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Keys And Distributional Maps For Nebraska Cyperaceae, Part 1: Bulbostylis, Cyperus, Dulichium, Eleocharis, Eriophorum, Fimbristylis, Fuirena, Lipocarpha, And Scirpus, Steven B. Rolfsmeier

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

Keys and distributional maps are provided for nine genera and 43 species of Cyperaceae documented from Nebraska (excluding Carex). Two species--Eleocharis elliptica and Fimbristylis vahlii--are newly reported for the state, while seven species attributed to the state in the Flora of the Great Plains (Great Plains Flora Association, 1986)--Eleocharis compressa, E. verrucosa, E. wolfii, E. xyridiformis, Scirpus georgianus, S. smithii, and S. torreyi--are deleted based on re-identifications, lack of specimen evidence, or specimens of doubtful provenance in the state. Notes on local systematic problems within the family are also included.

Dissociation Quotients Of Succinic Acid In Aqueous Sodium Chloride Media To 225°C, Richard Kettler, Donald A. Palmer, David J. Wesolowski

Department of Earth and Atmospheric Sciences: Faculty Publications

The first and second molal dissociation quotients of succinic acid were measured potentiometrically with a hydrogen-electrode, concentration cell. These measurements were carried out from 0 to 225"C over 25 ° intervals at five ionic strengths ranging from 0.1 to 5.0 molal (NaCl). The dissociation quotients from this and two other studies were combined and treated with empirical equations to yield the following thermodynamic quantities for the first acid dissociation equilibrium at 25°C: logK_1a = -4.210±0.003; Δ H_1̊a = 2.9±0.2 kJ-mol ^{- 1} ; ΔS_1̊a = -71±1 J-mol ^{- 1} -K ^-1; and ΔC_p̊,1a = -98±3 …

Principles And History Of Turfgrass Pest Management, Frederick P. Baxendale, Jennifer A. Grant

Department of Entomology: Faculty Publications

The importance of developing efficient and environmentally sound methods for managing turf grass pests has been reemphasized by recent concerns over environmental safety, the loss of long-term residual insecticides, and a growing awareness of the problems associated with the overuse of pesticides. Integrated pest management (IPM) addresses these concerns while maintaining the aesthetic and utilitarian qualities of the turf IPM is an approach that utilizes all suitable methods and techniques in a compatible manner to maintain pest densities below levels causing unacceptable damage. Although insects and mites are discussed in this handbook, the same management principles apply to other turf …

Statistical Sirens: The Allure Of Nonparametrics, Douglas H. Johnson

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

Although nonparametric statistical methods have a role to play in the analysis of data, often their virtues are overstated and their deficiencies overlooked. A recent Special Feature in Ecology advocated nonparametric methods because of an erroneously stated advantage that they require no assumptions regarding the distribution underlying the observations. The present paper points out some often-ignored features of nonparametric tests comparing two means, and advocates parameter estimation as a preferred alternative to hypothesis testing in many situations.

Using Known Populations Of Pronghorn To Evaluate Sampling Plans And Estimators, Kathy M. Kraft, Douglas H. Johnson, Jack M. Samuelson, Stephen H. Allen

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

Although sampling plans and estimators of abundance have good theoretical properties, their performance in real situations is rarely assessed because true population sizes are unknown. We evaluated widely used sampling plans and estimators of population size on 3 known clustered distributions of pronghorn (Antilocapra americana). Our criteria were accuracy of the estimate, coverage of 95% confidence intervals, and cost. Sampling plans were combinations of sampling intensities (16, 33, and 50%), sample selection (simple random sampling without replacement, systematic sampling, and probability proportional to size sampling with replacement), and stratification. We paired sampling plans with suitable estimators (simple, ratio, …

A Ten-Year History Of The Demography And Productivity Of An Arctic Wolf Pack, L. David Mech

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

A pack of two to eight adult wolves (Canis lupus arctos) and their pups was observed during ten summers (1986–95) on Ellesmere Island, Northwest Territories, Canada. The author habituated the wolf pack to his presence in the first summer and reinforced the habituation each summer thereafter. The first alpha female produced four to six pups each year between 1986 and 1989. However, her daughter, who succeeded her as the alpha female, produced only one to three pups each year between 1990 and 1992 and in 1994, and apparently did not whelp in 1993 or in 1995. The tenure …

Method Of Protecting Plants From Insects By Applying Gypsy Moth Virus With Enhamced Polyhedra Production Stability, James M. Slavicek, Melissa J. Mercer

United States Department of Agriculture, Forest Service / University of Nebraska-Lincoln: Faculty Publications

A virus having the identifying characteristics of ATCC VR2396 is disclosed. This virus has the trait of enhanced polyhedra production stability and resists forming a few polyhedra mutant virus. A method of protecting crops from insects comprising applying an insecticidally effective amount of virus having the identifying characteristics of ATCC VR2396 is also disclosed.

