ETDs: Doctoral Theses

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Midwives integration of manual vacuum aspiration for postabortion care in the Kinshasa and Kongo central provinces of the Democratic Republic of Congo
(Laurentian University of Sudbury, 2020-11-22) Bourret, Kirsty Marie
Illicit abortion in the Democratic Republic of Congo (DRC) results in the deaths of tens of thousands of women each year. There is great humanitarian potential for a return on investment if midwives are properly supported in integrating post-abortion care into their practice. In 2017, over 350 Congolese midwives were trained in the use of manual vacuum aspiration (MVA), an inexpensive and lifesaving post-abortion procedure. Yet, to date there is little understanding of its integration into midwifery practice in the DRC. The overarching aim of this thesis was to conduct collaborative research with the Professional Association of Congolese midwives (SCOSAF) in the provinces of Kinshasa and Kongo Central that would assist Congolese midwives to increase their practice of MVA, while modeling an equitable research partnership based on mutual trust and collaboration. The thesis has three chapters that build on each other and serve to demonstrate the unique substantive, methodological and theoretical contributions of the research. Substantively, the dissertation provides initial insight into those midwives who have integrated MVA post training compared to those who have not, as well as an exploration of those strategies used to successfully incorporate it into practice. Furthermore, the dissertation provides a model for conducting collaborative abortion research with midwifery associations and offers an advocacy tool that the midwifery association of SCOSAF can use to influence their expertise in midwifery led post-abortion care in the DRC. Methodologically, the dissertation introduces a novel combination of a mixed method case group comparison using a positive deviant approach. By applying a positive deviant assessment to the research, the dissertation provides a solution-based approach to uncovering the practical ways in which midwives can be supported in integrating post-abortion care into their practice. Lastly, the dissertation advances understanding of Congolese midwives’ integration of post-abortion care into practice through the proposition of a theoretical model that is aligned with regional knowledge.
Health equity and rurality in Northern Ontario
(2021-07-28) Scott (Spiro), Grace M.
Background: The current climate in Ontario, Canada is one where access to health and social services, healthcare experience and health/social outcomes vary widely across the province. The existing health disparities in Ontario disproportionately affect those living in rural and northern areas. Current indicators used to measure this variability have been developed in the context of health systems in more densely populated areas and may not be relevant for more rural and remote geographic areas. As such, the objectives of this thesis were: (1) to develop a health equity measurement approach specific to Northern Ontario based on input from Northern Ontario health decision-makers, and (2) to operationalize a rurality measurement approach for Northern Ontario. Methods: This two-phase exploratory sequential mixed methods study included a qualitative inquiry followed by a descriptive rurality measurement. The first phase explored health equity measurement in the context of Northern Ontario through in-depth interviews with Northern Ontario health equity key informants. The resulting thematic analysis informed a proposed Northern Ontario health equity measurement approach and the rurality stratifier exploration in phase-two. The second phase included a descriptive analysis using secondary data. The two rurality measurement approaches included were Statistical Area Classification Type and the Remoteness Index. Chi -squared tests for independence were used to assess the level of association between all classification methods including alternate categorization approaches within the Remoteness Index measure. Results: The thematic analysis in phase-one revealed four health equity indicators of relevance to Northern Ontario: infant mortality, overall mortality, perceived health status, and satisfaction of health care received. Furthermore, two stratifiers were identified as uniquely important to measuring health equity in Northern Ontario contexts. These two stratifiers included geographic position (rurality), as well as material welfare (income). The descriptive analysis of the rurality stratifier in phase-two recommended two methods of categorization using the Remoteness Index to consider as a complement or replacement to the Statistical Area Classification Type approach. Conclusion: This exploration of health equity measurement in the context of Northern Ontario proved to be a feasible and productive way to engage key informants in health equity indicator/stratifier selection and recommendation. Certain health equity stratifiers – including rurality – are elusive to define and measure; however, the Statistical Area Classification Type and Remoteness Index should both be considered as rurality measures in Northern Ontario.
The perceptions of women in Northern Ontario about their reproductive healthcare
(2021-10-15) Morgan, Lisa
With a goal to improve service provision, this study examined the experiences of women in Northern Ontario with respect to their uptake of reproductive healthcare services. As part of my mixed methods study, women in Northern Ontario completed a survey, offered in English and French, about their reproductive healthcare experiences, and a portion of participants were also interviewed. A multimodal recruitment strategy and maximum variation sampling was applied, with a goal of collecting the experiences of a diverse group of women. Analysis was based on 173 completed surveys and 19 semi-structured qualitative interviews. The interview data is grouped under five conceptual constructs, with “gender” as an overarching construct, found to be a factor in the remaining four: the characteristics of good care; the relationship with the provider; the care environment, and administrative practices. Additionally, respondents felt that midwives excelled at providing quality reproductive healthcare and would favour increased access to midwives for reproductive health care throughout their lives. For the survey data, I used descriptive statistics and multivariate linear regression models to determine whether residency, language, education, income, overall health, access to care, having a family physician, and preferring female providers (independent variables) were associated with the perceived quality of reproductive healthcare services and choosing a midwife. Most survey participants rated their reproductive healthcare experiences as fair to good overall but indicate room for improvement in the relationships with their providers and administrative support. Women residing rurally, without a family physician, and lower socioeconomic status are statistically more likely to prefer a midwife for reproductive healthcare. The survey results indicate a preference for female healthcare providers by the majority of interviewees. Changes driven by strong health policy may be required to engage women in recommended reproductive healthcare more fully. Although northern geography will always present challenges that may not be subject to amelioration, other factors preventing women from accessing care are more amenable to change, and as argued here, this is a right of women and an obligation on the part of governments to provide equitable access for all Canadians to healthcare services.
