Search

Daily exposure to PM2.5 in developing countries has not been thoroughly studied partly due to limited resources available. In this research, personal PM2.5 exposures in urban communities in Indonesia were examined using a low-cost sensor, AS-LUNG. Fifty subjects were recruited in both wet and dry seasons. Their personal PM2.5 concentrations, environmental temperature, and relative humidity were measured using corrected AS-LUNG Portable worn or placed in their vicinity. Details on their activities and locations, air quality (air pollution sources), and weather conditions during monitoring were recorded in time-activity diaries completed at 30 min intervals. Results revealed mosquito coil burning as the source of highest exposure, reaching 241.5 μg/m3 but with significant difference between wet and dry seasons. With ambient PM2.5 and relative humidity controlled for, mosquito coil burning contributed 12.02 μg/m3 and 4.84 μg/m3 of personal PM2.5 exposure in wet and dry season, respectively, which was several times higher than the contribution from vehicle emission. The second most contributive source was factory smoke, which increased 4.99 μg/m3 and 3.17 μg/m3 of exposure in wet and dry season, respectively. Findings on contributive factors of high daily personal exposures can serve as useful references for formulating policies and recommendations on exposure reduction and health protection.

With emission control efforts, the PM2.5 concentrations and PM2.5 exceedance days (daily mean PM2.5 concentrations >35 µg m−3) show an apparent declining trend from 2006–2017. The PM2.5 concentrations increase from the northern to southern part of western Taiwan, and reductions in the PM2.5 concentration generally decrease from northern to southern part of western Taiwan. Thus, mitigation of the PM2.5 problem is less effective in southwestern Taiwan than in other regions in Taiwan. Analysis of a 39-year ERA-interim reanalysis dataset (1979–2017) reveals a weakening of the East Asian winter monsoon, a reduction in northeasterly (NE) monsoonal flow, and a tendency of enhanced stably stratified atmospheric structures in Taiwan and the surrounding area. The observed surface wind speed also presents a long-term decline. We can conclude that the long-term PM2.5 variations in Taiwan are mainly associated with changes in local anthropogenic emissions and modulated by short-term yearly variations due to strong haze events in China. In southwestern Taiwan, the long-term trend of PM2.5 reductions is possibly offset by worsening weather conditions, as this region is situated on the leeside of the mountains and often subject to stagnant wind when under the influence of NE monsoonal flow.

Due to the urban heat island effect becoming more evident in the cities in Taiwan, the urban climate has become an essential factor in urban development. Taiwan is located on the border of tropical and subtropical climate zones, the climate condition is hot and humid, and the city shows high-density development. The dense urban development has increased the heat storage capacity of the ground and buildings. However, if only the climate stations set by the Central Meteorological Bureau to observe the climate data are applied, the predicted results differ from the actual urban climate conditions due to the small number of these stations and the too far distance between them. Therefore, this study employs the local climate zone (LCZ), which can classify the land features by considering both land use and land cover, and can be freely generated from satellite images. The LCZ classification method can view the type of the city through the height and density of obstacles. This study also combines the urban canopy model (UCM) of the mesoscale climate prediction model and weather research and forecasts (WRF). This approach can calculate vertical and horizontal planes of the city, such as building volume, road width, the influence of streets and roofs, roof heat capacity, building wall heat capacity, etc., to predict the climatic conditions in different lands in the study area. Simultaneously, to understand the actual distribution of urban climate more accurately, this study used the microclimate measurement network built in the research area to produce pedestrian-level temperature distribution and compared the estimated results with the actual measured values for urban climate assessment. This study can understand the cause of urban heat islands and assist urban planners more appropriately formulate heat island mitigation strategies in different regions.

