Wikipedia:Reference desk/Archives/Science/2020 March 25

= March 25 =

Was Toxic Oil Syndrome really caused by cooking oil?
Hi Wikipedia, I've been looking into the topic of Toxic oil syndrome and when I went into the Spanish Wikipedia article, it had a rather lengthy section on conspiracy theories, namely one claiming that it hadn't been caused by cooking oil, but a tomato pesticide instead. Checking the three sources cited, they all seemed to be from conspiracy blogs that didn't seem very trustworthy, so I decided to be bold and delete the section. However, I recently began looking at online resources in English and I found this article. In fact, it is mentioned in a similar section in the English article. This source made almost all of the claims that the Spanish article made, and it seems to be a reliable source, unlike the blogs cited in the Spanish article. A talk page discussion was opened on it long ago but it didn't lead anywhere. I'm a bit conflicted. Of course, I'm not very keen on believing conspiracies, but this does seem to have a reliable source. Meanwhile, the official version still is that the oil was at fault. Can anyone more familiar with this topic shed a bit of light? GoodCrossing (talk) 00:20, 25 March 2020 (UTC)
 * I remember that time, and the cause was then stated to be a charge of cheap edible oil mixed with gun oil, specifically oil for machine guns. Gun oils do often contain additives such as Polytetrafluorethylene (PTFE) or Molybdenum, which are directly or indirectly toxic and/or neurotoxic. But if you have a source we can mention this alternative organo-phosphates theory without necessarily backing it 89.204.130.58 (talk) 14:32, 25 March 2020 (UTC) Marco PB
 * I am familiar with the event as I'm from Spain. However, the only reliable source I can find is that Guardian article, and it seems to be largely based on the original work of Dr. Muro, who seems to lead the conspiracy theory. I haven't found any other scientific consensus on if Muro's theories are correct or not. GoodCrossing (talk) 15:45, 25 March 2020 (UTC)
 * Two brief contemporaneous articles from the New Scientist about the ongoing trial:, . The theory of pesticide poisoning came first; the theory of an organized cover-up came only later, but our article strongly suggests they are one and the same thing. Our article also does not cover the trial; I think it should. --Lambiam 21:04, 25 March 2020 (UTC)
 * Here is an earlier New Scientist article on the debate about the cause. It mentions the alternative theory that toxic organophosphates were the culprit without hinting at a conspiracy. --Lambiam 21:15, 25 March 2020 (UTC)

Likelihood of recovery from a serious case of COVID-19 with medical assistance
In general, what is the likelihood that a person who develops a serious (potentially life-threatening) case of COVID-19 will recover if they receive medical attention? Freeknowledgecreator (talk) 01:49, 25 March 2020 (UTC)


