Life Sciences Commons^™

Identification And Characterization Of The Isoflavonoid-Specific Prenyltransferase Gene Family To Prevent Stem And Root Rot In Soybean, Arjun Sukumaran

Electronic Thesis and Dissertation Repository

Soybean is one of the most predominantly grown legumes worldwide, however, one deterrent to maximizing its yield is the pathogen, Phytophthora sojae, which causes stem and root rot disease. Many strategies have been implemented to combat this pathogen such as use of pesticides and certain agricultural practices. However, these have been largely ineffective in completely preventing P. sojae infection. An alternative strategy would be to improve the innate resistance of soybean by promoting increased glyceollin production. Glyceollins are soybean-specific antimicrobial agents which are derived from the isoflavonoid branch of the general phenylpropanoid pathway. Soybeans produce 3 forms of glyceollin: …

Development And Performance Evaluation Of An Antibody-Based Technology For Detection Of E. Coli O157 In Meat Samples And Its Potential Evolution Using Antibody Engineering, Yadira Tejeda Saldaña

Electronic Thesis and Dissertation Repository

Escherichia coli O157 is a persistent pathogen linked to food and waterborne infectious outbreaks with severe health consequences such as hemorrhagic colitis and hemolyticuremic syndrome (HUS). Because it is considered one of the major pathogens that contributes to the global burden of foodborne disease, its early detection within the food chain is an important milestone towards reducing foodborne diseases and economic losses due to contaminated food. Herein, the development and validation of a lateral flow immunoassay (LFIA) point-of-care (POC) device is described. Application of the LFIA test kit was focused on detection of E. coli O157 in raw meat products …

Hemolytic Activity In The Euryhaline Fish-Killing Phytoflagellate Prymnesium Parvum Under Environmental Stresses, Christine Dulal-Whiteway

Electronic Thesis and Dissertation Repository

Harmful algal blooms (HABs) are vast expanses of noxious or toxic phytoplankton that periodically dominate coastal ocean waters or freshwater systems. An especially damaging type of HAB are the species that kill fish. In this thesis, a potentially invasive marine fish-killing flagellate, Prymnesium parvum, was investigated for its tolerance to freshwater conditions. This species has invaded some freshwater systems in the southern United States. The thesis examines if the growth rate and toxicity of Prymnesium parvum remain high under low salinities similar to freshwater systems. A hemolytic lysis assay was used as a proxy for toxicity. The findings presented …

Identification Of A Novel Interaction Between Integrin-Linked Kinase And Beta-Arrestin 1, Hannah E. Murphy-Marshman

Electronic Thesis and Dissertation Repository

Integrin-linked kinase (ILK) is a ubiquitous scaffold protein essential for the development of front-rear polarity and directional migration of epidermal keratinocytes. β-arrestin 1 is another adaptor protein which has recently emerged as a key factor in modulating proliferation and migration of various cell types. Previous studies have demonstrated an association between β-arrestin 2 and ILK in cerebellar granule precursor cells. I have now identified a novel interaction between ILK and β-arrestin 1 in primary keratinocytes that occurs directly and without post-translational modifications. The N-terminal 67 residues of ILK and multiple regions in β-arrestin 1 are important for this interaction. This …

The Neural Mechanisms Of Musical Rhythm Processing: Cross-Cultural Differences And The Stages Of Beat Perception, Daniel J. Cameron

Electronic Thesis and Dissertation Repository

Music is a universal human behaviour, is fundamentally temporal, and has unique temporal properties. This thesis presents research on the cognitive neuroscience of the temporal aspects of music: rhythm, beat, and metre. Specifically, this work investigates how cultural experience influences behavioural and neural measures of rhythm processing, and the different neural mechanisms (with particular interest in the role of the striatum) that underlie different stages of beat perception, as musical rhythms unfold.

Chapter 1 presents an overview of the existing literature on the perceptual, cognitive, and neural processing of rhythm, including the entrainment of neural oscillations to rhythm and 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 …

Role Of Anterior Cingulate Cortex In Saccade Control, Sahand Babapoor-Farrokhran

Electronic Thesis and Dissertation Repository

Cognitive control is referred to the guidance of behavior based on internal goals rather than external stimuli. It has been postulated that prefrontal cortex is mainly involved in higher order cognitive functions. Specifically, anterior cingulate cortex (ACC), which is part of the prefrontal cortex, is suggested to be involved in performance monitoring and conflict monitoring that are considered to be cognitive control functions.

