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Changes in herbicide concentrations in Midwestern streams in relation to changes in use, 1989-1998
E.A. Scribner, W.A. Battaglin, D. A. Goolsby, E.M. Thurman
2000, Science of Total Environment (248) 255-263
Water samples were collected from Midwestern streams in 1994–1995 and 1998 as part of a study to help determine if changes in herbicide use resulted in changes in herbicide concentrations since a previous reconnaissance study in 1989–1990. Sites were sampled during the first significant runoff period after the application of...
Landscape-based spatially explicit species index models for everglades restoration
J. L. Curnutt, J. Comiskey, M.P. Nott, L.J. Gross
2000, Ecological Applications (10) 1849-1860
As part of the effort to restore the ∼10 000-km2 Everglades drainage in southern Florida, USA, we developed spatially explicit species index (SESI) models of a number of species and species groups. In this paper we describe the methodology and results of three such models: those for the Cape Sable Seaside Sparrow...
Utility of palmatolepids and icriodontids in recognizing Upper Devonian Series, Stage, and possible substage boundaries
W. Ziegler, Charles Sandberg
2000, CFS Courier Forschungsinstitut Senckenberg 335-347
Conodonts are accepted internationally to define Devonian Series and Stage boundaries. Hence, the evolution and taxonomy of pelagic palmatolepids, primarily Palmatolepis and its direct ancestor Mesotaxis, and shallow-water icriodontids, Icriodus, Pelekysgnathus, and "Icriodus", are the major tools for recognizing subdivisions of the Upper Devonian. Palmatolepids are the basis for the...
White-tailed deer (Odocoileus virginianus) predation on grassland songbird nestlings
P.J. Pietz, D. A. Granfors
2000, American Midland Naturalist (144) 419-422
White-tailed deer (Odocoileus virginianus) were videotaped depredating four songbird nests in grassland habitats in southeastern and northcentral North Dakota, 1996–1999. Deer ate two Savannah sparrow (Passerculus sandwichensis), two grasshopper sparrow (Ammodramus savannarum), one clay-colored sparrow (Spizella pallida), one red-winged blackbird (Agelaius phoeniceus) and three brown-headed cowbird (Molothrus ater) nestlings. Deer...
Use of radioimmunoassay as a screen for antibiotics in confined animal feeding operations and confirmation by liquid chromatography/mass spectrometry
M. T. Meyer, J.E. Bumgarner, J.L. Varns, J.V. Daughtridge, E.M. Thurman, K.A. Hostetler
2000, Science of Total Environment (248) 181-187
Approximately one-half of the 50 000000 lb of antibiotics produced in the USA are used in agriculture. Because of the intensive use of antibiotics in the management of confined livestock operations, the potential exists for the transport of these compounds and their metabolites into our nation's water resources. A commercially...
Application of GPS and GIS to map channel features in Walnut Creek, Iowa
K. E. Schilling, C.F. Wolter
2000, Journal of the American Water Resources Association (36) 1423-1434
A 12-km reach of Walnut Creek was mapped at the Neal Smith National Wildlife Refuge in Jasper County, Iowa to identify and prioritize areas of the stream channel in need of further investigation or restoration. Channel features, including streambank conditions, bottom sediment materials and thickness, channel cross-sections, debris dams, tile...
Fatal toxoplasmosis in free-ranging endangered 'Alala from Hawaii
Thierry M. Work, J. Gregory Massey, Bruce A. Rideout, Chris H. Gardiner, David B. Ledig, O. C. H. Kwok, J. P. Dubey
2000, Journal of Wildlife Diseases (36) 205-212
The ‘Alala (Corvus hawaiiensis) is the most endangered corvid in the world, and intensive efforts are being made to reintroduce it to its former native range in Hawaii. We diagnosed Toxoplasma gondii infection in five free-ranging ‘Alala. One ‘Alala, recaptured from the wild because it was underweight and depressed, was...
