San Francisco supervisors are pressuring Mayor Ed Lee to fill in a federal funding gap for HIV/AIDS care in the city.  The city is losing about $8 million in federal funds for preventing HIV and treating low-income HIV patients.  Supervisor Scott Wiener says the cuts will limit access to care, and that's a serious long-term problem.  "If we don't have effective prevention programs." said Weiner,  "we will see an increase in infections, and it will be much more expensive for us in the long run."  Mayor Lee is scheduled to present his budget by June 1. The city is facing a $170 million budget deficit.