Now showing items 21-40 of 3333

    • Intimate Deathscapes: Examining Alternative Discourses of the Dead Body and Death Care Spaces

      Giesbrecht, Jennica; Department of Geography
      Over the last two centuries Western death care has undergone a gradual process of defeminization, professionalization, and medicalization. It has also grown into a multi-billion-dollar industry and is now facing criticism for practices that are financially exploitive, environmentally harmful, and contribute to the invisibilization of death. Over the last decade, alternative understandings of death and death care practices have begun to emerge in response to these criticisms. Some of these alternative understandings come from death care workers who espouse the benefits of engaging with death. In this thesis I examine the spaces of the dead body and death care spaces, which I refer to as intimate deathscapes. To consider the formation of subjectivities and knowledge production within intimate deathscapes, this thesis examines three autobiographies from death care workers (Doughty, 2014; Nadle, 2006; Wilde, 2017). The authors make compelling claims about the positive influence that can come from more engagement with death, which differ significantly from dominant discourses that pathologize death and cloak it in negativity and fear. Alternatively, they propose embracing mortality as a way of improving one’s life. I conclude that their material engagement with dead bodies, as represented in these texts, effects an epistemic shift in relation to death. Employing a material feminist framework, I argue that the spatiality and materiality of deathscapes influences the formation of subjectivities, and it is the relational and emergent subjectivities of the living and agencies of the dead that together produce an alternative knowledge about death, and consequently life. This knowledge contests the pathologization of the dead body and instead considers the potentially beneficial effects of more engagement with death. Therefore, in arguing that deathscapes are spaces from which these alternative death epistemologies can emerge, I echo challenges to dominant death care practices and support emerging discourses that propose more robust communication about death and call for changes to death care as a means toward more meaningful engagement in intimate deathscapes.
    • Distributed MAP-Elites and its Application in Evolutionary Design

      Hon, Derek; Department of Computer Science
      Quality-Diversity search is the process of finding diverse solutions within the search space which do not sacrifice performance. MAP-Elites is a quality-diversity algorithm which measures n phenotypes/behaviours of a solution and places it into an $n$-dimensional hypercube based off its phenotype values. This thesis proposes an approach to addressing MAP-Elites' problem of exponential growth of hypercubes. The exponential growth of evaluation and computational time as the phenotypes/behaviours grow is potentially worse for optimization performance. The exponential growth in individuals results in the user being given too many candidate solutions at the end of processing. Therefore, MAP-Elites highlights diversity, but with the exponential growth, the said diversity is arguably impractical. This research proposes an enhancement to MAP-Elites with Distributed island-model evolution. This will introduce a linear growth in population as well as a reasonable number of candidate solutions to consider. Each island consists of a two dimensional MAP which allows for a realistic analysis and visualization of these individuals. Since the system increases on a linear scale, and MAP-Elites on an exponential scale, high-dimensional problems will show an even greater decrease in total candidate solution counts, which aids in the realistic analysis of a run. This system will then be tested on procedural texture generation with multiple computer vision fitness functions. This Distributed MAP-Elites algorithm was tested against vanilla GP, island-model evolution, and traditional MAP-Elites on multiple fitness functions and target images. The proposed algorithm was found, at the very minimum, to be competitive in fitness to the other algorithms and in some cases outperformed them. On top of this performance, when visually observing the best solutions, the algorithm was found to have been able to produce visually interesting textures.
    • Improving Deep Exploration with Cost-Effective Geophysical Methods

