Life Sciences Commons^™

Quantatative Analysis Of Microbial Abundance Within Arctic Fjord Sediments Assessed Through Direct Counting, Alex Taylor Swystun

EURēCA: Exhibition of Undergraduate Research and Creative Achievement

Microbes found in the marine sediments are responsible for the production of nearly half of the carbon dioxide found in the atmosphere (Arrigo, 2005). The fjords of Svalbard (79°N) are not considered typical marine sediments because high iron content influences unique subsurface redox chemistry. Radiotracer studies have shown that these sediments contain active bacterial sulfate-reducing communities (Finke et al., 2016). In addition to bacteria, archaeal cells within these sediments have been in aggregates encompassed by sulfate-reducing bacteria (Ravenschlag et al., 2001). These anaerobic organisms participate in mediating environmental biogeochemical cycles, including the oxidation of methane (Ravenschlag et al., 2001) and …

Evidence For The Priming Effect In Single Strain And Simplified Communities Of Estuarine Bacteria, Abigail Amina Edwards

EURēCA: Exhibition of Undergraduate Research and Creative Achievement

Through their transformation of naturally occurring organic matter, coastal marine bacteria play an essential role in carbon cycling. A phenomenon termed the priming effect (PE) occurs when microbial communities remineralize recalcitrant organic matter faster in the presence of labile organic matter and may be prevalent in coastal systems. To understand how microbial community members interact to induce PE, it is essential to first understand the mechanisms underlying PE in single strains and simplified bacterial communities. The effect to which different concentrations and sources of labile carbon stimulated the production of bacterial biomass from riverine organic matter by two marine bacteria …

Clinical And Subclinical Mastitis Causing Pathogens In Tennessee Dairy Cattle, Michelle Marie Untch

EURēCA: Exhibition of Undergraduate Research and Creative Achievement

Milk quality impacts the producers and consumers. Higher milk quality leads to a longer shelf life, improved cheese making ability, and improved taste. Milk quality can be severely impacted by intramammary infections which can result in mastitis. Identifying the common mastitis causing pathogens in milk samples collected from subclinical and clinical mastitis cases can assist the producer in managing mastitis. This can lead to improved milk quality, improved cow health, and reduced need for antibiotics to treat mastitis. This study investigates the prevalence of bacteria causing intramammary infection in dairy cattle of Tennessee. Milk samples were collected from 9 farms …

Bioinformatic And Experimental Approaches For Deeper Metaproteomic Characterization Of Complex Environmental Samples, Ramsunder Mahadevan Iyer

Doctoral Dissertations

The coupling of high performance multi-dimensional liquid chromatography and tandem mass spectrometry for characterization of microbial proteins from complex environmental samples has paved the way for a new era in scientific discovery. The field of metaproteomics, which is the study of protein suite of all the organisms in a biological system, has taken a tremendous leap with the introduction of high-throughput proteomics. However, with corresponding increase in sample complexity, novel challenges have been raised with respect to efficient peptide separation via chromatography and bioinformatic analysis of the resulting high throughput data. In this dissertation, various aspects of metaproteomic characterization, including …

Investigating The Regulation Of Indole-3-Acetic Acid Production By The Plant Associated Microbe Pantoea Sp. Yr343, Kasey Noel Estenson

Doctoral Dissertations

The auxin indole-3-acetic acid (IAA) plays a central role in plant growth and development and many plant-associated microbes produce IAA. Several IAA biosynthetic pathways have been identified in microbes which use the precursor tryptophan. Pantoea sp. YR343, which was isolated from the Populus deltoides rhizosphere, is a robust plant root colonizer that produces IAA. Using genomic and metabolomics analyses, we predicted that the indole-3-pyruvate (IPA) pathway is the major pathway in Pantoea sp. YR343 for IAA production. To better understand IAA biosynthesis and the effects of IAA exposure on cell physiology, we performed proteomics on Pantoea sp. YR343 grown in …

Forest Resources For Bioenergy, Gerry Solano Avila

Doctoral Dissertations

The overall objective of this dissertation is to evaluate forest resources biomass availability for the production of bioenergy. Chapter II provides measures of the impact that the road sustainability criteria have on the supply of feedstock for forest products and bioenergy. A linear cost minimization programming is used in estimating forest biomass supply curves. Chapter III provides estimates on the changes in US timberland acreages overtime and the ability of timberland to meet conventional timber products and woody biomass demand within the conterminous United States. Chapter IV utilizes the Biofuels Facility Location Analysis Modeling Endeavor (BioFLAME), a Geographic Information System …

