Life Sciences Commons^™

The Reproductive Biology And Edaphic Characteristics Of A Rare, Gynodioecious Saxifage: Saxifraga Bryophora Var. Tobiasiae (Saxifragaceae), Kimberly Pierson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

I examined the reproductive biology and general ecology of Saxifraga bryophora var. tobiasiae, a rare saxifrage endemic to the West Salmon River Mountains of central Idaho. Saxifraga bryophora var. tobiasiae combines asexual reproduction via bulbils with a sexual mixed-mating system. Flower production occurred in 1996 only, whereas bulbil production occurred in 1995, 1996, and 1997. Bulbil production precedes floral bud formation and is the dominant form of reproduction. When flowering occurs, outcrossing is promoted by protandry and the gynodioecious mating system found in all populations. No autogamous or agamospermous seed set was observed in either female or hermaphrodite flowers, …

The Effects Of Salmon Availability, Social Dynamics, And People On Black Bear (Ursus Americanus) Fishing Behavior On An Alaskan Salmon Stream, Danielle K. Chi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The primary goals of this research were to investigate 3 ecological factors influencing black bear (Ursus americanus) foraging behavior on an Alaskan salmon (Oncorhynchus spp.) stream: fish availability, social dynamics, and human activity. Over 900 observation hours were logged at 2 falls from July 1-September 1 1993-1995; the lower falls were open to public for wildlife viewing, but the upper falls were restricted to research personnel.

In general, black bears responded to differences in fish accessibility on both spatial and temporal scales. All years of the study, 3 indices of bear activity (bear minutes, bear numbers, bout …

Utilization Of Spatially Distributed Soil Resources By Several Species Common To The Great Basin, Sarah Duke

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Heterogeneous spatial and temporal distributions of soil resources important to plant growth have been documented in the sagebrush steppe ecosystem. There can exist as much variability in soil resources within the root zone of individual plants as exists across an entire field. The objective of this dissertation research was to evaluate how plants respond to, utilize and influence the spatial heterogeneity of soil resources. The three specific sets of questions addressed are outlined in the three main chapters of this dissertation.

My first study addressed how the number and concentration of phosphorus (P) patches in the root zone of an …

Establishing Threshold Levels Of Nitrite Causing Pinking Of Cooked Meat, Kevin M. Heaton

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Sporadic problems with pink color defect, or pinking, has occurred in cooked meat products for decades. Pink color can be due to the presence of undenatured myoglobin, denatured globin hemochromes, or nitrosylhemochrome. This research documented the level of added nitrite that produced nitrosylhemochrome in processed meat rolls from fabricated beef round, pork shoulder, turkey breast, and chicken breast. For each meat type, preliminary studies were conducted to narrow the range at which added nitrite caused pinking. Subsequently, the nitrite levels were increased incrementally by 1-ppm, and pink color was measured by trained panelists and by a Hunter color meter. Nitrosylhemochrome …

Expression And Iron Loading Of Recombinant Ferritin Homopolymers, Jia-Hsin Guo

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Ferritin is an iron storage protein consisting of H and L chains to form a 24-subunit heropolymer. Ceruloplamin oxidizes Fe(II) and then loads the iron into ferritin. This research was conducted to determine which ferritin subunit is involved and whether a proposed iron-loading channel is required for iron loading by ceruloplasmin.

Recombinant rat liver H and L chain ferritin homopolymers, designated as rH-Ft and rL-Ft, respectively, were produced using insect cell-baculovirus and Escherichia coli expression systems. The expressed rH-Ft strongly suppressed the growth of the host. The rH-Ft expressed in the E. coli contained approximately 150 iron atoms/ferritin and was …

Ammonium And Nitrate Effects On Growth, Development And Nutrient Uptake Of Hydroponic Wheat, Thomas M. Hooten

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The long-term effects of low and high NH₄⁺/ NO₃^- uptake ratios in a system with rigorous control of pH and nitrogen concentration are poorly understood. In two replicate studies, two cultivars of wheat (Triticum aestivum) were grown to maturity with three NH₄⁺/ NO₃^- ratios in hydroponic solution: 0/100, 25/75, and 85/15%. Nitrogen was controlled at ample levels throughout the 70-d life cycle and pH was controlled at 5.8 ± 0.2. An equimolar ratio of NH₄⁺ to Cl^- was used to facilitate charge balance. Nitrogen consumption …

Predicting Transpiration Rates Of Hydroponically-Grown Plant Communities In Controlled Environments, Oscar Monje

