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Theses and Dissertations (Comprehensive)

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Full-Text Articles in Integrative Biology

Do Toxicity Modifying Factors Influence Acute Or Chronic Toxicity Of Thulium To Hyalella Azteca?, Alexandria H. Loveridge Jan 2016

Do Toxicity Modifying Factors Influence Acute Or Chronic Toxicity Of Thulium To Hyalella Azteca?, Alexandria H. Loveridge

Theses and Dissertations (Comprehensive)

The industrial demand for rare earth elements (REEs) is growing and as a result, environmental exposure is a concern. Very little is understood about the toxicity of REEs in aquatic environments. The objective of this research is to evaluate the acute and chronic toxicity of Tm and to also understand the toxicity modifying influence of dissolved organic matter (DOM) and cationic competition (Ca2+, Mg2+ and Na+). Furthermore, the aim of this study was to determine linkages between Tm bioaccumulation, growth and survival during chronic exposures. Standard methods (Environment Canada) were followed for both 96h acute and 14d chronic tests, in …

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Metabolic Scaling Physiology And The Uptake, Elimination And Toxicity Of Tfm (3-Trifluoromethyl-4-Nitrophenol) To Invasive Sea Lampreys (Petromyzon Marinus), Laura R. Tessier Jan 2016

Metabolic Scaling Physiology And The Uptake, Elimination And Toxicity Of Tfm (3-Trifluoromethyl-4-Nitrophenol) To Invasive Sea Lampreys (Petromyzon Marinus), Laura R. Tessier

Theses and Dissertations (Comprehensive)

Sea lampreys (Petromyzon marinus) have a complex life cycle that involves a parasitic phase in which they feed on the blood and bodily fluids of large piscivorous fishes. Following the invasion of the Great Lakes by sea lampreys in the early 20th century, sea lamprey parasitism contributed to major declines in the populations of commercial and sports fisheries in that basin. The lampricide 3-trifluoromethyl-4-nitrophenol (TFM), developed in the late 1950s,is now routinely applied to tributaries of the Great Lakes to control sea lamprey populations. This lampricide is selectively toxic to larval sea lampreys, which typically reside as …

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Understanding The Physiological Effects Of Suspended Material On Rainbow Trout (Oncorhynchus Mykiss), Tyler J. Weinhardt Jan 2015

Understanding The Physiological Effects Of Suspended Material On Rainbow Trout (Oncorhynchus Mykiss), Tyler J. Weinhardt

Theses and Dissertations (Comprehensive)

The effect of global warming on northern environments is becoming increasingly evident. Melting of underlying permafrost is associated with widespread impacts in these environments. The loss of permafrost results in a destabilizing of underlying sedimentary layers resulting in thermokarst slumping. When this occurs on a large scale (mega-slumping) soil material becomes mobilized and is carried into local streams and rivers. The purpose of this study is to examine the sub-lethal physiological effects that suspended material has on rainbow trout (Oncorhynchus mykiss) in the context of the Peel River Plateau. Juvenile rainbow trout were exposed (following Environment Canada exposure …

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The Effects Of Lampricide 3-Trifluoromethyl-4-Nitrophenol Toxicity On The Gills Of Larval Sea Lamprey And Non-Target Rainbow Trout And Lake Sturgeon, Lisa A. Sorensen Jan 2015

The Effects Of Lampricide 3-Trifluoromethyl-4-Nitrophenol Toxicity On The Gills Of Larval Sea Lamprey And Non-Target Rainbow Trout And Lake Sturgeon, Lisa A. Sorensen

Theses and Dissertations (Comprehensive)

The pesticide, 3-trifluoromethyl-4-nitrophenol (TFM), is widely used in the Great Lakes to control invasive sea lampreys (Petromyzon marinus) populations, but much about its sub-lethal effects remains unknown. A better understanding of its toxicity is needed to improve TFM effectiveness and to protect non-target organisms from its potential adverse effects. The objectives of this thesis were to test the following two hypotheses: (1) impairment of mitochondrial ATP production by TFM interferes with ATP-dependent ion-uptake by fish, leading to altered electrolyte balance, and (2) perturbations of gill function by TFM are exacerbated in soft, ion poor water (SW; 40 mg …

