Hi,
I tried to open the link you provided and it seems to be broken. On the other take into account that as far I know there is no official guidance regarding Entity Framework in Prism as it was designed as a guidance for the client-side of the application. Therefore, in case your concern is related to the implementation of this framework I believe you could find better guidance on this subject for example in the ADO.NET Entity Framework Forums.
Regards,
Agustin Adami
http://blogs.southworks.net/aadami