Wikipedia:Reference desk/Archives/Science/2020 November 18

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November 18

How food protein passes into breast milk

Multiple studies (example) have shown that proteins from food mothers eat is present in breast milk, albeit in small quantities. Such proteins can cause sensitivity or allergic reactions in infants. However, my current understanding is that absent uncommon stomach lining or intestinal issues like ulcers, full proteins should not be able to pass from the digestive system into the blood. Proteins must first be broken down into their constituent amino acids before being absorbed into the blood. So, then, how could full proteins from food be present in breast milk shortly after consumption? Mamyles (talk) 02:24, 18 November 2020 (UTC)

The issue is discussed in: Peter J. Kilshaw, Andrew J. Cant (1984). "The Passage of Maternal Dietary Proteins into Human Breast Milk". International Archives of Allergy and Immunology 75(1), 8–15.^[1] They observe that, while "[u]n-ionized lipid-soluble drugs pass readily from the blood to the milk [...], there is less direct evidence for the transfer of food proteins from the gut to breast milk". In the end, they write, "The detection of foreign food proteins in breast milk presents an enigma." The article has been cited many times, almost exclusively in connection with food protein-induced enterocolitis. I saw no attempts to resolve the enigma.  --Lambiam 11:04, 18 November 2020 (UTC)

I'd be curious to see some sort of isotopic tagging done to make sure that's even what is occurring at all (i.e. food protein passing to breast milk). Tagging all of the nitrogens in a protein with N15, for example, and then testing the resulting protein in breast milk. If it remains near 100% N15 for a protein of interest, that is more clear evidence that it passed directly to breast milk. If the percentage has dropped considerably, that would suggest that the protein was broken down, and then the same protein was re-assembled de novo, at least to some extent. If that were the case, it becomes no longer a question of how food protein is ending up in breast milk, but one of de novo protein synthesis and, possibly, what causes it to occur (I don't feel like getting into a complicated discussion of transcription factors or epigenetics here, but you get the idea). --OuroborosCobra (talk) 21:41, 18 November 2020 (UTC)

Perhaps it does not get there through the blood but via hands. Or maybe the proteins are not full, but partly broken down. Graeme Bartlett (talk) 10:03, 25 November 2020 (UTC)

Has there been studies of peanut like immune therapy for arthritis?

I know a lot of drugs for arthritis are classed as immunotheraphy drugs and essentially suppress parts of the immune system. I was wondering if there had been any studies of doing the same sort of thing as is sometimes done for things like a peanut allergy - to gradually introduce larger bits of peanut till the body is accustomzed to it. In the case of arthritis it woud be to introduce larger amounts of whatever the arthritis is specifically reacting to and attacking. Thanks. 86.20.127.101 (talk) 12:44, 18 November 2020 (UTC)

The fundamental difference here is that peanut allergies are allergies to a foreign substance; something which isn't in the body already. Immune-system caused arthritis, like Rheumatoid arthritis, are autoimmune disorders, which means that it is the body's own tissues and cells and molecules which the immune system is attacking. The "allergen" in this case is already in the body. --Jayron32 13:40, 18 November 2020 (UTC)

True - but what difference does that make? 86.20.127.101 (talk) 13:58, 18 November 2020 (UTC)

The idea behind the building up a tolerance to a peanut allergy is to introduce peanuts to the patient to slowly acclimatize the body to the foreign substance. There is no foreign substance in an autoimmune disorder. The body is having an immune response to something already in the body. There's nothing to introduce. --Jayron32 14:19, 18 November 2020 (UTC)

Peanuts are not foreign when there is a reaction. The body has encountered peanut before. And they are able to reduce the reaction by introducing more peanuts. What I'd like to know is whether there has been a study of trying the same sort of thing with arthritis. Whatever it is that the body is reacting to could the reaction be damped by eating a higher dose? It sounds to me like an obvious thing to try out and if so the results were very likely be negative as it would be a cheap thing to do, but then again there's lots of things which are obvious only after the fact. 86.20.127.101 (talk) 14:41, 18 November 2020 (UTC)

