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Characterization of the Hewitt Lake and Leta Arm groups, Indin Lake Greenstone Belt, Northwest Territories
Full text linkExposures of the Leta Arm (LA) group and southwestern Hewitt Lake (HL) group volcanic rocks in the northeast-trending 2670-2629 Ma Indin Lake Supracrustal Belt (ILSB) of the western Slave Craton were studied to understand their composition, petrogenesis and tectonic setting. This was achieved by integrating petrology, mineral chemistry, whole-rock geochemistry, U-Pb zircon geochronology, and Sm/Nd isotope analyses. Samples were collected through a combination of surface geological mapping and sampling of historic drill core from different lithologies within the central ILSB volcanic rocks.
The ≤2670 Ma HL group is amphibole-rich and comprises mafic and intermediate rocks of basaltic and andesitic composition whereas the 2668-2673 Ma LA group is pyroxene-rich and contains mafic through felsic units ranging from basalt to rhyolite. Alteration was mainly the result of metamorphic processes based on the abundance of ferro-hornblende, actinolite, carbonates, sericite, epidote and minor biotite, quartz, rutile and Fe-Ti oxides. Metamorphic conditions vary from greenschist to amphibolite facies and revealed an interplay of prograde and minor retrograde metamorphism based on amphibole chemistry and the textural relations with primary phases in the rocks. Metamorphism was regional and accompanied by plastic deformation resulting in the formation of high temperature microstructures.
Mafic tholeiites of the western HL and LA groups likely formed in an oceanic plateau based on their flat REE on primitive mantle-normalized spider plots, positive to minor Nb anomalies and low La/SmN values of <2. The eastern LA group basalts and felsic to intermediate rocks are characterized by LREE enrichment (La/SmN up to 5.47), positive Th anomalies, negative Ti and Nb anomalies as well as both positive and negative Zr-Hf anomalies. These characteristics are typical of arc-type rocks formed by metasomatism of a mantle wedge above a subducting slab. Low Gd/YbN values < 2.80 in both groups suggest melting at shallow depths in the absence of garnet, possibly suggesting an oceanic rather than continental arc setting. Positive ƐNd values suggest that the rocks did not interact significantly with older crust. The variable negative Nb anomalies in the arc rocks could be the result of crustal contamination or a subduction zone signature as slab-derived fluids stabilize Nb-bearing phases in the slab, leading to depletions of Nb in the metasomatized mantle. The Coterill tonalites may have been the source of contamination and the broadly similar age to the volcanic rocks would allow for modification of the whole rock signature without modifying the isotopic make-up of the LA and HL rocks.
Data from this study was used to revise the existing tectonic model for the ILSB volcanic rocks. The new model places the initial formation of the western basalts in an oceanic plateau which collided with a west-moving crustal block and clogged the subduction zone due to its buoyant nature with a new subductions zone forming behind the plateau. Arc magmas from the subducting slab erupted through and onto the plateau to form primitive arc tholeiites and the intermediate to felsic rocks observed in the ILSB
Development of small molecules targeting GPCRs (PAR2 and LPA1) for potential use in cancer diagnosis and therapy
No full textLung cancer continues to be the leading cause of cancer-related mortality for both men and women worldwide. Over the past two decades, advancements in prevention, screening, and treatment have contributed to reducing the overall cancer burden in Canada, though challenges remain. Molecular imaging, particularly PET imaging, employs radionuclide-labeled tracers to non-invasively diagnose diseases by visualizing biochemical processes in vivo. The success of PET imaging depends on radiopharmaceuticals targeting relevant receptors. G protein-coupled receptors (GPCRs) constitute the largest gene family in the human genome, regulating various cellular functions, with their dysregulation implicated in numerous diseases, including cancer. Protease-activated receptor 2 (PAR2) and lysophosphatidic acid receptor 1 (LPA1), both GPCRs, are overexpressed in lung cancer and play critical roles in tumor progression and metastasis, making them promising targets for cancer diagnosis and therapy. This thesis focuses on design, synthesis, and evaluation of small molecules that targeting PAR2 and LPA1 for potential use in cancer diagnosis and therapy.
Abnormal activation of PAR2 initiates downstream signaling pathways that promote cancer progression and tumor metastasis in various cancer types. Studies have shown that PAR2 is significantly overexpressed, up to 16-fold, in lung cancer tissues. Chapter 2 presents the design and organic synthesis of novel PAR2 ligands (total of 35 compounds), based on AZ3451, a previously reported potent and selective PAR2 antagonist. Collaborators from Western University evaluated all compounds for functional activity by assessing PAR2-dependent calcium signaling and β-arrestin1/2 recruitment. Based on the functional activity assay, structural modifications of AZ3451 are expected to yield novel biased PAR2 negative allosteric modulators (NAMs). Further assessment of all the compounds for bias in PAR2 mediated mini-G protein recruitment to evaluate all compounds for their therapeutic potential is under way. Among these compounds, a fluorine-containing compound, P1c, was selected as the candidate with an EC50 value of 16.8 nM (n=1) and 1.2nM (n=1), determined through β-arrestin 1 and 2 recruitment in a trypsin-induced assay. To facilitate the development of 18F-radiolabeled compounds targeting PAR2, a precursor SPIAd iodonium (III) ylide was synthesized and characterized. Ongoing efforts focus on investigating the optimal reaction conditions for 18F-radiolabeling.
