Life Sciences Commons^™

Lady Beetles Of Nebraska, Alexander P. Cunningham, James R. Brandle, Stephen D. Danielson, Thomas E. Hunt

Department of Entomology: Faculty Publications

Lady beetles are some of the most noticeable and popular insects found in the garden and on the farm. This publication will help the farmer, gardener, or amateur naturalist to better understand and identify lady beetles found in Nebraska.

Lady beetles are in the family Caccinellidae, of which nearly all members are predators. Most lady beetles are recognizable by their black-on-red spotted pattern and hemispherical shape.

Physiological And Biochemical Responses Of Resistant And Susceptible Wheat To Injury By Russian Wheat Aphid, Lisa D. Franzen, Andrea R. Gutsche, Tiffany Heng-Moss, Leon G. Higley, Gautam Sarath, John D. Burd

Department of Entomology: Faculty Publications

We examined the physiological and biochemical responses of resistant (“Halt” and “Prairie Red”) and susceptible (“TAM 107”) wheat, Triticum aestivum L., to injury by the Russian wheat aphid, Diuraphis noxia (Mordvilko). Photosynthetic capacity was evaluated by measuring assimilation/ internal CO₂ (A/C_i) curves, chlorophyll fluorescence, chlorophyll, and nonstructural carbohydrate content. Total protein and peroxidase specific activity also were determined. No significant differences were detected in chlorophyll concentration between aphid-infested and control TAM107 plants. The aphid-infested resistant cultivars had similar or significantly higher chlorophyll concentrations compared with their respective control plants. Measurements over time showed that infested Halt plants …

Survey For Hymenopteran And Dipteran Parasitoids Of The Fall Armyworm (Lepidoptera: Noctuidae) In Chiapas, Mexico, Ramiro E. Ruiz-Najera, Jaime Molina-Ochoa, James E. Carpenter, Jorge A. Espinosa-Moreno, Jose Alfredo Ruiz-Najera, Roberto Lezama-Gutierrez, John E. Foster

Department of Entomology: Faculty Publications

A survey of hymenopteran and dipteran parasitoids of the fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith) larvae was conducted to determine their occurrence and parasitism rates in Western Chiapas, Mexico. 1247 FAW larvae were collected from whorl-stage corn cornfields in 21 locations in the region called ‘‘La Frailesca’’ in Chiapas, Mexico during the summer of 2002; 251 larvae produced parasitoids for an overall parasitism rate of 20.1%. Five braconids were recovered from FAW larvae, Rogas vaughani Muesebeck, R. laphygmae Viereck, Chelonus insularis Cresson, C. cautus Cresson, and Glyptapanteles militaris Walsh. Two ichneumonids, Neotheronia sp., and Ophion flavidus Brulle, and one …

Extraction And Characterization Of Starch From Alkaline Cooked Corn Masa, Wajira Srinanda Ratnayake, Andrew B. Wassinger, David S. Jackson

Department of Food Science and Technology: Faculty Publications

Starch granules undergo structural and morphological changes during food processing unit operations as they interact with other food ingredients. This study was conducted to isolate and characterize starch granules from corn masa. A proteolytic enzyme, thermolysin, was effective in separating and isolating starch granules from endosperm proteins present in masa. The efficiency of starch extraction using thermolysin was 74% (w/w), and subsequent analyses showed that the isolated granules were free of contaminants. Starch samples were characterized using light microscopy, SEM, DSC, and XRD. Starch granules isolated from masa had undergone internal structural changes and some granules (≈40%) lost birefringence during …

Corroborative Study On Maize Quality, Dry-Milling And Wet-Milling Properties Of Selected Maize Hybrids, Kyung-Min Lee, Timothy J. Herrman, Lloyd Rooney, David S. Jackson, Jane Lingenfelser, Kent D. Rausch, John Mckinney, Chris Iiams, Linda Byrum, Charles R. Hurburgh Jr., Lawrence A. Johnson, Steven R. Fox

