VictorJuiz/thesis huggingface dataset:
Evanescent Photosynthesis: A New Approach to Sustainable Biofuel Production
Keywords: optofluidics
bioenergy
optofluidic
biofuel
cyanobacteria
microalgae
alternative energy
solar fuel
evanescent
microfluidics

Immobilization of photosynthetic cultures has been used to generate biofuels and high value compounds through direct conversion of CO2 and water using sunlight. Compared with suspended cultures, immobilized bacteria can achieve much higher densities resulting in greater areal productivity. Limitations exist however, on the density that can be reached without compromising access to light and other nutrients. In this thesis an optofluidic approach to overcoming the challenge of light delivery to high density cultures of cyanobacteria is described and proof of concept experiments presented. This approach uses optical waveguides to deliver light to cells through bacterial interaction with the evanescent field and is tailored to meet each cell's need for light and nutrients. Experiments presented here demonstrate biofilm proliferation in the presence of evanescent fields. Illumination of surfaces by surface plasmon enhanced evanescent fields is also shown to be an effective and potentially useful technique to grow biofilms within optofluidic architectures.
Receptivity of Laminar Boundary Layers to Spanwise-periodic Forcing by an Array of Plasma Actuators
Keywords: plasma actuator
transition
transient growth
laminar
boundary layer
streaks
power consumption
wind tunnel
turbulence
hot-wire
anemometry
disturbance velocity
power spectrum
nanofabrication
data collapse
electrode geometry

This work is concerned with the response of a Blasius boundary layer to dielectric-barrier-discharge (DBD) plasma actuators for the purpose of using these devices in bypass transition control. The plasma actuators consist of a spanwise-periodic array of high voltage electrodes, which are oriented to produce streamwise vortex pairs. The structure of actuator-induced streaks is measured using hot-wire anemometry over a streamwise distance of approximately 100 boundary layer thicknesses, and is decomposed into 4 spanwise Fourier modes. The modal content and corresponding streamwise growth characteristics are discussed for ten plasma actuator geometries over multiple excitation voltages and freestream velocities. Actuator power consumption was found to control the streak amplitude, whereas freestream velocity affected both amplitude and streamwise extent of the streaks. A common relationship between disturbance energy and power consumption was found among actuators of different dielectric thickness and similar electrode geometry.
What’s Stopping Us? Identifying Barriers to the Local Food Movement Using Ontario, Canada as a Case Study
Keywords: local food
barriers
food systems

The local food movement has been offered as an alternative to the conventional food system. This thesis identifies the barriers that are constraining the local food movement using the case study of Ontario, Canada, by performing qualitative analysis of informal interview responses. In addition to generating a comprehensive account of the barriers constraining local food, barriers to local food procurement in the institutional context are also identified. Findings suggest that the barriers to the local food movement can be related to a lack of access, lack of resources, poor governance structures, poor information sharing and uncooperative relationships between local food actors. I argue that these barriers are reflective of the broader challenges associated with attempting to create food systems change from within the dominant system. Daunting as they may be, they can be overcome in an incremental, pragmatic way. Nineteen recommendations are made to this end.
Institutional Assessment as an Agent of Reform: An Analysis of Nigerian Legal Education
Keywords: Institutional Assessment
Reforms

The quality of Nigerian Legal Education is fast deteriorating and in addition, the current structure of monitoring the training of lawyers is grossly ineffective. This thesis discusses steps that can be taken in reforming the current structure of Nigerian legal education to revert this trend. This thesis proposes a sytem of internal institutional assessment by law faculties in Nigeria. Financial, social-cultural constraints and politicl economy interference are obstacles to reforming Nigerian legal education, but institutional assessment can mitigagte these obstacles. Using Mariana Prado's concept of institutional bypass as a solution to overcoming these obstacles and also as a means of advancing reforms in the training of lawyers in Nigeria, this thesis proposes the adoption of institutional assessment as a strategy to create an avenue for stimulating reforms and promoting quality in Nigerian legal education.
Design and Development of a Direct-acting Piezoelectric Fuel Injector
Keywords: Piezoelectric
Fuel injector
Diesel Engine

