Conference Papers

Embryos (stage 8-47, Nieuwkoop and Faber) of the African clawed frog (Xenopus laevis) were subjected to water-borne depleted uranium (DU) concentrations that ranged from 4.8 to 77.7 mg/Lusing an acute 96-h frog embryo teratogenesis assay-Xenopus (FETAX). In a chronic 64-d assay, X. laevis (from embryo through metamorphosis; stages 8-66) were subjected to concentrations of DU that ranged...

We conducted two studies of Se exposure in captive common eiders (Somateria mollissima). In Study 1, eiders were fed diets with added Se (as L-selenomethionine) in concentrations increasing from 10 ppm to 80 ppm. In Study 2, eiders received control, low exposure (20 ppm Se), and high exposure (60 ppm Se) diets. One duck in the high exposure group in Study 2 died after 36 days. Remaining...

A wetland sediment-derived microbial consortium was developed by the USGS and propagated in vitro to large quantities by SiREM Laboratory for use in bioaugmentation applications. The consortium had the capacity to completely dechlorinate 1,1,2,2-tetrachloroethene, tetrachloroethylene, trichloroethylene, 1,1,2-trichloroethane, cis- and trans-1,2-dichoroethylene, 1.1-dichloroethylene, 1,2

Three multi-parameter water-quality monitors equipped with either Clark cell type or optical type dissolved-oxygen sensors were deployed for 30 days in a brackish (salinity

The RiverSonde radar makes non-contact measurement of a horizontal swath of surface velocity across a river section. This radar, which has worked successfully at several rivers in the Western USA, has shown encouraging correlation with simultaneous measurements of average currents at one level recorded by an acoustic travel-time system. This work reports a field study intercomparing data...

Boreal ecosystems contain a substantial fraction of the earth's soil carbon stores and are prone to frequent and severe wildfires. In this study, we examine changes in element and organic matter stocks due to a 1999 wildfire in Alaska. One year after the wildfire, burned soils contained between 1071 and 1420 g/m2 less carbon than unburned soils. Burned soils had lower nitrogen than...

In a laboratory experiment we investigated micro- and nanoscale changes in fossil diatom valves and in the texture of diatomaceous sediments that result from ice sheet overburden and subglacial shearing. Our experiment included compression and shearing of Antarctic diatom-rich sediments in a ring shear device and comparison of experimental samples with natural glacial sediments from the...

The U.S. Geological Survey (USGS) and Alaska Department of Natural Resources (ADNR) are continuing investigations on element mobility in mineralized and non-mineralized areas of the Yukon-Tanana Upland in east-central Alaska. The chemistry of stream water is evaluated in the context of regional bedrock geology and geologic structure. Sampling sites were located in the Big Delta B2...

In Australia and America, encroachment by conflicting land uses, zoning restrictions, and the "not in my backyard" syndrome make it increasingly difficult to access high-quality aggregate resources located near the market areas. Attempts by government agencies in America to protect aggregate resources for future development have met with varying degrees of success. The State of...

The electrical properties of the ground directly beneath a ground penetrating radar (GPR) antenna very close to the earth's surface (ground-coupled) must be known in order to predict the antenna response. In order to investigate changing antenna response with varying ground properties, a series of finite difference time domain (FDTD) simulations were made for a bi-static (fixed...

This communication summarizes viewpoints, discussion, perspectives, and questions, put forward at a workshop on "Growth hormone and insulin-like growth factors in fish" held on September 7th, 2004, at the 5th International Symposium on Fish Endocrinology in Castello??n, Spain. ?? 2005 Elsevier Inc. All rights reserved.

During the last 30 years, the methodology for assessment of undiscovered conventional oil and gas resources used by the Geological Survey has undergone considerable change. This evolution has been based on five major principles. First, the U.S. Geological Survey has responsibility for a wide range of U.S. and world assessments and requires a robust methodology suitable for immaturely...