Wikipedia:Reference desk/Archives/Science/2014 March 10

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March 10

Early-diagnosis pancreatic cancer

After noting that early diagnosis is rare due to the lack of symptoms, the Pancreatic cancer article goes on to say that the 5-year survival rate for local disease is just 20%. The sourcing is solid, [1] and [2]. I'd previously assumed that the disease's low survival rate was due simply to the difficulty of catching it early, and that most people with an early-caught pancreatic cancer would survive, comparable to things like ovarian cancer (92.7% five-year survival when caught early, per the article) or melanoma ("the chance of cure is high" when caught early, per the article). Why is pancreatic cancer different? Nyttend (talk) 01:37, 10 March 2014 (UTC)

It looks like the catch is the "when caught early" part - that pancreatic cancer is seldom caught early. Much easier to catch melanoma early, one would think. ←Baseball Bugs ^{What's up, Doc?} carrots→ 02:45, 10 March 2014 (UTC)

But that's the thing: "local disease" definitely sounds like "caught early", but you still have a 4-in-5 chance of dying within five years if your pancreatic cancer is caught early. Ovarian is really hard to catch early ("It is disproportionately deadly because it lacks any clear early detection or screening test, meaning that most cases are not diagnosed until they have reached advanced stages"), but that doesn't keep it from having a high 5-year-survival rate when caught early. Nyttend (talk) 02:59, 10 March 2014 (UTC)

I interpreted "local" to mean "not spread to other organs yet". ←Baseball Bugs ^{What's up, Doc?} carrots→ 03:05, 10 March 2014 (UTC)

I don't think that's the meaning in the article, because separate statistics are given for "locally advanced", which has a 10-month average survival rate. Judging by cancer staging, the latter is stages 2-3, while the "local disease" is stage 1. Anything below stage 4 is "not spread to other organs yet", and presumably the death rate for stage 3 is substantially higher for pretty much any cancer than is the death rate for stage 1. Nyttend (talk) 03:10, 10 March 2014 (UTC)

Hmm... well, it sounds like we need an expert here. ←Baseball Bugs ^{What's up, Doc?} carrots→ 03:14, 10 March 2014 (UTC)

• It helps to keep in mind that cancer is not one disease. It's basically a symptom--unregulated cellular reproduction. There are some 200 human cell types, hence at least 200 different types of cancer. It's very similar to talking of broken bones. Broken fingers rarely kill, broken necks and spies and hips and skulls moreso. Well overa year and a hald ago I asked about lung cancer that had spread to the brain. Chances were someone with that stage inoperable lung cancer with two separate spots in the brain had well under a 6 month average survival rate--she's in remission today.

As for people with pancreatic cancer, my parents, in their seventies, know at least 6 who have been diagnosed, and only one now living, and on his last legs. None lived more than two years from diagnosis, which in almost every case was asymmetric back pain. Who gets back pain and thinks pancreatic cancer? The other symptom is type 2 diabetes, which many people expect from lifestyle and family history. Here's a good article from CNN on th topic that killed Patrick Swayze and Joan Crawford Steve Jobs and is the fourth most deadly form of cancer after lung, breast, and colon: See . μηδείς (talk) 03:55, 10 March 2014 (UTC)

As for five years, see these articles. μηδείς (talk)

This link to a very recent article is of great relevance to the discussion. http://www.newscientist.com/article/mg22129583.000-pancreatic-cancers-killer-trick-offers-treatment-hope.html#.Ux1odblWE5s Tom duF (talk) — Preceding undated comment added 07:32, 10 March 2014 (UTC)

Um, is this real? I see a lot of online ads for "simple trick solves [huge health problem], so the use of "trick" in the headline makes me suspicious that it's spam. It also doesn't really answer the question. Nyttend (talk) 13:05, 10 March 2014 (UTC)

Yes it's real, New Scientist is a well-respected (if populist) science journal in the UK, and I note their footnote that the print article was originally titled "Pancreatic cancer's weak spot found". --TammyMoet (talk) 13:28, 10 March 2014 (UTC)

It may have been respectable at one time, but it has terrible journalistic standards these days, at least in areas where I have some expertise (medicine isn't one). I'm sure this research is real, but the realistic possibility of its turning into a cure for pancreatic cancer is probably much lower than the reporter wants it to seem. -- BenRG (talk) 21:11, 10 March 2014 (UTC)

