Before revision:  From previous results, we may speculate about the fact that chemotactic cells , in many cases, can avoid obstacles by simply following the altered chemical gradient : social interactions seem to be sufficient to guarantee the aggregation of the whole colony past numerous obstacles .
After revision:  From previous results, we may speculate about the fact that chemotactic cells , in many cases, can avoid obstacles by simply following the altered chemical gradient . Social interactions are sufficient to guarantee the aggregation of the whole colony past numerous obstacles .