UNT Libraries - 48 Matching Results

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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
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Biochemical Genetics of Certain Species of the Blackbird Family Icteridae

Description: 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… more
Date: December 1974
Creator: Smith, Jackson Kelly
Item Type: Refine your search to only Thesis or Dissertation
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Cigarette Residues Affect Steroidogenesis in Cultured Y-1 Mouse Adrenal Tumor Cells

Description: 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 acti… more
Date: December 1979
Creator: Morris, Paula D.
Item Type: Refine your search to only Thesis or Dissertation
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Comparative Chemistry of Thermally Stressed North Lake and Its Water Source, Elm Fork Trinity River

Description: 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 reser… more
Date: December 1976
Creator: Sams, Barry L.
Item Type: Refine your search to only Thesis or Dissertation
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The Detection of Poliovirus in Denton Sewage by Immunofluorescence and Immunodiffusion Techniques

Description: Several final sewage effluents from the Denton Disposal Plant were demonstrated to contain Poliovirus types II and III. Pleated encapsulated filters at pH3.5 enhanced the recovery of the Poliovirus at a higher tier in comparison with nitrocellulose filter (Millipore) and glass fiber filter of pore size 0.45u. This thesis explores problems that face us today in our quest to eliminate viral pathogens from the natural and waste water needed for human, domestic, and industrial consumption. Prelimin… more
Date: August 1975
Creator: Olaiya, Felix Ayodele
Item Type: Refine your search to only Thesis or Dissertation
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Dielectric Properties of Azotobacter vinelandii in a Microwave Field

Description: A resonant frequency cavity was used to determine the dielectric properties of various preparations of Azotobacter vinelandii ATTC 12837. It was found that the bacteria investigated did interact with microwave radiation in the absence of free water. The data presented here indicate that bacteria demonstrate frequency specific dielectric properties. The techniques employed in these experiments may also be used to determine microwave spectra of other species of bacteria in different physiological… more
Date: December 1978
Creator: Hargett, John M.
Item Type: Refine your search to only Thesis or Dissertation
open access

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
open access

The Distribution of Pathogenic Pseudomonas aeruginosa in Sewage

Description: The purpose of this study was to extend our understanding of the ecological relationships of P. aeruginosa by investigating the differences or similarities between the strains of this organism found in sewage and those found as pathogens in human infections. This research was approached by comparing the serological types of P. aeruginosa isolated from sewage contaminated waters in Argentina (South America) to those isolated from sewage contaminated waters in Texas. They were typed with sera obt… more
Date: May 1974
Creator: Labay, Joseph Edward
Item Type: Refine your search to only Thesis or Dissertation
open access

DNA-DNA Hybridization of Methane Oxidizing Bacteria

Description: Bacteria classified in the family Methylomonadaceae must derive their carbon from one-carbon compounds. They are characterized by the possession of internal membranes of two types. Type I membranes are layered and fill the middle of the cells while type II membranes form concentric layers around the periphery of the cells. Also, there are two metabolic pathways by which the methylobacteria assimilate one-carbon compounds. Further evidence of this dichotomy was sought by DNA-DNA saturation hybri… more
Date: December 1976
Creator: Ackerson, Jill W.
Item Type: Refine your search to only Thesis or Dissertation
open access

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
open access

Effect of Amino Acids on Growth and Cartenogenesis in Corynebacterium Species Strain 7E1C

Description: Studies were evaluated on the effects of known growth factors on the growth and carotenogenesis of Corynebacterium species strain 7ElC. The complex medium, Tryptic Soy Broth,was found to stimulate growth and production of more pigment in the light and in the dark than did a mineral salts-glucose medium. A complete amino acid mixture added to LSG enhanced carotenogenesis in the dark in Corynebacterium 7ElC, while B-vitamins retarded carotenogenesis. No absolute requirement for one or more amino … more
Date: May 1977
Creator: Coughran, Carolyn S.
Item Type: Refine your search to only Thesis or Dissertation
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The Effect of Ethanol on Cardiac Activity and Brain Respiration in Chick Embryos

Description: This study concerned the effect of ethanol on cardiac activity and brain respiration in chick embryos. Ethanol dosages tested ranged from 1.0 mg to 4.0 mg/g weight. Each experiment lasted at least 150 minutes. Cardiac activity in terms of total waveform energies was integrated and printed out for plotting and analysis. The embryonic heart rates were simultaneously determined from physical graph tracings. The embryonic brain respiration was measured using a differential microrespirometer. The ef… more
Date: August 1976
Creator: Newman, James J.
Item Type: Refine your search to only Thesis or Dissertation
open access

Effect of Indole-3-Acetic Acid on the Nucleic Acids of Synchronous Cultures of Chlorella Pyrenoidosa

Description: It was the purpose of this study to investigate the effect of various concentrations of IAA on the nucleic acids of Chlorella pyrenoidosa TX 7-11-05. The time during the life cycle when the greatest effect occurred was investigated by the use of synchronous cultures.
Date: May 1972
Creator: Peterson, James Arthur
Item Type: Refine your search to only Thesis or Dissertation
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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
open access

