bluuebunny/crossref_metadata_2025 huggingface dataset:
Compensatory

ahp

C Gene Expression in Isoniazid-Resistant

Mycobacterium tuberculosis
Authors: Sherman David R. , Mdluli Khisimuzi , Hickey Mark J. , Arain Taraq M. , Morris Sheldon L. , Barry Clifton E. , Stover C. Kendall
Published: October 2006

Mutations that eliminate KatG catalase-peroxidase activity prevent activation of isoniazid and are a major mechanism of resistance to this principal drug for the treatment of
Mycobacterium tuberculosis
infections. However, the loss of KatG activity in clinical isolates seemed paradoxical because KatG is considered an important factor for the survival of the organism. Expression of either KatG or the recently identified alkyl hydroperoxidase AhpC was sufficient to protect bacilli against the toxic effects of organic peroxides. To survive during infection, isoniazid-resistant KatG mutants have apparently compensated for the loss of KatG catalase-peroxidase activity by a second mutation, resulting in hyperexpression of AhpC.
Arrested DNA Replication in

Xenopus

and Release by

Escherichia coli

Mutagenesis Proteins
Authors: Oda Naoko , Levin Joshua D. , Spoonde Alexander Y. , Frank Ekaterina G. , Levine Arthur S. , Woodgate Roger , Ackerman Eric J.
Published: October 2006

Xenopus
oocytes and oocyte nuclear extracts repair ultraviolet photoproducts on double-stranded (ds) DNA and replicate single-stranded (ss) to ds DNA. M13 ss DNA molecules containing cyclobutane pyrimidine dimers were maintained but not replicated in
Xenopus
oocytes, yet were replicated in progesterone-matured oocytes. The replication arrest functioned only in cis. The replication arrest was alleviated by injection into oocytes of messenger RNAs encoding the prokaryotic mutagenesis proteins UmuD′C or MucA′B. These results may help explain how cells stabilize repair or replication events on DNA with unrepairable lesions.
Goldin Drops Plan for New Institutes
Authors: Lawler Andrew
Published: October 2006

NASA has scrapped an ambitious plan to create a half-dozen nonprofit science institutes after failing to win White House support for the administrative and legislative changes required to get them up and running. The decision will force NASA Administrator Dan Goldin to find other ways to revitalize research at the agency's dozen centers and strengthen agency ties with academia.
Genes Seen Turning Imaginal Fly Eyes Into Reality
Authors: Roush Wade
Published: October 2006

Nashville, Tennessee—Deep within the larvae of most flies, beetles, moths, and butterflies lie quiescent but power-packed clusters of undifferentiated cells known as imaginal discs. In a process that researchers would dearly love to understand, the discs suddenly explode into life during metamorphosis: While the rest of the larva withers, they generate all the specialized cells that make up the adult insect's body. Now, after gazing deeply into developing fly eyes, researchers have gotten a better look at genes that make one imaginal structure real. At the national meeting of the Society for Developmental Biology here, scientists reported on four genes that help sweep a feature called the “morphogenetic furrow” across the eye imaginal discs of the fruit fly
Drosophila melanogaster
, transforming featureless cells into photoreceptors.
The Rebirth of Robert Gallo
Authors: Cohen Jon
Published: October 2006

Baltimore—Robert Gallo recently ended a 30-year stint at the U.S. National Cancer Institute, where his lab first published convincing evidence in 1984 that HIV causes AIDS, to run a brand-new institute here. Known as the Institute of Human Virology, its launch, combined with a recent landmark paper Gallo co-authored, provides ample evidence that at least some old guard researchers in the AIDS community remain a force to be reckoned with.
Induction of Bystander T Cell Proliferation by Viruses and Type I Interferon in Vivo
Authors: Tough David F. , Borrow Persephone , Sprent Jonathan
Published: October 2006

T cell proliferation in vivo is presumed to reflect a T cell receptor (TCR)-mediated polyclonal response directed to various environmental antigens. However, the massive proliferation of T cells seen in viral infections is suggestive of a bystander reaction driven by cytokines instead of the TCR. In mice, T cell proliferation in viral infections preferentially affected the CD44
hi
subset of CD8
+
cells and was mimicked by injection of polyinosinic-polycytidylic acid [poly(I:C)], an inducer of type I interferon (IFN I), and also by purified IFN I; such proliferation was not associated with up-regulation of CD69 or CD25 expression, which implies that TCR signaling was not involved. IFN I [poly(I:C)]-stimulated CD8
+
cells survived for prolonged periods in vivo and displayed the same phenotype as did long-lived antigen-specific CD8
+
cells. IFN I also potentiated the clonal expansion and survival of CD8
+
cells responding to specific antigen. Production of IFN I may thus play an important role in the generation and maintenance of specific memory.
Evidence for Physical and Functional Association Between EMB-5 and LIN-12 in

Caenorhabditis elegans
Authors: Albert Hubbard E. Jane , Dong Qu , Greenwald Iva
Published: October 2006

The
Caenorhabditis elegans
LIN-12 and GLP-1 proteins are members of the LIN-12/Notch family of receptors for intercellular signals that specify cell fate. Evidence presented here suggests that the intracellular domains of LIN-12 and GLP-1 interact with the
C. elegans
EMB-5 protein and that the
emb-5
gene functions in the same pathway as the
lin-12
and
glp-1
genes. EMB-5 is similar in sequence to a yeast protein that controls chromatin structure. Hence, a direct consequence of LIN-12 or GLP-1 activation may be an alteration of chromatin structure that produces changes in transcriptional activity.
Selling the Immune System Short
Authors: Cohen Jon
Published: October 2006

