Wikipedia:Reference desk/Archives/Science/2021 July 12

= July 12 =

Exposed to rabid bat
200 people exposed to rabid bat at zoo and will get vaccinations. Is being "exposed" to a rabid bat dangerous, if it doesn't actually bite you? Like can it shoot rabies beams out of its eyes if it stares at you, or anything like that? I was nowhere near this incident but it wouldn't have occurred to me to seek emergency vaccination just because I was near a rabid bat, without being in actual contact. Wondering if I'm being cavalier. I looked at wp's rabies article and the parts about transmission didn't make it sound like non-contact infection was really a thing, and if I was bitten at night I like to hope I'd know it. Otherwise it seems unsafe to camp anywhere there might be bats, which is almost everywhere. But maybe I missed something. Thanks. 2602:24A:DE47:BA60:8FCB:EA4E:7FBD:4814 (talk) 00:22, 12 July 2021 (UTC)


 * This is probably a case of the authorities (and the the facility, with its resulting liabilities here) embracing the precautionary principle, since the difference between prophylactic and post-symptomatic action can render to rather dramatic differences in probable outcomes when it comes to treatment for rabies. It is possible, though uncommon, for rabies to be transmitted without a bite, notably where infected saliva makes contact even with a very slight scratch or ulceration, or with the mucosa of the oral, nasal, or ocular cavities.  Additionally, many bat species are diminutive enough in size that a bite may not be in all instances apparent from tactile/nociceptive sensation or even visual examination.  The linked story leaves open rather a lot of questions about the context of the facility and circumstances in which these visitors were overnighting, but given the apparently enclosed environs which these people shared with the bats, I am not surprised health officials felt vaccination was advisable. Here is a delphi method study which investigates when post-exposure vaccination is most particularly warranted: the study does emphasize a rather high level of caution with regard to bats, even when the type of exposure is unknown. Snow let's rap 00:48, 12 July 2021 (UTC)

Our article at Rabies transmission says that "Transmission may rarely occur via an aerosol through mucous membranes; and might conceivably endanger people exploring caves populated by rabid bats. However, aerosol transmission of rabies has not yet been well documented in the natural environment." and both halves are referenced. So, why err on the side of caution? Because active rabies is a death sentence. The treatment is not anywhere near as bad as what it used to be like, so there's really no need to take the risk, even if it's a small one. Matt Deres (talk) 13:58, 12 July 2021 (UTC)


 * Because active rabies is a death sentence. Just to emphasize this: there have been a total of 11 recorded people who have survived rabies without the vaccine throughout human history, all of whom received a a somewhat controversial treatment since 2003 (with 10 of them occurring since 2014). For context, about 59,000 people die of rabies worldwide each year. If we just look at the disease since the advent of that treatment, then that's a survival rate of 0.001097% (just slightly over 1/1000ths of a percent), a survival rate which is only achieved through the use of a therapy which requires a 17-page guide with 22 steps for the physician to implement, and which requires the presence of significant medical resources (something to which most victims have no access). Also note that the therapy had been attempted 41 times, meaning it's effectiveness stands at about 27%. So even with therapy, most patients die.
 * The morbidity of untreated rabies is 100%. This warrants the taking of extreme precautions, even when the risk of actual infection is low. ᛗᛁᛟᛚᚾᛁᚱPants   Tell me all about it.  14:30, 12 July 2021 (UTC)

