Engineering Commons^™

Towards Clinical Microscopic Fractional Anisotropy Imaging, Nico Jj Arezza

Electronic Thesis and Dissertation Repository

Microscopic fractional anisotropy (µFA) is a diffusion-weighted magnetic resonance imaging (dMRI) metric that is sensitive to neuron microstructural features without being confounded by the orientation dispersion of axons and dendrites. µFA may potentially act as a surrogate biomarker for neurodegeneration, demyelination, and other pathological changes to neuron microstructure with greater specificity than other dMRI techniques that are sensitive to orientation dispersion, such as diffusion tensor imaging. As with many advanced imaging techniques, µFA is primarily used in research studies and has not seen use in clinical settings.

The primary goal of this Thesis was to assess the clinical viability of …

Development Of A Wearable Haptic Feedback Device For Upper Limb Prosthetics Through Sensory Substitution, Marco B.S. Gallone

Electronic Thesis and Dissertation Repository

Haptics can enable a direct communication pipeline between the artificial limb and the brain; adding haptic sensory feedback for prosthesis wearers is believed to improve operation without drawing too much of the user's attention. Through neuroplasticity, the brain can become more cognizant of the information delivered through the skin and may eventually interpret it as inherently as other natural senses. In this thesis, a wearable haptic feedback device (WHFD) is developed to communicate prosthesis sensory information. A 14-week, 6-stage, between subjects study was created to investigate the learning trajectory as participants were stimulated with haptic patterns conveying joint proprioception. 37 …

Cardiac Modelling Techniques To Predict Future Heart Function And New Biomarkers In Acute Myocardial Infarction, Sergio C. H. Dempsey

Electronic Thesis and Dissertation Repository

Fundamental to treatment planning for patients that have suffered myocardial infarction are predictive biomarkers and risk factors. Important among these in terms of a patient’s treatment plan or prognosis are the contractility of the damaged myofibers, final infarct volume, and poor infarct healing rate. Proposed and developed in this thesis are techniques to predict these biomarkers and risk factors using cardiac biomechanical modelling. One of the developed techniques was a CT compatible shape optimization technique which can predict the contraction force of healthy, and stunned myofibers within 6.3% and the distribution of potentially necrotic myofibers within 10% accuracy. The second …

Extracellular Matrix-Derived Modular Bioscaffolds For Soft Connective Tissue Regeneration, Pascal Morissette Martin

Electronic Thesis and Dissertation Repository

Human decellularized adipose tissue (DAT) represents a promising extracellular matrix (ECM) source for the development of biomaterials, with its properties conductive of angiogenesis, adipogenesis, and scaffold remodelling. This thesis sought to provide new fundamental insight into the design of ECM-derived bioscaffolds by developing novel modular biomaterials for soft connective tissue regeneration and by studying the effects of ECM composition on cell function and fate.

Initial studies explored the effects of ECM composition of pre-assembled bead foams derived from DAT or commercially-sourced bovine collagen (COL) on human wound edge dermal fibroblasts (weDFs) sourced from chronic wounds. In vitro testing under conditions …

Using An Internal Auditory Stimulus To Activate The Developing Primary Auditory Cortex: A Fetal Fmri Study, Estee Goldberg

Electronic Thesis and Dissertation Repository

Insight into the rapidly developing brain in utero is scarce. Fetal functional magnetic resonance imaging (fMRI) is a technique used to gain awareness into the developmental process. Previous auditory task-based fMRI studies employed an external sound stimulus directly on the maternal abdomen. However, there has since been recommendation to cease doing so. We sought to investigate a reliable paradigm to study the development of fetal brain networks and postulate that by using an internal stimulus, such as the mother singing, it would result in activation of the fetal primary auditory cortex. Volunteers carrying singleton fetuses with a gestational age of …

Bioremediation Of Refinery Desalter Effluent Using Debaryomyces Hansenii And Parachlorella Kessleri, Leila Azimian

Electronic Thesis and Dissertation Repository

Crude oil desalting operations produce an effluent stream which is challenging to treat due to its salt, heavy metal and hydrocarbon content. Consequently, desalter effluent (DE) is usually diluted into other effluent streams and sent to conventional wastewater treatment plants which may lead to upsets the plant operation.

