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Bad Science/Placebo/Background
Reference material by Wikibooks contributors. This retains its source identity and is not 411 news reporting.
The Placebo Effect: Do You Believe Your Teacher?
Background Notes
Caffeine
What’s another name for 3,7-dihydro-1,3,7-trimethyl-1H-purine-2,6,-dione? Yep,
CAFFEINE. Caffeine is the most popular drug in the world, and we’ve all been
known to try it at least once: in coffee, tea, cocoa, some soft drinks, some
drugs… …and in the popular treat, chocolate!
The actual source of caffeine is the coffee bean, tealeaf, kola nut and cacao pod.
Pure caffeine is odourless and has a bitter taste.
Caffeine is a central nervous system stimulant. In moderate doses, caffeine can:
increase alertness and speed of reactions
reduce memory
reduce fine motor coordination (giving you shaky hands!)
cause insomnia (sleepless nights!)
cause headaches, nervousness and dizziness
Caffeine enters the bloodstream through the stomach and small intestine and starts
to have its effects within fifteen minutes of ingestion. Once in the body, it takes
about six hours for one half of the caffeine to be eliminated.
Why is caffeine said to be addictive? One way to tell if someone "can’t live without"
that mocha latte or two shots of espresso is to take it away from them and see what
happens.
Typical withdrawal symptoms associated with caffeine include throbbing headaches
and aching muscles. These symptoms can occur within 24 hours after your last
“dose” of coffee.
One study has said that the minimum consumption of caffeine for you to be labelled
a coffee-addict is four cups of coffee per day. But it really depends on you! Some
people, if they don’t get that one cup in the morning, just can’t function at all!
In massive doses, caffeine is lethal. A fatal dose of caffeine has been calculated to be
more than 10g. To get this dose, you’d need to drink 80-100 cups of coffee in one
sitting - good news for coffee houses everywhere, but extremely difficult to do!
Did you know?
How Coffee was discovered…
“Legend has it that coffee was "discovered" around 850 AD in upper
Egypt by a goat herded named Khaldi. One night, Khaldi's goats did not
return home. When he found his goats, Khaldi saw them dancing
around a shrub with red berries (coffee beans). After Khaldi tried some
of the berries, he started to dance too. Khaldi spoke with some monks who
used the berries to make a drink and....coffee was born!”
(For further information see: http://faculty.washington.edu/chudler/caff.html)
How to take a pulse
“The easiest place to take a pulse is at the wrist, whether it is your own or someone
else’s. The fingers – not the thumb because the ball of the thumb has too strong a
pulse of its own – should be lightly but firmly pressed over the radial artery. You’ll
find it about 1 cm in from the thumb side of the wrist. Move your fingers around a
little if you can’t find it right away; you will soon feel the gentle throbbing. Count the
number of beats in 30 seconds, using a watch with a second hand to make sure you
time it exactly, then multiply by two. A healthy pulse can be very variable. The
average resting adult’s rate is 70 per minute but can range from 60-80; children
have a higher rate and a baby’s may be 140. If active or excited, the pulse rate will
increase.”
(From the book, How to Hold a Crocodile by the Diagram Group)
Longest time survived without a pulse
“The longest time a human has survived without a pulse in their vascular system is
three days. Julie Mills (UK) was at the point of death from severe heart failure and
myocarditis when, on 14 August 1998, cardiac surgeons at the John Radcliffe
Hospital, Oxford, UK, used a non pulsatile blood pump (AB180) to support her for
one week. Her heart recovered in this time and the pump was removed.”
Slowest heartbeat in a mammal
“The mammal that is presumed to have the slowest heartbeat of any warm–blooded
animal is the blue whale (Balaenoptera musculus), with between four and eight beats
per minute dependent on whether or not the whale is diving. By comparison the
average adult human heart beats at 70 beats per minute. Blue whales also have the
largest heart of any animal and their heartbeat can be heard up to 32 km (20 miles)
away underwater.”
(From the Guinness World Records 2005: 50th Anniversary Edition