Impairment in mitochondrial oxidative phosphorylation alters clock gene expression
(2020-10-21) Baxter, Beverly Joan
Epidemiological studies provide evidence that workers who perform chronic night shift work are at significantly higher risk of a number of severe disease states including cancer. The perturbed activity/rest and feeding/fasting cycles, which occurs in persons performing shift work or who are subjected to jet lag, disrupt our normal 24- hour internal clock or circadian rhythm. The molecular mechanisms that link chronic circadian disruption to disease are not well understood. Since light exposure at night is known to decrease melatonin levels, some researchers have hypothesized that a reduction in the nocturnal levels of this pineal hormone predisposes individuals to disease. Animals that displayed atypical behaviours in their daily cycles, led to the identification of eight-key clock or circadian genes that are differentially expressed during the day and which determine normal internal timing. The expression of these genes was abnormal in a large number of human tumors including breast cancer. In this study, a temperature shift model was characterized and used as a means to synchronize the expression of these clock genes in a human breast cancer cell line. The model was compared to another cell synchronization protocol which utilizes serum shock and which showed differences in gene expression and cell cycle regulation between the two protocols. The temperature shift model was then used to study the impact of melatonin on clock gene expression and on the production of reactive oxygen species (ROS) in cells exposed to chemotherapeutic drugs. Melatonin influenced the cell cycle but did not cause significant differences in clock gene expression. Chemotherapeutic drugs differed in their effects on the production of intracellular ROS. A mitochondrial deficient (Rhø) cell line which exhibited impaired oxidative phosphorylation, was developed from MCF-7 cells. The profile of clock gene expression in Rhø cells that were also subjected to the temperature shift protocol was different than that of the parental MCF-7 line. This suggests that impairment of mitochondrial function disrupts clock gene expression and may be a link to the oncogenic transformation of cells.
Make(over): an integrated rhetorical analysis of masculine transformation in Disney animated film
(2020-11-04) McKee, Kristeen M.
This thesis analyzes patterned constructions of paternal, hetero-masculine heroism in three contemporary CGI animated Disney films: Wall-E (2008), Wreck-It Ralph (2012), and Big Hero 6 (2014). Wall-E the robot, Ralph the avatar, and Baymax the automaton, are maleidentified “artificial figures” who are positioned as inferior and insufficiently masculine because of their flawed physiques or social anomalies (Kakoudaki 2-3). Through processes of transformation, these seemingly unconventional males learn to present and perform their gender in ways that comply with hegemonic ideals of hetero, patriarchal masculinity. There are three main rhetorical strategies used in each film to map the male characters’ transformations. Juxtaposition, discipline, and reward are employed to project a set of ideals about gender, to correct deviance from these ideals, and to reward conformity. The artificial figures in the three films analyzed in this study reveal the latest trend in male-focused Disney animated makeover narratives. All three Disney animated films employ the makeover motif to reinstate dominant conceptualizations of masculinity despite occasional attempts to counter some of the male body types, gender role stereotypes, and male/female power dynamics found in previous Disney animated stories featuring male characters. Wall-E appears to be a fragile, dirty, broken lowclass labourer; Ralph is emotionally stunted and banished from his community; Baymax is fat, androgynous, and desires to care and nurture, which are traditionally “feminine” characteristics. However, although these animated films present slightly revised versions of masculinity by incorporating postfeminist characteristics into the narrative fold, as a whole, the films do not alter, in any significant way, conventional presentations of masculine physical supremacy, traditional gender roles, as well as patriarchal and hetero-normative structures. As my analysis demonstrates, it is more accurate to view these films as promoting the illusion of progress, particularly through the transformation narratives featured in each film. Thus, this dissertation answers a broad question about Disney’s masculine makeovers: what type(s) of male bodies and masculine roles are considered ideal according to these animated films? To answer this guiding question, I address the following sub-questions: how do the films through their visual, aural, and kinesic modes give preference to particular models of masculinity and how do these accounts of masculinity act upon audiences in a combined sensorialideological way? Drawing on concepts and methods from gender scholarship within Disney Studies, postfeminism (Angela McRobbie and Rosalind Gill), gender order theory (R.W. Connell), rhetorical criticism (Kenneth Burke), rhetorical materialism (Carole Blair), social semiotics and multimodality (Carey Jewitt), structural Marxism (Louis Althusser), cine-psychoanalysis (Laura Mulvey), cultural materialism (Mikhail Bahktin), and cultural studies (Stuart Hall), this study examines the symbolic choices and patterns used by Disney filmmakers not only to characterize the gender of their artificial figures but also to uphold particular idealizations of masculinity. The communication of ideology through film is not limited to the literal meaning of the narrative. It also occurs through emotional appeals enacted by the aesthetic elements of the films. The affective dimensions of these films and their capacity to instruct (in an ideological sense) and arouse (in an embodied, material sense) can shape the audience’s perceptions of gender and social relations. This study thus engages in a modified approach to ideological rhetorical criticism that accounts for the sensorial and affective dimensions of film. I call this method integrated for it attends to both the individual and collaborative functions of three symbolic modes: visual, aural, and kinesic used to promote hegemonic constructs of masculinity as well as to provoke embodied reactions in audiences that strengthen their identification with the characters and their makeover journeys. As a whole, this thesis uncovers how meanings about paternal, heteromasculine heroism emerge in the interaction of these three symbolic modes and what types of messages these films articulate, reinforce, or suppress to the embodied and emotionally-involved audience.
