Relax And Think Like A Rat | Learning | DISCOVER Magazine

Relax And Think Like A Rat | Learning | DISCOVER Magazine

Don't feel guilty about the breaks you've been sneaking at work—they could be helping you learn. Neuroscientists at MIT find that rats take a similar pause after exploring an unfamiliar maze. During that break, the animals' brains repeatedly review a backward version of the route they just took, most likely cementing memories of the steps needed to reach the goal.

David Foster and his team zero in on this process by placing tiny wires into the rats' brains and then eavesdropping on individual cells. The neurons that light up during the experiments lie in a region known to form short-term memories. But as those cells play the memory again and again—10 times faster than the original experience—the rest of the brain has lots of opportunities to absorb the information and to place it into long-term storage. "This implies that it's not just during an experience that learning occurs," Foster says. "If we're right, the period after the experience is just as important, maybe more important."

The results may explain previous studies showing that people and animals learn best when given breaks between tasks—and provide a persuasive new justification for office daydreaming.

A Better Energizer | Gadgets | DISCOVER Magazine

A Better Energizer | Gadgets | DISCOVER Magazine

If you've ever had a cell phone suddenly die on you, you know that batteries are the weak link in mobile electronics. That's why MIT electrical engineer Joel Schindall thinks the time is ripe for capacitors. "They are better than batteries in almost every way, except in the amount of energy they store," he says. Schindall and his research group have licked that limitation.

Unlike batteries, which produce voltage from a chemical reaction, capacitors store electricity between a pair of metal plates. The larger the area of the plates, and the smaller the space between them, the more energy a capacitor can hold. Schindall's group had a radical idea: Cover the plates with millions of microscopic filaments known as carbon nanotubes. The tiny tubes vastly expand the surface area, creating a perfect sponge for electricity. "Now we can expect to store an amount of energy that is comparable to what batteries store," he says.

A capacitor-powered cell phone could be charged in minutes or seconds instead of hours. And since capacitors can be reused indefinitely, environmental waste from discarded batteries would become a thing of the past. Schindall says battery-free bliss may be less than five years away.

Whatever Happened to Cold Fusion? | Elements | DISCOVER Magazine

Whatever Happened to Cold Fusion? | Elements | DISCOVER Magazine

The scientists who continue to work in the field claim that their experiments show minute, unexplained outputs of energy. Within the year, Hagelstein says, he plans to begin conducting cold fusion research at MIT, an institution that once held a ceremonial wake in cold fusion's honor. He aims to show that novel physical processes can trigger fusion without a significant input of heat. Hagelstein insists that those beyond the inner circle don't know the whole story. "People working in the field believe cold fusion is real and that the issue is settled," he says.

A Vaccine for Your In-Box | Computers | DISCOVER Magazine

A Vaccine for Your In-Box | Computers | DISCOVER Magazine

Shir notes that viruses typically propagate by sending themselves to addresses harvested from Outlook or other similar e-mail programs. He counters this strategy by seeding networks with "honeypot" computers, designed to draw out any active viruses. Each of these computers has a normal-looking e-mail address, but as soon as a virus activates its e-mail system, the computer records the virus's characteristics. It then sends other networked machines a description of the virus's code so that the other computers can block the virus, much as antibodies learn to stop real viruses.

This approach has a leg up on programs like Norton AntiVirus, which require each computer to download a list of virus descriptions compiled by the company that sells the software. "Current antivirus schemes are focused on cleaning the specific computer on which they were installed," Shir says. "Our goal is to immunize the entire network." He says the strategy requires only a modest investment. Simulations show that placing one honeypot among every 250 computers in a network produces such a quick reaction that no virus can infect more than 1 percent of them. Shir hopes to release a commercial version of the software within the next few years.

Autism: It’s Not Just in the Head | Nutrition | DISCOVER Magazine

Autism: It’s Not Just in the Head | Nutrition | DISCOVER Magazine:

"“What we’ve got here is a far more comprehensive set of characteristics for autism,” says Herbert, “one that can include behavior, cognition, sensorimotor, gut, immune, brain, and endocrine abnormalities. These are ongoing problems, and they’re not confined just to the brain. I can’t think of it as a coincidence anymore that so many autistic kids have a history of food and airborne allergies, or 20 or 30 ear infections, or eczema, or chronic diarrhea.”"

Resistant Bacteria: Go Kill Yourselves

Resistant Bacteria: Go Kill Yourselves:

"Researchers at the Hebrew University of Jerusalem have discovered a protein they call 'extracellular death factor' (EDF). Bacteria use EDF to regulate their colonies by inducing suicide in some cells. The protein could be used to create a new class of antibiotics that would effectively treat bacterial species that have grown resistant to conventional antibiotics."

Emerging Technology | Computers | DISCOVER Magazine

Emerging Technology | Computers | DISCOVER Magazine

December, 2005:

When Katrina struck New Orleans on Monday, August 29, similar notices began to appear online—on craigslist, on Yahoo, on the Red Cross Web site. But that information was too scattered to be useful. The queries were everywhere—on dozens of sites. So it was almost impossible to report that someone had been located and be guaranteed that the information would reach the people who needed it. On Saturday, September 3, as the catastrophe worsened, a handful of tech-savvy volunteers led by David Geilhufe started gathering data from these sites by "screen scraping," an automated process that involves grabbing the relevant information for each person—name, location, age, and description—and depositing it in a single database. Geilhufe and his team concocted a standardized method of organizing the data, which they called PeopleFinder Interchange Format.

Still, there were thousands of missing-person notices online the next day that hadn't been converted into the PeopleFinder format because they were not machine readable. Typically these messages were quite simple: for example, "I'm looking for my uncle John who lived in the Ninth Ward—Sarah Bowen." That requires a human to parse the syntax. So that morning two well-regarded online figures—Jon Lebkowsky and Ethan Zuckerman—decided to team up to coordinate a volunteer effort, with Lebkowsky recruiting people to scan through all the online posts and Zuckerman dealing out chunks of data to be analyzed.

