Life Sciences Commons^™

Effects Of Common Forage Phenolic Acids On Escherichia Coli O157:H7 Viability In Bovine Feces, J. E. Wells, E. D. Berry, V.H. Varel

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

Ruminant animals are carriers of Escherichia coli O157:H7, and the transmission of E. coli O157:H7 from cattle to the environment and to humans is a concern. It is unclear if diet can influence the survivability of E. coliO157:H7 in the gastrointestinal system or in feces in the environment. Feces from cattle fed bromegrass hay or corn silage diets were inoculated with E. coliO157:H7, and the survival of this pathogen was analyzed. When animals consumed bromegrass hay for <1 month, viable E. coliO157:H7 was not recovered after 28 days postinoculation, but when animals consumed the diet for >1 month, E. coli …

Loss Of Nitrate-Nitrogen By Runoff And Leaching For Agricultural Watersheds, M. A. Elrashidi, M. D. Mays, A. Fares, C. A. Seybold, J. L. Harder, S. D. Peaslee, Pam Vanneste

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

The loss of nutrients in runoff and leaching water from agricultural land is a major cause of poor water quality in the United States. Scientists (NRCS) developed a technique to estimate the impact of agricultural watersheds on natural water resources. The objectives were to apply the technique on Wagon Train (WT) watershed in Nebraska to predict: (i) loss of water by surface runoff and subsurface leaching, (ii) loss of nitrate-N from soils by runoff and leaching, and (iii) nitrate-N loading for WT reservoir. The annual loss of water was estimated at 4.32 million m³ for runoff and 0.98 million …

Comparison Of Glomalin And Humic Acid In Eight Native U.S. Soils, K. A. Nichols, S. F. Wright

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

Two important extractable fractions of soil organic matter (SOM) are humic acid (HA) and glomalin-related soil protein (glomalin). Optimizing the purity of each fraction is necessary to correlate fraction quantity and molecular characteristics with soil quality. Manipulation of extraction sequence and controlled precipitation of HA were used to evaluate co-extraction of HA and glomalin. Eight bulk soil samples (0 to 10 cm depth) were collected from four U.S. states (Colorado, Nebraska, Maryland, and Georgia). In Experiment 1, glomalin extraction (50 mM citrate, pH 8.0, at 121 'C) was followed by HA extraction (0.1 N NaOH at room temperature), and Experiment …

Developmental Sequences For Simulating Crop Phenology For Water-Limiting Conditions, Gregory S. Mcmaster, Wally Wilhelm, A. B. Frank

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

The timing, duration, and pace of developmental events, or phenology, are among the many responses of plants to limited soil water. Understanding and predicting plant responses to availability of soil water are important in improving the efficacy of management practices. However, the first steps towards gaining this understanding, summarizing the complete developmental sequence of the shoot apex and correlating the timing of these events, have rarely been reported. Also, the effect of water-limiting conditions on crop phenology and shoot apex development is variable. The objective of this paper is to present the developmental sequence of the wheat (Triticum aestivum …

Insect Trap: United States Patent, Hogsette Et Al.- November 2005, Jerome Hogsette, David Carlson

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

A safe, indoor trapping device for trapping and killing flying insects can be used in areas containing food, containing animals, for food preparation, etc. The device includes at least one removable trap body, a toxicant panel, and an insect collector.

Corn Stalk Nitrate Concentration Profile, Wally Wilhelm, Gary E. Varvel, James S. Schepers

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

The end-of-season stalk nitrate test provides a method of assessing the N available to the corn (Zea mays L.) crop during the latter part of the season. This study was conducted to determine how stalk nitrate test results and interpretations are affected by sample composition. Stalks were collected from three field sites and separated into phytomers (node plus internode above), which were subdivided into three or five segments after length was measured. Nitrate-N concentration of phytomers decreased linearly from the soil to the ear. Within a phytomer, segments also decreased acropetally (from base to apex). Node tissue NO_{3 …}

Corn Stalk Nitrate Concentration Profile, W. Wilhelm, G. E. Varvel, J. S. Schepers

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

The end-of-season nitrate test provides a method of assessing the N available to the corn (Zea mays L.) crop during the latter part of the season. This study was conducted to determine how stalk nitrate test results and interpretations are affected by sample composition. Stalks were collected from three filed sites and separated into phytomers (node plus internode above), which were subdivided into three or five segments after length was measured. Nitrate-N concentration of phytomers decreased linearly from the soil to the ear. Within a phytomer, segments also decreased acropetally (from base to apex). Node tissue NO₃-N …

