Digital Commons Network^™

Using Linked Household-Level Datasets To Explain Consumer Response To Bse In Canada, Xin Wang

University of Kentucky Doctoral Dissertations

Household-level Canadian meat purchases from 2002-2008, a Food Opinions Survey conducted in 2008 at the national level and household-level egg purchases from 2002-2005 in Alberta and Ontario were used to explore consumer responses to Bovine Spongiform Encephalopathy (BSE) in Canada.

The opinions survey focused on nutritional priorities, general and specific food safety concerns, and trust in government and food industry decision makers. The egg data set contained specific product information allowing us to distinguish purchases of conventional eggs from those of value-added eggs with perceived health attributes. Thus, the egg purchase data appeared to be an interesting proxy of revealed …

Effects Of Adipogenic Compounds On Growth Performance, Hormonal Status And Fat Deposition Of Finishing Beef Steers, Susanna Elizabeth Kitts

University of Kentucky Doctoral Dissertations

Processes that regulate site of fat deposition in beef cattle are poorly understood. For the producer to procure the greatest profit, it is ideal to maximize intramuscular fat. Furthermore, to understand the physiological mechanisms affecting fat depots, it is necessary to evaluate hormones involved in growth regulation. Using a 2 x 2 factorial design of treatments, four experiments were conducted to examine two adipogenic compounds, chlortetracycline and dexamethasone. Synovex-S® and Revalor-S® were used to investigate potential interactions between growth implants and adipogenic compound. Growth performance, carcass quality, organ and fat mass and plasma hormone concentrations were measured in these studies. …

Comparison Of Plant‐Adapted Rhabdovirus Protein Localization And Interactions, Kathleen Marie Martin

University of Kentucky Doctoral Dissertations

Sonchus yellow net virus (SYNV), Potato yellow dwarf virus (PYDV) and Lettuce Necrotic yellows virus (LNYV) are members of the Rhabdoviridae family that infect plants. SYNV and PYDV are Nucleorhabdoviruses that replicate in the nuclei of infected cells and LNYV is a Cytorhabdovirus that replicates in the cytoplasm. LNYV and SYNV share a similar genome organization with a gene order of Nucleoprotein (N), Phosphoprotein (P), putative movement protein (Mv), Matrix protein (M), Glycoprotein (G) and Polymerase protein (L). PYDV contains an additional predicted gene between N and P, denoted as X, that has an unknown function. In order to gain …

Efficacy Of Organically Certifiable Materials And Natural Compounds Against Foliar Hemibiotrophic And Necrotrophic Fungi In Cantaloupe And Tomato, Merari Feliciano-Rivera

University of Kentucky Doctoral Dissertations

Kentucky reported a solid 13.1% growth in certified organic land from 1997 to 2002. The relative lack of research on disease management practices in Kentucky consistent with organic regulations is an issue that needs to be addressed to provide more reliable information to local farmers. Thus, the first objective of this research was to investigate the potential disease control obtained with natural, organically certifiable spray materials against Colletotrichum orbiculare in vitro and in vivo. The second objective was to test certifiable spray materials in combinations to identify synergistic interactions. The third objective was to evaluate Organic Material Review Institute …

Intermediate Steps Of Loline Alkaloid Biosynthesis, Jerome Ralph Faulkner

University of Kentucky Doctoral Dissertations

Epichloë species and their anamorphs, Neotyphodium species, are fungal endophytes that inhabit cool-season grasses and often produce bioprotective alkaloids. These alkaloids include lolines, which are insecticidal and insect feeding deterrents. Lolines are exo-1-aminopyrrolizidines with an oxygen bridge between carbons 2 and 7, and are usually methylated and formylated or acetylated on the 1-amine. In previously published studies lolines were shown to be derived from the amino acids L-proline and L-homoserine. In addition the gene cluster involved in loline-alkaloid biosynthesis has also been characterized. In this dissertation a survey of plant-endophyte symbioses revealed a phenotype with only N-acetylnorloline. This …

Comparison Of Digestive Function In Young And Mature Horses, Jennifer Elizabeth Earing

University of Kentucky Doctoral Dissertations

While forage plays an important role in equine nutrition, little research has been conducted evaluating fiber utilization by young horses. Therefore, studies were conducted to compare in vivo digestibility and digesta passage in weanlings and mature horses (Exp 1) and yearlings and mature horses (Exp 2). All horses were fed forage-based diets at the same rate (on a metabolic BW basis; Exp 1: 67% alfalfa cubes, 33% concentrate; Exp 2: 75% timothy cubes, 25% concentrate). Ytterbium labeled hay and cobalt-ethylenediaminetetraacetic acid were used to estimate digesta mean retention time (MRT), while in vivo digestibility (DM, OM, and NDF) was measured …

