Scientific American - Biology

Mine Injuries Rise Right after Daylight Saving Time

Fri, 12 Mar 2010 13:30:08 EST

Don’t forget to move your clocks forward this weekend. And then don’t forget to be more careful in the days after you adjust your clocks. Because a recent study found that the hour of lost sleep was related to increased job-related injuries. Probably because sleepy workers were less alert. The work appeared last September in the Journal of Applied Psychology . [ see http://bit.ly/coie2b ] [More]

Gene Target Beats Oil Remedy

Fri, 12 Mar 2010 09:00:00 EST

The 1992 tearjerker Lorenzo’s Oil told the true story of one family’s struggle to save their son from X-linked adrenoleukodystrophy (ALD), a deadly degenerative brain disease. Unfortunately, over the ensuing years, the oil of the film’s title, a dietary supplement, has not panned out as the cure many people hoped it would be. Now a paper in the November 2009 issue of Science suggests that the long-sought cure may come from gene therapy--a famously hyped approach to treatment that tragically caused the death of a teenage experimental subject in 1999.

Since then, however, researchers have continued to cautiously pursue gene therapy for certain disorders with known genetic origins. ALD, for instance, is caused by mutations in a gene called ABCD1, leading to unusually high levels of a type of fatty acid that damages the material insulating some neurons. It affects about one in 20,000 six- to eight-year-old boys, leading to death before adolescence. The main treatment is still bone marrow transplantation: a risky procedure that relies on finding a suitable donor, explains Patrick Aubourg, a neurologist at France’s INSERM research institute.

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MIND Reviews: The Other Brain

Fri, 12 Mar 2010 09:00:00 EST

The Other Brain: From Dementia to Schizophrenia, How New Discoveries about the Brain Are Revolutionizing Medicine and Science by R. Douglas Fields. [More]

Condoms for the World Cup and other ways to keep HIV at bay

Fri, 12 Mar 2010 07:15:00 EST

MIAMI--In three months hundreds of thousands of soccer fans are expected to descend on nine South African cities for the 2010 World Cup. But for so many visitors going to a country where more than 10 percent of the population is estimated to have HIV/AIDS, many public health experts are worried that the event will kick off a spike in transmission. South Africa, in turn, has responded by requesting one billion condoms for the year (many of which will be supplied by the U.K.)--more than twice as many as usual, the BBC noted . [More]

Researchers Gain New Insights into the Mystery of Thalidomide-Caused Birth Defects

Thu, 11 Mar 2010 14:00:00 EST

Half a century ago, thousands of pregnant women in 46 countries took a drug for morning sickness that would later be discovered to cause severe malformations in developing fetuses. Worldwide, roughly 10,000 affected children nicknamed "thalidomide babies" were born with multiple defects, including the characteristic shortened upper limbs (a condition known as phocomelia, Greek for "seal limbs"), before the drug was discontinued in 1961 after four years on the market.

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New Hope for Battling Brain Cancer (preview)

Thu, 11 Mar 2010 09:00:00 EST

In May 2006 Dwayne Berg woke up on a gurney in a Seattle emergency room, an IV in his arm and a team of doctors and nurses working him up. The last thing the 42-year-old financial executive could remember was running on a treadmill at his gym, part of his regular fitness regimen. He had suffered a seizure and tumbled off the machine, and although he had not hurt himself in the fall, doctors had asked for an MRI scan of his brain to see if they could find a cause for the seizure.

They did, and the news was not good: the scan showed a large mass in the left frontal lobe that turned out to be a malignant glioma, a brain cancer that is almost invariably fatal. Berg underwent standard treatment: an operation to remove the tumor, followed by chemotherapy and radiation to eradicate any cancer cells that might remain.

