Digital Commons Network^™

Identification Of The Western Tarnished Plant Bug (Lygus Hesperus) Olfactory Co-Receptor Orco: Expression Profile And Confirmation Of Atypical Membrane Topology, J. Joe Hull, Eric J. Hoffmann, Omaththage P. Perera, Gordon L. Snodgrass

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Lygus hesperus (western tarnished plant bug) is an agronomically important pest species of numerous cropping systems. Similar to other insects, a critical component underlying behaviors is the perception and discrimination of olfactory cues. Consequently, the molecular basis of olfaction in this species is of interest. To begin to address this issue, we utilized homology-based PCR as a commonly accepted abbreviation but if necessary it is polymerase chain reaction methods to identify the L. hesperus olfactory receptor co-receptor (Orco) ortholog, a receptor that has been shown to be essential for olfaction. The L. hesperus Orco (LhOrco) shares significant sequence homology with …

Chemical Optimization Of Protein Extraction From Sweet Potato (Ipomoea Batatas) Peel, Katherine P. Maloney, Van-Den Truong, Jonathan C. Allen

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Proteins isolated from sweet potatoes (Ipomoea batatas) have been shown to possess antidiabetic, antioxidant, and antiproliferative properties. The objective of this study was to chemically optimize a process for extracting proteins from sweet potato peel. The extraction procedure involved mixing peel with saline solvent to dissolve proteins and then precipitating with CaCl₂. Quadratic and segmented models were used to determine the optimum NaCl concentration and peel to solvent ratio to maximize protein solubility while minimizing solvent usage. A segmented model was also used to optimize the concentration of CaCl2 used for precipitation. The highest yield was …

Responses To Varroa Destructor And Nosema Ceranae By Several Commercial Strains Of Australian And North American Honeybees (Hymenoptera: Apidae), Thomas E. Rinderer, Benjamin P. Oldroyd, Amanda M. Frake, Lilia I. De Guzman, Lelania Bourgeois

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

The potential impact of varroa (Varroa destructor, Anderson & Trueman) on Australian beekeeping and agriculture depends in part on the levels of resistance to this parasite expressed by Australian commercial honeybees (Apis mellifera). The responses of seven lines of Australian honeybees to V. destructor were compared with the responses of a stock of Italian honeybees from the United States known for its susceptibility to V. destructor and two stocks known for their resistance to V. destructor, Russian honeybees (RHB) and a stock expressing the varroa sensitive hygiene trait (VSH). The experiment began in May with …

A Deleterious Effect Associated With Unh159 Is Attenuated In Twin Embryos Of An Inbred Line Of Blue Tilapia Oreochromis Aureus, A. Shirak, Yniv Palti, O. Bern, Thomas D. Kocher, Elisha Gootwine, Eyal Seroussi, Gideon Hulata, Micha Ron, Ramy R. Avtalion

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Offspring of a highly inbred gynogenetic line of Oreochromis aureus displayed 12-fold increase in twinning rate compared to the outbred population. Asymmetric conjoined twins, which consist of a normal embryo attached to a malformed-atrophic twin, were frequently encountered in both gynogenetic (90·7%) and outbred (38·2%) embryos. The monozygotic origin of these twins was determined using five microsatellite markers. Progeny of heterozygous parents for the microsatellite UNH159 were separated into sub-sets of twins and normal full-sibs. Consistent with previous reports, the normal embryo sub-set exhibited elimination of both types of homozygotes for the UNH159 genetic marker at 2–8 days after fertilization. …

Aerosol Delivery Of Trail Pheromone Disrupts The Foraging Of The Red Imported Fire Ant, Solenopsis Invicta, David Maxwell Suckling, Lloyd D. Stringer, Joshua E. Corn, Barry Bunn, Ashraf M. El-Sayed, Robert K. Vander Meer

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

BACKGROUND: The fire ant, Solenopsis invicta, is one of the most aggressive and invasive species in the world. The trail pheromone Z,E-α-farnesene (91% purity)was prepared, and disruption of worker trail orientation was tested using an ethanol based aerosol formulation presenting a single puff of this compound by airbrush and compressed air. Trail-following behavior was recorded by overhead webcam and ants digitized before and after presentation of the aerosol treatment at four rates (1.6, 16, 160 and 1600 ng cm⁻²).

