Sommaire pour March 2013 de Discover

Teamwork Pays Off “The Cooperation Instinct” (page 34) focused on the work of Martin Nowak, a Harvard biologist whose computer models show that cooperation is a natural offshoot of Darwinian evolution. Cooperation is not altruism. Altruism is the apparently unique human instinct to sacrifice ourselves for strangers, with no anticipation of a payback. Not only will we run into a burning building to save a trapped child to whom we have no connection, we will also crawl out on the ice of a frozen pond to save a deer that has fallen through—the same deer that we would happily shoot if out hunting the next day. I suggest that the next challenge for Nowak is to reconfigure his model to solve the fundamental question of whether altruism can appear and…

IN 2009, THE CENTERS FOR Disease Control and Prevention (CDC) received a plea from officials in Uganda: Could the agency investigate a mysterious head-nodding disease spreading among more than 3,000 young people there? Healthy children would suddenly begin to nod their heads uncontrollably, sometimes falling into a trancelike state. The incidents seemed to be triggered by food, so eating was a struggle for the victims; some were dying of malnutrition as a result. “We saw families lock their children in their homes or tie them to trees to prevent them from injuring themselves while the family was working,” says the CDC’s Scott Dowell, an infectious disease specialist charged with finding the cause. Examining the children with brain scans, Dowell determined the spells were seizures like those seen in epilepsy. But…

WHEN IT COMES TO MANEUVERABILITY, modern flying machines pale in comparison to an everyday pigeon. Birds can flap their wings to swoop, dive, glide, and alight on perches. Fixed-wing airplanes and rotary-wing helicopters rarely show that dynamism. In recent years, though, scientists have started finding ways to mimic the mechanics of bird flight through various robotic ornithopters, aircraft that fly with flapping wings. Aircraft based on today’s lab experiments could soon find use in military or search-and-rescue missions. One of the most impressive of the new flock is SmartBird, a prototype flier made by Festo, a German-based automation technology company. The remote-controlled aircraft has wowed audiences on a worldwide tour as it uncannily flies like its avian inspiration, a herring gull. Made mainly of carbon fiber, SmartBird weighs 0.88 pound…

CONVENTIONAL WISDOM: Fish should only be caught as adults, after reproducing. CONTRARY VIEW: Catching only adult fish harms ecosystems. Fishermen call them keepers: the mature fish above the legal minimum length that end up in the ice chest, as opposed to the small fry that get tossed back. Size regulations apply to everyone from a retiree hooking a sturgeon (minimum length: 43 inches) on Oregon’s Columbia River to a trawler pulling up cod (minimum length: 22 inches) off some of New England’s coast. Ignore the rules, and you’ll be fined. The rationale is that young fish should be left in the population until they can mature and breed — and, besides, larger fish make for better fillets. The problem is that selective harvesting has been counterproductive, altering natural ecosystems and…

More than 20 years after control freaks first reigned over their own pixelated populations, SimCity reboots with a new simulator engine, GlassBox, that brings unprecedented detail to the screen. Past simulators for the build-a-city game generated animations based on statistics of how urban systems work, but GlassBox uses software agents acting both independently and together to create more dynamic, highly realistic events. Other advances include more multicity play options and a nifty new tool to create curvy roads. In stores and online March 5. SimCity.com…

3-9 National Severe Storm Preparedness Week Be ready for thunderstorms, floods, and tornadoes before springtime severe weather hits; many states will conduct tornado drills and emergency siren tests. nws.noaa.gov/om/severeweather Night of the Comet Spot the comet Pan-STARRS with the naked eye as it reaches its perihelion, the closest it comes to our sun. astronomy.com/panstarrs2013 8-10 Geek Freak Weekend Princeton, N.J., celebrates Pi Day and Albert Einstein’s birthday (both 3.14) with pi recitations, a pie-eating contest, an Einstein Look-A-Like Contest, and a “No-Socks Sock Hop.” pidayprinceton.com 13 Registered Dietitian Day When thanking your friendly registered dietitian for helping people enjoy healthy lives, here’s a tip: Skip the celebratory cake with extra frosting. eatright.org/NNM 17 The Chemistry of St. Patrick’s Day Chicago sees green once again as the city colors its river…

