ETDs: Master's Theses

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Muscle temperature influences oxygen uptake and blood flow during single leg isokinetic exercise.
(Laurentian University of Sudbury, 2020-12-02) McCue, Alexus
Thermal changes in muscle tissues (i.e: cooling and heating) modulate local oxygen transport from the muscle and into the cell. Whether a change in skeletal muscle oxygen transport subsequently regulate oxygen consumption (V̇ O2m) and tissue oxygenation (%TSI) during exercise is unclear. The purpose of this study was to assess the effects of skeletal muscle cooling and heating on muscle blood flow (Q̇ mus), V̇ O2m, and %TSI during single-leg isokinetic exercise. Eleven men exercised during 3-min intervals under thermoneutral (TN) condition, and localized muscle heating (HT) and cooling (CO), at 10%, 30%, and 50% of their maximal voluntary contraction (MVC). An occlusion technique combined to near-infrared spectroscopy was used to estimate V̇ O2m and Q̇ mus before and after exercise bouts. The results of this study showed that Q̇ mus was significantly increased in HT, while V̇ O2m was instead decreased in CO. Muscle temperature did not significantly change %TSI during exercise. Moreover, the relationship between Q̇ mus and V̇ O2m (TN: 0.173  0.101, CO: 0.187  0.0655, and HT:0.107  0.0413) was steeper in CO compared to HT (p = 0.009). In conclusion, this study demonstrated that muscle temperature regulates the blood flow/O2 consumption relationship during incremental isokinetic exercise.
The effects of YAP activity on retinoic acid signaling in the embryonic epicardium
(2020-12-17) Bongfeldt, Danika P.
Retinoic acid (RA), a metabolite of vitamin A, is primarily produced by epicardial cells and is required for the proper differentiation of epicardial cells into cardiac fibroblasts and VSMCs during heart development. Recent literature has suggested that both mechanotransduction, which is mechanical stimuli eliciting chemical responses within the cell, and the Hippo signaling pathway could potentially regulate RA-signaling. The transcriptional co-activator YAP is regulated by the Hippo-pathway and mechanotransduction and elicits changes in gene transcription through the TEAD transcription factor. Recently it was found that there were TEAD motifs in the Dhrs3 gene and YAP showed specific binding to the Dhrs3 enhancer via chromatin immunoprecipitation combined with qPCR (ChIP-PCR) in the mouse epicardial cell line MEC1. However, beyond its effects on the expression of Dhrs3 it is not clear if YAP actually affects RA-signaling. We hypothesized that YAP regulates retinoic acid signaling in embryonic epicardial cells. The first aim was to assess if YAP regulates the transcription of enzymes and receptors involved in RA metabolism or signaling in MEC1 cells. Using RT-qPCR we investigated the effect of constitutively active YAP, or conversely suppressed YAP activity on Dhrs3, Raldh2, RAR𝛽, Cyp26A1, and Cyp26B1 expression. To suppress YAP activity, a YAP small interfering RNA (siRNA), or the YAP-TEAD chemical inhibitor, Verteporfin, were utilized but these manipulations did not show significant effects on YAP targets, or retinoid receptors and enzymes in MEC1 cells. To overexpress YAP, a constitutively active form of YAP, YAP25SA, was transfected into MEC1 cells. We were able to confirm a direct relationship between Cyp26a1 expression and YAP activity as YAP25SA increased Cyp26a1 mRNA expression by 37.8-fold within 6 hours of transfection. As well, we were able to determine that YAP25SA affected Cyp26a1 expression through a TEAD mechanism; as co-transfection of YAP25SA with YTIP-GFP, a plasmid expressing a peptide that interferes with YAP-TEAD interaction significantly diminished the effects of YAP25SA on Cyp26a1 expression. The second aim investigated if YAP regulates the metabolism of retinol into RA by utilizing the two-hybrid Gal4-RAR;UAS-tk-Gaussia luciferase reporter system that estimate the amount of RA produced by monitoring the activation of the Gal4RAR reporter. Transfection of MEC1 cells with YAP25SA allowed more retinol to be converted to RA and for a longer period of time when compared to the control. Since the activity of YAP influences the expression of Cyp26a1 and metabolism of retinol, it was concluded that YAP activity plays a role in RA-signaling.
Freedom in play, as opposed to control in games
(2021-05-14) Soderman, S. Lowell
In this thesis I identify an important distinction: play per se is essentially free, whereas games per se are to the contrary essentially controlled. While free play and controlled games are regularly complimentary, I argue there can be rather substantive dangers when this distinction is variously confused, such that being free is wrongly understood as being controlled, or vice versa where being controlled is wrongly understood as being free.
