শনিবার, ১৭ ডিসেম্বর, ২০১১

2011 Science News of the Year

You can?t make this stuff up.

An earthquake and tsunami trigger the worst nuclear accident in decades, contaminating thousands of square kilometers in one of the world?s most densely populated countries. Analyses of a sliver of finger bone reveal that the genes of an extinct human relative survive in many people living today. Single-celled organisms floating in a test tube join up, with a little coaxing, to create multi-cellular organisms in what could be a reenactment of one of the most seminal events in the history of life.

You don?t have to make it up, though, because it all happened in 2011. Some of the year?s revelations were downright unnerving: Sea level is rising at an accelerating rate and Arctic ice cover continues its long-term decline. On the economics front, network analysis has revealed that the world?s capital really is concentrated in the hands of just a few players.

But there are reasons for optimism, too. Research hints that antidepressants can stave off Alzheimer?s disease, and a vaccine against malaria shows signs of effectiveness in African children. By mining electronic medical records, researchers in Denmark have drawn possibly informative links between unlikely pairs of ailments, such as migraines and hair loss.

Then there were the stories that were just too wild to be true: Neutrinos appeared to violate Einstein?s theory of relativity by flying faster than light, but other work suggests they were doing no such thing. And a 2009 study linking chronic fatigue syndrome to a wily virus called XMRV has been retracted, triggering spasms of finger-pointing among virologists.

And all of this news appeared in the pages of Science News. In case you missed any of it, read on. ?Matt Crenson, News Editor

On the Web? For the complete year-end recap with links to the original online articles, visit www.sciencenews.org/2011

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SCIENCE & SOCIETY

Following earthquake and tsunami, radiation is Japan?s true aftershock

The worst earthquake in Japan?s recorded history ? and, at magnitude 9.0, one of the most powerful ever recorded ? didn?t end when the shaking did on March 11. Within hours, a meters-high tsunami swamped much of the coastline, including the Fukushima Daiichi nuclear power station, setting off the worst nuclear accident since the 1986 Chernobyl meltdown in Ukraine (SN: 4/9/11, p. 5).

Three reactors at the Fukushima plant exploded, releasing radioactivity carried by winds across Japan and then around the globe (SN Online: 3/19/11). Radiation physicists continue to argue about how much radioactive material, such as cesium-137, escaped, with independent assessments often coming in much higher than the Japanese government?s official numbers. In late November the Tokyo Electric Power Co., which operates the plant, announced that at the worst-hit reactor, Unit 1, fuel rods had probably melted completely during the accident and pooled in the concrete bottom of the containment vessel.

Workers continue to try to cool and stabilize the damaged reactors; it could be years before the cores can be opened up and disposed of. Meanwhile, villages around the plant remain evacuated and may be uninhabitable for decades. ?Alexandra Witze

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Weather unrest? One in five major civil conflicts since 1950 may be linked to climate extremes associated with El Ni?os, a study finds (SN: 10/8/11, p. 16).

Rule by a few? A handful of individuals can enslave an entire network, even if they aren?t highly connected themselves. Scientists have found a way to identify these individuals, which might lead to more secure power grids, marketing campaigns that spread like the plague and tricks for controlling a cell?s metabolic growth processes (SN: 6/4/11, p. 5). Other work uses 2007 data to diagram the relationships among more than 43,000 corporations, showing that a tightly connected core controls more than one-third of global wealth (SN: 9/24/11, p. 13).

Acid test fails? Contrary to claims made by informants within the Sicilian Mafia, sulfuric acid won?t dissolve a corpse in minutes, research reveals (SN: 3/26/11, p. 16).

Linked up? Integrating data from clinicians? notes with protein and genetic information reveals connections between health problems as seemingly unrelated as migraines and hair loss, or glaucoma and a hunching back (SN: 10/8/11, p. 16).

Crop dents? Farms around the planet produced 3.8 percent less corn and 5.5 percent less wheat than they could have between 1980 and 2008 because of rising temperatures, a new analysis estimates (SN: 6/4/11, p. 15).

Personnel stress? Service and support personnel face considerable and often overlooked war stress (SN: 9/24/11, p. 9).

The data?age? The fraction of the world?s data stored digitally has skyrocketed from about 0.8 percent in 1986 to 94 percent in 2007, a study finds. By 2007, the same analysis reveals, video game consoles were doing 25 percent of the world?s computing, and cell phones were doing 6 percent (SN Online: 2/10/11).

Vanishing act? Methane, the predominant hydrocarbon produced by the BP blowout in 2010, has all but vanished from Gulf of Mexico waters ? presumably eaten up by marine bacteria. That hadn?t been expected for years (SN: 1/29/11, p. 11).

NIH gap? Among minority scientists applying for U.S. National Institutes of Health research grants, blacks alone face a substantially lower likelihood of being successful than whites, a study finds (SN Online: 8/18/11).

Dirty deeds? A network analysis of Enron e-mails reveals that electronic missives regarding dirty dealings tend to transpire through a sparse hub and spoke network, rather than a highly connected web (SN: 7/2/11, p. 9).

War air? U.S. soldiers in Iraq must contend with air that?s laden with heavy metals and lung-ravaging particles (SN: 4/23/11, p. 15).

Double threat? Amoebas appear to contaminate drinking-water systems around the world (SN: 2/26/11, p. 9).

Penguin harm? Scientists may be causing long-term harm to penguins by tagging their flippers with metal ID bands (SN: 2/12/11, p. 10).

Bandwagon rewards? Day traders who act in sync ? no matter the stock, or whether they are buying or selling ? make more money at the end of the day than their out-of-sync peers (SN Online: 3/14/11).

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ATOM & COSMOS

Not so fast, neutrinos

News of particles zipping along faster than light (SN: 10/22/11, p. 18) was met with universal skepticism ? including from the physicists in Italy who reported the results. But the Gran Sasso National Laboratory?s OPERA team hasn?t found any source of error that could explain how the neutrinos appeared to shave 60 nanoseconds off of light-speed travel time while covering the 730 kilometers from the CERN physics laboratory near Geneva to Gran Sasso.