The climate in Taiwan is hot and humid, and urban show high-density development. The dense urban development has increased the heat storage of the ground and buildings. The compact arrangement of tall buildings causes the narrowness of the urban space to block the sky's view and hinders the relatively smooth airflow, which will cause problems such as poor ventilation in the city and cause high thermal risk in the city. In the past, when obtaining climate data, if only the climate stations set by the Central Meteorological Bureau were used, the distance between the stations was too far, and the coverage of the ground around the distribution area was almost the same, resulting in significant differences between the predicted results and the actual climate conditions. Therefore, this research established a microclimate measurement network to obtain climate data. For the urban environment information, the urban built environment data, such as digital surface model, and building information, were regulated data or required to purchase. Therefore, this study uses the Local Climate Zone (LCZ) which can consider land use and land cover simultaneously and can be freely produced by satellite images. The typology classification method can be used to view the city by the height and density of obstacles. LCZ can solve the inaccuracy of estimation caused by the mixed land-use in Taiwan and assign various types of related data from the scheme such as heat capacity, albedo, and roughness through classification results. This study herein applies LCZ combined with a mesoscale climate prediction model Weather Research and Forecasting (WRF) to predict the climate conditions within the study's scope and compare them with actual measured values. It can be used for urban climate assessment. The research results preliminarily show that by applying the LCZ classification and its corresponding factors to WRF with Multi-layer urban canopy model which can consider vertical surfaces such as building volume facades horizontal surfaces such as streets and roofs. The predicted temperature and actual temperature will be slightly underestimated, and it can be approximately between 1.5°C to 2.5°C in the urban area at night and 0.5°C to 1°C during the day. This phenomenon may be due to the relative ratio of buildings and road width in Taiwan, making the actual night. The heat dissipation effect is poor, and it is easy to cause heat accumulation in the urban area.

In this study, cluster analysis is applied to the daily averaged wind fields and sea-level pressure observed at surface weather stations in Taiwan from January 2013 to March 2018 to classify the synoptic weather patterns and study the characteristics of corresponding air pollutants, including fine particulate matter (PM2.5), coarse particulate matter (PM10), and ozone (O3). The classification identified six weather types: Clusters 1, 2, and 3 (C1–C3), which are typical winter weather types and associated with high air pollutant concentrations—C3, in particular, influenced by weak synoptic weather, is associated with the lowest wind speeds and the highest PM2.5 and PM10 concentrations and represents the most prevalent weather type that is prone to the occurrence of PM2.5 events; C4, which occurs mostly during seasonal transition months and is associated with the highest O3 concentrations; and C5 and C6, which are summer weather types with low air pollutant concentrations. Further analysis of the local wind flow using the 0.3° ERA5 reanalysis dataset and surface-observed wind data indicates that in western Taiwan, the land-sea breeze is embedded within the synoptic weather type of C3, which is favorable to air pollutant accumulation. However, when the prevailing northeasterly wind is obstructed by the Central Mountain Range, southwestern Taiwan, being situated on the leeside of the mountains, often exhibits the worst air pollution due to stagnant wind conditions.

Daily exposure to PM

The Weather Research and Forecasting (WRF) modeling system obtains the aerodynamic roughness length (z0) from a land use (LU) lookup table. The effective aerodynamic roughness length (z0eff) was estimated for the island of Taiwan by considering the individual roughness lengths (z0i) of the underlying LU types within a modeling grid box. Two z0eff datasets were prepared: one using the z0i from the default LU lookup table and the other using the observed z0i for three LU types (urban, dry cropland and pasture, and irrigated cropland and pasture). The spatial variability of the z0eff distribution was higher than that of the LU table-based z0 distribution. Three WRF sensitivity experiments were performed: (1) dominant LU table-based z0 (namely, S1), (2) z0eff estimated from the default z0i (namely, S2), and (3) z0eff estimated from the observed z0i (namely, S3). Comparisons of the thermal field, temperature, and surface sensible and latent heat fluxes revealed no significant differences among the three simulations. The wind field overestimation and surface momentum flux underestimation in S1 were reduced in S2 and S3, and these improvements were more prominent over areas with highly heterogeneous land surface conditions.

Yunlin County is located in the central part of western Taiwan with major emissions from the Mailiao industrial park, the Taichung Power Plants and heavy traffic. In order to understand the influence of meteorological conditions on PM 2.5 concentrations in Yunlin County, we applied a two-stage cluster analysis method using the daily averaged surface winds from four air quality monitoring stations in Yunlin County to classify the weather pattern. The study period includes 1095 days from Jan 2013 to December 2015. The classification results show that the low PM 2.5 concentration occurs when the synoptic weather in Taiwan is affected by the strong southwesterly monsoonal flow. The high PM 2.5 concentration occurs when Taiwan is under the influence of weak synoptic weather conditions and continental high-pressure peripheral circulation. A high PM 2.5 event was studied and the Weather Research and Forecasting (WRF) meteorological model was performed. The result indicated that due to being blocked by the Central Mountain Range, Yunlin County, which is situated on the leeside of the mountains, exhibits low wind speed and strong subsidence behavior that favors PM 2.5 accumulation.

