VictorJuiz/thesis huggingface dataset:
Measuring Attentional Bias Among Abstinent Smokers with a Manual Aiming Task
Keywords: attentional bias
manual aiming
smoking

Attentional bias (AB) is exhibited by substance users for addiction-related stimuli, influencing consumption, craving, and relapse. Due to limitations of AB measurements, this study developed and evaluated a novel method using manual aiming (MA). Participants completed modified visual dot-probe tasks while monitoring their eyes and limb movements. Reaction time (RT), movement time (MT), and limb trajectory (LT) were measured and compared between non-smokers (n=15) and abstaining smokers (n=13) and within smokers. Using 3 (probe) x 2 (accompanying image) x 2 (group) ANCOVAs, controlling for age, there were no significant differences for RT or LT. Trends for group and condition differences in MT were found although in the opposite direction. As expected, cravings negatively correlated with the time elapsed to complete MA. There was some tentative evidence to suggest that AB may have properties that can be examined by MT. Replication is needed with a larger sample and more dependent smokers.
Geographic Effects on Vehicle Reliability: Developing Proportional Hazards Models for a Deployable Military Vehicle
Keywords: Armoured Vehicles
Military
Preventive Maintenance
Proportional Hazards Model
Reliability
Spare Parts

Unlike many industries that have their equipment in one location with consistent usage patterns, armies move their vehicles between different geographic locations with varying environmental, and usage conditions. This creates interesting conditions for study, as those geographic changes can be studied to detect their effect on system reliability.Unfortunately, this is not being fully exploited, due in part to the poor capture and storage of information, a problem faced by many operators of maintenance databases.This thesis develops a method to characterize failure data contained in a maintenance database using a standardized naming system, and applies a proportional hazards model for each geographic location using covariates to represent the conditions. In addition to understanding how a system has performed, the proportional hazards model will allow geographic location factors to be used in predicting system reliability and spares parts requirements in a new location.
Light Management across the Nano and Macro Lengthscales to Enhance Photovoltaic Device Performance
Keywords: Colloidal quantum dots
Folded light path
Photovoltaics
Plasmonics

Colloidal quantum dot photovoltaics (CQDPV) have the potential to be a low cost and renewable source of electricity, with state-of-the-art CQDPV certified at a power conversion efficiency of 8.5%. What prevents further breakthroughs in performance is the limitation placed by the electron diffusion length of CQD materials. The compromise between two interrelated drivers of solar cell performance - the ability to extract charge carriers versus the amount of photons being absorbed - needs to be solved. There are solutions available on both the macro and the nanoscales, through careful design of the device architecture and substrates. Herein, we utilized a structured plasmonic electrode for the nanoscale case and a folded-light-path architecture for the macroscopic case to improve light absorption. Through these techniques, we observe 20% improvement in short-circuit current, leading to a 10% enhancement in power conversion efficiency. In addition, the operational mechanisms and design constraints for integrating these techniques are discussed.
Biomechanics of Acute Total Hip Arthroplasty after Acetabular Fracture: Plate vs Cable Fixation
Keywords: Acetabulum
Arthroplasty
Biomechanics
Cable
Fixation
Hip

The incidence of complex acetabular fractures is increasing worldwide, especially in the elderly. Fixation methods currently used surgically have no biomechanical justification. Therefore, this study compared the standard plate versus three cable techniques for anterior column plus posterior hemitransverse acetabular fractures in synthetic hemipelves. Phase I employed FEA validated by non-destructive mechanical testing. Phase II entailed destructive comparison of the superior cabling method from Phase I versus the standard plating procedure. Phase I identified the Mouhsine cable method as providing the best mechanical stability (i.e. based on lowest peak bone stress) among the cable techniques. Phase II demonstrated the Plate group's superiority over the Mouhsine group for 2 outcomes (i.e. stiffness and failure force at clinical failure), its inferiority for 2 outcomes (i.e. failure displacement and gapping for posterior markers at mechanical failure), and statistical equivalence for the remaining outcomes. This investigation has implications for surgical repair of this injury.
Guidance of Selective Attention by Conceptually- generated Working Memory Templates
Keywords: Biased Competition
Short-term Memory
Visual Attention
Visual Search
Visual Working Memory
Working Memory

