:<code>...The water loss per square centimeter of each leaf in one hour (t/c<sup>2</sup>) will be the standard for the measurement. The transpiration rate for both leaves (pineapple and oak) will be taken from a one-centimeter-wide square cut from each leaf...</code>
I don't have the time, resources, or inclination to find this out myself. Does anybody have a clue as to the quantitative value of the water loss per square centimeter for oak and pineapple? If you don't have it for oak and pineapple, I just want a temperate/polar plant and a tropical/humid-area plant. The one who answers my query will receive something nice in return.~ '''<font color="CC0000">[[User:Flameviper|Flame]]</font><font color="009900">[[User talk:Flameviper|vip]]</font><font color="00CC00">[[User:Flameviper/edits|e]]</font><font color="009900">[[User talk:Flameviper|r]]</font>''' 00:39, 13 June 2007 (UTC)
I took this picture while visiting the Back Bay in Newport Beach, CA. What kind of lizard is it? I looked around, and it doesn't seem very common. If someone recognizes it or can find out what kind of lizard it is, it would be very helpful. Thanks!
nd201000:52, 10 June 2007 (UTC)[reply]
Is it possible for an HIV infected male to conceive with a non-infected female and have neither the mother nor the baby become HIV positive? Is there ANY known medical procedure that would prevent this infection? So that the donor HIV+ male can conceive with his own sperm and not transmit the virus? —Preceding unsigned comment added by 71.198.234.210 (talk • contribs)
"Do not request medical or legal advice. Ask a doctor or lawyer instead." This is not something to play around with. Get medical advice up front. Edison19:54, 10 June 2007 (UTC)[reply]
I hope Edison does not mind, but I have applied strong formatting to convince the questioner to ask a doctor, instead of a group of random internet volunteers.Nimur20:01, 10 June 2007 (UTC)[reply]
Of course it's possible. Having unprotected intercourse with someone infected with HIV does not mean you will contract it. It could be transmitted on the first encounter, a later encounter, or never. The more often intercourse occurs however odds would predict the more likely infection will occur. So it is very possible that the scenario you raise could occur. A baby will only be infected from the mother, so unless the mother becomes infected the baby will not either (and the mother being infected does not guarantee the baby will become infected either, the risk is only 25% for a natural birth with no drug treatments used, according to the article). Try reading this on HIV transmission. I'd say in vitro fertilisation could be pretty successfully used to prevent transmission, given HIV is not carried in the DNA, the virus is passed by fluid exchange. --jjron11:27, 10 June 2007 (UTC)[reply]
Well, according to Fertility a woman under the age of 30 has a 75% chance of getting pregnant after a year of unprotected sex (the odds drop dramatically if she's older than that). If one were being smart about this - you'd only have unprotected sex when she's ovulating - since she won't get pregnant at other times. There are all sorts of ways to try to detect when she's ovulating and it would be very smart to time unprotected sex to match the correct time in her 28 day cycle. So there are just 13 times per year (every 28 days) when it's worth trying. Perhaps 26 well times unprotected attempts will give her a 75% change of he becoming pregnant. The page on HIV says that for unprotected 'normal' sex, there is a one in one thousand chance of passing on the virus through unprotected sex - that sounds small - but over a lot of tries - those odds increase alarmingly. So over (say) 26 attempts in one year - the odds of 'getting away with it' are 0.999 raised to the power 26 - which is 0.974 - so, if you were really, really careful and did things just right - then there would be about a 3% chance (1 in 33) of passing the disease on to the woman for a 75% chance of getting her pregnant. If she did get the disease then there is a 25% chance that the child will catch it from her during childbirth. However, I very much doubt that you'd catch her ovulation cycles just right - so in all likelyhood, her chances of getting pregnant would be much less than 75%. If you just risked unprotected sex all the time to increase the chances of her getting pregnant - then her odds of catching the disease after a year would go up hugely. Overall, the risk seems awfully high to me - I most definitely wouldn't want that kind of risk. Please seek medical advice - there has to be a better way. SteveBaker14:02, 10 June 2007 (UTC)[reply]
I've heard of a sperm washing technique that can be used on the sperm of an infected male. This sepperates the virus from the rest of the semen and thus the sperm can be used for IVF. I've heard some couples have tried this and were succesful. Others however got sick of having to wait for a succesful treatment and tried it the natural way . I don't know if in these cases the women got infected. I have no direct link as reference though (and am a bit to busy to dig one up) but this website www.aidsmeds.com is a good place to look. 62.194.90.10714:18, 10 June 2007 (UTC)[reply]
UV light from halogen lamps
I always notice mention of the danger of ultraviolet light from unfiltered halogen lamps. I would tend to think this would not be a concern, because at the temperature of the filament (3200oK) the blackbody radiation spectrum contains very little UV. Compared to the sun's temperature (5800oK) the amount of UV radiation, especially burning wavelengths < 320 nm, given off at the same intensity of visible light is exceedingly miniscule. Does anyone know of actually receiving sunburn from one of these lamps, or is it just an over-cautious urban myth?
-User: Nightvid
While the blackbody spectrum at 3200 K contains relatively little UV, it's worth bearing in mind two important points. First, you're much closer to the surface of your light bulb than you are to, say, the sun. Second, the quartz envelope used to manufacture halogen bulbs is (unless specially treated) transparent to UV, unlike the glass envelope used for conventional incandescent bulbs.
This abstract from a paper that appeared in the journal Dermatology indicates that the DNA-damaging capacity of an unfiltered 50 W halogen lamp at a distance of 7 cm (about 3 inches) is roughly comparable to that of the noonday summer sun in a mid-latitude location like Michigan. They also note that "The radiation from quartz halogen light bulbs has been reported to cause erythema in humans and skin tumors in experimental animals"; erythema would be a sunburn.
The amount of damage done can be reduced through maintaining a safe distance from the bulb (the intensity of UV will fall off with the square of the distance) or by following the bulb manufacturer's directions for shielding (a layer of ordinary glass will block the bulk of the emitted UV). Some halogen bulbs incorporate a glass outer envelope or employ specially coated quartz and don't require a separate UV shield. TenOfAllTrades(talk) 17:34, 10 June 2007 (UTC)[reply]
That is correct. The titanium dioxide pigment that is the opaque white base for most paints absorbs strongly at wavelengths below about 400 nm: [1]. (Of course, even torchieres shield the bulbs; in addition to preventing UV exposure, a glass shield will also contain the dangerously hot shrapnel generated if a halogen bulb fails.) TenOfAllTrades(talk) 15:44, 11 June 2007 (UTC)[reply]
Height of land + sea level change
hi,
I'm looking for images showing what would be land/sea if sea level would rise/fall by 1, 5, 10, 100, -1, -5, -10, -100 and -120 metres. Also does anyone know of a website that has some sort of thing where you can input a sea level change and it would have some sort of animation or pic showing the whole world/ parts of it which would be exposed/ submerged?
thanks, --Wiki99977713:59, 10 June 2007 (UTC)[reply]
This page has some of that for the USA's Atlantic and Gulf coasts, but only for modest rises. Any contour map of the region of interest will show you what you want, though, since the coastline is always more or less at 0 meters above sea level (places like the Netherlands and New Orleans provide exceptions). --TotoBaggins14:55, 10 June 2007 (UTC)[reply]
This map, although not perfect, shows quite dramatically what a 120 metre fall would look like; all the areas coloured in cyan would be exposed; Russia would merge into Alaska, Australia would become linked to New Guinea, and the UK and Ireland would become land-locked nations within a much larger European landmass. Laïka15:52, 10 June 2007 (UTC)[reply]
Eh? The colour scale below that image shows that the Cyan region represents areas that all the way down to -3000 meters - so a mere -120m change wouldn't be reveal much of the cyan areas. SteveBaker16:44, 10 June 2007 (UTC)[reply]
Sorry; that caption wasn't there when I checked the page before (it just said "This page left intentionally (almost) blank", although I can't find in the edit history; very strange...); I was going by the article Continental shelf, which states that the depth of that shelf was less than 140 metres. Laïka18:23, 10 June 2007 (UTC)[reply]
An obliquely related question- if sea level rose due to global warming, would our measurements of land elevation change also? --Sturgeonman21:39, 13 June 2007 (UTC)[reply]
Discontinuous
In the article on Polymorphism (biology), polymorphism is defined as a "discontinuous variation in a single population..." What does discontinuous mean in this sentence, and in what way does it differ from a continuous variation? I checked both Wikipedia and Wictionary but didn't find a satisfying explanation. Thank you! Lova Falk14:51, 10 June 2007 (UTC)[reply]
It means that there is some characteristic that only takes discrete values, and not a continuous range of "shades" in between. In humans, for example, blood group and eye colour are polymorphic, whereas height and skin colour are not. Gandalf6115:00, 10 June 2007 (UTC)[reply]
Theists thumbing their noses at science despite the fact that they rely on it every day
Religious folk don't like science, generally because it goes a long way towards casting doubt on their beliefs. And because of that, they like to denounce it, call it "bunk" etc, especially regarding evolution. And yet this is hypocritical, because they rely on science every day to power their cities and run their cars.
^^^Whether you agree with this statement or not, I could REALLY do with a quote that backs it up. Preferably from the most reputable source possible. I need to stick it in an essay and I have Googled and Googled but just can't find anything.
