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A collective effort to scrutinize one of the biggest mysteries in mathematics has ended with a few clues but no firm answers. The mystery concerns an impenetrable but potentially groundbreaking proof of a puzzle known as the abc conjecture, which appeared online three years ago. Whether the proof is valid is still not clear—a source of frustration for some of the leading specialists who gathered at the University of Oxford on December 7–11 to discuss the matter....

“There is nothing more painful to me at this stage in my life,” Jesse Jackson once told an audience, “than to walk down the street and hear footsteps and start thinking about robbery—then look around and see somebody white and feel relieved.” Jackson’s remark illustrates a basic fact of our social existence, one that even a committed black civil-rights leader cannot escape: ideas that we may not endorse—for example, that a black stranger might harm us but a white one probably would not—can nonetheless lodge themselves in our minds and, without our permission or awareness, color our perceptions, expectations and judgments....

When my parents came to the U.S. in 1973 as refugees from Uganda’s brutal dictator Idi Amin, we were one of the only South Asian families on my block in the suburbs of Chicago. As I grew up, my father wished for me to become one of three things: a doctor, a lawyer or an engineer like he was. To him, these were the jobs with the highest earning potential—jobs that could help our family rise up into the middle class....

Yesterday, a magnitude 6.3 earthquake struck L’Aquila, Italy, killing more than 150 people, injuring some 1,000, and leaving thousands of people homeless. Soon after the deadly temblor hit, news outlets including Time magazine, Reuters, and The New York Times reported Italian authorities had previously removed from the Internet a warning that a big quake was imminent. The prediction had been posted weeks earlier by a techician at the Gran Sasso National Laboratory in Abruzzi, Italy....

Obese mice—like obese humans—are at increased risk of colon cancer, and a study published today in Nature finally suggests why. Overweight mice fed a high-fat diet showed an increase in intestinal stem cells due to activation of a protein called PPAR-δ that regulates metabolism. If the results hold true in humans, they could explain a phenomenon seen in epidemiological studies. “For quite some time there’s been an understanding that obesity leads to an increase in cancer in many tissues,” says Ömer Yilmaz, a cancer biologist at the Koch Institute for Integrative Cancer Research at the Massachusetts Institute of Technology (MIT) in Cambridge, and one of the leaders of the study....

A flowering shrub from the Andean cloud forests made taxonomic history last month. The plant—now dubbed Brunfelsia plowmaniana—had puzzled botanists for decades as they endeavored to determine whether or not it was truly an evolutionary newcomer. When its DNA revealed this to be true, researchers made the unprecedented move to include B. plowmaniana’s genetic code in its description as a new species, in the journal PhytoKeys. That decision could open the door to future DNA definitions of new botanical species—and heal a rift in the field of botany....

Sex differences in the brain are sexy. As MRI scanning grows ever more sophisticated, neuroscientists keep refining their search for male-female brain differences that will answer the age-old question, “Why can’t a woman think like a man?” (and vice-versa). Social cognition is one realm in which the search for brain sex differences should be especially fruitful. Females of all ages outperform males on tests requiring the recognition of emotion or relationships among other people....

Industry and shipping are the hardest climate nuts to crack. Together, they account for about a third of global greenhouse gas emissions, but the cost-competitive technology needed to green both sectors is in short supply. A new paper from the Energy Transitions Commission, a coalition of global energy leaders, outlines a path for breaking both sectors open, zeroing out their emissions by midcentury. It argues that reducing waste, improving energy efficiency, greening the power supply and advancing technologies like carbon capture and biomass will be key to cleaning up planet-warming pollution from airplanes, cement fabricators and steel mills, among others....

I get a nightmarishly recurring call from businesses trying to go green, and it goes something like this: A caller from a (hotel management group, property management firm, Fortune 500 business … fill in the blank) wants to talk about how they could be “greener.” “What do you mean by that?” I ask. “You know,” the caller says, “recycled paper and stuff like that.” Then I usually say something like, “If that level of ‘greening’ is what you want to talk about, you’ve got the wrong guy....

**Update: This contest ended as of September 1st, 2011 at 11:59pm ET. Thank you for your interest. If you would like more information on this topic, take a look at Christof Koch’s June 2011 article, A Test for Consciousness. ** The mystery of human consciousness appears routinely as one of the greatest science problems of all time. One way to get a grip on this seemingly ineffable property would be to build a conscious machine....

