UNT Theses and Dissertations - 58 Matching Results

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Actinoplanes Philippinensis: Effect of Carbon Sources on Zoospore Production
Actinomycetes are able to utilize a great variety of carbohydrates, like sugar. The particular kind of sugar and its concentration has decisive effect on the growth of microorganisms. The proper nutritional media aids also in the production of spores. Based on this generalization, that the growth and sporulation of microorganisms are greatly influenced by the nature and the concentration of carbohydrates, an attempt has been made to study Actinoplanes philippinensis with respect to this influence.
The Adaptability and Present Status of Andropogon Ischaemum L. in Denton County, Texas
This investigation has been made with reference to the adaptability of Andropogon ischaemum, King Ranch bluestem, to various soils, various slopes, and various erosion conditions in Denton County.
Analysis of Phytoplankton Responses to Water Chemistry Dynamics in a Moderately Eutrophic North Texas Reservoir
Canonical correspondence analysis (CCA) was used to explore relationships between measured environmental variables and in situ phytoplankton communities in a moderately eutrophic North Texas Reservoir.
Assimilation of Inorganic Nitrogen by Aquatic Actinomycetes
It was the purpose of this investigation to present laboratory data concerning the assimilation of inorganic nitrogen by the aquatic actinomycetes. The strains of aquatic actinomycetes under consideration represented a cross section of those currently under culture at North Texas State University.
The Autecology of Celtis Laevigata in Flood Plain Forests of Denton County, Texas
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.
Bacterial Survey of Representative Denton County Wells with Special Reference to Sanitation
This thesis aimed to study the seventy-two representative wells of Denton County and to determine the possibilities of infection with typhoid organism. The sanitary survey and the test for Colon-Aerogenes bacteria show that 55% of the 72 wells studied are unsanitary, 27% are sanitary, and 18% are doubtful.
Bacteriological Studies of the Campus Drinking Fountains of North Texas State Teachers College Denton, Texas
"In order to gain an adequate idea of the sanitary condition of the drinking fountains on the North Texas State Teachers College campus, it was found necessary to approach these bacteriological studies from a seasonal point of view."--1.
A Bio-Chemical Comparative Study of the Plankton in Lake Dallas and Pecan Creek
The purpose of this investigation is to compare the dissolved and suspended organic material in Lake Dallas to that coming into the lake through Pecan Creek.
The Biological Elimination of Phenols in the Effluent of a Wood Preserving Plant
The removal of phenols from the waste waters of wood preserving plants has always presented problems. The purpose of this paper is to investigate the possibility of employing a biological system to reduce the phenol content of effluent from these plants.
Carbon Flux in Reservoir Sediments
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.
Comparative Chemistry of Thermally Stressed North Lake and Its Water Source, Elm Fork Trinity River
To better understand abiotic dynamics in Southern reservoirs receiving heated effluents, water was analyzed before and after impoundment in 330 ha North Lake. Macronutrients, metals, and chlorinated hydrocarbons were measured. Concentrations of nutrients and metals in sediments were quantified in this 2 yr study. River water prior to impoundment contained 16 times more total phosphorus, and supported 23 times more Selenastrum capricornutum cells in an algal assay than reservoir water. The reservoir has essentially no drainage and since evaporation is high, the concentrations of many dissolved solids have increased since the reservoir was filled in 1958. North Lake is now phosphorus limited. Apparently altered chemical equilibria have caused precipitation or adsorption of phosphorus with calcium and iron.