      Furlan, Alexander; Department of Earth Sciences
      Subsurface exploration is rapidly changing and ‘easy to target’ deposits are depleting across the world. This reality has pushed exploration in two directions: re-evaluating known deposits and exploring greater depths. The goal of this thesis was to address these trends in a cost-effective manner. First, by combining geophysical, borehole, and open-source spatial data, a 3D model was synthesized for a volcanogenic massive sulphide (VMS) deposit located in Nash Creek, NB. Evaluating this model showed a need for structural controls to better understand the genesis of the deposit. A lesser-known geophysical system, Extremely Low Frequency EM (ELF-EM), measures ~2km deep and can produce conductivity models. While perfect for Nash Creek, ELF lacked modern software support which limited the modelling that could be done. Using an open-source inversion package, a python script is presented with this thesis that runs inversions of tipper (ELF) data to produce 3D conductivity models. This new workflow was tested at the Key Anacon VMS deposit near Bathurst, NB. A 3D wireframe model derived from geophysical surveying and borehole logs was available to compare with the ELF-EM derived model at Key Anacon. While individual mineralized horizons could not be discerned, a ‘conductive envelope’ follows a very similar strike and dip to the wireframe model. Promising results from Key Anacon led to the re-interpretation of past ELF-EM surveys. The final section of this thesis revisits a survey in Burwash Landing, Yukon to compare conductivity modelling results. The Burwash Landing survey aimed to identify potential geothermal wells drilling sites along the Denali fault. The new 3D model showed a coherent fault trace along strike, as well as eliminated several anomalies the researchers in the original paper could not explain. This improved ELF-EM inversion workflow has greatly improved 3D modelling of deep conductivity contrasts. In future, the techniques outlined here can be applied to various exploration scenarios while following the current trends in exploration.
    • Protein-Ligand Binding Affinity Directed Multi-Objective Drug Design Based on Fragment Representation Methods

      Mukaidaisi, Muhetaer; Department of Computer Science
      Drug discovery is a challenging process with a vast molecular space to be explored and numerous pharmacological properties to be appropriately considered. Among various drug design protocols, fragment-based drug design is an effective way of constraining the search space and better utilizing biologically active compounds. Motivated by fragment-based drug search for a given protein target and the emergence of artificial intelligence (AI) approaches in this field, this work advances the field of in silico drug design by (1) integrating a graph fragmentation-based deep generative model with a deep evolutionary learning process for large-scale multi-objective molecular optimization, and (2) applying protein-ligand binding affinity scores together with other desired physicochemical properties as objectives. Our experiments show that the proposed method can generate novel molecules with improved property values and binding affinities.
    • An exploratory study evaluating the effectiveness of a data driven approach to identifying coordinative features that are associated with sprint velocity

      vellucci, Christopher; Applied Health Sciences Program
      Sprint performance is multifactorial in nature and is dependent on a variety of coordination and motor control features. During the sequential phases of a sprint, the athlete completes a series of spatiotemporal coordination strategies to achieve the fastest possible velocity. The overall aim of the study was to leverage wearable sensor technology and data- driven tools to objectively assess the kinematic and neuromuscular determinants of optimal sprint velocity from a large dataset of university-aged sprinters. To achieve this, we recruited participants to run three 60 m sprints as fast as possible, while being outfitted with wireless electromyography (EMG) and a full-body inertial measurement unit (IMU) suit to obtain full- body 3D kinematics. Five strides about peak sprint velocity were selected and used for inputs into a principal components analysis (PCA). Significant stepwise multivariable regression models were generated for both kinematic and EMG features identified using PCA, with the kinematic model outperforming the EMG model as the kinematic model displayed a higher R2 value. This suggests that the kinematic dataset used in this study is a better predictor of sprint performance when compared to the EMG dataset, and that both may be viable options in the development of data-driven objective sprint coaching tools.
    • A Study of Retirement Transition and Fandom of Retired Hockey Players

      Pappas, Adam; Applied Health Sciences Program
      The purpose of this study was to understand and explore the retirement transition of professional men’s hockey players. Specifically, the research examined the role athlete identity theory has this important period of their lives (Brewer et al., 1993). Previous research has heavily ignored studying former professional players and the sport of hockey, but while some similarities exist in the athletic transitions for all sports, the experiences of retired professional hockey players are not necessarily representative of all other sports (Andrijiw, 2010). The study showed the importance of preparing for retirement and how not doing such can lead to many difficulties (Knights et al., 2019). To fulfill this study’s purpose, a qualitative research design was constructed to study retired men’s professional hockey players. Participants (n=11) who had been retired for a for a minimum of three years were sampled. Data were collected through semi-structured interviews, taking place either over the telephone or via virtual videoconferencing (Zoom), and then analyzed using a constructivist grounded theory approach (Charmaz, 2000). Four main categories arose, and within them, multiple sub-categories. These findings highlight the difficulties that can occur during the transitional years for a recently retired athlete, and how the athletic identity plays an important role in the process. This study provides a deeper theoretical understanding of the role the athletic identity has in the experiences retired hockey players have in their transition out of professional sport. The findings of this study could lead to continued awareness of these challenges so other athletes are aware of what might be in store for them in their retirements. Further research is necessary to continue to examine the uniqueness hockey retirement, as the challenges are far greater than many athletes realize.
    • Lithium and creatine supplementation, alone and in combination, for the promotion of adipose thermogenesis

