Digital Commons Network^™

Factors Affecting Attwater's Prairie-Chicken Decline On The Attwater Prairie Chicken, Michael E. Morrow, Robert S. Adamcik, Jenny D. Friday, Lloyd B. Mckinney

United States Geological Survey: Staff Publications

We examined the association between changes in the number of Attwater's prairie-chicken (Tympanuchus cupido attwateri) on the Attwater Prairie Chicken National Wildlife Refuge from 1972 to 1993 and changes in refuge management practices (burning and grazing). We also examined the relationship of prairie-chicken population increases and decreases on the refuge to rainfall and off-refuge prairie-chicken populations. Burning within the prairie-chicken's core habitat on the refuge and variability in grassland structure were directly correlated (P < 0.05) with increases and declines in prairie-chicken populations. Refuge population increases and declines were inversely correlated (P < 0.1) with average April rainfall/event, May absolute departure from long-term average rainfall, May number of rainfall events, annual absolute departure of rainfall from the long-term average, and the annual number of rainfall events. Refuge population increases and declines were directly correlated (P < 0.1) with off-refuge populations, although the off- refuge population decline began 4 years earlier than on-refuge.

Analysis Of Aerial Photography For Nitrogen Stress Within Corn Fields, Tracy M. Blackmer, James S. Schepers, Gary E. Varvel, George Meyer

Department of Agronomy and Horticulture: Faculty Publications

Spatial variability of soil parameters within fields complicates N fertilizer recommendations for corn (Zea mays L.) production. Thus, the ability to identify differences in crop N status within corn fields could lead to efficiencies in N fertilizer application and decreased ground water pollution. In this study, we digitized aerial color photographic transparencies using an eight-bit scheme to generate digital counts for the red, green, and blue primary colors in the photographs at the R5 growth stage and related them to grain yield. Digital count responses were relative to the N treatment in which grain yield plateaued. Experiments were conducted …

Annual Forages: New Approaches For C-4 Forages, Jeffrey F. Pedersen

Department of Agronomy and Horticulture: Faculty Publications

The current agricultural paradigm in the U.S. is heavily biased towards the production and marketing of crops as commodities. This paradigm is kept in place by grain handling and marketing infrastructure, as well as government farm programs, designed for crops as commodities. Sorghum (Sorghum bicolor L. Moench) and maize (Zea mays L.) grown for grain certainly fit into this current paradigm.

A new approach to agricultural production and marketing, identity preserved products, is gaining in importance. This is made possible through new technologies and markets demanding products designed specifically for their needs. Examples of investment in identity preserved …

Breeding Sorghum And Pearl Millet For Forage And Fuel, Jeffrey F. Pedersen

Department of Agronomy and Horticulture: Faculty Publications

Sorghum [Sorghum bicolor (L.) Moench] and pearl millet [Pennisetum glaucum (L.) R. Br.] are unique species in their ability to be used in many forage llivestock system roles. Such flexibility has made prioritizing breeding objectives difficult and has even contributed to contradictory opinions on appropriate forage breeding objectives. Few breeding projects identified in the USDA-ARS, USDA-CREES, or at ICRISAT had forage sorghum or forage pearl millet as their sole research assignment. In the United States, it can be argued that breeding resources committed to forage sorghum improvement are probably declining. A new forage sorghum and forage pearl millet …

Media Effects On Phenotype Of Callus Cultures Initiated From Photoperiod-Insensitive, Elite Inbred Sorghum Lines, H. F. Kaeppler, Jeffrey F. Pedersen

Department of Agronomy and Horticulture: Faculty Publications

Sorghum (Sorghum bicolor L. Moench) is a crop of worldwide agronomic importance. Routine production of high quality (friable, embryogenic, fast growing) callus cultures is fundamental to tissue culture based genetic study and improvement of sorghum. Genotype by culture medium interactions for sorghum callus growth and morphology have been previously reported. The objective of this study was to identify tissue culture media that would support high quality callus growth across photoperiod insensitive, relatively elite genotypes. Explants from immature inflorescences of 11 sorghum genotypes were cultured on 6 tissue culture media of differing composition. After 3 and 5 months in culture, calli …

Grazing And Haying Effects On Runoff And Erosion From A Former Conservation Reserve Program Site, John E. Gilley, B. D. Patton, P. E. Nyren, J. R. Simanton

