A survey of diagnostic amniocenteses in Oxford from 1974–1981

A survey was conducted of the results of mid-trimester diagnostic amniocenteses in the Oxford Region from 1974 to 1981. The survey used data relating to all 4357 singleton pregnancies in which an amniocentesis was performed during this period. Follow-up information on outcome was obtained in respect of 4284 (98 per cent) pregnancies. A cell culture to determine karyotype and an alpha-fetoprotein determination was carried out in all cases. From 1974 to 1981 amniocenteses became increasingly common, rising from 2 to 32 per 1000 births. The most common indication for amniocentesis was a high risk of a chromosome abnormality–56 per cent of all amniocenteses. Within this group advanced maternal age was responsible for 89 per cent of the cases. The next most common indication was a high risk of a neural tube defect (37 per cent of all amniocenteses)–in 1974 a raised maternal serum alpha-fetoprotein level accounted for only 4 per cent of these; by 1981 this had risen to 67 per cent. There were seven false-positive and 132 true-positive diagnoses of neural tube defect; since 1981, with the introduction of amniotic fluid acetylocholinesterase determination as a secondary diagnostic test for neural tube defects, there have been no further false-positive diagnoses. In 1981 76 per cent of women aged 35 years or more did not have an amniocentesis. It is not known to what extent this was due to not offering women in this age group amniocentesis or to women not accepting such an offer.     

上海市水资源利用现状及预测

水资源在上海的社会、经济、环境的可持续发展中具有十分重要的作用。文章在准确认清上海市水资源现状基础上。综合了当前水资源的利用状况。并采用数学模型，对上海市2004～2020年工业用水和生活用水加以预测分析;最后,就上海市水资源利用存在的瓶颈问题进行了分析，提出了相应的解决对策。     

用规划方法安排干旱和半干旱地区的农田灌溉方案——以河北省曲周县冬小麦为例

为提高干旱和半干旱地区的水分利用率,本文提出用规划方法安排农田灌溉方案,并以河北省曲周县冬小麦为例说明有关问题的处理方法。用规划方法求出的灌溉方案增产效果是显著的,比目前生产上采用的“保灌水浇地”的传统灌溉方法增产18％左右。     

玉米淀粉生产废水综合利用的效益分析

生产玉米淀粉过程中排放大量高浓度有机废水、将其进行综合利用，可以提取蛋白粉、玉米浆等多种物质，这里以年产１万ｔ玉米淀粉为例，具体分析了玉米淀粉生产废水综合利用的经济效益与环境效益．表明：玉米淀粉生产废水综合利用前景广阔，是解决该部分废水污染，实现经济效益与环境效益相统一的重要途径．     

油田行业"三废"综合利用研究

介绍了国家“三废”综合利用方面的政策，结合油田行业资源综合利用现状，提出如何进一步开展油田行业“三废”综合利用工作，并更好地利用国家资源利用税收方面的优惠政策，开拓油田行业“三废”综合利用渠道，推动“三废”综合利用，争取得到最大限度的减免税额。     

浅谈粉煤灰综合治理及建议

介绍了大庆石油化工总厂热电厂自投产以来，粉煤灰综合治理的经过，所采取的措施，存在的问题和收到的成效。这对于我国高寒平原地区的燃煤电厂有一定的借鉴参考作用。     

关于植物化学生态信息的开发与利用

植物的化学信息，早已被人们所关注和利用，目前，该研究已成为生态学和化学生态学中最活跃，最能为社会与生产服务的领域之一，生态系统中的物质流和能量流是资源，而生态学的信息则是更具开发，利用前景的资源。     

玻璃生产企业废水综合利用的可行性探讨

本文分析了玻璃生产企业废水的来源,并从耀华玻璃集团实施的废水治理项目的实际出发,阐述了废水经过治理后综合利用的途径,实现废水的零排放,减少环境污染,节约水资源。     

减缓贫水化过程的途径再议

根据贫水化的严重形势，应用水循环的原理，提出了减缓贫水化的几个主要途径，对解决城市淡水短缺有参考意义。     

Improving Operational Planning and Management of National Parks in Turkey: A Case Study

The purpose this study was to improve operational planning and management of national parks in Turkey to balance conservation use and sustainable management. Souksu National Park (SNP) was chosen as the study area. The data were obtained from interviews of 182 visitor groups (in total, 819 people) and analyzed using correlation, factor, discriminant, and regression analyses. It was found that the most important factors affecting operational planning and management of SNP are (1) travel cost, (2) visitor welfare level, (3) intensity of use, (4) size of visitor group, (5) type of recreational demand. The main source of visitors to SNP is from a zone within a 0–90-km radius. This region comprised 53.85% of total visitors to the park. The capital of Turkey (Ankara) is the most important source of visitors from within this zone. The optimum activity mix in SNP is also determined. Picnicking, viewing the scenery, and nature walks or trekking comprised the main uses of the park. It is anticipated that these findings will help to improve operational planning and sustainable management of the national park and the environment.