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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

Effects of Long-Term Moderate Ethanol Intake on the Stress Response in Rats

Description: The effect of ethanol on the stress response in rats was examined. Experimental animals were given 0.25 ml of 28 percent ethanol or 0.25 ml of water orally once a day, five days a week, for a period of twelve months and were then subjected to fifteen minute cold stress. Corticosterone levels in ethanol-treated males following stress were significantly lower (22 percent) than in the sham group. Adrenal weights in sham-treated females were significantly higher (15 percent) than in the ethanol gro… more
Date: December 1984
Creator: Williams, Judy L. (Judy Lee)
open access

Fate of Endothall in Aquatic Environments

Description: Hazard assessment of pesticides in aquatic environments requires accurate predictions of persistence and compartmentalization. A strategy for developing confidence in predictive fate models, such as the Exposure Analysis Modeling System (EXAMS) and the Simplified Lake and Stream Analysis model (SLSA), is to test the models using carefully chosen chemicals in semi-controlled and field situations. An objective of this approach would be to isolate the variability in a particular fate process and t… more
Date: December 1984
Creator: Reinert, Kevin H. (Kevin Howard)
open access

Life History Energetics of The Red-Eared Turtle, Pseudemys scripta in North Central Texas

Description: A population of the red-eared slider, Pseudemys scripta, in north central Texas was studied from 1975 to 1980. A life history energy budget was developed for a typical individual in the population and the population dynamics were estimated. A growth model relating growth rate to mean plastron length (PL) was developed from recapture data and used to 1) establish age classes and 2) age individuals. Growth rate was highly variable in both sexes. Females grew more rapidly than males and attained a… more
Date: December 1984
Creator: Glidewell, Jerry Ray, 1945-
open access

Qualitative and Microcosm Predictions of Effects of Endothal for Control of Myriophyllum spicatum in Pat Mayse Lake, Texas

Description: Qualitative and microcosm models were used to predict effects of herbicide application for control of Myriophyllum spicatum. Predictions were compared to data from Pat Mayse Lake, a Texas reservoir, where localized areas were treated with endothall. Although milf oil was temporarily eliminated, when endothall was used according to manufacturer's directions, no ecologically significant direct or indirect effects were observed on nontarget species or abiotic water quality. Comparisons of the pred… more
Date: May 1984
Creator: Hinman, Mark L.
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

A Study of Polynuclear Aromatic Hydrocarbon Carcinogen Transport and Deoxyribonucleic Acid Repair

Description: This investigation addresses the interrelated problems of A) Uptake and vascular transport of lipophilic chemical carcinogens, and intracellular interactions between lipoproteins and carcinogens; B) Biochemical mechanisms by which polynuclear aromatic hydrocarbon carcinogens inhibit the replicative and repair DNA synthesis in cells. The results observed in this study suggest that ingested benzo(a)pyrene (BaP) enters the gastrointestinal lymphatic drainage sequestered within lymphatic lipoprotei… more
Date: December 1984
Creator: Joe, Cheol O., 1949-
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