Wikipedia:Reference desk/Archives/Science/2008 October 2

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October 2[edit]

List of official lab names[edit]

I have been trying for a long time to find a definitive list of all official medical laboratory (pathology) lab names. I have been able to find books containing all labs accepted by certain services, such as LabCorp. I need this to be electronic, not in a book. I also need it to be accurate. For example, "creatinine" is not a valid lab name. It must be "creatninie, serum" or "creatinine, urine" - two very different labs. Does anyone know of a list available online? I'm even happy to screen scrape a website if it actually has all the lab names. Just to note: I did try to use all the pathology items in CPT, but it is missing all incidental labs that you can't bill for. Also, you are supposed to license CPT just to know it exists. I hope everyone here has a license since I just mentioned it! -- kainaw 04:16, 2 October 2008 (UTC)

Well hey, if you know about LabCorp, why not call them up? Ask for "customer service, I need a full list of path lab names" - whoever is answering the phone will be confused and impressed enough that they will look at the list of internal numbers and pick one. Then you will get someone who was forwarded an outside call and will get your question answered. If it comes up, don't say "I'm just a student", say "I've just been given this project and I need to gather background information so we can get started". (And if you're not a student, whatever...)
Someone at LabCorp will know where that entire list is - please post it back here and into whichever article is most appropriate! Franamax (talk) 07:20, 2 October 2008 (UTC)


One thing I think I've noticed is that when you have a headache, if you lie on your back, it tends to get better, if you look downward, it tends to get worse, and if you lie to one side, the pain tends to move to that side. Presumably this would be because some sort of fluid (too high pressure of blood?) is causing the headache, and then it slowly drains certain ways depending on which way your head is aligned. My question is - is there anything to this at all, or is this just a placebo effect and I'm imagining a change in how much the headache hurts that doesn't really exist? And if there is some sort of basis to it, what would be the explanation? (I know you're not supposed to give medical advice, but come on. It's a headache.) zafiroblue05 | Talk 05:32, 2 October 2008 (UTC)

This isn't medical advice - but oohh baby, I know that feeling! I doubt it's blood, but certainly a sinus headache results from inappropriate pressure in the sinuses, and this can move around as you shift your head. There's also the factor of muscle tension, depending on your exact head position, you can build up the tension without knowing it. Depending on the cause of the headache, your balance organs may be affected too. If it's a migraine, all bets are off and it's just a world of pain.
It really comes down to your own particular headaches though, and your own experience. Headaches result from many different causes (including brain tumours, if that makes you feel any better :). If your headaches result from hangovers, the best position is non-bending-elbow the night before. So really, ask your doctor, just like we always say. :) Franamax (talk) 07:06, 2 October 2008 (UTC)
  • Might also be blood pressure related. If your lieing down maybe your more relaxed? ---J.S (T/C/WRE) 07:25, 2 October 2008 (UTC)
First, you must find the cause of your headache. It is rather dumb to expect random users on the Internet with no medical experience to diagnose the cause of your headache. That is something a medical professional can do. Once you know the cause, feel free to come back and ask if there is a scientific reason that your specific type of headaches may change based on the position of your head. Anything said here could be based on a terrible misdiagnosis as your headache could be anything from purely imaginary, to simple dehydration (very common), to a brain tumor ... even to having a nail in your brain. In head trauma it is common to forget the incident. So, you could get shot in the head with a nailgun, forget the incident, and walk around not knowing you have a nail in your brain. -- kainaw 12:11, 2 October 2008 (UTC)
Before anyone laughs at Kainaw's suggestion, note that it's possible to be shot – in the forehead – and not realize you have a bullet in your skull: [1]. (There are a number of similar cases in the medical literature. While bullets to the head are normally both obvious and rapidly debilitating, there are exceptions.) TenOfAllTrades(talk) 16:24, 2 October 2008 (UTC)
I believe at this point it is traditional to mention Phineas Gage, with a comment such as "Call that a headache ? ...". Gandalf61 (talk) 10:20, 3 October 2008 (UTC)

Name this bug[edit]

Locale: Vancouver (actually Surrey) BC, oceanic climate or "inter-coastal Pacific-Northwest" - take your pick.

Diagnostics: body length 20-25mm, diameter 10-12mm. Body with three distinct black/white bands "salient" (45° dorsal leading - like "///"+head ). Four dragonfly-style wings. Distinct proboscis.

Activity: Using long proboscis at multiple flowers.