In this study, a novel microbial approach was applied which investigated DE treatment using halotolerant yeast Debaryomyces hansenii (LAF-3 10 U) or the environmentally robust micro-algae Parachlorella kessleri strain CPCC 266. The effect of these two different approaches on both synthetic and actual DE was investigated in both batch and/or continuous mode. …

Formation Of A Vascular Regenerative Microenvironment Within Implantable Human Decellularized Adipose Tissue Bioscaffolds, Christopher Leclerc

Electronic Thesis and Dissertation Repository

Cellular therapies targeted at stimulating therapeutic angiogenesis in individuals with critical limb ischemia (CLI) have been under intense investigation. Hematopoietic progenitor cells (HPC) derived from umbilical cord blood have been previously shown to support limb revascularization in animal models of CLI, despite limited cell survival at the site of ischemia. This study attempted to improve HPC survival after transplantation and prolong pro-angiogenic function using human decellularized adipose tissue (hDAT) as a novel cell delivery platform. Compared to HPC conventionally grown on tissue-cultured plastic, hDAT scaffolds were shown to promote viability and proliferation of seeded HPC, and had cell- instructive effects …

A Ph-Sensitive Delivery System For The Prevention Of Dental Caries Using Salivary Proteins, Yi Zhu

Electronic Thesis and Dissertation Repository

Dental caries remains one of the most common chronic diseases worldwide. Salivary proteins such as histatins have demonstrated biological functions directly related to tooth homeostasis and prevention of dental caries. However, histatins are susceptible to the high proteolytic activities in the oral environment. Therefore, pH-sensitive chitosan nanoparticles (CNs) have been proposed as potential carriers to target major oral diseases that occur under acidic conditions (e.g. dental caries and dental erosion). Four different types of chitosan polymers were investigated and the optimized CNs successfully loaded histatin 3 and released it selectively under acidic conditions. Through loading the survival time of histatin …

Plant Stimuli-Responsive Biodegradable Polymers For The Use In Timed Release Fertilizer Coatings, Spencer Heuchan

Electronic Thesis and Dissertation Repository

The use of nitrogen-based fertilizers continues to accelerate with human population growth and increases in global food requirements. Enhanced efficiency fertilizers (EEFs) have been developed to improve the synchronization between nutrient supply and crop nutrient demand. However, many of the current controlled release fertilizers are coated with non-degradable polymers that contribute to accumulation of microplastics within ecosystems. This thesis describes research towards the development of a new class of fertilizer coatings using a self-immolative polymer known as poly (ethyl glyoxylate) (PEtG). PEtG itself does not have suitable properties to produce a viable coating but once blended with another degradable polyester …

Evaluating Devices For The Measurement Of Auditory-Evoked Fetal Movement, Patrick Gatutsi

Electronic Thesis and Dissertation Repository

Determining normal and abnormal fetal function in utero in order to better predict which fetuses are at risk for adverse outcome is critical. However, the medical imaging tools that could assist with diagnosis are very expensive and rarely available in the developing world. In this study, we developed a prototype audio-motio-tachograph (AMTG), which measures fetal movements through the recording of abdominal wall deformations and tested it in Rwanda. First, we showed that AMTG detected fetal signals and that fetuses respond to complex acoustic stimuli. In order to improve the sensitivity of the device, we then measured whole abdominal wall deformations …

Autohydrolysis Pretreatment Of Mixed Lignocellulosic Biomass, Claudio Lira

Electronic Thesis and Dissertation Repository

Lignocellulosic biomass, such as agricultural and forestry residues, can be transformed into valuable fuels and chemicals. However, the high cost of feedstock handling and the complex nature of cellulosic biomass processing and conversion remain two major challenges in biorefineries. This thesis aims to tackle these challenges by assessing the transformation of multi-feedstock using autohydrolysis pretreatment.

Corn cobs and stover (residues from corn processing), poplar chips (forestry residue), bagasse and wheat straw (agricultural residues) are abundant and often under-utilized cellulosic residues. These feedstocks were used to investigate the effects of biomass characteristics on the composition of the autohydrolysis pretreatment products. Moreover, …

Efficient Alignment Algorithms For Dna Sequencing Data, Nilesh Vinod Khiste

Electronic Thesis and Dissertation Repository

The DNA Next Generation Sequencing (NGS) technologies produce data at a low cost, enabling their application to many ambitious fields such as cancer research, disease control, personalized medicine etc. However, even after a decade of research, the modern aligners and assemblers are far from providing efficient and error free genome alignments and assemblies respectively. This is due to the inherent nature of the genome alignment and assembly problem, which involves many complexities. Many algorithms to address this problem have been proposed over the years, but there still is a huge scope for improvement in this research space.

