Wikipedia:Reference desk/Archives/Science/2006 December 20

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December 20

New cochleas

Due to the ossification of a person's cochleas, a cochlear implant is only partially provided. Typically, a string of electrodes are fed into a cochlea that has dead or damaged "hairs". However, with cochlear ossification, such threading is not possible. A drill, being straight, cannot make room along the spiral shape of the cochlea, but instead penetrate the cochlea at two angles for insertion of only a partial array of electrodes. This damages the cochlea permanently, which is why cochlear implant users generally leave one ear available for future advancements. My question is this: What would be the science behind providing someone with new cochleas, if the damaged cochlea was the reason for a person's deafness? I imagine two methods -- growing cochleas in a petri-dish in the lab (someone grew an organ successfully this past month, so this seems possible), or the implantation of cochleas from an organ donor. What would be the difficulties with these methods as well? —Erik (talk • contrib) - 00:32, 20 December 2006 (UTC)

In mammals, it can be tricky to get axons to grow to their "normal" targets in an adult brain. Regeneration and replacement in the vertebrate inner ear. --JWSchmidt 01:02, 20 December 2006 (UTC)

What about cochlear implantation, not the artificial method? —Erik (talk • contrib) - 01:55, 20 December 2006 (UTC)

Same problem as JWSchmidt pointed out: it's not just the ear it's the brain that has lost the ability to hear. --Cody.Pope 03:24, 20 December 2006 (UTC)

Not sure if I understand. Where would the axon growth take place? When people go deaf, their hearing can be restored with cochlear implants because the technology serves as a substitute function to the cochleas. I don't think it means that the brain loses the ability to hear, as I know someone who has been deaf for 7 years and will get a cochlear implant in the coming year based on doctor's recommendation. What is the difficulty in placing organ donors' cochleas in deaf people to replace the damaged cochleas -- is it the connection between the new cochlea and the old brain that must be made? —Erik (talk • contrib) - 03:47, 20 December 2006 (UTC)

When signals from a sensory organ cease traveling to the brain, the areas of the brain receiving those signals go into atrophy. Meaning that over time, those brain areas decay. Depending on the age of the individual, reconnecting or replacing the organ can have some effect. However, as we age the brain become less plastic, meaning that it becomes harder and harder to re-grow/re-connect those areas lost to atrophy. So, concerning a cochlear implant, whether it be artificially or an actual donor implant, the amount of information that brain can interpret as sounds will always be far less than before. --Cody.Pope 04:01, 20 December 2006 (UTC) Also, sorry about the minor confusion as I didn't read JWSchmidt comment quite close enough. --Cody.Pope 04:07, 20 December 2006 (UTC)

What if the implantation of organ donors' cochleas happened shortly after a person went deaf? For example, the person is stricken with bacterial meningitis and loses his hearing. Can the person recover his hearing by receiving new cochleas shortly after his hearing loss? I'm just curious about the issue of implanting foreign cochleas (like how it compares to receiving a new hand) or what medical constraints prevent us from doing that now. —Erik (talk • contrib) - 05:36, 20 December 2006 (UTC)

I'm not sure, but if you check out the image, I'd say the area is just to delicate to remove. The cochlea is directly connected to the vestibular canals, and if you did anything to them you'd loss your sense of balance. The implant, while somewhat invasive, is just placed in the cochlea. --Cody.Pope 22:12, 20 December 2006 (UTC)

There is some research investigating the ability of new axons to grow into the Organ of Corti; Engraftment and differentiation of embryonic stem cell-derived neural progenitor cells in the cochlear nerve trunk: growth of processes into the organ of Corti, Auditory hair cell explant co-cultures promote the differentiation of stem cells into bipolar neurons. --JWSchmidt 14:30, 20 December 2006 (UTC)

Sauna questions

1) Should I have any doubt bringing a Ipod or a water bottle in the sauna? I keep thinking that it's possible that the humidity or sweat will mess up the inside of the Ipod.

Hrm. I'd advise against it. The humidity might well be an issue. --Brad Beattie (talk) 01:28, 20 December 2006 (UTC)

MattW: I've taken my 30gb 5th Gen ipod video into the sauna several times a week for nearly two years. No problems. I do have some scratches on the face that distract from the image in high ambient light. The sauna is dark, so no problem there.

2) How many calories burn while in the sauna?

3) Also, do calories always burn at a steady pace no matter how long you go (doing the same thing for a long time) or do they burn more and more as you keep burning?

4) AND, how do you change the color of your signature? PitchBlack 01:04, 20 December 2006 (UTC)

Check out the my preferences link at the top right of the page when you're logged in. The signature field is where you want to change things. Try to make sure you respect the signature guidelines when you change things though. --Brad Beattie (talk) 01:28, 20 December 2006 (UTC)

(Edit Conflict)

1) The inside of a sauna is extremely dry, so humidity is very low. The high temperature might not be great for your iPod if you put it down on a hot surface, and your sweat will be bad for it if it gets inside, but if those two things don't happen, the iPod will be able to outlive you in a sauna.

