science big and small

Bjorn Lomborg was one of the first high-profile "climate change skeptics". In 2001, he argued in his book The Skeptical Environmentalist that fighting global warming would be a waste of money.

Now, in a new book Smart Solutions to Climate Change, Lomborg is calling climate change "undoubtedly one of the chief concerns facing the world today", and calling for a carbon tax to collect $50 billion a year.

The Week has a brief on him and five other climate "skeptics" who have come around.

Scientific American reports on research showing that a diet high in saturated fat causes the brain to become resistant to leptin and insulin, hormones that let us know when our need for food has been fulfilled.

The research in question was done on rats, and it's always tricky to extrapolate such work to humans; and there are serious ethical issues with killing rats to find our why humans become such pigs when they eat cows. But the phenomenon in question is expected to apply to humans as well.

The researchers also performed in vitro experiments where they directly observed palmitic acid (a common saturated fatty acid) inhibiting the signaling of nerve cells exposed to insulin.

On the other hand, oleic acid, a monounsaturated fatty acid, did not produce this result.

What evolutionary mechanism might produce such a result, that too much fat in the system actually tells the body to increase rather than decrease food uptake? Here's what one leptin expert quoted in the SciAm article says:

If you're a bit of a math geek, you may know Newton's method for finding the square root of a number. It's fairly simple; you start with a guess, divide the number by the guess, and take the average of the quotient and the guess as a new guess. (Remember, to take the average of two numbers, we add them and divide by two.) Lather, rinse, repeat, and you'll get closer and closer the the root.

For example, let's say I want to find the square root of 110 -- which is going to be close to 10, but let's say I don't know that, so I pick 55 as my guess. 110/55=2, so my next guess is (55+2)/2=28.5. Getting closer already.

110/28.5 is 3.8596 (we'll say four places is enough), so our next guess is (28.5+3.8596)/2=16.1798.

110/16.1798 is 6.7986, so our next guess is (16.1798+6.7986)/2=11.4892.

110/11.4892 is 9.5742, so our next guess is (11.4892+9.5742)/2=10.5317.

Let's do one more round: 110/10.5317=10.4447, (10.5317+10.4447)/2=10.4882

You can see that we're getting close and closer to the real value, which is around 10.4881, and that we could repeat this over and over to get as close as we want.

That's pretty cool, but you can't easily use this to get a specific number of digits of accuracy in the result. Plus, you have to keep doing division. Yuck. I used a calculator (actually, bc, the Unix desktop calculator) above, but what if we were doing this by hand?

I've had this trace of memory stuck in the back of my head for about thirty years, that I once saw a method for computing square roots digit-by-digit, that looked something like long division. And finally, thanks to Google, I found it again!

In honor of the birthday of Percy Bysshe Shelley, here's a fascinating article I just stumbled upon about his attitude toward science:

From the days at Eton however when the embryo poet set trees on fire with gunpowder and a burning glass, or "raised the devil" -- and his tutor -- with electric batteries; even from earlier days, when he brought stained hands and singed clothing to the nursery at Field Place and tried to "shock" his little sisters into a cure for chilblains; Shelley's great interest lay in chemical and physical experiments that gave free scope to fancy and were too primitive to call for the exactness alien to the romantic nature of the experimenter.

During his short stint at Oxford, Shelley wrote:

"What a mighty instrument would electricity be in the hands of him who knew how to wield it? What will not an extraordinary combination of troughs of colossal magnitude, a well arranged system of hundreds of metallic plates, effect? The balloon has not yet received the perfection of which it is surely capable; the art of navigating the air is in its first and most helpless infancy. It promises prodigious facilities for locomotion, and will enable us to traverse vast tracts with ease and rapidity, and to explore unknown countries without difficulty. Why are we still so ignorant of the interior of Africa ? -- why do we not despatch intrepid aeronauts to cross it in every direction, and to survey the whole peninsula in a few weeks?"

