Differential sensitivity of flounder (Platichthys flesus) in response to oestrogenic chemical exposure: an issue for design and interpretation of monitoring and research programmes

This study was conducted as an initial investigation of 'differential response' in one of the main sentinel organisms used for monitoring programmes in United Kingdom estuaries, the flounder Platichthys flesus. It has been hypothesised that monitoring using species with a wide geographical spread and limited migration, such as flounder, might result in the comparison of different genetic stocks and certainly of populations with differing early life stage contaminant exposure histories. Furthermore, it is probable that these pre-exposure and genetic differences could manifest themselves in an ability to respond differently to contaminant exposure, so-called 'differential response'. It is important that the extent and nature of this response is understood, if we want to be able to fully interpret the monitoring data from such programmes. During this study, flounder were collected from four separate sources; wild caught fish from the estuaries of the Rivers Alde, Mersey and Tyne, and farmed flounder from Port Erin Farm, Isle of Man. Under controlled laboratory conditions, groups of fish from each source were exposed to water-borne concentrations of the synthetic oestrogen ethynylestradiol (EE2) at a nominal concentration of 50 ng/l. Plasma was taken from each male fish after 6 and 10 days exposure and analysed for the presence of vitellogenin (VTG) using an ELISA technique. Significant levels of VTG induction were evident in fish from all sources after both 6 and 10 days exposure. Flounder from the Mersey were the only fish with significantly elevated initial background levels of VTG (day 0) and this appeared to be reflected in that these specimens showed the highest induction response after day 6. However, after day 10, fish from all other sites had a slightly higher mean VTG than those from the Mersey which showed significantly (p < 0.05) lower mean plasma VTG. It is suggested that other differential responses may have been masked by the use of a high dose of EE2 which produced maximum induction in nearly all fish. The findings of the study are discussed in terms of implications for further research into the differential response issue and how the initial plasma VTG figures contribute to a time-series from the Mersey, Tyne and Alde estuaries.     

Patterns of literacy in the People's Republic of China

The recent publication of data from the 1982 census permits an assessment of the patterns, progress and problems of illiteracy in China. Educational progress, since the communists came to power in 1949, has been particularly impressive, especially in relation to the low levels of income within the People's Republic. Nevertheless, nearly a third of the country's population are still unable to read and write and major variations in literacy exist between the developed and less developed regions, between men and women, between the urban and rural areas, between the various age groups and among the many ethnic groups that constitute the People's Republic of China. Among the most favoured people and places, literacy rates exceed 90% but among the most disadvantaged groups, retired women in rural areas for example, levels of literacy fall below 3%. Proposed educational reforms, targeted to provide nine years of compulsory education, offer the potential for boosting literacy levels and breaking the bondage of ignorance. However, such proposals are being undermined by the recent economic reforms in rural China. By stressing the value of labour, including child labour, the agricultural responsibility system has generated a surprising decline in school attendance which may jeopardise future improvements in literacy, particularly so among the poorer people in the poorer areas of China.     

澳大利亚维多利亚州肭屏半岛第四纪古土壤沉积物的初步研究

本文对澳大利亚维多利亚州肭屏（Ｎｅｐｅａｎ）半岛海岸悬崖风成岩古土壤序列沉积学地层的成土母质来源、成土时期的环境、时代等问题进行研究。     

蛇绿岩杂岩中碳酸盐化超镁铁岩的金矿化

在阿尔卑斯型超镁铁岩体边缘,分布有含碳酸盐超镁铁岩,即V·Lobochnikov等称的滑石菱镁片岩(Iistwaerite),其中可以见到汞、砷、钻—镍砷化物等各种矿化。此外,还已知产有一些金矿,但金与滑石菱镁片岩及超镁铁质围岩的成因关系仍存在疑问。为此,我们对上元古界(摩洛哥、沙特阿拉伯)和阿尔卑斯(利古里亚)蛇绿岩杂岩的含金滑石菱镁片岩进行了研究。 滑石菱镁片岩中金的分布是随机的,在上述三研究区,大多数样品的金含量相似,即0.02—1ppm,为伴生的超镁铁岩含金量(5—100ppb)之10—100倍。看来,滑石菱镁片岩是含金很富的一种岩类。滑石菱镁片岩的最高含金量为1—10ppm(达边界品位),与富黄铁矿带有关,尤其与砷化钴矿化有关(如摩洛哥的布阿泽尔地区),也与含副矿物黄铁矿或毒砂的晚期石英脉(含金0.2—10ppm)有关。实际上,从单矿物分析表明,滑石菱镁片岩中的主要含金矿物是黄铁矿(含金10—50ppm)和砷化钴(含金10—100ppm)。在上述矿物中     

用套钻应力解除法和声发射凯塞效应法测定花岗岩中的原位应力

坎伯恩矿业学院等关于干热岩体地热能源项目的研究经验清楚地表明：干热岩体热交换的开发在很大程度上取决于天然裂隙网络与原位应力状态的相互影响。