Conversation 1
Narrator:
Listen to a conversation between a student and the faculty advisor of the
campus newspaper .
Student
Hi! I talked to someone on the phone a couple of weeks ago, Anna , I
think it was?
Advisor
I'm Anna, the faculty advisor
Student
Oh, great! I'm Peter Murphy. You probably don't r e member me, but …
Advisor
No! No! I remember you . You're interested in working for the paper.
Student
Yeah, as a reporter .
Advisor
That's right. You're taking a jo urnalism class and you ’ ve done some
reporting before in high school, right?
Student
Wow, you have a good memory.
Advisor
Well we haven ’ t had many students applying lately so … so anyway, you
still want to do some reporting for us?
Student
Yeah, if you have room for me on the staff .
Advisor
Well we always need more reporters, but you know, we don't pay
anything, right?
Student
Yeah, I know, but I huh.. . I'd like the experience. It would look good on
my resume .
Advisor
Absolutely! Let's see . I think I told you that we ask prospective reporters
to turn in some outlines for possible articles .
Student
Yeah, I sent them in about a week ago, but I haven't heard anything back
yet, so, so I thought I'd stop by and see, but I guess you haven't looked at
them yet .
Advisor
Oh, Max, the news editor. He looks a t all the submissions
Student
Oh , so he hasn't made any decision about me yet?
Advisor
Well I just got here a few minutes ago... haven't been in for a couple of
days. Just give me a second to check my e-mail. Uh … here is a message
from Max. Let ’ s see. Well it seems you ’ ve really impressed him. He says it
would be wonderful if you could join our staff.
Student
Oh, great! When can I start?
Advisor
WeII, you turned in an outline on something to do with the physics
department?
Student
Yeah, they're trying to come up with ways to get more students to take
their introductory courses.
Advisor
Right, well , apparently, nobody else is covering that story , so he wants
you to follow up on it.
Student
OK. Uh … wha t the other outline I sent in, about the proposed increase in
tuition fees?
Advisor
Oh, it lo oks like we've got that covered
Student
So I am starting with an article about the physics department. I guess I'd
better get to work. Do you have any advice on how I should cover the
story?
Advisor
Well, Max will want to talk to you but I am sure he will tell you to find
out things like why the physics department's worried about enrollment.
Has the number of students been getting smaller in recent years? By
how much? What kinds of plans are they considering to address this
problem?
Student
Right, some of those issues are already in what I proposed .
Advisor
And you'll want to do some interviews, you know, what do the professors
think of the plans , what do the students think you get the idea but …
Student
But w ai t till I talk to Max before proceeding .
Advisor
Right, he'll cover everything you need to know to be a report e r for us .
Can you come back this afternoon? He will be here until 5 o'clock .
TPO 15 Lecture 1 Psychology
Narrator:
Listen to part of a lecture in a psychology class
Professor
For decades, psychologists have been looking at our ability to perform
tasks while other things are going on, how we are able to keep from
being distracted and what the conditi ons for good concentration are. As
long ago as 1982, researchers came up with something call ed the CFQ -
the Cognitive Failures Questionnaire. This questionnaire asks people to
rate themselves according to how often they get distracted in different
situations, like h um … .. forgetti ng to save a computer file because they
had something else on their mind or missing a speed limit sign on the
road. John?
John
I've lost my share of computer files, but not because I ’ m easily distracted.
I just forget to save them.
Professor
And that's part of the problem with th e CFQ. It doesn ’ t take other factors
into account enough, like forgetfulness. Plus you really can ’ t say you are
getting objective scientific results from a subjective questionnaire where
people report on themselves. S o it ’ s no surprise that someone
attempted to design an objective way to measure distraction. I t ’ s a
simple computer game designed by a psychologist named, Nilli Lavie. In
Lavie ’ s game, people watch as the letters N and X appear and disappear
in a certain area on the computer screen. Every time they see an N, they
press one key, and every time they see an X they press another, except
other letters also start appearing in the surrounding area of the screen
with increasing frequency which creates a distraction and makes the task
more difficult. Lavie observed that people ’ s reaction time slowed as
these distractions increased.
Student 2
Well that ’ s not too surprising, isn ’ t it?
Professor
No, it's not. It's the next part of the experiment that was surprising.
When the difficulty really increased, when the screen filled up with
letters, people got better al spotting the Xs and Ns . What do you think
that happened?
John
Well, maybe when we are really concentrating, we just don't perceive
irrelevant information . Maybe we just don't take it in, you know?
Professor
Yes, and that's one of the hypotheses that was proposed, that the brain
simply doesn't admit the unimportant information. The second
h ypothesis is that, yes, we do perceive everything, but the brain
categorizes the information, and whatever is not relevant to what we are
concentrating on gets treated as low priority. So Lavie did another
experiment, designed to look at the ability to concentrate better in the
face of increased difficulty. This time she used brain scanning equipment
to monitor activity in a certain part of the brain, the area called V5,
which is part of the visual cortex, the part of our brains that processes
visual stimuli .