Ah, Shelley: nonviolent anarchist, atheist, vegetarian, poet, worshiper of Pan and fan of the Goddess, and now lover of technology when applied for humane ends. Is there anything you did that I don't love?

Reuters is reporting on a study that claims to show that low-carb diets can have an advantage over low-fat ones for heart health. I'm sure that fans of Atkins-style diets, the folks who want to believe that bacon is a health food, will be touting the results. (If you actually read the article, you'll see that the small differences in HDL levels and blood pressure are no big deal, but I doubt that will stop low-carb fans from latching on to the headline.)

What this study actually shows, however, is just how utterly bad some nutrition research can be.

What was this "low-fat" diet like? The supposed low-fat diet had a target of 55 percent of calories from carbs, 15 percent from protein and 30 percent from fat.

But 30 percent of calories from fat is not a low-fat diet. The 30% recommendation was based on what was seen as an achievable goal in a fat-addicted culture, not as a health optimum; it's like, "hey, can you cut the cigarettes down to a pack a day?"

The average intake is estimated at 35.4% calories from fat in industrialized nations, so 30% is only a little below that. (I've seen estimates that the American average is 45%, but that only shows how fat-addicted we are, not that 30% is low.) In developing nations it's 19.6% -- close to the 20% estimated for Late Paleolithic humans. That's much higher than other primates, and almost certainly well in excess of our needs, but we might call 20% a moderate-fat diet. An actual low-fat diet like the Ornish plan gets around 10% of its calories from fat.

Considering 30% to be a "low-fat" diet is an all-too-common flaw in diet studies. But this one addds another big whopper. Where did the low fat, high carb diet get its carbs? Were those on this arm of the study getting complex carbs from vegetables and whole grains? Well, no: study participants

were instructed to start exercising regularly -- mostly brisk walking -- and learned tactics for weight management, such as writing down what they ate every day and setting reasonable short-term goals (if you normally eat 10 candy bars a week, for instance, first try cutting out a couple rather than going cold-turkey.)

(Emphasis added.) So it seems sugar was on the menu, even in high amounts.

Meanwhile, the low-carb group got their small ration of carbs from a strictly regimented selection of vegetables, fruits, grains, and dairy.

So the "low-fat" diet here was a high-fat, sugar-laden, nutritional nightmare, and the "low-carb" one was an even higher-fat, sugar-free nutritional nightmare. It's not surprising that the low-carb diet, bad as it is, might look good in comparison -- even with the side effects this study found common: hair loss, bad breath, and constipation.

And this passes for science?

Somehow, a hysterical fringe-science blog post by Terrence Aym -- a grade-A teabagger nutball who has previously argued that states should seceed from the U.S. and claimed that North Korea was behind the Deepwater Horizon explosion -- has managed to capture the imaginations of many scientifically illiterate journalists and bloggers.

Aym takes the fact there are elevated levels of methane in the vicinity of the Deepwater Horizon leak, combines it with a gross misunderstanding of a speculative theory by Gregory Ryskin about methane and the Permo-Triassic Extinction, and concludes that "OMG we're all gonna die!".

It is, of course, a load of hooey. Sorry, but we won't get out of this so easily as the world ending; we're going to have to do the hard work of cleaning up the mess. io9.com does a fine job of debunking the nonsense, with several good links.

Richard Feynman was a Nobel Prize winning physicist and one of the most brilliant minds of the twentieth century. He was also a drummer, an artist, a ladies' man, and a raconteur. His book Surely You're Joking, Mr. Feynman! is a collection of stories about his adventures. This excerpt, where Feynman takes a graduate-level class in biology while he's at Princeton, just to see what's going on in other fields, is one of my favorites.

The next paper selected for me was by Adrian and Bronk. They demonstrated that nerve impulses were sharp, single-pulse phenomena. They had done experiments with cats in which they had measured voltages on nerves.

I began to read the paper. It kept talking about extensors and flexors, the gastrocnemius muscle, and so on. This and that muscle were named, but I hadn't the foggiest idea of where they were located in relation to the nerves or to the cat. So I went to the librarian in the biology section and asked her if she could find me a map of the cat.