Flake of lead paint in the human body
If a child, or anyone, ingests flakes of lead paint, what exactly happens to the flake? I’m sure stomach acid causes lead to be released from the flake, but is the flake physically destroyed, and/or is it invariably flushed out of the body? One thing I’m worried/wondering about is if the flake could adhere to the wall of the small intestine, releasing lead over a longer period of time.Rich (talk) 01:01, 12 July 2021 (UTC)
 * Unfortunately, this question runs up against the prohibition against offering medical advice, particularly insofar as you seem to have a personal concern about it. I will go as far as to say that in cases of ingestion, acute lead poisoning can have significant effects even if a solid mass of the type you speculate about passed completely through the GI tract. Obviously the amount of exposure here is of great significance, but one thing we absolutely cannot speculate about here is whether or not the amount likely to be present in a paint chip is likely to be of idiopathic concern to a particular person. If you or someone you know has consumed lead-based paint, it is best to present these questions, along with more particularized details, to a licensed physician/health care provider, or at least the poison control hotline in your locality. Sno<b style="color: #b2dffe;">w</b> <b style="color: #d4143a">let's rap</b> 01:16, 12 July 2021 (UTC)
 * , please read Lead poisoning and Lead paint and Blood lead level and Chelation therapy, and read the references too. If your interest is theoretical, you will learn a lot. If your interest is practical, please have the exposed person seek competent medical attention immediately. <b style="color:#070">Cullen</b><sup style="color:#707">328  Let's discuss it  01:30, 12 July 2021 (UTC)
 * why are you so obnoxiously trying to seize the high ground? Stop this implication that I should have known to read chelation article before asking a question here.(if indeed the chelation article discusses adherence of paint flakes to the intestinal wall, as you imply, since you want me to read it. Since my interest is not what you have decided to call “practical”, there wasn’t a reason for me to look at the chelation article.Rich (talk) 01:42, 12 July 2021 (UTC)
 * Rich, I really don't think that response is appropriate or helpful here. Cullen was clearly making a good faith attempt to connect you with the information you sought while also adding a note of caution out of presumably real concern for you or a loved one if your interest related to anything more than the abstract--which was not at all an unrealistic concern given your original post included an implication that you were "concerned" regarding the prospect of lead being retained in the GI tract. Beyond that, I don't see anything in Cullen's response which suggests that he is some way trying to high road you here: even re-reading his comments, I struggle to understand what you even mean by that in this context. Given your ambivalent response and the proscription against providing medical advice here, I was tempted to just blank this entire thread after your second post. But I'm going to take the approach of hatting the discussion instead, with a request to my fellow ref deskers not to reverse this, since I don't think engaging with you on this topic is prudent, since it involves rather complicated pathophysiology and I have concerns about how you will assimilate the kind of gung-ho speculation such questions sometimes receive here.  If your interest really is purely abstract then there are forums where you will find no shortage of people willing to give you their two cents, but I urge you should be careful what you internalize from any feedback you receive in open forums online.<b style="color: #19a0fd;">S</b><b style="color: #66c0fd">n</b><b style="color: #99d5fe;">o</b><b style="color: #b2dffe;">w</b> <b style="color: #d4143a">let's rap</b> 02:00, 12 July 2021 (UTC)

Categorizing colors as having properties analogous to phonemes and music
I wish I could explain this, but:


 * The colors red, yellow, and green have an appearance that is analogous to the sounds of B, D, and G and legato music.


 * The colors cyan, blue, and magenta have an appearance that is analogous to the sounds of P, T, and K and staccato music.

Any better description each of the above groups of 3 colors I mentioned?? Warm and cool is not a good choice because green is cool and yet it is categorized with red and yellow here. (Interestingly enough, both black and white are in the category I put cyan, blue, and magenta in; even though they are complete opposites.) Georgia guy (talk) 01:33, 12 July 2021 (UTC)


 * You will probably be interested in our article synesthesia (though if you know the meaning of term phonemes, I would expect you are at least vaguely aware of this perceptual phenomena). In short, you may have a particularly noticeable association between visual and auditory qualia in these categories, a phenomena which is by no means uncommon, but particularly pronounced for some individuals. However, it is probable, insofar as our yet-cloudy understanding of the neurology involved here suggests, that these associations are somewhat more idiosyncratic to you, rather than being products of any shared physical qualities arising from the physical laws with give rise to these disparate sensory stimuli--see also our ideasthesia article in this respect.


