VictorJuiz/thesis huggingface dataset:
The Development of In-situ NMR Photoreactors and Analysis of Photochemical Processes in the Environment
Keywords: Dissolved Organic Matter
Environmental Photochemistry
In-situ
Kinetics
Nuclear Magnetic Resonance Spectroscopy
Photolysis

Photolysis is a major abiotic process in the environment. Current understanding of environmental photolytic processes is limited due to restricted information offered by conventional analytical techniques and lack of in-situ studies. In-situ nuclear magnetic resonance (NMR) photoreactors were developed to directly integrate light sources with NMR spectroscopy to probe into environmental photochemistry in a non-invasive manner. They were applied to a series of environmental systems including an atmospheric pollutant, crude oil extracts, groundwater (at natural abundance), and dissolve organic matter (DOM). Intermediates and degradation products were identified along with kinetic profiles of specific compounds in complex environmental mixtures. It was also shown to be a great non-invasive chromatographic tool to investigate the phototransformation of DOM. Also, two dimensional (2D) NMR experiments were used to characterize and quantify components in DOM. Overall, the work demonstrates that in-situ NMR spectroscopy is an important analytical tool in unraveling complex environmental photolytic processes.
Optically Imaging Forgetting in the Hippocampus
Keywords: CA1
calcium imaging
forgetting
hippocampus
neurogenesis

Ongoing neurogenesis in the hippocampus has been demonstrated to have a causal role in forgetting. It remains unclear how this forgetting is represented in the brain at the level of neuronal ensembles. This thesis attempts to answer this question by utilizing in vivo calcium imaging to record activity from hundreds of neurons in subfield CA1 while mice form and retrieve a contextual fear memory. We trained mice in a contextual fear conditioning task and tested memory expression before and after enhancing neurogenesis with voluntary exercise, or control conditions. Our preliminary findings indicate that memory formation is associated with a reduction in activity within CA1 and increased correlated activity among CA1 neurons. Enhancing neurogenesis after learning disrupted correlated activity during memory retrieval. Thus, decreased correlated activity in CA1 is concomitant with behavioral forgetting, suggesting that perturbed correlated activity resulting from circuit reorganization by hippocampal neurogenesis may underlie forgetting.
Continuous Theta Burst Stimulation of the Lateral Cerebellum Decreases Cognitive Cerebello-cerebral Functional Connectivity
Keywords: Cerebellum
fMRI
Parkinson's Disease
Resting State Networks
TMS

Previous studies using continuous theta burst stimulation (cTBS) applied to Crus I of the lateral cerebellum have demonstrated an inhibition of the contralateral motor cortex and connections in the cerebello-thalamo-cortical (CTC) pathway. The aim of this thesis was to determine the effects of lateral cerebellar cTBS on cognitive and motor cerebello-cerebral networks using resting state functional magnetic resonance imaging (rsfMRI). Functional connectivity between four cerebello-cerebral seed pairs constituting the cognitive network [Crus I – Brodmann area (BA) 7, Crus I – BA8, Crus I – BA9, Crus I – BA39] and one cerebello-cerebral seed pair constituting the motor network (Lobule V hand area – BA4 hand area) were measured before and after cTBS in 12 healthy subjects. As hypothesized, lateral cerebellar cTBS induced a significant decrease in functional connectivity within the cognitive network, while motor functional connectivity remained unaltered. These results provide further insight into the effects of cerebellar cTBS at the network level.
Traffic Microsimulation of Illegal On-street Parking in Downtown Toronto
Keywords: Downtown
Enforcement
Illegal
Microsimulation
Parking
Toronto

This research investigates the effect of vehicles parked illegally on-street on the performance of city streets during the AM rush hour in Downtown Toronto. Illegally parked vehicles effectively block a lane on a street, forcing traffic to merge onto a single lane. This problem might be inconvenient at uncongested times of day, but it creates significant delays to drivers, buses, streetcars and cyclists as roadways are already operating near or at capacity during the rush hour. A traffic microsimulation model that integrates illegal on-street parking into the Toronto Waterfront Network Paramics Model was generated to measure the effect of illegally parked vehicles on the flow of traffic. The study concluded that illegal on-street parking significantly increases link delays, link travel times, and reduces link flows and link speeds. The results imply that illegal on-street parking reduces the level of service of Downtown Toronto streets during the AM rush hour, and that existing traffic microsimulation models underestimate the vehicle travel times in the network for that period.
In Situ Treatment of 1,1,1-trichloroethane by Guar Gum-stabilized Zero Valent Iron Injection: A Field Study
Keywords: 1
1
1-trichloroethane
biodegradation
injection
in situ
remediation
zero valent iron

