Wikipedia:Reference desk/Archives/Science/2012 November 12

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November 12

Size of Eliminated Dendritic Spines

Hello. Can an eliminated dendritic spine have a size? If so, why can such spines classified as "eliminated"? --Mayfare (talk) 01:32, 12 November 2012 (UTC)

If it has been eliminated, it no longer exists. It is possible that at least in some cases spines are actually reduced to a nub rather than eliminated, but such a spine could not properly be said to be eliminated. Was there some statement somewhere that created this confusion for you? Looie496 (talk) 03:21, 12 November 2012 (UTC)

The only occurrence of this phrase coming up on straight Google was at [1] - see figure 1H, in which the yellow square (lower row of panels) marks the eYFP signal corresponding to a single dendritic spine that goes away. As you see, the spine itself disappears, but it still occupies space in terms of the length of dendrite that is now unmarked by a spine. I assume this is what is meant by that, but could easily be wrong. Wnt (talk) 04:13, 12 November 2012 (UTC)

The last full sentence of the second page in http://www.nature.com/neuro/journal/v15/n7/abs/nn.3134.html --Mayfare (talk) 05:56, 12 November 2012 (UTC)

I guess you mean this sentence: "Measures of the relative size of eliminated spines—a measure of synaptic strength—showed no differences across groups (Fig. 2c), indicating that our stimulation paradigm was not causing the loss of a specific subgroup of spines.". My take on that is that they mean the size of a spine before it was eliminated. Looie496 (talk) 07:18, 12 November 2012 (UTC)

IQ and artists

I know that there's a correlation between IQ and performance in professional careers, like medicine and law. Have any studies explored the correlation between IQ and artists? 65.92.7.202 (talk) 03:45, 12 November 2012 (UTC)

We have a section, IQ#Social_outcomes. I looked at some of the studies linked there in, but the best ones are paywalled so you probably won't have access to them. The gist is that IQ is a better-than-random predictor for performance at virtually every entry-level job, and usually the best. This is assuming you have controlled for variables such as education, age, and socioeconomic origin. As far as music goes, the research discussed in our article looks at it from the other direction, asking the question "Does learning to play music make you smarter?" The answer seems to be yes. Someguy1221 (talk) 04:15, 12 November 2012 (UTC)

Do we have any substances or pills that are the opposite of anti-depressants?

Specifically, I would mean depressants in the mood or emotional sense, not in the CNS or respiratory sense. Do we have a pill that can make you sad, or less happy? If anti-depressants are SSRI (Seratonin reuptake inhibitors), do we know of any seratonin reuptake promoter, or dopamine reuptake inhibitor?

I ask out of curiosity, because it seems like an interesting field of research as to its possibility and effects, and possible treatments for extreme cases of narcissistic personality disorder or mania fits (or insert other potential uses here). Is this even possible? Is there research into it? Ehryk (talk) 06:12, 12 November 2012 (UTC)

See depressants. StuRat (talk) 06:57, 12 November 2012 (UTC)

No no no - I don't mean CNS depressants, as I said, and I don't mean depressants as opposed to stimulants. I'm talking about 'a pill that makes you feel sad', the opposite of 'a pill that makes you feel happy.' Ehryk (talk) 07:02, 12 November 2012 (UTC)

(ec) That's the wrong article -- depressogenic is the one that refers to mood. Adding to it: (1) There is a drug called tianeptine that works as a selective serotonin uptake enhancer, but strangely, it seems to have antidepressant effects rather than prodepressant effects. (2) Dopamine reuptake inhibitors do not have depressive effects, rather the opposite -- in fact, cocaine is a dopamine reuptake inhibitor. Looie496 (talk) 07:05, 12 November 2012 (UTC)

The way tianeptine works doesn't seem completely strange, the brain tries to keep the homeostasis, so a push in one direction can have an effect in the opposite direction. Philoknow (talk) 18:23, 12 November 2012 (UTC)

The nearest that I find: Recreational_drugs#Depressants. Comploose (talk) 19:01, 12 November 2012 (UTC)

Thank you. Next time, carefully read the entire question as well as the previous answers, so you'll suspect that having depress in its name doesn't make it what the OP wanted. —Tamfang (talk) 06:16, 13 November 2012 (UTC)

Transmission of radioactive and electromagnetic rays through glass

Can alpha, beta and gamma rays pass through glass ? Sunny Singh (DAV) (talk) 07:40, 12 November 2012 (UTC)

Alpha: no, beta: no, gamma: generally yes, with the added bonus of often colouring the glass through prolonged exposure. Fgf10 (talk) 07:54, 12 November 2012 (UTC)

It isn't really a case of each ray being able to penetrate or not penetrate. How much gets through depends on the energy of the radiant particles and the thickness of the glass, as with any media. For a thick piece of glass, the rays suffer attenuation per unit distance. Sufficiently energetic (ie.e, accelerated) betas (ie electrons) will penetrate glass without too much attenuation if it is not too thick. If it were not so, linear accelerators and other sorts of accelerator could not work. Floda 120.145.138.192 (talk) 12:36, 12 November 2012 (UTC)

