What Thawed the Last Ice Age?

Roughly 20,000 years ago the great ice sheets that buried much of Asia, Europe and North America stopped their creeping advance. Within a few hundred years sea levels in some places had risen by as much as 10 meters--more than if the ice sheet that still covers Greenland were to melt today. This freshwater flood filled the North Atlantic and also shut down the ocean currents that conveyed warmer water from equatorial regions northward. The equatorial heat warmed the precincts of Antarctica in the Southern Hemisphere instead, shrinking the fringing sea ice and changing the circumpolar winds. As a result--and for reasons that remain unexplained--the waters of the Southern Ocean may have begun to release carbon dioxide, enough to raise concentrations in the atmosphere by more than 100 parts per million over millennia--roughly equivalent to the rise in the last 200 years. That CO2 then warmed the globe, melting back the continental ice sheets and ushering in the current climate that enabled humanity to thrive.

Flame Retardants May Create Deadlier Fires

In one of the deadliest nightclub fires in American history, 100 people died at a rock concert in Rhode Island nearly a decade ago. But the biggest killer wasn't the flames; it was lethal gases released from burning sound-insulation foam and other plastics.

Infectious Selflessness: How an Ant Colony Becomes a Social Immune System

In the 2011 blockbuster thriller Contagion , a virus infects and kills 26 million people around the world. But even those who evade the virus are infected with something else: crippling fear . To contain the outbreak, the military imposes a quarantine. People stay indoors, refusing to interact with anyone outside their families. Touching anyone or anything becomes a risk, because the virus lingers everywhere. [More]


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Why Some Pain Relievers Cause Intense Itching

Millions of patients benefit from opioids such as morphine and codeine, but the pain relief they provide often comes with intense itching. In some cases, the irritation is so bad that patients will opt to cut back on painkillers. Now a study in the October 14 issue of Cell has found a possible explanation--the first step to creating drugs that will not make patients choose between experiencing itchiness and pain.

Fossil Free: Microbe Helps Convert Solar Power to Liquid Fuel

A new " bioreactor " could store electricity as liquid fuel with the help of a genetically engineered microbe and copious carbon dioxide. The idea--dubbed " electrofuels " by a federal agency funding the research--could offer electricity storage that would have the energy density of fuels such as gasoline. If it works, the hybrid bioelectric system would also offer a more efficient way of turning sunlight to fuel than growing plants and converting them into biofuel .

Microbial Mules: Scientists Experiment With Engineering Bacteria to Transport Nanoparticles and Drugs

Tiny robots that swim through our blood vessels attacking viruses and malignant cells have not quite crossed the line that separates science fiction from science--but there might be a way to jump-start their development. [More]


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Primeval Precipitation: What Fossil Imprints of Rain Reveal about Early Earth

Some 2.7 billion years ago in what is now Omdraaisvlei farm near Prieska, South Africa, a brief storm dropped mild rain on a new layer of ash laid down by a recent volcanic eruption (not unlike ash from the 2010 Eyjafjallajökull eruptio n in Iceland) forming tiny craters. Additional ash subsequently buried the craters and, over eons, hardened to become rock known as tuff. Closer to the present, other rainstorms eroded the overlying tuff, exposing a fossil record of raindrops from the Archean eon, and may now have revealed the density of early Earth's atmosphere.

Recommended: The Social Conquest of Earth

The Social Conquest of Earth [More]


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Power Plants: Could a Rechargeable Battery Be Made from Paper and Pulp By-Products?

Despite decades of predictions that a fully electronic, paperless society is almost upon us, we still live in a world populated with printed documents. This insatiable demand for plant cellulose –based writing and packaging materials may end up having a silver lining: a component for a new type of low-cost, Earth-friendly rechargeable battery . [More]


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Can Fast Reactors Speedily Solve Plutonium Problems?

The U.K. has nearly 100 metric tons of plutonium--dubbed " the element from hell " by some--that it doesn't know what to do with. The island nation does not need the potent powder to construct more nuclear weapons, and spends billions of British pounds to ensure that others don't steal it for that purpose. The unstable element, which will remain radioactive for millennia, is the residue of ill-fated efforts to recycle used nuclear fuel.

