VictorJuiz/thesis huggingface dataset:
Major and Trace Element Geochemistry of Ilmenite Suites from the Kimberley Diamond Mines, South Africa

A method was developed to distinguish between ilmenites from different mantle xenoliths found at Kimberley, South Africa: Granny Smith, dunites, orthopyroxenites, MARID and rutile-ilmenite intergrowths. The method employs a number of oxide screens based on MgO, TiO2 and Cr2O3 and systematically eliminating whole fields defined by mathematical equations. The classification scheme is useful to better understand the source of the ilmenite and has been applied to ilmenite xenocrysts from four diamond mines in the Kimberley area: Bultfontein, Kamfersdam, Otto's Kopje and Wesselton. A relationship between ilmenite chemistry and its paragenesis exists, but it is not as clear as in the Cr-poor megacrysts. A more complex process is responsible for the crystallization of ilmenite in the five different suites at Kimberley, and metasomatim by a Fe-Ti rich magma or melt, similar in composition to the parent magma of the South African megacrysts, plays an important role in ilmenite formation.

Advisor: Schulze, J. Daniel
The Classifying Work of Immigration Policies in Canada: A Critical Analysis of the Temporary Foreign Workers Program and Access to Settlement Services

In this thesis I analyse the Canadian Temporary Foreign Workers Program (TFWP) through the lens of Bowker and Star's classification theory. I connect the pervasive abuse and exploitation of temporary foreign workers in Canada to an immigration classification scheme that I argue favours particular economic interests of Canadian employers and workers over the interests of temporary foreign workers. To this end, I outline the nature of the TFWP discussing how employer-centric program intentions shape program structures. In turn, I argue that these structures shape the lives of migrants in Canada by restricting the rights, opportunities, and protections they have in Canada. To illustrate this, I discuss the use of immigration classifications to designate eligibility to receive settlement services in Canada.

Keywords: Bowker and Star
Canada
Classification
Immigration
Settlement services
Temporary Foreign Workers Program
Advisor: Shade, R Leslie
Prostate Cancer as a Metabolic Disease - Is Prostate Cancer Diagnosis Associated with Worse Cardiovascular Outcomes?

Metabolic syndrome (MetS) and prostate cancer (PC) share several risk factors. In addition to increased cardiovascular risk, there is evidence that men with MetS have an increased PC risk. Given that both diseases develop over decades, PC diagnosis may precede the onset of MetS, and may be an early indicator of cardiovascular risk. We sought to determine if PC diagnosis is associated with increased risk of subsequent cardiovascular event. In our population-based study using administrative databases, men with PC identified using the Ontario Cancer Registry were hard-matched and propensity score-matched to men without PC diagnosis identified using the Registered Persons Database. Competing risks analyses were performed to compare risk of cardiovascular events. Contrary to our hypothesis, men with PC were less likely to experience a cardiovascular event compared to men without PC (sub-distributional HR=0.92, 95%CI=0.88-0.96). The difference was not clinically significant. Selection bias and confounding may explain this unexpected result.

Keywords: Cardiovascular disease
Metabolic syndrome
Propensity score
Prostate cancer
Advisor: Alibhai, MH Shabbir
Chiral Guanidines as Chiral Shift Reagents for Imino Acids and as Catalysts for Transamination

This thesis explores the practical applications of DPEN (1,2-diphenylethylene diamine) guanidine as a chiral shift reagent for imino acids and as a catalyst for transamination. A fast and simple three-component protocol in determining the enantiopurity of amino acids by 1H NMR spectroscopy is described. Racemic amino acids are solubilized in CDCl3 with the chiral guanidine to form diastereomeric salts. The salts are reacted with 2-pyridinecarboxaldehyde to form the imino acid salts where the 1H NMR signals of the ortho-hydrogens on the pyridine group for the pairs of diastereomeric imino acid salts are well resolved for determining the enantiopurity of 8 amino acids.Pyridoxamine analog 2-(aminomethyl)-4,6-dichlorophenol was found to be 100 times more reactive than 2-(aminomethyl phenol). 2-(aminomethyl)-4,6-dichlorophenol transaminates acetophenone, 2-acetylpyridine, 4-nitroacetophenone and methyl pyruvate into their respective products. DPEN guanidine catalyzes the transamination reaction but the stereoselectivity is too low to be detected.

