Wikipedia:Reference desk/Archives/Science/2011 June 23

= June 23 =

trap
what kinda glue is in mice and insect glue traps  — Preceding unsigned comment added by Tck350 (talk • contribs) 00:01, 23 June 2011 (UTC)


 * In Mouse traps, the glues are mentioned but not specified. In Glue, there is 200,000 years of history, but no mention of rodents. I will hazard a guess that they are Pressure-sensitive adhesives, but defer to the experts. 70.177.189.205 (talk) 01:12, 23 June 2011 (UTC)


 * They would need to have an oil-based glue, not a water-based glue, as those would just dry out in a few hours or days. I'd also like to buy a vat of the stuff, so I can make my own mouse and insect traps. StuRat (talk) 01:55, 23 June 2011 (UTC)


 * Isn't there a petroleum derived gum used as the basis in modern chewing gum? Plasmic Physics (talk) 14:37, 23 June 2011 (UTC)


 * The article on gum base describes this, and alas, it appears so - paraffin, microcrystalline wax, even potentially hazardous vinyl acetate. As with so many food products, as discussed in chewing gum, the composition becomes healthier and more sophisticated the further one looks back in time - chicle a few centuries ago, mastic gum in Eurasia in the time of Dioscorides, and a potentially therapeutic birch bark tar in Neolithic times.  But now people can only afford to eat oil. Wnt (talk) 19:51, 24 June 2011 (UTC)


 * A 1949 book I have ("Money-Making Formulas") says for fly-paper, 5 to 7 parts boiled linseed oil, 2 to 3 parts gum thus and 3 to 7 parts of non-drying oil. It suggests cotton-seed, castor or neatsfoot oil will suffice.  "Gum thus" is Frankincense.  The book gives another recipe as 8 parts resin, 4 parts rape-seed oil and 1 part honey.  Melt it all together and apply to paper. --TrogWoolley (talk) 18:45, 25 June 2011 (UTC)

Hessdalen lights -- a legit phenomena or a lot of bogus claims?
The Hessdalen Lights article does not inspire a lot of confidence, neither does the Project Hessdalen webpage with an image gallery featuring pictures mostly from the early 80s despite there apparently being an automatic monitoring station in place for a decade. Are these lights confirmed to be a regular, natural phenomenon by a real scientific authority, or are they just the usual run of the mill paranormal BS? The Masked Booby (talk) 00:50, 23 June 2011 (UTC)


 * As an example of the latter (real, documented phenomenon) we have the Green Flash, with a short but very clear and well-documented article... The Masked Booby (talk) 00:52, 23 June 2011 (UTC)


 * It doesn't sound like a convincing scientific explanation has been found yet, but that's not the fault of the article. Do you doubt that the lights exist ?  Or do you not think there shouldn't be a Wikipedia article on it ? StuRat (talk) 01:52, 23 June 2011 (UTC)


 * Reminds me of Chir Batti - manya (talk) 03:22, 23 June 2011 (UTC)

Spheres and Disks (and Disks to Jets?)
Any simple answers as to why (presuming from my Discovery Channel education) collapsing stars, black holes, etc. (spheres) seem to evolve into or gain Disk shaped phenomena. I am guessing that this will relate to planets that can evolve rings, and why solar system orbits tend to be on a plane as well. To me a balanced spherical object would have spherical phenomena not disk shaped processes forming from it. I will hazard a guess that this 3 to 2 dimensional process is at work when pulsar jets and such, take the process to the next level. Bonus points for cool links. 70.177.189.205 (talk) 00:51, 23 June 2011 (UTC)
 * A balanced spherical object would have spherical phenomena if it were not rotating, but most things in the universe rotate. It's natural for rotating systems to produce disk-like phenomena.--Srleffler (talk) 01:06, 23 June 2011 (UTC)
 * Which led me to this, thanks. 70.177.189.205 (talk) 01:42, 23 June 2011 (UTC)

Bumps on tongue
''Removed request for medical advice. Question required diagnosis of problem and prognosis of possible healing of the problem.'' -- k a i n a w &trade; 03:28, 23 June 2011 (UTC)