      Finch, Michael; Applied Health Sciences Program
      Neutraceutical approaches to enhancing energy expenditure (EE) and adipose browning may provide a method of preventing obesity development. GSK3 has been identified as a negative regulator of UCP1. We have previously observed lithium, an inhibitor of GSK3, to increase UCP1 content and cellular respiration in 3T3-L1 adipocytes (0.5mM) and mice treated with 10mg/kg/day have increased EE, UCP1 and white adipose (WAT) multilocular phenotype. Creatine metabolism is also emerging as a critical regulator of adipose metabolism, and we have previously observed increased mitochondrial markers with creatine monohydrate supplementation. This study aimed to investigate the impact of supplemental lithium, creatine and their combination on EE and adipose tissue form and function. Male and female Sprague-Dawley rats were divided into four experimental groups for 6 weeks: (1) control, (2) lithium-supplemented (200 mg/L), (3) creatine-supplemented (5 g/L), (4) dual-supplemented (n=8 per group). All interventions increased EE and reduced body mass in males. In males, brown adipose (BAT) UCP1 was unaltered with lithium, however several mitochondrial and lipolytic markers were increased as well as inhibitory GSK3 serine9 phosphorylation. Creatine increased BAT UCP1 but had no effect on WAT thermogenic markers and lowered WAT mitochondrial and lipolytic markers. In females, none of the observed effects on EE, body weight and thermogenic proteins observed in males carried through to females. In female WAT, the treatments resulted in lower protein content of select mitochondrial and lipolytic proteins. Lithium supplementation was found to increase markers of BAT thermogenesis which likely contributes to the increased EE and reduced body mass in males. Creatine supplementation had a similar effect on EE and increased UCP1 protein content in the BAT of males. There was however no additive effect of the treatments, and all the results were independent of any evidence for a WAT browning/beinging effect suggesting that BAT is the main target of the treatments. None of the above observed effects of the treatments were translated to the females and could be, at least in part, due to sex differences in the adipose response to the treatments as GSK3 was differentially affected by lithium across sexes and depots.
    • The time(s) of our lives: Exploring and opening up alternative temporalities through the experience of disability

      McCowell, Kelly; Department of Child and Youth Studies
      The purpose of this qualitative study was to understand how some relate to time atypically and how, precisely through that relation, they help to disclose possibilities for alternative ways of being more generally. Both the COVID-19 pandemic as well as increasing threats of climate change have engendered an appreciation of the precariousness of our existence; in short, these crises have illuminated the inevitability of an uncertain future both immediately and in the long term. Despite the loom, the ways in which we live our lives in the dominant culture of Western society reflects a linear, future oriented temporality where able-bodied citizens often strive for progress and advancement, transformation, and ultimately mastery of the environment. Other temporalities exist, however, such as those shared by people whose bodily experiences construct their social realities in unconventional ways. Often it is their diagnosis that puts them out of line both with developmental time and fundamentally the neoliberal ethos of a productive life. This study strove to disrupt the domination of linear time and opposingly argued that these alternative relationships with time may be more well suited to the precarious nature of our lives. Guided by Rosemarie Garland-Thomson’s (2012) bioethical assertion that we might want to conserve rather than eliminate disability, I sought to uncover alternative temporalities in the hopes of disclosing their generative potential. Four memoirs written by parents of children with diverse disabilities were used as qualitative data to convey the experience of disability, temporalities and alternative ways of being in the world. The findings highlight opportunities for rethinking the ways in which we perceive and interact with time.
    • Relational Approach to the L-Fuzzy Concept Analysis