You have peanuts inside your body? How did they grow there? What a strange thing. Can you show me in an anatomy textbook where peanuts happen in the body? Which organ system are they part of? Where are the genetic instructions in our gene code to grow peanuts? --Jayron32 17:53, 18 November 2020 (UTC)

It is very interesting that there is so little mention of flare ups in the articles you pointed at. Following from the peanut allergy treatment ss far as I can see flare ups are probable a suppression system of the immune system failing rather than the immune system doing more work. Otherwise we have no good explanation of why it doesn't just get worse with time insted of having remissions and flare ups. But who am I to know? It is surprising there seems so little questioning of the mechanism of remission ad flare up when it is such a terrible worldwide disease. 86.20.127.101 (talk) 16:21, 18 November 2020 (UTC)

You may be interested in looking at research for multiple sclerosis, which involves a similar immune system response. I know there has been significant research into what causes MS remissions/flareups and why the condition can degrade into a progressive disease. Mamyles (talk) 18:18, 18 November 2020 (UTC)

Thanks for that. You're right it is very similar in having remissions and flareups and having no known cure but various things that help. Looking around I've only seen statements like flare ups could be triggered by factors like stress or infections. Like arthritis I didn't see anything that went to a deeper level than that though unfortunately. 86.20.127.101 (talk) 21:46, 18 November 2020 (UTC)

You have to take into account that "the immune system" is not a single thing. It's a very complicated collection of responses. One of these responses, mediated by an antibody type called IgE, is responsible for allergies. Allergen immunotherapy is believed to work, not so much by preventing the body from responding to the allergen, as by shifting the response to different pathways, such as cellular immunity or perhaps IgG.

That's type I hypersensitivity. Per our articles, rheumatoid arthritis seems to be instead type III hypersensitivity, which is a completely different mechanism, and our article on it makes no mention of IgE.

So there's no obvious reason to think that this sort of treatment would work. That said, your question was whether it has been studied, and that I do not know. --Trovatore (talk) 18:19, 18 November 2020 (UTC)

Thank you, that looks very helpful. I'll have a good read of that. There's obviously some feedback mechanism causing remissions so I'll have a look for that. 86.20.127.101 (talk)

Using some keywords from those topics I put "treatment of autoimmune diseases with sublinual immunotheraphy" into google and as far as I can see there have been encouraging results but seemingly the alergens and doses tend to be specific. Antigen-specific immunotherapy of autoimmune and allergic diseases from 10 years ago is a summary of the state at the time and the references to it give more recent studies. There seems to be some mechanism for telling whether an extra dose of an allergen should be treated as something to acclimtize to or treated as dangerous depending or whether there is an infection at the same time - it is all horribly complicated but it's good to see it is being investigated. 86.20.127.101 (talk) 15:04, 21 November 2020 (UTC)

Data collection in time-sensitive circumstances

The OP, especially the title, might ask an interesting question along the line of "how to take a decision when acting early is better but waiting gives information about which actions to take". Sadly, the other half of the question was targeted towards a political hot-topic, and every answer dived on that. Might as well close the can of worms now; the non-political part could probably be rescued by asking something at WP:RD/C about online problems. TigraanClick here to contact me 10:28, 20 November 2020 (UTC)

