How do concentration and knowledge interact?

Concentration gives +x% XP, Knowledge gives +x seconds worth of XP

Will a spell with concentration get bonus XP from a knowledge rune?

Also, is concentration wasted on any slot other than the first?

That is, if I get 100xp per second, the second slot normally gets 50, so if I use a +50% rune, will it only get 75/sec, while slot one would get 150/sec? (i.e., 25 bonus XP instead of 50)

Thanks!