New Scientist has never been respectable - it has always been what Scientific American has degenerated into, and even in its salad days, SciAm was just a tony popular-audience magazine, not a scientific journal. That being said, what would impress me would be a published paper on "pancreatic cancer's weak spot" in a peer-reviewed medical journal (my publication list includes papers in several such journals). Science or Nature would do; the New England Journal of Medicine would not, as it panders to medical politics; it is NOT a serious medical journal. Of course, a peer-reviewed article in Cancer or any other specialist medical journal where the peer review is apt to be searching and informed by clinical experience would be best. loupgarous (talk) 23:01, 11 March 2014 (UTC)

Steve Jobs died of a cancer of the pancreas, but it wasn't adenocarcinoma, the common and famously deadly one. -- BenRG (talk) 21:11, 10 March 2014 (UTC)

As I remember Ruth Ginsburg had pancreatic cancer in 2009—five years ago and she is still alive. Ruslik_Zero 19:17, 11 March 2014 (UTC)

See also this article. Ruslik_Zero 19:22, 11 March 2014 (UTC)

Sorry, I forgot I didn't post before - the excitement seems to trace back to mitocans such as alpha tocopheryl succinate (note: be sure to search for "mitocans" plural on PubMed - for some reason the site doesn't return the same results for the singular in this case!). I'd like to be hopeful, but the idea has been around for some time and seems a little short on miraculous results. Still... anything helps. Wnt (talk) 17:56, 12 March 2014 (UTC)

Finding academic reviews of Murry Salby's published work

Hi, this climatologist has published dozens of peer-reviewed articles, and two textbooks. I'm hoping to find guidance on locating reviews of his work, as well as how to structure presenting the information. Doe sit make sense to list all his peer reviewed published work. How do we note which ones are most notable and should definitely be talked about? Etc. Any help appreciated. Sportfan5000 (talk) 11:16, 10 March 2014 (UTC)

"How to structure presenting of the information" -- do you mean you plan on improving/extending his WP article, or is this for some other project? There will be different best practices depending on where you are presenting your work. One way to get a feel for the notability of an academic paper is it's citation count (available via google scholar), and perhaps the impact factor of the journal where it was published. I would not recommend listing all his published work. Our article says he has published over 100 articles (which is about right for a productive scientist of his age), and I doubt they are listed in full anywhere, except perhaps on his own curriculum vitae. As for reviews of his work, that is tricky. If you just google his book names, you get tons of blog posts and user reviews, which are not WP:RS. I suspect that e.g. nature_(magazine) or science news or science_(magazine) may have published some reliable reviews of his books when came out, but you'd probably have to have good online access through a university to search their archives. As for the articles, those don't usually have "reviews" written about them by experts. That is done privately by the journal before the article is published. Once it is published, the reader trusts that the editorial board of the journal has verified that the work is basically correct, viable, and of interest to the community. Some articles have "responses" published by other authors in the same (or next) issue of the journal, which are usually critiques of methods or conclusions. Basically, do not trust normal web searches for this guy. He is pretty unique, in that he is an actual atmospheric scientist who denies human-caused climate change, and that colors everything that you will see on google. (As far as I can tell, he is still not a specialist on climate change per se, rather being focused on upper atmospheric wave propagation for most of his early career.)SemanticMantis (talk) 14:37, 10 March 2014 (UTC)

Thank you for your thoughtful reply. This is only to help improve the WP article, I have no interest in the entire subject area outside of the article.

Looking at impact factor, it seems tied more to the journal than to the articles it contains so it may make more sense to note which of Salby's articles have the highest citation count.

I have not seen a curriculum vitae for Salby, and it doesn't seem like he promotes himself or his work, but has been doing some speaking engagements linked to global warming more recently.

Mid-2000s his entire work lab was dismantled, with varying disputes why, but the net effect is likely all his work in process was disrupted, so I'm trying to focus on accurately portraying his work from early 1980s-2005/6. Sportfan5000 (talk) 22:49, 10 March 2014 (UTC)

