UNT Theses and Dissertations - 418 Matching Results

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A Preliminary Report on the Effect of Roentgen Rays on the Formed Elements of Avian Blood

Description: This problem consists primarily in determining the numerical value of the leukocytes after different amounts of roentgen rays had been applied to the subjects. The Atomic Energy Commission set up a problem concerning the effects of roentgen rays on the fertility in chickens, and grants were given to two institutions to study this. The blood work in this paper was an off-shoot from one of these five fertility grants.
Date: August 1954
Creator: Berger, Gillett
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Pressure-Flow Relationships in the Isolated Cerebral Circulation of the Dog

Description: The purpose of this investigation is to determine the pressure-flow relationships in the isolated canine cerebral vascular bed. These relationships in vessels which supply an organ surrounded by bone are theoretically influenced by limiting factors which are not present in those vessels surrounded by soft tissue. An evaluation of the extent of these limitations is essential to thorough understanding of the dynamics of the cerebral vascular bed.
Date: June 1962
Creator: Alexander, William Carter
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Primary Productivity and Community Metabolism in a Small North Central Texas Pond Ecosystem

Description: Rates of primary production and community metabolism were monitored over a one year period using the diurnal oxygen method. Certain physico-chemical parameters were also measured, and autotrophic standing crops were estimated. An in-depth study was made of the phytoplankton community and various diversity indicies were calculated. Simple correlations were run between all parameters measured (biotic and abiotic), and their inter-relationships examined. Multiple linear regression analyses were us… more
Date: August 1975
Creator: Kelly, Martin H.
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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
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The Production of Fragile Cysts by an Aberrant Strain of Azotobacter Chroococcum Isolated from Soil

Description: The purpose of this study is to determine if a strain of Azotobacter chroococcum isolated from the soil in northern Louisiana produces cysts which are as resistant to deleterious agents as those produced by previously reported strains os Azotobacter.
Date: May 1969
Creator: Cagle, Gerald D.
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Properties of Normal Rat Kidney Cells Transformed by a Temperature-Sensitive Mutant (LA31) of Rous Sarcoma Virus

Description: The basis of this investigation is to characterize growth property differences in normal versus virally transformed cells. Using a temperature-sensitive mutant of Rous sarcoma virus, the cells' transformation state is regulated by the growth temperature; at 33°C the cells are transformed, while at 39°C the cells have normal characteristics. The morphology of NRK cells is elongated and fibroblastic; when transformed the cells are rounded. Normal cells grow to a monolayer and stop, while transfor… more
Date: August 1983
Creator: Connolly, John R. (John Robert)
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Qualitative and Quantitative Chromatographic Determination of Muscle Myosin Production in Control and Chronically Accelerated Chick Embryos

Description: The purpose of this investigation was to employ newly improved qualitative and quantitative chromatographic techniques to obtain purified myosin from 1 G and 3 G chick embryos and to determine if muscle myosin production either follows or precedes the unparallel bone growth during chronic acceleration as reported by several investigators.
Date: August 1968
Creator: Fletcher, C. T.
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A Qualitative Survey of the Airborne Algae, Protozoa, and Bacteria at the Denton Sewage Treatment Plant

Description: This study had a three-fold purpose. First, it was decided to determine if algae and protozoa were emitted to the air at the Denton sewage treatment plant. The information obtained could be of future importance in the fields of algal and protozoan ecology and public health. Second, it was decided to make a survey of the airborne bacteria at this plant. Some researchers have described bacterial air contamination at similar sewage treatment plants, but the one in Denton has not been studied. Thir… more
Date: May 1968
Creator: Mahoney, Joseph L.
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A Quantitative and Qualitative Bacterial Analysis of Pecan Creek

Description: Since Pecan Creek receives sewage wastes from an obviously inadequate disposal system, it seemed possible that it could receive pathogenic bacteria. The fact that these might be present in numbers sufficient to cause epidemics, provided the proper natural vectors were present, stimulated an interest in and the pursuance of this study.
Date: 1946
Creator: Cook, Vernice
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A Quantitative and Qualitative Bacterial Analysis of the Sewage Disposal System of Perryton, Texas

