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October 14

Sweat transmission of disease

What diseases can be spread by sweat in places like gyms or pools? I don't think many can other than skin infections such as herpes, HPV. What about blood borne viruses such as hepatitis or ebola? — Preceding unsigned comment added by 194.66.246.123 (talk) 09:37, 14 October 2014 (UTC)

It's difficult to claim "impossible to transmit" because if someone happens to have an open wound, lots of viruses and bacteria can enter the body that way and have a small chance of multiplying in the bloodstream. For most diseases, experts would say "extremely unlikely", and give evidence (where it exists) that there has been no recorded case of transmission by this means. Dbfirs 11:34, 14 October 2014 (UTC)

Today's Guardian newspaper says this: "What about sweat - for example could I get Ebola from using gym equipment? No. No one who had Ebola and was symptomatic, with intense muscle weakness and a fever in the early stages, would be well enough to go to the gym - and until they are symptomatic, they are not infectious. Sweat, anyway, is probably not a source of large amounts of virus - in fact, the World Health Organisation (WHO) says whole live virus has never been isolated from sweat." --Phil Holmes (talk) 12:39, 14 October 2014 (UTC)

Yes, sweat is a source for ebola and is often the route that infects caregivers and body washers in Africa. Corpses that have dried sweat or sweat that has contaminated surfaces is a path of infection. Other paths are blood, saliva, urine and feces. --DHeyward (talk) 13:42, 14 October 2014 (UTC)

• Source, please? For both. — Crisco 1492 (talk) 13:55, 14 October 2014 (UTC)

WHO on sweat NY times body washing . It's not HIV. It lives longer, in more fluids, and kills quickly. The problem is that the infection rate is currently exceeding the death rate by 2-3x and it kills within 3 weeks. That means the infection is doubling every 3 weeks or so. It infects at the rate as the flu but not as quickly but also more deadly at 50-70%. The Spanish Flu had the same infection rate (but much quicker) and much less fatality. HIV is manageable because it takes a long time to die though one person infects more than Ebola. The Flu infects the same as Ebola but acts more quickly and resolves more quickly. The math says that unless the infection rate falls below 1, it will inmfect at a sustainable rate as the flu but the incubation period makes it a 3-4 year world cycle instead of an annual cycle. It's unclear whether seasonal or animal populations will affect it. If it is like the flu, in 3-4 years it will sweep the world. --DHeyward (talk) 06:56, 15 October 2014 (UTC)

Allergy can be caused only by proteins?

Or it can be by other things that are not proteins? in this link there someone who told that there is an allergy for nickle. I'm not sure in this issue. 5.28.154.216 (talk) 17:45, 14 October 2014 (UTC) 5.28.154.216 (talk) 14:48, 14 October 2014 (UTC)

Allergies can be caused by many substances; Allergic contact dermatitis has nickel in its list. In fact, nickel was named the 2008 Contact Allergen of the Year. --Mark viking (talk) 20:15, 14 October 2014 (UTC)

The antibodies that cause an allergic reaction react only to larger molecules, but Ni can degrade proteins in such a way as to make those proteins allergenic. There are also such things as allergies to latex, which is not strictly a protein. I assume you read allergy and immune response? μηδείς (talk) 20:47, 14 October 2014 (UTC)

Strike that about latex, since is does contain proteins, and it is to that fraction that the allergic reaction occurs. μηδείς (talk) 17:00, 15 October 2014 (UTC)

Allergy can be caused by carbohydrates, see Alpha-gal allergy. Smaller molecules which may act as haptens are also relevant. Nickel has been mentioned. Other examples are isocyanates and various drugs (penicillin etc.). --109.189.65.217 (talk) 21:29, 15 October 2014 (UTC)

Peeing in a toilet

I've peed into a plastic container during medical exams etc, and like most people I note that pee tends to be dark yellow when you haven't had much to drink and lighter if you have.

So when I pee into the toilet, and my pee is dark yellow (visibly dark yellow during the flow), why doesn't the water in the toilet dilute the colour of the urine? It seems to be just as yellow when it mixes with the water as when its flowing. Shouldn't the water dilute it and make it less yellow?36.225.87.98 (talk) 15:02, 14 October 2014 (UTC)

The absorbance of many chemicals is in a narrow frequency band. Light of just that color is removed all but completely, while light of other colors never gets removed no matter how much is added. Of course, there's always a shoulder where more means darker, but the effect can be subtle. I didn't quickly find an absorption spectrum of urobilin online, though it is probably here, unless you count a ... very early version. (There may be aspects of the relation with urobilinogen and pH that I haven't appreciated) Wnt (talk) 15:21, 14 October 2014 (UTC)

A bowl of water reflects and refracts light. Pee is only yellow because its light is. In a way, it glows. Shine a small red light into your toilet, same deal. More red. InedibleHulk (talk) 15:54, October 14, 2014 (UTC)

Also note that a stream of urine is very thin, so even though it is darker, looking through such a small amount makes it look lighter, especially with a white background like a typical toilet bowl. The urine/water mix in the bowl is lighter, but you're looking through a lot more of it, and since you're looking at the light reflected off the bottom of the bowl, it actually passes through the water/urine mix twice. StuRat (talk) 16:09, 14 October 2014 (UTC)

Template:Cit journal has some spectroscopic information about uribilin, including possible pH and solvent effects. DMacks (talk) 17:57, 14 October 2014 (UTC)

• Of course there's also the question of the colour of a stream of bat's p!$$. 1m50s inμηδείς (talk) 18:17, 14 October 2014 (UTC)

Volcanism on the Moon! Consequences for colonization

This is really surprising (other references added at Moon): there are apparently 70 volcanoes that have been active on the Moon in fairly recent geologic times. The activity was found on the near side of the Moon, which apparently is warmer due to radioactive elements. There remain a few things I'm not clear on...

(1) Does the presence of this volcanism pretty much guarantee there are substantial amounts of water and gasses (especially CO2) trapped deep below the lunar surface, that would have separated from the magma proper?

(1b) The Moon, after all, is partly derived from the one planet where we know life exists. Could life exist in such spaces, or if absent, thrive if introduced?

(2) How do we know the "deep crust" of one side of the Moon is "several hundred degrees warmer" than the deep crust on the other?

(3) Can we get similar data for the shallow crust - specifically, do we know if there are any regions near the volcanoes where temperatures a short distance underground might be nice and comfortable? Also, our article doesn't give the data for what the temperature of the Lunar soil is once you get down beneath the day-night temperature variations.

(4) Are the volcanoes suitable for getting geothermal energy using known methods from Iceland, or new methods?

(5) If you get inventive and start drilling into magma pools, could you harvest interesting resources that might be hard to find on the Moon otherwise?

(6) Is there any chance of volcanic activity "fairly near to" the lunar polar craters where ice deposits exist? (Obviously the warmth is not directly compatible with the coldest spots in the solar system, so some commute is allowed!)