Despite much recent progress in understanding the AIDS virus, researchers are still unclear about how it causes the immunodeficiency that is the hallmark of the disease. But recent studies of the telomeres—the specialized stretches of genetic material at the ends of the chromosomes—are providing a clue. At least in one type of immune cell, the telomeres have turned out to be much shorter in AIDS patients than in healthy age-matched controls. Because telomeres are thought to shorten every time a cell divides, this finding suggests that the virus is essentially wearing out the immune system as it struggles to overcome the infection.
Long Ago, a River Ran Through It
Authors: Wuethrich Bernice
Published: October 2006

Today the hills outside Amarillo, Texas, are dry, but 225 million years ago this region held the thunderous headwaters of a giant river. Research reported on
page 97
uses a new method—precise dating of crystals of the mineral zircon—to show that the ancient Chinle River once rushed 1500 kilometers from what is now Texas to Nevada. By tying the river's mouth to its source, the study offers an unusually detailed window into the Late Triassic geography of the supercontinent of Pangaea.
With Mirrors and Finesse, Labs Domesticate the X-ray Laser
Authors: Hellemans Alexander
Published: October 2006

The first x-ray lasers, developed in the 1980s, were energized by nuclear explosions or jolts of light from giant glass lasers built for fusion experiments. But at a meeting 3 weeks ago in Lund, Sweden, investigators reported how those ungainly devices are now giving birth to bench-top x-ray lasers—practical tools for studying the dynamics of chemical reactions and the intricacies of living cells. To shrink their devices, investigators are substituting electric discharges and lower powered optical lasers for the brute-force pumping techniques of the first x-ray lasers. And they are boosting efficiency by reflecting the x-rays back and forth through the laser medium to extract more of its energy.
Chromosomes Yield New Clue to Pairing in Meiosis
Authors: Marx Jean
Published: October 2006

Production of normal male and female gametes by meiosis requires that chromosome partners, one from the individual's mother and its counterpart from his or her father, find each other and pair up before segregating into the two daughter cells in the first stage of meiosis. Exactly how this is accomplished is unclear, but new work, some of which is published in this issue (
p. 118
), should help clarify the mystery for at least one type of chromosome pairing and segregation. The results suggest that the chromosome partners are brought together by their heterochromatin, a result that also helps provide a function for this otherwise enigmatic, repetitive-sequence-laden genetic material.
Colossal Magnetoresistance Without Mn
3+
/Mn
4+
Double Exchange in the Stoichiometric Pyrochlore Tl
2
Mn
2
O
7
Authors: Subramanian M. A. , Toby B. H. , Ramirez A. P. , Marshall W. J. , Sleight A. W. , Kwei G. H.
Published: October 2006

Structural analysis from powder neutron and single-crystal x-ray diffraction data for a sample of the Tl
2
Mn
2
O
7
pyrochlore, which exhibits colossal magnetoresistance (CMR), shows no deviations from ideal stoichiometry. This analysis gives an Mn-O distance of 1.90 angstroms, which is significantly shorter than the Mn-O distances (1.94 to 2.00 angstroms) observed in phases based on LaMnO
3
perovskites that exhibit CMR. Both results in Tl
2
Mn
2
O
7
indicate oxidation states very close to Tl
3+
2
Mn
4+
2
O
7
. Thus, Tl
2
Mn
2
O
7
has neither mixed valence for a double-exchange magnetic interaction nor a Jahn-Teller cation such as Mn
3+
, both of which were thought to have an important function in CMR materials. An alternate mechanism for CMR in Tl
2
Mn
2
O
7
based on magnetic ordering driven by superexchange and strong spin-fluctuation scattering above the Curie temperature is proposed here.
Two Calorimetrically Distinct States of Liquid Water Below 150 Kelvin
Authors: Johari G. P. , Hallbrucker Andreas , Mayer Erwin
Published: October 2006

Vapor-deposited amorphous solid and hyperquenched glassy water were found to irreversibly transform, on compression at 77 kelvin, to a high-density amorphous solid. On heating at atmospheric pressure, this solid became viscous water (water B), with a reversible glass-liquid transition onset at 129 ± 2 kelvin. A different form of viscous water (water A) was formed by heating the uncompressed vapor-deposited amorphous solid and hyperquenched liquid water. On thermal cycling up to 148 kelvin, water B remained kinetically and thermodynamically distinct from water A. The occurrence of these two states, which do not interconvert, helps explain both the configurational relaxation of water and stress-induced amorphization.
The Decline of German Universities
Authors: Kahn Patricia
Published: October 2006

Bonn—The state of Germany's universities has suddenly become big news. They are underfunded and overcrowded; curricula are poorly organized; years of stagnant budgets has left them with decaying buildings and equipment; and the prospect of yet more draconian cuts means that the best staff and students are going elsewhere. Most believe the blame lies with the universities' own cumbersome bureaucracies and overbearing local government regulation which stifles reform. But this year there are signs of movement: Faculty and students have joined in mass demonstrations in Berlin and Leipzig against budget cuts, and some German states are starting the long road to reform, giving universities more autonomy, but demanding more quality too.
Panel Backs Joint Bion Mission
Authors: Lawler Andrew
Published: October 2006

