Wikipedia:Reference desk/Archives/Science/2017 August 1

From Wikipedia, the free encyclopedia
Science desk
< July 31 << Jul | August | Sep >> August 2 >
Welcome to the Wikipedia Science Reference Desk Archives
The page you are currently viewing is an archive page. While you can leave answers for any questions shown below, please ask new questions on one of the current reference desk pages.


August 1[edit]

Medical "treatment" of superstition[edit]

Have any studies been done within the framework of evidence-based medicine in which superstitions and religious beliefs which could drive a patient toward alternative medicine are treated as diseases, and where the relative merits of attempting to cure them (i.e. disabuse the patient of them) versus providing symptom relief (by administering placebos that play to the patient's superstitions) are investigated? NeonMerlin 07:26, 1 August 2017 (UTC)[reply]

Yes. There was at least one study, focused on vaccine treatment, which used various methods to get parents who supported vaccines to use alternative treatment for their children and get parents who opposed vaccines to start using vaccines for their children. The end result is that those who vaccinate their children were not greatly swayed by the propaganda while some methods did sway the antivac parents. The study was published last year. I will start searching for it and see if there are repeated or expanded versions of the study. I describe it here so you can start searching for it and possibly find it quicker. 209.149.113.5 (talk) 12:26, 1 August 2017 (UTC)[reply]
I was wrong. It was two years ago, not last year. This is one of the earlier papers on the study, which is ongoing [1]. 209.149.113.5 (talk) 12:29, 1 August 2017 (UTC)[reply]
While I would say that is a relevant and valuable source for the OP to see, note that it doesn't precisely align with what the OP was inquiring about. They seem to be looking for research that tackles the issue with a broader lens: not just whether or not patient beliefs can be changed, but the notion of treating superstition as an element of disease, and measuring it as an epidemiological factor. While I wouldn't be comfortable saying that nothing in that vein has been researched, I will say it's unlikely that there has been anything quite so on-the-nose as to have called superstition a disease, if only because research inquiries in the relevant fields tend to be a lot more precise and clinical, and not terribly metaphorical and implicative. Now in psychological research more broadly, there's plenty of research about the nature of superstitious belief and how it can manipulated or modified. But scientific studies looking at this from a the practical light of medical context are more likely to be like the above (i.e. postulating on how views can be effected, rather than making the case that they should, which is more the place of policy studies. The OP didn't specify one over the other, but from their question, I suspect they are looking for peer-review research. Snow let's rap 17:53, 1 August 2017 (UTC)[reply]

What is the best way to evaluate the purity of single walled carbon nanotubes?[edit]

Single walled carbon nanotubes are produced by various processes. When they are produced they have impurities such as other forms of carbon (amorphous carbon, fullerene, multiwalled nanotubes, etc.) and inorganic impurity (metal catalyst). How to evaluate the quality and the quantity of the single walled carbon nanotubes in the as-prepared single walled carbon nanotubes? — Preceding unsigned comment added by Anto Godwin (talkcontribs) 08:44, 1 August 2017 (UTC)[reply]

Did you consult this reference? [1]
  1. ^ Itkis, Mikhail E.; Perea, Daniel E.; Jung, Richard; Niyogi, Sandip; Haddon, Robert C. (March 2005). "Comparison of Analytical Techniques for Purity Evaluation of Single-Walled Carbon Nanotubes". Journal of the American Chemical Society. 127 (10): 3439–3448. doi:10.1021/ja043061w.

Graeme Bartlett (talk) 09:41, 1 August 2017 (UTC)[reply]

What are all the easy and effective ways to separate single walled carbon nanotubes into metallic and semi-conducting?[edit]

The as-prepared single walled carbon nanotubes always contain the mixture of both metallic and semiconducting nanotubes based on their diameter and chirality. What is the easy and effective way to separate them with low cost? — Preceding unsigned comment added by Anto Godwin (talkcontribs) 08:49, 1 August 2017 (UTC)[reply]

see [1] Graeme Bartlett (talk) 09:46, 1 August 2017 (UTC)[reply]
  1. ^ Voggu, Rakesh; Rao, K. Venkata; George, Subi J.; Rao, C. N. R. (28 April 2010). "A Simple Method of Separating Metallic and Semiconducting Single-Walled Carbon Nanotubes Based on Molecular Charge Transfer". Journal of the American Chemical Society. 132 (16): 5560–5561. doi:10.1021/ja100190p.