Manufacturers face the challenge of enhancing fuel efficiency, engine performance, and reducing harmful emissions. Novel fuel injection technologies can assist in meeting such demands. This dissertation summarizes the stages in the design, prototyping and experimental analysis of a direct-acting piezoelectric fuel injector concept. In the proposed design, a piezoelectric stack actuator is used to directly control the injection of fuel in order to enhance the injection characteristics by utilizing the fast response time of the actuator. The direct-acting concept was implemented by developing a motion inverter in the form of a disc that reverses the direction of the input and allows the actuator to directly control injections. Tests with input signals similar to those used in diesel engines confirmed the theoretical calculations and verified the prototype’s performance. This design can control the quantity of injected fuel more precisely than currently available commercial injectors.
Thresholds of Engagement: Integrating Image-based Digital Resources into Textual Scholarship
Keywords: image-based humanities computing
book history
textual scholarship
bibliography
web design
digital facsimile

In recent years, technological advances in creating, storing, and accessing digital facsimiles of print and manuscript documents has resulted in an explosion of digitization initiatives. While such initiatives commonly endorse the viewpoint that digital facsimiles either replace or successfully stand in for their physical originals, textual scholars, whose principle interest is in the text as material artifact, do not share this perspective. Thresholds of Engagement explores the ways textual scholars engage with textual artifacts, tests the limits of representation of digital facsimiles and of the interfaces that house them, and proposes a model for the relationship between physical texts and their digital counterparts that privileges the requirements of textual scholars. The digital-facsimile interface proposed in this study is designed to facilitate methods described by textual scholars in interview—methods of comparison, material analysis, pattern recognition, and modelling—using an open-source web-based approach that is accessible for individuals to innovate and build upon.
Numerical Modelling of Staged Combustion Aft-injected Hybrid Rocket Motors
Keywords: Computational Fluid Dynamics
Turbulent Combustion
Hybrid Rocket Motors
Numerical Modelling

The staged combustion aft-injected hybrid (SCAIH) rocket motor is a promising design for the future of hybrid rocket propulsion. Advances in computational fluid dynamics and scientific computing have made computational modelling an effective tool in design and development. The focus of this thesis is the numerical modelling of the SCAIH rocket motor in a turbulent combustion, high-speed, reactive flow accounting for solid soot transport and radiative heat transfer. The SCAIH motor has a shear coaxial injector with liquid oxygen injected centrally at sub-critical conditions: 150K, 150m/s (Mach≈0.9), and a gas-generator gas-solid mixture of one-third carbon soot by mass injected in the annual opening at 1175K, and 460m/s (Mach≈0.6). Flow conditions in the near injector region and the flame anchoring mechanism are of particular interest. Overall, the flow is shown to exhibit instabilities and the flame is shown to anchor directly on the injector faceplate with temperatures in excess of 2700K.
Role of the Ventral Hippocampus in Exploration and Ventral Hippocampal Parvalbumin Neurons in Behaviors relevant to Schizophrenia
Keywords: ventral hippocampus
exploration
parvalbumin
optogenetics
DREADD

We conducted experiments to understand the role of Ventral Hippocampus (vHPC) projections to the Nucleus Accumbens (NAc) in exploratory locomotion, and to determine if the reduced vHPC parvalbumin neuron activity can result in behaviors associated with schizophrenia. Through the use of optogenetics, we activated vHPC neurons and vHPC terminals in the NAc. Both manipulations significantly increased locomotor activity in the open field. Selective inhibition of vHPC terminals in the NAc during a test for novel environment exploration significantly reduced preference for novel environments over familiar environments. DREADD-mediated inhibition of activation of vHPC parvalbumin neuron activity did not significantly alter amphetamine-induced locomotion. Overall, these experiments provide support for the role of the vHPC-NAc pathway in mediating exploratory behavior in novel environments, but it remains inconclusive whether dysregulated vHPC activity due to the loss of parvalbumin neurons leads to behaviors associated with schizophrenia.
Concurrent Individual and Social Learning in Robotic Teams
Keywords: Cooperative Learning
Multi-Robot
Individual Learning
Advice Sharing

