Spinola was duly installed as president after the coup and then provoked into resigning five months later in protest against too rapid a withdrawal from Africa, where Portugal's colonial involvement dated back to 1415.

ECONOMIST: Melo Antunes | The

"I've never known him to be violent at all unless he was provoked, and then he would turn the other cheek, " Robert Zimmerman testified.

CNN: Zimmerman apologizes as judge sets $150,000 bond

His father, Robert, said he did not know his son to be violent unless provoked, and even then he was likely to "turn the other cheek".

BBC: Florida judge sets George Zimmerman bail at $150,000

But the shift towards synthetic fuel has provoked criticism, because when such fuel is made from coal and then burned in an aircraft engine, more greenhouse gases are emitted overall than would be produced if the aircraft simply burned conventional fuel derived from oil.

ECONOMIST: Monitor