Managing Yaupon With Fire And Herbicides In The Texas Post Oak Savannah, Rob B. Mitchell, James C. Cathey, Brad Dabbert, Ron Sosebee, Dale F. Prochaska, Stephanie Dupree

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

The Post Oak Savannah Ecological Region in Texas was once an open grassland savannah maintained by periodic fires. The Post Oak Savannah can support mid- and tall grasses, such as little bluestem, indiangrass, Texas wintergrass, and purpletop. Today, the savannahs have been replaced by oak woodlands with dense yaupon (Ilex vomitoria) understories that limit grass and forb production and species diversity (Fig. 1). Restriction of fires in conjunction with poor grazing management and periodic droughts are often credited for the dense thickets that occur in the Post Oak Savannah.

Yaupon is a native component of the Post Oak …

Characterization Of Waxy Grain Sorghum Lines In Relation To Granule-Bound Starch Synthase, J. F. Pedersen, S. R. Bean, R. A. Graybosch, S. H. Park, M. Tilley

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

The waxy phenotype, associated with endosperm containing little or no amylose, has been recognized in sorghum (Sorghum bicolor L. Moench) since 1933. Although variants of the waxy gene are well characterized in other cereals, the waxy trait has been assumed to be controlled by a single allele, wx, in sorghum. Recent improvements in technologies encourage re-examination of the waxy sorghums. The objectives of this research were therefore to identify and characterize sorghum lines with differing waxy alleles and to describe the actions of those alleles in crosses. Grain of eight waxy sorghum lines (BTxARG1, BTx630, Tx2907, B.9307, 94C274, …

Biotinylation Of K12 In Histone H4 Decreases In Response To Dna Double-Strand Breaks In Human Jar Choriocarcinoma Cells1,2, Nagarama Kothapalli, Gautam Sarath, Janos Zempleni

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

We tested the hypothesis that biotinylation of K12 in histone H4 plays a role in the cellular response to double-strand breaks (DSB) of DNA in human cells. DSB were caused by treating choriocarcinoma JAr cells with etoposide. Biotinylation of K12 in histone H4 decreased by 50% as early as 10–20 min after initiation of treatment with etoposide. Biotinylation returned to initial levels 30–40 min after the addition of etoposide to the medium. Temporal patterns of K12-biotinylation were similar for human lymphoma cells. Phosphorylation of S14 of histone H2B and poly(ADP-ribosylation) of glutamate residues on histone H2A are known markers of …

Analysis Of Expressed Sequence Tags And The Identification Of Associated Short Tandem Repeats In Switchgrass, Christian M. Tobias, Paul Twigg, Daniel M. Hayden, Kenneth P. Vogel, Robert B. Mitchell, Gerard R. Lazo, Elaine K. Chow, Gautam Sarath

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

Switchgrass is a large, North American, perennial grass that is being evaluated as a potential energy crop. Expressed sequence tags (ESTs) were generated from four switchgrass cv. ‘‘Kanlow’’ cDNA libraries to create a gene inventory of 7,810 unique gene clusters from a total of 11,990 individual sequences. Blast similarity searches to SwissProt and GenBank non-redundant protein and nucleotide databases were performed and a total of 79% of these unique clusters were found to be similar to existing protein or nucleotide sequences. Tentative functional classification of 61% of the sequences was possible by association with appropriate gene ontology descriptors. Significant differential …

Portable Probes To Measure Electrical Conductivity And Soil Quality In The Field, S.L. Arnold, John W. Doran, James S. Schepers, Brian J. Wienhold, Daniel Ginting, Brigid Amos, S. Gomes

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

Soil electrical conductivity (EC) is a useful indicator in managing agricultural systems, but tools for convenient and inexpensive measurements in the field are generally lacking. Handheld conductivity probes were designed to evaluate in-field naturally occurring and human-induced total soluble electrolyte levels in soil and water. The probes were used to survey and monitor EC in the field and to assess soil and water quality as related to environmental stability and sustainable food production. A pencil-sized 16-cm probe (PP) was connected to a handheld Hanna (DiST WP 4) conductivity meter, resulting in an economical, compact, and easy to use device. The …

K4, K9 And K18 In Human Histone H3 Are Targets For Biotinylation By Biotinidase, Kenya A. Kobza, Gabriela Camporeale, Brian Rueckert, Alice Kueh, Jacob B. Griffin, Gautam Sarath, Janos Zempleni

