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Serological Characterization of Members of the Genus Streptomyces

Description: This investigation involved isolation and characterization of specific antigenic materials from known species of Streptomyces. The resulting antigens were then used to establish serological relationships between a number of different species. These groupings were, in turn, compared with similar studies recently established by the ISP, in which other taxonomic criteria were used. By these means, the serological characteristics of the Streptomyces were evaluated for their potential utility as added taxonomic tools in the establishment of species designations within this group.
Date: August 1968
Creator: Taylor, Gerald Roger
Partner: UNT Libraries

The Immune Response of Guinea Pigs as Influenced by Hypobaric Pressure and Normoxic Environment (Part I); Membrane Filter-Fluorescent-Antibody Method for Detection and Enumeration of Bacteria in Water (Part II)

Description: In this work experimental design and tests were established to determine whether antibody production in guinea pigs injected with a bacterial antigen is Influenced by the environment of simulated high altitude with normoxic conditions. Hematological and electrophoretic studies were simultaneously run with the antibody determinations as a check on related responses of the animals.
Date: August 1969
Creator: Reeder, Dennis James
Partner: UNT Libraries

Polycyclic-Aromatic-Hydrocarbon-Induced Alterations in the Physio-Chemical Characteristics of Escherechia Coli Dexyribonucleic Acid

Description: Prior to 1965 the interactions of polycyclic aromatic hydrocarbons with DNA (Deoxyribonucleic acid) had been but moderately studied. It was concluded that, although a controversy existed, an apparent interaction occurred between DNA and certain aromatic hydrocarbon molecules and that the interaction was not an artifact of the reaction system.
Date: August 1969
Creator: Chapel, J. Frederick (James Frederick)
Partner: UNT Libraries

Selected Physiological and Biochemical Studies on Blue-Green Algae

Description: Twenty-two different unialgal clonal isolates have been obtained at random for experimental purposes over a period of about one year. Also, during this period, at least 12 other species or strains have been isolated into unialgal cultures which had not yet been identified and/or significantly cleared of heterotrophic contaminants.
Date: August 1969
Creator: Wyatt, Jimmy T. (Jimmy Trueman), 1922-
Partner: UNT Libraries

Light and Electron Microscope Studies on the Chemotherapeutic Effect of a Combination of Dimethyl Sulfoxide and Hematoxylin on a Transplantable Lymphosarcoma

Description: Investigations concerning the cellular response of tumor tissue to treatment with dimethyl sulfoxide and hematoxylin have not been reported. To establish the response of neoplastic tissue and cells to this combination of agents, this study was undertaken to determine the effects of dimethyl sulfoxide and hematoxylin on a transplantable lymphosarcoma in mice.
Date: January 1970
Creator: Rogers, Thomas D., 1939-
Partner: UNT Libraries

Food, Feeding Selectivity, and Ecological Efficiencies of Fundulus notatus (Rafinesque) (Osteichthyes; Cyprinodontidae)

Description: This study was made to further define the trophic dynamics of Fundulus notatus by determining its ration composition under natural conditions, measuring feeding selectivity under various laboratory conditions of prey-species composition and availability, and determining the efficiencies with which F. notatus utilizes ingested chironomid larvae.
Date: August 1970
Creator: Atmar, Gerald Legare
Partner: UNT Libraries

Odorous Metabolite and Other Selected Studies of Cyanophyta

Description: The purpose of this study was as follows: 1. Elucidate the laboratory conditions under which Anabaena circinalis produces the noxious odor component or components in maximum concentration, 2. Isolate the major noxious odorous metabolite(s), 3. Structurally define the odorous metabolite(s), 4. Quantitate the amount of metabolite(s) that a given amount of the organism produced.
Date: August 1970
Creator: Henley, Don E.
Partner: UNT Libraries

Passive Dispersal of Algae and Protozoa Internally and Externally by Selected Aquatic Insects

Description: This investigation was concerned with three aspects of the problem of passive dispersal of algae and protozoa by aquatic insects: the role of odonates in passive dispersal of viable small aquatic organisms, the passage of viable algae and protozoa through digestive tracts of field-collected herbivorous and carnivorous aquatic insects, and the viability duration of selected algae, during insect transport under monitored conditions.
Date: December 1970
Creator: Solon, Bernard M. (Bernard Michael), 1932-
Partner: UNT Libraries

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.
Partner: UNT Libraries

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

Description: 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.
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

Carbon Flux in Reservoir Sediments

Description: The central objective of the study was to fractionate sedimenting organic materials according to their source (allochthonous or autochthonous) and ultimately to determine the degree of biodegradability of contributions from either source with particular reference to activities at the mud-water interface.
Date: May 1973
Creator: Newton, Charles Eugene
Partner: UNT Libraries

