VictorJuiz/thesis huggingface dataset:
Impacts of Conservative Endodontic Cavity on Root Canal Instrumentation Efficacy and Resistance to Fracture Assessed in Incisors, Premolars and Molars
Keywords: Endodontic cavity
fracture resistance
dentin volume removed
instrumentation efficacy

Conservative endodontic cavity (CEC) may improve fracture resistance of teeth but compromise instrumentation of canals. Extracted human intact maxillary incisors, mandibular premolars and molars were imaged with micro-CT and assigned to CEC or traditional endodontic cavity (TEC) groups (n=10/group/type). Canals were prepared and post-treatment micro-CT images obtained. These teeth along with the negative controls were then loaded to fracture. Mean proportion of untouched canal-wall was significantly higher only in distal canals of molars with CEC compared to TEC. Mean dentin volume removed was significantly smaller for CEC in all tooth types. Mean load-at-fracture for CEC was significantly higher in premolars and molars without differing significantly from the negative controls. While CEC was associated with compromised canal instrumentation only in the distal canals of molars, it conserved coronal dentin in all three tooth types and increased resistance to fracture in the mandibular molars and premolars.
The Effects of Dilute Polymer Solutions on the Shape, Size, and Roughness of Abrasive Slurry Jet Micro-machined Channels and Holes in Brittle and Ductile Materials
Keywords: abrasive slurry jet
micro-machining
polymeric additives
fluid elasticity
erosion
viscosity

The present study investigated the effect of dilute polymer solutions on the size, shape, and roughness of channels and holes, machined in metal and glass using a novel abrasive slurry-jet micro-machining (ASJM) apparatus. The apparatus consisted of a slurry pump and a pulsation damper connected to an open reservoir tank to generate a 140-micron turbulent jet containing 1 wt% 10-micron alumina particles. With the addition of 50 wppm of 8-M (million) molecular weight polyethylene oxide (PEO), the widths of the channels and diameters of holes machined in glass decreased by an average amount of 25%. These changes were accompanied by approximately a 20% decrease in depth and more V-shaped profiles compared with the U-shape of the reference channels and holes machined without additives. The present results demonstrate that a small amount of a high-molecular-weight polymer can significantly decrease the size of machined channels and holes for a given jet diameter.
The Effects of Oxygen Glucose Deprivation and TRPM7 Activity on Slingshot Phosphatase and P-21 Activated Kinase Activity
Keywords: TRPM7
anoxia
oxygen glucose deprivation
slingshot phosphatase

Transient Receptor Potential Melastatin 7 (TRPM7) is a ubiquitously expressed divalent cation channel implicated as a key regulator of neuronal cell death in stroke. Our research group has previously shown that TRPM7 dependent cytoskeletal regulation particularly via cofilin mediates neuronal death in oxygen glucose deprivation (in vitro stroke model). LIMK1 phosphorylation was also shown to decrease downstream of TRPM7 activation during anoxia. In the present study we investigated the effects of TRPM7 activation during anoxia, on three regulators of LIMK and cofilin; Rho-associated kinase 2 (ROCK2), P-21 activated kinase 3 (PAK3) and Slingshot family phosphatase 1 (SSH1). Our findings suggest that PAK3 activity is downregulated during OGD through TRPM7 independent mechanisms. However, SSH1 activity appears to be regulated downstream of TRPM7 in a manner that is consistent with LIMK and cofilin regulation. Overall, our work suggests that SSH1 is a new link between anoxia-induced TRPM7activity and cofilin hyperactivation.
A Novel Iterative Method for Non-invasive Measurement of Cardiac Output
Keywords: Cardiac output
Fick principle
Liver transplant

