Life Sciences Commons^™

Divergent Responses Of Cryptic Invasive Watermilfoil To Treatment With Auxinic Herbicides In A Large Michigan Lake, Syndell R. Parks

Masters Theses

Invasive plants are a major concern for environmental managers. Cryptic invasive taxa present additional challenges because of their potential to respond differently to management efforts. Invasive Eurasian watermilfoil (Myriophyllum spicatum) and hybrid watermilfoil (Myriophyllum spicatum x Myriophyllum sibiricum) cannot be reliably distinguished based on morphological characters and are therefore cryptic taxa. Laboratory studies show that on average, hybrid watermilfoil grows faster, branches more, and is less responsive to standard control measures developed for Eurasian watermilfoil. These laboratory results predict less effective control of hybrid watermilfoil in mixed populations treated uniformly with one of these control measures. However, to date there …

Adult Rainbow Trout Habitat Selection In The Henry’S Fork Of The Snake River, Idaho, Zachary Kuzniar

Masters Theses

Determining habitat selection for an organism across a geographic distribution is a primary challenge in modern behavioral ecology. Quantifying habitat use becomes increasingly difficult for species that exhibit complex life histories and complementary habitat requirements. Rainbow trout are an archetypal example due to their tendency to form local populations across a diversity of environments. The Henry’s Fork of the Snake River provides an opportunity to utilize microhabitat selection models to quantify stream features that may drive adult rainbow trout behavior at the local scale. In particular, within an 8.5 km, low gradient, groundwater-dominated reach that exhibits a general lack of …

Chemical Disinfectants For The Inactivation Of The Emerging Foodborne Aichi Virus, Andres Ignacio Arreaza

Masters Theses

Aichi virus (AiV) is an emerging virus responsible for gastroenteritis outbreaks worldwide. Improved decontamination methods are being researched to control AiV spread. The effects of common hard surface disinfectants including benzalkonium chloride (BAC), potassium peroxymonosulfate (KPMS), tribasic sodium phosphate (TSP) as well as sodium metasilicate (SMS) and calcium hypochlorite (Ca(ClO)₂) [calcium hypochlorite] against AiV need to be explored. The objective of this research was to determine their effects against AiV using suspension and carrier tests over various contact times at room temperature. Phosphate buffered saline (pH 7.2 as control), 0.64% BAC, 10% KPMS, 10% TSP, 0.16 and 0.3% …

Effects Of Bedding With Recycled Sand On Lying Behaviors, Udder Hygiene, And Preferences Of Lactating Holstein Dairy Cows, Heather Deanna Ingle

Masters Theses

Effects of bedding with recycled sand and season on lying behaviors, stress, hygiene, and preferences of late-lactation Holstein cows were studied. Cows (n=64) were divided into 4 groups (n=8 per group) per season. In summer (Aug-Sept), cows were balanced by days in milk (268.1±11.9 d) and parity (2.0±0.2). In winter (Jan-Feb), mean DIM was 265.5±34.1 d. Cows were assigned to one of two treatments (trt) using a crossover design with each trt lasting 7-d (no-choice phase): bedding with recycled sand (RS; n=32) or control (CO; clean sand; n=32). Stocking density was maintained at 100%. Choice phase allowed a cow to …

Confirming Resistance To Prodiamine And Glyphosate In A Single Annual Bluegrass (Poa Annua L.) Biotype From Tennessee, Shane Matthew Breeden

Masters Theses

Annual bluegrass (Poa annua L.; POAAN) is a cool-season weed that commonly infests warm-season turfgrasses during winter dormancy. In spring 2012, poor POAAN control (<50%) was reported on golf course roughs in Alcoa, TN (35.75 °N, -83.88 °W) following treatment with a tank mixture of prodiamine (1120 g ha^-1[hectare]) and glyphosate (840 g ae ha^-1) during bermudagrass dormancy. The objective of this research was to determine if this POAAN biotype was resistant to prodiamine and glyphosate.

Using mature plants from the field, 81 of the 100 selections were not controlled by glyphosate and prodiamine; 96 of the 100 selections were not controlled by glyphosate, while 84 were unaffected by prodiamine. Only a single plant sampled was susceptible to both herbicides. …

Physiological Evaluation And Root Morphological Differences Associated With Novel Drought Tolerant Corn (Zea Mays L.) Hybrids, Austin Gentry Scott

Masters Theses

Corn hybrids designated “drought tolerant” (DT) from three commercial seed companies were evaluated in order to determine the benefit of DT technology in a mid-south environment that may receive adequate but often poorly timed rainfall. Field research was conducted in 2014 and 2015 at Milan, TN where hybrid response to stress was evaluated at two planting dates and in non-irrigated and irrigated environments and greenhouse research was conducted in Jackson, TN to evaluate early season drought to plant physiology and root structure.

