There are some nations competing in these Winter Olympics that are shaking off the rust of international play and others that are just happy to be there.  The United States is certainly neither, seeking revenge for its overtime loss to Canada in the 4 Nations Face-Off final and validation for their IIHF World Championship last year.  The Americans begin that expedition against Latvia on Thursday afternoon in the first of three preliminary games.  The Latvians had the worst pre-tournament gold