Accessibility links

Our World — 7 July 2007


MUSIC: "Our World" theme

Straight ahead on "Our World" ... sniffing around for early signs of Alzheimer's Disease ... how a huge prehistoric bird got off the ground ... and breaking down a gender stereotype about who talks more.

PENNEBAKER: "The two groups, men and women, use on average just about the exact same number of words — about 16,000 words per day."

Those stories, thinking about how chimps think, a desolate landscape teeming with life, and more. I'm Art Chimes. Welcome to VOA's science and technology magazine, "Our World."

You many know someone who has suffered with Alzheimer's Disease. It's a devastating brain illness, usually of old age, where patients lose their memories, suffer personality changes, and eventually die. There is no cure, and the treatments that are available are of limited help.

The descent into full-blown Alzheimer's is a gradual process, usually over many years, as protein structures called plaques and tangles develop in the brain. Early on, warning comes in the form of mild symptoms, such as occasional forgetfulness — a condition doctors call mild cognitive impairment.

But research indicates the seeds of dementia are planted even earlier, and a new study published this week has found one way of identifying people on the road to cognitive impairment — using their sense of smell.

WILSON: "We used a brief scratch-and-sniff test to assess the ability to identify familiar odors in about 600 older people without any evidence of cognitive impairment at the beginning of our study. These are all very common odors like paint thinner, banana, black pepper, things of that sort. Everyday odors."

Dr. Robert Wilson of the Rush University Medical Center in Chicago led the study. He and his team tested the people in the study every year for five years, to measure their cognitive abilities over time. Those who had more difficulty identifying odors at the beginning of the study were more likely to have developed problems with memory, naming objects, working with numbers, and so on.

WILSON: "During follow-up about 30 percent of them developed a syndrome called mild cognitive impairment, which is thought to be a precursor to Alzheimer's Disease. And those who had difficulty identifying odors were about 50 percent more likely to develop this syndrome than people who were able to identify familiar odors on the test at baseline."

Wilson says Alzheimer's Disease and the sense of smell are linked in parts of the brain, specifically the entorhinal cortex and the hippocampus.

WILSON: "And these are both parts of the brain that are part of the 'smell brain,' that is they help us interpret and process information about odors, and they're also among the earliest sites of Alzheimer's Disease pathology in the brain."

The scratch-and-sniff smell test Robert Wilson used is an inexpensive, commercially available test that can be given in less than five minutes. It might be a good screening mechanism that could identify future Alzheimer's Disease patients before they show any other symptoms. But I asked him, what's the point, since the treatment options today can, at best, only slow the progress of the disease.

WILSON: "If such a treatment is available, it will then become extremely important to identify people who have the disease but have not yet been devastated by it. Mild cognitive impairment, we now believe, precedes full-blown Alzheimer's Disease, but even then these people are already showing the main clinical manifestation of the disease, that is cognitive decline. So if we can identify people who are destined to get mild cognitive impairment and the dementia [of] Alzheimer's Disease before their cognition is dysfunctional, we think the chances of a disease-slowing treatment to be effective will be greatly enhanced."

The study by Robert Wilson and his colleagues appears this week in the Archives of General Psychiatry, which is published by the American Medical Association.

Scientists have used computer simulators — normally employed to design aircraft — to determine the flight characteristics of the largest flying bird that ever lived.

Six million years ago, if you were in what is now Argentina, you might have seen Argentavis soaring in the skies above. The giant, 70-kilogram bird had a wingspan of seven meters.

Using measurements from surviving fossils and from similar, smaller birds, Sankar Chatterjee at Texas Tech University and his colleagues concluded that the giant bird didn't have enough muscle mass to fly by wing-flapping alone, nor would it be able to take off from a standing start.

CHATTERJEE: "It could launch from a height and it would sort of go down and then sweep upwards. And it could glide very, very nicely. As I said, we found very excellent gliding power [but] it could not flap its wings. That we have also found, that it doesn't have the power."

For taking off from the ground, Chatterjee found, the bird was likely to have given itself a bit of a running start. It's the same technique used today by the albatross — and by human hang-gliders.

CHATTERJEE: "And it didn't have to flap a long time, just a few flaps, that would be fine. Because Argentavis had to go find the nearest thermal."