An independent task force has recommended that NASA continue to participate in a space life sciences program with Russia that has drawn fire from animal-rights activists and some members of Congress. The panel praised the quality of the research and dismissed accusations that the effort mistreats rhesus monkeys and is of dubious scientific value. At the same time, it suggested that NASA look at the ethical issues raised by the use of animals in all its life sciences research before participating in a second flight.
Earmark for New Ship Puts Academics Over Pork Barrel
Authors: Mervis Jeffrey
Published: October 2006

A Senate proposal to give the Navy $45 million to build a replacement research ship for the University of Hawaii is producing a squall in the nation's leading oceanographic institutions. While oceanographers are grateful for congressional support for their field, many complain that the earmark undermines the long-range planning process based on peer review and consensus. And for some institutions the issue may turn out to be more than a matter of principle: The Navy, to hold down its costs after the new ship comes on line, could decide to retire one or more of its four other ships now being operated by academic institutions.
Evolutionary and Systematic Biologists Converge
Authors: Pennisi Elizabeth
Published: October 2006

St. Louis—For its 50th anniversary, the Society for the Study of Evolution returned here, where the group began, meeting jointly with the Society of Systematic Biologists from 19 to 23 June to further the evolving symbiotic relationship between these two disciplines. Among the talks was a plea to do away with the Linnaean system of biological classification, and a description of coevolution of closely related species of squid and luminescent bacteria that inhabit the creatures' light organs.
If a Tree Falls in the Forest…
Authors: Keller M. , Clark D. A. , Clark D. B. , Weitz A. M. , Veldkamp E.
Published: October 2006

Knowledge of the amount of carbon in the environment, especially in the form of carbon dioxide, is important for understanding global climate change. Old-growth forests in particular have been thought to be steady-state systems in which carbon uptake is balanced by carbon emission. In their Perspective, Keller
et al
. discuss a recent article by Grace
et al
. in which this assumption is challenged.
Rho Return: Its Targets in Focal Adhesions
Authors: Bussey Howard
Published: October 2006

Rho, a small molecular weight guanosine triphosphate binding protein, is a morphogenetic coordinator in yeast and mammalian cells. A paper in this week's issue by Kimura
et al
. (
p. 245
) reveals the biochemical details of how Rho activates myosin in stress fibers. In his Perspective, Bussey points out the similarities of the new information to morphogenetic systems in yeast.
Compression of Ice to 210 Gigapascals: Infrared Evidence for a Symmetric Hydrogen-Bonded Phase
Authors: Goncharov A. F. , Struzhkin V. V. , Somayazulu M. S. , Hemley R. J. , Mao H. K.
Published: October 2006

Protonated and deuterated ices (H
2
O and D
2
O) compressed to a maximum pressure of 210 gigapascals at 85 to 300 kelvin exhibit a phase transition at 60 gigapascals in H
2
O ice (70 gigapascals in D
2
O ice) on the basis of their infrared reflectance spectra determined with synchrotron radiation. The transition is characterized by soft-mode behavior of the
ν
3
O-H or O-D stretch below the transition, followed by a hardening (positive pressure shift) above it. This behavior is interpreted as the transformation of ice phase VII to a structure with symmetric hydrogen bonds. The spectroscopic features of the phase persisted to the maximum pressures (210 gigapascals) of the measurements, although changes in vibrational mode coupling were observed at 150 to 160 gigapascals.
Making DNA Add
Authors: Guarnieri Frank , Fliss Makiko , Bancroft Carter
Published: October 2006

Recent studies have demonstrated the feasibility of using DNA-based experiments to compute solutions to combinatorial problems. However, a prerequisite for designing a computer useful in a wide range of applications is the ability to perform mathematical calculations. The development of a DNA-based algorithm for addition is presented. The DNA representation of two nonnegative binary numbers is presented in a form permitting a chain of primer extension reactions to carry out the addition operation. To demonstrate the feasibility of this algorithm, a simple example was executed biochemically.
Congress Targets Fusion, Favors NIH
Authors: Lawler Andrew
Published: October 2006

Congress delivered a double punch to the U.S. fusion program last week when House and Senate panels voted separately to chop its budget well below the amount researchers agree is necessary to keep even a modest effort on track. Biomedical research fared much better: The House approved a 6.9% increase for the National Institutes of Health (NIH); the Senate is likely to follow suit with a smaller boost. These actions were part of a flurry of budget activity as Congress raced to clear as much legislation as possible before the August recess and the fall election campaigns.
Receptor for Vital Protein Finally Found
Authors: Roush Wade
Published: October 2006

Biologists, like wiretappers eavesdropping on clandestine molecular conversations, have been trying to trace protein signals as they travel from one cell to another and then to the recipient's genes. But some of the connections have been hard to pin down, none more so than the “Wnt” proteins, which help trigger the growth of the cerebellum in mice and—in some cases—cancerous cell proliferation. Researchers just haven't been able to identify the receptor molecules on the cell surface that pick up a Wnt signal and relay it to the interior. Now, however, researchers have identified the receptor for one Wnt family member, the fruit fly protein Wingless. With it, they can get a clear look at the molecules that carry Wingless's signal to the nucleus and determine the exact genes that receive this signal.
Galileo Finds Mysterious Magnetic Field at Ganymede
Authors: Kerr Richard A.
Published: October 2006

