It was the first time a country had taken action on that, so these are very positive public health changes.

这是第一次国家政府对此采取措施,这都是些对大众健康很有益的改变

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选

That's a very positive change in the food environment, so we'll talk about those sort of changes.

这是食品环境的一项积极改变,我们将会谈到这一类的改变

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选

Now, what happens during an action potential is that that membrane potential changes very rapidly and it changes from being negative to being more positive.

在动作电位产生时,膜电位迅速改变,从较负的电位向更正的电位改变

耶鲁公开课 - 生物医学工程探索课程节选