Advisor: Chin, Jik
Design and Implementation of a Feedback Control System for the Ex Vivo Expansion of Hematopoietic Stem Cells

Hematopoietic stem and progenitor cell (HSPC) transplantation provides a curative stem cell therapy for hematological pathologies. Umbilical cord blood (UCB) is an attractive source of these cells, and ex vivo expansion would make these cells available to more patients. This endeavor is challenged by the accumulation of endogenously produced signaling factors in vitro, limiting HSPC expansion. We hypothesized that regulating these factors in real time with a feedback control system would enhance expansion. We combined a novel protein quantification assay with a fed-batch bioreactor system to dilute soluble factors, reducing their impact and improving expansion. We developed a mathematical model to further investigate the impact of feedback control on HSPC culture, and used it to design a sophisticated control algorithm to maximize the volumetric efficiency of the fed-batch culture system. This use of feedback control for stem cell culture provides an important step towards a robust bioprocess for HSPC expansion.

Keywords: hematopoietic
stem cell
Advisor: Zandstra, W Peter
Cu@Cu2O@CuO Graded Nanowire Heterostructures for CO2 Reduction

Cu@Cu2O@CuO graded nanowire heterostructures were successfully synthesized from Cu nanowires (NWs) by thermal oxidation in air. The oxidation level and amount of Cu, Cu2O and CuO in this nanostructure could be controlled by applying different reaction temperatures and times. This heteronanostructure is shown to have a metal-core and an oxide-corona structure. Moreover it has excellent optical absorption in the visible region which is a valuable material characteristic for driving light assisted reactions for CO2 reduction. Coated with δ-FeOOH as co-catalyst, the Cu@Cu2O@CuO@δ-FeOOH NWs show CO2 catalytic activities with a maximum carbon monoxide (CO) production rate of 631.3 nmol g-1 hr-1 at 150°C reduced by H2 in the dark. In the presence of light, surprisingly the CO production rate goes down but the cause of this photo-deactivation phenomenon will draw interest for further study.

Keywords: CO2 reduction
fuel
nano materials
solar
Advisor: Perovic, D Doug
Art Around the Belly: Tracing the Cultural Significance and Artistic Value of Belt Hooks in Ancient China

The belt hook was used to fasten garments in ancient China long before the existence of belt buckles or plaques. Its use first appeared more than five thousand years ago and can be prevalently observed in paintings, on statuettes, and even on the famous Terracotta Army. Although it was such a common personal ornament, little has been written on this subject. My thesis will explore, through excavation data, coupled by my research on the extensive collection of belt hooks at the Royal Ontario Museum, how the examination of these ancient Chinese ornaments can not only reveal the status and wealth of its wearer, but also the cultural complexities and social advancements of that time.

Keywords: Artifact
Belly
Belt Hooks
China
ROM
Royal Ontario Museum
Advisor: Shen, Chen
Effects of Long Term Memory on Auditory Spatial Attention

We examined how associations between real world auditory scenes and the location of an embedded auditory target influence spatial attention after a delay period. Healthy young adults (N= 16) formed strong memories for spatial locations of targets within sound scenes, which biased attention one hour later. Participants showed gains in reaction time (100ms) and accuracy (12% increase) to locate targets proceeded by valid memory cues (scenes for which target-context associations were formed) compared to neutral cues. We also found a positive relationship (r =.55, p

Keywords: auditory
long term memory
magnetoencephalography
memory cue
spatial attention
Advisor: Alain, Claude
The Temporal Trends and Fish Consumption Advisories of Mercury and PCB Contaminants in Lake Trout and Walleye from Lake Ontario, Canada

The first part of our study evaluates the temporal and gender specific trends of the two contaminants in walleye

Keywords: Bayesian Inference
Dynamic Linear Modeling
Fish Consumption Advisories
Multilevel/Hierarchical Modeling
PCB and Mercury Contamination
Prey-Predator Interactions
Advisor: Arhonditsis, B George
Simulating Thermal Effects of MR-guided Focused Ultrasound (MRgFUS) in Cortical Bone and its Surrounding Tissue

