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Impacts Of Environmental Stressors On Mummichog (Fundulus Heteroclitus) Growth And The Gh-Igf1 Pathway Using A Laboratory Bioassay, Olena Kuntyj

Theses and Dissertations (Comprehensive)

Using a flow-through laboratory bioassay, experiments investigated the effects of limited feeding, increased temperature, ammonium chloride (NH₄Cl), and 17α-ethinylestradiol (EE₂) on juvenile mummichog (Fundulus heteroclitus) growth. Weight measurements were taken every three days as the apical growth endpoint. Gene expression was examined by qPCR for genes in the GH (growth hormone)-IGF1 (insulin-like growth factor 1) pathway, including gh, igf1, and their receptors (ghra, ghrb, igf1ra, igf1rb). In Experiment 1, juvenile mummichog were exposed to excess or limited feed for 21 days. The limited-fed mummichog weighed less, were …

Synthesis And Biophysical Analysis Of Modified Cell-Penetrating Peptides, Joel Mitchell

Theses and Dissertations (Comprehensive)

Cell-penetrating peptides (CPPs) are a family of peptides that have the ability to penetrate biological membranes. They were discovered in the late 1980s and have been the topic of many studies. Much of the interest in CPPs has been due to their ability to translocate biological membranes, and the possibility that they could offer a novel drug delivery method by conjugation to biologically active molecules. Linear CPPs can be modified to form cyclic structures. This change in structure has been observed to enhance the stability and penetrative ability of the CPPs which have been studied. The current thesis focuses on …

Variation In Mainland Northwest Territories Late-Winter Muskox (Ovibos Moschatus) Density Estimations And Habitat Associations Above And Below Treeline., Charlotte Rentmeister

Theses and Dissertations (Comprehensive)

The Arctic and Sub-Arctic ecosystems are seeing accelerated changes in temperature, landcover, and consequently species abundance and distributions. Reliable distributions, and associated population density estimates, are essential for effective conservation and management efforts. Growing concerns from northern communities regarding the relationship between muskox and declining caribou populations strengthens the need for updated information on muskox populations within mainland Northwest Territories (NWT). The first objective for my research was to quantify and map updated winter estimates of abundance, density, and distribution of muskoxen within three recent survey regions located in mainland NWT, using a multiple covariate distance sampling method (MCDS), paired …

The Characterization Of Vig-1’S Expression Patterns In Ipnv-Infected, Or Dsrna-Treated, Rainbow Trout Cells, Samantha Lum

Theses and Dissertations (Comprehensive)

In Canada, annual trout production is valued at over $60M with approximately 10,000 tonnes of trout produced per year. Rainbow trout (Oncorhynchus mykiss) are one of the most commonly farmed fresh-water fish in Canada. The high-density farming practices involved in aquaculture increase rainbow trout susceptibility to aquatic viruses such as infectious pancreatic necrosis virus (IPNV). The innate antiviral immune response in rainbow trout is poorly characterized, and the functions of numerous interferon stimulated genes (ISG) in rainbow trout remain unclear. One such gene, virus-induced gene 1 (vig-1) has been poorly studied; however, the human orthologue for vig-1 …

Comparing Ionoregulation And Modes Of Nitrogen Excretion Across The Life Cycle Of Parasitic And Non-Parasitic Lamprey Species, Shannon Davidson

Theses and Dissertations (Comprehensive)

Abstract

Ionoregulation and nitrogenous waste (N-waste) metabolism in fishes has been extensively documented in teleosts and elasmobranchs, but less so in lampreys (Petromizontiformes). All lamprey species undergo metamorphosis which drastically changes their physiology and modes of feeding. However, differences in ionoregulatory mechanisms due to anadromous versus non anadromous life history strategies emerge following metamorphosis in different lamprey species. Furthermore, some species, such as anadromous juvenile sea lamprey (Petromyzon marinus), are parasitic and migrate to seawater (SW) to ingest blood protein from host fishes, while juveniles of freshwater (FW), non-parasitic species, such as the American brook lamprey …

Understanding The Significance Of Object Recognition In Cowbirds: Exploring The Interplay Of Cognition, Social Behaviour And Reproductive Success, Eric Rushton

Theses and Dissertations (Comprehensive)

Every day, animals use cognitive processes to make decisions in their environment such as those regarding food sources, threats and mates. One such important process provides the ability to recognize objects and individuals in order to guide future actions. Since object recognition and individual recognition are related processes, they may be linked to social cognition and to fitness; links not commonly explored in the literature. In this thesis I seek to examine (1) how brown-headed cowbirds (Molothrus ater) attend to and react to novel objects in their environment and (2) how this ability to recognize objects is related …

Potential Effects Of Road Proximity On Zooplankton Communities And Water Quality In Lakes In The Northwest Territories, Marie N. Hannan

Theses and Dissertations (Comprehensive)

Studies conducted along Canada’s Dempster Highway in the Northwest Territories have shown that road dust can affect water quality in roadside lakes, leading to higher calcium, conductivity, and pH levels. These water quality changes have the potential to affect important members of the lower aquatic food web, such as zooplankton.