A Comparison of Predicted and Actual Trophic Status of Lake Ray Roberts, Texas Based on Chlorophyll A
Two years before impoundment, the trophic status of Lake Ray Roberts was predicted by applying the total phosphorus input into the Organization for Economic Cooperation and Development (OECD) eutrophication model. Predicted mean summer epilimnetic (MSE) chlorophyll a of Elm Fork arm, Isle duBois arm and Main Body were in the eutrophic category of the OECD model. Observed MSE chlorophyll a two years after impoundment of Elm Fork arm, Isle duBois and Main Body had not reached their predicted means and were at the mesotrophic-eutrophic boundary of the OECD model. Six years after impoundment, observed MSE chlorophyll a for Main Body, was closer to its predicted mean and in the eutrophic category of the OECD model. Six years after impoundment, Elm Fork arm was the most productive area of Lake Ray Roberts. Observed means of chlorophyll a, total phosphates, suspended solids and turbidity were often highest in the Elm Fork arm. Wastewater effluent from Gainesville and Valley View, TX, had an impact on productivity in Elm Fork arm.
A Comparison of the Carbon Dioxide and Oxygen Rate of Change Methods for Measuring Primary Productivity
The purpose of this study was to demonstrate the variability of oxygen and carbon dioxide rate of change methods for measuring primary productivity and respiration in an aquatic environment.
Composition and Distribution of the Vegetation in Farm Pastures in Denton County, Texas
This investigation has for its aim the determination and the evaluation of the vegetational composition in certain farm pastures in Denton County, Texas.
Correlation of Humus and Water Content on Saba Clay, Denton, Texas
This study is an attempt to determine the relationship between humus and the water found in it and how both effect soil in Denton county, Texas.
A Correlation of Humus with Water Content and Crop Rotation in San Saba and Denton Clays, Denton County, Texas
A study of the humus content and the water content of San Saba clay and Denton clay. Studies show that the physical properties of soil are conducive to moisture retention and the availability of moisture to plants.
Degradation of Phenolic Acids by Azotobacter Species Isolated from Sorghum Fields
Sorghum plants excrete phenolic acids which reduce subsequent crop yields. These acids accumulate in field soil by combining with soil and clay particles to form stable complexes which remain until degraded by bacterial metabolism. The amount of phenolic acids in soil samples were obtained by gas chromatography measurements, while Azotobacter populations were obtained by plate counts in 40 sorghum field samples from Denton County, Texas. One can conclude that increasing the Azotobacter population in the soil increased the degradation rate of phenolic acids proportionally. It is proposed that seed inoculation will introduce selected strains of Azotobacter into the soil. The presence of Azotobacter should increase crop size in subsequent plantings.
Distribution of Phosphates in a Sewage Plant and its Receiving Waters
The purpose of this paper is to detail the distribution and quantity of soluble phosphates in an activated sludge plant, its discharge creek, and receiving reservoir. The resultant analyses and comparison of data should provide some better understanding of the fate of phosphorus in a Southwestern waterway system.
The Dynamics of a Planktonic Microcrustacean Community in a Small North Central Texas Pond Ecosystem
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 two species of copepods. Metabolic rates of pond species were lower at common temperatures than those of northern populations. An estimate of annual energy flow through the pond ecosystem showed cladocerans contributed the greater percentage of total energy to the next trophic level.
Edaphic Factors Which Control the Distribution of the Common Mesquite, Prosopis Chilensis (Molina) Stuntz in Denton County, Texas
This paper deals with the distributional outgrowths of Prosopis chilensis (Molina) Stuntz, the common mesquite, in Denton County, Texas.
The Effects of Organic Surface Amendments on Soil Nutrients and Initial Tree Establishment
This study examined the effects of replicating woodland soil surface horizonation on the nutrient status of underlying soils and the initial establishment and growth of trees. A total of 283 container grown trees were planted in a bufferzone around a future landfill site. Control amendments consisted of an 8 cm layer (0.5 m3) of wood chips applied in a circular area of 4.6 m2 around the trees' planting pit. For the treatment, a 2.5 cm layer of composted biosolids (0.15 m3 or 80 Mg/ha) was applied in a circular area of 4.6 m2 around the trees' planting pit followed by an 8 cm layer (0.5 m3) of wood chips. The results indicate that the replication of woodland soil surface attributes using composted biosolids can significantly improve the nutrient status of underlying soil. Some significant effects were seen under control conditions, too. However, the effects on tree establishment and growth parameters were, for the most part, not statistically significant.
