Faculty of Graduate Studies Online Theses
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Item Embargo EVALUATION OF PRACTICE TRENDS AND EXPLORATION INTO CURRENT AND NOVEL RETURN TO SPORT TESTING POST ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION(2024-12-04) Murphy, Chris; Not Applicable; Doctor of Philosophy; Faculty of Health; Received; Dr. Michael Hunt; Yes; Dr. Diane McKenzie; Dr. Scott Landry; Dr. Nathan Urquhart; Dr. Derek RutherfordFor those who rupture the anterior cruciate ligament but desire a return to sport (RTS), reconstructive surgery and rehabilitation is recommended. However, return to previous function is not guaranteed and for those who do, incidence of re-injury is high. This thesis aimed to i) understand RTS management practices of Canadian rehabilitation therapists; ii) to determine if knee biomechanics and muscle activation during a landing task differed between those post anterior cruciate ligament reconstruction (ACLR) and uninjured controls; and iii) to determine if these groups respond differently during a landing task when a surface translation is applied upon landing. Canadian practitioners do adhere to recommendations regarding RTS post ACLR. However, biomechanical evaluation identified at-risk patterns of movement in those post ACLR suggesting incomplete recovery, despite receiving clearance to RTS. Absence of change in movement pattern in response to perturbation suggests recovery of landing technique may yield more importance during RTS assessment.Item Open Access Investigations of Iron and Titanium Substitution into Nickel-Rich Cathode Materials by All-Dry Synthesis(2024-12-05) Macintosh, Macgregor; Yes; Master of Science; Department of Chemistry; Not Applicable; N/A; Not Applicable; Mark Obrovac; Erin Johnson; Michael Metzger; Mark ObrovacLi(Ni0.6Mn0.2Co0.2)O2 (NMC622) is a common cathode active material for lithium-ion batteries given its desirable balance of reversible capacity, cycle lifetime, and structural stability. Recently, strategies to maximize its cost efficacy have included employing dry syntheses to minimize manufacturing costs, limiting the use of expensive metals (e.g., Co), and using single-crystal (SC) particle morphologies to enhance long-term electrochemical performance. In this thesis, transition metal substitutions were performed in SC-NMC622 using dry synthesis methods to investigate performance-enhancing and cost-reducing mechanisms. The first work presented investigates the isovalent co-substitution of Fe for Co and Ti for Mn (i.e., Li(Ni0.6Mn0.2-yCo0.2-xFexTiy)O2) in NMC622 and its effect on the crystal and electronic structure, as well as the electrochemical performance. The second work focuses on the synthesis optimization of Mn-free, Ti-substituted Li(Ni0.6Ti0.2Co0.2)O2 (NTC622) initially explored in the first work. Overall, this thesis further expands the ability to perform all-dry compositional investigations in NMC622Item Open Access The Social Contract as an Ethical Theory(1982-08) Penrose, G. Brian; Not Applicable; Master of Arts; Department of Philosophy; Not Applicable; unknown; Not Applicable; Nathan Brett; David BraybrookeThe theory of the social contract was originally a political theory intended to explain certain aspects of the relation between state and citizen, including their respective duties and obligations to one another. It claimed that the state was justified because all citizens could and would voluntarily agree to form one , voluntarily since to do so was in keeping with their own self interest. This model has been recently utilized in ethical theory, particularly by David Gauthier, and tries to show that moral systems, too, would be formed by people for reasons of self interest. In this thesis I argue that contractarianism, both as specifically developed by Gauthier and in its more general descriptions, fails to adequately account for certain fundamental and reasoned moral opinions. The theory has an overly restricted criterion as to what counts as a moral issue, and it is overly restrictive in its selection of those who warrant moral consideration, leaving out, for example, animals, not to mention infants and severe mental and physical deficients.Item Open Access Public rules and the logic of natural language(1974-09-03) Pedersen, Roger A.; Not Applicable; Master of Arts; Department of Philosophy; Not Applicable; unknown; Not Applicable; unknown; unknownAs philosophers continue to develop a more comprehensive philosophy of language traditional philosophical distinctions will inevitably be cast anew. The following work might best be considered a critique of an oversimplified conception of the foundations and logical structure of natural language. More specifically three topics will be considered in relationship to metaphysical skepticism and the metaphysical distinction between appearance and reality: the nature