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Grazing and haying effects on runoff and erosion from a former Conservation Reserve Program (CRP) site near Streeter, North Dakota, were determined. Treatments included undisturbed CRP, twice-over rotational grazing, season-long grazing, haying, and burning. Runoff and erosion were measured from simulated rainfall which was applied to 3.7 x 10.7 m (12.0 X 35.1 ft) plots. Following an initial stabilization period, no significant difference in runoff or erosion was found between the season-long grazing and burned treatments. Use of the CRP site for grazing or haying resulted in a significant increase in runoff compared to leaving the area in an undisturbed …

Frequency Domain Image Analysis For Detecting Stress Cracks In Corn Kernels, Y. J. Han, Y. Feng, Curtis L. Weller

Department of Agricultural and Biological Systems Engineering: Faculty Publications

A corn kernel classification procedure was developed in the frequency domain using a two-dimensional Fourier Transform for inspection of stress cracks. Investigations were also conducted to define suitable conditions and optimum image resolution for viewing stress cracks in corn kernels using a computer vision system. A pre-processing procedure included contrast enhancement, edge enhancement, and kernel edge elimination to improve stress crack recognition. A Fast Fourier Transform algorithm was applied to the pre-processed images, and the transformation results were condensed into 33 feature signatures representing position or orientation invariant morphological features. A multivariate discriminant analysis and multiple regression analysis were used …

Heat Curing Of Soy Protein Films, A. Gennadios, V. M. Ghorpade, Curtis L. Weller, M. A. Hanna

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Modification of soy protein film properties by heat-curing was studied. Glycerin-plasticized films were cast from alkaline aqueous solutions of soy protein isolate. Films were heated at 80 or 95°C for 2, 6, 14, or 24 h. Tensile strength (TS), elongation at break (E), moisture content (MC), water solubility (WS), water vapor permeability (WVP), and color of heated and control films were measured. Heated films had increased TS and +b (yellowness) Hunter color values and reduced E, MC, WS, and WVP values. These effects were enhanced as heating time and temperature increased.

Metering Characteristics Accompanying Rate Changes Necessary For Precision Farming, A. Bahri, K. Von Bargen, Michael F. Kocher, L. L. Bashford

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Agricultural machines used in precision fanning must adjust application rates according to the needs of each cell within a field. Changing from an initial application rate to a new rate while the machine travels from one cell to another in the field is accompanied with some misapplication. The severity of this misapplication depends on the down-the-row delivery characteristics of the metering system and the magnitude of the rate change from cell to cell.

On-the-go rate change tests evaluated the down-the-row performance of an operator controlled metering system when increasing and decreasing wheat seeding rates by 10 and 20 kg/ha steps. …

Spatial Patterns Analysis Of Field Measured Soil Nitrate, Farida Shaukat Goderya, Mohamed F. Dahab, Wayne E. Woldt, Istvan Bogardi

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The purpose of this study was to assess the spatial variability of residual soil nitrate, measured in three contiguous 16 ha fields. Available data for residual soil nitrate were examined using conventional statistics. Data tended to be skewed with the mean greater than the median. Geostatistical methods were used to characterize and model the spatial structure. Three dimensional spatial variability was examined using two semivariograms: horizontal-spatial and vertical. Two dimensional horizontal-spatial semivariograms were also computed for each 0.3m (1ft) layer. Semivariogram analysis showed that there were similarities in the patterns of spatial variability for all fields. The results suggest that …

Predicting Cognitive Capacity From Natural History: Examples From Four Species Of Corvids, Russell P. Balda, Alan Kamil, Peter A. Bednekoff

Papers in Behavior in Biological Sciences

Birds have been studied for centuries because they are numerous, conspicuous, and aesthetically pleasing to humans. Despite their overall regard for birds, historically, many ornithologists have considered birds as instinct-driven organisms of little intellectual capacity. For example, the ornithological textbook of choice from the 1960s states the following view of avian intelligence:

Flight has proven to be an enormously successful evolutionary venture, but one that has cost birds dearly in mental development. In effect, problems merely by flying away from them. … As a consequence, much [avian] behavior is, by mammalian standards, fragmentary, stereotyped, and at times amazingly stupid. (Welty, …

Visual Search For Natural Grains In Pigeons (Columba Livia) : Search Images And Selective Attention, Cynthia M. Langley, Donald A. Riley, Alan B. Bond, Namni Goel

Papers in Behavior in Biological Sciences

The experiments reported here were designed to test the suggestion of many researchers that selective attention to visual features of a prey can account for search-image effects. In 3 experiments pigeons ate wheat and vetch grains presented on multicolored and gray gravel trays. In Experiment 1 search-image effects were evident when grains were cryptic but not when they were conspicuous. Experiment 2 demonstrated that search images can be activated when the grains encountered are either cryptic or conspicuous but that search images affect search performance only when the grains are cryptic. Experiment 3 demonstrated that search images are short-term in …

