science

His body mass index went from 28.8, considered overweight, to 24.9, which is normal. He now weighs 174 pounds.

But you might expect other indicators of health would have suffered. Not so.

Haub’s “bad” cholesterol, or LDL, dropped 20 percent and his “good” cholesterol, or HDL, increased by 20 percent. He reduced the level of triglycerides, which are a form of fat, by 39 percent.

That’s from this article on Mark Haub, a nutrition professor who spent two months eating… junk food:

For 10 weeks, Mark Haub, a professor of human nutrition at Kansas State University, ate one of these sugary cakelets every three hours, instead of meals. To add variety in his steady stream of Hostess and Little Debbie snacks, Haub munched on Doritos chips, sugary cereals and Oreos, too.

…Two-thirds of his total intake came from junk food. He also took a multivitamin pill and drank a protein shake daily. And he ate vegetables, typically a can of green beans or three to four celery stalks.

I got that link from this SBM article that debunks a lot of crap folk wisdom on diet (and endorses some of it), for instance:

Avoid chemicals, preservatives, and artificial sugar. This simply an appeal to the naturalistic fallacy. It’s not possible to avoid “chemicals” in your diet; chemicals ARE your diet. The same can be said for preservatives. Salt is a preservative. Added ingredients need to be evaluated on their own merits, not avoided wholesale. The same can be said for artificial sweeteners. Reno demonizes sugar substitutes claiming they “work against you just as much as white sugar does.” Yet here is no persuasive evidence to demonstrate that artificial sweeteners are harmful, or will compromise dietary goals. The same cannot be said for sugar.

Avoid all over-processed, refined foods, especially white flour and sugar. Here’s where we finally get into some specific dietary advice. This is largely reasonable, as heavily processed foods tend to be higher in salt and calories, and may also be less nutritious. There is is very little scientific debate that whole grain products are superior to those that contain mainly white flour, which is missing the most nutritious parts of the grain. There’s also good evidence to suggest many people obtain an excessive number of calories from sugar, and from refined carbohydrates in general. However, advising that all white flour and sugar be avoided is very difficult, and there’s no reason they cannot be consumed in moderation. What matters is the overall caloric balance.

Depend on fresh fruits and vegetables for fiber, vitamins, and enzymes. Fruits and vegetables are good sources of nutrients, fiber and vitamins. but so are other foods, such as grains. Insisting on “fresh” produce is unnecessarily restrictive, as frozen or canned versions can offer the same nutritional benefits.  Enzymes are large proteins that act as catalysts for biochemical reactions throughout the body – but our body produces what we need, and digests the ones we consume.

There’s more at the link.

Slate on Milk:

There are no written records from the period when humans invented agriculture, but if there were, they would tell a tale of woe. Agriculture, in Jared Diamond’s phrase, was the “worst mistake in human history.” The previous system of nourishment—hunting and gathering—had all but guaranteed a healthy diet, as it was defined by variety. But it made us a rootless species of nomads. Agriculture offered stability. It also transformed nature into a machine for cranking out human beings, though there was a cost. Once humans began to rely on the few crops that we knew how to grow reliably, our collective health collapsed. The remains of the first Neolithic farmers show clear signs of dramatic tooth decay, anemia, and low bone-density. Average height dropped by about 5 inches, while infant mortality rose. Diseases of deficiency like scurvy, rickets, beriberi, and pellagra were serious problems that would have been totally perplexing. We are still reeling from the change: Heart disease, diabetes, alcoholism, celiac disease, and perhaps even acne are direct results of the switch to agriculture.

…

The plot is still fuzzy, but we know a few things: The rise of civilization coincided with a strange twist in our evolutionary history. We became, in the coinage of one paleoanthropologist, “mampires” who feed on the fluids of other animals. Western civilization, which is twinned with agriculture, seems to have required milk to begin functioning. No one can say why. We know much less than we think about why we eat what we do. The puzzle is not merely academic. If we knew more, we might learn something about why our relationship to food can be so strange.

Nature has the scoop:

The usually quiet world of mathematics is abuzz with a claim that one of the most important problems in number theory has been solved.

Mathematician Shinichi Mochizuki of Kyoto University in Japan has released a 500-page proof of the abc conjecture, which proposes a relationship between whole numbers — a ‘Diophantine’ problem.

And this:

Conrad says that the work “uses a huge number of insights that are going to take a long time to be digested by the community”. The proof is spread across four long papers^1–4, each of which rests on earlier long papers. “It can require a huge investment of time to understand a long and sophisticated proof, so the willingness by others to do this rests not only on the importance of the announcement but also on the track record of the authors,” Conrad explains.

Mochizuki’s track record certainly makes the effort worthwhile. “He has proved extremely deep theorems in the past, and is very thorough in his writing, so that provides a lot of confidence,” says Conrad. And he adds that the pay-off would be more than a matter of simply verifying the claim. “The exciting aspect is not just that the conjecture may have now been solved, but that the techniques and insights he must have had to introduce should be very powerful tools for solving future problems in number theory.”

Here are some other fun tidbits. About the mathematician quoted in the article:

I personally know Brian Conrad (quoted in article). He has an encyclopedic knowledge of algebraic number theory and algebraic geometry, I would say that he’s in the top ten people worldwide who could reasonably assess whether Mochizuki’s proof is correct. And he has a great nose for bullshit, and little patience for it.
He is taking this claim seriously. He doesn’t necessarily believe it’s correct (presumably he’s a bit careful in what he says to the press), but he seems to think it has a shot, and is worth paying attention to.

Here’s the author’s wikipedia page (the days of prodigies sweeping the profession are clearly over).

