VictorJuiz/thesis huggingface dataset:
Tracing Atmospheric Sources of Mercury through Passive Air Sampling and Isotope Characterization

Gaseous elemental mercury (GEM) is the dominant form of mercury (Hg) in the atmosphere and is the main species responsible for Hg being globally distributed far from point sources. Tracing Hg sources in the atmosphere remains challenging, but a potential new tool to aid in this is the measurement of stable Hg isotope ratios in atmospheric samples. Mercury isotopes undergo both mass-dependent fractionation (MDF) and mass-independent fractionation (MIF) making them useful for identifying and quantifying sources and transformations of Hg. Current collection methods for isotope characterization of atmospheric GEM rely on power and instrumentation requiring technical expertise, making sampling on large spatial scales and in remote locations difficult. Here, we assess the ability of a passive air sampler (PAS), which samples GEM, to collect and preserve Hg for isotope analysis. Based on both field and laboratory experiments, this thesis demonstrates that no MIF occurs during sampling of GEM by the PAS and that there is consistent MDF offset of ≈-1.2 ‰ in δ202Hg. The PAS was then used in two reconnaissance studies on the spatial distribution of GEM concentrations and isotopes across large regions (Ontario, Canada and Madre de Dios, Peru). In both Ontario and Peru, the Hg isotopic composition of GEM collected with the PAS allowed regional and local sources to be identified and traced. In Ontario, southern regions with greater local urban/industrial emission sources and/or trans-regional air masses containing industrial sources had GEM that was isotopically distinct from northern regions, which have fewer emission point sources. In Madre de Dios, artisanal and small-scale gold mining (ASGM) activity is a main Hg source to the region and is isotopically distinct, allowing the contribution of ASGM derived GEM to be estimated. In addition to source tracing, Hg isotopes in GEM were also affected by vegetation uptake of GEM in both Ontario and Peru, which is a major removal process of GEM from the atmosphere and a major source of Hg to terrestrial ecosystems and soils. In Peru, isotope compositions in foliage and soils in Amazonian forests near mining indicated uptake of ASGM-GEM. These results demonstrate that Hg isotopes can be used to improve our understanding of sources to the atmosphere and soils (local/regional/global) and also assess major removal processes from the atmosphere.

Advisor: Bergquist, Bridget A
Interracial Intimacies: Navigating Race and Culture in Heterosexual Racialized-white Relationships in Toronto

The number of mixed-race couples in Canada, especially in metropolitan cities such as Toronto, is on a steadfast rise, yet there is limited culturally relevant research and literature on interracial unions. This study was conducted in response to the critical need for Canadian-specific research on this demographic, since there is an over-reliance on antiquated, problem-focused and United States-based research to inform the field of counselling and psychotherapy in Canada. The present study aimed to address this paucity by asking the question: what are the lived experiences of heterosexual, Racialized-White mixed-race couples in Toronto with regards to issues of race and culture? A constructivist grounded theory methodology explored the lived experiences of 12 heterosexual Racialized-White couples in Toronto and the Greater Toronto Area (GTA). Four key themes emerged from the findings – lived experiences of race/culture prior to mixed-race relationships; lived experiences of race/culture in mixed-race relationships; critical reflections on lived experiences: negotiating differences, racism and privilege, and being in ‘the middle’ of two races and cultures; and lived experiences beyond race/culture. The themes illustrated the multifaceted, vastly diverse and dynamic experiences and processes evident in these unions. This research further postulated that the experiences of interracial couples cannot be fully ascertained without a critical consideration within the context of Canadian colonialism, White supremacy, heteropatriarchy and endogamous discourse. A mid-level theory arose from this study, revealing the multilayered influences on and experiences of heterosexual interracial couples. Implications for education, research and counselling and psychotherapy are addressed, including contributions to intercultural counselling competencies and decolonial pedagogy for counselling psychology programs. Key Words and Phrases: Mixed-Race Relationships, Racialized-White, Race, Culture, Canada

