Digital Commons Network^™

Evaluation Of Resistance Screening Methods For Sclerotinia Stem Rot Of Soybean And Dry Bean, Linda S. Kull, Tri D. Vuong, Kris S. Powers, Kent M. Eskridge, James R. Steadman, Glen L. Hartman

Department of Plant Pathology: Faculty Publications

Three methods to identify levels of resistance to Sclerotinia sclerotiorum in soybean (Glycine max) and dry bean (Phaseolus vulgaris) were compared using multiple data analyses. The three methods were mycelial plug inoculations of cotyledons, cut stems, and detached leaves. Six S. sclerotiorum isolates of known relative aggressiveness were inoculated on each of three soybean and dry bean cultivars with varied response to S. sclerotiorum. For soybean, all three inoculation methods accurately identified isolate aggressiveness irrespective of cultivar, but identification of susceptible and partially resistant soybean cultivars was influenced by isolate. For dry bean, the cotyledon and cut …

Osmosensitive Taurine Release: Does Taurine Share The Same Efflux Pathway With Chloride And Other Amino Acid Osmolytes?, Rodrigo Franco

School of Veterinary and Biomedical Sciences: Faculty Publications

Swelling subsequent to hyposmotic conditions activates a process of volume regulation present in most cell types. This volume adjustment is accomplished by osmolyte translocation toward the extracellular space to reach a new osmotic equilibrium. Molecules involved in this homeostatic mechanism have been broadly classified into two categories: organic and inorganic osmolytes. Inorganic osmolytes comprise mainly the intracellular ions K⁺ and Cl^–. Cell swelling–induced activation of separate K⁺ and Cl^– channels has been described in most preparations. Organic osmolytes are grouped in three categories: amino acids, polyalcohols, and methylamines. These osmolytes, particularly taurine, are present in …

Role Of Activator Protein-1 In The Down-Regulation Of The Human Cyp2j2 Gene In Hypoxia, Nicole Y. Marden, Eva Fiala-Beer, Shi-Hua Xiang, Michael Murray

School of Veterinary and Biomedical Sciences: Faculty Publications

The cytochrome P450 (CYP) 2J2 arachidonic acid epoxygenase gene was down-regulated at a pre-translational level in human hepatoma-derived HepG2 cells incubated in a hypoxic environment; under these conditions, the expression of c-Jun and c-Fos mRNA and protein was increased. The 5′-upstream region of the CYP2J2 gene was isolated by amplification of a 2341 bp fragment and putative regulatory elements that resembled activator protein-1 (AP-1)-like sequences were identified. From transient transfection analysis, c-Jun was found to strongly activate a CYP2J2–luciferase reporter construct, but co-transfection with plasmids encoding c-Fos or c-Fos-related antigens, Fra-1 and -2, abrogated reporter activity. Using a series …

Mucosal Priming Of Simian Immunodeficiency Virus-Specific Cytotoxic T-Lymphocyte Responses In Rhesus Macaques By The Salmonella Type Iii Secretion Antigen Delivery System, David T. Evans, Li-Mei Chen, Jacqueline Gillis, Kuei-Chin Lin, Brian Harty, Gail P. Mazzara, Ruben O. Donis, Keith G. Mansfield, Jeffrey D. Lifson, Ronald C. Desrosiers, Jorge E. Galán, R. Paul Johnson

School of Veterinary and Biomedical Sciences: Faculty Publications

Nearly all human immunodeficiency virus (HIV) infections are acquired mucosally, and the gut-associated lymphoid tissues are important sites for early virus replication. Thus, vaccine strategies designed to prime virus-specific cytotoxic T lymphocyte (CTL) responses that home to mucosal compartments may be particularly effective at preventing or containing HIV infection. The Salmonella type III secretion system has been shown to be an effective approach for stimulating mucosal CTL responses in mice. We therefore tested ∆phoP-phoQ attenuated strains of Salmonella enterica serovar Typhimurium and S. enterica serovar Typhi expressing fragments of the simian immunodeficiency virus (SIV) Gag protein fused to the …

Method To Detect The Presence Of A Microorganism Or Agent In An Animal, David R. Smith, Laura L. Hungerford, Rodney A. Moxley, Susanne Hinkley, Terry Klopfenstein, Jeff Gray

School of Veterinary and Biomedical Sciences: Faculty Publications

The present invention provides a method to detect the presence of a microorganism or agent in an animal. The method encompasses placement of devices at various locations where the animal resides so as to induce the animal to initiate contact with the device. As a result of this contact, the animal deposits various microorganisms and agents on the device. The device is then tested for the presence of the particular microorganism or agent of interest.

