Publications by authors named "Kathleen S Smith"

Article Synopsis
  • Dissolved copper (Cu) from acid mine drainage (AMD) is toxic to aquatic life, and its interaction with organic ligands like fulvic acids (FAs) affects its bioavailability.* -
  • The study analyzed FAs from pristine, AMD, and mixed waters in Colorado, finding that Cu was more toxic when associated with geochemically altered FAs, indicating how these interactions influence toxicity levels in aquatic systems.* -
  • Using spectral properties of FAs improved predictions of Cu toxicity in laboratory tests, but some measurement discrepancies remained, suggesting that the complexity of FAs in AMD may hold unknown factors impacting metal binding.*
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Objective: To understand perspectives of stakeholders during initial district-wide implementation of a Breakfast in the Classroom (BIC) model of the School Breakfast Program.

Design: Qualitative data were collected from twenty-nine focus groups and twenty interviews with stakeholders in a school district early in the process of implementing a BIC model of the School Breakfast Program.

Setting: Ten elementary schools within a large, urban school district in the USA that served predominantly low-income, racial/ethnic minority students.

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This study examines the effect on aquatic copper toxicity of the chemical fractionation of fulvic acid (FA) that results from its association with iron and aluminum oxyhydroxide precipitates. Fractionated and unfractionated FAs obtained from streamwater and suspended sediment were utilized in acute Cu toxicity tests on Ceriodaphnia dubia. Toxicity test results with equal FA concentrations (6 mg FA/L) show that the fractionated dissolved FA was 3 times less effective at reducing Cu toxicity (EC50 13 ± 0.

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This study evaluates the potential use of stable zinc isotopes in toxicity studies measuring zinc uptake by the gills of brown trout (Salmo trutta) and rainbow trout (Oncorhynchus mykiss). The use of stable isotopes in such studies has several advantages over the use of radioisotopes, including cost, ease of handling, elimination of permit requirements, and waste disposal. A pilot study using brown trout was performed to evaluate sample preparation methods and the ability of a quadrupole inductively coupled plasma mass spectrometer (ICP-MS) system to successfully measure changes in the (67)Zn/(66)Zn ratios for planned exposure levels and duration.

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The objective of the present study was to employ an enriched stable-isotope approach to characterize Zn uptake in the gills of rainbow trout (Oncorhynchus mykiss) during acute Zn exposures in hard water (approximately 140 mg/L as CaCO3) and soft water (approximately 30 mg/L as CaCO3). Juvenile rainbow trout were acclimated to the test hardnesses and then exposed for up to 72 h in static exposures to a range of Zn concentrations in hard water (0-1000 microg/L) and soft water (0-250 microg/L). To facilitate detection of new gill Zn from endogenous gill Zn, the exposure media was significantly enriched with 67Zn stable isotope (89.

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Concentrations of 31 metals, metalloids, and other elements were measured in insects and insectivorous bird tissues from three drainages with different geochemistry and mining histories in Summit Co., Colorado, in 2003, 2004, and 2005. In insect samples, all 25 elements that were analyzed in all years increased in both Snake and Deer Creeks in the mining impacted areas compared to areas above and below the mining impacted areas.

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