VictorJuiz/thesis huggingface dataset:
Drag on a Cylinder in a Viscoelastic Stokes Flow
Keywords: Fluid Mechanics
Stokes Flow
Non-Newtonian
Viscoelastic
Boger Fluids
Cylinder Drag

This thesis reports on measurements of drag on an unbounded cylinder in a viscoelastic Stokes flow, and compares these values with a Newtonian equivalent. Cylinders of diameter 0.5 to 3.34 mm were submerged 10 to 36 mm into slowly rotating annular tanks with channel widths between 133 to 152 mm. Theoretical formulas and computer simulations were used to correct for the effects of ends and walls, yielding estimates of the unbounded drag. The methodology was verified by testing Newtonian fluids and comparing the results to Kaplun’s (1957) prediction for unbounded drag. The test fluids used were a silicone oil, a polybutene, and two Boger fluids. By comparing the Boger fluid results to equally viscous Newtonian results, the contributions of elasticity to the drag were determined. The Deborah number (De) was used to represent the magnitude of flow elasticity, and an onset of elastic effects was measured between 0.5 and 0.7.
Inhibition of TDP-43 Aggregation using Native State Binding Ligands
Keywords: TDP-43
protein aggregation
protein misfolding
native state stabilization
ALS
FTLD
aggregation inhibition

TAR DNA binding protein of 43 kDa (TDP-43) has been implicated in the pathogenesis of amyotrophic lateral sclerosis and frontotemporal lobar degeneration. Pathologically misfolded and aggregated forms of TDP-43 are found in cytoplasmic inclusion bodies of affected neurons in these diseases. The mechanism by which TDP-43 misfolding causes disease is not well understood. We postulate that the aggregation process plays a major role in pathogenesis, and we hypothesize that oligonucleotide ligands of TDP-43 can stabilize the native functional state of the protein and ameliorate aggregation of this aggregation-prone protein. Using recombinant TDP-43 we were able to examine the extent to which various oligonucleotide molecules affects its aggregation in vitro. We have found that certain natural sequence and de novo designed oligonucleotides bind TDP-43 and prevent its natural tendency to aggregate. The clinical and therapeutic implications of these findings are discussed.
Prairie Freigeld: Alberta Social Credit and the Keynesian Frontier of Monetary Economic Thought in North America, 1929-1938
Keywords: Human geography of money
Social neutrality
Alberta Social Credit
Canadian history
History of economic thought
Keynesian theory
Circuit theory
Post-capitalism

This thesis examines the impact of Social Credit in North America during the Great Depression as a social philosophy and approach to government. By placing Social Credit in the context of interwar social movements for monetary reform, the events in Alberta from 1932 to 1938 are examined from the historical geographic iteration of what I call the Keynesian frontier of monetary macro-economic thought. This thesis shifts attention on this episode of Canadian history towards the lens of monetary neutrality. I argue that the Keynesian frontier was the intellectual environment for a worldwide English- speaking progressive underground which sought to find in macro-economic theory a vision of utopian society where money had no effect on material choices and interpersonal relations. During the 1930s, movements such as Social Credit transformed this underground into a collective effort to integrate the institutional channels of circulation with the mechanics of the modern monetary and fiscal state.
Multi-Camera Active-vision System Reconfiguration for Deformable Object Motion Capture
Keywords: Robot vision
Intelligent systems

To improve the accuracy in capturing the motion of deformable objects, a reconfigurable multi-camera active-vision system which can dynamically reposition its cameras online is proposed, and a design for such a system, along with a methodology to select the near-optimal positions and orientations of the set of cameras, is presented. The active-vision system accounts for the deformation of the object-of-interest by tracking triangulated vertices in order to predict the shape of the object at subsequent demand instants. It then selects a system configuration that minimizes the expected error in the recovered position of each of these vertices. Extensive simulations and experiments have verified that using the proposed reconfigurable system to both translate and rotate cameras to near-optimal poses is tangibly superior to using cameras which are either static, or can only rotate, in minimizing the error in recovered vertex positions.
Exploring a New Methodological Approach for Capturing the 'Slowing Down' Moments of Operative Practice
Keywords: surgical education
expertise
judgment