I took a look at my big compilation of atheist quotes but couldn't find anything exactly on point. Here's the closest I found:
"Where it is a duty to worship the sun it is pretty sure to be a crime to examine the laws of heat." ~John Morle~
“Men think epilepsy divine, merely because they do not understand it. But if they called everything divine which they do not understand, why, there would be no end of divine things.” ~Hippocrates~
"Truth does not demand belief. Scientists do not join hands every Sunday, singing, 'Yes, gravity is real! I will have faith! I will be strong! I believe in my heart that what goes up, up, up must come down, down, down. Amen!' If they did, we would think they were pretty insecure about it." ~Dan Barker~
Why do scientists thumb their nose at theism when they rely on Him every day... :D But seriously, all you're doing is proselytizing the religion of science, let theists be. --frotht17:09, 10 June 2007 (UTC)[reply]
I like Carl Sagan's quip, "We live in a society exquisitely dependent on science and technology, in which hardly anyone knows anything about science and technology." But you should realize that there is a difference between science and technology. Religious folk depend on technology more often than they depend on science. Though science and technology are related, they are not the same thing. Hypothetically, a Wankel engine might have been invented through prayer, trial-and-error, and total lack of thermodynamics understanding. Nimur20:05, 10 June 2007 (UTC)[reply]
Which leads me to a full discussion of what science actually is. Trial-and-error, which leads to practical results, seems like a prototype of the scientific method anyway. Eventually, after enough trials, many of the underlying principles must become clearly evident, regardless of what the starting beliefs are. For this reason, I have no worries about the incessant debate between theists and scientists. In the end, truth will come through experiment. This is of course penchant on the definition of "truth" or "existence." As a scientist, I tend to equate existence with experimental verifiability. Religious scholars do not always agree with me. But they are so wrong. Nimur20:12, 10 June 2007 (UTC)[reply]
But that's the point of debate- you believe truth will come through experiment, and basically everyone can agree that has meaning and value (if repeating an action 1000 times produces the same exact reaction then the statement "action causes reaction" is a valuable, true statement), but there are meaningful statements that are not scientifically verifiable and there experiment fails and religion/philosophy begins. That's Kant I think btw. --frotht05:18, 11 June 2007 (UTC)[reply]
Science is a lot more than trial and error. There is a great little math example that shows why just trying something until it seems to work isn't the scientific way. Take a piece of paper and follow along with me:
Draw a circle, put a dot somewhere on the circumpherence - the circle contains one 'region'.
Add a second dot on the circumpherence (it can go anywhere - but it's easier to draw if you space the dots out widely) - connect the two dots with a line - you now have two regions.
Add a third dot somewhere on the perimeter of the circle and connect it to both the first and second - and now you have four regions. 1,2,4... See a pattern?
OK so let's add a fourth dot - connect it to all of the previous dots (you should be looking at a circle with a quadrilateral inside - with both of it's diagonals drawn in). Count them up - now you have eight regions...oh, yeah - I see a rule emerging. 1,2,4,8... It seems like every time you add a dot, it doubles the number of regions!
Let's check that - I got 8 with four dots - so if I add a fifth, I should get 16 regions. So, go ahead, add a fifth dot - connect it to all of the others (you should have a 5 pointed star inside a pentagon inside a circle...resist the temptation to place a candle at each corner and summon a deamon!)...Wow! I got 16 regions! 1,2,4,8,16... I can write an equation for this! I think I'm getting the idea of this math stuff!
Now if you stopped and wrote that the number of regions ('R') for 'N' dots is: R=2(N-1) - then you just showed the difference between trial and error and math and science. You didn't understand WHY that happened. So now, add a sixth dot and connect it up every way you can to the others - you'll find that you don't get 32 regions as you might have expected - you only get 30 (if your points are spaced evenly around the edge) or 31(if they weren't exactly equally spaced) - no matter what, you can't make the expected 32 regions! Urgh! 1,2,4,8,16,31?! The universe hates me! So this seemingly great rule that we 'discovered' by repeated trials isn't a rule at all - it just looked that way for a while. This kind of thing is everywhere - you never know how many trials you have to make in order to be sure that you have explored all of the phenomena. How do you ever know that you've done enough trials? The answer is that you have to have a hypothesis - you have to have a theory that you're trying to prove or disprove. You have to know why the experiment worked - or failed. The experimental technique of science is there to try to verify theories...that's a lot different from trial and error. SteveBaker13:38, 11 June 2007 (UTC)[reply]
Certainly classical mechanics is not in any way provable- by observing a system you can predict its behavior but there's no reason for gravity to suddenly become repulsive other than that it hasn't happened yet, and no reason for the laws of thermodynamics to be infallable other than that they have never failed yet. Mathematics is obviously provable since it's all a big made-up system based on logic (probably logic specific to our minds) and it "works" by definition. When you extend classical mechanics with mathematics into quantum mechanics and all that other modern yuck that's probably not even accurate let alone provable, it still retains the uncertainty of classical mechanics. And I believe that spreads to all other forms of science as well, at least where the utterly infallable King Math isn't too involved. And in any case, on a much lower level, all we really know is colored streaks passing through our visual field and tingly sensations from our fingers, etc. If we observe patterns and make predictions that's nice but there's no making sure statements about them.Skeptical_hypothesis, Philosophical_skepticism#Motivations_for_external_world_skepticism, and all that you know. --frotht23:47, 11 June 2007 (UTC)[reply]
Good example, SteveBaker. I'm not trying to call the scientific method "trial and error" - I'm suggesting that if you start by simple trial-error methods, you will eventually develop a full-blown scientific method as the natural end result. Theory emerges from experiment. Nimur17:32, 11 June 2007 (UTC)[reply]
Really a beautiful example. But that means, physics is no science, if it's true what they say about how a physicist proves that all odd numbers are prime:
If the first statement was about race instead of science, people would see how ignorant it is. Religious people are not against science. The Catholic church is one of the largest contributors to astronomy in the world and run a number of observatories. It's pretty obvious that those that don't understand religion, understand science even less. --Tbeatty20:58, 10 June 2007 (UTC)[reply]
Race and religion are different. People choose their religion, nobody chooses their race (or gender, or sexuality, or height, or date of birth...) It's not ok to judge based on race, but it is ok to challenge beliefs.
Also, note that "60 percent of professors in [the] natural and social science disciplines describe themselves as either atheist or religiously agnostic. In comparison, among those in the general U.S. population, about 3 percent claim to be atheists and about 5 percent are religiously agnostic." [2] It's very ignorant of the truth to say that religious people are more prone to understand science. Lastly, read up on Galileo Galilei if you're so proud of the Catholic Church's stance on Science.
People do choose their ignorance and that statement on religion was ignorant. Also, I believe your 60% stat, if it's even true, goes way down when you only include the physical sciences. Social sciences are notoriously anti-religious but have little bearing on hard science disciplines. And I don't think sciences track record was any better during the time of Galileo than religion. Both have grown and both have had their ignorance. --Tbeatty22:28, 10 June 2007 (UTC)[reply]
That's not untrue, but I believe they give more consideration to the effect on their lifestyle than to the level of technology. So for example, cell phones can be OK as long as they're used in a prescribed way that doesn't interrupt life at home. They avoid a modern way of life, but not necessarily all modern technology. --Reuben04:41, 11 June 2007 (UTC)[reply]
If you'd like a quote against it you could look at the writings of William Jennings Bryan, who makes it quite clear that he had no problems with technology and much of modern science but that he thinks that evolution is really more ideology than science. I'd be surprised if that is far off the mark from how these people deal with that particular "paradox". Remember that the best way to make an argument is to take the strongest, and best formulated opposition to it, and try to find a way around that. If you can beat that, then you're making a good argument. If you can't, then you're just dealing with strawmen. --24.147.86.18711:53, 11 June 2007 (UTC)[reply]
Where the Bible most directly contradicts science is in the story of creation in Genesis, if taken literally. People existing on Earth within a few 24 hour days of the creation of the universe is contradicted not only by the theory of evolution, but by just about every field of science, including geology, astronomy, biology, archeology, anthropology, physics, etc. StuRat15:52, 11 June 2007 (UTC)[reply]
Don't take it literally. I'm sure you used the terms "rising sun" and "when the sun goes down", which from the point of view of science are ridiculous, taken literally. There are many scientists who believe in Genesis as part of their religion, it kinda makes sense once you stop assuming "days" are equal to our regular one-earth-revolution days. After all, the protagonist of Genesis is God... who knows how long one God-day is? Maurog08:57, 12 June 2007 (UTC)[reply]
There was day and then there was night, the end of the x day. Take it or leave it IMO, not much room for long-day theories --frotht13:52, 12 June 2007 (UTC)[reply]
Religious people are superstitious morons, whether they like it or not. That's a fact. They believe, among other nonsense, that good people will go to heaven and bad people will go to hell, that sounds so childish to me. As the literacy rate increases, religious affiliation decreases, what means that sooner or later we'll be free from them. --Taraborn20:57, 13 June 2007 (UTC)[reply]
Brain Cells
Can stem cell research help us to grow more brain cells.
Olfactory sensory neurons are the cells that transfer the signal of a "smell" from your nose to your brain. These die off every 5 or 6 weeks throughout our life and have to be replaced from stem cells, a process known as neurogenesis. There is a significant amount of research into these cells, since they provide a means for us to, as you say, "grow more brain cells." Rockpocket02:10, 11 June 2007 (UTC)[reply]
If you're thinking more brain cells = smarter, don't. Growing more brain cells, not in response to a neurological disorder that is preciptated by the die-off of neurons like Parkinson's disease, may not be necessarily a good thing... The proper development of every brain (in every animal that has a semblance of a central nervous system) includes the production of far more cells than eventually "needed" in the adult animal. The programmed die-off of specific populations, and the "trimming" of superfluous neurons as the brain orders itself is vital to the final state of the brain. There are a number of disorders (especially that result in experimental animal models with controlled mutations) in which the regulation of this process is disrupted; too many neurons provides a lot of development problems. In fact, even cell transplantation procedures in Parkinson's patients can have this effect: they may trade the symptoms of the disease caused by a massive loss of dopaminergic neurons of the substantia nigra for dyskinesia caused by, essentially, neuronal hyperactivity in the region.
