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Text 1
Are Dreams as Vital as Sleep?
More about dreams
Do Spider and Tiger dream? Yes. There is evidence that almost
all mammals do. But animal dreams probably lack the storylike
quality of some human dreams. Dreams probably help animals
learn and remember skills needed for survival. So a kitten
that learns to catch mice might dream about the skill, helping
its brain to store the memory. In Are Dreams as Vital as
Sleep?
the writer seems to be establishing a sort of relationship
between the brain and dreams.
According to the recent researches,
dreams result from random bursts of activity in a brain stem
area that regulates breathing and other basic bodily
functions. These brain stem blasts zip to the frontal brain
during periods of rapid eye movement (REM) sleep, when the
entire brain becomes nearly as active as when a person is
awake. Dreams most often occur during REM sleep. A
slumbering individual enters REM sleep about every 90
minutes. Three essential processes during REM sleep make it
the prime time for dreaming. First, brain stem activity
surges and sets off responses in emotional and visual parts
of the brain. Second, brain regions that handle sensations
from the outside world, control movement, and carry out
logical analysis shut down. Third, brain stem cells pump out
acetylcholine, a chemical messenger that jacks up activity
in emotional centers. At the same time, two
neurotransmitters essential for waking activity—noradrenaline and serotonin—take a snooze.
REM sleep conducts far more important business than dreaming.
Its central functions may include supporting brain development,
regulating body temperature, fortifying the immune system,
and fostering memories of recently learned information. To
dream, the brain—both in and out of REM sleep—stimulates
a frontal-lobe system that orchestrates motivation and the
pursuit of goals and cravings, one British scientist proposes.
A neurotransmitter called dopamine ferries messages in the
brain's motivation system. If the REM state in one form or
another saturates much of sleep, then the brain stem and related
emotional centers create dreams throughout the night.
Language notes
1.
It even occurred to us that it might be connected with the
very special role that whiskers play in the cat, and we actually
tried cutting them off to see whether this might have some
effect.
It even occurred to us means an idea comes to our mind.
Tried cutting them off means to cut them off to see the result
of.
2.This
research was carried out in collaboration with Kleitman and
Dement in the United States, among others.
Among others means among other people.
3.We
can identify, to within one second, the instance he begins
to dream and the instance his dream ends.
The preposition "to" is used here to show degree.
4.The
center controlling muscular tone, which is no bigger than
a grape seed, lives his dreams.
The word live can also be used as a transitive verb meaning
to "to experience ,or cause to become vivid"
5.
It is not a coincidence that the physician chosen to participate
in the first trip to the moon planned by the Americans is
a specialist in sleep.
It is not a coincidence that means " it is not by chance
that."
Text 2
Mind over Time
About the author
Dr. Mark Caldwell, Professor of Literature, Fordham University,
is a voluminous writer. He is the author of The Last Crusade:
The American War on Consumption, 1880- 1954. Dr.
Caldwell has written extensively on the texts and symbols of
the American response to tuberculosis. Mark Caldwell's interest is wide-ranged. He once published
many articles in Discover which include the famous Mind over
Time and Polly wanna PhD?.
About the text
Recent discoveries are uncovering the once-mysterious workings
of the body's biological clocks. Apparently at the center
of timekeeping, a cluster of nerve cells called the suprachiasmatic
nucleus (SCN), located just above the optic nerves' convergence
at the base of the brain, depends on light for what circadian-clock
researchers call entrainment—synchronizing the inner clock
with the cycles of light and darkness in the external world.
The SCN is a pair of structures, divided between the right
and left brain hemispheres, and each consists of about 10,000
densely packed neurons, according to Steven Reppert of Harvard
University. The development of therapies based on the workings
of circadian clocks is discussed.
Language notes
1.It
came up on me gradually, over time.
The phrase "over time" is equivalent to "with the change of
season".
2.Some
SAD sufferers, he says, simply gravitate toward a lifestyle
that accommodates the disease.
In this sentence the phrase "gravitate toward" means to be
attracted by and move gradually toward.
e.g. In the 19th century, industry gravitated towards the
north of England.
3.The
bleary-eyed miseries of jet lag are a familiar example of
what can happen when you're hurled across time zones and your
personal clock bumps out of sync with the pace of the rest
of the world.
In the sentence, the phrase "out of sync" means not going
properly together. The word "sync" refers to a correct working
arrangement or synchronization.
4.
Baby Bens: Baby Bens refers to those clocks manufactured
by Westclox. The Big Ben alarm clock was first sold in 1909
and has evolved through many case style and movement changes.
The Baby Ben was first sold in 1910 and has evolved in a similar
way.
5.These
photoreceptors are different from the rods and cones used
to perceive light hitting the retina.
Rods and cones:视杆与视锥.
Used to perceive light hitting the retina is a past
participle phrase used as an attributive.
Hitting the retina is also used as an attributive modifying
light.
6.
Not everyone has the problem... When natural light is scarce,
the best way to reset the inner clock is with a burst of artificial
light......
Note the useful expressions in this paragraph:
In tune with:与……谐调.
In synchrony with:与……同步，其反义词是out of sync.
In step with:与……节奏一致.
7.
Underneath it all is one clock, the clock in the cell.
The word "it" refers to the single neuron mentioned in the
above sentence.
8.
In later treatments Lewy worked the dosage down to two hours
of exposure a day at an intensity of 2,500 lux, which approximates
the strength of natural light just after the sun has fully
risen.
Lux : a unit used to measure light, its plural form
is lux(es) or luces.
9.
Within days, Jason's depression dissipated, his sleep habits
returned to normal, and the sweet tooth cravings became somewhat
less pronounced.
Somewhat less pronounced means not frequently mentioned.
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