Wikipedia:Reference desk/Archives/Science/2016 September 30

= September 30 =

Donations
Has there been any research done into whether people donate more money into the boxes in supermarkets when people can see money already donated (a clear box) vs when people can't (a solid box)? If not, what would you speculate the results would be? JoshMuirWikipedia (talk) 10:57, 30 September 2016 (UTC)
 * Oddly, I couldn't find any research on that exact topic. However, I did find the similar study "How is donation behaviour affected by the donations of others?", which found that the amount of money visible in the container had an effect on how people donated - people donated least when the box had coins in it, slightly more when it had nothing in it, and most when it had large bills in it. So I guess the answer is, it's complicated and depends on the donation dynamics of the situation. Smurrayinchester 11:19, 30 September 2016 (UTC)
 * An experiment where the visible content of a single donation container is varied and found to influence the type of subsequent donations lacks the necessary controls to draw conclusions about what affects how much people donate. Having large bills visible may either a) encourage a giver to match what they see with an equivalent donation, or b) dissuade a someone who intended to make a small coin donation from the embarassment of this being seen as paltry in comparison. The article about Controlled experiments explains how using controls (such as simultaneous donation collections at different but comparable locations) can eliminate such alternate explanations of experimental results. AllBestFaith (talk) 15:52, 30 September 2016 (UTC)
 * Churchgoers know all about this.  When I began attending church the minimum amount expected to be placed in the collection plate was half a crown.   Nobody wanted to be seen dropping coppers in there.   Later, to eliminate embarrassment, voluntary subscription envelopes were introduced.   The current state of play is that the collection is all notes - nobody would put coins in there. 80.44.164.18 (talk) 14:43, 1 October 2016 (UTC)
 * More at Parable of the widow's mite.  I'm guessing also that one factor that needs to be taken into account is how affluent is the area in which the collection box is situated. 80.44.164.18 (talk) 14:59, 1 October 2016 (UTC)

Kinetic data and reaction mechanism on sodium reactions
What kinetic data are reported in publications about sodium reactions with water, liquid ammonia and alkanols like ethanol? Is there some reaction mechanisms similarity in these reactions? Thanks.--5.2.200.163 (talk) 12:52, 30 September 2016 (UTC)
 * I don't have time to look further right now, but one ref I found is:
 * DMacks (talk) 13:51, 30 September 2016 (UTC)
 * Is there something similar for water? It may seem that there are some undecided mecanistic aspects about this apparently trivial reaction.--5.2.200.163 (talk) 14:41, 30 September 2016 (UTC)
 * I haven't found water yet, but here is with HCl:
 * (at least based on abstract...I can't access the full article right now). But yes, the mechanism for the general reduction of active-hydrogen compounds by 1-electron-donor metals does not seem straightforward! DMacks (talk) 19:45, 1 October 2016 (UTC)
 * (at least based on abstract...I can't access the full article right now). But yes, the mechanism for the general reduction of active-hydrogen compounds by 1-electron-donor metals does not seem straightforward! DMacks (talk) 19:45, 1 October 2016 (UTC)
 * (at least based on abstract...I can't access the full article right now). But yes, the mechanism for the general reduction of active-hydrogen compounds by 1-electron-donor metals does not seem straightforward! DMacks (talk) 19:45, 1 October 2016 (UTC)