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Canopy transpiration is a major factor determining crop evapotranspiration and energy budgets. Unfortunately the development of robust models of canopy transpiration is hindered by a lack of reliable data due to the difficulties of making canopy-scale measurements. However, measurements of canopy water vapor and carbon fluxes via gas exchange techniques are possible in controlled environments. Simultaneous measurements of transpiration, photosynthesis, and canopy temperature were made in wheat and soybean communities. These data were used to calculate chamber aerodynamic and canopy stomata! conductances, and to model the response of canopy transpiration to CO₂concentration and vapor pressure deficit. Canopy stomata! …

Kokanee Fry Recruitment And Early Life History In The Lake Tahoe Basin, Christine K. Gemperle

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Lake Tahoe kokanee salmon have experienced decreasing mean adult size and fluctuating populations since 1970. We proposed to determine whether fish production was limited by spawning and incubation processes in Taylor Creek, or by growth constraints, or by mortality in the lake by studying egg-to-fry survival rates and early life history. Estimated egg-to-fry survival was 15. 9% for the 1994 brood year and 1.5% for the 1995 brood year. Egg-to-adult survival was 3.5% for the 1991 brood year and 5.9% for the 1992 brood year. Of the 35 possible survival scenarios, egg-to-fry survival was 7.5-20% and fry-to-adult survival (inlake phase) …

Use Of The Water Erosion Prediction Project (Wepp) Model To Predict Road Surface Erosion In Mountain Rangeland Areas, Brian J. Zalewsky

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A significant source of sediment in many watersheds is that associated with the layout, construction, and maintenance of roadways. Much work has been done in more mesic forested environments with little or none in semiarid systems. Accurate estimation of runoff and sediment yield from native surfaced roads located in semiarid mountainous ecosystems is important to both private and public regulatory agencies. The Watershed Erosion Prediction Project (WEPP) model represents the most current erosion prediction technology. WEPP has been applied to the problems of logging road erosion in more mesic forests but has not been tested or evaluated on roadways located …

Influence Of Streptococcus Thermophilus Mr-1c Capsular Exopolysaccharide On Cheese Moisture Level, Deborah Low

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study investigated the role of exopolysaccharide (EPS) in cheese moisture retention. Analysis of low-fat Mozzarella cheese made with different combinations of EPS-producing (Streptococcus thermophilus MR-1C and Lactobacillus delbrueckii ssp. bulgaricus MR-lR) and non-EPS-producing (S. thermophilus TA061 and L. helveticus LH100) starters showed significantly higher moisture levels in cheese made with S. thermophilus MR-1C. To determine if the S. thermophilus MR-1C EPS was responsible for increased moisture retention, gene replacement was used to inactivate the epsE gene in this bacterium. Low-fat Mozzarella cheese made with L. helveticus LH100 plus the EPS-negative mutant, S. thermophilus DM1O, had significantly lower …

Characterization Of The Proteolytic System In Lactococcus Lactis Starter Cultures, Christina Beer

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The proteolytic system of Lactococcus lactis starter cultures influences both flavor and the characteristic body and texture of cheese. The ability to further understand and control how different components of this proteolytic system work together to hydrolyze milk proteins would be of immense importance to the dairy industry.

The goal of this research was to characterize Lactococcus lactis subsp. lactis starter bacteria with varying prt operon compositions by proteinase specificity, aminopeptidase and lipase activities, growth, and influence on cheese flavor. By using a cheese slurry system, a statistical model to predict milk protein hydrolysis patterns was developed.

Lactococcus lactis subsp. …

Modeling Soil Loss To Determine Water Erosion Risk At Camp Williams National Guard Base, Utah, Kevin P. Bartsch

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Soil erosion was assessed at Camp Williams National Guard Base by creating an erosion risk classification map and comparing the erosion impact of disturbance regimes on different hillslopes. Soil erosion does not appear to be a problem for most of Camp Williams.