The electrons also suffer energy loss due to their ionising effect so for any given energy there is a maximum distance they will penetrate. Dmcq (talk) 14:48, 12 November 2012 (UTC)

Follow up question,
OK, gamma ray can pass through glass. In electromagnetic spectrum, ultraviolet ray lies between gamma ray and visible light. The latter two can pass through but former cannot. Why ? Sunny Singh (DAV) (talk) 16:38, 13 November 2012 (UTC)

There are numerous, distinct physical phenomena that contribute to the bulk optical density of a material, and not all effects are monotonic with respect to the wavelength. Nimur (talk) 18:25, 13 November 2012 (UTC)

square ring falling through magnetic field

Suppose you have a square loop falling through a circular loop through which a current flows. Is there an equation relating the position of the square loop to time? Widener (talk) 07:42, 12 November 2012 (UTC)

You can write a system of differential equations for this problem. However I am not sure that it has the exact analytic solution. Ruslik_Zero 18:40, 12 November 2012 (UTC)

Mil Mi-24

Is the Mil Mi-24 attack helicopter equipped with infrared camera?--Wrk678 (talk) 10:51, 12 November 2012 (UTC)

This undated article (December 2008 or later) states "Russian Army Mi-24s are being upgraded with new avionics including thermal imagers." This article, also undated, mentions an "upward hinging cover for IR sensor" for the Mi-24K. Clarityfiend (talk) 11:11, 12 November 2012 (UTC)

Although if this is connected with your previous question; Noveber 4: Syria Rebels, then that is a different matter. Alansplodge (talk) 18:20, 12 November 2012 (UTC)

Yep. Buying a helicopter is much like buying a car in that nearly any accessory can be added -- provided you're willing to pay for it. Even if there was no integrated infrared camera option for an Mi-24, a bolt-on camera and an independent controller/screen for the cockpit can't be all that difficult to add if "getting it done" is more important than "doing it right". — Lomn 23:53, 12 November 2012 (UTC)

Well, allow me to expand on my question then, is the infrared camera "standard" or is it usually a add on? Also I'm referring to a infrared targeting system for their 30 mm machine gun and rockets.--Wrk678 (talk) 10:44, 13 November 2012 (UTC)

I had a good look on the web, but Google couldn't find anything for me. I think it's a fairly safe bet that if the Russians had to fit it as an upgrade, then it wasn't supplied as standard to the Syrians. Many aircraft manufacturers have an "export version" for sale to developing countries, with much more limited electronics, to reduce both the purchase price and the maintenance costs, and further to avoid secret technology falling into the wrong hands. So I'd assume that the Syrian Mils had a very limited sensor fit unless you can find a source that says otherwise. Sorry I couldn't be more helpful. Alansplodge (talk) 13:56, 13 November 2012 (UTC)

What is "matter" according to modern physics?

In classical Physics essential feature of "matter" was "mass". Right? Now since "mass" and "energy" are same so what is the defining characterisic of "matter"? :: Vineet Chaitanya 14.139.82.7 (talk) 13:18, 12 November 2012 (UTC)

Unsurprisingly, there's an answer in our article on matter: Matter is whatever possesses mass and occupies space. This is then linked to the Pauli exclusion principle. AlexTiefling (talk) 13:32, 12 November 2012 (UTC)

Can you just have one of this features? For example, occupy space but not have mass, or have mass but not do not occupy space? Philoknow (talk) 18:10, 12 November 2012 (UTC)

Both I believe. There are particles with no rest mass, like the photon, which presumably occupy space, and massive objects which have no volume, like the gravitational singularity in a black hole. StuRat (talk) 19:25, 12 November 2012 (UTC)

Per the Simpsons, "What is mind? No matter. What is matter? Never mind." μηδείς (talk) 23:23, 12 November 2012 (UTC)

Simpsons? George Berkeley must be rolling about in his grave. Even a hundred years ago, Bertrand Russell complained about it being hackneyed. Matt Deres (talk) 02:09, 14 November 2012 (UTC)

Stu, photons do not occupy space (in the sense that if it is there nothing else can be there). They are bosons and thus are not bound by Pauli's principle, which is a fermionic statistic. On those scales the laymam's ideas of "mass" and "occupy space" as we know them are not really meaningful. 24.92.74.238 (talk) 01:45, 13 November 2012 (UTC)

Aren't photons a type of imaginary particle whose entire existence is defined purely by its history? History includes: absorption, emmision, and gravitational interaction. Plasmic Physics (talk) 02:54, 13 November 2012 (UTC)

