bluuebunny/crossref_metadata_2025 huggingface dataset:
Field emission arrays by silicon micromachining
Authors: Debski T. , Volland B. , Barth W. , Shi F. , Hudek P. , Rangelow I. W. , Grabiec P. , Studzinska K. , Zaborowski M. , Mitura S.
Published: July 2002

A new method for the fabrication of field emission arrays based on bulk/surface silicon micromachining and diamond-like carbon coating was developed. A matrix of self-aligned electron field emitters is formed in silicon wafers. Anisotropic etching in alkali solution of the front silicon film through micropatterned holes opened in a hard masking trilayer results in microtip pixels. The field emission of the emitter tips is enhanced by a diamond-like-carbon (DLC) film formed by chemical vapor deposition on the microtips. The DLC coating allows a field-emission current of about 80 μA per tip at 300 V and a distance of 60 μm. High accuracy of patterning combined with batch processing enables cost effective production of dense arrays. Flat panel displays, electrostatic scrubbers and other applications requiring efficient electron emission are among the possible applications of the proposed technology.
Ar/N
2
O
remote plasma-assisted oxidation of Si(100): Plasma chemistry, growth kinetics, and interfacial reactions
Authors: Smith Bradley C. , Khandelwal Amit , Lamb H. Henry
Published: July 2002

The kinetics of Ar/N2O remote plasma-assisted oxidation of Si(100) and the mechanism of nitrogen incorporation at the Si–SiO2 interface were investigated using mass spectrometry, optical emission spectroscopy, and on-line Auger electron spectroscopy. N2, O2, and NO are the stable products of N2O dissociation in the plasma. The maximum NO partial pressure occurs at 10 W applied rf power; N2 and O2 are the predominant products for applied powers greater than 50 W. Ar/N2O remote plasmas are prolific sources of atomic O; in contrast, atomic N is not produced in significant concentrations. Ar/N2O remote plasma-assisted oxidation was investigated at 300 °C for applied rf powers of 5, 20, and 50 W. The oxide growth kinetics are slower than expected for a purely diffusionally controlled process. A diffusion-reaction model that incorporates first-order loss of the oxidizing species as it diffuses through the growing oxide layer fits the data very well. The initial oxidation rate increases linearly with plasma density, suggesting that the near-surface concentration of oxidizing species scales with the surface flux of plasma electrons. Nitrogen is incorporated at the Si–SiO2 interface in direct proportion to the N2 partial pressure in the Ar/N2O remote plasma. Molecular NO does not react at the Si–SiO2 interface at 300 °C, its role in Si thermal oxynitridation notwithstanding. Nitrogen incorporation at the Si–SiO2 interface was also achieved by exposure of ultrathin Ar/O2 plasma oxides to a remote 20 W Ar/N2 plasma.
Holy Landscapes!
Authors: Mallet James
Published: July 2002

Epistasis and the Evolutionary Process
. Jason B. Wolf, Edmund D. Brodie III, and Michael J. Wade, Eds. Oxford University Press, New York, 2000. 344 pp. $85, £62.50. ISBN 0-19-512806-0.

The contributors demonstrate that the interactions of genes in their effects on fitness play important roles in a wide range and interesting range of evolutionary problems.
Another World Food Scare?
Authors: Sanders John H.
Published: July 2002

Food's Frontier
The Next Green Revolution. Richard Manning. North Point (Farrar, Straus, and Giroux), New York, 2000. 233 pp. $24, C$38.95. ISBN 0-86547-593-8.

Manning argues that we have reached the limits of what the Green Revolution of the 1960s can do to supply food to a still growing world population. He discusses nine ongoing projects that are experimenting with potential means of further increases in food production, including indigenous knowledge, native crops, and biotechnology.
Teaching Healing and Healing Teaching
Authors: Petersdorf Robert G.
Published: July 2002

Time to Heal
American Medical Education from the Turn of the Century to the Era of Managed Care. Kenneth M. Ludmerer. Oxford University Press, New York, 1999. 540 pp. $29.95. ISBN 0-19-511837-5.

Ludmerer discusses the web of interactions among medical schools, teaching hospitals, and the health care system that have shaped the evolution of medical education in the United States since World War I. His narrative ends with a consideration of the challenges offered by the current environment of managed care.
Imaging and Photometry of Comet C/1999 S4 (LINEAR) Before Perihelion and After Breakup
Authors: Farnham Tony L. , Schleicher David G. , Woodney Laura M. , Birch Peter V. , Eberhardy Clara A. , Levy Lorenza
Published: July 2002

We analyzed photometric measurements and images of comet C/LINEAR before perihelion and after its breakup. Results from our photometry data include a lower limit of 0.44 kilometer for the radius of the nucleus before breakup, and a determination that it was depleted in carbon-chain molecules relative to most other comets. Our imaging and modeling results, which include a constraint on the rotational state of the nucleus, indicate that the disintegration likely started on 18 or 19 July 2000. The total mass detectable in the dust tail after the breakup was 3 × 10
8
kilograms, comparable to one of the fragments in the Hubble Space Telescope images; we therefore infer that most of the comet's original mass is hidden in remnants between 1 millimeter and 50 meters in diameter.
Complexities of a Controversial Practice
Authors: Obermeyer Carla Makhlouf
Published: July 2002

Female "Circumcision" in Africa
Culture, Controversy, and Change. Bettina Shell-Duncan and Ylva Hernlund, Eds. Lynne Rienner, Boulder, CO, 2000. $59.95. ISBN 1-55587-871-7. Paper, $22.50. ISBN 1-55587-995-0.

