VictorJuiz/thesis huggingface dataset:
Reassembling Discipline: Bu ston Rin chen grub’s Collection of Incidents Involving Nuns from the Vinaya (ʼDul ba dge slong maʼi gleng ʼbum)

This dissertation explores consistency problems in sources for nuns in the Mūlasarvāstivāda Vinaya preserved in Tibetan, and one fourteenth-century exegete’s solutions to those problems. If one looks closely at the canonical recitation text of nuns’ rules, the Bhikṣuṇī-prātimokṣa-sūtra, alongside the ostensibly matching canonical explanatory text, the Bhikṣuṇī-vinaya-vibhaṅga, significant discrepancies of order and content appear in the minor rules, particularly in the pāyantikā section. In 1352, the Sa skya polymath Bu ston Rin chen grub (1290–1364) developed a digest of narratives about nuns, the ʼDul ba dge slong maʼi gleng ʼbum or Collection of Incidents Involving Nuns from the Vinaya, which remediated the discrepancies he saw in these sources. He took the recitation text to be authoritatively Mūlasarvāstivādin, rejected the explanatory text as belonging to another sect, and relied on the Indian exegete Guṇaprabha’s Vinayasūtra and its autocommentary (fifth–seventh century) as guides. He supplemented narratives from the Ārya-sarvāstivādi-mūla-bhikṣuṇī-prātimokṣa-sūtra-vṛtti, a source grouped as commentary, which he attributed to yet another sect. This dissertation argues that in the process of remediating the code’s inconsistencies, Bu ston created a new set of rules in certain sections, in some cases drawing on commentarial works to make sense of rules and narratives for which texts with the authority of buddhavacana—the status of buddha-speech, or canonicity—were readily available. In other words, the rules he compiled match no other extant list in full, including the list given in the canonical recitation text itself. In addition to this central claim about Bu ston’s use of sources, this dissertation demonstrates that Bu ston drew extensively on narrative supplements and past-life narratives (avadānas), to the extent of favoring narrative richness over brevity. A brief look at the writing of the thirteenth-/fourteenth-century monastic legal authority mTsho sna ba Shes rab bzang po also shows that Bu ston was not the first to give attention to discrepancies about the nuns’ rules. This dissertation underlines the lasting effects of Bu ston’s digesting practices on the circulation of vinaya narrative literature in Tibet, largely through its impact on the digest produced by Dalai Lama I dGe ’dun grub. Finally, this dissertation raises questions about what, if anything, Bu ston’s grappling with nuns’ rules tells us about the status of nuns in Tibet during his time, and what values his digest embodies in terms of norms for organizational consistency and information management.

Keywords: Buddhism
India
monastic law
nuns
Tibet
vinaya
Advisor: Clarke, Shayne
Goodman, Amanda K
The Evolution of C4 Photosynthesis in Blepharis (Acanthaceae): Multiple Transitions, Diverse Intermediate States, and Divergent Routes to a Convergent Phenotype

The evolution of life on Earth is characterized not just by the adaptation of living things to new and changing conditions but by the emergence of complexity. A central challenge to understanding the diversity of life on Earth is thus understanding how complex traits emerge. Convergent evolution provides a powerful tool for addressing the emergence of complexity because independent origins of a complex trait can serve as natural experimental replicates. As a de novo metabolic pathway with elaborate anatomical and regulatory requirements, the repeated emergence of C4 photosynthesis from C3 ancestors in land plants represents a richly convergent system for studying the evolution of complexity. Based on preliminary analyses of herbarium specimens, the genus Blepharis (Acanthaceae) has been hypothesized to represent a dynamic lineage in which to study C4 evolution. This dissertation aims to develop Blepharis as a model system for C4 evolution via physiological, biochemical, phylogenetic, anatomical, immunohistochemical, and transcriptomic analysis of a living collection of 28 Blepharis species. All known classes of C3-C4 intermediate phenotypes are shown to occur in Blepharis, including the proto-Kranz, C2, and C4-like character states. Critically, substantial C2-C4 intermediate diversity is revealed, including intraspecific variation in three related species. Common modifications in other C4 lineages, including higher vein density and larger bundle sheath cells, appear to represent pre-existing anatomical enabling conditions in Blepharis. Intermediate phenotypes largely follow a phylogenetic gradient from C3 to C4, supporting a stepwise model of C4 evolution. Five independent origins of the C4 cycle are identified, with one representing a novel, aspartate-dependent variation of the typical NADP-ME C4 pathway. Transcriptome analysis reveals differing underlying molecular mechanisms supporting the convergent C4 phenotype in independent C4 Blepharis lineages and identifies the co-function of the C2 and C4 carbon concentrating systems as an important consideration during late-stage C4 evolution. Together, these findings demonstrate the power of Blepharis to generate new insight into the evolution of C4 photosynthesis and how complexity arises in living systems.

