Biomedical subjects
Publications and source records attributed to N M Johnson.
The present acidity and sulfur content of the upland streams of New England can be accounted for on the basis of the rainout and washout of sulfuric acid from the atmosphere. In spite of this excess acid flux over the New England landscape, the rate of cationic denudation of upland watersheds is relatively low.
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The nitrate concentration (weighted average) in stream water from an experimentally deforested watershed increased from 0.9 milligram per liter before removal of the vegetation to 53 milligrams per liter 2 years later. This nitrate mobilization, presumably due to increased microbial nitrification, was equivalent to all of the other net cationic increases and anionic decreases observed in tae drainage water.
Sarcoidosis is a multisystem disorder of unknown cause characterized by non-caseating granuloma formation and evidence of enhanced cellular immune response at the site of involvement. Although the majority of patients have a self-limiting illness, a significant proportion develop severe chronic disability.
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