Wikipedia:Reference desk/Archives/Science/2016 March 28

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March 28

64-hour days

This BBC article has a photograph of a clock (manufactured by the New England Clock Company - see History of Connecticut industry) where the face is divided both into the conventional twelve hours, and 32 smaller units. Does this time system have a name, and is there any more information out there about it? The Hexadecimal time system of John W. Nystrom divided the day into 16 hours, so the numbers read from the clock in question are four times the Nystrom value - it's therefore probably not an implementation of that system. Tevildo (talk) 00:10, 28 March 2016 (UTC)

Date. --jpgordon^{::==( o )} 00:24, 28 March 2016 (UTC)

Yeah, I agree, it looks like a day of month indicator. For one thing, it's dividing the clock into 31 intervals, not 32. And it wouldn't really make sense for it to be 1/64th (much less 1/62nd) of a day even if there were such a time system, because there's no fourth hand to indicate smaller divisions of that interval, and 22.5 minutes is an inconveniently long amount of time to be the smallest interval that a (modern) clock can measure. CodeTalker (talk) 01:02, 28 March 2016 (UTC)

Here is a picture of just such a clock face. --jpgordon^{::==( o )} 01:08, 28 March 2016 (UTC)

That would make sense - so the red hand isn't a second hand, it rotates once a month instead. Is there a name for this type of display? Tevildo (talk) 09:22, 28 March 2016 (UTC)

Complication (horology) mentions a "calendar watch", so maybe it's called a calendar clock? Try searching for information about watch complications. Perhaps there is a more specific name. --Guy Macon (talk) 11:29, 28 March 2016 (UTC)

Does this clock need to be manually corrected at the end of every month that does not have 31 days? Or is there some automatic/mechanical method built in to do so? Deli nk (talk) 13:11, 28 March 2016 (UTC)

I have no idea about that specific clock, but many clocks with date features use Perpetual_calendar technology to get the date correct automatically. SemanticMantis (talk) 16:22, 28 March 2016 (UTC)

See "THE CALENDAR WATCH, EXPLAINED" for the different types of calendar clocks.--TMCk (talk) 16:38, 28 March 2016 (UTC)

And, yes, every month short of 31 requires you advance the hand manually. It's not a huge deal; if you have one of these clocks, you are winding it probably every week, anyway. --jpgordon^{::==( o )}

I found Waterbury Niagara Oak Calendar Shelf Clock, ca. 1911 and 1890's Oak Jewelers Advertising Regulator Calendar Clock, or you can build your own Schoolhouse Calendar Clock with the aid of a kit. So "calender clock" is indeed what it is called. Alansplodge (talk) 21:46, 28 March 2016 (UTC)

Crossing the Bering Strait

If we ignore diplomatic issues, is it possible to drive from the Alaskan mainland (whether Cape Prince of Wales or somewhere else) to the Russian mainland (again, either Cape Dezhnev or somewhere else)? Bering Strait crossing talks only about proposals to build a road or railroad that crosses the strait completely; I'm wondering whether the winter ice is typically thick enough and consistent enough that one could drive a land vehicle such as a truck or snowmobile, or whether one would be restricted to using a boat or aircraft. Nyttend (talk) 01:13, 28 March 2016 (UTC)

Here is one site that indicates that using a land vehicle would not be possible. That is backed up by the last paragraph here Bering Strait crossing#Technical challenges. MarnetteD|Talk 01:21, 28 March 2016 (UTC)

The goggle title for this had me fooled for a moment but the pic shows that, even though it is a Land Rover that made the trip, it didn't "drive" the whole way :-) MarnetteD|Talk 01:25, 28 March 2016 (UTC)

FWIW, Bering Strait#Expeditions says

In March 1913, Captain Max Gottschalk (German) crossed from the east cape of Siberia to Shishmaref, Alaska, on dogsled via Little and Big Diomede islands. He was the first documented modern voyager to cross from Russia to North America without the use of a boat.[7]

and mentions other crossings on skis and on foot. Loraof (talk) 01:30, 28 March 2016 (UTC)

