title: Identifying Opinion Based Questions in Developer Chat Communication

abstract: Today, software developers work on complex and fast-moving projects that often require instant assistance. With numerous topics discussed in parallel in chat servers such as Discord, mining them would offer researchers opportunities to develop software tools and services. Firstly, we propose a dataset called DISCO consisting of the one-year public DIScord chat COnversations of four software development communities. Secondly, we improve the existing ChatEO's opinion-asking question identification process by replacing heuristics with Deep Learning (DL) architecture (with various word embeddings) in Natural Language Processing tasks. The results show a better performance of DL models over heuristics and are validated with a manual qualitative study. We have employed an automatic weak learner, Snorkel to label a larger dataset to increase DL performance. We have also used class balancing techniques - SMOTE and Near-Miss on this larger dataset. SMOTE along with Multi-CNN and GloVe-Twitter achieves the best performance in this study (0.95 recall).


title: Pluriversality and Care: Rethinking Global Ethics

abstract: A perennial debate in the field of Global Ethics revolves around the possibility of a universalist ethics, and contestations over the nature - and significance - of difference (be it economic, cultural, political, etc.) for moral deliberation. Alongside, but heretofore not explored in depth by, the Global Ethics literature is a growing literature (coming from decolonial studies and the 'ontological turn' in anthropology) on multiple ways of being-in and seeing the world, described by the language of the 'pluriverse' (de la Cadena 2015; Mignolo 2013). This scholarship illuminates not only the  different ontologies or worlds that exist globally, but also the political processes through which these worlds come into contact, conflict, and in many ways, co-constitute each other. In this way, while the pluriversal scholarship points to ontological difference, it also emphasizes the (partial) connections (Strathern 2004) between worlds. This dissertation begins with the concept of the pluriverse - the idea that instead of a single world with different paradigms, we have a matrix of multiple yet connected worlds - and investigates the ways in which this notion necessitates a rethinking  of the field of Global Ethics as it has been conceived thus far. In particular, I consider how the field can reorient itself towards building an ethics for the pluriverse, where differences are deep and pervasive, i.e., ontological. Ultimately, drawing upon a feminist ethics of care, I argue that a pluriversal ethics can fruitfully be thought of as an ethics of vulnerability and precarity. The ethics of care is premised on a relational social ontology, which sees ethics as a problem of responsibilities in relations, and which foregrounds the moral saliency of our mutual vulnerability  (including the vulnerability of moral judgement) that stems from our relationality. In so doing, the ethics of care reconceptualizes moral dilemmas along relational lines. My argument is that this line of thinking, when combined with a conceptual distinction between vulnerability and precarity (where precarity refers to intensified vulnerability that results from unequal relations of power), provides a useful meta-theoretical orientation from which to begin building a pluriversal ethics.


title: On the Fringe - Analysis of Violent Discourse on Ideologically Motivated Violent Extremism on Less Regulated Social Media Platforms

abstract: Smaller, less-regulated social media platforms are increasingly exploited and misused for sharing and communicating harmful and violent ideological grievances. In some instances, these platforms are used to facilitate and express support for real-world acts of violence inspired by ideologically motivated violent extremist (IMVE) grievances. The following paper aims to better understand the role of smaller, less-regulated platforms in facilitating a hospitable environment for IMVE narratives, messaging, and activity. The research is guided by two questions: (1) How does the trajectory of  violent discourse manifest on smaller, less-regulated social media platforms? (2) What is the level of user engagement (i.e., comments) with violent content inspired by ideologically motivated violent extremism? Using four original datasets built using data from 4chan's /pol/ board, the paper provides analysis that better situates our understanding of the impact of online violent discourse in inciting and inspiring acts of real-world violence.


title: FLightNER: A Federated Learning Approach to Lightweight Named-Entity Recognition

abstract: We introduce FLightNER, a Federated Learning model that extends a state-of-the-art Named-Entity Recognition model using prompt-tuning known as LightNER. FLightNER allows the aggregation of only the trainable parameters of LightNER without model accuracy degradation saving 10 GB per client and enabling more clients to join a federation without extending the central server's memory. We evaluate our approach against two baselines using three diverse datasets with different distributions across up to seven clients in a federation. We empirically show that compared to the centrally-trained LightNER model, FLightNER outperforms it by 19% when performed on an unbalanced medical dataset and matches it when performed on two balanced datasets: CoNLL and I2B2. Furthermore, we use and evaluate two memory-saving techniques: AdaFactor optimizer and Automatic Mixed Precision. Our findings enable owners of sensitive data, such as healthcare practitioners, to train a NER model collaboratively, with low memory requirements, while keeping their data on-premise.


title: An Efficient Quantum Message Authentication Scheme

abstract: Quantum networking is the study of transmitting data that uses quantum mechanics principles (quantum messages). This thesis describes an algorithm that detects when an adversary maliciously modifies a quantum message (an integrity attack). The algorithm is analyzed in terms of its ability to detect an integrity attack and its efficiency in terms of classical computational complexity and the number of quantum basic gates used. It is rigorously compared to the Clifford code quantum message authentication (QMA) scheme. It offers a trade-off compared to the Clifford code QMA scheme in terms of integrity attack detection versus efficiency: reduced detection rates and improved efficiency. The new algorithm is conjectured to satisfy a more lax alternative definition of QMA. As a consequence of developing this new algorithm, a novel method for unranking permutations of multisets is also presented.


title: Role of Glucose-induced Transcription Factor Signalling and Mitochondrial Epigenetics in Stress Tolerant Wood Frog, Rana sylvatica

abstract: The freeze-tolerant wood frogs, Rana sylvatica are one of only a few vertebrate species in the animal kingdom, which are extensively studied to understand vertebrate freeze tolerance. They undergo whole-body freezing during winter and become ice solid with no heartbeat, brain activity and blood flow but amazingly come back to life during spring unharmed without any major changes in their body. Freeze survival is challenging, with wood frogs facing ischemia due to freezing of blood, dehydration via cell volume reductions due to loss of 60-70% of total body water into extracellular space as well as hyperglycemia, producing a huge amount of glucose as a cryoprotectant. Interestingly, wood frogs can also tolerate these stresses independent of freezing. Also, winter survival by wood frogs is associated with a metabolic reorganization to reduce their energy demands to a bare minimum by globally suppressing energy-expensive pathways and selectively regulating genes to prioritize available energy use for pro-survival pathways. This thesis examined the effects of freezing and dehydration-induced hyperglycemic response in selectively inducing transcription factor MondoA in regulating glucose-induced transcription and activating an adaptive transcriptional response to induce stress response via inflammasome activation, mitochondrial dysfunction and mitochondrial epigenetics. The current findings establish MondoA in guiding an adaptive transcriptional response to activate genes regulating glucose homeostasis and circadian rhythm in a tissue-specific manner in the liver during the freeze/thaw cycle. Also, the role of TXNIP (downstream to MondoA) and its PTMs, in activating inflammasome via NLRP-3 in stress-specific way during freezing was shown. Moreover, the higher mitochondrial presence of TXNIP did not correlate to protein expression of its downstream targets in inducing mitochondrial dysfunction in any of the stresses, which were attributed to its low/weak binding to TRX-2. Investigating the role of mitochondrial methylation suggests its tissue-specific regulation in the liver and potential role in maintaining a tight regulation of mitochondrial transcriptional and gene expression response. Altogether, findings from this thesis demonstrate that a highly synchronized and intricate control via multiple levels of regulation is present in activating mechanisms that are involved in maintaining cellular milieu during stress in wood frogs.


title: Image Processing Techniques for Analysis of Myocardial Fibrosis and Related Cardiomyopathies in Cardiac Magnetic Resonance Imaging

abstract: Myocardial fibrosis (MF) is a common feature of cardiac disease, characterized by excessive deposition of collagen (i.e., scar tissue) and expansion of the myocardial extracellular volume (ECV). This phenomenon contributes to cardiac dysfunction, promotes further cardiac disease, and has implication in preceding cardiac morbidity and mortality. The extent of myocardial MF can be analyzed globally (across the entire myocardial region) and/or regionally (across the fibrotic area exclusively) using cardiac magnetic resonance (CMR) imaging techniques, such as late gadolinium enhanced imaging or quantitative methods like native T1 and ECV mapping. CMR-based measurements of MF, native T1, and ECV allow for differentiation between various cardiac disease states and are shown to be clinically significant predictors of patient outcomes. However, in order to analyze tissue volumes or classify disease states, clinicians must first perform a manual tracing of the myocardial borders to define an initial region of interest (ROI), while regional MF quantification requires additional manual selection of a reference healthy myocardial tissue region. These manual processes are tedious, user-dependent, and highly prone to operator error, which can significantly confound resultant measures of T1, ECV and quantified MF tissue zones. Thus, alternative, minimally user-dependent techniques for MF, T1 and ECV quantification are appropriate. In this dissertation, several techniques for improving automated quantification of myocardial T1, ECV, and MF regions are presented. The proposed approaches presented in this document incorporate concepts from deep learning and image processing to achieve automated or semi-automated segmentation of the myocardium, MF, T1 and/or ECV in the left ventricle (LV) and left atrium (LA).