In 2014 and 2015, the non-irrigated trials received enough rainfall to create a high yielding environment. Since the …

Determination Of Dispersal Patterns And Characterization Of Important Habitats For Lake Sturgeon Restoration In The Upper Tennessee River System, Christina Grace Saidak

Masters Theses

Lake Sturgeon, Acipenser fulvescens, are one of the slowest to reach sexual maturity and longest-lived freshwater fish species in North America. These fish are a species of special concern by the U.S. Fish and Wildlife Service, a vulnerable species by the American Fisheries Society (Jelks et al. 2008), and a threatened species in Tennessee (Chiasson et al. 1997; Williams et al. 1989). They have been reintroduced into the Upper Tennessee River system since 2000.

Since December 2013, 49 Lake Sturgeon have been implanted with ultrasonic acoustic transmitters, and 26 fixed-station receivers installed throughout the Upper Tennessee River System to …

Analysis Of Beef Cattle Producers’ Propensity To Adopt Pasture Management And Prescribed Grazing East Of The 100th Meridian, Kristen Elizabeth Oliver

Masters Theses

Pasture management and grazing practices affect animal productivity, soil carbon storage and soil and water quality. Poor pasture and grazing management practices can cause soil erosion, nitrogen leaching, and runoff into streams and waterways. Based on a survey of cattle farmers east of the 100^th meridian, the following two papers estimate how farm operator, farming operation, and attitudinal variables influence the propensity to use pasture management and prescribed grazing, as well as use of specific pasture management and prescribed grazing practices.

Key findings from the first paper are that individual pasture management and prescribed grazing practices are strong indicators …

Phylogenetic Analysis And Revision Of The Nearctic Androprosopa Mik (Diptera: Thaumaleidae) With An Emphasis On The Western Species, Robert John Pivar

Masters Theses

The family Thaumaleidae, also known as seepage midges, is an uncommonly encountered, understudied family of aquatic Diptera compared to its sister group, the Simuliidae. The goal of this project was to assess species diversity of the Nearctic Thaumaleidae and determine relationships among them. The western Nearctic fauna of Androprosopa Mik is revised to include twenty-eight species, six of which are described as new to science. Descriptions of the adult males of A. apache, A. arnaudi, A. magnipelvim, A. rainierensis, A. sierra and A. uvas are provided. Redescriptions of all remaining species are also provided, as well …

Evaluation Of A Natural Antimicrobial-Based Sanitizer As An Alternative To Chlorine For Reducing Foodborne Pathogenic Bacteria On Organic Produce, Ellen Rebecca Simmons

Masters Theses

There is a need for the development of a “natural” sanitizing agent to reduce or eliminate foodborne pathogens that meets USDA organic standards, as an alternative to chlorine. The sanitizer needs to eliminate foodborne pathogens and prevent cross contamination in rinse liquids in the presence of organic matter. In this study, the focus was to evaluate a natural antimicrobial-based sanitizing (NABS) agent in rinse liquids to determine if it was capable of eliminating foodborne pathogens on organic produce through cross-contamination studies. Five-serovar/strain cocktails of pathogenic bacteria were combined to form an inoculum cocktail, which was used to inoculate the produce. …

Improving Management And Species Selection Of Warm-Season Forage Grasses For Southeast Production Systems, Christine Helen Gelley

Masters Theses

Beef producers need drought tolerant options when selecting forage grasses and also practical methods to estimate forage nutritive value, which this study aims to provide for warm-season grasses. The objective of the first experiment was to develop estimates of warm-season forage nutritive value and herbage mass based on harvest timing. The experiment was conducted from 2013 to 2015 at the University of Tennessee Plateau AgResearch and Education Center (PREC) in Crossville, TN. Four species were evaluated, each for two years: bermudagrass [Cynodon dactylon (L.) Pers. cv. Vaughn’s # 1], switchgrass [Panicum virgatum (L.) cv. Alamo], sorghum-sudangrass [Sorghum …

Rare Occurrences Of Free-Living Bacteria Belonging To Sedimenticola From Subtidal Seagrass Beds Associated With The Lucinid Clam, Stewartia Floridana, Aaron M. Goemann

