Scientific American

The Gulf of Mexico oil spill this year and subsequent cleanup efforts could drive the world's smallest seahorse into extinction, warns the Zoological Society of London and its marine conservation organization Project Seahorse . 

The tiny dwarf seahorse ( Hippocampus zosterae ), which grows to a maximum length of 2.5 centimeters, can be found only in the ocean waters off the Gulf Coast.

Some dinosaurs had feathers ; others had extendable claws or elaborate spikes . But a newly described species is the first to have been found with a distinctively humped back. [More]

Can the active ingredient in " magic mushrooms " help those with terminal cancer cope with their fate? That was the question asked by researchers, who published the results of their investigation September 6 in Archives of General Psychiatry . [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 ninth blog post for Scientific American. [More]

NEW YORK--There are any number of ways to make money trading, though some prefer the term gambling.

That's because the financial world is full of innovation these days--even in the wake of the Great Recession--which primarily means inventing new instruments to trade. One can still trade the mortgage-backed securities that helped derail the global economy or corporate debt repackaged as bonds. Enron helped pioneer the trade in "physical" electricity, actual power available for purchase on the grid and only physical in the sense that the infrastructure to transport it is more visible than an odorless, colorless greenhouse gas. Both are now lucrative markets, but certainly electricity, despite its physics, is more stable.

Until someone develops a common platform for building robots (think of the combination of Windows and Intel that has made PCs so accessible), the technology will remain elusive to the general public. At least that's the contention of Willow Garage, Inc., a Menlo Park, Calif. company that Wednesday made its PR2 personal robot available to the public . [More]

Some consumers buy organically grown foods because they believe the products are healthier, tastier and better for the environment. But is this assessment true? [More]

Point two laser beams so that they cross each other, and each goes through as if the other one did not exist. Light rays cannot interact with other light rays--or can they? With the help of a single atom, physicists have devised a system in which one light beam can turn another on or off. Such a light switch could serve as the basic component of futuristic optical quantum computers and may help open the way to a quantum version of the Internet, which would offer unbreakable data security.

The device makes use of a phenomenon called electromagnetically induced transparency, in which a laser beam can render opaque clouds of atoms temporarily transparent to a narrow wavelength of light. The cloud can then act as a switch for a second beam, either letting it through or blocking it. The result is similar to what happens with transistors in electronic circuits, where a voltage applied at one electrode controls whether current can flow between two other electrodes.

Inspired by human studies showing that avid coffee drinkers and smokers have a lower risk of Parkinson’s disease, scientists at the University of Washington decided to see what java and cigarettes do to fruit flies. [More]

By Eugenie Samuel Reich

Some time in the next decade, a U.S. [More]

By Ewen Callaway

Journal articles on hormone replacement therapy (HRT) ghostwritten by medical writers employed by the pharmaceutical industry serially understated the treatment's risks and promoted unapproved uses, according to an analysis of industry documents.

The analysis, published September 7 in the journal PLoS Medicine , is based on some 1,500 e-mails, contracts and other documents made public in July 2009, after The New York Times and PLoS Medicine successfully argued that their release would be in the public interest. [More]

Babies born to mothers with HIV have a much smaller risk of getting the virus themselves if medical personnel administer preventive drugs, such as nevirapine, at birth to the moms and their newborns. Nevertheless, a small percentage of those infants will end up getting the disease anyway. And without treatment, some 62 percent of HIV-positive children die before the age of two. [More]

Patients with advanced melanoma rarely live for more than a year after their diagnosis--a prognosis that has not improved for more than 30 years. [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 eighth blog post for Scientific American. [More]

More than a fifth of Africa's freshwater species are threatened with extinction , and their disappearance could threaten livelihoods across the continent, according to a new study by the International Union for Conservation of Nature (IUCN).

The study, conducted for the IUCN's Red List of Threatened Species, assessed 5,167 African freshwater species over a five-year period. Two hundred scientists contributed to the report, which covers fish, mollusks, crabs, aquatic plants and aquatic insects such as dragonflies and damselflies.

NEW YORK--When convincing someone to trade in a commodity that cannot be seen or touched, it's best to hold their hand--even if only by telephone. Standing while talking helps, too, at least for broker Lenny Hochschild, who specializes in convincing everyone from agribusiness to electric utilities to buy and sell in a market that doesn't exist yet--a U.S. market for the right to emit carbon dioxide, the most ubiquitous greenhouse gas changing the global climate.

This is possibly the newest market in the world, a would-be global attempt to create a trade in the greenhouse gas emissions from any nation's fleet of cars, household refrigerators, electric power plants, factories, even farms. It's an attempt to peel back the smothering blanket of global warming by giving people a financial incentive to reduce emissions under an economic concept known as cap and trade.

Always finding excuses to skip the gym? Congrats--you might be able to blame your genes. Because the mere desire to exercise may be inherited, at least in mice. So says a study in the journal Proceedings of the Royal Society B . [Theodore Garland Jr. et al, http://bit.ly/crWNGd ] [More]

All our experience of the world, and ability to act on it, are channelled through our body. The pioneering computer scientist, Alan Turing, correctly realised the human mind is special not particularly because of its computing power, but because the body provides it with a unique interface to the world. Current research in psychology and neuroscience is probing how the brain represents the body. Recent advances have revealed that body representation is fundamentally multisensory, arising from the combination of many different sensory signals. These include classical “senses,” such as touch and vision, and also much more specific signals, such as the flexion or extension of each muscle, which define the body’s posture in space. This information is integrated to construct a multisensory representation of the current state of the body. Intriguingly, multisensory signals also affect what we perceive our body to be like, for example by making us feel like a rubber hand really is our hand! Our thoughts about what our body is are highly flexible, and track the multisensory inputs that the brain receives.

A common illustration of just how flexible the sense of our body is comes from changes in the brain’s representation of the body due to tool use. Humans, and some other animals, are able to use tools as additions to the body. When we use a long pole to retrieve an object we couldn’t otherwise reach, the pole becomes, in some sense, an extension of our body. Is this merely a poetic way of speaking, or does the brain actually incorporate the tool into its representation of the body? Studies of monkeys learning to use a rake to obtain distant objects show that this may be more than a mere metaphor. Multisensory brain cells respond both to touch on the hand or visual objects appearing near the hand. When the monkeys used the rake, these cells began to respond to objects appearing anywhere along the length of the tool, suggesting the brain represented the rake as actually being part of the hand.

One of the signature discoveries of cognitive neuroscience is that a structure called the hippocampus, deep within the brain, is intimately involved in creating memories. This fact was dramatically illustrated by a singular patient, Henry Molaison, who experienced severe epileptic seizures. In 1953, when Molaison was 27, doctors removed his hip­pocampus and nearby areas on both sides of his brain. The operation controlled his epilepsy, but at a price--from that time on, he was unable to remember the things that happened to him. He could learn skills, such as mirror writing, but would be puzzled by his expertise, because he could not recall having acquired it.

H.M., as he was known during his lifetime to protect his privacy, taught scientists three lessons. First, certain brain structures--the hippocampus and the amygdala, the brain’s emotion center--specialize in remembering. Second, there are different kinds of memory--the ability to recall facts, or personal experiences, or physical skills like riding a bike--each with its own properties. Third, memory is distinct from the brain’s intellectual and perceptual abilities.