EVOLUTION IS LIKE A SEARCH ENGINE, THOUGH NOT A very good one. We’re not talking Google. We might be talking Google drunk, blindfolded, on crutches, and with a frontal lobotomy. This is why the Nobel laureate François Jacob described evolution as a tinkerer, not an engineer. Engineers know where they’re going—they have an aim, a plan. Tinkerers are just fastening parts together, sticking this bit onto that in an ongoing exploration of functional possibilities, with no goal in mind. The insight that the evolutionary search engine proceeds blindly—and therefore gradually—came from Charles Darwin. He realized that because resources are often scarce, organisms are always in competition with one another. In the endless battle, those individuals who happen to possess some slight innate advantage will flourish and pass along that advantage…

David Reich, a geneticist at the Harvard Medical School, has redrawn our species’ family tree. And today, in his office overlooking Avenue Louis Pasteur in Boston, he picks up a blue marker, walks up to a blank white wall, and shows the result to me. He starts with a pair of lines—one for humans and one for Neanderthals—that split off from a common ancestor no more than 700,000 years ago. The human branch divides into lineages of Africans, Asians, and Europeans, and then into twigs for smaller groups like the people of New Guinea or the residents of the remote Andaman Islands in the Indian Ocean. Reich also creates a branch off the Neanderthal line for the Denisovans, a paleolithic lineage geneticists discovered only a few years ago. All well…

On the uncharacteristically cool morning of July 22, 2009, 24 scientists gathered at the National Institutes of Health in Bethesda, Maryland. The topic: a troubling new retrovirus called XMRV. A paper in the journal Science was about to implicate the virus as the cause of a devastating disease with a dismissive name: chronic fatigue syndrome, or CFS. Doctors have compared the worst cases of CFS to end-stage AIDS. CFS patients have cancer rates that are significantly elevated and immune systems that are seriously impaired. The disease can confer a kind of early dementia and may shorten its victims’ lives by 20 years. Scientific explanations for the rise of CFS cases, a phenomenon dating to the mid-1980s, have mostly focused on viruses, but psychiatric theories have abounded, too, driven primarily by…

SEPTEMBER 2, 1859, WAS A TERRIBLE day to be working in the information industry. Telegraph machines around the world behaved as if possessed. They spat out electric shocks and set telegraph paper on fire. Some of the machines continued to send and receive messages even after they were disconnected from the batteries that powered them. One man saw how it all began. The day before, Richard Carrington, a British brewer’s son who rose to be the foremost solar astronomer of the time, had observed an extraordinary event. He was examining an 11-inch-wide projected image of the sun, part of his routine monitoring of the solar surface, when he noted the eruption of “two patches of intensely bright and white light ... the brilliancy ... fully equal to that of direct…

WHEN I WAS NINE YEARS OLD I DISCOVERED A SIMPLE KIND of time travel. I had just recently learned the constellations and started to recognize that each time of year has its own distinctive landscape in the evening sky. But if I woke up at 4 a.m. and went outside, I realized, I could jump ahead a full season, or even two. On a crisp November night I could set my alarm clock (the old wind-up kind, with an actual bell) and catch a glimpse of orange Arcturus rising in the east, a harbinger of spring. The tangy smell of frosty predawn air only added to the magical sense of peering into the future. Last month I wrote about the history of discover’s New York editorial offices, which will have…

When the Curiosity rover discovered evidence of an ancient stream bed on Mars in late September, it was an important and reassuring discovery. In fact, scientists have found increasing evidence of water on numerous moons, planets, and asteroids in recent years—an encouraging trend for those who see the familiar substance as the backbone of a future space-based economy. By harvesting water and converting it into a hydrogen-based rocket fuel, a space mining company like Shackleton Energy of Austin, Texas, could become the Exxon Mobil of the interplanetary highway. “If they can figure out the engineering and the economics, the raw materials are out there,” says planetary scientist Andrew Rivkin of Johns Hopkins University. Here are six of the more interesting water worlds and the prospects for each. GREG MONE 1.…