1,1,1-Trichloroethane (1,1,1-TCA) is one of the most commonly identified pollutants in contaminated soil and groundwater at hazardous waste sites. Hydraulic injection of granular zero valent iron (ZVI) stabilized with guar gum was performed at an active field site contaminated with chlorinated volatile organic compounds (cVOCs) including 1,1,1-TCA, 1,1-dichloroethane (1,1-DCA) and chloroethane (CA). Approximately 17,000 kg and 20,000 kg ZVI was injected and backfilled into the source zone. cVOC concentrations were monitored at the site before and after injection. Microcosm batch studies prepared using site groundwater indicated biodegradation occurs in the presence of ZVI and indigenous microbial communities were capable of biodegrading 1,1,1-TCA to CA. Reducing conditions were present nine months after injection. Concentrations were reduced from 37 to 94 percent. Quantification of groundwater samples for microbiological analyses demonstrated abiotic and biodegradation occurred following injection. This study demonstrates potential for application of guar gum-stabilized ZVI injection in the removal of 1,1,1-TCA.
Tending the Wilted Flower: The Role of Psychological Need Fulfillment in Treatment for Depression
Keywords: Cognitive Therapy
Pharmacotherapy
Psychological Needs
Self-Determination Theory

The present research integrated the principles of self-determination theory (e.g. Deci Ryan, 2000) with the cognitive mediation model of depression (e.g. Whisman, 1993). Participants with a SCID-IV diagnosis for major depressive disorder were randomly assigned to 16 weeks of cognitive therapy or anti-depressant medication. They also completed indices of depression severity, neuroticism, and psychological need fulfillment, at four assessment points (pre-treatment, week 4, week 8, and week 16). Psychological need fulfillment increased over the course of treatment and was negatively correlated with depression severity. Increases in psychological need fulfillment predicted decreases in depression severity over and above the effects of time, neuroticism, and negative cognitions. The temporal association between changes in psychological need fulfillment was bidirectional, and significantly more pronounced in the cognitive therapy condition. The association between changes in psychological need fulfillment and changes in depression severity was not mediated by reduced negative cognitions.
Imaging the Development of Sex Differences in the Brain
Keywords: Brain
Development
Sex

Sex differences are pervasive in the brain and affect many behaviours and disorders, such as psychiatric disorders. However, current studies investigating sex differences in neuroanatomy are primarily cross- sectional, focal examinations. This thesis aims to study sex differences in the whole brain, as they develop, beginning in early life. Male and female C57BL/6 mice were longitudinally scanned at nine time points with in vivo manganese enhanced magnetic resonance imaging. An investigation of the three canonical sex differences in the brain reveal different developmental trajectories amongst areas. Next, a linear mixed effects model centred at each time point revealed widespread patterns of larger areas in males predominating in early life, while larger areas in females predominate in post-pubertal life. Finally, k-means clustering of sexually dimorphic development across life reveals an area in the cortex larger in females, and the coordinated growth of a sexually dimorphic network of structures related to vomeronasal circuitry.
Detection of Placental Pathology Based on Umbilical Artery Wave Mechanics
Keywords: intrauterine growth restriction
placenta
pulsatile flow
reflected wave
ultrasound
wave decomposition

Abnormally pulsatile umbilical artery (UA) Doppler waveforms (characterized through the UA pulsatility index) are widely used as a screening tool to detect intrauterine growth restriction (IUGR) due to placental disease. However, the sensitivity of UA Doppler in detecting IUGR is quite poor. One explanation for this is that the pulsatility in the UA consists of intermixed cardiac and placental signals. Here, we overcome this limitation with a new ultrasound approach in which the observed UA Doppler waveforms are decomposed into forward propagating waves (developed by the fetal heart) and reverse propagating waves reflected back from the placental circulation. A proof-of -principle experiment was conducted in mice. Results show that the patterns of reflected waves in the UA parallel the variations in the downstream fetoplacental morphology and are more sensitive to these variations than the UA pulsatility index. Thus, this methodology has the potential to improve the detection of placental-mediated IUGR.
Ziisabaakodakaan: The Place Where Sugar is Made
Keywords: Anishinaabe
Anishinaabe Gkendaasowin
Maple Syrup
Traditional Ecological Knowledge
Ziisabaakodakaan

