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March 5

coronavirus immunity

Do people infected with CV and recover from it become immune, like with some other viral illnesses? If this is not known, does it happen with regular flu? I'm wondering if antibodies from immune people can be used to treat infected people, as was apparently done with Ebola. Don't worry I'm not going to try this at home. Thanks. 2602:24A:DE47:B270:A096:24F4:F986:C62A (talk) 01:09, 5 March 2020 (UTC)[reply]

It seems to be too early to tell.[1] ←Baseball Bugs ^{What's up, Doc?} carrots→ 01:19, 5 March 2020 (UTC)[reply]

Thanks. I wonder how many post-recovery positive tests were people who weren't re-infected, but rather, never became non-infected (they beat back the virus enough to stop having symptoms, but not enough to get rid of it completely, like supposedly can happen if you don't take your full course of antibiotics for bacterial infections). To really detect re-infection we'd need to see a positive test followed by a negative test followed by a positive test, all in the same person. There also appear to be two strains of the virus going around now, so they'd have to distinguish them. 2602:24A:DE47:B270:A096:24F4:F986:C62A (talk) 01:45, 5 March 2020 (UTC)[reply]

https://www.dfa.co.za/international-news/japanese-woman-tests-positive-for-the-coronavirus-for-a-second-time-43594564 — Preceding unsigned comment added by 94.198.187.35 (talk) 10:33, 6 March 2020 (UTC)[reply]

A recent mutation of the virus may complicate things. Count Iblis (talk) 11:28, 6 March 2020 (UTC)[reply]

In general, the only way a body recovers from an infection is by obtaining an immunity to it. As opposed to, for example, poisons, which may or may not have varying tolerance levels. 73.222.115.101 (talk) 19:34, 7 March 2020 (UTC)[reply]

Wuhan coronavirus in New Zealand

To what extent is the Wuhan coronavirus a problem in New Zealand? Asking again as the situation is changing rapidly. Freeknowledgecreator (talk) 01:31, 5 March 2020 (UTC)[reply]

2020 coronavirus outbreak in New Zealand. 2602:24A:DE47:B270:A096:24F4:F986:C62A (talk) 01:43, 5 March 2020 (UTC)[reply]

Excavation methods

Are pneumatic caissons used as an alternative to the standard Piling, use of excavators and temporary retaining structures in large scale excavations? 126.255.11.145 (talk) 04:40, 5 March 2020 (UTC)[reply]

Have you seen Caisson (engineering)#Pneumatic? I saw some more detailed information here. If that does not answer your question, can you be more specific, in particular as to what engineering purpose the large scale excavation would serve? --Lambiam 08:05, 5 March 2020 (UTC)[reply]

Well, they're certainly used and would still be an alternative.

In the modern period, pneumatic caissons are used less than they used to be, in favour of larger open-topped caissons. The availability of powerful cranes means that a large caisson (i.e. large enough to reach the surface) is both more easily installed, and crane access from above is obviously useful. Health and safety aspects also discourage working under pressure. Also working with bulk materials in a pneumatic caisson was infamously difficult, as they mostly relied on manual effort to move and lift things and spoil removal / material supply was awkward through the lock.

If a pneumatic caisson was used to gain access to the bottom, that has largely been replaced. If a pneumatic caisson was used because access to the bottom still needed to be under pressure (i.e. water would flood in otherwise), those are still used.

Furthermore, open water diving has become more sophisticated. Tasks which might once have needed a caisson to work in are now being done underwater. Andy Dingley (talk) 15:07, 5 March 2020 (UTC)[reply]

March 6

jerk and jounce, or snap, crackle, and pop?

So the third derivative of position, if you need it, is jerk.
I just discovered we've got an article jounce on the fourth derivative.
But that's where things start getting a little hinky.
At jounce there's an image (citing a reference) suggesting that the fifth and sixth derivatives are called flounce and pounce.
But there's also an (attributed) quote saying "The not so common names for the next three derivatives are snap, crackle, and pop", and indeed we've actually got articles, citing multiple references, on crackle and pop.
I realize it's a pretty academic question, but does anyone know whether jounce/flounce/pounce, or snap/crackle/pop, are more "official", and deserving of having their names on articles here? I've chased the linked references about as far as I can, without finding much in the way of definitivity. —Steve Summit (talk) 19:21, 6 March 2020 (UTC)[reply]
P.S. And if this intrigues you, you can also look into absement, absity, abseleration, and abserk, or the somewhat related actergy.

While these are quite jovial terms, I don't think I've seen them seriously used in any physics or engineering context. It's much more appropriate, and a lot more common, to clearly describe the n^th derivative of position with respect to time.

As a point of note, when we use kinematic equations that actually do use the n^th derivative - for example, in complicated situations of mechanical control theory, robotics, vehicle dynamics, and so on... well,... when things are very simple, we only need to use second-order equations (hence, the omnipresent PID controller); and when we actually need more than two terms, then we're usually controlling a state-space matrix, or some other transform-domain; and so - if there were three or five or k-thousand terms, we are not typically controlling (or even caring about) the time-derivatives. Rather, we simply refer to the k-th element of the vector of control-variables, which may - for some special cases - be defined by some computable relationship to one or more time-derivatives. What we do have, in terms of standard terminologies, are specific names for specific methods to generate those computable relationships.

And therefore, every proper roboticist worth their salt has memorized every variant of those horrible A-B-C-D matrix methods, which are a formalization of the linearized relationships between all n-th order derivatives, and we can all solve them on paper, and do not actually have to resort to using MATLAB.

...So, we don't really need names for those higher-order derivatives of motion. As such, I tend to disbelieve anyone who claims to report an authoritative, widely-used nomenclature for them.

A great reference is the Nise book on Control Systems Engineering; that book is kind of the "canonical source of truth" for the "standard" terminology - at least among the community of engineers who design and study the dynamic control of mechanical systems. There are plenty of other great resources, too - I can dig some out if you want more...

