PROFESSIONAL SERVICE means work rendered by an independent contractor who has a professed knowledge of some department of learning or science used by its practical application to the affairs of others or in the practice of an art founded on it, which independent contractor shall include but not be limited to lawyers, doctors, dentists, psychologists, certified registered nurse anesthetists, veterinarians, architects, engineers, land surveyors, landscape architects, accountants, and claims adjusters. A profession is a vocation founded upon prolonged and specialized intellectual training which enables a particular service to be rendered. The word "professional" implies professed attainments in special knowledge as distinguished from mere skill. For contracts with a total amount of compensation of fifty thousand dollars or more, the definition of "professional service" shall be limited to lawyers, doctors, dentists, psychologists, certified registered nurse anesthetists, veterinarians, architects, engineers, land surveyors, landscape architects, accountants, claims adjusters, and any other profession that may be added by regulations adopted by the office of contractual review of the division of administration.