The publisher regrets that in the above article the fourth author's name was spelt incorrectly. It is now represented correctly above as Florent de Vathaire.

This study provides evidences that oral CS decreased pain and improved knee function. The 3-month intermittent administration of 800mg/day of oral CS twice a year does support the prolonged effect known with symptom-modifying agents for OA. The inhibitory effect of CS on the radiological progression of the medial femoro-tibial joint space narrowing could suggest further evidence of its structure-modifying properties in knee OA.

A theoretical study of the isotopic-mass dependence of the internal transitions of Fe 2+ at a cation site in a cubic zinc-blende semiconductor is presented. The model used is based on crystal-field theory and includes the spinorbit interaction and a weak dynamic Jahn-Teller coupling between the 5 Γ 5 excited manifold of Fe 2+ and a local vibrational mode (LVM) of Γ 5 symmetry. The mass dependence of the LVM frequency is described, in the harmonic approximation, within two different limits: the rigid-cage model and a molecular model. In the rigidcage model, the Fe 2+ ion undergoes a displacement but the rest of the lattice is fixed. In this case, a simple M -1l2 dependence of the frequency is obtained and the Jahn-Teller energy, E JT is independent of the mass. In the molecular model, the four nearest neighbors of the magnetic ion are allowed to move and the LVM then behaves as the Γ 5 mode of a MX 4 tetrahedral molecule leading to a more complicated dependence of the frequency on the isotopic mass and to a mass-dependence of E JT . The theoretical results obtained with these two models are compared with the observed isotopic shifts of the zero-phonon lines in InP:Fe and GaP:Fe corresponding to an optical transition between the vibronic Γ 1 ground state and the lowest Γ 5 state originating from the 5 Γ 5 excited orbital multiplet. A prediction of the isotopic shifts of the zero-phonon line in GaAs:Fe is also presented.

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Optical absorption and emission measurements of Cu 2ϩ as a substitutional impurity in cubic ZnS and ZnTe are analyzed by means of an electron-phonon coupling model. The 2 D term of Cu 2ϩ is split by a crystal field of tetrahedral symmetry into a 2 ⌫ 5 orbital triplet and a 2 ⌫ 3 orbital doublet. Optical transitions have been observed between these two multiplets in ZnS:Cu 2ϩ and within the 2 ⌫ 5 ground state in ZnTe:Cu 2ϩ . The theoretical model is based on crystal-field theory and includes the spin-orbit interaction and a dynamic Jahn-Teller interaction between the electronic 2 ⌫ 5 states and a transverse acoustic phonon of ⌫ 5 symmetry. Starting from the ten spin-orbit wave functions appropriate to the orbital triplet and doublet manifolds, the symmetryadapted vibronic basis is constructed and used to diagonalize the Hamiltonian matrix. Phonon overtones up to nϭ14 are included to ensure convergence of the energy eigenvalues. The measured positions and relative intensities of the spectral lines are described with good accuracy by the theoretical model, including covalency effects. In ZnS, comparison between theory and experiment yields the following values of the physical parameters: the crystal-field splitting ⌬ϭ5990.6 cm Ϫ1 , the spin-orbit coupling constants 1 ϭϪ667 cm Ϫ1 and 2 ϭϪ830 cm Ϫ1 , the phonon energy បϭ73.5 cm Ϫ1 , and the Jahn-Teller stabilization energy E JT ϭ474.5 cm Ϫ1 . The corresponding parameters in ZnTe are ⌬ϭ6000 cm Ϫ1 , 1 ϭϪ888 cm Ϫ1 , 2 ϭϪ830 cm Ϫ1 , បϭ38.8 cm Ϫ1 , and E JT ϭ468.5 cm Ϫ1 .