UNT Theses and Dissertations - 857 Matching Results

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In Vitro Determination of the Cellulose-Decomposing Rates of Twelve Denton County, Texas Soils

Description: In this study twelve types of top soil were collected under aseptic conditions. The cellulose-decomposing rates of these were compared in order to determine the relative rates in the cellulose-decomposing potential of the microorganisms involved. Furthermore, this investigation is designed to acquire pertinent information on the rate at which natural cellulose materials are returned to available plant food.
Date: 1950
Creator: Heather, Carl D.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Seasonal Survey of Actinomycetes in Twenty Denton County, Texas, Soils

Description: This investigation has had for its aim a further study of actinomycete flora of twenty Denton County, Texas, soils. The problem has evolved itself into, first, a seasonal analysis for the number of actinomycetes in each of the twenty soils; second, a determination of the types of soils that contain the greatest number of actinomycetes in each cultivated and uncultivated land; third, a determination of soil moisture and pH; and fourth, an attempt to correlate these factors with the number of ac… more
Date: 1949
Creator: Hudgins, Gladys
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Partner: UNT Libraries
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Applications of GIS and Remote Sensing for the Characterization of Habitat for Threatened and Endangered Species

Description: Geographic Information Systems (GIS) and remote sensing technologies were used to identify and describe potential habitat for three species endemic to the Southwestern United States; the Golden-cheeked Warbler (Dendroica chrysoparia), the Black-capped Vireo (Vireo atricapillus), and the Texas kangaroo rat (Dipodomys elator). For each species, the computerized classification of digital satellite imagery was integrated with ancillary spatial information (e.g. soils, geology, and land use) to con… more
Date: December 1989
Creator: Shaw, Denice Marie, 1958-
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Effects of Brain Injury on Primary Cilia of Glial Cells and Pericytes

Description: Glial cells maintain homeostasis that is essential to neuronal function. Injury to the nervous system leads to the activation and proliferation of glial cells and pericytes, which helps to wall off the damaged region and restore homeostatic conditions. Sonic hedgehog is a mitogen which is implicated in injury-induced proliferation of glial cells and pericytes. The mitogenic effects of sonic hedgehog require primary cilia, but the few reports on glial or pericyte primary cilia do not agree about… more
Date: December 2016
Creator: Coronel, Marco V.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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CO2 Transport and Acid-Base Status during Fluctuations in Metabolic Status in Reptiles

Description: Reptiles can often experience perturbations that greatly influence their metabolic status (e.g., temperature, exercise, digestion, and ontogeny). The most common cause of fluctuations in metabolic status in post-embryonic reptiles is arguably digestion and physical activity (which will be further referred to as exercise). The objective of this thesis is to determine the mechanisms involved in CO2 transport during digestion, determine the mechanisms that allow for the maintenance of acid-base ho… more
Date: December 2021
Creator: Conner, Justin Lawrence
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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A Study of Some Congenital Anomalies of the Teeth

Description: Anomalies of the teeth include a variety of expression such as: anodontia, hyperdontia, peg teeth. opalescent dentine, mottled enamel, and other imperfections of the teeth. This paper is concerned primarily with anodontia in human subjects, although other abnormalities of interest are mentioned. Insufficient datum is the principal difficulty encountered in determining the mechanism and means of transmission in human genetics. Small families, slow breeding, and inability to subject humans to exp… more
Date: August 1955
Creator: Jones, Alvin Watt
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Use of Remote Sensing for Cover Type Interpretation Over the Ray Roberts Reservoir Area

Description: As part of a pre-impoundment study for the Ray Roberts Reservoir Area, Landsat-5 multi-spectral scanner (MSS) imagery was used for cover type interpretation. This research was concerned with analysis techniques for MSS images and a comparison of results obtained using computer assisted interpretatin of MSS images and a comparison of results obtained using computer assisted interpretation of MSS images with those obtained using manual interpretation of false color infrared (CIR) photographs.
Date: December 1987
Creator: Cassidy, Kelly Michela
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Investigations on Abundance, Habits, and Distribution of Amphibians and Reptiles of Denton County, Texas