This study investigates the effect of soil moisture initializations and soil texture on the land surface hydrologic processes and its feedback on atmospheric fields in Taiwan. The simulations using the Weather Research and Forecasting (WRF) Model with the Noah land surface model were conducted for a 1-month period from 10 August to 12 September 2013 that included two typhoon-induced precipitation episodes and a series of clear-sky days. Soil moisture from the Global Land Data Assimilation System (GLDAS) was utilized to provide the soil moisture initialization process. In addition, updated soil textures based on field surveys in Taiwan were adopted for the WRF Model. Three WRF sensitivity runs were performed. The first simulation is the base case without any update (WRF-base), the second simulation utilizes GLDAS products to initialize the soil moisture (WRF-GLDAS), and the third simulation includes GLDAS products plus the updated soil textures and soil parameters (WRF-GSOIL). In WRF-base, the soil moisture initialization process is provided from National Centers for Environmental Prediction (NCEP) Final (FNL) Operational Global Analysis data, which are higher than the data from GLDAS products. The WRF-GLDAS and WRF-GSOIL with use of GLDAS data show lower soil moisture than WRF-base and agree better with observed data, while WRF-base shows a systematic wet bias of soil moisture throughout the simulation periods. In WRF-GSOIL, the soil textures with large-sized soil particles reveal higher soil conductivity; as a result, water drains through the soil column in a faster manner than the WRF-GLDAS, which leads to reduced soil moisture in western Taiwan. Among the three simulations, the variation of soil moisture is best simulated in WRF-GSOIL.

A real-time air quality forecasting (AQF) system was developed in Taiwan using the Weather Research and Forecasting meteorological model and Community Multiscale Air Quality model framework. This study evaluated the performance of the one-year archived AQF PM2.5 forecasts (October 2018 to September 2019) and developed a bias-correction method to improve the accuracy of the PM2.5 forecasts. The bias-correction method incorporates a cluster-analysis-based synoptic weather pattern (WP) classification (one type of analog method). In principle, the historical model errors are categorized according to the synoptic WP and used to adjust the PM2.5 forecast. First, the synoptic WPs are determined using K-means cluster analysis (six WPs were identified). Second, the historical AQF PM2.5 bias at each surface station is estimated for each classified WP. Third, a linear-regression relationship between the AQF PM2.5 bias and PM2.5 forecasts for the six WPs is developed to postprocess the PM2.5 forecasts. The AQF PM2.5 bias is found to have a strong dependency on the synoptic WP. A performance assessment of the AQF PM2.5 forecasts reveals systematic PM2.5 underprediction, with the most pronounced underprediction occurring on days associated with weak synoptic weather conditions. Under these conditions, a severe PM2.5 event is likely to occur in Taiwan. The bias-correction method is able to reduce the PM2.5 forecast error and improve the root mean square error (RMSE) and mean bias (MB) calculations. The improvement is most significant on days associated with a weak synoptic WP and in regions where high PM2.5 concentrations are likely to occur. The method is shown to be effective at reducing the AQF PM2.5 bias.

The objective of this study is to understand the influence of regional climate change on local meteorological conditions and their subsequent effect on local ozone (O3) dispersion in Taiwan. The 33-year NCEP-DOE Reanalysis 2 (NNR2) data set (1979–2011) was analyzed to understand the variations in regional-scale atmospheric conditions in East Asia and the western North Pacific. To save computational processing time, two scenarios representative of past (1979–86) and current (2004–11) atmospheric conditions were selected but only targeting the autumn season (September, October and November) when the O3 concentrations were at high levels. Numerical simulations were performed using weather research and forecasting (WRF) model and Community Multiscale Air Quality (CMAQ) model for the past and current scenarios individually but only for the month of October because of limited computational resources. Analysis of NNR2 data exhibited increased air temperature, weakened Asian continental anticyclone, enhanced northeasterly monsoonal flow, and a deepened low-pressure system forming near Taiwan. With enhanced evaporation from oceans along with a deepened low-pressure system, precipitation amounts increased in Taiwan in the current scenario. As demonstrated in the WRF simulation, the land surface physical process responded to the enhanced precipitation resulting in damper soil conditions, and reduced ground temperatures that in turn restricted the development of boundary layer height. The weakened land–sea breeze flow was simulated in the current scenario. With reduced dispersion capability, air pollutants would tend to accumulate near the emission source leading to a degradation of air quality in this region. The conditions would be even worse in southwestern Taiwan due to the fact that stagnant wind fields would occur more frequently in the current scenario. On the other hand, in northern Taiwan, the simulated O3 concentrations are lower during the day in the current scenario due to the enhanced cloud conditions and reduced solar radiation.

