Wikipedia:Reference desk/Archives/Science/2018 April 23

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April 23

How does solotone cause to strong smell through sweat glands?

I've read that "fenugreek contains an aromatic compound called solotone, which is responsible for the sweet-smelling "perfume" your sweat emits.". Now my question is how this compound arrive to the sweat glands in the armpit exactly? Is it by the blood or other way? 93.126.116.89 (talk) 04:14, 23 April 2018 (UTC)

That's sotolon, or sotolone, not solotone, which seems to be a woo-woo multi-vitamin supplement available in Nigeria. Sotolon is a lactone, so it would be absorbed in the small intestine and circulated in the blood. - Nunh-huh 04:49, 23 April 2018 (UTC)

Yes, the blood, the same way pretty much anything moves around your body. Some lipids do initially get dumped into lacteals instead of the blood, but the lymph returns to the blood eventually, so they still wind up there. Things you ingest only don't wind up in your general circulation if a) they aren't absorbed from your digestive tract at all, and therefore stay there and are excreted; b) if the liver (which is the first stop for blood coming from the digestive tract) stores, modifies, or excretes them back out via the enterohepatic circulation. This is a big deal for any medication taken orally, because the liver can modify it so it's no longer effective, in what's called first-pass metabolism. This is one reason why some drugs can't be or aren't ideally given orally—the other is because most large molecules, like peptides, get digested, which is why things like insulin have to be administered parenterally. --47.146.63.87 (talk) 09:12, 23 April 2018 (UTC)

It's an interesting question. Eccrine sweat glands work by a merocrine mechanism, which is to say, the vesicles that become sweat are filled inside cells (as opposed to transcytosis). That would appear to imply (assuming no specific transporters) that the lactone is able to cross phospholipid bilayers unaided, which given its structure seems pretty believable. In which case it might more or less suffuse the entire body, intracellular and extracellular, and all secretions from it. Wnt (talk) 12:27, 24 April 2018 (UTC)

For my grandfather.. planetary motion and ultimate conclusions

My great grandfather (of 91 years and still standing) would like to understand why with all the eccentric orbits of all the moons and planets around us, that we aren't going to be bereft of interplanetary cousins in due course. In other words, with the eccentric nature of everything stellar around us, why aren't we tending to see things move away (or closer) on a cosmic scale? The Rambling Man (talk) 22:10, 23 April 2018 (UTC)

Eccentricity simply means that the shape of the orbit is sort of like an "oval". Those "ovals" are still stable - they are not tending to eject, or decay, or collide.

In physics, we often find stability in complex systems: this branch of mathematics is frequently considered one of the most elegant and complicated branch of mathematics.

Nimur (talk) 23:42, 23 April 2018 (UTC)

The long term stability of the solar system is an active area of research, in large part because it is a very difficult problem to solve. Exact solutions regarding the stability of planetary systems have only been achieved for relatively simple theoretical systems, such as one-star two-planet systems. Most everything else gets simulated due to complexity. These simulations have shown that solar systems of many planets could in principle be stable over billions of years[1], but it's not known for certain this is the case with our own solar system from this point forward. Someguy1221 (talk) 03:00, 24 April 2018 (UTC)

If the Solar System wasn't fairly stable, we probably wouldn't be here to observe it. Moreover, what we see now is the result of over 4 billion years of evolution. The early Solar System was quite chaotic. All the terrestrial planets are probably the results of dozens of planetesimals crashing into each other. It's increasingly thought that the outer planets migrated after their formation, in the process turning the whole Solar System into a shooting gallery. Anything that didn't collide with something else or get swept into a stable orbit was ejected. This may have included an entire extra ice giant (and we may have possibly found it, though this isn't confirmed). Even since then, comets periodically have been perturbed by galactic tides and passing stars, either yanking them away from the Solar System entirely or causing them to fall towards the Sun, which is why they show up here. Also, Triton and Mars's moons are in unstable orbits, and will eventually collide with their primaries, get ripped apart into ring systems, or fly off. It's just that these things take a long time relative to our puny human timescales. --47.146.63.87 (talk) 07:18, 24 April 2018 (UTC)

• The other thing to consider is that the systems are only metastable, meaning that on timescales open for active observation, they aren't varying much. When you expand your perspective from using days or years as your base unit to billions of years as your base unit, the system is highly unstable and stuff has been smashing and careening off in unpredictable directions quite a lot. It's all perspective. --Jayron32 12:24, 24 April 2018 (UTC)

The rule of eccentricity is that what goes up must come down ... caveat being, not all orbits intersect the ground. Throw a baseball in the air and its orbit will be highly eccentric; given the chance it would pass within perhaps a few kilometers of the Earth's core at great speed. For a classic Keplerian orbit to happen all the Earth's mass would have to be at its center, and we'd neglect any relativistic frame dragging etc., in which case the ball would return in due course to the pitcher's hand. But, the pesky ground is in the way. Throw the same baseball from a very high tower (that extends far above the atmosphere), with a very good pitcher (like kilometers per second good), and it might pass so far from the Earth's center that it never hits the ground at all. Then it simply goes down, and up again. At the highest point it is moving too slow to avoid falling, and at the low point it is moving too fast to stay in a stable loop around the planet. Wnt (talk) 12:36, 24 April 2018 (UTC)