Nimur (talk) 19:47, 6 March 2020 (UTC)[reply]

Oh, I get it about whether we need an "authoritative, widely-used nomenclature for them" -- and that's kind of why asked, since our articles Crackle (physics) and Pop (physics) could seem to lend the ol' "undue weight".

(Ironically, I am a roboticist, although evidently not one worth my salt. :-) )

—Steve Summit (talk) 03:27, 7 March 2020 (UTC)[reply]

A practical everyday example where jerk is important is holding onto a pole while standing aboard a bus or subway train. You can handle more acceleration if you know it's coming and have time to tighten your grip, and the way you know is that the jerk is low. --69.159.8.46 (talk) 03:30, 7 March 2020 (UTC)[reply]

Up to jounce is quite widely used. Above this I've only heard snap, crackle and pop.

High-order derivatives are used in cases where there's some other process acting as an integrator. Most commonly this is the human body: the organs flapping around inside can be sensed by their force on the abdominal wall and that can best be predicted by calculating these high derivatives for the vehicle the human is in. So the main application areas for this are rollercoaster physics (I think it was Disney who originally imagineered snap, crackle and pop), fighter aircraft pilot ergonomics and motor racing. F1 drivers experience small-dimension forces but of much higher acceleration (and jounce) far greater than fighter pilots do (More high-order impulse from concrete kerbs than aerodynamics).

Years ago, I made instrumented driving shoes with an accelerometer, to try and tie this to uncommanded throttle surges that were happening. Jounce was moving the ankle up and down and the high-precision throttle sensor was reacting so quickly that it was detecting these bounces. The fix was to low-pass filter the throttle control input. Andy Dingley (talk) 20:23, 6 March 2020 (UTC)[reply]

Btw, rollercoaster physics should redirect to Physics of roller coasters. —2606:A000:1126:28D:2D45:4564:93:B822 (talk) 23:13, 6 March 2020 (UTC) ... thx, User:scs

[reply]

And now it does. (You're welcome! :-) ) —Steve Summit (talk) 03:27, 7 March 2020 (UTC)[reply]

March 7

Eucharistic miracle at Sokółka

There is a claim of a Eucharistic miracle at Sokółka, Poland where upon close scientific examination, cardiac muscle fibres of a dying man were found intermixed with bread fibres in a way that no one can reproduce. Furthermore, there is another purported miracle I find somewhat compelling (which we do not have an article on), Our Lady of Las Lajas, Colombia. [2] Has the latter case been examined scientifically? Are there any skeptical scientists who have examined the first purported miracle? Why have neither of these claims been nominated for the Randi Prize? 2607:FEA8:1DDF:FEE1:C0AC:BED:E678:E3B (talk) 01:56, 7 March 2020 (UTC)[reply]

The Randi prize would require that this was reproducible, ie wafer turned into bread and heart mixture in a laboratory. I assume these were one off events with no careful checking beforehand. Graeme Bartlett (talk) 12:30, 7 March 2020 (UTC)[reply]

Also it's been discontinued according to the article. --47.146.63.87 (talk) 05:56, 8 March 2020 (UTC)[reply]

"X is not supernatural" is an unfalsifiable hypothesis. I'm idly curious as to how the scientists mentioned determined that the "interleaving" was "not reproducible". How would they tell if it was? Did they publish anything about this in a peer-reviewed journal? Also I'll note with a bit of amusement that the Catholic Church is usually very adamant that transubstantiation is not cannibalism, but there's no concern here. What if someone hadn't noticed and tried to consume it? (Assuming it's purportedly human tissue, which wasn't addressed, but I guess God turning something into a rat's heart wouldn't be as impressive.) Or I guess if God did it that means it's okay? --47.146.63.87 (talk) 05:56, 8 March 2020 (UTC)[reply]

I hope no human sacrifices are being conducted in the church of Saint Anthony in Sokółka, but from a forensic perspective I think the fact that the floor from which the Blessed Sacrament was picked up has not been immediately examined means that all bets are off. The article has been published as: "Eucharystyczne trwanie z perspektywy nauk ścisłych" [Eucharistic persistence from the perspective of the exact sciences]. Teologia i Człowiek (in Polish). 43 (3): 81–98. 2018. doi:10.12775/TiCz.2018.028. {{cite journal}}: Cite uses deprecated parameter |authors= (help) The full text is accessible on-line. --Lambiam 18:00, 8 March 2020 (UTC)[reply]

Sex differences in death rates for the Wuhan coronavirus

I've heard that men are more likely to die from the Wuhan coronavirus than women. Is it true that men are more likely to die of it than women, and if it is, what explains this? Freeknowledgecreator (talk) 05:47, 7 March 2020 (UTC)[reply]

Possibly due to more smoking. Graeme Bartlett (talk) 12:30, 7 March 2020 (UTC)[reply]

'On the question of why the virus is attacking men more than women, research has shown that, in China, many more men smoke than women. In fact, more than half of Chinese men smoke, compared with only around 3% of women. Smoking activates a receptor used by the coronavirus to infect human cells, ACE-2, Dr Greg Poland, a vaccine researcher and infectious disease specialist with the Mayo Clinic, in Rochester, Minnesota said, although this is speculative at this stage. However, Preiser weighed in and explained that if someone's lungs are affected by smoking (in a way, a chronic illness), then that certainly increases the risk from a virus that affects the lungs as “one has 'fewer reserves' to fall back on when the lungs are infected and inflamed”, he said.

