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Introduction From The Changing Prairie: North American Grasslands, Anthony Joern, Kathleen H. Keeler

School of Biological Sciences: Faculty Publications

Preserving remaining North American grasslands requires a multiability approach. In this book, we investigate three aspects of an admittedly larger problem: (1) how we as humans perceive grasslands; (2) the ecology of grasslands, in order to define the framework within which conservation and preservation efforts must operate; and (3) conservation issues. Additional sociological, economic, philosophical, and cultural considerations will provide important additional insights to preserving and managing grasslands, but are not included here. By restricting our focus to only three issues, we feel that we can provide a basic, but appropriate, understanding of grassland ecosystems for the prairie enthusiast. This …

Population Processes, Kathleen H. Keeler, Anthony Joern

School of Biological Sciences: Faculty Publications

Within the prairies, myriad populations of plants, insects, small mammals, and other organisms form distinct levels of organization. The physical forces of weather and fire and the complex networks of species interactions control each species’s structure and dynamics and determine its abundance or rarity. Variation in population dynamics and interactions over time and space determine the distribution and abundance of species, and ultimately the composition and dynamics of entire prairie communities.

To the casual observer, plant populations on prairies may seem quite static, like museums containing a diverse collection of specimens that can be seen again and again on repeated …

Preface From The Changing Prairie: North American Grasslands, Kathleen H. Keeler, Anthony Joern

School of Biological Sciences: Faculty Publications

North American grasslands have figured prominently in our North American heritage. Prairies first provided significant barriers to westward expansion, and then offered both economic and sociological opportunity, as well as heartache, for settlers. Many artists have gained significant inspiration from the beauty as well as the harshness of this region and its biota. And because of ideal climate and soil conditions, these grasslands have provided the agricultural foundation of which much of the economic growth and stability of the United States has historically depended.

Yet many see North American prairies as beautiful only when manipulated or exploited: Green croplands or …

Rna Determinants Of Junction Site Selection In Rna Virus Recombinants And Defective Interfering Rnas, K. Andrew White, Thomas Jack Morris

School of Biological Sciences: Faculty Publications

RNA recombination plays an important role in the diversification and evolution of RNA viruses. Most of these events are believed to be mediated by an actively copying viral replicase switching from a donor template to an acceptor template, where it resumes synthesis. In addition, Intramolecular replicase-mediated events (I.e., rearrangements) can lead to the generation of replicable deleted forms of a viral genome, termed defective interfering (DI) RNAs. To gain further insight into the recombination process, the effect of various primary and secondary structures on recombination site selection in vivo was examined using plant RNA tombusviruses. The effect of sequence Identity …

The Majority Of Yeast Upf1 Co-Localizes With Polyribosomes In The Cytoplasm, Audrey L. Atkin, Nicola Altamura, Peter Leeds, Michael R. Culbertson

School of Biological Sciences: Faculty Publications

In Saccharomyces cerevisiae the UPF1 protein is required for nonsense-mediated mRNA

decay, the accelerated turnover of mRNAs containing a nonsense mutation. Several lines

of evidence suggest that translation plays an important role in the mechanism of

nonsense mRNA decay, including a previous report that nonsense mRNAs assemble in

polyribosomes. In this study we show that UPF1 and ribosomal protein Li co-localize in

the cytoplasm and that UPF1 co-sediments with polyribosomes. To detect UPF1, three

copies of the influenza hemagglutinin epitope were placed at the C-terminus. The tagged

protein, UPF1-3EP, retains 86% (± 5%) of function. Using immunological detection, we

found …

Purification, Characterization, And Submitochondrial Localization Of A 58-Kilodalton Nad(P)H Dehydrogenase, Michael H. Luethy, Jay J. Thelen, Andrew F. Knudten, Thomas Elthon

School of Biological Sciences: Faculty Publications

An NADH dehydrogenase activity from red beet (Beta vulgaris 1.) root mitochondria was purified to a 58-kD protein doublet. An immunologically related dehydrogenase was partially purified from maize (Zea mays L. 873) mitochondria to a 58-kD protein doublet, a 45-kD protein, and a few other less prevalent proteins. Polyclonal antibodies prepared against the 58-kD protein of red beet roots were found to immunoprecipitate the NAD(P)H dehydrogenase activity. The antibodies cross-reacted to similar proteins in mitochondria from a number of plant species but not to rat liver mitochondrial proteins. The polyclonal antibodies were used in conjunction with maize mitochondrial fractionation to …