Einstein?s special theory of relativity says such speeds shouldn?t be attainable. And even if they were, the neutrinos would have shed observable energy during flight, report physicists at Boston University (SN: 11/5/11, p. 10). Critics suggest that at the different locales gravity may have pulled on the clocks with different strengths, causing the timekeepers to tick at different rates. Or some of the particles in the neutrino bunches could have started the trip earlier than thought.

Faced with these criticisms, the OPERA team has used shorter, sharper pulses of particles to check the results. The researchers say the findings still stand, but other large neutrino projects plan to repeat the experiment. ? Devin Powell

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Still shining? Some of the universe?s first stars may still be shining in the Milky Way, 13.4 billion years after forming, disputing the prevailing view that early stars died out quickly (SN: 2/26/11, p. 18).

Boom, then?zoom Telescopes capture a white dwarf star going supernova just 21 million light-years away (SN: 9/24/11, p. 5).

Rocks of life? Life-related chemicals are found in nearly a dozen meteorites, the strongest evidence yet that space rocks contain the building blocks of DNA and could have delivered them to Earth (SN Online: 8/10/11).

Superhot solution? NASA?s Solar Dynamics Observatory spots fountainlike jets of hot gas that shoot into the sun?s outer atmosphere, possibly explaining why it is millions of degrees hotter than the solar surface (SN: 1/29/11, p. 12).

Good-bye shuttle? Three decades after the first launch, the space shuttle program ends its run (SN: 6/18/11, p. 20). NASA also announces its pick of designs for a heavy-lift rocket to take next-gen astronauts into space.

Solar doldrums? Scientists predict that the sunspot cycle that began in early 2008 will be the weakest in 200 years (SN: 3/26/11, p. 5). Studies also suggest that a period of reduced solar activity could help cool the climate (SN: 7/16/11, p. 12).

Exoplanet bonanza A bevy of exoplanets are added to the growing list, including the first confirmed rocky planet beyond the solar system (SN: 2/12/11, p. 12) and a planet with a radius 2.4 times larger than Earth?s parked firmly within its star?s life-friendly zone (SN: 12/31/11, p. 11).

Last words The Fermi National Accelerator Laboratory?s Tevatron shuts down after a quarter century (SN: 9/24/11, p. 22). Before the closing, scientists discover the Xi-sub-b particle, predicted by the standard model of particle physics (SN: 8/27/11, p. 14).

Lurking lakes? Europa?s chaotic surface features signal the presence of large pockets of liquid water tucked into the Jupiter moon?s rock-hard ice, scientists report (SN: 12/17/11, p. 5).

Fluid situation? Analyses of mineral data hint that Mars? ancient surface may have been cold and frigid, with fluids appearing only beneath the planet?s ruddy sands (SN: 12/3/11, p. 5).

Mercury close-up? NASA?s MESSENGER spacecraft returns the first images ever taken by a probe orbiting Mercury, showing parts of the south and north polar terrains (SN Online: 3/30/11).

Dark check? Astronomers looking at distortions of microwaves left over from the Big Bang independently confirm the existence of dark energy (SN: 8/13/11, p. 18).

Crabby flares? The Crab Nebula hurls gamma-ray flares more energetic and five times brighter than any previously recorded, challenging theories about how the heavens accelerate charged particles (SN: 6/4/11, p. 10).

Crash course? The Genesis probe finds that, compared with the sun, the Earth is enriched in two types of oxygen and one of nitrogen (SN: 7/16/11, p. 5).

Superdupernova? A new class of supernovas emit much of their light at ultraviolet wavelengths and show no traces of hydrogen (SN: 7/2/11, p. 10).

Probe payoff? Gravity Probe?B confirms that the Earth drags spacetime as it rotates, an effect known as ?frame dragging? that is predicted by Einstein?s general theory of relativity (SN: 5/21/11, p. 5).

Hints of the Higgs Two experiments at the Large Hadron Collider find hints of the elusive Higgs boson, the last missing piece in particle physics? standard model (SN: 12/31/11, p. 10).

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NUTRITION

The value of vitamin D

The simmering debate over vitamin D came to a boil as the scientific organization representing hormone experts embraced daily recommendations for the vitamin that far exceed those put forward in late 2010 by a U.S. Institute of Medicine panel. The Endocrine Society asserted in July that people need two to three times as much vitamin D as the IOM had recommended (SN: 7/16/11, p. 22). The IOM daily levels top out at 600 to 800 international units for most people, the amount found in many multivitamins.

In calling for substantially more D, the endocrinologists cited widespread deficiency in all age groups and pointed out that very few foods naturally contain the vitamin.

A torrent of recent studies have linked vitamin D deficiency ? particularly at northern latitudes ? with heart disease, cancer, infections, asthma, preterm births, high blood pressure and, among the elderly, difficulty with mental tasks. Two trials now in progress in the United States and New Zealand may clarify the vitamin?s health-giving potential. But results are still several years off. ?Nathan Seppa

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Scant B12? Studies in the elderly link impairments of memory and reasoning with vitamin B12 deficiency. And brain scans show that people lacking B12 are more likely to have shrinkage of brain tissue and vascular damage (SN Online: 9/27/11).

Dietary details? An analysis assigning pounds of weight gain to foods finds that fries, sodas and several other guilty pleasures are among the worst waist expanders (SN: 7/30/11, p. 10).

Yogurt letdown? Eating yogurt doesn?t lead to long-lasting changes in a person?s mix of intestinal microbes (SN: 11/19/11, p. 18).

On the?mind? Obesity subtly diminishes memory and other features of thinking and reasoning even among seemingly healthy people, possibly by damaging the wiring that links the brain?s info-processing regions (SN: 4/23/11, p. 8).

