Digital Commons Network^™

A Genetic Evaluation Of Growth In Sheep Using Random Regression Techniques, R. M. Lewis, S. Brotherstone

Department of Animal Science: Faculty Publications

Repeated measures of live weight in growing animals are used to describe the path by which they travel from birth to maturity. A family of growth functions-the Gompertz is one in particular-has been used successfully to describe this journey with relatively few parameters (most importantly mature size and a rate parameter). However, using these functions to differentiate the genetic merit of individual animals to grow is problematic since the estimates of these parameters are highly correlated and are obtained with varying precision among animals. An alternative is random regression (RR) methodology. It allows environmental effects specific to the time of …

Comparative Epidemiology Of Scrapie Outbreaks In Individual Sheep Focks, C. A. Redman, P. G. Coen, R. M. Lewis, W. S. Dingwall, J. D. Foster, M. E. Chase-Topping, N. Hunter, M. Woolhouse, L. Matthews

Department of Animal Science: Faculty Publications

Data recording the course of scrapie outbreaks in 4 sheep flocks (2 in Cheviot sheep and 2 in Suffolks) are compared. For each outbreak the data on scrapie incidence and sheep demography and pedigrees cover periods of years or decades. A key finding is that the incidence of clinical cases peaks in sheep 2-3 years old, despite very different forces-of infection.This is consistent with age-specific susceptibility of sheep to scrapie, as has beenreported for cattle to bovine spongiform encephalopathy and for humans to variant Creutzfeldt-Jakob disease. Scrapie incidence was higher in ewes than rams and at certain times of years, …

Changes In Muscularity With Growth And Its Relationship With Other Carcass Traits In Three Terminal Sire Breeds Of Sheep, H. E. Jones, R. M. Lewis, M. J. Young, C. C. Warkup

Department of Animal Science: Faculty Publications

Data were available for 160 sheep (50 Suffolk males, 50 Suffolk females, 40 Texel males and 20 Charollais males). One fifth of animals within each breed and sex were slaughtered at each of 14, 18 or 22 weeks of age and two-fifths slaughtered at 26 weeks. After slaughter linear measurements were taken on the carcass. The left side of each carcass was then separated into eight joints and each joint dissected into lean, bone and fat. Five muscularity measures (three for the longissimus thoracis et lumborum (LTL) muscle, one for the hind leg and one for the whole carcass) and …

Responses To Selection For Lean Growth In Sheep, G. Simm, R. M. Lewis, B. Grundy, W. S. Dingwall

Department of Animal Science: Faculty Publications

This paper reports the selection responses achieved, and related results, following 9 years of index selection for lean growth in Suffolk sheep. The breeding goal of the index used comprised carcass lean weight and carcass fat weight at a constant age, with relative economic values of + 3 and –1 per kg. The selection criteria were live weight (LWT), ultrasonic fat depth (UFD) and ultrasonic muscle depth (UMD) adjusted to a constant age of 150 days. By year 9, responses in LWT, UFD and UMD in both sexes, as judged by the divergence between selection and control line performance, amounted …

Nebraska Blueprint – Winter 2002

Nebraska Blueprint (Student Publication)

Table of Contents:

From the Editor

From the Office of College Relations – Restructuring of Dean's Office expands services to students—on all three campuses—and alumni.

College Sees Many Exciting Changes – A letter from Dr. John Ballard, Associate Dean

Coming to America: French Student Experiences NU Culture – Karine Hubert grew up in a small French town with little knowledge about America. Her studies at NU changed all that.

Venturing Out: Students Study Abroad in Germany – Engineering students Mark Dietz and John Prauner learn about more than engineering while studying in Germany.

Ambassadors, Diplomats Take on Leadership Roles

Diversity …

Uncertainties In Sediment Quality Weight-Of-Evidence (Woe) Assessments, Graeme E. Batley, G. Allen Burton, Peter M. Chapman, Valery E. Forbes

Valery Forbes Publications

Uncertainties in sediment quality assessments are discussed in five categories: (1) sediment sampling, transport and storage; (2) sediment chemistry; (3) ecotoxicology; (4) benthic community structure; and (5) data uncertainties and QA/QC. Three major exposure routes are considered: whole sediments, and waters in sediment pores and at the sediment-water interface. If these uncertainties are not recognized and addressed in the assessment process, then erroneous conclusions may result. Recommendations are provided for addressing the identified uncertainties in each of the key areas. The purpose of this paper is to improve the reporting of sediment quality assessments.

