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The Algz/R Two-Component System Is Responsible For Attenuation Of Virulence In Pseudomonas Aeruginosa, Danielle A. Williams Dec 2017

The Algz/R Two-Component System Is Responsible For Attenuation Of Virulence In Pseudomonas Aeruginosa, Danielle A. Williams

Electronic Theses and Dissertations

Pseudomonas aeruginosa is an important opportunistic pathogen. Many P. aeruginosa virulence factors are regulated by the AlgZ/R two component system. AlgZ is the sensor histidine kinase which phosphorylates AlgR, the response regulator. AlgR activates transcription of different gene targets based upon its phosphorylation state. The genes that encode AlgZ and AlgR are transcribed in an operon. While regulation of algR expression has been well studied, regulation of algZ expression has not. Using a pilW mutant in concert with algZTF-lacZ transcriptional fusion, we conducted a transposon mutagenesis to identify algZ regulators. We identified an unknown autoregulatory loop. The type …


Examining The Understanding Of Inquiry-Based Learning And Teaching Among Undergraduate Teachers And Students, Maren Hudson Dec 2017

Examining The Understanding Of Inquiry-Based Learning And Teaching Among Undergraduate Teachers And Students, Maren Hudson

Electronic Theses and Dissertations

One of the main aims of inquiry is to engage students as active, not passive, participants in science. The purpose of this study is to describe science educators’ and students’ views about inquiry-based instruction in order to better understand and improve implementation of evidence-based teaching strategies. Inquiry-based techniques have been shown to improve student understanding of scientific concepts, yet, there continue to be challenges in implementing these techniques. This research project utilizes Q Methodology, a research method that captures both common and disparate measures of subjectivity, to identify commonalities and defining viewpoints about inquiry-based teaching and learning. Three significantly different …


A Study Of Salmonid Growth In Two Southern Appalachian Headwater Streams, Joshua Argo Aug 2017

A Study Of Salmonid Growth In Two Southern Appalachian Headwater Streams, Joshua Argo

Electronic Theses and Dissertations

This study sampled salmonid populations in two headwater streams in East Tennessee, Briar Creek and Left Prong Hampton Creek. Length and weight data were used to calculate the growth of these populations to determine if significant variation exists between isolated brook trout populations. Slope comparisons concluded that there was a difference in growth between brook trout populations of these streams (p


Effects Of Acute Sepsis On Renal Structure And Sympathetic Innervation In Mice, Tuqa Alkhateeb Aug 2017

Effects Of Acute Sepsis On Renal Structure And Sympathetic Innervation In Mice, Tuqa Alkhateeb

Electronic Theses and Dissertations

Sympathetic nerves are important for renal physiology and sepsis pathophysiology. A recent study showed sprouting of sympathetic nerves in spleen of septic mice. This study was done to test if renal sprouting of sympathetic nerves also happens and to investigate renal morphology in septic mice. Cecal ligation and puncture (CLP) was used to induce sepsis and kidneys were removed for evaluation. Bowman’s space was diminished with cortical bubble cells present suggestive of acute renal pathology, however, renal function was unchanged. Acute sepsis did not affect either renal sympathetic innervation or non-neuronal cholinergic cells. Mouse kidneys had more epinephrine (EPI) than …


Enemy Exacerbation: Effects Of Predator Stress On Sulfate Lethality In Freshwater Amphipods (Gammarus Minus), Trevor Chapman Aug 2017

Enemy Exacerbation: Effects Of Predator Stress On Sulfate Lethality In Freshwater Amphipods (Gammarus Minus), Trevor Chapman

Electronic Theses and Dissertations

Predator cues can influence how aquatic organisms respond to anthropogenic contaminants. This study examined the effects of predator cues on behavior, metabolic rate, and sulfate (as Na2SO4) toxicity in amphipods (Gammarus minus). Predator cues included alarm cue (macerated conspecifics) and kairomone from mosquitofish (Gambusia affinis). Amphipods decreased activity and increased time in refuge when exposed to alarm cue, and increased time in refuge when exposed to kairomone. While median lethal concentrations (96-h LC50) were not influenced by predator cues, analysis of dose response curves indicated that kairomone exposure increased amphipod …


Effects Of Predatory Cues On Copper Sensitivity And Metabolic Rate In Gambusia Affinis, Melissa N. Campbell May 2017