V5 is the area of the visual cortex that's responsible for the sensation of
movement. Once again, Lavie gave people a computer-based task to do.
They have to distinguish between words in upper and lower-case letters
or even harder, they had to count the number of syllables in different
words. This time the distraction was a moving star f i el d in the
background, you know, where H looks like you are moving through space,
passing stars. Normally area of V5 would be stimulated as those moving
stars are perceived and sure enough, Lavie found that during the task
area of V5 was active, so people were aware of the moving star field.
That means people were not blocking out the distraction.
Student
So doesn't that mean that the first hypothesis y ou mentioned w as wr o ng,
the one that says we don't even perceive irrelevant information when we
are concentrating?
Professor
Yes that's right, up to a point, bu t that ’ s not all. Lavie also discovered that
as she made the task more difficult , V5 became less a ctive, so that
means that now people weren ’ t really noticing the star field at all. That
was quite a surprise and it approved that the second hypothesis – that
we do perceive eve rything all the time but the brain categorizes
distractions differently, well, that wasn't true eith er. Lavie thinks the
solution lies in the brain ’ s ability to accept or ignore visual information.
She thinks its capacity is limited. I t ’ s like a highway. W hen there are too
many cars, traffic is sto pp e d. No one can get on. S o when the brain is
loaded to capacity, no new distractions can be perceived . Now that may
be the correct conclusion for visual distractions, but more research is
needed to tell us how the brain deals with, say, the distractions of solving
a math problem when we are hungry or when someone is singing in the
next room.
TPO 15 Lecture 2 Geology
Narrator:
Listen to part of a lecture in a geology class .
Professor
As geologists , we examine layers of sediment on the Earth' s surface to
approximate the dates of past geologic time periods. Ah sediment as you
know i s material like sand , gravel, fossil fragments that is transported by
natural processes like win d , water flow or the movement of glaciers .
So sediment is transported and then deposited and it forms layers on the
Earth ’ s surface over time. We examine these layers to learn about
different ge ologic time periods including when they began and ended.
For example, from about 1.8 million years ago to around 11 thousand
years ago was the Pleistocene epic. The Pleistocene epic was an ice age.
During this epic, sediment was made by the kind of erosion and
we athering that happens when the climate is colder, and part of those
sediments are fossils of plants and animals that lived at that time.
The Holocene epic followed the Pleistoce ne epic when the Earth ’ s
climate warmed up around 11 thousand years ago. The Holocene e pic is
characterized by different sediments, ones that form when the climate is
warme r. Because the climate changed, the types of plants and animals
changed also. Holocene sediments contain remnants of more recent
plants and animals, so it's pretty easy to diffe rentiate geologically
between these two epics.
Now there is growing evidence that the presence of humans has altered
the earth so much that a new epic of geologic history has began – the
Anthropocene epic, a new human-influe nced epic. T his idea that we ’ ve
entered a new Anthro-pocene epic was first proposed in 2002. T he idea
is that around the year 1800 CE the human population became large
enough, around a billion people, that its activities started altering the
environment. T his was also the time of the industrial revolution, which
brought a tremendous increase in the use of fossil fuels such coal. The
exploitation of fossil fuels has brought planet wide developments:
industrialization, construction, uh, mass transport. And these
developments have caused major changes like additional erosion of the
Earth ’ s surface and deforestation. Also, things like the damming of rivers ,
has caused increased sediment production, not to mention the addition
of more carbon dioxide and methane in the atmosphere .
Naturally all these changes show up in recent sediments. And these
sediments are quite different from pre year 1800 sediment layers.
Interestingly there's some speculation that h umans started having a
major impact on Earth much earlier, about 8000 years ago. That's when
agriculture was becoming widespread. Early farmers started clearing
forests and livestock produced a lot of extra methane. But I want to
stress this is just a hypothesis. The idea that early humans could have
had such a major effect, well I'm just not sure we can compare it with
the industrial age. Geologists in the far future will be able t o examine the
sediment being laid down today, whereas right now we can say that yes,
human impact on the Earth is clear: It'll be future researchers who have
a better perspective and will be able to really draw a line between the
Holocene and the Anthropocene epics
TPO 15 Conversation 2
Narrator
Listen to part of a conversation between a student and her biology .
Professor
Hi Samantha, how did your track meet go?
Samantha
Great! I placed first in one race and third in another.
Professor
Congratulations ! You must practice a lot.
Samantha
Three times a week pre-season, but now that we ’ re competing every
weekend, we practice 6 days a week from 3:30 till 5:00.
Professor
Athletics place a heavy demand on your time, don ’ t they?
