Caltech Professor Cited for Insights into Atmospheric Phenomena

PASADENA, Ca.- The chemical constituents of Earth's atmosphere are linked together in a complex way. A subtle alteration of one can make significant, often counterintuitive changes to another. For his work in unraveling some of the knotty complexity involved in such atmospheric processes, the California Institute of Technology's John H. Seinfeld has been awarded the Desert Research Institute's 2001 Nevada Medal.

Seinfeld is the Louis E. Nohl Professor and professor of chemical engineering at Caltech. The Desert Research Institute is the autonomous research division of the University of Nevada and Community College System, and is one of the world's largest multidisciplinary environmental research organizations. The Nevada Medal recognizes outstanding scientific and engineering achievements that have led to a better understanding of the global environment.

As a young investigator in the 1970s, Seinfeld developed the first mathematical models of air pollution. Use of these models is now stipulated in the Federal Clean Air Act, and they remain the basic tool employed by scientists around the world to simulate urban and regional air quality.

His career has spanned everything from the "micro" of urban air pollution to the "macro" of global climate change. Seinfeld was one of the first scientists to describe the chemical processes that produce ozone in urban areas. Ozone is the gas in the upper atmosphere that forms a protective layer against excess ultraviolet radiation, but is also a key ingredient of photochemical smog. He has also advanced our insight into such things as acid rain, the global influence of aerosols in climate and cloud formation, and the production and evolution of aerosols in the atmosphere.

"Great progress has been made in understanding the detailed physics and chemistry of the urban atmosphere, progress that has led to significant reductions in air pollution," says Seinfeld. "Now, predicting how atmospheric chemistry and aerosols will interact to govern future climate is among the most challenging problems in all of science.

"It is to this end that our research group is now working. The Nevada Medal, with a distinguished list of former recipients, is one of this nation's most prestigious awards. I am indebted to the Desert Research Institute for this high honor," he says.

Seinfeld is a member of the National Academy of Engineering, a fellow of the American Academy of Arts and Sciences, and the former chair of the Division of Engineering and Applied Science at Caltech. He is the recipient of numerous honors and awards, including the NASA Public Service Award and the American Chemical Society's Award for Creative Advances in Environmental Science and Technology. He has published more than 400 papers and four critically acclaimed books, including the basic worldwide textbook on atmospheric physics and chemistry. The minted, silver Nevada medallion and $10,000 prize were awarded to Seinfeld in ceremonies in Reno last month.

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Caltech Celebrates Pauling Centennial

PASADENA, Calif.- In honor of the 100th anniversary of the late Linus Pauling's birthday, the California Institute of Technology will host "Frontiers in Science," a day of presentations by world renowned scientists including three Nobel Laureates. The event will begin at 10 a.m. on Friday, March 2, in Beckman Auditorium. It is free and open to the public.

The conference is organized by the Division of Chemistry and Chemical Engineering, and the program is:

10 a.m.: Opening Remarks - Ahmed Zewail, Linus Pauling Chair Professor, Caltech (Nobel Prize for Chemistry, 1999) and David A. Tirrell, McCollum-Corcoran Chair Professor, Caltech.

Session I - Chair, David A. Tirrell 10:15 a.m. - by Elias James Corey, Sheldon Emery Chair Professor, Harvard University (Nobel Prize for Chemistry, 1990), "Topics in Enantioselective Synthesis."

11 a.m. - Richard Lerner, President, The Scripps Research Institute, "All Antibodies Catalyze the Oxidation of Water." 11:45 a.m. - Jack D. Dunitz, Professor of Chemical Crystallography, Swiss Federal Institute of Technology, "Looking Backwards, Glancing Sideways."

12:05 p.m. - Intermission

Session II - Chair, Ahmed H. Zewail 1:30 p.m. - Charles H. Townes, University Professor of Physics, University of California, Berkeley, (Nobel Prize for Physics, 1964), "The Laser." 2:15 p.m. - Thomas Steitz, Eugene Higgins Chair Professor, Yale University, "Insights into the RNA World from the structure of the Large Ribosomal Subunit and its Ligand Complexes."

3 p.m. - Alexander Rich, William Thompson Sedgwick Chair Professor, Massachusetts Institute of Technology, "Linus Pauling: Personal Reflections."

3:20 p.m. - Closing remarks 3:30 p.m. - Adjournment

Pauling came to Caltech as a graduate student and received his Ph.D. in chemistry in 1925. He joined the faculty in 1926 and remained until 1964. Until his passing in 1994 he was a Professor of Chemistry, Emeritus, at Caltech and director of the Linus Pauling Institute of Science and Medicine in Palo Alto. Pauling was awarded the Nobel Prize in Chemistry in 1954 and the Nobel Peace Prize in 1962.