In response to the original question: eventually stem cell research should provide a means of reliably creating differentiated neurons from muilt- or totipotent cell lines. Should. — Scientizzle05:22, 11 June 2007 (UTC)[reply]
So if someone wanted to reshape their brain to make themselves cleverer, have a better memory, be able to work stuff out faster, what would they have to do?
The best is to probably spend free time reading and doing mental excercises. A little Mozart might help. Practice makes the most difference, you know, whether its playing football or solving calculus problems... — Scientizzle19:06, 11 June 2007 (UTC)[reply]
Yep - there are no shortcuts - the more you use your brain, the more you can use your brain. Play chess, listen to classical music, do math problems, write poetry, learn quantum physics, learn to play the piano. My biggest mental workout is researching answers to questions on the help desk. SteveBaker03:51, 12 June 2007 (UTC)[reply]
Genetic Mapping
Here it says; "Chiasma counts in human male meiosis show an average of 49 crossovers per cell (Morton et al., 1982). Since each crossover gives 50% recombinants, the chiasma count implies a total male genetic map length of 2450 cM. The current version of the Location Database (Collins et al., 1996) suggests a total male map length of 2851 cM. Chiasmata are more frequent in female meiosis (exemplifying Haldane's rule that the heterogametic sex has the lower chiasma count), and the total female map length in the Location Database is 4296 cM (excluding the X). Thus over the 3000 Mb autosomal genome, 1 male cM averages 1.05 Mb and 1 female cM averages 0.70 Mb; the sexaveraged figure is 1 cM = 0.88 Mb."
The quote is from here. That source explains it fairly well, so I'm not sure which part you find confusing – can you be more specific? Look at its Fig. 11.2(A) when you read the text:
Consider a person who is heterozygous at two loci [A and B], and so types as A1A2 B1B2. Suppose the alleles A1 and B1 in this person came from one parent, and A2 and B2 from the other. Any of that person's children who inherit one of these parental combinations (A1B1 or A2B2) is nonrecombinant, whereas children who inherit A1B2 or A2B1 are recombinant (Figure 11.1). The proportion of children who are recombinant is the recombination fraction between the two loci A and B.
[...] If the loci are syntenic, that is if they lie on the same chromosome, then they might be expected always to segregate together, with no recombinants. However, this simple expectation ignores meiotic crossovers. During prophase of meiosis I, pairs of homologous chromosomes synapse and exchange segments (Figure 2.14). Only two of the four chromatids are involved in any particular crossover. A crossover, if it occurs between the positions of the two loci, will create two recombinant chromatids carrying A1B2 and A2B1, and leave the two noninvolved chromatids nonrecombinant. Thus one crossover generates 50% recombinants between loci flanking it.
The argument in the rest of your quote is as follows: One centiMorgan (cM) is defined as the genetic distance between two loci that causes there to be a 1% chance of a recombination event between these loci. Thus the average number of recombination events is 0.01 per cM of DNA length. The average total number of crossovers in a male cell is quoted as 49, but according to the above each crosssover has only 50% probability of generating a recombination event in a particular chromatid, so the average number of recombination events is only 49*50% = 24.5. Thus they calculate a naive estimate of the "genetic map length" of the whole male genome to be 24.5/0.01 = 2450 cM. --mglg(talk)22:41, 10 June 2007 (UTC)[reply]
Okay, I understand it now; thanks! But now I have another question. If two loci are one cM apart, does that mean that recombination occurs in 1% of all mieoses and therefore presents in 0.5% of individuals or that it occurs in 1% of individuals and occurs 2% of all mieoses? --83.84.74.2818:44, 12 June 2007 (UTC)[reply]
My understanding (which is purely from your source) is that 2% of all meioses will have a crossover between the loci, and 1% of the resulting gametes will contain a recombination between the loci. To qoute: "Two loci that show 1% recombination are defined as being 1 centimorgan (cM) apart on a genetic map." --mglg(talk)19:38, 12 June 2007 (UTC)[reply]
"Sweating out toxins"
I keep hearing that sweating removes toxins from your body. For some reason, it sounds like nonesense to me, since I'm pretty sure that that's what the liver is for.
Someone on Wikipedia even says as much; from Sauna:
"Steambaths and saunas induce perspiring to provide a comprehensive cleansing of the skin and sweat glands. Skin is the largest organ in the body. 30% of body wastes are passed through the skin. Profuse sweating enhances the detoxifying capacity of the skin by opening pores and flushing impurities from the body."
No toxins, alcohol, or foreign substances are excreted in sweat in enough volume to make a difference to body concentrations. Quackery pure and simple. Take no health advice and do not pay a dollar for any health-related services to anyone who claims this. alteripse00:19, 11 June 2007 (UTC)[reply]
Sweat is certainly one way in which some toxins are excreted, but the amount pales in comparison to the work of the kidneys & liver. Here's an interesting link. The sweat glands are not filtering organs. What comes out is essentially what's in the blood, modestly concentrated by the controlled reuptake of water. One thing that's important to note: inducing excessive sweating to remove alcohol or other toxins could make things worse by causing dehydration. That "30% of body wastes are passed through the skin" sounds like a steaming load to me...I'll have to check that out. — Scientizzle00:40, 11 June 2007 (UTC)[reply]
Isn't the composition of urine and sweat about 97 or 99% identical? Surely there's some waste excreted with sweat, but it couldn't possibly be as efficient as urinating. --Wirbelwindヴィルヴェルヴィント (talk) 02:24, 11 June 2007 (UTC)[reply]
So, the guy I used to flat-share with who'd cocoon his thighs and midriff with cling film before he went to work in the morning in order to sweat the booze out was just wrapping himself in plastic for no good reason? Hehehe. --Kurt Shaped Box09:42, 11 June 2007 (UTC)[reply]
Perhaps if you included sloughed skin cells, hair, and sebum, the portion of human waste material leaving via the skin might be brought closer to 30%. Vranak
That's a possibility if you're considering all possible waste that could possibly leave via the skin. Definitely. (Although if you include CO2 as "waste", that number would drop considerably. Including H2O as waste makes it more confusing and environment-dependent.) But there's just no way that 30% of metabolic waste (which would include most "toxins", something dead skin cells generally aren't considered) is excreted in sweat (in humans). I guess the context of the quote needs to be properly framed and clarified, to say the least.
I took a cursory look at PubMed to see if there was much acadmemic literature on sweating out toxin and came up fairly empty...I'll keep looking. — Scientizzle18:45, 11 June 2007 (UTC)[reply]
If you consider salt to be "waste", then a substantial amount of waste is in sweat. If you don't, then only minor quantities of other substances are present. Since most people consume way more salt than they need, it isn't unreasonable to consider it to be waste to be disposed of, I suppose. StuRat04:06, 11 June 2007 (UTC)[reply]
Is there anything that my doctor can proscribe me...
Is there anything that my doctor can proscribe me that can increase the volume and potency of my semen ejaculations, as well as reduce the recharge time between ejaculations of semen?
Actually, I work in a hospital. It is general knowledge (no citation needed) that "If you (insert an action here) more often, your body will adapt to allow you to (insert same action here) more often." So, if you run more often, you body will adapt to allow to run more often. If you sleep more often, your body will adapt to allow you to sleep more often. If you eat more often, your body will adapt to allow you to eat more often. If you smoke crack more often, your body will adapt to allow you to smoke crack more often (until you die of course). --Kainaw(talk)15:13, 12 June 2007 (UTC)[reply]
If you are concerned about the volume or potency of your ejaculations, see your doctor, or seek a referral to a qualified specialist. The Ref Desk isn't qualified to answer your question, and we're not an appropriate venue for providing medical advice. TenOfAllTrades(talk) 14:37, 11 June 2007 (UTC)[reply]
As others have said, rather then asking us what your doctor may be able to do, ask him/her. But medical issues aside, I have to question why you want to increase the volume and recharge time of your semen ejaculations. If you and your partner and trying to get pregnant, what matters is your sperm count and quality. I don't know for sure, but I strongly suspect you could easily increase the volume of your semen ejaculation yet reduce the sperm count (perhaps effectively maintaining the number of sperm released per ejaculation). In any case, if you have fertility concerns, you and your partner should see a professional help rather then trying random stuff which may be just making things worse. (This will also help to determine if there is a problem and if there is, what's causing it) If you concerns are not fertility related and presuming your not trying to be a porn star, then I suggest you at least speak to your partner/s first. You'll likely find that they may not be particularly interested in the volume of your ejaculations and indeed may even prefer smaller ejaculations since it's less messy. You'll probably find you and your partner/s can have a more enjoyable experience by being more creative and worrying less about the volume of your ejaculation. In any case, although this is OT, I would hope you've both/all taken adequet precautions including being tested for STDs before engaging in unprotected sex. Of course, in the end what you do is up to you. Nil Einne17:12, 11 June 2007 (UTC)[reply]
Hehehe. I was just deciding whether to mention asparagus or not (at risk of being kicked about by the 'no stuff you heard somewhere' people). I thought that the discussion was familiar. --Kurt Shaped Box01:41, 12 June 2007 (UTC)[reply]
I. Maniraptora
A. Ornitholestes
B. Deinonychus
1. Archaeopteryx
2. modern birds?
Thanks, anon.
