Tooth enamel is the most highly mineralized and hardest substance of
the body. Enamel is one of the three major parts of the human tooth,
the others being dentin and cementum. It is the normally visible
dental tissue of a tooth, and must be supported by underlying dentin.
Minerals compose 96% of enamel, with water and organic material
composing the rest. Since enamel is semi-translucent, the color of
dentin and any restorative dental material underneath the enamel
highly affects the outer appearance of the tooth. The color of enamel
is a light yellow to grayish white. It varies in thickness over the
surface of the tooth. Often, enamel is thickest at the cusp, up to 2.5
mm, and the thickness tapers down to a miniscule amount at its border,
which is seen clinically as the cementoenamel junction.
Read the rest of this article:
http://en.wikipedia.org/wiki/Tooth_enamel
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Today's selected anniversaries:
642:
Penda of Mercia defeated and killed Oswald of Northumbria in the
Battle of Maserfield, becoming the most powerful of the Anglo-Saxon
rulers of the time.
(http://en.wikipedia.org/wiki/Penda_of_Mercia)
1100:
Henry I was crowned King of England in Westminster Abbey.
(http://en.wikipedia.org/wiki/Henry_I_of_England)
1858:
Cyrus West Field and colleagues completed the first transatlantic
telegraph cable.
(http://en.wikipedia.org/wiki/transatlantic_telegraph_cable)
1861:
The U.S. government issued its first income tax: 3% of all incomes
over 800 dollars (later rescinded in 1872).
(http://en.wikipedia.org/wiki/income_tax)
1995:
Operation Storm: Croatian forces recovered the town of Knin from the
Republic of Serbian Krajina.
(http://en.wikipedia.org/wiki/Knin)
_____________________
Wikiquote of the day:
"Live as if you were to die tomorrow. Learn as if you were to live
forever." -- Mohandas Gandhi
(http://en.wikiquote.org/wiki/Mohandas_Gandhi)
Marshall, Texas, is a major cultural and educational center in Northeast
Texas, located near the Louisiana and Arkansas borders in the Ark-La-Tex
region. As of the 2000 census, the city had a total population of
23,935. The county seat of Harrison County, the city is known for its
Civil War, railroad, and civil rights movement history, for holding one
of the largest light festivals in the United States, the Wonderland of
Lights, and, as the self-proclaimed Pottery Capital of the World, for
its sizable pottery industry. It is also known variously as the
Cultural Capital of East Texas, the Gateway of Texas, the Athens of
Texas, and the City of Seven Flags. Read the rest of this article:
http://en.wikipedia.org/wiki/Marshall%2C_Texas
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Today's selected anniversaries:
435:
Nestorius, the originator of Nestorianism, was exiled by Byzantine
Emperor Theodosius II to a monastery in Egypt.
(http://en.wikipedia.org/wiki/Nestorius)
1916:
Sir Roger Casement was hanged for his role in the Easter Rising in
Ireland. (http://en.wikipedia.org/wiki/Roger_Casement)
1923:
Calvin Coolidge was inaugurated as the 30th President of the United
States, succeeding Warren G. Harding.
(http://en.wikipedia.org/wiki/Calvin_Coolidge)
1940:
World War II: Approximately 175,000 Italian troops invaded British
Somaliland, beginning the East African Campaign.
(http://en.wikipedia.org/wiki/East_African_Campaign)
1948:
Whittaker Chambers accused Alger Hiss of being a communist and a Soviet
spy. (http://en.wikipedia.org/wiki/Whittaker_Chambers)
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Wikiquote of the day:
"When I talk of the purpose of life, I am thinking not only of human
life, but of all life on Earth and of the life which must exist upon
other planets throughout the universe. It is only of life on Earth,
however, that one can speak with any certainty. It seems to me that all
life on Earth, the sum total of life upon the Earth, has purpose." --
Clifford D. Simak (http://en.wikiquote.org/wiki/Clifford_D._Simak)
The Common Unix Printing System is a modularised computer printing
system for Unix-like operating systems that allows computers to act as
powerful print servers. A computer running CUPS is a host which can
accept print jobs from client computers, process them, and send them
to the appropriate printer. CUPS consists of a Unix print spooler and
scheduler, a filter system that convert the print data to a format
that the printer will understand, and a backend system that sends this
data to the print device. CUPS uses the Internet Printing Protocol as
the basis for managing print jobs and queues. It also provides the
traditional System V and Berkeley command line interfaces, along with
limited support for the server message block protocol. The device
drivers CUPS supplies are based on the PostScript Printer Description.