Modified Transmitter Attachment Method For Adult Ducks, Pamela J. Pietz, David A. Brandt, Gary L. Krapu, Deborah A. Buhl

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

The value of radio telemetry for waterfowl research depends on the availability of suitable methods of attaching transmitters. In previous studies, external transmitters attached to adult Mallards (Anas platyrhynchos) with sutures and glue did not stay on birds reliably. In an attempt to improve transmitter retention, a method of attachment was tested in which 4-g transmitters were attached mid-dorsally with sutures and with a stainless steel anchor-shaped wire inserted subcutaneously (anchor transmitters). Field tests indicated that all of 26 female Mallards and 63 of 65 female Gadwalls (Anas strepera) retained their anchor transmitters during 4369 bird-days …

Effects Of Climate On Numbers Of Northern Prairie Wetlands, Diane Larson

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

The amount of water held in individual wetland basins depends not only on local climate patterns but also on groundwater flow regime, soil permeability, and basin size. Most wetland basins in the northern prairies hold water in some years and are dry in others. To assess the potential effect of climate change on the number of wetland basins holding water in a given year, one must first determine how much of the variability in number of wet basins is accounted for by climatic variables. I used multiple linear regression to examine the relationship between climate variables and percentage of wet …

Certain Canine Weakly Β-Hemolytic Intestinal Spirochetes Are Phenotypically And Genotypically Related To Spirochetes Associated With Human And Porcine Intestinal Spirochetosis, Gerald E. Duhamel, Nagaraja Muniappa, Michelle R. Mathiesen, J. L. Johnson, J. Toth, R. O. Elder, A. R. Doster

School of Veterinary and Biomedical Sciences: Faculty Publications

Four canine weakly β-hemolytic intestinal spirochetes associated with intestinal spirochetosis (IS-associated WBHIS) were compared with IS-associated human and porcine WBHIS and the type species for Serpulina hyodysenteriae and S. innocens by using phenotypic and genotypic parameters. The IS-associated canine, human, and porcine WBHIS belonged to a phyletic group distinct from but related to previously described Serpulina type species.

Birds Of The Platte, Eileen M. Kirsch

United States Geological Survey: Staff Publications

Gary Lingle has done an outstanding job compiling information to make birding the Central Platte River and Rainwater Basin area of Nebraska easier and more rewarding. The book was not designed to replace a field guide. Rather, it provides maps, general information about the area, when and where birds can be seen, and likelihood of viewing each of 300 bird species possible. Sprinkled throughout the book are drawings by William S. Whitney and Ernest V. Ochsner that depict the structural simplicity of the prairie and the diversity of its wildlife. The writing style is personal and unpretentious, and the text …

Trees On The Great Plains: Agro-Ecosystem Diversity, Laurie Hodges, Mary Ellen Dix, James R. Brandle, Mark O. Harrell, Robert J. Wright, Ron J. Johnson, Ronald M. Case, Kenneth G. Hubbard, Linda J. Young, Rebecca L. Fitzmaurice, Nathalie J. Sunderman, Michele M. Schoeneberger

Department of Agronomy and Horticulture: Faculty Publications

Agriculture in the Great Plains faces increasing pressure for environmental stewardship and for more economical farming and pest management practices. The concept of sustainable agriculture was developed to address these needs. A sustainable agricultural system is one that consistently enhances environmental quality and the resource bases, provides basic human food and fiber needs, is economically viable, and enhances the quality of life for farmers and society. In the Great Plains, we define agroforestry as the use of trees to help make agricultural production systems more sustainable. The trees function to conserve soil, water, wildlife, and other natural resources. They also …

Classical And Molecular Approaches To Breeding Horticultural Plants For Disease Resistance: Introduction To The Colloquium, Dermot P. Coyne

Department of Agronomy and Horticulture: Faculty Publications

Diseases of horticultural crops have always been a concern of crop producers, processors, merchandisers, and consumers because of reductions in yield and product quality. Excessive chemical application to control diseases of some crops has been a health concern in some countries. Some diseases pose a major constraint, or even a threat, to the production of a crop in a region. Plant breeders, in association with plant pathologists, have had notable successes in breeding disease-resistant varieties, thus ensuring the economic production of a crop. There is now an increased need to breed for disease resistance of horticultural crops because of a …