Saccades are the fast eye movements that align the fovea on the objects of interest in the environment. In this thesis, I have explored the role of ACC in control of saccadic eye movements. First, I performed …

A Test Of The Effects Of Androgens On Immunity: No Relationship Between 11-Keto Testosterone And Immune Performance In Bluegill Sunfish (Lepomis Macrochirus), John W. Loggie

Electronic Thesis and Dissertation Repository

The posited immunosuppressive effects of androgens are a key component of the immunocompetence handicap hypothesis (ICHH). My thesis uses bluegill sunfish (Lepomis macrochirus) to test two predictions arising from this hypothesis: (1) natural concentrations of the androgen 11-keto testosterone (11-KT) will be negatively related with immunity, and (2) an immunochallenge will lower 11-KT concentration. I found no evidence for a relationship between natural 11-KT concentration and measures of immunity (leukocyte counts, respiratory burst, cytokine gene expression), and an immunochallenge with Vibrio vaccine did not affect 11-KT concentration. I performed a meta-analysis of immunochallenge studies to help interpret my …

Algorithms For Glycan Structure Identification With Tandem Mass Spectrometry, Weiping Sun

Electronic Thesis and Dissertation Repository

Glycosylation is a frequently observed post-translational modification (PTM) of proteins. It has been estimated over half of eukaryotic proteins in nature are glycoproteins. Glycoprotein analysis plays a vital role in drug preparation. Thus, characterization of glycans that are linked to proteins has become necessary in glycoproteomics. Mass spectrometry has become an effective analytical technique for glycoproteomics analysis because of its high throughput and sensitivity. The large amount of spectral data collected in a mass spectrometry experiment makes manual interpretation impossible and requires effective computational approaches for automated analysis. Different algorithmic solutions have been proposed to address the challenges in glycoproteomics …

Characterization Of The Catalytic Ck2 Subunits With Substitutions At Residues Involved In Inhibitor Binding, Paul Desormeaux

Electronic Thesis and Dissertation Repository

CK2 is a constitutively active, ubiquitously expressed and pleiotropic serine/threonine protein kinase that is implicated in many cellular functions including tumorigenesis. CK2 has two catalytic subunits, CK2a and CK2a’, that carry out its function in the cell. Previous studies have indicated that inhibitor-refractory mutants have been effective in recovering residual CK2 activity, in the presence of inhibitors, when compared to wild type CK2. Based on these observations, inhibitor-refractory mutants were created for both CK2a and CK2a’ and tested with various concentrations with two CK2-specific inhibitors, CX-4945 and inhibitor VIII. The CK2a triple mutant (V66A/I174A/H160D) was tested in inducible U2OS Flp-In …

Effect Of Terminal Haptic Feedback On The Sensorimotor Control Of Visually And Tactile-Guided Grasping, Shirin Davarpanah Jazi

Electronic Thesis and Dissertation Repository

When grasping a physical object, the sensorimotor system is able to specify grip aperture via absolute sensory information. In contrast, grasping to a location previously occupied by (no-target pantomime-grasp) or adjacent to (spatially dissociated pantomime-grasp) an object results in the specification of grip aperture via relative sensory information. It is important to recognize that grasping a physical object and pantomime-grasping differ not only in terms of their spatial properties but also with respect to the availability of haptic feedback. Thus, the objective of this dissertation was to investigate how terminal haptic feedback influences the underlying mechanisms that support goal-directed grasping …

The Role Of Gaba Signalling In Lung Macrophage Immune Response, Jacob W. Poirier

Electronic Thesis and Dissertation Repository

Lung macrophages (LMϕs) play a key role in pulmonary innate immunity. They polarize into different phenotypes adapting to the needs of the immediate pulmonary environment. Studies in our laboratory suggest that murine LMϕs are endowed with an autocrine gamma-aminobutyric acid (GABA) signaling system. My honors thesis study found that antagonizing the autocrine GABA signaling in alveolar macrophages (AMϕs) increased secretion of the M1 cytokine tumor necrosis factor-alpha (TNF-α), suggesting a role for GABA signaling in immune response. This project explored whether GABA signaling plays a role in LMϕ polarization. Results from this study confirmed that bacterial toxin lipopolysaccharide (LPS) and …

Contribution Of The Primate Frontal Cortex To Eye Movements And Neuronal Activity In The Superior Colliculus, Tyler R. Peel

