Plant microremains provide direct evidence for the functions of stone knives from the Lajia site,northwestern China

A large number of stone knives have been recovered from Neolithic archaeological sites in East Asia. However, direct evidence regarding the functions of the stone knives has been scarce, and hence, their functions have remained controversial. In this study, we recovered and analysed ancient starch grains and phytoliths from residues adhering to stone knives excavated from the Lajia site, Qinghai Province, northwest China, thus providing direct evidence for the functions of the knives. Our anal- yses were based on the following： （1） an assemblage of 278 identifiable starch grains, representing grains from the stems of foxtail millet （Setaria italica） and broomcorn millet （Panicum miliaceum） （65.1% of the total） and the stems of Hordeum and Triticum species （3.6 % of the total）, and （2） an assemblage of 361 identifiable phytoliths, the majority of which were from the stems and leaves of plants such as Panicoideae and related taxa （96 % of the total）. Our study demonstrates that one of the functions of the stone knives was the harvesting crops. In addition, a few starch grains from food legumes and roots （3.4 % of the total） indicate that the stone knives were also likely used to process, peel and cut some foods.     

Relation between human existence and environment viewing from the distribution of prehistoric archaeological sites in the Three Gorges reservoir region of the Yangtze River,China

Based on archaeological research findings in the Three Gorges region as well as the distribution of prehistoric sites in this area,the following conclusion can be derived:the unique physical and geographical conditions and variations in the Three Gorges region make local people of different ages seek their survival and development in the favorable environment along the riverbanks.Environment evolution has direct impact on the selection of location for survival.The increase of sites quantity reflects the favorable natural environment,but the decrease just reflects the consequence of such natural disasters as flood.     

单县汉墓群发掘研究

2003年7月至11月，山东省菏泽市文物事业管理处、单县博物馆联合成立单县汉墓群考古发掘队，对位于单县单父路路基下的古墓进行抢救性考古发掘，共清理汉墓61座，出土文物500件。规模之大，出土文物之丰富，是菏泽市考古史上发掘古墓葬之最。单县汉墓群具有上下叠压、分布散乱的特点。重视和加强对单县汉墓群墓主的研究，是对单县汉墓群整体研究的重大突破。对研究菏泽市在汉代的社会状况，具有重大意义。     

Chenguodaite (Ag_9FeTe_2S_4):a new tellurosulfide mineral from the gold district of East Shandong Peninsula,China

Chenguodaite, approved by IMA-CNMMN (2004-042a), was discovered in the Bunan quartz vein-type gold deposit in the gold district of East Shandong Peninsula. The mineral occurs in high grade Au-Ag-Cu ores, coexisting with galena, chalcopyrite, hessite, electrum, unnamed Ag6TeS2 and Ag16FeBiTe3S8, enclosed and replaced by native silver and acanthite. In the reflected light microscope, the mineral has light gray color, indistinguishable anistropism and hardness around 2―3. The color indices of chenguodaite relative to ICE C illuminator are: x=0.3027, y=0.3076, Y=25.78%, λd=474 nm, Pe=3.68%, similar to those of canfieldite. The average chemical composition from 16 microprobe analyses is Ag8.97Fe1.00Te1.99S4.04, idealized to Ag9FeTe2S4. The polycrystalline X-ray diffraction of chenguodaite by Gandolfi camera and synchrotron oscillation photography results in 67 reflections with the 12 strongest being (relative intensity in bracket): 6.742(69), 6.416(39), 5.951(33), 3.265(100), 2.981(24), 2.649(22), 2.25(24), 2.188(71), 2.142(22), 2.123(31), 2.044(23), 1.949(33), which are indexed to a primitive orthorhombic cell with a=12.769 (2) , b= 14.814(2), c= 16.233 (1) , V= 3070.63, Z = 9, Dcal.=6.85 g/cm3. The name is for the late Prof. Chen Guoda, a famous Chinese geologist and the founder of Diwa-Geodepression theory of tectonics.     

Neurobiological disruptions induced in brains of the rats fed with mercury contaminated rice collected from experimental fields in Guizhou Province, China

Guizhou Province, located in the southwestern China, is an important mercury （Hg） production center. High levels of Hg were found in local environmental and biomass samples. The neurobiological disruptions induced in brains of rats fed with Hg polluted rice collected from two experimental plots in Guizhou Province were studied. The plots are close to the Hg mine of Wanshang area and a chemical plant （where Hg is used as a catalyst for the production of acetaldehyde） of Qingzhen area. Rats were fed for 30 d before toxicological end points were tested. The results showed that the accumulations of Hg in rat＇s brain of Qingzhen chemical plant group and Wanshang mine group were significantly higher than those of Shanghai group （control group） （P〈0.01）. The neural transmitters, including acetylcholine （Ach）, acetylcholine enzyme （AchE）, nitric oxide and nitricoxide synthase （NOS）, in rat＇s brain were significantly affected. Oxidative stress was observed in the exposure groups. The expression levels of the immediately early gene （lEG）, c-fos and c-FOS proteins were induced by the Hg polluted rice. It was noted that the lEG （c-fos） participated in the neurotoxic process induced by the Hg polluted rice. lEG response to Hg might be dependent on interactions between neural transmitter and oxidative damage, c.fos could be used as an effective index of detecting and assessing the neurotoxicity of Hg. The results suggested that it should be alert to mental health problem in human beings eating Hg-polluted food. More efforts are necessary to protect the local ecosystem and human health in the Hg polluted areas such as Wangshan and Qingzhen in Guizhou Province of China.