Profitability and organic farming in the province of Ontario
(2021-10-21) Ghoreishi, Yasser
This research intends to identify the fundamentals of organic farms' profitability structure in the Province of Ontario with an interdisciplinary focus, which includes small and medium-sized farms that provide organic food directly and indirectly through intermediaries to consumers. Hence, organic farmers need to remain profitable to stay in their non-profit-driven businesses and contribute to environmental sustainability, socially responsible farming and achieve its prosocial and pro-environmental goals. I used a questionnaire; consisting of four sections: company or farm-related information, general socio-economic questions, financial information for threeyear periods (2015 – 2017), and environment and public health-related information containing open and closed-ended research questions. First, I sent a hard copy of the questions and then collaborated with the Organic Council of Ontario and used the SurveyMonkey platform to increase the number of participants. My findings show that organic farm products are critical to enhancing the health of Canadians. Additionally, organic farming plays a vital role in protecting the environment by reducing soil erosion and water pollution, among other benefits, thus being critical to national development. It also was established that the government should ensure that the assistance offered to organic farmers reaches each farm and develops financial instruments to support the farmers. My Ph.D. thesis provides researchers with an overview of the profitability of organic agriculture in Ontario to inform future studies. In addition, it offers policymakers vital information applicable in formulating regulations towards boosting organic farming in Canada. Government support likely plays a role in the success of a lower-cost sustainable organic food system. My study established that politicians should ensure that the assistance offered to organic farmers reaches each farm and develops financial instruments to support the farmers financially. Finally, this research will be useful for farmers considering organic food growth, policymakers trying to determine whether organic farmers require subsidies, and scholars who would like to know more about the profitability structure of organic farms.
The engagement of the raising the Spirit’ Mental Wellness Team with First Nation communities in the Manitoulin, North Shore and Bemwijaang Tribal Council areas
(2021-08-31) Manitowabi, Susan Jane
The “Raising the Spirit” Mental Wellness Team (MWT) was funded as a pilot project in 2007. Funding for this project was made available by the federal government under the Mental Wellness Advisory Committee (MWAC) Strategy (see appendix 1). This pilot project partnered with ten First Nations communities from the Manitoulin Island, North Shore and Waabnoong Bemwijaang Tribal Council areas, in Northeastern Ontario. The goal of this pilot project was to work collaboratively with mental health and addiction workers and other service providers to improve access to specialized services; enhance knowledge, skills, and capacities of community workers; provide support, consultation, clinical supervision, coaching and mentoring; and, braid traditional and mainstream approaches to wellness. The focus of this research study was to evaluate how the MWT pilot project maintained the engagement and support of the participating First Nations communities. Areas explored included: the collaboration within and across Aboriginal communities; the integration of mainstream and traditional approaches; and, capacity building at the community level. Self -reflective journals, photovoice and narrative storytelling interviews were chosen because of their congruence with traditional ways of knowing and understanding which were also viewed as being culturally appropriate. These evaluation methods were extremely powerful means of telling the story of the relationship between the MWT and the First Nations communities involved in this project. One major contributing factor that enhanced the ability of the MWT pilot project to maintain the engagement with the First Nations communities was the strong commitment to the intent of the iv pilot project by all partners. Although there were many challenges that could have impacted the ability of the MWT to engage with the First Nations communities, there was good support from the First Nation leadership who recognized the benefits of enhanced mental health and addictions services in their communities. The pilot project offered an opportunity for the First Nations communities to access additional mental health and addiction services as well as increased access to traditional healing services. The Traditional Advisory Committee (TAC) was instrumental in creating opportunities through the Traditional Teaching Series for frontline workers to learn more about traditional healing practices and teachings. This had the added benefit of increasing their skills and abilities to utilize both traditional and mainstream approaches in their service provision to their clients, as well as themselves and their families.