A simple drink of water laced with hydrogen gas might prevent some of the brain damage resulting from strokes, new research conducted in mice suggests. The gas seems to act as an antioxidant, protecting brain cells from the toxic aftereffects of oxygen starvation that strokes can cause. In ischemic stroke, a clot blocks blood flow to part of the brain, killing neurons in its wake. But the worst damage often happens after the clot dissolves and surviving brain cells revive. The cells release reactive oxygen species, molecules that damage and kill cells. A recent experiment by pharmaceutical scientist Mami Noda of Kyushu University and neurologist Bruce Ransom of the University of Washington points to a solution. The mice in their study drank water enriched with hydrogen gas for 7 to…

Get Mooned in Beantown The Museum of Science, Boston, MA No mere planetary sidekicks, the many moons of our solar system take center stage in the Charles Hayden Planetarium’s newest show. Moons: Worlds of Mystery, produced by planetarium staff at Boston’s Museum of Science, showcases the beauty and variety of the 165-plus satellites in orbit around our system’s planets. The cast of characters includes Mars’s Diemos, a “city-sized, potato-shaped” hunk of rock, according to producer Dani LeBlanc, as well as Saturn’s rings, which may be the remains of a moon that got too close to the planet and was ripped apart (see page 50). The show debunks many myths about our own moon, and examines how its pull on our planet may have slowed Earth’s rotation to a speed more…

The latest addition to the fleet of Battlestar Galactica spin-offs touches down in multiple formats, including Blu-ray, DVD, and UltraViolet for mobile streaming. Battlestar Galactica: Blood & Chrome debuted online as 10 short episodes via Machinima Prime’s YouTube channel in late 2012. The new combo pack collects that material into a two-hour movie, fleshing out the story of young Captain William Adama (Luke Pasqualino) and his jaded co-pilot Coker (Ben Cotton) with additional scenes and bonus features. Available February 19.…

IF YOU COULD TAKE A CELL FROM ANY organism—an alga, giant sequoia, condor, or your second cousin—and dive through its membrane into its clear liquid cytoplasm interior, you would find that all life as we know it shares the same building blocks. Familiar amino acids and proteins initiate and accelerate the same chemical reactions in precisely the same ways, regardless of the organism. And all known life uses liquid water as a foundation. It is for these reasons that biologists believe that you, me, the flea, and the bonobo all descended from a single common ancestor: a microbe that lived some 3.5 billion to 3.8 billion years ago and (luckily for us) reproduced, eventually evolving into all of the living things we see, and don’t see, around us. Biologists call…

Today stem cells have been used to grow ears, tracheae, and bladders; tomorrow it will be just about any tissue, any structure, of the human body. This means repairs to old, corrupted, or broken tissues. It doesn’t take a soothsayer to see that this technology is going to radically extend life span. More interesting, perhaps, is what it might mean for consciousness (arguably a process governed by evolution). Our perception of time impacts our perception of the world. How deep this goes is unknown, but it is conceivable that a short-lived fruit fly has an experience of reality that is radically different from that of a long-lived turtle. as we start to push back death with tissue engineering, the downstream impact could reshape the way we see the world.…

SETH FIKKERT HAD A HEAD COLD. THE 30-YEAR-OLD worked in a hospital and had two kids, so he didn’t think much of it. But after three weeks, he still felt short of breath, and his 2-year-old son was coughing a little, too. Fikkert, who resembles Jim from the NBC television show The Office in both his boyish good looks and his sharp sense of humor (he jokes about the mispronunciations his last name inspires), lived in Everett, Washington, which last summer was in the midst of one of the country’s most serious whooping cough epidemics. So he thought it best to get tested. “I just wanted to rule it out,” Fikkert says. He had gotten his adult booster for pertussis, the bacterium that causes whooping cough, only a year before,…