of the foundations of language, the range of contingency in language, and the possibility of an analytic/synthetic distinction. The term "metaphysical", above, refers to any contention that our every-day ontology of material objects is more accurately expressed in terms of a language which makes reference only to our immediate experience, where material objects are taken to be non-sensible (empirically transcendent) entities, and not only to attempt to talk of such entities. The three topics mentioned above will each provide the focus of one of the following chapters, and will be organized respectively, around three rather Wittgensteinian themes. The first chapter will argue that no language can be established on a genuinely private foundation, the second deals with the manner in which the meaningful use of language is established publicly, and the third investigates the sense in which the rules which govern linguistic use are necessary.Item Open Access An Inquiry into the Nature of Resemblance with Particular Emphasis on the Notion of Pictorial Resemblance(1977-09) Thorne, Gary Wayne Alfred; Not Applicable; Master of Arts; Department of Philosophy; Not Applicable; unknown; Not Applicable; unknown; Robert MartinThe notion of resemblance has adopted many metaphorical senses and as a result has grown in language to become a very powerful and pregnant concept, a concept which deserves philosophical attention and clarification. Mere similarity in just any regard is insufficient for resemblance. Only sufficient similarity in some regard which is contextually indicated to be relevant , or in which the person making the judgement has interest, is sufficient . Two things need to be understood when a resemblance statement is made, and these will figure in truth conditions: (1) respects in which x and y are being compared; (2) comparison class. The statement 'x resembles y' implies that x and y share common characteristics, or that they are similar in certain regards; and also that x is much like y in these regards in comparison to other things in a specified class that x belongs to. Resemblance is a symmetrical, but is neither a reflexive nor a transitive, relation. Not all information is equally important or significant in judgements of resemblance. Two notions of pictorial resemblance ought to be distinguished, one which relies upon a literal interpretation of the concept of resemblance, and another which trades upon a highly metaphorical use of the notion. Artistic resemblance, the metaphorical application of pictorial resemblance, is often the goal of good artistic representation.Item Open Access The Lysocline and Calcium Carbonate Concentration Depth in the Sea(1971-08) Cooke, Robert C.; Not Applicable; Doctor of Philosophy; Department of Oceanography; Not Applicable; unknown; Not Applicable; M.J. Keen; K.E. Hayes; G.A. Riley; P.J. WangerskyAn examination has been made of the dissolution behavior of 100 ppm magnesium calcite in natural and artificial seawaters at pressures between 20 and 680 atmospheres. The behavior of the various systems indicates that the lysocline is partially a function of pressure and seawater composition, with magnesium and calcium concentrations dominating the composition variable. The lysocline and the compensation depth, which must be defined relative to a specific calcite and a specific seawater, are essential consequences of the transition between the pressure domain in which various magnesian calcites can be in equilibrium or steady-state and the pressure domain in which no calcite can be in equilibrium or steady-state. The presence of magnesium is shown to be essential for the maintenance of the lysocline and the compensation depth. The seawater composition effects have been investigated and further support the proposal that the system may best be described by phase rule. The role of salinity in seawater aggressiveness is discussed in terms of magnesium and calcium concentrations and how these affect the system both by being components of solid magnesian calcite and by being common ions.Item Open Access The Davies Chronicles : An African Merchant Family in Victorian Lagos(1983) Newman, Kenneth R.; Not Applicable; Master of Arts; Department of History; Not Applicable; unknown; Not Applicable; unknown; J.B. WebsterThis thesis examines the making and unmaking of the Davies family during the period from 1830 to 1920. The Davies were Saro Creoles, descendants of liberated Yoruba slaves who had been settled in Sierra Leone before returning to Yoruba, where they settled in Lagos. The thesis evaluates previous definitions of this cultural group and finds, through an examination of the institution of the family and its changes over time, that Saro culture was an extremely dynamic syncretism. It concludes that the various pressures for change operating on the group - political, economic, religious, sentimental