2) Fewer than you would burn at the bus stop. Since a sauna is hotter than your body temp, your body will try to scrub off heat by sweating, opening peripheral blood vessels, and slowing metabolism. You will dehydrate faster, but you will burn calories slower.

3) A given movement/exercise/lifestyle will always burn the same amount of calories (more or less, I know I'm gonna get heckled for that one), however, the energy source your body uses for that exercise will change over time from sugars to fats and protein (I won't get into it...). You can add two 30 min aerobic sessions together and get the equivalent of a one-hour session, if that is what your asking.

4) see Customisation#User_name_and_signatures Tuckerekcut 01:41, 20 December 2006 (UTC)

So, will you have any benefit of burning calories for a long time (about an hour), or will it be the same as if you do 6 10-minute aerobic sessions? PitchBlack 02:39, 20 December 2006 (UTC)

Should be about the same. Tuckerekcut 02:47, 20 December 2006 (UTC)

Don't bring water or iped into sauna. The water can ruin the heating mechanism, and the heat can ruin the music mechanism. Second, don't worry about how many calories you burn. The idea of a sauna is something like 'sweating out toxins', though even this is probably not quite accurate. Vranak 03:27, 20 December 2006 (UTC)

Googling for sauna calories (try it!) suggests a sauna does burn calories at a pretty high rate. Are those search results based on medical studies or are they marketing? You tell me! As to an iPod in a sauna: don't. If you look at the manual of most any electronic device it will specify an operational temperature range, and a sauna is almost certainly way out of that range. Some types of saunas have high moisture ("steam room"), some are dry, so that may or may not kill your iPod too. Weregerbil 13:31, 20 December 2006 (UTC)

empirical formula

how do i get the empirical formula, when given percent composition of a substance :49.3% C, 6.9% H, 43.8% O. i got 4.10 for the ratio of C and cant figure out from there will someone please walk me through,thanks --69.140.210.163 03:35, 20 December 2006 (UTC)

Assuming the percentages refer to weight/mass, you need to convert all three to moles (you've already calculated it for C). You'll end up with decimal places, so multiply them till you get the smallest integers. Clarityfiend 04:54, 20 December 2006 (UTC)

A good way to get to integers here is to divide through by the smallest value. For example if you wind up with 0.12 H, 2.38 C, 5.43 O (just pulling numbers out of thin air) you'd divide each by 0.12. Sockatume 05:18, 20 December 2006 (UTC)

Following on from what the others have said you should get the ratio:

49.3/12 carbon : 6.9/1 hydrogen : 43.8/16 oxygen (the atomic masses of carbon, hydrogen and oxygen are 12,1 and 16 respectively)

4.108c:6.9h:2.7375o = 1.5c :2.52h : 1o (divide by 2.7375)= 3c : 5.04h : 2o

So it's probably C3H5O2 - did that make sense?87.102.4.227 11:43, 20 December 2006 (UTC)

Text Color

In Wikipedia, how do I change the color of the text that I encode? For example, some usernames have different text colors and even different color combinations. How do I do that? I'm creating a userbox and I want to make color combinations on the text. Moonwalkerwiz 04:05, 20 December 2006 (UTC)

Like this? Clarityfiend 04:39, 20 December 2006 (UTC)

Better, like this (or better yet, never mix color information in with the content, and let the CSS stylesheet handle it). —Keenan Pepper 17:03, 20 December 2006 (UTC)

Please don't do that in your signature, though, I hate having to edit a page where most of the text is for the fancy signatures, so I can barely even find the actual content. I don't think anyone over the age of 5 really needs to have a Punky Brewster [1] signature, anyway. StuRat 15:58, 20 December 2006 (UTC)

honey

Can eating a lot of honey be bad for you (other than making you fat)? --Shanedidona 04:46, 20 December 2006 (UTC)

Have you looked under honey --Light current 04:53, 20 December 2006 (UTC)?

I think eating too much of anything can be bad for you, especially something as sugary as honey. --jjron 09:06, 20 December 2006 (UTC)

Typical honey analysis

   * Fructose: 38%
   * Glucose: 31%
   * Sucrose: 1%
   * Water: 17%
   * Other sugars: 9% (maltose, melezitose)
   * Ash: 0.17%

Which sugars? --Light current 09:17, 20 December 2006 (UTC)

I don't see too many complex carbohydrates in there! Or anything else particularly nutritious. --jjron 09:43, 20 December 2006 (UTC)

I have to disagree with some of the misconceptions above. I happen to think that natural-esque sugars (honey, maple syrup, unadulterated fruit juice etc) are fine. You'll stop eating them when your body has had enough. It's stuff like high-fructose corn syrup and refined white sugar that you have to be leary of, as they seem to be added to just about everything made north of Mexico.

