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| Author |
Message |
| 25 new of 98 responses total. |
russ
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response 50 of 98:
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Nov 30 05:48 UTC 1999 |
(Lots of things in the body, like nerves and muscles, depend on the
ion concentrations of the blood and other fluids being within certain
limits. Too much water thins them out, and stuff starts malfunctioning.
This is bad, because you don't live too long if your nerves quit on you.)
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rcurl
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response 51 of 98:
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Nov 30 06:52 UTC 1999 |
It is nice, though, that the body goes to the trouble of absorbing extra
water and excreting it through a more convenient orifice, rather than just
not absorbing it.
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orinoco
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response 52 of 98:
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Nov 30 18:59 UTC 1999 |
Nice why?
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rcurl
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response 53 of 98:
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Nov 30 19:53 UTC 1999 |
Think.
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orinoco
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response 54 of 98:
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Nov 30 22:51 UTC 1999 |
I don't, remember? It's in my handle. :)
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russ
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response 55 of 98:
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Dec 1 04:17 UTC 1999 |
Maybe if you'd go to the trouble of absorbing and conveniently excreting
your text, you wouldn't have this keyboard diarrhea. ;-)
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keesan
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response 56 of 98:
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Dec 6 15:51 UTC 1999 |
The human digestive system is open at both ends (mouth and anus). If water
went in one end and were not absorbed where would it come out? Orinoco, I
think you would enjoy a first-year biology class even if not required.
(I am afraid I don't get the joke in 55.)
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orinoco
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response 57 of 98:
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Dec 6 16:16 UTC 1999 |
Russ' remark made the situation clear enough, but thanks anyway keesan...
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russ
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response 58 of 98:
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Dec 7 03:32 UTC 1999 |
It was an attempt at humor on response 51.
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oddie
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response 59 of 98:
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Jan 28 04:53 UTC 2000 |
We are doing genetics in biology at the moment, and so I was wondering:
broadly speaking, how is eye color controlled in humans? Is there more
than one gene affecting it, more than one allele, or what?
We are doing sex-linked genes at the moment. Genetics is fascinating.
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keesan
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response 60 of 98:
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Feb 2 02:20 UTC 2000 |
Two genes for brown eyes make brown eyes. Two genes for blue eyes make blue
eyes. One of each gives you hazel/green/light brown eyes. There are probably
several alleles of the brown-eye gene for different amounts of pigment. Don't
know if more than one gene is involved. But two blue eyed parents will not
produce a brown eyed child, though two brown-eyes can produce blue, as the
blue acts recessive.
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oddie
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response 61 of 98:
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Feb 2 04:55 UTC 2000 |
I'm not sure I understand--two "genes" for brown eyes make brown eyes, or
two alleles? In biology class we did one problem where the premise was
that there was one gene for eye color and the brown allele was dominant
over blue, but Mr. Stanley told me that this was a simplified view.
THis hypothesis explains why children of brown-eyed parents can be blue-eyed
(if both parents are heterozygous then both can pass down the recessive
blue allele) but says nothing about other colors.
If there is more than one version of the brown-eyed allele, perhaps there
is one "strong" version, fully dominant over blue-eyes, and a "weak" version
that is codominant with blue eyes?
I could look it up in the big blue tome at school entitled "Mendelian
Inheritance in Man" but I suspect any references there would be a bit too
technical for me...
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tpryan
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response 62 of 98:
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Feb 3 01:47 UTC 2000 |
My two hazel eyed parents had eight hazel eyed kids.
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russ
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response 63 of 98:
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Feb 3 04:44 UTC 2000 |
My two blue-eyed parents had one hazel-eyed kid, and two blue-eyed.
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keesan
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response 64 of 98:
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Feb 4 13:33 UTC 2000 |
I did a search on 'eye color' with AltaVista. From the first source:
Reliable Answers on Eye Color by the MIT Guy 1
By JJ Brannon
[1]jjbrannon@aol.com
_________________________________________________________________
I was a student of Salvador Luria [Nobel Laureate for Genetics] at MIT.
