VictorJuiz/thesis huggingface dataset:
Approach-avoidance Conflict for Sucrose and Footshock Pairing in Cocaine-sensitized Rats

Repeated administration of psychostimulant drugs induces a long-term state of sensitization in the mesolimbic dopamine system. This hyperdopaminergic state is associated with enhanced reward-seeking behaviors. Such aberration of incentive motivational processing is suggested to facilitate the initiation and maintenance of compulsive drug-taking behaviors. A defining characteristic of addiction is the persistence to pursue drug reinforcement despite negative consequences associated with administration. Thus, it is likely that addicts frequently experience states of motivational conflict to both seek and avoid the drug. The present study investigated the effects of repeated cocaine exposure on goal-seeking behaviors in rats, utilizing conflict paradigms wherein positive and negative incentive motivations were simultaneously evoked. Here it was shown that cocaine-experienced rats displayed both enhanced approach and avoidance behaviors, depending upon the conditions put forth in each paradigm. The results contribute to elucidating the consequences of drug administration upon basic motivational processes that may influence compulsive drug-taking behaviors.

Keywords: incentive motivation
addiction
dopamine
cocaine
sensitization
approach-avoidance
Advisor: Ito, Rutsuko
Erb, Suzanne
Multimodal Targets in Speech Production: Acoustic, Articulatory and Dynamic Eevidence from Formant Perturbation

This thesis presents evidence from a formant perturbation experiment which supports the hypothesis that speech targets are multimodal. A real-time auditory feedback perturbation is used to gradually shift English speakers' formants from the vowel /E/ towards /I/. Most speakers compensate at the level of acoustics, adjusting their production towards /ae/ such that they hear themselves producing the correct vowel. Subjects' articulation is tracked with electromagnetic-articulography. The articulatory data shows that subjects tend to produce marginal /E/s at the level of articulation - remaining within the normal articulatory bounds for that vowel, while adjusting the position of individual articulators to a sufficient extent to create an acoustic compensation to the perturbation. The higher-order relationship between speed and curvature is shown to differ across different vowel phonemes. However, this measure remains constant under formant perturbation. These findings are argued to show that phonemic targets are multi-modal, having acoustical, kinematic, and dynamic components.

Keywords: speech motor control
auditory feedback
formant perturbation
articulography
Advisor: Bressmann, Tim
Non-contact Measurement of Dynamic Belt Span Tension in Automotive FEAD Systems

The proposed tension measurement method focuses on measurement of tension in a single belt span of the multi-pulley Front End Accessory Drive (FEAD) system. The mean belt span tension is calculated from the measured belt span natural vibration frequency. The oscillation belt span tension is calculated from the measured belt span transverse displacement. The dynamic belt span tension is calculated using the mean and oscillation tensions, belt span support pulley rotations, and belt slip, where the slip equation is based on Euler's equation. The proposed tension measurement method is validated using an experimental testing FEAD system which consists of a five pulley system and an automatic tensioner arm. Non-contact sensors are used to prevent disruption of the typical system behaviour. Testing conditions simulate typical engine crankshaft rotation input. Results from experimental testing consistently produce results with percent error less than 10 % for mean and maximum belt span dynamic tension.

Keywords: Vibration
Tension
Automotive
Measurement
Advisor: Zu, Jean W.
Development of Surrogates for Aviation Jet Fuels

Surrogate fuels are mixtures of pure hydrocarbons that mimic specific properties of a real fuel. The use of a small number of pure compounds in their formulation ensures that chemical composition is well controlled, helping increase reproducibility of experiments and reduce the computational cost associated with numerical modeling. In this work, surrogate mixtures were developed for Jet A fuel based on correlations between fuel properties (cetane number, smoke point, threshold sooting index (TSI), density, viscosity, boiling point and freezing point) and the nuclear magnetic resonance (NMR) spectra of the fuel as a measure of the fuel's chemical composition. Comparison of the chemical composition and target fuel properties of the surrogate fuels developed in this work to a Jet A fuel sample and other surrogate fuels proposed in the literature revealed the superiority of these surrogate fuels in mimicking the fuel properties of interest.