High-fat diet-induced loss of muramyl dipeptide sensitivity
(2020-08-24) Williams, Laura Marie
Glucagon-like peptide-1 (GLP-1) is an insulin-stimulating hormone released from enteroendocrine cells. Muramyl dipeptide (MDP) is a peptidoglycan motif which has insulin- sensitizing effects in obesogenic mice by acting through the nucleotide oligomerization domain 2 (NOD2) receptor. We hypothesized that MDP enhances glucose tolerance by inducing intestinal GLP-1 secretion through NOD2 activation. We observed a significant increase in GLP-1 secretion when L-cells were treated with a fatty acid MDP derivative (L18-MDP). Additionally, we demonstrated NOD2 expression in mouse intestine and in L-cells. Two intraperitoneal injections of MDP (5mg/kg) significantly increased fasting total GLP-1 in chow-fed mice; an effect that was lost during the onset of hyperglycemia during a high-fat diet. No improvement in oral glucose tolerance was observed in MDP-treated mice. Finally, we demonstrated in L-cells that hyperglycemic conditions reduce NOD2 and GLP-1 mRNA expression. Together these findings suggest MDP may play a role in enhancing GLP-1 during euglycemia but loses its ability to do so in hyperglycemia.
Socioecology of the Midland Painted Turtle (Chrysemys picta marginata)
(2020-12-17) Rouleau, Carter J.
The cryptic nature of sociality in many reptile species suggests that their social behaviour may indeed be more complex and varied than previous research supposes. I propose that the Midland Painted Turtle (MPT; Chrysemys picta marginata) demonstrates cryptic social organization in its nesting and basking behaviours. In this thesis, I aim to: i) describe patterns of social organization in MPT, and ii) investigate influences on the social behaviour of MPT. In Chapter I, I investigate the potential for kin-bias in the communal nesting behaviour of MPT. I show that this bias is not present in MPT, and suggest that environmental factors and body size largely govern MPT nesting behaviour. In Chapter II, I investigate social organization in basking aggregations of MPT. I show that kin-bias is present in this behaviour. Further, I demonstrate that sex, body size, and capture frequency of MPT affect their social behaviour.
The rural industrial typology: resisting the imposition of the subdivision in Shelburne, Ontario
(2020-05-20) Jaekel, Bryce
The town of Shelburne is the second fastest growing town in Canada having nearly doubled in size since 2006.1 It is now facing an issue of housing that is common in rural communities in Ontario. The housing problem is multifaceted, the cost of owning a home is higher than its residents can afford, the homes are not supportive of a dynamic growing family, they lack efficiency, and they lack creativity. The irony of architecture in growing small towns is that there are conditions that require time and careful consideration to deal with, but there is a lack of economic means to put towards solving them. The application of funding towards residential architecture typically comes in the form of developer subdivisions and their primary concern is economic gain, using architecture as a commodity. The inflated market that allows these homes to be sold at this high price is outside the realm of intervention, however price and value are different things and value can be improved. This problem is larger than just economics, the introduction of these urban homes has changed the community fabric of these neighborhoods. The relationship between the individual and the community is dramatically different in urban and rural settings and this is reflected in the housing. In an urban and suburban setting the home is designed for privacy as the city is a centralized public realm where individuals go to interact with one another, then return to their suburban home or urban condominium where sanctuary awaits in the form of privacy. In sharp contrast to this, the rural landscape is designed to promote community interaction everywhere in the town, especially in its neighborhoods, which results in a different residential architecture. How can the single-family house be rethought for growing rural communities like Shelburne? By assessing the current contrasting elements of the typical rural home and the newly built subdivisions based on their Transparency, Ingenuity, Sustainability, and Personality. Taking into consideration the towns values to create a series of rural principles that reflect the essence of the town and applying them to future development. I intend to re-prioritize rural values instead of applying an urban design strategy, while still creating the density that growing towns demand. Focusing on a new proposed subdivision at the East end of town at the intersection of Highway 89 and Dufferin Road 124, and the return of an existing housing typology as benchmarks for improvement this project aims to create a new precedent for further development in town.