Effects Of Predatory Cues On Copper Sensitivity And Metabolic Rate In Gambusia Affinis, Melissa N. Campbell

Electronic Theses and Dissertations

Organisms living in aquatic environments are subject to a number of stressors from natural (temperature, predation, food availability) and anthropogenic origins (pesticides, metals, etc). Natural stressors may amplify the effects of contaminants and increase an organism’s sensitivity to them. Understanding the impact of these combined factors is therefore essential for the practical management of contaminants. This study sought to examine how predatory cues affect copper tolerance in the mosquitofish, Gambusia affinis. The influence of predatory cues on fish metabolic rate was also evaluated to gain insight on any interactive effects between the natural stressor and copper. Alarm cues, chemicals released …


Elucidating The Effects Of Thiamethoxam Neonicotinoid On Honey Bee Learning Using The Proboscis Extension Response, David J. Shepherd May 2017

Elucidating The Effects Of Thiamethoxam Neonicotinoid On Honey Bee Learning Using The Proboscis Extension Response, David J. Shepherd

Undergraduate Honors Theses

In this study, the effects of the neonicotinoid pesticide, thiamethoxam, are examined through the Proboscis Extension Response (PER) in honey bees (Apis mellifera). PER is a form of classical conditioning applied to honey bees through scent and reward association which quantifies learning rates. Results between groups treated with thiamethoxam did not differ significantly from untreated control groups. Potential reasons for these results are discussed. The method and experimental apparatus for testing the PER assay are also discussed.


Toll Like Receptor 4 Stimulation Increases Scavenger Receptor A Expression On Murine Macrophages, Mackenzie L. Guthrie May 2017

Toll Like Receptor 4 Stimulation Increases Scavenger Receptor A Expression On Murine Macrophages, Mackenzie L. Guthrie

Undergraduate Honors Theses

Sepsis is the body’s response to an overwhelming infection and is a serious consequence of critical illness. It can cause tissue damage, organ failure, and death. Sepsis continues to have an unacceptably high mortality rate, due to the lack of effective treatments. Specific therapeutic targets for sepsis remain elusive since the complex functional changes that result in a septic state remain poorly understood. Macrophage Scavenger Receptor A (SRA, CD204) is a surface receptor that binds negatively charged, endogenous and exogenous ligands. We have discovered that SRA plays a significant role in the pathophysiology of sepsis. We have shown that mice …


Range-Wide Prevalence And Impacts Of Pseudocercosporella Inconspicua On Lilium Grayi And An Assessment Of L. Superbum And L. Michauxii As Reservoirs, Cindy L. Barrett May 2017

Range-Wide Prevalence And Impacts Of Pseudocercosporella Inconspicua On Lilium Grayi And An Assessment Of L. Superbum And L. Michauxii As Reservoirs, Cindy L. Barrett

Electronic Theses and Dissertations

Lilium grayi (Gray’s Lily), a southern Appalachian endemic species, is threatened by a Lilium-specific fungal pathogen, Pseudocercosporella inconspicua. The disease is characterized by tan lesions that can cause early senescence, while also lowering seed production and viability. This project tested for P. inconspicua conidia and accessed health at nine locations. The disease was present and ubiquitous across the range of L. grayi. Through identification of P. inconspicua conidia in the field, L. superbum (Turk’s Cap Lily) was identified as an additional host, while L. michauxii (Michaux’s Lily) was disease-free. However, infection was inducible in both species. With …


Inclusive Teaching Strategies: An Evaluation Of Course Structure And Summative Assessment In Introductory Biology, Oluwaseun O. Agboola May 2017

Inclusive Teaching Strategies: An Evaluation Of Course Structure And Summative Assessment In Introductory Biology, Oluwaseun O. Agboola

Electronic Theses and Dissertations

Several active learning strategies have been used when increasing the structure of a course as increasing course structure has been known to improve student learning in introductory STEM courses. Much has been studied on the value of frequent formative assessment; however, few studies have evaluated the effective modes of delivering summative assessment. This study examines the use of summative assessment as an inclusive teaching practice to improve first generation college student success in introductory biology and also uses faculty surveys to find out how instructors structure their introductory biology course and why they are structured that way. Final exams were …