Alar and apples: newspapers, risk and media responsibility

During 1989, a major environmental and health risk issue, the spraying of Alar on apples, created a furor among the American people. After hearing charges from the Natural Resources Defense Council (NRDC) that eating Alar-laden apples significantly increased a child's risk of developing cancer, numbers of school districts dropped apples from their menus and parents poured apple juice down the drains. Apple sales plummeted. The NRDC's charges, which were disseminated by a well-planned and effective public relations campaign, brought counter-charges from the US environmental Protection Agency, which accused the NRDC of basing its study on poor data, among other things. The core of the dispute was in the risk figures and risk interpretations being used by each organization.     

烧钱的太空

虽然美国航空航天局（NASA）的预算在过去两年中增加了7％，但它的责任却以更快的速度在加码。首先，它必须重新启动航天飞机的飞行，而且确保安全（自2003年哥伦比亚号失事以后，航天飞机的飞行就中止了）。其次，它计划继续组装国际空间站，这座部分完工的轨道据点目前有两名宇航员长驻，并由俄罗斯飞船运送补给品。第三，布什总统去年命令它研制“载人探索飞船”（Crew Exploration Vehicle，CEV），设计这种新型飞行器，旨在把宇航员重新送上月球，并最终实现人类登陆火星。     

古老脚印之谜

大约360万年以前，在现今坦桑尼亚的莱托里（Laetoli），一串脚印留在了一层新沉积的火山灰上。这些脚印现在成了最引人遐想的人类祖先遗迹之一。1978年，MaryLeakey率领的一支考古队发掘出了莱托里脚印，根据这些脚印，考古学家得出了一个令人瞠目的结论：人类早在制作石器并进化出大容量的脑之前就已经开始直立行走了。这些脚印也引发了不少争议：科学家们对脚印所涉及的每一个问题——从它们是多少人踩出来的到保护它们的最佳措施——都争论不休。不过大家普遍认同下面的看法，即这些脚印多半是阿法南猿（Aus—tralopithecus afarensis）留下来的（阿法南猿最著名的代表是Lucy化石）。而现在由于新的研究成果的问世，连这一点共识是否站得住脚都成了问题。     

The effects of American Sign Language as an assessment accommodation for students who are deaf or hard of hearing

Students who are deaf or hard of hearing (SDHH) often need accommodations to participate in large-scale standardized assessments. One way to bridge the gap between the language of the test (English) and a student's linguistic background (often including American Sign Language [ASL]) is to present test items in ASL. The specific aim of this project was to measure the effects of an ASL accommodation on standardized test scores for SDHH in reading and mathematics. A total of 64 fifth- to eighth-grade (ages 10-15) SDHH from schools for the deaf in the United States participated in this study. There were no overall differences in the mean percent of items students scored correctly in the standard vs. ASL-accommodated conditions for reading or mathematics. We then conducted hierarchical linear regression analyses to analyze whether measures of exposure to ASL (home and classroom) and student proficiency in the subject area predicted student performance in ASL-accommodated assessments. The models explained up to half of the variance in the scores, with subject area proficiency (mathematics or reading) as the strongest predictor. ASL exposure was not significant with the exception of ASL classroom instruction as a predictor of mathematics scores.     

事情搞糟了

由于发现一位生物化学家在两份公开发表的论文中捏造了实验结果，关于低强度电磁场可能有何种影响的研究受到了极大的打击。美国卫生部研究道德办公室公布的一份分析报告草案认为，一直在劳伦斯伯克利国家实验室工作、1999年才被迫退休的生物化学家Rober P．Liburdy“有意伪造数据”以证明低强度电磁场对培养细胞有影响。     

树枝状聚合物分子

化学家们现在能够建造分形超级分子。这类新的聚合物（称为树枝状聚合物）有希望在生物技术和环境保护中显示出重大价值。     

武检专家看伊拉克

在巴格达大学的萨达姆生物技术中心一座堪称现代化的研究设施中，从国外秘密进口的设备比比皆是，有的用于大量复制DNA片段，有的用于凝胶测试以确定蛋白质分子的大小。Rocco Casagrande回忆说：“看起来，你仿佛是来到了美国一个设备精良的研究所的实验室里。”身为联合国核查人员的Casagrande于2000年12月中旬开始赴伊拉克的各个有关设施进行检查。     

费马定理卷土重来

费马定理卷土重来郭凯声，郭敏物理学家兼诗人皮特·海因说过：“值得人们研究的问题常常会反扑过来从而证明其价值。”费马最后定理正好就是这种情况。它在去年夏天看来已被击倒之后却又从拳击垫上跳起来以进行新一轮较量。这一表面上十分简单的定理是说，当指数Ｎ大于２...