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Dr. Katsuma Yagasaki a Japanese physicist at the  University of the Ryukyus  in  Okinawa  has estimated that the atomicity equivalent of at least Nagasaki bombs has been released into the global atmosphere since 1991 from the use of depleted uranium munitions .
 city of headquarters: University of the Ryukyus, Okinawa
Given a phrase that describes the relationship between two words, extract the words and the lexical relationship between them. The output format should be "relation1: word1, word2; relation2: word3, word4". 
Option: cities of residence, top members employees, members, alternate names, origin, state or provinces of residence, title of person, spouse, city of headquarters, NA, founded by, state or province of headquarters, employee of, countries of residence, country of birth, founded, subsidiaries, country of headquarters 
Text: {0} 
Answer:
 city of headquarters: University of the Ryukyus, Okinawa