Caltech Professor Frances H. Arnold Elected to the National Academy of Sciences

PASADENA, Calif.-- Frances H. Arnold of the California Institute of Technology has been elected to the National Academy of Sciences, an honor considered to be one of the highest accolades in the scientific world. Arnold, the Dick and Barbara Dickinson Professor of Chemical Engineering and Biochemistry, is also a member of the National Academy of Engineering and the Institute of Medicine, making her one of only eight living individuals to have been elected to all three branches of the National Academies, and the only woman.

Arnold was elected for integrating fundamentals in molecular biology, genetics, and bioengineering to the benefit of life science and industry. Her research has revolutionized protein engineering and its applications to biotechnology, addressing central issues in protein design and the evolution of new biocatalysts.

She is one of the pioneers in the use of "directed evolution" to improve proteins and other biological molecules for commercial applications. Directed evolution applies the principles of breeding, but to molecules rather than animals or plants. Using these methods, Arnold has been able to generate proteins with a variety of useful features, like improved stability and the ability to function in nonnatural environments.

The practical applications of this research are very broad and include making enzymes that can effectively break down cellulose, the key structural component of plant cell walls, which would allow the efficient production of cellulosic biofuels.

"I am thrilled to have this recognition, and validation, of our efforts to use evolution to engineer biology," Arnold says. "At Caltech I have been able to work with great students and colleagues from disparate disciplines, who have helped me find new ways to look at problems. Caltech is both immensely stimulating and very supportive."

"Frances's work has changed the way we think about biological engineering, and her methods have been adopted by hundreds of laboratories around the world. It's a beautiful example of a new idea that proved to be almost immediately applicable to a broad range of fundamental and practical problems," says David A. Tirrell, the Ross McCollum-William H. Corcoran Professor and professor of chemistry and chemical engineering, and chair of the Division of Chemistry and Chemical Engineering at Caltech. "We're very proud of what Frances and her students have accomplished."

The National Academy of Sciences is a private organization of scientists and engineers dedicated to the furtherance of science and its use for the general welfare. It was established in 1863 by a congressional act of incorporation signed by Abraham Lincoln that calls on the academy to act as an official adviser to the federal government, upon request, in any matter of science or technology.

The election of Arnold brings the total Caltech membership to 75 faculty and three trustees.

Kathy Svitil
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Sixth Annual Caltech Science Writing Symposium

PASADENA, Calif.-California Institute of Technology President Jean-Lou Chameau and Pulitzer Prize-winning journalist Usha Lee McFarling will be the featured speakers at the sixth annual Caltech Science Writing Symposium. The topic of their conversation will be the importance and challenges of communicating science to the general public.

The symposium will take place on Friday, February 29, at 4 p.m., at Beckman Institute Auditorium on the Caltech campus. The event is free and open to the public.

As a civil and environmental engineer and president of one of the world's leading academic institutions, Chameau addresses diverse groups and often must communicate complex issues to audiences with varying ranges of scientific knowledge.

And as a former science journalist for the Los Angeles Times, McFarling, on a daily basis, had to clearly communicate technical concepts to the general public. Her recent series of articles, "Altered Oceans," which examines how ocean pollution threatens sea life and human health globally, won not only the Pulitzer Prize, but also awards from the American Association for the Advancement of Science, the American Geophysical Union, and the National Association of Science Writers. McFarling also wrote for the Knight Ridder Washington bureau and the Boston Globe.

Together, Chameau and McFarling will discuss the difficulties of conveying scientific information to nonspecialists and will share their insights and tips for communicating effectively.

The symposium is presented by the Words Matter program and Caltech's Division of Humanities and Social Sciences.

Deborah Williams-Hedges
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David Tirrell Elected to Membership in the National Academy of Engineering

PASADENA, Calif.- David A. Tirrell, Ross McCollum-William H. Corcoran Professor, professor of chemistry and chemical engineering, and chair of the Division of Chemistry and Chemical Engineering at the California Institute of Technology is one of 65 new members to be elected to the National Academy of Engineering (NAE).

Tirrell was noted for his "pioneering contributions to bioengineered materials and synthesis of novel artificial proteins," according to the NAE. Tirrell's research combines organic, biological, and materials chemistry to make new macromolecular systems with exquisite control of structure and function.