The Coat Protein Of Turnip Crinkle Virus Suppresses Posttranscriptional Gene Silencing At An Early Initiation Step, Feng Qu, Tao Ren, Thomas Jack Morris

Nebraska Center for Virology: Faculty Publications

Posttranscriptional gene silencing (PTGS), or RNA silencing, is a sequence-specific RNA degradation process that targets foreign RNA, including viral and transposon RNA for destruction. Several RNA plant viruses have been shown to encode suppressors of PTGS in order to survive this host defense. We report here that the coat protein (CP) of Turnip crinkle virus (TCV) strongly suppresses PTGS. The Agrobacterium infiltration system was used to demonstrate that TCV CP suppressed the local PTGS as strongly as several previously reported virus-coded suppressors and that the action of TCV CP eliminated the small interfering RNAs associated with PTGS. We have also …

Roles Of Mycobacterium Smegmatis D-Alanine:D-Alanine Ligase And D-Alanine Racemase In The Mechanisms Of Action Of And Resistance To The Peptidoglycan Inhibitor D-Cycloserine, Zhengyu Feng, Raul G. Barletta

School of Veterinary and Biomedical Sciences: Faculty Publications

D-Cycloserine (DCS) targets the peptidoglycan biosynthetic enzymes D-alanine racemase (Alr) and Dalanine: D-alanine ligase (Ddl). Previously, we demonstrated that the overproduction of Alr in Mycobacterium smegmatis determines a DCS resistance phenotype. In this study, we investigated the roles of both Alr and Ddl in the mechanisms of action of and resistance to DCS in M. smegmatis. We found that the overexpression of either the M. smegmatis or the Mycobacterium tuberculosis ddl gene in M. smegmatis confers resistance to DCS, but at lower levels than the overexpression of the alr gene. Furthermore, a strain overexpressing both the alr and ddl …

Herpes Simplex Virus Type 1 And Bovine Herpesvirus 1 Latency, Clinton J. Jones

School of Veterinary and Biomedical Sciences: Faculty Publications

A high percentage of the world’s population are infected with herpes simplex virus type 1 (HSV-1), and infection can cause a variety of disorders (35, 187). Recurrent ocular HSV-1 is the leading cause of infectious corneal blindness in industrialized nations (190). In a murine model, ocular infection induces autoimmune disorders, leading to corneal antigen destruction and stromal keratitis (275). HSV-1 infections also cause gastrointestinal disorders, esophageal disorders, and approximately 25% of the genital herpes infections (67, 158). HSV-1 infections can cause sporadic encephalitis, but this is relatively rare compared to other diseases resulting from infection. Further evidence for its involvement …

Monitoring Trends In Bat Populations Of The United States And Territories: Status Of The Science And Recommendations For The Future, Thomas J. O'Shea, Michael A. Bogan, Laura E. Ellison

United States Geological Survey: Staff Publications

Populations of bats (Order Chiroptera) are difficult to monitor. However, current recognition of the importance of bats to biodiversity, their ecological and economic value as ecosystem components, and their vulnerability to declines makes monitoring trends in their populations a much-needed cornerstone for their future management. We report findings and recommendations of a recent expert workshop on monitoring trends in bat populations in the United States and territories. We summarize selected case reports presented by others at the workshop, including reviews of methods and ongoing efforts to monitor a wide range of species of bats in a diverse array of situations. …

Public Knowledge And Perceptions Of Black-Tailed Prairie Dogs, Berton Lee Lamb, Kurt Cline

