What would happen if solar panels were free? What if it were possible to know everything about the world—not the Internet, but the living, physical world—in real time? What if doctors could forecast a disease years before it strikes? This is the promise of the World Changing Idea: a vision so simple yet so ambitious that its full impact is impossible to predict. Scientific American’s editorial and advisory boards have chosen projects in five general categories—Energy, Transportation, Environment, Electronics and Robotics, and Health and Medicine—that highlight the power of science and technology to improve the world. Some are in use now; others are emerging from the lab. But all of them show that innovation is the most promising elixir for what ails us. —The Editors
The No-Money-Down Solar Plan
A new wave of start-ups wants to install rooftop solar panels on your house. Upfront cost: nothing
By Christopher Mims
The biggest thing stopping the sun is money. Installing a rooftop array of solar panels large enough to produce all of the energy required by a building is the equivalent of prepaying its electricity bill for the next seven to 10 years—and that’s after federal and state incentives. A new innovation in financing, however, has opened up an additional possibility for homeowners who want to reduce their carbon footprint and lower their electric bills: get the panels for free, then pay for the power as you go.
The system works something like a home mortgage. Organizations and individuals looking for a steady return on their investment, typically banks or municipal bond holders, use a pool of cash to pay for the solar panels. Directly or indirectly, homeowners buy the electricity produced by their own rooftop at a rate that is less, per kilowatt-hour, than they would pay for electricity from the grid. Investors get a safe investment—the latest generation of solar-panel technology works dependably for years—and homeowners get a break on their monthly bills, not to mention the satisfaction of significantly reducing their carbon footprint. “This is a way to get solar without putting any money down and to start saving money from day one. That’s a first,” says SolarCity co-founder Peter Rive.
SolarCity is the largest installer of household solar panels to have adopted this strategy. Founded in 2006 by two brothers who are also Silicon Valley–based serial entrepreneurs, SolarCity leases its panels to homeowners but gives the electricity away for free. The net effect is a much reduced utility bill (customers still need utility-delivered power when the sun isn’t out) plus a monthly SolarCity bill. The total for both comes out to less than the old bill. SunRun in San Francisco offers consumers a similar package, except that the company sells customers the electricity instead of leasing them the panels.
Cities such as Berkeley and Boulder are pioneering their own version of solar-panel financing by loaning individuals the entire amount required to pay for solar panels and installation. The project is paid for by municipal bonds, and the homeowner pays back the loan over 20 years as a part of the property tax bill. The effect is the same whichever route a consumer takes: the new obligation, in the form of taxes, a lease or a long-term contract for electricity, ends up costing less than the existing utility bill.
“What we’re really seeing is a transition in how we think about buying energy goods and services,” says Daniel M. Kammen, director of the Renewable and Appropriate Energy Laboratory at the University of California, Berkeley. Kammen, who did the initial analysis on Berkeley’s financing model, believes that by turning to financing, consumers can overcome the inherent disadvantage renewables have when compared with existing energy sources: the infrastructure for power from the grid has already been paid for and, in many cases, has been subsidized for decades.
All three approaches are rapidly expanding across the country. Despite the Berkeley program being less than two years old, 10 different states have passed legislation allowing their cities to set up a Berkeley-style bond-financed loan program. With the passage of the Waxman-Markey climate bill, the option for cities to set up these programs would become federal law. SunEdison in Maryland is currently active in nine states. SolarCity, which has more than 4,000 customers, is active in California, Arizona and Oregon and has promised to announce additional states after the new year.
Right now it is not possible to lower the overall cost of rooftop solar to “grid parity,” that is, to the same price as electricity from local utility companies, without federal subsidies such as the investment tax credit, which lowers the tax bill of banks financing these projects. Those subsidies, which amount to 30 percent of the cost of a solar installation, are guaranteed for at least eight years. By then, SolarCity and its competitors claim they won’t need them.
“Grid parity is driven by multiple factors,” says Attila Toth, vice president of marketing at SunEdison, including the cost of capital, the cost of panels and their installation, and the intensity of sunlight in a given region. “It will occur in different states at different times, but, for example, we expect that California will be one of the first states in the U.S. to get to grid parity, sometime between three and five years from now.”
