UNT Theses and Dissertations - 385 Matching Results

Search Results

An Investigation of Gas Chromatographic Separation of Tastes and Odors Produced by Actinomycetes: It is the purpose of this thesis to evaluate a few selected gas chromatographic materials for the separation of odorants produced by an actinomycete culture under laboratory conditions. Also to compare the results obtained with concentrated solutions of a surface water containing similar odors under natural conditions.
An Investigation of Methods for the Concentration of Chemical Compounds Produced by Actinomycetes and Their Relation to Tastes and Odors in Municipal Water Supplies: It is the purpose of this investigation to improve upon techniques to enhance the taste of municipal water and attempt to devise one that could desorb the compounds from carbon in an unaltered state. It was decided that the odor character would be the criterion used to decide if the eluted compounds were the same as those in the raw water.
An Investigation of Microbial Antagonism in Ten Denton County, Texas Soils: This thesis is concerned primarily with the growth and detection of soil microorganisms in ten Denton County, Texas, soils antagonistic to a specific gram-positive and a specific gram-negative bacterial organism.
An Investigation of Naturally Occurring Tastes and Odors from Fresh Waters: The Problem of the cause and control of tastes and odors in water supplies has been the subject of a great many investigations during the last half-century; however, many questions in this field remain to be answered. Theories relating to the cause of tastes and odors occurring in water are still rather numerous and, at present, only a few of them are compatible. Although several procedures have been employed for the eradication of tastes and odors from water supplies, none of them are completely successful.
Investigation of Pyrimidine Salvage Pathways to Categorize Indigenous Soil Bacteria of Agricultural and Medical Importance and Analysis of the Pyrimidine Biosynthetic Pathway's Enzyme Properties for Correlating Cell Morphology to Function in All Phases of Growth: This dissertation comprises three parts and is presented in two chapters. Chapter 1 concerns Arthrobacter, a bacterium with an intriguing growth cycle. Whereas most bacteria exist as either a rod or coccus, this bacterium shares the rod/coccus lifestyle. It therefore seemed important to examine the growth regulatory pathways from the rod and coccus. The committed step, that catalyzed by aspartate transcarbamoylase (ATCase), in the pyrimidine biosynthetic pathway was chosen. The ATCase in Arthrobacter is like the well known Pseudomonas enzyme except that it has an active dihydroorotase (DHOase) associated. Included in Chapter 1 is the description of a microorganism, Burkholderia cepacia, whose ATCase has characteristics that are at once reminiscent of bacteria, mammals, and fungi. It differs in size or aggregation based on environmental conditions. In addition, it has an active DHOase associated with the ATCase, like Arthrobacter. B. cepacia is important both medically and for bioremediation. Since B. cepacia is resistant to most antibiotics, its unique ATCase is a prime target for inhibition. Whereas the first chapter deals with the de novo pathway to making pyrimidines, which is found mainly in the lag and log phase, Chapter 2 addresses the salvage pathway, which comes more into play during the stationary phase. This section focuses on the isolation, identification, and grouping of a number of natural soil bacteria from various soil locations. These organisms are important agriculturally, medically, and industrially. Addition of these soil isolates to poor soils has been found to improve the soil. In a previous study by D.A. Beck, the salvage schemes for a number of laboratory strains of microorganisms were determined. Nine separate classes of salvage were designated by determining the salvage enzymes present. In this study emphasis has been placed on soil bacteria, which had not previously been analyzed. A number of species of soil …
An Investigation of Selected Factors Related to the Professional Status of the Science Teachers in the Four-Year Accredited High Schools of Texas for the School Year 1952-1953: The purpose of this study is to gather information related to the professional status of the science teachers in the four-year accredited high schools of Texas for the school year 1952-1953. The principal concern of the study is "Who is teaching science?"
