Virtual Phantoms

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Talk about visualizing!

A Reuters article describes work being done by the Advanced Interfaces Group at the University of Manchester, using virtual reality interfaces to treat phantom limb pain. Some people who have lost a limb experience extreme discomfort—the sensation that a missing hand remains tightly clenched, for example—and successful therapies seem to trick the brain into believing it has control over the “phantom limb.”

Enter virtual reality (glad it’s still good for something). According to Reuters, the process “uses a headset and sensors to transport patients into a virtual world where they see themselves with two limbs which they can control and move to do tasks and play games.” In four out of five of the patients they worked with, pain was ameliorated.

One of the best descriptions I’ve read of such disorders, BTW, is a book by the neuroscientist V.S. Ramachandran, which eloquently sheds light on all of brain function by an examination of various traumas that can occur. Highly recommended.

Subducted

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A brief post, since people are waiting for me to go to dinner. (Added a little to it after the fact…)

The image above comes from the website for Quark Park, a temporary park set up to highlight interactions between Princeton artists and scientists. The specific installation is called “Subduction & Orogeny,” illustrating geological processes at work. Interestingly, the work takes the form of a diagram, given added heft (so to speak) by samples of rock representative of the geological strata in question. Other works appear far more abstract.

An article in Science News describes some of the more mathematical installations, but there’s a wide variety of odds and ends to choose from on the website. Unfortunately, you have to shuttle back and forth between the “Photo Gallery” page and the “Team Bios” page (which links to descriptions of the projects) to figure out what’s going on.

Tom Wolfe noted that “without a theory to go with it, I can’t see a painting,” which is oddly true, for very different reasons, in this case as well. With this work, without the scientific theory, you can’t see the meaning. In fact, with a lot of visualization, one misses (or misinterprets) the meaning if you don’t get an explanation of the theory to go with it.

Quark Park is open through the end of November, so if you happen to live near Princeton, New Jersey, you might want to check it out.

Sea Urchins from the Inside-Out

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An image similar to the one above appears as part of Science Magazine’s interactive poster on sea urchins that appeared as part of this week’s issue. What we’re looking at is cell division. The image comes from the University of Washington Center for Cell Dynamics, the work of George von Dassow.

In my previous post, I asked questions about use of “enhanced color,” and the images of cells call to mind similar questions. I assume that what’s going on is simple color-coding of different cell structures (part of what gives me that idea is an image about a third of the way down the associated page on cytokinesis and a QuickTime showing the actin filaments and microtubules in cross section, side by side). The technique for observing the different cell structures remains a mystery, since I can find no clues on the website, but it seems like an interesting part of the story.

The gallery page at the Center for Cell Dynamics offers more still images and movies, as well as at least one spiffy little interactive. Given the warning at the top of the gallery page, I have the impression they don’t think of these movies as anything of interest to a broad audience, but I have to say, these are pretty compelling visuals. And I, as a layperson, would love to know more about what I’m looking at and where the images came from.

As far as the color choice, I might suggest something a little different. My slight color-blindness makes discerning the difference between red and green slightly tricky at points, so it’d be a lot easier if the two separate images were colored, say, blue and yellow or somesuch. A spiffy article entitled “Color Theory for the Color Blind” does a nice job introducing some of the issues or percention and contrast, although it talks mainly about web pages. Some answers might also lie in a book I just acquired that describes the physiology of vision and how it relates to art, but I have yet to get far enough into it to say.

By the bye, the Science poster is part of a special issue that focuses on the Sea Urchin Genome. Turns out the little critters have played an important role in the last century and a half, giving biologists clues to pronuclear fusion, cromosonal development, the role of mRNA, gene expression, and on and on. Sea urchins lie near an important branching point on the evolutionary tree, making its genomic sequence of great interest. Go figure!

Questions

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This may seem lazy, but… We ended our visualization conference today with a discussion of imaging philosophy. And the above image came up in discussion. It’s the (in)famous “Pillars of Creation” image of the Eagle Nebula, taken by the Hubble Space Telescope, of course, and it’s gotten about as much visibility as any astronomical image of the last few decades. So without much ado, maybe I could just pass along a few questions for those of you who consider yourself members of “the general public” (whatever that means, anyway).

Did you know that the Eagle Nebula doesn’t shine in those particular colors? In fact, it looks more like this pink-ish image from Rob Gendler, which is at least closer in color to what you would see with your eye up to a telescope. Does it bother you that the image represents something that you wouldn’t see through the eyepiece of a telescope? Do you think image specialists are lying to you by presenting images in this manner? (You can learn how the Hubble team makes thir color images by reading “Behind the Pictures” at their website.)

For that matter, how do you think we should describe images like the one above? They’ve often been called “false color.” Does that sound appropriate? What does the term suggest to you? Hubble describes such images as ”representative color.” How does that sound?

As you might guess, those of us in the biz have our own ideas, but I’m curious if anyone out there would like to share their opinion(s).

Thanks!

