Wikipedia:Reference desk/Archives/Science/2018 August 28

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August 28

Nomenclature for Vitellaria paradoxa

My questions in the first section of Talk:Vitellaria, about how the shea tree came by its different scientific names, have been unanswered for a little while which means in my experience they may go unanswered for years. If anyone here can point me to where I might be able to research the story (out of a rural home, with the Internet as my research library) I will try to find it out myself, or I'll be delighted if someone can add to the discussion on that Talk page. - Egmonster (talk) 01:56, 28 August 2018 (UTC)

A copy of my answer on the article talk page - "The book "100 Top Food Plants" has some information on the naming see page 474. According to that, Vitellaria derives from vitellus (yolk in latin) and aria meaning 'like', a reference to the valuable kernel, and the paradoxa specific name (meaning strange or contrary to expectation) is from its ability to grow in extremely dry regions. The Hall 1996 monograph probably goes into a lot more detail." Mikenorton (talk) 08:40, 28 August 2018 (UTC)

Thank you very much, Mikenorton. Now I have some reading to do! It would be nice if I could understand that timeline. - Egmonster (talk) 16:20, 28 August 2018 (UTC)

Cations and HDPE

do cations adsorb to plastics (Ca2+, Na+, K+), possibly reducing the concentrations of cations in a water sample? — Preceding unsigned comment added by 184.167.211.134 (talk) 03:54, 28 August 2018 (UTC)

For most plastics no, but you may be interested n ion exchange resin. Most plastics with a hydrocarbon backbone (polythene, HDPE polypropylene) do not interact with metal ions in solution, and the ions will prefer the company of water. Graeme Bartlett (talk) 22:11, 28 August 2018 (UTC)

But plastics does take up a considerable amount of water, since its actually a highly porous material on the molecular scale. You can test that with Red beet or Tomato sauce which both will start to taint the plastic in "color" after some hours unless it is colored itself enough to overshadow any "contamination". --Kharon (talk) 23:36, 30 August 2018 (UTC)

I'd say that has more to do with hydrophobic pigments like carotene associating with the plastic rather than water itself, which is obviously repelled by the hydrocarbon backbone of essentially all synthetic polymers. 202.155.85.18 (talk) 03:14, 4 September 2018 (UTC)

Autonomic block

Pharmacology: When a first generation H1 blocker like Diphenhydramine causes as a side effect an "autonomic block" what does that exactly (Which functions of the body are impaired) mean? --2003:C3:EF0F:CF43:9D84:42D3:4E4A:2A20 (talk) 09:18, 28 August 2018 (UTC)

Read autonomic nervous system. Graeme Bartlett (talk) 22:14, 28 August 2018 (UTC)

More specifically: first-generation H-1 antagonists tend to be "dirty" and have, in addition to their desired antihistamine effect, activity at other receptors, which can produce side effects. --47.146.63.87 (talk) 07:04, 29 August 2018 (UTC)

minnesota starvation experiment

the minnesota starvation experiment mentions people eating 10,000 calories a day. what causes that extreme hunger and how does the body know when they have eaten enough?

See Hunger (motivational state). And the correct number is 1,560 kilocalories per day. --Guy Macon (talk) 15:42, 28 August 2018 (UTC)

The OP may be confused by the difference between a calory with a small "c" (also known as a small calory or gram calory) and a Calory with a capital "C" (aka a large calory, food calory or kilocalory). The latter is equal to 1000 of the former, and is usually the unit discussed in dietary contexts, but many non-scientific writers are careless about defining their terms and/or about using the capital.

1,560 kilocalories, equal to 1,560,000 small/gram calories, is a fairly frugal daily diet. 10,000 (small) calories is equal to 10 large/food/kilocalaries and is equivalent to about one tenth of a slice of bread. {The poster formerly known as 87.81.230.195} 90.208.127.181 (talk) 16:19, 28 August 2018 (UTC)

I'm not sure what this discussion about kilocalories means. I was reading the book "The Great Starvation Experiment" which is about the minnesota starvation experiment. In chapter 10 it says; "They each consumed on average 5,219 calories per day. Most commented that even when they were stuffed to the point that they couldn’t eat any more, they still felt hungry. There was a seldom-verbalized irrational fear among them that food might be again taken away. Periodic uncontrolled gorging was common. The doctors noted with awe that Richard Mundy, on one Saturday in November, managed to consume 11,500 calories." I just wanted to know what bodily process causes such hunger in a person. The book doesn't say. Thanks 77.101.141.178 (talk) 18:34, 28 August 2018 (UTC)

• Ancel Keys involvement means the results can't be trusted. Abductive (reasoning) 18:57, 28 August 2018 (UTC)

OK.

