Life Sciences Commons^™

Investigating Genetic Differences Between Strains Of Janthinobacterium Lividum On Salamanders And In Their Environment, Rhiannon E. Black

Chancellor’s Honors Program Projects

No abstract provided.

The Effect Of Heat Stress And Essential Amino Acids On Production And Metabolism Of Lactating Dairy Cattle, Kimberly Rose Kassube

Masters Theses

Heat stress (HS) causes decreases in production of lactating cattle that is only partially explained by decreases in intake. Evidence suggests that changes in energy and protein metabolism occur to cope with the impact of HS. The objective of this thesis was to determine if the effect of jugular infusion of essential amino acids (AA) ameliorated the negative effects of HS in milk production and metabolism. Twelve multiparous lactating Holstein cows were used in a crossover design to evaluate the effect of thermoneutral (THN) and HS environments along with the absence (CTL) …

Testing The Temporal Stability Of The Climate Response Of Tree Species At Norris Dam State Park, Tennessee, U.S.A., Allison Elizabeth Ingram

Masters Theses

Temporal stability of the climate-tree growth relationship means that over time, tree species were responding to a specific climate variable and continue to respond to that variable into the present. The stability of this response is important to test prior to attempting to reconstruct past climate. In this study, I sampled oaks (white oak = Quercus alba L. and chestnut oak = Quercus montana Willd.) and pines (Virginia pine = Pinus virginiana Mill. and shortleaf pine = Pinus echinata Mill.) growing in Norris Dam State Park in eastern Tennessee and tested the temporal stability of these species and their potential …

Influence Of Application Technology On Foliar Fungicide Efficacy On Cercospora Sojina Infected Soybean, Shawn Alan Butler

Masters Theses

Due to the constant concern with off-target contamination and application technology requirements associated with future herbicide-tolerant crops, the use of drift-reduction nozzle technology (DRT) may increase. The primary objective of this research was to evaluate the effects of coarse droplets generated by drift-reduction nozzles on foliar fungicide efficacy and residual in soybean infected by frogeye leaf spot caused by Cercospora sojina. No differences in disease control, soybean yield, spray retention, and residual when applying Quadris Top SB, a premix of azoxystrobin and difenoconazole, using nozzles that produce either a medium or ultra coarse droplet spectrum were determined.

Due to …

Combinations Of Multiple Natural Antimicrobials With Different Mechanisms As An Approach To Control Listeria Monocytogenes, Savannah Grace Hawkins

Masters Theses

To improve food safety and shelflife requires the use of preservation processes, such as physical (heat, refrigeration) or chemical (antimicrobial addition) processes. Regulatory approved synthetic food antimicrobials (preservatives) have some uses but are very limited in their spectrum of activity. Thus, alternatives are needed to conventional chemical antimicrobials. One method is to use naturally occurring antimicrobials, especially those found in spices and herbs, essential oils (EO) and essential oil components (EOC). EOs have been shown to have antimicrobial activity but the activity is highly variable. Finding a combination of EOs, EOCs, or other natural antimicrobials that act synergistically would allow …

Association Of Genotype At Drd2 With Growth And Reproductive Performance Traits In Bulls Grazing Toxic Endophyte-Infected Tall Fescue, Kaysie Jennings

Masters Theses

Fescue toxicosis can negatively impact growth and fertility of beef cattle grazing tall fescue infected with an endophytic fungus. The fungus produces ergot alkaloids that contribute to the hardiness of the plant, but can be detrimental to the animal if consumed. A single nucleotide polymorphism (SNP) in the dopamine receptor D2 gene (DRD2) has been associated with serum prolactin concentrations and hair coat scores in cattle grazing toxic endophyte-infected (TE) tall fescue; cattle with the GG genotype had decreased serum prolactin concentrations and increased hair coat scores. Separately, heifers with the AA genotype calved sooner than AG or GG heifers. …

Microbial Extracellular Enzymes In Marine Sediments: Methods Development And Potential Activities In The Baltic Sea Deep Biosphere, Jenna Marie Schmidt