Jupiter's largest moon, Ganymede, bears the scars of ancient volcanoes and lava flows, but the moon's era of turbulence was thought to be long over. Now new results from the Galileo spacecraft, which swung close by Ganymede on 27 June, show that the moon's calm, icy surface hides a hot and dynamic interior. Galileo found clear signs of a magnetic field, implying that the moon has a churning, molten core of metal.
Atmospheric Dynamics on the Outer Planets
Authors: Gierasch Peter J.
Published: October 2006

Flow patterns in the outer planets are complex and not well understood. In his Perspective, Gierasch comments on new results presented by Cho and Polvani in this issue (
p. 335
) in which a shallow-fluid dynamical model was used to simulate the atmospheric flows on Jupiter, Saturn, Neptune, and Uranus. Several features of the observed flows, including the behavior of the jets and eddies, are captured in the model.
Creationists Evolve New Strategy
Authors: Schmidt Karen
Published: October 2006

Durham, North Carolina—Creationists have evolved a new strategy to get their ideas taught in public schools: They propose to teach “scientific evidence against evolution,” an angle which buries the religious aspects of the debate. This tactic has sparked creationist measures at the state and local levels around the country and is prompting scientists to act as public defenders of evolution.
Pests Overwhelm
Bt
Cotton Crop
Authors: Kaiser Jocelyn
Published: October 2006

Thousands of acres of cotton bioengineered to make its own insecticide have fallen victim in the southern United States to cotton bollworms, one of three pests that the crops were supposed to kill. The result has heightened the fears of environmental activists that the insects will eventually develop resistance to the toxin, known as Bt, and that fear has revived calls for tougher federal biosafety regulations. The reasons behind the disappointing results—involving one of the first large-scale plantings of a transgenic crop—also serve as a reminder to researchers that Mother Nature still has a few tricks up her sleeve.
Teams Tackle Protein Prediction
Authors: Pennisi Elizabeth
Published: October 2006

Computer modelers have been trying for 30 years to predict the three-dimensional structures of proteins from their amino acid sequences. So far, they have had little success. But a novel competition, known as CASP2 (for second Critical Assessment of Techniques for Protein Structure Prediction) could spur the field along. Some 75 groups will pit their models head-to-head to see which do best at coming up with the actual structures of proteins that crystallographers and nuclear magnetic resonance spectroscopists will solve by the end of the year. When the results are discussed at a meeting in December, each group will be able to build on the successful features of their competitors' models, and the competition will become essentially a giant collaboration to crack the problem of protein structure prediction. More information on
CASP2
can be found on the Web.
‘Hot Jupiters’ Leave Theorists in the Cold
Authors: Schilling Govert
Published: October 2006

Capri, Italy—It has been just 10 months since a pair of Swiss astronomers first identified a planet orbiting a sunlike star other than our own, but the tally of so-called “exoplanets” has now passed the total of nine familiar planets of our solar system. That mark came earlier this month at the Fifth International Conference on Bioastronomy, where astronomers reported several new sightings, including the first evidence of another multiplanet system around a sunlike star. And with the total steadily growing, researchers are beginning to identify tentative groupings of planet types, one of which is completely unlike the planets in our solar system.
Flood of New Isotopes Offers Keys to Stellar Evolution
Authors: Normile Dennis
Published: October 2006

Omiya, Japan—A heavy-ion accelerator laboratory in Darmstadt, Germany, is renowned for giving researchers the tools needed to create the six heaviest elements on the periodic table. But the facility is also helping scientists to fill gaps, at an unprecedented rate, in another important atomic listing—a chart of unstable isotopes. The new knowledge, including the mass and lifetimes of those isotopes, is expected to help scientists hone theories about how supernova produce heavy elements and distribute them throughout the universe.
The Right Mix of Form and Function?
Authors: Kahn Patricia
Published: October 2006

Heidelberg—Last summer, Germany's science minister, Jürgen Rüttgers, made an announcement that many of the country's researchers thought they would never hear: The government would launch a national genome research program. Rüttgers's announcement posed a tough question: How should Germany enter a fast-moving field in which it lags far behind? Some argued that Germany should shoulder its share of high-cost mapping and sequencing efforts already being pursued by other countries, while others felt that Germany should instead concentrate on ways to get at the functions of the human genes being uncovered by those efforts. One year and many hard discussions later, with the first projects chosen, the outlines of the enterprise are emerging—although the debate on how to divide up the funds may not be over.
Chemical Shackles for Genes?
Authors: Pennisi Elizabeth
Published: October 2006

For years, researchers have thought that addition of a methyl group to the cell's DNA might be one of nature's ways of shackling the activity of genes that become unnecessary as development proceeds. Proving that has been difficult, however. But recent findings in both the plant
Arabidopsis
thaliana and in mice provide some of the best evidence yet for that idea. As reported on
page 654
, the work shows that genetic modifications that reduce methylation lead to developmental abnormalities.
Arabidopsis
development is prolonged so that the plants make more leaves than normal before flowering, and the flowers themselves are abnormal. Still unclear, however, is exactly how methylation alters gene expression and development.
Experiments Mimic Infant Universe in Superfluid Helium
Authors: Taubes Gary
Published: October 2006