Resolved

I don't know what "resolved" means: the original question states something not true (our article never mentions people eating 10,000 or more calories a day) and the book The Great Starvation Experiment was not written by A. Keys, so his credibility is here irrelevant. What about the credibility of Todd Tucker? 194.174.76.21 (talk) 12:06, 29 August 2018 (UTC) Marco Pagliero Berlin

I think the question is just poorly worded. From the OP's later clarification, I don't think the OP intended to suggest our article says people ate 10000 calories a day. Rather they are claiming as part of the experiment, people ate 10k calories a day. It seems to me there are two main issues here. One is whether the claim made in the book is an accurate reflection of what happened and whether the OP misunderstood what was being said or something else. For this, the credibility of Ancel Keys is irrelevant.

The second is whether the experiment is so poorly conducted that any results are questionable. For that, the credibility of Ancel Keys may be relevant. (Note that I am not saying I agree with the view that anything Keys was involved in, no matter what the level of involvement and the level of involvement and calibre of other researchers, is questionable. Simply that Keys may be relevant.)

There is to some extent a cross over, namely where did the author get the information? It is unlikely the author was directly involved in the experiment. The author is a historian who interviewed survivors and Keys [1]. It seems easily possible that the specific anecdote the OP is referring to came from Keys without verification from other sources. It seems reasonable that someone may believe an author is reasonably credible, but they were wrong to trust a specific source.

In other words, if you really think Ancel Keys will just make stuff up or something like that, you may reject information coming solely from him despite it being reported by someone generally credible. (Note that again, I am not saying that I agree with such a view on Ancel Keys, simply that there are reasons why the credibility of Ancel Keys may matter even if he didn't write the book in question.)

Nil Einne (talk) 17:47, 29 August 2018 (UTC)

Thank you, Nil Einne - you've created a pretty well-stated explanation of the issues at hand. I would like to add some ancillary commentary, because this question has touched off some really profound questions about reliability of information that are especially relevant in today's mixed-up world of user-generated-truth.

The field of historiography encompasses the academic methodology that is widely used to understand historical fact by evaluating current- and historical- reference material. It is not, in general, easy to know whether a source is "reliable" - and this difficult task is made more troublesome when the source material is very old. But this is exactly why professional historians train and study and peer-review each other's work!

Our role, here at the reference desk, isn't really to provide the answer to the questions that come up - our objective is to provide good-quality, encyclopedic reference material, so that the originator can inform themselves about the topic. It would be out-of-scope for us to pretend that we can definitively answer most of these types of questions. But what we can do is to point the reader at a bunch of reputable resources - often beginning at our own articles.

Now - in this case, somebody has made a claim - broadly - that one or more of the reference materials might be unreliable. That claim in itself may also be unreliable! So, you see the conundrum that we have!

But to reiterate - our role at the reference desk is not strictly to answer the question concretely - we are only here to provide pointers to more information. The onus is on the interested reader to go out and read those resources, and decide for themselves whether each resource is accurate and truthful and factual; and to determine whether that estimation has changed over the decades during which other informed readers have reviewed the same material; and to connect with the small-but-very-dedicated community of people who know more about these topics than we, the general-purpose volunteers at Wikipedia's reference desk.

What we should have done - at the very onset of this question - was to provide a good link to a few resources: a quick link to the reference section in our article - which already refers to the primary source material, as well as numerous secondary sources. We should not actually have tried to answer the question - we should have provided links to various reliable sources where the answer can be found. This is what constitutes scholarship, as opposed to dumb-internet-search-querying, and it is important to indoctrinate these ideas into both our OP and to the volunteers who help out at the reference desk.

If the original investigator actually cares about the answer, they need to read those resources. That is where they'll get the context to inform the question and its answer - and without that context, any answer we provide would be unsuitably hollow.

Nimur (talk) 17:28, 1 September 2018 (UTC)