Cox Communication will cut 234 jobs in Rhode Island in the third quarter of this year.  The move will reduce the company's workforce in the state by nearly one-fifth, to 860.  Employees were informed yesterday the call center, which has been in operation since the 1980's, will be closed.  Cox is consolidating residential customer service operations nationwide.  A company spokeswoman says those losing their jobs may seek transfer to a call center in another part of the country or apply for another job with the company in the region.