By the next morning, PeopleFinder had attracted the attention of a few widely read bloggers. They spread the word to their readers about the need for volunteers. By the end of the day, thousands were volunteering. The group was briefly hamstrung by the database's being overloaded with activity. But by Tuesday night 50,000 entries had been processed, and the number continued to rise dramatically in the days that followed. Meanwhile, people looking for relatives or friends could visit www. katrinalist.net, where the PeopleFinder team provided a search tool that made it possible to enter a name, a zip code, or an address and get a list of names matching the query within seconds.

PeopleFinder was the kind of data-management effort that could have taken a year to execute at great expense if a corporation or a government agency had been in charge of it. The PeopleFinder group managed to pull it off in four days for zero dollars.

"The goal was not to overengineer our tools for the data-entry effort," Zuckerman says, "but to build something very quickly that would let people lend a hand. The solution we came up with was adequate to let 3,000 people participate. And 3,000 people, lightly coordinated, can do impressive things." Zuckerman is reluctant to compare the speed of PeopleFinder with the slow government response to Katrina. "We weren't pulling people from toxic waters," he says. But he does think that the decentralized nature of PeopleFinder has advantages: "One of the reasons PeopleFinder was deployed so quickly is that we had no one to answer to. When no one is approving your work, it's an invitation to solve problems in whatever way you want. I suspect there are many folks involved with the government response who wished they'd had that much flexibility and freedom."

There were other decentralized responses to Katrina. Barely 48 hours after the hurricane hit, two Web designers in Utah launched a site called www. katrinahousing.org to connect evacuees with people all across the country who had a spare bedroom or a guest cottage or even a foldout couch. Two weeks later, 5,000 people had found temporary homes through the site.

Of course, it's impossible to benefit from services like Katrinahousing and Katrinalist if you don't have Internet access. Most of the region affected by Katrina couldn't make a landline phone call after the storm hit, much less log on to the Web. But groups set out to remedy that problem by creating improvised wireless networks in damaged areas, distributing computers and "voice over IP" phones to storm victims and first responders, and establishing low-power FM radio stations in places like the Astrodome. According to the Champaign-Urbana Community Wireless Network home page, the groups involved in the project shipped 2,600 pounds of equipment to the region within days.

The people at the forefront of these efforts had no professional disaster experience. All they had was technical expertise and access to a vast network of people willing to volunteer time, provide shelter, or donate equipment.

Grassroots efforts can replace certain government tasks when disaster strikes.

Killing Cancer With Red-Hot Nanotubes | Nanotechnology | DISCOVER Magazine

Killing Cancer With Red-Hot Nanotubes | Nanotechnology | DISCOVER Magazine

If a silver bullet that kills cancer is ever developed, the man holding the gun might be physical chemist Hongjie Dai of Stanford University. Dai's research team is testing a cancer killer that does not harm healthy cells and acts without drugs or chemotherapy. "It should work for all cancers," says Dai, "because the mechanism is so simple."

Carbon nanotubes (green) take
aim at cancer cell nuclei (red).

Dai's team coats carbon nanotubes—hollow cylinders of carbon only a few atoms wide—in folic acid, a molecule that binds with certain types of cancers, including breast cancer. Once the cancer cells absorb the carbon, the researchers fire a near-infrared laser at the cells for two minutes. The beam passes harmlessly through living tissue, but the nanotubes get so hot they roast nearly all of the cancer cells after one exposure.

Last year, researchers at Rice University developed a similar treatment that uses a near-infrared laser to heat nanoshells—microscopic glass beads coated in gold that are too large to be absorbed by healthy cells but small enough to sneak inside tumors through their blood vessels. The Houston-based company Nanospectra has licensed the treatment, and company president Don Payne expects to begin testing it on cancer patients within a year.

Discover Dialogue: Harvard Clinician John Abramson | Health Policy | DISCOVER Magazine

Discover Dialogue: Harvard Clinician John Abramson | Health Policy | DISCOVER Magazine

November, 2005:

John Abramson is a clinical instructor of primary care at Harvard Medical School. He began his career in Appalachia, serving in the National Health Service Corps. In 1982 he became a family physician in Hamilton, Massachusetts, and practiced there for 20 years. He was selected by his peers three times as one of the best family doctors in the state. After researching his book, Overdosed America, he says health care in the United States is becoming less effective than in other industrialized countries while becoming much more expensive.

Interview:

Enemy Anemones Wage All-Out War | LiveScience

Enemy Anemones Wage All-Out War | LiveScience

When the tide is out, sea anemones sit quiet and still. It's a totally different scene once the tide rolls back in, as neighboring colonies of polyps wage all-out war.

Each colony is an "army," with the troops divided up into scout, warrior, and reproductive rankings, new research shows.

Large colonies of the sea anemone Anthopleura elegantissima claim turf on tidal boulders, which they vehemently defend.

As the tide starts to cover the colonies, "scouts" move to the border and look for empty space to claim. The "warrior" anemones – which are larger and well-armed with stinging cells – provide backup by inflating their arms and slapping at enemies, sometimes from four rows back off the front lines.

Meanwhile, in the center of the colony, poorly armed anemones concentrate on reproduction, making sure there are enough "troops" to maintain the colony.

And they coordinate all these complex behaviors without a single brain among them.

Warring colonies form boundary zones – which can stay in place for years – between the two armies. Anemones that contact soldiers from another colony will fight, whacking each other with special tentacles that stick stinging cells on their enemies.

The research was conducted by David Ayre of the University of Wollongong, Australia and Rick Grosberg from University California, Davis. They had previously studied one-on-one fights between sea anemones, but this study was the first to observe two entire colonies duking it out.

Rankings in the colony appear to depend on a combination of signals from enemy stings and the colony's genetics, say the researchers. Different colonies react differently to similar signals. This causes colonies to organize their troops in different ways.

Sea anemones – named after a terrestrial flower – are water-dwelling, filter feeding animals. As members of the phylum Cnidaria, they are closely related to coral and jellyfish. Sea anemones have a foot which most species use to anchor themselves in sand or attach to rocks. Other species use their foot to attach to kelp, but some are free-swimming.

The new findings, announced today, were detailed in the June issue of the journal Animal Behaviour.

