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Full-Text Articles in Life Sciences

Ecology Of Treeline Whitebark Pine (Pinus Albicaulis) Populations In Central Idaho: Successional Status, Recruitment, And Mortality, And A Spring Temperature Reconstruction From Whitebark Pine Tree Rings, Dana Lee Perkins May 2001

Ecology Of Treeline Whitebark Pine (Pinus Albicaulis) Populations In Central Idaho: Successional Status, Recruitment, And Mortality, And A Spring Temperature Reconstruction From Whitebark Pine Tree Rings, Dana Lee Perkins

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This research investigated the successional status of treeline whitebark pine (Pinus albicaulis) populations on 14 stands in central Idaho and used empirical statistical models to determine the principal factors affecting recruitment and mortality. The longest lived whitebark pines from four additional high-elevation sites were used to develop a tree-ring chronology to reconstruct over 1,000 years of average April-May temperature.

The assessment of stand structures using size-frequency distributions generally provides evidence that treeline whitebark pine populations are currently self-sustaining in areas of low to nonexistent incidence of white pine blister rust (Cronartium ribicola). However the presence of …


The Arginine Deiminase Pathway In Lactococci: Physiological Role And Molecular Characterization, Lan-Szu Chou May 2001

The Arginine Deiminase Pathway In Lactococci: Physiological Role And Molecular Characterization, Lan-Szu Chou

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Lactococcus is an economically important group in lactic acid bacteria (LAB) that are often used in the dairy industry as starters for cheese production. Good starter strains should possess the ability to grow, ferment milk sugar, and produce desirable flavor compounds during cheese making. Therefore, it is essential to understand the physiology of these starters during cheese processing in order to obtain high-quality cheese products.

Cheese manufacturing compromises several stress factors that affect the growth of starter lactococci. Among these stressed environmental parameters, sugar starvation is the most important one to overcome to obtain energy for cellular processes. It is …


Genetic Relationships Between Two Rare Plant Species, Aliciella Caespitosa And A. Tenuis, And Their Putative Progenitor, A. Subnuda, Carrie L. Mccracken May 2001

Genetic Relationships Between Two Rare Plant Species, Aliciella Caespitosa And A. Tenuis, And Their Putative Progenitor, A. Subnuda, Carrie L. Mccracken

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Isolated populations have potential to become new species that should have less genetic variation than their ancestors. Small populations are more likely to lose genetic variation, which is, thus, expected to be greater in ancestors. Aliciella caespitosa and A. tenuis, two endemic species, may be derived from small populations of A. subnuda, a widespread species. Chloroplast DNA sequences were used to test this hypothesis. Allozyme data were used to compare genetic variation and numbers of alleles. Chloroplast data do not support the proposed relationships between A. subnuda and the other two species. Allozyme data were not more variable …


Intensification In A Risky Environment: The Case Of Improving Private Grazing Land For Beef Production In Utah, Louise D. Sainsbury May 2001

Intensification In A Risky Environment: The Case Of Improving Private Grazing Land For Beef Production In Utah, Louise D. Sainsbury

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Utah ranchers commonly face risks to their livelihoods. The objective of this work was to determine if ranchers could make profitable improvements to private land forage given the combined threat of low beef prices, drought, and possible loss of public grazing.

We used linear programming (LINDO) to identify the most profitable solutions for private land investment with an 11-year simulation. Operations were divided into small, medium, and large size classes. Various forage improvements and public permits were options. Two phases of a beef price cycle (peak and trough) and 2 precipitation patterns (wet and drought) were combined as joint favorable …


Biochemistry And Application Of Exopolysaccharide Production In Mozzarella Cheese Starter Cultures, Brent Petersen May 2001

Biochemistry And Application Of Exopolysaccharide Production In Mozzarella Cheese Starter Cultures, Brent Petersen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study sought to investigate the role of the C55 undecaprenol lipid carrier in the production of exopolysaccharide (EPS), the effect of exopolysaccharide producing (EPS+) starter cultures on the viscosity of Mozzarella cheese whey, and the possible protective characteristics of capsular EPS against freezing and freeze drying. Efforts to investigate the role of the lipid carrier in EPS production employed pAMbacA, a plasmid that encodes an enterococcallipid kinase that confers bacitracin resistance by increasing intracellular levels of undecaprenol phosphate lipid carrier. Unfortunately, this avenue of study was thwarted by the inability to demonstrate bacA …