RESULTS: Ants preferred 110 ng cm⁻¹ over 11, 1.1 and 0.11 ng cm^{−1 …}

Distribution And Properties Of Soft Weathered Bedrock At ≤ 1m Depth In The Contiguous United States, Jonathan A. Wald, Robert C. Graham, Phillip J. Schoeneberger

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

The weathered bedrock zone is increasingly recognized as an important part of ecological and hydrologic systems, but its distribution is poorly known in the contiguous United States. We used spatial and laboratory characterization data from the United States Department of Agriculture (USDA)-Natural Resources Conservation Service to assess the distribution and soil-like properties of soft weathered bedrock (saprock and saprolite) within the 48 contiguous United States. Because USDA soil inventories generally do not extend below 2m, and because the upper 1m is clearly involved in ecosystem function and vadose zone hydrology, we restricted our inquiry to soft weathered bedrock within 1m …

Evaporative Loss From Irrigated Interrows In A Highly Advective Semi-Arid Agricultural Area, Nurit Agam, Steven R. Evett, Judy A. Tolk, William P. Kustas, Paul D. Colaizzi, Joseph G. Alfieri, Lynn G. Mckee, Karen S. Copeland, Terry A. Howell, Jose L. Chávez

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Agricultural productivity has increased in the Texas High Plains at the cost of declining water tables, putting at risk the sustainability of the Ogallala Aquifer as a principal source of water for irrigated agriculture. This has led area producers to seek alternative practices that can increase water use efficiency (WUE) through more careful management of water. One potential way of improving WUE is by reducing soil evaporation (E), thus reducing overall evapotranspiration (ET). Before searching for ways to reduce E, it is first important to quantify E and understand the factors that determine its magnitude. The objectives of …

Degree Of Woody Encroachment Into Grasslands Controls Soil Carbohydrate And Amino Compound Changes During Long Term Laboratory Incubation, Courtney A. Creamer, Timothy R. Filley, Dan C. Olk, Alain Plante, Clément Peltre, Sara M. Top, Thomas W. Boutton

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Up to 50% of organic C and 80% of organic N within soil can exist as amino acids, amino sugars and carbohydrates. To determine how potential microbial accessibility and turnover of these compounds is impacted by encroachment of woody plants into grasslands, we investigated changes in evolved CO₂ during thermal analysis and in carbohydrate and amino compound chemistry after long term laboratory incubation of sandy loam grassland woodland soils from southern Texas, USA. Thermal analysis showed that incubation increased the amount of soil organic matter (SOM) released at higher temperatures and that evolved CO₂ profiles correlated with increases …

Early Weaning In Northern Great Plains Beef Cattle Production Systems: Ii. Development Of Replacement Heifers Weaned At 80 Or 215 D Of Age, R.C. Waterman, T.W. Geary, J.A. Paterson, R.J. Lipsey

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Studies were conducted to evaluate effects of weaning and subsequent heifer development treatments within two herds located in the Northern Great Plains, USA. Heifer calves from predominantly Angus x Hereford dams were stratified within damage and calving date (Fort Keogh Livestock and Range Research Laboratory (LARRL), Miles City, MT, USA; n=328) and randomly assigned within study and strata to one of three weaning treatments. Heifer calves from Angus and Angus x Simmental dams (n=167; Judith Gap (JG),MT,USA) were stratified within breed group by age, calving date, and AI sire. Heifer calves either remained with their dams until …

Climate Suitability And Human Influences Combined Explain The Range Expansion Of An Invasive Horticultural Plant, Carolyn M. Beans, Francis F. Kilkenny, Laura F. Galloway

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Ecological niche models are commonly used to identify regions at risk of species invasions. Relying on climate alone may limit a model’s success when additional variables contribute to invasion. While a climate-based model may predict the future spread of an invasive plant, we hypothesized that a model that combined climate with human influences would most successfully explain its present distribution.Weused the ecological niche model MaxEnt to test our hypothesis with Japanese honeysuckle (Lonicera japonica), a common invasive horticultural plant in the United States.We first predicted the future range expansion of the species in the United States using a …

Mixed-Grass Prairie Canopy Structure And Spectral Reflectance Vary With Topographic Position, Rebecca L. Phillips, Moffatt K. Ngugi, John Hendrickson, Aaron Smith, Mark West

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Managers of the nearly 0.5 million ha of public lands in North and South Dakota, USA rely heavily on manual measurements of canopy height in autumn to ensure conservation of grassland structure for wildlife and forage for livestock. However, more comprehensive assessment of vegetation structure could be achieved for mixed-grass prairie by integrating field survey, topographic position (summit, mid and toeslope) and spectral reflectance data. Thus, we examined the variation of mixed-grass prairie structural attributes (canopy leaf area, standing crop mass, canopy height, nitrogen, and water content) and spectral vegetation indices (VIs) with variation in topographic position at the Grand …