Keywords: Surrogate fuels
Fuel modeling
Surrogate mixture
Quantitative structure property relationship (QSPR)
Advisor: Gulder, Omer L.
Quantification of Damage in Selected Rocks due to Impact with Tungsten Carbide Bits

Impact induced dynamic cracks are produced with a Split Hopkinson Pressure Bar (SHPB) apparatus in two rocks (Kuru granite and Flamboro limestone) with impact velocities ranging from 8 to 12 m/s. Impact bit (tungsten carbide) diameters range from 8mm to 15mm. Dye impregnation combined with UV imaging, CAT scans and Optical scans were employed to study the resulting crack patterns. The resulting damage is quantified in terms of radial crack density on impact surface, crater, crushed zone and crack density with depth. In both rocks &lsquo;total&rsquo; damage obtained is directly proportional (exponential) with bit diameter and impact velocity. The &lsquo;total&rsquo; damage in Kuru granite is found to be greater than Flamboro limestone at all impact velocities; however, the crushed zone in the latter is found to consistently greater than the former. 2D simulations of dynamic fractures with AUTODYN have also been carried out showing good qualitative agreement with experimental results.

Keywords: Damage Quantification in Rocks
low velocity impact experiments
Advisor: Mohanty, Bibhu
The Kurdish Quest for Self-determination: Looking to Individual Experiences to Administer Differences

The issue of Kurdish self-determination within the highly centralized Republic of Turkey has been a controversial issue with its local, national and international dimensions over the years. Without solving this issue, Turkey might not reach the aims of joining the European Union (EU), economic sustainability, literal democracy, pluralism, and peace. After 40 years armed struggle between Kurdish and Turkish sides, two significant suggestions are currently being discussed: a provincial system similar to what the Ottoman Empire accepted with its own multicultural system; second, the current unitary system with more powerful local authorities. This paper analyzes the problem in an inductive method and takes the second approach to evaluate Turkish centralization, modernization, and transformation to French Republicanism. This evaluation concludes with the critique of the French universal citizenship understanding and requirement of more pluralistic, democratic citizenship and administrative model as a solution of minority rights and self-determination problem in Turkey.

Keywords: Kurdish Self-Determination
French Republicanism
Decentralization
Pluralism
Advisor: Schneiderman, David
Settlement Service Providers in Peel Region, Ontario: Challenges, Barriers and Opportunities in the Shadow State

This research examines the challenges and barriers to service provision that newcomer settlement service providers (SSPs) encounter in Peel Region, Ontario. Semi-structured interviews are used to examine if suburban SSPs in the cities of Brampton, Mississauga and town of Caledon, encounter challenges related to providing services to both adult and youth newcomers. The findings indicate that government funding, and the conditions tied to that funding, are the greatest challenge for SSPs in Peel. Funding restrictions also produced challenges related to the structure and continuity of services and competition between service providers. Due to Peel's varied geography, transportation and organization location are challenges for some rural service providers. Service specific challenges are encountered largely in providing employment and mental health services. Reconsidering government policies around funding for settlement services is necessary. It is recommended that both SSPs and municipalities be integrated into settlement policy decisions.

Keywords: Immigration
Neoliberalism
Suburb
Settlement Integration
Advisor: Wilson, Dana
Wilson, Kathi
A Microfluidic, Extensional Flow Device for Manipulating Soft Particles

A computer-controlled microfluidic extensional flow device is developed for trapping and manipulating micron-sized hard and soft particles. The extensional flow is generated in a diamond-shaped cross-slot that has each corner connected to a pressure-controlled liquid reservoir. By employing an imaging-based control algorithm, a particle can be made to move to an arbitrary position within the slot by adjusting the reservoir pressures and hence the fluid flow rates into/out of the slot. Thus, a soft particle can be trapped indefinitely at a point within the slot, and a known hydrodynamic force can be applied to study the dynamics of stretching and breakup of the particle. Alternatively, adhesion or coalescence dynamics of soft particles may be investigated by effecting a controlled collision between two particles. The device is validated by measuring the low interfacial tension of a compatibilized oil-water interface.

