Life Sciences Commons^™

Effect Of Nitrogen Fertilizer Rate And Harvest Season On Forage Yield, Quality, And Macronutrient Concentrations In Midland Bermuda Grass, Maru K. Kering, John A. Guretzky, Eddie Funderburg, Jagadeesh Mosali

Department of Agronomy and Horticulture: Faculty Publications

Bermuda grass [Cynodon dactylon (L.) Pers.] is a major forage for grazing and hay production in the southern United States. The objectives of this study were to determine effects of nitrogen (N) fertilization rate (0, 112, 224, 336, and 448 kg ha⁻¹), split spring and summer applications of N at the 224 and 448 kg ha⁻¹ rates, and harvest periods (spring and summer) on forage yield, crude protein (CP), acid detergent fiber (ADF), neutral detergent fiber (NDF), total digestible nutrients (TDN), and concentrations of phosphorus (P), potassium (K), magnesium (Mg), and calcium (Ca) in Midland Bermuda …

Switchgrass For Forage And Bioenergy: Harvest And Nitrogen Rate Effects On Biomass Yields And Nutrient Composition, John A. Guretzky, Jon T. Biermacher, Billy Cook, Maru K. Kering, Jagadeesh Mosali

Department of Agronomy and Horticulture: Faculty Publications

Switchgrass (Panicum virgatum L.) may have value as forage and a bioenergy feedstock. Our objective was to evaluate how harvest system and N fertilizer rates affected biomass yield and nutrient composition of young stands of switchgrass (cv. Alamo) in the southern Great Plains, USA. Nitrogen fertilization increased biomass yields from 10.4, 10.8, and 12.2 Mg ha⁻¹ at 0 kg N ha⁻¹ to 13.7, 14.6, and 21.0 Mg ha⁻¹ at 225 kg N ha⁻¹ when harvested after seed set (October), after frost (December), and twice per year after boot stage (July) and frost, respectively. Nutrient concentrations …

Learning Gains And Response To Digital Lessons On Soil Genesis And Development, Martha Mamo, James A. Ippolito, Timothy A. Kettler, Ronald Reuter, Dennis L. Mccallister, Patricia Morner, Dann E. Husmann, Erin E. Blankenship

Department of Agronomy and Horticulture: Faculty Publications

Evolving computer technology is offering opportunities for new online approaches in teaching methods and delivery. Well-designed web-based (online) lessons should reinforce the critical need of the soil science discipline in today's food, energy, and environmental issues, as well as meet the needs of the diverse clientele with interest in agricultural and/ or environmental disciplines. The objectives of the project were to: (1) develop web-based lessons in soil genesis and development and (2) evaluate context-based case studies or application lessons (agronomic, environmental, and ecological situations) to teach soil genesis and development. Six principles lessons, along with three applications lessons, were developed …

High-Yield Irrigated Maize In The Western U.S. Corn Belt: Ii. Irrigation Management And Crop Water Productivity, Patricio Grassini, Haishun Yang, Suat Irmak, John Thorburn, Charles Burr, Kenneth G. Cassman

Department of Agronomy and Horticulture: Faculty Publications

Appropriate benchmarks for water productivity (WP), defined here as the amount of grain yield produced per unit of water supply, are needed to help identify and diagnose inefficiencies in crop production and water management in irrigated systems. Such analysis is lacking for maize in the Western U.S. Corn Belt where irrigated production represents 58% of total maize output. The objective of this paper was to quantify WP and identify opportunities to increase it in irrigated maize systems of central Nebraska. In the present study, a benchmark for maize WP was (i) developed from relationships between simulated yield and seasonal water …

High-Yield Irrigated Maize In The Western U.S. Corn Belt: I. On-Farm Yield, Yield Potential, And Impact Of Agronomic Practices, Patricio Grassini, John Thorburn, Charles Burr, Kenneth Cassman