title: Enhanced Indoor Visual Navigation using Sensor Fusion and Semantic Information

abstract: Accurate and robust indoor navigation systems are crucial in fields like robotics and autonomous vehicles. In the absence of an absolute positioning system like GPS, there is no single sensor that can provide an accurate and robust indoor navigation solution. The presented thesis tackles the indoor navigation challenge using two approaches; multi-sensor fusion and semantic information. In the first approach, visual odometry is enhanced by the fusion of inertial sensors and wireless ranging measurements. The fusion filter is based on Extended Kalman Filter (EKF). Stereo vision can provide 3D positioning by triangulating visual features. However, depth estimation errors and expensive computation are key challenges. The developed multi-sensor system has dual-mode where stereo vision is applied first to estimate inertial sensor biases. Once converged, the estimated biases help the system to switch to a monocular mode which reduces the system complexity and enables the tracking of faster movements with higher frame rates. As both visual and inertial tracking are drifting solutions, wireless ranging/positioning is integrated into the system to provide absolute global positioning and ensure overall accuracy. In the second approach, an improved Visual Simultaneous Localization and Mapping (VSLAM) solution using semantic segmentation and layout estimation is developed. The system utilizes advanced semantic segmentation and indoor layout estimation to optimize map representation and increase positioning accuracy. A testbed has been developed to collect indoor multi-sensor data and to perform experiments and analysis. Out of this thesis work, three conference papers were published, one journal paper was published, in addition to one journal paper and one conference to be submitted.


title: Geographic Distribution of Trends and Cycles in Eastern North American Instrumental Climate Data

abstract: The potential environmental impact of a changing climate has been an increasingly prominent focal point of scientific and popular literature. Much of this literature has focused on global or continental trends, despite there being differences in long-term trends and medium-term variability on smaller geographic scales. This dissertation considers historical temperature and precipitation records in eastern North America, analyzing long-term changes and the influence of oscillatory climatic drivers.Three broad themes are addressed in this study, with a common methodological core. An assessment of extreme weather trends throughout the eastern North America study region is presented first. Next, two case studies are done to more thoroughly examine localized phenomena, specifically, an examination of historical climate variability in Ottawa, Ontario, Canada, and an examination of climatic drivers affecting lake ice phenology in southwest New Brunswick and adjacent eastern Maine. The methodological basis for this study is a combination of time-series analysis techniques, applied to time-dependent instrumental or proxy data. The results indicate that regional extreme weather time series, as well as local weather or weather-related time series, are best characterized in terms of long-term periodic trends due to known climatic drivers. The most significant of these drivers is the 11-year Schwabe Solar Cycle (SSC), which affects most if not all of the weather time series studied. Otherwise, cyclic patterns can be divided into interannual, interdecadal, and multidecadal scales. The most influential drivers of interannual climate patterns were the Quasi-Biennial Oscillation and the El Nino Southern Oscillation. At the interdecadal level, in addition to the SSC, the Pacific Decadal Oscillation was a common driver of extreme and non-extreme weather phenomena in the region. The combination of a larger-scale study with two case studies made it possible to discern spatial patterns in regional weather. For extreme weather, the region of interest can be subdivided into three climatically distinct subregions by applying hierarchical clustering to extreme weather counts. Subregional spatial coherence in eastern North America was further demonstrated by localized coherence between seasonal temperature records in eastern Ontario and southwestern Quebec, and similar localized coherence in ice phenology in southern New Brunswick and eastern Maine.


title: The Ten$ion of Post-Apartheid Whiteness: A Study of Die Antwoord's Performance of White Identity and Power

abstract: Die Antwoord are a South African rap group based in Cape Town that has achieved unparalleled success in the Western world. Whereas their Western fan base is vast, fervent, and embraces the group for their African Otherness, they are far less revered or even respected in their home nation. Die Antwoord's artistic production possesses a distinct postcolonial and postmodern mandate to tactically confront, through parody, what they view as the racial injustices of post-apartheid South Africa. Problematically, to reinscribe their whiteness, they unapologetically appropriate the unique cultural signs and symbols of other persecuted and unacknowledged South African races and cultures.


title: Amphiregulin and Growth Differentiation Factor 11 Promote Retinal Ganglion Cell Survival In Vivo through Activation of Smad3

abstract: Although adult neurons in the mammalian central nervous system do not spontaneously regenerate after injury, growing evidence indicates that genetically manipulating them can increase their ability to regenerate their axons. However, as genetic manipulation is not clinically feasible, current research continues to investigate pharmacological approaches to transiently enhance the intrinsic ability of adult CNS neurons to survive and regenerate their axons. Amphiregulin is a unique epidermal growth factor receptor ligand that has been shown to be crucial in liver regeneration, and accumulating evidence suggests that AREG signaling can promote both survival and axon regeneration of neurons. Growth differentiation factor 11 is a member of the transforming growth factor β superfamily, and it has been shown to exert rejuvenation effects in the aged brain and promote neuronal survival in the CNS. However, it is unknown whether AREG and GDF11 can induce neuronal survival and axon regeneration in the visual system. Hence, the current study investigated: 1) the developmental and post-injury expression pattern of these two ligands and their respective receptors, EGFR and activin-like kinase 5, 2) the potential neuroprotective and regenerative effects of these two ligands on retinal ganglion cells by using optic nerve crush model, and 3) the molecular mechanisms mediating the neuroprotective and regenerative effects of AREG and GDF11 on RGCs. Based on the western blot and immunohistochemical data, both AREG and GDF11 are consistently expressed throughout the retina development, but their receptors are only upregulated during the early retina development. Furthermore, AREG expression is significantly reduced in the adult retina 7 days after ONC whereas GDF11 expression remains unchanged after ONC. Interestingly, while EGFR expression is only upregulated 3 days after ONC, ALK5 expression is consistently upregulated throughout the post-injury time course. A single intravitreal injection of AREG or GDF11 immediately after ONC promoted significant RGC survival by activating Smad2/3 pathway. Because both ligands were not able to promote RGC axon regeneration, activation of Smad2/3 pathway may promote RGC survival but suppress RGC axon regeneration. Overall, the findings indicate that both AREG and GDF11 hold therapeutic potential for both neurodegenerative diseases and retinal degenerative diseases.


title: Well-Being During Times of Heightened Social Isolation: A Panel Study Examination of the Protective Effects of Social Support Availability

abstract: The COVID-19 lockdowns had negative impacts on psychological well-being and amplified certain stressors (e.g., social isolation), especially in at-risk populations. My thesis examined social support availability as a coping strategy. Single people living alone (N=220) were recruited during the initial 2020 lockdown and followed over a period of six weeks. Each week, participants reported their perceived social support availability, social isolation, and life satisfaction. I hypothesized that greater perceptions of social support availability, both on the within- and between-person levels, would buffer the negative effects of social isolation on psychological well-being. Multi-level modeling results showed that stress-buffering occurred on the between-person level. Associations were analyzed longitudinally, revealing that lagged social isolation did not predict life satisfaction the week after. An interaction was observed between lagged social isolation and lagged social support availability, such that lagged social isolation predicted less life satisfaction when social support was unavailable the week before.


title: Precision Measurements of Properties of W and Z Bosons with the ATLAS Experiment

abstract: The ATLAS Experiment measures the properties of particles created in the high-energy proton-proton collisions delivered by the Large Hadron Collider at CERN. The Standard Model of particle physics is our best description of the subatomic world - this well-studied theory provides accurate and precise descriptions of the fundamental particle properties and their interactions. Multiple areas of the Standard Model make predictions that are more precise than the corresponding experimental measurements - in some cases, increased experimental precision could suggest significant discrepancies between the Standard Model prediction and experimental measurement, potentially hinting at new physics to elucidate. One such area of tension between prediction and experiment is in the weak sector, whose force is mediated by W and Z bosons. The current best predictions based on the Standard Model do an inadequate job of precisely predicting one important observable of W and Z bosons: their transverse momentum, p_T. Precision measurements of properties like the p_T of W and Z bosons improve our knowledge of the weak sector, and are vital stepping stones to critical measurements like the mass of the W boson, whose most recent reported measurement is inconsistent with the Standard Model prediction. In this thesis, I explain my work using ATLAS data to make high-precision measurements of the p_T of W and Z bosons using the decay channels W --> l nu and Z --> l l (l = e, mu) at centre-of-mass energies 13 and 5 TeV using a special low-pileup dataset. I show that I have helped reduce the systematic uncertainties to percent-level precision and that statistical uncertainties are dominant, which demonstrates that more low-pileup data should be taken in order to further reduce the total uncertainty to eventually help resolve Standard Model weak-sector discrepancies like that of the W boson mass. I also detail my work to improve the way that electrons are identified by the ATLAS detector using a technique called W tag-and-probe. In particular, I validated the use of a new trigger designed specifically for electron identification with the W tag-and-probe technique.


title: Tensor Networks for Operator-Algebraic Constructions of Gauge Theories

abstract: Quantum field theory (QFT) is a conceptual framework for understanding the behaviour of subatomic particles—the most successful, mathematically rigorous formulation of QFT is in the language of operator algebras. In this thesis, we describe the construction of specific kinds of QFTs using operator-algebraic methods. Once we have described their construction in detail, we use tensor network methods (which are at the centre of modern quantum physics) to build approximations of these QFTs. We finish with a discussion on the relationship between our tensor networks and those used in toy models of the AdS/CFT correspondence.


title: Monte Carlo Modelling of an Orthovoltage X-ray System Using Multiple Applications in EGSnrc

abstract: Biodosimetry relies on calibration curves to convert biological damage induced by ionizing radiation to an absorbed dose. Health Canada generates these curves by irradiating biological samples with X-rays, though exposures scenarios could consist of other types of radiation which are challenging to replicate in the laboratory. The ultimate goal of this work is to model the X-ray setup using Monte Carlo methods and to validate the model using in-laboratory measurements. The model was iterated through preliminary and final testing phases in different EGSnrc applications (egs++, SpekPy and BEAMnrc) and optimized using variance reduction techniques, resulting in multiple models. The X-ray spectra produced from each model were compared and found to be equivalent. Model outputs were also compared against laboratory measurements to identify the most accurate model. The final model output will be used in the next phase of the project to model radiobiological damage.