Flasks of liquid helium have yielded evidence for one of cosmologists' more esoteric notions: that infinite stringlike fractures appeared in the fabric of space-time as the early universe began to cool and might have seeded the formation of the galaxies and larger scale structures we see today. Two international teams report that they have measured the rate at which strings form in the helium as it undergoes a phase transition between the normal and superfluid states—a transition thought to be analogous to ones that took place in the early universe. The results match theoretical predictions for what might have occurred in the early universe.
CO in the Early Universe Clouds Cosmologists' Views
Authors: Glanz James
Published: October 2006

Two groups of astronomers announced last week that they had detected the glow of a giant cloud of carbon monoxide (CO) in the far reaches of the universe, when it was just a billion years old. These heavy elements are generated only in the nuclear furnaces of stars, which can then explode and spew the material back into space. The detection thus suggests that the formation of galaxies—and the stars they contain—was well under way at that early date. The finding could conflict with the most widely accepted cosmological models, which predict that widespread galaxy formation didn't get under way until much later.
Shaking Out the Cause of Addiction
Authors: Hyman Steven E.
Published: October 2006

In a paper in this week's issue, Maldonado
et al
. (
p. 657
) report that mice lacking most of their normal complement of the transcription factor CREB exhibit attenuation of withdrawal symptoms, implicating this transcription factor in mediation of withdrawal effects. Hyman discusses these results in the context of the other biochemical changes that occur in the neurons of the locus ceruleus, a key brain area for withdrawal.
Impairment of Hippocampal Mossy Fiber LTD in Mice Lacking mGluR2
Authors: Yokoi Mineto , Kobayashi Katsunori , Manabe Toshiya , Takahashi Tomoyuki , Sakaguchi Isako , Katsuura Goro , Shigemoto Ryuichi , Ohishi Hitoshi , Nomura Sakashi , Nakamura Kenji , Nakao Kazuki , Katsuki Motoya , Nakanishi Shigetada
Published: October 2006

Subtype 2 of the metabotropic glutamate receptor (mGluR2) is expressed in the presynaptic elements of hippocampal mossy fiber-CA3 synapses. Knockout mice deficient in mGluR2 showed no histological changes and no alterations in basal synaptic transmission, paired-pulse facilitation, or tetanus-induced long-term potentiation (LTP) at the mossy fiber-CA3 synapses. Long-term depression (LTD) induced by low-frequency stimulation, however, was almost fully abolished. The mutant mice performed normally in water maze learning tasks. Thus, the presynaptic mGluR2 is essential for inducing LTD at the mossy fiber-CA3 synapses, but this hippocampal LTD does not seem to be required for spatial learning.
Presynaptic Long-Term Depression at the Hippocampal Mossy Fiber—CA3 Synapse
Authors: Kobayashi Katsunori , Manabe Toshiya , Takahashi Tomoyuki
Published: October 2006

Long-term potentiation (LTP) and long-term depression (LTD) of synaptic strength may underlie learning and memory in the brain. The induction of LTP occurs in postsynaptic cells in the hippocampal CA1 region but is presynaptic in CA3. LTD is also well characterized in CA1 but not in CA3. Low-frequency stimulation of mouse hippocampal slices caused homosynaptic LTD at the mossy fiber-CA3 synapse, which may be induced presynaptically by activation of metabotropic glutamate receptors. Thus, the efficacy of mossy fiber-CA3 synapses can be regulated bidirectionally, which may contribute to neuronal information processing.
U.S. Neutron Scientists Settle for Less
Authors: Lawler Andrew
Published: October 2006

Internal squabbling, reduced funding, and a lack of political support are forcing U.S. neutron researchers to play catch-up to Europe and Japan in their quest for new, cutting-edge facilities. The problem is compounded, say researchers, by a lack of respect for a field that is making important contributions to basic knowledge about the structure of matter and helping to develop new products with billion-dollar markets. “We're the Rodney Dangerfield of scientific facilities,” sighs Bill Appleton, associate director at Oak Ridge National Laboratory, which operates one of the countryd's three neutron-source reactors.
Construction Costs May Bite Into Science
Authors: Lawler Andrew
Published: October 2006

NASA space station officials are planning to divert money that has been set aside for scientific facilities to pay for engineering problems that have surfaced in the construction of the orbiting laboratory. The move likely would delay research programs planned for the station, which will be launched in pieces starting in November 1997. It also heightens the concerns of researchers already worried about the agency's commitment to science aboard the station. “Our cynicism is well-honed,” says Claude Canizares, the Massachusetts Institute of Technology astrophysicist who chairs the National Research Council's Space Studies Board.
Painting Pictures With Atom Waves
Authors: Glanz James
Published: October 2006

A Japanese team has come up with a striking demonstration of the wavelike nature of matter. Using optical principles to control the quantum-mechanical waves of neon atoms, the researchers coaxed the atoms to form a minute physical image. They passed the waves through a computer-generated hologram, an apparently meaningless pattern in a membrane that caused the atom waves to interfere and create an intelligible image—the letters NEC—on a detector.
Genes vs. Teams: Weighing Group Tactics in Evolution
Authors: Morell Virginia
Published: October 2006

