[Computational-biology] about Highly Conserved Elements (HCEs)

[Jim]

Hi!

I am studying a paper "Evolutionarily conserved elements in vertebrate,
insect, worm, and yeast genomes" (Genome Research 2005).
This paper mentioned Highly Conserved Elements (HCEs) that I want to
obtain.
I plan to utilize the phastConsElements17way table (from
http://genome.ucsc.edu)
and set a threshold of the score like 200.
Than I may obtain a set of conserved elements (score > 200).
Is this procedure correct?
However, I can not find the threshold for HCEs in the paper.
Could you tell me how to determine the threshold for HCEs?

Best regards,

Jim (Chun-Chi Liu)
Homepage: http://biochip.nchu.edu.tw/ccliu/
Institute of Computer Science,
National Chung-Hsing University, 
Taichung, Taiwan, ROC.