title: Social cognition in young adults who have a first-degree relative with schizophrenia: A preliminary case series study

abstract: Social-cognitive impairments in schizophrenia are markers that precede the illness and are present in first-degree relatives of patients. Adolescence and young adulthood are peak ages of risk for the onset of schizophrenia and are important windows to observe impairments that could signify the transition to schizophrenia. To explore these risk markers, this case series study described the social-cognitive profiles of young adults at familial high-risk (FHR) and investigated their relation to symptoms of schizophrenia and schizotypy. In this study, 13 controls and 4 participants at FHR completed assessments measuring symptoms, schizotypy, emotion regulation and recognition, theory of mind, and attributional style. Participants at FHR recognized fewer sad faces than controls but did not show other impairments. Furthermore, greater symptoms and schizotypy were associated with worse performance on some social-cognitive domains. Further investigation with larger samples is needed to explore if difficulty recognizing negative emotions is a risk marker for schizophrenia.


title: Vulnerability Assessment of Machine Learning Based Short-Term Residential Load Forecast against Cyber Attacks on Smart Meters

abstract: Short-term load forecast at residential house level plays a critical role in home energy management system. While a variety of machine learning based load forecasting methods have been proposed, their prediction performance have not been assessed against cyber threats on smart meters which have been increasingly reported. This thesis investigates the vulnerability of four extensively used machine learning algorithms for residential short-term load forecast against cyberattacks, including nonlinear auto regression with external input (NARX) neural network, support vector machine (SVM), decision tree (DT), and long-short-term memory (LSTM) deep learning. The predication performances on these two datasets are compared by using NARX, SVM, DT, and LSTM. Four cyberattack models are investigated, including pulse attack, scale attack, ramp attack, and random attack.


title: Access to Justice for Indigenous Persons Being Sentenced in Ontario: An Approach to Wicked Problems

abstract: In 1996, Parliament passed s.718.2(e) of the criminal code of Canada. In doing so, recognized the injustices experienced by Indigenous populations at the hands of our criminal justice system. Nearly 26 years later, and Indigenous overrepresentation in custody across Canada is still rising. This pattern of injustice raises the question, what is stopping Indigenous persons from accessing justice? By exploring the field of access to justice and defining access to justice as containing procedural, substantive and symbolic elements, this thesis applied a unique approach to measuring access to justice based on the leading approaches of access to justice research. By focusing on the experiences of defence counsel who work within the Gladue framework of sentencing and applying an expansive conception of access to justice to guide the inquiry, this thesis attempts to shed light on the barriers to accessing justice that are faced by Indigenous persons being sentenced.


title: Assessment of Higher Order Thinking Skills in Virtual Learning Environments

abstract: This research addresses the assessment of Higher-Order Thinking Skills (HOTS), such as metacognition, reflection, and problem-solving, in Virtual Learning Environments (VLEs). We particularly focus on the use of process metrics, their combinations, and various analysis methods that allow VLE platforms to perform automated HOTS assessments. Traditional learning assessments rely mostly on outputs and are not suitable for HOTS assessment that requires process observation. As a result, it is a challenge for learners and educators to identify the areas of weakness for customized help when it comes to HOTS. Our objective is to understand the requirements of a VLE-based HOTS assessment framework and explore what process metrics can be used and how they can be analyzed to offer insight into learners' HOTS development. To achieve the above objective, a series of four studies were performed within this research. Study 1 was an initial exploratory investigation that suggested 3D VLEs as a possible HOTS fostering platform though associating their unique affordances to the requirements of common learning theories. This study was a motivational activity and initiated our research. Study 2 was performed on a text-based VLE and provided new insight into how aggregated process metrics can be used to represent student attention and participation, which are linked to HOTS. Study 3 focused on identifying 3D VLE process metrics and their alignment with HOTS components. Study 3 results suggested that the rich data coming from a 3D VLE, and the combination of process metrics as small groups (motifs) and time series, can offer more insights about HOTS. Finally, Study 4 employed motifs and time series-based similarity analysis on process metrics for performing HOTS assessment during learning tasks in a 3D VLE. Study 4 investigated task compatibility with four different similarity indexes, and findings suggested employing different similarity indexes depending on the learning tasks. Overall, the studies conducted within the scope of this research provided supporting evidence of the possibility of automated HOTS assessment on VLEs using process metrics. They showed the value of motifs (small yet meaningful series of process metrics) as a measure for HOTS. However, they suggested that there is no single method, and different learning tasks might use different data analysis strategies.


title: Reciprocal Perspective: A Cascaded Semi-Supervised Machine Learning Framework to Improve Pairwise Classification & Regression

abstract: Many real-world problems can be represented as a network, with nodes representing elements and the edges (i.e. links; or lack thereof) capturing the relationship between elements. An example domain that leverages link prediction algorithms to elucidate relationships between pairs of nodes is the task of protein-protein interaction (PPI) prediction. Leveraging high-performance computing and optimized PPI predictors, it is recently possible to evaluate every possible combination of paired nodes enabling the generation of a comprehensive prediction matrix (CPM). We introduce a novel  semi-supervised machine learning method, denoted Reciprocal Perspective (RP), which leverages this new wealth of information by extracting context-based features from this CPM by considering reciprocal views of pairwise elements for use in a cascaded classifier which has demonstrated significant improvement in predictive performance. Historically, this achievable wealth of information has been ignored due to computational intractability. We demonstrate that expending compute resources to generate CPMs is a worthy investment given the improvement in predictive performance in both  classification- and regression-type tasks.  This thesis makes contributions at all stages of a prototypical prediction pipeline. We demonstrate that RP is applicable to a variety of application domains within bioinformatics (PPI, microRNA-target, and drug-target interaction prediction) as well as within Network Science with Recommendation Systems. Furthermore, RP is demonstrated to improve individual model performance as well as function as an ensemble method to combine multiple experts. Taken together, these contributions demonstrate that RP can be broadly applied for pairwise prediction  problems across different domains, problem formulations, and varying scales of data.


title: Characterization of lysine demethylase KDM5 family: Substrate specificity and identification of potential novel non-histone substrates

abstract: A major regulatory influence over cell biology is lysine methylation and demethylation within histone proteins. The KDM5/JARID1 sub-family are 2-oxoglutarate and Fe(II)-dependent lysine-specific histone demethylases that are characterized by their Jumonji catalytic domains. This enzyme family is known to facilitate the removal of tri-/di-methyl modifications from lysine 4 of histone H3 (i.e., H3-K4me3/2), a mark associated with active gene expression. As a result, studies to date have revolved around KDM5's influence on disease through their ability to regulate H3-K4me2/3. Recently, evidence has demonstrated that KDM5's may influence disease beyond H3-K4 demethylation, making it critical to further investigate KDM5 demethylation of non-histone proteins. In efforts to help identify potential non-histone substrates for the KDM5 family, we developed a library of 180 permutated peptide substrates (PPS), with sequences that are systematically altered from the WT H3-K4me3 sequence. From this library, we characterized recombinant KDM5A/B/C/D substrate preference. Subsequently we developed recognition motifs for each KDM5 demethylase and used them to predict potential substrates for KDM5A/B/C/D. Demethylation activity was then profiled to generate a list of high/medium/low-ranking substrates for further in vitro validation for each of KDM5A/B/C/D. Through this approach, we analyzed prediction success rate and identified 66 high-ranking substrates in which KDM5 demethylases displayed significant in vitro activity towards. We further shown the ability to monitor changes in cellular methylation in a handful of the 66 high ranking candidate substrates in response to KDM5 inhibition. Specifically, we focused validation efforts on a high-ranking KDM5A novel substrate: p53-K370me3. We demonstrated significant recombinant KDM5A(1-588ΔAP) and KDM5A(1-801) activity towards the p53-K370me3 substrate in vitro. We then monitored KDM5A-mediated demethylation of the p53-K370me3/2 substrate in HCT 116 cells using a combination of wild-type KDM5A and inactive-mutant KDM5A(H483A) overexpression plasmids, along with immunoblotting, (co-) immunoprecipitation and mass spectrometry analysis. Furthermore, we have shown that KDM5A expression influences the established p53-53BP1 interaction. Finally, we identified a novel p53-TAF5 interaction dominated through the p53-K370me3 state and how KDM5A expression might affect this interaction. Ultimately, we have provided the first evidence of a KDM5 demethylase targeting a non-histone substrate for demethylation, via the novel KDM5A demethylation of the p53-K370me3 substrate.


title: Influences of Social Context on the Design of Collaborative Writing Assignments: A Case Study Analysis

abstract: Collaborative Writing (CW) is practiced widely across academic disciplines and in the business world (Lowry et al, 2004). Business schools are known for frequently using CW assignments as an instructional method (Gammie & Matteson, 2008), with the goal of improving students' writing skills and preparing them for professional responsibilities post graduation (Pettigrew et al., 2014). While business education has been widely researched (Pettigrew et al, 2014), little or no research has considered how the local influences of a business school's social context are reflected in the design of CW assignments. The present study addresses this gap, investigating how different aspects of the social context in a Canadian business school exert an influence on the design of CW assignments.


