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Stress-Strain Relation In Debris Flow Analysis, Chi-Hai Ling, Cheng-Lung Chen, Chyan-Deng Jan

United States Geological Survey: Staff Publications

In debris flow analysis, the generalized viscop1astic fluid (GVF) model can be used as the constitutive equations. When the yield stress is negligible, the shear expression in the GVF model for simple shear flow reduces to r = µ₁ (du/dz)ⁿ, where r is the shear stress, µ₁ is the consistency index, du/dz is the shear rate, and n is the flow behavior index. In this paper the r versus du/dz relation is studied by running experiments with 14 mm dry glass spheres in a conveyor-belt flume. A comparison of the estimated r with the measured du/dz …

Topographic Effects On Stormflow Acidity, David Wolock

United States Geological Survey: Staff Publications

This paper describes the theoretical and observed effects of topography on stormflow acidity in upland, forested watersheds. The theoretical effects were determined by a sensitivity analysis using the hydrologic model TOPMODEL. The observed effects were determined by an analysis of topographic and stormflow acidity data collected from eight watersheds in Wales, Great Britain. Results of the analyses indicated that the observed effects of topography were consistent with the theoretical expectations; that is, topography has an important effect on flow path, and that flow path, in turn, has an effect on stormflow acidity.

Network Applications Of The Usgs Branch Model, Raymond W. Schaffranek

United States Geological Survey: Staff Publications

Applications of a numerical model for simulating unsteady flow in dendritic or interconnected open-channel networks are presented to demonstrate the model's potential for addressing environmental problems and formulating engineering decisions in water-resources investigations. The model is computationally robust and readily adaptable to a broad spectrum of hydraulic conditions and open-channel configurations. The four-point, implicit, finite difference model has been implemented on numerous open-channel reaches and networks in support of various water-resources investigations conducted within the U.S. Geological Survey. In this paper, network applications of the model to a residential canal system in Cape Coral, Florida; to a distributary system of …

Modeling Flow And Flood-Plain Storage In A Tidally Affected River, A. G. Strickland, Jerad D. Bales

United States Geological Survey: Staff Publications

A one-dimensional, unsteady-flow model was calibrated, validated, and tested for a 30.4-mile reach of the tidally affected Roanoke River, North Carolina. The model includes a storage reservoir to represent the two-dimensional processes associated with flood-plain storage and release in the one-dimensional flow model. Simulated and measured water levels differed by less than 0.5 foot, and the average absolute difference between simulated and measured flows was 7 percent.

Incorporating Hydraulic Structures In An Open-Channel Model, Eric D. Swain

United States Geological Survey: Staff Publications

The open-channel flow model, BRANCH, is a routinely used numerical tool for modeling rivers, canals, and waterway networks. Although a simplified hydraulic structure representation is included in the model, no universal subroutine that can represent hydraulic structures by their rating curve equations has been included in the BRANCH model.

Accordingly, a subroutine has been developed that specifies flow through a structure by a stage-discharge relation. The structure flow equation is used to generate coefficients in the solution matrix that represent the structure in the same computational format as the open-channel flow equations. Field applications have shown that this new subroutine …

Field Reaction Of Landrace Components Of Red Mottled Common Bacterial Blight, James S. Beaver, James R. Steadman, Dermot P. Coyne

Department of Agronomy and Horticulture: Faculty Publications

Field reaction of 25 red mottled bean ( Phaseolus vulgaris L.) genotypes to common bacterial blight [Xanthomonas campestris pv. phaseoli (Smith) Dye] was evaluated in Puerto Rico over 2 years. The average disease severity (percent leaf area with symptoms) was similar over years. The determinate red mottled genotypes had almost twice as much disease as indeterminate genotypes. Eight of the indeterminate genotypes had significantly less disease than the mean of the field experiments. These genotypes may serve as useful sources of resistance to common bacterial blight. The size of the chlorotic zone around necrotic lesions varied between growing seasons, …

Pathogenicity Of Pseudomonas Gladioli Pv. Gladioli On Rhizomatous Iris And Its Possible Role In Iris Scorch, Annie L. Wrobel, John E. Watkins, Don Steinegger

Department of Agronomy and Horticulture: Faculty Publications

Scorch of rhizomatous iris, Iris spp., occurs throughout much of the United States (Black, 1984). It is characterized as a rustcolored browning that starts on the tips of the youngest leaves in the center of the fan. Leaf necrosis progresses downward on the leaves and outward on the fan until the entire fan is affected. Roots shrivel and decay. Root cortical tissue completely deteriorates, but the epidermis and stele remain intact. The rhizome appears unaffected (Wadekamper, 1972).