Something to Chew On: Healthier Hot Dogs Substitute Cellulose for Saturated Fats

Not all fats are created equal. Scientists have known since the 1950s that replacing saturated fats with unsaturated ones can have profound health benefits . Diets that are high in solid fats, such as butter and animal fat, lead to elevated risks of cardiovascular disease and high cholesterol. But it has been difficult to phase out saturated fats--not only are they are delicious, they are also important components of a food's structure. Without saturated fat, ice creams are just sugary liquids and a hot dog has the consistency of a pet’s chew toy.

How Packaged Food Makes Girls Hyper

The chemical bisphenol A, known as BPA, has become familiar in the past decade, notably to parents searching for BPA-free bottles for their infants. Animal studies have found that BPA, which resembles the sex hormone estrogen, harms health. The growing brain is an especially worrisome target: estrogen is known to be important in fetal brain development in rodents. Now a study suggests that prenatal, but not childhood, exposure to BPA is connected to anxiety, depression and difficulty controlling behaviors in three-year-olds, especially girls.

Shocking Pink: An Inexpensive Test for Chemical Weapon Attacks

It seems unlikely that the maker of hundred-million-dollar Hollywood blockbusters such as Armageddon and The Transformers could inspire scientists to develop an ultralow-cost tool for quickly sensing airborne chemical weapons . Yet one former University of Michigan at Ann Arbor (U.M.) researcher says his idea to use a nerve-gas antidote to create an inexpensive litmus paper–like nerve-gas sensor emerged shortly after watching The Rock on DVD a few years ago. [More]


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Produce Consumption Ups Eater's Looks

Fruit and veggies don’t just improve your diet--they could enhance your looks. A new study, done with primarily Caucasian subjects, finds that eating produce heightens red and yellow skin tones, which increases attractiveness. The work is in Public Library of Science ONE . [Ross D. Whitehead et al., " You Are What You Eat: Within-Subject Increases in Fruit and Vegetable Consumption Confer Beneficial Skin-Color Changes "]

Is "All of the Above" the Right Strategy for U.S. Energy? A Q&A with Steven Chu

President Obama has called for an "all of the above" energy strategy , ranging from taxpayer funding for electric vehicles to more drilling for oil and natural gas. The goal is to get a greater contribution from domestic renewable energy sources, such as the sun and wind, yet maintain cheap domestic energy from traditional fossil fuels.

The Liver: Helping Enzymes Help You!

Key concepts [More]


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New Gels Heal Themselves--and Maybe You

They’re called hydogels: Jell-O-like materials made of networks of long-chain molecules in water. And they’re as flexible as living tissue. But hydrogels could not recover from a cut--until now. Bioengineers at U.C. San Diego have made hydrogels that are self-healing in acidic conditions.

Search for Faster, Better Antidepressants Makes Progress (preview)

A young woman who calls herself blue­berryoctopus had been taking anti­depressants for three years, mostly for anxiety and panic attacks, when she recounted her struggles with them on the Web site Experience Project. She said she had spent a year on Paxil, one of the popular SSRIs (selective serotonin reuptake inhibitors), but finally stopped because it destroyed her sex drive. She switched to Xanax, an ­antianxiety drug , which brought back her libido but at the cost of renewed symptoms. Then Paxil again, then Lexapro (another SSRI), then Pristiq, a member of a related class of antidepressants, the SNRIs (serotonin and norepinephrine reuptake inhibitors). At the time of the post, she was on yet another SSRI, Zoloft, plus Wellbutrin (a cousin of SNRIs that affects the activity of dopamine as well as norepinephrine), which was intended to counteract the sexual side effects of Zoloft. “I don’t notice much of a difference with the Wellbutrin, but I’m on the lowest dose now,” she wrote. “I’m going back to my psychiatrist next week, so maybe he’ll up it. Who knows.”

Exercise Instantly Affects DNA

Maybe this will motivate you to work out. New research supports the idea that you don't need to spend hours at the gym everyday for your body to start feeling the positive effects of exercise. In fact, a single session on a stationary bike can affect your very DNA.

Structured Unlearning: Marijuana May Impair Memory via the Brain's Non-Firing Cells

In a 2006, season 2 episode of The Office entitled "Drug Testing," Dwight Schrute interrogates his fellow employees about the partially smoked joint he found in the parking lot. Dwight is determined to identify the culprit, but Jim Halpert turns the tables: [More]


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