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  Partner: UNT Libraries
 Department: Department of Biology
 Collection: UNT Theses and Dissertations
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.
Biological Indices of Stream Pollution
A thorough biological survey and evaluation is a lengthy and expensive project. The number of technically trained persons required prevent its use by most public agencies. Since public health departments are the groups most frequently concerned with measuring the effects of pollution in streams, a need exists for a simplified method of sanitary survey. Recognizing this need, the Texas Heal Department assigned the writer the problem of devising a method of survey which would require a field party of two and could be conducted entirely from a mobile field laboratory.
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.
The Incidence of Colon Bacteria on the Hands of North Texas State Teachers College Students
This investigation has for its aim the determination, in a measure, of the degree of personal sanitation existent among students at North Texas State Teachers College, Denton, Texas.
The Relationship of Light Wave Length to Tissue Differentiation in Sunflower Seedlings
The purpose of this study is to determine the relationship of light wave length to tissue differentiation in sunflower seedlings.
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.
Taxonomic Analysis of Marine Actinomycetic Isolates
Though this current study was initiated independently and was not a test laboratory for the taxonomic sub-committee's evaluative program, the problem outlined in this treatise was also designed in an effort to test certain characteristics of the actinomycetes of both a biochemical and morphological nature. This problem employed methods that might absolve or establish certain criteria for taxonomic use in the group of actinomycetes.
Treatment of Akr Mouse Leukemia with Specific Rabbit and Mouse Antiserum
This work is concerned with a study of the role of complement and antibodies in the serum of rabbits and of a non-susceptible strain of mice in the protection of Akr mice injected with active Akr tumor cells.
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.
The Effects of Heparin on the Development of Resistance to Antibiotics by Staphylococcus Aureus
Since heparin combines with some antibiotics to decrease the toxicity of the antibiotic to the patien, the purpose of this investigation is to determine whether it has any effect upon the development of resistance to antibiotics by Staphylococcus aureus.
Studies on the Nutrition of Rhodospirillum Rubrum
The purpose of this study has been to examine the nutritional requirements of Rhodospirillum rubrum and, on the basis of the results, develop a culture medium which could be use to promote more rapid and abundant growth facilitating the laboratory cultivation and observations of the properties so exhibited.
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.
The Seasonal Cycle in the Testis of the Large-Mouthed Black Bass, Huro Salmoides, (Lacepede)
Study to determine the seasonal changes in histological and cytological structures in the testis of Huro Salmoides (Lacepede), the large-mouthed black bass.
Chemical and Physiological Properties of an Antibiotic Produced by a Variant of the Penicillium Notatum-Chrysogenum Group
The present study of the production and properties of an antibiotic was undertaken in the hope that some useful information could be contributed to a long-range investigation program being carried on at North Texas State Teachers College. This program is concerned with the production of a useful antibiotic from a variant of the Penicillium notatum-chysogenum group of molds.
The Effect of Repeated Antigen Injections on the C' and C'4 Titers in Guinea Pig Serum
In this study the effects of repeated antigen injections on total complement (C') and C'4 of guinea pig serum were investigated to determine if constant antigenic stimulation would show changes in the C' and C'4 titers. Attempts were also made to correlate any changes with variations in antibody titers during the repeated antigen injections.
The Effect of Avidin Injected Intraperitoneally on the Course of Leukemia in the Mouse
The current work was undertaken to test the ability of avidin to affect the course of leukemia when administered intraperitoneally.
Relation of Dosage of Antiserum to Protection in Mouse Leukemia
It is the purpose of this paper to attempt to confirm the work of Schlagenhauf and Ingebrigsten and to show the effects of repeated injections of guinea pig serum immunized with various strains of mouse leukemia.
Colonial Variations of a Mucoid Strain of Staphylococcus Aureus
It was the purpose of the present investigation to demonstrate the selection of a variant of one strain of Staphylococcus aureus by altering certain environmental factors, and to study that variant as to biochemical activities and capsule formation.