Masters Theses

Lucinid clams and their sulfur-oxidizing endosymbionts comprise two compartments of a three-stage, biogeochemical relationship among the clams, seagrasses, and microbial communities in marine sediments. A population of the lucinid clam, Stewartia floridana, was sampled from a subtidal seagrass bed at Bokeelia Island Seaport in Florida to test the hypotheses: (1) S. floridana, like other lucinids, are more abundant in seagrass beds than bare sediments; (2) S. floridana gill microbiomes are dominated by one bacterial operational taxonomic unit (OTU) at a sequence similarity threshold level of 97% (a common cutoff for species level taxonomy) from 16S rRNA genes; …

Efficacy Of Extending The Voluntary Waiting Period In Lactating Dairy Cows To Improve Fertility Of Sex-Sorted Semen, Sarah E. Orr

Masters Theses

The objective of this study was to compare fertility of sex-sorted semen in lactating cows using a voluntary waiting period (VWP) of approximately 55 days (VWP55) or 85 days (VWP85). At 21 days in milk (DIM), cows were randomly assigned to begin estrus synchronization at 55 or 85 DIM. Only cows confirmed cyclic by 55 DIM were synchronized. At 55 or 85 DIM, cows [VWP55 (n=44); VWP85 (n=45)] having a corpus luteum (CL) were administered PGF_2α [two alpha]. Estrus was monitored continuously by the HeatWatch® [registered sign] system ( …

Efficacy Of Visual Surveys For White-Nose Syndrome At Bat Hibernacula, Amanda Frances Janicki

Masters Theses

White-Nose Syndrome (WNS) is an epizootic disease in hibernating bats caused by the fungus Pseudogymnoascus destructans. Surveillance for P. destructans at bat hibernacula consists primarily of visual surveys of bats, collection of potentially infected bats, and submission of these bats for laboratory testing. Cryptic infections (bats that are infected but display no visual signs of fungus) could lead to the mischaracterization of the infection status of a site and the inadvertent spread of P. destructans. We determined the efficacy of visual detection of P. destructans by examining visual signs and molecular detection of P. …

Identification Of Purinyl-Cobamide As A Novel Corrinoid Cofactor Of Tetrachloroethene Reductive Dehalogenases In Desulfitobacterium Spp., Meng Bi

Masters Theses

Corrinoids (e.g. vitamin B₁₂) [cyanocobalamin] are a group of structurally similar, cobaltcontaining tetrapyrrole compounds involved in a number of important biochemical reactions. In organohalide respiration, vitamin B₁₂ analogues carrying different lower bases are obligate cofactors for the reductive dehalogenases (RDases) that catalyze reductive dechlorination reactions. The focus of this research was on the isolation and characterization of a novel natural corrinoid cofactor that enables the dechlorination-coupled energy conservation in organohaliderespiring Desulfitobacterium strains. Analysis of the purified corrinoid in the cyano form using a combination of high-performance liquid chromatography (HPLC), UV-Vis [Ultraviolet–visible spectroscopy] and ultra-performance liquid chromatography-high-resolution mass …

Long-Term Impacts Of Conservation Management Practices On Soil Carbon Storage, Stability, And Utilization Under Cotton Production In West Tennessee, Candace Brooke Wilson

Masters Theses

Biogeochemical cycling of soil carbon (C) is heavily influenced by conservation agricultural (CA) practices. This study examined SOC stability under three CA practices: reduced nitrogen (N) fertilizer application rate, cover cropping, and zero-tillage implemented for 31 years. Respiration rates measured from a 602-day incubation period were fitted to a double-pool first order exponential model of SOC decomposition. The active [respired] SOC pool showed distinct differences between applications of reduced (34N kg ha^-1 [-1]) and high fertilization rates (101N kg ha^-1) combined with tillage, and suggest that high fertilizer applications with conventional tillage allocated more C into a …

Associations Of Cooking Self-Efficacy And Frequency Of Icook-4h Youth Participants With Dietary Quality And Bmi At Baseline, Amber Donaldson Ford

Masters Theses

Background: With increased obesity has come increased ready-made and fast food consumption and decreased homemade food consumption. Previous studies have shown associations between cooking self-efficacy (SE) and cooking frequency (CF) with dietary quality and weight status. Cooking interventions have shown positive associations with dietary outcomes, such as increased fruit and vegetable intake and decreased fast food consumption. There is still much unknown about SE and CF, especially among youth.

Objective: The objective of this project was to determine baseline SE and CF and the associations with dietary quality and body mass index (BMI) of youth enrolled in iCook 4-H.

