Science desk
< February 9	<< Jan \| February \| Mar >>	February 11 >

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.

February 10

Parenteral nutrition as a supplement for athletes?

Can athletes benefit from getting massive amounts of nutrients via parenteral nutrition so that they can be fed much more than their intestines can process? Long endurance runner or a cyclist could then exercise much harder and burn a lot more energy because they're fed overnight via IV while their bowels are getting a rest too. Count Iblis (talk) 05:02, 10 February 2018 (UTC)[reply]

I seem to recall this discussion from almost a decade ago in which I seemed to recall "research into intense super-nutrition, sugar-syrups, and so forth," with sources cited.

Nimur (talk) 05:34, 10 February 2018 (UTC)[reply]

They might even be fed while running or cycling. But that must not be very common because when I googled "Parenteral nutrition athletes" the only thing I found was this which is not actually about athletes using parenteral nutrition to enhance performance but about modifying parenteral nutrition for an athletic competition in a person who already had to use Home Parenteral Nutrition (HPN) for a medical condition and who wanted to take part in a marathon. As to your original question, note using parenteral nutrition is not risk free: see Complications. So any advantage would have to be balanced against the risks. There's also the question whether that would be considered to be "doping". I don't think so, but I don't know. Basemetal 05:42, 10 February 2018 (UTC)[reply]

Here's an archive webpage on MIT Daedalus: "Like other well-conditioned cyclists tested for the job, the pilot’s body had an unusual ability to process oxygen. En route, to bolster performance, he carried and consumed huge quantities of a drink specially developed to replenish depleted blood with fluids, salt, and glucose." Nothing suggests parenteral ingestion, but he was basically getting many times more calories than a normal person by drinking some kind of home-made sports-drink.

Nimur (talk) 05:55, 10 February 2018 (UTC)[reply]

Ever heard of the Intralipid affair in the 1991 Tour de France? The PDM team used this method, but the stuff hadn't been stored cold enough, leading to infection. The entire team had to abandon the race. Although the team tried to keep it a secret, the method was legal back then. Probably other teams used it too. Nowadays IV feeding has been banned in cycling. So, yes, it can be considered doping. PiusImpavidus (talk) 19:07, 10 February 2018 (UTC)[reply]

Thanks everyone, so this is a no-go area, at least for athletes who don't want to violate the doping rules. Count Iblis (talk) 19:17, 11 February 2018 (UTC)[reply]

Disinfectants that don't burn

Are there alcohol-free disinfectants that don't cause a burning sensation on a wound or when rinsing in a mouth? I see our article lists several of them, but don't know which don't burn. I'm particularly interested in those that could be both a mouth rinse and wound-compliant. And does the absence of alcohol lower the efficacy of a disinfectant? Thanks. 212.180.235.46 (talk) 08:43, 10 February 2018 (UTC)[reply]

This is a very hard specification to achieve -- the very nature of disinfectants require them to be highly reactive compounds (which pretty much ensures that they will burn!) That said, silver compounds might fit the bill. FWiW 2601:646:8E01:7E0B:0:0:0:64DA (talk) 12:05, 10 February 2018 (UTC)[reply]

See medical uses of silver for more information, noting the associated risks. Mikenorton (talk) 14:44, 10 February 2018 (UTC)[reply]

Chloroxylenol is less aggressive when diluted down. Thus, it is used as a clinical disinfectant. Aspro (talk) 13:45, 10 February 2018 (UTC)[reply]

They are not disinfectants, but irrigation agents like saline can perform some of the same actions (by washing away germs rather than killing them) while not being irritating. For example, hypertonic solutions have been used to reduce bacterial count when used as an oral or nasal rinse. Again, not the same thing as disinfection, but warm saline is actually pleasant in most applications. Matt Deres (talk) 13:53, 10 February 2018 (UTC)[reply]

@ Matt Deres. Chloroxylenol is classed a both a disinfectant and antiseptic. Which is why I suggested it. Read the link above. Aspro (talk) 14:11, 10 February 2018 (UTC)[reply]

@ Aspro Is there some reason you're addressing that to me? I am not the OP and my post had nothing to do with yours. Matt Deres (talk) 14:45, 10 February 2018 (UTC)[reply]

@ Matt Deres. You posted above “They are not disinfectants”. Some are both. Aspro (talk) 15:58, 10 February 2018 (UTC)[reply]

@ Aspro You misread that - the "they" refers to "irrigation agents like saline" - which are not disinfectants. The indenting of the comment makes it clear that the reply is to the original question, and not to your previous reply. Wymspen (talk) 18:18, 10 February 2018 (UTC)[reply]

Bactine used to be advertised as an antiseptic that didn't burn when applied to a wound, for what that's worth. I wouldn't use it in my mouth, myself, though. Deor (talk) 14:20, 10 February 2018 (UTC)[reply]

What you want is not a disinfectant, but an antiseptic. Disinfectants are not intended for use on living tissues, although some substances can be used both as a disinfectant and as an antiseptic. --98.115.54.114 (talk) 15:28, 10 February 2018 (UTC)[reply]

Betadine never stung. Edison (talk) 18:34, 10 February 2018 (UTC)[reply]

