VictorJuiz/thesis huggingface dataset:
A Risk Stratification Model for Adult Patients with Obstructive Sleep Apnea: Development and Evaluation
Keywords: clinical epidemiology
Sleep-Disordered Breathing
long-term adverse outcomes
predictive modelling

Despite emerging evidence that obstructive sleep apnea (OSA) may cause cardio-metabolic disturbances independently of known risk factors, the strength and significance of this association remains unclear. This thesis is comprised of three studies assessing the long term-consequences of OSA, and specifically the prognostic value of OSA-related variables for cardiovascular (CV) events, all-cause mortality and incident diabetes. Methods: The first study is a systematic review of longitudinal studies, from 1999 to 2011. Quality was assessed using published guidelines. Studies two and three linked a clinical sleep database to Ontario health administrative databases for the period of 1991 to 2011 to examine the relationship between OSA variables and a composite CV outcome and incident diabetes. For the latter, we assembled a cohort free of diabetes at baseline, as defined by health administrative data. Cox regression models were used to investigate the association between of OSA-related predictors and outcomes of interest, controlling for potential confounders. Study one identified significant relationships between OSA and all-cause mortality and composite CV outcome in men; associations with other outcomes remain uncertain. Among OSA-related variables, only apnea-hypopnea index (AHI) was a consistent predictor. Limitations of the clinically-based studies were small numbers of events, weak definitions of outcomes, and inconsistency in polysomnographic scoring criteria over time. Study two found that 1,172 (11.5%) of 10,149 participants experienced our composite CV event over a median follow-up of 68 months. In a fully adjusted model, the following OSA-related variables were significant independent predictors: time spent with oxygen saturation (SaO2) < 90%, sleep time, awakenings, periodic leg movements, heart rate, and presence of daytime sleepiness. In study three, of 8,678 cohort participants without diabetes at baseline, 1,017 (11.7%) developed incident diabetes over a median follow-up of 67 months. In fully-adjusted models, patients with AHI > 30 had a 30% higher hazard of developing diabetes than those with AHI < 5. Among other OSA-related variables, REM-AHI, and SaO2<90%, heart rate and neck circumference were associated with incident diabetes. Conclusions: Based on these studies, we demonstrated that OSA-related predictors significantly and independently contribute to the risk for occurrence of composite CV outcome and incidence diabetes.
Semantic-aware Anomaly Detection in Distributed Storage Systems
Keywords: Storage Systems
Anomaly Detection

As distributed storage systems become central to business operations, increasing their reliability becomes an essential requirement. Towards this goal, distributed storage systems come equipped with various monitoring probes. As a result, they generate massive amounts of monitoring data. The amount and complexity of such monitoring data surpasses the human ability to detect anomalies in this data. Our thesis is that, in order to obtain a practical solution to the reliability issues posed by modern distributed storage systems, the semantics of these systems must be incorporated into the anomaly detection process. Our semantic-aware approach enables digesting large amounts of monitoring data, through statistical methods, into a few human understandable patterns. These selected unusual patterns provide intuitive pinpointing towards the possible root causes of an anomaly; they can be leveraged by the human in the loop for root-cause anomaly analysis and related investigations. Our strengths lie in the lightweight, minimal overhead of our techniques, as well as their sensitivity to detect even subtle and localized unusual patterns. In this dissertation, we introduce three semantic-aware anomaly detection techniques: i) anomaly detection based on validation of high-level invariants, ii) stage-aware anomaly detection through runtime tracking of execution flows inferred from existing log statements in the code, and iii) a composite anomaly detection model using cross-component correlations. We studied our methods in two realistic environments: networked multi-tier storage systems used in enterprise settings, and a variety of scalable distributed storage platforms used in large data centers, i.e., HBase, HDFS and Cassandra. Our evaluation shows that our methods are lightweight, introducing negligible overhead, and detect anomalies in real-time.
Comparison between the Helen Iron Formation (Algoma-type) and the Sokoman Iron Formation (Superior-type)
Keywords: iron formation
geochemistry
petrology
REE
carbon isotopes
geology
Precambrian

