Life Sciences Commons^™

Spatial Memory And Executive Functioning In The Goto-Kakizaki Rat Model Of Diabetes, Lorielle Dietze

Theses and Dissertations (Comprehensive)

Type 2 diabetes mellitus is a disease that adversely affects cognitive function in areas extending to memory and executive functioning. The Goto-Kakizaki (GK) rat provides a model of type 2 diabetes that can illustrate the mechanisms by which this disease works. The present study compared hyperglycaemic GK rats and age-matched Wistar rats in the Morris water maze to assess spatial memory, and in a perceptual attentional set-shifting task to assess putative prefrontal-dependent executive functioning. Results showed there was no difference in path length during training trials, however, GK and Wistar rats differed in the path length travelled in the target …

Impacts Of Transportation Infrastructure On Water Quality, Sediment Loads, And Fishing Opportunities In The Gwich’In Settlement Area, Northwest Territories, Matthew Teillet

Theses and Dissertations (Comprehensive)

The addition of gravel sediment to build ferry landings on the Peel and Mackenzie Rivers has been an ongoing concern for the Gwich’in communities of Fort McPherson and Tsiigehtchic that depend on the rivers for their livelihoods. Specifically, there are concerns that gravel from ferry landings is degrading water quality, harming fishing opportunities, and altering river morphology downstream. Previous reports concluded that ferry operations were not impacting downstream ecology. However, past studies had methodological shortcomings and community concerns about the ferry landings remain. To study the impact of the gravel landings on water quality, I utilized a multidisciplinary study design …

Effects Of An Acute Session Of High- Vs Low-Load Resistance Training Exercise On Energy Balance, Daniel Grisebach, Derek Pd Bornath, Abigail A. Broad, Seth F. Mccarthy, Tom J. Hazell

Theses and Dissertations (Comprehensive)

This study examined the effect of an acute session of low-load high-volume resistance training versus a more traditional high-load low-volume session on energy balance (EB). Five recreationally active males (age: 24±3 y; BMI: 25.8±1.5 kgm^-2) completed three different sessions: 1) high-load (90% 1RM); 2) low-load (30% 1RM); and 3) CTRL (no exercise). Gas exchange (V̇O₂), blood lactate, and subjective appetite perceptions were measured before each session, as well as at 0, 1, and 2 h post-exercise. Delayed onset muscle soreness (DOMS) in the quadriceps, pectorals, hamstrings, deltoids, and latissimus dorsi was measured at 24 and 48 …

Can Zooplankton On The North American Great Plains ‘Keep Up’ With Climate-Driven Salinity Change?, Mariam Elmarsafy

Theses and Dissertations (Comprehensive)

The Great Plains of North America are projected to become more arid as the climate changes over the next century. Salinity levels for lakes in this region are linked to climate, suggesting that lakes will become more saline as the climate becomes drier. One group of organisms that might be affected by increased salinity levels are the zooplankton, aquatic invertebrates that transfer energy from primary producers to macroinvertebrates and fish. Little is known about the ability of zooplankton to adapt to long-term increases in lake salinity levels. For my thesis, I used resurrection ecology to examine how a common zooplankter, …

Fall Reading Week: Exploring The Effects On Student Well-Being, Roobina Medhizadah

Theses and Dissertations (Comprehensive)

Mental health is a concerning issue in post-secondary institutions across Ontario. Post-secondary students are challenged with many stressors such as time management and living independently for the first time (Wagner & Rhee, 2013). In an attempt to help students, maintain or improve their mental health, universities across Ontario have implemented fall reading week, a mid-semester break (Poole et al., 2017). Previous studies (Cramer & Pschibul, 2017; Poole et al., 2017) provided mixed results in whether fall reading week positively influences student mental health and well-being. To date, few studies have explored the influence of fall reading week on student health …

Exploring Upper Limb Sequence Behaviours In Egocentric And Allocentric Reference Frames, Robyn Brooke Grunberg

Theses and Dissertations (Comprehensive)

Voluntary behaviours, such as reaching, are essential for manipulating and exploring our environment. The current body of literature, however, has predominantly investigated reach behaviours through tasks such as peg-moving, tapping, dotting, and circle drawing. The objective of this study was to investigate the order and direction of reaching behaviours in a sequential tapping task in both an egocentric and an allocentric reference frame. Gaze behaviours were observed to explore intent to reach in the sequential task. Implementing reference frames in an upper limb motor control task might be of clinical importance when exploring rehabilitation techniques post-traumatic brain injury. It was …