Investigations of neuronal network responses to electrical stimulation in murine spinal cultures.: Spontaneous activity in neuronal networks in vitro is common and has been well documented. However, alteration of spontaneous activity in such networks via conditioning electrical stimulation has received much less experimental attention. Two different patterns of electrical stimulation were used to enhance or depress the level of spontaneous activity in spinal cord cultures. High-frequency stimulation (HFS), a method routinely shown to increase the efficacy of synaptic transmission, was employed to augment spontaneous activity. Low-frequency stimulation (LFS), the technique often applied to depress synaptic efficacy, was employed to decrease spontaneous activity. In addition, LFS was used to reverse the effect of HFS on spontaneous activity. Likewise, HFS was applied to counter the effect of LFS. Because these networks were grown on multi-microelectrode plates (MMEPs), this allowed the simultaneous stimulation of any combination of the 64 electrodes in the array. Thus, the possible differences in response to single versus multi-electrode stimulation were also addressed. Finally, test-pulses were delivered before and after the conditioning stimulation on the same stimulation electrode(s) in order to assess the change in mean evoked action potentials (MEAPs). Dissociated spinal tissue from embryonic mice was allowed to mature into self-organized networks that exhibited spontaneous bursting activity after two weeks of incubation. Spontaneous activity was monitored from up to 14 recording channels simultaneously. Although uniform responses to stimulation across all recording electrodes were rarely observed, a large majority of the recording channels had similar responses. Spontaneous activity was increased in 52% of 89 HFS trials, whereas activity was decreased in 35% of 75 LFS trials. The duration of most of these increases was less than 5 minutes. When there were substantial and long-term (> 15 min) changes in spontaneous activity, the opposing stimulation pattern successfully reversed the effect of the previous stimulation. The percent change in MEAPs following conditioning stimulation …
The Isolation and Characterization of a Hitherto Undescribed Gram-Negative Bacterium: A unique undosciribed gramnegative rod is extensively characterized in this study. The cells of this unusual water isolate measure 1.2 X 6.5 microns, The most distinguishing characteristic of the bacterium is a polar tuft of 35-40 flagella that aggregate to function as a single organelle which is visible under phase contrast. Aging cells deposit poly- -hydroxybutyric acid granules which are bound by an inclusion membrane made up of four distinct layers. It also possesses an unusual exterior membrane outside the cell wall which contains large fibrils of protein running at a slight angle to the longitudinal axis of the cell. The guanosine-cytosine ratio was found to be 62.2$. The organism's taxonomic position was further investigated by immunological, morphological, and biochemical methods. It was found to be most closely akin to members of the genus Pseudo onas, although somewhat divergent from other species classified in this genus. After careful evaluation of the findings obtained during this study, the new bacterium was subsequently named Pseudomonas multiflagella.
Isolation and Identification of an Odor Compound Produced by a Selected Aquatic Actinomycete: The purpose of this study was to develop an efficient method for the concentration of specific volatile taste and odor compounds produced by a selected aquatic actinomycete. A second purpose was to isolate and identify the specific taste and odor compound present in the highest concentration.
Isolation and Identification of Bacterial Species Associated with the Common House Fly and Three Species of Cockroaches: In an attempt to demonstrate the role of insects as possible carriers of pathogenic bacterial organisms this investigation has been concerned with the determination of the microbial population associated both internally and externally with the common house fly and three species of the cockroach.
The Isolation and Identification of Micro-Organisms from Spoons of Public Eating Establishments in Denton, Texas: This investigation deals with the isolation and identification of bacteria found on selected samples of spoons in various eating establishments in the vicinity of Denton, Texas.
Isolation and Partial Characterization of a Bacterium Which Gives Off Filtrable Cells: The present study was on the isolation of a bacterium capable of producing filtrable forms which passed through the 0.45µ filter membrane and regenerated the parental form; the testing of the true filtrability of the isolate; the relationship between growth of the isolate and appearance of filtrability; partial characterization of the isolate and visualization of the elements that passed through the membrane filter with electron microscopy and shadow casting technique.
Isolation and Partial Characterization of Carotenoid Pigments of Mycobacterium Rhodochrous: It was the purpose of this investigation to isolate and characterize the pigments of Mycobacterium rhodochrous by partition behavior, chromatographic data, and absorption spectra. In addition, it was the purpose to determine whether or not the type of pigments found in M. rhodochrous is typical of those found in other mycobacteria.