Keywords: Blepharis
C3-C4 Intermediates
C4 Photosynthesis
Photosynthesis
Phylogenomics
Transcriptomics
Advisor: Sage, Rowan F
Sage, Tammy L
Characterization of Phagosome Resolution in Mammalian Phagocytes

Phagocytosis is the process by which particles are internalized and degraded by specialized, highly active cells in the organism, known as phagocytes. Billions of phagocytic events occur daily in the body, which serve to capture and digest apoptotic cells, microbial pathogens and unwanted particles within membrane-bound organelles called phagosomes. As such, phagocytic cells like macrophages, have an extraordinary phagocytic capacity, as they can internalize up to three times their own volume in particles. Yet for every phagosome formed, finite cellular resources, like the plasma membrane and endolysosomal organelles, are consumed. How can macrophages sustain their impressive phagocytic capacity without exhausting cellular resources? Maintenance of cellular appetite must be associated with the recycling of essential components from phagosomes after cargo degradation, where this recycling must occur during a newly defined stage in the life cycle of the phagosome, known as phagosome resolution. Unlike the rest of the maturation process, which has been studied extensively, very little is known about phagosome resolution and thus we sought to characterize this final stage. By monitoring the fate of phagosomes carrying degradable and non-degradable cargo and labelling phagosomal markers, we uncovered that macrophages resolve phagosomes through a continuous dismembering process resulting in the shedding of myriads of lysosome-like vesicles containing degraded cargo, which we called phagosome-derived vesicles (PDVs). These results challenged the preconceived notion that intact phagolysosomes within mammalian phagocytes are primarily resolved through the process of cell secretion called exocytosis, which is the known fate of phagosomes in unicellular organisms. Further investigation into the mechanism behind phagosomal fragmentation revealed that this process is dependent on cargo degradation, clathrin and the actin and microtubule cytoskeletons. Additionally, inhibition of this stage of phagocytosis prevented the reformation of the pool of lysosomes and the maturation of subsequent phagosomes, as components were unable to be retrieved from the pre-existing phagosomes to further the maturation of subsequent compartments. Thus, we propose that phagosome resolution recycles cellular resources for the continuous generation of new phagosomes and prevention of this phase impairs the immune and housekeeping functions of phagocytes.

Keywords: Exocytosis
Fragmentation
Macrophages
Phagosome
Phagosome resolution
Phagosome-derived vesicles (PDVs)
Advisor: Terebiznik, Mauricio R.
Relatively Supercuspidal Representations of the Symplectic p-adic Groups

In this thesis, we construct in a concrete manner a family of non-supercuspidal, relatively supercuspidal representations of symplectic p-adic groups, based on the work of Murnaghan. We cover the symmetric pairs (Sp(4n,F), Sp(2n,E)), (Sp(2n,E), Sp(2n,F)) and (Sp(2n,F), Sp(2k,F) x Sp(2(n-k),F)) where F is a p-adic field of odd residual characteristic, and E is a quadratic field extension of F. We also look at the symmetric pairs (Sp(2n,F), GL(n,F)) and (Sp(2n,F), U(n,E/F,ε)) for ε an invertible Hermitian matrix over E/F. For these additional pairs, the above construction doesn't result in any non-supercuspidal, relatively supercuspidal representations (despite these pairs admitting distinguished supercuspidals). We end with an in-depth look at the case of Sp(2,F) = SL(2,F). We show that in this low-rank example, for all of the above pairs, all irreducible relatively supercuspidal representations of SL2(F) are either supercuspidal or obtained from our construction. In particular, all irreducible H-relatively supercuspidal representations of SL(2,F), for H either GL(1,F) or U(1,E/F,ε), are supercuspidal.

Keywords: Involutions
Reductive p-adic groups
Representation theory
Advisor: Murnaghan, Fiona
Data-Driven Models for Robust Egomotion Estimation

