Scientific American

A Q&A with Ian Hacking on Thomas Kuhn's Legacy as "The Paradigm Shift" Turns 50

Fri, 27 Apr 2012 13:45:00 EST

Scientific American 's review of Thomas Kuhn's The Structure of Scientific Revolutions in 1964 ended with the pat pronouncement that the book was "much ado about very little." The short piece, which appeared two years after the initial publication of Structure as a monograph in the International Encyclopedia of Unified Science , discarded as unoriginal Kuhn's critique of the positivist argument that science progresses relentlessly forward toward the truth.

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Will Organic Food Fail to Feed the World?

Wed, 25 Apr 2012 13:01:00 EST

Food for hungry mouths, feed for animals headed to the slaughterhouse, fiber for clothing and even, in some cases, fuel for vehicles--all derive from global agriculture. As a result, in the world's temperate climes human agriculture has supplanted 70 percent of grasslands, 50 percent of savannas and 45 percent of temperate forests. Farming is also the leading cause of deforestation in the tropics and one of the largest sources of greenhouse gas emissions , a major contributor to the ongoing maul of species known as the " sixth extinction ," and a perennial source of nonrenewable groundwater mining and water pollution.

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Readers Respond to "The Coming Mega Drought" and Other Articles

Fri, 20 Apr 2012 12:00:00 EST

SCREENING STATS [More]

Fossil Free: Microbe Helps Convert Solar Power to Liquid Fuel

Fri, 30 Mar 2012 10:01:00 EST

A new " bioreactor " could store electricity as liquid fuel with the help of a genetically engineered microbe and copious carbon dioxide. The idea--dubbed " electrofuels " by a federal agency funding the research--could offer electricity storage that would have the energy density of fuels such as gasoline. If it works, the hybrid bioelectric system would also offer a more efficient way of turning sunlight to fuel than growing plants and converting them into biofuel .

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How to Use Light to Control the Brain

Tue, 27 Mar 2012 12:00:00 EST

In the film Amèlie , the main character is a young eccentric woman who attempts to change the lives of those around her for the better. One day Amèlie finds an old rusty tin box of childhood mementos in her apartment, hidden by a boy decades earlier. After tracking down Bretodeau, the owner, she lures him to a phone booth where he discovers the box. Upon opening the box and seeing a few marbles, a sudden flash of vivid images come flooding into his mind. Next thing you know, Bretodeau is transported to a time when he was in the schoolyard scrambling to stuff his pockets with hundreds of marbles while a teacher is yelling at him to hurry up.

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The Ballooning Brain: Defective Genes May Explain Uncontrolled Brain Growth in Autism

Thu, 22 Mar 2012 17:00:00 EST

As a baby grows inside the womb, its brain does not simply expand like a dehydrated sponge dropped in water. Early brain development is an elaborate procession. Every minute some 250,000 neurons bloom, squirming past one another like so many schoolchildren rushing to their seats at the sound of the bell. Each neuron grows a long root at one end and a crown of branches at the other, linking itself to fellow cells near and far. By the end of the second trimester, neurons in the baby's brain have formed trillions of connections, many of which will not survive into adulthood--the least traveled paths will eventually wither. [More]

A Neuroscientist's Quest to Reverse Engineer the Human Brain

Tue, 20 Mar 2012 11:00:00 EST

What makes us who we are? Where is our personal history recorded, or our hopes? What explains autism or schiziphrenia or remarkable genius? Sebastian Seung argues that it’s all in the connections our neurons make. In his new book, Connectome , he argues that technology has now reached a point where it is conceivable to start mapping at least portions of the connectome. It’s a daunting task, he says, but without it, neuroscience will be stuck. He answered questions from Mind Matters editor Gareth Cook.

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Blocking HIV's Attack (preview)

Thu, 15 Mar 2012 08:00:00 EST

A little more than three years ago a medical team from Berlin published the results of a unique experiment that astonished HIV researchers. The German group had taken bone marrow--the source of the body’s immune cells--from an anonymous donor whose genetic inheritance made him or her naturally resistant to HIV. Then the researchers transplanted the cells into a man with leukemia who had been HIV-positive for more than 10 years. Although treatment of the patient’s leukemia was the rationale for the bone marrow transplant therapy, the group also hoped that the transplant would provide enough HIV-resistant cells to control the man’s infection. The therapy exceeded the team’s expectations. Instead of just decreasing the amount of HIV in the patient’s blood, the transplant wiped out all detectable traces of the virus from his body, including in multiple tissues where it could have lain dormant. The German researchers were so surprised by the spectacularly positive results that they waited nearly two years before publishing their data.

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Search for Faster, Better Antidepressants Makes Progress (preview)

Wed, 07 Mar 2012 08:00:00 EST

A young woman who calls herself blueberryoctopus had been taking antidepressants for three years, mostly for anxiety and panic attacks, when she recounted her struggles with them on the Web site Experience Project. She said she had spent a year on Paxil, one of the popular SSRIs (selective serotonin reuptake inhibitors), but finally stopped because it destroyed her sex drive. She switched to Xanax, an antianxiety drug , which brought back her libido but at the cost of renewed symptoms. Then Paxil again, then Lexapro (another SSRI), then Pristiq, a member of a related class of antidepressants, the SNRIs (serotonin and norepinephrine reuptake inhibitors). At the time of the post, she was on yet another SSRI, Zoloft, plus Wellbutrin (a cousin of SNRIs that affects the activity of dopamine as well as norepinephrine), which was intended to counteract the sexual side effects of Zoloft. “I don’t notice much of a difference with the Wellbutrin, but I’m on the lowest dose now,” she wrote. “I’m going back to my psychiatrist next week, so maybe he’ll up it. Who knows.”

