Sen. Charles Schumer on Wednesday called on the federal departments of transportation and energy to enact stricter requirements to reduce the volatility of Bakken crude oil before shipment by rail.The current standard governing the vapor pressure of crude oil was insufficient to prevent fires and explosions, Schumer said in a conference call with reporters.Oil trains hauling 100 or more tanker cars, each holding about 30,000 gallons, regularly pass through the Hudson Valley.