Keywords: Culture
Exogamy
Interracial Relationships
Mixed-Race Relationships
Race
Advisor: Moodley, Roy
Interpretable Machine Learning: Explaining Models, Datasets and Expert Behaviors

As machine learning models become increasingly adopted in high-stakes real-world applications, we require the models not just to be accurate but also fair, robust, and causal. These objectives necessitate the interpretability that makes users understand both the model and its training data to make sure the objectives are met. In this thesis, I present four of my works that interpret models, datasets, and expert behaviors. First, I focus on interpreting any black-box models decisions by counterfactual reasoning; we find it finds more relevant and important features than the baselines. Then I describe the remaining three works on Generalized Additive Models (GAMs) - an inherently interpretable model class. I first compare different training methods of GAMs to understand which GAM explains better. Then I develop a deep-learning version of GAM, Node-GAM, that scales better than the traditional GAMs and still remains interpretable compared to other deep learning methods. Finally, I apply the Node-GAM to extract clinicians’ treatment goals by inverse reinforcement learning in an ICU dataset. I show our model recovers several clinically meaningful guidelines while the previously-used linear model often contradicts them. Finally, I conclude with several future directions of interpretable machine learning.

Advisor: Goldenberg, Anna
Teacher, Talk, and Technology: Exploring Teaching and Learning in Grade 4 Mathematics

This doctoral dissertation sought to explore teachers’ experiences and challenges as they learn to use technology to support their students’ mathematics learning. The purpose of this study was to identify good, efficient, innovative teaching practices and strategies when technology is implemented and integrated in Grade 4 mathematics. The data for these cases were collected through the observation and interviews with two Grade 4 teachers. The diverse levels and quality of the communication, collaboration, cooperation, cross-curricular connections, and curriculum development emerged during their mathematics sessions with their students. The current research study revolves around these two Grade 4 teachers’ pedagogical practices, and conceptions of technology adoption and integration in their mathematics teaching practice, while evaluating how the technology was implemented and integrated into mathematics teaching and learning activities to enhance their students’ mathematics conceptual understanding. The qualitative study also explores the teachers’ experiences and perceptions concerning technology as a tool that mediates learning and discourse in their Mathematics instructional sessions. Teachers, their students, and their peers are continuously negotiating and navigating the pedagogical spaces that promote and enhance mathematics learning and interactions across cross curricular subject content, communication, and collaboration. The following are key factors, based on the findings of this study, that can contribute to the effective implementation of technology to enhance mathematical discourse: A willingness of teachers to improve their practice in the area of technology integration, the technology-related learning tasks need to be developmentally appropriate, and teachers need to be able to successfully identify, acknowledge, and respect how each student learns with technology.

Keywords: Cross-curricular connections
Grade 4 Mathematics pedagogy
Roles for technology
Sociocultural theory
STEAM/SS
Technology integration
Advisor: McDougall, Douglas
Episodic Control: The Role of Memory in Decision Making

Reinforcement learning (RL) is an area of computer science concerned with trial-and-error learning of optimal behaviour. As such, RL can offer a normative framework for understanding learning in animals. However, some aspects of animal behaviour are not well accounted for by traditional RL solution methods. In particular, biological brains are able to learn and relearn quickly, flexibly using memory for specific events (i.e. episodic memory, EM) to solve tasks with minimal experience. Incorporating models of EM in RL can enable rapid learning and facilitate solving long-distance credit assignment problems. These models typically treat EM as a pure record-keeping system for sensorimotor data, but psychology and neuroscience understand EM to have broader capabilities. In the brain, EM maintains conjunctive representations of spatial, temporal, and sensorimotor elements of experience. Moreover, EM is not an ever-expanding repository of experienced information. Rather, many processes exist to promote both active and passive forgetting, and research suggests this is beneficial for learning. Additionally, experiential information is used by multiple memory systems. Animals may initially rely on memories of individual events to guide behaviour, but experience with repeated stimulus-outcome associations also informs habitual memory systems. Thus, with training, behaviour may come to rely more on learned associations rather than memory for any specific experience. In this work I present an episodic control system for RL navigation tasks which incorporates some of these features of biological EM. I compare this episodic control system against the learning profile of a traditional RL agent and show that episodic control can make use of minimal data to leverage successful behavioural policies in a few-shot manner. I show that episodic control using representations of events which contain relational information offer greater performance advantages than unstructured sensory data, especially under conditions where agents experience moderate forgetting. Finally, I explore how the behaviour of agents using episodic control may be used to provide off-policy training data for network-based model-free RL agents, and how this may ameliorate the data-inefficiency inherent to such systems.