Energy | Alternative Energy | DISCOVER Magazine

Energy | Alternative Energy | DISCOVER Magazine

October, 2005:

In organisms that run the gamut from microbes to magnolias, photosynthesis creates biomass. Water (H2O) plus carbon dioxide (CO2) plus light energy (solar radiation) produces carbohydrates plus oxygen. Normally, no hydrogenase (a natural enzyme that promotes the formation of gaseous hydrogen) is involved in the process. But with microbes, it is possible to intervene genetically in ways that encourage the activation of hydrogenase enzymes. The end result is an altered photosynthetic process that produces less oxygen and more hydrogen.

Researchers at the National Renewable Energy Laboratory in Golden, Colorado, have already succeeded in converting solar energy directly and continuously into hydrogen by manipulating photosynthesis in Chlamydomonas reinhardtii, a common species of green algae. Biologist Michael Seibert and his colleagues found they could activate hydrogenase during photosynthesis by withholding sulfate. “This is a neat little system that shows that you can get an alga to produce hydrogen for days. In fact, we’ve now done it for about six months, continuously,” says Seibert.

Ramping up the efficiency and scale of the photosynthesis-to-hydrogen process to industrial production will be a challenge. But strange as it may seem, visions of pond scum may soon be dancing in energy analysts’ heads. Seibert offers this scenario: “Imagine if 200 million passenger vehicles in this country were fuel-cell driven—and that may be something that happens—and we could get this process working at a 10 percent conversion efficiency. Then it would take an area of bioreactors—hydrogen-impermeable covered ponds, essentially—equivalent to a square plot about 100 miles on each side in, say, New Mexico or Arizona to produce all the hydrogen needed to run those 200 million vehicles.”

Tissue Engineering | Biotechnology | DISCOVER Magazine

Tissue Engineering | Biotechnology | DISCOVER Magazine

To improve those odds, tissue engineers are trying to harness the power of stem cells by designing three-dimensional plastic molds, called scaffolds or matrices, that resemble organs or body parts. When a soup of nutrients and stem cells is squirted over a matrix, stem cells may grow into a hunk of tissue that can later be transplanted into a waiting patient. Somehow, the matrix imparts critical organizing information to the cells.

Researchers have successfully created simple tissues such as skin, cartilage, and bone. More complex structures—an ear and teeth—have also been grown. But the hope is that a complex organ, like a kidney or a heart, can be built.

Customized hearts, arteries, or valves would be a boon because substitutes leave much to be desired. Prosthetic devices can’t grow with young patients. Donor valves, whether from cadavers or pigs, fail after 10 to 15 years and sentence the recipient to a lifetime of immunosuppressive drugs to combat rejection. A heart, artery, or valve built from a patient’s own cells may never be rejected.

In what are among the earliest clinical trials, German researchers have created hybrid replacement valves. They started by removing valves from donor cadavers. Then they stripped the valves of rejection-provoking cells, leaving only an elastin-and-collagen matrix, and seeded the valves with stem cells taken from a vein in the leg or arm. The stem cells knit themselves into this donor matrix and, when the valve was transplanted, functioned well for more than three years. Critics of the protocol say it’s not ideal, because donor heart valves are still in short supply. So researchers are hammering away on two fronts: nailing down how stem cells work—and constructing better matrices.

Oceanography | Robots | DISCOVER Magazine

Oceanography | Robots | DISCOVER Magazine

October, 2005:

Starting next year a global project called Neptune, for North East Pacific Time-series Undersea Networked Experiments, will lay wire-and-fiber-optic cable over a 200,000-square-mile region of the seismically active Juan de Fuca tectonic plate off the northwest coast of the United States. The cables will deliver tens of kilowatts of power so that scientists can plug sensors into the network, sending back real-time data on composition, bacteria, and more. Self-guided robotic devices will eventually be deployed to observe sudden events, such as volcanic eruptions, and then head to underwater bases for recharging. Unlike manned ocean voyages, which are inherently limited to a small crew of scientists, the network will be wired to the Internet, so researchers anywhere in the world can log on. McNutt’s group is building a test site for the American contribution to Neptune.

Nanotechnology | Nanotechnology | DISCOVER Magazine

Nanotechnology | Nanotechnology | DISCOVER Magazine

October, 2005:

How do the basic components of living systems construct themselves in such stunning variety, yet with such unerring precision and with so little energy? Scientists are gradually beginning to discover—and exploit—the rules of autonomous self-organization. Many researchers believe that sort of kinder, gentler dynamic self-assembly will soon be widely available, as scientists learn to nanoengineer more chemicals that can combine only in certain specific orientations, like Lego blocks. Some of the most dramatic accomplishments to date employ self-assembling artificial materials to promote complex biological repair.

Science Education | Physics & Math | DISCOVER Magazine

Science Education | Physics & Math | DISCOVER Magazine

October, 2005:

My early physics education was very strange,” says theoretical physicist Lee Smolin. Strange, but effective. In the early 1970s, Smolin’s mentors at Hampshire College in Amherst, Massachusetts, flipped the usual order of courses, teaching quantum mechanics to freshmen and classic Newtonian regimes to upperclassmen. Smolin, a researcher at the Perimeter Institute for Theoretical Physics in Waterloo, Ontario, and a major contributor to loop quantum gravity theory, worries that the best and brightest students are turning to other disciplines because basic physics curricula are stodgy.

ooOoOoo

DEAN KAMEN, founder of DEKA Research and Development Corporation in Manchester, New Hampshire, and inventor of the Segway Human Transporter, has made it a personal mission to shore up the sagging interest of American teens in science and engineering. In 1992 he founded First—For Inspiration and Recognition of Science and Technology—which runs an annual nationwide robotics competition that provided 74,000 high school students this year with creative motivation and hands-on engineering experience.

What gave you the idea that the span from ages 7 to 17 is a crucial decade when it comes to exposing kids to science and engineering?

K: I looked at my own life and the lives of people I know. Very few people I know get into their twenties, never mind their thirties and beyond, and decide, “I have never done math or science, but I think I will become an engineer or a scientist or a physicist.” Most people, by the time they graduate from high school, have constructed the boundary conditions for what their career options will or will not be.

So the idea is not necessarily to pound more knowledge into kids’ heads during that decade but rather to stretch those boundary conditions?

