Young’s modulus and bulk modulus were determined at locations of significant velocity transitions to examine the potential for energy storage and energy release. Comparison of results from different ultrasonic velocity test configurations determined that the indirect test configuration provided underestimates for values of Young’s modulus. This indicated that the test procedure will require modifications to improve coupling of the transducers to the core surface. In order to assess whether laboratory testing can be an alternative to borehole surveys, laboratory velocity testing must be directly assessed with results from acoustic borehole logging. There is also potential for the laboratory velocity program to be used to assess small scale stiffness changes, differences in mineral composition and the degree of fracturing of drill core.

abstract: M.A.Sc.


title: Navigating Canadian Drone Space: A Sociological Analysis of the Stakeholders, Narratives, and Policy Shaping Canadian Unmanned Systems

contributor:
Lyon, David
Sociology

subject:
Canada
Drones
Stakeholders
Policy
Contemporary sociological theory

abstract:
In this dissertation, I undertake an in-depth examination of the stakeholder networks and narratives that are driving and shaping drone technologies and corresponding policy within Canada. It examines how and why some stakeholder groups have been excluded from various regulatory processes for drones, and how the inclusion and exclusion of certain groups in regulatory processes impacts the deployment of these technologies, and thus impacts on privacy and civil liberties. The adoption and use of drone technologies represents and perpetuates a politics of verticality that allows particular stakeholder groups to control Canada’s sociotechnical space through policy, and this contributes to a privileged vertical gaze where only particular groups and technologies can operate drones. This dissertation theorizes Canadian drone space as being shaped by the logics of dominant stakeholder groups, and addresses the ways in which civil liberties and privacy implications as well as surveillance-sensitive aspects of drones are not adequately addressed because of who is excluded from these spaces.

This dissertation argues how the seemingly benign relationships between particular stakeholder groups in Canadian drone space are the product of a ‘revolving door’ in the surveillance-industrial complex. The relationships that have developed around drones between certain stakeholder groups (primarily government, industry, and military) show how other stakeholder groups (such as civil liberties advocates, lawyers, and privacy experts) have long been excluded from the development of drone regulation processes in Canada. I put these politics of exclusion into dialogue with Andrew Barry’s theory of technological zones and Pierre Bourdieu’s field theory. These theories help to explain how the field of power within which stakeholders operate contributes to them a) only associating with specific stakeholder groups, b) upholding particular logics and predispositions about drone technologies, and c) perpetuating discourses and narratives about the technological zone of drones that impacts the technologies themselves, the regulation of drones, and Canada’s sociotechnical space more broadly. Drawing on semi-structured interviews with stakeholders as well as extensive analyses of primary documents obtained through Access to Information and Privacy requests, these data are parsed through thematically to demonstrate the contrasting positions of stakeholder groups in the regulatory process, in assessing risk and the market, and in media portrayals of drone technologies.

abstract: PhD


title: Free Radical-Mediated Reactive Extrusion of Commodity Polymers

contributor:
Kontopoulou, Marianna
Chemical Engineering

subject:
Polymers
Reactive extrusion
poly(lactic) acid
Poly (propylene)
Co-agent modification
Free-radical mediated
Foaming
Foams
Branching
Nucleation
Mechanical Properties
Degradation

abstract:
The objective of this thesis is to improve the melt and solid-state properties of poly (propylene) (PP) and poly(lactide) (PLA) by reactive extrusion. Peroxide-mediated melt-state reactive extrusion in the presence of mesate and acrylate-based coagents was implemented to introduce branching and enhance the strain hardening, crystallization kinetics and solid state properties of these commodity polymers, to make them conducive to more high-value applications. The coagent modified PP possessed bimodal molecular weight and branching distributions, whose population varied with coagent structure. Besides changing polymer chain architecture, chemical modification generated a small amount of well-dispersed, coagent-derived nanoparticles. When compared with the parent material and PP samples treated with peroxide alone, coagent-modified materials demonstrated significantly higher crystallization temperatures and crystallization rates, as well as a finer spherulitic structure. Crystallization studies showed that whereas branching had a moderate effect on crystallization kinetics, heterogeneous nucleation effects dominated the crystallization of coagent-modified PP materials. Coagent modified PP specimens prepared by injection molding retained the modulus and tensile strength of the parent PP, in spite of their lower molar mass and viscosities, whereas their elongation at break and the impact strength were improved. This was attributed to the finer spherulitic structure of these materials, and to the disappearance of the skin-core layer that typically forms during the injection molding process.
In the second part of this thesis, structure-property relations of PLA, branched by peroxide-mediated reactive extrusion in the presence various coagents was carried out.  The coagent modified PLA, consisted of mixtures of linear, and long chain branched (LCB) PLA chains. A trifunctional coagent (triallyl trimesate, TAM) was extremely effective in producing LCB structures, which promoted substantial increases in viscosity, elasticity, as well as strain hardening characteristics. The reactively-modified injection molded branched PLA formulations had improved Izod impact strength, while maintaining their capacity to degrade hydrolytically were maintained. Furthermore, these materials developed high amounts of crystallinity, when cooled under controlled conditions, revealing a nucleating effect. The improvements in strain hardening resulted in microcellular foams with very high cell densities and sub-micron sized cell size, when these formulations were foamed at temperatures close to the crystallization temperature of the polymer.

