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If chromosomal duplication happens twice before tetrad formation in spermatogenesis, while the other steps proceed normally, would the resulting 4 sperm cells be considered diploid because they each have 2 copies of a gene or haploid because the 2 copies are of the same homologue? In other words, does the term "diploid" in humans refer only to the total number of chromosomes (twice the number of the haploid state) or the state of having a pair of homologous chromosomes each with differing alleles for the same genes? thanks, N.S.
I'd like to make my own version of this graph. Where can I get a raw set of values for it? I tried googling a bit but all I found were fairly tedious formulae for computing the average binding energy per nucleon and all of that -- surely it is available somewhere more easily? I'm no physicist and would prefer not to have to try and fumble through the calcuations. Anybody have them at hand (or willing to do the calculations for me?)? I'll donate an SVG version of the resulting graph to Wikipedia if that's worth anything to you. -- 24.147.86.187 04:24, 7 January 2007 (UTC)
My dad said that Waterpik waterjets (used instead of flossing) are actually dangerous, because the force of the water pushes bateria and such deeper into the gums and even the bloodstream. Is this true, or even possible if used properly? -- RockMaster 05:33, 7 January 2007 (UTC)
Well, thank you all for your help; I think I've got just about everything I need. This should be enough to convince him. A good night to all, and to al a good night. -- RockMaster 00:38, 9 January 2007 (UTC)
So I've been wondering this since every time I've seen a photo taken with tilt-shift lenses, but I haven't ever found an explanation. What exactly makes a photo taken with a tilt-shift lens look like it was taken in miniature? What is responsible for the "miniaturization?" Maybe another way of putting it is what is the visual difference between a normal scene and a miniature version of that scene?
I think any discussion would be a great way to expand the stub on tilt-shift photography. For an example picture, see this picture. - Michael 05:42, 7 January 2007 (UTC)
Here is my space, You can see the picture I took http://lionongshop.spaces.live.com —Preceding unsigned comment added by 211.30.34.134 ( talk • contribs) 10:03 7 January 2007
'All that may come to my knowledge in the exercise of my profession or in daily commerce with men, which ought not to be spread abroad, I will keep secret and will never reveal.' This is a part of the Hippocratic oath, but can I still trust a doctor not to tell anyone anything, since apparently the hippocratic oath isn't used much any more? Hidden secret 7 11:56, 7 January 2007 (UTC)
I have been re-reading The End of Time by Julian Barbour. As far as I understand it, his thesis in summary is:
Have I correctly understood Barbour's position ? Is it a respectable (although possibly minority) position in mainstream physics, or is it closer to pseudoscience ? Have any other physicists written about similar ideas in accessible publications ? Gandalf61 11:57, 7 January 2007 (UTC)
Hi i recently did a biological experiment investigation, involving different respiratory substrates for yeast cells Saccharomyces cerevisiae. I found that lactose hardly respired at all. Why would this be? I thought it could be due to the disaccharide formation of lactose, with galactose, having a sterio isomer which is not fermentable by yeast, but then surely i should get at least some respiration. Or perhaps another angle would be the fact thatthe yeast did not have the appropritate enzyme to break the bond between the saccharides? Any comments or opinions on this matter would be greatley appreciated. — Preceding unsigned comment added by 81.156.37.191 ( talk) 08:47, January 7, 2007 (UTC)
Can Saccharomyces cerevisiae break down lactose? or does it not have the enzyme lactase?thanks — Preceding unsigned comment added by 81.156.37.191 ( talk) 09:03, January 7, 2007 (UTC)
The tube deep lines have a problem with overheating. If they converted an old carriage to become a big tank of liquid nitrogen that went round squirting liquid nitrogen everywhere would it have any effect? Typo squotter 16:16, 7 January 2007 (UTC)
Okay, first let me explain the question. This person is talking about the London Underground (familiarly "the Tube") and specifically its deep-level tube lines (the only ones that are "tube lines" in strict usage). London Underground trains are not air-conditioned, and one reason often cited for this is that the deep tube tunnels are so small that there is no room to add air conditioners to the trains. (The fact that the subsurface lines are also not air-conditioned strongly suggests that this is not the only reason, but we're getting outside of science matters if we discuss that.) So this person is proposing a scheme to cool the tunnels instead.
My response to "would it have any effect" is: Yes, it would create a risk of suffocating the passengers by displacing too much air from the tunnels. This might prevent them from complaining about the heat, but is probably not the most desirable way to do so. :–) (Even if the amounts were properly controlled to avoid this, what if the tank developed a leak?) Using liquid air instead of nitrogen would avoid the suffocation hazard, but I believe it would substitute a fire hazard. In addition, squirting cryogenic liquid about the system could be damaging to any equipment (track, signals, wiring, etc.) that it landed on, due to thermal stress.