Eutrophic Levels of Different Areas of a Reservoir: A Comparative Study
It was the purpose of this investigation to attempt to demonstrate if differences in eutrophic levels existed among selected areas of Garza-Little Elm, and to demonstrate the role that sediments play in affecting eutrophication.
Evaluation in Soil Moisture in Soil and Water Conservation Practices in Denton, Texas
This investigation has attempted to show that soil and water conservation practices do increase the amount of soil moisture in five of Denton County, Texas soils: Denton clay, Durant clay, San Saba clay, Kirvin fine sandy loam, and Tabor fine sandy loam.
Evaluation of a Constructed Wetland to Reduce Toxicity from Diazinon at the Pecan Creek Wastewater Treatment Plant, Denton, TX
The City of Denton Pecan Creek Wastewater Treatment Facility has periodically failed effluent toxicity testing. A Toxicity Identification Evaluation has determined that Diazinon in the effluent is contributing to the observed toxicity. Chlorpyrifos is also implicated as a factor. The City of Denton constructed a half acre experimental wetland to remove Diazinon related toxicity. Results from spiking and microcosm experiments indicate that the wetland can reduce the Diazinon.
Food, Feeding Selectivity, and Ecological Efficiencies of Fundulus notatus (Rafinesque) (Osteichthyes; Cyprinodontidae)
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.
In Vitro Determination of the Cellulose-Decomposing Rates of Twelve Denton County, Texas Soils
In this study twelve types of top soil were collected under aseptic conditions. The cellulose-decomposing rates of these were compared in order to determine the relative rates in the cellulose-decomposing potential of the microorganisms involved. Furthermore, this investigation is designed to acquire pertinent information on the rate at which natural cellulose materials are returned to available plant food.
The Incidence of Colon Bacteria on the Hands of North Texas State Teachers College Students
This investigation has for its aim the determination, in a measure, of the degree of personal sanitation existent among students at North Texas State Teachers College, Denton, Texas.
The Incidence of Escherichia Coli and other Coliform Organisms on Seventy-One Samples of Fresh Fruits and Vegetables Purchased from Eight Grocery Stores in Denton, Texas
This investigation has for its aim the explanation of the incidence of colon bacteria on a number of food samples purchased in grocery stores of Denton, Texas, by an analysis of correlative sanitary factors.
An Investigation of Microbial Antagonism in Ten Denton County, Texas Soils
This thesis is concerned primarily with the growth and detection of soil microorganisms in ten Denton County, Texas, soils antagonistic to a specific gram-positive and a specific gram-negative bacterial organism.
Investigations on Abundance, Habits, and Distribution of Amphibians and Reptiles of Denton County, Texas
The purpose of the present study of the herpetofauna was to obtain additional information regarding the vertebrates of Denton County, and to produce a well-preserved, cataloged collection of the amphibians and reptiles for the Museum of Zoology, North Texas State University. An understanding of the vertebrate life of the county also involves an investigation of the habitats within the county that may, in part, count for the distribution of these animals. It is well recognized that the environmental areas of the county have altered vastly during the last one hundred years. This alteration is due largely to agriculture and industry. However, there are adequate numbers of natural environments, as well as newly created ones that may contribute to the distribution of the vertebrates at the present time. Therefore, the problem not only concerned the collection of specimens, but also the identification, abundance classification, general habitat classifications, and county distribution.
The Isolation and Identification of Micro-Organisms from Spoons of Public Eating Establishments in Denton, Texas
This investigation deals with the isolation and identification of bacteria found on selected samples of spoons in various eating establishments in the vicinity of Denton, Texas.
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).
The Life Cycle of Hydroperla Crosbyi (Needham and Claassen) (Plecoptera: Perlodidae)
Data on the life cycle of Hydropezrla crosbvi were collected from January, 1974, to March, 1976, in Clear Creek, Denton County, Texas. Laboratory investigation helped in establishing instar number, egg incubation and description, and first instar descriptions. Adult Hydroperla crosbyi emerge in February - March when water temperature increases to a mean of 15 C. Eggs undergo a diapause, hatching when decreasing water temperature reaches 18 C in October - November. Maximum growth occurs when water temperatures are coldest. Male and female nymphs undergo ca. 12 and 14 instars, respectively. Larvae of Simuliidae and Chironomidae are the preferred food items of nymphs throughout the growth season.