We tested whether colour concepts associated with words held in verbal working memory (WM) could guide selective attention. Participants held one or three words in WM while performing a visual search during the delay period. Critically, the word(s) were semantically associated with a colour concept (e.g., lipstick, tomato), which matched the colour (e.g., red) of either a target or a distractor in the search array. In Experiment 1, search times were faster when the colour concept matched a target and slower when the colour concept matched a distractor. In Experiment 2, we eliminated the effect by extending the delay between WM encoding and search, suggesting that the effect is transient. Finally, we found that modulation of search times by verbal WM correlated with visual WM capacity (k). Overall, our results show that amodal conceptual knowledge can activate a perceptual attentional template, which enhances processing of subsequent sensory input.
Hand Position Affects Perceptual Grouping
Keywords: near-hand vision
object perception
perception and action
perceptual grouping

Over the past decade evidence has accumulated showing that performance of attention, perception, and memory related tasks are influenced by placing the observer's hands near the stimuli. Two theories have been proposed to account for these effects. The attentional account holds performance is altered due to changed attentional prioritization of hands-proximal space, while the differential pathways hypothesis holds processing of stimuli near the hands is dominated by the magnocellular visual pathway resulting in the variety of documented effects. Here we test whether perceptual grouping processes are inhibited in hand-proximal space. Consistent with previous work on object-based attention, we find a benefit for the visual object in the hands-distal, but not the hands-proximal, condition suggesting perceptual grouping is impaired near the hands. This change in perceptual grouping processes cannot be explained solely by an attentional account of visual processing changes near the hands.
Chiral Diamine-based Reduction and Oxidation Catalysts
Keywords: diamine
epoxidation
hpen
hydrogenation
salen
stereoselectivity

Asymmetric catalysis remains one of the most significant ways for introducing chirality into prochiral molecules. There is much interest in elucidating mechanistic details and optimizing conditions for preexisting systems. Using a combination of experimental and computational methods, we separately explored two reactions: asymmetric transfer hydrogenation and alkene epoxidation. For the diamine-based hydrogenation catalyst, a series of diphenylethylenediamine derivatives were synthesized and used to test the electronic effect of diamine ligands on the rate of hydrogenation. Contrary to previous findings, we report virtually no difference in catalytic activity between the various ligands. Computational analysis consolidates our results. For the manganese-salen catalyzed epoxidation, we present an original mechanism to explain the observed stereoselectivity. Instead of the traditional "side-on approach", we propose that epoxidation proceeds through a planar transition state with sp2 hybridized manganese-oxo oxygen. This model correctly predicts the sense and degree of stereoselectivity for a number of catalyst and substrate systems.
Evaluation of Low-cost MEMS Accelerometers and Investigation of Inertial Algorithms for Dead Reckoning in Railway Environment
Keywords: accelerometer
localisation
MEMS
navigation
robotics
sensors

Low-cost micro-electro-mechanical systems (MEMS) accelerometers are gaining momentum in the defence, aerospace, transportation, and automotive industries. While highcost accelerometers are being used on subway trains for their signalling systems, this work investigates the possibility of replacing them with low-cost MEMS devices. To achieve this goal, a 3D printer was modied for use as a three-dimensional motion platform and sensors were tested based on various characteristics. In addition, the sensors were tested on subway trains. The results show that the Kionix KXRB5 accelerometer performs the best, even out-performing the high-end sensor tested. Finally, inertial algorithms were developed that were able to estimate displacements to below 5% error on the evaluation platform and subway line. Although realtime displacement estimations were not accurate due to unstable bias due to tilting, these inertial algorithms use only the accelerometer sensor and can update displacements at points of zero velocity.
Glucocorticoid-Induced Osteoporosis Management Among Seniors
Keywords: Glucocorticoids
Health Services Research
Osteoporosis
Practice Patterns