 * At least, I believe I am answering your question head on: I admit your wording is a little confusing to me and I am not 100% certain that you are talking about something you perceive in the sensory sense, so much as some abstract mathematical/morphological feature of these phenomena which you believe you have observed them to share in common. <b style="color: #19a0fd;">S</b><b style="color: #66c0fd">n</b><b style="color: #99d5fe;">o</b><b style="color: #b2dffe;">w</b> <b style="color: #d4143a">let's rap</b> 01:47, 12 July 2021 (UTC)


 * It sounds like you're associating colors whose spectrum contains blue (see Primary_color) with aspirated consonants or unvoiced consonants and staccato notes. Do the P sounds in "spin" and "pin" match up with the same colors in your perception? --Amble (talk) 16:34, 12 July 2021 (UTC)


 * Your two color sets are also very similar to Palette 0 and Palette 1 of the 320x200 graphics mode of a CGA monitor; see Color_Graphics_Adapter. If you have spent a lot of time playing computer games on a CGA monitor, that could be a reason why those two sets of colors are strongly associated in your mind. --Amble (talk) 16:45, 12 July 2021 (UTC)
 * I'm talking about voiced/voiceless sounds; to me aspiration isn't important because anglophones don't recognize aspiration as an important property of phonemes. Distinguish the sounds in "spin" and "bin". Georgia guy (talk) 17:37, 12 July 2021 (UTC)
 * It's not necessarily true in English that voicing is important and aspiration isn't important. See for example . The question is: does "spin" line up for you with red-yellow-green or with cyan-blue-magenta? What about "metal", "mettle", "medal", "meddle"? --Amble (talk) 18:04, 12 July 2021 (UTC)
 * All voiceless consonants like up with cyan-blue-magenta. Georgia guy (talk) 19:03, 12 July 2021 (UTC)
 * In American English, "metal", "mettle", "medal", and "meddle" are ordinarily pronounced identically (flapping). So I'm curious whether these are all red-yellow-green for you (because they are realized as voiced), or the ones written with T are cyan-blue-magenta (following the spelling). --Amble (talk) 19:16, 12 July 2021 (UTC)
 * This is about the phonemes themselves regardless of their context. If the phoneme depends on the dialect, then so does what it lines up with. Georgia guy (talk) 19:23, 12 July 2021 (UTC)

Featured picture
Is the crested shriketit considered a beneficial species or a harmful one? Because if you look at its feeding behavior, it's easy to see how it could go either way! 2601:646:8A01:B180:4CF:59F2:CEF2:C1A6 (talk) 02:18, 12 July 2021 (UTC)
 * A cursory search does not turn up anything suggesting that this species is considered a pest or anything other than an organism living in its ecological niche. In fact, some of the little information I could turn up regarding its distribution and status suggest that its numbers are somewhat under pressure from habitat loss. I presume that the detail of their feeding habits that makes you contemplate this question is the fact that they strip bark from trees?  This isn't a super unheard of trait amongst avian foragers and does not in and of itself indicate an especially parasitic relationship with the trees in question.  These behaviours often become problematic in the context where a given organism is an invasive species to a new region that has not evolved in lockstep with it, affording the plants in question time to evolve defense against it (or even a mutualistic relationship) whereas here--though I am somewhat venturing out into speculative territory now--since that is not the case in this instance, it is probable an ecological balance has been established in regard to this behaviour--after-all, in the longhaul any adaptive behaviour which too negatively impacts a species which the bird in question is dependent on as a host to its calories, will be selected against.  That's not to say there are not exceptions to that rule, but bark stripping is, again, not a super uncommon feature among both birds and mammals which predate insects.