Purification And Characterization Of Hemolymph Juvenile Hormone Esterase From The Cricket, Gryllus Assimilis, Anthony J. Zera, Travis Sanger, Jeremiah Hanes, Lawrence G. Harshman

Anthony Zera Publications

Juvenile hormone esterase (JHE) from the serum of the cricket, Gryllus assimilis, was purified to homogeneity in a four-step procedure involving polyethylene glycol precipitation, hydrophobic interaction FPLC, and ion exchange FPLC. This procedure could be completed in 4 days and resulted in a greater than 900-fold purification with greater than 30% recovery. The purified enzyme exhibited a single band on a silver-stained SDS PAGE gel and had an apparent subunit molecular mass of 52 kDa. The native subunit molecular mass, determined by gel permeation FPLC, was 98 kDa, indicating that JHE from Gryllus assimilis is a dimer of two …

Methods And Compositions To Enhance Tenderness And Value Of Meat, Chris R. Calkins, Jesus Pablo Velazco De La Garcia, Nancy Coromoto Jerez-Timaure

Department of Animal Science: Faculty Publications

A method of enhancing the tenderness of meat for animal or human consumption by treatment of pre-rigor muscle with the compositions of the invention. It has been found that other quality meat traits can also be enhanced with the method of the invention.

Arabidopsis Disrupted In Sqd2 Encoding Sulfolipid Synthase Is Impaired In Phosphate-Limited Growth, Bin Yu, Changcheng Xu, Christoph Benning

Bin Yu Publications

The sulfolipid sulfoquinovosyldiacylglycerol is one of the three nonphosphorous glycolipids that provide the bulk of the structural lipids in photosynthetic membranes of seed plants. Unlike the galactolipids, sulfolipid is anionic at physiological pH because of its 6-deoxy-6-sulfonate-glucose (sulfoquinovose) head group. The biosynthesis of this lipid proceeds in two steps: first, the assembly of UDP-sulfoquinovose from UDP-glucose and sulfite, and second, the transfer of the sulfoquinovose moiety from UDP-sulfoquinovose to diacylglycerol. The first reaction is catalyzed by the SQD1 protein in Arabidopsis. Here we describe the identification of the SQD2 gene of Arabidopsis.We propose that this gene encodes the …

Cognition As An Independent Variable: Virtual Ecology, Alan C. Kamil, Alan B. Bond

Papers in Behavior in Biological Sciences

On close examination, human cultural artifacts bear the unmistakable impress of the structure of the human mind: our tools, habitations. and methods of communication have been molded to suit the strengths and limitations of the human cognitive system (Nosman 1988). It has not commonly been emphasized. however. that similar shaping processes have taken place over the course of biological evolution in response to the cognitive features of other, nonhuman species (Bonner 1980; von Frisch 1974).
Cognitive influences are particularly evident in the modifications of color patterns and behavior of prey species that take advantage of biases and constraints in the …

Purification And Characterization Of Acylation Stimulating Protein From Porcine Serum, Hong Zhang, Sheila K. Jacobi, Candace F. Toombs, Katherine H. Cianflone, Natalya Nersesian, Gautam Sarath, Jess L. Miner

Gautam Sarath Publications

A method for purifying acylation stimulating protein (ASP) from porcine serum is described. The mRNA encoding ASP was cloned by reverse transcriptase-polymerase chain reaction which predicted a 76 residue peptide. Based on this sequence, we generated antisera to a C-terminal peptide (ASP_1–20) which aided ASP purification. Identity of the purified protein was verified by N-terminal sequencing. The molecular mass of porcine ASP is 8926. Porcine ASP stimulated esterification of fatty acid into triacylglycerol in cultured human cells with potency similar to that of human ASP (twofold at 5 μM). Based on this evidence that ASP exists in porcine …

A Comparative Study Of Geometric Rule Learning By Nutcrackers (Nucifraga Columbiana), Pigeons (Columba Livia), And Jackdaws (Corvus Monedula ), Juli E. Jones, Elena Antoniadis, Sara J. Shettleworth, Alan Kamil

Papers in Behavior in Biological Sciences

Three avian species, a seed-caching corvid (Clark’s nutcrackers; Nucifraga columbiana), a non-seed-caching corvid (jackdaws; Corvus monedula), and a non-seed-caching columbid (pigeons; Columba livia), were tested for ability to learn to find a goal halfway between 2 landmarks when distance between the landmarks varied during training. All 3 species learned, but jackdaws took much longer than either pigeons or nutcrackers. The nutcrackers searched more accurately than either pigeons or jackdaws. Both nutcrackers and pigeons showed good transfer to novel landmark arrays in which interlandmark distances were novel, but inconclusive results were obtained from jackdaws. Species differences in this …