Isolation, Sequencing, And Analysis Of A 14-3-3 Brain Protein Homolog From Pea (Pisum Sativum L.), Bratislav Stankovic, Ana Garit-Stankovic, Christopher M. Smith, Eric Davies

School of Biological Sciences: Faculty Publications

Initially identified as acidic, homodimeric proteins abundantly and preferentially present in mammalian brain neurotransmitter complexes, the eukaryotic 14-3-3 homologs appear to be ubiquitous and highly conserved among highly diverse organisms, including Xenopus, Drosophila, and Saccharomyces (Aitken et al., 1992). They have also been isolated, cloned, and sequenced from various plants, such as Arabidopsis (Lu et al., 1992), Oenotkera, Spinacea (Hirsch et al., 1992), Zea (De Vetten et al., 1992), Lycopersicon (Laughner et al., 19941, Hordeum (Brandt et al., 19921, and Oyza (Kidou et al., 1993). Although there are no available sequence data in the GenBank (version 94-5), immunoprecipitation experiments suggest …

Interaction Of Diffuse Competition And Insect Herbivory In Limiting Brittle Prickly Pear Cactus, Opuntia Fragilis (Cactaceae), Jutta C. Burger, Svata M. Louda

Svata M. Louda Publications

We tested the effects of above- and below-ground competition and evaluated insect herbivory on the growth of a common cactus (Opuntia fragilis) in Sandhills prairie. Our purpose was to determine the independent and joint contribution of these factors to the variation observed in cactus size and local abundance. We manipulated ambient prairie vegetation and surface water availability in a full factorial design. When Opuntia fragilis was released from competition with surrounding vegetation, it grew significantly larger in the second growing season, both in terms of number and size of new cladodes. Ramets grown within live prairie vegetation averaged …

Genetic Structure Of Midwestern Ascaris Suum Populations: A Comparison Of Isoenzyme And Rapd Markers, Steven A. Nadler, Rachel L. Lindquist, Thomas J. Near

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Isoenzyme and random amplified polymorphic DNA (RAPD) markers were used to characterize the genetics of geographic variation among population samples of Ascaris suum from midwestern localities. Independent estimates of fixation indices (F_ST) based on isoenzyme and RAPD markers showed the same general patterns of differentiation and substantial statistical correlation (r=0.70). Of the total estimated gene diversity, 9.4% (isoenzyme) and 9.2% (RAPD) was distributed among infrapopulations. Geographic localities accounted for 7.8% (isoenzyme) and 6.2% (RAPD) of the total gene diversity. Only infrapopulations and localities, which indicates significant population subdivision among A. suum from farms within geographic regions. Departures from …

Microevolution And The Genetic Structure Of Parasite Populations, Steven A. Nadler

Harold W. Manter Laboratory of Parasitology: Faculty Publications

The development of polymerase chain reaction-based methods for assessing the genotypes of small individual organisms will promote groundbreaking investigations of the genetic architecture of parasite populations. Both quantitative genetic models and general knowledge of parasite natural history are useful for making general predictions about the distribution of genetic variation over geographic space. However, designing experimental studies to assess relationships between specific life history variables and patterns of genetic structure in natural populations will be challenging. Traditional biochemical-genetic methods have already been used to study a limited number of parasite populations, and inferred patterns of genetic structure are distinctly different between …

Critical Comments: Parasitology Year 2000, Albert O. Bush, Janine N. Caira, Dennis J. Minchella, Steven A. Nadler, John R. Seed

Harold W. Manter Laboratory of Parasitology: Faculty Publications

We predict that in order for parasitology to thrive by the year 2000 the various subdisciplines of evolution, ecology, biosystematics, and genetics must develop holistic approaches and use parasite models to answer basic biological questions. The students of tomorrow must work as part of a multidisciplinary team; and their questions and answers must be conceptually integrated into the broader biological framework of evolution and ecology.