abstract: PhD


title: An Investigation of the Effects of Wavelength Shifter Thickness on Backgrounds for the DEAP-3600 Dark Matter Direct Detection Experiment

contributor: Physics, Engineering Physics and Astronomy

subject:
Dark Matter
DEAP-3600
Backgrounds
Tetraphenyl Butadiene
TPB
Argon

abstract:
Several lines of astronomical evidence indicate that most of the matter in our universe is made of non-luminous material known as dark matter, the nature of which remains a mystery. DEAP-3600 is a liquid-argon-based scintillation detector located 2 km underground outside Sudbury, Ontario, Canada, purposed towards directly detecting dark matter particles as they pass through the target material. Since the acrylic vessel containing the 3600-kg liquid argon target is not transparent to the 128-nm scintillation light produced during these interactions, a thin layer of 1,1,4,4-tetraphenyl-1,3-butadiene (TPB) was deposited onto the inner surface of the acrylic vessel to shift the wavelength of the scintillation light to the visible range, where is can pass through the transparent acrylic vessel and is more easily detected by the surrounding array of photomultiplier tubes.
The dark matter signal in DEAP-3600 is accompanied by a host of other background signals, which must either be suppressed, or identified as background signals and subsequently cut from the analysis. A major anticipated source of background events is alpha decays of radioactive isotopes on the inner surface of the acrylic vessel, near the TPB layer. The potential for these events to generate a background signal depends sensitively on the choice of thickness of the TPB layer. A study of the effects of TPB layer thickness on the background rate of these surface alpha events is presented, and a model for the dominant contributor to these background events is developed to generate estimates of the probability that an event of this type would mimic a dark matter signal. Other effects considered in the choice of TPB layer thickness are presented, and the final decision of a 2.99 +- 0.02 micron TPB layer thickness, along with the TPB deposition campaign, is briefly described.

abstract: M.Sc.


title: In Praise of Rebellion: Constituent Power, Democracy, and the American Revolution

contributor:
Essert, Christopher
Santiago, Homero
Law

subject: Constituent Power. Democracy. American Revolution. Federalists. Pennsylvania.

abstract: There seems to be a consensus today that representative democracy is facing a period of severe crisis. Contemporary scholars and popular commentators from the most diverse backgrounds and political leanings seem to agree with this diagnosis. Voting, party membership, trust in politicians, and interest in mainstream politics, the most celebrated indicators of political scientists to measure representative democracy’s “health,” are all under great stress in several countries. However, a closer look at the history of what we today call “representative democracy” would reveal that the current crisis (although perhaps one of the most severe) is not really original. On the contrary, representative politics has been time and again plagued by the explosion of crisis. To address this vexing question, this dissertation adopts the following strategy. Initially, it situates its analysis within the context of the American Revolution. Since the American Revolution represents one of the most important events for the emergence of the project of “representative democracy,” the examination of aspects of this episode can provide insight for understanding the frequent crises of representative politics more generally. In addition, this dissertation examines the dispute over the concept of constituent power (and democracy) that erupted throughout the American Revolution between the Federalists and the dissident strands of the Revolution. The investigation of this dispute has two main goals. The first is to present an alternative path for the dominant view on constituent power (and democracy). The second is to provide insights for the reflections on the limits of representative democracy. On this latter point, I argue that the alternative perspective of constituent power can function as a potent tool to address the recurrent crisis of democracy.

abstract: PhD


title: The Viability of Lithogeochemistry and Surficial and Surficial Geochemistry in Detecting CU-AU Porphyry Mineralization Under Cover in the Lachland Fold Belt, Australia

subject:
Geochemistry
Mineral Exploration
Biogeochemistry
Lithogeochemistry
Pb Isotopes
Geology

abstract:
The Racecourse prospect is a possibly economic alkalic Cu-Au porphyry system, situated within the Macquarie Arc, NSW, Australia. Similar in age to both the Ordovician Cadia and Northparks districts of NSW, a volcano-sedimentary host sequence was intruded by two monzonitic porphyry complexes through fluid conduits created by the cross arc architecture of the Lachlan Transverse Zone. Prior industry workers have intersected two intrusive suites at Racecourse; the feldspar porphyry remains mineralized, fertile, and postulated to be the main mineralizing suite. Pearce Element Ratio diagrams for the three main lithologies intersected at Racecourse were created to perform a lithogeochemical prospectivity analysis. Two hundred eight whole rock samples representing the three lithologies were selected from data supplied by Anglo American Exploration Australia. There is a lack of hydrolytic alteration, and minimal alteration experienced by the system as a whole as illustrated by the PERs. Instead, the feldspar porphyry carries a relatively unaltered geochemical signature. Economic metals have no apparent relation to type of alteration. Mineralization is hosted by specific rock types, with Cu mineralization related to the feldspar porphyry, and Au occurring at low concentrations throughout all units.
Soils and Pinus radiata tree cores were collected above and distal to mineralization in order to outline the covered prospect’s signature. Soil samples were sieved with the <250 m size analyzed, and show distinct anomalous populations of Au, Cu, Mo, Pb, and Zn above prior drilling. Rings of Pinus radiata were counted, with the age interval of 2003 – 2008 chosen to sample. Samples show elevated Cu, Mo, and Zn above the previously drilled soil anomaly, whereas the southwest of the survey area reveals a Cu anomaly corresponding to localized faulting. 206Pb/204Pb values from the Pinus radiata identify distinct anomalous groups spatially associated with discrete metal anomalies. At the Racecourse target, anomalous Pinus radiata samples yield a similar isotopic signature to the faulted southwestern anomaly, potentially linking the source of these two metal anomalies as the feldspar porphyry. When integrated with subsurface geology and the current understanding of the mineralized body, geochemical media suggest that mineralization may continue down plunge at depth.

abstract: M.Sc.