Life Sciences Commons^™

Spiranthes Gracilis (Bigelow) Beck, Gordon C. Tucker

Specimens by Name

No abstract provided.

Correlation Between Histone Lysine Methylation And Developmental Changes At The Chicken Β-Globin Locus, Michael D. Litt, Melanie A. Simpson, Miklos Gaszner, D. David Allis, Gary Felsenfeld

Department of Biochemistry: Faculty Publications

Methylation of histones at specific residues plays an important role in transcriptional regulation. Chromatin immunoprecipitation of dimethylated lysine 9 on histone H3 across 53 kilobases of the chicken β-globin locus during erythropoiesis shows an almost complete anticorrelation between regions of elevated lysine 9 methylation and acetylation. Lysine 9 is methylated most over constitutive condensed chromatin and developmentally inactive globin genes. In contrast, lysine 4 methylation of histone H3 correlates with H3 acetylation. These results lead us to propose a mechanism by which the insulator in the β-globin locus can protect the globin genes from being silenced by adjacent condensed chromatin.

In Vitro Enzymatic Chlorophyll Catabolism In Wheat Elicited By Cereal Aphid Feeding, Xinzhi Ni, Sharron S. Quisenberry, John P. Markwell, Tiffany Heng-Moss, Leon G. Higley, Frederick P. Baxendale, Gautam Sarath, Robert Klucas

Department of Entomology: Faculty Publications

Chlorophyll degradation is a complex phenomenon that often accompanies insect feeding damage to plants. Loss of chlorophyll can be initiated by several reactions, including oxidative bleaching, chlorophyllase activity, and Mg-dechelatase activity. Extracts from the Russian wheat aphid [Diuraphis noxia (Mordvilko)], the bird cherry-oat aphid [Rhopalosiphum padi (L.)], and aphid-infested and uninfested wheat plants were assayed in vitro for activities involved in chlorophyll degradation. Although the initial infestation was the same (10 apterous adults) for both aphid species, D. noxia weight was significantly higher than R. padi after feeding for 12 days. Consequently, D. noxia feeding caused greater fresh …

Master Conservationist Presentations - 2001, John Owens

John Owens: Speeches and Appearances

We begin the 2001 Master Conservationist program with honorees in production agriculture from District A which includes the Panhandle of Nebraska. I would like to ask Leon and Cheryl Burkhart-Kriesel (Kresel) of Gurley who are unable to be present. They operated the family farm in partnership with Fred and Viola Kriesel until 1984 when Leon and Cheryl become sole owners/operators. The Kriesels produce certified wheat, millet, oats, and barley seed on 3200 dryland acres that are owned, rented, or contracted. Since 1984, 45,000 feet of terraces have been installed. Their holistic conservation plan also includes over 57,000 feet of windbreaks …

Fraxinus Pennsylvanica Marsh., John E. E. Ebinger

Specimens by Name

No abstract provided.

Whence Meiosis?, Anne M. Villeneuve, Kenneth J. Hillers

Biological Sciences

Sexual reproduction predominates among eukaryotic organisms on our planet. While debate continues over why this should be so, burgeoning genomic and functional information now allows us to begin to think reasonably about some of the events that may have occurred to make sex possible in the first place.

Mitogen-Activated Protein Kinase Phosphorylates And Targets Inducible Camp Early Repressor To Ubiquitin-Mediated Destruction, Ghassan Yehia, Florence Schlotter, Reza Razavi, Alessandro Alessandrini, Carlos Molina

Department of Biology Faculty Scholarship and Creative Works

Inducible cAMP early repressor (ICER) is an important mediator of cAMP antiproliferative activity that acts as a putative tumor suppressor gene product. In this study, we examined the regulation of ICER protein by phosphorylation and ubiquitination in human choriocarcinoma JEG-3 and mouse pituitary AtT20 cells. We found that cAMP stabilized ICER protein by inhibiting the mitogen-activated protein kinase (MAPK) cascade. Activation of the MAPK pathway increased ICER phosphorylation. ICER phosphorylation was abrogated by inhibition of the MAPK pathway either by cAMP or directly by the MAPK inhibitor PD098059. The MAPKs extracellular signal-regulated kinases 1 and 2 physically interact with ICER …

