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Orogenic high-T granitoids of the central Grenville Province: characteristics and geodynamic implications
No full textConventional models of collisional orogens predict S-type granitoid emplacement during
the orogenic climax, whereas high-T (also known as A-type) granitoids, commonly associated
with mantle-derived magmas, are expected to form by late-orogenic extensional collapse.
However, the Grenville Province lacks significant syn-orogenic S-type granites, while high-T
granitoid bodies were intermittently emplaced in its hinterland throughout the duration of the
Grenvillian Orogeny. These rocks are particularly abundant in central Grenville, where they
intrude Mesoproterozoic Quebecia crust, in the granulite-facies mid and low-P segments of the
orogenic hinterland and are spatially associated with ~1.16–1.13 Ga anorthosites.
A review of a literature database shows that the high-T granitoids of the central Grenville
Province were emplaced intermittently in the orogenic hinterland between ca. 1086 and 1007 Ma
(with an apparent gap ~1042–1032 Ma) and are dominantly ferroan, metaluminous to weakly
peraluminous, alkali-calcic, with strong negative HFSE anomalies. In addition, a petrological and
geochemical investigation of samples from four granitoid bodies suggests crystallisation
conditions at ~5–6 kbar and ~800–1000ºC and variable oxidising conditions. Within-plate
transitional to arc-like geochemistry, oxidising ƒO₂ values, relatively evolved whole-rock εNd and
zircon εHf with Paleo- to Mesoproterozoic TDM suggest significant inheritance from the Quebecia
arc crust. The granitoids may have originated from the anhydrous, partial melting of the
intermediate, granulitic mid- to lower crust.
Irrespective of the magma sources, orogenic high-T magmatism over a span of ~80 Myr
reflects substantial mantle heat flux. The high concentration of these granitoids and the ~1.16–
1.13 Ga anorthosites in Quebecia suggests that orogenic magmatism is heavily influenced by
lithospheric structures inherited from the evolution of Quebecia in the pre-Grenvillian
Mesoproterozoic Laurentian margin.Includes bibliographical references (pages 103-115
Factors affecting covering behaviour in green sea urchin, Strongylocentrotus droebachiensis
No full textGreen sea urchin, Strongylocentrotus droebachiensis, is a major herbivore in the northwestern North Atlantic. It exhibits a poorly understood behaviour coined covering, where it picks up and holds material on its aboral surface. This behaviour is presumed to involve an energetic trade-off with movement and, therefore, must provide some benefit to the sea urchin. Past studies on this species found positive effects of ultraviolet radiation (UVR), wave action, and algal whiplash, and an inverse relationship with size, although there is a lack of consensus on these factors and mostly lab work alone to support these findings. The present study sought to further investigate the factors affecting this behaviour and possible interactions between them as well as to identify spatio-temporal patterns of the behaviour in the field. Two experiments were performed in an oscillatory wave tank to quantify the trade-off between movement and covering and to further investigate the effects of UVR, wave action, and sea urchin size on covering behaviour. Two field surveys were also conducted over time and depth to identify trends in the behaviour and see how storms may alter these trends. There was an inverse relationship between size and covering, but no effect of UVR on covering. Low to moderate wave velocities (0.1 and 0.2 ms⁻¹) induced covering in small sea urchins (1 to 2 cm test diameter), while only moderate velocities induced covering in large urchins (4 to 5 cm test diameter). The inverse relationship between covering and movement was also quantified in one experiment, with sea urchin movement decreasing by ~9 cm for every 10% increase in percent cover. The field surveys showed peak covering in July and August. Increased covering was observed at the sea urchin grazing front in summer months, followed by decreased covering at the front in the fall, corresponding to the formation and de-aggregation of the sea urchin grazing front. Overall, the present study can be used to establish a baseline of covering in relation to these factors (urchin size, wave velocity, and spatiotemporal variations) and could be used to evaluate how covering changes in the future with a changing ocean climate.Includes bibliographical references (pages 93-107
Exploring lived experiences of community Aquafit participation among older adults with chronic pain