K: Right. If a kid can come away from a science or engineering program in that decade and think, “I like this, I can do this, this is an option as a career,” then he or she can go on from there and take steps to get the necessary college education.

What if kids don’t?

K: Then we will slide, as other cultures in the world have, into being a second-rate, has-been society. That is a very real risk unless we do something quickly.

Is there an increasing chance that each new generation will be left further behind?

K: Absolutely. A generation or two ago, you could open the hood of a car and, without much training, simply see how it operated. Even a radio—you could see if the tube was lit or not. But now the train is picking up speed. If you don’t grab on, you will be left behind as this thing called technology goes whizzing faster and faster into the future. Take a half-dozen Nobel laureates in medicine in the 1980s: The work that won them the prize is now routinely done in high school biology labs. And there is more competition. This generation of American high school kids will be competing with nearly a billion people of their same generation, people who are hungry for knowledge, passionate and determined to pull themselves up the economic ladder.

Most education in the United States is government funded. Your program runs on corporate donations. What can government learn from you?

K: If our whole program were government funded, there would be strings attached, and it would suffer. But, frankly, it is expensive to run this, so there is a way government funding can help, and it’s a win-win-win situation. Now NASA, as a government agency, needs more scientists, engineers, and roboticists. So well over 100 of our teams are funded directly by NASA this year, and they are fantastic sponsors. This could expand. Let the big science and technology organizations in government—the federal labs, all the places that need technological people—become part of First the same way corporate sponsors do: by adopting high schools and supporting teams.

Does it have to be just with First?

K: No, it’s not a zero-sum game. There is no such thing as a bad program if it gets kids to be more effective at making career choices and becoming responsible citizens. The more we get our program to succeed, the more the other programs it spawns will succeed.

The Brain | Biotechnology | DISCOVER Magazine

The Brain | Biotechnology | DISCOVER Magazine

October, 2005:

Theodore Berger, a professor of engineering at the University of Southern California, is ready for the era of the bionic brain. He has spent 30 years developing computer chips that can link with neurons in an effort to compensate for memory loss. The chips that can do it exist. Most of the software exists. The challenge is to make a reliable, long-term connection between the hardware and the wetware—one that is unaffected by corrosion, scar tissue, or the shifting and dying of cells in the brain. “That’s the big showstopper,” Berger says.

He is part of a growing movement of researchers struggling to perfect neural prostheses, devices that employ electrodes to receive signals from and transmit them to the brain. Cyberkinetics, a company cofounded by neuroscientist John Donoghue at Brown University, has begun clinical trials on an implant that can transmit signals from a paralyzed person’s motor cortex to a computer or to a prosthetic limb. Several groups, including one led by Ali Rezai of the Cleveland Clinic Center for Neurological Restoration, have tentatively shown that stimulation of the thalamus can relieve chronic pain, obsessive-compulsive disorder, and depression. Similar devices may be able to treat blindness, epilepsy, and Parkinson’s disease. All these applications will depend on solving the connection problem.

Nutrition | Nutrition | DISCOVER Magazine

Nutrition | Nutrition | DISCOVER Magazine

October, 2005:

Determining the effect of different nutrients on each gene variant is tricky and revolutionary because it would enable people to optimize their diet according to their particular genetics. Jim Kaput, a nutritional genomics researcher at the University of California at Davis and the University of Illinois at Chicago, notes that a percentage of the population has a polymorphic version of the GPDH gene, responsible for making an enzyme that helps cells convert sugar to energy.

Your Brain on Video Games | Mental Health | DISCOVER Magazine

Your Brain on Video Games | Mental Health | DISCOVER Magazine

July, 2005:

Gee’s epiphany led him to the forefront of a wave of research into how video games affect cognition. Bolstered by the results of recent laboratory experiments, Gee and other researchers have dared to suggest that gaming might be mentally enriching. These scholars are the first to admit that games can be addictive, and indeed part of their research explores how games connect to the reward circuits of the human brain. But they are now beginning to recognize the cognitive benefits of playing video games: pattern recognition, system thinking, even patience. Lurking in this research is the idea that gaming can exercise the mind the way physical activity exercises the body: It may be addictive because it’s challenging.

Earth Without People | Extinction | DISCOVER Magazine

Earth Without People | Extinction | DISCOVER Magazine

February, 2005:

Given the mounting toll of fouled oceans, overheated air, missing topsoil, and mass extinctions, we might sometimes wonder what our planet would be like if humans suddenly disappeared. Would Superfund sites revert to Gardens of Eden? Would the seas again fill with fish? Would our concrete cities crumble to dust from the force of tree roots, water, and weeds? How long would it take for our traces to vanish? And if we could answer such questions, would we be more in awe of the changes we have wrought, or of nature’s resilience?

Worrying About Killer Flu | Infectious Diseases | DISCOVER Magazine

Worrying About Killer Flu | Infectious Diseases | DISCOVER Magazine

February, 2005:

Although any new pandemic would be costly and dangerous, there are good reasons to think that avian flu would be unlikely to morph into a strain that is both virulent and highly transmissible among humans. As Ewald has pointed out, the 1918 flu may have developed its unique virulence, and its unique focus on young adults, precisely because of the terrible conditions in wartime Europe. The disease first appeared as a relatively mild outbreak in the United States in the spring of 1918. A far deadlier form incubated among soldiers on the Western Front. It stalked the trenches, the hospitals stacked with wounded, sick, and dying soldiers, the trucks that carted sick and wounded from one crowded hospital to another, the trains on which the immobilized sick lay face-to-face with the helpless wounded, and the boats that returned ill soldiers to the United States.

Only comparable conditions, Ewald says, would allow the development of a highly virulent and transmissible human flu. As the conditions that created the 1918 flu abated, so did the virulence of the disease and its specificity for healthy people in the prime of life. But it did not disappear. For decades after 1918, H1N1 wandered around the planet, a commonplace flu, no more virulent than any ordinary strain, a killer of the very old and the very young. It spread the way human flu strains always do—coughs and sneezes. Precisely because people have to be healthy enough to walk around and cough into other people’s faces, ordinary human flu strains must be relatively mild to spread. Lethal flu requires the sort of conditions found in the animal markets of Guangdong or the trenches of World War I.

