At the center of our galaxy is a sleeping giant, a black hole more than four million times as massive as the sun. The Milky Way’s supermassive black hole is mostly quiet, nibbling on small objects at the galactic center and giving off only faint belches of radiation as it digests its prey. But in the past the sleeping giant may have been wide awake--and wreaking havoc.

The rat stood on its hind limbs at one end of a narrow runway. It wore a tiny black vest attached to a robotic arm that hovered above its head. Without such mechanical support, the rat would have fallen over--its spinal cord had two deep cuts, rendering its back legs useless. Rubia van den Brand , then a doctoral candidate at the University of Zurich, stood at the other end of the runway, urging the animal to walk. Although the robotic arm kept the rat upright, it could not help the creature move; if the rodent were ever to walk again, it would have to will its feet forward. For the first time since van den Brand began her experiments, the rat moved one of its back legs on its own--a small, effortful step. She ran to her boss's office with the news and a crowd immediately gathered in the lab to watch what many had deemed impossible. [More]

A farmer in Mozambique grows peas, beans and cassava in rotation--enough to feed the family with a little to spare. The farmer then sells that excess to CleanStar Mozambique, which dries and packages the produce for sale in the capital, Maputo. But the company also takes the surplus cassava , a starch-filled root and local food staple, and sends it to an ethanol fermentation plant built by ICM, a U.S. ethanol company, that employs enzymes produced by Denmark-based Novozymes. The ethanol produced is then sold in reusable plastic bottles to people in Maputo who own one of the 3,000 or so ethanol-burning clean cookstoves sold by CleanStar. When the fuel runs out, more can be purchased at an incipient network of CleanStar shops.

Birds are the only dinosaurs that have survived into modern times. Why is that? Of all the dinosaur species, how did they manage to make it through the catastrophic events of 65 million years ago, whereas all their fellow dinos perished? A new study, published May 27 in Nature , hints at an evolutionary phenomenon that may have played to birds' advantage: They are, it seems, baby dinosaurs whose biology prevents them from ever growing up. ( Scientific American is part of Nature Publishing Group.)

Mildred Dresselhaus, the so-called “queen of carbon science,” took home the $1-million Kavli Prize in Nanoscience today. The materials scientist from the Massachusetts Institute of Technology was awarded for her work in revealing the strange thermal and electrical properties that carbon develops at the atomic scale. These discoveries helped lead to the development of novel materials, such as graphene and carbon nanotubes , which have applications in energy, medicine, optics and electronics.

Wait a minute. There's something unusual about the subway seat you just claimed. It's awfully warm, and a peculiar odor seems to hover in the air nearby--a stale, musty odor tinged with something as acrid as mothballs. You know this aroma: it's "old person smell." [More]

From Nature magazine

From Nature magazine

Thirty-two years ago this month an explosive eruption reshaped Mount Saint Helens in a matter of seconds. An earthquake under the volcano in Washington State on May 18, 1980, triggered the largest landslide in recorded history as billions of cubic meters of mountainside tumbled away, initiating a massive release of gas, lava and ash. The cataclysm killed 57 people and sent a plume some 20 kilometers into the sky.

From Nature magazine

The nation's oil and gas wells produce at least nine billion liters of contaminated water per day, according to an Argonne National Laboratory report. And that is an underestimate of the amount of brine, fracking fluid and other contaminated water that flows back up a well along with the natural gas or oil, because it is based on incomplete data from state governments gathered in 2007.

The typical supermarket tomato: ripe red, firm to the touch, free of blemishes--and of flavor. Since at least the 1970s, U.S. consumers have lamented the beautiful but bland fruits that farmers breed not for taste, but rather for high yield and durability during shipping. Recently, organic farmers and foodies have championed the superior flavors of heirloom tomatoes --older varieties that come in an assortment of shapes, sizes and colors. In a new study, researchers took a close look at the chemical composition of both standard tomatoes and hundreds of different heirloom varieties, which they also fed to 170 volunteers in a taste test. Their new findings confirm what scientists have learned in recent years: a tomato's flavor depends not only on the balance of sugars and acids within the fruit, but also on subtle aromatic compounds--many of which are lacking in the modern supermarket tomato. In the future the researchers hope to work with seed companies and farmers to breed tomatoes that produce large quantities of flavorful fruits packed with aromatic compounds--a healthier solution than engineering super-sugary tomatoes. [More]

From Nature magazine

“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. 

From Nature magazine [More]

Remember how Wile E. Coyote, in his obsessive pursuit of the Road Runner, would fall off a cliff? The hapless predator ran straight out off the edge, stopped in midair as only an animated character could, looked beneath him in an eye-popping moment of truth, and plummeted straight down into a puff of dust. Splat! Four decades ago, a Massachusetts Institute of Technology computer model called World3 warned of such a possible course for human civilization in the 21st century. In Limits to Growth , a bitterly disputed 1972 book that explicated these findings, researchers argued that the global industrial system has so much inertia that it cannot readily correct course in response to signals of planetary stress. But unless economic growth skidded to a halt before reaching the edge, they warned, society was headed for overshoot--and a splat that could kill billions.

By June 15 gasoline-powered augers will have drilled 100 holes in the corn, cotton and peanut fields of the Lower Flint River Basin in southwest Georgia. Into the holes, scientists from the University of Georgia (U.G.A.) will slip half-meter-long PVC pipes filled with sensors for soil moisture and temperature topped with a flexible antenna that can be run over by a tractor and spring back into place. Over the course of the next two years, these sensors will continuously relay soil conditions from 20, 40 and 60 centimeters deep to a computer. Combined with more accurate weather forecasts , the data will help farmers decide where and when to use their irrigation systems.

By Katharine Sanderson of Nature magazine

Getting up close and personal with a furry tarantula is probably the very last thing someone with a spider phobia would opt for, but the encounter may be the ticket to busting the brain's resistance to arachnids.

BERLIN, Md.--Fifth grader Aman Shahzad looked closely at the level attached to the plumb line. "Lower, lower," she called out. "OK! The bubble is in the middle." Her classmate, holding the wooden surveyor's pole, read the measurement: 14 centimeters.