What is imaginary? All the words and concepts we use to describe the physical world are heuristic. An atom is "imaginary" at that level. Photons are exactly as real as atoms are. They behave differently than atoms do, but that doesn't make them any less or more real. So, it isn't helpful to think of concepts like "real" and "imaginary". The concepts "useful" is far more important. Photons are useful heuristic in explaining how the world works, so we use it. Atoms are a useful heuristic as well. But using concepts like "real" and "imaginary" misses the point in the same way that concepts like "facts" and "proof" misses the concept of science. --Jayron32 04:15, 13 November 2012 (UTC)

I mean, an atom can actively be observed, a photon can never be observed, because observation destroys it. You can observe what an atom is doing, but you can only deduce what a photon did or will do. The difference being, atom is the falling tree in the forest that can be seen, whereas a photon is the falling tree that can only be heard. A photon is in this way more heuristic than atoms. Plasmic Physics (talk) 07:55, 14 November 2012 (UTC)

"Hey this mass has lost some energy, lets call it a photon." Plasmic Physics (talk) 03:09, 13 November 2012 (UTC)

I don't think you should take that article too seriously. At least read Talk:Matter (and note there are two archive pages). There's no platonic entity "matter" whose properties are discovered by physicists; it's just a word and may mean different things to different physicists. I'm not sure there is a good single definition. "Has mass and occupies space" is clearly no good. The non-baryonic dark matter doesn't occupy space, but you can't argue it isn't matter—it's right there in the name. Just "has mass" doesn't work either because, as the original poster said, everything has mass. No one would say that the energy stored in a battery is matter, for example.

In many cases "matter" is short for baryonic matter (that is, stuff made of atoms) or for other things made of quarks such as nuclear matter and strange matter. Otherwise I think it's assigned haphazardly by individual physicists based on a loose analogy with baryonic matter. -- BenRG (talk) 21:46, 13 November 2012 (UTC)

Nothing; what is matter you? Gzuckier (talk) 19:30, 15 November 2012 (UTC)

Getting a given wavelength radio signal given an antenna with real-world constraints

Wavelength is related to transverse distance between peaks, not axial displacement of charge carrier.

Supposing you are given a transmitting antenna of whatever type of metal is most commonly used these days, and supposing that you are applying an AC current with the intent of transmitting a 1 m wavelength radio signal, about how far is one electron likely to make it in one direction along the antenna conductor in one half cycle from a negative peak to a positive peak, factoring in the likelihood of the presence of antenna material atoms affecting the electron's path? Can individual charge carriers actually make it very far (on the order of meters) through metal?

But if the answer is that individual charge carriers actually only make a microscopic or very small displacement in space, how could a 1 m electromagnetic wave be produced? I don't see how a large number of charge carriers each only making a very small displacement in space can add up to a 1 m wave.

This site, especially Fig. 2 there, is where I'm getting my basic understanding of how alternating current gets an EM wave transmitted. From that is where I got the feeling that charge carriers would actually need to make a displacement in space on the same order as the intended EM wave. Peter Michner (talk) 16:43, 12 November 2012 (UTC)

The individual electrons will only move a very small distance - see drift velocity. In the example on that page, the electrons only move a couple of nanometres (that's ignoring the random motions the electrons have anyway and just includes the motion induced by the electricity). It may help to think of it like a Newton's cradle. The balls in the middle hardly move at all, but they are still able to pass the energy along. One bumps into the next, which bumps into the next and so on. Electrons carrying current through a wire do roughly the same thing (it's not a great analogy, but it might help to see that lots of things moving a very small distance can add up to result in large movements). --Tango (talk) 18:25, 12 November 2012 (UTC)

I think I get it now after looking at this visualization. The radiated field wavelength doesn't have to do with the physical displacement of the charge carriers in the direction of the conductor, but is related to the transverse distance perpendicular to the conductor with the waves emanating out at the speed of light (in a vacuum, and only slightly slower in a medium such as air) as shown by this picture which I just made to try to explain it to myself. Peter Michner (talk) 19:32, 12 November 2012 (UTC)

Long time effect of drugs

Some people lose their mind after too much use of recreational drugs, and their brains never get tuned again, even if they stop to take drugs. Is the opposite case also possible? Could someone who goes through a controlled therapy change the chemistry of his brain long term but in a positive direction? Comploose (talk) 17:46, 12 November 2012 (UTC)

First of all, we need to figure out what we mean by changing the chemistry of the brain in a positive direction. We tend to consider any deviation from the norm to be a bad thing (evolution tends to do a pretty good job of finding a fairly optimal norm, so that's not a bad definition). I can imagine situations where someone has some kind of neuro-chemical disorder that is permanently cured by medication - would you count that? Or are you specifically looking for improvements above the norm? --Tango (talk) 18:29, 12 November 2012 (UTC)

Nope, no improvement above the norm. Just if, for example, a schizophrenic or depressive patient goes through a treatment with psychoactive drugs, can his brain chemistry be changed for ever, or for a long term, after he stop taking the medication. Comploose (talk) 18:45, 12 November 2012 (UTC)

