VictorJuiz/thesis huggingface dataset:
Dental Treatment Workload and Cost of Newly Enrolled Personnel in the Canadian Forces

Aim: To describe and analyze the demographic profile and the dental treatment needs, workload and costs of the 2007 and 2008 CF recruit population (N=10,641). Method: Treatment procedures and costs were aggregated and calculated, beginning from the date of a member’s enrolment, over a period that ranged between 13 to 36 months. Associations between treatment services and the demographic variables were tested using one-way ANOVA and chi-square tests. Independent samples T-test was used to compare means. Linear regression models were used to determine the influence of demographic variables on treatment cost. Results: Treatment needs and costs varied with recruit age, gender, rank, first language (French/English), birthplace (Canada/Foreign), tobacco use, province and census tract. The cost of treatment for the entire population was $13.9M. Mean cost per recruit was $1224 over an average period of 26 months. Outsource costs ($2.9M) were driven by referrals for restorative, endodontic and oral surgery procedures.

Keywords: Canadian Forces
military recruits
dental treatment needs
dental treatment workload
dental treatment requirements
dental services
dental treatment costs
oral health
area-based measures
young adults
Advisor: Quiñonez, Carlos
Power-scavenging Tumbleweed Rover

Most current space robotics vehicles use solar energy as their prime energy source. In spherical robotic vehicles the use of solar cells is very restricted. Focusing on the particular problem, an improved method to generate electrical power will be developed; the innovation is the use of an internal pendulum-generator mechanism to generate electrical power while the ball is rolling. This concept will enable spherical robots on future long-duration planetary exploration missions. Through a developed proof-of-concept prototype, inspired by the Russian thistle plant, or tumbleweed, this thesis will demonstrate power generation capabilities of such a mechanism. Furthermore, it will also present and validate a parametric analytical model that can be used in future developments as a design tool to quantify power and define design parameters. The same model was used to define the design parameters and power generation capabilities of such a system in Martian environment.

Keywords: tumbleweed rover
inflatable robot
pendulum
power generation
generator
planetary exploration
spherical robot
Advisor: Barfoot, Timothy D.
A Peptide Comprising the Src-interacting Domain of NADH Dehydrogenase Subunit 2 Alleviates Complete Freund's Adjuvant-induced Allodynia in Rats

Inflammatory and neuropathic pains arise in part from sensitization at nociceptive synapses in the spinal cord. Activity-dependent signaling cascades converge onto the tyrosine kinase Src, which participates in augmenting the function of N-methyl-D-aspartate receptors (NMDARs) and thus potentiates the nociceptive system. Src is capable of these effects because it is anchored to the NMDAR complex via an adaptor protein called NADH dehydrogenase subunit 2 (ND2). There is evidence that this interaction occurs between amino acids 40-49 of Src and amino acids 310-321 of ND2. I have determined that a peptide consisting of amino acids 310-321 of ND2, and affixed to the HIV Tat domain for cell permeability, is capable of alleviating tactile allodynia induced by Complete Freund's Adjuvant (CFA) in rats. Src40-49Tat was not effective in two models of inflammatory pain. This work further implicates the Src-ND2 interaction in pain hypersensitivity and suggests that Tat ND2 310-321 may alleviate it.

Keywords: pain
central sensitization
Src
NADH Dehydrogenase Subunit 2
Advisor: Tymianski, Michael
The Fiction of Globally Important Biodiversity: The Production of Scale through the Global Environment Facility’s Biodiversity Policy and Programming

The gap observed between the rhetoric and reality of biodiversity conservation draws critical attention to the discourse of conservation and to claims that local and global interests can be balanced. In this work, I suggest that the spatial framing of organized biodiversity conservation inhibits attempts to produce such 'balance'. I examine the processes by which biodiversity conservation projects are brought into being through the discursive production of scale within the institutional framework of the Global Environment Facility (GEF). Using five case studies of projects proposed under the GEF’s operational program for agrobiodiversity, I analyze how the GEF brings actors and sites into relation and engages them in the reproduction of articulations of scale through the GEF project cycle. In so doing, I reveal how the mechanisms that structure conservation projects around global goals systematically undermine the claims of situated resource users and prevent questions of justice from being raised.

