The main goal of this work was to estimate the effectiveness of close encounters with large asteroids as a mechanism of semimajor axis mobility.     We were therefore interested in knowing what was the maximum drift in a and how many particles were actually moved more than 0.001 AU during the length of the simulation.    In the following figures we report histograms with changes in a at t=100, 300, 500 My for the simulations involving SWIFT-SKEEL.   We used a bin size of a = 0.0002 AU.
 
 

At the end of the integration (t=500 My) there were 5 particles in the Adeona run that drifted more than 0.005~AU, and none in the synthetic Adeona integration.   The average drift rate was of 4.9*10^-4 AU/100 My for both simulations, in agreement with what found by Nesvorny' et al. 2001.   Results for Gefion are reported in the following figures.
 
 

In this case, 16 particles drifted more than 0.005 AU at t=500 My for the integration with real members of Gefion, and 8 particles for the synthetic Gefion family.  The drift rates were 10^-3 AU/100 My and 9.5*10^-4 AU/100 My, i.e. more than twice the drift rate found by Nesvorny' et al. (2001) for their integrations of asteroids with a > 2.5 AU.   Results for the Dora integration are not yet available.