title: Canopy : "Building Towards the Future of Canada's Sustainable Forests"

abstract: The climate change crisis is slowly destroying the forest ecosystem due to the effects of extreme weather, fires, and insect infestations. In Canada, trees play an essential role in our economy by supplying lumber to the global market and as an integral part of construction. This is increasingly so as architects continue to focus their attention on the use of mass timber. In order to address these demands, it is essential to provide a solution that maintains a healthy and diverse tree culture for a thriving forest ecosystem. This thesis will address the long-term goals of forest management in maintaining a sustainable forest ecosystem in Chibougamau, Quebec. The design proposal offers a tree nursery and forestry research center, focusing on the health of trees and biodiversity by growing saplings, collecting seeds, and research towards paving the way for revitalizing the forest ecosystem as an ongoing goal for the future.


title: Examining the Temporal Stability of Evaluative Attitudes Toward Violence

abstract: Evaluative attitudes toward violence are related to violent behaviour and are important predictors of violence. The temporal stability of evaluative attitudes toward violence has not yet been examined. Attitudes have been shown to have a high degree of stability, but with the potential to change through manipulation or intervention. I assessed for the degree of stability of evaluative attitudes toward violence using the Evaluation of Violence Questionnaire (EVQ) across four days, four weeks, and three months. I found participants' EVQ scores to be highly stable across all assessments; however, the results from the weekly and monthly assessments lacked power due to small sample sizes. The results from this study do, however, give preliminary evidence that evaluative attitudes toward violence are highly stable in the short-term, and potentially also in the long-term. Future research is needed to better understand the degree of stability of evaluative attitudes toward violence in the long-term.


title: Evolutionary Tempo and Mode of Triceratops from the Uppermost Maastrichtian Frenchman Formation of Southern Saskatchewan

abstract: Previous work regarding the upper Maastrichtian Hell Creek Formation of Montana has hypothesized that two temporally separated species of Triceratops were anagenetically related, with the older T. horridus having directly given rise to the younger T. prorsus. I tested this hypothesis against two alternatives using Triceratops from the Frenchman Formation, which had not been systematically studied prior to my investigation. Using qualitative comparisons, linear discriminant analyses, and hierarchal cluster analyses I classified all specimens as T. prorsus, validating the previous hypothesis. Additionally, I relocated and provided stratigraphic data for six Triceratops specimens from the Frenchman Formation. I found no preference in depositional environment, with specimens equally distributed in both sand and mudstone facies. When relatively dated against each other, I found no trends in morphology had occurred across the latest Maastrichtian, suggesting the species may have been in evolutionary stasis prior to its extinction at the end of the Cretaceous.


title: Methylmercury Dietary Pathways and Bioaccumulation in Benthic Invertebrates of the Arctic Ocean

abstract: This study described methylmercury (MeHg) concentrations in a wide array of benthic invertebrates sampled from two locations in the Canadian Beaufort Sea (Arctic Ocean). I examined relationships between dietary indicators, specifically carbon, nitrogen and sulfur stable isotope ratios, fatty acid and fatty acid biomarker signatures, all in relation to MeHg concentrations of taxa identified using traditional taxonomy and genetic barcoding approaches. Methylmercury concentrations increased with trophic position (inferred from nitrogen stable isotope ratios), varied by feeding guild and were influenced by the type of energy sources supporting the food web. Higher MeHg concentrations were observed at a site closer to the outflow of the Mackenzie River. When accounting for the effect of feeding guild and dietary indicators, the results clearly indicated that location influenced MeHg accumulation in the benthic invertebrates. These results contribute valuable information for tracking MeHg dynamics in this region.


title: Learning Transition Dynamics via Rewarded Exploration: A Study using Unity's MLAgents

abstract: AI agents can benefit from understanding their environment and how it works, as being able to predict the state of the environment after one makes an action is useful for doing tasks. My work explores using a custom reward system to guide an AI agent in learning the transition dynamics of its environment via exploration. Due to the popularity of game engines, I focus on building a transition dynamics model using the game engine, Unity, which provides a package for making AI agents. I test the agent's behaviour across 8 studies, with different hyperparameters for its neural network and with and without access to memory via Long Short-Term Memory. I also conducted two tests with a different reward system to help judge the effectiveness of my approach. The results of my experiments show that the agent performs well and is capable of predicting a variable in the environment.


title: Vicarious Stress in Juvenile Rats

abstract: Vicarious stress occurs when traumatic events are observed rather than being directly experienced. The outcomes of vicarious stress can result in a higher incidence of negative mental health outcomes that include post-traumatic stress disorder, depression, and anxiety. Vicarious stress requires empathy to facilitate the understanding of other individuals' trauma and suffering, and this is influenced by factors such as familiarity and similar past experiences. To study vicarious stress in rats and mice, a rudimentary form of empathy called emotional contagion, enables these animals to mirror the emotional states of each other, particularly during distress. This requires one animal, the witness, to observe a conspecific endure stressors, from a place of safety. The study of vicarious stress in rats and mice during the juvenile period is sparce, though this critical period of development is vulnerable to stressors that can lead to long-term effects like increased anxiety- and depressive-like behaviours. This thesis furthers the preliminary investigation on how vicarious stress can be studied in juvenile animals and the long-term behavioural changes following these stressors. Considering this it is hypothesized that vicarious stress experienced during the juvenile period will elicit emotional contagion, leading to a sensitized HPA-axis and long-term deficits on exploratory and anxiety-like behaviours in adulthood. Two models of vicarious stress during the juvenile period were implemented, a novel model modified from an existing juvenile stressor model (Chapter 2), and observational fear-learning, an established model implemented in adult rodents (Chapter 3). In adulthood (Chapter 2) and in early adolescence (Chapter 3), the long-term behavioural impacts on exploration, social interactions and fear expression and the HPA-axis reactivity were determined. In Chapter 3, age differences between the juveniles and adults in male and female rats and the impact of past stressor experience in witnesses were explored. The findings revealed that vicarious stress does occur in juvenile rats, and it is not dependent on familiarity, yet it does require past stressor experiences for full behavioral display. Importantly, the extent of emotional contagion, confirmed by fear expression, is lower in male juveniles than it is in male adult rats.


title: Connected Line Recovery and Maintenance by Programmable Matter

abstract: Several different distributed computational universes have been considered and studied within the interdisciplinary field called Programmable Matter. In this field, the matter is envisioned as a very large number of micro and nano-sized computational entities with limited capabilities programmed to collectively perform a task without the need for any central or external intervention. Within distributed computing, several theoretical active and hybrid models for programmable matter have been proposed. Within these models, a central concern has been the formation of geometric shapes; among them, the line is especially important. An important requirement, common to most research, is the connectivity of the operating elements at all times. In the extensive literature on the problem of shape formation in programmable matter systems, it is almost generally assumed that the system elements never fail. Hence the problem of reconfiguring the shape following the failure of some elements has been neglected. In this thesis we studied the problem of handling failures when the shape is the line. We considered first of all the Connected Line Recovery problem requiring the non-faulty elements to restore the line shape following the failures of some of the elements. We examined the instance of this problem in the programmable matter systems defined by the Metamorphic Robots and Amoebot models. We then studied the more complex Dynamic Line Maintenance problem when the faults are fully dynamic (i.e., can occur at any time). We examined the instance of this problem in the systems defined by the Amoebot and the Hybrid Programmable Matter models. For both problems and the systems considered, we provided a near complete feasibility characterization of problems, identifying the conditions necessary for their solvability, and constructively proving the sufficiency of those conditions. In particular, we presented solution protocols that operate correctly, maintain connectivity of the non-faulty entities, without constraints on the number of entities that will become faulty, nor on the location, nor (in the dynamic case) on the time of the occurrence of each fault. Our impossibility results hold even under the weak fully-synchronous scheduler, while the possibility results hold under the more difficult semi-synchronous one


title: Queer Geographies of 1970s Barcelona: Mapping the City in Transition through Image and Oral History

abstract: Space was a central concern in 1970s Barcelona, both for the Francoist dictatorship trying to maintain control of the city as well as for the gay, lesbian, and trans activists defying the repression of the regime. How to occupy space was a source of heated debate among these activists as a political transition to democracy was sought with uneven success in the Spanish State. This thesis analyzes photographs of marches and oral history interviews to argue that space was crucial in creating solidarities and delineations within and among identity categories. This analysis looks beyond commercial sites to investigate the relationships between spaces to demonstrate that it was through an engagement with the spatial politics of Barcelona and its geography in the Transition* period that lesbian, gay, and trans individuals articulated their political and personal identities.


title: It's Dangerous to Go Alone: An Ethnography of Friendship Through Tabletop Gaming Communities of Practice

abstract: As the world continues to move online in the 21st century, in-person communities of practice continue to thrive in game stores, libraries, campuses, and in personal homes. In these spaces, and many others that are too varied to name, people engage with tabletop roleplaying games as members of groups of adventurers. Individuals come together to create identities, craft narratives, and build connections with one another that continue even after the game ends. This paper examines the ways that these communities of practice are constructed and maintained by the diverse group of individuals who inhabit them, and how they come to construct identities and meaning through their engagement. Over the period of 18 months between 2017 and 2019, participant observation fieldwork was conducted with various tabletop roleplaying game groups across the Ottawa, Ontario area. This took place at game stores, campuses, libraries, people's homes, and restaurants to understand the ways in which people come together in-person to play games such as Dungeons and Dragons and Pathfinder. Interviews were simultaneously conducted with individuals from these groups to develop life-histories of some of those involved in these communities. What was found throughout this research was that individuals were coming together to play games, but more importantly to develop a sense of belonging and to build communities of practice with other like-minded game players. This has informed a dissertation which may more accurately be labeled an 'ethnography of friendship', and which analyses (1) the role of play in the lives of members of communities of practice, (2) identity as it is constructed through performances as people engage in roleplaying activities, and (3) the role of in-person communities and friendships in an increasingly digital world. As we increasingly rely on digital technologies and online worlds to foster our relationships, many people still seek in-person communities. This has been made clearer with the easing of social distancing restrictions and lockdown orders following the COVID-19 pandemic, as individuals have quickly moved to rebuild the in-person communities of practice that were put on-hold for the past 2 years.