Also, the quality of honey makes a big difference. Try to get honey made on a small scale by a small company, not in a generic 10-pound tub at the nearest MegaMart. Vranak 15:36, 20 December 2006 (UTC)

Honey is one of the best forms of sugar, but it's still sugar, so you should limit consumption as much as possible. StuRat 15:53, 20 December 2006 (UTC)

Hmmmm! I thought bees made honey (not companies)--Light current 17:25, 20 December 2006 (UTC)

Think of bees as little cows -- you gotta treat them right for them to produce good honey. Or at least have nice flowers nearby for them to drink nectar from.

Also, limit[ing] consumption as much as possible is not quite what I recommend. If you have a sweet tooth, it's because your body craves sugar. Why would you fight a natural urge? Vranak 23:12, 20 December 2006 (UTC)

Well, just limiting your "natural urges" to food and drink, you would likely eat an extremely unhealthy diet rich in bad fats, bad cholesterol, sugar, salt, excess calories, and other nasties, and totally devoid of vitamins, minerals, fiber, etc., leading to an unhealthy life and an early death. StuRat 21:19, 21 December 2006 (UTC)

Large amounts of sugar consumption can be bad for your teeth. BenC7 01:17, 21 December 2006 (UTC)

This is true. But the healthier you are (and thus the healthier your mouth is), the less sugar troubles your teeth. Vranak

I am skeptical about a different appetite for "natural" sugars versus any other sugars. Do not ASSume that fructose is somehow superior to glucose. Edison 05:52, 21 December 2006 (UTC)

Another potential downside of honey is that it has a relatively high glycemic index:

Sugar      GI
========   ==
honey    - 73
sucrose  - 65
lactose  - 46
fructose - 23 [2]

This means that, relative to other forms of sugar, it rapidly increases your blood sugar level, causing your body to rapidly produce insulin to compensate, resulting in a "sugar crash" later on. So, don't avoid honey completely, but do try to limit your consumption. StuRat 16:26, 23 December 2006 (UTC)

A tangent- in the movie Super Troopers the cops chug maple syrup. Would this cause any damage? -- Sturgeonman 22:37, 27 December 2006 (UTC)

Chemical Reaction

I have a problem with a certain AP Chemistry word problem. I am supposed to turn this into a chemical equation. "A clean iron rod is inserted into a solution of iron (III) sulfate" Would adding more iron simply push the equilibrium further to the products side. Would I wind up with Fe + Fe³⁺ + 3SO₄^2- → Fe₂(SO₄)₃? This problem seems so simple, but it's making me feel so stupid, like I'm missing something extremely obvious. Thanks. Ivan 05:22, 20 December 2006 (UTC)

I suddenly had a thought that it might be redox. Is it? If it is, I'm still stuck. Ivan 05:29, 20 December 2006 (UTC)

The reaction between the iron rod and the iron sulfate solution is indeed redox (note that the net charge is not balanced on the two sides of your equation), but the answer does not require actually using the balanced redox equation for it. Rather, note that the question tells you it's an equilibrium reaction, and consider what kinds of chemical things one includes when talking about an equilibrium. Insoluble solids? Soluble molecules and ions? Gases? Solvents? Catalysts? Etc. DMacks 06:39, 20 December 2006 (UTC)

A study of the relevant redox potentials will tell you that the following redox equilibrium will be established. It is technically reverse disproportionation. The sulphate ions play absolutely no part at all. Fe + 2Fe³⁺ <----> 3Fe²⁺. --G N Frykman 07:24, 20 December 2006 (UTC)

Adding more iron does not change the equilibrium constant, since it is calculated based on the concentration of the chemicals involved in the reaction. Solids have a concentration of 1, so adding more would not change it. BenC7 01:20, 21 December 2006 (UTC)

Evolution question

If evolution is correct, are European people more physically related to monkeys than, say, African people? European people resemble monkeys' pink skin and straight hair... is it fair to assume then that black people are in more advanced stages of human evolution, because they don't physically resemble monkeys? They don't have the skin and hair of monkeys. So what now? I'm not an expert on this field... so tell me. PS: I don't think I've ever seen a monkey with black skin. ► Adriaan90 ( Talk ♥ Contribs ) ♪♫ 06:32, 20 December 2006 (UTC)

If evolution is correct? No, human beings are all the same species, certain races are not more or less related to other primates. Variations in skin tone and hair colour and texture are adaptations only tens of thousands of years old which occurred in response to environmental differences. Anchoress 06:37, 20 December 2006 (UTC)

