Figure 8

Strength of node connectivity visually mapped from values of${\mathit{s}}_{\mathit{i}}$along (A)-(B) Ivory Coast Tribal ; (C)-(D) Ivory Coast Administrative ; and (E)-(F) Portuguese Administrative boundaries. Border categories are separated according to whether they contain the main city of the respective country (i.e., (A) & (C) Abidjan, Ivory Coast and (E) Lisbon, Portugal). Histograms display the distribution of the border strength values along the border(s). Black vertical lines are indicative of the mean positive border strength value.