MUSIC: "Our World" theme
This week on "Our World" ... Making gasoline out of plants ... New findings about lighting up those so-called "light" cigarettes ... and if clothes make the man, as they say, then feathers make the bird ...
SAFRAN: "When we manipulate a male's color to look darker, he does better, he attracts more mates. And he has more offspring. This is the currency of evolution. Having a number of babies."
A bird's eye view of the mating game, plus falling snow ... on Mars, and more. I'm Art Chimes. Welcome to VOA's science and technology magazine, "Our World."
Hubble part failure delays shuttle repair mission
We have a pile of space news this week, so let's start with that.
On Monday, NASA disclosed a problem on the earth-orbiting Hubble Space Telescope. A piece of onboard equipment has failed, preventing the telescope from sending scientific data back to Earth.
Hubble manager Preston Burch told reporters in a teleconference that technicians have been working on the problem —
BURCH: "And all the testing and all the efforts so far to restore it have indicated that it has totally failed."
Like a lot of space hardware, this device, the Science Data Formatter, has some built-in redundancy. And NASA will switch to its backup circuits over the coming days. But the backup has been in space for almost two decades, and if it fails, the Hubble telescope will be useless.
So now, the plan is to have astronauts replace the Science Data Formatter when they do other repairs and upgrades on a shuttle mission that was scheduled for mid-October. Because it will take some time to get the replacement Science Data Formatter tested and ready, the shuttle repair mission will be delayed ... probably until mid-February at the earliest.
Although this seems like a setback for Hubble, NASA official Ed Weiler said it's a good thing the Hubble failure happened before the space shuttle repair mission.
WEILER: "Think about if this failure had occurred two weeks after the servicing mission. We had just put two brand-new instruments in and thought we extended the life for 5-10 years and this thing failed after the last shuttle mission to Hubble. So in some sense, if this had to happen, it couldn't have happened at a better time."
Phoenix lander sees snow falling on Mars
To Mars next, where NASA's Phoenix lander has been finding various indications of ice on the Martian surface. And Jim Whiteway, the lead scientist for Phoenix's weather instruments, says they've now detected falling snow.
WHITEWAY: "The ice crystals would be starting out at about a height of about four kilometers. And by the end of the measurement, in this case, they have fallen all the way down to about to two-and-a-half kilometers ... So that is snow is falling from the clouds and we are going to be watching very closely over the next month for evidence that snow is actually landing on the surface."
Whiteway told reporters that apparently the snow they saw vaporized before reaching the surface of Mars.
The discovery was based on data sent back by one of the space probe's instruments called lidar, which works something like radar except it uses laser light rather than radio waves.
A pretty active week for NASA, which on Wednesday celebrated its 50th anniversary.
And as they say on TV commercials — but wait, there's more...
NASA readies spacecraft for Mercury fly-by
On Monday a U.S. space probe will fly past Mercury in one of a series of close encounters with the closest planet to the Sun.
The flybys are really navigational moves aimed at getting the Messenger spacecraft into orbit around Mercury in 2011. But as it swoops just 200 kilometers from the surface of Mercury, the spacecraft's instruments will race to capture pictures and other information about the solar system's smallest planet. VOA's Jessica Berman has details.
BERMAN: Monday's rendezvous with Mercury is the second of three flybys by Messenger, which stands for Mercury Surface, Space Environment, Geochemistry and Ranging.
Messenger, which was launched in 2004, is using the encounters as critical gravity assists to help ease the spacecraft into Mercury's orbit in 2011.
The flyby will bring Messenger very close to the planet's surface, according to Daniel O'Shaughnessy, head of guidance and control of the mission.
O'SHAUGHNESSY: "Messenger will whiz 200 kilometers above the planet. During this time, Messenger will train its suite of miniaturized instruments at portions of the planet never before seen at such a distance."
BERMAN: NASA scientists say there will be a seventeen minute black out, during which time Messenger's instruments are expected to capture some 1,200 images of Mercury's rocky surface.
NASA officials say the second Messenger encounter with Mercury will follow up data gathered during Messenger's January flyby, during which scientists learned new details about an enormous impact crater, volcanic structures, and lava fields.
Sean Solomon is the mission's principal investigator.
SOLOMON ACT: "What we're expecting is to see additional examples of the kind of geological features, the kinds of geological units characterized by colors and shapes that we've seen so far."