• To begin with, the claim that people may lose their minds after overuse of recreational drugs is very dubious, unless they overdose to a degree that causes brain damage due to the heart or lungs shutting down and depriving the brain of oxygen. But to address the main question, ECT is a therapy that is supposed to change the chemistry of the brain long term in a positive direction, for people who are depressed. There is some recent evidence that ketamine also can cause long-term positive changes in depressed people. Looie496 (talk) 18:50, 12 November 2012 (UTC)

• "Lose their minds" might be overstating it, but many drugs can cause negative long-term brain changes. StuRat (talk) 19:27, 12 November 2012 (UTC)

• There are a lot of neurotoxic recreational drugs, that could cause Olney's lesions among other things. I don't know exactly what is meant by "lose your mind". Has someone suffering from Parkinson lost his mind? He will be able to think, but not to control completely his movements with his brain. OsmanRF34 (talk) 21:02, 12 November 2012 (UTC)

I'd be more optimistic of changing the brains of children in a positive way than adults. In adults, the basic way the brain works is already established, and only incremental improvements are normally possible. StuRat (talk) 19:29, 12 November 2012 (UTC)

Drugs are used as part of successful therapies to overcome such things as alcoholism and acute psychological traumas, PTSD and OCD with varying success rates. See librium, valium, antabuse and so forth. It's also certainly not dubious that people become psychotic or terribly damaged long-term after drug abuse and some don't recover. μηδείς (talk) 23:21, 12 November 2012 (UTC)

I agree with Medeis, from professional experience (OR, ?not valid) I have seen about 6 cases over 20 years of individuals who have lapsed into serious mental illness triggered by the use of recreational drugs - mostly cannabis. The relationship between their mental illness and the taking of RDs was not dubious. @ StuRat, so that means that antidepressant and antipsychotic medication is ineffective? Richard Avery (talk) 08:16, 13 November 2012 (UTC)

Meds can still work to treat adult mental problems, but are unlikely to cure them. That is, once adults go off their meds, you can expect their problems to return. StuRat (talk) 08:37, 13 November 2012 (UTC)

That's rather broad, StuRat. You might be better off saying congenital organic problems are rarely permanently curable, as opposed to acute psychological trauma, which can be more pliable. μηδείς (talk) 05:15, 16 November 2012 (UTC)

For an example dealing with rewiring the brains of children, emerging evidence supports the idea that if autism is successfully treated early in the preschool years, this can prevent much of the damage to the brain, which otherwise locks them into autism for the rest of their lives. StuRat (talk) 08:41, 13 November 2012 (UTC)

Evidence of filamentation of the milky way

Given that dark matter sculpts the galaxy clusters into filament structures I would assume that this is also an effect at smaller scales such as our Galaxy itself.

Is there any evidence of filamentation of the 1) Milky way galaxy and also 2) The gas in our solar system.

I can visualize the dark matter as tiny chargeless particles flying towards more massive objects and causing a sort of "gravitational current" effect which causes the filament structures . Am I on the right track? :) --Ap-uk (talk) 18:52, 12 November 2012 (UTC)

I'm not sure it's correct to say dark matter is what "sculpts" the galaxies into the formation they take. It would certainly play a part, if it even exists, which I don't doubt very much, but it's not certain yet. Whatever effect dark matter has, it's quite weak, so weak that it is difficult to measure on sub-galactic scales. That's why we didn't notice it for so long. Looking for it inside our galaxy is hard, we really notice the effect when we look at whole galaxies or on groups of galaxies. Looking for an effect of dark matter on gas in our solar system would probably be a waste of time at this stage. Also most of the current best theories don't describe dark matter as "tiny" particles. Maybe you should give our dark matter article a good read. Vespine (talk) 21:37, 12 November 2012 (UTC)

I don't think there is any reason to assume that the universe will show the same structure at different scales like that. There are other factors dominating the structures of galaxies and solar systems that would completely eliminate any kind of dark matter filament structure. I'm not sure we even have any good theories for how galaxy filaments formed - without that, there is no way to extrapolate to other scales. --Tango (talk) 22:47, 13 November 2012 (UTC)

plastic PE discoloration

hello i was asking about the plastic PE film tube discoloration to reddish or yellowish since it will be changed after putting in a warehouse or even inside the plant and this matter will happen after only few days. thank you — Preceding unsigned comment added by 77.31.104.159 (talk) 20:55, 12 November 2012 (UTC)

It's not clear what you are asking. Do you want to know what caused it, how to prevent it, how to repair it, or what ? And what's a PE film ? StuRat (talk) 20:57, 12 November 2012 (UTC)

I assume PE = Polyethylene. Perhaps if it's being stored at high temperature it could be loss of plasticizer? or some sort of side reaction? I agree though, more information would help. (+)H₃N-Protein\Chemist-CO₂(-) 21:36, 12 November 2012 (UTC)

cornstarch and water experiment

I have been looking everywhere for this. I am doing a science project and I don't have a good idea for my research draft.It has to be 1-5 pages.what I mean is that it can be 2-4 or 1-3 or 2-5.So what I need is a good research draft.Can I have help? — Preceding unsigned comment added by 99.32.182.192 (talk) 22:31, 12 November 2012 (UTC)

