Wikipedia:Reference desk/Archives/Science/2016 March 27

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March 27

What is the meaning of AKA in the context of the nervous system anatomy?

What is the meaning of the letters AKA in the context of the nervous system anatomy or physiology? (except of "also known as"). 93.126.95.68 (talk) 00:42, 27 March 2016 (UTC)

AKA is Alcoholic ketoacidosis in the field of endocrinology, fwiw. Do you have any more context, or a pointer to an example?--Tagishsimon (talk) 00:50, 27 March 2016 (UTC)

To be honest I just heard my teacher say it when he gave us an introduction on the nervous system. He explained something about it but I unfortunately I forgot it. and I don't find where I wrote it, if any. I sent message to my teacher in a request to remind me it. Thank you93.126.95.68 (talk) 01:22, 27 March 2016 (UTC)

He may have just meant the basic aka - also known as -. Graeme Bartlett (talk) 10:36, 27 March 2016 (UTC)

This seems the most likely explanation to me; ketoacidosis could come up under the context of the monstrous amounts of glucose consumed by the brain, but it seems like an odd association to draw in an introductory discussion of the nervous system. If there's another neurophysiological usage for AKA, I'm drawing a blank on it, so it seems likely from the context that the OP describes that it was marking a synonymous relationship between two structures, processes, or concepts. Snow ^{let's rap} 08:03, 1 April 2016 (UTC)

What does it mean "specialized population of neurons"?

What does it mean "specialized population of neurons"? the full context is (from the Campbell textbook): "In all but the simplest animals, specialized populations of neurons handle each stage of information processing. • Sensory neurons, like those in the snail’s siphon, transmit information about external stimuli such as light, touch, or smell, or internal conditions such as blood pressure or muscle tension. • Neurons in the brain or ganglia integrate (analyze and interpret) the sensory input, taking into account the immediate context and the animal’s experience. The vast majority of neurons in the brain are interneurons, which form the local circuits connecting neurons in the brain. • Neurons that extend out of the processing centers trigger output in the form of muscle or gland activity. For example, motor neurons transmit signals to muscle cells, causing them to contract." By the way, Does it say that each acting occurs due to these three stages? If it does, I wonder because when we think about something and then decide to act (e.g. to take something from the table) actually we pass just two stages, because we don't really use sensory neurons for the information processing.93.126.95.68 (talk) 01:42, 27 March 2016 (UTC)

In this context "population" just means "a distinct group of". Action does arguably involve the three groups mentioned. In your example of taking something from the table, the sensory inputs you ignore might well be sight (you have to see the table and the object, and if you're blind, then touch), but also proprioception - where is your hand, your arm, etc; how well are they responding to actions initiated in support of your objective? --Tagishsimon (talk) 01:47, 27 March 2016 (UTC)

thank you for your comment, it helped me. I didn't ignore of the sight, because I meant to case that you don't saw it at the same moment. for instance, if you are reading a book and suddenly you feel that you're hungry then you decide to go the kitchen and to open the refrigerator. Does it says that you saw it before? and why does the text limit it to a distinct group of neurons? do exist other types of neurons which don't pass these three stages? 93.126.95.68 (talk) 01:55, 27 March 2016 (UTC)

In this instance they are probably referring to neurons with different specialized morphology. See retina - two of the figures show the different layers and different types of connectivity in each layer, though I've seen far far better illustrations. However, I think that the statement as written could refer to something else, which is when you have an initially homogeneous set of neurons with the same apparent cellular identity and different ones are recruited to different tasks - like which ones react to a particular word or touch to a particular spot on the body. In that case the connectivity is also different, of course, but the differences may be much more subtle, not morphologically recognizable. Wnt (talk) 02:05, 27 March 2016 (UTC)