Two brown-eyed parents can easily have a blue eyed child.
Two completely blue-eyed parents CANNOT have a fully brown-eyed child with
normal eye development except in certain extremely rare circumstances.
The gene for brown/blue eyes is EYCL3 found on Chromosome 15.
The gene for green/blue eyes is EYCL1 found on Chromosome 19.
Brown is the result of melanin deposits in the iris.
Green is the result of [this is debated] lipochrome deposits in the iris.
Blue-grey [and in some albinism, pink] is due to a lack of pigment in the iris
.
The underlayer, called the stroma, reflects light through its cells like
a mirror's silver back. How the pigment is distributed over the iris involves
other genes which produce flecks, rays, rings, partial diffusion or
full diffusion. This inheritance is very complicated and the genes have not
been well identified.
Here are some reliable sources:
http://www.ncbi.nlm.nih.gov/htbin-post/Omim/dispmim?227220
http://www.ncbi.nlm.nih.gov/htbin-post/Omim/dispmim?227240
http://www.gdb.org/gdb-bin/genera/genera/hgd/ObjectName/2662023?!sub=0
Francis Galton -- Davenport & Davenport -- Bryn & Winge -- Lenz -- Hughs
as discussed in
Human Genetics, Chapter 5, by Reginald Ruggles Gate [1952]
Heredity & Your Life, pp. 286-312, Boyd [1950]
_________________________________________________________________
References
1. mailto:jjbrannon@aol.com
2. http://sln2.fi.edu/tfi/units/life/forums/anatomy/anatomy.html
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prp
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response 65 of 98:
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Feb 4 20:16 UTC 2000 |
I was reading about the Apple Airport. It said among other things that
the card had a power output of x.x dBm. What is a dBm?
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russ
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response 66 of 98:
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Feb 4 22:54 UTC 2000 |
dBm is decibels relative to a milliwatt. 10 milliwatts = +10 dBm.
One microwatt = -30 dBm. (Decibels are a logarithmic scale, 10 dB
is a factor of ten. One dB is about 1.26.)
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rcurl
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response 67 of 98:
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Feb 5 05:17 UTC 2000 |
i.e., dB = 10*log(P2/P1), where log is base 10 and P2 and P1 are
two *powers* that you want to relate. A useful value to remember is
3 dB = close to a power ratio of 2. Some people try to apply dB to
voltage or current, but then one has to use dB = 20*log (E2/E1).
A related (and commonly used in control theory) terms is the dL -
the decilog, which is simply dL = 10*log(X2/X1) are two similar
quantities whose ratio you want to express over a large range.
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oddie
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response 68 of 98:
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Feb 7 05:10 UTC 2000 |
resp:64
Thank you very much Keesan. I will also have a look at those sources.
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prp
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response 69 of 98:
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Feb 7 19:55 UTC 2000 |
Ah, now if it had been dBmW, I might have had a chance of figuring
it out.
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russ
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response 70 of 98:
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Feb 8 03:50 UTC 2000 |
Every profession has its shorthand. dBm is almost certainly in lots
of glossaries, so if you'd looked you probably would have found it.
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rcurl
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response 71 of 98:
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Feb 8 05:34 UTC 2000 |
I think it is easier to ask in a conference devoted to such things.
Isn't that one of the purposes they serve?
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russ
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response 72 of 98:
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Feb 9 03:03 UTC 2000 |
Never said it wasn't, but learning to RTFM is also important.
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rcurl
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response 73 of 98:
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Feb 9 06:45 UTC 2000 |
That requires having the FM.
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keesan
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response 74 of 98:
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Oct 29 22:22 UTC 2000 |
What happens to oil (alkyd) paint at 30 degrees F, if anything? (Jim left
our primer out last night, sitting on a warmed concrete slab, so it may not
have gone quite to freezing). Why should you not apply it below 45 degrees?
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