Publications by authors named "Joanna K York"

Article Synopsis
  • Heterosigma akashiwo has a specialized enzyme (NR2-2/2HbN) that can convert nitric oxide (NO) into usable nitrate for its growth.
  • Previous studies indicated that H. akashiwo's nitrate reductase activity is affected by different nitrogen sources, specifically being boosted by nitrate and inhibited by ammonium.
  • Recent findings suggest that H. akashiwo can efficiently assimilate NO for growth, especially when acclimated to ammonium environments, potentially giving it an advantage in nitrogen-scarce conditions.
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Suburban land use is expanding in many parts of the United States and there is a need to better understand the potential water-quality impacts of this change. This study characterized groundwater quality in a sandy, water-table aquifer influenced by suburban development and compared the results to known patterns in water chemistry associated with natural, background conditions and agricultural effects. Samples for nutrients, major ions, and isotopes of N and O in NO were collected in 2011 beneath turfgrass from 29 shallow wells (median depth 3.

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We developed, and applied in two sites, novel methods to measure ground water-borne nitrogen loads to receiving estuaries from plumes resulting from land disposal of waste water treatment plant (WWTP) effluent. In addition, we quantified nitrogen losses from WWTP effluent during transport through watersheds. WWTP load to receiving water was estimated as the difference between total measured ground water-transported nitrogen load and modeled load from major nitrogen sources other than the WWTP.

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