States

Biochemical Genetics of the Pocket Gopher Genus Geomys, and its Phylogenetic Implications (open access)

Biochemical Genetics of the Pocket Gopher Genus Geomys, and its Phylogenetic Implications

Electrophoretic techniques were utilized for the demonstration of variation in 22 proteins from 24 natural populations of four species ( G. bursarius, G. pinetis, G. arenarius and G. personatus ) of the Geomys complex of pocket gophers. Of the 24 structural loci , 19 were considered to be polymorphic. Five of the six esterases contributed greatested to the polymorphism while non-esterase proteins generally showed low values. In the GeoMys complex of pocket gophers in this study,selection appeared to be the most important influence on genetic structure with some evidence of random drift in two of the four species. Populations of G. arenarius and G. personatus had the highest average interspecific genetic similarities to G. bursarius and . pinetis was the most divergent. Biochemical evidence supports the phylogeny of Geomys based on morphological and fossil data.
Date: December 1974
Creator: Penney, Dan F.
System: The UNT Digital Library
Ecological Energetics of the Dobson Fly, Corydalus Cornutus (open access)

Ecological Energetics of the Dobson Fly, Corydalus Cornutus

Rates and energies of consumption (C), egestion (F), assimilation (A), respiration (R), growth (Pg), production of exuviae (Pev), and production of egg masses (Pr) and associated efficiencies, and the effects of seasonal temperature, weight and metamorphic stage upon these factors were examined for a typical individual and cohort of Corydalus cornutus (L.) from a stream in North-Central Texas (330 23'N, 97*5'W). Dobson flies are apparently univoltine in the study area, with 11 larval instars. Emergence, oviposition and hatching occur from late May to August. The typical dobson fly hatches in mid-June, grows rapidly until November, and resumes rapid growth in March, reaching full adult size prior to leaving the stream to pupate in early June. Adult females must feed to provide energy to yolk eggs, produce egg-mass coverings and continue somatic maintenance during their week of reproductive endeavors. Metabolic compensation enables larval dobson flies to maintain preferred and fairly constant rates of R during winter (201-451 pl g-1 h~1; 5-15 C) and summer (985-1173 pl g- h1; 20-30 C); with a seasonal acclimatization change point between 15-20 C. Reduction of rates of R through undercompensation during the winter when food is scarce and through partial compensation at high temperatures during …
Date: December 1974
Creator: Brown, Arthur V.
System: The UNT Digital Library
Microbiological Treatment of Wastewater from a Wood-Preserving Plant (open access)

Microbiological Treatment of Wastewater from a Wood-Preserving Plant

This research investigates interacting biological, chemical, and physical factors affecting the efficiency of microbiological wastewater treatment at the W. J. Smith Wood- Preserving Company in Denison, Texas. The treatment process consisted of collecting exhaust boiler water containing unidentified boiler treatment compounds, steam condensate contaminated with preservatives and wood extracts, plant process waters, and rainfall runoff from plant grounds. With a 5-minute residence time, wastewater was passed over 2 oxidation towers in series, each containing approximately 47,000 square feet of surface area. Suspended solids were removed from the wastewater before discharge. Various amino acids such as serine, aspartate, cysteine, phenylalanine, alanine, proline, glycine, histidine, and tyrosine significantly stimulated phenol degradation in the laboratory. The plant wastewater contained approximately 0.1 mg/l of several of the stimulatory amino acids. It was assumed that these concentrations provided maximal stimulation in the field situation. The plant wastewater also contained sufficient nitrogen to permit the organisms to degrade up to 100 mg phenol/1 of water examined. Amino acids in the wastewater probably serve as a source of microbial nutrition. Toxicity of the wastewater to fish was not caused by the presence of phenol, phenol degradation products, or traces of pentachlorophenol. The wastewater was rendered non-toxic by …
Date: August 1974
Creator: Ralston, James R.
System: The UNT Digital Library
Biochemical Genetics of Certain Species of the Blackbird Family Icteridae (open access)

Biochemical Genetics of Certain Species of the Blackbird Family Icteridae

Starch gel electrophoresis was used to compare 14 proteins encoded by 15 loci for seven species of the family Icteridae. A close genetic relationship among these species was classified into three groups. The Agelaiine group contained Agelaius phoeniceus, Sturnella magna, and S. neglecta. The Quiscaline group contained Euphagus cyanocephalus, Cassidix mexicanus, and Quiscalus quiscula. Molothrus ater, the most divergent, was placed in a separate group. Divergence times for the seven species were compared to the literature. Heterozygosity of the seven populations of the two species of Sturnella were compared to determine factors influencing their divergence. Two factors proposed were heterosis in S. neglecta and possible hybridization between S. neglect and S. magna.
Date: December 1974
Creator: Smith, Jackson Kelly
System: The UNT Digital Library
Effects of Turbidity on Gilling Rates and Oxygen Consumption on Green Sunfish, Lepomis cyanellus (open access)

Effects of Turbidity on Gilling Rates and Oxygen Consumption on Green Sunfish, Lepomis cyanellus

Laboratory studies conducted at 5, 15, 25, and 35 C measured changes in gilling rates and oxygen consumption of green sunfish in response to exposure to bentonite clay suspensions. The tests indicate that gilling rates are not affected by bentonite clay suspensions below 2125 FTU at 5 C, 1012 FTU at 15 C, and 898 FTU at 25 C. At turbidity levels exceeding 1012 FTU at 15 C and 898 at 25 C, gilling rates increased 50-70%. Tests were inconclusive at 35 C. Oxygen consumption rates were found to be unaffected by turbid suspensions below 3500 FTU at all four temperatures. Evidence suggests that increased gilling rates under highly turbid conditions are a means of compensating for reduced respiratory efficiency and a strategy for maintaining a constant oxygen uptake. Evidence indicates that the cost of increased gilling rates is probably met by a reduction in activity.
Date: May 1974
Creator: Horkel, John Duane
System: The UNT Digital Library
The Distribution of Pathogenic Pseudomonas aeruginosa in Sewage (open access)

The Distribution of Pathogenic Pseudomonas aeruginosa in Sewage

The purpose of this study was to extend our understanding of the ecological relationships of P. aeruginosa by investigating the differences or similarities between the strains of this organism found in sewage and those found as pathogens in human infections. This research was approached by comparing the serological types of P. aeruginosa isolated from sewage contaminated waters in Argentina (South America) to those isolated from sewage contaminated waters in Texas. They were typed with sera obtained using P. aeruginosa isolated from human infections. The data obtained revealed that bacteria isolated from sewage in Texas and from soil and water in Argentina are antigenically similar to those isolated from human infections.
Date: May 1974
Creator: Labay, Joseph Edward
System: The UNT Digital Library