| Aug.
10, 2005
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Chemical
Link Indicated between Alcohol and Certain Cancers
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Electron micrograph of
a single cell of breast cancer, one of the cancers for
which risk increases with alcohol consumption.
Source:
National Cancer Institute
view/download
high-resolution version |
Researchers
at the National Institute of Standards and Technology (NIST)
have developed a new chemical analysis method that has assisted
researchers at the National Institute of Alcohol Abuse and Alcoholism
(NIAAA), National Institutes of Health, in demonstrating a potentially
important chemical link between alcohol consumption and cancer.
Using this novel chemical assay, they have uncovered a chain
of chemical reactions that, under physiological conditions,
may lead from alcohol to a known mutagen.
It has
been known for years that there is a statistical relationship
between excessive alcohol consumption and an increased risk
of certain cancers, particularly upper gastrointestinal cancer.
Alcohol itself is not a carcinogen but is metabolized in
the
body to form a suspected carcinogen, acetaldehyde (AA). Then
the picture gets hazier. AA is known to react with 2’-deoxyguanosine
(dG)—one of the chemical components of DNA—however,
the main product does not appear to be mutagenic in mammals.
It also is known that AA can react with DNA to produce a known
mutagen (Cr-PdG**)—but only at very high concentrations
of AA that would not occur in the human body.
The missing
link, according to the NIAAA researchers, is a class of chemicals
called polyamines that are produced in cells and believed to
be involved in cell growth. Using a sensitive chemical analysis
technique called liquid chromatography/isotope-dilution mass
spectrometry developed at NIST, the team showed that AA reacts
with polyamines to produce crotonaldehyde (CrA). This in turn
reacts with dG in DNA to produce the mutagenic Cr-PdG.
An important
finding was that the reactions occurred at concentrations of
AA that can be found in human saliva after drinking alcohol,
while concentrations of AA in gastrointestinal tissues can be
even higher. The work strongly suggests that Cr-PdG plays a
key role in the pathway between alcohol consumption and cancer,
and that mutations in genes that encode proteins that repair
Cr-PdG and its derivatives could affect individual susceptibility
to cancer from alcoholic beverage consumption.
* J.A.
Theruvathu, P. Jaruga, R.G. Nath, M. Dizdaroglu and P.J. Brooks.
“Polyamines stimulate the formation of mutagenic 1,N2-propanodeoxyguanosine
adducts from acetaldehyde.” Nucleic Acids Research,
Vol. 33, No. 11, pp. 3513-3520 (2005).
** α-methyl-γ-hydroxy-1,
N2-propano-2’-deoxyguanosine
NIST
Demonstrates Better Memory with Quantum Computer Bits
Physicists
at the National Institute of Standards and Technology (NIST)
have used charged atoms (ions) to demonstrate a quantum
physics version of computer memory lasting longer than 10
seconds—more than 100,000 times longer than in previous
experiments on the same ions. The advance improves prospects
for making practical, reliable quantum computers (which
make use of the properties of quantum systems rather than
transistors for performing calculations or storing information).
Quantum computers, if they can be built, could break today’s
best encryption systems, accelerate database searching,
develop novel products such as fraud-proof digital signatures
or simulate complex biological systems to help design new
drugs.
As
described in the Aug. 5, 2005, issue of Physical
Review Letters,* NIST scientists stored information
in single beryllium ions for longer periods of time
by using a different
pair of the ions’ internal energy levels to represent 1
and 0 than was used in the group's previous quantum computing
experiments. This new set of quantum states is unaffected
by slight variations in magnetic fields, which previously
caused memory losses in ions stored in electromagnetic
traps.
Quantum
memory must be able to store “superpositions,”
an unusual property of quantum physics in which a quantum
bit (qubit) such as an ion represents both 0 and 1 at
the
same time. The new approach enables qubits to maintain
superpositions over 1 million times longer than might
be needed to carry
out the information processing steps in a future quantum
computer. The advance is, therefore, an important step
toward
the goal of designing a “fault tolerant” quantum
computer because it significantly reduces the computing
resources needed to correct memory errors.
In
related experiments also described in the paper, NIST scientists
demonstrated that pairs of “entangled” ions
can retain their quantum states for up to about 7 seconds.
Entanglement is another unusual property of quantum physics
that correlates the behavior of physically separated ions.
Superposition and entanglement are the two key properties
expected to give quantum computers great power.
The
research was supported by the Advanced Research and Development
Activity/National Security Agency. More information about
NIST's quantum computing research is available at http://qubit.nist.gov.
*
C. Langer, R. Ozeri, J.D. Jost, J. Chiaverini, B. DeMarco,
A. Ben-Kish, R.B. Blakestad, J. Britton, D.B. Hume, W.M.
Itano, D. Leibfried, R. Reichle, T. Rosenband, T. Schaetz,
P.O. Schmidt and D. J. Wineland. Long-lived qubit memory
using atomic ions. Physical Review Letters, 95,
060502 (2005).