Reading through Nervous tissue may assist you. That article shows a number of different ways of grouping nerve tissue. The list you gave, above, is a functional classification - which must be seen for what it is - a very broad and very simple means of introducing and describing subdivisions of the nervous system. I'm not sure it is very useful to spend time looking for actions which can be performed using only two of the three in the classification system. And, clearly, it is possible to break down the functional classification further, into sub-classifictions. Or to reach for one of the other classifications mentioned in the Nervous tissue article. --Tagishsimon (talk) 02:28, 27 March 2016 (UTC)

Military applications of wafersats

I was surprised to read a claim [1] that it is possible to send instrument probes to Alpha Centauri and other stars within 10 light years using a laser light sail approach. One thing that they don't seem to discuss at all: the lack of spread of the beam. It isn't that clear to me how long the probe accelerates for before the beam spreads out too much to be caught by the sail, but they seem to describe sails just meters across being beamed at for some appreciable portion of a light year.

If this is true, then these probes seem like the basis of some rather devastating space weapons. For example, the probes - tiny things, grams in weight, probably cubesat material - might be deployed in low Earth orbit, using more rigid reflectors than described. A laser of the type used for probe propulsion can then be bounced off them to set fire to thousands of widely separated remote wilderness sites in a short span of time, or burn right into a giant tank of natural gas (I mean, they talk about a reflector capable of withstanding 10⁵ suns of brightness!), or I suppose to lock onto some VIP caught out in the open. This isn't the first time I've seen hints of such capabilities (the AF 2020 report was another), but I've also seen claims that you can't collimate a laser beam well enough to pull it off. So .... can you? What is the feasibility here, for either application? Wnt (talk) 02:22, 27 March 2016 (UTC)

Military Industry has been trying to make this work since befor 1984. See Strategic Defense Initiative. Over the years every now and then someone claims to finaly have a working experimental model, presents something alike, but then every time you never read about it again. --Kharon (talk) 11:26, 27 March 2016 (UTC)

There is a huge difference in range due to air. Air contains dust and perhaps water droplets, both of which spread the beam out and/or absorb it. Space also contains dust, but at a much, much lower density (can somebody put some numbers on this ?). Also, temperature differences in layers of air can defract the beam. This is why stars sometimes appear to "twinkle". StuRat (talk) 13:51, 27 March 2016 (UTC)

Transparent enough that you can see Deneb right in the middle of the Milky Way through several thousand light years of the galactic disc. 10 light years would be like a 300th root of the Earth to Deneb light transmission percent would it not? Unless the 10 light years are dustier than average but it would still be very very transparent. Sagittarian Milky Way (talk) 16:01, 27 March 2016 (UTC)

And the Hubble telescope can see objects tens of billions of light years away, which is way past the end of the block ! StuRat (talk) 15:03, 31 March 2016 (UTC)

Nephron can be considered also as a cell?

I know that the nephron is renal functional unit but I'm asking if we can consider it as a cell? 93.126.95.68 (talk) 03:31, 27 March 2016 (UTC)

No, a nephron is an assembly of many hundreds or thousands of cells. This page briefly describes the cells found in a nephron. Someguy1221 (talk) 07:55, 27 March 2016 (UTC)

A simple kidney in small bilaterians consists of a flame cell and tube cell. I think that the collecting aspect of a nephron would hint that the tube cell should be counted as part of its equivalent there, but you could argue the issue. Another question is whether it can be counted as a nephron when there is no loop of Henle (AFAIK). A weirder variant is the nephrocyte - honestly I have no idea what it's doing in the esophagus ( see [2]) but it is said to be homologous to a podocyte. Wnt (talk) 10:33, 27 March 2016 (UTC)

Effective Strength of a martian "Storm"

Storms on earth can cause many effects - even blow away houses and more. This needs force measured in pressure per square inch. On Mars The resulting mean surface pressure is only 0.6% of that of Earth - so I'd like to know, how much force a martian storm of perhaps 400 km/h can provide at one suare inch (or cm²) to press against objects (and perhaps to move them) - in other words: can such a storm do more that letting a flag flutter? Chiron McAnndra (talk) 14:05, 27 March 2016 (UTC)

