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Our World — 11 August 2007

MUSIC: "Our World" theme

Straight ahead on "Our World" ... A look at America's aging infrastructure ... the re-awakening of frozen ancient microbes ... and crime-solving by the numbers:

DEVLIN: "This police officer, this mathematician police officer, was able to formulate an equation where you plug in the locations of crimes and it comes up with a hot zone map, a contour map if you like, which shows where the criminal is most likely to live.

Those stories, a student competition to build a solar house, and more. I'm Art Chimes. Welcome to VOA's science and technology magazine, "Our World."

Investigators this week say they found what may be a design flaw in the 40-year-old Minneapolis highway bridge that suddenly collapsed and fell into the Mississippi River on August 1.

The National Transportation Safety Board is looking at a possible problem with the gusset plates. Those are large pieces of steel that tied together the steel trusses that supported the bridge.

Even before the government investigators raised this particular design issue, others wondered about the engineering decisions that were made when the bridge was designed, 40 years ago.

Civil engineering professor Jerry Hajjar at the University of Illinois says the Minneapolis bridge might not have been designed as robustly as structures built before or since.

HAJJAR: "I do think they had had a good run of designing of bridges for a number of years after World War II and that their confidence had been increasing. I think certainly they felt that they were being safe in their designs, and in many ways they were, but it's true that we have learned a lot since then."

The bridge collapse focused international attention in a particularly dramatic way on the general state of infrastructure maintenance in America. The Minneapolis bridge is one of tens of thousands across the country classified as "structurally deficient" — not in imminent danger of collapse, necessarily, but needing attention.

Congressman James Oberstar, a Minnesota Democrat who chairs the House Transportation Committee, illustrated the extent of the problem by describing the status of the bridges in just one state.

OBERSTAR: "In Minnesota we have 12,989 bridges; 1,140 — roughly 12 percent — are considered structurally deficient; and 446 are considered functionally obsolete, and they need to be upgraded."

And it's not just bridges, but also highways, pipelines, tunnels, power transmission, railroads, and so on. The American Society of Civil Engineers periodically rates the overall condition of these essential engineering fixtures. Deputy executive director Larry Roth says most of America's infrastructure is barely adequate.

ROTH: "We believe our infrastructure is in crisis, and in this crisis mode it works against our prosperity and it works also against our health. And unfortunately, if we don't pay attention to it, time is working against us and the infrastructure will continue to crumble, and just will not be able to support a healthy economy."

Inspecting and maintaining bridges — or dams, water systems, or transit systems — is not very sexy stuff and Jerry Hajjar, the University of Illinois professor, says getting the needed funding is a problem.

HAJJAR: "Politicians in general are supportive and understand it, but it's difficult to fund it at the level that I think a very broad range of the engineering community thinks is important."

Money is not necessarily the only important factor. Other countries, less prosperous than America, may in fact be doing a better job. In an international study, the Washington-based Urban Land Institute this year looked how a number of nations deal with their infrastructure issues. According to senior resident fellow Bob Dunphy, good infrastructure policies require political leadership, not just money.

DUNPHY: "Many of them are handling it well without the resources, and I think that was a surprising answer. And we've seen some good models in Europe, and of course most of those are relatively wealthy countries worldwide. But surprising even in some of the other countries, particularly in Asia, China and Asia are doing very well in their infrastructure investments. These are relatively poor countries."

The study noted that China, for example, is a country where many senior officials have a background in engineering. Also, sometimes it's easier to get things done in a command economy than in a messy democracy.

Politicians who manage to find the money for new bridges often get their name put on the span. That just doesn't happen if all you find is the money to maintain the bridge you've already got. But as Akron, Ohio, Mayor Donald Plusquellic said in 2004, "I would rather replace a bridge a day too soon than a day too late."

Scientists say they have been able to coax back to life bacteria frozen in Antarctic ice for 100,000 years or more.

The work by Dr. Kay Bidle of Rutgers University and colleagues was done in the laboratory, but as temperatures rise and glaciers melt, microorganisms and other bits of DNA could return to the environment.

The researchers had ice samples ranging from 100,000 years old to 8 million years old, but there was a significant difference in what they found, depending on how long ago the ice had formed.

