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Cytotoxic Necrotizing Factor Type 2 Produced By Virulent Escherichia Coli Modifies The Small Gtp-Binding Proteins Rho Involved In Assembly Of Actin Stress Fibers, Eric Oswald, Motoyuki Sugai, Agnès Labigne, Henry C. Wu, Carla Fiorentini, Patrice Boquet, Alison D. O'Brien

Uniformed Services University of the Health Sciences

Cytotoxic necrotizing factor type 2 (CNF2)produced by Escherichia coli strains isolated from intestinal and extraintestinal infections is a dermonecrotic toxin of 110 kDa. We cloned the CNF2 gene from a large plasmid carried by an Escherichia coli strain isolated from a lamb with septicemica. Hydropathy analysis of the deduced amino acid sequence revealed a largely hydrophilic protein with two peotential hydrophobic transmembrane domains. The N-terminal half of CNF2 showed striking homology (27% identity and 80% conserved residues) to the N-terminal portion of Pasteurella multocida toxin. Methylamine protection experiments and immunofluorescence studies suggested that CNF2 enters the cytosol of the target …

Extension And Education Materials For Sustainable Agriculture, Volume 2, James W. King, Charles A. Francis

CARI Extension and Education Materials for Sustainable Agriculture

Extension and Education Materials for Sustainable Agriculture

Curricula in Sustainable Agriculture

Introduction to Curricula in Sustainable Agriculture

Sustainable Agriculture, Agronomy 493/593 Course Outline

Sustainable Agriculture, Agronomy 493/AG*SAT

Principles and Practices of Sustainable Agriculture

Agricultural Ecosystems

Agricultural Ecology

Agroecology

Agricultural Ecology and Sustainability

Alternative Agriculture Curriculum

Sustainable Agriculture (B.S.)

Environment and World Food Production

Issues (Advanced) in Sustainable Agriculture

Crops, Soil, and Civilization, Agronomy 440

Master of Science in Sustainable Systems

Agricultural Ecology

National Curriculum for Sustainable Agriculture

Reshaping Undergraduate and Graduate Education to Include a Whole Systems Emphasis

Sustainable Agriculture Education: A Panel

Impact of Sustainable Agriculture Programs on United.States …

“Introduction” To Integrative Views Of Motivation, Cognition, And Emotion, William D. Spaulding

Department of Psychology: Faculty Publications

One of my formative experiences as a graduate student came during a break in our afternoon-long first-year proseminar. We had been discussing the scope of psychology, or rather, listening to two professors debate the scope of psychology. Both the protagonists were clinical psychologists by training, but one had remained an empirically focused social learning theorist, while the other had pursued the study of Eastern religion, psychoanalysis, and transpersonal psychology. As the class milled about, the social learning empiricist sought some closure on the discussion. "Dick," he said to his transpersonal colleague, "it seems to me that we disagree because in …

Nebraska Summary: S159 John Deere 6400, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

Cultural Considerations In The Experience Of Aging: Two African Cultures, Patricia Draper, Henry Harpending

Department of Anthropology: Faculty Publications

We have three general conclusions to emphasize as well as an observation about aging in these [!Kung and Herero] societies that we believe deserves elaboration:

1. Old people are treated well in both these groups but not because they are scarce. Both the !Kung and the Herero are low-fertility populations so the proportion of the total population that is old is high in both groups.

2. Old people do not appreciate what appears to be the good (!Kung) and superb (Herero) social support that they receive. They have nothing good to say about being old. While we perceived very positive …

Screening Sunflower For Tolerance To Sunflower Midge Using The Synthetic Auxin 2,4-Dichlorophenoxyacetic Acid, Gary J. Brewer, Marc D. Anderson, N. V. Rama Raje Urs

