I've seen dynamic memory work better with other guests though, so it might be either something I'm doing wrong, or a side effect of the File Server role. Either way, I've gotten better results with setting static amounts of RAM on my file/DFS servers.
A biological heart valve is a heart valve recovered from a donor or created from donor tissue. A cadaveric valve comes from a human donor. Bovine valves are recovered from cows and porcine valves come from pigs.
1 Sometimes, a patient's own tissue can be used for valve replacement (called an autograft). 2  Patients with biological valves usually do not need to take blood-thinning medicines. 3  These valves are not as strong as mechanical valves, though, and they may need to be replaced every 10 years or so.