Despite the advancement of research and development on multi-robot teams, a key challenge still remains as to how to develop effective mechanisms that enable the robots to autonomously generate, adapt, and enhance team behaviours while improving their individual performance simultaneously. After a literature review of various multi-agent learning approaches, the two most promising learning paradigms, i.e., cooperative learning and advice sharing are adopted for future development. Although individually these methodologies may not provide a solution, their proper integration will provide a platform that allows for the incorporation of multi-agent learning with social behaviours. These methods are examined in relation to the performance characteristics of single-robot learning to ascertain if they retain viable learning characteristics despite the integration of individual learning into team behaviour. Further, various modifications to the Q-Learning algorithm were tested, and the best performing modification was implemented into the proposed multi robot learning approach.
Punching Shear Behaviour of Thick Reinforced Concrete Slabs
Keywords: Concrete
Punching
Shear
Slabs
Strut-and-tie
punching shear
Reinforcement ratio
column size
ACI 318
CSA A23.3
2010 Model Code
structures
deep
thick

Experiments were conducted to investigate the punching shear behaviour of thick slabs with identical spans and depths, subjected to monotonic point load conditions. Variables included: reinforcement ratio, column size, and reinforcement size. Analytical studies conducted as part of this thesis indicate that the current CSA A23.3 and the ACI 318 can be unconservative for thick slabs with low reinforcement ratios. The new fib Model Code provisions for punching offer an effective method for determining the full load-rotation behaviour of a slab up to failure, including accurate failure predictions. A summary of the background of current design procedures and standards will be presented, and a comparison between the different design equations and theories will be given. Based on the findings of this project, it is proposed that the provisions accepted by the fib Model Code should be considered for implementation in the CSA and ACI standards.
Goal Structuring of a Knowledge Domain
Keywords: knowledge management
goal oriented requirements engineering
design reuse
goal structuring
classification
technology domain

This thesis aims to develop a knowledge structuring framework to organize knowledge according to means-ends relationships. Means-ends relationships are particularly relevant in technology and goal-oriented domains such as the geo-engineering domain, where technical problems are identified, and solutions proposed. The proposed goal oriented representation in this thesis does not replace current classification methodologies. In this project, a small corpus of research publications from a technology domain is used to help construct the framework. The main means-ends relationships from the articles are manually extracted and represented in a graphical model showing which problems are approached, by which solutions proposed, and in which publications. Proposed solutions can lead to new problems which are in turn addressed by solutions proposed in other publications. A metamodel is derived to capture the important concepts and relationships relevant for this purpose. The metamodel, and the framework have undergone several iterations before finalization.
A Preliminary Exploration of Memory Controller Policies on Smartphone Workloads
Keywords: smartphone workloads
workload characterisation
memory controller
main memory
DRAM
address mapping
memory scheduler
memory performance

This thesis explores memory performance for smartphone workloads. We design a Video Conference Workload (VCW) to model typical smartphone usage. We describe a trace-based methodology which uses a software implementation to mimic the behaviour of specialised hardware accelerators. Our methodology stores dataflow information from the original application to maintain the relationships between requests. We first study seven address mapping schemes with our VCW, using a first-ready, first-come-first-served (FR-FCFS) memory scheduler. Our results show the best performing scheme is up to 82% faster than the worst. The VCW is memory intensive, with up to 86.8% bandwidth utilisation using the best performing scheme. We also test a Web Browsing and a set of computer vision workloads. Most are not memory intensive, with utilisation under 15%. Finally, we compare four schedulers and find that the FR-FCFS scheduler using the Write Drain mode [8] performed the best, outperforming the worst scheduler by 6.3%.
The Role of the Ubiquitin Ligase Nedd4-1 in Skeletal Muscle Atrophy
Keywords: Nedd4
skeletal muscle
skeletal muscle atrophy
Ubiquitin ligase

