VictorJuiz/thesis huggingface dataset:
Welcome Back a Yard: Jamaican Imaginings of the Diasporan Homebuyer

This study is a transnational ethnography of Jamaica’s diasporic real estate market. Synthesizing performative and institutional frameworks from economic sociology, I intervene in extant debates on diaspora and development over the nature of markets and their influence on diasporan attachments to nation. Rather than problematizing how an abstract market rationality influences diasporans’ incorporation into the nation, an economic sociology approach problematizes the role of diaspora engagement projects in constructing and transforming markets which incorporate the diaspora. Entering this problematic, this study asks: How do real estate professionals imagine the diasporan homebuyer, and what role does that imagination play in the conception of control of Jamaica’s housing market? What sales tactics and approaches do real estate professionals use to sell gated community homes to diasporans? How is the imagined diasporan homebuyer reflected and/or produced through those practices? How do they objectify both the product and the customer they are meant to attract? I argue the diasporan homebuyer is imagined according to three key tropes from Jamaican public discourse: diasporans are affluent relative to Jamaicans, nostalgic for a Jamaica they left but estranged from the Jamaica to which they wish to return. The affluent, nostalgic but estranged diasporan is understood as a solution to an historical problem in Jamaica’s housing industry: a market whose successive conceptions of control have cornered firms into building and selling homes unaffordable to most Jamaicans. These tropes form a schema of value for the gated community home and their intended customers. Sales practices informed by that schema objectify gated community homes through qualities of value, trust and security as concerns calculated to appeal to affluent, nostalgic and especially estranged homebuyers. At the same time, the diasporan homebuyer is objectified through a sales approach intended to exploit (or produce) the tension between nostalgia and estrangement. Real estate professionals value affluent, nostalgic and estranged diasporans as customers to whom they can commodify their own reputations and knowledge of Jamaica. As such, sales practices are designed to “sift” the heterogeneity of the real diaspora to find and/or perform the idealized diasporan homebuyer of professionals’ imaginations.

Keywords: commodification
diaspora
Jamaica
markets
real estate
Advisor: Landolt, Patricia
Molecular Characterization of the Spectrum of Peripheral Nerve Sheath Tumors

Malignant peripheral nerve sheath tumor (MPNST) is a highly aggressive sarcoma, and the most lethal form of cancer in the context of neurofibromatosis type 1. The current standard of care includes surgery plus radiation, with no effective chemo or targeted therapeutic options. Here we examined the genomic and epigenomic drivers of MPNSTs, analyzing 108 tumors spanning the full spectrum of peripheral nerve sheath tumors, using a multiplatform integrated approach to identify drivers of MPNST. We established through multiple unsupervised analyses of methylome and transcriptome profiles that there exist two distinct pathways of malignant transformation leading to MPNSTs, one through SHH pathway activation (MPNST-G1) and the other through WNT pathway activation (MPNST-G2). We discovered distinct copy number aberration, mutational profiles, and targetable oncogenic programs that define each sub-group. Further, single nuclear RNA sequencing characterizes the complex cellular architecture that defines each subgroup, with MPNST-G1 and MPNST-G2 resembling neural crest-like and Schwann cell precursor-like cells, respectively. Additionally, in-vitro and in-vivo models confirm that inhibition of the SHH pathway can prevent growth and malignant progression of MPNSTs, proving sonidegib to be novel therapeutic option in these lethal cancers.

Keywords: genetics
malignant peripheral nerve tumors
molecular characterization
peripheral nerve tumors
sarcoma
Advisor: Zadeh, Gelareh
“Thinking Outside the Box”: A Snapshot of Child and Adolescent Therapists’ Early Experiences Adapting Services to the COVID-19 Context

COVID-19 has had numerous impacts on the general population, including increased physical health risks, social isolation, and prolonged uncertainty (Gruber et al., 2020). Some have argued these impacts disproportionately affect younger populations (Powell et al., 2020). Within Canada, there has been a sharp uprise in children/youth accessing the Kids Help Phone over the past 18 months (Watson, 2020), underscoring the importance of continued access to mental health supports for this population. Child/youth practitioners have faced the arduous task of transitioning their services online, which may be uniquely challenging to accomplish with younger clients. This study employed a mixed-methods concurrent embedded design to explore the experiences of 36 child/youth therapists in Ontario as they have navigated this new professional landscape. An interpretative phenomenological analysis revealed both negative and positive impacts of COVID-19. Therapists reported feelings of reduced self-efficacy, difficulties engaging with and interpreting nonverbal communication using virtual mediums, technological challenges, and personal challenges relative to balancing work/home commitments as primary challenges. Younger clients appeared most significantly impacted due to developmental challenges inherent in online engagement. In response, therapists described creatively adapting their services, relying on team members or others for support and/or consultation, and various self-care strategies. Positively, many therapists felt youth were benefitting from the increased accessibility of virtual services. Despite the challenges identified, a repeated-measures MANOVA revealed no significant changes to therapist self-reported state empathy levels when reflecting on challenging clinical interactions prior to and since the onset of COVID-19. Implications for future research and clinical practice are discussed.