Department of Agronomy and Horticulture: Faculty Publications

Quantifying the exploitable gap between average farmer yields and yield potential (Y_P) is essential to prioritize research and formulate policies for food security at national and international levels. While irrigated maize accounts for 58% of total annual maize production in the Western U.S. Corn Belt, current yield gap in these systems has not been quantified. Our objectives were to quantify Y_P, yield gaps, and the impact of agronomic practices on both parameters in irrigated maize systems of central Nebraska. The analysis was based on a 3-y database with field-specific values for yield, applied irrigation, and N …

Registration Of ‘Anton’ Hard White Winter Wheat, Robert A. Graybosch, C. James Peterson, P. Stephen Baenziger, David D. Baltensperger, Lenis Alton Nelson, Yue Jin, James A. Kolmer, Bradford W. Seabourn, Brian S. Beecher

Department of Agronomy and Horticulture: Faculty Publications

Low levels of the grain enzyme polyphenol oxidase (PPO) are a necessary attribute of any newly developed hard white wheat (Triticum aestivum L.) adapted to the Great Plains. Low PPO correlates with enhanced end-use quality, including the fi nal product color in noodle applications. Few wheats with this necessary characteristic presently are available. The objective of this study was to develop a hard winter wheat adapted to the region that possesses both low levels of grain PPO and quality characteristics that would allow its utilization in domestic bread-making applications. This goal was achieved via the development and release in …

High Yield Corn Production Can Result In High Nitrogen Use Efficiency, Charles S. Wortmann, Charles A. Shapiro, Achim Dobermann, Richard B. Ferguson, Gary W. Hergert, Daniel Walters, David Tarkalson

Department of Agronomy and Horticulture: Faculty Publications

A team of University of Nebraska-Lincoln scientists, with partial funding from the Nebraska State Legislature, addressed this challenge. They conducted 32 irrigated trials across diverse production conditions of Nebraska from 2002 to 2004 to evaluate corn response to rates of split-applied N. The results were reported in two papers published in the January-February 2011 issue of Agronomy Journal.

The average maximum yield in these trials was 240 bu/A. When the previous crop was corn (CC) and soybean (CS), the respective mean yields with no N applied were 155 and 165 bu/A, and the mean grain yield increases to reach …

Biological Suppression Of Velvetleaf (Abutilon Theophrasti ) In An Eastern Nebraska Soil, Jane Okalebo, Gary Y. Yuen, Rhae A. Drijber, Erin E. Blankenship, Cafer Eken, John L. Lindquist

Department of Agronomy and Horticulture: Faculty Publications

Weed-suppressive soils contain naturally occurring microorganisms that suppress a weed by inhibiting its growth, development, and reproductive potential. Increased knowledge of microbe–weed interactions in such soils could lead to the identification of management practices that create or enhance soil suppressiveness to weeds. Velvetleaf death and growth suppression was observed in a research field (fieldA) that was planted with high populations of velvetleaf, which may have developed via microbial mediated plant–soil feedback. Greenhouse studies were conducted with soil collected from fieldA (soilA) to determine if it was biologically suppressive to velvetleaf. In one study, mortality of velvetleaf …

Corn And Velvetleaf (Abutilon Theophrasti ) Transpiration In Response To Drying Soil, Jared Schmidt, Erin E. Blankenship, John L. Lindquist

Department of Agronomy and Horticulture: Faculty Publications

Soil water availability is the most important factor limiting crop yield worldwide. Understanding crop and weed transpiration in response to water supply may provide valuable insight into the mechanisms of crop yield loss in water limited environments. A greenhouse experiment was conducted to quantify corn and velvetleaf transpiration in response to drying soil. Five plants of each species were well watered by adding back the equivalent water loss each day to reach field capacity, and five plants were subjected to drought stress (dry-down) by not replacing lost water. Normalized daily transpiration of dry-down plants was regressed on soil water content …

Computer Simulation Of A Hollow-Fiber Bioreactor: Heparan Regulated Growth Factors-Receptors Binding And Dissociation Analysis, Changjiang Zhang

University of Kentucky Doctoral Dissertations

This thesis demonstrates the use of numerical simulation in predicting the behavior of proteins in a flow environment.