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CONTACT: Jill Perry, Media Relations Director (626) 395-3226 jperry@caltech.edu

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Caltech, Agere Systems scientists developtechnique to shrink memory chips

Researchers at the California Institute of Technology and Agere Systems, formerly known as the Microelectronics Group of Lucent Technologies, have developed a technique that could result in a new generation of reliable nanoscale memory chips. This research could lead to smaller, less expensive cellular phones and digital cameras.

The research development, announced December 13 at the International Electron Devices Meeting, applies to a type of memory called "flash" memory, which continues to store information even when the devices are turned off. This information could include personal phone directories in a cellular phone or the pictures captured by a digital camera. In a typical cellular phone, there are 16 to 32 million bits of data stored on a silicon flash memory chip. Each bit of data is stored in a part of the flash memory chip called a "cell." As the size of silicon memory chips decreases, the chips are more and more difficult to make leakproof, resulting in the loss of stored date.

Using an aerosol technique developed at Caltech, the researchers formed memory cells by spraying silicon nanocrystals through a bath of high-temperature oxygen gas. The end result was memory cells comprised of silicon on the inside with a silicon dioxide outer shell. The silicon nanocrystals store the electrical charge, whereas the insulating silicon dioxide shell makes the nanocrystal memory cells more leakproof.

"As compared to conventional flash memories, these silicon nanocrystal memories offer higher performance, simpler fabrication processes, and greater promise for carrying memory miniaturization to its ultimate limit," said Harry Atwater, professor of applied physics and materials science at Caltech and project director.

To overcome the potential leakage problem, Atwater and Richard Flagan, McCollum Professor of Chemical Engineering, and their students at Caltech, and colleagues Jan de Blauwe and Martin Green at Agere Systems developed a method to break up each memory cell into 20,000 to 40,000 smaller cells. Therefore, even if several of the smaller cells spring a leak, the vast majority of the charge will not be lost and the bit of data stored in the whole memory cell will be retained.

The aerosol approach has several advantages over the conventional lithographic techniques used to make today's flash memory cells. Because it requires fewer steps, it is less expensive and takes less time to produce. In addition, the aerosol approach will allow researchers to continue making smaller and smaller devices.

So far, the researchers have created extremely robust flash memory cells. For instance, they have charged and dissipated a single cell one million cycles without significant degradation, whereas with traditional silicon chips, 10,000 cycles is considered satisfactory. While these research results are promising, it is premature to predict if or when the technology will be commercially implemented.

In addition to Atwater and Flagan, other members of the Caltech nanocrystal memory team are postdoctoral scholar Mark Brongersma, and graduate students Elizabeth Boer, Julie Casperson, and Michele Ostraat.

The research was supported by funding from the National Science Foundation and NASA.

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Caltech Professor Honored by the Pope

PASADENA—Ahmed Zewail, 1999 Nobel Laureate in Chemistry and Linus Pauling Professor of Chemical Physics and professor of physics at Caltech, was appointed as an academician to the Pontifical Academy of Sciences on November 13 at the Vatican.

Zewail met Pope John Paul II at St. Peter's Basilica and was presented with the insignia of the Pontifical Academy. There are only 80 academicians who are members of the Pontifical Academy, which dates back to 1603. He and president David Baltimore, who was appointed in 1978, are two members from Caltech.

The purpose of the Pontifical Academy of Sciences is to promote the progress of the mathematical, physical and natural sciences, and the study of related epistemological problems.

Candidates are selected based on their work and their moral personality, regardless of ethnicity or religion.

The Pope requires the Academy to "serve the Truth," as stated by Pope Pius XI in 1936. As a member, Zewail will be expected to inform the Pope of scientific developments and their technological applications.

In presenting the honor, the Pope spent more than two hours with new appointees, speaking Italian in his formal address during the ceremony and later speaking English to Zewail one on one.

Contact: Jill Perry (626) 395-3226 jperry@caltech.edu

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Caltech chemist John Baldeschwielernamed winner of 2000 National Medal of Science

John Baldeschwieler, J. Stanley Johnson Professor and professor of chemistry, emeritus, at the California Institute of Technology, has been named by President Clinton as one of this year's 12 recipients of the National Medal of Science. The announcement was made today (Nov. 13) at the White House.

Baldeschwieler, who has been on the Caltech faculty since 1973, was cited for his work on molecular assemblies for use in the delivery of pharmaceuticals, for his work on scientific instrumentation, and particularly for his development of ion cyclotron resonance spectroscopy.

