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Expression And Iron Loading Of Recombinant Ferritin Homopolymers, Jia-Hsin Guo
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 …
Protein Production In The Milk Of Genetically Engineered Animals, Katherine M. Bates
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 …
Predicting Transpiration Rates Of Hydroponically-Grown Plant Communities In Controlled Environments, Oscar Monje
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! …
Limitations On Canada Goose Production At Fish Springs National Wildlife Refuge, Utah, Dorie S. Stolley
Limitations On Canada Goose Production At Fish Springs National Wildlife Refuge, Utah, Dorie S. Stolley
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Canada geese (Branta canadensis) recently have become management problems in some areas due to overpopulation. At Fish Springs National Wildlife Refuge (NWR), managers are concerned with the opposite situation. Despite attempts to boost production, only 18 to 34 goslings of the western Canada goose (B. c. moffitti) were produced per year, from 1989 to 1993. I studied the breeding population from March to July in 1996 and 1997. Results suggest that production is limited in 3 ways: low gosling survival, low nesting success for ground nests, and low number of breeding pairs.
Gosling survival to fledging …
Identification Of Non-Nuclear Receptors For 1,25-Dihydroxyvitamin D3 In Chick Kidney And Brain, Zhiheng Jia
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 …
Antioxidant Activity Of Carnosine And Phytate: Application As Meat Preservatives, Beom Jun Lee
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 …
Parental And Teacher Priorities For Children's Requisite Kindergarten Entry Skills, Kelly J. O'Claire-Esparza
Parental And Teacher Priorities For Children's Requisite Kindergarten Entry Skills, Kelly J. O'Claire-Esparza
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
This study examined mothers', fathers ', preschool teachers', and kindergarten teachers' opinions regarding children's requisite kindergarten entry skills. Participants were 101 preschool teachers from eight counties in northern Utah, as well as 113 kindergarten teachers and 286 parents of kindergartners from five school districts in northern Utah. Questionnaires were administered to assess opinions regarding (a) the preschool teachers' role in preparing children for kindergarten, (b) the parental role in preparing children for kindergarten, (c) priorities for requisite kindergarten entry skills, (d) the importance of specific skills emphasized in preschool, and (e) the importance of specific skills emphasized in kindergarten.
Findings …
Therapy Videotape Presentation For Eating Disorder Clients: Development And Evaluation, Benita J. Quakenbush
Therapy Videotape Presentation For Eating Disorder Clients: Development And Evaluation, Benita J. Quakenbush
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. Earlier studies support the use of pretherapy training to help clients understand the tasks and challenges of therapy. However, a pretherapy intervention, such as showing prospective clients a video that outlines recovery issues and themes, had not yet been developed specifically for the prevalent, recalcitrant problem of eating disorders. Thus, of particular interest to clinicians who treat eating disorders may be the development of a theoretically sound, pretherapy videotape that outlines recovery issues.
One of the purposes of this study was to review prior investigations …
Management Of Microbial Nitrate Production In Agricultural Soils, Wei Shi
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
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 …
The Effects Of Retinoic Acids On The Angiogenic Growth Factors Produced By Solid Tumors, Lynn C. Burgess
The Effects Of Retinoic Acids On The Angiogenic Growth Factors Produced By Solid Tumors, Lynn C. Burgess
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
These studies investigated the effects of retinoic acid (RA) on angiogenesis. Three human, neoplastic cell lines were used to examine angiogenic promotion and/or inhibition. The cell lines, U-373MG glioblastoma, DU-145 prostate carcinoma, and TCCSUP bladder transitional cell carcinoma, were treated with the following: all-trans, 9-cis, or 13-cis RA, at doses from 0.0001 to 100 μM. Hypoxia was used to assist the expression of the angiogenic phenotype. Conditioned media (CM) were prepared by growing the tumor cells in the presence of RA and hypoxia for 24 hours, and then the CM was transferred to bovine, capillary endothelial …
The Effect Of The Estimate Of Resting Metabolic Rate On The Correlation Between Energy Expenditure As Estimated Using Self-Reports Of Physical Activity And Food Intake Records In Older Adults, Judy Hurd
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
This study measured total daily energy expenditure (TDEE) in adults at least 50 years of age. The goal was to determine the effect of the estimate of resting metabolic rate (RMR) on the relationship between energy expenditure estimates made using (a) self-reports of physical activity and (b) food intake records. The objectives were to determine if (a) RMR estimates based on body composition, body weight, and the metabolic cart were strongly related to each other, and (b) TDEE estimates based on a 7-day physical activity diary and a 7-day food intake record were more strongly related to each other when …
Pretherapy Videotape Presentation For Eating Disorder Clients: Development And Evaluation, Benita J. Quakenbush
Pretherapy Videotape Presentation For Eating Disorder Clients: Development And Evaluation, Benita J. Quakenbush
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. Earlier studies support the use of pretherapy training to help clients understand the tasks and challenges of therapy. However, a pretherapy intervention, such as showing prospective clients a video that outlines recovery issues and themes, had not yet been developed specifically for the prevalent, recalcitrant problem of eating disorders. Thus, of particular interest to clinicians who treat eating disorders may be the development of a theoretically sound, pretherapy videotape that outlines recovery issues.
