bluuebunny/crossref_metadata_2025 huggingface dataset:
Distinct Protein Targets for Signals Acting at the c-
fos
Serum Response Element
Authors: Graham Regina , Gilman Michael
Published: October 2006

The c-
fos
serum response element (SRE) is a primary nuclear target for intracellular signal transduction pathways triggered by growth factors. It is the target for both protein kinase C (PKC)-dependent and -independent signals. Function of the SRE requires binding of a cellular protein, termed serum response factor (SRF). A second protein, p62
TCF
, recognizes the SRE-SRF complex to form a ternary complex. A mutated SRE that bound SRF but failed to form the ternary complex selectively lost response to PKC activators, but retained response to PKC-independent signals. Thus, two different signaling pathways act through discrete nuclear targets at the SRE. At least one of these pathways functions by recruitment of a pathway-specific accessory factor (p62
TCF
). These results offer a molecular mechanism to account for the biological specificity of signals that appear to act through common DNA sequence elements.
Peripheral Selection of the T Cell Repertoire
Authors: Rocha Benedita , von Boehmer Harald
Published: October 2006

T lymphocytes undergo selection events not only in the thymus, but also after they leave the thymus and reside in the periphery. Peripheral selection was found to be dependent on T cell receptor (TCR)-ligand interactions but to differ from thymic selection with regard to specificity and mechanism. Unlike thymic selection, peripheral selection required binding of antigen to the TCR, and it induced expansion of T cell clones. Tolerance to self antigens that are restricted to the periphery occurred through the elimination of self-reactive T cells and by the clonal anergy, which was associated with down-regulation of the αβ TCR and CD8.
Diversity of G Proteins in Signal Transduction
Authors: Simon Melvin I. , Strathmann Michael P. , Gautam Narasimhan
Published: October 2006

The heterotrimeric guanine nucleotide-binding proteins (G proteins) act as switches that regulate information processing circuits connecting cell surface receptors to a variety of effectors. The G proteins are present in all eukaryotic cells, and they control metabolic, humoral, neural, and developmental functions. More than a hundred different kinds of receptors and many different effectors have been described. The G proteins that coordinate receptor-effector activity are derived from a large gene family. At present, the family is known to contain at least sixteen different genes that encode the alpha subunit of the heterotrimer, four that encode beta subunits, and multiple genes encoding gamma subunits. Specific transient interactions between these components generate the pathways that modulate cellular responses to complex chemical signals.
An Analog of Enkephalin Having Prolonged Opiate-Like Effects in Vivo
Authors: Walker J. Michael , Berntson Gary G. , Sandman Curt A. , Coy David H. , Schally Andrew V. , Kastin Abba J.
Published: October 2006

Intraventricular administration of the enkephalin analog, [D-Ala
2
]-Metenkephalin, induces profound and long-lasting analgesia, as well as other opiate-like behavioral effects in the rat. This analgesia was highly dose dependent, of much greater magnitude, and about 30 times longer lasting than that produced by the naturally occurring peptide, methionine-enkephalin. The behavioral effects of the [D-Ala
2
] analog could be completely reversed by the opiate antagonist, naloxone, suggesting that these effects were mediated by opiate receptors. Systemic administration of naloxone alone resulted in a significant increase in pain sensitivity. These findings support the view that endogenous opiate systems may play an important role in modulating pain sensitivity.
Visual Motion Commands for Pursuit Eye Movements in the Cerebellum
Authors: Krauzlis Richard J. , Lisberger Stephen G.
Published: October 2006

Eye movements that follow a target (pursuit eye movements) facilitate high acuity visual perception of moving targets by transforming visual motion inputs into motor commands that match eye motion to target motion. The performance of pursuit eye movements requires the cerebellar flocculus, which processes both visual motion and oculomotor signals. Electrophysiological recordings from floccular Purkinje cells have allowed the identification of their firing patterns during generation of the image velocity and image acceleration signals used for pursuit. Analysis with a method based on a behavioral model converted the time-varying spike trains of floccular Purkinje cells into a description of the firing rate contributed by three visual motion signals and one oculomotor input. The flocculus encodes all the signals needed to guide pursuit.
Role of the Generative Cell in Androgenesis in Henbane
Authors: Raghavan V.
Published: October 2006

When anthers of henbane containing uninucleate pollen grains were cultured, a large number of embryoids originated exclusively from the division of the generative cell. In a small proportion of pollen grains, both generative and vegetative cells contributed to embryoid formation. Embryogenesis by segmentation of the vegetative cell alone was rarely observed.
Hydrocarbons in Open Ocean Waters
Authors: Brown R. A. , Huffman H. L.
Published: October 2006