Wnt (talk) 15:08, 14 October 2014 (UTC)

(1b), whether it's Titan, Enceladus, Europa or whatever other current candidate bodies for ET life, exobiologists always come back to a few sources of inspiration: the dark cold lakes below the arctic ice caps are now thought to house entire ecosystems that do not derive their energy from sunlight , though there is of course still much unknown. The other favorite is the life at hydrothermal vents. Though things like Riftia get a lot of attention, they are highly derived worms. However, they depend on chemoautotrophic endosymbionts. These archaea are thought to be rather old, and can also be free-living, and take their nutrients from sulfides (?) that come out of the vents. All this is to say, sure, it is not unreasonable to think there are some extremophiles on earth that could thrive in certain local regions of the moon. All you'd need is some heat close enough to the ice to melt it, and some mechanism to churn things and cycle nutrients. If you want to get creative, throw in a little panspermia and recall that even "advanced" animals like water bears can survive in the cold vacuum of space...

All this is not to say any of this is likely, just that it is conceptually possible, based on what we know of terrestrial nutrient cycles and metabolic pathways of extant critters. SemanticMantis (talk) 15:51, 14 October 2014 (UTC)

Well, I'm not clear on the geological point of whether magma means water has to be around. I'm thinking water/gas emerge from super pressurized magma, yet get caught under some kind of dome and remain pressurized instead of escaping to space. Except that obviously a salt dome doesn't exist on the Moon, lacking among other things sedimentary rock, not to mention evaporites. I scarcely know the geology of the Earth, let alone this. Wnt (talk) 16:09, 14 October 2014 (UTC)

I don't know if magma has to entail water, but my reading of Lunar_water is that there is most likely some water there... SemanticMantis (talk) 16:51, 14 October 2014 (UTC)

4) I think geothermal energy would be difficult to use on the Moon. Typically lots of water is used to produce steam, and water is likely to be in short supply on the moon, and the little you have needs to be slated for human consumption. Solar energy might work well on the Moon for short-term energy needs, with no clouds or atmosphere to reduce the sunlight. However, solar panels might break down over time due to the harsh environment, or be covered with Moon dust. StuRat (talk) 16:23, 14 October 2014 (UTC)

Provided the water is properly recycled, it seems a worthwhile investment. Especially if more water can be from associated natural or man-made vents where gasses escape. Wnt (talk) 17:27, 14 October 2014 (UTC)

Solar cells should work fine on the moon for a very long time. They work well enough for long-term space missions. Moon dust should settle very slowly on them - what would make it rise to begin with? --Stephan Schulz (talk) 18:17, 14 October 2014 (UTC)

Dust is a likely explanation for the degraded performance of the lunar reflectors, see here:

"Dust is perhaps the most likely candidate for the observed degradation. Astronaut accounts from the surface and from lunar orbit, as well as a horizon glow seen by Surveyor 7, suggest the presence of levitated dust—possibly to altitudes in excess of 100 km, for which a lofting mechanism has been suggested by Stubbs, Vondrak, and Farrell (2006). The dust monitor placed on the lunar surface by the Apollo 17 mission measured large fluxes of dust in the east-west direction around the time of lunar sunrise and sunset— consistent with the electrostatic charging mechanisms described by Farrell et al. (2007). The main difficulty with the dust explanation is that electrostatic charging alone is not strong enough to liberate dust grains from surface adhesion. But mechanical disturbance seeded by micrometeorite and impact ejecta activity may be enough to free the already-charged grains. Whether or not dust is responsible, the supposed health of the reflector arrays has been used to argue that dust dynamics on the surface of the moon are of minimal importance. Our observations of the reduced reflector performance invalidate the invocation of reflector health in this argument." Count Iblis (talk) 18:35, 14 October 2014 (UTC)

Does China still have sparrows?

It's well known that during Mao's Four Pests Campaign, people killed off most of the Eurasian tree sparrows in China, with devastating consequences for agriculture. But I never see any followup: is China still bereft of sparrows, or have their numbers recovered? Misplaced Pages's article on them mentions that "thousands" of Passer montanus dilutus are present in eastern China during autumn, but "thousands" might be a small number in context. --Lazar Taxon (talk) 17:35, 14 October 2014 (UTC)

First thing to recall is that the Eurasian sparrow (Passer montanus) is a human commensal species; they love our cities. In most of their range, they are denser in human settlements than in "wild" habitat. I don't have time to search through all the citations included, but these three papers all talk a bit about sparrow populations in China . Reading the abstracts indicates there are plenty of sparrows around, but you'll probably have to dig through the citations to find good pre- Mao population estimates. Regardless of that comparison, I'm confident the sparrow population is not currently threatened or endangered in China. SemanticMantis (talk) 19:19, 14 October 2014 (UTC)

It's payback for the Norway rat from the far, near and middle east - but not Norway. --DHeyward (talk) 07:06, 15 October 2014 (UTC)

Anecdotally, yes. They're one of the most common birds I remember seeing in China's cities. --Bowlhover (talk) 08:07, 15 October 2014 (UTC)

Soil compaction

Normally, soil is compacted to maximise it's dry density and increase its strength. Moisture content can be increased to do this until the optimum moisture content is reached. But what happens if the soul becomes too saturated? Then does it lose its strength? — Preceding unsigned comment added by 82.132.245.233 (talk) 18:16, 14 October 2014 (UTC)

Check out Mud. ←Baseball Bugs carrots→ 18:29, 14 October 2014 (UTC)

What happens when there is too much water depends on the soil mineral content, grain size, slope, porosity, and many other factors. Soil mechanics gives an overview of this large topic. The specifics relevant to your question are at pore water pressure and bearing capacity. SemanticMantis (talk) 19:10, 14 October 2014 (UTC)

I fear my soul has become over-saturated. :-) StuRat (talk) 01:49, 15 October 2014 (UTC)

What are scientific opinions as to which part of the brain experiences qualia?

I do not want pseudoscientific opinion from geologists or sociologists—not a slight, but they are not the experts in the field with which I am concerned. Nor am I after scientific consensus because I am almost certain that there is none. Rather, I am after the opinion of neuroscientists that believe in the existence of qualia (some don't). Have any neuroscientists published their opinions on this matter?--Leon (talk) 19:41, 14 October 2014 (UTC)

These links may be of use to you . SemanticMantis (talk) 19:48, 14 October 2014 (UTC)

"Which part of the brain experiences" is a rather reductive question. You might look at The Rediscovery of the Mind by John R. Searle (and his other works, including the Chinese Room argument, as well as Stephen E. Palmer, author of Vision Science and his refutation of Locke's argument that qualia could be reversed without our being able to find it in natural trichromats. μηδείς (talk) 20:38, 14 October 2014 (UTC)

Searle is a materialist—he believes that qualia happen in the brain, and that this can be investigated scientifically, so he would approve of the original question. He has no personal opinion about the answer since he's not a neuroscientist. Neither does Palmer, as far as I can tell, so all of this is irrelevant to the original question. -- BenRG (talk) 23:08, 14 October 2014 (UTC)

