VictorJuiz/thesis huggingface dataset:
One-class Collaborative Filtering with Latent Embeddings: Improvements and Interactive Extensions
Keywords: Collaborative Filtering
Critiquing-based Conversation
Deep Learning
Machine Learning
Recommender System
Variational Autoencoder

Systems that recommend personalized lists of items to users are increasingly prevalent in our online experience and critical for the commercial success of online services such as Amazon, Netflix, and Youtube. An important subclass of recommendation is the one-class setting, where only positive feedback is directly observed (e.g., likes, purchases, clicks). While one-class recommendation tasks are challenging due to the lack of explicit negative feedback, collaborative filtering (CF) methods that leverage the collective preferences of a large user population have proved to be effective, especially CF methods that rely on latent embeddings. This thesis aims to extend the state-of-the-art one-class collaborative filtering (OC-CF) with latent embeddings and focuses on three unresolved problems in this research area: (1) existing methods for learning latent embeddings tend to be popularity biased and thus can perform poorly for items in the long tail; (2) in cases where user interests are diverse, existing latent embedding methods tend to be over-confident and fail to model a user’s full preference spectrum; (3) as recommender systems become more interactive, little work has addressed how to co-embed rich (e.g., language-based) user feedback in the same latent space as user preferences. To address (1), we leverage a method known as noise-contrastive estimation (NCE) to learn de-popularized embeddings in both linear and deep learning OC-CF methods. To address (2), we extend methods for Variational Auto-encoders (VAEs) for stochastic embeddings that avoid over-confidence. To address (3), we provide a novel variational extension of neural collaborative filtering that allows co-embedding of language-based feedback to support an interactive recommendation setting. We empirically validate all contributions in comparison to a variety of state-of-the-art OC-CF methods and demonstrate the advantages of our previously outlined contributions. In summary, the thesis makes several significant novel contributions to both improve and extend OC-CF methods based on latent embeddings.
The Molecular Associations of Host Characteristics in Cancer Genomics
Keywords: Age
Ancestry
Biomarkers
Cancer
Health Disparities
Sex

Epidemiological studies have identified myriad differences in cancer burden between people of different sexes, ancestries, and ages. Male individuals are more likely to develop most cancers and die of their disease. While overall cancer incidence is comparable between individuals of African vs. European ancestry, cancer mortality is higher in those of African ancestry. Increasing age is a well-known cancer risk factor, yet there are exceptions such as in pediatric cancers. These are only a few examples of epidemiological differences associated with fundamental characteristics of the cancer host. Since cancer is driven by genomic alterations, it is likely that epidemiological differences can be explained by differences in the cancer genomic landscape. I assessed this by performing a comprehensive pan-cancer analysis of sex-, ancestry-, and age-associated differences in 12,774 tumour genomes across 33 tumour-types using data from The Cancer Genome Atlas and the International Cancer Genome Consortium. I investigated genome-wide and localized phenomena including measures of mutation density and tumour evolution, mutational signatures, and the frequency of single nucleotide variants and copy number aberrations. I used multivariable methods to identify sex-, ancestry-, and age-associations that persisted even after adjusting for confounding factors such as smoking history and tumour stage. Sex-, ancestry-, and age-associations span the spectrum of somatic genomic features across all except three tumour-types studied. While some genomic associations were detected in pan-cancer analysis, many others were tumour-type specific. Finally, I leveraged sex-, ancestry- and age-biased genomic features to identify functional associations. Using transcriptomic data, I found that many sex-, ancestry-, or age -biased mutations were themselves associated with changes in mRNA abundance. Some mRNA abundance changes were also dependent on the context of sex, age, or ancestry. Similarly, I identified biased genomic features that were associated with survival. Some genomic features were only associated with survival in one sex or age group, suggesting host characteristics influence the prognostic potential of genomic features. Ultimately, my findings suggest that tumour genomics are biased to host characteristics, that there are many underlying sources for these genomic differences, and that they can be leveraged to improve biomarker design.
The Sound of Queer Diaspora: Sonic Enactments of Filipinx Desire, Loss and Belonging
Keywords: Aesthetics
Diaspora
Filipinx
Media
Queer
Sound