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Structured Unlearning: Marijuana May Impair Memory via the Brain's Non-Firing Cells

Thu, 01 Mar 2012 12:00:00 EST

In a 2006, season 2 episode of The Office entitled "Drug Testing," Dwight Schrute interrogates his fellow employees about the partially smoked joint he found in the parking lot. Dwight is determined to identify the culprit, but Jim Halpert turns the tables: [More]

New Energy-Dense Battery Could Enable Long-Distance Electric Cars

Mon, 27 Feb 2012 18:01:00 EST

NATIONAL HARBOR, Md.--A company founded in the Palo Alto public library has taken a dose of government money and technology and turned it into the most energy-dense battery ever. Envia System's new lithium-ion battery packs roughly twice as much energy per gram as present batteries, the company will announce here at the third annual summit of the Advanced Research Projects Agency--Energy ( ARPA–e ). [More]

Readers Respond to "Can We Feed the World and Sustain the Planet?" and Other Articles

Fri, 17 Feb 2012 08:00:00 EST

ENTOMOLOGICAL ETHICS [More]

Top Multitaskers Help Explain How Brain Juggles Thoughts (preview)

Thu, 16 Feb 2012 11:00:00 EST

“Any man who can drive safely while kissing a pretty girl is simply not giving the kiss the attention it deserves,” Albert Einstein is purported to have said. The quote acknowledges a fundamental characteristic of human attention. Sometimes there simply is not enough of it to go around. [More]

Jumping Genes in the Brain Ensure That Even Identical Twins Are Different (preview)

Tue, 14 Feb 2012 10:45:00 EST

Your brain is special.

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Cracks in the Plaques: Mysteries of Alzheimer's Slowly Yielding to New Research

Mon, 06 Feb 2012 05:30:00 EST

This has been a big week in Alzheimer's news as scientists put together a clearer picture than ever before of how the disease affects the brain. Three recently published studies have detected the disease with new technologies, hinted at its prevalence, and described at last how it makes its lethal progress through the brain.

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Designers of Exotic Materials Learn New Tricks from Animals (preview)

Thu, 26 Jan 2012 08:45:00 EST

Among the first things you notice when you step into the corner office of Harvard University professor Joanna Aizenberg are the playthings. Behind her desk sit a sand dollar, an azure butterfly mounted in a box, a plastic stand with long fibers that erupt in color when a switch is pulled, and haphazard rows of toys. Especially numerous are the Rubik’s cubes--the classic three-by-three, of course, but also ones with four, five, six and even seven mini cubes along each edge. An eight-year-old would be in heaven.

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Scientists Manipulate and Erase Memories (preview)

Thu, 26 Jan 2012 08:00:00 EST

Joël Coutu knelt on the cold cement floor of the pet supply store he managed in Montreal, his wrists bound behind him with telephone wire. He could feel the barrel of a pistol pressed against the back of his neck. “You’re lying!” the gunman screamed. “And I am going to blow your head off.”

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Genetically Engineered Stomach Microbe Converts Seaweed into Ethanol

Thu, 19 Jan 2012 15:01:00 EST

Seaweed may well be an ideal plant to turn into biofuel. It grows in much of the two thirds of the planet that is underwater, so it wouldn't crowd out food crops the way corn for ethanol does. Because it draws its own nutrients and water from the sea, it requires no fertilizer or irrigation. Most importantly for would-be biofuel-makers, it contains no lignin--a strong strand of complex sugars that stiffens plant stalks and poses a big obstacle to turning land-based plants such as switchgrass into biofuel .

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How Scientists Are Tackling the Bed Bug Nightmare (preview)

Thu, 19 Jan 2012 08:00:00 EST

The elderly man lived by himself in a low-income apartment near Cincinnati. But he was not alone. After dark the bed bugs would emerge from his recliner and tattered box-spring mattress to feed on his blood. Judging from the thousands of insects I found in his home, I would venture that it had been this way for many months. Imprisoned by poverty and infirmity, the man had nourished generations of these pests, enduring their bites night after night while their numbers swelled.

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The Impracticality of a Cheeseburger

Sun, 15 Jan 2012 08:00:00 EST

What does the cheeseburger say about our modern food economy? A lot, actually. Over the past several years blogger Waldo Jaquith ( http://waldo.jaquith.org ) set out to make a cheeseburger from scratch, to no avail. “Further reflection revealed that it’s quite impractical--nearly impossible--to make a cheeseburger from scratch,” he writes. “Tomatoes are in season in the late summer. Lettuce is in season in spring and fall. Large mammals are slaughtered in early winter. The process of making such a burger would take nearly a year and would inherently involve omitting some core cheeseburger ingredients. It would be wildly expensive--requiring a trio of cows--and demand many acres of land. There’s just no sense in it.”

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