This thesis provides a first description and proof-of-concept of iterative cardiac output measurement (ICO) – a respiratory, carbon-dioxide (CO2) based method of measuring cardiac output (CO). The ICO method continuously tests and refines an estimate of the CO by attempting to maintain the end-tidal CO2 constant. To validate the new method, ICO and bolus thermodilution CO (TDCO) were simultaneously measured in a porcine model of liver transplant. Linear regression analysis revealed the equation ICO = 0.69•TDCO + 0.65 with a Pearson correlation coefficient of 0.89. Analysis by the method of Bland and Altman showed a bias of -0.2 L/min with 95% limits of agreement from -1.1 to 0.7 L/min. The trending ability of ICO was determined using the half-circle polar plot method where the mean radial bias, the standard deviation of the polar angle, and 95% confidence interval of the polar angle were -8º, ±17º, and ±33º, respectively.
Multimodal Quantification of Interpersonal Physiological Synchrony between Non-verbal Individuals with Severe Disabilities and their Caregivers during Music Therapy
Keywords: synchrony
disability

Physiological interpersonal synchrony, the spontaneous alignment of indicators of physiological activity, is highly associated with the level of empathy between people in emotionally meaningful relationships. However, synchrony has not been studied with nonverbal, severely-disabled individuals, many of whom have a limited means to communicate. In this study, dyadic physiological synchrony in client-parent-therapist triads was quantified through simultaneously recording electrodermal activity, heart rate, cortical brain activity (client-parent only), and cortisol level. For the majority of the trials, a greater level of synchrony was observed in the client-parent dyads compared to the client-therapist dyads; however, the client-therapist dyads demonstrated an increased level of synchrony in the later trials. Electroencephalography analysis revealed widespread interbrain synchrony involving empathy-related regions. Our results suggest that even in the presence of disabilities, synchrony due to empathy exists and that the measurement of this synchrony may serve as a clinical adjunct to the self-report of interpersonal relationships.
Sources of Error in Image-based Computational Fluid Dynamics Modeling of Common Carotid Arteries
Keywords: hemodynamics
Computational Fluid Dynamics
CEMRA
carotid artery

Magnetic resonance imaging is often used as a source for reconstructing vascular anatomy for the purpose of computational fluid dynamics (CFD) analysis. We recently observed large discrepancies in such &ldquo;image-based&rdquo; CFD models of the normal common carotid artery (CCA) derived from contrast enhanced MR angiography (CEMRA). A novel quantitative comparison of velocity profile shape of N=20 cases revealed an average 25% overestimation of velocities by CFD, attributed to a corresponding underestimation of lumen area in the CEMRA-derived geometries. We hypothesized that this was due to blurring of edges in the images caused by dilution of contrast agent during the relatively long elliptic centric CEMRA acquisitions, and confirmed this with MRI simulations. CFD simulations incorporating realistic inlet velocity profiles and non-Newtonian rheology had a negligible effect on velocity profile skewing, suggesting a role for other sources of error or modeling assumptions.
Development of MEMS Repulsive Actuator for Large Out-of-plane Force
Keywords: MEMS Actuator, Out-of-Planes, stroke, repulsive force

This thesis describes the development of a MEMS repulsive actuator capable of producing a large out-of-plane force. Existing MEMS repulsive actuators are low out-of-plane force actuators that are unable to support or lift a mass of 1 mg. A high force MEMS repulsive actuator was developed to overcome this limitation. The design was optimized employing parameters of the actuator’s fingers to increase the out-of-plane force. A design was developed based on the analytical results derived from extending the mathematical model of an existing actuator. A commercial manufacturing process, PolyMUMPs, was used to fabricate a prototype which was tested to validate the analytical and computational results. The prototype achieved an out-of-plane displacement of 15 µm and a 0.2° angular rotation. The resonance frequency was 120 Hz, and the rise and fall times were measured as 14.5 ms and 3625 ms (3.6 sec), respectively. The estimated out-of-plane force is 40 µN.
Development and Validation of a Partially Coupled Two-equation Soot Model for Industrial Applications
Keywords: Particulate Formation
Two Equation
Soot Model
Ethylene Air

