Science desk
< June 8	<< May \| June \| Jul >>	June 10 >

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.

June 9[edit]

Prevnar vaccine[edit]

Is prevnar equally effective in India?Does it make sense to give prevnar to an infant in india, as the cost here is quite something. —Preceding unsigned comment added by 203.112.84.138 (talk) 09:35, 9 June 2008 (UTC)[reply]

The concern here is whether Prevnar, a pneumococcal conjugate vaccine available since 2000 in the U.S., and recently (2006) introduced in India, (see here) is effective, since it was developed to protect against the seven serotypes of pneumococcus that are most prevalent in the U.S.

Prevnar protects against serotypes 4, 6, 9, 14, 18, 19, 23, which cause 80-90% of disease in young children in the U.S. In Europe, which has a significantly lower incidence of invasive pneumococcal disease than the U.S., these 7 serovars account for only about 70-80% of that disease. In India, the most common serotypes in children under 5 years were 6, 1, 19, 14, 4, 5, 45, 12, and 7, in that order. [1] So Prevnar would protect against 4 of the 5 most common Indian serotypes, but would not protect against 1 and 5, which are more common in developing countries, and together make up 29% of Indian isolates. Clearly, if the vaccine had been formulated primarily for Indian use, it would have included these serovars rather than 18 and 23; and equally clearly, the vaccine protects against serovars that cause significant amounts of disease in India. An article in Indian Pediatrics notes that 25% of all child deaths in India are from pneumonia, and estimates that 30-40% of these are from pneumococcal pneumonia, meaning that between 123,000 and 164,000 children under the age of 5 die each year in India of pneumococcal pneumonia. Vaccines with either ten or thirteen serotypes, including 1 and 5, are likely to be available in 2010. India meets the WHO’s criteria for countries where pneumococcal vaccination should be a priority for introduction. The risks and benefits in any particular case must be decided in consultation between physician and patient. Since the concern here seems to be financial risk: The cost in 2006 was Rs 3750 per dose plus taxes, and was not covered under the extended programme for immunisation in India. If it chose to, the Indian government could obtain the vaccine at a cost of between 15 and 30 cents (U.S.) per dose. [2]. The editorial cited asks the Indian Academy of Pediatrics to urge the government to develop a process and timeline for introducing pneumococcal vaccination.

- Nunh-huh 20:18, 9 June 2008 (UTC)[reply]

Hmm, the question is posed as asking whether administering a vaccine is advisable. Isn't that medical advice? With all due respect to the responder, shouldn't this post simply be removed? Franamax (talk) 06:35, 10 June 2008 (UTC)[reply]

A request for information is not a request for advice, even if one can imagine that that information may ultimately be used in making a medical decision. No advice has been asked for or offered. The main distinctions between the referenced section in our Prevnar article is that the answer here is a bit more detailed, accurate, up-to-date, world-centric, and referenced than it is there. It's hardly censorable. A medical advice request would have been: "Should I give my baby Prevnar?". That wasn't asked. What was asked is "Is Prevnar effective at preventing disease in Indian babies?" - Nunh-huh 07:16, 10 June 2008 (UTC)[reply]

I'm normally a medical advice czar, but would have to agree with Nunh-huh here. The response was clearly not medical advice and concentrated on things like the cost-benefit to India etc and didn't answer much on what on whether it's advisable for a person to vaccinate their baby, which would depend on many factors and clearly should not be answered on the RD for precisely that and other reasons Nil Einne (talk) 22:38, 11 June 2008 (UTC)[reply]

Tooth restoration[edit]

before one restores a tooth permanently with amalgam can one temporize with IRM till gingiva improves and better moisture control is achieved for tooth to be restored are there any guidelines for it.

Thanks tanya —Preceding unsigned comment added by Mtanya (talk • contribs) 14:16, 9 June 2008 (UTC)[reply]

Is this a homework question? If so, could I have your name so that I never visit a dentist who asks random Internet dweebs to do their homework for them? Thanks. --Sean 14:52, 9 June 2008 (UTC)[reply]

Harsh - everyone starts with no knowledge and acquires it through training/education. That they ask for information (perhaps due to laziness at homework, or out of genuine need of help) isn't an indicator of their future abilities in the dental field. Oh and re the Q - I have no idea at all, sorry. ny156uk (talk) 17:23, 9 June 2008 (UTC)[reply]

You may want to check out the wikipedia articles: Dental restoration, Temporary restoration or Dental restorative materials, specifically Indirect Restorative materials (which is what I presume you mean by IRM). Checking out the citations in these articles will surely point you in the right direction. Jdrewitt (talk) 20:48, 9 June 2008 (UTC)[reply]

In this day of eliminating mercury in the mouth, someone is still using amalgam?—Preceding unsigned comment added by Julia Rossi (talk • contribs) 07:35, June 10, 2008