and emotional - cannot be analysed separately. The primary purpose of the work is the historical reconstruction of one particular family through a narrative sequence of events. Within this framework, considerable attention is paid to various social and economic roles within the family - husband, father, wife, mother, provider, home-manager, child - and how its members responded to the obligations placed upon them. Particular emphasis is given to the way external pressures affected the internal dynamics of the family. The history of the Davies family is firmly placed in the context of the changing world economy of the nineteenth century, the rise and fall of the Creoles, the rise of British imperialism in West Africa, internal divisions and changes in Yoruba, and the origins of African nationalism. The work how the Davies family influenced these events and processes and how they, in turn, affected the family.Item Open Access Towards Sustainable Development and Peaceful Co-Existence: USAID and the promotion of Developmental Liberal Democracy in Post-Genocide Rwanda(2002-09) Thomson, Susan M.; Not Applicable; Master of Arts; Department of Political Science; Not Applicable; unknown; Not Applicable; unknown; unknownThe main argument of this thesis is that external actors, notably the United States Agency for International Development (USAID), can positively nascent democratic tendencies in African states where conducive internal political factors exist. In employing the case study of post-genocide Rwanda, the country-specific factors and forces that are currently working for, or against, . Rwanda's democratic experiment are explored. The Rwandan Government of National Unity (GNU) has clearly and coherently specified the terms and conditions in which external actors may participate in Rwanda's post-genocide reconciliation and reconstruction. In so doing, the GNU has created an enabling environment where the democracy promotion activities of USAID have facilitated the promotion of a Rwanda-specific variant of liberal democracy. In aggressively pursuing developmental liberal democracy as the basis of its reconstruction effort, the GNU has been able to consolidate impressive political, social and economic gains in assuring sustainable development and peaceful co-existence as the basis of Rwanda's future stability. Ultimately, then, country-specific factors, along with the financial support of USAID, have put Rwanda on the road to liberal democracy.Item Open Access Empirical Knowledge and Objectivity(1970-09) Murray, Priscilla; Not Applicable; Master of Arts; Department of Philosophy; Not Applicable; unknown; Not Applicable; unknown; unknownThere is, in the philosophical literature, a paradox which surrounds the discussion of the nature of physical reality and the possibility of our knowledge of it. Although there are many ways in which this paradox may be stated, in each case it is a result of an analysis of empirical knowledge into two components, such as, observation and theory, the given and the conceptual interpretation of the given, matter and form. In this thesis I show some of the reasons which have lent plausibility to those statements which make up the paradox, the impossibility of a satisfactory resolution of the paradox by the means of two proposed doctrines, and I suggest a possible solution of the paradox.Item Open Access A coupled physical-biological model of a warm core ring(1984-08-27) Franks, Peter J.S.; Not Applicable; Master of Science; Department of Oceanography; Not Applicable; unknown; Not Applicable; A.J. Bowen; R.O. Fournier; G. Flierl; J.S. WroblewskiA study was initiated to examine the questions: 1) Is the high phytoplankton productivity associated with warm core rings the result of a circulation associated with he frictional decay of the ring? 2) What is the relative importance of physical and biological factors in controlling production in and around the model ring? 3) Which is the more relevant grazing formulation for warm core ring plankton: that of Ivlev (1955) or that of Mayzaud and Poulet (1978)? Two biological models were formulated: a two box phytoplankton-nutrient model, and a three - box phytoplankton-zooplankton-nutrient model. The steady-state solutions of the P-Z-N model were similar with the two different grazing formulations, but the time-dependent behaviour of the two models differed markedly. The Ivlev model showed strong oscillations when the grazing pressure was high . The Mayzaud and Poulet formulation, which takes into account the changing maximum grazing rate as the zooplankton acclimate to surrounding food concentrations, showed only small, highly damped oscillations as it approached steady-state. It was felt that the Mayzaud and Poulet formulation exhibited more desirable behaviour, and was more appropriate for this model. This is the first mathematical