Three Join Other New Macarthur Fellows for 2004

Scientists Angela Belcher, Naomi Ehrich Leonard, and Julie Theriot have something in common. They are among the 23 people the John D. and Catherine T. MacArthur Foundation named in September as this year’s MacArthur fellows in recognition of their originality, creativity, and potential. Each will receive an unrestricted grant of $500 000 over the next five years.

Belcher, who specializes in nanotechnology, focuses on how to apply natural processes for making materials to the design of new, hybrid organic–inorganic magnetic and electronic nanoscale devices. Her research, says the foundation, “opens new avenues for controlling inorganic chemical reactions.” When she was a graduate student, for instance, she showed how natural proteins in abalone help create hard shells from calcium carbonate—the main ingredient of chalk. She subsequently modified peptides that bind with semiconductor alloys like gallium arsenide.

In her most recent work, Belcher, John Chipman Career Development Associate Professor of Materials Science at MIT, has produced self-assembling, submicroscopic metal films and wires. Rather than relying on high-temperature, metallic catalysis, or pressure—traditional tools of physical chemistry—she figured out a way to genetically modify viruses so that they interact with inorganic semiconductor solutions. Says the citation, “The ability to control this self-assembly process may one day lead to the next generation of microelectronics or other nanoscale machines.”

In work that combines control theory, fluid mechanics, robotics, oceanography, and other areas, Leonard designs feedback control laws for autonomous underwater vehicles so they can navigate on their own, despite the harsh and uncertain ocean environment. Her designs enable the sensor-equipped vehicles to maneuver in response to sensor measurements, the goal being to get to the right place at the right time to collect the richest data set. Such data are “essential for understanding the physical forces controlling ocean dynamics,” says the foundation.

A professor in Princeton University’s mechanical and aerospace engineering department, Leonard recently focused her work on the coordinated control of mobile groups or formations. Last year, she took part in the Autonomous Ocean Sampling Network project to test whether man-made underwater craft could be made to coordinate their motions to mimic the behaviors of biological groups, such as schools of fish, as they gathered data. Such autonomous underwater technology holds promise for a variety of applications involving searching, surveying, and mapping.

Theriot studies the way bacteria seize the customary role of actin—filaments made up of individual protein building blocks that help form a cell’s skeleton—to pave the way for their invasion of nearby cells. Each bacterium produces a protein that causes new actin filaments to grow and form bundles that resemble the tail of a comet. The comet tails propel the attached pathogen so that it rams into the cell’s membrane, then invades another cell, and continues to divide and spread to other cells.

An assistant professor of biochemistry and of microbiology and immunology at Stanford University, Theriot is able to analyze the biomechanics of this infectious process by measuring the forces generated by actin assembly and observing what conditions are needed to form the actin comet tail. “Through her research,” says the citation, “Theriot illuminates basic biophysical processes.” By studying how bacteria move, she and her group hope to deepen their understanding of numerous biological problems and help modern medicine fight the diseases resulting from pathogens.

Since 1981, when the fellowship program began, the MacArthur Foundation has named 682 fellows.