While the cost of electricity from fossil fuels has increased 3 to 5 percent a year for the past decade, the cost of solar panels has fallen on average 20 percent for every doubling of its installed base. Grid parity is where these trend lines cross—after that, solar has the potential to power more than just homes. It’s hardly a coincidence that Elon Musk, head of electric car company Tesla Motors, sits on SolarCity’s board of directors.
More Ideas to watch
by Christopher Mims
The Gasoline Garden
It is the next step for biofuels: genetically engineered plant life that produces hydrocarbons as a by-product of its normal metabolism. The result will be fuel—common gasoline, even—using nothing but sunlight and CO2. In July, Exxon Mobil announced plans to spend more than $600 million in pursuit of algae that can accomplish the task. Joule Biotechnologies claims to have already succeeded, although the company has yet to reveal any details of its proprietary system.
Uranium and plutonium are not the only fuels that can power a nuclear reactor. With an initial kick from more traditional fissile materials, thorium can set up a self-sustaining “breeder” reaction that produces uranium 233, which is well suited to nuclear power generation. The process has the added benefit of being resistant to nuclear proliferation, because its end products emit enough gamma rays to make the fuel dangerous to handle and easy to track.
Save Energy with Information
Studies show that simply making customers aware of their energy use lowers it
by 5 to 15 percent. Smart meters allow customers to track their energy consumption minute by minute and appliance by appliance. Countless start-ups are offering the devices, and Google and Microsoft are independently partnering with local utilities to allow individuals to monitor their power usage over the Web.
Wind Power from the Stratosphere
According to a Stanford University study released in July, the high-altitude winds that constantly blow tens of thousands of feet above the earth hold enough energy to supply all of human civilization 100 times over. California’s Sky WindPower has proposed harvesting this energy by building fleets of giant, airborne, ground-tethered windmills, while Italy’s Kite Gen proposes to accomplish the same feat using kites.
Delivering the U.S. from Oil
Plug-in hybrid trucks are improving the long view of the short haul
By Amanda Schupak
Cargo trucks gulp about 40 percent of the fuel pumped in the U.S. While most consumer attention focuses on improving the fuel economy of consumer vehicles, a major opportunity goes rumbling by. “Folks do not realize that the fuel use of even a small truck is equal to many, many cars,” says Bill Van Amburg, senior vice president of Calstart, a clean transportation technology nonprofit, and director of the Hybrid Truck Users Forum. “A utility truck as a hybrid would reduce more petroleum than nine Priuses.”
Some 1,300 commercial hybrids on the road today get up to twice the fuel efficiency of their conventional counterparts. But these traditional hybrids are inherently limited. They make more efficient use of petroleum-based fuel by capturing some of the energy lost during braking.
Plug-in hybrids, on the other hand, draw energy from the grid. They can drive for miles—in many cases, an entire day’s route—without using any fossil fuel at all. This shifts energy demand away from petroleum and toward grid-based sources. (Last year zero-carbon renewables and nuclear supplied 30 percent of all electric power in the U.S.)
In many ways, plug-in hybrid technology makes more sense for delivery trucks than for consumer sedans. A cargo truck runs a short daily route that includes many stops to aid in regenerative braking. Most of the U.S. Postal Service’s 200,000-plus mail trucks, for example, travel fewer than 20 miles a day. In addition, fleet vehicles return nightly to storage lots that have ready access to the 120- or 240-volt outlets required to charge them.
The Department of Energy recently launched the nation’s largest commercial plug-in hybrid program, a $45.4-million project to get 378 medium-duty vehicles on the road in early 2011. The trucks, which will go to 50 municipal and utility fleets, will feature a power system from Eaton, a large manufacturer of electrical components, on a Ford F-550 chassis. (For its part, Ford will wait for the market to prove itself before designing its own commercial plug-ins.) “These are going to start breaking free in 2011,” says Paul Scott, president of the Electric Vehicle Association of Southern California.