The Revised Universal Soil Loss Equation was applied using GIS to create a soil erosion risk map for the entire Camp Williams facility. The map indicated where problem areas occurred and showed relative erosion risk, but its lack of quantitative accuracy should be noted. Areas of concern included landscapes with little or no protective vegetation such as roads, …

Attitudes And Roles Of Women And Minorities In Community And Urban Forestry Professions, Hope A. Bragg

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Community and urban forestry is a multifaceted field ranging from tree planting to removal, hazard assessment, and public relations. However, the racial and gender diversity of the community forestry workforce is remarkably low. To gain a better understanding of this lack of diversity, I surveyed professionals in two major community/urban forestry organizations. Age, income, and years in the profession were considered, along with education level, to determine if there is some underlying reason for low representation of women and minorities in the community/urban forestry field. I found that while white males dominated all work sectors (especially private organizations), women were …

Aspen Regeneration And Response To Fire In The Intermountain West, Kelly J. Mccloskey

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The history of Populus tremuloides regeneration in the Intermountain West, particularly western Wyoming, is one of prolific vegetative reproduction following wildland fire. The reproductive physiology of aspen and its disturbance-response characteristics are explored through a review of previous studies. The combination of fire suppression and increased herbivory on aspen by wild and domestic ungulates is likely facilitating conifer invasion of areas historically dominated by aspen as has been observed in parts of Wyoming, Utah, and Colorado over the past 100 years. A case study of the regenerative response of aspen to wildland fire in western Wyoming demonstrates how physiology, life …

Effect Of Aging On The Quality Of Beef Semitendinosus Muscle Treated With Ultra High Temperature Pasteurization, Habiba Ali Nur

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The objective of this study was to determine the effect of aging on the tenderness and palatability of beef from the semitendinosus muscle of the round. Tenderness may be affected by the length of the aging period and the aging temperature. Steaks from the semitendinosus muscle were stored for 0, 3, 6, 9, 12, and 24 hr at two temperatures, 43.3°C and 2.2°C. Ultra high temperature (UHT) pasteurization was accomplished by subjecting the meat to 1100°C for 20 seconds. UHT pasteurization denatures surface proteins, destroys vegetative pathogens, and eliminates some spoilage organisms from the surface of the meat. UHT -treated …

Study Of Ripening Characteristics Of Full-Fat And Low-Fat Cheddar Cheese Using Fourier Transform Infrared Spectroscopy And Texture Analyzer, Manxiang Chen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A suitable microtome sampling technique was used to sample cheese for analysis using FTIR spectroscopy. Well-separated fat- and protein-related bands were obtained in the spectra of Cheddar and Mozzarella cheese samples using this method. The absorbance intensity of the spectra was proportional to the thickness of the sample. The intensity of absorbance and fat- and protein-related bands increased with an increase in the fat and protein content in the sample. Strong and well-separated bands at 1744, 1450, 1240, 1170, and 1115 cm^-1 arising mainly from fat content were observed using this method. Bands observed at 1650 and 1540 cm …

Diet, Health Practices, And Variables Associated With Breastfeeding In Caucasian And Asian Participants In The Special Supplemental Food Program For Women, Infants, And Children: A Comparative Study, Rebecca E. Blaine

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The United States Department of Health and Human Services wrote Healthy People 2000 National Health Promotion and Disease Prevention Objectives. One major goal is to reduce the mortality rate for infants by reducing low birthweight. The disparities have been great when goals and objectives are applied to poor and minority populations.

Objectives have been set to reduce risk factors associated with low infant birthweight. These include addressing inappropriate health practices, and appropriate nutrition for mother and infant.

Forty-eight Asian and 50 Caucasian participants were compared for maternal diet, health practices, breastfeeding initiation and duration, and infant growth parameters. Data were …

Tryptophan Catabolism By Lactobacillus Spp. : Biochemistry And Implications On Flavor Development In Reduced-Fat Cheddar Cheese, Sanjay Gummalla

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Amino acids derived from the degradation of casein in cheese serve as precursors for the generation of key flavor compounds. Microbial degradation of tryptophan (Trp) is thought to promote formation of aromatic compounds that impart putrid fecal or unclean flavors in cheese, but pathways for their production have not been established. This study investigated tryptophan catabolism by Lactobacillus casei LC301 and LC202 and Lactobacillus helveticus CNRZ32 and LH212 cheese flavor adjuncts in carbohydrate starvation (pH 6.5, 30 or 37°C, no sugar) and cheese-like conditions (pH 5.2, 4% NaCl, 15°C, no sugar). Enzyme assays of cell-free extracts revealed both species of …

Identification Of Non-Nuclear Receptors For 1,25-Dihydroxyvitamin D3 In Chick Kidney And Brain, Zhiheng Jia

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

1,25-dihydroxyvitamin D₃ (1,25(OH)₂D₃) has been shown to mediate the rapid, non-nuclear stimulation of calcium and phosphate transport in chick intestine through binding to a receptor localized in the basal lateral membrane. By using an antibody to the N-terminus of the membrane receptor, studies were undertaken to determine whether a comparable protein exists in kidney and brain, and whether it is present in a particular subcellular fraction.

