When North Carolina hosts rival Duke on Wednesday night, the Tar Heels will find themselves in a position few could have imagined to start the season.The defending national champions enter February unranked and sitting near the bottom of the Atlantic Coast Conference standings. North Carolina (13-10, 2-6 ACC) has lost seven of nine games since the start of 2010, including three straight. They are coming off a 21-point loss at Maryland that ranks as the most lopsided loss under Roy Williams.