Scientific American News Feed

A plume or not a plume? That was the question for scientists, oil company employees and government officials in the early days of the oil spill into the Gulf of Mexico from BP's Macondo 252 well . [More]

More than three-quarters of new HIV infections worldwide are acquired through sexual contact, nearly all of which involve at least one male. As researchers have been uncovering a growing number of differences between the semen-based virus and blood-borne populations--and the number of people with the virus continues to rise rapidly--the race to piece together a better understanding of the virus's makeup and behavior in the male genital tract has grown ever more urgent. [More]

Ketamine --a powerful anesthetic for humans and animals that lists hallucinations among its side effects and therefore is often abused under the name Special K--delivers rapid relief to chronically depressed patients, and researchers may now have discovered why. In fact, the latest evidence reinforces the idea that the psychedelic drug could be the first new drug in decades to lift the fog of depression. [More]

It's an unfortunate fact of life that people often shrink a bit as they age. But we can at least take solace in the fact that the moon, too, seems to be have gotten a bit smaller of late. [More]

Researchers may have found a new form of chlorophyll, the pigment that plants, algae and cyanobacteria use to obtain energy from light through photosynthesis . Preliminary findings published August 19 in Science suggest that the newly discovered molecule, dubbed chlorophyll f, has a distinct chemical composition when compared with the four known forms of chlorophyll and can absorb more near-infrared light than is typical for the photosynthetic pigments. Chlorophyll f, which was extracted from cultures of cyanobacteria and other oxygenic microorganisms, may allow certain photosynthetic life forms to harvest energy from wavelengths of light that many of their competitors cannot use.

"This is the most red-shifted chlorophyll we have found in nature," says Min Chen , a biologist at The University of Sydney in Australia and lead author of the study. "That means that organisms that have this chlorophyll inside can extend their photosynthetic range for maximum use of solar energy."

Editor's note: This story is part of a series of online exclusives about natural phenomena and human endeavors we'd like to see come to an end. They are connected with the September 2010 special issue of Scientific American called " The End ".

Mosquitoes that carry the Plasmodium parasite cause some 300 million cases of malaria every year, claiming one million lives. That's a lot of carnage generated by an insect smaller than a pinky fingernail--but if enterprising researchers have their way, their blood-thirsty assault won't continue much longer. Here are some of the most promising strategies for wiping out malaria-carrying mosquitoes:

Populations of southern, or California, sea otters ( Enhydra lutris nereis ) have declined for the second year in a row, including a dramatic drop in births, according to new numbers released by the U.S. Geological Survey (USGS). At the same time, the money necessary to study and help save the sea otters could soon evaporate amidst California's budget crisis.

When you think of someone who’s trusting, you may assume that they’re gullible. But that’s not necessarily true--a fact that your Pollyanna pal might be in a good position to point out. Because people who have faith in their fellow human beings are actually good at spotting lies. The finding is described in the journal Social Psychological & Personality Science . [Nancy Carter and J. Mark Weber, http://bit.ly/bOEFLN] [More]

The word “psychopath” conjures up movie images of brutal, inexplicable violence: Jack Nicholson chasing his family with an ax in The Shining or Anthony Hopkins as Hannibal Lecter, his face locked into an armored mask to keep him from biting people to death. But real life offers another set of images, that of killers making nice: Ted Bundy as law student and aide to the governor of Washington State, and John Wayne Gacy as the Junior Chamber of Commerce’s “Man of the Year.” Psychopaths are likable guys when they want to be.

Between the two of us, we have interviewed hundreds of prison inmates to assess their mental health. We are trained in spotting psychopaths, but even so, coming face to face with the real article can be electrifying, if also unsettling. One of the most striking peculiarities of psychopaths is that they lack empathy; they are able to shake off as mere tinsel the most universal social obligations. They lie and manipulate yet feel no compunction or regrets--in fact, they don’t feel particularly deeply about anything at all.

“Does ‘accommodate’ have one ‘m’ or two?” asked an editor in our open workspace. Almost before I could say “two,” the boss flew at us from her office. “Why aren’t you working?” she demanded. She seemed mollified by my explanation. She stalked back to her office chair, periodically watching us through the glass window in the wall.

