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Full-Text Articles in Life Sciences

Characterization Of An Axial Ligand Substitution In Sperm Whale Myoglobin, Michael J. Chen May 1995

Characterization Of An Axial Ligand Substitution In Sperm Whale Myoglobin, Michael J. Chen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Of central importance to the study of heme proteins are the effects imposed by axial ligand(s) on the heme structure and, therefore, on the overall activity of the protein. In this study, we confirm and extend the spectroscopic characterization of a mutated sperm whale myoglobin in which the proximal Histidine is replaced with a Tyrosine residue (MbH93Y). The MbH93Y, as well as wild-type sperm whale myoglobin and horse erythrocyte catalase (HEC), was purified and characterized by optical absorption and x-ray absorption (XAS) spectroscopies. Optical absorption spectra of HEC and the metmyoglobin, cyanometmyoglobin, reduced, oxy, and carbon-monoxy forms of both sperm …


Extended X-Ray Absorption Fine Structure And Redox Potential Studies Of Heme-Substituted Horseradish Peroxidase And Myoglobin, Bing He May 1995

Extended X-Ray Absorption Fine Structure And Redox Potential Studies Of Heme-Substituted Horseradish Peroxidase And Myoglobin, Bing He

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Heme-substituted horseradish peroxidases and myoglobins were reconstituted from the apoenzyme using mesoheme and diacetyldeuteroheme. X-ray absorption spectroscopy was used to determine the dimensions of the active sites of these heme-substituted proteins, and were compared with those of the proto-hemeproteins. The change in the active-site structure corresponded with the electron withdrawing and donating effects of the different side chains. The oxidation-reduction potentials of Fe4+/Fe3+ couples of the heme-substituted proteins were measured at pH 7 with K2IrCl6. The oxidation-reduction potential sequence for compound I/compound II was diacetyldeutero- > proto- > meso- in horseradish peroxidase. The oxidation-reduction potential …


Associations Of Armillaria Root Disease In Jack Pine With Arceuthobium Americanum, Elizabeth G. Hebertson May 1995

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 …


Post-Fire Succession And Disturbance Interactions On An Intermountain Subalpine Spruce-Fir Forest, Christopher A. Dicus May 1995

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 …


Disease And Habitat Change As Factors Associated With Mourning Dove Population Decline, William D. Ostrand May 1995

Disease And Habitat Change As Factors Associated With Mourning Dove Population Decline, William D. Ostrand

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The western mourning dove (Zenaida macroura) population has been declining since 1966. Data collected in 1951-52, in Fillmore, Utah, provided us a baseline for comparison with our study in the same area. Our approach was to determine whether a local population decline had occurred since the original data were collected, assess if trichomoniasis has impacted the local population, determine if changes in habitat structure affect foraging site selection, quantify changes in habitat, identify which habitats doves preferred, ascertain whether doves had responded to habitat change by changing food habits, and assess if changes in habitat were responsible in …


Behavioral Characteristics Affect Habitat Selection Of Domestic Ruminants, Cody B. Scott May 1995

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 …


Competitive Interactions Between Two Closely Related Rhizomatous And Caespitose Perennial Grasses Under Varying Conditions, L. David Humphrey May 1995

Competitive Interactions Between Two Closely Related Rhizomatous And Caespitose Perennial Grasses Under Varying Conditions, L. David Humphrey

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Biomass, tiller numbers, flowering, and genet survival were accessed for the rhizomatous Elymus lanceolatus ssp. lanceolatus and caespitose E. l. ssp. wawawaiensis growing in mixtures with a range of densities of each taxon. Models of aboveground biomass of each taxon as a function of mixed densities were used to calculate competition indices. Tiller numbers and biomass of ssp. lanceolatus were higher than those of the caespitose taxon in the first year, but declined in the second year, while biomass and tiller numbers of ssp. wawawaiensis changed little. All tillers of ssp. wawawaiensis emerged in autumn; tillers of ssp. …


Ontogenetic Habitat Shift Of Juvenile Bear Lake Sculpin (Cottus Extensus), James R. Ruzycki May 1995

Ontogenetic Habitat Shift Of Juvenile Bear Lake Sculpin (Cottus Extensus), James R. Ruzycki