Microflora Found in a Selected Group of Food Products Enclosed in a Protective Wrapper
The purposes of this study are, first, to determine relative numbers and predominant types of bacterial organisms in the various food products studied; second, to evaluate the efficiency of the paper coverings of these foods; and third, to determine whether these products are potential sources of food poisoning.
Microflora of Frozen Fruits and Vegetables Dispensed from Grocery Stores in Denton, Texas
This investigation was carried out in order to determine whether or not blanching and freezing tends to reduce the incidence of bacteria, particularly those of the coliform group, and also the yeasts and molds.
Parasites of the Cricket Frog, Acris Crepitans, of Denton County, Texas
The purpose of this study was threefold. The literature concerning parasites of A. crepitans was to be brought up to date. Contributions to the general body of knowledge pertaining to the parasitic fauna of host specimens of A. crepitans and specifically those found in Denton County, Texas, were to be made. Finally, specimens found parasitizing host specimens of A. crepitans were to be preserved and classified.
The Phototropic Properties of Lactuca Ludoviciana (Nutt.) DC. and Silphium Laciniatum L.
This paper deals with certain phases of phototropic properties of two exceptional plants, the pertinent behavior of each being decidedly individualistic and in remarkable contrast to that of herbaceous plants in general. The prickly lettuce, Lactuca ludoviciana (Nutt.) DC. and the rosinweed, Silphium laciniatum L., two common Denton County, Texas, plants, have been selected for this study.
Physiological Ecology, Population Genetic Responses and Assemblage Stability of Fishes in Two Southwestern Intermittent Stream Systems
Six sites within the Denton and Hickory Creek watersheds were sampled over three years to assess the impact of seasonal intermittent stream conditions on the ichthyofauna. An integrated approach using field and laboratory techniques was employed to evaluate the responses of the fishes.
Population Dynamics and Community Structure of Mosquitoes (Diptera: Culicidae) Recorded in Denton, Texas from 2005 to 2015
A population survey was conducted on the mosquito species recorded in Denton, Texas for the years of 2005 to 2015. Data used in this project were obtained from an ongoing, long-term surveillance program led by the City of Denton and conducted through the University of North Texas. Research focused on the population dynamics and community structure of mosquitoes collected within urban areas of Denton, Texas in relation to certain environmental variables. A total of 80,837 female mosquitoes were captured and represented 38 species found under the following genera: Aedes, Anopheles, Coquillettidia, Culex, Culiseta, Mansonia, Orthopodomyia, Psorophora, Toxorhynchites, and Uranotaenia. Culex quinquefasciatus was the most abundant species followed by Aedes vexans. Seasonal patterns of the most abundant species revealed high variability throughout the study. Container breeders were most abundant in August and those that breed in floodwaters were most abundant in the months of May and September. Samples were tested for arbovirus presence through the Texas Department of State Health Services in Austin, Texas and multiple pools tested positive for West Nile virus throughout the study. Stepwise multiple regression and Spearman's rank correlation analyses were performed to examine the relationship between the mosquito community and environmental variables. Data revealed that temperature, precipitation, and dew point were the most important variables influencing the mosquito population in the City of Denton.
Population Studies of Ulmus Crassifolia in Flood-Plain Forests of Denton County, Texas
The problem with which this investigation was concerned was the comparison of cedar elm populations in different stands along creeks in Denton County, Texas, and the relationship of certain population parameters to various substrates present at stand sites, Parameters investigated eluded average basal area, basal-area density, transect-segment density, intertree distance, lateral distance, frequency, diameter breast-high, diameter breast-high size-class distribution, and immature-tree density. Variations among populations of Ulmus crassifolia Nutt were noted and analyzed in terms of soil particle size and existing community conditions.
