Digital Commons Network^™

Growth Responses Of Great Basin Plant Species To Variation In Nitrogen Availability, Carol J. Bilbrough

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

For this dissertation, I examined the ability of field-grown plants to capture N presented in enriched patches or in whole-plant pulses. I assessed root proliferation in N-enriched patches when Agropyron desertorum plants had been previously fertilized or shaded. All plants responded with increased root growth rates in N-enriched patches. However, root proliferation by shaded plants was 50% less than unshaded plants. Unexpectedly, plants with higher N status had greater root growth rates in enriched patches than plants that had not received N supplement. I concluded that plants already under competitive pressure above ground for light and below ground for nutrients …

Evaluation Of The Delta Waterfowl Foundation's Adopt-A-Pothole Project, Daniel S. Vice

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The establishment of dense nesting cover (DNC) for breeding waterfowl is a common management practice on large blocks of former agricultural land. The Delta Waterfowl Foundation's Adopt-A-Pothole (AAP) program establishes DNC adjacent to small wetland complexes to increase waterfowl use and productivity. I evaluated waterfowl use and nesting success on AAP lease sites in southwestern Manitoba in 993- 94 and compared the relative amount and success of overwater and upland nesting by mallards using these sites.

Diving duck breeding pair densities were higher on treatment sites in both 1993 and 1994 (P = 0.02 and 0.02, respectively). Dabbling duck …

Ecological Amplitude And Invasion Of Diffuse Knapweed At Yakima Training Center, Washington, Donna Denise Wilcox

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Diffuse knapweed (Centaurea diffusa) is an introduced annual or short-lived perennial from Eurasia that has become a threat to native rangelands in the Pacific Northwest. Military training activities on the Yakima Training Center (YTC) increase the likelihood that knapweed will expand its range at YTC. This study, conducted in a major watershed at YTC, focused on: 1) how a variety of environmental variables influences knapweed distribution, 2) the use of Landsat Thematic Mapper (TM) imagery to map existing knapweed populations, and 3) the use of a logistic regression model and geographical information systems (GIS) to create a potential …

An Integration Of Tillage And Herbicides To Control Jointed Goatgrass (Aegilops Cylindrica Host.) In Winter Wheat, Troy M. Price

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

An integrated management approach for jointed goatgrass control was investigated at two farms in northern Utah using three tillage regimes and tree herbicides. The tillage regimes included no tillage, conservation tillage, and conventional tillage. Each regime was composed of different tillage practices common in the Intermountain West. A preemergence herbicide, clomazone, and two postergance herbicides, 2, 4-D and glyphosate, were investigated. Greenhouse studies were also conducted to investigate clomazone efficacy and depth of planting of winter wheat and jointed goatgrass.

Differential sensitivity to clomazone between jointed goatgrass and winter wheat did not occur in the greenhouse for the rates tested. …

Association Of The Major Histocompatibility Complex With Autism, Wayne W. Daniels

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The pathogenesis of autism has proven difficult to characterize. However, in many recent studies, it is suggested that the onset of this disorder is the result of multiple etiological factors, which include genetic, immunologic, and viral elements.

Possible immunological influences found in subpopulations of patients with autism include decreased lymphocyte responsiveness, reduced natural killer cell activity, abnormal response to rubella vaccine, abnormal immune response to brain tissue, and decreased plasma levels of the fourth component of complement(C4). These aberrations and others imply a possible autoimmune mechanism in some cases for the development of autism.

C4 deficiencies have been found in …

An Interdisciplinary Theoretical Framework For The Mailed Questionnaire Process And The Development Of A Theory On Immediacy And Salience As Significant Variables Of Response Rates, Maribeth Christensen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The mailed questionnaire research process developed historically as part of the survey research movement, with guidelines and models drawn from an array of scientific research methods and disciplines. Although the mailed questionnaire has become one of the most popular research instruments for obtaining data beyond the reach of the observer, the response bias generated from the generally low return rate of the mailed questionnaire survey has remained a problem. For over three decades researchers have generated a plethora of research on the effectiveness of the various aspects of the mailed questionnaire process and the resultant impact of various constructs on …

Competitive Interactions Between A Native And Exotic Trout Species In High Mountain Streams, Heather M. Thomas

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Populations of the introduced book trout, Salvelinus fontinalis, have recently become more widespread and abundant in western North American streams, possible at the expense of native Colorado River cutthroat trout, Oncorhynchus clarki pleuriticus. We examined the intensity and potential mechanism of competition between these species.