Nonvolatile hydrocarbons in Atlantic Ocean and nearby waters were found to contain aromatics at lower concentrations than would be expected if the source of the hydrocarbons were crude oil or petroleum refinery products. Hydrocarbons appear to persist in the water to varying degrees with the most persistent being the cycloparaffins, then the isoparaffins, and finally the aromatics.
Diamonds in an Upper Mantle Peridotite Nodule from Kimberlite in Southern Wyoming
Authors: McCallum M. E. , Eggler David H.
Published: October 2006

Diamonds in a serpentinized garnet peridotite nodule from a diatreme in southern Wyoming are the first known occurrence in an upper mantle peridotite xenolith from a kimberlite intrusion in North America as well as the second authenticated occurrence of diamonds from kimberlite pipes in North America. The nodule is believed to have come from a section of depleted (partially melted) lherzolite at a depth of 130 to 180 kilometers.
Dade County: The Politics of Managing Urban Growth
Authors: Carter Luther J.
Published: October 2006

This is one of several articles specially prepared for this issue of
Science
in recognition of Habitat: The United Nations Conference on Human Settlements now taking place in Vancouver.
Restriction Endonuclease Analysis of Mitochondrial DNA from Normal and Texas Cytoplasmic Male-Sterile Maize
Authors: Levings C. S. , Pring D. R.
Published: October 2006

Mitochondrial DNA from normal and cytoplasmic male-sterile maize was digested with restriction endonucleases RI from
Escherichia coli
or dIII from
Hemophilus influenzae
. Electrophoresis of resulting fragments revealed distinctions between the two cytoplasmic types. These distinctions suggest that factors responsible for cytoplasmic male sterility are located in the mitochondrial DNA, and that the mitochondrial genome is not inherited paternally.
Total Synthesis Benzene and Its Derivatives as Major Gasoline Extenders
Authors: Tamers M. A.
Published: October 2006

Synthesized benzene and simple alkylated derivatives are proposed as nonpetrochemical gasoline components. Feasible raw materials include coal, coke, charcoal, and carbonaceous wastes. The basic synthesis consists of the formation of lithium carbide by reaction of the metal with carbon, hydrolysis of the carbide to acetylene, cyclization of acetylene to benzene, and regeneration of lithium metal. Total synthesis benzene is substantially different from other synthetic hydrocarbon fuels in that its hydrogen content is obtained from water so that hydrogen gas is not needed as a major reactant.
Prehistoric Hawaiian Fishponds
Authors: Kikuchi William K.
Published: October 2006

One of the important technological concepts that was developed in the Hawaiian Islands is that of the fishpond. From the 14th to the 19th centuries, these sites served as aquariums for the raising of selected fish. From its inception until the 1900's, the fishpond progressed little in design and function. Its rudimentary nature was a function of both technology and religion. Because of the open ditches, sluice grates, and permeable walls, neither the types nor the quantity of juvenile fish entering or leaving could be controlled. In addition, religious beliefs prevented experimenting with fertilization to increase yield. Although seemingly inefficient, the native aquacultural system was not intended to produce a great amount of fish but rather to yield selected fish on call. Fishponds became symbols of the chiefly right to conspicuous consumption and to ownership of the land and its resources. They were manifestations of the chief's political power and his ability to control and tap his resources. As soon as the native aristocracy changed to a Western-style kingdom, the fishpond's function changed, until, by the 1930's, the majority were simply archeological remains—mounds and walls of rock along a river or shore.
Calibrating Duckweeds: Light, Clocks, Metabolism, Flowering
Authors: Hillman William S.
Published: October 2006

The roles of photoperiodism and related light-dependent and hormonal processes in plants are not well understood. Rapid growth, aquatic habit, and adaptability to axenic culture make the Lemnaceae, or duckweeds, excellent material for investigating these topics and others in which highly defined conditions or the presence of organic substances are crucial. As a major example among several that are described, recent work with one species suggests a relation between some features of carbon dioxide flux and the photoperiodic timing mechanism, thus providing a system in which the biochemical basis of the latter may be explored.
Composition of the Atmosphere at the Surface of Mars: Detection of Argon-36 and Preliminary Analysis
Authors: Owen Tobias , Biemann K.
Published: October 2006

The composition of the martian atmosphere was determined by the mass spectrometer in the molecular analysis experiment. The presence of argon and nitrogen was confirmed and a value of 1 to 2750 ± 500 for the ratio of argon-36 to argon-40 was established. A preliminary interpretation of these results suggests that Mars had a slightly more massive atmosphere in the past, but that much less total outgassing has occurred on Mars than on Earth.
Viking Lander Location and Spin Axis of Mars: Determination from Radio Tracking Data
Authors: Michael W. H. , Tolson R. H. , Mayo A. P. , Blackshear W. T. , Kelly G. M. , Cain D. L. , Brenkle J. P. , Shapiro I. I. , Reasenberg R. D.
Published: October 2006

