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Biliary polynuclear aromatic hydrocarbon (PAH) metabolites have been studied since the mid 1980s as an indicator of exposure of fish to PAHs. However, the measurements of PAH metabolites are often costly and time-consuming. A simple and rapid method, fixed-wavelength fluorescence (FF), was used to measure the concentrations of benzo(a)pyrene (B[a]P)-type...

The lake sturgeon (Acipenser fulvescens) has recently become a high priority for restoration management because of the near extinction of the species from many areas of North America. The identification of the level of population differentiation that naturally exists among lake sturgeon populations will be useful in the development of...

Most herbicides applied to crops are adsorbed by plants or transformed (degraded) in the soil, but small fractions are lost from fields and either move to streams in overland runoff, near surface flow, or subsurface drains, or they infiltrate slowly to ground water. Herbicide transformation products (TPs) can be more...

Sedimentary beds of jasper (red hematitic chert) in the Ordovician Løkken ophiolite of Norway are closely associated with volcanogenic massive sulphide (VMS) deposits. The jaspers occur in the immediate hangingwall and laterally peripheral to the large Løkken (25–30 Mt) and small Høydal (0.1 Mt) VMS deposits, and are exposed discontinuously for...

The mathematical modeling of ecosystems has contributed much to the understanding of the dynamics of such systems. Ecosystems can include not only the natural variety, but also artificial systems designed and controlled by humans. These can range from agricultural systems and activated sludge plants, down to mesocosms, microcosms, and aquaria,...

Activity of Swift Foxes (Vulpes velox) at den sites was studied in northwestern Texas during pup rearing seasons in 2000 and 2001 to determine role of males in parental care. Twenty-four percent of radio-collared females with a potential to breed successfully raised pups to eight weeks of age. We intensively...

The 315 m of Rosario Formation exposed at the San Antonio del Mar (SADM) section (Baja California, Mexico) contains moderately-to-well preserved benthic and planktic foraminifera, calcareous nannofossils, and molluscs. Nannofossils suggest most of the SADM section was deposited within a narrow interval of the late Campanian (CC21-CC22), whereas foraminifera and...

The influence of the Nyanza Chemical Waste Dump Superfund Site on the Sudbury River, Massachusetts, was assessed by analysis of sediment, fish prey organisms, and predator fish from four locations in the river system. Whitehall Reservoir is an impoundment upstream of the site, and Reservoir #2 is an impoundment downstream...

Northern Peru has an exceptionally rich archaeological heritage that includes metalwork, ceramics and textiles. The success of at least a half-dozen pre-Columbian societies dating back 3,000 years and subsequent Spanish colonization in the 1400s has rested on the effective use of northern Peru's abundant resources. In the summer of 2000,...

The Norman, Oklahoma, municipal landfill closed in 1985 after 63 years of operation, because it was identified as a point source of hazardous leachate composed of organic and inorganic compounds. The landfill is located on the floodplain of the Canadian River, a sand-bed river characterized by erodible channel boundaries and...

Nutrient fluxes were measured between Fourleague Bay, a shallow Louisiana estuary, and the Gulf of Mexico every 3 h between February 1 and April 30, 1994 to determine how high velocity winds associated with cold fronts and peak Atchafalaya River discharge influenced transport. Net water fluxes were ebb-dominated throughout the...

Many of today's agricultural landscapes once held vast amounts of wetland habitat for waterbirds and other wildlife. Successful restoration of these landscapes relies on access to accurate maps of the wetlands that remain. We used C-band (5.6-cm-wavelength), HH-polarized radar remote sensing (RADARSAT) at a 38?? incidence angle (8-m resolution) to...

Hydrophobic organic contaminants, although frequently detected in bed sediment and in aquatic biota, are rarely detected in whole-water samples, complicating determination of their occurrence, load, and source. A better approach for the investigation of hydrophobic organic contaminants is the direct analysis of sediment in suspension, but procedures for doing so...

No abstract available....

Abundance of invasive plants is often attributed to their ability ot outcompete native species. We compared resource acquisition and allocation of the invasive annual grass Bromus madritensis subsp. rubens with that of two native Mojave Desert annuals, Vulpia octoflora and Descurainia pinnata, in a glasshouse experiment. Each species was grown in monoculture at two densities and two...

We investigate the faulting process of the aftershock region of the 2000 western Tottori earthquake (Mw 6.6) by combining aftershock hypocenters and moment tensor solutions. Aftershock locations were precisely determined by the double difference method using P- and S-phase arrival data of the Japan Meteorological Agency unified catalog. By combining...

A thick lens of fresh groundwater exists in a large region of low permeability in the southern Lihue Basin, Kauai, Hawaii, USA. The conventional conceptual model for groundwater occurrence in Hawaii and other shield-volcano islands does not account for such a thick freshwater lens. In the conventional conceptual model, the...

The application of population and community ecology to solving real-world problems requires population and community dynamics models that reflect the myriad patterns of interaction among organisms and between the biotic and physical environments. Appropriate models are not hard to construct, but the experimental manipulations needed to evaluate their defining coefficients...

In ground water flow system models with hydraulic-head observations but without significant imposed or observed flows, extreme parameter correlation generally exists. As a result, hydraulic conductivity and recharge parameters cannot be uniquely estimated. In complicated problems, such correlation can go undetected even by experienced modelers. Extreme parameter correlation can be...

Use of stable isotope ratios to trace pathways of organic matter among consumers requires knowledge of the isotopic shift between diet and consumer. Variation in trophic shift among consumers can be substantial. For data from the published literature and supplementary original data (excluding fluid-feeding consumers), the mean isotopic shift for...

Ecologists use the term boundary to refer to a wide range of real and conceptual structures. Because imprecise terminology may impede the search for general patterns and theories about ecological boundaries, we present a classification of the attributes of ecological boundaries to aid in communication and theory development. Ecological boundaries...

Fractured calcareous nannofossils of the genus Discoaster from synimpact sediments within the Chesapeake Bay impact crater demonstrate that other petrographic shock indicators exist for the cratering process in addition to quartz minerals. Evidence for shock-induced taphonomy includes marginal fracturing of rosette-shaped Discoaster species into pentagonal shapes and pressure- and temperature-induced...

Comparative studies were performed on two native lamprey species, Pacific lamprey (Lampetra tridentata) and western brook lamprey (Lampetra richardsoni) from the Pacific coast along with sea lamprey (Petromyzon marinus) from the Great Lakes, to investigate their bile acid production and release. HPLC and ELISA analyses of the gall bladders and...

The T‐year annual maximum flood at a site is defined to be that streamflow, that has probability 1/T of being exceeded in any given year, and for a group of sites the corresponding regional flood probability (RFP) is the probability that at least one site will experience a T‐year flood in any given...

Information about the presence and recovery of coalbed gas during underground mining and attempts to recover the gas as an energy source, plus new data about gas storage capacity, petrography, maturity, and other coal quality factors, indicate that the coals of the Mecsek Basin may contain large quantities of coalbed...