Wormlike chain or tense string? A question of resolution

It is shown that a wormlike chain, i.e., a filament with a fixed contour-length S and a bending elasticity kappa, attached to a frame of length L, can be described--at low resolutions--by the same type of elastic free-energy as a tense string. The corresponding tension is calculated as a function of temperature, L, kappa and S.