Keywords: biodiversity conservation
production of scale
Global Environment Facility
global environment
global environmental benefits
agrobiodiversity conservation
conservation discourse
Advisor: MacDonald, Kenneth
Insulin-induced Suppression of A-type GABA Receptor Signaling in the INS-1 Pancreatic β-cell Line

GABA and GABA type A receptor (GABAAR) are expressed in pancreatic β-cells and comprise an autocrine signaling system. How the GABA-GABAAR system is regulated is unknown. In this study, I investigated insulin’s effect on this system in the INS-1 β-cell line. I found that GABA evoked current (IGABA) in INS-1 cells, resulting in membrane depolarization. Perforated-patch recordings showed that pre-treatment of insulin or zinc-free insulin suppressed IGABA in INS-1 cells (p < 0.01). Radioimmunossay showed that GABA (30 μM) increased C-peptide secretion from INS-1 cells, which was blocked by GABAAR antagonist picrotoxin, indicating that GABA increased insulin secretion through activation of GABAAR. However, insulin significantly reduced the stimulatory effect of GABA on C-peptide secretion (p < 0.05). These data suggest that GABA released from β-cells positively regulates insulin secretion via GABAAR activation, and that insulin negatively regulates the β-cell secretory pathway likely via inhibiting the GABA-GABAAR system in β-cells.

Keywords: GABA
Insulin
Beta-cell
Autocrine
GABA receptor
Islet
Electrophysiology
Advisor: Wang, Qinghua
Lu, Wei-Yang
A Method of Measuring Force/Torque at the Tool/Tissue Interface in Endoscopy

The adoption of Minimally Invasive Surgery (MIS) and Robot-Assisted MIS has resulted in the distortion of haptic cues surgeons rely on. The application of excessive force during port creation has lead to increased surgical access trauma. This study aims to quantify the forces experienced during port creation with a blunt-ended Threaded Visual Cannula (TVC) in an effort to ameliorate patient safety, provide a quantitative platform for surgeon training, and offer a gateway for the eventual automation of this problematic aspect of MIS. A method of determining the torque encountered during port creation was established. It was found that the magnitude of torque required to cannulate different materials was unique and was dictated by the friction observed at the tool/tissue interface. Furthermore, the ability to detect instantaneous changes in torque arising from the transition between two different media was not found to be possible with the current design of the TVC.

Keywords: Endoscopy
Robotic Surgery
Patient Safety
Surgeon Training
Torque
Haptics
Advisor: Ternamian, Artin
Benhabib, Beno
Functional Magnetic Resonance Imaging of Laparoscopic Surgery Training Tasks

Previous studies have shown that not all surgical residents can acquire the required skills for performing laparoscopic surgery. Therefore, the training methods can be improved to accommodate trainees with different psychomotor abilities. The first step towards improving training methods is understanding the brain function in performing the laparoscopic surgery training tasks, which can be facilitated by neuroimaging methods such as functional magnetic resonance imaging (fMRI). In this study, a laparoscopic surgery training box for use in fMRI was developed. Experiments confirmed the fMRI-compatibility of the device. Nine right-handed subjects underwent fMRI while performing the surgical training tasks after ten practice sessions in a simulated fMRI environment. Behavioural and fMRI results confirmed the feasibility of using this simulator and revealed the neuroanatomical correlates associated with performing the training tasks. Accordingly, this study may facilitate the evidence-based development of strategies to improve the quality of laparoscopy training and assessment strategies.

Keywords: fMRI
Laparoscopic Surgery
Advisor: Schweizer, Tom
Effects of Attention on Change Deafness

Detecting acoustic changes in our environment, such as a rattlesnake’s sudden approach, can be essential for survival. Although auditory change detection has been intensively investigated using sequentially-presented sounds, very little is known about how we detect changes in a natural, complex scene comprised of multiple concurrent sounds. The present study used a location-switch change deafness paradigm; on each trial, participants listened to two consecutive auditory scenes, consisting of three natural sounds played in distinct locations, and reported if the two scenes were the same or identified the two sounds that switched locations. Directing a listener’s attention to a changing sound improved accuracy and decreased reaction time, relative to uncued trials. However, when participants’ attention was invalidly directed to a non-changing sound object, performance suffered. Further analyses showed that these effects could not be explained by energetic masking. Thus, attention is necessary for change identification in complex auditory scenes.

