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The Influence of a Return of Native Grasslands upon the Ecology and Distribution of Small Rodents in Big Bend National Park

Description: In the southwestern United States there is a delicate balance between the existing grasslands and the rodent fauna. The purpose of this investigation was to determine the influence of secondary succession of native grasslands upon the ecology and distribution of small rodents. Two methods of determining the rodent species were plot quadrates and trap lines using Sherman live traps.
Date: August 1971
Creator: Baccus, John T.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Lipids and Phospholipase Activity of Vibrio Cholerae

Description: One purpose of this investigation is to determine the fatty acid and lipid content of typical Vibrio cholerae cells. The comparison of cholera lipid constituents with those of closely-related bacteria might be of taxonomic value. Furthermore, chemical characterization of the cholera vibrio could provide useful criteria for identification of these disease-producing microorganisms.
Date: August 1972
Creator: Brian, Buford Leo
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Nymphs of the Stonefly (Plecoptera) Genus Taeniopteryx of North America

Description: Nymphs of the 9 Nearctic Taeniopteryx species were reared and studied, 1976-78. Two morphologically allied groupings, the Taeniopteryx burksi-maura, and T. litalonicera- starki complexes corresponded with adult complexes. A key separating 7 species, based primarily upon pigment patterns and abdominal setal arrangements, was constructed. Taeniopteryx lita and T. starki were indistinguishable; T. burksi was separated from T. maurawhen no developing femoral spur was present. This study was based u… more
Date: May 1978
Creator: Fullington, Kate Matthews
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Drumming Behavior of Selected Nearctic Stoneflies (Plecoptera)

Description: Drumming was recorded for 11 of 13 Nearctic stonefly species, representing 4 families. Both male and female signals were obtained from 5 species, and were either 2-way or 3-way communications. Signals were species-specific; those of males and females varied from 3-39 and 1-14 beats/ signal, respectively. Duration of male signals varied from 105-8,016 ms; those of females, except Perlinella drymo (1 beat), varied from 402-1318 ms. Signals among related taxa showed greatest similarities. Duration… more
Date: August 1976
Creator: Zeigler, David D.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Effect of Operant Behavior on the Metabolism of 5-Hydroxytryptamine

Description: The role of operant behavior in the metabolism of brain 5-hydroxytryptamine (5-HT) turnover was investigated. Two and one-half hours following the administration of 150 mg/kg of para-chlorophenylalanine (PCPA), a specific inhibitor of tryptophan hydroxylase, levels of 5-HT were compared in sedentary and performing rats. Whole brain levels of serotonin were reduced in both responding and sedentary animals; however, differences between these groups were not statistically significant. The drug ind… more
Date: August 1979
Creator: Shepard, Paul
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Bioreactor Landfill Cell Feasibility Study ' Reference to City of Denton Subtitle-D Permit #1590A Landfill

Description: The City of Denton Landfill, Permit #1590A, utilizes “Dry-Tomb” techniques for disposal and promotion of municipal solid waste stabilization, as described by the Resource Conservation and Recovery Act (RCRA) prohibition in 40 CFR. Bioreactor research suggests re-circulating leachate increases biodegradation rates and reduces long-term monitoring from fifty years to less than ten years. Current procedures that are followed at Denton's landfill, literature review and the use of the Hydrologic Eva… more
Date: May 2002
Creator: Roberts, Elizabeth
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Structural Analysis of the Genes Encoding the Oxalocrotonate Branch of the Pseudomonas putida TOL Plasmid pDKI meta-cleavage Pathway and the Expression of the xy1G Gene Product in Escherichia coli

Description: Three overlapping DNA fragments from the lower operon of Pseudomonas putida TOL plasmid pDK1, covering the xy1IH genes and downstream flanking region, were cloned into pUC19. They include a 2.8 kbp XhoI fragment, a 2.7 kbp PstI fragment and a 2.0 kbp EcoRI-HindIII fragment. They were subjected to DNA sequence analysis. The xy1I (4-oxalocrotonate decarboxylase) and xy1H (4-oxalocrotonate tautomerase) genes were found to possess coding regions of 792 and 189 nucleotides, respectively. A possible … more
Date: December 1992
Creator: Luo, Xuebin
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Responses of Pristina leidyi Smith 1896 (Naididae: Oligochaeta) to Cadmium, Vanadium, and Some Environmental Factors