The organisms that did grow did so at much slower rates. We also showed that in the old ice there is significant deterioration of the genetic material due to cosmic radiation exposure over such long geological times."

Our Earth has cycled through warm and cold periods over the course of millions of years. If the current warming cycle is releasing microorganisms trapped in ice from the ancient past, has this also happened in the past, and does it stimulate the pace of evolution?

BIDLE: "That's a great question, and that's something that is one of our driving hypotheses: when you've had melting events like this, that they were mechanisms by which the tempo of evolution would increase substantially. And we see that in the fossil record, that when you have these cycles you do see diversification. Whether we'll be able to detect that is another question. I think it's yet to be determined."

Bidle, a marine and coastal sciences professor at Rutgers University in New Jersey, says that as glaciers melt, water containing these ancient microbes — or bits of their DNA — will flow into the oceans where it will intermingle with the genomes of existing micro-organisms in a process called "lateral gene transfer." But he says the mixing of ancient and contemporary DNA is unlikely to pose a threat.

BIDLE: "Now there is a possibility that some organisms that are encased in different types of ice might represent potential pathogens to animals — not necessarily humans — and then once the glaciers melt they can be reintroduced. But, you know, I think that possibility is probably extremely, extremely rare."

Kay Bidle of Rutgers University. His study was published this week in the online edition of the Proceedings of the National Academy of Sciences.

Have you had your fruits and vegetables today? There are lots of reasons to eat a variety of these healthy foods. And according to some new research, one reason is that some fruits and vegetables — those rich in antioxidants — may help reverse some of the effects of aging. Our health reporter, Rose Hoban, has the details.

HOBAN: Scientists are only now beginning to understand the role of chemical ions called free radicals circulating in the body. They are a by-product of the body's normal activity. They have an extra electron and this electrical charge makes them want to attach to something. Usually, free radicals end up binding with cell membranes, or parts of cells, thus damaging them. Researchers say that ages the cell.

Dr. Jim Joseph from the US Department of Agriculture lab in Massachusetts says that antioxidant chemicals can prevent that damage.

JOSEPH: "And your body makes a certain amount of antioxidant. And so these are normally able to protect the cell. Now what happens though, if a hit gets through, is you need something to clean things up. You need something to fix it. And so you have things like the ability to repair DNA. And so this is what antioxidants do whenever free radicals impinge on them."

HOBAN: Joseph and his colleagues at the USDA lab studied aging rats that were fed a regular diet. They compared them to rats that ate foods high in antioxidants.

JOSEPH: "And what we found was that they were able to perform much better on these motor and cognitive tasks than the animals who didn't get the diet."

HOBAN: Joseph says the antioxidants in the smart rats' diets came from fruits and vegetables…

JOSEPH: "...such as blueberries, strawberries, spinach, walnuts, avocados, pomegranates. And the one characteristic you note that all of these have is the colors. So if you need a guide, go by the dark intense colors. But don't forget white, because garlic and cauliflower are also high in antioxidants, they're just a little different variety."

HOBAN: Joseph says people, like rats, lose cognitive ability as they age. He says these same benefits of antioxidants in fruits and vegetables could be translated to humans.

JOSEPH: "We didn't make them young again, but we made them better. We're not working miracles here, we're just helping out a little bit."

HOBAN: Joseph's research is published in the journal, Neurobiology of Aging. I'm Rose Hoban.

You can also read about the research in the U.S. Department of Agriculture's magazine, Agricultural Research, online at

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

This time it's a global collection of health and medical statistics that provides accurate and timely information, and where the emphasis is on ease of use:

KATES: "Our site provides two things. One is, easy-to-access information on these key indicators, and the second is a whole range of indicators. We've gone out there to other sites and pulled in what we see as really important health and socioeconomic indicators, and we can grow the site over time."

Jen Kates is director of HIV Policy at the Kaiser Family Foundation, which publishes health information websites, including

The site offers some key health and demographic indicators, including numbers of AIDS orphans, tuberculosis treatment success with DOTS therapy, household size and population under age 15. You can see the numbers, or better yet, visualize them on color-coded maps. You can also download the data if you want to do your own analyses. And soon, says Jen Kates, there will be a feature on the site that will enable visitors to create custom, ready-to-print reports.