Start-up company Bright Automotive has a more ambitious plan. It aims to replace at least 50,000 trucks with plug-in hybrids by 2014. Bright’s IDEA prototype travels 40 miles on battery power before switching to a four-cylinder engine that gets 40 miles to the gallon. The streamlined aluminum body has the payload of a postal truck yet is far more aerodynamic. The truck weighs as much as a midsize sedan.
John E. Waters, Bright Automotive’s founder and the former developer of the battery system for General Motors’s groundbreaking EV1 electric car, says that each IDEA would save 1,500 gallons of fuel and 16 tons of carbon dioxide emissions a year over a standard utility truck. Waters says he is ready to begin assembly in his U.S. plant once a pending $450-million federal loan comes through.
Despite the appeal of the carbon savings, the fleet owners who are the trucks’ primary customers have more practical considerations. Bright’s executives are coy about the IDEA’s eventual price tag but assert that a customer with 2,000 trucks driving 80 miles a day five days a week could save $7.2 million a year. Right now that is probably not enough to justify large-scale purchases without additional rebates—or a price on carbon. Van Amburg estimates that going hybrid currently adds $30,000 to $50,000 in upfront costs per vehicle, although that figure should come down as production volumes increase.
Improved battery technology will also help. Today the IDEA’s 13-kilowatt-hour lithium-ion battery pack accounts for nearly a quarter of the vehicle’s total cost. Much of the research being done for the batteries going into the Chevy Volt and other consumer plug-ins should also be applicable to commercial batteries. “For all the good we all want to do,” says David Lauzun, Bright’s vice president of product development, “these vehicles will not take over the world until it becomes the economic choice—‘I have to have them because it saves me money.’”
Bus Rapid Transit
Subwaylike bus lines mobilize the urban future
By Michael Moyer
For the first time in human civilization, more people now live in urban areas than in the countryside. This shift creates a number of dilemmas, not least of which is how to move people within the world’s rapidly growing metropolises. Pollution and traffic point away from car-based options, while light-rail systems are slow to construct and prohibitively expensive. One disarmingly simple—and cheap—possibility is Bus Rapid Transit, which is engineered to operate like a subway on wheels. In these systems, concrete dividers on existing roads separate high-capacity buses from the rest of traffic. Riders pay before boarding, then wait in enclosed stations. When a bus arrives, sliding partitions open to allow riders to board from a platform that is level with the bus floor. The traffic-free thoroughfares, quick boarding times, and modern, comfortable stations resemble light-rail systems more than the chaos of typical bus travel. In Bogotá, Colombia, which has had seven Bus Rapid Transit lines in operation since 2001, the buses handle 1.6 million trips a day. Its success has allowed the city to remove 7,000 private buses from the city, reducing consumption of bus fuel and its associated pollution by more than 59 percent.
Marine zoning is a bold remedy for sick seas
By Sarah Simpson
These days not even many politicians deny that the oceans are ill. Protecting the health of coastal waters is now a matter of national policy in dozens of countries, including the U.S., and world leaders are beginning to prescribe a revolutionary remedy that conservationists have been promoting for years: marine planning and zoning.
The idea is a natural extension of management policies that have guided the development of cities and landscapes for nearly a century. Porn shops aren’t next to preschools, after all, and drilling rigs aren’t the centerpieces of national parks. Similarly, zoning advocates envision a mosaic of regional maps in which every watery space on the planet is designated for a particular purpose. Drilling and mining would be allowed only in certain parts of the ocean; fishing in others. The most critically threatened areas would be virtually off-limits.
Whereas people can easily find maps telling them what they can do where on land, the marine realm is a hodgepodge of rules emanating from an army of agencies, each one managing a single use or symptom. In the U.S., for example, one body regulates commercial fishing, usually a single species at a time. Another group manages toxic substances, still another seabed mining, and so on—some 20 federal agencies in all. They tend to make decisions without regard to what the others are doing, explains Duke University marine ecologist Larry B. Crowder. “Imagine all of the medical specialists visiting a patient in intensive care one at a time and never talking to one another,” he says. “It’s a wonder that the oceans aren’t in worse shape than they are now.”
