Category: Science

Quotation of the day

…the GM [genetically modified] food controversy is a feature of societies for which food is not a life-and-death issue. In India, where people literally starve to death…up to 60 percent of fruit grown in hill regions rots before it reaches market. Just imagine the potential good of a technology that delays ripening, like the one used to create the Flavr-Savr tomato. The most important role of GM foods may lie in the salvation they offer developing regions, where surging birthrates and the pressure to produce on the limited available arable land lead to an overuse of pesticides and herbicides with devastating effects upon both the environment and the farmers applying them; where nutritional deficiencies are a way of life and, too often, of death; and where the destruction of one crop by a pest can be a literal death sentence for farmers and their families…The opposition to GM foods is largley a sociopolitical movement whose arguments, though couched in the language of science, are typically unscientific.

From James Watson’s recent DNA The Secret of Life, p.160, the book is also a good introductory read on DNA issues more generally.

By the way, here is a picture of aquarium fish, they are genetically modified to glow in the dark, thanks to Chris Mooney for the link and commentary.

The best new ideas in applied science

Read this feature article from Popular Science magazine, or just buy the December issue. My two favorite new products are the following:

1. Binoculars that repeat the last 30 seconds. Instant replay, right there in your hands, and only $600 from bushnell.com.

2. Speakers that know how to listen. The speakers can measure what kind of sound they are producing in a particular room, and adjust their output accordingly to sound even better, they are called Beolab 5. This item costs a steeper $16,000, I will buy them when they start paying bloggers, from Bang-Olufsen.

Alex will be interested to hear about the new “Lifeport Kidney Transporter,” see organ-recovery.com, now FDA-approved, which makes it easier to move kidneys around the world, the device makes a soon-to-be transplanted kidney last for 17 more hours than previous technologies.

Blood supply and the FDA

Have you ever heard of Chagas disease? It is rare in the United States but common in Latin America, where 18 million people are infected and 50,000 die of it every year. Some little thingie crawls down your mouth and sucks your blood when you are sleeping (lovely), beware the thatched hut, and next thing you know, maybe about ten or thirty years later, your weakened heart or organs explode. There is no known vaccine, cure, or treatment.

Chagas is now making its way into the United States blood supply. Ideally, all donated blood should be screened for Chagas. But, can you believe this, the FDA needs to approve all blood tests of this kind. They haven’t approved any test for Chagas, nor have they shown much urgency in this regard, here is the full story.

About 30 tests are currently in use in Latin America, but none would appear to meet the FDA’s accuracy guidelines. In the meantime it appears someone would prefer that we have no test at all.

The New York Times put it as follows:

The failure of the blood industry and its regulators to develop a test since it was endorsed by a Blood Products Advisory Committee in 1989 seems to be a combination of bureaucratic inertia and divided responsibility for such a decision. Blood banks cannot use a test that the F.D.A. has not approved. The agency usually defers to its advisory committees, which have many experts from blood banks as members.

“It’s a political process that is not always fully engaged,” said Dr. Stuart J. Kahn of the Infectious Disease Research Institute, a Seattle group hunting cures for tropical diseases.

Whatever you think of the FDA as a regulator of drugs, this kind of bureaucratic control is hard to understand. Now it is longer enough for you to beware the thatched hut, you have to worry about the blood supply as well.

Being a bigot is exhausting, and makes you stupider

People with implicit racial prejudices are left mentally exhausted after interacting with someone from a different race, perhaps because they are trying to quell their feelings.

The new study, the first of its kind, shows that areas in the brain associated with self-control light up in white people with implicit racial biases when they are shown images of black people.

Furthermore, the study showed that the level of this brain activity correlated very closely with poor performance in a test of thinking ability given right after a face-to-face interview with a black person. The researchers believe this indicates that the subject’s mental resources have been temporarily drained by their efforts to suppress their prejudices.

Here is the full story.

A good mom should be sociable

At least in the world of baboons:

Baby baboons born to outgoing mums who enjoy hanging out with other females are considerably more likely to survive their crucial first year than infants born to less friendly mothers…

And the difference is a big one:

Susan Alberts, at Duke University in North Carolina, and one of the research team was surprised by the significance of sociability. “Eight per cent of infant survival is explained by sociality,” she told New Scientist. That is “striking”, she explains, because “we wouldn’t expect to have a large amount of variation that is deterministic – things that a mother can actually control – it’s amazing.”

