A peripheral mononeuropathy was produced in adult rats by placing loosely constrictive ligatures around the common sciatic nerve. The postoperative behavior of these rats indicated that hyperalgesia, allodynia and, possibly, spontaneous pain (or dysesthesia) were produced. Hyperalgesic responses to noxious radiant heat were evident on the second postoperative day and lasted for over 2 months. Hyperalgesic responses to chemogenic pain were also present. The presence of allodynia was inferred from the nocifensive responses evoked by standing on an innocuous, chilled metal floor or by innocuous mechanical stimulation, and by the rats' persistence in holding the hind paw in a guarded position. The presence of spontaneous pain was suggested by a suppression of appetite and by the frequent occurrence of apparently spontaneous nocifensive responses. The affected hind paw was abnormally warm or cool in about one-third of the rats. About one-half of the rats developed grossly overgrown claws on the affected side. Experiments with this animal model may advance our understanding of the neural mechanisms of neuropathic pain disorders in humans.

A regional haze with daily PM 2.5 (fine particulate matters with diameters less than 2.5 μm)exceeding 500 μg/m 3 lasted for several days in January 2013 over North China, offering an opportunity to evaluate models. Observations show that inorganic aerosols (sulfate, nitrate, and ammonium) are the largest contributor to PM 2.5 during the haze period, while sulfate shows the largest enhancement ratio of 5.4 from the clean to haze period. The nested-grid GEOS-Chem model reproduces the distribution of PM 2.5 and simulates up to 364 μg/m 3 of daily maximum PM 2.5 . Yet on average, the model is a factor of 3 and 4 lower in PM 2.5 and fails to capture the large sulfate enhancement from the clean to haze period. A doubling of SO 2 emissions over North China, along with daily meteorology corrections, would be required to reconcile model results with surface SO 2 observations, but it is not sufficient to explain the model discrepancy in sulfate. Heterogeneous uptake of SO 2 on deliquesced aerosols is proposed as an additional source of sulfate under high-relative humidity conditions during the haze period. Parameterizing this process in the model improves the simulated spatial distribution and results in a 70% increase of sulfate enhancement ratio and a 120% increase in sulfate fraction in PM 2.5 . Combined adjustments in emissions, meteorology, and sulfate chemistry lead to higher sulfate by a factor of 3 and 50% higher PM 2.5 , significantly reducing the model's low bias during the haze.

Estimating exposures to PM2.5 within urban areas requires surface PM2.5 concentrations at high temporal and spatial resolutions. We developed a mixed effects model to derive daily estimations of surface PM2.5 levels in Beijing, using the 3 km resolution satellite aerosol optical depth (AOD) calibrated daily by the newly available high-density surface measurements. The mixed effects model accounts for daily variations of AOD-PM2.5 relationships and shows good performance in model predictions (R(2) of 0.81-0.83) and cross-validations (R(2) of 0.75-0.79). Satellite derived population-weighted mean PM2.5 for Beijing was 51.2 μg/m(3) over the study period (Mar 2013 to Apr 2014), 46% higher than China's annual-mean PM2.5 standard of 35 μg/m(3). We estimated that more than 19.2 million people (98% of Beijing's population) are exposed to harmful level of long-term PM2.5 pollution. During 25% of the days with model data, the population-weighted mean PM2.5 exceeded China's daily PM2.5 standard of 75 μg/m(3). Predicted high-resolution daily PM2.5 maps are useful to identify pollution "hot spots" and estimate short- and long-term exposure. We further demonstrated that a good calibration of the satellite data requires a relatively large number of ground-level PM2.5 monitoring sites and more are still needed in Beijing.

Despite the importance of precipitation and moisture transport over the Tibetan Plateau for glacier mass balance, river runoff and local ecology, changes in these quantities remain highly uncertain and poorly understood. Here we use observational data and model simulations to explore the close relationship between summer rainfall variability over the southwestern Tibetan Plateau (SWTP) and that over central-eastern India (CEI), which exists despite the separation of these two regions by the Himalayas. We show that this relationship is maintained primarily by ‘up-and-over' moisture transport, in which hydrometeors and moisture are lifted by convective storms over CEI and the Himalayan foothills and then swept over the SWTP by the mid-tropospheric circulation, rather than by upslope flow over the Himalayas. Sensitivity simulations confirm the importance of up-and-over transport at event scales, and an objective storm classification indicates that this pathway accounts for approximately half of total summer rainfall over the SWTP.