Feeding experiments in laboratory stream channels showed that cutthroat trout feeding efficiency decreases in the presence of a brook trout. Decreased feeding efficiency appeared to be due to interference, as cutthroat trout were inactive in the presence of the brook trout. Evidence for interference competition in the feeding experiments was also given by the …

Manufacture, Shelf Stability, And Acceptability Of Aseptically Packaged, Unripened Soft Cheese Produced By Post-Ultra-High Temperature Acidulant Injection Of Ultrafiltered Milk Concentrate, Elena S. Moiseeva

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study investigated the manufacturing procedures and texture attributes of direct acid set of an unripened, shelf-stable cheese variety produced by the combined technologies of ultrafiltration and ultra-high temperature processing. Product evaluation included physical and chemical properties such as gel strength, syneresis, pH, moisture, protein, and fat. Whole milk was concentrated by ultrafiltration to 30, 35, and 40% total solids. Milk retentate was ultra-high temperature-processed by preheating to 65 or 77°C, sterilized at 141°C for 4 s by direct steam injection, flash cooled to approximately 62 or 72°C, homogenized in two stages at either 13.8/2.1 or 27.6/4.1 MPa, cooled to …

Microbiological And Sensory Effects Of Milk Processed For Extended Shelf Life And The Development Of Rapid Methods To Quantitate Spores And Lipase Activity, Michael R. Blake

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The initial aim of this work was to evaluate processing conditions for extended shelf life (ESL) milk to have a shelf life at refrigeration temperature of 60 d. Milk was processed on a pilot-scale ultra-high-temperature processing plant and evaluated for microbial and sensory quality over 60 d at 7°C storage. Results of this study showed that lower process temperatures were preferable to minimize cooked flavors and that the minimum safe processing temperature was 134°C for 4 s as determined by the destruction of bacterial spores in the processed milk.

Consumer preference panel results indicated that consumers preferred milk processed at …

A Comparative Study Of The Oxygen Uptake Between Nonmotorized And Motorized Treadmills, Michael S. Wood

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this study was to determine the effects of nonmotorized treadmill walking and motorized treadmill walking on VO₂ results, measured in ml•kg^-1•min^-1, of males and females, ages 20-30 at Utah State University, Logan, Utah, USA. The participants were required to walk at a pace of 3 miles per hour and 13% grade for a total exercise time of 9 minutes. The exercise time was broken up with 3-minute recovery periods. Oxygen uptake was measured continuously using a metabolic measurement cart. The data obtained from the metabolic cart were correlated for each treadmill to …

Anorexia Nervosa And Bulimia Nervosa: The Patients' Perspective, Benita J. Quackenbush

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Eating-disorder clients show low motivation, poor follow-through, and inordinate premature dropout rates in treatment. To date, little research has been conducted that might provide clinicians with an understanding of the critical factors that may aid clients' recovery. Such factors may be used by clinicians to better motivate clients to collaborate in treatment. The purpose of this study was to identify some of the critical factors that women with eating disorders believed were crucial in prompting or facilitating their recovery. Identification of these factors was accomplished through a systematic content analysis of semistructured interviews with recovered or recovering bulimics and anorexics. …

Guidelines For Roadside Revegetation To Create Wildlife Habitat In Northern Utah, Lars D. Anderson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Many species of wildlife use roadside vegetation as habitat. The ring-necked pheasant (Phasianus colchicus) utilizes roadsides for all types of cover. Because pheasants are nonmigratory and generally live their entire lives within a 1- to 2-mile radius, pheasants are excellent indicator species to predict both quantity and quality of roadside wildlife habitat. Pheasants were introduced to Utah in the late 1800's. Populations climbed until pheasant habitat occupied 2-4 percent of the total land area in Utah. Populations began to decrease in the 1950's. Since 1962, pheasant populations in Cache County, Utah have dropped 2.71 percent annually. Experts believe …