In this dissertation, I foreground Filipinx cultural production in building an aesthetic archive of transpacific aesthetic expression. From this point, I listen for its queer sounds. My research draws on queer theory, performance studies, and Filipinx diaspora studies to suggest that sound offers a methodological framework that can uniquely register modes of collectivity and desire that may otherwise go unrecognized. I also deploy psychoanalytic concepts of mourning and reparation to elaborate a definition of sound that explains its material and metaphorical force as it creates conditions for new relational possibilities. Broadly, I suggest that sound has an affective quality that capaciously allows Filipinx diasporic subjects to create forms of home, desire, and belonging that defy racialized ascriptions born from racism, colonialism, and their gendered dimensions. This dissertation includes four chapters, each offering a critical reading of an aesthetic object. The objects that I have assembled in this dissertation include videos that feature performances by Filipinx children, visual art and music by Filipinx artists, and a film that expresses the queer dynamics of sound. By critically listening for queer sound as it is produced by these aesthetic objects, I hope to contribute a theory of diaspora that may otherwise be rendered unintelligible due to hegemonies of vision, empire, and heterosexuality. Ultimately, this project seeks to expose how sonicity can inhabit the affective force of desire, loss, and belonging in queer, transpacific representation.
The Durability of Client Regimes: Foreign Sponsorship and Autocracies, 1946-2010
Keywords: authoritarianism
civil-military relations
cold war
great power foreign policy
military coups

This dissertation investigates the relationship between foreign support and the survival of authoritarian regimes. Conventional wisdom suggests that great power patrons prop up client dictatorships. However, this is generally assumed rather than systematically analyzed. My dissertation provides the first comprehensive assessment of the relationship between foreign sponsorship and authoritarian regime survival with the use of an original dataset of all autocratic client regimes in the postwar period. These results demonstrate that patronage from Western powers - the United States, France, and the United Kingdom - is not associated with client regime survival. Instead, only Soviet sponsorship reduces the risk of regime collapse. I explain this variation by considering the effects of differing strategies of foreign sponsorship on client regime coup vulnerability. Not a single Soviet client regime ever lost power to a military coup. This was the result of Soviet assistance in the implementation of highly penetrative coup prevention strategies that rendered militaries incapable of ousting incumbent regimes. In contrast, a fundamental ambivalence toward their autocratic allies and a focus on building Western-style militaries rendered U.S. and European clients highly vulnerable to coups. Western clients did not receive patron assistance in restructuring their security forces to prevent a coup and were abandoned in the event of a successful coup. I test these arguments using recently declassified archival sources, secondary sources in English and Russian, and a series of statistical analyses using both original and newly available data.
Development and Evaluation of an Instrument to Measure Discharge Planning Processes in Mental Health Care
Keywords: discharge planning
instrument development
mental health
nursing research
quality indicators

Objective: The purpose of this study was to develop and test an instrument to measure and evaluate the quality of discharge planning processes in mental healthcare settings. Methods: Three major study phases were involved in the development of the instrument: 1) conceptualization of discharge planning, 2) item development, structure, and format, and 3) pilot testing of the instrument. Phase I comprised three components: a concept analysis and literature review to identify domains and indicators of discharge planning, focus groups with key informants to validate these findings, and a two-round Delphi study with a multidisciplinary expert panel to determine which indicators were most important for measuring the quality of discharge planning processes. In Phase II, indicators that reached expert consensus in Phase I were formatted into instrument items. In Phase III, the instrument was pilot tested through chart reviews and cognitive interviews. Results: The concept analysis and literature review yielded 73 quality indicators in six domains: Comprehensive Needs Assessment; Collaborative, Patient-Centered Care; Resource Availability Management; Care and Service Coordination; Discharge Planner Role; and Discharge Plan. Following the focus groups, two additional domains were created (i.e., Information Gathering and Synthesis, Patient Capacity Assessment), nine indicators were added, and three indicators were removed. In the first Delphi round, 37 panelists rated the importance of 79 quality indicators. Fifty-four indicators were retained and the Discharge Planner Role domain was removed after this survey round. In the second Delphi round, 36 panelists rated the importance of three new indicators. Two indicators were retained, resulting in a final set of 56 indicators. In Phase II, each indicator was assigned an item response option. In Phase III, the instrument was pilot tested and revisions were made to the instrument items, response scales, and overall format and instructions. These refinements resulted in a 57-item instrument. Conclusions: The instrument developed in this study can be used by healthcare providers to provide insight into practice and knowledge gaps in care, organizational leaders to inform process and structural improvements in mental healthcare settings, and policymakers to design more effective policies and practice guidelines for safer care transitions from hospital to community.
Organic Materials for Energy Generation and Storage
Keywords: Energy Storage
Graphene
Polymers
Supercapacitors