Because of the sporadic occurrence of scorch and the difficulty of artificially reproducing scorch symptoms, little is known about the etiology, epidemiology, or …

Jasmonate, Genes, And Fragrant Signals, Paul E. Staswick

Department of Agronomy and Horticulture: Faculty Publications

Although first recognized for its growth-inhibiting activity about 20 years ago, JA² and its fragrant methyl ester MeJA (referred to here collectively as jasmonate) are receiving renewed interest as potentially important signaling molecules in plants. This is because jasmonate markedly increases the expression of specific plant genes, some of which are wound responsive. Similarities with fatty acid-derived stress signaling molecules in animals (1) make jasmonate of general biological interest.

Darcy-Weisbach Roughness Coefficients For Gravel And Cobble Surfaces, John E. Gilley, Eugene R. Kottwitz, Gary A. Wieman

Department of Agricultural and Biological Systems Engineering: Presentations and White Papers

A laboratory study is conducted to measure Darcy-Weisbach roughness coefficients for selected gravel and cobble materials. Varying rates of flow are introduced into a flume in which a given size class of gravel or cobble material is securely attached. Roughness coefficients are calculated from measurements of discharge rate and flow velocity. The laboratory data are used to develop regression equations for relating roughness coefficients to surface cover and Reynolds number. Accurate prediction of roughness coefficients for gravel and cobble surfaces will improve our ability to understand and properly model upland flow hydraulics.

Sediment Delivery On Rill And Interrill Areas, John E. Gilley, D. C. Kincaid, W. J. Elliot, J. M. Laflen

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Equations which relate sediment delivery to a power function of flow rate and slope gradient were evaluated in this study. The data used to parameterize the calculations were obtained from sites where crop residues had been removed, and moldboard plowing and disking had occurred. Measurements of sediment delivery resulting from simulated rainfall were obtained from preformed rills and interrill areas. The equations provided reliable sediment delivery estimates for selected soils located throughout the United States. To use the sediment delivery equations, soil-related parameter values must he identified. Multiple regression analyses were performed to relate parameter values used in the equations …

Cultivators For Conservation Tillage, Robert Grisso, Paul J. Jasa, Elbert C. Dickey

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Cultivation, a proven weed control methods, should be used primarily to control weeds, rebuild ridges, or aerate poorly drained or crusted soils. Cultivating just to stir the soil usually dries the soil and can result in lower yields during drier cropping conditions. For example, cultivating during warm and windy conditions can result in ¼ to ¾ inches of soil moisture loss.

The main difference between a conservation tillage cultivator and a conventional cultivator is the ability to handle residue and penetrate the soil. By definition, conservation tillage should leave at least 30 percent of the soil surface covered with crop …

Definitions Of Tillage Systems For Corn, J. C. Siemens, Elbert C. Dickey, E. D. Threadgill

Department of Agricultural and Biological Systems Engineering: Faculty Publications

If "tillage" is defined as the mechanical manipulation of soil, it follows, then, that a "tillage system" would be the sequence of soil-manipulation operations performed in producing a crop. Today, however, such a definition is recognized as inadequate. We know, for instance, that the management of non-harvested plant tissue (i.e., residue) affects both crop production and soil erosion, and that field operations in which the soil is not tilled have a marked influence on soil condition.

Therefore, in this publication, a tillage system is the sequence of all operations involved in producing the crop, including soil manipulation, harvesting, chopping or …

Management Of Feedlot Runoff Control Systems, Elbert C. Dickey, Gerald R. Bodman

Department of Agricultural and Biological Systems Engineering: Faculty Publications

During recent years, most open feedlot operators have found it desirable and, in some cases, necessary to install runoff control facilities. Even though the primary purpose of feedlot runoff control systems is the prevention of water pollution, many producers have found that good management of these systems also offers limited economic benefits in the form of fertilizer nutrients and supplemental irrigation water. Well managed runoff control systems also reduce weeds, odors, insects and muddy areas at or near feedlot edges. The runoff control system that has proved most satisfactory for all areas of the country is one consisting of clean …

Kinetic Analysis Of Competing Intramolecular And Intermolecular Polymerization Reactions, Hossein Noureddini, Delmar C. Timm

Papers in Molecular Chemistry

ABSTRACT: Kinetic reaction theory was used to model a step-growth, thermoset polymerization of a monomer of even functionality/. Intermolecular additions were represented by second-order and intramolecular reactions were expressed by first-order rate expressions. All functional groups were assumed to react with equal reactivity. Independent variables are degree of polymerization i, extent of cross-linking j, and conversion p. The normalized rate constant for intramolecular reactions is c. The solution for the normalized population density distribution............ subj Formulae for the number-, mass-, and cross-link-average molecular weights were derived.

