To improve brown planthopper (Nilaparvata lugens St al; BPH) resistance of an elite indica cultivar of South China, Hemeizhan (HMZ), we applied marker-assisted backcross (MABC) to incorporate three BPHresistance genes (Bph3, Bph14 and Bph15) into the genetic background of HMZ. In the third backcross (BC 3 ) generation, we obtained near-isogenic lines (Bph3-NIL, Bph14-NIL, Bph15-NIL and Bph14 + Bph15-NIL) with more than 96% recovery of recurrent parent genome, and pyramided lines (Bph3 + Bph14-PYL, Bph3 + Bph15-PYL and Bph3 + Bph14 + Bph15-PYL) with more than 89% recovery of recurrent parent genome. These lines showed stronger resistance against BPH than HMZ at seedling and booting stages. The rank of resistance gene effect was Bph3 + Bph14 + Bph15 ≥ Bph3 + Bph15 ≥ Bph3 + Bph14 ≥ Bph14 + Bph15 ≥ Bph3 ≥ Bph15 ≥ Bph14 > none. Compared with HMZ, only Bph3 + Bph14 + Bph15-PYL had a significant difference in yield per plant, and the lines carrying Bph3 had higher amylose contents, indicating that Bph3 was tightly linked to Wx a allele. These improved lines are good intermediate sources of broad-spectrum and durable BPH resistance to improve other indica cultivars. Our results demonstrate that MABC is a very efficient approach to improve BPH resistance of elite rice cultivar.

Sparse Matrix-Vector multiplication (SpMV) is one of the most significant yet challenging issues in computational science area. It is a memory-bound application whose performance mostly depends on the input matrix and the underlying architecture. Many researchers have paid more attentions on exploring a variety of optimization techniques to SpMV. One of the most promising respects is how to adapt the storage format to satisfy the underlying architecture. Alterative storage formats can largely lessen memory pressure, however, the computational resources are often underutilized.Therefore, a new storage format, which is called Compressed Sparse Row with Segmented Interleave Combination (SIC), is proposed. Stemming from Compressed Sparse Row format (CSR), SIC format employs an interleave combination pattern that combines certain amount of CSR rows to form a new SIC row. In order to further improve performance, segmented processing is also brought in. According to the empirical data, we also develop an automatic SIC-based SpMV suitable for all the matrices. Experimental results show that our approach outperforms the NVIDIA CSR vector kernel, achieving up to 12.6× speedup. It also demonstrates a comparable performance with the Hybrid format, even with the highest 2.89× speedup.

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We report infection of humans with highly pathogenic avian influenza A(H7N9) virus in Shaanxi, China, in May 2017. We obtained complete genomes for samples from 5 patients and from live poultry markets or farms in 4 cities. Results indicate that H7N9 is spreading westward from southern and eastern China.

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