In this thesis, I describe my efforts in developing organic materials for energy storage and generation. Chapter 1 introduces the broad classes of organic materials that are the focus of the thesis, including graphene, small molecules and conjugated polymers. It provides background into the principles of energy storage in supercapacitor devices, including the mechanism, performance metrics, and common materials. It provides a brief overview of energy generation in photovoltaic devices, with a focus on the electron transport layers of perovskite solar cells. Chapter 2 explores synthesis of a graphene quantum dot/poly(3,4-ethylenedioxythiophene) (PEDOT) film for application as a supercapacitor electrode. I demonstrate the first electrochemical polymerization of functionalized graphene quantum dots. I determined that the graphene quantum dot/PEDOT films have significantly higher capacitance than control films, but reduced cycling stability. Chapter 3 investigates a polymer comprising PEDOT with tetrachlorinated perylene diimide pendant units. This polymer was designed to serve as a stable ambipolar electrode for application in symmetric type III supercapacitor devices. It demonstrates moderate capacities, but the donor-node-acceptor architecture grants it extremely good charge cycling stabilities in both positive and negative regions. In Chapter 4, I examine a graphene quantum dot/perylene diimide material for application in perovskite solar cells. This material was demonstrated to successively quench the fluo- rescence of a perovskite material, indicating its potential as an electron transport layer. It is hoped the graphene will facilitate electron extraction at the electrodes, in addition to providing improved stability to ultraviolet, thermal and chemical degradation to perovskite solar cell. Chapter 5 examines the potential to dope graphene with tellurium for use as a non-precious metal catalyst for the electrochemical reduction of oxygen in basic aqueous medium. It was demonstrated that graphene oxide could be simultaneously thermally reduced and doped with tellurium, and the resulting Te-doped graphene showed potential as an electrocatalyst. The doping was unable to be suitably controlled and resulted in inconsistent Te-doping, tellurium oxidation states and oxygen content within the Te-doped graphene. In Chapter 6, I detail a simple microwave-assisted synthesis of carbon nanodots, and screen potential precursors to allow the controlled doping of carbon nanodots with heteroatoms. It was demonstrated that the carbon nanodots could be rapidly synthesized, and heterogeneous mixtures of precursors allowed modification of the optical properties of the synthesized carbon nanodots. Chapter 7 serves to summarize the thesis, provides future outlooks on the topics covered, and proposes future research directions in the field to generate high performance organic ma- terials for energy storage and generation.
Altered Excitation-inhibition Balance in Depression and Stress: Contributing Pathology and Treatment Target
Keywords: Depression
Excitation
GABA
Inhibition
Somatostatin
Stress

Lifetime exposure to severe or lasting stressors is a shared risk factor across psychiatric illnesses that together account for one-third of global years lost due to disability, including major depressive disorder (MDD), anxiety disorders, and post-traumatic stress disorder (PTSD). Evidence from human and animal studies demonstrates alterations in cellular and molecular components of excitation-inhibition balance (EIB) as central to these illnesses. These include deficits among excitatory glutamatergic neurons, inhibitory GABAergic interneurons, and glial cells. Concurrently, first-line antidepressant drugs (ADs) achieve insufficient response, low remission, and high relapse rates, in part because they do not directly target primary pathological alterations to EIB components. Although recent advancements have been made with rapid-acting ADs targeting excitatory alterations, several pathological targets among EIB components remain unexplored. This thesis investigated how deficits in cellular and regional mediators of EIB, as informed by human pathological findings, contribute to preclinical behaviors reflecting symptoms of chronic stress-related disorders. Using transgenic mice with brain-wide low somatostatin-positive GABAergic interneuron (“SST+ cell”) function, we first identified that inhibitory SST+ cells regulate depressive-, anxiety-, and anhedonia-like behaviors, plus memory impairment, supporting evidence that primary SST+ cell deficits in humans contribute to MDD symptoms (Study 1). In chronic stress-exposed mice, we next identified that stress-related behavioral deficits emerge partly through altered EIB, specifically, enhanced functional activation of the anterior cingulate cortex and ventral hippocampus (Study 2). We then evaluated the therapeutic potential of novel AD strategies targeting excitatory homeostasis or inhibitory components of EIB. Prophylactic administration of riluzole, a drug that regulates excitatory glutamate homeostasis, enhanced resilience in chronic stress-exposed mice (Study 3). In transgenic mice with SST+ cells silenced, potentiation of α5-GABA-A receptors (that partially mediate inhibitory SST+ cell functions) revealed antidepressant potential, demonstrating a proof-of-concept for emerging therapeutic mechanisms bypassing SST+ cell pathological changes (Study 1). These studies contribute evidence linking disrupted EIB to behavioral deficits related to symptoms of psychiatric illnesses and support antidepressant mechanisms targeting components of altered EIB. The insights from this work have potential to advance precision diagnosis and treatment of MDD and other neuropsychiatric disorders linked to chronic stress.
Cutting the Knot: Founding Canada and Restoring the Honour of the Crown
Keywords: de jure
honour of the crown
indigenous
reconciliation
sovereignty
treaty

