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This results in the twin effects of wider and shallower regions of social activity around each person ( further exacerbated by electronic communication which can be seen as a form of virtual mobility ) , and a degradation of the social and physical environment brought about by the high speed traffic ( as theorised by urban designer Donald Appleyard ) .
 Donald Appleyard
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: media, plant, vehicle, astronomical object, time, disease, animal, location, person, organization, mythical figure, food, biology, geographical phenomenon, instrument, event 
Text: {0} 
Answer:
 Donald Appleyard