Emotional geographies: curating a relationship between grief architecture and the Niagara escarpment
(2020-06-08) Riehl, Jacob
Through the creation and development of one’s personal story, an individual pursues their beliefs and passions. The life of an individual is intrinsically shaped by the experiences defned by one’s place, relationships, and surrounding culture. However, the inherent duality of life and loss is often suppressed in the normalization of the pursuit of notions of happiness.1 Specifcally, this can be experienced upon the loss of a loved one, as one enters a state of grief: a psychological response to bereavement. This can lead to a state of melancholy which is a psychological experience caused by a subjective reaction to the emotional, physical, and cultural processes of bereavement. During grief, the well-being of an individual can deteriorate afecting the body, mind, and spirit. Often, a person in a state of mourning avoids social interaction due to pressing negative thoughts and emotions. Society can foster such unhealthy coping methods by encouraging private or psychological remedies that neglect regional, social, and cultural contexts.2 Arguably, dealing with negative emotions in isolation is not a sustainable experience, nor does it support the well-being of an individual. Exploring and understanding why and how people think, and respond to these situations in life has become a growing concern in organized psychology, resulting in an increased dependency on psychiatry.3 Humans are curious and we seem determined to understand ourselves as a species. From this, human experiences and conditions have been scrutinized and the emergence of grief as a topic worthy of psychological study solidifed, popularizing the understanding that normal occurrences and situations are part of medicalized psychiatry. The occurrence of grief has transitioned from a natural phenomena to a constructed theory, becoming a pathology to be monitored, managed, and treated by mental health professionals. Over time, psychologists have attempted to defne grief, arguing that grief is a transitory melancholy that afects everyone at some point in their life and that this experience interferes with day to day life, disrupting the ideal.5 The categorization of grief has led to the development of active processes that involve intense struggles to give up the emotional attachment to the loss, requiring time and energy on the part of the mourner in an attempt to prevent prolonged social or medical alterations for an individual. As a result, psychologists seek to defne the mourning process as they believe that bereavement contravenes the obligatory pursuit of happiness. It is apparent that grief theory has become decontextualized from experiencing one’s own emotions and has been completely psychologized. Having a place to explore the innate emotions of life is thus imperative to sustain the well-being of society. Supporting those disorientated by bereavement requires a shift away from the psychological realm, allowing grief to become an sensorial and experiential process for people to actively navigate together. This thesis proposes a means through which mourners are able to process their grief through a public built form. An interpretive experience can ofer a means to explore an individual’s grief by framing it in relation to the vulnerability of the landscape. The Niagara Escarpment is an underlying condition of the human experience that transcends time, boundaries, and culture, forming the construct of human life. However, due to the impact of the human species, this sacred entity is becoming endangered, causing society to collectively grieve its loss. The atmospheres embedded within the Niagara Escarpment can therefore act as a more comprehensive way to engage grieving individuals, aligning with the vivid emotions present in bereavement. Manifesting the thesis’ response in relation to the site’s atmospheres enables mourners to project, relate, empathize with, and be inspired by the landscape. Perceptions of vulnerability, remembrance, resiliency, and hope embedded within the site embody the emotions of bereavement to establish a therapeutic environment for people to navigate their own narrative. As a result, architecture can be recognized as a pedagogical means to curate grief as a living experience.
Re-establishing reciprocal relationships with the land: designing regenerative developments on Six Nations Reserve through the application of Haudenosaunce Ecological Knowledge (HEK)
(2020-07-31) McGee, Taylor
This Thesis pursuit explores how Traditional Ecological Knowledge (TEK) can inform sustainable land management and architectural development strategies that perform reciprocally with the land, forming harmonious relations with the natural environment. Situated within the Six Nations of the Grand River Reserve located in southern Ontario, the Haudenosaunee will be the cultural focus of the study. For the Haudenosaunee, maintaining a respectful relationship with Mother Earth isn’t just a lifestyle, it is a central component to their culture and identity, while serving as a necessity to achieving healthy minds, bodies and spirits. Although Six Nation’s Reserves built environment has been in fl uenced by settler culture and development. As a result, the environments aren’t conducive to Haudenosaunee value systems and promotes a hyper-individualistic ownership of property that produces segregated communities while allocating hardly any land for communal or recreational use or nature preserves. Titled ‘Re-establishing Reciprocal Relationships with the Land: Designing Regenerative Developments on Six Nations Reserve Through the Application of Haudenosaunee Ecological Knowledge (HEK),’ this Thesis pursuit revolves around utilizing Haudenosaunee Ecological Knowledge (HEK) in modern applications to inform regenerative strategies for sustainable design that reinterprets Six Nations current westernized built environment that is based on a colonialist method of developing the land. Through more of a land-based approach, regenerative systems will take advantage of natural processes of the land while enhancing and remediating the ecological conditions, producing environments that form reciprocal relations with the land. This land-based learning