His research explores artificial proteins made by the expression of artificial genes in microbial cells. Tirrell uses biological cells to make proteins, just as nature does, but reprograms the cells to produce specific materials that are targeted toward important biomedical technologies. He is also investigating the creation of novel amino acids that are the building blocks for applications in biology, biotechnology, and medicine.

NAE membership is among the highest professional distinctions accorded to an engineer. It honors those who have made important contributions to engineering theory and practice, and those who have demonstrated unusual accomplishments in the pioneering of new and developing fields of technology.

Founded in 1964, the NAE is an independent, nonprofit institution that advises the federal government on issues of science and technology policy while conducting studies to articulate the societal implications of rapid technological change. The NAE also initiates programs designed to encourage international cooperation between engineering societies, to improve the public's technological awareness and understanding, and to enhance the dialogue between scientists, engineers, and policy makers.

Jacqueline Scahill
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Breaking Ground for Schlinger Laboratory

PASADENA, Calif.--Chemists and chemical engineers at the California Institute of Technology can soon start dreaming of experiments for their new labs, to be housed in a building dedicated to their work that will begin to take shape on February 13. The groundbreaking ceremony starts at 11 a.m.

The Warren and Katharine Schlinger Laboratory for Chemistry and Chemical Engineering is the first building specifically designed to house both disciplines under one roof at Caltech, providing laboratories and classroom and conference space.

The four-story building, which will occupy 60,000 square feet, was designed by Bohlin Cywinski Jackson, a Pennsylvania-based architectural firm that has won many awards and built numerous academic and lab structures. The Schlinger Lab, which will likely merit a silver rating under the Leadership in Energy and Environmental Design (LEED) Green Building Rating System for environmentally sustainable buildings, will be constructed at a cost of $45 million and should be finished in 18 months. It will be located near the western end of the San Pasqual walkway on campus.

First-floor labs will focus on atmospheric chemistry and materials. A conference room opening toward the chemical physics building was designed to encourage interactions among students and faculty. The third floor will feature synthetic chemistry with the Center for Catalysis and Chemical Synthesis (3CS), headed by Nobel Laureate Robert Grubbs, and funded by the Gordon and Betty Moore Foundation. The second floor and half of the underground floor will be designated for yet-to-be-appointed faculty.

The Schlinger Lab was named in recognition of a $20 million campaign donation from Warren and Katharine Schlinger, whose roots run deep at Caltech. Warren spent 12 years at the Institute, earning his BS in applied chemistry, then an MS and PhD in chemical engineering, followed by postdoctoral research and teaching. Katharine grew up in the Pasadena area and was a vocal soloist, and met her husband while working as a department secretary for chemical engineering. "The new laboratory will be central to the future of the division, and it's especially fitting that our friends Warren and Katie Schlinger have played the key role in bringing it to life," says David Tirrell, chair of the Division of Chemistry and Chemical Engineering at Caltech.

In response to their generosity, Caltech president Jean-Lou Chameau wrote that the Schlingers' gifts will "make a global impact on the progress of discovery in this field," adding that, "this historic initiative will change the landscape of our campus and amplify our ability to remain at the forefront of scientific research."

In addition to Schlinger and Moore Foundation contributions, gifts have come from an array of supporters, including the estate of former trustee Victor K. Atkins; trustee G. Patricia Beckman (daughter of Mabel and Arnold Beckman, PhD '28); Barbara J. Dickinson (widow of Richard Dickinson '52); The Ralph M. Parsons Foundation; the John Stauffer Charitable Trust; John W. Jones '41; Helen and Will Webster '49; Gregory P. Stone '74; and others. Funds raised to date total $37 million. 

Elisabeth Nadin

Energy-Efficient Refrigeration from Ultranarrow Silicon Wires

PASADENA, Calif.-- Supernarrow silicon wires, or silicon nanowires, are laying the foundation for a new type of cheap yet energy-efficient microscopic refrigeration, with no moving parts, report researchers from the California Institute of Technology in a study published today in the journal Nature.