Adaptability And Reliability Of Yield For Four Bell Pepper Cultivars Across Three Southeastern States, Laurie Hodges, Douglas Sanders, Katharine Perry, Kent M. Eskridge, K.M. Dean Batal, Darbie M. Granberry, Wayne J. Mclaurin, Dennis Decoteau, Robert Dufault, J. Thomas Garrett, Russell Nagata

Department of Agronomy and Horticulture: Faculty Publications

(Capsicum annuum L.) cultivars were evaluated for yield (total weight of marketable fruit) performance over 41 environments as combinations of 3 years, three planting dates, and seven locations across North Carolina, South Carolina, and Georgia. Cultural practices, including trickle irrigation and double rows planted on blackplastic- covered beds, were uniform across all environments, except for fertilization, which was adjusted at each location based on soil tests. Comparing production over 3 years between the mountain location and the Coastal Plain location in North Carolina, yields were lower on the Coastal Plain. Spring plantings provided higher yields than summer plantings at …

In Vitro Starch Disappearance Procedure Modifications, C. J. Richards, Jeffrey F. Pedersen, R. A. Britton, R. A. Stock, C. R. Krehbiel

Department of Agronomy and Horticulture: Faculty Publications

Four in vitro experiments evaluated the effects of ruminal fluid inoculum:artificial saliva ratios,

grinder type, grind size, and diet of ruminal fluid donor on in vitro starch disappearance. Experiment 1 examined rates of starch disappearance and coefficients of determination obtained by linear regression of starch disappearance using five grain sorghum (Sorghum bicolur (L.) Moench) lines, a corn (Zeu muys L.) control, and a wheat (Triticum aestivum L.) control. Grains were incubated for 4, 8, 12, 16, and 20 h with inoculum varying in proportion of ruminal fluid and artificial saliva ( l:l, 1:2, 1:3, and 1:4). In …

Soy Protein Isolate/Poly(Ethylene Oxide) Films, V. M. Ghorpade, A. Gennadios, M. A. Hanna, Curtis L. Weller

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Films were prepared by casting and drying alkaline aqueous film-forming solutions of soy protein isolate (SPI). Four additional types of films were made by combining SPI with poly(ethylene oxide) (PEO) in SPI to PEO ratios of 19:1, 9:1, 4:1, and 1.5:1 (w/w). Glycerin was added to all film-forming solutions as a plasticizer at 60% of total solid weight. Addition of PEO decreased film tensile strength (TS) and increased elongation at break (E). TS values ranged from 1.4 to 3.9 MPa and E values ranged from 83 to 152%. Water vapor permeability of the films ranged from 3.0 x 10^{-9 …}

Thermomechanical Behavior Of Wheat Gluten Films: Effect Of Sucrose, Glycerin, And Sorbitol, George Cherian, Aristippos Gennadios, Curtis L. Weller, Pavinee Chinachoti

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Glass transition temperature (T_g) and mechanical and water vapor barrier properties of wheat gluten films containing glycerin, sucrose, glycerin-sucrose, and glycerin-sorbitol were studied. Glycerin and sucrose were immiscible; the wheat gluten film containing both solutes showed two separate thermal transitions (-58°C and -5°C, respectively). The low temperature (low-T) transition (-58°C) was due to a glycerin-rich region. The low-T tan δ peak height influenced the tensile strength and elongation linearly and the water vapor permeability (WVP) curvilinearly. However, the T_g failed to change with solute composition and exhibited low correlation with barrier and mechanical …

Darcy-Weisbach Roughness Coefficients For Surfaces With Residue And Gravel Cover, John E. Gilley, Eugene R. Kottwitz

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Several types of hydraulic resistance factors may be present on upland agricultural areas. It is not known whether roughness contributions from individual elements are additive or if interactions between resistance factors may occur. In this study, Darcy-Weisbach roughness coefficients were measured on surfaces containing corn-soybeans, sorghum-cotton, and sunflower-wheat residue in addition to gravel cover. Varying rates of flow were introduced into a flume in which residue and gravel materials were securely attached. Roughness coefficients were calculated from measurements of discharge rate and flow velocity for Reynolds number values varying from approximately 1,200 to 13,000. The laboratory data were then used …

Auger Design For Uniform Unloading Of Granular Material: I. Rectangular Cross-Section Containers, David D. Jones, Michael F. Kocher

