Ocean freight transportation activities came to a halt late yesterday in several U.S. Gulf coast ports as Tropical Storm Isaac bears down on the Louisiana coast, taking aim at New Orleans seven years after Hurricane Katrina ravaged the city. Forecasters said Isaac could gain strength during the day and become a hurricane, with New Orleans expected to receive up to a foot of rain. The Port of New Orleans stopped all operations at 5 p.m. Monday. No vessels are allow...