Brainy sabotage? Obese people?s brains respond to food as if the body were hungry even when it isn?t, suggesting dieters may be on the losing side of a battle with neural centers that promote eating (SN: 10/22/11, p. 16).

Chocolate diet? Compounds in chocolate can ratchet down digestive enzymes that the body relies on to absorb and use fats and carbohydrates (SN Online: 5/9/11).

Saffron surprise Tests show that saffron can stifle liver cancer in rats (SN: 10/8/11, p. 14).

Blueberry boon Heart-healthy compounds found in blueberries limit the buildup of fat in mouse cells (SN Online: 4/20/11).

Dioxin flare-up? Frying at high temperatures can trigger the development of potentially toxic dioxins and furans in food (SN Online: 5/9/11).

Cough for quality Sensor molecules found in the human throat latch onto a chemical in superior olive oils, providing a scientific basis for the age-old custom of rating superlative oils on a scale of one, two or three coughs (SN Online: 1/18/11).

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MOLECULES

Molecular muscle does the job

Chemists often wish they could reach into a test tube and physically force a chemical reaction ? and now they?ve come pretty darn close. In a feat of molecular arm-twisting, researchers attached polymer chains to an extremely stable ring-shaped molecule and tore it in two (SN Online: 9/15/11). The new approach split the triazole ring, a compound found in many drugs and fungus-fighting chemicals, into its molecular building blocks, reversing the reaction that brought the ring together.

?It?s a way to almost literally put your hands on molecules and twist them or turn them in whatever way you want,? says Christopher Bielawski of the University of Texas at Austin, who led the research. Chemists often use heat to break compounds apart, but the approach can yield a variety of molecular pieces. And heat and other chemical tricks don?t work on the triazole ring, because it is too tough.

Bielawski and his students attached chains to opposite sides of the rings in solution and then inserted an ultrasound probe. The probe generated imploding bubbles, creating tiny pockets of suction that yanked on the polymer chains and tore open the rings. The technique reverses a reaction that was thought to go in only one direction, suggesting a new means for strong-arming other molecules into interesting new chemistry.

?This work is going to have a big impact,? says Virgil Percec of the University of Pennsylvania. ?It opens the door to unexpected new opportunities.? ? Rachel Ehrenberg

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Timely boom? By reining in a supersensitive explosive with good old-fashioned TNT, chemists have created a new crystal that can be stored and transported safely and then quickly converted to an active, superexplosive form (SN: 10/22/11, p. 10).

Absent interface? About a quarter of the molecules in water?s superthin surface layer can?t decide whether to be liquid or gas, but the ambiguity doesn?t affect the water below (SN: 7/2/11, p. 13).

Table gets flex? The atomic weights of 10 chemical elements in the periodic table are listed as ranges rather than single numbers, the first phase in an overhaul of almost every element in the table (SN: 1/29/11, p. 5).

Microbial work-around Researchers discover the ?methylaspartate cycle,? a means for synthesizing cellular building blocks cobbled together by salt-loving microbes (SN: 2/12/11, p. 14).

High blocker? Modifying the active ingredient in marijuana, THC, may allow researchers to quash the high that THC produces. The dopey sensation is an unwanted side effect for some people who use marijuana for its medical effects (SN Online: 4/24/11).

Green flame fighters Flexible coatings mere billionths of a meter thick keep cotton clothing from going up in flames and plastic foam from melting ? and they?re safer than the toxic flame retardants currently in use (SN: 9/24/11, p. 17).

Bottom up? With the help of template molecules, scientists manage to string small biologically important molecules together into larger, ringed structures (SN: 1/29/11, p. 16).

DEET?s deets? The repellent works its magic from afar by gumming up insects? sniffing machinery (SN: 10/22/11, p. 10).

Lab relief? Chemists have synthesized a pain-relieving extract, called conolidine, from the bark of a tropical shrub, paving the way for new drugs that lack the unwanted side effects of many opiate-based meds (SN Online: 5/23/11).

One poison? A type of caterpillar makes cyanide via the same cellular machinery as its host plant, the first known example of organisms from different kingdoms evolving the same biochemical treachery (SN: 5/7/11, p. 11).

Python elixir? A mix of fatty acid compounds identified in pythons can spur an exercise-like boost in the size of mouse hearts (SN: 12/3/11, p. 12).

Plastic isn?t over? A new polymer can be heated and reconfigured into complex shapes without losing its strength, meaning broken bits can be repurposed
(SN: 12/17/11, p. 8).

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ENVIRONMENT

Arctic warming signs

Climatologists pointing to the Arctic as the leading baro?meter of global change have plenty of new evidence that wholesale warming is under way. Observational data indicate that the region?s air, soils and water have warmed substantially since 2006, suggesting that the climate has established a ?new normal? (SN Online: 12/2/11). Among the symptoms: An anomalous pool of freshwater (27 meters deep in places) fed by inland meltwater has been found floating atop Arctic Ocean seawater (SN Online: 4/5/11). Erosion is also up across the Arctic, with area coastlines retreating on average by a half-meter per year (SN: 5/21/11, p. 13).

This year?s summer sea ice extent, a common marker for how bad things are getting, either approached or matched 2007?s record low, depending on which data scientists use (SN Online: 9/14/11; SN Online: 10/6/11). And computer projections by 19 different global climate programs indicate that relatively deep waters around Greenland will probably warm over the next 90 years at double the rate of deep water globally. The projected impact: Coastal glaciers will melt faster than had been anticipated ? largely from below (SN Online: 7/6/11). ? Janet Raloff

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Supercyclones? A cloud of air pollution over northern India and surrounding regions has doubled ? and occasionally tripled ? the intensity of late spring cyclones in the Arabian Sea during the last three decades (SN: 12/17/11, p. 13).

Up and up? Cores taken from North Carolina sediment reveal that sea levels began rising precipitously in the late 19th century and have since tripled the rate of climb seen at any time in the last two millennia (SN: 7/16/11, p. 13).

