Wikipedia:Reference desk/Archives/Science/2013 August 9

= August 9 =

Stages
Is this sentence scientifically correct? "First we are gametes, then zygotes, then embryos, and then fetuses." Pass a Method   talk  00:24, 9 August 2013 (UTC)
 * The sequence is correct, but gametes are haploid organisms, and no gamete is genetically identical with any person, all of whom are diploid organisms. See also alternation of generations in plants for comparison. μηδείς (talk) 01:39, 9 August 2013 (UTC)
 * You could say we start out as two gametes, but that's only retroactive to them having merged. ←Baseball Bugs What's up, Doc? carrots→ 02:26, 9 August 2013 (UTC)
 * Gamete Jim, I'm a doctor, not a zygote. Clarityfiend (talk) 02:56, 9 August 2013 (UTC)
 * There also is the problem of "we". If you talk about personal identity, you (may?) need a consciousness, which means that we only slowly form during development, and certainly don't exist at the zygote level (unless you assume some religious perspective). --Stephan Schulz (talk) 09:44, 9 August 2013 (UTC)
 * I can't speak for the OP, but I'm talking strictly biology. If you want to take it ever farther back, you'd have to look at what precedes the gametes, i.e. the process that creates them. Then you could say we start out as molecules within our parents' reproductive systems. And so on, clear back to the first strand of DNA that ever existed. I'm reminded of one of my favorite Carl Sagan quotes, from Cosmos: "If you wish to make an apple pie from scratch, you must first invent the universe." ←Baseball Bugs What's up, Doc? carrots→ 13:25, 9 August 2013 (UTC)
 * I take your point. Another way of looking at the question of "when does life begin?": Though some governments and religions like to quibble over the details of pregnancy and fetuses, the biological answer is ~3.5 billion years ago. SemanticMantis (talk) 15:00, 9 August 2013 (UTC)
 * If a zygote is a person that can be made of two cells, why can't two gametes be a person, either before or after fusion? Indeed a zygote might work out to be a pair of identical twins... Wnt (talk) 17:42, 9 August 2013 (UTC)
 * Technically the zygote is only the single fertilized egg cell. Before fusion gametes are two discrete haploid organisms incapable of mitosis on their own or any function we attribute to persons.  (I may be misunderstanding you, because I am otherwise surprised by your question, given the amount of medical questions you answer.) μηδείς (talk) 18:07, 9 August 2013 (UTC)
 * It's a little like looking at a pile of bricks and calling it a building before it's actually built. ←Baseball Bugs What's up, Doc? carrots→ 23:15, 9 August 2013 (UTC)
 * Whoops, sorry - bad edit. I'd planned an "after it divides" in some overwrought prose at one point.  I mean a two-cell embryo. Wnt (talk) 22:52, 10 August 2013 (UTC)

Whey protein
Why is there research showing that whey protein decreases cancer risk and also research showing it increases it. This is contradictory. Clover345 (talk) 10:08, 9 August 2013 (UTC)


 * I am not surprised - the idea that scientific research always produces clean, easily interpreted and consistent results is an over simplifcation. There are many reasons why valid studies could produces apparently contradictory results. Maybe there was some important difference in the groups being studied or the study methods that was not accounted for (dosage, age, gender, diet, lifestyle etc. etc.). Maybe there was some external factor that was not controlled for. Maybe the baseline risk was underestimated or overestimated. Maybe the results in one or both of the studies were due to random coincidence. The appearance of contradictory results suggests that we do not yet have a complete or accurate model of the interaction between whey protein and cancer risk, and so further research is required. Gandalf61 (talk) 10:53, 9 August 2013 (UTC)


 * With foods that claim to improve health in one manner or another, there is a serious issue with companies who sell such things as "Nutritional supplements" (which are largely unregulated by the FDA) - they need to make their product look beneficial, and very often fund dubious research to produce that goal.


 * Since you didn't link to the paper(s) that you saw, we can't know whether that's the case here and this might be very carefully done and accurate research - but I strongly suggest you look back at the favorable papers and ask yourself whether they were funded in this manner - whether the journals they were published in are peer-reviewed, whether the researchers involved only produce favorable reports about food supplements and so forth.


