Dr. James Conca is an expert on energy, nuclear and dirty bombs, a planetary geologist, and a professional speaker. Follow him on Twitter @jimconca and see his book at Amazon.com
This is an example of the gestural mode to communication. The article provides the doctor twitter and published books at amazon for people to interact with him. It provides the opportunity for the readers to connect and understand Conca beliefs/points of view and his ideals from his books and postings on Twitter.