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Divining the Right Drug

Thu, 11 Mar 2010 09:00:00 EST

Imagine suffering from the crushing weight of major depression, then finally getting diagnosed and starting treatment with a drug--only to realize after two months that the medication, despite its unpleasant side effects, is not alleviating your depression. Unfortunately, this experience is far from rare: more than two thirds of patients with depression have no luck with the first medication they are prescribed and must also endure the withdrawal effects that come with discontinuing a drug before trying a new one. Finding the right treatment can prove a lengthy, painful process of trial and error. A new technology, however, may bypass this ordeal by gauging very early in a treatment regimen how well a drug is working based on the patient’s brain waves.

The technology, called quantitative electroencephalography (QEEG), measures a person’s brain-wave pattern with EEG and then compares it with a database of normal samples to detect abnormal function. In a study published in the September 2009 issue of the journal Psychiatry Research , scientists used QEEG to record brain activity in subjects with major depressive disorder before they began treatment, after one week on an antidepressant and after eight weeks on the drug--the period it takes such drugs to achieve full effect. Changes in the QEEG readout after just one week of medication predicted 74 percent of the time whether patients would experience either a recovery or a remission of symptoms by the end of eight weeks.

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Malaria rates drop in the Americas, but travelers still worry

Thu, 11 Mar 2010 08:00:00 EST

MIAMI--Malaria continues to be a global scourge, sickening some 300 million to 500 million people annually. Most of the resulting one million to three million malaria deaths occur in regions where it is highly endemic, such as sub-Saharan Africa and parts of south Asia. [More]

TB or Not TB?: Novel Detector Could Shorten Testing Times, Aid Treatment Efforts

Wed, 10 Mar 2010 15:30:00 EST

Tuberculosis is a serious public health challenge in the developing world, where the infection claims roughly two million lives each year, according to the World Health Organization (WHO) . Yet the disease, which is a leading killer of patients with HIV/AIDS, is cumbersome to detect, resulting in delayed or inappropriate treatment, greater spread of the infection and preventable deaths. [More]

Few Studies Compare the Efficacy of Medical Treatments

Wed, 10 Mar 2010 10:00:00 EST

The forward momentum of medical progress is manifest, it could be argued, in the $50 billion spent in 2008 on pharmaceutical research and development in the quest to bring new drugs to market. But little scientific or governmental infrastructure exists to ensure that each new treatment is actually an improvement over existing therapies--and to tease out what therapies are best for which patients. [More]

Chimps Talk with Their Hands

Wed, 10 Mar 2010 09:00:00 EST

The origins of language have long been a mystery, but mounting evidence hints that our unique linguistic abilities could have evolved from gestural communication in our ancestors. Such gesturing may also explain why most people are right-handed.

Researchers at the Yerkes National Primate Research Center recently examined captive chimpanzees and found that most of them predominantly used their right hand when communicating with one another--for example, when greeting another chimp by extending an arm. The animals did not show this hand preference for noncommunicative actions, such as wiping their noses. Such lateralized hand use suggests that chimpanzees have a system in their left brain hemisphere that is coupled to the production of communicative gestures, says study author William Hopkins. The same cerebral hemisphere is host to most language functions in humans, which hints that an ancestral gestural system could have been the precursor for language, he says.

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Why is talking with gestures easier than talking without them?

Wed, 10 Mar 2010 09:00:00 EST

Why is talking along with gestures so much easier than trying to talk without gesturing? -- Lionel Halvorsen, Cornith, Tex.

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One's Enough: People Who Donate a Kidney Live Just as Long as Those Who Don't

Wed, 10 Mar 2010 07:00:00 EST

Every 30 minutes, all of the blood in our bodies is filtered through two fist-size kidneys. But diseases such as diabetes can cause them to fail, leading to a build-up of chemicals in the blood that without dialysis (mechanical blood filtration) or a kidney transplant would be fatal. And the wait for a new kidney can be long, unless someone you know is willing to give one of theirs to you. [More]