Marijuana and chickens
If a chicken was fed a diet with some quantity of marijuana, would THC be excreted in the eggs in an amount detectable by a person eating those eggs? 68.231.149.156 (talk) 05:32, 23 June 2011 (UTC)


 * Ignoring the ethical considerations, I very much doubt it. Humans, at least, metabolise and excrete it. --129.215.47.59 (talk) 10:13, 23 June 2011 (UTC)

Fully charged and partially charged battery cells working together
I've read that you shouldn't have partially charged and new (or fully charged) batteries together. Does that apply only if they're in series or does it apply to parallel configurations too? --129.215.47.59 (talk) 10:11, 23 June 2011 (UTC)
 * Parallel could possibly be worse, since they are probably operating at different voltages, and this will put a lot of strain on the good battery. All this depends on what kind of batteries you are talking about. &mdash;Akrabbimtalk 12:15, 23 June 2011 (UTC)


 * I experimented with standard AA batteries when I was a kid (for a science project) and found that if you drain a battery, it just stops working. If you force electricity through it by putting it in series with another battery, it will start to produce a little electricity (not much, but measurable) and then it will start to leak battery acid through the cardboard wrapping. So, my conclusion was that the reason you don't mix batteries is to avoid battery leakage. If they are in parallel, you will likely still get the same problem because there will be current flowing through the dead battery. I have no idea if this applies in any way to non-alkaline batteries. -- k a i n a w &trade; 12:22, 23 June 2011 (UTC)
 * Don't connect a new (or fully charged) battery and an old (or discharged) battery in parallel. There is no particular problem in connecting them in series except that the old (or discharged) battery will cause the two to have a lower voltage than you were planning.  Dolphin  ( t ) 12:29, 23 June 2011 (UTC)


 * If you connect a good battery and a dead battery in parallel, the good battery will attempt to recharge the dead one. The results vary depending on battery chemistry. --Carnildo (talk) 00:21, 24 June 2011 (UTC)


 * Some older programmable calculators and personal organizers have two kind of batteries in it: normal ones and a backup one that's only used so that the device does not forget the data in their memory while you replace the normal batteries. These backup batteries thus drain very slow and are typically intended to last for the whole life-time of the device.  (These days the data is instead saved to flash or solid state memory instead, but that of course wasn't yet available cheaply when these devices were made.)  If you shouldn't mix new and old batteries, how do these devices work?  &#x2013; b_jonas 13:54, 24 June 2011 (UTC)


 * There are various ways of isolating one battery from another. The simplest I can think of is to have the main batteries hold a relay in one position; disconnecting or discharging the main batteries will cause the relay to switch to the backup battery.  There are other circuits that give the same effect, with varying degrees of sophistication and reliability. --Carnildo (talk) 00:14, 25 June 2011 (UTC)

gene difference between Man, Woman, Chimpanzee?
I just watched a video about a Chimpanzee use a frog's mouth for masturbation. This really shocked me... Then a question came into my mind:genetically speaking, my gene is more similar with a male Chimpanzee than any woman in the world?(provided that woman has no Y chromosome)Nilman (talk) 17:03, 23 June 2011 (UTC)


 * You can't really talk about the genetic difference between males and females of the same species versus males and females of another species, I don't think. Homo sapiens is considered a single species for the purposes of figuring out genetic distance from other animals. So I think it's pretty clear the answer is "no". --Mr.98 (talk) 17:19, 23 June 2011 (UTC)


 * I am not an expert, but presumably there would be no problem with just feeding the data for males only, or the data for females only, in the relevant algorithms and proceed as one would do for computing the genetic difference between species that do not have genetic sex differences. In fact, I would expect that that's the basic algorithms, and that any special treatment for the sexes (if it exists at all) is an add-on. Hans Adler 17:51, 23 June 2011 (UTC)


 * Right, but I don't think it would be any different than the species-to-species comparison. --Mr.98 (talk) 18:08, 23 June 2011 (UTC)


