Investigating the climatology of North China's urban inland lake based on six years of observations.

There are unclear characteristics of the effect of lake breeze in small urban inland lakes due to little research on lake breezes. In this work, six-year observations were performed to study the comprehensive climatologic characteristics of lake breezes on North China's urban inland lake, Lake Hengshui (75 km2). By removing background winds calculated by ERA5 data and successfully recording the lake-land breeze cycle, we devised a succinct and effective approach for distinguishing lake-land breezes. Lake-land breeze had a high annual occurrence frequency of 13.4%-24.7% and a yearly mean lake-breeze speed of 1.6 m/s and yearly mean lake-breeze duration of 4.8 h; spring has the highest frequency and summer has the lowest frequency because of the greater thermal differences between lake and land in spring. The lake breeze mostly started at 06:00-07:00 and 10:00-13:00 (LST), showing a double-peak pattern, and ended at 17:00-19:00 (LST). On the other hand, the land breezes mainly started at 00:00-01:00 (LST) and ended at 05:00-06:00. The distance between each station and the lake has a negative correlation to the frequency and duration of the lake-land breeze, showing the higher frequency and duration at the near stations and the lower frequency and duration at the stations far from the lake. The land breeze has similar spatial characteristics. Winter has relatively lower seasonal average wind speeds of the lake breeze at most stations; spring and winter have high average wind speeds of the land breeze at each station, while summer and autumn have low. The study of the city lake's lake-land breeze will shed new insights into addressing the urban layout.

Investigating the impacts of coal-fired power plants on ambient PM2.5 by a combination of a chemical transport model and receptor model.

Aimed at evaluating the impacts of coal-fired power plants on urban air quality and human health, a one-month intensive observation campaign was conducted in a typical polluted city located in the 2 + 26 city cluster (Beijing, Tianjin and 26 other cities) of the North China Plain in December 2017. The observation results illustrated that the coal-fired power plant in this city increased the monthly average fine particulate matter (PM2.5) concentration by ~5% at the city scale. The impacts differed under various diffusion conditions. A three-dimensional nested air quality condition model (the Nested Air Quality Perdition Model System or NAQPMS) with source apportionment was employed to analyze the impacts. The results indicated that power plants had the largest effect on regional air quality during the severe-pollution period, while any influence could be ignored during periods with excellent dissipation under robust winds. PM2.5 contributed by the power plant mainly occurred below 150 m, diffused 100 km away, and reached a level of approximately 5 µg m-3 during the light-pollution period. During the accumulation period, the plume reached a height of 500 m, diffused to the downwind area approximately 100 km away within half a day, and contributed at most 40 µg m-3 to PM2.5. The affected area expanded to 250 km during the severe-pollution period, and the contribution to PM2.5 was at least 10 µg m-3 at different distances. The affected height reached approximately 500 m, with PM2.5 exceeding 10 µg m-3, mainly constrained below 150 m. Overall, regional integrated control strategies should be implemented for the power plants in the 2 + 26 city cluster during pollution episodes to further improve air quality.

Enhanced Salt Tolerance of Rhizobia-inoculated Soybean Correlates with Decreased Phosphorylation of the Transcription Factor GmMYB183 and Altered Flavonoid Biosynthesis.

Soybean (Glycine max (L.) Merrill) is an important component of the human diet and animal feed, but soybean production is limited by abiotic stresses especially salinity. We recently found that rhizobia inoculation enhances soybean tolerance to salt stress, but the underlying mechanisms are unaddressed. Here, we used quantitative phosphoproteomic and metabonomic approaches to identify changes in phosphoproteins and metabolites in soybean roots treated with rhizobia inoculation and salt. Results revealed differential regulation of 800 phosphopeptides, at least 32 of these phosphoproteins or their homologous were reported be involved in flavonoid synthesis or trafficking, and 27 out of 32 are transcription factors. We surveyed the functional impacts of all these 27 transcription factors by expressing their phospho-mimetic/ablative mutants in the roots of composite soybean plants and found that phosphorylation of GmMYB183 could affect the salt tolerance of the transgenic roots. Using data mining, ChIP and EMSA, we found that GmMYB183 binds to the promoter of the soybean GmCYP81E11 gene encoding for a Cytochrome P450 monooxygenase which contributes to the accumulation of ononin, a monohydroxy B-ring flavonoid that negatively regulates soybean tolerance to salinity. Phosphorylation of GmMYB183 was inhibited by rhizobia inoculation; overexpression of GmMYB183 enhanced the expression of GmCYP81E11 and rendered salt sensitivity to the transgenic roots; plants deficient in GmMYB183 function are more tolerant to salt stress as compared with wild-type soybean plants, these results correlate with the transcriptional induction of GmCYP81E11 by GmMYB183 and the subsequent accumulation of ononin. Our findings provide molecular insights into how rhizobia enhance salt tolerance of soybean plants.