Many new genome …

Genetic Engineering Studies Of Escherichia Coli And Microalgae For Expression Of Hydrolytic Enzymes And Development Of High Throughput Screening Technique, Shreyas S. Yedahalli

Electronic Thesis and Dissertation Repository

The field of biochemical engineering has made substantial progress through major advances in genetic and metabolic engineering with applications in various sectors such as energy, food science, pharmaceuticals, etc. The hosts used for this work are constantly broadening. A host particularly important for energy applications are microalgae. The potential to enhance microalgae genetically for energy applications is not well explored and was therefore investigated in this thesis. Non-photosynthetic micro-organisms and photosynthetic microalgae offer a potential approach to enhance sustainable biochemical production. In this study expression vectors for Escherichia coli (E. coli) and Chlorella vulgaris (C. vulgaris) …

Basic Science To Clinical Research: Segmentation Of Ultrasound And Modelling In Clinical Informatics, Ali K. Hamou

Electronic Thesis and Dissertation Repository

The world of basic science is a world of minutia; it boils down to improving even a fraction of a percent over the baseline standard. It is a domain of peer reviewed fractions of seconds and the world of squeezing every last ounce of efficiency from a processor, a storage medium, or an algorithm. The field of health data is based on extracting knowledge from segments of data that may improve some clinical process or practice guideline to improve the time and quality of care. Clinical informatics and knowledge translation provide this information in order to reveal insights to …

Investigation Of Chitosan-Based Hydrogels As A Cell Delivery Platform For Adipose-Derived Stem/Stromal Cell Transplantation To Promote Angiogenesis In Ischemic Tissues, Jobanpreet Singh Dhillon

Electronic Thesis and Dissertation Repository

Stem cell transplantation is under investigation to stimulate angiogenesis in patients with peripheral artery disease. To develop a cell-delivery platform that enhances cell retention and function post-transplantation, the response of human adipose-derived stem/stromal cells (ASCs) encapsulated within N-methacrylate glycol chitosan (MGC) hydrogels with or without integrin-binding RGD or IKVAV motifs was explored. ASC viability was enhanced in the MGC and MGC-RGD hydrogels relative to the MGC-IKVAV group under hypoxic (2% O­₂) culture conditions, with cell spreading and higher metabolic activity noted in MGC-RGD at 14 days. Analysis of angiogenic gene expression revealed similar patterns between all hydrogel …

Microbial Repopulation Following In Situ Star Remediation, Gavin Overbeeke

Electronic Thesis and Dissertation Repository

In situ STAR (Self-sustaining Treatment for Active Remediation) is an emerging remediation technology which uses smouldering combustion to destroy nonaqueous phase liquid (NAPL) contamination in the subsurface. Since STAR smouldering travels through contaminated soils slowly (~0.5 to 5 m/day) and subjects them to high temperatures (400–1000°C), it is expected that this technology will thoroughly dry and sterilize the zones which it treats. Further, soils surrounding the treatment zone which are not smouldered will be heated, although not smouldered, by virtue of their proximity to STAR, impacting microbial communities within them. Therefore, the objectives of this work are to quantify the …

Evapotranspiration From Extensive Green Roofs: Influence Of Climatological Conditions, Vegetation Type, And Substrate Depth, Maria Eloisa Sia

Electronic Thesis and Dissertation Repository

Green roofs are gaining popularity worldwide as a low impact development tool to mitigate increasing stormwater runoff within dense urban areas. Evapotranspiration (ET) is the key hydrologic process governing the capacity of a green roof to retain rainfall as it regenerates available water storage space in the green roof substrate (soil) between rainfall events. To date, there are limited data on how the interaction between different climatological conditions and design parameters (e.g., vegetation type, substrate depth) affect ET rates. This currently limits the ability to optimize green roof design for stormwater management. In this field study, the impact of climatological …

Abe Fermentation From Low Cost Substrates, Kai Gao

Electronic Thesis and Dissertation Repository

The high cost of substrate and product inhibition in the fermentation broth remains two major problems associated with bio-butanol production. This thesis aims to solve these problems by examining abundant lignocellulosic biomass as potential feedstocks and exploring novel substrates such as carbohydrates derived from microalgae for ABE fermentation. The commonly observed toxic effect after pretreatment of lignocelluslosic biomass was removed by resin adsorption, where the resin could also serve as an in-situ butanol recvoery devices.

