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Surface wind patterns at the Panama Canal vicinity are identified on the basis of 6 years of observed hourly surface wind data and with the use of high-resolution numerical model simulations. Statistical analysis of the observed wind at various stations in the Panama Canal is presented, together with the analysis of simulated surface wind fields that are obtained from the MM5 mesoscale meteorological model using surface wind assimilation and forced by North American regional reanalysis data. The performance analysis indicates that the 2-km-resolution MM5 model surface wind simulations have skill when compared with the observations at the measurement sites. The analysis of the wind fields for the period 2002–2007 shows that the dry season (January to April) is more spatially and temporally coherent than the wet season in the region. The simulated wind shows that the average wind speed reaches up to 7–8 m s−1 and the frequency of exceeding 5 m s−1 reaches up to 0.7–0.8 in Lake Gatun, the entrance/exit of the Canal in the Caribbean and Pacific coasts, and at high elevations. The dry season exhibits higher climatological wind speeds and exceedence frequencies than the wet season but the wet season shows greater spatial variability. For both seasons, the morning hours have lower average winds than the evening hours. The analysis underlines the significant influence of convection, sea breeze and local conditions (elevation gradients and land surface cover) in the observed and simulated surface wind patterns. The information presented herein, particularly as regards the Canal centerline results, may be useful for identifying the effects of air pollution from sources aboard transiting cargo ships on large communities in the Canal vicinity (e.g. Panama City). Information presented is also relevant to regional wind energy studies and fog formation analyses. Copyright © 2010 Royal Meteorological Society

A simplified boundary layer (SBL) model formulation is tested against the mesoscale meteorological model MM5 with respect to the 2 km interpolation of hourly surface wind station data for stations in the close vicinity of the Panama Canal. The required short computation time for the real time interpolation of the wind during air pollution incidents involving crossing cargo ships makes the use of simplified wind models an alternative to the full implementation of mesoscale models. The SBL model does take into consideration the land cover of the ground surface, which exhibits substantial variability in the study region. The SBL model produces features of wind speed that are similar to those of the MM5 simulation along the better-observed Canal centreline. The presence of orographic features makes the applicability of the simplified formulation reasonable only near the Canal where the terrain has small undulations. The simulated wind fields show that the dry season (January to April) is more spatially and temporally coherent than the wet season and that it also has higher wind speeds than the wet season. The evening hours have higher wind speeds than the morning hours in both seasons. The simulated wind exhibits higher average wind speeds and higher frequencies of exceeding 5 m s−1 within the Gatun Lake on the Caribbean side of the Isthmus and the entrance/exit of the Canal on the Caribbean and Pacific coasts. These results are useful for the development of effective disaster mitigation strategies for air pollution events in the region. Copyright © 2011 Royal Meteorological Society

Plant cells secrete a wide variety of defense-related proteins into the extracellular space or apoplast in response to pathogen attack. One of these, mannitol dehydrogenase (MTD), is normally a cytoplasmic enzyme whose primary role is the regulation of intracellular levels of the sugar alcohol mannitol in plants. Recent immunological and biochemical evidence, however, suggests that MTD is also secreted into the apoplast in response to pathogen attack, despite lacking a known peptide signal sequence for Golgi-mediated secretion. Because many plant pathogenic fungi secrete mannitol to overcome pathogen-induced generation of reactive oxygen species (ROS) by the plant, extracellular localization of MTD is hypothesized to have a defensive role of catabolizing pathogen-secreted mannitol. In the current study, LC/MSE was used to analyze proteins in the secretome of Apium graveolens (celery) following treatment with salicylic acid (SA), an endogenous elicitor of defense responses in plants. Levels of MTD in the secretome of SA-treated celery cell cultures were found to be induced at least 18-fold over secretome samples from cell cultures not exposed to SA. This value is in close agreement with published immunological and biochemical observations. Overall, this report provides the first mass spectrometry identification and quantification measurements supporting the hypothesis that MTD is secreted in response to simulated pathogen attack via a non-classical secretion mechanism. As demonstrated with MTD secretion, LC/MSE can be implemented as a discovery-driven MRM-based quantitative approach which can be used to reveal potential post-translational modifications, thus providing a new method in the area of gel-free and label-free proteomic analysis. Copyright © 2010 John Wiley & Sons, Ltd.