United States Geological Survey: Staff Publications

Black-tailed prairie dogs (Cynomys ludovicianus) historically occupied an 11-state region of the United States. We surveyed 1,900 residents (response rate 56%) of this region to understand citizen knowledge and perceptions about prairie dogs and their management. Those who have direct experience— e.g., those who live very close to prairie dog colonies or know the location of the nearest colony—have higher levels of knowledge. A significantly higher level of knowledge was documented among those who were politically active when compared with the general public. Those who found environmental issues difficult to understand were associated with lower knowledge. People with …

Nebraska Birds In Recorded History, Fritz L. Knopf

United States Geological Survey: Staff Publications

The critical image of historical perspective is lacking in much of conservation biology's dialogue on protecting biotic diversity. Some biologists offer that the vision for bird conservation on the Central Grasslands of North America is to secure at least fragments of the avian assemblage that coexisted with Native Americans when Europeans first arrived. Nowhere, however, has anyone really tried to re-create such a historical image in any biological arena, until now.

Differences In Habitat Use By Blanding’S Turtles, Emydoidea Blandingii, And Painted Turtles, Chysemys Picta, In The Nebraska Sandhills, R. Bruce Bury, David J. Germano

United States Geological Survey: Staff Publications

We sampled a variety of wetlands in the Nebraska sandhills at Valentine National Wildlife Refuge. Significantly more individuals of painted turtles (Chrysemys picta) occurred in lakes and open waters than in marshes or small ponds, and the opposite was true for Blanding’s turtles (Emydoidea blandingii). Besides this marked difference in habitat use, 46% of the captured E. blandingii in pond/marsh habitat were juveniles, but only 31.6% in lakes and open water. Current information suggests that marshes and small ponds are important habitat for juvenile turtles, especially Emydoidea blandingii.

Influence Of Nitrogen And Duration Of Weed Interference On Corn Growth And Development, Sean P. Evans, Stevan Z. Knezevic, John L. Lindquist, Charles A. Shapiro

Department of Agronomy and Horticulture: Faculty Publications

An improved understanding of the effects of nitrogen (N) on crop–weed interactions is needed for the development of integrated weed management systems where responsible use of N fertilizers is considered. Field experiments conducted in 1999 and 2000 at two locations in eastern Nebraska quantify the effects of N and increasing duration of weed interference on corn growth and development. A naturally occurring population of weeds was allowed to compete with the corn crop for increasing lengths of time and at three rates of N application (0, 60, and 120 kg N ha^-1). Weed interference and withholding applied N …

The S-Locus And Unilateral Incompatibility, C. Nathan Hancock, Katsuhiko Kondo, Brian Beecher, Bruce Mcclure

Department of Agronomy and Horticulture: Faculty Publications

Plants have many ways to regulate the type of pollen that arrives on the stigma surface. Once there, further control mechanisms regulate compatibility. The latter controls are largely based on biochemical interactions that support compatible pollination and prevent incompatible matings. S-RNase-based selfincompatibility (SI) systems are the most phylogenetically widespread mechanisms for controlling pollination. Studies of Nicotiana establish a firm link between SI and unilateral interspecific incompatibility. Although implicated in both inter- and intraspecific compatibility, S-RNase operates through at least three distinct genetic mechanisms that differ in their dependence on non-S-RNase factors. Identification and characterization of these non-S-RNase factors is currently …

Comparison And Hybridization Of Two Approaches For Maize Simulation, Haishun Yang, Kenneth G. Cassman, Achim R. Dobermann, Daniel T. Walters, John L.. Lindquist, Timothy J. Arkebauer

Department of Agronomy and Horticulture: Faculty Publications

Two approaches dominate simulation modeling of maize growth: (1) a generic approach, represented by the family of crop models developed by Dutch scientists at the Wageningen University, e.g. SUCROS (Spitters et al, 1989), WOFOST (Diepen et al, 1989) and INTERCOM (Kropff and van Laar, 1993), and (2) a maize-specific approach, represented by CERES-Maize (Jones and Kiniry, 1986) and its derivatives such as the maize module in DSSAT, and the MSB model developed by Muchow et al. (Muchow et al, 1990). These two approaches differ in three aspects. First, maize development in generic models is driven primarily by availability of …

Greenhouse Gas Emissions And Soil Indicators Four Years After Manure And Compost Applications, Daniel Ginting, Anabayan Kessavalou, Bahman Eghball, John W. Doran

