HAVANA, September 17 —In less than 24 hours more than 1,000 intellectuals from Latin America, the United States, Europe and Africa have signed an appeal circulated by their Cuban colleagues, expressing solidarity and demanding an end to the U.S. blockade of Cuba. The message, which is circulating on the Internet, notes that Cuba was dramatically impacted by two powerful hurricanes recently, and that its people are demanding an immediate halt to the odious blockade that has been maintained against Cuba by successive U.S. administrations for almost 50 years. The appeal to the world from a large group of Cuban artists...