Role Of The Escherichia Coli Fadr Regulator In Stasis Survival And Growth Phase-Dependent Expression Of The Uspa, Fad, And Fab Genes, Anne Farewell, Alfredo A. Diez, Concetta C. Dirusso, Thomas Nyström

Department of Biochemistry: Faculty Publications

The increased expression of the uspA gene of Escherichia coli is an essential part of the cell’s response to growth arrest. We demonstrate that stationary-phase activation of the uspA promoter is in part dependent on growth phase-dependent inactivation or repression of the FadR regulator. Transcription of uspA is derepressed during exponential growth in fadR null mutants or by including the fatty acid oleate in the growth medium of FadR1 cells. The results of DNA footprinting analysis show that FadR binds downstream of the uspA promoter in the noncoding region. Thus, uspA is a member of the fadR regulon. All …

The Phylogenetic Distribution Of A Female Preference, Alexandra Basolo

School of Biological Sciences: Faculty Publications

Robust phylogenetic information can be instrumental to the study of the evolution of female mating preferences and preferred male traits. In this paper, the evolution of a preexisting female bias favoring a sword in male swordtail fish and the evolution of the sword, a complex character, are used to demonstrate how the evolution of mating preferences and preferred traits can be examined in a phylogenetic context. Phylogenetic information suggests that a preference for a sword arose prior to the evolution of the sword in the genus Xiphophorus and that the sword was adaptive at its origin. A phylogenetic approach to …

Movement Of Crop Transgenes Into Wild Plants, Kathleen H. Keeler, Charles E. Turner, Margaret R. Bolick

School of Biological Sciences: Faculty Publications

Despite the great potential and increasing importance of other weed control options (Turner et al. 1992) and unwanted environmental side effects of some herbicides, herbicides constitute a very important means of weed control. The escape of herbicide resistance genes to wild, weedy plants could cause more severe weed problems, and presents a very real threat to the efficacy of herbicides as a weed control option. Therefore, management strategies that prevent, or reduce the likelihood and frequency of HRG escape through containment methods are advisable, as are mitigation plans in the event of HRG escape to wild plants.

Pcr-Rflps Differentiate Mcconaughy And Kamloop Strains Of Rainbow Trout In Mixed Populations, Ronald L. Bromley, Douglas Siegel-Causey, Mike Cachelin, Richard S. Holland

School of Biological Sciences: Faculty Publications

Historically, rainbow trout have been an important component of the fishery in Lake McConaughy and its feeder streams in the North Platte River basin. Although numerous strains of rainbow trout have been introduced into this system, the migratory McConaughy strain has been credited for much of the past success of the fishery. The decline of this strain over the last three decades is a major concern. Genetic material representing these two rainbow trout strains were collected from fish taken from the U.S. Fish and Wildlife Service National Fish Hatchery at Innis, Montana. In this study, PCR-RFLP's (polymerase chain reaction-restriction fragment …

Pattern And Duration Of Copulation In Wolf Spiders (Araneae, Lycosidae), Gail E. Stratton, Eileen Hebets, Patricia R. Miller, Gary L. Miller

Eileen Hebets Publications

The temporal patterns of insertion of male palps, expansion of the hematodocha and duration of copulation are reported for 10 species of Schizocosa Chamberlin 1904, three species of Rabidosa Roewer 1955, one species of Gladicosa Brady 1986, one species of Hogna Simon 1885, two species of Isohogna Roewer 1960, one species of Trochosa C.L. Koch 1848, one species of Geolycosa Montgomery 1904, two species of Arctosn C.L. Koch 1848, three species of Alopecosa Simon 1885 and six species of Pardosa C.L. Koch 1847. In all species of Schizocosa examined so far, males showed a pattern composed of a series of …

Review Of Linda W. Davis, Weed Seeds Of The Great Plains, Svata M. Louda

Svata M. Louda Publications

The purpose of this useful 145-page book is to provide both a source of comparative information on seeds of 280 weedy plant species in the Great Plains and a means of identifying them. ... The 286 color photographs are the most valuable part of the book. ... Overall, I am delighted to have this book and recommend it to anyone who needs to identify weed seeds and, in fact, to anyone fascinated by the beauty and variation among plants displayed in nature.