I've been prescribed chlorhexidine mouthwash by my dentist, and it doesn't really seem to "sting" to me. It does leave a bit of a bad aftertaste for a while. Chlorhexidine is also used topically, though in the U.S. it's prescription-only. Unless you're using neat alcohol itself as a disinfectant (which, as implied, is not pleasant to use on wounds), the presence of alcohol has nothing to do with the disinfectant properties. It's used as a solvent, for example in mouthwash. For external minor wounds, it looks like the best thing is good old soap and water, followed by petroleum jelly to seal the wound. There's no evidence that any topical disinfectants have any benefit for minor wounds, and they can cause side effects. See Wound#Management. As should go without saying, if you have chronic mouth ulcers or something of the kind, consult a medical professional. --47.146.60.177 (talk) 08:51, 14 February 2018 (UTC)[reply]

Actually, I now notice the chlorhexidine article says "US: OTC", without a source. I know the mouthwash is prescription-only, but I don't know about other preparations. --47.146.60.177 (talk) 08:56, 14 February 2018 (UTC)[reply]

Cornflakes / popcorn

Apparently both of these are made from varieties of maize. When popcorn pops, it becomes a fluffy ball. Is a "cornflake" one seed/pod/lump from a maize corn and what has been done to it to make it "flat"? -- 86.152.226.243 (talk) 20:15, 10 February 2018 (UTC)[reply]

Please, read here. Ruslik_Zero 20:40, 10 February 2018 (UTC)[reply]

Kellogg started out looking find a product that would make him rich (it was that simple). He also had the then-fashionable faith in 'whole grain' foods as the key to health. The inventor of Shredded Wheat was originally an engineer and had started out trying to sell the machine for making it (a combination of roller and oven - the process is to cook a milled grain, mill, roll into sheets, then bake as flakes), rather than the product; Kellogg had bought one, was certainly aware of "baked cereal flakes" as a breakfast concept, but wanted to play up the 'whole grain' aspect. So he changed the process to use maize. He also played up the Midwestern cornhusker schtick with artfully draped Ceres figures waving stalks of Good Ol' US-of-A maize on the box. You need a kernel with good starch content, as big as you like, and you don't care about the husk.

'Popcorn' needs to pop. So it needs a tough, pressure-proof husk and a starch filling which soften when cooked. You dry this to the tight moisture content, then sell it. When heated, the internal starch softens, the moisture content turns to steam and the pressure stresses the husk until it pops. Andy Dingley (talk) 21:40, 10 February 2018 (UTC)[reply]

(e/c) Popcorn is the unusual one; its hard endosperm allows pressure to build up inside the kernel, allowing for the resulting explosion (the 'pop') to create the fluffy treat. Normal corn lacks that hard endosperm, so the pressure doesn't build, and the kernel just gets limp and cooks. Matt Deres (talk) 15:31, 11 February 2018 (UTC)[reply]

The simple answer is that they are made from different varieties of maize. The section titled "Genetics" has links to the various varieties. --Jayron 32 15:05, 12 February 2018 (UTC)[reply]

Land area to feed a person?

How much land does it take to grow the food I eat? I could divide the area under cultivation by population but I don't have the numbers and I don't think it's perfectly accurate even as an average. Thank you. RJFJR (talk) 22:13, 10 February 2018 (UTC)[reply]

Are you vegetarian? Are you using the latest technology or conventional farming? You could feed a person in a mere 1,000 m2 plot, if you abstain from pork and beef (maybe you can raise some chickens). Source: [1] --Hofhof (talk) 23:09, 10 February 2018 (UTC)[reply]

Thank you. That link as a source is 'page not found'. RJFJR (talk) 06:59, 11 February 2018 (UTC)[reply]

"Research in the 1970s by John Jeavons and the Ecology Action Organisation found that 4000 square feet (about 370 square metres) of growing space was enough land to sustain one person on a vegetarian diet for a year, with about another 4000 square feet (370 square metres) for access paths and storage – so that’s a plot around 80 feet x 100 feet (24m x 30m)". [2]

"Post WW2 Australian suburban lots were sized at 1/4 acre (1000 m2) in the belief that that is enough land for a family to be self sufficient in vegetables and small animals like poultry or rabbits". [3] Alansplodge (talk) 11:42, 11 February 2018 (UTC)[reply]

It's also generally a declining number as is the number of people necessary to grow feed. Only 250 years ago, the economy required 90% of the people to be farmers. Now it's less than 1% and food is quite a bit more abundant. Plants and animals have also been selected and bred for thousands of years to produce more efficiently. In just the last 50 years or so, chicken breeding has created specialized breeds for broilers and egg laying hens. A broiler is ready to be harvested in 6 to 9 months with very large, edible components making them much more efficient than in the past. Equipment has made it possible to sanitarily butcher and package them at the processing facility. 30-40 years ago, chickens were sold with everything but feathers because they couldn't butcher them in clean and cost effective way. this reduces the butchering footprint and you rarely see "Butcher shops" anymore. It also seems that starvation in the 1970's was a lot higher than today even though there was only half the current population. Food production has risen faster than population growth and this excess is reflected in lower pricing and obesity. --DHeyward (talk) 14:27, 11 February 2018 (UTC)[reply]