Reflexes, chimp vs human
How do human reflexes compare with chimpanzee reflexes144.35.45.78 (talk) 14:19, 30 September 2016 (UTC)
 * This is an old study, but it appears to directly address your question. -- Jayron 32 14:47, 30 September 2016 (UTC)
 * That is actually a study on reaction time, not reflexes, however, the OP might have been using reflex to mean reaction - perhaps they would like to clarify. DrChrissy (talk) 18:16, 30 September 2016 (UTC)
 * So reflex indicates that it is involuntary, and nearly instantaneous, and that the stricter scientific sense of reflex arc is much narrower than the casual usage. Reaction time does seem to redirect to the right place. If I drop a book while standing next to you and you catch it before it hits the ground, I might say "Good reflexes DrChrissy!", even though that's not strictly scientifically accurate. If that's the kind of thing OP means, then the study Jaryon provided would seem to be very appropriate. The upshot of that work is that the reaction time of chimps is roughly indistinguishable from that of human children. SemanticMantis (talk) 19:40, 30 September 2016 (UTC)
 * Yes - the critical difference is that reflex arcs do not involve the brain. In vertebrates, the sensory nerve impulse  goes to the spinal chord and if immediate action is required to protect the animal, it is the spinal chord which "tells" the muscles to withdraw the limb or entire animal.  One example is when you burn your finger, you immediately withdraw your finger BEFORE you feel any pain.  In your book-dropping example, I would have to see the book falling, calculate the speed of the fall and place my hand in the correct place.  All this is conscious so technically speaking, it is not reflexes. DrChrissy (talk) 20:04, 30 September 2016 (UTC)
 * Though on occasions when I myself have dropped something, I'm fairly sure my attempts to catch it have been reflexes rather than reactions. I suspect this stems from pressing ancestral need to catch a branch when falling out of a tree. {The poster formerfly known as 87.81.2230.195} 90.202.211.191 (talk) 09:37, 1 October 2016 (UTC)
 * What about the times when you did NOT catch it? One of the features of reflex behaviours is that they are relatively non-plastic (i.e. response X is extremely similar to response X+1).  If catching a falling object was a reflex, you would catch it every time. DrChrissy (talk) 18:28, 2 October 2016 (UTC)


 * Yes, when I was a little kid (many moons ago) doctors were forever using their little hammers to hit me just below my knee cap to test my (patellar?) reflexes. Nervous impulses in primates (which include all of us) travel at the same speed. Don't have a references but the sea-cucumber has large, easy to dissect, nerves and so are easy to experiment upon in the lab – which is why they are often used for research. Given that  the mode of chemical transmission is the same as ourselves, guess that the speed is the same also. The  'cognitive' processing between species however, may differ and think this is what the OP means. Oh darn, my cat has just walked across my key-board and spelt out citation needed. Dam cat!--Aspro (talk) 19:08, 30 September 2016 (UTC)


 * This link] shows the different conduct velocities (CV) within the human body.


 * This link []shows the relation to nerve fibre diameter and CV for several species.


 * This link is to a very interesting paper on conduction velocity in different sized animals. On of their conclusions is "The time it takes to respond to stimuli will be much longer in larger animals." So, it is possible that primates smaller than humans will respond more quickly than ourselves. DrChrissy (talk) 19:51, 30 September 2016 (UTC)


 * yes i mean what you call reaction time. This is typical pseudo science pretension,(Although I don't think DrChrissy is phony or intending to be pretentious)) where someone makes a big deal about different meanigs in ordinary english and the english used in a specialty. Usually the situation is so bad that the ordinary english meaning came first, and was prevalent, but then the hoitytoities come along and say that's not wht it means, and the real meaning is their specialty meaning. For an example that has gone on so long weve even forgotten to be annoyed about it, I think "number" used to mean, in ordinary english, an integer greater than equal to 2. But "number" got hijacked by mathematicians, and now you're considered dumb if you say that 0, -1, 1+i*rt3 aren't numbers. One can see survivals of the everyday english "number" in the specialty Number Theory and also the common phrase "I have a number of friends in Seattle." if Im wrong on this example, it doesnt matter, there's plenty more out there.144.35.45.84 (talk) 20:32, 30 September 2016 (UTC)
 * This is a science reference desk. Like all aspects of science, Biology has developed its own technical language which we use to draw distinctions.  You are using a layman's interpretation of a term which in Biology has a specific meaning.  I was simply trying to clarify.  Thanks very much for your "thanks" for the time I spent in researching this for you - next time I will think twice. DrChrissy (talk) 20:47, 30 September 2016 (UTC)
 * The special meaning of reflex in physiology was coined by Dr Marshall Hall in 1833, but the word was subsequently used "More widely [to mean] an automatic, habitual, or instinctive action or response." (OED).   D b f i r s   11:54, 1 October 2016 (UTC)
 * I was using the word as it used in Ethology, which is the subject of the question. DrChrissy (talk) 18:11, 1 October 2016 (UTC)