IQ dropper? Children exposed in the womb to substantial levels of neurotoxic pesticides have lower IQs by the time they enter school than do kids with virtually no exposure, three studies find (SN: 5/21/11, p. 15).

Clothing dangers? Plastic fibers from polyester or synthetic fabrics foul coastal environments worldwide (SN Online: 9/14/11).

BPA revisited? Two new studies link feminized behaviors in adult male mice with exposure during development to the plastics chemical bisphenol A (SN: 7/30/11, p. 16). Another study shows that BPA can trigger hormone-responsive gene changes in people (SN Online: 8/27/11).

Germy skies? Microbes aloft in the atmosphere can catalyze ice nucleation, leading to cloud formation and bad weather conditions (SN: 6/18/11, p. 12).

Immune weeds? Research uncovers a rapid rise in herbicide-resistant weeds and increasing numbers of weeds immune to multiple herbicides (SN: 7/2/11, p. 5).

Polar ozone? Record ozone depletion over the Arctic rivals what was observed in the Antarctic when holes in the protective atmospheric layer first appeared there (SN: 11/19/11, p. 11). To the south, scientists see signs of recovery in the Antarctic ozone hole more than a decade earlier than expected (SN: 6/4/11, p. 15).

Missing fish? New studies suggest that ecologically valuable predatory fish are rapidly disappearing (SN: 4/9/11, p. 28).

Noise woes? Sonar exercises at an under?water test range led beaked whales to flee the area. Tagged whales exposed to sounds at about 140 decibels stopped hunting and swam toward the surface (SN: 4/23/11, p. 16).

Fishy return? Within 14 years of a Mexican marine park in the Gulf of California prohibiting fishing, the total mass of its denizens more than quintupled, a sign of habitat protection?s potential (SN: 9/24/11, p. 14).

Acid ignorance? Juvenile clown fish raised in water mimicking the predicted acidifying chemistry of future oceans appear willing to swim toward a predator-packed reef (SN: 7/2/11, p. 12).

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GENES & CELLS

Boons and busts via gut microbes

Studying the secret lives of bacteria living in human intestines has yielded some unexpected finds. One study suggests that most humans have one of three different combinations of friendly microbes (SN: 5/21/11, p. 14), and another reveals that people?s mix of microbes depends heavily on diet. Changing the ratios of nutrients consumed tweaks the composition of the microbial populations in the guts of mice carrying human bacteria, scientists find (SN Online: 5/19/11).

Knowing just how to alter the diet to achieve the right mix of microbes may be important for good health, both physical and mental. At least one type of friendly bacteria can send signals from the intestines through the vagus nerve in the neck to influence brain chemistry and change behavior in mice, researchers report (SN: 10/8/11, p. 9). Gut microbes have also been found to convert a type of fat found in meat and dairy products into an artery-clogging chemical, and intestinal microbes may trigger multiple sclerosis, an immune system disorder in which the body attacks its own nerve cells (SN: 12/3/11, p. 11).

But even if some bacteria break hearts or turn a body against itself, organisms of all sorts would be in big trouble without them. Mice given antibiotics that kill off their microbes can?t fight the flu as well mice that don?t take the drugs (SN: 4/9/11, p. 14). ?Tina Hesman Saey

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Bright cats? Kittens are engineered with a gene for an antiviral protein that scientists hope will help combat feline immunodeficiency virus (SN: 10/22/11, p. 9). The cats also get a gene that makes them glow.

Beneficial liaisons? Humans may have acquired important immune system genes via liaisons with extinct hominid cousins, the Neandertals and Denisovans (SN: 10/8/11, p. 13).

Healthy aging? After mining the DNA of a woman who lived to age 115, researchers conclude that she did not lack genetic variants predisposing her to heart disease and other aging-related illnesses (SN: 11/5/11, p. 9).

Genetic loophole? The occasional switch of a chemical unit in RNA to a slightly different form can cause a cell?s protein-building machinery to roll right through a molecular stop sign, a find that violates the central dogma of genetics (SN: 7/16/11, p. 8).

More than squirm? A new system, named COLBERT for ?Controlling Locomotion and Behavior in Real Time,? allows researchers to commandeer tiny worms and pick apart behavior cell by cell (SN: 2/12/11, p. 14).

Missing DNA, bigger brains Humans may have developed bigger brains, spineless penises and other traits after losing 510 chunks of DNA, a study suggests (SN: 4/9/11, p. 15).

Gene fix? A new gene therapy allows direct fixing of DNA. With molecular editors called zinc finger nucleases, scientists correct a mutation in mice that leads to hemophilia (SN: 7/30/11, p. 9).

Superbug from drugs Antibiotics and vaccines helped shape the evolution of a nasty strain of pneumonia-causing bacteria, scientists find (SN: 2/26/11, p. 16).

Lager mystery? Scientists identify a missing ancestor of yeast used in cold-brewed beer (SN: 9/24/11, p. 16).

Stem cell steps? The body?s immune system may attack lab-made stem cells, a study in mice finds, a possible hurdle to using such cells to replace damaged tissue (SN: 6/4/11, p. 13). Another study uses human eggs to reprogram adult cells to a primitive embryonic-like state, but they have extra chromosome sets (SN: 11/5/11, p. 8).

Burn that fat? Mice lacking a protein that responds to the hunger-promoting hormone ghrelin burn more energy in their brown fat than other mice, hinting at a way to fight obesity (SN: 1/15/11, p. 9).

To the heart? With a little help from cellular reprogramming factors, skin cells are converted into beating heart cells (SN: 2/26/11, p. 16). With some prodding, stem cells lining the outside of the heart can also form new heart cells (SN: 7/16/11, p. 9).

Pylori trouble? A bacterial bad guy responsible for causing ulcers and stomach cancer, Helicobacter pylori, may help trigger Parkinson?s disease (SN: 6/18/11, p. 18).