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Bear Lake sculpin (Cottus extensus) exhibited an ontogenetic habitat shift during their first year of life. Soon after hatching in the littoral zone, the fry swam to the surface where they dispersed throughout the lake. Most juveniles that initially settled in the profundal zone returned to the littoral zone during their first summer. Patterns in the daily growth increments of otoliths confirmed the history of habitat residence and the individual size at the habitat switch. We used this habitat shift to test a μ/g model incorporating a growth rate-mortality risk trade-off. A trade-off occurred in the littoral …


Identification Of Dna Markers In Triticum Aestivum-Aegilops Caudata Additions Lines By Randomly Amplified Polymorphic Dna (Rapd) Technology, Ling Wei May 1995

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 …


Alteration Of Key Cytokine Levels By Aflatoxin B1 And T-2 Toxin In Male Cd-1 Mice, Raviprakash R. Dugyala May 1995

Alteration Of Key Cytokine Levels By Aflatoxin B1 And T-2 Toxin In Male Cd-1 Mice, Raviprakash R. Dugyala

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Aflatoxin B1 and T-2 toxin are mycotoxins, which produce their immunotoxic effects by affecting nonspecific and acquired immunity in different species. The mechanisms of their immunotoxicity are still obscure. Cytokines are the key signaling molecules during the immune response. In this study, expression of macrophage-produced cytokines Interleukin-lα (IL-lα), tumor necrosis factor (TNF), and IL-6, and lymphocyte-produced cytokines IL-2, interferon y (IFNy), and IL-3 was measured at the mRNA and protein levels, after in vitro activation with mitogens in AFB1-and T-2-toxin-exposed mice.

Significant changes in the organ weights, especially in the mice exposed to a high dose of …


In Vitro Evaluation Of Anti-Eimeria Tenella, Gamont-Specific, Monoclonal Antibodies And Partial Characterization Of Their Target Antigens, Eric Wilson May 1995

In Vitro Evaluation Of Anti-Eimeria Tenella, Gamont-Specific, Monoclonal Antibodies And Partial Characterization Of Their Target Antigens, Eric Wilson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study represents an effort to interrupt the life cycle of Eimeria tenella, the parasite that causes cecal coccidiosis in chickens, with a panel of 12 gamont-specific monoclonal antibodies (Mabs). To facilitate Mab screening, it was first necessary to develop a cell culture-adapted strain of E. tenella (field strain 80) from primary chicken kidney cells (PCKC) to white Leghorn chickens and back to PCKC. This alternation was repeated through 12 such passages. As a result, we have developed a cell culture-adapted strain of E. tenella that produces over 280% more oocysts in vitro than the original parent strain, and …


Evaluation Of Milk Production In Western Whiteface And Navajo-Churro Ewes, Marla Faye Brindley May 1995

Evaluation Of Milk Production In Western Whiteface And Navajo-Churro Ewes, Marla Faye Brindley

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Western Whiteface and Navajo-Churro Ewes, two types of sheep present in the Intermountain West, were compared for their milk production ability. Amount of milk produced per individual and the group milk composition were analyzed for butterfat, lactose, somatic cell count, protein, calcium, and phosphorous.

Ewes were fed ad libitum alfalfa hay and had access to free-choice grain while in the milking parlor. Lambs were weaned at 35 d of age and removed to another holding area and placed on creep feed . Ewes were milked for 90 d following the weaning of the lambs.

Western Whiteface ewes had a much …


Effects Of Graded Levels Of Dietary Lasalocid On Performance Of Holstein Cows During Early Lactation, Dennis E. Christensen May 1995

Effects Of Graded Levels Of Dietary Lasalocid On Performance Of Holstein Cows During Early Lactation, Dennis E. Christensen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Thirty-six multiparous Holstein cows were assigned to one of three dietary levels of lasalocid· 0, 180, or 360 mg/hd/d in a completely randomized design Cows were assigned to treatments 1 wk postcalving and remained on treatment until 11 wk postcalving Basal diets were composed of ground corn, alfalfa hay, alfalfa haylage, corn silage, and soybean meal, fortified with vitamins and minerals as needed. All ingredients were ground and fed as a total mixed ration Daily rations were fed in two equal portions at 0500 and I 700 h at a rate to allow a 5- 10% refusal. Daily measurements included …