Radio tracking data from the Viking lander have been used to determine the lander position and the orientation of the spin axis of Mars. The areocentric coordinates of the lander are 22.27°N, 48.00°W, and 3389.5 kilometers from the center of mass; the spin axis orientation, referred to Earth's mean equator and equinox of 1950.0, is 317.35° right ascension and 52.71° declination.
City Size Effects, Trends, and Policies
Authors: Hoch Irving
Published: October 2006

As cities increase in size, so do wage rates for the same work. There is evidence that the wage differential is persistent and stable over time, which suggests that the differential does not arise from a lack of adjustment that is in process of correction. Indeed, there is an inverse relation between size and growth rate. Large metropolitan areas with high wage rates have been losing population in recent years, which is hardly a sign that their higher wage rates are temporary inducements to workers to move into those cities. It is much more plausible that the differential is a more-or-less permanent money payment that compensates urban residents for costs they bear as population size increases. This argument does not deny that there are nonwage benefits as well as costs of city size, that city size effects may vary between individuals and groups, or that there may be scope for improved policy on population distribution. Nonetheless, the benefits of size seem to be outweighed by the costs; all types and groups of people generally can and do move about until alternative locations are less attractive than their current location; and solutions to population distribution problems will often emerge as byproducts to the solutions of more basic problems.
Deep Current Measurements Suggest Long Waves in the Eastern Equatorial Pacific
Authors: Harvey Robert R. , Patzert William C.
Published: October 2006

During the 1975 El Niño expedition an array of conventional and electric field type near-bottom current recorders was deployed at the equator 300 kilometers west of the Galápagos Islands. While hydrographic observations were indicating El Niño activity off the South American coast, the current meters recorded an oscillation with a 25-day period, a wavelength of about 1000 kilometers, and an amplitude of 0.04 meter per second propagating westward at approximately 0.5 meter per second. These characteristics agree with theoretical models of a first-mode baroclinic Rossby wave trapped at the equator.
Solar Neutrinos: Proposal for a New Test
Authors: Freedman Melvin S. , Stevens Charles M. , Horwitz E. Philip , Fuchs Louis H. , Lerner Jerome L. , Goodman Leonard S. , Childs William J. , Hessler Jan
Published: October 2006

The predicted flux on the earth of solar neutrinos has eluded detection, confounding current ideas of solar energy production by nuclear fusion. The dominant low-energy component of that flux can be detected by mass-spectrometric assay of the induced tiny concentration of 1.6 × 10
7
year lead-205 in old thallium minerals. Comments are solicited from those in all relevant disciplines.
Tumor Cell Collagenase and Its Inhibition by a Cartilage-Derived Protease Inhibitor
Authors: Kuettner Klaus E. , Soble Lawrence , Croxen Richard L. , Marczynska Barbara , Hiti Judith , Harper Elvin
Published: October 2006

Human osteosarcoma and mammary carcinoma cells were cultured separately in a medium supplemented with fetal calf serum, until they were confluent. The medium was then replaced by serum-free medium supplemented with heparin. Both cell cultures secreted collagenase, and this activity was inhibited by a cartilage-derived protein of low molecular weight. Since cartilage is rarely invaded by neoplasms, the presence of this inhibitor may play an important role in the regulation of tumor invasion.
Gating of Neuronal Transmission in the Hippocampus: Efficacy of Transmission Varies with Behavioral State
Authors: Winson Jonathan , Abzug Charles
Published: October 2006

Electrical stimuli were applied to the angular bundle of the freely moving rat, and the neuronal responses were recorded ipsilaterally in the dentate gyrus and the CA
1
field of the hippocampus. The number of neurons responding monosynaptically in the dentate gyrus was relatively small when the animal was alert and not moving but was much greater both during slow-wave sleep and during rapid eye movement sleep. In CA
1
, however, the trisynaptic population response was considerably smaller during rapid eye movement sleep and when the animal was alert than during slow-wave sleep. These findings are interpreted in terms of a set of behaviorally dependent "neural gates." Measurement of the synaptic current at the dentate gyrus induced monosynaptically by stimulation of the angular bundle further suggests that the mechanism by which gating occurs at this level is either a tonic inhibitory synaptic influence exerted upon the granule cells during the alert state, a tonic excitatory influence during slow-wave sleep, or both.
Preceramic Animal Utilization in the Central Peruvian Andes
Authors: Pires-Ferreira Jane Wheeler , Pires-Ferreira Edgardo , Kaulicke Peter
Published: October 2006

