An in vivo model fish system to test chemical effects on sexual differentiation and development: exposure to ethinyl estradiol
Diana M. Papoulias, Douglas B. Noltie, Donald E. Tillitt
2000, Aquatic Toxicology (48) 37-50
A model system was characterized which may be used as an in vivo screen for effects of chemicals or environmental mixtures on sexual differentiation and development of reproductive organs and gametes. We evaluated the effects of a model environmental estrogen, ethinyl estradiol (EE2), on the d-rR strain of medaka, Oryzias...
Physiological development and migratory behavior of subyearling fall chinook salmon in the Columbia River
K.F. Tiffan, D.W. Rondorf, P.G. Wagner
2000, North American Journal of Fisheries Management (20) 28-40
We describe the migratory behavior and physiological development of subyearling fall chinook salmon Oncorhynchus tshawytscha migrating through John Day Reservoir on the Columbia River, Washington and Oregon. Fish were freeze-branded and coded-wire-tagged at McNary Dam, Oregon, from 1991 to 1994, to determine travel time to John Day Dam and subsequent...
New site coefficients and site classification system used in recent building seismic code provisions
R. Dobry, R. D. Borcherdt, C.B. Crouse, I.M. Idriss, W. B. Joyner, G. R. Martin, M.S. Power, E.E. Rinne, R.B. Seed
2000, Earthquake Spectra (16) 41-67
Recent code provisions for buildings and other structures (1994 and 1997 NEHRP Provisions, 1997 UBC) have adopted new site amplification factors and a new procedure for site classification. Two amplitude-dependent site amplification factors are specified: Fa for short periods and Fv for longer periods. Previous codes included only a...
Reduction in recruitment of white bass in Lake Erie after invasion of white perch
Charles P. Madenjian, Roger L. Knight, Michael Bur, John L. Forney
2000, Transactions of the American Fisheries Society (129) 1340-1353
Recruitment to the adult population of white bass Morone chrysops in Lake Erie sharply declined during the early 1980s. To explain this phenomenon, we formulated the following four hypotheses: (1) the biological characteristics of adult spawners changed during the early 1980s, so that the ability to produce eggs decreased; (2) the decrease...
Shifts in depth distributions of alewives, rainbow smelt, and age-2 lake trout in southern Lake Ontario following establishment of Dreissenids
Robert O’Gorman, Joseph H. Elrod, Randall W. Owens, Clifford P. Schneider, Thomas H. Eckert, Brian F. Lantry
2000, Transactions of the American Fisheries Society (129) 1096-1106
In the mid-1990s, biologists conducting assessments of fish stocks in Lake Ontario reported finding alewives Alosa pseudoharengus, rainbow smelt Osmerus mordax, and juvenile lake trout Salvelinus namaycush at greater depths than in the mid-1980s. To determine if depth distributions shifted coincident with the early 1990s colonization of Lake Ontario by exotic Dreissena mussels, we calculated mean...
A test of a climatic index of dune mobility using measurements from the southwestern United States
N. Lancaster, P. Helm
2000, Earth Surface Processes and Landforms (25) 197-207
The climatic index of dune mobility developed by Lancaster (1988) has been applied to a variety of different environments. The index is, however, untested and unverified. We tested the index by comparison of values of the dune mobility index calculated from climate data with rates of sand transport measured at...
The vulnerability of wetlands to climate change: A hydrologic landscape perspective
Thomas C. Winter
2000, Journal of the American Water Resources Association (36) 305-311
The vulnerability of wetlands to changes in climate depends on their position within hydrologic landscapes. Hydrologic landscapes are defined by the flow characteristics of ground water and surface water and by the interaction of atmospheric water, surface water, and ground water for any given locality or region. Six general hydrologic...
Influences of dietary uptake and reactive sulfides on metal bioavailability from aquatic sediments
B.-G. Lee, Sarah B. Griscom, H.J. Choi, C.-H. Koh, James A. Luoma, Nicholas S. Fisher
2000, Science (287) 282-284
Understanding how animals are exposed to the large repository of metal pollutants in aquatic sediments is complicated and is important in regulatory decisions. Experiments with four types of invertebrates showed that feeding behavior and dietary uptake control bioaccumulation of cadmium, silver, nickel, and zinc. Metal concentrations in animal tissue correlated...