No full textAquatic exercise has consistently been shown to be beneficial to older adults with chronic pain. The most accessible and affordable form of aquatic exercise is Aquafit, which is a group fitness class commonly offered at community recreation facilities. Despite their widespread availability, studies on community Aquafit programs have been limited. This study sought to address this gap by exploring the lived experiences of older adults with chronic pain who routinely participate in community Aquafit programs. This phenomenological study analyzed interview data from six participants from 65 to 88 years of age who attended Aquafit classes two to five times per week. Performing a thematic analysis of interview content yielded four major themes (1) “It’s a part of my chronic pain arsenal,” (2) “It’s a type of exercise I can actually do and enjoy,” (3) Impacts of organizations and facilities, and (4) “These relationships are precious… we are an Aquafit family, a support group.” Aquafit participation contributed to participants’ overall lifestyle by aiding in their pain management, facilitating active leisure involvement despite constraints, and expanding their social circle and support networks. Further, applying the model of selective optimization with compensation (SOC) to participants’ stories demonstrated the use of Aquafit as a way to continue active leisure involvement despite physical constraints. Overall, participants improved their quality of life through more than pain management, as demonstrated by the stories of perceived competence, enjoyment, friendship, and a sense of community support. Future qualitative research on community Aquafit classes is needed to better understand participant experiences with these popular programs. Further, this study was the first to explore community Aquafit participation as an SOC strategy. Therefore, additional inquiries into this relationship may facilitate a stronger understanding of aging and living with chronic pain
The burden of cardiac genetic disease in Newfoundland and Labrador: elucidating the pathogenicity and genotype-phenotype profile of a Ryanodine Receptor 2 variant- RYR2 p.Y4962N
No full textCatecholaminergic polymorphic ventricular tachycardia (CPVT) is a rare and potentially fatal inherited arrhythmia commonly linked to genetic variants in the Ryanodine Receptor 2 (RYR2) gene. This thesis investigates a Newfoundland family with suspected CPVT brought to attention after the sudden passing of a young individual carrying the RYR2 p.Y4962N variant. This variant was initially classified as likely pathogenic but was later downgraded to a variant of unknown significance (VUS) following updates to American College of Medical Genetics (ACMG) guidelines. A total of 655 family members were ascertained in the extended family pedigree across seven generations, with 93 individuals identified as being at 50% a priori risk of inheriting the RYR2 p.Y4962N variant. RYR2 p.Y4962N was identified in 33 individuals, with 27 individuals testing negative for the variant. Genetic status was unknown for 33 individuals. Four cases of sudden unexplained death (SUD) were identified within the family. However, comprehensive evaluation of the extended pedigree revealed no clear CPVT phenotype. Clinical assessments, including ESTs, ECGs, echocardiograms, and Holter monitoring, showed either no or mild abnormalities across both variant-positive and variant-negative individuals for all cardiac tests. These findings highlight the challenges of variant interpretation and raise the possibility that RYR2 p.Y4962N may be a benign or modifier variant. Functional characterization and investigations into a possible recessive variant may elucidate the genotype-phenotype relationship
Pandemic remittances: transnational exchanges before and during COVID-19
No full textThis study looks at the inflow and outflow of financial and social remittances in Newfoundland and Labrador, and explores how this network of exchanges was impacted by COVID-19. For this research, I undertook semi-structured interviews with 30 im/migrants that had moved to Newfoundland and Labrador, Canada, prior to the onset of COVID-19; I discussed with interviewees their remittance sending and receiving behaviours both before and during the pandemic. This study reveals that, faced with a crisis, transnational individuals living in Newfoundland and Labrador reconfigured their remittance exchanges in order to fill a humanitarian and development role. They sent more financial remittances, decreased their receipt of financial remittances, and engaged in sensitization messaging to promote positive behaviour change. Im/migrants also used their position to educate people in Newfoundland and Labrador regarding the unfolding crisis in other parts of the world, playing a key role in raising public awareness around international issues and, as such, contributing to global citizenship education in the province. The underlying driver for these transnational individuals as they engaged in this development role was relational, caring for others and recognizing the importance of social connections.