Searle is not a reductionist, so he doesn't identify qualia with any specific part of the brain. He's certainly not a naive materialist. Palmer denies the standard notion that qualia are interchangeable. Both have plenty of interest to say on the topic. I'm tempted to say your objections prove the relevance of my comments, but I don't think they actually have anything whatsoever to do with my comments. In any case, they OP is invited to investigate the sources I have referenced, regardless of your OR. μηδείς (talk) 00:28, 15 October 2014 (UTC)

The point is that "consciousness of a person must be reducible to consciousness of cells/molecules/subatomic particles" and "consciousness can't be localized at all" are not the only two options here. Consciousness#Neural correlates suggests that the prefrontal cortex might be the seat of consciousness. That's a nontrivial partial answer to the original question, and it isn't at odds with anything that Searle or Palmer has written, to my knowledge -- BenRG (talk) 01:31, 16 October 2014 (UTC)

Consciousness#Neural correlates and Neural correlates of consciousness are relevant. -- BenRG (talk) 23:08, 14 October 2014 (UTC)

• This question presupposes the validity of what Daniel Dennett called Cartesian materialism. That article deals pretty directly with the question, and the range of scientific and philosophical opinions about it. Looie496 (talk) 15:56, 17 October 2014 (UTC)

Slow tire leak and tire pressure at speed vs sitting.

I have a very slow leak in one of my car tires, I have to top it off about every ten days. My question is that is there much of a difference in the pressure being applied on the tire, or the air in the tire, while my car is sitting vs while it is travelling at local speeds and vs highway speeds? I can't get over the mental picture of my tire "slamming" into the pavement harder as I go faster, even though this doesn't seem very logical. Thanks. Beach drifter (talk) 23:54, 14 October 2014 (UTC)

I would expect air to leak out faster when it's moving. The mechanical compression and decompression of the tire with each rotation is one reason, but the hotter air inside (as a result of friction), which then increases the air pressure, may be an even more important reason. However, you may only notice the loss of air when the tire cools and the pressure decreases. StuRat (talk) 01:52, 15 October 2014 (UTC)

Same problem and I can say that heat affects pressure more than use. The weight of the car doesn't change and pavement is relatively smooth. Temperature increase from friction as well as sunlight is a much larger effect than terrain. The warning light turns off during use. All anecdotal of course. --DHeyward (talk) 07:10, 15 October 2014 (UTC)

Nah, this is for the main part just a result of real leaks. If you exchange your tires the one very slowly leaking will still leak and the other will still not. --Kharon (talk) 12:52, 15 October 2014 (UTC)

October 15

water hands arthritis now

hello

i have recently been alerted to a claim by a fellow piano teacher that washing your hands immediately after playing piano or writing or typing reports or playing parappa the rapper or any other strenuous sort of activity with your hands may eventually result in arthritic symptoms because water erodes rock or something like that

although the rock water weathering thing part i doubt holds any credence is there any scientific basis for these claims? she said she heard it from dr oz some time ago and given his track record and the track records of other talking heads so to speak i would like to know if these claims are true or not thank ~Helicopter Llama~ 00:35, 15 October 2014 (UTC)

Misplaced Pages has an article titled Arthritis which lists different kinds of arthritis. Nowhere does it (or any articles on the specific types of arthritis) list cleaning your hands as a potential cause, even in relation to piano or video game playing. --Jayron32 01:57, 15 October 2014 (UTC)

Water does erode rock over time, but what the heck that has to do with erosion of the joints is beyond me, assuming you actually have flesh covering those joints, and thus the water doesn't drip directly on them. However, Dr Oz does often follow up otherwise sound advice with some such silliness as "If water can do this to the Grand Canyon, imagine what it could do to your joints". The only way I can picture hand-washing actually affecting the joints is if the water is hot or cold, and that warms or cools the finger joints. Of course, if that was the problem, simply changing the temperature of the water would be the obvious solution. StuRat (talk) 02:01, 15 October 2014 (UTC)

Bone is a living matrix with a calcite substrate. It doesn't "erode" except for osteoporosis which is hormonally and nutritionally mediated, see calcium and Vitamin D/ Otherwise, see your general practitioner who will professionally advise you whether this bee ess is bee ess. μηδείς (talk)

Umm, "bone erosions" is the medical term for the bone destruction that occurs in rheumatoid arthritis, see for example Schett G, et al, Bone erosion in rheumatoid arthritis: mechanisms, diagnosis and treatment. Nat Rev Rheumatol. 2012656-64. PMID 23007741. --109.189.65.217 (talk) 19:16, 16 October 2014 (UTC)

That piano teacher sounds like he heard an old wives' tale in the distant past and somehow stuck with it. ←Baseball Bugs carrots→ 08:06, 15 October 2014 (UTC)

The explanation given is certainly nonsense - but that doesn't mean that it's necessarily bad advice. I could imagine that washing your hands cools down the muscles - and perhaps that has a deletrious effect? After all, we use hot and cold treatments to help muscle pain and stiffness and to control inflammation. SteveBaker (talk) 14:32, 15 October 2014 (UTC)

So he might be right for the wrong reason? If so, the next step would be to see what doctors (other than Oz) recommend for easing arthritic pain: hot vs. cold. ←Baseball Bugs carrots→ 14:37, 15 October 2014 (UTC)

To be clear, I'm not saying that this is good advice - I'm merely pointing out that it might be. For sure, erosion of rock by water has absolutely nothing to do with it...but that doesn't mean that the advice doesn't work. It might (for other reasons) be good advice or it might be completely terrible advice. SteveBaker (talk) 05:05, 16 October 2014 (UTC)

I like to point out that Dr. Oz has had the distinction of "winning" two Pigasus_Awards, for his general quackery and "refusal to face reality". See also the description here . This does not mean the man is incapable of making true statements, but to me it means that most things he says should be treated with a healthy dose of skepticism. SemanticMantis (talk) 16:35, 15 October 2014 (UTC)

My family and its obvious genetic traces are legion. But really, I completely fail to see what the problem with "refusal to face reality" is. I checked with my 387 cousins and they're all as mystified as I am. -- Jack of Oz 08:59, 16 October 2014 (UTC)

The thin layer of fat in your skin ought to keep any water on your joints from eroding them. If your joints were vulnerable to water damage because "water erodes rock," then you'd better stock up on scissors... because everyone knows "rock breaks scissors." Of course, you could protect yourself from water-mediated joint damage by covering your joints with paper strips when you wash your hands, because "paper covers rock" (someone stop me... ) loupgarous (talk) 16:28, 17 October 2014 (UTC)

Why do the nuts usually end up on the top of the muesli?