Media
Contact:
Laura
Ost, laura.ost@nist.gov,
(301) 975-4034
Comprehensive
Database of Computer Vulnerabilities Now Available
Cyber
attackers are constantly scanning the Internet looking for vulnerabilities
in computer systems that will enable them to take control and
use the systems for illegal or unethical activities such as
identity theft, industrial espionage or distributing spam. For
those trying to prevent such attacks, keeping up with the 300
or so new vulnerabilities discovered each month can be an overwhelming
task, especially since a single flaw can be known by numerous
names.
The new
National Vulnerability Database (NVD) from the National Institute
of Standards and Technology (NIST) will make it easier for system
administrators and other security professionals to learn about
vulnerabilities and how to remediate them. The NVD is a comprehensive
database that integrates all publicly available U.S. government
resources on vulnerabilities and provides links to many industry
resources. NVD is built upon a dictionary of standardized vulnerability
names and descriptions called Common Vulnerabilities and Exposures.
Updated
daily, NVD currently contains information on almost 12,000 vulnerabilities.
It allows users to search by a variety of characteristics, including
vulnerability type, severity and impact; software name and version
number; and vendor name. NVD also can be used to research the
vulnerability history of a product and view vulnerability statistics
and trends.
NVD was
developed by researchers in NIST’s Computer Security Division
with support from the Department of Homeland Security’s
National Cyber Security Division. For more information, go to
http://nvd.nist.gov/.
Tandem
Ions May Lead the Way to Better Atomic Clocks
National
Institute of Standards and Technology (NIST) physicists
have used the natural oscillations of two different types
of charged atoms, or ions, confined together in a single
trap, to produce the “ticks” that may power
a future atomic clock.
As
reported in the July 29, 2005, issue of Science,*
the unusual tandem technique involves use of a single beryllium
ion to accurately sense the higher-frequency vibrations
of a single aluminum ion. The NIST group used ultraviolet
lasers to transfer energy from the aluminum’s vibrations
to a shared “rocking” motion of the pair of
ions, and then detected the magnitude of the vibrations
through the beryllium ion. The new technique solves a long-standing
problem of how to monitor the properties of an aluminum
ion, which cannot be manipulated easily using standard laser
techniques.
“Our
experiments show that we can transfer information back and
forth efficiently between different kinds of atoms. Now
we are applying this technique to develop accurate optical
clocks based on single ions,” said Till Rosenband
of NIST’s Time and Frequency Division in Boulder,
Colo.
The
tandem approach might be used to make an atomic clock based
on optical frequencies, which has the potential to be more
accurate than today’s microwave-based atomic clocks.
It also may allow simplified designs for quantum computers,
a potentially very powerful technology using the quantum
properties of matter and light to represent 1s and 0s.
The
work was supported in part by the Office of Naval Research
and the Advanced Research and Development Activity/National
Security Agency.
*P.O.
Schmidt, T. Rosenband, C. Langer, W.M. Itano, J.C. Bergquist
and D.J. Wineland. “Spectroscopy using quantum logic.”
Science, Vol. 309, Issue 5735, pp. 749-752 (2005).
Media
Contact:
Laura
Ost, laura.ost@nist.gov,
(301) 975-4034
First
Large-Scale Evaluation of Iris Recognition Under
Way
The National Institute of Standards
and Technology (NIST) has announced that it is running
the Iris Challenge Evaluation (ICE), the first large-scale
evaluation of iris recognition.
Iris recognition is a potentially
valuable biometric (a characteristic such as fingerprints
that can be used to identify a person). Previous
evaluations of iris recognition have concentrated
on the performance of systems. The ICE is the first
evaluation designed to measure the accuracy of the
underlying technology that makes iris recognition
possible.
The goals of the ICE are to (1)
promote the development and advancement of iris
recognition and (2) assess the technology’s
current level of performance. This will be accomplished
in two phases.
Phase I—which will be conducted
from now until the end of the year—will seek
researchers and developers from industry, research
institutions and academia who interested in participating
in iris recognition “challenge problems.”
Taking part in these “challenge problems”
(designed to promote technology development) will
give participants the opportunity to improve their
current performance rates and help prepare them
for ICE Phase II.
Phase II—tentatively scheduled
for the first quarter of 2006—will give iris
recognition system developers an opportunity to
take part in a large-scale, independent evaluation.
To guarantee accurate assessments, the ICE will
measure iris matching performance with sequestered
data (iris images not previously seen by the participants).
A standard dataset and test methodology will be
employed so that all participants are evaluated evenly.
