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Endocrine Disruption
... vital part, are the pancreas, gonads, kidneys, heart, and parts of the digestive tract. All these different glands or organs work together in the production of certain hormones. Those produced in one location will almost always have an effect on many other areas of the body, not just the surrounding tissues.
An analogy that fits very well with the study of the endocrine system is that of a message in a bottle. We can think of the body as a river, and a specific hormone may be a bottle containing a message. The organs or glands mentioned above would manufacture the “bottles” (hormones) that would be released into the river (blood stream). If there ...
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Black Smokers
... to how life on earth originated. From a distance these stacks may take on the appearance of being just a dull stack of dirt. But if observed closely, one may come to see that these stacks house more than just black material, they are full of life forms. Some of these include giant clams, giant worms, and all sorts of different organisms.
Up until recently, smokers have only been observed by videotape and "deep-diving submersibles". Last summer a team from the University of Washington and the American Museum of Natural History accomplished the task of bringing four "" to the surface. The method that the team used for retrieval was quite interesting. The te ...
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Hurricanes 2
... water vapor in the air condenses. As it condenses it drives the upper drafts to heights of 50,000 to 60,000 feet. The cumuli become towering thunderheads. From outside the storm area, air moves in over the sea surface to replace the air soaring upwards in the thunderheads. The air begins swirling around the storm center, for the same reason that the air swirls around a tornado center. As this air swirls in over the sea surface, it soaks up more and more water vapour. At the storm center, this new supply of water vapor gets pulled into the thunderhead updrafts, releasing still more energy as the water vapor condenses. This makes the updrafts rise faster, pulling in e ...
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The Ozone Layer
... warm. Actually, the man role of the glass in a
green house is to prevent convection currents from mixing cooler air outside
with the warmer air inside.
Although water is the most important factor in the greenhouse effect, is
a major reason why human regions experience less cooling at night than do dry
regions. Changes in both water and carbon dioxide play an important role in
climate changes. For this reason many scientist have expressed concerns over
the global increase of carbon dioxide in resent decades, largely as a result of
the burring of fossil fuels. In many other factors of the earth’s present
climate remain more or less constant, the carbon dioxid ...
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Eugenics
... early societies put into practice. For instance, in ancient Sparta, sickly children were killed or abandoned.1 They filtered out the “undesirable” traits in children, a practice which has come to be called “negative .”2 In the late nineteenth century, a man named Francis Galton gave eugenic thought great emphasis.3 Yet it was not until Gregor Mendel’s theories on genetics were rediscovered by Charles Davenport in 1901 that the ideas of modern was given any credibility.4 Davenport conducted experiments that proved what Mendel had said years before in his laws of genetics. Davenport, however, took it another step. He extended Mendel’s laws to include cha ...
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Protein Synthesis
... transcribed RNA from the nucleus , which is now called messanger RNA [mRNA] as it contains the protein information. This mRNA leaves the nucleus through a nuclear pore, DNA is too large a molecule to do this, to the cytoplasm. In the cytoplasm there are free transfer RNA [tRNA] molecules which hve three protruding bases these sets of three on the tRNA are called anti-codons. Each tRNA molecule attracts different amino acids, of which there are around twenty, and they "stick" to the tRNA and depending on which tRNA molecule it is it wil attract a diferent amino-acid.On the RNA every three bases are called codons these are complementary to the anti-codons of the tRNA. ...
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Black Holes
... that the disk of dust is the remnant of a smaller galaxy that fell into the core of NGC 4261. The black hole will swallow up the gas from the smaller galaxy over the next 100 million years. Researchers believe that while the gas is being swallowed by the black hole, the process will produce some amazing fireworks.
The second puzzling question that astronomers are trying to answer is why isn't the black hole at the center of the galaxy? According to images from the Hubble Space Telescope, the black hole is 20 light-years from the center of the galaxy, but since the black hole is so massive it is hard to explain how it could have been moved. One idea is that t ...
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Male Pattern Baldness
... androgen on the hair follicles that have genetic receptor sites, in other words is resulted by the presence of endocrine hormones (like testosterone) on the hair follicle (which is where the hair is produced) that have genetic receptor sites.
usually is a symmetrical disease, so if there is a non-symmetrical area of baldness, it is not the cause of androgenic alopecia. The typical pattern begins of occur at the hairline, then over time forms an “M”. The crown also begins to become thinner, as does the existing hair. Eventually, the “m” meets the thinned crown and forms the most common bald shape, the horseshoe.
Currently, there a ...
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Radon
... protons but they have different numbers of
neutrons (The America Heritage Dictionary of the English Language, Third
Edition, 1992). The isotopes of a given element have identical chemical
properties but varying physical properties (The America Heritage Dictionary
of the English Language, Third Edition, 1992). A radioisotope is a
radioactive isotope (The America Heritage Dictionary of the English
Language, Third Edition, 1992). A radioisotope is a naturally or
artificially created isotope having an unstable nucleus that decays,
letting off alpha, beta, gamma rays until stability is reached (The America
Heritage Dictionary of the English Language, Third Edition, 1 ...
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The Metric System
... and the light year. Mass has kilograms, milligrams, centigrams, and grams. Density has mass and volume and temperature has Celsius, which is much easier to read than Fahrenheit. Fahrenheit is hard for many people to understand and translate because it is not read in increments of one. Instead it is read having thirty-two degrees Fahrenheit being zero and two hundred and twelve degrees being the boiling point, While the Celsius (metric unit of measure for temperature) is read with one degrees Celsius being the freezing point of water, and one hundred degrees Celsius being the boiling point.
I think that should be used everywhere in the world because it ...
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