AIR CUSHION VEHICLE (also known as HOVERCRAFT)
An amazing craft that operates above the surface of water or land while supported on a cushion of air 4-8 feet thick.
The air cushion is provided by a large fan that pushes air downward within a flexible skirt attached around the bottom of
the vehicle. This skirt makes the Hovercraft appear to be operating only a few inches above the surface. The vehicle
is moved forward by propellers mounted above the vehicle or by controlling the air exhaust through small openings around
the skirt. Breaking is controlled by reversing the pitch of the propeller or changing the direction of air.
Most Hovercrafts are designed for amphibious operation over water, marshy ground and
beaches and the operating controls are basically like those found in an airplane. A control wheel adjusts the pitch of
the vehicle and rudder pedals control side-to-side movement. The speed over water is limited by wave height and wind
speed. The operation of the Hovercraft is pretty much the same when moving from water to land or from land to
water. The air cushion prevents the hull from striking the ground when the terrain changes for a smooth, unnoticable
transition. Lifeguards and other lifesaving teams use them in emergency situations where time is crucial or
for victims that must remain immobile during transport from the rescue site to an ambulance waiting
at the beach. [Information is repeated under HOVERCRAFT]
ALLIGATOR One of two species that exist.
-The American Alligator (A. Mississipiensis) Confined to the United States,
living in fresh water swamps, lakes and byous. The Adult range from 6 to 20 feet long.
-The Chinese Alligator (A. Sinensis) Confined to the Yangtze River in China that
rarely grow longer than 15 feet long.
The Alligator has a broad flattened, rounded snout. They are often confused with crocodiles,
which have long, more rectangular snouts. The alligator's upper teeth overlap the bottom row. Its feet are webbed to
about the middle; the bony plates of the back are not connected together and the undersurface has no plates. They feed
on fish, frogs, snakes, turtles, birds, mamals and carrion. It is well known that they are extremely dangerous and attack
humans.
In spring both sexes search for a mate, often crying out. Courtship behavior is quiet, serious and
involves prolong stroking of the famale by the male. After mating, the male seeks his own territory while the female finds
a site nearby above the flood level to build a nest of mud and water plants. They lay 30-60 eggs in a clutch. The eggs
are covered with mud and are incubated by the heat of the sun while the famale guards the site. The eggs hatch in about 60
days. The female cares for the young, carrying them in her mouth or leading them around. They remain with her until the next
spring.
Alligators are hunted for both their highly prized hide, which is made into leather and for sport.
The creature started dwindled until it was placed on the endangered species list in 1967. After the alligator became numerous
again, they became bolder in the presence of humans. The building of roads and expressways have forced them into human domain.
They even started showing up on the lawns of humans to accept offerings of food. A decade later, it was taken off the endangered
species list and hunting was allowed in the US. (Also see CROCODILE)
ALLIGATOR LIZZARD (Gerrhonotus/family Anguidae)
Commonly called lizzards, there are four species known in the US. The Northern Alligator Lizzard
(G. Coeruleus) has the widest range from Southern British Columbia all the way to central costal California,
the Sierra Nevada and east into the Rocky Mountains. The lizzards are secretive with short legs, long tails and a conspicuous
lateral fold on the slender body. They live in moist, hilly country.
ALZHEIMER'S DISEASE A progressive degerative brain disease that usually affects
the elderly, robbing them of memory and functioning to live a normal life. There is also an early onset version of the
disease and although it usually appears around the 40's or 50's, victims can be as young as in their late twenties. The
early onset disease is usually genetically tied-those with one or both parents with the disease. Alzheimer's Disease
was discovered by German neuropathologist Alois Alzheimer (1864-1915) in 1906. Since people live much longer today than in
the past, the chance of developing it is greater. In the past, many people died before they reached old age and a chance to
develop the disease. Life expectacy for those with the disease is usually 5-15 years. With the medical advances in more
recent years has allowed some patients to live longer. Those with Alzheimer's Disease die as a result of a complication
rather than from the disease itself. The exact cause of the disease is not known. Confirmation of the disease
is done by autopsy. While research is conducted to develop a cure, other promising drugs have been used in effort to slow
down progression of the disease.
AUTISM The cause of this collection of symptoms is
still unknown. It begins in the first 30 months of life. Males are four times as likely as females to be autistic. Children
with the disorder are very withdrawn, unaffectionate and uninterested in people including parents and siblings.
The child behaves as if s/he is alone in the world. A language disorder is accompanied by this behavior. The child may learn
how to speak late or not at all. If speech develops, it is usually odd and limited. Very few children learn how to speak
past this stage.
