Abstract. Current estimates of agricultural ammonia (NH 3 ) emissions in China differ by more than a factor of 2, hindering our understanding of their environmental consequences. Here we apply both bottom-up statistical and top-down inversion methods to quantify NH 3 emissions from agriculture in China for the year 2008. We first assimilate satellite observations of NH 3 column concentration from the Tropospheric Emission Spectrometer (TES) using the GEOS-Chem adjoint model to optimize Chinese anthropogenic NH 3 emissions at the 1/2 • × 2/3 • horizontal resolution for MarchOctober 2008. Optimized emissions show a strong summer peak, with emissions about 50 % higher in summer than spring and fall, which is underestimated in current bottom-up NH 3 emission estimates. To reconcile the latter with the topdown results, we revisit the processes of agricultural NH 3 emissions and develop an improved bottom-up inventory of Chinese NH 3 emissions from fertilizer application and livestock waste at the 1/2 • × 2/3 • resolution. Our bottom-up emission inventory includes more detailed information on crop-specific fertilizer application practices and better accounts for meteorological modulation of NH 3 emission factors in China. We find that annual anthropogenic NH 3 emissions are 11.7 Tg for 2008, with 5.05 Tg from fertilizer application and 5.31 Tg from livestock waste. The two sources together account for 88 % of total anthropogenic NH 3 emissions in China. Our bottom-up emission estimates also show a distinct seasonality peaking in summer, consistent with topdown results from the satellite-based inversion. Further evaluations using surface network measurements show that the model driven by our bottom-up emissions reproduces the observed spatial and seasonal variations of NH 3 gas concentrations and ammonium (NH + 4 ) wet deposition fluxes over China well, providing additional credibility to the improvements we have made to our agricultural NH 3 emission inventory.
Alterations in long non-coding RNAs (lncRNAs) are associated with human carcinogenesis. One group of lncRNAs, which are antisense in orientation to coding mRNAs (ASs), have been recently described in cancers but are poorly understood. We sought to identify ASs involved in human gastric cancer (GC) and to elucidate their mechanisms of action in carcinogenesis. We performed massively parallel RNA sequencing in GCs and matched normal tissues, as well as in GC-derived and normal gastric epithelial cell lines. One AS, designated KRT7-AS, was selected due to its marked upregulation and concordant expression with its cognate sense counterpart, KRT7, in GC tissues and cell lines. KRT7-AS formed an RNA-RNA hybrid with KRT7 and controlled KRT7 expression at both the mRNA and the post-transcriptional levels. Moreover, forced overexpression of the KRT7-overlapping region (OL) of KRT7-AS (but not its non-KRT7-overlapping portions) increased keratin 7 protein levels in cells. Finally, forced overexpression of full-length (FL) KRT7-AS or OL KRT7-AS (but not its non-KRT7-overlapping regions) promoted GC cell proliferation and migration. We conclude that lncRNA KRT7-AS promotes GC, at least in part, by increasing KRT7 expression.
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