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Optimization Of Ranch Management Alternatives In Utah, Scott G. Evans

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this study was to determine the optimum combination of various cattle production, range forage, and crop harvesting alternatives available to ranch owners and managers in Utah. While many promising alternatives are available, determining which alternatives to implement is difficult because the total ranch operation must be considered.

Linear programming (LP) is a tool available to ranch managers which allows the profit maximizing combination of improvements to be easily determined. LP allows ranchers to examine the entire ranch operation and to reduce the amount of risk and uncertainty involved in the decision making process.

The typical Utah ranch …

Dynamic Multi-Species Animal Habitat Modeling With Forest Succession Models, Stephen A. Compton

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This research determines and demonstrates the ability to simulate dynamic multi-species animal habitat suitability with forest succession models. A literature review of dynamic animal habitat models is presented. The structure of an existing forest simulation model (MASS10) was modified from a basal area-based model to a volume-based model (DYNAM10). The forest model was calibrated using data from permanent-plot growth and vegetation samples collected by USDA Forest Service Forest Survey procedures. The theoretical growth parameters used to simulate stand development were validated. Predictions of DBH and height growth, as well as stand-level behavior, were verified. A subroutine, VEGDYN, was added to …

Soil Heterogeneity And Its Exploitation By Plants, Robert B. Jackson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In this dissertation I first examine the ability of individual plants in the field to garner localized soil nutrients. I then measure actual soil variability around perennial plants and use various statistics to quantify the scale and degree of that variability.

Soil patches on opposite sides of Pseudoroegneria spicata tussocks were treated with distilled water or a nutrient solution containing N, P, or K in three field experiments. When P was augmented in the enriched soil patches, rates of P uptake increased significantly for roots from enriched patches compared with roots in control patches. Rates of ammonium and potassium uptake …

A Maple Package For The Variational Calculus, Cinnamon Hillyard

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The HELMHOLTZ package, written in Maple V, is a collection of commands to support research in the variational calculus. These commands include the standard operators on differential forms, Euler-Lagrange operators, homotopy operators, Lie bracket, Lie derivatives, and the prolongation of a vector field. We give a brief introduction to the variational calculus. We describe each of the commands in the HELMHOLTZ package completely along with numerous examples of each. Applications of the package include verification of symmetry groups for differential equations, solving the inverse problem of the calculus of variations, computing generalized symmetries, and finding variational integrating factors. A complete …

A Comparison Of Two Linear Nonparametric Regression Techniques, Sylvain Sardy

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis presented a useful tool in regression. Nonparametric linear regression techniques were described in the general context of regression. A comparison of two of these techniques, kernel regression and iterative regression, showed various aspects of nonparametric linear regressors.

Inverse Problem In Porous Medium Using Homogenization, Helen Alkes

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The problem under consideration is that of obtaining a representation of the permeability of a porous medium which is heterogeneous and anisotropic from limited information. To solve this inverse problem we propose the use of two different pieces that work together. A simulated annealing algorithm is presented and coupled with an homogenization technique; together these solve the problem which was posed. Further, numerical simulation results are presented illustrating the use of the simulated annealing algorithm as well as a coupling with the homoginization technique. This study illustrates that the performance of the annealing algorithm is enhanced with usage of homogenization.

Disconjugacy And Oscillation Theory Of Linear Differential And Difference Equations, Yuhua Xu

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This dissertation is both a literature survey and a presentation of new and independent results.

The survey gives an overview of disconjugacy and oscillation theory for linear differential and difference equations with an emphasis on comparing the theory of difference equations to the theory of differential equations. Second order scalar equations, higher order scalar equations, matrix equations (systems) and Hamiltonian systems are discussed. A chapter on three-term recurrences of systems is also included. Both similarities and differences between differential and difference equations are described.