Primary Productivity and Nutrient Relationships in Garza-Little Elm Reservoir

Description: A large, multi-basin, reservoir (Garza-Little Elm Reservoir) in north central Texas was studied to determine the relative effects of various parameters on primary productivity. The basins were impounded several years apart,thus allowing the influence of age on water chemistry and biota to be considered. Another principal influence on water quality was secondary sewage effluent that entered one basin from a nearby source.
Date: May 1973
Creator: Smith, Jerry Allen
Partner: UNT Libraries

Biological Nitrogen Fixation in Two Southwestern Reservoirs

Description: This investigation has determined the presence of biological nitrogen fixation in two reservoirs in the southwestern United States: Lake Arlington and Lake Ray Hubbard. Subsequent tests have gathered baseline data on the effects of various biological, chemical, and physical parameters on in situ nitrogen fixation in these reservoirs. Of specific importance is the relationship between nitrogen fixation arid occasional blooms of blue-green algae which produce such problems as testes and odors in these water-supply impoundments.
Date: August 1973
Creator: Lawley, Gary G.
Partner: UNT Libraries

Fitness-Related Alterations in Blood Pressure Control: The Role of the Autonomic Nervous System

Description: Baroreflex function and cardiovascular responses to lower body negative pressure during selective autonomic blockade were evaluated in endurance exercise trained (ET) and untrained (UT) men. Baroreflex function was evaluated using a progressive intravenous infusion of phenylephrine HCL (PE) to a maximum of 0.12 mg/min. Heart rate, arterial blood pressure, cardiac output and forearm blood flow were measured at each infusion rate of PE. The reduction in forearm blood flow and concomitant rise in forearm vascular resistance was the same for each subject group. However, the heart rate decreases per unit increase of systolic or mean blood pressure were significantly (P<.05) less in the ET subjects (0.91 ± 0.30 versus 1.62 ± 0.28 for UT). During progressive lower body negative pressure with no drug intervention, the ET subjects had a significantly (P<.05) greater fall in systolic blood pressure (33.8 ± 4.8 torr versus 16.7 ± 3.9 torr). However, the change in forearm blood flow or resistance was not significantly different between groups. Blockade of parasympathetic receptors with atropine (0.04 mg/kg) eliminated the differences in response to lower body negative pressure. Blockade of cardiac sympathetic receptors with metoprolol (0.02 mg/kg) did not affect the differences observed during the control test. It was concluded that the ET subjects were less effective in regulating blood pressure than the UT subjects, because of 1) an attenuated baroreflex sensitivity, and 2) parasympathetic-mediated depression of cardiac and vasoconstrictive responses to the hypotensive stress.
Date: December 1986
Creator: Smith, Michael Lamar, 1957-
Partner: UNT Libraries

New Descriptions, Intraspecific Variation and Systematic Importance of Drumming Behavior in Selected North American Plecoptera

Description: Drumming behavior is described for the first time in 33 North American Plecoptera species, and signals of an additional five species, Pteronarcys pictetii, Acroneuria abnormis, Paragnetina media, Clioperla clio and Isogenoides zionensis, are further detailed. An out-group comparison of behavioral characters in all 104 world species whose drumming is known showed that the behavior is more advanced in the Arctoperlaria Group Systellognatha than in the Group Euholognatha. In general, tapping, monophasy, touching, sequenced exchange and less than 50 taps/answer are ancestral states, and rubbing, grouping, phasing, tremulation, interspersed exchange and equal or more than 50 taps/answer are derived states. There has been some co-evolution between abdominal structure and drumming behavior. Scanning Electron Micrographs of 30 species showed that the primitive state of tapping is ascociated with three classes of abdominal structure: (1) absence of derived structures, (2) lobes or vesicles, and (3) hammers. The derived behavior of rubbing, however, occurs only in species with derived structures, and is predominant in species having vesicles and hammers. Drumming can be used as a line of evidence to aid in defining genera and species, since the behavior has a variable degree of specificity or exclusiveness in all species, particularly in groups of species I have studied in the genera Isoperla, Pteronarcys and Taeniopteryx. Typical and variant computer-synthesized male calls of three stonefly species were tested with live females. They responded at high levels in such a way that the important informational content conveyed was identified as: (1) a minimal threshold of beat numbers, and (2) a discriminant window of beat intervals. Rub frequency and bibeat calling were critical informational parameters in two species.
Date: December 1986
Creator: Maketon, Monchan
Partner: UNT Libraries

Neuropharmacological Characteristics of Tolerance for Cocaine Used as a Discriminative Stimulus