SNO+ sensitivities to pre-supernova and supernova neutrinos
(2021-09-10) Rumleskie, Janet
Core-collapse supernovae (CCSNe) deposit heavy elements into the surrounding interstellar medium, affect the chemical evolution of galaxies, and lead to the formation of exotic bodies such as neutron stars and black holes. Neutrinos are also generated deep in the core of the CCSN over the timescale of tens of seconds and possess an imprint of the unconfirmed core-collapse mechanism. The progenitor stars to CCSNe also emit neutrinos in the final hours prior to collapse, albeit with an order of magnitude lower intensity and energy. A pre-supernova monitor and alert system was developed for the SNO+ detector based on inverse beta decay events. Such an alert will warn SNO+ and other neutrino experiments to maintain uptime to detect neutrinos from the impending supernova. Assuming the bestcase progenitor model, neutrino hierarchy, and background rates, the pre-supernova alert is expected to alarm for candidates as early as 100 hours prior to a supernova and up to a distance of 640 pc. Details of the construction and sensitivity of the pre-supernova monitor are presented within this thesis. The event rate from the next galactic supernova in SNO+ will depend on distance, but could exceed typical detector operating rates by an order of magnitude. The SNO+ data acquisition was stress-tested in this thesis with an embedded light injection source and compared to simulations characterizing the SNO+ detector’s response to CCSNe. These tests revealed SNO+ will experience data loss for any CCSN closer than 1.4 kpc. In addition, the SNO+ detector is expected to collect data from the neutronization burst of Betelgeuse before the data acquisition is overwhelmed. Using the detector simulations, a programmable laser diode was also prepared to emulate the light expected in SNO+ from supernova neutrinos. This light source is more dynamic and isotropic than the embedded source and will eliminate many of the uncertainties from the embedded source. It will be deployed in the future.
Geological, fluid-chemical and petrochronological studies of the East Kemptville Sn(-Cu-Zn-Ag-In) deposit and its Devonian host batholith (Nova Scotia, Canada).
(2021-07-21) Bickerton, Luke
Primary tin ores form in magmatic-hydrothermal systems related to highly-evolved granites enriched in lithophile elements (e.g., Li, Cs, Rb, U). Causative magmas are sourced from melting (or contamination by) enriched crust, or from melting hydrothermally-altered mantle. These granites form in large, multi-phase complexes (batholiths) and concentrate tin through fractional crystallization. The latter increases volatiles (H2O, F) in residual melts that are emplaced at shallow crustal depths, and thus the hydrothermal component to Sn-systems. Volatiles exsolve into aqueous fluids that contain soluble Sn2+. These fluids typically separate into highly-saline brines and vapours, and precipitate ore (SnO2) via oxidation of the Sn2+ . The fluids focus along fractures in the crust and their accumulation is dependent on fluid- versus lithostatic pressures. The northern Appalachian evolution included incremental emplacement of numerous batholiths and tin occurrences. The largest of these is the South Mountain Batholith (SMB) in Nova Scotia, which was emplaced deep in the crust; although is host to multiple evolved granites, the SMB contains only one significant tin deposit at East Kemptville (EK). To establish the depositional setting of EK at a greater crustal depth, this thesis analyses its geology and fluid chemistry as well as stable (O) and radiogenic (Re-Os, U-Pb, Lu-Hf) isotopes for both EK mineralization and the zircon minerals that represent the SMB. The study addresses the absence of other significant tin deposits in the SMB by evaluating the source of metal endowment. Due to its deep emplacement, the fluids at EK show no evidence of phase separation, yet abundant evidence of pressure-cycling. The latter allowed for replenishment of ore fluids during deposit formation; whereas initial tin formed via fluid-rock exchange, later ores formed from mixing with foreign fluids. This segmented hydrothermal evolution at EK is reflected by a range of mineralization ages. The zircon ages and chemistry indicate: 1) the SMB formed over 15-20 m.y. from altered mantle melts that underwent contamination by host rocks; and 2) the EK host is temporally and isotopically distinct from the SMB, and likely evolved from a lower crust-derived melt. The distinct source suggests other tin occurrences in the region share a similar origin.
Unraveling the potential for the novel agent, VR23, and its use as an anti-inflammatory for both acute and chronic inflammatory conditions
(2021-06-29) Durkin, Amanda
Inflammatory conditions continue to be on the rise in Canada, due in part to the increase in aging population. Although effective in some cases, the anti-inflammatory drugs that are currently available have their own pitfalls, with toxic side effects and being non-selective in their mechanisms of action. In an attempt to develop an effective anti-inflammatory drug, I have characterized VR23, a novel 4-aminoquinoline derived sulfonyl hybrid compound. VR23 was initially developed in our laboratory as potentially an effective and safe anticancer agent. Previously, data obtained from an in vivo study for its anticancer effects raised a possibility that VR23 might also possess anti-inflammatory property. In a nutshell, data presented in this thesis confirm that the hypothesis is correct. In the study, I used both acute and chronic inflammatory models. In Chapter 1, I have shown that VR23 is able to effectively down-regulate proinflammatory cytokines comparably to dexamethasone, a well-known anti-inflammatory agent. Specifically, VR23 was able to down-regulate IL-6 with great sensitivity. In rheumatoid arthritis cell models of chronic inflammation, VR23 demonstrated superiority over the anti-rheumatic hydroxychloroquine in its ability to regulate pro-inflammatory cytokines. In Chapter 2, I demonstrated VR23’s anti-inflammatory mechanism is likely through its prevention of the phosphorylation of STAT3, leading to a decrease in the production of its down-stream targets, IL-6 and MCP-1. Lastly, in Chapter 3 I describe the discovery that VR23 is rapidly metabolized into CPQ and DK23. CPQ is not an active compound with respect to its anti-inflammatory activity, indicating that it is a by-product of the VR23 detoxification process. On the contrary, DK23 possesses active anti-inflammatory property, as potent as VR23 at their respective IC50 concentrations. Data from an acute lung injury model showed that the anti-inflammatory activity of VR23 is comparable to that of dexamethasone, a well-known corticosteroid. Data obtained from the rheumatoid arthritis study showed that VR23 is much more superior to hydroxychloroquine, a commonly used anti-rheumatic drug. Overall, this study demonstrates the potential for the novel compound, VR23, to be used as a non-toxic specific anti-inflammatory drug to treat IL-6 driven conditions such as rheumatoid arthritis.