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Design equations were developed for two auger configurations that for practical purposes generate uniform vertical flow of granular material through containers or boxes having a rectangular cross-section. Both configurations have uniform outside diameters so the simple geometry of the conventional U-trough housings could be used with these augers. One configuration had a uniform pitch for the auger flighting and decreasing inside diameter. The other had a uniform inside diameter and a decreasing pitch of the flighting with distance from the outlet end of the auger. Both configurations dramatically improved the uniformity of flow over the conventional auger. However, confidence intervals …

Auger Design For Uniform Unloading Of Granular Material: Ii. Cylindrical Containers, Michael F. Kocher, David D. Jones

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The analysis presented can be used to determine the design equations for augers that produce uniform vertical flow of granular material through containers with cylindrical cross-sections. The augers so designed have a constant outside diameter and a variable root or shaft diameter. Installed in cylindrical grain bins they could be used to convert a batch-in-bin dryer to a continuous flow dryer. The analysis is an extension of the work of Jones and Kocher (1995) who designed and tested such an auger for containers of rectangular cross-section, and determined flow to be uniform for practical purposes. The analysis follows the same …

Corn Residue Cover On The Soil Surface After Planting For Various Tillage And Planting Systems, David P. Shelton, Elbert C. Dickey, Stephen D. Kachman, K.T. Fairbanks

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Crop residue left on the soil surface after planting is one of the most cost-effective soil erosion control practices, and is a primary component of the majority of conservation plan that have been developed to comply with the conservation provisions of the 1985 Food Security Act. However, from contacts in Extension meetings and demonstrations, it became apparent that formers frequently misunderstood certain aspects of crop residue management, particularly the effects that tillage and other operations had on residue cover. To help address some of these questions, we measured percent residue cover remaining on the soil surface after planting for 69 …

Solid Waste Disposal Site Characterization Using Non-Intrusive Electromagnetic Survey Techniques And Geostatistics, Gary N. Kuhn, Wayne E. Woldt, David D. Jones, Dennis D. Schulte

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Prior to the research reported in this paper, a site-specific hydrogeologic investigation was developed for a closed solid waste facility in Eastern Nebraska using phased subsurface characterizations. Based on the findings of this prior investigation, a surface based geoelectric survey using electromagnetic induction to measure subsurface conductivity was implemented to delineate the vertical and horizontal extent of buffed waste and subsurface contamination. This technique proved to be a key non-intrusive, cost-effective element in the refinement of the second phase of the hydrogeologic investigation.

Three-dimensional ordinary kriging was used to estimate conductivity values at unsampled locations. These estimates were utilized to …

Performance Of Four Seed-Caching Corvid Species In Operant Tests Of Nonspatial And Spatial Memory, Deborah J. Olsen, Alan Kamil, Russell P. Balda, Pamela J. Nims

Papers in Behavior in Biological Sciences

The performance of 4 seed-caching corvid species was tested using 2 different operant nonmatching tasks. These species differ in their dependence on stored food, and differences in spatial memory tests have been correlated with better performance by the more cache-dependent species. Acquisition and retention of a color non-matching-to-sample task was tested in Experiment 1. Acquisition of the color task was not correlated with cache dependence, and no differences between species in performance during memory testing were found. Acquisition and retention of an operant spatial non-matching-to-sample task was tested in Experiment 2. Species differences in the spatial task were found for …

In Vivo Regulation Of Wheat-Leaf Phosphoenolpyruvate Carboxylase By Reversible Phosphorylation, Stephen M. G. Duff, Raymond Chollet

Department of Biochemistry: Faculty Publications

Regulation of C₃ phosphoenolpyruvate carboxylase (PEPC) and its protein-serine/threonine kinase (PEPC-PK) was studied in wheat (Trificum aesfivum) leaves that were excised from low-N-grown seedlings and subsequently illuminated and/or supplied with 40 mM KNO₃. The apparent phosphorylation status of PEPC was assessed by its sensitivity to i-malate inhibition at suboptimal assay conditions, and the activity state of PEPC-PK was determined by the in vitro ³²P labeling of purified maize dephospho-PEPC by [y³²PIATP/ Mg. lllumination (±NO₃^-) for 1 h led to about a 4.5-fold increase in the 50% inhibition constant for i-malate, which …

Dephosphorylation Of The Thylakoid Membrane Light-Harvesting Complex-Ii By A Stromal Protein Phosphatase, Mark E. Hammer, Gautam Sarath, John Markwell

