These automatic weapons which fire lots of bullets with a singletrigger pull are illegal for any civilians to own unless they have acquired a very special Class III permit.
Dr Gabriele Nagel, one of the authors, said this may be because asthma is a collection of symptoms rather than a single condition, and different things may trigger it in different parts of the world.
There were fears that the country's possible exit from the euro would trigger a loss of confidence across the single currency bloc, and prompt investors to withdraw from other troubled economies, such as Greece.
Its disclosure that investigators working for the News of the World had intercepted and erased voicemails intended for murdered 13-year-old Milly Dowler was perhaps the single most incendiary detail in the entire scandal and helped trigger the wave of inquiries and resignations that followed.