Department of Food Science and Technology: Faculty Publications

A corroborative study was conducted on the maize quality properties of test weight, pycnometer density, tangential abrasive dehulling device (TADD), time-to-grind on the Stenvert hardness tester (SHT), 100-kernel weight, kernel size distribution, and proximate composition as well as maize dry- and wet-millability by six participating laboratories. Suggested operating procedures were given to compare their measurements and provide the variance structure within and between laboratories and hybrids. Partial correlation coefficient among maize quality properties varied among laboratories. The repeatability and reproducibility precision values were acceptably low for the physical quality tests, except for TADD and SHT time-to-grind measurements. The yields of …

Identification Of Escherichia Coli O157:H7 Genomic Regions Conserved In Strains With A Genotype Associated With Human Infection, Marina Steele, Kim Ziebell, Yongxiang Zhang, Andrew K. Benson, Paulina Konczy, Roger Johnson, Victor Gannon

Department of Food Science and Technology: Faculty Publications

Beta-glucuronidase-negative, sorbitol-nonfermenting isolates of Shiga toxin-producing Escherichia coli O157 comprise part of a clone complex of related enterohemorrhagic E. coli isolates. High-resolution genotyping shows that the O157 populations have diverged into two different lineages that appear to have different ecologies. To identify genomic regions unique to the most common human-associated genotype, suppression subtractive hybridization was used to identify DNA sequences present in two clinical strains representing the human lineage I O157:H7 strains but absent from two bovine-derived lineage II strains. PCR assays were then used to test for the presence of these regions in 10 lineage I strains and 20 …

Possible Use Of Foresight, Understanding, And Planning By Wolves Hunting Muskoxen, L. David Mech

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

On Ellesmere Island in 2006, arctic wolves (Canis lupus arctos) were observed making a two-pronged approach to a herd of muskoxen (Ovibos moschatus) and, on another occasion, ambushing muskoxen. Both observations seemed to provide evidence that the wolves were using foresight, understanding, and planning. Although the possible use of insight and purposiveness has been documented in captive wolves, the present report is one of the few to document the possibility that freeranging wolves use these other three mental processes.

En 2006, sur l’île Ellesmere, des loups arctiques (Canis lupus arctos) ont été observés en …

Annual Arctic Wolf Pack Size Related To Arctic Hare Numbers, L. David Mech

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

During the summers of 2000 through 2006, I counted arctic wolf (Canis lupus arctos) pups and adults in a pack, arctic hares (Lepus arcticus) along a 9 km index route in the area, and muskoxen (Ovibos moschatus) in a 250 km² part of the area near Eureka (80° N, 86° W), Ellesmere Island, Nunavut, Canada. Adult wolf numbers did not correlate with muskox numbers, but they were positively related (r² = 0.89; p < 0.01) to an arctic hare index. This is the first report relating wolf numbers to non-ungulate prey.

Pendant les étés 2000 à 2006, j’ai compté les jeunes loups arctiques et les adultes (Canis lupus arctos …

Genetic Diversity In Populations Of Xanthomonas Campestris Pv. Campestris In Cruciferous Weeds In Central Coastal California, A. Ignatov, A. Sechler, E. L. Schuenzel, I. Agarkova, B. Oliver, A. K. Vidaver, N. W. Schaad

Department of Plant Pathology: Faculty Publications

Xanthomonas campestris pv. campestris (X. campestris) infects a large number of cruciferous plants, including weeds. California has one of the largest and most diverse populations of wild cruciferous plants in the world. Although considerable information is available on the genetic diversity of X. campestris in commercial crop plants, nothing is known about the diversity in strains infecting weeds. To assess the genetic diversity among strains of X. campestris in weeds in noncultivated and cultivated areas, strains of the pathogen were isolated from populations of cruciferous weeds growing in coastal valley crop-production sites and from remote nonproduction sites along the …

Expression Analysis Of Rice Defense-Related Genes In Turfgrass In Response To Magnaporthe Grisea, Young-Ki Jo, Guo-Liang Wang, Michael J. Boehm

Department of Plant Pathology: Faculty Publications

Magnaporthe grisea (anamorph = Pyricularia grisea) causes blast on rice (Oryza sativa) and gray leaf spot on turfgrass. Gray leaf spot is a serious disease on St. Augustinegrass (Stenotaphrum secundatum), perennial ryegrass (Lolium perenne), and tall fescue (Festuca arundinacea). Virulence assays performed in this study revealed that M. grisea collected from rice could also cause disease on St. Augustinegrass and tall fescue. One rice isolate, Che86061, caused similar disease reactions on susceptible cultivars of rice and St. Augustinegrass and an incompatible interaction on resistant cultivars of both species. To explore whether …