Samantha
Yeah, but I really love competing, so …
Professor
You know I played soccer in college and my biggest challenge, and I
didn ’ t always succeed, was getting my studying in during soccer season.
Are you having a similar …
Samantha
No, I … I really do make time to study. A nd I actually study more for this
class than I do for all my other classes. B ut I didn ’ t see the grade I
expected on my mid-term exam, which is why I came by.
Professor
Well, you "didn't do badly on the exam, but I agree it did not reflect your
potential. I say this because your work on the lab project was exemplary.
I was so impressed with the way you handle the microscope and the
samples of onion cells, and with how carefully you observed and
diagramed and interpreted each stage of cell division. And I don't think
you could have done that if you hadn't read and understood the chapter.
I mean it seemed like you really had a good understanding of it.
Samantha
I thought so too, but I missed some questions about cell division on the
exam
Professor
So what happened?
Samantha
I just sort of blanked out, I guess. I had a hard time remembering details.
It was so frustrating.
Professor
Alright, let's back up. You say you studied, where, at home?
Samantha
At my kitchen table actually .
Professor
And that's supposed to be a quiet environment?
Samantha
Not exactly. My brother and parents try to keep it down when I am
studying, but the phone pretty much rings off the hook, so …
Professor
So you might try a place with fewer distractions, like the library …
Samantha
But the library closes at mid-night, and I like to study all night before a
test, you know, so everything is fresh in my mind. I studied six straight
hours the night before the mid-term exam . T hat ’ s why I expected to do
so much better.
Professor
Oh ok. Y ou know that studying six consecutive hours is not equivalent to
studying one hour a day for six days.
Samantha
It isn ’ t?
Professor
No. There is research that shows that after about an hour of intense
focus, your brain needs a break. It needs to, you know, shift gears a little.
Your brain's ability to absorb information starts to decline after about the
first hour. So if you are dealing with a lot of new concepts and vocabulary,
anyway, if you just reviewed your notes, even 20 minutes a day, it'd be
much better than waiting until the night before an exam to try and
absorb all those details .
Samantha
Oh, I didn't realize .
Professor
Think of your brain as: a muscle. If you didn't practice regularly with your
track team, and then tried to squeeze in three weeks worth of running
practice just the day before a track meet, how well do you think you'd
perform in your races?
TPO 15 Lecture 3 Art History
Narrator:
Listen to part of a lecture in an art history class .
Professor:
Now in Europe in the Middle Ages before the invention of printing and
the p r inting pres s, all books, all manual scripts were hand-made. And the
material typically used for the pages was parchment, which is animal skin
that stretched and dried under tension, so it bec o me s really fat and can
be written on . During the 1400s, when printing was being developed,
paper became the predominant material for books in Europe, but prior
to t hat, it was parchment . Parchment is durable, much more so than
paper, and it could be reus ed which came in handy since it was a costly
material and in short supply. So it wasn ’ t uncommon for the scribes or
monks who produce the manual scripts . Ah, remember before printing
books were made mainly in monasteries . Well, the scribes often recycled
the parchment that ’ d been used for earlier manual scripts. They simply
erased the ink off the parchment and wrote something new in its place
A manual script page that was written on, erased and then used again is
called a palimpsest . Palimpsests were created, well, w e kn ow about two
methods that were used for removing ink from parchment. In the late
Middle Ages, it was customary to scrape away the surface of the
parchment with an abrasive, which completely wiped out any writing
that was there. But earlier in the Middle Ages, the original ink was
usually removed by washing the used parchment with milk. That
removed the ink. But with the passing of time, the original writing might
reappear. In fact , it might rea pp ear to the extent that scholars could
make out an even deci p her , the original text. Perhaps, the most famous
example is the Archimedes' palimpsest.
Archimedes li v e d in G re ece around 200 BCE, and as you probably know,
he's considered one of the greatest Mathematicians who ever lived, even
though , many of his writings had been lost , includi ng what many now
think to be his most important work called The Method . But in 1998, a
book of prayers from the Middle Ages sold in an art auction for a lot of
money, more money than anyone would pay for a damaged book from
the 12th century. Beautiful or not, why? It had been discovered that the
book was a palimpsest, and beneath the surface writing on the manual
script laid, guess what? Mathematical theorems and diagrams from
Archimedes
Archimedes' writings were originally done on papyrus scrolls. Then in the
10 th century, a scribe made a copy on parchment of some of his texts and
diagrams including, as it turns out, The Method . This was extremely
fortunate, since later on, the original papyrus scrolls disappeared. About
200 years later in the 12 th century, this parchment manual script became
a palimpsest when a scribe used the parchment to make a prayer book.
So the pages, the pieces of parchment themselves, had been preserved.