Post-Fire Succession And Disturbance Interactions On An Intermountain Subalpine Spruce-Fir Forest, Christopher A. Dicus

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Four general post-fire successional pathways leading to a climax Engelmann spruce (Picea engelmannii Parry)/subalpine fir (Abies lasiocarpa [Hook] Nutt.) forest were identified operating on the T.W. Daniel Experimental Forest in northern Utah. These included initial colonization by seral quaking aspen (Populus tremuloides Michx.), seral lodgepole pine (Pinus contorta Dougl. ex Loud.), colonization by lodgepole pine followed by a low intensity surface fire, and immediate colonization by late successional Engelmann spruce and subalpine fir.

Post-fire establishment of the late successional species occurred earliest in the Engelmann spruce/subalpine fir pathway followed by the lodgepole pine and lodgepole pine ground fire pathways, and …

Academic Goals, Achievement, And Age At First Sexual Intercourse: Reciprocal Influences, Paul L. Schvaneveldt

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study examined the reciprocal relationship between the age of first sexual intercourse and academic goals and achievement. It was hypothesized that lower educational goals and achievement were likely to be associated with an adolescent who initiated sexual intercourse at a younger age than those with higher educational goals and achievement. It was also hypothesized that initiating sexual activity early would be associated with a decrease in subsequent academic achievement and goals. Possible explanations are that the costs of engaging in sexual intercourse (pregnancy and sexually transmitted diseases) may deter adolescents from initiating intercourse. Weak attachment to parents and future …

Relatedness And Autonomy Aspects Of Self-Concept In 8- To 12-Year-Old Children, Cherie Martin

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this study was to look at age-associated changes in relatedness and autonomy in 8- to 12-year-olds. A psychosocial and attachment theory perspective was taken to help explain the integration of relatedness and autonomy issues. The influence of gender, parent involvement, and selected demographic variables was also considered. The sample included 94 children . This excluded those with single fathers or stepmothers.

Instruments used were (a) the relatedness, autonomy, and parent involvement portions of the Rochester Assessment Package for Schools (Wellborn & Connell, 1987); (b) an age appropriate revision of the Eriksonian Psychosocial Stage Inventory (Jones & Anderson, …

Adolescent Leisure-Time Activity And Problem Behavior: The Integration Of Three Major Explanatory Theories As A New, Gail B. Yost

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Adolescence has in recent decades gained attention as being salient for study of social trends. Increases in youth social problems are seen nationally, statewide, and locally. They include substance abuse, precocious sexual activity, related consequences of pregnancy and STDs, suicide and depression, truancy, running away, crime against property, and violent crime against persons.

This study integrates three major explanatory theories of adolescent behavior into a macro-synthesis. R. Jesser's Problem Behavior Theory emphasizes how problem behaviors do not occur singularly, nor do they justify unique prevention methods. T. Hirschi's Social Control Theory describes how adolescents with little or no attachment to …

Maternal Responsivity To A Child With A Disability: A Comparison In Single- And Two-Parent Families, Kristin Bollwinkel

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this research was to examine the differences between mothers in single- and two-parent families as they interact with their child with a disability. The sample consisted of 240 children with developmental disabilities and their mothers. Maternal interaction behaviors were measured using the Maternal Behavior Rating Scale. Demographic information, child characteristic measures, and family functioning variables were also considered. Analyses of covariance indicated that there were no differences between interaction behaviors of mothers in single- and two-parent families. However, relationships between income, education, and family cohesion, and the types of interactions displayed between mother and child were found. …

The Effects Of Therapist Gender On Group Therapy For Eating-Disordered Clients, Todd A. Soutor

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This present study examined the session-by-session content of group therapy for eating-disordered clients. The main objective of this study was to identify how therapist-client gender match affects group therapy process , regarding the disclosure of important issues relevant to eating-disordered clients. It was hypothesized that the group therapy process for eating-disordered clients would be qualitatively different if therapy was facilitated by a female as opposed to a male therapist. The evaluation of the research question required using an alternating treatments single-subject research design, in which the presentation of treatment conditions was counterbalanced across two therapy groups. The treatments consisted of …

An Investigation Of The Construct Validity Of The Preschool And Kindergarten Behavior Scales, Clarice E. Jentzsch

