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Plant ecologist Mark A. Davis will not participate in this year’s “Buckthorn Roundups” around his St. Paul, Minn., neighborhood. ­Davis will not tag along as these intrepid crusaders set out to eradicate the common and glossy buckthorn, two ornamental shrubs imported in the 19th century from Europe. The nonnatives have now taken over some Midwestern forests, prairies and wetlands. That is why eco-minded volunteers eagerly wrench young weeds from the soil, hack away at thick stems and douse remaining stumps with herbicides....

By Marian Turner of Nature magazineBats use tiny hairs to sense the speed and direction of air flowing over their wings. This may alert them to the danger of stalling and enable them to perform impressive aerobatic tricks, according to a report published today in the Proceedings of the National Academy of Sciences.Bats are the only mammals capable of powered flight; their wings are made of a membrane covered with microscopic hairs....

By Geoff BrumfielAstronomers have used a high-energy burst of light from a distant galaxy to test the fabric of space and time. The work is the best test yet of attempts to create a ’theory of everything’.At present, two separate theories dominate the world of physics. General relativity explains gravity and the motion of large objects such as planets, stars and galaxies, whereas quantum-mechanics explains the behaviour of very small things such as atoms....

PALO ALTO, CALIF.—It was perhaps the most highly touted press conference of the week, but it didn’t reveal much in the way of evidence: Three bigfoot enthusiasts announced today that a series of genetic tests performed on samples taken from a carcass they claim is a Sasquatch came back as a mixture of human and opossum. In addition to the mixed DNA results, Tom Biscardi, Matthew Whitton and Rick Dyer showed the audience two blurry photos, one of a solitary figure in mixed hardwood forest and another of the mouth of what appeared to be the tongue and teeth of a primate....

Modern conservation efforts focus on saving as much biodiversity as possible–and preventing living species from going the way of the dodo. Already, roughly 10 percent of the world’s land falls inside of protected reserves. But new research highlights the mammals most at risk of disappearing in the near future even if they are unthreatened now, and the majority fall outside current conservation boundaries. Biologist Marcel Cardillo of Imperial College London and his colleagues first estimated the overall risk of extinction a given mammal faced based on factors that led to the loss of other species in the past: a limited and specific geographic range, large size and relatively long periods of time needed to mature and reproduce....

In many classic science-fiction stories, alien life is based on silicon–the substance at the core of modern electronics technology–rather than on carbon, the fundamental building block of earthly biology. Scientists have even speculated that they might someday create silicon life-forms. Instead the opposite is starting to happen: carbon is serving as the foundation for electronic devices–and in the process is breathing new life into the quest for inexpensive, flexible products that offer a broad range of capabilities....

Climate change helped fuel stronger, wetter storms during an unusually active Atlantic hurricane season in 2020, a new study finds. The cyclones produced significantly more rainfall than they would have in a world without global warming. The most extreme three-hour rainfall rates that season were about 10 percent higher because of the influence of climate change, the study found. And the most extreme three-day rainfall rates were about 5 percent higher....

It is one of the great dilemmas of climate change: We take such comfort from air conditioning that worldwide energy consumption for that purpose has already tripled since 1990. It is on track to grow even faster through mid-century—and assuming fossil-fuel–fired power plants provide the electricity, that could cause enough carbon dioxide emissions to warm the planet by another deadly half-degree Celsius. A paper published Tuesday in the Nature Communications proposes a partial remedy: Heating, ventilation and air conditioning (or HVAC) systems move a lot of air....

The following essay is reprinted with permission from The Conversation, an online publication covering the latest research. As Bill Gates sees it, there are three main threats to our species: nuclear war, climate change and the next global pandemic. Speaking on pandemic preparedness at the Munich Security Conference earlier this year, Gates reminded us that “the fact that a deadly global pandemic has not occurred in recent history shouldn’t be mistaken for evidence that a deadly pandemic will not occur in the future....

A T-shirt made in 2050 could look exactly like one worn by William the Conqueror a thousand years earlier to someone using radiocarbon dating if emissions continue under a business-as-usual scenario. By 2100, a dead plant could be almost identical to the Dead Sea scrolls, which are more than 2,000 years old. These well-known “aging” properties of atmospheric carbon were pinpointed for different emissions scenarios in a paper published in the Proceedings of the National Academy of Sciences yesterday....

