Physical Sciences and Mathematics Commons^™

Spatial Analysis Of Grasshopper Density As Influenced By Anthropogenic Habitat Changes, Bahman Shafii, William J. Price, Dennis J. Fielding, Merlyn A. Brusven

Conference on Applied Statistics in Agriculture

The rangeland environment in southern Idaho has been heavily impacted by human activities. Invasion by exotic plant species, frequent fires, grazing pressure, and other ecological disturbances have greatly affected the structure and dynamics of grasshopper populations. Quantification of spatial patterns of grasshopper density and species composition is important in order to determine their influence on grassland ecosystems, as well as evaluating managerial decisions concerning vegetation manipulations, grazing practices, and spraying programs. A spatial statistical approach to modeling the heterogeneity of grasshopper populations is presented, and the impact of vegetation and grazing treatments on grasshopper density is investigated. Empirical applications are …

A Classification Of Unreplicated Factorial Experiments For Use With The Analysis Of Deterministic Simulation Models, J L. Willers, B. T. Vinyard

Conference on Applied Statistics in Agriculture

Deterministic simulation models are important in agricultural applications and their use is becoming increasingly common. Therefore, statistical procedures that interpret the output and evaluate the performance of deterministic models are necessary. The fact that deterministic computer simulation experiments cannot be replicated provides opportunities for using several procedures applicable to unreplicated factorial experiments. We discuss a classification scheme that selects the correct technique for most deterministic simulation experiments. The value of these techniques is their capability to estimate the experimental error variance for unreplicated computer experiments. Using these estimates of error, model developers and practitioners can more thoroughly analyze their deterministic …

Estimation Of And Adjustment For Residual Effects In Dairy Feeding Experiments Utilizing Changeover Designs, Ramon C. Littell, Charles J. Wilcox, H. H. Van Horn, A. P. Tomlinson

Conference on Applied Statistics in Agriculture

A procedure is presented which demonstrates estimation of and adjustment for residual effects in changeover designs. The method utilizes all data collected in an experiment by including treatments imposed on animals prior to initiation of data collection. Estimation is achieved via general linear models. An example is given of a nutrition experiment conducted with dairy cattle. Such analyses should increase efficacy of changeover designs and reduce concern by researchers about biased estimates of direct effects which could result from residual effects. Methods from popular computer programs for estimating direct effect treatment means are compared. Practical problems encountered in computing standard …

Issues In Analysis Of A Long-Term Integrated Pest Management Field Study, J. R. Alldredge, F. L. Young

Conference on Applied Statistics in Agriculture

A team of 14 scientists conducted a 6-year, 16-ha, integrated pest management field study in the dryland wheat production area of the Pacific Northwest. Objectives were to develop a profitable crop production system that controls weeds effectively and reduces soil erosion. Farm-size machinery was used to till, plant, and harvest crops grown in either a continuous wheat (Triticum aestivum L.) sequence or a 3-year crop rotation of winter wheat-spring barley (Hordeum vulgare L.) -spring pea (Pisum sativum L.) in conservation and conventional tillage systems. Main plot factor levels were two tillage systems and three …

Bayesian Inference On Variance Components In Generalized Linear Mixed Models: An Evaluation Of Different Methods, Robert J. Tempelman

Conference on Applied Statistics in Agriculture

Generalized linear mixed models are now popular in the animal breeding and biostatistics literature as these models allow inference on fixed and random effects for the exponential family of data distributions. In animal breeding, particular attention is directed towards variances of the random effects. We investigate three methods for marginal inference on variance components in binary data, including (1) the conventional expectation-maximization (EM) type algorithm, (2) Laplace's method, and (3) "exact" Gibbs sampling methods. A simulation study involving probit animal models was used to compare the modal estimates computed under the three methods. It was found that EM estimates were …

Variance As A Factor Effect In Interdisciplinary Studies Of Agricultural Systems, Cathryn S. Miller, Dawn M. Vanleeuwen, Jill Schroeder, Mike Kenney