The Female Circumcision Controversy
An Anthropological Perspective. Ellen Gruenbaum. University of Pennsylvania Press, Philadelphia, 2001. 250 pp. $55, £39. ISBN 0-8122-3573-8. Paper, $24.95, £17.50. ISBN 0-8122-1746-2.

These two books consider social, historical, political, and public health aspects of female "circumcision." The authors include women from countries where the practice is prevalent.
Crime-solving Bugs
Authors: Byrd Jason H.
Published: July 2002

Maggots, Murder and Men
Memories and Reflections of a Forensic Entomologist. Zakaria Erzinçlioglu. Harley, Colchester, UK. Paper, 256 pp. £13.95. ISBN 0-946589-65-8.

Well known for his involvement in several high-profile cases in Great Britain, Erzinçlioglu discusses examples ranging from mythology to the present day in this enjoyable account of the application of insect biology to the investigation of crimes.
Acoustic Oscillations in the Early Universe and Today
Authors: Miller Christopher J. , Nichol Robert C. , Batuski David J.
Published: July 2002

During its first ≃100,000 years, the universe was a fully ionized plasma with a tight coupling by Thompson scattering between the photons and matter. The trade-off between gravitational collapse and photon pressure causes acoustic oscillations in this primordial fluid. These oscillations will leave predictable imprints in the spectra of the cosmic microwave background and the present-day matter-density distribution. Recently, the BOOMERANG and MAXIMA teams announced the detection of these acoustic oscillations in the cosmic microwave background (observed at redshift ≃ 1000). Here, we compare these CMB detections with the corresponding acoustic oscillations in the matter-density power spectrum (observed at redshift ≃ 0.1). These consistent results, from two different cosmological epochs, provide further support for our standard Hot Big Bang model of the universe.
Ring Closure of Carbon Nanotubes
Authors: Sano Masahito , Kamino Ayumi , Okamura Junko , Shinkai Seiji
Published: July 2002

Lightly etched single-walled carbon nanotubes are chemically reacted to form rings. The rings appear to be fully closed as opposed to open coils, as ring-opening reactions did not change the structure of the observed rings. The average diameter of the rings was 540 nanometers with a narrow size distribution. The nanotubes in solution were modeled as wormlike polymer chains, yielding a persistence length of 800 nanometers. Nanotubes shorter than this length behave stiffly and stay nearly straight in solution. However, nanotubes longer than the Kuhn segment length of 1600 nanometers undergo considerable thermal fluctuation, suggesting a greater flexibility of these materials than is generally assumed.
Pathways to Dependency
Authors: Mendelson Jack H.
Published: July 2002

Forces of Habit
Drugs and the Making of the Modern World. David T. Courtwright. Harvard University Press, Cambridge, MA, 2001. $24.95. ISBN 0-674-00458-2.

Courtwright's historical approach examines the social and biological factors that have made certain drugs so seductive. He addresses such questions as why coffee, tobacco, and marijuana have spread around the world while peyote and qat have not, and why alcohol and tobacco are legal but heroin and cocaine are not.
Nota Bene: Some Things Never Change
Authors: Uppenbrink Julia
Published: July 2002

Oxygen
. Carl Djerassi and Roald Hoffmann. Wiley-VCH, New York, 2001. 128 pp. Paper, $14.95, £9.99. ISBN 3-527-30413-4.

Oxygen
. Carl Djerassi and Roald Hoffmann. Lyceum Theatre, San Diego, CA, 2 to 7 April 2001. See
www.djerassi.com/oxygen/oxygen2.html
for future performances.

Who discovered oxygen: Scheele, Priestly, or Lavoisier? Hoping to combine entertainment and education, two renowned chemists turned playwrights consider the question by creating a 1777 meeting of the protagonists and a committee to award "retro-Nobels."
Nostril Position in Dinosaurs and Other Vertebrates and Its Significance for Nasal Function
Authors: Witmer Lawrence M.
Published: July 2002

Many dinosaurs have enormous and complicated bony nasal apertures. Functional interpretation requires knowledge of the location of the external opening in the skin. Traditionally, the fleshy nostril of dinosaurs has been placed in the back of the bony opening, but studies of extant dinosaur relatives suggest that it is located far forward. Narial blood supply and cavernous tissue corroborate the rostral position in dinosaurs. A rostral nostril was, and remains, a virtually invariant rule of construction among Amniota, which has consequences for (i) nasal airstreaming, and hence various physiological parameters, and (ii) the collection of behaviorally relevant circumoral odorants.
Nota Bene: Are You Ready?
Authors: Smith Orla
Published: July 2002

The Genomic Revolution
. Rob DeSalle, Curator. American Museum of Natural History, New York. 26 May 2001 to 1 January 2002.
www.amnh.org/exhibitions/genomics/

The eight sections of this ambitious exhibition offer visitors an introduction to the study of genes and their functions as well as the implications of genomics for our health, surroundings, and future.
Experimental Realization of Noiseless Subsystems for Quantum Information Processing
Authors: Viola Lorenza , Fortunato Evan M. , Pravia Marco A. , Knill Emanuel , Laflamme Raymond , Cory David G.
Published: July 2002

We demonstrate the protection of one bit of quantum information against all collective noise in three nuclear spins. Because no subspace of states offers this protection, the quantum bit was encoded in a proper noiseless subsystem. We therefore realize a general and efficient method for protecting quantum information. Robustness was verified for a full set of noise operators that do not distinguish the spins. Verification relied on the most complete exploration of engineered decoherence to date. The achieved fidelities show improved information storage for a large, noncommutative set of errors.
Twitching Butterflies
Authors: Ehrlich Paul R.
Published: July 2002

Butterflies Through Binoculars
A Field Guide to the Butterflies of Western North America. Jeffrey Glassberg. Oxford University Press, New York, 2001. 384 pp. Paper, $19.95. ISBN 0-19-510669-5.