 * That kind of double-check is always a good thing to do with any scientific paper - but in the special case of reports that claim beneficial health outcomes from processed food products, you have to have your "bullshit" meter dialled up to 11.


 * SteveBaker (talk) 13:37, 9 August 2013 (UTC)


 * The old saying still applies: "Follow the money." If someone claims something about something, first find out what they have to gain by someone buying that something. ←Baseball Bugs What's up, Doc? carrots→ 13:59, 9 August 2013 (UTC)


 * Yes, along the same lines as what Gandalf61 said. Without reference to the accuracy of any specific study it is totally logical to assume that under certain circumstances adding whey protein to a persons diet may either raise or lower the risk of certain cancers. Also the composition of different whey protein products varies depending on factors such as heat treatment which may destroy certain beneficial components such as immunoglobulins. 122.109.123.252 (talk) 16:52, 9 August 2013 (UTC)

Placebo and nocebo effect
Are placebo and nocebo effects linked to stress? Could it be that the reason placebo pills work is because it puts the mind at ease and relieves stress? If so, could other psychological effects affect physical health? For example, could the simple thought of pain going away cure it just as a placebo would? And could the opposite also be said? Clover345 (talk) 14:57, 9 August 2013 (UTC)


 * The mechanism is discussed in Placebo and Neural top down control of physiology. SteveBaker (talk) 16:36, 9 August 2013 (UTC)


 * Yes, stress could be a factor. Also, for subjective measures, like "how much pain do you feel", people can experience the same amount of neural activity, measured objectively, as less pain.  Placebos are less effective when objective measures are applied. StuRat (talk) 06:20, 10 August 2013 (UTC)


 * Reading that section in the article on the placebo effect, I think it misses something that I've observed. A friend of mine who is into alternative medicine for his complaints sometimes tells me how well he has been helped. But if you listen to his complete story, you can't help but notice the following effect. Suppose that you have some illness and you are inclined to reduce your physical activities, not eat as much as a result, stay in bed longer etc. etc. However, because you are now getting pills, you are more optimistic, so you decide to do more during the day. Then, for certain complaints simply being a bit more active compared to behaving like you are ill, can have apositive effect, apart from simply reducing stress. Count Iblis (talk) 13:33, 10 August 2013 (UTC)

How long after eating does "take with meal" not apply
I hope this doesn't fall under the guise of "medical advice", because I'm just curious about digestion. I notice some vitamins and medications instruct the person to "take with meals". What's the time window for that period? How long after eating would be considered too late to take something "with meals"? What biochemical actions (relative to ingested pills) take place "with meals"? --157.254.178.141 (talk) 17:21, 9 August 2013 (UTC)
 * On average, the stomach takes about 1 hour to empty its' contents into the small intestine. Reasons to take with meals include better absorption of the drug (as with vitamins) or avoiding upset from an irritating drug. If this is a prescription drug you can call your pharmacist, they enjoy answering such questions.  If its' over the counter there will be a toll-free customer service number to call. μηδείς (talk) 17:57, 9 August 2013 (UTC)


 * No apostrophe is needed after its to indicate possessive. See . Edison (talk) 20:51, 9 August 2013 (UTC)
 * Channeling Cuddlyable3??? ←Baseball Bugs What's up, Doc? carrots→ 23:13, 9 August 2013 (UTC)
 * Shes' been' making' some' sort' of' weird' point' for' quite' some' time' now'. See' below' @ whats'  and' OPs' .  --   Jack of Oz   [pleasantries]  23:46, 9 August 2013 (UTC)
 * It's certainly a dangerous path to tread. We've already determined that spelling/grammar/punctuation complaints constitute "disruptive editing" here on the Ref Desks.  The fate of Cuddlyable3 and his oh-so-cuddly socks clearly demonstrates that one should not go there. SteveBaker (talk) 14:53, 10 August 2013 (UTC)
 * Maybe one of you can link to the original discussion which got CuddlyAble3 blocked? It seems to have been before my time. Tis hard to believe a misplaced apostrophe alone was the cause. Thanks. μηδείς (talk) 20:33, 10 August 2013 (UTC)