Comparative Morphology Of The Scolices And Microtriches Among Five Species Of Tetrabothrius (Eucestoda: Tetrabothriidae), Eric P. Hoberg, D. E. Sims, P. H. Odense

Harold W. Manter Laboratory of Parasitology: Faculty Publications

The structure of the scolex, neck, and adjacent strobila of 5 species of Tetrabothrius was evaluated using low to high magnification scanning electron miscroscopy. Species-specific patterns and morphotypes (spiniform, papilliform, and filiform) of microtriches were found on scolices and strobilar tegument of Tetrabothrius (Oriana) affinis, Tetrabothrius (Oriana) filiformis, and Tetrabothrius (Tetrabothrius) sp. The presence, distribution, and form of microtriches may not be correlated with the subgeneric divisions of Tetrabothrius or the host taxon. Unique patterns do not appear to be shared with other groups of Cestodes, particularly other tetraphyllideans. We suggest that the spiniform, filiform, and papilliform types of microtriches …

Libyostrongylus Dentatus N. Sp. (Nematoda: Trichostrongylidae) From Ostriches In North America, With Comments On The Genera Libyostrongylus And Paralibyostrongylus, Eric P. Hoberg, S. Lloyd, H. Omar

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Libyostrongylus dentatus sp. n. is described from ostriches on farms from North Carolina and Texas. Nematodes were recovered from the posterior proventriculus and under the koilon lining of the gizzard; the parasites occurred in mixed infections with Libyostrongylus douglassii. The species is distinguished from congeners by the presence of a prominent, dorsal, esophageal tooth; in males by the structure of the dorsal ray and spicules; and in females by small eggs (52-62 gm in length), a sublateral vulva situated at 93% of the body length from the anterior, and a strongly curled, digitate, tail with cuticular inflations at the …

Historical Biogeography And Modes Of Speciation Across High-Latitude Seas Of The Holarctic: Concepts For Host-Parasite Coevolution Among The Phocini (Phocidae) And Tetrabothriidae (Eucestoda), Eric P. Hoberg

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Species of Anophryocephalus are host-specific parasites of pinnipeds in the Holarctic. Phylogenetic analysis of 7 species postulates A. anophrys as the basal taxon and A. inuitorum as basal to A. skrjabini; A. arcticensis is basal to A. nunivakensis and A. eumetopii + A. ochotensis (single tree; consistency index = 74.4%; homoplasy slope ratio = 36.45%). Evaluation of host and geographic distributions postulates ringed seals of the Atlantic-Arctic as ancestral hosts, and the Arctic basin as a paraphyletic area with respect to the North Pacific. Cospeciation within this assemblage was dependent on intense isolation of small effective populations of definitive hosts …

Anophryocephalus Inuitorum Sp. Nov. And A. Arcticensis Sp. Nov. (Eucestoda: Tetrabothriidae) In Ringed Seals (Phoca Hispida Hispida) And Harp Seals (Phoca Groenlandica) From High-Latitude Seas Of Eastern Canada And The Arctic Basin, Eric P. Hoberg, Lena N. Measures

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Anophryocephalus inuitorum sp. nov. and A. arcticensis sp. nov. are described from ringed seals (Phoca hispida hispida) in the eastern Canadian Arctic; the latter species is also reported from harp seals (Phoca groenlandica) in the Gulf of St. Lawrence. Anophryocephalus inuitorum is most similar to A. skrjabini, but can be distinguished by fewer testes (14-27) and smaller dimensions of the strobila, neck (3.0-5.9 mm long), and cirrus sac (31-70 μm long), diameter of the genital atrium (44 -68 pm), and length of the male canal (23-42 μm long). Anophyrocephulus arcticensis resembles A. nunivakensis in the …

1H, 15N, 13C And 13Co Assignments And Secondary Structure Determination Of Basic Fibroblast Growth Factor Using 3d Heteronuclear Nmr Spectroscopy, Franklin J. Moy, Andrew P. Seddon, Ernest B. Campbell, Peter Böhlen, Robert Powers