It's an interesting idea, though. It might be interesting to try to calculate the cooling available that way, ignoring the safety issues, but I'm not prepared to do it now. I do note that cooling the tunnels rather than the trains would only be helpful on the part of the journey when the trains actually are in tunnel; 5 of the 7 deep-level tube lines have long stretches of surface track as well, where the trains will heat up on a hot day.
You may be interested to know that the Channel Tunnel has a pipe carrying cold water through each tunnel, just for cooling. If a decision was made to cool the tunnels, this would probably be a safer approach, although there might not be enough cooling capacity in view of the fact that so much more of the cross-sectional area of the Tube tunnels is filled by the trains than is the case in the Channel Tunnel.
--Anonymous, January 07, '07, 20:52 (UTC).
Hi,
Does anyone know whether copper is more expensive than brass (because it's purer?) There's nothing about it on any of the wikipedia articles on either copper or brass or their talk pages. I couldn't find anything about it on the web.
Thanks, Bioarchie1234 17:40, 7 January 2007 (UTC)
What are some good techniques for sculpting and measuring a smooth sphere? I'm pretty sure there must be an ingenious way to do it, I just can't think of anything that won't be eye-measured and prone to distortions.
The case in question is that I have a round shape already, and I want to use sandpaper to finish the sphere (by hand, unfortunately that's all I have). I need it as close to a sphere as possible. — Kieff 17:58, 7 January 2007 (UTC)
Get two rectangular pieces of wood that are the same thickness as each other. Clamp them together to make a square(ish) shape. Make sure the sides are longer than the diameter of your sphere. Mark the centre of this square with a pencil, then, with pair of compasses, draw a circle the size of your sphere round this point. Take the two pieces of wood apart and cut out all the wood inside the circle, then file it or use sandpaper on it to get it perfectly circular. Glue the two pieces together and put your sphere in the circular hole. If you hold the square so it is parallel to a flat surface like a table, and so it passes through the diameter of the sphere, and then roll it around the table, you should be able to tell where it is bumpy because it will get slightly stuck. This might only work in principle, but it might work in practice too. I know you were looking for a more scientific method, but this is the best I could do! Hope it helps, if not, leave another message here or on my talk page. Bioarchie1234 19:04, 7 January 2007 (UTC)
[1] is the ball race method
Sorry if this doesn't come under science but I think it does. Anyway: Channel form efficiency and Hydraulic Radius, are they the same thing? I'm pretty sure they are but just need to double check. Thanks. 62.136.81.50 20:49, 7 January 2007 (UTC)
How do I measure how light pollution relates to the population of a certain area? And I'm doing this for a science project (hopefully you haven't seen me on another RD yet). —The preceding unsigned comment was added by Member ( talk • contribs) 21:46, 7 January 2007 (UTC).
Do animals with very good night vision detect colors in "more" brightness? From searching around, what I understand is that animals like owls have more sensitive rods that allow them to see more colors in the dark. But what does that really mean? Do owls see more colors but that the colors are still in low brightness/intensity, or do they somehow see the colors in more brightness (thus they can sense better contrast, etc.)? Thanks in advance 128.163.241.210 21:49, 7 January 2007 (UTC)
I have searched etc, and to no avail. I have to do a pie chart with % regarding the gas and water components in inspired air, and then in expired air. Do you have any ideas as to the answer, or where I could source it?
Munchkin MunchkinNZ 22:13, 7 January 2007 (UTC)
Doing some work with the VSEPR theory which is really not my field. Under VSEPR, what's the shape and bond angle of SCl2, and is it polar? I imagine that's a terribly simple question to you chemists out there, but I'd like to know. Thanks. Cool3 22:20, 7 January 2007 (UTC)
I tried looking it up, but I couldn't understand it. Especially, I can't understand how aldehyde: R-CHO is derived from the oxidation of a primary alcohol. In that context, what does oxidation mean? Thank. —The preceding unsigned comment was added by Legolas52 ( talk • contribs) 00:44, 8 January 2007 (UTC).
Oxidation is the loss of electrons. I'm not an organic chemist, but I would say that the primary alcohol loses electrons, thereby allowing it to bind to the R-group. BenC7 11:06, 8 January 2007 (UTC)
On Wikipedia's "Polystyrene" article, I noticed that it mentions that there are U.S. regulations prohibiting the use of solvents on styrofoam because it "de-foams" it. What is doesn't mention is what specific kinds of non-aqueas solvents de-foam styrofoam and why. Can anyone tell me (very specifically) why solvents have such an effect on polystyrene? EDIT: Sorry, I found it.—The preceding unsigned comment was added by 68.190.7.99 ( talk) 23:29, 7 January 2007 (UTC).
