Before revision:  We find that the error in J arising from the harmonic approximation is generally negligible , amounting to free energies less than the thermal energy  k_B T , for wormlike chains having contour lengths less than four times the persistence length .
After revision:  We find that the error in J arising from the harmonic approximation is generally small , amounting to free energies less than the thermal energy k_B T , for wormlike chains having contour lengths less than four times the persistence length .