If a female goat is lactating and the human mother does not, then...?[edit]

Can the goat's kid be slaughtered and let the human child suckle on the goat's mammary glands? Will the milk work or just cause a stomachache and diarrhea? Can goats detect whether their kid is missing? 140.254.70.33 (talk) 13:23, 1 August 2017 (UTC)[reply]

Why go through all that hassle rather than just milking the goat? Iapetus (talk) 13:44, 1 August 2017 (UTC)[reply]
Dairy_farming#Lactation_Management deal with cows, but I believe goats would be similar. Basically, they'll keep producing milk for some time after they give birth so long as they're regularly milked. Whether or not they can actually see their calf is not a significant part of it.
Directly suckling a goat seems needlessly dangerous,(a kick to the head would put an abrupt end to that experiment.) and I'm not even sure it would work, (Can human babies create as much suction as a goat kid?) but it sounds like the milk would be sustaining, in the sense that some people do raise their babies on it, but dangerous in the sense that most medical authorities discourage it because it can cause some serious health problems. Goat#Nutrition
I guess in some sort of survival situation where there was absolutely no other source of milk, it'd probably be usable, seems like it's not advisable otherwise, though.
ApLundell (talk) 14:33, 1 August 2017 (UTC)[reply]
Why would someone have to when Infant formula exists? --Jayron32 14:50, 1 August 2017 (UTC)[reply]
I thought breast milk is healthier than formula. If so, then the proper alternative would be milk from a wet nurse. But would direct feeding of a human infant by a goat work just as well? How can goat milk be nourishing for goats but not humans? 140.254.70.33 (talk) 15:38, 1 August 2017 (UTC)[reply]
Unless the mother, for some reason, cannot breast feed (which happens in a LOT of cases), at which point formula is better than starvation. There's a major problem with women being shamed for not breast feeding; some women simply cannot and should not be shamed for not being able to, and formula provides the best alternative. Cow's milk and goat's milk by themselves, which lacks many unique ingredients important to human development, are not great substitutes. So yes, breast milk is ideal. No, women who use formula, for whatever reason, are not doing anything wrong. Formula is better than other mammalian milk. --Jayron32 16:49, 1 August 2017 (UTC)[reply]
I agree with you on your second sentence and was actually thinking the same thing (but didn't mention it because at the time just after your first reply it didn't seem relevant). Notably, someone once told me of a couple who found it very difficult to get good information about formula feeding and this was in New Zealand, a developed country with a massive dairy industry and I'm fairly sure at least one of the partners was either a scientist or doing a PhD in biological sciences. That said, having grown up in Malaysia at a time when it was still normal to watch broadcast TV live and therefore have to watch the advertisments, I can also understand the concerns over excessive formula promotion. It was extremely normal to see various baby foods and formula promoted as wonder foods for brain development etc. IIRC these were generally formulas for post weaning feeding (and of course likewise with the foods) probably since this was after the controversy and Malaysia did have some degree of restrictions in accordance with international trends but the implications of these ads were clear. Unfortunately rightful concern over these practices seems to have gone way too far in the reverse. That said, while formula is always likely to be better than goat's milk assuming there is access to clean water, I guess there are probably a tiny number of scenarios where people either don't have access to formula or don't have access to clean water are unable to breast feed sufficiently and don't have access to a wet nurse or similar, but may have access to goat's milk. I can't however imagine any scenario where it would make sense to get an infant to suckle a goat. Nil Einne (talk) 15:44, 2 August 2017 (UTC)[reply]
Obviously... That was self-evidently stupid enough that I didn't feel the need to treat it as a serious proposal. --Jayron32 16:11, 2 August 2017 (UTC)[reply]
Cow's milk has very different composition from human milk - the whole reason why 'formula' has a formula is because of the differences. That said, formula is not a great substitute and it still isn't known why - I cannot say for sure that goat milk or the process of physically sucking it wouldn't provide the infant with some benefit otherwise lost by switching from breast to formula. Wnt (talk) 16:06, 1 August 2017 (UTC)[reply]
Milk is going to vary depending on the health and genetics of the mother. The notion that mother's milk is "always" better is a myth. ←Baseball Bugs What's up, Doc? carrots→ 16:07, 1 August 2017 (UTC)[reply]
You might as well ask why any form of organic matter can be nutritious for one species and potentially dangerous for another; in short, human children are adapted for human milk. There are almost certainly comparative studies comparing the make-up of human milk and that of our most often milked domestic species (I couldn't find the right references in a couple minutes of searching, but will give it another shot later), but to answer your question in the simplest terms now, the problem is two-fold: A) an insufficiency/imbalance of the correct macronutrients necessary to fuel the development of the child, as well as constituents of milk necessary to early health (the colostrum in particular is very helpful in the development of the immune system) and B) an overabundance of other elements a human child does not generally get from breastfeeding: this may be as simple as an imbalance of macronutrients, or (depending on the species) possibly even toxicity issues. There's also the matter of parasites and pathogens; the offspring will have spent 9 months (in the case of humans) gestating inside their mother, on average, acquiring immunities from her, and even then will not have a particularly well developed immune system at birth, so being exposed to a source of unpasteurized milk from a different species is not a great idea. On the whole, just not a smart replacement. But, it seems to me that I have heard of this having been done in, historically, in the middle ages, under dire circumstances, specifically with a goat. If memory serves, QI did a segment on it. Snow let's rap 16:27, 1 August 2017 (UTC)[reply]
Ah, could not find the clip, but here we are. 18th and 19th centuries, as it turns out. Snow let's rap 16:32, 1 August 2017 (UTC)[reply]
Fear Factor, for your amusement. [2] In those pre-Nick Berg days Errrm, I mean pre-post Nick Berg days..., it was right around then that I realized video entertainment was getting completely debauched. ;) Wnt (talk) 16:03, 1 August 2017 (UTC)[reply]
What about feeding a human baby with an unrelated female (wet nurse)? 140.254.70.33 (talk) 20:29, 1 August 2017 (UTC)[reply]
Wet nurse. Blooteuth (talk) 21:26, 1 August 2017 (UTC)[reply]
See also Human milk bank.--Shantavira|feed me 08:15, 2 August 2017 (UTC)[reply]