A novel convection-diffusion-reaction computational model is first introduced to simulate fibroblast growth factor (FGF-2) binding to its receptor (FGFR) on cell surfaces and regulated by heparan sulfate proteoglycan (HSPG) under flow in a bioreactor. The model includes three parts: (1) the flow of medium using incompressible Navier-Stokes equations; (2) the mass transport of FGF-2 using convection-diffusion equations; and (3) the cell surface binding using chemical kinetics. The model consists of a set of coupled nonlinear partial differential equations (PDEs) for flow and …

The Absence Of Abcd2 Reveals A Novel Role For Peroxisomes In The Protection From Metabolic Syndrome, Jingjing Liu

University of Kentucky Doctoral Dissertations

ABCD2 (D2) is a peroxisomal ATP binding cassette (ABC) transporter that is expressed in brain, adrenal and liver. D2 is transcriptionally regulated by key transcriptional factors that control lipid and glucose metabolism. Therefore, we examined its role in adipose tissue. These studies revealed that D2 is highly abundant in adipose tissue and upregulated during adipogenesis. However, D2 deficiency does not affect either adipogenesis or lipid accumulation. An examination of the lipid profile of adipose tissue revealed the accumulation of C20 and C22 fatty acids in D2 deficient (D2‐/‐) mice. When challenged with a diet enriched in erucic acid (C22:1, 10% …

Beef Cattle Grazing Preference Of Tall Fescue As Affected By Endophyte, Herbert Troye Owens Iii

University of Kentucky Master's Theses

Many factors control, contribute to, stimulate and limit forage selection. It is apparent that cattle prefer certain cultivars compared to others. This study sought to test if cattle displayed preferences for certain cultivars over a two-year period in 2008 and 2009. Determining the effect of endophyte status on preference was another objective. Previous research showed rapid increase in the selection of preferred cultivars, i.e., diet learning. We attempted to replicate those results. Forty cultivars (34 tall fescue (Lolium arundinaceum (Schreb.) Darbysh.) cultivars), two festuloliums (Festuca pratensis x Lolium perenne), two meadow fescue (Lolium pratense) and one meadow …

Fabrication And Characterization Of Mesoscale Protein Patterns Using Atomic Force Microscopy (Afm), Pei Gao

University of Kentucky Doctoral Dissertations

A versatile AFM local oxidation lithography was developed for fabricating clean protein patterns ranging from nanometer to sub-millimeter scale on octadecyltrichlorosilane (OTS) layer of Si (100) wafer. This protein patterning method can generate bio-active protein pattern with a clean background without the need of the anti-fouling the surface or repetitive rinsing.

As a model system, lysozyme protein patterns were investigated through their binding reactions with antibodies and aptamers by AFM. Polyclonal anti-lysozyme antibodies and anti-lysozyme aptamer are found to preferentially bind to the lysozyme molecules on the edge of a protein pattern before their binding to the interior ones. It …

The Return Of The Black Bear To Eastern Kentucky: Conflict And Tolerance Between People And Wildlife, Hannah B. Harris

University of Kentucky Doctoral Dissertations

The black bear (Ursus americanus) has returned to Kentucky and is now part of a reproducing population in the southeastern Cumberland Mountain region. The broad objective of this project was to examine the interactions between people and bears, with the ultimate goal of improving bear management in a way that addresses stakeholder concerns. Using interviews of regional stakeholders, participant observation, and media reports collected between summer 2003 and fall 2006, I investigated how the presence of black bears in Harlan and Letcher counties in Kentucky has had an impact on area residents. I complemented this information with observations …

Role Of Lipids In Tombusvirus Replication, Monika Sharma

University of Kentucky Doctoral Dissertations

Positive-strand RNA virus group are the most abundant among viruses affecting plants and animals. To successfully achieve replication, these viruses usurp or co-opt host proteins. To facilitate the discovery of host factors involved in Tomato bushy stunt virus (TBSV), yeast has been developed as a surrogate model host. Genome-wide approaches covering 95% of yeast genes, has revealed approximately hundred factors that could affect virus replication. Among the identified host factors, there are fourteen yeast genes, which affect/regulate lipid metabolism of the host.