Non-Canonical Signaling From The Etr1 And Etr2 Ethylene Receptors In Arabidopsis Thaliana, Arkadipta Bakshi

Doctoral Dissertations

The gaseous phytohormone ethylene regulates several physiological and developmental processes in higher plants. There are five ethylene receptor isoforms that mediate the responses to ethylene in the model plant Arabidopsis thaliana. Prior research has shown that these five ethylene receptor isoforms in Arabidopsis have both overlapping and non-overlapping roles in regulating diverse responses such as growth in air, growth recovery after removal of ethylene, and ethylene stimulated nutational bending. Functional divergence of ETR1 has been determined in controlling some of these traits and in some of these cases, ETR1 subfunctionalization requires the receiver domain. Using homology modeling and sequence …

Morphological And Gene Expression Plasticity In Neotropical Cichlid Fishes, Sharon Fern Clemmensen

Doctoral Dissertations

Trophic divergence in cichlid fish is linked to morphological shifts in the pharyngeal jaw apparatus. For instance, in the Heroine cichlids of Central America, the ability to crush hard-shelled mollusks is a convergent phenotype with multiple evolutionary origins. These durophagous species often have very similar pharyngeal jaw morphologies associated with the pharyngeal jaw apparatus and some of these similarities could be due to phenotypically plastic responses to mechanical stress. I examined the durophagous cichlid Vieja maculicauda for differences in pharyngeal osteology, dentition, and soft tissues when exposed to different diet regimes. Here I discuss the effect on the morphology and …

Design And Synthesis Of Analogs Of Myo-Inositol, Serine, And Cysteine To Enable Chemical Biology Studies, Tanei J. Ricks

Doctoral Dissertations

Phosphorylated myo-inositol compounds including inositol phosphates (InsPs) as well as the phosphatidylinositol polyphosphate lipids (PIP_ns) are critical biomolecules that regulate many of the most important biological processes and pathways. They are aberrant in many disease states due to their regulatory function. The same is true of the phospholipid phosphatidylserine (PS) which can serve as a marker to begin apoptosis. However, the full scope of activities of these structures is not clear, particularly since techniques that enable global detection and analysis of the production of these compounds spatially and temporally are lacking. With all of these obstacles in …

Systematics And Biogeography Of The Cortinarius Violaceus Group And Sequestrate Evolution In Cortinarius (Agaricales), Emma Harrower

Doctoral Dissertations

Phylogenetics is a powerful tool used for illuminating the diversity of life on Earth, their evolution and their ecology. I created a multi-gene phylogenetic tree of Cortinarius section Cortinarius and uncovered five previously overlooked species, increasing the number of species in the section from seven to twelve. All members of the clade possess both cheilocystidia and pleurocystidia and possess a pigment known as (R)-39,49-dihydroxybphenylalanine. Ancestral state reconstruction estimated that the ancestral host was most likely an angiosperm, switching hosts when encountering novel host species in new lands, and only C. violaceus associating with the Pinaceae in North America. Biogeographic analysis …

Mediation And Moderation Of Intergenerational Epigenetic Effects Of Trauma, Stefanie Renee Pilkay

Doctoral Dissertations

Trauma and early-life stress have been linked to poor mental and physical health outcomes. In fact, research has identified trauma and stress can influence epigenetic marks on genes that can alter gene activity. It is suspected that epigenetically altered gene activity is involved in behavior and mental health. This may help explain why some individuals don’t experience great benefit from treatment for the effects of stress, and severe mental health symptoms can be chronic for decades or a lifetime. Moreover, some trauma-related mental health symptoms have shown generational patterns that appear linked to epigenetic marks. Therefore, this study sought to …

Hybrid Recombineering: Crispr/Cas9 Mutagenesis Of Murine Cytomegalovirus Bac, Cody Sain

Haslam Scholars Projects

Human cytomegalovirus (HCMV) is a ubiquitous herpesvirus that can asymptomatically infect immunocompetent hosts with little-to-no impact. Conversely, HCMV can trigger life-threatening disease in immunocompromised hosts such as neonates, organ transplant recipients, and people living with AIDS. HCMV is a unique pathogen in that it can hijack the immune system for its benefit and disseminates throughout the body using host immune cells. Previous studies suggest that innate immune cells are responsible for viral dissemination. However, adequate methods for investigating the spread of CMV within a murine model remain incomplete. We implicate the innate immune cell the neutrophil as a major cell …

