By Tara Bannow  | February 19, 2019 Despite an investment loss in 2018 that mirrors some of its peers, not-for-profit Mayo Clinic managed to keep its income from current activities stable.  Rochester, Minn.-based Mayo’s investment results fell sharply in 2018 year-over-year. The system reported a $369 million investment loss compared with a gain of $595 million in 2017. …