Robert Powers Publications

The assignments of the ¹H, ¹⁵N, ¹³CO, and ¹³C resonances of recombinant human basic fibroblast growth factor (FGF-2), a protein comprising 154 residues and with a molecular mass of 17.2 kDa, is presented based on a series of three-dimensional triple-resonance heteronuclear NMR experiments. These studies employ uniformly labeled ¹⁵N- and ¹⁵N-/¹³C-labeled FGF-2 with an isotope incorporation >95% for the protein expressed in E. coli. The sequence-specific backbone assignments were based primarily on the interresidue correlation of C^α, C^β, and H^α to the backbone amide ¹H …

19. Pedogenic Alteration Of Basalts Recovered During Leg 144, Mary Anne Holmes

Department of Earth and Atmospheric Sciences: Faculty Publications

Basalts erupted to form the atolls and guyots of the Western Pacific have been altered in various ways, ranging from hydrothermal alteration to subaerial weathering by meteoric waters in a tropical environment. Subaerial weathering has been moderate to extreme. Moderate subaerial weathering is expressed by dissolution or replacement of primary minerals (olivine, pyroxenes, plagioclase feldspar) and alteration of glassy or aphanitic matrix to clay minerals, goethite, and hematite. The clay minerals are kaolinite or a brown smectite. Kaolinite concentrations decrease downhole and smectite concentrations increase. Although primary minerals are generally not preserved, primary structures, such as vesicles (generally filled by …

Effects Of Track Structure And Cell Inactivation On The Calculation Of Heavy Ion Mutation Rates In Mammalian Cells, Francis A. Cucinotta, J. W. Wilson, M. R. Shavers, Robert Katz

Robert Katz Publications

It has long been suggested that inactivation severely effects the probability of mutation by heavy ions in mammalian cells. Heavy ions have observed cross sections of inactivation that approach and sometimes exceed the geometric size of the cell nucleus in mammalian cells. In the track structure model of Katz the inactivation cross section is found by summing an inactivation probability over all impact parameters from the ion to the sensitive sites within the cell nucleus. The inactivation probability is evaluated using the dose-response of the system to γ-rays and the radial dose of the ions and may be equal to …

Effects Of Track Structure And Cell Inactivation On The Calculation Of Heavy Ion Mutation Rates In Mammalian Cells, Francis Cucinotta, J. W. Wilson, M.R. Shavers, Robert Katz

Robert Katz Publications

It has long been suggested that inactivation severely effects the probability of mutation by heavy ions in mammalian cells. Heavy ions have observed cross sections of inactivation that approach and sometimes exceed the geometric size of the cell nucleus in mammalian cells. In the track structure model of Katz the inactivation cross section is found by summing an inactivation probability over all impact parameters from the ion to the sensitive sites within the cell nucleus. The inactivation probability is evaluated using the dose-response of the system to γ-rays and the radial dose of the ions and may be equal to …

Cluster Analysis Of The Coprolites From Antelope House: Implications For Anasazi Diet And Cuisine, Mark Q. Sutton, Karl Reinhard

Karl Reinhard Publications

This paper reports on a cluster analysis of 155 coprolites from Antelope House, a prehistoric Anasazi site in Canyon de Chelly, Arizona. The analysis revealed three primary clusters; whole kernel maize, milled maize, and nonmaize, which we believe to represent seasonal- and preference-related cuisine. Protein residue analysis on a subsample of the specimens added depth to the analysis.

Failure To Observe Electron Circular Dichroism In Camphor, K. W. Trantham, M. E. Johnston, Timothy J. Gay

Timothy J. Gay Publications

We have searched for evidence of electron circular dichroism, the preferential
transmission of longirudinally polarized electrons lhrough a chiral medium, using stereoisomers of camphor. Such an effect was seen by Campbell and Farago in 1987 for 5 eV elecvons. Within our detection limit (~0.02%) we have not observed asymmehic transmission at either an incident electron energy of 1 eV or 5 eV. ln preparation for this inquiry, we also measured the total scattering cross section for camphor in the energy range 0.5-5 eV.

