View the LLNL home Back to the S&TR home Subscribe to Our magazine Send 
us your comments Browse through our index

 

 

 

 

 


Privacy &
Legal Notice



November 2002

The Laboratory
in the News

Commentary by
Leland W. Younker

This Model Can Take the Heat

The Best and the Brightest Come to Livermore

A View to a Kill

Biological Research Evolves at Livermore

Patents

Awards

 

 

the Best and the Brightest Come to Livermore

WOULD you apply to be a Lawrence fellow, knowing your chances were less than 1 in 100 of being accepted? For the applicants, the stakes are high. But the payoff is great for both the fellows and the Laboratory.
This postdoctoral program is formally known as the Lawrence Livermore Fellowship Program. Informally, it is called the Lawrence Fellowship in tribute to Ernest O. Lawrence, the cofounder of the Laboratory, who cultivated creativity and intellectual vitality in the scientists who worked with him. Lawrence Livermore National Laboratory strives to do the same.
The Laboratory has always been a place where postdoctoral fellows thrive. They can work on state-of-the-art equipment with leaders in their field, performing research in areas of high demand. While all postdoctoral fellows pursue independent research, most are hired by a particular program, usually to perform research for a specific project. Lawrence fellows have no programmatic responsibilities and are given the opportunity to select the group in which they want to work. The allure of freedom and an atmosphere that cultivates creativity, coupled with a competitive salary and Livermore’s extensive resources, make the Lawrence Fellowship Program a prestigious opportunity. In exchange, it brings to Livermore some of the most sought-after Ph.D.s in the world.
The fellows produce remarkably creative research during their tenure. Many stay on as full-time career employees, continuing their work. Some leave Livermore to take positions at other institutions. But, as one fellow says, “The ones who leave are ambassadors for Livermore for the rest of their careers.”

Andrew Williamson

Andrew Williamson

Kenneth Kim

Kenneth Kim


Solution to a Challenge
The Lawrence Fellowship Program was the brainchild of Jeff Wadsworth, former deputy director for Science and Technology. He initiated the program in 1997 in an effort to reverse the effects of the “dot-com” boom, which was leading many young scientists to choose the remuneration offered by private industry over employment with Department of Energy laboratories.
To help persuade the best and the brightest to come to Livermore, the Lawrence Fellowship offers an attractive salary and considerable research freedom. It was modeled after the J. Robert Oppenheimer Postdoctoral Fellowship Program at Los Alamos National Laboratory. In both programs, non-U.S. citizens may apply. Lawrence fellows are hired by the Director’s Office, in cooperation with Livermore’s University Relations Program.
The new program was first announced in the fall of 1997. Although some Lawrence fellows learn about
the program through contacts with Laboratory employees, most applicants find out about it through advertisements in journals such as Science and Nature or on the Web at either fellowship.llnl.gov/ or www.llnl.gov/postdoc/.
“We are interested in finding people who weren’t necessarily thinking about coming to Livermore or who didn’t know about Livermore initially,” says Harry Radousky, chair of the Lawrence Fellowship Program committee.
The fellows are chosen for 3-year appointments by a selection committee consisting of a representative from each of the Laboratory’s scientific directorates. The criteria for acceptance are rigorous. Out of 1,849 applicants in the first 4 years of the program, only 15 have been accepted. More recently, 282 applications were received for the program’s fifth year, and 2 applicants have been invited to participate.
Each application is read by the selection committee, which looks primarily for leadership of stellar research projects. Applicants must have received their Ph.D. within the last 5 years. The applicant pool is eventually reduced to 6 individuals who undergo a 2-day interview. On the first day, the fellowship finalist gives a seminar on his or her area of interest; has lunch with the committee, which serves as a question-and-answer session; and then meets with current fellows in the afternoon. On the second day, applicants have the opportunity to talk to Laboratory scientists with whom they might be interested in working.
The goal of this process is to find people who will succeed at the Laboratory. The likelihood of success is measured in several ways: by matching an applicant’s field of interest with those of the Laboratory, examining the applicant’s academic record and publications, and analyzing the research projects the applicant has initiated and the level of innovation those projects represent.
“We’re not looking for management skills but at scientific leadership,” says Radousky. “The object of the fellowships is to encourage intellectual vitality at the Lab and to recruit the best people in the world,” he continues. “What we’ve discovered is that the application process is an excellent way to attract people to all kinds of positions. Many applicants who don’t get into the Lawrence Fellowship Program are awarded postdoctoral fellowships to work in Laboratory programs or are hired as full-time employees.”
Of the 15 individuals who have received Lawrence Fellowships thus far, 3 are now career employees, 2 left to become professors at the Massachusetts Institute of Technology (MIT), 1 went to the National Institute for Standards and Technology, another returned to his native Belgium, and the remaining 8 are still Lawrence fellows.