Keywords: Microfluidic
particle trapping
extensional flow
tentiometry
Advisor: Ramachandran, Arun
Lithium-Ion Battery Modeling for Electric Vehicles and Regenerative Cell Testing Platform

Electric Vehicles (EVs) have gained acceptance as low or zero emission means of transportation. This thesis deals with the design of a battery cell testing platform and Lithium-Ion (Li-Ion) battery modeling for EVs. A novel regenerative cell testing platform is developed for cell cycling applications. A 300 W - 5 V cell cycler consisting of a buck and a boost converter is designed. Furthermore, a novel battery modeling approach is proposed to accurately predict the battery performance by dynamically updating the model parameters based on the battery temperature and State of Charge (SOC). The comparison between the experimental and the model simulation results of an automotive cell under real-world drive-cycle illustrates 96.5% accuracy of the model. In addition, the model can be utilized to assess the long-term impact of battery impedance on performance of EVs under real-world drive-cycles.

Keywords: Electric Vehicle
Lithium-Ion Battery
Advisor: Trescases, Olivier
Differential Effects of Chronic Fluoxetine on the Behaviour of Dominant and Subordinate Naked Mole-rats

Naked mole-rats are eusocial rodents that live in subterranean colonies with a strict reproductive and social hierarchy. Breeders are socially dominant and other colony members are non-reproductive subordinates. The effects of manipulating the serotonergic system on aggression are well studied in many species, but not in eusocial rodents like the naked mole-rat. For the current study, the effects of fluoxetine hydrochloride (FLX) on status-specific behaviours of subordinates (Experiment 1) and queens (Experiment 2) were evaluated both in-colony and in a social-pairing paradigm to investigate how the serotonergic system influences aggression in this species. In accordance with our main hypothesis, chronic treatment of FLX attenuated the frequency and duration of aggression in queens, but not subordinates, when paired with an unfamiliar conspecific. Further exploration of pharmacological manipulation on status-specific behaviours of this eusocial species may elucidate the neurobiological mechanisms underlying their unique and rigid social hierarchy.

Keywords: 5-hydroxytryptamine (5-HT)
Fluoxetine hydrochloride (Prozac)
Naked mole-rat
Social behaviour
Social status
Advisor: Holmes, Melissa M.
Should the Pythagorean Theorem Actually be Called the 'Pythagorean' Theorem

This paper investigates whether it is reasonable to bestow credit to one person or group for the famed theorem that relates to the side lengths of any right-angled triangle, a theorem routinely referred to as the “Pythagorean Theorem”. The author investigates the first-documented occurrences of the theorem, along with its first proofs. In addition, proofs that stem from different branches of mathematics and science are analyzed in an effort to display that credit for the development of the theorem should be shared amongst its many contributors rather than crediting the whole of the theorem to one man and his supporters.

Keywords: Pythagoras
Pythagorean Theorem
Advisor: Repka, Joseph
The Role of Human Leukocyte Antigen-G in Cardiac Allograft Vasculopathy

Human leukocyte antigen-G (HLA-G), a non-classical MHC I protein, plays an essential role in immune tolerance and is associated with a lower incidence of graft rejection and cardiac allograft vasculopathy (CAV). To examine the pattern of HLA-G expression post-transplantation we determined that HLA-G can be up-regulated in smooth muscle cells (SMCs) following exposure to everolimus. We also determined that HLA-G at 500 and 1000 ng/ml reduces SMC proliferation. In further studies, treatment with HLA-G inhibited TNFα-stimulated neutrophil adhesion to endothelial cells (ECs) at all concentrations tested (0.1-1 ng/ml), suggesting a role in inflammation. The expression of HLA-G is influenced by a polymorphism in the HLA-G gene. We sought to determine if the 14bp insertion/deletion polymorphism can predict the development of CAV. There was no association between this polymorphism and CAV; however, this study had a small number of patients; therefore further investigations are needed to confirm these findings.