Shaking and stirring the container only mixes the muesli evenly for a while, the nuts seem to be able to "float" to the top. Roger (Dodger67) (talk) 11:38, 15 October 2014 (UTC)

That's a classic question. Please see Granular convection.--Shantavira| 12:08, 15 October 2014 (UTC)

.. aka the Muesli effect (same article). AndrewWTaylor (talk) 12:19, 15 October 2014 (UTC)

LOL @ Muesli effect. You may want to read about Rheology, the "science of the flow of matter" to understand how solid matter can to some degree also "float" aka behave like fluid matter. --Kharon (talk) 12:45, 15 October 2014 (UTC)

Thanks. It's really called the muesli effect.... :)

The nuts will normally be well mixed to start with because the dispenser will have settled into a steady state, shaking and stirring unmixes them. You might also like to look the pictures of circular mounds of stones at frost heavingDmcq (talk) 14:42, 15 October 2014 (UTC)

One interesting counter example is Raisin Bran cereal. They noticed that shipping tended to unsort the mix, and raisins fell to the bottom. So now they add raisins after the box is ~50% full of pure flakes, so that the raisins tend to spread out evenly during shipping. Can't find an online ref, this is described in the book "Why Do Clocks Run Clockwise, and Other Imponderables", by David Feldman. SemanticMantis (talk) 16:30, 15 October 2014 (UTC)

That's clever, thanks for that. Dmcq (talk) 19:37, 15 October 2014 (UTC)

...AKA Brazil nut effect. See here for a nice video demonstration, and links to some relevance for asteroids such as 25143_Itokawa. SemanticMantis (talk) 16:25, 15 October 2014 (UTC)

structural columns

Is the column in this picture supporting any load from the ceiling or building structure. I don't think it is. It looks like its taking no load. The only possible load on it is axial compression just from it being attached to the sides in my opinion. I don't think it's taking any load from the ceiling. Am I correct? http://m.english-heritage.org.uk/about/news/kenwood-house-restored/

The columns at the right hand end in the first photo on that page?

They might just be decorative - but that long pink and white beam might need to be supported in the middle, in which case, they'd be structural. Although the beam isn't under vertical load from structure above it, it does have some weight of it's own - so it's remotely possible that it's really a relatively thin beam that's coated with a bunch of heavy plaster-work decoration. If the beam sagged down a bit, maybe it would bend enough to crack the plaster-work decoration.

I'd guess that the columns are purely decorative though. The beam across them might also be decorative - but if not, it's probably in tension, preventing the walls from moving outwards under the forces from the domed ceiling behind it.

SteveBaker (talk) 14:28, 15 October 2014 (UTC)

I agree with Steve that the beam, if anything, is in tension and if it needed supporting for weight, it most likely would need it from the ceiling so everything is in tension and the weight is transferred to the walls. But the other clues that it's decorative seem to be replication of Greek/Roman Golden rectangle proportions (on edit, our Golden ratio has more. In addition after reading the article on the picture, the original architect Robert Adam returned architecture at the time to the more classical Golden ratio era and developed the Adam style). If the height and width ratio of all the different rectangles created in that room aren't identical, I'd be very surprised (architect should be fired). The height to the beam relative to the width of the room, the height of the columns relative to the space between them, the H/W ratio of windows, bookshelves, etc, are all the same though some are horizontal, some are vertical. Using the proportions in art and architecture are very prevalent and our article sadly lacks more than just the mathematical formulation. Years of watching Donald Duck in Mathmagic Land did not go to waste (though I still can't play billiards). Watch it as it never gets old and will show lots of examples. --DHeyward (talk) 15:24, 15 October 2014 (UTC)

This question was misfiled at the top of the page, so I've moved it down. Wnt (talk) 13:56, 15 October 2014 (UTC)

After use of electricity unused current returns back through neutral wire which

Is not used later,can we reuse that returned electricity of neutral wire again???

Poster was Diwas pandey

Electricity is made up of electrons in a conductor, which move much like water flowing down a hill. But instead of the height above ground, it is the voltage that matters. When electrons return to ground, they are like water that has flowed down the hill. To get energy out of them, you would have to let it flow even further down (to a positively charged electrode) or pump it back up again (with a battery, for example).

It is possible to shock yourself on a ground wire if you disconnect it from the breaker box. This is because a ground wire is not a ground wire if it isn't grounded. You can connect any number of devices one ground wire to the next (in series) - however, the voltage each receives is reduced, which in many cases means they won't work. That is like taking a fast-flowing stream and giving it a long slow way to go downhill instead - it becomes more sluggish. Wnt (talk) 14:03, 15 October 2014 (UTC)

Ideally ground current is zero. There's no reuse as the net flux of current is zero (except for things that charge up). In the U.S. there are single phase 120V/240V and three phase 120/208V systems (there's others but these provide 120V for common outlets). Ideally, the load is balanced across the 240V or 208V terminals which has the effect of reducing current in the neutral wire preferably to zero. The neutral wire only carries the net difference. This is important for a number of reasons including IR drop (which raises neutral voltage above ground) and ground loops. Balancing loads also allows reduced neutral wire sizing and shared neutrals. By code, the neutral wire is only bonded to ground at the service entrance. --DHeyward (talk) 14:59, 15 October 2014 (UTC)

ebola in animals

Can ebola infect a cat? if it can, would the cat show symptoms? By the way i am not asking for advice and i don't have any immediate concern about my health or any cats, but it does alarm me to see ebola in America.

According to the CDC , there is presently no evidence that dogs or cats exposed to Ebola will either become sick or spread the virus. No sick pets have been documented in West Africa or anywhere else. Previous work has indicated that dogs can be affected by Ebola if they have close contact with infected people or animals (e.g. eating corpses), but that the dogs do not seem to develop any apparent symptoms. At present, it is assumed that in the absence of symptoms dogs are unlikely to spread the disease. So dogs and cats are not at high risk as far as we know. However, it may be worth noting that pigs will catch the disease, become symptomatic, and spread it highly effectively . Dragons flight (talk) 15:32, 15 October 2014 (UTC)

There was a case recently with a dog which was indeed euthanized to prevent spread of Ebola; here is a story about how animal rights people collected a third of a million signatures to save the dog. (Gee, I wonder if anyone tried a petition to save the 20,000 Liberians...) Apparently the isolation scheme of leaving the dog with 33 pounds of dog food and a bathtub of water wasn't thought to be good enough. (Feeling glad I'm not a landlord) Wnt (talk) 19:50, 15 October 2014 (UTC)

Yes, Spain destroyed a dog without even attempting to test whether it had Ebola. On the other hand, Dallas has isolated the dog belonging to the sick nurse there and taken steps to provide for its long-term care, with no plans to euthanize it. Dragons flight (talk) 21:25, 15 October 2014 (UTC)

Are they going to simply let it leave isolation once testing shows no signs of Ebola or will they continue to keep it in isolation (perhaps with further testing) until sufficient number of days have passed that they no longer consider it a risk? Nil Einne (talk) 12:23, 16 October 2014 (UTC)

Some searching found which says the dog will be kept in isolation for 21 days and they may not even bother to test it depending on what health authorities suggest and that decomination procedures will be used to dispose of faeces or other material from the dog found in the house. I presume, but it isn't clearly stated, that similar rules will be applied to the dog one isolation. That source also includes pictures of how the dog was taken from the house although the level of caution may be more to do with the house in general that just the dog.