The Results of Freedom
Freedom to work on projects and with mentors of their choice is what most current Lawrence fellows say attracted them to the program. This freedom, coupled with the Laboratory’s interdisciplinary atmosphere, also permits many fellows to move outside their initial area of specialization and investigate other scientific fields.
Wei Cai, for instance, a current Lawrence fellow from China, earned his Ph.D. from MIT. Midway through his graduate work, mentor Vasily Bulatov left MIT for the Laboratory. Bulatov encouraged Cai to apply for the program. Cai was a successful fellowship applicant and has worked not only with Bulatov but also with Malvin Kalos, the father of quantum Monte Carlo simulations. With Kalos, Cai has been investigating how to use Monte Carlo simulation codes more efficiently for modeling the microstructures of materials. Cai has amended some of Kalos’s techniques and applied them to small-scale problems with great success. Now, together with Kalos, Bulatov, and other Livermore researchers, Cai is working on a project funded by the Laboratory Directed Research and Development (LDRD) program to apply these techniques to larger, more complex systems. Cai has also been working on a new massively parallel computer code for modeling dislocation dynamics. “What happened here has a lot to do with the academic freedom the fellowship provides,” Cai attests.

Wei Cai

Wei Cai

 


This freedom also allowed Cai to work on a particularly exciting project far removed from his usual line of research. At the suggestion of Giulia Galli, leader of the Quantum Molecular Dynamics Simulations Group, Cai tried to solve a problem that Galli’s group was facing: adding a means of modeling a magnetic field to the electronic structure simulation codes regularly used to model condensed matter systems. Cai devised a code that successfully modeled in two dimensions the behavior of small systems, such as isolated hydrogen atoms and molecules, under an arbitrary magnetic field. The next step will be to apply this method with the more powerful electronic structure codes used for large-scale calculations, such as the modeling of magnetic field effects on the dynamics of fluid hydrogen.
Cai notes that the freedom allowed in the Lawrence Fellowship Program can be almost disconcerting at times. “You need discipline and must be able to make decisions at critical times about what you want to study.”

Quantum Monte Carlo simulations of a less reactive and more reactive silicon quantum dot.
Lawrence fellows Jeffrey Grossman and Andrew Williamson are using quantum Monte Carlo simulations to research the characteristics of nanostructures such as these silicon quantum dots. (a) A 71-atom silicon quantum dot. Hydrogen atoms (white) bonded to the surface make the material less reactive. (b) When a more reactive oxygen atom replaces two hydrogen atoms, the electron charge cloud (purple) is drawn toward the oxygen atom, dramatically changing the optical properties (wavelength) of the silicon quantum dot.

Working at the Nanoscale
Two computational physicists became a team as Lawrence fellows. Jeffrey Grossman, a Ph.D. from the University of Illinois at Champaign-Urbana, and Andrew Williamson, a Ph.D. from the University of Cambridge in England, had known each other for years and both were interested in working with Giulia Galli. Almost immediately after arriving at Livermore as fellows, they applied for LDRD funding to use quantum Monte Carlo simulations to learn more about the characteristics of nanostructures, atomic-scale dots 1,000 times smaller than the width of a human hair. (See S&TR, April 2002, Quantum Simulations Tell the Atomic-Level Story.)
“Scientific interest in nanotechnology centers around one very simple concept,” says Grossman. “When you make something really small, its characteristics change. At the nanoscale—just a few hundred atoms—a material’s properties start changing and become really interesting. Those differences and the ability to control the size of the structures mean that all kinds of new devices could be made—new ways to deliver drugs, storage systems for hydrogen fuel, detectors that can recognize microscopic amounts of anthrax in the air.”
Livermore’s supercomputers were a major draw for this duo because quantum Monte Carlo simulations are computationally intensive. With Livermore’s computers, they can do work that they couldn’t do at most places.
Another selling point was that Galli’s group was beginning a new project on nanoscience when Grossman and Williamson joined the Laboratory. “Part of what makes the Lawrence Fellowship Program so attractive,” says Williamson, “is the opportunity to create something new and shape the direction that research takes, rather than trying to come in and fit into a slot that was shaped by someone else.”