There are a number of user interfaces for different platforms that can
configure CUPS, and it has an inbuilt web-based interface.
Read the rest of this article:
http://en.wikipedia.org/wiki/Common_Unix_Printing_System
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Today's selected anniversaries:
1870:
Tower Subway, the world's first underground railway, opened in London.
(http://en.wikipedia.org/wiki/Tower_Subway)
1903:
The Internal Macedonian Revolutionary Organization and Bulgarians in
the Ottoman Empire carried out the Ilinden Uprising.
(http://en.wikipedia.org/wiki/Ilinden-Preobrazhenie_Uprising)
1934:
Adolf Hitler became Führer of Nazi Germany.
(http://en.wikipedia.org/wiki/F%C3%BChrer)
1990:
Iraq invaded Kuwait, triggering the Gulf War.
(http://en.wikipedia.org/wiki/Gulf_War)
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Wikiquote of the day:
"When are you people going to learn? It's not about who's right or
wrong. No denomination's nailed it yet, and they never will because
they're all too self-righteous to realize that it doesn't matter what
you have faith in, just that you have faith. Your hearts are in the
right place, but your brains need to wake up. I have issues with
anyone who treats faith as a burden instead of a blessing. You people
don't celebrate your faith; you mourn it." -- "Serendipity" in Dogma,
by Kevin Smith
(http://en.wikiquote.org/wiki/Dogma)
Henry Moore was an artist and sculptor. Born into a poor mining family
in Castleford, he became well known for his large scale abstract cast
bronze and carved marble sculptures; substantially supported by the
British art establishment, Moore helped to introduce a particular
strand of modernism into Britain. His ability to satisfy large-scale
commissions, led him to become exceptionally wealthy towards the end
of his life, although he spent little and the bulk of his wealth went
to endow the Henry Moore Foundation which continues to support
education and promotion of the arts. His signature form is a pierced
reclining figure, first influenced by a Toltec-Maya sculpture known as
"Chac Mool," which he had seen as a plaster cast in Paris in 1925.
Early versions are pierced conventionally as a bent arm reconnects
with the body; later more abstract versions are pieced directly
through the body, in order to explore the concave and convex shapes.
These more extreme piercings developed in parallel with Barbara
Hepworth's sculptures, when she first pierced a torso after misreading
a review of one of Henry Moore's early shows.
Read the rest of this article:
http://en.wikipedia.org/wiki/Henry_Moore
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Today's selected anniversaries:
1774:
Joseph Priestley discovered oxygen, corroborating the prior discovery
of this chemical element by Carl Wilhelm Scheele.
(http://en.wikipedia.org/wiki/oxygen)
1798:
French Revolutionary Wars: The Battle of the Nile started between
French and British fleets.
(http://en.wikipedia.org/wiki/Battle_of_the_Nile)
1927:
People's Liberation Army was established in China.
(http://en.wikipedia.org/wiki/People%27s_Liberation_Army)
1944:
The Warsaw Uprising against Nazi occupation began in Poland.
(http://en.wikipedia.org/wiki/Warsaw_Uprising)
1981:
MTV debuted with the song Video Killed the Radio Star by The Buggles.
(http://en.wikipedia.org/wiki/MTV)
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Wikiquote of the day:
"From without, no wonderful effect is wrought within ourselves, unless
some interior, responding wonder meets it. That the starry vault shall
surcharge the heart with all rapturous marvelings, is only because we
ourselves are greater miracles, and superber trophies than all the
stars in universal space." -- Herman Melville
(http://en.wikiquote.org/wiki/Herman_Melville)