Wikipedia:Reference desk/Archives/Science/2016 December 30

From Wikipedia, the free encyclopedia
Science desk
< December 29 << Nov | December | Jan >> December 31 >
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.


December 30[edit]

What if we discovered a new (caloric) macronutrient?[edit]

What would happen to the fields of nutrition and medicine if we were to discover a new calorie-containing macronutrient? Suppose, for instance, the body could oxidize iron (Iron can be oxidized; that's why we have that reddish substance called rust) and use it as a major or sole energy source without risk of toxicity. If the body could do this, wouldn't it eliminate (or at least reduce dramatically) the need for glucose assimilation and insulin production, ending diabetes forever? I have also read that the triglycerides circulating the bloodstream are there to supply energy. If the body could use an inorganic substrate in place of triglycerides, would that reduce the risk of heart disease? I started wondering about this after I heard about chemolithotrophy in bacteria.98.18.19.22 (talk) 03:28, 30 December 2016 (UTC)[reply]

You're asking for speculation. That's not what the Reference Desk is for. --69.159.60.210 (talk) 04:52, 30 December 2016 (UTC)[reply]
The idea of a novel calorie source is not implausible at all, but the idea of one that meets all our energy needs without any "toxicity" is highly implausible. The basic issue is that if a given amount of the substance causes the body's energy-consuming systems to be activated to just the right degree, then it is very likely that a higher amount will cause the systems to be hyperactivated. The only solution is to have mechanisms for regulating the amount of the substance in circulation, just as we do for glucose, triglycerides, and other calorie sources. Looie496 (talk) 04:56, 30 December 2016 (UTC)[reply]
To talk about eliminating diabetes and heart disease by switching to a new calorie source is like talking about fixing a problem with your car stalling out by switching it to a diesel. Only in this case, you have to invent and build the first diesel engine from scratch. This is not easy. FWIW, my favorite zombie theory involves running nano wires directly from some mechanical digestion process to each mitochondrion to power the proton gradient directly, thereby reducing any need for respiration and circulation, at least if you're willing to tolerate some ... degradation in performance since biosynthetic precursors would become increasingly scarce. Wnt (talk) 12:51, 30 December 2016 (UTC)[reply]
The OP's question is framed in a far-fetched way, but arguably, what he is looking for exists. See Ketone bodies and (nutritional) Ketosis. One might note that two related and roughly simultaneous changes in dietary recommendations in the US: for lower fats (and thus usually higher carbohydrates) for the general population and second, greater insouciance about carbohydrate intake for diabetics (recommendations about carbohydrate limits, and thus standard insulin prescriptions have increased over the decades). .... have not been crowned with success and glory.John Z (talk) 03:30, 4 January 2017 (UTC)[reply]

Under which classification is "troponin"?[edit]

If CPK is under classification of enzymes, then under which classification is troponin? (We can not simply call it proteins because enzymes are also proteins) 93.126.88.30 (talk) 12:46, 30 December 2016 (UTC)[reply]

First let's link Creatine phosphokinase and troponin, while I try to understand what you're asking... hmmm, to begin with, as our article reminds me (would I forget something like that? :) troponin is a complex of three regulatory proteins. Enzymes are also generally, probably always proteins (I think calling a ribozyme an enzyme would get you dirty looks). Does this cover it? Wnt (talk) 12:52, 30 December 2016 (UTC)[reply]
I should probably add that categories like enzyme, regulatory protein, and structural protein are by no means absolute. It is a very common story for someone to find out that a protein known for one of these purposes actually has another - cytochrome c, crystallins, beta-catenin come to mind. Since the functions of most proteins aren't really known at all, we can imagine that the list of known functions for existing proteins might be similarly inadequate. Wnt (talk) 13:02, 30 December 2016 (UTC)[reply]
But for now, we know that troponin is not enzyme. Isn't it? By the way, I didn't find an article about "regulatory proteins" even not under protein classification I didn't find reference about it. — Preceding unsigned comment added by 93.126.88.30 (talk) 13:17, 30 December 2016 (UTC)[reply]
True, the redirect above leads to something that isn't very explicit, to say the least. Regulatory proteins include anything like a transcription factor that acts by sticking on to something without altering its covalent chemical structure, but causing a change in what happens because it is stuck on. It is also true that it is hard to imagine an undiscovered enzymatic activity in most troponins, as they tend to be small, with much of their sequences accounted for (see [1] for example) with a lot of acidic and basic amino acids in the remaining areas that when present in large numbers, tend to jiggle around in water (because hydrogen bonds) in a way that doesn't allow for the usual sort of controlled "lock and key" catalytic fit to a substrate. I won't say impossible because I haven't looked at every last troponin gene or splice product (some might be bigger, I don't know) and because there isn't actually a hard lower limit on catalytic domain size or a solidly reliable rule on what they have to look like. But as a matter of presumption, no. Wnt (talk) 15:04, 30 December 2016 (UTC)[reply]

