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.
When one of these valves malfunction, it can cause the heart to enlarge and lead to other complications, including congestive heart failure. Mechanical heart valves and biological heart valves are two different types of prosthetic heart valve replacements which mimic the functions of a human valve.