I've never heard of anything like this. Does anyone have some clues? Franamax (talk) 06:49, 2 October 2008 (UTC)

If it has a long proboscis, and feeds at flowers, it sounds like some sort of moth. If the four wings flap independently (they're probably moving too fast to tell), then it is not a moth. It's difficult to say what it is without a picture.CalamusFortis 15:06, 2 October 2008 (UTC)
Do any of the pictures in Hoverfly look familiar (assuming that you're wrong about the four wings)? Deor (talk) 15:38, 2 October 2008 (UTC)

Hoverfly, specifically Chyrysotoxum intermedium elicited an immediate response on viewing the samples. Mommy doesn't have to go to the home yet, it seems the bug does exist :) The caveats were that the observed head was smaller in relation to body size and the proboscis was significantly more extended. Given the approx. 6000 species involved, I declare a semi-exact match. Deor, keep cleaning that article up if you can, the bottom 5 sections are quite confusing (but it's all good). Thanks! Franamax (talk) 06:57, 5 October 2008 (UTC)

Is this Rose quartz?[edit]

Is this really what I think it is?

Is this actually rose quartz? It's my first guess, but I'm not a geologist... so I figure it's time to get a second opinion! ---J.S (T/C/WRE) 07:25, 2 October 2008 (UTC)

The pink parts look like rose quartz, but the yellow bits would be iron staining limonite. Graeme Bartlett (talk) 13:00, 2 October 2008 (UTC)
That would fit. ---J.S (T/C/WRE) 17:50, 2 October 2008 (UTC)
Axully, this looks more like Orthoclase feldspar, but it could be rose quartz. IDing a mineral sample from a photograph is difficult... 03:42, 3 October 2008 (UTC)
I tried to get a high-quality macro photo of it to help identification. Unfortuantly this stone is under a few feet of water in Folsom Lake. :) ---J.S (T/C/WRE) 01:23, 6 October 2008 (UTC)

Driving a T-72 tank[edit]

As we know from the news, Somali pirates have captured a ship with 33 T-72 tanks. Of course, the US, UK and Co. will not let them go away with it, but if they were able to unload the ship, would they also be able to use these tanks? Mr.K. (talk) 08:08, 2 October 2008 (UTC)

Well driving a tank will require knowledge of how to operate the tank. Without knownig about the state of these stolen tanks, I suspect yes...if they could unload them they could maybe 'use' the tanks to some degree (perhaps basic manouvering), but perhaps not all - it depends on how intutitive the tank's controls are (judging from what i've seen on tv - not very at all!!). (talk) 08:51, 2 October 2008 (UTC)
The main thing is, they will be able to sell the tanks farther inland, to people who are able to ask around for someone who knows how to run a T-72. Such operators exist and can be hired. And realistically, a machine is a machine, you can always figure out how it works.
The sea-pirates themselves likely won't try to operate the tanks. The first time they try to take one out to intercept a ship on the high seas, they will see the big flaw in that plan. And anyone who they sell on to will quickly run up against the spare part problem once something breaks. Their rational strategy is to ransom back the tanks and ammunition, same as they do with ships, standard cargo and crew. Franamax (talk) 09:58, 2 October 2008 (UTC)
Yes, and perhaps there are some Russian trained mercenaries deep into Somalia that always wanted to drive such a thing and know more or less how to do it. At least driving the old model doesn't seem to be that difficult, as this BBC articles shows. Mr.K. (talk) 10:28, 2 October 2008 (UTC)
If you look over this page, you'll see that the T-72 and its variants have been used by many countries so there are plenty of people that are fully trained in their operation.--droptone (talk) 11:26, 2 October 2008 (UTC)
When I was in 29 Palms, they would let kids drive around the T-72 and M1A1 tanks on Tankers Day. I'm certain that it is considered a security risk now, but there are plenty of kids who are now adults and know how to, at a minimum, make the tank for forward and turn. -- kainaw 12:05, 2 October 2008 (UTC)
The T72 uses standard dual stick controls, with each stick controling its sides engines and brakes, and a single gear lever. Actually driving the tank should be fairly easy, at least if you don't care about running over things. Using the gun might be hard but the gun contains an autoloader, so that is no issue, and moving the turret will be easy too. Hitting things at a distance with such an old tank might be hard as it lacks the fancy laser range finding and targetting kit of a modern tank. The machine guns are standard Russian machine guns that many of them know how to use already I'd wager. I'm sure with a couple of weeks of experimenting they could figure out how to use a tank in some capacity. The main issue is going to be fuel. Tanks use fuel so fast it would make an SUV swoon. (talk) 12:23, 2 October 2008 (UTC)
If you look at news reports, most people aren't particularly worried about the tanks. That's because they are rather large objects which won't easily be offloaded from the ship which is surrounded by several navy vessels as well as under air surveilance. However the other weapons and ammunition, which could more easily be offloaded are of far greater concern. Also, the tanks are worth rather a lot of money meaning that people would like to get them back Nil Einne (talk) 13:06, 2 October 2008 (UTC)
Presumably these tanks come with an owner's manual in the glove compartment? Or, more likely, many thousands of pages of documentation? --Sean 14:33, 2 October 2008 (UTC)
In Somali? Nil Einne (talk) 17:32, 2 October 2008 (UTC)
The interwebs has translators. :) ---J.S (T/C/WRE) 17:53, 2 October 2008 (UTC)