 * I think I see where you're coming from. You think that since only males have the Y chromosome, that therefore that genetic portion is unique to males, so 1 of the 46 total chromosomes, or 1/46, or over 2%, should be different, which, indeed, would make that difference about the same as that between humans and chimps.  The flaw in that theory is that many of the genes on the Y chromosome are duplicates of those on the X chromosome, so aren't unique to males. StuRat (talk) 18:44, 23 June 2011 (UTC)
 * Note that counting chromosomes is a flawed approach. In this case, the Y chromosome is small compared to the X chromosome. In the case of humans it is only about 58 million base pairs (compared to 153 million for the X chromosome or 3 billion for the human genome) and more importantly only has 86 currently recognised genes (compared to 2000 for the X chromosome and 20000 to 25000 for the human genome). BTW the Pseudoautosomal regions don't really have that many genes (only 29 have been identified so far). Nil Einne (talk) 00:42, 24 June 2011 (UTC)

Thank you. I'm not familiar with genetics.Nilman (talk) 05:42, 24 June 2011 (UTC)

Great Lakes Storm of 1913
Hallo, as a German Wikipedian who ocasionally translates articles from the English Wikipedia I came over that article and am wondering about the a good part of that section. As a given wind direction normally means the way from which the wind blows the given data
 * The intense counterclockwise rotation of the low was made apparent by the changing wind directions around its center. In Buffalo, New York, morning northwest winds had shifted to northeast by noon and were blowing southeast by 5:00 p.m., with the fastest gusts, 80 mph (130 km/h), occurring between 1:00 p.m. and 2:00 p.m. Just 180 miles (290 km) to the southwest, in Cleveland, winds remained northwest during the day, shifting to the west by 5:00 p.m., and maintaining speeds of more than 50 mph (80 km/h).

seem to be incorrect. If we take this as a cartesian coordinates system then it seems wrongly that in Cleveland the north moving counter clockwise rotating low produces northwesterly winds the whole day what suggests that Pittsburg, OH the whole day low within the IIIrd quadrant while Buffalo initially was in the same quadrant, later in the second and after that in the first quadrant. What of course does not make it a counterclockwise rotation.

Maybe I just don't get it, maybe the article was vandalized some time back or some editor accidentally could not keep east and west from each other. The author who wrote the most part of the article appearantly isn't active regularily anymore so asking him seems not to be an option at this moment. Any thoughts? --Matthiasb (talk) 17:39, 23 June 2011 (UTC)
 * It makes sense to me. Surface charts from the 8th through the 10th show that the storm dug south into the Appalachians, ending up south and slightly east of Buffalo, which explains the northwest winds, and the shift to NE as the storm retrograded back NW to a position just northwest of Buffalo (source). Once there, it produced the southeast winds, which were as severe as they were due to the close proximity to the low-level circulation center. In the meantime, however, Cleveland remained on the western side of the storm, which is consistent with an extended period of northwest winds. Juliancolton (talk) 18:03, 23 June 2011 (UTC)
 * That was the missing item, the resulting blizzard. Thanks Julian, now it makes sense to me as well. --Matthiasb (talk) 19:25, 23 June 2011 (UTC)
 * I can't open that link but the fact that there was a blizzard doesn't say anything about wind direction. What information does that .djvu contain? Rmhermen (talk) 17:34, 24 June 2011 (UTC)
 * Me either, I don't have a .djvu-reader on my weekend machine. But the point is that in deed there were two converging systems, one frontal near or over the Upper Peninsula and another cyclonic which developped somewhere further south near Washington or over Virginia. The latter wandered to the north. For some time Buffalo still experienced the northwest winds form the (let's call it) U.P. system, later came under influence of the (say) D.C. low, first in its second quadrant meaning it experiencs north eastern winds. When the low level center moved near Buffalo on the West, Buffalo shifted to the first quadrant, lying right of the center, so got south eastern winds. The D.C. low moved further to the North and finally its third quadrant got in phase with the NW winds of the U.P. system, meaning that the rotating winds of the D.C. low increased the winds of the U.P. low and things got worse. As Julian said, Cleveland stayed on the west of the D.C. low the entire time and never came directly into influence of the D.C. low. My earlier mistake was that I presumed wrongly that there was only one low, the rotating swirl of the D.C. low. --Matthiasb (talk) 18:03, 24 June 2011 (UTC)

Neurons Attached
How are the neurons (cells) attached to the rest of the brain matter? Are the neurons completely hidden inside the actual brain, like it gives a cover to the neurons and synapses? — Preceding unsigned comment added by 70.136.159.57 (talk) 18:46, 23 June 2011 (UTC)