Jeffrey Grossman

Jeffrey Grossman

Julio Camarero

Julio Camarero


Experimental biologist Julio Camarero, who is also working at the nanoscale, saw the Lawrence program advertised in Science and Nature while a postdoctoral fellow at Rockefeller University in New York City. Camarero received his Ph.D. from the University of Barcelona.
At Livermore, he started out in the Biology and Biotechnology Research Program (BBRP) but moved to the Chemistry and Materials Science Directorate, where he continues to perform biological experiments. He is a member of a team that aims to use dip-pen nanolithography to create and probe ordered arrays of proteins and colloids. One of the many uses for dip-pen nanolithography is to create tiny sensors that will detect biological warfare agents.
“The Lab is interested in applying science and technology to create tools for national security,” notes Camarero. “I think that the technology we have developed is very powerful and has many applications, not the least of which is protecting us from biological terrorism.”
In dip-pen nanolithography, the tip of an atomic force microscope is dipped into either an organic or inorganic substance (the “ink”) and then is used to “write” on the surface of an inorganic substrate. (See S&TR, December 2001, Small Science Gets to the Heart of Matter.) As the tip moves across the surface, it creates a precise, orderly pattern, or template, of material that is in chemical contrast to the substrate surface.
The goal of Camarero’s research is to form specific chemical patterns less than 10 nanometers wide on silicon dioxide and gold surfaces. The chemicals in this template will react with proteins, thus making the template a sort of “molecular Velcro” to which the proteins bind in ordered arrays. Use of these templates allows for total control over the orientation of the proteins.

Schematic of dip-pen nanolithography.
Lawrence fellows Julio Camarero and Aleksandr Noy—now a full-time Laboratory employee—are pursuing research using dip-pen nanolithography. This technology uses the tip of an atomic force microscope (AFM) dipped in molecules to “write” on an inorganic substrate. The molecules react with the substrate to create a pattern of nanostructures attached to the substrate. These nanostructures have a variety of scientific uses.

Small, Complex Systems
Kenneth Kim was at the University of Cambridge as a Wellcome Trust fellow in the Applied Mathematics and Theoretical Physics Department when he learned about the Lawrence Fellowship Program from colleagues at the University of California at Berkeley and from Livermore’s Web site. Kim works in BBRP’s Computational and Systems Biology Division, led by Michael Colvin. “Traditionally, biology has been a qualitative discipline,” Kim says. “But mathematics can play an important role in the biological sciences by providing a precise and powerful language to clarify underlying mechanisms and reveal hidden connections between seemingly disparate systems. Mathematical modeling may allow biology to become a predictive science alongside physics and chemistry.”

Aleksandr Noy

Aleksandr Noy

Olgica Bakajin

Olga Bakajin


Kim is applying the mathematical methods of statistical mechanics to the study of the astonishingly complex interactions and collective behavior of biological systems. He has studied the collective behavior of interacting bodies (inclusions) in an elastic medium (a cell membrane). The mathematical model that describes this behavior can be used to investigate the mechanism that causes protein inclusions in cellular membranes to distribute themselves into large, stable aggregates as a function of their global shape. This research illustrates the rich interplay between geometry and statistical mechanics that underlies biological and other complex systems.
Kim is also developing a mathematical model for gene regulatory networks. In a gene network, the protein encoded by a gene can regulate the expression of other genes, which in turn control other genes. A protein can also regulate its own level of production through feedback processes.
“This network of interacting genes is another concrete example of collective behavior exhibiting an amazing degree of complexity at many spatial and temporal scales,” says Kim.
Olgica Bakajin of Yugoslavia is yet another fellow working at the nanoscale. Bakajin had completed her Ph.D. at Princeton University and was on her way to the National Institutes of Health (NIH) when Livermore called to inform her that she was a successful Lawrence fellow applicant. Since arriving at Livermore, she has worked on several projects related to the development of novel microstructures and nanostructures. She is designing and fabricating a fast microfluidic mixer for the study of proteins. Just 10 micrometers wide—a human hair is 80 micrometers wide—the mixer can cause proteins to fold and unfold when solution conditions in the mixer are changed quickly and precisely. Bakajin will be using the mixer to examine the kinetics of fast protein folding reactions (an LDRD-funded project) and to investigate the kinetics of the folding of single-protein molecules (a collaboration with NIH scientists).
Working with former Lawrence fellow Aleksandr Noy, Bakajin is using carbon nanotubes in microfabricated devices to separate biological molecules. In the future, these microdevices could be used as detectors of chemical and biological warfare agents. “The interdisciplinary atmosphere at the Lab has provided me with lots of research opportunities,” says Bakajin. “Right now, I have more ideas for interesting projects than I have time to pursue them.”