In this companion to a previous volume for eastern North America, Glassberg provides photographs of butterflies in their natural habitats along with a text that will encourage people to find, identify, and enjoy western butterflies without capturing them.
Studied Ambiguity
Authors: Rorty Richard
Published: July 2002

Shaping Science with Rhetoric
The Cases of Dobzhansky, Schrödinger, and Wilson. Leah Ceccarelli. University of Chicago Press, Chicago, 2001. 216 pp. $55, £35. ISBN 0-226-09906-7. Paper, $20, £13. ISBN 0-226-09907-5.

Ceccarelli uses close readings of Dobzhansky's
Genetics and the Origins of Species
, Schrödinger's
What is Life?
, and Wilson's
Consilience
to address the questions of how scientists build interdisciplinary programs and why some efforts to do so result in widespread acclaim while others fail.
Also Sprach
Homo mutans
Authors: Johnson Norman A.
Published: July 2002

Shrinking the Cat
Genetic Engineering Before We Knew About Genes. Sue Hubbell. Houghton Mifflin, Boston, 2001. 191 pp. $25. ISBN 0-618-04027-7.

To provide a background for considering possible benefits and drawbacks of genetic engineering, Hubbell discusses the successes and failures from centuries of selective breeding and tinkering with corn, silkworms, cats, and apples.
Learning Limits from Failures
Authors: Dumas Lloyd J.
Published: July 2002

Inviting Disaster
Lessons from the Edge of Technology. James R. Chiles. HarperBusiness, New York, 2001. 352 pp. $28, C$42.50. ISBN 0-06-662081-3.

Examining a number of disasters and near-misses that arose through failures to control modern technology, Chiles discusses ways in which similar events might be avoided in the future.
The Pill in Context
Authors: Schiebinger Londa
Published: July 2002

Sexual Chemistry
A History of the Contraceptive Pill. Lara V. Marks. Yale University Press, New Haven, CT, 2001. 384 pp. $29.95, £20. ISBN 0-300-08943-0.

Marks argues that the usual focus on the efforts of male scientists has hidden the important roles women played in initiating, funding, and supporting the development and use of the pill.
Nota Bene: The Kitchen Chemist
Authors: Lavine Marc
Published: July 2002

The Science of Cooking
. Peter Barham. Springer, Berlin, 2001. 252 pp. $34.95, £19.95. ISBN 3-540-67466-7.

Barham uses a collection of illustrative recipes to present the chemistry and physics behind the processes of food preparation and cooking.
Fine Battlefield Reporting, But It's Time to Stop the War Metaphor
Authors: McMichael Tony
Published: July 2002

Secret Agents
The Menace of Emerging Infections. Madeline Drexler. Joseph Henry (National Academy), Washington, DC, 2002. 326 pp. $24.95, C$34.95. ISBN 0-309-07638-2.

Writing for a broad, popular audience, Drexler discusses a variety of dangers posed by microbial pathogens.
Nota Bene: Depictions of Travels Imagined
Authors: Ash Caroline , Uppenbrink Julia
Published: July 2002

Visions of Spaceflight
Images from the Ordway Collection. Frederick I. Ordway III. Four Walls Eight Windows, New York, 2001. 176 pp. $50. ISBN 1-56858-181-5.

Sampling Ordway's renowned personal collection, the book surveys depictions of human dreams of space travel through the five centuries before Sputnik.
Keeping Pace with Opportunistic DNA
Authors: Kidwell Margaret G.
Published: July 2002

Lateral DNA Transfer
Mechanisms and Consequences. Frederic Bushman. Cold Spring Harbor Laboratory Press, Cold Spring Harbor, NY, 2002. 464 pp. $59, £43. ISBN 0-87969-603-6. Paper, $39, £28. ISBN 0-87969-621-4.

Readers from graduate students to established researchers will find much of interest in Bushman's discussions of how lateral transfer occurs, the extent to which it happens, its implications for our understanding of biology, and its consequences for medicine.
A Hawking-eye View of the Universe
Authors: Kamionkowski Marc
Published: July 2002

The Universe in a Nutshell
. Stephen Hawking. Bantam, New York, 2001. 224 pp. $35, C$53, £20. ISBN 0-553-80202-X.

In this lavishly illustrated volume, Hawking offers lay readers an accessible introduction to topics ranging from the shape of time to branes and holography.
Lessons from a Slow Leak
Authors: Schulman Paul
Published: July 2002

Silent Spill
The Organization of an Industrial Crisis. Thomas D. Beamish. MIT Press, Cambridge, MA, 2002. 232 pp. $55, £37.95. ISBN 0-262-02512-4. Paper, $21.95, £14.95. ISBN 0-262-52320-5.

Beamish offers a sociological perspective on a persistent and long-ignored oil spill in the Guadalupe Dunes of coastal California. He presents the case as an example of the sorts of environmental accidents that are neglected because they do not lead to dramatic destruction or disruption.
Dealing with Disaster
Authors: Adams Robert McC.
Published: July 2002

Catastrophe & Culture
The Anthropology of Disaster. Susanna M. Hoffman and Anthony Oliver-Smith, Eds. School of American Research Press, Santa Fe, 2002. James Currey, Oxford, 2002. 324 pp. $60. ISBN 1-930618-14-X. £45. ISBN 0-85255-925-9. Paper, $24.95. ISBN 1-930618-15-8. £16.99. ISBN 0-85255-926-7.