It is difficult for us to answer with regards to the expectations of your teacher. As a teacher myself, I wouldn't object if a student asked me for a clarification on my requirements regarding an assignment. Length requirements are a secondary issue: the teacher wants you to write enough to completely cover the topic of the paper, but to not drift into off-topic writing. Remember that longer is not better, but incomplete is also bad. Your goal should be completeness but not excess. Still, your best option is to ask your teacher directly. A smart student with initiative gets their assignment done several days in advance, and asks their teacher to look it over briefly to see if any adjustments need to be done before the due date. A good teacher will give constructive feedback to a student that does this. --Jayron32 22:35, 12 November 2012 (UTC)

Well, length should be a secondary issue, but, depending on the teacher, it may very well be their primary concern. I've had teachers grade almost solely based on length, and I shoveled lots of "filler" into everything I wrote for them, accordingly. StuRat (talk) 22:55, 12 November 2012 (UTC)

So, the one thing we can be certain of is that Jayron never taught StuRat? μηδείς (talk) 23:11, 12 November 2012 (UTC)

No, that does not follow. Stu had at least two other teachers other than Jayron, that much is certain. --Stephan Schulz (talk) 23:22, 12 November 2012 (UTC)

Nobody can predict how grade school teachers will act. But we have a piece of an article on "oobleck" under Non-Newtonian fluid and Wikiversity has some resources also. (Those are in an unusually advanced condition for Wikiversity, which is to say, it looks like a rough draft of something even if you're not quite sure what yet) Wnt (talk) 23:58, 12 November 2012 (UTC)

Jayron must be an exceptionally helpfull teacher if he gives students a pre-mark off the record assessment, just because individuals ask for it. Whether it is fair to all students is debatable. Remember, there are 3 basic reasons for marking assignments: 1) So the teacher and the teacher's superiors can asses his success at teaching; 2) to ensure students actually do the assignments; 3) Gating - i.e., only let thru students who have a demonstrated level of capability - knowledge, ability to think, and the ability to get work done. Would you be comfortable with a student asking another student look over a draft paper? That is sometimes done, but is generally considered a bad thing unless it is only to get help where you are stuck. It it always a bad thing if the student pays the other student. How is getting the teacher to give a pre-mark off-the-record assesment different? The teacher would need to be VERY carefull how he does this. Having said that, it is quite normal for university staff to provide such help with post-grad thesis papers - but this is done in very controlled ways, is acknowledged to be the norm, and when the thesis is marked, it's usually done by at least 2 people. I agree that it is quite acceptable for a student to ask in general terms what length is expected, just as it is acceptable to get any ambiguity in the assignment question resolved.

Particularly in 1st year university and college courses, there is another reason why teachers/lecturers set a required length for assignments. 1st year students sometimes come with an intense interest in certain topics and may be poor time managers. A student might, for example, happilly spend all week writing a most splendid longish paper on a subject he/she loves, and leave minimal time to do that difficult math assignment - but in fact the big picture is that he/she should have spent the time pondering the math and mastering it. It's not very good if at the end of semesterm you got an A in subject you love and a FAIL in subjects you didn't like - not good for you, and not good for the college or university. It's better to get a whole lot of B's and C's if that's what it takes to avoid any FAILS. Setting a max length on assigments helps prevent students not do more than is required and maitain a balance of effort.

Another reason for setting a maximum length is to force the students to be concise - that keeps the teacher's marking work load down, and sets the student up for his future - being concise is essential in employment. So, look at what you have been asked to write on. If you feel you can cover the subject quite well in 2 pages when 5 have been asked for, perhaps there's an aspect to the topic you haven't thought of?

Wickwack 121.221.32.50 (talk) 00:49, 13 November 2012 (UTC)

Your experiences must be very different from mine. I've never had a teacher who wasn't willing to look over drafts. Most of them refuse to give preliminary grades, but they do give detailed and helpful feedback. I've also never had a teacher who objected to students proofreading each others' essays. In fact, my school has a student-staffed writing center specifically for the purpose of proofreading other students' essays. --140.180.252.244 (talk) 02:12, 13 November 2012 (UTC)