Food poisoning

In the most recent news, romaine lettuce is tainted by Escherichia coli in one farm in which the romaine is grown. Somehow, the illnesses are tracked/logged throughout the entire country, and everyone is staying away from romaine lettuce. Some people seem to have a full recovery after a week. Others take several weeks of hospitalization because of kidney failure and diagnosis of HUS. No one has died, though. It just has made the infected people miserable. First of all, I'm curious how the plant is handled at home. I think romaine lettuce is usually eaten raw. Running tap water to wash the heads may not be enough, or maybe the tap water is contaminated. Second of all, what food-borne pathogens are resistant to heat, and how much heat is needed to theoretically kill the pathogen? Third, and this question may be a little off-topic, is eating unwashed fresh produce or raw meats a good way for a person who wants to commit suicide? Or will the pathogens just make the person miserable or make the person lose so much water that he/she dies of dehydration instead? SSS (talk) 23:30, 23 April 2018 (UTC)

Also interesting to know is whether the use of PPIs plays a role here. Count Iblis (talk) 01:59, 24 April 2018 (UTC)

The FDA and USDA make manufacturers and growers put lot numbers on their products so that they can be traced. The system is weak for produce, as evidenced by the fact that the source romaine lettuce for this latest outbreak has not been pinpointed. The typical raw produce outbreak starts with either improperly composted manure, or overworked farm workers forced to defecate in the fields by the landowners. No food-borne pathogen is resistant to heat, but some are better able to survive a given temperature. Bacillus cereus spores can survive boiling for as long as it takes to cook rice, if you are looking for a dangerous example. Abductive (reasoning) 05:12, 24 April 2018 (UTC)

I am reminded of this video. As a cultural note, this behavior of not drinking tap water is not only shared by Chinese people in China, but also overseas Chinese people who recently settled abroad. Foreigners from wealthy countries with safe water pipes and well-treated water come to China to find that they can't drink the tap water. Also, it is not really a cultural practice to eat salads; even the word salad in Chinese is a loanword. Cooking the water and the vegetables may kill the pathogens. SSS (talk) 10:54, 24 April 2018 (UTC)

Today, eating in China is a health hazard. Count Iblis (talk) 04:33, 25 April 2018 (UTC)

In any case, the lack of salad consumption doesn't mean raw vegetables aren't consumed. For example, while not something common in China, Popiah is ethnic Chinese cuisine and AFAIK raw lettuce (not normally romaine) can be a part. (Although the mung beans are I think normally blanched.) Likewise AFAIK raw lettuce is a not uncommon ingredient in fresh Vietnamese spring rolls (often called summer rolls.) And there are so many varieties of spring rolls in China including plenty of fresh ones I would be surprised if there aren't some where raw lettuce is common ingredient. Lettuce can also be used for presentation especially for professional prepared meals (e.g. our article includes one from HK) and these may not be cooked in any way. The lettuce itself may or may not be eaten but in any case, there's no guarantee the food itself will be hot enough to prevent the pickup of contaminants. To put it a different way China produces about half of the worlds lettuce per Lettuce production in China and lettuce, and most of this is for domestic consumption. Our article is unclear whether this figure is including stem lettuce, but it's still a lot. While a fair amount of this may be cooked, it's unlikely all of it is, well even if we put aside modern usages and only consider traditional ones (and a lot of traditions are more recent than people tend to appreciate). Or to put it a different way, China is such a big and diverse place it's a little silly to talk in absolutes. In other words, raw lettuce in China may be a lot less common than in some other places, but it doesn't mean it's unheard of. In any case, whatever the traditions, things are changing [2]. Nil Einne (talk) 10:45, 27 April 2018 (UTC)

• Regarding Romaine lettuce, its primary (probably only significant) use is in the U.S. in salads or as a garnish in sandwiches, it is (WP:OBPERSONAL warning) probably the second most common salad green after iceberg lettuce; it's most famous use is in Caesar salad, but it's a common enough green for use in many salads. --Jayron32 12:17, 24 April 2018 (UTC)

How the plant is handedld at home: First the housewife normaly removes the tougher outer leaves to expose the more tender, sweeter head. This faily good at removing most of the Escherichia coli that is ubiquduse and existes everywere in dilute quantise too small to cause infection. See: Infectious dose. Problem arises usually with prepared salads. The whole head, Escherichia coli and all go into the washing tanks and the lot gets contaminated, then copped up and put into little convent-to -use-bags of salad – were it continues to multiply. Note: that the authorities are tying to track down the source but not the cause. The cause has been understood for many decades. It is from the use of sewage sludge as a fertilizer which by its nature has very high concentrations of Escherichia coli. When it rains heavily, the drops cause heavily contaminated soil particles to splash up onto the outer leaves. So it is important to wash them... in clean fresh water and not recycled water as used in food processing factories. One may be able to get away with rewashing prepared salad in vinegar/table salt/sugar solution [3] but the extra time and effort involved make traditional home preparation easier, quicker and cheaper than prepared salad. Also, prepared salad bags are fill with a gas so the the cut (wounded) vegetables don't visibly degrade whilst on the supermarket shelf. Once opened the gas leave and by the next day and the rest of the unused bag has to be thrown away as it is going rotten. Were as fresh heads last longer. So, prepared is false economy as well as a potential danger to health. Think about the statics, over ones life time most people get food poisoning at least once so why invite it in? Still, to end on a positive note. One can only die from food poisoning once. Aspro (talk) 15:14, 24 April 2018 (UTC)