Department of Agronomy and Horticulture: Faculty Publications

Understanding how carbon, nitrogen, and key soil attributes affect gas emissions from soil is crucial for alleviating their undesirable residual effects that can linger for years after termination of manure and compost applications. This study was conducted to evaluate the emission of soil CO₂, N₂O, and CH₄ and soil C and N indicators four years after manure and compost application had stopped. Experimental plots were treated with annual synthetic N fertilizer (FRT), annual and biennial manure (MN1 and MN2, respectively), and compost (CP1 and CP2, respectively) from 1992 to 1995 based on removal of 151 …

Registration Of ‘Ne422t’ Winter Triticale, P. Stephen Baenziger, K. P. Vogel

Department of Agronomy and Horticulture: Faculty Publications

NE422T triticale (X Triticosecale Wittmack) (Reg. no CV-27, PI 629028) was developed cooperatively by the Nebraska Agricultural Experiment Station and the USDA-ARS. It was jointly released in 2001 by the developing institutions. NW422T was selected from the cross ‘Trical’/‘UB-UW26’ where Trical is most likely ‘Trical 100’ (a forage triticale developed by Resource Seed Inc., a subsidiary of Goldsmith Seed Company, Gilroy, CA) and UB-UW26 is an unknown winter triticale germplasm line given to the breeding program in the 1980s.The cross was made in 1990. The F₁ generation was grown in the greenhouse in 1990-1991. The F₂ and F …

Application And Performance Of Constructed Wetlands For Runoff From Small Open Lots, C. G. Henry, J. P. Harner Iii, T. D. Strahm, M. A. Reynolds

Department of Agricultural and Biological Systems Engineering: Presentations and White Papers

Vegetative systems have long been studied and evaluated as alternatives to conventional storage, treatment, and land application systems. This paper discusses the application of vegetative systems, primarily constructed wetlands, as a runoff treatment technology for small livestock operations. The approach used for two small dairies and one beef cattle feedlot is discussed. Cost data for these operations is included as well as nutrient reduction performance results from a three year sampling period for the KS Dairy.

Molecular Dynamics Of Soy-Protein Isolate Films Plasticized By Water And Glycerol, S.-G. Choi, K. M. Kim, Milford Hanna, Curtis L. Weller, W. L. Kerr

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The effects of water and glycerol on the molecular mobility of a soy-protein isolate (SPI)-based film were investigated using ¹H nuclear magnetic resonance (NMR). SPI-films were prepared with different glycerol contents and equilibrated to various levels of water activity (a_w). The distributed transverse relaxation of film samples showed 2 distinct components: a solid-like fraction (T_2s*) and a liquid-like fraction (T_2m*). The peak T_2s* values of films with lower glycerol concentration were more sensitive to variation in aw. As a_w increased, the change of solid-like to liquid-like fraction was observed in …

Influence Of Sorghum Wax, Glycerin, And Sorbitol On Physical Properties Of Soy Protein Isolate Films, Ki Myong Kim, David B. Marx, Curtis Weller, Milford Hanna

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Sorghum wax, sorbitol, glycerin, and soy protein isolate (SPI) composite films were prepared. Effects of sorghum wax, sorbitol, and glycerin concentrations on various films were evaluated using response surface methodology. All independent variables significantly (P < 0.05) affected film water vapor permeability (WVP), tensile strength (TS), elongation at break (E), total color difference, and total soluble matter (TSM). Increasing the sorghum wax concentration decreased WVP and E. As sorbitol content increased in the composite films, WVP and TS increased. Sorbitol had a critical point of 2–5 g/5 g SPI for low values of TSM. The addition of sorbitol contributed more to the properties of the film than did glycerin.