There is a movie showing the Telltale of the Phoenix mars lander moving. I try to find how heavy the thing is but look at the movie first [3] --Stone (talk) 14:31, 27 March 2016 (UTC)

The small tube with the fibres is in the 10mg range and the length is 2-3 cm. [4] This looks like even on a windy day on Mars you would require a real low weight flag, or do the same cheating like on the moon. --Stone (talk) 14:38, 27 March 2016 (UTC)

If 400 kph is correct it should be like a 400kph*0.6%**.5 wind on Earth times some adjustment for density (~44 amu vs 29 average particle mass and it's colder so denser) and the force of the wind-driven dust particles. That seems plenty to fly a flag. I don't know how fast the dust moves or how thick it is. When there is no dust storm (which is often) the wind isn't strong enough to pick up any dust by definition so it is pretty weak. Sagittarian Milky Way (talk) 15:47, 27 March 2016 (UTC)

(ec)Assuming mostly turbulent flow, drag grows quadratically with velocity, but linearly with density. So a 400 km/h storm at 0.6% surface pressure should create roughly the same force as a wind of 30km/h on Earth - that is a "fresh breeze" (Beaufort scale 5 on Earth. Not catastrophic, but certainly noticeable. As a beginner, you don't want to experience that in a Hobie Cat. As a good sailor, its probably where the fun begins ;-). All modulo misunderstanding of the physics and errors in the math.... --Stephan Schulz (talk) 15:52, 27 March 2016 (UTC)

(ec) Worth noting is that the wind speed in Martian storms is usually vastly overstated. Measured wind speeds on the Red Planet top out around 30 m/s (in round numbers, 60 mph or 100 km/h)— quite a strong wind on Earth, but not extraordinarily so. (Here on Earth, sustained 30 m/s winds would be a tropical storm, not even qualifying as a lowest-grade hurricane.) Note also that wind forces scale with the square of velocity, so cutting the wind speed by three-quarters reduces the force by a factor of 16. TenOfAllTrades(talk) 15:54, 27 March 2016 (UTC)

Our article on Dynamic pressure can help you get a rough approximation. So at 400km/h or 111m/s and [5] give an air density on Mars of about 0.020 kg/m3. Thus, that gives one q=0.5(0.02)(111)2 = Pa
From there you can get your kg ⋅ m/s2 . So, yes it would feel very windy.--Aspro (talk) 15:56, 27 March 2016 (UTC)

Such storms would have a much lower impact than what was depicted in The Martian (film). It would also not carry rocks, but only a thin sand that would feel more like smoke. For more details: storms in Mars.--Scicurious (talk) 19:10, 27 March 2016 (UTC)

Is solder for mechanical joining different from electrical?

Is there a difference in the chemical composition of solder intended for electronics vs mechanical joining of e.g. pipes or other large pieces of metal or are they just different in diameter of wire/pieces? --78.148.107.251 (talk) 16:38, 27 March 2016 (UTC)

There are different kinds of solder. Please see the Solder article - especially the Solder alloys table. MarnetteD|Talk 16:46, 27 March 2016 (UTC)

Oh boy! I just want to repair a broken candelabra which I think is bronze plated carbon steel. --78.148.107.251 (talk) 20:33, 27 March 2016 (UTC)

To solder steel you need to use a silver solder (either silver and lead, or silver and cadmium) and will need a powerful soldering iron as the heat required is much greater than when using tin based solder for electronics. 109.150.174.93 (talk) 13:57, 28 March 2016 (UTC)

Brazing or welding are more likely to be used on large pipes or pieces of metal. StuRat (talk) 16:50, 27 March 2016 (UTC)

