Notice of Designation of a Longer Period for Commission Action on Proceedings To Determine Whether To Approve or Disapprove a Proposed Rule Change, as Modified by Amendments No. 1 and 2 Thereto, Relating to Amendments to NYSE MKT Rules 1600 et seq. and the Listing Rules Applicable to the Shares of the Nuveen Diversified Commodity Fund and the Nuveen Long/Short Commodity Total Return Fund