MIT discovers chemical basis of fear

MIT researchers just published a paper in Nature which describes how to reduce “learned fear” in mice by manipulating molecular pathways. They suggest this as a way of treating emotional disorders. Useful if you have emotionally disturbed mice in your lab.

Of course, you wouldn’t want drugs that can eliminate all fear – it’s too useful a survival mechanism.

Otherwise, soldiers might behave like Dave Lister, in the Red Dwarf episode “Polymorph“. The crew meets a creature that feeds on negative emotion. After it sucks all the fear out of Lister, he volunteers to strap on a neutron bomb and go after the beast. Hilarity ensues.

Old chips on the space station

Over the weekend, Russian cosmonauts were able to restart two flight control computers on the International Space Station that had been crashing for the past few days. They tracked the problem down to a faulty surge protector which they were able to bypass. Props to those resourceful Russians, but it doesn’t give you much confidence in the ISS electronics. Especially since if they had not been able to fix the computer glitch, they would have had to evacuate the station.

Turns out that those computers (made in Germany) are a vintage design, made from 12-year old computer chips.

The computers use radiation-hardened ERC32 three-chip processors that came from the factory in 1995 or so. The chips had to go through a grueling round of tests, during which some serious floating-point glitches were identified and fixed. Then they were incorporated into the DMS-R computers that went up with the Russian-built Zvezda module in 2000.

Go another level deeper, and you’ll find that the ERC32 chips are based on the SPARC V7 chip architecture, which was pioneered by Sun Microsystems and came out in 1986.

The software running on those chips has a California connection as well: It’s written on top of the VxWorks operating system, produced by Wind River Systems in Alameda, Calif. VxWorks, a Unix-like real-time programming platform, is a popular choice for spacecraft software: It was used on the 1997 Mars Pathfinder mission as well as NASA’s Stardust probe and the still-operating Mars Exploration Rovers.

How stem cells protect neurons

Primate Parkinson’s Treatment Reveals New Side of Stem Cells

While most scientists are struggling to change stem cells into the types of cells they need — neurons, insulin-producing cells, heart cells, etc. — the new work shows that stem cells can perform the remarkable task of saving damaged cells.

[Researchers] injected stem cells taken from the brains of 13-week-old aborted human fetuses into African green monkeys with damaged dopamine-producing brain cells.

Dopamine is a neurotransmitter that affects motion and balance. The death of so-called dopaminergic neurons has been linked to Parkinson’s disease, an incurable neurodegenerative disorder that affects about one million Americans.

At the time of the injections, the monkeys couldn’t feed themselves or walk without assistance, and alternated between periods of absolute stillness and uncontrollable tremors. Two months after the treatment, they were able to walk and eat. The tremors had disappeared.

“The behavioral improvement was very impressive,” Langston said.

But far from turning into a mass of brand-new dopamine-producing neurons, most of the [stem cells] clustered around existing neurons, protecting them from further damage and rejuvenating those that had deteriorated.

Four months after the injection, the effects started to wear off. The transplants’ declining effectiveness over time may also indicate that the monkeys’ immune systems rejected them. That would require transplant recipients to take immunosuppressant drugs — but in a medical catch-22, the drugs could prevent the stem cells from working.

Aliens and global warming

A friend recently sent me a copy of Aliens Cause Global Warming , a speech that author Michael Crighton delivered at Caltech in 2003. In it, he argues that climate science is fraudulent, motivated by politics rather than facts.

Crighton is obviously a smart man, and holds strong opinions. Unfortunately he uses the very tactics that he attacks in others. Rather than examining the underlying science, he uses oratory and analogy to justify his own beliefs.

He uses a lot of analogy to disparage climate science. He sets up straw men and lumps together very different research fields under the rubric of “fraudulent science”. (SETI, “Nuclear Winter”, and climate science are all equivalent to him). But he doesn’t actually analyze the current research or predictions of climate science.

