A problem with the current version of Adobe Acrobat Reader prevents Macs users with Safari from ScienceDirect PDF articles. ScienceDirect has reported this problem to Adobe and Safari. Until it is fixed:
* Hold the control button, click on the PDF link and select “download link to disk.” Save the file to the hard drive and view it from there.
OR
* Use Mozilla Firefox instead of Safari, which does not seem to have this problem.