Annual Lipid Cycles in the Lizard Cnemidophorus Tigris (open access)

Annual Lipid Cycles in the Lizard Cnemidophorus Tigris

Annual lipid cycles were determined for adult male and female Cnemidophorus tigris collected near El Paso, Texas during 1970-1971.
Date: August 1972
Creator: Gaffney, Fred G.
System: The UNT Digital Library
Antibody Adsorption Used in Identification of Similar Streptomyces Species (open access)

Antibody Adsorption Used in Identification of Similar Streptomyces Species

This investigation involved the production of specific antisera against known International Streptomyces project strains of Streptomyces.
Date: January 1970
Creator: Lassiter, Carroll B.
System: The UNT Digital Library
Aryl Hydrocarbon Hydroxylase and Sixteen Alpha Hydroxylase in Cultured Human Lymphocytes (open access)

Aryl Hydrocarbon Hydroxylase and Sixteen Alpha Hydroxylase in Cultured Human Lymphocytes

Cultured human lymphocytes may be assayed for aryl hydrocarbon hydroxylase (AHH) in whole cell preparations. The optimum assay conditions are pH 8.5, and 1.5 mM Mg++. The reaction is linear with time and cell number, and is inhibited by CO. Estradiol may inhibit induction of AHH by 3-methylcholanthrene, but is a poor competitor for the enzyme. A Caucasian population was assayed for AHH activity. The distribution was lognormal; no difference was found in cultured cells from males and females or smokers and nonsmokers. Cells from relatives of lung cancer patients showed higher activity. An American Indian population showed no difference from the Caucasian population in enzyme level. No linkage was found between AHH and 16a-hydroxylase.
Date: December 1975
Creator: Coomes, Marguerite L.
System: The UNT Digital Library
An Assay Method for Determining Extra-Cellular Lipases from Pseudomonas aeruginosa (open access)

An Assay Method for Determining Extra-Cellular Lipases from Pseudomonas aeruginosa

The applicability of an isotopically labelled assay system to determine the lipase production in Pseudomonas aeruginosa was evaluated. Supernatant from cultures of Pseudomonas aeruginosa grown in a medium containing olive oil was incubated with a substrate containing labelled trioleate. Fatty acids were isolated by means of a liquid-liquid partition system. Enzyme activity was determined by measuring the amounts of free fatty acid by liquid scintillation counting. Findings indicate that the isotopicallylabelled, liquid-liquid partitioning assay is reliable, sensitive and adaptable to rapid assay conditions. It was also determined that different strains of Pseudomonas aeruginosa produce varying amounts of lipase. Partial purification of supernatant by gel filtration produced two protein peaks showing enzymatic activity.
Date: May 1978
Creator: Christensen, John N.
System: The UNT Digital Library
The Autecology of Celtis Laevigata in Flood Plain Forests of Denton County, Texas (open access)

The Autecology of Celtis Laevigata in Flood Plain Forests of Denton County, Texas

This thesis describes the present nature of one facet of some of the flood plain forest stands in Denton County, Texas. The specific purpose was to demonstrate the presence or absence of difference between the Celtis laevigata (commonly known as the hackberry, southern hackberry or sugarberry) populations in stands on Denton Creek and Elm Fork of the Trinity River.
Date: January 1970
Creator: Hander, Lecil B.
System: The UNT Digital Library
Biochemical Genetics of Certain Species of the Blackbird Family Icteridae (open access)

Biochemical Genetics of Certain Species of the Blackbird Family Icteridae

Starch gel electrophoresis was used to compare 14 proteins encoded by 15 loci for seven species of the family Icteridae. A close genetic relationship among these species was classified into three groups. The Agelaiine group contained Agelaius phoeniceus, Sturnella magna, and S. neglecta. The Quiscaline group contained Euphagus cyanocephalus, Cassidix mexicanus, and Quiscalus quiscula. Molothrus ater, the most divergent, was placed in a separate group. Divergence times for the seven species were compared to the literature. Heterozygosity of the seven populations of the two species of Sturnella were compared to determine factors influencing their divergence. Two factors proposed were heterosis in S. neglecta and possible hybridization between S. neglect and S. magna.
Date: December 1974
Creator: Smith, Jackson Kelly
System: The UNT Digital Library
Biochemical Genetics of the Pocket Gopher Genus Geomys, and its Phylogenetic Implications (open access)