Dheda adds: "Smokers are at higher risk of contracting many respiratory tract infections including influenza, TB, and Streptococcus pneumoniae, an important cause of acute pneumonia. There are a number of mechanisms by which cigarette smoking does this, including subverting the defensive functions of the airway lining and various types of immune defensive cells including macrophages and lymphocytes."' [3] Alansplodge (talk) 12:37, 7 March 2020 (UTC)[reply]

OK. So, if the difference is due to men smoking more, presumably there is no evidence that men are inherently more vulnerable to the disease? Freeknowledgecreator (talk) 00:32, 8 March 2020 (UTC)[reply]

It's too early to say for sure. As the disease spreads, more populations can be studied and the picture may become clearer. And, as always, "Absence of evidence is not evidence of absence." Matt Deres (talk) 02:09, 8 March 2020 (UTC)[reply]

If the difference is due to men smoking more, then the difference is probably simply due to smoking. Perhaps more attention to this factor needs to appear in sections about who is most likely to suffer serious consequences from this virus. HiLo48 (talk) 02:30, 8 March 2020 (UTC)[reply]

We need studies to say for sure. This is a hypothesis at present. --47.146.63.87 (talk) 06:10, 8 March 2020 (UTC)[reply]

That would be angiotensin converting enzyme 2. --47.146.63.87 (talk) 06:10, 8 March 2020 (UTC)[reply]

According to this article, there are differences between the immune systems of men and women that may partially explain the different death rates from the virus. So it's not necessarily just smoking. Freeknowledgecreator (talk) 09:10, 8 March 2020 (UTC)[reply]

Carbon monoxide questions.

How is CO excreted by the body? If it is at all. Carboxyhemoglobin eventually goes to the liver right, so isn't it eventually urinated out? As with red blood cells? 2ndly, what % of CO we breathe in is excreted out, because I heard someone say a % generally stays in your body for good. But that % is prolly just stuck in the liver, making it harmless? So maybe a % of it is released within years? And the rest urinated out? Thanks. 67.175.224.138 (talk) 14:32, 7 March 2020 (UTC).[reply]

It is my understanding that the CO remains tightly attached to the carboxyhemoglobin, even until the latter is removed from the blood by the kidneys. The main reason CO has such an adverse effect is that it cancels some haemoglobin, molecule for molecule, and that molecule of haemoglobin is never resuscitated. Dolphin (t) 03:40, 8 March 2020 (UTC)[reply]

No, CO isn't an irreversible inhibitor. See carboxyhemoglobin. The problem is that CO has a much greater affinity for hemoglobin than oxygen, so oxygen at ordinary concentrations doesn't displace CO quickly. --47.146.63.87 (talk) 06:28, 8 March 2020 (UTC)[reply]

So if CO unbinds to hemoglobin, it'll just rebind to another hemoglobin, and so and so forth, until it unbinds and there are no more hemoglobin binded to a CO or O2 left. Then it just continues down the blood vessel until? Until urinated out? 67.175.224.138 (talk) 04:03, 9 March 2020 (UTC).[reply]

"exhaled". When it's dissociated, it can diffuse back out in the alveoli (reversible transfer in/out at lungs. One basis for hyperbaric oxygen therapy is that the overwhelming amount of O2 being inhaled more rapidly exchanges for the O2 (doi: 10.1126/science.111.2894.652 is an early study on that). DMacks (talk) 05:26, 9 March 2020 (UTC)[reply]

Yes, carbon monoxide-releasing molecules discusses this some more, with some information that probably should be moved to the main CO article. Note that it can diffuse out of the blood into tissue as well. This happens normally, as some CO is produced in the body (endogenously), so it's always present. CO only becomes "bad" when your inhale enough of it to interfere with oxygen transport. An essential thing to understand in biochemistry: the dose makes the poison. --47.146.63.87 (talk) 20:25, 9 March 2020 (UTC)[reply]

Red blood cell § Life cycle: red blood cells have a lifetime of about 4 months in the blood, after which they're broken down. But as I noted above, CO doesn't stay bound forever. The problem is while it is bound, the hemoglobin can't carry oxygen, and meanwhile your cells need oxygen, so if enough hemoglobin gets "poisoned" by CO you start suffering hypoxia. Cool fact: your body produces some CO itself as a signaling molecule. --47.146.63.87 (talk) 06:28, 8 March 2020 (UTC)[reply]

Also worth a read: Heme oxygenase. CO is produced in the metabolism of heme from hemoglobin and other proteins by heme oxygenase which is itself a heme enzyme. This is quite complicated. Pelirojopajaro (talk) 15:55, 10 March 2020 (UTC)[reply]

A wasp on a boat

So I was on the open-air deck of a ferry this weekend and there was a wasp buzzing round my head for quite a few minutes. Not on me (or on anything) but flying round like they do. Which got me wondering... to manage that, does a wasp have to fly really fast? Because the boat's moving at some speed, and if the wasp isn't resting on the boat or something on it, surely to keep pace it has to be circling at the same speed? Amisom (talk) 18:36, 7 March 2020 (UTC)[reply]

It would have to be flying fast to the same degree that you were experiencing any wind caused by the ferry's motion.

Consider that if you are inside an airliner travelling at 500mph, and walk forward at 5mph, then you are walking at 505mph relative to the ground, but you are not having to expend any unsual energy. On an open ferry, the superstructure is dragging some air along with it, so at, say, 20 knots (23mph) neither you not the wasp are likely moving through the local air at that speed. Moreover, that disturbed air will have turbulance and eddies, and insects that have been honing their flying abilities for more than 150 million years are probably very good at sensing and exploiting air currents to their advantage.

