We're sad to report that @cristo is taking leave from the mentorship due to some exciting life changes. @cristo was a great addition to Physics Forums for over 8 years! We've been assured that once his real life settles down he'll be back being active in the community again! We will wait patiently for that day! To help fill the space of @cristo leaving, we are very excited to have @NascentOxygen join the team. @NascentOxygen has been friendly and trusted member for several years now. We're lucky to have him and look forward to his contributions.