Hi there. You might want to post future questions here, but in the meantime I've taken the liberty of forwarding your question there. Check on the talk page there & you'll probably get an answer sooner or later. Cheers, Spawn Man11:19, 11 June 2007 (UTC)[reply]
The big cladogram they have up at the most awesome museum ever (I'm not biased or anything ;) ) is 15 years old now and a little out of date, but from what I can tell that part is correct, except it leaves a lot of stuff out (for example, oviraptors are also maniraptorans, and are more closely related to Deinonychus and birds than to Ornitholestes, and Ornitholestes' classification as a maniraptor is still a little controversial. See the article on Maniraptora for a more complete, up to date family tree. Dinoguy215:25, 11 June 2007 (UTC)[reply]
June 11
Gliese 581c
I've been wondering about this for a while. Does anyone have a rough estimate of the probability of life on Gliese 581c? Thanks in advance! Gbgg8900:54, 11 June 2007 (UTC)[reply]
No one really has any idea, because we only have one data point in the universe for life, namely our planet; extraterrestrial life could potentially bear little resemblance to our own. That being said, that chance that Earth-like life (say, carbon-based with water as the solvent for chemical reactions) existing on Gliese 581 c is very, very small, because estimates for the temperature on the planet didn't account for its atmosphere (which is unknown). Very likely the planet looks more like Venus than Earth, making it far too hot for life. zafiroblue05 | Talk01:51, 11 June 2007 (UTC)[reply]
It's really impossible to know - we could perhaps say for sure that "life as we know it" (carbon/water) is impossible because of some temperature or radiation problem on the surface - but that's about the limit of what we could say - and even then we're on shakey ground.
What about underground where life might be shielded from radiation - or at the poles where it might be cool enough?
Are there perhaps strategies that extremophiles may have developed that we havn't thought of yet?
What about life as we don't know it? Life based around other chemistry is something that science fiction talks a lot about - but there is little doubt that the complex chemistry required strongly favors carbon/water life forms - but that doesn't necessarily make life based around exotic systems of chemistry impossible.
Life as we don't know it might be self-reproducing data with no chemical basis - something like patterns in sand dunes that maintain their shape, split in two, consume other patterns in order to retain their shape? Something weird like that might be classifiable as life yet have no specific material existance.
What about intelligent life that developed elsewhere and travelled to that world where they live in highly protected artificial environments?
I came upon this question in a search and realized this would help. Some Albedo/Emissivity combinations (extremes) are unrealistic.
=((((R^2)*σ*(Te^4)*(1-A))/(4*ε*(d±(d*e))^2))^0.25)-273.15 24.78.167.139 (talk) 17:34, 30 May 2010 (UTC)[reply]
Glass
Can some one tell me the process for making glass? I also want to know the historical origin of glass. —The preceding unsigned comment was added by 196.200.102.42 (talk • contribs).
You might start with the articles on Glass and Glassblowing (which contains a brief description of the process of making molten glass, and a description of one method of shaping it). You can find even more articles by using the search box on the left column of your window. Come back if you have more questions. --TeaDrinker07:14, 11 June 2007 (UTC)[reply]
I'm about to embark on a series of rewrites involving animal anatomy & would love to have a partner in crime. This would involve polishing any articles that I've rewritten or expanded to make sure I haven't made any mistakes & to add anything I've missed. The said person must have fairly good knowledge on anatomy in animals in order to make up for my shocking knowledge of the subject ;). Anyway, more than one person would be great, and I'm going to start in the next week or so. Work doesn't need to be finished straight away, but a collaborative effort needs to be kept up. If you're up for it, leave me a message on my talk page or here & I'll send you the article links when I'm done with them. alas, no rewards available this time round. Cheers, :) Spawn Man09:46, 11 June 2007 (UTC)[reply]
What is a shaft passer?
I had read somewhere that it allows a shaft of a gear or a wheel to pass through the spokes of another wheel. Wikipedia doesn't seem to have an article on this. No joy on Google either -- WikiCheng | Talk11:57, 11 June 2007 (UTC)[reply]
It was invented by the Germans during the war to keep the British minesweepers from catching the cables that held the German mines floating under the sea at a certain depth. With these "shaft passers," the German cables could allow the British cables to pass through as if they were going through a revolving door.
Response 2:
It is actually a Russian WW1 invention as far as I'm aware. Think of it as two cog wheels built into the mine's mooring rope. The two wheels are connected by metal spokes that rotate with the wheels and alternatingly engage and disengage on locking mechanisms fitted on to the opposing wheel's axle, so that one spoke at least (in fact a pair - to the left and right of the wheel), always keeps the connection between the mooring ropes. Now, when the sweep wire rides up on the mooring rope, it encounters the two cog wheels. The cogs transport the wire over the wheels. As the spokes on the forward side disengage, the ones that come behind the wire engage and thus maintain the connection. That's it. I'll chase a drawing if you wish.
That's where I heard about a "shaft passer", too—and it's the only place. I've tried just about every clever Google search I can think of since then, and I'm coming to the conclusion that our search for a 'shaft passer' may well demonstrate that Feynman was either the victim or perpetrator of yet another clever practical joke.
Just a couple weeks ago I saw a device on a man-safety line that allowed a carabiner to pass by the connection points that anchored the line to the fixed stanchions supporting the line. The application was at a canal lock, the line was attached to a wall that ran alongside the lock horizontally for a hundred feet or so, and the lock workers wore harnesses that had a lead which they clipped to one of these devices on safety line, to prevent them falling into the lock if they got too close to the edge. I suspect someone more familiar with climbing gear, or industrial safety gear has seen and/or used these things... I tried to figure out how it worked (I could see it, but not get closer than a couple of feet). It appeared to be very similar to the device described above with two cogs, and spokes. As the lock worker walked along the wall, the device would come across a place where the line was anchored to the wall with an eye bolt, and the device would travel over the eye bolt without disengaging from the safety line. Would that device be considered a "shaft passer" ? Is there another commonly-used term for it?
I suppose it is the same mechanism, used for a different purpose. It looks like there was an article (or a yet-to-be-created article) in Wikipedia on shaft passer sometime back. There is a mention of protecting the page here. Thanks to all of you for trying to enlighten me but I still haven't got beyond having a hazy idea of what a shaft passer is. But I am convinced that there is something. Please have a look at [5] too. I have a feeling that it is also referred to as an 'avoider'. -- WikiCheng | Talk04:59, 12 June 2007 (UTC)[reply]
First, WikiCheng, sorry for telling you what you already knew when it came to SYJMF.
Second, 71.112.132.210, that mention of a "passer" for carabiners and a fixed safety line is interesting. It's an easier problem, though, as what we have there is a device that's normally attached to a line. By attaching it at two adjacent points, and allowing one attachment at a time to be temporarily disconnected, an obstruction can be easily passed. (Furthermore, in the case of the safety equipment, there's not normally much force on it, as long as the worker is not in the process of falling.) But what we're talking about wrt a "shaft passer" is a device that can allow two normally-disconnected shafts or lines to pass each other without interference, and moreover while they're both potentially under significant tension (or compression).
Finally, if anyone's still not visualizing what the hypothetical shaft passer would do, take a look at the picture at the right, and imagine that one of the shafts supporting one of the auxiliary gears were routed through one of the spoke holes of the large gear in the middle. Obviously the mechanism wouldn't work very well, because as the large gear rotated, it would hit the intruding shaft, either breaking something or jamming the machinery. But if there were some magical mechanism in the middle of each of the (in this case four) spokes which could open, one at a time, to allow the shaft to pass as the large gear turned...
You might be able to do it with strong magnets. Basically take two bar magnets and stick them on their sides to the ends of the shaft you want "passed through" the gear. As one shaft turns the other will turn so that the magnets are parallel with each other and the opposite poles across from each other. Of course the turning shaft would have to have relatively little resistance on either side compared to the strength of the magnets for this to work. Sifakatalk22:35, 12 June 2007 (UTC)[reply]
Thanks a lot Ilmari! Thank you very much ! As you mentioned, it feels almost obvious. If I draw this (copy it from the picture you provided), is it good enough (legal) to be put in Wikipedia? -- WikiCheng | Talk05:40, 13 June 2007 (UTC)[reply]
Redrawing a copy of the illustration would be a copyright violation. However, drawing an original picture of the mechanism — from a different angle for example — based on the information given in the illustration should be OK. —Ilmari Karonen (talk) 19:56, 13 June 2007 (UTC)[reply]
IMPORTANT!. Shaft passers exist.. Not a wild goose chase. Simply place cogs (free to rotate) on the passed shaft - then use a cog on certain shaft and cogs on inner rim of outer wheel - this works - see original question "allows a shaft of a gear or a wheel to pass through the spokes of another wheel" -
Hypothetical Runaway Greenhouse effect
I was reading Greenhouse effect and also Venus and got to thinking. If life had not evolved (or created, depending on viewpoint), would the greenhouse effect escalate to the point of venus? This is assuming that the sun is stable, and has an infite supply of hydrogen to continue on it's Main sequence indefinately, no intervention from comets, ateroids, alien life, supernovae, etc. My assumption is that the atmosphere would eventually look like Venus based on so far what I've read. With constant heat from the sun, the earth radiates pretty much as much heat as it recieves from the sun, but volcanism should increase the amount of CO2 in the atmosphere, which causes the greenhouse effect. That makes the earth retain more energy then it is letting off. But is there enough CO2 escaping from the atmosphere to balance this effect?