Exploiting those thermals — updrafts of warm air — is the way many of today's large birds, including condors and vultures, stay in the air.

According to Chaterjee's computer simulation, the Argentavis could fly at almost 70 kilometers per hour. His paper describing new findings about a very old bird were published online this week in the Proceedings of the National Academy of Sciences.

OK, time for a quick quiz. Who talks more, men or women?

I don't know how things are where you live, but here in the U.S., most people would probably say women utter more words in the course of a day than men do.

That's the stereotype. But how about some actual research?

Health reporter Rose Hoban uses just enough words to fill us in.

HOBAN: University of Texas psychology professor James Pennebaker has been doing research on people's daily activities for the past ten years. He's recorded the activities of about 400 college students, each over the course of days.

PENNEBAKER: "We have created a system where we are able to get people tape recorders that come on for 30 seconds and then go off for about 12 minutes. And we have people wear these for several days, and we've had these transcribed over the years in our various studies."

HOBAN: A few years ago, Pennebaker was reading an article that stated that women used thousands more words per day than men. That didn't strike him as true, based on what he'd seen in his research. So he went back to the data he'd collected to analyze how many words the men spoke versus the women.

PENNEBAKER: "[In] three of the studies we found that women use slightly more words, [and it] three studies, we found that men use slightly more words. On average the two groups, men and women, use on average just about the same number of words — about 16,000 words per day.

HOBAN: What Pennebaker says was interesting to him was that these similarities stretched across geography - some of his subjects were from Texas, some from Arizona and some from Mexico, and they participated in very different studies. He says he didn't see many major differences between generations either. But the differences showed up when he looked at what men and women talked about.

PENNEBAKER: "Women tend to talk about other people; they're interested in other human beings. They use lots of pronouns, for example, they talk about 'he, she, they.' Men, on the other hand, tend to be much more concrete. Males are interested in objects things. So while women are talking about who is dating who, men are talking about carburetors and dogs."
RH: and tools
PENNEBAKER: "And tools, we talk about tools, ha, ha, ha."

Pennebaker says the next thing he'd like to examine is how much time men and women spend talking to each other than among themselves. He says they already have the data to check that thesis out. He and his co-author Mattias Mehl published their research in the most recent issue of the journal Science. I'm Rose Hoban.

You'll note that Pennebaker's research involved university students. You might wonder if older men talk as much as older women. He says there's no reason to think the results would be different, but I wonder if ... No, I think I've said enough.

Time again for our Website of the Week, when we showcase interesting and innovative online destinations.

This time it's comprehensive plant catalog aimed at promoting land conservation in the United States. It's also a tremendous resource for anyone interested in botany, anywhere in the world, and you don't need to know a plant's scientific name to get started.

CLARK: "Oh, no. I mean, that's one of the exciting things about the Plants database. It has so many access points. If you're a botanist or a plant scientist, you can come into the plant database using scientific names, etc. But for the common user, it also allows you to search by common names."

That's Larry Clark of the Natural Resources Conservation Service of the U.S. Department of Agriculture, home of the Plants database at plants.usda.gov. Clark says that although the focus of the database is on American species, many plants are found throughout the world. In any event, there are some expansion plans to, shall we say, grow the site.

CLARK: "One of the things that we're going to do with the plant database next year is expand it to our partners in the Pacific basin, and we'll be adding more plants to the database as we bring those locations online."

Clark says there really isn't anything like this online resource for the flora of any other country, but they've been discussing partnerships and collaboration, so keep your eyes open for that.

One of the best parts of the Plants database is the online gallery of more than 30,000 photos and drawings of plants, which you're free to use for educational or scientific purposes.

What's especially valuable about this site, says Larry Clark, is that all the information has been vetted by top specialists in the field.

CLARK: "Most of the data come from top plant scientists and botanists around the world. So we're constantly mining the research environment, trying to pull in new data, new research and put that information into the plant database."

All that, plus the plant of the week, at our Website of the Week — the U.S. Department of Agriculture Plants database at plants.usda.gov, or get the link from our site, voanews.com/ourworld.