The ICE is sponsored jointly by
the following federal agencies: NIST; two Department
of Homeland Security agencies—the Science
and Technology Directorate and the Transportation
Security Administration; two Department of Justice
agencies—the Federal Bureau of Investigation
and the National Institute of Justice; the Intelligence
Technology Innovation Center under the Office of
the Director of National Intelligence; and the
interagency
Technical Support Working Group, the U.S. national
forum that identifies, prioritizes and coordinates
interagency and international research and development
requirements for combating terrorism.
To learn more about the ICE and
access instructions on participating in the project,
go to http://iris.nist.gov/ICE.
Media
Contact:
Michael
E. Newman, michael.newman@nist.gov,
(301) 975-3025
Quick
Links
NIST
Workshop to Help Industry Meet New EU Regulations
The National
Institute of Standards and Technology (NIST) will
host a workshop this coming October to assist U.S.
manufacturers and their supply chain partners in meeting
new environmental regulations that restrict the use
of hazardous substances in electronics and a wide
range of consumer products.
An urgent
challenge faced by U.S. industry is compliance with
the European Union (EU) Directive on Restriction of
Certain Hazardous Substances in Electrical and Electronic
Equipment (RoHS), effective July 2006. RoHS restricts
lead (widely used in solder); mercury; cadmium; hexavalent
chromium (used to inhibit corrosion); and polybrominated
biphenyls (PBBs) and polybrominated diphenyl ether
(PBDE) flame retardants (in plastic housings of electrical
appliances).
Participants
in the NIST workshop will assess the measurement and
standards needs of U.S. manufacturers and suppliers
as they respond to the EU restrictions, and then collaboratively
produce a plan that addresses this issue to prevent
it from becoming a barrier to the global marketplace.
“The
Restricted Substances in Materials: Testing and Reporting
Procedures” workshop will be held at the NIST
campus in Gaithersburg, Md., from Oct. 5-7, 2005.
Registration and program information are at www.nist.gov/public_affairs/confpage/051005.htm.
Reporters interested in attending should contact Michael
Baum, michael.baum@nist.gov,
(301) 975-2763.
Guidelines
Issued for Certifying, Accrediting PIV Card Issuers
The National
Institute of Standards and Technology (NIST) has developed
guidelines for federal agencies to use in planning
and designing certification and accreditation procedures
for issuing Personal Identity Verification (PIV) cards
to employees and contractors. This is the next step
in the effort begun last February when NIST announced
Federal Information Processing Standard (FIPS) 201
for the smart-card-based form of identification. A
Presidential homeland security directive required
development of the government-wide, mandatory standard.
The directive also specified that card issuers must
be certified and accredited.
The certification
and accreditation process consists of four phases:
initiation, certification, accreditation and monitoring.
A set of tasks to be carried out by agency officials
is specified for each phase. The primary responsibilities
of a PIV card issuer include verifying the identity
and registering individuals to be issued a card, creating
and issuing PIV cards, and managing the life cycle
of the cards.
NIST
plans to review the guidelines in a year and revise
them based on additional information and experience
gained by agencies in implementing the standard, creating
and operating PIV card issuing processes, and certifying
and accrediting the reliability of card issuers. Guidelines
for the Certification and Accreditation of PIV Card
Issuing Organizations (NIST Special Publication
800-79) and additional information on the PIV standard
is available at http://csrc.nist.gov/piv-program/index.html.
New
Guide Is Timely for Radio Controlled Clocks,
Watches
Got the
correct time? Radio controlled clocks and watches
that automatically synchronize to official U.S. time
provided by the National Institute of Standards and
Technology (NIST) have become more popular as prices
drop and style choices increase. Sometimes called
“atomic timepieces,” these devices receive
their time from NIST radio station WWVB located near
Ft. Collins, Colo., which is indirectly referenced
to the NIST-F1 cesium fountain atomic clock in Boulder,
Colo. WWVB broadcasts its signal throughout the nation
at 60 kilohertz to clocks and watches with miniature
radio receivers tuned to that frequency.
A
new booklet and accompanying Web page produced
by NIST’s
time and frequency experts offer consumers advice
on choosing the radio controlled clock or watch
that
best suits their needs. For those already owning
a WWVB-tuned timepiece, the guide provides tips
on fixing
several common operating problems. For manufacturers,
the document recommends best practices for clock
control,
synchronization methods, time-zone settings, daylight
savings time practices, hardware specifications
and
other topics.
The
brochure, WWVB Radio Controlled Clocks: Recommended
Practices for Manufacturers and Consumers, may
be downloaded from http://tf.nist.gov/timefreq/stations/radioclocks.htm.
A print copy can be requested by phone at (303) 497-4343,
or e-mail at sp960@boulder.nist.gov.
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