Using Phytoglycogen-Based Nanoparticles To Enhance Inosine Monophsophate Delivery Using Rainbow Trout And Bovine Models, Kristof Jenik

Theses and Dissertations (Comprehensive)

Recently, there has been interest in the use of nucleotides in industrials feeds, with inosine monophosphate showing the most promising effects on growth and immunity. Rainbow trout and Alberta cattle are two of Canadas most profitable farmed animals, if their growth rates and immunity could be enhanced this would further improve their value. The impacts of IMP, a phytoglycogen-based nanoparticle (NP) and inosine monophosphate cationically bound to the phytoglycogen-based nanoparticle (IMP-NP) were characterized in rainbow trout in vivo and in vitro and in vitro in bovine cells. Rainbow trout that were fed an IMP-NP containing feed on average had higher …

Toll-Like Receptor 4 Inhibition Differentially Impacts Intervertebral Disc Axial Mechanics In Wild Type And Sparc-Null Mice, Mitch Whittal

Theses and Dissertations (Comprehensive)

Study Design. In vivo examination of the influence of TAK-242 (resatorvid) treatment on the mechanical properties of the intervertebral disc (IVD) in secreted protein acidic and rich in cysteine (SPARC) gene knockout (SPARC-null) mice.

Objectives. To examine if chronic TAK-242 treatment mitigates mechanical degradation associated with IVD degeneration in SPARC-null mice.

Summary of Background data. IVD degeneration is associated with low back pain (LBP) and is accompanied by mechanical changes to the spine. SPARC is a protein that contributes to the functioning and maintenance of the extracellular matrix (ECM), with SPARC-null mice displaying accelerated IVD degeneration. TAK-242 is a toll-like …

Hydrogen Peroxide: A Grower’S Best Friend?, Mitchell Eicher-Sodo

Theses and Dissertations (Comprehensive)

Hydrogen peroxide (H₂O₂) is an oxidizing agent used to disinfect irrigation systems (e.g. nutrient solution and equipment) used in controlled environment plant production and produces no harmful by-products. The action of H₂O₂ is non-selective, and therefor H₂O₂ will oxidize all components of the irrigation water as well as tissues from the greenhouse crops being irrigated. The phytotoxic effect H₂O₂ has on common greenhouse crops is not well understood, requiring detailed characterization and determination of threshold concentrations. Thresholds within the thesis were based on applied H₂O …

Effects Of Phosphorus On Mycorrhizal Colonization Of Wetland Plants Under Natural And Controlled Conditions, Miriah Tucker

Theses and Dissertations (Comprehensive)

An important symbiotic relationship that forms in wetland environments occurs between plants and arbuscular mycorrhizal fungi (AMF). In terrestrial communities AMF colonization is limited by phosphorus; excessive phosphorus can lead to an uncoupling of the relationship. Few studies have examined the relationship between AMF and phosphorus concentration in wetland plants. The studies that have, found a decrease in AMF colonization at phosphorus concentrations as low as 0.03 mg/L P, however, methodological issues limit the interpretation of these results. To address this, a field and greenhouse study were completed using more realistic exposure conditions, field deployable assays (FDA), and natural intact …

Spinal Motor Neuron Excitability And Balance Control Changes Following Downslope Walking, Nikki Aitcheson-Huehn

Theses and Dissertations (Comprehensive)

Downslope walking (DSW) has been proposed as a rehabilitation tool for people with Multiple Sclerosis (PwMS) although there are mixed findings in young adults (YA) regarding the balance control changes, despite both populations experiencing depressed spinal motor neuron (MN) pool excitability. Our aim was to determine whether YAs could demonstrate improved balance control in conjunction with SOL H reflex depression (estimate of spinal MN excitability) following DSW. We also aimed to determine whether reciprocal inhibition was a potential mechanism for H reflex depression via conditioned SOL H reflexes. Thirty young adults (23±1.4y, 6 males) were assigned to 30-minutes of DSW …

The Nature Of Informal Roles In Interdependent Sport Teams, Jeemin Kim

Theses and Dissertations (Comprehensive)

The degree to which athletes understand and execute their formal role responsibilities (i.e., prescribed by coaches) is important for individual and group functioning (Eys, Schinke, Surya, & Benson, 2014). Recent literature suggested that informal roles can emerge within sport teams more naturally without coaches’ explicit assignments (e.g., team comedians, distracters), and have significant influences on team functioning (Cope, Eys, Beauchamp, Schinke, & Bosselut, 2011). This doctoral dissertation examined the nature of informal roles within interdependent sport teams, focusing on their antecedents and outcomes. Three separate projects were conducted. Project One examined athletes’ personality in the big five dimensions (McCrae & …