Electronic Thesis and Dissertation Repository

Humans and non-human primates must precisely align the eyes on an object to view it with high visual acuity. An important role of the oculomotor system is to generate accurate eye movements, such as saccades, toward a target. Given that each eye has only six muscles that rotate the eye in three degrees of freedom, this relatively simple volitional movement has allowed researchers to well-characterize the brain areas involved in their generation. In particular, the midbrain Superior Colliculus (SC), is recognized as having a primary role in the generation of visually-guided saccades via the integration of sensory and cognitive information. …

Using Mutual Information To Reprogram Dna Specificity Of Laglidadg Endonucleases, Marcon Laforet

Electronic Thesis and Dissertation Repository

A systematic approach to reprogram protein-DNA interactions has yet to be discovered. This study investigates the ability of co-variation analyses to identify potential protein-DNA contacts that regulate specificity. Here, 27 LAGLIDADG Homing Endonucleases (LHEs) and their 22-basepair DNA targets were collated into a Multiple Sequence Alignment (MSA) that was subjected to pairwise co-variation calculations. Using the LHE I-OnuI as a reference, an amino acid-DNA pair, lysine (K) 231 and adenine +3, generated the highest score. To test if the K231/A3 score was biologically relevant we tested protein mutants for altered nuclease specificity at +3 DNA point mutants. Randomizing the 231 …

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 …

A Model-Based Test Of The Efficacy Of A Simple Rule For Predicting Adaptive Sex Allocation, Joshua D. Dunn

Electronic Thesis and Dissertation Repository

The division of resources between male and female reproductive function is defined as sex allocation. The usefulness of simple rules to predict adaptive sex-allocation decisions has been a contentious topic. Simple rules are difficult to apply when the biological details of the life cycle are complex, as is the case in many vertebrates. We build a mathematical-computational model to investigate the usefulness of a simple rule that predicts adaptive sex-allocation decisions. We find that the simple rule is a better predictor of adaptive sex-allocation decisions when more features of an organism's life cycle are assumed to evolve. Even though the …

The Neuroprotective Effects Of Endurance Training On The Aging Brain, Katelyn Norton

Electronic Thesis and Dissertation Repository

Dysregulation of autonomic control often develops with advancing age, favoring a chronic state of heightened sympathetic outflow with parasympathetic withdrawal. However, the mechanisms of this age-related autonomic impairment are not known and may relate to alterations in brain structure (e.g. cortical atrophy) and/or altered neural function, particularly in regions related to the cortical autonomic network, namely, the medial prefrontal cortex (MPFC), insula cortex (IC), and hippocampus (HC). Exercise exerts beneficial effects on brain structure and, in the case of cognition, neurologic function; however, how exercise affects regions of the brain related to autonomic function are not known. This thesis tested …

Gait Real-Time Analysis Interactive Lab: Reliability And Validity Of Knee Angles And Moments In Patients With Knee Osteoarthritis, Ryan Pinto

Electronic Thesis and Dissertation Repository

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Abstract

Objectives: 1) Estimate test-retest reliability of knee angles and moments during gait in patients with knee osteoarthritis (OA) using the Gait Real-Time Analysis Interactive Lab (GRAIL); 2) Examine concurrent validity of knee angles and moments using the GRAIL and overground system (gold standard); and 3) Examine known-groups validity of knee angles and moments in patients with knee OA and healthy ontrols.

Methods: Patients and controls walked using both systems to produce knee angle and moment waveforms during stance, enabling discrete measure comparisons. atients completed a second session within one week.

Results: Intraclass correlation coefficients ranged from 0.52-to-0.93 for …

Indicator Amino Acid Derived Estimates Of Dietary Protein Requirement In Exercise-Trained Individuals, Arash Bandegan

Electronic Thesis and Dissertation Repository

Despite a number of nitrogen balance (NB) studies indicating increased dietary protein needs in Endurance (ET) and strength (ST) trained athletes, the Institute of Medicine (2005) has concluded, based largely on methodological concerns, that “no additional dietary protein is suggested for healthy adults undertaking resistance or endurance exercise”. Indicator amino acid oxidation method (IAAO) has been recently used for determination of protein requirement in humans. This method is based on the concept that when one indispensable amino acid (AA) is deficient for protein synthesis, then all other AA, including the indicator, will be considered excess and oxidized. With increasing intakes …

Using An Aerial Drone To Examine Lateral Movement In Sweep Rowers, Joseph S. Munn