Initial planning of the 1908 New York to Paris Race contemplated motor cars racing across on the winter ice. This proved impractical. Jim.henderson (talk) 01:31, 28 March 2016 (UTC)

They were only supposed to race across the ice of Alaska, from Valdez to Nome. This is what proved impractical. The one car that made it to Valdez returned by boat to San Francisco, and its time was adjusted to compensate for the side trip. Then all the cars went by boat to Russia from there, instead of from Nome. See Hard Driving (1991) by Dermot Cole, ISBN 1-55778-360-8. --69.159.61.172 (talk) 09:52, 28 March 2016 (UTC)

• It would certainly not be reliable, this comment "Although there are no icebergs in the Bering Strait, ice floes up to 1.8 metres (6 ft) thick are in constant motion during certain seasons, which could produce forces on the order of 44,000 kilonewtons (9,900,000 pounds-force) on a pier.[13]" comes from the article you linked to. μηδείς (talk) 01:34, 28 March 2016 (UTC)

• I'd taken that as a reference to summer weather, conditions that would threaten the bridge piers, rather than as a winter-weather situation. Nyttend (talk) 02:49, 28 March 2016 (UTC)

I think it's reasonable to assume that one can say, it is possible under the right conditions to cross using a vehicle with luck, but it is not possible to say there is a set route that is always crossable in the same way at the same time each year. Keep in mind, also, that these floes are not flat. The Hudson and Delaware freeze over at NYC and Philly on occasion, but people don't attempt to drive across. μηδείς (talk) 17:28, 28 March 2016 (UTC)

I suppose there is less ice nowadays than 100 years ago. so, no crossign without a boat.Scicurious (talk) 01:45, 28 March 2016 (UTC)

No, Winter ice maximums in the arctic are relatively unchanged. Summer minimums are lower.

Normal to have one nostril always blocked?

One of my nostrils is always blocked, it switches but it's constantly either one of the other. Is that normal? 2.103.12.92 (talk) 03:49, 28 March 2016 (UTC)

It depends on your specific situation. Giving you a useful answer would require us to make a solid medical diagnosis, and we can't do that over the Internet. Please ring up your local doctor's surgery and get an opinion from an NHS professional. Nyttend (talk) 04:02, 28 March 2016 (UTC)

Yeah, after googling causes of it I was thinking of going to the doctor's to get an allergy test but according to this video it's perfectly normal so I don't know what to believe - https://www.youtube.com/watch?v=BGACvb3Mm60 I'm not asking you to diagnose me, but is that video right? 2.103.12.92 (talk) 04:12, 28 March 2016 (UTC)

An internet video does not necessarily apply to your particular situation. If you're concerned, see your doctor. ←Baseball Bugs ^{What's up, Doc?} carrots→ 04:19, 28 March 2016 (UTC)

• Any question that asks about whether or not some health condition you have is normal requires a medical diagnosis. Such a thing should only be performed by a medical professional. See Wikipedia:Medical disclaimer. Wikipedia does have an article titled nasal congestion, but how that applies to your situation, we cannot say. --Jayron32 12:19, 28 March 2016 (UTC)

• I strongly disagree with that. Saying that humans normally have two arms, not three, is by no means a medical diagnosis. And neither is saying that both nostrils are normally open. Saying what specific medical condition the OP has or doesn't have, now that would be a medical diagnosis. StuRat (talk) 16:47, 28 March 2016 (UTC)

• You may find our article nasal cycle enlightening. SemanticMantis (talk) 13:49, 28 March 2016 (UTC)

And there was light. Thank you ;) --TMCk (talk) 16:45, 28 March 2016 (UTC)

Note that the article says "partial congestion", not "total blockage". StuRat (talk) 16:50, 28 March 2016 (UTC)

This is worth noting. The nasal cycle is merely a back-and-forth shift between the tumefaction of one nasal passage, resulting in disparate airflow nasal respiration, but if one closes off the presently "dominant" nostril, airflow through the other nostril is rarely restricted to a noticeable degree (as evidenced by the fact that many people go through life never recognizing the nasal cycle is a physiological reality in their respiration). However, what the OP seems to be referencing is outright blockage. The propensity of this blockage to switch may or may not be related to the nasal cycle, and I join the other editors here in urging that the OP consult a medical professional if this is a cause for concern. Snow ^{let's rap} 07:55, 1 April 2016 (UTC)

How many types of neuron cells do exist?