 * In the initial stages, all cases are potentially life-threatening. For any meaningful statistics, one needs an operational objective definition of "serious" that is applied across the board. Did the patient already receive the best medical care, given the state of medical knowledge and technology as soon as they became symptomatic, or did treatment only commence after the disease progressed to a serious condition? And what constitutes recovery? Not dying is not the same as recovering. Little is known yet about long-term damage. So the mortality risk, even if known, will not tell us the answer. It may be possible to dredge up some figure from the slush of data, but in this stage I wouldn’t attach much meaning to it. --Lambiam 03:46, 25 March 2020 (UTC)
 * You understand what I'm asking. What are the chances that medical science can save someone who looks likely to die of COVID-19 if they don't get help? Freeknowledgecreator (talk) 04:45, 25 March 2020 (UTC)
 * No, we do not understand what you are asking, at least not in a way that can be answered meaningfully. You are asking for a quantitative answer (probability) to a qualitative measure (what constitutes "serious"?). As with your many other posts, there is no way that we can answer this question in a way you would find acceptable. We can ask you to be more specific, but then you respond like this, with indignation. Enough, drop the attitude, and cooperate with us when we respond, including when we respond by saying "we need to know more from you and a more specific question in order to answer you." Among other things we need to know, in addition to what constitutes "serious," is whether your question regards a healthy 30 year old female, or a chemotherapy male patient aged 75. The answer will be different. There is no "average" we can give you since the answers vary so wildly, and different populations have different portions of at risk members. Italy, for example, is having a higher mortality rate in part due to an older aged population than the United States. Any answer we give you would be very different for the average Italian than the average American. In short, you are not asking a simple, easy to answer question. It isn't a matter of understanding what you are asking, it is that you are asking a question that, as stated the way you have, cannot be simply answered. --OuroborosCobra (talk) 15:42, 25 March 2020 (UTC)
 * Your response is much more indignant than mine. I'm not asking for a precise answer to the question how likely it is that someone who looks likely to die of COVID-19 can be saved by medical science; an answer in general terms is fine. Qualify that answer for different kinds of patients as much as you wish. Freeknowledgecreator (talk) 22:50, 25 March 2020 (UTC)
 * This isn't your first rodeo. Don't think you will be treated as such. If you aren't asking for a "precise" answer, then what type of answer are you even asking for? Seriously, I have no idea what you are asking anymore at all. Since we do not know what you are asking, you can dismiss any answer we give you as unacceptable. Restate your question in a way that anyone can possibly answer. What does "general terms" mean? I have absolutely no idea. You don't seem to want a numerical answer, so what answer DO you want? We cannot answer your question, because it isn't even an actual question. --OuroborosCobra (talk) 15:06, 26 March 2020 (UTC)
 * It is better not to comment than to make rude or hostile comments, such as the above. I would have thought that the meaning of the expression "general terms" did not require explanation. I am simply asking whether most people who look likely to die of COVID-19 can be saved by medical assistance. The question is perfectly clear. It remains clear regardless of the fact that different kinds of patients may be more or less likely to die. Freeknowledgecreator (talk) 23:47, 26 March 2020 (UTC)
 * In "general terms", this thing is quite new, and we don't have enough information to answer the question. ←Baseball Bugs What's up, Doc? carrots→ 23:49, 26 March 2020 (UTC)
 * Thank you. A "no one can answer the question because there isn't enough information available" response is perfectly appropriate. Certainly better than rude outbursts. Freeknowledgecreator (talk) 23:52, 26 March 2020 (UTC)
 * Which is why I ignored your question entirely, until someone said "we can't answer it because we don't know what 'serious' means," and you responded by indignantly saying "you understand what I am asking." No. We don't. We don't know what "serious" means. We don't know what "general terms" means. I explained to you why, but I ignored your initial question as it was not answerable. I explained to you in plain terms what we needed from you in order to answer it, and you did not provide. --OuroborosCobra (talk) 19:42, 27 March 2020 (UTC)
 * If you felt that my initial question was unclear you could have politely asked me to clarify it instead of responding with rude outbursts such as the above. Freeknowledgecreator (talk) 01:35, 28 March 2020 (UTC)
 * That's what Lambiam did. You responded by saying "you understand what I am asking." If I had done what they did, you'd have responded the same way. The same way you did about coffee. Or blood. Or... --OuroborosCobra (talk) 23:15, 29 March 2020 (UTC)

Possible effects of many people self-isolating on Wkipedia editing etc
Greetings all in these 'interesting times'

I was wondering, what the potential effects of millions (billions?) of possibly very bored people having to stay away from, school, work etc on Wikipedia?

Will we have many new useful editors, or will we have so much vandalism or good-faith bad editing that we can't cope with it?

If this has already been covered, please direct me there. Regards, 220  of  Borg 04:14, 25 March 2020 (UTC)


 * , there's a related discussion at User_talk:Jimbo_Wales. I happen to be currently re-watching TNG ;-) Gråbergs Gråa Sång (talk) 08:03, 25 March 2020 (UTC)


 * Not streaming it, I hope! 😲 Thanks, I'll have a look at that thread. 👍 220  of  Borg 09:01, 25 March 2020 (UTC)


 * In the area of self-isolated pastimes, I was told that Pornhub offers a week free premium. Gråbergs Gråa Sång (talk) 09:05, 25 March 2020 (UTC)
 * I think it is more like a month, at least in Spain, Italy and France. . Well, getting back to topic, I think many more people will edit, and not in bad faith, and many older non-active editors may come back to stay for a while longer, I trust that this time will be benefitial for Wikipedia. Apolo234 (talk) 09:25, 26 March 2020 (UTC)