All that aside, according to this a common type of wasp can fly (through the air) at up to 30mph. {The poster formerly known as 87.81.230.195} 90.202.210.25 (talk) 21:02, 7 March 2020 (UTC)[reply]

The scenario reminds me of the old joke about a guy transporting birds in a truck, and is over the weight limit, so he keeps banging on the wall of the truck, to startle them and keep them flying. ←Baseball Bugs ^{What's up, Doc?} carrots→ 23:35, 7 March 2020 (UTC)[reply]

You're standing on Earth, which is rotating at about 1,000 miles per hour. That translates to about a quarter mile per second. Yet, if you jump up in the air for a second, the ground does not move a quarter mile under you. ←Baseball Bugs ^{What's up, Doc?} carrots→ 23:38, 7 March 2020 (UTC)[reply]

That's not really the same physics: in the case of the wasp, the relative airspeed depends on how much the air in the slipstream around the boat is co-moving with the boat, which is a question of complicated fluid dynamics and friction; and in the case of the Earth rotating, that's a scenario that is mostly defined by inertia and conservation of angular momentum; and although we can draw some parallels, it's misleading to say that they're well-described by the same physical model. Of course, the laws of physics are the same in both cases, but the dominant effect is different. Nimur (talk) 15:00, 10 March 2020 (UTC)[reply]

Sure. And if you jump up, and there's a strong wind gust, you might well not land precisely where you began your jump. Although you wouldn't be a quarter mile away unless maybe a tornado came along around then. Obviously, a small insect is going to be impacted by the wind quite a bit more than we would be. ←Baseball Bugs ^{What's up, Doc?} carrots→ 16:28, 10 March 2020 (UTC)[reply]

March 8

If IVF plus embryo selection for desirable genes will eventually become a reality, would it be practically possible for someone who previously got a bilateral epididymectomy to likewise engage in this?

If IVF plus embryo selection for desirable genes will eventually become a reality, would it be practically possible for someone who previously got a bilateral epididymectomy to likewise engage in this--specifically in IVF plus embryo selection for desirable genes?

Basically, I'm thinking of screening embryos' genes to determine which embryos have genes that indicate a greater likelihood of them developing desirable traits if they will be subsequently implanted and born. I am well-aware that this currently isn't a reality but that it probably will eventually become a reality. I am simply curious about whether, once this actually becomes a reality, someone previously having a bilateral epididymectomy (but not a bilateral orchiectomy) would in any way create an obstacle to this person doing IVF plus embryo selection using his own sperm and someone else's egg.

Based on the information here, the more embryos that one would produce through IVF, the more potential that one would have in selecting embryos for traits such as intelligence/IQ (based on these embryos' genes) due to the fact that, with more embryos, one would have a larger number of embryos to choose from and pick the best one(s):

https://pbs.twimg.com/media/B0VFZjPIQAA7ok1.png

Specifically, though, I'm wondering if previously having a bilateral epididymectomy done would in any way prevent or interfere with a man's ability to create a large number of (implantable) embryos through IVF. Again, if there are less embryos to choose from, the potential gains from embryo selection for traits such as intelligence/IQ would be less than if there are more embryos to choose from. Also, again, I'm well-aware that this isn't actually technology that's fully developed right now, but this technology might nevertheless be successfully developed and commercialized, say, 20 or 30 years down the line. 68.96.93.207 (talk) 01:08, 8 March 2020 (UTC)[reply]

Looks like Futurist is editing logged-out again. In any case, read Eugenics. ←Baseball Bugs ^{What's up, Doc?} carrots→ 01:27, 8 March 2020 (UTC)[reply]

What exactly is wrong with eugenics if it is actually done non-coercively, though? I mean, when someone looks for a sperm donor or egg donor based on various desirable traits (such as intelligence/IQ, lack of criminality, great personality, lack of mental illnesses, et cetera), wouldn't they also be practicing eugenics? I mean, they're choosing whom to reproduce with based on various desirable traits because they want to increase the odds of their children having the same or similar traits. 68.96.93.207 (talk) 02:34, 8 March 2020 (UTC)[reply]

You're assuming that those traits are at least significantly genetically encoded. Also, define intelligence. And "great personality". And what counts as a mental illness? --Khajidha (talk) 16:04, 10 March 2020 (UTC)[reply]

By the way, I was asking about the logistical and practical feasibility of this following a bilateral epididymectomy. I consider the morality debate over non-coercive eugenics to already be settled as a result of people choosing their sperm donors or egg donors based on desirable traits. 68.96.93.207 (talk) 02:41, 8 March 2020 (UTC)[reply]

This is exactly the kind of thing that creeps me out with IVF. (Also the math in your link is bad, the high IQ gains will be much smaller.) 93.138.43.92 (talk) 19:54, 9 March 2020 (UTC)[reply]

Seems to me you're needlessly bundling two independent questions: whether fertilization in vitro + embryo selection can be used for eugenics, and whether viable sperm can be obtained without a working epididymis. Given that you start by assuming that the answer to the first question is yes, why not ask the latter more simply? —Tamfang (talk) 09:04, 11 March 2020 (UTC)[reply]

Navel Orange with Soft Spot

I bought a bag of navel oranges and put them in the fruit and vegetable compartment in my refrigerator. I noticed that one of the oranges has a soft spot. Should I throw the orange away without peeling it, or is it safe to peel the orange and determine after peeling it whether the orange is fit for human consumption?

Robert McClenon (talk) 03:36, 8 March 2020 (UTC)[reply]

If in doubt / Throw it out. Or, at least, ask the fruit guy at your grocery store. ←Baseball Bugs ^{What's up, Doc?} carrots→ 03:46, 8 March 2020 (UTC)[reply]

User:Baseball Bugs - I can ask the produce person the next time I am at the store, but that isn't relevant to the situation at hand, which is that the oranges were in a bag, and I bought the bag and brought it home, and the soft spot was only in view when I opened the bag. Robert McClenon (talk) 14:51, 8 March 2020 (UTC)[reply]

I'm not talking about returning it for a refund (a la Kramer) but just to get his expert opinion. ←Baseball Bugs ^{What's up, Doc?} carrots→ 14:53, 8 March 2020 (UTC)[reply]