...why does Acetone dissolve it?
I once lived in San Francisco's Tenderloin in a 1920s Edwardian apartment building. Looking down on it from above, it was shaped like a capital I (although on preview I see that the font here is giving me a straight, stick-shaped I, as opposed to one with a discernable top and bottom). Two store-fronts and a basement constitued the ground floor. Facing the building from the street, on the left there was a maintenance door. If you went through it, you first went through a short passageway before emerging into an open area (by open I mean exposed to the sky). All the buildings' windows that looked down onto this middle area saw an entrance into the basement, access to the boiler, and the tail end of the trash chute, among other things. I've been to the City's official home page, I've gone through the Architectural glossary and more here on Wikipedia, poured over myriad other sites, and I can not, to save my life, put a construction, building, or architectural term to this open area. Mere curiosity isn't fueling my interest; rather, it's work-related. I realize my description is poor, but I hope it will be enough. Guesses, suggestions, site referrals and more - all welcome. Thanks. Wolfgangus 00:02, 8 January 2007 (UTC)
Coming from a position of total ignorance, and in light of your efforts, I'm uncomfortable saying this, but according to what I'm reading as definitions for a "well", it doesn't seem to qualify. Service well actually has an attractive ring to me, but in usage it may prove misleading. A while back I'd consulted a construction-management friend who suggested the term draftway but this didn't fit either.
Of course, it's entirely possible that it has no name at all, it's just a structural feature, incidental or otherwise ... but even something so insignificant as a nook is honored with a title, and the space I'm trying to name was probably 10 x 30 ft.
Perhaps I can convince someone in the City offices to glance at the blueprints. Surely they're on file and in some fashion a matter of public record. At any rate, thank you so much for your efforts; I'm grateful. Wolfgangus 19:25, 8 January 2007 (UTC)
Holy s**t. That's it. That's it! The diagram of the two tenements shows the general capital I shape, the opening, everything. Thank you so much; I can not adequately express my gratitude, but if I could, I could not possibly overstate it. Wolfgangus 03:39, 9 January 2007 (UTC)
Science desk | ||
---|---|---|
< January 6 | << Dec | January | Feb >> | January 8 > |
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. |
If chromosomal duplication happens twice before tetrad formation in spermatogenesis, while the other steps proceed normally, would the resulting 4 sperm cells be considered diploid because they each have 2 copies of a gene or haploid because the 2 copies are of the same homologue? In other words, does the term "diploid" in humans refer only to the total number of chromosomes (twice the number of the haploid state) or the state of having a pair of homologous chromosomes each with differing alleles for the same genes? thanks, N.S.
I'd like to make my own version of this graph. Where can I get a raw set of values for it? I tried googling a bit but all I found were fairly tedious formulae for computing the average binding energy per nucleon and all of that -- surely it is available somewhere more easily? I'm no physicist and would prefer not to have to try and fumble through the calcuations. Anybody have them at hand (or willing to do the calculations for me?)? I'll donate an SVG version of the resulting graph to Wikipedia if that's worth anything to you. -- 24.147.86.187 04:24, 7 January 2007 (UTC)
My dad said that Waterpik waterjets (used instead of flossing) are actually dangerous, because the force of the water pushes bateria and such deeper into the gums and even the bloodstream. Is this true, or even possible if used properly? -- RockMaster 05:33, 7 January 2007 (UTC)
Well, thank you all for your help; I think I've got just about everything I need. This should be enough to convince him. A good night to all, and to al a good night. -- RockMaster 00:38, 9 January 2007 (UTC)
So I've been wondering this since every time I've seen a photo taken with tilt-shift lenses, but I haven't ever found an explanation. What exactly makes a photo taken with a tilt-shift lens look like it was taken in miniature? What is responsible for the "miniaturization?" Maybe another way of putting it is what is the visual difference between a normal scene and a miniature version of that scene?