Keywords: HLA-G
Heart Transplantation
Cardiac Allograft Vasculopathy
Immune System
Advisor: Rao, Vivek
Li, Ren-Ke
East-West Asymmetry in Coastal Temperatures of Hudson Bay as a Proxy for Sea Ice

The seasonal asymmetry in coastal temperatures on Hudson Bay was explored and evaluated as a proxy to hindcast sea ice conditions prior to 1972. Various indices of air temperature difference (∆T) between Churchill, MB and Inukjuak, QC were tested for linear correlations with spatially averaged sea ice concentration (SIC) and ice-free season length (IFS). A multiple regression equation employing a 31-day average of peak ∆T and a 61-day average of temperature during freeze-up reproduced the IFS record with an average error of 8.1 days. This equation was employed to extend the IFS record by 28 years. The resulting 68-year time series revealed a significant increasing trend most pronounced from 1985 to 2011. Hindcast data helped eliminate low-frequency climate oscillations of periodicity <68 years as a source of this trend, lending further evidence to the growing consensus of a declining sea ice being the result of anthropogenic climate forcing.

Keywords: Sea Ice
Hudson Bay
Proxy
Advisor: Gough, William A.
Auditory Interface Design to Support Rover Tele-operation in the Presence of Background Speech: Evaluating the Effects of Sonification, Reference Level Sonification, and Sonification Transfer Function

Preponderant visual interface use for conveying information from machine to human admits failures due to overwhelming the visual channel. This thesis investigates the suitability of auditory feedback and certain related design choices in settings involving background speech. Communicating a tele-operated vehicle’s tilt angle was the focal application. A simulator experiment with pitch feedback on one system variable, tilt angle, and its safety threshold was conducted. Manipulated in a within-subject design were: (1) presence vs. absence of speech, (2) discrete tilt alarm vs. discrete alarm and tilt sonification (continuous feedback), (3) tilt sonification vs. tilt and threshold sonification, and (4) linear vs. quadratic transfer function of variable to pitch. Designs with both variable and reference sonification were found to significantly reduce the time drivers spent exceeding the safety limit compared to the designs with no sonification, though this effect was not detected within the set of conditions with background speech audio.

Keywords: sonification
auditory
auditory display
speech
rover
tilt
reference sonification
sonification mapping
sonification transfer function
voice
Advisor: Donmez, Birsen
The Association of Human Papillomavirus with Oral Lesions

The oral cavity is a common site for human papillomavirus (HPV) infection, however much is still unknown about the spectrum of oral lesions associated with HPV. The prevalence of HPV was investigated in oral dysplasias and papillary lesions using a combination of ISH, p16 and MIB-1 immunohistochemistry. Results show that a subset of high grade oral epithelial dysplasias demonstrated evidence of high-risk HPV infection. Follow-up information suggests a difference in the behaviour of HPV-positive and HPV-negative high grade dysplasias. Oral papillary lesions are a heterogeneous group with variable clinical behaviour. Results support an association of low-risk HPV with papillary lesions that run a benign clinical course, despite the presence of atypia. Other oral papillary lesions with atypical features represent potentially malignant lesions that may progress to carcinoma. Potentially malignant and malignant papillary lesions are not associated with HPV infection. Infection with low versus high-risk HPV results in distinct clinical manifestations.

Keywords: human papillomavirus
oral pathology
Advisor: Bradley, Grace
Metalloporphysomes: Engineering New Metalloporphyrin Nanoparticles

Porphyrins are naturally occurring molecules. Porphysomes are simple multimodal nanoparticles that derive their multifunctionality from porphyrin-based building-blocks. While previous studies have probed their interactions with light, their capacity to stably chelate metal ions has gone largely uninvestigated. Herein are presented and discussed two investigations into metalloporphysomes. First is a method for non-invasively labeling porphysomes with radioactive copper-64. Utilizing exceptionally simple chemistry, this method produces a highly stable radiotracer capable of both PET and fluorescence imaging. Second is a profile of a MRI-detectable, photothermal agent whose photonic properties are serendipitously improved by the incorporation of MRI-active metal ions. By taking advantage of simple chemical substitutions, these studies illustrate methods of accessing new functionalities while maintaining a deeply simple construct, an often overlooked aspect in the development of multimodal nanoparticles.