The Chandra X-ray Observatory Center :: Gateway to the Universe of X-ray Astronomy!

The Chandra X-ray Observatory Center :: Gateway to the Universe of X-ray Astronomy!

from P.42 February, 2005:

The Chandra X-ray Observatory Center:

This vast online resource contains Chandra images, scientific explorations and related links.

Testing Darwin | Computers | DISCOVER Magazine

Testing Darwin | Computers | DISCOVER Magazine

February, 2005:

quotes from the article:

The Avida team makes their software freely available on the Internet, and creationists have downloaded it over and over again in hopes of finding a fatal flaw. While they’ve uncovered a few minor glitches, Ofria says they have yet to find anything serious. “We literally have an army of thousands of unpaid bug testers,” he says. “What more could you want?”

00O0O00

Bringing diversity into Avida has brought more bad news for those who think complexity cannot evolve. Ofria decided to run the complexity experiment over again, this time with a limit on the supply of numbers. “It just floored me,” he says. “I went back and checked this so many ways.” In the original experiment, the organisms evolved the equals routine in 23 out of 50 trials. But when the experiment was run with a limited supply of numbers, all the trials produced organisms that could carry out the equals routine. What’s more, they needed only a fifth of the time to do it.

00O0O00

Human society depends on countless acts of cooperation and personal sacrifice. But that doesn’t make us unique. Consider Myxococcus xanthus, a species of bacteria that Lenski and his colleagues study. Myxococcus travels in giant swarms 100,000 strong, hunting down E. coli and other bacteria like wolves chasing moose. They kill their prey by spitting out antibiotics; then they spit out digestive enzymes that make the E. coli burst open. The swarm then feasts together on the remains. If the Myxococcus swarm senses that they’ve run out of prey to hunt, they gather together to form a stalk. The bacteria at the very top of the stalk turn into spores, which can be carried away by wind or water to another spot where they can start a new pack. Meanwhile, the individuals that formed the stalk die.

This sort of cooperation poses a major puzzle because it could be undermined by the evolution of cheaters. Some bacteria might feast on the prey killed by their swarm mates and avoid wasting their own energy making antibiotics or enzymes. Others might evolve ways of ensuring that they always end up becoming spores and never get left behind in the dead stalk. Such cheaters are not theoretical: Lenski and his colleagues have evolved them in their lab.

The Avida team is now trying to address the mystery of cooperation by creating new commands that will let organisms exchange packages of information. “Once we get them to communicate, can we get them to work together to solve a problem?” asks Ofria. “You can set up an information economy, where one organism can pay another one to do a computation for it.”

If digital organisms cooperate, Ofria thinks it may be possible to get them working together to solve real-world computing problems in the same way Myxococcus swarms attack their prey. “I think we’ll be able to solve much more complex problems, because we won’t have to know how to break them down. The organisms will have to figure it out for themselves,” says Ofria. “We could really change the face of a lot of computing.”

ooOoO00

Ofria has been finding that digital organisms have a way of outwitting him as well. Not long ago, he decided to see what would happen if he stopped digital organisms from adapting. Whenever an organism mutated, he would run it through a special test to see whether the mutation was beneficial. If it was, he killed the organism off. “You’d think that would turn off any further adaptation,” he says. Instead, the digital organisms kept evolving. They learned to process information in new ways and were able to replicate faster. It took a while for Ofria to realize that they had tricked him. They had evolved a way to tell when Ofria was testing them by looking at the numbers he fed them. As soon as they recognized they were being tested, they stopped processing numbers. “If it was a test environment, they said, ‘Let’s play dead,’ ” says Ofria. “There’s this thing coming to kill them, and so they avoid it and go on with their lives.”

ooOoOoo

More: http://devolab.cse.msu.edu/

The Evolutionary Origin of Complex Features: R.E. Lenski, C. Ofria, R.T. Pennock, and C. Adami in Nature (2003), pages 139-145.

As the World Warms | Global Warming | DISCOVER Magazine

As the World Warms | Global Warming | DISCOVER Magazine

February, 2005:

Hardly a day goes by, it seems, without fresh evidence of climate change. New reports—from Greenland to Antarctica—show rising temperatures at both poles and changing conditions in what were once stable, icebound areas. A sampling:

• Data from NASA, European, and Canadian satellites show a continuing impact from the collapse of the Larsen B ice shelf in early 2002. Nearby glaciers along the Antarctic Peninsula are now flowing into the open ocean three to eight times faster than when they were buttressed by the ice shelf, contributing significantly to rising sea levels. Additionally, NASA satellites found that some glaciers in the area have thinned by up to 125 feet.

• Populations of krill have declined by 80 percent in the Southern Ocean in the last 30 years. An international team of oceanographers attributed the drop to a loss of winter sea ice that supports the algae on which young krill feed. Krill, small shrimplike creatures, form a cornerstone of the southwest Atlantic food web.

• NASA satellites confirm that the rate of ice flow into the ocean from Greenland’s Jakobshavn Isbrae glacier—the continent’s fastest moving—has doubled between 1997 and 2003, increasing the rate of sea level rise by 4 percent.

• Temperatures are going up twice as fast in the Arctic as in the rest of the world, according to an impact statement by the Arctic Council, a consortium of 14 countries and six organizations of indigenous peoples. Further, the group reports that polar snow cover declined 10 percent in 30 years, and the thaw of permafrost will likely creep hundreds of miles northward within this century. The council also predicts that by the end of the century the famously ice-locked Northwest Passage through the Arctic Ocean will become open water in summer.

93: Broccoli Kicks Cancer | Nutrition | DISCOVER Magazine

93: Broccoli Kicks Cancer | Nutrition | DISCOVER Magazine

January, 2005:

Vegetables pack a roundhouse punch against cancer, according to a September report by nutritional scientist Keith Singletary of the University of Illinois at Urbana-Champaign. Studies had shown that substances in some vegetables help prevent mutations that turn normal cells cancerous. Now Singletary’s research reveals a phytonutrient in vegetables can also kill breast cells that are already cancerous.