One of the identified host gene is ERG25, which is an important factor for sterol biosynthesis pathway, affecting …

Characterization Of G10h Promoter And Isolation Of Wrky Transcription Factors Involved In Catharanthus Terpenoid Indole Alkaloid Biosynthesis Pathway, Nitima Suttpanta

University of Kentucky Doctoral Dissertations

Catharanthus roseus produces a large array of terpenoid indole alkaloids (TIAs) that are an important source of natural or semi-synthetic anticancer drugs. Biosynthesis of TIAs is tissue-specific and induced by certain phytohormones and fungal elicitors, indicating the involvement of a complex transcriptional control network. However, the transcriptional regulation of the TIA pathway is poorly understood. This study reports the isolation and characterization of the G10H promoter and two WRKY transcription factors regulating TIA biosynthesis.

Geraniol 10-hydroxylase (G10H) controls the first committed step in the biosynthesis of terpenoid indole alkaloids (TIA). The C. roseus G10H promoter sequence was isolated by a …

Conceptualizing And Improving Red Wine Grape Cultivars Grown In Kentucky, Matthew Simson

University of Kentucky Master's Theses

Wine sensory attributes are associated with quality of wines. Cabernet Franc did not possess good coloration of its wine. Therefore, in the 2009 and 2010 growing seasons, studies including the sampling of four red wine grape cultivars from the end of flowering throughout the rest of the season and applying treatments to Cabernet Franc grapevines at veraison were commenced to address suitability and color enhancement, respectively. The study examining Cabernet Franc, Cabernet Sauvignon, Chambourcin, and Norton looked at sampling their grapes at two-week intervals from times post-flowering to understand the demands of each cultivar during key stages of berry development, …

Effects Of Midstory Removal On Black Oak (Quercus Velutina) And White Oak (Quercus Alba) Regeneration, David Lee Parrott

University of Kentucky Master's Theses

The formation of dense understories in eastern forests has created low light environments that hinder the development of advance oak reproduction. Studies have shown that a midstory removal can enhance these light conditions and promote the development of competitive oak seedlings. Previous studies have been primarily focused on oaks found on productive sites, and there is little knowledge of this treatment’s potential on intermediate sites and the typically associated oak species. This study investigates the seven-year effects of midstory removal on natural and underplanted white (Quercus alba L.) and black oak (Quercus velutina L.) reproduction, as …

Use Of Copper Sulfate To Control Haemonchus Contortus Infestation In Hampshire Ewes, Melinda Mallory Simpson

University of Kentucky Master's Theses

Two studies were conducted to evaluate the effectiveness of using copper sulfate (CuSO₄) as a drench in Hampshire ewes to control stomach worms (Haemonchus contortus).

A study was conducted to assess the effectiveness of CuSO₄ to control gastrointestinal nematodes (GIN) over a three year period. Ewes were FAMACHA scored, hematocrit evaluated for packed cell volume (PCV), and fecal egg counts (FEC) were determined from 2007 through 2009. Ewes received only CuSO₄ to control GIN. Ewes with FEC exceeding 6,000 eggs/g feces were drenched.

A separate study during the summer of 2008 assessed the potential …

Nozzle Type And Arrangement Alternatives For Improved Application Of Suckercides In Burley Tobacco (Nicotiana Tabacum L.), Beau Robert Neal

University of Kentucky Master's Theses

Maleic hydrazide (MH) applications have been standard practice for sucker control in burley tobacco (Nicotiana tabacum L.) production for the last half-century because it is relatively inexpensive, effective and easy to apply. Non-MH suckercides such as fatty alcohols and local systemics can be utilized to reduce or replace MH and lower undesirable residues in the cured leaf. The objective of this study was to evaluate various nozzle types and arrangements for efficiency to determine if sucker control with fatty alcohol could be consistently improved over the currently used TG3-5-3 arrangement, as well as examine sprayer positioning (center vs. off-center) …