Amalgam is used as standard in many places; in the UK, for example, most NHS fillings are amalgam (if anyone's lucky enough to have an NHS dentist). Amalgam has many advantages over the resin alternatives (which can be found by reading amalgam), for which reason many dentists still recommend it for some work. The main advantage of resin compounds is cosmetic; it is not as effective for restoration, as it fails much sooner, can leak, and eventually shrinks, leading to bacterial growth and continued decay; if they are not maintained and replaced regularly there is a greater risk of root canal problems. It is also less effective for restoring larger areas. In addition, it is more expensive (particularly at the clinics which tell you of the dangers of mercury amalgam and offer to replace all your fillings for you). As to the possible toxicity of mercury amalgam, the jury is still out. I've got some amalgam fillings. If I go mad because of them, I'll let you know. :) Gwinva (talk) 03:52, 11 June 2008 (UTC)[reply]

Incidentally Amalgam (dentistry) needs work. In the controversy part, it says "The most recent source[citation needed] of controversy has been from a December 1990 episode of the CBS news program 60 Minutes". I added the fact tag but the problem is obvious. Other then the fact this is uncited, it seems dubious to me that the most recent source of controversy could be conclusively said to be a 1990 episode of 60 Minutes. Especially since it's unclear how much controversy this generated internationally and the same section also says "In recent years evidence of serious toxic effects, for instance 25 studies of 5821 patients reviewed in "Effects of Amalgam Removal on Health", by Mats Hanson, plus a later study by Wojcik, Godfrey, Christie, Haley (2006)". (One would think this 2006 study generated some controversy) Nil Einne (talk)

Mercury, and cosmetic dentists with an alleged mi$$ion. I guess it's the processing which is more dangerous given that the vapour is toxic, but maybe in its set state, not the same problem (as testified to by Gwinva's erudition : ). In the mercury article there's a more recent ref to controversy – activity re bans in Norway 2007-2008 and needs references. Julia Rossi (talk) 23:46, 11 June 2008 (UTC)[reply]

Psychological concept of your perception of others[edit]

I vaguely remember a psychological/philosophical concept from the anime Neon Genesis Evangelion, which was along the lines of your perception of other people - their personality, appearance, your understanding of their motives and such, essentially the version of that person which you hold in your mind, which stems from your memories and previous encounters with this person - could be considered, philosophically speaking, as valid a description of them as that person's actual existing self. Does this concept have its roots in any psychological theory? Thanks. --Sum0 (talk) 20:05, 9 June 2008 (UTC)[reply]

That sounds like philosophy, not psychology. I don't see any psychological about that. --Tango (talk) 21:38, 9 June 2008 (UTC)[reply]

It's not quite what you say but "projection" could come into it if it means your perceptions are actually subjective. Closer to it is the empathy phenomenon. Julia Rossi (talk) 07:31, 10 June 2008 (UTC)[reply]

I think the term you are looking for is representation, although the term is pretty general and can be applied much more broadly than your use, and our article doesn't give you much anyway. You may also want to look at identity; although this is about how we see ourselves and not others, understanding how you form notions of your own identity will help you understand how you judge and represent those around you to yourself. --Shaggorama (talk) 22:40, 15 June 2008 (UTC)[reply]

Enzymes that remove pet urine odor[edit]

I understand that certain "enzymes" can break down pet urine in carpets. Something about the enzymes consuming the bacteria. Supposedly the urine smell occurs as bacteria consume the urine. Enzymes are said to kill and or neutralize this activity and reduce or eliminate odor. My question is what exactly are the names of these enzymes ? _____ase I want to know so I can be sure the product I purchase will actually do the job. Thank You, 70.118.255.25 (talk) 23:33, 9 June 2008 (UTC)[reply]

I don't think your theory is correct. There are very few bacteria in urine, as it is both sterile initially and somewhat antiseptic. The smell is simply ammonia. Any chemical which reacts with ammonia to break it down into odorless components would work to control the odor. Since ammonia isn't a protein, it doesn't require an enzyme to break it down. 67.38.24.177 (talk) 03:08, 10 June 2008 (UTC)[reply]

I don't have a specific answer for the OP, but I want to address a couple of misconceptions in the answer above. First, there's normally very little ammonia in urine; instead, nitrogen is excreted as urea. Thus, fresh urine has very little odor. Certain bacteria produce urease, which will "split" urea and can produce ammonia as a by-product. I suppose it is possible to inhibit the ureases. Second, as this suggests, enzymes act on many molecules other than proteins.Scray (talk) 03:29, 10 June 2008 (UTC)[reply]

OP is right as least inasmuch as there is a product that digests or absorbs or renders inaccessible the nitrogen in cat-pee that bacteria feed on. They had to spray a bunch of it when I moved in a year ago - and she was such a nice girl who never even owned a cat, too. I'll try to ask one of the maintenance people next couple of days, but by all accounts, such a theory and product does exist. Franamax (talk) 06:13, 10 June 2008 (UTC)[reply]

Googling "pet urine odor" shows lots of (lame) home-remedies and several commercial products using enzymes. We can't recommend a single product, and you will really never get any single name of some particular enzyme that is the "right" one. They are all commercial products, you need to read the descriptions and customer reviews on various websites and figure it out. Reading through the links, there are two or three that I would try. If I can find out the particular product used for my case, I'll post it here. Franamax (talk) 06:30, 10 June 2008 (UTC)[reply]

The only practical information I would like to add; from having multiple dogs and cats peee in the house over many years. Be sure to never use any products with AMMONIA because it will enhance the animal(s) to want to add their urine to the situation. Male dogs and cats do their normal marking and cleaning with AMMONIA or ammmonia based products is marking the spot.