Ocean advocates such as Crowder eagerly await the final recommendations of a special task force President Barack Obama charged with presenting a plan for overhauling management of U.S. waters, which extend 200 nautical miles offshore. The scope of such an undertaking is huge: the U.S. controls 4.4 million square miles of seascape, making the country’s underwater real estate 25 percent larger than its landmass. The committee’s preliminary report, released in September, suggests that the best way to minimize harmful human impacts on the oceans is to manage regions rather than symptoms.
Many environmentalists are hopeful that such plans will be implemented through the marine equivalent of municipal zoning, which would give them some influence in areas where they now have none. In zones where conservation is designated as the dominant activity, fishing and industrial activities such as mining would no longer have free rein. Under current rules, about the only way a conservation group can block a project it deems harmful—say, a new site for offshore drilling—is through expensive litigation.
So far, though, the president’s task force has been careful not to suggest that ocean zoning will be the only treatment plan, in great part because any effort to restrict commercial interests is bound to meet stiff opposition. “Zoning isn’t anybody’s favorite exercise,” notes John C. Ogden, director of the Florida Institute of Oceanography at the University of South Florida at Tampa. “Someone’s ox is always getting gored.” Most resistant to such change will most likely be the traditional users of the open ocean—namely, commercial fisheries and the petroleum industry. “They’ve had the place to themselves for a long time,” Ogden says.
Ogden and others are quick to point out, however, that zoning practices can benefit commerce as much as conservation. By giving up access to certain areas, industries gain the security of knowing their activities would be licensed in a more predictable and less costly manner than they are today, explains Josh Eagle, associate professor at the University of South Carolina School of Law. Now an oil company can apply for permits to drill virtually anywhere, but it takes on a significant financial risk each time. The business may dump millions of dollars into researching a new facility only to have a lawsuit derail it at the last moment. When opposing parties have more or less equal voices early in the planning process, Eagle says, they are less inclined to block one another’s activities once zones are drawn on a map.
Whether the final report of the president’s task force will promote ocean zoning explicitly is uncertain. But the group has already promised to overhaul the structure of ocean governance by proposing the creation of a National Ocean Council, whose job it will be to coordinate efforts of the myriad federal agencies now in charge.
The move comes just in time. Just as society is beginning to appreciate the enormous efforts it will take to preserve the health of the oceans, it must ask more of them—more energy, more food, and better resilience to coastal development and climate change. The reason the oceans are in trouble is not what people put in and take out. It is a failure of governments to manage these activities properly. Says Crowder: “We have to treat the oceans holistically, not one symptom at a time.”
The Power of Garbage
Trapped lightning could help zap trash and generate electricity
By John Pavlus
Trash is loaded with the energy trapped in its chemical bonds. Plasma gasification, a technology that has been in development for decades, could finally be ready to extract it.
In theory, the process is simple. Torches pass an electric current through a gas (often ordinary air) in a chamber to create a superheated plasma—an ionized gas with a temperature upward of 7,000 degrees Celsius, hotter than the surface of the sun. When this occurs naturally we call it lightning, and plasma gasification is literally lightning in a bottle: the plasma’s tremendous heat dissociates the molecular bonds of any garbage placed inside the chamber, converting organic compounds into syngas (a combination of carbon monoxide and hydrogen) and trapping everything else in an inert vitreous solid called slag. The syngas can be used as fuel in a turbine to generate electricity. It can also be used to create ethanol, methanol and biodiesel. The slag can be processed into materials suitable for use in construction.
In practice, the gasification idea has been unable to compete economically with traditional municipal waste processing. But the maturing technology has been coming down in cost, while energy prices have been on the rise. Now “the curves are finally crossing—it’s becoming cheaper to take the trash to a plasma plant than it is to dump it in a landfill,” says Louis Circeo, director of Plasma Research at the Georgia Tech Research Institute. Earlier this summer garbage-disposal giant Waste Management partnered with InEnTec, an Oregon-based start-up, to begin commercializing the latter’s plasma-gasification processes. And major pilot plants capable of processing 1,000 daily tons of trash or more are under development in Florida, Louisiana and California.