Thermoregulatory Profile Of A Newer Genetic Line Of Pigs, T. M. Brown-Brandl, R. A. Eigenberg, John A. Nienaber, Stephen D. Kachman

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

Researchers and producers alike have noted the increased susceptibility to heat stress exhibited by the newer genetic lines of pigs. A study was conducted to gather baseline information on the effects of acute heat stress on total heat production (THP), respiratory quotient (RQ), respiration rate (RR), and rectal temperature (T_rectal ) and to investigate the dynamic interaction of these parameters in growing–finishing barrows. Sixteen moderate–lean growth barrows were randomly assigned to a set of treatments as dictated by a repeated 4x4 Latin square crossover design. Pigs were moved from an individual pen to an indirect calorimeter where one …

Effects Of Size And Temperature On Metabolic Rate, James Gillooly, James Brown, Geoffrey West, Van Savage, Eric Charnov

Biology Faculty & Staff Publications

We derive a general model, based on principles of biochemical kinetics and allometry, that characterizes the effects of temperature and body mass on metabolic rate. The model fits metabolic rates of microbes, ectotherms, endotherms (including those in hibernation), and plants in temperatures ranging from 0 to 40C. Mass - and temperature - compensated resting metabolic rates of all organisms are similar: The lowest (for unicellular organisms and plants) is separated from the highest (for endothermic vertebrates) by a factor of about 20. Temperature and body size are primary determinants of biological time and ecological roles.

Mhc Class I Molecules And Progression To Aids, Mary Carrington, Xiaojiang Gao, Stephen J. O'Brien

Biology Faculty Articles

No abstract provided.

Vitis Aestivalis F.Michx., Bob Edgin

Specimens by Name

No abstract provided.

Humulus Lupulus L., Bob Edgin

Specimens by Name

No abstract provided.

Distinct Mechanisms Regulate Slow-Muscle Development, Michael J.F. Barresi, Joel A. D'Angelo, L. Patricia Hernández, Stephen H. Devoto

Biological Sciences: Faculty Publications

Vertebrate muscle development begins with the patterning of the paraxial mesoderm by inductive signals from midline tissues [1, 2]. Subsequent myotome growth occurs by the addition of new muscle fibers. We show that in zebrafish new slow-muscle fibers are first added at the end of the segmentation period in growth zones near the dorsal and ventral extremes of the myotome, and this muscle growth continues into larval life. In marine teleosts, this mechanism of growth has been termed stratified hyperplasia [3]. We have tested whether these added fibers require an embryonic architecture of muscle fibers to support their development and …

Nebraska Lead Xxi Fellow/Spouses Dinner, John Owens

John Owens: Speeches and Appearances

“Nearly all men can stand adversity, but if you want to test a man’s character give him power.”

That quote, by my hero Abraham Lincoln, is one I think all leaders should remember and reflect on regularly in their life, and so I pass it on to each of you. I wish each member of this LEAD group the character to use power wisely, with compassion and integrity, and a strong-sense of justice and fair play.

Meeting Minutes, September 15th, 2001, National Smokejumper Association Executive Committee

National Smokejumper Association Meeting Minutes

Agenda: Old Business; Treasurers Report.; Membership Report.; Merchandise Report.; Magazine Report.; Yearbook Report.; Trails Program.; Evergreen Museum.; Nsa Records Scanning Project.; Us Forest Service Museum.; Glacier Beer.; Additional Nsa Videos.; Status Of 2000 Data Base At The Sj Bases.; Reunion 2004.; New Business; Officers For Next Year.; Next Meeting Date.; Museum Of Mountain Flying.; Meeting Adjourned.;

Viola Striata Aiton, Gordon C. Tucker, Sarah E. Tucker

Specimens by Name

No abstract provided.

