PNAS

Multitaskers are Lousy Multitaskers

September 30th, 2009 | 1 Comment | Source: CNN, PNAS

Are you reading this while checking email, chatting on IM, waiting for your purchase to clear PayPal and signing your mum’s birthday card?

JoethemultitaskerIf so, please set all that aside for a moment and take note.

A study published in the Proceedings of the National Academy of Science suggests that people who tend to involve themselves in multiple media-oriented activities at the same time perform relatively poorly on tests requiring them to shift attention from one task to another.

To reach these conclusions, Clifford Nass and colleagues at Stanford administered a survey to 262 college students which elicited a history of media utilization and whether or not they tendened to engage in multiple tasks simultaneously.

They collected information regarding the use of computer games, online video and audio, TV, cell phones, text and instant messaging, and computer software like word processors.

After completing the survey, the students underwent a battery of tests in which they had to evaluate certain colored triangles while ignoring other ones, categorize words, alternate between classifying numbers and letters, and press a certain button when they saw a match between 2 symbols presented at different times.

The scientists found that heavy multitaskers executed these functions more slowly than with those who rarely used more than one medium at a time. The multitaskers, it turned out, were more easily distracted by irrelevant information because they retained it in their short-term memories for a longer period of time.

The difference amounted to about a half-second delay on most tests, a difference large enough to cause noticeable problems in everyday life. (more…)

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Here Come the Women

July 10th, 2009 | No Comments | Source: NY Times, PNAS

Prospects at major research universities have improved for female scientists and engineers, although they still struggle to match male peers when it comes to salary, according to a report published by the National Research Council.

nowaboutthatraise“Men and women faculty in science, engineering and mathematics have enjoyed comparable opportunities,” in recent years, the report concluded.

In particular, women who apply for university positions, promotion and tenure are at least as likely to succeed as men.

A great equalizer in encouraging women to apply for jobs, the report found, was the presence of women on the committees tasked to fill the positions.

The Council, part of the National Academy of Science, was convened by Congress. It surveyed biology, chemistry, civil and electrical engineering, mathematics and physics. It relied on faculty interviews and data from federal registries and professional societies.

It was chaired by Claude Canizares, the VP for research at MIT, and Sally Shaywitz, a learning expert at Yale.

Meanwhile, a second report in the Proceedings of the National Academy of Sciences shows that the gender-related achievement gap in mathematics has vanished of late.

“U.S. girls have reached parity with boys, even in high school and even for measures requiring complex problem solving,” reported Wisconsin University-based researchers Janet Hyde and Janet Mertz.

And, Laurence Summers take note, girls are catching up in the ranks of so-called math prodigies, a finding that undermines claims that profound mathematical talent is the biological destiny of males.

The Wisconsin researchers used data from the No Child Left Behind program and the National Assessment of Educational Progress. Gender-related differences were “close to zero in all grades,” they found, including high school where gaps had previously existed.

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Vitamins Mess with Exercise Benefits

June 11th, 2009 | No Comments | Source: NY Times, PNAS

In a scientific study sure to qualify for the Hall of Fame of Counterintuitive Results, scientists in Germany and Boston have concluded that people who exercise to reduce diabetes risk ought to avoid antioxidants like vitamins E and C. 
 
wtfMichael Ristow, a nutritionist at Jena University, Ron Kahn of the Joslin Diabetes Center and their colleagues published the mind-bending findings in the Proceedings of the National Academy of Sciences

At the moment, “get more exercise” is just about the first thing that pops out of clinicians’ mouths when advising patients how to mitigate the risk of diabetes.

But exercise stimulates glucose metabolism in muscle cells and an unavoidable byproduct of this biochemical cascade is the release of oxygen-based free-radicals that damage normal tissue.

The damage, dubbed oxidative stress, accumulates with age and some posit it contributes to many deleterious cellular phenomena that are observed with increasing age.

Since human tissue has only a limited capacity to combat oxidative stress, antioxidant vitamins, which combat oxygen-based free-radicals, would seem to be a perfectly reasonable supplement.

Not so, say the scientists. They asked young men to exercise while giving half of them vitamins C and E and the others placebos. The scientists subsequently measured insulin sensitivity and several indicators of oxidative stress.

The team found that in the group taking the vitamins, insulin sensitivity did not improve and the body’s natural defenses against oxidative stress were not activated.

They suggest that’s because the vitamins destroy the free-radicals, thereby short-circuiting the body’s normal response to exercise.

“If you exercise to promote health, you shouldn’t take large amounts of antioxidants,” Ristow told the New York Times. “Antioxidants…inhibit otherwise positive effects of exercise, dieting and other interventions.”

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Slumdog Begets Slumdog

May 4th, 2009 | No Comments | Source: Economist, PNAS

Virtually every nation on Earth struggles with endemic poverty.

Children of the poor are at greater risk for underachieving as adults regardless of the system of government where they live and the quantity and quality of both social services and educational systems available to them.

where'sournextmealcomingfrom?The problem has been poorly understood until, perhaps, now.

Three years ago, Martha Farah at the University of Pennsylvania demonstrated that the working memories of kids raised in poverty are smaller than those of middle-class children.

Working memory is the capacity to hang on to bits of information for current use; the items on a small shopping list, for example. It is required for solving problems and understanding language, and serves as a gateway to permanent memory.

Now, Cornell University’s Gary Evans and Michelle Schamberg have reported that Farah’s findings are almost certainly caused by the adverse effects of stress on brain development in children.