Ecotoxicological Investigations in Effluent-Dominated Stream Mesocosms
The University of North Texas Stream Research Facility (UNTSRF) was designed to examine contaminant impacts on effluent-dominated stream ecosystems. Stream mesocosms, fed municipal effluent from the City of Denton, TX, Pecan Creek Water Reclamation Plant (PCWRP), were treated with 0, 15 or 140 µg/L cadmium for a 10-day study in August 2000. Laboratory toxicity test and stream macroinvertebrate responses indicated that cadmium bioavailability was reduced by constituents of effluent-dominated streams. The Biotic Ligand Model (BLM) for Cd was used to predict a 48 hour Cd EC50 for Ceriodaphnia dubia of 280 µg/L in these effluent-dominated streams. This value is higher that an EC50 of 38.3 µg/L Cd and a 7-day reproduction effect level of 3.3 µg/L Cd generated for C. dubia in reconstituted laboratory hard water. These results support use of a cadmium BLM for establishing site-specific acute water quality criteria in effluent-dominated streams. Although not affected by 15 µg/L treatments, organisms accumulated Cd in 15 µg/L treated streams. Hence, over longer exposure periods, Cd accumulation may increase and a no effect level may be lower than the observed 10-day no effect level of 15 µg/L. A toxicity identification evaluation procedure was utilized with in vitro and in vivo bioassays to identify estrogenic compounds in PCWRP effluent, previously identified to seasonally induce vitellogenin (VTG) in male fathead minnows. Steroids, nonylphenol ethoxylate metabolites, and other unidentified compounds were identified as causative effluent estrogens. These findings suggest that in vivo VTG bioassays should be used to confirm in vitro Yeast Estrogen Screening assay activity when effluents are fractionated or screened for estrogenicity. A subsequent 90-day cadmium study was initiated to assess long-term effluent and cadmium effects on fish endocrine function. Juvenile fathead minnows were placed in UNTSRF pool sections of replicate streams treated with 0, 5, 20 or 80 µg/L Cd. Male VTG was induced at each treatment level, indicating that PCWRP effluent was estrogenic during fall 2001. 20 and 80 µg/L Cd treatments reduced male circulating estradiol levels and critical swimming performance. Future studies are needed to assess impacts of environmental estrogen exposure on fish calcium metabolism and vertebral integrity.
The Effects of Media Constituents Upon the Growth and Pigment Production of Micrococcus Flavus, Micrococcus Roseus, Micrococcus Subcitreus, and Sarcina Citrea
This investigation has for its aim the explanation of growth and pigment production of Micrococcus flavus, Micrococcus roseus, Micrococcus subvitreus, and Sarcina citrea by the addition of various nutrient test materials to a standard culture medium.
The Vegetation of the Austin Chalk Formation of Collin County, Texas
No Description
The Effect of Short Term Immobilization and Drug Induced Muscle Atony on the Blood and Urine Chemistry of Dogs
This thesis investigates immobilization and its complications in dogs.
The Effect of Media Constituents on Growth and Pigment Production of Mycobacterium Phlei, Pseudomonas Fluorescens, Pseudomonas Aeruginosa, and Staphylococcus Citreus
Little is known concerning the production and significance of bacterial pigments. There is seemingly an open field for studying the effects produced by varying the nutritive content of culture media upon which organisms are grown. This has led to an especial interest in, and the purpose of this investigation.
The Effects of Selected Algicides and Some Coordination Complexes upon the Apparent Photosynthesis of Chlorella Pyrenoidosa
Many experiments have been performed with the Warburg apparatus, or variations of this manometric technique, since Warburg's experiments (52, 53) where the effects of cyanides upon dark reactions and of urethanes upon light reactions of photosynthesis were demonstrated. The same basic techniques were utilized in this research in attempting to determine the effects of some coordination complexes upon the apparent photosynthetic rate of Chlorella pyrenoidosa. A second goal of the present paper was to investigate the potential of the Warburg apparatus as a tool for screening algicidal compounds.
Pressure-Flow Relationships in the Isolated Cerebral Circulation of the Dog
The purpose of this investigation is to determine the pressure-flow relationships in the isolated canine cerebral vascular bed. These relationships in vessels which supply an organ surrounded by bone are theoretically influenced by limiting factors which are not present in those vessels surrounded by soft tissue. An evaluation of the extent of these limitations is essential to thorough understanding of the dynamics of the cerebral vascular bed.
Bacterial Survey of Representative Denton County Wells with Special Reference to Sanitation
This thesis aimed to study the seventy-two representative wells of Denton County and to determine the possibilities of infection with typhoid organism. The sanitary survey and the test for Colon-Aerogenes bacteria show that 55% of the 72 wells studied are unsanitary, 27% are sanitary, and 18% are doubtful.
A Study of the Phytoplankton Population of Lake Dallas
The limnological investigation of any body of water is undertaken in order to secure more accurate information concerning the factors which play an important role in fish production or sanitation. This study shows the qualitative and quantitative planktonic algae in Lake Dallas, for the year 1937-38.
A Correlation of the Habitat Factors with the Quantity of Bacterial Colonies as Observed by the Direct Microscopic Method on Twenty Soils of Denton County, Texas
The aim of this study is to determine what factors are most important in controlling the number of bacterial colonies found in twent represntative Denton County (Texas) soils during the growing season.
The Ecology of Chlorohydra Viridissima in a Small Perennial Pond
The purpose of this study is to determine the influence of chemical, physical, and bilogical factors on th seasonal variation in population and on reproduction of Chlorohydra Viridissima (Schulze) in a small pernnial pond.