Plasma isn’t perfect. The toxic heavy metals sequestered in slag pass the Environmental Protection Agency’s leachability standards (and have been used in construction for years in Japan and France) but still give pause to communities considering building the plants. And although syngas-generated electricity has an undeniably smaller carbon footprint than coal—“For every ton of trash you process with plasma, you reduce the amount of CO2 going into the atmosphere by about two tons,” Circeo says—it is still a net contributor of greenhouse gases.
“It is too good to be true,” Circeo admits, “but the EPA has estimated that if all the municipal solid waste in the U.S. were processed with plasma to make electricity, we could produce between 5 and 8 percent of our total electrical needs—equivalent to about 25 nuclear power plants or all of our current hydropower output.” With the U.S. expected to generate a million tons of garbage every day by 2020, using plasma to reclaim some of that energy could be too important to pass up.
More Ideas to watch
By John Pavlus
Cement as a Carbon Sponge
Traditional cement production creates at least 5 percent of global carbon dioxide emissions, but new materials could create carbon-neutral cement. Start-up Novacem, supported by Imperial College London, uses magnesium oxide to make cement that naturally absorbs CO2 as it hardens. California-based Calera uses seawater to sequester carbon emissions from a nearby power plant in cement.
The New Honeybee
Colony collapse disorder (CCD) has killed more than a third of honeybee colonies since 2006. Farmers who depend on bees to pollinate such crops as almonds, peaches and apples are looking to the blue orchard bee to pick up the slack.
One efficient Osmia lignaria can pollinate as much territory as 50 honeybees, but the bees are harder to cultivate because of their solitary nature. These pinch hitters won’t completely replace honeybees, but as scientists continue to grapple with CCD, they could act as an agricultural safety net.
As the world’s freshwater supply becomes scarcer and food production needs balloon, salt-tolerant crops could ease the burden. Researchers at Australia’s University of Adelaide used genetic engineering to enhance a model crop’s natural ability to prevent saline buildup in its leaves, allowing the plant to thrive in conditions that would typically wither it. If the same gene tweak works in cereal crops such as rice and wheat—the researchers are testing them now—fallow lands destroyed by drought or overirrigation could become new breadbaskets.
The Omnipotence Machines
Tiny, ubiquitous sensors will allow us to index the physical world the way the Web maps cyberspace
By Gregory Mone
Earlier this year Hewlett-Packard announced the launch of its Central Nervous System for the Earth (CeNSE) project, a 10-year effort to embed up to a trillion pushpin-size sensors across the planet. Technologists say that the information gathered by this kind of ubiquitous sensing network could change our knowledge of the world as profoundly as the Internet has changed business. “People had no idea the Web was coming,” says technology forecaster Paul Saffo. “We are at that moment now with ubiquitous sensing. There is quite an astonishing revolution just around the corner.”
The spread of versatile sensors, or “motes,” and the ability of computers to analyze and either recommend or initiate responses to the data they generate, will not merely enhance our understanding of nature. It could lead to buildings that manage their own energy use, bridges that flag engineers when in need of repair, cars that track traffic patterns and detect potholes, and home security systems that distinguish between the footfalls of an intruder and the dog, to name a few.
CeNSE is the boldest project yet announced, but HP is not the only organization developing the technology to make ubiquitous sensing possible. Intel is also designing novel sensor packages, as are numerous university labs.
For all the momentum in the field, though, this sensor-filled future is by no means inevitable. These devices will need to generate rich, reliable data and be rugged enough to survive tough environments. The sensor packages themselves will be small, but the computing effort required will be enormous. All the information they gather will have to be transmitted, hosted on server farms, and analyzed. Finally, someone is going to have to pay for it all. “There is the fundamental question of economics,” notes computer scientist Deborah Estrin of the University of California, Los Angeles. “Every sensor is a nonzero cost. There is maintenance, power, keeping them calibrated. You don’t just strew them around.”
In fact, HP senior researcher Peter Hartwell acknowledges that for CeNSE to hit its goals, the sensors will need to be nearly free. That is one of the reasons why HP is designing a single, do-everything, pushpin-size package stacked with a variety of gauges—light, temperature, humidity, vibration and strain, among others—instead of a series of devices for different tasks. Hartwell says that focusing on one versatile device will drive up volume, reducing the cost for each unit, but it could also allow HP to serve several clients at once with the same sensors.