The analysis of animal bones recovered from preceramic period deposits at Uchcumachay Cave and other sites in the Puna of Junín has documented the development of an economy involving primary camelid utilization beginning around 5,500 B.C. and culminating with the appearance of domestic forms between 2,500 and 1,750 B.C. A model that can be used to explain this process in both the Puna of Junín and the Central Andes has been presented.
Ultragiant Urban Aerosol Particles
Authors: Johnson David B.
Published: October 2006

Measurements taken 300 meters above ground level show surprisingly high concentrations of ultragiant aerosol particles both upwind and downwind of the St. Louis, Missouri, urban area. Assuming an average particle density of 2.0 grams per cubic centimeter, concentrations of particles with diameters between 5 and 55 micrometers sampled on 11 different days averaged 31 micrograms per cubic meter upwind and 55 micrograms per cubic meter downwind of the city.
North Polar Region of Mars: Imaging Results from Viking 2
Authors: Cutts James A. , Blasius Karl R. , Briggs Geoffrey A. , Carr Michael H. , Greeley Ronald , Masursky Harold
Published: October 2006

During October 1976, the Viking 2 orbiter acquired approximately 700 high-resolution images of the north polar region of Mars. These images confirm the existence at the north pole of extensive layered deposits largely covered over with deposits of perennial ice. An unconformity within the layered deposits suggests a complex history of climate change during their time of deposition. A pole-girdling accumulation of dunes composed of very dark materials is revealed for the first time by the Viking cameras. The entire region is devoid of fresh impact craters. Rapid rates of erosion or deposition are implied. A scenario for polar geological evolution, involving two types of climate change, is proposed.
Mars: Northern Summer Ice Cap—Water Vapor Observations from Viking 2
Authors: Farmer Crofton B. , Davies Donald W. , LaPorte Daniel D.
Published: October 2006

Observations of the latitude dependence of water vapor made from the Viking 2 orbiter show peak abundances in the latitude band 70° to 80° north in the northern midsummer season (planetocentric longitude ∼ 108°). Total column abundances in the polar regions require near-surface atmospheric temperatures in excess of 200°K, and are incompatible with the survival of a frozen carbon dioxide cap at martian pressures. The remnant (or residual) north polar cap, and the outlying patches of ice at lower latitudes, are thus predominantly water ice, whose thickness can be estimated to be between 1 meter and 1 kilometer.
Physiological Evidence for Habenula as Major Link Between Forebrain and Midbrain Raphe
Authors: Wang Rex Y. , Aghajanian George K.
Published: October 2006

The lateral habenula is one of the few forebrain areas that project to the midbrain raphe nuclei. Electrical stimulation of the habenula markedly suppressed serotonergic neurons in the midbrain raphe. The suppression was blocked by systemic or microiontophoretic administration of picrotoxin, which suggests that γ-aminobutyric acid is the inhibitory transmitter in the habenula-raphe pathway. These results support the concept that the habenula may serve a pivotal role in funneling information from the forebrain to the midbrain raphe.
A Neural Mechanism for Working and Recognition Memory in Inferior Temporal Cortex
Authors: Miller Earl K. , Li Lin , Desimone Robert
Published: October 2006

Inferior temporal (IT) cortex is critical for visual memory, but it is not known how IT neurons retain memories while new information is streaming into the visual system. Single neurons were therefore recorded from IT cortex of two rhesus monkeys performing tasks that required them to hold items in memory while concurrently viewing other items. The neuronal response to an incoming visual stimulus was attenuated if it matched a stimulus actively held in working memory, even when several other stimuli intervened. The neuronal response to novel stimuli declined as the stimuli became familiar to the animal. IT neurons appear to function as adaptive mnemonic "filters" that preferentially pass information about new, unexpected, or not recently seen stimuli.
Rous Sarcomas in Chickens: Enhanced Growth Coexisting with Concomitant Immunity
Authors: McBride Raymond A. , Watanabe Daniel H. , Schierman Louis W.
Published: October 2006

Chickens bearing Rous sarcoma virus-induced tumors in one wing did not develop new tumors when subsequently inoculated with Rous sarcoma virus in the other wing. However, the second inoculation of Rous sarcoma virus caused accelerated growth of the established tumors. This phenomenon was found to be bursa-dependent. Paradoxically, established tumors in bursectomized chickens grew at a diminished rate if the chickens were reinoculated with Rous sarcoma virus.
Concorde Sonic Booms as an Atmospheric Probe
Authors: Balachandran Nambath K. , Donn William L. , Rind David H.
Published: October 2006