On another note, it doesn't look like anything severe has happened to Mars yet, unless we can say the atmosphere is 95% Carbon Dioxide due to the greenhouse effect. --GTPoompt(talk)14:14, 11 June 2007 (UTC)[reply]
Don't forget the difference the distance from the Sun makes. Mars may very well need a "runaway greenhouse effect" just to keep the temp livable (for humans) at that distance from the Sun. Smaller planets, like Mars, also cool more quickly than larger planets, losing their geothermal (or equivalent) sources of heat. StuRat15:31, 11 June 2007 (UTC)[reply]
What happens (without life of any kind, including that which build machines to burn fossil fuels) is that the level of CO2 in the Earth's atmosphere is in equilibrium: Just as volcanoes transfer CO2 from the Earth to the atmosphere, so too does CO2 from the atmosphere re-combine with oxide and hydroxide minerals, converting them to carbonates and bicarbonates (a "locked up" form of CO2) and thus transferring the CO2 back from the atmosphere to the earth. This is a cyclical process, and the Earth is just far enough from the sun that this is a stable equilibrium. -User: Nightvid
Just a guess. Slow rotation and no orbital eccentricity probably contributed to the demise of liquid water. I think retaining the vast oceans on earth and the mechanism that does it is what keeps the earth in check. Keep in mind that water was the principle greenhouse gas on both planets, not CO2. On venus, the water evaporated and is gone and CO2 cocentrations went nuts (95% on venus versus 0.04% on Earth). A runaway process on earth would be oceans evaporating and adding more water the to atmosphere. CO2 may cause minor fluctuations, but to see venetian style global warming would require a water vapor driven process. This seems to be independant of life on the planet as the earth has been both warmer and colder as well as volcanic but never runaway. --Tbeatty09:54, 14 June 2007 (UTC)[reply]
A website for getting introduced to quantum mechanics
Regarding the above subject I humbly request the desk volunteers to suggest me a good website that would give somewhat elaborate introduction to quantum mechanics.
Many webpages as far as I searched the introduced quantum mechanics with birds eye view about wave function. How to use the wave function to calculate a particles position at point B if it started at point A having x momentum when such calculations involves wavefunctions having many imaginary quantities? Webpages that start dealing with wavefunction didnt deal with any numerical example as one above. And the topic gets advanced as one reads through.
Thanks.
signed 121.247.214.22615:15, 11 June 2007 (UTC)[reply]
I think they are valid content forks. I agree that the content also belongs in Wikiversity or Wikibooks, but it accords with all the WP policies, and is not a duplicate to the more technical articles. It's comparable to the situation in most United States colleges where there are separate courses for majors and non majors. YechielMan15:38, 11 June 2007 (UTC)[reply]
yes... well.... that's a dreadful precedent. If we begin to write articles for majors and non-majors, and then for highschoolers and preschoolers, they will be a nightmare to maintain. I appreciate the value of these articles, but I really think they belong on a sister-project. That's not in any way a devaluation, it's precisely why these projects were created, and hosting the articles here instead of there amounts to "brain-drain" to those projects. dab(𒁳)16:34, 11 June 2007 (UTC)[reply]
The original question asked how to calculate the particle trajectory, given its starting conditions (position and momentum). That is classical mechanics, by definition. Quantum mechanics is a wholly different conceptual framework, and does not have descriptions for things like "trajectories." There is only the wave function. Given the starting conditions (i.e. initial wave-function), the end-result (resulting wave-function) can be calculated. Position and momentum are a measurement of the wave function, instead of fundamental properties (as they are in classical mechanics). Nimur22:06, 11 June 2007 (UTC)[reply]
this is not strictly true. The notion of trajectory is very much part of quantum mechanics, in the path integral formulation. There is "just the wave function", sure enough, but the wave function expresses the probabilities for certain trajectories. dab(𒁳)11:30, 12 June 2007 (UTC)[reply]
I'd recommend doing a few searches for "six easy pieces", which was a lectures series at Cal back a couple decades that is still a great place to start learning about quantum physics. -Mask?02:34, 12 June 2007 (UTC)[reply]
Looks like it, although those are more recent. I had them on cassette that had a copyright date of 1983. -Mask?11:38, 12 June 2007 (UTC)[reply]
menstrual cycle
Apparently restricting sexual intercourse to the days marked 'infertile' results in a pregnancy rate of 5% per year, for women who always have menstrual cycles between 26 and 32 days in length.
on an average 28 day cycle, what are the most infertile days of the cycle?
I'm not sure what you're referring to but the table lists the typical failure rate for the rhythm method as 25% in the first year. The easiest way to think of this is that 1/5 couples using this method will get pregnant in the first year. The article explains some issues related to the failure rate in more detail Nil Einne18:52, 11 June 2007 (UTC)[reply]
Sudies show that if one uses the Standard Days Method correctly (as that image demonstrates) there is a 4.75% pregnancy rate, however, since people who chose this method rarely do it correctly, the typical rate is 11.96%. Rockpocket21:13, 11 June 2007 (UTC)[reply]
We found a fledgling at work today; unable to fly and at severe risk of a passing cat, it was a really sad sight. But it was completely fearless - it stood in a doorway and let people walk "overhead" - which meant I could sit a few feet away and get very clear pictures. Here's five. So, are we looking at a crow, a rook, or a jackdaw (my current guess) - or something else entirely? It's the old problem of juvenile plumage, and not wanting to read too much into colouring details, that measn I can't be sure... It was certainly pretty large, about the same size as an adult blackbird, so it must have been of a fair age for a fledgling. Shimgray | talk | 21:02, 11 June 2007 (UTC)[reply]
I'd agree, it definitely looks like a jackdaw. Identifying features: it's a corvid because of the dark bulge at the upper base of the beak and the appearance of the feet; its bill is too pointed and narrow to be a crow or a rook; it has the grey (rather than black) head, breast and nape plumage of a jackdaw and it has a jackdaw's pale whitish-grey eye. QED :-) --YFB¿22:10, 11 June 2007 (UTC)[reply]
Hello. Ground wires discharge objects and carries the charge to the ground. Can this charge in the ground cause lightning? Thanks. --Mayfare22:31, 11 June 2007 (UTC)[reply]
Dont think so- though it depends on how you define ground. Is a standing tree or a building ground? Lightning can certainly jump from a tree to you, thence to (real) ground. Since the potential difference is originally created between the cloud and the earth, once the charge has passed to ground there wont be any lightning produced from the ground because the charge cannot appreciably raise the potential of the ground.
This is not to say that you are safe: currents in the ground can produce lethal potential differences in the space of one stride. I believe it is quite a common occurence for cattle to be killed this way since they have a longer wheelbase than humans. If out in lightning waether, its better to take small steps (and keep low).
It is unlikely that any household utility electric circuit can supply enough charge or current to induce lightning; numerous safety faults and circuit breakers would cut off the power before a large charge could accumulate in a small amount of time. However, charge on the ground can accumulate as part of normal atmospheric lightning. See Lightning#Types_of_lightning for a discussion of ground-to-cloud, cloud-to-ground, and other strikes. Nimur18:07, 12 June 2007 (UTC)[reply]
Ah, another one of those things where we have to be careful about what "cause" means. If your lightning rod is the highest object around, then most likely the lightning will strike (either originating from or going to) that rod instead of striking something else. So it does cause strikes in a sense, the probabilities of where lightning strikes has been changed and hopefully the distribution is more localized (I wouldn't want to be near one in a thunderstorm!). But will it cause more strikes in the vicinity, given a big enough, but not absurdly big, vicinity? (maybe mile wide?) I would guess not. Root4(one) 04:40, 13 June 2007 (UTC)[reply]
Lightning rods are not supposed to "attract" strikes, they are supposed to prevent them by dissipating charge slowly (preventing a strike at all). It is a common misconception that they are supposed to be the "designated target" for strikes. Nimur20:46, 13 June 2007 (UTC)[reply]
This is somewhat disputed, and as far as I know there's actually no reliable evidence that lightning rods of any design would significantly prevent (as opposed to safely channeling) lightning strikes. Part of the difficulty is that, due to the unpredictability of natural lightning, and the infeasibility of creating artificial lightning strikes of comparable scale and energy, conducting reliable statistical studies of the effects of lightning rods under natural conditions is quite hard. Lightning rod#Evaluations and analysis may be useful reading, although, as is common with Wikipedia articles on controversial topics, it's also incredibly tediously written. —Ilmari Karonen (talk) 04:05, 14 June 2007 (UTC)[reply]
June 12
car engine question
At speed, if I was to slam on the accelerator, the engine RPMs increases immediately but it takes several seconds of high RPM for the vehicle to finish accelerating to its new speed. My question is, what mechanical component is between the engine and the drive shaft to allow the drive shaft to actually be accelerated instead of a violent and instantaneous change to the new engine rpm, and how does it work? --frotht00:25, 12 June 2007 (UTC)[reply]
Er, that sounds like you have things the wrong way around. You either have an automatic (in which case when you slam on the revs, the RPM increases because the gearbox downshifts to a lower gear; then the engine RPM goes up dramatically because the drive shaft is rotating at more or less the same speed as before the shift, but now the engine has to run faster "to keep up with it") or your clutch is slipping really, really badly (i.e. the engine responds to the throttle by increasing RPM [although this isn't instant] and the clutch doesn't have sufficient friction to accelerate the drive shaft at the same rate) - this would be a bad thing. Since you're in the US where hardly anyone knows how to drive a proper car ;-) it's probably the former. --YFB¿00:30, 12 June 2007 (UTC)[reply]
Well, sort of, but the question would make sense if it was an automatic. If you stand on the throttle, the gearbox will almost-instantly downshift and there will then be a near-instantaneous jump in revs. The several seconds Froth mentions is the car accelerating (with the revs increasing further) after the downshift. Or, as I said, he could have the world's most knackered clutch, but I think he'd be able to smell it if one plate was taking "several seconds" to catch up with the other :-/ --YFB¿02:45, 12 June 2007 (UTC)[reply]
My point is that the speedometer is clearly not moving in parallel with the -uh- RPM-o-meter. Obviously the two won't always read the same since there are gears in between, but even with gears, if you're accelerating how can the RPMs hold steady while the speed increases? Does the clutch keep slipping until you're at the right speed? And you're right, I only know how to use an automatic transmission, I hate cars and can barely put up with automatic, but the car is defying me with this stupid question :) --frotht14:08, 12 June 2007 (UTC)[reply]
The torque converter does allow some "slip", but most of what you're seeing is explainable just by gearing. The other "slack" factor you may see is that your gauges aren't instantaneous either. Generally they shouldn't be far behind, but you never know. Friday(talk)14:53, 12 June 2007 (UTC)[reply]
To first order, you shouldn't see an acceleration without an increase in revs - if the car is driving at constant speed then the revs will be constant, then when you increase the revs the increase in the speed of the wheels is the change in rpm divided by the gear ratio (approximately - not including assorted other transmission components, overdrive, etc.). So if you keep the revs constant, the only way to increase speed is to change to a higher gear, which will inevitably involve a change in revs anyway due to the engine being unloaded while the gears shift. You'd have a better idea what was going on if you drove a manual, since you have to match the revs yourself on downshifts to make them smooth. I hate automatics. There's nothing to do with your left leg and (particularly in the States where you don't have any bends either) it's too easy to fall asleep at the wheel through boredom. Not to mention the fact that the transmission steals a significant portion of your engine power just to save you using one arm and one leg every now and again. Bleh. --YFB¿22:46, 12 June 2007 (UTC)[reply]
It promotes the production of kidney yin and prolonged use is beneficial for sexual weakness. Even though its greatest value is in its "love tonic" attributes, wild asparagus root is often used in tonics designed to overcome impotence or rigidity on the physical level.