Consider his chief engineering project, an ultrasensitive accelerometer. Housed inside a chip, the sensor tracks the motion of a tiny, internal movable platform relative to the rest of the chip. It can measure changes in acceleration 1,000 times as accurately as the technology in the Nintendo Wii.
Hartwell imagines situating one of these pins every 16 feet along a highway. Thanks to the temperature, humidity and light sensors, the motes could serve as mini weather stations. But the accelerometers’ vibration data could also be analyzed to determine traffic conditions—roughly how many cars are moving past and how quickly. The local highway department would be interested in this information, he guesses, but there are potential consumer applications, too. “Your wireless company might want to take that information and tell you how to get to the airport the fastest,” Hartwell says.
All of this gathering and transmission of data requires power, of course, and to guarantee an extended life, the HP pushpin will not rely solely on batteries. “It is going to have some sort of energy-scavenging ability,” Hartwell says. “Maybe a solar panel or a thermoelectric device to help keep the battery charged.”
With the power hurdle in mind, other groups are forgoing batteries altogether. At Intel Labs in Seattle, engineer Josh Smith has developed a sensor package that runs on wireless power. Like the HP pushpin, Intel’s WISP, or Wireless Identification and Sensing Platform, will include a variety of gauges, but it will also draw energy from the radio waves emitted by long-range radio-frequency ID chip readers. Smith says a single reader, plugged into a wall outlet, can already power and communicate with a network of prototype WISPs five to 10 feet away—a distance that should increase.
Smith cites many of the same infrastructure-related possibilities as Hartwell, along with a number of other uses. If WISPs were placed on standard household items such as cups, these tags could inform doctors about the rehabilitation progress of stroke victims. If the cups the patient normally uses remain stationary, Smith explains, then the individual probably is not up and moving around.
The potential applications for ubiquitous sensing are so broad—a physicist recently contacted him about using WISPs to monitor the temperature outside a proposed neutrino detector—that, as with the Internet, Smith says it is impossible to foresee them all. “In terms of the impact it is going to have on our lives,” Hartwell adds, “you haven’t seen anything yet.”
The Do-Anything Robot
Your PC can accomplish any computing task you ask of it. Why isn’t the same true for robots
By Gregory Mone
Robots have proved to be valuable tools for soldiers, surgeons and homeowners hoping to keep the carpet clean. But in each case, they are designed and built specifically for the job. Now there is a movement under way to build multipurpose machines—robots that can navigate changing environments such as offices or living rooms and work with their hands.
All-purpose robots are not, of course, a new vision. “It’s been five or 10 years from happening for about 50 years,” says Eric Berger, co-director of the Personal Robotics Program at Willow Garage, a Silicon Valley start-up. The delay is in part because even simple tasks require a huge set of capabilities. For a robot to fetch a mug, for example, it needs to make sense of data gathered by a variety of sensors—laser scanners identifying potential obstacles, cameras searching for the target, force feedback in the fingers that grasp the mug, and more. Yet Berger and other experts are confident that real progress could be made in the next decade.
The problem, according to Willow Garage, is the lack of a common platform for all that computational effort. Instead of building on the capabilities of a single machine, everyone is designing robots, and the software to control them, from the ground up. To help change this, Willow Garage is currently producing 25 copies of its model PR2 (for “Personal Robot 2”), a two-armed, wheeled machine that can unplug an appliance, open doors and move through a room. Ten of the robots will stay in-house, but 10 more will go to outside research groups, and everyone will pool their advances. This way, Berger says, if you want to build the robotic equivalent of a Twitter, you won’t start by constructing a computer: “you build the thing that’s new.”
The military, short on linguists, is building smart phone–based devices to do the job
By Gregory Mone
Sakhr Software, a company that builds automatic language translators, recently unveiled a prototype smart phone application that transforms spoken English phrases into spoken Arabic, and vice versa, in near real time. The technology isn’t quite ready for your next trip to Cairo, but thanks to recent advances in machine-translation techniques, plus the advent of higher-fidelity microphones and increasing processing power in smart phones, this mobile technology could soon allow two people speaking different languages to have basic conversations.
