Agricultural Science Commons^™

The Mycotoxin Threat To Food Safety, Ervin Balazs, James S. Schepers

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

This workshop entitled “Mycotoxins from the Field to the Table” held in Omaha, Nebraska, USA from 29 November to 1 December, 2006 evolved from the OECD (Organization for Economic Co-operation and Development) Co-operative Research Program on “Biological Resource Management” that was initiated in 1979. It currently focuses on three specific areas, namely the natural resources challenge, sustainability in practice, and the food chain. This workshop was organized under the sustainability and food chain themes.

The Cooperative Research Program's two major activities are promotion of expert exchanges by supporting postdoctoral fellowship awards up to 26 weeks in an OECD host laboratory …

Source Tracking Of Microbial Intrusion In Water Systems Using Artificial Neural Networks, Minyoung Kim, Christopher Y. Choi, Charles P. Garba

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

A ‘‘what-if’’ scenario where biological agents are accidentally or deliberately introduced into a water system was generated, and artificial neural network (ANN) models were applied to identify the pathogenic release location to isolate the contaminated area and minimize its hazards. The spatiotemporal distribution of Escherichia coli 15597 along the water system was employed to locate pollutants by inversely interpreting transport patterns of Escherichia coli using ANNs. Results showed that dispersion patterns of Escherichia coli were positively correlated to pH, turbidity, and conductivity (R² = 0.90–0.96), and the ANN models successfully identified the source location of Escherichia coli introduced into …

Biofuel Feedstocks: The Risk Of Future Invasions, Joseph M. Ditomaso, Jacob N. Barney, Alison M. Fox

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

In an effort to decrease greenhouse gas emissions, expand domestic energy production, and maintain economic growth, public and private investments are being used to pursue dedicated feedstock crops for biofuel production. Unlike food crops grown for grain-based ethanol (e.g., corn), which require high inputs of fertilizers and pesticides and typically are grown on prime agricultural land, proposed lignocellulose-based energy crops (e.g., switchgrass) typically have a neutral or negative carbon budget, require relatively few economic or environmental inputs, and can be cultivated on marginal, lower-productivity land. Thus, a rapidly growing industry related to crop selection, cultivar improvement, and conversion technologies is …

Convergence Of Agriculture And Energy: Ii. Producing Cellulosic Biomass For Biofuels, Steven L. Fales, J. Richard Hess, Wallace Wilhelm, Don Erbach, William D. Provine, Kenneth P. Vogel, Todd A. Peterson, Edward C. A. Runge

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

Global energy demand is increasing as known global petroleum supplies are decreas¬ing. Calls to supplement or replace the current fossil-based energy system with new, envi¬ronmentally and economically sustainable strategies continue to increase, especially in light of more expensive traditional energy sources. Various governmental agencies and working groups have set aggressive targets and timelines for decreasing fossil fuel consumption by substituting bio-based energy (Bush 2007; Foust et al. 2007; Perlack et al. 2005; Smith et al. 2004). The alignment and continuity of these goals is illustrated in Figure 1.
Current biofuel production in the United States relies primarily on corn grain …

K12-Biotinylated Histone H4 Marks Heterochromatin In Human Lymphoblastoma Cells, Gabriela Camporeale, Anna M. Oommen, Jacob B. Griffin, Gautam Sarath, Janos Zempleni

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

Covalent modifications of histones play crucial roles in chromatin structure and genomic stability. Recently, we reported a novel modification of histones: biotinylation of lysine residues. Here we provide evidence that K12-biotinylated histone H4 (K12Bio H4) maps specifically to both heterochromatin (alpha satellite repeats in pericentromeric regions) and transcriptionally repressed chromatin (γ-G globin and interleukin-2) in human lymphoblastoma cells. The abundance of K12Bio H4 in these regions was similar to that of K9-dimethylated histone H3, a known marker for heterochromatin. Likewise, K8-biotinylated histone H4 (K8Bio H4) mapped to heterochromatin, but the relative enrichment was smaller compared with K12Bio H4. Stimulation of …

Engineering, Nutrient Removal, And Feedstock Conversion Evaluations Of Four Corn Stover Harvest Scenarios, Reed L. Hoskinson, Douglas L. Karlen, Stuart J. Birrell, Corey W. Radtke, Wally Wilhelm

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

Crop residue has been identified as a near-term source of biomass for renewable fuel, heat, power, chemicals and other bio-materials. A prototype one-pass harvest system was used to collect residue samples from a corn (Zea mays L.) field near Ames, IA. Four harvest scenarios (low cut, high-cut top, high-cut bottom, and normal cut) were evaluated and are expressed as collected stover harvest indices (CSHI). High-cut top and high-cut bottom samples were obtained from the same plot in separate operations. Chemical composition, dilute acid pretreatment response, ethanol conversion yield and efficiency, and thermochemical conversion for each scenario were determined. Mean …

Summaries Of Arkansas Cotton Research 2006, Derrick M. Oosterhuis

Arkansas Agricultural Experiment Station Research Series

No abstract provided.