High intensity focused ultrasound (HIFU) has been proposed as an alternative treatment for osteoid osteoma and bone metastases. To overcome current issues planning and monitoring HIFU procedures, this project proposes a simulator that predicts the temperature distribution during therapy. The bone is segmented from MR images using a semi-automatic algorithm, acoustic calculations are performed using the Rayleigh integral, and thermodynamic calculations using Pennes' Bioheat equation. The algorithm segmented with a sensitivity of 85 ± 4% and a mean volume error of 5 ± 11%. The simulation had a maximum temperature error of -2.4 ± 11.7°C, had a spatial error of 3.61 ± 1.61mm, and could be computed in less than 40s on over 10^8 points. Although these results were deemed insufficiently accurate for clinical software, the fast computation time and the modifiable framework have shown that this project was a first step in developing a clinically relevant simulation.

Keywords: Bone
HIFU
MRI
Therapeutic
Tumour
Ultrasound
Advisor: Drake, James
Nature of Production Blast Malfunctions: A Creighton Mine Case Study

The occurrence of blast malfunctions is investigated for deep underground production stopes at Vale's Creighton mine. Over the course of six years, multiple stope blasts were recorded throughout Creighton with triaxial accelerometers and borehole camera surveys to detect the frequency of blast malfunctions. The variety in stope and blast design parameters have allowed for a detailed comparison to be made regarding the frequency of malfunctions related to the size of the blasts, the type of detonators used, the type of explosive used, the relative in-situ stress of the stope, and the number of explosive decks used in the blast designs. The investigations into the malfunctions have found that the sequence of explosive performance typically is initiated by successful charges, followed by partial energy charges, followed again by failed charges. It was also discovered that single charge boreholes have a greater explosive performance success rate than multi-decked blast designs.

Keywords: Blast
Creighton
Explosive
Malfunction
Advisor: Mohanty, Bibhu
Mechanical Design and Development of a Modular Drag Sail for the CanX-7 Nanosatellite Mission

The drag sail developed for the CanX-7 nanosatellite mission is an aerodynamic deorbiting device suited to small spacecraft. The drag sail enables spacecraft within a range of bus and orbit properties to comply with international regulations that require newly-launched satellites to be removed from low Earth orbit after their end of mission, with the intent of reducing the rate of orbital debris formation. The overall design uses a modular approach that enables integration with two existing spacecraft busses, and also allows for distributed mounting on notional busses yet to be designed. Additive fabrication allows for complex part geometry that enables the drag sail components to be compactly stowed within a small volume. A model of the deployment mechanism dynamics in terms of basic design parameters reproduces a simplified picture of the operation of the real system at room temperature.

Keywords: Deorbiting
Drag sails
Nanosatellites
Spacecraft
Advisor: Zee, E Robert
Notch Signaling Mediates Tumor-CAF Crosstalk in Basal-like Breast Cancer

Increasing evidence indicates the importance of the tumor microenvironment in cancer progression. Cancer-associated fibroblasts (CAFs), in particular, have been reported to support tumorigenesis by promoting cell proliferation, invasion and angiogenesis. However, the mechanisms by which CAFs and tumor cells, specifically the basal-like subtype of breast cancer (BLBC), interact with each other, remain unclear. Interestingly, BLBC tumors are characterized by activation of the Notch pathway. Here, we performed co-cultures of BLBC cells with CAF-like fibroblasts and investigated the role of Notch in these interactions. We showed CAF-derived TGFb drives tumor Notch signaling and expression of the Notch target uPA. Notch activation also drives expression of c-MET which is required for uPA expression. Supporting functional assays suggested CAF-like cells promote invasion of MDA-MB231, in a fashion that depends upon TGFbR1, c-MET, uPA and Notch. Therefore, Notch participates in tumor-CAF crosstalk in BLBC cells, and may represent an important target for cancer therapy.