LPA1 has been identified as being overexpressed in various cancers, particularly in lung cancer, where its activation promotes cell migration and invasion. Chapter 3 presents two series of design and synthesis of novel LPA1 antagonists with total 23 compounds. The synthetic scheme of first series is derived from the previously reported potent and selective LPA1 antagonist, RO6842262. The second series is derived from compound 12f, an anti-metastatic agent previously reported by our group. The core structure of this series was identified through scaffold hopping and molecular docking studies. All final compounds have been fully characterized, and their biological activity is currently being evaluated using cAMP and wound healing assays. Notably, compound L22p in the second series exhibited an IC50 value of 1.36 nM (n=1) in cAMP assay, indicating strong antagonistic activity against LPA1. This suggest that the novel scaffold holds promise as a potent LPA1 antagonist. Given the high expression of LPA1 in cancer, the candidate compound described in Chapter 3 will be converted into an iodo-compound, which will then react with SPIAd to generate iodonium (III) ylide precursors. These precursors will subsequently undergo treatment with fluorine-18 ions, followed by hydrolysis, to yield the radiolabeled final compounds
How two oral traditions teach for peace: commonalities in how oral Inuit and oral Islamic traditions teach for peace
Full text linkThis thesis conducted an empirical study to assess how oral Inuit and oral Islamic traditions teach for peace. The initial thesis was premised on two categories: I argue that within oral Inuit and oral Islamic knowledges are principles of peacekeeping and peacemaking. The first principle of peacemaking within both these traditions is self-temperance, or starting peace with oneself. This empirical study consisted of 5 interviews; 3 of these interview respondents identified as Muslim, while 2 interview respondents identified as Inuit. The interview results were presented through the lens of the Inuit Qaujimajatugangit (“IQ”) framework and findings, and discussion was presented after the data analysis. During the empirical research, the following findings were uncovered: all participants proposed a synonym for peace; that peace fosters and facilitates other virtues; that modelling is necessary to teach peace; that peace education requires strategic problem solving; and that learning from other traditions can augment our own peacemaking sbilities and help us better understand how religion influences our understanding of peace. Some of the lessons identified for school settings include the following: peace starts in the mind; the powerless can create and feel peace; peace requires acceptance of and promotion of diversity and plurality; peace should be taught through stories and oral traditions; and that, storytelling has to go hand in hand with modelling
Evaluating the linguistic coverage of OpenAlex: An assessment of metadata accuracy and completeness
Full text linkClarivate's Web of Science (WoS) and Elsevier's Scopus have been for decades the main sources of bibliometric information. Although highly curated, these closed, proprietary databases are largely biased toward English-language publications, underestimating the use of other languages in research dissemination.Launched in 2022, OpenAlex promised comprehensive, inclusive, and open-source research information. While already in use by scholars and research institutions, the quality of its metadata is currently still being assessed. This paper contributes to this literature by assessing the completeness and accuracy of OpenAlex's metadata related to language, through a comparison with WoS, as well as an in-depth manual validation of a sample of 6836 articles. Results show that OpenAlex exhibits a far more balanced linguistic coverage thanWoS. However, language metadata are not always accurate, which leads Open-Alex to overestimate the place of English while underestimating that of other languages. If used critically, OpenAlex can provide comprehensive and representative analyses of languages used for scholarly publishing, but more work is needed at infrastructural level to ensure the quality of metadata on languag
Water decontamination using magnetic biochar produced from biomass and mineral processing waste
No full textContamination from industrial wastewater is a serious environmental problem, often requiring innovative treatment methods beyond traditional technologies. This thesis explores the development of magnetic biochar (MBC), a carbon-rich, magnetically separable material produced by pyrolyzing biomass with iron sources as an efficient and sustainable solution for water decontamination. The research first reviews recent advances in biochar design, modification, and application for heavy metal removal, highlighting key factors like feedstock choice, pyrolysis conditions, and activation methods. In the experimental work, MBC was synthesized using different iron compounds and production methods. Among them, one-step co-pyrolysis of maple wood and FeO at 700 °C produced the most effective MBC for removing a model dye, Remazol Brilliant Blue R (RBBR), achieving nearly 100% removal under acidic conditions. Adsorption studies revealed that the process followed pseudo-second-order kinetics and fit the Langmuir isotherm model. Taking this a step further, a new approach was developed by co-pyrolyzing red mud, an industrial waste, rich in iron, with chemically activated biomass (treated with KOH and HNO3) to produce cost-effective MBC. The KOH-activated MBC demonstrated outstanding performance, achieving almost 100% removal of copper (Cu2+) and lead (Pb2+) ions from water, while also offering lower production costs compared to HNO3-activated MBC. Overall, this work demonstrates that properly engineered MBC materials, including those made from waste resources like red mud, offer a highly promising, low-cost, and eco-friendly solution for treating dye- and heavy metal-contaminated waters