These roles mirror, in many ways, the approach of humanitarian actors in crisis situations: providing tangible resources, sharing sensitization messaging and engaging the public. This points to the holistic role that transnational individuals and their remittance exchanges play in the global development and humanitarian enterprise. Moreover, applying a Capabilities Approach (Sen, 1999; Nussbaum, 2011) to our understanding of development, we can see that transnational individuals are responding on an individual-level to the needs of friends and family as communicated to them directly. In this way, they are tangibly advancing the development goals of the people in their lives.
Existing development literature looking at remittances has narrowly defined their role in crises, often limiting this understanding to the inflow of financial resources to the Global South in times of heightened need. This study offers a holistic insight into the important role that transnational individuals play as developmental actors within the global development enterprise, of which the current literature has not given adequate attention
The archaeology of toxic heritage: novel approaches to understanding contamination and heritage in Labrador, Canada
No full textThis dissertation uses a novel approach to incorporate contamination and pollution as an
archaeological class of evidence, in Labrador, Canada. Although contamination from
human activity exists across Canada, northern regions hold many of the ~27,000 orphaned
or abandoned mines, 63 DEW Line sites, and military infrastructure from WWII.
Contemporary archaeological practice is only beginning to grapple with toxic
contamination despite the many disciplines, such as geography and history, already
confronting this issue. Filling this gap, this dissertation focuses on the archaeology of toxic
contamination from military installations in Labrador. Using traditional archaeological
modes of analysis, such as mapping, survey, and geochemical and statistical analyses, this
research not only shows the extent of contamination in Labrador, but also its everlasting
impacts on people, place and heritage. There are three manuscripts that serve as the body
of this dissertation, each one addressing a specific aspect of the project. The first
manuscript uses mapping and spatial analysis to illustrate the interactions between
settlements, heritage sites, contamination and the military in Labrador. The second
manuscript explores dendrochemistry applied within archaeology to investigate historical
and environmental contamination impacts. The final manuscript conceptualizes
contamination as heritage to leverage further archaeological inquiry into the
past. Combined, this body of work represents a new approach in archaeology integrating
dendrochemistry, spatial analysis, and applications of existing theoretical framing
Switchable biomaterials for wastewater treatment
No full textThe development of novel switchable biomaterials has gained significant attention
due to their potential in wastewater treatment, offering sustainable and cost-effective
solutions for contaminant removal. This thesis presents a comprehensive review of the
diverse applications of switchable biomaterials, including chitosan, polylactic acid
(PLA), cellulose, biochar, rubber, resin, and crude fibers. These materials exhibit
stimulus-responsive functionalities that facilitate recyclability and pollutant recovery,
making them promising candidates for environmental remediation. Despite substantial
advancements, challenges such as stability, recyclability, and performance
optimization remain. Future research should focus on improving these aspects while
exploring novel hybrid materials to enhance their applicability in real-world
scenarios.
Based on the research gaps identified by the literature review, the thesis work further
focuses on the development and optimization of a spiropyran-assisted cellulose
aerogel (CNF-SP) aerogel with UV-induced switchable wettability, and the evaluation
of its performance as an effective sorbent for oil spill cleanup. Beyond oil spill
remediation, the switchable properties of the aerogel hold great potential for broader
wastewater treatment applications, particularly in selectively adsorbing hydrophobic
and hydrophilic contaminants. The aerogel initially exhibited strong hydrophobicity
(124°) and showed UV-induced switchable wettability due to the photo-response
structure of spiropyran. Upon UV irradiation, the hydrophobicity of the aerogel could
be switched to hydrophilicity (31°), while visible light irradiation could restore its
hydrophobicity. The three-dimensional (3D) porous structure of the CNF-SP aerogel
combined with the hydrophobic properties of spiropyranol led to its great oil
adsorption performance (27-30 g/g of oil adsorption ratio). To systematically optimize
the material, the central composite design (CCD) was applied, as it allows for
efficient exploration of the interaction effects among multiple factors. The raw
materials, including carboxymethyl cellulose, carboxyethyl spiropyran, polyvinyl
alcohol, and nano zinc oxide, were specifically chosen due to their roles in enhancing
mechanical stability, responsiveness, and adsorption capacity. The optimized CNF-SP
aerogel demonstrated a high oil sorption efficiency, particularly in acid and cold
environments. Moreover, the switchable function indicated that the aerogel exhibited
reusability and renewability, with the added benefit of UV-induced oil recovery.