One of the most pressing environmental challenges facing people around the world is climate change. Climate change scientists have pointed out that in 100 years the maple trees will no longer produce sap for making maple syrup. Sugar Maple trees (Ninaatigoog) are not adapting to the warmer climate. There are cultural practices of the Anishinabek that revolve around participating and producing natural foods such as Ziiwaagamide that are dependent on the environment. This thesis looks to address the following questions through research conducted with a family based practice of the Ziisabaakodakaan in Wiigwaaskinigaa. What then will be the social and cultural impacts of the disappearance of Ziisabaakodakaan practices on Anishinabek well-being? How have changes of Ziisabaakodakaan practices influenced Anishinaabemowin? How can Anishinaabe Gkendaasowin assist Anishinabek in coping with ecological changes due to climate change? Anishinaabe knowledge is complex and vast and it gathered from a lifetime of observation and engagement on the land. The research findings suggest that Anishinaabe elders are witnessing, the poor health of Sugar Maple trees and this may influence cultural and community resiliency and thus adaptation to climate change.
Electrophilic Phosphenium and Phosphonium Cations: Synthesis and Reactivity of Perfluoro- & Perchloroaryl Phosphorus Systems
Keywords: Air stable
Catalysis
FLP
Lewis acid
Phosphenium
Phosphonium

Electrophilic phosphonium cations (EPCs) have shown great promise in Lewis acid catalysis typically only mediated by transition metals. The application of EPCs as catalysts has been limited by their air and moisture intolerance, leading to catalyst degradation. Bulkier perchlorinated-aryl substituents (C6Cl5) have been previously incorporated into electrophilic boranes yielding compounds with increased stability to air and moisture as compared with their perfluorinated-aryl (C6F5) substituted counterparts. In this work, the synthesis of C6Cl5-substituted EPCs is described and the Lewis acidity and air stability of these compounds is tested, demonstrating that C6Cl5 incorporation is a viable approach to air-stability. Moreover, the capacity of some of these EPCs to act as frustrated Lewis pairs (FLPs) with weak or strong Lewis bases towards the activation of H2 or CO2 is probed. The development of a highly electrophilic N heterocyclic carbene (NHC)-stabilized phosphenium cation and its performance as a Lewis acid catalyst is also described.
Tailoring the Bending Stiffness of Elastomeric Dual-matrix Composites
Keywords: Anticlastic
Composites
Dual-matrix
Morphing

Aircraft structural design is becoming increasingly oriented towards multifunctional structures, which are capable of supporting large loads while exhibiting additional functional capabilities; morphing is an example. Composite materials provide the perfect testbed for such morphing technologies. Dual-matrix composites are being investigated by a number of researchers, primarily for use in deployable structures. This work investigates a more load-intensive application in aircraft cabin interiors. A morphing composite meal-tray table prototype is fabricated and tested. The macromechanics of dual-matrix laminates are investigated, with the focus being the tailoring of the bending stiffness of such laminates. The cross-section anticlastic deflections of +-45 degree layups, due to high Poisson ratios, are shown to increase the bending stiffness of the laminate, resulting from an increased second moment of area. A predictive model for bending stiffness is constructed, compared with FEA and experiments, and its limitations in predicting woven-fabric composite behaviour are discussed.
An Exploration of Adverse Experiences in Mindfulness Meditation
Keywords: Adverse
Experiences
Meditation
Mindfulness
Negative
Qualitative