Stressing Out: Dynamics Of Chromatin Insulator Body Formation In Eukaryotes Under Osmotic Stress, Shannon Marie Garland

Masters Theses

Higher order genome organization and the role it plays in governing cell dynamics and protein expression has become a widely studied field. Chromatin insulators are important to this organization in their ability to form long range contacts between distant regions on the genome. During times of osmotic stress, insulator proteins leave their binding sites on the DNA to form insulator bodies in the nucleus. This phenomenon relieves the DNA of its structure and is rapidly reversible. Using a variety of immunofluorescent staining methods, this work looked to further characterize this process while attempting to identify molecular mechanisms that mediate chromatin …

Coping With Drought In Beef Cattle Production: Innovation Through Optimal Warm-Season Forage Systems, Katelynn Elizabeth Zechiel

Masters Theses

Drought conditions have had detrimental effects on beef cattle production in the southeastern states where forages are the primary source of feed for livestock. Many southeastern states lie within the fescue-belt, where tall fescue is the predominant livestock forage. Tall fescue is a cool-season (CS) grass that thrives in the cooler temperatures of spring and fall, becoming semi-dormant during peak summer temperatures and again in winter. Conversely, warm-season (WS) forage species increase in production during the summer months and exhibit drought tolerant qualities, making them a viable summer forage option to complement tall fescue for beef cattle producers. The primary …

Aspects Of The Physiological And Behavioral Defense Adaptations Of The Mountain Madtom (Noturus Eleutherus), Meredith Leigh Hayes

Masters Theses

Madtoms (Noturus spp.) are a highly endemic clade of miniature catfishes that faces widespread imperilment. Little is known about the ecology of these secretive fishes, and understanding the behavioral and physiological adaptations madtoms have evolved to resist pathogens and competitors is necessary for conservation.

Madtoms nest under cover and provide extensive paternal care. Attempts to rear eggs in captivity result in high mortality rates from infection, leading to questions about how wild nests resist disease. In many fishes, males produce antimicrobial substances that confer protection to eggs. To determine if guardian males deter disease in nests, Mountain Madtoms ( …

Surveillance Of Ticks Parasitizing Tennessee Beef Cattle And Investigations Into The Microbial Communities Of Cattle Associated And Questing Amblyomma Maculatum, David Paul Theuret

Masters Theses

Despite the risks that ticks and tick-borne disease pose to the beef cattle industry, many Tennessee producers are unaware of the dangers they represent. This mindset could facilitate the invasion and establishment of exotic ticks and pathogens that would devastate the cattle industry. Current control practices rely on chemical methods, which are not effective long-term; therefore, investigations into creating an integrated approach to control would create more sustainable methods. This study aims to address this through two objectives: The first is to determine the species composition, seasonal prevalence, geographic distribution and diversity of ticks on Tennessee cattle. The second is …

Reproduction And Bioconfinement Of Mir156 Transgenic Switchgrass (Panicum Virgatum L.), Chelsea Renai Johnson

Masters Theses

Genetic engineering of switchgrass (Panicum virgatum L.), an emerging cellulosic bioenergy feedstock, has been performed to alter cell walls for improved biofuel conversion. However, gene flow from transgenic switchgrass presents regulatory issues that may prevent commercialization of the genetically engineered crop in the eastern United States. Depending on its expression level, microRNA156 (miR156) can reduce, delay or eliminate flowering, which may be useful to mitigate transgene flow. However, flowering transition is dependent upon both environmental and genetic cues. In this study of transgenic switchgrass, two low (T14 and T35) and two medium (T27 and T37) miR156 overexpressing ‘Alamo’ lines …

Bat Population Status And Roost Selection Of Tri-Colored Bats In The Great Smoky Mountains National Park In The Era Of White-Nose Syndrome, Grace Marie Carpenter

Masters Theses

The ongoing spread of white-nose syndrome is causing devastating declines range-wide for certain North American bat species. Baseline population data that would help mangers monitor bat populations in the face of WNS is lacking. Likewise, knowledge of summer roosts, a limiting resource for tri-colored bats (Perimyotis subflavus), a species threatened by WNS, is lacking in the southern portion of their range. In our study, we investigated the effect that WNS has had on a population of tricolored bats in the Great Smoky Mountains National Park, TN-NC. We also characterized summer roosts for the species at the microhabitat and …

Molecular Classification And Uv Tolerance Of Pigmented Antarctic Extremophiles, Aaron M. Perry

Chancellor’s Honors Program Projects

No abstract provided.

