Via Kevin Drum:

Overturning a century of conventional medical wisdom, Japanese researchers reported Thursday that simple chest compressions without mouth-to-mouth ventilation save twice as many heart attack victims as traditional CPR.

What's not shocking here is that this only applies to people who are suffering a plain heart attack. Why? Such people can still breathe. As such, only chest compressions are needed to reestablish minimal circulation. For those people who are suffering respiratory arrest, forced breathing is still necessary.

From the same article, this is depressing:

As many as three-quarters of bystanders who observe a heart attack in a stranger decline to perform CPR, fearing infectious diseases.

That's just sad. You're more susceptible to diseases from all the bathroom doorknobs you touch. A single case of giving CPR to a stranger is not likely to give you anything, and nothing more than a cold in any case. This risk is worth it to save someone's life.

Article at L.A. Times

There's been a lot of hoo-haa about the so-called "obesity epidemic" in the U.S. It's never been clear to me how real or severe this is.

This animation from MSN (published a couple years ago) is the first thing I saw that really drove it home:

animated map of the obesity epidemic.

I'm going to try something new as a potential occasional feature of this blog. I continually seek to educate myself on matters of all sorts: I read ravenously not only from the news but from other sources of information, seeking to know more about the world we live in.

While I usually blog only about interesting new developments here, I thought it might be interesting to post about existing knowledge that I've recently discovered or re-discovered.

Today's topic is human physiology. Did you know the human body has two separate circulatory systems?

Everybody knows about the circulatory system: the heart, blood, arteries, veins etc. But most people have a less-strong grasp of the Lymphatic system. For myself, I knew that it existed, and that "lymph nodes" can swell up when you get sick, but beyond that I couldn't have told you much about it. Well, this morning I educated myself.

In short, the lymphatic system collects the clear liquid parts of the blood from where it leaks into the muscles and body tissues. It passes this towards central areas of the body, filters it for germs in the lymph nodes, and returns it to the bloodstream in a junction with an artery in your neck.

Lymph is essentially the clear component of blood, packed with extra immune cells. The lymphatic system is a network of vessels that transport lymph around the body. It largely accumulates in the tissue space between cells, where the clear blood plasma has leaked out of the circulatory system. Since the lymphatic system has no pump, the liquid flows slowly under low pressure from the collection points, and helped along by the squeezing action of muscle tissue. Flow is one-directional from lymph capillaries in the muscle and body tissues towards the central parts of the system.

The body produces a large number of immune cells (B- and T-lymphocytes) in the bone marrow, many of which get stored in the thymus, a gland in your neck. These enter the lymph system, circulate, and accumulate in the lymph nodes, which are essentially little spongy filter sacs filled with billions of immune cells. During infection, bacteria and viruses are drawn into the lymphatic system by liquid flow, where they drift into the nodes and are destroyed by lymphocytes and macrophages - think of the lymph nodes as little garbage disposers or waste treatment plants. You can now probably guess why the nodes swell when you get sick.

For more reading, try starting from the Wikipedia article on the lymphatic system.

Always on the trail of life-extension science. Previously, scientists had identified a gene responsible for part of the life-extension benefit of calorie restriction (at least in yeast), but not all of it, because knocking out that gene didn't entirely remove the effect.

Well, today I read a report that two more genes that mediate CR lifespan extension in yeast cells have been found, and that the three together appear to account for all of the longevity benefits of calorie restriction.

Okay, so it's in yeast, but the extent to which the CR effect is conserved across most of the biological kingdom is pretty remarkable.

Comet impact simulation from Sandia Labs. The results of an early supercomputer simulation of a 10-kilometer comet hitting the ocean at 60km/s. Approximately what happened to (probably) kill the dinosaurs 65 million years ago.

The 3-kilometer skyline of New York is shown in the images, for comparison. There are movie files that play out in real time. The comet enters the atmosphere, hits the ocean, and sends up a hypersonic 30-kilometer plume of vaporized comet and ocean water in about one second. The water (orange band in the movie) is about five kilometers deep, but just the shockwave of compressed water makes a visible crater in the solid ocean floor below, in less than a second.

Fortunately for us, impacts like this don't happen very often.

• New material is harder than diamond. A new material created by compressing fullerenes at ludicrous pressures is pure carbon, but is a bit denser and harder than diamond.
• The international ban on ozone-depleting chemicals appears to be working. Since the global ban on CFC's and ozone-depleting chemicals, the ozone layer has stabilized, stopping it's previous progressive shrinkage. I can't see from the popular press article if the paper established a causative connection or not. But, the signs are good. And if international cooperation helped save the ozone layer, that may be a good sign for eventual international efforts to reduce greenhouse emissions.

Carbon nanotubes and other fullerene molecules have long held the promise of revolutionizing many fields of science and technology. They're stronger than any known material, and depending on the variant can have all sorts of fun

The problem is, they're hard to make. When I graduated college, the longest nanotube made was less than a millimeter: too short to be spun into fibers. Now today, I read a report of a group that's making transparent ribbons and sheets of nanotubes up to seven meters long. They use a "forest" of parallel nanotubes, which was invented a few years ago, and then draw them out into a flat ribbon.

The individual tubes are still short enough that the completed tape is only as strong as kevlar or so, but that's still lightyears beyond the state of the art the last time I heard about this sort of work. Also, it's transparent and can conduct electricity depending on which sort of nanotubes they use in its construction. Here's a photo of a meter-long nanotube sheet.

One of the reasons photovoltaics (i.e., solar cells) are so expensive is that they require high-quality silicon crystals, the same sort used in microchips. Low-quality silicon is cheap and abundant, but doesn't work well in photovoltaics.

Or, didn't work well. In a new report, several scientists describe a technique that vastly improves the efficiency of solar cells using cheap low-grade silicon. Primarily, they cool the crystals more slowly than normal. This allows the impurities in the crystal to aggregate in clumps rather than disperse evenly throughout the crystal, thus getting them "out of the way" of flowing electrons.

If it works, it could be a path towards mass-marketing of solar cells that are, say, 85% as efficient as the best ones, but cost a third as much.

I also learned some interesting and exciting facts from the article, for example that the solar market is already growing by nearly 50% a year in this country. Or that by next year, solar energy will use more silicon than computers.

Perhaps we really are on our way to greener power generation.

Global warming is hard to pin down. Half a degree in the next century ... the biggest nasty effects probably still decades off ... hard to tie to human emissions (for those few scientists still sucking at the GOP teat, anyway).

Enter ocean acidification. It turns out the increased CO2 concentration in the atmosphere is causing the oceans to become more acidic. The pH of the oceans has lowered 0.1 in 200 years .... and may go another 0.5 by the end of the century. Very *clearly* tied to human CO2 emissions.

A half-point decrease in ocean pH would kill huge swaths of ocean biodiversity, screwing with coral and shell formation, among other things.