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» Browse Science and Environment Term Papers
Evolution Of Immunity And The Invertebrates
Number of Words: 1152 / Number of Pages: 5
... distinguish between
one's own cells and "non-self" cells. The second job is to eliminate the non-
self cells. When a foreign object enters the body, several things happen. Blood
stops flowing, the immunity system begins to eliminate unwanted microbes with
phagocytic white blood cells. This defensive mechanism is possessed by all
animals with an innate system of immunity. Innate cellular immunity is believed
to be the earliest form of immunity. Another form of innate immunity is
complement, composed of 30 different proteins of the blood.
If these mechanisms do not work to defeat an invader, vertebrate ...
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Irrigating Crops With Seawater
Number of Words: 849 / Number of Pages: 4
... halophytes and began testing these plants in the desert of Puerto Peņasco. They irrigated the plants daily by flooding the fields with seawater from the Gulf of California. The best halophytes produced roughly the yield of alfalfa using freshwater irrigation. In order to show that these halophytes could replace other crops for use they tested to see if the crops could feed livestock. The halophytes have protein and carbohydrates but they contain too much salt. This limits the amount an animal can eat and dilutes the nutritional value. Therefore, the authors decided to use the halophytes as part o ...
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New Technologies In Television
Number of Words: 1794 / Number of Pages: 7
... coming.
DVD is just starting to make a significant impact on the market. Estimates vary from about 600,000 to 1,000,000 console players ("living room" boxes used strictly to play movies) sold in the United States through the end of 1998. So far, the number of DVD drives in PCs is far smaller.
DVD technology can handle one or two layers of data per disc side. That makes for four sub varieties of DVD-ROM, the read-only version of this technology: DVD5 (single side, single layer) with a 4.7GB capacity; DVD9 (single side, dual layer), 8.5GB; DVD10 (dual side, single layer), 9.4GB; and DVD18 (dual si ...
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Natural Resources And Management
Number of Words: 532 / Number of Pages: 2
... have lived in North America for at least 12,000 years.
Archaeologists and historians have divided this time span into prehistoric and
historic periods. The prehistoric period extends from the earliest arrival of
humans in North America to the coming of the European explorers. The historic
period begins with the arrival of these explorers and continues up to the
present.
As you walk across public land, something on the ground catches your eye.
You pick up a piece of pottery or an arrowhead, wondering about the people who
made this artifact. Who were they? When did they live? How did they live? ...
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Effects Of Deforestation
Number of Words: 774 / Number of Pages: 3
... other non-forest animals and humans
(Dunbar, 1993). This unnatural extinction of species endangers the world's food
supply, threatens many human resources and has profound implications for
biological diversity.
Another negative environmental impact of deforestation is that it causes
climate changes all over the world. As we learned in elementary school, plant
life is essential to life on earth as it produces much of the oxygen that is
required for humans and other organisms to breathe. The massive destruction of
trees negatively effects the quantity and quality of the air we breathe which
has dir ...
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Coral Reefs 2
Number of Words: 1446 / Number of Pages: 6
... the largest biological structures on the planet, with the largest being the Great Barrier Reef covering over 2000 kilometers along the East Coast of Australia. The reef is said to be 500,000 to 2,500,000 years old and is said to be visible from the moon. There is only one problem with this beautiful structure and that is the carelessness of man. Silt from deforested lands and pollution from crowded coastlines choke them, and overuse by coal miners, fisheries, and even tourists deplete and destroy coral reefs.
There are many more factors that add to the destruction of the coral reefs, which if not sto ...
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Intranet 2
Number of Words: 1573 / Number of Pages: 6
... unless they have the security code to access them. Thanks to Internet technology, companies and other types of organizations are able to keep all of their information organized and easily accessible with a click of a button.
The Internet, how has it changed the world around us? Government, education, business is all wrapping around it. Is this because of all of the information on it, simplicity or is it the quickness, with a simple point and click and the information appears on the screen.
The first intention of the Web, as it is referred to, was not to create a sea of we ...
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Bipolar Disorders
Number of Words: 1763 / Number of Pages: 7
... loss of energy, feelings of worthlessness, guilt, difficulty thinking, indecision, and recurrent thoughts of death and suicide (Hollandsworth, Jr. 1990 ). The manic episodes are characterized by elevated or irritable mood, increased energy, decreased need for sleep, poor judgment and insight, and often reckless or irresponsible behavior (Hollandsworth, Jr. 1990 ). Bipolar affective disorder affects approximately one percent of the population (approximately three million people) in the United States. It is presented by both males and females. Bipolar disorder involves episodes of mania and depress ...
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Galileo Galilei "founder Of Modern Experimental Science"
Number of Words: 422 / Number of Pages: 2
... an instrument that could find the gravity of
objects. This instrument, called a hydrostatic balance, was used by weighing
the objects in water.
Galileo returned to Pisa in 1589 and became a professor in math. He
taught courses in astronomy at the University of Pisa, based on Ptolemy's theory
that the sun and all of the planets move around the earth. Teaching these
courses, he became more understanding of astronomy.
In 1592, the University of Padua gave him a professorship in math. He
stayed at that school for eighteen years. He learned and believed Nicolaus
Copernicus's theory that all of th ...
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Gas Laws (cemistry)
Number of Words: 2458 / Number of Pages: 9
... end must equal the pressure of the external atmosphere since the downward force on the two columns of liquid is then equal. When the liquid levels are unequal, the pressures must differ. The difference in pressure can be measured in units of length of the vertical column of liquid. The mm Hg, or its modern version the torr, originated in this use of the manometer. Mercury is particularly convenient for use in manometers (and barometers) because at room temperature it has low vapor pressure, does not wet glass, and has a high density. Other liquids such as linseed oil or water have also been used i ...
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