And here is the abstract for the first of the papers (I hope my TeX rendering works with all this bizarro notation):

Abstract. The present paper is the first in a series of four papers, the goal of which is to establish an arithmetic version of Teichm¨uller theory for number fields equipped with an elliptic curve — which we refer to as “inter-universal Teichm¨uller theory” — by applying the theory of semi-graphs of anabelioids,
Frobenioids, the ´etale theta function, and log-shells developed in earlier papers by the author. We begin by fixing what we call “initial Θ-data”, which consists of an elliptic curve EF over a number field F, and a prime number l ≥ 5, as well as some other technical data satisfying certain technical properties. This data determines various hyperbolic orbicurves that are related via finite ´etale coverings to the once-punctured elliptic curve XF determined by EF . These finite ´etale coverings admit various symmetry properties arising from the additive and multiplicative structures on the ring Fl = Z/lZ acting on the l-torsion points of the elliptic curve.

We then construct “Θ±ell NF-Hodge theaters” associated to the given Θ-data. These Θ±ell NF-Hodge theaters may be thought of as miniature models of conventional scheme theory in which the two underlying combinatorial dimensions of a number field — which may be thought of as corresponding to the additive and multiplicative structures of a ring or, alternatively, to the group of units and value group of a local field associated to the number field — are, in some sense, “dismantled” or “disentangled” from one another. All Θ±ell NF-Hodge theaters are isomorphic to one another, but may also be related to one another by means of a “Θ-link”, which relates certain Frobenioid-theoretic portions of one Θ±ell NF-Hodge theater to another is a fashion that is not compatible with the respective conventional ring/scheme theory structures. In particular, it is a highly nontrivial problem to relate the ring structures on either side of the Θ-link to one another. This will be achieved, up to certain “relatively mild indeterminacies”, in future papers in the series by applying the absolute anabelian geometry developed in earlier papers by the author. The resulting description of an “alien ring structure” [associated, say, to the domain of the Θ-link] in terms of a given ring structure [associated, say, to the codomain of the Θ-link] will be applied in the final paper of the series to obtain results in diophantine geometry. Finally, we discuss certain technical results concerning profinite conjugates of decomposition and inertia groups in the tempered fundamental group of a p-adic hyperbolic curve that will be of use in the development of the theory of the present series of papers, but are also of independent interest.

Well, about time!

Much has been written (and published on this site) about the implausibility of chiropractic vertebral subluxation theory which proposes that a vertebral subluxation complex or a spinal joint dysfunction “may affect organ system function and general health.” Associated chiropractic gimmickry that might be harmful as well as a waste of time and money should be also be brought to the attention of concerned consumers. As a chiropractor (retired) who has renounced subluxation theory, it might be helpful to share my concerns about some dubious chiropractic methods that are foisted upon an unsuspecting public, unchallenged in the market place.

From the always awesome Science-Based Medicine.

A bioengineer and geneticist at Harvard’s Wyss Institute have successfully stored 5.5 petabits of data — around 700 terabytes — in a single gram of DNA, smashing the previous DNA data density record by a thousand times.

…

Scientists have been eyeing up DNA as a potential storage medium for a long time, for three very good reasons: It’s incredibly dense (you can store one bit per base, and a base is only a few atoms large); it’s volumetric (beaker) rather than planar (hard disk); and it’s incredibly stable — where other bleeding-edge storage mediums need to be kept in sub-zero vacuums, DNA can survive for hundreds of thousands of years in a box in your garage.

Here’s more.

Today I write an exam. It was originally scheduled for last Friday but my wife went into labor a few days before and I had to move it (using my laptop in the delivery room three hours before my son was born. Wife, incandescent with rage from pain: “WTF are you doing on your computer?!”).

Anyway, the exam isn’t until 5pm so I’ve got some time for a little sharpening up. And of course I turn to Barker:

If you can’t get in a full night’s sleep, you can still improve the ability of your brain to synthesize new information by taking a nap. In a study funded by NASA, David Dinges, a professor at the University of Pennsylvania, and a team of researchers found that letting astronauts sleep for as little as fifteen minutes markedly improved their cognitive performance.

The challenges that the brain had grappled with during the daytime replayed in the mind as the subject went to sleep… (S)ubjects who spent more time dreaming about the game demonstrated a greater improvement in their skills the next time they played than those whose brains hadn’t relived its experiences during sleep.

Ugh, I slept horribly last night because I strained an abdominal muscle playing soccer yesterday. I’m actually convinced it’s a studying injury triggered by the running around. Ok, nap today, got it.

Here’s some more interesting stuff:

Dement— one of the premier researchers in the history of sleep science who you may remember from an earlier chapter— received a commission from a company that had recently built a prototype of a high-tech mattress. Inside of it, warm air flowed through billions of tiny, ceramic beads. The end result was the feeling of a cushion built out of heated mud.“Everyone in our lab agreed that it was the most comfortable bed they had ever lain on,” Dement later noted. The company that hired him asked Dement to determine how well people slept on its product, which was expected to retail for several-thousand dollars, compared with a conventional mattress. To make the final result more dramatic, Dement decided to include a third option in his study: sleeping on a concrete floor with no padding. Volunteers gamely spent a night on each of the three, and Dement’s team later evaluated the results. “We were absolutely flabbergasted,” he wrote. There were no significant differences in the quality of a volunteer’s sleep or the total number of hours spent sleeping on the three surfaces.

A bit surprising, actually. I’ve slept on all manner of mattresses and agree that they probably don’t matter up to a point (I actually think that a concrete floor is better than a lot of soft mattresses out there). But wouldn’t the psychological effect alone of sleeping on a concrete floor make people uncomfortable? Questionable science!