Description: Concern over sediment toxicity has increased the need for toxicity test information with organisms that inhabit sediments. Oligochaetes are exposed to toxicants through feeding and direct body contact with aquatic sediments. Chronic testing with oligochaetes has historically focused on tubificids with test lengths of one year or more to encompass several generations. Most naidid oligochaetes have generation times of three to seven days and could provide chronic information in a matter of weeks.… more
Date: May 1990
Creator: Smith, David P. (David Paul), 1956-
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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The Stress Protein Response of Pimephales promelas to Copper

Description: Organisms synthesize stress proteins in response to a variety of stressors. The 68/70-kDa proteins (synonymous to the 72/73-kDa proteins) have shown to be the most promising stress proteins, and have been proposed as a biomarker of general organismal stress. The 68/70-kDa proteins were used in an antigen/antibody based approach to determine the duration of the stress protein response of Pimephales promelas following an acute exposure to copper sulphate.
Date: May 1992
Creator: Covington, Sean M.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Interactions among Temperature, pH, and Cyfluthrin on Survival of the Fathead Minnow Pimephales promelas

Description: The 96-hr LC50 of cyfluthrin in Pimephales promelas ata temperature of 23*C and a pH of 8 was 1.08 g/L. The toxicity of cyfluthrin was inversely related to temperature and pH. A temperature of 10*C and a pH of 6 significantly decreased the 96-hr LC50 to 0.009 gg/L. Likewise, sublethal exposures to cyfluthrin significantly affected the fathead minnow's ability to tolerate high and low temperatures. Cyfluthrin compromised the fathead minnow's lower temperature tolerance (CTMin) by 60C and the upp… more
Date: December 1991
Creator: Heath, Susan M.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Sediment Characteristics and Bioavailability of Sorbed Neutral Organic Compounds

Description: Several sediment characteristics were analyzed to determine their suitability for use as potential normalization factors for the bioavailability of neutral organic compounds sorbed to sediments. Percent organic carbon, cation exchange capacity and particle surface area were measured sediment characteristics that varied sufficiently to encompass the range in observed sediment toxicity. Laboratory sediment toxicity test data using fluoranthene suggest that there is no biologically significant cor… more
Date: December 1989
Creator: Suedel, Burton C. (Burton Craig)
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Thermal Selection at an Enzyme Locus in Populations of the Red Shiner, Notropis lutrensis, Receiving Hypolimnion Effluents from a Reservoir

Description: Genetic variation was examined at 19 loci encoding enzymatic and general proteins Notropis lutrensis from the Brazos River in Texas. The thermal regime of the Brazos River below Possum Kingdom Reservoir is altered due to the release of water from the hypolimnion. Summer water temperatures fluctuate as much as 7^oC. Levels of heterozygosity at the malate dehydrogenase-2 locus were correlated with the degree of water temperature fluctuation at each locality. The isozymes from three homozygous pat… more
Date: May 1978
Creator: Richmond, M. Carol
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Effects of Exogenous Steroids on the Adrenal Plasma Membrane Alteration of Steroidogenesis and Cell Morphology

Description: Using cultured Y-1 mouse adrenal tumor cells which produce the steroid 20(-hydroxypregn-4-en-3-one (20-DHP), it was found that 10-5 M corticosterone and deoxycorticosterone increased basal and inhibited ACTH-induced 20-DHP production. The steroid effects were concentration-dependent, reversible, and specific since six other steroids did not stimulate steroidogenesis and varied in their ability to inhibit ACTH-induced steroidogenesis. Cytochalasin D inhibited steroid-stimulated 20-DHP production… more
Date: August 1982
Creator: Mattson, Mark Paul
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Drumming Behavior of Selected North American Stoneflies (Plecoptera)

Description: Drumming is first described for five North American stonefly species, Acroneuria evoluta, Doroneuria baumanni, Isoperla namata, Chernokrilus misnomus, and Pictetiella expansa. Signals of Acroneuria lycorias, Phasganophora capitata and Isoperla signata are further described. Drumming was not recorded from Amhinemura delosa. Signals of A. evoluta are the most complex yet recorded in Plecoptera. Doroneuria baumanni, P. expanse, C. misnomus and P. capitata have 2-way exchanges. Male D. baumanni pro… more
Date: December 1983
Creator: Maketon, Monchan
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Serological Relationships of Azotobacter Species

Description: In order to clarify the taxonomic problems which exist among the group azotobacter by serological method, 24 cultures of Azotobacter including 9 species were tested as antigens in Ouchterlony plates against 3 different antisera obtained from rabbits immunized with A. chroococcum ACl6, A. macrocytogenes St.M. and A. vinelandii 12837, respectively. The results showed more cross reactivity in intraspecies reactions than in interspecies ones and indicated the presence of a common immunogenic determ… more
Date: December 1976
Creator: Chang, Chyan-chuu
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Comparative Toxicity of Refuse-Derived Fuel Fly Ash on Two Species of Earthworms, Lumbricus terrestris and E. foetida, Using an Artificial Soil Exposure Protocol