They have to be different. Solder in electronic components has to conduct electricity. There are further subdivisions by type of alloy or being leadfree (or not) — Preceding unsigned comment added by Scicurious (talk • contribs) 19:01, 27 March 2016 (UTC)

The flux used differs also. For electrical work, you will want one that does not need washing off, and will not corrode the surfaces. Graeme Bartlett (talk) 21:29, 27 March 2016 (UTC)

Deep space telescope

This article mentions a "solar lens focus where the Sun acts as a gravitational lens to magnify distant objects". Einstein predicted a 542 AU focal length but it seems difficult to obtain an image through a "lens" whose deflection angle of light decreases away from the axis, and whose center is blinding. Is it sensible to send a radio- or optical Hubble-like telescope all the way out there to take a look? AllBestFaith (talk) 18:53, 27 March 2016 (UTC)

At least it still magnifies. You should block out the Sun with something like a coronagraph. Thousand Astronomical Units mission gives some idea of what this kind of mission would be like. Sagittarian Milky Way (talk) 20:14, 27 March 2016 (UTC)

Cats

If cats are solitary creatures, why do they make good pets in large human households? Surely, if there were solitary they wouldn't allow themselves to be domesticated, show affection to people, etc. I'm not sure the argument that we give them convenience flies that well, because they're perfectly able to fend for themselves. Also, in countries where there are large stray cat populations, like Egypt or Turkey, they seem to work together. Is the solitary and aloof quality associated with cats just a myth, are they closet pack animals? --Andrew 19:30, 27 March 2016 (UTC)

I don't know what you mean by "solitary creatures." They are more independent than dogs, and also have a shorter domestication history behind. But that does not conflicts with the fact that they simply evolved to be around humans. Just because they could live independently out in the wild does not mean that getting food from an old lady is not their first preference. The question is why humans keep them, since they do not provide any service nowadays. Maybe being small non-threatening furry and cute helps their case. At the beginning it might be that they were convenient back then, since they could catch mice, and mice were near us since we are good at producing grain. --Scicurious (talk) 19:38, 27 March 2016 (UTC)

Wild cats are solitary. Domesticated cats (including ferals) are not. http://icatcare.org/advice/understanding-your-cat/social-structure-cat-life Iapetus (talk) 20:16, 27 March 2016 (UTC)

The answer is actually quite simple. It depends on food availability. If food is plentiful, domestic cats will readily tolerate each other, even in large groups. Hence the scenes of many feral cats coming together when they are being fed by well-meaning humans, or individuals owning 20+ cats in their homes. Cats can be highly dangerous in aggressive interactions so it is to their benefit to avoid confrontation and aggression. If they have plenty of food, there is no benefit in fighting. Generally, cats, including domestic cats, are considered to be solitary - I think the only exception is lions, although cheetahs will form sibling alliances.DrChrissy ^(talk) 20:27, 27 March 2016 (UTC)

I would question the "they do not provide any service nowadays" assertion above. A cat provides companionship with less upkeep needed than even a small dog requires, and they eliminate small vermin from residences. --Guy Macon (talk) 22:02, 27 March 2016 (UTC)

Mine bring the bloody things in! "Hey Dad - look what I brought you!" ;-) DrChrissy ^(talk) 22:08, 27 March 2016 (UTC)

Are you trying to say that they provide affection in exchange of food? That looks much more like a private association than a service that it's being provided. I'd like to see a cat plowing a field. Scicurious (talk) 23:04, 27 March 2016 (UTC)

I don't know if there are any clear boundaries and I don't think human boundaries are necessarily applicable to humans. For example an escort, even in a case where they're mostly providing companionship or affection rather than sex will probably be said to be providing a service. This is a lot less common with a kept man or woman (let alone a spouse). If you hire someone to plow your field and they aren't your employee (or to some extent if they are) you may say they are providing a service, if your son or daughter or spouse helps you this is far less common.

But as said, I don't know if these boundaries are that useful.

