Barium-to-strontium ratio as a function of [Ba/H] in Sculptor seen in orange, compared to the Milky Way halo stars presented in grey. The open circles correspond to HE 1219-0312, HD 140283, HD 122563, HD 88609, and HE 2327-5642, five Milky Way halo stars for which the odd-A fraction could be estimated. Sextans is shown with green triangles, Fornax with a blue triangle. The Ursa Minor population is shown with purple stars while the two Carina stars are seen in pink circles. The full references are given in Sect. 5.1.