Leukoreduction in blood units could prevent patients undergoing transfusions from transfusion-associated adverse reactions (TAARs) such as febrile nonhemolytic transfusion reactions (FNHTRs). However, the effect of prestorage and poststorage leukoreduction on TAARs and its underlying mechanisms in stored blood components remains to be determined. Therefore, we investigated the impact of prestorage leukocyte-reduced (pre-LR) and poststorage leukocyte-reduced (post-LR) blood products, including red blood cells (RBCs) and apheresis platelets (PHs), on the incidence of FNHTRs and other TAARs in patients who received transfusions from 2009 to 2014 in a tertiary care center. We also investigated the difference of leukocyte-related bioactive mediators between pre- and post-LR blood components. The results indicated that prevalence of TAARs was significantly reduced in the transfusions of pre-LR blood components. Particularly, the prevalence of FNHTRs was significantly reduced in the pre-LR RBC transfusions and the prevalence of allergy reactions was markedly reduced in the pre-LR PH transfusions. Furthermore, in vitro evaluation of cytokines in the pre- and post-LR blood components revealed that IL-1β, IL-8 and RANTES levels were significantly elevated in the post-LR RBCs during the storage. In contrast, IL-1β, IL-6 and IL-8 levels were significantly elevated in the post-LR PHs during the storage. These findings suggested that prestorage leukoreduction had a diminishing effect on the development of TAARs, which could be associated with less accumulation of cytokines in the stored blood components.

Ammonia (NH3) is an important precursor of inorganic fine particulate matter (PM2.5). Without specific information on the temporal variation in NH3 emissions, a simplified temporal variation in NH3 emissions is often used in chemical transport models. To better characterize NH3 emissions in an air quality model simulation for Taiwan, a dynamical NH3 emissions parameterization was applied to improve the temporal profile of NH3 emissions from livestock operations, synthetic nitrogen fertilizers, and standing crops. The Community Multiscale Air Quality (CMAQ) modeling simulation with a fixed NH3 emissions rate (the CONST experiment) presents a large positive bias in simulated nitrate and NH3, particularly during the nighttime and winter months. On the other hand, the CMAQ simulation with a dynamical NH3 emissions approach (the DYN experiment) improves the diurnal and seasonal variations and reduces the simulated bias. Moreover, according to the Taiwan emissions inventory, NH3 emissions from sewage accounts for a large portion (37%) of total NH3 emissions in Taiwan. The CMAQ simulation with the dynamical NH3 emissions approach and with a reduced level of NH3 emissions from sewage (the DYN1 experiment) was conducted to assess the possibility that the existing Taiwan emissions inventory may overestimate sewage NH3 emissions. The evaluations with observed NH3, nitrate, and ammonium wet deposition concentrations indicate that the DYN1 experiment performs better than the CONST and DYN experiments.

This study is conducted to identify the synoptic weather patterns that are prone to cause high carbon monoxide (CO) concentrations observed at a mountain site, Lulin atmospheric background station (LABS), in Taiwan due to the biomass-burning activity in Southeast (SE) Asia. LABS is recognized as a clean background station. The study period targets the biomass-burning season (February to May) from 2007 to 2010. The synoptic weather patterns were classified using a two-stage clustering method with inputs from the Weather Research and Forecasting (WRF) meteorological model simulation result in a 27-km spatial grid. A 9-km resolution WRF modeling was performed additionally for 13 to 26 March 2007, when a high CO concentration reaching 500 ppb was observed at LABS. The simulation result indicates that not only the existence of the thermal forcing induced low pressure system formed in Indochina, but also the presence of the high terrain located in the northern part of SE Asia that further forced the uplift of the biomass-burning emissions. On the other hand, when the northeasterly monsoonal flow is strong enough and intruding into Indochina, this would hinder the development of the thermal low and weaken the upward movements, in turn preventing the transport of biomass-burning emissions from Indochina to the area of Taiwan. The simulation results also demonstrate that the location of the SE Asia high pressure system has a moderate effect on the particle dispersion path in the upper level.

