LAWRENC, Kan. — Early in the first half against Oklahoma State, Kansas coach Bill Self stood up and looked directly at freshman guard Elmarko Jackson. The freshman, starting in the place of KU star Kevin McCullar, was playing aggressively but a little out of control. Naturally, Self mouthed to him to calm down. And he did, en route to one of his best games in a Kansas uniform … and a big KU victory. No. 8 Kansas blew out Oklahoma State 83-54 on Tuesday at Allen Fieldhouse. The Jayhawks led by as many as 31 on Tuesday. KU went into the half with a 44-26 lead and didn’t look back. Hunter Dicki…