A field experiment was conducted to study the accumulation of toxic heavy metals by winter wheat (Triticum aestivum L.) grown in the agricultural soil in the suburb of Zhengzhou City, China. The quantities of heavy metals (Cd, Cr, Pb, As, Hg) were determined in different parts of wheat plant. The content of five toxic metals was found significantly higher in roots than in the aerial parts of wheat (stems and leaves, and grains). Additionally, wheat roots were enriched in Cd, Pb, and Hg from the soil, while Cr and As were hardly taken up by the roots. On the other hand, the winter wheat transported five toxic heavy metals very weakly from root to grain in the various irrigation regions.

Metallic glass-reinforced metal matrix composites are an emerging class of composite materials. The metallic nature and the high mechanical strength of the reinforcing phase offers unique possibilities for improving the engineering performance of composites. Understanding the structure at the amorphous/ crystalline interfaces and the deformation behavior of these composites is of vital importance for their further development and potential application. In the present work, Zr-based metallic glass fibers have been introduced in Al7075 alloy (Al-Zn-Mg-Cu) matrices using spark plasma sintering (SPS) producing composites with low porosity. The addition of metallic glass reinforcements in the Al-based matrix significantly improves the mechanical behavior of the composites in compression. High-resolution TEM observations at the interface reveal the formation of a thin interdiffusion layer able to provide good bonding between the reinforcing phase and the Al-based matrix. The deformation behavior of the composites was studied, indicating that local plastic deformation occurred in the matrix near the glassy reinforcements followed by the initiation and propagation of cracks mainly through the matrix. The reinforcing phase is seen to inhibit the plastic deformation and retard the crack propagation. The findings offer new insights into the mechanical behavior of metal matrix composites reinforced with metallic glasses.Al-based metal matrix composites (MMCs) belong to a technologically attractive class of materials with low density, high specific strength and high wear resistance 1 . Improved mechanical properties can be achieved by combining the properties of ductile metallic matrices with the high strength of reinforcements, such as SiC, Al 2 O 3 or carbon nanotubes. In the past two decades, metallic glasses have been widely studied and are considered as promising candidates for the next-generation structural materials due to their high strength, large elastic limit and high corrosion resistance 2 . Metallic glasses have been suggested as an alternative reinforcement for metal matrix composites that can significantly enhance the mechanical strength while retaining desirable plastic strain before fracture [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] . The metallic nature of the reinforcing phase plays an important role in achieving good bonding between the matrix and the glassy reinforcement and overcoming many of the usual shortcomings of the conventional ceramic reinforcing phases, such as interfacial reactions, agglomeration of particles and porosity 5,18 . However, up to date, the amorphous/crystalline interfaces in MMCs have not been well studied at the atomic scale. Such studies would be of great fundamental interest and vital importance for advanced structural applications. The nature of the interface plays a significant role determining the mechanical behavior and deformation mechanisms of composite materials. For example, poor adhesion, pores or the formation of brittle intermetallic phases at the interf...

Dongxiang Spotted, Pingxiang Two-End-Black and Yushan Black pigs are three indigenous breeds in Jiangxi Province, China, that have been listed in the national conservation program for Chinese indigenous livestock germplasm. Here, we investigated the genetic diversity and population structure of the nucleus populations of these three breeds in a worldwide context of European and Chinese pigs using Illumina Porcine 60K chips. Our data indicate that Dongxiang Spotted and Yushan Black pigs have recently experienced severe inbreeding. The two breeds show large runs-of-homozygosity values, long-range extents of linkage disequilibrium and reduced observed heterozygosity. In contrast, Pingxiang Two-End-Black pigs are rich in genetic diversity and have few inbred individuals. Both phylogenetic and admixture analyses illustrate that Dongxiang Spotted and Yushan Black pigs are genetically close to their geographical neighbors in East China and that Pingxiang Two-End-Black pigs have a close relationship with three other Two-End-Black breeds in central China. Finally, we reconstructed the family structures of the three breeds and propose a reliable breeding strategy to better conserve these breeds.

The phylogeography of common and widespread species helps to elucidate the history of local flora and vegetation. In this study, we selected Cotinus coggygria, a species widely distributed in China's warm-temperate zone. One chloroplast DNA (cpDNA) region and ecological niche modelling were used to examine the phylogeographic pattern of C. coggygria. The cpDNA data revealed two phylogeographic groups (Southern and Northern) corresponding to the geographic regions. Divergence time analyses revealed that divergence of the two groups occurred at approximately 147,000 years before the present (BP), which coincided with the formation of the downstream area of the Yellow River, indicating that the Yellow River was a weak phylogeographic divide for C. coggygria. The molecular data and ecological niche modelling also indicated that C. coggyria did not experience population expansion after glaciations. This study thus supports the fact that Pleistocene glacial cycles only slightly affected C. coggygria, which survived in situ and occupied multiple localised glacial refugia during glaciations. This finding is contrary to the hypothesis of large-scale range habitat contraction and retreat into a few main refugia.

To clarify the environmental fate of the Cry1Ac protein from Bacillus thuringiensis subsp. kurstaki (Bt) contained in transgenic rice plant stubble after harvest, degradation was monitored under Þeld conditions using an enzyme-linked immunosorbent assay. In stalks, Cry1Ac protein concentration decreased rapidly to 50% of the initial amount during the Þrst month after harvest; subsequently, the degradation decreased gradually reaching 21.3% when the experiment was terminated after 7 mo. A similar degradation pattern of the Cry1Ac protein was observed in rice roots. However, when the temperature increased in April of the following spring, protein degradation resumed, and no protein could be detected by the end of the experiment. In addition, a laboratory experiment was conducted to study the persistence of Cry1Ac protein released from rice tissue in water and paddy soil. The protein released from leaves degraded rapidly in paddy soil under ßooded conditions during the Þrst 20 d and plateaued until the termination of this trial at 135 d, when 15.3% of the initial amount was still detectable. In water, the Cry1Ac protein degraded more slowly than in soil but never entered a relatively stable phase as in soil. The degradation rate of Cry1Ac protein was signiÞcantly faster in nonsterile water than in sterile water. These results indicate that the soil environment can increase the degradation of Bt protein contained in plant residues. Therefore, plowing a Þeld immediately after harvest could be an effective method for decreasing the persistence of Bt protein in transgenic rice Þelds.