A Genomic Investigation Of The Stomach Phenotype In Teleosts, Louis Pfeifer

Theses and Dissertations (Comprehensive)

The stomach, which is physiologically defined in vertebrates by its function in acid-peptic digestion, has been lost independently multiple times during the evolution of the teleost fishes. The function of the stomach is facilitated by the proton pump H⁺/K⁺-ATPase, which acidifies the stomach, and pepsinogens, which are converted to proteolytic pepsins in this acidic environment. It is well documented that in agastric (stomachless) fish, the genes what code for the expression of this proton pump (atp4a and atp4b) and the pepsinogens (pga, pgb, pgf, pgc and cym,) are absent from the genome …

The Effects Of Dorsal Lateral Telencephalon Lesions On Zebrafish Social Behaviour, Hailey Katzman

Theses and Dissertations (Comprehensive)

Zebrafish are extremely social and aggregate in groups to form shoals. This social behaviour has been studied in the wild and in a laboratory setting, yet the mechanisms underlying the behaviour are unknown. There is evidence to suggest that the dorsal lateral telencephalon might play a role in shaping shoaling behaviour, being involved in modulating social behaviours and social reward associated with shoaling. In the current thesis, I adapted and combined several existing methods for performing lesions on the dorsal lateral telencephalon to create my own method to measure the role of the dorsal lateral telencephalon in social reward and …

Beyond A Mapping Exercise: Inclusion Of Aboriginal Traditional Ecological Knowledge In Parks And Protected Areas Management, David Cook

Theses and Dissertations (Comprehensive)

This paper examines current approaches for Parks and Protected Areas (PPA) managers in incorporating Aboriginal Traditional and Ecological Knowledge (ATEK) into their management plans. This paper focuses on two case-studies. They are Nahanni National Park and Reserve in the Dehcho region of the Northwest Territories, and the Whitefeather Forest Protected Area in the Pikangikum First Nations Traditional Territory in Ontario. They were chosen because of their unique approaches to include Aboriginal communities in the planning process and their designation as UNESCO World Heritage sites. The broader indigenous involvement policies of both Parks Canada and Ontario Parks are examined using academic …

A Qualitative Investigation Into The Influence Of A Mental Health Physical Activity Intervention On University Students, Heather M. Tunks

Theses and Dissertations (Comprehensive)

Objective

Among the university student population, mental illnesses are highly prevalent. Adults aged 20-30 years have the highest rates of mood and anxiety disorders than any other age group, with approximately 12.0% diagnosed with an anxiety disorder and 7.0 to 9.0% experiencing clinical depression (Nunes et al., 2014; Pedrelli, Nyer, Yeung, Zulauf, & Wilens, 2015). Reducing or preventing the effects of mental illness among this population may have lifelong implications including improvements in coping and management of mental illness throughout the lifespan(Jaworska, DeSomma, Fonseka, Heck, & MacQueen, 2016). This research examines the lived experiences of volunteers and participants in a …

Abiotic Conditions, Algal Biomass & Fish Growth Rates Affect Fish Mercury Concentrations In Two Subarctic Lakes, Ari Yamaguchi

Theses and Dissertations (Comprehensive)

Kakisa Lake and Tathlina Lake, located in the Dehcho Region of the Northwest Territories, support important fisheries for the local Ka’a’gee Tu First Nation (KTFN). Recently, Walleye (Sander vitreus) of typical catch size in Tathlina Lake were found to have mercury concentrations above Health Canada’s commercial sale guideline of 0.5 ppm. Wild foods with elevated mercury concentrations can pose health risks to the humans who consume them, depending on consumption amounts and vulnerability factors such as age and pregnancy. Because wild fish can accumulate relatively high mercury levels and subsistence fishing contributes greatly to food security in northern …

Structural And Functional Characterization Of Cazyme And Cazyme-Related Proteins From: Bacteroides Thetaiotaomicron And Porphyromonas Gingivalis: Two Abundant Colonizers Of The Human Microbiome, James Stevenson

Theses and Dissertations (Comprehensive)

The human body consists of approximately 30 trillion cells, while non-human microbes that reside on and within the body outnumber human somatic cells by a factor of 1.3 – 2.3. The interplay between our cells and those of the colonizing microorganisms affect physiology in a multitude of ways, both beneficial and detrimental. Microbes found in the oral cavity, such as the Red Complex member Porphyromonas gingivalis, are associated with pathology, namely periodontal diseases including gum deterioration, tooth decay, and loss of underlying alveolar bone. At the other end of the gastrointestinal tract, microbes such as Bacteroides thetaiotaomicron are found …