The phenomenon of 'slowing down' in response to important cues in the operative field is proposed as a hallmark of expert surgical judgment. As part of a larger program of research, the purpose of this study was to explore a methodology for capturing 'slowing down' moments using a standardised task. Edited videos of 6 laparoscopic cholecystectomies were shown to 10 expert surgeons (>250 laparoscopic cholecystectomies completed). Participants were asked to think aloud while watching them as if observing each procedure in the operating room. Each session was audiotaped and transcribed. Many examples of 'slowing down' moments were identified in the transcripts, including several categories that were previously uncharacterised or undescribed. A subset of 'slowing down' moments was compared between participants. Many appeared to be inconsistent between expert surgeons, suggesting that with this methodology alone, formal teaching and assessment of the 'slowing down' phenomenon will be challenging.
Generation of High-Ni sulfide and Alloy Phases during Serpentinization of the Dumont Dunite, Quebec
Keywords: Ultramafic Nickel
Serpentinization

The Dumont Sill in the Abitibi, Quebec, is broadly zoned from gabbroic chilled margins through peridotite to a principally dunitic core. The dunite contains several layers enriched in primary sulfide minerals. Serpentinization occurred isochemically with respect to major components apart from the addition of H2O. An extensive database which includes 1420 mineralogical samples and 4400 microprobe analyses has been used to understand alteration and nickel deportment in primary and secondary minerals. In layers containing primary accumulations of magmatic sulfide serpentinization has resulted in the remobilization of nickel from olivine to enrich cumulus sulfides. In layers lacking primary sulfide accumulations, serpentinization was accompanied by the formation of awaruite. Assemblages which are completely serpentinized contain lesser nickel in silicates, higher nickel tenor sulfides, and more modal awaruite compared to those which are weakly and partially serpentinized, which are characterized by higher nickel in silicates and lower Ni tenor sulfides.
The Sustainability and Long-term Outcomes of Knowledge Translation Projects: A 3-year Follow-up of the GAIN Collaborative Network Project
Keywords: Health care program sustainability
Sustainability
Program Development - methods
Program Evaluation - methods
Community Health Services
Mental Health screening
Concurrent disorder screening

Objective: This thesis aimed to advance the study of sustainability through the exploratory use of a conceptual framework for the investigation of a collaborative project. Methods: A qualitative case study design, utilizing document analysis and key informant interviews, was used to conduct a three-year follow-up of a collaborative mental health project. The study design and directed content analysis were informed by the Scheirer and Dearing (2011) conceptual framework. Results: The sustained outcomes identified by the six participating agencies included: institutionalized project components, maintained client benefits, continued collaboration and sustained attention to the issue. The sustainability of project components was associated with complex interactions between the innovation, organization, and community factors investigated. Conclusions: The study illustrated the importance of evaluating multiple aspects of sustainability to fully capture a project’s long-term effect. Complex systems theory was proposed to describe the interactions observed and as a direction for further development of the conceptual framework.
The Fifth Pathway to Forest Transition in the Andes: Modeling Factors That Influence Smallholder Tree Planting in Mocoties, Venezuela
Keywords: smallholder, tree planting,agroforestry, reforestation

Smallholder tree planting is a pathway recognized within Forest Transition Theory (FTT), but its contributing factors are not fully explored at the household level. This study examines the effect of socio-economic and biophysical characteristics, access to extension services, land tenure, labour availability, and attitudes toward tree cover on smallholder planting and willingness to plant for environmental and economic purposes at the household level. Data was collected from 146 households in Mocoties, Merida, Venezuela. Logistic models revealed that area of property, area of productive land, presence of natural sources of water, gender of respondent, number of generations that have farmed the property, income, percent income from farming activities, land title, harvest rights, labour availability and attitudes toward tree cover have significant influence on smallholder’s tree planting and willingness to plant. Future research needs to focus on factors that affect environmentally motivated smallholder tree planting where fewer significant variables were found.
Identification and Characterization of Novel CYP2A6 Variants in African American Slow Nicotine Metabolizers
Keywords: Pharmacogenetics
Nicotine metabolism
CYP2A6
Genetic variation
Smoking
African Americans
Smoking cessation