Background: Chronic oral glucocorticoid (GC) therapy is the leading cause of secondary osteoporosis, resulting in rapid bone loss and increased fracture risk. Objective: To examine trends in GC-induced osteoporosis management, by sex and over time. Methods: Using Ontario healthcare utilization data, we determined the proportion of chronic oral GC users (age 66+) who received a bone mineral density test and/or osteoporosis treatment within 6 months of starting chronic GC therapy. Results: We identified 72,099 male and 95,975 female patients on chronic GC therapy between 1996 and 2012. Overall, 15% of men and 36% of women on chronic oral GC therapy received osteoporosis management. However, among patients without prior osteoporosis management, only 12% of men and 23% of women received osteoporosis management within 6 months. Conclusion: GC-induced osteoporosis management improved significantly over time in both sexes yet remains low, particularly among men. This represents a missed opportunity for fracture prevention among patients requiring prolonged GC therapy.
Face Motion Influences Eye Movement Patterns and Face Processing in Children
Keywords: development
face
gaze
motion
perception
processing

The present study examined the influence of face motion on processing strategy and eye movement patterns in 4- to 6-year-old children. The results indicated that face motion influenced featural processing similar to previous studies with adults, though this effect was not different from that of static images. Consistent with previous studies in infancy and childhood, eye-tracking analyses revealed that observing moving faces attracted longer fixation times in the mouth region and less at the eye regions compared to static images. These findings suggest that, while face processing strategy was no different when shown in motion compared to static, face motion influences eye movement patterns in early childhood.
The Fourth Estate in the Sixth Grade: Exploring "News" in the Lives of Canadian Pre-teens Through Creative Media Inquiry
Keywords: creative methods
engagement
media education
news
pre-teens
youth

This thesis explores how young people conceive of and engage with news in the current Canadian context. It suggests the need to transcend notions of youth as either "disengaged" or "disenfranchised" in relation to news by exploring questions such as "what counts as 'news'?" and "what does news engagement look like?" The study involved one class of Grade Six students (n=26) in the Greater Toronto Area in a mix of participatory, creative activities and interviews. The results illustrated participants' diverse ways of defining news or "news vocabularies" and the importance of friends and family members to the "news ecologies" they live in and interact with. Results also demonstrated the unique complexities pre-teens face in their relationships with news. Overall, this thesis calls for further critical thinking around how Canadian society understands young people as news users, and how young people utilize news to reproduce and transform the cultures they inhabit.
The PREVENT Study: Psychiatric Reporting to Ease Vehicular Events Near Traffic
Keywords: Mental Health
Motor Vehicle Crashes
Traffic Safety

This thesis analyses health services data for a group of 23,145 patients who were warned by their physicians regarding motor vehicle driving risks between April 1, 2006 and March 31, 2011. A three-year baseline interval prior to the warning was compared to the one year subsequent to the warning for the rate of involvement in motor vehicle crashes and for psychiatric hospitalization. The relative risk of involvement in a serious crash in the subsequent compared to the baseline interval was 0.69 (95% confidence interval 0.59 to 0.81, P
Theorizing Paradox and Agency: Muslim Women between Creativity and Constraint
Keywords: Agency
Islam
Muslim Women
Paradox
Resistance

