Sentence:  On the contrary , even in the heart of `` the Bible belt '' itself , as can be attested by any one who is called to work there , the industrial and technological revolutions have long been under way , together with the corresponding <WSD>changes</WSD> in man 's picture of himself and his world . 
Meaning of the word marked with <WSD> tags:  a relational difference between states; especially between states before and after some event