Mark Ryan is a name that could be associated with several different individuals across various fields, including but not limited to acting, writing, and education. Without a specific context, it is challenging to provide an accurate short description. If referring to an author, the name might be connected to someone who has written books or articles in a particular domain. Additional details or context about the works or topics associated with Mark Ryan would be required to offer a precise description. If you have more information about which Mark Ryan you are inquiring about, please provide it so I can assist you further.