Department of Entomology: Faculty Publications

The sunflower midge, Contarinia schulzi Gagné, causes economic damage by inducing abnormal growth in infested heads (capitula) of sunflower, Helianthus annuus L. The primary objective of this study was to determine whether sunflower midge damage could be simulated and whether that simulated damage could be used to select midge-tolerant sunflower germplasm. An additional objective was to develop a quantitative alternative to the scoring systems used to visually estimate damage. Sunflower plants were treated by injecting buds with the synthetic auxin 2,4-dichlorophenoxyacetic acid (2,4-D), which resulted in a distortion of the head morphology that was similar in appearance to the damage …

Population Genetics And Gene Variation In Primary And Secondary Screwworm (Diptera : Calliphoridae), David B. Taylor, Richard D. Peterson Ii

Department of Entomology: Faculty Publications

Allozyme variation in screwworm, Cochliomyia hominivorax (Coquerel), and secondary screwworm, C. macellaria (F.), populations from northwest Costa Rica was examined . Variability was observed in 11 of 13 enzyme loci and the frequency of the most common allele was <0.95 for 5 loci in screwworm . In secondary screwworm, 12 of 13 loci were variable and the frequency of the most common allele was <0.95 for 6 loci . Expected heterozygosities were 0.149 and 0.160 for screwworm and secondary screwworm, respectively. Goodness-of-fit statistics for Hardy-Weinberg equilibrium and Wrights F statistics indicated that both species are panmictic with no evidence of population substructuring. Nei ' s genetic distances were 0.000–0.001 for intraspecific comparisons and 0.899–0.916 for interspecific comparisons. The data indicate a high level of gene flow between populations within each species.

Rice Pests In The Ivory Coast, West Africa: Farmers’ Perceptions And Management Strategies, A. A. Adesina, D. E. Johnson, E. A. Heinrichs

Department of Entomology: Faculty Publications

An understanding of farmers’ perceptions of pests and their existing pest control methods can make an important contribution to the development of effective integrated pest management strategies. While the relatively successful rice IPM technologies in Asia have been extensively documented in studies examining farmers’ pest perceptions and management practices, studies examining, specifically, perceptions and management practices of West African rice farmers are rare. This may reflect the more limited success to date in the implementation of rice IPM strategies in the region. This paper describes rice pests, pest perceptions, and management practices of smallholder rice farmers in the Ivory Coast. …

Flight Behavior And Seasonal Trapping Of Rhynchophorus Cruentatus (Coleoptera: Curculionidae), Thomas J. Weissling, Robin M. Giblin-Davis, Barbara J. Center, Tak Hiyakawa

Department of Entomology: Faculty Publications

Flight behavior, activity, and seasonal variation in capture of Rhynchophorus cruentatus (F.) were investigated. Response of R. cruentatus to traps baited with palm tissue was assessed at four locations in Florida over a 12- to 18-mo period. Capture of weevils varied by location and through time. Average temperature, the difference between high and low temperature, and total rainfall during trapping periods were not correlated with seasonal trends, but capture peaked in the spring following rise in temperature. Preflight behaviors of R. cruentatus were consistent for all weevils tested. Weevils preparing for flight first wipe their rostrum with the prothoracic legs, …

Development Of Multiple Pest Resistant Crop Cultivars, Elvis A. Heinrichs

Department of Entomology: Faculty Publications

Insects are one, among a number, of biotic and abiotic constraints that limit the production of food crops. Entomologists can play a key role in increasing food production through the development of insect-resistant crop cultivars. Resistant cultivars are sought as a major tactic in the development of IPM strategies and have been shown to be compatible with biological, chemical and cultural control tactics. There has been significant progress in the breeding and commercial utilization of multiple pest resistant crop cultivars having resistance to insects, diseases and nematodes. The most notable examples are rice cultivars which are grown on millions of …

Colony Isolation And Secondary Culture Of Fetal Porcine Hepatocytes On Sto Feeder Cells, Neil C. Talbot, Vernon G. Pursel, Caird E. Rexroad Jr., Thomas J. Caperna, Anne M. Powell, Roger T. Stone

