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- Resource Type:
- Thesis
- Creator:
- FitzGerald, Margaret Elaine
- 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.
- Thesis Degree:
- Doctor of Philosophy (Ph.D.)
- Thesis Degree Discipline:
- Political Science
- Date Created:
- 2020
- Resource Type:
- Thesis
- Creator:
- Delaney, Hannah Stowe
- 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.
- Thesis Degree:
- Master of Arts (M.A.)
- Thesis Degree Discipline:
- International Affairs
- Date Created:
- 2022
- Resource Type:
- Thesis
- Creator:
- Abadeer, Macarious Philip Aziz
- 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.
- Thesis Degree:
- Master of Computer Science (M.C.S.)
- Thesis Degree Discipline:
- Computer Science
- Date Created:
- 2022
- Resource Type:
- Thesis
- Creator:
- Perez, Nicolas
- 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.
- Thesis Degree:
- Master of Computer Science (M.C.S.)
- Thesis Degree Discipline:
- Computer Science
- Date Created:
- 2022
- Resource Type:
- Thesis
- Creator:
- Singh, Gurjit
- 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.
- Thesis Degree:
- Doctor of Philosophy (Ph.D.)
- Thesis Degree Discipline:
- Biology
- Date Created:
- 2022
- Resource Type:
- Thesis
- Creator:
- Farrag, Nadia
- 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).
- Thesis Degree:
- Doctor of Philosophy (Ph.D.)
- Thesis Degree Discipline:
- Engineering, Biomedical
- Date Created:
- 2022
- Resource Type:
- Thesis
- Creator:
- Mahmoud, Ahmed Gamal Khodary
- 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.
- Thesis Degree:
- Doctor of Philosophy (Ph.D.)
- Thesis Degree Discipline:
- Engineering, Electrical and Computer
- Date Created:
- 2022
338. Geographic Distribution of Trends and Cycles in Eastern North American Instrumental Climate Data
- Resource Type:
- Thesis
- Creator:
- Walsh, Carling
- 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.
- Thesis Degree:
- Doctor of Philosophy (Ph.D.)
- Thesis Degree Discipline:
- Earth Sciences
- Date Created:
- 2022
- Resource Type:
- Thesis
- Creator:
- Ward, Nicholas Ryan
- 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.
- Thesis Degree:
- Master of Arts (M.A.)
- Thesis Degree Discipline:
- Communication
- Date Created:
- 2022
- Resource Type:
- Thesis
- Creator:
- Yoo, Hyung-Suk
- 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.
- Thesis Degree:
- Doctor of Philosophy (Ph.D.)
- Thesis Degree Discipline:
- Neuroscience
- Date Created:
- 2022