He jumped between at least a few different universities at the level of Associate prof. or higher. I guarantee you he was promoting his work in his field to achieve that! As for impact factor, think of that as a way of assessing the general prestige of a journal. Consider a made-up example: if he has two articles, each with 50 citations, the one in "Nature" will be more notable than the one in "Journal of Atmos. Sci", since "Nature" has a higher impact factor. One of the reasons that it is hard to get into Nature is that it covers all areas of science, so any particular article is seen by the editorial board as not only the top of its field, but so important that even non-specialists should know about it. As for the CV, I suspect you might find an old one online if you search long enough. But, not all academics post them to the public (I don't). It might be a long shot, but you could try to just ask him for it. If you are polite and say you want to use it to improve his WP article, he might go for it. Note the CV itself will not be a WP:RS, but it can point you towards sources that are. I really think the best thing in this case would be to look for "response" articles or "book review" blurbs in the major science rags. Finding the existence of such things is usually free/open, check at WP:REX if you need help getting access to full text. SemanticMantis (talk) 15:23, 11 March 2014 (UTC)

• Note: I am copying this to the article in question so it can aid in that article. Sportfan5000 (talk) 21:39, 15 March 2014 (UTC)

Remembering things only in a sequence

I can only recall, say, the 6th digit of my phone number by going through the first five. It's the same with say, the letter before Q in the alphabet. Is there a name for this kind of memory to distinguish from others? --129.215.47.59 (talk) 13:22, 10 March 2014 (UTC)

Wikipedia lacks an article about the concept, but I find visual sequential memory to be a common term, defined as "the ability to remember a number of items, letters, numbers, or shapes in series". --Jayron32 13:33, 10 March 2014 (UTC)

Sequence learning is about how we learn this way. Chunking (psychology) is used mostly with memory tasks -- how we group things together to remember them (in sequences, among other ways). The method of loci (an aspect of the art of memory) is an ancient technique for remembering things that involves a similar idea to chunking. I fear none of these will provide a great explanation for why you would be unable to remember things otherwise, though. --— Rhododendrites ^talk |  15:56, 10 March 2014 (UTC)

Our brains are wired for certain things. Learning a phone number could be important. Focusing on a specific digit does not seem so important. Of course, individual talents will vary, and practice and time can help. I can run through the calendar in my head and tell you how many days are in each month. But for many it may still be easier to use the old "30 days hath September" thing. ←Baseball Bugs ^{What's up, Doc?} carrots→ 17:13, 10 March 2014 (UTC)

Why do they even need that? Alternate long/short. Start again at Aug. Feb is not 30. I think that's fewer things to remember than 30 days hath september. Sagittarian Milky Way (talk) 23:57, 10 March 2014 (UTC)

What you've just described fits what's called the "knuckle method" of recalling the days in each month. But some folks remember poetry more readily than cold hard facts. ←Baseball Bugs ^{What's up, Doc?} carrots→ 00:51, 12 March 2014 (UTC)

The July and August regions have the best weather of the year, they deserve to be longer. Sagittarian Milky Way (talk) 03:05, 12 March 2014 (UTC)

A certain form of Context-dependent memory, perhaps?198.86.53.69 (talk) 18:48, 11 March 2014 (UTC)

The king of sequential memory has to be whale songs of humpbacks, which can be very long. Presumably they can't just start in the middle. StuRat (talk) 17:21, 10 March 2014 (UTC)

I know spelling works that way for me. For example, if asked to name countries which start with a certain letter, I likely will do much better than if asked to name nations which end in a certain letter. StuRat (talk) 17:25, 10 March 2014 (UTC)

discoveries of nasa space station

respected auditor i have heared that a space shuttle or spaceship have discovered strange voices from space but scientists have not discovered that from where the voices are coming so please tell me about what have scintists discovered from space As i am eager to get my answer — Preceding unsigned comment added by 119.154.28.74 (talk) 14:57, 10 March 2014 (UTC)

Do you mean the Wow! signal? --Jayron32 15:19, 10 March 2014 (UTC)

You have apparently heard something that isn't true. There hasn't been a discovery by a space shuttle, space ship or space station of strange voices from space. But you may be interested in the articles UFO, Ufology, UFO religion and Extraterrestrial life. Red Act (talk) 16:39, 10 March 2014 (UTC)

Wikipedia's lengthy Scientific research on the International Space Station article lists many of the experiments done on the ISS; all very worthy, but not spectacular, academic science. Since the end of the Space Shuttle program in 2011 the only manned spaceflights have been Russian Soyuz flights to the ISS. If anything was going to discover strange space voices it would be SETI, which hasn't yet. -- Finlay McWalterჷTalk 21:35, 10 March 2014 (UTC)

Oops, I forgot three Shenzhou flights; but they didn't hear alien voices either. -- Finlay McWalterჷTalk 22:52, 10 March 2014 (UTC)