MARCH 2006 >>>> XMRV is named by Robert Silverman in a study linking the retrovirus with prostate cancer. SUMMER 2006 >>>> Mikovits meets Annette Whittemore and Dan Peterson. Shortly thereafter she moves to Nevada and begins her work on CFS. OCTOBER 2009 >>>> Mikovits, Ruscetti, et al. publish paper in Science linking XMRV to chronic fatigue syndrome. JANUARY 2010 >>>> Criticism of the XMRV link begins in earnest with the publication of a paper by scientists working at Imperial College London. SEPTEMBER 2011 >>>> Science’s editor-in-chief, Bruce Alberts, publishes a unilateral retraction of the 2009 Mikovits study. WINTER 2011 >>>> Ian Lipkin is brought on board to act as impartial third party. Collaboration study begins. SEPTEMBER 2012 Paper is published disproving link between XMRV and CFS.…

THE CRESCENT MOON IS ONE OF MOST UBIQUITOUS SYMBOLS OF THE NIGHT SKY, AND ONE of the most misunderstood. Children’s books are rife with crescents, often used to signal that a story ends at bedtime. And yet for those of us north of the equator, almost all of those moons face the wrong way: illuminated on the left, like a letter C. In reality, at mid-northern latitudes, the evening crescent moon is lit up on the right, facing toward the western sky where the sun has just set. The left-illuminated moon is the one we see when it appears just before dawn, a cruel time to put a child to sleep. Look closely at a thin waxing crescent—you’ll see a nice example on the 16th of this month—and you will…

IN A WELL-KNOWN SCENE FROM The Matrix, Neo (played by Keanu Reeves) lies down in a high-tech dentist’s chair and straps on a wild array of electrodes, downloading a series of martial arts training programs into his brain. Apparently—if the mechanics can be parsed—the information is transferred via the visual cortex. Afterward, he blinks his eyes open and speaks the words geeks have been quoting ever since: “I know kung fu.” Automatic learning, the technical term for this idea, has been a longtime dream of the cyberpunk set. Most people thought it would remain in this aspirational realm for a while longer, but thanks to recent research by Brown University neuroscientist Takeo Watanabe, what has long been science fiction may soon become science fact. To understand Watanabe’s breakthrough, it helps…

The loon has long been a sentinel creature for detecting mercury in our waters. “Loons, because they are exclusively fish eaters, are a great indicator of how bad mercury can get in the wild,” says ecologist David Evers, chief scientist at the Biodiversity Research Institute, a nonprofit organization in Gorham, Maine. But now ordinary sparrows and backyard birds may join the club, providing researchers with a broader picture of mercury’s effects on the environment. In a new study, Evers’s colleagues found high levels of mercury in the feathers of saltmarsh sparrows living in the wetlands of North Cinder in New York’s Long Island. Whereas loons accumulate mercury by eating large fish, songbirds are poisoned by eating spiders and other bugs. “You might ask what difference it makes if a little…

A curious thing happens to white-faced capuchin monkeys when they anoint their bodies with mud and plant matter, a natural insect repellent: With their heads and faces slathered in goop, these highly social primates lose their ability to recognize each other. Previously friendly monkeys can become fighting foes. This abrupt change in behavior hints at the importance of facial expressions for recognition, University of Washington evolutionary biologist Sharlene Santana says, and could help to explain why primate faces are so wildly divergent: Some species, like white-faced capuchins, have monotone hair and skin color; others, like the northern owl monkey, sport a dramatic mix of fur and flesh tones. Biologists have long seen primates’ facial expressions during social interactions as clues that factors like group size drove the stark differences in…

THE LADY AND HER MONSTERS Lightning crackles overhead as 18th-century Italian physiologist Luigi Galvani strings up partly dissected—and very dead—frogs, hoping to reanimate them. From this opening scene, writer Roseanne Montillo plunges readers into a world of grave robbing and gruesome medical experimentation. Montillo uses the classic novel Frankenstein as her starting point to explore the shady science and changing social mores that inspired Mary Shelley’s 1818 tale, and folds details of Shelley’s personal life into a broader history of early anatomists and alchemists. Although they failed to crack the secret of creation, many, such as 16th-century alchemist Paracelsus, made valuable contributions to medicine and metallurgy. With a flair for both drama and detail, Montillo breathes her own kind of life into the story of the men determined to discover…