Description: Research estimated toxicity of refuse-derived fuel fly ash (RDF-FA) on two earthworms species, Lumbricus terrestris and Eisenia foetida. Specific objectives were to: (1) Compare their 14-day LC50s under light and dark conditions; (2) separate toxicity due to osmotic, pH and physical factors from that of heavy metal contaminants; (3) compare relative differences of artificial soil and commercial soil as exposure media for evaluating toxicity to earthworms. The 14-d LC50s for L. terrestris in dar… more
Date: May 1991
Creator: Jahani, Aghamolla
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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The Effect of Human Alpha Interferon on Rat Kidney Cell Infected with Temperature-Sensitive Mutant of Rous Sarcoma Virus

Description: LA31-NRK and B77-NRK are established cell lines that were normal rat kidney cells transformed with temperature-sensitive mutant (LA31) and wild-type Bratislava 77 (B77) of Rous sarcoma virus. It is recognized that many transformation-induced changes differentiate between normal and transformed cells. Morphology and four parameters of transformed cells such as saturation density, anchorage independence, plasminogen activator, and colony stimulating factor were used as indicators to observe the e… more
Date: May 1983
Creator: Chang, Shiuan
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Distribution, Abundance, and Food Habits of Larval Fish in a Cooling Reservoir

Description: Analysis of larval fish collected at four stations in a 330-ha cooling reservoir indicated Dorosoma spp. were most numerous at all stations, followed by Lepomis spp. and Percina Macrolepida. Largest numbers and greatest diversity of larval fish were found at the station least affected by thermal effluent; the mid-lake station provided the smallest numbers and least diversity. The two warmwater stations were intermediate, with similar numbers and diversity. Diversity and abundance of zooplankton… more
Date: December 1978
Creator: Mitterer, Lana Gayle
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Isolation and Characterization of Malic Enzyme from Ascaris suum

Description: A procedure for the isolation of malic enzyme from muscle tissue of the roundworm Ascaris suum is described. The fractionation method yields relatively large quantities of the enzyme,with a specific activity of fifteen moles of malate converted to pyruvate and carbon dioxide per min per mg at 25º. Homogeneity was established with analytical ultracentrifugation, zone electrophoresis, isoelectric focusing, and rechromatography. The molecular weight of the enzyme was 250,000, and it is dissociated… more
Date: December 1972
Creator: Fodge, Douglas W.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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An Assay Method for Determining Extra-Cellular Lipases from Pseudomonas aeruginosa

Description: 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 iso… more
Date: May 1978
Creator: Christensen, John N.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Seasonal and Spatial Variability of the Microcrustacean Community in Lake Texoma, Texas and Oklahoma

Description: Twenty-eight species of zooplankton were identified from Lake Texoma. Seasonal density of the overall microcrustacean community and seasonal cycles of individual species were compared with northern populations and any available literature from the Southwest. Cycles of occurrence and abundance were similar to those observed in northern populations but tended to occur earlier in the year due to higher temperatures. Spatial distributions within the reservoir were heavily influenced by nutrient and… more
Date: August 1980
Creator: Crist, Lawrence W.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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The Effect of Nine Diet and Water Combinations on the Culture Health of Ceriodaphnia Dubia

Description: Culture health of Ceriodaphnia dubia was evaluated for organisms cultured using all combinations of three foods and three waters. Criteria used to assess health of cultures included adult and neonate weights, time required to produce first broods, neonate production, adult survival, and resistance to hexavalent chromium. Diet/water combinations which produced the most neonates were not found to produce adults which were more resistant to chromium than those which produced fewer neonates. Of tho… more
Date: May 1990
Creator: Patterson, Paul W. (Paul William)
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Temperature Tolerance of Freshwater Fish Exposed to Water-Borne Cadmium

Description: Lethal toxicity values (96 h LC50; mg Cd/L) for the test species were similar: Lepomis cyanellus, 11.52; Notropis lutrensis, 6.62; Pimephales promelus, 3.58. However the effects of cadmium concentration and exposure time on temperature tolerance varied between species. Neither cadmium concentration nor exposure time had a significant effect on the CTM of green sunfish. Both cadmium concentration and exposure time had a significant effect on the CTMs of red shiners and fathead minnows. By day 10… more
Date: May 1987
Creator: Carrier, Roxie
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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