Modeling annual mallard production in the prairie-parkland region
M.W. Miller
2000, Journal of Wildlife Management (64) 561-575
Biologists have proposed several environmental factors that might influence production of mallards (Anas platyrhynchos) nesting in the prairie-parkland region of the United States and Canada. These factors include precipitation, cold spring temperatures, wetland abundance, and upland breeding habitat. I used long-term historical data sets of climate, wetland numbers, agricultural land...
Lipid concentrations in Lake Michigan fishes: Seasonal, spatial, ontogenetic, and long-term trends
Charles P. Madenjian, Robert F. Elliott, Timothy J. Desorcie, Ralph M. Stedman, Daniel V. O’Connor, Donald V. Rottiers
2000, Journal of Great Lakes Research (26) 427-444
Lipid concentrations were measured in seven species of fish from several locations in Lake Michigan during spring, summer, and fall in 1994 to 1995. Adult alewife (Alosa pseudoharengus) and age-2 coho salmon (Oncorhynchus kisutch) exhibited pronounced seasonal changes in lipid content. Adult alewives averaged 7.4% lipid, on a wet weight...
Use of field-applied quality control samples to monitor performance of a Goulden large-sample extractor/GC-MS method for pesticides in water
W.T. Foreman, Paul M. Gates, G.D. Foster, F. A. Rinella, S. W. McKenzie
2000, International Journal of Environmental Analytical Chemistry (77) 39-62
Since 1985, the Goulden large-sample extractor (GLSE) has been used to isolate a broad array of trace-organic contaminants from large volumes of water. In this study, field-applied quality control measures, including matrix and surrogate spikes and blanks, were used to monitor method performance from GLSE extraction through GC-MS analysis. The...
Bottom currents and sediment transport in Long Island Sound: A modeling study
R. P. Signell, J. H. List, A.S. Farris
2000, Journal of Coastal Research (16) 551-566
A high resolution (300-400 m grid spacing), process oriented modeling study was undertaken to elucidate the physical processes affecting the characteristics and distribution of sea-floor sedimentary environments in Long Island Sound. Simulations using idealized forcing and high-resolution bathymetry were performed using a three-dimensional circulation model ECOM (Blumberg and Mellor, 1987)...
Effects of nearshore recharge on groundwater interactions with a lake in mantled karst terrain
Terrie M. Lee
2000, Water Resources Research (36) 2167-2182
The recharge and discharge of groundwater were investigated for a lake basin in the mantled karst terrain of central Florida to determine the relative importance of transient groundwater inflow to the lake water budget. Variably saturated groundwater flow modeling simulated water table responses observed beneath two hillsides...
North-south geological differences between the residual polar caps on Mars
P.C. Thomas, M. C. Malin, K.S. Edgett, M. H. Carr, W.K. Hartmann, A.P. Ingersoll, P.B. James, L.A. Soderblom, J. Veverka, R. Sullivan
2000, Nature (404) 161-164
Polar processes can be sensitive indicators of global climate, and the geological features associated with polar ice caps can therefore indicate evolution of climate with time. The polar regions on Mars have distinctive morphologic and climatologic features: thick layered deposits, seasonal CO2 frost caps extending to mid latitudes, and near-polar...
A preliminary report on the 1999 Chi-Chi (Taiwan) earthquake
T. C. Shin, K.W. Kuo, W.H.K. Lee, T.L. Teng, Y.B. Tsai
2000, Seismological Research Letters (71) 24-30
No abstract available....
Physiological measures of neurotoxicity of diazinon and malathion to larval rainbow trout (Oncorhynchus mykiss) and their correlation with behavioral measures
S.L. Beauvais, S.B. Jones, S.K. Brewer, E. E. Little
2000, Environmental Toxicology and Chemistry (19) 1875-1880
Relations between neurotoxicants and changes in physiological parameters and behavior were investigated in larval rainbow trout (RBT; Oncorhynchus mykiss) exposed to sublethal concentrations of two organophosphate pesticides (OPs). Fish were exposed to diazinon and malathion in static-renewal experiments. After exposures for 24, 96, or 96 h, followed by 48 h...