Keywords: Nanomedicine
Imaging
Cancer
PET
MRI
Porphyrins
Advisor: Zheng, Gang
Software Based GPU Framework

A software based GPU design, where most of the 3D pipeline is executed in software on shaders, with minimal support from custom hardware blocks, provides three benefits, it: (1) simplifies the GPU design, (2) turns 3D graphics into a general purpose application, and (3) opens the door for applying compiler optimization to the whole 3D pipeline. In this thesis we design a framework and a full software stack to support further research in the field. LLVM IR is used as a flexible shader IR, and all fixed-function hardware blocks are translated into it. A sort-middle, tile-based, architecture is used for the 3D pipeline and trace-file based methodology is applied to make the system more modular. Further, we implement a GPU model and use it to perform an architectural exploration of the proposed software based GPU system design space.

Keywords: GPU
3D graphics
Gallium3D
LLVM
Mobile GPU
Software GPU
Advisor: Zhu, Jianwen
The Role of TLR3 in the Development of Lupus-like Autoimmunity in B6.NZBc13 Mice

The New Zealand Black (NZB) mouse chromosome 13 (c13) is linked to development of autoimmunity. B6 mice containing a portion of NZBc13 (B6.NZBc13 (c13)) develop a lupus phenotype that includes: autoantibody production, increased B and T cell activation, and marginal zone B cell and myeloid dendritic cell expansions. c13 mice have a B cell intrinsic dsRNA-sensing defect, leading to increased TLR3 expression and survival. The role of the aberrant dsRNA sensing in the generation of the c13 autoimmune phenotype was assessed by generating c13 mice with TLR3 knocked out (c13.TLR3KO). Marginal zone B cell expansion and B cell activation were attenuated in c13.TLR3KO mice, but other cellular phenotypes were not affected. Autoantibody production was partially reduced. These results indicate that altered dsRNA-sensing contribute to a portion of the altered cellular phenotypes in c13 mice, but that other susceptibility loci in the c13 interval are required for full development of autoimmunity.

Keywords: Autoimmunity
mouse model
SLE
Advisor: Wither, Joan
Design and Evaluation of a Mobile Health Application for Adult Patients with Type 1 Diabetes Mellitus

In this study, a user-centred design approach was used to develop a mobile health application designed to support adult T1DM patients with their self-management routine. In the requirements gathering phase, an observational study of a diabetes clinic and patient interviews were conducted. An analysis of the data collected from this phase helped identify the functional design requirements used to guide the design. Using a rapid prototyping approach, data visualizations, game-based elements, carb-counting and social networking features were explored. The final prototype developed in this research was evaluated for its ease of use and perceived usefulness. The design was found to be generally easy to use. With respect to data visualizations, participants preferred the scatter plot view of their blood glucose readings to a bar chart. In addition, it was found that all participants wanted a way to track their HbA1c on a regular basis.

Keywords: eHealth
User Centred Design
mobile
diabetes
adolescents
Advisor: Chignell, Mark
In Vitro Human Engineered Myocardium: A Study into both Pathological and Physiological Hypertrophy

The ability to generate cardiomyocytes from either embryonic stem cells or induced pluripotent stem cells provides an unprecedented opportunity to establish human in vitro models of cardiovascular disease as well as to develop platforms for the testing of novel cardiac therapeutics. We designed two different platforms, a biowire platform and post deflection platform, to generate engineered heart tissues (EHTs) to study a fundamental process in cardiomyocytes: hypertrophy. Both pathological and physiological hypertrophy was studied in order to garner a better understanding of each process. Physiological hypertrophy characteristics were observed using the biowire platform seen in improved myofibril alignment and downregulation of fetal genes. When electrical stimulation was added, a rate dependent effect on sarcomere maturation was observed by the increased frequency of I-bands and H-zones. Certain hallmark features of pathological hypertrophy, such as upregulation of brain natriuretic peptide and sarcomere structure breakdown, were recapitulated when EHTs were treated with isoproterenol.

Keywords: Cardiomyocyte
Stem Cells
Tissue Engineering
Disease Modelling
Advisor: Radisic, Milica