Biochemical Genetics of the Pocket Gopher Genus Geomys, and its Phylogenetic Implications

Electrophoretic techniques were utilized for the demonstration of variation in 22 proteins from 24 natural populations of four species ( G. bursarius, G. pinetis, G. arenarius and G. personatus ) of the Geomys complex of pocket gophers. Of the 24 structural loci , 19 were considered to be polymorphic. Five of the six esterases contributed greatested to the polymorphism while non-esterase proteins generally showed low values. In the GeoMys complex of pocket gophers in this study,selection appeared to be the most important influence on genetic structure with some evidence of random drift in two of the four species. Populations of G. arenarius and G. personatus had the highest average interspecific genetic similarities to G. bursarius and . pinetis was the most divergent. Biochemical evidence supports the phylogeny of Geomys based on morphological and fossil data.
Date: December 1974
Creator: Penney, Dan F.
System: The UNT Digital Library
The Biological Elimination of Phenols in the Effluent of a Wood Preserving Plant (open access)

The Biological Elimination of Phenols in the Effluent of a Wood Preserving Plant

The removal of phenols from the waste waters of wood preserving plants has always presented problems. The purpose of this paper is to investigate the possibility of employing a biological system to reduce the phenol content of effluent from these plants.
Date: August 1971
Creator: Rainey, John G.
System: The UNT Digital Library
Biological Nitrogen Fixation in Two Southwestern Reservoirs (open access)

Biological Nitrogen Fixation in Two Southwestern Reservoirs

This investigation has determined the presence of biological nitrogen fixation in two reservoirs in the southwestern United States: Lake Arlington and Lake Ray Hubbard. Subsequent tests have gathered baseline data on the effects of various biological, chemical, and physical parameters on in situ nitrogen fixation in these reservoirs. Of specific importance is the relationship between nitrogen fixation arid occasional blooms of blue-green algae which produce such problems as testes and odors in these water-supply impoundments.
Date: August 1973
Creator: Lawley, Gary G.
System: The UNT Digital Library
Biosystematic Study of a Desmodium Complex (open access)

Biosystematic Study of a Desmodium Complex

An examination of the Desmodium canescens complex (D. canescens; D. tweedyi; D. illinoense) has resulted in the delimitation of a previously unreported alliance between D. canescens and D. tweedyi. The following points support this view: (a) morphological data taken from herbarium and garden specimens indicate that for many characters, the mean values of D. canescens and D. tweedy are not significantly different (b) breeding experiments have shown that artificial interspecific hybridization is possible between D. canescens and D. tweedyi (c) cytological studies have shown that D. canescens and D. tweedyi have a base number of x = 11, while D. illinoense has a base number of x = 10. A new combination is suggested: Desmodium canescens var. tweedyi (Britt.) Williams.
Date: December 1977
Creator: Williams, John G., 1949-
System: The UNT Digital Library
Capillary Permeability to Narrow-Range Macromolecular Dextrans at Normal and Hypobaric Pressures (open access)

Capillary Permeability to Narrow-Range Macromolecular Dextrans at Normal and Hypobaric Pressures

In view of its varied concepts and interpretations, and because of the discrepancies produced by the previous utilization of polydispersed dextrans, a study using extremely narrow-range molecular weight dextran fractions was initiated to reevaluate and consolidate some of the aspects of capillary permeability. A portion of the study was performed under decreased barometric pressure in order to clarify further some of the mechanisms involved in particulate transfer across the capillary endothelial membranes. Gel filtration procedures augmented the study as an assessment of the polydispersity effects of the dextrans employed.
Date: December 1972
Creator: Norris, John Anthony
System: The UNT Digital Library
Carbon Flux in Reservoir Sediments (open access)

Carbon Flux in Reservoir Sediments

The central objective of the study was to fractionate sedimenting organic materials according to their source (allochthonous or autochthonous) and ultimately to determine the degree of biodegradability of contributions from either source with particular reference to activities at the mud-water interface.
Date: May 1973
Creator: Newton, Charles Eugene
System: The UNT Digital Library
A Carcinogenic Agent Elaborated by Liver Cells from Lymphosarcoma-Bearing Mice (open access)

