President Barack Obama urged this year’s graduates at Rutgers University to pursue positive change in the world despite a cascade of challenges from student loan debt to overseas turmoil. Obama’s visit to the New Jersey campus on Sunday fell on the 250th anniversary of the public university. University leaders had been lobbying the president to deliver a commencement speech for years, even turning to the state’s members of Congress to dial up the pressure. The White House has praised Rutgers as a “remarkable institution of higher learning.” White House spokesman Josh Earnest said Obama offered advice about how to approach the rapidly changing world.