Differential Engagement Of Tim-1 During Activation Can Positively Or Negatively Costimulate T Cell Expansion And Effector Function, Vijay K. Kuchroo, Sheng Xiao, Nader Najafian, Jay Reddy, Monica Albin, Chen Zhu, Eric Jensen, Jaimie Imitola, Thomas Korn, Ana C. Anderson, Zheng Zhang, Cristina Gutierrez, Thomas Moll, Raymond A. Sobel, Dale T. Umetsu, Hideo Yagita, Hisaya Akiba, Terry Strom, Mohamed H. Sayegh, Rosemarie H. Dekruyff, Samia J. Khoury

School of Veterinary and Biomedical Sciences: Faculty Publications

It has been suggested that T cell immunoglobulin mucin (Tim)-1 expressed on T cells serves to positively costimulate T cell responses. However, crosslinking of Tim-1 by its ligand Tim-4 resulted in either activation or inhibition of T cell responses, thus raising the issue of whether Tim-1 can have a dual function as a costimulator. To resolve this issue, we tested a series of monoclonal antibodies specifi c for Tim-1 and identifi ed two antibodies that showed opposite functional effects. One anti–Tim-1 antibody increased the frequency of antigen-specifi c T cells, the production of the proinfl ammatory cytokines IFN-γ and IL-17, …

A Protein Encoded By The Bovine Herpesvirus 1 Latency-Related Gene Interacts With Specific Cellular Regulatory Proteins, Including Ccaat Enhancer Binding Protein Alpha, Florencia Meyer, Sandra Perez, Vicki Geiser, Mark Sintek, Melissa Inman, Clinton J. Jones

Nebraska Center for Virology: Faculty Publications

Following acute infection, bovine herpesvirus 1 establishes latency in sensory neurons of trigeminal ganglia (TG). Reactivation from latency occurs periodically, resulting in the shedding of infectious virus. The latency-related (LR) RNA is abundantly expressed in TG of latently infected calves, and the expression of LR proteins is necessary for dexamethasone-induced reactivation from latency. Previously published studies also identified an alternatively spliced LR transcript which is abundantly expressed in TG at 7 days after infection and has the potential to encode a novel LR fusion protein. Seven days after infection is when extensive viral gene expression is extinguished in TG and …

Identification Of Functional Subclasses In The Dj-1 Superfamily Proteins, Ying Wei, Dagmar Ringe, Mark A. Wilson, Mary Jo Ondrechen

Department of Biochemistry: Faculty Publications

Genomics has posed the challenge of determination of protein function from sequence and/or 3-D structure. Functional assignment from sequence relationships can be misleading, and structural similarity does not necessarily imply functional similarity. Proteins in the DJ-1 family, many of which are of unknown function, are examples of proteins with both sequence and fold similarity that span multiple functional classes. THEMATICS (theoretical microscopic titration curves), an electrostatics-based computational approach to functional site prediction, is used to sort proteins in the DJ-1 family into different functional classes. Active site residues are predicted for the eight distinct DJ-1 proteins with available 3-D structures. …

A New Strategy For Assessing Selenoprotein Function: Sirna Knockdown/Knock-In Targeting The 3'-Utr, Min-Hyuk Yoo, Xue-Ming Xu, Anton A. Turanov, Bradley A. Carlson, Vadim N. Gladyshev, Dolph L. Hatfield

Department of Biochemistry: Faculty Publications

Selenocysteine insertion into protein in mammalian cells requires RNA elements in the 3'-untranslated regions (3'-UTRs) of selenoprotein genes. The occurrence of these conserved sequences should make selenoproteins particularly amenable for knockdown/knock-in strategies to examine selenoprotein functions. Herein, we utilized the 3'-UTR of various selenoproteins to knock down their expression using siRNAs and then knock in expression using constructs containing mutations within the target region. Thioredoxin reductase 1 (TR1) knockdown in a mouse kidney cell line resulted in the cells growing about 10% more slowly, being more sensitive to UV radiation, and having increased apoptosis in response to UV than control …