approach also begins both to question, as well as to think and re-conceptualize the current Six Nations gridalinear, westernized landscapes to better align with Haudenosaunee perspectives. The architectural vehicle for the exploration of employing HEK is through the design of a Land Based Learning Center with accompanying facilities of a Transitional Housing Center and the Elderly Care Facility. With the Land Based Learning Center serving as the programmatic anchor of the three architectures, the intent is to produce a regenerative development that achieves selfsufficiency and resiliency, centered around Haudenosaunee ways of keeping balance with Mother Earth in a contemporary context. In doing so, a new community development will be conceived that maintains reciprocal relationships with the surrounding ecology of Six Nations while developing infrastructures that empower the local community and promote self-determination. The intent of the Land Based learning center is to serve as a cultural and educational hub that operates both locally as well as across North America, serving as an outreach center for Six Nations community members both on and off reserve, as well as North American Indigenous people and enlightened mainstream individuals. The Center’s goal is to actively preserve and rekindle Six Nations connections with traditional values, teachings and ceremonies surrounding ecological knowledge and skill sets of harvesting and cultivating the land, while reinforcing the signifi cance of traditional knowledge in a contemporary context. The facility provides social, educational, and therapeutic programming that reinforce the signifi cance of maintaining close and respectful relationships with Mother Earth as a necessity to achieving healthy minds, bodies and spirits. In addition, the facility provides consultation services to home owners, builders, and developers both on and off the reserve as well as Six Nations Council on how traditional teachings and HEK can be reinforced in a contemporary context to inform sustainable land management and regenerative development strategies. Overall, the development of the Land Based Learning Center with accompanying housing facilities will inform Six Nations members and broader society on how to perform reciprocal relations with the land while actively reaching to increase the number of Six Nations members living on reserve by providing affordable housing for displaced Indigenous members.
Sensual building systems: a thermodynamic approach to urban public space
(2020-05-12) Jankovich, Marie
There is energy all around us, left unperceived by the senses. At the interface of the envelope, energy transformations are constantly occurring within the layers. For architectural design, these predominantly unseen energies affect perceptions of the exterior, and potential ‘felt’ experiences of the interior. The zones of energy that exist amongst the envelope should not separate the interior from the exterior, rather they should be seen as a transformative system of exchange between the exterior and the body within a thermodynamic space. In effect, this creates a zone ‘in-between,’ with various ergonomic conditions that can be felt by the body. Within the urban environment there is constant sensory overload. Preference is given towards natural environments for places of relaxation and well-being. Parks and green-spaces attempt to encourage comfort in the city, but the provided places rarely consider the dynamics of the seasons and the interactions between demographics. By filtering and modulating our perceptions of ‘energy,’ and the occurrence of microclimates, there can be a re-attunement towards the ways urban environments are perceived and experienced. The awakening of thermal perceptions can increase sensitivity to the ‘felt’ senses, tempering the visual, and promoting well-being through sensual building systems. In terms of sustainable design, common approaches rarely look at the provided support for the occupants’ well-being and the relationship between the body and the ‘felt experience’ of architecture. Sustainable practice tends to focus on quantitative factors rather than qualitative needs. With a lack of visual means and simulation technologies to understand thermal behaviour and the energy transformations that occur, sustainability has a difficult time advancing in terms of well-being and body comfort. Accordingly, there should be an alternative perspective on energy. Where energy is understood as a vital component to public space and the interactions between people and their experiences within the built environment. As the hub for Northern Ontario, Downtown Sudbury will be investigated, along with the need for urban public space under winter conditions. At the proposed Downtown site of 70 Elm street, the public space will engage the varied demographics, whilst providing an intriguing insight into designing with thermal energy. As a south facing pocket park condition, the public space will bring a thermally-rich engagement towards the senses, and serve to generate positive experiences, for a new perception towards urban environments. In turn, a more inclusive micro-culture will be formed through the incorporation of ‘energetic’ interactions, acting as a social and sensory therapy to destress and connect with others, and become more attune to urban thermodynamic surroundings. Experimentations with thermal energy and energy phenomena will be conducted to understand thermal radiation and laminar flow to ultimately create a range of potential ‘felt’ experiences amongst threshold spaces, suggesting activities for warmth or cooling. The method of thermal imaging will develop an understanding of material application and form, in terms of thermal conductivity and mass. The findings will lead to a knowledge of spatial properties, creating platforms with spaces that are thermally ergonomic and can be modulated for customized comfort. From the research into thermodynamics and the zone of concern being the ‘in-between’, the experiments will provide a translation of these interests to potential sensory experiences; enabling an urban site to be conceived for community healing and well-being.
Revisiting a traditional brick: a modern approach to an age old material
(2020-09-03) Feldberg, Jordan I.
