They think the second spike is due to the 1986 Chernobyl disaster in which the reactor exploded in the Ukraine(乌克兰).
The effects of Chernobyl were felt locally and no effect was seen in the U.S., probably because it was too far from the disaster to have an effect.
“The closer the country was to Chernobyl, the stronger the effect,” said study coauthor Hagen Scherb, a biostatistician(生物统计学家) at the German Research Center for Environmental Health in Munich.
More males were born relative to females in Belarus—the Ukraine's neighbour—than in France.
The study is based largely on Cold Warera statistics, but the findings are highly relevant for how gender could be affected after future nuclear disasters.
And in the wake of Japan's Fukushima Daiichi nuclear power plant accident experts are predicting another baby boy boom could come, especially on the U.S. West Coast.
Previous radiation experiments on animals may give a clue for the increase in male births. Tests showed that radiation caused damage to the X chromosome(染色体) in sperm, Dr Scherb said.
A human sperm cell contains either an X or Y chromosome, while an egg only has an X chromosome. An XY combination will become a boy, while an XX combination will be a girl.
36.How many nuclear radiation accidents are mentioned in the passage?
【2017届高考英语一轮复习课时作业4:Unit 4《Earthquakes》(新人教版必修1福建专用)】相关文章:
★ 【北京专用】2014届高考英语一轮复习方案课时作业:选修7 Unit 3 Under the sea
★ 2014届高考英语一轮复习课时作业(七)必修2Module 1《Our Body and Healthy Habits》(外研版)
★ 四川省2016届高考英语一轮复习课时作业(23) Module 5 A Trip Along the Three Gorges 外研版必修4
★ 四川省2016届高考英语一轮复习课时作业(35) Module 5 Cloning 外研版选修6
★ 2014届高考英语一轮复习课时作业(二十三)必修4Module 5《A Trip Along the Three Gorges》(外研版)
★ 2017年高考英语二轮复习精品资料:专题15 完形填空(教学案)(原卷版)
★ 【北京专用】2014届高考英语一轮复习方案课时作业:选修8 Unit 4 Pygmalion
★ 【北师大版】2014届高考英语一轮复习指导课时作业:Unit 9 A卷 Word版含解析
最新
2017-04-24
2017-04-24
2017-04-24
2017-04-24
2017-04-21
2017-04-21