Effects Of Antioxidants On Development Of In Vitro Fertilized Bovine Embryos, Bret L. Anderson May 1995

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 …


Development Of Fluorescent In Situ Hybridization Techniques For Physical Mapping In Ovis Aries, Eleanor P. Jenson May 1995

Development Of Fluorescent In Situ Hybridization Techniques For Physical Mapping In Ovis Aries, Eleanor P. Jenson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Genome maps provide information used to identify economic trait loci and loci proximal to genes affecting economically important traits. This research contributes to the development of the ovine genome map by establishing ovine tissue culture techniques and fluorescent in situ hybridization techniques in this laboratory. In addition, a karyotype for sheep affected with spider lamb syndrome was developed. Ovine tissue culture techniques were established using fibroblasts grown from primary explants of sheep and modified cytogenetic procedures. Metaphase chromosomes were obtained from the fibroblast cultures and used for fluorescent in situ hybridization and for banding procedures to develop the spider lamb …


The Effects Of Feeding Chelated Metal Proteinates On Milk Production And Reproductive Performance In Holstein Dairy Cows, Ben James Hardcastle May 1995

The Effects Of Feeding Chelated Metal Proteinates On Milk Production And Reproductive Performance In Holstein Dairy Cows, Ben James Hardcastle

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Twenty-two primiparous Holstein heifers were allocated to one of two treatments. Treatments consisted of: 1) basal ration plus 226.8 g inorganic mineral supplement (control); and 2) basal ration plus 226.8 g inorganic mineral and metal proteinate supplement (50:50). Individual heifer performance was measured during the final 10 weeks of the prepartum period. Feed intake and refusals were recorded daily. Individual heifer body weights recorded weekly did not differ significantly. Blood samples taken at 4-week intervals did not differ in plasma concentration between treatments. Calf birth weights for control heifers were not significantly higher than calves from the treatment heifers.

The …


Use Of Recombinant Human Granulocyte Colony Stimulating Factor As An Adjunct In Antifungal Chemotherapy In Various Animal Model Systems, Lindi Farrell May 1995

Use Of Recombinant Human Granulocyte Colony Stimulating Factor As An Adjunct In Antifungal Chemotherapy In Various Animal Model Systems, Lindi Farrell

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The growing neutropenic patient population provides an ideal target for opportunistic fungal infections. Several effective antifungal drugs are toxic at high doses and contraindicated for long-term treatment. Recombinant human granulocyte colony stimulating factor (rhG-CSF) has been shown to increase neutrophilic numbers and functions, thus providing enhanced host defense. Improved efficacy by using rhG-CSF in conjunction with various antifungal agents was the primary focus of these studies. Use of rhG-CSF in a murine model of vaginal candidiasis did not reduce vaginal colony counts, or improve vaginal histophathology scores. Administration of rhG-CSF in a murine model of pulmonary aspergillosis improved survival, clinical …


Membrane Protein As A Basis Of Nacl Tolerance In Alfalfa, Husni N. Sabah May 1995

Membrane Protein As A Basis Of Nacl Tolerance In Alfalfa, Husni N. Sabah

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study sought to determine whether NaCl altered the plasma membrane proteins in alfalfa exhibiting differential NaCl concentrations, and whether CaSO4 modified the responses. Two alfalfa cultivars, Centurion and Condor, were grown in 0.5 strength Hoagland solution in a greenhouse. The cultivars were exposed to 0, 88, and 132 mM of NaCl alone and mixed with CaSO4 ⋅ H2O at 7 and 14 Mm CaSO4 for 3, 9, and 60 days.

