deletions | additions       diff --git a/Fucci validation.tex b/Fucci validation.tex  index b5de728..4097097 100644  --- a/Fucci validation.tex  +++ b/Fucci validation.tex 
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In order to validate the use of the nuclear area to infer the cell cycle phases we imaged NIH/3T3 fibroblasts containing the Fucci system, a two colors fluorescent reporter that allow to distinguish G1 phase from S/G2/M phase \cite{Sakaue-Sawano2008}. We modified our HMM to infer the cell cycle phase from the Fucci signal (denoted $\phi_F$) by multiplying the emission probabilities of both colors (Supplementary Figure \ref{fig:cellCycleFucci}, Section \ref{sec:HMM_methods}) and independently inferred the cell cycle phase from the nuclear area ,$\phi_N$. area, $\phi_N$.  When comparing the two phases we found a reasonable good  agreement, the synchronization index $R(\phi_N - \phi_F)$ being equal to $0.83$. The two methods are very accurate close to divisions (the abrupt change in the signal at division contains a lot of information) but expectedly,  show more variations in the middle of the cycle. To provide a more intuitive measure of the precision of our inferences we estimated the durations of G1 and S/G2/M from both phases, overall the S/G2/M (G1) durations inferred from the Fucci signal were predicted from nuclear area with an error of $\pm 2.0h$ ($2.3h$), compared to a mean duration of $14.4h$ ($10.3h$).