Methods: …

A New Adaptive Landscape: Urbanization As A Strong Evolutionary Force, Lauren Christie Breza

Masters Theses

Urbanization is rapidly increasing as human population growth steadily grows, but there is little consensus of the ecological consequence of this population shift and almost no information of the evolutionary consequences for local biodiversity. Nearly two-thirds of the world’s population will live in city centers by 2050 with profound impacts on landscapes that can act as important agents of selection. This study aims to identify 1) the net effect of urbanization on species richness, 2) how phylogenetic diversity varies between urban and rural sites, and 3) the strength of urbanization as a selection pressure. First, a meta-analysis was conducted in …

Environmental Controls On The Diversity And Distribution Of Endosymbionts Associated With Phacoides Pectinatus (Bivalvia: Lucinidae) From Shallow Mangrove And Seagrass Sediments, St. Lucie County, Florida, Thomas Walters Doty

Masters Theses

Lucinid bivalves are capable of colonizing traditionally inhospitable shallow marine sediments due to metabolic functions of bacterial endosymbionts located within their gills. Because lucinids can often be the dominant sediment infauna, defining their roles in sediment and pore fluid geochemical cycling is necessary to address concerns related to changes in coastal biological diversity and to understanding the sensitivity of threatened coastal ecosystems over time. However, there has been limited research done to understand the diversity and distribution of many lucinid chemosymbiotic systems. Therefore, the goals of this thesis were to evaluate the distribution of Phacoides pectinatus and its endosymbiont communities …

Effects Of Low-Dose Naltrexone On Feed Intake, Growth, Endocrine And Immune Parameters In The Recently-Weaned Pig, Ashley Christine Carter

Masters Theses

Weaning is a stressful event for pigs and causes decreased feed intake, poor growth, and increased susceptibility to disease. Previous studies have shown that syndyphalin-33, a synthetic opioid, was effective in increasing feed intake, abrogating the changes in appetite regulating genes during weaning, and abrogating the effects of a salmonella challenge on immune cells in newly-weaned pigs. However, there are several concerns associated with the administration of an opioid in commercial swine operations. Low-dose naltrexone (an opioid antagonist) has been used to alleviate symptoms from fibromyalgia and Crohn’s disease in humans. As inflammation is a common factor in both auto-immune …

4-H Wildlife Habitat Education Program: A Qualitative Study On Career Exploration, Ronnie Lee Cowan

Masters Theses

There are documented studies on the Wildlife Habitat Education Program (WHEP) that relate to building life skills of participants. However, no literature was found that measured the perceptions of the participants towards a career in wildlife after participating in WHEP. To add validity to the program a focus group was conducted at the Tennessee 4-H wildlife judging contest to describe the WHEP participants’ perceptions of careers in wildlife after the completion of the annual program. Focus group participants indicated that participating in WHEP peaked their interest in wildlife and provided an opportunity to experience the importance of natural resource management.

Interactions Among Insect Defoliation, Insecticide Treatments, And Growth Rate In American And Hybrid Chestnuts, Ashley Elizabeth Case

Masters Theses

The American chestnut, Castanea dentata, was once one of the most useful and abundant canopy trees in eastern North American forests. Over the last 200 years, the species has been decimated by two exotic pathogens, Phytophthora cinnamomi and Cryphonectria parasitica, killing millions of trees and reducing surviving Castanea dentata to short-lived sprouts. Cryphonectria parasitica-resistance breeding programs are currently producing advanced backcross generations, which are being compared with pure American chestnut in field tests of growth performance and Cryphonectria parasitica resistance. The Asiatic oak weevil, Cyrtepistomus castaneus, has been identified as a common defoliator of chestnut seedlings in these …

Cowpea Adaptability To Southeastern Organic Farming Systems: Forage Productivity And Charcoal Rot Susceptibility, Samantha Lindsey Hill

Masters Theses

Cowpea (Vigna unguiculata (L.) Walp.) is a warm-season, multi-purpose legume that is well-adapted to the southeastern USA and has many traits that make it an attractive forage or cover crop for integration into organic production systems, including high rates of nitrogen (N) fixation, phosphorus (P) use efficiency, regrowth ability, and high digestibility. Eight cowpea varieties were evaluated under organic management at two locations in summer 2014 for stand establishment, forage yield and quality, and weed biomass.