Corn cobs (an agricultural waste), switchgrass (an energy crop) and phragmites (an invasive plant in North America) were investigated as substrates for ABE fermentation by …

Fermentative Processes Requiring Low Solubility Feed Gases: An Investigation Into Gas-Dependent Microorganisms, Eric W. Doerr

Electronic Thesis and Dissertation Repository

Two bioprocesses were separately investigated based on their common interest of using gaseous substrates that have low solubility. The first process involved the development of a mixed culture using two organisms capable of utilizing glycerol and carbon monoxide separately to increase biobutanol production, while the second process involved an investigation of different production media used in aerobic xanthan production of Xanthomonas campestris with pressurization effects. It was determined that Clostridium pasteurianum should be used with an organism like Clostridium carboxidivorans or Eubacterium limosum in order for butyrate uptake at 3 g/L to occur with a minimum 0.1 g/L butyrate production. …

A Systems Approach To Modelling The Effects Of Climate Change On Agroforestry: A Case Study In Western Tanzania, Elaine M. Samuel

Electronic Thesis and Dissertation Repository

Climate change is anticipated to have significant effects on agricultural production in sub-Saharan Africa as the magnitude of weather events increase in severity. Smallholder farmers in western Tanzania are potentially vulnerable to climate change impact as crops rely on precipitation as the only source of water. It is prudent to evaluate different modes of agricultural adaptations, such as agroforestry, that these farmers can easily adopt to improve their resiliency to the effects of climate change. System dynamics modelling is a cost-effective tool to simulate the long-term behaviour of agroforestry systems under future climate conditions. Water, Nutrient, and Light Capture in …

Minor Whey Protein Purification Using Ion-Exchange Column Chromatography, Naeimeh Faraji Dizaji

Electronic Thesis and Dissertation Repository

This thesis is concerned with application of mechanistic models for recovery and purification of two minor milk proteins to develop an efficient and robust process. A fundamental and quantitative understanding of the underlying mechanisms assists to evaluate chances and challenges in non-linear chromatography.

The first chapter considers adsorption isotherm data of two minor whey proteins on cation exchanger under various conditions and used as the basis to develop a predictive approach for correlating adsorption behavior using a mechanistic isotherm model. The SMA isotherm model explicitly considers the contributions of protein-adsorbent and protein-protein interactions in the simulation of salt gradients in …

Markerless Radiostereogammetry Of The Shoulder Joint In Humans: Comparisons Of Scapulohumeral Kinematics Between Individuals With Healthy And Supraspinatus-Impaired Shoulders, Ashley N. Hannon

Electronic Thesis and Dissertation Repository

The purpose of this collection of studies was to further develop the knowledge of shoulder motion in order to better understand joint function through direct measurement of 3D scapulohumeral joint kinematics using a technique of high accuracy. Markerless, bi-planar fluoroscopic radiostereometric analysis using a generic shoulder model was developed in this thesis, reducing the amount of radiation exposure to subjects. The studies compared kinematic data of the scapulohumeral joint in six degrees of freedom with a precise, in-vivo measuring technique. Data were collected on young and older healthy individuals, individuals with a torn supraspinatus and post-surgical intervention.

Although this generic …

The Role Of Bone Sialoprotein In Periodontal Tissue Development And Bone Repair, Yohannes Soenjaya

Electronic Thesis and Dissertation Repository

Bone development and repair involve complex processes that include interaction between cells and their surrounding matrix. In the body, bone sialoprotein (BSP) expression is up-regulated at the onset of mineralization. BSP is a multifunctional acidic phosphoprotein with collagen-binding, hydroxyapatite nucleating, and integrin recognition (RGD sequence, which is important for cell-attachment and signaling) regions. Mice lacking BSP expression (Bsp^-/-), exhibit a bone phenotype with reductions in bone mineral density, bone length, osteoclast activation, and impaired bone healing. This thesis examined the role of BSP in tooth development and also its potential use as a therapeutic reagent for bone …

Application Of 3d Printing Technology In Porous Anode Fabrication For Enhanced Power Output Of Microbial Fuel Cells, Bin Bian

Electronic Thesis and Dissertation Repository

Microbial fuel cells (MFCs) are widely researched for application in wastewater treatment. However, the current anodes used in MFCs often suffer from high fabrication cost and uncontrollable pore sizes. In this thesis, three-dimensional printing technique was utilized to fabricate anodes with different micro pore sizes for MFCs. Copper coating and carbonization were applied to the printed polymer anodes to increase the conductivity and specific surface area. Voltages of MFCs with various anodes were measured as well as other electrochemical tests such as linear sweep voltammetry and electrochemical impedance spectroscopy. 3D copper porous anode produced higher maximum voltages and power densities …

The Application Of The Ultrafine Technology In Improving The Biocompatibility And Osteo-Inductivity Of Dental Implants, Nicholas Y. Hou