"A map of the cat, sir?" she asked, horrified. "You mean a zoological chart!" From then on there were rumors about some dumb biology graduate student who was looking for a "map of the cat."

When it came time for me to give my talk on the subject, I started off by drawing an outline of the cat and began to name the various muscles.

The other students in the class interrupt me: "We know all that!"

"Oh," I say, "you do? Then no wonder I can catch up with you so fast after you've had four years of biology." They had wasted all their time memorizing stuff like that, when it could be looked up in fifteen minutes.

I've previously reported on Bisphenol-A (BPA), the ubiquitous endocrine-disrupting chemical found in water bottles and many other forms of packaging and linked to breast cancer, insulin resistance, miscarriage, obesity, prostate enlargement, early onset of sexual maturation, and other problems.

The latest: new research shows that BPA can cross the placenta from mother to fetus, where it can affect development during a particularly vulnerable period. And other new research suggests that fetal exposure to BPA and other endocrine disruptors can increase the risk of breast cancer later in life.

More and more I suspect that future generations will look back at our cavalier use of endocrine disruptors the way we look at the Romans' use of lead, and wonder: WTF were they thinking?

Research published in the International Journal of Biological Sciences looks at the effects of feeding three strains of genetically-modified corn -- two of which produce Bacillus thuringiensis derived pesticides ("Bt"), and one of which is "Roundup ready", meaning that it contains derivatives of this herbicide -- to rats.

Looking at data that was actually provided by Monsanto (though in some cases, only after disclosure was mandated by courts), they found that

...in the three GM maize varieties that formed the basis of this investigation, new side effects linked to the consumption of these cereals were revealed, which were sex- and often dose-dependent. Effects were mostly concentrated in kidney and liver function, the two major diet detoxification organs, but in detail differed with each GM type. In addition, some effects on heart, adrenal, spleen and blood cells were also frequently noted. As there normally exists sex differences in liver and kidney metabolism, the highly statistically significant disturbances in the function of these organs, seen between male and female rats, cannot be dismissed as biologically insignificant as has been proposed by others. We therefore conclude that our data strongly suggests that these GM maize varieties induce a state of hepatorenal toxicity. This can be due to the new pesticides (herbicide or insecticide) present specifically in each type of GM maize, although unintended metabolic effects due to the mutagenic properties of the GM transformation process cannot be excluded. All three GM maize varieties contain a distinctly different pesticide residue associated with their particular GM event (glyphosate and AMPA in NK 603, modified Cry1Ab in MON 810, modified Cry3Bb1 in MON 863). These substances have never before been an integral part of the human or animal diet and therefore their health consequences for those who consume them, especially over long time periods are currently unknown.

Monsanto, of course, being one of the finest examples of pure concentrated evil on the planet, looked at this same data and applied weaker statistical methods to say that everything is hunky-dory.

I've previously reported on the bad science around flu vaccine recommendations, and how the flu in general and H1N1 specifically have apparently been overblown as health threats.

(Please note that my considerations here are limited to the flu. This is not an "anti-vaccine" rant; I got a Tdap shot a few months ago -- and felt like crap for a day or two, but given the seriousness of diphtheria, pertussis, and tetanus and the effectiveness of those vaccines, it was worth it.)

Now, the BMJ reports on the conflicts of interest and lack of transparency around the World Health Organization's declaration of the H1N1 pandemic and its recommendations for responses.

Most shockingly, the WHO actually changed the definition of a pandemic in May 2009 so that H1N1 would qualify, removing the qualification that an outbreak must cause "enormous numbers of deaths and illness". And it estimated that 2 billion H1N1 cases were likely -- 1 out of 3 human beings on the whole planet -- even after the winter season in Australia and New Zealand showed that only about one to two out of 1000 people were infected.

It did this while taking advice from people with financial and research ties with Big Pharma companies that produced antivirals and vaccines; one researcher who wrote key guidelines had been paid by Roche and GlaxoSmithKline.