What Makes An Image Memorable? Effects Of Encoding On The Mechanism Of Recognition, Asiya Gul

Theses and Dissertations (Comprehensive)

Memory is undoubtedly one of the most important processes of human cognition. A long line of research suggests that recognition relies on the assessment of two explicit memory phenomena: familiarity and recollection. Researchers who support the Dual Process Signal Detection (DPSD) model of recognition memory link the FN400 component (a negative ERP deflection peaking around 400 ms at frontal electrodes) with familiarity; however, it is currently unclear whether the FN400 reflects familiarity or implicit memory. Three event-related potentials (ERP) studies were conducted to determine whether implicit memory plays a role in setting up encoding strategies, and how these encoding strategies …

Influence Of Salinity On Copper-Ligand Formation Constants, Fatimah Barnawi

Theses and Dissertations (Comprehensive)

Natural Organic Matter (NOM) is known to reduce metal, such as copper, toxicity in aquatic environments. Copper is essential for organisms, but elevated concentrations of dissolved copper can potentially be toxic. The toxicity of copper is related to its bioavailability, which is influenced by toxicity modifying factors, such as NOM (quantified as Dissolved Organic Carbon (DOC) in mg C/L), alkalinity, pH and major cation and anion concentrations. The principles are the same for fresh and saltwater, but the influence of high salt concentrations, such as in estuaries, and associated activity corrections, can modify NOM complexation of metals (i.e., modify logK …

Boreal Subarctic Lake Water Quality, Zooplankton Communities, And Benthic Macroinvertebrate Communities In Areas Impacted By Wildfire, Thomas J. Pretty

Theses and Dissertations (Comprehensive)

Wildfires are a natural phenomenon in the boreal forest, but recent studies suggest that there will be increases in the frequency and severity of fires in this region over the next century. When wildfires occur in lake catchments, they may affect water quality and invertebrate communities living in associated lakes. Invertebrates, including zooplankton and benthic invertebrates, play important roles in aquatic food webs, acting as conduits of energy from primary producers to larger organisms such as fish and water birds. Therefore, it is important to understand how these groups will respond to changes caused by fires. Unfortunately, few studies have …

“This Is My Little World…”: Navigating The Group Exercise Experience Of Stay-Fit Members, Olivia Jones

Theses and Dissertations (Comprehensive)

Objective

Cancer is the leading cause of death in Canada, with one in two Canadians expected to develop cancer over their lifetime (Canadian Cancer Society, 2019). Exercise is reportedly a safe therapy to help ease the common side effects of cancer and its treatments (Schmitz et al., 2010). Past research has shown the benefits of group exercise while in treatment for cancer, but there is a dearth of research regarding the impact of long-term group exercise programming for cancer survivors. This phenomenological study explored the lived experiences of group exercise participation for individuals who previously had cancer and were enrolled …

Effects And Modes Of Action Of Exogenous Androgens On Gonadal Steroidogenesis In Male Mummichog (Fundulus Heteroclitus), Robert Rutherford

Theses and Dissertations (Comprehensive)

Androgens are a recognized class of endocrine disrupting compounds that are introduced into the aquatic environment through a variety of anthropogenic sources. Exogenous androgens can interact with the hypothalamus-pituitary-gonadal (HPG) axis in fish and alter its normal function, resulting in effects such as skewed sex ratios, intersex individuals, reduced fecundity, or altered mating behaviours. In fish, these apical effects are commonly correlated to depression of the terminal sex hormones testosterone, 17β-estradiol and 11-ketotestosterone (11KT). It is currently thought that the reduction in plasma sex hormones is an effect of negative feedback inhibition of steroid synthesis within the HPG axis after …

Examining Disability In The Region Of Waterloo: Physical Activity Programming And Caregiving, Nicole J. Reinders Luymes

Theses and Dissertations (Comprehensive)

Physical activity (PA) is a necessary component of wellbeing for individuals with and without disabilities. Disabled young people experience many barriers to PA, resulting in inactive lifestyles that compound health issues and hinder their full participation in schools and communities. The following dissertation includes a literature review regarding the effects of PA for young people with a variety of developmental disabilities, in addition to three research studies examining community-based PA programming, and one study exploring the lived experiences of caregivers, all within the Region of Waterloo.

