John M. Skelly

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Tropospheric ozone (O(3)) was first determined to be phytotoxic to grapes in southern California in the 1950s. Investigations followed that showed O(3) to be the cause of foliar symptoms on tobacco and eastern white pine. In the 1960s, "X" disease of ponderosa pines within the San Bernardino Mountains was likewise determined to be due to O(3). Nearly 50(More)
Canton Ticino in southern Switzerland is exposed to some of the highest concentrations of tropospheric ozone in Europe. During recent field surveys in Canton Ticino, foliar symptoms identical to those caused by ozone have been documented on native tree and shrub species. In Europe, the critical ozone level for forest trees has been defined at an AOT40 of 10(More)
The objectives of this study were to examine the foliar sensitivity to ozone exposure of 12 tree, shrub, and herbaceous species native to southern Switzerland and determine the seasonal cumulative ozone exposures required to induce visible foliar injury. The study was conducted from the beginning of May through the end of August during 2000 and 2001 using(More)
Tropospheric ozone has been identified as the most important regional scale air pollutant across much of eastern United States of America and many areas of Mediterranean climes in southern Europe (Millan et al. 1997). Within both regions, growing-season ozone exposures have been shown to induce distinctive foliar symptoms on numerous known sensitive plant(More)
The immunoprophylaxis of hepatitis B is hampered by the lack of a technique for growing hepatitis B virus (HBV) in tissue culture. Plasma from persistently infected individuals, one source of viral antigen, contains characteristic 22-nm spherical particles which share a common antigen (the hepatitis B surface antigen or HBsAg) with the outer envelope of the(More)
Ambient concentrations of tropospheric ozone and ozone-induced injury to black cherry (Prunus serotina) and common milkweed (Asclepias syriaca) were determined in north central Pennsylvania from 29 May to 5 September 2000 and from 28 May to 18 September 2001. Ogawa passive ozone samplers were utilized within openings at 15 forested sites of which six were(More)
Photochemical oxidants Cprimarily ozone) a s a i r p o l l u t a n t s pose a more serious problem t o f o r e s t s of t h e United S t a t e s than any o t h e r s i n g l e a i r p o l l u t a n t. Temperate and Mediterraean f o r e s t s elsewhere have most l i k e l y been s i m i l a r l y impacted and current i n v e s t i g a t i o n s of such e f f(More)
We are hosting the 34th Annual Air Pollution Workshop within our programs of The Environmental Resources Research Institute of The Pennsylvania State University with the meeting to be held April 16-18, 2002. Since the first meeting, as was held here at Penn State University in 1969, plant scientists with interest in air pollution effects to all forms of(More)
To identify the influences of sunflecks (lightflecks) and low light on plant responses to ozone exposures, studies were conducted in 1999 and 2000 within 12 Continuously Stirred Tank Reactor (CSTR) chambers. These CSTR chambers were housed within a greenhouse supplied with charcoal-filtered air situated at the Forest Resources Laboratory on the University(More)