Internal Control, Integrated Framework: Executive Summary September 1992, Committee Of Sponsoring Organizations Of The Treadway Commission

Association Sections, Divisions, Boards, Teams

No abstract provided.

Internal Control, Integrated Framework: Framework, Revised Draft February 1992, Committee Of Sponsoring Organizations Of The Treadway Commission

Association Sections, Divisions, Boards, Teams

No abstract provided.

Monoclonal Antibodies Specific For Mercuric Ions, Dwane E. Wylie, Di Lu, Larry D. Carlson, Randy Carlson, K. Funda Babacan, Sheldon M. Schuster, Fred W. Wagner

Department of Biochemistry: Faculty Publications

Monoclonal antibodies (mAbs) that react with soluble mercuric ions have been produced by i 'ection of BALB/c mice with a hapten-carrier complex designed to maximize exposure of the metal to the immune system. Three hybridomas producing antibodies that reacted with bovine serum albumin (BSA)-glutathione-HgCI, but not with BSAglutathione, were isolated from the spleen of a mouse given multiple iqjections with glutathione-HgCl conjugated to keyhole limpet hemocyanin. Stable subclones were established from two of these antibodies, designated mAb 4A10 and mAb IF10. The binding of both antibodies to immobilized BSAglutathione- HgCl was inhibited by soluble HgCl₂, and dissociation constants …

Light Activation Of Maize Phosphoenolpyruvate Carboxylase Protein-Serine Kinase Activity Is Inhibited By Mesophyll And Bundle Sheath-Directed Photosynthesis Inhibitors, Jin-An Jiao, Raymond Chollet

Department of Biochemistry: Faculty Publications

C₄ phosphoenolpyruvate carboxylase (PEPC) is post-translationally regulated by reversible phosphorylation of a specific N-terminal seryl residue in response to light/dark transitions of the parent leaf tissue. The protein-serine kinase (PEPC-PK) that phosphorylates/activates this mesophyll-cytoplasm target enzyme is slowly, but strikingly, activated by high light and inactivated in darkness in vivo by a mechanism involving cytoplasmic protein synthesis/degradation as a primary component. In this report, evidence is presented indicating that the inhibition of Calvin cycle activity by a variety of mesophyll (3-(3,4-dichlorophenyl)-1,1-dimethylurea, isocil, methyl viologen) and bundle sheath (DL-glyceraldehyde)-directed photosynthesis inhibitors blocks the light activation of maize (Zea mays …

Systematic Relationships Within The Cyprinid Genus Rhinichthys, David Woodman

School of Biological Sciences: Faculty Publications

As presently understood the genus Rhinichthys consists of seven species: R. atratulus, R. bowersi, R. cataractae, R. deaconi, R. evennanni, R. falcatus, and R. osculus (Lee et al., 1980; Matthews et al., 1982; Miller, 1984; Goodfellow et al., 1984). The genus is mostly western in distribution but R. atratulus is restricted to the eastern portion of North America. Rhinichthys cataractae is the only other species found in eastern North America, but substantial populations also exist west of the Continental Divide. Rhinichthys falcatus is restricted to the Fraser and Columbia River system and R. osculus …

Local Polyploid Variation In The Native Prairie Grass Andropogon Gerardii, Kathleen H. Keeler

School of Biological Sciences: Faculty Publications

The microscale distribution of polyploid variants of the dominant grass big bluestem (Andropogon gerardii) in virgin tallgrass prairie was mapped using flow cytometry. The correlation between DNA content and polyploidy allows the use of flow cytometry for nondestructive determination of polyploidy in intact plants. At Konza Prairie, local plots contained from 0 to 100% hexaploid cytotypes but most showed fine-scale mixing of the polyploid variants. The relationship of cytotype frequency to moisture availability or burning history was nonsignificant

Characterization Of The TrnaTrp Genes Of Saccharomyces Cerevisiae, Audrey L. Atkin, R. W. Henry, K. L. Roy, J. B. Bell

