Abundance ratios vs metallicities for Mn, Co, Ni, Cu, Zn, Ba, Ce, Nd, and Yb for stars in the NSD (green triangles). Thin-disc and thick-disc stars from the solar neighbourhood are represented by red circles and yellow diamonds, respectively; stars observed 1 degree north of the Galactic centre are shown as blue squares; and stars observed in the NSC are indicated by black stars. The green open triangles represent the abundance ratios for the NSD stars based on alternative stellar parameters determined under the assumption that the oxygen abundances follow the thin-disc trend, which would imply typical uncertainties. See the main text for references.