The researchers found that making silicon into nanowires could create highly efficient thermoelectric materials. Thermoelectric materials create a voltage--a difference in electric potential--when there is a difference in temperature across the surface of the material. The thermoelectric effect has been known for more than 200 years, and the materials have had niche applications, such as power generation in satellites. However, the efficiency with which thermoelectric materials heat at one end and cool at the other in response to electric current has been too poor to be of general use. To improve performance, other researchers have experimented with increasingly complex compositions and arrangements of rare elements. Although they have found newer materials with improved efficiency, those materials are expensive and difficult to miniaturize.

The Caltech researchers, led by James Heath, the Elizabeth W. Gilloon Professor and professor of chemistry, took a completely different tack by using silicon, the most abundant element on earth. Using a method developed in Heath's labs, they constructed nanowires that were from 10 to 100 times narrower than the wires used in current computer microchips and found that the nanowires became extremely efficient at converting between thermal energy and electrical energy, exhibiting a 100-fold increase in performance. Near-term applications may involve recovering waste heat from microprocessor chips to make those chips more energy efficient. Longer-term applications include their use in efficient cooling units for refrigeration, or in thermal to electrical energy conversion for large-scale applications.

"At these tiny dimensions, nature is doing things that were previously not thought possible," says Heath, whose research group carried out the experiments described in the study. "Optimizing materials for cooling or heat recovery applications involves a tricky trade-off of several different parameters, including the electrical conductivity and the thermal conductivity." It is often the case that an improvement in one of these parameters will adversely affect the performance of the others, Heath says, but "we find that we can greatly drop the thermal conductivity in these nanowires without affecting the other parameters, and this leads to dramatic improvements in the thermoelectric efficiency."

An additional parameter that the researchers were surprised to see improved in the nanowires is the thermopower, which is the amount of voltage generated in a material for a given thermal gradient. The improvement likely arises from a phenomenon known as "phonon drag," which comes when the sound-carrying vibrations in the atomic lattice of the nanowires are not in thermal equilibrium with the current carrying electrons. "We find that for ultrathin nanowires the electrons drag certain sound waves along with them as they move down the nanowire. This extra heat from the sound is enhancing the thermoelectric efficiency," says Jamil Tahir-Kheli, a theoretician with Caltech's Materials and Process Simulation Center and a contributing author to the study.

Although silicon nanowires are still about a factor of two less efficient than the most efficient known thermoelectric materials, researchers are optimistic that further improvements in the materials will soon be made. "Our theoretical models indicate that a number of exciting avenues are available to significantly improve the efficiency," says William A Goddard, the Charles and Mary Ferkel Professor of Chemistry, Materials Science, and Applied Physics at Caltech, the director of the Materials and Process Simulation Center, and a contributing author to the study. "However, even at their current efficiencies, these nanowires already outperform many commercially available systems, and so could potentially find near-term applications. This is one more example of the surprising properties of in the world of nanomaterials, an area stimulated by the pioneering work of Richard Feynman, Tolman Professor of Theoretical Physics at Caltech, in 1959, just as I was arriving at Caltech," says Goddard.

Other authors on the study were Caltech chemistry graduate students Akram Boukai, Yuri Bunimovich, and Jen Kan Yu.

Kathy Svitil
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Caltech Chemist Peter Dervan Wins National Medal of Science

PASADENA, Calif.—Peter B. Dervan, the Bren Professor of Chemistry at the California Institute of Technology, has been named one of eight recipients of the 2006 National Medal of Science. The award was announced Monday, July 16, by the White House.

The National Medal of Science honors individuals for pioneering scientific research in a range of fields—including physical, biological, mathematical, social, behavioral, and engineering sciences—that enhances our understanding of the world and leads to innovations and technologies that give the United States its global economic edge. The National Science Foundation administers the award, which was established by Congress in 1959.

Dervan, a former chair of Caltech's division of chemistry and chemical engineering, has influenced the course of research in organic chemistry through his studies at the interface of chemistry and biology.

A native of Boston, Dervan earned his BS from Boston College in 1967, and his PhD from Yale University in 1972. He was a postdoctoral fellow for a year at Stanford before arriving at Caltech as an assistant professor in 1973.

Dervan has pioneered a field of bioorganic chemistry with studies directed toward understanding the chemical principles for the sequence-specific recognition of the genetic material, DNA. He and his coworkers have combined the art of synthesis, physical chemistry, and biology to create synthetic molecules with affinities and sequence specificities comparable to nature's proteins. This chemical approach to DNA recognition underpins the design of programmable cell-permeable small molecules for the regulation of gene expression.

