I am an instructor at Rutgers University (campus at Newark, New Jersey, USA). The old axiom “one professor-one class” does not apply to me, since I teach various courses both at the undergraduate and graduate levels at Rutgers University and the New Jersey Institute of Technology, through our Federated Department of Biological Sciences.
My use of PDFs dates back to the early nineties when I needed to keep my research data (in my new lab) without having to access my paper-based notebooks (which usually remain in the principal investigators’ laboratories). Needless to say, this was eons before E-Notebook and other specialized software.
The reason I use PDFClerk Pro is because I find it extremely useful in adapting or preparing PDFs and modifying them for class. PDFClerk has many features that should be present in Adobe Acrobat—but are not. I mostly enjoy pasting graphics and adding different kinds of “Annotations.”