 * I just checked the wikipedia article on brain, and it seeems the human brain is made up of roughly equal amounts of two kinds of cells, neurons and glia. thx1138 (talk) 20:21, 23 June 2011 (UTC)

How are these cells, neuron, and glia attached to the actual brain matter? I know the synapses and cells are connected almost like a wire, but what about the actual brain itself, or the brain tissue? — Preceding unsigned comment added by 71.143.159.249 (talk) 20:56, 23 June 2011 (UTC)


 * You are not listening; brain matter is neurons and glia. Plasmic Physics (talk) 22:10, 23 June 2011 (UTC)


 * Smi32neuron.jpg think the OP is just having trouble conceptualizing what the brain matter looks like. As the other responses have indicated, the neurons and glial cells are the principal cellular components of brain matter, and they are surrounded by their own cellular processes (axons and dendrites) and encased in extracellular matrix.  All of the material surrounding the cell bodies is called the neuropil.  The articles on neurons and glia have pictures that show the histology of the nervous system (one example shown to the right).  In this picture, the darkly stained cells are pyramidal neurons, and you can see how extensive their cellular processes are.  All of the lightly stained material is the extracellular matrix, kind of like the glue that sticks everything together.  For a more detailed look at neurohistology, you could try this external site hosted by the University of Minnesota. --- Medical geneticist (talk) 22:35, 23 June 2011 (UTC)
 * Are axons and dendrites part of the neurons themselves, or is my understanding incorrect? thx1138 (talk) 16:48, 24 June 2011 (UTC)
 * Please note that the SMI-32 monoclonal antibody does not stain every neuron, but subsets. Staining all neurons would make the structure of any one of them difficult to make out.  Golgi's method was an important advance which overcame this by some still rather mysterious photographic process. Wnt (talk) 19:34, 24 June 2011 (UTC)

Polonium in cigarettes
According to this article, the average cigarette contains .04 picocuries of Polonium-210. Po-210 has a half life of 138.376 days. How long would one have to store cigarettes in order to have them decay to essentially negligible (from a health and/or physical point of view) levels of Po-210? --Mr.98 (talk) 19:56, 23 June 2011 (UTC)
 * It's not necessarily safe to assume that, just because the existing Po-210 has decayed, you don't have Po-210. Po-210 is in the uranium chain, and if there are other elements above it in the chain also in the leaf, they could decay and you could get more.
 * However the next nuclide above it that has a half-life more than a few days is Radium-226, and the chain passes through radon, which is a gas. So I don't know what would happen with that.  Intuitively I suspect a significant amount of the gas would stay in the cigarette until it decayed, but I'm not sure. --Trovatore (talk) 20:07, 23 June 2011 (UTC)


 * A link for the decay chain - it's in Decay chain. -- Finlay McWalter ☻ Talk 20:40, 23 June 2011 (UTC)


 * Hmm if I read that decay chain correctly, "the next nuclide above [Po-210] that has a half-life more than a few days" is Pb-210 (22.3 years), not Ra-226. The chain starting at Pb-210 doesn't pass through radon, only through Bi-210. 98.248.42.252 (talk) 15:06, 24 June 2011 (UTC)
 * I guess you're right. So the question is, does the polonium in the cigarettes come from polonium in the fertilizer, or lead-210 in the fertilizer?  If it's from the lead-210, then waiting for the polonium to decay is useless; you'd have to wait 50x or so as long for all the lead-210 to decay.  --Trovatore (talk) 19:37, 24 June 2011 (UTC)
 * The radon will likely leach out, being and noble gas. 0.04 picocuries is and insignificant amount of radiation anyways... Dauto (talk) 20:45, 23 June 2011 (UTC)
 * As whole-body exposure, sure. The problem with polonium is that it can be concentrated in tiny particles that stick around and keep irradiating the same nearby cells.  There is serious concern that this is a significant contributor to smoking-related lung cancers.  Personally I'm not in a position to know whether that's justified or not. --Trovatore (talk) 20:53, 23 June 2011 (UTC)
 * This is a minor contributing factor to lung cancer -- it does contribute somewhat, but most of the lung cancers in smokers are due to nasty chemicals like benzopyrene, phenol, etc. (which are inhaled in much greater amounts than polonium). 67.169.177.176 (talk) 21:53, 23 June 2011 (UTC)