Effect of prenatal exposure to glucocorticoids and ionizing radiation on programming of adaptive behaviour and neural genetic dysregulation in adult offspring
(2020-07-23) Lalonde, Christine Nancy
Early life exposure to stress can lead to physiological and behavioural adaptations in offspring. Adaptive changes do not always benefit the organism, as it may result in adult diseases such as hypertension and diabetes in response to prenatal nutritional deficiencies. This thesis investigates the behavioural and genetic profiles of offspring exposed to two pathways of oxidative stress and DNA methylation: synthetic glucocorticoids and ionizing radiation. Synthetic glucocorticoids are able to bypass the placental enzymatic barrier and directly interfere with fetal gene expression by binding to glucocorticoid binding elements to either promote or inhibit expression as well as inducing changes in methylation of CpG islands. Ionizing radiation induces reactive oxygen species that will initiate DNA damage and oxidative stress leading to epigenetic modifications of gene regulation. The exposure to synthetic glucocorticoids induced adaptive phenotypical changes in Wistar-Kyoto offspring, inducing a stress-coping strategy and increased exploratory activity in combination with gene dysregulation in the prefrontal cortices. Exposure to ionizing radiation in C57Bl/6J mice did not induce significant behavioural changes; however, did elicit a few changes in gene expression in the prefrontal cortices, cerebral cortices, hippocampi, and cerebella that were sexually dimorphic. In contrast, the same radiation exposure study replicated in BALB/c mice induced extra-activity in offspring when faced with stress, arguably an adaptive response that may pose a risk to the animal. Significant gene dysregulation of oxidative stress and neuronal proliferation pathways was discovered in the prefrontal cortices, cerebral cortices, and cerebella of the BALB/c offspring. In consideration of the literature and the results of these studies, fetal programming of adult behavioural profiles may be accomplished through stress-induced genetic modifications.
Structural geology, tectonostratigraphy, and unconformity-related uranium mineralization of the Aberdeen Lake area, northeast Thelon Basin, Nunavut, Canada
(2021-06-04) Hunter, Rebecca Corrine
The Aberdeen Lake supracrustal belt is located alongside the northeast Thelon Basin in southcentral Nunavut. The belt hosts recently-discovered unconformity-related uranium occurrences, including the Tatiggaq, Qavvik and Ayra prospects. New geological mapping, structural analysis, whole rock lithogeochemistry, U-Pb zircon geochronology, and fluid inclusion analysis were conducted to interpret the stratigraphy, tectonic setting, and structural geology of the belt, and its uranium metallogeny. The revised lithostratigraphy of the Aberdeen Lake supracrustal belt consists of: 1) a ca. 2750 Ma Lower Sequence of komatiite, TTG (tonalite-trondhjemitegranodiorite) intrusions, and mafic gneiss; 2) a ca. <2687 Ma Middle Sequence of ca. psammopelitic gneiss, iron formation and a ca. 2680 Ma felsic gneiss; and 3) a ca. < 2650 Ma Upper Sequence of pelitic to psammopelitic gneiss with minor iron formation and arkosic gneiss. Transecting these Neoarchean supracrustal rocks are the ENE-trending Thelon and Judge Sissons faults, which record long-lived, dextral transcurrent movement with complex reactivation and fluid flow histories. A ca. 1830-1760 Ma initial faulting event produced damage zones consisting of multiple fracture sets, quartz veins and hydrothermal breccias, surrounding core zones of mosaic to chaotic breccias and cataclasites with dextral slip. A ca. 1760-1750 Ma epithermal faulting event comprises cross-cutting comb, crustiform-cockade, and lattice bladed quartz veins associated with Pitz Formation volcanism. Late reactivation events at ca. 1600-1300 Ma are expressed as irregular, fractures, non-cohesive crackle to mosaic breccias and gouges, which were the primary pathways for uranium-bearing hydrothermal fluids. The Tatiggaq, Qavvik and Ayra prospects are located between or along ENE- to NE-trending secondary faults associated with the Thelon and Judge Sissons fault zones. Steep-dipping fracture and non-cohesive breccia zones along these faults host most of the uranium mineralization within medial to proximal alteration halos characterized by strong clay, sooty sulphide and hematite. Fluid inclusion work suggests that a ≥300ºC, reduced, sulphur-bearing basement fluid acted as the primary reductant for uranium mineralization. This fluid was transported by fault-valve seismically-driven fluid injections into a large interconnected and reactivated fault system, which initially formed during dextral transcurrent movement along the Thelon and Judge Sissons faults.