Although the benefits of mindfulness continue to be affirmed by empirical evidence, an emerging area of research has begun to document its potential for eliciting adverse psychological and physical effects. However, the psychological, social, cultural, and historical variables that give rise to these experiences and the individualâ s ability to successfully integrate them remain unclear. The present study addressed this increasingly relevant gap in the literature by conducting exploratory in-depth inter-views with eight participants who experienced adverse events brought on by their engagement in mindfulness. The interviews explored, 1) participantsâ experience of adverse events, 2) the contextual factors surrounding these experiences, and 3) how they coped with these experiences. The data was analyzed using a grounded theory approach to explore the common themes that arise from these participantsâ experiences. The findings provide a better understanding of experiences of distress precipitated by mindfulness meditative practices and how counsellors can support practitioners in coping with adverse events.
Interference-facilitated Photon Pair Separation in Integrated Quantum Circuits
Keywords: couplers
integrated
interference
photonics
photons
quantum

The implications of integrated coupler dispersion for interference-facilitated photon pair separation (IFPS) are explored. As the photon pair non-degeneracy is varied, near-perfect separation fidelities can be preserved by anti-symmetry in the central wavelength splitting ratios, even though the coupler response may differ greatly from that of an ideal 50:50 splitter. Active coupler tuning can assist in achieving this anti-symmetry. Coupler dispersion is shown to produce new features such as novel interference visibility behaviour and entanglement-sensitive performance. When only a single input path is utilized, tailoring of spectral correlations in the post-selected output state becomes possible. A source of path-entangled bunched states based on the Bragg reflection waveguide (BRW) platform is designed for use in IFPS experiments, and a roadmap for testing IFPS behaviour is presented. This work informs the design and characterization of quantum circuits for achieving universal photon pair separation for states with highly tunable spectral and polarization properties.
Removal of Particulate Fines from Organic Solvents Using Water as Collector Droplets
Keywords: bridge formation
capture efficiency
collector droplets
Microfluidic aspiration
oil-sands
Particulate removal

A PDMS-based microfluidic aspiration device was developed to carry out a systematic study of the capture of particles suspended in an organic liquid by using water as collector droplets. By applying a suitably strong negative pressure at one of the inputs relative to the port delivering the particles, a water drop was trapped at the constriction and then head-on and glancing collisions were implemented between particles and a water drop. The capture efficiency of particles was determined by a multi-particle tracking code developed in MATLAB. Simulations were performed to obtain a measure of particle interaction time with the drop surface. It was observed that at low capillary numbers O (10^-4 ) , hydrodynamic drainage was not the rate limiting step for particle (O(10 um) ) capture. The possibility of other hydrodynamic or thermodynamic processes such as bridge formation and contact line motion in particle capture, are discussed. The relationship between particle capture efficiency and velocity and radius of the collector droplets was mapped out. This work aims to provide insight into the feasibility of the use of an aqueous phase for collecting and separating fines from bitumen- solvent mixture by obtaining statistical data for particle - drop impingement process. Current methods for the removal of particulates such as centrifugation and solvent evaporation are energy-intensive, and carry potential emission hazards. Removal of fines using a water drop is much more energy efficient than the traditional methods. The device from this study will lead to fundamental investigations that will provide design guidelines for a mixer for effective particle removal in the oil sands industry.
CAD Tools and Architectures for Improved FPGA Interconnect
Keywords: Architectures
CAD Tools
FPGA
Interconnect
Metrics

The FPGA routing architecture consists of routing wires and programmable switches which together account for a significant fraction of the fabric delay and area, making interconnect optimization a key topic for FPGA architects. Moreover, the rapid growth of wire RC delay with process scaling has increased the importance of efficiently using the different layers available in the metal stack. We enhance architecture models and tools to allow exploration of interconnect topologies that use a mix of wire types connected in complex ways. We use our enhancements to investigate interconnect hierarchies that take advantage of routing on the upper layers of the metal stack, and show 5-13\% delay improvements compared to previously-published routing topologies. To promote insight and fast routing architecture design iteration, we develop Wotan, an analytic tool to estimate interconnect routability without benchmarks; we show that Wotan is in good agreement with the full VPR CAD flow while requiring much less compute effort.
Molecular Dynamics Studies of Load Transfer in Nanocomposites Reinforced by Defective Carbon Nanotube
Keywords: Buckling
Carbon Nanotube
Defect
Interfacial Shear Strength
Molecular Dynamics
Nanocomposite

