The adoption of cereal cultivation was one of the most important cultural processes in history, marking the transition from hunting and gathering by Mesolithic foragers to the food-producing economy of Neolithic farmers. In the Lower Yangtze region of China, a centre of rice domestication, the timing and system of initial rice cultivation remain unclear. Here we report detailed evidence from Kuahuqiao that reveals the precise cultural and environmental context of rice cultivation at this earliest known Neolithic site in eastern China, 7,700 calibrated years before present (cal. yr bp). Pollen, algal, fungal spore and micro-charcoal data from sediments demonstrate that these Neolithic communities selected lowland swamps for their rice cultivation and settlement, using fire to clear alder-dominated wetland scrub and prepare the site for occupation, then to maintain wet grassland vegetation of paddy type. Regular flooding by slightly brackish water was probably controlled by 'bunding' to maintain crop yields. The site's exploitation ceased when it was overwhelmed by marine inundation 7,550 cal. yr bp. Our results establish that rice cultivation began in coastal wetlands of eastern China, an ecosystem vulnerable to coastal change but of high fertility and productivity, attractions maximized for about two centuries by sustained high levels of cultural management of the environment.

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The growth performance, fatty acid composition, hepatic lipid content, hepatic somatic index and lipid peroxidation in Russian sturgeon were investigated using diets containing three lipid levels 50 g kg À1 (L5), 150 g kg À1 (L15) and 250 g kg À1 (L25) and three n-3/n-6 fatty acid ratios (1 : 3, 1 : 1 and 3 : 1) for 8 weeks. Weight gain significantly increased with the increase in dietary lipid levels at n-3/n-6 fatty acid ratios of 1 : 3 and 1 : 1, but not at the 3 : 1 ratio. Correspondingly, fish survival gradually decreased with the increase in dietary lipid at the 3 : 1 n-3/n-6 fatty acid ratio. The dietary lipid level significantly affected the composition of whole-body fatty acid. The retention of highly unsaturated fatty acid dramatically decreased at the level of 250 g kg À1 dietary lipid. The liver malondialdehyde increased with the increase in dietary lipid levels and the n-3/n-6 fatty acid ratios. The contents of lipid and triglyceride in the liver and the hepatic somatic index also increased with the increase in dietary lipid. The diet combination of L25 + 3 : 1 showed the highest aspartate transaminase and alanine transaminase, indicatives of hepatic injury. This study indicates that the L25 + 1 : 3 diet can improve fish growth performance, whereas the L25 + 3 : 1 diet may lead to poor growth performance due to high lipid peroxidation.

tumors in BALB/c nude mice, the radiosensitizing effect of PD98059 was investigated in vivo. Results: Our study found the delayed xenograft tumor growth in PDAC was significantly inhibited by fractionated radiation, while reactivated after the radiotherapy ended, inducing tumor relapse. The Mek kinase inhibitor PD98059 significantly radiosensitized PDAC cell lines by enhancing DSBs and inhibiting DNA damage repair, resulting in decreased clonogenic survival and increased tumor growth inhibitory effect. In vivo studies showed PD98059 significanlty delayed xenograft tumor growth with decreased tumor weight and prolonged tumor growth delay time. Conclusion: Our study discovered targeting MAPK signaling pathway could significantly improve tumor radioresponse of PDAC.