Isolation and Partial Characterization of Pigment Mutants of Corynebacterium poinsettie ATCC 9682: Carotenoid pigments were extracted from Corynebacteriuma poinsettiae (wild type) ATCC 9682, and from 108 mutants obtained by exposure of a streptomycin resistant strain of C. poinsettiae to ultra-violet light irradiation and N-methyl- N'-nitro-N-nitrosoguanidine. The pigments were characterized by their absorption maxima, Rf-values, and partition ratios in petroleum ether and methanol. Thin layer chromatography was used to compare pigments of the wild type with those of the mutants. Possible biosynthetic pathways in carotenoid synthesis of the wild type were postulated on the basis of the observed genetic blocks. Mutants were found which suggested the existence of a linear pathway in carotenoid synthesis from the aliphatic C4 0 molecule to the bi-cyclic C50-diol. Other mutants suggested possible alternative pathways in the biosynthesis of these pigments or the presence of intermediates not detectable by thin layer chromatography.
The Isolation, Cultivation and Testing of Organisms Anatagonistic to a Streptomycin Resistant Strain of Pseudomonas Aeruginosa: The problem of finding an efficient antibiotic against Pseudomonas aeruginosa which can be used in the clinical treatment of genito-urinary tract infections resistant to treatment by streptomycin has not yet been solved. Therefore, this problem has consisted of first, the acquisition of possible inhibitors of the streptomycin resistant strain of Pseudomonas aeruginosa; second, the selection and identification of those which show a marked antagonism toward this organism; third, the determination of the antibiotic spectra of the inhibitors; fourth, the determination of whether the streptomycin resistant strain could also acquire a resistance to the antibiotic produced by its inhibitors; and last, an attempt to evaluate the therapeutic possibilities of the antibiotics demonstrated.
Isolation, Identification and Cultivation of Four Phytopathogenic Fungi: This investigation includes a morphological and cultural study of four rather common pathogenic fungi one of which attacks Zinnia elegans, one Lagerstroemia indica, one Ligustrum lodense and one Euonymus japonica. The problem includes, first, a determination of the genera of these four fungi as revealed by their morphology in natural habitat; second, a determination of the growth and cultural characteristics of these on Cornmeal, Potato, Bean, Prune and Carrot agars; third, a comparison of the growth and cultural characteristics of these in natural habitat with the same on the various agars used; and fourth, an evaluation of the five artificial culture media in so far as their usage is concerned in the growth and cultivation of these four species of fungi.
Isolation, Purification, and Characterization of Aldolase from Human Heart: Aldolase from human heart has been purified 128-fold to a final specific activity of 11.52 units per mg. The purification procedure employed column chromatography on phosphocellulose.
Lactate Dehydrogenase of Hymenolepis Diminuta: Isolation and Characterization: Lactate dehydrogenase was isolated in pure form from crude extract of the cestode Hymenoleois diminuta by heat treatment and column chromatography. The purified enzyme has a specific activity of 106 units per mg protein. The molecular weight of the purified protein was 75,000 as determined by Sephadex gel filtration and analytical ultracentrifugation. An equilibrium ultracentrifugation study suggests a subunit molecular weight of 39,000. From these data, a dimer form of the native enzyme is proposed.
Landscape Ecological Characteristics of Habitat of the Red-cockaded Woodpecker: Geographic information systems (GIS) technology was used to analyze factors influencing habitat use by an endangered species, the red-cockaded woodpecker. The study area was the western part of the Raven Ranger District of the Sam Houston National Forest, Texas. The factors considered included both structural characteristics and spatial relationships among stands of trees in the habitat.
The Life Cylce of an Aquatic Actinomycete: The purpose of this investigation was an attempt to clarify the relatives taxonomic position of and to formulate some of the basic cyclic morphological and physiological processes occurring in an aquatic actinomycete possessing streptomycetal characteristics.
Life History Allocation of Energy to Growth and Reproduction in Gizzard Shad, Dorosoma cepedianum, in North Central Texas: Life history allocation of energy to growth and reproduction was determined for female gizzard shad. Absolute caloric energy allocated to eggs increased with age. The relative amount of production energy directed to reproduction increased with age up to 5 years and then decreased. Seasonal variation in lipids was studied. Quantitative changes occurred in ovarian lipids during the reproductive cycle. Carcass lipids varied seasonally. Age of sexual maturity was 3 years. Delayed maturity is attributed to high allocation of energy to growth enabling shad to outgrow intense competition and predation in pre-reproductive ages; there is little competition and predation in reproductive shad. Growth rates and condition factors indicated constant availability of food seasonally.