Could be. You (140.180.252.244) geolocate to Princeton University (a very good university incidentally). Where you refering to Princeton or to a highschool? Certainly in my experience, getting such assistance from teaching staff in undergrad courses is just not possible due to their workload. I remember doing first year engineering math - about 2000 students from all engineering & science courses together in a large hall - and way down the front was the lecturer with a microphone. After presenting his weekly 2-hour excited no-stopping-for-anything recital, he would hang around another 10 minutes or so for questions, then nick off - we wouldn't see him until the next week. Each week during the 2 hour lectures in each subject they would set an assignment. We were required to submit them to the department clerk on or before the required date, along with a cover sheet and signed statement that it was all our own work and references credited. The clerk date-stamped them and gave us a receipt. A day or so later, the lecturer got all the assignments from the clerk, took them somewhere (home? his office?) and marked them. At the next lecture, he brought the marked assignments with him, and put them on the table for us to collect during the break. That was pretty much all the contact we had. If only (say) 1% of students somehow made contact and asked for advice, that would obviously take up more of the lecturer's time than his official commitment would. If you wanted him to advise you on a draft, you'd have to give the draft to to the clerk, and there was no reason why the lecturer would turn up until he needed to collect the assignments for marking. However, once you got past first year, the teacher-to-student ratio progressively improved considerably and much more contact/interaction happened. Wickwack 121.221.90.241 (talk) 02:42, 13 November 2012 (UTC)

• Regarding the debate being held above as to whether or not a teacher will give helpful advice to students who ask for it: It depends on whether the job of a teacher is to educated students or to assess students. I tend to think in terms of the former rather than the latter. I'm not particularly interested in assessment for its own sake. Assessment is important to understand what a student is learning, but education is not a game or a contest, and there aren't winners and losers, and I don't look at assessment as a means of deciding between winners and losers. If students wish to learn, my job is to teach them by any means necessary, and I'm not particularly interested in witholding instruction from students for any purpose. When Wickwack says "Whether it is fair to all students is debatable", it isn't debatable. The core of my soul does not allow me to not teach the student in front of me. A student who comes to me with the desire to learn something will not be held back in the interest of "fairness", as though education were some contest that I was unfairly helping this student "win". That's an odd conception of "fairness", in the sense that it presumes the only means of being "fair" is to treat education as a race to a finish line. It isn't, and I don't operate that way. I teach because I would die if I stopped. It is my air. I also recognize that not all teachers work this way. Not all plumbers do a good job of fixing my pipes either. I still hold the expectation that they will, and if they don't, I don't find that acceptable. --Jayron32 04:09, 13 November 2012 (UTC)

Jayron makes some good points and I certainly see where he is comming from. However, it is clear - expecially from his last sentences that he is an exceptional teacher, not a typical teacher. Yes, ideally, teaching is about teaching/educating, and not about gating. But, in practice, the gating part is important - very important. That's why I listed 3 reasons for marking in my earlier post. At the end of the day, employers use academic records (as well as other things) to work out who to hire. This reminds me of a conversation I had with a Head Of Department when I was a student representative: HofD: "This university is not about competition between students. It is about excellence" Me: "It is widely believed by students that it is competitive. Can you give me a tight reassurance I can take back to them?" HofD: "Yes, absolutely - see here - it is writen in core policy." Me: "Very good, now please tell me how the university guards against an individual exam paper being unexpectedly hard or easy affecting students in one particular year." HofD: "We know from experience that students fit a bell curve of ability, and any given assessable assignment or exam should return a certain average result. So, if the as-marked results seem out, we scale the marks up or down for the records." Me: "Ah, yes - actully I heard a rumour that the university uses a computer programme to do the scaling automatically on each and every subject." HoD: "Err... yes, that's correct - it is a well regardled software package used by many universities." Me: "So, in any one semester, if more than the expected number of students pass as marked, the computer will adjust so the right number fail." HofD: "Well, you can put it that way." Me: "So, in fact the assesment, as recorded, IS competitive - only the top approriate fraction of students will pass, not all students that passed the bar?" HofD: "Well, I always enjoy chats with student representatives. But its time for my next appointment. Goodbye!" Wickwack 124.182.149.73 (talk) 05:43, 13 November 2012 (UTC)

Sounds like your school needs some new plumbers. Ones that actually know how to fix broken pipes. --Jayron32 05:46, 13 November 2012 (UTC)

Nah. What we need is more funding to buy more pipe parts. Wickwack 120.145.40.78 (talk) 06:33, 13 November 2012 (UTC)

Or plumbers who don't take some fraction of broken pipes in your house is "acceptable". "It's OK that your downstairs toilet sprays shit all over the walls every time you flush. Both of your other toilets work acceptably well, and your shower is like, the best shower we've ever seen. So, it's alright that the other toilet covers your bathroom in feces. After all, we can't fix EVERY fixture, can we?" --Jayron32 06:51, 13 November 2012 (UTC)