Masters Theses

The deep biosphere is defined as the subsurface ecosystem in which little energy is available to microorganisms and microorganisms can live for thousands of years. Heterotrophic microbes survive in the deep biosphere even though organic matter is limited and highly recalcitrant in nature. Measuring microbial extracellular enzyme activity provides a potential means to evaluate the rate at which microorganisms are performing carbon remineralization in the energy limited sediment beneath the seafloor. Extracellular enzymes breakdown organic compounds so that the nutrients can move inside the cell and be used for energy. This study explored the role extracellular enzymes play in the …

Identification Of Potential Bacterial Surrogates For Validation Of Thermal Inactivation Processes Of Hepatitis A Virus, Marcel Schmidt

Masters Theses

Thermal treatment is a method for inactivating pathogens in a wide range of food products. Recent studies have shown that hepatitis A virus (HAV) has a D_72°C [D72 degree celcius] of 0.9 min in buffer which is greater than vegetative bacterial pathogens. Common surrogates, such as Listeria innocua, are not resistant enough to be used as surrogates for HAV, thus, new surrogates need to be identified. The purpose of this study was to compare the thermal inactivation kinetics (D- and z-values) of Staphylococcus carnosus in different foods and different incubation temperatures to identify a potential surrogate for HAV. …

Anthrax Models Involving Immunology, Epidemiology And Controls, Buddhi Raj Pantha

Doctoral Dissertations

This dissertation is divided in two parts. Chapters 2 and 3 consider the use of optimal control theory in an anthrax epidemiological model. Models consisting system of ordinary differential equations (ODEs) and partial differential differential equations (PDEs) are considered to describe the dynamics of infection spread. Two controls, vaccination and disposal of infected carcasses, are considered and their optimal management strategies are investigated. Chapter 4 consists modeling early host pathogen interaction in an inhalational anthrax infection which consists a system of ODEs that describes early dynamics of bacteria-phagocytic cell interaction associated to an inhalational anthrax infection.

First we consider a …

Improving Aedes Mosquito Surveillance And La Crosse Virus Screening In Eastern Tennessee, Cassandra Urquhart

Masters Theses

La Crosse virus (LACV), transmitted by infected Aedes triseriatus, Ae. albopictus, and Ae. japonicus mosquitoes is the leading cause of pediatric arboviral encephalitis. Severe cases of LAC encephalitis occur in individuals 16-years-old or younger and may cause permanent neurological damage or fatality. No vaccines exist making mosquito control and disease prevention crucial to public health. Effective screening and surveillance practices are key components to these goals. While a number of standard mosquito surveillance methods exist, continuous testing and improved understanding of vector biology to determine the best ways to implement these methods is important. Additionally, the current standard …

Soil-Water Transport Of A Seed Coated Neonicotinoid Pesticide In Soybean/Maize Cultivation Systems, Geoffrey Nathaniel Duesterbeck

Masters Theses

The current decline of the honey bee (Apis mellifera L.) and other beneficial pollinator species is well documented. Several causes have been cited in this decline including: pathogens, pests, nutrition, and pesticide exposure. Since the advent of the neonicotinoid family of pesticides in the 1990’s an increase in honey bee colony loss has been observed. Neonicotinoid pesticides are commonly applied as a seed treatment to cotton, soybean and maize row crops. As the seed germinates, it absorbs the pesticide from the coating then spreads systemically throughout the entire plant. However, a large portion of the seed coating may stay …

An Online Study Of Undergraduates' Knowledge, Awareness, And Attitudes Of Preconception Care, Kelly Jean Crusenberry

Masters Theses

Background: The majority of pregnancies in the United States are unplanned. Health status and health-related behaviors such as poor nutrition, alcohol consumption, and/or tobacco use, occurring prior to conception, have been linked to poor obstetric outcomes for mothers and their offspring, many of which can result in lifelong challenges. Knowledge, awareness, and attitudes can be predictors of health-related behaviors, and preconception care and education may reduce risk of some of these poor obstetric outcomes. Undergraduate students are at an increased risk for many of these risky behaviors and for unplanned pregnancies, as compared to older individuals. However, little is known …

Chemokines And Peptides That Promote And Inhibit Cmv Entry, Elisabeth Anne Pitt

Masters Theses

Human cytomegalovirus (HCMV) causes morbidity and mortality in congenitally infected newborns, transplant recipients, and AIDS patients. Currently, there is no approved CMV vaccine to address these issues. In an effort to develop an alternative treatment to CMV we tested our hypothesis that heparan sulfate binding D-peptides would be effective against multiple HCMV strains in vitro and it would be effective in vivo against murine CMV (MCMV) (Chapter 1). We show that the D-peptide is able to reduce CMV infection in vitro and in vivo. Another approach to combating CMV infections is to neutralize pathogenic factors that contribute to CMV …