      Izadpanahi, Anahita; Department of Computer Science
      Modern industrial production systems benefit from the classification and processing of objects and their attributes. In general, the object classification procedure can coincide with vagueness. Vagueness is a common problem in object analysis that exists at various stages of classification, including ambiguity in input data, overlapping boundaries between classes or regions, and uncertainty in defining or extracting the properties and relationships of objects. To manage the ambiguity mentioned in the classification of objects, using a framework for L-fuzzy relations, and displaying such uncertainties by it can be a solution. Obtaining the least unreliable and uncertain output associated with the original data is the main concern of this thesis. Therefore, my general approach to this research can be categorized as follows: We developed an L-Fuzzy Concept Analysis as a generalization of a regular Concept Analysis. We start our work by providing the input data. Data is stored in a table (database). The next step is the creation of the contexts and concepts from the given original data using some structures. In the next stage, rules, or patterns (Attribute Implications) from the data will be generated. This includes all rules and a minimal base of rules. All of them are using L-fuzziness due to uncertainty. This requires L-fuzzy relations that will be implemented as L -valued matrices. In the end, everything is nicely packed in a convenient application and implemented in Java programming language. Generally, our approach is done in an algebraic framework that covers both regular and L -Fuzzy FCA, simultaneously. The tables we started with are already L-valued (not crisp) in our implementation. In other words, we work with the L-Fuzzy data directly. This is the idea here. We start with vague data. In simple terms, the data is shown using L -valued tables (vague data) trying to relate objects with their attributes at the start of the implementation. Generating attribute implications from many-valued contexts by a relational theory is the purpose of this thesis, i.e, a range of degrees is used to indicate the relationship between objects and their properties. The smallest degree corresponds to the classical no and the greatest degree corresponds to the classical yes in the table.
    • The Transition from Elementary to Secondary School: Lived Experiences of Grade 9 Students

      Marotta, Kendra; Department of Graduate and Undergraduate Studies in Education
      Emerging adolescence (12 to 15 years old) is a critical life period, as individuals experience many different changes in their social lives, which consequently impact their emotional self. Simply put, adolescent students experience many life transitions that can influence their emotional well-being. The purpose of this study was to explore adolescents’ perceptions of and lived experiences with their transition from elementary to secondary school. The research question that guided this study was: what are adolescents' perceptions about their experience of the transition from elementary (Grade 8) to secondary school (Grade 9)? This qualitative study collected data from three Grade 9 male students who were recruited from a private secondary school in Southern Ontario. As part of a survey, nine open-ended questions were answered by study participants in a virtual format. A thematic analysis revealed two main topics across participants’ experiences: social support and coping with stress. Findings revealed that adolescent males experienced academic, emotional, and social challenges in their transition from elementary and secondary school, and that emotional well-being plays an important role for this demographic during this transition. Overall, this study provides a novel and unique insight into adolescent males’ lived experiences during and their emotional well- being through the transition to secondary school. Future research and mental health programs should consider the importance of male adolescent perspectives during this educational transition and other schooling experiences.
    • A surface plasmon resonance investigation of the role of bilayer phospholipids in the binding and ligand interactions of the ⍺-tocopherol transfer protein.