Infrasound generated by the sonic boom from the inbound Concorde supersonic transport is recorded at Palisades, New York (Lamont-Doherty Geological Observatory), as a series of impulses from distances varying from 165 to about 1000 kilometers. Refraction effects determined by temperature and wind conditions return the signal to the surface from both stratospheric (40 to 50 kilometers) and thermospheric (100 to 130 kilometers) levels. The frequency of the recorded signal is a function of the level of reflection; the frequency decreases from impulse stretching as the atmosphere becomes more rarified relative to the sound pressure. The horizontal trace velocity of the signal across the array of instruments is equal to the acoustic velocity at the reflection level. The sonic boom can thus be used to provide temperature-wind parameters at reflection levels estimated from the signal frequency. Daily observed signal variations have indicated significant variations in these parameters.
Somali Current: Recent Measurements During the Southwest Monsoon
Authors: Bruce J. G.
Published: October 2006

The Somali Current was measured at approximately maximum strength for the year during the southwest monsoon on 11 and 12 August 1975 (approximately 1½ days) at stations spaced 20 to 35 kilometers apart. These measurements permit a nearly synoptic detailed mapping of the temperature structure of a major western boundary current.
Cubanite: A New Sulfide Phase in CI Meteorites
Authors: Macdougall J. D. , Kerridge J. F.
Published: October 2006

Cubanite (CuFe
2
S
3
), previously unobserved in meteorites, has been discovered in two carbonaceous chondrites, Orgueil and Alais. The association of this mineral with low-copper pyrrhotite suggests that it formed in a low-temperature environment on the meteorite parent body.
Mechanically Induced Wall Appositions of Plant Cells Can Prevent Penetration by a Parasitic Fungus
Authors: Aist James R.
Published: October 2006

Localized, paramural wall appositions resembling appositions commonly induced by fungal attack, were induced in kohlrabi (
Brassica oleracea
L.
gongyloides
) by mechanical wounding (bending) of the root hairs before the hairs were inoculated with zoospores of a compatible parasitic fungus. The appositions were effective in preventing fungal penetration at the wound sites, which shows that wall appositions can prevent fungal ingress into plant cells.
Detection of Lyman α Emission from the Saturnian Disk and from the Ring System
Authors: Weiser H. , Vitz R. C. , Moos H. W.
Published: October 2006

A rocket-borne spectrograph detected H I Lyman α emission from the disk of Saturn and from the vicinity of the planet. The signal is consistent with an emission brightness of 700 rayleighs for the disk and 200 rayleighs for the vicinity of Saturn. The emission from the vicinity of the planet may be due to a hydrogen atmosphere associated with the saturnian ring system.
Bacteria—Plant Cell Surface Interactions: Active Immobilization of Saprophytic Bacteria in Plant Leaves
Authors: Sing Venancio O. , Schroth Milton N.
Published: October 2006

Fibrillar structures, originating from the plant cell wall in the intercellular spaces of leaves of 'Red Kidney' bean,
Phaseolus vulgaris
L., engulfed a saprophytic bacterium,
Pseudomonas putida
after its initial attachment to the host walls. Phytopathogenic bacteria,
Pseudomonas phaseolicola
and
Pseudomonas tomato
, did not adhere to the plant cell wall nor were they encapsulated. Bean lectins may be involved in the attachment and encapsulation processes.
Geochemistry and Thermolysis of Flavonoids
Authors: Niklas Karl J. , Giannasi David E.
Published: October 2006

The thermal and
p
H stability of selected flavonoids has been determined under simulated geologic conditions. Thermolytic rates and products for various regimes, as determined by gas chromatography—mass spectroscopy, indicate the potential usefulness of flavonoids as thermometric indicators in sediments. The parametric factors affecting flavonoid stability are used to geochemically characterize angiosperm "green leaves" (36 to 25 × 10
6
years old) from Succor Creek and indicate that these sediments have not experienced temperatures higher than 80°C or extreme
p
H shifts (beyond the range 6.3 to 7.2) during postdepositional maturation.
The Oldest Macroborers: Lower Cambrian of Labrador
Authors: James N. P. , Kobluk D. R. , Pemberton S. G.
Published: October 2006

We have discovered numerous borings of
Trypanites
penetrating skeletons and synsedimentary cemented limestones in archaeocyathid reefs of the Forteau formation in southern Labrador. These are, to date, the oldest known macroborings. The discovery of these structures extends the record of large endolithic organisms 100 million years from the Lower Ordovician to the Lower Cambrian. This immediately postdates the appearance of metazoans with hard parts and confirms that endoliths have played a role in reef formation since the early Cambrian.
Lunar Surface Chemistry: A New Imaging Technique
Authors: Andre Constance G. , Bielefeld Michael J. , Eliason Eric , Soderblom Laurence A. , Adler Isidore , Philpotts John A.
Published: October 2006