title: Differential Impact of the Global Financial Crisis: Explaining the Cross-Country Real Impact and “Advanced Economies Nature” of the 2008–2009 Crisis

abstract: This dissertation advances the literature on the cross-country differential real impact of the 2008-2009 Global Financial Crisis (GFC), and explains the apparent "Advanced Economies (AE) Nature" of the crisis. The literature's AE Nature result finds higher levels of pre-crisis income (logged per capita GDP) correlating with worse GFC-outcomes; but it does not address why this is so. Dependent variables (DVs) here measure GFC outcomes as the depth and duration of the peak-to-trough contraction in seasonally adjusted quarterly real GDP within 2007-2010. Following an introduction, Chapter 2 shows that the linear income relationships on both DVs represent spurious results, better characterized by a step-function between better performing lower-middle-income countries (LMICs) and similarly worse-off upper-middle-income and high-income countries (UMICs and HICs). Chapter 3 then undertakes a step-wise regression specification search on a broad set of pre-crisis independent variables (IVs), excluding those directly related to income. The search process addresses methodological issues found in the literature, including omitted variable bias, contingent significances, outlier influence, multicollinearity, and heteroscedasticity. IVs considered expand on those tested in the literature, newly adding measures for 2003-2007 "boom-period" growth for most indicators. Six IVs explain 75 per cent of depth DV variation: credit boom; manufacturing share of exports; FDI assets boom; food, fuels and mining share of exports boom; government expenditures boom; and an exchange rate regime dummy. Two IVs explain 46 per cent of duration DV variation: foreign debt liabilities; and bank assets boom. The models explain-away the AE Nature, in both LMIC-difference and linear-income forms. The depth model also explains an emerging Europe difference identified in the literature. However, several extreme outliers on the raw depth DV remain poorly-explained, including Ukraine and the Baltics. Chapter 4 undertakes comparative case studies on Ukraine and Latvia, paired with Romania and Belarus, respectively, as otherwise similar cases that are well-explained by the regression model. The analysis identifies factors helping explain Ukraine and Latvia's extreme contractions, primarily reflecting their different experiences-of and responses-to balance of payments crises.


title: Conformal and Flexible Leaky-Wave Combline/Rampart Hybrid Antenna Arrays

abstract: A novel bent-stub hybrid combline/rampart leaky-wave antenna (LWA) is designed and fabricated on a flexible polyethylene terephthalate (PET) substrate, and experimentally verified on flat and curved surfaces. The open stopband (OSB) of a combline structure is suppressed with asymmetrical stubs. Meandering is then introduced in its feed and increases gain and scan range. The meandering is a discontinuity itself known as a rampart antenna and contributes to the radiation. Finally, the antenna is utilized in an array where the combline LWAs are offset by half of a period and intertwined. Mutual coupling is controlled by bending the UC stubs and optimizing antenna separation and is shown to reduce any discontinuities in the gain around the broadside frequency of the LWA array. The designs are manually fabricated on a PET substrate and tested, demonstrating good agreement with simulations. Antennas were shown to retain good performance at bend radiuses of ±1000 mm.


title: A Holistic Approach to Structural Health Monitoring of Composite Aerospace Structures using Lamb Waves: From Manufacturing to Service

abstract: The successful application of a structural health monitoring (SHM) system for composite aerospace structures requires a holistic approach encompassing the full life cycle of the structure. Important capabilities of an SHM system include: 1) recognition, 2) identification, 3) severity, and 4) location of a defect. This was achieved, first, by designing a novel manufacturing method to co-cure piezoelectric sensors to the surface of carbon fibre reinforced polymer (CFRP) panels, allowing for in-situ cure monitoring, manufacturing inspection, and in-service monitoring. Second, numerical and experimental techniques used Lamb wave propagation to recognize and identify multiple types of manufacturing defects and determine the severity of a delamination defect. A comparison of co-cured and bonded piezoelectric sensors showed similar waveform shape, Lamb wave propagation velocity, and signal amplitude for the anti-symmetric Lamb wave mode. Performing a time-frequency domain analysis using the continuous wavelet transform demonstrated the ability to recognize and identify delamination, porosity, and foreign object defects. To determine the severity of a delamination defect, five input signals were compared and it was determined the Mexican hat excitation provided the best average main lobe width resolution and signal-to-noise ratio over a range of frequencies, particularly at lower frequencies. Finally, a multiple level discrete wavelet transform decomposition was able to provide signal compression, up to 450 times, while still maintaining the important signal features to determine the severity of a delamination defect. This allowed both the length ratio and depth sequence of multiple delamination defects to be correctly identified. The practical approach of this research to focus on the manufacturing process and manufacturing defects provided an important step towards a holistic SHM system for CFRP structures.


title: Methods of Printing Passive Analog Beamforming Devices

abstract: Analog beamforming is the process of controlling the amplitude and phase distribution across an antenna array to produce focused EM radiation. There are many ways of accomplishing this, but this thesis focuses on printing techniques to produce beamforming devices. The methods of production used for this work includes 3D polymer printing, PCB fabrication and knife tracing with copper cladding and tape. Three types of devices are designed and fabricated for this work including Luneburg lenses, Butler matricies and ferroelectric varactors. The Luneburg lenses are produced through 3D printing processes and measured in the far-field using with an anechoic chamber. Two different Butler matricies are designed and presented, one is designed at 2.4 GHz on Rogers 3006 substrate and fabricated using a knife tracing printing process. Radiation pattern measurements are made for this matrix in the far-field using an anechoic chamber.


title: Intersectionality: Gender and Race in the Court

abstract: This study investigated the effects of defendant gender (man/woman) and race (Indigenous/White) on Canadian mock jurors' verdicts in a case of parent-perpetrated child neglect. The potential intensified negative consequences against Indigenous women, produced by the intersectionality of gender and race, were of particular interest. Four hundred and one participants read a mock trial transcript, provided verdicts on two charges, and rated the defendant on a variety of adjectives. Logistic regressions revealed mock jurors were not influenced by the defendant's gender or the interaction between the defendant's gender and race. Race had an unpredicted influence, with an Indigenous defendant receiving fewer guilty verdicts. The adjective ratings moderated the effect of gender on verdicts, but not race. Mock jurors were less likely to find a woman guilty when they held positive impressions of her. This study contributes to previous literature that suggests jurors' verdicts may be influenced by extralegal factors.


title: Airport Landside Vehicle Modelling and Pedestrian Behaviour Modelling for the Connected and Automated Era

abstract: This research examines the current state of the airport landside operations using microsimulation models to help understand how these areas will change with the introduction of connected and automated vehicles. Data collection from an existing North American commuter airport curbside was conducted to support this research. The curbside models provide comparisons of capacity and estimates of level of delay to travellers based on the different uses of space for the curbside. The analysis of the travellers' journey is explored further by following their path through the pedestrian access corridor between the curbside and the airport security. Data of pedestrian movement speeds and total travel time within the corridor were collected. This was modelled to understand the impact of dynamic changes to desired walking speeds. The combination of the collected data and models gives a complete overview of the airport travellers' journey between the curbside and airport security.


title: On Applications of Topological and Combinatorial Methods to the Theory of Groups

abstract: Graphs are topological objects called 1-dimensional CW complexes, and their fundamental groups are free groups. More generally, any group can be represented by a 2-dimensional CW complex, which is a graph with discs glued along the boundaries of closed paths corresponding to relations in the group. These objects can be studied from the topological viewpoint of covering space theory, introduced by John R. Stallings, which allows us to "visualize" groups and determine their subgroup structure. Alternatively, graphs can be studied from a combinatorial point of view, developed by Ilya Kapovich and Alexei Myasnikov, which provides simple algorithms that answer questions about free groups. We give an exposition of both approaches and demonstrate how they are used to answer questions about subgroups of free groups and free products.


title: Design Optimization of Hybrid Battery Based Gensets

abstract: This thesis proposes an analytical method using a lithium-ion battery and generator data to provide insights into a hybrid genset's optimal operational load, peak shaving, and fuel consumption difference with a standalone genset. The overview analysis is between the standalone genset and a battery-fused diesel generator. Further investigations into other factors play a significant role in the results, including power output (%load), battery depth of discharge, battery charge and discharge time, battery total cycle and life span of the battery. A numerical simulation was carried out to monitor the hybrid genset operation, whereby the battery depths of discharge and the number of cycles were compared. Another simulation is performed to find the incremental results for a 135 kw genset by varying the different battery depths of discharge and the generator load difference. The combined results proved that the battery units will always generate adequate efficiency support for gensets.


title: Modelling the Accuracy Rates of Spatial Relational Reasoning Problems: An Analysis Facilitating ACT-R and PRISM Theory

abstract: This thesis models the effects of errors of omission and commission due to increased working memory demands on accuracy rates of spatial relational reasoning problems. The questions modelled are taken from the Multidimensional Relational Reasoning Task (Cortes et al., 2021). Four models were created using Python ACT-R and PRISM theory which demonstrated the negative relationship of increased premises and dimensions per problem on accuracy rates. Results highlight the need for future modelling to consider the individual differences in micro-strategy preferences, how reasoning processes may be affected by different memory errors, and how future measures may be constructed to better address raised concerns.