Oranges are segmented under the skin. If you can peel the orange and determine which segments are soft and not nice to eat then discard those and enjoy the remainder. I say this as a person who eats overripe black bananas, bruised apples, slightly mouldy bread, cake and cheese and is still healthy. There is far too much food wastage already to justify throwing anything away because it is partially uneatable. Richard Avery (talk) 07:34, 8 March 2020 (UTC)[reply]

User:Richard Avery - I am interpreting that as advice to go ahead and peel the orange and eat the sections that are good and throw out the sections that are questionable. Robert McClenon (talk) 14:51, 8 March 2020 (UTC)[reply]

Precisely. Richard Avery (talk) 16:23, 8 March 2020 (UTC)[reply]

I'm sorry but there is not enough food wastage in the world. I have often eaten slightly stale bread, however I totally subscribe to "when in doubt throw it out". Food "waste" is also known as "fertilizer". Fertilizer is not wasted food, but is part of the natural cycle of life. If there is not abundance in the human world, there is poverty. When the total amount of food produces a situation of hunger, inevitable shortage results in starvation. Abundance of food is possibly the most important thing in the world as far as humans are concerned. If you are running out of food, and the orange does not taste bad... eat it. If you've got no fear of running out of oranges... it will make a fine houmous. ~ R.T.G 17:03, 11 March 2020 (UTC)[reply]

I don't want to cross the medical advice line but since the statement was made..... Although I dislike food waste as well, and often eat food well past its prime including part of the food where some is too bad to eat, I would urge caution with anything mouldy. The problem with fungi is the bit you see may be only be a small part of the whole. Depending in the type of food, there could easily be significant growth you cannot see. The general advice is it's fine to cut off the mouldy bits of most hard food albeit cutting off significant extra [4]. Further 'I didn't get sick after eating it, so I'm sure there was no harmful effect', is probably not a safe bet. A number of fungi produce Mycotoxins like Aflatoxin. While these can have acute effects, there is also evidence of effects from chronic exposure, particularly as carcinogens. So while it may not kill you outright, regular consumption may have an appreciable increase of your risk of liver cancer (as an example). The risks of chronic negative effects is probably not just from fungal growth either. Nil Einne (talk) 13:06, 8 March 2020 (UTC)[reply]

I have the orange still in the refrigerator. My thinking is that, at 4 C, any mold or whatever (and I don't know if it is mold at this point) isn't likely to spread to a neighboring orange, and that I can peel it when I get it out of the refrigerator, and see what it looks like inside. Robert McClenon (talk) 14:51, 8 March 2020 (UTC)[reply]

My experience is that mould (BrE spelling) on fruit in a refrigerator does still spread, albeit more slowly than at room temperature. That said, a soft spot on an orange with no other aberrance doesn't necessarily indicate the presence of mould – it might just be where a recent inadvertant blow has softened the flesh. It may however provide an easy route for mould to enter. Why not just peel the orange immediately, inspect it, and eat however much of it appears wholesome? If in doubt, assign it to the compost. It's only one orange, after all. {The poster formerly known as 87.81.230.195} — Preceding unsigned comment added by 90.199.211.248 (talk) 23:56, 8 March 2020 (UTC)[reply]

When I was a kid, my dad had both a greengrocer's shop, and a hobby of making jam and marmalade. It was years before I realised you could get an orange that was intact around the whole surface - any soft or doubtful oranges left in the shop on a Saturday would come home, be sliced in half and then the good half went in the marmalade pan.

Oranges are segmented inside. If they suffer impact damage to the outside near the equator, this will affect a segment or two. It's a while before it spreads. If they're damaged at the ends, this can affect all the segments quite quickly.

The moulds on citrus tend to be quite specific: most moulds just won't attack fresh citrus, until the skin is damaged or the internal acidity is reduced. So mostly we see Penicillium sp., particularly P. digitatum (green mould) and P. italicum (blue mould). There are a couple of less-common others too: Monascus sp. (typically M. purpureus, which is traditionally used in China for food production) and (emerging recently in the US because of intensive farming and storage practices) Mucor sp., which never used to be an issue until we starting storing low-acidity citrus for ridiculous lengths of time.

So, don't eat citrus which tastes bad. But otherwise, get in there. Remove the affected segments, and don't expect a bruised orange to keep past a day (take the segments out and put them in the fridge). But if you're going to worry about moulds in food, don't start with citrus (you can eat a whole lemon that is covered with green mould and it won't harm you - in the Ukraine it might even be used to cure an infection). Worry about aflatoxins in nuts first. Be really wary around anything "pickled" in oil (you can't pickle stuff in oil). Never trust any food advice in the US, because the whole system is corrupted by the destructive influences of mega-scale farming. Certainly don't leave European regulation in favour of handing over national control to the US! But citrus really are the least of your worries. Andy Dingley (talk) 15:07, 8 March 2020 (UTC)[reply]

So, don't bother consulting your grocer face-to-face - just trust the unreferenced advice of a random internet user as to what's safe to eat and what isn't. ←Baseball Bugs ^{What's up, Doc?} carrots→ 17:09, 8 March 2020 (UTC)[reply]

A grocer, whose livelihood depends on selling as much produce as possible, would of course never advise one to discard suspect but actually wholesome fruit and buy replacements (*cough*). {The poster formerly known as 87.81.230.195} 90.199.211.248 (talk) 00:01, 9 March 2020 (UTC)[reply]

Why should OP trust the unreferenced advice of a random internet user as to whom to ask? 89.172.59.101 (talk) 00:21, 9 March 2020 (UTC)[reply]

There is no substitute for a face-to-face with the grocer. At my store, I have often gotten good advice from the produce manager. That's why I'm telling the OP to do what I would do. ←Baseball Bugs ^{What's up, Doc?} carrots→ 01:06, 9 March 2020 (UTC)[reply]