"I am delighted with the recognition that the award brings to our work at Caltech, and to the extraordinarily talented group of students that I've had the privilege to work with over the past four decades," Baldeschwieler said after receiving notification of the award.

David Baltimore, Caltech's president and a 1999 recipient of the National Medal of Science, said the award is a fitting tribute to Baldeschwieler's pioneering work in a wide range of fields.

"The National Medal of Science is America's most prestigious science honor, and I think it's appropriate that the award goes to John for his many contributions to basic science, as well as for his public service."

Baldeschwieler joined the Caltech faculty after several years at Harvard and Stanford universities. He was a member of the President's Science Advisory Committee from 1969 to 1972, serving as vice chairman from 1970 to 1972. He served as deputy director of the Office of Science and Technology from 1971 to 1973.

Baldeschwieler pioneered the use of nuclear magnetic resonance and double resonance spectroscopy, nuclear Overhauser effects, and perturbed angular correlation spectroscopy in chemical systems. His recent work concentrates on the use of phospholipid vesicles in cancer diagnosis and therapy, the development of scanning tunneling and atomic force microscopy for the study of molecules on surfaces, and on novel techniques for producing combinatorial arrays of oligonucleotides.

A native of New Jersey, he earned his doctorate at Berkeley in 1959. He is a fellow of the National Academy of Sciences, the American Academy of Arts and Sciences, and the American Philosophical Society.

He was a founder of Vestar Inc., and served as chairman of the company's board of directors until it merged with NeXagen Inc. to form NeXstar Pharmaceuticals. He also served as director of NeXstar until it was acquired by Gilead Sciences, Inc. Baldeschwieler was also a founder and director of Combion, Inc.

He currently serves as a managing member of the Athenaeum Fund and is a director of Drug Royalty Corporation Inc., the Huntington Medical Research Institutes, Pasadena Entretec, and several privately held companies.

The National Medal of Science is presented annually by the president to scientific leaders who have changed or set new directions in research and science policy. Baldeschwieler and the other 11 recipients will receive their awards at the White House on December 1.

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Caltech glassblower plies an ancient trade

PASADENA—On a university campus with gravity-wave detectors, quantum teleportation devices, femtochemistry lasers, and Mach-20 wind tunnels, Rick Gerhart's glassblowing workshop almost seems by comparison like a step back into the Middle Ages.

Gerhart plies a trade that hasn't changed fundamentally in centuries. Just like the glassblowers of bygone days, Gerhart must begin with a quantity of glass, heat the glass until it glows red, spin the nascent object slowly to keep it from sagging, blow air by way of a mouth tube to add volume and shape, bend it if necessary, and cool it slowly to avoid cracking it.

Then, if all has gone well, Gerhart is ready to deliver the custom-made glass device to one of his many clients in Caltech's Division of Chemistry and Chemical Engineering or, occasionally, to other experimenters across campus.

"Glassblowing began with the ancient Egyptians," says Gerhart, an easygoing Caltech employee of seven years and a professional glassblower for more than 30. "Just like then, the goal is to keep the material from doing what it wants to do, which means you're always working with gravity.

"The way glassblowing probably got started was when some sand got too close to the fire and somebody noticed that you could gather up a glob and shape it," he says. "That's basically what artistic glassblowers do to this day."

Though the essentials really haven't changed much, scientific glassblowers like Gerhart have established a few shortcuts to make the work more uniform and efficient, and the glassware itself more durable. For one, Gerhart starts with Pyrex or quartz tubing of varying diameters and lengths, rather than a rounded mass of molten glass. This is not necessarily the best way to make an object of art, but it is an excellent means for constructing a receptacle that will likely be subjected to heat and high vacuums.

The way of the scientific glassblower, then, is to soften, shape, and fuse the glass tubing into a finished product. Pyrex is the choice for most routine experimental applications because it can take a lot of heat. But if the receptacle is to be cooled rapidly as well, the more expensive quartz tubing is preferable.

Another reason glassblowers use tubing is that it provides a head start on constructing a receptacle with rounded surfaces. Because chemists often use vacuums, they tend to avoid any sort of container with flat walls because a round receptacle is much better at resisting stress.

One might wonder why Gerhart's skills are necessary to a chemistry department when glass beakers and such can be ordered from a supply company. The answer is straightforward: because a cutting-edge chemistry department aims at doing one-of-a-kind experiments to uncover the subtleties of natural law, the researcher often requires a one-of-a-kind glass device to perform the experiment. Glass is the medium of choice because it reacts with very few chemicals, is relatively pliable and easy to work with, and is fairly cheap. Finally, glass provides a window to observe the ongoing experiment.