Dervan is a member of the National Academy of Sciences, the Institute of Medicine, the American Academy of Arts & Sciences, the American Philosophical Society, a foreign member of the French Academy of Sciences and the Deutsche Akademie der Naturforscher Leopoldina. His awards include the Harrison Howe Award (1988), Arthur C. Cope Award (1993), Willard Gibbs Medal (1993), Nichols Medal (1994), Maison de la Chimie Foundation Prize (1996), Remsen Award (1998), Kirkwood Medal (1998), Alfred Bader Award (1999), Max Tishler Prize (1999), Linus Pauling Medal (1999), Richard C. Tolman Medal (1999), Tetrahedron Prize (2000), Harvey Prize (Israel) (2002), Ronald Breslow Award (2005), and the Wilbur Cross Medal (2005).

He has been a member of the Scientific Advisory Boards of Gilead Sciences since 1987, and the Robert A. Welch Foundation since 1988, and has served as a director of Beckman Coulter since 1998.

The National Medal of Science is presented annually by the president. Dervan and the other seven recipients will receive their awards at the White House on July 27.

Robert Tindol

Ralph M. Parsons Foundation Awards $1 Million Grant to Caltech for New Research Laboratory

PASADENA, Calif.—The Ralph M. Parsons Foundation has pledged $1 million to the California Institute of Technology toward construction of a new building for chemistry and chemical engineering positioned to be the centerpiece of the Division of Chemistry and Chemical Engineering's plan for the future.

"I am delighted to thank the foundation for their commitment," said Jean-Lou Chameau, president of Caltech. "This grant represents a key component in moving a project critical to Caltech's future forward."

The new facility will be especially important in the Division's plans to further integrate teaching and research initiatives in chemistry and chemical engineering with other areas of science and engineering. The building is being named the Warren and Katharine Schlinger Laboratory for Chemistry and Chemical Engineering in recognition of a lead commitment toward the $35 million project from the three-degree alumnus (BS'44, MS'46, PhD'49) and his wife.

With approximately 60,000 square feet divided among three levels above ground and one basement level, the building will house seven research laboratories, one classroom and three smaller conference rooms. The Schlinger Laboratory will face San Pasqual Walk between the Noyes Laboratory of Chemical Physics and the Beckman Laboratories of Behavioral Biology, and will complete a cluster of buildings with complementary research activities.

Once constructed, the Schlinger Laboratory will support several research groups involved in projects aimed at new and synthetically useful chemical transformations with novel catalysts, the synthesis of complex organic molecules important in biology and medicine, and custom-designed polymers and nanometer-scale structures. Current plans call for the third floor to be committed entirely to organic synthesis.

The facility will house a world-class center for catalysis and chemical synthesis to be led by Nobel Laureate Robert Grubbs, the Victor and Elizabeth Atkins Professor of Chemistry. Increased space will also allow the division to bring in additional faculty who will take research in new directions, including the synthesis of pharmaceuticals and advanced materials, and the creation of alternative energy technologies.

Other scientists to move into the Schlinger Laboratory will expand our understanding of the chemistry of the atmosphere and the nature of atmospheric changes and how these changes influence the biology of the planet-an essential step in predicting how the global climate will evolve in the next few decades.

Through the years, the Parsons Foundation has provided exceptional support for both research and education at Caltech. The foundation was established in 1961 by the late Ralph M. Parsons, founder of the international engineering and construction firm that bears his name. The foundation, since 1974 a separate, free-standing, charitable organization independent of the corporation, awards grants focusing on the areas of higher education, social-impact programs, health, and civic and cultural endeavors.


Robert Tindol

Researchers Announce New Discovery about Polymers; Could Lead to Better Plastics

PASADENA, Calif.—In the late 1960s, the memorable advice given to a certain graduate of movie fame was to go into plastics. Forty years later, Caltech chemical engineering professor Julia Kornfield would like to add the word "shish-kebabs."

Shish-kebabs are beautiful, tiny structures that can form when polymers crystallize during flow. When magnified a million times they resemble a skewer running through a stack of bell peppers. Inside plastics, they make car body panels stiff and carpet fibers strong.