Global Regulation Of A Σ54-Dependent Flagellar Gene Family In Caulobacter Crescentus By The Transcriptional Activator Flbd, Jianguo Wu, Andrew K. Benson, Austin Newton

Department of Food Science and Technology: Faculty Publications

Biosynthesis of the Caulobacter crescentus polar flagellum requires the expression of a large number of flagellar (fla) genes that are organized in a regulatory hierarchy of four classes (I to IV). The timing of fla gene expression in the cell cycle is determined by specialized forms of RNA polymerase and the appearance and/or activation of regulatory proteins. Here we report an investigation of the role of the C. crescentus transcriptional regulatory protein FlbD in the activation of σ⁵⁴-dependent class III and class IV fla genes of the hierarchy by reconstituting transcription from these promoters in vitro. …

Feeding Responses To Predator-Based Repellents In The Mountain Beaver (Aplodontia Rufa), Gisela Epple, J. Russell Mason, Evgueny Aronov, Dale L. Nolte, Richard Hartz, Ron Kaloostian, Dan Campbell, Amos Smith Iii

United States Department of Agriculture Wildlife Services: Staff Publications

Predator odors have potential as feeding repellents for mammalian herbivores, including Aplodontia rufa, the mountain beaver. However, the repellency of major chemical constituents of natural predator scents for this species has not been evaluated. In this study, the effects of several synthetic sulfur compounds from predator scents on feeding by mountain beavers were assessed and compared to the effects of coyote (Canis latrans) urine. Retrieval of food by mountain beavers from bowls scented with either coyote urine, diluted with water to different concentrations, synthetic components of predator scents, or control odorants was studied. The following synthetic compounds …

Survey Of Omega-3 Fatty Acids In Diets Of Midwest Low-Income Pregnant Women, Nancy M. Lewis, Anne C. Widga, Janet S. Buck, Andrea M. Frederick

Department of Nutrition and Health Sciences: Faculty Publications

The objectives of this project were to detennine the omega-3 fatty acid (ω-3 FA) consumption of low-income pregnant women, and to identify food sources of ω-3 FA in their diets. Thirty women provided three days of dietary intake that were analyzed using the Food Processor Plus computer program. Mean daily consumption of ω-3 FA was 1.060 ± 0.030 g/day. The major form of the ω-3 FA was α-linolenic acid (α-LNA; 93%), with less from eicosapentanoic acid (EPA; 2%), and docosahexanoic acid (DHA; 5%). Foods that provided the most α-LNA were fats, oils, salad dressings, and milk products. EPA …

A New Pinworm, Didelphoxyuris Thylamisis N. Gen., N. Sp. (Nematoda: Oxyurida) From Thylamys Elegans (Waterhouse, 1839) (Marsupialia: Didelphidae) In Bolivia, Scott Lyell Gardner, Jean-Pierre Hugot

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Didelphoxyuris thylamisis n. gen., n. sp. is described from the caecum of Thylamys elegans (Waterhouse, 1839) (Marsupialia: Didelphidae) collected in the eastern region of the Andes of Bolivia. Didelphoxyuris thylamisis n. sp. differs from the only pinworm described from marsupials in the Neotropics (Neohilgertia venusti Navone, Suriano et Pujol, 1990) in having only three oesophageal teeth, non-operculated eggs, females that are didelphic, and males that possess no preanal papillae. Several other species of pinworms have been described from marsupials in Australia, but all are characterized by possessing a buccal capsule that is strongly cuticularized with inter-radial lamellae. These structures …

Caryospora Simplex (Apicomplexa: Eimeriidae) From A Captive Kaznakov's Viper (Vipera Kaznakovi), Patricia G. Wilber, John A. Hnida, Michael J. Richard, Donald W. Duszynski

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Caryospora simplex is reported for the first time from the feces of a captive female Kaznakov’s viper (Vipera kaznakovi) in Albuquerque, New Mexico (USA). Coccidian meronts and gamonts were observed in the intestinal epithelial cells of another female Kaznakov’s viper that died in October 1993.