 * Of course, in any event, "beneficial" vs. "harmful" species is a highly speculative distinction which may be based on more than ecological concerns, but in any event, I am not seeing anything indicating high levels of frustration with this species in any context, so my best-guess response here is that these birds are generally regarded as beneficial, at least to the extent that any species just going about it's business expressing its behaviours in the ecosystem is generally considered beneficial. Please take all of that with the note of caution that I cannot provide a source for you which itself directly addresses your inquiry, however. <b style="color: #19a0fd;">S</b><b style="color: #66c0fd">n</b><b style="color: #99d5fe;">o</b><b style="color: #b2dffe;">w</b> <b style="color: #d4143a">let's rap</b> 03:03, 12 July 2021 (UTC)
 * By the way, the crested shriketit article currently says "described by ... John Latham in 1801 under the binomial name Lanius frontatus", but the infobox says "Falcunculus frontatus (Latham, 1801)". Needs fixing, otherwise it's unclear which of the two names did Latham actually introduce. 212.180.235.46 (talk) 20:39, 12 July 2021 (UTC)
 * It is correct as written according to the International Code of Zoological Nomenclature (Article 51.3 in the current version of the code). The "(Latham, 1801)" in "Falcunculus frontatus (Latham, 1801)" means that the species was originally described by Latham using the specific name frontatus, with the parentheses indicating that Latham had put it in a different genus to Falcunculus, which is where it is nowadays placed. The text is clear if you know this standard rule, so I would advocate that it is not changed. Jmchutchinson (talk) 10:08, 13 July 2021 (UTC)
 * [un-indent] OK, so the tree damage from the bark-stripping is insignificant and/or is outweighed by the bird eating harmful insects which cause more damage to the tree than it does? Thanks! 69.181.91.208 (talk) 07:54, 14 July 2021 (UTC)

How scientists prepared vaccines against new disease COVID but not old deadly disease HIV?
I always wonder how scientists develop vaccine for novel coronavirus faster than HIV virus which pandemic started around 1980s.

Is this because of corona being short term disease? There is no vaccine for HIV currently source, but recently its vaccine trails begin at Oxford source Rizosome (talk) 19:54, 12 July 2021 (UTC)
 * HIV attacks the immune system in particular, unlike COVID-19. If the immune system is targeted, probably it's a lot harder to create a vaccine.  74.98.192.38 (talk) 20:07, 12 July 2021 (UTC)
 * Have a look at HIV vaccine development. In a nutshell: there are several difficulties due to unusual nature of HIV, compared to most other viruses. Brandmeistertalk  20:08, 12 July 2021 (UTC)


 * Also don't forget that Covid wasn't entirely new, it has significant similarities to SARS and MERS, for which vaccine work had already been done. Fgf10 (talk) 07:51, 13 July 2021 (UTC)
 * Indeed, here is a 2004 review/letter to the editor identifying the spike protein of SARS as a good target for vaccine development (in the abstract's words: the spike glycoprotein [is] a major immunogen and a target for entry inhibitors.) Tigraan <span title="Send me a silicium letter!" style="color:">Click here for my talk page ("private" contact) 12:18, 13 July 2021 (UTC)

Direction of floating in outer space
If Earth's graviational influence extends into outer space and on the Moon in particular, does it mean that any foreign artificial object (or the dead astronaut's body) floating/drifting in the vicinity, would eventually be pulled towards Earth or some other astronomical object for that matter? More generally, would that artificial object or astronaut drifting in the interstellar medium be eventually captured by some gravitational field? 212.180.235.46 (talk) 20:02, 12 July 2021 (UTC)
 * See Hill sphere. --Amble (talk) 20:10, 12 July 2021 (UTC)
 * To attempt to distill this a little for the OP, when you ask "would [body X] drifting in the interstellar medium be eventually captured by some gravitational field?", the answer hinges on the understanding two principles governing the mechanics of gravity: that all bodies of matter (indeed, every quanta of matter) are exerting gravity in relation to one-another, without a privileged frame of reference but that 2) not withsanding this, the influence of gravity falls off rather steeply with the distance between objects (gravity is in fact the weakest of the fundamental forces).


