No they don't. Matt Cutts has made that clear many time. Too totally different departments in Google. Watch this video: http://www.youtube.com/watch?v=CgBw9tbAQhU
i thinks it's was automatically give effect for PR .... If traffic is up so PR will increase too and Goolge Analytics will help you to remote you're traffic ... you should doing SEO techniques (on page and off page) more better with focus and continues .... Thanks for shared this