BERMAN: Mission managers say Messenger's second swing-by of Mercury will reveal 30 percent of the planet. Between Messenger's January rendezvous and images sent back by the Mariner missions 33 years ago, space scientists say they will soon glimpse 95 percent of Mercury's surface.
The space probe will fly past Mercury one more time in September 2009 before settling into permanent orbit in three years. Jessica Berman, VOA News, Washington.
Research advancing on 'green' gasoline from plants
You probably have heard about ethanol and biodiesel, liquid fuels made from plants rather than petroleum. They use a renewable resource, and burning them doesn't contribute to global warming.
Ethanol can be blended with gasoline and run in an unmodified vehicle, but add enough ethanol to the mix and you need to make changes to the engine.
So why can't you make gasoline directly from plants? Well, it turns out that you can. At least that's what some promising research programs suggest, according to William Schultz of the National Science Foundation and the University of Michigan.
SCHULTZ: "What we are going to do is change a biofuel, such as poplar, switchgrass, corn stover (which is just the part of the corn we don't normally eat) and others, and by one of three processes — gasification, pyrolysis, or deconstruction — produce precursors to green gasoline."
Those "precursors" are chemical molecules similar to what is found in crude oil, molecules that can be refined to produce gasoline.
Schultz mentioned that there are at least three different ways to get from plants to gasoline. Gasification is the oldest, and has been used to convert coal to gasoline, but it is expensive and not very efficient.
Pyrolysis uses heat and chemical catalysts to promote the conversion of plants to gasoline. It is efficient and can even use waste paper as its raw material, but so far can only produce some components of gas.
A third process uses sugars, which can be easily derived from plants. It is being developed at a company called Virent Energy Systems. Company founder Randy Cortright says their process produces gasoline that's actually better than what you can buy at a service station.
CORTRIGHT: "We did an analysis of this, of our green gasoline versus just standard unleaded gasoline we got at the gasoline station across the street. We have the same components in there. In fact, it's actually got a higher octane and some preferable blending component that you can utilize.
Cortwright says Virent's plant-based process can also produce chemicals that can be used to make plastics and pharmaceuticals, just like petroleum. It can also produce jet fuel, noting that ethanol is a poor choice for aviation fuel since a liter of ethanol packs less energy than a liter of gas.
CORTRIGHT: "You don't have the energy content there. While you can burn ethanol in your automobile, you would not take ethanol and put it on an airplane because it has a lower energy content. And ideal fuel right now is a hydrocarbon fuel, and what we're looking at is, the hydrocarbon doesn't have to come from petroleum. It can come from biomass, and that's what we're doing with our process."
For its briefing on green gasoline, the National Science Foundation decorated a meeting room with some of the plants that might fuel the 21st century energy economy.
HUBER: "If you look at some of these plants around here, what we're trying to do is take the non-edible portion of the plants. This is the fastest [growing] and most abundant form of plant material, and produce green gasoline, green diesel, and green jet fuel.
University of Massachusetts chemical engineering professor George Huber pointed out that it's not enough just to turn plant biomass into gasoline, you have to do it efficiently and economically to compete with petroleum.
HUBER: "Making a fuel — it's a commodity. You have to have a very highly optimized and integrated process to make a profit. You're competing against petroleum oil that's been around for over 100 years, and the petroleum industry has developed and they've learned how to economically refine crude oil. Now we need to learn how to economically refine biomass resources."
Like gasoline made from crude oil, burning green gasoline produces carbon dioxide, a greenhouse gas. But there's virtually no net impact on climate because the CO2 released is the same CO2 absorbed from the atmosphere when the plant was growing.
Although research on green gasoline is still ongoing, William Schultz of the National Science Foundation pointed out that it is building on technologies that have been around for a long time.
SCHULTZ: "So it's not a technology that's 20 years away. I think we think it's 5-10 years away."
Incidentally, Schultz points out that while the chemical process for making green gasoline still has a long way to go, so does the breeding of plants specifically designed to be turned into fuel. Breeding has improved wheat, corn, and other crops over thousands of years. Improvements can also be expected in the undomesticated plants that would go into biofuels.
Large, industrial facilities may one day be making gasoline, jet fuel, and maybe even plastics and medicines from plants. And smaller facilities might end up right where biomass is grown.