Description: The purpose of the present study of the herpetofauna was to obtain additional information regarding the vertebrates of Denton County, and to produce a well-preserved, cataloged collection of the amphibians and reptiles for the Museum of Zoology, North Texas State University. An understanding of the vertebrate life of the county also involves an investigation of the habitats within the county that may, in part, count for the distribution of these animals. It is well recognized that the environme… more
Date: January 1967
Creator: Telfair, Raymond Clark
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Immunofluorescence as a Method for the Rapid Identification of Streptococcus Faecalis in Water

Description: The development and refinement of FA has been adequately investigated with major emphasis on pathogenic microorganisms. The development of this technique has reduced both the time and number of biochemical tests necessary to identify a diversity of organisms. The organisms included are the protozoans, as described by Goldman (1953 and 1957) and by Ingram (1961), viruses, as reported by Liu (1955a) and Burgdorfer and Lackman (1960a), pathogenic bacteria which have been investigated by Moody, Gol… more
Date: August 1970
Creator: Abshire, Robert Louis
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Partner: UNT Libraries
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Fumarase From Ascaris Suum: Partial Purification and Characterization

Description: One molecular form of fumarase from Ascaris suum was demonstrated by cellulose acetate electroporesis and isoelectric focusing. The enzyme was partially purified by ammonium sulfate fractionation and ion-exchange chromatography to a specific activity of 49 units per mg protein. Enzymatic assay of the partially purified by ammonium sulfate fractionation amd ion-exchange chromatography to a specific activity of 49 units per mg protein. Enzymatic assay of the partially purified preparation showed… more
Date: May 1976
Creator: Powley, David G.
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Protein Profiles of Azotobacter Vinelandii During the Encystment Process

Description: Azotobacter vinelandii 12837 was grown in Burk's glucose media and transferred onto Burk's n-butanol agar plates to allow for the formation of cysts. The patterns of the vegetative cell proteins were compared for each successive day of cyst formation, using the polyacrylamide gel isoelectric focusing technique. The findings revealed that, as the cysts developed to maturity, definite changes occurred in the protein constitution, indicative of the biochemical and physiological changes which cells… more
Date: August 1977
Creator: Butler, Mark A.
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Partner: UNT Libraries
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Relationship of Certain Fungi to Azotobacter in Nitrogen-Free Media

Description: Azotobacter and various fungi were grown together in nitrogen-free media. Maximal fungal growth in the medium used was possible only at the expense of Azotobacter cells and growth was always accompanied by acid production. When the medium reached a pH of 2, the bacterial cells were aggregated on fungal hyphae and the culture fluid appeared to be free of Azotobacter. Aspergillus niger grew well at the expense of viable bacteria and other fungi grew well on heat-killed cells of A. vinelandii. Mem… more
Date: August 1976
Creator: Ray, Manfred G.
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Morphological and Immunological Characterization of Earthworm Lumbricus terrestris Coelomocytes

Description: This research defines the morphological characteristics of the immune cells, coelomocytes, of the earthworm, Lumbricus terrestris. Such a definition of coelomocyte morphology can be correlated with immune function which will be of value in the development of a nonmammalian surrogate system to assess the immunotoxic potential of a terrestrial xenobiotics. Earthworms exposed to artificial soil dilutions of two complex xenobiotic mixtures, refuse derived fuel fly ash and a Superfund sire soil demo… more
Date: August 1992
Creator: Hariri, Maryam Feili
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Partner: UNT Libraries
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Colchicine Reversibly Inhibits Electrical Activity in Arthropod Mechanoreceptors

Description: Dendrites of cockroach tibial spine mechanoreceptors contain hundreds of free microtubules, which may have some relation to the generation of electrical activity. Deflection of a spine produces a train of action potentials. Continuous perfusion over a period of 4 hours results in no response decrement. Perfusion with 10mM colchicine reversibly inhibits the response within 5-7 minutes. Irreversible inhibition is produced by perfusion with 1mM vinblastine sulfate in perfusion solution containing … more
Date: August 1977
Creator: Reagan, Paul D.
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A Multiphasic Study of the Interaction Between the Branchiobdellid Cambarincola Vitrea and its Crayfish Host Procambarus Simulans

