Question Mark (aircraft) Question Mark (aircraft) Question Mark (""?"") was a modified Atlantic-Fokker C-2A transport airplane of the United States Army Air Corps. In 1929, commanded by Major Carl A. Spaatz, it was flown for a flight endurance record as part of an experiment with aerial refueling. "Question Mark" established new world records in aviation for sustained flight (heavier-than-air), refueled flight, sustained flight (lighter-than-air), and distance between January 1 and January 7, 1929, in a non-stop flight of more than 150 hours near Los Angeles, California. Following the record-setting demonstration, the C-2A was returned to transport duties. In 1931 more powerful engines replaced
Non-stop decay Non-stop decay Non-stop decay is a cellular mechanism of mRNA surveillance to detect mRNA molecules lacking a stop codon and prevent these mRNAs from translation. The non-stop decay pathway releases ribosomes that have reached the far 3' end of an mRNA and guides the mRNA to the exosome complex, or to RNase R in bacteria for selective degradation. In contrast to NMD, polypeptides do not release from the ribosome, and thus, NSD seems to involve mRNA decay factors distinct from NMD. Non-stop decay is a cellular pathway that identifies and degrades aberrant mRNA transcripts that do not contain a proper