Publications

Lipopolysaccharides (LPS) from Gram-negative bacteria are strong stimulators of white river crayfish, Procambarus zonangulus, haemocytes in vitro. Following haemocyte treatment with LPS and with LPS from rough mutant R5 (LPS Rc) from Salmonella minnesota, flow cytometric analysis revealed a conspicuous and reproducible decrease in cell size as compared to control haemocytes. These LPS...

Ecologists have long known that all ecosystems receive considerable quantities of materials from outside their boundaries (e.g., Elton 1927), and quantifying the magnitude of such fluxes has long been a central tenet of ecosystem ecology (e.g., Odum 1971). Thus, one might think that the consequences of such fluxes for food webs would be well understood. However, food webs have...

The negative impacts of biological invasion are economically and ecologically significant and, while incompletely quantified, they are clearly substantial. Ants (family Formicidae) are an important, although often overlooked, component of many terrestrial ecosystems. Six species of ants are especially striking in their global ability to invade, and their impacts. This paper focuses on...

During 2001, 76 water samples were collected upstream and downstream of select towns and cities in Iowa during high-, normal- and low-flow conditions to determine the contribution of urban centers to concentrations of pharmaceuticals and other organic wastewater contaminants (OWCs) in streams under varying flow conditions. The towns ranged in population from approximately 2000 to 200 000...

This report describes methods for calculating coefficients used to depict habitat productivity for grizzly bears in the Yellowstone ecosystem. Calculations based on these coefficients are used in the Yellowstone Grizzly Bear Cumulative Effects Model to map the distribution of habitat productivity and account for the impacts of human facilities. The coefficients of habitat productivity...

Plants may offer our best hope of removing greenhouse gases (gases that contribute to global warming) emitted to the atmosphere from the burning of fossil fuels. At the same time, global warming could change environments so that natural plant communities will either need to shift into cooler climate zones, or become extirpated (Prasad and Iverson, 1999; Crumpacker and others, 2001; Davis...

No abstract available.

No abstract available.

Water resources data for the 2003 water year for Alabama consist of records of stage, discharge, and water quality of streams; stages and contents of lakes and reservoirs; and water levels in wells. This report includes records on both surface and ground water in the State. Specifically, it contains: (1) discharge records for 130 streamflow-gaging stations, for 29 partial-record or...

In August and September of 1993 and January of 1994, the U.S. Geological Survey, under a cooperative agreement with the St. Johns River Water Management District (SJRWMD), conducted geophysical surveys of Kingsley Lake, Orange Lake, and Lowry Lake in northeast Florida. This report serves as an archive of unprocessed digital boomer seismic reflection data, trackline maps, navigation files...

Researchers studying invasive plants often concentrate their efforts on predictive models thought to allow invasive plants to dominate native landscapes. However, if an invasive is already well established then experimental research is necessary to provide the information necessary to effectively manage the species. Prescribing appropriate management strategies without prior experimental...

Bio- and photo-transformation of two munitions and explosives of concern, 2,6-dinitrotoluene (2,6-DNT) and 2,4,6-trinitrophenol (picric acid) were assessed in spiked marine sediments and water. A sandy and a fine-grained sediment, with 0.25% and 1.1% total organic carbon, respectively, were used for biotransformation assessments at 10 and 20 °C. Sterilized sediments were used as controls...