A Carcinogenic Agent Elaborated by Liver Cells from Lymphosarcoma-Bearing Mice

Liver cells from lymphosarcoma-bearing DBA/1J mice were shown, by parabiotic culture with normal liver cells from isologous mice, to elaborate an agent which could pass a 25 mu filter and transform the normal cells to a malignant state.
Date: August 1972
Creator: Blachley, Jon David
System: The UNT Digital Library
Chemical Composition of the Peptidoglycan of Vitreoscilla Stercoraria (open access)

Chemical Composition of the Peptidoglycan of Vitreoscilla Stercoraria

The peptidoglycan layer of Vitreoscilla stercoraria, ATCC 15218, was isolated from intact cells after treatment with sodium lauryl sulfate (SLS) and digestion with Pronase. Amino acid and amino sugar content was analyzed and 67% of the total present was made up of glutamic acid, alanine, diaminopimelic acid (DAP), and glucosamine in a molar ratio of 1:1.7:1:0.7. Electron microscopy of the final peptidoglycan product showed a thin, delicately folded sacculus which exhibited a morphology different from that of the intact vegetative cells. Within these sacculi occurred electron-dense structures which were assayed and found to be poly- 3-hydroxybutyrate (PHB) granules. The final yield of peptidoglycan was 2.9% of the dry weight of the intact vegetative cell.
Date: August 1976
Creator: Levit, Gary
System: The UNT Digital Library
Chronic Acceleration and Osteogenesis (open access)

Chronic Acceleration and Osteogenesis

The effect of excess gravity on bone-forming elements of the growing perichondrial shaft of embryonic chicks was investigated through the use of the transmission electron microscope and various cytochemical techniques.
Date: August 1973
Creator: Borgens, Richard Ben
System: The UNT Digital Library
Cigarette Residues Affect Steroidogenesis in Cultured Y-1 Mouse Adrenal Tumor Cells (open access)

Cigarette Residues Affect Steroidogenesis in Cultured Y-1 Mouse Adrenal Tumor Cells

This study (1) quantitatively compared steroid production in cultured Y-l mouse adrenal tumor cells exposed to Camel and Carlton-smoke derived residues, and (2) localized the effects in the cell. Basal steroid production was increased by Camel residues but not by Carlton, while ACTH stimulation was interfered with by both residues. Camel basal stimulation was comparable to that of cAMP, and was abolished by Cytochalasin D. The stimulation was also comparable to that of cholera toxin, which activates adenyl cyclase. Results indicate that residue components dissolve in the membrane stimulating adenyl cyclase at a point similar to or before that utilized by cholera toxin for its stimulating effect.
Date: December 1979
Creator: Morris, Paula D.
System: The UNT Digital Library
Colchicine Reversibly Inhibits Electrical Activity in Arthropod Mechanoreceptors (open access)

Colchicine Reversibly Inhibits Electrical Activity in Arthropod Mechanoreceptors

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 1% dimethyl sulfoxide. Deuterium oxide does not inhibit at concentrations less than 50%, nor does it counteract inhibition by 10mM colchicine. Colchicine may be affecting (1) intracellular microtubules, (2) membraneous tubulin, (3) other membrane components, or (4) axoplasmic transport of essential materials to the sensory dendrites.
Date: August 1977
Creator: Reagan, Paul D.
System: The UNT Digital Library
Comparative Chemistry of Thermally Stressed North Lake and Its Water Source, Elm Fork Trinity River (open access)

Comparative Chemistry of Thermally Stressed North Lake and Its Water Source, Elm Fork Trinity River

To better understand abiotic dynamics in Southern reservoirs receiving heated effluents, water was analyzed before and after impoundment in 330 ha North Lake. Macronutrients, metals, and chlorinated hydrocarbons were measured. Concentrations of nutrients and metals in sediments were quantified in this 2 yr study. River water prior to impoundment contained 16 times more total phosphorus, and supported 23 times more Selenastrum capricornutum cells in an algal assay than reservoir water. The reservoir has essentially no drainage and since evaporation is high, the concentrations of many dissolved solids have increased since the reservoir was filled in 1958. North Lake is now phosphorus limited. Apparently altered chemical equilibria have caused precipitation or adsorption of phosphorus with calcium and iron.
Date: December 1976
Creator: Sams, Barry L.
System: The UNT Digital Library
A Comparative Study of Passive Transfer Mechanisms of Tuberculin and Chemical Contact Delayed Hypersensitivities in the Guiea Pig (open access)