Smokestash Industry: ARPA-E Seeks Breakthroughs in Carbon Capture Technology

Tue, 09 Mar 2010 15:01:00 EST

WASHINGTON--Every second, our bodies capture carbon dioxide in our tissues, transport it via the blood, and dump it in the lungs from where it is exhaled. This unconscious process is yet another way humans contribute to the accumulation of the greenhouse gas in the atmosphere--albeit in a minuscule volume compared with burning fossil fuels . The key to this metabolic process is an enzyme called carbonic anhydrase and it's efficiency at capturing and releasing CO2 is what human engineers want to mimic at the power plant scale. [More]

Trichodesmium : The world's most famous nitrogen fixer

Tue, 09 Mar 2010 11:42:00 EST

Editor's Note: Journalist and crew member Kathryn Eident and scientist Jeremy Jacquot are traveling on board the RV Atlantis on a monthlong voyage to sample and study nitrogen fixation in the eastern tropical Pacific Ocean, among other research projects. This is the sixth blog post detailing this ongoing voyage of discovery for ScientificAmerican.com .

Imagine you’re in space, floating high above the Earth. Picture the world’s oceans, glimmering sapphire under the heat of the sun and the protection of the ozone layer. Look closer, there’s a patch of brown in the middle of all that blue. It’s a bloom of phytoplankton called Trichodesmium , a “world famous” nitrogen fixer. [More]

Does Getting Fat Protect against Fat?

Tue, 09 Mar 2010 08:10:08 EST

Everyone knows that obesity is bad for your health. Packing on the pounds, we’re told, leads to all sorts of medical problems: high cholesterol, insulin resistance, greater risk of diabetes and heart disease. But researchers at the University of Texas Southwestern Medical Center see things a little differently. In a paper in the journal Trends in Endocrinology and Metabolism [see http://bit.ly/bKaP33 ], they argue that being fat can actually protect us from these disorders. [More]

Seeing the Little Picture: Novel Nanocoating Gives Atomic Force Microscope Users a Better Look at Individual Molecules

Mon, 08 Mar 2010 15:20:00 EST

Spotting a disease in its earliest stages can help to facilitate its treatment greatly, yet telltale clues are often hidden at a scale too small to study accurately. This hindrance has some researchers looking for ways to use high-powered atomic force microscopes (AFMs) to study individual molecules for disease markers [More]

Chameleons' tongues still snappy in cool temperatures

Mon, 08 Mar 2010 15:01:00 EST

When the weather cools, ectothermic (cold-blooded) animals slow down, which should be good news for their potential prey. But the colorful chameleon has found a way to keep feeding at top speeds even in lower temps: an elastic-tissue tongue, which unlike regular muscles, can uncoil nearly as fast in lower temperatures as it can in warmer ones. [More]

Accents Trump Skin Color

Mon, 08 Mar 2010 09:00:00 EST

Children, like adults, use three visible cues--race, gender and age--to arrange their social world. They prefer to make friends with kids similar to them on these traits. New research shows that verbal accents may be equally important in guiding youngsters’ social decisions--in fact, accents may be even more important than race.

Working at Harvard University, developmental psychologist Katherine D. Kinzler and her colleagues first showed American five-year-olds photographs of different children paired with audio clips of voices and asked which ones they preferred as a friend: a child who spoke English, one who spoke French, or one who spoke English with a French accent. Even though the subjects understood the French-accented English, they were almost four times more likely to choose the native English speaker as a friend.

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Worm Charmers (preview)

Mon, 08 Mar 2010 08:00:00 EST

If you happen to be hiking in the right part of Florida at dawn, you might catch the sound of a predator hidden in the vegetation. Surely an alligator must be the source of these calls, you say to yourself. But the sound does not come from an alligator, or a mother bear, or some newly introduced predator from the Amazon. It comes from a human predator--a “worm grunter.”

Worm grunters have mastered the art of charming worms out of their burrows so they can be collected and sold as bait. First, the hunters pound a stob, or wooden stake, into the soil, and then they rub the stake with a flat piece of metal called a rooping iron. The vibrations resonate through the ground. In response, hundreds of large earthworms emerge, some as far as 12 meters from the baiter.

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