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open access

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-
open access

Size Fractionation of Metabolically Active Phytoplankton and Bacteria in Two Diverse Lentic Systems

Description: Simultaneous size fractionation of plankton populations associated with NaH^14CO_3 and ^3H-glucose uptake was employed in eutrophic Lake Texoma (Texas and Oklahoma) and oligotrophic Flathead Lake (Montana). Autoradiography was utilized to determine the role of specific microorganisms in community metabolism. Ultraplankton (0.45-10 μm) dominated plankton numbers and metabolic activity in both aquatic systems. Many of the most abundant species were not the most productive, in terms of inorganic C… more
Date: August 1980
Creator: Ellis, Bonnie K.
open access

Factors Inhibiting Dissociation Of Neisseria gonorrhoeae Cells

Description: The initial studies reported in this dissertation were attempts to induce mutations in those genes which control dissociation in cells of Nei sseria gonorrhoeae. These studies led to an investigation of survival curves of cells grown in liquid media. Instead of survival curves reflecting the diploid nature of gonococci, multiple cell kinetics were observed. It was found that large clumps contained a predominance of cells of the T2 type and that when these clumps were dispersed by DNAase, it app… more
Date: August 1982
Creator: Gonzalez, Anthony H.
open access

Fungal Antigens and Fungal Disease: An Alkali-Soluble, Water Soluble Antigen from Coccidioides immitis and Coccidioidomycosis

Description: Diagnostic medical mycology has been slow to advance due to a lack of species specific antigens in organisms which cause serious diseases in man. Toward this end, an HPLC analysis was done of the following fungal antigens: histoplasmins HKC-43 and H-42, blastomycin KCB-26, an alkali-soluble, water soluble antigen from Blastomyces dermatitidis (b-ASWS), a coccidioidin prepared from a toluene lysate of the mycelial-arthroconidia phase of Coccidioides immitis, and an alkali-soluble, water-soluble … more
Date: December 1983
Creator: Fleming, William H. (William Harold)
open access

Testing and Evaluation of Environmental Fate Models Using Aquatic Microcosms and Three Organic Chemicals

Description: Two compartment (sediment and water) flow-through model ecosystems were constructed to investigate the compartmentalization of different organic chemicals. Lindane, naphthalene, and mirex were pumped into the systems and resultant compartmental chemical concentrations determined. Steady state concentrations were compared to those predicted by two environmental fate models - EXAMS (Exposure Analysis Modeling System) and SLSA (Simplified Lake and Stream Analysis) which were developed by EPA-Athen… more
Date: December 1983
Creator: Staples, Charles A. (Charles Allen)
open access

Biology and Production of Net-Spinning Caddisflies (Hydropsychidae And Philopotamidae) in a Regulated Portion Of The Brazos River, Texas

Description: Four species of net-spinning caddisflies, Hydropsyche simulans Ross, Cheumatopsyche lasia Ross, Cheumatopsyche campyla Ross and Chimarra obscura (Walker) are common in the regulated portions of the Brazos River. Hydropsyche simulans spun capture nets with the largest meshdimensions; the two Cheumatopsyche species' nets had the next largest meshes, and Chimarra obscura spun nets with the smallest dimensions. Cheumatopsyche lasia and C. campyla constructed nets with similar sized meshes. The numb… more
Date: May 1984
Creator: Malas, Diane M. (Diane Mary)
open access

Comparative Ecology of Benthic Communities in Natural and Regulated Areas of the Flathead and Kootenai Rivers, Montana

Description: A comparative study was made of environmental variables and the density, biomass, diversity, and species composition of macroinvertebrates in areas downstream from a dam with a hypolimnetic release (Hungry Horse Dam on the Flathead River) and a dam with a selective withdrawal system (Libby Dam on the Kootenai River). A major objective of this study was to examine the response of macroinvertebrate communities to defined environmental gradients in temperature, flow, substrate, and food-related va… more
Date: May 1984
Creator: Perry, Sue A.
open access

Genetic and Morphological Variation in Natural Populations of the Red Shiner, Notropis lutrensis, and their Relationship to Adaptation in a Generalist Species

Description: Twenty-two natural populations of the red shiner minnow, Notropis lutrensis were examined for morphological and genetic variation. This research was aimed at testing the hypothesis that morphological and genetic variation was primarily influenced by the degree of gene flow between populations. Ten linear measurements were taken from each of 1320 specimens. Morphological characters were adjusted for differential growth by least squares linear regression techniques. Genetic variability was estima… more
Date: May 1984
Creator: Wooten, Michael Conrad
open access

Studies on the Drumming Behavior of North American Stoneflies (Plecoptera)

Description: Drumming behavior is described for the first time in 16 North American species of Plecoptera, and signals of a 17th species, Isogenoides zionensis, are further detailed. The effective distance over which drumming signals may be transmitted was tested for four communication modes. Results indicate that substratum vibrations are far superior to sound in the transmission of drumming signals, and that dense substrates such as rocks are poor channels for signal transfer. Long communication periods b… more
Date: May 1984
Creator: Zeigler, David D.
open access

Degradation of Humic Substances by Aquatic Bacteria

Description: A variety of aquatic bacteria were isolated and tested for their ability to degrade humic substances and their aromatic residues/monomers which serve as precursors of the trihalomethanes (THMs) found in chlorinated drinking waters. The majority of them were Gram-negative, oxidative types dominated by pseudomonads. Most of the 146 isolates were found to utilize as their sole source of carbon several or more of ten aromatic compounds known to be products of degradation of humus and also to be pre… more
Date: August 1985
Creator: Baiu, Saleh Hamed Salem
open access