In some areas, particularly analysis of the effects of global warming, critics sometimes argue that because of short periods of analyzed data (say, 10-15 years which is deemed too short for climatological purposes), more time should pass to ascertain reliability of a given conclusion. On the other hand, and rightfully so, it could be argued that waiting longer is simply dangerous due to increasing global warming and its effects. With that in mind and because some climate trends are recent, is there a need for reliable climatological conclusions based on data collected in relatively short time? Brandmeistertalk 18:04, 18 November 2020 (UTC) There's two things 1) global warming per se is not the only environmental problem from fossil fuel consumption, there are numerous issues like acid rain and smog and land and water pollution due to extraction, and LOTS of other concerns in that regard. Even if we were wrong on the global warming thing (and we're definitely NOT wrong, as near as all evidence points, but let's just concede that point for the rest of this discussion), the other effects of fossil fuel usage is more than bad enough that ending our use of them is more than justified. 2) We don't have only 10-15 years of data. We have centuries of data on the matter, and that's part of why the conclusions are fairly widely accepted. --Jayron32 18:09, 18 November 2020 (UTC) Jayron, forgive me for nitpicking, but your rhetorical method is not correctly called a "concession" unless you accept that the opponent's position is actually correct - and you have not accepted it. What you have done here is not to concede – but rather to suspend – your claim. Contrast with synchoresis, a strategic method of argumentation in which you actually concede that one of your opponent's sub-claims is true so that you may move the discussion onward to refute their overall argument on other grounds. Because you do not admit that the hypothetical opponent has refuted global warming - you have ignored their claim and not accepted it. Your method isn't a fallacy: it's a valid strategy, and it is not named "concession." I realize that this is a nitpick, but ... let's not allow a simple error in diction to dilute the importance of true and sincere concession, which has an important role in civil society. Nimur (talk) 00:44, 19 November 2020 (UTC) I do realize this is not a 15-year database. By 10-15 years I mean some recent climate trend within that time span (like increased rainfalls, increased fogs, frequency of hurricanes, etc) that needs to be analyzed to ascertain whether it's a simple weather pattern or a potentially dangerous recent trend of climate change. Seemingly from that arises the need for reliable interpretations within constrained timeframes. Brandmeistertalk 18:21, 18 November 2020 (UTC) Climate-change response is multifaceted, and not constrained to a single set of responses. For example, in the short term, the response is mostly based on mitigation and resiliency, how do we make our cities and structures and systems and the like more able to handle more storms, more rainfall (in some places) more drought (in other places), higher sea levels, etc. We know that those things are happening, so we are looking for ways to mitigate the effects of them. We're also looking for ways in the longer term to reverse the effects of climate change by reducing the primary causes of it. So the 10-15 year "short term" stuff you are talking about is mostly concerned with mitigation of effects: we know that, in the past several years, we've had these set of problems (flooding, storm damage, etc.); what do we do so these events aren't as harmful? How do I make my coastal cities survive a hurricane better? That sort of thing. The sort of stuff that is based on reducing the problems (i.e. influencing the climate so there are less storms, etc.) are based on the longer-term data we have going back centuries that shows a correlative and causative effect between increased levels of various greenhouse gases and increased temperatures. --Jayron32 18:35, 18 November 2020 (UTC) If we are talking about science and mathematics, not politics, then the relationship between the length of a time history of a signal, and the information that can be extracted from it, is well understood. In the case of a noisy signal like global average annual temperature (a fairly stupid one) it is very hard to discern the relatively small linearly increasing (approximately) effect of CO2 amongst the other more powerful ones, over mere decades. "and rightfully so" editorialising much? Greglocock (talk) 21:47, 18 November 2020 (UTC) If I may participate in a bit of ... synchoresis - it is true that we can use mathematical formalism to relate the time-history of a signal to the amount of information that can be extracted from the signal. However, the relation between any particular global average temperature metric and carbon-dioxide has been formally studied by experts, who have specialized training in mathematical signal analysis; so when they make their claims and a consensus is formed among the experts after careful review by peers, we should not assume that naive errors of arithmetic have somehow persisted. The conclusions published by many different well-respected groups of experts all generally align in the same manner: there is a causal relationship between human activity (and in specific, in human-generated carbon dioxide emission) and the temperature change that we observe. As Greglocock correctly stated, it is very hard to discern that relationship (synchoresis!) – but by way of detailed work that has been scrutinized and checked and verified by multiple groups of