Ocean Circulation Influences On Sea Surface Temperature In The Equatorial Central Pacific, Chunzai Wang, Robert H. Weisberg

Marine Science Faculty Publications

Velocity data from an array of acoustic Doppler current profilers moored about 0°, 140°W from May 1990 through June 1991 during the Tropical Instability Wave Experiment are used in conjunction with Tropical Atmosphere‐Ocean array data and a blended sea surface temperature (SST) product to study the processes that control SST variations. The horizontal velocity data allow us to calculate the vertical velocity component by vertically integrating the continuity equation. Given the three‐dimensional temperature flux divergence, we examine the role of the ocean circulation in SST. Upwelling and downwelling are found to be associated with cooling and warming, respectively, suggesting that …

Effects Of River Inputs Into The Bay Of Bengal, Stephan D. Howden, Raghu Murtugudde

Faculty Publications

The effect of river runoff in the Bay of Bengal is examined using a reduced gravity primitive equation ocean model coupled to an atmospheric boundary layer model. Model simulations are carried out by including river discharges as surface freshwater forcing at the mouths of the rivers. To assess the effect of river inputs on the dynamics and thermodynamics of the tropical Indian Ocean, parallel simulations are carried out by neglecting the river inputs. Additionally, another set of parallel runs without penetrative radiation loss through the mixed layer is carried out. The freshwater flux due to rivers results in lower salinities …

Modelling The Trappability Of Tsetse, Glossina Fuscipes Fuscipes, In Relation To Distance From Their Natural Habitats, Adedapo Odulaja, Mohamed M. Mohamed-Ahmed

All Peer-Reviewed Publications

The log-logistic probability distribution function was employed to model trappability of Glossina fuscipes fuscipes, with respect to distance from the edge of two types of habitat. The parameters of the model were obtained using the nonlinear maximum likelihood approach. Asymptotic standard errors of the maximum likelihood estimates were computed for the parameters, and the X2 goodness-of-fit test used to assess the predicted trap catches. Simulation technique was used to estimate the radius of attraction of the unbaited biconical trap for the fly, taking the efficiency of the trap into consideration. The log-logistic model fitted well to a series of observed …

Biology Department Publications: 2001, Sam Lindgren

Biology Department Bibliographies

This document is a noncomprehensive list of publications made by graduate students, post-doctoral researchers, and faculty members in the Biology Department in 2001. It indexes those publications available through major databases, and serves as an archival record of the Department’s robust scholarly contributions.

Vitis Aestivalis F.Michx., Gordon C. Tucker, Daniel M. Tucker

Specimens by Name

No abstract provided.

Almonds Western Australia, Andrew Quinn, David Pocock

Horticulture published reports

The Almond industry 1s one of the less explored new industry options in Western Australia, despite offering one of the more significant opportunities for expansion and market development. Previous attempts to expand the industry have met with little progress primarily because of the small orchard areas planted, limited economies of scale, significant impact by birds and absence of a local processing plant.

Global Almond exports exceed US$1 billion per annum and are dominated by California. Almond products are traded in the international commodity market with prices primarily set by the USA.

Critical to the development of the industry in Western …

Nebraska Bankers Association, John Owens

John Owens: Speeches and Appearances

Thank you for inviting me to be with you today. It is a real pleasure, and I look forward to visiting with you both individually and collectively, now and in the future. I'd looked forward to meeting with you all earlier in the year, but a death in our family took my wife Virginia and me to Texas at the time of your April meeting, so I am very glad to have this opportunity to be with you now.

Cryopreservation Of Embryos Of The New World Screwworm Cochliomyia Hominivorax (Diptera: Calliphoridae), R.A. Leopold, W.B. Wang, Dennis Berkebile, T.P. Freeman

Department of Entomology: Faculty Publications

A method for cryopreserving embryos of the screwworm, Cochliomyia hominivorax (Coquerel), was developed for the long-term storage of strains used in research projects and for colonies maintained as back-up to production strains that are mass-reared for sterile insect release programs. This protocol, when combined with a previous procedure that was designed to render screwworm embryos permeable to water loss and the influx of cryoprotectants, yields rates of ~53% hatching, 22% pupation, and 75% adult emergence. These yields are all lower than control levels, but by the next generation the progeny of the cryopreserved flies are near or equal to control …