Effects of Water Source, Suspended Solids, and Acclimation on Biotransformation of 2 /4-Dichlorophenoxy Acetic Acid in Aquatic Systems

Description: In recent years there has been a great deal of scientific interest in processes that affect the fate of organic chemicals in the environment. one main reason for this increased interest is due to greater environmental concern over accidental or purposeful release of these chemicals into the environment by man. A major environmental concern is the increased use of pesticides over the last few years. In the thirty years prior to 1978 the use of pesticides has increased by a factor of forty (Ridge… more
Date: August 1985
Creator: Moses, Christopher K. (Christopher Karam)
open access

Response of Freshwater and Saltwater Toxicity Test Species to Calcium and Salinity Concentrations Encountered in Toxicity Tests

Description: The responses of freshwater (Daphnia magna. Pimephales promelas) and saltwater (Mysidopsis bahia. Cyprinodon variegatus) toxicity test species to elevated calcium concentrations and changing salinity conditions were investigated. The use of salinity as a criterion for selection between saltwater and freshwater test species was investigated by conducting both calcium and salinity toxicity tests. Salinity was determined to be an inappropriate criterion under conditions encountered in this study.
Date: 1989
Creator: Price, Edmund E., 1954-
open access

Development of a Watershed Prioritization Strategy Using Remote Sensing and the Geographic Resource Analysis Support System. Case study: City of Carrollton, Texas

Description: This study used a geographic information system (GIS) and an empirical pollutant load model to estimate average annual pollutant loads contained in storm water charges from the City of Carrollton, Texas. The Geographic Resource Analyses Support System (GRASS) was used to create a number of spatial data layers as input variables to a model that estimates loads in Kilograms/Hectare/Year, and Kilogram/Basin/Year. Average annual pollutant loads for twelve pollutants were derived from average annual… more
Date: December 1996
Creator: Coffey, Jeffery M. (Jeffery Morgan)
open access

Systematics of the Stonefly Tribe Suwalliini Surdick and Behavioral Studies of Selected Species in the Stonefly Families Chloroperlidae and Perlidae

Description: The purpose of this study is to revise the genus Suwallia and to evaluate the potential taxonomic importance of adeagal and other genitalic characters, adult pigment patterns and egg characters. The revision concentrates on western North American species while providing coverage of all species, except Suwallia asiatica Zhiltzova and Lavanidova where only presumed females have been available for study. Communication and mate locating behaviors in adult stoneflies are critical for life cycle comp… more
Date: August 1997
Creator: Alexander, Kevin D. (Kevin Dewayne)
open access

Advanced Molecular and Microbial Techniques: a Complete Laboratory Notebook

Description: The purpose of this project is to produce a complete and thorough notebook that may be used to supplement laboratory coursework. Its intent is to be used primarily by the students to aid them in understanding background information and the proper laboratory procedures involved in various types of experiments. The laboratory notebook is a summation of all the experiments and procedures used in the six-credit hour Advanced Microbial and Molecular Biology (BIOL 5160) course offered during the summ… more
Date: May 1998
Creator: Brito-Rodriquez, Carmen Lydia
open access

Ecological Association Between the Red-Cockaded Woodpecker and Southern Pine Beetle in the Homochitto National Forest: a Geographic Information System Approach

Description: Since the introduction of management practices by the Forest Service to stabilize red-cockaded woodpecker (RCW) populations, the number of cavity trees killed by southern pine beetles (SPB) has increased. A model of the landscape ecology of RCW and SPB in the Homochitto National Forest was created using data collected from the Forest Service and Global Atmospherics. The conclusions of the study were that the RCW and SPB utilize the same type of habitat and the stand hazard maps are an accurate … more
Date: December 1998
Creator: Skordinski, Karen R. (Karen Renee)
open access

Pretreatment Optimization of Fiberglass Manufacturing Industrial Wastewater

Description: Wastewater effluent produced in the fiberglass manufacturing industry contains a significant amount of total suspended solids. Environmental regulations require pretreatment of effluent before it is discharged to the municipal wastewater treatment plant. Chemical precipitation by coagulation and flocculation is the method of pretreatment used at the Vetrotex CertainTeed Corporation (VCT). A treatability study was conducted to determine conditions at which the VCT Wastewater Pretreatment Plant c… more
Date: December 1998
Creator: Dragoo, Ron

Submerged wood inhabiting macoinvertebrates of the Elm Fork of the Trinity River, Texas: Assemblage analyses, comparisons to the benthic fauna, and a study of Cyrnellus fraternus (Trichoptera: Polycentropodidae)

Description: Taxonomic composition and spatio-temporal variability of macroinvertebrates inhabiting snags were examined from an 8-km segment of the Elm Fork of the Trinity River. Seventy-seven macroinvertebrate taxa were collected from submerged wood during the study. Assemblages were highly variable spatially and temporally, especially among seasons. An ordination of species and environment did not find snag taxa to have striking correlations with many of the selected environmental variables, although ther… more
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Date: August 2001
Creator: Johnson, Zane B.
open access

Insulin-Like Signaling and Tissue-Specific Requirements of Anoxia Survival in Caenorhabditis elegans

Description: Paper examines the soil nematode Caenorhabditis elegans, an organism which can normally survive a day of anoxia (oxygen deprivation) and longer with mutations in the daf-2/daf-16 pathway. Examines how these mutations affect anoxia survival and the potential benefit to the development of anoxia-related therapies in humans.
Date: 2009
Creator: Pavlyukovskyy, Mark
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