independent experts, that hard work was completed. There are many ways to quantify this causal relationship, and this is not the right place for us to delve into the details; but if you're interested, here is literally actually factually the top front and center citation on the IPCC's website: Methodology Report on Short-Lived Climate Forcers, a detailed study that ...reports... on the methodology... for estimating the climate effects from short-term signals (specifically, the details pertain to certain pollutants and the atmospheric chemistry that governs their behaviors). That is just one of many thousands of reports on methodologies that individually build toward the greater conclusions summarized in the executive brief from the last report. I mean, I'm really trying not to make this a fallacious appeal to authority, but do you really think that your interpretation is more correct than the detailed, published peer-reviewed interpretations by the teams of experts who are tasked with specifically addressing your concern? If you are equally-qualified to interpret the mathematical or scientific methodology, as those teams of experts are, then... where is the reliable reference to your peer-reviewed published dissenting opinion? Nimur (talk) 00:44, 19 November 2020 (UTC) With respect that sounds more like strawman than anything else. I'm explicitly not saying the co2 effect isn't there, but it is hard to see in the short term. And in context, even thirty years is short term, and it has only been discernible since 1950 according to IPCC. main issue is MDO, in that sort of timeframe, which has an amplitude of about 0.6 deg c pk-pk in 35 years, roughly double what the co2 signal is. Greglocock (talk) 06:56, 20 November 2020 (UTC) I think one of the main issues with people having trouble believing the results is that they equate "hard for me to do" with "hard to do", as though merely because they themselves lack the training, native ability, or skills to perform some task, that the task is impossible and people who have done it are just making it up. --Jayron32 13:45, 19 November 2020 (UTC) The burden of proof is on the conspiracy theorist to make an advanced supercomputer model that shows paradoxical non-warming. Until then the 19th century sunny glass containers of CO2 and air experiment should be all the Occam's Razor any nutty non-climatologist conspiracy theorist needs to see which is more likely: a) all the supercomputer models or b) a Marxist secret world-government conspiracy by the godless Popes or Masons or Muslims or Jews or LGBT who rule Earth to fake climate data to RULE THE WORLD! MWAHHAHAHAHA! Step 1: Collect underpants Creeping carbon tax till renewable's cheaper Step 2: ?? Step 3: Communism! Sagittarian Milky Way (talk) 22:55, 18 November 2020 (UTC) As usual SMW entirely irrelevant. We are discussing signal processing, not your political beliefs. Greglocock (talk) 19:41, 19 November 2020 (UTC) Whether a conspiracy of thousands of the planet's experts on the topic to fake the peer-reviewed consensus is plausible is a scientific question not a political belief. Do you have a reason why they'd all do that? That lots of deniers think the motivation is communists or whoever are trying to takeover the world is the political belief, right up there with moon truthers and anti-vaxxers in plausibility. Sagittarian Milky Way (talk) 23:04, 19 November 2020 (UTC) I might add that whether the 40+ (NOT 10) years of satellite Arctic sea ice or 53+ years of geostationary weather monitoring is long enough is irrelevant if the world's foremost experts on the topic have already concluded that the science is settled and they're just b shrinking the error bars. Not only that but even if by some amazingly underpredicted negative feedback the temperature stops rising soon then so what if renewable energy is incubated by environmental law till it can outcompete carbon on the free market, fossil fuel is going to have to get more expensive someday, might as well do it before it gets scarce and the air is fucked up and it'll make other tech like batteries that don't suck come sooner. The downsides of the practically 100% sure warming are far worse than the decarbonization cost so it is irrational to wait to see more warming before starting the decades-long process. In fact there is no realistic decarbonization speed that's too fast, the benefits of going slightly faster always outweigh the drawbacks of the slightly faster for all realistic decarbonization speeds that might actually happen. i.e. 3 years for instance is too fast and disruptive, will never happen but 3 decades is realistic. Sagittarian Milky Way (talk) 01:27, 20 November 2020 (UTC)

Which volcanoes support ore genesis and which ones do not

So, from even a cursory overview of sources it appears like volcanic arc volcanoes often have ore deposits associated with them e.g Choquelimpie. However, I can't find anything about marine mantle plume volcanoes such as Iceland and Hawaii. Why do these not have ore deposits? JoJo Eumerus mobile (main talk) 21:30, 18 November 2020 (UTC)

A possible explanation is that minerals with a high specific gravity (compared to the average value of the magma) migrate down in the magma, leaving insufficiently little in the mantle to make mining mantle-plume deposits economically rewarding.  --Lambiam 12:07, 19 November 2020 (UTC)

Another idea is that there may be varying amounts of water in different kinds of lava that then can inject supercritical water into surrounding rocks, and that could migrate minerals. Also magma from subducted crust may be more variable than deeper mantle melts. Graeme Bartlett (talk) 10:01, 25 November 2020 (UTC)