 * (ec) The NYTimes article suggests that for pack-and-a-half a day smokers, it's equivalent to 300 chest x-rays over a year. That strikes me as a fairly significant source of cumulative radioactivity in a fairly risky exposure route (burned and deliberately inhaled deep into the lungs). But I'm not a health physicist. --Mr.98 (talk) 20:57, 23 June 2011 (UTC)


 * One group estimates that it causes 11,700 deaths yearly. But oddly enough, four World Trade Center attacks a year is just 2% compared to the 5.4 million deaths from tobacco overall (both figures are worldwide statistics).  Also, I'm seeing claims it's more from phosphate fertilizer than nuclear testing, at least nowadays; makes you wonder where else that fertilizer goes. Wnt (talk) 18:23, 24 June 2011 (UTC)


 * (*groan*) Do you have to drag the 9/11 attacks into this? Remember, there's no moral equivalence whatsoever -- death from cigarettes is due to the voluntary consumption of a harmful product (and therefore is the moral equivalent of, say, getting yourself killed due to reckless driving), while the deaths in the 9/11 attacks were due to a deliberate attack on our homeland by evil savages whose goal is to kill or subjugate everyone in the world.  Comparing the two is an insult to all who lost their lives in the 9/11 attacks.  Also, comparing the deaths from the 9/11 attacks in the USA alone (which they were) to any worldwide statistic is misleading even from a purely mathematical point of view. 67.169.177.176 (talk) 21:01, 24 June 2011 (UTC)
 * I think he was just using 9/11 as unit to measure number of deaths. There's nothing wrong with that. Dauto (talk) 21:25, 24 June 2011 (UTC)
 * Let's not forget that the companies for many years pretended their cigarettes were safe; then they sold "low tar low nicotine" cigarettes knowing that only the machines used to test them were actually getting lower tar and nicotine. There is not a complete lack of moral responsibility here.  To editorialize just a moment, there is also not a complete lack of responsibility when you spend $1 trillion on a war mostly to make an excuse for why you got out of Saudi Arabia like Osama bin Laden told you to, but spend only a few billion trying to help smokers quit or trying to cure cancer.  It's fair to make a numerical comparison. Wnt (talk) 00:15, 25 June 2011 (UTC)
 * "Spend $1 trillion on a war mostly to make an excuse," blah blah blah?! Come ON, are you REALLY as stupid as this -- or are you trying to PURPOSELY disinform the public to undermine their will to fight the enemy?!  This war is NOT about making any kind of excuses -- it's about FINDING AND KILLING terrorists and their supporters, and about AVENGING the evil they have done to our country!  And even if we spend ten times as much money fighting this war while suspending all other government spending (medical etc), it would still be justified because we MUST avenge these dastardly attacks at any cost!  Besides, when you cited the statistics for cancer deaths, you gave the worldwide statistics as if we had any duty to try to cure every cancer patient in the world, even though even in terms of government spending priorities, our government only has a duty to help our citizens who suffer from cancer, not some Paki or Somali savages!  So if you want to make a fair numerical comparison, give the statistics for the USA alone, not for the whole world (most of which isn't worth saving anyway)!  And last but not least, your figure of "a few billion" is DELIBERATELY MISLEADING because it includes ONLY government spending on cancer research, NOT the many billions in PRIVATE funding spent on it!  So go look up the true statistics, and don't come back here until you do!!! 67.169.177.176 (talk) 09:36, 25 June 2011 (UTC)
 * And while you're looking, I've found some TRUE statistics here: http://docs.google.com/viewer?a=v&q=cache:fzhbRXideW0J:www.iom.edu/~/media/Files/Activity%2520Files/Disease/NCPF/Fund.pdf+cancer+research+private+funding&hl=en&gl=us&pid=bl&srcid=ADGEESjqRCKhdm-EP2zJnyqneMDStNdmyAXKdSULwfZI2DpNRAFmhttulDj9i5dcSWNCStnu8bZ_YTuNDC78_vi3cr6aulvFWd-Z_tVh6Qax1R9tlHSEFmukqlJ3K-yqRem5I7c8q46m&sig=AHIEtbS1bGdcY2Ix0Tysv0sGu1bHjDHTIg. Among other things, it says right there that cancer research funding BY NGO'S ALONE amounts to almost 58 BILLION dollars!  So don't even try to mislead the public with your bullshit "statistics" -- the truth is right in front of everyone! 67.169.177.176 (talk) 10:00, 25 June 2011 (UTC)
 * Correction to the above: 58 BILLION dollars is incorrect -- I misread the number because Wnt's comment about the War on Terror being "an excuse to get out of Saudi Arabia" made me so mad that I was literally seeing double. The correct number for private, nonprofit foundations only is 58 million for the year 1997.  All the same, for every dollar spent by the government on cancer research, more than a dollar is spent by the medical industry and by nonprofits, so the actual spending on cancer research is still more than double what Wnt would have us believe.  And besides, what really matters is not how much money gets spent on curing cancer, but how effective it is in actually reducing cancer deaths: check out the article War on Cancer and see for yourselves the significant across-the-board decrease in cancer deaths in our country.  As for ALL my other comments on this thread, I still stand by them. 67.169.177.176 (talk) 18:41, 25 June 2011 (UTC)
 * And another piece of statistics from www.cancer.org: The number of deaths from lung cancer in the USA (from ALL causes, including asbestos, PAH's, etc. -- not just from tobacco) in 2011 is 156,940 (which is still a lot) -- NOT 5.4 million! 67.169.177.176 (talk) 10:49, 25 June 2011 (UTC)
 * And a message to everyone else regarding User:Wnt: this user has recently made deliberately misleading statements regarding British and American history; for example, in a recent discussion he/she stated that workhouses were intended as a system of extermination through labor, similar to the Soviet Gulag, despite ample evidence to the contrary; made preposterous and deliberately defamatory statements accusing the British people of cannibalism and of systematically murdering their own poor; and purposely tried to conflate racial discrimination in the United States with extermination through labor. In light of this, any statements made by the above user regarding history and/or current affairs should be regarded as having zero credibility. 67.169.177.176 (talk) 11:07, 25 June 2011 (UTC)


