A simple approach to assess N load capacity of rice paddy fields in the southern Taihu Lake watershed.

High nitrogen (N) leaching from irrigated agricultural soils is the result of N input exceeding soil N load capacity (NLC). A simple approach was developed in this research to assess the NLC of paddy soils in the southern Taihu Lake watershed. Paddy soils were classified into four types (Submergenic, Illuvium, Gleyed, and Percogenic) and 28 soil samples representing all four types were collected from across the region. The NLC values of the paddy soils were assessed using a split-line model and the spatial variability of the NLC among various rice paddy soils in the region was also evaluated with Kriging analysis. Results showed the NLC of paddy soils were both soil type and background N content related. The critical N sorption values (NLC plus soil N background) of the Gleyed, Illuvium, Submergenic, and Percogenic paddy soil samples varied from 283.1 to 315.6 mg kg(-1), 203.0 to 270.2 mg kg(-1), 240.6 to 254.4 mg kg(-1), and 177.4 to 186.2 mg kg(-1), respectively. However, on average the NLC of paddy soils in the region was 80.3 mg kg(-1), and the corresponding environmental N load threshold was around 110 kg N ha(-1). Geo-statistic results showed that the NLCs were unevenly distributed throughout the rice paddy dominated areas of the southern Taihu Lake watershed. The NLC assessment approach and spatial distribution information provided helpful guidance to set an environmental N threshold for best N management and hence reduce degradation of water for the whole rice ecosystem.

Genomic distribution of AML1-ETO fusion protein binding sites / 中国实验血液学杂志

This study was purposed to characterize the genomic distribution of the binding sites for AML1-ETO fusion protein on chromosome 2, 9 and 19, and to further gain insights into the characteristics of transcriptional regulation by AML1-ETO in acute myeloid leukemia so as to provide theoretical basis for the development of targeted therapy and optimization for treatment. Chromatin immunoprecipitation (ChIP) coupled with high density tiling arrays (chip), also known as ChIP-chip, was utilized in this study. ChIP-DNA enriched by an anti-ETO antibody and total genomic DNA of Kasumi cells were hybridized to tiling arrays, tiled through chromosome 2, 9 and 19. The ChIP enriched regions were identified using a model based analytical tool (MAT). Genomic distribution of the ChIP regions was analyzed using publicly available CEAS web server. The Gene Ontology (GO) enrichment analysis was performed to excavated the biological significance. The results indicated that a total of 588 enriched regions were identified on chromosome 2, 9 and 19 by the anti-ETO antibody. A number of the identified regions were located within enhancers (48.86%) or introns (37.35%), much smaller fractions were within proximal promoters (5.96%) or exons (5.49%). Functional enrichment analysis showed that cell proliferation and signal transduction biological pathways were enriched in potential genes of AML-ETO. It is concluded that half of the AML1-ETO binding sites are located within known transcriptional regulatory regions (promoter, 5' UTR and enhancer), while almost another half were within the sequences which were not previously reported as regulatory regions. The potential target molecular network of AML1-ETO is involved in several essential biological processes.