Hey Dr. Chrissy, don't forget that lots of other people apart from the OP read these questions and answers, and I'm sure they all appreciate people with your specialist knowledge putting effort into these answers! (As I do). Keep up the good work.49.197.15.137 (talk) 07:32, 2 October 2016 (UTC)
 * Thank you - very much appreciated. DrChrissy (talk) 18:19, 2 October 2016 (UTC)
 * Speaking of precision in science, the term is usually spinal cord, not spinal chord, though there obviously are words where the distinction blurs, such as chordate. Matt Deres (talk) 15:25, 3 October 2016 (UTC)
 * Thanks for that. This is one of those words that I struggle to remember the spelling, and I checked this in my brain using "chordate".  Oh well, back to spellink skool. DrChrissy (talk) 18:39, 3 October 2016 (UTC)
 * Spinal chord, a synonym for backbeat? ←Baseball Bugs What's up, Doc? carrots→ 23:41, 3 October 2016 (UTC)

Where is the study that says that cardio does not build muscle?
So many people seem to be convinced that cardio exercises don't build muscle. I ride my bicycle frequently, and I notice that I am getting stronger, because going upslope is getting easier. When I move to a higher gear, it takes more work, but I eventually can ride my bike up there too. If that's not muscle, then I don't know what is. There must be a reason for the widespread belief that cardio exercises don't build any muscle. 140.254.77.228 (talk) 14:23, 30 September 2016 (UTC)
 * This article cites a meta-study of 14 other studies which shows that cardio workouts DO build muscle growth. I cannot find a study which shows the opposite, though just about any article I can find which cites the actual data notes the widespread belief you note; however any article I have found which states that cardio does not build muscle cites no data or studies themselves.  Perhaps someone else may find conflicting data.  -- Jayron 32 14:54, 30 September 2016 (UTC)
 * Colloquially, when people say "cardio", they generally mean an activity that primarily engages the cardiovascular system for a prolonged, relatively uninterrupted time. Many of these activities will build some muscle, since you can't "disconnect" your heart and lungs from the rest of your body: in your case, you're building muscles in your legs and back. However, the cause of the muscle growth isn't increased cardiovascular fitness, but your bodies' response to the overloading of those muscles: eventually, you'll reach a point where your muscles aren't overloaded, and then you won't build any more without additional resistance (such as leg weights). OldTimeNESter (talk) 18:59, 30 September 2016 (UTC)
 * I think that's just your body adapting to the changing environment. 140.254.77.175 (talk) 19:58, 30 September 2016 (UTC)
 * ...but you choose what that environment is. See Aerobic exercise and Anaerobic exercise. If you train for marathon running your body will change in specific ways, whereas if you train for power lifting your body will change in other ways. --Guy Macon (talk) 20:33, 30 September 2016 (UTC)


 * I've often have heard people say this, but they make that point about cardio burning a lot of energy which can come at the expense of the ability to build a lot of muscle mass. We're then talking about people who do strength training close to the limit of what their bodies will tolerate, who can barely eat enough to gain weight. They are then not going to run for an hour per day burning 1000 Kcal. To maintain cardio fitness they'll only do short bouts of interval training. Take e.g. Frank Medrano who is a vegan. He only does 15 minutes of high intensity interval training on 5 of the 6 workout days. Count Iblis (talk) 20:44, 30 September 2016 (UTC)

Is the antibiotic Magainin is already in used?
I was read in a chemistry book (from 2008) regarding to this antibiotic: "It has passed Phase I human trials. If this compound passes all remaining tests, it will be used in treating deep, infected wounds and ulcers, providing alternative to traditional therapy". So the quote is from 2008, and I read the article Magainin which doesn't sully information about it. I would like to know if it's already in use or not. 93.126.88.30 (talk) 19:41, 30 September 2016 (UTC)


 * Based on Google, the answer seems to be no.   Locilex, a magainin containing topical creme has thus far repeatedly failed to earn FDA approval, though they initiated new trials recently.     Apparently, at concentrations which are generally safe for humans, there have been concerns that it may not be very effective in its intended application.  Dragons flight (talk) 20:47, 30 September 2016 (UTC)


 * [ec] It was rejected by the FDA. See [ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1315844/ ] There has been recent talk about using it for neglected tropical diseases. [ http://www.mdpi.com/1420-3049/20/8/15392/pdf ]. --Guy Macon (talk) 20:54, 30 September 2016 (UTC)