 * I don't think this is the right place for that kind of rant. It's an off topic, controversial, impolite, white noise. Dauto (talk) 14:46, 25 June 2011 (UTC)
 * And Wnt's off-topic, counterfactual, slanderous, anti-American "editorializing" isn't?! 67.169.177.176 (talk) 18:30, 25 June 2011 (UTC)
 * I'll admit that I am prone to stray off topic now and then in these answers - though the numerical comparison was not. And I'm not anti-American, just opposed to the Republican inner circle which has terribly abused the high-minded ideals of an underinformed and overly trusting populace.  (Nigerian yellowcake, Valerie Plame, remember?)  Tobacco does kill 5.4 million yearly.  It is no ordinary delusion that makes someone believe 3000 > 5400000, and yet I will admit, I don't think 64.169's opinions are unusual. Wnt (talk) 21:07, 25 June 2011 (UTC)
 * What makes you think that 156,940 = 5,400,000? 67.169.177.176 (talk) 23:40, 25 June 2011 (UTC)
 * Or let me put it this way: What makes you think that the larger portion of the 5,400,000 are of more importance than the 3,000 (much less the 156,940)? 67.169.177.176 (talk) 23:54, 25 June 2011 (UTC)
 * To be clear, not all tobacco deaths are from lung cancer - heart disease, COPD, emphysema, for example. See health effects of tobacco.  And of course the U.S., having made great strides early on toward reducing smoking, has a lower tobacco death rate than some of the developing countries to which tobacco is exported. Wnt (talk) 00:14, 26 June 2011 (UTC)

Crystal Violet Tetrazolium Agar
How does CVTA select for gram negatives? The agar has roughly 1% 2,3,5-Triphenyl Tetrazolium Chloride (TTC), which I am pretty sure is the selective agent. After some reading, it might have something to with the ability to reduce TTC in the electron transport chain, but what is different about gram negatives that help them grow better? — Preceding unsigned comment added by 132.236.177.203 (talk) 20:57, 23 June 2011 (UTC)
 * Crystal violet mentions that the stain works because it kills gram positives, not that it only stains the negatives. 157.22.42.3 (talk) 05:47, 24 June 2011 (UTC)