In Saturn’s Shadow

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It’s tempting to do a simple report from the Astro-Viz ”06 workshop, since we’re starting to have conversations that might be of interest, but David Malin distracted me by presenting the above image as part of his keynote address this morning.

The Photojournal description of “In Saturn’s Shadow” tells us that the image “was created by combining a total of 165 images taken by the Cassini wide-angle camera.” We can see light scattered through the rings, as well as light cast on the dark side of the planet by the rings themselves. Obviously, one gets a sense of the extended nature of the rings as well.

“Color in the view was created by digitally compositing ultraviolet, infrared and clear filter images and was then adjusted to resemble natural color.” A sentence that gives me pause. I appreciate the description, but I’d like a little more detail (even if I think I can piece together what’s going on anyway). And the annotated image doesn’t help.

The corresponding page from the CICLOPS site provides a little more detail, describing color variations in the E ring in the “color-exaggerated” image above. Maybe there could be a link to a page describing what “color-exaggerated” means? Basically, I think they’re just trying to acquire a longer baseline (in terms of wavelength, stretching from ultraviolet to visible to infrared), thereby enhancing color contrasts.

Spiffy image, that’s for sure. Very spiffy. And it speaks to one of the points Malin made this morning: that compelling images can simply make one look more closely and phenomena, which excites curiosity and promotes thinking about the cosmos.

Toddlers Learn from Pictures!

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I’m attending yet another conference, so my posts might get a little shorter and more sparse this week, but… It’s also a visualization conference, so perhaps I’ll be inspired!

A Reuters article today cites newly-published research showing that infants and toddlers learn from pictures! To quote, “Illustrations in picture books go beyond entertaining children and teach them how to navigate the world, according to a study published by the American Psychological Association on Sunday.”

Evidently, the way young’ns interact with images has not been well studied up to this point, so the research brings an added level of rigor to the discussion of using visuals for early-age instruction.

A tantalizing line in the article states that “The results varied according to the children’s ages and whether a photograph or drawing was used,…” Leaving me crying out for more. Varied how? Photos versus drawings? Which was better? How do kids interpret drawings versus photos in terms of depicting reality? So many questions! I couldn’t track down the article, however, so the questions remain unanswered for now.

The research was done in part by Judy DeLoache at the University of Virginia Child Study Center.

Imaging hA3G

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I am under the impression that the image above shows the first-ever “snapshot” of the structure of an enzyme that could help resist HIV and the onset of AIDS.

According to an article from Reuters, some small percentage of people possess hA3G in spades, and they can fight off the effects of HIV for longer than others. The question is how. Knowing what the enzyme looks like helps scientists understand the chemical processes better and could help “design a drug to mimic its effects and perhaps provide the first medicine to boost the ability to fight AIDS,” as the Reuters reportage puts it.

According to the associated research article, “high-molecular-mass (HMM) complex […] can be transformed in vitro into an active, low-molecular-mass (LMM) variant comparable to that of HIV-non-permissive CD4+ T-cells.” Which seems to be something good.

The point, as far as this blog is concerned, is that the general structure of this important compound has been unlocked—or at least the first steps have been taken to understanding more about its elusive nature. Moreover, the spatial depiction of the chemical structure is fundamental to unlocking its secrets. And that’s what visualization is all about.

Bloody Palpitations

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The above image comes from a press release from MIT (which can be read ina recent issue of MIT’s Tech Talk as well) that describes work being done on imaging living cells. The cells in question (as the colors chosen for the height scale so transparently suggest) are red blood cells, and the “quantitative phase imaging” technique allows for observations of the cells’ shapes down to a few nanometers.

The spiffy thing? High resolution in scale allows us to see fluctuations in the membranes as they allow ions into and out of the cell. Cells prone to swelling can burst, and swollen cells also palpitate less, so studying their motion numerically is a boon to understanding the physical processes at work. This could help us understand diseases such as malaria and sickle-cell anemia at the scale of the blood cells themselves.

(As far as I understand, quantitative phase imaging has been used in Transmission Electron Microscopy (TEM) for some time, so its application in light spectroscopy is a new thing. Especially since you can’t use TEM to observe living cells. Just FYI, this differs from the technique I’d described earlier on this blog for tagging individual stem cells in bone marrow.)

I quite like the image above. What’s the Hitchcock quote? “Blood is jolly, red.” You take one look and you get a general sense of what’s going on, and the scale to the right provides a little more info. Nice.

Numerous other pictures accompany the press release, including a series of false-color images that reveal both normal and abnormal cells. Sadly, the captions shed little light (spectroscopic or otherwise) on what the images actually depict. Particularly egregious is a rather incomprehensible figure—according to its caption, it “shows the correlation between cell shape and membrane dynamics,” but what exactly does that mean? Of all places, it seems that MIT would want to present imagery that could be read across a variety of technical disciplines, and this figure doesn’t cut it! Couldn’t we get more information than “Δu&sup2(q)” versus “q” (although they kindly include units)? I’ll tell you this much—a little research revealed that “discocyte,” “echinocyte,” and “spherocyte” refer to diffferent red blood cell morphologies (cf. a “scientific highlight” from Australia for more information).