This thesis will investigate robotically 3D printed bricks as a structural material to construct a funicular structure without the use of mortar or adhesives, and thus eliminate the need for falsework. The use of robotic fabrication processes will create bricks that yield less waste and provide greater effciency in the construction process. A new approach for a traditional brick will be investigated, using design and fabrication through digital architectural design. With the extreme changes in temperature and signifcant yearly precipitation in Sudbury, being able to get out of the environmental conditions is a necessity. Often wait times for buses can vary from 15 minutes to three hours, depending on whether it is a rural or urban area. A bus shelter that can be easily implemented will be designed specifc to site, using pre-fabricated 3D printed components that will interlock when assembled. Through the use of advanced manufacturing technology, processes to reduce embodied energy within a material and building strategy will be explored; introducing a new typology for the understanding of a modern brick and its potential. The process for geometry development will range from analogue explorations to digital geometry-based optimization techniques of form and fabrication. The robotic additive manufacturing of custom bricks, will inform the exploration of a funicular structure by enriching the known formal vocabulary of shell design, by way of advanced manufacturing processes. The brick is a building block used extensively in architecture. By expanding the manufacturing processes of traditional brick, a new ideology can evolve, one that combines natural materials with a funicular typology. This study refects contemporary technologies, while revisiting historical construction techniques for stereotomic stone and brick. It will further develop effcient design and fabrication strategies for a funicular structure, based on architectural and structural requirements and constraints. It will employ the use of computational design tools and form fnding methods to assist in the development of a funicular structure without the need for falsework.
The lake as a vessel for life: an architectural response to connecting leisure landscapes about the Muskoka Lakes
(2020-08-30) Bol, Shayne
Examining the anthropogenic change over the last two hundred years, Canada’s landscape at large has been molded into that of a globalized society. Often by means of the infrastructure that connects these economies, the people that drive them, drive upon the roads and make use of these same modes of transportation as well. The research will focus on the necessity of providing alternative modes of conveyance about the community at both the local but also provincial scales. As means of connecting urban civilizations become safer, faster and more efficient, our own vision of space and time trend towards that of a compressed reality[1]. A reality whereby one place is just as readily accessible to the average citizen as the next, as if distance and – with any luck – the emissions that coincide with traversing any given landscape are troubles of the past. Now, as we rely upon contemporary technology more and more to provide an immediacy of experience, that very experience estranges perceptions of landscapes and places that are not of their own corporeality[2]. Thus, the question is posed; what subverted intentions do people’s metaphysical preconceptions of one place, impose onto the next when engaging in true corporeality? In a period in which transient and trans-local lifestyles are colliding with those of domestic comfort across numerous temporal and spatial agendas. How then, do local populations perceive and interpret the globalization of space brought upon by these trans-local residents – daytime or seasonal – that are more often imposed upon localities rather than discussed? In a manner of collaboration rather than apprehensive co-existence, can local, year-round architectural programming begin to reimagine the vernacular practices within a given context, provided a history of translocality? Without affecting the landscapes that continue to facilitate these exchanges of people, knowledge, and economics amongst these different populations in an adverse manner, but rather instill a context specific sense of year-round resiliency? How might the design of civic spaces within these inherently trans-local destinations act as an inclusive space for all to experience? Extrapolating from the brief yet thorough history of Ontario’s cottage and lodging culture about the Muskoka Lakes. Colonial-European settlement has played a significant role in how the ethnography of rural and urban Canadian lives at large, have taken form – both in architectural and societal manifestations. Inadvertently, the privatization of lake-frontage within the Muskoka Lakes has been a subject of historic subversion and contemporary discussion since discovery. Still to this day, finding no sustainable resolve. On a seasonal basis, the area has become so saturated with an industry that depends upon the influx of non-permanent residents, such that it promotes exclusivity upon the lakes, as the further privatization of lodging ensues. Both, as the translocal “cottage” and archetypal Muskokan “resort” establish themselves as globalized commodity, rather than corporeal experience. In examining the past, with contemporary and historic modes of lodging upon the lakes acting as both access and destination, how can the reinterpretation of the architecture and social structuring of past resorts provide a new paradigm to act as precedent at larger scales, advocating for interconnected communities and landscapes. In that the implicit biases assumed by each of three populations – the local, trans-local, and day-visitor – trend towards solidarity and sustainability for all. The overt position that this paper will take is that of the apprehensive resident, concerned with the privatization of the Muskoka Lakes so that generations to come may transcend temporal constraint of travelling to and from the area to enjoy the rejuvenating, embodied experiences that this unique landscape provides those who reside upon it.