KATES: "We're actually always trying to think about what users might need. And the next thing that we're going to be pushing out is a custom dataset, so you can kind of say, well I want to look at this, this and this for these four countries, and you can actually get that into a PDF."

The site's homepage features a constant stream of international health news, and you can subscribe to a variety of free email newsletters on subjects including children's health and HIV.

I've seen a lot of websites with these kinds of health data, but I don't think I've ever seen one more user-friendly than this. Check it out at GlobalHealthFacts — all one word —, or get the link from our site,

MUSIC: "Young and Healthy" (from the 1933 movie, 42nd Street)

Keeping you young and healthy, we're VOA's science and technology magazine, Our World. I'm Art Chimes in Washington.

In mid-October, university students from across the United States will come to Washington to compete in an event called the Solar Decathlon. They'll be showing off solar houses they designed and built, then had trucked to the National Mall. But it takes a lot to design and build those houses, as VOA's Rosanne Skirble found when she visited the University of Maryland team.

SKIRBLE: On a grassy lot in the shade of the University of Maryland School of Architecture, a new house is under construction.

Students supply the labor and manage the worksite.

KUCIA: "This is the front door of the house. Welcome to the Leaf House. We are still under construction."

TEXT: Our guide is team leader John Kucia a third year architecture student. Kucia joined the 'Leaf House' project about a year ago in a design class. Since then 250 students, faculty members and mentors from the commercial building trades have worked on the house's many solar-powered systems.

KUCIA: "One of the first things that you notice when you walk in — and it's great that you guys are here because no one is going to be able to see this for the competition — we have a radiant flooring system. We are essentially pumping hot water that is being collected from the roof of the house. We have a special panel that converts sunlight into heat into a fluid. We pump the fluid around the floor and it heats the house."

SKIRBLE: The solar panels are not yet in place. Kucia motions toward the roof where they will be installed. He explains that the array will supply enough energy to heat and cool the house, power its lights and run all its integrated operations.

KUCIA: "We have a smart house system in the works. The smart house computer system will be examining all the mechanical and electrical components as well as windows and doors, the interior and exterior environment regulating the systems of the house."

SKIRBLE: Meaning that lights can be dimmed or air conditioning turned off remotely over the Internet.

Mechanical engineering student Tyler Sines says the cooling system — which he helped design — gives the team a competitive advantage. It uses the liquid form of a material commonly found in the tiny packets enclosed with new shoes to keep the footwear moisture-free. He says this is the first time a desiccant, as it's called, has been applied to a home cooling system to suck humidity out of the air.

A homeowner can actually view the cascading desiccant from a showcase built into the wall. Sines says the waterfall-like feature serves both an aesthetic and practical purpose.

SINES: "You will really see the humidity coming out of the house. You'll see the desiccant being sprayed down. And we will shoot up an air stream to take away all the moisture."

SKIRBLE: Walking outside, team leader John Kucia explains how part of a south-facing wall will help conserve water and reduce erosion of the soil surrounding the house.

KUCIA: "The best way to explain it is we are putting a bunch of planters up on the wall and when it is fully grown you are going to have a solid wall of nothing but greenery. The gutter systems of our roof will be watering this vertical plant system."

TEXT: Reflecting the same efficiency of the Leaf House's integrated systems, the student team that designed and built the house works well together, says architecture graduate student Brittany Williams.

WILLIAMS: "We really want to change the way the profession works and allow architects and engineers to work together constantly. It actually makes a more beautiful home as well as one that is more efficient."

SKIRBLE: The University of Maryland 'Leaf House' will be trucked in mid-October from its College Park, Maryland, campus to the National Mall in nearby Washington, D.C. There, it will take its place among 20 collegiate entries being judged in the U.S. Department of Energy-sponsored Solar Decathlon. I'm Rosanne Skirble.

You probably studied math in school at some point. And you probably wondered, will this stuff ever be useful in real life? Mathematicians Keith Devlin and Gary Lorden answer an emphatic "Yes!" In their new book, "The Numbers Behind Numb3rs," they use examples from a popular TV show and from real life to argue that math is especially useful in the science of crime-solving, as Adriana Salerno reports.