Source Tracking Of Microbial Intrusion In Water Systems Using Artificial Neural Networks, Minyoung Kim, Christopher Y. Choi, Charles P. Gerba

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

A ‘‘what-if’’ scenario where biological agents are accidentally or deliberately introduced into a water system was generated, and artificial neural network (ANN) models were applied to identify the pathogenic release location to isolate the contaminated area and minimize its hazards. The spatiotemporal distribution of Escherichia coli 15597 along the water system was employed to locate pollutants by inversely interpreting transport patterns of E. coli using ANNs. Results showed that dispersion patterns of E. coli were positively correlated to pH, turbidity, and conductivity (R² = 0.90–0.96), and the ANN models successfully identified the source location of E. coli introduced into …

Comparison Of Laboratory Methods And An In Situ Method For Estimating Nitrogen Mineralization In An Irrigated Silt-Loam Soil, Brian J. Wienhold

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

Nitrogen (N) mineralization makes a considerable contribution to crop-available N and is difficult to estimate. Reliable methods for measuring N mineralization are needed to produce data sets for developing N-mineralization models, as a component in fertilizer recommendation algorithms, and to assess the effect of management practices on N mineralization. Numerous methods are available for estimating N mineralization. Laboratory methods are relatively easy but may not reflect conditions in the field, and field methods are usually labor-intensive. A study was conducted to compare N-mineralization estimates using anaerobic and aerobic laboratory methods and an in situ field method for the 0- to …

The Effect Of Residue C:N Ratio On The Turnover Of N And C In Various Soil Organic Matter Fractions, Ana B. Wingeyer

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Identifying soil organic matter (SOM) fractions that contribute to soil indigenous nitrogen (N) supply and understanding their turnover under different management constitute necessary tools toward an efficient N use. The objectives of this study were: i) trace the endpoint of carbon (C) flux from residue inputs into SOM; and ii) asses the role of the light fraction (LF), mobile humic acid (MHA) fraction and calcium humate (CaHA) fraction as N sources for heterotrophic decomposition of fresh plant residues with contrasting C:N ratio. A long-term aerobic soil incubation was carried out on ¹⁵N-labeled soil samples from Lincoln and Mead, NE. …

Usda-Ars Lincoln Location Contact Information

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

Grain, Forage, & Bioenergy Research Unit
Mid-West Livestock Research Unit
Soil & Water Conservation Research Unit
Employee Listing

The mission of the USDA / ARS programs at Lincoln, Nebraska is to improve the productivity, stability of production, sustainability and profitability of crop and livestock production systems in the Great Plains

The Lincoln Location is a part of the Northern Plains Area (NPA) of the Agricultural Research Service (ARS), a Research, Education and Economics (REE) agency, and the main in-house research arm of the United States Department of Agriculture (USDA)

Internode Structure And Cell Wall Composition In Maturing Tillers Of Switchgrass (Panicum Virgatum. L), Gautam Sarath, Lisa M. Baird, Kenneth P. Vogel, Robert B. Mitchell

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

This work examined cell composition gradients in maturing tillers of switchgrass (Panicum virgatuln L. ) with the aim of developing baseline information on this important forage and biomass crop. Flowering tillers were collected from plants raised from seeds in a greenhouse and field, harvested at soil level and separated into internodes beginning with the node subtending the peduncle. Internodes were analyzed using microscopy, by fiber digestion, high-performance liquid chromatography and by gas chromatography-mass spectrometry to obtain anatomical and compositional data. Microscopy demonstrated the development and maturation of cortical fibers which eventually became confluent with the fiber sheath surrounding vascular …

Cloning And Expression Of An Atrazine Inducible Cytochrome P450, Cyp4g33, From Chironomus Tentans (Diptera: Chironomidae), Diana K. Londono, Herbert A.A. Siqueira, Haichuan Wang, Gautam Sarath, Michael J. Lydy, Blair D. Siegfried