Electronic Thesis and Dissertation Repository

Rowing is a sport that is performed on the water, because of this there are many challenges associated with studying rowing. The primary challenges are an inability to control the environment and limitations with the equipment that can be used to collect data on the water. In order to try and overcome some of these challenges an aerial drone fitted with a high resolution camera was used to examine an understudied element of the rowing stroke, lateral movement in sweep rowers. Oar and shoulder angles and lateral movement of the shoulders and hands were calculated and compared between five different …

First Major Appearance Of Brachiopod-Dominated Benthic Shelly Communities In The Reef Ecosystem During The Early Silurian, Cale A.C. Gushulak

Electronic Thesis and Dissertation Repository

The early Silurian reefs of the Attawapiskat Formation in the Hudson Bay Basin preserved the oldest record of major invasion of the coral-stromatoporoid skeletal reefs by brachiopods and other marine shelly benthos, providing an excellent opportunity for studying the early evolution, functional morphology, and community organization of the rich and diverse reef-dwelling brachiopods. Biometric and multivariate analysis demonstrate that the reef-dwelling Pentameroides septentrionalis evolved from the level-bottom-dwelling Pentameroides subrectus to develop a larger and more globular shell. The reef-dwelling brachiopods in the paleoequatorial Hudson Bay Basin were more diverse than contemporaneous higher latitude reef-dwelling brachiopod faunas, with ten distinct …

Evaluating The Interaction Between Buckwheat, Fagopyrum Esculentum (Polygonaceae) And Wireworm Agriotes Sputator L. (Coleoptera: Elateridae), Yeritza L. Bohorquez

Electronic Thesis and Dissertation Repository

Laboratory experiments were carried out to determine if buckwheat, Fagopyrum esculentum, produces phytochemicals that act as deterrents, anti-feedants, or toxins against Agriotes sputator wireworms. Choice assays were conducted to test the attractiveness of germinating, branching and flowering buckwheat, red spring wheat (Triticum spp) and island barley (Hordeum vulgare) to the larvae. There was no evidence that the wireworms were deterred by buckwheat and the germinating stage of all three crops was the most attractive. Twenty-one day, no choice feeding assays were conducted to determine change in mass and mortality of A. sputator larvae when fed buckwheat or …

An Investigation Of The Plant Growth Promoting Abilities Of Pseudomonas Fluorescens Uw4 Under Toxic Metal Stress, Joshua J. Frank

Electronic Thesis and Dissertation Repository

I investigated plant-microbe-metal interactions under metal stress. In theory, plant growth promoting rhizobacteria (PGPR) promote plant growth by reducing stress ethylene and synthesizing indole-3-acetic acid (IAA). The putative PGPR Pseudomonas fluorescens UW4 and a mutant strain that lacked an enzyme critical to the reduction of plant ethylene were studied to determine if they could promote Arabidopsis thaliana growth under cadmium and copper stress conditions. Both strains of P. fluorescens UW4 adhered to roots and synthesized IAA, and the wild-type lowered metal stress-induced ethylene in Arabidopsis, but neither strain enhanced plant growth. Wildtype P. fluorescens UW4 and its mutant had …

Telomere Length Variation In Preschool Children: Associations With Chronic Family Stress, Maternal Depression, And Cortisol Reactivity, Aditi Thakur

Electronic Thesis and Dissertation Repository

Telomeres are repetitive nucleotide repeats of TTAGGG sequences located at the two ends of each chromosome. Telomeres protect DNA from degradation and maintain genomic stability. Shorter telomeres are implicated in different diseases and disorders including psychiatric disorders. I measured buccal cell telomere length (TL) in 384 pre-school children (3-4 years), from Southwestern Ontario using monochrome multiplex qPCR method. I assessed the associations between TL and family, child-specific variables. I did not find a significant correlation between TL and maternal depression, chronic family stress, or age and sex of the children. However, I found a significant positive correlation between TL and …

Constraining Kinematics During Single-Leg Squats And Step-Ups Can Reduce Quadratus Lumborum Activation And Facilitate Gluteal Activation, Shaylyn Kowalchuk

Electronic Thesis and Dissertation Repository

Increased quadratus lumborum activation and decreased gluteal activation may lead to lateral pelvic drop and increased hip adduction and internal rotation during single-leg exercises. These activation patterns and motions are associated with low back pain or lower extremity injuries. The purpose of this study was to evaluate if mechanically restricting hip adduction and internal rotation of the femur affected muscle activation. Twenty female track and field athletes performed single-leg squats and step-ups, and the quadratus lumborum, gluteus medius and maximus muscles activations were measured with surface electromyography. This study tested the hypothesis that mechanically restricted exercises would decrease quadratus lumborum …

Iron Acquisition Strategies Employed By Staphylococcus Lugdunensis, Jeremy R. Brozyna

Electronic Thesis and Dissertation Repository

Iron is crucial for many cellular processes including DNA synthesis and respiration. The majority of iron in mammals is in heme within hemoproteins, inside cells, or transported through circulation by the glycoprotein transferrin, which constitutes the greatest iron source in serum. Limiting iron availability is an important facet of nutritional immunity to help prevent infection.