Morphometric Evaluation Of The Whitefish Complex In Bear Lake, Utah/Idaho, Alan Ward May 2001

Morphometric Evaluation Of The Whitefish Complex In Bear Lake, Utah/Idaho, Alan Ward

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Whitefish populations around the world have long been difficult to categorize taxonomically. The whitefish of Bear Lake, Utah/Idaho are no exception. There are three recognized species of Prosopium that are endemic to the lake. Two of these species, Prosopium spilonotus and Prosopium abyssicota, have previously been indistinguishable outside of spawning times. Previous studies have proposed additional taxa within P. spi/onotus to further complicate the identification among these taxa.

Morphological characteristics were quantified on wild whitefish from Bear Lake, as well as from progeny reared in the laboratory from the wild adult fish. The purported taxa were separated in the field …


Effectiveness Of Earthen Escape Ramps In Reducing Big Game Mortality In Utah, Mary L. Hammer May 2001

Effectiveness Of Earthen Escape Ramps In Reducing Big Game Mortality In Utah, Mary L. Hammer

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

One-way escape gates and earthen escape ramps are structures used to enable deer to exit the highway right-of-way along fenced roads. I compared the use of one-way escape gates and earthen escape ramps by mule deer on two highways in Utah to determine if deer exhibited a preference for either structure. Results showed that earthen escape ramps were used by mule deer 8-11 times more frequently than one-way gates. Highway mortality data suggest that the installation of the escape ramps likely reduced mortality of mule deer in both study locations, because we could not attribute reductions in mortality to decreased …


Energy, Fractal Movement Patterns, And Scale-Dependent Habitat Relationships Of Urban And Rural Mule Deer, Mark F. Mcclure May 2001

Energy, Fractal Movement Patterns, And Scale-Dependent Habitat Relationships Of Urban And Rural Mule Deer, Mark F. Mcclure

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

I studied the behaviors, movement dynamics, habitat relationships, and population characteristics of Rocky Mountain mule deer (Odocoileus hemionus) using urban and rural winter ranges in Cache Valley, Utah, from January 1994 to February 1998. There were 2 goals to my research endeavors. The first was to assess how and why the behaviors and demographic characteristics of urban deer differed from those of rural deer. The second was to assess the scale-dependent responses to habitat and the scale-dependent patterns of habitat use by deer living in each area. To accomplish the first goal, I compared the prevalence of migration, the spatial …


The Relationship Of Milk Urea Nitrogen And Dhia Production Variables In Western Commercial Dairy Herds, Rachael G. Johnson May 2001

The Relationship Of Milk Urea Nitrogen And Dhia Production Variables In Western Commercial Dairy Herds, Rachael G. Johnson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Monthly individual cow DHIA test records (approximately 90,000) from 96 Holstein and Jersey herds from Utah, Idaho, and Montana were analyzed used the Mixed procedure in SAS to determine the relationships of milk production parameters to milk urea N (MUN). Records spanned two consecutive years ending December 2000. Means for Holsteins were 34.1 kg/d milk yield, 15.2 mg/dl MUN, 3.18% milk protein, 3.5% milk fat, and 280,000 somatic cell count. Mean MUN for Holsteins was lowest in fall (Oct.-Dec) and highest in winter and spring. Cows with highest milk protein percent (≥ 3.2%) had lowest MUN over all levels of …


Reproductive Allocation And Survival In Grasshoppers: Effects Of Resource Availability, Grasshopper Density, And Parasitism, David Heath Branson May 2001