This thesis analyzes critical conceptions of human agency, resistance and freedom as well as their implications for conceiving of human action and experience in complex, life affirming ways. I pursue this analysis by examining the contemporary debate surrounding the agential capacity and embodied practices of the "Muslim woman." I argue that contemporary feminist disagreements regarding how the "Muslim woman" exercise and embody their agency belittle the possibility of paradox from entering the discursive realm. Current debates eclipse the idea that there is an essential existential tension where human agency is understood as being entangled within the terrains of creativity and constraint. Addressing paradox in the face of the worldwide cultural preoccupation with the "Muslim woman" can help reconfigure our social imagining of the practice of agency and resistance, while revealing the living paradox that we are both bound and free.
The Foraging Gene and Aggression in the Vinegar Fly, Drosophila melanogaster
Keywords: aggression
behavioral polymorphism
foraging gene

Understanding the causes of phenotypic diversity and evolution is a central challenge for evolutionary biology. The genetic basis of behavioral diversity is currently poorly understood. I provide a selected review describing the extent of our currrent knowledge on the causes of variation in aggressive behaviors and perform a series of genetic experiments on two strains of the vinegar fly (Drosophila melanogaster) called forR "Rover" and forS "Sitter". I investigate how the foraging gene contributes to differences in aggression between pairs of forR and pairs of forS flies and show 1) that F1 heterozygotes derived from a cross between forR and forS strains display intermediate aggression levels when paired against each other 2) that a null mutation at the foraging locus diminishes aggression levels in paired forR and forS fights 3) that foraging alleles from the forR and forS strains have similar effects on aggression in F1 heterozygotes and 4) that increased expression of the foraging gene in aggression-associated cells fails to increase aggression levels in the forS strain.
The Effects of Food Availability on Body Condition and Dispersal in the Backswimmer, Notonecta undulata
Keywords: behaviour
dispersal
Notonecta
physiological condition
predation

Dispersal is the movement of organisms across space that has the potential to cause gene flow. It therefore has important implications for ecological and evolutionary processes. Previous studies have demonstrated that dispersal is influenced by body condition; however, the results of these studies have been inconsistent with respect to the direction of this relationship. I asked whether predation risk interacts with condition to cause variable effects on dispersal. I tested this by imposing diet treatments on backswimmers (Notonecta undulata) in the laboratory. I measured the effects of food availability on condition. I then measured the effects of condition and predators on dispersal in a field experiment. I found that dispersal was a positive function of both body condition and predation risk. However, their effects were additive, not interactive.Therefore, the interaction between condition and predation risk is likely not contributing to the inconsistency in the results of condition-dependent dispersal studies.
Vitamin D and Type 2 Diabetes Mellitus in an Aboriginal Community
Keywords: 25(OH)D
Aboriginal
beta cell dysfunction
insulin resistance
metabolic syndrome
type 2 diabetes

Both vitamin D deficiency and type 2 diabetes mellitus (T2DM) are highly prevalent among the Aboriginal Canadian population. Emerging evidence suggests that vitamin D may be associated with T2DM, however current data are inconsistent. The objectives of this thesis were to investigate the associations of total, bioavailable and free 25(OH)D with insulin resistance (IR), β-cell dysfunction and the metabolic syndrome (MetS) in an Aboriginal community. The study included individuals from the Sandy Lake Health and Diabetes Project, a population-based cohort of individuals at high risk of T2DM. Lower serum total and bioavailable 25(OH)D were cross-sectionally associated with greater IR and poorer β-cell function. Also, lower serum total 25(OH)D was associated with a greater prevalence of the MetS and its components. Future carefully designed randomized controlled trials are required to determine whether vitamin D supplementation can reduce the burden of T2DM and MetS in the Aboriginal population.
Microbial Community Structure and Function in Coarse Woody Debris and Boreal Forest Soils after Intensified Biomass Harvests
Keywords: Biomass Harvesting
Boreal
Coarse woody debris
Ecology
Forestry
Microbial ecology