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

Previous studies performed in our laboratory have measured the effect of atrazine exposure on cytochrome P450-dependent monooxygenase activity and have found increased activity in midge larvae (Chironomus tentans) as a result of atrazine exposure (1– 10 ppm). Here we report the cloning and expression of a specific C. tentans CYP4 gene that is responsive to atrazine induction with an open reading frame of 1678 bp which encodes a putative protein of 559 amino acid residues. Alignments of deduced amino acid sequences with other insect P450 genes and phylogenetic analysis indicated a high degree of similarity to other insect …

Comparative Genomics Reveals Functional Transcriptional Control Sequences In The Prop1 Gene, Robert D. Ward, Minchul Cho, S. A. Camper, Shannon W. Davis, Lori T. Raetzman, Timothy P.L. Smith, Constance Esposito, Robert H. Lyons, Jan-Fang Cheng, Edward M. Rubin, Simon J. Rhodes

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

Mutations in PROP1 are a common genetic cause of multiple pituitary hormone deficiency (MPHD). We used a comparative genomics approach to predict the transcriptional regulatory domains of Prop1 and tested them in cell culture and mice. A BAC transgene containing Prop1 completely rescues the Prop1 mutant phenotype, demonstrating that the regulatory elements necessary for proper Prop1 transcription are contained within the BAC. We generated DNA sequences from the PROP1 genes in lemur, pig, and five different primate species. Comparison of these with available human and mouse PROP1 sequences identified three putative regulatory sequences that are highly conserved. These are located …

Australian Temperate Strawberry Breeding Program (Albany Western Australia) Screening Of Advance And New Selections For Albany Western Australia - 2006/2007, Shane Trainer, Dennis Phillips, Hal

Horticulture research reports

Fourteen intermediate day neutral selections from the Australian temperate breeding program were compared in a June trial planting on a commercial property in the Albany region. Intermediate selections were derived from crosses made between 1999 and 2002. Three advanced 'short day' selections were compared for yield, both as trial plots (10 plants) and as large plot demonstrations of up to 500 plants. Accompanying these selections, six named day neutral, three short day and four Queensland cultivars of different runner origins were compared. Camarosa, Selva and Diamante were included as commercial controls.

Day neutral selections 02-083-24 and 02-83-311 were potentially superior …

What We Do Know About Rice (Oryza Sativa) Hemoglobins, Veronica Lira-Ruan, Emily H. Ross, Mark S. Hargrove, Gautam Sarath, Raul Arredondo-Peter, Robert V. Klucas

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

Nonsymbiotic hemoglobins (nsHb) are proteins widely distributed in land plants, however their function in plant organs is still not known. Rice nsHbs have been characterized in detail and represent a model to study plant nsHbs. Rice recombinant Hb1 (rHb1) has a very high affinity for O₂ (1,800 μM^-1 s^-1), because the dissociation constant is extremely low (k_off = 0.038 s^-1). X-ray analysis and site-directed mutagenesis showed that the low dissociation constant of rHb1 is partially due to the stabilization of bound O₂ by distal His. This characteristic suggests that the function of …

Tillage And Rotation Effect On Corn–Soybean Energy Balances In Eastern Nebraska, G.-W. Rathke, Brian Wienhold, Wallace Wilhelm, W. Diepenbrock

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

Data from a field experiment conducted in eastern Nebraska over 16 years (1986–2001) were used to determine the energy balance of corn (Zea mays L.) and soybean (Glycine max L.) as affected by tillage treatments and rotation. Tillage treatments included chisel plow, tandem disk, moldboard plow, ridge-tillage, no-till and subsoil tillage. Crop sequences were continuous corn, continuous soybean, corn in a corn–soybean rotation and soybean in a soybean–corn rotation. The energy balance was assessed by comparing the parameters: energy gain (net energy output), energy intensity (energy input per unit grain equivalent, GE) and output/input ratio. Changes in plant …

Arkansas Small-Grain Cultivar Performance Tests 2006-2007, J. T. Kelly, M. J. Emerson, R. K. Bacon, E. A. Milus

Arkansas Agricultural Experiment Station Research Series

Small-grain cultivar performance tests are conducted each year in Arkansas by the Arkansas Agricultural Experiment Station, Department of Crop, Soil, and Environmental Sciences. The tests provide information to companies developing cultivars and/or marketing seed within the state and aid the Arkansas Cooperative Extension Service in formulating cultivar recommendations for smallgrain producers.