Switchgrass Pvicad1: Understanding Residues Important For Substrate Preferences And Activity, Aaron J. Saathoff, Mark S. Hargrove, Eric J. Haas, Christian M. Tobias, Paul Twigg, Scott Sattler, Gautam Sarath

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Cinnamyl alcohol dehydrogenase (CAD) catalyzes the final step in monolignol biosynthesis. Although plants contain numerous genes coding for CADs, only one or two CADs appear to have a primary physiological role in lignin biosynthesis. Much of this distinction appears to reside in a few key residues that permit reasonable catalytic rates on monolignal substrates. Here, several mutant proteins were generated using switchgrass wild type (WT) PviCAD1 as a template to understand the role of some of these key residues, including a proton shuttling HL duo in the active site. Mutated proteins displayed lowered or limited activity on cinnamylaldehydes and exhibited …

Chapter 1: The Evolution Of Switchgrass As An Energy Crop, David J. Parrish, Michael D. Casler, Andrea Monti

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

This chapter discusses the prehistoric origins of switchgrass, its mid-twentieth century adoption as a crop, and late-twentieth century efforts to develop it into an energy crop. The species probably first appeared about 2 million years ago (MYA) and has continued to evolve since, producing two distinct ecotypes and widely varying ploidy levels. We build the case that all existing switchgrass lineages must be descended from plants that survived the most recent glaciation of North America and then, in just 11,000 years, re-colonized the eastern two-thirds of the continent. Moving to historic times, we discuss how switchgrass was first considered as …

Soil Quality Improvement Under An Ecologically Based Farming System In Northwest Missouri, Robert J. Kremer, Linda F. Hezel

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Ecologically based farming conserves and improves the soil resource and protects environmental quality by using organic or natural resources without the application of synthetic chemicals. Soil quality assessment indicates the ability of management systems to optimize soil productivity and to maintain its structural and biological integrity. Our objective was to evaluate the effect of ecologically based management on biochemical characteristics of soil [soil quality indicators (SQI)] as an assessment of soil quality. The study was conducted on an ecologically based farming enterprise established on gently sloping soils of Sharpsburg silt loam (fine montmorillonitic, mesic Typic Argiudolls) in Clay County, Missouri, …

Tree Size But Not Forest Basal Area Influences Ant Colony Response To Disturbance In A Neotropical Ant–Plant Association, Thomas S. Davis, Nathaniel E. Foote, Kevin C. Grady

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Ant–acacia mutualisms are conspicuous biotic associations in Savannah and neotropical ecosystems; however, the effects of tree size and forest structure on ant behaviour and tree traits are rarely examined. We tested two hypotheses related to these effects: (1) ant responses to disturbance are influenced by tree size and forest basal area; and (2) tree traits important to ants are predictable by tree size and forest basal area. We investigated these hypotheses in a dry tropical forest (Ometepe Island, Nicaragua) with the myrmecophytic Collins acacia (Vachellia collinsii Saff.) and the ant Pseudomyrmex spinicola (Emery 1890). We measured trees from three …

Fum And Bik Gene Expression Contribute To Describe Fumonisin And Bikaverin Synthesis In Fusarium Verticillioides, I. Lazzaro, M. Busman, P. Battilani, R. A. E. Butchko

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Fusarium verticillioides is a maize pathogen that produces toxic secondary metabolites, including fumonisins and bikaverin. The regulation of biosynthetic gene expression and the production of these metabolites are not fully understood and in this study we investigated the influence of water activity (0.955 and 0.990) on the expression of 5 genes (FUM3–FUM8–FUM13–FUM14 and BIK1) in F. verticillioides strains after 14 and 21 days incubation. Fumonisin production and biosynthetic gene expression were greatest at a_w=0.990, and the same trend was observed for bikaverin production, and BIK1 expression. FUM3 and FUM14 were the most highly expressed genes and …

Identification Of Gene Clusters Associated With Fusaric Acid, Fusarin, And Perithecial Pigment Production In Fusarium Verticillioides, Daren W. Brown, Robert A. E. Butchko, Mark Busman, Robert H. Proctor

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

The genus Fusarium is of concern to agricultural production and food/feed safety because of its ability to cause crop disease and to produce mycotoxins. Understanding the genetic basis for production of mycotoxins and other secondary metabolites (SMs) has the potential to limit crop disease and mycotoxin contamination. In fungi, SM biosynthetic genes are typically located adjacent to one another in clusters of coexpressed genes. Such clusters typically include a core gene, responsible for synthesis of an initial chemical, and several genes responsible for chemical modifications, transport, and/or regulation. Fusarium verticillioides is one of the most common pathogens of maize and …