Intensified biomass harvesting could prove to be negative for forest ecological health through the impacts this type of forest management could exert on microbial community structure and function in forest soils and in CWD pools. Microbial community functional characteristics as well as community structure (through T-RFLP and pyrotag sequencing of ssu rRNA) were assayed soils in a boreal jack pine forest exposed to a clearcut intensified harvesting gradient. Microbial communities within CWD of various decay stages were also assessed in order to determine habitat specificity of the decomposer communities within them. Soil microbial communities were altered by harvesting, but intensification did not cause further disturbance. Soils in harvested sites were different from fire sites also assayed, meaning that these disturbance types may have different impacts on microbial community structure and functioning. CWD communities within logs had different characteristics in different sites. Intensification could reduce site specific organisms important in decay initiation.
ECG Biometrics using Intuitive Bases and Support Vector Machines
Keywords: biometrics
electrocardiogram
intuitive
single arm

In this thesis, a parts-based intuitive customized basis has been proposed using the non-negative sparse coding method for feature templates of the electrocardiogram(ECG) signal for biometrics. Combining with two classifier choices, two algorithms are proposed with complexity considerations for practical application scenarios using dependent classification.Using the proposed methods, a large scale fingertips ECG database was evaluated for biometrics potential, while observing the effect of user population size variation. The lowest known equal error rate (EER) for large-scale ECG biometrics was reported, which is 2.59% for 1012 users.Two unprecedented databases containing signals from a single arm were collected and analysed for biometrics application, following evidence of ECG pulses in the upper left arm. They reported encouraging EERs, based on the proposed methods. Best EERs obtained were 3.26% in the single-lead, and 6.97% for the multiple-lead signals, both for `sitting' posture.
Theory versus Practice: Conceptions of the University and Contemporary Challenges
Keywords: Entrepreneurial
John Dewey
Liberal
Research
Universities

The tension between thought and practice is an ancient one in Western societies. Universities, as institutions of learning, have been at the centre of this tension since their inception. In the first chapter I trace the history of the university, noting shifts in their tendency to dedicate their activities to thought or to practice, describing the present situation as another shift toward practice. In the second chapter, I examine three conceptions of a university--liberal, scientific, and economic--which are current in the present debate over the university's purpose. In the third chapter, I describe the philosophical division of theory and practice, and how a tendency to divorce the two relates to the three conceptions of a university. Using the philosophy of John Dewey, I argue that a divorce of the two is unsupportable, and propose a Deweyan idea of the university that addresses the contemporary problems described earlier.
An Advanced Time Averaging Modelling Technique for Power Electronic Circuits
Keywords: converter
exact
model
modeling
modelling
PWM

For stable and efficient performance of power converters, a good mathematical model is needed. This thesis presents a new modelling technique for DC/DC and DC/AC Pulse Width Modulated (PWM) converters. The new model is more accurate than the existing modelling techniques such as State Space Averaging (SSA) and Discrete Time Modelling. Unlike the SSA model, the new modelling technique, the Advanced Time Averaging Model (ATAM) includes the averaging dynamics of the converter's output. In addition to offering enhanced model accuracy, application of linearization techniques to the ATAM enables the use of conventional linear control design tools. A controller designapplication demonstrates that a controller designed based on the ATAM outperforms one designed using the ubiquitous SSA model. Unlike the SSA model, ATAM for DC/AC augments the system's dynamics with the dynamics needed for subcycle fundamental contribution (SFC) calculation. This allows for controller design that is based on an exact model.
Interferometric Distributed Fiber Optic Sensing
Keywords: Fiber optics
Fiber optic sensing
Multiplexing

This thesis studies single-arm frequency-shifted interferometry (SA-FSI), a simple, compact, practical and versatile fiber optic sensing technique which has many advantages over conventional techniques. We further developed the theory of SA-FSI, and successfully demonstrate that SA-FSI can achieve long distance and high sensitivity sensing multiplexing.In this thesis work, we also build a model of the working principle of a distributed vibration sensing system developed by QPS Photronics Inc., and explore its sensing features. Three different types of reflective terminations (a QPS VibroFibre sensor, a flat end fiber, and a loop mirror) have been used in our experiments. Experimental results for these three reflective terminations are consistent with simulation results based on our model.