Earth

Health & Medicine

For a lucky few, ‘dioxins’ might be heart healthy

Dioxins and their kin are notorious poisons. They work by turning on what many biologists had long assumed was a vestigial receptor with no natural beneficial role. But it now appears that in a small proportion of people, this receptor may confer heart benefits.

Climate

National academies to review IPCC procedures

Global science organizations asked to help evaluate processes that produced 2007 climate report.

Climate

Ancient Norse colonies hit bad climate times

Temperatures in Iceland plummeted soon after settlers arrived, a new chemical analysis suggests.

Earth

Green-ish pesticides bee-devil honey makers

Pesticides are agents designed to rid targeted portions of the human environment of undesirable critters – such as boll weevils, roaches or carpenter ants. They’re not supposed to harm beneficials. Like bees. Yet a new study from China finds that two widely used pyrethroid pesticides – chemicals that are rather “green” as bug killers go – can significantly impair the pollinators’ reproduction.

Earth

Country ants make it big in the city

Odorous house ants act like invading aliens when they discover urban living.

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.