Electronic Thesis and Dissertation Repository

Dental implants are very effective medical devices. However, although stable, the conventional titanium implants are not very bioactive which in some instances could reduce their efficacy. This thesis described the research progress of using polymeric ultrafine-particles with bioactive additives to enrich the surface of titanium substrate, thereby increasing the biocompatibility and osteo-inductivity of the biomaterial. During this doctoral project, three different types of polymers were examined, initially the conventional polyester, and later the novel epoxy as well as the epoxy/polyester hybrid polymers. Physical characterizations confirmed that all of the coating powders were ultrafine particles, and homogeneous surfaces were constructed from …

Field Scale Application Of Nanoscale Zero Valent Iron: Mobility, Contaminant Degradation, And Impact On Microbial Communities, Chris M.D. Kocur

Electronic Thesis and Dissertation Repository

This thesis began by verifying that nanoscale zero valent iron (nZVI) synthesis methods could be scaled up and implemented at the field scale in a safe manner. This led to successful demonstration of nZVI injection and mobility under constant head gravity injection into a contaminated utility corridor in Sarnia, Ontario. Where field studies have fallen short in the past was linking the somewhat qualitative field geochemical parameters to other evidence of nZVI transport. Definitive nZVI detection was elusive in previous field studies due to the highly reactive nature of the particles caused by their high surface area. nZVI was detected …

Resting-State Functional Network Disruptions In A Rodent Model Of Mesial Temporal Lobe Epilepsy (Tle), Ravnoor Singh Gill

Electronic Thesis and Dissertation Repository

Mesial temporal lobe epilepsy (TLE) is the most common form of drug-refractory epilepsy. The clinical application of non-invasively mapped networks using resting-state functional magnetic resonance imaging (rsfMRI) in humans has been rather limited due to heterogeneous (varying etiology, drugs, onset, latent period, etc.) patient groups. We employed a pharmacological (kainic acid) rodent model of TLE to measure the extent of functional network disruptions using rsfMRI, and study selected behaviors and olfactory to hippocampus transmission. Graph theoretical network modelling and analysis revealed significant increase in functional connectivity connectivity to the temporal lobe (hippocampus) in epileptic-rats compared to controls in the limbic …

Production And Applications Of Formaldehyde-Free Phenolic Resins Using 5-Hydroxymethylfurfural Derived From Glucose In-Situ, Yongsheng Zhang

Electronic Thesis and Dissertation Repository

The phenol-formaldehyde (PF) resin manufacturing industry is facing a growing challenge with respect to concerns over human health, due to the use of carcinogenic formaldehyde and sustainability due to the use of petroleum-based phenol in PF resin manufacture. Glucose and its derivative, 5-hydroxymethylfurfural (5-HMF), have proven to be potential substitutes for formaldehyde in the synthesis of phenolic novolac resins.

This thesis investigated a number of glucose and 5-HMF resin systems including the curing of phenol-glucose novolac resin (PG) with a bis-phenol-A type epoxy. The curing process was modeled according to the Sestak-Berggren equation (S, B) using Málek methods. This was …

Advances In Image Acquisition And Filtering For Mri Neuroimaging At 7 Tesla, Andrew T. Curtis

Electronic Thesis and Dissertation Repository

Performing magnetic resonance imaging at high magnetic field strength promises many improvements over low fields that are of direct benefit in functional neuroimaging. This includes the possibility of improved signal-to-noise levels, and increased BOLD functional contrast and spatial specificity. However, human MRI at 7T and above suffers from unique engineering challenges that limit the achievable gains. In this thesis, three technological developments are introduced, all of which address separate issues associated with functional magnetic resonance neuroimaging at very high magnetic field strengths.

First, the image homogeneity problem is addressed by investigating methods of RF shimming — modifying the excitation portion …

The Effects Of Oar-Shaft Stiffness And Length On Rowing Biomechanics, Brock Laschowski

Electronic Thesis and Dissertation Repository

This work investigates the effects of oar-shaft stiffness and length on rowing biomechanics. The mechanical properties of the oar-shafts were examined using an end-loaded cantilever system, and theoretical relations were proposed between the mechanics of the oar-shafts and rowing performance. On-water experiments were subsequently conducted and rowing biomechanics measured via the PowerLine Rowing Instrumentation System. The PowerLine system measures force and oar angle on the oarlock, as well as proper boat acceleration. The convergent validity and test-retest reliability of the PowerLine force measurements were determined prior to the on-water experiments. Thereafter, rowers were tested over a set distance using oar-shafts …