Skeletal muscle (SM) atrophy complicates many illnesses, diminishing quality of life and increasing disease morbidity, health resource utilization and health care costs. In animal models of muscle atrophy, loss of SM mass results predominantly from ubiquitin-mediated proteolysis and ubiquitin ligases are the key enzymes that catalyze protein ubiquitination. We have previously shown that ubiquitin ligase Nedd4-1 is up-regulated in a rodent model of denervation-induced SM atrophy and the constitutive expression of Nedd4-1 is sufficient to induce myotube atrophy in vitro, suggesting an important role for Nedd4-1 in the regulation of muscle mass. In this study we generate a Nedd4-1 SM specific-knockout mouse and demonstrate that the loss of Nedd4-1 partially protects SM from denervation-induced atrophy confirming a regulatory role for Nedd4-1 in the maintenance of muscle mass in vivo. Nedd4-1 did not signal downstream through its known substrates Notch-1, MTMR4 or FGFR1, suggesting a novel substrate mediates Nedd4-1’s induction of SM atrophy.
Cocaethylene as a Biomarker in Human Hair of Concomitant Alcohol and Cocaine Use in a High-risk Population
Keywords: Clinical
Pharmacology
Hair
Testing
Cocaine
Alcohol
Concomitant
Consumption
High-Risk
Population
Fatty Acid Ethyl Esters
Cocaethylene

Cocaethylene (CE) is a cocaine metabolite formed during alcohol and cocaine co-consumption. To our knowledge, no previous studies were conducted assessing CE as a biomarker indicating chronic excessive alcohol consumption in a suspected high-risk population. In this study, we hypothesized that hair CE can be an effective marker for alcohol consumption in a high-risk population. We recorded cocaine, benzoylecgonine, and CE levels in hair samples from individuals, establishing the predictive value of CE by comparing it to hair levels of the widely used hair fatty acid ethyl esters (FAEE), direct markers of chronic excessive alcohol consumption. CE had 14.04% sensitivity and 95.18% specificity in samples separating FAEE positive/negative results. The positive predictive value was 0.66, showing that the results for individuals with CE positive results were more than likely to be FAEE positive, but not conclusively. Thus, CE cannot be used as a definitive marker, indicating chronic excessive alcohol consumption.
Leveling of the Curve of Spee in Deep Overbite Cases Treated with the IncognitoTM Lingual Orthodontic Appliance System: A Cephalometric Study
Keywords: curve of Spee
overbite
Incognito
intrusion

An excessive curve of Spee (COS) is a common orthodontic finding, particularly in patients with a deep overbite (OB). The purpose of this analysis was to evaluate COS leveling and OB correction in patients treated with IncognitoTM, a customized lingual appliance system. Pre- and post-treatment cephalometric radiographs were compared for 34 patients with a deep OB and excessive COS treated with IncognitoTM. The mean pre- and post-treatment COS was 1.78 mm (SD: 0.36 mm) and 0.37 mm (SD: 0.41 mm) respectively, indicating a significant amount of leveling (-1.41 mm, SD: 0.49 mm, p<0.001). The mean pre- and post-treatment OB was 5.80 mm (SD: 1.26 mm) and 2.91 mm (SD: 0.86 mm) respectively, demonstrating a significant reduction in OB (-2.89 mm, SD 1.27 mm, p<0.001). COS and OB correction was accomplished by incisor proclination, and a greater (but not significantly different) amount of mandibular incisor intrusion versus premolar and molar extrusion.
Impact of Clostriduim difficile colitis on Five Year Health Outcomes of Ulcerative Colitis Patients
Keywords: Inflammatory bowel disease
Ulcerative colitis
Clostridium difficile
Colectomy
Mortality
Hospitalization
Prognosis
Population-based study
Health Outcomes
Epidemiology

Clostridium difficile colitis (CDC) is associated with a higher risk of acute death among hospitalized ulcerative colitis (UC) patients. However, the risk of colectomy with CDC in these patients has varied across studies. No study has assessed the long-term health impact of CDC in UC patients. Therefore, the present study evaluated the impact of CDC on five-year health outcomes of hospitalized UC patients based on Ontario health administrative data. No overall association was observed between CDC and five-year risks of colectomy or death in overall cohort. However, patients who were discharged from hospital without undergoing colectomy demonstrated marginally higher five-year risks of colectomy and hospital re-admission. Mortality risk and length of stay during index hospitalization were also higher in patients with CDC. Analysis of a parallel cohort of UC patients derived using a published case definition corroborated most of these results, but demonstrated a higher five-year mortality risk with CDC.
Access to Colorectal Cancer Screening in Canada: Does Immigrant Status Matter
Keywords: access
colorectal
screening
immigrants