Keywords: auditory
attention
Advisor: Alain, Claude
Power Grid Correction Using Sensitivity Analysis

Power grid voltage integrity verification requires checking if all the voltage drops on the grid are less than a certain threshold that guarantees proper circuit operation. This thesis addresses the problem of correcting the grid when some voltage drops exceed this threshold by making minor modifications to the existing design. The method uses current constraints that capture the uncertainty about the underlying circuit behavior to find the maximum voltage drop on the grid, and then to estimate the voltage drop as a function of the metal widths on the grid. It formulates a nonlinear optimization problem and finds the required change in widths that reduces the maximum voltage drop on the grid below the threshold while keeping the total area cost at a minimum.

Keywords: Sensitivity analysis
Linear programming
Power grid
Advisor: Najm, Farid N.
Early Dual Grid Voltage Integrity Verification

As part of power distribution network verification, one should check if the voltage fluctuations exceed some critical threshold. The traditional simulation-based solution to this problem is intractable due to the large number of possible circuit behaviors. This approach also requires full knowledge of the details of the underlying circuitry, not allowing one to verify the power distribution network early in the design flow. In this work, we consider the power and ground grids together (i.e. dual grid) and formulate the problem of computing the worst-case voltage fluctuations of the dual grid under the framework of current constraints. Then, we present a solution technique in which tight lower and upper bounds on worst-case voltage fluctuations are computed via linear programs. Experimental results indicate that the proposed technique results in errors in the range of a few mV . We also present extensions to single grid (i.e. only power grid) verification techniques.

Keywords: voltage integrity
vectorless grid verification
current constraints
p/g grid
early grid verification
Advisor: Najm, Farid N.
RSS-based WLAN Indoor Positioning and Tracking System Using Compressive Sensing and Its Implementation on Mobile Devices

As the demand of indoor Location-Based Services (LBSs) increases, there is a growing interest in developing an accurate indoor positioning and tracking system on mobile devices. The core location determination problem can be reformulated as a sparse natured problem and thus can be solved by applying the Compressive Sensing (CS) theory. This thesis proposes a compact received signal strength (RSS) based real-time indoor positioning and tracking systems using CS theory that can be implemented on personal digital assistants (PDAs) and smartphones, which are both limited in processing power and memory compared to laptops. The proposed tracking system, together with a simple navigation module is implemented on Windows Mobile-operated smart devices and their performance in different experimental sites are evaluated. Experimental results show that the proposed system is a lightweight real-time algorithm that performs better than other traditional fingerprinting methods in terms of accuracy under constraints of limited processing and memory resources.

Keywords: RSS
WLAN
Indoor positioning
Indoor tracking
Compressive sensing
Affinity propagation
Kalman filter
Navigation
mobile devices
Advisor: Valaee, Shahrokh
Coding of Bat-like Auditory Features in the AN2 Interneuron of the Pacific Field Cricket, Teleogryllus oceanicus and its Relation to Decreasing the Conspicuousness of Synthetic Bat Echolocation Calls

Many insects have auditory systems capable of detecting the ultrasonic calls of insectivorous bats and use these cues to evade capture. I tested the hypothesis that bats can decrease the conspicuousness of their echolocation calls by varying three call features: duration, repetition rate and ramp times. This was done by examining the AN2 command interneuron’s response to these features in the cricket, Teleogryllus oceanicus, after describing the firing pattern necessary for evasive behaviour. Past studies on duration and repetition rate suggest increased thresholds for short durations and low repetition rates. Measurements of the AN2 response, which controls evasive behaviour, indicated that increased thresholds were a result of a decrease in bursting, raw spike numbers and an increase in latencies in the AN2. Results suggest that there is pressure on bats to evade early detection and that this can be done by employing large ramp times in search phase echolocation calls.