The first step was to establish fractionation protocols to separate subcellular organelles as judged by marker enzyme analyses. Differential centrifugation and Percoll gradient fractions were prepared from chick kidney …

Influence Of Stress Treatments On The Resistance Of Lactococcus Lactis To Freezing And Freeze-Drying, Chan Lin

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study investigated the effect of cold, heat, or osmotic shock treatment on the resistance of L. lactis subsp. cremoris MM160 and MM310 and Lactococcus lactis subsp. lactis MM210 and FG2 cheese starter bacteria to freezing and freeze-drying. The ability to withstand freezing at -60°C for 24 h was variable among lactococci, but resistance to this treatment was significantly improved (P < 0.05) in most strains by a 2-h cold shock at l0°C or a 25-min heat shock at 39°C (L. lactis subsp. cremoris) or 42°C (L. lactis subsp. lactis). Stress treatments that improved lactococcal freeze resistance were also found to significantly (P < 0.05) enhance the resistance of most strains to lyophilization. Increased resistance to freezing or lyophilization was not detected when stress treatments were performed in broth that contained erythromycin, which indicated stress-inducible proteins were involved in cell protection. Membrane fatty acid analysis of stress-treated cells suggested that enhanced resistance to freezing and lyophilization may be related to heat or cold shock-induced changes in cell membrane composition. Heat-shocked cells had a higher 19:0 cyclopropane fatty acid content than did control cells, and cold-shocked cells contained a lower ratio of saturated to unsaturated fatty acids. Other factors must also be involved in cell protection, however, because similar changes in membrane composition were also detected in strains whose resistance to freezing and lyophilization was not improved by heat or cold shock.

Improving Fat Retention And Texture In Low-Moisture Cheese Manufactured From Ultrafiltered Milk, Brian J. Orme

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Three serious problems have been experienced in the manufacture of low moisture cheese using ultrafiltration (UF)- high fat-loss, excessive moisture retention, and poor cheese texture. In this work the causes of these problems were identified, and means of overcoming them were developed.

Coagulation and cheese-making experiments indicated that UF concentration of milk shifts the control of rennet coagulation toward the casein micelle collision rate and away from rennet activity, resulting in formation of a rough-textured curd structure that resists syneresis. Use of 4x whole milk retentate, instead of 5x, improved rennet curd structure, syneresis, and UF cheese texture without reducing …

Antioxidant Activity Of Carnosine And Phytate: Application As Meat Preservatives, Beom Jun Lee

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The antioxidant activity of carnosine and phytic acid was investigated using several model systems. Carnosine and phytic acid alone inhibited metal ion-catalyzed deoxyribose degradation. Carnosine strongly inhibited metal ion-catalyzed lipid peroxidation in liposomes and in ground beef homogenates. Phytic acid facilitated oxidation of Fe (II) to Fe (III), and it inhibited hemeprotein + H₂O₂-catalyzed lipid peroxidation in linoleic acid micelles.

Antioxidant and color stabilizing effects of carnosine and phytate were investigated in a beef model system. Both compounds increased the rate of pH decline in pre-rigor beef muscle and stabilized fresh meat color by inhibiting metmyoglobin …

The Effects Of A Very-Low-Calorie-Diet On Resting Energy Expenditure, Body Composition, And Biochemical Data In Obese Outpatients, Charlene A. Perkins

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Obesity is a disease of major proportion in the United States. The Surgeon General has identified obesity as a national health problem that affects approximately 34 million Americans.

The aim of this study was to investigate the very-low-calorie diet, Optifast 70. Measurements for resting energy expenditure (REE} and body composition via circumference measurements (CBF} and infrared photospectromerty (NIR} with a Futrex 5000 were collected at weeks 1, 7, 13, 19, and 25. Biochemical data, including serum chemistry panel (SMA-12} and complete blood count (CBC}, were collected on weeks 1, 5, 9, 13, 17, 21, and 25. Lipid profiles were drawn …

Development And Validation Of Forest Habitat Models In The Uinta Mountains, Utah, Tracey S. Frescino

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A significant question currently facing environmental managers is how to accurately and efficiently quantify forest diversity and resources. Numerous studies have demonstrated the use of modern spatial analytical tools, such as geographical information systems (GIS), remote sensing devices, and statistical models for predicting the distribution of dominant vegetation cover types. This study examines the ability of generalized additive models (GAMs) to delineate structural diversity in forested ecosystems (specifically the Uinta Mountain Range in Utah) using GIS tools and satellite spectral data, and analyzes the effect of including different forms of satellite data in model construction (i.e., Landsat thematic mapper (TM), …

Regeneration Ecology Of Chrysopogon Aucheri And Cymbopogon Jwarancusa In Grasslands Of Upland Balochistan, Pakistan, Sarfraz Ahmad

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Field experiments were conducted to investigate the seed attributes, movements and fates of dispersal units, and seedling establishment of Chrysopogon aucheri and Cymbopogon jwarancusa in a representative grassland ecosystem in upland Balochistan, Pakistan.