Most biologists think of individual organisms as the main players in the evolutionary game. But some evolutionary biologists have argued that this view overlooks the struggles and strategies of “teams”—whether they be species, groups of cells, or groups of organisms. And although the idea of group selection was discredited more than 30 years ago, a growing number of researchers say that it deserves a fresh hearing. New models and data, they say, answer some of the criticisms originally aimed at group selection.
Cooperative DNA Binding and Sequence-Selective Recognition Conferred by the STAT Amino-Terminal Domain
Authors: Xu Xiang , Sun Ya-Lin , Hoey Timothy
Published: October 2006

STAT proteins (signal transducers and activators of transcription) activate distinct target genes despite having similar DNA binding preferences. The transcriptional specificity of STAT proteins was investigated on natural STAT binding sites near the interferon-gamma gene. These sites are arranged in multiple copies and required cooperative interactions for STAT binding. The conserved amino-terminal domain of STAT proteins was required for cooperative DNA binding, although this domain was not essential for dimerization or binding to a single site. Cooperative binding interactions enabled the STAT proteins to recognize variations of the consensus site. These sites can be specific for the different STAT proteins and may function to direct selective transcriptional activation.
Cardiovascular Regulation in Mice Lacking α
2
-Adrenergic Receptor Subtypes b and c
Authors: Link Richard E. , Desai Kavin , Hein Lutz , Stevens Mary E. , Chruscinski Andrzej , Bernstein Daniel , Barsh Gregory S. , Kobilka Brian K.
Published: October 2006

α
2
-Adrenergic receptors (α
2
ARs) are essential components of the neural circuitry regulating cardiovascular function. The role of specific α
2
AR subtypes (α
2a
, α
2b
, and α
2c
) was characterized with hemodynamic measurements obtained from strains of genetically engineered mice deficient in either α
2b
or α
2c
receptors. Stimulation of α
2b
receptors in vascular smooth muscle produced hypertension and counteracted the clinically beneficial hypotensive effect of stimulating α
2a
receptors in the central nervous system. There were no hemodynamic effects produced by disruption of the α
2c
subtype. These results provide evidence for the clinical efficacy of more subtype-selective α
2
AR drugs.
Attracting Funds and Hopes
Authors: Keoun Bradley
Published: October 2006

Tallahassee—This Florida Panhandle city is fast becoming the Mecca of condensed matter physics, thanks to the National High Magnetic Field Laboratory (NHMFL), which opened its doors on the campus of Florida State University (FSU) in 1993. the National Science Foundation stunned many scientists in 1990 when it picked FSU rather than the Massachusetts Institute of Technology, home of the famed Francis Bitter National Magnet Laboratory, to house the new lab. It's still too early to predict what NHMFL will achieve, but its staff recruitments, world-class magnets, and agenda suggest that it is already becoming an important player in areas ranging from high temperature superconductivity to biology.
Looking for Clues to the Mystery of Life on Earth
Authors: Balter Michael
Published: October 2006

Orléans, France
—Nearly 300 scientists, including three Nobel laureates, gathered here last month to grapple with the riddle of how DNA and RNA first came to exist and how they evolved into self-reproducing cells—questions that have gained new urgency with the hint that life in some form may also have evolved on Mars. Highlights of the meeting included new geological studies that may push back the date of the earliest life on Earth by 400 million years; new analyses of organic molecules from a meteorite which suggest that the phosphorus compounds essential to DNA and RNA may have come from space; and attempts to simulate early life in a test tube, which indicate that the first living molecules may have been RNA.
Evolution and Climate Variability
Authors: Potts Richard
Published: October 2006

According to natural selection theory, major adaptive change depends on consistency in the effects of Darwinian selection. In his Perspective, Potts argues that another force is at work: variability selection, in which certain organisms adapt to wide fluctuations in environmental conditions.
A New Receptor for Growth Hormone-Release Peptide
Authors: Conn Michael P. , Bowers Cyril Y.
Published: October 2006

For a decade or so, there have been hints of an alternative way to regulate growth hormone beyond growth hormone-releasing hormone and somatostatin. Now Howard
et al
., in this week's
Science
(
p. 974
), have confirmed this suspicion by cloning the receptor for this alternative pathway. In their Perspective, Conn and Bowers discuss the unusual route by which this receptor was cloned, through the use of “reverse pharmacology” in which a synthetic ligand for the receptor was made before the natural ligand (which still remains unidentified).
Cure of Short- and Long-Term Experimental Chagas' Disease Using D0870
Authors: Urbina Julio A. , Payares Gilberto , Molina Judith , Sanoja Cristina , Liendo Andreína , Lazardi Keyla , Piras Marta M. , Piras Romano , Perez Norma , Wincker Patrick , Ryley John F.
Published: October 2006

Chagas' disease, a protozoan infection by the kinetoplastid
Trypanosoma cruzi
, constitutes a major public health problem in Latin America. With the use of mouse models of both short- and long-term forms of the disease, the efficacy of D0870, a bis-triazole derivative, was tested. D0870 was able to prevent death and induced parasitological cure in 70 to 90 percent of animals, in both the short- and long-term disease. In contrast, currently used drugs such as nifurtimox or ketoconazole prolonged survival but did not induce significant curing effects. D0870 may be useful in the treatment of human long-term Chagas' disease, a condition that is currently incurable.
Salk: Under New Management
Authors: Cohen Jon
Published: October 2006

La Jolla, California—After several years of coasting along under acting directors, the Salk Institute for Biological Studies has a new leader: cell biologist Thomas Pollard. Pollard, who is moving his lab from Johns Hopkins University, faces some big challenges in raising the elite institution's relatively meager endowment and expanding its research base.
Getting Familiar With the Top Quark
Authors: Glanz James
Published: October 2006