The Effect Of A Physical Education Games Unit On Children’S Participation In Neighborhood Physical Activity, Beth Erin Eddy

University of Kentucky Master's Theses

Many strategies to increase children’s physical activity have been studied, noted and implemented. It is important that physical educators realize their role in increasing physical activity both in school and outside of school. In order to promote physical activity outside of school it is important to understand what types of physical activities in which children enjoy participating. This study manipulated specific games taught in physical education classes and then explored how many and what types of these activities were continued in out-of-school free play at home in the children’s neighborhood. The students’ activities increased after the intervention, especially the activities …

The Response Of Tall Fescue And Its Fungal Endophyte To Climate Change, Glade Blythe Brosi

University of Kentucky Master's Theses

Tall fescue is the most common cool-season grass in the eastern USA, with broad economic and ecological importance to the region. Tall fescue is known to associate with a fungal endophyte, Neotyphodium coenophialum, whose presence can decrease biotic and abiotic stress experienced by the plant. This thesis evaluates the response of tall fescue and the fungal endophyte symbiosis to predicted climate change. I participated in two multi-factor climate change projects where I investigated the response of tall fescue tissue chemistry and growth to various climate change factors. Endophyte-infected (E+) tall fescue had decreased alkaloid production under elevated CO_{2 …}

Small Mammal Populations In Switchgrass Stands Managed For Biomass Production Compared To Hay And Corn Fields In Kentucky, Laura Mary Jane Schwer

University of Kentucky Master's Theses

Switchgrass (Panicum virgatum), a native warm-season grass, has been investigated as a renewable energy crop that may provide viable wildlife habitat. This study investigated small mammal populations in switchgrass, hay, and corn to assess the relative habitat quality. Four, three-night trapping sessions were conducted at four locations in Kentucky using Sherman livetraps. Trapping occurred in spring (before first hay harvest), summer, fall (before switchgrass and corn harvest), and winter (post-harvest). Relative abundance of small mammals, calculated using a capture per unit effort index (per 100 trapnights), and mean taxonomic richness were used to compare habitats. Switchgrass had a …

Integrating Management Of Soil Nitrogen And Weeds, Samuel E. Wortman, Adam Davis, Brian J. Schutte, John L. Lindquist

Department of Agronomy and Horticulture: Faculty Publications

Knowledge of the soil nitrogen (N) supply and the N mineralization potential of the soil combined with an understanding of weed-crop competition in response to soil nutrient levels may be used to optimize N fertilizer rates to increase the competitive advantage of crop species. A greenhouse study (2006) and field studies (2007 to 2008) in Illinois and Nebraska were conducted to quantify the growth and interference of maize and velvetleaf in response to varying synthetic N fertilizer rates in soils with high and low N mineralization potential. Natural soils were classified as having ‘‘low mineralization potential’’ (LMP), while soils amended …

Mathematical Model To Assess The Relative Effectiveness Of Rift Valley Fever Countermeasures, Holly Gaff, Colleen Burgess, Jacqueline Jackson, Tianchan Niu, Yiannis Papelis, David Hartley

Biological Sciences Faculty Publications

Mathematical modeling of infectious diseases is increasingly used to explicate the mechanics of disease propagation, impact of controls, and sensitivity of countermeasures. The authors demonstrate use of a Rift Valley Fever (RVF) model to study efficacy of countermeasures to disease transmission parameters. RVF is a viral infectious disease that propagates through infected mosquitoes and primarily affects animals but also humans. Vaccines exist to protect against the disease but there is lack of data comparing efficacy of vaccination with alternative countermeasures such as managing mosquito population or destroying infected livestock. This paper presents a compartmentalized multispecies deterministic ordinary differential equation model …

Range Extension For The Dismal Swamp Southern Bog Lemming, Synaptomys Cooperi Helaletes, In Eastern Virginia, Robert K. Rose

Biological Sciences Faculty Publications

The distribution of the Dismal Swamp Southern Bog Lemming is extended to include three counties west of the Dismal Swamp in southeastern Virginia, long considered its only location in the state. Evidence of lemmings was detected at 10 of 27 survey sites, and confirmed by trapping at three of five sites, all dominated by herbaceous vegetation.

