It's not really 'clostridi-poop'. This is a large, expensive protein for the bacterium to make. Hard to say what it's real purpose is, but many different and unrelated bacteria make potent toxins of this type.

The crystal structure that you display shows how the protein changes its shape when it encounters a cell. The long coils position themselves to penetrate the cell membrane and create a tunnel through which a second part of the toxin enters the cell. Once there, this portion inactivates key enzymes inside the cell.

The anaerobic nature of the different Clostridium species suggests that they are very ancient bacteria whose origins pre-date the appearance of free oxygen on the earth (that is, before the evolution of green plant cells). Now, they must survive in limited micro-envirionments where oxygen is depleted, such as badly-canned food, small regions of soil or mud, and the inside of the intestine. In some ways, they are truly creatures from 'another world'.

David Plotz, after reading a random Bible story, decided to read the whole thing (Well, the Jewish part, anyway). He started a blog of his impressions of the Bible called:

Blogging the Bible - What happens when an ignoramus reads the Good Book?

He tells a bit about it for NPR
http://www.npr.org/templates/story/story.php?storyId=6635153

Here's the link to his blog at Slate Magazine
http://www.slate.com/id/2141050/

I have seen a poster that is similar to this, featuring a heron and a frog with the caption, "Never Give Up"

Here is a link to one version:

http://lease-color-copiers.com/Never_Give_Up_Poster.html

I was really surprised when the metal culvert suddenly came floating up. It's a great study in road bed failure.

I kept waiting for a car to drive into the gap.

Re: Comment that radium-dial watch faces glow, therefore radioactivity makes things glow. The radium watch dials are a mixture of a rather small amount of radium and a mineral phosphor that absorbs the emission from the radium (dunno what type) and re-emits visible light.

The blue glow that comes from a nuclear reactor core is the real McCoy, but requires a really large amount of radioactivity to be visible. It is due to the effect of the ionizing radiation on the surrounding cooling water or surrounding air.

On another subject: Speed of sound.
The movie "Quigley Down Under" has Tom Sellick as an American sharpshooter in Australia. There is a scene in which he kills two (three?) men from a long distance away with his high-powered rifle. The single bullet went through the men, who were lined up together. There was only a very soft sound, and then the two men collapsed. Shortly afterward, the gun's report was heard. Very nice effect to indicate the distances involved.

The movie "2001: A Space Odyssey" used the soundlessness of space to good effect, dramatically contrasting the relatively noisy interior of the spacecraft with the stark silence of the outside.

So, whenever you want a room addition, you must "build ye more stately mansions!"

How come I'm the only one laughing?

About 15 or so years ago, I read about a similar scheme to help identify what kind of gun was used at a crime scene. Small particles of layered pigments would be added to gunpowder formulations. The layers would create a kind of barcode when viewed edge-on, and could distinguish a large number of different gunpowder sources.

The idea never got off the ground, though. It was vigorously opposed by the gun industry and by [groups seeking to preserve fourth-amendment rights].

This summer at church, one of the cars had a flat tire. I called my daughters over (aged 17 and 12), and asked them to change the tire for the owner, who was present. I had shown them how to do it the last time I had a flat tire at home, and they did a pretty good job of it.

My family was once given a 50-lb sack of wheat. My wife, who likes to do such things, decided to grind some of it into flour to make bread. My co-workers were already surprised that we made bread, and felt that it was a bit over the top to also grind our own flour.

Coarse and heavy. Oh well.

Since we were reading from the "Little House" books, my wife and daughters decided to plant some of the wheat in the back yard. When it was finally ripe, I cut it down with a large kitchen knife (sharpening knives is also an essential skill), and we dried it in a backyard shed.

Hmmm . . . thresh, winnow, grind, bake. A very labor-intensive loaf of bread. The people at work were sure we were crazy (they knew about ME already, but had reserved judgement on my wife).

Conclusion: It takes just about everything you've got to make a loaf of bread from seeds and dirt. The economies of scale and specialized knowledge of the farming and baking industries make it a lot easier. We're happy to have learned how to do it, but I think we won't do it again.

When I was growing up, my brother learned how to change the oil and do stuff with the car. I figured that I like to eat, so I learned to cook. I pay JiffyLube to do my oil changes, and they also dispose of used oil properly, unlike some neighbors. I hate doing car stuff so much, I'd gladly pay the oil service twice what they ask to have it done. On the other hand, I eat tasty meals more often than I need to change the oil.

Dunno . . . it reminds me of the famous "Expose Yourself to Art" poster from Portland, OR.

That's almost as good as the 'Passover Ham' that was shown here a while back.

Hairless hamster? It sounds like the other hamsters wouldn't let her play any hamster games.

I used to work for a small biotech company in Berkeley, where they had a room full of caged nude mice. This breed of mice is used in biological research, particularly cancer research. They are conveniently hairless, but also are "athymic": that is, they lack a thymus, which is an immune system organ. This prevents them from rejecting foreign tissue grafts, I think.

There was one of the scientists who was bald, wrinkled, and a bit portly. He looked a lot like the nude mice.

Nice music. Who knew traveling in China was so dangerous?

Is this some kind of allegory on the problematic journey of the olympic torch?

I've always liked the eerie similarity between the logos of the United Auto Workers (www.uaw.org) and the National Science Foundation (www.nsf.gov).

David Gu's comment about genetic influences may have some merit, but it actually runs counter to what is known about some Japanese attitudes, at least. While Americans sometimes talk about not having a "math mind", and put emphasis on inherent ability, the Japanese regard academic ability as a function of effort. Because of this, poor academic skills are seen as a sign of laziness, and are not excused as a lack of talent or genes.

The truth, as is often the case, probably falls somewhere between the two. My own anecdotal contribution relates to a conversation I had had with an Hispanic shuttle bus driver. She used to work at a food processing plant, but decided to get additional training in the operation of some of the machinery. With her new skills, she qualified for an increase in pay, which motivated her to take classes in computer science at the community college. She is now finishing her Bachelors degree at the local university. This was done while working full-time and raising two children, in whom she instilled an expectation of completing a college-level education.

I had been raised with all of the advantages of a middle-class background, but I don't think I could have done as well if I had been shouldering so many responsibilities at once. Her ability and expectation to do hard work, when applied to improving her education, let her come out from behind very quickly.

If a similar values/cultural change were to occur in the Hispanic population, I think people would soon be discussing the "superior genetics" of Latin America.

I think one important quote in the article was:

"High recalled a good Latino student she had a few years ago. He also was a gang member.

'He would wear baggy pants, and he would load up his pants with books," she said. "He looked around to make sure no one was seeing him so he could look like the baddest kid in the block.'"

It was important to the student not to be seen studying or making an effort on his education. In many ways, the thing we struggle to appear as, we become.