404. That’s an error.
The requested URL /bookmarks/mark?op=add&bkmk=http%3A//rsos.royalsocietypublishing.org/content/5/6/180139&title=Transition%20mechanism%20for%20a%20periodic%20bar-and-joint%20framework%20with%20limited%20degrees%20of%20freedom%20controlled%20by%20uniaxial%20load%20and%20internal%20stiffness
was not found on this server. That’s all we know.