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Purification And Characterization Of Bcsc; An Integral Component Of Bacterial Cellulose Export, Emily D. Wilson Ms Jan 2015

Purification And Characterization Of Bcsc; An Integral Component Of Bacterial Cellulose Export, Emily D. Wilson Ms

Theses and Dissertations (Comprehensive)

Biofilms are a growing concern in the medical field due to their increased resistance to antibiotics. When found in a biofilm, bacteria can have antibiotic resistance 10-1000 times that of their planktonic counterparts. Therefore, it is important to study the formation of biofilms. Cellulose biofilms are formed by Enterobacteriaceae, such as many Escherichia coli and Salmonella spp. strains. Biofilms provide these species with benefits including antimicrobial protection, development of bacterial communities, promotion of DNA exchange, uptake of nutrients, and, in the case of cellulose biofilms, immune system evasion. Cellulose biofilms are controlled by the Bacterial cellulose synthesis (Bcs) complex located …

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Impact Of Biofilm Formation And Composition On Antibiotic Resistance In Environmental Isolates Of Escherichia Coli And Salmonella Spp., Raluca Tutulan Jan 2015

Impact Of Biofilm Formation And Composition On Antibiotic Resistance In Environmental Isolates Of Escherichia Coli And Salmonella Spp., Raluca Tutulan

Theses and Dissertations (Comprehensive)

Escherichia coli and Salmonella spp., like most bacteria, prefer to grow in biofilms. These biofilms provide bacteria with protection from harsh environmental factors (such as desiccation and changes in pH), aid in the evasion of host immune responses and provide increased antibiotic resistance. Biofilms are present in non-host environments (e.g. water pipes) as well as in mammalian hosts (in the healthy gastrointestinal microbiota and in over 65% of nosocomial infections). Two important components utilized by E. coli and Salmonella spp. to form biofilms are cellulose and curli fimbriae. Curli fimbriae mediate the attachment of bacteria to abiotic surfaces and …

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Developing A Site Specific Understanding Of The Toxicity Of Rare Earth Elements, Cerium And Dysprosium, To Daphnia Pulex And Hyalella Azteca, Oliver Vukov Jan 2015

Developing A Site Specific Understanding Of The Toxicity Of Rare Earth Elements, Cerium And Dysprosium, To Daphnia Pulex And Hyalella Azteca, Oliver Vukov

Theses and Dissertations (Comprehensive)

Rare earth elements (REEs) are a group of similarly reactive metals that are divided into two groups; the light (LREEs) and heavy (HREEs) rare earths. These metals are used in a variety of industries and are critical to the function of modern society. The demand for REEs is expected to increase and as a result new mining projects are being developed with a potential for future mining in Canada. The toxicological understanding of these metals in the aquatic environment is very limited. The objective of this research is to compare the toxicological effect of REEs to the freshwater invertebrates Daphnia …

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Comparative Study Of Factors Influencing Seed Germination And Seedling Longevity In Cuscuta (Dodder, Convolvulaceae), Behrang Behdarvandi Jan 2014

Comparative Study Of Factors Influencing Seed Germination And Seedling Longevity In Cuscuta (Dodder, Convolvulaceae), Behrang Behdarvandi

Theses and Dissertations (Comprehensive)

Cuscuta (dodder), the only parasitic genus of Convolvulaceae family, is a significant plant from ecological, economical, and conservational point of views. The genus consists of c. 200 described species with wide ranges of ecological distributions. Cuscuta spp. are categorized as stem parasitic plants with reduced (or lost) photosynthesis-related genes. The filamentous coiled embryo, embedded in the endosperm, lacks cotyledons and is covered with a multiple-layered seed coat. The seedlings carry a vestigial root-like organ which is not considered a ‘true’ functional root. Members of the genus differ in their germination rate and seedling survival. It is known that seed …