In experiment 1, roots were dried to determine their Na, Ca, K, and Mg concentration. The results were similar to previous reports in which …


Cytological And Molecular Analyses Of The Ns Genome In Russian Wildrye, Psathyrostachys Juncea (Fisch.), Junzhi Wei May 1995

Cytological And Molecular Analyses Of The Ns Genome In Russian Wildrye, Psathyrostachys Juncea (Fisch.), Junzhi Wei

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Russian wildrye (Psathyrostachys juncea Fisch. 2n=2x=14, NsNs) is an important forage grass and a potentially useful germplasm in wheat improvement. A standard C-banding karyotype of Ps. juncea has been developed based on the C-bands of chromosomes in geographically diverse materials. Although there are C-banding polymorph isms, the seven pairs of chromosomes can be distinguished from each other according to their basic banding patterns. Based on C-banded karyotype, one deletion-translocation heterozygote, four primary trisomies, one double-deletion trisomic, and two tertiary trisomies were identified. These cytogenetic stocks will be useful in genetic studies of Russian wildrye.

Genetic variations in Russian wildrye were …


Fire Occurrence, Behavior And The Effect Of Fire On Deer Mouse Density In Oakbrush At Camp Williams National Guard Base, Utah, Joel E. Godfrey May 1995

Fire Occurrence, Behavior And The Effect Of Fire On Deer Mouse Density In Oakbrush At Camp Williams National Guard Base, Utah, Joel E. Godfrey

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Fire occurrence and behavior were determined by collecting and analyzing fuel, weather, and fire history data. Fuel plots were used to measure average fuel loading by vegetation type and integrated with weather to make worst-case fire behavior predictions. A fire history was developed using oakbrush (Quercus gambelli Nutt.) sprouts to determine age and the Global Positioning System (GPS) for mapping the burned areas. Average fuel loading was highest in the oakbrush fuel type with 16.8 t/ha, then juniper (Juniperus osteosperma Torrey) with 6.72 t/ha, and the lowest was in sagebrush (Artemisia tridentata Nutt.) with 4.93 t/ha. Fire behavior predictions were …


Classification Of Vegetation And Analysis Of Its Recent Trends At Camp Williams, Utah Using Remote Sensing And Geographic Information System Techniques, Thomas G. Van Niel May 1995

Classification Of Vegetation And Analysis Of Its Recent Trends At Camp Williams, Utah Using Remote Sensing And Geographic Information System Techniques, Thomas G. Van Niel

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Current vegetation classes were generated from remotely sensed data to provide coarse-level information for an ecosystem management plan developed at Camp Williams, Utah. Vegetation trend from 1973 - 1993 was also examined via satellite imagery. The data set consisted of Landsat Multispectral Scanner (MSS) and Thematic Mapper (TM) images from July or August of 1973, 1975, 1980, 1988, and 1993.

Two approaches were used to detect vegetation change. The first approach determined overall and cover type trend from standard digital image differencing of soil-adjusted vegetation index (SAVI) images. The second approach used an unsupervised classification of a composite SAVI image …


Evaluation Of Wildlife Depredation At Fish Hatcheries In The Intermountain West, William C. Pitt May 1995

Evaluation Of Wildlife Depredation At Fish Hatcheries In The Intermountain West, William C. Pitt

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

During 1993- 1994, I investigated wildlife depredation at Intermountain West fish hatcheries to quantify losses, determined the reliability of bioenergetics models and hatchery manager perceptions to predict losses, and investigated the effectiveness of simple control measures. I observed predators and surveyed managers to quantify the extent of depredation losses and to identify the species responsible. Great blue herons (Ardea herodias), black-crowned night herons (Nycticorax nycticorax), ospreys (Pandion haliaetus), and California gulls (Larus californicus) were the most significant predators of hatchery fish in the field study, and were perceived as such by hatchery …


Improved Control Of Cheese Manufacture Through Continuous Vat Monitoring Of Coagulation Parameters Using The Hot Wire Method, Michael John Lefevre May 1995

Improved Control Of Cheese Manufacture Through Continuous Vat Monitoring Of Coagulation Parameters Using The Hot Wire Method, Michael John Lefevre

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The hot wire method, with pH and temperature sensors, was evaluated to determine its usefulness and application for cheese production automation. Coagulation of milk substrate was measured with the hot wire instrument and by four other methods: Formagraph, Brookfield®, vixcometer, Omnispec™ bioactivity monitor, and Sommer and Matsen rolling bottle method. The hot wire, using the time at maximum slope, detected coagulation before methods that measure resistance to shear, and after methods that measure light reflectance. Coagulation time was not significantly different from the industry standard rolling bottle method used by Sommer and Matsen. the hot wire instrument was also used …


