I have seen a number of male nurses, most of whom are used when brawn is required. I suspect we see a fallout of parenthood, possibly $$. Those who can (either gender), proceed to the MD/DO/DDS (or now whatever super-nurses are called, PA's?). Those who can't, for cost or time constraints, make it to nurse and do ok. Although the hours suck.
In previous generations, nursing was a non-degreed (diploma) profession. It shifted to BA/BS-required in the 70's and 80's and for all I know is one where MA/MS is preferred for continued employment. Can one get a PhD in nursing, as I can imagine what the research might look like?
Yes. In a clinical setting they perform a lot of the same tasks that M.D.'s perform. There is actually a "great debate" of sorts going on clinical settings if Nurse Ph.Ds should be called Dr.s
http://www.nytimes.com/2011/10/02/health/policy/02docs.html?...
AFAIK, LPN/LVN programs generally do not require any degree, and at least some RN programs do not require a bachelor's degree (though the RN does require at least an associate's degree.)
That stuff doesn't show up on hacker news because this is a tech news site, not a nursing or psychology site.