So, If you believe your "kidney yin" is the cause of your "sexual weakness" then an asparagus root "love tonic" may be the treatment for you. However, TCM also advocates the consumption of animal testicles to boost sperm count, so you might want to try those first. Rockpocket02:04, 12 June 2007 (UTC)[reply]
First of all, you should ask your doctor this question, not a team of pseudo-anonymous volunteers. 1. That being said, the NSAIDS in a gel or liquid suspension might not work for any number of reasons. What active ingredient did you have in mind, if not aspirin? Ibuprofen? 2. I would doubt that most NSAIDs need to be metabolized to become active. In fact, most are hepatoxic. As the Non-steroidal anti-inflammatory drug article states: "Most NSAIDs are metabolised in the liver by oxidation and conjugation to inactive metabolites which are typically excreted in the urine, although some drugs are partially excreted in bile." --Rajah02:54, 12 June 2007 (UTC)[reply]
I don't understand what you said. I know this doesn't work, or else there would be products out there. I was referring to ibuprofen or aleve. Anyways, a doctor a) might not even know this b) I don't need to know c) I don't have rhinitis d) it would cost me 160$ to find out if the doctor did know. Thanks, though.
Careful...a possible, workable thing might not exist on the market solely because no company at this time finds it in its best business-interests to do so. The NSAID page teaches that the drugs are generally absorbed well via GI. Maybe the drug has poor absorption on mucosal membranes? The ibuprofen article suggests that half of the drug needs to be metabolized into a more active form. DMacks05:19, 12 June 2007 (UTC)[reply]
Don't NSAIDS have other effects on mucus membranes than just inflammation suppression? I was under the impression that the upset-stomach side effect of aspirin was due to less mucus, so maybe it would dry the sinuses too much. I think some of the reason is that steroids work pretty well in this application, and work at low enough doses that there isn't much sytemic effect.--Joel18:39, 12 June 2007 (UTC)[reply]
Insect cacoomb? cucomb? ARRRG!!
THIS WORD IS PROPELLING ME PRECARIOUSLY CLOSE TO INSANITY.
Insects can build house-like structres made from various materials; catepillars turn into butterflies inside of this structure.
The problem is spelling it.
cacoomb?
cacoombe?
cucoomb?
cucumb?
kacumb?
I do know it is NOT spelled: "coxcomb."
This word is either: A) some plant, or B) "a conceited, foolish dandy; pretentious fop."
Ahhh, that's it. Thank you kindly. As for the previous question, it's a process called verbal fronting. If the link isn't red, you can take a look. 'b' is easier to pronounce than 'n' (at least to USA Southerners); therefore most of us pronounce "cacoon" as "cacoombe." It is extremely fustrating at times (esp. when utilizing a dictionary). --67.177.170.9606:02, 12 June 2007 (UTC)[reply]
Do you really pronounce the b? How about in lamb? If in fact you mean the /n/ becomes /m/, I'm still surprised (though less so), because I'm told that in Spanish final m (e.g. in Latin words) is pronounced /n/, and I believe Spanish is not the only language with that habit. —Tamfang06:21, 12 June 2007 (UTC)[reply]
Yes, believe it or not, a majority of USA Deep Southerners pronouce lamb as "lahmmbe" (with a hard labial 'b') and cacoon as "cah-COOM-bh" (with a soft labial b). 'ń' (nat) and 'n' (skinny) are very hard sounds for us to make...haha. If I knew my IPA I would use it, but it's been a while. --67.177.170.9606:28, 12 June 2007 (UTC)[reply]
My car needed some brake repair, and the clerk writing me up looked at the tires and remarked, "Your tires are filled with nitrogen; you need to either use only nitrogen to pump them up, or have the nitrogen removed and fill them with air." What?! How can an intermediate blend of nitrogen be worse for my tires than either 4/5 (common air) or 5/5? —Tamfang06:25, 12 June 2007 (UTC)[reply]
The clerk is mistaken. Mixing compressed air in with the nitrogen will do no harm, but it will dilute somewhat the putative advantages of the nitrogen-only fill. You've either got a poorly-trained clerk, or you've got a clerk who thinks that you're gullible. ("It's not safe for you to mix that dirty, free air into your nitrogen-filled tires. Don't worry though, we'd be glad to top off your nitrogen for twenty bucks.")
Note that benefits of nitrogen for someone who drives under reasonable conditions are probably negligible: [7]. You can get the same improvement in mileage just by regularly checking that your tires are properly inflated. TenOfAllTrades(talk) 08:57, 12 June 2007 (UTC)[reply]
It's always important to maintain proper tire pressure. That preserves the handling characteristics of the car and helps prevent blowouts and other tire failures. All the nitrogen does is reduce the effect of temperature on tire pressure, and cars already have plenty of safety margins there anyway. — Lomn13:34, 12 June 2007 (UTC)[reply]
Yes, of course it's important, I just meant that with nitrogen, you might not have to check it as often to make sure the pressure is correct. I see how it could be misunderstood, though. :-) Also, everyone, remember that too low pressure means worse fuel economy, which will cost you more and, more importantly, harm the planet through more emissions. —Bromskloss14:56, 12 June 2007 (UTC)[reply]
lens
if lens is halh covered ,what happens to image
Even if you cover up one part of the lens, there are other paths for the light to reach the image.