There are several reasons for reducing particulate formation as a result of combustion processes and to date, a number of approaches have been proposed to numerically predict soot. There is a trade-off between accuracy and computational cost and processing time. Two equation semi-empirical models have been used, with some success, to reconcile the need for fast solution turn around and accuracy. However, these models do not account for the mass balance between the gas phase and soot. In this study, the effects of mass conservation of the soot precursors in the gas phase were investigated in an ethylene-air laminar flame simulation at atmospheric pressure. Soot formation was predicted with a two-equation model. Then the model was modified for predicting soot in a turbulent ethylene-air flame operating at 1 atm. The new model is a [2+1]-equation model which accounts for the mass conservation of soot precursors.
The Effectiveness of Systematic Search Strategy Training for the Analysis of Panoramic Images
Keywords: Oral and Maxillofacial Radiology
Dental Education
Systematic analysis
Panoramic images
Training

Objectives: To examine the effectiveness of systematic search strategy training for the analysis of panoramic images. Methods: 41 students and 33 experienced dentists were recruited from King Abdulaziz University, Saudi Arabia. At baseline, participants analyzed 15 panoramic images, diagnosed whether the images were normal or abnormal, and marked the locations of the abnormalities. One week later, participants in the trained group were shown a training module illustrating a systematic strategy to analyze panoramic images. At post-test, they analyzed 15 new images matched for difficulty with pre-test images. Results: Mixed design ANOVAs revealed that for abnormality detection in the complex part of the panoramic image, trained students improved from baseline but dentists did not. The number of findings over-reported by students and dentists increased after training. Discussion: This study suggests some benefits in the systematic search strategy training for novices. Inclusion of training in normal panoramic features may reduce over-reported findings.
Translating Early Outgrowth Cell Therapy into a Clinically Relevant Approach for Long Term Renoprotection
Keywords: chronic kidney disease
early outgrowth cells
modular tissue engineering
conditioned medium

Current therapy for chronic kidney disease (CKD) is limited; however, recent studies have shown that a subpopulation of cells derived from the bone marrow, known as early outgrowth cells (EOCs), are able to attenuate kidney injury. Here we examined the efficacy of a modular tissue engineering system whereby the EOCs might be easily removed in the event of malignant change. While modular therapy mimicked the effects seen with standard EOC therapy, the modules degraded allowing the encapsulated EOCs to enter systemic circulation. Given the presumed egress of EOCs, we explored an alternative strategy for kidney protection. Here we investigated the long-term effectiveness of administering the conditioned medium (EOC-CM) that contains the factors the EOCs secrete, rather than the cells themselves. In these studies, repeated administration of EOC-CM attenuated the structural and functional manifestations of kidney injury suggesting that this approach may provide an effective and feasible, cell-free approach for CKD.
The Participation of the Third Parties in the Arbitration Proceedings
Keywords: problem of possible participation of the third parties
arbitration proceedings
arbitration legislation
Kazakhstan

The arbitration legislation of Kazakhstan has no direct answer to the problem of possible participation of the third parties therein. The analysis of the Kazakhstani legislation and practice, as well as the comparison of the Kazakhstani approach with international approaches regarding the problem of the third parties have revealed the necessity in the legislative reforms to be taken in Kazakhstan. These reforms are required for stabilization and equilibration of the position of third parties with all rest parties of the arbitration proceedings. Thus, the main aim of this thesis is to elaborate a series of suggestions on the potential development of the arbitration procedural legislative system and to address some of the gaps in the existing arbitration legislation.
SD Storage Array: Development and Characterization of a Many-device Storage Architecture
Keywords: flash memory
secure digital
FPGA
prototype
transactional workload
OLTP

Transactional workloads have storage request streams consisting of many small, independent, random requests. Flash memory is well suited to these types of access patterns, but is not always cost-effective. This thesis presents a novel storage architecture called the SD Storage Array (SDSA), which adopts a many-device approach. It utilizes many flash storage devices in the form of an array of Secure Digital (SD) cards. This approach leverages the commodity status of SD cards to pursue a cost-effective means of providing the high throughput that transactional workloads require. Characterization of a prototype revealed that when the request stream was 512B randomly addressed reads, the SDSA provided 1.5 times the I/O operations per second (IOPS) of a top-of-the-line solid state drive, provided there were at least eight requests in-flight. A scale-out simulation showed the IOPS should scale with the size of the array, provided there are no upstream bottlenecks.
Evaluation of the Frequency and Time Domain Soil-structure Interaction Analysis Methods against the Hualien Large-scale Seismic Test (LSST) Data
Keywords: Structural Engineering
Geotechnical Engineering