Description: This investigation had for its purpose the determination of first, the inefficiency of the Perryton, Texas, sewage disposal plant proper; and second the potential effectiveness of a lagoon now used to complete the sewage purification; and consequently, offset an apparent health hazard. The problem, as pursued, has consisted of first, the collection of sewage samples from the six stations listed in Table 1 over the period of time from September 23, 1949 to May 14, 1950; second, a quantitative an… more
Date: August 1950
Creator: Sullivan, Troy G.
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Quantitative Aspects of the Microflora of an Overland Flow Spray Irrigation Sewage Disposal System

Description: It was the purpose of this investigation to attempt to quantitate the microflora of the fields which receive the effluent from the Campbell Soup Plant, Paris, Texas, and to determine whether or not there is a correlation between the numbers and types of organisms present and the efficiency of purification of the system.
Date: May 1969
Creator: Jones, Rebecca
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A Rapid Modification of a Standard Disk-plate Antibiotic Susceptibility Test

Description: The objective of the work reported in this paper is one of a two-fold nature. The first objective is to develop a disk-plate sensitivity test that is more rapid than that of existing methods. The second requisite is that the materials, techniques, interpretation, and reporting of results be the sane as those required for the disk-plate method described in the Difco Manual.
Date: January 1955
Creator: Jackson, Leslie Warren
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Rectal Temperatures of the Cotton Rat, Sigmodon Hispidus (Rodentia : Cricetidae)

Description: This investigation has been concerned with determining the extent to which a small mammal, the cotton rat, may become acclimated to environmental temperatures, and the influence acclimation has upon a population. The study was also designed to determine if acclimation effects on a population can be seen in individual rats.
Date: August 1968
Creator: Cleveland, Arthur G.
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Relationship of Certain Fungi to Azotobacter in Nitrogen-Free Media

Description: Azotobacter and various fungi were grown together in nitrogen-free media. Maximal fungal growth in the medium used was possible only at the expense of Azotobacter cells and growth was always accompanied by acid production. When the medium reached a pH of 2, the bacterial cells were aggregated on fungal hyphae and the culture fluid appeared to be free of Azotobacter. Aspergillus niger grew well at the expense of viable bacteria and other fungi grew well on heat-killed cells of A. vinelandii. Mem… more
Date: August 1976
Creator: Ray, Manfred G.
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Remote Sensing of Landscape-Level Ecological Attributes at Ray Roberts Lake in North Texas

Description: Biological diversity is a key component in assessing ecosystem health. Alteration, degradation and loss of habitat due to human influence is currently the primary stressor resulting in decreases in diversity. Reliable assessment of large areas in terms of biological integrity are needed for conservation and preservation efforts. Remotely sensed data provide an integrated view of reflected electromagnetic energy over large areas of the earth. These energy patterns provide unique spectral signatu… more
Date: December 1997
Creator: Smith, David P. (David Paul), 1956-
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The Reproductive Consequences of Carriers of Methylenebisacrylamide-Induced Balanced Reciprocal Translocations in Mus Musculus

Description: N,N'-methylenebisacrylamide (MBA) was studied because of its effectiveness in inducing heritable translocations in germ cells of male mice. The health impact of translocations was studied through anatomical analysis of the progeny of semisterile translocation carriers. As expected, the semisterility of translocation carriers resulted primarily from embryonic death during periimplantation stages due to unbalanced chromosome sperm segregants. Among conceptuses that survived to mid- and late-gesta… more
Date: May 1989
Creator: Kile, Joanna L. (Joanna Le)
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The Reproductive Cycles of Five Species of Texas Centrarchids

Description: This thesis examines the reproductive cycles of five species of Texas centrarchids: the largemouthed black bass, the black crappie, the bluegill, the redear sunfish, and the striped bass. In this report attention is given to the reproductive cycles of the five species for a period of one year.
Date: 1948
Creator: Smith, Charles G.
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