He correctly notes that scientific theories must be testable. But then he dismisses all computer climate models, because some early predictions could not be substantiated. But that is to misunderstand the scientific process. Every good scientist proposes hypotheses that initially cannot be tested. And many of those hypotheses turn out to be wrong. But we don’t dismiss a researcher for making incorrect hypotheses. Her next hypothesis might turn out to be correct. And that speculation and testing is at the heart of the scientific method.

Crichton’s also seems not to understand some fundamental issues about climate research:

Nobody believes a weather prediction twelve hours ahead. Now we’re asked to believe a prediction that goes out 100 years into the future? And make financial investments based on that prediction? Has everybody lost their minds?

This is the classic fallacy of confusing weather with climate. Weather might actually be chaotic, and therefore long term weather forecasting isn’t very accurate. But climate is by definition the behavior of an environment over a very long time, which averages out short term weather fluctuations. As such, climate models are more accurate over the long term (decades or centuries) than over the next few years.

References:

Never eat anything bigger than your head

Back in college, the head of the Lab for Computer Science had a reputation for agressively pursuing grants and equipment. One of my professors used to joke: “If you offer Prof. Brown five pounds of bat guano, he’ll immediately ask for ten”.
Turns out, most people behave the same way. According to Cornell Prof. Brian Wansink, author of “Mindless Eating”, you can get people to eat really old, stale popcorn, as long as you give them a big enough tub of the stuff. And people will always eat more if you serve food on bigger plates.

His overarching conclusion is that our decisions about eating often have little to do with how hungry we are. Instead, we rely on cues like the size of a popcorn bucket — or the way we organize our refrigerator — to tell us how much to eat.
The scariest part is that most of us think we are immune to these hidden persuaders.

Mr. Wansink and his team were so taken aback by the results of their experiments on the shape of glasses that some of them went home and replaced the squat glasses they owned with tall, skinny ones. Mr. Wansink also uses dinner plates from the 1940s, which have the double advantage of being smaller and being more interesting than your typical Crate and Barrel fare.

Eating disorders: cause and effect

Eating disorders are a big problem in our society, especially among young women. Recorded cases have doubled in the U.S. since the 1960s. A recent article in Scientific American, “Through a Glass, Darkly“, discusses some of the causes.

It’s hard to know exactly how many people suffer from eating disorders. The article claims about 4% of women will suffer from clinical anorexia nervosa or bulimia nervosa in their lifetime. Another 2 to 5% of Americans will have a binge-eating disorder in any 6 month period.

And what causes these problems? A lot of people rightly blame media for promoting malnourished waifs as the ideal body image. This sets impossible goals, for women to look like the thinnest 5% of society. Yet while many women are influenced by those external images, recent studies say that those who suffer from eating disorders are more affected by their own faulty self-image.

A faulty body image–rather than an exaggerated ideal–is crucial to the development of eating disorders.

What lies behind a distorted body image? To answer this question, Vocks’s team took photographs of 56 people suffering from eating disorders and 209 healthy subjects used as controls. The scientists then asked the test subjects to adjust their images on a computer screen until they “recognized” themselves. Additionally, they asked both groups to give their virtual “me” the figure that they wished they had.
Whereas all the respondents had similar notions of an “ideal” figure, the bulimics and anorexics all significantly overestimated their real body mass. In contrast, the subjects who were not suffering from eating disorders believed that they were slimmer than they actually were.

Another trigger for eating disorders is “frequent and extreme dieting”. This confuses the body’s “hunger-satiety system”, leading to faulty perceptions and behavior. Ironically, dieting is also the best predictor of future weight gain. Dieting is worse than useless.

A child’s upbringing can also increase risk. Eating disorders often occur in well-off, well educated families. Yet when parents set high standards, the children feel pressure to excel, to be “model students” and lead perfect lives as adults. That’s always an unattainable goal. Conversely, a good relationship between parents and children balances security and independence. This promotes a healthy self-image. Without that positive influence, children are at greater risk of eating disorders and drug addiction.