Keywords: children
COVID
technology
telehealth
therapy
youth
Advisor: Ferrari, Michel
Homeostatic Control of Nuclear-encoded Mitochondrial Gene Expression by the Histone Variant H2A.Z is Essential for Neuronal Survival

Histone variants are crucial regulators of chromatin structure and gene transcription, yet their functions within the brain remain largely unexplored. Here we show that the H2A histone variant H2A.Z is essential for neuronal survival. Mice lacking H2A.Z in GABAergic neurons or Purkinje cells (PCs) present with a progressive cerebellar ataxia accompanied by widespread degeneration of PCs. Ablation of H2A.Z in other neuronal subtypes also triggers cell death. H2A.Z binds to the promoters of key nuclear-encoded mitochondrial genes to regulate their expression and promote organelle function. Bolstering mitochondrial activity genetically or by organelle transplant enhances the survival of H2A.Z-ablated neurons. Changes in bioenergetic status alter H2A.Z occupancy at the promoters of nuclear-encoded mitochondrial genes, an adaptive response essential for cell survival. Our results highlight that H2A.Z fulfills a key, conserved role in neuronal survival by acting as a transcriptional rheostat to regulate the expression of genes critical to mitochondrial function.

Keywords: Cerebellum
Epigenetics
Histone
Mitochondria
Neurodegeneration
Advisor: Cheng, Mary
The Molecular Determinants of Response to Immune Checkpoint Therapy in Solid Tumors

Immune checkpoint therapy (ICT) has demonstrated lasting clinical benefit unparalleled by other cancer treatments in a small percentage of patients. Thus, optimizing patient selection, monitoring emerging resistance, and understanding resistance pathways remain significant challenges for improving ICT efficacy and personalization. In the absence of appropriate preclinical models of cancer immunity, clinical trials supported by next generation sequencing and data-driven experimental designs have enabled simultaneous characterization of cancer cells, their immune contexts, and microenvironment to support biomarker evaluation and discovery. This dissertation describes the design and implementation of a centralized biospecimens processing and immunogenomic data workflow for the phase II basket trial of pembrolizumab ICT in metastatic solid tumors (INSPIRE; NCT02644369), followed by the in-depth integrated analysis of the sequencing and clinical data to identify molecular features associated with therapeutic efficacy. In chapter 2, we reported the technical feasibility of conducting DNA and RNA sequencing and immune monitoring assays on serial blood and tumor samples for biomarker evaluation. In chapter 3, we used personalized mutation panels designed from matched patient normal-tumor exomes to quantify changes in circulating tumor DNA (ctDNA) burden during treatment. We showed that ctDNA increases within 6 weeks of treatment initiation were associated with disease progression across all tumor types. ctDNA dynamics also paralleled target lesion changes suggesting its potential as a sensitive and minimally invasive method to detect therapeutic resistance in patients undergoing ICT. Building on this new molecular response framework, in chapter 4, we integrated ctDNA and target lesion dynamics to stratify patients into distinct prognostic groups for correlative analysis of tumor exomes and transcriptomes. This tumor-agnostic approach enabled us to elucidate pharmacodynamic effects of pembrolizumab by comparing matched baseline and on-treatment tumor tissues and to identify biomarker candidates and correlates of therapeutic response.

Keywords: Biomarkers
Cancer Genomics
Cancer Immunology
Immunotherapy
Precision Medicine
Tumor microenvironment
Advisor: Pugh, Trevor J.
Queering and Trans-gressing Care: Towards a Queer Ethic of Care in QTBIPOC Education