exploration of the Mayzaud and Poulet formulation described in the literature.Item Open Access The response of a larval white hake population to the oceanographic regimes of 1974 and 1975 in St. George's Bay, Nova Scotia(1983-08) Fullerton, Anne Francesca; Not Applicable; Master of Science; Department of Oceanography; Not Applicable; unknown; Not Applicable; C.M. Boyd; J.A. Koslow; S.R. Kerr; M.M. SinclairDifferences in the biological and physical oceanographic features of St. George's Bay, Nova Scotia were established for 1974 and 1975. The biomass of particles <330um, suitable sized food for fish larvae, was greater in 1974. An initially high level in 1975 plummetted early in the study period after the passage of a tropical storm. Although the Bay warmed up 2 weeks earlier in 1975, temperatures were the same over most of the season. After establishing these oceanographic differences, responses in the larval white hake, tenuis, population were sought. Differences in the rate of warming appeared to be responsible for the earlier peak (2 weeks) of 1975 abundance curves for the neuston and lOm depths. The apparent consequences of the differences in the biomass of suitably sized prey organisms were more striking. Although the 6 morphometric measures of body form selected for comparisons showed no significant differences at the .01 level, larvae weighed more in 1974, the year of greater absolute food abundance, and had higher condition factors. Despite a larval abundance 1.5 times higher in 1975, subsequent recruitment by that year class to the fishery was very low. These results suggest the importance of measuring nutritional condition when using larval abundance as a predictor of recruitment since the period of high mortality occurs some time after early feeding.Item Embargo Analyzing the Protein Interactome of Lysine Methyltransferase G9a in Drosophila melanogaster(2024-12-05) Krupski, Jonathan; Not Applicable; Master of Science; Department of Biochemistry & Molecular Biology; Not Applicable; NA; Not Applicable; Dr. Graham Dellaire; Dr. Nicanor Gonzalez-Morales; Dr. Hyo-Sung Ro; Dr. James M. KramerG9a is a conserved lysine methyltransferase that catalyzes H3K9me2, an epigenetic mark associated with repressed gene expression. The goal of this research project was to provide the first in-depth characterization of the Drosophila G9a protein interactome. Several novel Drosophila G9a interactors were identified, encompassing various interactions conserved in mammals. Tissue-specific analyses revealed enhanced enrichment of Notch regulators in the mushroom body, indicating a potential mechanism mediating G9a’s function in this cell type. Proteins Scm and CG9932 were maintained as highly specific G9a interactors across cell types, indicating a novel G9a-Scm-CG9932 protein complex. Functional validations of these interactors suggest roles for Scm and CG9932 in the context of G9a activity in the fat body. Taken together, the findings of this project have greatly improved our knowledge of G9a’s interactions partners in Drosophila and in doing so have shed light on the molecular mechanisms governing G9a activity in these organisms.Item Open Access Exploring the experiences of Nova Scotian youth with mental health challenges participating in a physical literacy program: A phenomenological study(2024-12-04) Fulford, Alexander; Not Applicable; Master of Arts; School of Health & Human Performance; Not Applicable; n/a; Not Applicable; Dr. Michelle Stone; Dr. Sherry Huybers; Dr. Son TruongThe purpose of this phenomenological study was to explore the experiences of seven Nova Scotian youth (N=7) with mental health challenges (MHCs) participating in the Move2Improve (M2I) pilot program. The M2I program was a weekly 9-session community program based in Dartmouth (NS) designed to support the physical literacy (PL) development of youth with MHCs. Using qualitative methods, which included observations, journals, and a focus group, this research provides in-depth insights into the population’s unique experiences, while also offering valuable contributions to the emerging PL field. Overall, the M2I program was perceived as both enjoyable and engaging. Results indicate that the integration of diverse physical activities, as well as the program’s supportive and inclusive environment contributed to participants’ positive experiences. Moreover, findings suggest that most participants experienced slight PL improvements and socio-emotional benefits. Practical implications and future directions are further discussed.Item Embargo Regulation of Human Aldehyde Oxidase Expression by Retinoic Acid Receptor in MCF-7 Human Breast Adenocarcinoma Cells(2024-12-02) Allen, Erica; No; Master of Science; College of Pharmacy; Not Applicable; n/a; No; Kerry Goralski; Remigius Agu; Aik Jiang LauAldehyde oxidase (AOX) metabolizes various compounds, but its