Period doubling and other nonlinear phenomena in volcanic earthquakes and tremor
B.R. Julian
2000, Journal of Volcanology and Geothermal Research (101) 19-26
Evidence of subharmonic period-doubling cascades has recently been recognized in seismograms of volcanic tremor from several volcanoes. This phenomenon occurs only in nonlinear systems, and is the commonest route by which such systems change from periodic to chaotic behavior. It is predicted to occur in a model of volcanic tremor...
Transient calcite fracture fillings in a welded tuff, Snowshoe Mountain, Colorado
A.R. Hoch, M.M. Reddy, M.J. Heymans
2000, Applied Geochemistry (15) 1495-1504
The core from two boreholes (13.1 and 19.2 m depth) drilled 500 m apart in the fractured, welded tuff near the summit of the Snowshoe Mountain, Colorado (47??30'N, 106??55'W) had unique petrographic and hydrodynamic properties. Borehole SM-4 had highly variable annual water levels, in contrast to SM-1a, whose water level...
Characterization of active faulting beneath the Strait of Georgia, British Columbia
J.F. Cassidy, Gary C. Rogers, F. Waldhauser
2000, Bulletin of the Seismological Society of America (90) 1188-1199
Southwestern British Columbia and northwestern Washington State are subject to megathrust earthquakes, deep intraslab events, and earthquakes in the continental crust. Of the three types of earthquakes, the most poorly understood are the crustal events. Despite a high level of seismicity, there is no obvious correlation between the historical crustal...
Pesticides in the atmosphere of the Mississippi River Valley, part I: Rain
M.S. Majewski, W.T. Foreman, D. A. Goolsby
2000, Science of Total Environment (248) 201-212
Weekly composite rainfall samples were collected in three paired urban and agricultural regions of the Midwestern United States and along the Mississippi River during April–September 1995. The paired sampling sites were located in Mississippi, Iowa, and Minnesota. A background site, removed from dense urban and agriculture...
Alunite-jarosite crystallography, thermodynamics, and geochronology
R.E. Stoffregen, Charles N. Alpers, J.L. Jambor
2000, Reviews in Mineralogy and Geochemistry (40) 453-479
The alunite supergroup consists of more than 40 mineral species that have in common the general formula DG3(TO4)2(OH,H2O)6. The D sites are occupied by monovalent (e.g. K, Na, NH4, Ag, Tl, H3O), divalent (e.g. Ca, Sr, Ba, Pb), trivalent (e.g. Bi, REE) or more rarely quadrivalent (Th) ions; G is Al or Fe3+ or rarely Ga...
Turbidite megabeds in an Oceanic Rift Valley recording jokulhlaups of late Pleistocene glacial lakes of the western United States
G.G. Zuffa, W. R. Normark, F. Serra, C.A. Brunner
2000, Journal of Geology (108) 253-274
Escanaba Trough is the southernmost segment of the Gorda Ridge and is filled by sandy turbidites locally exceeding 500 m in thickness. New results from Ocean Drilling Program (ODP) Sites 1037 and 1038 that include accelerator mass spectrometry (AMS) 14C dates and revised petrographic evaluation of the sediment provenance, combined...
Channel stability downstream from a dam assessed using aerial photographs and stream-gage information
K. E. Juracek
2000, Journal of the American Water Resources Association (36) 633-645
The stability of the Neosho River channel downstream from John Redmond Dam, in southeast Kansas, was investigated using multiple-date aerial photographs and stream-gage information. Bankfull channel width was used as the primary indicator variable to assess pre- and post-dam channel change. Five six-mile river reaches and four stream gages were...
Identification of a basaltic component on the Martian surface from Thermal Emission Spectrometer data
P. R. Christensen, J. L. Bandfield, M. D. Smith, V.E. Hamilton, Roger N. Clark
2000, Journal of Geophysical Research: Planets (105) 9609-9621
The Mars Global Surveyor Thermal Emission Spectrometer (TES) instrument collected 4.8×106 spectra of Mars during the initial aerobraking and science‐phasing periods of the mission (September 14, 1997, through April 29, 1998). Two previously developed atmosphere‐removal models were applied to data from Cimmeria Terra (25°S, 213°W). The surface spectra derived for these...