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A relatively recent measure, the Preschool and Kindergarten Behavior Scales (PKBS), has been developed to measure both problem behavior and social competence in young children. The primary purpose of this study was to examine the construct validity of the PKBS through the application of several validation procedures. Results of the study support construct validity of the PKBS. In a discriminant analysis, the PKBS classified correctly 89.36% of the 94 subjects. A secondary purpose of this study was to examine social-emotional behavior differences between kindergarten students who were divided into different behavioral status groups based on a teacher nomination procedure: a …

Child Care And Parental Beliefs In Korean-American Families, Wanjeong Lee

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this study was to investigate Korean-American families' beliefs about child development and their child-care practices. Questionnaires were distributed and mailed to wives of Korean-American dual-earner families residing in Utah with young children. Incorporated measures were the Suinn-Lew Asian Self-Identity Acculturation Scale (SL-ASIA), Maternal Expectations of Child Development, questions on the type of child care and its quality, and the Child Care Satisfaction Scale (CCSS). Seventy-three mothers filled out the questionnaire for 104 children's child-care situations.

Results showed that Korean-American mothers were moderately acculturated and held both American and Korean values concerning the growth and development of children. …

Measuring Nonuse Values For Wilderness Designation In Utah-By Contingent Valuation Method, Van R. Johnson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Since 1964, when Congress wrote the Wilderness Act, there has been an increasing amount of controversy between opponents and advocates of wilderness. Wilderness areas in Utah are not immune to this controversy. Public policy makers and land managers are in the middle of this debate. They have the responsibility to assess the resource and estimate the benefits and costs associated with creating policy.

This thesis focusses on helping policy makers and land managers recognize a benefit currently not being assessed. Nonuse values are values other than in situ use, where individuals have a value for existence of wilderness or a …

The Impact Of A Mountain Pine Beetle Epidemic On Wildlife Habitat And Communities In Post-Epidemic Stands Of A Lodgepole Pine Forest In Northern Utah, William E. Stone

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Natural disturbance events influence the patterns and processes in many forest ecosystems. Ecosystem management of coniferous forests in western North America requires the recognition of the importance that natural disturbance regimes have in achieving sustainable resource production and maintaining biological diversity . Mountain pine beetle epidemics have played an historic role in the succession and structure of lodgepole pine forests in this region. Their effects on wildlife habitat and communities are undocumented, but are presumed to be substantial. I sought to quantify these effects in forty 1-ha stands of monotypic, even-aged, mature lodgepole pine forest in northern Utah approximately 3-8 …

Assessing The Relative Utility Of Models Of Vegetation Dynamics For The Management Of Sagebrush Steppe Rangelands, Paul E. Hosten

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The literature, long-term temporal data sets, and spatial data points surrounding livestock watering pints within rangeland communities wearer used to examine common assumptions and concepts used in models of vegetation dynamics. Of the stability concepts examined, the constancy concept was invalidated using long-term relict area data, whereas long-term data following disturbance indicated that sagebrush-dominated areas could be considered as resilient under circumstances examined. Pioshpere as well as relict and post-disturbance data indicated that the individualistic notion of vegetation change was favored. Species showing the most predictability (based on repeatability of abundance curves, and spatial and temporal serial correlations) were sagebrush …

Meta-Analysis Of Home Visiting Research With Low-Income Families: Client, Intervention, And Outcome Characteristics, Christopher H. Morris

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Leaders in the field of home visiting and family support research have indicated that the inclusion of home visiting in comprehensive services for low-income families with young children can play a key role in improving a wide variety of outcomes for at-risk children and their families. These recommendations have been based in part on selected empirical findings from the home visiting literature. However, synthesis of empirical findings has proven difficult, due to the heterogeneity of this population and the diverse applications of home visiting as a service delivery strategy.