Active Formation Of Mixed-Species Grouse Leks: A Role For Predation In Lek Evolution?, Robert M. Gibson

School of Biological Sciences: Faculty Publications

Behavioural ecologists have interpreted avian leks as products of sexual selection, in which males display socially to increase their opportunities to mate. However, without invoking reproductive queuing or kin selection, this paradigm does not necessarily explain why many males that fail to mate participate in leks. An alternative solution, that males also aggregate to reduce predation, has previously lacked compelling support. We show that mixed-species leks, comprising two congeneric grouse, form when single males or small groups of one species, the greater prairie chicken Tympanuchus cupido, join leks of another, the sharp-tailed grouse T. phasianellus. We documented the …

Active Formation Of Mixed-Species Grouse Leks: A Role For Predation In Lek Evolution?, Robert M. Gibson, Andrea S. Aspbury, Leonard L. Mcdaniel

School of Biological Sciences: Faculty Publications

Behavioral ecologists have interpreted avian leks as products of sexual selection, in which males display socially to increase their opportunities to mate. However, without invoking reproductive queuing or kin selection, this paradigm does not necessarily explain why many males that fail to mate participate in leks. An alternative solution, that males also aggregate to reduce predation, has previously lacked compelling support. We show that mixed-species leks, comprising two congeneric grouse, form when single males or small groups of one species, the greater prairie chicken Tympanuchus cupido, join leks of another, the sharp-tailed grouse T. phasianellus. We documented the …

A Mortality Cost Of Virginity At Older Ages In Female Mediterranean Fruit Flies, James R. Carey, Pablo Liedo, Lawrence G. Harshman, Ying Zhang, Hans-Georg Müller, Linda Partridge, Jane-Ling Wang

Lawrence G. Harshman Publications

Mortality rates were measured over the lifetime of 65,000 female Mediterranean fruit flies, Ceratitis capitata, maintained in either all-female (virgin) cages or cages with equal initial numbers of males, to determine the effect of sexual activity and mating on the mortality trajectory of females at older ages. Although a greater fraction of females maintained in all-female (virgin) cages survived to older ages, the life expectancy of the surviving virgins was less than the life expectancy of surviving non-virgins at older ages. This was due to a mortality crossover where virgin flies experience lower mor-tality than mated flies from eclosion to …

Food Pulses Increase Longevity And Induce Cyclical Egg Production In Mediterranean Fruit Flies, James R. Carey, Pablo Liedo, Lawrence G. Harshman, X. Liu, Hans-Georg Müller, Linda Partridge, Jane-Ling Wang

Lawrence G. Harshman Publications

1. Inasmuch as virtually all studies on mortality and reproduction in insects are conducted under conditions in which food availability is constant, little is known about the demographic response of insects to variable food environments. For example, it is not known if and to what extent the life expectancy of insects subjected to shortages of high-quality food will increase and/or whether this increase is associated with major decreases in lifetime reproduction.

2. Therefore cohorts of 100 individual female medflies were subjected to different sets of conditions of protein availability (interspersed with sugar-only diets) including ad libitum sugar-only (no protein), ad …

Relating The Unique Sensory System Of Amblypygids To The Ecology And Behavior Of Phrynus Parvulus From Costa Rica (Arachnida, Amblypygi), Eileen Hebets

Eileen Hebets Publications

Abstract: While the unique sensory system and neuroanatomy of amblypygids suggest that olfaction is important in their lives, to date no behavioral data exist to support this suggestion. To gain insight into amblypygid ecology and behavior, an individual mark–recapture study was conducted on the Costa Rican amblypygid Phrynus parvulus. Within two 50 by 25 m plots, the distribution and movement patterns of individual amblypygids were recorded for over 2 months. A total of 88 adult individuals (60 males and 28 females) were marked, with an average 51% resighted. Females were resighted more frequently than males (75% females, 40% males). …

Population Growth Rate As A Basis For Ecological Risk Assessment Of Toxic Chemicals, Valery E. Forbes, Peter Calow

Valery Forbes Publications

Assessing the ecological risks of toxic chemicals is most often based on individual-level responses such as survival, reproduction or growth. Such an approach raises the following questions with regard to translating these measured effects into likely impacts on natural populations. (i) To what extent do individual-level variables underestimate or overestimate population-level responses? (ii) How do toxicant-caused changes in individual-level variables translate into changes in population dynamics for species with different life cycles? (iii) To what extent are these relationships complicated by population-density effects? These issues go to the heart of the ecological relevance of ecotoxicology and we have addressed them …

Rabd, A Dictyostelium Rab14-Related Gtpase, Regulates Phagocytosis And Homotypic Phagosome And Lysosome Fusion, Ed Harris, James Cardelli