Caridean Shrimps Associated With The Slimy Sea Plume (Pseudopterogorigia Americana) In Midsummer At Guana Island, British Virgin Islands, West Indies, Stephen Spotte, Patricia M. Bubucis, Robin M. Overstreet

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Fifty-one slimy sea plumes (Pseudopterogorgia americana Gmelin, 1791) were sampled for caridean shrimps at Guana Island, British Virgin Islands, during one week in July 1992. Sam- pling depth ranged from 3-22 m. Nine species were collected: Hippolyte nicholsoni Chace, 1972; Latreutes sp.; Neopontonides chacei Heard, 1986; Perclimenes cf. patae Heard and Spotte, 1991; Periclimenes cf. pauper Holthuis, 1951; Periclimenes sp.; Pseudocoutierea antillensis Chace, 1972; Tozeuma cf. cornutum Milne Edwards, 1881; and Trachycaris rugosa (Bate, 1888). A total of 1,418 specimens (including fragments) was obtained. The number of shrimp species per gorgonian ranged from 1-5; one gorgonian harbored 156 shrimps. …

Umingmakstrongylus Pallikuukensis Gen. Nov. Et Sp. Nov. (Nematoda: Protostrongylidae) From Muskoxen, Ovibos Moschafus, In The Central Canadian Arctic, With Comments On Biology And Biogeography, Eric P. Hoberg, Lydden Polley, A. Gunn, J. S. Nishi

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

Umingmakstrongylus pallikuukensis gen. nov. et sp. nov. is established for a protostrongylid nematode in muskoxen, Ovibos moschatus, from the Kitikmeot Region (central Arctic) of the Northwest Territories, Canada. It is distinguished from Cystocaulus and other Muelleriinae by characters that include the following: males: deeply incised, bilobed bursa, independent externodorsal rays, telamon composed of distal transverse plate, absence of falcate crurae, and spicules not distally split; females: absence of provagina; and first-stage larvae: presence of three cuticular folds on the tail. The great length of females (468 mm) and males (171 mm) is exceptional among the Protostrongylidae. Pathognomonic lesions include …

Endocrinology Of The Avian Reproductive System, Mary Ann Ottinger, Murray R. Bakst

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

The purpose of this review is to provide an overview of the avian reproductive system. Attention is given to the neuroendocrine regulation of hypothalamic and pituitary gland hormones as well as the target tissues regulated by these hormones. Emphasis is placed on the dynamics of the system and the effects of alterations resulting from environmental and other influences on the function of the reproductive system. The ovulatory cycle, oviduct, and shell gland are discussed relative to egg formation and the hormonal regulation of this process. Testicular function and the cellular bases for spermatogenesis and steroid production are also discussed.

Life History Of Innnature Lyctocoris Campestris (Hemiptera: Anthocoridae): Effects Of Constant Temperatures And Relative Humidities, Megha N. Parajulee, Thomas W. Phillips, James E. Throne, Erik V. Nordheim

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

Life history of immature Lyctocoris campestris (F.), a predator of stored-product insects, was investigated at 17, 21, 25, and 29°C and =43, =58, and =75% RH in the laboratory. Most life history traits of L. campestris were influenced by temperature, but none of the traits was influenced by relative humidity. The egg incubation period was =7 d at 25- 29°C, but increased sharply at temperatures <25°C. An equation was developed to predict egg incubation period over a range of temperatures. Egg hatch rate did not vary with temperatures nor with the relative humidities. The mean hatch rate ranged from 78 to 86% across different temperatures summed across 3 relative humidities. The instar-specific nymphal development also varied with temperature. The 2nd stadium was the shortest followed by the 3rd, 1st, and the 4th, and the 5th stadium was the longest across all 4 temperatures. However, the ratios of duration of nymphal stadia remained constant across all 4 temperatures tested. Total nymphal durations were 20.5, 27.6, 40.1, and 66.2 d at 29,25,21, and 1~C, respectively; all 4 were significantly different from one another. The relationships between temperature and instar-specific nymphal durations and total nymphal durations were described by the same equation for both females and males; total nymphal durations did not vary with sex. Nymphal survival rates ranged from 0.60 to 1.00 and did not vary significantly with temperature or relative humidity. Sex ratio (proportion of males) of emerging adults ranged from 0.40 to 0.70, but did not differ from 1:1. These life history data are reported in a manner useful for developing a computer model for simulating L. campestris population dynamics.