Dog reproduction
Hi. My aunt's bitch just gave birth to a litter and she gave me two puppies, a boy and a girl. I was wondering: if I raise them at home and keep them away from any other dogs, once they get to reproductive age, will they mate with each other? Thanks. 24.92.93.248 (talk) 17:43, 9 August 2013 (UTC)
 * Yes. I am not sure where one would look for a source, but yes. μηδείς (talk) 17:59, 9 August 2013 (UTC)
 * I would want to see a reference for that. In many species, individuals avoid mating with other individuals that they spend a lot of time with when young.  I can't spot any information directly about dogs, though. Looie496 (talk) 18:07, 9 August 2013 (UTC)
 * Animal_sexual_behavior says that incest is common in foxes - referenced to a document that relates to DNA investigations. Incest says that "Many mammal species including humanity's closest primate relatives tend to avoid close inbreeding, especially if there are alternative partners available." - suggesting that animals will actively seek to mate outside the litter if they can - but if not, then incest is OK.  If you think about it without viewing the behavior through human morality, that's the most evolutionary sound approach.  Faced with the choice of not passing on DNA to the next generation at all - or risking some small reduction in genetic variation in the next generation - the evolutionarily "correct" answer is to do exactly as our article suggests.  So, in the absence of any other evidence - I'd answer this question with a pretty solid "YES!" SteveBaker (talk) 18:20, 9 August 2013 (UTC)


 * Here are two refs that that discuss inbreeding avoidance in canines: one for African wild dogs, here, and one for Ethiopian wolf, here . Both seem to conclude that there are inbreeding-avoidance mechanisms at work, in line with Looie's comments above. But who knows how domestication messes with these instincts? Here's at least one vet who says that littermates will mate . I suspect that the answer is that littermates of domestic dogs would tend to not mate with eachother, if other mates are available. But, if the only option is a sibling, they'll likely go for it. Really, unless they have some plans of being a dog breeder, the OP should spay and neuter their pets. SemanticMantis (talk) 18:27, 9 August 2013 (UTC)


 * The OP has specified that the dogs will be kept together away from other dogs. In that case there will be no other dogs for them to prefer, and they will settle for whats' available. μηδείς (talk) 18:31, 9 August 2013 (UTC)


 * When a female dog goes into heat, she and potential partners have an amazing ability to go over, under, or through barriers set up by humans. "Keeping them away from other dogs" is a strategy which would require exceptional diligence to prevent breeding with "other dogs." omnia vincit amor. Edison (talk) 20:48, 9 August 2013 (UTC)


 * That's quite true, I can attest from various litters I've midwived. But the OPs' entitled to his premises. μηδείς (talk) 22:03, 9 August 2013 (UTC)
 * At first glance I thought LC had moved to Wisconsin. ←Baseball Bugs What's up, Doc? carrots→ 23:12, 9 August 2013 (UTC)

Relative velocity?
For example if an object floats in space, covering several thousands kms per hour relative to Earth, but only several kms/h relative to itself, is it called relative velocity or something else? (in other words, when that object travels somewhat slowly relative to itself, but covers lots of territory relative to Earth)--93.174.25.12 (talk) 21:35, 9 August 2013 (UTC)


 * An object always has zero velocity relative to itself.  Spinning Spark  21:40, 9 August 2013 (UTC)
 * [ec] The object would appear motionless relative to itself. All speeds are relative (that is, it needs another point of reference to determine what the speed is, and that apparent speed can change based on a variety of factors. If you were in a car travelling 60, a vehicle coming towards you at the same speed relative to the road appears to you to be moving faster than one passing you at 65, which would be passing relative to you at only 5) If you mean that the acceleration is comparatively slow, that's a different thing. It sounds confusing because on human scales, it is confusing. Mingmingla (talk) 21:52, 9 August 2013 (UTC)


 * As Einstein pointed out - all motion has to be measured relative to something else. Here on earth, it's easy to forget that and just measure all velocities relative to the earth.  So when that cop accuses you of driving faster than 70mph - you should be able to say "But officer, I was travelling at only 10mph relative to that truck just behind me" and thereby be let off getting a ticket.  (Please don't try that!)  Sadly, that doesn't happen because we all naturally assume the earth itself as the basis for "absolute" velocity measurements.   However, that's just a local convention - it's not backed by any particular laws of physics.  We read that the Apollo Lunar Rover was driven at up to 8mph...but that was relative to the moon.  Taken relative to the Earth, it was zipping along at 2,200 mph.