I think any discussion would be a great way to expand the stub on tilt-shift photography. For an example picture, see this picture. - Michael 05:42, 7 January 2007 (UTC)
Here is my space, You can see the picture I took http://lionongshop.spaces.live.com —Preceding unsigned comment added by 211.30.34.134 ( talk • contribs) 10:03 7 January 2007
'All that may come to my knowledge in the exercise of my profession or in daily commerce with men, which ought not to be spread abroad, I will keep secret and will never reveal.' This is a part of the Hippocratic oath, but can I still trust a doctor not to tell anyone anything, since apparently the hippocratic oath isn't used much any more? Hidden secret 7 11:56, 7 January 2007 (UTC)
I have been re-reading The End of Time by Julian Barbour. As far as I understand it, his thesis in summary is:
Have I correctly understood Barbour's position ? Is it a respectable (although possibly minority) position in mainstream physics, or is it closer to pseudoscience ? Have any other physicists written about similar ideas in accessible publications ? Gandalf61 11:57, 7 January 2007 (UTC)
Hi i recently did a biological experiment investigation, involving different respiratory substrates for yeast cells Saccharomyces cerevisiae. I found that lactose hardly respired at all. Why would this be? I thought it could be due to the disaccharide formation of lactose, with galactose, having a sterio isomer which is not fermentable by yeast, but then surely i should get at least some respiration. Or perhaps another angle would be the fact thatthe yeast did not have the appropritate enzyme to break the bond between the saccharides? Any comments or opinions on this matter would be greatley appreciated. — Preceding unsigned comment added by 81.156.37.191 ( talk) 08:47, January 7, 2007 (UTC)
Can Saccharomyces cerevisiae break down lactose? or does it not have the enzyme lactase?thanks — Preceding unsigned comment added by 81.156.37.191 ( talk) 09:03, January 7, 2007 (UTC)
The tube deep lines have a problem with overheating. If they converted an old carriage to become a big tank of liquid nitrogen that went round squirting liquid nitrogen everywhere would it have any effect? Typo squotter 16:16, 7 January 2007 (UTC)
Okay, first let me explain the question. This person is talking about the London Underground (familiarly "the Tube") and specifically its deep-level tube lines (the only ones that are "tube lines" in strict usage). London Underground trains are not air-conditioned, and one reason often cited for this is that the deep tube tunnels are so small that there is no room to add air conditioners to the trains. (The fact that the subsurface lines are also not air-conditioned strongly suggests that this is not the only reason, but we're getting outside of science matters if we discuss that.) So this person is proposing a scheme to cool the tunnels instead.
My response to "would it have any effect" is: Yes, it would create a risk of suffocating the passengers by displacing too much air from the tunnels. This might prevent them from complaining about the heat, but is probably not the most desirable way to do so. :–) (Even if the amounts were properly controlled to avoid this, what if the tank developed a leak?) Using liquid air instead of nitrogen would avoid the suffocation hazard, but I believe it would substitute a fire hazard. In addition, squirting cryogenic liquid about the system could be damaging to any equipment (track, signals, wiring, etc.) that it landed on, due to thermal stress.
It's an interesting idea, though. It might be interesting to try to calculate the cooling available that way, ignoring the safety issues, but I'm not prepared to do it now. I do note that cooling the tunnels rather than the trains would only be helpful on the part of the journey when the trains actually are in tunnel; 5 of the 7 deep-level tube lines have long stretches of surface track as well, where the trains will heat up on a hot day.
You may be interested to know that the Channel Tunnel has a pipe carrying cold water through each tunnel, just for cooling. If a decision was made to cool the tunnels, this would probably be a safer approach, although there might not be enough cooling capacity in view of the fact that so much more of the cross-sectional area of the Tube tunnels is filled by the trains than is the case in the Channel Tunnel.
--Anonymous, January 07, '07, 20:52 (UTC).
Hi,
Does anyone know whether copper is more expensive than brass (because it's purer?) There's nothing about it on any of the wikipedia articles on either copper or brass or their talk pages. I couldn't find anything about it on the web.
Thanks, Bioarchie1234 17:40, 7 January 2007 (UTC)
What are some good techniques for sculpting and measuring a smooth sphere? I'm pretty sure there must be an ingenious way to do it, I just can't think of anything that won't be eye-measured and prone to distortions.
The case in question is that I have a round shape already, and I want to use sandpaper to finish the sphere (by hand, unfortunately that's all I have). I need it as close to a sphere as possible. — Kieff 17:58, 7 January 2007 (UTC)
Get two rectangular pieces of wood that are the same thickness as each other. Clamp them together to make a square(ish) shape. Make sure the sides are longer than the diameter of your sphere. Mark the centre of this square with a pencil, then, with pair of compasses, draw a circle the size of your sphere round this point. Take the two pieces of wood apart and cut out all the wood inside the circle, then file it or use sandpaper on it to get it perfectly circular. Glue the two pieces together and put your sphere in the circular hole. If you hold the square so it is parallel to a flat surface like a table, and so it passes through the diameter of the sphere, and then roll it around the table, you should be able to tell where it is bumpy because it will get slightly stuck. This might only work in principle, but it might work in practice too. I know you were looking for a more scientific method, but this is the best I could do! Hope it helps, if not, leave another message here or on my talk page. Bioarchie1234 19:04, 7 January 2007 (UTC)
[1] is the ball race method
Sorry if this doesn't come under science but I think it does. Anyway: Channel form efficiency and Hydraulic Radius, are they the same thing? I'm pretty sure they are but just need to double check. Thanks. 62.136.81.50 20:49, 7 January 2007 (UTC)
How do I measure how light pollution relates to the population of a certain area? And I'm doing this for a science project (hopefully you haven't seen me on another RD yet). —The preceding unsigned comment was added by Member ( talk • contribs) 21:46, 7 January 2007 (UTC).