The new and independent results are for Hamiltonian systems of difference equations. Those results include the …

Hopf Bifurcation In A Parabolic Free Boundary Problem, Yoon-Mee Lee

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

We deal with a free boundary problem for a nonlinear parabolic equation, which includes a parameter in the free boundary condition. This type of system has been used in models of ecological systems, in chemical reactor theory and other kinds of propagation phenomena involving reactions and diffusion.

The main purpose of this dissertation is to show the global existence, uniqueness of solutions and that a Hopf bifurcation occurs at a critical value of the parameter r. The existence and uniqueness of the solution for this problem are shown by finding an equivalent regular free boundary problem to which existence …

Mobilization Of Iron Enhances The Iron-Dependent Biochemical Reactivity Of Asbestos In Vitro And Contributes To The Cytotoxicity Of Asbestos In Cultured Cells, Loren Glen Lund

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Asbestos related research began approximately 60 years ago, yet, the mechanism(s) by which asbestos exerts its biological effects is not well understood. The hypothesis upon which this dissertation is based is that mobilization of iron from asbestos enhances the iron-dependent biochemical reactivity of asbestos in vitro and contributes to asbestos-dependent cytotoxicity. The specific aims for this hypothesis were, 1) to determine whether iron was responsible for the biochemical reactivity of asbestos in vitro and asbestos-induced cytotoxicity in cultured cells, and 2) to determine whether mobilization of iron from asbestos enhanced the reactions catalyzed by asbestos in vitro and contributes to …

New Syntheses Of Diaryl Ethers, Tyrosinols, B-Hydroxytyrosinols, L,L-Isodityrosinol And L,L-Isodityrosine-Derived Agents Via The Diels-Alder Reaction, Xianqi Feng

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Syntheses of diaryl ethers were approached by use of a Diels-Alder reaction employing a new type of diene attached with an aryloxy group. Thus, 2-methyl-3-phenoxybutadiene (90b ), 2- methoxy-3-phenoxybutadiene (92b) and (4S)-3-(t- butyloxycarbony1)-2 ,2-dimethyl-4-( 4-(3-methoxy-1,3 -butadienyl-2- oxy )phenylmethyl]oxazolidine (93b) were synthesized in ~65% yields by methylenation of the carbonyl function in the corresponding 2- substituted acrylate aryl ester using Tebbe's reagent. The 1,3- bis[(trimethylsilyl)oxy ]-2-phenoxybutadiene (105) was made from 1-phenoxy-2-propanone (101) by a sequence of formylation and enolsilylation. Methyl propiolate (107) and dimethyl acetylenedicarboxylate (113) were heated at reflux with diene 9 0 b and 92b in toluene to provide …

Factors Affecting Seeds In A Sagebrush-Steppe Ecosystem And Implications For The Dispersion Of An Annual Plant Species, Cheatgrass (Bromus Tectorum L.), Michael Ira Kelrick

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

I investigated how shrub-induced spatial heterogeneity influenced and was manifested by a representative ground-story plant species at a sagebrush-steppe site in southwestern Wyoming. The dispersion of cheatgrass (Bromus tectorum) reflected differences between undershrub (higher plant densities) and interspace (between shrubs, supporting lower densities) microenvironments, hence the population ecology of this annual species served as a biological probe of shrub-associated patch structure in this community. Since cheatgrass is an annual, factors affecting the seed portion of its life cycle were of special interest. First, attributes of the above- and below-ground seed pool were characterized. The environment-wide seed depositional pattern …

Creating Ethnicity In The Hydraulic Village Of The Mormon West, Charles M. Hatch

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study has looked behind the mask of nineteenth-century theocracy to see Mormons in the Great Basin creating a democratic society of regionally concentrated kin groups where obligations and rewards for individuals were increasingly determined by age and life cycle position. As generations of young adults acted together in self-interest dispersing their villages on receding frontiers, they forged a balance between competition and cooperation which merged the immediate need of individuals to establish and support families with the collective memory of their Mormon past. In so doing, they created an identity for themselves which was unique in the arid West. …