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Microbial Community Characterization And Pathogen Profiling Of Land-Based Aquaculture Systems Using Culture-Based And Molecular-Based Fingerprinting Techniques, Nicole S. Kteily Jan 2014

Microbial Community Characterization And Pathogen Profiling Of Land-Based Aquaculture Systems Using Culture-Based And Molecular-Based Fingerprinting Techniques, Nicole S. Kteily

Theses and Dissertations (Comprehensive)

The growing worldwide demand for fish production has prompted research towards intensive aquaculture. Innovative system designs, such as recirculating and flow-through aquaculture systems, have been developed to improve the efficiency and sustainability of intensive aquaculture practices. These LBAS systems exhibit a wide range of spatial and temporal heterogeneity. Although such heterogeneity suggests the potential for culture water to support a diverse and spatially complex assortment of microorganisms, there is a lack of information regarding the overall diversity and composition of microbial communities (including pathogens) in the different compartments of these systems. To better understand the diversity and functionality of microbial …

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Comparative Analysis Of Selected Model Species Used In Intervertebral Disc Research, Lauren A. Monaco Jan 2014

Comparative Analysis Of Selected Model Species Used In Intervertebral Disc Research, Lauren A. Monaco

Theses and Dissertations (Comprehensive)

Animal models are frequently used in place of human specimens to study the progression of injury and/or disease of the intervertebral disc (IVD). This project aimed to compare the geometry, hydration, histology, and mechanical properties of selected animal models: bovine (cow) tail, porcine (pig) lumbar, and ovine (sheep) lumbar IVDs. X-ray images were taken and used to determine the anterior, posterior, and lateral IVD and vertebral heights in order to calculate IVD: vertebral height ratios. Water content was determined by comparing IVD weight before (wet weight) and after (dry weight) 24 hours of incubation at 65°C. Mechanical properties …

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Genome Jigsaw: Implications Of 16s Ribosomal Rna Gene Fragment Position For Bacterial Species Identification, Jennifer Mitchell Jan 2014

Genome Jigsaw: Implications Of 16s Ribosomal Rna Gene Fragment Position For Bacterial Species Identification, Jennifer Mitchell

Theses and Dissertations (Comprehensive)

The 16S rRNA gene is present within all bacteria, and contains nine variable regions interspersed within conserved regions of the gene. While conserved regions remain mostly constant over time, variable regions can be used for taxonomic identification purposes. Current methodologies for characterizing microbial communities, such as those used to study the human microbiome, involve sequencing short fragments of this ubiquitous gene, and comparing these fragments to reference sequences in databases to identify the microbes present. Traditionally, whole 16S rRNA sequences with more than 97% sequence identity (id) are assigned to a single operational taxonomic unit (OTUs); each OTU being a …

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Diversity And Evolution Of The Multicellular Protuberances In Cuscuta (Convolvulaceae) And The Function Of The Stomatiferous Protuberances In Cuscuta Subgenus Grammica, Courtney J. Clayson Jan 2014

Diversity And Evolution Of The Multicellular Protuberances In Cuscuta (Convolvulaceae) And The Function Of The Stomatiferous Protuberances In Cuscuta Subgenus Grammica, Courtney J. Clayson

Theses and Dissertations (Comprehensive)

Cuscuta (Convolvulaceae), also known as the dodders, is a holoparasitic genus comprised of ca. 200 species grouped into four subgenera: Monogynella, Cuscuta, Pachystigma, and Grammica. The presence of unique multicellular structures, referred to as stomatiferous protuberances (SPs), was reported on the stems of subgenus Grammica over a century ago and was forgotten until similar SPs were observed on the flowers of several new Grammica species. The stems and flowers were examined in 136 Cuscuta taxa, and SPs were discovered on all of the haustorial stems of the species in the subgenus Grammica, as well as …

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