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» Browse Science and Environment Term Papers
Cancer 2
Number of Words: 1077 / Number of Pages: 4
... 70% of oncogenes are located in the weak points of the chromosomes-hereditary regions where the DNA molecule may break or its portions may be rearranged into new combinations. Actually most of the times, the nucleus and the DNA are constantly exposed to substances that may alter the genes. But these alterations are almost always prepared by intricate mechanism with the function of preventing havoc in the cell. But if these changes persist in a given cell, that altered gene will breed true. Such damage to the chromosome may remove the oncogene from the influence of the genetic control mechanisms ...
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Achondroplasia
Number of Words: 492 / Number of Pages: 2
... the spine should be monitored closely for signs of gibbous formation. In infancy, hypercephalus can occur. Infants head circumference should be monitored close . Monthly checks of head circumference must be monitored. Radiologic studies are indicated if head circumference raises to disproportionately, or if symptoms of hydrocephalus. Child’s pediatrician should have a copy of head circumference curves for children with . Radiologic procedures for dwarfism include head ultrasound, C-T scan, or MRI of the head. If intervention is necessary, a ventriculoperitoneal shunt is placed relieving the pressur ...
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Solar Cells
Number of Words: 1165 / Number of Pages: 5
... In electrical conductors, these bands are continuous but in
insulators and semiconductors there is an "energy gap", in which no
electron orbits can exist, between the inner valence band and outer
conduction band [Book 1]. Valence electrons help to bind together the atoms
in a solid by orbiting 2 adjacent nucleii, while conduction electrons,
being less closely bound to the nucleii, are free to move in response to an
applied voltage or electric field. The fewer conduction electrons there are,
the higher the electrical resistivity of the material.
In semiconductors, the materials from which sol ...
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The Greenhouse Effect
Number of Words: 604 / Number of Pages: 3
... Because of Venus's thick CO2
atmosphere, the planet's cloud-covered surface is hot enough to melt lead.
Water vapor is an important "greenhouse" gas. It is a major reason why
humid regions experience less cooling at night than do dry regions. However,
variations in the atmosphere's CO2 content are what have played a major role in
past climatic changes. In recent decades there has been a global increase in
atmospheric CO2, largely as a result of the burning of fossil fuels. If the
many other determinants of the Earth's present global climate remain more or
less constant, the CO2 increase sh ...
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Homo Aquaticus?
Number of Words: 2003 / Number of Pages: 8
... in humans than in apes. The neocortex (part of the
cerebral cortex), for instance is over three times larger than in chimps, even
though chimps and humans are pretty close to equal in body weight.
Each side of the brain is diveded by the central sulces into independant
halves. Just before the central sulcus lies the post-central cortex, where the
opposite body half (right side for left brain, left side for right brain). Just
in front of the central sulcus lies the pre-central cortex where the information
for the voluntary movements leave tthe brain. The pre-central area is called
primary m ...
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Dyslexia
Number of Words: 1175 / Number of Pages: 5
... fibers, the neurons travel to the cerebral cortex, which contains the language centers. Here they hit a barrier, stop and take their place in layers above previously deposited neurons, (which is normal). In the brains of dyslexics, how-ever, there are breaches in the barrier and the neurons enter them, leaving clumps of nerve cells called ectopias, which appear to interface with the brain's
ability to receive and transmit certain messages.
They are now finding that dyslexia can run in the family. If you or your other relatives have dyslexia that means that there is a chance that your own child cou ...
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Forensic Science
Number of Words: 1603 / Number of Pages: 6
... of the body) in cases of death, examine the medical evidence and lab reports,
study the victims history, and put all the information together in a report to be
turned in to the district attorney.
Medical examiners are usually physicians specializing in forensic
pathology, the study of structural and functional changes in the body as a
result of injury. Their training and qualifications most often include a medical
degree and an apprenticeship in a medical examiners office.
In the field of forensic science, there are many subspecialties. They
include odontology (the study of teeth), ...
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Cadmium And Sewage Sludge
Number of Words: 1239 / Number of Pages: 5
... For example, plants take up cadmium from soil; fish take up cadmium from water, and so on.
It is introduced into the environment from mining and smelting operations. Other cadmium emissions are from fossil fuel use, fertilizer application, sewage sludge disposal or galvanized pie corrosion. The largest source of these cadmium releases into the general environment is the burning of fossil fuels (such as coal or oil) or the incineration of waste materials. Cadmium may also escape into the air from zinc, lead or copper smelters. Working in or living close to a major source of airborne emissions such ...
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Historical Development Of Atomic Structure
Number of Words: 1213 / Number of Pages: 5
... masses), published his first attempt to
classify the known elements. His name was Mendeleyev, and he was a renowned
teacher. Because no good textbook in chemistry was available at the time, he
wrote the two-volume Principles of Chemistry (1868-1870), which later became a
classic. During the writing of this book, Mendeleyev tried to classify the
elements according to their chemical properties. In 1871 he published an
improved version of the periodic table, in which he left gaps for elements that
were not yet known. His chart and theories gained acceptance by the scientific
world when three element ...
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History Of Computers
Number of Words: 1146 / Number of Pages: 5
... side, and two on the other side of the wood on each wire.
Calculating Machines and their Inventors:
Through the centuries, several mathematical geniuses invented machinesto aid them in their calculations. The machines were never widely used and generally had no direct path to the later development of electronic computers. Example:
Pascal:
Blaise Pascal (1623-1662) a French matematician, invented the first mechanical adding machine at age 19 in 1642. He became tired of adding long columns of figures while helping his father, who had been appointed administrator of Rouen by Cardenal Richelieu ...
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