Archive for September, 2012

Under Controlled: Why the New GMO Panic Is More Sensational Than Sense

By Guest Blogger | September 21, 2012 10:29 am

Scicurious is a PhD in Physiology, and is currently a postdoc in biomedical research. Follow on Twitter @Scicurious and read her blogs at Scientific American and at Neurotic Physiology.

A new toxicology study states that rats eating genetically modified food and the weedkiller Roundup develop huge tumors and die. But many scientists beg to differ, and a close look at the study shows why.

Genetically modified organisms (GMOs) have always been a controversial topic. On the one hand are the many benefits: the higher crop yields from pesticide- and insect-resistant crops, and the nutritional modifications that can make such a difference in malnourished populations. On the other side is the question that concerns many people: We are modifying the genes of our food, and what does that mean for our health? These are important question, but the new study claiming to answer them misses the mark. It has many horrifying pictures of rats with tumors, but without knowledge about the control rats, what do those tumors mean? Possibly, nothing at all.

The recent study, from the Journal of Food and Chemical Toxicology has fueled the worst fears of the GMO debate. The study, by Italian and French groups, evaluated groups of rats fed different concentrations of maize (corn) tolerant to Roundup or Roundup alone, over a two year period, the longest type of toxicology study. (For an example of one performed in the U.S., see here.) The group looked at the mortality rates in the aging rats, as well as the causes of death, and took multiple samples to assess kidney, liver, and hormonal function.

The presented results look like a toxicologist’s nightmare. The authors reported high rates of tumor development in the rats fed Roundup and the Roundup-tolerant maize. There are figures of rats with visible tumors, and graphs showing death rates that appear to begin early in the rats’ lifespan. The media of course picked up on it, and one site in particular has spawned some reports that sound like mass hysteria. It was the first study showing that genetically modified foods could produce tumors at all, let alone the incredibly drastic ones shown in the paper.

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Using Science to Sniff out Science That’s Too Good to Be True

By Neuroskeptic | September 19, 2012 9:15 am

Neuroskeptic is a neuroscientist who takes a skeptical look at his own field and beyond at the Neuroskeptic blog

Fraud is one of the most serious concerns in science today. Every case of fraud undermines confidence amongst researchers and the public, threatens the careers of collaborators and students of the fraudster (who are usually entirely innocent), and can represent millions of dollars in wasted funds. And although it remains rare, there is concern that the problem may be getting worse.

But now some scientists are fighting back against fraud—using the methods of science itself. The basic idea is very simple. Real data collected by scientists in experiments and observations is noisy; there’s always random variation and measurement error, whether what’s being measured is the response of a cell to a particular gene, or the death rate in cancer patients on a new drug.

When fraudsters decide to make up data, or to modify real data in a fraudulent way, they often create data which is just “too good”—with less variation than would be seen in reality. Using statistical methods, a number of researchers have successfully caught data fabrication by detecting data which is less random than real results.

Most recently, Uri Simonsohn applied this approach to his own field, social psychology. He has two “hits” to his name, and more may be on the way.

Simonsohn used a number of statistical methods but in essence they were all based on spotting too-good-to-be-true data. In the case of the Belgian marketing psychologist Dirk Smeesters, Simonsohn noticed that the results of one experiment conducted by Smeesters were suspiciously “good”: They matched with his predictions almost perfectly.

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CATEGORIZED UNDER: Top Posts

For Stealthy Electric Cars, Auditory Illusions Could Save Lives

By Mark Changizi | September 13, 2012 9:30 am

Mark Changizi is an evolutionary neurobiologist and director of human cognition at 2AI Labs. He is the author of The Brain from 25000 FeetThe Vision Revolution, and his newest book, Harnessed: How Language and Music Mimicked Nature and Transformed Ape to Man.”