Assessing the origin of some representative Archean-Paleoproterozoic porphyry Cu ± Au deposits
(2021-06-04) Meng, Xuyang
Most known porphyry Cu ± Au deposits are exclusively associated with oxidized and sulfurrich Phanerozoic arc-related magmas, but Precambrian analogues are rare. The genesis of some rare examples of such deposits (e.g., Tongkuangyu in Trans-North China Orogen) remains debated, and in particular, it remains unclear as to whether similar metallogenic processes that typify the Phanerozoic deposits also operated in the Precambrian. To resolve these issues, three study areas were chosen to variably characterize relevant aspects of these deposits in the context of porphyry-type metallogenies (i.e., the nature of mineralization, the redox states and volatile element abundances of the causative magmas): (1) the ~2.1 Ga Tongkuangyu deposit in Trans-North China Craton; (2) the ~1.88 Ga Haib porphyry Cu deposit, Southern Namibia; and (3) representative porphyry-type Cu ± Au deposits (Côté Gold, St-Jude, and Croxall) in the ~2.7 Ga Abitibi subprovince. At the Tongkuangyu deposit, remapping of the distribution of the host rocks, alteration, and mineralization support a porphyry-type model where ore formation occurred at ~2.1 Ga. This age is significantly later than the host granodiorite porphyry (~2.18 Ga) and schists (~2.5–2.2 Ga) and indicates that porphyry-type mineralization need not be linked directly to a causative magma exposed at surface. Instead, the latter is interpreted to be represented by subjacent porphyritic stocks and dikes. At the Haib deposit, the host calc-alkaline plutonic rocks and mineralization are dated to ca. 1886–1881 Ma. Estimations of magmatic fO2 and S, based on zircon geochemistry, apatite µXANES spectra, and apatite S analysis, demonstrate that oxidized, sulfur-rich arc magmas associated with porphyry Cu mineralization already existed in the late Paleoproterozoic. In addition, zircon Hf-O isotopes and whole-rock geochemistry support magmas of mantlederivation with minor crustal contributions that experienced amphibole ± plagioclase fractionation. These features of the Haib magmas are thus similar to those for Phanerozoic porphyry Cu deposits. For the ~2.7 Ga TTG (tonalite-trondhjemite-granodiorite-diorite)-related porphyry-type Cu ± Au deposits in the Abitibi subprovince, whole-rock geochemistry, zircon Hf-O isotopes, apatite S contents, and multiple oxybarometers suggest that variable magmatic origin and fO2 for the causative magmas. The rarity of porphyry-type Cu-Au deposits in these older settings may be attributed to either location restriction of these favorable metallogenic conditions and/or preservation, or exploration bias.
Exploration targeting for gold deposits using spatial data analytics, machine learning and deep transfer learning in the Swayze and Matheson greenstone belts, Ontario, Canada
(2021-05-19) Maepa, Mothepana Francisca
The rate of mineral deposit discovery has declined in the past decade despite increasing efforts from mining and government. The low rate of deposit discovery and the massive historical data available from brownfield exploration sites has prompted geoscientists to apply scale-integrated, empirical, and conceptual targeting approaches to exploration targeting. Applications of the mineral systems approach as a conceptual targeting method together with mineral prospectivity mapping has become the focus of predictive modelling for mineral exploration targeting. Evaluating the essential ingredients that make up a mineral system at various scales with data science machine learning tools could potentially help improve exploration discovery. This study was aimed at mineral exploration targeting gold deposits in the Abitibi greenstone belt using various spatial analysis, machine learning, and transfer learning methods. The multi-scale spatial analysis of gold prospects in the Swayze greenstone belt revealed orogenic mineral systems display fractal characteristics at regional and deposit scales, that gold prospects are clustered within 2 -4 km distances, and that clustering within camps can be attributed to the occurrences of lower-order fault densities or intrusive source rocks. Analyzing spatial correlations between prospect distributions and geological features was instrumental in identifying the physical controlling parameters at various scales, which were primarily D2 structures at regional scales and 2nd and 3rd order structures and competency contrast at prospect scales. Furthermore, the mineral prospectivity maps generated from the various machine learning methods such as support vector machines, random forest, radial basis function neural networks, and deep neural networks were not only beneficial in predicting prospective regions with > 80% accuracies but were essential for emphasizing important geoscience predictor layers that correlate well with mineral prospects. Deep transfer learning attempted for exploration targeting aimed at training a deep neural network model on the Swayze greenstone belt and using the learnt knowledge to make predictions of prospectivity on the Matheson region resulted in over 70% prediction accuracies. Deep transfer learning was valuable in showing that pre-trained models can be used to generate prospectivity predictions in relatively greenfield exploration site where the distributions of prospects are unknown. Overall, this study demonstrates that data integration and applications of data science tools is effective for exploration targeting today.
