Earth

Life

Mature females key to beluga sturgeon survival

Hatchery fish are unlikely to restore caviar-producing fish populations, a new assessment finds.

Earth

Fowl surprise! Methylmercury improves hatching rate

A pinch of methylmercury is just ducky for mallard reproduction, according to a new federal study. The findings are counterintuitive, since methylmercury is ordinarily a potent neurotoxic pollutant.

Space

Geophysicists push age of Earth’s magnetic field back 250 million years

South African rocks suggest that the earliest stages of life on Earth were protected from harmful solar radiation.

Earth

Arctic seafloor a big source of methane

Measurements show that Arctic undersea methane deposits, previously thought to be sealed by permafrost, are leaking into the atmosphere.

Earth

Earth knocked for a loop

Chile’s February 27 temblor, tectonically linked to another giant quake 50 years ago, sped up the Earth’s rotation and tipped the planet’s axis.

Chemistry

Plasticizers kept from leaching out

‘Chemicals of concern’ may be made safer in new materials.

Agriculture

Frogs: Clues to how weed killer may feminize males

Atrazine, a widely used agricultural herbicide, not only can alter hormone levels in the developing frogs, but also perturb their physical development — and lead to an excess number of females, researchers report. Their new findings may help explain observations reported by a number of other research groups that at least in frogs, fairly low concentrations of atrazine can induce a feminization — or demasculinization.

Paleontology

Ancient DNA suggests polar bears evolved recently

A study of a rare Norwegian fossil narrows down when polar bears evolved and finds they are closely related to modern-day brown bears in Alaska.

Earth

Frogs: Weed killer creates real Mr. Moms

Several months back, a Berkeley undergraduate began witnessing distinctly odd behavior in frogs she was caring for in the lab. At about 18-months old, some frisky guys began regularly mounting tank mates, as if to copulate. Except that their chosen partner was invariably male. He had to be. Because genetically, every animal in the tank was male.

Climate

IPCC looks to vet, report climate-science better

Major U.S. science organizations aren’t the only ones to realize that the climate-science community has bungled – and badly – its portrayals of research on global change in recent months, if not years, and its responses to criticisms. Yesterday, the Intergovernmental Panel on Climate Change (a group established by the United Nations and World Meteorological Organization) said: “we recognize the criticism that has been leveled at us and the need to respond.” So will be convening an “independent review” panel to investigate what the organization’s procedures should be to vet not only the data it uses and how to synthesize conclusions based on those data, but also how it should convey those conclusions (and any necessary caveats) in reports to the public and policymakers.

Health & Medicine

Germs in tobacco are potential source of respiratory infections blamed on smoking

Tests find hundreds of bacterial species in major cigarette brands.

Life

Hydrothermal vents sometimes colonized from afar

Deep-sea currents can waft larvae hundreds of kilometers.