my name is Hans-Detlef Carstens from Germany. I try to implement a Family-tree of the Derners. I myself am a member of this Family. I suppose, your wife Janice is a great-granddaughter of Anna Dethmann, who emigrated in 1870 from that village (Hohn in Schleswig-Holstein), where I live, to Clinton, Iowa.
I hope to get some further informations from you. If you are interested, I can send you a link to my Family-tree. There are more than 6.000 persons included.