This research details the findings from three interviews with QTBIPOC educators in Ontario. Using qualitative interviews and art-based responses, teachers in this study theorized about a queer ethic of care while offering their best practices to illustrate how they move from theory to pedagogy when working with QTBIPOC youth. This research asked the following questions: How do QTBIPOC educators understand and practice a queer ethic of care? Two findings emerged from this study: (1) a queer ethic of care is nuanced and expansive, disruptive and transgressive and an individualized practice that takes place within a care web and (2) care as it exists in schools right now, is inherently white, colonial and violent and has forced QTBIPOC educators to imagine new forms of care practices. These disruptive practices include creating (1) authentic, fluid, mutually vulnerable relationships with students (2) explicitly anticolonial, antiracist moments in their teaching and interactions with students and (3) affirmation and recognition as moments of healing. Collectively, these disruptive and transgressive practices create space for mutual healing for both queer and trans racialized students and teachers and paves the way for queer futurity and thriving. The findings from this study indicate a few things: educators must continually reimagine and disrupt their knowledge of care and care practices that are built upon white, colonial, cisheteronormative assumptions; educators must engage in anticolonial and antiracist care practices that are trans-gressive to the understandings of care in schools; teachers must learn how to create care webs in community with their students in ways that are vulnerable, authentic and fluid; a queer ethic of care is possible to implement at the grassroots, individual level first, but must move towards systemic practices in order to be sustainable and effective for QTBIPOC students in the long term; and a queer ethic of care offers a way for QTBIPOC teachers and students to feel recognition, affirmation and mutually heal by imagining new futures through thriving, joyful care.

Keywords: care work
colonialism
gender and sexuality education
race
teacher education
Advisor: Goldstein, Tara
Identifying Vulnerabilities for Diversion of Controlled Substances to Inform The Safeguards Needed in Canadian Hospitals to Protect Patients and Healthcare Workers

Introduction: Diversion or theft of controlled substances (CS) is a recognized problem affecting healthcare systems globally. Diversion from hospitals can occur through falsifying orders, tampering with medications, and pilfering stock. The impacts of diversion are serious, causing severe harm to patients, healthcare workers, hospitals, and the public. Selecting effective interventions for safeguarding against diversion cannot occur without first having a thorough understanding of how the hospital system is susceptible to diversion. Aims: To establish a detailed understanding of how hospital medication-use processes are vulnerable to CS diversion, characterize the vulnerabilities, and develop a framework to conceptualize how system factors set the stage or shape processes for diversion to take place. Study Design/Approach: Guided by the System’s Engineering Initiative for Patient Safety (SEIPS) Human Factors model, I used a multimethod study design comprised of observations that informed a Healthcare Failure Mode and Effect Analysis (HFMEA) to identify critical failure modes (CFMs) in two Ontario hospitals in the inpatient pharmacy (Study 1), emergency department (ED) (Study 2), and intensive care unit (ICU) (Study 3). The prospective analysis was followed by a framework analysis to build a conceptual framework for diversion. Results: Study 1 demonstrated that CFMs provide detailed descriptions of vulnerabilities which exist in every medication-use process involving CS. Studies 2 and 3 built on these finding and showed that all CFMs stemmed in part from person-related factors (e.g., intentional actions to falsify documentation), but were always also precipitated by technology-, organization-, environment-, or task-related deficits in how healthcare systems are designed and organized. I developed a novel framework based on findings from Studies 1-3 to conceptualize the relationship between system factors and how they interact and coalesce to enable pilfering and/or forgery which leads to diversion-related harms. Conclusion: My thesis findings further our understanding of diversion as a systems issue, whereby vulnerabilities stem from failures not only by individual actions, but in the interaction between processes, technologies, environments, and organization factors. My framework can be used to inform broader efforts to develop guidelines and technological solutions for Canadian hospitals.

Keywords: Controlled Substances
Diversion
Health system safety
Hospitals
Advisor: Trbovich, Patricia
U-Pb Dating of Fossils and Hydrogenic Minerals: Toward Practical Paleontological Chronometry

This thesis studied the feasibility of using laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) for U-Pb dating of fossil and pedogenic carbonates. New LA-ICPMS data using improved processing methods provide early diagenetic U-Pb ages of fossils and constrain the mechanisms of trace element mobility during late-diagenesis. The first accurate U-Pb age on fossilized soft tissue, yields an age of 3.16 ± 0.08 Ma consistent with its late Pliocene stratigraphy while coexisting shark teeth are variably reset by late-diagenesis. A study of late diagenetic overprinting in dentine versus enamel of another shark tooth within a phosphorite allows both early and late-diagenetic ages to be extracted and challenges the current syn-sedimentary model of phosphorite formation. Apatite fossils such as conodonts and brachiopods show high Th/U ratios combined with evidence of significant excess 206Pb. This requires large (>104) Th enrichment factors during diagenesis. In a study of calcite invertebrate fossils, the apical line of belemnites was found to be enriched in U, allowing dating of belemnites for the first time while dating of rugose corals agreed with previous isotope dilution results. This shows that LA-ICPMS U-Pb dating can be effective on samples with <1 ppm U. Pedogenic carbonate nodules from an early-Triassic conglomerate unit in the Karoo Basin, South Africa have been successfully dated to precisions of (±1-2 Ma). The maximum depositional age determined from the nodules is consistent with the early-Triassic stratigraphic age. Carbon isotopes in nodules can be used as proxies for atmospheric CO2 content so more precise dating by ID-TIMS combined with C isotope analysis may reveal a detailed record of CO2 increase associated with mass extinction. The possibility of dating early hominid cave settlements using vertebrate fossils was explored. Fossil tortoise shells show high U contents and are thus free from biases that could affect currently used speleothem ages. However, they show restricted ranges of U/Pb and are less radiogenic than speleothem data, limiting age precision to about ±1 Ma by LA-ICPMS. Age errors could be improved by measuring more precise data using ID-TIMS and by application to a wider variety of fossils within caves.