Teaching through the tensions: dwelling in multiple accountabilities and responsibilities as a scholar-activist educator
Full text linkThis portfolio explores the experiences of a twenty-first century educator (myself) in my
role as a white settler educator working in a unique high school education model, in a diverse
urban context in Winnipeg, Manitoba, facing interlocking oppressive forces of capitalism,
colonialism, resource extraction, neoliberalism, and social inequities that make up the global
crisis of modernity. Through autoethnographic poetic inquiry, I examine how I embody my
accountabilities and responsibilities to/within my school context, and dwell in tensions between
conflicting accountabilities and responsibilities, as I simultaneously work within institutions that
perpetuate ongoing harms and injustices, and strive for anti-oppressive, culturally sustaining, and
ecologically resilient education. The chapters included in the portfolio are: (1) an introduction,
(2) a description of the research paradigm (based in relationality/relational accountability) and
methodology (autoethnographic poetic inquiry), (3) a literature review documenting the multiple
accountabilities and responsibilities that exist for teachers concerned with activism, climate
justice, and liberation in the midst of multiple global crises that threaten the well-being of people
and the planet, (4) a collection of original poems that document my lived experiences of dwelling
within the tensions, (5) a thematic analysis of the poems that critically reflects on commitments
and next steps, and (6) a conclusion. Through the thematic analysis, I found that naming tensions
such as whiteness, relationship to time and power, harm and violence can open spaces for deeper
engagement, and that commitment to meaningful practices is a critical way to train intuition and
instinct, allowing for an embodied praxis of connecting with the world, others, and myself as a
scholar-activist educator
Aerodynamic and flow structure analysis of iced wind turbine airfoil
No full textThe issue of icing on wind turbines presents a significant operational challenge, especially in
northern regions of Canada, where cold climates and harsh winter conditions prevail. This
buildup of ice increases mechanical stress on the turbines, potentially resulting in costly
maintenance and even operational failures. Ice formation alters the aerodynamic properties of
the blades, increasing drag, which can severely reduce performance, leading to energy losses.
Two primary types of ice profiles that occur in such environments are glaze and rime. In this
study, in the first section, the impact of two experimental ice profiles (glaze and rime) on the
aerodynamic characteristics of the NACA 643-618 airfoil are investigated and compared with the
clean airfoil. Large Eddy Simulation is used to do the simulation, at a Reynolds number of 137,000,
with angles of attack ranging from -10° to 10° with 5° step. Also, the aerodynamic characteristics
of a parametric ice profile on the mentioned airfoil are studied and compared with the clean
airfoil, in addition to two experimental ice profiles. The results indicate that the lift coefficient
increases consistently with the angle of attack across all iced airfoils. However, the drag
coefficient exhibits fluctuating behaviour due to the varying aerodynamic profiles caused by the
different ice profiles. Glaze ice significantly increases drag, particularly at higher angles of attack,
leading to a more pronounced reduction in aerodynamic efficiency compared to rime ice.
Furthermore, in all iced cases, the aerodynamic performance moves forward by 5° compared to
Base. The second section investigates the flow structures of glaze and rime and the comparison
with the clean airfoil at an angle of attack of 10°. Instantaneous flowfield data at the 30th-second
timestep is analyzed through flow visualization techniques, including streamlines, velocity
contours and Q-criterion iso-surfaces. Results reveal that ice accretion significantly alters
separation points, enhances flow instability, and accelerates the transition to turbulence. The
study also examines friction coefficients (Cf) to pinpoint separation and reattachment locations.
Furthermore, turbulent kinetic energy and Reynolds stress components are evaluated, showing
increased turbulence intensity and energy dissipation due to icing
The effect of land conversion from forest to agriculture on soil health indicators in rainy river, Ontario
Full text linkDue to changing climate and shifting crop zones, there is an opportunity for agriculture to expand in northern regions. This will require conversion of forest and scrubland to agriculture. Conventional methods of land conversion from forest to agriculture have resulted in a decrease in soil organic matter (SOM), which contributes to the maintenance of soil structure, water holding capacity, and a diverse microbial community within the soil. This degradation to the soil may result in a decline in soil health. Integrating wood mulch, which is woody material that would otherwise be removed from the site, might help reduce the degradation of soil health by retaining more SOM on site.