Human skin color might be of interest. —Erik (talk • contrib) - 06:38, 20 December 2006 (UTC)

Look in the face of a Gorilla! Its black! He is related to me to the same degree than to African people, because we all come from a small group of people who lived in east Africa millions of years ago. To use the skin colour as marker for evolution has a long tradition, and caused some of the awful theories of Herrenrasse and other ideas which made alot of people suffer.--Stone 08:31, 20 December 2006 (UTC)

According to the most widely held views of scientists, all modern humans are descended from a small group of people living in Eastern Africa some time in the last 200,000 years. The article on Mitochondrial Eve may be of interest to you. As the others have said, no human group is more or less related to apes or monkeys than any other group - we are all equally related to the same common ancestors as apes such as chimps and gorillas some time in the last 5 - 8 million years. (Incidentally, this group split from monkeys much earlier. Contrary to repeated use in popular culture, chimpanzees are apes, not monkeys.) Skin colour is a lousy determinant of anything; in some human groups it is thought skin colour is controlled by as little as a single gene. Hair also tells you little - my mum has curly hair, my sister and brother have wavy hair, I have straight hair, we all have dark hair but my other sister has straight blonde hair; ultimately, so what? Which of us is more like a monkey? --jjron 09:01, 20 December 2006 (UTC)

I believe that primates, and mammals in general, typically have either black skin or pink skin. Pink is more typical under fur, with black being more common in areas exposed to light, such as lips, noses, finger/toe pads, etc. Straight hair/fur is also far more common in mammals than curly hair. StuRat 15:49, 20 December 2006 (UTC)

Based on skin colour, I'd think that maybe European people are more related to domestic pigs, and African people to Wild Boars.  --Lambiam^Talk 16:07, 20 December 2006 (UTC)

People don't evolve from monkeys. Rather people and monkeys evolve from a common ancestor. From an evolutionary viewpoint I think it is fair to say that Europeans, Africans and monkeys are equivalently advanced as a species with their own adaptations and traits.

Cool, thanks. ► Adriaan90 ( Talk ♥ Contribs ) ♪♫ 06:03, 21 December 2006 (UTC)

A bit late but bear in mind Race is a contentious issue in science anyway. Not all scientists feel it's a meaningful concept Nil Einne 10:57, 21 December 2006 (UTC)

Melanin deposition in the integument is a highly paraphyletic trait and has no bearing on evolutionary relationship. See also Gloger's Rule for the probable adaptive value of light vs dark skin in humans... the main reason seems to be weighing the benefits of absorbing UV rays deep into the skin (which will help building certain vitamins) vs blocking them with melanin (which will decrease skin cancer rates). Dysmorodrepanis 04:09, 28 December 2006 (UTC)

lysergic acid diethylamide

given determination and a basic understanding of organic chemistry (college course), would it be in the realm of possibility to synthesize this with obtainable chemicals using obtainable glassware and lab equipment? i ask this as a fan of the substance, and as someone with an interest in chemistry. i figure i would be enjoying myself with the process, but also gaining something useful.

Why not take a trip to LSD?--Light current 09:28, 20 December 2006 (UTC)

The sythesis of LSD from readily obtainable chemicals and glassware would be a difficult undertaking. I doubt that it could be accomplished by anyone without graduate-level experience in organic synthesis and lots of money. In the lab LSD is instead made easily from lysergic acid which is isolated from ergot fungus and not something that just anyone can go out and buy. --Ed (Edgar181) 15:14, 20 December 2006 (UTC)

A professor of mine told the class I was in that some dude who passed General with a D (Federal-style grade) was able to get far enough to get 20 years. I don't know if that helps any... 68.39.174.238 21:43, 28 December 2006 (UTC)

No-op microprocessors

As all microprocessor instructions finally boils down to 0/1 through output pins. This means that we can build a microprocessor that does nothing but just generates 0/1 through output pins, in a desired way. Functionalities can be built on the top of such microprocessors. Such processors would be very much simple (?) to build. Do we already have any thing like this? V4vijayakumar 09:59, 20 December 2006 (UTC)

See Programmable logic array. Also ROMS serve in such a capacity as well as its many, many variations. Essentially you put an address in and get the desired data out.Adaptron 10:39, 20 December 2006 (UTC)

DSP digital signal processor might be of interest as well. Very specialised digital circuits may fit the bill - eg a chip that decodes Mpeg audio to pcm - need no instructions (though note in this case 'instructions of a sort' are built into the compressed data)- sorry I don't know enough to give you a specific example.