The U.S. Geological Survey (USGS) land use (LU) data employed in the Weather Research and Forecasting (WRF) model classify most LU types in Taiwan as mixtures of irrigated cropland and forest, which is not an accurate representation of current conditions. The WRF model released after version 3.1 provides an alternative LU dataset retrieved from 2001 Moderate Resolution Imaging Spectroradiometer (MODIS) satellite products. The MODIS data correctly identify most LU-type distributions, except that they represent western Taiwan as being extremely urbanized. A new LU dataset, obtained using 2007 Système Probatoire d’Observation de la Terre (SPOT) satellite imagery [from the National Central University of Taiwan (NCU)], accurately shows the major metropolitan cities as well as other land types. Three WRF simulations were performed, each with a different LU dataset. Owing to the overestimation of urban area in the MODIS data, WRF-MODIS overpredicts daytime temperatures in western Taiwan. Conversely, WRF-USGS underpredicts daytime temperatures. The temperature variation estimated by WRF-NCU falls between those estimated by the other two simulations. Over the ocean, WRF-MODIS predicts the strongest onshore sea breezes, owing to the enhanced temperature gradient between land and sea, while WRF-USGS predicts the weakest onshore flow. The intensity of the onshore breeze predicted by WRF-NCU is between those predicted by WRF-MODIS and WRF-USGS. Over Taiwan, roughness length is the key parameter influencing wind speed. WRF-USGS significantly overpredicts the surface wind speed owing to the shorter roughness length of its elements, while the surface wind speeds estimated by WRF-NCU and WRF-MODIS are in better agreement with the observed data.

Adequate air quality modeling is reliant on accurate meteorological simulations especially in the planetary boundary layer (PBL). To understand how the boundary layer processes affect the mixing and transport of air pollutants, the sensitivity of Weather Research Forecasting (WRF) model with different PBL schemes (YSU and MYJ) is utilized. Community Multiscale Air Quality (CMAQ) modeling system is performed subsequently to study the effects of the PBL physical processes on the meteorological and air quality simulations. A comparison is made of two distinct atmospheric conditions. Case 1 considers the influence of the Asian continental outflow where air pollutants carried by long-range transport (LRT) to Taiwan. The variation in ozone (O3) concentration between the two sensitivity runs is mainly caused by the PBL height difference with WRF–MYJ predicts much deeper PBL height near the frontal low-pressure region than does the WRF–YSU. Case 2 is associated with the land-sea breeze flow. In this situation O3 is locally produced from the western side of the country where major metropolitan cities and highways are located. Distinctions in O3 are caused by difference in the strength of the land-sea breeze flow between the two runs. At night the WRF–YSU predicts a weaker offshore land breeze than does the WRF–MYJ near the western coastline. During the day, the WRF–YSU predicts a stronger sea breeze near the offshore area than does the WRF–MYJ, while over the landside, the WRF–YSU predicts a lower wind speed than does the WRF–MYJ.

Summary The overall goal of the present study is to show through a simulation experiment the value of adaptive management under climatic variability and change. The Northern California water resources management system is used as an example of a multi-agency, multi-site, multi-objective water resources management system that supports a trillion dollar economy to demonstrate the utility of the methods and to exemplify the assessment studies. Simulations are performed using an adaptation of the Integrated Forecast and Reservoir Management (INFORM) system of Northern California with 6-hourly 1.4° input from the CCSM3.0 climate model for historical/control (1970–2019) and future periods (2050–2099). The present paper examines the assessment of the hydroclimatological sensitivities and a companion paper ( Georgakakos et al., this issue ) examines the assessment of reservoir management sensitivities. The future period was based on the moderate CCSM3.0 A1B scenario. The INFORM system includes an intermediate complexity regional model for dynamic downscaling of the CCSM3.0 scenario output to produce surface precipitation and temperature fields with a 10 × 10 km2 resolution, and snow–soil-channel modeling of all the watersheds upstream of the major reservoirs in Northern California. The flow results indicate a shift in the monthly average flow volume toward earlier times in the year and higher flow variability for the future period. Higher average temperatures in the future period and, consequently, earlier snow pack melt are mainly responsible for these flow changes. Both daytime and nighttime average monthly temperatures are higher in the simulation of the future period for the entire domain with the northern catchments experiencing higher temperature increases. Simulated monthly average precipitation for the future period is higher in the southern high Sierras and lower in the northern drainage basins than the historical period precipitation. The uncertainty in the assessments for Northern California mentioned may be estimated with additional simulations similar to those shown in this work using high spatial and temporal resolution output from different climate models.