The scientists examined results from a longitudinal study of 195 participants of both sexes.

They assessed stress using a measure known as the allostatic load which combines the values of 6 parameters: systolic and diastolic blood pressure, serum levels of 3 stress-related hormones, and the BMI.

In all cases, higher values indicate more a more stressful life, and indeed poor kids had higher values than those in the middle class for all 6. (more…)

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The Devil in the Details

April 30th, 2009 | No Comments | Source: BurrillReport, PNAS

Michigan State University scientists have found that brand name information and marketing claims overshadow fine print safety warnings on OTC medications, despite Federal regulations requiring that display of the latter should be “prominent” and “conspicuous.” 
 
wherediputmyglasses?Laura Bix and colleagues used an eye-tracking device to quantify the visual inspection patterns of subjects as they scanned package labels on OTC pain killers and subsequently assessed the extent to which subjects could recall the information.

The scientists focused on five elements of the package label: brand name, the statement of claims such as “extra strength,” drug facts information, the child-resistant warning and the tamper-evident warning.
 
They observed that subjects focused primarily on the brand name and much less on the 2 warnings.  For example, 67% of the subjects were able to remember one or more brands they had observed during the study, but only 18% recalled alcohol-related warnings.

A dismal 8% remembered the warning that the product shouldn’t be used in homes where young children were around and not one single participant recalled the warning about tamper-evident features.
 
Part of the explanation, according to Bix and Co., is that the brand and product claims were more legible than the warning statements.

Their write-up appears in Proceedings of the National Academies of Science.

“To be effective, warnings about the lack of a child-resistant feature, or those that alert consumers to potential tampering of the product, need to be read and comprehended at the time of purchase,” Bix told BurrillReport.

“Little guidance exists from the federal government regarding what it means to be ‘prominent’ or ‘conspicuous,’ yet, this term is used quite frequently in the regulations that dictate labeling for a variety of product,” Bix added.

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That was quick

April 2nd, 2009 | No Comments | Source: BurrillReport, PNAS

Scripps Research Institute scientists may have overcome a significant drawback of vaccinations as a treatment strategy—the time lag from injection until immunity has developed.

itworked!They’ve named their new vaccination strategy “covalent immunization” and tested it on mice afflicted with either colon cancer or melanoma.

The technique involves injecting subjects with chemicals designed to stimulate an immune reaction, and following that with injections of other compounds, so-called “adapter molecules,” which recognize cancer cells.

The latter compounds then create covalent bonds with the antibodies generated by the first injection.
 
The newly formed molecules then lay low, bothering normal physiology not a bit while somehow not being metabolized or otherwise cleared from the body, until (in this case) a cancer cell pops up at which point they spring into action and the next thing you know you have a dead cancer cell.

Carlos Barbas and colleagues published their work in Proceedings of the National Academy of Science.

“The antibodies in our vaccine are designed to circulate inertly until they receive instructions from tailor-made small molecules to become active against a specific target,” Barbas told BurrillReport.

“Antibodies (would be) primed and ready to go. (The method) would apply whether the target is a cancer cell, flu virus, or a toxin like anthrax that soldiers or even civilian populations might have to face during a bioterrorism attack.”

Barbas wants to experiment with covalent immunization in cancers, HIV, and infectious diseases for which vaccines are not currently available.

“We believe that chemistry-based vaccine approaches have been underexplored and may provide opportunities to make inroads into intractable areas of vaccinology,” Barbas concluded.

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Global Warming Rocks

November 28th, 2008 | No Comments | Source: Economist, PNAS

Geologists know that when carbon dioxide contacts the igneous rock peridotite, a spontaneous chemical reaction results. The reaction produces limestone and eliminates carbon dioxide.

Carbon dioxide is a greenhouse gas, so people thought why not grind up some peridotite, transport it to power plants and line smokestacks with the stuff to trap CO2 before it’s released into the atmosphere?

A good thought, but one that proved too costly and energy intensive.

Now, a study published in the Proceedings of the National Academy of Sciences concludes that the miracle stone’s gas trapping abilities can be enhanced a million-fold by simple methods, and the whole CO2 sink idea suddenly has legs.

Peridotite normally resides in the Earth’s mantle 15 miles below the surface. Sometimes though, plate tectonic collisions push peridotite to the surface. That’s what happened eons ago in Oman which is now home to an exposed patch of peridotite the size of Massachusetts.

After 5 years of field work in the Omani desert, Peter Kelemen and Juerg Matter concluded that its peridotite patch is naturally absorbing 10,000 to 100,000 tons of carbon a year–far more than previously thought.

This means it may be feasible to pump CO2 from regional power plants to specially prepared peridotite fields resulting in “a low-cost, safe and permanent method to capture and store atmospheric CO2,” according to Kelemen.

The process would involve boring holes into the rock and injecting warm water containing pressurized CO2. Once started, the reaction would generate heat that would further accelerate the reaction. Fractures would form exposing new peridotite to the soda. The man-made gas trap would keep going as long as fresh CO2 was supplied.

The scientists assert that Omani peridotite alone can absorb some 4 billion tons of carbon a year—that’s 13% of the total spewed into the atmosphere each year.

Peridotite fields also exist in Papua New Guinea, Greece and Croatia. There are small deposits in the western United States as well.

And it turns out that ubiquitous basalt may have similar greenhouse gas gobbling characteristics. Scientists in Iceland are pursuing that lovely possibility right now.

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