None of us focused too well for a while after that. But her whipsaw behavior was only part of the reason. As I now know--and as you will learn from “Cubicle, Sweet Cubicle,” by sociologists S. Alexander Haslam and Craig Knight--the workspace itself already had done most of the productivity damage. We could not put what we wanted atop our desks, lest we ruin the cohesive look. The seating was changed without discussion. The lack of control over our situation interfered with our concentration. It’s not difficult, however, to create better workspaces. Click here to learn how.

Death used to be a simple affair: either a person’s heart was beating, or it was not. That clarity faded years ago when heroic medical technology started to keep hearts beating in­definitely. Although we have had decades to ponder the distinctions between various states of grave physiological failure, if anything our confusion has grown. When is it ethical to turn off a ventilator or remove a feeding tube? When does “life support” lose its meaning? And most critically, at what point is it acceptable to cut into a body and remove the heart that could save another life?

These issues are not academic. They raise questions about health care costs--is it worth using expensive machinery on a body that is for all intents and purposes dead?--as well as about dignity in end-of-life care. This year’s “death panel” subplot of the health care debate fed off the real fears people have about being taken advantage of when at their weakest.

If you were given a free hand to plan how your life will end--your last weeks, days, hours and minutes--what would you choose? Would you, for example, want to remain in great shape right up until the last minute and then go quickly? Many people say they would choose that option, but I see an important catch. If you are feeling fine one moment, the very last thing you would want is to drop dead the next. And for your loving family and friends, who would suffer instant bereavement, your sudden death would be a cruel loss. On the other hand, coping with a long, drawn-out terminal illness is not great either, nor is the nightmare of losing a loved one into the dark wastes of dementia.

We all prefer to avoid thinking about the end of life. Yet it is healthy to ask such questions, at least sometimes, for ourselves and to correctly define the goals of medical policy and research. It is also important to ask just how far science can help in efforts to cheat death.

By Ewen Callaway

An age-old mixture of four herbs could spare patients with cancer some of the side effects of chemotherapy.

The cocktail comprises Chinese peonies, Chinese liquorice, the fruit of the Chinese date tree and flowers of the Chinese skullcap plant. [More]

The large , big-beaked "terror birds" (Phorusrhacidae) didn't need flight to snag a Miocene meal. Some of these extinct, flightless fowl likely used their massive rigid skulls and hooked beaks to chomp into prey with strong, successive pulls, concluded a research team after performing a biomechanical analysis of fossilized skulls. [More]

Nearly a decade after the U.S. launched its National Nanotechnology Initiative (NNI) , the program's $12 billion in funding has helped place the country at the head of the pack regarding the development of science and technology measured in billionths of meters . Yet, despite the U.S.'s unrivaled adeptness at patenting nanotech inventions, the country's lackluster track record of bringing nano-scale technology products to market leaves the door open for China, Russia and other tech-savvy countries to challenge U.S. nanotech supremacy, according to a new report by Boston's Lux Research . [More]

Editor's Note: Students from Dartmouth's Thayer School of Engineering are working in Tanzania to help improve sanitation and energy technologies in local villages. The student-led group , known as Humanitarian Engineering Leadership Projects (HELP), will file dispatches from the field during their trip. This is their fifth blog post for Scientific American.

The water taxi edged past the final jungled outcrop of Gombe Park in Tanzania. As we crept away from the park towards civilization, the monkey-filled trees of Gombe faded into burned out hillsides replete with palm oil trees and dust. It was in this scarred land that I caught a first glimpse of the village Mwamgongo: my home for the next two months. [More]

By Rex Dalton

The rapper Earl 'DMX' Simmons is not known for his conciliatory lyrics. [More]

On the morning of September 29, 2009, a violent temblor shook the South Pacific seafloor between the islands of Tonga, Samoa and American Samoa. The earthquake stirred up tsunami waves that quickly pummeled the islands; nearly 200 people were killed, most of them in Samoa. [More]

Infectious tropical diseases such as river blindness and trachoma can be compelling targets around which to rally government and community campaigns to combat these scourges . But are these programs diverting limited resources away from basic medical and preventive care? [More]

* Kemp's Ridley turtles hit hard by spill

* Hospital treating 171 oiled sea turtles