Tea Induction Of Cyp6a8 Promoter In Drosophila Melanogaster, Fiona Retzer

Chancellor’s Honors Program Projects

No abstract provided.

Histomonas Elisa, Jessica L Martinez

EURēCA: Exhibition of Undergraduate Research and Creative Achievement

Histomonas meleagridis is a protozoan parasite of avians and is the causative agent in Histomonosis, commonly known as Blackhead Disease. Current methods for diagnosing the presence of H. meleagridis are limited to parasite culture or Polymerase Chain Reaction (PCR) to amplify target DNA. This project aims to develop an enzyme-linked immunosorbent assay (ELISA) for faster and more sensitive diagnosis of Histomonas infections. Cultures of H. meleagridis parasites were purified, and surface antigens were extracted using a spectrum of chemical solutions. The various antigen solutions were subjected to an ELISA, with serum from birds immunized for H. meleagridis as positive controls. …

Vegetation And Arthropod Responses To Brush Reduction By Grubbing And Stacking, Carter Crouch, J. Alfonso Ortega-Santos, David B. Wester, Fidel Hernández, Leonard A. Brennan, Greta L. Schuster

National Quail Symposium Proceedings

Grubbing is a mechanical brush-reduction technique that allows targeting of mesquite (Prosopis glandulosa) and huisache (Vachellia farnesiana) and can be used to open lanes for hunting northern bobwhites (Colinus virginianus). Follow-up treatments of stacking allow the piling up of downed brush. We initiated this study on the Santa Gertrudis Division of the King Ranch, Inc., Texas, to determine effects of grubbing and stacking on vegetation and arthropod communities important to bobwhite. We hypothesized that grubbing and stacking would be able to selectively remove mesquite and huisache while leaving mixed brush species largely intact. We …

Social Status Modulates Restraint- Induced Neural Activity In Brain Regions Controlling Stress Vulnerability , Sahba Seddighi, Matthew A. Cooper

Haslam Scholars Projects

Understanding the cellular mechanisms that control resistance and vulnerability to stress is an important step toward identifying novel targets for the prevention and treatment of stress-related mental illness. Dominant and subordinate animals have been shown to exhibit different behavioral and physiological responses to stress, with dominants often showing stress resistance and subordinates often showing stress vulnerability. We have previously found that dominant hamsters exhibit reduced social avoidance following social defeat stress compared to subordinate hamsters, although the extent to which stress resistance in dominants generalizes to non-social stressors is unknown. In this study, dominant, subordinate, and control male Syrian hamsters …

Physiological Ecology Of Four Endemic Alabama Species And The Exotic Asiatic Weatherfish, Misgurnus Anguillicaudatus (Cantor, 1842), Lindsay M. White, Mark E. Meade, Benjamin A. Staton

Southeastern Fishes Council Proceedings

The occurrence of Asiatic Weatherfish, Misgurnus anguillicaudatus, in Alabama, a state known for its rich biodiversity, has generated concern among conservation managers. The current study used respirometry techniques to investigate the effects of increasing temperature on four native southeastern fishes (one cyprinid, two percids, and one elassomid) and the non-native M. anguillicaudatus. A minimum of five individuals of each species were used, and three experimental temperatures were chosen to represent spring and summer averages of northeast Alabama streams (15, 20, and 25°C). Overall, mean standard metabolic rates (SMRs) for M. anguillicaudatus were low (97.01, 127.75, and 158.50 mg …

First Report Of A Population Of Western Blacknose Dace (Rhinichthys Obtusus) In The Brushy Creek System Of The Black Warrior River Drainage, Alabama, Eric Bauer, Malorie M. Hayes