The Sokoman Iron Formation with an age of 1.88 Ga in the Labrador Trough and the Archean Helen Iron Formation in Wawa, Ontario (2.75 Ga) are examples of shallow and deep water iron formations respectively, which are of a low metamorphic grade. The two iron formations vary greatly in their mineralogy and geochemistry. The deep water Helen Iron Formation is dominated by siderite and quartz and provides an example of a direct precipitate from seawater which had a strong but distal hydrothermal component as indicated by the lack of Cu, Pb and Zn enrichment. It has a thickness of 100m. The first 20 meters are dominated by input of detrital material of both basaltic and felsic sources before deepening of the basin led to purely chemical sedimentation. Iron in the Helen Iron Formation occurs predominantly as Fe2+, indicating that oxygen played no role in the deposition of this iron formation. Negative carbon isotope excursions close to organic rich horizons in the Helen Iron Formation are the result of dissimilatory iron reduction. In contrast, the mineralogy of the Sokoman Iron Formation is dominated by magnetite, hematite and quartz and has a thickness of 180m. The depositional environment was variable and ranged from a fairly deep, reducing basin to shallow, oxidizing water. The original mineralogy probably consisted of a silica-iron hydroxide gel which was precipitated due to oxidation of Fe2+to Fe3+. The source of the Fe2+ was probably a distal hydrothermal input. Anoxic deep water allowed the transport of Fe2+over long distances to the site of iron formation deposition. When this deep, anoxic water mass came into contact with shallow water, which was enriched in oxygen due to the photosynthetic activity of cyanobacteria, a silica-iron hydroxide gel precipitated. Dewatering of this gel during burial caused the strong diagenetic overprint preserved in the section in which the original mineralogy is obscured. The high degree of diagenesis also explains the present low organic matter content of the Sokoman Iron Formation as well as the presence of Fe2+ minerals, since organic matter may have reacted as an electron acceptor reducing Fe3+ to Fe2+.
Task-based Imaging Performance in 3D X-Ray Tomography: Noise, Detectability, and Implications for System Design
Keywords: Image quality
Computed tomography
Detectability
Noise power spectrum
Modulation transfer function
Model observer

Quantifying imaging performance is an important aspect in the development, optimization, and assessment of medical imaging systems. This thesis addresses new challenges in the characterization of imaging performance for advanced x-ray tomographic imaging technologies. Central to the work is a task-based cascaded systems analysis framework that encompasses aspects of system geometry, x-ray beam characteristics, dose, detector design, background anatomy, model observers, and the imaging task. The metrology throughout includes Fourier domain descriptors of spatial resolution (modulation transfer function, MTF), noise (noise-power spectrum, NPS), noise-equivalent quanta (NEQ), and task-based detectability. Central elements and advances of the work include: a task-based model for 3D imaging performance in tomosynthesis and cone-beam CT (CBCT); generalization of imaging performance metrics to include the influence of anatomical background clutter; validation of the model in comparison to human observer performance; extension to dual-energy (DE) tomographic imaging; analysis of non-stationary (i.e., spatially varying) signal and noise characteristics; and extension to model-based statistical image reconstruction. In each case, the analytical framework demonstrates the importance of task-based assessment and the capability for system optimization in a fairly broad scope of clinical applications ranging from breast to abdominal and musculoskeletal imaging. The validity of the framework in describing “local” signal and noise characteristics is demonstrated under conditions of strong nonstationarity, ranging from simple phantoms to complex anthropomorphic scenes. In addition to providing a framework for system design and optimization, the analysis opens potential new opportunities in task-based imaging and statistical reconstruction, with examples demonstrated in the design of optimal regularization in iterative reconstruction.
The Integration of Safety Engineered Needles in Acute Care Hospitals: Opportunities and Challenges of Regulated Change
Keywords: Needlestick
Regulation
Qualitative
Evaluation