The present meta-analysis examined a representative sample of the peer-reviewed literature …

Effects Of Antioxidants On Development Of In Vitro Fertilized Bovine Embryos, Bret L. Anderson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Free radicals are short-lived molecules that can cause decreased embryonic development in vitro. Antioxidants are molecules that block free radical formation or guard against their harmful effects. Many studies have linked exposure of media to light and culturing of embryos in high (20%) oxygen concentrations to free radical production. Some of the antioxidants used in culture media are superoxide dismutase (SOD), catalase, zinc (II), ethylenedinitrilo tetraacetic acid (EDTA), mannitol, vitamin E, dimethyl sulfide, and taurine. Most research involving antioxidants and embryonic development has been conducted on non-farm animals, particularly mouse and rabbit. Studies have shown that antioxidants in vitro culture …

Winter Habitat Selection By American Marten (Martes Americana) In Newfoundland: Why Old Growth?, Gary S. Drew

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Although the American marten (Martes americana) generally is recognized as an obligate late-seral species, the factors dictating this association are poorly understood. Martens were studied in Newfoundland, Yellowstone National Park, and in a captive setting. As expected, use of habitat types was not proportional to availability P < 0.001). Defoliated and late-seral conifer stands were used more than expected, while all other types indicated expected or less than expected use. Habitat selection by martens was detectable at spatial scales greater than 80 m (P < 0.001).

Newfoundland martens were radio-collared and monitored for diet activity during the winters of 1990 and 1991. A regression of the percent active fixes on temperature had a negative slope (b = -4.45, P = 0.084, n = 12), indicating that martens did not minimize their exposure to low temperatures. A log-linear model suggested …

Effects Of Homogenization And Ultra-High Temperature Processing On The Properties Of Whole Milk Concentrated By A Multiple-Membrane Separation System, Chien-Ti Chang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Three different concentrated whole milks (2.5x, 2.75x, and 3.0x) were produced by mixing equal parts of ultrafiltration retentate of whole milk and reverse osmosis retentate of the UF milk permeate. The concentrated whole milks were ultra-high temperature processed by direct steam injection (140.6°C) followed by flash cooling and two-stage homogenization pressures (2500/500 psi, 3500/700 psi, or 4500/900 psi). The milk concentrates were packaged aseptically and stored at room temperature. On the other hand, the milk concentrates produced by the RO single membrane system with the same concentration levels served as the control. Physicochemical properties of the milks were surveyed every …

Identification Of Dna Markers In Triticum Aestivum-Aegilops Caudata Additions Lines By Randomly Amplified Polymorphic Dna (Rapd) Technology, Ling Wei

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The objective of this study was to identify DNA markers for each of six added C-genome chromosomes in Triticum aestivum L. cv. 'Alceso'-Aegilops caudata L. addition lines using the randomly amplified polymorphic DNA (RAPD) technique. DNA from Ae. caudata, T. aestivum, amphiploid of T. aestivum X Ae. caudata, and six disomic addition lines of wheat having a pair of Ae. caudata chromosomes was used as the template for the amplification of RAPD markers with a total of 58 random 10-mer oligonucleotide primers. Two primers, OPC-08 and OPJ-16, produced one intense band each from the amphiploid of …

Associations Of Armillaria Root Disease In Jack Pine With Arceuthobium Americanum, Elizabeth G. Hebertson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Relationships between jack pine dwarf mistletoe (Arceuthobium americanum Nutt. ex Engelm.) and Armillaria root disease (Armillaria ostoyae (Romagn.) Herink) were examined to determine how these two disease agents contribute to jack pine (Pinus banksiana Lamb.) decline and mortality in the Belair Provincial Forest, Manitoba, Canada. The incidence and extent of Armillaria root disease was strongly related to tree vigor. Dwarf mistletoe infection did not affect either the incidence of Armillaria or the mean percentage of root system colonization within vigorous, declining, and dead classes of trees. However, field observations and other analyses indicate that dwarf mistletoe was …

Behavioral Characteristics Affect Habitat Selection Of Domestic Ruminants, Cody B. Scott

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

I evaluated some of the factors affecting livestock distribution by conducting experimental (Chapters II and III) and observational (Chapter IV) studies. In Chapter II, I described the effect of locations of familiar foods and social interactions on choice of feeding location by lambs. Lambs were exposed to a pasture as subgroups of strangers and companions with different dietary habits (i.e., three lambs that preferred milo with three lambs that preferred wheat). Milo was placed on one end and wheat on the other, about 100 m apart. Strangers typically fed in different locations, reflecting dietary preferences. Conversely, companions fed in both …