Keywords: Episodic Memory
Forgetting
Neural Networks
Reinforcement Learning
Advisor: Richards, Blake A
Parsing Through Paradox: Transdisciplinary Constructions of Mexicanidad in the Works of Martín Luis Guzmán

This dissertation delves into the paradoxical nature of the works, the persona, and the reception of one of the most renowned Mexican writers of the 20th century: Martín Luis Guzmán. In my project, I view the tensions between the legacy of Guzmán’s writings and his personal character, as well as the subsequent receptions of both the man and his works, as ones accessible through the intertwined hermeneutical realms of the ideological and the aesthetic. Employing Basarab Nicolescu’s theory of transdisciplinarity to navigate the relationship between ideo-aesthetics, my aim is to explore the links between the atemporal artistry of Guzmán’s works and the particularities of the socio-political conditions in which these were produced. Specifically, I focus on the texts written during the author’s two exilic periods (1915-1920 and 1924-1936), beginning with La querella de México (1915) and ending with El águila y la serpiente (1928) and La sombra del caudillo (1929). Not only are these works foundational to Guzmán’s own writing career, but they also tackle the lingering preoccupation that defined the Mexican (post-)revolutionary period: what is Mexicanidad and what constitutes lo mexicano? Through a transdisciplinary reading, I demonstrate how Guzmán’s use of distinct literary elements such as symbolism, genre, narration, and themes acquire an ideo-aesthetic function that locates questions of national character within identifiable ideological milieus while simultaneously dis-locating them to hermeneutically ambiguous aesthetic spaces.

Advisor: Antebi, Susan
Explorations on Beyond Endoscopy

In this thesis we provide a description of the first paper on Beyond Endoscopy by Altug and explain how to generalize to totally real fields, based on a joint work of the author with Melissa Emory, Debanjana Kundu and Tian An Wong, and is a work in preparation. This part is mostly expository, and we refer the reader to the relevant paper. Furthermore, we prove a conjecture of Arthur. In his original paper on Beyond Endoscopy, Langlands provides a formula for certain product of orbital integrals in GL(2, Q), subsequently used by Altug to manipulate the regular elliptic part of the trace formula with the goal of isolating the contribution of the trivial representation. Arthur predicts this formula should coincide with a product of polynomials associated to zeta functions of orders constructed by Zhiwei Yun. We prove this is the case by finding the explicit polynomials and recovering the original formula from them. We also explain how some aspects of the strategy used can be interpreted as problems of independent interest and importance of their own. En esta tesis damos una descripción del primer articulo sobre Más Alla de la Endoscopía por Altug y explicamos como generalizarlo a campos totalmente reales, basados en un trabajo conjunto con Melissa Emory, Debanjana Kundu y Tian An Wong, y él cuál sigue en estado de preparación. Esta parte es mayormente una exposición y referimos al lector al artículo relevante. Además, demostramos una conjetura de Arthur. En su artículo original sobre Más Allá de la Endoscopía, Langlands da una fórmula para cierto productos de integrales de órbita en GL(2, Q), subsecuentemente utilizadas por Altug para manipular la parte regular eliptica de la formula de traza con el objectivo de aislar la contribución de la representación trivial. Arthur predice que esta formula coincide con un producto de polinomios asociados a funciones zeta de órdenes construidos por Zhiwei Yun. Demostramos que esto es cierto mediante hallar los polinomios explicitos y recuperamos la formula original a partir de ellos. Más aún, también explicamos como algunos aspectos de esta estrategia pueden ser interpretados como problemas de interés e importancia independiente.