      Mehta, Vansh Ankitbhai; Centre for Biotechnology
      Vitamins are, by definition, required for maintaining the health of the mammalian body. Vitamin E, which occurs in eight different forms, has a crucial function as an antioxidant protecting polyunsaturated fatty acids. Attributable to the occurrence of alpha-tocopherol transfer protein (a-TTP), RRR-a-tocopherol is the only form that is selectively retained in mammals. a-TTP aids in secreting the RRR-a-tocopherol from liver to the rest of the body. The mechanism of the a-TTP-mediated movement of a-tocopherol is not yet fully elucidated. The opening of a-TTP's binding pocket and subsequent release of a-tocopherol are made possible by a-TTP's interaction with PM residing phosphatidylinositols. K217, a crucial amino acid, is present in the positive surface patch of a-TTP, which is essential for orchestrating this interaction. Surface Plasmon Resonance (SPR) was employed in this study to examine the absorption and desorption of wild-type a-TTP and the mutated form K217A to tethered phospholipid vesicles. SPR spectroscopy illustrated the affinity of either protein when it was presented with one or both of its preferred ligands (a-tocopherol or phosphatidylinositol-4,5-bisphosphate [PI(4,5)P2]) on tethered vesicles. Bovine serum albumin (BSA) was used to coat the side of the microcentrifuge tubes to mitigate protein loss that was discovered when protein was preincubated with its ligands. K217 was found to be instrumental in the binding of TTP to PIPs and the subsequent release of tocopherol. As K217A mutant had a lower adsorption to membranes containing PI(4,5)P2 vs wtTTP. It was determined that α-TTP binding to endosomal vesicles increased with increased concentration of the late endosome specific lipid bis(monoacylglycero)phosphate (BMP). Collections runs performed provided some evidence for the exchange of ligands when wtTTP was used but not for K217A. The results found in this work parallel literature findings and supplement the proposed mechanism of a α-TTP-mediated movement of α-tocopherol and PI(4,5)P2 in plasma membranes.
    • The Effect Of Vibratory Noise Input On Postural Responses To An Unexpected Loss Of Balance

      Amiaka, Chimerem; Applied Health Sciences Program
      Vibratory noise input applied to the foot sole has been shown to improve static balance control across various populations (i.e., younger adults, older adults, individuals with diabetic neuropathy etc.). However, there is little research on whether vibratory noise improves reactive balance control. This is concerning because falls typically occur when an individual is unable to quickly recover from a loss to their balance. Therefore, the purpose of this thesis was to examine whether vibratory noise input affects postural responses following an unexpected surface translation. A secondary aim was to examine the effects of vibration on static balance performance to replicate previous findings. Eighteen adults (10 females and 8 males) completed six quiet standing trials and 28 surface translation trials. For all trials, participants stood barefoot, while blindfolded and wearing headphones. Three vibrating elements were placed directly underneath each foot (i.e., one each at the first metatarsal, fifth metatarsal and at the heel). For each standing trial, participants were instructed to stand quietly. For each surface translation trial, participants were instructed to recover their balance without stepping in response to a unexpected surface translation. Participants were unaware of which trials did or did not have vibration applied to the foot soles. Static and reactive balance control were quantified using various kinematic, kinetic and electromyography (EMG) measures, while the ability to recover balance was quantified through the measurement of EMG and body kinematics. Results indicated that vibratory noise input did not influence most measures of static and reactive balance control. This suggests that the application of vibratory noise input to the foot soles is not beneficial in younger adults. Future studies should replicate this study with clinical populations to determine whether the benefits of vibratory noise input are limited to individuals with worsened balance ability.
    • The Feasibility of Wearable Sensors for the Automation of Distal Upper Extremity Ergonomic Assessment Tools