Detailed chemical maps of the lunar surface have been constructed by applying a new weighted-filter imaging technique to Apollo 15 and Apollo 16 x-ray fluorescence data. The data quality improvement is amply demonstrated by (i) modes in the frequency distribution, representing highland and mare soil suites, which are not evident before data filtering and (ii) numerous examples of chemical variations which are correlated with small-scale (about 15 kilometer) lunar topographic features.
Alternative Astronomy: Experiment in Self-Sufficiency Blossoms
Authors: Hammond Allen L.
Published: October 2006

Half a dozen astronomy graduate students facing meager job prospects decide they would rather fight than switch. They drop out of the postdoctoral rat race, move to California, and establish a close-knit if impoverished community centered around astronomy. They build their own observatory complete with a telescope superior to those of many universities and incorporating the latest in modern electronic instruments, all the while maintaining their independence and doing without government grants. They undertake an ambitious research effort and win the respect, admiration, and even envy of prominent astronomers.
Detection and Examination of Anthrosols by Phosphate Analysis
Authors: Eidt Robert C.
Published: October 2006

Land-use analysis of anthrosols has been performed by a new, two-part method. A rapid qualitative field test assists in locating past settlements and determining their areal and temporal extent, even where artifacts are missing. The field-test results are verified and samples are analyzed further by quantitative soil phosphate fractionation. Laboratory fractionation reveals much more than the simple phosphate test used at present. Like the chemical field test, it uses minute soil samples and may be invaluable where disturbance of the landscape is forbidden. Phosphate fractions reflect the details of man-induced changes in the soil and the timing of their appearance.
Temperature Exposure Measured by the Use of Thermoluminescence
Authors: Romberg G. Patrick , Prepejchal W. , Spigarelli S. A.
Published: October 2006

A method has been developed to measure temperature exposure based on the use of the temperature-dependent property of thermoluminescence fade. This property provides a relatively simple and inexpensive method for measuring both average and accumulated temperature exposure without the need for sophisticated temperature-recording equipment.
Shared Actions of Endotoxin and Taxol on TNF Receptors and TNF release
Authors: Ding Aihao H. , Porteu Françoise , Sanchez Elizabeth , Nathan Carl F.
Published: October 2006

Bacterial lipopolysaccharide (LPS) exerts profound effects on mammalian hosts in part by inducing macrophages to release tumor necrosis factor-α (TNF-α); the mechanisms involved are unresolved. The microtubule stabilizer taxol shared two actions of LPS on macrophages: it rapidly decreased TNF-α receptors and triggered TNF-α release. Both actions of taxol were absent in LPS-hyporesponsive C3H/HeJ mice. In recombinant inbred mice, the genes controlling responses to LPS and to taxol were closely linked. Dexamethasone blocked release of TNF-α by both stimuli but did not block the decrease in TNF-α receptors. Thus, a protein associated with microtubules may be a cellular target of LPS.
Selective Destruction of Neurons by a Transmitter Agonist
Authors: Herndon Robert M. , Coyle Joseph T.
Published: October 2006

Microinjection of nanomole amounts of kainic acid, a heterocyclic analog of glutamate, into the cerebellums of adult hamsters and rats causes rapid degeneration of Purkinje, basket, stellate, and Golgi II cells, neurons that receive synaptic input from granule cells, whereas the granule cells themselves are spared. This selectivity is consistent with the evidence that glutamate is the granule cell transmitter and supports the hypothesis that kainic acid exerts its neurotoxic effects through glutamate receptors.
Direct Evidence of Particle Migration in the Soil Solution of a Podzol
Authors: Ugolini F. C. , Dawson H. , Zachara J.
Published: October 2006

Particles were isolated from soil leachates from the genetic horizons of a subalpine Podzol from the central Cascades, Washington. Organic particles containing traces of aluminum, iron, silicon, and sulfur were predominant in the migrant material through the upper horizons (horizons A + B); their movement was arrested in the B2hir horizon. Below B2hir and at depth, phyllosilicates, quartz, and silicate minerals were the predominant suspended materials. Elements of the podzolic mechanism and the duality of the B2hir horizon are shown.
Anomalous Solar Rotation in the Early 17th Century
Authors: Eddy John A. , Gilman Peter A. , Trotter Dorothy E.
Published: October 2006

The character of solar rotation has been examined for two periods in the early 17th century for which detailed sunspot drawings are available: A.D. 1625 through 1626 and 1642 through 1644. The first period occurred 20 years before the start of the Maunder sunspot minimum, 1645 through 1715; the second occurred just at its commencement. Solar rotation in the earlier period was much like that of today. In the later period, the equatorial velocity of the sun was faster by 3 to 5 percent and the differential rotation was enhanced by a factor of 3. The equatorial acceleration with declining solar activity is in the same sense as that found in recent Doppler data. It seems likely that the change in rotation of the solar surface between 1625 and 1645 was associated with the onset of the Maunder Minimum.
Oxygen Isotopic Analysis of the Size Fraction Between 62 and 250 Micrometers in Caribbean Cores P6304-8 and P6304-9
Authors: Emiliani Cesare
Published: October 2006

