Richard M. Yager

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Public-supply wells with long screens in alluvial aquifers can produce waters of differing quality from different depths. Seasonal changes in quality are linked to seasonal changes in pumping rates that influence the distribution of flow into the well screens under pumping conditions and the magnitude and direction of intraborehole flow within the wells(More)
A recent article presented geochemical and microbial evidence establishing metabolic adaptation to and in-situ reductive dechlorination of trichloroethene (TCE) in a fractured dolomite aquifer. This study was designed to further explore site conditions and microbial populations and to explain previously reported enhancement of reductive dechlorination by(More)
Nonlinear regression is increasingly applied to the calibration of hydrologic models through the use of perturbation methods to compute the Jacobian or sensitivity matrix required by the Gauss-Newton optimization method. Sensitivities obtained by perturbation methods can be less accurate than those obtained by direct differentiation, however, and concern(More)
In 2007, the U.S. Geological Survey (USGS) completed a hydrogeologic study that included the development of a groundwater flow model of the glacial-drift aquifer in the Onondaga Lake (fig. 1). Glacial sediments within the Onondaga Trough contain freshwater, saline water, and brine, which has historically supported several chemical industries in Syracuse.(More)
Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this report is in the public domain, permission must be secured from the individual copyright owners to reproduce any copyrighted materials contained within this report. 14. Perspective three-dimensional views along(More)
The specific storage of a porous medium, a function of the compressibility of the aquifer material and the fluid within it, is essentially constant under normal hydrologic conditions. Gases dissolved in ground water can increase the effective specific storage of a confined aquifer, however, during water level declines. This causes a reduction in pore(More)
Normal N-acetylglucosamine 1-phosphotransferase activity toward mono- and oligosaccharide acceptor substrates was detected in cultured skin fibroblasts from mucolipidoses II and III patients who were designated as variants (one of four mucolipidosis II and three out of six mucolipidosis III patients examined). The activity toward natural lysosomal protein(More)
Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this report is in the public domain, permission must be secured from the individual copyright owners to reproduce any copyrighted materials contained within this report.; and generalized geologic(More)
An activator protein that stimulates the enzymic hydrolysis of sialic acid from gangliosides by ganglioside sialidase was fractionated from human liver. This fraction was distinct from those stimulating the hydrolysis of galactose from GM1 ganglioside by beta-galactosidase and the hydrolysis of N-acetylgalactosamine from GM2 ganglioside by hexosaminidase A.(More)
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