Nicotine, the main addictive compound in tobacco, is metabolically inactivated to cotinine primarily by the hepatic enzyme CYP2A6. Substantial genetic variation in the CYP2A6 gene contributes to large variation in nicotine metabolism which alters numerous smoking behaviours. The goal of this study was to identify and characterize novel CYP2A6 variants. The CYP2A6 gene from African American phenotypically slow nicotine metabolizers was sequenced. Seven novel non-synonymous variants were identified: 468G>A (V68M), 1767C>G (I149M), 3515G>A (R265Q), 3524T>C (I268T), 4406C>T (T303I), 5661G>A (E390K), 6531T>C (L462P). They were introduced into a cDNA expression construct where they displayed lower protein expression, reduced nicotine metabolism to cotinine, and/or reduced stability as evaluated by western blotting and enzymatic activity. Genotyping assays were developed and assessed in 512 African Americans. Allelic frequencies ranged from 0.1-0.6% with a collective genotype frequency of 3.2%. Here we identified novel variants with reduced/loss of CYP2A6 activity, increasing our understanding of CYP2A6 variability.
The Effects of a Neutral Cannabinoid-1 Receptor Antagonist on Intravenous Nicotine Self Administration Behaviour
Keywords: nicotine
self administration
tobacco dependence
cannabinoid 1 receptor
CB1 receptor neutral antagonist
AM4113

Introduction: Tobacco dependence is a chronic disorder that carries the risk of relapse at any time point during abstinence. It is a major health issue in the world and current pharmacotherapies have had limited efficacy. Therefore, development and validation of novel treatments are required. Objective: Investigate the novel neutral cannabinoid-1 receptor antagonist AM4113 on nicotine (main psychoactive ingredient in tobacco)-taking behaviour in animals. Methods: Using the nicotine intravenous- and food control- self administration paradigms, we tested the acute and chronic (10-days) effects of AM4113 on nicotine- and food-taking behaviour. Results: Acute AM4113 treatments (1-, 3-, 10-mg/kg) reduced nicotine self administration. Chronic AM4113 administration (10mg/kg) produced a sustained reduction of nicotine-taking behaviour during the course of the treatment. In the similar food control self administration experiments, AM4113 overall produced no effect. Conclusion: AM4113 can attenuate nicotine-taking behaviour and its effect is sustained under chronic treatment.
Integrated Genomic Analyses of Childhood Central Nervous System-Ppimitive Neuro-ectodermal Tumours (CNS-PNETs)
Keywords: Primitive Neuro-ectodermal Tumours
LIN28
OLIG2
CNS-PNET

CNS-PNETs are rare, aggressive, paediatric embryonal brain tumours that are poorly studied. We recently identified an aggressive sub-group of CNS-PNETs characterized by the amplification of the C19MC microRNA cluster, however, little is known regarding the features of other CNS-PNET tumours. This study was designed to define additional molecular sub-groups of CNS-PNET by interrogating a large cohort of CNS-PNETs. To elucidate the features of CNS-PNET, we examined transcriptional and copy number profiles from primary hemispheric CNS-PNETs. We then validated and examined the clinical significance of novel sub-group markers in 123 primary CNS-PNETs. This thesis demonstrates that CNS-PNET can be categorized into three molecular sub-groups that are distinguished by distinct primitive neural, oligo-neural and mesenchymal lineage gene expression signatures and also correlated with distinct clinical features. Data from my thesis has generated a substantial body of knowledge to fuel both biological and clinical investigations of childhood CNS-PNETs.
Pressures to 'Measure Up' in Surgical Training: Managing One's Impression and Managing One's Patient
Keywords: Medical Education
Surgery
Impression Management
Surgical Culture
Residency