Could the OP be referring to the sound recorded by Voyager 1 as it left the solar system (Sound Of Interstellar Space Captured For First Time Ever By Voyager 1 Spacecraft (VIDEO)) ? --Auric talk 00:16, 11 March 2014 (UTC)

When you think about it, this is impossible. Soundwaves can't travel through the vacuum of space - so these can really only have been radio waves or other electromagnetic signals...but all of those things are more easily detected by earthly telescopes and radio-telescopes - or the Hubble and other unmanned satellites - than with any of the instruments on the ISS and various shuttle missions. So it's completely impossible for those missions to have picked up anything we're not already aware of. So, this didn't happen - and whoever told you that it did has either misunderstood or been mis-informed. SteveBaker (talk) 02:41, 11 March 2014 (UTC)

Well, if ET is watching us from a stealth spaceship in low Earth orbit passing closely by one of our own spaceships then I suppose it could happen that their signal is too weak to be picked up from the surface, or maybe they are only transmitting home in a direction away from Earth. I haven't heard such a theory but it might be something a conspiracy theorist could accuse authorities of hiding. PrimeHunter (talk) 03:00, 11 March 2014 (UTC)

An astrophysicist Jocelyn Bell Burnell on first hearing with a radiotelescope in 1967 the "voices" (video) of Pulsar stars noted ""we did not really believe that we had picked up signals from another civilization, but obviously the idea had crossed our minds...". 84.209.89.214 (talk) 02:55, 11 March 2014 (UTC)

Moments

If taking moments about a point, is it only necessary to consider forces on 1 side of that point and not the other? This is what is don't in example 1 in this link, a simply supported beam with a single point load. http://www.freestudy.co.uk/engineering%20science%20h1/outcome%201%20t3.pdf can the same method be used if there were 3 point loads of varying magnitudes at random places along the beam? — Preceding unsigned comment added by 82.40.46.182 (talk) 20:47, 10 March 2014 (UTC)

You need to consider all of the forces, and I think they did. E.g., the first equation in the solution expresses that the torques/moments around the left end of the bar add to zero: R_a × 0 + (−20N) × 0.4m + R_b × 1.0m = 0. -- BenRG (talk) 21:32, 10 March 2014 (UTC)

But M = 12x - 20(x – 0.4) only seems to take into account forces on one side. — Preceding unsigned comment added by 82.40.46.182 (talk) 21:52, 10 March 2014 (UTC)

What they're doing is treating the left part of the bar, from 0 to x, as an object, and computing the moments acting directly on it around an axis perpendicular to the page and located somewhere on the right edge of the sub-bar at x (the vertical position doesn't matter). The moments are the two vertical forces on the left and the bending moment M, which is the integrated effect of the horizontal (normal) forces across the interface with the other sub-bar. M represents the torque from the 8N force as transmitted through the other sub-bar, so also including the 8N torque directly would double-count it. By Newton's third law the bending moment acting on the other sub-bar is −M, which gives a simpler formula M = 8N · (1.0m − x). I'm not sure why they used the more complicated one. -- BenRG (talk) 22:38, 10 March 2014 (UTC)

So can this problem be solved without breaking down into sub bars? I.e. By just considering forces on both sides of the point, in 1 equation? So, also considering the reaction force at B in that equation? 194.66.246.216 (talk) 09:29, 11 March 2014 (UTC)

Is this equation correct? M=12X-20(X-0.4)-(8(1-x))? If not, how would you find the bending moments across the beam, taking into account all forces? — Preceding unsigned comment added by 194.66.246.216 (talk) 09:34, 11 March 2014 (UTC)

The right hand side of your equation simplifies to zero, so it's incorrect. Think of pulling a block by a rope over a level surface against friction at constant speed. You pull on the rope with a force of (say) 10N; the rope pulls on the block with a force of 10N. It would never be correct to add those and get 20N. If you consider the rope and block as a single object, the second 10N force would be ignored because it is an internal force. If you consider the rope and block as separate objects, the two 10N forces would both be included in the calculations, but not added because they act on different objects.

You need to split the bar to compute M because that's built into its definition. From the perspective of the bar as a whole, the bending moment is a neglected internal force. The internal forces can be neglected because they all add to zero, which is more or less why your equation simplifies to M=0. -- BenRG (talk) 19:14, 11 March 2014 (UTC)