Prenatal screening for chromosome abnormalities using maternal serum chorionic gonadotrophin,alpha-fetoprotein,and age

Human chorionic gonadotrophin (hCG) levels were assayed retrospectively in stored maternal serum samples from 78 chromosomally abnormal pregnancies and 410 controls matched for gestation and maternal age. The median serum hCG concentration in 49 pregnancies with Down's syndrome was significantly elevated, at 2.18 multiples of the normal median. Significantly reduced hCG concentrations were found in a group of four trisomy 18 pregnancies (all less than 0.4 multiples of the median). Eight cases of unbalanced chromosome rearrangements appeared to show some lowering of hCG levels, while there was no significant difference in the levels in the cases of trisomy 13, balanced translocations, and sex chromosome abnormalities. Maternal serum hCG alone is a better indicator of Down's syndrome pregnancies than maternal age or maternal serum alpha-fetoprotein (AFP), either individually or in combination, and provides a further virtually independent measure of risk. On the basis of our findings, screening for Down's syndrome using hCG and AFP results combined with maternal age risks is predicted to result in a higher detection rate (57 per cent) for a lower false-positive rate (5.0 per cent) than would be attainable by combined AFP and age screening (37 per cent detection at a 6.6 per cent false-positive rate).     

水体中重金属对人体健康影响的研究现状及对策

介绍水体中重金属对人体健康影响的研究现状，并提出了饮用水安全环境对策。     

人类活动对黄土高原生态环境及现代气候变化的影响

本文简要阐明人类活动对黄土高原生态环境和现代气候变化的影响。重点分析了黄土高原69个气象台站40年来(1951-1969年)气温、降水变化趋势。结果表明:黄土高原的平均气温从50年代以来不断升高,降水持续减少。升温幅度较大的地区多在干旱区的新兴大、中工业城市。并找出了人口增减对气温影响的关系。     

Reputation is valuable within and outside one’s own social group

To find conditions under which humans cooperate within groups of unrelated individuals has been of major interest in the behavioral sciences. The experimental paradigm for studying potential cooperation in social dilemmas is the public goods game. Here humans regularly fail to sustain a public resource cooperatively. However, the need to maintain good reputation for other social interactions, such as indirect reciprocity, has been identified as an effective mechanism to sustain cooperation in public goods situations. As a side effect of building a good reputation through cooperative actions, an individual provides direct benefits to members of his/her own social group. These benefits could be an incentive to reward a good reputation of group members. Here we show experimentally that building a good reputation through cooperative behavior in a public goods situation is rewarded in future social interactions, not only within ones own social group but also, at a similar level, in other social groups: humans regard cooperative behavior of others as an honest signal irrespective of past direct personal benefits. Reputation gained within as well as outside ones own social group can be a driving force for selfish individuals to cooperate in public goods situations, and thereby sustain any public resource.Communicated by T. Czeschlik     

Racial differences in maternal serum human chorionic gonadotropin and unconjugated oestriol levels

We assayed maternal serum samples from 134 black and 268 white women from 16 to 18 weeks of gestation for intact human chorionic gonadotropin (hCG), and unconjugated oestriol (uE3). Serum from women with high ( ⩾ 2·5 MOMs) or low (risk for Down syndrome ⩾ 1/365) maternal serum alpha-fetoprotein (MSAFP) levels were excluded. After correcting for maternal weight, we found that median hCG levels were 16 per cent higher in black women but uE3 levels were not significantly different. These results confirm three other studies for hCG and one study for uE3. Corrections are recommended for both maternal serum hCG and AFP before calculating the risk for Down syndrome in black women.     

地球物理环境与人类健康

阐述了地球物理环境的概念，以及原生物环境和次生物环境与人类健康之间的相互关系。文章指出，地球物理环境的存在及发展变化与人类的健康生存有密切的关系：由于现代生产活动所导致的的地球物理环境污染，破坏，已构成对人类健康的严重影响。文章呼吁，要加强对地球物理环境的保护，重视并开展这方面的有关研究，制订地球物理环境质量标准，切实保护好地球物理环境。     

人员可靠性与系统安全

论述了人员可靠性对系统安全的影响，分析了它的特点和应采用的研究方法，介绍了笔者近年来在核电站人员可靠性基础研究方面的情况，并对研究的发展趋势进行了展望。     

安全文化与企业文明施工的探讨

安全文化与企业文明施工是企业在生产经营中形成的思想观念体系，是企业职工整体的、综合素质的外化显现。施工现场能否文明施工，取决于人的行为、物的状态、环境的条件。安全文化是以人的管理为主体，以企业精神文明为核心，以职工群体的行为为基础。运用现代管理方法，把对人的管理与物的管理有机地结合起来，形成良好的经营运行机制，实现管理功能的整体优化。     

人体力学应用问题

较系统地阐述了人体力学的内涵、生理基础，各种力学作业（搬运、负重）的力学特征．改善力学负荷，提高工效的成就。还具体阐述了人体力学对于提高人类从事体力作业的工效的作用与意义，对其推广应用将会起到积极作用。     

论灾害防治指导思想的转变

在与灾害进行斗争的长期过程中，人类逐步形成了关于灾害防治的指导思想，其中既有正确的、科学的成分．也有错误的、不合理的成分。本文依据灾害本身的性质与规律，从灾害与自然生态──社会经济系统的相互关系原理出发，分析并重新认识当代社会人类进行灾害防治工作的指导思想．以图确立正确的灾害防治指导思想．为减灾防灾工作顺利而有效的展开奠定基础。