Testing medicines
Suppose you have some antibiotic pills from a less-than-reputable source, and you suspect that they might actually be placebos. How can you test this to be sure, other than by administering them to a live patient and seeing if they work? 67.169.177.176 (talk) 21:56, 23 June 2011 (UTC)


 * From our article, Analytical chemistry "is the study of the separation, identification, and quantification of the chemical components of natural and artificial materials." Specific chemical assay techniques exist for a variety of types of chemical; you may need a biochemistry lab, inorganic chemistry lab, and so on, depending on what substance you're trying to positively- or negatively detect.  This is an incredibly broad question; but you can at least get an overview of the more common instrumental methods used to identify chemical compounds.  Nimur (talk) 22:32, 23 June 2011 (UTC)


 * Actually, I have a lot of experience in analytical chemistry -- I've spent much of my life so far working in chemistry labs and petrochemical refineries. What I wanted to know was, what are the best techniques to distinguish penicillin-type antibiotics from inert placebo pills.  In particular, is there any kind of "field test" that allows this to be done without resorting to complicated lab equipment such as NMR machines and the like?  67.169.177.176 (talk) 01:19, 24 June 2011 (UTC)


 * Culture some bacteria in a dish and then dump the contents of a pill on it and see what happens? Looie496 (talk) 02:41, 24 June 2011 (UTC)


 * Just for the sake of clarity, from placebo: "Sometimes patients given a placebo treatment will have a perceived or actual improvement in a medical condition, a phenomenon commonly called the placebo effect" (emphasis mine). So administering the pill and recording positive results would not be a reliable indicator that the pill contained active ingredients that were the direct cause of recovery. (This part of why e.g. homeopathy can garner many anecdotal successes.) SemanticMantis (talk) 01:27, 24 June 2011 (UTC)
 * Or prayer, for that matter. ←Baseball Bugs What's up, Doc? carrots→ 02:05, 24 June 2011 (UTC)