title: Inverse Greybox Virtual Metering Algorithms to Visualize Building Energy Flows

abstract: Energy submetering at the equipment level provides a tool to control energy consumption and improve equipment energy use. Virtual meters (VMs) are a cost-effective alternative to physical meters that can capture unmetered energy flows at the equipment level and provide building stakeholders with details that support their operational decisions. The virtual metered energy can be presented through interactive visualizations that allow users to interact with the graphical representations based on their operational needs to gain insights that would facilitate decision-making processes. This thesis aims to develop a suite of virtual metering algorithms to characterize unmeasured energy flows across critical heating, ventilation, and air conditioning components and present the virtual metered energy through effective visualizations that allow user interaction to gain insights into building operational decisions. To this end, the thesis structure consists of three main parts that develop equipment-level virtual meters and a standalone visualization tool to visualize the virtual metered energy. In this first part, an integrated inverse greybox AHU model is developed using data collected from a highly instrumented AHU serving an academic building in Ottawa, Canada. Optimal values of model parameters are used to create VMs that estimate the heat supplied by the heating coil, the heat extracted by the cooling coil, and the heat gains due to the supply fan. In the second part, VMs that estimate the heat added by zone-level perimeter radiant heaters are developed using steady-state, transient, and load disaggregation inverse modelling approaches. The models are trained using data collected from 18 zones in an academic building in Ottawa, Canada. The accuracy of the VMs is assessed by comparing the heat estimated by the VMs to measurements obtained from physical meters installed in the 18 zones. The modelling approaches' performance is evaluated by comparing model inputs, data processing, and the accuracy of the VMs. The third part utilizes the virtual metering algorithms presented in the first two parts in developing a standalone interactive visualization tool that illustrates equipment-level virtual metered energy trends. The potential of the visualization tool for assisting decision-making processes and improving building energy performance is demonstrated through illustrative examples.


title: The Development of a Highly Insulated, Thin Wall Assembly for Canadian Residential Construction

abstract: The Canadian buildings sector is responsible for 13% of greenhouse gas emissions in Canada. As such, mandatory and voluntary building codes are becoming increasingly stringent on requirements for highly insulated wall assemblies to reduce building heating loads, thereby reducing emissions. However, traditional means of insulating a wall significantly increase its thickness and in scenarios where the building's footprint is constrained this causes a decrease in indoor living space and a reduction in the home's market value. To address this, this thesis proposes thin, highly insulated wood-frame wall assemblies which incorporate highly performing insulation materials. A variety of such novel wall assembly designs are developed and modelled for thermal performance. Three of these designs are tested using the guarded hot box method described in ASTM C1363. It is found that the proposed wall assembly designs provide sufficient thermal performance with little increase in wall thickness compared to traditional wood-frame walls.


title: Safety in Cameras? – An Exploratory Study of the Ottawa Public Surveillance (CCTV) Project

abstract: This thesis examines the Ottawa Public Surveillance Project announced in July 2019 as planned for the ByWard Market, but never implemented. The thesis relies on frame analysis of news articles and public documents, 11 open-focused interviews with people supporting or opposing the initiative, and social media data. The project was framed as a response to violent crime, but many Ottawa residents understood and promoted surveillance in the ByWard Market as a deterrent for the presence of marginalized people from the area more generally. Other nuances in public support for and opposition to CCTV are examined. My research unearthed that the Ottawa police quietly dropped the project, and, in an internal document, stated CCTV was not an evidence-based best practice, although the provincial government and other Ontario police forces continue to promote CCTV. Organized resistance in Ottawa likely played a role in stopping the project, and implications of this are discussed.


title: Transcriptomic Dose-Response Analysis in Zebrafish Embryos to Estimate Aquatic Toxicity of Plasticizers and Plastic Monomers

abstract: Current toxicity tests have high monetary costs, efficiency issues and ethical concerns. New approach methodologies, such as transcriptomic dose response modelling (TDRM), are increasingly being used to address these issues. This thesis aimed to combine the TDRM method with an acute zebrafish embryo model exposure to determine effective concentrations for chemicals of concern (plasticizers and plastic monomers). We hypothesized that the TDRM methodology would be more sensitive and informative than traditional apical endpoints derived from acute fish exposures. We found that transcriptomic endpoints were more sensitive than apical endpoints for the majority of chemicals tested. However, several challenges related to experimental design and RNA sequencing were encountered and recommendations were given for future studies to address these challenges. Overall, the TDRM methodology, when combined with the zebrafish embryo model, shows promise as an effective tool for screening and prioritizing chemicals of concern.


title: Navigating the Digital Jungle: Social Media's Relationship to Journalism

abstract: This thesis is an examination of the relationship between journalism and social media. It begins by exploring the current landscape of journalism in the digital age and to what extent the benefits of social media are being harnessed by journalists, and what can happen when social media is misused by journalists. It continues with analyses of interviews with eight practicing journalists on their experiences working with social media and their employers' expectations of them. This thesis maintains that, despite its downfalls, social media remains a valuable tool for reporters and newsrooms. It also recognizes that there is a significant gap in communication when it comes to the expectations of how social media should be used by journalists and how they are currently using it. It concludes with a proposal of emerging best practices and potential stipulations for the future implementation of newsroom social media policies.


title: Effective Explainable Artificial Intelligence using Visual Explanations in Images

abstract: Convolutional neural networks (CNNs) outperformed machine learning in image classification. Their human-brain alike structure enabled them to learn sophisticated features while passing images through their layers. However, their lack of explainability led to the demand for interpretations to justify their prediction. Explainable AI (XAI) proposed collaboration between technology and humans to provide more insights into CNNs. This study presents a novel explainable model called Augmented Score-CAM, built on top of the existing Score-CAM and the existing image augmentation techniques. This model adopts the image augmentation approach by producing augmented class activation maps and merging them into one activation map. In addition, we introduce a novel taxonomy analysis for XAI models that interpret CNNs. The taxonomy categorizes the models into architecture modification, architecture simplification, feature relevance, and visual interpretations. After that, we review XAI evaluation metrics, application areas, and tasks. In the end, we discuss XAI challenges and address some concerns, and provide suggestions to improve their performance. This study improves AI systems interpretation by adding Augmented Score-CAM visual explanations. Furthermore, we highlight the importance of incorporating visual explanations in AI systems to improve user trust in decision-making.


title: Investigation of Daily to Seasonal Variation in Greenhouse Gas Emission and Cycling in Agricultural Riparian Zone Soils

abstract: Agricultural riparian zone microecosystems provide opportunity for mitigation of pollution transport and greenhouse gas emissions. In order to make recommendations to farmers as to best management practices, temporal variations in gas fluxes between the soil and atmosphere must be considered, and the controls on soil-gas behaviour must be better understood. In this study, CO2, O2, CH4, and N2O subsurface concentrations and surface fluxes were monitored with an average temporal resolution of 4 hours, along with soil temperature, soil moisture content, and barometric pressure from the beginning of May until the end of November 2021 at an active, arborous, agricultural riparian zone in St. Albert, Ontario. The results show varying control of barometric pressure, soil temperature, and moisture content on short-term changes in soil gas concentrations and emissions depending on the overall environmental conditions under which these changes in controlling parameters occur.


title: Trans*Vocal: Documenting Gender Subjectivity Through Changing Vocality

abstract: Through my subjectivity as a non-binary, trans* vocalist, I am acutely aware of the sounds I have been enculturated to produce. Drawing on theories of vocality (Eidsheim 2019; Azul 2015), transition (Constansis 2013; Constansis and Foteinou 2017), and improvisation (Caines 2021), I analyze the relationship between voice and perceptions of gender by exploring the concept of transition as it is performed by my voice during the first seven and a half months of testosterone treatment (mid-June 2021 - January 2022). I contextualize my experience within historical and medical notions of gender and examine it through autoethnographic methods and creating an experimental music video, Trans*Vocal. I open up and make myself vulnerable in the hope that greater knowledge of trans* experience will bring appreciation for "non-normal" vocalizations. I aim to problematize our current language surrounding gender, voice, and transition and depict transition as a natural part of anyone's vocal journey.


title: Investigating the Utility of self-Explanation for Learning to Program through Translation Activities

abstract: Programming is challenging for novices to learn. Code tracing is a foundational programming skill that involves simulating a program's execution. Translating lines of code into plain English explanations of what it does should allow students to better understand a program while code tracing. Translations is similar to self-explanation, a general mechanism that helps learning by making inferences beyond the instructional materials. This thesis investigates whether self-explanation via translation of programming syntax to plain English helps students learn to code trace, in a between-subjects study (\emph{N} = 44). We created two versions of a computer tutor that guides novice programmers through code-tracing problems. In the experimental condition, students were asked to translate lines of code during code-tracing activities, while in the control condition students were only asked to code trace. The experimental group performed significantly better on translation and code-generation questions, but the control group performed significantly better on code-tracing questions


title: Square Peg in a Round Hole? Three Case Studies into Institutional Factors Affecting Public Service Whistleblowing Regimes in the United Kingdom, Canada, and Australia

abstract: Whistleblowing is an important prosocial activity, one which facilitates the early detection and correction of misconduct and deters future misconduct. Recognizing this, many governments have signalled its legitimation by enacting legal protections for public sector whistleblowers, including in the Westminster governments of the United Kingdom, Canada, and Australia. The success of whistleblowing regimes in these jurisdictions is contested, however, as mismanaged programs and retaliation against whistleblowers continue to make headlines. This presents a conundrum. Previous studies have established that if failures accumulate and visible successes are few, employees will lose trust in the regime and use it less, if at all. This would constitute a public policy failure and undermine the implicit long-term goal of improved governance. Departing from previous research approaches, this dissertation uses historical and rational choice institutional theory to test the hypothesis that whistleblowing regimes are born of crisis, but the extent to which they are effectively implemented is dependent on ongoing bureaucratic and political support. This support is contingent upon the regime being consistent with existing institutional arrangements and incentives. When it is not, dysfunctional responses to whistleblowing will continue. Three case studies are presented in order of regime enactment, with the United Kingdom in 1998, Canada in 2005, and Australia in 2013. Process tracing was used to examine three embedded units of analysis: pre-regime institutional development, whistleblowing regime implementation, and the factors effecting regime performance. The findings partially confirm the hypothesis. The whistleblowing regimes followed a similar pattern, but there were two triggers for whistleblowing legislation - punctuated equilibrium after a crisis, or isomorphism to boost legitimacy, driven by political exigencies. Support is fleeting, moreover, as political actors quickly shift their attention to different priorities. Administrative actors adopt several strategies to resist the regimes, including shaping them to be less threatening, unenthusiastic enforcement, and continued reprisals. Although the regimes do conform to Westminster conventions and norms, these have been eroded as political actors have intruded into administration and taken control of incentives. These favour responsiveness to political direction and the suppression of bad news, undermining the intent and performance of the whistleblowing regimes.