Give a Hoot: evaluating population augmentation efforts of the Western Burrowing Owl (Athene cunicularia hypugeae) in Canada
(2021-10-04) Pyott, Breanna Elizebeth
Migratory animals are a growing conservation concern and present unique challenges to population augmentation programs. Quantitatively evaluating and monitoring augmentation efforts is critical for conservation success. My research formally evaluated the success of two Western Burrowing Owl (Athene cunicularia hypugaea) population augmentation programs in Manitoba and British Columbia using survival, recruitment, and reproduction. Manitoba’s headstarting program holds hatching year (HY) owls overwinter taken from the nests of previous captive-released pairs. After being overwintered in human care, the HY owls are released in pairs as second year (SY) owls. British Columbia has a breeding and release program where owls are bred in facilities; their offspring are then held overwinter, paired and soft-released in the spring. Both programs soft-release SY pairs that lay clutches in the wild and young are referred to as “wild-hatched owls”. In British Columbia, wild-hatched owls returned significantly more than captive-released (ß = 1.05±0.29, p < 0.001). Holding animals overwinter may hinder accurate migratory behaviour. Fewer owls returned to release sites with more cropland (p = 0.049). Releases should be prioritized at sites with low percentages of cropland. Interestingly, individuals who returned from migration to form pairs and breed had significantly higher reproductive success than captive-released pairs (p < 0.001), suggesting effects of survivor-bias or mate choice. My thesis has identified opportunities to implement research with a priori hypotheses and data-driven management directions for the conservation of Burrowing Owls in Canada.
L-Carnitine Production in Pseudomonas fluorescens under phosphate starvation
(2021-09-30) MacLean, Alex
Glycerol is a by-product of the biodiesel industry and an important carbon source for bacterial growth. Phosphorus is an essential element in all living organisms and is utilized in numerous metabolic processes, such as the tricarboxylic acid (TCA) cycle and the electron transport chain. Without phosphorus, no organism can either grow or perform regular functions. In this study, we demonstrate that when the industrially-important microbe Pseudomonas fluorescens is deprived of phosphate, it elaborates a metabolic reconfiguration aimed at producing and secreting copious amounts of L-carnitine. To accomplish this biochemical adaptation, the organism bypassed the TCA cycle and utilized the glyoxylate shunt to generate a constant supply of L-carnitine through different metabolic networks. The upregulation of numerous enzymes including L-carnitine dehydrogenase (lcdH) and isocitrate lyase (aceA) mediated this process. The metabolic reprogramming triggered by phosphate may provide an effective means to transform an industrial waste into valuable L-carnitine.
Electrolytic destruction of cyanide on bare and MNO2 coated 304 stainless steel electrodes
(2021-09-15) Schmidt, Jacob
MnO2 coated lead and ANSI-304 stainless steel anodes were evaluated for use in electrolytic cyanide waste effluent treatment. Cyclic voltametry experiments revealed that MnO2 on lead was too resistive to be a feasible substrate. Cyclic voltammetry on bare and MnO2 coated steel shows evidence of cyanide destruction just prior to the onset of massive oxygen evolution, suggesting a reaction mechanism in which cyanide is oxidized via reaction with hydroxide radical species on the electrode surface. Galvanostatic experiments showed little difference in cyanide oxidation performance behaviour between bare steel and the MnO2 coating. However, copper ion were found to catalyse cyanide oxidation for bare steel, but had no observed effect for MnO2 coated steel. A cost analysis was done comparing electrolytic cyanide destruction using bare steel anodes to the INCO SO2/Air process. Electrolytic cyanide oxidation was concluded to have significantly lower operating costs, but is infeasible due to prohibitive capital costs.
The role of non-neuronal acetylcholine production in immune cells
(2021-10-01) Lachapelle, Maryse
The cholinergic system deals with the production, function, transport, and degradation of acetylcholine (ACh), a molecule commonly known as a neurotransmitter. This system has been shown to regulate inflammation via its resolution. Although increasing evidence suggests the importance of ACh in immune regulation, its role within specific immune cells remains inconclusive. Assessing the presence of cholinergic markers in immune cells in conjunction with their pharmacological inhibition will thus help to clarify the functional roles of the cholinergic system in the immune response. The aim of this study was to evaluate the role of non-neuronal ACh production in immune regulation. Expression studies using qPCR, western blots, mass spectrometry, and immunocytochemistry revealed the presence of ACh and choline acetyltransferase in immune tissues and within immune cells of such tissues. In addition, the effect of cholinergic inhibitors on immune function was examined on M1/M2 murine bone marrow derived macrophages (BMDMs) by examining their cytokine profile. Overall, inhibiting the synthesis of ACh seemed to significantly cause cell death in M1 BMDMs and non-significantly cause cell death in M2 BMDMs; yet other treatment conditions did not seem to cause cell death. However, due to pharmacological and statistical limitations, cytokine secretion profiles were generally inconclusive. These data further shed light on the role cholinergic system within immune cells, but further research would be necessary to validate these findings.