Surfactant-Free Hybridization Of Transition Metal Oxide Nanoparticles With Conductive Graphene For High-Performance Supercapacitor, Wen Qian, Zhiqiang Chen, Steven Cottingham, William Alexander Merrill, Natasja A. Swartz, Andrea Goforth, Tami Lasseter Clare, Jun Jiao

Chemistry Faculty Publications and Presentations

In order to improve specific capacitance and limit electrical resistance, high-quality exfoliatedgraphene decorated with transition metal (Fe, Mn, Co) oxide nanoparticles (NPs) has been successfully synthesized without the use of surfactant via a simple, general, environmentally-friendly chemical process. The specific capacitance of as-prepared graphene/Mn₃O₄ composite reach 239.6 F/g, when employed as the anode material in neutral NaCl electrolyte solutions (cf. 98.2 F/g for pristine graphene and 141.4 F/g for pure Mn₃O₄ NPs), which indicate the synergetic effects from both graphene and attached Mn₃O₄ NPs. Moreover, the high conductivity of …

Diversity Of Archaeosine Synthesis In Crenarchaeota, Gabriela Phillips, Manal A. Swairjo, Kirk W. Gaston, Marc Bailly, Patrick A. Limbach, Dirk Iwata-Reuyl, Valérie De Crécy-Lagard

Chemistry Faculty Publications and Presentations

Archaeosine (G+) is found at position 15 of many archaeal tRNAs. In Euryarchaeota, the G+ precursor, 7-cyano-7-deazaguanine (preQ0), is inserted into tRNA by tRNA-guanine transglycosylase (arcTGT) before conversion into G+ by ARChaeosine Synthase (ArcS). However, many Crenarchaeota known to harbor G+ lack ArcS homologs. Using comparative genomics approaches, two families that could functionally replace ArcS in these organisms were identified: 1) GAT-QueC, a two-domain family with an N-terminal glutamine amidotransferase class-II domain fused to a domain homologous to QueC, the enzyme that produces preQ0; 2) QueF-like, a family homologous to the bacterial enzyme catalyzing the reduction of preQ0 to 7- …

Trait Convergence And Plasticity Among Native And Invasive Species In Resource-Poor Environments, Rebecca E. Drenovsky, Albina Khasanova, Jeremy J. James

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Premise of study: Functional trait comparisons provide a framework with which to assess invasion and invasion resistance. However, recent studies have found evidence for both trait convergence and divergence among coexisting dominant native and invasive species. Few studies have assessed how multiple stresses constrain trait values and plasticity, and no study has included direct measurements of nutrient conservation traits, which are critical to plants growing in low-resource environments.

Methods: We evaluated how nutrient and water stresses affect growth and allocation, water potential and gas exchange, and nitrogen (N) allocation and use traits among a suite of six codominant species from …

Modifying Crops To Increase Cell Wall Digestibility, Hans-Joachim G. Jung, Deborah A. Samac, Gautam Sarath

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Improving digestibility of roughage cell walls will improve ruminant animal performance and reduce loss of nutrients to the environment. The main digestibility impediment for dicotyledonous plants is highly lignified secondary cell walls, notably in stem secondary xylem, which become almost non-digestible. Digestibility of grasses is slowed severely by lignification of most tissues, but these cell walls remain largely digestible. Cell wall lignification creates an access barrier to potentially digestible wall material by rumen bacteria if cells have not been physically ruptured. Traditional breeding has focused on increasing total dry matter digestibility rather than cell wall digestibility, which has resulted in …

Analysis Of Off-Grid Hybrid Wind Turbine/Solar Pv Water Pumping Systems, Brian D. Vick, Byron A. Neal

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

While many remote water pumping systems exist (e.g. mechanical windmills, solar photovoltaic, wind-electric, diesel powered), few combine both the wind and solar energy resources to possibly improve the reliability and the performance of the system. In this paper, off-grid wind turbine (WT) and solar photovoltaic (PV) array water pumping systems were analyzed individually and combined as a hybrid system. The objectives were to determine: (1) advantages or disadvantages of using a hybrid system over using a WT or a solar PV array alone; (2) if the WT or solar PV array interfered with the output of the other; and (3) …

First Report Of Strobilurin Resistance In Cercospora Beticola In Sugar Beet (Beta Vulgaris) In Michigan And Nebraska, Usa, W.W. Kirk, L.E. Hanson, G.D. Franc, W.L. Stump, E. Gachango, G. Clark, J. Stewart