B.R. Wells Rice Research Studies 2006, R. J. Norman, J. F. Meullenet, K. A.K. Moldenhauer

Arkansas Agricultural Experiment Station Research Series

No abstract provided.

Differential Expression Of The Crv1 Haemocyte Inactivation-Associated Polydnavirus Gene In The African Maize Stem Borer Busseola Fusca (Fuller) Parasitized By Two Biotypes Of The Endoparasitoid Cotesia Sesamiae (Cameron), C. W. Gitau, D. Gundersen-Rindal, M. Pedroni, P. J. Mbugi, S. Dupas

All Peer-Reviewed Publications

Polydnaviruses are rarely studied for their natural variation in immune suppressive abilities. The polydnavirus harboring braconid Cotesia sesamiae, a widespread endoparasitoid of Busseola fusca and Sesamia calamistis in sub-Saharan Africa exists as two biotypes. In Kenya, the western biotype completes development in B. fusca larvae. However, eggs of the coastal C. sesamiae are encapsulated in this host and ultimately, no parasitoids emerge from parasitized B. fusca larvae. Both biotypes develop successfully in S. calamistis larvae. Encapsulation activity by B. fusca larvae towards eggs of the avirulent C. sesamiae was detectable six hours post-parasitization. The differences in encapsulation of virulent and …

Cross-Modality Effects During Male-Male Interactions Of Jumping Spiders, Fiona R. Cross, Robert R. Jackson, Simon D. Pollard, Mark W. Walker

All Peer-Reviewed Publications

An important prediction from game theory is that the value of a resource influences the level to which male-male conflict escalates. Earlier experimental studies have shown that the seven salticid species we study here (Bavia aericeps, Euryattus sp., Hypoblemum albovittatum, Jacksonoides queenslandicus, Marpissa marina, Portia africana and Simaetha paetula) determine by sight whether a female is a conspecific or a heterospecific and then escalate the intensity with which they interact (i.e., they adopt behaviour that is likely to put them at greater risk of injury after detecting the presence of a conspecific female). Here the earlier studies are extended by …

Livestock Farmers' Perception And Epidemiology Of Bovine Trypanosomosis In Kwale District, Kenya, S. O. Ohaga, E. D. Kokwaro, I. O. Ndiege, A. Hassanali, R. K. Saini

All Peer-Reviewed Publications

We did cross-sectional surveys in Kwale District, Kenya to determine the epidemiology of bovine trypanosomosis and livestock owners' perceptions of the disease. The surveys involved relative importance of trypanosomosis, examination of the current disease constraints, current control practices and drug-use patterns. Informal meetings were held with farmers and cattle census undertaken. Tsetse-fly densities and trypanosomosis prevalences in cattle were determined. A total of 132 farmers were interviewed. Trypanosomosis, anaplasmosis, East Coast fever, foot-and-mouth diseases were reported to be the major constraints to livestock production. Trypanosomosis was the most important compared to other diseases. Chemotherapy was the most widely used method …

An Avidin-Based Assay For Histone Debiotinylase Activity In Human Cell Nuclei, Yap Ching Chew, Gautam Sarath, Janos Zempleni

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

The covalent binding of biotin to histones participates in heterochromatin formation, cell cycle progression and cellular response to DNA breaks. Biotinylation of histones appears to be a reversible process, but the identity of enzymes that remove biotin marks is largely unknown. Our long-term goal is to identify histone debiotinylases in human cells. Here we developed an avidin-based plate assay to quantify histone debiotinylase activities in nuclear extracts. This assay is an essential first step in purifying and identifying histone debiotinylases from human cells. Using this assay, we demonstrated that debiotinylation of histones depends on temperature and pH, consistent with enzyme …

Modeling Beaver Dam Effects On Ecohydraulics And Sedimentation In An Agricultural Watershed, Mary Carla Mccullough, Dean E. Eisenhauer, Michael G. Dosskey, David M. Admiraal

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

Populations of North American beaver (Castor canadensis) have increased in recent decades throughout the agricultural Midwestern U.S., leading to an increase in the frequency of beaver dams in small streams. The impact of beaver dams on channel structure in this region is not known. Our field observations indicate that beaver dams are too dynamic and their affects on channel structure occur over longer time frames than is practical to study with field measurements. Modeling is therefore needed to determine if beaver dams will help stabilize and aggrade incised streams. The objective of this paper is to determine how …