A group of nuclear power experts and former regulators from 11 nations, responding to Japan’s nuclear disaster, is calling for “stress tests” on the world’s reactors to determine their ability to withstand extreme earthquakes, flooding or other natural disasters that strike singly or in combination. In a letter to the International Atomic Energy Agency in advance of the IAEA meeting later this month on the Fukushima Daiichi accident, the 17-member ad hoc group also urges that safety requirements for new nuclear plants be reviewed....

Mountaintops leveled. Tar sands scraped and boiled. Water taps aflame. These are just a few of the ways that mankind’s quest for fossil fuels manifests itself, beyond the obvious utility of being able to power a home or business or drive a car. Industrialized civilization relies on coal, oil and natural gas—the stored sunlight collectively known as fossil fuels—for more than 80 percent of the energy that enables everything from driving to reading on a computer screen....

Complex Tears: Why Humans Like to Cry: Tragedy, Evolution, and the Brainby Michael Trimble Oxford University Press, 2012 ($29.95)Mammals can all produce tears, yet humans are the only ones who cry. In his new book Why Humans Like to Cry, neurologist Trimble delves into how evolution and culture seemingly shaped the human brain to express emotion on a higher level than the rest of the animal kingdom. Weeping may have been one of the earliest forms of hominid communication....

CAMBRIDGE, Mass.—In preparation for a keynote about the future of mobile technology at Technology Review’s Emerging Technologies (EmTech) conference here Wednesday, four panelists had been asked to bring their favorite gadget with them onstage. One might have expected the keynote to become a show-and-tell about Apple’s iPad or iPhone 4, or even the latest e-reader. Instead, each of the panelists revealed devices that were slight variations on the same idea—a portable base station used to boost wireless signals....

“My biological clock is ticking.” The phrase typically pops up in movies about middle-aged women who want to start a family before menopause makes it impossible. But a new study published May 23 in PLoS ONE indicates that another clock may also be important for females trying to conceive: the one that regulates our waking and sleeping cycles. A strong body of evidence links daily wake-sleep cycles to feminine reproductive cycles....

Editor’s note (3/11/11): This article is from the forthcoming April issue of Scientific American. We are posting the text of the article early in light of the deadly Japan earthquake and resulting tsunami. Earthquakes are unique in the pantheon of natural disasters in that they provide no warning at all before they strike. Consider the case of the Loma Prieta quake, which hit the San Francisco Bay Area on October 17, 1989, just as warm-ups were getting under way for the evening’s World Series game between the San Francisco Giants and the Oakland A’s....

How well does a prescription drug work? It can be hard for even doctors to know. Pharmaceutical companies frequently withhold the results of negative or inconclusive trials. Without a full accounting, a physician who wants to counsel a patient about whether a drug works better than a sugar pill is frequently at a loss. Drug companies share only airbrushed versions of data on safety and usefulness. As a consequence, regulators can approve drugs that have hidden health hazards....

The leaves of the herb kratom (Mitragyna speciosa), a native of Southeast Asia in the coffee family, are used to relieve pain and improve mood as an opiate substitute and stimulant. The herb is also combined with cough syrup to make a popular beverage in Thailand called “4x100.” Because of its psychoactive properties, however, kratom is illegal in Thailand, Australia, Myanmar (Burma) and Malaysia. The U.S. Drug Enforcement Administration lists kratom as a “drug of concern” because of its abuse potential, stating it has no legitimate medical use....

It’s been a long, strange trip out of the solar system for NASA’s Voyager 1 spacecraft, and it may be a bit longer still. Voyager 1, which launched 35 years ago, has ventured farther from Earth than any other spacecraft. The probe is now 18.2 billion kilometers from the sun—more than three times the average distance of Pluto. Voyager 1 is well on its way to an astonishing feat—escaping the sun’s jurisdiction and venturing into interstellar space....

Conspiracy theorists may wonder, why does NASA’s next major telescope director need top secret clearance? The space agency recently posted a want ad for a person to lead its James Webb Space Telescope (JWST) program, and in addition to aerospace engineering credentials and management experience, the candidate must have the highest possible level of security credentials. NASA says the requirement is standard, although the ad raised some eyebrows in the security community....