Anyway it seems that the Spanish authorities and Dallas authorities views on this matter aren't actually that different as both seem to consider that the risk from the dog, however low, requires careful management and that testing won't be sufficient to allay concerns. They seem to primarily differ in their views on whether resources should be spent on caring for the dog, and perhaps also on whether it's an acceptable risk to expend that effort (although I'm not so sure on this one, it may be simply the first). It's possible differing views on the rights of the owners (which for better or worse is largely how the human-animal relationship is treated in law) also come in to play . Despite well meaning comments like, it's clearly more complicated than simply differing views on the worth of animal life since both allow the widespread raising and killing of animals for food.

Nil Einne (talk) 13:20, 16 October 2014 (UTC)

Woman having a penis

I understand that a man can have a vagina if he remove or had his penis cut due to cultural or other reasons. But, how does a woman get a penis or is it a man with a penis get a breast transplant or implant? If a man does get a breast implant and doesn't remove his penis and dates a man or marries one, would that make them gay? I am confused on how to understand this transsexual and transgender issue.

See Sex reassignment therapy. Ruslik_Zero 19:25, 15 October 2014 (UTC)

Phalloplasty and Metoidioplasty speak to the surgical processes you inquire about in your first question; in common parlance, these are called "female-to-male" sexual-reassignment surgeries, and a person undergoing these procedures (typically in conjunction with a form of hormone replacement therapy) is known as a trans man, just a person "transitioning" to a female identity is known as a trans woman. A transgendered woman (born male) may choose to undergo hormone therapy alone, they may keep the genitalia they were born with but undergo surgery for breast implants or to create other feminine secondary sexual features, or they may have full sexual reassignment surgery, but in most cases they are likely to identify as female and are said to suffer from gender dysphoria, the condition of perceiving the sex of one's body as differing from the gender that feels natural to them. As to the sexual orientation of two genetic males engaged in an intimate relationship, one of whom identifies as female but has not undergone full sexual reassignment, that's largely a matter of perspective, and opinions vary widely both from those within such relationships and without. Generally, and increasingly, it is considered most tolerant to let those inside such relationships to decide for themselves what the combination of gender identities and physical sexes involved mean about their sexual orientations. It's understandable that some people unfamiliar with these concepts can be confused by the many overlapping and not-always consistent terminology, but the key to understanding the many different perspectives on the matter is to first understand the distinction between sex and gender and to not get too hung-up on nomenclature, whenever the situation allows you to avoid it. Snow talk 08:07, 16 October 2014 (UTC)

Smoke detector placement and orientation

Smoke detectors are commonly mounted on the ceiling, facing downward. But do they actually have to be?

Wouldn't smoke detectors work fine as long as they're facing toward the open air, away from the surface they're against? For example, wouldn't a smoke detector work just as well against the wall, facing sideways away from the wall, or on the floor, facing upwards?

If placed on a bookshelf, does it matter whether the smoke detector is placed on a high shelf or a low shelf, as long as it has open air access?

—SeekingAnswers (reply) 19:53, 15 October 2014 (UTC)

This guide from the National_Fire_Protection_Association says that wall mounting is OK, but they should be within 12" of the ceiling . The reason is fairly simple: smoke rises. Consider a case where there is a small fire on the floor in a corner, and the smoke detector is in the opposite corner. It will trigger sooner if placed near the ceiling, compared to being placed near the floor. SemanticMantis (talk) 20:57, 15 October 2014 (UTC)

And from this instruction sheet for a smoke detector "Smoke, heat and other combustion products rise to the ceiling and spread horizontally. Mounting the detector on the ceiling in the centre of the room places it closest to all points in the room." In a fire a few minutes warning can be the difference between survival and death - go with the manufacturer's recommendations for their product. Richerman (talk) 21:03, 15 October 2014 (UTC)

Near doors in bedrooms is best. ceiling elevation changes are also places where smoke detectors should be placed. In residences, smoke detectors are not really necessary in the center of rooms as fires rarely can develop from any place. Rather, they are placed between points of ignition and people and along their escape routes. Hallways, bedrooms, etc, are where most smoke detectors are placed. usually within 3 feet of a door and within 12 inches of the ceiling. Commercial buildings have them distributed throughout mostly as early warning for Fire Department. --DHeyward (talk) 01:02, 16 October 2014 (UTC)

Why is Germany's power-to-gas so far ahead of the English-speaking world's?

Please compare http://de.wikipedia.org/Power-to-Gas with http://en.wikipedia.org/Power_to_gas

Why is the former so much more well-developed? 76.88.167.15 (talk) 21:16, 15 October 2014 (UTC)

Because Germany is technology world leader in many sections of that field. Like for example Type 212 submarines. Also german automotive and mechanical engineering industry is huge and thus takes a big share in the worldwide struggle to transite traffic and industry away from Petrochemistry. --Kharon (talk) 21:36, 15 October 2014 (UTC)

The OP might be asking about the relative development of the two articles in those two language editions of Misplaced Pages, rather than the relative development of the actual technology in the two countries. Since Misplaced Pages is edited by its readers, the amount of development of specific articles generally depends on the popularity of that particular language edition, as well as how important some particular topic is within the culture of societies that use that language, but is also subject to randomness based on a few editors being particularly interested in some topic. Because the English Misplaced Pages has the most viewers and readers, it also has the most editors, so in general, English Misplaced Pages articles are better developed than corresponding articles in other language editions, such as the German Misplaced Pages, but in this case, it appears that a few German editors care greatly about the topic and so have developed the article more. —SeekingAnswers (reply) 22:37, 15 October 2014 (UTC)

You are free to copy material between the different language editions of Misplaced Pages, however you must acknowlege in the edit summary that is was copied from de: If you do not speak German well, you can use machine translation to assist, but you must tidy the resultant English into grammatically correct prose. CS Miller (talk) 15:33, 16 October 2014 (UTC)

I suspect that it has to do with the reunification of East and West Germany. Many of the East German power plants would have been heavily polluting and poorly maintained, and also perhaps incompatible with West German standards, necessitating scrapping those plants and starting fresh. This is a very expensive process, but does provide the opportunity to incorporate the newest technologies. In most of the English speaking world, the situation was not as dire as East Germany, so the temptation was not to scrap outdated plants, but just keep them going with minor upgrades. However, when all the new German plants near the end of their life cycles, they will be in the same situation, where minor upgrades can keep them limping along, at less cost than total replacements. StuRat (talk) 16:00, 16 October 2014 (UTC)

How to convert an arbitrary monochromatic light (its wavelenght) to a displayable trichromatic light (that is an sRGB screen)?

Is there some linear interpolations formulaes which approximate this conversion (as exact conversion is not possible) while complying with the en:Misplaced Pages:No original research? ... — Preceding unsigned comment added by 77.199.96.124 (talk) 22:41, 15 October 2014 (UTC)

If you read the sRGB article, or any other resource on this topic, you will notice: the outer curved boundary is the monochromatic locus. That means that a wavelength can directly map to the XY colorspace. The formula for this curve is specified by any of several standards; for example, the CIE 1931 standard specifies tristimulus parameters. Then you can use the standard transform to the RGB color space of your choice, i.e. sRGB.