Shish-kebabs are responsible for the product's nice glossy finish and the hardness, but they are not without their problems. They might help you to resist a scratch, but they might also cause a layer to peel off. And that's why people want to control them.

Now, Kornfield and Yoshinobu Nozue at Sumitomo have led a team that has uncovered certain properties of shish-kebabs that should lead to improved materials in the most widely used plastics. The researchers are reporting their results in the May 18 issue of the journal Science.

"Our discovery is pertinent to the relatively strong and stiff plastics," says Kornfield. "For example, it will allow manufacturers to make polymers for complex and beautifully shaped body panels with equal or better quality than currently available-and cheaper and faster."

Shish-kebabs are made of polymers known as polyolefins, which make up half of all plastics used-over 100 million tons per year. In addition to being used for car parts, polyolefins are also used to make pipes, wire, cable, carpets, fabrics, disposable syringes, and many other things.

Polyolefins are useful because manufacturers can custom-design their properties, Kornfield explains. By varying the degree of crystallinity and the way the crystals come together, polyolefins can be altered so that they are as hard as steel or as soft as a rubber band.

"The plastics industry can tailor-make molecular distributions, but we don't know how to manipulate them," Kornfield explains. "This discovery opens up a whole new neck of the woods that people didn't know they could explore, and they'll be able to create combinations of properties you couldn't get before."

Much as an inspiring leader can influence the action of thousands, the researchers discovered, some molecules (especially long ones) can marshal many others to create the shish, which then direct the formation of kebabs. This knowledge will allow for greater control of the creation process itself.

"In other words, you could make things by injection molding that you couldn't make before, and injection molding is a very cheap, fast process-you can pop a plastic bumper for an automobile out of its mold in a couple of minutes. So you bring down the cost of manufacturing and at the same time increase the throughput."

The lead author of the paper is Shuichi Kimata, a former postdoctoral researcher in Kornfield's Caltech lab. He played a central role linking Kornfield's group at Caltech with Yoshinobu Nozue's group at Sumitomo and collaborators at the University of Tokyo.

The title of the Science paper is "Molecular Basis of the Shish-Kebab Morphology in Polymer Crystallization."


Robert Tindol
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Moore Funds Center to Facilitate Chemical Discovery

PASADENA, Calif.-Facilities to automate the work of experimental chemistry may soon accelerate the process of chemical discovery at the California Institute of Technology, thanks to a grant of over $11 million from the Gordon and Betty Moore Foundation.

The grant will establish a Center for Catalysis and Chemical Synthesis (3CS), with facilities operated by the Division of Chemistry and Chemical Engineering. The center aims to speed the invention of new catalytic reactions, much as improved robotics accelerated the Human Genome Project.

Caltech chemists have proposed several major projects that could benefit from faster experimentation. According to Victor and Elizabeth Atkins Professor of Chemistry Robert Grubbs, founding director of the center and 2005 Nobel laureate in chemistry, projects will include the development and production of medicines, new reactions for making industrial products out of biomass, and the catalytic conversion of sunlight energy into stored chemical fuels.

"The increasing demands on chemistry resulting from new drug targets from the Human Genome Project and critical environmental requirements of chemical processes require us to develop more efficient techniques for chemical discovery," Grubbs says.

Bringing together scientists from a wide variety of disciplines, the center will create two new facilities, which will share resources to promote both the rapid discovery of chemical reactions and the production of focused molecular libraries.

Like test-kitchen chefs trying variations to perfect a recipe, robotics and instruments at the facility for catalyst and reaction invention will allow investigators to rapidly survey a wide array of reaction parameters. The conventional approach is labor intensive, taking researchers' time away from the conceptual or innovative aspects of their work, so researchers have often chosen familiar syntheses rather than taking the chances that could lead to new discoveries. By making experimentation easier, the center will facilitate the exploration of higher-risk strategies.

Many of the same techniques that are used for developing new reactions can also be used to synthesize molecular libraries. Researchers use libraries for an efficient and cost-effective "shotgun" approach, performing many simultaneous tests to see what works. Yet large existing libraries are not ideal for particular applications. The focused library facility will make it easier and faster to generate small libraries designed for specific targets, allowing researchers to optimize them efficiently for their selected applications.