Gerhart has designed glassware for many of Caltech's most noteworthy chemists—including the 1999 Nobel laureate Ahmed Zewail. Another of his regular customers is John Bercaw, who is at the forefront in the design of catalysts for real-world applications. A typical glass high-vacuum manifold system for Bercaw can easily cost $20,000 to $30,000 and snake around half a laboratory.

"That's a good example of why my job exists," Gerhart says. "Once a (piece of work) is finished, there's nothing exactly like it in the world.

"For the more routine items you need—like beakers and flasks and test tubes—you can go through the catalogs from the supply houses and order them. I could make them, but there wouldn't be any point."

As for whether the work of the glassblower will always be needed, Bercaw has an interesting perspective. Though he often collaborates on computer simulations of experiments, Bercaw thinks chemists will never get away from regularly pouring a few chemicals.

"Experiments are always going to be required," he says. "So wherever there's experimental chemistry being done, there will always be a need for glassblowing.

"Glassblowing is not work that can be done by a computer—this is a real art," he says. "So you need someone talented and with a sense of aesthetics, and Rick is really good."

Nonetheless, Bercaw and Gerhart both say that chemical research has changed in such a way the last 20 years or so that the workload of a glassblower has inadvertently decreased. The reason is that chemists prefer to use smaller amounts of chemicals these days, which means that smaller glassware and experimental setups are required, which in turn means less human labor is required to produce the glassware.

"It takes a lot of time and manpower to make large and complicated glassware," says Gerhart. "So I think a lot of staffs have shrunk by attrition."

A native of Corning, New York, Gerhart grew up in a place where the glass industry has long been a significant economic force. Though he doesn't particularly consider glassblowing the family business, his father was a scientific glassmaker, and an uncle made glassware for the National Institutes of Health.

Although a child when his father died, Gerhart's early exposure to the glassblowing trade piqued his interest. At 20 he enrolled in a two-year program at Salem County Technical Institute in New Jersey—the only school in the United States for scientific glassblowing and one of the few in the world where one can study the art.

"Today, the best way to get into the business is probably to go to trade school," he says. "Or if you're really lucky, you might get to be an apprentice, but that's less likely these days now that glassblowing departments are getting smaller."

As for job satisfaction, Gerhart says he has no complaints. He enjoys the work and was rewarded by his peers in 1997 when they elected him president of the American Scientific Glassblowers Society.

"It's different—every day the workload changes, and every couple of years you're working with new people because a new set of graduate students and postdocs has come along. "Also, you get to work with the elite in research," he says. "So it's not a routine job—not a mundane job."

Contact: Robert Tindol (626) 395-3631

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Caltech researchers breed new genes to make natural products in bacteria

PASADENA—Using a new process of "sex in the test tube," a California Institute of Technology research group has been able to mate genes from different organisms and breed new genetic pathways in bacteria. These bacteria make an array of natural products that are naturally found in much more complex organisms.

The natural products, which are carotenoids similar to the pigment that gives carrots their color, are made by many different plants and microbes, but are totally foreign to the E. coli bacteria the researchers used. The new results, reported in the July issue of the journal Nature Biotechnology, show that the carotenoid-producing genes from different parent organisms can be shuffled together to create many-colored E. coli. Many of the carotenoids made in the bacteria are not even made by the organisms from which the parent genes came.

One of the reddish products, torulene, is not produced by any known bacteria, although it is found in certain red yeasts. "With molecular breeding, the experimenter can train the molecules and organisms to make new things that may not even be found in nature, but are valuable to us," says Frances Arnold, professor of chemical engineering and biochemistry at Caltech and coauthor of the new study.

Conceptually similar to dog breeding, the process generates progeny that are selected by researchers on the basis of attractive features. In this study, former Caltech researcher Claudia Schmidt-Dannert (now on the faculty at the University of Minnesota) and Caltech postdoctoral researcher Daisuke Umeno selected the new bacteria by their color.

This process of directed evolution, which Arnold has been instrumental in developing, is capable of creating new biological molecules and even new organisms with new or vastly improved characteristics. Unlike evolution in nature, where mutations are selected by "survival of the fittest," directed evolution, like breeding, allows scientists to dictate the characteristics of the molecules selected in each generation.

"We are now able to create natural products that usually have to come at great cost from esoteric sources simply by breeding ordinary genes in ordinary laboratory organisms," says Schmidt-Dannert.