The surgical culture values certainty and confidence, and this was proposed to be a source of internal conflict for surgeons, particularly during times of stress and uncertainty. Surgeons previously described the need to manage their image during these times, putting on an external appearance that is inconsistent internally. As part of a larger program of research on surgical judgment and decision making, this study used a constructivist grounded theory approach to explore 15 general surgery trainees’ perceptions and experiences of impression management during moments of decision making. Residents described their perceived expectations in training, and the impression management strategies they used to appear as though they were meeting them in circumstances when they were not. Participants described those who did not meet these expectations as branded the ‘struggling resident’. Concerns about one’s impression had implications for residents’ evaluations, learning opportunities, decision making, and wellness.
Assessing the Safety of Cholinesterase Inhibitor Discontinuation in Patients with Moderate to Severe Alzheimer’s Disease in a Long Term Care Setting
Keywords: Alzheimer's Disease
cholinesterase inhibitors
discontinuation
cessation
donepezil
rivastigmine
galantamine
ChEIs

Cholinesterase inhibitors (ChEIs) are the first line pharmacotherapy for the symptoms of Alzheimer’s disease (AD). Though ChEIs offer modest cognitive benefits in early AD, literature addressing their continued use in severe AD is scarce. This study assessed the safety of discontinuing ChEIs in institutionalized moderate-severe AD patients. Twenty-six patients were randomized, double-blind to ChEI continuation or placebo for 8-weeks. Vitals, weight (kg) and adverse events (AEs) were monitored biweekly. Chi-square test revealed no significant association between semi-blinded treatment allocation and AE occurrence (χ²=(1,26)=0.99, p=0.32). Groups showed no differences on clinically significant weight loss (χ²=(1,26) =1.9, p=0.17), mean weight loss (F=.531, p= .473), pulse rate (F=.624, p=.437), or side effects (F=.224, p=.640). Preliminary results suggest that either ChEIs are well tolerated or that these drugs are no longer providing therapeutic benefit. Study completion (recruitment of 60 patients and unblinding) will generate more comprehensive data for determination of safe ChEI discontinuation guidelines.
Dynamic Optimization Models for Ridesharing and Carsharing
Keywords: Ridesharing
Transportation

Collaborative consumption is the culture of sharing instead of ownership in consumer behaviours. Transportation services such as ridesharing, carsharing, and bikesharing have recently adopted collaborative business models. Such services require real-time management of the available fleets to increase revenues and reduce costs. This thesis proposes two dynamic models for real-time management of carsharing and ridesharing services. In ridesharing, an assignment problem is solved to match drivers with passengers. The model is expanded to include multi-passenger and multi-driver matches. In carsharing, vehicles are relocated between parking stations to service the users. Results of the two models are compared to benchmark models which provide lower-bound solutions.
Impact of Thermal Remediation on the Degradation of Naphthalene by Indigenous Anaerobic Bacteria in Hydrocarbon Contaminated Soil
Keywords: Bioremediation
Naphthalene Degradation

Thermal remediation is an efficient and cost effective method for the removal of organic compounds from the subsurface. However, complete removal of these compounds cannot be achieved by this technology alone. It is generally assumed that bioremediation will provide the polishing steps at thermally treated sites. In this study, soil was collected from a hydrocarbon contaminated site that previously underwent thermal remediation. A microcosm batch study was conducted to determine the impacts of thermal remediation on indigenous microorganisms and their ability to degrade naphthalene. Soils that reached varying peak temperatures were set up in microcosms at temperatures experienced along their respective cooling profiles. Naphthalene degradation was not detected within any of the unamended microcosms within a 6 month time frame, although, archaea growth was detected in the microcosms after 2 months of acclimation, accompanied by iron reduction and significant methane production assumed to have arisen from degradation of methanol.
Characterization of Breast Cancer with Manganese-enhanced Magnetic Resonance Imaging
Keywords: Cancer, MRI, Imaging

Highly metastatic cancer cells are more likely to escape and form metastases, and only minimal improvements in treatment can be achieved. Despite metas- tases being the primary cause of cancer-related mortality, they often proceed unnoticed. Current imaging modalities rely solely on the morphological fea- tures of the tumor for characterization, rather than cellular differences. Our goal is to develop an MR cellular imaging capability for characterizing the po- tential of breast cancer cells to metastasize and enable early cancer detection using manganese. Experiments on breast cell lines demonstrated that aggres- sive cancer cells significantly enhanced on T1 -weighted MR images as a result of a higher uptake and retention of manganese. These results suggest that dif- ferences in uptake of manganese can help the detection and characterization of breast cancers. The proposed technique can also be useful for other cancers, and could bring a critically needed dimension to cancer imaging.
Continuous Extrusion of Homogeneous and Heterogeneous Hydrogel Tubes
Keywords: Hydrogels
Extrusion
Mosaic soft materials