Keywords: cancer-associated fibroblast
Notch signaling
tumor microenvironment
Advisor: Reedijk, Michael
Information Out in the Cold: Exploring the Information Practices of Homeless Queer, Trans and Two-spirit Youth in Toronto

This study examines the information practices of homeless queer, trans and two-spirit youth living in Toronto. As part of this exploratory ethnographic study, semi-structured interviews where conducted with 11 youth who are currently homeless or have been homeless in the recent past. Data was also collected through participant observation at a Toronto drop-in program that supports homeless queer youth between the ages of 16 and 29. The ethnography provides a description of their habits regarding information seeking, sharing and use. The data introduces a wide range of needs relating to sexual or gender identity, housing, safety, sex work, harm reduction, creativity and performance, education, relationships and leisure. It also introduces key information sources including friends and peers, shelter staff and drop-in workers as well as practices such as texting, using university libraries, and the use of social media sites like Facebook and Craigslist.

Keywords: Homeless youth
Information practices
queer
trans
two-spirit
Advisor: Hartel, Jenna
X-ray and Magnetic Resonance Imaging (MRI) Fusion for Cardiac Resynchronization Therapy (CRT)

Cardiac Resynchronization Therapy (CRT) can effectively treat left ventricle (LV) driven Heart Failure (HF). However, 30% of the CRT recipients do not experience symptomatic benefit. Recent studies show that the CRT response rate can reach 95% when the LV pacing lead is placed at an optimal site at a region of maximal LV dyssynchrony and away from myocardial scars. Cardiac Magnetic Resonance (CMR) can identify the optimal site in three dimensions (3D). 3D CMR data can be registered to clinical standard x-ray fluoroscopy to achieve an optimal pacing of the LV. We have developed a 3D CMR to 2D x-ray image registration method for CRT procedures. We have employed the LV pacing lead on x-ray images and coronary sinus on MR data as landmarks. The registration method makes use of a guidewire simulation algorithm, edge based image registration technique, and x-ray C-arm tracking to register the landmarks and maintain correct alignment.

Keywords: Cardiac intervention
Cardiac resynchronization therapy
Image registration
MRI
X-ray
Advisor: Wright, A Graham
Identification of Cancer Susceptibility Loci by High-resolution Cancer Gene Microarray Analysis

Li-Fraumeni syndrome (LFS) is a highly penetrant familial cancer syndrome associated with inherited germline mutations in TP53. However, a causative gene has not been identified in ~25% of LFS and many LFS-like families. In this work we aim to discover possible candidate genes that contribute to the highly penetrant cancer predisposition observed in these families. We designed an ultra high-resolution CGH array to interrogate genes implicated in cancer. We detected alterations in genes such as MSH2 and PTCH1 which were successfully validated by qPCR. This also led to the detection of a novel substitution in a family by sequencing of PTCH1. Upon further investigation, we found that the proband harbouring the MSH2 deletion belongs to a kindred that satisfies the criteria for Lynch syndrome. Both the methodology and the results of this study can be expanded upon in the future to hopefully identify additional causative genes in LFS.

Keywords: Cancer Syndromes
Copy Number Variants
Genetics
Genomics
Microarray
Oncology
Advisor: Malkin, David
Effects of Nanostructured TiO2 Photocatalysis on Disinfection By-product Formation

The current research used simulated solar light and demonstrated that Aeroxide® P25 and innovative TiO2 photocatalytic nanomaterials decreased the trihalomethane (THM) and haloacetic acid (HAA) formation potential (fp) in model and natural river water sources by degrading natural organic matter (precursors) before disinfection with chlorine. A low and high UV dose (28 and 827 mJ/cm2 , respectively) were applied and, overall, synthetic water THM fp reduced by up to 41 % and HAA fp reduced by up to 36 % while Otonabee River water THM fp reduced by up to 24 % and HAA fp reduced by up to 13%. P25, P25 mixed with 1% of a silver-based product, anatase, and nitrogen doped anatase performed relatively similarly. Advancement in treatment efficiencies emerging from innovations in material science and reactor design, and understanding of water quality impacts and degradation mechanisms, increase the feasibility of incorporating TiO2 photocatalysis in drinking water treatment systems.