Keywords: Beyond Endoscopy
Langlands
Orbital Integral
Orders
Zeta Functions
Advisor: Arthur, James
A Context Evaluation of the OISE Psychology Clinic Adult Psychotherapy Service

Program evaluation is considered an important activity for psychology training clinics to conduct on an ongoing basis (American Psychological Association [APA] Education and Training Board, 1967; Stevenson & Norcross, 1987). Program evaluation can provide psychology training clinics with valuable information about the demographics of their stakeholders, the needs of those stakeholders, clinic activities and operations, and the effectiveness of those activities and operations as they relate to clinic goals (e.g., training and service delivery). To date there has not been an attempt to internally evaluate the OISE Psychology Clinic Adult Psychotherapy Service, which oversees the clinic’s training of graduate students in the treatment of adult clients. As a result, the OISE Psychology Clinic Adult Psychotherapy Service could benefit from greater program understanding and the addition of evaluation as an ongoing clinic activity. A context evaluation approach (Fitzpatrick, 2012; Greene, 2005; Stufflebeam, 1968) is used to provide programmatic knowledge and boost evaluation activity. This report uses the first stage of Stufflebeam’s (1968) Context, Input, Process, Product evaluation model to provide the service with detailed information about its stakeholders, activities, and various contextual environments (e.g., its physical environment, social and interpersonal environment, technological environment, etc.), as well the strengths and challenges of those elements. This information is intended to provide the service with greater program knowledge, and, in so doing, strengthen the service. Additionally, the use of the Context, Input, Process, Product model, which can be be iteratively implemented, is intended to provide the Adult Psychotherapy Service with the means for continuing the evaluation process and integrating evaluation into the service’s ongoing activities.

Advisor: Goldstein, Abby
Investigation of the Serological Changes that Discriminate Asymptomatic Antinuclear Antibody Positive Individuals from Systemic Autoimmune Rheumatic Disease Patients

The Antinuclear antibody (ANA) associated Systemic Autoimmune Rheumatic Diseases (SARDs) are chronic rheumatic disorders associated with high morbidity. Many patients with these diseases have irreversible tissue damage at disease presentation. Current therapies aim to control symptoms and prevent further damage by lessening the inflammatory immune response through broad and often aggressive immunosuppression, which leaves patients vulnerable to numerous side effects. Although ANAs are a serological hallmark for the ANA-associated SARD, they are also seen in healthy individuals, most of whom will not progress to disease. This not only precludes their use as biomarkers of progression but also indicates that their presence alone is insufficient to induce tissue damage and symptoms. Elucidating the serological differences between ANA-associated SARD patients and asymptomatic ANA+ individuals and the underlying immune mechanism(s) that led to these differences will permit identifying individuals at increased risk of progression and enable the development of better therapeutic targets. Here, we show that although the type, number, and levels of specific auto-antibodies (auto-Abs) remained stable over a 2-year follow-up period in the subset of asymptomatic ANA+ individuals that developed new SARD symptoms, these individuals have elevated levels of anti-Ro52 auto-Ab as compared to those that did not progress. We also demonstrated that SARD patients have very high levels of IgG auto-Abs as compared to ANA+ individuals that lack a SARD diagnosis, that are not detected by current screening techniques, arguing for the introduction of assays with a better dynamic range and discriminatory capacity. Additionally, we found that the IgG of SARD patients has a reduced sialic acid content, as compared to healthy controls and asymptomatic ANA+ individuals, which correlated with an increased ability to induce a pro-inflammatory response by monocyte-derived dendritic cells, serum levels of TNF- and the proportion of circulating T follicular helper 17 cells. These findings enhance our understanding of the underlying immunologic dysregulations that promote the transition from asymptomatic autoimmunity to disease and suggest that therapies that target these pathways may be useful to prevent progression to SARD.

