IGF package:nlme R Documentation _R_a_d_i_o_i_m_m_u_n_o_a_s_s_a_y _o_f _I_G_F-_I _P_r_o_t_e_i_n _D_e_s_c_r_i_p_t_i_o_n: The 'IGF' data frame has 237 rows and 3 columns. _F_o_r_m_a_t: This data frame contains the following columns: _L_o_t an ordered factor giving the radioactive tracer lot. _a_g_e a numeric vector giving the age (in days) of the radioactive tracer. _c_o_n_c a numeric vector giving the estimated concentration of IGF-I protein (ng/ml) _D_e_t_a_i_l_s: Davidian and Giltinan (1995) describe data obtained during quality control radioimmunoassays for ten different lots of radioactive tracer used to calibrate the Insulin-like Growth Factor (IGF-I) protein concentration measurements. _S_o_u_r_c_e: Davidian, M. and Giltinan, D. M. (1995), _Nonlinear Models for Repeated Measurement Data_, Chapman and Hall, London. Pinheiro, J. C. and Bates, D. M. (2000), _Mixed-Effects Models in S and S-PLUS_, Springer, New York. (Appendix A.11)