School of Biological Sciences: Faculty Publications

The purpose of this work was to examine the tRNA^Trp-encoding genes (tRNA^Trp) of Saccharomyces cerevisiae to gain insight as to why tRNATrp amber suppressors, isolated by conventional genetic techniques, have not been reported. The results herein indicate that the haploid yeast genome contains six tRNA^Trp genes which map to five or six chromosomes. Not only do the six genes have identical coding sequences but their introns are also identical. Gene replacement experiments indicate that five copies of tRNA^Trp are sufficient for cell viability. Thus, mutation of one tRNA^Trp gene to a suppressor in …

The Costs Of Female Choice In A Lekking Bird, Robert M. Gibson, Gwendolyn C. Bachman

School of Biological Sciences: Faculty Publications

We investigated the costs of active female choice in sage grouse, Centrocercus urophasianus, a lekking species in which females make repeated, lengthy visits to leks to assess males before mating. Several potential costs were measured by monitoring changes in hens' ranging behavior, time budgets, and encounter rates with predators when they visited leks. Two costs were identified: hens moved further per day and encountered golden eagles, Aquila chrysaetos, more frequently when visiting leks. However, extra travel due to visiting leks increased predicted daily energetic expenditure by only about 1%, and the risk of predation by golden eagles over …

Plant Resistance To Insect Herbivores: A Field Test Of The Environmental Stress Hypothesis, Svata M. Louda, Sharon K. Collinge

Svata M. Louda Publications

We tested the hypothesis that environmental stresses decrease overall plant resistance to insect herbivory in the field and evaluated biochemical mechanisms proposed to explain insect response to stressed plants. To impose a stress treatment, we severed lateral roots and rhizomes of a native crucifer (bittercress, Cardamine cordifolia) and quantified plant and herbivore responses for treatment and control clones. Severing roots and rhizomes once, early in the growing season: (1) produced moderate, but detectable, changes in plant physiological traits, specifically greater transient leaf water deficits at midday (P < .05) and elevated nitrate-nitrogen concentrations (P < .05); (2) altered plant quality, by causing an increase in soluble carbohydrates (P < .003), isoleucine concentrations in leaves (P < .01), and possibly glucosinolate concentration (P < .10), but made no differences in most primary nutrient concentrations, including total nitrogen, total free amino nitrogen, total amino acids, proline, and leaf water content; and (3) led to increased herbivore by chewing and leaf-mining (P < .001), but not by sap-feeding, insect herbivores. Trends toward decreased plant stature and fruit reproduction were not significant after 1 mo. In addition to the significant effect of our treatment, we found extensive variation in the magnitude of response to stress and herbivory among replicates. We hypothesize that environmentally induced physiological variation among plants within a plant population commonly distributes insect herbivore disproportionately onto a subset of the individuals, and in so doing influences the demography, distribution, and evolution of that plant population.

Ultrasonic Measurements In Superconducting Upt3, Shireen Adenwalla, S.-W. Lin, Z. Zhao, J. B. Ketterson, M. Levy, Bimal K. Sarma

Shireen Adenwalla Papers

Ultrasonic measurements on the heavy fermion superconductors have proved a useful tool in elucidating the nature of the superconfucting state. Earlier measurements of sound attenuation in superconducting UPt3 showed power-law temperature dependences (rather than an exponential temperature dependence as expected for a BCS type superconductor), indivating the presence of nodes in the gap. Subsequent ultrasonic measurements have shown indications of phase transitions within the superconducting state. In particular, these ultrasonic velocity measurements show the presence of three superconducting phases in the mixed state. The size of the velocity jump can be related to the heat capacity jump. Further, using a …

Morphology Of The Synlophe And Genital Cone Of Parostertagia Heterospiculum (Trichostrongylidae) With Comments On The Subfamilial Placement Of The Genus, Eric P. Hoberg, J. Ralph Lichtenfels

Harold W. Manter Laboratory of Parasitology: Faculty Publications

The genus Parostertagia is referred to the Cooperiinae with reference to a suite of shared characters of the synlophe and genital cone postulated as derived homologies for the subfamily. The genus has traditionally been relegated to the Graphidiinae or Ostertagiinae, but unique structural attributes of the synlophe and genital cone indicate close affinities with the Cooperiinae. The synlophe of Parostertagia heterospiculum is characterized by a relatively low number of ridges in the cervical zone (16-20 at the excretory pore), a frontal axis of orientation, sequential increase in ridges posteriorly, lateral addition of ridges, minuscule lateral-most ridges and hypertrophy of specific …