Classroom Manipulative To Engage Students In Mathematical Modeling Of Disease Spread: 1 + 1 = Achoo!, H. Gaff, M. Lyons, G. Watson

Biological Sciences Faculty Publications

Infectious diseases ranging from the common cold to cholera affect our society physically, emotionally, ecologically, and economically. Yet despite their importance and impact, there remains a lack of effective teaching materials for epidemiology and disease ecology in K-12, undergraduate, and graduate curricula [2]. To address this deficit, we've developed a classroom lesson with three instructional goals: (1) Familiarize students on basic concepts of infectious disease ecology; (2) Introduce students to a classic compartmental model and its applications in epidemiology; (3) Demonstrate the application and importance of mathematical modeling as a tool in biology. The instructional strategy uses a game-based mathematical …

Human Endogenous Retrovirus Transcription Profiles Of The Kidney And Kidney-Derived Cell Lines, Sonja Haupt, Michele Tisdale, Michelle Vincendeau, Mary Anne Clements, David T. Gauthier, Raymond Lance, O. John Demmes, Adriana Tuqueti-Neves, Elfriede Noessner, Christine Leib-Mösch, Alex D. Greenwood

Biological Sciences Faculty Publications

The human genome comprises approximately 8-9% of human endogenous retroviruses (HERVs) that are transcribed with tissue specificity. However, relatively few organs have been examined in detail for individual differences in HERV transcription pattern, nor have tissue-to-cell culture comparisons been frequently performed. Using an HERV-specific DNA microarray, a core HERV transcription profile was established for the human kidney comparing 10 tissue samples. This core represents HERV groups expressed uniformly or nearly so in non-tumour kidney tissue. The profiles obtained from non-tumour tissues were compared to 10 renal tumour tissues (renal cell carcinoma, RCC) derived from the same individuals and additionally, to …

A New Species Of The Subterranean Amphipod Crustacean Genus Stygobromus (Crangonyctidae) From A Cave In Nevada, Usa, Steven J. Taylor, John R. Holsinger

Biological Sciences Faculty Publications

Stygobromus albapinus, a new stygobiotic amphipod crustacean species in the family Crangonyctidae, is described from two pools in Model Cave in Great Basin National Park, White Pine County, Nevada, USA. The type specimens were collected on two different visits to the cave. The new species is assigned to the hubbsi group, bringing the number of described species in this group to 45, but many other provisionally recognized species assigned to this group remain undescribed. With exception of a single species from deep wells in southeastern Wisconsin, all other members of the hubbsi group are recorded from a wide variety …

Comparative Phylogeography Of The Coral Triangle And Implications For Marine Management, Kent E. Carpenter, Paul H. Barber, Eric D. Crandall, Maria Carmen A. Ablan-Lagman, Ambariyanto Ambariyanto, Gusti Ngurah Mahardika, B. Mabel Manjaji-Matsumoto, Marie Antonette Junio-Menez, Mudjekeewis D. Santos, Craig J. Starger, Abdul Hamid A. Toha

Biological Sciences Faculty Publications

Extreme concentration of marine biodiversity and exploitation of marine resources in the Coral Triangle pose challenges to biogeographers and resource managers. Comparative phylogeography provides a powerful tool to test biogeographic hypotheses evoked to explain species richness in the Coral Triangle. It can also be used to delineate management units for marine resources. After about a decade of phylogeographical studies, patterns for theCoral Triangle are emerging. Broad connectivity in some species support the notion that larvae have maintained gene flow among distant populations for long periods. Other phylogeographic patterns suggest vicariant events resulting from Pleistocene sea level fluctuations, which have, at …