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

Histones are modified post-translationally, e.g. by methylation of lysine and arginine residues, and by phosphorylation of serine residues. These modifications regulate processes such as gene expression, DNA repair, and mitosis and meiosis. Recently, evidence has been provided that histones are also modified by covalent binding of the vitamin biotin. The aims of this study were to identify biotinylation sites in histone H3, and to investigate the crosstalk among histone biotinylation, methylation and phosphorylation. Synthetic peptides based on the sequence of human histone H3 were used as substrates for enzymatic biotinylation by biotinidase; biotin in peptides was probed using streptavidin peroxidase. …

Molecular Serotyping Of Escherichia Coli O26:H11, Lisa M. Durso, James L. Bono, James E. Keen

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

Serotyping is the foundation of pathogenic E. coli diagnostics; however, few laboratories have this capacity. We developed a molecular serotyping protocol that targets, genetically, the same somatic and flagellar antigens of E. coli O26:H11 used in traditional serotyping. It correctly serotypes strains untypeable by traditional methods, affording primary laboratories serotyping capabilities.

Evaluating Modeling Techniques For Cattle Heat Stress Prediction, T. M. Brown-Brandl, David D. Jones, Wayne Woldt

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

Researchers have traditionally predicted animal responses by means of statistical models. This study was conducted to evaluate modeling techniques. One hundred and twenty-eight feedlot heifers were observed during a 2-month period during the summer of 2002. Respiration rate and surface temperature were taken on a random sample of 40 animals twice a day. Five different models (two statistical models, two fuzzy inference systems, and one neural network) were developed using 70% of this data, and then tested using the remaining 30%. Results showed that the neural network described the most variation in test data (68%), followed by the data-dependent fuzzy …

Loss Of Phosphorus By Runoff For Agricultural Watersheds, M. A. Elrashidi, M. D. Mays, J. Harder, D. Schroeder, P. Brakhage, S. Peaslee, C. Seybold, C. Schaecher

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

The loss of nutrients in runoff from agricultural land is a major cause of poor surface water quality in the United State. Scientists (NRCS) developed a technique to estimate the impact of agricultural watersheds on natural water resources. The objectives of this study were to apply this technique on the Wagon Train (WT),watershed to predict (1) loss of water by surface runoff, (2) loss of phosphorus (P) from soils by runoff and P loading for WT reservoir. The annual loss of water by runoff was estimated at 4.32 million m³ . The USGS data for a 50-year period (1951 …

High-Throughput Immunoblotting Identifies Biotin-Dependent Signaling Proteins In Hepg2 Hepatocarcinoma Cells1, Rocio Rodriguez-Melendez, Jacob B. Griffin, Gautam Sarath, Janos Zempleni

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

Biotin affects the abundance of mRNA coding for ~10% of genes expressed in human-derived hepatocarcinoma (HepG2) cells. Here, we determined whether effects of biotin on gene expression are associated with changes in the abundance of distinct proteins in cell signaling and structure. HepG2 cells were cultured in media containing the following concentrations of biotin: 0.025 nmol/L (denoted “deficient”), 0.25 nmol/L (“physiological” = control), and 10 nmol/L (“pharmacological”) for 10 d before harvesting. The abundance of 1009 proteins from whole-cell extracts was quantified by using high-throughput immunoblots. The abundance of 44 proteins changed by at least 25% in biotin-deficient and biotin-supplemented …

Inactivation Of Enteric Adenovirus And Feline Calicivirus By Chlorine Dioxide, Jeanette A. Thurston-Enriquez, Charles N. Haas, Joseph Jacangelo, Charles P. Gerba

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

Chlorine dioxide (ClO₂) inactivation experiments were conducted with adenovirus type 40 (AD40) and feline calicivirus (FCV). Experiments were carried out in buffered, disinfectant demand-free water under high- and low-pH and -temperature conditions. Ct values (the concentration of ClO₂ multiplied by contact time with the virus) were calculated directly from bench-scale experiments and from application of the efficiency factor Hom (EFH) model. AD40 Ct ranges for 4-log inactivation (Ct_99.99%) at 5°C were >0.77 to 0.80 to 0.49 to Ct_99.99% ranges were observed for pH 6 and 8, respectively. FCV Ct_99.99% ranges for 5°C …

Plant Adaptation Regions: Ecological And Climatic Classification Of Plant Materials, Kenneth P. Vogel, Marty R. Schmer, Robert B. Mitchell