The unregistered editor asks, "Why not just peel the orange immediately, inspect it, and eat however much of it appears wholesome?" (And if you're an unregistered editor, you aren't previously known as anything, unless you are editing logged out, in which case you aren't an unregistered editor.) Because I wasn't hungry at the time, and was just putting the oranges in the refrigerator. (Yes, I could have peeled the orange anyway and left the good segments in the refrigerator for later in the afternoon or evening.) Robert McClenon (talk) 02:07, 9 March 2020 (UTC)[reply]

Is your health worth the risk of eating a possibly bad orange? ←Baseball Bugs ^{What's up, Doc?} carrots→ 03:39, 9 March 2020 (UTC)[reply]

Oranges should be discarded as soon as they start to become soft. Count Iblis (talk) 06:42, 9 March 2020 (UTC)[reply]

Poop

What part of the brain causes the urge to poop in a human body? --Thegooduser Life Begins With a Smile :) 🍁 03:46, 8 March 2020 (UTC)[reply]

This is a leading question. The urge comes from one's gut; more specifically, from the nerves in the rectal muscles upon sensing rectal distention as caused by fecal mass descending from the colon. An alert signal is sent to the brain, which is helpful for exercising voluntary control, but not essential for the function. See further our article on Defecation. --Lambiam 09:39, 8 March 2020 (UTC)[reply]

I think his question was what part of the brain "receives" the urge to poop. 67.175.224.138 (talk) 15:03, 11 March 2020 (UTC).[reply]

It depends on where your brain is. ←Baseball Bugs ^{What's up, Doc?} carrots→ 17:09, 8 March 2020 (UTC)[reply]

The gut has its own brain. Its relatively new or lesser known discovery. See Enteric nervous system and Intestinal epithelium, and maybe try some videos, [5][6][7] ~ R.T.G 21:43, 11 March 2020 (UTC)[reply]

Here is a more advanced complete walkthrough of the whole system... [8] ~ R.T.G 22:12, 11 March 2020 (UTC)[reply]

Several parts of the brain may be involved. You might find Figure 1 in this source useful. It's a 2014 paper entitled "Brain and Gut Interactions in Irritable Bowel Syndrome: New Paradigms and New Understandings", but I think the same parts are involved in non-pathological cases. 86.157.60.106 (talk) 23:00, 11 March 2020 (UTC)[reply]

March 11

Why in USA it isn't recommended to put masks on?

Why in USA it isn't recommended to put masks on? (to avoid covid19) "As of February 26, 2020, face masks are not recommended for the general public in the US. Some health facilities require people to wear a mask under certain circumstances".ThePupil (talk) 02:28, 11 March 2020 (UTC)[reply]

The so-called experts are saying they are best used by the ones who are sick and by the ones closely caring for them. ←Baseball Bugs ^{What's up, Doc?} carrots→ 04:20, 11 March 2020 (UTC)[reply]

There is some logic to that. Whether it is the truth is another matter. There's no doubt that if you are spraying droplets of virus infested spit and phlegm around the place that wearing a mask will tend to catch some of the droplets. But I suspect the claim that healthy people do not reduce risks to themselves by wearing masks is driven more by hope and a wish to preserve mask stocks, than actual evidence. Of course providing masks to those who definitely need them, as opposed to a healthy individual, does have a benefit for the healthy, but it is a second order effect. Greglocock (talk) 04:27, 11 March 2020 (UTC)[reply]

Hence my use of "so-called". ←Baseball Bugs ^{What's up, Doc?} carrots→ 06:57, 11 March 2020 (UTC)[reply]

Health authorities in France, New Zealand, UK etc. all say there is no evidence that wearing a mask protects you (as in "there is no evidence that faith healing works" - "no evidence that" does not mean "we have not looked" but rather "we looked and found nothing but proving a negative is hard"). The possibility are hence

the advice is correct
the advice is wrong because scientific evidence is lacking
local health authorities are all incompetent and fell for WHO disinformation
local health authorities are all conspiring to lie to the public (and no journalist has found a whistleblower yet)

I have no idea how likely 1 or 2 are, but I am pretty damn sure that those are much more likely than 3 or 4. Tigraan^{Click here to contact me} 08:42, 11 March 2020 (UTC)[reply]

I think 3 also requires a vast overestimation of how much the US CDC cares about what the WHO says. As I said below, IMO this also requires that we make assumptions that they were doing this long before the COVID-19 outbreak since the advice is consistent with that for seasonal influenza, or that COVID-19 is different and this is known but being ignored. Nil Einne (talk) 09:12, 11 March 2020 (UTC)[reply]

(EC) This discussion reminds me somewhat of the discussion a few weeks ago about whether COVID-19 is airborne. While COVID-19 is new, and there's still a lot we don't understand about it, as I understand it the general assumption is spread is likely to be similar to other respiratory diseases, albeit one with likely very limited immunity and where a lot about when, who and how easily it infects etc is still fairly unknown. (See e.g. [9] for an example of uncertainty.)

Therefore the face mask stuff tends to come back to what we know about their use with other respiratory diseases. And there seems to be little evidence that surgical type face masks worn by health individuals in public helps with such diseases, seasonal influenza being the obvious example. To be clear, this means there is an absence of evidence not that there have been good studies demonstrating they are not effective.

Many epidemiologists and others who study how such diseases spread, how to protect against them and observe human behaviour tends to believe they will be of little benefit in healthy individuals especially when many people don't know how to wear them correctly, may not change them frequently enough, etc. One of the most common suggestions is that they may discourage people from touching their faces but the counterpoint is that with at least some people they may actually do it more to adjust the mask etc. I think there is also a concern such masks may give a false sense of security and reduce compliance with good hand hygiene, which is believe to be of significantly greater benefit.

