He completed his first triathlon in 2009, winning the "first-timer" division at the Flat as a Pancake race in Staten Island.
We show that even though a model with a simple timer triggering division is sufficient to maintain cell size homeostasis, such a model is not compatible with the data.
This lack of robustness argues against a timer mechanism for division control in E. coli as well as in other exponentially growing organisms.
We demonstrate that a size-independent timer mechanism for division control, though theoretically possible, is quantitatively incompatible with the data and extremely sensitive to slight variations in the growth law.
Embryonic cells, however, have their division timers set back to zero.
In contrast, this distribution cannot be generated by a timer model where the division rate depends solely on age.
It is thought that this cell division countdown timer developed as a tumour suppressing mechanism to prevent precancerous cells from proliferating indefinitely.
In conclusion, the mathematical arguments that were previously developed are insufficient to rule out a size-independent, timer model of bacterial division: quantitative comparisons between models and data are needed.
OPCs can differentiate into oligodendrocytes in the absence of axons (Abney et al., 1981), giving rise to the idea that OPCs contain an intrinsic timer related to cell division that regulates their development.
Long timers at the news division were unhappy over her initial proposals, which included adding a studio audience to the Washington discussion show "Meet the Press" and putting a dog on "Today". "Meet the Press" still has a closed set, but "Today" is already on its second dog.
This finding supports our notion that it can indeed be relevant to go beyond the division of part-timers and full-timers in two groups, by taking the actual time invested into account.