A Comparative Study of Passive Transfer Mechanisms of Tuberculin and Chemical Contact Delayed Hypersensitivities in the Guiea Pig

This study is concerned with a critical comparison of the passive transfer mechanisms of tuberculin and chemical contact hypersensitivities in the guinea pig by use of a four phase experimental approach.
Date: June 1970
Creator: Nunez, William Joseph
System: The UNT Digital Library
Comparative Ultrastructural Study between Young and Adult forms of Trypanosoma Lewisi (open access)

Comparative Ultrastructural Study between Young and Adult forms of Trypanosoma Lewisi

The purpose of this study was to examine the ultrastructure of both young (dividing form) and adult (stationary form) of Trypanosoma lewisi. Changes observed between the two forms of the organism were related directly to data obtained from previous comparative biochemical studies conducted on these forms of Trypanosoma lewisi.
Date: August 1973
Creator: Abdul-Salam, Jasem M.
System: The UNT Digital Library
A Comparison of Thermogenesis by Selected Substrates on Hypothermic Rat Liver (open access)

A Comparison of Thermogenesis by Selected Substrates on Hypothermic Rat Liver

The thermogenic effects in hypothermia of four substrates--alanine, glycine, ethano, and pyruvate - were studied in seventeen experiments. Albino rats were decapitated, and their livers were removed. The livers were homogenized with phosphate buffer at -5° C. After equilibration in a refrigerated Warburg apparatus at 20° C, the substrates were added and tissue respiration was recorded over three hours. Heat production was calculated from O2 uptake and CO2 production. Results showed that alanine, glycine, and pyrvate yielded 93.19, 89.86, and 89.89 x 10^6 kg-cal compared to a control value of 86.11 x 10^-6 kg-cal. Ethanol provided 110.31 x 10^-6 kg-cal, a value significantly greater than for the other substrates. The substrates studied, especially ethanol, did, therefore increase heat production in an artificially hypothermic environment in homogenized rat livers.
Date: August 1979
Creator: Long, James T.
System: The UNT Digital Library
Degradation of Homologous Polymerized Deoxyribonucleic Acid by Azotobacter Vinelandii ATCC 12837 (open access)

Degradation of Homologous Polymerized Deoxyribonucleic Acid by Azotobacter Vinelandii ATCC 12837

The purpose of this study was twofold. The first was to isolate, purify, and characterize the deoxyribonucleic acid (DNA) of Azotobacter vinelandii ATCO 12837. The second was to determine if there was irreversible binding of homologous 32P labeled DNA to recipient A. vinelandii cells.
Date: August 1972
Creator: Barnes, Wayne Riley
System: The UNT Digital Library
Density, Distribution, Production and Drift of Benthic Fauna in a Reservoir Receiving Thermal Discharges from a Steam Electric Generating Plant (open access)

Density, Distribution, Production and Drift of Benthic Fauna in a Reservoir Receiving Thermal Discharges from a Steam Electric Generating Plant

The effects of thermal discharges on the density, distribution, production, and drift of benthic organisms were studied at North Lake reservoir.
Date: December 1972
Creator: Durrett, Charles W.
System: The UNT Digital Library
Differences in Protein Constituents of Some Azotobacter Species (open access)

Differences in Protein Constituents of Some Azotobacter Species

This study used polyacrylamide gel electrophoresis to study the acid-phenol soluble proteins of five strains (A. vinelandii 12837, A. vinelandii 0, A. chroococcum 8004, A. macrocytogenes 8702, A. tumefaciens) of bacteria grown on Burk's nitrogen-free media, Trypticase Soy Broth, and 0.3% butanol medium. The results showed that the protein patterns can be used for the identification and possibly the taxonomic classification of the Azotobacter. The change of phenotype of the bacteria in different media followed the change of protein quantity and quality. There was no absolute similarity between any two of the species studied and this suggests a genetically heterogenous group of organisms while the amount of common proteins suggests close genetic relationships. Further studies are necessary to confirm the status of A. tumefaciens.
Date: August 1975
Creator: Hsu, Li-Chu Yao
System: The UNT Digital Library