Cranial suture closing in Homo sapiens: evidence for circaseptennian periodicity

Brief communication: age and fractal dimensions of human sagittal and coronal sutures

The fractal dimensions of human sagittal and coronal sutures were calculated on 31 complete skulls from the Terry Collection. The aim was to investigate whether the fractal dimension, relying on the whole sutural length, might yield a better description of age-related changes in sutural morphology, as opposed to other methods of quantification, which generally rely on more arbitrary scoring systems. However, the fractal dimension did not yield better age correlations than other previously described methods. At best, the results reflected the general observation that young adults below age 40 years display an age-related development, but that it is impossible to arrive at any precise age determinations for older adults. It seems that for some individuals, suture obliteration simply does not take place, even at an advanced age, whereas for others, suture obliteration progresses rapidly. Until a better understanding of sutural biology is reached, this will render cranial sutures only marginally useful in age determination. This does not mean, however, that investigations should not be made to elucidate more unbiased methods of sutural morphology quantification.

Periodic Berth-Year Pattern of the Founders of Statistical Sciences

The distribution of the birth-years of 19 founders of statistical sciences, as reported in a recent book on the history of statistics, shows a circaseptennian (approximately 7-year) periodicity. A second sample of 31 statistical pioneers, extracted from the Encyclopedia of Statistical Sciences, supports the first observation. Up to the end of the 19th century, founders of statistical sciences tended to be born in years belonging to the 7 n+2 phase. There are also indications for circaseptennian patterns connecting different statistical schools during the last century. These findings extend earlier reports of a circaseptennian pattern in the birth-year distribution of physicists.