The contributors discuss a variety of events--Bhopal, the Exxon Valdez, Chernobyl, Mexican earthquakes, drought in Africa and in the Andes, the 1991 brush fire in Oakland--to explore how human actions and natural forces combine to turn hazards into disasters. They also discuss how anthropology can help shape more effective responses to natural catastrophes.
CERN Sets Sights on an Early LHC
Authors: Hellemans Alexander
Published: July 2002

Paris—CERN, the European particle physics center near Geneva, got a mixed message from its governing council last month. The council voted unanimously to put CERN's next grand project, the Large Hadron Collider (LHC), on a “fast track.” It should now be completed in a single stage by 2005—3 years ahead of the original schedule. But the council also agreed to a series of cuts in the rest of CERN's budget that could badly squeeze other experiments.
New Funds Plant Seeds for Genome Research Effort
Authors: Kahn Patricia
Published: July 2002

Melbourne—As biologists Down Under prepared last month to head off for a Christmas of sun and surf, they had an extra reason for holiday cheer: two government decisions that will add meat to the country's innovative but meagerly funded foray into the world of genome research.
Evolutionary Psychologists Look for Roots of Cognition
Authors: Williams Nigel
Published: July 2002

London—The effort to put human mental activity under the evolutionary spotlight is triggering a remarkable burst of collaboration between biologists and psychologists. Thirty of them recently gathered at a workshop here to discuss recent findings. Among them are results implying deep evolutionary roots for the mental mechanisms behind numeracy—the ability to assess bulk or amount—and the tendency to discount future rewards in favor of present ones.
Pax Polio
Authors: Hull Harry F.
Published: July 2002

Hull outlines how immunization programs for children have had positive political effects throughout the world.
There Are GAPS and There Are GAPS
Authors: Iyengar Ravi
Published: July 2002

Guanine nucleotide-binding proteins (G proteins) transduce a very large number of cellular regulatory signals. Several recent papers have shown that the larger heterotrimeric G proteins are regulated by a class of molecules known as the RGS proteins (regulators of G protein-signaling family) that are analogous to the GAPs (GTPase activating proteins), which regulate small monomeric G proteins. Iyengar summarizes this evidence and discusses the mechanism of action of the RGS proteins.
Science Academies Set Joint Agenda
Authors: Mervis Jeffrey
Published: July 2002

Ties between the U.S. National Academy of Sciences and the Chinese Academy of Sciences, frayed since the events at Tiananmen Square in 1989, were repaired last week as the leaders of the two organizations met in Beijing. The two academies agreed to begin holding a series of meetings between young scientists from both countries and discussed support for joint research projects in energy and sustained development.
The Gathering Darkness
Authors: Glanz James
Published: July 2002

Black holes are flourishing in theorists' computers and on their blackboards (see
related item
). But these objects—the children of Einstein's theory of gravity—are also alive and well in the universe, observers are finding. They are detecting increasingly strong signs of black holes at the centers of galaxies and, closer to home, in turbulent x-ray beacons.
Much-Studied Butterfly Winks Out on Stanford Preserve
Authors: McGarrahan Ellen
Published: July 2002

After a long decline, the threatened bay checkerspot butterfly has disappeared from Stanford University's Jasper Ridge preserve. While this local extinction isn't yet a certainty, it has raised entomological eyebrows: Paul Ehrlich and others at Stanford chose to watch the population die off, saying more could be learned from watching it disappear than from intervening to try to save it. Their decision highlights a dilemma that many conservation biologists face—when should scientists studying a shrinking population intervene to try to save it?
Early Evolution of Continents
Authors: Hofmann A. W.
Published: July 2002

How did the continents form, and how long ago? These questions have been the subject of debate for 30 years. As Hofmann discusses in his Perspective, results reported by Sylvester
et al
. (
p. 521
) reveal that measurements of niobium and uranium isotopes indicate that ancient rocks from Western Australia are indistinguishable from modern mantle rock. This finding suggests that the mass and extent of continents today is comparable to that 2.7 billion years ago.
Science in Chile
Authors: Saavedra Ivan N.
Published: July 2002

Science is essential for developing countries. It contributes to their cultural growth and quality of life and permits the transfer of creative applications of knowledge to solve major problems that prevent the global development of these countries. Indicators reveal that Chile is in a leading position in terms of scientific productivity per capita in Latin America (Science in Latin America, 10 Feb. 1995,
p. 819
). Part of this growth can be explained by an 8.7% increase in gross industrial product invested in science and the effects of the National Fund for Scientific and Technological Development established in the early 1980s by the National Commission for Scientific and Technological Research (CONICYT). This system guarantees the maintenance of basic research activity. However, several outstanding laboratories have research programs that generate most of the Chilean research contribution recognized worldwide, and they require additional stimulus if they are to have any impact on Chile's development.

The main problem has been how to channel the scientific creativity of talented scientists so they can express their full potential. A ray of hope emerged 2 years ago when CONICYT proposed a plan to add renewed energy to the gradually growing process to open up possibilities for a more significant participation of Chilean scientists in the world. Unfortunately, this plan did not succeed because the interests of particular groups prevailed. The idea of stimulating the strongest research teams was transformed into a “presidential chair” system emanating from the presidential office instead of CONICYT.

CONICYT is the only national agency for science in Chile, with a structure and organization that have led to a long-standing record of peer-reviewing proposals and tracking investigators' accomplishments. But with decisions in the hands of a study section made up of members of a presidential advisory committee (with the help of a panel of one representative foreign scientist per area), the “presidential chairs” in most cases were not awarded to Chile's most talented scientists.