      Cousins, Daniel; Applied Health Sciences Program
      Work-related distal upper limb musculoskeletal disorders are costly conditions that many companies and researchers spend significant resources on preventing. Ergonomic assessments evaluate the risk of developing a work-related musculoskeletal disorder (WMSD) by quantifying variables such as the force, repetition, and posture (among others) that the task requires. Accurate and objective measurements of force and posture are challenging due to equipment and location constraints. Wearable sensors like the Delsys Trigno Quattro combine inertial measurement units (IMUs) and surface electromyography to solve collection difficulties. The purpose of this work was to evaluate the joint angle estimation of IMUs and the relationship between sEMG and overall task intensity throughout a controlled wrist motion. Using a 3 degrees-of-freedom wrist manipulandum, the feasibility of a small, lightweight wearable was evaluated to collect accurate wrist flexion and extension angles and to use sEMG to quantify task intensity. The task was a repeated 95º arc in flexion/ extension with six combinations of wrist torques and grip requirements. The mean wrist angle difference (throughout the range of motion) between the WristBot and the IMU of 1.70° was not significant (p= 0.057); but significant differences existed throughout the range of motion. The largest difference between the IMU and the WristBot was 10.7° at 40° extension; this discrepancy is smaller than typical visual inspection joint angle estimate errors by ergonomists of 15.6°. All sEMG metrics (flexor muscle root mean square (RMS), extensor muscle RMS, mean RMS, integrated sEMG (iEMG), physiological cross-sectional area weighted RMS) and ratings of perceived exertion (RPE) had significant regression results with the task intensity. Variance in RPE was better explained by task intensity than the best sEMG metric (iEMG) with R2 values of 0.35 and 0.21, respectively. Wearable sensors can be used in occupational settings to increase the accuracy of postural assessments; additional research is required on relationships between sEMG and task intensity to be used effectively in ergonomics. There is potential for sEMG to be a powerful tool; however, the dynamic nature and combined exertion (grip and flexion/ extension) make it difficult to quantify task intensity
    • Using Persistent Homology for Topological Analysis of Protein Interaction Network of Candida Antarctica Lipase B Molecular Dynamic Simulation Model

      Tajik, Samin; Department of Physics
      In this work, we aim to examine the activity of one of the most efficient and commonly used lipases, Candida Antarctica Lipase B (CalB), from the perspective of multiple computational techniques. To this end, we first conduct a series of Molecular Dynam- ics Simulations on CalB in different conditions to analyze the conformational changes of the protein and probe its unusual high-temperature activity. Next, we build the protein interaction network of amino acids for CalB to study pairwise interactions between amino acids (nodes) and probe the protein in terms of statistical features of links’ distribution. Finally, we employ an algebraic topology-based method to study the protein interaction network from a broader perspective. The ”Persistent Homol- ogy (PH) method” is then presented as a way to exceed pairwise interactions and examine protein networks in terms of patterns of interaction between the nodes. Per- sistent Homology studies the evolution of the protein interaction network’s topologi- cal features (homology groups) in different states. Employing topological analysis, we compare the active form of CalB at high temperatures to its inactive states to account for possible topological contributions to the protein functionality. By discovering a prominent 1-dimensional hole in the active form of the protein, we highlight the role of higher-order interaction patterns in the network. Moreover, using the evolution of topological features, we study topological changes in protein networks and show the decline in the total number of 1-dimensional features as the protein loses activity and compactness over time. Accordingly, we propose that the protein’s general conforma- tional changes and three-dimensional structure are not the only facets contributing to its active state. Instead, we suggest examining the topology of the protein inter- action network, referred to as different dimensional holes of the networks, as a higher dimensional analysis should be used to account for protein functionality. Hence, in this work, we desire to present that one needs to consider topological features acting as patterns of interaction between the components to study, examine or predict the folding of polypeptide chains into active structures.
    • Gen Z and Sustainable Diets: A Holistic Perspective. Understanding Perceptions of and Engagement with the Social, Economic and Environmental Dimensions of a Sustainable Diet

      Ruzgys, Shannon; Environmental Sustainability Research Centre
      Current food production methods are causing wide scale degradation of the natural environment thus a shift towards more sustainable agricultural systems is essential in fighting the climate crisis. Understanding how Gen Z, a generation that will inherit the changing climate, relates to the social, economic and environmental aspects of a sustainable diet is important in ensuring they are aware how to make an impact with their dietary choices. This thesis aimed to gain a holistic understanding of Gen Z's perceptions of and engagement with sustainable diets. Two studies were conducted online, examining Canadian youth between the ages of 18-25. The first study took an exploratory approach, aiming to understand what a sustainable diet means to Gen Z in their own words. The second study took a predictive approach, aiming to quantify and understand Gen Z's action stages around a range of sustainable dietary behaviours, including the psychological and educational factors that influence their stage of change. Results from Study One highlighted that youth perceive behaviours centered around supporting their local community and reducing food waste to be effective for promoting a sustainable diet. In addition, over 60% of participants indicated that there were barriers preventing them from engaging in sustainable diets, such as cost. Results from Study Two revealed that a high food literacy score and a strong belief in the efficacy of a behaviour are the two most important predictors of being in an action stage for a range of sustainable dietary behaviours. Together these two studies provide a holistic overview of what sustainable diets mean to Gen Z, how they currently engage with sustainable diets, and ways to encourage action. The thesis also contributes to the scholarly literature on the use of TTM and TPB in assessing the factors that influence engagement with sustainable dietary behaviours. It also offers practical recommendations on how our results can be used to shape policy, educational interventions and marketing towards Gen Z.
    • Urban forest management planning: A case study of municipalities in Southern Ontario

