UNT Theses and Dissertations - Browse

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A Bacteriological Survey of a Freshwater Reservoir

Description: In this study organisms that can be subcultured from lake water, using a prescribed procedure, limit, to an extent, the population, or portions of the population, that can be monitored. In essence, what is taking place is that a set of conditions is set forth and a study is made of the bacteria that will grow under these prescribed conditions.
Date: January 1968
Creator: Stiles, John Clayborn
Partner: UNT Libraries

The Effects of Hexadecanol on the Microbiota of Lake Hefner

Description: It seemed desirable to investigate more fully the effect of hexadecanol on the microbial population of a reservoir. It was the purpose of this investigation to determine the effect of hexadecanol on the micro-biota of Lake Hefner, to ascertain which organisms were stimulated by hexadecanol both in the laboratory and the reservoir, and to investigate the degradation of hexadecanol by microorganisms selected from Lake Hefner.
Date: May 1968
Creator: Dickson, Kenneth L.
Partner: UNT Libraries

Experimental Trichinosis in Birds

Description: This work concerns itself with essentially four experiments: (1) the cecum-injective-infection experiment; (2) the anus-injective-infection experiment; (3) the mouth ingestive-infection with larvae, and (4) the mouth ingestive-infection with the flesh of infected rats.
Date: December 1970
Creator: Poon, Yau-Lun
Partner: UNT Libraries

Comparative Ultrastructural Study between Young and Adult forms of Trypanosoma Lewisi

Description: 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.
Partner: UNT Libraries

Isolation and Partial Characterization of a Bacterium Which Gives Off Filtrable Cells

Description: The present study was on the isolation of a bacterium capable of producing filtrable forms which passed through the 0.45ยต filter membrane and regenerated the parental form; the testing of the true filtrability of the isolate; the relationship between growth of the isolate and appearance of filtrability; partial characterization of the isolate and visualization of the elements that passed through the membrane filter with electron microscopy and shadow casting technique.
Date: May 1973
Creator: Siu, Henry H. W.
Partner: UNT Libraries

Studies on the Morphology and Biology of Cotton Rats (Sigmodon hispidus) from Northern Mexico to Southern Nebraska

Description: This investigation was designed to evaluate the need for retaining both Sigmodon hispidus texianus and Sigmodon hispidus berlandieri as subspecific designations. An attempt was made to demonstrate bioclimatic variation and reproductive seasonality in cotton rats. The validity of applying the results of isolated studies of cotton rat populations to the species as a whole was examined.
Date: December 1971
Creator: Cleveland, Arthur Gordon
Partner: UNT Libraries

Heat Resistance in Vegetative Cells and Cysts of Azotobacter

Description: The purpose of the current study is to determine something of the nature of the heat resistance in Azotobacter, if in fact this is found to exist. An attempt is made to determine the specific physiological state associated with heat resistance as well as to resolve this resistance quantitatively.
Date: August 1969
Creator: Rosenthal, Raoul S.
Partner: UNT Libraries

Pleomorphism in Selected Genera of Algae

Description: It is the purpose of this study to ascertain what environmental factors might cause morphological changes exhibited by certain algae, also to determine if this variation in morphology is vegetative, reproductive, or artifactual in nature, and to show what effects these changes in morpohology might have on classification of the organisms in question.
Date: June 1967
Creator: Bruton, Barbara A.
Partner: UNT Libraries

Some Effects of X-Irradiaion on the Adrenal Response to Hypothalamic Stimulation in Rats

Description: Exactly where in the hypothalamus is the adrenal-pituitary response to X-irradiation "triggered" or initiated? Moreover, does ionizing radiation act directly on specific centers in the brain or does it act indirectly via the production of some humoral agents? Finally, what role does the hypothalamus play in the radiation-syndrome? The purpose of the present study was to attempt to answer these questions by determining the effects of two stressor agents, X-irradiation and electrical stimulation applied either singly or together, on the activity of the adrenal-pituitary axis. The parameters measured were changes in plasma corticosterone, in circulating eosinopihils, and in adrenal gland weight.
Date: January 1967
Creator: Agnew, Robert Laing
Partner: UNT Libraries

A Screening of Fungi for Metabolites Inhibitory to the Growth of Bloom-Forming Blue-Green Algae

Description: Since many approaches to dealing with algal blooms are inefficient, expensive, or harmful, it was concluded that a biologically-synthesized chemical agent, specifically inhibitory to pre-bloom algal cells, might prove helpful in controlling algal blooms. Fungi were chosen as the biological entities to investigate for such a chemical.
Date: December 1970
Creator: Hardcastle, Ronald V.
Partner: UNT Libraries

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

Description: 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.
Partner: UNT Libraries

A Study of Malate Dehydrogenase Isoenzymes in the Midge Larva Glyptotendipes barbipes

Description: Two isoenzymes of malate dehydrogenase were isolated and partially purified from the midge larva Glyptotendipes barbipes. Differential centrifugation followed by cellulose acetate and polyacrylamide gel electrophoresis revealed one isoenzyme associated with the mitochondrial fraction and another form found only in the cytoplasm.
Date: May 1972
Creator: Jones, Vicki E.
Partner: UNT Libraries

Some Acute Effects of X-Irradiation (LD100) on Plasma and Adrenal Tissue Histamine in Rats

Description: The effects of a lethal dose (1380 r) of X-irradiation on plasma and adrenal tissue histamine levels of rats were studied. The plasma histamine response was triphasic (increase at 1-3 hours, decrease at 5 and 9 hours and return to control at 24 hours post-irradiation). The adrenal tissue histamine response was found to be biphasic (decrease at 1 to 9 hours and a return to control level at 24 hours post-irradiation).
Date: May 1972
Creator: Ferguson, James L.
Partner: UNT Libraries