MUSIC: Clarence 'Gatemouth' Brown — "Six Levels Below Plant Life"

You're listening to VOA's fast-growing science and technology magazine, Our World. I'm Art Chimes in Washington.

From plants to primates, now, and chimpanzees. Our closest relatives, according to DNA analysis. We've seen the clever primates at the zoo, maybe, or on television. Endlessly fascinating to watch, but very few people understand how chimps think. Now, researchers at Ohio State University have found that chimpanzees that have been nurtured from birth by humans are more capable than other chimpanzees of using and understanding tools. With details of a paper published in the journal Animal Cognition, here's VOA's Adriana Salerno.

SALERNO: Sally Boysen has been studying chimpanzee cognition for over 30 years. A psychologist at Ohio State University, she has focused on chimps' ability to understand numbers and tools, their ability to recognize loved ones, and their seemingly altruistic natures. In the near future, she hopes to teach them to read simple English words. She also really loves her chimps.

BOYSEN: "I tell them all they're my favorite, one by one."

SALERNO: Boysen's most recent research compares how three very different groups of chimpanzees performed on two tests. One group was made up of chimpanzees who'd been raised under standard laboratory conditions, with no meaningful interactions with humans or each other. Another group contained chimps who had been raised under lab conditions and later taken to a sanctuary were they were able to interact with other chimps. Finally, there was Boysen's group, which resided at Ohio State and was comprised of so-called enculturated chimps, that is, chimps who had had highly social interactions with humans as well as other chimpanzees since they were very young.

BOYSEN: "They've also been immersed in all the kinds of opportunities that young children have in our human culture to interact with the kind of things that humans use every day, and opportunities to do things like turn on the water faucet and even flush the toilet, all the whole range of experiences that provide all kinds of information as children and young chimpanzees hypothesis-test in their environment to find out how the world really works."

SALERNO: Boysen says the two tasks in her study tested the chimps' ability to use and understand properties of tools to retrieve a food reward. The first task involved two different tools:

BOYSEN: "In this case they were given the opportunity to use one of two possible rakes: one rake had a sponge-like head, that really was not any good for pulling anything in and the other had a rigid wooden head. And food was placed in front of each of the rakes, and the chimps were then given the chance to choose one of the rakes to try and pull a little cup of yogurt toward them. And even our very youngest chimps, who were first tested at about two years of age, immediately pulled the rake that had the right functional properties. Nobody tried to use the floppy rake that had sponge strings for a head because, after all, that wouldn't work."

SALERNO: The second task was a more complicated version of the first, in which they had two identical tools to work with.

BOYSEN: "For the second task each of the two different tools had what were called hybrid heads: one side of the head was sponge-like and the other side was rigid so now they had two identical tools but we could place the yogurt cup in front of the sponge side of one rake and in front of the rigid side of the other, and they really had to understand the properties of the tools if they were going to be able to retrieve the yogurt. And, in fact, our chimpanzees were able to do that whereas the lab animals that were tested a few years ago failed both tasks."

SALERNO: The group of sanctuary chimps turned out to be the most informative for the researchers, since they performed well on the first task but failed in the second more complicated one.

BOYSEN: "And these sanctuary animals, then, could solve what was really the easy task, so through a process of trial and error they likely learned the perceptual characteristics, that is, which rake looked like what, and the one that looks like this functions so we'll keep using that."

SALERNO: Boysen says her study shows that chimps need to be raised and cared for in the best environment possible.

BOYSEN: "It should remind us that we need to make the best possible setting for any chimp in captivity regardless of where they are: in a laboratory, in a zoo, in the circus, that they need a very rich and stimulating environment to really maximize their potential, and health, and long life, in captivity."

SALERNO: Even though her primary interest is to study chimpanzees and their abilities to understand the world around them, Boysen believes her research, inevitably, has significant implications for the field of human cognition. This particular study, she says, suggests the importance of early cognitive development in children. If people want to maximize their child's potential, she says, they need to focus more on the early years between birth and age five. I'm Adriana Salerno.

Finally today, we take a virtual journey to some of the most forbidding-looking landscape on Earth.

With fields of cold, pockmarked lava left behind by volcanic eruptions, the Craters of the Moon National Monument really does look like a piece of the lunar landscape plopped down in the northwestern United States. But as we hear from VOA's Adam Phillips, this patch of Idaho state is not as lifeless as it seems.