Before the 1990s automatic translation meant programming in an endless list of linguistic rules, a technique that proved too labor-intensive and insufficiently accurate. Today’s leading programs—developed by BBN Technologies, IBM, Sakhr and others as part of a Defense Advanced Research Projects Agency effort to eliminate the military’s need for human translators—rely on machine-learning techniques instead. The software works from a database of parallel texts—for example, War and Peace in two different languages, translated United Nations speeches, and documents pulled off the Web. Algorithms identify short matching phrases across sources, and the software uses them to build statistical models that link English phrases to Arabic ones.
John Makhoul, BBN’s chief scientist, says the current technology is at its best when confined to subject areas with specific phrases and terminology—translating a weather report from English into French, for example, or helping soldiers gather basic biographical information from people in the field. Makhoul envisions the first consumer applications, five years from now, being similarly constrained. A tourism-related translation app on a smart phone could help an American in Florence get directions from a non-English-speaking local, but they won’t chat about Renaissance art. “It is not going to work perfectly,” he says, “but it will do a pretty good job.”
Know if Disease Grows Inside You
Complex diseases have complex causes. Luckily, they also leave a multitude of traces
By Melinda Wenner
With the exception of certain infectious diseases, few of humanity’s ailments have cures. More than 560,000 Americans will die of cancer this year, and despite the 250,000 coronary bypass surgeries doctors perform annually, heart disease is still the country’s number-one killer.
The hardest diseases to cure are the ones that take the longest to develop. They are the end result of decades of complex molecular interactions inside your body. Yet this complexity also presents an opportunity. Scientists have discovered that these interactions leave discernible fingerprints on the body. By unweaving the complex tapestry of molecular clues—changes in the body’s proteins, nucleic acids and metabolites, collectively called biomarkers—doctors hope they will soon be able to not only detect disease but predict a coming illness in time to take action.
Biomarkers are not new. Since 1986 doctors have monitored prostate cancer by measuring blood levels of the protein known as prostate-specific antigen (PSA). But tests that rely on a single biomarker to detect disease are rare, because most disorders involve intricate changes in a collection of biomarkers.
Take schizophrenia: in January 2010 scientists will release a biomarker test that distinguishes schizophrenia from other psychiatric conditions. The test, which is being commercialized by Rules-Based Medicine, a laboratory in Austin, Tex., is based on the characteristics of about 40 blood-based proteins.
To find potentially useful biomarkers, researchers collect blood samples from thousands of healthy people and analyze them. Biomarker levels in these samples provide a baseline reading. Then they do the same for people with a specific condition such as diabetes or breast cancer. If reproducible differences emerge between the groups, scientists can use the patterns in the disease group to diagnose the same condition in others. By collecting samples over time, researchers can also go back and analyze early samples from individuals who later become ill to identify patterns indicative of early disease or high disease risk.
Biophysical Corporation, a sister company to Rules-Based Medicine, is one of several companies that has developed blood-based biomarker tests and marketed them to the public [see “The Ultimate Blood Test,” by Philip Yam; Scientific American, June 2006]. The company searches for up to 250 biomarkers suggestive of cancer, inflammatory conditions, heart disease and other illnesses. Mark Chandler, Biophysical’s chair and CEO, says that the real value of the tests lies in long-term monitoring. A person could “get a test monthly, just a finger stick, that would be able to say, we have had a serious change here that is indicative of an early-stage cancer,” he explains.
Yet not all experts are convinced that the age of biomarkers is at hand. Cheryl Barton, an independent U.K.-based pharmaceutical consultant who authored a Business Insights market analysis report on biomarkers in 2006, says she remains “a little bit skeptical about how clinically useful they are.” A study of 5,000 subjects published in the Journal of the American Medical Association in July 2009 found that six cardiovascular biomarkers were only marginally better at predicting heart disease than were standard cardiovascular risk factors, such as whether the subjects smoked or had diabetes.