Brain healing? Blocking newborn nerve cell formation in mice prevents the animals from learning and remembering in a maze after brain injury, suggesting the newborn cells may help the brain heal (SN: 4/23/11, p. 10).

Gland growth? Japanese researchers grow for the first time a mouse pituitary gland from embryonic stem cells in a lab dish, a first step toward replacement glands for people (SN: 12/31/11, p. 15).

Electric eye? Cells in a tadpole?s gut manipulated to take on specific electrical properties develop into an eye, a major advance toward regenerating complex organs and limbs (SN: 12/31/11, p. 5).

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MATTER & ENERGY

Quantum theory gets physical

Reality can be understood not only in terms of the flow of energy, but also in terms of the flow of information. So says a team of physicists with a new take on quantum theory (SN: 8/13/11, p. 12). This theory, which explains how matter behaves at the atomic scale, is built on abstract mathematical formulations that seem to defy common sense. But the new take begins with intuitive principles connected to the physical world.

At the idea?s core is a postulate called ?purification.? In simplest terms, purification means that you can know everything there is to know about something even if you don?t know everything about its parts. Using this postulate and five axioms drawn from information theory, the researchers have derived the basic mathematical framework of quantum mechanics. The framework also predicts phenomena routinely observed in the lab ? including entanglement, Einstein?s ?spooky action at a distance.?

This recent approach to quantum theory is part of a larger movement, inspired by the late physicist John Wheeler, to try to recast the explanation of the universe in terms of information. Proponents speculate that their ideas could ultimately solve one of the grandest problems in physics itself: how to unite quantum mechanics and gravity. ?Devin Powell

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Cosmic mimics? Simulations suggest that time travel is impossible in a metamaterial universe (SN: 5/7/11, p. 12), but riding a spacetime bubble could allow travel at up to one-quarter light speed (SN Online: 8/21/11).

Big-time cloaking? Teams use carpet cloaks to hide 3-D objects big enough to see, moving invisibility beyond the microscopic (SN: 2/26/11, p. 12). Physicists also find ways to hide events in time (SN: 8/13/11, p. 12) and to shield objects from detection by visible light (SN: 8/27/11, p. 16) and sound waves (SN Online: 6/30/11).

The next graphene Scientists grow atom-thin sheets of silicon, with a structure similar to that of graphene (SN: 4/23/11, p. 14).

Sexual fireworks? A mouse egg explosively releases zinc atoms just after fertilization, outbursts that appear to jump-start embryonic development (SN: 6/4/11, p. 12).

Wave of reality? The fuzzy quantum shape that describes the speed or location of a single particle, its ?wave function,? is directly measured in the lab (SN: 7/16/11, p. 14).

Atomtronics Physicists choreo?graph atoms in an ultracold gas to flow as a controllable current, a step toward building the world?s first ?atomtronic? device (SN: 3/12/11, p. 5).

Hydrogen head shot? The lightest atom on Earth is directly imaged for the first time (SN: 3/12/11, p. 13).

Magnetricity? A current of ?magnetricity? is created, as north and south magnetic poles split and move independently (SN: 3/12/11, p. 13).

Screwy symmetry? A new form of symmetry called ?rotational-reversal? symmetry is discovered (SN: 5/7/11, p. 9).

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BODY & BRAIN

Sifting through autism?s tangled web

Each person with an autism spectrum disorder has a different disease, yet some commonalities exist, a flurry of studies reveals (SN: 8/13/11, p. 20). Though the finds don?t point to a clear cause or a cure, they inch researchers closer to a deeper understanding of the baffling disorders.

By sifting through genetic differences in a large group of children, researchers find numerous changes that could contribute to autism spectrum disorder (SN Online: 6/8/11). Screening more than 1,000 families, including parents and unaffected siblings, reveals duplicated and missing portions of DNA. Such changes may account for 5 to 8 percent of autism cases.

Other research has focused on gene and protein activity in a person with autism. Hundreds of genes behave differently in the brains of people with autism (SN: 6/18/11, p. 5), and many of these genes are involved in nerve cell communication. Proteins that govern nerve cell behavior are probably important for the disorders too: Scientists have discovered new relationships between some key autism-related proteins and over 500 other proteins.

Although this laundry list of biochemical changes seems dauntingly complex, the results still represent a flood of progress in trying to understand autism, says child psychiatrist and geneticist Matthew State of Yale University School of Medicine. ?These are all, in their own way, making a chink in the armor.? ?Laura Sanders

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Against Alzheimer?s? Data link antidepressants to less of the ominous brain plaque associated with Alzheimer?s (SN: 9/10/11, p. 5). Other studies scrutinize A-beta?s role in the disease.

Stent risk? Brain stents used in patients at risk of stroke may do more harm than good: A study finds rates of death and stroke are higher among patients who receive the device than those who receive an aggressive course of medications alone (SN: 10/8/11, p. 14).

Malaria vaccine? African children who received the first vaccine against malaria to undergo wide-scale testing are about half as likely to come down with the disease over a 14-month period as those who didn?t receive the vaccine (SN Online: 10/19/11).

HPV for men? A study of men in North and South America finds that half carry human papillomavirus, known for causing cervical cancer in women (SN: 3/26/11, p. 12). The U.S. Advisory Committee on Immunization Practices recommends that preteen boys receive the HPV vaccine (SN Online: 10/26/11).

Ch-ch-ch-changes By charting the brain?s genetic activity from before birth to old age, two new studies reveal that all human brains use pretty much the same genes in the same way and that the brain continually remodels itself in predictable ways throughout life (SN: 11/19/11, p. 5).

Dream deciphered The contents of a person?s dream are revealed by a brain scan for the first time. Monitoring the brain of a man who has unusual control over his dreaming brings researchers closer to understanding how the brain spins its nightly yarns (SN: 12/17/11, p. 10).

