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open access

A Correlation of the Edaphic Factors with the Vegetation of the Woodbine Sands, Denton County, Texas

Description: The purpose of this study was to correlate the Vegetation of the Woodbine Sands with the edaphic factors. In the laboratory an analysis of the edephic factors was made of the twenty-two soil types collected from the three formations. The results of these and other analysis are shown in tables and graphs. The results indicate that the vegetational cover of an area that is uniform in its origin and in its resident soil factors is determined by the edaphic factors present.
Date: August 1936
Creator: Graham, H. L.
open access

A Correlation of the Vegetation with the Soil Types of Haskell County, Texas

Description: The problem has consisted, first, of a mapping of the soil types present in Haskell County; second, a collection of the existing vegetation of each soil type; third, an identification of the vegetation collected and observed; fourth, and lastly, a comparative study of the vegetation of each soil type in an effort to establish a correlation between the vegetation and the soil type.
Date: 1950
Creator: Tyson, Josiah William, Jr.
open access

The Cultural, Physiological, Morphological and Chemical Characteristics of an Actinomycete from Lake Waco, Texas

Description: The purpose then of this paper has been to expand our knowledge of these aquatic forms by investigating the cultural, physiological, morphological, and chemical characteristics of an actinomycete isolated from the water supply, Lake Waco, of Waco, Texas.
Date: January 1954
Creator: McCormick, William C.
open access

Degradation of Complex Carbon Compounds by Marine Actinomycetes

Description: The purpose of this paper is to present a comparative study of marine bacteria, molds and actinomycetes in regard to their ability to degrade certain pure and mixed complex compounds possibly occurring in the lagoon waste traps of the Texas Gulf Coast. This comparison was made using a differential oxygen uptake as the index of specific compound utilization.
Date: August 1959
Creator: Willingham, Charles Allen
open access

Degradation of Homologous Polymerized Deoxyribonucleic Acid by Azotobacter Vinelandii ATCC 12837

Description: The purpose of this study was twofold. The first was to isolate, purify, and characterize the deoxyribonucleic acid (DNA) of Azotobacter vinelandii ATCO 12837. The second was to determine if there was irreversible binding of homologous 32P labeled DNA to recipient A. vinelandii cells.
Date: August 1972
Creator: Barnes, Wayne Riley
open access

Detection of Mercury Among Avian Trophic Levels at Caddo Lake and Lake Lewisville, TX

Description: Mercury (Hg) is a globally distributed toxicant that has been shown to have negative effects on birds. in the United States, avian taxa have been shown to possess high Hg concentrations in the northeast, Great Lakes and Everglades ecosystems; however, few studies have measured avian Hg concentrations in other geographic regions. Previous studies have documented high Hg concentrations in multiple organisms in east Texas, but birds were not included in these studies. the main objective of the pre… more
Date: May 2012
Creator: Schulwitz, Sarah E.
open access

Determination of Biotransformation and Biodegradation Rate Constants for Naphthalene, Lindane and Phenol

Description: Biotransformation and biodegradation rate constants were determined for naphthalene, lindane, and phenol in water samples from three different sources. Rate constants produced from monitoring disappearance of the parent chemical (biotransformation) were compared to those obtained from mineralization of the chemical (ultimate biodegradation) by ¹⁴CO₂ evolution as well as acidification of the residual ¹⁴C-labeled compound (primary biodegradation). Rate constants were statistically different for t… more
Date: December 1981
Creator: Crawford, Judith Chase
open access

A Determination of the Effects of Various Concentrations of Sodium Chloride upon the Growth of Three Species of Bacteria

Description: The problem in this investigation is to determine the effects of various concentrations of sodium chloride upon the growth of three species of bacteria. An effort has been made to solve this problem, not only by a study of the relevant literature, but also by laboratory research consisting of cultivation and observation of the three organisms which were arbitrarily chosen for this study.
Date: 1942
Creator: Davis, J. Floyd
open access

The Determination of Uptake and Depuration Rate Kinetics and Bioconcentration Factor of Naphthalene and Lindane in Bluegill Sunfish, Lepomis macrochirus

Description: Bluegill were exposed to 3 and 30 pg/L lindane and 20 and 200 pg/L naphthalene to determine uptake rate constants, K1 depuration rate constants, K2, and bioconcentration factors, BCF. Correlations were determined between lipid normalized and non-lipid normalized BCFs, and between observed Kl, K2 and BCFs and predicted values. The K1 values for both chemicals and concentrations were similar. The K2 values were different (1.04 day~1, 0.46 day 1). Naphthalene was more rapid. BCFs for lindane (315)… more
Date: August 1981
Creator: DeFoer, Marguerite J.
open access