Plant Growth-Promoting Rhizobacteria Do Not Pose Any Deleterious Effect On Cowpea And Detectable Amounts Of Ethylene Are Produced, Olubukola O. Babalola, Abiodun I. Sanni, George D. Odhiambo, Baldwyn Torto

All Peer-Reviewed Publications

The use of trap crops such as cowpea could reduce the effects of the root parasitic weed, Striga hermonthica and its subsequent constraints on the growth of cereals. Certain bacteria could augment the trap crop stimulatory effect. We studied the effect of three bacteria introduced to the rhizosphere of three cowpea varieties at planting. Number of days to cowpea flowering was noted and at harvest, data were collected on pod characteristics and biomass. Means of data subjected to ANOVA were compared using Tukey's Studentized Range Test. We analysed bacterial headspace volatiles for ethylene by gas chromatography and gas chromatography-mass spectrometry. …

El Salvador President Tony Saca Releases Sorghum Forage Hybrid “Centa Ss - 44", Intsormil

INTSORMIL Impacts and Bulletins

President of the Republic of El Salvador, Don Elias Antonio Saca, on May 17, 2006 officially gave the green light to the opening of the agricultural year 2006-2007. Speaking in the city of Turin in the western department of Ahuachapán, El Salvador, he informed the nation’s thousands of farmers that the opportune moment to begin planting had again arrived. The Chief of State let it be known that this celebration in Turin was a clear signal to the nation’s farmers that the Government of El Salvador pledges its support to assist the farming community in producing the necessary food for …

El Presidente De El Salvador Tony Saca Libera El Híbrido De Sorgo Para Forrajes “Centa Ss - 44”, Intsormil

INTSORMIL Impacts and Bulletins

El 17 de Mayo del 2006 el Presidente de El Salvador Don Elias Antonio Saca, oficialmente inauguró el año agrícola 2006- 2007. En su discurso en la ciudad de Turín localizada en el Departamento de Auachapán al oeste de El Salvador, el presidente informó a los miles de agricultores de la nación que era el momento oportuno para comenzar a sembrar nuevamente. El jefe del estado les dejó conocer a todos los agricultores de la nación, que esta celebración en Turín era una clara evidencia que el gobierno de El Salvador prometía su ayuda en asistir a la comunidad granjera …

Centa Ss-44, Nuevo Híbrido De Sorgo Para Forraje En El Salvador, Intsormil

INTSORMIL Impacts and Bulletins

Uno de los problemas que más acosa el desarollo de la industria lechera en Centro América es la falta de forraje de buena calidad, lo cual se traduce en baja producción tanto de leche como de carne y en aumento en los costos de producción. Muchos ganaderos productores de leche, en su búsqueda por un adecuado forraje para alimentar el hato de vacas, utilizan híbridos de sorgo o maíz de baja calidad lo cual resulta en pérdidas económicas.

En el caso del sorgo, el mayor problema es la falta de cultivares que tengan los siguientes atributos 1) sean tempranos, 2) …

Centa Ss- 44, New Sorghum Forage Hybrid For El Salvador, Intsormil

INTSORMIL Impacts and Bulletins

One of the major problems plaguing the development of the Central American dairy industry is the lack of good quality forage which results in low milk and meat production and an increase in production costs. Many dairy farmers, in their search for suitable forage to feed their cattle herds, utilize poor quality sorghum or maize hybrids which can result in economic losses.

In the case of sorghum, the major problem is a lack of cultivars that (1) are early, (2) grow rapidly, (3) are of proper plant height, (4) are resistant to diseases, (5) have high yield potential and (6) …

Effects Of Forage Management On Pasture Productivity And Phosphorus Content, M. M. Haan, J. R. Russell, J. L. Kovar, W. J. Powers, J. L. Benning

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

The objectives of the current study were to determine the amounts of above- and below-ground plant biomass production, P uptake by forage, and P concentration of cool-season grass forage as influenced by management and season. Five forage management treatments were evaluated over 3 years in smooth bromegrass (Bromus inermis Leyss) pastures. Management practices were: ungrazed (U), hay harvest/fall stockpile grazing (HS), rotational stocking to residual sward heights of 10 (10R) or 5 (5R) cm, and continuous stocking to maintain sward height at 5 cm (5C). Forage samples were hand-clipped within and outside grazing exclosures monthly from April through November …