A report on multinational companies that are rushing to develop and import liquefied natural gas, LNG, a resource that is cheap to transport but many countries fear could pose risks to large population centers that lie near storage facilities.

A 35-year-old technology -- light emitting diodes or LEDs -- is getting a new life these days as a potential breakthrough for an even older technology -- the light bulb. Spencer Michels of the Science Unit provides a report.

A science unit report looks at the environmental cleanup in New Orleans after Hurricane Katrina inundated the city with filthy floodwater. Federal and state officials are at odds with environmental groups over the danger posed by toxins found in and…