BTW this all seems to be besides the point, since the issue of concern was whether "question is why humans keep them, since they do not provide any service nowadays" is meaningful. If you now recognise you should not have said only service but should have said ".... do not provide any service or private association nowadays" then we can discuss that instead. If you decide instead that these can be called service, it's the same thing. The statement "question is why humans keep them, since they do not provide any service nowadays even though they do provide a private association in the form of affection or companionship" doesn't make much sense.

Nil Einne (talk) 00:02, 28 March 2016 (UTC)

From a human perspective, maybe the line is to be drawn between what you like and what you need. You like the cat's affection, but you need them to catch mice, in the same way that you need the protection a dog can provide against other animals. The question is why do we like cats, and why we are affectionate towards non-humans, although we could quite well survive without them. --Scicurious (talk) 00:06, 28 March 2016 (UTC)

There are many things we don't definitely need including often the services or private affection/companionship of other humans, so part of your question doesn't make much sense. Also your boundaries are flawed mostly because boundaries are nearly always fussy. If you live in a fairly urban environment, having a cat to catch the odd mouse may be slightly useful, but actually it's often far less useful than the companionship. Particularly for someone who lacks sufficient human companionship for whatever reason. (And human companionship isn't automatically superior than non human animal depending on many factors.) To put it differently, the companionship/affect may very well have a far bigger effect on your lifespan or wellbeing than the mouse catching bit. If you live in a farm, it may be something very useful to have, but depending on the specific circumstance may not be essential. I.E. It's not guaranteed you're not going to survive without it. Nil Einne (talk) 00:54, 28 March 2016 (UTC)

Almost all wild cats are solitary. Only Lions typically live in groups. However most other cats are known to build bonds with others sometimes despite usually being solitary. All domesticated animals are breed races pretty much like domesticated plants. The feral and solitary instinct in cats was breed out or genetically sorted out over many generations. Looking at domesticated plants you can see the huge changes breeding has achieved since it became a profession in the earliest civilisations. So in comparrison its not such a big wonder when housecats today are so very different from wild cats nomatter they are biologically still close enough to proliferate.

What makes cats "good" pets is clearly their exessive grace and majestic nature. We humans simply love them for that. Almost any palace in the world has some stone cats as guard nomatter no civilisation ever used "guardcats". Palaces should have stone dogs but who wants that if he can have majestic stone cats? So are they really our pets or are we theirs? --Kharon (talk) 00:29, 28 March 2016 (UTC)

Scicurious says "I'd like to see a cat plowing a field." Here you go:

• https://www.youtube.com/watch?v=H2HuoyvDp7c
• https://www.youtube.com/watch?v=7iA2Z-QlHUQ

--Guy Macon (talk) 00:45, 28 March 2016 (UTC)

I would point out that I don't think comparing to random other species of Felidae is necessarily useful anyway. If all cats except all of the closest descendants of the house cat, were solitary; but all of the closest descendants live in groups (and perhaps we even have reason to think the most recent common ancestor lived in groups), the all cats bit is likely to be mostly irrelevant. On the other hand, if all cats except all of the closest descendants of the house cat, live in groups; but all of the closests descendants live solitary (and perhaps we even have reason to think the most recent common ancestor was solitary), the all cats bit is also normally going to be largely irrelevant. (Undomesticated wild cats which are in some ways the same species are solitary, which is what you should be mostly looking at although as said, with domesticated animals you have to take great care considering how quick certain changes can happen. There may be some limited utility of considering whether the solitary bit is related to specific evolutionary adaptions which haven't significantly changed even in the group ones including related to whatever possibly related niche they fill. As well as whether adapting to solitary existance or group may be slightly easier in evolutionary terms. But ultimately looking at the other relatives is only likely to be slightly useful.) Nil Einne (talk) 01:09, 28 March 2016 (UTC)

1) When we say cats are naturally solitary, we mean except for the mother cat raising the kittens until they can fend for themselves. There are some animals that don't do this, and those are truly solitary.