Economic Strategies For White-Tailed Deer And Livestock Production On Central And South Texas Ranches, Will E. Cohen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Recently, hunting and associated recreation have become an important business for Texas landowners. Most ranchers want to realize maximum net return from their investments. This study's objectives were to develop white-tailed deer (Odocoileus virginianus) and livestock enterprise budgets and to determine optimal economic combinations and levels of deer and livestock enterprises to maximize net returns. Questionnaires were mailed to landowners in the Edwards Plateau and South Texas Plains who purchased shooting preserve licenses in 1985. Five hundred and twenty-four ranchers responded (23.4%). Respondents were segregated by enterprises (deer, cattle, sheep, and Angora and Spanish goats) and a 5% …

A Simulation Of The Economic Effects Of Alternative Soil Types And Nitrogen Sources On Nitrate Leaching On Irrigated Agriculture In Utah, Gilbert D. Miller

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The economic impact of reducing the amount of nitrate leached out of the root zone under irrigation in the arid West was examined. A general introduction into the nature of the problem and a review of the literature was provided in chapter I. In chapter ll the economic incentives of irrigation management were evaluated under the assumptions of both profit-maximizing and utility-maximizing (in reducing cost and effort expended in irrigation) decision-making criteria. The results indicate that there is a coincidence of interests of the farmer and the environment. Both behaviors result in less nitrate leaching than less profitable or less …

Origins Of Low-Angle Normal Faults Along The West Side Of The Bear River Range In Northern Utah, Jon E. Brummer

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This paper presents new interpretations of two normal-slip, low-angle faults near Smithfield and Richmond, Utah. The faults have previously been interpreted as landslides, gravity slides, slide blocks, and depositional contacts. Recent work in the Basin and Range province allows new interpretations concerning the origins of the low­-angle faults.

Working hypotheses used to interpret origins of the faults are classified as folded thrust fault, rotated high-angle normal fault, gravity slide, listric normal fault, and low-angle normal fault. Among these general categories are several subhypotheses. The evaluation of each hypothesis includes a description of the geologic requirements of the hypothesis, a comparison …

Ethical Beliefs And Practices: Do Psychologists Differ From Other Health-Care Professionals, Gary Percival

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Ethical codes and principles, and laws govern the behavior of health-care professionals. Yet, the impact that ethical codes and laws have on the actual moral behaviors of health-care professionals is relatively unknown. A survey on the ethical beliefs and practices of health-care professionals was sent to the United States membership of the Association for Applied Psychophysiology and Biofeedback. AAPB's heterogeneous membership offers a unique opportunity to compare the ethical beliefs and behaviors of professionals across various health-care professions, educational levels, licensure and certification statuses, age, years in practice, and gender. The survey examined the respondents' ethical beliefs and practices in …

Estimation Of Crop Evapotranspiration By Means Of The Penman-Monteith Equation, Paul J. Vanderkimpen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study evaluated the potential of using simple, semi-empirical resistance models for the direct estimation of crop evapotranspiration as an alternative to the traditional approach involving a reference equation and a crop coefficient. It consisted of three major parts.

The first part originally aimed at the development of simple expressions for the aerodynamic and surface resistance terms in the Penman-Monteith equation. This goal could not be achieved because of two reasons: First, the determination of aerodynamic resistance was rendered impossible because of problems with the measurements, and, secondly, the values of surface resistance, back-calculated from the Penman-Monteith equation, turned out …

Mathematical Programming Applications In Agroforestry Planning, Laurence H. Reeves

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Agroforestry as a sustainable production system has been recognized as a land use system with the potential to slow encroachment of agriculture onto forested lands in developing countries. However, the acceptance of nontraditional agroforestry systems has been hampered in some areas due to the risk-averse nature of rural agriculturalists. By explicitly recognizing risk in agroforestry planning, a wider acceptance of agroforestry is possible. This thesis consists of a collection of three papers that explore the potential of modern stock portfolio theory to reduce financial risk in agroforestry planning.