A Comparative Analysis Of Social Play In Birds, Judy Diamond, Alan B. Bond

Papers in Behavior in Biological Sciences

Although social play is broadly distributed among mammals, it is infrequently encountered in other vertebrate taxa. It is, however, displayed in a fully realized and complex form in several groups of birds. Unambiguous accounts of social play have been recorded from thirteen species of parrots, seven species of corvids, and several hornbills and Eurasian babblers. We conducted an analysis of the avian play literature, testing for differences between avian taxa, as well as for correlations between play complexity, brain size, and age of first reproduction. Corvids were far more likely to show social object play than parrots. Corvids, parrots, and …

Social Complexity And Transitive Inference In Corvids, Alan B. Bond, Alan Kamil, Russell P. Balda

Papers in Behavior in Biological Sciences

The social complexity hypothesis asserts that animals living in large social groups should display enhanced cognitive abilities along predictable dimensions. To test this concept, we compared highly social pinyon jays, Gymnorhinus cyanocephalus, with relatively nonsocial western scrub-jays, Aphelocoma californica, on two complex cognitive tasks relevant to the ability to track and assess social relationships. Pinyon jays learned to track multiple dyadic relationships more rapidly and more accurately than scrub-jays and appeared to display a more robust and accurate mechanism of transitive inference. These results provide a clear demonstration of the association between social complexity and cognition in animals.

A Phylogenetic Study Of Cytochrome B561 Proteins, Wim Verelst, Han H. Asard

Department of Biochemistry: Faculty Publications

Background: As an antioxidant and cofactor to numerous metabolic enzymes, ascorbate has an essential role in plants and animals. Cytochromes b561 constitute a class of intrinsic membrane proteins involved in ascorbate regeneration. Despite their importance in ascorbate metabolism, no evolutionary analysis has been presented so far on this newly described protein family. Results: Cytochromes b561 have been identified in a large number of phylogenetically distant species, but are absent in fungi and prokaryotes. Most species contain three or four cytochrome b561 paralogous proteins, and the encoding genes usually have four or five exons. At the protein level, sequence similarities are …

Functional Copper At The Acetyl-Coa Synthase Active Site, Javier Seravalli, Welwel Gu, Annie Tam, Erick Strauss, Stephen P. Cramer, Stephen W. Ragsdale

Department of Biochemistry: Faculty Publications

The bifunctional CO dehydrogenase/acetyl-CoA synthase (CODH/ACS) plays a central role in the Wood–Ljungdahl pathway of autotrophic CO₂ fixation. A recent structure of the Moorella thermoacetica enzyme revealed that the ACS active site contains a [4Fe-4S] cluster bridged to a binuclear Cu-Ni site. Here, biochemical and x-ray absorption spectroscopic (XAS) evidence is presented that the copper ion at the M. thermoacetica ACS active site is essential. Depletion of copper correlates with reduction in ACS activity and in intensity of the ‘‘NiFeC’’ EPR signal without affecting either the activity or the EPR spectroscopic properties associated with CODH. In contrast, Zn content …

Transmembrane Movement Of Exogenous Long-Chain Fatty Acids: Proteins, Enzymes, And Vectorial Esterification, Paul N. Black, Concetta C. Dirusso

Department of Biochemistry: Faculty Publications

INTRODUCTION......................................................................................................................................................454

FATTY ACIDS AND BIOLOGICAL MEMBRANES.............................................................................................455

Fatty Acid Transport Defined ...............................................................................................................................456

MODEL SYSTEMS TO INVESTIGATE FATTY ACID TRANSPORT ..............................................................456

Genetic Foundations of Fatty Acid Transport....................................................................................................456

PROTEINS IMPLICATED IN FATTY ACID TRANSPORT ...............................................................................456

Fatty Acid Translocase..........................................................................................................................................457

Fatty Acid Binding Protein—Membrane Bound ................................................................................................457

Fatty Acid Transport Protein...............................................................................................................................458

The Long-Chain Fatty Acid Transport Protein FadL .......................................................................................458

Fatty Acyl-CoA Synthetase ...................................................................................................................................459

VECTORIAL ACYLATION: ONE MECHANISM OPERATIONAL IN FATTY ACID TRANSPORT...........460

THE BACTERIAL PARADIGM ...............................................................................................................................460

Energetics of Fatty Acid Transport in Gram-Negative Bacteria......................................................................460

The Fatty Acid Transporter FadL........................................................................................................................461

The Fatty Acyl-CoA Synthetase FadD..................................................................................................................461

Structural Considerations of FACS .....................................................................................................................462