Staphylococcus lugdunensis is a human skin commensal and opportunistic pathogen capable of causing a variety of infections, including particularly aggressive endocarditis. It is an emerging pathogen with elevated virulence compared to other species of coagulase-negative staphylococci. The versatility of S. lugdunensis to infect multiple niches …

Multi-Gene Resistance To Neonicotinoids In The Colorado Potato Beetle, Leptinotarsa Decemlineata, Emine Kaplanoglu

Electronic Thesis and Dissertation Repository

The Colorado potato beetle, Leptinotarsa decemlineata, is a significant pest of potato, and its impact on agriculture is measured on a global scale. The beetle is mainly controlled by neonicotinoid insecticides, however, resistance development is a growing concern. Resistance to neonicotinoids is thought to involve elevated activity of detoxifying enzymes and xenobiotic transporters that break-down and excrete insecticide molecules. Here, using mRNA sequencing, I identified multiple detoxifying enzyme and xenobiotic transporter genes transcriptionally up-regulated in a neonicotinoid resistant strain of beetles. I then used RNA interference to knock down the transcript levels of the ten most promising genes in …

Effects Of Aging And Coronary Artery Disease On Sympathetic Neural Recruitment Strategies During End-Inspiratory And End-Expiratory Apnea, Mark B. Badrov, Sophie Lalande, T Dylan Olver, Neville Suskin, J Kevin Shoemaker

Kinesiology Publications

In response to acute physiological stress, the sympathetic nervous system modifies neural outflow through increased firing frequency of lower-threshold axons, recruitment of latent subpopulations of higher-threshold axons, and/or acute modifications of synaptic delays. Aging and coronary artery disease (CAD) often modify efferent muscle sympathetic nerve activity (MSNA). Therefore, we investigated whether CAD (n = 14; 61 ± 10 yr) and/or healthy aging without CAD (OH; n = 14; 59 ± 9 yr) modified these recruitment strategies that normally are observed in young healthy (YH; n = 14; 25 ± 3 yr) individuals. MSNA (microneurography) was measured at baseline and during …

Role Of Spinophilin In Group I Metabotropic Glutamate Receptor Endocytosis, Signaling, And Synaptic Plasticity, Andrea R. Di Sebastiano, Sandra Fahim, Henry A. Dunn, Cornelia Walther, Fabiola M. Ribeiro, Sean P. Cregan, Stephane Angers, Susanne Schmid, Stephen S. G. Ferguson

Anatomy and Cell Biology Publications

Activation of Group I metabotropic glutamate receptors (mGluRs) activates signaling cascades, resulting in calcium release from intracellular stores, ERK1/2 activation, and long term changes in synaptic activity that are implicated in learning, memory, and neurodegenerative diseases. As such, elucidating the molecular mechanisms underlying Group I mGluR signaling is important for understanding physiological responses initiated by the activation of these receptors. In the current study, we identify the multifunctional scaffolding protein spinophilin as a novel Group I mGluR-interacting protein. We demonstrate that spinophilin interacts with the C-terminal tail and second intracellular loop of Group I mGluRs. Furthermore, we show that interaction …

The Cardiovascular Benefits Of Regular Exercise In Type 1 Diabetes Mellitus And The Risk Of Exercise-Induced Hypoglycemia, Matthew W. Mcdonald

Electronic Thesis and Dissertation Repository

Type 1 diabetes mellitus (T1DM) is associated with compromised glycemic control and a heightened risk for cardiovascular disease. The common treatment of T1DM with strict glycemic control through intensive insulin therapy can be problematic (weight gain, insulin resistance, hypoglycemia). Regular exercise is known to improve cardiovascular health, yet most individuals with T1DM remain sedentary, and identify the risk of exercise-induced hypoglycemia as a significant barrier. The investigation into the use of different forms of exercise (higher intensity, resistance) for preventing exercise-induced hypoglycemia in populations with T1DM has been promising, however, little work has investigated their cardiovascular benefit or whether the …