Summary This article aims to assess the value of adaptive reservoir management versus traditional operation practices in the context of climatic change for Northern California. The assessment uses adaptive decision model being developed for planning and operational management of the Northern California (central valley) water resources system ( HRC-GWRI, 2007 ), coupled with a dynamic downscaling and hydrologic modeling system described in Georgakakos et al. (this issue) . The assessment process compares the water system response in four simulated scenarios, pertaining to two management policies (traditional and adaptive) and two hydrologic data sets (one for the historical and a second for a future scenario). The assessments show that the current policy, which is tuned to the historical hydrologic regime, is unable to cope effectively with the more variable future climate. As a result, the water supply, energy, and environmental water uses cannot be effectively satisfied during future droughts, exposing the system to higher vulnerabilities and risks. By contrast, the adaptive policy maintains similar performance under both hydrologic scenarios, suggesting that adaptive management constitutes an effective mitigation measure to climate change.

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

Asthma is a chronic inflammatory disease affecting the airway, and it is characterized by a wheezing breathing sound, variable airflow obstruction and the presence of inflammatory cells in the submucosa of the bronchi. Viral infection, pollutants and sensitivity to aeroallergens damage the epithelium from childhood, which causes asthma. The pathogenesis of asthma includes pathways of innate stimulation by environmental microbes and irritant pathogens. Damaged epithelial cells produce thymic stromal lymphopoietin (TSLP) and stimulate myeloid dendritic cell maturation through the thymic stromal lymphopoietin receptor (TSLPR) heterocomplex. TSLP-activated myeloid dendritic cells promote naive CD4⁺ T cells to differentiate into T helper type 2 (Th2) phenotype CD4⁺ T cells. Re-exposure to allergens or environmental stimuli causes an adaptive immune response. TSLP-activated dendritic cells expressing the OX40 ligand (OX40L; CD252) trigger naive CD4⁺ T cells to differentiate into inflammatory Th2 effector cells secreting the cytokines interleukin-4, 5, 9, and 13 (IL-4, IL-5, IL-9 and IL-13), and the dendritic cells (DCs) promote the proliferation of allergen-specific Th2 memory cells. Allergen presentation by Th2 cells through its interaction with their receptors in the presence of major histocompatibility complex (MHC) class II on B cells and through costimulation involving CD40 and CD40L interactions results in immunoglobulin class switching from IgM to IgE. DCs and other blood cell subsets express the TSLPR heterocomplex. The regulatory mechanism of the TSLPR heterocomplex on these different cell subsets remains unclear. The TSLPR heterocomplex is composed of the IL-7Ralpha; chain and TSLPR chain. Moreover, two isoforms of TSLP, short isoform TSLP (sfTSLP) and long isoform TSLP (lfTSLP), have roles in atopic and allergic development. Identifying and clarifying the regulation of TSLPR and IL-7Ralpha; in pediatric asthma are still difficult, because the type of blood cell and the expression for each blood cell in different stages of atopic diseases are poorly understood. We believe that further integrated assessments of the regulation mechanism of the TSLPndash;TSLPR heterocomplex axis in vitro and in vivo can provide a faster and earlier diagnosis of pediatric asthma and promote the development of more effective preventive strategies at the onset of allergies.

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.

In the companion paper, we showed that MM5 simulation using a satellite-derived high resolution Texas Forest Service (TFS) land use and land cover (LULC) data set (M2), compared to the MM5 results with the default USGS-LULC (M1), improved representation of the complicated features of the atmospheric planetary boundary layer (PBL) in the Houston ship channel (HSC) area, where large industrial emission sources are concentrated. In the present paper, the study is extended to investigate these effects on air quality simulations. Two emission inputs, namely E1 and E2, are prepared with the M1 and M2 meteorology data, respectively, to reflect the differences in the point source plume rise estimates while keeping the biogenic and mobile emissions the same. Air quality simulations were performed with CMAQ using the M1E1 and M2E2 inputs. The simulation results demonstrate the importance of utilizing high resolution LULC data. In the default LULC data, the HSC area was classified as grass land cover, and MM5 predicted confined mixing, resulting in over-prediction of ozone (O3) precursors, such as NOx (NO plus NO2), and highly reactive volatile organic compounds (HRVOC) species, including ethylene and propylene, over the HSC area. In the TFS data, the area was classified as the impervious “urban” land use and MM5 predicted enhanced mixing of the precursor species, leading to better agreements with measurements. The high resolution LULC also resolves the location of water body near the HSC more accurately, predicting shallower PBL heights than the default LULC during daytime. With favorable wind conditions, the O3 precursors were transported from the HSC emission source towards the area, trapping the pollutants in a confined shallow mixing layer that occasionally led to a rapid photochemical production of O3. The above comparison includes the changes in both meteorological and plume-rise emissions inputs. We performed two additional CMAQ simulations using the same meteorological result (M2) but with different emission point sources E1 and E2 to determine the importance of emission changes on the air quality simulations. The sensitivity tests with the different plume-rise emission inputs due to two different meteorological inputs show little impact on the air quality simulations in this case.