Keywords: Microarray
Microparticles
Sialic acid
Systemic autoimmune rheumatic diseases
Systemic lupus erythematosus
Advisor: Wither, Joan E
Dissonance Reimagined: Tone Clusters in Leo Ornstein’s Early Piano Music

It can be argued that the contributions of Russian-American composer Leo Ornstein (1895-2002) to the American musical avant-garde movement have not yet been sufficiently acknowledged. His piano works from the 1910s prominently feature heavily-dissonant tone clusters, used in a great variety of musical contexts. Known most commonly for creating massive, aggressive sounds, they were integrated by Ornstein into music of a much more colouristic compositional idiom.The first chapter of this dissertation concerns the history of tone clusters on the modern piano and provides historical context for Ornstein’s own application of them. Little scholarship exists on the specifics of Ornstein’s usage of the technique. This dissertation documents the many uses of clusters and other extreme dissonances in his music from 1913-1918, arguably the most experimental period of his compositional career. Seven pieces are discussed in detail in the second chapter: Danse Sauvage, S054 (1913)Dwarf Suite, S052 (1913) Impressions of Notre Dame, S056 (1914) Impressions of the Thames, S053 (1914) The Cathedral, S073 (1915) Poems of 1917, S061a (1917) À La Chinoise, S060 (1918) The tone clusters contained within are analyzed for their harmonic content, registral and formal placement, and the manner in which they are played, among other considerations. More general assessments of these pieces, concerning other elements of dissonance not specifically falling into the category of clusters, are also offered. The third and final chapter begins with a discussion of how Ornstein integrates elements of more minor dissonance, and less frequent clusters, into music of a more traditional idiom. His clusters are then compared to those written by George Antheil and Henry Cowell, two other composers of the period most often associated with the technique, a comparison which reveals several differences in approach.

Keywords: avant-garde
dissonance
Leo Ornstein
piano
tone cluster
Advisor: McClelland, Ryan
Identifying SLAP2-TRIM21 as a Novel Endogenous Recycling Complex of EGFR in Lung Cancer

The epidermal growth factor receptor (EGFR) is the most-studied member of the receptor tyrosine kinase (RTK) family of proteins, particularly as a driver oncogene in non-small cell lung cancer (NSCLC). Targeted therapeutic approaches to inhibiting EGFR activity with receptor tyrosine kinase inhibitors (RTKi) have proven limited, considering lung cancers can acquire resistance to these molecules by developing EGFR mutations or overexpressing other RTKs. To produce more robust molecular therapies, more critical drug targets must be elucidated within cancers. One approach to doing so is to discover novel mechanisms that regulate EGFR in lung cancer. I accomplished this by using novel technologies for detecting protein-protein interactions, the Mammalian Membrane Two Hybrid (MaMTH) and Split Intein Mediated Protein Ligation (SIMPL) assays, to detect novel Src-homology 2 (SH2) domain containing proteins which interact with EGFR in an activation dependent manner. This yielded SLAP2 as a novel interactor of EGFR, which I functionally characterized in H460 NSCLC cells. Using a sleeping beauty transposon system, I overexpressed FLAG-tagged wildtype and mutant isoforms of SLAP2, which demonstrated that SLAP2 upregulates EGFR and maintains expression after ligand stimulation. Then using affinity purification coupled to mass spectrometry, we identified TRIM21 as an interactor of SLAP2 that maintains EGFR expression post activation. Finally, I used CRISPR/Cas9 to deplete endogenous SLAP2 levels in H460 cells showing downregulation of EGFR expression post activation, and subsequent recovery of EGFR upregulation with transient overexpression of SLAP2, validating the endogenous function of this interaction in non-small cell lung cancer.

Keywords: cell signaling
EGFR
genome editing
lung cancer
protein interactions
systems biology
Advisor: Stagljar, Igor