Needlestick injuries have been identified as an important modifiable risk factor associated with the transmission of bloodborne pathogens between patients and healthcare workers. A number of jurisdictions, including the province of Ontario, turned to regulation to accelerate the adoption of safety-engineered needles (SENs) for the prevention of needlestick injuries. Available surveillance data demonstrates that needlestick injuries captured in work-related emergency department records and workers’ compensation claims have not declined substantially in Ontario. Drawing on organizational change and implementation science theory, a qualitative instrumental case study design was used to examine the implementation of SENs in three acute care hospitals in Ontario. Program documents were reviewed and interviews were carried out with staff across the three hospitals. While all three hospitals responded to the regulatory requirements with integrity, there was evidence of inconsistent processes and outcomes, which may have been due to variation in the types of SENs that had been integrated, the organization’s readiness for change, and the implementation practices that were adopted. During the initial implementation phase some front-line workers developed strategies to avoid using the SENs. There was a conflict between the values healthcare workers placed on performance and patient care and the learning curve associated with the initial transition to SENs. Explanations as to why needlestick injuries continue to occur were organized under two themes: the importance of staff compliance and "being more careful" and the inevitability of injury as a consequence of the work environment. While further progress will be challenged by competing health and safety priorities, a renewed interested in this injury issue among front-line workers and health and safety professionals may produce better outcomes as there appear to be a number of opportunities to advance prevention efforts to further reduce ongoing needlestick injuries.
The Impact of Neighbourhood Context on Work-Family Conflict and Psychological Distress
Keywords: neighbourhood effects
work-family conflict
psychological distress
mental health

Does neighbourhood context influence work-family conflict (WFC) and its mental health consequences? If so, how do these associations unfold? And do these processes differ for men and women? My dissertation research addresses these significant and timely questions. Recent changes in work and family domains have led to unprecedented levels of WFC. However, theories and research on the topic to date remain limited, because they emphasize individual-level antecedents to the exclusion of broader contexts, including individuals’ neighbourhood of residence. My study is among the first to effectively examine the impact of neighbourhood context on WFC and mental health consequences. I outline three overarching mechanisms through which neighbourhood influences WFC, including (a) the social composition of the neighbourhood, (b) processes of neighbourhood structural amplification; and, (c) the objective and perceived presence of community resources. I test my hypotheses using data from Toronto, Canada, compiled from a variety of sources, including individuals, the Canadian census, and municipal data on community resources. I use Hierarchical Linear Modeling (HLM) techniques for all analyses to appropriately distinguish individual and neighbourhood-level variations. Collectively, the results from my dissertation research contribute to a more advanced framework of the antecedents of WFC and its mental health consequences compared to previous approaches—one that incorporates the importance of place.
Characterization of Phosphatidylinositol 4-kinase IIIα During Drosophila Development
Keywords: Drosophila
oogenesis
phosphoinositides
germline stem cells
Notch
phosphatidylinositol 4-phosphate