The objectives of this study are to: 1. examine the effects land conversion has on soil health by measuring indicators identified as responsive to land management practices, and 2. determine if the integration of wood mulch during land conversion can mitigate any declines in soil health. Methods for measuring the soil health indicator ‘wet aggregate stability’ were also explored in terms of sensitivity, cost, training, and time to complete the analysis. In June 2024 agricultural fields (n=27) and forests (n=9) were sampled in Rainy River, ON, to investigate the effect of land conversion on soil health. Eighteen recently (50 yr; cleared conventionally) were sampled for this study.
Soil health declined with land conversion, but the clearing approaches did not differ significantly from each other. Land conversion, regardless of timing of conversion, significantly reduced wet aggregate stability, carbon mineralization rate and soil moisture in 27 sampled agricultural fields compared to 9 referenced forest sites. Quantitatively, automated wet sieving was found to have the lowest coefficient of variation at 11.2%. This approach for quantifying wet aggregate stability did not show any significant effect of land conversion on aggregate stability. Volumetric aggregate stability tests (VAST) had a coefficient of variation of 17.5% and did show significant effect of land conversion. The SLAKES mobile application had a coefficient of variation of 15.4% and showed a significant effect of land conversion. Post-hoc test results differed for VAST and SLAKES. Qualitatively SLAKES was the most economical method with low training and time requirements. VAST was more expensive than SLAKES and required a similar amount of training as SLAKES but data collection was faster. Automated wet sieving was the most expensive and required more training and time to produce results.
SLAKES is recommended for future wet aggregate stability measurements of agricultural soils due to its high sensitivity to changes in treatments of agricultural soils, affordability, speed in results, and low training requirements. Land conversion degraded soil health and the only difference between approaches for conversion was for potential carbon mineralization, which was lower in the mulched soils. Based on the findings of this study, land conversion will degrade soil health regardless of the tested approach taken to mitigate negative effects
Reliability analysis of slopes with truncated quantile functions from small, truncated/censored samples
No full textTruncated and censored samples encountered in geotechnical engineering arise from various factors such as equipment limitations, formation characteristics, sample disturbance, unsuitable sampling methods, environmental conditions, human error, budget constraints, and geological complexities. In addition to this, unprecedented events like the COVID-19 pandemic can impede soil and rock sampling efforts, necessitating engineers and designers to work with truncated samples. The primary objective of the research is to explore novel approaches for probabilistic slope stability analysis and design under small, truncated/censored samples.
Landslides represent a prevalent and impactful geo hazard in Canada, particularly in relation to human lives and infrastructure sustainability. Thousands of landslides occur across Canada annually, resulting in direct and indirect damage estimated to range between 400 million per year. Reliability analysis, specifically utilizing the reliability index, serves as a valuable tool for evaluating engineering uncertainties, especially within the realm of slope stability. This study assesses the challenges posed by probability distribution limitations, emphasizing the relevance of truncated random variables in engineering contexts. The application of maximum entropy principles (MEPs) to estimating quantile functions (QFs) from truncated samples is discussed in the research. By employing MEPs along with partial probability weighted moments (PPWMs), the study demonstrates the effective estimation of truncated quantile functions. The optimization of these functions, determined by the Akaike information criterion (AIC), prevents the use of excessively complex models, thereby ensuring flexibility in model selection. [...
Drying of softwood kraft lignin and its cationic derivatives
Full text linkOur dependence on petroleum-based materials comes with significant environmental challenges
such as environmental pollution, including oil spills and air pollution. Furthermore, the utilization
of petroleum-based products leads to the emission of greenhouse gases, which contributes to
climate change. Additionally, many petroleum-based products, such as plastics, are not
biodegradable and accumulate in the environment, causing harm to wildlife and ecosystems. For
these reasons, researchers continue to seek out sustainable alternatives to petroleum-based
materials. Lignin is a promising starting material for producing sustainable and environmentally
compatible chemistries. Lignin is an abundant and sustainable resource. Organic synthesis and
polymerization reactions are utilized as effective methods for derivatizing lignin and tailoring it
for application in various industries. After synthesis and purification, drying is a crucial final step.
Generally drying conditions should be carefully selected to introduce minimal changes to the
properties of the synthesized products. Furthermore, there have been reports of lignin’s sensitivity
to heat, stimulating condensation reactions which alter the properties of the sample. There are no
comprehensive studies that investigate the topic of drying of lignin derivatives.
In this work, the objectives were to derivatize lignin in two ways via: 1) grafting reaction to create
a low molecular weight cationic lignin derivative and 2) polymerization to create a high molecular
weight cationic lignin derivative. [...