2) Domestic cats have been (intentionally or unintentionally) bred for the characteristics we like. The result of this process is that we bred them for neoteny, which means the adults still behave much like kittens. That is, they play and treat their owners (even men) as if they are the mom cat, going to them for food and grooming. Note that this is different from dogs, which treat their owners as the pack leader. You can challenge a pack leader and try to become the new pack leader, but you can't challenge "mom" and try to become the new mom.

3) As far as what service cats provide, they seem to lower our stress levels and blood pressure, with all the health benefits those bring. I imagine medication to do the same would cost quite a bit, and have serious side effects. StuRat (talk) 02:31, 28 March 2016 (UTC)

Two points: 1) The very "neoteny" to which StuRat refers, and which we have selectively bred into our domestic cats which we keep as pets (we want them to be kittens for life), may have a "side effect" of making them more accommodating towards each other, just like kittens of the same litter rarely get into serious brawls (playfighting is a different story).

2)The OP may find our article on the evolutionary processes of Self-domestication to be of interest. At some point, cosying up to a human, who in turn provides you with food and shelter in return for some affection, makes evolutionary sense, and the cats which do this will outlive those which don't, or form their own distinct self-sustaining population. I daresay cats are not committed solitary creatures. They can cope with solitude, but if manipulating a human with a show of affection will get them food, they're more than happy to oblige. Even (some) strays are known to attempt to "befriend" humans, so the self-domestication trait remains. Cats seem to have developed a masterful sense of how to manipulate us humans, and most cat owners will happily admit this fact. Eliyohub (talk) 14:11, 28 March 2016 (UTC)

I don't agree with the idea that they manipulate people, if you mean they don't really like us but just pretend that they do. For one, deception like this requires more intelligence than they have, specifically it requires the theory of mind. That is, they would need to know what you are thinking and how their behavior would affect your thoughts. I believe they genuinely like being petted, as it removes loose fur they might otherwise swallow, provides warmth, etc. Again, they don't think all this through, but cats that enjoyed being petted were more likely to survive to pass on this gene to others. StuRat (talk) 16:17, 28 March 2016 (UTC)

Yes, I agree. Many of these behaviours are simply Associative learning. Cats mark their territory with glands on their cheeks, around their mouths and at the base of their tails. Somewhere along the line, humans liked being "marked" (rubbed) by cats and rewarded this with food. Humans would then have artificially selected cats, or otherwise increased their biological fitness by e.g. targeted feeding, which have a greater propensity for rubbing against humans. This relationship is completely due to the humans mistaking cat's natural marking behaviour as an indication of affection. Similarly, the kneading behaviour which many cats show: they have scent glands in their paws. The ability of humans to change cat behaviour can be great. Most cats meoww to us, especially for food. But cats do not meow at each other. This appears to be a behaviour which is directed uniquely to humans. Again, it can be explained as associative learning, perhaps followed by artificial selection. DrChrissy ^(talk) 16:38, 28 March 2016 (UTC)