Assessing The Relative Utility Of Models Of Vegetation Dynamics For The Management Of Sagebrush Steppe Rangelands, Paul E. Hosten May 1995

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 …


Muscle Fiber Types, Dna:Rna:Protein Ratios, And Measures Of Tenderness In Various Muscles Of Normal And Callipyge Lambs, Owen D. Rice May 1995

Muscle Fiber Types, Dna:Rna:Protein Ratios, And Measures Of Tenderness In Various Muscles Of Normal And Callipyge Lambs, Owen D. Rice

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

An inherited muscle hypertrophy in sheep is caused by the callipyge gene (CLPG) located on ovine chromosome 18. It has been suggested that this gene is a single autosomal dominant gene. Animals expressing the callipyge gene show increased muscling in the pelvic and torso regions of the body and, thus, have been given the phenotype- descriptive name callipyge (from Greek calli-beautiful; pyge-buttocks). In this study 21 wether lambs, the offspring of callipyge rams (genotype CLPG /clpg) and normal Rambouillet ewes (genotype clpg/clpg), were used to determine the differences in muscle fiber type percentages, composition, and tenderness between normal …


Winter Habitat Selection By American Marten (Martes Americana) In Newfoundland: Why Old Growth?, Gary S. Drew May 1995

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 …


Metabolism Of Selected Antiviral Agents In Cells Infected With Drug-Resistant And Wild-Type Strains Of Murine Cytomegalovirus, Kevin M. Okleberry May 1995

Metabolism Of Selected Antiviral Agents In Cells Infected With Drug-Resistant And Wild-Type Strains Of Murine Cytomegalovirus, Kevin M. Okleberry

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Resistance of human viral pathogens to various antiviral drugs is a serious medical problem. Two modes of drug resistance in cytomegalovirus infections have been observed, the first being altered (decreased) drug metabolism by the infected cells, and the second reduced sensitivity of the viral deoxyribonucleic acid polymerase enzyme to the active form of the drug. Mice infected with the murine cytomegalovirus have been used extensively as an animal model for the human cytomegalovirus, and drug-resistant strains in this model have been identified. To better understand the mode of drug resistance of the virus, the metabolism of two antiviral drugs, 9-(1,3-dihydroxy-2-propoxymethyl)guanine …


Functional Study Of The Structural Vp6 Protein Of Bluetongue Virus, Emiko Hayama May 1995

Functional Study Of The Structural Vp6 Protein Of Bluetongue Virus, Emiko Hayama

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study was undertaken to investigate the structure-function relationship of VP6 protein of bluetongue virus (BTV) using molecular cloning techniques. VP6 is present in small quantities in BTV and its enzymatic activity and role in the viral replication cycle have not been studied. Since the availability of large amounts of purified VP6 is essential for the analysis of VP6, a BTV-11 S3 gene was cloned into a prokaryotic protein expression system. VP6 protein was expressed in large amounts and purified to near homogeneity. A series of C-terminal and internal deletion mutants of S3 gene was constructed and the truncated VP6 …


Effects Of Homogenization And Ultra-High Temperature Processing On The Properties Of Whole Milk Concentrated By A Multiple-Membrane Separation System, Chien-Ti Chang May 1995

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 …


Effects Of Iron Fortification On Microbiological, Physical, Chemical, And Organoleptic Properties Of Yogurt, Sharareh Hekmat May 1995

Effects Of Iron Fortification On Microbiological, Physical, Chemical, And Organoleptic Properties Of Yogurt, Sharareh Hekmat

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

It has been shown that iron binds strongly to the proteins in milk, and our aim was to determine whether or not this binding was affected by lowering pH in the manufacture of yogurt. Iron-protein complexing was studied using two different techniques. 1) Skim milk was fortified with 10 mg iron/100 ml and the pH of the milk was adjusted to 6.7, 6.2, 5.8, 5.3, 4.5, and 4.0. The milk was fractionated by ultracentrifugation at 52,000 x g for 60 minutes. The pellets and serum were then analyzed for iron, calcium, and phosphorus content by inductively coupled plasma spectroscopy. SDS-PAGE …