Scientific American Online

How’s this for a possible new culprit for breast cancer sufferers: they may be able to blame their grandmas’ diets. That’s the implication of a study done with rats. Researchers [Sonia de Assis et al.] affiliated with the Georgetown University Medical Center fed a group of pregnant rats a high-fat diet throughout their gestation, with 43 percent of calories coming from fat. A control group ate a normal diet. Both groups consumed the same total calories. All the rats’ offspring and the next generation, the granddaughters, ate a normal diet.

That high-fat diet increased breast cancer in the rats’ female offspring. And, more surprisingly, it apparently increased breast cancer in the granddaughters. They had an 80 percent chance of developing the disease, compared with 50 percent in the control group. The results were presented at the meeting of the American Association for Cancer Research.

The ash cloud that rose from a volcano in Iceland last week to halt air traffic in the U.K. and much of the rest of Europe appears to be easing its stranglehold on transportation. EUROCONTROL , an intergovernmental air traffic control organization based in Brussels, announced Monday that its member states were designating a limited "no-fly zone" beyond which airlines would be permitted to operate by Tuesday morning. [More]

Last year 17 Florida panthers ( Felis concolor coryi ) were killed when they were struck by vehicles, an all-time high and a terrible blow to one of North America's most endangered mammals. Only 100 or so panthers remain in Florida, and the species shows signs of heavy inbreeding due to its limited population.

Panthers are already protected by law, and drivers face heavy fines for speeding in known panther zones, but that hasn't done much to stop these unnecessary deaths.

By Geoff Brumfiel

By pushing a cluster of just 60 ions with a tiny electric field, researchers have measured the most minuscule force ever.

The result, measuring mere yoctonewtons (10^-24 newtons), beats previous record lows by several orders of magnitude. [More]

By Geoff Brumfiel

By pushing a cluster of just 60 ions with a tiny electric field, researchers have measured the most minuscule force ever.

The result, measuring mere yoctonewtons (10^-24 newtons), beats previous record lows by several orders of magnitude. [More]

Thousands of budding engineers and roboticists from around the world converged in Atlanta's Georgia Dome this past weekend to see whose robot was the best of the best in the 19th annual FIRST (For Inspiration and Recognition of Science and Technology) championship. The tournament's three different robotics competitions were the culmination of months of hard work and commitment for the students and their mentors. [More]

Scientists have finally verified something that Jersey Shore stars Snooki and Pauly D have probably known all along--that getting your bronze on at the tanning salon may be addictive. And the more often you tan, the more likely you are to get hooked, according to a study in the Archives of Dermatology . [Catherine Mosher and Sharon Danoff-Burg, http://bit.ly/bulE8u ]

The researchers started with two questionnaires commonly used to assess patients for alcohol abuse and substance-related disorders. But they modified the questions to focus on indoor tanning habits. For example: "Do you try to cut down on the time you spend in tanning beds or booths but find yourself still tanning?" [More]

LONDON (Reuters) - An ash cloud from a volcano in Iceland has spread across the Atlantic Ocean and brushed the Canadian coast, but is not expected to drift much further across North America, British forecasters said on Monday.

Britain's Met Office, the national weather service, said the vast cloud that has grounded thousands of flights across northern Europe reached Newfoundland on Monday.

WASHINGTON (Reuters) - The United States released a new draft report on climate change on Monday, one week before the expected unveiling of a compromise U.S. Senate bill that aims to curb heat-trapping greenhouse emissions.

The report, a draft of the Fifth U.S. Climate Action Report that will be sent to the United Nations, says bluntly: "Global warming is unequivocal and primarily human-induced ... Global temperature has increased over the past 50 years. This observed increase is due primarily to human-induced emissions of heat-trapping gases."

MONTREAL--When we're under immediate stress --say, we are about to give a speech or about to be mugged--we either fight or flee, or so scientists have long preached. But some psychologists are now suggesting that this scenario may apply mainly to males. Men get antisocial under pressure, but women tend to react in the opposite way: they "tend and befriend," engaging in nurturing and social networking, perhaps as a way to protect their offspring, according to a theory proffered by neuroscientist Shelley Taylor of the University of California, Los Angeles. Here at the Cognitive Neuroscience Society 2010 annual meeting, psychologist Mara Mather of the University of Southern California presented powerful new support for Taylor's hypothesis in the divergent ways that stressed men and women respond to faces. [More]

ERICE, Italy--If you think of Earth's poles as fraternal twins, the Arctic has been the wild one in recent years, while the Antarctic has been a steady plodder. Withered by summer heat, Arctic sea ice has shrunk to record low coverage several times since 2005, only to rebound to within 95 percent of its long-term average extent this winter. By comparison, Antarctica, with some 90 percent of the world's glacial reserves, has generally shed ice in more stately fashion.     [More]

A casual spin last night through the pile of ads inserted inside my local Sunday newspaper made it clear to me that the best possible thing we all can do this week to honor Earth is to shop till we drop. [More]

An experiment is gearing up in Texas to take on one of the universe's biggest mysteries by compiling a three-dimensional map of the early cosmos. The hope is that the survey will help inform astronomers and cosmologists about the nature of dark energy, a mysterious and hypothetical agent thought to constitute nearly three quarters of the universe's mass. [More]

What is the memory capacity of the human brain? Is there a physical limit to the amount of information it can store? --J. Hawes, Huntington Beach, Calif.

What goes on in the brain of the groom who says “I do,” then has an affair? Or the friend who pledges to repay a loan but never does? Breaking a promise is a complex neurobiological event, a new study shows--and a brain scan may be able to predict those who are making false promises before they break their word.

Using functional MRI, scientists at the University of Zurich in Switzerland scanned the brains of subjects playing an investment game. Subjects assigned to be “investors” had to decide whether to pledge to share their money with other players who were “trustees.” This arrangement boosted the amount of money in the pot, but it also could result in a loss to the investor if the trustee chose not to share. Nearly all the subjects said they would give to the trustee--but in the end, not everyone kept this promise.

The African island of Madagascar, situated some 430 kilometers off the coast of Mozambique, is famous for its unique fauna, particularly its charismatic primates, the lemurs. But how the lemurs and other land mammals got there has proved an enduring mystery. To that end, new evidence supports a theory that some experts once considered unlikely: namely, that the forerunners of Madagascar’s modern mammals reached the island millions of years ago by drifting from the African mainland across the Mozambique Channel on giant rafts of vegetation ripped from the shore and launched out to sea by violent storms.

Reconstructing ancient dispersal routes is a complex exercise. On Madagascar this puzzle is complicated by the fact that the fossil record of mammals from the past 65 million years is meager. Based on the paltry available clues, some researchers thought the ancestral mammalian stock arrived via a landbridge that later disappeared with the shifting of landmasses. But geologic evidence of such landbridges is weak at best. Moreover, this theory cannot account for why the island’s many endemic terrestrial mammal species represent only four of Africa’s broader mammal groups called orders. And all of Madagascar’s land mammals are relatively small--no elephants, lions or giraffes there. If landbridges existed, critics argued, why did only small mammals belonging to these four orders make the trip over?

By Gopal Sharma

By Omar Valdimarsson

REYKJAVIK (Reuters) - Powerful tremors from an Icelandic volcano that has been a menace for travelers across Europe shook the countryside on Sunday as eruptions hurled a steady stream of ash into the sky.

NEW YORK--Will exotic orchids soon be subjected to the same genetic scrutiny as some luxury caviars? That is just one of the coding conundrums that scientists convened at the New York Botanical Garden in the Bronx to discuss on a cloudy mid-April afternoon. [More]