A Practical Approach To Phylogenomics: The Phylogeny Of Ray-Finned Fish (Actinopterygii) As A Case Study, Chenhong Li, Guillermo Ortí, Gong Zhang, Guoqing Lu

School of Biological Sciences: Faculty Publications

Background: Molecular systematics occupies one of the central stages in biology in the genomic era, ushered in by unprecedented progress in DNA technology. The inference of organismal phylogeny is now based on many independent genetic loci, a widely accepted approach to assemble the tree of life. Surprisingly, this approach is hindered by lack of appropriate nuclear gene markers for many taxonomic groups especially at high taxonomic level, partially due to the lack of tools for efficiently developing new phylogenetic makers. We report here a genome-comparison strategy to identifying nuclear gene markers for phylogenetic inference and apply it to the …

Genetic Microheterogeneity And Phenotypic Variation Of Helicobacter Pylori Arginase In Clinical Isolates, Justin Hovey, Emily Watson, Melanie Langford, Ellen Hildebrandt, Sangeetha Bathala, Jeffrey Bolland, Domenico Spadafora, George Mendz, David Mcgee

School of Biological Sciences: Faculty Publications

Background: Clinical isolates of the gastric pathogen Helicobacter pylori display a high level of genetic macro- and microheterogeneity, featuring a panmictic, rather than clonal structure. The ability of H. pylori to survive the stomach acid is due, in part, to the arginase-urease enzyme system. Arginase (RocF) hydrolyzes L-arginine to L-ornithine and urea, and urease hydrolyzes urea to carbon dioxide and ammonium, which can neutralize acid.

Results: The degree of variation in arginase was explored at the DNA sequence, enzyme activity and protein expression levels. To this end, arginase activity was measured from 73 minimally-passaged clinical isolates and six laboratory-adapted strains …

Habitat Area Affects Arthropd Communities Directly And Indirectly Through Top Predators, Örjan Östman, Nicholas W. Griffin, Jared L. Strasburg, Jennifer A. Brisson, Alan R. Templeton, Tiffany M. Knight, Jonathan M. Chase

School of Biological Sciences: Faculty Publications

Both habitat area and predators are known to affect the diversity and composition of species that live in a locality. In addition, habitat area can influence the presence of predators, indirectly affecting the diversity of prey. Thus, habitat area may influence species diversity directly and indirectly through the presence of top predators. Here we examine the effects of habitat area and predators on the species richness and composition of a foliage living arthropod community in a fragmented complex of glades (small grassland patches within a forested matrix) in the Ozark Plateau, Missouri. We find that a top predator, the eastern …

Molecular Phylogenetics Of The Phyllostomid Bat Genus Micronycteris With Descriptions Of Two New Subgenera, Calvin A. Porter, Steven R. Hoofer, Chrissy A. Cline, Federico G. Hoffmann, Robert J. Baker

School of Biological Sciences: Faculty Publications

We analyzed DNA sequence variation in the cytochrome-b gene and intron 7 of the nuclear fibrinogen, B beta polypeptide gene for 45 specimens of the bat genus Micronycteris, including all currently recognized species except M. sanborni. Phylogenetic analyses of both data sets supported 4 primary lineages within Micronycteris, which we recognize as subgenera: Leuconycteris new subgenus (M. brosseti), Micronycteris Gray (M. megalotis, M. microtis, M. matses, and M. giovanniae), Schizonycteris new subgenus (M. minuta, M. schimdtorum, and M. sanborni), and Xenoctenes Miller (M. hirsuta). …

Negative Correlation Does Not Imply A Tradeoff Between Growth And Reproduction In California Oaks, Johannes M. H. Knops, Walter D. Koenig, William J. Carmen

School of Biological Sciences: Faculty Publications

A tradeoff between growth and reproduction, often inferred from an inverse correlation between these two variables, is a fundamental paradigm of life-history evolution. Oak species provide a unique test of this relationship because different species mature acorns either in the year of pollination or in the year after pollination. This difference allows for an interspecific comparison testing whether the apparent tradeoff is causal or the result of confounding factors influencing growth and reproduction independently. Based on 13 years of data on five California oak species, we found significant negative correlations between radial growth and seed production in the three species …