So: if you had pure monochromatic light, you would first compute its corresponding X,Y value by multiplying by the standard tristimulus functions. If you want to over-mathematicalize things, this computation is a weighted integral in which you are premultiplying the stimulus standard function with a dirac delta at the monochromatic light wavelength. In other words, three values are obtained by evaluating the three standard stimulus functions at that wavelength. Next you would multiply that 1x3 matrix by one of the standard 3x3 color space conversion matrices to obtain an "R/G/B" triplet.

Here is some reference code, RGB VALUES FOR VISIBLE WAVELENGTHS by Dan Bruton of Texas A&M / Austin State University Observatory. This code is written in the FORTRAN language, and was the standard model for the MATLAB MuPAD toolbox implementation of RGB::fromWaveLength. His model does not incorporate standard tristimulus functions to approximate human perception; in other words, it is a radiometric, rather than photometric, model.

In actual practice, there's a lot more guess-work and standards-fudging than you might expect! Nimur (talk) 02:35, 16 October 2014 (UTC)

The steps are:

1. Convert from the wavelength to XYZ using color matching functions (as found here, for example) and then to linear sRGB using the matrix multiplication from sRGB#Specification of the transformation.
2. Somehow convert those RGB coordinates into RGB coordinates in the range .
3. Convert that to (nonlinear) sRGB using the formula from the sRGB article.

Steps 1 and 3 are easy. Step 2 is hard because there's no right way to do it. At least one of the three RGB coordinates you get from step 1 will be negative. You can fix that by adding white, i.e. by adding an equal amount to all three coordinates. If you add the minimum amount of white (so that the smallest coordinate is 0.0), then normalize so that the largest coordinate is 1.0, the result will be fine for individual hues, but it will make a weird-looking spectrum with artificial lines and brightness gradients because the amount of white and the normalization factor vary wildly. If you want to display the whole spectrum, you will probably want to add a fixed amount of white across the whole range, and scale by a fixed amount, but this will lead to boringly desaturated colors.

the function that Nimur linked looks very inaccurate and I wouldn't use it if you care about getting the hues right. There's no such thing as a "radiometric" conversion to sRGB. -- BenRG (talk) 17:02, 16 October 2014 (UTC)

Well, BenRG, perhaps you disagree with the utility of that equation; but there does exist such an equation, and it is used by one of the most prominent vendors of image processing software, a package that is used by many researchers across the globe... this specific equation has been published in peer-reviewed journals with applications ranging from color image processing for video compression to hyperspectral imaging research; it has been recognized by the IEEE and the SPIE; it has been adopted by commercial vendors and open-source software...

Presumably, though, you are able to determine that "there's no such thing," and that its accuracy is insufficient for any purpose, so I guess I'll defer to your extensive expertise in the field.

Nimur (talk) 18:37, 16 October 2014 (UTC)

You can look at Bruton's code and at the definition of sRGB and see that the code is wrong. The mathematics isn't very difficult. Most obviously, it puts the RGB primaries (#F00, #0F0, #00F) at 645nm, 510nm, and 440nm, while the correct locations (for sRGB primaries and D65 white point) are roughly 610nm, 550nm, and 465nm, so the hues are actually very far off. The code doesn't claim to be based on sRGB, and in fact predates sRGB (which was published in late 1996), but I don't see how it could be accurate with any red-green-blue primaries. 510nm is more teal than green, and 440nm is violet.

I do see evidence that this function is very widely used, to the point that it's hard to find spectral images that show the correct hues, but this one seems to. This chromaticity diagram is also accurate. (Many other chromaticity diagrams on Commons and the web are incorrectly green at the top, such as this one, but they're otherwise pretty accurate.)

You wrote "His model does not incorporate standard tristimulus functions to approximate human perception; in other words, it is a radiometric, rather than photometric, model." That doesn't make sense, and I think you made it up. That was what I was trying to say, more politely, when I said that there's no such thing as a "radiometric" conversion to sRGB. -- BenRG (talk) 21:25, 16 October 2014 (UTC)

Why not simply use Yxz and let the device apply whatever transforms it needs to display the data containing the brightnesses and chromaticities? Count Iblis (talk) 20:10, 16 October 2014 (UTC)

October 16

Greased sword

There is a sword fight, one person gets slashed in the chest and has a huge gaping wound. What would happen if the sword and the person's chest were oiled and slippery, would the sword cut less? — Preceding unsigned comment added by 88.115.38.169 (talk) 17:16, 16 October 2014 (UTC)

Only maybe if the blow was struck by the side of the sword rather than the edge. For a gross comparison, the oily surface of a cooked bird doesn't seem to stop the carver from getting through it. ←Baseball Bugs carrots→ 17:32, 16 October 2014 (UTC)

I agree, it seems unlikely that it would make any difference whatever unless it was an extremely glancing blow. Do an experiment - get an egg and a knife...whack the egg hard with the sharp edge of the knife...what happens? Cover both with olive oil...do it again. Does it make a difference? No? I didn't think so. SteveBaker (talk) 20:08, 16 October 2014 (UTC)

A greased sword should go through a bit quicker, but not a significant bit. Remember, blood is already slippery. Once the sword's in, it's lubed. In boxing and MMA, they put Vaseline on fighter's faces to prevent friction and tearing, and the same idea would help somewhat against clubs and such, but swords (and elbows) work too finely. InedibleHulk (talk) 13:13, October 17, 2014 (UTC)

How many molecules build the cell? (not types, but in general)

What is the amount of the molecules that the cell made of? 5.28.154.216 (talk) 19:03, 16 October 2014 (UTC)

What type of cell? Crystal cell unit? Bacterial cell? Eukaryote cell? What species if one of the latter two? What tissue? --OuroborosCobra (talk) 19:07, 16 October 2014 (UTC)

It is unlikely that an exact answer can be determined for any specific case; but we can estimate to order of magnitude. We have a few entries in our article on orders of magnitude (numbers), with citations: the human body consists of roughly 10 cells, and 10 atoms. With a little arithmetic, you can estimate an average number of atoms per cell. This leaves the original question unanswered: how many atoms are in each molecule? Well, the answer is very difficult, because there are some molecules (like water) comprised of very small numbers of atoms... water has three atoms. There are other molecules, like DNA, which is commonly treated as a "single molecule," containing millions of nucleotides (potentially hundreds of millions of atoms per molecule). The arithmetic mean value of atoms-per-molecule is not very useful!

So, we probably have a few trillion atoms in a typical human cell (plus or minus a few trillions, or maybe even plus or minus ten trillions or a hundred trillions); and the number of distinct molecules made from that many atoms could be anywhere from a few million to a few hundred trillions. This is somewhat imprecise, but it's not easy to improve the precision without relying on a lot of difficult and tenuous estimations!

Nimur (talk) 19:38, 16 October 2014 (UTC)

Quick answer: twenty billion.