One of the purposes of this study was to review prior investigations …
Utilization Of Spatially Distributed Soil Resources By Several Species Common To The Great Basin, Sarah Duke
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 …
Ammonium And Nitrate Effects On Growth, Development And Nutrient Uptake Of Hydroponic Wheat, Thomas M. Hooten
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 …
Influence Of Streptococcus Thermophilus Mr-1c Capsular Exopolysaccharide On Cheese Moisture Level, Deborah Low
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 …
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 …
Effect Of Aging On The Quality Of Beef Semitendinosus Muscle Treated With Ultra High Temperature Pasteurization, Habiba Ali Nur
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 …
Tryptophan Catabolism By Lactobacillus Spp. : Biochemistry And Implications On Flavor Development In Reduced-Fat Cheddar Cheese, Sanjay Gummalla
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 …
Characterization Of The Proteolytic System In Lactococcus Lactis Starter Cultures, Christina Beer
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. …
Establishing Threshold Levels Of Nitrite Causing Pinking Of Cooked Meat, Kevin M. Heaton
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 …
The Effects Of A Very-Low-Calorie-Diet On Resting Energy Expenditure, Body Composition, And Biochemical Data In Obese Outpatients, Charlene A. Perkins
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 …
Influence Of Stress Treatments On The Resistance Of Lactococcus Lactis To Freezing And Freeze-Drying, Chan Lin
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
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 …
Regeneration Ecology Of Chrysopogon Aucheri And Cymbopogon Jwarancusa In Grasslands Of Upland Balochistan, Pakistan, Sarfraz Ahmad
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 …
Livestock Watering Practices In The Moroccan Pre-Sahara: Their Effects On Water And Nutrient Metabolism Of Sheep In Different Body Conditions, El Mostafa Darfaoui
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 …
Seed Dispersal By Livestock: A Revegetation Application For Improving Degraded Rangelands, Ferhat Gokbulak
Seed Dispersal By Livestock: A Revegetation Application For Improving Degraded Rangelands, Ferhat Gokbulak
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
A series of experiments was conducted to: 1) investigate how feeding cattle with different amounts of different-sized seeds affects seed passage rate through the digestive tract, and the germinability of passed seeds; 2) examine how the location of seeds in dungpats of different thicknesses influences seedling emergence, development, and survival in cattle dungpats; and 3) characterize seedling emergence in naturally and artificially deposited cattle dungpats. Three perennial, cool-season grasses, bluebunch wheatgrass [Psuedoroegneria spicata (Pursh) A. Love], Sandberg bluegrass (Poa secunda Presl.), and 'Hycrest' crested wheatgrass [Agropyron desertorum (Fisch. ex Link) X A. cristatum (L.) Gaert.], were used …
Aspen Regeneration And Response To Fire In The Intermountain West, Kelly J. Mccloskey
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 …
A Comparison Of The Impact Of Two Different Levels Of Item Response Effort Upon The Return Rate Of Mailed Questionnaires, Philip L. Rodgers
A Comparison Of The Impact Of Two Different Levels Of Item Response Effort Upon The Return Rate Of Mailed Questionnaires, Philip L. Rodgers
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Mail questionnaires are a popular and valuable method of data collection. Nonresponse bias is, however, a potentially serious threat to their validity. The best way to combat this threat is to obtain the highest possible return rate. To this end, many factors that are believed to influence return rates have been empirically studied. One factor that has not been empirically examined is the impact of item response effort on return rates, where response effort is defined as the amount of effort that is required by a respondent to answer questionnaire items.
The purpose of this study was to determine if …