Canwest News Service: A U.S.-based company that has controversially laid claim to nearly all of the Arctic Ocean’s undersea oil said Thursday that new geological data suggests a "potentially vast" petroleum resource of 400 billion barrels. That figure is backed by a respected Canadian researcher who recently signed on as the firm’s chief scientific adviser. Las Vegas-based Arctic Oil & Gas has raised eyebrows around the world with its roll-of-the-dice bid to lock up exclusive rights to …