"There was a lower concentration of dopamine markers in the brain of individuals with A.D.H.D., specifically in the areas of the brain that are involved with reward and motivation."

VOA: special.2009.09.29

It doesn't tell you, this is the equilibrium concentration that you'll end up with.

他无法告诉你,最终平衡时的浓度是多少。

麻省理工公开课 - 热力学与动力学课程节选

And that was when I switched my concentration from computer science to philosophy and psychology with a single question: ? how can I become happier?

于是我将研究方向,从计算机科学转向了哲学及心理系,目标只有一个：,如何变得更快乐？

哈佛公开课 - 幸福课课程节选

"The Nobel Prize in literature for 2009 is awarded to the German author Herta Mueller, who with the concentration of poetry and the frankness of prose depicts the landscape of the dispossessed,"

VOA: standard.2009.10.08