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

The secondary culture of non-transformed parenchymal hepatocytes has not been possible. STO feeder cell-dependent secondary cultures of fetal pig hepatocytes were established by colony isolation from primary cultures of 26-d fetal livers. The liver cells had the typical polygonal morphology of parenchymal hepatocytes. They also spontaneously differentiated to form small biliary canaliculi between individual cells or progressed further to large multicellular duct-like structures or cells undergoing gross lipid accumulation and secretion. The secondary hepatocyte cultures expressed alpha-fetoprotein (AFP), albumin, and β-fibrinogen mRNA, and conditioned medium from the cells contained elevated levels of transferrin and albumin. STO feeder cell co-culture may …

Effect Of The Conceptus And Lack Of Effect Of Uterine Space On Endometrial Protein Secretion During Mid-Gestation In Swine, Jeffrey Vallet, Harold Klemcke, Ronald Christenson

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

The effect of the conceptus and of reduced uterine space on endometrial protein secretion was examined on Days 40, 60, and 80 of gestation in white crossbred gilts. Twenty-nine gilts were checked daily for estrus, and 15 were given 5 mg estradiol valerate daily from Days 11 to 15 (Day 0 = day of estrus) of the estrous cycle to induce pseudopregnancy. The remaining 14 pigs were mated during estrus. All pigs were laparotomized on Day 4, and one uterine horn was ligated to produce one crowded and one roomy uterine environment. Pigs were killed on Days 40, 60, and …

Purification Of The Major Soybean Leaf Acid Phosphatase That 1s Increased By Seed-Pod Removal, Paul E. Staswick, Chuck Papa, Jing-Feng Huang, Yoon Rhee

Department of Agronomy and Horticulture: Faculty Publications

Fruit removal for 5 weeks after flowering increased acid phosphatase activity 10-fold in soybean (Glycine max 1. Merr. vai Hobbit) leaves compared with normal seed-pod-bearing plants. The major acid phosphatase activity in leaves was purified over 2700-fold, yielding a single polypeptide of 51 kD with a specific activity of 1353 units/mg protein using p-nitrophenylphosphate as the substrate. lsoelectric focusing demonstrated that the purified protein co-migrated with a majority of the activity that increased in leaves following seed-pod removal. lmmunoblot analysis demonstrated that at least part of the increased activity was dueto an increased abundance of the phosphatase protein. In situ …

Effects Of Offshore Oil And Gas Development: A Quarterly Current Awareness Bibliography, January 1994, Sue Ann Gardner

University of Nebraska-Lincoln Libraries: Faculty Publications

The January 1994 issue of Effects of Offshore Oil and Gas Development: A Quarterly Current Awareness Bibliography.

Eicosanoids Mediate Insect Nodulation Responses To Bacterial Infections, Jon S. Miller, Tuanh Nguyen, David W. Stanley-Samuelson

Department of Entomology: Faculty Publications

We propose that nodule formation is mediated by eicosanoids in insects. Nodulation is the temporally and quantitatively predominant cellular defense response to bacterial infection in insects and other invertebrates. Inhibition of eicosanoid biosynthesis in larvae of the tobacco hornworn Manduca sexta immediately prior to intrahemocoelic infections with the bacterium Serratia marcescens strongly reduced the nodulation response. Inhibition of eicosanoid biosynthesis also reduced formation of cellular aggregates at 1 hr postinfection, which indicates that eicosanoids mediate early stages of nodulation. Separate treatments with specific inhibitors of phospholipase A₂, cyclooxygenase, and lipoxygenase reduced nodulation, which supports the view that nodule …

The Caulobacter Crescentus Flbd Protein Acts At Ftr Sequence Elements Both To Activate And To Repress Transcription Of Cell Cycle-Regulated Flagellar Genes, Andrew K. Benson, Girija Ramakrishnan, Noriko Ohta, Junli Feng, Alexander J. Ninfa, Austin Newton

