Wikipedia:Reference desk/Archives/Science/2017 October 28

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October 28

How many N-receptors are there (2 or 3?)

I was reading different sources about the number of the N-receptors (nicutinic receptors) among the cholinergic receptors. The most of the sources say that there are 2 nicutinic receptors (N1 and N2) but other source says there are 3 nicutinc receptors: "Nicotinic receptors are found in the CNS, in autonomic ganglia, and in striated muscle. They are divided into N1, N2, N3-cholinoreceptors. N1 - and N2 -cholinoreceptors are localized in the CNS, N1 -cholinoreceptors – in ganglia, N2 -cholinoreceptors – in muscular synapses, N3-cholinoreceptors – in the adrenal glands. The mechanism of nicotinic action has been clearly defined." Is that correct?--212.90.60.81 (talk) 04:08, 28 October 2017 (UTC)

We have a detailed article about Nicotinic receptors (note spelling). It categorizes them into two major groups based on location—muscular vs neuronal—and then further into ganglion-type and CNS-type of neuronal. It not mention a type specific to adrenal-gland location and does not use N1/N2/N3 terminology at all. Could you cite the source you are quoting so we can see context and if it cites other refs for us to read? DMacks (talk) 04:25, 28 October 2017 (UTC)

• If you want other sources than our article, see "Mammalian Nicotinic Acetylcholine Receptors: From Structure to Function", most recent review I could find in two minutes on PubMed. Look at tables 1 and 2. Fgf10 (talk) 10:30, 28 October 2017 (UTC)

Physical exertion causing rheumatism

This comes from the 19th-century book that I referenced in the toothache question of Wikipedia:Reference desk/Archives/Science/2017 October 8. I've got someone born in 1811 who moved to Iowa in 1851 and lived there until his 1880 death, and about him it's said:

The exposure which he was required to endure in a new country and among scattered societies, caused inflammatory rheumatism, which completely wrecked his physical frame, and the last ten years of his life were spent in intense bodily suffering.

Can the environment or physical exertion cause rheumatism of any sort? Apparently it can't cause rheumatoid arthritis, since Rheumatoid arthritis#Risk factors for this autoimmune disease are all irrelevant for a preacher in 19th-century Iowa who rejected drinking and smoking as sinful. I'm guessing that our Iowa friend got some sort of illness along the way (per the first sentences of Rheumatism#Types), or that he had an autoimmune disease that simply started after he moved. Is this a reasonable conclusion? Nyttend (talk) 13:16, 28 October 2017 (UTC)

I think the article rheumatism is pretty clear -- it's a generic term for pain. Serious physical exertion might cause osteoarthritis, either directly or as the result of physical injury to the joints. Damage to the sacroiliac joint or to the spine itself might cause sciatica or related conditions. There are a lot of options and I certainly can't diagnose a sentence (and am not qualified to diagnose a patient either). But going from rheumatism to rheumatoid arthritis specifically seems like a vulgar error. Wnt (talk) 15:19, 28 October 2017 (UTC)

Without knowing where this unfortunate person was and the nature of the terrain, it's impossible to even guess. It's possible it might have been what we now know as Lyme disease. When I received the diagnosis of RA, I was told that there are hundreds of conditions that all get lumped together as "rheumatoid arthritis" for ease of discussion. What might shed light on whether it was rheumatoid arthritis is a trace of his descendants and looking at their medical history, to see if any of them had rheumatoid arthritis or not. (OR here, well it's not my research but... I am currently taking part in a clinical trial to establish the degree of hereditability of RA, and as part of that, I have found this horrible disease seems to have affected at least 4 out of the past 6 generations of my family, up to and including myself.) --TammyMoet (talk) 10:42, 29 October 2017 (UTC)

Time for Wow signal to reach Earth

Assuming it was genuine, approximately how many years it took for Wow signal to reach the Earth? If there's an RS, one might want to add it to the article. Thanks--212.180.235.46 (talk) 17:44, 28 October 2017 (UTC)

Depends on which star it (might have) come from. The article on Wow says that the closest easily visible star in the direction of Wow is Tau Sagittarii. The article on that star says that it is 122 light years away. But that is just a possible answer to your question,!of course. Attic Salt (talk) 17:54, 28 October 2017 (UTC)

And, in case it's not obvious, it would take a signal 122 light-years away 122 years to reach us, at the speed of light. StuRat (talk) 16:02, 29 October 2017 (UTC)

Part of the problem and mystery of the Wow signal is that the receiver wasn't really pointing at any nearby stars when the signal came in. Tau Sagittarius is the closest easily visible star to where the signal came from, but that means "closest" from our perspective. Closest if the heavens were a flat image.

If you look at the map on the Wow signal article, it came from one of the two red ovals on the star chart. (It was received by a pair of receivers, but the way they filtered the signal means they don't know which of the two receivers actually picked up the signal.) The red ovals are a bit to the north-west of Tau S.

If the signal really is extra-terrestrial and our data about it is correct, then either it came from a transmitter in deep space (a starship?) or it came from a star system incredibly far away. Much farther than Tau S. ApLundell (talk) 15:52, 30 October 2017 (UTC)