Conference on Applied Statistics in Agriculture

Studies of interrelationships among factors typically focus on factor effects related to the mean response. In some instances, response variances, as well as, or even rather than, response means, may be affected by the factors under consideration. In this paper, generalizations of Levene's test and the Jackknife test to two-factor experimental designs are studied via simulation studies to assess their ability to identify differences in the variance as an interaction effect or as a factor main effect. These tests are then applied to a particular example where relationships between chile plants and two prominent pests of chile plants -nematodes and …

Predicting The Date Of First Catch Of The Corn Earworm, Helicoverpa Zea, In Central U.S., J. H. Matis, S. Yang, N. Castiaux, J. K. Westbrook, K. R. Beerwinkle, J. D. Lopez Jr.

Conference on Applied Statistics in Agriculture

This paper develops predictive (or correlative) models for the date of first catch of the com earworm, Helicoverpa zea, as a basis for identifying biotic and abiotic factors that influence dispersal and migration. Data described in Goodenough et al. (1988, J. Econ. Entomol.) on the catch of H. zea gathered at over 150 sites predominantly in the central U.S. from 1983 to 1986 are analyzed. The dependent variables, Y₁ and Y₂, are date of first meaningful catch and date when cumulative catch exceeds 5, respectively; the independent variables are latitude, longitude and elevation of the site. …

Sampling Schemes To Detect Very Low Concentrations, Terry C. Nelsen

Conference on Applied Statistics in Agriculture

Many mycotoxins and certain drug residues can be important at very low concentrations in feeds and foods. Government regulatory agencies establish maximum acceptance concentrations (Action Levels) to avoid proven effects of known toxins and provide Advisory Levels where effects are not yet well established. The Action Levels for the aflatoxins range from 5 to 300 ppb (ng/g) depending on the particular toxin and the intended use of the feed or food. Other naturally occurring mycotoxins, such as DON, zearalenones, and fumonisons, have advisory levels in the range of 1 to 5 ppm (j.A-g/g) . Chemotherapeutic agents in feeds must be …

Sampling Segments In An Area Frame With A Distance Threshold, M. Fuentes, F. J. Gallego

Conference on Applied Statistics in Agriculture

A simple random sample in an area frame usually gives a number of pairs of elements that are close to each other. These elements give redundant information since there is usually a high spatial autocorrelation at short distances. The efficiency of sampling is generally improved if we impose that the distance between two elements of the sample cannot be less than a certain threshold. However applying this restriction can introduce a significant perturbation of the sampling probability. Elements near the borders of the region are more likely to be selected. In the case of aligned sampling by repetition of a …

Covariance Analysis With A Covariate Interaction: An Example Of A Simple Linear Regression Comparison Technique, D. E. Palmquist, C. A. Stockwell

Conference on Applied Statistics in Agriculture

Many real data sets that would normally lend themselves to being analyzed by an analysis of covariance, have a covariate interaction present with one or more of the factors in the experiment. Because this violates the assumption of same-slope covariate effect across all treatments, an analysis of covariance should not be performed. The course normally taken when there is such an interaction is to derive regression equations for the dependent variable as a function of the covariate, at each level of the factor(s) being tested. A general linear model F-test can then be used to test whether there are any …

A Review Of Analysis Of Experimental Data, Roger Mead

Conference on Applied Statistics in Agriculture

Initial Assumptions, We assume that it is standard practice to base an initial analysis of experimental data on a linear model including terms for blocks, treatments and covariates. This produces a summary analysis of variance, indicating the major components of variation relative to the fitted model, and tables of means (one- or two-way) as indicated from the analysis of variances, with appropriate standard errors.

Editor's Preface, Table Of Contents, And List Of Attendees, James R. Schwenke

Conference on Applied Statistics in Agriculture

These proceedings contain papers presented in the seventh annual Kansas State University Conference on Applied Statistics in Agriculture, held in Manhattan, Kansas, April 23 through 25, 1995.