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Cercospora leaf spot (CLS) caused by Cercospora beticola Sacc. is the most important foliar disease of sugar beet (Beta vulgaris) worldwide (Jacobsen & Franc, 2009). CLS is controlled mainly with fungicides, including strobilurins (FRAC group 11). Resistance to strobilurins in C. beticola has not been reported in the field (Secor et al., 2010) but insensitive mutations have been artificially developed (Malandrakis et al., 2011). In 2011, fields from several areas in Michigan, USA treated with strobilurins had severe CLS and diminished control was also noted in small plot trials (Fig. 1). Individual leaf spot lesions were sampled from …

Nuisance Flies On Australian Cattle Feedlots: Immature Populations, Jerome Hogsette, R. Urech, P.E. Green, A. Skerman, M.M. Elson-Harris, R.L. Bright, G.W. Brown

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Species composition, seasonality and distribution of immature fly populations on a southern Queensland feedlot during 2001–2003 were determined. Similar data were collected on feedlots in central New South Wales and central Queensland. The fly species recovered in the highest numbers were Musca domestica L. (Diptera: Muscidae), Stomoxys calcitrans L. (Diptera: Muscidae) and Physiphora clausa Macquart (Diptera: Ulidiidae). Houseflies were the dominant species at all feedlots. Houseflies preferred the warmer months from October to June, but stable flies preferred the cooler months and peaked in spring (September–November) and autumn (March–May). Larval abundance ratings recorded in the feedlot and numbers of larvae …

The Octopus Wrestler, J. S. Khan

Yalobusha Review

No abstract provided.

Volume 17 (2012): Complete Issue, Journal Editors

Yalobusha Review

No abstract provided.

Shifting Public Health Priorities And The Global Effort To Prevent A Bird Flu Pandemic, Robert Gatter

All Faculty Scholarship

Global strategy to control highly pathogenic avian influenza (HPAI) has changed dramatically since 2003 when it was first reported that a confirmed bird flu jumped the species barrier to infect a human in Hong Kong. Evidence of this shift in priorities in the global fight against HPAI can be found most clearly in program funding trends. In late 2008 and into 2009, financial commitments from international donors for all HPAI programs dropped significantly. Meanwhile, within HPAI programs, funding shifted substantially away from animal biosecurity projects and into human response and preparedness work. This Article examines three reasons for this shift …

Barriers To Front Propagation In Ordered And Disordered Vortex Flows, Dylan Bargteil, Tom Solomon

Faculty Journal Articles

We present experiments on reactive front propagation in a two-dimensional (2D) vortex chain flow (both time-independent and time-periodic) and a 2D spatially disordered (time-independent) vortex-dominated flow. The flows are generated using magnetohydrodynamic forcing techniques, and the fronts are produced using the excitable, ferroin-catalyzed Belousov-Zhabotinsky chemical reaction. In both of these flows, front propagation is dominated by the presence of burning invariant manifolds (BIMs) that act as barriers, similar to invariant manifolds that dominate the transport of passive impurities. Convergence of the fronts onto these BIMs is shown experimentally for all of the flows studied. The BIMs are also shown to …

Sex Differences In Hookup Behavior: A Replication And Examination Of Parent-Child Relationship Quality, T. Joel Wade

Faculty Journal Articles

In the current research, we assessed the impact of parent-child relationships on attitudes toward, and engagement in, hookup behaviors using a sample of 407 college students. Based on prior research, it was hypothesized that heterosexual participants, especially women, who do not perceive themselves as having a strong, close, positive relationship with their opposite-sex parent would be more likely to engage in or attempt to engage in casual sexual behavior (hookups). Also, men were expected to be more satisfied with, and more in agreement with, hookup behavior than women. The results were partially consistent with the hypotheses. Men were more satisfied …

Age As A Factor In Inter-Tissue Spacing Of Stable Carbon Isotope Values In Juvenile Human Remains From The Dakhleh Oasis, Egypt, Annie Laurie Norris

Electronic Theses and Dissertations

Although stable isotope analysis is routinely utilized in bioarchaeology and relies on principles that are well-understood, there are still fundamental issues that have not been thoroughly investigated. This thesis examines the relationship between inter-tissue spacing of carbon stable isotope values (δ13C) and age in juvenile human remains. Analyses of tissues within the same individual reveal disparate isotopic values for a variety of physiological and biological reasons discussed herein. This project examines the distance between the δ13C values in bone collagen, skin, hair, and nail, and examines how these distances vary between different age groups, utilizing data collected from 52 well-preserved …