SALERNO: The premise of Numb3rs, a CBS-TV series that premiered in 2005, is simple: two brothers, one a seasoned cop, the other a genius mathematician, team up to solve crimes in modern-day Los Angeles. Keith Devlin, a professor of mathematics at Stanford University, was immediately attracted to this idea, and not just because the hero is a mathematician.

DEVLIN: "The interesting thing about this is that it's about two different methods of problem solving, interactions, you know. You've got Don Eppes, who uses street-smart logic, he has everyday common sense logic, and he uses that in approaching a crime. His brother Charlie has the opposite kind of logic, as far away as possible: it's abstract, esoteric, pure mathematical logic. And in the show, as in real life, when you put together those two different approaches to solving problems, boy, do you have a powerful combination."

SALERNO: Devlin and co-author Gary Lorden, who is also the main math consultant for the show, decided to write a book that was very close to the series in its way of talking about mathematics, but that takes the reader a little deeper into the subject.

DEVLIN: "What we do is describe the mathematics in more detail than you can get on the TV show, but it's not a mathematics textbook, and it doesn't teach you how to do it, it just describes and explains how it works.

SALERNO: Devlin says that they wanted to provide examples of how law enforcement agencies use mathematics to solve real-life crimes, not just those featured in the TV show.

In one episode, an equation is used to find a serial killer based on where his crimes were committed.

DEVLIN: "That was based on a real case, in Lafayette, Louisiana. What it boiled down to was this police officer called Kim Rossmo, this mathematician police officer, was able to formulate an equation where you plug in the locations of crimes and it comes up with a hot zone map, a contour map, if you like, that shows where the criminal is most likely to live. That's a technique that really works and yet I'm intrigued because it's an interesting mixture of, again, two kinds of thinking.

SALERNO: Devlin explains how mathematics can also be an effective tool for predicting criminal behavior.

DEVLIN: "We may think we are free agents but we follow far more predictable patterns than what we are aware of, and mathematics can on occasion uncover those patterns."

SALERNO: Devlin says that single criminal acts are much more difficult to solve using mathematics, since there's no pattern yet to the criminal's behavior. He says one especially useful tool in these cases is image enhancement, which uses sophisticated mathematical techniques.

DEVLIN: "You can take very blurry images taken from surveillance cameras, or people's films that they're making on their mobile phones or sometimes newsreel film shot from a helicopter, and you can take an image where you would think it would be impossible to identify a person, and yet using very sophisticated mathematical techniques you can enhance that image so not only can you recognize that person but you can see details like tattoos on people's arms, and scars on their legs and so forth.

SALERNO: Devlin concedes that while the mathematics in the show is very real, the series does take a few liberties. He admits that one person probably couldn't solve a criminal case so quickly, and wouldn't have the expertise in so many branches of math.

DEVLIN: "Mathematics has exploded so much through the late 19th century and throughout the 20th century and now into the 21st century, we know only a small fraction and can keep up with only a small fraction of it, it's just huge and it's growing all the time. We have to accept that Charlie is a television superhero, he's an iconic representation of all the mathematicians out there who consult for the FBI and for the law enforcement agencies. So he encapsulates the whole of the mathematical community and personifies it."

SALERNO: Keith Devlin and co-author Gary Lorden, hope "The Numbers Behind Numb3rs" will help readers to understand that crime-solving and mathematics are not that far apart: it's all about finding patterns, solving puzzles, pinpointing the crucial elements in a problem and determining the best strategies to solve it. The book will be published August 28 by Plume Paperbacks. I'm Adriana Salerno.

We have to say goodbye to Adriana Salerno, who leaves us to go back to school. In real life, Adriana teaches mathematics at the University of Texas, where she is also working on her PhD. She has spent the last couple of months at VOA, in the Media Fellowship program of the American Association for the Advancement of Science. We are going to miss her enthusiasm, her sense of humor, her willingness to try new things, and her ability to make math stories, of all things, into great radio stories.

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 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 or on your radio next Saturday and Sunday as we check out the latest in science and technology ... in Our World.