3. Telomere assessment. The length of telomeres, the DNA caps at the ends of chromosomes, is emerging as an indicator of stress-related biological aging: Data have implicated accelerated telomere shortening in the context of increased psychological stress and stress arousal [10, 11]Blood drawn by a licensed phlebotomist (4 mL for telomere assessment) at baseline (0 weeks) and 16-weeks will be assayed for telomere length. Samples will be frozen and transferred on dry ice to the Blackburn Laboratory at UCSF, located at 600 16th Street, San Francisco, California, by a laboratory technician. Assays will be completed according to the polymerase chain reaction (PCR) method..