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

The effective use of plant materials for an array of objectives including conservation, restoration, renovation, landscaping, and bioremediation requires knowledge of the adaptation of each species and, more specifically, knowledge of the adaptation of cultivars, strains, accessions, or ecotypes of a species to specific sites or regions. For agronomic and horticultural plants, specific adaptation information has been and continues to be developed by extensive testing. Rangeland, grassland, park, and restoration project managers often lack the resources to determine adaptation areas for plant materials because of the large number of species that are used and the extensive geographical areas that are …

Dynamic Response Indicators Of Heat Stress In Shaded And Non-Shaded Feedlot Cattle, Part 2: Predictive Relationships, R. A. Eigenberg, T. M. Brown-Brandl, John A. Nienaber, G. Leroy Hahn

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

Summer heat provides stressful conditions for Bos taurus feeder cattle; in extreme instances these conditions can be fatal. One management option is to provide shade structures for feedlot animals. This study was conducted during the summer of 2001 to compare physiological responses of cattle with shade access or no-shade access. Eight steers were selected from a group of 12, and assigned individual pens. Four pens were fitted with shade structures that allowed the steers to choose shade; the remainder had no shade option. The animals were rotated through pen assignments during the summer season. Continuous measures of respiration rate and …

Big Bluestem Pasture In The Great Plains: An Alternative For Dryland Corn, Kenneth P. Vogel, Gary E. Varvel, Robert B. Mitchell, Terry J. Klopfenstein, Richard T. Clark, Bruce Anderson

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

Big bluestem pasture can earn more than twice as much per acre as dryland corn.

Corn production and perennial grass pastures provide the foundation for the agricultural industry in the central and eastern Great Plains. Typically, many producers grow both corn and perennial grass pastures to meet livestock feed demands and to diversify the operation. For example, corn was produced on more than 37% of the total cropland, and perennial pasture comprised 49% of the land in farms in Nebraska.1 Corn was produced on an average of 7.8 million acres in Nebraska from 2000 to 2002, with 40% being dryland …

Penicillin-Binding Proteins In The Pathogenic Intestinal Spirochete Brachyspira Pilosicoli, Rohana P. Dassanayake, Gautam Sarath, Gerald E. Duhamel

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

Penicillin-binding proteins (PBPs) of slightly different molecular masses (94, 62 or 68, 42 or 50, 25, and 22 kDa) were identified in one human and two porcine Brachyspira pilosicoli strains. Identification of PBPs of B. pilosicoli provides a basis for characterization of the genes encoding these proteins among pathogenic intestinal spirochetes of humans and animals.

Dynamic Response Indicators Of Heat Stress In Shaded And Non-Shaded Feedlot Cattle, Part 1: Analyses Of Indicators, T. M. Brown-Brandl, R. A. Eigenberg, J. A. Nienaber, G. Leroy Hahn

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

Heat stress in feedlot cattle can cause decreases in feed intake and growth, and in extreme cases may result in death. Providing shade during hot weather has shown inconsistent results, reducing direct and indirect losses in some areas of the United States, but not in others. The objectives of this study were to evaluate the dynamic responses of feedlot cattle to environmental conditions with and without access to shade, and to determine the most appropriate physiological measurement for monitoring feedlot cattle during hot weather as a guide for improved management. Eight crossbred steers (initially weighing 294.7±10.8 kg) were randomly assigned …

Soil Surveys: A Window To The Subsurface, Douglas A. Wysocki, P. J. Schoeneberger, H. E. Lagarry

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

Soils and underlying parent materials form a continuous system we must understand and manage in total. Numerous concerns (e.g., water quality, on-site waste disposal, landfill placement, and nutrient or pesticide movement) require an integrated knowledge and understanding of soil, the soil-to-substratum transition, and the deeper substratum. Soil C-horizons can exceed the thickness of the overlying A and B-horizons and contain unique morphological properties. The subsolum including C-horizons receives less descriptive emphasis than upper soil horizons. Soil scientists map and classify soils mainly on A and B-horizon properties. Soil forming and hydrologic processes that impart morphological features, however, extend considerably below …

Impact Of Reduced Lignin On Plant Fitness, J. F, Pedersen, K. P. Vogel, D. L. Funnell

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

Lignin content of crop plants has been reduced by traditional plant breeding, natural and induced mutations, and insertion of transgenes. The effects of these genes and associated lower lignin content have been examined in terms of agricultural fitness or with regard to economically harvestable yields of useful plant products, or, in the case of some perennial species, survivability over multiple years. In general, crop yields are depressed by significant reductions in lignin content. Other negative effects observed in plants with lowered lignin contents include lodging and reduction of long-term survival of some perennial species. However, the interactions of genes involved …