Chinese contributions to engineering[edit]

what are the contibutions of the old chineese era in the field of engineering? —Preceding unsigned comment added by Kim014 (talkcontribs) 12:42, 2 October 2008 (UTC)

oil rig wheelbarrow great wall of China, water control. Graeme Bartlett (talk) 13:04, 2 October 2008 (UTC)

Gunpowder,fireworks? (talk) 13:18, 2 October 2008 (UTC)

Blast furnaces, high temperature kilns, ceramics. There's a gigantic list at List of Chinese inventions to look and pick through. Sjschen (talk) 15:45, 2 October 2008 (UTC)
Flight? Plasticup T/C 15:55, 3 October 2008 (UTC)

Coloured lights used on CSI[edit]

After watching several episodes of CSI, I have seen the characters use several kinds of lights to detect otherwise invisible markings (eg blood which had been cleaned, stains on sheets etc). These lights vary in colour, are always seem to require either a screen to shield the user's eyes from the beam (a coloured screen attached to the light), or for the user to wear coloured goggles. My question: what are these lights (I was going to guess ultraviolet)? Why the need for the coloured screen/glasses? And why do they change colour from episode to episode - are different "colours" used to detect different substances/markings? Thanks very much in advance! — QuantumEleven 12:55, 2 October 2008 (UTC)

This is probably using the same CScIence that allows them to go "Zoom! Now enhance" and make some grainy pixelated CCTV footage show you the face of the killer (I swear to god they rotated the position of the image to show his face once). In other words total rubbish. (talk) 13:17, 2 October 2008 (UTC)

Actually, it's quite reasonable. Skiers tend to prefer amber-colored sunglasses, for instance, to maximize the contrast of their particular environment. Using something similar to highlight a crime scene makes sense. — Lomn 13:30, 2 October 2008 (UTC)
The two specific instances that the original questioner brings up are both indeed ultraviolet light. Semen stains fluoresce under ultraviolet lamps; for fun, bring one to the next hotel you stay in. And cleaned blood stains are detected by spraying the area with a mixture of phenolphthalein and hydrogen peroxide, and then looking at the area with an ultraviolet lamp. This is also called the Kastle-Meyer test. Note that these are presumptive tests only: they can't actually identify the stain as semen or cleaned blood, but they can tip you off that the stain is there so you can perform further testing to actually identify what made the stain. The goggles, as you note, are used to protect the eyes from high-intensity ultraviolet radiation. - Nunh-huh 13:59, 2 October 2008 (UTC)
Thanks for the answers, Lomn and Nunh-huh. The glasses to enhance contrast make sense, and to protect the user's eyes (in which case, the little plastic shield on top of the light probably doesn't do a whole lot of good?). I'm still curious as to the changes in light colour (although that might be down to "it looks cool" on the part of the producers of CSI?) — QuantumEleven 14:51, 2 October 2008 (UTC)
There's a little discussion about potential danger to the eye in the ultraviolet article. You might also be interested in Luminol. --LarryMac | Talk 15:30, 2 October 2008 (UTC)
The change in light colour? Do you mean the fluorescence of whatever UV radi. is being shone on or the result of the light from fluorescence being filtred by the glasses? Sjschen (talk) 15:36, 2 October 2008 (UTC)
I would speculate that since the show is recorded and broadcast electronically, a white balance must be determined for each scene. If the balance is a little in one direction or another, when the image ends up on your TV it may have either a more purple or more blue hue to it, depending on the rest of the scene. -- (talk) 16:45, 2 October 2008 (UTC)
Have you watched CSI? I don't watch it regularly but caught part of an episode of CSI Vegas while waiting for my take-out food to come in. The whole thing is practically filmed in the dark and every light is tinted. It's "dramatic lighting" taking to the most ridiculous, preposterous extreme (where courts of law look like night clubs). I don't think it's an issue with them adjusting their TV. -- (talk) 22:25, 2 October 2008 (UTC)
CSI Miami is weird. The sky's green and all the other colours are unnatural. The overly forced, mannered, unnatural acting of David Caruso is in keeping with the unnaturality of the colours. I can't recall him acting that way in other shows I've seen him in, so I guess it's how he or the producers want his character to be. It sure gets my attention every time I watch it. But I thought actors weren't supposed to be drawing attention to their acting; for that hour we're supposed to be believing he really is the person he's playing. -- JackofOz (talk) 00:55, 3 October 2008 (UTC)
It's worth saying one more time. THIS IS FICTION...IT'S NOT REAL! Nothing that happens on these shows has to have any scientific validity whatever. CSI is notorious for performing tests that (in reality) take months in mere seconds - they have rolled every kind of separate lab into a single lab - they've taken away all of the super-careful (and super-tedious) paperwork that has to go on - the control tests - the need to preserve evidence for the defense lawyers to do their own tests on. Long waiting lists for some kinds of test are replaced by someone typing something into a computer and getting an answer in seconds. So the fact that there are some fancy colored lights that show who-knows-what has only coincidental resemblance to what REALLY happens in real forensic labs. SteveBaker (talk) 01:19, 3 October 2008 (UTC)
Yeah. But not everyone realises that, which is why there's the CSI Effect. I wonder how much the technical advisers are being paid for these shows that distort reality so massively. -- JackofOz (talk) 02:22, 3 October 2008 (UTC)