However, potential limitations, such as the scalability of the synthesis process and
real-world deployment challenges, remain key concerns that require further
investigation. Through the development of the CNF-SP aerogel, this thesis directly
addresses challenges in oil spill remediation by offering a material capable of
adapting to diverse environmental conditions while ensuring high oil adsorption
efficiency and sustainability. The study underscores the transformative potential of
switchable biomaterials in mitigating the environmental impact of water pollution,
reaffirming their role as a critical advancement in the field of wastewater treatment.Includes bibliographical reference
Stateless and suspect: Rohingya refugees under the regime of securitized nativism in India
No full textThis thesis examines the securitization of Rohingya refugees in India by integrating the philosophical (speech act) and sociological approaches of securitization theory. Employing media content analysis, it analyzes 179 English-language articles from the Indian media landscape to investigate the role of speech acts in constructing securitized narratives against the Rohingyas at the macro (national) level. Subsequently, the thesis conducts a case study of Jammu and Kashmir (J&K) to explore how these national-level securitizing narratives manifest and operate at the micro (local) level, within the region's distinct socio-political and historical context−particularly shaped by militarization and entrenched religious polarization. The thesis argues that the securitization of the Rohingyas in India is not an independent process, but rather a case of secondary securitization, shaped by their Muslim identity and their settlement in an already securitized space marked by anti-Muslim nativism
Adapting contemporary scientific research to school lessons: An exploratory study in northern Nova Scotia
No full textThis work demonstrates the process that I followed, and other teachers may follow, to identify and adapt current environmental science-related research to curriculum-aligned lessons. Conducted in northern Nova Scotia, course curriculum outcomes in a typical teaching assignment (Science 9, Science 10, Oceans 11, Chemistry 11) that could potentially be covered by adapting just one recent scientific publication are determined, representing all General Curriculum Outcomes (common to all NS secondary science courses) and 61 of the courses� 139 total Specific Curriculum Outcomes (course-specific outcomes). Following the design of lessons adapting this research, three local teachers voluntarily participated in reviewing/conducting the lessons, and provided feedback via semi-structured teacher interviews. Analysis of their responses identified five themes: Local Focus, Feasibility and Challenges, Opportunities Available, Inclusion Frequency, and Participant Appreciation, with four determined to be Major and Interconnected themes. The teachers were impressed by the many opportunities identified to address outcomes by adapting the selected article. They expressed the importance of considering local researchers and native species and ecosystems to encourage student engagement, and challenges (and solutions) to adapting research to lessons. Ultimately, after participating in this work, these teachers expressed plans to increase the frequency with which they incorporate research in their teaching
Code Red: methyl red functionalized metal-organic frameworks for pKa sensing
No full textMetal-organic frameworks (MOFs) are a class of highly porous material with customizable
topologies made from metal centers (often referred to as nodes) connected
via organic ligands (referred to as linkers). Given this, MOFs are useful for multiple
applications, such as, but not limited to, gas and aqueous storage, filtering, and
catalysis.
Given the expansive range of applications, one area of MOF chemistry that I
was interested in exploring was MOFs that change their properties when exposed to
stimulus. Specifically, I wanted to create a MOF sensor that would create a visual
change when a stimulus was sensed. A common method of visual indicators in general
chemistry is the use of azo indicator dyes for acid and base changes in solution. Methyl
red is a common azo dye with a pH sensing range of 4.4 to 6.2. In low pH, methyl red
takes on a deep red colour. In high pH, methyl red takes on a bright yellow colour. In
previous work, methyl red was integrated into MOFs in two different methods. The
first was by soaking the indicator into the pores of the MOF to detect the uptake of
CO₂, which formed carbonate esters within the pores of the MOF.
The second method of incorporating methyl red into a MOF was by postsynthetic
modification (PSM) of aminoterephthalate-containing MOFs using the diazotization
reaction. These MOFs have been shown to enhance the photocatalytic capabilities of
the parent system