Life History and Case-building Behavior of Molanna Tryphena Betten (Trichoptera: Molannidae) in Two East Texas Spring-fed Streams: The life history and case-building behavior of Molanna tryphena from two spring-fed tributaries in East Texas were studied from January 1997 to May 1998.
The Life History and Ecology of the Mayfly Neochoroterpes mexicanus Allen (Ephemeroptera: Leptophebiidae): The life history and ecology of Neochoroterpes mexicanus was studied from data collected September, 1971, to August, 1972, and January to December, 1973, in the Brazos River, Texas. Nymphal development, instar analysis, voltinism, standing crops, and production estimates were determined from the quantitative samples taken in 1971 and 1972. Aspects of the life history and food habits of 230 specimens were arrived at from qualitative samples and light box captures in 1973. Laboratory investigation in 1973 helped in establishing instar analysis, egg incubation and description, and first instar descriptions. Neochoroterpes mexicanus appeared to have three generations per year with brood overlap in the summer and fall. It displayed 16 and 19 instars for overwintering and combined summer generations respectively.
The Life History and Ecology of the Stonefly Neoperla clymene (Newman) (Plecoptera: Perlidae): The objective of this investigation was to provide new and more detailed information on the life history and ecology of Neoperla clymene, through an intensive study of the species in the Brazos River, Texas.
Light and Electron Microscope Studies on the Chemotherapeutic Effect of a Combination of Dimethyl Sulfoxide and Hematoxylin on a Transplantable Lymphosarcoma: Investigations concerning the cellular response of tumor tissue to treatment with dimethyl sulfoxide and hematoxylin have not been reported. To establish the response of neoplastic tissue and cells to this combination of agents, this study was undertaken to determine the effects of dimethyl sulfoxide and hematoxylin on a transplantable lymphosarcoma in mice.
Light Spectra Distributions in Temperate Conifer-Forest Canopy Gaps, Oregon and in Tropical Cloud-Forest Canopy, Venezuela: Light spectra distributions were measured in two different montane forests: temperate and tropical. Spectral light measurements were made in different sized canopy gaps in the conifer forest at H. J. Andrews Experimental Forest in Oregon, USA. Researchers at Oregon State University created these gaps of 20 m, 30 m, and 50 m in diameter. In the tropical cloud forest, spectral light measurements were made in two plots that were permanently established at La Mucuy Parque Nacional in Venezuela, in collaboration with researchers at Universidad de Los Andes. In both studies, spectra and distributions of physiologically active light were analyzed: red, far-red, R/FR ratio, and blue light.
Liver Glyoxalase Activity in Normal Mice and Mice with Lymphosarcoma: It is the purpose of this investigation to determine the variation of glyoxalase activity in liver of normal mice and in the liver of mice bearing a lymphosarcoma and to compare the glyoxalase activity of the lymphosarcoma with values previously reported in the literature for other tumor types. Further, if there is indeed a variation in liver glyoxalase activity between normal and tumor-bearing mice, it will be compared to the variation in the activity of two other enzymes present in liver tissue in relatively high concentration.
Location of the Carotenoid Pigments of Corynebacterium Species Strain 7E1C: The purpose of this investigation was to determine the site of the carotenoid pigments in C. spp. strain 7E1C as a step towards resolving the role of the pigment in the cell.
The Mechanism of Action of Immune Guinea Pig Serum in Staphylococcus Infection in Mice: It is the aim of this work to study the role, if any, of C'4 in the immune response against Staphylococcus aureus infections.
Metabolism of Hydrocortisone by X-Irradiated Rat Liver Tissue as Determined by the Porter-Silber Chromagen Method: The present study may be considered endocrinological and radiobiological in nature. The endocrinology phase was concerned with studying the changes in endocrine function following the application of a stress agent. X-irradiation was chosen as the stressor in order to determine any difference in effect of this stressor from others which have been studied, e. g. heat, cold, metabolic poisons. Liver slices taken from rats at various time intervals following whole body X-irradiation were tested for their ability to metabolize hydrocortisone from a Krebs-Ringer solution.
