Wikipedia:Reference desk/Archives/Science/2016 March 14

= March 14 =

Erecting a species
See. Is it normal to say that a naturalist "erected" a species or other taxonomic group? Nyttend (talk) 14:53, 14 March 2016 (UTC)


 * Looks like it could be vandalism to me, or a non-native english speaker mis-translating. Polyamorph (talk) 15:11, 14 March 2016 (UTC)


 * Though not a biologist, I often read natural history and palaeontological articles, books and even original papers. I have come across this expression, so would certainly dispute that it's vandalism. The term might be neutral, or might have the implication that the naturalist was (in the view of the writer) mistaken in proposing the species, etc., in question. {The poster formerly known as 87.81.230.195} 185.74.232.130 (talk) 15:31, 14 March 2016 (UTC)
 * Regarding your "implication" comment: are you meaning something like "John Doe erected Cervus johannensis in 1958, but two years later it was discovered that Linneaus had described the species as Cervus elaphus two centuries earlier"? Nyttend (talk) 15:38, 14 March 2016 (UTC)
 * Right, or maybe "Jones erected Flobosaurus jonesorum as a species, but later Cheng showed that the specimen comprised the bones of two other species. Like TPFKA above, I want to say I've heard this usage, but I cannot find a similar example. I would read it as largely synonymous with "proposed" or "posited". SemanticMantis (talk) 15:55, 14 March 2016 (UTC)


 * Searching "erected a species" and especially "species was erected" produces a good number of hits. Understanding the precise implications of this wording may be trickier. Wnt (talk) 16:26, 14 March 2016 (UTC)


 * Yes you're right, my initial search was insufficient, I take back my original comments. Polyamorph (talk) 12:58, 15 March 2016 (UTC)


 * By what I know, yes is the answer. In several books I have read, the term is common, and I have used it myself in several articles without any hassle; but I am no expert on such things, so correct me if I happen to be wrong!Megaraptor12345 (talk) 12:01, 17 March 2016 (UTC)

Is it dangerous to eat a lot of eggs?
Is it dangerous to eat a lot of eggs? If it is, what is the normal number range of eggs that it's possible to eat from aspect of health? (I listen in the past that eggs are dangerous because they contain a lot of cholesterol, but yesterday I checked on wiki and I saw that the eggs have no cholesterol, that why I suspect that something here is wrong, but I'm not sure) 93.126.95.68 (talk) 15:35, 14 March 2016 (UTC)


 * I paste & searched google with your question and found this: on mayoclinic.org. Jarkeld (talk) 15:48, 14 March 2016 (UTC)


 * Interesting that they only recommend up to 7 eggs a week, or one a day (fewer for diabetics). That's not a lot.  Their commentary that the cholesterol in eggs isn't much of a problem would lead me to think that more than one a day might be OK, especially considering all the nutrients the yolks have, so I wonder why they limited it to that. StuRat (talk) 16:40, 14 March 2016 (UTC)


 * They do have lots of cholesterol, but it doesn't seem to have much affect on our body cholesterol. One concern is the salt you might put on the eggs.  I need to add salt to hard-boiled eggs, but not if they have a runny yolk.  You might try them that way, and see if the same is true for you. StuRat (talk) 16:37, 14 March 2016 (UTC)


 * If you're eating them competitively, you might choke under pressure. Precision beats speed. InedibleHulk (talk) 22:34, 14 March 2016 (UTC)
 * Now this is a lot of eggs, and no serious (short-term) side effects. InedibleHulk (talk) 22:40, 14 March 2016 (UTC)
 * I discovered that what I read about the lack of the cholesterol was about the white part only. So in case of using the white part only there is no cholesterol there at all - according to the article on Wiki. 93.126.95.68 (talk) 01:08, 16 March 2016 (UTC)
 * If the eggs are not cooked, the avidin can cause egg white injury i.e. biotin deficiency. And of course runny eggs carry a certain cumulative risk of salmonella etc. Wnt (talk) 23:30, 14 March 2016 (UTC)


 * Both my brother and I remember hearing from "somewhere" a long time ago that eating more than 1 or 2 eggs a day is bad for you, and we have come across more than a few people who thought they heard same thing, but like you we've never been able to find a good source for that claim. It's like, an old wife's tale or something.. Vespine (talk) 03:42, 15 March 2016 (UTC)


 * Until recently the reason was that the high cholesterol in egg yolks was assumed to cause high cholesterol in people who ate them. StuRat (talk) 03:46, 15 March 2016 (UTC)


 * So one of those Egg Council creeps got to you, too, huh? InedibleHulk (talk) 09:17, 15 March 2016 (UTC)


 * Yes, your house can only get egged just so many times before you would knuckle under, too. :-) StuRat (talk) 19:55, 15 March 2016 (UTC)