Blood & gender
If you take a blood sample from a random person, is it possible to tell whether the sample came from a male or female, purely from this sample? 92.9.144.104 (talk) 04:52, 25 March 2020 (UTC)
 * Yes. Looking for the presence vs absence of the Y chromosome is one way. 10.1016/0379-0738(86)90166-0 Analyzing blood and other fluid residues at a crime scene is a pretty important task in forensic science, which includes methods like serology and a boatload of other techniques. DMacks (talk)|
 * Convenience link: Y chromosome. Regarding the section title, note that today a sex-gender distinction is increasingly accepted. This is particularly notable in this context because an assumption based on karyotype will sometimes be wrong. Intersex people may have a phenotype that one would not typically associate with their genotype. People with complete androgen insensitivity syndrome have an XY genotype but a female phenotype. Some people have X0 (X-naught) or XXY genotypes, or an XY genotype but a dysfunctional SRY gene or other Y chromosome abnormalities and therefore not a typical male phenotype. --47.146.63.87 (talk) 06:01, 25 March 2020 (UTC)


 * If I'm reading Red blood cell correctly, red cells lack DNA. ←Baseball Bugs What's up, Doc? carrots→ 08:27, 25 March 2020 (UTC)
 * Red blood cells have a nucleus that contains DNA while they are within the bone marrow. When they move from the bone marrow to the circulation, that nucleus and the DNA contained within it are extracted and discarded, so that circulating RBCs ordinarily contain no nuclear DNA. However, there are occasional circulating RBC's where this process has failed. This results in circulating nucleated red blood cells (NRBCs). They are normal in neonatal blood, but should be very rare in circulating adult blood and their presence would prompt a search for a disease process that might be responsible for them. - Nunh-huh 01:42, 26 March 2020 (UTC)
 * Turns out we have a whole Nucleated red blood cell article:) DMacks (talk) 04:51, 26 March 2020 (UTC)
 * Yes, but blood also contains White blood cells, which do contain a nucleus with DNA.- gadfium 08:34, 25 March 2020 (UTC)
 * A useful microscopic finding would be the finding of Barr bodies within certain neutrophils on a peripheral smear, which would imply the blood was from a female. - Nunh-huh 01:42, 26 March 2020 (UTC)
 * Good point (and complementary positive test to presence of Y-chromosome). One could also look for various horomone levels (Prostate-specific antigen for males, multiple options for females). DMacks (talk) 04:51, 26 March 2020 (UTC)
 * And some people with a bone marrow transplant from a person of a different sex can show up with different sex to the rest of the body (chimera). Graeme Bartlett (talk) 09:59, 25 March 2020 (UTC)
 * So this Y chromosome, is found in white blood cells, and red blood cells within the bone marrow for the most part? 67.175.224.138 (talk) 04:42, 26 March 2020 (UTC).
 * The Y chromosome is found in every normal cell nucleus of a male human (and other mammals). Most human (etc.) cells have one nucleus; a few specialised cells have multiple nuclei; however red blood cells, aka Erythrocytes are unusual because they do not have nuclei, so do not contain any chromosomes. During the process by which red blood cells are formed in bone marrow, the developing cells which will become red blood cells expel their nuclei to become reticulocytes, which are released into the bloodstream and which mature into erythrocytes in a day or two (as compared to their overall lifetime of 3 to 4 months). {The poster formerly known as 87.81.230.195} 90.197.27.39 (talk) 11:33, 27 March 2020 (UTC)
 * Elaboration/nitpick: "normal cell" here means "nucleate somatic cell". Note that platelets, found in blood, are cell fragments rather than complete cells. --47.146.63.87 (talk) 19:41, 27 March 2020 (UTC)