But the Archimedes' text was erased and written over, and no one knew
it existed. It wasn't until 1906 that a scholar came across the prayer book
in a library and realized it was a palimpsest, and that the underlying layer
of texts could only have come from Archimedes. That was when his work
The Method was discovered for the first time .
Um... the palimpsest then went through some more tough times, but
eventually it ended up in an art auction where was bought and then
donated to an art museum in Baltimore, for conservation and study. To
avoid further damage to the manual script, the research team at the art
museum has had to be extremely selective in their techniques they used
to see the original writing. They've used ultraviolet light and some other
techniques, and if you're interested in that sort of thing, you can learn
more about it in an art conservation class. But act ually, it was a physicist
who came up with a method that was a breakthrough. He realized that
the iron in the ancient ink would display if exposed to a certain X-ray
imaging method, and except for small portions of the text that couldn't
be deciphered, this technique's been very helpful in seeing Archimedes'
texts and drawings through the medieval over w riting .
TPO 15 Lecture 4 Biology
Narrator:
Listen to part of a lecture in a biology class.
Professor:
OK. We've been talking till now about the two basic needs of a biological
community – an energy source to produce organic materials, you know
ah, food for the organism , and the waste recycling or breakdown of
materials back into inorganic molecules, and abo ut how all this requires
photosynthesis when green plants or microbes convert sunlight into
energy and also requires microorganisms, bacteria, to secrete chemicals
that break down or r ecycle the organic material to complete the cycle
So, now we are done with this chapter of the textbook, we can just
review for the weekly quiz and move on to the next chapter, right? Well,
not so fas t. First, I ‘d like to talk about some discoveries that have
challenged one of these fundamental assumptions about what you need
in order to have a biological community.
And, well, there actually were quite a few surpris es. I t all began in 1977
with the exploration of hydrothermal vents on the ocean floor.
Hydrothermal vents are cracks in the Earth ’ s surface that occur, well, the
ones we are taiking about here are found deep at the bottom of the
ocean. And these vents on the ocean floo r, they release this incredibly
hot water, 3-4 times the temperature that you boil water at be cause this
water has been heated deep within the Earth. Well about 30 years ago,
researche rs sent a deep-sea vessel to explore the ocean ’ s depth, about 3
kilometers down, way deep to ocean floor, No one had ever explored
that far down before. Nobody exp ected there to be any life down there
because of the conditions. First of all, sunlight doesn't rea ch that far
down so it ’ s totally dark. There couldn ’ t be any plant or animal life since
there's no sunlight, no source of energy to make food. If there was any
life at all, it ’ d just be some bacter ia breaking down any dead materials
that might have fallen to the bottom of the ocean . And?
Student 1
And what about the water pressure? D idn ’ t we talk before about how
the deeper down into the ocean you go, the greater the pressure?
Professor
Excellent point! And not only the extreme pressure, but also the extreme
temperature of the water around these vents. If the lack of sunlight
didn't rule out the existence of a biological community down there then
these factors certainly would, or so they thought.
Student 2
So you are telling us they did find organisms that could live under those
conditions?
Professor:
They did indeed, something like 300 different species
Student 1 But... but how could that be? I mean without sunlight, no energy, no no …
Protessor:
What they discovered was that microorganisms, bacteria, had taken over
both functions of the biological community - the recycling of waste
materials and the production of energy. They were the energy source.
You see, it turns out that certain microorganisms are chemosynthetic -
they don't need sunlight because they take their energy from chemical
reactions
So, as I said, unlike green plants which are photosynthetic and their
energy from sunlight, these bacteria that they found at the ocean floor,
these are chemosynthetic, which means that they get their energy from
chemical reactions. How does this work?
As we said, these hydrothermal vents are releasing into the ocean depth
this intensely hot water and here is the thing, this hot water co ntains a
chemical called hydrogen sulfide, and also a gas , carbon dioxide. Now
these bacteria actually combine the hydrogen sulfide with the carbon
dioxide and this chemical reaction is what produces organic material
which is the food for larger organisms. The researchers had n ever seen
anything like it before.
Student 2 : : : :
Wow! So just add a chemical to a gas, and bingo, you ’ ve got a food
supply?
Professor
Not just t h at! W hat was even more surprising were all the large
organisms that lived down there. The most distinctive of these was
something called the tube worm. H ere, let me show you a picture .
The tube of the tube worm is really, really long. They can be up to one
and half meters long , and these tubes are attached to the ocean floor,
pretty weird looking, huh?
And another thing, the tube worm has no. mouth, or digestive organs. So
you are asking how does it eat? Well, they have these special organs that
collect the hydrogen sulfide and carbon dioxide and then transfer it to
another organ, where billions of bacteria live. These bacteria that live
inside the tube worms, the tube worms provide them with hydrogen
sulfide and carbon dioxide. And the bacteria, well the bacteria kind of
feed the tube worms through chemosynthesis, remember, that chemical
reaction I described earlier.