There seems to be some limited evidence of a benefit for correctly wearing such masks by healthy individuals when living in a household with an infected person and combined with good handwashing. [10] [11] [12] [13] [14] Possibly also when people are living in a crowded setting in general [15]. Note AFAICT, such studies generally did not find benefit for masks alone without handwashing, and they also generally included instructions etc on mask use. These studies are also I think, taken as evidence that such masks may be of benefit to protect health care workers who may regularly be coming into contact with infected individuals. (And are already supposed to be practicing good hand hygiene.)

It's worth noting that while the current situation may be somewhat unprecedented, if we get back to the earlier point, it isn't completely unique. If health authorities had good reason to think healthy individuals wearing masks in the general public would have a significant benefit for regular seasonal influenza, there's a good chance it would have been recommended by at least some, since there's no reason why supply couldn't have been adapted to cope with the demand. Possibly even during something like the emergence of H1N1, supplies could have coped with demand. In addition, it's likely at least some working on pandemic planning would have recommended more massive stockpiling to to prepare for something such as this, if they felt their use among healthy individuals should be encouraged. Note that there are plenty who recommended, long before this outbreak, that people with symptoms of respiratory illnesses/flu should wear masks as is common in a number of Asian countries.

See e.g. [16] [17] [18] [19] [20] [21] [22] [23]

As a final point, having sort of an interest in medical and health topics for a while, one thing I feel a lot of people don't appreciate is that in reality, a lot of what we believe and is put into practice is not based on particularly strong evidence. The relationship between diet and acne is perhaps a classic example of this. A loosely related example is there's always been controversy and recently been a strong move against antibacterial soaps based on the lack of evidence of any real benefit, and fears of possible harm from their widespread use. But I also came across this interesting example when searching this answer [24].

Nil Einne (talk) 09:12, 11 March 2020 (UTC)[reply]

Off-topic but: a lot of what we believe and is put into practice is not based on particularly strong evidence - That is true of science in general. A standard experimental paper (at least in physics) will contain "methods", "results" and "analysis" sections; usually you can trust that if you follow the steps of the "methods" section you will end up with what was described in the "results" section, but "analysis" is often a pompous word for "we scratched our heads trying to figure it out, here goes the least crazy of our hunches". Of course in medicine there are additional ethical problems. If people are dying left and right from an epidemic, you might want to aggressively test highly-speculative remedies, whereas in physics, you can almost always wait for more confirmation.

The experimental method is still the best way we have found for figuring out things, but our state of knowledge about the world is a lot a shades of grey between "we know for sure that thing" and "we have no idea whatsoever to explain that thing". Tigraan^{Click here to contact me} 13:28, 11 March 2020 (UTC)[reply]

(EC) One additional point. It's possible that some feel based on available evidence and understanding, healthy people wearing masks has a greater chance of being beneficial than of causing harm. Even after consideration of the relative risks and level possible of harm and benefit. This evaluation would likely be based both on the possible benefits of reduced transmission to said healthy people, and also reducing transmission from people who think they are healthy but aren't. (But also considering the chance it may increase transmission due to people adjusting their masks, masks collecting contaminants, a false sense of security, distracting from hand-washing advice etc.)

So the precautionary principle would suggest healthy people should be encouraged to wear masks. But this isn't being happening due to a recognition supplies cannot cope with it and so they need to be reserved for those cases where the chance of benefits is far greater. (And it doesn't happen for seasonal influenza given factors like the low estimation of possible benefit, possible differences in number of carriers and people at risk of infection, limited number of people who may follow such advice and additional confusion and uncertainty that may result.)

However this is a fairly different issue from suggesting authorities are being misleading about the evidence. Although such views could be one the reasons why some authorities require mask wearing even for healthy individuals e.g. I believe in HK and some other countries it's required to ride on their mass transport systems. (But there are other factors that may be at play e.g. the difficulty of enforcing a requirement to wear masks on people who know they have symptoms of a respiratory illness, compared to simply requiring it from everyone.)

Nil Einne (talk) 13:50, 11 March 2020 (UTC)[reply]

The advice not to touch your face and to wash your hands is probably also not based on experimental evidence of its efficacy, but nevertheless appears sound if contact transmission from touching contaminated surfaces is a major factor in spreading the infection. If it is the major pathway, then wearing a mask is probably not going to help much more in reducing the spread. It is also plausible enough that reusing masks may even increase the wearer's risk. I'd be surprised though if wearing proper and regularly changed masks would not prove to somewhat reduce the risk for someone who meticulously follows the other WHO advice. --Lambiam 14:01, 11 March 2020 (UTC)[reply]

Yes, this is important for such public health advice. Surgical masks only work when you wear them properly and change them regularly and properly. If people don't don't do this they're useless, and may be worse than useless because they may cause people to feel a false sense of security and hence not follow other advice (risk compensation). When evaluating interventions that people perform themselves we have to look at differences between "perfect use" and "typical use". (This is relevant for many interventions, for example birth control methods.) --47.146.63.87 (talk) 03:59, 12 March 2020 (UTC)[reply]

What I always heard about surgical masks is they help prevent you from infecting other people (e.g. by coughing: the mask stops the droplets). They don't stop the other people from infecting you, i.e. airborne viruses travel right through it. They help you stop touching your face with your hands though, something I do all the time out of habit. 2601:648:8202:96B0:54D9:2ABB:1EDB:CEE3 (talk) 05:09, 12 March 2020 (UTC)[reply]

COVID query

If this coronavirus spreads around the world, and it seems like it most certainly will, will it just disappear then? Is this virus set to be a new recurring incurable disease among humans as more familiar flus are?

