A brief (sort of)  audio commentary is attached directly below.  The disciplined listener might want to illustrate the “sound track” by opening the pdf to the paper itself – first – giving HELIX time to materialize before punching the audio button.

Paul’s Commentary

[audio:http://pauldorpat.com/wp-content/uploads/2012/05/01-05.mp3|titles=Helix Vol 1 No 5]