Department of Biochemistry: Faculty Publications

RabD, a Dictyostelium Rab14-related GTPase, localizes in the endo-lysosomal pathway and contractile vacuole system of membranes. Cell lines expressing dominant-negative RabD were defective in endocytosis, endosomal membrane flow and homotypic lysosome fusion. In support of a role for RabD in fusion, cells overexpressing constitutively active RabD^Q67L accumulated enlarged hydrolase-rich acidic vesicles ringed with GFP-RabD, consistent with RabD directly regulating lysosome fusion. To determine whether RabD also regulated phagocytosis and/or homotypic phagosome fusion (a process stimulated by many intracellular pathogens), cells overexpressing dominant-active (RabD^Q67L) or dominant-negative (Rab^N121I) RabD were analyzed microscopically and biochemically. The rate of …

Selenoprotein R Is A Zinc-Containing Stereo-Specific Methionine Sulfoxide Reductase, Gregory V. Kryukov, R. Abhilash Kumar, Ahmet Koc, Zhaohul Sun, Vadim N. Gladyshev

Department of Biochemistry: Faculty Publications

Selenoprotein R (SelR) is a mammalian selenocysteine-containing protein with no known function. Here we report that cysteine homologs of SelR are present in all organisms except certain parasites and hyperthermophiles, and this pattern of occurrence closely matches that of only one protein, peptide methionine sulfoxide reductase (MsrA). Moreover, in several genomes, SelR and MsrA genes are fused or clustered, and their expression patterns suggest a role of both proteins in protection against oxidative stress. Consistent with these computational screens, growth of Saccharomyces cerevisiae SelR and MsrA mutant strains was inhibited, and the strain lacking both genes could not grow, in …

Species Richness, Latitude, And Scale-Sensitivity, S. Kathleen Lyons, Michael R. Willig

School of Biological Sciences: Faculty Publications

The latitudinal gradient of species richness is well documented for a variety of taxa in both terrestrial and aquatic environs. Moreover, a number of recent attempts to assess the effects of scale on the relationship have concluded that the latitudinal pattern is scale-invariant. Nonetheless, the power of those approaches is predicated on precise knowledge of the forms of the latitudinal gradient, the area relationship, and their interaction. We used a model developed by J. Pastor, A. Downing, and H. E. Erickson for assessing the effects of scale on the productivity–diversity gradient to avoid such complications. More specifically, for 253 sets …

Clone Size Of Andropogon Gerardii Vitman (Big Bluestem) At Konza Prairie, Kansas, Kathleen H. Keeler, Charles F. Williams, Linda S. Vescio

School of Biological Sciences: Faculty Publications

Clone size of plants of Andropogon gerardii from Konza Prairie Biological Station, Manhattan, Kansas was estimated from spatial patterns of genetic variation, using proteins detected by starch gel electrophoresis and DNA content (ploidy) measured by flow cytometry. Unique multi-locus protein banding patterns and differences in ploidy were used to exclude plants as members of the same clone. Individual clones averaged about 2 m in diameter and areas of prairie of 100 m² were calculated to contain an average of 31.8 genetic individuals.

Stability Of Mrna In The Hyperthermophilic Archaeon Sulfolobus Solfataricus, Elisabetta Bini, Vidula Dikshit, Kristi Dirksen, Melissa Drozda, Paul H. Blum

School of Biological Sciences: Faculty Publications

Archaea-like bacteria are prokaryotes but, in contrast, use eukaryotic-like systems for key aspects of DNA, RNA, and protein metabolism. mRNA is typically unstable in bacteria and stable in eukaryotes, but little information is available about mRNA half-lives in archaea. Because archaea are generally insensitive to antibiotics, examination of mRNA stability in the hyperthermophile, Sulfolobus solfataricus, required the identification of transcription inhibitors for half-life determinations. An improved lacS promoter-dependent in vitro transcription system was used to assess inhibitor action. Efficient inhibitors were distinguished as blocking both lacSp transcription in vitro and the incorporation of ³H-uracil into bulk RNA in …

Managing Runoff Following Manure Application, John E. Gilley, L. Mark Risse, Bahman Eghball

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Rainfall patterns, soil factors, topography, climate, and land use may all influence runoff. To minimize environmental concerns, excessive runoff should be avoided on areas where manure has been applied. Management practices used to control runoff include contouring, strip cropping, conservation tillage, terraces, and buffer strips. In some cases, secondary containment systems, sedimentation basins, or ponds may be necessary to collect runoff. More than one runoff-control practice may be necessary for protection in areas with high runoff potential. Soil properties, including infiltration, may be improved by manure application. The method, rate and timing of manure application should be considered to reduce …