How many types of neuron cells do exist? I'm confused because According to the BRS gross anatomy (8th edition, p.6) there are three types (1. unipolar, also pseudo-unipolar. 2. bi-polar. 3. multi-polar) while according to the Moore anatomy book (7th edition. p.46) there are 2 types of neurons (multipolar and pseudounipolar) 93.126.95.68 (talk) 03:49, 28 March 2016 (UTC)

Neuron#Classification covers various types of neuron cells. The answer to the question "how many..." depends first on the answer to the questions "what constitutes a "type"..." which is not always a straightforward thing to answer, and over which many recognized experts will disagree. --Jayron32 12:17, 28 March 2016 (UTC)

There are hundreds of named types of neurons. One of the ongoing projects in modern neuroscience is to come up with a principled way of dividing neurons into types -- probably the ultimate answer will be based on gene expression patterns. Looie496 (talk) 14:03, 28 March 2016 (UTC)

There are as many different neurons as there are neuroscientists studying them. A slightly flippant answer, but not far of the truth. Nobody agrees. The terms you mention refer to gross morphology of the neurons, but there are many more kinds than just those you mention. Then, do you want to look at electrical properties? Neurotransmitters? (Many more of those than mentioned in the link provide above by Stu) Biochemical/genomic profiling? Anatomical location? Any of the above? You could make a case that each neuron is a different type, it just depends on how fine-grained you want to be. Conceptually similar to coastline paradox really. Fgf10 (talk) 23:01, 28 March 2016 (UTC)

Special relativity. Derivation of $t'$ formula

Question

Remark

According Null result of Michelson–Morley experiment extrapolation we can write: $BC'^{2}=CC'^{2}+BC^{2}$ ; $(ct_{to\ upper})^{2}=(ut_{to\ upper})^{2}+(ct_{self})^{2}$; $t_{self}^{2}=t_{to\ upper}^{2}{\tfrac {c^{2}-u^{2}}{c^{2}}}$; $t_{self}^{2}=t_{to\ upper}^{2}(1-u^{2}/c^{2})$; $t_{self}^{2}=t_{to\ upper}^{2}{\tfrac {(1-u^{2}/c^{2})^{2}}{1-u^{2}/c^{2}}}$; $t_{self}=t_{to\ upper}{\tfrac {1-u^{2}/c^{2}}{\sqrt {1-u^{2}/c^{2}}}}$; $t_{self}={\tfrac {t_{to\ upper}-t_{to\ upper}u\cdot u/c^{2}}{\sqrt {1-u^{2}/c^{2}}}}$; $x=t_{to\ upper}u\Rightarrow t_{self}={\tfrac {t_{to\ upper}-ux/c^{2}}{\sqrt {1-u^{2}/c^{2}}}}$. Is derivation correct? $t_{to\ upper}$ — time needed light spherical wave to reach upper mirror ( moving with speed $\mathbf {u}$) in point C' in Sun frame (observer on Sun, at rest). Sun frame is not rotating. $t_{self}$ — time needed light spherical wave to reach upper mirror in frame of interferometer , $t_{self}\sec <t_{to\ upper}\sec$. $t'$ — time seen in interferometer frame from Sun frame. $t$ — time seen in Sun frame. $t'=t_{self}$ as we can consider vertical arm of interferometer as primitive clock ticking when light is reflected. $t=t_{to\ upper}$ . $t'$ is slower than $t$ . Is it correct?

http://www.feynmanlectures.caltech.edu/I_15.html#Ch15-F2 , Fig. 15–2; https://en.wikipedia.org/w/index.php?title=Wikipedia:Reference_desk/Science&action=edit&oldid=711458491 Light path analysis and consequences https://en.wikipedia.org/w/index.php?title=Wikipedia:Reference_desk/Science&action=edit&oldid=711808143 Null result of Michelson–Morley experiment extrapolation

193.238.36.135 (talk) 09:24, 28 March 2016 (UTC)

I think it's correct. -- BenRG (talk) 23:23, 28 March 2016 (UTC)

biotin crosslinking with streptavidin

I'm on a commercial R&D team where most of my colleagues are skeptical of any experimental process that is too "academic" -- still, we really want to increase average** particle size after magnetic particles linked to streptavidin bind to protein-functionalized-biotin conjugates, which doesn't appear to be really affected by pH (we have to stay within pH 5 to 9), and gets worse (smaller) with increasing ionic strength. So currently we're running optimization experiments by changing the temperature of the buffer during the biotin-streptavidin binding process.

