VictorJuiz/thesis huggingface dataset:
Quantitatively Assessing the Role of Higher Education in Global Sustainability
Keywords: Environmentally extended input output modeling
Industrial ecology
Integrated assessment modeling
Sustainability
Sustainability in higher education
Sustainable development

Three analytical methods are used to examine three primary questions to address an observed scarcity of literature that quantitatively and empirically assesses the role of higher education in global sustainability. Linear regression is used to assess correlations between institutional environmental impacts and campus initiatives; environmentally-extended input-output analysis is used to assess the global operational footprint of higher education; and the IPAT framework and integrated assessment modeling are used to assess the influence of higher education on global systems. Despite limitations - most notably that current data availability impedes the isolation of higher education from education more broadly - the results support the following conclusions. 1) There are no meaningful correlations between campus sustainability initiatives and direct environmental impacts, though many initiatives are admittedly not aimed at reducing direct impacts. 2) The fraction of overall human ecological footprint attributable to higher education is too minor for its management to play a transformative role in achieving global sustainability, but managing it to lead by example could be more so. 3) Higher education influences global sustainability most significantly by contributing to the education driven fertility mechanism, and possibly by promoting technological change, though the magnitude and exact mechanisms of the latter relationship are uncertain.
Development and Characterization of an Extractive-based Bio-epoxy Resin from Beetle-infested Lodgepole Pine (Pinus contorta var. latifolia) Bark
Keywords: Bio-based epoxy
Bisphenol a
Curing
Epichlorohydrin
Nanocellulose fibres
Tree bark

Deriving chemicals from renewable feedstock has become a necessity to reduce dependency on petroleum, which release carbon dioxide when burned and aggravate the global warming and ocean acidification. This work offers a potential alternative - bark extractives based epoxy resin - to petro-based conventional epoxy. Our results showed successful epoxidation of bark extractives after reaction with epichlorohydrin. The newly synthesized epoxy (E-epoxy) can replace 50% of petroleum-based epoxy (P-epoxy) and the blend system displayed thermal stability and tensile strength comparable to neat P-epoxy, which demonstrates a great promise in using bark extractives as a substitute for bisphenol A (BPA). An examination of reaction parameters showed that the E-epoxy monomer can be synthesized with high yield and reactivity using spray-dried extractives as substrates, a dioxane/water combination as solvent, and tetrabutylammonium hydroxide as the ring-opening catalyst. An examination of numerical parameters showed the maximum yield with minimum epoxy equivalent weight was achieved after 4.5 hours reaction time with sodium hydroxide to hydroxyl value molar ratio of 3.4 at a reaction temperature of 80 °C. The thermal properties of E-epoxy were studied using TGA, FTIR, and Py-GC/MS, and a new thermal degradation mechanism was proposed. Additionally, nanocellulose fibres (NCFs) were incorporated to enhance E-epoxy’s mechanical performance. Based on an adjusted curing schedule, an E-epoxy/P-epoxy/NCFs composite with high strength, ductility, thermal stability, and sustainability was developed. With 10% E-epoxy, the toughness of neat epoxy resins improved 84 %; after incorporating NCFs, the tensile strength and modulus of composites increased approximately two- and four-fold, respectively. The maximum degradation peak of the composites was 24 °C higher than for neat epoxy resins. Overall, bark extractives exhibit great promise to replace petro-based BPA; incorporating NCFs into E-epoxy/P-epoxy blending system is an effective method to develop a strong and sustainable bio-nanocomposite.
From Farm to Firm: Canadian Tobacco c. 1860-1950
Keywords: Environmental History
History of Capitalism
Modernity and Expertise
Rural History
Social History
Tobacco