The Annual Meeting Of The Iowa Academy Of Science April 21-22, 1995 [Program, 107th Meeting], Iowa Academy Of Science

Iowa Academy of Science Documents

Contents:

Program Summary --- 5
General Session Speakers --- 8
Awards --- 11
Symposia Programs --- 12
Poster Session14
Map --- Centerfold
Section Programs/Special Sessions --- 17
Agricultural Sciences --- 17
Anthropology --- 17
Botany --- 19
Cellular & Molecular Biology --- 20
Chemistry, Inorganic --- 21
Chemistry, Organic --- 23
Conservation --- 24
Engineering --- 25
Geology --- 27
Physics --- 29
Physiology/Zoology --- 29
Psychology Linguistics --- 30
Science Teaching --- 31
Annual Meeting Committee --- 33
Local Arrangements Committee --- 33
IAS Officers & Directors --- 34
Future Meetings --- 34

Iowa Academy Of Science President's Banquet [107th Session], Iowa Academy Of Science

Iowa Academy of Science Documents

Program:

Introductions
Awards:
Distinguished Fellow: George Burnet
Distinguished Iowa Science Teaching: Gary E. Downs
Distinguished Service: Harold McNabb
President's Address - Daryl Smith
Response - Ross Iverson, President-Elect
General Sessions II - Dr. Thomas Starzl, "Why Allografts are Accepted: The Study in Applied Biology"

Program Abstracts, 107th Session, Iowa Academy Of Science, April 21-22, 1995, Iowa Academy Of Science

Iowa Academy of Science Documents

Presentation abstracts from the annual meeting of the Iowa Academy of Science

Partial-Wave Representations Of Laser Beams For Use In Light-Scattering Calculations, Gérard Gouesbet, James A. Lock, Gérard Gréhan

Physics Faculty Publications

In the framework of generalized Lorenz-Mie theory, laser beams are described by sets of beam-shape coefficients. The modified localized approximation to evaluate these coefficients for a focused Gaussian beam is presented. A new description of Gaussian beams, called standard beams, is introduced. A comparison is made between the values of the beam-shape coefficients in the framework of the localized approximation and the beam-shape coefficients of standard beams. This comparison leads to new insights concerning the electromagnetic description of laser beams. The relevance of our discussion is enhanced by a demonstration that the localized approximation provides a very satisfactory description of …

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Van Hove Singularity Induced L11 Ordering In Cupt, J. F. Clark, F. J. Pinski, Duane D. Johnson, P. A. Sterne, J. B. Staunton, B. Ginatempo

Duane D. Johnson

We describe an ordering mechanism that arises due to coupling between electronic states at van Hove singularities. This novel mechanism, which naturally leads to ordered structures with small unit cells, couples states near the Fermi energy which are localized at high-symmetry points in k space, in contrast to the conventional mechanism which relies on large parallel sheets of Fermi surface. Using first-principles calculations of the electronic structure of ordered and disordered alloys, we show that this mechanism drives the unusual short- and long-range order found in fcc CuPt.

A Comparison Of Attitudes Held By Wildlife Damage Managers And Animal Rights Activists, James B. Armstrong, Melissa E. Hutchins

Great Plains Wildlife Damage Control Workshop Proceedings

We designed an instrument to measure attitudes about a variety of animal use issues, collect information on animal-related activities, and determine demographic characteristics of the sample. We administered the instrument to 151 Animal Rights Information and Education Service (ARIES) and 150 National Animal Damage Control Association (N ADC A) members. Based on analysis of the data, we concluded that these 2 groups differ greatly on their attitudes about human use of animals. In addition, they differ greatly in background and types of activities in which they participate. Thus, attempts to bring these groups together for discussion must start with the …

Microstructure Of The Cr Underlayer And Its Effect On Sm-Co//Cr Thin Films, Yi Liu, B. W. Robertson, Z.S. Shan, Sy_Hwang Liou, David J. Sellmyer