Adding to the overall difficulty, a person might suffer from two or more diseases—prostate cancer and heart disease, for example. No one knows how multiple diseases might affect overall biomarker signatures or how profiles will change as other diseases develop. “When you get to be 65 or 70, almost everybody has other conditions,” Chandler says. “We don’t know how to deal with that right now.” And scientists still need to discern which biomarkers are truly relevant to disease—a difficult task when working with blood, which contains tens of thousands of proteins at concentrations spanning more than 10 orders of magnitude.
Some companies have simplified the problem by avoiding blood altogether. LabCorp recently commercialized a biomarker test that analyzes colon cells in stool for the chemical signatures indicative of colorectal cancer. “The stool is in intimate contact with the lining of the colon, so it becomes much more highly populated with these rare molecules than would get into the bloodstream from colon cancer,” says Barry Berger, chief medical officer of Exact Sciences, a Madison, Wis.–based biotechnology company that developed the test technology.
In time, scientists are confident that they will eventually crack the more difficult problem of finding distinct disease signatures in the noisy data. “The evolutionary process, being complex and unknown, does not always give us an easy route,” Berger notes, “but it definitely gives us lots of opportunities.”
Satellites Diagnose Disease Outbreaks
Space-based data are helping to track and predict the spread of deadly diseases ?
By Katherine Harmon
Many contagious diseases spread through carriers such as birds and mosquitoes. These vectors in turn move with heat and rainfall. With this in mind, researchers have begun to use satellite data to monitor the environmental conditions that lead to disease. “Ideally, we could predict conditions that would result in some of these major outbreaks of cholera, malaria, even avian flu,” says Tim Ford of the University of New England at Biddeford and co-author of a paper on the subject published this past September in Emerging Infectious Diseases.
Satellite data have already been used to map the advance of the H5N1 avian influenza in Asia. The domestic duck, a common inhabitant of Southeast Asia’s rice paddies, is one of the main carriers of the disease. Xiangming Xiao, associate director of the University of Oklahoma’s Center for Spatial Analysis, uses satellite images to map agricultural patterns in the region. These maps show where the ducks are most likely to live and thus where the avian influenza is most likely to spread.
Migratory birds also carry the virus, but their travel patterns are more difficult to predict. Xiao and his colleagues combine the satellite imagery with satellite-gathered surface-temperature data to estimate the birds’—and thereby the virus’s—trajectory. Computer models then link these environmental drivers to the spread of the flu in human populations.
Of course, not all of the work can be outsourced to orbiting observatories. Xiao says that judging the severity of avian flu’s spread from satellite imaging required knowing details about the human populations as well—for instance, how likely certain communities were to raise ducks for poultry consumption. “Satellite monitoring has a capacity to provide consistent observation,” Xiao says. “On the other hand, the in situ observations are still very, very important, so the key is to combine those together. That is a real challenge.”
More Ideas to watch
By Melinda Wenner
Emergency technicians could prevent up to 35 percent of prehospital trauma deaths if they had better and cheaper ways to prevent blood loss. Now a University of Maryland–affiliated start-up called Trauma Solutions has developed a synthetic hydrogel that can clot blood by prompting the body to make fibrin, a protein that seals wounds and stops bleeding. Future iterations could simultaneously release such medicines as antibiotics and painkillers. Each application will cost about $5, compared with some natural blood-clotting substances that cost upward of $500.
Liver damage is a major side effect of HIV/AIDS and tuberculosis drugs, yet few developing countries have enough trained scientists or equipment to monitor it. Nonprofit Cambridge, Mass.–based Diagnostics For All has developed an inexpensive fingernail-size device made almost entirely of paper that monitors liver damage using a single drop of blood. Channels in the paper guide blood to regions that change color depending on the levels of two damage-related liver enzymes.
Streptococcus mutans bacteria in the mouth decay teeth by converting sugars into enamel-eroding lactic acid. Florida-based Oragenics has genetically engineered a new strain of bacteria that converts sugars to trace amounts of alcohol instead. Because the new strain permanently displaces natural S. mutans, the therapy, which is currently in clinical trials, will be available as a one-time prescription that will protect teeth for life.