Restoration Of Tall Fescue Pastures To Native Warm Season Grasslands: Does A Fungal Endophyte Symbiosis Play A Role In Restoration Success?, Sarah Lynn Hall

University of Kentucky Doctoral Dissertations

Tall fescue, a cool-season grass native to Europe, central Asia, and northern Africa, has been widely distributed throughout the U.S. for use as turf and forage. Following its widespread planting, its ability to associate with a toxic fungal endophyte, Neotyphodium coenophialum, was discovered. Research has linked this fescue-endophyte association with increased biotic and abiotic stress resistance in endophyte-infected (E+) versus endophyte-free (E-) plants, and these differences may affect the ability of land managers to eradicate tall fescue and restore native grasslands. I conducted three studies to examine whether E+ tall fescue plants respond differently to management than E- plants, …

Evaluation And Enhancement Of Seed Lot Quality In Eastern Gamagrass [Tripsacum Dactyloides (L.) L.], Cynthia Hensley Finneseth

University of Kentucky Doctoral Dissertations

Eastern gamagrass [Tripsacum dactyloides (L.) L.] is a warm-season, perennial grass which is native to large areas across North America. Cultivars, selections and ecotypes suitable for erosion control, wildlife planting, ornamental, forage and biofuel applications are commercially available. Plantings are commonly established from seed; however, seed quality and dormancy are barriers to establishment. The objective here was to investigate parameters that contribute to inconsistent performance of this seed kind to subsequently improve seed lot quality.

Forty-two seed lots were used, with seed fill and germination potential ranging from 78- 100% and 11-91%, respectively. Actual germination and dormant seed ranged …

Streamflow Prediction Using Gis For The Kentucky River Basin, Bakkiyalakshmi Palanisamy

University of Kentucky Doctoral Dissertations

The study was aimed at developing a simple methodology for flow prediction in ungauged basins using existing data resources. For this purpose, the streamflow measurements across the Kentucky River Basin located in Kentucky, USA were obtained from United States Geological Survey (USGS) archive. The flow transferring characteristics of the subbasins of the Kentucky River Basin were obtained by combining downstream and upstream stream gauges. The flow transferring function thus derived were related to watershed, channel and flow characteristics of the subbasins by multiple regression analysis. The gauge pairs were divided into two classes of subbasins representing Upper and Lower Kentucky, …

Characterization Of Soil Carbon Stabilization In Long-Term Row-Cropped Agro-Ecosystems, Soraya Patricia Alvarado-Ochoa

University of Kentucky Doctoral Dissertations

Soil organic matter (SOM) is a dynamic soil property, sensitive and responsive to many factors. The possibility of increasing soil carbon (C) sequestration by changing land use and management practices has been of great interest recently due to concerns with global changes in the atmospheric carbon dioxide (CO₂) balance. Nonetheless, as a result of the complex dynamics of SOM, there is still the need for SOM characterization procedures capable of monitoring SOM stabilization, taking into account all the factors involved.

This study characterized SOM stabilization as affected by management practices in three long-term field experiments, considering physical, chemical …

Evaluating The Effects Of Organic And Conventional Inputs On Soil Chemical And Biological Properties In A Four-Year Vegetable Rotation And The Investigation Of Soil Microbial Properties On Plant Gene Expression, Audrey Law

University of Kentucky Doctoral Dissertations

The objective of this research was to determine the effects of conventional inputs on soil chemical and biological properties compared to organic systems in a four year vegetable rotation. Tillage and cover crops were the same in all treatments to avoid confounding factors often present in similar research. Additional experiments investigated plant gene expression in organic and conventional management systems and in soils with decreased microbial diversity. Experimental plots were prepared in the spring of 2004; four replications of three management treatments, organic, low-input and conventional, were arranged in a randomized complete block design. The rotation consisted of edamame soybean, …

Colloid Mediated Transport Of Heavy Metals In Soils Following Reclamation With And Without Biosolid Application, Jarrod O. Miller

University of Kentucky Doctoral Dissertations

Soils disturbed by strip mining practices may have increased colloid loads moving to groundwater resources, also enhancing the transport of contaminants into our water resources. We hypothesize that contaminant transport within soils following mining is enhanced by colloid mobility. Two sites were chosen for this study, a 30-year old reclaimed strip mine in southwest Virginia and a recently mined area from eastern Kentucky. Intact reclaimed soil monoliths were retrieved from sandstone derived soils in southwestern Virginia. Reclaimed monoliths from eastern Kentucky were recreated in the lab. Intact undisturbed (native) soil monoliths representing the soils before mining were also sampled for …

