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Full-Text Articles in Physical Sciences and Mathematics

Cavefish Population Status And Environmental Quality In Cave Springs Cave, Arkansas - Final Report Submitted To Arkansas Natural Heritage Commission, G. O. Graening, Arthur V. Brown Aug 1999

Cavefish Population Status And Environmental Quality In Cave Springs Cave, Arkansas - Final Report Submitted To Arkansas Natural Heritage Commission, G. O. Graening, Arthur V. Brown

Technical Reports

This report summarizes the continuing effort to monitor environmental quality in the Cave Springs Cave Natural Area and to implement the Ozark Cavefish Recovery Plan. Last year’s report (Brown et al., 1998) identified certain environmental stressors, including a trend over 15 years of increasing nutrient pollution, a low cavefish population count of only 106, and the presence of heavy metals in the cave water and one semi-volatile organic compound (the phthalate DEHP at 500 ppb) in resident crayfish tissue. This year’s monitoring effort demonstrates that fecal coliforms continue to exceed Arkansas State Water Quality Standards (Regulation 2), sometimes by a …


Influence Of Nitrogen Rate And Sampling Date On Soil Analysis Values Of Highbush Blueberries, John R. Clark, Ronald W. Mcnew, Richard C. Maples Jun 1999

Influence Of Nitrogen Rate And Sampling Date On Soil Analysis Values Of Highbush Blueberries, John R. Clark, Ronald W. Mcnew, Richard C. Maples

Research Reports and Research Bulletins

Three studies were conducted on nitrogen (N) fertilization effects on soil of highbush blueberries in Arkansas. Objectives included: 1) determination of varying N rate effects on the standard soil analysis variables, 2) determination of date of soil sampling effects on soil analyses, 3) evaluation of the interactions of N rate and time of sampling, and 4) determination of changes in soil content over years. This research was done in two of the more important highbush blueberry production areas in Arkansas: the Arkansas River Valley where blueberries are grown on sandy loam soils, and northwest Arkansas where production is more common …


Arkansas Soil Fertility Studies 1998, Wayne Sabbe Mar 1999

Arkansas Soil Fertility Studies 1998, Wayne Sabbe

Arkansas Agricultural Experiment Station Research Series

Rapid technological changes in crop management and production require that the research efforts also be presented in an expeditious manner. The contributions of soil fertility and fertilizers are major production factors in all Arkansas crops. The studies contained within will allow producers to compare their practices with the university’s research efforts. Additionally, soil test data and fertilizer sales are presented to allow comparisons among years, crops, and other areas within Arkansas.


Analysis Of Phytoestrogens By High Performance Liquid Chromatography, Anne A. Grippo, Yan Xie, Benjamin L. Rougeau, William V. Wyatt Jan 1999

Analysis Of Phytoestrogens By High Performance Liquid Chromatography, Anne A. Grippo, Yan Xie, Benjamin L. Rougeau, William V. Wyatt

Journal of the Arkansas Academy of Science

Phytoestrogens are biochemicals synthesized in plants which mimic steroidal estrogen activity in mammals. Analysis of these compounds in the legumes which produce them and in body fluids is important to the study of their physiological effects. High pressure liquid chromatography (HPLC) has been found to be an efficient and sensitive method of identification and quantitation of isoflavonoids, one class of phytoestrogen. Here we report the separation of three isoflavonoids, biochanin A, genistein and daidzein using an HPLC system with a Cg reverse phase column and a linear gradient mobile phase containing acetonitrile and acetic acid/water (10/90, v/v) over 60 minutes. …


Effects Of Predation On Two Species Of Stream-Dwelling Crayfish (Orconectes Marchandi And Cambarus Hubbsi) In Pool And Riffle Microhabitats, Heidi Dukat, Daniel D. Magoulick Jan 1999

Effects Of Predation On Two Species Of Stream-Dwelling Crayfish (Orconectes Marchandi And Cambarus Hubbsi) In Pool And Riffle Microhabitats, Heidi Dukat, Daniel D. Magoulick

Journal of the Arkansas Academy of Science

Community structure may be governed by many abiotic and biotic factors. Of the biotic factors, predation is often considered to be critical in structuring freshwater stream communities. In the Warm Fork of the Spring River, the crayfish Cambarus hubbsi is found mainly in riffles, whereas the crayfish Orconectes marchandi is found in high numbers in pools. We hypothesized that predation, mainly by fish, is a factor causing this segregation. Higher predation rates for C. hubbsi than 0. marchandi in the pools and higher predation rates for 0. marchandi than C. hubbsi in the riffles were expected. A transplant tethering experiment …