For my thesis research, I had two main objectives: 1) To determine if changes in water chemistry caused by deposition of road dust affects zooplankton communities; and 2) To examine if the type of roadside vegetation influences the effects of road dust on aquatic habitats. To achieve these objectives, I …

Investigating The Effects Of Disturbance And Competition On Establishment, Growth, And Reproduction Of The Endangered Ripariosida Hermaphrodita, Daniel Engelking

Theses and Dissertations (Comprehensive)

Ripariosida hermaphrodita (Virginia Mallow) is a perennial riparian plant with broad, maple-like leaves. It grows up to three meters high and is often found in large clonal patches, but sexually reproduces readily. While this plant may seem like a redoubtable competitor when growing in large colonies, it is declining across its range in North America. The only known occurrences in Canada are in southern Ontario. Prior to this study, no new populations had been recorded even though one of the known populations produces copious amounts of viable seed with potential to disperse. There are many hypotheses for its rarity, but …

Exploring The Membrane Protein And Peptide Interactions Of Mitochondrial And Bacterial Lipid Systems, George Saudan

Theses and Dissertations (Comprehensive)

This study aims to expand the understanding of interactions between membrane lipids and proteins, and relate it to their biological functions in two experimental systems. The first system focuses on the interaction and conformation of a membrane protein Uncoupling Protein 4 (UCP4) in mitochondrial inner membrane lipids, in the absence and presence of cardiolipin; a lipid specific to mitochondrial inner membranes. The second system considers the interaction and conformation of a cell penetrating peptide, Penetratin, which can interact with both mammalian and bacterial cells. A N- and C-termini protected form of this 16-meric peptide (Pen2) was used to explore its …

Discerning Friend From Foe: Systematic Revision Of Cuscuta L. Section Indecorae Using A Combined Ecological, Morphometric, And Phylogenetic Approach., Corey Burt

Theses and Dissertations (Comprehensive)

The genus Cuscuta (Dodder; Convolvulaceae) are obligate parasitic plants. In one clade known as section Indecorae, there are species which are considered pests that pose significant threats to agricultural crop production, while other species are rare or known only from historical records. Section Indecorae contains three species: C. coryli, C. warneri, and C. indecora (the latter with three infraspecific taxa: var. indecora, var. longisepala, and var. attenuata). The systematics of section Indecorae are not currently resolved. Cuscuta indecora has a long and complicated taxonomic history with many infraspecific varieties described, and …

Temperature Regulation Of Pipecolic Acid-Mediated Plant Systemic Immunity In Arabidopsis Thaliana, Alyssa Shields

Theses and Dissertations (Comprehensive)

Significant crop losses are caused by pathogenic infections annually, which are exacerbated by increasing global temperatures due to climate change. One way by which plants respond to pathogenic attacks is through the activation of pattern-triggered immunity (PTI), effector-triggered immunity (ETI), and systemic acquired resistance (SAR), which lead to production of the central defence phytohormone salicylic acid (SA). Accompanying SA release is the putative mobilization of pipecolic acid (Pip), which acts as an immune regulatory plant metabolite that works with and independently from SA. As demonstrated in the model plant Arabidopsis thaliana following infection with the model bacterial pathogen Pseudomonas syringae …

The Effect Of Alkalinity On Lampricide Effectiveness And Gill Physiology In Invasive Sea Lamprey (Petromyzon Marinus), Alexandre J. Walsh

Theses and Dissertations (Comprehensive)

The pesticides, 3-trifluoromethyl-4-nitrophenol (TFM) and niclosamide are used to control populations of invasive sea lamprey (Petromyzon marinus) in the Laurentian Great Lakes of North America. Added to streams infested with larval sea lamprey, the effectiveness of these pesticides, commonly called lampricides, are strongly influenced by water pH, with greater toxicity for both TFM and niclosamide in lower pH than higher pH water. However, the TFM and niclosamide sensitivity of sea lamprey are also greater in poorly buffered, low alkalinity water than in high alkalinity water but it is unclear why. One goal of my thesis was to propose …