Metabolism of Methylglyoxal by Scenedesmus Quadricauda: The purpose of this study was to investigate the metabolic pathways of methylglyoxal in S. quadricauda.
Microbial Activity in "Overland Flow" Industrial Waste Treatment: One of the major problems of modern industries concerns the disposal of waste materials without the concomitant pollution of the environment. Several food and wood products industries have solved this problem by using the "overland flow" method of waste treatment. The research described in this paper was undertaken to ascertain the fact that the waste purification occurring on the disposal field is the result of microbial activities in the soil, and to study the transformations taking place.
A Microbial Survey of Raw Ingredients Used in Finished Products at Kraft Foods Company, Garland, Texas: The purpose of this investigation is to determine through routine checks the number of organisms present in the various raw ingredients used for the preparation of foods. The problem has consisted of, first, a determination of the total bacterial population by numbers; second, a determination of the incidence of colon bacteria in the samples examined; third, a determination of the presence of yeasts and molds; and fourth, an attempt to utilize this information obtained in judging the methods of handling the raw ingredients before they are used in the processing of foods.
Microbial Utilization of a Certain Hydrocarbon Insecticide: This problem includes, first, the isolation and identification of microorganisms which utilized the hydrocarbon insecticide as a sole source of carbon and energy; second, a determination of the effect on plants sprayed with the hydrocarbon medium as compared with the effect on plants sprayed with the hydrocarbon medium containing a good growth of hydrocarbon-utilizers; and third, a determination of the ability of laboratory stock cultures of organisms to utilize or remain alive in the hydrocarbon medium.
Microbiotic Cycles in Lake Hefner: The purposes of this paper are 1) to determine the microbiotic cycles which occur in Lake Hefner in order to form a basis for ascertaining the effects of future additions of evaporation control chemicals on the biological life of this reservoir, and 2) to make a generalization as to the microbiotic cycles which might occur in Southwestern reservoirs.
Microflora Found in a Selected Group of Food Products Enclosed in a Protective Wrapper: The purposes of this study are, first, to determine relative numbers and predominant types of bacterial organisms in the various food products studied; second, to evaluate the efficiency of the paper coverings of these foods; and third, to determine whether these products are potential sources of food poisoning.
Microflora in Prepared Foods Dispensed from Eating Establishments in Dallas, Texas: A bacteriological study was made of a number of prepared foods that were bought ready-to-eat, for home consumption, from several food establishments in Dallas, Texas. The purpose of this study was to show whether these foods could be a potential source of food poisoning; whether there are any particular foods that should have greater care than others in order to protect their quality; and whether the bacteriological contamination could have been prevented by strict observance of the city regulations for handling foods.
Microflora of Frozen Fruits and Vegetables Dispensed from Grocery Stores in Denton, Texas: This investigation was carried out in order to determine whether or not blanching and freezing tends to reduce the incidence of bacteria, particularly those of the coliform group, and also the yeasts and molds.
Microorganisms Associated with a Spray Irrigation System: The area of research for this thesis concerns the role played by microorganisms in the process of organic breakdown of waste effluent. Although considerable research has been done since the early 1950's, little consideration has been given to the role of the microorganisms in this type of waste water purification.
Moisture Relations of the Soils of Denton County: In this research, study was made of representative soils of denton County (Texas) with the aim of correlating various soil-moisture factors through experimental analyses. Two accepted hypotheses of soil-moisture relations have been substantiated by experiment with Denton County soils.
Molecular Cloning and Functional Analysis of Transposable Mercury Resistance Genes Encoded by the OCT Plasmid: Translocation of a 17.1 kilobase region of the OCT plasmid encoding mercury resistance (mer) in Pseudomonas putida was shown to occur in a recombination-deficient host with plasmid PP1 serving as a recipient replicon. The frequency of transposition in Pseudomonas was estimated at 10^3 -10 -^2, but undetectable in Escherichia soli. ' DNA comprising all of mr as well as subregions there of were cloned and subjected to DNA sequence analysis. Like other transposons, mer was found to contain inverted repeat sequences at its termini. These were similar to, but not identical to the inverted repeat structures found in the prototypical mercury resistance transposon Tn501 from E. aeruginosa.
