The World Health Organization keeps track of what countries have cases of polio and when they occur, and what the frequency of--So, this is a map from a few years ago and there are efforts that occur occasionally.

世界卫生组织一直跟踪记录,发生小儿麻痹症的国家及发病时间,以及发生的频率,那么,这是从几年前开始统计的,一个地图,这里是一些偶然产生的成就

耶鲁公开课 - 生物医学工程探索课程节选

As I mentioned before is one example on the risk for breast cancer in women, so you'd randomly assign half to following their usual diet, the other half to an intervention program where people are prescribed a low fact diet, given counseling and interventions from dieticians and things, and then you look to see what happens for risk as people go forward in time.

我之前提过,这例子研究的是,女性的乳腺癌发病率,你将随机选择其中一半人按一般习惯饮食,另一半人则参与一个干预计划,其中每人都要食用,由营养学家设计推荐的低脂肪菜单,然后再看随着时间推移,被试者的发病率是怎样变化的

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选