 * Anecdotally (from when I worked at Eli Lilly in the nineties/noughties) it typically takes about 10 years to get a candidate molecule from discovery to market, and 9 out of 10 candidates that reach Phase 1 subsequently fail somewhere along the way. The full process also typically costs over half a billion US$ per drug, and the resulting commercial product has to cover not just this, but also around the same total costs involved in the 9 failures: this is part of the reason why non-generic drugs seem so expensive. See Drug development (note that the timeline shown there does not start at candidate molecule discovery). {The poster formerly known as 87.81.230.195} 90.202.211.191 (talk) 09:55, 1 October 2016 (UTC)

Science of relationships
From a scientific perspective, is sexual attraction a necessity for a long term relationship and why? Why are there certain types of relationships where the 2 people involved find each other's personalities and even looks attractive but yet they're not attracted to each other sexually? What is the scientific explanation for this? 2A02:C7D:B942:B800:1036:5A7E:4A72:BDE2 (talk) 20:32, 30 September 2016 (UTC)


 * See our article on Asexuality. --Guy Macon (talk) 20:35, 30 September 2016 (UTC)


 * People raised together have a natural aversion to sexual relations with each other, and this appears to be an evolutionary adaptation to increase genetic diversity in offspring. See Platonic relationship.  (We apparently lack an ability to distinguish who is genetically related to us, though, so siblings raised apart may well be sexually attracted to each other.) StuRat (talk) 23:26, 30 September 2016 (UTC)


 * That's not exactly true. There is plenty of evidence for kin recognition in humans, for example, see here. DrChrissy (talk) 21:10, 1 October 2016 (UTC)


 * Human love is complex. Read about Freddie Mercury's personal life, for example. ←Baseball Bugs What's up, Doc? carrots→ 02:15, 1 October 2016 (UTC)


 * I think anything that promotes the interests of survival and/or reproduction is scientifically defensible. Bus stop (talk) 20:53, 1 October 2016 (UTC)
 * Isn't that rather circular. If we know that something promotes survival an/or reproduction, this will have been tested by scientific methods. Therefore, of course it will be scientifically defensible.  It is more interesting to ask questions about characteristics that do not appear to enhance survival and/or reproduction.  However, I think this is getting off the point of the thread. DrChrissy (talk) 22:43, 1 October 2016 (UTC)
 * Well, the OP can weigh in to clarify the question. "[I]s sexual attraction a necessity for a long term relationship and why?" It is posited that "2 people involved find each other's personalities and even looks attractive but yet they're not attracted to each other sexually". How can they "find each other's personalities and even looks attractive" and not be sexually attracted to one another? That is a contradiction right there. "Attractive" doesn't equal "attractive"? Bus stop (talk) 23:13, 1 October 2016 (UTC)
 * Yes, the question is unclear. It could be argued that heterosexual male-heterosexual male friendships show that sexual attraction is not a necessity for a long term relationship. DrChrissy (talk) 23:26, 1 October 2016 (UTC)

Ion transport number and activity coefficient
Can a relation between ion transport number and activity coefficient be established? What aspects could be involved in deriving such a connection?--82.137.8.46 (talk) 23:38, 30 September 2016 (UTC)

Does the second law of thermodynamics apply to cosmology (or general relativity)?
We already know energy is not conserved in general relativity, meaning the first law of thermodynamics does not apply. So why should the second law apply, as would seem to be implied by heat death of the universe and black hole entropy? PeterPresent (talk) 23:52, 30 September 2016 (UTC)
 * Regarding you presumption, it's not that simple. This here has a good overview.   This also explains why it's a matter of perspective.  -- Jayron 32 02:48, 1 October 2016 (UTC)


 * Note that the reason (integral/total) energy(-momentum) conservation fails in GR is not that the energy can change, but that it can't even be defined, because the stress-energy tensors at different spacetime points belong to different tangent spaces and can't meaningfully be added. (This is explained in Jayron's first link.) I.e., the obvious generalization from SR fails. But there are at least two good reasons to think that some working generalization exists: 1. you apparently can't build a gravitational perpetual motion machine, and 2. unitarity seems to require global energy conservation.
 * I think that this is an unsolved problem, with important implications for quantum gravity. I don't know anything about the second law in GR, but some form of it clearly operates at cosmological scales, and the correct formulation may similarly be unknown. -- BenRG (talk) 06:57, 1 October 2016 (UTC)