I very very simple example of what you describe would be a logic gate on a chip an example of this is 7400 series. (Good question in my opinion by the way)87.102.4.227 12:31, 20 December 2006 (UTC)

Look up Microsequencer and Microcode and Bit slicing. Back in the mainframe days, microprocessors were built up from very simple parts; far simpler than a microprocessor chip. Inside of each complicated machine language instruction, the microsequencer would be executing several simple instructions in microcode. Even today, some hobbyists use these concepts when building their own computers from logic chips, or from AND gates, or even from individual transistors. --Wjbeaty 03:37, 21 December 2006 (UTC)

ASICs I think is what you are looking for. Microprocessors derived from ASICs. Microprocessors derived from ASIC requirements for multiple digital watches. Rather than create different chips for each watch product, they designed a single chip that did the basics (fetch, decode, shift/add, store) and could be put in mulitple products with a ROM of instructions to implement the specific function. --Tbeatty 03:20, 21 December 2006 (UTC)

owner/investor model

In terms of economics or business science I know there is an ownership/investor model in which only management and labor, i.e., the employees are the owner/investors and that this model of ownership/investment is highly successful but is there also a model to replace conventional non-profit foundations in which contributors for instance to the Wikipedia can benefit financially as well? Adaptron 10:37, 20 December 2006 (UTC)

A project with a model similar to what you're proposing is used in microloans. StuRat 15:41, 20 December 2006 (UTC)

Not really. microloans suggest financial assistance. The model I am looking for is directed not at assistance but at just compensations for services contributed voluntarily but with a sence of obligation for intellectual, social or other esoteric reasons more so than personal financial gains. Kind of like when mom bakes you some cookies not for any financial reward or compemsation but becasue she loves you and so you take out the trash not because you get an allowance but becasue you love her. Adaptron 18:02, 20 December 2006 (UTC)

I think you might misunderstand the purpose of microloans, which is twofold:

1) Lending money to help people, and the community, by giving them "seed money" to start or expand a small business.

2) To make a profit from interest paid on the loans.

Thus, it's not entirely a charity or entirely a business, but a bit of both. StuRat 03:08, 21 December 2006 (UTC)

You might also be interested in communes, where each person is expected to contribute in a different, non-financial, way. StuRat 03:11, 21 December 2006 (UTC)

Ions affecting Rheumatoid Arthritis

Good day,

I am looking for any documented research regarding the subject of ions affecting Rheumatoid Arthritis. My dad is 56 and has suffered from this disabling disease for over 30 years. Rheumatoid Arthritis is the inflammation of tissue. He experiences severe joint and muscle pain, fatigue, and other common related symptoms. He suffers excruciating pain with little-no relief. His condition has worsened substantially and his joints have gradually become grotesquely deformed. Although there is currently no conclusive 'cause or cure', he is adamant that ions affect his disease. He experiences severe attacks before thunderstorms or whether changes. We live in South Africa and are exposed to climate changes such as thunderstorms and cold fronts. Is there any documented literature relating to how and why ions affect Rheumatoid Arthritis, and how this can be prevented?

I sincerely appreciate your help.

Regards, Claudie FreemanClaudie33 11:54, 20 December 2006 (UTC)

I believe that storms do affect rheumatoid arthritis, but not because of "ions", the air pressure changes common in storms (typically a rapid air pressure drop) cause the inflamed membranes to swell to equalize the pressure, which can be quite painful. This suggest that one treatment would be a hyperbaric chamber, where the pressure could be slowly increased and kept at a high level. Unfortunately, once removed from the chamber, his symptoms would return, and quite possibly be worse than before. Thus, this isn't a good treatment, after all. StuRat 15:07, 20 December 2006 (UTC)

There is a fairly small body of rigorous scientific study of potential links between arthritis pain and changes in the weather. Nevertheless, if you search PubMed using a search term like arthritis AND barometric pressure then you will hit some studies. Some papers suggest no statistically significant correlation [3], while others find a weak correlation [4], [5].

For studies that found a statistically significant correlation, increased pain tended to associated with lower temperatures, high humidity, and/or falling barometric pressure. Note that these conditions tend to be common right before thunderstorms. The mechanism which ties these factors to an increase in arthritis pain are not well understood; the explanation provided by StuRat above has been proposed as one possibility. TenOfAllTrades(talk) 15:13, 20 December 2006 (UTC)

Additionally, cold can worsen the condition and should be avoided. The living human body is full of ions, and the influence of the weather on that is completely negligeable. Some discussion of the effect of the weather: [6], [7], [8].  --Lambiam^Talk 15:20, 20 December 2006 (UTC)

In humans there seems to be not one, but various meteorological factors that alter pain perception (as opposed to arthritis as such), but these have not been defined. Whatever the cause, one would expect your dad's doctor to institute effective pain management. --Seejyb 23:59, 20 December 2006 (UTC)

Is my daughter being poisoned?

