Showing posts from September, 2010
Parasitism among City-Dwellers of the Past:  the Civilizations’ Cost for a Prosperity There were many civilizations in a history of mankind. Each civilization eager to survive under different environmental conditions. Especially as for the highly-populated area like big cities of kingdoms and empires, they always stood at the crossroad of survival. They always faced serious problems of public hygiene because many people lived in narrow districts of the cities where modern concept of . To maintain large numbers of people, they tried to develop an effective product machine for sufficient calories and nutrients. Different kinds of disasters e.g. (droughts and floods) always threatened the existence of human beings in the cities. Great civilizations always tried to overcome the challenge of mother nature; and in many cases, it was successful. However, the survival of big cities in pre-modern age was not fulfilled for free. It costs them much expense: increasing risk of parasite in