The first study was a needs assessment to examine PA perceptions, practices, barriers, and …

Examining The Effect Of Exercise Intensity On Post-Exercise Hypotension In Middle-Aged Adults, Seth F. Mccarthy

Theses and Dissertations (Comprehensive)

Acute bouts of exercise have a transient lowering effect on systolic blood pressure (SBP) and diastolic blood pressure (DBP) in the hours after termed post-exercise hypotension (PEH). While moderate-intensity continuous training (MICT) is effective in reducing BP acutely, little is known regarding the effects of higher intensity exercise. This study examined the effects of different exercise intensities on PEH. Six participants (females: 4; age: 48±9 y, Mean arterial pressure: 84±8 mmHg) had their BP measured before and both immediately post- (<2 h) and for 24 h following 4 experimental sessions: 1) 30 min MICT (65% V̇O_2max); 2) 20 min high-intensity interval training (HIIT; 10 x 1 min @ 90% HR_max with 1 …

Assessing Threats And Mitigation For Scarlet Ammannia (Ammannia Robusta) In Southwestern Ontario, Kayla Salive

Theses and Dissertations (Comprehensive)

Scarlet Ammannia (Ammannia robusta) is an annual emergent wetland plant of the Lythraceae family. Throughout most of its distribution, the species population is stable under present conditions. However, this is not the case in Canada, where A. robusta is considered endangered with only a few small populations documented in British Columbia and Ontario. In response, a recovery strategy was created for A. robusta outlining the lack of information on the species biology and ecology, with a primary objective to assess the populations in Ontario and gain information on what may be contributing to the species rarity. To assess …

Investigation Of Rna Interference (Rnai)-Mediated Gene Silencing In Rainbow Trout, Sarah Au

Theses and Dissertations (Comprehensive)

RNA interference (RNAi) was first characterized in plants and invertebrates as an antiviral innate immune response. It is a natural antiviral defence mechanism to degrade viral RNA by virus-induced gene silencing. Studies showed synthetic long double-stranded RNA (dsRNA; >30bp) degraded Caenorhabditis elegans messenger RNA (mRNA) transcripts, resulting in sequence-dependent gene silencing. Currently, there is only limited research on RNAi in fish, particularly the use of long dsRNA to trigger sequence-specific gene silencing. This is because studies have shown long dsRNAs trigger interferon response that could mask gene-specific RNAi effects. This thesis explored long dsRNA-mediated RNAi pathways in rainbow trout cells …

Synthesis And Biophysical Analysis Of The Cell-Penetrating Peptide Penetratin And Its Aromatic Analogues, An Le

Theses and Dissertations (Comprehensive)

Cell-penetrating peptides (CPPs) interact with biological membranes, undergo cellular intake/uptake, and may act as potential drug delivery agents. Understanding the molecular interactions of these peptides with membranes contributes to gaining a better knowledge of their potential use in medical and pharmaceutical applications to improve human health. The current research focuses on understanding the mechanisms of a CPP in interaction with different model phospholipid membranes. The peptide penetratin (primary sequence: RQIKIWFQNRRMKWKK) is an example of a CPP that can interact with and pass through biological membranes. The current thesis provides spectroscopic and calorimetric evidence that penetratin associates with lipid membranes. Circular …

The Role Of Streptococci In Oral Periodontitis: Growth And Disruption Of Yellow Complex Bacteria, Megan Gordon

Theses and Dissertations (Comprehensive)

Periodontitis is described as the inflammation of the periodontium and affects millions of people worldwide. This disease is caused by biofilm growth of certain bacteria on the tooth surface, adjacent to the gum tissue in the oral cavity. There are currently treatments against severe periodontitis, such as oral surgery and use of broad-spectrum antibiotics, but they fail to target the specific bacteria associated with periodontitis. Socransky et al., (1998), identified the preponderance for specific organisms in distinct areas of the subgingival pockets to associate with different bacteria forming consortia and complexes. The yellow complex, containing facultatively anaerobic, Gram positive …

Functional Characterization Of Proteins From A Putative Chondroitin Sulfate A Degrading Operon And The Crystal Structure Of An Exo-N-Acetylgalactosamine-4-Sulfatase From Tannerella Forsythia, Peter Nguyen

Theses and Dissertations (Comprehensive)

Advanced periodontitis has been shown to have strong associations with the residence of a bacterial triad of Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola also known as the red complex. These bacteria were previously thought to be asaccharolytic, making them better suited to survive in deep in periodontal pockets where access to carbohydrates from food is limited. Information gathered from genomic analysis suggested that upregulation of an operon (BFO2285-BFO2295, BFO3043) could confer the capacity for T. forsythia to degrade chondroitin-4-sulfate, the principle glycosaminoglycan of alveolar bone tissue. Bioinformatics analysis suggested the operon was similar to an operon found in Bacteroidetes …