Coherence between solar activity and the East Asian winter monsoon variability in the past 8000 years from Yangtze River-derived mud in the East China Sea

AMS(14)C dating and grain-size analysis for Core PC-6, located in the middle of a mud area on the inner shelf of the East China Sea (ECS), were used to rebuild the Holocene history of the East Asian winter monsoon (EAWM). The 7.5-m core recorded the history of environmental changes during the postglacial transgression. The core's mud section (the upper 450 cm) has been formed mainly by suspended sediment delivered from the Yangtze River mouth by the ECS Winter Coastal Current (ECSWCC) since 7.6 kyr BP. Using a mathematical method called "grain size vs. standard deviatioW', we can divide the Core PC-6's grain-size distribution into two populations at about 28 mu m. The fine population (< 28 mu m) is considered to be transported by the ECSWCC as suspended loads. Content of the fine population changes little and represents a stable sedimentary environment in accord with the present situation. Thus, variation of mean grain-size from the fine population would reflect the strength of ECSWCC, which is mainly controlled by the East Asian winter monsoon. Abrupt increasing mean grain size in the mud section is inferred to be transported by sudden strengthened ECSWCC, which was caused by the strengthened EAWM. Thus, the high resolution mean grain-size variation might serve as a proxy for reconstruction of the EAWM. A good correlation between sunspot change and the mean grain-size of suspended fine population suggests that one of the primary controls on centennial- to decadal-scale changes of the EAWM in the past 8 ka is the variations of sun irradiance, i.e., the EAWM will increase in intensity when the number of sunspots decreases. Spectral analyses of the mean grain-size time series of Core PC-6 show statistically significant periodicities centering on 2463, 1368, 128, 106, 100, 88-91, 7678, and 70-72 years. The EAWM and the East Asian summer monsoon (EASM) agree with each other well on these cycles, and the East Asian Monsoon (EAM) and the Indian Monsoon also share in concurrent cycles in Holocene, which are in accord with the changes of the sun irradiance. (c) 2005 Elsevier B.V. All rights reserved.

海水鱼细胞系FG、SPH和RSBF的特性分析及其在典型海洋污染物毒性检测上的应用

鱼类细胞培养已成为鱼类病毒学、肿瘤学、毒理学、遗传学和免疫学等研究的重要手段。本文首先从形态、蛋白质（同工酶）和DNA（RAPD分析）三个层次水平对牙鲆鳃细胞系FG、鲈鱼心脏细胞系SPH和真鲷鳍细胞系RSBF的特性进行了分析，并分别与其所对应的原代培养组织作了比较。形态、蛋白质和DNA分析的结果表明：(1) 三株海水鱼细胞系的乳酸脱氢酶(LDH)酶谱彼此明显不同，可作为对它们进行种属鉴定和交叉污染鉴别的有效遗传标记；(2)与所对应的原代培养组织的LDH酶谱相比，细胞系FG的LDH酶谱维持不变，而细胞系SPH和FRSBF的LFH酶酶谱变化较大；(3)与所对应的原代培养细胞的形态相比，细胞系FG的细胞形态没有明显改变，而细胞系SPH和RSBF的细胞形态则发生了明显改变；(4)60个DNA随机引物对三株细胞系及其原代培养组织的RAPD分析表明，有35－48％的引物在细胞系及其原代培养组织之间产生完全相同的RAPD指纹，为这三株细胞系种属来源的鉴别奠定了基础，另有27－32％的引物在细胞系及其原代培养组织之间产生不同的RAPD指纹，表明这三株细胞系中发生了遗传变异；(5)FG、SPH和RSBF三株细胞系与其所来源鱼类个体间的总遗传相似性指数大小为0.825-0.851，这表明了它们之间的同源性，同时为我们采用RAPD技术对其它细胞系进行种属鉴定提供了可供参考的实验数据；(6)筛选得到四个随机引物S－91、S－223、S－228和S－237，分别可参在这三株海水鱼细胞系中扩增得到特异性的彼此明显不同的RAPD指纹，这些特异性RAPD指纹在各细胞系与其原代培养组织之间，以及在细胞系的传代培养过程中是稳定的，因而这四个引物对于这三株细胞系的种属鉴定、交叉污染检测以及监测它们与其来源鱼类个体之间的遗传变异将非常有用。其次，170代以后的FG细胞发生了自发性肿瘤转化，具有了在细胞单层上聚集生长和堆积生长的能力，本文对转化前后细胞的形态、贴壁依赖性(软琼脂克隆形成实验)和遗传物质稳定性(RAPD分析)进行分析的结果表明：FG细胞失去接触抑制和生长的密主抑制，获得在细胞单层上聚集生长和堆积生长能力的同时，也获得了在软琼脂中生的能力(8－14个克隆/10~6个接种细胞)；RAPD分析表明，转化前后FG细胞的RAPD指纹发生了明显的变异。因此，FG细胞的自发性肿瘤转化也如哺乳动物细胞一样，包括一系列不断进行的细胞学和遗传学变化，并最终导致其基因组DNA的遗传变异。最后，本文分析了聚乙烯亚胺(PEI)和氯化镍在RSBF细胞中的细胞毒性和基因毒性，结果表明：鱼类细胞系RSBF可作为一个有效的检测水环境中污染的细胞毒性和基因性效应的效应的筛选系统；RAPD分析可作为一个灵敏的非专一性的基因毒性检测终点；PEI对RSBF细胞的高细胞毒性和基因毒性表明，我们在利用PEI作基因载体进行人类基因冶疗和进行鱼类转基因实验时要格外慎重；镍及其化合物可能是导致鱼类肿瘤性疾病的原因之一。

Size hierarchies affecting the social interactions and growth of juvenile Japanese flounder, Paralichthys olivaceus

Japanese flounder Paralichthys olivaceus (T. & S.)juveniles were size-graded and divided into three groups (small, large, and mixture of small and large flounder), and their social interactions (feeding, aggressive attacking and activity) and growth were investigated. The growth of the small flounder was markedly suppressed by the presence of the large flounder. Large flounder did not significantly suppress the overall food intake of the small flounder but exhibited high aggressive attacking on them and consequently inhibited their activity. Size dominance showed little influence on the aggressive behavior, feeding, activity and growth of the large flounder. The large flounder could not effectively defend the food in excess during the experiments ruling out disproportional food acquisition as the primary mechanism responsible for the size hierarchy effect. Aggressive interaction of the large flounder on the small flounder might be an important cause for the growth retardation of the small flounder. In culture, size grading could markedly improve the growth and survival of the early juvenile flounder. (C) 2004 Elsevier B.V. All rights reserved.