Phosphoinositides regulate diverse cellular processes such as actin organization, membrane trafficking, and signal transduction. However, the mechanisms by which phosphoinositides contribute to formation and patterning of tissue during development are not well understood. I have used Drosophila melanogaster to examine the role of phosphatidylinositol (PI) 4-kinase type IIIα (PI4KIIIα) during development. I generated a deletion in PI4KIIIα and discovered that this gene is essential and is required in multiple cell types for signaling during oogenesis. In the germline, PI4KIIIα is required for production of plasma membrane (PM) PI4P and its metabolic derivative, PI 4,5-bisphosphate (PIP2). PI4KIIIα is important for actin organization, membrane addition, and oocyte polarity. Moreover, PI4KIIIα orchestrates these processes through its cellular effectors, Moesin and the exocyst complex, by regulating phosphorylation and localization of Moesin, as well as PM recruitment of the exocyst. These effects are unique to PI4KIIIα, as egg chambers from flies mutant for either of the other Drosophila PI4Ks, fwd or PI4KII, show Golgi but not PM phenotypes. In addition, PI4KIIIα is required for axis specification and localization of the germ cell determinant Oskar, establishing an essential role for PI4KIIIα in egg chamber development. In follicle cells, PI4KIIIα is required for maintenance of epithelial architecture and Notch signaling during the stage 6-7 mitotic-to-endocycle switch, when follicle cells stop dividing and start endoreplicating their DNA. PI4KIIIα mutant posterior follicle cells show sustained Cut expression, continue to proliferate, and are impaired in their ability to induce oocyte axis specification. Thus, PI4KIIIα regulates Notch signaling and cell-cell communication. Finally, PI4KIIIα is also required for germline stem cell maintenance in the ovarian germline niche. PI4KIIIα mutant stem cells are unable to compete for niche occupancy and are soon expelled. Together, my results uncover essential roles for PI4KIIIα in developmental signaling and provide models in which to study the underlying molecular mechanisms of these pathways.
Poetic Inquiry Re-claiming Authority: Writing through Shame, Grief, and Silence
Keywords: Poetic Inquiry
Adult Literacy
Adult Learning
Shame
Grief
Silence
Don McKay
Lorri Neilsen Glenn
Marlene NourbeSe Philip
Don McKay
Poetic Writing Practices
Effects of Trauma on Learning

A story has a beginning. A poem begins. Beginning in the middle: our bodies hold our histories, in a wrestle with words. Typically, a thesis begins with an abstract, which summarizes and contextualizes the work. Poems begin differently: they may leap in with both feet or slip in gently, knowing some things are best approached cautiously. Emily Dickinson (1951/1976) says, “Tell all the Truth but tell it slant” (1129) (p. 349). Poems work with a sense of discovery and surprise: showing rather than telling. They might hint, tease, captivate, shout; they rarely explain. This arts-informed thesis draws on interdisciplinary reading and poetic play. Using critical autoethnographic writing and poetic inquiry, I inquire into dynamics of power and authority in family, church, and school. Drawing on feminist, activist perspectives, I explore the murky waters of memory, shame, trauma, grief, and silence as the underwaters of learning—mine and that of others. I inquire into a disquieted childhood and the challenges of adult literacy work. . Having grown up in small-town Ontario as the United Church minister’s daughter, I use the structure of the church service to inspire the form of my thesis. My inquiry borrows the language and movement of The Order of Service: Gathering, The Service of the Word, and Response. Underlying this work are questions about what it means to gather and respond, as well as a fundamental question about language: In what ways are words in our service and we in theirs? I examine how writing is entwined with power and authority, finding the writing process to be an embodied, spiritual quest(ioning). I grieve the death of my father, while releasing myself from the kind of authority he represented. The work of contemporary Canadian poet-essayists—including Lorri Neilsen Glenn, Maureen Scott Harris, Marlene NourbeSe Philip, and Don McKay—helps me think about how the craft of poetry engages particular kinds of knowing which respect and work with the unknown and the limitations of language. Poetry gives me cupped hands: these words for you. A gesture of holding, presenting, and releasing―embracing the relationality, attention, and astonishment inherent in learning.
Design of a Three-component Force Sensor for Meso-milling Applications
Keywords: analytical measurement model
cutting forces
finite element analysis
meso-milling
piezoelectric force sensor
signal processing

