DES MOINES, Iowa (AP) — Northern Iowa coach Ben Jacobson sees three physical areas his team must improve on this season. But Jacobson knows that chemistry will likely determine if the Panthers return to the NCAA tournament after a two-year absence. Northern Iowa returns most of the players who helped it reach the 20-win plateau for the fourth year in a row in 2011-12. Jacobson believes the Panthers need to rebound and defend better and improve their conditioning this season. He said Tuesday during the team’s annual media day that intangibles such as leadership and chemistry will be even more important.