Keywords: Geochronology
LA-ICPMS
U-Pb Dating
Advisor: Davis, Don W.
Three Essays on the Economics of Digitization and Industrial Organization

This dissertation is composed of three chapters. The first, jointly authored with Jin Huang and Yuxin Chen, both from NYU-Shanghai, explores the economic role of price trackers. The second, jointly authored with Jin Huang, studies limited-time offers in the search market. Finally, the third one studies content design in the influencer market. In the first chapter, we investigate how the presence of online price trackers changes consumers' behaviors and market equilibrium by providing historical price information. We build a theoretical framework and find that a monopolist seller uses a high-low cyclical dynamic pricing when consumers are unaware of past prices. With the rise of price trackers, more consumers become informed about historical prices, which results in lower regular prices and more frequent sales. We study the economic role of limited-time offers in the second chapter. We highlight that consumers need time to investigate each product, and firms can endogenously direct the consumer search order by advertising limited-time offers, inducing potential consumers to sample its product early. We show that the length of limited-time offers depends on the reservation values of products to the consumer. A firm with a higher reservation value product gives a shorter sale in equilibrium, and is investigated earlier in a consumer's endogenous search order. This implies that search competition with limited-time offers leads to a socially efficient search order in equilibrium. In the last chapter, I aim to understand how new firms grow and establish themselves through their product design. I answer this question with theoretical modeling and empirical findings on the online influencer market. I collect new blog post data from WeChat Official Account, and use machine learning methods to categorize the topics and advertising in posts. I find that new entrants to the influencer market begin their careers by specializing in niche topics with minimal advertisements. Over time, they cover a wider range of topics, and the extent of advertising grows. To understand the underlying mechanism, I develop a theoretical model of dynamic reputation and content design. And I employ a shock to the reputation of influencers to cross-validate the model.

Advisor: Bar-Isaac, Heski
Mitchell, Matthew
Hybrid Nonlinear Control Systems: Stability, Optimality, Dissipativity, and Spacecraft Applications

Hybrid dynamical systems, as an emerging discipline within dynamical systems theory and control, can be defined an interacting collection of dynamical systems involving a mixture of continuous-time and discrete-time dynamics. Exhibiting continuous evolution and instantaneous changes on appropriate manifolds, hybrid dynamical systems consist mainly of three elements: a continuous-time set of differential equations, which characterizes the motion of the dynamical system between discrete-time events; a discrete-time set of difference equations, which governs discontinuous changes in the system state; and a criterion to determine when discrete-time dynamics are to be applied.Stability, optimality, and dissipativity of hybrid nonlinear time-dependent dynamical systems are considered in this thesis. Control design frameworks of optimal and passivity-based characters are accordingly developed for hybrid nonlinear dynamical systems involving an interacting amalgam of continuous-time and discrete-time dynamics whose dynamical properties evolve periodically over time. The overall framework, in fact, provides a solid foundation for extending hybrid linear control to nonlinear control synthesis. To this end, a hybrid version of the underlying mathematical formulation characterizing optimality and dissipativity for hybrid nonlinear time-dependent dynamical systems is first presented. A hybrid computational framework, which alternates between continuous-time and discrete-time subsystems at an appropriate sequence of time instants, is subsequently developed to solve the resultant set of equations in an interacting manner. The outcome is therefore a hybrid nonlinear time-varying control law which combines a continuous-time control input with impulsive control inputs in accordance with a resetting criterion. Practical considerations for implementing the proposed control design frameworks are subsequently discussed in detail. The proposed control design schemes are ultimately utilized to synthesize hybrid controllers of a nonlinear nature for two real-world spacecraft applications: spacecraft attitude regulation with a hybrid source of magnetic and impulsive actuation, and spacecraft formation flying under the actions of the Lorentz force and impulsive thrusting.

Keywords: Galerkin/Collocation-based Approximation
Hybrid Dynamical Systems
Hybrid Nonlinear Optimal Control
Hybrid Nonlinear Passivity-based Control
Spacecraft Attitude Regulation utilizing Magnetic and Impulsive Actuation
Spacecraft Formation Flying using Lorentz Force and Impulsive Thrusting
Advisor: Damaren, Christopher J.