What’s the prognosis? Not so good. About 5% of anorexic women die from the disease. Fully one quarter remain chronic anorexics for the rest of their life. A third regain some weight, but continue to have badly distorted body self-images. Only about 30% of anorexic women recover fully.

The situation is a bit better for bulimics. Half of those who get treatment recover from the disease. The other half continue to binge and purge for the rest of their life, which often causes chemical imbalances, digestive tract damage, and increased risk of heart attacks.

Dieting is worse than useless

We often hear that most people who diet eventually gain the weight back, (and then some). In fact, a new study from UCLA concludes that most people would be better off not dieting at all.

“Their weight would be pretty much the same, and their bodies would not suffer the wear and tear from losing weight and gaining it all back.”

People on diets typically lose 5 to 10 percent of their starting weight in the first six months, the researchers found. However, at least one-third to two-thirds of people on diets regain more weight than they lost within four or five years, and the true number may well be significantly higher, they said.

“Several studies indicate that dieting is actually a consistent predictor of future weight gain,” said Janet Tomiyama, a UCLA graduate student of psychology and co-author of the study. One study found that both men and women who participated in formal weight-loss programs gained significantly more weight over a two-year period than those who had not participated in a weight-loss program, she said.

So if dieting is counter-productive, what’s the alternative?

“Eating in moderation is a good idea for everybody, and so is regular exercise,” Mann said. “That is not what we looked at in this study. Exercise may well be the key factor leading to sustained weight loss. Studies consistently find that people who reported the most exercise also had the most weight loss.”

Update: A paper written by the UCLA researchers is available on their website: Medicare’s search for effective obesity treatments.

Faith-based reasoning

An administration official who censored and excised scientific reports on climate change has been defending himself before of a House committee this week.

A House committee released documents Monday that showed hundreds of instances in which a White House official who was previously an oil industry lobbyist edited government climate reports to play up uncertainty of a human role in global warming or play down evidence of such a role.

Mr. Cooney [was] chief of staff of the White House Council on Environmental Quality. Before joining the White House, he was the “climate team leader” for the American Petroleum Institute, the main industry lobby.

He was hired by Exxon Mobil after resigning in 2005 following reports on the editing in The New York Times. The White House said his resignation was not related to the disclosures.

Mr. Cooney said his past work opposing restrictions on heat-trapping gases for the oil industry had had no bearing on his actions once he joined the White House. “When I came to the White House,” he testified, “my sole loyalties were to the president and his administration.”

With this president and administration, isn’t that the same as loyalty to the oil industry?

Mr. Cooney, who has no scientific background, said he had based his editing and recommendations on what he had seen in good faith as the “most authoritative and current views of the state of scientific knowledge.”

The hearing also produced the first sworn statements from George C. Deutsch III, who moved in 2005 from the Bush re-election campaign to public affairs jobs at NASA. There he warned career press officers to exert more control over James E. Hansen, the top climate expert at the space agency.

Mr. Deutsch resigned last year after it was disclosed that he had never graduated from Texas A&M University, as his résumé on file at NASA said. He has since completed work for the degree, he said Monday.

Graphene dreams

Researchers have developed a transistor from graphene membrane, a “new class of carbon allotrope”. And no, I don’t know what that means either. But it sure sounds promising:

Researchers at the University of Manchester, working with a group at the Max Planck Institute in Germany, claim to have created transistors that are just one atom-thick and less than 50 atoms wide from a new class of material.

The substance, dubbed graphene, is described as a two-dimensional material that exhibits exceptionally high crystal and electronic quality, and the researchers claim has numerous potential applications in condensed matter physics and electronics.

The resulting transistor is way smaller than silicon transistors, requires less charge to control, and could be much faster. There’s only one small hitch.

They caution there is still some way to go to create a working chip from graphene single-electron transistors, with etching being a particular area for future work.

Professor Geim indicated graphene based circuits would not come of age before 2025 and till then silicon based devices would predominate.