Monitoring chemical contamination levels in the Mediterranean based on the use of mussel caging

Within the framework of the biointegrator network (RINBIO), 92 man-made cages containing mussels (Mytilus galloprovincialis), distributed over 1800 km of the French Mediterranean coast, made it possible to assess chemical contamination by heavy metals (Cd, Hg, Zn, Pb, Cu, Ni, Cr, As) and organic compounds (DDT, PCBs, HAP). The caging technique was adopted to compensate for the scarcity of natural shellfish stocks in the Mediterranean and to enable comparison of the sites regardless of their physicochemical and trophic characteristics. Models linking a biometric parameter (the condition index) to pollutant levels make it possible to adjust raw data on contamination for a reference individual, by making a clear distinction between physiological factors (growth) and environmental ones. The results demonstrate significant levels of pollutants in sites heretofore unsampled; the pollution occurs at limited areas, and the sources have been identified. Moreover, average contamination levels are comparable to those measured in wild species and in other areas. Overall, the research demonstrates the reliability of this methodological approach for monitoring marine pollution, especially in the Mediterranean.     

运输在各工业部门合理布局中的作用

正确的、合理的工业布局问题,对于中国的大规模工业建设具有头等重要意义。在工企业的设计与建设过程中,如果在工艺及桔构中发生错误,还可以在将来的生产过程中纠正;如果在建设地址的选择上,亦即在工业企业的布局上发生错误,就不可能改正了,而     

利用振动活塞取样管研究近岸沉积层的方法

形成各种堆积体——砂滩、砂嘴、砂洲等的近岸沉积层结构的研究在海岸研究中占有特殊地位。在沉积层结构中,以及它的岩石学和动物区系方面反映着沉积层发展的历史。对于堆积体结构的研究,可以使我们追溯它发展时期的层序性,从而指出在特定的地理条件下的海岸演化的一般规律性。通过厚度的研究、层次相关性的对比、使用现代方法测定沉积层的绝对增长,我们就     

AUFFINDUNG VON REIS IN EINER TONSCHERBE AUS EINER ETWA FNFTAUSEND-JHRIGEN CHINESISCHEN SIEDLUNG.

Von Professor GUNNAR ANDERSSON aufgefordert, haben wir versucht, Pflanzenreste in einigen von ihm (1923) gemachten Funden aus neolithischen und aeneolithischen Siedlungen in China zu identifizieren. Unter diesem Material befand sich eine Tonscherbe, die mit der Marke Y. S. Ⅺ versehen     

平流层中之氦容量

平流层中所以缺乏有系统之温度坡度者,吾人常以该层空气缺少大量之混合所致。对流层中,风之流动,可使大气之成分,保住常态,及过对流层与平流层之界面,则风速骤减;越界面而上,空气之混合停止,其成分遂因高度而生变异。英格兰之上空,平流层与对流层之界面,在十一公里与十二公里间。至於平流层中空气在何处始停止大量之混合,吾人不得而知。Chapman及Milne以为空气停     

The phthalate diesters DEHP and DBP do not induce lauric acid hydroxylase activity in rainbow trout

Aquatic organisms are extensively exposed to phthalate esters. We have investigated in trout the effects of diethylhexylphthalate (DEHP) and dibutylphthalate (DBP) on xenobiotic metabolizing enzymes which have been suggested as possible environmental biomarkers. Rainbow trout (Oncorhynchus mykiss) were waterborne exposed to DEHP (1 mg/l) or DBP (0.1 or 1 mg/l) for 72 h. Another group of rainbow trout received daily for 3 days an intraperitoneal injection of 50 mg/kg of DEHP or DBP. Laurate hydroxylation, ethoxyresorufin-o-deethylation, UDP-glucuronyltransferase activity and glutathione-S-transferase activity were measured in liver and extrahepatic tissues. The phthalate esters have been found not to induce these enzymes; in particular, the results do not support the previously described induction of lauric acid hydroxylase in sea bass treated with DEHP [Comp. Biochem. Physiol. B122 (1999) 253.].     

付里叶形状分析方法及其在地质学中的应用

作为1种有效的定量分析方法。付里叶形状分析已被应用到地质学诸多分支学科的研究中，如沉积学、岩石学、微体古生物学等。文中简要介绍付里叶形状定量分析的基本原理和方法，特别是闭合式付里叶分析方法及其在地质学中的应用。应用实例之一是南极沉积物源的解释，即怎样区分冰期海洋沉积物和冰蓣物；之二是研究反映生态环境变化的浮游有孔虫G．truncatulionoides的形状。其付里叶形状定量分析结果与δ^18O同位素数据相吻合。     

Genetic responses to metal contamination in two clams: Ruditapes decussatus and Ruditapes philippinarum

Coastal ecosystems are subjected to a wide variety of disturbances, including those due to xenobiotics of agricultural and industrial origin. These pollutants as heavy metals can modify the genetic diversity of populations by favouring or counter-selecting certain alleles or genotypes by differential mortality. In the present study, two genetic markers (phosphoglucomutase and glucosephosphate isomerase) and a protein marker (metallothionein) were monitored in order to determine the impact of heavy metals in different clam populations. Analysis of the genetic structure of the clam populations examined reveals that those inhabiting environments contaminated by heavy metals exhibit a higher allelic diversity and possess alleles at PGM loci that could be selected by the presence of heavy metals. The evaluation of metallothionein levels using a specific polyclonal antibody developed in the Pacific oyster (Crassostrea gigas) demonstrated the existence of a relationship between metallothionein concentrations and the level of metal pollution for clam populations sampled from different sites. An inter-specific difference was also detected between Ruditapes decussatus and Ruditapes philippinarum living in sympatry at the same site, suggesting a differential response of these two species upon exposure to an identical heavy metal concentration.