Minneapolis—It was only last year that particle physicists confirmed the existence of the top quark, the heaviest building block of matter. Now they are seeing top quarks by the scores and getting an accurate fix on their mass, physicists reported here at a meeting of the American Physical Society's division of particle and fields. The refined top mass is providing a guidepost to a bigger prize: the still-unseen Higgs boson, a particle that would help explain the array of different masses seen in other elementary particles, one of the major unsolved mysteries of particle physics.
Rapid Variations in Atmospheric Methane Concentration During the Past 110,000 Years
Authors: Brook Edward J. , Sowers Todd , Orchardo Joe
Published: October 2006

A methane record from the GISP2 ice core reveals that millennial-scale variations in atmospheric methane concentration characterized much of the past 110,000 years. As previously observed in a shorter record from central Greenland, abrupt concentration shifts of about 50 to 300 parts per billion by volume were coeval with most of the interstadial warming events (better known as Dansgaard-Oeschger events) recorded in the GISP2 ice core throughout the last glacial period. The magnitude of the rapid concentration shifts varied on a longer time scale in a manner consistent with variations in Northern Hemisphere summer insolation, which suggests that insolation may have modulated the effects of interstadial climate change on the terrestrial biosphere.
Corticofugal Modulation of Time-Domain Processing of Biosonar Information in Bats
Authors: Yan Jun , Suga Nobuo
Published: October 2006

The Jamaican mustached bat has delay-tuned neurons in the inferior colliculus, medial geniculate body, and auditory cortex. The responses of these neurons to an echo are facilitated by a biosonar pulse emitted by the bat when the echo returns with a particular delay from a target located at a particular distance. Electrical stimulation of cortical delay-tuned neurons increases the delay-tuned responses of collicular neurons tuned to the same echo delay as the cortical neurons and decreases those of collicular neurons tuned to different echo delays. Cortical neurons improve information processing in the inferior colliculus by way of the corticocollicular projection.
Selective Activation of Calcium Permeability by Aspartate in Purkinje Cells
Authors: Yuzaki Michisuke , Forrest Douglas , Curran Tom , Connor John A.
Published: October 2006

Glutamate and aspartate are endogenous excitatory amino acid neurotransmitters widely distributed in the mammalian central nervous system. Aspartate was shown to induce a large membrane current sensitive to
N
-methyl-D-aspartate (NMDA) and non-NMDA receptor antagonists in Purkinje cells from mice lacking functional NMDA receptors (NR1
−/−
). This response was accompanied by high permeability to calcium. In contrast, no current was induced by aspartate in hippocampal neurons and cerebellar granule cells from NR1
−/−
mice. Several other glutamate receptor agonists failed to evoke this response. Thus, in Purkinje cells, aspartate activates a distinct response capable of contributing to synaptic plasticity through calcium permeability.
All Together for Quantum Computing
Authors: Taubes Gary
Published: October 2006

A consortium of researchers from Caltech, the Massachusetts Institute of Technology, and the University of Southern California has founded an institute for Quantum Information and Computing at Caltech to test the promise of quantum computers—hypothetical devices that would harness the ambivalence of quantum-mechanical states to compute faster than the fastest possible classical computer. Funded with a 5-year, $5 million grant from the Defense Advanced Research Projects Agency, the institute-without-walls unites researchers who will work on different pieces of the quantum-computing puzzle. Computers/Math
Drug's Link to Genes Reveals Estrogen's Many Sides
Authors: Pennisi Elizabeth
Published: October 2006

The hormone estrogen is both a villain and a savior, thought to contribute to the development of breast and uterine cancers but also to protect women against heart attacks and osteoporosis. Now a study of an estrogenlike drug, reported on
page 1222
, may help explain the hormone's contradictory personality and open the way to designing drugs that block only its unwanted effects—or mimic only its beneficial ones. The drug, called raloxifene, sends its signals to the genes by different pathways depending on the tissue it is acting on. The natural hormone may owe its many guises to a similar variety of pathways.
A Silicate Inclusion in Puente del Zacate, a IIIA Iron Meteorite
Authors: Olsen Edward J. , Davis Andrew M. , Clayton Robert N. , Mayeda Toshiko K. , Moore Carleton B. , Steele Ian M.
Published: October 2006

The IIIA and IIIB iron meteorites are considered to have formed in the cores of asteroids. A silicate inclusion within the IIIA meteorite Puente del Zacate consisting of olivine (Fa
4
), low-calcium pyroxene (Fs
6
Wo
1
), chromium diopside (Fs
3
Wo
47
), plagioclase (An
14
Or
4
), graphite, troilite, chromite, daubreelite, and iron metal resembles inclusions in IAB iron meteorites. The oxygen isotopic composition of the Puente del Zacate inclusion is like chromite and phosphate inclusions in other IIIA and IIIB irons. The Puente del Zacate inclusion may have been derived from the lower mantle of the IIIAB parent asteroid.
Threefold Electron Scattering on Graphite Observed with C
60
-Adsorbed STM Tips
Authors: Kelly K. F. , Sarkar D. , Hale G. D. , Oldenburg S. J. , Halas N. J.
Published: October 2006