Ah, good question. I think the answer is that the image will get darker, not partially obscured. As you can see in the illustration here, the light emanating from an object can hit any part of the lens and end up on the correct spot on the image anyway. Therfore, if you cover one part of the lens, you will block some of the light, but are still lightrays from the object slipping through elsewhere. That said, some parts will probably be darker than others because a larger part of the lightrays from an object hit the part of the lens that is closest to the object and also because what I said is only true (I think) if you approximate the lens to lie in a single plane (not having anyt thickness). —Bromskloss07:59, 12 June 2007 (UTC)[reply]
(ec) Mostly, not a lot happens except that the image is only half as bright, or more technically, has only half the irradiance. Think about what happens when you half close your eyes. However, there can also be changes in the quality and sharpness of the image, depending on the lens or lens system, due to the suppression or enhancement of aberrations. Also, if the original image is somewhat out of focus, the image with the lens half covered may appear to be sharper, because of the effective reduction in f-number. But usually, you will still see all of the image. The ray diagrams under lens (or helpfully supplied here) may help to explain this. --Prophys08:07, 12 June 2007 (UTC)[reply]
On second thoughts, half-closing your eyes is not a good example, because in fact your field of view does become more restricted when you do that. This is an example of vignetting, which happens when you reduce the area of the lens with a screen or aperture that is not close to the lens, but some distance from it. Then you get partial dimming or even cutting off of the edges of the image. If the aperture is right next to the lens, (technically, at one of its principal planes), then the area of the image is not affected by the area of the aperture. As the aperture is moved further away from the lens, the effect on the area of the image becomes more severe. If the aperture is in the plane of the image, then the area of the image is obviously the same as the area of the aperture. --Prophys12:51, 12 June 2007 (UTC)[reply]
If the covering is some distance in front of the lens, there may be darkening of half of the image more than the other half. For this to work as expected, and cause overall darkening, I would expect it would have to be immediately in front of or behind the lens. To be sure that the only effect is overall darkening of the image, the ideal place for the covering to be is between the elements of the lens, at the nodal point, where the diaphragm, iris, or aperture is in a camera. Waterhouse stops were provided with early cameras. They were metal strips with different size holes in them which could be inserted in the lens. The goal of "stopping down" the lens is not so much to reduce the light going through the lens (the slow film of that era needed lots of light to make a good negative]] , but to restrict the path of the light to the center of the lens, where aberrations were least, and to improve the depth of field. One reason human vision is better in bright light is thet the iris of the human eye similarly "stops down" to keep the light path to the sharper central portion of the visual pathway. Edison13:12, 12 June 2007 (UTC)[reply]
Temperature
If today's temperature is Zero degrees centigrade (0°C), the experts predict that it will be twice as cold tomorrow, how cold will it be in degrees centigrade?41.222.12.9111:38, 12 June 2007 (UTC)[reply]
that question is impossible to answer outside of context. Scientifically, there is no such thing as 'cold', just the absence of heat. You can take away or add heat to a substance, you can't add 'cold' outside of finding a way to remove the heat. -Mask?11:48, 12 June 2007 (UTC)[reply]
This question could be tackled if you adopt a "relative" stance. Relative to yesterday, when the temperature was (say) 5°C, the temperature has dropped by 5 degrees. So, if tomorrow is going to be "twice as cold", you could argue tomorrow's temperature will be -5 or -10 depending on how you define "twice". So... what was the temperature yesterday? Incidentally, if the problem is supposed to be about difficulties of multiplying by zero (which it isn't currently... it's about lack of information) you can always avoid the issue by working in Fahrenheit or Kelvin or whatever other scale you fancy (take a look here). --Dweller12:06, 12 June 2007 (UTC)[reply]
This sounds kind of like a homework question. If you assume twice as cold is the same as half the temperature, 0°C = 273.15K / 2 = 136.575°K - 273.15°K = -136.575°C. See Kelvin as noted above for more info.--GTPoompt(talk)12:13, 12 June 2007 (UTC)[reply]
The "experts" don't predict that it will be "twice as cold" tomorrow. They predict a specific temperature range; it's some wooly-headed reporter or other commentator who comes up with a claim like "twice as cold", which, as we've seen here, is fairly meaningless. (Me, I'd imagine that "twice as cold" means that (comfortable temperature - tomorrow's temperature) = 2 × (comfortable temperature - today's temperature), but we still get to argue over what "comfortable temperature" is.) —Steve Summit (talk) 13:01, 12 June 2007 (UTC)[reply]
Since dissolved salt in water doesn't stay salt, but splits up into the ions (Na+, Cl-), how does gargling with saltwater (which doesn't contain salt) actually kill bacteria in the throat? The common explanation is that salt causes the bacteria to barf up all their water, but that doesn't make sense if there's no salt in saltwater. — BRIAN0918 • 2007-06-12 12:01Z
Claiming that "salt water doesn't contain salt" is a typical act of pedantry. For all intents and purposes, salt water does contain salt, as (a) its name, (b) its taste, (c) the residue left after evaporation, and most importantly here (d) its effect across osmotic membranes and salinity gradients all attest. —Steve Summit (talk) 12:39, 12 June 2007 (UTC)[reply]
You haven't really given an answer. Is it that you have to add more salt than can be dissolved in the water? — BRIAN0918 • 2007-06-12 12:44Z
He was stating that your assumption that salt crystals are required to kill bacteria is a false one. A salt crystal is a stable molecule. It won't do anything. When dissolved (turned into active floating ions), the salt will do its job. --Kainaw(talk)12:52, 12 June 2007 (UTC)[reply]
(ec) I'm not sure why gargling with salt water works, either (though I have experienced that it does). But your explanation that it "causes the bacteria to barf up all their water" sounds perfectly plausible to me.
If you add more salt than can be dissolved in the water, the undissolved salt sits at the bottom as granules, and I wouldn't say that the water "contains" it. It's the dissolved salt, of course, that gives salt water its properties (bactericidal and otherwise). —Steve Summit (talk) 12:53, 12 June 2007 (UTC)[reply]
I'm getting the feeling you didn't really know the answer and are just restating other people's answers or using circular reasoning (as in your original post). That's fine, I can wait for someone who actually knows. — BRIAN0918 • 2007-06-12 13:11Z
I'm sorry, when you said "The common explanation is that salt causes the bacteria to barf up all their water, but that doesn't make sense if there's no salt in saltwater", I though you meant, "I can understand that salt would make the bacteria barf up all their water, but that doesn't make sense because there's no salt in saltwater." —Steve Summit (talk) 13:21, 12 June 2007 (UTC)[reply]
The trick is osmosis, which I think is what Ummit was trying to get at there, somewhere. The cell wall of a bacterium is a semi-permeable membrane, meaning it lets some things (like water) through and others (like sodium and chloride ions) out. When you gargle salt water, water rushes through the membrane in an attempt to equalise the salt concentrations - but, since the salt water contains a lot of salt, and the bacteria contain just a little water, what happens is that, in a sense, the bacteria "barf up all their water". Confusing Manifestation13:02, 12 June 2007 (UTC)[reply]
I'm confused. Why does the water rush out of the bacteria if the water inside the bacteria has less salt. I guess the confusion is what you mean by "equalize the salt concentrations". — BRIAN0918 • 2007-06-12 13:10Z
It's a fundamental principle (which I can't give an explanation for) that concentrations of dissolved substances want to equalize. If you have a higher concentration of solute in region A than in region B, you can equalize them either by adding solvent to region A (perhaps by moving it from region B), or by adding solute (e.g. salt) to region B (perhaps by moving it from region A). But if the regions are separated by a semipermeable membrane, that can pass solvent but not solute, then only the first option is available. —Steve Summit (talk) 13:21, 12 June 2007 (UTC)[reply]
Yeah, I just figured that out myself. I'm sure I learned it in one of my chem courses, but I obviously didn't retain that knowledge. I did, however, retain the loans. — BRIAN0918 • 2007-06-12 13:23Z
There is no evidence that gargling with salt water kills bacteria. Period. This is folk medicine (I was taught to do it by my mother also). From the standpoint of scientific medical practice it is a harmless "comfort measure", but do not imagine that it is accelerating your recovery from a bacterial infection-- most sore throats are viral. alteripse13:27, 12 June 2007 (UTC)[reply]
So where does the comfort come from. It does make you feel better temporarily. Why? Tufts says that it actually "washes away the layer of mucus on the throat containing bacteria". Why salt-water specifically? Would sugar water also have the same "washing away" effect? — BRIAN0918 • 2007-06-12 13:29Z
However, in answer to the "how does it soothe" question, I don't know. Some of the possible variables: (1) whether you have been told it is effective or ineffective, (2) warm, neutral or cold temp, (3) tonicity of the the salt (hypo-, hyper-, or normal), (4) solute in the water vs plain water, (5) salt, or sugar, or other solute, (6) how much trouble you invest in the preparation. PS: I do not scorn the therapeutic value of Mr Placebo! alteripse13:49, 12 June 2007 (UTC)[reply]
Gargling with salt water might loosen the mucus in the throat, helping your body cough up or swallow irritating mucus build-up. -- JSBillings14:32, 12 June 2007 (UTC)[reply]
Gas cylinders
I have used gas cylinders for years in my work and I have never before noticed the regulator getting particularly cold. Recently I have been using CO2 (which I don't normally use) and letting it run at a rate that is quick relative to what I usually do; in this case the regulator gets very cold and sometimes ices up to the point of not working correctly.
So my question is... which is the difference that's causing this 1) the CO2 or 2) the relatively fast rate? The CO2 in a compressed gas cylinder isn't liquid is it? ike989813:20, 12 June 2007 (UTC)[reply]
The answer is mostly the rate of release. Any time When you release a pressurized gas, it often gets cold. This can be thought of as a manifestation of conservation of energy at work -- when you compressed that gas, it got hot. (That's why compressors often have big cooling fins on them.)
Some refrigerated trucks are cooled not by mechanical refrigerators, but by the gradual release of pressurized nitrogen carried in a tank underneath. —Steve Summit (talk) 13:25, 12 June 2007 (UTC)[reply]
Both 1 and 2. CO2 comes out of the cylinder particularly cold because it is liquified rather than simply compressed, so you have to supply the enthalpy of vaporization to get it into the gas phase. The fast rate will cool it even further, due to the Joule-Thomson effect (which is what Steve Summit is referring to above). When you use a CO2 fire-extinguisher, which is simply a CO2 cylinder adapted for simple and rapid release of the gas, you often get the CO2 coming out as a "snow" of dry ice: not a problem, as the dry ice quickly evaporates to give the gaseous CO2 needed to extinguish the fire, but spectacular none the less! Physchim62(talk)13:29, 12 June 2007 (UTC)[reply]
The only correct solution to the problem is to change the regulator: with a wider opening between the piston and its seat, you will reduce the Joule-Thomson effect. Your gas supplier should be able to give you advice on this one, although you might wish to talk to their competitors as well, as prices can vary considerably. The minimum information required is
the desired flow rate of CO2
the length of time the gas will be flowing for; you can tolorate a greater cooling for an intermittant flow than for a continous flow
the minimum ambient temperature of the installation
With the first two factors (and a few other parameters which you gas supplier will know), you can estimate the cooling power of the depressurization: with the second two, you can estimate the warming power of the surroundings. You must keep the outlet temperature within the operating range of the regulator, and ideally you should try to keep the outlet temperature below the dew point of the surrounding air (to avoid condensation on the regulator). There are other possible fixes, but nothing which I would really like to recommend on a public forum! Physchim62(talk)16:19, 12 June 2007 (UTC)[reply]
Thanks for the help, guys. One last point I'm not 100% clear on: In cylinders of many compressed gasses (N2, O2, He2) the gas is NOT liquified, correct? ike989817:55, 12 June 2007 (UTC)[reply]
Correct. Carbon dioxide is stored liquified, some short-chain hydrocarbons (propane, for example) are stored liquified, but almost everything else won't liquify at reasonable temperatures no matter how much you compress it. --Carnildo00:17, 13 June 2007 (UTC)[reply]
By the way, this problem can happen in scuba diving regulators as well when the ambient water temperature is low. That article mentions adiabatic expansion as the cause. Divers crazy enough to dive in cold environments will usually choose environmentally sealed regulators or other equipment specially designed for cold temperatures. (By the way, I'm in the "crazy enough" category, since I live in Minnesota.) --Elkman(Elkspeak)20:37, 12 June 2007 (UTC)[reply]
You might want to try putting heater tape on the regulator. To visualize, when the gas is compressed the collision rate between molecules increases. Energy is lost in the form of heat until the gases slow down and the collision rate is essentially the same as pre-compression. When you let the gas out, the molecules still have the same velocity and they collide with the warm regulator and take energy from it. This speeds up/heats up the gas molecules and cools the regulator. Increasing the surface area/diameter of the regulator pipe will alleviate ice build up as will heating the regulator. --Tbeatty22:11, 12 June 2007 (UTC)[reply]
after watching 24 yesterday again, these questions came up again:
1) Do people really instantly go unconscious when hit over the head or neck (i.e. pistol-whipped)? In movies it seems like there is a 100% chance when you hit somebody on the neck that he will go unconscious.