      Thomson, Tyler; Environmental Sustainability Research Centre
      This current study reviews urban forest management planning in Ontario through a sustainability lens. After clarifying key terms and concepts in the field of urban forestry, the paper moves towards an analysis of two urban forest management plans from municipalities in Ontario. This analysis was accomplished using a qualitative content analysis approach, where the content from two urban forest management plans was assessed against a framework that defines core principles of sustainable urban forest management. Key insights from this analysis are then identified and used to present a framework the Town of Lincoln can follow to develop an UFMP for their urban forest. The findings from this study found that municipalities have a strong desire to achieve sustainable urban forest management, but external challenges and internal limitations present barriers to achieve this.
    • Effects of Red Rooibos on Mandibular Bone Structure in Sprague-Dawley Rats at 4 Months Post-Lactation

      Condino, Darrah; Applied Health Sciences Program
      Physiological changes during pregnancy and lactation result in challenges to the maternal rodent skeleton. Red rooibos (RR) supplementation to rats was previously shown to support the recovery of tibia bone structure through to 4 months post-lactation. Given the associations between oral and systemic health, this research used multiple ROIs within the mandible to determine: if there are differences in trabecular bone structure at 4 months post-lactation compared to the non-pregnant control; the effects of a RR intervention administered from pre-pregnancy through 4 months post-lactation on trabecular bone structure compared to no RR intervention; and if measured outcomes are similar among groups regardless of the ROI studied. 6-week-old female Sprague-Dawley rats (n=42) were randomized to PREG TEA (pregnancy and lactation; supplemental level of RR in water ~2600 mg/kg body weight/day), PREG WAT (pregnancy and lactation; water), or GROWTH CON (non-pregnant control; water), bred at 8-weeks of age and maintained until 4 months post-lactation when mandibles were excised. Micro-computed tomography was used to measure bone structure at four ROIs: fixed shape or manually drawn ROI in molar 1 (M1) or molar 2 (M2) site. At M1, analyses using a fixed ROI demonstrated that PREG TEA had a higher bone volume fraction (p<0.05) and lower trabecular separation (p<0.05) compared to PREG WAT. This may be explained by the structural outcomes characterizing trabecular struts, in which degree of anisotropy was lower (p<0.05) in PREG WAT compared to GROWTH CON. Irrespective of whether the ROI was drawn manually or fixed, the PREG TEA group demonstrated a partial recovery as trabecular number, separation, and thickness were not significantly different from GROWTH CON (p>0.05), whereas PREG WAT had significantly lower (p<0.05) bone volume fraction and trabecular number than GROWTH CON. At M2, few significant outcomes were observed regardless of ROI. This may be due to the lower amount of bone present at this site. Pregnancy and lactation resulted in deficits to mandible bone, but RR supplementation supported partial recovery, which aligns with previous findings for tibia. Findings can inform future research about which mandible site to select to measure a response to a dietary intervention.
    • Examining Types and Performance of Urban Green Space: Case Studies of Toronto, Milan, and Isfahan