Description: 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.
Date: August 1973
Creator: Koepp, Stephen John
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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A Water Quality Study of Lake Texoma

Description: A series of four stations for sampling the waters of the Red Rivers and Lake Texoma was established. Water samples from top, middle, and bottom levels of these four stations were taken on monthly intervals during periods of homothermousity and on two-week intervals during periods of thermal stratification. These samples were analysed for the cations sodium, potassium, calcium, and magnesium, and for the anions normal carbonate, bicarbonate, sulfate, chloride, nitrate, water hardness (expressed … more
Date: June 1959
Creator: Goodman, John Willis
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Partner: UNT Libraries
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Identification of Glycine as the Factor in Peptone Which Induces Pleomorphism in Azotobacter Vinelandii

Description: The rigid peptidoglycan layer of the cell wall is responsible for maintaining the structural integrity of bacteria. Antibiotics such as penicillin exert their anti-bacterial effect by inhibiting synthesis of peptodoglycan, and enzymes such as lysozyme destroy cell integrity by hydrolyzing specific bonds in the interior of this macromolecule. Defective cells can no longer withstand the high turgor pressure within the cell because they are no longer protected by a rigid wall and tend to become fr… more
Date: December 1972
Creator: Rosenthal, Raoul Simon
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Partner: UNT Libraries
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The Physiology of Azotobacter Vinelandii Cysts

Description: The value of the adenylate energy charge [(ATP)+1/2(ADP)/(ATP)+(ADP)+(AMP)] in Azotobacter vinelandii cells was monitored during growth and germination in flask cultures. The miximal value of 0.88 was attained during mid-log phase; this declined gradually to 0.50 by late stationary phase. When these cultures were transferred to encystment media, the adenylate energy charge decreased to an average value of 0.40 as the vegetative cells encysted and remained unchanged during the next 20 days. Ency… more
Date: December 1980
Creator: Aladegbami, Solomon L.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Effects of Nutrient Media on Growth and Morphology of Azotobacter Vinelandii

Description: The work described in this thesis was undertaken to study the reasons why Azotobacter vinelandii ATCC 12837 after incubation in Burk's nitrogen-free liquid will not form as many colonies when plated on Difco Tryptic Soy Agar as when planted on Burk's nitrogen-free agar. The difference in growth of A. vinelandii on the two agars was established by performing viable cell-plate counts. The difference in growth was most apparent at 24-hours incubation of the Burk's liquid-media cultures. Phase cont… more
Date: August 1974
Creator: Butsch, Robert W.
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Peregrine Falcon (Falco peregrinus) Subspecies Phylogenomics Using Whole Genome Re-Sequencing

Description: Peregrine falcon subspecies taxonomy is widely debated due to uncertainty in their evolutionary history and unresolved phylogenetic reconstruction using both morphological and molecular data. Previous genetic work has shown limited support for subspecies taxonomy largely as a result of molecular markers used, potential contemporary gene flow, incomplete lineage sorting, and ancestral polymorphisms. With the advent of next-generation sequencing, the cost of generating large amounts of sequence d… more
Date: December 2020
Creator: Meeks, Garrett W.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Production, Location, and Binding of Violacein in Janthinobacterium

Description: Violacein is a purple pigment typically produced by species of Chromobacterium and Janthinobacterium. A soil isolate, identified as Janthinobacterium, was studied. Maximal pigmentation occurred at 250C under aerobic conditions in the Keeble and Cross medium. Intracellular pigment was shown to be located in the cell membrane. Comparision of pigment production and growth curves indicated that violacein is synthesized in the cell and released into the environment possibly as a result of cell lysis… more
Date: May 1988
Creator: Lin, Ying-Chuan
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Partner: UNT Libraries
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