Background: In 2010, immigrants comprised 20% of the Canadian population. Canada has one of the highest incidence and mortality rates of colorectal cancer (CRC) in the world. This study seeks to explore factors that are associated with CRC screening and to determine whether immigrants are less likely to be screened for CRC compared to non-immigrants. Methods: Data were obtained from Statistics Canada Canadian Community Health Survey, 2008. The Behavioral Model of Health Services Use was used as a theoretical framework. Chi-square statistics and multiple logistic regression models were employed. Results: Recent immigrants were less likely to be screened by endoscopy within 5 years (OR: 0.47; 95% CI: 0.29 – 0.77), endoscopy within 10 years (OR: 0.38; 95% CI: 0.24 - 0.60) and be up-to-date with screening (OR: 0.58; 95% CI: 0.37 - 0.91) compared to non-immigrants. Conclusions: A formal screening program and patient navigators may address disparities among recent and non-immigrants.
Assessment of Intestinal Microbiota in Non-alcoholic Fatty Liver Disease
Keywords: fatty liver
intestinal microbiota

Non-alcoholic fatty liver disease (NAFLD) includes simple hepatic steatosis (SS) and non-alcoholic steatohepatitis (NASH). NAFLD is tightly linked to obesity and is thought to be secondary to various noxious signals, some of which may originate from the intestinal microbiota (IM). Despite a growing body of evidence supporting a link between obesity and altered IM, there are no studies assessing the IM of patients with NAFLD. In this cross-sectional study we aimed at comparing fecal levels of total bacteria, Bacteroidetes, C. coccoides, C. leptum, Bifidobacteria, E. coli, and Archaea between healthy controls (HC) and patients with SS or NASH. We found higher C. coccoides levels in NASH compared to SS and lower percentage Bacteroidetes in NASH compared to SS and HC. Controlling for body mass index and fat intake we found an association between presence of NASH and percentage Bacteroidetes. The latter inversely correlated with insulin resistance.
A Journey down the Cell Death Pathway of Mitochondria-targeted Chlorambucil
Keywords: Mitochondria
Cancer
Mitochondria Penetrating Peptide
Chlorambucil
Cell Death
Necrosis

Our lab recently demonstrated that retargeting an alkylating agent, chlorambucil (Cbl), to the mitochondrion is a viable strategy to restore drug activity and overcome drug resistance in cancer. The mechanism of action of the mitochondria-targeted chlorambucil (mt-Cbl) was studied using a cervical carcinoma model. It was discovered that mt-Cbl bound to mitochondrial DNA and various mitochondrial proteins. A ρ° model revealed that the toxicity of mt-Cbl is largely dependent on its protein targets. Damage induced by mt-Cbl was found to result in the activation of several modes of caspase-independent cell death including necrosis. In contrast, Cbl was found to only activate caspase-dependent cell death that is highly sensitive to caspase inhibition. These results illustrate that the ability of mt-Cbl to activate various orthogonal cell death pathways is what allows mt-Cbl to bypass several drug resistance mechanisms, thus making mitochondrial retargeting a lucrative strategy for future anticancer drug development.
Anti-CD44 and Anti-platelet Antibodies have Similar but Distinct Effects in the Treatment of a Mouse Model of Arthritis
Keywords: Rheumatoid Arthritis
CD44
Platelets
Thrombocytopenia

Rheumatoid Arthritis (RA) is an autoimmune disease characterized by inflammation and eventual destruction of the synovial joints. The role of platelets in the pathophysiology of arthritis has only recently been established. Because antibodies to CD44 can deplete platelets, we hypothesized that these antibodies might be effective in arthritis through a platelet-depletion mechanism. We examined the K/BxN passive transfer mouse model of arthritis and found that most antibodies against CD44 were capable of depleting platelets. However, anti-CD44 treatment is effective when administered during developing arthritis, while anti-platelet treatment was not. While CD44 antibodies may be therapeutic through platelet-dependant and independent mechanisms, the ability of CD44 antibodies to decrease platelet counts does not seem to be the critical factor in resolving arthritis in the K/BxN model.