[Y/Ba] versus [Fe/H] (upper panel) and [Y/Ba] versus [Ba/H] (lower panel). Symbols: Large blue-filled circles show present results on NGC 6522 member stars; large blue open circles show present results on non-member stars. Field stars: magenta-filled triangles denote red giants by Siqueira-Mello et al. (2016); green open circles mark dwarfs by Bensby et al. (2017); light blue open circles show metal-poor giants by Howes et al. (2016); acquamarine open circles represent metal-poor giants by Lamb et al. (2017). Globular cluster stars: orange-filled squares show NGC 6522 (Barbuy et al. 2014; green-filled pentagons represent HP 1 (Barbuy et al. 2016; tomato-filled pentagons show NGC 6558 (Barbuy et al. 2018c; magenta-filled pentagons represent M62 (Yong et al. 2014). The underlying coloured model corresponds to calculations for nucleosynthesis taking place in spinstars and in MRD supernovae (Cescutti et al. 2018 and references therein).