Cymbopogon jwarancusa had more filled and viable caryopses than Chrysopogon aucheri. Seeds (spikelets) of both species had similar morphological features. Chrysopogon aucheri had one dispersal unit, a triplet spikelet. Cymbopogon jwarancusa had four types of dispersal units: a paired spikelet, a partial raceme, an entire raceme, and a partial inflorescence comprised of two racemes.

Paired spikelets and partial racemes of Cymbopogon jwarancusa had greater …

Grassroots Of The Desert: An Analysis Of The Roles Of The Utah Wilderness Association And The Southern Utah Wilderness Alliance In The Debate Over Wilderness Designation Of Bureau Of Land Management Lands In Southern Utah, Amy E. Brennan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The battle over federal Wilderness designation of Bureau of Land Management lands in southern Utah has entered its third decade. Throughout this lengthy debate numerous stakeholders have maintained involvement, including members of Utah's conservation community. Two of the most prominent wilderness advocacy groups in Utah are notable not only for their sustained involvement with the issue, but also for their divergent positions on how to resolve this public land dispute. This research examines those two organizations, the Utah Wilderness Association and the Southern Utah Wilderness Alliance, through an analysis of their respective structural, organizational, philosophical, and tactical perspectives.

Ultimately, the …

Livestock Watering Practices In The Moroccan Pre-Sahara: Their Effects On Water And Nutrient Metabolism Of Sheep In Different Body Conditions, El Mostafa Darfaoui

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A field survey and a metabolism experiment were conducted to study livestock watering practices in the Moroccan Pre-Sahara and their changes with drought extent, season, ecological zone, pastoral system, and herd size. The metabolism experiment was designed to determine effects of once per 2 days (ID), once daily and twice daily drinking frequencies, and high and low body conditions on water and nutrient utilization by sheep fed high- and low-quality diets.

The way herds are managed in this region exposes all sex and age categories of animals to food and water shortages during annual dry seasons and occasional droughts. Livestock …

Management Of Microbial Nitrate Production In Agricultural Soils, Wei Shi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Nitrate (NO₃^-) is of central importance in the internal soil nitrogen (N) cycle. While animal wastes and nitrification inhibitors have been used in modern agriculture for decades, their effects on soil NO₃^- concentrations in relation to microbial NO₃^- production have not been well characterized. The objective of this research was to determine microbial NO₃^- production in relation to ammonium (NH₄⁺) availability and nitrifier population activity in agricultural soils receiving animal wastes or nitrification inhibitors.

Several laboratory and field studies assessed the impacts of variously treated dairy wastes and …

The Role Of Ammonia In Reproductive Inefficiency In High-Producing Dairy Cows Fed Excess Rumen Degraded Protein, Douglas Scott Hammon

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The role of ammonia in reproductive inefficiency in early lactation dairy cows was studied in a series of experiments designed to determine the concentrations of ammonia in normal bovine follicular fluid (bFF), to determine the effects of ammonia on the bovine embryo during specific stages of development, and to test the hypothesis that elevated plasma urea nitrogen concentration is associated with elevated ammonia and urea nitrogen concentrations in the reproductive fluids.

In the first study, ammonia concentration in different size follicles and the effect of ammonia during in vitro maturation on embryo development were determined. Ammonia concentration in the bFF …

Protein Production In The Milk Of Genetically Engineered Animals, Katherine M. Bates

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

There are numerous proteins that have potential uses in commercial and scientific applications that are not utilized to their full potential. this is partly because it is not economically feasible to isolate some of these proteins from their natural sources or to produce them using bacterial fermentation methods. The purpose of this research was to target recombinant protein expression to the mammary glands of genetically engineered or transgenic animals. Foreign protein expression has been achieved in the mammary glands of rabbits, sheep, cows, and swine. By using a strong mammary gland promoter and signal peptide fused to the protein, it …