Meter-Scale Characteristics of Martian Channels and Valleys
M. H. Carr, M. C. Malin
2000, Icarus (146) 366-386
Mars Global Surveyor images, with resolutions as high as 1.5 m pixel, enable characterization of martian channels and valleys at resolutions one to two orders of magnitude better than was previously possible. A major surprise is the near-absence of valleys a few hundred meters wide and narrower. The almost complete...
Responses of stable bay-margin and barrier-island systems to Holocene sea-level highstands, western Gulf of Mexico
Robert A. Morton, Jeffrey G. Paine, Michael D. Blum
2000, Journal of Sedimentary Research (70) 478-490
The microtidal, wave-dominated coast of the western Gulf of Mexico displays a variety of Holocene geomorphic features indicating higher-than-present water levels that were previously attributed to storm processes while geoidal sea level was at its present position. Field and aerial-photograph examinations of bay margins, barrier islands, and beach-ridge plains following...
Historical eruptions of Merapi Volcano, Central Java, Indonesia, 1768-1998
B. Voight, E.K. Constantine, S. Siswowidjoyo, R. Torley
2000, Journal of Volcanology and Geothermal Research (100) 69-138
Information on Merapi eruptive activity is scattered and much is remotely located. A concise and well-documented summary of this activity has been long needed to assist researchers and hazard-mitigation efforts, and the aim of this paper is to synthesize information from the mid-1700s to the present. A descriptive chronology is...
Relation of pathways and transit times of recharge water to nitrate concentrations using stable isotopes
M.K. Landon, G. N. Delin, S.C. Komor, C.P. Regan
2000, Ground Water (38) 381-395
Oxygen and hydrogen stable isotope values of precipitation, irrigation water, soil water, and ground water were used with soil-moisture contents and water levels to estimate transit times and pathways of recharge water in the unsaturated zone of a sand and gravel aquifer. Nitrate-nitrogen (nitrate) concentrations in ground water were also...
Lithofacies identification using multiple adaptive resonance theory neural networks and group decision expert system
H.-C. Chang, D. C. Kopaska-Merkel, H.-C. Chen, Durrans S. Rocky
2000, Computers & Geosciences (26) 591-601
Lithofacies identification supplies qualitative information about rocks. Lithofacies represent rock textures and are important components of hydrocarbon reservoir description. Traditional techniques of lithofacies identification from core data are costly and different geologists may provide different interpretations. In this paper, we present a low-cost intelligent system consisting of three adaptive resonance...
Numerical model of frazil ice and suspended sediment concentrations and formation of sediment laden ice in the Kara Sea
C. R. Sherwood
2000, Journal of Geophysical Research C: Oceans (105) 14061-14080
A one-dimensional (vertical) numerical model of currents, mixing, frazil ice concentration, and suspended sediment concentration has been developed and applied in the shallow southeastern Kara Sea. The objective of the calculations is to determine whether conditions suitable for turbid ice formation can occur during times of rapid cooling and wind-...
Corrosivities in a pilot-scale combustor of a British and two Illinois coals with varying chlorine contents
I.-M. Chou, J.M. Lytle, S.C. Kung, K.K. Ho
2000, Fuel Processing Technology (64) 167-176
Many US boiler manufacturers have recommended limits on the chlorine (Cl) content (< 0.25% or < 0.3%) of coals to be used in their boilers. These limits were based primarily on extrapolation of British coal data to predict the probable corrosion behavior of US coals. Even though Cl-related boiler corrosion...
A field technique for estimating aquifer parameters using flow log data
Frederick L. Paillet
2000, Ground Water (38) 510-521
A numerical model is used to predict flow along intervals between producing zones in open boreholes for comparison with measurements of borehole flow. The model gives flow under quasi-steady conditions as a function of the transmissivity and hydraulic head in an arbitrary number of zones communicating with each other along...
Change in field turbidity and trace element concentrations during well purging
J. Gibs, Zoltan Szabo, T. Ivahnenko, F.D. Wilde
2000, Ground Water (38) 577-588
Various physical and chemical properties were monitored sequentially in the field during well purging as indicators of stabilization of the composition of the water in the well. Turbidity was monitored on site during purging of oxic water from three wells with screened intervals open to an unconfined aquifer system in...