1. Department of Biological SciencesNorthern Arizona University Flagstaff AZ USA
2. Department of Human PhysiologyUniversity of Oregon Eugene OR USA
3. VA Portland Health Care System Portland OR USA
4. Department of NeurologyOregon Health and Science University Portland OR USA
5. KBRCardiovascular and Vision LaboratoryNASA Johnson Space Center Houston TX USA
6. Oregon Heart and Vascular Institute Springfield OR USA