Advisor: Andrews, A Susan
Design of Engineered Bacteria for Regulated Phage Release: Progress Towards Targeted Elimination of Pathogens

Cholera outbreaks, caused by surges in pathogenic Vibrio cholerae, recur frequently in areas with water reservoirs around unsanitary living conditions. Phage therapy is being pursued as an alternative treatment to antibiotics. A seek-and-destroy circuit was designed for implementation in probiotics so that they could be used as a controlled delivery system for the phages. These engineered bacteria (EB) were designed to fulfill two functions: to regulate their own population growth and to respond to V.cholerae by lysing to release phages. In this study, it was confirmed that the E.coli strain K-12 could represent EB, since it could be induced to produce lambda phage virions. Construction of the seek-and-destroy circuit began by characterizing a lytic cassette, which showed promise as a population growth regulator and a prophage inducer. Finally, numerical simulations of a mathematical model representing the circuit implied that EB can successfully eradicate a V.cholerae population

Keywords: mathematical modeling
phage therapy
synthetic biology
Advisor: McMillen, R David
Influence of High-strength Reinforcing Bars on the Behaviour of Reinforced Concrete Nuclear Containment Structures Subjected to Shear

In the design and construction of complex, heavily reinforced concrete structures, such as nuclear containment structures, the use of high-strength reinforcement to replace congested patterns of normal-strength reinforcement improves constructability and concrete placement. However, the ACI Code 318-11 limits the usable yield strength of the shear reinforcement to 60 ksi, which means it is not possible to reduce reinforcement congestion by using high-strength reinforcing bars. To investigate the consequences of using high-strength bars on shear behaviour, twelve one-third-scale reinforced concrete wall elements with varying steel strengths and loading ratios were tested. It was determined that a significant benefit can be obtained by using high-strength steel reinforcing bars with yield strengths well beyond 60 ksi. The Modified Compression Field Theory was able to predict the full stress-strain response of all twelve members with a test-to-predicted ratio for the ultimate strength of 0.96 and a coefficient of variation of only 6.0%.

Keywords: compression tension axial
high-strength steel
nuclear containment
reinforced prestressed concrete
shear
wall
Advisor: Collins, Michael P
Bentz, Evan C
A Study of the Potential of Intel's Transactional Synchronization Extensions for Hybrid Transactional Memory

Hardware Transactional Memory (TM) attempts to deliver on the promises made with Software Transactional Memory by enabling scalable parallel execution with low programming effort. Intel's TSX is a recent such effort to provide hardware support for Transactional Memory on commodity hardware. This dissertation studies the limitations of TSX and proposes both manual and automated techniques for improving application parallelism. We find that using only TSX may result in high abort rates and poor performance for certain workloads due to hardware resource limitations. Using the Moldyn benchmark, we present a series of manual optimizations on TSX to achieve performance comparable to fine-grained locking. We then translate the identified manual optimizations into automated techniques in the form of a software-hardware hybrid transactional memory library called HyTM. Using a realistic benchmark, SynQuake, we experimentally show that HyTM can significantly increase the fraction of transactions that take advantage of TSX and execute in hardware.

Keywords: concurrency
parallelization
scalability
synchronization
transactional memory
Transactional Synchronization Extensions
Advisor: Amza, Cristiana
Shoreline Modification Impacts on Lake Ecology as a Result of Intensive Cottage Cluster Development

Sturgeon Lake located within the Kawarthas in Ontario is one of many freshwater lakes that are experiencing a transition from seasonal to permanently inhabited homes. This transition in development resulted in the intensification of clustering houses along the lake shoreline, impacting natural surroundings. This paper examines the ecological impacts housing developments have on lakes, examining the socio-economic impacts from the intensification of development. The goals of the paper are to examine the effects shoreline modifications have on lakes from cluster communities, to determine areas along Sturgeon Lake's shoreline that should be monitored to ensure that they are not further modified, and to bridge the gaps between management and sustainability plans for Sturgeon Lake's shoreline. Relationships were noticed between the type of housing, shoreline type, and type of roads in each development section. Increased habitation along the shoreline has resulted in increased nutrient discharge impacting the occurrences of eutrophication and algae.

Keywords: Cottage Development
Kawartha Lakes
Lake Ecology
Shoreline Modification
Sturgeon Lake
Advisor: Shear, Harvey