Alkaline Iron(Iii) Reduction By A Novel Alkaliphilic, Halotolerant, Bacillus Sp. Isolated From Salt Flat Sediments Of Soap Lake, Jarrod Pollock, Karrie A. Weber, Joe Lack, Laurie A. Achenbach, Melanie R. Mormile, John D. Coates

School of Biological Sciences: Faculty Publications

A halotolerant, alkaliphilic dissimilatory Fe(III)-reducing bacterium, strain SFB, was isolated from salt flat sediments collected from Soap Lake, WA. 16S ribosomal ribonucleic acid gene sequence analysis identified strain SFB as a novel Bacillus sp. most similar to Bacillus agaradhaerens (96.7% similarity). Strain SFB, a fermentative, facultative anaerobe, fermented various hexoses including glucose and fructose. The fructose fermentation products were lactate, acetate, and formate. Under fructose-fermenting conditions in a medium amended with Fe(III), Fe(II) accumulated concomitant with a stoichiometric decrease in lactate and an increase in acetate and CO₂. Strain SFB was also capable of respiratory Fe(III) reduction with …

Flagellar Motility And Structure In The Hyperthermoacidophilic Archaeon Sulfolobus Solfataricus, Zalán Szabó, Musa Sani, Maarten Groeneveld, Benham Zolghadr, James Schelert, Sonja-Verena Albers, Paul H. Blum, Egbert J. Boekema, Arnold J.M. Driessen

School of Biological Sciences: Faculty Publications

Flagellation in archaea is widespread and is involved in swimming motility. Here, we demonstrate that the

structural flagellin gene from the crenarchaeaon Sulfolobus solfataricus is highly expressed in stationary-phasegrown

cells and under unfavorable nutritional conditions. A mutant in a flagellar auxiliary gene, flaJ, was

found to be nonmotile. Electron microscopic imaging of the flagellum indicates that the filaments are composed

of right-handed helices.

Evaluation Of Metals In A Defined Medium For Pichia Pastoris Expressing Recombinant Β-Galactosidase, Bradley A. Plantz, Kenneth W. Nickerson, Stephen D. Kachman, Vicki L. Schlegel

School of Biological Sciences: Faculty Publications

Culture growth and recombinant protein yield of the Pichia pastoris GS115 methanol utilization positive system were studied in response to the types and levels of metals present in the growth medium and the supplemental salts typically used for these fermentations. Magnesium and zinc were both required to support cell growth but at significantly reduced levels compared to the control. However, supplementation with calcium, cobalt, iron, manganese, iodine, boron, and molybdenum were not required to sustain cell mass. When the medium was reformulated with only zinc and magnesium, the cells grew to 12–15 generations, which are expected for high cell density …

Asymmetric Localizations Of Lin-17/Fz And Mig-5/Dsh Are Involved In The Asymmetric B Cell Division In C. Elegans, Mingfu Wu, Michael A. Herman

School of Biological Sciences: Faculty Publications

LIN-44/Wnt and LIN-17/Frizzled (Fz) function in a planar cell polarity (PCP)-like pathway to regulate the asymmetric B cell division in Caenorhabditis elegans. We observed asymmetric localization of LIN-17/Frizzled (Fz) and MIG-5/Disheveled (Dsh) during the B cell division. LIN-17∷GFP was asymmetrically localized within the B cell prior to and after the B cell division and correlated with B cell polarity. Asymmetric localization of LIN-17∷GFP was dependent upon LIN-44/Wnt and MIG-5/Dsh function. The LIN-17 transmembrane domain and a portion of the cysteine-rich domain (CRD) were required for LIN-17 function and asymmetric distribution to the B cell daughters, while the conserved KTXXXW …

Lupine Allergy: Not Simply Cross-Reactivity With Peanut Or Soy, Kim A. B. M. Peeters, Julie A. Nordlee, André H. Penninks, Lingyun Chen, Richard E. Goodman, Carla A. F. M. Bruijnzeel-Koomen, Sue L. Hefle, Steve L. Taylor, André C. Knulst

Department of Food Science and Technology: Faculty Publications

Background: Reports of lupine allergy are increasing as its use in food products increases. Lupine allergy might be the consequence of cross-reactivity after sensitization to peanut or other legumes or de novo sensitization. Lupine allergens have not been completely characterized.