Singletary added sulforaphane, a chemical in broccoli, kale, brussels sprouts, and other cruciferous vegetables, to cultures of human breast cancer cells. Within hours, the cells stopped dividing. Sulforaphane seems to work by interrupting the tiny microtubules that normally pull pairs of chromosomes apart when cells divide. Without the tubules, malignant cells can’t multiply. And sulforaphane seems to leave normal cells untouched.

Singletary warns that what happens in the test tube may not be what happens in the body. “We need to better understand the effects of this compound at levels that are physiologically relevant,” he adds. “But what we can say is that this is more evidence that including plant foods in our diets is generally a good idea.”

78: Dietary Study Jolts Scientists | Nutrition | DISCOVER Magazine

78: Dietary Study Jolts Scientists | Nutrition | DISCOVER Magazine

January, 2005:

Even jaded nutritionists, long inured to the public’s atrocious dining habits, were taken aback by the study. “The dose really does make the poison,” says epidemiologist Gladys Block, the study’s lead author. “We knew people ate a lot of this stuff. But that much?”

Not only do these foods fuel the nation’s obesity epidemic, says Block, they are displacing the nutrient-rich fruits and vegetables necessary to fend off disease. The result, Block says, is an unappetizing paradox: a nation of people simultaneously overfed and undernourished.

Under pressure from food manufacturers, health officials have hesitated to demonize particular foods as junk and instead proffer general advice about good nutrition. Block says it’s time to tell Americans to eat more foods that matter—and to say aloud that, nutritionally speaking, some foods do not.

40: Security Scanner Sees Through Ship Containers | Weapons & Security | DISCOVER Magazine

40: Security Scanner Sees Through Ship Containers | Weapons & Security | DISCOVER Magazine

January, 2005:

Scientists at Lawrence Livermore National Laboratory in California began testing a device in May that can quickly detect concealed nuclear materials. The invention could plug a gaping hole in American security: the unexamined 6 million ship containers that enter U.S. ports every year.

Physically searching every container would cause shipping to grind to a halt. Today’s scanners—just big X-ray devices—would miss a terrorist’s nuclear bomb or a lump of enriched plutonium if it were shielded in a simple steel box. The Livermore scanner is not so easily fooled. It bombards a suspect cargo with neutrons. If the neutrons hit fissile material, gamma rays are produced that can be instantly picked up by low-cost detectors. The technique, called active neutron interrogation, readily penetrates most shielding, although it does have an Achilles’ heel. “Lead is transparent to neutrons, but hydrocarbons like agricultural products are tougher,” says Dennis Slaughter, one of the scanner’s originators.

Researchers say that the neutrons emitted by the scanner would pose no threat to operators, to cargo, or even to human stowaways. Livermore physicist Adam Bernstein, leader of detector design, says he and his team are close to their goal: detecting as little as a few pounds of plutonium while taking less than a minute to scan each container and creating no more than one in 1,000 false alarms. Bernstein expects to have a full-size prototype ready to start sniffing cargo containers within a couple of years.

79: Bald Men: This Mouse Is for You | Genetics | DISCOVER Magazine

79: Bald Men: This Mouse Is for You | Genetics | DISCOVER Magazine:

January, 2005:

"Earlier work hinted that skin follicles harbor stem cells kept in reserve to replace epidermal cells when they die. “The critical question was whether there really is a cell that can do it all—epidermis, hair, sebaceous glands,” says Fuchs. “And now we know that we really have a bona fide stem cell.” That means curing baldness could just be the beginning. “Maybe these stem cells could do other things,” says Fuchs. “Maybe they could make corneas for the treatment of blindness.”"

34: Prostate Cancer Test Questioned | Cancer | DISCOVER Magazine

34: Prostate Cancer Test Questioned | Cancer | DISCOVER Magazine

January, 2005:

Back in 1987, Stamey was among the first to suggest that the level of PSA, a protein normally produced by the prostate gland, might be useful in detecting prostate cancer. But based on an analysis of more than 1,300 prostates removed over the past 20 years, Stamey reported in the October issue of the Journal of Urology that the PSA test is currently predictive of cancer in only 2 percent of cases. Because of the increase in screening and detection of prostate cancer over the past two decades, he now says a higher PSA level may most often reflect a harmless age-related increase in prostate size.

When doctors follow up a high PSA level with a biopsy, they often find cancer. But this is only because most men have some degree of prostate cancer. Studies have shown that 80 percent or more of men over age 70 die with—but not from—prostate cancer. As counterintuitive as it seems, detecting prostate cancer is not always in the patient’s best interest. Once cancer is diagnosed, most men opt for treating it either with radiation or removal of the prostate. In many cases, that leads to impotence, urinary incontinence, and other unpleasant side effects.

Turning Point | Global Warming | DISCOVER Magazine

1: Turning Point | Global Warming | DISCOVER Magazine:

January, 2005:

"Evidence of global warming became so overwhelming in 2004 that now the question is: What can we do about it?"

When our grandchildren write the history of global warming—how we discovered and debated it, and what we finally did about it—the stinkbugs that ate Maggs’s tomatoes may not loom large. Nor will the blue mussels that showed up this past year off Spitsbergen, Norway, at 78 degrees north latitude. Nor even the catastrophic failure of Scottish seabirds to breed, which some researchers attributed to a dearth of plankton in the warming waters of the North Sea. But our descendants may well decide that it was the long string of such close-to-home observations—the early springs, the shifting ranges of plants and animals, the mortal heat waves—that, more than any climatological data, convinced people that something needed to be done about global warming. And maybe, just maybe, those future historians will decide that 2004 was the turning point.

Circulation Booster | Heart Disease | DISCOVER Magazine

Circulation Booster | Heart Disease | DISCOVER Magazine

January 2005:

Painful blockages of arteries in the legs—called peripheral arterial obstructive disease, or PAOD—are less familiar than the ones that cut off blood flow to the heart, but they can be just as dangerous. Serious cases can lead to gangrene, kidney damage, stroke, and even death, but arterial bypass surgery or amputation rarely alleviates the condition. Now cardiologist Brian Annex of Duke University Medical Center has found a promising experimental treatment that might cure the disease with little more than an injection.