To me, the obvious thing to do would be to obtain "double biotin" -- a covalent linker with biotin on both ends. We would only have to dope at around 0.1 to 2% ratio (per equivalent of "mono" functionalized and free biotin we're using) to get controlled increases in particle size, so the cost increase would be marginal. When I look up "dual biotin" I keep getting double biotin that is attached to some sort of nucleotide, which is pointlessly expensive because we have no use for the nucleotide. What is the right keyword to get a double biotin linker that *doesn't* have any nucleotide in it? Basically, if I can find a double linker that's cheap enough, then I might persuade my team (always bottom-line-minded) to try my idea.

** I really think we should be using the median as a useful marker of particle size to account for outliers, based on my previous experience with population statistics, but my team still thinks the mean is just good but sigh

Yanping Nora Soong (talk) 16:50, 28 March 2016 (UTC)

Have you tried this Google search ?

"double biotin" "covalent linker" -nucleotide

Also, is the term "dual biotin" ever used ? StuRat (talk) 20:29, 28 March 2016 (UTC)

I don't really understand this: "dope at around 0.1 to 2% ratio (per equivalent of "mono" functionalized and free biotin we're using)" If you are reacting the protein with variable amounts of something with biotin that covalently binds to various random spots on the protein, then adding a bit more should be the same as using "double-headed biotin" ... shouldn't it? And if you have somehow engineered specific sites into the protein (which is at least possible) then you could engineer more with a similar effect. What am I missing here?

I'm assuming there are strept?avidin beads like this being bound to biotinylated protein with varying numbers of moieties attached. The way you describe the size of the complex makes me think you are trying to get multiple beads to bind per protein and multiple proteins per bead for big aggregates, though I didn't think this was necessary in routine protocols?

A concern I would have with double-headed biotin is that a) if the linker between the two biotins is really short, then I don't know how likely it would be for a free biotin chained to a huge (I assume) magnetic bead to be able to get access to another one, and b) if the linker is long, then I don't know if the two biotins can access multiple avidins bound to the same magnetic bead.

But the biggest worry I'd have would be bureaucratic. Using a different reagent to interact with the bead sounds like a patentable invention. Problem is, this is a fairly mature process - I would worry there could be some patent out already that would interfere with your product as revised. Also, telling us too much about your invention might interfere with patenting it in many jurisdictions... Wnt (talk) 22:14, 28 March 2016 (UTC)

• If I'm reading your question correctly, you want to bind multiple proteins to a single bead in this order: bead+streptavidin=biotinilated protein=double headed streptavidin=biotinilated protein etc? You're going to need a long flexible linker for that, otherwise the biotinilated sites on new proteins aren't going to be able to bind to the exposed streptavidin due to steric interactions. Undergrad organic chemistry is a long time ago, but the obvious candidate for that would be a long alkane. However, with those you're going to get significant problems with hydrophobicity of your linkers. Fgf10 (talk) 22:55, 28 March 2016 (UTC)

Nay, he said two biotins with some covalent linker. I had assumed this had to be linked to the protein somehow. Otherwise they would just aggregate the beads on their own with no protein needed (though maybe not as much? Or maybe what counts is how much protein gets pulled down regardless of how?) I would have thought that aggregating beads on their own in any quantity would cut the particle size rather than raise it, by creating more nuclei, though I suppose you could add it after the protein to try to get any wallflower beads to stick on to something. Still... this feels too complex, too finicky. If you want bigger complexes, couldn't you just use bigger beads? Wnt (talk) 14:08, 29 March 2016 (UTC)