The honour of the Crown in Canadian Aboriginal jurisprudence has taken on a prominent role in interpreting s.35 of the Constitution Act 1982, cited as grounding, at a minimum, Crown responsibilities to consult and accommodate. Yet what is not often discussed is the over 800 year long legal legacy of the honour of the Crown in common law and equity and that our understanding of Crown honour today appears greatly narrowed and underapplied in contrast. I offer a more full and complete understanding of the roots of the honour of the Crown and its relevance to the Crown's relationship to Indigenous peoples with the hope of offering a new lens through which to more properly understand those relationships, those treaties made on the basis of Crown honour, and the path of reconciliation itself.
Characterization of 13C-Lactate Signals for the Application of Hyperpolarized 13C MRI in Intracranial Metastasis Patients
Keywords: Brain
Cancer Metastasis
Hyperpolarized 13C MRI
Lactate
Metabolic Imaging
Pyruvate

Intracranial metastasis is a clinical heterogeneous disease, commonly treated with radio- therapy. However, diverse treatment outcomes and potential side effects associated with aggressive radiotherapeutic approach makes it essential to identify which patients will benefit from such treatment. Elevated lactate production in metastatic tissues has been proposed by other researchers as a metabolic biomarker for radiation resistance in cancer patients. Hyperpolarized 13C MRI is an emerging metabolic imaging modality that can detect 13C-lactate production in tissues from the injected “hyperpolarized” 13C-pyruvate. This imaging modality has been steadily evolving towards clinical translation over the last decade, leading to a number of recent publications demonstrating the feasibility of implementing this tool to acquire 13C-lactate images in the human brains. However, even healthy brain tissues generate high 13C-lactate signals from the injected 13C-pyruvate. Moreover, there are a number of biological components involved in the 13C-lactate production from the injected 13C-pyruvate, making it difficult to accurately interpret the acquired 13C-lactate signals. As a result, the optimal approach to characterize these 13C-lactate signals for the clinical assessment of intracranial metastasis remains under investigation. In this dissertation, approaches to enhance our understanding and characterization of 13C-lactate signals is described. The pre-clinical experimental approach was designed to investigate the correlations between biological components of lactate metabolism and 13C-signals. The conventional method to characterized 13C-lactate signals (i.e. lactate- to-pyruvate ratio) was confirmed to strongly correlate to [1-13C]lactate concentration but not to the total lactate pool size in metastatic tumour xenograft model. Accordingly, a novel approach of characterizing 13C-lactate signals as ‘z-score’ in the human brain was developed. This segmentation-based approach was implemented to investigate 13C-lactate metabolism in the control human brains and revealed that the human brains have consistent region-specific lactate biology. This approach was further extended to characterize 13C-lactate signals in 14 intracranial metastatic lesions in 10 patients. A median split analysis suggested that lactate z-scores may be better predictors of clinical progression following radiation treatment than the conventional lactate-to-pyruvate ratio approach. This suggested that the approach described in this thesis can potentially improve clinical assessment of intracranial metastases in response to radiation treatment using the information stored in 13C-lactate images.
Technocracy
Keywords: Arts
Communication
Composition
Music
Orchestra
Politics

Technocracy is a twelve-minute, single-movement work for orchestra. Divided into three sections, Technocracy nods at the rhetorical thrust of traditional sonata form insofar as two contrasting sets of musical material are juxtaposed against one another then subsequently resolved within a single movement. However, whereas the recapitulation of a traditional sonata resolves the secondary theme to the key of the primary theme via some form of alteration, the final section of Technocracy balances the material of the prior sections without altering one to accommodate the other. Section A organizes pitch horizontally through a series of twelve chords that are constructed, as much as possible, from stacked tonal triads. These chords progress gradually from a twelve-note aggregate presented at the opening to a single note that signals the transition from Section A to Section B. Throughout Section A, there is no clear instrumental hierarchy, and sudden dynamic shifts combined with unpredictable repeating rhythms, create the impression of chaos. Section B retorts the horizontal pitch organization of Section A with a series of tone rows. While Section A lurches between dynamic extremes, Section B is a relatively steady trajectory from soft to loud. In Section A, chaos reigns, whilst in Section B, the instrumental hierarchy is clearer; winds and brass present melodic material while the strings and percussion provide support. Section C of Technocracy consolidates the ideas presented in the preceding sections. It combines the tone rows of Section B with the chord progression of Section A. By maintaining a strong sense of pulse and forward motion, it consolidates the rhythmic unpredictability of Section A and the relative stasis of Section B. Finally, Section C strikes a balance between the orchestrated chaos of Section A and the clear hierarchy of Section B.