Birds Of The Cedar Point Biological Station Area, Keith And Garden Counties, Nebraska: Seasonal Occurrence And Breeding Data, Charles R. Brown, Mary Bomberger Brown, Paul A. Johnsgard, Josef Kren, William C. Scharf

Papers in Ornithology

The North Platte River valley (elev. ca 3300 ft/990 m) in Garden and Keith counties, Nebraska, has an avifauna of 305 species, the richest known north of Texas in the Great Plains. More than 25 years of observations, mist-netting, banding, and breeding-bird surveys by the authors and others have revealed 104 breeding, 17 probably breeding, and 184 transient, casual, and accidental species. Hybridization of eastern with western species is evidenced by intermediates between Rose-breasted and Black-headed grosbeaks, Indigo and Lazuli buntings, Eastern and Spotted towhees, Baltimore and Bullock’s orioles, and yellow- and red-shafted morphs of Northern Flicker; Eastern and Western …

Field Parasitology Techniques For Use With Mammals, Scott Lyell Gardner

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Obtaining parasites from mammals that are collected during surveys or bioinventories is time-consuming, and in the past such collections have rarely been made. Parasites and other symbionts are important components of the biology of the host, however, and must be sampled for a complete picture of its ecology and other aspects of its life history. For example, work on parasite diversity and biogeography of mammals in Bolivia (Gardner and Duszynski 1990; Gardner 1991: Gardner et al. 1991; Gardner and Campbell 1992a, 1992b) could not have been accomplished without proper collections of the parasite and symbiont fauna of the hosts.

Many …

Técnicas De Parasitología De Practicas De Campo Para El Uso Durante La Investigación De Mamíferos, Scott Lyell Gardner

Harold W. Manter Laboratory of Parasitology: Faculty Publications

First paragraph of the introduction:

La obtención de parásitos de mamíferos que son colectados durante las investigaciones o bio-inventarios toma mucho tiempo; y en el pasado, estas colectas ráramente se realizaban. De cualquier forma, los parásitos y otros simbiotas forman un componente importante de las características biologicas y ecologicas de los hospederos y deben ser muestreados. Por ejemplo, trabajos recientes en la diversidad parasitaria y la biogeografía en mamíferos de Bolivia por Gardner y Duszynski (1990), Gardner (1991), y Gardner y Campbell (1992 a,b) no hubiera popdido realizarse sin el trabajo de colección apropiado de la fauna parasitaria/simbiótica de los …

Faunal Diversity Among Avian Parasite Assemblages: The Interaction Of History, Ecology, And Biogeography In Marine Systems, Eric P. Hoberg

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Systematics and parasite biodiversity provide power and predictability in broad studies of history, ecology and biogeography in marine systems. Parasitic helminths are elegant markers of contemporary and historical ecological relationships, geographic distribution and host-phylogeny. Complex life cycles of helminths are strongly correlated with intricate food-webs. Dependence on a series of intermediate, paratenic, and definitive hosts indicates that each parasite species represents an array of organisms within a community and tracks broadly and predictably across many trophic levels. Host and geographic ranges of parasites are historically constrained by genealogical and ecological associations, and these determinents interact resulting in characteristic parasite community …

Microevolutionary Patterns And Molecular Markers: The Genetics Of Geographic Variation In Ascaris Suum, Steven A. Nadler

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Molecular markers have been used only rarely to characterize the population genetic structure of nematodes. Published studies have suggested that different taxa may show distinct genetic architectures. Isoenzyme and RAPD markers have been used to investigate geographic variation of Ascaris suum at the level of infrapopulations (nematodes within individual hosts), within localities, and among geographic regions. Independent estimates of genetic differentiation among population samples based on isoenzyme and RAPD data showed similar patterns and substantial correlation. Heterozygote deficiencies within infrapopulations and large values for inbreeding coefficients among infrapopulations suggested that the composition of these populations was not consistent with a …

Analytical Perspectives On A Protohistoric Cache Of Ceramic Jars From The Lower Colorado Desert, James M. Bayman, Richard H. Hevly, Boma Johnson, Karl J. Reinhard, Richard Ryan

Karl Reinhard Publications

A cache of hermetically sealed ceramic jars found in the Lower Colorado Desert was examined using chronometric dating, pollen and macrofossil extraction, design analysis, and water retention experimentation. The cache apparently dates to the protohistoricfifteenth through seventeenth centuries. Findings from these studies contribute to knowledge in four problem areas: (1) ceramic jar function and use-history; (2) storage technology and caching behavior; (3) ceramic dating and chronology; and (4) symbolic iconography. Biotic remains from inside the jars document their use for transporting a variety of riverine and desert plants, before they were finally filled with flowers and seeds, and placed in …

Semiochemistry Of Cabbage Bugs (Heteroptera: Pentatomidae: Eurydema And Murgada, Jeffrey R. Aldrich, James W. Avery, Chang-Joo Lee, Jennifer C. Graf, Dawn J. Harrison, Ferdinando Bin

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

The semiochemistry of the common North American pest of crucifers, Murgantia histrionica (Hahn) (the harlequin bug), and two related European species, Eurydema ventrale L. and E. oleraceum L., was investigated.