Species of Loligo used in the landmark studies of membrane biophysics[edit]

Hi, the giant axon of which species of Loligo was actually used in the landmark studies of membrane physics by Hodgkin, Huxley, and Katz? Loligo vulgaris, Loligo forbesii, or Loligo pealeii? I'm slightly confused because the 1949 article by Hodgkin and Katz mentions forbesii,[2] but other literature (e.g. [3]) mentions that the Nobel Prize to Hodgkin and Huxley was awarded for research done on pealei. Was it that both species were used? If so, when and why did they replace forbesii for pealei? --Eleassar my talk 12:55, 30 December 2016 (UTC)[reply]

I ran across [4] from 1945 which says forbesi (one i, for whatever reason). Wnt (talk) 13:08, 30 December 2016 (UTC). Sounds like [5] they switched to pealii when they moved to Woods Hole, which if I remember from the last source might have had something to do with Germans bombing their lab at Plymouth. Wnt (talk) 13:11, 30 December 2016 (UTC)[reply]
Thank you; seems credible. --Eleassar my talk 14:38, 30 December 2016 (UTC)[reply]

What is the effect of tissue hypoxia on the cellular metabolic rate?[edit]

Atmospheric hypoxia does not reduce the metabolic rate in adult humans (although it does in infants). The body is able to increase its oxygen uptake (by increasing oxygen extraction) so that oxygen consumption is not dependent on oxygen delivery. However, oxygen levels can become so low that increasing oxygen extraction does not provide adequate oxygen to maintain oxygen consumption; this process results in tissue hypoxia. It sounds as though tissue hypoxia would reduce oxygen consumption and therefore metabolic rate, but I also read that anaerobic respiration is increased, and this inefficient form of respiration is energetically expensive.98.18.17.127 (talk) 15:20, 30 December 2016 (UTC)[reply]

Climate Change[edit]

IIRC, a 2-3 years ago, a group of legitimate scientists who were were climate change skeptics examined climate change and changed their minds about climate change. Can anyone please point me to this study/group? It wasn't major news at the time but it did get attention of the news at the time. I want to say that they were Americans, but my memory could be mistaken. A Quest For Knowledge (talk) 15:35, 30 December 2016 (UTC)[reply]