We should be carefull not to stretch the metaphor too far. As I said, ideally we would educate everybody. In parctice, when you graduate from school, college, or university, it is about TWO things: 1) You've learnt something, which ought to be usefull in your life an career, but often in fact has little direct relavence (but if you learnt how to think, that is relevant); 2) You have proved you meet a certain hard to define standard and are thus certified as fitting within a subset of the population. Note that I did NOT say that folk without the certificate are not in that subset. I do say that just what standard you've met is hard to define, because you might have passed because of a) superior intellect; b) you were very determined (that one applied to me), c) you managed your time well, etc etc. When you go for employment, that's what employers look for - not so much what you learnt, but what sort of ability you have. So, if the poorest capability group of students don't get to pass, even if they DO know the subject, that sounds unfortunate, and it is, but from society's point of view that may be for the best. Such students are failures in term of marks, but there is no suggestion that they are as such failures in life or failures to society. We can't all be professors and presidents - some have got to be plumbers. A plumber is not a broken professor. And if you & they try hard, you can educate them to Ph.D standard, but that may degrade the standing of Ph.D's. Wickwack 120.145.40.78 (talk) 07:27, 13 November 2012 (UTC)

Quite frankly, I could give a flying fart what my grades mean to employers. My grades are a measure of what a student knows, and student assessments are just another pedagogical tool I use to adjust my instruction to meet the students needs. That doesn't mean that students don't fail, students that don't know the material for whatever reason get a failing grade. But, if every student in my classroom knows the material at the highest standards possible, their going to get the highest grade. I'm not going to fail some random bunch of students just because an employer expects to have some resumes to reject. I'm also not going to withold knowledge from a student who wants it, just because some employer wants to have some failing grades on a resume to reject. If a student shows the initiative to seek outside help, and they get it, and that's what helps them pass, great. If a student has the innate skill not to need that outside help, and they get the same passing grade as the student with less skill but more initiative, that's fine, because my grades don't differentiate between why a student knows the material I teach. My job as a teacher is to train students: if all of my students are trained to the standard they need to be, then they are all trained to the standard they need to be. I'm not going to fail some at random merely because their employers are bothered by the lack of ability to differentiate them by the grades in my class. That doesn't mean that I don't have students that fail (I do), but my grades are not primarily a tool for others to know anything more about a student than that they know the material on the curriculum. Grades can't tell an employer why the students know that material on the curriculum, whether via innate skill or extra effort. But they never could: grades never tell you that. --Jayron32 14:15, 13 November 2012 (UTC)

You and I agree on a lot - we just put some things in different words and other things in different emphasis. But you have missed some points. Yep, grades can't tell an employer much. I essentially said that above when I said that sucessful graduation comes from lots of things in a range of combinations. I said it when I said that having a qualification means you have met a standard but what that standard is is not clearly defined. But particularly when an employer is hiring a recent graduate with no relavent job experience, the qualification (degree, diploma, whatever) is his best guide to who is suitable. And if all candidates have the right/appropriate qualification and look pretty equal in interview, which one gets the job? The one with the highest grades, naturally. You might not care a fig what employers want, but your students should and most probably do - employment is what motivates students to do courses. It is not a case of failing some students at random. It is the weakest achieving students that get failed. Again, as I said before, that's not ideal, as it can be that some or all of the failed students actually have what the curriculum says they should have. But it's not a disaster either. A non-competitive education system is something that idealistic teachers (and students) often want. But industry, commerce, and government is always competitive, and there's nothing we can do about it. Competitive strength comes from (amongst other things) hiring the best graduates and this ultimately leads to a desirability to build some performance status into academic qualifications. That's one of the reasons why universities tend to demand students come with a high minimum score in their high school marks or some sort of entry exam - they don't just require a pass. You are idealistic, Jayron. I'm pragmatic. Wickwack 121.215.135.144 (talk) 15:21, 13 November 2012 (UTC)

Well, to be pragmatic, my impression is that cheating has increased to well-nigh universal levels,[2][3][4] so what is actually being assessed is moving away toward rote memorization or creative problem solving into the more practical assessment of whether students are willing to work around ethical obstacles and do what it takes to succeed. In an age where there seems to be little if any distinction between business and corruption, I suppose this reflects employers' priorities. Wnt (talk) 05:18, 14 November 2012 (UTC)

Very good point. The issue of cheating is an interesting one. When I was a student at university (decades ago now), I was fortunate to be at a uni that had very high ethical standards. And when I started my professional career, it was the norm that my employer (a very large company) put us through a 2-week ethics course to prepare us for interaction with customers and suppliers. It was a very good course. However, the personal skills/attributes that enable students to cheat easily (bad) are the same skills that facillitate team work in employment (good). The objectives are different - at school/college/uni, you are there to learn, but in employment you are there to get things done. And nothing in real life is wholely bad or wholely good. Wickwack 120.145.170.99 (talk) 15:14, 14 November 2012 (UTC)

Ye Olde Practical Student's Guide to Writing an Academic Paper on a Topic About Which You Don't Care:

Start with the Introduction. For the typical 5 pager you mentioned, after Title and a Heading which says "Introduction" and margins, this oughta get you to the middle of the first page. Then, basically copy your introduction in different words with "as we have seen", etc. to provide the Conclusion. Now put together your Bibliography, either what was given to you or what you dig up yourself. Maybe 6-8 entries is a good size, if you haven't been told how many. Now open up each of them and dig up something that references your topic/introduction. It pays to reference sources with an index, otherwise you'll have to make do with the Table of Contents to find something. When you find something relevant write it in your own words and/or quote part of it with attribution in half a page or so, between the Intro and Conclusion; needless to say, don't just copy it without attribution, or plagiarism will attack you. If it agrees with your intro/conclusion, great; if not, list it as if it's you considering all sides of the question: "However, blahblah states in his 'Blablahology', 'Blah blah blah'." If two of your sources are having an argument, then you've got a nice 'he said, she said' situation. Anyway, that oughta be enough to at least get you middle of the road grades on your paper/essay. Gzuckier (talk) 05:00, 13 November 2012 (UTC)

Off label use of drugs

How can it happen that some drugs are used off-label? If someone has reliable information about one use, it should be included among the normal uses of a medicine. If no one knows it it's reliable, why is someone using it? Comploose (talk) 22:50, 12 November 2012 (UTC)

Getting "reliable info" about a new use of a drug requires years of research and millions of dollars. It would also be difficult to prevent off-label use. StuRat (talk) 22:56, 12 November 2012 (UTC)

What Stu said. We have an article on off-label use, by the way. Someguy1221 (talk) 22:59, 12 November 2012 (UTC)

Doctors are allowed to prescribe any drug that is approved by the FDA, but they are generally not restricted in what they can prescribe it for. It sometimes happens that a doctor makes a judgement that the possible benefits of using a drug in a certain way outweigh the possible risks -- for example with a patient who will die unless an effective treatment is found. Looie496 (talk) 04:06, 13 November 2012 (UTC)

Basically, drug companies are much more legally restricted than doctors are. A drug company rep or salesperson can't even casually mention to a potential doctor or patient over drinks that they've got preliminary evidence that their new blood pressure drug also cures impotence, without the company being penalized by the FDA; but a doctor is free to prescribe anything for any random reason, with only the risk of malpractice suit to set limits. Because, who are you going to trust? A billion dollar company with a large scientific and statistical staff conducting tests and clinical trails all the time, or good old Dr. Welby who helped Maw Maw when her schizophreens were acting up back in aught five? Gzuckier (talk) 05:15, 13 November 2012 (UTC)

What drug-makers can say (in these United States) about their drugs doesn't depend on solid scientific evidence: it depends on what the Food & Drug Administration explicitly permits. If the FDA is impartial, apolitical, and competent, these two criteria are effectively equivalent; but one may reasonably have some doubts about whether that is the case. —Tamfang (talk) 06:28, 13 November 2012 (UTC)

As the off-label use article says pharmaceutical companies actively persuade doctors to prescribe off label. These companies spend more money marketing than they do developing and testing new drugs. This is well explained in the recently published Bad Pharma by Ben Goldacre an essential and frightening read for anyone interested in how the worldwide pharmaceutical companies operate to patients' detriment. Richard Avery (talk) 08:04, 13 November 2012 (UTC)

Bad Pharma by Ben Goldacre is definitely not an essential read. Ben Goldacre, like many physicists physicians doesn't deal well with statistics and get things wrong at several places. Painting a frightening picture might be quite useful for selling books, a field where Goldacre is pretty good, but it's simply skewing the reality to fit your view. It's not serious. Bottom line: for the several thousand medicines in the market, most are reliable and work as they are intended to work. OsmanRF34 (talk) 14:23, 13 November 2012 (UTC)

NB. Ben Goldacre isn't a physicist, he's a physician (a research fellow in epidemiology according to our article). AlmostReadytoFly (talk) 17:22, 13 November 2012 (UTC)

Sorry, my bad. I certainly didn't mean that physicists doesn't know enough maths. OsmanRF34 (talk) 19:05, 13 November 2012 (UTC)

The off-label use article says "it is illegal for the company to promote off-label uses to prescribers." Companies try to, if not blatantly break the law without being caught, at least skirt as close to the edge of the law as permitted, as in any industry; but the off-label thing is hard to bend directly, even by dropping hints. "Friendly" physicians (i.e. receive large retainers to have their names attaced to things) who have "interesting findings regarding new off label uses" can, however, be counted on to spread the news without urging. The FDA can be somewhat quirky in how they approve or reject drugs, but they're pretty reliable about not taking it well when they catch somebody violating their regs. Since a fine is often just a drop in the bucket compared to potential revenue, they often penalize the company by delaying consideration of a New Drug Application for 6 months or a year, which shortens the profitability life of a drug before the patent expires, which is the real crimp in a drug company's income. "Marketing research" is indeed at this point probably more important to a drug company than biochemical research; but probably tied with it is "patent law research". This is at least partially due to there just not being that much return on actual biochemical pharmaceutical research these days. We're going to have to see a major breakthrough in biological or physiological science before we are going to see the kind of boom in new therapeutics we once thought was going to continue forever. Gzuckier (talk) 19:47, 15 November 2012 (UTC)