Two spotted seals orphaned as pups in the Arctic are now thriving at UC Santa Cruz's Long Marine Laboratory, giving scientists a rare opportunity to learn about how these seals perceive their environment. In a comprehensive study of the hearing abilities of spotted seals, UCSC researchers found that the seals have remarkably sensitive hearing in both air and water.

Picture a single cloud large enough to span the solar system from the sun to beyond Pluto's orbit. Now imagine many such clouds orbiting in a vast ring at the heart of a distant galaxy, occasionally dimming the X-ray light produced by the galaxy's monster black hole.

Using data from NASA's Rossi X-ray Timing Explorer (RXTE) satellite, an international team has uncovered a dozen instances where X-ray signals from active galaxies dimmed as a result of a cloud of gas moving across our line of sight. The new study triples the number of cloud events previously identified in the 16-year archive.

For the first time, an international team of astrophysicists, including Lawrence Livermore National Laboratory scientists, have unraveled how stars blow up in supernova explosions.

Using NASA's Nuclear Spectroscopic Telescope Array (NuSTAR) – a high-energy X-ray observatory - the international collaboration created the first-ever map of radioactive material in a supernova remnant, named Cassiopeia A, or Cas A for short. The findings reveal how shock waves likely rip apart massive dying stars, and ultimately end their lives.

A reduced risk of cervical lesions among Danish girls and women at the population level is associated with use of a quadrivalent HPV vaccine after only six years, according to a new study published February 19 in the Journal of the National Cancer Institute.

The synthetic chemicals used in the packaging, storage, and processing of foodstuffs might be harmful to human health over the long term, warn environmental scientists in a commentary in the Journal of Epidemiology and Community Health.

This is because most of these substances are not inert and can leach into the foods we eat, they say.

Despite the fact that some of these chemicals are regulated, people who eat packaged or processed foods are likely to be chronically exposed to low levels of these substances throughout their lives, say the authors.

And far too little is known about their long term impact, including at crucial stages of human development, such as in the womb, which is "surely not justified on scientific grounds," the authors claim.

PROVIDENCE, R.I. [Brown University] — Out of an effort to account for what seemed in airborne images to be unusually large tree growth in a Hawaiian forest, scientists at Brown University and the Carnegie Institution for Science have developed a new mathematical model that predicts how trees compete for space in the canopy.

What their model revealed for this particular forest of hardy native Metrosideros polymorpha trees on the windward slope of Manua Kea, is that an incumbent tree limb greening up a given square meter would still dominate its position two years later a forbidding 97.9 percent of the time. The model described online in the journal Ecology Letters could help generate similar predictions for other forests, too.