Characterization Of The Clostridioides Difficile Glycosyl Hydrolase Ccsz, Brian Lowrance

Theses and Dissertations (Comprehensive)

Bacteria inhabit many of the harshest environments on Earth; persisting and thriving in conditions thought to be unsuitable for life. One common strategy to withstand these environments is the formation of a biofilm. Biofilm composition varies greatly, depending on the underlying community that produces it. Cellulose, a polymer consistently prevalent in biofilms, has been identified as a virulence factor in many pathogens and is suspected to be involved in pathogenesis by Clostridioides difficile. C. difficile is the #1 cause of hospital acquired diarrhea, which can range from mild to life-threatening infections. Biofilm formation is hypothesized to be involved in …

Vapourized Cannabis Extract Administration Impairs Memory And Alters Neural Activity In Laboratory Rats, Megan Chladny

Theses and Dissertations (Comprehensive)

Although people have smoked cannabis for millennia, administration of cannabis by heating the dried plant material or distilled extracts to a temperature just below the combustion point (i.e., vapourization or "vaping") has rapidly increased over the past few years (Javadi-Payder, Cole, and Taffe, 2018; Manwell, Charchoglyan, Brewer, Matthews, Heipel, and Mallet, 2014). Conversely, most of the cannabinoid research using rodent models has used parenteral routes of administration to examine the effects of purified cannabis extracts such as ∆⁹-tetrahydrocannabinol (THC), making it difficult to directly compare laboratory research to human drug use. Building on previous studies showing that THC …

Winter Dynamics Of Storm Water Management Ponds And Winter Tolerance In Three Aquatic Plant Species, Patrick Strzalkowski

Theses and Dissertations (Comprehensive)

The vast majority of the research into the performance of stormwater management ponds (SWMPs) has been performed in warm regions or during the warmer seasons in temperate regions. It is presumed that SWMPs are inactive in the winter as any potential stormwater is trapped in snow and ice. The main goal of this thesis was to test this presumption and to study the dynamics and performance of three SWMPs during the winter. Remote water level loggers were installed into the three SWMPs and daily grab samples from the influents and effluents were taken and analyzed for total phosphorus (TP), chloride, …

“Anything From The Land Is Good”: Understanding How Community Gardening In Kakisa, Northwest Territories, Can Contribute To Indigenous Food Sovereignty, Michelle Malandra

Theses and Dissertations (Comprehensive)

Rates of food insecurity in Canada’s northern Indigenous communities are at levels that should constitute an emergency. Dominant explanations for these high rates of food insecurity often ignore the ongoing impacts of colonization and over-emphasize individual choices and nutritional guidelines developed by outsiders. The importance of holistic community health is ignored, along with the cultural and social values and practices that support community health and well-being, including traditional food systems. As the acute impact of climate change in the North threatens traditional food access, a shift toward an Indigenous food sovereignty approach in health and food policy is needed. With …

Impact Of Orthophosphate As A Corrosion Inhibitor And Chloramine Disinfectant On Drinking Water Biofilm Communities, Mitchell Cooke

Theses and Dissertations (Comprehensive)

A drinking water distribution system (DWDS) must maintain conditions within quality standards which assure the effective and safe transport of finished drinking water from treatment plants to the household tap. Although safe to drink, finished water is not sterile, and may contain hundreds of microorganisms in a single milliliter. These microorganisms are present from the source waters, such as lakes, rivers and aquifers, and have passed through early treatment steps. Final treatment steps, such as the maintenance of disinfectant residuals, are used to further minimize viable cells present and focus on the reduction of harmful organisms. Microbial cells entering the …

Impacts Of Changing Permafrost Conditions On Vegetation Productivity In The Northern Boreal Forest, Emily Ogden

Theses and Dissertations (Comprehensive)

Vegetation productivity across the boreal forest has increased over the past several decades. However, at a regional scale there is large variation from increased (greening) to decreased (browning) productivity and large areas with no measured change. Some of this variation can be explained by disturbances, such as wildfire, or by increased climate variability. In northern regions underlain by permafrost, the interactions between climate, disturbance, and vegetation productivity may be more complex. For my thesis, I used a time-series of ground thermal data from permafrost monitoring sites established by the Geological Survey of Canada along a latitudinal transect of the Northwest …