A Yearly Study of the Bacterial Flora of Lake Dallas Water with Special Reference to Sanitation
The purpose of this thesis is to determine the relative numbers of colon bacteria in the water of Lake Dallas.
Possible uses of North Texas Plants and Animals in Elementary Science
This thesis aimed to study plants and animals of North Texas which are adaptable for use in elementary science. In this study, 15 groups of plants and animals were selected as representative ones and among other benefits, each group of organisms was examined for its contributions to a limited understanding of bilogical principles.
The Vegetation and Habitat Factors of Red River County, Texas
The aim of this study has been to measure some of the ecological factors in a series of plant habitats and their relation to the existing vegetation in selected twenty soil types of Red River County, Texas.
A Comparative Study of the Bottom Fauna of four Texas Lakes
This thesis attempted to study the bottom productivity both qualitatively and quantitatively with reference to the distribution of bonthos. The study of the bottom fauna in large reservior lakes is a relatively new field. This work will give more information on an unknown field than previously existed, although its scope is not intend to be exhaustive.
Variations in Soil Fungi of Ten Representative Soils of Denton, County, Texas
This study attempted to examine representative soils of Denton County in an effort to determine seasonal and soil type variations in the fungous flora both quantitatively and qualitatively.
A Study of Plankton Dilution in Source Streams Compared with that of Lake Dallas Proper
This study was a comparative study of Plankton of Lake Dallas and the three main source streams. Based on the analysis of data, which was presented relative to the organisms taken from the lake and from the source streams, the results obtained are discussed, the Plankton seem to be largely autogenetic in Lake Dallas, the source streams Elm Fork and Clear Creek form a dilution process.
The Origin of Ova in the Adult Opossum
This study attempted to determine whether ova are formed from the epithelial covering of the ovary during sexual maturity, and if so to determine how they are formed and to see if there is any relation between the formation and the breeding season.
A correlation of the Edaphic Factors with the Vegetation of the Woodbine sands, Denton County, Texas
The purpose of this study was to correlate the Vegetation of the Woodbine Sands with the edaphic factors. In the laboratory an analysis of the edephic factors was made of the twenty-two soil types collected from the three formations. The results of these and other analysis are shown in tables and graphs. The results indicate that the vegetational cover of an area that is uniform in its origin and in its resident soil factors is determined by the edaphic factors present.
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.
Percolation, Capillarity and Chresard of Representative Denton County Soils
This paper deals with a study of the chresard, percolation, and capillarity of twenty representative Denton County soils. The group of soils chosen vary greatly in texture thus affording excellent material for comparative studies of edaphic factors based upon this property.
Studies on the Bacterial Flora of Milk, Ice Cream, and Beverages in Denton, Texas
The purpose of this study is to observe the frequency of occurrance of members of the colon group in various brands of milk, milk products, and soft drinks marketed in the city of Denton, and to determine the total number of bacterial organisms occuring in these products from week to week.
Construction of a Pseudomonas aeruginosa Dihydroorotase Mutant and the Discovery of a Novel Link between Pyrimidine Biosynthetic Intermediates and the Ability to Produce Virulence Factors
The ability to synthesize pyrimidine nucleotides is essential for most organisms. Pyrimidines are required for RNA and DNA synthesis, as well as cell wall synthesis and the metabolism of certain carbohydrates. Recent findings, however, indicate that the pyrimidine biosynthetic pathway and its intermediates maybe more important for bacterial metabolism than originally thought. Maksimova et al., 1994, reported that a P. putida M, pyrimidine auxotroph in the third step of the pathway, dihydroorotase (DHOase), failed to produce the siderophore pyoverdin. We created a PAO1 DHOase pyrimidine auxotroph to determine if this was also true for P. aeruginosa. Creation of this mutant was a two-step process, as P. aeruginosa has two pyrC genes (pyrC and pyrC2), both of which encode active DHOase enzymes. The pyrC gene was inactivated by gene replacement with a truncated form of the gene. Next, the pyrC2 gene was insertionally inactivated with the aacC1 gentamicin resistance gene, isolated from pCGMW. The resulting pyrimidine auxotroph produced significantly less pyoverdin than did the wild type. In addition, the mutant produced 40% less of the phenazine antibiotic, pyocyanin, than did the wild type. As both of these compounds have been reported to be vital to the virulence response of P. aeruginosa, we decided to test the ability of the DHOase mutant strain to produce other virulence factors as well. Here we report that a block in the conversion of carbamoyl aspartate (CAA) to dihydroorotate significantly impairs the ability of P. aeruginosa to affect virulence. We believe that the accumulation of CAA in the cell is the root cause of this observed defect. This research demonstrates a potential role for pyrimidine intermediates in the virulence response of P. aeruginosa and may lead to novel targets for chemotherapy against P. aeruginosa infections.