Sy-Hwang Liou Publications

Sm-Co film is a potential candidate for the future high density recording media of 10 Gb/in² which requires bit sizes of the order of 300 nm and grain sizes of about 10 nm. This article investigates the microstructure of the Cr underlayer in Sm-Co thin films and its effect on Sm-Co thin films prepared by the dc magnetron sputtering technique. The grain size of the Cr underlayer is found to be about 25 nm. Grains with small angle misorientation usually form local agglomerates. Studies by transmission electron microscopy (TEM) bright field images at different defocus settings and by high …

Conduction-Electron Screening In The Bulk And At Low-Index Surfaces Of Ta Metal, D. Mark Riffe, W. Hale, B. Kim, J. L. Erskine

All Physics Faculty Publications

High-resolution core-level photoemission spectra from Ta(100) have been measured. The well-resolved peak from the first atomic layer allows a separate assessment of bulk and surface-layer screening responses: singularity indices α_B=0.10±0.01 and α₁₀₀=0.205±0.025, respectively, are obtained. The measured surface-atom lifetime broadening of 70±20 meV (compared to 37±5 meV in the bulk) is consistent with published Auger–photoemission coincidence measurements. The result for the bulk singularity index has been applied in the analysis of previous data in order to extract the screening response in the first atomic layer of Ta(111) (α₁₁₁=0.16±0.01) and Ta(110) (α₁₁₀=0.150±0.015). The …

Scaling And The Fractal Geometry Of Two-Dimensional Quantum Gravity, Simon Catterall, G. Thorleifsson, Mark Bowick, V. John

Physics - All Scholarship

We examine the scaling of geodesic correlation functions in two-dimensional gravity and in spin systems coupled to gravity. The numerical data support the scaling hypothesis and indicate that the quantum geometry develops a non-perturbative length scale. The existence of this length scale allows us to extract a Hausdorff dimension. In the case of pure gravity we find d_H approx. 3.8, in support of recent theoretical calculations that d_H = 4. We also discuss the back-reaction of matter on the geometry.

Target Dependence Of Binary Encounter Electron Peak Anomalies In Collisions Of Partially Stripped Heavy Ions With Molecular Hydrogen And Noble Gases, W. Wolff, J. Wang, H. E. Wolft, J. L. Shinpaugh, Ronald E. Olson, D. H. Jakubassa-Amundsen, S. Lencinas, U. Bechthold, R. Herrmann, H. Schmidt-Bocking

Physics Faculty Research & Creative Works

A systematic search was performed for the manifestation of quantum interference effects in the shape and angular distribution of the binary-encounter electron peak in collisions of partially stripped, or structured, heavy ions with noble gases and molecular hydrogen. The ionic species investigated were Cu5+,19+, I7+,23+, Au11+,29+ and U13+, all at the same nominal velocity equivalent to 0.6 MeV amu-1. Experimental double-differential cross sections for secondary electron emission in the binary encounter energy region are compared with a simple model based on the elastic scattering of quasi-free target electrons in the projectile field as well as with results of impulse approximation …

Dynamics Of Wildlife Damage Management, Bobby R. Acord

Great Plains Wildlife Damage Control Workshop Proceedings

Wildlife damage management is a dynamic profession. Our focus has shifted from dealing with primarily agricultural interests. In addition to agricultural issues, we now deal with endangered species protection, human health and safety, and wildlife damage management issues in the urban environment. The dynamics of wildlife damage management are influenced by the changing needs of society, professionalism among our ranks, and the political process. Professionalism and meeting the needs of the public continue to be the most important part of the dynamics of wildlife damage management.

Effective Repellency Concentration Of Bird Shield Repellent(Tm) With Methyl Anthranilate To Exclude Ducks And Geese From Water Impoundments, Leonard R. Askham

Great Plains Wildlife Damage Control Workshop Proceedings

Laboratory studies were conducted to establish the effective repellency concentration (EC_R) of Bird Shield Repellent(^TM) on mallard ducks (Anas platyrhynchos) and domestic geese for fresh water impoundments. Six concentrations of the repellent compound, ranging from 90 ppm to 2,890 ppm, were placed in small ponds in 2 aviaries and bird behavior monitored for 7 days. Concentrations <360 ppm did not limit either of the test species' activities (drinking or bathing) in the impoundments. Concentration >725 ppm precluded most activity after an initial exposure. Dissolved oxygen tended to decrease after an initial rise and pH increased slightly. Impoundments became discolored with higher concentrations of the repellents' methyl anthranilate precipitates in 24 hr.