An Ecological Study Of The Kudzu Bug In East Tennessee: Life History, Seasonality, And Phenology, Kadie Elizabeth Britt

Masters Theses

The kudzu bug, Megacopta cribraria (Hemiptera: Plataspidae), an invasive species from Asia, was first discovered in the United States in 2009 in Georgia. It has since spread to other states, including Tennessee, where it has spread rapidly to numerous counties in four years. Its common name, kudzu bug, implies a potential benefit to management of the invasive species kudzu; unfortunately, the kudzu bug has shown little impact on reducing growth of kudzu. The kudzu bug causes agricultural, urban, and health-related concerns in the United States. Soybean losses by kudzu bug have exceeded 20% in some areas of the southeastern United …

Regional Dynamic Price Relationships Of Distillers Dried Grains In U.S. Feed Markets, Matthew Fulton Johnson

Masters Theses

Distillers dried grains with solubles (DDGS) is now a mainstream substitute in U.S. animal feed rations. DDGS is rich in fat and protein content and serves as a competitive feed source in livestock markets. The objective of this study is to identify dynamic price relationships among DDGS, corn, soybean meal, and livestock outputs in context of specific livestock sectors and their geographic location. Four locations associated with a predominant livestock sector are selected for analysis by measuring density and relative proportion of a livestock sector’s grain consumption at the county level. A vector error correction model is applied to post-mandate …

Forage Availability And Nutritional Carrying Capacity For Cervids Following Prescribed Fire And Herbicide Applications In Young Mixed-Hardwood Forest Stands In The Cumberland Mountains, Tennessee, Jordan Scott Nanney

Masters Theses

I evaluated the influence of timber harvest combined with prescribed fire and/or herbicide in young mixed-hardwood forest on forage availability and nutritional carrying capacity (NCC) for elk (Cervus elaphus) and white-tailed deer (Odocoileus virginianus) at the North Cumberland Wildlife Management Area (WMA), July-August, 2013-15. I combined land cover data, forest management data, field management data, and forage availability data to model summer elk forage availability across the WMA.

I compared forage availability, NCC (animal days/ha) using 12 and 14% crude protein (CP) nutritional constraints, and vegetation composition among 6 young forest treatments, reclaimed surface mines (MINE), and closed-canopy mature forest …

Retained Ownership Profitability Of Beef Cattle Originating In Tennessee, Minfeng Tang

Masters Theses

Retained ownership is a marketing strategy that can be used by cow-calf operators to benefit from the potential increase in fed cattle prices. We analyze the profitability of retained cattle ownership from 2005 to 2015 for cow-calf producers in Tennessee. We also determine the impact of steer/heifer characteristics (e.g., average daily gain, feed conversion) and producer choice decisions (e.g., placement weight, placement season, days on feed) on retained ownership profitability. Data on 2,953 head of cattle originating in Tennessee and finished in Iowa using a retained ownership strategy were collected. A mixed regression model explaining profitability was estimated with fixed …

Convergence To Consensus In Heterogeneous Groups And The Emergence Of Informal Leadership, Sergey Gavrilets, Jeremy David Auerbach, Mark Van Vugt

Faculty Publications and Other Works -- Ecology and Evolutionary Biology

When group cohesion is essential, groups must have efficient strategies in place for consensus decisionmaking. Recent theoretical work suggests that shared decision-making is often the most efficient way for dealing with both information uncertainty and individual variation in preferences. However, some animal and most human groups make collective decisions through particular individuals, leaders, that have a disproportionate influence on group decision-making. To address this discrepancy between theory and data, we study a simple, but general, model that explicitly focuses on the dynamics of consensus building in groups composed by individuals who are heterogeneous in preferences, certain personality traits (agreeability and …

Volume 12, Number 1 (Spring/Summer 2016), Ut Institute Of Agriculture

Tennessee Land, Life and Science Magazine

Issue Highlights:

• The four pillars of the Institute of Agriculture
• Alumna forges partnership amid Waldo Canyon fire
• Fishery biologists revive a river