 * So when you ask an open ended query about whether it is inevitable that your hypothetical astronaut will eventually be pulled into an orbital or collisional relationship with any other body in the universe, it is a tough order to say with empirical precision. Now there are definitely some much bigger brains here when it comes to astro- and Newtonian physics, so they may be able tocrunch the numbers down to some more digestible figures, based on established research--in the local sense of our relative place in universe, and what is typical in our immediate neighborhood for density and distribution of bodies of various sizes. But there may not be a reference that quite directly treats your abstract inquiry (paraphrasing: "Over the life of the universe, what is the likelihood that body X, composed of Y (arbitrary physical composition and proportions) will be gravitationally bound to any other body such that it makes contact with or enters into orbit of said object."). Part of the complication is that gravity is so weak as a force, that its not sufficient to overcome the influence of cosmic expansion and prevent an average increase in distances between bodys in the universe in general, so when you ask your question without bounding the factor of time, we begin to see that (as a purely abstract matter) there will be an increasingly large amount of bodies (or at least quanta of matter) which go their own way and may (depending on what model of the ultimate fate of the universe proves to be accurate) never contact other bodies again. When you consider the question across the enormity of what is likely to be the life of the universe, it becomes immensely difficut (indeed, functionally impossible I think it is fair to say with current models and knowledge of the overall distribution of matter in existence) to ascertain with precision which bodies have truly entered into this relationship with regard to all other bodies in the vastness of the universe.  On the other hand, often one could rather readily falsify the premise that such a body has entered this state of existence by observing its short-term probable chance of hitting other known bodies (of established mass, location, and vector), or likelihood of hitting a body within a distribution of bodies with a vaguely known density over an area).


 * The question also hinges on other undefined factors in your inquiry: what do you mean by "captured" here? Does the other body have to be more massive, such that the astronaut is falling into its orbit? Remember, that from the perspective of each body, it is the center that is being orbited, even if it is the smaller object. That is one of the knock-on effects of relativity. Similarly, if they collide, both did so while attracting the other.  But if your question is meant to ask what the likelihood of an object eventually coming to move (at least for a time) in a relationship with another body where it is pulled into a stable orbit, despite all other gravitational influences acting upon it at a given moment of time, then, as discussed above, that is a complicated probabilistic question.  And if we arbitrarily add in the detail that the other body must be bigger, such that it fits the more intuitive/general neacular sense of "capturing" another object with its gravity (which can be easy adopt if one doesn't keep sight of the fact that there are no privileged frames of reference in relativistic mechanics, but which is more of a epistemological/psychological artifact than anything demanded by the physics), you now have another variable to account for: the body in question (particularly a flash frozen human body) may first make contact with many smaller bodies on it's way to being gravitationally "captured" by a larger one.  You could end up with an inverted Ship of Theseus situation wherein the constituent parts of the body are broken down by impacts.  At this point, is each constituent piece one which you want to track inherit the importance of the original body, such that if any piece of it becomes gravitationally bound to another larger body?  I realize the visualization is getting a little macabre here, but I'm afraid it's an inevitable consequence of pondering your question when utilizing your chosen example for a body of matter.


 * In sum, the answer to your query is all of these (admittedly not necessarily super-satisfying) things at once: 1) it depends on some extra information, 2) it depends on what you mean with regard to some of the multiple interpretations of the words and idioms in your inquiry, and even then, 3) it's hard to know with absolute certainty, and even the probabilities would be hard to nail down across all of time, even for a known body with defined qualities that seems to be in the path of no other observable body. <b style="color: #19a0fd;">S</b><b style="color: #66c0fd">n</b><b style="color: #99d5fe;">o</b><b style="color: #b2dffe;">w</b> <b style="color: #d4143a">let's rap</b> 04:26, 13 July 2021 (UTC)


 * If "drifting" means, "to be in free fall", then the two Voyagers are drifting, and the main gravitational influence on them is that of the Sun. If they were brought to a standstill (with respect to the Sun), they would start falling back and might end up being evaporated in its aurora corona. As their speeds exceed the escape velocity ( since they were launched, continuing to do so), they may be expected to continue their voyage to Where No Voyager Has Gone Before. They may eventually get captured by the gravity of some body out there before this universe ends, but probably not within the next few million years and perhaps never. Objects arriving near the Sun from outer space, such as ʻOumuamua, are typically also not captured but continue their journey in a different direction. For such an object to be captured requires just the right course in combination with just the right configuration of several massive bodies (such as the Sun and Jupiter) that is unlikely to arise by chance at just the right time. --Lambiam 13:55, 13 July 2021 (UTC)
 * Solar corona, aurora is near planets. No spacecraft had escape velocity pre-gas giant till New Horizons got it near Earth from its own rockets decades after Voyager. Sagittarian Milky Way (talk) 22:36, 13 July 2021 (UTC)