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March 25, 2004

  In This Issue:
bullet World's Best "Rulers" Will Make Better Clocks
bullet Standard Helps ID Fuels Used in Arson
bullet Genes Appeared Before "Junk" DNA

Toolkit for Evaluating Public R&D Funding

bullet Quick Links

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World's Best "Rulers" Will Make Better Clocks

Scientist wearing dark goggles turns knob to adjust a green laser reflecting off mirrors on a laboratory table.
© 2004 Bruce Erik Steffine

NIST physicist Scott Diddams adjusts a femtosecond laser system that is an important component of next-generation atomic clocks based on optical rather than microwave frequencies.

Lasers that emit pulses of light lasting just 10 femtoseconds (10 quadrillionths of a second) can reliably measure time and frequency more precisely than any other "rulers," according to recent tests conducted at the National Institute of Standards and Technology (NIST).

The experiments demonstrated that femtosecond laser devices could be used to reproducibly generate and accurately control wavelengths of light to serve as the "gears" that translate ultrahigh frequency "ticks" from next-generation optical atomic clocks into practical electronics-based timekeeping. Applications for ultra-precise timekeeping include navigation, telecommunications and basic scientific research.

The devices are called "frequency combs" because a graph of the oscillating electromagnetic waves looks like the teeth of a hair comb. The experiments are the first to compare the operation of multiple femtosecond frequency combs—thereby demonstrating reproducibility—and to verify that both the starting position of a comb and the spacing between the teeth can be controlled precisely.

The work, described in the March 19, 2004, issue of the journal Science, is a significant step toward next-generation "atomic clocks" based on optical rather than microwave frequencies. Such clocks are expected to be as much as 100 times more accurate than today's best timekeeping systems. A frequency comb would work like the gears in a transmission to convert the very fast oscillations of optical clocks into lower frequency signals that can be compared with current primary timekeeping standards based on microwave sources. The signal then could be distributed with conventional electronics through the Global Positioning System and broadcasts from NIST's time signal radio stations.

The scientific team compared the operation of four femtosecond laser systems of different designs—two built at NIST, one by the Bureau International des Poids et Mesures in France, and one by East China Normal University in Shanghai. The three labs collaborated on the tests along with OFS Laboratories in New Jersey.

For more information, see

Media Contact:
Laura Ost, (301) 975-4034



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Standard Helps ID Fuels Used in Arson

Faced with a growing number of ignitable chemicals with similar characteristics, arson investigators have their hands full trying to tell residues of insecticide, for example, from those of gasoline. But identifying fuels used to set fires will be easier now, thanks to some help from the National Institute of Standards and Technology (NIST).

Law enforcement agencies, insurance fraud investigators and forensic services are expected to use Standard Reference Material (SRM) 2285, NIST's first standard intended to aid arson investigations. The new SRM is a liquid containing 15 compounds from common accelerants in various certified concentrations. It will be used to calibrate instruments that help analysts classify fire scene residues into six categories of fuels.

The hydrocarbon compounds are separated and identified based on how long it takes for them to pass through an instrument called a gas chromatograph. The retention time depends partly on a compound's volatility, or how fast it changes from liquid to vapor, and partly on experimental conditions such as temperature. Users analyze the SRM, analyze the residue from the crime scene and compare the retention time patterns to help identify the components used at the fire.

The instruments' readouts indicate both the presence and concentration of the various components; these patterns may indicate a particular fuel source. In helping investigators accurately identify the components and thus the original fuel used to set a fire, the SRM may help improve the 2 percent national conviction rate for arson cases. SRM 2285 also may be useful in the petroleum industry and environmental science.

Media Contact:
Laura Ost, (301) 975-4034



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Genes Appeared Before "Junk" DNA

A rigorous statistical analysis of so-called "junk" DNA from a wide variety of biological kingdoms (plants, animals, fungi, etc.) has shown that this mysterious genetic material was added late in the evolution of life on earthafter the formation of modern-sized genes that contain instructions for making proteins.

The new research appears to resolve a debate about whether "introns"—sections of DNA with unknown function plopped in the middle of genes—were present in ancient life forms or appeared for the first time after bacteria and higher organisms split into separate evolutionary paths billions of years ago.

The work was conducted at the Center for Advanced Research in Biotechnology (CARB), which is jointly operated by the National Institute of Standards and Technology (NIST) and the University of Maryland Biotechnology Institute. A Furman University researcher collaborated on the project. Their findings are reported in the March 10 online edition of Molecular Biology and Evolution.

Using publicly available genetics sequences, the CARB study analyzed data for 10 families of protein-coding genes in animals, plants, fungi and their relatives, encompassing 1,868 introns at 488 different positions. While most such studies work with one genetic sequence family at a time, the CARB study developed software to automate the analysis of dozens of sequence families simultaneously.

The new results refute a once-popular theory that introns may have served as genetic glue to assemble modern-sized genes out of ancient mini-genes. The CARB analysis shows that the probability of a modern intron's presence in an ancestral gene common to the genes studied is roughly 1 percent, indicating that the vast majority of today's introns appeared after the origin of the genes.

For further information, see

Media Contact:
Laura Ost, (301) 975-4034




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Toolkit for Evaluating Public R&D Funding

It’s hard to measure innovation. While public support for research and development long has been recognized as an important tool for enhancing economic growth, determining which programs are most effective has been problematic for just as long.

The Advanced Technology Program (ATP) at the National Institute of Standards and Technology (NIST) has more than 14 years of experience evaluating R&D and has been recognized by the National Research Council for setting “a high standard for assessment.” Using a variety of research tools, including surveys, econometric models, detailed case studies and literature analysis, ATP economists have assembled a significant body of research and data on the innovation process and contributed to the development of the academic theory on assessing R&D programs.

A new ATP publication, A Toolkit for Evaluating Public R&D Investment, assembles in one volume a decade’s worth of ATP experience in the measurement of innovation, including a general framework for evaluation, a discussion of an evaluation logic model, fundamentals and methods, demonstrations of the ATP’s use of evaluation methods, and a summary of an emerging body of knowledge from ATP studies on firm behavior, collaboration, spillover effects, interfaces with state and international technology programs, and the overall performance of the program. It also includes a glossary of terms, methods bibliography and a quick reference guide to evaluation models and methods.

Single copies of the toolkit are available by writing the Economic Assessment Office, Advanced Technology Program, NIST, 100 Bureau Drive, Mail Stop 4710, Gaithersburg, MD 20899-4710, or by sending an e-mail to The report also is available on-line at

Media Contact:
Michael Baum, (301) 975-2763


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Quick Links

Quantum Information Science and Emerging Technologies—A workshop designed to engage industry representatives in a continuing dialogue with the National Institute of Standards and Technology (NIST) and other federal agencies on emerging quantum information technologies will take place on April 28-30, 2004, at NIST's facilities in Boulder, Colo. The meeting will provide an introduction to quantum computing and communications, descriptions of current research results in the field, a review of federal perspectives, and opportunities for industry comment on NIST program directions. For further information, see

NIST Research Library and Librarian Receive Top Honors—The Federal Library and Information Center Committee at the Library of Congress recently named the NIST Research Library as its Federal Library/Information Center of the Year. The NIST library was recognized "for its technological innovations and comprehensive knowledge management systems that proactively provide the tools necessary to support new programs, superior customer service and the agency mission." Additionally, NIST's Wilma (Sissy) Riley was named Federal Library Technician of the Year. For more details, go to


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Editor: Gail Porter

Date created: 3/11/2004
Date updated: 3/22/2004