What's the highest octane rating liquid known? (AKI)[edit]

Not the inflated rating where (made up numbers) 100% X is 100 octane and 10% X mixed with 90% 90 octane gas is 91.5 so they say X is 105 octane. Is it some weird compound with obscene amounts of lead additive(s)? What's the highest octane non-mixture? Sagittarian Milky Way (talk) 19:40, 1 August 2017 (UTC)[reply]

Many of the simple gaseous fuels (i.e. methane) are higher octane than any credible liquid. As an easily available liquid, then toluene is 121 RON and used to be used for engine research (but toluene has a bad reputation these days), isopropanol (118 RON) is used instead. As a usable racing fuel, methanol is 109 RON. I don't think that unobtainium esotericide goes noticeably above these. Andy Dingley (talk) 20:00, 1 August 2017 (UTC)[reply]
In the octane rating article the only thing listed with a higher RON than toluene is hydrogen (at more than 130), but I doubt it would be feasible to build an engine using it in liquid form. Wymspen (talk) 21:52, 1 August 2017 (UTC)[reply]
Just use gas injection like millions of LPG or propane engines. BMW built a hydrogen IC engine.Greglocock (talk) 22:03, 1 August 2017 (UTC)[reply]
FYI, I have read that triptane has an incredible octane rating of 225, but is too expensive to be produced in quantity. 2601:646:8E01:7E0B:FCEE:E7DF:4CAD:C2E5 (talk) 04:11, 2 August 2017 (UTC)[reply]