2) There is always some kind of stick with I presume gas in it, which people break into two and then hold under the nose of an unconscious person and he instantle regains consciousness. What kind of stuff is in that breakable bar?
It is very rare for someone to lose consciousness when hit. It is merely a very bad writer's tool for getting people out of a scene quickly. As for the "stick", see smelling salts. --Kainaw(talk)13:37, 12 June 2007 (UTC)[reply]
Well, hitting hard enough would do the trick, don't you think? The problem, as I see it, is hitting hard enough and still not so hard that you kill the victim or inflict more severe damage. Anyway, in Tintin (which I otherwise like very much), they seem to use that perfect amount of force all the time. —Bromskloss13:58, 12 June 2007 (UTC)[reply]
It's more complicated than that, of course. If it's a bad guy, a single hit (of almost any degree) will induce unconsciousness. The good guy, on the other hand, can withstand innumerable blows, with the exception of the one per episode which is necessary to effect a capture so that he can (a) learn the last stages of the master plan from the evil overlord during a "last" interview while terminally imprisoned in his inner sanctum, and then (b) spectacularly escape. --Steve Summit (talk) 15:43, 12 June 2007 (UTC)[reply]
I'd think that you'd be more likely to have someone screaming and holding the back of their head, or lying on the floor drowning in a pool of their own blood than to knock them out clean. In any case their hair will at least be matted and bloody after, which seems to rarely happen in movies/tv --frotht14:13, 12 June 2007 (UTC)[reply]
The effect is based on the idea that you can hit a major artery, cause a sudden increase in blood pressure, and then have the body quickly stop blood flow to reduce blood pressure. Then, the person passes out. That rarely happens. It takes a very exact hit and the hope that the person's body will response accordingly. It takes a hell of a lot of luck to knock someone out with a concussion, which is what the movies tend to make it look like. People get out of car accidents and walk away all the time. --Kainaw(talk)14:26, 12 June 2007 (UTC)[reply]
The 1728 Cyclopaedia would be a good source for this info (volumes: 1, 2). I couldn't find anything in their entry for Pharynx or Sinus, however, and there is of course no article titled "strep", nor one for "yeast". The hard part is figuring out what these illnesses were called back then. Maybe a medical history book would work better. You may also look at the folk treatments that are still used today for these illnesses as many of them may be much older traditions. — BRIAN0918 • 2007-06-12 15:03Z
I was just about to post the same thing. The only thing they really prescribe is for severe cases ("severe" by today's standards?), and that is just to slice and dice your way back to healthiness. — BRIAN0918 • 2007-06-12 15:19Z
"they seemed to have conflated what we see as distinct illnesses into groups" - I think you'll find the truth is the exact reverse of that. We've separated out distinct illnesses from what were once thought of single conditions. -- JackofOz23:58, 12 June 2007 (UTC)[reply]
Psychoactivity of Coleus?
I recently stumbled upon a section on erowid.org that has numerous reports of people who feel psychoactive effects after smoking or chewing coleus. So I ask: is the coleus plant psychoactive? What chemicals in coleus are psychoactive? How would coleus be classified and what neurotransmitter systems are effected? Are there any health risks or any potential for abuse? Jolb16:24, 12 June 2007 (UTC)[reply]
As I see nothing about it in the article, I'm guessing this is not well understood. As always, we cannot dispense medical advice, but prudence would suggest being cautious in ingesting unknown substances. Plenty of plant alkaloids have psychoactive effects, for what it's worth. Friday(talk)16:58, 12 June 2007 (UTC)[reply]
Is this plant related to khat? Khat, another African plant leaf that is chewed, is a stimulant with some other reported psychoactive effects. The taxoboxes say they are both in the same class (biology), Magnoliopsida; how "related" is this? (My guess is "not closely.") Nimur18:12, 12 June 2007 (UTC)[reply]
Coleus is related to salvia, basil, and mint. Coleus and khat are not related: class Magnoliopsida encompasses a majority of known flowering plants. Cheers, Dr_Dima.
Criteria for Sluggish cognitive tempo
In the Wikipedia article it says: "Sluggish cognitive tempo (SCT) is a descriptive term which is used to better identify what appears to be a homogeneous group within the Predominantly Inattentive Type (ADHD/PI) DSM-IV classification." Yet in one of the referenced articles,[1] it says: "Many ADD children, although not all, appear sluggish, drowsy, spacey, lethargic, and markedly hypoactive. They fit the criteria for having a sluggish cognitive tempo (SCT)." In this article, the term ADD is used for "the truly inattentive type of ADHD (not simply the subthreshold combined type)".
So, apparently, some ADD children do not fit the SCT criteria. Does anybody know what are the criteria for SCT? Or, if there is no consensus about them yet (because SCT is not part of the DSM-IV), does anybody have a list of criteria for SCT that is in use? Lova Falk18:19, 12 June 2007 (UTC)[reply]
I hope my answer is relevant to you. I googled SCt criteria and looked at some studies and one of the studies that popped up (the link below) seemed to pull their diagnostic criteria from Child Behavior Checklist (CBCL) by Thomas M. Achenbach. I haven't found the actual criteria yet. I also found this paragraph in the same paper which may explain why some ADD individuals o not fit SCT criteria. http://findarticles.com/p/articles/mi_m0902/is_5_32/ai_n6234463
Studies of ADHD subtypes as defined in the third edition of the DSM (DSM-III; American Psychiatric Association, 1980) revealed some differences in the specific attentional dysfunction exhibited by each of the groups. Specifically, children with DSM-III attention deficit disorder with hyperactivity exhibited inattention symptoms characterized by sloppy work and distractibility, whereas children with DSM-III attention deficit disorder without hyperactivity were rated higher on inattention items measuring daydreaming, tendency to become confused, lack of mental alertness, and physical hypoactivity (e.g., Barkley et al., 1990; Hynd et al., 1989; Lahey & Carlson, 1991; Stanford & Hynd, 1994), a cluster of symptoms that has subsequently been labeled sluggish cognitive tempo (SCT). On the basis of these findings, the DSM-IV field trials (Lahey et al., 1994) tested the utility of SCT symptoms for the diagnosis of the inattentive type. Consistent with studies of DSM-III ADD, the field trials found that SCT symptoms were associated most strongly with the DSM-IV predominantly inattentive type (Frick et al., 1994). However, further analyses indicated that the majority of individuals with the DSM-IV inattentive type did not exhibit SCT symptoms, so these symptoms were not included in the diagnostic criteria for DSM-IV ADHD. Sifakatalk22:20, 12 June 2007 (UTC)[reply]
I need to have a lab-sheet for a plant-related experiment (hypothesis, test conditions, results). Failing that, I would greatly appreciate a simple graph of some plant experiment, preferably with context provided.
I need this information badly for a course. If I have ever needed information from Wikipedia, I need it here and now.
Er, that would I believe be covered by the notice at the top of this page reading "do your own homework". --YFB¿23:51, 12 June 2007 (UTC)[reply]
I'm not asking you to do my homework, I just need a link to an experiment page, a PDF, something... you are human as well... ~ Flameviper00:03, 13 June 2007 (UTC)[reply]
Finding scientific papers related to plants is easy if you know where to look. Try [scholar] and pick some topics that you think would be interesting to you. Read the abstracts of the articles that appear and decide if it is relevant. Scientific names of plants will help you more than common ones. Wikipedia is excellent for figuring out the scientific name of a common plant.
If what you are looking for is an experiment you can do yourself, here are two suggestions on two simple experiments to generate the things you are looking for.
Here is a classic plant experiment that usually produces clear results that you might attempt if you are looking for an experiment to do with minimal prep equipment. Set up an experiment that will test whether a plant will transpire more in windy conditions or in still air conditions.
consider how the area of the plant surface might affect the results
Think about the design the setup
You can use a clipping of a plant rather than a whole plant with roots (at least several leaves and a stem for best results)
If time is of the issue more than clarity of results and you have access relatively common lab equipment, you may want to try comparing the percent moisture content of leaves between species, different plants... You will have to figure out a way to remove most of the water from the leaves and figure out how much was lost. Sifakatalk00:15, 13 June 2007 (UTC)[reply]
...The water loss per square centimeter of each leaf in one hour (t/c2) will be the standard for the measurement. The transpiration rate for both leaves (pineapple and oak) will be taken from a one-centimeter-wide square cut from each leaf...
I don't have the time, resources, or inclination to find this out myself. Does anybody have a clue as to the quantitative value of the water loss per square centimeter for oak and pineapple? If you don't have it for oak and pineapple, I just want a temperate/polar plant and a tropical/humid-area plant. The one who answers my query will receive something nice in return.~ Flameviper00:39, 13 June 2007 (UTC)[reply]