The silent purr of an electric car is a selling point over the vroom of a gasoline engine, but it comes with an undesirable side effect: An electric car can pounce on unsuspecting passerbys like a puma on prey. In fact, the NHTSA found that hybrid electric cars are disproportionately dangerous to pedestrians. To deal with this problem, it has been proposed that sound be added to hybrid and electric vehicles, whether it be bird-songs or recordings of someone making “vroom vroom” sounds.

In this light, I wondered whether it might be possible to add “smart sound” to these dangerously quiet cars destined to rule the road in the near future. The solution, I realized, might come from faster-than-light-speed objects on the moon. I’ll get to this crazy-sounding part in a bit.

The Melody of Movement

In setting out to solve this problem, I reasoned that when electric cars are moving very fast they make enough sound to be heard due to the rumblings of the car parts. It’s when they’re moving at lower speeds that they’re most perilous, because at these speeds they’re most silent. Therefore, if electric cars are to be fitted with some sound, it should be designed to work even at lower speeds—or, especially at lower speeds.

Next question was, What sort of sound do we want on slowish, stealthy electric cars? To answer this, it helps to grasp the sorts of cues your auditory system uses for detecting the movement of objects in your midst.

The most obvious auditory cue is that nearer objects are louder, and so when you hear a moving object rising in loudness, you know it’s getting closer.

But that’s not the most important auditory cue. To illustrate why, imagine walking along a curb with traffic approaching and passing you from behind. The important observation here is that when this happens you aren’t in the least worried. Even without seeing the car, you know it’s merely passing you despite the massive crescendo in its sound. Why?

Doppler shift illustration
The Doppler shift changes the observed pitch of the siren as the car moves.

You know the car isn’t going to hit you because of its pitch. Due to the Doppler shift, this car has a falling pitch, and this falling pitch contour tells your brain unambiguously that, although the car is going to get arm-reachably close, it is going to pass you rather than collide with you. If it were going to collide with you, its pitch would be high and constant—that’s the signature of a looming collision.

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CATEGORIZED UNDER: Mind & Brain, Technology, Top Posts

The Internet Pulses With the Rhythms of Human Life

By Neuroskeptic | September 11, 2012 9:30 am

Neuroskeptic is a neuroscientist who takes a skeptical look at his own field and beyond at the Neuroskeptic blog

Life is dominated by the Earth’s cycles. Day and night, spring and autumn, change the environment in so many ways that almost all organisms regulate their activity to keep up with time and the seasons. Animals sleep, and many hibernate, moult, and breed only at certain times of the year. Plants time the growth of seeds, leaves, fruit and shoots to make the most of the weather.

But what about humans? We sleep, and women menstruate, but do other biological cycles affect our behavior? The Internet has offered researchers a unique resource for answering this question.

For example, according to research published recently in the Archives of Sexual Behavior from American researchers Patrick and Charlotte Markey, Americans are most likely to search for sex online during the early summer and the winter.

The authors looked at the Google Trends for a selection of naughty words and phrases, and this revealed a pretty marked 6 month cycle for searches originating from the USA, with two yearly peaks in the search volumes. The words were related to three categories: pornography, sex services (e.g. massage parlors), and dating websites.

Google Trends searches for 'pornography' related words over time
Google Trends searches for pornography-related words over time

This image shows the graph for pornography searches—the grey line—with an idealized six-month cycle also shown for comparison, the black line. The data show a strong twice-yearly peak. The picture was similar for two other categories of sexual words: prostitution and dating websites.

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The Limits of Science—and Scientists

By Guest Blogger | September 7, 2012 11:19 am

Ananyo Bhattacharya is the chief online editor of Nature magazine.