This dissertation examines the transformation of Canadian tobacco cultivation from its roots in local markets and personal consumption to a multi-million dollar concern featuring corporate plantations and multi-acre tobacco farms. It focuses on how tools of agricultural modernization— abstraction, expertise, experimentation, fertilization, government policy, land ownership, and marketing associations—produced unanticipated challenges that complicated any linear development of tobacco cultivation. The dissertation places everyday experiences of tobacco cultivation alongside the broader sweep of agricultural modernization to argue that the deployment of the tools of modernization produced new limitations over expert control of the environment and markets. The dissertation considers cultivation in Ontario, Quebec, and British Columbia, and includes moments of rapid expansion, such as the rise of the flue-cured tobacco “New Belt” in Norfolk and Elgin counties during the late 1920s, and instances of gradual failure, like efforts to encourage commercial tobacco in the Okanagan and Sumas Valley regions of B.C. Various farmer organizations and cooperatives feature in the exploration of the responses and initiative of farmers to the evolving requirements of tobacco companies for their raw material. The role of both federal and provincial government officials also receives considerable attention, as they promoted modern, commercial-orientated tobacco cultivation while attempting to remain an intermediary force between farmers and corporations. The records of the federal Tobacco Division and various government investigations collectively demonstrate that this position was not always tenable, as the government would find itself drawn into fierce disputes over farm prices and the monopolistic character of Imperial Tobacco. These disputes illustrate how modernization produced instabilities even as it improved farm revenues. Collectively, this dissertation’s consideration of farm work, environmental change, and markets demonstrate how the possibilities of agricultural innovation produced their own tensions and limitations that are fundamental to understanding the lived experience of capitalism and modernization in rural Canada.
Ultrasound-mediated S100A6 Gene Therapy Ameliorates Myocardial Ischemia/Reperfusion (I/R) Injury
Keywords: Myocardial Ischemia/Reperfusion Injury
S100A6
Ultrasound-Mediated Gene Delivery

Abstract New therapies targeting myocardial ischemia/reperfusion (I/R) injury are key to averting the adverse remodeling process and subsequent heart failure (HF) post myocardial infarction (MI). S100A6 is a member of the superfamily of EF-hand Ca2+-binding proteins that modulate many key pathways involved in myocardial I/R injury and adverse left ventricular remodeling including cardiomyocyte apoptosis and hypertrophy. Methods and Results S100A6 overexpression improved calcium transients and protected against apoptosis induced by hypoxia-reoxygenation via enhanced calcineurin activity, while knockdown of S100A6 had detrimental effects in rat neonatal cardiomyocytes, in vitro. Moreover, S100A6 overexpressing HUVECs show enhanced tube formation and augmented migration as markers of angiogenesis in vitro. In a rat model of myocardial I/R, S100A6 expression is up-regulated in the infarct and peri-infarct regions of the left ventricle (LV) following myocardial I/R injury but occurs simultaneous or just after the peak of apoptosis and LV functional deterioration. Ultrasound-targeted microbubble destruction (UTMD) delivery of hS100A6-plasmid prior to I/R yields a survival advantage, improves LV systolic function and myocardial perfusion, attenuates cardiac hypertrophy and reduces infarct size through prevention of apoptosis and necrosis and enhancement of calcium handing post myocardial I/R injury, in vivo. Finally, UTMD delivery of hS100A6-minicircle (MC) immediately after I/R injury yields similar therapeutic benefits on reduction of infarct size, improved LV systolic function and myocardial perfusion, as compared to control and empty minicircle UTMD. Conclusion The present study is the first to demonstrate the therapeutic benefits of targeted hS100A6 gene delivery in the setting of cardiac I/R injury, resulting in a significant improvement in LV function, a reduction in infarct size and prevention of adverse LV remodeling. Gene therapy by UTMD of S100A6 holds promise as adjunctive therapy to primary percutaneous coronary intervention to help ameliorate ischemia/reperfusion injury.
A New Class of Modular Multilevel DC/DC Converters for HVDC Systems
Keywords: Control
Converters
DC/DC Conversion
HVDC Transmission
Modeling
Power Electronics

