Joao Lourenco has been sworn in as president of Angola, becoming the first new leader in the oil-rich southern African nation in almost four decades. <br/><br/>Lourenco, 63, took over on Tuesday from Jose Eduardo dos Santos, who ruled the former Portuguese colony for 38 years. <br/><br/>The Portuguese news agency Lusa reports that Lourenco's party – the People's Movement for the Liberation of Angola – won 61 percent of the vote in August. <br/><br/>Lourenco will be Angola's first head of state to be constitutionally limited to serving two five-year terms.'