Wikipedia:Reference desk/Archives/Science/2014 February 4

= February 4 =

Delta Dagger, part 3
Since at least some Delta Daggers that stood alert in the bad old days were armed with the AIM-26 nuclear air-to-air missile, and since that missile was always under the pilot's direct control, this begs the question: What precautions (if any) were in place to prevent an accidental launch? 67.169.83.209 (talk) 03:10, 4 February 2014 (UTC)


 * Probably none.


 * You have to understand that the W54 warhead was believed to have a yield of only 10 to 20 tons of TNT (although subsequent tests suggest it may have accidentally been much higher). A version of it intended to be fired from a shoulder-mounted infantry weapon was said to be able to destroy buildings within a 2 block radius.   That's comparable to a GBU-43 conventional weapon which has a an explosive charge equivalent to 11 tons of TNT.   As such, the consequences of an accidental launch were not that much worse than a large conventional weapon.  Nowadays, the stigma of accidentally detonating a nuclear weapon would be horrific compared to the same amount of explosive power in a conventional bomb...but back in the cold war, not so much!   So the idea of needing a decision to launch at the presidential level of the chain of command simply didn't figure into the thinking of the time.


 * Remember, "nuclear" has horrible connotations these days - but back then, they were experimenting with nuclear powered airplanes (flying the test model with an unshielded, working nuclear reactor on board over downtown Fort Worth, Texas!) - there was talk of nuclear powered cars!  The technology simply didn't have the big scare factor it has now - so a 10 ton-equivalent warhead was no big deal for a pilot to launch on his own decision...at least no more than a pilot would be restricted in dropping a GPU-43.


 * SteveBaker (talk) 14:57, 4 February 2014 (UTC)


 * If you want to do some more research on this, I would recommend the book Command and Control by Eric Schlosser - it is a very good introduction to the history of nuclear weapons, and is presented in a style which is clear, engaging and relatively easy for a normal person to understand. 109.176.201.53 (talk) 21:49, 6 February 2014 (UTC)

Maverick missile
Was the AGM-65 Maverick developed from the AIM-4 Falcon, or does it just happen to look similar? 67.169.83.209 (talk) 03:14, 4 February 2014 (UTC)


 * This article says it's "reminiscent" of the Falcon. This one says "The AGM-65's configuration is similar to that of AIM-54 Phoenix and AIM-4 Falcon missiles". I can't find anything that says it actually was developed from the AIM-4, but it would make sense if it was. Alansplodge (talk) 16:30, 4 February 2014 (UTC)

change in top #11 - #100 leading causes of death over the last 73 years
I'd like to know, over time, how the top #11 - #100 leading causes of death worldwide has changed over the last 73 years.

Is there some graph that might show this clearly? 212.96.61.236 (talk) 19:31, 4 February 2014 (UTC)
 * WHO has a vast database of statistics. It wasn't formed until around the 1940's but it is a good place to start. . They don't tend to have graphs but rather excel spread sheets.--Aspro (talk) 20:12, 4 February 2014 (UTC)


 * RIGHT, that's what I'd like to know! 212.96.61.236 (talk) 23:00, 4 February 2014 (UTC)


 * ( HAHaha HAHaha  HAHaha HAHaha HAHaha   HAHaha  μηδείς (talk) 04:39, 5 February 2014 (UTC) )


 * Just to clarify why Medeis is so amused, Aspro meant World Health Organization when he typed "WHO". There is a link in his response to some of the WHO's factsheets. K ati e R  (talk) 12:53, 5 February 2014 (UTC)
 * And re-reading, it sounds to me like you were aware and making a deliberate joke and I think I should not post things here before I have my coffee... K ati e R  (talk) 13:13, 5 February 2014 (UTC)
 * If your addressing that comment to me, then no. I posted it in all innocence; assuming that the capitalization made it obvious that I was referring to the World Health Organisation. I feel however, gratified if μηδείς may have found it amusing, as the last time I made a woman laugh was when on vacation in the south of France and  I took off all my clothes on a nudist beach (in mitigation, it was early spring and the wind was very, very  cold -so that too was physiological rather than intended).--Aspro (talk) 21:27, 5 February 2014 (UTC)
 * No, my first read was that the IP read your response as a question and simply didn't get what you were saying, which is a pretty amusing response. When I looked back while more awake, I read it more as a deliberate joke on their part, and realized that they weren't confused by your response. K ati e R  (talk) 13:09, 6 February 2014 (UTC)
 * I am still literally laughing out loud at 212's response three days later. I wouldn't laugh at shrinkage though. There was a traumatic incident once at the local pool when I was little.  A young boy who couldn't get his trunks back on after using the bathroom on a cold day at the beginning of the season walked out of the men's room naked, and a little girl saw him and screamed, "His penis is gone!" and everybody started screaming.... μηδείς (talk) 01:35, 8 February 2014 (UTC)