Description: The main purpose of this research was to investigate the phenomenon of tolerance to cocaine. Tolerance is operationally defined as a decreased drug effect due to prior history of drug administration. The animal model that was chosen to investigate tolerance to cocaine was the drug discrimination model, which is an animal analogue of human subjective drug effects. In the drug discrimination procedure, animals are trained to emit one behavior when injected with saline. In the present experiments, rats were trained to press one lever when injected with cocaine, 10 mg/kg, and a different lever when injected with saline for food reinforcement. Once rats are trained, they can accurately detect the cocaine stimulus greater than 95% of the time.
Date: August 1987
Creator: Wood, Douglas M. (Douglas Michael)
Partner: UNT Libraries

Life History Biology of the Desert Nesting Seagull Larus modestus

Description: Gray gulls Larus modestus are unique among birds of northern Chile as the only species nesting in the interior Atacama Desert, and the only seagull nesting far (30 - 100 km) from surface water. During breeding-nesting (August - February) gray gulls congregate on the coast of northern Chile where they feed and initiate courtship. As early as August, breeding pairs commute daily to the inner desert to establish nesting territories, round-trip distances of 60-200 Km. During incubation (30 days) and brooding (7 days) adults alternate daily foraging flights to the coast. Afterwards, both adults forage daily for their chick(s) until fledging (ca. 60 days). Foraging flights and thermoregulatory costs during the period of maximal solar radiation, when ground temperatures may reach 61 C in the day and drop to 2 C at night, have selected for adaptations which minimize those costs: tolerance of hypothermia and hyperthermia; dark plumage; low egg-shell water vapor conductance; low standard metabolic rate; elaborate repertory of thermoregulatory behavior which allow adults to take advantage of microclimatic variations in the desert and minimize costs relative to a sympatric congenor, Larus belcheri scheduling foraging flights to take advantage of optimal atmospheric conditions and presence of forage fish (anchovies) close to the surface; scheduling migration to coincide with anchovy production and levels of interspecific competition; and reduced clutch size ( ≤ 2) relative to most seagulls. Periodic El Nino-Southern Oscillations (ENSO), which reduce principal food items of gray gulls, have selected for 'bet hedging" tactic by which L. modestus either ceases reproduction or varies clutch size between one and two, as observed during and after the 1982-83 ENSO. During a typical reproductive season, breeding pairs allocate a minimum of 39 percent of their net metabolized energy (NME) to foraging flights. Including energy content of eggs, females have an overall ...
Date: December 1987
Creator: Guerra Correa, Carlos Guillermo
Partner: UNT Libraries

Physiological Responses of Myriophyllum spicatum to Time Varying Exposures of Diquat, 2,4-D and Copper

Description: The physiological responses of Myriophyllum spicatum to 2,4-D, diquat and copper were quantified using a plant tissue viability assay, and daily measures of dissolved oxygen and pH. Correlations of herbicide tissue residues to physiological response measures were determined and the relationship was used to develop exposure-response models. Diquat and copper had a greater effect on plant tissue viability than was observed for 2,4-D. Diquat produced greater reductions in dissolved oxygen concentrations and pH values than 2,4-D or copper. Copper exposure had the least effect on these parameters. Exposure-response models developed for 2,4-D predicted effective control at plant tissue residues ranging from 4000 to 4700 mg/kg. Aqueous exposure concentrations necessary to produce effective control plant tissue residues ranged from 0.20 to 0.40 mg/L. Exposure-response models developed for diquat predicted effective control at plant tissue residues ranging from 225 to 280 mg/kg. Aqueous exposure concentrations necessary to produce effective control plant tissue residues ranged from 0.113 to 0.169 mg/L. Exposure-response models developed for copper predicted effective control at plant tissue residues ranging from 680 to 790 mg/kg. Aqueous exposure concentrations necessary to produce effective control plant tissue residues ranged from 0.32 to 0.64 mg/L. Model predictions for 2,4-D, diquat and copper were within 0.5 mg/L of the manufacturers' label recommendations for these herbicides. The use of laboratory microcosms in development of exposure-response models for diquat and copper produced results comparable to those using the larger-scale greenhouse systems. Diquat effectively controlled M. spicatum at lower tissue residues than 2,4-D or copper. In addition, initial aqueous exposure concentrations were also lower for diquat. Use of these models in field situations should be coupled with considerations of quantity of biomass present and environmental conditions, such as turbidity, in order to accurately calculate exposure concentrations necessary for effective tissue residues. Thus, the use of these models ...
Date: May 1988
Creator: Rocchio, Patricia Mary
Partner: UNT Libraries