The researchers believe that this method will be widely useful for making complex and expensive natural molecules such as antibiotics, dyes, and flavors. "Imagine being able to produce in simple bacteria many of the compounds that come from all over nature," says Arnold.

And, according to the authors, an even more irresistible target of directed evolution is finding bacteria that make biological molecules not yet found in nature.

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Honors for Caltech Faculty

PASADENA—Harry Gray, the California Institute of Technology's Beckman Professor of Chemistry and director of the Beckman Institute, has been named a Foreign Member of Great Britain's Royal Society, as well as a member of the American Philosophical Society.

Membership in the Royal Society is an honor that is bestowed each year on a small number of the world's outstanding scientists. One of the most prestigious learned societies, whose founding helped usher in the age of modern science, the Royal Society was established in 1661 under the patronage of King Charles II "for the purpose of improving natural knowledge." Isaac Newton was its first president.

In its citation, the society credited Gray with making "seminal contributions to virtually every area of modern inorganic chemistry."

A Caltech professor since 1965, Gray was named the Arnold O. Beckman Professor of Chemistry in 1981, served as chair of the Division of Chemistry and Chemical Engineering from 1978 to 1984, and became head of the Beckman Institute in 1986. He received the National Medal of Science in 1986.

Additionally, Gray has been elected a member of the American Philosophical Society. The society is the oldest learned society in the United States devoted to the advancement of scientific and scholarly inquiry.

The Philosophical Society has also elected Maarten Schmidt, Caltech's Francis L. Moseley Professor of Astronomy, Emeritus, as well as alumnus Leroy Hood, who earned a bachelor's degree in biology in 1960 and a PhD in biochemistry in 1968, and recently founded the Institute for Systems Biology, a private research center in Seattle; and alumna Sharon Rugel Long, who earned a bachelor's degree in 1973 in Caltech's Independent Studies Program, and is a professor in Stanford University's department of biological sciences and an investigator with the Howard Hughes Medical Institute.

Contact: Jill Perry (626) 395-3226 jperry@caltech.edu

Visit the Caltech Media Relations Web site at: http://www.caltech.edu/~media

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Harry Gray named cowinner of Harvey Prizeby Israel Institute of Technology

PASADENA—For the third time this spring, Harry Gray of the California Institute of Technology has been named recipient of a major scientific honor.

Gray has been named cowinner of the Harvey Prize, presented annually by the Israel Institute of Technology to a scholar or scientist who has worked toward promoting goodwill between Israel and the nations of the world. Gray, Caltech's Beckman Professor of Chemistry and director of the Beckman Institute, received the award and the $50,000 monetary prize in Haifa June 1.

Earlier this month, Gray was named a foreign member of Great Britain's Royal Society, as well as a member of the American Philosophical Society.

In conferring the prize on Gray, the Israel Institute of Technology cited him for his pioneering contributions to inorganic and bioinorganic chemistry, and particularly for "his studies of reaction mechanisms and the nature of the chemical bond in transition metal complexes, and of the long-range electron transfer in proteins."

The Harvey Prize was begun in 1972 by the late Leo M. Harvey of Los Angeles. The prize is awarded annually as a tribute to outstanding scholars and scientists throughout the world, and derives from a $1 million endowment.

Gray, a Caltech professor since 1965, was named the Arnold O. Beckman Professor of Chemistry in 1981, served as chair of the Division of Chemistry and Chemical Engineering from 1978 to 1984, and became head of the Beckman Institute in 1986. He received the National Medal of Science in 1986.

 

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Caltech Professor Frances Arnold Elected to Membershipin the National Academy of Engineering

PASADENA—Frances H. Arnold, professor of chemical engineering and biochemistry at the California Institute of Technology, was one of 78 engineers elected this year to membership in the National Academy of Engineering (NAE).

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.

Arnold 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. Even a single protein is enormously complex—"We don't know enough to design them from first principles," Arnold explains. "But evolution and breeding can yield beneficial changes rapidly."

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 will be many. "They range from making better laundry detergent enzymes to developing possible new treatments for diabetes and aging," Arnold foresees. "One favorite 'vision' is a chemicals industry that is based entirely on biological processes: clean, safe, and economical. To do this we will have to 'evolve' nature's fabulous enzymes into highly practical catalysts."

NAE membership 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. Election into the NAE is one the highest professional distinctions an engineer can receive.

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

Of the 2,027 members of the NAE, Arnold is one of 51 women. She also holds the distinction of being the only member who is the daughter of an existing member. Arnold's father, William H. Arnold, was made a member of the NAE in 1974 for his contributions to the systems engineering of light-water nuclear power plants and to the design of commercial pressurized water reactors for nuclear systems.

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