Here is the full story. In my family of primates, the wife/mother is definitely the sociable one, at night I like to stay at home and write my blog or read.

What is love?

When you first fall in love, you are not experiencing an emotion, but a motivation or drive, new brain scanning studies have shown.

The early stages of a romantic relationship spark activity in dopamine-rich brain regions associated with motivation and reward. The more intense the relationship is, the greater the activity.

Here is the best part, or I suppose I should say the worst part:

Early on in a relationship, the images showed that the brain seems to be very focused on planning and pursuit of pleasurable reward, says Fisher, mediated by regions called the right caudate nucleus and right ventral tegmentum. The same regions become active when a person enjoys the pleasure of eating chocolate, she adds…There are also patterns that resemble aspects of obsessive compulsive disorder.

Here is the story from New Scientist, here is related research on the links between love and OCD. The research also suggests gender differences; male love has more to do with lust than does female love.

A monocausal theory of the aggregate divorce rate?

The divorce rate is almost perfectly predictable from the proportion of men to women in the population. In 1920, when the annual divorce rate was eight per one thousand married women, there were 104 males for every female. By 1980 the tables had turned, and there were only ninety-five males for every one hundred females, and the divorce rate had risen to twenty-three per one thousand married women. The sex ratio has remained virtually unchanged for the past thirty years and is paralleled by a steadily high divorce rate. The correlation betwee the population sex ratio (or number of males per one hundred females) and the divorce rate at four-year intervals between 1896 and 1992 was -.91, indicating that changes in the number of men relative to women accounts for 83 percent of the changes in divorce rate.

From Nigel Barber’s The Science of Romance who, on this claim, cites his own Why Parents Matter.

Can this be true? If it is such a neat fact, why have I never heard it before?

A good bit of web searching yielded surprisingly little enlightenment. One Amazon reviewer writes:

On page 150, Barber refers to a 1983 book purporting that the increasing divorce rate was due to a shortage of marriagable men. That was true in 1983. Barber fails to note that by 1987 the marriageable male/female ratio reversed, and we’re now in a “women shortage” era.

Point well taken, we should consider the sex ratio of marriageable people, not the overall sex ratio. More significantly, the general rate of American divorce is rising over time. The sex ratio has been moving in favor of more women as well, at least until recently, perhaps because survival out of childhood depends less on parental discretionary investments, noting that many parents prefer boys to girls. So the correlation may be spurious, rather than representing causality.

The fact is intriguing, but so far it is not a good monocausal theory of the divorce rate.

Man vs Machine II

Regarding this week’s man vs machine chess match. Tyler writes:

I was surprised to see Kasparov favored. Once he lost to Deep Blue, the last big match (Kramnik vs. Deep Fritz) was a draw. I know it is not as simple as Moore’s Law, but hey, don’t these machines improve their game more rapidly than the human players do?

Indeed, they do. Deep Blue was a very expensive, very fast computer specialized for chess and capable of examining some 200 million positions per second. Fritz is no slouch but it is being run on a more or less ordinary four processor Xeon computer capable of analyzing 3 million moves a second. Fritz is thus about 70 times less powerful than Deep Blue. Yet because of improvements in algorithms, Fritz is almost certainly the better player. So the computer players have improved tremendously over the past 6 years – so much so that the computer side is no longer bothering to field its best against the weak humans!

Addendum: Here’s a graph, from Jeff Sonas, of the top computer player ratings versus the top human player. Although, it is true, as Sonas argues, that the best programs do not beat the very best human players but only draw consistently it may simply be inherent in chess that it is impossible or near impossible to beat someone who is playing at the very highest level (similarly it’s impossible for even a mediocre human player to lose in tic-tac-toe.) We should not conclude from this that the computers aren’t improving. Thanks to Nathan Stocker for the link.

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Greenhouse effect skeptics

Here is an entire web site devoted to skepticism about the greenhouse effect, and whether the burning of fossil fuels is at fault. It offers the latest scientific research on the skeptical side, excellent visuals, and regular updates. I am an agnostic on this issue, and underinformed most of all, but I do feel that this alternative point of view deserves a better hearing.

The future of energy

…the power generation capacity found under the hoods of cars in Germany or America is ten times that of all of the nuclear, coal, and gas power plants combined in those countries.