This thesis develops a new class of modular multilevel dc/dc converters, termed the DC-MMC, that can be deployed to interconnect HVDC networks of different or similar voltage levels. Advanced operating features include buck/boost functionality and bidirectional dc fault blocking analogous to a dc circuit breaker. A key advantage of the DC-MMC is that it eliminates the full-rated intermediate ac conversion stage traditionally employed by modular multilevel converter (MMC) based two-stage dc/dc converters, i.e. dc/ac-ac/dc conversion. This is enabled by a new single-stage bidirectional dc/dc conversion process that requires only a fraction of the dc power throughput to be internally circulated as ac power. In comparison to state-of-the-art MMC based two-stage dc/dc conversion, the DC-MMC enables up to a 50\% reduction in total semiconductor expenditure and total capacitive energy storage requirements, translating to commensurate savings in converter capital cost and operating losses. The DC-MMC principle of operation is validated via simulation of a comprehensive switched model in PLECS. To gain deeper insight into DC-MMC dynamics and internal power transfer mechanisms, this thesis exploits the use of dynamic phasors to accommodate the multiple frequency components that exist at steady-state. Large-signal and small-signal time-invariant dynamic phasor models are derived. The large-signal phasor model enables: 1) solving for the full steady-state solution of the DC-MMC under arbitrary loading, and 2) evaluation of DC-MMC open-loop stability via eigenvalue analysis. Based on the small-signal phasor model, a dynamic controller suitable for dc network applications is proposed that regulates output power while ensuring individual capacitor voltages remain balanced. The developed analytical models and dynamic controls are validated by simulation. Bidirectional dc fault blocking capability is also confirmed by simulation. Experimental results for a 4 kW prototype validate the single-stage dc/dc conversion process for both step-down and step-up operating modes.
A Mechanism to Explain Repressive Epigenetic Memory Inheritance
Keywords: aniPOND
Cell Cycle
CHAF1A
DNA Replication
Epigenetics
PRC2

Epigenetics describes heritable changes in gene expression that do not affect DNA sequence. Methylation of the histone tail can be associated with both gene activation and silencing. The Polycomb Repressive Complex 2 (PRC2) catalyzes the tri-methylation of H3K27 (H3K27me3) to create a repressive chromatin domain. A major question in the field concerns how epigenetic marks are transferred during DNA synthesis as these post-translational modifications cannot be duplicated by the replication machinery. A recent publication suggests a "self-maintenance" model of inheritance in which PRC2 travels with the replication fork through out S phase, coupling H3K27me3 transmission to replication fork progression. However, the exact mechanism and timing of PRC2 recruitment remains unknown. Our lab studies the regulation of interferon-Îł (IFNÎł) stimulated genes (ISGs) and our data indicate that PRC2 represses many ISGs. Furthermore, in an RNAi screen, we discovered that the histone chaperone CHAF1A, which facilitates nucleosome formation at replication forks, is required for maintenance of H3K27me3 marks and ISGs repression by PRC2. My data showed that PRC2 in fact localized to stable discrete foci during S phase and these foci coincide with replication forks primarily during early/mid S phase (S2/S3). Strikingly, with aniPOND, I found that H3K27 trimethylation also occurs during S2/S3. These observations argue against the current model of H3K27me3 inheritance. Knocking down CHAF1A rescues expression of many repressed PRC2 targets and disrupted the distribution of H3K27me3 without affecting the bulk levels. Interestingly, DNMT1 and DNA methylation patterns are also delocalized without CHAF1A, suggesting cross talk between the mechanisms that maintain DNA methylation and H3K27me3 during S phase. Collectively, results from this study furthered our current understanding regarding the timing of H3K27me3 transmission during S phase, and implicated a major role for CHAF1A in the propagation of repressive epigenetic memory by PRC2.
Neurochemical Substrates of Asymmetrical Sleep in the Fur Seal
Keywords: acetylcholine
asymmetrical sleep
cortical activation
fur seal
microdialysis
unihemispheric sleep