Discovery Of Inhibitors Of Peptidoglycan O-Acetyltransferase B (Patb) From Neisseria Gonorrhoeae, A New Potential Antibacterial Target, Stefen Stangherlin

Theses and Dissertations (Comprehensive)

Experts project that by 2050, 10 million lives will be lost annually as a result of antimicrobial resistant infections, surpassing all current leading causes of death, and costing the global economy $100 trillion USD on healthcare efforts. To promote research and development of novel antibiotics, the World Health Organization and Centers for Disease Control and Prevention released a list of priority pathogens regarded as serious or urgent threats of antimicrobial resistance. Many pathogenic bacteria, including several priority pathogens, produce O-acetylated peptidoglycan to establish infection and avoid host immune responses. Consequently, the enzymes responsible for producing O-acetylated peptidoglycan in Gram-negative pathogenic …

Changes In Plant Community Composition, Structure, And Function In Response To Permafrost Thaw, Katherine Standen

Theses and Dissertations (Comprehensive)

Air temperature is increasing at three or more times the global average in high latitudes, causing widespread permafrost thaw across the boreal biome. Since the boreal biome stores 30-40% of global terrestrial carbon (C), of which about 30-45% is found in permafrost soils, this temperature increase could cause a large efflux of C to the atmosphere. Climate warming and permafrost thaw are also expected to alter plant community composition and productivity and, given the link between plant functional traits and ecosystem C fluxes, may alter overall ecosystem function. Across the boreal biome of western Canada, we know surprisingly little about …

The Electrophysiological Correlates Of Text Integration And Direct Vs. Indirect Articles: A Centralized And Lateralized Examination, Deanna C. Hall

Theses and Dissertations (Comprehensive)

As we read, we develop mental models of the discourse content called situation models. Situation models are integral to how we keep track of information, and to do so in an ongoing event incoming information needs to be integrated into the model or discarded. The type of information being presented, and its relation to prior data, impacts how that new information is processed. The current research examined discourse passages containing concepts that were either previously mentioned (match), mentioned with a general term (general category), unmentioned in lieu of another concept (mismatch), or completely unmentioned previously (indeterminate), and examined how these …

Arctic Stream Characteristics And Diet Analysis Choice Impact Condition And Diet Estimates Of Ninespine Stickleback (Pungitius Pungitius), Adam Kuhrt

Theses and Dissertations (Comprehensive)

Ninespine stickleback (Pungitius pungitius) are ubiquitous in circumpolar freshwaters, but their ecological role is not well understood. Little research has been conducted on the influence of environmental variables on ninespine stickleback in stream environments, and while they are understood to be generalist feeders, their diet in stream environments is equally understudied. Determining diet is difficult due to biases inherent in all standard diet analysis methods. Morphological gut-content analysis (M-GCA), DNA metabarcoding of gut contents (D-GCA), and stable isotope analysis (SIA) are currently three of the most frequently conducted diet analyses; and while combinations of these methods are commonly …

Effects Of 17Α-Ethinylestradiol (Ee2) On Gonadal Development And Gene Expression In Larval Mummichog (Fundulus Heteroclitus), Carly Sing-Judge

Theses and Dissertations (Comprehensive)

The mummichog (Fundulus heteroclitus) is a small-bodied estuarine fish that inhabits the North American east coast and is often used as a model adult saltwater fish in environmental bioassays. This study aimed to describe gonadal development and gene expression levels in five-week-old mummichog under control conditions and following 17α-ethinylestradiol (EE₂) treatment in order to better understand the susceptibility of sex determination (SD) and gonadal differentiation (GD) processes following contaminant exposure. In the first experiment, eggs were fertilized, collected and incubated in the laboratory for three weeks, then yolk-sac larvae were grown out for five weeks and …

Design And Validation Of Artificial Feeders To Study Feeding Preferences And Growth Of Hematophagous Juvenile Sea Lamprey (Petromyzon Marinus), Gracie Li-Ting-Wai

Theses and Dissertations (Comprehensive)

The parasitic and invasive land-locked sea lamprey Petromyzon marinus populations contributed to the collapse of the Great Lakes fisheries in the mid-1900s, while native anadromous populations are currently under threat and require conservation efforts for protection. Despite the increasing concern for both populations of this species, the juvenile stage of the sea lamprey’s life cycle has not been well studied. This is due, in part, to ethical concerns raised around holding live host fish with juveniles and the lack of an alternative feeding method to maintain these juveniles in the laboratory. The feeder should be designed to minimize fouling of …