Cell phone vibes A 50-minute call boosts activity in brain regions near the ear where a cell phone is located, research suggests (SN: 3/26/11, p. 13).

Brain on z?s? Electrodes implanted in the brains of rats kept up four hours past their usual bedtime show that some cells go to sleep while others remain active (SN: 5/21/11, p. 9). Two other studies in fruit flies confirm that sleep plays a central role in solidifying memories and preparing the brain for new learning (SN Online: 6/23/11).

Armadillo infector? People infected with leprosy in the United States often have the same previously unknown strain of the microbe Mycobacterium leprae that is carried by armadillos, strengthening a long-held assumption that armadillos can infect people directly (SN: 5/21/11, p. 9).

To the brain? A single drug might create a temporary opening in the blood-brain barrier, allowing for new medicines to treat neurological diseases (SN Online: 9/13/11).

Heart tracker? Studies suggest that a blood compound called cardiac troponin T could serve as a risk indicator for heart disease (SN: 1/15/11, p. 14).

NSAID risk? The popular anti-inflammatory drugs ibuprofen and naproxen could contribute to the risk of miscarriage when taken early in pregnancy, researchers find (SN: 11/5/11, p. 14).

Degrees of good? A study suggests that levels of HDL, the good cholesterol, may not be the most important factor in protecting against clogged arteries and cardiovascular disease; HDL?s efficiency at removing fats is a better predictor of who will develop heart disease (SN: 2/12/11, p. 16).

XMRV exonerated? A study fails to confirm a link between chronic fatigue syndrome and a family of viruses that includes XMRV. Nine labs ? including the two that originally identified the connection ? could not reliably detect the viruses in blood cells from patients with the mysterious and controversial condition (SN: 10/22/11, p. 5).

New tubes? Blood vessels grown using human cells as factories pass a test in baboons and dogs, suggesting that natural-tissue vessels could be produced for kidney dialysis or heart bypass surgery (SN: 2/26/11, p. 11).

Ketamine explained? The anesthetic ketamine fights depression by quickly boosting levels of a brain compound that has been linked to the condition (SN: 7/16/11, p. 17).

Preterm aftereffects? Infants born prematurely face a higher risk of dying in early adulthood than babies born at full term, scientists report. The higher mortality risk also shows up when the babies are preschool age (SN Online: 9/20/11).

Two brain slots? Like side-by-side computer RAM cards, the left and the right hemispheres of the brain store information separately, helping explain why people can remember only a handful of objects at one time (SN: 7/30/11, p. 10).

Rerouted for feeling Amputees whose sense of touch was rerouted from their missing limbs view their prosthetics as part of the body (SN: 2/26/11, p. 10).

Apnea-dementia link A study of women 65 and older finds that those with seriously disordered breathing have an increased risk of developing mild cognitive impairment or dementia in subsequent years (SN: 9/10/11, p. 16).

Immune booster calms? An immune protein once pursued as a treatment to rev up the body?s defenses, interleukin-2, may be able to halt or reverse aberrant immune reactions where standard treatments have failed (SN Online: 11/30/11).

Breast cancer drug? A drug called exemestane, which inhibits the manufacture of estrogen, can lower the likelihood of breast cancer among healthy women at risk of developing the disease (SN: 7/2/11, p. 16).

Supermemory? People who can remember every day of their lives in detail have more bulk in certain brain regions, one of which has been linked to obsessive-compulsive disorder (SN: 12/3/11, p. 9).

Hypnosis confirmed? A glassy gaze that jumps around in bizarre patterns may be a foolproof sign of a hypnotic trance, researchers report (SN: 12/17/11, p. 10).

Between the ears The high-pitched ringing, squealing, hissing, clicking, roaring, buzzing or whistling in the ears that can drive tinnitus sufferers crazy may be a by-product of the brain turning up the volume to cope with subtle hearing loss (SN: 11/5/11, p. 14).

No fear here? A rare genetic disease that destroyed a middle-aged woman?s amygdala made her immune to fear, researchers find (SN: 1/15/11, p. 14).

_____________________
LIFE

Multicellular life from a test tube

In less than two months, yeast in a test tube evolved from single-celled life to bristly multicellular structures. The new, snowflakelike forms act like multicellular organisms, reproducing by splitting when they reach large sizes and evolving further in response to harsh conditions, William Ratcliff of the University of Minnesota, Twin Cities reported in Norman, Okla., at the Evolution 2011 meeting (SN: 7/16/11, p. 11).

To create pressure to evolve in the experiment, Ratcliff and his colleagues subjected tubes of yeast in liquid to a daily ordeal: a mild spin in a centrifuge and then removal of all but the sludge with the heaviest yeast. Yeasts reproduce by budding, and cells that continued clinging to their daughter buds after cell division probably landed in the sludge and survived. Under pressure from these daily tosses, yeast lineages started holding onto buds that had themselves budded, creating multicelled spiky shapes.

Additional data revealed that the snowflakes amount to more than one-celled microbes known to cluster or form films, suggesting that multicellularity may arise more readily than previously thought, the researchers argue. ?Susan Milius

***

Irish bears? DNA analysis suggests that all of today?s polar bears can trace their maternal ancestry to a female brown bear in Ireland. Polar bears interbred with brown bears in or near Ireland between 20,000 and 50,000 years ago (SN: 7/30/11, p. 5).

Unexpected farmers? A social amoeba, Dictyostelium discoideum, practices simple agriculture in the form of bacterial husbandry (SN: 2/12/11, p. 11).

Gone fishing? Orangutans in Borneo dine on stranded fish, occasionally jabbing at them with sticks to get them to flop out of the water (SN: 5/7/11, p. 16).

Elephants divided? A genetic analysis of elephants and their extinct relatives shows that forest-dwelling African elephants are a separate species from Africa?s savanna elephants (SN: 1/15/11, p. 16).

