SAN FRANCISCO (AP) — San Francisco Mayor Ed Lee on Monday touted the city's plans to revitalize the long-neglected Mid-Market neighborhood by luring tech companies like Twitter, which is set to go public this week. Lee took journalists on a walking tour Monday of a stretch of Market Street that is being transformed by an influx of tech firms and workers. The mayor says the arrival of Twitter and other tech firms illustrates the success of the city's efforts to draw companies to the Mid-Market neighborhood, long known for its crime and seedy theaters and as a place frequented by the homeless.