Effects of an Acute Bout of Near-Maximal Intensity Exercise on the Cardiac Enzymes in Human Sera

Description: The Cardiac Profile, a pattern of serum enzyme changes seen within seventy-two hours after an AMI, is diagnostic aid for detecting occurrence of infarcts. The effects of exercise stress on the Cardiac Profile aid clinicians in avoiding diagnostic errors in patients immediately after exercise. Five male volunteers ran from six to ten miles. Serum enzyme levels were monitored serially three days before and five days after stress. Enzyme activity was determined spectrophotometrically and electroph… more
Date: May 1979
Creator: Goheen, Bernadette A.
Item Type: Refine your search to only Thesis or Dissertation
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Effects of Ribavirin on Normal Rat Kidney Cells and Chicken Embryo Fibroblasts Infected with Rous Sarcoma Virus

Description: Ribavirin, a synthetic nucleoside, was found to inhibit the replication of Rous sarcoma viruses (RSV) and subsequent cell transformation in chick embryo fibroblasts (CEF). It also blocked the transformation of normal rat kidney (NRK) cells infected with temperature-sensitive mutants of RSV. The action of Ribavirin was found to be reversible as removal of the drug from the NRK cells reversed the effects on cell transformation. Ribavirin appears to have a static effect on cell growth of both NRK … more
Date: April 1979
Creator: Jenkins, Frank J.
Item Type: Refine your search to only Thesis or Dissertation
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Effects of Turbidity on Gilling Rates and Oxygen Consumption on Green Sunfish, Lepomis cyanellus

Description: Laboratory studies conducted at 5, 15, 25, and 35 C measured changes in gilling rates and oxygen consumption of green sunfish in response to exposure to bentonite clay suspensions. The tests indicate that gilling rates are not affected by bentonite clay suspensions below 2125 FTU at 5 C, 1012 FTU at 15 C, and 898 FTU at 25 C. At turbidity levels exceeding 1012 FTU at 15 C and 898 at 25 C, gilling rates increased 50-70%. Tests were inconclusive at 35 C. Oxygen consumption rates were found to be … more
Date: May 1974
Creator: Horkel, John Duane
Item Type: Refine your search to only Thesis or Dissertation
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The Evolutionary Genetics of Campostoma anomalum and Campostoma oligolepis

Description: Electrophoretic variation in 12 proteins encoded by 16 loci was analyzed to compare the genetic relationships of 18 natural populations representing two species of stoneroller minnows, Campostoma anomalum and C. oligolepis. Ten of the loci were monomorphic and fixed for the same allele in all populations of both species. One locus, Mdh-2, was found to separate both species. Mean heterozygosity for both species was 0.072. Estimates of levels of inbreeding indicated this phenomenon is operating i… more
Date: December 1978
Creator: Merritt, Ronald L.
Item Type: Refine your search to only Thesis or Dissertation
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Evolutionary Genetics of Three Semispecies of Wood Rats--Neotoma Albigula, Neotoma Micropus, and Neotoma Floridana

Description: Electrophoretic variation in 18 proteins encoded by 20 autosomal loci was used to compare the genetic relationships of 19 natural populations representing three species of the subgenus Neotoma. Of the 20 loci examined nine were monomorphic and fixed for the same allele in all populations. No more than seven loci were polymorphic within a single population. Genetic variability was expressed as the proportion of loci heterozygous in the average individual of a population. Heterozygosity in the th… more
Date: December 1975
Creator: Nejtek, Michael E.
Item Type: Refine your search to only Thesis or Dissertation
open access

Food Habits of Stoneflies (Plecoptera) in the Gunnison and Dolores Rivers, Colorado

Description: Gut contents of 2,500 stonefly nymphs, comprising 10 species, from the Gunnison and Dolores Rivers, Colorado were examined from Dec., 1974-Oct., 1975. Perlidae species were carnivorous feeding primarily on chironomids, mayflies and caddisflies. Seasonal patterns of ingestion and preference varied among species and predator sizes and between rivers. Early instar polyphagous species utilized detritus in the fall, eventually shifting to carnivorous habits as they grew through winter-spring. Pteron… more
Date: August 1976
Creator: Fuller, Randall L.
Item Type: Refine your search to only Thesis or Dissertation
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Genic Differentiation and Evolution in the Ground Squirrel Subgenus Ictidomys (Spermophilus)

Description: The genetic structure of 26 natural populations of three species (S. tridecemlineatus, S. mexicanus, and S. spilosoma) of the Ictidomys subgenus of ground squirrels was analyzed using chromosomal and electrophoretic techniques. Chromosomal variation was not observed in S. mexicanus, and only slight karyotypic variation was found in the other two species. Chromosomal evidence indicated hybridization between S. tridecemlineatus and S. mexicanus, placing these species within the classical definiti… more
Date: December 1975
Creator: Cothran, E. Gus, 1951-
Item Type: Refine your search to only Thesis or Dissertation
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