Quantifying Limits On Replication, Death, And Quiescence Of Mycobacterium Tuberculosis In Mice, Margaret M. Mcdaniel, Nitin Krishna, Winode G. Handagama, Shigetoshi Eda, Vitaly V. Ganusov

Microbiology Publications and Other Works

When an individual is exposed to Mycobacterium tuberculosis (Mtb) three outcomes are possible: bacterial clearance, active disease, or latent infection. It is generally believed that most individuals exposed to Mtb become latently infected and carry the mycobacteria for life. How Mtb is maintained during this latent infection remains largely unknown. During an Mtb infection in mice, there is a phase of rapid increase in bacterial numbers in the murine lungs within the first 3 weeks, and then bacterial numbers either stabilize or increase slowly over the period of many months. It has been debated whether the relatively constant numbers of …

Transgenic Plant-Produced Hydrolytic Enzymes And The Potential Of Insect Gut-Derived Hydrolases For Biofuels, Jonathan D. Willis, Mitra Mazarei, C. Neal Stewart Jr.

Plant Sciences Publications and Other Works

Various perennial C4 grass species have tremendous potential for use as lignocellulosic biofuel feedstocks. Currently available grasses require costly pre-treatment and exogenous hydrolytic enzyme application to break down complex cell wall polymers into sugars that can then be fermented into ethanol. It has long been hypothesized that engineered feedstock production of cell wall degrading (CWD) enzymes would be an efficient production platform for of exogenous hydrolytic enzymes. Most research has focused on plant overexpression of CWD enzyme-coding genes from free-living bacteria and fungi that naturally break down plant cell walls. Recently, it has been found that insect digestive tracts harbor …

Benefits And Risks Of Imidacloprid-Based Management Programs For Hemlock Woolly Adelgid, Elizabeth Paige Benton

Doctoral Dissertations

Hemlock woolly adelgid, Adelges tsugae (Annand) (HWA) (Hemiptera: Adelgidae), has caused widespread decline of eastern hemlock, Tsuga canadensis (L.) Carriére. This collaborative retrospective analysis with Great Smoky Mountains National Park (GRSM) provides research-based management guidance on imidacloprid treatments and nontarget risks to aquatic systems.

Imidacloprid and olefin concentrations were assessed in foliage from different diameter at breast height (DBH) size hemlocks 4 – 7 yr post-imidacloprid treatment. Imidacloprid concentrations were below the LC₅₀ [lethal concentration] for HWA, but olefin was above the LC₅₀ 4 yr post-treatment. HWA populations were suppressed, and hemlock canopies were healthy. Treatment efficacy can …

Biophysical Studies Of Cell Division Protein Localization Mechanisms In Escherichia Coli, Matthew Wayne Bailey

Doctoral Dissertations

How nanometer-scale proteins position accurately within micron-scale bacteria has intrigued both biologists and physicists alike. A critical process requiring precise protein localization is cell division. In most bacteria, cell division starts with the self-assembly of the FtsZ proteins into filaments that form a ring-like structure encircling the cell at its middle, the Z-ring. The Z-ring is a scaffold for additional proteins that synthesize the lateral cell wall which separates the two daughter cells. If division planes are misplaced relative to bacterial chromosomes, also called nucleoids, daughter cells with incomplete genetic material can be produced. In Escherichia coli, research carried out …

Structuring Solid/Oil/Water Emulsions To Deliver Water-Soluble Bioactive Food Ingredients, Yun Zhang

Doctoral Dissertations

Numerous delivery systems are studied for lipophilic bioactive compounds, but much work is needed for bioactive food ingredients soluble or dispersible in water. The overall hypothesis of this dissertation is that structured solid/oil/water (S/O/W) emulsions can be used to encapsulate water-soluble/dispersible ingredients to retain their release during processing and storage and control their release during simulated digestions. The encapsulation principle is to prepare spray-dried powder of water-soluble/dispersible compounds as the solid core that is coated by an oil layer emulsified by food biopolymers. The oil layer isolates the compounds from the continuous aqueous phase in emulsions to prevent the release, …

In Silico Driven Metabolic Engineering Towards Enhancing Biofuel And Biochemical Production, Richard Adam Thompson

