Scientific American April 2010: On Newsstands March 23
The Latest in Science News
Sustainability: Living on a New Earth (p 53)
For centuries humans have used up every resource available on Earth, fundamentally altering the planet itself. As discussed in a special report in this month's Scientific American, "we've exhausted that strategy," turning our "natural planet into an industrialized one." The situation is not hopeless, however, and four different articles discuss the new thinking and bold actions necessary to guide humans on how to live on a new Earth.
Citing findings from a major international collaboration, Jonathan Foley discusses the "calculated" safe limits for key environmental processes, such as ocean acidification, and tackles the question of how close the planet may be to "failure". In a separate piece, Scientific American asks eight experts to spell out the solutions they think will be crucial in dealing with the environmental challenges ahead of us.
Bill McKibben tackles a bigger problem in his article, noting that "fixes could slow environmental degradation but might not solve the underlying cause," which he believes is "our relentless quest for economic growth". Finally, in an exclusive dialogue, Mark Fischetti challenges McKibben on how "realistic" his ideas are about giving up on economic growth to focus on maintaining our resources.
Perspective: Chemical Controls (p 28)
Congress needs to give the Environmental Protection Agency, the Food and Drug Agency and other executive bodies greater authority to test and regulate chemicals found in our everyday environment, argues this month's Scientific American Perspective piece. Thus far, federal agencies can often only offer warning to consumers rather than enforcing much needed restrictions on hazardous chemicals.
One case study of this is BPA—bisphenol A—a chemical used as the building block for the plastics in everything from eyeglasses to baby bottles. In fact, as the perspective piece notes, "93 percent of Americans have detectable levels of BPA by-product in their urine." Although BPA has been linked to various health problems, such as asthma, some cancers, and diabetes, it is still not regulated by any federal agency. And BPA is only one of several harmful chemicals that we are regularly exposed to, though much remains mysterious about the impacts of these chemicals thanks to a lack of testing.
The U.S. government has thus far been too slow in reforming its efforts to understand and better control chemicals and their human health impacts. It is time for a change, and "[it] should begin by reforming and strengthening the Toxic Substances Control Act to require reviews of chemicals for safety, force manufacturers to provide adequate health data on any chemical under review, and empower agencies to restrict or ban the sue of chemicals with clear evidence of harm.”
Neuroscience: Faulty circuits (p 44)
In the past, mental disorders were thought of, and treated as, strictly malfunctions of mind and behavior, in part because no physical damage that might explain them could be seen in the brain. Nowadays, writes Thomas R. Insel in this month’s issue of Scientific American, “scientific approaches based on modern biology, neuroscience and genomics are replacing nearly a century of purely psychological theories about mental illnesses." This dramatic shift is forcing psychiatrists to rethink both causes and cures for mental disorders.
Recent advances in neuroimaging technology in particular allow scientists to map neural activity levels and the connections between different parts of the brain, revealing entire "circuits" of interconnected brain regions that together generate normal cognitive functions—and whose malfunctioning could be the underlying source of the symptoms of many mental disorders.
Highlighting advances in the identification of such circuits linked to depression, obsessive compulsive disorder, and post-traumatic stress disorder, Insel explains how these new insights into the biology of mental disorders will lead to better, empirical methods of diagnosis and faster, more effective methods of prevention and treatment.
Feature: Regaining balance with bionic ears
Most people don’t notice their sixth sense—the sensation of how one’s head is oriented and moving when it is working normally—but for individuals with disorders affecting the parts of the ear that control balance and spatial perception, debilitating vertigo, chronic unsteadiness and blurred vision are the norm. Electronic implants in the inner ear may be able to help these individuals to regain their balance, as discussed by Charles Della Santina in this month’s Scientific American.
The implant, which contains small gyroscopes, records head movements in three dimensions, sending the corresponding signals to the nervous system. So far, the implants have shown great promise in animal experiments and experts hope that clinical testing will begin soon.
Richard Gannon, who lost much of his sense of balance six years ago after a viral illness, hopes to be first in the queue once the prostheses become available. The 57-year-old can no longer drive in the dark and his wavering walking leads people to assume he is drunk. “I’d give up my hearing if it would mean getting my balance back,” he said. “I’ll walk to the hospital if I have to.”
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