Tyrannasorus Rex Ratcliffe And Ocampo, A New Genus And Species Of Miocene Hybosorid In Amber From The Dominican Republic (Coleoptera: Scarabaeoidea: Hybosoridae), Brett C. Ratcliffe, Federico Carlos Ocampo

University of Nebraska State Museum: Entomology Papers

Tyrannasorus rex Ratcliffe and Ocampo (Coleoptera: Scarabaeoidea: Hybosoridae), a new genus and new species of fossil hybosorid, is described from the Dominican Republic. This fossil scarabaeoid is embedded in the amber resin of Hymenaea protera Poinar (Leguminosae), and it dates from the Miocene.

Se describe Tyrannasorus rex Ratcliffe and Ocampo (Coleoptera: Scarabaeoidea: Hybosoridae), un nuevo género y especie de hybosórido fosil de República Dominicana. Este scarabeoideo fósil está incluído en ámbar originado de la resina de Hymenaea protera Poinar (Leguminosae) y data del Mioceno.

A Review Of The Neotropical Genus Neocorvicoana Ratcliffe And Micó, New Genus (Coleoptera: Scarabaeidae: Cetoniinae: Gymnetini), Brett C. Ratcliffe, Estefanía Micó

University of Nebraska State Museum: Entomology Papers

The southern Neotropical cetoniine genus Neocorvicoana Ratcliffe and Micó new genus (Coleoptera: Scarabaeidae: Cetoniinae: Gymnetini) is established for three species previously placed in Corvicoana Strand, 1934 (nomen nudum) and Gymnetis MacLeay, 1819: N. chalybea (Kirby), N. reticulata (Schürhoff), and N. tricolor (Schürhoff), new combinations. The type species of the new genus is N. reticulata (Kirby). Corvicoana rudolfi (Frölich) is transferred to the genus Gymnetis. Corvicoana suavis (Schürhoff) and C. castanea (Schürhoff) are junior synonyms of N. chalybea. We include a taxonomic key to the species, nomenclatural history, descriptions, illustrations, and commentary.

Se establece el género Neocorvicoana Ratcliffe …

Stem Morphology And Anatomy In Amaranthus L. (Amaranthaceae)—Taxonomic Significance, Mihai Costea, Darleen A. Demason

Biology Faculty Publications

The range of variation within the genus Amaranthus L. (Amaranthaceae) is described for a number of stem characters including: morphology, epidermis, primary stem vasculature and mechanism of secondary growth. The results provide new characters (phyllotaxy, complexity of leaf vascular supply and relative amount of secondary growth) that support (1) a new infrageneric classification (subgenus Amaranthus vs subgenus Albersia (Kunth)Gren. & Dodr.), and (2) the separation within the “hybridus” complex of cultivated amaranths (A. caudatus L., A. cruentus L., and A. hypochondriacus L.) from their presumed wild ancestors (A. hybridus L. subsp. quitensis (Kunth) Costea & Carretero, …

Table Of Contents Volume 12, Number 3/4, Fall 2001, Risk Editorial Board

RISK: Health, Safety & Environment (1990-2002)

Table of contents for the journal RISK: Health, Safety & Environment (ISSN: 1073-8673)

Redressing The Silent Interim: Precautionary Action & Short Term Tests In Toxicological Risk Assessment, Timothy Riley

RISK: Health, Safety & Environment (1990-2002)

The author recommends that a stronger emphasis be placed on creating and implementing short-term tests that use iterative, conservative-based, tiered procedures in conjunction with a precautionary attitude during the interim phase of toxicological risk assessments.

Workplace Pollution: Nuclear Safety, Ethics, And The Exploitation--Avoidance Argument, Kristin Shrader-Frechette

RISK: Health, Safety & Environment (1990-2002)

The author reviews evidence of poor worker health and safety practices in United States Department of Energy nuclear facilities in contending that less protective standards for workplace hazards constitute an environmental injustice not rectified by a hazard pay premium.