“About what one can not speak, one must remain silent.” The last line of Ludwig Wittgenstein’s Tractatus tends to resonate with scientists, sceptics, atheists, and other fans of rationality. If your thought cannot be articulated sensibly in plain language then you had better keep it to yourself. Written amid the slaughter of World War I, the book became central to the Vienna Circle, a group of philosophers who sat around the Café Centrale in the 1920s discussing which statements could be boiled down into verifiable empirical claims and those that could not. The latter, which included all of metaphysics and theology, they dismissed as meaningless nonsense. When the group finally convinced a reluctant Wittgenstein to visit them, he was so exasperated with their philosophy, logical positivism, that he took to turning his chair to the wall and reading Rabindranath Tagore poetry out loud during their meetings. They had misunderstood him, Wittgenstein explained. The ethical convictions, values and metaphysical ideas they had busily classified as “nonsense” were not worthless. In fact, they were the most important concerns in life.

I was reminded of Wittgenstein recently, when I read the firestorm of online criticism that followed the publication of a column in Nature magazine by Daniel Sarewitz, co-director of the Consortium for Science, Policy and Outcomes at Arizona State University.

In the piece, inspired by a visit to the Angkor temples in Cambodia and gamely entitled “Sometimes science must give way to religion,” Sarewitz drew some parallels between science and religion. (Note, however, that he did not support the misguided idea that science and religion were the same, or that science was nothing more than a belief system.) Worse, in many people’s eyes, was that he went further and argued that science alone is not enough—humanity will always need other ways of understanding the world. Citing the recent discovery of the Higgs boson, Sarewitz says:

“For those who cannot follow the mathematics, belief in the Higgs is an act of faith, not of rationality…in practical terms, the Higgs is an incomprehensible abstraction, a partial solution to an extraordinarily rarified and perhaps always-incomplete intellectual puzzle. By contrast, the Angkor temples demonstrate how religion can offer an authentic personal encounter with the unknown.”

I have my own problems with the piece. But the vehemence of the attack on Sarewitz would have made anyone think he had advocated teaching creationism in science classes while smacking Richard Dawkins around the head with a copy of the Holy Bible.

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CATEGORIZED UNDER: Top Posts

NASA’s Key to Efficient Mars Landings: Reduce, Reuse, Recycle

By Guest Blogger | September 5, 2012 11:27 am

Amy Shira Teitel is a freelance space writer whose work appears regularly on Discovery News Space and Motherboard among many others. She blogs, mainly about the history of spaceflight, at Vintage Space, and tweets at @astVintageSpace.

Last week, NASA announced its next planetary mission. In 2016 the agency is going back to the surface of Mars with a spacecraft called InSight. The mission’s selection irked some who were hoping to see approval for one of the other, more ambitious missions up for funding: either a hopping probe sent to a comet or a sailing probe sent to the methane seas of Saturn’s moon Titan. Others were irked by NASA’s ambiguity over the mission’s cost during the press announcement.

An artist’s rendition of InSight deploying its seismometer and heat-flow experiments on Mars.

InSight is part of NASA’s Discovery program, a series of low-cost missions each designed to answer one specific question. For InSight, that question is why Mars evolved into such a different terrestrial planet than the Earth, a mystery it will investigate by probing a few meters into the Martian surface. The agency says InSight’s selection was based on its low cost—currently capped at $425 million excluding launch costs—and relatively low risk. It has, in short, fewer known unknowns than the other proposals.

But while InSight costs less than half a billion itself, the total value of the mission by the time it launches will be closer to $2 billion. How can NASA get that much zoom for so few bucks? By harnessing technologies developed for and proven on previous missions. The research, development, and testing that has gone into every previous lander take a lot of guesswork out of this mission, helping it fly for (relatively) cheap.

Aside from the Moon, Mars is the only body in the solar system that NASA has landed on more than once. With every mission, the agency learns a little more, and by recycling the technology and methods that work, it’s able to limit expensive test programs. This has played no small part in NASA’s success on the Red Planet thus far. When it comes to the vital task of getting landers safely to the surface, NASA has been reusing the same method for decades. It has its roots way back in the Apollo days.

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CATEGORIZED UNDER: Technology, Top Posts
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