This study is concerned with the development of relatively more accurate numerical simulations than those adopted in the literature to investigate the considerable discrepancies between experimental findings and theoretical predictions of the interfacial shear strength (ISS) of nano-reinforced thermoset composites. In this work, extensive molecular dynamics (MD) simulations were conducted to examine the ISS and buckling behavior of carbon nanotube (CNT)-reinforced epoxy composites. We considered different types of defects such as vacancy, Stone-Wales defect, carbon adatom, and phenyl functional group. Pull-out and compressive load simulations were performed via the consistent valence forcefield (CVFF) on a representative volume element comprising a single-walled CNT embedded in an epoxy matrix. Our results revealed that different defects can, to some extent, either enhance or degrade the properties of nanocomposites. The findings will assist in improving our understanding of the toughening/weakening mechanisms associated with nanoscopic reinforcement and the load transfer capability in epoxy-based nanocomposites.
A Meta-analytic Review of Selected Adverse Drug Events (ADEs) of Long-term Prescription Opioids for Chronic Non-cancer Pain (CNCP)
Keywords: Adverse Drug Events
Adverse Drug Reactions
Chronic Non-Cancer Pain
Meta-analysis
Opioids
Prescription medication

Background: Opioids are considered one of the most effective analgesics. However, knowledge on opioid adverse drug events (ADEs) is limited and the current state of the literature has remained elusive. Purpose: This meta-analytic review focused on five selected adverse drug events (SADEs) (misuse, abuse, addiction, overdose, and death) of prescription opioids to surmise the overall state of this literature and evaluate quality of reporting and risk of bias. Methods: Studies were acquired from research databases, including: MEDLINE, EMBASE, CINAHL, PsycINFO, CENTRAL, and Business Source Premier. Results: Ninety studies satisfied inclusion and exclusion criteria and were included. Quality of reporting of SADEs, determined via McHarm, risk of bias, assessed using a Cochrane guideline, and overall event rates of SADEs are reported. Conclusion: Results revealed that quality of reporting was poor and risk of bias was high. Findings suggest that quality of reporting of SADEs and risk of bias must be improved.
Identification of Novel Substrates of the Ubiquitin E3 Ligase RNF126 and Characterization of its Role in Lipid Droplet Homeostasis
Keywords: BioID
Lipid droplet
p97
RNF126
ubiquitin
UBXD8

Ubiquitin E3 ligases confer specificity by recognizing target substrates and mediating the final step of the ubiquitination process. Despite this critical role, our understanding of their physiological partners and biological functions remains limited. Here we use a proximity-based protein screen called BioID to explore novel interacting proteins and substrates of the ubiquitin E3 ligase RNF126. We demonstrate that RNF126 can associate with p97 as well as its co-factors UBXD1 and UBXD8 and show that UBXD1 and UBXD8 are bonafide substrates of RNF126. To determine a functional role, we explored the role of RNF126 in UBXD8 mediated functions. We found that stable knockdown of RNF126 in HeLa cells results in smaller LDs following oleate stimulation and that this is due to defective expansion. Together, this work demonstrates the successful use of BioID to identify substrates of ubiquitin E3 ligases and furthers our understanding of the role of ubiquitin in LD biology.
Using Computers to Assess Cognition in MS: Improving Tried and Tested Indices to Capture Real World Challenges
Keywords: Cognition
Multiple Sclerosis

Cognitive dysfunction is common in people with multiple sclerosis (MS) and causes limitation in activities of daily living. Current cognitive screens are limited by time and cost requirements and they lack ecological validity. The objective of the present study was to develop an improved method of cognitive assessment using real-world distracters. A sample of 102 MS subjects and 69 healthy controls underwent testing with a modified computerized Symbol Digit Modalities Test (c-SDMT) and the Minimal Assessment of Cognitive Functioning in MS battery. Half completed the distracter c-SDMT and half non-distracter. Relative to the traditional SDMT, significantly more MS subjects were impaired on the distracter c-SDMT, but not on the non-distracter test. The distracter test had a sensitivity of 82% and specificity of 80% in detecting global cognitive impairment. The incorporation of distracters improves the sensitivity of the c-SDMT and offers a quick and easy method for detecting cognitive dysfunction.