Development and Application of an Assessment Protocol for Watershed Based Biomonitoring

Description: With numerous bioassessment methodologies available, a regional protocol needs to be developed to ensure that results are comparable. A regional assessment protocol was developed that includes collecting five benthic macroinvertebrate samples, identifying organisms to genus, and calculating the following metrics: Number of Taxa, Total Number of Individuals, Simpson's Diversity Index, Shannon's Diversity Index, Percent Contribution of Dominant Taxa, Hilsenhoffs Biotic Index, and Percent Contribu… more
Date: May 1998
Creator: Schwartz, Joseph Howard
open access

Development and Validation of a Ramping Treadmill Protocol for the On-Line Measurement of Four Aerobic Parameters

Description: Previously, Whipp et. al. (J. Appl. Physiol.: Respirat. Environ. Exerc. Physiol. 50(1):217-221, 1981) demonstrated the feasibility of determining four parameters of aerobic function, identified as maximum oxygen uptake (μVO_2), VO_2 at anaerobic threshold (θan), the time constant for oxygen uptake kinetics (rVO_2) and work efficiency (η), using a short duration ramped bicycle ergometer exercise test. Because of the importance of being able to measure these parameters on a variety of measurement… more
Date: May 1990
Creator: Cowell, Lynda L. (Lynda Lea)
open access

Development of an In Vitro Protoplast Culture System for Albizia Lebek (L.) Benth., an Economically Important Leguminous Tree

Description: An in vitro system of generating protoplasts from their callus cultures was established. The friable callus was more productive in terms of producing protoplasts than the green compact callus. The concentration of the various cell wall degrading enzymes had an effect on the viability of the protoplasts in the medium. The protoplast system developed from the experiments was stable and could be used for the transformation experiments of Albizia lebek and for other plant improvement practices.
Date: August 1998
Creator: Sinha, Debleena
open access

Development of Range Condition Classes for Coleman County, Texas

Description: This paper deals with a study of the rangelands in Coleman County just west south and west of the Western Cross Timbers of Texas. This problem consists of classifying certain rangelands in this area according to whether they are excellent, fair, good, or poor, the chief basis for which is their deterioration.
Date: June 1951
Creator: McMinn, Philip Morris
open access

Differences in Protein Constituents of Some Azotobacter Species

Description: This study used polyacrylamide gel electrophoresis to study the acid-phenol soluble proteins of five strains (A. vinelandii 12837, A. vinelandii 0, A. chroococcum 8004, A. macrocytogenes 8702, A. tumefaciens) of bacteria grown on Burk's nitrogen-free media, Trypticase Soy Broth, and 0.3% butanol medium. The results showed that the protein patterns can be used for the identification and possibly the taxonomic classification of the Azotobacter. The change of phenotype of the bacteria in different… more
Date: August 1975
Creator: Hsu, Li-Chu Yao
open access

Diphenyloxazole Metabolism by Aryl Hydrocarbon Hydroxylase

Description: 2,5-Diphenyloxazole (PPO) was tested as a potential alternate inducer for the aryl hydrocarbon hydroxylase (AHH) system. Its apparent lack. of carcinogenicity and toxicity provide a possible system for investigation of enzyme systems related to chemical carcinogenesis without exposure of the researcher to potent carcinogenic compounds. These studies found PPO to be an inducer of AHH in cultured human lymphocytes. When PPO was utilized as a substrate for the AHH assay system, the major metabolit… more
Date: December 1976
Creator: Abreu, Mary E.
open access

Distribution of Phosphates in a Sewage Plant and its Receiving Waters

Description: 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.
Date: May 1969
Creator: Hansard, John D.
Location: None
open access

Distribution, Size, Condition, and Food Habits of Selected Fishes in a Reservoir Receiving Heated Effluent from a Power Plant

Description: This study was undertaken in order to provide further insight into the effects of artificial heating on the fisheries of a small reservoir in the Southwest. The following specific objectives were established: (1) to map the reservoir for the distribution of heated water, (2) to determine the distribution of selected species of sports, rough, and forage fish in areas affected by the effluent and in areas not affected, (3) to compare size and condition of selected species of fish from areas affec… more
Date: December 1972
Creator: McNeely, David L.
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