A compelling and clever fact. The author, Vijay Vaitheeswaran, argues that our energy future is one of decentralization, relative plenty, and lower levels of pollution. His new book is titled Power to the People: How the Coming Energy Revolution Will Transform an Industry, Change Our Lives, and Maybe Even Save the Planet.

We are told that the future will bring hydrogen fuel cells, micropower in lieu of a centralized power grid, and paeans to the visionary genius of Amory Lovins. I am all ready to sign up, except the evidence is missing, at least within the book. The author offers a compelling picture, and it may well be true. But if he is right, why isn’t the price of oil falling over the last few years? Will fuel cells really limit pollution, once we take into account the energy needed to construct the cells? What unknown contingencies could stop his predictions from coming true?

I recommend this book for its enthusiasm and sweeping vision. I also very much liked his treatment of the California power crisis, which is more sophisticated than Paul Krugman’s, among other interesting bits. But I am not yet ready to go short on the shares of either the power companies or the price of oil.

Can more rain make the road safer?

Here’s the scoop:

In an analysis of more than 1 million fatal crashes in 48 states, Daniel Eisenberg, a post-doctoral researcher at UC Berkeley’s School of Public Health, was surprised to find that the more it rained or snowed in a month, the fewer deadly traffic accidents there were. Specifically, in any given month, an additional 10 centimeters of rain is linked with a 3.7 percent decrease in the fatal crash rate.

“I had expected to see a positive relationship between the amount of precipitation and the rate of fatal traffic accidents, but my analysis revealed a more complex connection between the two,” said Eisenberg.

He also discovered that the risk of an accident on a rainy day increases with the length of the dry spell preceding it. If there has been rain or snow day after day, the danger due to wet conditions falls.

In other words, if you are used to dangerous roads in recent times, you will drive more carefully. But we are weak, feeble creatures who forget about past dangers all too quickly. Click here for the full story.

The researcher suggests an additional explanation for the phenomenon:

“Oil and debris accumulate on the road when it hasn’t rained for a while, making the roads slicker when it first starts to rain,”

Eisenberg finds another interesting result:

…overall, precipitation had a larger impact on nonfatal traffic accidents.

“For any given day in the state, on average, each centimeter of precipitation increases the risk of fatal crashes by about 1 percent, but for nonfatal crashes, the increased risk is 11 percent,” said Eisenberg.

So, on any given day, rain or snow will lead to increases in nonfatal injury crashes and fender benders much more so than to increases in accidents that involve death.

“People who slow down when the weather is bad may not slow down enough to avoid all crashes, but, on average, they at least reduce the severity of the collision,” said Eisenberg.

In other words, to kill yourself being drunk, very stupid, very unlucky, or a very bad driver are the critical ingredients, not the rain.

The origins of human freedom

I had lunch today with Paul Rubin, a very smart law and economics scholar who also likes chicken tacos. Paul has just published a book on the Darwinian origins of politics and human freedom.

Here is a very brief summary from Randall Parker at Futurepundit:

Rubin sees both the impulse for support of the welfare state and the opposition to high taxes and the resentment toward freeloaders as all consequences of Pleistocene adaptations. Helping others in tough times might lead to their helping you out at a later point. At the same time. food was too scarce to tolerate freeloading. Rubin also argues that libertarianism is contrary to human nature and that humans want to meddle in each others’ lives. Read the whole review. Very interesting.

He is referring to Denis Dutton’s recent review of the book on aldaily.com, worth reading as well. It also summarizes the book nicely and in much more detail.

Here is Parker’s provocative conclusion:

My guess is that the distribution of alleles for the desire to be altrustic or to enforce rules or to force people not to be freeloaders will be found to be different in different parts of the political spectrum. A lot of political divisions will turn out to be, at least in part, due to average differences in personality characteristics that have their origins in the Pleistocene era. my bet is that once people start genetically tinkering with their offspring purer forms of socialists, libertarians, social conservatives, and other political types will be born and the political divisions within some societies and between societies will become greater as a result.

On this point, I do suspect that much of our political orientation springs from our basic inborn temperament. Shouldn’t this make us more skeptical of any particular views we happen to hold? It may feel right to have those views, but hey, that would be a genetic accident, and not a reflection of which policies are actually good for us.