Historical Ecology As A Research Program, Daniel R. Brooks, Deborah A. Mclennan

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Modern evolutionary biology is the descendant of two theories proposed by Darwin. First, all organisms are connected by common genealogy, and second, the form and function of organisms is closely tied to the environments in which they live. Of these two theories, the role of the first (phylogeny) in evolutionary explanations has been diminishing in some fields, most notably in ecology and ethology. However, the last ten years have witnessed the beginning of a reversal in this trend. With increasing frequency, ecologists (Wanntorp et aI., 1990; Maurer and Brooks, submitted), ethologists (Dobson, 1985; Huey and Bennett, 1987; Mclennan et aI., …

Full-Scale Crash Tests On A Luminaire Support 4-Bolt Slipbase Design, Brian G. Pfeifer, James C. Holloway, Ronald K. Faller, Edward R. Post, David L. Christensen

Department of Civil and Environmental Engineering: Faculty Publications

The breakaway luminaire support concept has existed for many years and has proven to be an effective safety device. The 4-bolt breakaway slipbase design was originally used in Utah and has been used successfully in 20 years of field implementation. The state transportation departments of Idaho, Montana, Nevada, Utah, and Wyoming requested that the 4-bolt slipbase system be evaluated for possible use on Federal-aid highway projects. Two full-scale vehicle crash tests were performed by the Midwest Roadside Safety Facility to evaluate the system. Both tests had a centerline impact location. Test USBLM-1 was conducted with a 1,800-lb vehicle traveling at …

1H, 15N, 13C, And 13Co Assignments Of Human Interleukin-4 Using Three-Dimensional Double- And Triple-Resonance Heteronuclear Magnetic Resonance Spectroscopy, Robert Powers, Daniel S. Garrett, Carl J. March, Eric A. Frieden, Angela M. Gronenborn, G. Marius Clore

Robert Powers Publications

The assignment of the ¹H, ¹⁵N, ¹³CO, and ¹³C resonances of recombinant human interleukin-4 (IL-4), a protein of 133 residues and molecular mass of 15.4 kDa, is presented based on a series of 11 three-dimensional (3D) double- and triple resonance heteronuclear NMR experiments. These studies employ uniformly labeled ¹⁵N- and ¹⁵N/¹³C-labeled IL-4 with an isotope incorporation of >95% for the protein expressed in yeast. Five independent sequential connectivity pathways via one-, two-, and three-bond heteronuclear J couplings are exploited to obtain unambiguous sequential assignments. Specifically, CO(i)-N(i+l),NH(i+l) correlations are observed in the HNCO …

Analysis Of The Backbone Dynamics Of The Ribonuclease H Domain Of The Human Immunodeficiency Virus Reverse Transcriptase Using 15N Relaxation Measurements, Robert Powers, G. Marius Clore, Stephen J. Stahl, Paul T. Wingfield, Angela Gronenborn

Robert Powers Publications

The backbone dynamics of the uniformly ¹⁵N-labeled ribonuclease H (RNase H) domain of human immunodeficiency virus (HIV- 1) reverse transcriptase have been investigated using two-dimensional inverse-detected heteronuclear ¹⁵N-^lH NMR spectroscopy. ¹⁵N T₁, T₂, and nuclear Overhauser enhancement (NOE) data were obtained for 107 out of a total of 134 backbone amide groups. The overall rotational correlation time (T_R) for the protein at 26˚ is 10.4 ns. The backbone N-H vectors for all the measurableresidues exhibit very fast motions on a time scale of <20 ps. The ¹⁵N relaxation data for …

Determination Of The Secondary Structure And Folding Topology Of Human Interleukin-4 Using Three-Dimensional Heteronuclear Magnetic Resonance Spectroscopy, Daniel S. Garrett, Robert Powers, Carl J. March, Eric A. Frieden, G. Marius Clore, Angela M. Gronenborn

Robert Powers Publications

The secondary structure of human recombinant interleukin-4 (IL-4) has been investigated by three-dimensional (3D) ¹⁵N- and ¹³C-edited nuclear Overhauser (NOE) spectroscopy on the basis of the ¹H, ¹⁵N, and ¹³C assignments presented in the preceding paper [Powers, R., Garrett, D. S., March, C. J., Frieden, E. A,, Gronenborn, A. M., & Clore, G. M. (1992) Biochemistry (preceding paper in this issue)]. Based on the NOE data involving the NH, C^αH, and C^βH protons, as well as ³J_HNα coupling constant, amide exchange, and ¹³C^α and ¹³C^{β …}