Publications
Publications from USGS science centers throughout the Southeast Region.
Filter Total Items: 10386
Conservation of aquatic karst Biotas: shedding light on troubled waters Conservation of aquatic karst Biotas: shedding light on troubled waters
No abstract available.
Authors
Stephen J. Walsh
Use of semipermeable membrane devices (SPMD) to assess occurrence and estimate water concentrations of selected organic compounds in the Rio Grande from Presidio to Brownsville, Texas Use of semipermeable membrane devices (SPMD) to assess occurrence and estimate water concentrations of selected organic compounds in the Rio Grande from Presidio to Brownsville, Texas
In Texas, the Rio Grande forms the international boundary between Mexico and the United States and extends about 2,000 kilometers from El Paso to the mouth of the Rio Grande just south of Brownsville, where the river flows into the Gulf of Mexico (fig. 1). The North American Free Trade Agreement (NAFTA) has resulted in increased industrialization and population growth on both sides of...
Authors
J. Bruce Moring
Estimation of minimum 7-day, 2-year discharge for selected stream sites, and associated low-flow water-quality data, southeast Texas, 1997-98 Estimation of minimum 7-day, 2-year discharge for selected stream sites, and associated low-flow water-quality data, southeast Texas, 1997-98
The U.S. Geological Survey (USGS) operates a network of streamflow-gaging stations in Texas that provides discharge data used for water-management decisions and various other purposes. Operating stations at all locations where discharge data are needed is not feasible, but the statistical characteristics of the network station data can be used to estimate discharge characteristics at...
Authors
Jeffery W. East
Agrichemicals in ground water of the midwestern USA: Relations to soil characteristics Agrichemicals in ground water of the midwestern USA: Relations to soil characteristics
A comprehensive set of soil characteristics were examined to determine the effect of soil on the transport of agrichemicals to ground water. This paper examines the relation of local soil characteristics to concentrations and occurrence of nitrate, atrazine (2-chloro-4 ethylamino-6-isopropylamino-s-trazine), and atrazine residue [atrazine + deethylatrazine (2-amino-4-chloro-6...
Authors
M. R. Burkart, D.W. Kolpin, R.J. Jaquis, K.J. Cole
Effects of environmental change on plant species density: Comparing predictions with experiments Effects of environmental change on plant species density: Comparing predictions with experiments
Ideally, general ecological relationships may be used to predict responses of natural communities to environmental change, but few attempts have been made to determine the reliability of predictions based on descriptive data. Using a previously published structural equation model (SEM) of descriptive data from a coastal marsh landscape, we compared these predictions against observed...
Authors
L. Gough, J.B. Grace
Cytochrome P4501A induction, benzo[a]pyrene metabolism, and nucleotide adduct formation in fish hepatoma cells: Effect of preexposure to 3,3',4,4',5-pentachlorobiphenyl Cytochrome P4501A induction, benzo[a]pyrene metabolism, and nucleotide adduct formation in fish hepatoma cells: Effect of preexposure to 3,3',4,4',5-pentachlorobiphenyl
In PLHC-1 hepatoma cells, benzo[a]pyrene (B[a]P) caused a maximum induction of cytochrome P4501A (CYP1A) activity, measured as ethoxyresorufin O-deethylation (EROD), after 4 to 8 h of exposure, depending on the B[a]P concentration. The decline of EROD activity at longer exposure times was probably caused by the rapid metabolism of B[a]P in this system (57% metabolism within 4 h...
Authors
J.M.W. Smeets, A. Voormolen, D. E. Tillitt, J.M. Everaarts, W. Seinen, Vanden Berg
Channel catfish response to ultraviolet-B radiation Channel catfish response to ultraviolet-B radiation
Fingerling channel catfish Ictalurus punctatus exposed to simulated ultraviolet-B radiation at an average daily dose of 2.9 J/cm2 were quite sensitive to the radiation. After a 24-h exposure, thinning of the most dorsal epidermis frequently was accompanied by edema. Compared with epidermis of unexposed fish, mucous cells in exposed fish were less superficial and club cells were less...
Authors
M. S. Ewing, V. S. Blazer, D. L. Fabacher, E. E. Little, K. M. Kocan
Geographic distribution: Ambystoma talpoideum (Mole salamander) Geographic distribution: Ambystoma talpoideum (Mole salamander)
No abstract available.
Authors
C. Kenneth Dodd, Marian L. Griffey
Individual-based models in ecology: An overview Individual-based models in ecology: An overview
No abstract available.
Authors
Donald L. DeAngelis, D. M. Fleming, L.J. Gross, W.F. Wolff
MOAB: a spatially explicit, individual-based expert system for creating animal foraging models MOAB: a spatially explicit, individual-based expert system for creating animal foraging models
We describe the development, structure, and corroboration process of a simulation model of animal behavior (MOAB). MOAB can create spatially explicit, individual-based animal foraging models. Users can create or replicate heterogeneous landscape patterns, and place resources and individual animals of a goven species on that landscape to simultaneously simulate the foraging behavior of...
Authors
J. Carter, John T. Finn
Removal of organic contaminant toxicity from sediments - Early work toward development of a toxicity identification evaluation (TIE) method Removal of organic contaminant toxicity from sediments - Early work toward development of a toxicity identification evaluation (TIE) method
Work was performed to determine the feasibility of selectively detoxifying organic contaminants in sediments. The results of this research will be used to aid in the development of a scheme for whole-sediment toxicity identification evaluations (TIEs). The context in which the method will be used inherently restricts the treatments to which the sediments can be subjected: Sediments...
Authors
J.A. Lebo, J.N. Huckins, J. D. Petty, K.T. Ho