Describe any two of the above cases (Ebola, HIV/AIDS, Chagas, or Schistosomiasis) from the standpoint of the relationships between (1) culture/economy and disease; (2) cities/towns and disease; (3) environmental change and disease; and (4) human ecology and disease. Within the above framework, how do the two diseases reflect "negative externalities" and "Karl Polanyi's Paradox" (as described in GPCC)