Gautam Sarath Publications

Light-harvesting complex-II (LHC-II) phosphatase activity has generally been examined in the intact thylakoid membrane. A recent report of peptide-phosphatase activity associated with the chloroplast stromal fraction (Hammer, M.E et al. (1995) Photosynth Res 44:107–115) has led to the question of whether this activity is capable of dephosphorylating membrane-bound LHC-II. To this end, heat-treated thylakoid membranes were examined as a potential LHC-II phosphatase substrate. Following incubation of the thylakoid membrane at 60 °C for 15 min, the endogenous protein phosphatase and kinase activities were almost eliminated. Heat-inactivated phosphomembranes exhibited minimal dephosphorylation of the light harvesting complex-II. Peptide-phosphatase activities isolated from the …

Syrphids As Natural Enemies Of Cereal Aphids In Germany: Aspects Of Their Biology And Efficacy In Different Years And Regions, Brigitte Tenhumberg, Hans-Michael Poehling

School of Biological Sciences: Faculty Publications

An evaluation was made of the influence of aphidophagous syrphid larvae on the population dynamics of cereal aphids in winter wheat in Germany, using both field records and published information. The peak density of aphid populations was significantly dependent on aphid abundance at the time syrphid larvae became active, a fact indicating the high predation potential of the beneficials as well as the importance of synchronization. The level of aphid infestation was generally lower in southern than in northern Germany. This difference may result from syrphid larvae being 2-3 weeks earlier in southern Germany, when aphid numbers were only half …

Submaximal Oviposition Rates In A Mymarid Parasitoid: Choosiness Should Not Be Ignored, Amos Bouskila, Ian C. Robertson, Michael E. Robinson, Bernard D. Roitberg, Brigitte Tenhumberg, Andrew J. Tyre, Ed Vanranden

School of Biological Sciences: Faculty Publications

Cronin and Strong (1993a, b) examined the oviposition behavior of Anagarus delicatus Dozier (Hymenoptera: Mymaridae), an egg parasitoid of the leafhopper Prokelisia marginate Van Duzee (Homoptera: Delphacidae). They reported oviposition rates that were lower than predicted if the rate of egg-laying was maximized. Cronin and Strong (1993a) considered, and subsequently rejected, several “rules of thumb” (Stephens and Krebs 1986) as explanations for the observed patterns of patch departure. They observed that hosts on leaves experience density-independent mortality due to leaf senescence. Based on that, they advanced the hypothesis that submaximal oviposition rates in A. delicatus are best explained as risk-spreading …

Estimating Predatory Efficiency Of Episyrphus Balteatus (Diptera: Syrphidae) In Cereal Fields, Brigitte Tenhumberg

School of Biological Sciences: Faculty Publications

A model was developed to estimate the effect of predation by Episyrphus balteatus larvae on aphid populations in fields of winter wheat. Feeding rate of syrphid larvae was estimated from experiments in field cages using a Holling type-III function. During larval development, syrphids consumed a maximum of 396 aphids, which is only half the potential feeding rate reported from laboratory experiments. The lower consumption rate in the field may be attributed to the additional time required by the predators to find prey. Isoclines derived from the model were used to estimate the abundance of syrphid larvae necessary to prevent further …

Repeatability Of Maximal Aerobic Performance In Belding’S Ground Squirrels, Spermophilus Beldingi, M. A. Chappell, Gwendolyn C. Bachman, J. P. Odell

School of Biological Sciences: Faculty Publications

1. The repeatability of a trait is a critical factor in determining how that trait is affected by natural selection. We examined the repeatability of a key physiological trait, maximum oxygen consumption (VO_2max), in a wild population of Belding’s Ground Squirrels, Spermophilus beldingi. VO_2max is an integrated measure of organismal metabolic performance. It can be intuitively related to fitness because it sets an upper limit to sustainable power output during ecologically important activites such as locomotion and thermoregulatory heat production.

2. We used respirometry to determine VO_2max during exercise and thermogenesis. Exercise VO …

Getting The Lay Of The Land: Introducing North American Native Grasslands, Anthony Joern, Kathleen H. Keeler

School of Biological Sciences: Faculty Publications

The expected catastrophic extinction of species (already under way in many places) will alter the planet’s biological diversity so profoundly that, at the known rate of extinction, it will take millions of years to recover. Yet few ecologists study extinction. Indeed, very little ecology deals with any processes that last more than a few years, involve more than a handful of species, and cover an area of more than a few hectares. The temporal, spatial and organizational scales of most ecological studies are such that one can read entire issues of major journals and see no hint of impending catastrophe. …