 * So our human perception of "absolute speed" depends on some kind of spoken or unspoken "reference frame". For your object that's just floating out in space - there is no "obvious" object to use as a reference - so it's meaningless to talk about speed.  If you say "relative to itself" - then the answer must be zero because an object can't move away from itself.  Unless you're either implicitly or explicitly saying "relative to earth" or "relative to the sun" or "relative to that empty coke can that the astronaut just tossed out of the window" - you can't say anything meaningful about the velocity of your object out there in space.


 * SteveBaker (talk) 14:45, 10 August 2013 (UTC)


 * This is a very popular platitude, soundly based in the theory of relativity, and yet... there are virtually no macroscopic objects whizzing around the nearby universe moving at relativistic velocities relative to us. And the cosmic microwave background, etc. Wnt (talk) 22:49, 10 August 2013 (UTC)
 * There are no macroscopic objects moving at relativistic velocities relative to us because of the ungodly amount of energy it would have taken them to get them moving that fast relative to us. Even if there were objects moving that fast relative to us - they'd be gone and out of sight before we'd have a chance to detect them!  I have no idea why you're mentioning the cosmic microwave background - what relevance does that have to this question. SteveBaker (talk) 02:49, 11 August 2013 (UTC)

triple / triangle of life in emergency
In Israel there is an emergency term (generally used by resque teams or paramedics) which is called: "triangle of life" (משולש החיים). This term refers to three important sistems of the body: blood sistem, nervous sistem,breathing sistem. When one of them does not work, it endangeres the life and it can be caouse of death. My question is: Is there a same term in English? and Is there a same term in the other countries? I'm intrested to know what is the origin of this term` maybe its origin is in Israel and maybe not [I have red in Wiki about another thing which called "triangle of life", it referes to another issue entirely.] Thank you. מוטיבציה (talk) 22:03, 9 August 2013 (UTC)


 * This reminds me of the ABC's of medicine, which is commonly taught in first-responder courses in the United States. Here, it stands for "airway, breathing, circulation". Not quite the same as the triangle of life, but reminiscent. Someguy1221 (talk) 22:24, 9 August 2013 (UTC)


 * Hospital doctors refer to "vital signs". The primary vital signs are temperature, blood pressure, pulse, breathing rate.  Any primary sign below certain limits means that you are clinically dead or dying, and immediate action is required.  The secondary vital signs are sensitivity to pain and the reaction of the pupil to light.  Lack of these signs does not mean that you are dead or dying, but you are seriously ill or injured, and corrective action is required ASAP.  124.182.50.53 (talk) 01:48, 10 August 2013 (UTC)
 * Vital signs. Someguy1221 (talk) 03:13, 10 August 2013 (UTC)
 * In the USA, the term ABC for EMTs and Paramedics is sometimes expanded to ABCDE, which stand for airway, breathing, circulation, disability (that is, what is the main thing wrong with the patient that is readily visible) and expose (that is, remove any clothing necessary to accurately access the patient). Jc3s5h (talk) 02:29, 10 August 2013 (UTC)
 * ABC it's another thing which used also in Israel. I did not mean about the ABC (Airway, Breathing and Ches Compressions, no Circulation. circulation is in the protocol of trauma life support,there, there is ABCDE that the letter C is circulation. That's a freqence mistake to say circulation instead of chest compression in CPR). By the way, the schema is not yet ABC but CAB, according to updates of AHA- American Heart Association, that Israel emergency goes according to it. I meant in my question to triangle of life, not to ABC. and according to the answers I can guess that this term is not used in other countries in this meaning. מוטיבציה (talk) 09:58, 10 August 2013 (UTC)