Comment on “Radiocarbon calibration curve spanning 0 to 50,000 years BP based on paired Th-230/U-234/U-238 and C-14 dates on pristine corals” by R.G. Fairbanks et al. (Quaternary Science Reviews 24 (2005) 1781-1796) and “Extending the radiocarbon calibration beyond 26,000 years before present using fossil corals” by T.-C. Chin et al. (Quaternary Science Reviews 24 (2005) 1797-1808)