Wikipedia:Reference desk/Archives/Science/2015 March 29

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March 29

Bedbugs: Is there speculation among scientists about possible benefits to humans of bedbugs?

I was thinking that maybe bedbugs reduce violent tendencies in people, because the decline and resurgence in bedbug numbers in United States roughly coincided with increase and decline in violent crime in USA. Of course i don't know for sure that would be a benefit in some kind of biological sense, but it would be an effect, and a benefit in a human values sense. I suppose it's a silly longshot question, but on the other hand there may (or may not) be some theoretical virtual certainty among biologists that a longtime parasite like bedbugs should by now have caused some kind of benefits and side effects, and I'm looking for some kind of notable fall and rise of a benefit coinciding with the fall and resurgence of bedbugs. Thanks, and thanks for your answers to the previous question.2601:7:6580:5E3:9440:CEA3:2200:C3CC (talk) 07:05, 29 March 2015 (UTC)

The only reason it would evolve to benefit humans would be if that would also benefit them. It's hard to see why that would be the case here. There is a cat feces virus which may do close to the opposite, though, by increasing risk taking behavior in humans. In this case it seems to be designed to do this in mice, so they get caught as prey and pass the virus on to their predators (one of which is cats). The effect on humans, if any, is just an accident. StuRat (talk) 07:22, 29 March 2015 (UTC)

It's true that bedbugs would be unlikely to evolve to help humans unless it helped them. But we humans may have evolved in some way that makes use of bedbugs. Or there may be just side effects that might or might not be biologically beneficial, but that we value.2601:7:6580:5E3:79CC:4600:8B68:8653 (talk) 06:25, 30 March 2015 (UTC)

StuRat appears to be writing about Toxoplasma gondii, which is not a virus, but an obligate, intracellular, parasitic protozoan. The effect on risk-taking in rodents is well documented (see links in article). Regarding humans, it is suspected but by no means proven. --NorwegianBlue ^talk 09:07, 29 March 2015 (UTC)

See cat lady. μηδείς (talk) 17:00, 29 March 2015 (UTC)

In your case, if the correlation is real, it's much more likely to a common cause - e.g. economic hardship leading to both violence and reduced hygiene . See Correlation does not imply causation. --Stephan Schulz (talk) 09:20, 29 March 2015 (UTC)

Actually that correlation would be backwards; see the OP's statement again. Perhaps you might hypothesize neurological effects from DDT. Or perhaps sociologically, the kind of fanatical enforcement mentality that effectively controls bedbugs has the less beneficial effect of causing a War on Drugs that drives up prices and crimes killed over territory. Who knows? It is very hard to do science of one-off events. Wnt (talk) 12:22, 29 March 2015 (UTC)

Can we classify this new theory a form of discourse analysis? (link provided below)

I am currently studying discourse analysis as a social science research method. While looking for some literature on the subject, I stumbled upon this scholarly article entitled “Discourse Analysis of Public Debates Using Corpus Linguistic Methodologies”. Generally, it argues for the use of computational methods to dissect and analyze public policy debates. Just taking glance at the article got me confused as to what discourse analysis is, as expounded by philosophers and social scientists. As I understood it, discourse analysis uses hermeneutical and qualitative methods to scrutinize the meanings and relations of different forms of communication. I wonder if this article discusses discourse analysis in paradigm similar to that developed by Foucault and other continental philosophers. Did it just borrow the term to discuss a new method that is different from discourse analysis? And, lastly, can we formalize discourse analysis without neglecting the intention of its makers?Rja2015 (talk) 14:41, 29 March 2015 (UTC)

You should start by reading our article on discourse analysis. You should then attempt to learn a little about quantitative discourse analysis/computational discourse analysis, which is one subdiscipline within the field. You are right that in its earlier forms discourse analysis was largely qualitative in its approaches, and much discourse analysis remains qualitative and interpretive. The development of computers and associated software capable of analysing large volumes of text or other communication, however, has allowed practitioners in the field to address one of the criticisms of discourse analysis - namely, that it relies too much on the personal interpretation of the text by a single practitioner. By specifying a set of rules in advance of any study of the text, and then applying these rules in performing the discourse analysis, the personal interpretation element is removed, and replaced by clear measurement. This approach works particularly naturally in conjunction with corpus linguistic approaches, since the tradition in corpus linguistics is largely experimental and (debates about annotation notwithstanding) attempts to minimise bias that might arise as a result of researcher interpretation. As you read the paper, you'll see how the researchers analyse the texts on the basis of word usage, with the vocabulary corpus being listed in e.g. Table II. I have to say, it's a really interesting paper.

As for your questions, I suggest you look at our article on Foucauldian discourse analysis to answer your first (inexplicit) question. I suspect you'll conclude that Foucault was primary concerned with issues such as power relationships, which are only one of a whole range of topics than can be examined through discourse analysis. I'm inclined to suspect that the authors of the paper were more concerned with vocabulary issues, which are relatively easy to quantify, than more complex and subtle issues of relative power. Computers aren't good at such subtleties (yet). For your second question, where you ask if this is a "new method", this question is clearly addressed on p.59 of the paper, in the paragraph beginning "Corpus is generally defined..." and its sequelae. The Austin the authors are referring to is J.L. Austin, whose work strongly supports the view that the best way to understand the meaning of a word is by examining its use. It is incumbent on you as a civilised human being to read his "How To Do Things With Words"; it's a foundational document of much current thinking in this area. The following paragraphs make a case that the paper's approach is consistent with earlier discourse analysis approaches, by emphasising that "corpus linguistics evaluate the ways of using language with actual data of language use". I think the authors see themselves as extending discourse analysis, rather than creating a new method (and, personally, I'd agree with them). As for your last question, I think the answer is that what the authors of this paper are seeking to do is perform a discourse analysis that focuses on vocabulary only. Recall that discourse analysis aims to examine every possible semiotic event. What the authors of this paper are seeking to do is simply to specify formal rules for one particular analysis, and examine the results. There's no larger attempt at formalisation going on. RomanSpa (talk) 18:40, 29 March 2015 (UTC)