My children have never been sickly. But in the last nine months both have had severe illnesses!!! My daughter who is 12 years old is scheduled for a colonoscopy and an endoscope this friday. Is this normal for someone so young? In march of this year my 15 year old son had headaches so severe he was getting paralized on his right side with each worsoning headache. He had all the major tests done, ie, MRI, CAT Scans, Spinal Tap, Blood work...etc. but in the end NOTHING!!!! His symtoms stopped withing two weeks of me arriving where they live. About six weeks later, my daughters symtioms started. Her symtoms don't include headaches though. She is having trouble eating and drinking anything!!! She has been very ill!!! Then someone pointed out that maybe it's not my children, but their stepmom. I don't want to jump to any conclusions, but this is my children I'm talking about and I'm at a loss here!!!!! I always thought she was great with my children, but she has done everything she could to keep me from even knowing about my children's illnesses, and I'm still in the dark about almost everything!! The childrens father seems to be no help whatsoever, so that isn't an option. Any suggestions or symtoms of poisonings that match would be greatly appreciated!!!

Thank You from the bottom of my heart!!!!

Kristie L. Hawkes concerned Mom

We are not able to help with medical diagnosis. Please seek medical attention. If you are unsatisifed with your current doctors, seek second opinions. Hipocrite - «Talk» 13:03, 20 December 2006 (UTC)

You should in any case discuss your fears with the doctors treating your children.  --Lambiam^Talk 14:49, 20 December 2006 (UTC)

Might be psycological. From what you have said this is far to serious to expect reliable help here in Wiki. Find a competant mental health counsellor. I would suggest getting HFS involved, but sometimes getting them into your life can be a Trojan Horse.

When the above poster said psychological, h/she meant for your children, not you. --68.149.31.252 09:34, 21 December 2006 (UTC)

Agreed, have them specifically test for common poisons. I don't know how you can bring this up with your children in a subtle way, but perhaps you could say "Don't ever eat or drink anything that tastes even the least bit 'funny', as it may have gone bad or be contaminated". The idea here is to get them to be cautious without making unproven accusations of poisoning that could destroy your family. StuRat 15:03, 20 December 2006 (UTC)

Regrettably, this is not the forum for making diagnoses, even if we could help. Vranak 15:33, 20 December 2006 (UTC)

As long as you understand that medical advice here may be worth what you pay for it, I will give you some. Intentional poisoning seems far less likely than many other explanations. There have been very few cases of parents or stepparents giving a chronic poison (chronic means over a long period of time) to two children except in the context of Munchausen by proxy syndrome, and this sort of thing has a very distinct flavor: the parent is driving the medical evaluations and simply moves on to another doctor when the doctor is unwilling to "play" any more. It would take two different poisons to produce such disparate responses; how likely is an adult to choose two different ones? To produce what result and for what motive? It would also mean that your previous assessment of her as a caring parent was in error, and I would tend to trust that assessment. I would drop that line. I would not recommend questioning your children about funny tasting things: it would not confirm or refute your suspicion and it will be disturbing to them (either about you or her) if they understsnd what you are getting at.

Finally, there are far more common explanations for the symptoms you mentioned. Headaches with transient one-sided weakness and a negative workup is a recognized migraine variant, and there are no tests that will be positive. You havent told us why your daughter "is having trouble eating and drinking anything" --- whether that is because of pain, or vomiting, or fear of something like choking or fatness, or because someone is trying to make her do so. For unexplained gastrointestinal symptoms that persist, sooner or later a doctor will offer endoscopy. It is what gastroenterologists do. Good luck. alteripse 22:16, 20 December 2006 (UTC)

If not intentional, are you sure it's not something environmental? Sometimes mold allergy for example can get very severe if the mold is toxic. It is an invisible deadly killer and difficult to diagnose. Mold can be very difficult to find, such as a leaking bathtub affecting a bedroom wall behind cupboards. Your house may have to be tested for toxins especially mold. Sandman30s 14:06, 21 December 2006 (UTC)

To Refreeze.. Or not to Refreeze

Why is it considered so bad to refreeze meat products?

Micro-organisms survive the freezing process, and multiply upon thawing. Their colonisation and digestion activities are made easier by the microscopic tears that occur in frozen meat due to the formation of ice crystals. Re-freezing just puts these new micro-organism colonies in cold storage, waiting to again multiply upon defrosting, and the degradation of the meat fibres due to ice crystals repeats upon the second freeze. And finally, the meat decomposes faster after freezing due to the previously-mentioned factors, decreasing the quality of the meat. Anchoress 16:30, 20 December 2006 (UTC)

But to "save" the meat, one can cook it thoroughly and freeze the prepared dish. --Seejyb 11:23, 21 December 2006 (UTC)

Although if you're not going to cook it within a day or so and you're not going to throw it away, I would suggest refreezing is better then leaving it in the fridge. Nil Einne 11:39, 22 December 2006 (UTC)