The scanning tunneling microscope (STM) has been used to observe threefold symmetric electron scattering from point defects on a graphite surface. These theoretically predicted electronic perturbations could not be observed with a bare metal tip but could only be imaged when a fullerene (C
60
) molecule was adsorbed onto the tunneling region (apex) of an STM tip. Functionalizing an STM tip with an appropriate molecular adsorbate alters the density of states near the Fermi level of the tip and changes its imaging characteristics.
CRINKLY4: A TNFR-Like Receptor Kinase Involved in Maize Epidermal Differentiation
Authors: Becraft Philip W. , Stinard Philip S. , McCarty Donald R.
Published: October 2006

The maize
crinkly4
(
cr4
) mutation affects leaf epidermis differentiation such that cell size and morphology are altered, and surface functions are compromised, allowing graft-like fusions between organs. In the seed, loss of
cr4
inhibits aleurone formation in a pattern that reflects the normal progression of differentiation over the developing endosperm surface. The
cr4
gene was isolated by transposon tagging and found to encode a putative receptor kinase. The extracellular domain contains a cysteine-rich region similar to the ligand binding domain in mammalian tumor necrosis factor receptors (TNFRs) and seven copies of a previously unknown 39-amino acid repeat. The results suggest a role for
cr4
in a differentiation signal.
China's Campaign to Predict Quakes
Authors: Li Hui
Published: October 2006

Beijing—A vast, 30-year effort to monitor the earthquakes that regularly shake China has led to unprecedented—and controversial—success in predicting them. After decades of secrecy, the Chinese have recently begun opening up this program to the West, giving foreign scientists a closer look at an effort about which many have been highly skeptical. Chinese officials say that “the accumulation of experience”—including reliance on empirical analysis of a host of precursors—can be very useful in forecasting earthquakes so long as the underlying physical mechanisms remain poorly understood.
Starting Species With Third Parties and Sex Wars
Authors: Morell Virginia
Published: October 2006

How does evolution make new species without a geographic barrier to isolate populations and prevent them from exchanging genes? It has a whole bag of tricks for doing so, as a recent conference showed. There researchers described how such factors as bacterial agents, mimicry, changes in a single pigment gene or in the song of a bird, or the rapid evolution of a sperm surface protein can all trigger cascades of events leading to a new species, without any geographic barrier.
Labour Promises Key Role for Science
Authors: Williams Nigel
Published: October 2006

London—Statements from Britain's Labour Party are being taken seriously these days: With a lead of 15% in the public opinion polls and a general election due before next summer, today's pronouncements could become tomorrow's policies. Britain's scientific community is therefore paying close attention to a document Labour published last week laying out its science policy. It includes promises to bolster flagging morale among British researchers, elevate science in government decision-making, and scrap controversial reviews ofnational laboratories with a view to privatizing them.
The Next Lap in the Forecast Race
Authors: Kerr Richard A.
Published: October 2006

European and American researchers have been in a friendly competition over raw forecasting power for nearly 2 decades. The race is judged to be neck and neck now, but more powerful computers will soon give the Europeans the edge.
Linking Microbiology and Engineering
Authors: Potera Carol
Published: October 2006

For years biofilms were considered chiefly a practical problem, the domain of engineers worried about corrosion. Then in the 1980s, one charismatic engineer, the late William Characklis of Montana State University in Bozeman, learned microbiological techniques andbridged the gap between biology and engineering. Characklis's interdisciplinary legacy continues at the biofilm center he founded at Montana State.
Receptor Mutations Help Slow Disease Progression<
Authors: Cohen Jon
Published: October 2006

Population geneticist Stephen O'Brien of the National Cancer Institute and a large group of collaborators have amassed strong confirmatory evidence that people who have two mutant copies of the gene for a chemokine receptor known as CCR5 (also known as CKR5) are highly resistant to HIV infection. The findings, published on
page1856
, also indicate that people who do get infected with HIV, but have one mutant copy of the CCR5 gene, progress to AIDS more slowly than do people without the mutation.
How the Songbird Makes His Song
Authors: Pennisi Elizabeth
Published: October 2006

In human organizations, those at the top tend to set strategy, while leaving the details to their underlings. The same thing seems to happen in the brain—at least in the brain of the male zebra finch as it controls the bird's singing. On
page1871
of this issue, researchers report that the singing instructions are relayed down a hierarchy ofbrain regions, getting progressively more detailed as they go. The firing patterns of neurons in the higher brain centers apparently specify collections of notes, while the patterns at the lower level define the basic sounds—most likely, the notes themselves.
Politics Meets Technology in Next Collider
Authors: Hellemans Alexander
Published: October 2006

While the morale of high-energy physicists, particularly in the United States, was severely dented by the cancellation of the U.S. Superconducting Super Collider project in 1993, they did not dwell on that setback for long. Soon researchers were cooking up plans for an entirely new and truly international venture: the world's longest linear accelerator, or linac, which could stretch as far as 30 kilometers. And late last month, at the 18th International Linac Conference in Geneva, the Next Linear Collider took another step from pipe dream to reality, as five different physics groups unfurled blueprints for the machine.
Flux Lattice Melting
Authors: Bishop David J.
Published: October 2006

How superconducting materials respond to magnetic fields is intimately tied with how they behave in technological applications. In his Perspective, Bishop discusses recent work at the University of Leiden on a phenomenon called flux lattice melting. How these flux lattices behave can reveal information about how much current the superconductor can carry.