• You can take this as OR if you like but it is very evident from observation. Man may have domesticated the dog but cats domesticated themselves symbiotically. When Man started to form semi-permanent settlements it was because they stored food of a nature that attracted rodents. The higher rodent population attracted cats to the area. Out of every littler of cats, one proves more bold and adventurous than the rest and one proves more docile. Neither attribute is good for survival in the wild. Yet, during the times when the cats natural pray is scarce and starvation threatens, those cats that have modified their behaviours (the various traits combining to be compatible to how human live)., and not to snare and claw at any human (and more importantly -any human child) will be better tolerated and feed by the village community, because the community appreciated that the cats eat rodents, which in turn, ate the villages food supplies. When, the cats natural food supply becomes more plentiful, they go back hunting for that. Cats prefer a freshly caught rodent above what humans can feed them. Cats are lone hunters but in a village, they congregate for protection against bigger critters. One only has to see how a domestic cat reacts to the presence of a nearby fox. Its strength in numbers. Also they don't have to be biologically related to the litters that they watch over – because if they come to have a litter, the same protection will be afforded to theirs. Lets go back to food. A human settlement provides an opportunity to occasionally get a rat. That takes some three days to fully digest and so they don't need to sit with the other cats nor hunt again during that time. Somewhere quiet for digestion may be afforded in a humans hut, in a spot that is away from drafts from the entrance and somewhere warm at night (a full belly switches off the need of nocturnal behaviour). Repeated visits to a particular home and comfortable place may make the cat want to make this resting space its own. i.e. if it returns to find a human sitting their already. It never the less tries (and often succeeds) to occupy the same space. Just like ones own moggie. I has is favourite chair before the fire and if after its meal it finds a human sitting their already, it will leap upon their lap, because that-is-their-preferred-resting-place. Survival fitness (in this particular ecological niche) means that after several generations, cats that can do this (from their own selective breeding) and tolerate the house family’s little Jane or John Doe from stroking him/her and muttering “Hallow little pussy” much like the kittens in the commune group do, affording them a much better chance of survival in the long term, than their cousins in the wild. So, the trait of self domestication perpetuates itself. --Aspro (talk) 14:13, 28 March 2016 (UTC)

• While I agree that most of cat breeding was accidental, there was also some intentional breeding, such as the Sphynx cat. StuRat (talk) 16:25, 28 March 2016 (UTC)

We may have domesticated and keep cats for other reasons which are not immediately obvious. One hypothesis about why cats purr is that this heals their bones (see the Purr article. It is possible that purring is a low energy mechanism that stimulates muscles and bones. The frequency of their purr is also consistent with bone healing in humans. Perhaps we domesticated cats partly for this. The other word which seems to be missing in our discussions above is "entertainment". Perhaps editors have been using the word "affection" in a way which includes entertainment, but the two can be separate; keeping a goldfish is entertainment (providing a service), but I struggle to think of them as providing affection. DrChrissy ^(talk) 14:32, 28 March 2016 (UTC)

Kittens are often separate from their mother as soon as they have been weaned. But they have still not developed independence. So of-cause they look at their new providers of food and shelter thus showing affection. - its instinctive (Imprinting (psychology) and all that). Also, why separate entertainment. A new born into the family provides a lot of entertainment (in between diaper changes) because it is part of the bonding system we form with others around us -that is hardwired into our genes. As for keeping cats for other reasons which are not immediately obvious. My cat often walks across my computer key board and corrects my coding errors but I put that down to rare chance occurrences. She is more than probably, trying to remind me that she wants her nice bit of Coley that she has trained me to buy for her – by showing me great affection when she gets a whiff of it in the shopping basket (cats are not very good at sailing fishing boats or visiting the supermarket). Cats may have physical small brains but they are wired up in such away that they can fool us into thinking that we only possess the power of will and control over our actions. Oh, got to brake off here as she's now meowing at me because I've forgotten to add a few drops of vanilla essence to her dish of milk (and it has to be full cream not semi-skimmed). It was cats that domesticated man, so that we could provided them with a continuous supply of food shelter and warmth; not the other way around --Aspro (talk) 21:23, 28 March 2016 (UTC)

"of-cause" = "of course" ? StuRat (talk) 21:41, 28 March 2016 (UTC)

Well of course, watt did u think I ment? :¬) --Aspro (talk) 21:47, 28 March 2016 (UTC)

Less intelligent animals and even plants are able to fool us into thinking they are smarter than they are, by evolving instincts (in the case of animals) which accomplish the same things we need to use our intelligence to accomplish. For example, if a plant loses one water source, it has a way of growing it's roots towards another. In humans, finding a new water source requires intelligence, with one notable exception. StuRat (talk) 22:15, 28 March 2016 (UTC)

