Wikipedia:Reference desk/Archives/Science/2018 July 13

Science desk
< July 12	<< Jun | July | Aug >>	July 14 >

Welcome to the Wikipedia Science Reference Desk Archives
The page you are currently viewing is an archive page. While you can leave answers for any questions shown below, please ask new questions on one of the current reference desk pages.

July 13

Millipede legs; restriction on total number

Centipedes always have an odd number of pairs of legs, meaning that their number of legs is always divisible by 2 but not by 4. But is there any restriction on how many legs a millipede can have?? Georgia guy (talk) 00:49, 13 July 2018 (UTC)

This article,[1] among others, says millipedes have four legs per segment. ←Baseball Bugs ^{What's up, Doc?} carrots→ 01:18, 13 July 2018 (UTC)

Which means that millipedes could never have the same number of legs as centipedes. --Jayron32 00:16, 14 July 2018 (UTC)

One Internet site talks about 394 as a common number of legs; another says that millipedes always have an even number of pairs (meaning a number that is divisible by 4.) These 2 sources clearly contradict each other. Georgia guy (talk) 00:22, 14 July 2018 (UTC)

Sometimes a source won't have a leg to stand on. ←Baseball Bugs ^{What's up, Doc?} carrots→ 00:33, 14 July 2018 (UTC)

Encyclopedia of the Animal World, Elsevier 1972, calls the segments "rings" and says that most rings have 2 pairs of legs, while the first few rings only have 1 pair of legs. So it looks like the number of millipede legs could be divisible by four or two, depending on whether the number of segments with 1 pair of legs is even or odd.--Wikimedes (talk) 16:46, 14 July 2018 (UTC)

Discounting "common species have between 34 and 400 legs" in our millipede article, I haven't found a specific example of a millipede with the number of legs divisible by 4. From the 2nd paragraph of Millipede#Body: "The second, third, and fourth body segments bear a single pair of legs each and are known as "haplosegments"", which would indicate that the number of legs is never divisible by four. This [2] site says there are "often 3" haplosegments.--Wikimedes (talk) 17:18, 14 July 2018 (UTC)

And again I know nothing about birds

cheep cheep

So, saw these little guys while boating. Didn’t see any larger birds that looked like adults of the same species. This was right on the waterline of a small island in a freshwater lake in the Kenai National Wildlife Refuge. They certainly acted like chicks, making little “cheep cheep” noises, staying right on the apparent nesting site, making no attempt to fly or swim. Anyone know what they might be? Beeblebrox (talk) 02:30, 13 July 2018 (UTC)

I certainly know nothing about birds too, but they look a bit like greater sage-grouse chicks to me. Alex Shih (talk) 02:46, 13 July 2018 (UTC)

Here is a website for Alaskan birds. Of course it is a big state with lots of avians so it might take some searching. To my untrained eye this is a bit like your pic - especially if you allow for variation in coloring for young chicks. I could be way off though. MarnetteD|Talk 04:30, 13 July 2018 (UTC)

Rats I missed where it stated that the turnstone is a coastal bird. Good luck in tracking it down. MarnetteD|Talk 04:33, 13 July 2018 (UTC)

The beaks are too substantial for turnstones, they're probably some kind of young gulls, which are notoriously hard to identify. Acroterion (talk) 00:36, 14 July 2018 (UTC)

The fact that this is a freshwater lake may narrow the field. I’m beginning to think they are maybe Arctic Terns. Most images I can find show a orangish-yellow beak, but some of juveniles show a duller beak as these have. Beeblebrox (talk) 17:19, 15 July 2018 (UTC)

Vitamin B11

I can't find the chemical formula for Vitamin B11 (pteryl-hepta-glutamic acid). Can you help? 121.44.187.6 (talk) 03:57, 13 July 2018 (UTC)

There isn't one in this list B vitamins#List of B vitamins. Hopefully someone else can help. MarnetteD|Talk 04:22, 13 July 2018 (UTC)

A google search bring up this. MarnetteD|Talk 04:24, 13 July 2018 (UTC)

BTW, although it's one of the few to be unsourced I'm fairly sure our article is right. There's no longer such a thing as a recognised Vitamin B11 in humans. Any source which still calls pteryl-hepta-glutamic acid (or PHGA or chick growth factor) as a human vitamin B11, or which says there is such a thing as a human vitamin B11, is either outdated or unreliable. Or maybe both. If someone is trying to sell you something with vitamin B11 for human consumption, run away. Nil Einne (talk) 08:46, 13 July 2018 (UTC) 09:53, 13 July 2018 (UTC)

This is the original poster. I am well aware it has no value for humans. It happens that I am in a family of chicken ranchers. 121.44.187.228 (talk) 08:53, 13 July 2018 (UTC)

This one was a head-scratcher. The problem is that references to Vitamin B11 basically end in the 1950s as far as the scientific literature goes (though the papers that studied it continue to be cited later). Many of the papers on the subject are behind paywalls even my library can't get past, and those that I can read predate the chemical identification of the molecule. The first clue I had that something was wayyy off was seeing articles much much later that cited these B11 papers while discussing folic acid! Indeed, NCBI's pubchem lists "vitamin B11" as one of the 200+ synonyms for folic acid[3]. Unfortunately, it's specifically listed in vendor synonyms. Which means, at some ponit, somewhere, folic acid has been sold as B11. Which does not mean that scientists consider it the same. Anyway, what I conclude, but can't be 100% sure of, is that it was identified as an essential vitamin for chicks, and later found to be a known compound, and the name was never used again. Someguy1221 (talk) 10:32, 13 July 2018 (UTC)

I did discover that some naturopaths & homeopaths sell what they call "Vitamin B11" as folate. What they are actually selling could be anything - particularly homeopaths, homeopathy being essentially 100% quackery, and B11 being useless for humans as noted. Can any nice chemist tell me how to arrive at a formula for pteryl-hepta-glutamic acid? OP 121.44.185.44 (talk) 13:55, 13 July 2018 (UTC)

It does apear to be a folate derivative. Here's a ref (I don't have time to chase the cited refs right now): doi:10.1021/jo00837a600. DMacks (talk) 14:15, 13 July 2018 (UTC)

Here's another one. Ok, so part of the problem was that it's actually pteroylhepta-γ-L-glutamic acid. Also explains the history. When people started purifying folic acid and identifying its chemical structure around the 1940s, it was found that there were many forms, some of which only differed in the length of the glutamate chain (as a name of a chemical rather than a class of chemicals, "folic acid" only has one glutamate). It was further found that the length of the glutamate chain affected the molecules bioavailability in a species-specific manner. That's it. That's all, nothing else magical or special. Different organisms like to get their folate while it's attached to different things. Someguy1221 (talk) 00:09, 14 July 2018 (UTC)

The article you found gave me exactly what I needed. Many thanks for your help. OP 118.209.58.129 (talk) 13:49, 16 July 2018 (UTC)