By Alphonso Toweh and James Harding Giahyue MONROVIA, May 9 (Reuters) - Liberia was declared free from Ebola by the government and the World Health Organisation (WHO) on Saturday after 42 days without a new case of the virus, which killed more than 4,700 people there during a year-long epidemic. However, celebrations were muted by thoughts for the dead and medical charity Medecins Sans Frontieres (MSF) urged vigilance until the worst outbreak of the disease ever recorded was also extinguished in neighbouring Guinea and Sierra Leone....

The Republican-Democratic debate over income tax rates and the size of government has been long on rhetoric but short on data. What does published research say about what different economic groups do with savings from income-tax cuts? Will the economy slow if Washington cancels tax cuts on millionaires and billionaires? Most experts agree that tax cuts can stimulate a weak economy over the short term through increased consumption and investment, provided the money flows to people who are more likely to spend than save....

For their discovery of ulcer-causing bacteria, Australian doctors J. Robin Warren and Barry Marshall have received the 2005 Nobel Prize in Physiology or Medicine. Until Warren and Marshall’s finding in 1979, physicians thought that excess stomach acid caused by stress ate away at the stomach lining and lead to ulcers. The treatments prescribed ranged from a bland diet to drugs that blocked stomach acid production to, finally, surgery. Then, while examining tissue samples from the stomachs of ulcer patients, Warren noticed the presence of spiral-shaped bacteria....

The number of U.S. women who use long-acting reversible contraceptive devices is soaring, according to a new federal report. The National Center for Health Statistics this week released findings from a national survey based on personal interviews of about 10,400 women. Whereas the birth control pill and the condom are the most commonly used methods, the number of women using long-acting implants such as intrauterine devices (IUDs)—the third-most common method—has gone up dramatically since the beginning of this century....

If you ever get a house, “eventually you get a mouse”—or so Ogden Nash once wrote. And science seems to be catching up with poetry. The standard thinking until now has been that the house mouse, Mus musculus, only began its intimate relationship with humans at the dawn of agriculture, roughly 11,500 years ago. In effect, you had to have a farm, not just a house, before mice moved in to raid the stored grain....

For most people a single bee or wasp sting is one too many. But University of Arizona entomologist Justin Schmidt is a dramatic exception: By his own estimation he has been stung more than 1,000 times by at least 80 kinds of insects as part of his job. After unintentionally collecting a few different types of stings while conducting fieldwork to investigate the social behavior of stinging insects, Schmidt decided to take a cue from medical science and create a sting pain index that ranked each sting on a scale of 1 to 4 with eloquent, almost poetic descriptions of the pain (or lack thereof) they caused....

Even allowing for the fact that these were lilliputian brains, they were not behaving at all according to plan. From the first days of the tiny lab-grown organs’ development, primitive “progenitor cells” romped out of their birthplaces in the deep interior and quickly turned into neurons and glia, specialized cells that do the brain’s heavy lifting, from thinking and feeling and moving to boring old neurological housekeeping. But the cells were jumping the gun....

Microglia, the immune cells of the brain, have long been the underdogs of the glia world, passed over for other, flashier cousins, such as astrocytes. Although microglia are best known for being the brain’s primary defenders, scientists now realize that they play a role in the developing brain and may also be implicated in developmental and neurodegenerative disorders. The change in attitude is clear, as evidenced by the buzz around this topic at this year’s Society for Neuroscience (SfN) conference, which took place from October 17 to 21 in Chicago, where scientists discussed their role in both health and disease....

In the November 2011 issue of Scientific American, author Bijal Trivedi looks at the ongoing controversies surrounding the use of genetically modified mosquitoes to fight dengue fever. We asked biologist Mark Q. Benedict and Helen Wallace, the director of GeneWatch UK, to illuminate the issues surrounding the release of genetically modified insects into the wild. Genetically Modified Mosquitoes Could Be an Important Tool in the Fight against Disease By Mark Q....

One of the most iconic hunks of metal in the world is set to get a demotion. The official metallic cylinder that defines the mass of a kilogram may soon be set aside in favor of a measurement that is defined by fundamental constants of nature. The egg-size alloy of platinum and iridium, known as “Le Grand K,” has sat inside a hermetically sealed room in Paris since 1879. Le Grand K serves as the benchmark against which all other kilograms are compared....