Going back to what touched on; the seemingly crazy enhancement of CCTV and photographs. Obviously you can't tease data out of a picture taken at a low resolution because it just isn't there. What you could do, in principle, is extrapolate from base data. Is that still then admissable as evidence, given that it's effectively "made up" and doesn't exist outside of a (clever) computer algorithm? I guess what you could do is deliberately get some low-res photos of known subjects (i.e. you have higher res copies) and then run your "enhancer" on them, and then compare the results. I'm concentrating on computational examples, but of course the human mind is adept at seeing patterns in this fashion. I've seen tons of episodes where they have a scrap of company headed paper, and manage to work out which firm it is from that. What's the difference? --Rixxin 19:15, 3 October 2008 (UTC)

I certainly wish I had a dollar for every movie/TV show where our hero points at a screen and says "Zoom in zoom in some more...enhance...enhance some more...AHA! That proves it was Colonel Mustard in the Dining room with the Candlestick!". Well, in truth, there really is only a very limited amount of enhancement you can do - the information simply isn't there - and you can't get information from nowhere. There is a LITTLE that can be done though - if you know a lot about the lens/mirror system that was used to take the original image. There were some algorithms developed on the Hubble telescope that provided modest enhancement when the mirror was discovered to have been ground incorrectly. But if you don't know the exact characteristics of the lens, or if the limiting factor is not the lens but the grain in your film or the resolution of your image sensor - then those "enhancement" tricks are purely cosmetic - to trick the eye into believing the image is sharper without actually revealing any more detail. The "standard" trick is called an "unsharp mask" - what you do (in effect) is to take a copy of the image, deliberately blur it a bit - and then subtract the blurry version from the original. Amazingly, this really does remove some of the blurriness and results in the image looking much crisper. If you overdo it, you end up with the edges in the image standing out and actually obscuring "real" details in the photo. However, this won't help you to solve the murder by reading the date off of that newspaper that some guy in the background of the shot is holding! SteveBaker (talk) 13:09, 6 October 2008 (UTC)
There are also some algorithms that can extract a sharper image from a series of related images - e.g. if you had some grainy video of a UFO flying across the sky, they might be able to give you a single, not-as-grainy photo of a frisbee. It's still got its limitations, though. Confusing Manifestation(Say hi!) 22:54, 6 October 2008 (UTC)

sex change m to f[edit]

when a man changes sex. do she get the same fellings as awoman —Preceding unsigned comment added by (talk) 20:26, 2 October 2008 (UTC)

I believe not, although you might like someone to verify this if it is important you are correct. Anonymous101 (talk) 20:37, 2 October 2008 (UTC)
You might be interested in our articles Transwoman and Sex reassignment surgery (male-to-female). --Allen (talk) 21:10, 2 October 2008 (UTC)
Men already have the same feelings as women, however sex hormones do affect the way the two sexes deal with their feelings. Men getting a sex change spend a long time taking women's hormones before the surgery and this could have an effect on the way they experience their emotions. -- Mad031683 (talk) 21:15, 2 October 2008 (UTC)
I suspect that by "feelings" the questioner was referring to "sensations" Plasticup T/C 04:34, 3 October 2008 (UTC)
How could she possibly know? --ColinFine (talk) 18:55, 4 October 2008 (UTC)