Oxygen isotopic analysis of the carbonate sediment fraction between 62 and 250 micrometers yields curves following the general trend of those obtained from
Globigerinoides sacculifera
. Warm stages 11, 13, and 15 are characterized by heavy postdepositional solution. which makes the sediment fraction between 62 and 250 micrometers rich in shell fragments of the more resistant, deeper-living species. As a result, oxygen isotopic analysis of these samples yields comparatively low temperatures, in contrast to those obtained from
Globigerinoides sacculifera
.
CCAAT-Enhancer Binding Protein: A Component of a Differentiation Switch
Authors: Umek Robert M. , Friedman Alan D. , McKnight Steven L.
Published: October 2006

The CCAAT-enhancer binding protein (C/EBP) has now been found to promote the terminal differentiation of adipocytes. During the normal course of adipogenesis, C/EBP expression is restricted to a terminal phase wherein proliferative growth is arrested, and specialized cell phenotype is first manifested. A conditional form of C/EBP was developed, making it feasible to test its capacity to regulate the differentiation of cultured adipocytes. Premature expression of C/EBP in adipoblasts caused a direct cessation of mitotic growth. Moreover, when abetted by the effects of three adipogenic hormones, C/EBP promoted terminal cell differentiation. Since C/EBP is expressed in a variety of tissues, it may have a fundamental role in regulating the balance between cell growth and differentiation in higher animals.
Altered Perception of Species-Specific Song by Female Birds After Lesions of a Forebrain Nucleus
Authors: Brenowitz Eliot A.
Published: October 2006

Female birds that do not normally sing possess brain nuclei associated with song production in males. To determine whether one song nucleus, the caudal nucleus of the ventral hyperstriatum (HVc), acts in conspecific song perception, courtship responses of female canaries to canary and white-crowned sparrow songs were compared before and after HVc lesions. Bilateral lesions of a portion of the HVc resulted in copulation solicitations to heterospecific song as well as conspecific song. Control females continued to respond only to conspecific song. This suggests that the HVc is critical for conspecific song perception in females. Because female canaries do not normally sing, neurons in female HVc must develop response selectivity by a mechanism different from that proposed for male birds in the motor theory of song perception.
The Effect of Anti-Neoplastic Drugs on Murine Acquired Immunodeficiency Syndrome
Authors: Simard Carole , Jolicoeur Paul
Published: October 2006

The murine acquired immunodeficiency syndrome (MAIDS) is associated with proliferation of target cells that have been infected by a defective retrovirus. To control the growth of this primary neoplasia, virus-inoculated mice were treated with anti-neoplastic drugs. Paradoxically, cyclophosphamide, which is also immunosuppressive, was very effective in preventing the appearance and progression of the disease, in restoring a normal T cell function, and in depleting the number of infected target cells. This result suggests that the proliferating infected target cells were responsible for the immunodeficiency.
Somatically Evoked Magnetic Fields of the Human Brain
Authors: Brenner D. , Lipton J. , Kaufman L. , Williamson S. J.
Published: October 2006

The human brain is found to produce a magnetic field near the scalp which varies in synchrony with periodic electrical stimulation applied to a finger. Use of a highly sensitive superconducting quantum interference device as a magnetic field detector reveals that the brain's field is sharply localized over the primary projection area of the sensory cortex contralateral to the digit being stimulated. The phase of the response at the stimulus frequency varies monotonically with the repetition rate and at intermediate frequencies yields a latency of approximately 70 milliseconds for cortical response.
Axial Differences in the Musculature of Uropeltid Snakes: The Freight-Train Approach to Burrowing
Authors: Gans Carl , Dessauer Herbert C. , Baic Dusan
Published: October 2006

The shield-tailed snakes (family Uropeltidae) extend and widen the tunnels in which they live by alternately curving and straightening the anterior portion of their vertebral columns within the skin, a burrowing method that proves to be most effective for tunneling amid roots and rocks, as well as for producing tunnels wider than the trunk through unpredictably heterogeneous substrates. The muscles of the anterior portion of the uropeltid trunk are larger and thicker than those of the posterior and are further modified by the inclusion of large amounts of myoglobin, numerous mitochondria, and diverse other ultrastructural and enzymatic specializations, which presumably represent adaptations for sustained work loads. The very much thinner, serially homologous, but unmodified musculature of the posterior trunk occupies only a much smaller fraction of the cross-sectional area. This regional modification increases the effectiveness of the posterior body for storing viscera and developing embryos.
Serengeti Ungulates: Feeding Selectivity Influences the Effectiveness of Plant Defense Guilds
Authors: McNaughton S. J.
Published: October 2006