OK - that's going to make people wonder - so I'd better explain how I got there:

It's very hard to generalize - but I think you're probably asking for an extremely approximate answer (which is all you'll ever get!). The smallest known cells (some bacteria) are only 200 nanometers across (there are yet smaller things at 20nm - but there is much debate over whether they are alive...or even exist at all!). The largest cells known are the nerve cells of a giant squid that can be 80 feet long...and the heaviest is an unfertilised ostrich egg. But assuming we're talking about your typical run-of-the-mill human cell, what can we say?

• According to this paper, a "typical" human cell weighs 10 grams.

• This image has the percentage of different molecules in a bacterial cell - it's probably not THAT much different from a human cell - so let's guess that human cells have about the same distribution...that might be a bad guess - but we're only after a very rough answer.
  • DNA is only 1% of the cell by weight - and DNA molecules are huge - so it's not contributing many molecules...so let's ignore it
  • Same thing could be said for the proteins, RNA and other long-chain molecules. They don't make up much of the mass - and they are relatively big molecules.
  • Water is 70% of the mass of the cell - and it's made of very light molecules...so it's going to totally dominate the molecule count.

• So it's probably fair to say that the total number of molecules is pretty close to the number of water molecules - at 70% of the mass of the cell. The other 30% doesn't contain many molecules - because, those are mostly REALLY gigantic molecules!

• The molecular weight of water is 18 - so 18 grams of water is 6x10 molecules (Avagadro's number).
• 70% x (10) x (6x10) / 18 = 23,000,000,000

So: the total number of molecules in a human cell is probably a little more than the number of water molecules, which is around 23,000,000,000 - which we'd better round to 20 billion.

Or a few million...or trillions of quadrillions...depending on what cell you're measuring.

SteveBaker (talk) 20:00, 16 October 2014 (UTC)

October 17

Giving blood to lose weight

If you give blood, will your body burn more fat in response to replace the lost blood? ScienceApe (talk) 02:26, 17 October 2014 (UTC)

Yes, indeed. Replacing a pint consumes about 650 calories. Not much, but every little bit helps. Dominus Vobisdu (talk) 02:30, 17 October 2014 (UTC)

Cody McKenzie recently did that to make weight for a fight. According to a doctor, it's not recommended, but not a terrible idea, in the very short-term. Of course, in that case, it had little to do with burning fat, just that a pint of blood weighs a little over a pound. InedibleHulk (talk) 13:23, October 17, 2014 (UTC)

Right, runners and wrestlers also sometimes also use more conventional excretion (defecation, urination) to reduce weight before a race or a match. BTW, Dominus, your claim makes sense, but do you have a reference for that? SemanticMantis (talk) 14:53, 17 October 2014 (UTC)

In general one should not assume that "uses calories" is the same as "helps you lose weight". For example, in winter, you use more calories just staying alive than in summer, because you need to generate more heat. However, most people gain rather than lose weight in the winter, presumably because they also eat more. Unless both your caloric income and outgo are otherwise rigorously controlled (which is almost never the case) it is very difficult to predit the effect of a single change. --Trovatore (talk) 14:57, 17 October 2014 (UTC)

And don't forget the downside. Giving blood causes you to lose iron, and possibly other nutrients. There is a limit to how quickly your body can absorb iron from your diet, so this imposes a limit on how much blood you can give. (You can also have iron infusions (IV's), but this has it's own negatives.) Also, blood cells can only be rebuilt at a certain rate, even if enough iron is present. And if you happened to suffer an injury and bleed right after having given lots of blood, you might well bleed to death sooner.

The doctor in that McKenzie article says it's about eight weeks for red blood cells to come back. For what it's worth, he looked weak and slow in that fight, though that may have had more to do with fishing instead of training. InedibleHulk (talk) 15:45, October 17, 2014 (UTC)

Something I've thought of, for the morbidly obese, is something like hemodialysis, but where they remove unhealthy nutrients from the blood, like bad fats, bad cholesterol, & excess sodium and sugar, and perhaps increase good fats, good cholesterol, and other needed nutrients. If the person was already on dialysis for kidney failure, this wouldn't pose much additional risk, and could offer quite a benefit, part of which would be losing weight. I think I will ask a Q about this. StuRat (talk) 14:56, 17 October 2014 (UTC)

Effect of oxygen percentage vs. partial pressure on flammability

I have always assumed that the flammability of a give material was a function of the partial pressure of oxygen in the atmosphere it was exposed to and not the strict percentage of oxygen. For instance, I would have thought that a material would be more or less equally flammable in a 21% O₂ 1.0 atm environment as it would be in a 10.5% O₂ 2.0 atm hyperbaric one or a 42% O₂ 0.5 hypobaric one.

But this NASA document, Recommendations for Exploration Spacecraft Internal Atmospheres (Lang, et. al., 2005) says:

By contrast with human respiration that depends primarily on oxygen partial pressure in the atmosphere, materials flammability depends strongly on oxygen concentration (volume percent) and to a lesser extent on total pressure. (pg 11)

but doesn't appear to go any further into the subject.

Where can I learn more about this? I'd like to read about the physics behind this and see some "Constant Flammability Curves" showing pO₂ vs. %O₂ for various materials.

Oxygen#Combustion and other hazards states:

The fire that killed the Apollo 1 crew in a launch pad test spread so rapidly because the capsule was pressurized with pure O₂ but at slightly more than atmospheric pressure, instead of the 1⁄3 normal pressure that would be used in a mission.

which supports my earlier understanding.

thanks fireman stow -- 190.58.249.28 (talk) 04:38, 17 October 2014 (UTC)

Actually, it does not support your previous understanding, it's just consistent with it. In that case, both partial pressure and concentration were much higher than in normal air. I suspect one reason why concentration is important is because all of the gases in the mixture help dissipate the heat. So adding e.g. more nitrogen will make the flame burn, effectively, colder, since there is more gas available to carry away heat from the flame. Chemical reaction are highly dependent on temperature. Also, the oxygen must be able to come into contact with the fuel. If there is more inert filler gas, that may happen less frequently. To use a mechanical analogy, it's a lot harder to get to the buffet if the room is full of people, even if most just stand and talk. --Stephan Schulz (talk) 14:51, 17 October 2014 (UTC)

Yes, "consistent with" is what I should have said. And the Apollo 1 statement is not inconsistent with the NASA document either, as while the latter says that percentage is the stronger effect, it does mention that the partial pressure does have an effect, albeit a lesser one.

Your temperature effect makes a lot of sense to me.

Your crowded room analogy is an interesting one. In a steady state situation where the oxygen is not being consumed, the rate at which a particular type of gas molecule impinges on a unit area is strictly a function of the partial pressure of that species, and fully independent of the partial pressures of other gas species. It might take you longer to get to the buffet, but it will take longer to get away once you are there. But things change when a significant fraction of the local oxygen is consumed and must be replaced. The the additional inert gasses will affect the mean free path and diffusion rate of the oxygen, and thus the rate at which it can feed the fire. Very interesting! I wonder how strong this effect is, and if it might be more pronounced in micro-gravity where convection is not in play.

