Informix Connect 2.80 and Isolation Levels

Does anyone know if there is a way to set the isolation level in the connect string? Or is there a way to set this either by user or on the Informix Client itself so that it is always default read uncommitted. I use an application that connects to databases. Problem is I can not set the isolation level in the product. If I could set it either in the connect string, in the client, or have an isolation level pre set per database user I could force the isolation level I want by the query versus by the database. Dean Colter