This question doesn't seem to be asked a lot. People are more worried about dying today... However, influenza, which COVID is being called though it apparently is not, mutates at a rate which prevents it being cured by vaccination, or something like that, hence the new concoction yearly in the flu jab... I understand from reading about tundra that the deadly "Spanish Flu" has been detected in bodies thawed from the permafrost such that it is a concern among archaeologists and palaeontologists finding remains in the arctic circle. I also am led to believe that bubonic plague persists, even in America... So what is the outlook here? I'm not going to say "if" it is beyond our control. Will COVID persist as an irritant? As a deadly disease? Will it disappear? Expectedly, I cannot seem to find this enquiry in the new reports... without digging ten feet into muck which I've already turned over several times.

Any response appreciated, thank you, ~ R.T.G 16:45, 11 March 2020 (UTC)[reply]

Coronaviruses were first discovered in the 1960s, so they're obviously not going away anytime soon. ←Baseball Bugs ^{What's up, Doc?} carrots→ 17:00, 11 March 2020 (UTC)[reply]

To be clear, the virus that causes CoVID-19 is the same species as SARS, the same family as some common cold viruses but a completely different order from influenza virus. Not closely related. Rmhermen (talk) 18:05, 11 March 2020 (UTC)[reply]

You meant "group", not "species", which has a very specific meaning in biology. (The concept of a species is not really well-defined for viruses anyway.) --47.146.63.87 (talk) 07:00, 12 March 2020 (UTC)[reply]

Well, Wikipedia says there is a plague season in Madagascar! As often with texts about infectious diseases, the truth is a good bit less disturbing than the headline, but the headline is not wrong. I'll point out that we don't worry too much about the plague and that may not be a reckless judgment. If you're look for a book about this sort of thing, I recommend David Quammen's Spillover. 93.136.81.202 (talk) 03:07, 12 March 2020 (UTC)[reply]

Bubonic plague (caused by Yersinia pestis) is definitely still around, but it's not that big a public health problem today, since it can be slowed down with hygiene and treated with antibiotics, neither of which were available (much) back in the middle ages. Covid-19 does seem to be able to survive in air "up to 3 hours post aerosolization".[25] There are a bunch of temporary measures announced like closing schools for the next 2 weeks, but if anything the pandemic will be even worse 2 weeks from now than now. Better start stockpiling loved ones ahead of the outbreak. 2601:648:8202:96B0:54D9:2ABB:1EDB:CEE3 (talk) 04:18, 12 March 2020 (UTC)[reply]

Maybe, maybe not. We don't do predictions on the ref desk, and predictions at this point are going to be very uncertain. If we can control its spread, we might be able to contain it eventually, and then it will just "burn out" if it's unable to infect anything new. Plague is an example of a "direct zoonosis". It can infect numerous species as-is, so it circulates in natural "reservoirs" of animals, and can infect humans from there. To eradicate it we would have to immunize, kill, etc. all infected animals. But there is no sustained human-to-human transmission. Influenza is a whole big family of viruses that circulate in numerous strains among different species and, as you noted, mutate rapidly (because they're RNA viruses), which is why it's such a nasty thing to get a handle on. Smallpox and rinderpest, the two diseases we've eradicated, were eradicated with mass vaccination; the latter only affected various large mammals, which can't travel long distances easily, another helpful factor. However, we're still cursed with the descendant of rinderpest: measles. --47.146.63.87 (talk) 07:00, 12 March 2020 (UTC)[reply]

There was a reddit ama yesterday by an NHS critical care doctor that has what looks like good info: [26] 2601:648:8202:96B0:54D9:2ABB:1EDB:CEE3 (talk) 09:51, 12 March 2020 (UTC)[reply]

flowers with 2 differnt sexes and with one sex

How do I find a list of flowers that have 2 different versions (male and female)? How do I a list of flowers that have only one versions (which is both male and female)? In the first case I want to find pictures of each of the versions.

Thanks a lot, Rami (talk) 19:33, 11 March 2020 (UTC)[reply]

Plant reproductive morphology looks like the starting place you want. Most flowers are "perfect", having both male and female sex organs, so a list of the latter will be most flowering plants. --47.146.63.87 (talk) 04:02, 12 March 2020 (UTC)[reply]

March 12

COVID 19, again

1. Does the self-isolation of two weeks really work? If man A shows symptoms and was in contact with man B. Man B is asked to self-quarantine for 14 days but has already been exposed for a week, his family in his home then become carriers and as they too are self-isolating for two weeks they too are prevented from spreading it, but in the week that man A and man B were in contact each could have been in contact with thousands of people on trains, busses and other. SO by the time they self-isolate, thousand are already carriers and don’t know and go on to spread the virus to thousands, I can’t see how the cycle is broken with self-isolation. Please let me know what I am missing.

2. If I am a possible carrier and self-isolating, when I start to show symptoms, how do I treat the illness? I understand that I should not leave home and should not go to hospital unless vital, so how do I treat this at home? Some may not show such bad symptoms. Thanks. Anton 94.198.187.35 (talk) 11:40, 12 March 2020 (UTC)[reply]

You should look at the reddit thread that I linked further up. 1) yeah it's tricky, and this stuff of shutting down events with more than 100 people seems to miss that transit stations have that many people in them all the time during commute hours. If you take a train to work you are probably in a 100+ person "event" twice a day. BART (commuter train here in California) traffic has apparently dropped significantly in the past few weeks. 2) The Dr. in the reddit ama above addressed this question but if I paste what he said (tldr: nothing too surprising), the "medical advice" police here on RD will go berserk. So it's best to just look there yourself, since it's an informative thread. 2601:648:8202:96B0:54D9:2ABB:1EDB:CEE3 (talk) 12:03, 12 March 2020 (UTC)[reply]

The OP looks like they're in the UK. Rather than follow random social media contributors, the advice here is to use NHS 111, by phone or [27]. Bazza (talk) 12:12, 12 March 2020 (UTC)[reply]

Nutrition

Can I survive on just rice, ground soy and fish? — Preceding unsigned comment added by 193.64.221.25 (talk) 14:33, 12 March 2020 (UTC)[reply]

For a short time yes, but not indefinitely.