Accurate measurement of three-component cutting forces in meso-milling applications is imperative for the manufacturing of miniaturized complex three dimensional (3D) components that are in demand for a wide variety of industries. Considering the limitations of commercial force sensors in sensing resolution and frequency bandwidth for such measurement task, a novel three-component piezoelectric force sensor is designed in this thesis to address these issues. The novelty of the research is in the investigation into the use of "hard" piezoelectric ceramic materials for the sensing elements in order to achieve high sensing resolution and sufficient frequency bandwidth for the force sensor. An analytical measurement model is developed for analyzing sensor performance, namely sensing resolution and frequency bandwidth, while measuring the cutting forces in proposed meso-milling applications. Simulations with respect to the analytical measurement model demonstrate that the designed force sensor can be used for meso-milling applications. The overall measurement system architecture is also implemented in the thesis for processing the sensor output signals.
Beyond the Facade of Policy Implementation: Explaining Intractability and Occasional Success of Post-Communist Civil Service Reforms
Keywords: Civil service and public administration
Policy change
Policy implementation dynamics
Post-Communism
State

Building on the prolific literature of post-Communist change, cross-country comparisons and an in-depth analysis of the Russian case, this dissertation identifies the sources of regional and cross-sectoral disparities in civil service reform implementation after the Soviet Union collapse. The study draws attention to the role of contextual variables of policy change, such as political leadership and institutional capacities of the post-Communist governments. It argues that quality improvements in bureaucratic organization emerge as a result of reforms, which pursue genuine rather than symbolic goals to improve the culture and operation of state institutions. Civil service reforms, in particular, require meaningful efforts to build support among various policy actors (public sector organizations). Thus, in order to succeed, these efforts have to rely on a coherent reform strategy, which starts from a smaller issue, or a juncture of issues (incremental rather than comprehensive approach), followed by efforts to create effective policy control and appraisal mechanisms. The study revists several generations of policy implementation research in order to bridge the division between Western policy literature and the body of the post-Soviet scholarly work. The main contribution of this work consists of aggregating various factors and variables of public policy change into a few broad categories, such as domestic and global pressures, state capacity, policy leadership and others. The study situates the discussion in a broader framework of agency-strcuture debate, which shapes the dynamics of post-Communist transition. This approach combines a variety of qualitative methodological instruments to assess the impact of key variables on civil service reform implementation. The basic research method employed is representative case study (Russia), which relies on the study of primary and secondary sources, the method of process tracing and original interviews collected in Russia in 2010.
Understanding Perceptions of Health Following Hip Fracture: Using a Phenomenological Framework to Explore the Opinions of Patients, Caregivers, and Providers
Keywords: embodiment
fracture
hip
phenomenology
prognosis
qualitative research

The following study was guided by an overall research question: "What does it mean to have a hip fracture?". Using a phenomenological approach, I interviewed individuals who experienced a hip fracture, primary caregivers, and healthcare providers (HCPs) with the following objectives in mind: (1) to clarify meanings and conceptualization of prognosis for patients and caregivers following hip fracture as compared to HCPs treating them, (2) to enhance our understanding how these perceptions impact healthcare delivery at both ends of the spectrum, and (3) to provide a rationale for these perspectives. 25 participants participated in in-depth interviews that were audio-taped. The transcripts were coded separately for patients and for HCPs. This work was conducted without a-priori-hypotheses and through an inductive thematic analysis. Prognosis was the underlying phenomenon with four sub-themes identified for patients and caregivers: forecast, non-knowledge, sense of self-ownership, and enlargement. Four other sub-themes were identified for HCPs: interconnectedness, hip work, embodiment, and forecast. HCPs have the right to assign prognosis; however, patients' perceptions can be affected, not only through words, but also through the actions exerted by those in the healthcare profession. Viewing prognosis as a perspective (a Heideggerian concept) rather than a foreshadowing formed the main theoretical underpinning. Other theories informed this work: embodiment (Merleau-Ponty, 1962), body-self dialectic (Gadow, 1980), and body work and power (Twigg, 2011). Implications for HCPs consist in aiding the patient to develop insight on his or her symptoms and situation in addition to developing a therapeutic relationship that can effect clinical change. Implications for patients/caregivers emphasize using the patient's agency to enhance his or her quality of life. Future research in the area of prognosis will consider social context, while exploring variability, perceived value, and the impact on outcomes following discussion on hip fracture interventions between HCPs and patients/caregivers.