Presence of Krebs Cycle Intermediates in Primary Mycelia of an Actinomycete
The purpose of this study is to determine the presence or absence of a typical Krebs cycle metabolism in the primary mycelia of an aquatic streptomycete.
Primary Productivity and Nutrient Relationships in Garza-Little Elm Reservoir
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.
A Qualitative Survey of the Airborne Algae, Protozoa, and Bacteria at the Denton Sewage Treatment Plant
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. Third, it was hoped that in this research some relationships could be found between the bacteria and the algae and protozoa in the air in the vicinity of the sewage aeration basin. It was hypothesized that pathogenic bacteria were carried in the air with these other organisms.
A Quantitative and Qualitative Bacterial Analysis of Pecan Creek
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.
Sanitary Aspects of the Swimming Pool of North Texas State Teachers College, Denton, Texas
This investigation was conducted in order to show that insanitary conditions may exist in the swimming pool at North Texas State Teachers College provided the proper precautions are not taken; and, in contrast that this pool can be sanitary and entirely safe when operated and used according to the necessary sanitary specifications.
Seasonal Survey of Actinomycetes in Twenty Denton County, Texas, Soils
This investigation has had for its aim a further study of actinomycete flora of twenty Denton County, Texas, soils. The problem has evolved itself into, first, a seasonal analysis for the number of actinomycetes in each of the twenty soils; second, a determination of the types of soils that contain the greatest number of actinomycetes in each cultivated and uncultivated land; third, a determination of soil moisture and pH; and fourth, an attempt to correlate these factors with the number of actinomycetes found in each soil type.
Seasonal Variations in Microflora of Four Denton County, Texas, Clay Soils
This investigation has for its aim the confirmation of the correlation between soil moisture and the microflora of soils, and a lesser relation between the soil temperature and the microflora. The soils used in this study are typical clay soils of Denton County, Texas. The samples were taken from virgin pasture lands and analyses made monthly or semimonthly. The wide seasonal variation of temperature and rainfall afford a good opportunity for this study.
Seasonal Variations in the Microflora of Four Denton County, Texas, Sandy Soils
This investigation has been made to see whether there is a correlation between microorganisms present and the water content and temperature of four Denton County, Texas, sandy soils.
A Solution for High Bacterial Counts in a Local Dairy, Denton, Texas
It is the aim of this investigation to determine through routine checks if the bacterial count in the milk from Brooks Dairy Company is high and if so to determine the source. If it is found that the laboratory plate counts are unnecessarily high, it is the further purpose of this paper to make recommendations for improvements in the quality of milk produced by this dairy plant.
Storm Water Retention Ponds: An Important Source of Aquatic Macroinvertebrate Diversity in a Semi-Arid Urban Landscape of Denton, Texas
The City of Denton, located in a semi-arid region of Texas, has over 200 manmade ponds within its city limits. Many of these ponds, located in densely populated areas, are engineered to control storm water runoff. There is a general lack of recognition of the value these waters contribute to regional biodiversity and as greenspaces. This study, conducted in Denton, is monitoring habitat variables and macroinvertebrate diversity in a series of ponds selected to represent a gradient of urban influences. The objective of this study is to identify the variables associated with the highest diversity. Using drone imagery and a meter square box sampler, the quantitative approach allowed for delineation of three habitat types and area. The macroinvertebrates where identified to the genus level which allowed for higher resolution and resulted in stronger comparisons of the communities and conditions of the ponds. Taxa richness was positively correlated to pond size and trees along shoreline and negatively associated with average depth. Overall, submerged vegetation supported highest diversity and abundance, especially genera of Chironomidae (Diptera). Conductivity was associated with urban influences and the most urban influenced pond had the lowest taxa richness, but also reduced habitat area. Results of this study conclude that these stormwater ponds benefit to the ecology of the city and provide beautiful, green spaces. If managed correctly, these systems can be incorporated into sustainable development in the future of the City of Denton.
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