Random Question

Ok sorry for the mad random question but I thinik its necessary to get an answer. Anywayz, my gf and I are planning on having a serious romp tommorrow and I want to be more than prepared. Is there a way to increase the amount of semen I produce, or is there not a way to do anything. Thanks, yo, I'll be coming back later. Peace.—Preceding unsigned comment added by LukeHughes (talk • contribs) 16:33, 20 December 2006

Semen production is relatively constant, I think. One obvious way is to conserve it ahead of time by not ejaculating for a while. Friday (talk) 16:42, 20 December 2006 (UTC)

According to the manual, masturbating until you are close to ejaculation a few hours before intercourse does the trick. I'm not sure how increased output will make you "more than prepared", though. yandman 16:51, 20 December 2006 (UTC)

It would if pregnancy is the goal. Anchoress 16:57, 20 December 2006 (UTC)

Producing more semen does not automatically mean producing more sperm. Friday (talk) 17:01, 20 December 2006 (UTC)

Eat lots of protein and don't ejaculate until then. StuRat 17:24, 20 December 2006 (UTC)

As most people think 'beef or chicken' when the word protein is used, I would remind you that dishes containing lentils, rice, beans, nuts, seafood and so on are excellent sources of protein that no one suspects as having any negative long-term effects.

Also, auto-stimulation sans release may help, as Yandman suggested. Regardless, the main thing is to enjoy yourself, and not get all caught up in volumetric analysis. If your girlfriend is doing her part, such considerations are needless. Vranak 17:39, 20 December 2006 (UTC)

And drink plenty of fluids too. And if you want to go that way, stimulate your prostate, not producing more sperm but more seminal fluid.

Well what you want to do is up to you, but unless you've both recently been checked for STDs and are in a commited relationship and pregnancy is the goal I would suggest the amount of semen you produce is unimportant since it should all end up in the condom/s you use. At the very least, I hope you've considered birth control... Nil Einne 10:52, 21 December 2006 (UTC)

Where is the origin/homeland of the Mongol (Chinese) race?

H.G. Wells in his outline of history suggests that Chinese civilization has a different origin from the rest of the world. What was the route of the Chinese race from their origins most likely in Africa to their current position today? For example the homeland of the Caucasian race has been suggested in Tibet, India, Iran and of course the Caucaus, I'm not aware of any theories for the Mongoloids. I would really appreciate a geographical trace from their origins to the present. How and where did the Mongoloids begin diferentiating from the human common ancestor? I've heard theories of them evolving from both caucausiod and negroid sources as well as theories of independent evolution. --Maddoz 17:37, 20 December 2006 (UTC)

The recent single-origin hypothesis suggests we all evolved in Africa and then spread across the globe. --Cody.Pope 20:56, 20 December 2006 (UTC)

Alternatively Multiregional hypothesis gives a slightly different view suggesting that homo erectus and homo sapiens are the same species and local populations or 'races' have come about by "selection, mutation, genetic drift, and gene flow." (from the article)

and Hybrid-origin hypothesis emphasises two (or more) distinct 'species' of human that had evolved separately: "..all of the genetic variation between the contemporary human races is attributable to genetic inheritance from at least two widely divergent hominid species, or subspecies, that were geographically dispersed throughout ... prior to the evolution of modern Homo sapiens sapiens"87.102.4.227 21:15, 20 December 2006 (UTC)

So that's the background - I too would be interested in an answer..87.102.4.227

Multi-origin for biological evolution of humans is all but dead. Multi-origin for cultural evolution in general is well verified, with stuff like writing and agriculture being developed independently all over the world. The East Asian peoples apparently originated in (duh) Eastern Asia, basically the Chinese/Mongolia area. What you have today is simply the part of that ancestral population that remained there and build up their culture in situ, rather than moving about like the Asian nomad peoples who developed a very different kind of culture and took it far and wide into Europe even. The "mongoloid" phenotype evolved over a long time; see for example the question whether the Xiongnu were the ancestors of the Huns. From the little information that can be gleaned from antique sources, it seems that 2500 years ago, the steppes nomads of that time (which had largely mongoloid ancestry) appear to have been a bit less "chinese"-looking than for example the Mongols 2000 years later. Dysmorodrepanis 04:18, 28 December 2006 (UTC)

LD50

Does anyone know of a good database for various LD50s? My usual database is ok, but it's a bit dated--74.66.242.190 18:06, 20 December 2006 (UTC)

B12

Around what peak wavelength is the Soret band for vitamin B12? Does it have one?? Just curious since it looks so much like a heme--74.66.242.190 18:39, 20 December 2006 (UTC)