      Sattar, Tannaz; Environmental Sustainability Research Centre
      Cities have significant impacts on sustainability and sustainable development. In the context of global development, especially in developing large metropolitan areas, the urban population is growing resulting in social and environmental challenges that threaten the sustainability of cities. One of the challenges of this modern urbanization addresses urban green spaces (UGS) regarding their quantity and performance. UGS are essential parts of urban areas lack of which can compromise urban ecology and human well-being. Enhancing UGS is an approach to overcome some of these challenges. Little research has been done on the UGS typologies and different variables affecting their performance, and also the literature on comparing this feature in hugely different contexts is missing. This paper intents to compare UGS categories in the three selected cases, which are the cities of Toronto (Canada), Milan (Italy), and Isfahan (Iran), and analyze their performance variables.
    • Rethinking Consumerism, Innovation and Tourism Sustainability in a Post-Viral World: An Exploratory Study of PIRT Usage in Niagara's Geoparks

      Mensah, Abigail; Department of Geography
      Tourism resilience in the face of a prevailing pandemic and accompanying global uncertainties remains a concern to many stakeholders. A key area of interest for the industry regards the pandemic's potential to influence change in people's consumption patterns, possibly toward more sustainable, ethical, safe and technologically mediated forms of tourism. Such pandemic-induced attitudinal changes can, in turn, affect how tourism will be consumed in future. These changes may further translate into the need for new exchange relationships, tourism experiences, resources, and innovations to aid interactions between service providers (tour guides), tourists and destinations. With the advent of technology-driven solutions for normalization during the pandemic, some studies have predicted shifts from traditional long-haul travels to virtual tourism as they are considered to be a safer, accessible, and ecologically friendly form of tourism. This exploratory research, therefore, sought to unearth the influence of Covid-19 on Millennial students' preferences for virtual tours in the aftermath of the pandemic. The objectives were to identify factors that can influence intentions for change in people's tourism preferences based on their experience of the pandemic, to explore tourist perceptions about the potential of virtual tour innovations like PIRTs to meet their future preferences, and to investigate how this connection can translate into prospective models in Niagara's geopark tourism sector. Quantitative data was collected from 117 sampled students in the Brock University community through an online questionnaire. The findings revealed that financial, experiential, and ecological concerns are significant factors which will possibly influence Millennials' travel patterns and their inclination to use PIRTS in the post-Covid era. Based on these findings, suggestions are made on how smart tourism innovations such as PIRTs can be harnessed as resilient alternatives to conventional tourism in Niagara Peninsula Aspiring Global Geopark (NPAGG) destinations to promote socio-ecological wellbeing in the region.
    • Synthesis of a Photocleavable Bolalipid for the study of the roles of Phospholipid Transfer Proteins and Phosphatidylinositol Lipid Kinases

      Wilson, Sean Daniel; Department of Chemistry
      This thesis was dedicated to the synthesis of mono- and di-photocleavable phosphatidylcholine bolalipids that were designed to investigate the mechanism of action of the phospholipid transfer protein, Sec14, as well as the phosphatidylinositol 4-kinase, Pik1. While it was the goal of this thesis to synthesize both bola-PCs, only the mono-photocleavable bola-PC was successfully synthesized. The mono-photocleavable bola-PC lipid was designed to contain two glycerol molecules that each had a choline head group connected through a phosphodiester bond at the sn3 position. Each glycerol was acylated with palmitic acid at the sn1 position. These two glycerol moieties were then connected to one another through their respective sn2 hydroxyls via a mono-photocleavable dicarboxylic acid. The initial steps of this work were to synthesize mono- and di-photocleavable diacids to serve as a linker for the polar head groups of the bolalipids. The mono- and di-photocleavable diacids were designed to contain one and two nitrophenyl ethyl photolabile protecting groups, respectively. The synthesis of the di-photocleavable diacid was attempted first, however, these efforts were unsuccessful. Two separate synthetic routes were followed to synthesize this diacid, but neither were viable. Despite this, the synthesis of the mono-photocleavable diacid was successful and was incorporated into a bola-PC. The mono-photocleavable diacid and bola-PC were found to undergo photocleavage when irradiated with 365 nm light, in 60 seconds and 105 seconds, respectively. Photocleavage of the bola-PC was also carried out within a lipid vesicle comprised of 10% bola-PC and 90% DOPC. Spectral and experimental data have been provided for all compounds synthesized. Future efforts will involve the bola-PC synthesized in this thesis undergoing enzymatic conversion into a bola-PI, via the enzyme phospholipase D.