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Full-Text Articles in Natural Resources Management and Policy

Predicting Modes Of Toxic Action From Chemical Structure: Acute Toxicity In The Fathead Minnow (Pimephales Promelas), Steven P. Bradbury, Christine L. Russom, Steven J. Broderius, Dean E. Hammermeister, Robert A. Drummond May 1997

Predicting Modes Of Toxic Action From Chemical Structure: Acute Toxicity In The Fathead Minnow (Pimephales Promelas), Steven P. Bradbury, Christine L. Russom, Steven J. Broderius, Dean E. Hammermeister, Robert A. Drummond

Steven P. Bradbury

In the field of aquatic toxicology, quantitative structure-activity relationships (QSARs) have developed as scientifically credible models for predicting the toxicity of chemicals when little or no empirical data are available. In recent years, there has been an evolution of QSAR development and application from that of a chemical-class perspective to one that is more consistent with assumptions regarding modes of toxic action. The objective of this research was to develop procedures that relate modes of acute toxic action in the fathead minnow (Pimephales promelas) to chemical structures and properties. An empirically derived database for diverse chemical structures of acute toxicity …


Acute Toxicity And Behavioral Effects Of Chlorpyrifos, Permethrin, Phenol, Strychnine, And 2,4-Dinitrophenol To 30-Day-Old Japanese Medaka (Oryzias Latipes), Steven P. Bradbury, Patricia J. Rice, Charles D. Drewes, Theresa M. Klubertanz, Joel R. Coats Apr 1997

Acute Toxicity And Behavioral Effects Of Chlorpyrifos, Permethrin, Phenol, Strychnine, And 2,4-Dinitrophenol To 30-Day-Old Japanese Medaka (Oryzias Latipes), Steven P. Bradbury, Patricia J. Rice, Charles D. Drewes, Theresa M. Klubertanz, Joel R. Coats

Steven P. Bradbury

Five chemicals with different modes of action were evaluated in laboratory studies to determine their acute toxicity (48-h median lethal concentration [LC50]) and behavioral effects on 30-d-old Japanese medaka (Oryzias latipes). The order of toxicity for these xenobiotics was permethrin > chlorpyrifos > 2,4-dinitrophenol (2,4-DNP) > strychnine > phenol. The 48-h LC50s were significantly different and ranged from 0.011 to 24.1 mg/L. In addition, chlorpyrifos and permethrin accumulated in the tissues of juvenile O. latipes. Observations of five behavioral/morphological responses, including changes in equilibrium, general activity, startle response, and morphology (e.g., hemorrhage and deformities) were used as indicators of sublethal toxicity. Each chemical, with …


A Computationally-Based Hazard Identification Algorithm That Incorporates Ligand Flexibility. 1. Identification Of Potential Androgen Receptor Ligands, Steven P. Bradbury, Ovanes Mekenyan, Julian Ivanov, Stoyan Karabunarliev, Gerald T. Ankley, Walter Karcher Jan 1997

A Computationally-Based Hazard Identification Algorithm That Incorporates Ligand Flexibility. 1. Identification Of Potential Androgen Receptor Ligands, Steven P. Bradbury, Ovanes Mekenyan, Julian Ivanov, Stoyan Karabunarliev, Gerald T. Ankley, Walter Karcher

Steven P. Bradbury

To advance techniques for screening large data sets of diverse structures for toxicologically active compounds, an algorithm was developed that is not dependent upon a predetermined and specified toxicophore or an alignment of conformers to a lead compound. Instead, the approach provides the means to identify and quantify specific global and local stereoelectronic characteristics associated with active compounds through a comparison of energeticallyreasonable conformer distributions for specific descriptors. To illustrate the algorithm, the stereoelectronic requirements associated with the binding affinity of 28 steroidal and non-steroidal ligands to the androgen receptor were defined. Common ranges of interatomic distances, atomic charges, and …


Influence Of Geographic Origin And Soil Properties On Color Of Black Walnut Veneer, Douglas D. Stokke, Edward C. Workman Jr., John E. Phelps, Felix Ponder Jr. Jan 1997

Influence Of Geographic Origin And Soil Properties On Color Of Black Walnut Veneer, Douglas D. Stokke, Edward C. Workman Jr., John E. Phelps, Felix Ponder Jr.

Douglas D. Stokke

Walnut veneer frorn sites in Missouri, Illinois, and Indiana was analyzed for color attributes and chemical properties. Veneer color also was compared to an industry color standard. Soil chemical and physical properties were measured on selected sites in each state. In general, walnut trees grown on soils with equal proportions of sand, silt, and clay have better veneer color attributes than trees grown on soils with high clay I sand or clay I silt ratios.