An obvious strategy to foster scientific growth in countries like Chile is to stimulate those groups of investigators and laboratories that have demonstrated that they are highly competitive in their fields and that they have surmounted the difficulties of carrying out science in Latin America. The “presidential chairs” system, however, is an example of how a significant investment in science can fail to reach its objective when inappropriate evaluation systems are in place and scientific quality is not considered a major goal.
Biotechnology: Hype Surrounds Genomics Inc.
Authors: Cohen Jon
Published: July 2002

Academics, researchers at older biotech and big pharmaceutical companies, and even some stock analysts worry that the promise of genomics is being oversold. As one prominent researcher puts it, “For a number of genetic diseases, knowing the genes might not help the patient one whit.”
ORI's Self-Assessment: A Batting Average of .920?
Authors: Friedly Jock
Published: July 2002

Earlier this month, the Office of Research Integrity (ORI) issued a statistical report indicating that it has overcome its most serious troubles of the past. ORI says that it is processing cases much faster, and since 1992, it has achieved an eye-popping 92% success rate in sustaining guilty findings. The report also reveals the crushing workload of apparently trivial cases that get referred to ORI, the vast majority of which it decides not to pursue.
First Floridians Found Near Biscayne Bay
Authors: Morell Virginia
Published: July 2002

SEATTLE
—Newly dated fish bones and artifacts reveal that Indians were basking in the Florida sun almost 10,000 years ago. The finding, reported at the annual meeting of the American Association for the Advancement of Science here, pushes back by at least 3000 years the time that people are known to have inhabited the Atlantic Coast of North America.

See last week's issue (
Science
, 21 February, p.
1061
1061) for coverage of early sessions on
global R&D funding
and
submarine vents
.
All-Star Group Prescribes Partnerships for R&D Woes
Authors: Cohen Jon
Published: July 2002

LA JOLLA, CALIFORNIA
—An all-star cast of politicians, academics, and industry leaders gathered here last week to discuss strengthening the R&D enterprise in the United States. Many of the participants favored one prescription in particular: partnerships.
New Tax Code Threatens Science Funds
Authors: Allakhverdov Andrey , Pokrovsky Vladimir
Published: July 2002

MOSCOW
—Late last month, the Russian Cabinet approved the draft of a new tax code for the country which, if approved by parliament in its current form, would deprive research institutions of almost all the tax exemptions and concessions they currently enjoy. With Russia's research institutes already teetering on the brink of extinction because of shrinking budgets, this new burden may be enough to tip many of them over the edge.
Charges Fly Over Advocacy Research
Authors: Friedly Jock
Published: July 2002

Brooklyn College's science faculty has leveled what amounts to a fraud indictment against the New York Public Interest Research Group, based on what the faculty calls faulty logic in studies of recycling, SAT scores, and the Audi 5000 car. The charge, in a petition signed by 65 faculty members, raises the thorny question of whether reports by an advocacy group—even if they contain no original data—should be held to the same standards used to judge peer-reviewed science.
Pulses of Rapid Ventilation in the North Atlantic Surface Ocean During the Past Century
Authors: Druffel Ellen R. M.
Published: July 2002

The Suess Effect is a gradual decrease of the
14
C/
12
C ratio in tree rings from 1870 to 1950 that is attributed mostly to the burning of
14
C-free fossil fuels for energy. In contrast, pre-nuclear bomb high-precision measurements of
14
C/
12
C ratios in banded corals from the North Atlantic Ocean do not exhibit the expected Suess Effect. Instead, large biennial-to-decadal shifts in the
14
C/
12
C ratios appear throughout the coral records. This pattern indicates that rapid pulses of increased mixing between surface and subsurface waters occurred in the North Atlantic Ocean during the past century.
Is a Great Plateau Slip-Sliding Away?
Authors: Kerr Richard A.
Published: July 2002

The American West may be high, but it's slowly sinking—and sliding northwest toward the Oregon coast, according to a new geophysical theory.
The Weighty Matter of Names
Authors: Stokstad Erik
Published: July 2002

Signaling an end to pitched battles between rival labs, an international commission of chemists last month presented a revised list of names for elements 104 to 109 to chemistry's high court, the International Union of Pure and Applied Chemistry. IUPAC will rule on the names this August.
Consciousness Research: Visual System Provides Clues to How the Brain Perceives
Authors: Barinaga Marcia
Published: July 2002

Ten years ago, any neurophysiologist who claimed to be looking for the neural basis of consciousness would have had a tough time being taken seriously. But that is changing as researchers recognize that consciousness can be broken down into pieces that can be tackled by the techniques of modern neurobiology. In particular, studies of the visual system are beginning to show how the neurons along the visual pathway come to represent what we actually perceive and not just what registers on the retina.
Tagging T Cells—T
H
1 or T
H
2?
Authors: Gallagher Richard
Published: July 2002

Two papers in the
Journal of Experimental Medicine
report the identification of a marker on the cell surface of T helper cells that can distinguish between the two main cell types, T
H
1 and T
H
2. This marker, the IL-12 receptor beta chain, will be useful for monitoring these important cell types, as well as providing a potential therapeutic target.
Borehole Temperatures and a Baseline for 20th-Century Global Warming Estimates
Authors: Harris Robert N. , Chapman David S.
Published: July 2002

Lack of a 19th-century baseline temperature against which 20th-century warming can be referenced constitutes a deficiency in understanding recent climate change. Combination of borehole temperature profiles, which contain a memory of surface temperature changes in previous centuries, with the meteorological archive of surface air temperatures can provide a 19th-century baseline temperature tied to the current observational record. A test case in Utah, where boreholes are interspersed with meteorological stations belonging to the Historical Climatological Network, yields a noise reduction in estimates of 20th-century warming and a baseline temperature that is 0.6° ± 0.1°C below the 1951 to 1970 mean temperature for the region.
High-Pressure Iron-Sulfur Compound, Fe
3
S
2
, and Melting Relations in the Fe-FeS System
Authors: Fei Yingwei , Bertka Constance M. , Finger Larry W.
Published: July 2002