FATTY ACID TRANSPORT AND ACTIVATION IN YEAST: …

The Many Faces Of Vitamin B12: Catalysis By Cobalamin-Dependent Enzymes, Ruma Banerjee, Stephen W. Ragsdale

Department of Biochemistry: Faculty Publications

Vitamin B₁₂ is a complex organometallic cofactor associated with three subfamilies of enzymes: the adenosylcobalamin-dependent isomerases, the methylcobalamin-dependent methyltransferases, and the dehalogenases. Different chemical aspects of the cofactor are exploited during catalysis by the isomerases and the methyltransferases. Thus, the cobalt-carbon bond ruptures homolytically in the isomerases, whereas it is cleaved heterolytically in the methyltransferases. The reaction mechanism of the dehalogenases, the most recently discovered class of B₁₂ enzymes, is poorly understood. Over the past decade our understanding of the reaction mechanisms of B₁₂ enzymes has been greatly enhanced by the availability of large amounts of enzyme …

Joint Effects Of Population Density And Toxicant Exposure On Population Dynamics Of Capitella Sp. I, Valery E. Forbes, Richard M. Sibly, Inez Linke-Gamenick

Valery Forbes Publications

Very few studies have analyzed the dependence of population growth rate on population density, and even fewer have considered interaction effects of density and other stresses, such as exposure to toxic chemicals. Yet without such studies we cannot know whether chemicals harmful at low density have effects on carrying capacity or, conversely, whether chemicals reducing carrying capacity are also harmful at low density, impeding a population’s capacity to recover from disturbance. This study examines the combined effects of population density and a toxicant (fluoranthene) on population growth rate (pgr) and carrying capacity using the deposit-feeding polychaete Capitella sp. I as …

Long-Term Effect Of Sea-Nine On Natural Coastal Phytoplankton Communities Assessed By Pollution Induced Community Tolerance, Dorthe K. Larsen, Inge Wagner, Kim Gustavson, Valery E. Forbes, Torben Lund

Valery Forbes Publications

Sea-Nine™211 has been introduced as a new biocide in antifouling paints with an immediate deg­radation when it is released from ship hulls. The active component of Sea-Nine™211 is 4,5-di­chloro-2-n-octyl-isothiazoline-3-one (DCOI). In the present study, the toxicity of DCOI and the oc­currence of Pollution Induced Community Tolerance (PICT) were tested in microcosms containing eutrophic coastal water with its natural composition of phytoplankton. The experiment was per­formed in closed systems with a single addition of the nominal concentrations 0, 3.2, 10, 32 and 100 nM DCOI, for a period of 16 days. Pollution induced community tolerance (PICT) was observed in the phytoplankton …

Impact Of Fire Management On The Ecology Of Collared Lizard (Crotaphytus Collaris) Populations Living On The Ozark Plateau, Jennifer A. Brisson, Jared L. Strasburg, Alan R. Templeton

School of Biological Sciences: Faculty Publications

Eastern collared lizards (Crotaphytus collaris collaris) on the Ozark Plateau of southern Missouri are restricted to islands of rocky glade habitat located throughout the oak–hickory forests of the region. Human mediated suppression of fire negatively impacts collared lizard populations by permitting the overgrowth and consequent disappearance of this glade habitat and also leads to a dense forest understorey that impedes movement of lizards between glades. We present data examining the effects of a fire management regime on collared lizard populations we monitored via mark/recapture from 1998 to 2001. We demonstrate increased glade-to-glade dispersal, colonization of previously unoccupied glades, …

Native Thistles: Expendable Or Integral To Ecosystem Resistance To Invasion?, Svata M. Louda, Tatyana A. Rand

School of Biological Sciences: Faculty Publications

One way of addressing the question of whether some species are expendable is to ask what role, if any, a minor species, even one that seems obnoxious, plays in the functioning of its community. Thistles (Cirsium spp.) are prickly plants native to North America that are numerically minor and are often considered unattractive or undesirable. So, thistles might be considered expendable. Yet, can we assume that such minor, seemingly undesirable species can be elirninated without disrupting important interdependencies or losing key ecological services? Our long-term studies of thistle-insect interactions are beginning to provide evidence that even such species may …