I don't know about a group of 2 or 3, but an example that comes immediately to mind is Richard A. Muller. Shock Brigade Harvester Boris (talk) 15:39, 30 December 2016 (UTC)[reply]
My ears are burning a little. I would strongly suspect that AQFK is thinking of Berkeley Earth and Richard Muller, though I think Rich was the only prominent "skeptic" in the group. The original study was a bit more than 3 years ago though. We did get a variety of news coverage at the time, e.g. [6]. The narrative of the "converted skeptic" was very powerful, though I think Rich would tell you that the history of his views on climate change were more complicated than simple labels generally allow for. Dragons flight (talk) 22:45, 30 December 2016 (UTC)[reply]
Exxon seems to have changed it's position twice, first from warning about climate change, then to denying that climate change occurs as a result of human activity, to now publicly admitting it, and claiming they are working to prevent it, while actually working to undermine any attempts to limit fossil fuel use. StuRat (talk) 18:21, 30 December 2016 (UTC)[reply]
Five claims without a single reference; maybe a personal new record. Akld guy (talk) 19:52, 30 December 2016 (UTC)[reply]
[citation needed]? In the spirit of full disclosure, I read extensively about ExxonMobil as it impacts my finances and financial decision-making. I read their quarterly reports, their annual reports, and a lot of their scientific publications, including research both directly- and indirectly- financed by their corporation. The company cares about clarifying factual details with quantitative data via many publications, and they also produce an excellent app outlining their positions on many important issues, including ecology and climate. You can find these freely-available resources and read the investor information documents:
Now, I've been reading these resources for a long time; and I'm not going to pretend that the oil and energy industries are absolved of all guilt in all climate and environmental issues. Exxon, in particular, bore great corporate responsibility for the Exxon Valdez oil spill many years ago.
But StuRat has levied a strong and specific claim that ExxonMobil Corporation has denied the existence of climate change. [citation needed]. StuRat: in which public statement was that position outlined? If you cannot attribute that statement, you ought to rescind it, and you also ought to reconsider where you obtain your information. There is no shortage of excellent primary-source information on the role that energy production corporations play in complex environmental issues. Repeating an unsourced and vague accusation is hardly scientific: and if you're doing so while accusing the energy industry of taking an unscientific approach, you're committing a bit of hypocrisy. You allege subterfuge and deception but you cite no data or reference.
Large energy corporations are heavily scrutinized by regulators, journalists, and scientists. Energy companies and their decisions are driven by quantitative fact. ExxonMobil makes this clear: At ExxonMobil, we believe the risks of climate change are real. For more information on their official policy position on this complex issue, see the links they provide.
It is easy to levy vague attacks against "vile evil corporations." This is intellectually lazy, however.
For example, did you know that the largest renewable energy company in the United States is BP, a corporation that is nominally an "oil and gas" supermajor? When we, as scientists, scrutinize actual factual data, it casts a lot of new light on the thin narratives that we frequently hear. I leave it to you to decide the details for yourself: what motivates an evil, vile, energy corporation to become the largest renewable energy provider in the nation? Is it scientific denialism? Financial engineering to take advantage of renewable energy tax credit? Naive optimism about new alternative energy technologies? Or is wind energy actually a useful energy source in certain scenarios when its application is actually validated by sound scientific and engineering analysis?
Nimur (talk) 20:16, 30 December 2016 (UTC)[reply]
Our own ExxonMobil climate change controversy has plenty of good sources. Exxon may have been playing both sides, but they have been a major contributor to climate change denial. --Stephan Schulz (talk) 20:58, 30 December 2016 (UTC)[reply]
There is a great deal of important difference between opposing a particular regulatory policy and denying a scientific finding. For example, as discussed in March 2016 on the Perspectives blog, "ExxonMobil spoke out against the Kyoto Protocol in the 1990s because, among other things, it would have exempted two-thirds of the world’s emitters. And (ExxonMobil) opposed ill-conceived cap-and-trade programs in the 2000s, some of which would have exempted coal."
These positions are fundamentally different than "denying climate change."
I would go so far as to lay the charge that you, and many others, are committing the logical fallacy of false equivalence. Scientists, including scientists funded by ExxonMobil, may simultaneously believe that climate change exists; that anthropogenic effects are real; that fossil fuels contribute to environmental damage; and at the same time, believe that a specific regulatory action would be unsound, unsuitable, or otherwise ineffective.
If you say ExxonMobil denies climate change simply because they disagree with your favored tax scheme, you aren't making a scientific statement: you're making a statement of policy position. It isn't fair, nor is it an argument on sound logical footing, to imply that their different opinion on regulation amounts to "climate change denialism."
Once again, I ask for a simple reference - and one that would be ostensibly easy-to-find, if it hypothetically exists, to back your statements. In which publication did a legitimate representative with authority to speak on behalf of the ExxonMobil corporation ever deny the existence of climate change?
Nimur (talk) 02:48, 31 December 2016 (UTC)[reply]
To be scrupulously fair to StuRat and Stephan Schulz, they referred to Exxon, which existed (as the Exxon Corporation) between 1972 and 1998, not ExxonMobil which existed from 1998, so we need to consider possible statements made by/for the former, between 18 and 45 years ago, rather than the latter. [Disclosure: I used to work for Exxon Chemical back in the day.] {The poster formerly known as 87.81.230.195} 2.122.62.241 (talk) 03:06, 31 December 2016 (UTC)[reply]
(ec) I don't think we are exactly on the same wavelength here. Yes, I agree that acknowledging climate change and the mechanisms behind it on the one hand and supporting a particular policy with respect to it on the other hand are two different things, and that honest people can agree on one and disagree on the other. But that is not how, in practice, the debate is happening. Exxon has been funding, for a long time and with huge amounts, people and organisations that did argue against the reality of AGW with the more or less obvious goal to avoid regulatory consequences. They try to milk their existing revenue model for what its worth without significant concern for the environmental consequences while at the same time positioning themselves for the inevitable change of policy in the future - something BP has done slightly more successfully. Again, I point you to our article and the sources therein. Of course, if you don't want to accept that Exxon has, through words and deeds, denied the reality of AGW you can probably wiggle out of it by invoking some of your above lists of qualifiers ("well, yes, they have funded Heartland, and Heartland has denied climate change, but there is no link between these two points, and Heartland is not officially speaking on behalf of Exxon" - but if you repeat that over and over again with the different front organisations, it becomes a really thin argument). Wether a public spokesperson for Exxon says "there is no climate change" is about as relevant as wether Donald Rumsfeld says "Yes, waterboarding is torture, and we do do it". ---Stephan Schulz (talk) 03:12, 31 December 2016 (UTC)[reply]