Nonlinear seismic soil-structure interaction (SSI) analyses are often completed using the equivalent linear frequency domain analysis method as it is simple to use and computationally efficient. However, the method is inherently linear and a better strategy is to employ the nonlinear time domain analysis method, which is computer intensive but can more accurately simulate nonlinear soil behavior. In this thesis, the two methods are evaluated using the Hualien LSST field data. For the nonlinear time domain analyses, the utilized Hualien LSST finite element model is initially verified by comparing its linear responses to those obtained via the linear frequency domain analysis method; which is also verified against the multi-step analysis approach. In the frequency domain, the equivalent linear analyses are completed by an industry collaborator. The results show that two methods generate similar responses for the low intensity earthquakes but differ for the more intense and amplified earthquakes.
Serial Measures of the Cortisol Awakening Response during Treatment for Depression in an Inpatient Setting
Keywords: Depression
Cortisol
Treatment Outcome
HPA
Cortisol Awakening Response
Prediction

Goal: To determine whether the Cortisol Awakening Response (CAR) associates with treatment response and course in hospital for inpatients with major depressive disorder (MDD). Methods: The CAR was measured at admission and discharge in patients completing a four-week inpatient program for MDD. Self-report questionnaires were used to assess changes in depression, anxiety, and perceived stress. Results: Over the four week hospital stay measures of CAR reactivity (Delta, AUCi) decreased, but there was no significant correlation between the change in CAR reactivity and change in clinical symptoms. Cross-sectional measurements of the CAR reactivity at both admission and discharge were strongly correlated with the drop in depression scores in hospital. Furthermore, poor treatment responders had a significantly lower CAR reactivity at both admission and discharge than did good responders. Conclusion: Individuals with higher CAR reactivity at admission and discharge had the greatest reduction in depression over the course of treatment.
Association of Leg Length with Metabolic Abnormalities Underlying Type 2 Diabetes Mellitus
Keywords: Early childhood conditions
Insulin resistance
Beta-cell dysfunction
Anthropometry
Leg length
Metabolic Syndrome
Continuous Metabolic Syndrome score
Type 2 diabetes
Stature
Height
Developmental origins of health and disease

The objective of this thesis was to determine the association of leg length (LL), a marker of early childhood conditions, with metabolic abnormalities underlying type 2 diabetes. Utilizing data from a population at-risk for diabetes, the associations of LL with i) insulin resistance (IR) and beta-cell dysfunction and ii) a continuous metabolic syndrome risk score (MetScore) were analyzed. Results showed that shorter LL was associated with IR and beta-cell dysfunction, and that the combination of short legs and large waist (a marker of adult obesogenic conditions) was associated with the greatest IR. Height, a marker of overall childhood conditions, was found to be inversely associated with the MetScore. Therefore, both adverse childhood conditions and early-late life mismatched conditions may increase the risk for diabetes through differing pathways. Improving childhood conditions (i.e. nutritionally or economically) may be an important strategy to prevent diabetes.
Nonlinear Finite Element Analysis and Post-processing of Reinforced Concrete Structures under Transient Creep Strain
Keywords: JANUS
Post-processor
Transient creep
Fire
Concrete
Programming

A suite of NLFEA programs, VecTor, has been developed at the University of Toronto. However, this software still requires the development of other functions to execute some types of analyses. One of the required functions is the consideration of transient creep strain in the heat transfer analysis. Moreover, there is a strong need to develop a general graphics-based post-processor applicable to VecTor programs. The first objective of this thesis is to develop a function considering the effect of the transient creep strain, because it can have significant influence on the behaviour of concrete under elevated temperatures. The second purpose of this thesis is to construct the new analysis visualization features compatible with entire suite of VecTor programs. As the result, the modified post-processor, JANUS, has had its abilities expanded significantly.
Interaction between a Molten Smelt Droplet and Water at Different Temperatures
Keywords: chemical engineering
vapor explosion
kraft pulping