Eyespots have it? Research reveals that more peacock eyespots might not always win a mate, but peahens appear to expect a threshold number before they are willing to get their game on (SN: 5/21/11, p. 10).

Cycad rewrite? Today?s cycads, once touted as survivors from dinosaur times, turn out to be mostly recent species, diversifying from an ancestor that flourished around 12 million years ago (SN Online: 10/21/11).

Baboon boss stress Top-ranking male baboons generate surprisingly high levels of stress hormones, a sign that these primates pay a cost to be the boss (SN: 8/13/11, p. 11).

Fungus killer? A systematic test with initially healthy little brown bats shows that the fungus Geomyces destructans is the primary cause of white-nose syndrome (SN: 12/3/11, p. 12).

Plant rewards? In one of the biggest underground markets on the planet ? nutrient trading between plant roots and fungi ? good suppliers get rewards and bad ones get less business, researchers find (SN: 9/10/11, p. 15).

Diving spiders? The air bubbles carried by Eurasian diving bell spiders can act as physical gills, pulling oxygen from the water (SN: 7/2/11, p. 14).

Connecticut cat? A cougar took a 2,000-mile journey from the Black Hills of South Dakota to the green lawns of southern New England (SN: 8/27/11, p. 5).

Mice boom? A syndrome that has wiped out swaths of aspens across the western United States is linked to an increase in disease-carrying deer mice (SN: 1/29/11, p. 15).

Evolutionary dawdling? The last common ancestor of all living animals probably arose nearly 800 million years ago, scientists report ? suggesting animals started evolving roughly 200 million years before what?s known as the Cambrian Explosion (SN: 12/31/11, p. 12).

Electric sensibilities? The dolphin is the first true mammal found to detect electrical fields, via organs thought to be long-lost whiskers (SN: 8/27/11, p. 12).

Stress goes on? Not only do zebra finch nestlings dosed with stress hormones tend to die early, but the nestlings also pass the risk of a shortened life span on to future long-term mating partners (SN: 9/24/11, p. 14).

Engineered release? Lab mosquitoes infected with a bacterium that renders them unlikely to pass along dengue mate well enough with wild populations to make the bacteria widespread, field tests in towns in Australia reveal (SN Online: 8/24/11).

_____________________
TECHNOLOGY

Epidermal electronics

Scientists have created an ultrathin electronic device that puckers, stretches, wrinkles and bends just like human skin (SN: 9/10/11, p. 10). This flexible patch could one day allow the human body to enter the digital world, enabling Internet browsing without the mouse or communication without words. The patch?s electronics form a flexible net of wavy S-shaped curves that can stretch in any direction and still work. Two supple polymer sheets sandwich the business layer of the gadget and the whole thing sits on a film that sticks to skin.

Developed as less obtrusive health monitors, versions of the device have been used to track vital signs. In a more lighthearted demonstration, the patch analyzed a person?s throat muscles as directions were spoken to move a cursor in a computer game. Mixing and matching electronic components could lead to a variety of jobs, says study coauthor John Rogers of the University of Illinois at Urbana-Champaign. ?Creative folks out there will think of things we haven?t even contemplated.? ? Laura Sanders

***

Tiny test drive? A miniature roadster with four molecular wheels and a carbon-based frame rolls across a surface when zapped with electricity (SN: 12/17/11, p. 8).

Virtual princess? A team unveils a 3-D holographic video that plays at 15 frames per second, displaying a real-time projection of a grad student dressed as Princess Leia (SN Online: 1/26/11).

No batteries? A prototype sensor produces enough electrical charge when flexed mechanically to transmit a wireless signal several meters. Such sensors may help monitor the strength of a bridge, for example, while getting power from the vibrations of trucks rumbling overhead (SN: 7/30/11, p. 18).

Do the twist? A new way to mold radio waves into spirals could let multiple radio stations broadcast at the same frequency (SN: 8/27/11, p. 16).

Built for speed? A robot that curls itself into a loop and peels out at speeds faster than half a meter per second has been created (SN: 5/21/11, p. 10).

?Stiltskin science? In a feat that puts Rumpelstiltskin to shame, researchers spin a multitude of hi-tech materials into superfine nano?wire bundles 1,000-plus meters long (SN: 7/16/11, p. 16).

Fix thyself? A new lithium-ion battery capable of healing itself may improve the life span and safety of today?s energy-storage technologies (SN Online: 2/21/11).

Follow the flies? Mimicking how some developing nerve cells in flies pick a leader has led to a computer algorithm that could make wireless sensor networks more efficient (SN: 2/12/11, p. 13).

_____________________
EARTH

Warming slowdown

The planet?s overall temperature has been climbing upward, but that trend stalled during the early 2000s ? and now scientists think they can explain why. Several studies suggest that tiny sulfur-rich particles called aerosols, which shield the Earth from the sun?s incoming rays, are to blame.

Some of those particles come from volcanic eruptions, such as the Soufri?re Hills volcano in Montserrat that has been puttering along since 1995. Although such eruptions aren?t as dramatic as the 1991 eruption of Mount Pinatubo in the Philippines, which cooled the whole planet for several years, the aerosols from several small volcanoes are enough to add up to a cooling influence (SN: 8/13/11, p. 5). Also playing a role are coal-burning power plants, particularly in Asia. Sulfur particles coming from the plants mostly counterbalanced the warming produced by their carbon dioxide emissions (SN: 7/30/11, p. 17).

Overall, the buildup of carbon dioxide is expected to keep sending temperatures upward ? a trend observed by three independent research teams and confirmed this year by yet another analysis performed by the Berkeley Earth Surface Temperature group. ?Alexandra Witze

***

Riches from on high? Many of the precious metals mined today were delivered via a bombardment of stony meteorites that pummeled the Earth and left craters on the moon billions of years ago (SN: 10/8/11, p. 11).

Chiseled from below Molten material rising from beneath is chiseling chunks of rock off the bottom of the Colorado Plateau, possibly explaining why this area has lifted upward over millions of years (SN: 5/21/11, p. 12).