A retrospective analysis of the Vancouver Island marmot (Marmota vancouverensis) conservation breeding and release program: Conservation physiology and hibernation
(2021-09-28) Falconer, Sarah
The Vancouver Island marmot (Marmota vancouverensis) is an endangered mammal whose population is being recovered with a conservation breeding and release program. This involves management both in and ex situ, so it is vital to understand how the different environments are affecting the populations to maximize program outcomes. The purpose of this thesis was to retrospectively analyze data collected from this program to address questions relevant to population recovery. The first chapter compared the physiology of the managed populations using the neutrophil: lymphocyte ratio and found significant differences in this metric among targeted comparisons. The second chapter assessed factors that may be contributing to hibernation-related mortality of marmots during their first winter post-release. I found a combination of environmental and intrinsic factors influencing this mortality. Overall, this thesis contributes to a growing body of literature surrounding the efficacy of conservation breeding and release programs to recover critically endangered species.
Stress-induced transcription factors and their role in RNA disruption in ovarian cancer cells
(2021-05-20) Kay, Melissa
When cancer patients respond positively to chemotherapy treatment, their tumour ribosomal RNA (rRNA) is degraded, which has been termed RNA Disruption. The RNA disruption assay (RDA) has been developed to quantify RNA disruption as an RNA disruption index (RDI), which is the mass ratio of degraded to intact rRNAs. The underlying mechanism(s) for RNA disruption remain unclear. RNA disruption occurs in vivo and in vitro in response to various cellular stressors, including many structurally and mechanistically distinct chemotherapy drugs. Therefore, there must be a common pathway or mechanism occurring in each of these cases. Transcription factors are good upstream targets to begin elucidating a potential pathway or mechanism for RNA disruption, since they are major regulators of gene expression. The goal of this study was to: (i) identify transcription factors that are activated in response to treatment with agents known to induce RNA disruption, (ii) create enriched cytoplasmic and nuclear extracts from treated and untreated A2780 ovarian tumour cells, (iii) assess the relationship between stress-induced RNA disruption and activation/altered localization of stress-induced transcription factors in relation to RNA disruption. A2780 cells were treated with docetaxel or left untreated as a control for 8 hours, and nuclear extracts from these cells were prepared. The activation of a wide variety of known transcription factors in these extracts were analyzed using transcription factor activation profiling plate arrays. The activation was measured based on their ability to bind specific DNA sequences resulting in luminescence. Using a variety of criteria ranging from statistical significance to relevance to stress in the literature, a few transcription factors of interest were chosen: TFEB, TFE3, Nrf2, and YY1. Cytoplasmic and nuclear extracts were then made from A2780 cells after treatment with doxorubicin, docetaxel, thapsigargin, and starvation for 0, 2, 16, or 24 hours. The amount of RNA disruption was then assessed by RDA 72 hours after treatment with the same stressors. Treatment with doxorubicin, docetaxel, thapsigargin, and starvation resulted in significant change in RDI compared to control cells. Nrf2 was found localized in the nucleus with or without treatment. Thus, Nrf2 appeared to be constitutively activated in A2780 ovarian cancer cells, perhaps due to its role in cell survival. This study corroborates the results of another study (Investigating the Relationship Between the Activation of Transcription Factor Nrf-2 and Ribosomal RNA Degradation Upon Exposure to Various Cellular Stressors, Carly Zulich, 2020) and eliminates Nrf2 as a potential transcription factor associated with the activation of RNA disruption. Contrary to expected findings, there appear to be higher levels of TFEB and TFE3 in both the cytoplasm and nucleus of the untreated and DMSO vehicle control than cells treated with chemotherapy or other cellular stressors. Future studies could investigate the potential of other transcription factors as targets for elucidating the mechanism(s) for RNA disruption.