Department of Food Science and Technology: Faculty Publications

The flagellar genes (fla genes) in Caulobacter crescentus are categorized into a regulatory hierarchy of four levels, I-IV, in which transcription of the class III and class IV genes late in the cell cycle from σ⁵⁴-dependent promoters depends on expression of the class II genes above them. Timing of fla gene expression has been attributed to sequential activation and repression by specific transcription factors. Here we report that purified FlbD activates transcription in vitro from the σ⁵⁴-dependent class III flbG promoter and represses transcription from the class II fliF promoter by binding to ftr (flagellar …

Early History Of The North Dakota Natural Science Society, John T. Lokemoen

United States Geological Survey, Northern Prairie Wildlife Research Center: Publications

A year ago, Paul Kannowski, editor of The Prairie Naturalist, asked me to write a short history of the formative period of the North Dakota Natural Science Society (Society). Finally, a year later, I accomplished the task. It seems that the history of the Society might be a little tedious to current readers of The Prairie Naturalist. However, the history of an organization that has succeeded for 25 years is worthy of documentation. Also, I take some comfort from the thought that many "old-timers" and prior North Dakota residents still belong to the Society and presumably take an …

Identification And Characterization Of The Ecdysteroid Udpglucosyltransferase Gene Of The Lymantria Dispar Multinucleocapsid Nuclear Polyhedrosis Virus, Christopher I. Riegel, Carita Lanner-Herrera, James M. Slavicek

United States Department of Agriculture, Forest Service / University of Nebraska-Lincoln: Faculty Publications

We have located, cloned, sequenced and characterized the ecdysteroid UDP-glucosyltransferase gene (egt) gene from the baculovirus Lymantria dispar multinucleocapsid nuclear polyhedrosis virus,(LdMNPV), which is specific for the gypsy moth (L. dispar). The egt gene from the related baculovirus Autographa californica multinucleocapsid nuclear polyhedrosis virus (AcMNPV) disrupts the hormonal balance of the host larva by galactosylating ecdysone, which prevents moulting. The location of the LdMNPV egt gene, determined by hybridization analysis using a cloned coding segment of the AcMNPV egt gene, was mapped to between 79.1 and 80.2 map units on the viral genome. This region contains an open …

Final Environmental Assessment For Endangered Species Habitat Improvement/Creation In The Missouri River Between The Niobrara River And Ponca, Nebraska

United States Army Corps of Engineers, Omaha District

An environmental assessment has been prepared for new habitat development in upper Lewis and Clark Lake and the Missouri River below Gavins Point Dam. The actions described are in response to the November 1990, U.S. Fish and Wildlife Service Biological Opinion on the operation of the Missouri River Main Stem System, and will provide safer nesting habitat for the interior least tern (endangered species) and the piping plover (threatened species).

Vegetation on the river islands will be removed and maintained in the "sparsely vegetated" state needed for nesting habitat for the terns and plovers. After vegetation removal, the islands will …

Communal Roosting And Foraging Behavior Of Staging Sandhill Cranes, Donald Sparling, Gary Krapu

United States Geological Survey, Northern Prairie Wildlife Research Center: Publications

Each spring more than 300,000 Sandhill Cranes (Grus canadensis) roost communally at night in river channels in the Platte River Valley of Nebraska and disperse at dawn to forage in agricultural fields. Cranes with central roosts had activity ranges double the size of those with peripheral roosts; 42% of the birds changed activity ranges prior to the onset of migration. Minimum daily flight distance generally increased during the staging period. Cranes used native grassland and planted hayland more often than expected, relative to their percentage of occurrence, and fed longest there; cornfields were under-utilized. These differences probably reflect, …

The Status Of Nebraska Fishes In The Missouri River. 6. Sauger (Percidae: Stizostedion Canadense), Larry W. Hease