Annex and his colleagues focused on a gene that induces the body to grow new blood vessels around a blocked artery, a process called angiogenesis. The researchers injected this gene into rabbits with simulated PAOD. Soon the rabbits began producing proteins that triggered angiogenesis in the animals’ legs and halted the process of cell death that leads to gangrene. A few previous studies on animals have induced vessel growth with gene therapy, but this one provides a template for the next stage in the research: clinical trials on humans. One set of clinical trials is already under way at the National Institutes of Health, and another is in the works at Duke University.

Eight million to 12 million people in this country have PAOD; among the 250,000 with the severe form, up to 40 percent die within a year. “We’d love to improve on that,” Annex says.

Genetics: Stephen Fodor | Genetics | DISCOVER Magazine

Genetics: Stephen Fodor | Genetics | DISCOVER Magazine:

November, 2004:

"In the late 1980s, long before the human genome had been sequenced, Stephen Fodor and a few scientist pals in Silicon Valley dreamed of putting the entire human genome on a single glass test chip the size of a thumbnail. Late last year, Affymetrix—the company that Fodor founded and heads as CEO—announced the creation of the whole-genome chip. Researchers and doctors can use it to scan the entire library of human genes and, in a single semiautomated experiment, zoom out and spot the interactive activity of many far-flung bits of DNA in a particular type of cancer, for example, then track the tumor’s response to treatment. Last spring the company created a slightly different tool that promises to be at least as transformative: two tiny glass grids, each containing 50,000 SNPs (pronounced “snips”), or single nucleotide polymorphisms, which can be thought of as all the slightly different spellings of many genetic “words.” Because geneticists use SNPs as markers throughout the genome, this new tool can tease out the link from a particular pattern of widely spaced genes to such complex diseases as autism, diabetes, and cancer. Fodor’s big idea—to wed crisp computer-chip technology to gooey biology—started it all."

Neuroscience: John Donoghue | Machine-Brain Connections | DISCOVER Magazine

Neuroscience: John Donoghue | Machine-Brain Connections | DISCOVER Magazine

November, 2004:

John Donoghue is building a brain decoder that could transform the lives of people paralyzed by injury or disease. Those who have lost the ability to move their limbs often have perfectly intact brains, so Donoghue hopes to implant a chip that can monitor their brain activity and convert their intentions into computer commands. In its current version, the chip’s 100 hair-thin electrodes listen to neurons firing in an area that controls arm movement and translate the activity into electronic signals. A program then decodes the brain signals into commands that direct a cursor on a computer screen. Donoghue hopes the chip can eventually control appliances or even robotic limbs. “We’re effectively rewiring the nervous system—not biologically but with real wires,” says Donoghue. So far, more than 20 monkeys have been equipped with the implanted chip, and four of them have successfully willed a cursor to follow a moving target. Now Cyberkinetics, the company Donoghue cofounded to develop the device they call BrainGate, is preparing to test it in five paralyzed humans. “People with these kinds of injuries are perfectly capable of leading full and productive lives,” says Donoghue. “They just can’t get their signals out.”

This Is Your Ancestor | Human Evolution | DISCOVER Magazine

This Is Your Ancestor | Human Evolution | DISCOVER Magazine

November, 2004:

The sponge is the earliest, most primitive multicelled animal, Sogin says. Some scientists believe the ability to grow different cell types started animals on the evolutionary road to becoming humans. With just a few kinds of cells, only loosely connected, the sponge manages to produce a variety of asymmetrical shapes, from cups and fans to tubes and piecrust shapes. Sponges survive handsomely on their own and can even shelter other sea creatures: Scientists found a large sponge in the Gulf of Mexico hosting 16,000 snapping shrimp and 1,000 other aquatic animals. The sponge’s cells, its calcium carbonate or glasslike silica spicules, and the mass of collagen that forms its visible body all create a network of tunnels and chambers, with little flailing hairs called cilia on the walls that wave the water through and filter out plankton and waste. No matter how large the sponge, it can eat only what its individual cells can absorb.

Sponges are also the earliest sexual reproducers; most are hermaphroditic, producing both eggs and sperm, which they release into the water. The sperm drift along until they find their way into the tunnels and caves of another sponge. But the sponge has other reproductive options. If you push one through a sieve, breaking free its individual cells, these cells will drift until they find each other, then stick together and create an exact genetic duplicate of the parent. If wounded, a sponge doesn’t need to grow new tissue; it simply moves old cells into the wound to close it. These techniques have helped sponges survive at least 500 million years. A few have remarkable capabilities. One, living in a Mediterranean underwater cave, traps small crustaceans with the sharp, glassy spikes jutting from its body, then surrounds them with its cells and digests them.

Biologist Calhoun Bond, then at the University of North Carolina at Chapel Hill, found in 1986 that sponges don’t just sit still—many actually move. Using time-lapse microscopy, he filmed freshwater sponges slowly crawling across the bottom of their containers. He found that larger, saltwater sponges do the same by extruding flat paddlelike extensions of their bodies and pulling themselves along, often climbing the sides of their glass tanks in labs. One sponge, a lavender beauty called Heliclona loosanoffi, moved four millimeters a day.

Cancer's Master Genes | Cancer | DISCOVER Magazine

Cancer's Master Genes | Cancer | DISCOVER Magazine

November, 2004:

The idea that everybody’s genes are pretty much the same, a central conceit of the Human Genome Project, may need some revising. A group of researchers has accidentally discovered that our DNA contains substantial areas of repeated genes—and the location and number of these genetic echoes vary considerably from person to person.

Biologist Michael Wigler of Cold Spring Harbor Laboratory, who led the study, started out studying genes in cancer cells but soon realized he was seeing unexpected patterns in the healthy cells he examined for reference. Although he does not know exactly what the large-scale repeats mean, he suspects that the number of genes a person is carrying may be just as important as the codes those genes contain. “More copies probably means more expression of whatever that gene is coding for,” he says. Several of the repeated regions involve genes regulating appetite and body weight; others occur in regions associated with breast cancer, leukemia, and nerve development, leading Wigler and his teammates to speculate that differences in these copied genes could help explain why some people are particularly susceptible to obesity, cancer, or neurological diseases.

