SUBMISSION

Electronic submission: All submissions MUST be in pdf format. Attach a pdf file of the ENTIRE work (including figures) to an e-mail and send to scarab@u.arizona.edu.   What to submit AFTER acceptance: Submit the text files in one of the following formats: Word, Wordperfect, Word for Mac.   Send figure files separately. Our compositors prefer pdf format but tif format may work in some cases. Produce the pdf files from within the software used to create the figure. Before you do that, turn off all pdf compression.   Also, please send one additional pdf of the ENTIRE work (including figures) for publication as an Early Edition to scarab@u.arizona.edu. You may put graphs, tables and legends in their appropriate positions in this version of the paper, if you wish. Your choice. But do remove line numbering from this version as well as all other information relating to the review process.