Effects Of Mule Deer Grazing On Alfalfa Seed Production, Dennis D. Austin, Philip J. Urness

Great Plains Wildlife Damage Control Workshop Proceedings

Evaluation of crop loss caused by mule deer (Odocoileus hemionus) grazing on alfalfa grown for seed harvest was studied in northern Utah. Results indicated (1) wire baskets used to protect non-grazed plots did not affect alfalfa production, and (2) alfalfa seed crop loss was directly correlated with alfalfa hay crop loss. Consequently, methods used to evaluate crop loss to alfalfa hay may be applied to alfalfa seed.

Resolving Human-Large Felid Conflicts Associated With Protected Areas In India, N.P.S. Chauhan, V.B. Sawarkar, H.S. Pabla

Great Plains Wildlife Damage Control Workshop Proceedings

In India, the past 2 decades of improved wildlife management practices along with rigid legal provisions have resulted in increased populations of the endangered carnivores: tiger (Panthera tigris), lion (Panthera leo), and leopard (Panthera pardus) in protected areas (PAs). Over this time period, human and livestock populations in and around PAs have also increased substantially. Intense human use and commensurate cattle grazing activity in associated forests have invariably lead to confrontation with these carnivores. Incidences of human- and cattle-killing by tiger, lion, and leopard have increased in and around PAs. Ongoing conflicts occur with …

Plastic Visual Barriers Were Ineffective At Reducing Recolonization Rates Of Prairie Dogs, Scott E. Hygnstrom

Great Plains Wildlife Damage Control Workshop Proceedings

Two plastic visual barriers were ineffective in controlling expansion of 7 active black-tailed prairie dog (Cynomys ludovicianus) colonies and recolonization of 7 toxicant-treated sections of colonies. Barriers constructed with Sno-Strap, a 15.2- cm wide band of high-tensile polyethylene plastic, were destroyed by wind action within 3 weeks. Barriers constructed with Tensar® snowfence cost $2.10/m and retained their structural integrity for 3 years with occasional maintenance. Recommendations are provided to increase effectiveness of visual barriers.

Effectiveness Of Squirrel Fencing For Protecting Pecan Groves, Mcalister D. Maxwell, J. Grant Huggins, Clark E. Adams

Great Plains Wildlife Damage Control Workshop Proceedings

During 1994, we tested the hypothesis that an energized, high-tensile wire fence prevents fox squirrels (Sciurus niger) from crossing into a pecan (Carya illinoensis) grove. When the fence was energized, we recorded fewer (P = 0.03) trips across the fence by squirrels (n - 19) and fewer (P < 0.001) telemetry fix-points in the pecan grove. Effective squirrel fencing may offer wildlife managers an alternative method of damage prevention. Ecological ramifications to target and non-target species are discussed.

Immunocontraception And Possible Application In Wildlife Damage Management, Lowell A. Miller

Great Plains Wildlife Damage Control Workshop Proceedings

lmmunocontraception technology appears to have viable application in wildlife damage management. However, administration of these vaccines is presently performed by syringe injection or remote delivery by darts or bio-bullets. In order for immunocontraception to be successful for broad scale application to free-roaming animals, the vaccine must be delivered in an oral form. Recent advances in molecular biology, immunology, and pathology of mucosal infection gives us tools to develop effective oral vaccines. Oral immunocontraceptive vaccine encapsulated in adhesive liposomes or non-virulent live vectors holds promise as a practical approach for immunocontraception of free-roaming wildlife. Issues of safety, species specificity, regulatory constraints, …