Thank you, Roman Spa! Your answer is very informative. One more thing, I've read that critical theorist and critical discourse analysts are staunch anti-positivists. As such, they recognize the importance of their subjectivities and personal biases in emphasizing their involvement in their research. Do anti-positivists, such as critical discourse analysts, see formalization as antithetical to their position?Rja2015 (talk) 23:13, 29 March 2015 (UTC)

Healing

On the animated show the Simpsons, a kid touches a wound and the wound noticeably heals in only a few seconds and the scab thinks it needs to grow over the hand. A dumb throwaway gag sure, but is there any truth to this? If your thumb was dead still on a new scrape till next year what would happen? Hey, wait, if 2 brand new scrapes were put together and never move how would it know to grow 2 skins? 128.177.161.189 (talk) 22:21, 29 March 2015 (UTC)

It might help if you told us which Simpsons episode and when in the show (the minute) the clip appeared. Also, I am American, but find it impossible to figure out what you mean by "If your thumb was dead still on a new scrape till next year" and "if 2 brand new scrapes were put together and never move" means, and what it is in "how would it know to grow 2 skins?" Can you break this down into clearly expressed separate sentences? μηδείς (talk) 23:35, 29 March 2015 (UTC)

I don't know the answers, but I understand those sentences. "If your thumb was dead still on a new scrape till next year" means, if you have a scape and place your thumb on top of it, and hold it there without moving it for a year. "If 2 brand new scrapes were put together and never move" means, if you have a scrape on your body somewhere and another scrape on your thumb, and you place the scraped part of your thumb over the scraped part of your body and hold it there for a long time without moving it. Looie496 (talk) 00:17, 30 March 2015 (UTC)

Yes, that makes sense, but it is way off biologically. See human skin, dermis, and epidermis as well as wound healing. Basically, the scab is inert dead clotted blood that has hardened over a layer of skin where the epidermis has been rubbed/torn off. The basal dermal cells regenerate, producing new skin under the scab, which eventually falls off. In fact, all the outermost skin of the body falls off after a while, we just don't normally see the flakes, except that they constitute a large portion of the dust that accumulates in inhabited rooms. The scab itself plays no active living role, it serves solely to protect the regenerating tissue underneath. μηδείς (talk) 01:34, 30 March 2015 (UTC)

So, grafting not so easy. —Tamfang (talk) 05:49, 30 March 2015 (UTC)

As I understand it, wounded skin can grow together where it isn't supposed to. In fact, in female genital mutilation, I believe this is used to intentionally seal the labia shut. StuRat (talk) 06:02, 30 March 2015 (UTC)

It's also used in surgery when you want to cover an area with new skin, see Flap (surgery). Especially interesting in this context is the distant flap or Walking-stalk skin flap where skin from one part of the body is attached to another part of the body while also attached to the original part. Here's an old drawing as an example. You can find photos as well but they are rather disturbing. Sjö (talk) 06:32, 30 March 2015 (UTC)

Graftings like that are done "side to side" so to speak, where the two skin layers have the same orientation, like pulling together the opposite sides of a wound and stitching them together. Under normal circumstances if you had a scab on your thumbtip and fingertip and pinched them together, they would simply heal normally. μηδείς (talk) 18:16, 30 March 2015 (UTC)

You're speaking as though from authority. How do you know this to be true?

Are you aware of some known principal in medicine that you forgot to link? Or of a case where the experiment has been tried?

StuRat's horrifying example reference seems to show at least one example where two pieces of flesh that should not be directly merged can heal together. What reference makes you so sure it couldn't happen to fingers? APL (talk) 01:45, 1 April 2015 (UTC)

StuRat's example doesn't contradict my claim, in his example (of which I was already aware) the graft to the nose was still made in the side to side fashion, with the basal dermis from the arm adjoining (not facing) the basal dermis of the nose, and the epidermis of the skin from the arm next to the epidermis of the skin of the nose. It's gruesome because in order to do this they have to cut a flap away from the arm, not just touch the epidermis of the arm to the wound, as that would achieve nothing. I do actually have a bachelor's in biology, but this is junior high-school level stuff, and should be clear from the articles linked above. μηδείς (talk) 14:57, 1 April 2015 (UTC)

That was not my example. Mine was female genital mutilation. StuRat (talk) 17:26, 1 April 2015 (UTC)

Sorry, it was Sjö's example. μηδείς (talk) 18:11, 1 April 2015 (UTC)

Adhesion (medicine), for some reason, only talks about scar tissue joining internal organs together, not the skin. I'm not sure why skin is excluded there. Do they use a different term in the case of skin ? Apparently one such case is covered in skin bridge (not safe for work !) but I haven't found a general article on skin adhesions in Wikipedia. StuRat (talk) 17:43, 1 April 2015 (UTC)