Historically, Vibrio parahaemolyticus infections have been characterized by sporadic cases caused by multiple, diverse serotypes. However, since 1996, V. parahaemolyticus serotype O3:K6 strains have been associated with several large-scale outbreaks of illness, suggesting the emergence of a "new" group of organisms with enhanced virulence. We have applied three different molecular subtyping tec...

[1] The Pb-Be-O3 relationships observed in three aircraft missions over the western Pacific (PEM-West A and B, TRACE-P) are simulated with a global three-dimensional chemical tracer model (GEOS-CHEM) driven by assimilated meteorological observations. Results are interpreted in terms of the constraints that they offer on sources of tropospheric ozone (O3). Aircraft observations of fresh Asian ou...

[1] Changes in emissions of ozone (O3) precursors affect both air quality and climate. We first examine the sensitivity of surface O3 concentrations (O3 ) and net radiative forcing of climate (RFnet) to reductions in emissions of four precursors – nitrogen oxides (NOx), non-methane volatile organic compounds, carbon monoxide, and methane (CH4). We show that long-term CH4-induced changes in O3, ...

[1] Extensive chemical characterization of ozone (O3) depletion events in the Arctic boundary layer during the TOPSE aircraft mission in March–May 2000 enables analysis of the coupled chemical evolution of bromine (BrOx), chlorine (ClOx), hydrogen oxide (HOx) and nitrogen oxide (NOx) radicals during these events. We project the TOPSE observations onto an O3 chemical coordinate to construct a ch...

Exposure to ambient ozone (O3) is associated with increased exacerbations of asthma. We sought to determine whether mast cell degranulation is induced by in vivo exposure to O3 in mice and whether mast cells play an essential role in the development of pulmonary pathophysiological alterations induced by O3. For this we exposed mast cell-deficient WBB6F1-kitW/kitW-v (kitW/kitW-v) mice and the co...

Eleven mild atopic asthmatic patients were exposed for 6 h, in randomized order, to air, 100 ppb O3, 200 ppb NO2, and 100 ppb O3 + 200 ppb NO2, followed immediately by bronchial allergen challenge. Subsequently 10 of these patients were exposed for 3 h to air, 200 ppb O3, 400 ppb NO2, and 200 ppb O3 + 400 ppb NO2, followed immediately by bronchial allergen challenge. All exposures were carried ...

In this study, the Community Multiscale Air Quality (CMAQ) modeling system is used to simulate the ozone (O3) episodes during the Program of Regional Integrated Experiments of Air Quality over the Pearl River Delta, China, in October 2004 (PRIDE-PRD2004). The simulation suggests that O3 pollution is a regional phenomenon in the Pearl River Delta (PRD). Elevated O3 levels often occurred in the s...

We examine the distribution of tropical tropospheric ozone (O3) from the Microwave Limb Sounder (MLS) and the Tropospheric Emission Spectrometer (TES) by using a global three-dimensional model of tropospheric chemistry (GEOS-Chem). MLS and TES observations of tropospheric O3 during 2005 to 2009 reveal a distinct, persistent O3 maximum, both in mixing ratio and tropospheric column, in May over t...

Tolerance to respiratory effects of O3 has been demonstrated for anatomic and functional changes, but information about tolerance to O3-induced airway hyperresponsiveness (AHR) is scarce. In guinea pigs exposed to air or O3 (0.3 parts/million, 4 h/day, for 1, 3, 6, 12, 24, or 48 days, studied 16-18 h later), pulmonary insufflation pressure changes induced by intravenous substance P (SP, 0.032-3...

A review of the literature reveals that ozone (O3) exposure can either suppress or enhance immune responsiveness. These disparate effects elicited by O3 exposure depend, in large part, on the experimental design used, the immune parameters examined as well as the animal species studied. Despite the apparent contradictions, a general pattern of response to O3 exposure can be recognized. Most stu...