Heat Curing Of Soy Protein Films At Selected Temperatures And Pressures, Ki Myong Kim, Curtis Weller, Milford Hanna, Aristippos Gennadios

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Vacuum and temperature effects on moisture content, water vapor permeability (WVP), color (L, a, b, and DE), tensile strength (TS), elongation (E), and total soluble matter (TSM) of soy protein isolate (SPI) films were examined. SPI films were cured at 60, 72.5, or 85 °C and at 101.3, 81.32, or 61.32 kPa for 24 h. As a result of heat-curing moisture content, WVP, E, and TSM decreased, and total color difference and TS increased. Pressure, individually and interactively with temperature, significantly affected film moisture content, TS, and TSM.

Manure As Carbon Source For Soil Improvement And Crop Production: Site-Specific Application, Bahman Eghball, Daniel Ginting, Charles A. Shapiro, James S. Schepers, Christopher J. Bauer

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Manure, a renewable resource, is an excellent source of nutrients that can be substituted for synthetic types of fertilizers. The C in manure can enhance the physical and chemical properties of soils, especially infertile soils, as these soils typically contain low levels of organic matter and nutrients. The objective of this study was to evaluate the effects of C and nutrients in manure on soil C dynamics and crop production. The treatments included applications of site-specific manure (SSM), uniform manure (UM), uniform commercial fertilizer, and a no treatment check. Field strips 40 ft (16 corn rows) wide and 2200 ft …

Compensation For Herbivory In Wild Sunflower: Response To Simulated Damage By The Head-Clipping Weevil, Diana Pilson, Karin L. Decker

Diana Pilson Publications

Herbivore damage is generally detrimental to plant fitness, and the evolutionary response of plant populations to damage can involve either increased resistance or increased tolerance. While characters that contribute to resistance, such as secondary chemicals and trichomes, are relatively well understood, characters that contribute to a plant’s ability to tolerate damage have received much less attention. Using Helianthus annuus (wild sunflower) and simulated damage of Haplorhynchites aeneus (head-clipping weevil) as a model system, we examined morphological characters and developmental processes that contribute to compensatory ability. We performed a factorial experiment that included three levels of damage (none, the first two, …

Review And Interpretation: Nitrogen Management Strategies To Reduce Nitrate Leaching In Tile-Drained Midwestern Soils, Dana L. Dinnes, Douglas L. Karlen, Dan B. Jaynes, Thomas C. Kaspar, Jerry L. Hatfield, Thomas S. Colvin, Cynthia A. Cambardella

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

Balancing the amount of N needed for optimum plant growth while minimizing the NO₃ that is transported to ground and surface waters remains a major challenge for everyone attempting to understand and improve agricultural nutrient use efficiency. Our objectives for this review are to examine how changes in agricultural management practices during the past century have affected N in Midwestern soils and to identify the types of research and management practices needed to reduce the potential for nonpoint NO₃ leakage into water resources. Inherent soil characteristics and management practices contributing to nonpoint NO₃ loss from Midwestern soils, …

Chronological Age-Grading Of House Flies By Using Near-Infrared Spectroscopy, Joel Perez-Mendoza, Floyd E. Dowell, Alberto B. Broce, James E. Throne, Robert A. Wirtz, Feng Xie, Jeffrey A. Fabrick, James E. Baker

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

The sensitivity and accuracy of near-infrared spectroscopy (NIRS) was compared with that of the pteridine fluorescence technique for estimating the chronological age of house flies, Musca domestica (L.). Although results with both techniques were significantly correlated with fly age, confidence limits on predicted ages generally were smaller with NIRS. Young flies could be readily differentiated from old flies by using NIRS. Age predictions using the pteridine method are dependent upon size, sex, and temperature at which adult flies are exposed. In contrast, those factors do not need to be determined for age-grading using NIRS. Classification accuracy using the NIRS method …

Technology Knowledge And Use: A Survey Of Science Educators, A. Louis Odom, John Settlage, Jon E. Pedersen

Department of Teaching, Learning, and Teacher Education: Faculty Publications

The purpose of this study was to determine the current state of technology use and know-how among members of the Association for the Education of Teachers in Science. A web-based survey site and an e-mail merge invited members to participate in the study. The survey examined the differences between current and desired levels of knowledge about using technology as an instructional tool, to support research, to enhance productivity in classroom applications, and to enhance data collection and analysis. Large mean differences about using technology as an instructional tool were found, including: (1) teaching students at a distance, (2) database applications, …