Several neuronal systems contribute to the generation and maintenance of sleep and waking. Knowledge pertaining to the neurotransmitters involved in sleep-wake regulation has been derived primarily from species that display bilaterally symmetric EEG states (e.g. cats, dogs, rats, and mice). However, these studies do not indicate which aspects of sleep these neurotransmitters are specifically linked to. Fur seals display both bilateral (BSWS) and asymmetrical sleep slow-wave sleep (ASWS); this unusual sleeping pattern provides a unique opportunity to determine which of the many physiological and neurochemical changes seen bilaterally in terrestrial mammals are linked to the cortical EEG changes and which may be linked to the motor and/or autonomic aspects of sleep. In studying this remarkable feature of the fur seal, we can dissociate the thalamocortical EEG activity in each hemisphere from aspects of behavioural state and study each independently as they relate to neurotransmitter release. The overall aim of my thesis was to examine, simultaneously in both hemispheres, the release of key neurotransmitters in the cortex across the sleep-wake cycle in the northern fur seal, and to specifically compare levels during BSWS and ASWS. In vivo microdialysis and high-performance liquid chromatography were used to monitor the release of neurotransmitters during polygraphically defined states. Neurotransmitters previously thought to contribute equally to the waking state, actually behave quite differently in a brain that is half awake and half asleep. Cortical acetylcholine (ACh) release was highly lateralized during ASWS, with greater release in the activated hemisphere, whereas cortical serotonin (5-HT), noradrenaline (NA), and histamine (HA) were symmetrically released during ASWS. Of the arousal systems studied so far, only ACh is involved in the lateralized cortical EEG activation manifested in asymmetric sleep. Bilaterally symmetric levels of the monoaminergic transmitters studied to date are compatible with interhemispheric EEG asymmetry. Findings suggest distinct functional roles for ACh, 5-HT, NA, and HA in the regulation of wakefulness, with respect to cortical activation and behavioural arousal.
Experimental Study of Turbulent Premixed Combustion in V-shaped Flames
Keywords: Fluid Mechanics
Turbulent Premixed Combustion

Characteristics of turbulent premixed flames were investigated experimentally. The investigations were performed using Mie scattering, Particle Image Velocimetry, Rayleigh scattering, and broad-band luminosity imaging techniques. Methane-air flames associated with a relatively wide range of turbulence intensities, fuel-air equivalence ratios, and mean bulk flow velocities were investigated. For a relatively moderate value of turbulence intensity, a new concept is introduced and utilized to provide a detailed description associated with interaction of turbulent flow and flame front. The concept pertains to reactants velocity estimated at the vicinity of the flame front and is referred to as the edge velocity. Specifically, it is shown that fluctuations of the flame front position are induced by fluctuations of the edge velocity. For a relatively wide range of turbulence intensity, several characteristics of turbulent premixed flames, namely, front topology, brush thickness, surface density, and consumption speeds are investigated. For the first time, several flame front structures are identified and studied. It is shown that, due to formation of these front structures, the regime of turbulent premixed combustion transitions from the regime of counter-gradient diffusion to that of the gradient diffusion. In addition to these, a comprehensive study is performed to investigate influence of flame configuration on several flame front characteristics. It is obtained that, although changing the flame configuration influences several flame characteristics, the trends associated with the effects of governing parameters on the characteristics are nearly independent of the flame configuration.
Tripping the Flow past a Circular Cylinder: Use of Multiple Large-Scale Spanwise Protrusions
Keywords: Cylinder flow
Flow control
protrusion devices
Tripwires
von Karman shedding
Vortex induced vibrations

