The DNA Mini-Circle Problem

 
On short length scales the DNA double `helix' is quite stiff and has a minimum energy, open, intrinsic shape (left figure). The ends of the `helix' are sticky and molecules sometimes catch their own tails to cyclize (centre). The molecule can cyclize with different links of the double helices. We model the DNA as an elastic rod and capture all possible links, by a continuation computation in the imposed angle alpha (right).
 
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