In Arakune's story, before he fights Taokaka, theres a scene where Arakune (Human Form) was talking to Kokonoe about the Ars Magus. Litchi comes in and says "Oh, Professor Lotte, I didn't know you were here." then Arakune says "Yeah, I was asking Professor Kokonoe some questions about the research" and then it ends there.
I'll post exact dialogue later if no one ninja's me.
Edit: Yar, Arakune was talking to Kokonoe about using sither to nullify ars magus, but she kept telling him to stfu
Kokonoe: Haven't we been over this? It won't work.
Arakune:I must strongly disagree, I know what the accepted view of seithr is, but in reality it can be accepted as a particle-type phenomenon. So if we use it ars magus can be-
Kokonoe: Nullified right?
Arakune: Yes, that is correct.
Kokonoe: Ridiculous
-skip-
Kokonoe: Shut it.
Arakune: My apologizes but during those experiments....ugh... (Surffering from effects of the boundary)
Kokonoe: Hey are you all right?
Arakune: It was nothing, I just felt a little dizzy all of the sudden.
Kokonoe: How about you take a breather, you barely slept since you came back from Ikaruga
Litchi: Professor are you there?
Kokonoe: Anyway this conversation is over, Yes come on in.
Litchi: I wanted to inform you of the results of the experiments are in today, Oh Lotts, I didn't know you were here.
Arakune: Yes, I just had a few questions about our current research, Well I should be going.