Stephan Schulz, thank you for your insight. I respect your point of view. I am not particularly familiar with Heartland, and if you would kindly point me to further reading, I would be glad to further inform myself. At the same time, it is worth pointing out that large corporations expend lots of money to finance lots of third parties. Funding a group does not automatically imply endorsement of every one of that group's viewpoints. In the same way that I hope to read more to inform myself about the point of view you raise, I hope you might take an unbiased look at the plethora of work funded by this and other energy conglomerates. There is some merit to your speculation - but as a counterpoint, have you considered that there is merit to pluralism - in other words, deliberately seeking out groups who hold divergent views - even if we believe or know their views are wrong - because it is important to understand people who disagree with us? Your premise is that you have found a few examples of some groups funded by the company who hold some perspective that is unpalatable. Might it be worth evaluating whether the majority of groups funded by the company hold such a view? Suppose I concede that a few million dollars were spent to fund absoutely unscientific endeavors - but in counterpoint, hundreds of millions of dollars were donated to science and math education. Does this proportionality represent better and quantitative statement of the company's position? If, as our article cites, The Heartland Institute received nearly a million dollars from ExxonMobil in the last two decades, this is about two hundred times smaller than the amount ExxonMobil Foundation contributed to fight malaria, promote STEM education, and provide worldwide economic opportunities for women in just one single year. Why is your narrative focused on funding of a group that was less than one-hundredth of one-percent of total corporate giving? Might you consider that the journalistic coverage you have read sacrificed coverage of all pertinent facts in deference to a juicy story about an evil corporation? It is sensationalism. "Large corporation with multi-billion-dollar budget does not explicitly vet every unpalatable view promoted by one organization among the thousands it has ever financed" - hardly a headline that sells papers draws web traffic! "Evil company finances mega-conservative anti-science agenda" - it just draws the crowd better. But it isn't the whole story.
Might you consider that it is factually true that certain external individuals benefit financially by promoting a slanderous view of a corporation, or by cherry-picking examples to shed a bad light on the company's efforts? In the spirit of becoming fully informed, have you considered this: who funded the journalists that "dug up the dirt" on ExxonMobil's climate science? Citation: here are some of them and here is a rundown of their financial interest.
Are we to believe, without question, that these journalists are purely altrusitic truth-seekers, or that their narrative has more merit because it is not financed by an oil company? Both sides of this narrative are driven by financial interest. Large energy corporations equally have a financial interest in promoting themselves in the media and presenting themselves in the best possible light. If we wish to actually extract scientific truth, it takes a lot of work.
It has been my experience that energy production companies are fact-driven: more than any other industry I have ever found. Unlike many other industries, their entire business model depends on production and accurate accounting of a very tangible and fungible resource. It is not in their best strategic interest to play the denial game. The companies are large and heavily-regulated, and cannot lie about finances or business prospects. This very same strategic interest in unadulterated truth does not necessarily apply to their opponents, who may include activist shareholders seeking benefit from information asymmetry.
Nimur (talk) 20:03, 1 January 2017 (UTC)[reply]
Regarding Heartland, see Heartland Institute. Dragons flight (talk) 20:15, 1 January 2017 (UTC)[reply]
Nimur, are you aware of the fact that the sources you list are Exxon PR activities and a fossil fuel PR group? I can't even tolerate the amount of salt I'd need to take with those. You also write "Might it be worth evaluating whether the majority of groups funded by the company hold such a view?" to which I say: No, that's an irrelevant point. Even if Al Capone spends the majority of his income on legitimate expenses, that does not mean that hiring hitmen is ok. Note that that holds even if he also hires body guards for a nearby kindergarten. I'd also say that "who funds the diggers" is less relevant than "did they find any dirt"? If you take a second read at this source, you should notice that it's 99% spin and 1% harmless. In particular, Rockefeller is one of the founders of Standard Oil, one of the predecessors of ExxonMobile. Constructing an inherent anti-fossil-fuel bias seems a bit far-fetched here. What exactly is the suggestion? --Stephan Schulz (talk) 06:33, 2 January 2017 (UTC)[reply]
Yes, I am aware that many of the publications I linked are primary sources published by the corporation's media office. I consider primary source information to be a reliable source - not because it is unbiased, but because I understand exactly what its bias is.
Again, it seems that you want to equate the actions of a large corporation to the actions of an actual, literal criminal - even going so far as to construct an analogy to make this point. This is a fallacy of false analogy.
I feel that we are at an impasse; we have assembled the same set of facts, and reviewed the same reference material, but we can respectfully disagree on the conclusions we choose to draw from these facts.
Nimur (talk) 07:54, 2 January 2017 (UTC)[reply]
Indeed. I'm apparently more cynical and/or have a higher standard I hold corporations to. ;-) But I wonder: If you strip the bias from this, what remains? --Stephan Schulz (talk) 20:27, 2 January 2017 (UTC)[reply]
You can hardly be more cynical than I! After you strip the bias away from that article, you are left with the nihilistic conclusion that even in a Western democracy, a great number of very important decisions that will affect all of us are made by privileged people. These people have wealth so unimaginable to us that even smart and educated people like us can barely grasp at an understanding of their actual motives. We - scientists and regular people - worry about climate change on a totally different tier than they. Our problems - the real challenges that we face, economic, environmental, ethical - are not anything remotely like their problems. If our wealth were as limitless as theirs, we could afford to just buy new snow, environmental consequences notwithstanding. Only the Super-Rich Can Save Us! Nimur (talk) 20:50, 2 January 2017 (UTC)[reply]
There is no special difference between very rich people and other people except that they have an awful lot of money. And just because a person wants to have some fun with snow doesn't mean they aren't concerned about the environment. Arabs have invested a lot into developing better energy sources and more efficient buildings. Dmcq (talk) 23:25, 2 January 2017 (UTC)[reply]