An iron-sulfur compound (Fe
3
S
2
) was synthesized at pressures greater than 14 gigapascals in the system Fe-FeS. The formation of Fe
3
S
2
changed the melting relations from a simple binary eutectic system to a binary system with an intermediate compound that melted incongruently. The eutectic temperature in the system at 14 gigapascals was about 400°C lower than that extrapolated from Usselman's data, implying that previous thermal models of Fe-rich planetary cores could overestimate core temperature. If it is found in a meteorite, the Fe
3
S
2
phase could also be used to infer the minimum size of a parent body.
First Genes Isolated From the Deadly 1918 Flu Virus
Authors: Pennisi Elizabeth
Published: July 2002

The great flu pandemic of 1918 rates as one of history's greatest killers, causing as many as 40 million deaths worldwide. Now for the first time, researchers have gotten a look at some of the genes from the virus at fault. In work described on page
1793
, they have used polymerase chain reaction techniques to amplify and sequence segments of five viral genes obtained from the preserved lung tissues of a U.S. Army private who died in the epidemic.
Plasma Physics Gets a Home
Authors: Glanz James
Published: July 2002

Plasma scientists have rushed to take advantage of a new $13 million federal program aimed at generating more basic knowledge about these ionized gases. Jointly sponsored by the Department of Energy and the National Science Foundation, the program aims to reverse a decades-long pattern of viewing plasma science as a large collection of applications, from fusion energy to plasma processing of semiconductors, and revitalize its scientific underpinnings.
Gravity Waves in Jupiter's Thermosphere
Authors: Young Leslie A. , Yelle Roger V. , Young Richard , Seiff Alvin , Kirk Donn B.
Published: July 2002

The Atmosphere Structure Instrument on the Galileo probe detected wavelike temperature fluctuations superimposed on a 700-kelvin temperature increase in Jupiter's thermosphere. These fluctuations are consistent with gravity waves that are viscously damped in the thermosphere. Moreover, heating by these waves can explain the temperature increase measured by the probe. This heating mechanism should be applicable to the thermospheres of the other giant planets and may help solve the long-standing question of the source of their high thermospheric temperatures.
Tritium Supply: Test Reactor Touted for Bomb Fuel
Authors: Lawler Andrew
Published: July 2002

RICHLAND, WASHINGTON
--The need to replenish constantly the nation's dwindling supply of tritium, an essential component of nuclear weapons, has caused Energy Department officials to study the feasibility of such multibillion-dollar solutions as a new reactor or a proton accelerator at its Savannah River facility in South Carolina. Now a third, far less expensive, idea has come to the fore--reviving a mothballed reactor at the Pacific Northwest National Laboratory in Washington state.
Particulate Matter: Getting a Handle on Air Pollution's Tiny Killers
Authors: Kaiser Jocelyn
Published: July 2002

Mention particulate pollution, and most people think of soot from smokestacks and diesel buses. But another source of particles--which are linked to respiratory-disease deaths in many cities--is just as important: gases from evaporated gasoline, solvents in paints, and other sources that condense onto bits of dust. Scientists have been hard pressed to figure out how these particles form and interact. But now, on
page 96
, a team of researchers describes a mathematical model that predicts how these gases are transformed into particles. The model should help the U.S. Environmental Protection Agency--which is planning to issue its first fine-particle standards this summer--figure out how to reduce levels of these tiny killers.
Physics: New Proof Hides Cosmic Embarrassment
Authors: Glanz James
Published: July 2002

Stephen Hawking is betting his shirt again. Earlier this year, the Cambridge University astrophysicist conceded one wager about the hypothetical ruptures in the laws of nature called singularities. But this time, according to a new theorem to be published in the
Annals of Mathematics
, Hawking has a better chance of winning.
Coreceptors--Implications for HIV Pathogenesis and Therapy
Authors: Moore John P.
Published: July 2002

Last year, the second of the two receptors that HIV uses to enter and infect human cells was identified. In his Perspective, Moore discusses the resulting revolution in thought about how these coreceptor molecules can influence the progress of AIDS and what their existence means for future therapies.
Programs in Physics
Authors: Fine Arthur
Published: July 2002

Conceptual Developments of 20th Century Field Theories.
TIAN YU CAO. Cambridge University Press, New York, 1996. xx, 433 pp. $59.95 or £45. ISBN 0-521-43178-6.
Pathways to Macroscale Order in Nanostructured Block Copolymers
Authors: Chen Zhong-Ren , Kornfield Julia A. , Smith Steven D. , Grothaus Jeffrey T. , Satkowski Michael M.
Published: July 2002

Polymeric materials undergo dramatic changes in orientational order in response to dynamic processes, such as flow. Their rich cascade of dynamics presents opportunities to create and combine distinct alignments of polymeric nanostructures through processing. In situ rheo-optical measurements complemented by ex situ x-ray scattering reveal the physics of three different trajectories to macroscopic alignment of lamellar diblock copolymers during oscillatory shearing. At the highest frequencies, symmetry arguments explain the transient development of a bimodal texture en route to the alignment of layers parallel to the planes of shear. At lower frequencies, larger-scale relaxations introduce rearrangements out of the deformation plane that permit the formation of lamellae perpendicular to the shear plane. These explain the change in the character of the pathway to parallel alignment and the emergence of perpendicular alignment as the frequency decreases.
Marvels on Display
Authors: Rhees David
Published: July 2002