In a kraft recovery dissolving tank, high temperature molten smelt droplets fall into an aqueous solution and dissolve. The rapid heat transfer between molten smelt and water can lead to violent dissolving tank operation, and in severe cases, a dissolving tank explosion. In this study, an experimental apparatus was built to investigate the interaction between a molten synthetic smelt droplet and water. Smelt-water interaction was documented, and the effects of water and smelt temperatures on droplet explosion probability, explosion delay time, and explosion intensity were examined. The results show that explosions always occur below a lower critical water temperature, which is a function of smelt temperature, and never explodes above an upper critical water temperature. Up to the upper critical water temperature, as the water temperature increases, the explosion probability decreases, and the explosion delay time and the explosion intensity increases. A Smelt-Water Interaction Temperature (SWIT) diagram was constructed to describe the explosion probability at different smelt and water temperatures.
Optical, Structural, and Electrical Characterization of Colloidal Nanocrystalline Silicon
Keywords: Silicon Nanocrystal
Photoluminescence
Size-Selective
Conductivity
Charge Transport

In this thesis, colloidal nanocrystalline silicon (ncSi) capped with allylbenzene (AB) groups, is created using a sol-gel method. This novel material, AB-ncSi, is size separated and its optical, structural, and electrical characteristics are investigated in detail. For optical characterization, the photoluminescence (PL) peak is located for each fraction of the nanoparticles to determine its diameter. The AB-ncSi samples have diameters ranging from 2.89 nm to 7.65 nm. Ellipsometry and scanning electron microscopy (SEM) are used to estimate the film thickness and average distance between the particles, respectively, for structural characterization. No correlation was found between AB-ncSi size and film thickness however the estimated average distance between the particles decreased with decreasing diameter. Finally, for electrical characterization, conductivity of size-separated samples is measured and the temperature dependent conductance is analyzed. The results emerging from these analyses suggest that the charge transport mechanism for AB-ncSi is nearest-neighbor hopping (NNH) albeit VRH is also a potential contributor.
Machine Learning for Variant Detection and Population Analysis in Heterogenerous Cancer Sample
Keywords: Single nucleotide variant
Machine learning
Cancer heterogeneity

Cancer is a complex and deadly disease that is caused by genetic lesions in somatic cells. Further research in computational methodology for detecting and characterizing somatic mutations is necessary in order to understand the comprehensive systems level model of the roles of those lesions in cancer development. In the first project, I trained a list of supervised machine learning classifiers that classify false positive versus true positive somatic single nucleotide variants (SNVs). I was able to show an improvement of somatic SNV detection on the data set over the reported classifier. In the second project, we developed PhyloSub model that uses a nonparametric Bayesian prior over a set of trees to cluster SNVs, and infer the subclonal phylogenetic structure of tumors with uncertainty from SNV sequencing data. Experiments showed that PhyloSub model could infer the subclonal phylogenetic structure from both single and multiple tumor samples.
Analytical Modelling of Carrier Depletion Silicon-on-insulator Optical Modulation Diodes
Keywords: Optoelectronics
Modulators
PN junctions
Photonics

We derive an analytical model for the depletion capacitance of silicon-on-insulator (SOI) optical modulation diodes. This model accurately describes the parasitic fringe capacitances due to a lateral pn junction and can be extended to other geometries, such as vertical and interleaved junctions. Analytical results show excellent agreement with numerical simulations. The model is used to identify the waveguide slab to rib height ratio as a key geometric scaling parameter for the modulation e ciency and bandwidth for lateral diodes. We characterise the fringe capacitance as a parasitic e ffect that leads to a decrease of about 20% in modulation bandwidth of typical SOI diodes without a corresponding increase in modulation effi ciency. From the scaling relations, the most e ffective way to increase the modulation bandwidth is to reduce the series resistance of the diode. In the light of our analysis, we propose high-speed and low power microdisk structures for future SOI modulators.