 * Cue Who's on First?. --   Jack of Oz   [pleasantries]  01:43, 6 February 2014 (UTC)
 * Is there a Latin phrase for "for heaven's sake let the title suffice"? —Tamfang (talk) 08:32, 8 February 2014 (UTC)
 * Dimitte, obsecro, in nomine satis. --Aspro (talk) 01:14, 9 February 2014 (UTC)

accelerated regions in dna
are they usually associated to deleterious changes? thank you --95.233.126.241 (talk) 20:43, 4 February 2014 (UTC)


 * Not sure how I missed this, but you're speaking of Human accelerated regions, I assume. There can be deleterious mutations in these genes (I'd suggest looking them up individually) but you can have deleterious or neutral mutations in any region, conserved or accelerated.  Over millions of years, some beneficial mutations may have piled up in the accelerated regions, though there are other explanations provided for the degree of dissimilarity. Wnt (talk) 22:11, 7 February 2014 (UTC)

Chap stick and cold sores
I've seen conflicting information online about the use of chap stick during cold sore outbreaks. Can the cold sore virus be transmitted onto the chap stick, and from there back to the person after the outbreak, or to another person? If so, how long can the virus survive on the chap stick? --BDD (talk) 22:05, 4 February 2014 (UTC)


 * Not a full answer, but a start: this paper titled "Human herpes simplex virus infections: Epidemiology, pathogenesis, symptomatology, diagnosis, and management", says The principal mode of acquisition is through direct exposure of mucous membranes or abraded skin to the lesions or mucosal secretions of an individual with active primary or recurrent infection. Virus can also be transmitted by respiratory droplets or exposure to mucocutaneous secretions of an asymptomatic person shedding the virus in the absence of clinical disease. HSV1 is primarily associated with oral, pharyngeal, facial, ocular, and central nervous system infections and largely transmitted by oral secretions and nongenital contact... HSV1 can remain viable on the skin, clothing, or plastic for brief periods, facilitating transmission through close nonsexual contact, such as kissing on the cheeks or sharing common utensils
 * (wikilink, emphasis and removal of inline references by me) -- the point is, if there were any known, significant risk of transmission via chapstick, I'd suspect this (2007, highly cited) paper would have mentioned it in that section. I don't know how short of time "brief" means to these authors, but I suspect it on an order of hours, not weeks. SemanticMantis (talk) 22:25, 4 February 2014 (UTC)


 * 1) You should never share chap sticks.
 * 2) Medicated chap sticks should kill any virus but refer to point one.
 * 3) Recovery from a cold sore usually means your immune system has kicked in and you wont reinfect yourself.
 * 4) Prolonged use can dry the epidermis of the lips causing cracking. --Aspro (talk) 22:37, 4 February 2014 (UTC)


 * Lips have epidermis? —Tamfang (talk) 08:40, 8 February 2014 (UTC)


 * Thanks. The paper is very informative, and seems to disprove the apocryphal evidence I found of people re-infecting themselves with old chap stick. Man, if you can't trust Yahoo Answers, who can you trust anymore? --BDD (talk) 23:20, 4 February 2014 (UTC)
 * Ha! Keep in mind that re-emerging or recurrent infection need not (as far as I know) correspond to new exposure or transmission. It can just lie dormant without producing symptoms, then flare up based on other factors. That is very easy to confuse with "re-infection". SemanticMantis (talk) 00:09, 5 February 2014 (UTC)


 * It's hard to find someone giving a number, but sharing lip balm is a known cause of meningitis infections. In the absence of specific data about a lip balm and HSV1, I wouldn't want to predict whether there could be a connection or not.  The issue may not be literal "infection" with the HSV1, which is already in the cells, but whether some product of HSV1 could linger in the stick that might tell other HSV1 lying dormant in cells that it is time for another attack - perhaps indirectly, i.e., the immune system recognizes fragments of HSV1, steps up enforcement, ends up activating HSV1 in the targeted cells.  But it's useless to speculate a mechanism without hard data in hand whether the effect happens at all, which it likely may not, except to illustrate that we can't call things "impossible".  P.S. to editorialize a moment (hopefully we shall not call this medical advice as it is a subclinical, i.e. non-medical, condition), I should call attention to Ariboflavinosis, which says that a) riboflavin deficiency is marked by severely dry/cracked lips, and b) nearly 1/10 of Americans have "subclinical" riboflavin deficiency.  I've never used lip balm, but in rare instances that I've noticed any roughness I grabbed a multivitamin. Wnt (talk) 00:27, 5 February 2014 (UTC)
 * I'm guessing you don't live in an area where it is cold, dry and windy for a significant proportion of the year - dry lips for me are exclusively a winter phenomenon, and specifically an outdoors winter phenomenon (if I don't spend a lot of time outdoors my lips don't get cracked). I find lip balm to be essential in such conditions . Equisetum (talk &#124; contributions) 16:40, 5 February 2014 (UTC)