An experimental study is carried out to investigate if the collective influence of multiple spanwise tripwires fitted on a circular cylinder in subcritical flow can be correlated to the knowledge accumulated by previous studies on the influence of only one tripwire on its own. In an effort to explore this, the vortex shedding frequency, characteristics of the near wake flow topology, shear layer separation behaviour, and the strength and coherence of the von Kármán vortex shedding were determined for cylinders fitted with one, two, three, four, five, and eighteen spanwise tripwires using measurement techniques such as Particle Image Velocimetry (PIV), Constant Temperature Anemometry (CTA), and Hydrogen Bubble Flow Visualization. The single-wire tripping was selected as the baseline case because it is the simplest form of tripping, and much is known about its effects from previous studies. Based upon the effective range of angles from θt to θb, defined by Nebres and Batill (1992), four scenarios could be identified for a multi-wire fitted cylinder. If none of the tripwires of the multi-wire fitted cylinder were within this range, the cylinder was analogous to a smooth cylinder. If only one tripwire was within the θt to θb range, the flow around the multiple-wire fitted cylinder can be exactly inferred from the flow around the single-wire fitted cylinder. If two tripwires of the multi-wire fitted cylinder were within the θt to θb range, the Strouhal number could be inferred by considering an accumulative influence of both of the tripwires. The fundamental angles such as the first and the second critical angles could also be found for the multi-wire-fitted cases by considering the fundamental angles of the single-wire-fitted case. Here, the total amount of fluid available to be entrained in the shear layers needs to be considered to predict the near wake flow behaviour; which may cause a delay in the location of the first critical angle (θc1) in certain special circumstances. For the cases considered in the present study, when more than two tripwires are within the θt to θb range, the Strouhal number of the multi-wire fitted cylinders is similar to that of the smooth cylinder. In the last scenario, the whole cylindrical configuration needs to be considered at once rather than using the data from a single-wire fitted-cylinder to infer the properties of the flow.
Health Literate Discharge Practices in Ontario Hospitals
Keywords: care transitions
health literacy
hospital discharge
hospitals

Health literate discharge practices meet the health literacy needs of patients and families at the time of hospital discharge. This dissertation used a mixed methods, sequential design to gain insight into the use of these practices in Ontario hospitals. The Health Literate Care Model was used to guide the first two studies. The first study used a Delphi panel to find the best indicators of health literate discharge practices, based on the indicators of Project RED (Re-Engineered Discharge). This led to the development of 36 indicators, which were contextualized to Ontario, and were used to create an organizational survey tool. This survey was administered to 143 hospitals in Ontario. There were 99 participants from 79 hospitals (participation rate 55%). Exploratory factor analysis was done and reliability of the survey was established. The third study used organizational learning theory to examine how acute care hospitals take on health literate discharge practices by interviewing managers, educators and front-line staff in 10 hospitals that participated in the survey. In the fourth study, multiple regression analysis was used to examine the relationship between organizational characteristics and use of health literate discharge practices, as determined by the survey results. Smaller hospital size was associated with greater use, and survey scores were found to be highest in the North region. A significant interaction was found between size and location. The development of the organizational survey tool could be used by researchers, hospitals and policy makers to measure and monitor the use of health literate discharge practices in Ontario hospitals. The results of the qualitative study offer insights into how organizational learning is used by hospital managers and leaders to adopt health literate discharge practices.
The Use of Susceptibility Effects for Tracking and Encoding in MR-guided Interventional Procedures
Keywords: Interventions
Magnetic susceptibility
MRI

Magnetic Resonance Imaging (MRI) provides volumetric imaging with superior soft tissue contrast and is now standard-of-care for many diagnostic applications. A growing area is the use of MRI for minimally invasive procedures (a.k.a interventions) such as MRI-guided biopsy. In this thesis, the target procedure was placement of a drainage catheter in the upper urinary tract, the technical term for which is nephrostomy. Tracking and visualization of the interventional devices is crucial in achieving a successful outcome of the procedure. This thesis is a study of MRI methodologies to track interventional devices in MRI-guided procedures. A particular focus was the application of magnetic materials used to perturb the main magnetic field, an effect that was used to develop tools and techniques for tracking devices and making images at the device tip. The experiments in Chapter 2 led to the development of a new technique using spectrally selective excitation, which is capable of simultaneously measuring the location and orientation of an interventional device. In Chapter 3, a new mechanism for tracking is proposed based on the magneto-optical effect in nickel nanoparticles, where fiber optics were used to deliver photons from a near infrared (NIR) laser. This development is intended to enable the incorporation of small tracking devices attached to the interventional tools, which can be pulsed on and off using a laser waveform. In Chapter 4, magnetic materials have been used to generate spatial encoding fields at the tip of a device, to generate endoscopic MR images. These results have contributed to the development of tracking devices and to the advancement of MRI acquisition methods for passive tracking in MR-guided procedures, with an outlook towards clinical application in nephrostomy and beyond.