 * Eggs are powerful food, enable the liver to convert nutrition energy the from the eggs over hours into glucose. Good wor workers, bad for diabetes affected peaple, maybe to powerful to sleep at night when eating eggs in the evening, but not to beat in the poteines eggs contain when not cooked too long. -- Hans Haase (有问题吗) 04:09, 18 March 2016 (UTC)

Are there Propane detectors on the Exomars probe, and, if not, why not?
The Exomars project's lead scientist quoted in our cited February 2016 Guardian article (cited in our article on the Exomars mission) appears to imply that the probe will be looking for propane (as a possible signature of biologically created methane), without explicitly saying so, but the September 2015 paper we also quote doesn't mention propane as one of the substances it can detect. Our article correctly reflects both sources, but is thus rather confusing to me as a reader. I've left a question about this here on the article's Talk page, but as those who wrote the article would probably already have prevented the confusion if they knew how to do so, I think I may well get a more expert answer here quicker and more reliably.Tlhslobus (talk) 16:35, 14 March 2016 (UTC)
 * There is no any propane detectors on the spacecraft or for that matter a detector for any other chemical substance. The spacecraft relies on universal spectrometers, which can detect any chemical in the atmosphere provided it has an observable spectral signature. Ruslik_ Zero 19:42, 14 March 2016 (UTC)
 * Thanks, but unfortunately you haven't really answered my question since you don't say whether the universal spectrometers can detect the spectral signature of propane (under Martian atmospheric conditions), let alone provide a reliable source to back up such a claim. (Incidentally, I'm sorry if you failed to understand that I was using 'propane detector' as shorthand for 'equipment that is capable of detecting propane'.) The cited source in our article mentions a large number of chemicals that are detectable, but not propane, even tho it seems to be one of only two gases (the other being ethane, according to another of our sources, which seemingly doesn't say that ExoMars can detect propane) that can tell us whether Mars's methane is of biological origin. Hence I would like some reliable source to tell me unambiguously (not implicitly as in 'if propane is detected...', which might be a way of being 'economical with the truth') that ExoMars can detect propane. (Incidentally, I'm not sure how relevant this is, but if it can't, that may arguably raise awkward questions about whether this taxpayer-funded mission is up to the job, and whether this is being hidden from us - but any such questions will be scotched by a proper source explicitly saying it can detect propane). Alternatively, if it can't detect propane, it would be interesting to know why it can't, and whether how badly that might undermine the stated purpose of the mission. Tlhslobus (talk) 15:46, 15 March 2016 (UTC)


 * From the ESA's Mars Exploration website, here is the list of trace gas orbiter instruments. The Atmospheric Chemistry Suite is tuned to precisely measure certain specific molecules that scientists already know they will find; but the same instrument can also "search for undetected species."
 * Whether the equipment could detect propane - and whether scientists believe even tiny amounts of propane could exist in Mars' atmosphere - are deep research questions. Your best chance for getting an accurate answer is probably by contacting the principle investigators.  I'm not sure why you would believe that propane is the key to the entire mission: the program overview clearly states that the mission is to "demonstrate a number of essential flight and in-situ enabling technologies that are necessary for future exploration missions;" the scientific investigations, including the trace gas investigations, are icing on the proverbial cake.  Even if the capabilities of one particular instrument doesn't live up to your arbitrary expectation, that hardly "undermines the stated purpose of the mission."  Surely, as you have found in the Guardian article you mentioned, scientists will eagerly analyze any data that they retrieve, because the implications of any discovery might be important - but that's not the stated purpose of the mission.
 * Regarding your comments about the funding of these missions: Exomars is an ESA mission. Most of the ESA's total budget in 2015 was money from Germany, France, and Italy; 86% of the money comes from the EU, 10% comes from the EU in the form of Eumetsat budget, and the other with the remaining money comes from other sources.  A paltry 0.6% of the total ESA budget came from Ireland, just barely edging above the contribution from Greece.  To put this in context: the average Irish citizen contributed less than 0.01 Euro per year to the entire ESA Robotic Exploration program, of which only a tiny fraction went to fund this specific instrument on this specific mission.
 * Nimur (talk) 17:12, 15 March 2016 (UTC)


 * To expand a little on the ref's that User:Nimur gave, they both menation: “The first scientific goal will be to detect a broad suite of atmospheric trace gases, and key isotopologues (molecules that have at least one atom with a different number of neutrons than the parent molecules), to establish the atmospheric inventory.”
 * “profile isotope ratios for HDO/H2O, 13CO2/CO2, CO18O/CO2, among others;” (emphasis both mine).
 * Detecting the existence of propane -in itself- doesn’t help (much) unless one has more data to indicate if its origin is simply geologic or biologic. Isotope analysis will help. --Aspro (talk) 20:02, 15 March 2016 (UTC)
 * Thank you both for your very useful links, which once again list lots of detectable chemicals, but not propane. I shall not bother responding to the questionably relevant  unflattering comments regarding my country's contribution. Meanwhile thanks for in effect confirming that everything the media have been telling us about the purpose of the mission being to find life on Mars would seem to be hot air that is misleading the public. As for where the blame may or may not lie for this apparent misleading, that is probably not a question that can be usefully discussed here, so I'll leave it at that.Tlhslobus (talk) 03:04, 16 March 2016 (UTC)


