UNT Theses and Dissertations - 379 Matching Results

Search Results

prev Results: 97 - 120 next
open access

The Dynamics of a Planktonic Microcrustacean Community in a Small North Central Texas Pond Ecosystem

Description: Seven species of planktonic microcrustacea were identified from the North Texas State University Golf Course Pond. Total adult microcrustacean community density, biomass and biocontent, and seasonal cycles of each species were compared with northern populations. Species diversity and evenness indices were highest in summer and lowest in spring. Variations in microcrustacean density showed a positive correlation with density of phytoplankton. Temperature had a direct effect on metabolic rates of… more
Date: December 1976
Creator: Smith, George Arthur
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

An Ecological Study of the Pine Vole, Microtus Pinetorum, in Northeast Texas

Description: This study dealt with the life history and population dynamics of the pine vole, Microtus pinetorum. In the past there has been a void of ecological material concerning this small mammal in the southwestern region of its range. From November, 1969, through February, 1970, a survey was conducted in Marion County and Harrison County, Texas, to determine the most suitable habitat for an ecological study of Microtus pinetorum. A study was then initiated in March, 1970, and continued through March, … more
Date: August 1971
Creator: Greer, Roy E.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

An Ecological Survey of the Herpetofauna of Palo Pinto County, Texas

Description: The purpose of this research was to compile a presence list of reptiles and amphibians that occur in Palo Pinto County, Texas, and to investigate the ecological distributions and zoogeographic affinities of these herpetiles. The study area was chosen primarily because of its location in North Central Texas and its rugged topography, which sets it apart from the surrounding area.
Date: August 1969
Creator: Porter, Stuart T.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

An Ecological Survey of the Reptiles and Amphibians of Wise county, Texas

Description: The purpose of this study was to record the relationships between the reptiles and amphibians of Wise County and the ecological subdivisions of the area. Wise County was chosen because of the heterogenity of the area and because of its proximity to other counties which have been previously and similarly studied.
Date: January 1970
Creator: Welch, Donald A.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

The Effect of Carbon Monoxide on the Growth of an Aquatic Streptomycete

Description: The major purpose of this investigation was to determine the effect of carbon monoxide on the development of various morphological phases of a single isolate of the aquatic streptomycetes and to elucidate the physiological differences between terminal respiration in the primary and secondary stages. A secondary purpose was to repeat the work of Michael Lee Higgins involving the effect of anaerobiosis on the growth of the organism.
Date: August 1966
Creator: Francisco, Donald Edward
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Effect of Colchicine on Neuronal Excitabilty

Description: The abundance of microtubules in receptive dendrites suggests they may function in sensory transduction. Responses of frog muscle spindle receptors and joint receptors is inhibited within 25 minutes by 50 mM colchicine, a microtubuledisrupting agent. The inhibition is reversible upon removal of colchicine, and the time course of recovery is comparable to that of inhibition. Frog olfactory responses are briefly inhibited by washing the olfactory mucosa with perfusion fluid. Colchicine accentuate… more
Date: August 1978
Creator: Okafo, Ngozi
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Effect of Light and Other Environmental Factors on Growth and Carotenogenesis of Corynebacterium Species Strain 7E1C

Description: This investigation studies effects of environmental factors on growth and carotenogenesis in Corynebacterium strain 7ElC. Changes in pH were found to effect growth more than carotenogenesis. However, certain nutrients or long incubation periods stimulated carotenoid formation more than growth. Dark conditions in a mineral salts-glucose medium stimulated growth, but minimized carotenogenesis. Tryptic soy broth or yeast extract elicited carotenogenesis in darkness. Although brief light exposure d… more
Date: August 1974
Creator: Howard, Marta E.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

The Effect of Light on Carotenoid Synthesis in Corynebacterium 7E1C

Description: The effects of light, light "mimicking" chemicals, and protein synthesis inhibitors on the photo-induced carotenogenesis of Corynebacterium 7EIC were studied. Changes in the dosage of fluorescent light applied to dark grown cells showed a dose related carotenogenic response. Maintaining the same dosage but varying the wavelength of monochromatic light revealed that light with a wavelength of 280 to 450nm was responsible for photo-induction. It further showed a peak of photo-induction between th… more
Date: May 1977
Creator: Endicott, George R.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

The Effect of Long-Term Moderate Amounts of Ethanol on Paraventricular Nuclei Activity on Cold Stressed Adult Rats

Description: The effects of moderate, long-term intake of ethanol on the hypothalamic response to cold stress were examined. The long-term experimental animals were given .25 ml of 28% ethanol or .25 ml of water orally once a day, five days a week for fourteen months. A stainless steel electrode was then surgically implanted into the paraventricular nucleus, after which the animal was subjected to cold stress (-150 C, 10 min.). Recordings were taken in the forms of frequency and activity. The data clearly i… more
Date: December 1990
Creator: McKinnon, Mark S. (Mark Steven)
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

The Effect of Media Constituents on Growth and Pigment Production of Mycobacterium Phlei, Pseudomonas Fluorescens, Pseudomonas Aeruginosa, and Staphylococcus Citreus

Description: Little is known concerning the production and significance of bacterial pigments. There is seemingly an open field for studying the effects produced by varying the nutritive content of culture media upon which organisms are grown. This has led to an especial interest in, and the purpose of this investigation.
Date: 1947
Creator: Robbins, Finis E.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Effect of pH on the Persistence and Toxicity of Cyfluthrin to Chironomus Tentans

Description: The effect of pH upon the aquatic toxicity of cyfluthrin was determined in 48 h static acute toxicity tests using 2nd instar Chironomus tentans larvae. Tests were conducted in both dechlorinated tap water and lake water of pH 8.0, 7.2, and 6.6. After 48 h, immobilized and dead larvae were removed and replaced with 2nd instar larvae to assess the persistence of toxicity. Midges were cultured in water adjusted to the pH values used in testing. Toxicity if cyfluthrin varied inversely with pH. An i… more
Date: May 1992
Creator: Hambleton, Faith Ann (Faith Ann Elizabeth)
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

The Effect of Repeated Antigen Injections on the C' and C'4 Titers in Guinea Pig Serum

Description: In this study the effects of repeated antigen injections on total complement (C') and C'4 of guinea pig serum were investigated to determine if constant antigenic stimulation would show changes in the C' and C'4 titers. Attempts were also made to correlate any changes with variations in antibody titers during the repeated antigen injections.
Date: June 1961
Creator: Teague, Perry Owen
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
Back to Top of Screen