Do animals with very good night vision detect colors in "more" brightness? From searching around, what I understand is that animals like owls have more sensitive rods that allow them to see more colors in the dark. But what does that really mean? Do owls see more colors but that the colors are still in low brightness/intensity, or do they somehow see the colors in more brightness (thus they can sense better contrast, etc.)? Thanks in advance 128.163.241.210 21:49, 7 January 2007 (UTC)
I have searched etc, and to no avail. I have to do a pie chart with % regarding the gas and water components in inspired air, and then in expired air. Do you have any ideas as to the answer, or where I could source it?
Munchkin MunchkinNZ 22:13, 7 January 2007 (UTC)
Doing some work with the VSEPR theory which is really not my field. Under VSEPR, what's the shape and bond angle of SCl2, and is it polar? I imagine that's a terribly simple question to you chemists out there, but I'd like to know. Thanks. Cool3 22:20, 7 January 2007 (UTC)
I tried looking it up, but I couldn't understand it. Especially, I can't understand how aldehyde: R-CHO is derived from the oxidation of a primary alcohol. In that context, what does oxidation mean? Thank. —The preceding unsigned comment was added by Legolas52 ( talk • contribs) 00:44, 8 January 2007 (UTC).
Oxidation is the loss of electrons. I'm not an organic chemist, but I would say that the primary alcohol loses electrons, thereby allowing it to bind to the R-group. BenC7 11:06, 8 January 2007 (UTC)
On Wikipedia's "Polystyrene" article, I noticed that it mentions that there are U.S. regulations prohibiting the use of solvents on styrofoam because it "de-foams" it. What is doesn't mention is what specific kinds of non-aqueas solvents de-foam styrofoam and why. Can anyone tell me (very specifically) why solvents have such an effect on polystyrene? EDIT: Sorry, I found it.—The preceding unsigned comment was added by 68.190.7.99 ( talk) 23:29, 7 January 2007 (UTC).
...why does Acetone dissolve it?
I once lived in San Francisco's Tenderloin in a 1920s Edwardian apartment building. Looking down on it from above, it was shaped like a capital I (although on preview I see that the font here is giving me a straight, stick-shaped I, as opposed to one with a discernable top and bottom). Two store-fronts and a basement constitued the ground floor. Facing the building from the street, on the left there was a maintenance door. If you went through it, you first went through a short passageway before emerging into an open area (by open I mean exposed to the sky). All the buildings' windows that looked down onto this middle area saw an entrance into the basement, access to the boiler, and the tail end of the trash chute, among other things. I've been to the City's official home page, I've gone through the Architectural glossary and more here on Wikipedia, poured over myriad other sites, and I can not, to save my life, put a construction, building, or architectural term to this open area. Mere curiosity isn't fueling my interest; rather, it's work-related. I realize my description is poor, but I hope it will be enough. Guesses, suggestions, site referrals and more - all welcome. Thanks. Wolfgangus 00:02, 8 January 2007 (UTC)
Coming from a position of total ignorance, and in light of your efforts, I'm uncomfortable saying this, but according to what I'm reading as definitions for a "well", it doesn't seem to qualify. Service well actually has an attractive ring to me, but in usage it may prove misleading. A while back I'd consulted a construction-management friend who suggested the term draftway but this didn't fit either.
Of course, it's entirely possible that it has no name at all, it's just a structural feature, incidental or otherwise ... but even something so insignificant as a nook is honored with a title, and the space I'm trying to name was probably 10 x 30 ft.
Perhaps I can convince someone in the City offices to glance at the blueprints. Surely they're on file and in some fashion a matter of public record. At any rate, thank you so much for your efforts; I'm grateful. Wolfgangus 19:25, 8 January 2007 (UTC)
Holy s**t. That's it. That's it! The diagram of the two tenements shows the general capital I shape, the opening, everything. Thank you so much; I can not adequately express my gratitude, but if I could, I could not possibly overstate it. Wolfgangus 03:39, 9 January 2007 (UTC)