Catch up on stories from the past week (and beyond) at the Slashdot story archive


Forgot your password?

Comment Re:Uh huh (Score 1) 570

Why add another layer instead of running it under the native OS?

  - you don't have a port of the service you want to run to the native OS you want to use,
  - the native OS you DO have a port to is a P.I.T.B. from a reliability, cost, security, and maintenance standpoint, but
  - you DO have an API adaptation layer (i.e. the application's code runs "on the iron" so there's no emulation penalty there) that runs on the OS you want to use and does a darned good job of supporting the parts of the API used by the service's code.

Comment Look up "Mammalian Diving Reflex" (Score 3, Interesting) 254

Have people been resuscitated after say, 30 mins or even an hour, and managed to have their brain functions relatively intact?

Absolutely. Look up "Mammalian Diving Reflex".

Brain damage from short-term clinical death happens primarily after revival. The valves routing blood to the parts of the brain that need it stick in the state they were in when the oxygen finally failed.

Muscles contract with stored energy and require metabolism to relax. "Valve off" is contracted, so when blood flow and oxygen is restored, the valves for regions of the brain that were turned down don't get oxygen and can't reopen - and without the blood flow they can't get oxygen, in a viscous circle. Raising the blood pressure to try to force them just blows the vessels, causing a stroke. The
nerves die over a half hour to an hour (and kill each other off through glutamate cascade, as dying nerves release glutamate that causes others to fire, deplete their remaining energy reserves, and die in turn.

Mammals, though, have a reflex related to deep diving. When diving deep, the increased pressure increases the partial pressure of oxygen, keeping things running until most of the oxygen is used up. Then coming back back up lowers the pressure further and can leaver the brain oxygen starved for long enough to produce the "valves stuck" phenomenon. To prevent this, mammals have the following reflex: When oxygen is running out AND the body (I think it's the back of the neck) is cold, the valves all open up, so any that get stuck are in the open position. Once oxygen is restored the blood flows, the nerves survive, the muscle gets repowered, and all is well - if thing hadn't been shut down long enough that too many cells died meanwhile.

This was discovered when some victims of drowning in cold water recovered just fine, with no brain damage, after half an hour or more of clinical death. I think the time before damage sets in is something between 25 and 45 minutes.

I don't know how CI's current protocols work. But ALCOR's are designed to include activating the diving reflex, if possible, so the brain's valves stick in the open position.

(This is more to encourage better perfusion of cryoprotectants than to try to make the brain restartable: As of the last time I looked the thought was that brains preserved - even by the best techniques available at the time - would require rebuilding by nanotechnology, so the idea was to preserve as much as possible of whatever might encode memory and personality.)

Comment Re:Uh huh (Score 1) 570

Running such software [which had been ported from UNIX to Windows but not to Linux] under Linux either meant running Linux on RISC hardware and using a compatibility layer or running the Windows version in Wine. Neither was particularly appealing.

It was a server! What's wrong with running the apps under Wine? What were they running that Wine would have caused them problems?

Comment Re:Input is not the limiter when coding (Score 1) 214

I know what you mean.
I purposely slow my typing down at work or else keys don't register because the keys don't respond fast enough and I go over the max KRO on the crappy keyboard.
Then I use mouse gestures when I browse the internet and people can't watch me or their heads explode because everything happens so fast and magically.

Comment Re:Not surprising (Score 1) 352

How many bright people drive cars without even knowing the simplest things about combustion engines and drivetrains? Are they all morons?

(I'm not the one who called them morons, and I don't think all of them are of sub-average intelligence.)

None, I hope. Everyone who drives should have basic knowledge of how cars work, how to check and add fluids and that there are things called drain plugs for various oils and fluids -- even if in modern vehicles they're almost impossible to get to.

Comment Re:Since when are digital projectors thousands? (Score 1) 236

Also, to be that bright, these don't use LEDs of course: they use very hot bulbs that need to be cooled down with very loud and large fans and cooling systems.

Very hot bulbs? Maybe these days. But the ones I'm familiar with, from a few decadesback, used carbon arcs. Same technology as the WW II antiaircraft spotlights. Incandescent carbon in a pit on the end of a quarter-inch or so carbon rod, being slowly vaporized by electron bombardment. VERY bright. Lots of ultraviolet, too. Plus a little bremstrahlung (thought he voltages are low enough that X-rays aren't all THAT much of an issue).

You BET it needed fans. They also carried off the carbon vapor, as the positive rod vaporized a few inches per reel, along with the nitrogen oxides from heating air that hot and letting it cool.

It's inverse square from the projector to the screen and inverse square back, for a total of inverse fourth power. Increasing the projector-screen distance from a desktop projector to a theater rig to a drive-in, at inverse-fourth-power, means you need a REALLY bright light. A quarter-inch rod with most of the end hotter than the surface of the sun is about right.

Slashdot Top Deals

"Laugh while you can, monkey-boy." -- Dr. Emilio Lizardo