United States Army Corps of Engineers, Omaha District

Saugers were once common representatives of the Missouri River fish assemblage. Prior to channelization and impoundment, they comprised from 10 to 65% of the main channel big-river fish group. They utilized the slower side channels and backwaters seasonally for feeding, resting, and maturing, but the main channel was important for breeding habitat, Since the onset of channelization and impoundment, saugers have been reduced by as much as 98% in some areas, and the trend toward extirpation continues unabated today. Recovery of native sauger stocks will require a complete cessation of harvest, recovery of the natural hydrograph, recovery of sediment transport, …

Evaluation Of Pcr For Diagnosis Of Bovine Viral Diarrhea Virus In Tissue Homogenates, Beverly Schmitt, Osvaldo Lopez, Julia Ridpath, Judith Galeota-Wheeler, Fernando A. Osorio

School of Veterinary and Biomedical Sciences: Faculty Publications

Tissue homogenates from 60 specimens submitted to the Veterinary Diagnostic Center were evaluated by polymerase chain reaction (PCR) for detection of bovine viral diarrhea virus (BVDV). Conventional virus isolation procedures showed the specimens contained BVDV. The BVDV RNA was extracted from the homogenates and subjected to a reverse transcription reaction followed by PCR amplification. The PCR product was blotted onto a nylon membrane and hybridized with a 30-base pair oligonucleotide probe labeled with 32P. One set of PCR primers detected BVDV in 46/60 (77%) of the tissue homogenates. An additional set of primers was used to detect 10/11 samples that …

Morphometric Analysis Of Enteric Lesions In C3h/Hen Mice Inoculated With Serpulina Hyodysenteriae Serotypes 2 And 4 With Or Without Oral Streptomycin Pretreatment, Jagannatha V. Mysore, Gerald Duhamel

School of Veterinary and Biomedical Sciences: Faculty Publications

The segmental distribution and sequential progression and the role of the indigenous bacterial flora in the development of enteric lesions associated with Serpulina hyodysenteriae infection in laboratory mice have not been defined. We examined the distribution and sequential morphometric changes in the large intestine of mice orally inoculated with S. hyodysenteriae serotypes 2 and 4. To determine the role of colonization resistance conferred by the indigenous bacterial flora, 40 female C3H/HeN mice were administered water alone or water containing 5 mg/mL streptomycin sulfate ad libitum for seven days prior to orogastric inoculation either with S. hyodysenteriae or sterile trypticase soy …

Nonhomologous Rna Recombination In Tombusviruses: Generation And Evolution Of Defective Interfering Rnas By Stepwise Deletions, K. Andrew White, Thomas Jack Morris

Nebraska Center for Virology: Faculty Publications

We used a protoplast system to study the mechanisms involved in the generation and evolution of defective interfering (DI) RNAs of tomato bushy stunt tombusvirus (TBSV). Synthetic transcripts corresponding to different naturally occurring TBSV DI RNAs, or to various artificially constructed TBSV defective RNAs, were analyzed. The relative levels of competitiveness of different DI RNAs were determined by coinoculating their corresponding transcripts into protoplasts along with helper genomic RNA transcripts and monitoring the level of DI RNA accumulation. Further studies were performed to assess the contribution of naked DI RNA stability and DI RNA encapsidation efficiency to the observed levels …

Cdna Sequence For The Ribulose 1,5 Bisphosphate Carboxylase/Oxygenase Complex Protein A Protein That Accumulates In Soybean Leaves In Response To Fruit Removal, Paul E. Staswick, Steven J. Crafts-Brandner

Department of Agronomy and Horticulture: Faculty Publications

Soybean (Glycine max L.) transiently accumulates two abundant vegetative storage proteins, VSP A and VSP B, in vacuoles of above-ground vegetative tissues (Wittenbach, 1983; Staswick, 1990). As older leaves and stems become a source of exported metabolites for developing sinks, the VSPs are preferentially degraded and the resulting metabolites are presumably mobilized in the xylem and phloem stream. A striking feature of these proteins is that VSP gene expression is dramatically increased in mature leaves following the remova1 of reproductive sinks (seed pods) and the amount of these proteins increases accordingly (for review, see Staswick, 1994). Other changes …