 * Whoops, forgot to answer the OP's question. Propane is not mentioned pacifically because science writers like to keep things simple. In fact they may even know that the butane in ones gas lighter (if one smokes) is different form the butane in ones domestic butane cylinder (if you live of grid and use LPG). When reference to methane is mentioned in popular science journals is is a euphemism for any hydrocarbon gas in that group where methane is the most abundant.   Methane does not occur in isolation though. The instrumentation of these modern robots can distinguish these different  hydrocarbons and provide a ratio, but  since writers always  underestimate the comprehension of their readership. They are writing to appeal to the lowest common denominator – i.e., John Doe. Propane therefore, is so far not mentioned. For heaven-sakes, one can buy sensors that detect  Methane, Natural Gas, Ammonia, Hydrogen Sulphide, Propane, Acetone, Petrol, Naphtha, Smoke, Steam, Lacquer Thinners, Jet Fuel, Butane, Industrial Solvents, Alcohol Alarm, etc. on  [] . These planetary probes cost the US tax payer billions and can do more the a science writer thinks John Doe can get his head around.--Aspro (talk) 12:16, 16 March 2016 (UTC)

What is the maximum value for GFR?
I know that it is theoretically possible for glomerular filtration rate (GFR) to keep going up and up to infinity. But, realistically, what is the maximum value that would be considered acceptable? For example, I am pulling serum creatinine values from a public health database. I'm using the serum creatinine to estimate GFR. I have one patient with a eGFR of 10629. I assume that is beyond the acceptable limit, but that implies that there is an acceptable limit. So far, after four hours of Googling, I haven't found any minimum/maximum values for GFR. 209.149.113.14 (talk) 17:32, 14 March 2016 (UTC)


 * What kind of serum creatinine level gets you a result like that?? You might look for the accepted limits on that value, rather than the derived figure.  (our article on creatinine indicates reference ranges - I haven't looked to see if there's any viable mutation that would allow a person to just not make creatinine in the first place, though I presume it is at best many orders of magnitude less likely that faulty data in your database)  Beyond that, I'm thinking you're in statistics territory, trying to discard outliers. Wnt (talk) 23:34, 14 March 2016 (UTC)


 * Seeing as "normal" eGFR starts at 90, my default assumption would be that the value is erroneous. Maybe it's supposed to be 106 and someone accidentally hit extra keys while entering it. --71.119.131.184 (talk) 02:47, 15 March 2016 (UTC)


 * I believe they vary by race and danger/health concerns are modulated by cause. Creatine kinase levels are a useful metric for injury/disease and there is also the clinical observation of urine.  --DHeyward (talk)

File:Sajama.jpg
This file is named "Sajama", but it looks more like Parinacota to me - conical shape in front of a lake. Does anyone know which mountain this is for sure?Jo-Jo Eumerus (talk, contributions) 19:49, 14 March 2016 (UTC)
 * Based on my own research and File:Parinacota volcano 1995.jpg it looks like Parinacota indeed. Thus withdrawing request.Jo-Jo Eumerus (talk, contributions) 16:33, 15 March 2016 (UTC)

What holds tangerine lobules together?
How exactly tangerine and similar Citrus fruit lobules are attached to each other before separation for consumption? The sound of separation in tangerine reminds adhesive tape, but upon separation no traces of attachment can be seen. Thanks. 93.174.25.12 (talk) 21:39, 14 March 2016 (UTC)


 * Adhesives don't always leave a residue. Sticky Notes, for example, don't leave any.  However, see cohesion for the tangerine case.  StuRat (talk) 22:01, 14 March 2016 (UTC)


 * Sticky notes definitely normally have residue on the sticky note unless it get's so dirty it's no longer adhesive. Nil Einne (talk) 23:01, 14 March 2016 (UTC)


 * Yes, but none on what they were stuck to. StuRat (talk) 00:03, 15 March 2016 (UTC)


 * Yes but your claimed adhesives don't always leave a residue, not that they don't always leave a residue on one part of the two parts that were stuck together. Even if you had said the later, that has nothing to do with the OP's point unless you're claiming that the citrus fruit lobules do have residue on one lobule the OP just keeps feeling the wrong one.... Nil Einne (talk) 13:49, 15 March 2016 (UTC)


 * I wasn't answering the Q about citrus sections there, but rather the assumption that adhesives must always leave residue. My cohesion link is the answer to the actual Q. StuRat (talk) 20:00, 15 March 2016 (UTC)


 * The stickiness you hear when pulling the carpels/lobules/chunks apart is only incidental to their being held together by the albedo for a while. Not much to do with the albedo or the albedo. InedibleHulk (talk) 23:54, 14 March 2016 (UTC)