Charles Fernyhough Most of us believe our memories are fixed, like snapshots in our own personal scrapbooks. But in his latest book, Pieces of Light, award-winning author and psychologist Charles Fernyhough points to research that shows our minds revise memories with every recall. DISCOVER associate editor Gemma Tarlach talked to Fernyhough about the mutability of memories—and whether we’ll ever remember things as they really happened. What reaction do people have to learning memories are not carved in stone? Some people respond, “Who’s this guy to tell us we’re wrong?” But we don’t get the past wrong wholesale. We just mash up parts that don’t necessarily go together. Since researching Pieces of Light, do you find yourself more aware of your own memory processing? I think I’m more skeptical and more…

FROM THE EXAM-ROOM DOOR, I looked past the waiting room, across a dirt road toward shacks baking in the desert heat. It was noon in Baja, Mexico, and we needed to finish up soon to get back to California before sundown. Our small group of doctors, nurses, translators, and pilots had flown to this little fishing village the day before to run our monthly two-day clinic. Some of the folks we treated had struggled over dusty roads for four hours to get to us. We had one last patient. A volunteer brought in a woman who, I was told, was in her early thirties. She looked much older. In this part of the world, that is not uncommon. Conservatively dressed, she seemed unfamiliar with the clinic, a bit shy, unsure…

Although bionics hasn’t yet given us the six-million-dollar man, we are not that far away. Already there are soldiers returning to combat with bionic limbs. Already we have built robots smaller than the period at the end of this sentence. When you bring these two trends together, the result is a series of talents far different from our own. Consider cochlear implants. In his 2009 TED talk, biology visionary Juan Enriquez predicted that we are 10 to 15 machine generations from the point at which the deaf will be able to hear normally. Then, he continued, a few years later “they’ll be able to hear how bats sing or how whales talk, or how dogs talk, and other types of tonal scales. They’ll be able to focus their hearing…and do…

Since its launch in 1997, the Cassini spacecraft has traveled more than 3.85 billion miles. It has sent back 450 gigabytes of data, including more than 300,000 images of stormy Saturn, its majestic rings, and its rich and complicated system of moons. But perhaps the most notable number of the mission is 1: That is how many people oversee the creation of what may well be the most remarkable photo album ever assembled. Carolyn Porco is the one. As the leader of the imaging science team on the Cassini mission to Saturn, she oversees collection and analysis of all the high-resolution pictures the spacecraft sends home. She has also done more than anyone else to spread interest in Saturn and its intricately beautiful rings and moons. She shares Cassini’s discoveries…

AFTER SPENDING A FEW DAYS IN bed with the flu, you may have felt a bit stupid. It is a common sensation, that your sickness is slowing down your brain. At first blush, though, it doesn’t make much sense. For one thing, flu viruses infect the lining of the airways, not the neurons in our brains. For another, the brain is walled off from the rest of the body by a series of microscopic defenses collectively known as the blood-brain barrier. It blocks most viruses and bacteria while allowing essential molecules like glucose to slip through. What ails the body, in other words, shouldn’t interfere with our thinking. But over the past decade, Jonathan Kipnis, a neuroimmunologist in the University of Virginia School of Medicine’s department of neuroscience, has discovered…

1. In the coming weeks, bears, squirrels, marmots, and many other beasts will emerge from hibernation. An extended period of inactivity might sound relaxing, but hibernation is very different from rest. 2. Actually, it would be more like having a stroke. Oxygen flow to the gray matter of hibernators can drop to as little as 2 percent of normal. 3. Metabolic activity and heart rate also plummet. A ground squirrel’s heart rate can drop from 300 beats per minute to three or four ticks in the same span during hibernation. 4. It’s not just for winter: In tropical Madagascar, the fat-tailed dwarf lemur crawls into tree-holes and shuts down for an average of seven months to deal with a dearth of food and water during the dry season. 5. Warm-weather…