SCHULTZ: "Even a farm that produces primarily food crops, just its waste product might be enough to produce more energy than they need. Perhaps you could do enough energy from the waste products from the food production that you could make a farm energy-self sufficient, even if it's not a biofeedstock energy producer."
William Schultz of the National Science Foundation, which hosted the seminar on green gasoline.
Nicotine, even in light cigarettes, affects brain
Smoking has been declining in many industrialized countries in recent decades. But the global picture is different, with the number of smokers on the rise.
With this has come an increase in the number of people suffering from heart and lung diseases, and cancers. Many people would like to quit, but it's very difficult — in part because tobacco is extremely addictive. Some people try to quit by switching to low-nicotine, or 'light' cigarettes. But as we hear from health reporter Rose Hoban, that's not very effective.
HOBAN: Researcher Arthur Brody, with the University of California at Los Angeles, says the primary addictive substance in tobacco is nicotine. It's only one of thousands of chemicals in tobacco smoke. But when a person lights up, nicotine floods chemical receptors in the brain.
BRODY: "Nicotine occupies these receptors and desensitizes them so essentially turns them off. And so, for some reason, this results in all of the reasons that people smoke, you know the pleasure that they feel, or the reduced anxiety or the little boost in their mood sometimes.
HOBAN: One strategy people use to quit smoking is to use low-nicotine cigarettes. Brody recently studied these co-called light cigarettes and their effects on smokers' brains. First, he had people smoke regular cigarettes while they were in a brain scanner. He could track how many nicotine receptors in the brain were affected.
BRODY: "If they only took one or two puffs of the cigarette, that occupied 50 percent of this type of nicotine receptor in the brain. Whereas if they smoked a full cigarette, it occupies about 88 percent of those receptors."
HOBAN: Then Brody gave people so-called low-nicotine cigarettes ...
BRODY: "… which have even less nicotine than light cigarettes. Even those little-nicotine cigarettes occupied 77 percent of these receptors. And so the majority of these receptors get occupied very easily with very small amounts of nicotine in cigarettes."
HOBAN: Brody found that even with cigarettes that are supposedly 'de-nicotinized,' about a quarter of the nicotine receptors in smokers' brains were occupied.
BRODY: "The problem is that sometimes people buy a light cigarette and they inhale them more deeply, or they smoke more of them, and so there really is no benefit if they do them that way."
HOBAN: Brody says these findings mean that many smokers who think they're weaning themselves off tobacco by smoking so-called 'light' or low nicotine cigarettes might not actually be getting any benefit from them. He says that people using these light cigarettes to quit need to be careful about how much they smoke, or they may need to use a method that reduces the amount of nicotine they receive in a more reliable way, such as by using nicotine patches.
Brody's research is published in the International Journal of Neuropsychopharmacology. I'm Rose Hoban.
Linux distributions on our Website of the Week
Time again for our Website of the Week, when we showcase interesting and innovative online destinations.
This time, it's a guide to the wide range of software packages known as Linux distributions - the free alternatives to Microsoft Windows or Apple's Mac OS that also include a vast array of professional quality application programs for your desktop computer.
BODNAR: "DistroWatch is a website, it's a portal, it's a news and reference site about Linux distributions."
Ladislav Bodnar is the founder of DistroWatch.com, perhaps the Web's most complete survey of the different flavors of Linux available out there. Linux distributions are built on the same reliable core but each one adds different bells and whistles — some distros (as they're known) are for general home, school, or business use. Others specialize: there are editions for Linux newbies and computer security experts; Christians and Muslims ; language versions in Vietnamese and Bulgarian and Farsi, among others; even minimalist versions for old and slow computers. But most users will be interested in the mainstream offerings on the Major Distributions page.
BODNAR: "This lists the 10 most popular Linux distributions with screen shots and little descriptions that tell you what it is and what it's best for. That can help somebody new to Linux decide how to choose their distribution."
And one of the great things about Linux is that many distributions come in the form of a live CD, which boots up on your computer without affecting anything on your hard drive, so you can do a no-risk test.
Ladislav Bodnar says DistroWatch gets more than 100,000 visitors a day. Others keep up with the Linux world by subscribing to the various RSS news feeds or by listening to the podcast.
PODCAST: "Hello and welcome to this week's episode of the DistroWatch weekly podcast. In this week's episode, the Linux package management cheat sheet, part two, new warnings over the e1000e network module ..."