I'm not sure whether there's any need to concentrate on ExxonMobil explicitly denying the existance of climate change anyway. (Yes StuRat said that, but we're talking about StuRat so....) Nor do I understand the concentration on regulatory action. These ads mentioned in our article from ExxonMobil weren't just talking about regulatory action, the were talking about the science [7] [8] [9]. And yes they were couched in PR speak but it seems clearly they were expressing far greater doubt over the science than was widely accepted at the time. E.g. as from our article, in 2000 ExxonMobil was still saying " "it is impossible for scientists to attribute the recent small surface temperature increase to human activity." See [10] for some more commentary on the ad.

And this is only the stuff that ExxonMobil was directly saying, as StS has noted, in the meantime they were funding other groups, lobbyists etc who were far less careful in their language. As for nowadays, again as our article notes perhaps their public stance has changed but they are also simultaneously denying that they were ever really involved in efforts to FUD climate change while claiming their is a consipiracy against them [11].

Incidentally while you're correct that accepting climate change doesn't have to mean you accept any regulatory action, let's be clear that ExxonMobil was in fact basically opposing any regulatory action not simply specific actions. Perhaps our article isn't so clear on this but as sources such as [12] note, ExxonMobil was simultaneously telling developed countries like the US they should oppose any action which doesn't include developing countries while telling developing countries they should not accept regulation which limits them. (Incidentally, the same source also says that the CEO presented a study to shareholders in 2000 which claimed cooling when it was already recognised in 1998 that the study had problems and when these were corrected for they showed warming. I didn't find great sources discussing this but there is more info here [13].)

Nil Einne (talk) 06:34, 31 December 2016 (UTC)[reply]

P.S. Since the Exxon Valdez oil spill was brought up, it would be interesting to compare how "responsible" oil companies like Exxon to the environment and accidents depending on whether the place is a developed country or a developing one. I don't have a specific example about Exxon but I do think there's strong evidence both the companies and even the governments of countries like the US treat attempts to hold them responsible. The 2006 Côte d'Ivoire toxic waste dump does come to mind although that didn't involve any of the majors and at least there was some responsibility eventually.) Nil Einne (talk) 06:49, 31 December 2016 (UTC)[reply]

Name these strategies[edit]

1) Is there a name for the strategy of claiming you are for legislation/treaties to stop X, but then finding a flaw in every piece of legislation or treaty that does so, and thus opposing it ?

2) As for the strategy of saying you accept X, but then funding organizations that deny X, I suppose it's called using a proxy, but is there any more specific term ? StuRat (talk) 19:28, 31 December 2016 (UTC)[reply]

Being two-faced and double-dealing. A ruse, a sham, crookedness. Sometimes it's hypocrisy. --Modocc (talk) 05:27, 2 January 2017 (UTC)[reply]
Duplicity. Akld guy (talk) 07:38, 2 January 2017 (UTC)[reply]