States

The Larval Lipids of the Chironomid Midge Glyptotendipes Barbipes (Staeger) (open access)

The Larval Lipids of the Chironomid Midge Glyptotendipes Barbipes (Staeger)

This problem was concerned with determining the total lipid content and individual lipid composition of the larvae of a local chironomid, Glyptotendipes barbipes (Staeger).
Date: December 1971
Creator: Talent, John M.
System: The UNT Digital Library
Some Effects of Electrostatic Fields on Brain Activity in Rats (open access)

Some Effects of Electrostatic Fields on Brain Activity in Rats

This study concerned the effects of short-term exposures to continuous (10 kv/meter) and pulsed 20 volts at 640 cps/100 msecs) electrostatic fields on the EEG recorded from external electrodes and hypothalamic activity recorded from implanted electrodes in rats. Each experiment lasted at least 90 minutes. The total energies of the waveforms recorded were integrated and printed out for plotting and analysis. Besides the brain activity, the ECG, respiration, and temperature of the animals were also monitored before, during,and after exposure to the electrostatic fields.
Date: December 1971
Creator: McCain, Harry B.
System: The UNT Digital Library
Obligately Thermophilic Nitrogen-Fixation in Some Soil Bacteria (open access)

Obligately Thermophilic Nitrogen-Fixation in Some Soil Bacteria

In the work presented here, it is claimed that bacteria have been isolated which are capable of growth at high temperatures utilizing molecular nitrogen as their sole nitrogen source. Soil bacteria were isolated which grew at 55 C in nitrogen-free media. They were found to be obligatory thermophiles in nitrogen-free media and facultative thermophiles in media containing organically bound nitrogen.
Date: August 1971
Creator: Milam, Mary
System: The UNT Digital Library
Studies on the Morphology and Biology of Cotton Rats (Sigmodon hispidus) from Northern Mexico to Southern Nebraska (open access)

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

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
System: The UNT Digital Library
A Taxonomic Study of the Family Bacteroidaceae (open access)

A Taxonomic Study of the Family Bacteroidaceae

This study was performed to clarify the taxonomy of the bacteria in the family Bacteroidaceae.
Date: August 1971
Creator: Funderburk, Noel Roger
System: The UNT Digital Library
Effects of Carbaryl (1-Naphthyl-n-methylcarbamate) on Trichocorixa Reticulata (Hemiptera: Corixidae) and Glyptotendipes Barbipes (Diptera: Chironomidae) (open access)

Effects of Carbaryl (1-Naphthyl-n-methylcarbamate) on Trichocorixa Reticulata (Hemiptera: Corixidae) and Glyptotendipes Barbipes (Diptera: Chironomidae)

My study of the effects of carbaryl in aquatic systems under controlled laboratory conditions emphasized four major objectives: (1) to determine the acute toxicity of carbaryl to the herbivorous adult and immature Trichocorixa reticulata (Guerin)(Hemiptera: Corixidae), and to the omnivorous larvae of Glyptotendipes barbipes (Staeger) (Diptera: Chironomidae) under static bioassay; (2) to adapt a quantitative method of analysis for carbaryl in water and whole insect tissue extract; (3) to measure the accumulation of the insecticide by G. barbipes under static exposure; and (4) to quantify the uptake and loss of carbaryl by G. barbipes under daily-renewed sublethal dosages.
Date: December 1971
Creator: Gash, Stephen L.
System: The UNT Digital Library
The Influence of a Return of Native Grasslands upon the Ecology and Distribution of Small Rodents in Big Bend National Park (open access)

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

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.
System: The UNT Digital Library
X-irradiation Effects on the Action Potentials of Frog Sciatic Nerves Inhibited by Carbon Monoxide and Ouabain (open access)

X-irradiation Effects on the Action Potentials of Frog Sciatic Nerves Inhibited by Carbon Monoxide and Ouabain

The response of frog sciatic nerve action potentials to x-irradiation and metabolic (carbon monoxide) or transport (ouabain) inhibition was determined in an attempt to further identify the nature of radiation insult to nervous tissue. Carbon monoxide, ouabain (2 X 10-5 M), and nitrogen anoxia were shown to produce a near linear decline in action potential amplitude. The carbon monoxide and nitrogen inhibitions of activity were reversible in air; the carbon monoxide inhibition was light reversible. Ouabain inhibition was partially reversible by soaking the nerve in aerated Ringer's. Application of 120 kv x-rays (75 Kr at 4.9 Kr/min) to nerves during the linear decline in spike amplitude brought about a marked enhancement (146%) of inhibition by 99% CO/l% 02, nitrogen (136%), and ouabain (265%). All bhanges were shown to be statistically significant by a regression analysis. However, x-irradiation did not appear to alter the air reversibility of carbon monoxide and nitrogen inhibitions nor the reversibility in Ringerts of the ouabain inhibition. Additionally x-irradiation completely blocked light reversal of 98% CO/2% 02 inhibition and produced a decline in activity. A possible interpretation of these results is a compensation for radiation action at this dosage requiring metabolism and ion pump activity.
Date: December 1971
Creator: Thompson, Wesley J.
System: The UNT Digital Library