Southeastern Fishes Council Proceedings

Alabama is home to the southernmost populations of Rhinichthys obtusus, the Western Blacknose Dace. Within Alabama, R. obtusus is found in the Tennessee, Coosa, and Black Warrior River basins, but its presence in the Black Warrior River drainage has been limited. Until now, R. obtusus in the Black Warrior drainage has only been reported as collections of 1 to 4 specimens at a time in the Sipsey Fork drainage. Herein, we report two novel occurrences of R. obtusus in the headwaters of the Brushy Creek system in the Black Warrior River drainage including a singleton and a large population. …

Life-History Aspects Of Chrosomus Oreas (Mountain Redbelly Dace) In Catawba Creek, Virginia, Dezarai Thompson, Shelby Hargrave, Gregory Morgan, Steven L. Powers

Southeastern Fishes Council Proceedings

Life-history aspects of Chrosomus oreas, Mountain Redbelly Dace, were identified using specimens collected monthly from Catawba Creek in Roanoke County, Virginia. Chrosomus oreas were found in depths up to 63.3 cm with a modest relationship between abundance and depth. The largest specimen examined was a female 64.68 mm standard length, 4.80 g eviscerated weight, and 36 months of age. The oldest specimens examined were 37 months of age suggesting a maximum lifespan of approximately three years. Spawning appears to occur from April to early July, with a mean of 243 oocytes (SD = 178) up to 1.61 mm diameter …

Development Of Ms-Based Proteomics Approaches To Examine Metabolic Pathways And Protein:Protein Interactions In Microbial Systems, Chen Qian

Doctoral Dissertations

The proteome is perhaps the most functional operating machinery for almost all biological processes, serving as the bridge to link the genome and phenotypes. The proteome undergoes dynamic changes in terms of the abundance or interactions, responding to the environmental stimuli. Understanding this dynamic of protein alterations is the key to delineate critical biological mechanisms. Mass-spectrometry-based proteomics is a powerful tool to systematically monitor the heterogeneous alterations of the proteome, including the changes of abundance, modifications and interactions. In this dissertation, a research project was built upon current proteomics approaches to solve the issues regarding to the sample preparation and …

Assessment Of Genetic And Education Recovery Plan Objectives For The Bog Turtle (Glyptemys Muhlenbergii), Cassie Marie Dresser

Doctoral Dissertations

Unprecedented declines in biodiversity are threatening the natural world as we know it. Without human intervention, two thousand species listed under the US Endangered Species Act are likely to disappear. Fortunately, these species receive federal protection and increased research effort is needed to create and satisfy the objectives outlined in the mandated Species Recovery Plan. In this dissertation, I address three conservation objectives outlined in the Recovery Plan for North America’s smallest and rarest turtle, the Bog Turtle (Glyptemys muhlenbergii): (1) investigate the potential genetic differentiation in southern portions of the species’ range, (2) investigate the genetic impacts …

A Transcriptomic Analysis Of Salmonella Enterica Newport In Planta And After Postharvest Sanitization, Laurel Lynn Dunn

Doctoral Dissertations

The consumption of fresh produce is increasingly linked to incidence of foodborne illness. Pathogens including Salmonella enterica, Shiga toxigenic Escherichia coli, and Listeria monocytogenes are exposed to produce crops through direct human or animal contact, contaminated agricultural water, bioaerosols, run-off, and improperly treated compost. S. enterica has demonstrated exceptional tolerance to the stresses encountered in the environment, on plant tissue, and from postharvest antimicrobial mitigation strategies. Understanding the transcriptomic mechanisms S. enterica employs to survive these hazards is integral for the development of more effective preventive controls and post-harvest steps to prevent the pathogen from infecting consumers.

Effect Modification Of The Association Between Aerobic Physical Activity And Diabetes-Related Mortality By Race-Ethnicity: A Population-Based Prospective Study Using Nhanes Iii And 1999-2006 Nhanes, William Robert Boyer Ii

Doctoral Dissertations

Purpose: To examine potential effect modification by race-ethnicity of the relationship between physical activity (PA) and diabetes-related mortality risk using a sample of U.S. adults from the Third National Health and Nutrition Examination Survey (NHANES III). Methods: The sample (n=10,717) included adults (≥20 years) who attended the Mobile Examination Center (MEC). An age-standardized PA score (PAS) was calculated from the self-reported frequency and intensity of 12 leisure-time aerobic activities. The PA scores were then grouped into three categories: inactive (PAS = 0), insufficiently active (PAS >0 - Results: There was no interaction between PA and race-ethnicity (p=0.83). Compared to inactive …