Darcy-Weisbach Roughness Coefficients For Selected Crops, John E. Gilley, E. R. Kottwitz

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Total hydraulic resistance on an upland agricultural site may be influenced by several factors including standing vegetation. In this laboratory study, Darcy-Weisbach roughness coefficients were measured for corn, cotton, sorghum, soybeans, sunflower, and wheat vegetation. Experimental variables used in this investigation in addition to crop type included plant population, row spacing, row orientation, and flow rate. For some of the experimental tests, a single row of vegetation was oriented within a flume parallel to the principal flow direction. For the remainder of the tests, rows of vegetation were placed perpendicular to the flow using row spacings and plant populations recommended …

Water Vapor Permeability And Mechanical Properties Of Grain Protein-Based Films As Effected By Mixtures Of Polyethylene Glycol Amd Glycerin Plasticizers, H. J. Park, J. M. Bunn, Curtis L. Weller, P. J. Vergano, R. F. Testin

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Grain protein-based films containing mixtures of glycerin and polyethylene glycol (PEG) as plasticizers were prepared and evaluated for water vapor permeability (WVP), tensile strength (TS), and elongation (E). Changes in mechanical properties during storage were also studied. The PEG produced opposite trends in E of wheat gluten and corn-zein films. The TS of wheat gluten films increased and E of the films decreased as the ratio of glycerin/PEG decreased. Corn-zein films containing only glycerin were very brittle (E of 4%), and E of the films improved to 94% when the ratio of mL PEG/g protein was 0.39. The WVP of …

Long Term Tillage Effects On Grain Yield And Soil Properties In A Soybean/Grain Sorghum Rotation, Elbert C. Dickey, Paul J. Jasa, Robert Grisso

Department of Agricultural and Biological Systems Engineering: Faculty Publications

In Nebraska, early adopters of conservation tillage, especially those using no-till planting, had some concerns regarding planter performance, early season weed control, and possible yield reductions. Selected tillage and planting systems were used long term to evaluate effects on soybean [Glycine max (L.) Merr.] and grain sorghum [Sorghum bicolor (L.) Moench] yield, soil properties, and residue cover in a non-irrigated rotation. The six tillage and planting systems selected for evaluation were: no-till, no-till with row-crop cultivation, disk, double disk, chisel, and plow. In 1981, two sets of field plots were established near Lincoln, NE, on a Sharpsburg silty …

Tillage And Planting System, Stalk Chopper, And Knife Applicator Influences On Corn Residue Cover, David P. Shelton, Stephen D. Kachman, Elbert C. Dickey, K.T. Fairbanks, Paul J. Jasa

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Percent corn (Zea mays L.) residue cover remaining on the soil surface after planting was measured for 11 tillage and planting systems that included combinations of the use, and timing, of a stalk chopper and/or a knife-type fertilizer applicator. Tillage, as well as use of a stalk chopper or knife applicator, significantly reduced residue cover. Only 27 of the 69 stalk chopper/knife applicator/tillage and planting system treatment combinations that were evaluated could be classified as conservation tillage by having at least 30% residue cover remaining after planting.

Monte Carlo Calculation Of Effective Diffusivities In Two- And Three-Dimensional Heterogeneous Materials Of Variable Structure, Mark R. Riley, Fernando J. Muzzio, Helen M. Buettner, Sebastian C. Reyes

Department of Agricultural and Biological Systems Engineering: Faculty Publications

A Monte Carlo technique that simulates tracer diffusion in multiphase materials of arbitrary complexity has been developed. Effective diffusivities are calculated for structures consisting of either overlapping or nonoverlapping inclusions with diffusivity D_c, distributed in a continuous phase with diffusivity D₀>D_c. Two-dimensional simulations for various values of D₀/D_c generate normalized diffusivities that correspond closely to their three-dimensional counterparts; they nearly collapse to a common curve when a simple scaling relation is applied.