Young Adult And Adolescent Balance Control Strategies During A Dual-Task Stone-Stepping Paradigm, Emily Ford

Theses and Dissertations (Comprehensive)

Stone-stepping demands greater attention and visuomotor integration, as it requires precise foot placement. The amount of attention required during locomotion is typically assessed with a secondary task, by analyzing the dual-task cost. Adolescents are suggested to have a greater dual-task cost than young adults and demonstrate balance control impairments while dual-tasking walking. The purpose of the current study was to explore the balance control differences between adolescents and young adults during a stone-stepping paradigm. We hypothesized that adolescents would experience greater balance control deficits while performing the secondary task compared to the young adults, especially while on the uneven terrain. …

The Avian Hippocampal Declarative Memory System, Chelsey C. Damphousse

Theses and Dissertations (Comprehensive)

Across Mammalia, memory has long been dissociated into multiple component systems specialized to process specific facets of experience. Among these segregated systems, declarative memory is processed by the hippocampus and surrounding structures, which have collectively been referred to as the hippocampal declarative memory system (HDMS). The HDMS, in turn, can be further divided into parallel streams dedicated to the processing of spatial versus object identity based information, commonly discussed as the ‘what’ and ‘where’ streams. While we know that the organization of the HDMS is conserved in humans, nonhuman primates, and rats, evidence outside Mammalia is lacking. Here HDMS homology …

Diversity And Evolution Of Inflorescences In Cuscuta, Morgan Glofcheskie

Theses and Dissertations (Comprehensive)

Cuscuta (dodder) includes ca. 200 species of plant obligate stem parasites with both ecological and economical significance. Inflorescences have been historically used in Cuscuta for species descriptions and identification keys, but no comprehensive study exists to date. The main objective of this study was to survey the diversity of inflorescences, and to understand their evolution and possible form-function relationships. The inflorescence architecture of 132 Cuscuta taxa was analyzed using herbarium specimens, and eight species were grown to study their inflorescence development. Inflorescence traits were mapped into a genus phylogeny obtained from a combined analysis of nuclear ITS and plastid trnL-F …

Toxicity Of The Technology Critical Elements Germanium And Yttrium To Daphnia Magna And Hyalella Azteca And The Influence Of Toxicity Modifying Factors, Rashid Shah

Theses and Dissertations (Comprehensive)

Technology critical elements (TCEs) are increasingly used in high and green technologies but there is little aquatic toxicity data for TCEs, particularly in fresh water. The objective of this study was to investigate the toxicity of two TCEs, Ge and Y, to Daphnia magna and Hyalella azteca and to understand the role of natural organic matter and cations on toxicity modification. Testing followed standard methods. The 48 h EC50 for D. magna was 11.6 (95% CI of 9.64-13.8) mg Ge/L based on measured dissolved concentrations at test end. The addition of NOM at 10 mg DOC/L resulted in a significant …

The Impact Of Combined Flexion And Compression On The Mechanical Integrity Of The Annulus Fibrosus, Keaton Briar

Theses and Dissertations (Comprehensive)

Introduction: Intervertebral disc (IVD) herniation is characterized by an expulsion of nucleus pulposus (NP) material through the annulus fibrosus (AF). The AF contains two major adhesive structures, the intralamellar matrix and the interlamellar matrix, which act to maintain the strength of the AF and prevent NP material migration. As a herniation occurs, clefts form within the intralamellar matrix, pushing the NP between adjacent collagen fibres; meanwhile, delamination of the interlamellar matrix causes the NP to pool between layers of the AF. Further, herniation more readily occurs in a combined loading scenario of both compression and flexion. Flexion, and in particular …

Exploring The Relationship Between Dog Ownership, Physical Activity, And Mental Health, Stephanie Ho, Jennifer Robertson-Wilson, Mark Eys

Theses and Dissertations (Comprehensive)

The physical and mental health benefits of regular physical activity have been well-documented (e.g., Reiner et al., 2013; White et al., 2017). Additionally, owning a dog is associated with positive health outcomes as owners are encouraged to walk. Dogs are also a source of comfort during stressful times for those in their presence (e.g., Brown & Rhodes, 2006; Westgarth et al., 2017). The aim of this study was to examine the relationship between dog ownership, physical activity, and mental health among the university student population. Over 500 university students completed questionnaires assessing their demographic information, mental health, dog ownership status, …