The Houston-Galveston Area (HGA) and several other metropolitan regions in the US are classified, under the Clean Air Act, as non-attainment areas because of the noncompliance of air quality standards due to higher ground-level ozone and particu- late matter concentrations. These regions must reduce their ozone levels within the next 5 to 7 years to comply with EPA standards or they will be penalized with a loss of federal funding and other punitive measures. To study the severity of air pollution problems and to provide tools for the development of emissions control strategies, a research information infrastructure that includes air quality measurement data and various modeling systems is necessary. This paper presents an example of such system that integrates a set of meteorological models, emissions processing systems, air quality models, a trajectory analysis tool, a GIS -based data analy- sis/visualization system, and a collection of observational data sets for the HGA housed in a network of computer systems. We demon- strate the capacity and utilization potential of the information infrastructure to test some of the nongovernmental organizations and public initiated emissions control scenarios proposed by groups including the Task Force for Ozone Reduction Strategies (TFORS), which might have a significant impact on the State Implementation Plan (SIP).

In the present study, we evaluated the protective effect of nitric oxide(NO) against senescence of rice leaves enhanced by water deficit. Dehydration(DH), polyethylene glycol (PEG) and sorbitol (ST) treatments were used toinducewater deficit. Senescence of rice leaves was determined by the decrease ofprotein content. NO donors[N-tert-butyl-α-phenylnitrone (PBN), sodiumnitroprusside (SNP), 3-morpholinosydnonimine (SIN-1), and ascorbic acid +NaNO2] were effective in inhibiting senescence of dehydrated andPEG-treated rice leaves, but had no effect on senescence of ST-treated riceleaves. PEG or DH resulted in a marked increase in malondialdehyde (MDA)contentand decrease in superoxide dismutase (SOD) activity, but ST had no effect onMDAcontent and SOD activity. Treatment with NO donors caused a reduction of PEG-and DH-induced increase in MDA content and decrease in SOD activity. Theprotective effect of NO donors on promotion of senescence, increase in lipidperoxidation and decrease in SOD activity induced by PEG and DH was reversed by2-(4-carboxy-2-phenyl)-4,4,5,5- tetra-methylinmidazoline-1-oxyl-3-oxide, a NOspecific scavenger, suggesting that the protective effect of NO donors isattributed to NO released. The inhibition of PEG- and DH- enhanced senescenceofrice leaves by NO is most likely mediated through increasing SOD activity anddecrease in lipid peroxidation.

The sugar alcohol mannitol and it’s catabolic enzyme mannitol dehydrogenase (MTD), in addition to welldocumented roles in metabolism and osmoprotection, may play roles in hostpathogen interactions. Research suggests that in response to the mannitol that pathogenic fungi secrete to suppress reactive oxygen-mediated host defenses, plants make MTD to catabolize fungal mannitol. Yet previous work suggested that pathogen-secreted mannitol is extracellular, while in healthy plants MTD is cytoplasmic. We have presented results showing that the normally cytoplasmic MTD is exported into the cell wall or extracellular space in response to the endogenous inducer of plant defense responses salicylic acid (SA). This SA-induced secretion is insensitive to brefeldin A, an inhibitor of Golgimediated protein transport. Together with the absence of MTD in Golgi stacks and the lack of a documented extracellular targeting sequence in the MTD protein, this suggests MTD is secreted by a non-Golgi, pathogen-activated secretion mechanism in plants. Here we discuss the potential significance of non-Golgi secretion in response to stress.