The first paper presents a theoretical framework that incorporates modern stock portfolio …

Is Rainbow Trout Condition Influenced By Invertebrate-Drift Density?, Randall B. Filbert

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Users of the Instream Flow Incremental Methodology CTFIM) commonly assume that there is a positive linear relationship between available habitat (WUA) and stream fish biomass. However, several studies have shown a lack cf correlation between WUA and biomass. Such poor relationships may occur if other factors limit fish abundance. Food availability is a potentially important factor limiting abundance of stream fishes and can affect blomass by influencing fish condition (individual weight). I collected rainbow trout (Oncorhynchus mykiss) exposed to different levels of invertebrate-drift density to determine if condition was greater where food was more abundant. I also examined …

Linear Operators Strongly Preserving Polynomial Equations Over Antinegative Semirings, Sang-Gu Lee

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

We characterized the group of linear operators that strongly preserve r-potent matrices over the binary Boolean semiring, nonbinary Boolean semirings, and zero-divisor free antinegative semirings. We extended these results to show that linear operators that strongly preserve r-potent matrices are equivalent to those linear operators that strongly preserve the matrix polynomial equation p(X) = X. where p(X) = X^r₁ + X^r₂ + ... + X^r_t and r₁>r₂>...>r_t≥2.

In addition, we characterized the group of linear operators that strongly preserve r-cyclic matrices over the same semirings. We …

A Comparison Of Estimation Procedures For The Beta Distribution, Huey Yan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The beta distribution may be used as a stochastic model for continuous proportions in many situations in applied statistics. This thesis was concerned with estimation of the parameters of the beta distribution in three different situations.

Three different estimation procedures-the method of moments, maximum likelihood, and a hybrid of these two methods, which we call the one-step improvement-were compared by computer simulation, for beta data and beta data contaminated by zeros and ones. We also evaluated maximum likelihood estimation in the context of censored data, and Newton's method as a numerical procedure for solving the likelihood equations …

Instructional Logistics And Chunque-Based Learning Systems, Ian A. Mcarthur

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Existing instructional design and curriculum design strategy components were synthesized to provide a comprehensive set of design models for the development of learning systems. The term instructional logistics was coined to define the management of student progress through a series of customized learning experiences. Strategies were developed for the design of student-centered learning systems by partitioning a curriculum into meaningful and manageable pieces (called chunques) and by manipulating those pieces to create personalized and individualized paths through a series of self-contained learning experiences. Strategies were developed to organize a collection of chunques into a path based on initial simplified mental …

An Ecological Test Of The Tragedy Of The Commons On Communal Rangeland In The Moroccan Western High Atlas, Lloyd Mendes

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

I empirically tested an hypothesis derived from a popularized version of Garrett Hardin's "Tragedy of the Commons" paradigm. Some range-development authors predict overgrazing and ecological abuse on all traditional communal rangelands. I estimated forage production, consumption, and season of use on one traditional agdal or intertribal common in the Moroccan Western High Atlas Mountains. Results from 1984-85 do not support the overgrazing predicted by "tragedy" proponents. I argue that the lack of overgrazing is not coincidental but is due to the traditional communal mechanism of controlling season of use.

Hydrogen Uptake Genes And Nitrogen Fixation Efficiency Of Rhizobium Species In Symbiosis With Alfalfa, Chickpea And Pigeonpea, G. Mustafa Sajid

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The plasmids pDN211 and pDNll, isolated from the gene bank of the Rhizobium japonicum strain I-110, have been reported to complement two different Nif⁺ Hup^· (nitrogen fixation positive and hydrogen uptake negative) mutants. A 5.9-kb Hindiii DNA fragment of the cosmid pHU52, isolated from the gene bank of R. japonicum strain 122DES, has been reported to code for the two polypeptide subunits of uptake hydrogenase. To determine homology between the structural genes of uptake hydrogenase of the two strains, a Southern blot of the Hindiii restriction fragments of the plasmids pDN211 and pDN11 was hybridized to the 5.9-kb …

