Regarding Roy Weintraub's nice points about conceptual border crossings, and Kevin Hoover's insight that "whether someone is an expert in a community ... depends in part on what uses members of that community put their contributions to," we might see border crossing contents as by definition metaphorical - since translated from one domain to another - and treat the experts as those able to domesticate and make prosaic that metaphorical content within the context the inheriting field (Maurice Lagueux's argument about the fate of metaphors).  So the experts are also integrators who tame the crossings.

John Davis