Late Pliocene Diatoms In A Diatomite From Prydz Bay, East Antarctica, Albert D. Mahood, John A. Barron

United States Geological Survey: Staff Publications

Very well-preserved Pliocene diatoms from a diatomite unit interbedded within glacial sediments at Ocean Drilling Program Site 742 in Prydz Bay, Antarctica are documented and illustrated. The presence of Thalassiosira kolbei, T torokina, Actinocyclus actinochilus, A karstenii and the absence of Nitzschia interfrigidaria, T. insigna and T. vulnifica in Sample 119-742A-15R-4, 44-46 cm constrain its age to ca. 2.2-1.8 Ma (late Pliocene). Diatoms associated with sea ice constitute 35% of the Pliocene diatom assemblage, compared with 71% of the modern sediment assemblage at the site, suggesting that sea ice was present during the late Pliocene period of deposition of the …

Nematode Diversity Of Native Species Of Vitis In California, Luma Al-Banna, Scott Lyell Gardner

Harold W. Manter Laboratory of Parasitology: Faculty Publications

From 1990 through 1992, nematodes were extracted from soil samples taken from the rhizosphere of native species of grapes from four areas of northern California and two areas of southern California. For comparison, samples from domestic grapes as well as a putative hybrid of Vitis californicaand V. vinifera were also taken. Rhizosoil from California native grapevine contained many more species of nematodes than did soil obtained from cultivated forms of V. vinifera. Taxonomic and trophic diversity was much higher in nematodes from sampling sites from native grapes than in those from grapes maintained in vineyard situations. Ordination methods …

Body Size Evolution Of Oxyurid (Nematoda) Parasites: The Role Of Hosts, Serge Morand, Pierre Legendre, Scott Lyell Gardner, Jean-Pierre Hugot

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Studying the diversification of body size in a taxon of parasites allows comparison of patterns of variation observed in the parasites with patterns found in free-living organisms. The distributions of body size of oxyurid nematodes (obligate parasites of vertebrates and invertebrates) are lognormally right-skewed, except for male oxyurids in invertebrates which show left-skewed distributions. In these parasitic forms, speciose genera do not have the smallest body sizes. Parasite body size is positively correlated with host body size, the largest hosts possessing the largest parasites. This trend is shown to occur within one monophyletic group of oxyurids, those of Old World …

Identification Of Heterorhabditis (Nematoda: Heterorhabditidae) From California With A New Species Isolated From The Larvae Of The Ghost Moth Hepialis Californicus (Lepidoptera: Hepialidae) From The Bodega Bay Natural Reserve, S. Patricia Stock, Donald R. Strong, Scott Lyell Gardner

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Classical taxonomy together with cross-breeding tests and random amplified polymorphic DNA (RAPD's) were used to detect morphological and genetic variation between populations of Heterorhabditis Poinar, 1975 from California. A new species, Heterarhabditis hepialius sp. n., recovered from ghost moth caterpillars (Hepialis califamicus) in Bodega Bay, California, USA is herein described and illustrated. This is the eighth species in the genus Heterarhabditis and is characterized by the morphology of the spicules, gubernaculum, the female's tail, and ratios E and F of the infective juveniles. Information on its bionomics is provided.

French title: Identification d'Heterorhabditis (Nematoda: Heterorhabditidae) de Californie …

Gonadal Maturation In The Cobia Rachycentron Canadum From The Northcentral Gulf Of Mexico, Jeffrey M. Lotz, Robin M. Overstreet, James S, Franks

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Gonadal maturation of cobia, Rachycentron canadum, was evaluated by examining 508 specimens from its recreational fishery. Specimens were collected off southeast Louisiana to northwest Florida by hook-and-line during February through October 1987-1991. Fork lengths (FL) of these fish ranged from 580-1,530 mm, with corresponding weights of 2.0-43.5 kg. The female:male ratio was 1:0.37. Using a combination of oocyte size frequency and histological assessment of many of the fish, we determined that females were ripe from May through September, with atretic oocytes occurring in some fish from July through October. Degenerating hydrated oocytes in July and October and the presence …