Extension Of The Metal Light Pipe Infrared Spectroscopy Technique: Applications To Surface Adsorption And High Tc Superconductors, Torsten Will

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The development of an infrared instrument for the study of surface adsorption and high T_c superconductors is presented and its applicability is discussed. The use of and theoretical background for the metal light pipe multiple-reflection technique are discussed in comparison to other infrared devices. Measurements are carried out to determine its limitations with powdered substrates as well as its sensitivity limitation for thin films. The results of the two test measurements, adsorption of CO on MgO and investigation of the energy gap of high T_c superconductors, are presented. Comparisons of the spectra with the experimental and theoretical literature …

The Effects Of Conditioned Reinforcers On Extinction When Delivered On Schedules Of Extinction, Linda L. Barnard

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of the present research was to examine extinction of responding with regard to the rapidity and thoroughness of the process when conditioned reinforcement was available on one of five schedules during extinction. Forty-five mixed-breed pigeons served as subjects with 15 in each of three experiments. Reinforcement training schedules were as follows: Experiment 1, continuous; Experiment 2, fixed ratio 15; Experiment 3, variable-interval one-minute. After training, subjects experienced one of five extinction procedures (here called schedules of extinction) which were as follows: traditional schedule without keylight did not provide conditioned reinforcement; traditional with keylight had the keylight on continuously …

The Effect Of Seasonal Cattle Grazing On California Bighorn Sheep Habitat Use, Melanie J. Steinkamp

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The effect of seasonal cattle grazing on a newly reintroduced population of California bighorn sheep (Ovis canadensis californiana) in Big Cottonwood Canyon, Idaho, was studied. The hypothesis that bighorn sheep avoid cattle was tested. The issue of avoidance between bighorn sheep and livestock is arguable. Some studies have found that bighorn sheep avoid cattle while others have found no response of bighorn sheep to cattle.

Evidence was found to document the avoidance of cattle by bighorn sheep. The size of the bighorn's home range and core area decreased with the movement of cattle into areas of high bighorn …

Day-Specific Time Use By Underachieving Adolescents, Dorothy Jean Cassingham

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The data for this study were obtained in October 1989 through the use of a 128-item questionnaire given to students attending an alternative high school in Ogden, Utah. The Rosenberg Self-esteem Scale was included as part of the questionnaire. A total of 166 usable questionnaires were received from the students.

The objectives of this research were to determine if relationships between self-esteem, race, gender, and religion and time use could be detected in at-risk adolescents. The data collected indicate that self-esteem, religion, gender, and race have only slight significance upon the self-reported time use of the alternative high school student. …

Production And Inefficiency, Arunava Bhattacharyya

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The overall purpose of this three-part dissertation is to specify and estimate various components of inefficiency in the production and profit-generating processes. Flexibility in inefficiency-measurement techniques is introduced using stochastic functional forms to overcome the restrictions of the simplifying assumptions used in previous studies. In addition, the profit function approach is used to measure firm specific inefficiency and to view profit inefficiency in the multiple output context. Empirical application of each approach is also attempted. Application of the measurement of the inefficiency component in the first two essays is made using data taken from Indian agriculture. The multiple output model …

Laramide Deformation In Precambrian Granitic Rocks, Northeastern Wind River Range, Wyoming, Mark A. Dubois

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Fractures and faults in the Jakey's Fork area, northeastern Wind River Range, Wyoming, caused by brittle Laramide deformation in the Precambrian granitic basement have been studied in detail at airphoto, outcrop, and thin-section scales. The study area is bounded on the south by the approximately east-west and vertical Jakey's Fork Fault and on the east by the approximately northwest-southeast and vertical Ross Lakes Fault. Both were active during Laramide deformation. Four distinct structural domains, defined by fracture pat terns and proximity to the two major faults nave emerged in this study. The areas are: 1) Along Ross Lakes Fault granite …