Thanks, Stephan, for two promising mechanisms. I wonder what their relative strengths are, and I would still love to see some numbers or a graph showing the magnitude of the effect on flammability of pO₂ compared to %O₂. -- 190.58.249.8 (talk) 01:07, 18 October 2014 (UTC)

Dialysis plus

Something I've thought of is something like hemodialysis, but where they remove unhealthy nutrients from the blood, like bad fats, bad cholesterol, & excess sodium and sugar, and perhaps increase good fats, good cholesterol, and other needed nutrients. If the person was already on dialysis for kidney failure, this wouldn't pose much additional risk, and could offer quite a benefit.

So:

1) Is this possible ?

2) Which baddies could be removed ?

3) Is anyone doing it ?

4) Is anyone researching it ?

Thanks, StuRat (talk) 14:56, 17 October 2014 (UTC)

Loyola Medical Center has actually developed a procedure called "LDLapheresis" for patients whose "bad cholesterol" won't respond to diet, exercise, the statin drugs or harsh language. Once every two weeks, a patient spends two to four hours connected to an apheresis unit that removes 70-to-80 percent of the patient's LDL (bad) cholesterol, then returns the blood to the body. The good HDL cholesterol is not removed. here's the Science Daily article loupgarous (talk) 16:37, 17 October 2014 (UTC)

Excellent, but the risk of sepsis might outweigh the benefits, if that's the only baddie they remove and the patient wasn't already on dialysis (although they seem to restrict it to people with extremely high bad cholesterol and/or who have had heart attacks). StuRat (talk) 17:16, 17 October 2014 (UTC)

Plasmapheresis would seem to be one method to remove the baddies:

1) Remove the blood.

2) Separate out the plasma from the cells, by centrifuge.

3) Discard the plasma, which contains most of the baddies.

4) Mix replacement plasma, with the proper level of nutrients, with the cells removed in step 2.

5) Return the remixed blood to the body.

Now I realize there are a lot of risks involved, so this might not be practical for everyone, but perhaps just for current hemodialysis patients. Also, are we able to synthetically manufacture blood plasma, or must we rely on donors ? StuRat (talk)

Blood_plasma#Synthetic_blood_plasma -> Simulated_body_fluid, googling /synthetic plasma/ led me to Blood substitute, as well as . The answer seems to be we can synthesize materials with many properties of plasma, but it's not plasma. /Plasma extender/ and /plasma volume expander/ are other key phrases. SemanticMantis (talk) 18:39, 17 October 2014 (UTC)

• This sounds like an incredibly expensive way to damage red blood cells and waste plasma that could better be used for saving the lives of trauma victims. It reminds me of various world leaders who have tried to extend their lives by consuming the blood of virgins, in one way or another. If, of course, someone like Bill Gates, who has never stolen money from anyone, wants to buy blood to address some hypothetical problem, a laissez-faire system wouldn't stop him. μηδείς (talk) 20:47, 17 October 2014 (UTC)

• Doesn't sound very expensive under my scenario, where they are already in for hemodialysis. It would just be one more machine hooked in. It might even save money, if this method replaces, and is cheaper than, the current methods used to filter out waste products. The current methods also miss some toxins, like one you get from eating star fruit. StuRat (talk) 21:08, 17 October 2014 (UTC)

My understanding is that dialysis costs several (i.e., more than $4) thousand a month. Even insulin treatment costs a tenth of that. I won't argue, we'll simply have to settle for sources on this one. μηδείς (talk) 23:54, 17 October 2014 (UTC)

Yes, dialysis is expensive, but you seem to be ignoring the fact that I've repeatedly said I'm talking about patients who are ALREADY HAVING DIALYSIS for kidney failure. Thus, there would be minimal added cost to doing this in addition to, or perhaps in place of, filtering the blood for waste. In fact, the more expensive it is now, the more opportunity for savings there would be by doing it a new way. StuRat (talk) 00:24, 18 October 2014 (UTC)

Stu, all I can say is I sincerely hope you and no one you know are so bad off as to need dialysis, and if so, ask your doctor. μηδείς (talk) 03:05, 18 October 2014 (UTC)

LOL. I can't believe you're still arguing this when a reference for LDLapheresis was given above. However, since dialysis, like the kidneys, already does filter out bulk fluid including any small molecular weight wastes, this isn't actually a great leap forward, unless you specifically remove particular problems (like LDL) or unless you know all the mid-molecular-weight substances and can re-extract the ones you want from the waste or provide from an external source and then increase your pore size a bit. (Note dialysis implies a choice of pore size, so your argument amounts to an argument over what pore size to use and how then to compensate for problems of dialysis) But aside from targeted, extraordinary interventions against recognized disease states, it's hard to believe any technology we devise soon can outdo a well-evolved kidney in this department. Wnt (talk) 16:06, 18 October 2014 (UTC)

Kidneys seem to do a good job of filtering waste, but don't do such a good job of filtering out trans fats, saturated fat, bad cholesterol, excess sodium, etc. As for excess sugar, the pancreas gets rid of that by producing insulin, but that results in it being transformed from sugar into fat, which isn't a good thing unless you happen to be at risk of starvation or at least underweight. And most of human evolution took place at a time when the current baddies were in such short supply that removing them from the body wasn't much of a concern. StuRat (talk) 16:21, 18 October 2014 (UTC)

Removing just saturated fat or just trans fat or just cholesterol is not really feasible by any sort of dialysis, since they're in the large LDL particles. The sugar can be eliminated with a kidney tweak (SGLT2 inhibitors dapagliflozin and canagliflozin). I'd have to think more about the sodium. Wnt (talk) 19:38, 18 October 2014 (UTC)

October 18

How is ebola affected by fppp (fossilized phido plankton powder) or by natural chlorine from onions?

12th century Arabic constellation

Hi all.

Can anyone identify the star constellation heading on the left page in this image of the Doha manuscript of the Book of Fixed Stars? A literal translation would do as I can identify the modern constellation from that. It's just that I can't read Arabic script.

I need this information because I would like to nominate the image as a Featured Picture.

Thanks.

Marinka van Dam (talk) 11:40, 18 October 2014 (UTC)

You should ask this question on the Misplaced Pages:Reference desk/Language page - I'm sure they have people who can read Arabic. SteveBaker (talk) 13:28, 18 October 2014 (UTC)

He asked there before he posted here. He's getting some responses there, so I think this one could be closed. ←Baseball Bugs carrots→ 15:15, 18 October 2014 (UTC)

She, actually. Looie496 (talk) 15:33, 18 October 2014 (UTC)

I have no way to know.. Regardless, this could be closed. ←Baseball Bugs carrots→ 15:40, 18 October 2014 (UTC)

Yes, sorry for cross-posting. Wasn't sure which was better. I've had expert response that the left-side page depicts Corona Borealis (The Northern Crown), the right-side page gives the star list for the preceeding constellation Boötes (The Herdsman). Grateful for your time. Marinka van Dam (talk) 17:06, 18 October 2014 (UTC)

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