Doctoral Dissertations

The development of a secure and sustainable energy economy is likely to require the production of fuels and commodity chemicals in a renewable manner. There has been renewed interest in biological commodity chemical production recently, in particular focusing on non-edible feedstocks. The fields of metabolic engineering and synthetic biology have arisen in the past 20 years to address the challenge of chemical production from biological feedstocks. Metabolic modeling is a powerful tool for studying the metabolism of an organism and predicting the effects of metabolic engineering strategies. Various techniques have been developed for modeling cellular metabolism, with the underlying principle …

Complex Non-Equilibrium Structural Dynamics In Globular Proteins, Xiaohu Hu

Doctoral Dissertations

Internal structural motions in proteins are essential to their functions. In this present dissertation, we present the results from an extensive set of molecular dynamics simulations of three very different globular proteins and demonstrate that the structural fluctuations observed are highly complex, manifesting in non-ergodic and self-similar subdiffusive dynamics with non-exponential relaxation behavior. The characteristic time of the motion observed at a given timescale is dependent on the length of the observation time, indicating an aging effect. By comparing the simulation results to the existing single-molecule fluorescence spectroscopic data on other globular proteins, we found the characteristic relaxation time for …

Systematics, Diversity And Evolution Of The Suborder Tricholomatineae (Agaricales), Marisol Sanchez Garcia

Doctoral Dissertations

The suborder Tricholomatineae is one of the several major groups of Agaricales, the largest order of mushroom-forming fungi. This suborder contains three families: Tricholomataceae, Entolomataceae and Lyophyllaceae, as well as many genera of incertae sedis. Members of the Tricholomatineae exhibit variation in nutritional mode, including mycoparasites, saprotrophs, termite-associates, bryophyte parasites, and ectomycorrhizal (ECM) symbionts, which makes the clade ideal for studying trophic evolution in fungi from a phylogenetic perspective.

This dissertation combines taxonomy and evolutionary analyses to contribute to the knowledge of fungal diversity and mycorrhizal evolution. First, I present a systematic revision of the family Tricholomataceae within a …

Plant-Microbe Interactions Influence Ecosystem Processes: The Role Of Roots And Mycorrhizal Fungal Hyphae On Terrestrial Carbon Dynamics, Jessica Andrea Moore

Doctoral Dissertations

Plant-microbe interactions shape ecosystem processes such as productivity and decomposition of organic matter. Plants interact with mycorrhizal fungal hyphae to acquire nutrients from soil in exchange for plant-assimilated carbon. The mycorrhizal interaction is therefore a key influence on ecosystem carbon dynamics. Mycorrhizal fungi are key players in soil carbon cycling as they stimulate plants to allocate carbon belowground, and mycorrhizal fungal hyphae interact with microbial decomposers of soil carbon. However, there are few studies on mycorrhizal fungal hyphal interactions with roots and soil organisms in light of soil carbon accrual and release, important ecosystem processes. In my doctoral research, I …

Functional Role Of Each Component In Gamma Secretase Complex, Chen Hu

Doctoral Dissertations

Amyloid hypothesis is widely accepted as the centerpiece of Alzheimer’s disease (AD) pathogenesis. It is believed that the accumulation of amyloid beta (Ab) is the major deterministic factor of AD and the most important causative factor is the ratio of Ab42/Ab40. Gamma(g)-secretase defines the length of Ab and is composed of at least four subunits: presenilins (PS1 or PS2), nicastrin (NCT), anterior pharynx-defective 1 (Aph-1), and presenilin enhancer 2 (Pen-2). They have been reported to have different roles in g-secretase. For example, PS were believed as the catalytic components in g-secretase; NCT was recognized as a substrate receptor; Pen-2 was …

Static Frontal Plane Tibiofemoral Alignments And Their Effects On Knee Biomechanics During Level Walking And Stair Ascent Tasks, Hunter Jared Bennett

Doctoral Dissertations

Knee osteoarthritis is a degenerative joint disease that can onset due to abnormal knee adduction moments (KAMs), which are related to frontal plane knee joint alignment. Gait modifications including toe-in (TI) and wider step widths have been proposed as individual intervention strategies, but have not been previously combined, to reduce abnormal frontal plane loading in healthy and osteoarthritic populations. Study One investigated clinical based measurements to predict radiographic frontal plane knee joint alignment, measured as the mechanical axis angle (MA). Study Two compared three different hip joint center estimation methods on MA predictions using three-dimensional motion capture. Study Three and …