Objectives: We sought to identify allergens associated with lupine allergy, evaluate potential cross-reactivity with peanut, and determine eliciting doses (EDs) for lupine allergy by using double-blind, placebo-controlled food challenges.

Methods: Six patients with a history of allergic reactions to lupine flour were evaluated by using skin prick tests, CAP tests, and double-blind, placebo-controlled food challenges. Three of …

First Record Of Alcataenia Larina Larina (Cestoda: Dilepididae) In Atlantic Puffins (Aves, Alcidae, Fratercula Arctica) From Newfoundland, Canada, Sabir B. Muzaffar, Eric P. Hoberg, Ian L. Jones

Harold W. Manter Laboratory of Parasitology: Faculty Publications

The tapeworm Alcataenia larina (Cestoda: Cyclophyllidea: Dilepididae) is a parasite of gulls (Laridae) with a Holarctic distribution in oceanic and littoral habitats. Two subspecies Alcataenia larina pacifica and Alcataenia larina larina are recognized with the former occurring in the North Pacific basin and the latter in the North Atlantic. Alcids serve as incidental hosts for both species and infections are generally rare, usually involving few specimens. We report A. l. larina in Atlantic puffins (Fratercula arctica) collected from the Bay of Exploits, Newfoundland. The 14 strobilate and early gravid specimens were clearly distinguishable from the closely related Alcataenia …

Genetic Analysis Of A Novel Alaska Barley Yellow Dwarf Virus In The Family Luteoviridae, N.L. Robertson, Roy C. French

Department of Plant Pathology: Faculty Publications

A new plant virus belonging to the family Luteoviridae and isolated from diseased oat (Avena sativa L.) plants was discovered in Alaska in 2003. Even though plants with red/orange leaves were indicative of barley yellow dwarf disease, they were not reactive to specific antibodies corresponding to barley yellow dwarf virus (BYDV)-MAV, -PAV, -SGV, and cereal yellow dwarf virus-RPV from enzyme-linked immunosorbent assays (ELISA). An alternative RT-PCR assay that incorporated Shu-F/Yan-R primers for detection of BYDV-MAV, -PAS, -PAV, and SGV was effective in producing ~830-nt fragments that contained genomic sequences to the 3’-terminus of the polymerase gene (ORF 2), the …

Gene Family Encoding The Major Toxins Of Lethal Amanita Mushrooms, Heather E. Hallen-Adams, Hong Luo, John S. Scott-Craig, Jonathan D. Walton

Department of Food Science and Technology: Faculty Publications

Amatoxins, the lethal constituents of poisonous mushrooms in the genus Amanita, are bicyclic octapeptides. Two genes in A. bisporigera,AMA1 and PHA1, directly encode ∝-amanitin, an amatoxin, and the related bicyclic heptapeptide phallacidin, a phallotoxin, indicating that these compounds are synthesized on ribosomes and not by nonribosomal peptide synthetases. ∝-Amanitin and phallacidin are synthesized as proproteins of 35 and 34 amino acids, respectively, from which they are predicted to be cleaved by a prolyl oligopeptidase. AMA1 and PHA1 are present in other toxic species of Amanita section Phalloidae but are absent from nontoxic species in other sections. The …

Powerpoint On Water, Food, Energy, And Youth, Families And Communities, John Owens

John Owens: Speeches and Appearances

Thank you for this opportunity to speak with you today. It's always my pleasure to talk about the exciting work occurring in the Institute of Agriculture and Natural Resources.

Master Coqservationists Presentations - 2007, John Owens

John Owens: Speeches and Appearances

Before announcing our honorees this evening, I would like to call your attention to results of an independent study done for the Institute of Agriculture and Natural Resources at the University of Nebraska-Lincoln during the past year. The "At Work for Nebraska" study was done by Battelle, of Columbus, Ohio, which is a nonprofit research and development organization specializing in global science and technology. The independent study found that our Institute provides a 15-to-one return on every tax dollar invested with us. That's 15-to-one conservatively. We all wish we could get that return on all our own investments. I encourage …

Distinguished Fellowship Awards Luncheon, John Owens

John Owens: Speeches and Appearances

What a great pleasure it is to see everyone gathered for this distinguished fellowship awards luncheon. My heartiest congratulations to each of you who is a fellowship recipient. I know all of us here today are so pleased for you, and so pleased to have you with us.