Keywords: Neuroethology
Cricket
Bat echolocation
AN2
Neural coding of behaviour
Teleogryllus oceanicus
Escape behaviour
Advisor: Fullard, James H.
Two-photon Microscopy and Polarimetry for Assessment of Myocardial Tissue Organization

Optical methods can provide useful tissue characterization tools. For this project, two-photon microscopy and polarized light examinations (polarimetry) were used to assess the organizational state of myocardium in healthy, infarcted, and stem-cell regenerated states. Two-photon microscopy visualizes collagen through second-harmonic generation and myocytes through two-photon excitation autoﬂuorescence, providing information on the composition and structure/organization of the tissue. Polarimetry measurements yield a value of linear retardance that can serve as an indicator of tissue anisotropy, and with a dual-projection method, information about the anisotropy axis orientation can also be extracted. Two-photon microscopy results reveal that stem-cell treated tissue retains more myocytes and structure than infarcted myocardium, while polarimetry ﬁndings suggest that the injury caused by temporary ligation of a coronary artery is less severe and more diffuse that than caused by a permanent ligation. Both these methods show potential for tissue characterization.

Keywords: Myocardial infarction
Stem cell regeneration
Non-linear optics
Polarimetry
Advisor: Vitkin, Alex
On the Benefits of Distractibility? Inhibitory Control in Media Multitaskers

A study by Ophir, Nass & Wagner found that younger adults who are heavy media multitaskers (HMM) perform worse on cognitive measures assessing inhibitory control. Previous findings indicated no benefit to being an HMM, however extrapolating from the aging literature wherein older adults can use distraction beneficially, the authors hypothesized that HMMs might show parallel gains. Two tasks (Reading with Distraction, and the Flanker task) are reported with regard to trait media multitasking preference in undergraduates. As expected, LMMs generally outperformed HMMs, but less consistently than predicted. The hypothesis was not proven; media multitaskers, while 4x more likely to recognize the implicit nature of the task, were not more likely to use previously distracting information suggesting that a different mechanism is operating in HMMs than older adults who readily use this information.

Keywords: media multitasking
divided attention
inhibition
reading with distraction
polychronicity
multitasking
Advisor: Hasher, Lynn
Grady, Cheryl L.
Pressure Dependence and Volumetric Properties of Short DNA Hairpins

Previous studies of short DNA hairpins have revealed that loop and stem sequences can significantly affect the thermodynamic stability of short DNA hairpins. Nevertheless, there has not been sufficient investigation into the pressure-temperature stability of DNA hairpins, and the current thermodynamic knowledge of DNA hairpins’ stability is limited to the temperature domain. In this work, we report the effect of hydrostatic pressure on the helix-coil transition temperature (TM) for eleven short DNA hairpins at different salt concentrations by performing UV-monitored melting. The studied hairpins form by intramolecular folding of 16-base self-complementary DNA oligo¬deoxy¬ribonucleotides. Model dependent (van’t Hoff) transition parameters such as ΔHvH and transition volume (ΔV) were estimated from analysis of optical melting transitions. Experiments revealed the ΔV for denaturation of these molecules range from -2.35 to +6.74 cm3mol-1. The difference in the volume change for this transition is related to differences in the hydration of these molecules.

Keywords: DNA hairpins
Transition Volume
Short
cruciform
antisense
pressure
hydrostatic
phase diagram
temperature
volume
enthalpy
salt
sodium
hydration
water
loop
stem
hydrophobic
stability
high pressure
melting temperature
ion release
G-quadruplexes
telomeric sequence
G-quartets
DNA tetraplexes
Advisor: Macgregor, Robert B.
The Workplace Challenges of Lupus Patients

Objective: To examine the workplace challenges of lupus patients. Methods: A cross sectional study surveyed lupus patients seen at the Toronto Lupus Clinic in the last 2 years. We included questions on health, work context and psychosocial perceptions. Descriptive statistics described the sociodemographic and clinical characteristics of the sample; multivariable analysis examined factors associated with workplace activity limitations, job strain, and job accommodations. Results: 362 respondents completed the questionnaire (60% response). 49.7% were currently employed. Participants who recently left work had higher disease activity and workplace activity limitations. Employed participants had low to moderate job strain. Seventy percent of employed participants used job accommodations. Health, work context, and psychological factors were significantly associated with workplace activity limitations, job strain and job accommodations. Conclusion: Persons living with lupus are faced by different challenges at the workplace. Workplace difficulties and needs of individuals with lupus should be assessed by health professionals.