Charcoal rot [Macrophomina phaseolina (Tassi) Goid.] is a fungal disease that is economically important to many host plant species. High temperatures and …

Effects Of Forest Management Practices On Raccoon Ecology In A Longleaf Pine Ecosystem, Ronald Brian Kirby

Masters Theses

Raccoons (Procyon lotor) are ecological generalists common throughout a variety of habitats across their range. Although considered an economically important furbearer species in many regions, they are considered potentially important nest predators of certain species. Because raccoons may have a significant ecological impact on the landscape, it remains important to understand their ecology in a variety of ecosystems. We studied raccoon ecology in a longleaf pine ecosystem in southwestern Georgia, where little information for the species exists. Specifically, we assessed 269 daytime resting sites (i.e., refugia) associated with 31 radio-collared adult raccoons (18M, 13F) during 2014-2015 using an …

Removal Of Trace Organic Compounds In Domestic Wastewater Using Recirculating Packed-Bed Media Filters, Brittani Nikole Perez

Masters Theses

Pharmaceuticals and personal care products (PPCPs) are commonly detected in the environment resulting from their survival from conventional wastewater treatment systems. More information is needed about the fate and transfer of these trace organic compounds in domestic wastewater and their associated risks so that efficient strategies for their removal can be developed for both large/small scale treatment systems. This study aimed to determine whether onsite wastewater treatment systems were capable of providing PPCP removal, in addition to quantifying different forms of removal (biodegradation/sorption). A column study was constructed to determine the removal efficiencies of 3 target PPCPs, endocrine disrupting compound …

Potential Interaction Between Pre- And Post-Emergence Herbicides And The Efficacy Of Insecticide And Fungicide Seed Treatments In Cotton, Cory Joseph Vineyard

Masters Theses

An apparent reduction in the performance of neonicotinoid seed treatments in controlling thrips, especially in cotton, has been observed, which has coincided with the increased use of both pre- and post-emergence herbicides to control glyphosate-resistant weeds. The objective of this research was to evaluate the potential interactions of both pre- and post-emergence herbicides on the efficacy of insecticide and fungicide seed treatments in cotton

Aldicarb along with imidacloprid and thiamethoxam seed treatments reduced thrips numbers compared with non-treated seed. However, thiamethoxam did not provide effective control. Some pre-emergence herbicide treatments reduced plant health. While there was evidence that thrips injury …

Impact Of Milk Production Level On Beef Cow-Calf Productivity In Tennessee, Sarah Rebecca Edwards

Masters Theses

The beef cattle industry tends to focus on selecting production traits with the purpose of maximizing cow-calf performance. One such trait is milking ability, which is considered the primary influence on weaning weight of the calf. But, it can also have a negative effect on cow reproductive efficiency and cost of production. Therefore, the objective of this study was to determine the effect of actual milk yield on reproductive performance, circulating blood metabolites, and calf performance in beef cows in Tennessee. Data were collected from 239, 3- to 9-yr-old Angus sired beef cows from 3 research centers across Tennessee. On …

Expression Of Insulin Responsive Genes In Insulin Resistant Conditions, And The Effect Of Selenium On Gene Expression, David L. Ruff

Masters Theses

Chronically high blood glucose levels lead to many problems, such as insulin resistance, the hallmark of Type II diabetes. Increased flux through the hexosamine biosynthesis pathway is one mechanism by which high glucose as well as glucosamine has been shown to induce insulin resistance. This study tests the effects of glucosamine induced insulin resistance on insulin regulation of the metabolic genes glucose-6-phosphate dehydrogenase (G6PDH) and fatty acid synthase (FAS) as well as insulin responsive proteins tribbles homolog (TRIB3) and sterol regulatory element binding protein (SERBP-1c) 1c.

Selenium, a micronutrient has been shown to be an effective insulin mimetic in Type …

Subfunctionalization Of Ethylene Receptors And Homology Modeling Of Cytosolic Domains In Arabidopsis Thaliana, Sai Keerthana Wuppalapati

Masters Theses

Ethylene is a gaseous phytohormone that initiates and modulates several mechanisms related to growth and development in plants through a family of five disulphide-linked receptor dimers. Although the ethylene receptors are very similar in their structures, they have diverse functions with both overlapping and non-overlapping roles. Silver ions are able to support ethylene binding to the receptors but it is also interesting to note that ethylene responses are blocked in the presence of silver. A part of the present study identified that ETR1 receiver domain has little or no role in mediating responses to silver ions, supported by data obtained …

Multi-Segment Foot Coordination Of The Treated Clubfoot, Amy Whited

Masters Theses

Idiopathic congenital clubfoot can be treated either operatively (comprehensive surgical release (CSR)) or conservatively (ponseti technique (PCT)). This thesis compared the mid-term outcomes after CSR and PCT treatments to a typically developing sample. A Dynamical Systems Analysis (DSA) approach and a multi-segment foot model were used to examine group differences in multi-segment foot and lower extremity kinematics, kinetics, coordination and coordination variability during walking. Ten children with clubfoot treated with PCT and seven children with clubfoot treated with CSR were evaluated retrospectively and compared to ten typically developing children. Multi-segment foot and lower extremity kinematic (240 Hz) and kinetic (1080 …