RNA disruption is a widespread phenomenon that is associated with cell death in tumor cells
(2021-10-19) Butler, Phillipe
A recent clinical trial found that chemotherapy-induced tumor rRNA degradation (RNA disruption) was associated with both pathological complete response (complete tumor destruction) and extended disease-free survival (DFS) in breast cancer patients treated with neoadjuvant chemotherapy. The RNA Disruption Assay (RDA) is a useful tool to quantify the magnitude of RNA disruption occurring within cells or tumors, expressed as the RNA Disruption Index (RDI), and is currently the subject of an international clinical trial. The purpose of this study was to investigate the phenomenon of RNA disruption in response to both chemotherapy agents and cellular stressors in the ovarian carcinoma A2780 cell line and the breast adenocarcinoma MDA-MB-231 cell line. Also, we assessed the relationship between RNA disruption and both cell death and RNase L expression using multiple cell viability assays and CRISPR-Cas9-mediated RNase L knockout clones, respectively. RNA disruption was induced in response to multiple chemotherapy agents and several cellular stressors, including oxidative stress, ER stress, protein translation inhibition and starvation. However, the induction and magnitude of RNA disruption was found to be both dose- and stressor-specific, and dependent on the cell line studied. Mycoplasma contaminations of host cell lines were also found to potentiate a markedly different RNA disruption banding pattern in response to chemotherapy. RNA disruption was also found to be associated with cell death, as significant increases in RDI values were observed for chemotherapy doses that induce partial or complete cell death, as measured by cell counting, and both cellular recovery and flow cytometry DNA content analysis. Finally, knockout of RNase L expression in the A2780 cell line did not affect RNA disruption, demonstrating that RNase L in not involved in the RNA disruption mechanism(s). Overall, these findings support the novel role of RDA as a tool for quantifying tumor cell death in vitro and in vivo.
Urban and rural homelessness in Northern Ontario: an Indigenous lens
(2021-09-10) Hendel, Isabelle-Gabriele
Indigenous Peoples are at a higher risk of experiencing homelessness in Canada than non-Indigenous Peoples. As a result, there is a disproportionate representation of Indigenous Peoples in the homeless population. Studies have been conducted in order to identify what services are needed for people living with homelessness in Canada. However, these have failed to include an Indigenous specific focus and have not included the perspectives of Indigenous people with lived experiences. Furthermore, the majority of previous studies explore homelessness in large urban settings and seldom focus on rural or Northern Ontario. A secondary analysis on a photovoice study completed in 2014 on homelessness in Northern Ontario was done to highlight the unique experiences and needs of the Indigenous participants from the previous study. This research focused on health impacts and service provision requirements surrounding Indigenous homelessness in four communities in Northern Ontario. A literature review was also conducted in order to explore the laws and policies surrounding the rights and legal responsibility for services in relation to UNDRIP and the TRC. All of the photovoice data represents lived homelessness or hidden homelessness experience, from the perspectives of Indigenous participants. These are their voices.
Architecture and affordance: a data driven and computational approach to the architectural analysis and design of buildings using affordance as a model of typology
(2021-06-22) Walker, James
ISpace syntax has long been used as a spatial analysis tool to graphically represent the relationships and connections between spaces. This has been used to promising effect in the past to compare buildings of a similar typology in order to better understand them. We can use the framework of space syntax and introduce affordances to gain a better understanding of how affordances of access, natural light, sound, and activity congregate in building typology. By building a digital sensor array and conducting an analysis of a particular building typology, we can start to find optimal patterns of affordance which exist within living buildings. The typology I am looking at for this thesis is the United Churches of Sudbury. Sacred space is a phenomenologically dense and interesting typology which lends itself to generating interesting data. United Churches as a typology also have a philosophy of shared multi-use space which lends itself well to this more generalized approach to understanding program through affordances. In this thesis, I look at four different case studies of United Churches, one to understand what makes a United Church, and three others as examples of typology and subjects for collecting data. The aim of this work is to use this data to develop a set of computational design tools that will eventually be used to suggest a possible design for a United Church on the site of Larchwood Memorial United Church in Dowling. Aside from site analysis, there are two parts to this affordance based process. Just like how Gibson distinguishes between affordances and the invariant properties of objects, I take stock of affordances through a set of affordance graphs and tables of relevant data from each of my case studies in Sudbury. I also look at the design solutions such as furnishings and building openings which these churches used to satisfy those affordances and document them in the from of a pattern language. Using the affordance data, I find common patterns of design and layout for a given typology. These patterns of affordance can then be used with a generative algorithm to generate a schematic design. In this thesis, I will present a number of schematic designs and explore the range of outcomes, limitations, and areas for improvement that you can expect from this approach to generative design. A final schematic design can then be matched with examples of vernacular objects and strategies found and documented through the pattern language of sacred space. Using data that I have collected about openings and furnishings in the case studies, it becomes possible to automatically populate these schematic designs with objects to complete the design. This thesis will detail this process and the theory behind it.

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