For example, what if I activated this cell

如果促使细胞产生这种特定的配体
by encouraging it to produce this particular ligand?

以此来激活细胞会出现什么结果
That ligand was one for which the cell had a receptor

对于带有对应受体的细胞来说
that further encouraged it to produce more of the ligand.

这种配体能够刺激细胞产生更多的配体
Well, then you could imagine a cycle here

那么你就能画出一个循环图
where activation of the receptor is leading to

激活受体能导致
production of more ligand,

更多配体的生成
is leading to activation of the receptor and production of a ligand.

这些配体又会刺激受体生成更多配体
That's an example of a process called positive feedback.

这个过程叫做正反馈
The more the receptor gets activated

受体被激活的程度越高
the more feedback it gets to activate.

产生的反馈效应就越强
That can be a very strong amplifying response,

这可能会产生非常强的放大效应