title: On Bayesian Inference for Markovian Queueing Models

abstract: We are concerned with an M/M/- queueing model. Particularly, we focus on such models with join the shortest queue policy and N parallel queues. Assuming the steady-state case, a Bayesian paradigm is used in estimating the queueing system's parameters when full data or only queue lengths data are provided. We start with the case N=2 queues and found maximum likelihood estimators and Bayesian estimators for the system's parameters when full data about arrival times, departures times, and jobs' paths is provided. When only queue lengths data is provided, we estimate the traffic intensity of the JSQ-2 model using its asymptotic behaviour studied by Flatto [46]. Also, we provide Bayesian estimation for the traffic intensity using a new approximation to JSQ-2 queue length distribution. Indeed, a generalized bivariate geometric distribution (as proposed by [48]) is employed with an improper prior and a new proposed generalized bivariate beta distribution. When N is large enough, using the mean filed performance of the JSQ-N studied by Dawson et al. [47], we estimate the traffic intensity of JSQ-N model considering both maximum likelihood estimators and Bayesian estimators with different prior beliefs of the parameters. Numerical results are provided to show the accuracy of our estimators for JSQ-N for both cases N=2 and large enough N. Furthermore, we introduce a first study of privacy preserving analysis on a sensitive data released by a queueing model M/M/1. In fact, we propose, in the context of Differential Privacy [56], a Bayesian framework, inspired by [58], to generate private synthetic data, private service and arrival time rates from M/M/1 queueuing data. Keywords: Bayesian inference, Queueing models, Differential Privacy, Join the Shortest Queue (JSQ), Generalized bivariate beta distribution, Mean filed performance.


title: Deep Reinforcement Learning for Quantitative Finance: Time Series Forecasting using Proximal Policy Optimization

abstract: In this work, the focus is on price prediction and concurrent strategy building. The modelling approach chosen for this is of the deep reinforcement learning type, and actor-critic class. Specifically, in this work the proximal policy optimization (PPO) architecture is employed individually on each stocks market history in order to try and solve the price prediction problem. A custom RL environment was built to run the proposed experimental sequence and to test which parameter values should be used in regards to learning rate, discount factor, feature space, action space, and look-back length. These values were subsequently used for experiments on different datasets, exploring the portability of the model, effect of transfer learning, as well as portability of the parameter configuration. The results show our experimental sequence can be effectively used for the price prediction problem, and in some instances outperform a practical B&H strategy.


title: Temporal and Spatial Impacts of Extreme Weather Events on Winter Wheat and Milling Oat Yields in Southern Ontario

abstract: This is a comprehensive study of extreme weather events in southern Ontario from 1950 to 2017, and their impacts on winter wheat and oat yields. Trends in temperature and precipitation were evaluated annually and seasonally. There were significant shifts toward increased warming, growing season length, and the frequency of precipitation events. Warm and precipitation extremes are increasing in intensity, duration, and magnitude. Random Forest regression was used to investigate how different extreme weather indices were related to winter wheat crop yield, across crop pheno-phases and controlling for soil texture. Crop-specific indices were important indicators, explaining 40% of yield variance. Winter Warming Index was the most important index in the RF model, linked to a 72% increase in mean square error when removed. Changing extreme weather distributions in southern Ontario seems to be increasing potential negative impacts on farming winter wheat and milling oats, so adaptive plans should be considered.


title: The Virtual Reality Questionnaire Watch: Exploring Novel Methods Integrated with Google Forms

abstract: We developed A Questionnaire Toolkit that integrates Google Forms questionnaires into a VR environment. The toolkit's VR environment provides a watch that spawns the Google Forms questionnaires and a task setup for researchers to use in their studies. We conducted a user study to evaluate the self-reported presence, task load, and usability of the Questionnaire Toolkit versus Google Forms on a tablet. The results showed similar presence and usability scores but a higher physical demand and task control for the in-VRQ condition. Participants preferred using the Questionnaire Toolkit in VR experiences over Google Forms on a tablet and highlighted the benefits of using in-VRQs. We also conducted a walkthrough to discover usability issues researchers could face when deploying the Questionnaire Toolkit. Walkthrough participants uncovered several usability issues. Researchers can deploy the toolkit on their devices with the developer's help.


title: Application of Wireless Signal Scanning in Traffic Studies

abstract: With advances in communication technologies, innovative traffic data collection approaches have been developed. A means for this purpose is wireless technology which is sufficiently widespread among road users. Traffic data may be collected using signal scanners detecting wireless signals in the vicinity of them. As the data provided by signal scanners involve no direct information about the position of the signal source, the applications of this technology in traffic studies have been limited to finding some parameters in certain situations. The purpose is developing the applications of wireless signal scanning in traffic studies which require positional data of road users. This is achieved utilizing the potentials of received signal strength indicator (RSSI) of wireless signals transmitted by personal smart devices. Wi-Fi, Bluetooth Classic and Bluetooth Low Energy are three widespread signal modes, transmitted by popular beacons used in daily life. A comparative study of the field performance of these signal modes is conducted, investigating their characteristics important in gathering traffic flow parameters whenever positional data of road users are required. This provides the possibility of selecting the most suitable signal mode for the intended applications of the technology based on the requirements of the methods. A technique for positioning of beacons based on their transmitted signals, applicable in transportation studies is developed. This technique provides the possibility of positioning in intersections and their surrounding areas as well as congested road segments. The technique is based on the strength of signals transmitted by beacons, creating radio maps, and applying an algorithm called k-nearest neighbors. The procedure is optimized, and the accuracy and functionality of the technique is improved via modification of the system arrangement and application of proper filtering algorithms. A method for detection and classification of turning movements applicable in small urban intersections is developed based on wireless signals. The method utilizes the time profiles of the RSSI values of the signals emitted by beacons carried by turning vehicles. The signals are collected by an array of signal scanners carefully located on the intersection approaches. Turning movements are classified comparing signature points of the RSSI-time profiles and their occurrence moments.


title: The Prevalence of Ethnobotanical Data Inclusion in Linguistic Documentation in Dictionaries from 1960 to 2020

abstract: This paper examines the role linguists play in the preservation of biocultural diversity by attempting to measure the extent that linguists include ethnobotanical information in language documentation works like dictionaries. This study analyzes various types of dictionaries, on different languages, and compares them to literature on what is recommended for inclusion. The primary method of analysis consists of assessing what types of information are typically included or excluded as well as if factors like year of or type of publication affect inclusion. Relevant entries from each dictionary are listed in the appendices. The global community is seeing increased threats to biological, cultural, and linguistic diversities and there are increasing developments suggesting their interconnectivity. As such, is it vital to assess what documentation measures are being taken, if they are producing desired results, and if not, why. Understanding the results and seeing changes over time will help guide future efforts.


title: Wastewater Surveillance of SARS-CoV-2 at a Canadian University Campus and the Impact of Wastewater Characteristics on Viral RNA Detection.

abstract: SARS-CoV-2 levels in the wastewater of a Canadian university campus and their residence buildings were monitored to identify changes, peaks, and hotspots of COVID-19 transmission and search for associations with campus events, social gatherings, long weekends, and holidays. Wastewater signals largely correlated with clinically confirmed cases, often increased following long weekends, and decreased after the implementation of lockdowns. Furthermore, the impact of wastewater parameters on SARS-CoV-2 detection was investigated, and the efficiency of ultrafiltration and centrifugation concentration methods were compared. Results indicated more sensitive results with the centrifugation method for wastewater with high solids content and with the ultrafiltration method for low solids content. Wastewater characteristics from the building sewers were more variable than overall campus wastewater. Statistical analysis was performed to manifest the observations. Overall, wastewater surveillance provided actionable information and was able to bring high-risk factors and events to the attention of the decision-makers, enabling timely corrective measures.