Keywords: workplace
lupus
workplace activity limitations
job accommodations
Advisor: Fortin, Paul
Development and Standardization of the NIST Rapid Sulphate Resistance Test

The NIST miniature paste prism test was developed to assess sulphate resistance of cements faster than the commonly used ASTM C 1012 test. The goal of this research is to address the current limitations regarding the NIST procedure to determine the optimum testing parameters and to establish appropriate expansion limits. A range of variables including details of specimen design, curing regime, water-to-cementitious materials ratio, and prism length were tested on the materials with a wide range of sulphate performance. The findings of the study demonstrate that even though it can yield results in only three months, the NIST test can provide an erroneous differentiation between certain cementitious materials. Reliability and repeatability of the test results can be improved by using longer specimens and longer curing times. The NIST test can be used as a preliminary screening test, but users need to be aware of its limitations.

Keywords: sulphate resistance
accelerated testing methods
miniature prisms
cement paste
Advisor: Hooton, Robert Douglas
Serum BMP-2, 4, 7 and AHSG in Patients with Heterotopic Ossification Following Arthroplasty

Purpose: To determine whether reduced serum levels of AHSG and elevated levels of BMP-2, 4, 7 are associated with post-arthroplasty HO. Patients: Thirty arthroplasty patients were included, 15 with evidence of peri-articular HO and 15 without (NHO). Methods: Blood samples were collected from all patients ≥ 8 weeks after arthroplasty. Analytes were measured using ELISAs. Mann-Whitney U tests were performed to compare serum analyte concentrations between HO and NHO groups, and between arthroplasty patients and healthy humans. Results: There is no difference in serum concentrations of AHSG, BMP-2, 4, 7 between HO and NHO patients. Arthroplasty patients showed significantly higher BMP-2 and BMP-4 and lower AHSG serum levels compared to healthy humans (p < 0.01). Conclusion: Baseline BMP-2, 4, 7 and AHSG serum levels are not markers of acquired HO. However, elevated baseline levels of BMP- 2, 4 and reduced levels of AHSG appear to be markers of severe inflammatory arthritis.

Keywords: heterotopic ossification
BMP
AHSG
arthritis
markers
arthroplasty
Joint
surgery
myossitis ossificans
Fetuin
Temporomandibular
Hip
Noggin
Alpha-2 HS glycoprotein
inflammatory
Advisor: Tenenbaum, Howard
Clokie, Cameron
Surface Modifications of Nanocarbon Materials for Electrochemical Capacitors

Multi-walled carbon nanotubes (MWCNTs) were successfully coated with two different pseudocapacitive polyoxometalates (POMs) (SiMo12O40-4 (SiMo12) and PMo12O40-3 (PMo12)) via “Layer-by-Layer” deposition. Even with merely a “single-layer” of POM, the modified nanotubes exhibited more than 2X increase in capacitance compared with that of bare nanotubes. To further improve their electrochemical performances, the deposition sequence of the POM layers was adjusted to form “alternate layer” coating to modify MWCNT. A synergistic effect on the capacitance and kinetics was observed with the alternate layer coatings. X-ray Photoelectron Spectroscopy (XPS) and Scanning Electron Microscopy (SEM) also proved the successful coating of POMs on MWCNTs. The potential-pH relationship provided important insights in terms of the deposition mechanism and suggested that the bottom layer close to the electrode substrate was the dominating layer in alternate layer coated MWCNT electrodes.

Keywords: Nanocarbon
Electrochemical Capacitor
Polyoxometaltes
Layer by Layer Deposition
Pseudocapacitance
MWCNT
Advisor: Lian, Keryn