problems in biology,” he says. “By studying biological systems and the things that they do well, we can then try to translate those traits into our various engineering systems — like underwater vehicles.” In one sense, the approach is a design strategy, Dabiri explains; Engineers can look to natural, living organisms and how they move to improve mechanics and efficiency. Many of those studies center on a long, narrow room, stark and windowless, in the W. M. Keck Laboratories, a building that presides quietly over the Caltech campus from its precise center. Within that space is a 130-foot-long tank — the Keck 40-Meter Flume — that itself has a relatively long history on the Caltech campus, where it was built in 1967. Dabiri oversaw the renovation of the lengthy, tilting water channel in 2007, when it was equipped with new electronic controls and diagnostics. A device at its downstream end generates waves; The flume, however, does not resemble a beach nor a water-park ride — it’s an unglamorous amassment of steel, tracks and wires. Into the tank, Dabiri and his team submerse four-foot model submarines, after they’ve been “modified to interact with the water like a jellyfish or squid,” he says. Dabiri is specifically interested in the way jellyfish propel themselves through the ocean’s water, taking water into their voluminous bodies and expelling water out in a pumping motion. That
motion, Dabiri says, creates small whirlpools — swirling vortex rings — in the water that allow the jellies to glide more easily. And that ease of effort is commonly known as efficiency. “As (the subs) push themselves down the tank, we monitor how much energy they consume in the process,” Dabiri says. “We’re looking for modes of transportation that will reduce the energy requirements” it takes to move through the water. Dabiri’s not the only one looking for efficient modes of underwater travel; That’s also the domain of the Office of Naval Research, which last year selected Dabiri as one of its Young Investigators for his research in bio-inspired propulsion. While the jump from jellyfish to underwater vehicle may not require the greatest leap of imagination, biological propulsion may also shape the way wind energy is harnessed and even amplified, and it starts with a little schooling — of fish. Scientists have long been curious to explain how and why fish swim in regular groupings; Dabiri sees efficiency in the patterns the schools of fish create. Like jellies, the fish create swirling vortices that allow them to move en masse — with less energy — through water. By engineering wind turbines to spin on a vertical axis, rather than the standard horizontal axis, and by arranging them in a pattern similar to a throng of schooling fish, wind coming from any direction can be easily channeled. “It turns out that the arrangement of vortices that’s optimal
BEYOND JELLYFISH
BY JANETTE WILLIAMS
Not your mother’s milk: Venemous sea snails Predatory marine snails that hunt down fish and harpoon them with a paralyzing poison — how cool is that, Occidental College biochemistry major Erik King recalls thinking when he first heard about the school’s cone snail project. “And then, oh my god, they’re also venomous and you get to feed and milk them,” King says, laughing. “These aren’t your average garden snails.” But, he says, there’s a lot more to Conus catus than the cool factor. The small tropical cone snail, subject of a biomedical study led by Occidental Professor Joseph Schulz, may hold the key to new ways of treating chronic pain. Schulz — who just received a $200,000, two-year grant from the National Institutes of Health — says one class of neurotoxins from the snails’ venom has already led to the development of Prialt, a Federal Drug Administration-approved treatment for severe pain. “It blocks the calcium channel involved in conveying pain signals” to the brain, Schulz says. It’s “a primary alternative to morphine,” which can stop working as patients develop a tolerance. Scientists do not even have to change
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COURTESY JOSEPH SCHULZ Conus catus, with an extended probe.
the toxin sequence developed by the snails, Schulz says — “they evolved the best treatment.” The cone snail is “the poster child for tropical marine diversity,” Schulz says, and different species are found throughout the tropics, including one on the California coast — and the giant Conus geographicus, which can be fatal to humans. “People pick them up, thinking they’re pretty shells,” he says. “The snails will sting them and it paralyzes the diaphragm. (Victims) can’t breathe and suffocate.” And, he says, there’s no anti-venom for cone snails. “Conus catus is a small fish-hunting cone snail, and that’s OK with me — the smaller ones inject less venom and are not likely to kill my students,” Schulz jokes. But, he says “pound for pound” their venom delivers the same punch.
The Occidental cone snail project, started in 2001, is a long-term study, says King, who has spent two years — including two summers — working on it. “One nice thing in our lab: Many in this field kill the organisms they’re working with, (but) we keep them alive many, many years — up to eight or 10,” says King, one of four undergraduate researchers. “We milk them; we treat them very well.” How do you milk a venomous sea snail? “We take a micro-centrifuge tube and put latex on top, and a fish fin on top of that,” Schulz says. “We put a fish in the water to get the snail excited and its proboscis comes out — an extension of its digestive tract. Instead of injecting the fish, it shoots out the venom, exactly what it’s shooting into its prey. We can do this on a daily basis.” No breeding technique has yet been developed, and the snails are captured from the wild without damaging the ecosystem, Schulz says. They’re research subjects, not pets, but they do have identifying numbers — and a couple have nicknames, King says. “One of them, with spots, is called Mickey Mouse.” R