 * Besides analytical chemistry, one could also probably test for their effect, by growing a bacterium that is known to be susceptible to the antibiotic in a petrie dish, and grinding up a sample of the pills and adding it to the dish. One would probably want to do a controlled study with several dishes, some getting pills that are known to be good, some getting a placebo, and some getting the questionable pills.--Srleffler (talk) 02:16, 24 June 2011 (UTC)
 * you have some antibiotic pills from a less-than-reputable source, This is the part that concerns me: What are you doing with antibiotics from "less then reputable" sources? I'd be throwing them out. I'm all for "do it yourself" attitude, but if you are really concerned about the product and it was procured legally, I'd be contacting the local drug regulatory authority, like the FDA in the states. Vespine (talk) 02:22, 24 June 2011 (UTC)
 * "What are you doing with antibiotics from less than reputable sources?" I'm not.  Just so you know, this has to do with research for my second novel, which is a sequel to the one that's just coming out.  You might remember me asking about bear maulings, backfiring shotguns, emergency surgery, landing in bad weather using only an NDB for guidance, etc. (or maybe not -- that was before my year-long boycott of Wikipedia, and I think I had a different IP address back then).  Well, my sequel will be mainly about a large-scale avalanche rescue, but there will be a little bit about the bear-mauling victim from the first novel.  What happens with him is, the rescue team brings him to a hospital in Canada for follow-up treatment, but he ends up having to wait for a long time to get the surgery because of rationing, and in the meantime he gets worse because the hospital has bought its antibiotics from India to save costs, and they turn out to be bad.  Hope this comment makes it clear to you. 67.169.177.176 (talk) 21:19, 24 June 2011 (UTC)
 * It's worth further noting that a hypothetical "less-than-reputable source" isn't limited to providing a binary "perfect" or "placebo" choice when considering what sort of functional or field assays one might try to perform. The active ingredient could be cut with neutral filler, or with a cheaper alternative antibiotic.  In the latter case, the pill might well appear to have potent antibacterial effect, but unless the test bacteria were carefully chosen (or there were a whole panel of them, each with different, well-characterized antibiotic resistances) you'd have no way of knowing the label matched the contents.  (It's also not trivial to perform controlled tests of dose-response under field conditions, so the amount of active ingredient would be quite challenging to reliably ascertain.)  For that matter, one can get a nonspecific bactericidal effect just by replacing the antibiotic with potassium cyanide. TenOfAllTrades(talk) 03:59, 24 June 2011 (UTC)
 * Potassium cyanide?! Ouch!  (*gasp* *choke*)  This could easily kill the patient.  Thanks for the idea. 67.169.177.176 (talk) 21:31, 24 June 2011 (UTC)
 * There's actually a relatively simple quantitative test for the strength of antibiotic potency. See Kirby-Bauer antibiotic testing. The concept is you put a dilution series of the antibiotic of unknown strength onto a filter disk on what will grow to be a lawn of test bacteria. You then compare the diameter of the inhibited zone with that of a dilution series of an antibiotic standard when tested under the same conditions (which in practice means "at the same time, preferably on the same plate"). Now, in addition to not being able to tell the difference between antibiotic and cyanide, this will only tell you the ability to kill that particular bacteria you tested. If the antibiotics are different, you won't get consistent results with different bacteria. For example, if your standard was streptomycin, but your unknown was actually penicillin, you'll get different equivalencies if you test with e.g. Salmonella versus Staphylococcus. So if you have a completely unknown sample, your best bet is to go with a standard analytical method. Note that you might not need to go all the way to NMR - HPLC/GC can work just as well, assuming you have standards. Given the lack of chromophore on most antibiotics, though, detection may be an issue, although there are a number of detectors which may work, some of which have been miniaturized and simplified enough that they might be considered for use in a "field test". -- 174.24.222.200 (talk) 16:12, 24 June 2011 (UTC)
 * So he could get cultures of a few pathogens the drug is supposed to fight, make petri dishes with nutrient gel, dilute the "antibiotic" and test effectiveness. Then to make sure it is not just some harmful poison or disinfectant, couldn't he administer it to suitable test animals (rats, mice, cats, dogs) in increasing doses to determine the LD50? Isn't this about what pioneer microbiologists did every day over a century ago? Edison (talk) 16:15, 25 June 2011 (UTC)
 * Yeah, that's what I was thinking too. But if he's gonna test for cyanide, then the Prussian blue test would work just as well. 67.169.177.176 (talk) 18:52, 25 June 2011 (UTC)

Just for the sake of reality in your novel: someone mauled by a bear in Canada would be in an emergency room at a hospital, and any necessary surgery would be done right away. (Only elective surgeries have ever had waiting lists.) There has been no case of below-standard drugs being sold in Canada. As far as I can confirm, purchases are made directly from manufacturers, most of which are based in Canada and the US. This would all be more likely if you placed your characters in the U.S. where surgery might well be delayed due to lack of patient funds and hospitals, who purchase their own drugs, might well be tempted by the cheaper sources with questionable quality controls.


 * In the United States, emergency surgery is never delayed (only elective surgery). Likewise, purchasing drugs from cheaper sources is unlikely for US hospitals, since they can pass the costs to the patient (although now that we have Obamacare, they just might).  The only way someone in the US would become a victim of counterfeit drugs is if he/she was given a prescription for outpatient antibiotic treatment and decided to save on costs by buying from one of those "too good to be true" suppliers.  (Or from an online clinic.) 67.169.177.176 (talk) 22:04, 24 June 2011 (UTC)
 * Also for the sake of clarity: the emergency part of the surgery has already been performed in the field (toward the end of the first novel), and the patient has been transported to the hospital several days later to get some broken bones reset properly (which the field surgeon on the rescue team could not do for lack of proper equipment). I don't think this would qualify as an emergency surgery, since there's no gangrene involved (the fractures have already been debrided).  Would this still be given urgent priority? 67.169.177.176 (talk) 22:12, 24 June 2011 (UTC)
 * If the bones need surgical setting, then yes, it's considered urgent. "Elective", in this case, would be something like reconstructive plastic surgery. --Carnildo (talk) 00:24, 25 June 2011 (UTC)