regulation is not well understood. Retinoic acid (RA) has two main isomers: all-trans RA (ATRA), which binds to retinoic acid receptor (RAR), and 9-cis-RA, which binds to RAR and retinoid X receptor (RXR). Although 9-cis-RA and RXR-selective agonists induce AOX1 in MCF-7 human breast adenocarcinoma cells, the role of RAR remains unclear. MCF-7 cells treated with RAR-selective agonists for 96 h showed increased AOX1 expression, which was concentration-dependent for the clinically relevant drugs ATRA and adapalene, as analyzed by real-time PCR. The pan-RAR antagonist AGN193109 or pretreatment with actinomycin D (RNA synthesis inhibitor) attenuated this induction. Targeted RARα knockdown by siRNA revealed partial regulation by this subtype. ELISA assay showed a disconnect between AOX1 mRNA and protein levels. These findings indicate that in MCF-7 cells, RAR regulates AOX1 mRNA but its role in controlling protein expression appears to involve additional regulatory mechanisms.Item Embargo Testing for Protein Composition-Dependent Variation of Recombinant Pyriform Silk Fibre Mechanics(2024-12-04) Macin , Berna Lalin; Yes; Master of Science; Department of Biochemistry & Molecular Biology; Received; n/a; No; K. Vanya Ewart; John P. Frampton; David N. Langelaan; Jan K. RaineyOrb-weaver spiders produce protein-based silks, including Pyriform silk which creates attachment discs and comprises pyriform spidroin 1 and 2 (PySp1 and PySp2). The recombinant pyriform spider silk proteins HPy1 and HPy2 are composed of a single repeat unit or a tandem-repeat of two units from the PySp1 repetitive domain from Argiope argentata, respectively. Previously, improved mechanical properties were observed for wet-spun HPy2 fibres of protein expressed in amino acid-supplemented M9 medium compared to LB medium, leading to the hypothesis that decreased mechanical performance was due to truncated HPy2. This thesis tests the effect of increasing amounts of truncated protein on fibre mechanics. Specifically, fibres were wet-spun using pure HPy2, two mixtures of HPy1 and HPy2, and pure HPy1. Tensile testing demonstrated that fibres formed with increasing proportions of HPy2 to HPy1 had improved mechanics. Conversely, protein secondary structuring was unaffected, with a transition from alpha-helix-rich to beta-sheet-rich states from solution to fibre regardless of protein composition.Item Open Access OPTIMIZATION MODELS FOR FRESH FRUIT PRODUCTION AND DISTRIBUTION(2024-12-03) TRI-DUNG, NGUYEN; Yes; Doctor of Philosophy; Department of Industrial Engineering; Not Applicable; Dr. Rene Villalobos; No; Dr. Claver Diallo; Dr. Michelle Adams; Dr. Tri Nguyen-Quang; Dr. Uday VenkatadriVietnamese dragon fruit leads the international market, accounting for over fifty percent of total production. 20%–15% of the dragon fruit output is consumed on the domestic market, while 80%–85% is exported. Asia, Europe, and the Americas constitute the primary consumer markets, wherein China contributes between 80% and 90% of the overall annual export value. Nevertheless, the production and distribution of dragon fruit encounter various uncertainties and risks, including but not limited to weather conditions, pests and diseases, fluctuations in market prices, challenges related to logistics and infrastructure, competition, escalating input costs, sustainability concerns, and export regulations. This thesis presents research on mathematical models that aim to analyze and enhance quantitative modelling approaches utilized in the complex decision-making process of dragon fruit cultivation, harvesting, and distribution in Vietnam. By incorporating both deterministic and stochastic models, these models provide a methodical and data-centric strategy to tackle these obstacles. As a result, decision-makers are empowered to make well-informed decisions, which in turn enhance operational efficiency, minimize expenses, and improve the overall performance of dragon fruit supply chain management. The decision-making process is structured into two stages: pre-planting, when costs and resources are considered deterministic; and post-harvest, when stochastic parameters become apparent. The decision-making process is divided into tactical and operational phases using the hierarchical planning approach, which is advantageous for cultivators, producers, distributors, and vendors. The thesis has accomplished three of its objectives: conducting a comprehensive literature review on mathematical models that concern the production and distribution of fresh fruits, evaluating and developing a deterministic optimization model with certain data, and devising a stochastic optimization model to address the coupling and complex effects of uncertain factors.Item Open Access In the Name of the Mother: Exploring the Experiences of Individuals with Matrilineal Surnames(2024-12-02) Herbert, Morgan; No; Master