Exhibiting Electricity.
K. G. BEAUCHAMP. Institution of Electrical Engineers, Stevenage, Herts, U.K., 1997 (U.S. distributor, IEE/INSPEC, Piscataway, NJ). xiv, 338 pp., illus. $85 or £45. ISBN 0-85296-895-7. IEE History of Technology, 21.
Immunological Origins of Binding and Catalysis in a Diels-Alderase Antibody
Authors: Romesberg Floyd E. , Spiller Ben , Schultz Peter G. , Stevens Raymond C.
Published: July 2002

The three-dimensional structure of an antibody (39-A11) that catalyzes a Diels-Alder reaction has been determined. The structure suggests that the antibody catalyzes this pericyclic reaction through a combination of packing and hydrogen-bonding interactions that control the relative geometries of the bound substrates and electronic distribution in the dienophile. A single somatic mutation, serine-91 of the light chain to valine, is largely responsible for the increase in affinity and catalytic activity of the affinity-matured antibody. Structural and functional studies of the germ-line precursor suggest that 39-A11 and related antibodies derive from a family of germ-line genes that have been selected throughout evolution for the ability of the encoded proteins to form a polyspecific combining site. Germ line–encoded antibodies of this type, which can rapidly evolve into high-affinity receptors for a broad range of structures, may help to expand the binding potential associated with the structural diversity of the primary antibody repertoire.
Knowledge from the Flies
Authors: Eanes Walter F.
Published: July 2002

Progress and Prospects in Evolutionary Biology:
The
Drosophila
Model. JEFFREY R. POWELL. Oxford University Press, New York, 1997. xiv, 562 pp., illus. $70. ISBN 0-19-507-691-5.
The Productivity Payoff of Computers
Authors: Bakos Yannis
Published: July 2002

The Computer Revolution
An Economic Perspective. by Daniel E. Sichel. Brookings Institution Press, Washington, DC, 1997. 164 pp. $38.95. ISBN 0-8157-7896-1.
Los Alamos Stories
Authors: Gusterson Hugh
Published: July 2002

Secret Mesa:
Inside Los Alamos National Laboratory. by Jo Ann Shroyer. Wiley, New York, 1997. 240 pp. $24.95. ISBN 0-471-04063-0.
Boundaries in Blood
Authors: Truman John T.
Published: July 2002

Drawing Blood
Technology and Disease Identity in Twentieth-Century America. Keith Wailoo. Johns Hopkins University Press, Baltimore, 1997. 304 pp. $39.95. ISBN 0-8018-5474-1.
A Broad Look at Future Worlds
Authors: Folke Carl
Published: July 2002

Which World? Scenarios for the 21st Century
.
By Allen Hammond
. Island Press, Washington, DC, 1998. 320 pp. $24.95. ISBN 1-55963-575-4.

Rather than try to predict the future, Hammond presents three scenarios for humanity in the coming century and explores their implications. He hopes to stimulate further thought and action, so that we can shape a sustainable world.
An Uneasy Marriage
Authors: McCallum Bruce
Published: July 2002

Origin 5.0
.
Microcal Software Inc.
. Northampton, MA. $595; $200, upgrades Phone: 800-969-7720.
http://www.microcal.com
.

In his New Media review, McCallum evaluates the newest release of Origin, version 5.0. This software integrates spreadsheet features of Excel and the graphics presentation features of PowerPoint, with mixed results.
Inhibition of Xenoreactive Natural Antibody Production by Retroviral Gene Therapy
Authors: Bracy Jennifer L. , Sachs David H. , Iacomini John
Published: July 2002

The major barrier to transplantation across discordant species, such as from pig to human, is rejection mediated by xenoreactive natural antibodies (XNA) that bind the carbohydrate epitope Galα1-3Galβ1-4GlcNAc-R (αGal) on donor tissues. This epitope is synthesized by the enzyme glucosyltransferase uridine 5′-diphosphate galactose:β-
d
-galactosyl-1,4-
N
-acetyl-
d
-glucosaminide α(1-3)galactosyltransferase (E.C. 2.4.1.151), or simply αGT. When a functional αGT gene was introduced by retroviral gene transfer into bone marrow cells, αGal XNA production in a murine model ceased. Thus, genetic engineering of bone marrow may overcome humoral rejection of discordant xenografts and may be useful for inducing B cell tolerance.
The Formation of Substellar Objects Induced by the Collision of Protostellar Disks
Authors: Lin D. N. C. , Laughlin G. , Bodenheimer P. , Róz˙yczka M.
Published: July 2002

Simulations of a close encounter between two protostars, each surrounded by a relatively massive disk, resulted in the ejection of some of the disk material into a tidal tail. A portion of the tail condensed into an object with a mass in the range of 5 to 10 jovian masses. This mechanism may explain the existence of the single objects of substellar mass that have recently been discovered.
Astrophysics on the GRAPE Family of Special-Purpose Computers
Authors: Hut Piet , Makino Jun
Published: July 2002

The GRAPE-4, the world's fastest computer in 1995–1997, has produced some major scientific results through a wide diversity of large-scale simulations in astrophysics. Applications have included planetary formation, the evolution of star clusters and galactic nuclei, and the formation of galaxies and clusters of galaxies.
A Hodgepodge of Controversies
Authors: Anderson Philip W.
Published: July 2002

Physicists in Conflict
. Neil A. Porter. Institute of Physics Publishing, Bristol, UK, 1998. 291 pp. $39.50, £25. ISBN 0-7503-0509-6.