Colonization Of Gnotobiotic Piglets By A Luxs Mutant Strain Of Escherichia Coli O157:H7, Dianna M. Jordan, Vanessa Sperandio, James B. Kaper, Evelyn A. Dean-Nystrom, Harley W. Moon

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

Gnotobiotic piglets inoculated with Escherichia coli O157:H7, its luxS mutant derivative, or nonpathogenic E. coli were evaluated for attaching and effacing lesions. Although no differences in clinical symptoms were seen between pigs inoculated with the parent and those inoculated with the luxS mutant, the luxS mutant-inoculated pigs had a lower frequency of attaching and effacing lesions in the spiral colon than parent strain-inoculated pigs.

Molecular Evolution Of Herbicide Resistance To Phytoene Desaturase Inhibitors In Hydrilla Verticillata And Its Potential Use To Generate Herbicide-Resistant Crops, R. S. Arias, Michael D. Netherland, Brian E. Scheffler, Atul Puri, Franck E. Dayan

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

Hydrilla [Hydrilla verticillata (Lf) Royle] is one of the most serious invasive aquatic weed problems in the USA. This plant possesses numerous mechanisms of vegetative reproduction that enable it to spread very rapidly. Management of this weed has been achieved by the systemic treatment of water bodies with the herbicide fluridone. At least three dioecious fluridone-resistant biotypes of hydrilla with two- to fivefold higher resistance to the herbicide than the wild-type have been identified. Resistance is the result of one of three independent somatic mutations at the arginine 304 codon of the gene encoding phytoene desaturase, the molecular target …

Registration Of ‘Arrowsmith’ Hard White Winter Wheat, Robert A. Graybosch, C.J. Peterson, P. Stephen Baenziger, Lenis Alton Nelson, B.B. Beecher, D. D. Baltensperger, J.M. Krall

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

‘Arrowsmith’ (Reg. no. CV-969, PI 633911) hard white winter wheat (Triticum aestivum L.) was developed cooperatively by USDA-ARS, the Nebraska Agricultural Experiment Station, and the Wyoming Agricultural Experiment Station. Arrowsmith is adapted to dryland environments in western Nebraska and eastern Wyoming. It was released on the basis of its white grain color, medium-long coleoptile length, and tall plant height, all desirable features for wheat grown on dryland sites in the Nebraska Panhandle and eastern Wyoming.

Arrowsmith was derived from the cross KS87809-10/‘Arapahoe’, made in 1993. KS87809-10 is an experimental hard winter wheat from Kansas State University with the pedigree …

Evaluation Of Oviposition Substrates And Organic Infusions On Collection Of Culex In Florida, Sandra Allan, Ulrich R. Bernier, David Kline

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

Gravid mosquito traps are commonly used for both arbovirus surveillance and population surveillance of mosquitoes of the genus Culex. Oviposition substrates, used as baits in these traps, were tested against Culex under laboratory and field conditions. In the laboratory all substrates tested as 1% and 10% dilutions in 2-choice bioassays against female Cx. quinquefascians were significantly more effective than well water controls in eliciting oviposition. Strongest responses were to dilutions of dairy effluent, followed by larval water and infusions of alfalfa hay, alfalfa pellets, Bermuda hay, oak leaves, and Typha leaves, with lowest responses to cow manure infusion. …

Comparison Of Contact And Spatial Repellency Of Catnip Oil And N,N-Diethyl-3-Methylbenzamide (Deet) Against Mosquitoes, Ulrich R. Bernier, Kay D. Furman, Daniel L. Kline, Sandra A. Allan, Donald R. Barnard

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

Nepetalactone, the primary component of catnip oil, was compared with the repellent N,N-diethyl-3-methylbenzamide (deet) for its ability to affect the host-seeking ability of Aedes aegypti (L.). A triple cage olfactometer was used to bioassay each substance and to assess its attraction inhibition (spatial repellent) attributes when combined with the following attractants: carbon dioxide, acetone, a blend of L-lactic acid and acetone, and human odors. Repellent tests were conducted with each substance against female Ae. aegypti, Anopheles albimanus Weidemann, and Anopheles quadrimaculatus Say. Catnip oil and deet were both weakly attractive to Ae. aegypti, catnip oil was the better spatial …