of Arts; Department of Sociology & Social Anthropology; Received; n/a; No; Dr. Lindsay DuBois; Dr. Laura Eramian; Dr. Liesl GamboldIn the Euro-American cultural context, surnaming norms for children are explicitly gendered: children born to opposite-sex parents typically receive a patrilineal surname, otherwise known as their father’s surname, and matrilineal surnames, or a surname one receives from their mother, represent a deviation from norms. While existing surnaming scholarship tends to favour the views and justifications of parents when it comes to choosing surnames for their children, this MA research explores the question of surnaming children from a new angle by illuminating the experiences of individuals with matrilineal surnames. Based on data collected from semi-structured interviews with 31 individuals who possess matrilineal surnames, I argue that matrilineal surnames are inherently disruptive kinship symbols in the North American cultural context. I show how matrilineal surnames unsettle North American gender relations, problematize cultural standards of stereotypical gendered parental roles, and unseat the sexist perception of the male birthright to nominal immortality.Item Open Access Universalization and Respect for Persons(1979-10) Meigs, Sandra; Not Applicable; Master of Arts; Department of Philosophy; Not Applicable; unknown; Not Applicable; Steven Burns; Richmond CampbellThis thesis is concerned to show that the notion of respect for persons as persons is essential to morality. Chapter I, based on an article written by Harry Silverstein, shows that any moral theory that is based solely on the principle of universalization fails in three ways. The underlying reason for such failures is that such theories lack a notion of respect for persons. Chapters II and III analyze the notion of respect for persons. Through this analysis and a discussion of empirical factors concerning self-respect,it is shown that respect for persons is desirable and reasonable. The Conclusion shows how a moral theory that is based on the notion of respect for persons can avoid the failures of moral theories that are based on the principle of universalization.Item Open Access Use of Tissue and Tumour Markers in the Histological Diagnosis of Tumours(1984-09) Om, Anil; Not Applicable; Master of Science; Department of Pathology; Not Applicable; unknown; Not Applicable; G. Rowden; J.H. Cooper; T. GhoseTissue and tumour markers may be of help in establishing the diagnosis of tumours. In this study I have evaluated the use of several tissue and tumour markers in the histological diagnosis of certain tumours. To be useful for the diagnosis of tumours, these markers should not only be tissue or tumour specific but they should also be stable under different conditions of cellular proliferation and after exposure to cancer chemotherapeutic agents. Therefore I have also studied the stability of 3 markers i.e. carcinoembryonic antigen (CEA), keratin and melanoma associated antigen (MAA) in M21 melanoma cells with different rates of proliferation in vitro and after exposure to two commonly used anti-cancer drugs, i.e. metho-trexate (MTX) and adriamycin. This work has been divided into 4 parts: {i) evaluation of the usefulness of anti-keratin and anti-CEA antibodies in establishing the epithelial origin of mammary duct carcinomas (DC), their lymph node metastases and pulmonary, cutaneous and uterine cervical squamous cell carcinomas (SCC), {ii) evaluation of the usefulness of anti-myoglobin, anti-desmin and anti-skeletal muscle antibodies (ASMA) in the diagnosis of childhood rhabdomyosarcomas (RMS), (iii) evaluation of the usefulness of polyclonal and monoclonal anti-melanoma antibodies (AMA) in the diagnosis of tumours of melanocytic origin, and (iv) evaluation of the stability of CEA, keratin and MSA under different conditions of cellular proliferation and after their in vitro exposure to MTX and adriamycin.Item Open Access Crustal Structures of Grenville, Makkovik and Nain provinces along the Lithoprobe ECSOOT Transect (Labrador) Determined from Seismic Refraction Profiles(1995-06) Fan, Jianming; Not Applicable; Master of Science; Department of Oceanography; Not Applicable; unknown; Not Applicable; Nick Culshaw; Ian Reid; Paul Hill; Keith LoudenThis thesis concerns a seismic velocity analysis of wide-angle reflection and refraction data combined with the LITHOPROBE ECSOOT marine multi-channel seismic reflection profile along the southeastern Labrador coast. The seismic velocity models of the Archean southern Nain, and the Proterozoic Grenville and Makkovik provinces obtained in this thesis are starting points for understanding the complete picture of crustal structures along the southeastern Labrador coast. These preliminary seismic velocity structures are used to place additional constraints on tectonic processes in this region.