If the disparities are so large, why has nobody found them before? Part of the answer is simply that the most commonly used DNA probes tell whether or not a given sequence is present, not how many times it appears in an individual cell. As a result, researchers have tended to focus on point variations, such as the mutation or deletion of a single DNA letter within a gene. “People have known isolated cases where this sort of multiple copying existed,” Wigler says. “But everyone assumed that these were just anomalies, and so it wasn’t something anyone was looking for.”

We're Not So Alike After All | Genetics | DISCOVER Magazine

We're Not So Alike After All | Genetics | DISCOVER Magazine

November, 2004:

The idea that everybody’s genes are pretty much the same, a central conceit of the Human Genome Project, may need some revising. A group of researchers has accidentally discovered that our DNA contains substantial areas of repeated genes—and the location and number of these genetic echoes vary considerably from person to person.

Biologist Michael Wigler of Cold Spring Harbor Laboratory, who led the study, started out studying genes in cancer cells but soon realized he was seeing unexpected patterns in the healthy cells he examined for reference. Although he does not know exactly what the large-scale repeats mean, he suspects that the number of genes a person is carrying may be just as important as the codes those genes contain. “More copies probably means more expression of whatever that gene is coding for,” he says. Several of the repeated regions involve genes regulating appetite and body weight; others occur in regions associated with breast cancer, leukemia, and nerve development, leading Wigler and his teammates to speculate that differences in these copied genes could help explain why some people are particularly susceptible to obesity, cancer, or neurological diseases.

If the disparities are so large, why has nobody found them before? Part of the answer is simply that the most commonly used DNA probes tell whether or not a given sequence is present, not how many times it appears in an individual cell. As a result, researchers have tended to focus on point variations, such as the mutation or deletion of a single DNA letter within a gene. “People have known isolated cases where this sort of multiple copying existed,” Wigler says. “But everyone assumed that these were just anomalies, and so it wasn’t something anyone was looking for.”

The Biology of . . . Migraines | Mental Health | DISCOVER Magazine

The Biology of . . . Migraines | Mental Health | DISCOVER Magazine

Upton held the magnetic stimulator next to Hughes’s head and pressed a button, sending out two pulses five seconds apart. Hughes says he felt a “surge, like a rush of energy” entering his head. Minutes later, after a second round, the headache was gone. No more pain, no more agonizing sensitivity to light when the blinds were opened. “It was amazing,” Hughes says. “Like a flood of release of the pain and pressure. You’ve no idea unless you’ve had migraines. I even drove home.”

In Upton’s clinical trials, three-quarters of all test subjects who arrived at the hospital suffering from a migraine reported feeling much better immediately after treatment. Better yet, every one of Upton’s subjects who has made it to the hospital during the aura phase has found that the magnetic stimulator dispels the aura and prevents the headache from occurring. Migraine drugs all have some side effects, including nausea, chest discomfort, and sometimes rebound headaches. But no side effects have yet been detected as a result of using the stimulator. In fact, Upton says, if the cycle of headaches—or seizures, for epileptics—is broken, then the patient may “forget” the pattern of electrical activity that leads to the symptoms. Since Hughes’s first three treatments, he hasn’t had a migraine in three years.

Discover: The FCC's map of the U.S. radio spectrum

How Radio Changed Everything | Technology | DISCOVER Magazine

NASA - Stellar Fireworks

NASA - Stellar Fireworks





Resembling an aerial fireworks explosion, this dramatic image of the energetic star WR124, taken by the Hubble Space Telescope, reveals that it is surrounded by hot clumps of gas being ejected into space at speeds of over 100,000 miles per hour.

Also remarkable are vast arcs of glowing gas around the star, which are resolved into filamentary, chaotic substructures, yet with no overall global shell structure. Though the existence of clumps in the winds of hot stars has been deduced through spectroscopic observations of their inner winds, Hubble resolves them directly in the nebula M1-67 around WR124 as 100 billion-mile wide glowing gas blobs. Each blob is about 30 times the mass of the Earth.

The massive, hot central star is known as a Wolf-Rayet star. This extremely rare and short-lived class of super-hot star is going through a violent, transitional phase characterized by the fierce ejection of mass. The blobs may result from the furious stellar wind that is unstable as it flows into space. As the blobs cool, they eventually will dissipate into space and so don't pose any threat to neighboring stars.

The star is 15,000 light-years away, located in the constellation Sagittarius. The picture was taken with Hubble's Wide Field Planetary Camera 2 in March 1997. The image is false-colored to reveal details in the nebula's structure.

Image credit: NASA/Yves Grosdidier (University of Montreal and Observatoire de Strasbourg), Anthony Moffat (Universitie de Montreal), Gilles Joncas (Universite Laval), Agnes Acker (Observatoire de Strasbourg)

NASA - The View From Iapetus

NASA - The View From Iapetus

(click on image for hi-res version)

turing tests and chatterbots

see "From Russia, with Love," Sci. Am. Mind, Oct/Nov. 2007 @16, by Robert Epstein, co-editor of the [upcoming] book Parsing the Turing Test: Philosophical and Methodological Issues in the Quest for the Thinking Computer. As [not] seen in my twitterstream. Do you follow me?

Epstein, an AI researcher & expert on the Turing Test, got fooled by a chatterbot for 4 months.

APOD: 2007 October 7 - Two Million Galaxies

APOD: 2007 October 7 - Two Million Galaxies

Explanation: Our universe is filled with galaxies. Galaxies -- huge conglomerations of stars, gas, dust -- and mysterious dark matter are the basic building blocks of the large-scale universe. Although distant galaxies move away from each other as the universe expands, gravity attracts neighboring galaxies to each other, forming galaxy groups, clusters of galaxies, and even larger expansive filaments. Some of these structures are visible on one of the most comprehensive maps of the sky ever made in galaxies: the APM galaxy survey map completed in the early 1990s. Over 2 million galaxies are depicted above in a region 100 degrees across centered toward our Milky Way Galaxy's south pole. Bright regions indicate more galaxies, while bluer colors denote larger average galaxies. Dark ellipses have been cut away where bright local stars dominate the sky. Many scientific discoveries resulted from analyses of the map data, including that the universe was surprisingly complex on large scales.

APOD: 2006 January 19 - Orion Nebula, The Hubble View

APOD: 2006 January 19 - Orion Nebula, The Hubble View