Food poisoning in produce is complicated because of how quickly things like lettuce take up water. Let's say you have a head of lettuce that's perfectly fine. It's picked and dirty water is splashed on it inadvertently. Washing would likely remove enough of that bacterial load to make it safe to eat raw afterwards, though there would always be the risk that enough germs "held on" to make the eater sick. However, if the lettuce is still in the ground and dirty water is splashed on it - say, from the pickers relieving themselves in the fields - the bacteria would get into the soil and thence into the very fibre of the plant. No amount of washing will have an impact there because the germs are inside the cells of the lettuce. In that sense, it's similar to infected chicken - rinsing the chicken would not make it safe to eat raw. Lettuce is particularly susceptible to these kinds of contamination because it's essentially only ever eaten raw; if it was contaminated when you brought it home, there's nothing you can do to render it safer to eat. Regarding safe temperatures to kill germs, see Danger Zone. Matt Deres (talk) 17:03, 24 April 2018 (UTC)

Matt Deres, if bacteria can get inside the cells of lettuce and other food eaten raw, then shouldn't we boil our lettuce and fresh fruit before eating it? Dbfirs 17:12, 24 April 2018 (UTC)

Ditto. Don't think your right about Escherichia coli existing inside a plant cell. Wrong environment.Aspro (talk) 17:30, 24 April 2018 (UTC)

According to this, they cannot. Per my source below, and per that source, they can be taken up into the roots of plants, though this seems to be as part of the vessels carrying the water, and I see no evidence that the bacteria can cross the cell membrane and be taken up inside of cells. It'd be like fitting a volkswagen through a peephole. It may be smaller than the inside of the cell, but the I don't know how such a thing would cross a membrane. What I think is unimportant, however, since we have two sources (that one and below) which clearly state "However, after looking at whether any of the E. coli strains traveled past the roots and up into the plant’s interior structures, the researchers concluded that that sort of internalization appeared to be unlikely. “We wanted to investigate this, because it was one of the questions out there,” USDA microbiologist Manan Sharma told Food Safety News in an earlier interview. “We’ve taken something that has been of concern for eight or nine years and put it to rest.” (quote from source at start of this comment). --Jayron32 17:48, 24 April 2018 (UTC)

And just to quantify my flippant "fitting a volkswagen through a peephole" comment, e. coli are about 1000 times the diameter of the largest pores in a cell membrane. See Escherichia coli which notes that the size is on the order of 1-2 micrometers (10^-6 meters) while pores in cell membranes seem to have a maximum diameter of about 1-2 nanometers (10^-9 meters). See here. A volkswagen is 2-3 meters wide, and a peephole is 2-3 millimeters wide. --Jayron32 17:56, 24 April 2018 (UTC)

I stand corrected. Thank you! I picked that up somewhere that seemed reliable and have been repeating it for years. Matt Deres (talk) 01:50, 25 April 2018 (UTC)

As an interesting aside, I came across [4] which is an experiment using plant xylem from coniferous trees for water filtration for human consumption. However the source mentions xylem from gymnosperms are much more suited from this than angiosperms although the only real reason relevant to this question is the longer vessel length and my vague memory suggests to me a single vessel from the roots to the leaf stalks is unlikely. Nil Einne (talk) 07:50, 25 April 2018 (UTC)

• This article is an interesting read, and directly relevent to the subject. --Jayron32 17:17, 24 April 2018 (UTC)

Thank you for that link which reassures me that I can continue to eat lettuce and fruit uncooked if it is well washed. The article states that the bacteria exist in the rhizosphere, that is, in the "region of the soil in the vicinity of plant roots, considered as a microenvironment in which the chemistry and microbiology is influenced by root growth, respiration, and nutrient exchange" (OED). Dbfirs 17:49, 24 April 2018 (UTC)

If human or animal poop containing a particularly bad strain of E coli was on the hand of one worker who picked one day a limited number of heads of Romaine would be contaminated and a few families would be affected. It seems more likely that the processing involves washing the product with water which becomes contaminated or that a farm has an irrigation process which contaminates their lettuce. Is a sensor commercially available, such as an analysis chip which could monitor in real time the water used to wash a farm product such as the Romaine, sounding a warning to stop the production line when significant contamination is detected? Then perhaps the lots of produce from various suppliers could be tested to find the bad guy. As is, the detection method is waiting for consumers to be very ill, then trying to analyse what they ate, just like they did about the year 1900. Is real time detection of deadly pathogens in the foodstream possible today? Edison (talk) 04:53, 25 April 2018 (UTC)