Magnified view of a microfluidic mixer designed and fabricated by Olgica Bakajin.
Olgica Bakajin is designing and fabricating this fast microfluidic mixer used for researching the kinetics of protein folding.

Here to Stay
Three former fellows are now full-time Laboratory employees, having exchanged some of the freedom of the Lawrence Fellowship for a staff position.
Theoretical biologist Shea Gardner, who studied population biology at the University of California at Davis, worked initially on several computational biology projects, one of which was a mathematical model to tailor chemotherapy treatments for individual cancer patients. Treatment strategies are based on the kinetics of the patient’s particular tumor cells. Gardner has filed a provisional patent for this modeling approach and has been contacted about commercially developing the software.
Gardner also worked on biostatistics for the analysis of gene microarrays. A microarray is a glass microscope slide covered with “spots,” each occupied by a different gene. (See S&TR, March 2002, Tracking Down Virulence in Plague.) The entire slide is exposed to a stimulus such as a chemical or a change of temperature, and scientists note how each gene responds to the stimulus. “With microarrays, you can see the expression of over 12,000 genes at once, in a single run,” Gardner notes. “Previously, you could look at just one gene at a time.”

Robert Heeter

Robert Heeter

 

Gardner is now participating in bioinformatics work for the National Nuclear Security Administration’s Chemical and Biological National Security Program, computationally identifying DNA signatures that could be used to detect biological pathogens. She hopes to continue with this research. “Mathematical modeling, biostatistics, and bioinformatics are really different,” she says. “Where else would I have had the opportunity to work on all three?”
Aleksandr Noy, a physical chemist from Harvard University, came to Livermore in 1998 to work on high-resolution microscopy. To that end, he developed a new microscope system that combines the topographic capabilities of the atomic force microscope with the spectroscopy capabilities of a confocal microscope. (See S&TR, December 2001, Small Science Gets to the Heart of Matter.)
“My interests morphed from just looking at tiny things to fabricating them and using them for nanoscience applications,” he says. “Shifting focus like that would not have been possible if I had not been a Lawrence fellow.” Noy has worked on several nanoscience projects, including some that use carbon nanotubes in unique ways. Much of his research requires his new microscope to make the results visible.
He now leads a group that is fabricating electroluminescent nanostructures by dip-pen nanolithography. The researchers “write” with a conjugated polymer that emits light when a voltage is applied. Nanowires made of conjugated polymer poly [2-methoxy, 5-ethyl [2´ hexy(oxy)] para-prenylene vinylene], or MEH-PPV, may some day serve as light-emitting nanodiodes. MEH-PPV nanowires are also highly sensitive to light and can serve as tiny optoelectric switches, which today are typically 1,000 times larger than tomorrow’s MEH-PPV nanowires will be.
Plasma physicist Robert Heeter heard about the Lawrence Fellowship Program from Paul Springer, a group leader in Livermore’s Physics and Advanced Technologies Directorate, who performs laboratory astrophysics experiments. Heeter has been working with Springer since coming to Livermore in 1999.
While at Princeton University earning his Ph.D., Heeter worked in England at the Joint European Torus, a magnetic fusion energy facility. But because of funding cuts, magnetic fusion research had fewer opportunities when Heeter was about to graduate. He was also interested in astrophysics, so he decided to apply for a Lawrence Fellowship at Livermore, which had active programs in both astrophysics and fusion energy.
Heeter became a Lawrence fellow and almost immediately got involved in photoionization experiments on Sandia National Laboratories’ Z Accelerator in Albuquerque, New Mexico. Today, he continues his photoionization research. “I’ve also been doing other experiments in high-energy-density plasma physics,” he adds. “I’ve stayed in the same group and in the same field that I was in as a fellow. High-energy-density physics experiments have numerous applications: in stockpile stewardship, in inertial fusion, and in astrophysics. And there’s a lot of fundamental science to explore that hasn’t been done before.”