Anadromous fish (salmon)
What is the motivation for the migration of anadromous fish like salmon? It seems to me awfully inefficient to have a fish live in the sea but also be able to adapt to fresh water just to go spawn somewhere and have a good chance of ending up in a bear's stomach along the way. What is the evolutionary advantage that helps the fish which perform this migration? The fish migration article wasn't of much help. 89.172.17.9 (talk) 12:15, 25 March 2020 (UTC)
 * One possibility is: living in the open sea many more adult salmons can find much more food than they would in some small mountain brook. On the other hand their hatchings are subject to much less predation in small mountain brooks than they were in the ocean. The most dangerous potential predators there being their own parents, and they die very conveniently just after having laid their eggs; also incidentally increasing the local disponibility of food. 89.204.130.58 (talk) 14:50, 25 March 2020 (UTC) Marco PB
 * Some support for this theory can be found in the article "The evolutionary origins of diadromy inferred from a time-calibrated phylogeny for Clupeiformes (herring and allies)". It mentions "evidence that temperate anadromous fishes are derived from freshwater ancestors that began migrating to oceans to exploit the higher productivity". But they conclude, "[o]ur results [for a different fish order than the salmons and allies. --L.] do not support the productivity hypothesis". Also, "the evolutionary origins of diadromy remain poorly understood". Evolution may take a warped path. Sharks started as sea fish, but some families became freshwater fish and so developed (like us mammals) a way to keep their blood as salty as sea water, rather than developing a physiology supported by "sweet blood", and then migrated out to the see again – and rather than reverting the previous adaptation, evolved desalination, so now the sea water first gets desalinated and then again salinated to become blood. Or so I have read somewhere. Next to the fitness advantage of diminished risk of predation for the young brood mentioned by Marco PB, it is conceivable evolution randomly followed the path of the spawners returning to freshwater for brood not adapted to sea water, instead of the alternative of the brood adapting to survive a salty environment. --Lambiam 20:05, 25 March 2020 (UTC)
 * Yes, evolution is path-dependent. It's a "blind watchmaker" that can only work with what it's got. Based on what you cited, salmon are descended from freshwater ancestors that started moving into more saline environments. But the juveniles retained the adaptation to freshwater, and so the adults have to return to that to spawn. This is similar to amphibians, where eggs and juveniles usually require an aquatic environment. As long as a trait is "good enough", it won't be driven out of a species by natural selection. The myriad examples of poor design in organisms are testament to that. --47.146.63.87 (talk) 21:52, 25 March 2020 (UTC)
 * Thanks for the answers! 89.172.8.37 (talk) 08:41, 29 March 2020 (UTC)

How is a virus in my eye a danger?
As a new SARS virus can be transferred on hands, health services advise people to avoid touching their mouth, nose and eyes. Why eyes? I understand how a virus, which attacks the mucous membrane of the respiratory system, can get there through mouth or nose. What I don't get, however, is: how can a virus move from eyes to a throat and further down to lungs? --CiaPan (talk) 17:45, 25 March 2020 (UTC)
 * Tear ducts perhaps? Bazza (talk) 18:28, 25 March 2020 (UTC)
 * Eyes are naturally wet. Assume that any part of the body which is naturally wet represents an entry point.
 * In this case, it's more specifically the tear ducts. The eye's natural dust flushing mechanism runs throughout the day (and at night, although often a little less). Tears (so small you don't notice) from the lacrimal glands flush the surface of the eye and are carried away (dust and virus too) down the nasolacrimal duct and into the sinuses (hollow spaces) of the nose. Obviously that then connects to the throat and trachea, and into the lungs. From there on its virus party time. Andy Dingley (talk) 18:29, 25 March 2020 (UTC)
 * Thank you, and .This makes the official advices pretty reasonable.  I just can't believe I never learned about it! Thanks again.  --CiaPan (talk) 19:44, 25 March 2020 (UTC)
 * This is why your nose runs when you cry. --47.146.63.87 (talk) 20:27, 25 March 2020 (UTC)
 * Yes, I know those happen together - but my nose usually runs when I do not cry (maybe because I almost never cry), so the causal relation is not that obvious;  running nose and tears might be independently caused by the same neural signal. Now when I know about the tear duct, the correlation is more obvious - but it did not seem so definite to me before to make me deduce the existence of the duct myself.   CiaPan (talk) 21:42, 25 March 2020 (UTC)
 * The proof is this unpleasant YouTube clip of a boy crying milk (don't try that at home folks). Alansplodge (talk) 12:30, 26 March 2020 (UTC)
 * Better to be known as the boy who cried milk than as the boy who cried wolf. --Lambiam 11:44, 28 March 2020 (UTC)