In many modern autonomy applications, robots are required to operate safely and reliably within complex environments, alongside other dynamic agents such as humans. To meet these requirements, localization algorithms for robots and humans must be developed that can maintain accurate pose estimates, despite being subjected to a range of adverse operating conditions. Further, the development of self-localization algorithms that enable mobile agents to maintain an estimate of their own pose is particularly important for improved autonomy. At the heart of self-localization is egomotion estimation, which is the process of determining the motion of a mobile agent over time using a stream of body-mounted sensor measurements. Body-mounted sensors such as cameras and inertial measurement units are self-contained, lightweight, and inexpensive, making them ideal candidates for self-localization. Traditional approaches to egomotion estimation are based on handcrafted models that achieve a high degree of accuracy while operating under a range of nominal conditions, but are prone to failure when the assumptions no longer hold. In this dissertation, we investigate how data-driven, or learned, models can be leveraged within the egomotion estimation pipeline to improve upon existing classical approaches. In particular, we develop a number of hybrid and end-to-end systems for inertial and visual egomotion estimation. The hybrid systems replace brittle components of classical egomotion estimators with data-driven models, while the end-to-end systems solely use neural networks that are trained to directly map from sensor data to egomotion predictions. We employ these data-driven systems for self-localization in pedestrian navigation, urban driving, and unmanned aerial vehicle applications. In these domains, we benchmark our systems on several real-world datasets, including a pedestrian navigation dataset that we collected at the University of Toronto. Our experiments demonstrate that, in challenging environments where classical estimation frameworks fail, data-driven systems are viable candidates for maintaining self-localization accuracy.

Advisor: Kelly, Jonathan S.
On Bilevel Optimization without Full Unrolls: Methods and Applications

Bilevel optimization (BLO) problems are nested optimization problems where an outer objective must be minimized subject to the optimality of an inner objective. This nested structure poses several challenges, including the cost of running full unrolls of the inner problem for each outer parameter update. We discuss several approaches which allow for efficient bilevel optimization, that do not require full inner unrolls. 1. Challenge: Inner optimization is expensive and needs to be re-run for each outer parameter update. We introduce Self-Tuning Networks (STNs), an approach that learns a parametric approximation to the best-response function online, amortizing the inner loop optimization. STNs address the two main challenges to fitting a best-response approximation: 1) STNs fit the approximation locally around the current outer parameters, and alternate between updating the outer parameters and updating the best-response approximation, and 2) STNs use a structured hypernetwork to represent the best-response, that scales to large neural networks. 2. Challenge: Long unrolls of the inner optimization can lead to chaotic meta-loss landscapes; short unrolls can lead to truncation bias. To address both of these issues, we introduce Persistent Evolution Strategies (PES), an approach for computing unbiased gradient estimates of parameters that govern a dynamical system, using only partial unrolls of the system. PES estimates the gradient of a Gaussian-smoothed objective, allowing for optimization over chaotic landscapes. 3. Challenge: Most research in BLO assumes that the solutions to the inner and outer problems are unique, but in practice typically either the inner or outer problems are underspecified. In this case, there are many ways to choose among equivalent optima, potentially leading to different results. In this part, we investigate the implicit bias of commonly-used algorithms in overparameterized bilevel optimization. 4. Finally, we introduce Amortized Proximal Optimization (APO), a framework for online meta-optimization of a parametric update rule which governs optimization. APO is based on a 1-step lookahead meta-objective. Under appropriate assumptions, APO can recover existing optimization algorithms such as natural gradient descent. We present two use-cases of APO: 1) tuning a structured preconditioning matrix; and 2) tuning the global learning rate of several base optimizers.

Keywords: bilevel optimization
hyperparameter optimization
machine learning
Advisor: Grosse, Roger B
Electric Vehicle Drivetrain with Integrated Nonisolated Charging and Auxiliary Power Module

As electric vehicles set out to compete with their internal combustion engine counterparts, cost and range anxiety are the two main factors limiting the speed of adoption.Even as transportation electrification becomes the norm in the decades to come, these aspects are expected to remain the significant drivers of consumer decision-making. Electric vehicles require several onboard power converters, contributing considerably to production cost and vehicle weight, the latter impacting energy consumption and, ultimately, range. Among the significant power electronic systems are the input three-phase and single-phase compatible onboard charger, responsible for charging the traction battery from an ac supply, and an auxiliary power module, responsible for converting power from the traction battery to the auxiliary low-voltage battery for powering subsystems, such as headlights and onboard computing systems. This thesis introduces a topology that integrates these three power conversion functionalities to the dual inverter drivetrain with no additional active semiconductors and minimal additional passive circuitry. Namely, three-phase onboard charging, single-phase onboard charging with optional active power decoupling, and traction-to-auxiliary battery power conversion are implemented solely with the drivetrain circuitry. Implementing this diverse set of functionalities reduces the need for discrete onboard converters, materially improving vehicle weight and production cost. To enable the aforementioned integrated power conversion, several theoretical contributions are included in this work. The mathematical model of the dual inverter with a split-phase open-winding machine is developed, explicitly describing all available degrees of freedom in the machine. A symmetrical design method for power converters eliminates the common-mode currents for nonisolated systems, enabling the design of standard-compliant onboard chargers. The power phasor and power space-vector concepts are introduced and leveraged to design an active power decoupling control for single-phase-to-dc power conversion applications. Lastly, the switching frequency component of the common-mode voltage between two dc links is controlled using carrier phase-shift between the inverters connected to said dc links.