News and information about the vast array of Linux distributions at DistroWatch.com, or get the link to this and more than 200 other Websites of the Week from our site, voanews.com/ourworld.
MUSIC: Lionel Hampton — "Lullaby of Birdland"
It's VOA's science and technology magazine, Our World. I'm Art Chimes in Washington.
Dressing up birds increases appeal to mates
And finally today ...
You know, in a lot of ways, what goes on in human society is a lot like what happens in the animal kingdom.
When we look for a mate, we often are attracted by external features — smooth skin, perhaps, or a certain hair style or body type.
That's one reason why clothes and cosmetics are such big business. Now, a team of scientists in the foothills of the Rocky Mountains have in effect done cosmetic surgery on a bird called the barn swallow and as a result improved its mating success. Shelley Schlender reports.
SCHLENDER: Barn swallows fly into a horse barn near Boulder, Colorado, carrying insects for their hatchlings, who wait in nests made from pellets of mud. With their swooping flight and dark blue plumage, swallows are elegant birds. The males are especially striking, thanks to long tail streamers and a brownish orange chest. But according to biologist Rebecca Safran, those average looks won't guarantee a mate.
SAFRAN: "Females really have the upper hand in the mating game. Males are kind of a dime a dozen, and females are really holding their cards close to their chest."
SCHLENDER: To find out how much appearance appeals to the lady birds, Safran and her research team captured male barn swallows. Using colored markers, they darkened the orange chest feathers on some of them. They also collected a tiny drop of blood to identify each male's DNA and track his hormone levels. In addition, they got DNA from baby swallows. In this way, they discovered that the males whose chest feathers had been enhanced fathered more young.
SAFRAN: "When we manipulate a male's color to look darker, he does better, he attracts more mates. He has more offspring. This is the currency of evolution. Having a number of babies."
SCHLENDER: Those males also had higher levels of the male sex hormone, testosterone.
SAFRAN: "The surprising finding is that simply by changing the male's appearance, his physiology also changed."
SCHLENDER: The darker orange chest feathers seem to attract more females. Safran and her students speculate that these successful interactions may be what raise the birds' testosterone levels. She says that her study is the first to document that changing the outward appearance of an animal can change its inner chemistry.
Research assistant Connor Fitzhugh says the need to attract a mate is a big reason for the dramatic tail feathers on male peacocks, and a lion's magnificent mane — especially when it's a darker orange.
FITZHUGH: "This whole notion that the clothes make the man, it's repeated throughout the animal kingdom. It's not unique to barn swallows."
SCHLENDER: In the wild, those looks are often a sign of fitness, since only a male in good health can produce strong antlers, furry ruffs, or extra colorful feathers.
Another team member, PhD candidate Matt Wilkins, says that when females like what they see, they're probably judging with some accuracy a male's ability to father babies, feed them and defend the roost.
WILKINS: "So, it makes sense. It's kind of an honest signal of quality in a good male."
SCHLENDER: Wilkins adds that the signal varies depending on the male's environment.
WILKINS: "In North America, the males who have more young have darker feathers. That's in comparison to in Europe where the males on average are lighter and have longer tail stringers because there, females don't care so much about the breast color but they prefer males with longer streamers, so that's driving the difference in the species across the globe."
SCHLENDER: Those differences might be caused by subtle variations that determine swallow health in Europe and North America. It's an example, according to Rebecca Safran, of how species change over time. And her research is showing how much female choices about male looks can be part of the change.
SAFRAN: "What we believe is happening is that we're able to record evolution in action. That is, we're studying the formation of new species as they're evolving."
SCHLENDER: But while the researchers have learned a great deal by enhancing the feather color of male barn swallows, they don't recommend this subterfuge as a successful path of evolution. While their doctored males did father more young, they also lost weight, and this may indicate they had to work too hard in order to keep up with their new appearance. After all, unlike a male with naturally darker orange feathers, these counterfeits didn't get their better looks because they were actually healthier. In a horse barn near Boulder, Colorado, I'm Shelley Schlender.
Rebecca Safran's research on barn swallows was published earlier this year in the journal Current Biology. And thanks to the University of Colorado at Boulder for providing audio and video material for this segment.
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That's our show for this week. If you'd like to get in touch, email us at firstname.lastname@example.org. Or use the postal address —
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Rob Sivak edited the show. Eva Nenicka and Bob Doughty are the technical directors.
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.