My gripe here is just that captions, particularly in press releases, should give enough information for a well-informed non-specialist to get a handle on the information being presented. After all, science reporters are most likely generalists who will appreciate whatever cues you can provide.

(Thanks to Phile Schewe and his “Physics News Update.” Also, I ran across another informative web site in my searches. Lots of info about cell biology. And very difficult quizzes!)

Airport Images

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Having returned to New York from my trip, I figured I could offer two airport observations…

While waiting for my flight at the Lousiville International Airport, I had a good view of a pari of video panels set up by the Standiford Art Foundation as part of their “Video Art Project.” The three pieces each had their merits, but I found myself mildly intrigued by Thomas C. deLisle’s “Transition” (2005), which consisted entirely of Earth imagery from orbit.

I should first note that the screens were situated slightly off the beaten path (albeit on the way to restrooms, which is often a good thing), so no more than fifty or sixty people passed by in the hour or so I sat nearby. Of those, only five or six stopped to look, and highly subjectively, I’d say that the terrestrial imagery held their attention longer than the other pieces—one a somewhat abstract view of reflections on water, the other a continuous drive-by of suburbia. But people didn’t linger very long, usually only fifteen or twenty seconds and only once more than a minute.

The problem I had with the piece was the rapidity with which images cut from one to the next, leaving little time to absorb anything within the frame. Plus, the physical set-up consisted of two screens with separate content on both, making the transitions feel even faster-paced. I kept looking for some connection between sequential frames or paired images, but none struck me. Between the speed of cuts and the randomness of the images, the net effect was a bit like watching a screen saver with poor settings. But the Earth stuff seemed to have a slight allure for passers-by… Perhaps if it had offered more time to absorb the visuals?

On a related airport topic, I also took a look at Accenture’s interactive video wall at O’Hare International Airport. This has nothing to do with science, per se, but in fact, it would be nice if it did! When you step up to the screen, you’re given options for “Weather,” “News,” “Sports,” “Entertainment,” and “Tiger Woods.” Why not “Science”? Given the degree to which science and technology affects our lives, it seems like a no-brainer. Then we could implore Accenture for data on how often people select the “Science” option relative to others.

I’ve read some rather critical appraisals of the technology, but in fact, people spent a bit of time interacting with the thing (more than looked at the video art in Louisville, that’s for sure), and its interface felt completely transparent to basically everybody who stepped up to the screen. That strikes me as successful. I mean, the Windows-like grassy field and blue sky kinda creeps me out, but even I won’t hold that against ’em. Too much.

Roving Mars

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So I finally saw Roving Mars, the Imax® film about the MER mission—those wee rovers on Mars that have currently enjoyed more than 1,000 sols (i.e., Martian days, which clock in about three percent longer than terrestrial days) of exploration on the Red Planet.

First off, the film tells its story brilliantly. From the human scientists to the anthropomorphized rovers, the characters play roles that win over the audience and keep the narrative moving. Furthermore, the movie manages to balance the engineering and the science, which has proven tricky in other documentaries I’ve seen, particularly when they came out early in the mission.

But what I find intriguing about the film is something that my coworker Carter Emmart mentioned right after he saw it—the incredibly blurred line between real and computer-generated imagery. Actual rover images segue seamlessly into animated shots, and it sometimes takes a moment (for an expert, if I may refer to myself thusly) to distinguish between the two. I even got into a discussion with a planetary geologist afterward about whether one of the scenes was computer-generated or shot on Earth!

This is more than a testament to software tools and technological acumen. It also raises questions about how audiences perceive science content. If we don’t let people know the source of the imagery we present, do they end up thinking more or less of the end product? I’d be curious to know when (or if) they perceive the shift from reality to animation. One would hope that people would recognize that no film crew followed the rocket into space and no aerial cameras exist to execute the fly-overs of the rovers on Mars, but… And conversely, do people realize how much even the computer-generated media is informed by the science? Does it matter?

In surveys conducted for the Cosmic Collisions show production at my home institution, we found that people placed great value on knowing that visuals were rooted in scientific visualization of real computational data—and they put even higher stock in imagery that came from spacecraft observations. Thus, an actual image of the Sun had greater cachet than a computer simulation, which in turn meant more to people than an artist’s rendition.

So is it important to make sure people know what they’re looking at? You certainly don’t want to disrupt the flow of the story, but Roving Mars chose, as most pieces do, not to address the issues at all. That makes me a little uncomfortable.

At the end of the day (or the sol), the film weaves an exciting, even touching narrative, and the detailed, highly accurate imagery serves the subject well. I certainly think that the richness of the data—of realism—infuses every frame of the film with greater impact than “mere artistry” could accomplish. When you look at the real stuff, you get a subliminal sense of the complexity that I think most people find satisfying.