Continuous positive airway pressure (CPAP) machines are used to maintain an open airway in patients diagnosed with obstructive sleep apnea. The machine functions by blowing pressurized air into the airway via mask at a setting determined by sleep study and prescribed by a physician.
Also the second largest impact structure on Earth, the 1.85 billion years old Sudbury crater in Canada, hosts world-class mineral deposits - in this case nickel-rich minerals that were melted and concentrated by the extreme heating caused by the impact.
Image caption The Tamu massif is comparable in size to Olympus Mons on Mars. Scientists say that they have discovered the single largest volcano in the world, a dead colossus deep beneath the Pacific waves. A team writing in the journal Nature Geoscience says the 310,000 sq km (119,000 sq mi) Tamu Massif is comparable in size to Mars' vast Olympus Mons volcano-the largest in the Solar System.