Reproductive Allocation And Survival In Grasshoppers: Effects Of Resource Availability, Grasshopper Density, And Parasitism, David Heath Branson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A major challenge in ecology is to understand intraspecific variation in life histories. Variation in resource availability can lead to differences in reproductive allocation and life histories. Grasshoppers are a good organism for the study of variation in life histories, since they exhibit life history plasticity in response to biotic and environmental factors. An optimality model for grasshoppers was developed that predicts optimal total allocation to reproduction and optimal effort-per-offspring as functions of resource availability and mortality. Relative allocation to reproduction is predicted to increase with resource availability, while relative allocation to survival declines. A resource-based trade-off between egg size …


Rangeland Resources Monitoring: Concepts And Practical Applications, Benny R. Bobwski May 2001

Rangeland Resources Monitoring: Concepts And Practical Applications, Benny R. Bobwski

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

How does one person manage and monitor a half million acres of rangelands towards a sustainable future? Through a journey that begins with the understanding of sustainability, I explore the monitoring concept, two of its applications, and summarize with an emphasis on the art and science of management. Sustainability is a concept that confuses many managers because it is so complex. However, if one considers adaptability as the complement to sustainability, and realizes that an adaptable organism is a sustainable organism, then a manager can relate because the emphasis shifts from that of stability for the future to that of …


Development Of A Bird-Avoidance Model For Naval Air Facility El Centro, California, Edward J. Zakrajsek May 2001

Development Of A Bird-Avoidance Model For Naval Air Facility El Centro, California, Edward J. Zakrajsek

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Bird strikes (collisions between birds and aircraft) pose a significant threat to aviation safety. For example, Naval Air Facility El Centro, California, lost an F-18 jet to a bird strike in October 1995. To help combat the bird-strike threat at Naval Air Facility El Centro, I developed a bird-avoidance model as a risk-management tool for the installation. It can be used to schedule flights at NAF El Centro and its two associated practice-bombing ranges during times of low-bird activity. I calculated bird-strike risks and published them in web-page format on both the installation's server and the USGS/Utah State University, College …


Relationship Between Cag Repeats Of The N Terminal Region Of The Androgen Receptor And Body Shape, Michael John Wen May 2001

Relationship Between Cag Repeats Of The N Terminal Region Of The Androgen Receptor And Body Shape, Michael John Wen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Androgen receptor (AR) gene CAG polymorphisms may be associated with body shape, and are associated with certain breast and prostate cancers. In addition, body shape is associated with risk for a variety of diseases, including heart disease, diabetes, and certain forms of cancer. The CAG repeat in exon l of the AR gene was quantified using Perkin Elmer Applied Biosystems GeneScan analysis software in 96 and 59 healthy Caucasian men and women, respectively, who were over the age of 50 years. All participants had body measurements taken and donated a blood sample. Waist measurements included circumferences at the 1) umbilicus …


Recreation, Livestock Grazing, And Protected Resource Values In The Grand Staircase-Escalante National Monument, Lael Palmer May 2001

Recreation, Livestock Grazing, And Protected Resource Values In The Grand Staircase-Escalante National Monument, Lael Palmer

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis reports the results of a project which identified differences in characteristics of Grand Staircase-Escalante National Monument user groups as they related to their perceptions of how they experience the Monument as recreationists. It explored opinions of four groups: hikers vs. hunters and pre-designation users vs. post-designation users. Responses of these groups were compared for attribution of perceived resource damage, feelings of crowding, acceptability of management action, and importance of identified monument values to their visit. In addition, characteristics of the users were examined to determine if demographic characteristics accounted for differences in perception toward the resources. Finally, how …


Economic Impact Of Snowmobiling In Utah, Ikuko Fujisaki May 2001

Economic Impact Of Snowmobiling In Utah, Ikuko Fujisaki

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this study was to estimate statewide and local economic impact resulting from snowmobiling activities in Utah to gain a better understanding of preferences and opinions of Utah snowmobilers. The results will provide valuable information for snowmobiling management.

The survey instrument was designed to describe trip behavior, snowmobiling-related trip and annual expenditures, level of satisfaction with Utah snowmobiling opportunities, and demographics. A telephone survey was conducted with randomly selected households with registered snowmobiles during the period from April to June 2000. A 54.5% response rate yielded 373 usable completed questionnaires for data analysis.

For economic impact analysis, an …