Model of the DNA signatures of viral pathogens One of the research interests Shea Gardner pursued as a Lawrence fellow, which she continues today as a Laboratory employee, is modeling the DNA signatures of viral pathogens. These simulations contribute to technologies for detecting agents of biowarfare.

Laboratory Ambassadors
Not all Lawrence fellows stay on as full-time Laboratory employees. The most recent one to depart was metallurgist Christopher Schuh, who left in the summer of 2002 to become a professor at MIT. After completing his Ph.D. at Northwestern University, he came to Livermore to work on grain boundary engineering, in which conventional metallurgical processing is tailored to produce better metals. Grain boundaries—where crystals with different orientations come together—are the weak link in any material. Schuh examined ways to manipulate the orientation of crystals at grain boundaries to create metals with desirable properties such as less cracking, corrosion, and cavitation.
Schuh’s research also took him beyond grain boundaries to the individual atoms in the crystals. “If you disturb the atoms in metals so much that the crystal structure no longer looks anything like that of traditional metals, the metals will have very different properties,” says Schuh. “We’re trying to understand how these changes affect the physics of the metal.”
Schuh notes that postdoctoral fellows typically join a program with the understanding that they have been hired to work with someone on a certain project. “For Lawrence fellows,” he says, “there’s no such obligation. That gives you complete freedom and a lot of latitude.”
Nicolas Hadjiconstantinou received his Ph.D. from MIT and immediately joined Livermore as a Lawrence fellow, deferring a teaching appointment at MIT for a year. While at Livermore, he helped to develop a code that extended the use of direct Monte Carlo calculation from the simulation of dilute gases to the simulation of dense fluids. With this code, Livermore researchers can simulate for the first time the phase change characteristics of a van der Waals fluid.
Joel Ullom, who completed his Ph.D. at Harvard, focused on the development of cryogenic detectors, which are small electrical circuits that produce a current or voltage pulse when hit by a photon or particle. The detector must be cooled to temperatures between 0.1 and 1 kelvin, so that the energy of a single photon will produce measurable heating. Ullom used cryogenic detectors to weigh the protein fragments dislodged from bacterial spores by a pulse of laser light. He also developed refrigeration technology to produce the ultralow temperatures needed for cryogenic detectors. Ullom became a Laboratory career employee before leaving for a position at the National Institute of Standards and Technology.
Luc Machiels, a native of Belgium, received his Ph.D. from the Swiss Federal Institute of Technology. After a postdoctoral position at MIT, he came to the Center for Applied Scientific Computing, where he solved problems in continuum mechanics. With colleagues at MIT, he developed a new finite-element error control strategy for the version of the Navier–Stokes equation that describes the motion of an incompressible fluid. The technique, which is both accurate and efficient, calculates lower and upper limits for the output of a system, such as the temperature bounds at the surface of an electronic device. Before leaving Livermore, he also developed new techniques for the solution and modeling of partial differential equations.

A Resounding Success
Radousky has only good things to say about the Lawrence Fellowship Program. “We’ve learned that we can attract really top people to the Laboratory,” he says. “This program has attracted the best young scientists to the Lab and promoted university collaborations. It is also an excellent way to do general recruiting.”
When the program first started, more fellows were engaged in traditional physics research, while today more are studying biology and nanoscience. This shift is consistent with changes throughout the scientific community. Biological research leaped to the foreground with the success of the Human Genome Project. Many experts predict that the 21st century will be remembered for a revolution in biotechnology and medicine comparable to the advances made during the last century in physics.
Nanoscience is a similarly “hot” research topic. As all kinds of devices in our world become smaller and smaller, nanostructures of all types will find many uses.
All in all, the Lawrence Fellowship Program has been a resounding success in bringing new talent to the Laboratory and encouraging creativity and exciting science.
—Laurie Powers and Katie Walter

Key Words: Lawrence fellows, Lawrence Fellowship Program, postdoctoral positions.

For further information contact Harry Radousky (925) 422-4478 (radousky1@llnl.gov).


For information on the Lawrence Fellowship Program and other fellowship opportunities at the Laboratory, see these Web sites:
fellowship.llnl.gov/
www.llnl.gov/postdoc/

   


 



Back | S&TR Home | LLNL Home | Help | Phone Book | Comments
Site designed and maintained by Kitty Tinsley

Lawrence Livermore National Laboratory
Operated by the University of California for the U.S. Department of Energy

UCRL-52000-02-11 | December 16, 2002