@Aspro - the feeding of milk to cats is purely because humans have learned that cats like it and get a sense of "being kind" by giving it to them. In nature, adult cats do not drink milk. Animals, including humans, do not always consume food or drink that is necessarily good for them. I strongly suggest you stop feeding your cat milk - it can be harmful. Water is perfectly fine. DrChrissy ^(talk) 23:22, 28 March 2016 (UTC)

Water? Try convincing my moggy of that. On second thoughts don't – she may may hide the key to my store of single malt whiskey until I repent. Cats are natural Carnivore#Obligate_carnivores and will turn up their noses at anything unhealthy – unless they live in the city and have no choice but eating supermarket 'cat food,' which is a euphonium for cheap and nasty. Which in turn leads to high vet bills when they eventually ail from being offered only a poor diet. Not all cats are lactose intolerant – she may be intolerant to my young nephew swing her round by the tail -but not milk. Let them choose their own food and they will reciprocate by correcting ones coding errors, retexture one's upholstery with their claws and purr away, oblivious to any sneezes around them due cat dander allergy. Which face it. Is a human immune problem anyway and not the cats fault at all. If this allergy of ours did bother cats, they would have selective bred this malady out of their slaves long ago.--Aspro (talk) 00:29, 29 March 2016 (UTC)

"euphonium" = "euthemism" ? AllBestFaith (talk) 14:04, 29 March 2016 (UTC)

Unless the cat plays the euphonium, I suspect he meant euphemism. StuRat (talk) 15:07, 29 March 2016 (UTC)

Cue more hilarious videos from @User Guy Macon: I hope ;-) DrChrissy ^(talk) 15:17, 29 March 2016 (UTC)

See wikt:euphonious - the definition fits for that. Personally, I reserve an absolute right to make up English words I want as I go along, but not being a native speaker of Greek I'm more hesitant with that ... but I think most people are the reverse, so I'll say fair ball. Wnt (talk) 23:11, 29 March 2016 (UTC)

Lactose tolerance in adult cats

The above discussion makes me wonder if a large portion of cats, like humans, have developed tolerance for lactose as adults. Since cats have been living with humans who herd domesticated animals, some have probably been given milk, or poached some which was left out. Those who could tolerate it were more likely to survive and pass on this gene. And there may have been more cat generations since they were domesticated than human generations since herding began, therefore it seems quite possible some may have developed lactose tolerance, at least in areas where milk was available. So, do we have a situation mirroring lactose toleration in humans, where some populations are largely exhibit lactose intolerance, and others don't ? StuRat (talk) 01:18, 29 March 2016 (UTC)

Adult cats are normally lactose-intolerant[6]. The undigested lactose passes through the intestinal tract, drawing water with it. Bacteria in the colon also ferment the undigested sugars, producing volatile fatty acids. This may induce vomiting and the most common symptom of lactose intolerance in cats is diarrhea. And there is an old Russian saying: The cat with cream on his whiskers had better find good excuses. - Ninotschka (Greta Grabo, 1939). AllBestFaith (talk) 15:04, 29 March 2016 (UTC)

What does "non-Gaussian AO situations" mean?

Within the context of statistics and control theory I found this sentence:

"produces estimates that are quite good approximations to the exact conditional mean in non-Gaussian AO situations"

What does "AO" mean? source Ferrofield (talk) 22:10, 27 March 2016 (UTC)

Or another source, Masreliez’s theorem. Appears to mean "additive outlier". Which tells me nothing except that I can look stuff up. --jpgordon^{::==( o )} 22:32, 27 March 2016 (UTC)

Maybe Adaptive Optics [7] Loraof (talk) 00:02, 28 March 2016 (UTC)

I found the answer on page 1046 of the link provided by the OP: A section is entitled "IO+AO", and the first sentence contains the phrase "innovations and additive outliers". Loraof (talk) 00:14, 28 March 2016 (UTC)