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Publications

Read publications and other informational products to learn more about USGS science occurring in the Mississippi Basin.

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Determination of selection gradients using multiple regression versus Structural Equation Modeling (SEM) Determination of selection gradients using multiple regression versus Structural Equation Modeling (SEM)

Selection studies involving multiple intercorrelated independent variables have employed multiple regression analysis as a means to estimate and partition natural and sexual selection's direct and indirect effects. These statistical models assume that independent variables are measured without error. Most would conclude that such is not the case in the field studies for which these...
Authors
B.H. Pugesek, A. Tomer

A highly conserved N-terminal sequence for teleost vitellogenin with potential value to the biochemistry, molecular biology and pathology of vitellogenesis A highly conserved N-terminal sequence for teleost vitellogenin with potential value to the biochemistry, molecular biology and pathology of vitellogenesis

N-terminal amino acid sequences for vitellogenin (Vtg) from six species of teleost fish (striped bass, mummichog, pinfish, brown bullhead, medaka, yellow perch and the sturgeon) are compared with published N-terminal Vtg sequences for the lamprey, clawed frog and domestic chicken. Striped bass and mummichog had 100% identical amino acids between positions 7 and 21, while pinfish, brown...
Authors
L.D. Folmar, N. D. Denslow, R.A. Wallace, G. LaFleur, T. S. Gross, S. Bonomelli, C.V. Sullivan

Toxicity of crude oil to the mayfly, Hexagenia bilineata (Ephemeroptera: Ephemeridae) Toxicity of crude oil to the mayfly, Hexagenia bilineata (Ephemeroptera: Ephemeridae)

Effects of crude oil on survival and behavior of the mayfly Hexagenia bilineata were evaluated in laboratory studies. Mayfly nymphs were exposed to the water soluble and oil residue fractions of crude oil. Mayfly survival was not reduced by a 96-h exposure to either the water soluble fraction or the oil residue mixed with sediment. However, significant mortality did result from a 21-day...
Authors
Mark P. Ort, Susan E. Finger, John R. Jones

Use of semipermeable membrane devices (SPMDS) to determine bioavailable organochlorine pesticide residues in streams receiving irrigation drainwater Use of semipermeable membrane devices (SPMDS) to determine bioavailable organochlorine pesticide residues in streams receiving irrigation drainwater

The semipermeable membrane device (SPMD), consisting of a neutral lipid (triolein) enclosed in polyethylene layflat tubing, is very effective in sequestering bioavailable organochlorine (OC) pesticides in the environment. We used SPMDs to sequester OC pesticide residues in streams receiving irrigation drainwater and found toxaphene, the DDT complex, dieldrin, and endrin. Ambient water
Authors
Jimmie D. Petty, James N. Huckins, D.B. Martin, T.G. Adornato

An alternative bacteriological medium for the isolation of Aeromonas spp. An alternative bacteriological medium for the isolation of Aeromonas spp.

Two solid bacteriologic media were compared for cultivating Aeromonas spp. from piscine sources: the Rimler-Shotts (RS) medium and a starch-glutamate-ampicillin-penicillin-based medium (SGAP-10C) used for the recovery of Aeromonas spp. from water samples. The selective and differential capacities of the media were assessed March through October 1992 by recovery rate and phenotype of 99...
Authors
J.A. Jenkins, P.W. Taylor

The effects of vertebrate herbivory on plant community structure in the coastal marshes of the Pearl River, Louisiana, USA The effects of vertebrate herbivory on plant community structure in the coastal marshes of the Pearl River, Louisiana, USA

In this study, we investigated the impacts of herbivory by the introduced aquatic herbivore, nutria (Myocastor coypus), on three marsh communities of the Pearl River using fenced exclosures and control plots. Although total community above-ground biomass was reduced by 30% in the plots exposed to herbivory as compared to those protected from herbivory, we found species richness to be...
Authors
K.L. Taylor, J.B. Grace

Brown trout avoidance of metals in water characteristic of the Clark Fork River, Montana Brown trout avoidance of metals in water characteristic of the Clark Fork River, Montana

The avoidance response of brown trout (Salmo trutta) to mixtures of cadmium, copper, lead, and zinc was determined in water simulating the Clark Fork River, Montana. Effects of acidification on the avoidance response were also evaluated. Tests were conducted in a cylindrical chamber that received reference water at one end and metal-contaminated water at the other; a distinct boundary...
Authors
Daniel F. Woodward, James A. Hansen, Harold L. Bergman, Aaron J. Delonay, Edward E. Little

Magnitude and frequency of peak discharges for Mississippi River Basin Flood of 1993 Magnitude and frequency of peak discharges for Mississippi River Basin Flood of 1993

The magnitude and frequency of the 1993 peak discharges in the upper Mississippi River Basin are characterized by applying Bulletin 17B and L-moment methods to annual peak discharges at 115 unregulated watersheds in the basin. The analysis indicated that the 1993 flood was primarily a 50-year or less event on unregulated watersheds less than about 50,000 km2 (20,000 mi2). Of the 115...
Authors
W.O. Thomas, D. A. Eash

Urban stormwater runoff study at Davenport, Iowa Urban stormwater runoff study at Davenport, Iowa

Urban storm water runoff is being investigated as a nonpoint source of pollution across the country as urban areas with populations over 100,000 conduct studies designed to meet U.S. Environmental Protection Agency guidelines for National Pollutant Discharge Elimination System permits for their stormwater discharges. From 1991 through 1994, the City of Davenport, Iowa (fig. 1), and the U...
Authors
Bryan D. Schaap

Hazard assessment of inorganics to three endangered fish in the Green River, Utah Hazard assessment of inorganics to three endangered fish in the Green River, Utah

Acute toxicity tests were conducted with three life stages of Colorado squawfish (Ptychocheilus lucius), razorback sucker (Xyrauchen texanus), and bonytail (Gila elegans) in a reconstituted water quality simulating the middle part of the Green River of Utah. Tests were conducted with boron, lithium, selenate, selenite, uranium, vanadium, and zinc. The overall rank order of toxicity to...
Authors
S. J. Hamilton
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