In this study, the initiation and maintenance mechanisms of two long-lived, summer heavy rainfall systems over Taiwan are investigated by performing observational data analyses and numerical simulations using a mesoscale model. For both cases of 9-10 July 2008 (Case A) and 18-19 August 2006 (Case B), the heavy rainfall system developed over the western slope of the Central Mountain Range (CMR) under low-level prevailing southwesterly and westerly flows in early afternoon, respectively. These heavy rainfall systems were moving westward toward Taiwan Strait from CMR, while the embedded individual cells were moving in the opposite direction, behaving like a multicell storm. It was also found these individual cells were initiated, enhanced, and then maintained at the leading edge of the near-surface cool outflow and merged with the heavy rainfall systems which became long-lived. These heavy rainfall systems were classified as an upstream propagating precipitation system in a low Froude-number, conditionally unstable flow with high convective available potential energy (CAPE) or Regime I as proposed in a previous study.

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/MS(E) 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/MS(E) 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.

The sugar alcohol mannitol is an important carbohydrate with well-documented roles in both metabolism and osmoprotection in many plants and fungi. In addition to these traditionally recognized roles, mannitol is reported to be an antioxidant and as such may play a role in host-pathogen interactions. Current research suggests that pathogenic fungi can secrete mannitol into the apoplast to suppress reactive oxygen-mediated host defenses. Immunoelectron microscopy, immunoblot, and biochemical data reported here show that the normally symplastic plant enzyme, mannitol dehydrogenase (MTD), is secreted into the apoplast after treatment with the endogenous inducer of plant defense responses salicylic acid (SA). In contrast, a cytoplasmic marker protein, hexokinase, remained cytoplasmic after SA-treatment. Secreted MTD retained activity after export to the apoplast. Given that MTD converts mannitol to the sugar mannose, MTD secretion may be an important component of plant defense against mannitol-secreting fungal pathogens such as Alternaria. After SA treatment, MTD was not detected in the Golgi apparatus, and its SA-induced secretion was resistant to brefeldin A, an inhibitor of Golgi-mediated protein transport. Together with the absence of a known extracellular targeting sequence on the MTD protein, these data suggest that a plant's response to pathogen challenge may include secretion of selected defensive proteins by as yet uncharacterized, non-Golgi mechanisms.

The plant cell wall is a dynamic cellular compartment consisting of a complex matrix of components that can change dramatically in response to environmental stresses. During pathogen attack, for instance, a wide spectrum of proteins that participate in various sequential processes involved in plant defense is secreted into the cell wall. In this study, a mass spectrometry, data-independent acquisition approach known as LC/MS (E) was used to assess temporal changes in the cell wall proteome in response to different levels of an endogenous inducer of plant disease defense responses, salicylic acid (SA). LC/MS (E) was used as a label-free method that enabled simultaneous protein identification and absolute femtomole quantification of each protein secreted into the extracellular matrix. A total of 74 secreted proteins were identified, 63 of which showed increased specific secretion in response to SA. A majority of this induced secretion occurred within 2 h of treatment, indicating that many proteins are involved in the early stages of plant defenses. We also identified a number of apparently nonclassically secreted proteins, suggesting that, as in many nonplant systems, Golgi/ER-independent mechanisms exist for plant protein secretion. These results provide new insight into plant apoplastic defense mechanisms and demonstrate that LC/MS (E) is a powerful tool for obtaining both relative and absolute proteome-scale quantification that can be applied to complex, time- and dose-dependent experimental designs.

An air quality forecasting system for Eastern Texas has been developed utilizing the customized MM5/SMOKE/CMAQ modeling system. We performed 2-day air quality forecasting simulations for the 12 km Eastern Texas regional domain, and the 4 km Houston-Galveston area (HGA) domain. Dynamic boundary conditions were provided by the 36 km resolution conterminous US (CONUS) domain CMAQ simulations. Initial meteorological conditions were provided by the daily Eta forecast results. A set of complex operational scripts was used to allow automatic operation of the data download, sequencing processors, performing simulations and graphical analyses, building database archives, and presenting on the web. The public access web-based user interface has been developed to link the air quality forecasting results with other GIS databases including population and health effects databases. Three different streams of air quality forecasting with slightly different meteorological model options were performed during the summer and fall 2005. The ozone forecasting results were evaluated daily with meteorological and air quality measurements from the surface continuous air monitoring sites in HGA.