Record high tie? Analyses from NASA and the National Oceanic and Atmospheric Administration rate 2010 as tied with 2005 for the hottest year on record, followed closely by 1998. Others rank 2010 as the second hottest (SN: 2/12/11, p. 17).

Waistline growth? Ice melting off Greenland and Antarctica has changed the shape of the Earth, making it more bulgy at the equator, scientists find (SN: 7/16/11, p. 13).

Tipping point? An analysis reveals that a small change in rainfall or other factors can cause an ecosystem to switch abruptly between forest and savanna (SN: 11/5/11, p. 5).

Climate meddlers? Humans removing trees to work the land put nearly 350 billion metric tons of carbon into the atmosphere by 1850, researchers suggest (SN: 4/23/11, p. 17). Another team argues that Christopher Columbus and other New World explorers may have set off a series of events contributing to Europe?s Little Ice Age (SN: 11/5/11, p. 12).

Polar flip? The occasional swapping of the north and south magnetic poles may be tied to plate tectonics; when landmasses have bunched together, Earth?s magnetic field has begun flipping soon after (SN: 11/19/11, p. 9).

Quick colonizers? Fossils dating to 530 million years ago suggest that Earth?s first animals colonized fresh?water earlier than thought, soon after diverse forms appeared in marine habitats (SN: 6/4/11, p. 9).

In clusters? Researchers argue that Japan?s catastrophic March earthquake was part of a spasm of quakes, the second spasm since 1900 (SN: 5/7/11, p. 5).

Early meat-eater Researchers uncover a fossil of a pint-sized meat-eater named Eodromaeus, or ?dawn runner?, that dates to 230 million years ago, the dinosaurs? earliest days (SN: 2/12/11, p. 10).

Extinction causes? New studies suggest that gassy volcanic eruptions (SN: 1/15/11, p. 12) and acidifying oceans (SN: 10/8/11, p. 10) could have contributed to the mass extinction at the end of the Permian period, some 250 million years ago.

Big blowup? Geologists find evidence for one of the biggest volcanic eruptions ever, in southern Java 21 million years ago (SN Online: 8/6/11).

_____________________
HUMANS

Asia takes a bow

Often overlooked as a geographic player in human evolution, Asia has stepped into the scientific spotlight. New comparisons of ancient and modern DNA indicate that Stone Age humans migrated to Asia in two stages.

At least 44,000 years ago, initial arrivals in Southeast Asia interbred with a humanlike population known as Denisovans that apparently had spread southward from Siberia. Denisovans contributed a portion of genes to living New Guineans (SN: 1/15/11, p. 10), Australian Aborigines and groups on nearby islands (SN: 11/5/11, p. 13). A second human influx gave rise to today?s East Asians, with no Denisovan dalliances, starting between 38,000 and 25,000 years ago, geneticist Morten Rasmussen of the Natural History Museum of Denmark in Copenhagen and his colleagues find. The work builds on previous genetic evidence that Homo sapiens interbred with Neandertals in West Asia before heading east.

Another study raises the possibility that early members of the genus Homo evolved in Asia and then trekked to Africa, not vice versa as many scientists have assumed (SN: 7/2/11/, p. 8). Homo erectus inhabited a West Asian site called Dmanisi from 1.85 million to 1.77 million years ago, at the same time or slightly before the earliest evidence for the species in Africa, researchers report. ?Bruce Bower

***

Ape to human? Skeletal traits in the proposed hominid species Australopithecus sediba suggest that the species served as an evolutionary bridge from apelike ancestors to the Homo genus (SN: 10/22/11, p. 14).

Fast track? Modern humans reached Arabia?s eastern edge as early as 125,000 years ago, 65,000 years earlier than generally accepted migrations out of Africa, scientists report (SN: 2/26/11, p. 5).

Hormone?s dark side The brain-altering substance oxytocin amplifies whatever social proclivities a person already possesses, encouraging a trusting person to be more trusting but a suspicious person to be more uncooperative and hostile (SN: 2/26/11, p. 15).

Clovis question? Stone tools and flaky rock bits in Texas date to between 13,200 and 15,500 years ago, adding to evidence that the Clovis people were not the first in the Americas (SN: 4/23/11, p. 12).

Easy geometry? Munduruc? villagers of the Amazon grasp abstract geometric principles despite having no formal math education, suggesting geometry is innate or learned through general experience (SN: 6/18/11, p. 16).

Built to walk? A 3.2-million-year-old fossil from East Africa suggests Australopithecus afarensis, best known from the partial skeleton ?Lucy,? had stiff foot arches like those of people today, a sign of a two-legged stride (SN: 3/12/11, p. 8).

Oldest axes? An East African site yields the oldest known stone hand axes, dating to 1.76 million years ago (SN: 10/8/11, p. 12).

Filled belly? A 5,300-year-old mummy known as ?the Iceman? dined on wild goat before his death in the Italian Alps (SN: 9/24/11, p. 8).

Write stuff?? Writing down test-related worries before an exam appears to dislodge concerns and lead to higher achievement among high school and college students (SN: 2/12/11, p. 9).

Paint shop? In a cave along South Africa?s coast, Stone Age humans made a red-hued paint that they stored in abalone shells and possibly used to decorate themselves or their belongings (SN: 11/19/11, p. 16).

No poker face? People can tell whether a chimp acts dominantly and is physically active just by looking at a picture of its expressionless mug. The ability to discern personality traits via facial structure may have evolved more than 7 million years ago, researchers argue (SN: 2/12/11, p. 8).

Share or stash? If they?ve worked together to get it, young kids share stuff equally. Adult chimps don?t mete out fair shares, suggesting sharing evolved in ancient human foraging groups (SN: 8/27/11, p. 10).

Source: http://www.sciencenews.org/view/feature/id/336959/title/2011_Science_News_of_the_Year

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