Even if it doesn't have a Soret band, doesn't it at least have a strong absorption band in the visible/near visible range? Any response would be appreciated--74.66.242.190 13:47, 21 December 2006 (UTC)

weight

if a bag of cotton and iron bar reads 100gmsin a weighing machine . in reality which is heavier?why? (i think its got something to do with uptrust) answer before 21st december2006,10pm

This almost sounds like a homework question. Our articles on weight and mass be helpful. Friday (talk) 19:57, 20 December 2006 (UTC)

This is a variation on a classic brain teaser. The U.S. version goes something like this: "Which is heavier, a pound of feathers or a pound of lead?" Googling will most assuredly give you more info than you'll ever need. The key question is - what do you mean by "heavier"? -- 21:28, 20 December 2006 (UTC)

See also Buoyancy and Weighing scale.  --Lambiam^Talk 09:04, 21 December 2006 (UTC)

I prefer "which is heavier, a 16 ounces of feathers or 16 ounces of gold ?", as that brings into play the fact that most things are measured in avoirdupois weight, but precious metals are measured in troy weight. StuRat 01:15, 21 December 2006 (UTC)

That doesn't work, because only an idiot uses ounces for feathers :-P Nil Einne 10:47, 21 December 2006 (UTC)

Are you using the snow leopard def of "ounce" ? StuRat 22:08, 21 December 2006 (UTC)

Matter

Given the exchange and dispersion of matter, how likely is it/how often do we inhale/consume and/or incorporate into our own protein structure molecules that were once in some historical figure, say Abraham Lincoln? 216.130.233.77 22:46, 20 December 2006 (UTC)

The probability that molecules have been incorporated is pretty low; after we die, our complex macromolecules tend to get digested. The food that we eat comes from plants (which survive pretty much on water and carbon dioxide) or from animals that ate plants. So there's little likelihood that whole biomolecules made it through. (It is possible that you're breathing some of Lincoln's oxygen or drinking some of his water, though.)

If we just look at atoms, we can take a rough guess. Figure you weigh about sixty kilograms and that about a third of that is carbon. That works out to about 1500 moles of carbon atoms. (Obviously, you're made of other atoms, but this is just back-of-the-envelope.) Roughly speaking, that's about 10²⁷ atoms.

Let's see here—there's about 1900 gigatons of carbon in the biosphere (see carbon cycle for more info). Figure that about 1% of the total available carbon (we include water-dissolved carbon dioxide, surface carbonate deposits, and atmospheric carbon dioxide and carbon compounds) is in the biosphere at any given time; that gives us a total of about 10⁴³ carbon atoms from which living things might be made.

So, about one carbon atom out of every available 10¹⁶ is incorporated into your body. To make a Lincoln takes about 10²⁷ carbon atoms; yeah—the odds are pretty good that some of those are common. (Your odds get even better if we choose to look at all the atoms of the body, and if we count all the atoms that you've consumed, excreted, inhaled, or exhaled over your lifetime.) TenOfAllTrades(talk) 23:16, 20 December 2006 (UTC)

John Allen Paulos briefly mentions this sort of thing in his book Innumeracy. According to him, the probability that you just breathed a molecule exhaled by Julius Caeser's last breath is over 90%! The argument is similar to the one given by TenOfAllTrades. — Kieff 00:29, 21 December 2006 (UTC)

Here's a passage from A short history of nearly everything:

We are each so atomically numerous and so vigorously recycled at death that a significant number of our atoms—up to a billion for each of us, it has been suggested—probably once belonged to Shakespeare. A billion more each came from Buddha and Genghis Khan and Beethoven, and any other historical figure you care to name. (The personages have to be historical, apparently, as it takes the atoms some decades to become thoroughly redistributed; however much you may wish it, you are not yet one with Elvis Presley.)

Lincoln was born much later than these people, so I would guess we all have ten million of his atoms. Of course, people who live close to where Lincoln lived have many more of his atoms than someone from China. --Bowlhover 00:34, 21 December 2006 (UTC)

"We are all made of star dust...or dinosaur crap...it all depends on how you choose to look at things." StuRat 01:07, 21 December 2006 (UTC)

Good point, Stu. I'd say dinosaur crap is mostly made of star dust :) Dr_Dima.

I'd like to take this opportunity to point out the difference between atoms and molecules. Although you're most assuredly going to have some of the atoms of any given historic person, it's doubtful you'll have any of the molecules. Even simple molecules like water and oxygen get rearranged. In biological systems water is broken apart routinely in the synthesis and destruction of biological molecules. Even in a "inert" glass of water, water molecules are feverishly exchanging hydrogens. Oxygen molecules are split up upon respiration and combustion, and then reformed with different partners in photosynthesis. Even nitrogen molecules get broken and reformed during nitrogen fixation and denitrification. So atoms are reused, but molecules, even simple ones, are not. -- 17:35, 21 December 2006 (UTC)