title: Knockout of DROSHA Increases the Sensitivity of HCT116 Cells to Apoptosis in Response to Actinomycin-D Treatment

abstract: MicroRNAs are short non-coding RNAs that function as sequence-directed post-transcriptional inhibitors of gene expression. The cellular response to ten drugs including actinomycin-D (ACT-D) was examined in a genetically modified HCT116 colon cancer cell line with a deletion in the gene encoding a critical miRNA processing enzyme called DROSHA. We found that the DROSHA-null subline was more susceptible than the parental cells expressing wild-type DROSHA to apoptosis induced by several drugs, most prominently ACT-D. This increase in susceptibility to apoptosis was characterized by increased DNA-fragmentation, increased caspase-3/7 activity, and loss of membrane integrity. The increased susceptibility to apoptosis was not associated with differences in DNA-synthesis, RNA-synthesis, protein-synthesis, metabolic activity, p53 response or the induction of replicative-senescence. Our results suggest that these cell lines are equally sensitive to the direct effects of ACT-D but these DROSHA-null cells are more sensitive to apoptosis induced by a subset of drugs exemplified by ACT-D.


title: Digital Dictators: How Different Types of Authoritarian Regimes Use Cyber Attacks to Legitimize Their Rule

abstract: As states and populations around the world have become increasingly interconnected and dependent on digitized technologies and cyberspace, threat actors have been aggressively exploiting these changes to their own advantage. Of particular concern to academics, cyber experts and national security practitioners in the West, has been the rapid proliferation of damaging and disruptive cyber attacks carried out by state-actors - particularly authoritarian regimes - and their proxies. Despite global cyber attacks rising year by year, in terms of both frequency and level of technological ability, available data suggests most of the world's major cyber attacks are carried out by a relatively small handful of states. Furthermore, it appears as though these states tend to favour certain types of cyber attacks over others. This observation leads to the central research question of this dissertation: why do certain types of authoritarian regimes tend to favour certain types of cyber attacks over others? Taking a deductive approach, and drawing from existing theories on authoritarian legitimation and cyber conflict, I have developed a needs-based theory of authoritarian behaviour in cyberspace. More specifically, I suggest that different types of authoritarian regimes will use different cyber strategies to fulfil or service the process, strategy, or outcome they need most to maintain domestic support and legitimacy.


title: Investigation of Passive Safety Methods for Nuclear Reactors

abstract: This thesis considered two passive safety measures: plug formation and heat pipes. During a reactor core meltdown, the molten corium material can access cooling pipe connections. There is a chance that the passive plugging of melt flow due to solidification can occur, provided there is an adequate heat sink. A numerical model was created to simulate corium flow through an empty vertical pipe. The numerical model was validated through experimental work using gallium and verified using a previously built analytical model. Heat pipes are passive, two-phase heat exchangers with excellent heat transfer capabilities. They can be used in passive reactor core cooling and spent fuel pool cooling. Heat pipes have different operating limits that impact their operating conditions and heat transfer capabilities. A numerical approach was used to determine the operational limits of a liquid metal heat pipe that can be used in nuclear applications.


title: Seeking Awareness of Our Selves and the Environment Through Vocal Improvisation in The Singing Field

abstract: /Users/nicolaoddy/Library/Mobile Documents/com~apple~CloudDocs/Carleton University Cloud/Dissertation/Dissertation Defence/100310735_Oddy_N_Abstract.pdf


title: Spatial and temporal variation of microplastics in the Ottawa River watershed with citizen science as a complementary sampling methodology

abstract: Microplastic concentrations were investigated in water and sediment in the Ottawa River watershed in Quebec and Ontario, Canada. Microplastic concentrations were measured temporally during precipitation events in an urban creek in the City of Ottawa and on the main channel of the Ottawa River within the Ottawa/Gatineau urban area. The temporal events sampled included heavy rainfall, snowfall and snow melt with microplastic concentrations measured from these events compared to concentrations during non-precipitation events. The results showed sewage overflows contribute to large short-term inputs of microplastics to the Ottawa River, however, spring snowmelt presented the highest increase of microplastic concentration for both the urban creek and main channel of the river. Additionally, the research examined the spatial distribution of microplastics in river water throughout the Ottawa River at 105 sample points on the main channel and tributaries. An ANCOVA analysis demonstrated only two significant spatial factors related to microplastic concentration, with distance downstream from the river source and an increase of microplastics at boat launch locations. However, these were both only weak relationships. The research incorporated two citizen science projects to investigate microplastic concentration in water and sediment in the Ottawa River watershed, while evaluating the potential of citizen science as a complementary sampling tool for microplastic research. With robust project design and implementation, citizen science is an excellent complementary tool for examining microplastic concentration in freshwater environments as it can reduce research costs, while increasing spatial scope of microplastic projects. Additionally, increasing citizen science capacity in microplastic research and monitoring is a useful tool to engage volunteers and involve them in environmental education while contributing to advancing the understanding of microplastic pollution.


title: Novel Scalable Metasurface Control System

abstract: A low cost controller was designed, simulated and tested in order to meet the requirements of bias control for active metasurfaces. The controller was required to set the bias elements on arbitrary metasurface designs containing both PIN Diodes and Varactors. This controller has a distributed architecture allowing it to be scaled to any metasurface required, while being easy to integrate into future metasurface designs. Programmatic control was achieved through a Python script in the same environment as test and measurement equipment, allowing for a fully automated experimentation setup. This controller was then applied to the beam steering of a metasurface, and control was demonstrated in real time. New applications are made possible by the low cost and ease of integration.


title: Three Essays on Macroeconomics with a Focus on Household Finance

abstract: This thesis includes three essays on Macroeconomics with a focus on household finance. The essays aim to contribute to a deeper understanding of how individuals' and households' consumption, saving, and investment decisions are affected by external factors such as an economic shock or a policy change, and the mechanisms behind their responses.


title: “Microstructure Analysis of Polymer amended Fluid Fine Tailings Using Fiji-ImageJ Image analysis software”

abstract: Optimizing the flocculation process is crucial for improving the long-term dewatering behaviour of oil sands tailings. The objective of this research is to assess the long-term dewatering behaviour of the polymer amended Fluid Fine Tailings (FFTs) from reliable key indicators at an early stage of the production process, specifically, using optical microscopy images. The experiments include processing optical microscope images using an image analysis software, "Fiji-Image J", to generate quantitative metrics of floc morphology. Particle size distributions derived from the Image J based analyses show replicability, when multiple images from the same sample are analyzed. Preliminary correlations between image metrics and consolidation characteristics show some explanatory power, though further advanced statistical analyses will be required to properly assess the predictive power of the image-derived information.


title: The Dark Side of Being Connected: Image-Based Sexual Exploitation, Dark Personality Traits, and Coercion Perceptions

abstract: Technology use has brought about the perpetration of both sexting coercion and image-based sexual abuse. This study examined the association between the Dark Tetrad, propensity to morally disengage, and the perpetration of sexting coercion and image-based sexual abuse. This study also examined how those variables influence how someone perceives online coercion, when relationship type and coercion tactic are altered. With 1467 university students (72% women), higher psychopathy, sadism, or narcissism scores was associated with perpetrating image-based sexual abuse. For sexting coercion, identifying as a man, and higher narcissism scores were associated with perpetrating sexting coercion. Examining the vignettes, being a woman, not having perpetrated sexting coercion, and being higher in moral disengagement propensity altered perceptions of coercion; and a main effect for coercion tactic was found. This study showed that the general aggression model appears to be a valid theory to explain image-based sexual abuse and sexting coercion perpetration.


title: Preserving Safety, Dignity and Autonomy Through Multi-Modal Interactions: An Exploration into a Preferred Future of Design for Accessible Dressing Technology and E-Textiles

abstract: Ready-to-wear clothing is often designed for individuals without disabilities, which can create dressing barriers and challenges for individuals with disabilities, especially those with motor coordination, cognitive challenges sensory and self-regulation issues. In two studies we explored the visions of occupational therapists for the future of dressing through smart clothing and dressing technology. Using co-design and design fiction online workshops, we were able to gather a rich data set that included interview data, virtual sticky notes, creative writing exercises and storyboards. We coded and used thematic and abductive analysis to explore the data and created design fictions to explore the future of dressing technology. Occupational therapists identified challenges that impact dressing tasks, and requirements for the design of technology situated in the near future that would support the autonomy of disabled people.


title: Visualizing Meaning : Managing Perception and Meaning in Visual Communication Design

abstract: Visual communication designers strive to create effective visual messages that are easily perceived and meaningful, but various forms of visual noise can compromise their designs. A set of visual design criteria and tools, aimed to increase design efficiency and effectiveness will be developed through a literature review of communication-related disciplines, including psychology, linguistics, semiotics, communications studies, information theory and statistics design. A sampling of these criteria and tools will then be applied to case studies of web- and print-based visual presentations to research their viability, and expert interviews will further inform and develop the criteria list. The final criteria and tools, developed from the studies, will be used to build a prototype of a corporate at a glance presentation for a government organization, to research the usability of the criteria set. The research aims to develop visual communication design theory based on fundamental, interdisciplinary concepts that could, through further research, offer visual communication designers improved science-based design and research tools.


title: The Dialectic of Logos and Eros: Plato’s Display of Rhetoric in the Phaedrus and the Symposium

abstract: This dissertation offers an interpretation of Plato's philosophical writing that relies on the discussion of speech that is displayed in the Phaedrus. As Socrates shows in this discussion of speech, the philosophical writer who wishes to teach the philosopher's art of thinking must write in a way that could facilitate the serious activity of philosophy or dialectic, that is, the examination of the powers and affects of things that are said to be beneficial or harmful to human beings. In both the Phaedrus and the Symposium, Plato displays various speeches of praise and blame about erōs or love to which Socrates must respond, hence inviting his audience to examine for themselves the natures of speech and love as complex things, both in terms of their powers and affects in relation to the human soul. In other words, rather than the indoctrination of some rigid metaphysical system, Plato sought to teach through his philosophical writing-dramatic works which can be identified as Plato's "display of rhetoric"-an arduous art of thinking that Socrates calls dialectic.