Observations of environmental interactions with the human organism
(2021-04-30) Vares, David A.E.
The recording and diffusion of ideas provides future generations of humanity the opportunity to further the advancement of understanding. This dissertation will begin the investigation of understanding ‘What influences of the Earth’s environment exist on human behaviour?’ The phenomena comprising the thesis involve the human organism, environmental stimuli, and societal customs. This investigation will consider the large degrees of variability due to the large number of interactions within the defined local environmental system. Review of research literature has introduced opportunity for identifying current limitations of the knowledge acquired. Novel interdisciplinary research is presented, including the relationship between the sun and earth, the ability correctly identify the human organism from background photon measurements, effects of population density on disease incidence, and the corresponding relationship between the sunearth interactions and the global behaviour of the human organism. The presented research accounts for the large degrees of variability between humans by utilizing global, big data analysis. The implications propose future health and well being awareness on a planetary scale.
Immune - modulatory effects of sidr honey: implications for anti-proliferative effects on cancer cells
(2020-10-23) Almnayan, Danah
Honey has become popular as a potential treatment for several ailments, including many cancers. Being a natural product, honey is often considered to be a safe and inexpensive adjunct or sometimes even an alternative to the currently available cancer treatments (including chemotherapy and radiotherapy) that have adverse side effects. Honeys from different parts of the world have shown anti-proliferative, immune-modulatory, and anti-inflammatory actions. Yemeni Sidr Honey (YSH) is a world-renowned honey whose anti-inflammatory activity suggests the possibility of underlying anti-cancer and/or immune-modulatory actions. Our studies have shown that treatment with 1% YSH is able to inhibit proliferation, and induce apoptosis in breast cancer cell lines (MDA-MB-231 and MCF-7) and cervical cancer cell lines (Hela). We also showed that THP-1 monocyte-like cells differentiated by treatment with phorbol ester and then treated with YSH affected their polarization into M1 or M2 macrophages: treatment with YSH for 24 h, enhanced the expression of the M1 phenotype while treatment of the macrophages with LPS and YSH for 48 h increased the level of M2 markers of differentiation. Further, co-culture of the M1 differentiated macrophages with breast cancer cells showed that treatment of the macrophages with YSH decreased tumour cell growth and increased apoptosis. These results suggest treatment with YSH is able to impact cancer via two separate mechanisms: direct impacts on cancer cell survival and activation of anti-tumour immune system (monocyte) activation.
Gold metallogeny of the southern Swayze Area, Abitibi Greenstone Belt
(2021-04-29) Hastie, Evan Carman George
Understanding ore forming processes and their control on mineralization is essential for the proper classification of Archean, and also younger, Au deposits and mineral exploration success. This study evaluates Archean Au-forming processes using examples across the Superior Province (Canada), with an emphasis on the Swayze area in the Abitibi greenstone belt. It combines detailed field mapping with various discriminants (e.g., in-situ stable isotopes, whole rock and trace-element geochemistry, LA-ICP-MS elemental mapping and chemistry of native gold) to differentiate between orogenic and intrusion-related Au deposits. Based on previous work and newly generated data on 44 deposits, the dataset suggests that Ag, Te and Hg are the only metals consistently associated with Au across different deposit types. Although these metals represent universal elemental vectors for Au exploration, other criteria such as rock and mineral textures, timing of Au mineralization, stable isotope data, and bulk geochemistry must be used to differentiate between Au-deposit types. An important finding is the recognition of a distinct subset of intrusion-related Archean deposits related to sanukitoid-type magmatism. These deposits, generally younger than 2690 Ma, predate shearing and are characterized by Te and Hg elemental associations, relatively high fO2, and δ34S ≤ -5‰. They differ from other intrusion related deposits in terms of their timing and geochemistry and, thus, require a different exploration strategy. Of importance to both academia and industry is the origin of late-stage high-grade Au zones in many deposits. This study suggests such zones result from coupled dissolution-reprecipitation of Au-bearing sulfides and generation of polymetallic Au melts and/or Au nanoparticles, which aggregate as coarse native gold. Both of the processes can elegantly explain ultra high-grade gold zones and are widely applicable to many Au deposits formed throughout Earth’s history.