Phosphorus Retention and Fractionation in Masonry Sand and Light Weight Expanded Shale Used as Substrate in a Subsurface Flow Wetland
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Constructed wetlands are considered an inefficient technology for long-term phosphorus (P) removal. The P retention effectiveness of subsurface wetlands can be improved by using appropriate substrates. The objectives of this study were to: (i) use sorption isotherms to estimate the P sorption capacity of the two materials, masonry sand and light weight expanded shale; (ii) describe dissolved P removal in small (2.7 m3) subsurface flow wetlands; (iii) quantify the forms of P retained by the substrates in the pilot cells; and (iv) use resulting data to assess the technical and economic feasibility of the most promising system to remove P. The P sorption capacity of masonry sand and expanded shale, as determined with Langmuir isotherms, was 60 mg/kg and 971 mg/kg respectively. In the pilot cells receiving secondarily treated wastewater, cells containing expanded shale retained a greater proportion of the incoming P (50.8 percent) than cells containing masonry sand (14.5 percent). After a year of operation, samples were analyzed for total P (TP) and total inorganic P (TIP). Subsamples were fractionated into labile-P, Fe+Al-bound P, humic-P, Ca+Mg-bound P, and residual-P. Means and standard deviations of TP retained by the expanded shale and masonry sand were 349 + 169 and 11.9 + 18.6 mg/kg respectively. The largest forms of P retained by the expanded shale pilot cells were Fe+Al- bound P (108 mg/kg), followed by labile-P (46.7 mg/kg) and humic-P (39.8). Increases in the P forms of masonry sand were greatest in labile-P (7.5 mg/kg). The cost of an expanded shale wetland is within the range of costs conventional technologies for P removal. Accurate cost comparisons are dependent upon expansion capacity of the system under consideration. Materials with a high P sorption capacity also have potential for enhancing P removal in other constructed wetland applications such as stormwater wetlands and wetlands for treating agricultural runoff.
A Physiological Age-Grading System for Female Hydrellia pakistanae Deonier (Diptera: Ephydridae)
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Conflicting opinions about the effectiveness of H. pakistanae as a biological control agent for hydrilla prompt researchers to find a method for assessing the fly's success. Developing a physiological age-grading system for the fly using ovarian morphology to detect changes in reproductive activity is useful for evaluating reproductive status of the fly in field populations. Changes in the appearance of follicular relics in ovaries with oviposition provide a reliable method to estimate fecundity. Characteristics of follicular relics were used to develop a system with eight physiological age classes, three nulliparous and five parous. Changes that occur in the fat body were used to assist in classification of nulliparous females or those with low egg counts.
Assimilation of Inorganic Nitrogen by Aquatic Actinomycetes
It was the purpose of this investigation to present laboratory data concerning the assimilation of inorganic nitrogen by the aquatic actinomycetes. The strains of aquatic actinomycetes under consideration represented a cross section of those currently under culture at North Texas State University.
Some Relationships between Certain Aquatic Actinomycetes and Bacillus Cereus
The purpose of this investigation is to determine if there was a metabolic relationship between the actinomycetes and the gram positive, spore-forming becilli in surface waters, and, if such a relationship was evident, to relate the association to the disappearances of typical actinomycete tastes and odors from waters.
Autoimmunity of Periodontitis
The purpose of this investigation is to determine if auto-antibodies are demonstrable in inflammatory periodontal disease using methods other than those of Novotny.
Effects of X-Irradiation on Water and Ion Flux in Isolated Roots
Due to the relatively small amount of work concerning radiation, it was thought feasible to use ionizing radiation as a tool to study the relationship between water and salt flux in isolated root systems. Moreover, the more quantitative potometric method lends itself well to such a study, since the two processes can be followed simultaneously. the aims of this study, therefore, were 1) to determine effects of X-irradiation on water, calcium and potassium flux in excised onion roots; 2) to determine the dose levels required for producing permeability changes; 3) to investigate the nature of radiation damage to root systems; and 4) to attempt to shed light on the relation between water transport and ion movement in root systems.
Studies of Fungal Antagonism in a Norfolk Fine Sand, Denton County, Texas
This investigation has had for its primary purpose the noting of the incidence of antagonists as occurring in a Denton County, Texas, Norfolk Fine Sand. A further interest has been the determination of the effect of these antagonists upon known beneficial soil organisms.
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.
Identification of Streptomyces Species Using Fluorescent Antibody-Membrane Filter Techniques
It is the purpose of this investigation to modify existing methods in an attempt to provide a rapid identification of members of the genus Streptomyces.