The Gordon and Betty Moore Foundation was established in 2000 and seeks to develop outcome-based projects that will improve the quality of life for future generations. It has organized the majority of its grant making around large-scale initiatives and concentrates funding in three program areas: environmental conservation, science, and the San Francisco Bay Area.

The foundation's $300 million California Institute of Technology commitment, combined with an additional personal gift of $300 million from Gordon and Betty Moore, make Caltech the recipient of the largest donation ever made to an institution of higher learning. Gordon Moore is an alumnus (PhD '54) and trustee of the Institute.


Written by: John Avery

Contact: Pam Pollace (415) 561-7414

Jill Perry (626) 395-3226

Visit the Caltech Media Relations website at


Caltech and UCLA Researchers Create Memory Circuit the Size of a Human White Blood Cell

PASADENA, Calif.—Don't throw away your laptop yet, but there's a promising new high-tech invention being announced this week. Researchers have created a memory circuit the size of a white blood cell that has enough capacity to store the Declaration of Independence and have space left over. With 160 kilobits of capacity, it's the densest memory circuit ever fabricated.

Announcing the achievement in the January 25 issue of the journal Nature, the team led by chemistry professor James Heath of the California Institute of Technology says that the memory circuit is a milestone in manufacturing, even if it's not anywhere near readiness for the market.

"It's the sort of device that Intel would contemplate making in the year 2020," says Heath, who is the Gilloon Professor at Caltech. "But at the moment it furthers our goal of learning how to manufacture functional electronic circuitry at molecular dimensions."

The 2020 date assumes the validity of Moore's law, which states that the complexity of an integrated circuit will typically double every year. Current memory-cell size is .0408 square micrometers, so Moore's law assumes that the electronics industry will achieve a device density comparable to the Heath team's memory circuit in about 13 years.

However, the Caltech-UCLA team points out in their Nature article that manufacturers can see no clear way at present of extending this miniaturization beyond the year 2013. The new approach of the Heath team, therefore, will show the potential for making integrated circuits at smaller and smaller dimensions.

"Whether it's actually possible to get this new memory circuit into a laptop, I don't know," says Heath. "But we have time."

The 160,000 memory bits are arranged like a large tic-tac-toe board: 400 silicon wires crossed by 400 titanium wires, with a layer of molecular switches sandwiched between the crossing wires. Each wire crossing defines a bit, and a single bit is only 15 nanometers wide, or about one ten-thousandth the diameter of a human hair. By contrast, the most dense memory devices currently available are approximately 140 nanometers in width.

The molecular switches, called [2]rotaxanes, comprise two interlocking components—a molecular ring encircling a dumbbell-shaped molecule—that together are similar to a wedding band on a finger. When the molecular switch is electronically triggered, the ring slides between two locations on the dumbbell. Switching, then, arises from the different conductivities of the molecular switch with respect to the ring position.

Heath's group manufactured the memory circuit in a clean-room facility in their labs at Caltech, and the molecular switches were prepared by J. Fraser Stoddart, who holds UCLA's Fred Kavli Chair in Nanosystems Sciences, and his group.

The circuit has a bit density of 100 gigabit per square centimeter, which Heath's fellow lead author Jonathan Green says sets the record for integration density in a man-made object.

"We showed we can increase the density to nearly 1,000 gigabits per square centimeter, but, beyond that, there is almost no point, because you begin to run out of molecules," says Green, a Caltech graduate student in chemistry and applied physics.

The capability to manufacture electronic circuitry at such extreme dimensions opens up a host of new applications, ranging from extremely sensitive chemical and biological sensors, energy-efficient logic circuits, and a class of high-performance energy-conversion materials known as thermoelectrics.

The other lead author of the paper is Jang Wook Choi, a graduate student in chemical engineering at Caltech. The other authors are Akram Boukai, Yuri Bunimovich, Ezekiel Johnston-Halperin, Erica DeIonno, Yi Luo, Bonnie Sheriff, Ke Xu, and Young Shik Shin, all graduate students in Caltech's Division of Chemistry and Chemical Engineering, and Hsian-Rong Tseng and Stoddart, both of UCLA.

Robert Tindol
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