Keywords: Active Power Decoupling
Auxiliary Power Module
Electric Vehicle
Machine Drives
Modeling and Control
Transformerless
Advisor: Lehn, Peter W.
Test Validation and Complex, Dynamic Systems: The Case of the Pedagogical Content Knowledge for Supporting English Learners Test (PeCKSELT)

Designing tests and rubrics, using test scores, and validating tests are all human-led activities that do not occur in isolation. Rather, these activities (and those performing them) constantly interact with internal and external elements, causing them to grow and change in sometimes nonlinear ways. These are the same characteristics of complex, dynamic systems as conceptualized in Complexity Theory. While Complexity Theory has been used in various disciplines, such as education, urban studies, and applied linguistics, it has yet to be fully integrated into the test validation literature. In this study, I address this gap, first by presenting a novel framework that infuses Interpretation Use Arguments (a traditional approach to validation) with aspects of Complexity Theory. I then apply this framework to uncover validity evidence for the Pedagogical Content Knowledge for Supporting English Learners Test (PeCKSELT), a measurement of Teacher Candidates’ understanding of how to support English Learners (ELs) in their K–12 classrooms. Within this complex validation system, I sought evidence to support two key claims (i.e. warrants): 1) PeCKSELT test performance elicits the relevant PCK required for teachers to successfully support their EL students in K–12 Ontario Classrooms; and 2) PeCKSELT scores reflect the target abilities and skills associated with PeCKSEL. Evidence to support these claims comes from the findings of two analyses I conducted. One of these was a thematic analysis of data that emerged from phenomenological interviews of PeCKSELT test developers. The other is from Latent Profile Analysis of the PeCKSELT scores of 307 Teacher Candidates who took the test in the Fall of 2018. Throughout this study, I also examine overarching theoretical concerns regarding the possibilities and benefits of applying Complexity Theory to test validation procedures. Moreover, as test takers, developers, test validation and the construct being measured are all complex, dynamic systems, I also explored the ways in which testing can still generate information that is stable enough to be useful.

Keywords: complexity theory
latent profile analysis
supporting multilingual learners
teacher education
test validity
thematic analysis
Advisor: Bale, Jeff
Morality of Matchmaking: When is discrimination perceived as more or less immoral?

Deciding with whom to interact on the basis of potential partners’ social group membership is, in general, condemned and thus avoided; however, such prejudicial partner selection continues to be prevalent in dating. The present research examined whether people would use social group membership to guide their choice of romantic partners. Results show that people spontaneously nominated social group memberships as their relationship deal-breakers and must-haves (Chapter 2) and were indeed more likely to shortlist and choose dating partners based on social group membership compared to work-related (e.g., business partners; Chapter 4) and other close relationship (e.g., friends; Chapter 5) partners. Guided by the Justification-Suppression Model of Prejudice (Crandall & Eshleman, 2003), the present research then explored why prejudicial partner selection is more prevalent in dating than in other contexts. I examined two norms in dating that may be conducive to prejudicial partner selection: norms around prejudicial dating decisions (Chapter 3) and partner selection based on mate value (Chapter 4). I found evidence consistent with the first norm; prejudice was perceived as socially acceptable when used to choose dating partners. However, I failed to find evidence for the second norm; prejudicial partner selection was not more or less likely among those who perceived themselves as desirable vs. undesirable romantic partners. I also explored two factors that may serve as a justification for prejudicial partner selection: the perceived relevance of social group membership to diagnosing partner quality (Chapter 4) and the perceived malleability of attraction (Chapter 5). Perceived diagnosticity indeed served as a justification such that prejudicial partner selection was more likely when social group membership was perceived as diagnostic vs. undiagnostic to partner quality; however, it did so across all contexts and its justification effect was weaker in dating than in other contexts. Malleability beliefs about attraction also served as a justification for discrimination; people were more likely to discriminate when they believed attraction cannot (vs. can) be changed. The justification effect of malleability beliefs was not unique to dating but rather was comparable in strength across close relationships. Overall, the present research provides strong evidence that prejudicial partner selection remains prevalent in the context of dating and highlights the importance of social norms in perpetuating prejudicial partner selection across contexts.

Keywords: close relationships
dating
intergroup relations
prejudice and discrimination
social norms
Advisor: Lockwood, Penelope
Page-Gould, Elizabeth