Medicine price in the US: wholesale $5-7, monthly $100-$200

According to budesonide: "The wholesale price for an inhaler containing 200 doses is about 5 to 7 USD as of 2014.[11] As of 2015 the cost for a typical month of medication in the United States is 100 to 200 USD"

Where do the $95-$193 go to? Couldn't a lab just offer it for $9.5-$19.30? Wouldn't US resident who need this medicine for treating a chronicle condition be better off traveling abroad to buy it? --Llaanngg (talk) 23:34, 28 March 2016 (UTC)

Please provide a link to where it says that. Offhand, I'm thinking that they charge $5-7 for the inhaler, but you must pay additional for the meds it contains. StuRat (talk) 00:00, 29 March 2016 (UTC)

It is in the third paragraph of the linked article. You assumption is not right. It says one inhaler with 200 doses. That implies inhaler and medicine together. --Llaanngg (talk) 00:04, 29 March 2016 (UTC)

The source for the first sentence is available online, but the source for the 2nd line doesn't appear to be. This makes it difficult to know exactly what they said. StuRat (talk) 00:24, 29 March 2016 (UTC)

probably very misleading statements, at best....the fed govt via medicare/Medicaid has an upper limit on allowable markup (their formula for determining price is likely several thousand pages long...but that much markup would not be allowed)...private insurance negotiates price too, in an incredibly complicated and opaque manner as well....the "retail" price might be the price that very, very few people actually pay (ie no insurance, not on medicare/Medicaid) and this price varies from region to region, drug store to drug store...point is, these claims in the Wikipedia article are largely meaningless...68.48.241.158 (talk) 00:15, 29 March 2016 (UTC)

My guess is that there is a confusion between inhaled budesonide and oral budesonide. The oral tablets are used differently than the inhaled treatments and typically contain 10-20 times higher doses, which could explain a much higher cost if the second price is actually referring to the oral treatments. Dragons flight (talk) 00:18, 29 March 2016 (UTC)

In answer to the laterlast question, while this isn't legal advice the answer is "probably not" even if the stated costs were accurate. See this page for the FDA's guidance on importation [1]. Note that the general guideline is 3 months. While this isn't a limit, consider the wording on when more than 3 months may be allowed. Also the fact the guidelines aren't intended for cases when a person is importing drugs available in the US which are cheaper elsewhere (except where the patient needed to fill the prescription while overseas) anyway.

So while again this isn't legal advice, if you're lucky you may be allowed to import 3 months when coming back. Perhaps you'll even be allowed to import 3 months every 3 months. Even with usage 2 times a day, this will probably only be a single inhaler. If you need more than 2 doses a day, perhaps you'll get away with 2. So at most perhaps you're saying around $380. More likely $190.

If you live right next to the Canadian or Mexican border (and Mexican may bring additional safety concerns) perhaps it'll be worth the cost including your time spent (maybe a passport if you wouldn't have one otherwise). If you live far and need to either drive long distance or fly, it's unlikely to be worth it. And you have to hope you'd really be allowed to do it regularly, particularly if you were only gone for an hour or two. Even more so if you're trying to import 2 regardless of whether you use enough for this to be 3 months supply.

Nil Einne (talk) 03:37, 29 March 2016 (UTC)

Pharmaceuticals are subject to all kinds of absurd patent, exclusivity, and just plain ridiculous regulation. From what I've, heard, the American locations (with foreign owners) that make them are shrines of bureaucracy, where it costs them $5,000 to go over their records if somebody scribbles out a number, and they fire a whole shift if someone draws a smiley face on a box. (So to make things extra secure, they hire almost entirely immigrants and work them long hours on swing shifts) So their costs are "actually" higher than the costs for people quoting drug prices FOB Nairobi, as in the first source listed. That said, drug imports to the U.S. can be around 55% cheaper, according to this WebMD article, which definitely makes mail order "against" the law sound very mainstream indeed. There's an online pharmacy article here. However, note that the TPP and its fellow international overlords are expected to lay waste to health care everywhere, leaving Canada and Mexico in the same sorry boat as Americans - see [2] [USER WAS BOMBED FOR THAT POST, some say] Wnt (talk) 13:13, 29 March 2016 (UTC)