Auditor professional skepticism – a cross-cultural study in the global International Financial Reporting Standards environment: the case of Canada and Brazil
(2020-03-19) McGillis, Sheila
The global financial reporting environment is undergoing significant change, with a global trend toward more countries adopting the International Financial Reporting Standards for public companies. Concerns exist as to potential barriers to harmonization, such as culture; therefore, it is important to draw on institutional mechanisms, such as auditing, to encourage compliance and harmonization. With this, there is a need to better understand the factors affecting the quality of such audits. Auditors’ professional skepticism is a key factor in ensuring audit quality. This exploratory quantitative study explores an area that is not well researched: specifically, the cross-cultural professional skepticism of auditors. Through a correlational design, the study provides insights as to whether auditors from different cultures make different skeptical judgments and decisions. This study also investigates whether prior research linking skeptical traits to increased professional skepticism in auditors is exportable from one culture to another. The major finding of this study is that there is no significant difference in the professionally skeptical judgments and decisions of entry-level auditors from Canada and Brazil. Culture is not associated with the professional skepticism of these auditors. The study also highlights that skepticism, as a trait does not correlate with professional skepticism of auditors across all cultures, specifically in Canada and Brazil. This study fills a major void in the literature concerning the study of cross-cultural professional skepticism and it extends prior research regarding the associations between skepticism as a trait and auditors’ professional skepticism by investigating auditors from two very different cultures. This study provides insights that are relevant to practitioners such as regulators, auditors and auditing firms, as well as academics in auditing, accounting, psychology and cultural studies.
Background reduction techniques and simulations for the PICASSO and PICO dark matter search experiments.
(2019-11-18) Scallon, Olivia
Dark matter is one of the most challenging mysteries of cosmology. The detection of Dark Matter is a main objective in modern experimental physics. The PICASSO and then the PICO experiments work towards the direct detection of WIMPs (Weakly Interacting Massive Particles) with superheated liquid detectors. Phase transitions in the superheated liquids are triggered by the nuclear recoil caused by the elastic collision of a dark matter particle. The phase transition in the detectors leads to the formation of a gaseous bubble. The acoustic signal of the nucleation of a bubble is recorded with piezoelectric sensors and pictures of the bubbles are taken with cameras. Many techniques are used to isolate potential dark matter signal from background signals. This thesis presents the work done for the fabrication process and purification techniques of the PICASSO detectors in the clean room at Université de Montréal. The detectors built with these new purification techniques allowed a background reduction of a factor of 10. The techniques and methods will be presented as well as the latest results from the data taken with these detectors. Simulations for the PICO experiment will also be presented. MCNP neutron background simulations from radioactive materials in the PICO detector will be presented. MCNP simulations for neutrons in the SNOLAB drift will also be presented as well as other MCNP simulations for the design and optimisation of the experiment. Finally, Geant4 muon-induced neutron simulations in the SNOLAB drift will be presented as well as Geant4 simulations for the design of a muon veto. These simulations were built entirely from scratch by using the SHIELDING physics list.
Metallogeny and characterization of late cretaceous superimposed porphyry Cu-Au-Mo and epithermal Au-Ag systems in the Dawson Range, Yukon, Canada: case study on the Klaza deposit
(2021-03-23) Lee, Well-Shen
The Dawson Range Gold Belt (DRGB; Yukon’s richest mineral district by resource) lies in the Yukon segment of the North American Cordillera and is dominated by Late Cretaceous (77–74 Ma) porphyry-epithermal systems. Mineral occurrences in the DRGB have seen limited exploration due to: (1) poor surface exposure; (2) incoherent classification of intrusive rocks; and (3) outdated exploration models. A multidisciplinary study utilizing: (1) field observations (drill core logging and mapping); (2) geochronology (U-Pb in zircon by LA-ICP-MS and CA-TIMS; Ar-Ar in muscovite; Re-Os in molybdenite); (3) whole-rock geochemistry; (4) zircon trace element geochemistry; (5) petrography (SEM-EDS, optical microscopy); and sulfide mineral geochemistry (LA-ICP-MS element maps) is designed to address the above challenges through a detailed investigation on the well-preserved Klaza deposit using 2011-2020 drilling data. Results suggest the presence of six intrusive phases of mafic to intermediate compositions. Intrusive activity occurs in four pulses spanning the Late Triassic to the Late Cretaceous. The Late Cretaceous magmatic pulse is protracted (80–65 Ma) and displays timedependant compositional changes. The youngest plutonic suites: (1) display enrichments in LREEs relative to the older suites; (2) are related to garnet-bearing sources (depleted HREEs, high La/Yb); (3) are hydrous (presence of hornblende-biotite); and (4) reflect a dynamic magma chamber (magma mixing textures). Two clusters of hydrothermal ages are constrained (ca. 77 Ma and ca. 71 Ma), correlating with Casino suite and Prospector Mt. suite magmatism, respectively. Higher temperature A-, B-and EDM-like veins are related to the 77 Ma event and cut by fault-veins related to the 71 Ma event. The fault-veins consist of four stages. Gold is hosted in early (Stage 2a, 2b) arsenopyrite and pyrite lattices and later liberated through late (Stage 2d) Copper-bearing fluids, whereas silver occurs later (Stage 2c) as native silver and sulfosalts. The Klaza system is best described as a porphyry-related intermediate sulfidation epithermal deposit superimposed on an older, unrelated porphyry system. Similar observations of spatial-temporal overprinting are documented throughout the DRGB (e.g., Casino deposit and Freegold Mt. district), suggesting these Late Cretaceous porphyry systems are linked to a fertile metallogenic event spanning 15 million years. This study is the first detailed characterization of Late Cretaceous porphyry systems in the DRGB and presents the first use of machine learning assisted paragenetic study of sulfide minerals for exploration and improving ore body knowledge.

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