Tag Archives: tomography

Electronic Flu

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More electron microscopy! Except it’s only used as a background this time. A press release from the National Institutes of Health (NIH) describes work done by the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) to visualize the influenza virus. The image above, in all its 30,625 pixels of glory, is the only one that appears with the press release, which I find surprising for such a visual result.

The image itself does a pretty good job. The two-dimensional, black-and-white background image stands in relief to the brightly-colored, three dimensional model of the virus. But gosh, it’s a tiny picture! And for such a spiffy result.

Also, the press release states: “The research team used electron tomography (ET) to make its discovery. ET is a novel, three-dimensional imaging method based on the same principle as the well-known clinical imaging technique called computerized axial tomography, but it is performed in an electron microscope on a microminiaturized scale.” It’s probably worth saying that computerized axial tomography is more familiarly known as a CAT scan. Just sayin’…

Tomography Tick-Tock

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I like this image. It comes from an article in today’s Nature magazine about the Antikythera Mechanism, an ancient astronomical timekeeping device dredged up from the bottom of the sea more than a century ago. Having sat underwater for a few millennia, it experienced significant degradation, and it’s taken a while to put this Hellenic Humpty Dumpty back together again. The latest iteration on our understanding relied on x-ray tomography to gain a better, three-dimensional picture of the object’s inner workings.

And doesn’t the above image express that nicely? It obeys the common, airport-security conventions of what an x-ray should look like, as well as presenting the compelling, eroded face of the timekeeping device (as well as an inset of the same at home in a museum setting). One look and you get it: not the details, but the overall picture. And it’s aesthetically pleasing!

The research seems to be discussed on a website that remains persistently unavailable at the moment, but you can take a listen to this week’s Nature podcast. If you’re interested in more (albeit not so up-to-date) details, you can also read through Tony Phillips’s archive of “What’s New in Math to learn about the overall mechanism as well as details about its differential gears.

For those of you with a Nature subscription (or the willingness to shell out some bucks for the articles, you can read the full research letter as well as a bit of historical background that also appear in today’s issue. The story also receives coverage in a New York Times article (available for free for the next week only).

Before There Were Sponges

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I lifted the above image from an article in today’s issue of Science, which you probably can’t read unless you’re logged in from a subscribing institution. That’s okay: take a look at the Reuters article instead, although it doesn’t have any accompanying pictures.

Which is too bad, because however abstract, I think the above image (depicting results of x-ray tomography on the specimen) communicates its ideas fairly clearly.

The caption in the Science article reads as follows… “Aberrant embryos. (A) Reflected-light photomicrograph of a 3-cell embryo (specimen DOU-25). (B) Exterior isosurface model. (C) Volume rendered and extracted cell models, with the left cell rendered transparent to show the only subcellular structure (shaded green) in this embryo.” Admittedly, you might want to rewrite that before putting it in a press release: “(A) Here’s a photo. (B) We can reconstruct what’s inside. (C) We can even figure out its constituent parts—going so far as to see inside the fossilized cells to see their interior structure.” Something like that.

Of further interest is a punchline that appears in the scientific publication but not in the popular re-interpretation. The very last sentence reads, “the combined observations suggest that the Doushantuo embryos are probably stem-group metazoans.” Which, translated from biologiese, means that these cells are precursors to metazoans—i.e., further down the trunk of the family tree that led to us. Such humble beginnings…