Reactive transport of metal contaminants in alluvium: Model comparison and column simulation
J. G. Brown, R.L. Bassett, P. D. Glynn
2000, Applied Geochemistry (15) 35-49
A comparative assessment of two reactive-transport models, PHREEQC and HYDROGEOCHEM (HGC), was done to determine the suitability of each for simulating the movement of acidic contamination in alluvium. For simulations that accounted for aqueous complexation, precipitation and dissolution, the breakthrough and rinseout curves generated by each model were similar. The...
Characterization methods for fractured glacial tills
R.J. Haefner
2000, Ohio Journal of Science (100) 73-87
This paper provides a literature review of methods successfully employed to characterize finegrained and fractured or unfractured glacial deposits. Descriptions and examples are given for four major categories of characterization methods: physical, hydraulic, chemical, and indirect. Characterization methods have evolved significantly within the past ten years; however, there still exists...
Earthquake stress triggers, stress shadows, and seismic hazard
R.A. Harris
2000, Current Science (79) 1215-1225
Many aspects of earthquake mechanics remain an enigma at the beginning of the twenty-first century. One potential bright spot is the realization that simple calculations of stress changes may explain some earthquake interactions, just as previous and ongoing studies of stress changes have begun to explain human- induced seismicity. This...
Viscoelastic-coupling model for the earthquake cycle driven from below
J.C. Savage
2000, Journal of Geophysical Research B: Solid Earth (105) 25525-25532
In a linear system the earthquake cycle can be represented as the sum of a solution which reproduces the earthquake cycle itself (viscoelastic-coupling model) and a solution that provides the driving force. We consider two cases, one in which the earthquake cycle is driven by stresses transmitted along the schizosphere...
Pore fluid pressure, apparent friction, and Coulomb failure
N.M. Beeler, R.W. Simpson, S.H. Hickman, D.A. Lockner
2000, Journal of Geophysical Research B: Solid Earth (105) 25533-25542
Many recent studies of stress-triggered seismicity rely on a fault failure model with a single free parameter, the apparent coefficient of friction, presumed to be a material constant with possible values 0 ≤ μ′ ≤ 1. These studies may present a misleading view of fault strength and the role of...
New structural and stratigraphic insights for northwestern Pakistan from field and Landsat Thematic Mapper data
J. Robinson, R. Beck, E. Gnos, R.K. Vincent
2000, Geological Society of America Bulletin (112) 364-374
The remote Waziristan region of northwestern Pakistan includes outcrops of the India-Asia suture zone. The excellent exposure of the Waziristan ophiolite and associated sedimentary lithosomes and their inaccessibility made the use of Landsat Thematic Mapper (TM) data desirable in this study. Landsat TM data were used to create a spectral...
Partitioning sources of variation in vertebrate species richness
R.B. Boone, W.B. Krohn
2000, Journal of Biogeography (27) 457-470
Aim: To explore biogeographic patterns of terrestrial vertebrates in Maine, USA using techniques that would describe local and spatial correlations with the environment. Location: Maine, USA. Methods: We delineated the ranges within Maine (86,156 km2) of 275 species using literature and expert review. Ranges were combined into species richness maps,...
Root growth and function of three Mojave Desert grasses in response to elevated atmospheric CO2 concentration
C.K. Yoder, P. Vivin, L.A. DeFalco, J.R. Seemann, R.S. Nowak
2000, New Phytologist (145) 245-256
Root growth and physiological responses to elevated CO2 were investigated for three important Mojave Desert grasses: the C3 perennial Achnatherum hymenoides, the C4 perennial Pleuraphis rigida and the C3 annual Bromus madritensis ssp. rubens. Seeds of each species were grown at ambient (360 μl l−1) or elevated (1000 μl l−1)...
206Pb-230Th-234U-238U and 207Pb-235U geochronology of Quaternary opal, Yucca Mountain, Nevada
Leonid A. Neymark, Yuri V. Amelin, James B. Paces
2000, Geochimica et Cosmochimica Acta (64) 2913-2928
U–Th–Pb isotopic systems have been studied in submillimeter-thick outermost layers of Quaternary opal occurring in calcite–silica fracture and cavity coatings within Tertiary tuffs at Yucca Mountain, Nevada, USA. These coatings preserve a record of paleohydrologic conditions at this site, which is being evaluated as a potential high-level nuclear waste repository....