We present a platform that allows homogeneous and heterogeneous 3-D soft materials to be continuously defined in a single step. Biopolymer solutions are introduced to a microfluidic device and radially distributed to feed to a common outlet at the device center. This forms concentric sheaths of complex fluids and upon crosslinking, a hydrogel tube at the exit. This approach allows for the controlled and continuous extrusion of tubes with tailored diameters of 500 μm to 1500 μm, wall thicknesses of 20 μm to 120 μm, and compositions, as well as predictable mechanical and chemical properties. Using the same platform, single and multi-walled hydrogel tubes with defined heterogeneities and patterns of discrete spots of secondary biopolymer materials can be continuously extruded. A tube-hosting device is presented which can independently perfuse and superfuse isolated tube segments, allowing precise microenvironmental control without cannulation for up to an hour.
Methodology of Measuring Particulate Matter Emissions from a Gasoline Direct Injection Engine
Keywords: gasoline direct injection
particulate matter
ethanol
emissions
spark ignition
direct injection
GDI
SIDI
gasoline engine
E10
E0
E30

A gasoline direct injection engine was set-up to operate with a dynamometer in a test cell. Test cycle and emissions measurement procedures were developed for evaluating the regulated and non-regulated gaseous emissions. Equipment and techniques for particulate matter measurements were adapted for use with the gasoline direct injection engine. The particulate matter emissions produced by the engine were compared between two different fuels; gasoline and E10 (10% ethanol and 90% gasoline). The gaseous emissions generated by the engine when it was run on gasoline and E30 (30% ethanol and 70% gasoline) were also compared. Particle number decreased with E10 for hot start conditions, while the opposite was observed for cold start conditions. Particulate matter emissions were found to track with acetylene and ethylene emissions.
Mechanisms Underlying the Pathogenesis of Atrial Arrhythmias in RGS4-deficient Mice
Keywords: RGS proteins
atrial arrhythmias
KATP channels

Atrial arrhythmias are very common clinically relevant conditions that are strongly associated with aging and parasympathetic tone. Additionally, ATP-sensitive K+ (KATP) channel activation has been reported to facilitate the development of re-entrant atrial arrhythmias. Since KATP channels are direct effectors of Gαi/o and RGS4 is an inhibitor of Gαi/o-signaling, we here investigate whether KATP channel activity is increased under decreased RGS4 activity in a manner that enhances susceptibility to AF. We show that loss of RGS4 facilitates the induction of atrial arrhythmias under parasympathetic challenge both in whole animals and isolated atrial tissues. Furthermore, using both genetic disruption (Kir6.2 ablation) and pharmacologic blockade (tolbutamide), we show that loss of functional KATP channels decreases the incidence of pacing-induced re-entry and prolongs repolarization in RGS4-deficient atria. Our findings are consistent with the conclusion that enhanced KATP channel activity may contribute to pacing-induced re-entrant rotors in the RGS4-deficient mouse model.
Complex Phase Biasing of Silicon Mach-Zehnder Interferometer Modulators
Keywords: complex phase
Mach-Zehnder
MZI
MZM
phase bias
extinction ratio

A new any-point biasing scheme for Mach-Zehnder interferometer modulators which considers the complex phase is proposed. The Mach-Zehnder arm loss imbalance (imaginary part of the phase bias) is found by slightly perturbing the real and imaginary parts of the phase in each arm with low frequency pilot tones and monitoring and manipulating the spectral content at the output. This technique can be used to extend the possible extinction ratio, reduce the phase error, and better quantify the system chirp but also has some performance degradations which are also quantified and discussed. Simulation results indicate that the maximum extinction ratio of a typical modulator can be extended to ≳ 40 dB and maintained in the presence of ambient complex phase drift in the arms. Practical challenges for implementing this method with a silicon Mach-Zehnder modulator are discussed, but the analysis is general to other material platforms.