Porter has written a collection of often disappointing accounts on a variety of conflicts: premodern clashes with religion, simple scientific blunders, political difficulties faced by scientists advising governments, and controversies within various fields of modern physics.
Direct Evidence for R
−
Rotons Having Antiparallel Momentum and Velocity
Authors: Tucker M. A. H. , Wyatt A. F. G.
Published: July 2002

Experimental evidence is presented that shows that the momentum of a R
−
roton (a particle-like excitation in liquid helium-4) is antiparallel to its velocity. Although this is anticipated from the negative slope of the dispersion curve for these excitations, it has only been possible to test since the development of a source of ballistic R
−
rotons. The backward refraction of the quantum evaporation process, which is the signature of antiparallel momentum and velocity, is observed.
Spectroscopic Limits on the Distance and Energy Release of GRB 990123
Authors: Andersen Michael I. , Castro-Tirado Alberto J. , Hjorth Jens , Møller Palle , Pedersen Holger , Caon Nicola , Cairós Luz Marina , Korhonen Heidi , Osorio Marı́a Rosa Zapatero , Pérez Enrique , Frontera Filippo
Published: July 2002

An optical spectrum of the afterglow from the unusually bright gamma-ray burst GRB 990123 obtained on 24.25 January 1999 universal time showed an absorption system at a redshift of
z
= 1.600. The absence of a hydrogen Lyman α forest sets an upper limit of
z
< 2.17, whereas ultraviolet photometry indicates an upper limit of
z
< 2.05. The probability of intersecting an absorption system as strong as the one observed along a random line of sight out to this
z
is at most a few percent, implying that GRB 990123 was probably at
z
= 1.600. Currently favored cosmological parameters imply that an isotropic energy release equivalent to the rest mass of 1.8 neutron stars (4.5 × 10
54
erg) was emitted in gamma rays. Nonisotropic emission, such as intrinsic beaming, may resolve this energy problem.
Crystal Structure of the Human Papillomavirus Type 18 E2 Activation Domain
Authors: Harris Seth F. , Botchan Michael R.
Published: July 2002

The papillomavirus E2 protein regulates viral transcription and DNA replication through interactions with cellular and viral proteins. The amino-terminal activation domain, which represents a protein class whose structural themes are poorly understood, contains key residues that mediate these functional contacts. The crystal structure of a protease-resistant core of the human papillomavirus type 18 E2 activation domain reveals a novel fold creating a cashew-shaped form with a glutamine-rich α helix packed against a β-sheet framework. The protein surface shows extensive overlap of determinants for replication and transcription. The structure broadens the concept of activators to include proteins with potentially malleable, but certainly ordered, structures.
Roles of PLC-β2 and -β3 and PI3Kγ in Chemoattractant-Mediated Signal Transduction
Authors: Li Zhong , Jiang Huiping , Xie Wei , Zhang Zuchuan , Smrcka Alan V. , Wu Dianqing
Published: July 2002

The roles of phosphoinositide 3-kinase (PI3K) and phospholipase C (PLC) in chemoattractant-elicited responses were studied in mice lacking these key enzymes. PI3Kγ was required for chemoattractant-induced production of phosphatidylinositol 3,4,5-trisphosphate [PtdIns (3,4,5)P
3
] and has an important role in chemoattractant-induced superoxide production and chemotaxis in mouse neutrophils and in production of T cell–independent antigen-specific antibodies composed of the immunoglobulin λ light chain (TI-Igλ
L
). The study of the mice lacking PLC-β2 and -β3 revealed that the PLC pathways have an important role in chemoattractant-mediated production of superoxide and regulation of protein kinases, but not chemotaxis. The PLC pathways also appear to inhibit the chemotactic activity induced by certain chemoattractants and to suppress TI-Igλ
L
production.
Three-Layered Atmospheric Structure in Accretion Disks Around Stellar-Mass Black Holes
Authors: Zhang S. N. , Cui Wei , Chen Wan , Yao Yangsen , Zhang Xiaoling , Sun Xuejun , Wu Xue-Bing , Xu Haiguang
Published: July 2002

Modeling of the x-ray spectra of the Galactic superluminal jet sources GRS 1915+105 and GRO J1655-40 reveals a three-layered atmospheric structure in the inner region of their accretion disks. Above the cold and optically thick disk with a temperature of 0.2 to 0.5 kiloelectron volts, there is a warm layer with a temperature of 1.0 to 1.5 kiloelectron volts and an optical depth around 10. Sometimes there is also a much hotter, optically thin corona above the warm layer, with a temperature of 100 kiloelectron volts or higher and an optical depth around unity. The structural similarity between the accretion disks and the solar atmosphere suggests that similar physical processes may be operating in these different systems.
A BAC-Based Physical Map of the Major Autosomes of
Drosophila melanogaster
Authors: Hoskins Roger A. , Nelson Catherine R. , Berman Benjamin P. , Laverty Todd R. , George Reed A. , Ciesiolka Lisa , Naeemuddin Mohammed , Arenson Andrew D. , Durbin James , David Robert G. , Tabor Paul E. , Bailey Michael R. , DeShazo Denise R. , Catanese Joseph , Mammoser †‡ Aaron , Osoegawa Kazutoyo , de † Pieter J. , Jong  , Celniker †‡ Susan E. , Gibbs Richard A. , Rubin Gerald M. , Scherer Steven E.
Published: July 2002

We constructed a bacterial artificial chromosome (BAC)–based physical map of chromosomes
2
and
3
of
Drosophila melanogaster
, which constitute 81% of the genome. Sequence tagged site (STS) content, restriction fingerprinting, and polytene chromosome in situ hybridization approaches were integrated to produce a map spanning the euchromatin. Three of five remaining gaps are in repeat-rich regions near the centromeres. A tiling path of clones spanning this map and STS maps of chromosomes
X
and
4
was sequenced to low coverage; the maps and tiling path sequence were used to support and verify the whole-genome sequence assembly, and tiling path BACs were used as templates in sequence finishing.