Map-Based Cloning Of An Anthracnose Resistance Gene In Medicago Truncatula, Shengming Yang

University of Kentucky Doctoral Dissertations

Anthracnose, caused by the fungal pathogen Colletotrichum trifolii, is one of the most destructive diseases of alfalfa worldwide. Cloning and characterization of the host resistance (R) genes against the pathogen will improve our knowledge of molecular mechanisms underlying host resistance and facilitate the development of resistant alfalfa cultivars. However, the intractable genetic system of cultivated alfalfa, owing to its tetrasomic inheritance and outcrossing nature, limits the ability to carry out genetic analysis in alfalfa. Nonetheless, the model legume Medicago truncatula, a close relative of alfalfa, provides a surrogate for cloning the counterparts of many agronomically important genes in …

The Role Of Spiders In The Detrital Food Web Of An Eastern Deciduous Forest, Erin Elizabeth Hladilek

University of Kentucky Doctoral Dissertations

Historically, terrestrial food web research has focused on describing the structure of aboveground grazing webs, and determining how interactions among plants, herbivores and higher trophic levels influence primary productivity. Detrital food webs however, play a significant role in regulation of ecosystem dynamics through direct impacts on decomposition. Unraveling the complex nature of detrital food web structure is critical to developing a better understanding of ecosystem function. Therefore the primary objective of this research was to describe the structure of the leaf-litter food web in a temperate deciduous forest, with emphasis on interactions between a community of generalist predators, the forest-floor …

Microbial Community Structure Dynamics In Ohio River Sediments During Reductive Dechlorination Of Pcbs, Andres Enrique Nunez

University of Kentucky Doctoral Dissertations

The entire stretch of the Ohio River is under fish consumption advisories due to contamination with polychlorinated biphenyls (PCBs). In this study, natural attenuation and biostimulation of PCBs and microbial communities responsible for PCB transformations were investigated in Ohio River sediments.

Natural attenuation of PCBs was negligible in sediments, which was likely attributed to low temperature conditions during most of the year, as well as low amounts of available nitrogen, phosphorus, and organic carbon. Moreover, surface sediments were relatively oxidized, as indicated by the prevalence of aerobic bacteria such as beta- Proteobacteria, alpha-Proteobacteria, Sphingobacteria, and Nitrospira in 16S rRNA sediment …

Influences Of Host Size And Host Quality On Host Use In A Seed-Feeding Beetle, Angela Rocío Amarillo-Suárez

University of Kentucky Doctoral Dissertations

For insects that develop inside discrete hosts both host size and host quality constrain offspring growth, influencing the evolution of body size and life history traits. This dissertation examines the effects of host size, host quality, and intraspecific competition on life history and associated traits of populations of the seed-feeding beetle S. limbatus adapted to different host plants, and quantifies population differences in phenotypic plasticity. Populations of the study correspond to divergent clades of the species phylogeography (Colombia and United States).

Clades compared differ genetically for all traits when beetles were raised in a common garden. Contrary to expectations from …

Localization Of Diplodia Pinea In Diseased And Latently-Infected Pinus Nigra, Jennifer Lee Flowers

University of Kentucky Doctoral Dissertations

Diplodia pinea causes Diplodia tip blight on more than 30 different pine species. During the past 10 years, Diplodia tip blight has emerged as a serious problem in landscape and Christmas tree farms in this region. Surveys of diseased and symptomless Austrian pines revealed that latent infections of symptomless shoots by D. pinea were common. Latent infections may account for the recently observed rapid decline of mildly diseased pines in our region. To investigate the colonization habits of D. pinea within its host, molecular cytology was attempted and traditional histology was performed on naturally infected, diseased and asymptomatic Austrian pine …

Loline Alkaloid Biosynthesis In Neotyphodium Uncinatum, A Fungal Endophyte Of Lolium Pratense, Jimmy Douglas Blankenship

University of Kentucky Doctoral Dissertations

Some endophytes in mutualistic associations with Festuca, Lolium and other grass species produce insecticidal loline alkaloids (1-aminopyrrolizidines; LA). These loline alkaloids have a saturated pyrrolizidine ring system (two-rings sharing a carbon and nitrogen atom), a 1-amine substituted with methyl, acetyl, or formyl groups, and an oxygen bridge between C-2 and C-7. The development of a reliable system of production of LA in cultures of the Lolium pratense (meadow fescue) endophyte, Neotyphodium uncinatum, facilitated work on the LA biosynthetic pathway. N. uncinatum produced norloline, loline, methylloline, N-acetylnorloline (NANL), N-formylloline (NFL), and N-acetylloline as detected in culture filtrates. The total production …