PHILLIPS: On a cloudless summer day recently, Ranger Doug Owen, the resident geologist at the Craters of the Moon National Monument, adjusted his wide-brimmed hat and gazed out over what looks to be a lifeless moonscape — 30,000 hectares of sun-baked lava mounds:

OWEN: "On first look, it's a bunch of black rocks, some of them are jumbled — the stuff we call 'A-A', which in Hawaiian means 'hard on the feet' Then we have others that are smooth and have blue glass - things like the 'blue dragon flow.' This is gorgeous stuff! And we have other stuff that's been stretched and pulled, has little ridges and spines on the top. We have other lavas kinds of like a seashell. So there are lots of varieties these black rocks out here."

PHILLIPS: Geologists from all over the world come to Craters of the Moon National Monument to study the extraordinary variety of lava formations here.

OWEN: "Lava is nothing more than molten rock. And when it's on the surface we call it 'lava,' whether it's flowing as molten rock, or solidified. When it's beneath the surface it's called 'magma.'"

PHILLIPS: Magma or lava, almost all of it is made of the mineral basalt drawn from deep within the Earth's mantle, the geological layer that lies just beneath the earth's crust.

When magma escapes upward through cracks in the Earth's crust and spreads outward from volcanic cones, the surface lava cools first, and some of the underlying molten material withdraws. This leaves hollow spaces called "lava tubes," which can stretch for 20 kilometers or more. Geologist Doug Owen explains that over thousands of years the tubes trap wind-blown, mineral-rich soil, which can support an incredible abundance of life.

OWEN: "Quite often, we get visitors come to the desk [and ask,] 'how many plants have you got? A half-dozen or so?' Actually, as of this summer we have more than 800 species identified. There are 59 mammals here, 210 species of birds, 10 reptiles, four amphibians. We have 91 different butterflies that have been seen here if you really look. And that's what it takes. You have to really come out here, spend some time, and look closely and all of a sudden you find 'Wow! There is life out here!"

PHILLIPS: The mineral-rich soil indirectly feeds all life at Craters of the Moon. The local deer population thrives on the nutritious Antelope Bitterbrush, for example. And the coolness of the lava tubes allows pikas, small mammals similar to guinea pigs, to survive the heat.

OWEN: "Some of the animals have become darker colored — they are a sub-species — so that they have camouflage. They have a darker coat so they don't stand out and a bird of a prey, like an eagle flying over, says 'Oh! lunch!'"

PHILLIPS: Humans have also adapted well to this eerie landscape. Not the 19th century white pioneers who passed here and called it 'the Devil's Vomit." But the Shoshone and other Native Americans of the area who enjoyed its natural air-conditioning, trapped and ate its rodent-like rock chucks, and made arrowheads and scraping tools from the volcanic glass. Many of the local plants have medicinal properties. Indeed, Craters of the Moon is full of life. All you need to do, says Ranger Doug Owen, is pay attention.

OWEN: "Every place you look, there is a story. As a ranger, then, getting to get people to see the stories that are out there, it's a thrill. Because that's where the value lies — in getting people to see these inter-relationships. Because that's what we're going to need for the future. I mean, we have to think of the earth as a space ship. And it's the only space ship we've got."

PHILLIPS: The Craters of the Moon have been useful to real space ships more than once. In 1969, the Apollo astronauts spent time there studying the basalt formations they were likely to encounter on the Moon. More recently, geologists have done spectral analyses of the lava that will enable them to identify similar rock formations on comets and on Mars that might harbor life. For Our World, I'm Adam Phillips at the Craters of the Moon National Monument near Arco, Idaho.

MUSIC: "Our World" theme

That's our show for this week. We're always interested in your comments or your science questions. Email us at ourworld@voanews.com. Or use the postal address —

Our World
Voice of America
Washington, DC 20237 USA.

Rob Sivak edited the program. Eva Nenicka is the technical director. And this is Art Chimes, inviting you to join us online at voanews.com/ourworld or on your radio next Saturday and Sunday as we check out the latest in science and technology ... in Our World.

XS
SM
MD
LG