Morphological and Physiological Changes in Micrococcus Pyogenes Var. Aureus during Development of its Resistance to Terramycin: The problem in this investigation consists of, first, the procurement of several strains of Micrococcus pyogenes var. aureus; second, the comparison of the degree and rate of development of resistance of these organisms to terramycin; and, third, to study the morphological and physiological changes which occur during the development of resistance.
A Multiphasic Study of the Interaction Between the Branchiobdellid Cambarincola Vitrea and its Crayfish Host Procambarus Simulans: The host-parasite interface between the branchiobdellid Cambarincola vitrea Ellis and its crayfish host is investigated along ecological, ultrastructural, serological, and endocrinological lines of evidence. Monthly analysis of a natural branchiobdellid from a vernal habitat demonstrates the annelid to be particularly sensitive to changes involving both the physical habitat as well as the host crayfish.
Mutagenic Potential of Tetramethylthiuram Disulfide (42-S Thiram) on the Germ Cell Stages of Drosophila melanogaster: Tetramethylthiuram disulfide (42-S Thiram), a carbamate fungicide was studied for its mutagenic potential on the germ cell stages of wild-type male Drosophila melanogaster. The mutagenicity was tested using the sex-linked recessive lethal assay (SLRL). Any lethals induced in the F2 generation were evidenced by the absence of wild-type males. Although there was an increase in mutation rates in the 42-S Thiram treated wild-type males over the control wild-type males, it was not significantly higher. According to the laboratory conditions in this preliminary study, tetramethylthiuram disulfide failed to produce mutagenic effect.
Newer Methods of Removing Taste and Odor Compounds from Water Supplies: This thesis discusses the causes and methods for removing taste and odor compounds from water supplies.
Nitrogen Accretion on a Lacustrine Plain: The purpose of the investigation was to locate the plant population which had the greatest impact on soil nitrogen in a successional sequence from newly deposited alluvia to a mature streamside forest, and to evaluate the pioneer populations in terms of their annual nitrogen contribution.
Nutritional Requirements of Corynebacterium poinsettiae: In a minimal medium supplemented with glucose and yeast extract, the optimum pH for the growth of C. poinsettias was found to be 7.5. The organism requires thiamine, biotin, and pantothenic acid for growth. No absolute requirement was found for any amino acid, purine or pyrimidine although an amino acid mixture was stimulatory. Casamino acids could be substituted for the synthetic amino acid mixture. Yeast extract provided an additional factor(s) necessary for maximal growth. The results suggest that the unknown factor found in yeast extract might be purified by a combination of solvent extraction, and adsorption and elution from charcoal.
Observations on the Life History of the Brown Spider, Loxosceles Reclusa Gertsch and Muliak: This research was undertaken primarily to further elucidate the life history of this medically important spider. Special attention was given to rearing experimental spiders under as near-natural environmental conditions as possible.
Odorous Metabolite and Other Selected Studies of Cyanophyta: The purpose of this study was as follows: 1. Elucidate the laboratory conditions under which Anabaena circinalis produces the noxious odor component or components in maximum concentration, 2. Isolate the major noxious odorous metabolite(s), 3. Structurally define the odorous metabolite(s), 4. Quantitate the amount of metabolite(s) that a given amount of the organism produced.
Opthalmic Use Of Sodium Cephalothin: An In Vivo Comparison: A rabbit keratoconjunctivities model was used to evaluate ophthalmic formulations containing 1 percent sodium cephalothin in silicon oil, a 1 percent sodium cephalothin aqueous solution, and a 0.3 percent gentamicin sulfate solution. Rabit eyes were inoculated intracorneally with Pseudomonas aeruginosa, Staphylococcus aureus, or Streptococcus pneumoniae, After topical treatment, none of the antibiotic formulations were effective in the P. aeruginosa model; all three showed good activity against S. aureus, and against S. pneumoniae, the caphalothin formulations were more effective than gentamicin.In a related stability study, the cephalothin potency of the silicon formulation was maintained for 16 weeks at 4, 25, and 450 C These studies suggest that sodium cephalothin can be formulated as an effective and stable ophthalmic dosage form.

UNT Theses and Dissertations - 385 Matching Results

Search Results

Add Filters

Applied Filters