Association of
Themeda triandra
, a palatable grass species, with less palatable plants protected it from grazing by two comparatively unselective herbivores, wildebeest and African buffalo. Grazing on
T. triandra
by two more selective herbivores, Thomson's gazelle and zebra, was not related to the relative abundance of less palatable plants. The differential effectiveness of plant defense guilds against different ungulates may contribute to the high species diversity of the East African grazer fauna.
Nitrogen Fixation and Delayed Leaf Senescence in Soybeans
Authors: Abu-Shakra Salah S. , Phillips Donald A. , Huffaker Ray C.
Published: October 2006

Delayed leaf senescence has been found in a soybean population which maintains its chlorophyll and ribulosebisphosphate carboxylase activity in leaves and nitrogen fixation (acetylene reduction) activity in root nodules throughout seed maturation. Incorporation of delayed leaf senescence into an agronomically desirable genetic background may help to increase seed yield and symbiotic nitrogen fixation during seed development.
Cortical Computational Maps Control Auditory Perception
Authors: Riquimaroux Hiroshi , Gaioni Stephen J. , Suga Nobuo
Published: October 2006

Mustached bats orient and find insects by emitting ultrasonic pulses and analyzing the returning echoes. Neurons in the Doppler-shifted constant-frequency (DSCF) and frequency-modulated (FM-FM) areas of the auditory cortex form maps of echo frequency (target velocity) and echo delay (target range), respectively. Bats were trained to discriminate changes in echo frequency or delay, and then these areas were selectively inactivated with muscimol. Inactivation of the DSCF area disrupted frequency but not delay discriminations; inactivation of the FM-FM area disrupted delay but not frequency discriminations. Thus, focal inactivation of specific cortical maps produces specific disruptions in the perception of biosonar signals.
Protein Kinase C and Regulation of the Local Competence of
Xenopus
Ectoderm
Authors: Otte Arie P. , Kramer Ijsbrand M. , Durston Antony J.
Published: October 2006

The limited competence of embryonic tissue to respond to an inductive signal has an essential, regulatory function in embryonic induction. The molecular basis for the competence of
Xenopus
ectoderm to differentiate into neural tissue was investigated. Dorsal mesoderm or 12-
O
-tetradecanoyl phorbol-13-acetate (TPA) caused in vivo activation of protein kinase C (PKC) and neural differentiation mainly in dorsal ectoderm and to a lesser extent in ventral ectoderm. These data correlate with the observations that PKC preparations from dorsal and ventral ectoderm differ, the dorsal PKC preparation being more susceptible to activation by TPA and diolein than is the ventral PKC preparation. Monoclonal antibodies against the bovine PKC α plus β or γ isozymes immunostained dorsal and ventral ectoderm, respectively, which suggests different localizations of PKC isozymes. These results suggest that PKC participates in the establishment of embryonic competence.
Characterization of a Dimerization Motif in AP-2 and Its Function in Heterologous DNA-Binding Proteins
Authors: Williams Trevor , Tjian Robert
Published: October 2006

The mammalian transcription factor AP-2 is a retinoic acid inducible sequence-specific DNA-binding protein that is developmentally regulated. In this report, the functional domains necessary for AP-2 DNA binding were studied. AP-2 required a dimerization domain and an adjacent region of net basic charge to achieve a sequence-specific protein:DNA interaction. The sequences responsible for dimerization consisted of two putative amphipathic alpha helices separated by a large intervening span region. This helix-span-helix (HSH) domain was unable to bind DNA when separated from the basic region, but was still capable of dimerization. The ability of the HSH domain to function as a module that promotes DNA binding through dimerization was further demonstrated by attaching it to the heterologous basic region of the c-Jun proto-oncogene product. The resulting chimeric protein specifically recognized an AP-1 DNA-binding site in the absence of an intact c-Jun leucine repeat and in a manner that was dependent on the presence of a functional AP-2 dimerization domain.
"Helium Spots": Caused by a Diapiric Magma from the Upper Mantle
Authors: Wakita Hiroshi , Fujii Naoyuki , Matsuo Sadao , Notsu Kenji , Nagao Keisuke , Takaoka Nobuo
Published: October 2006

"Helium spots," where a significant amount of helium is present in the soil [up to 350 parts per million with a high
3
He to
4
He ratio of (8.90 ± 0.31) × 10
–6
], have been found along the fault zone formed by the 1966 Matsushiro swarm earthquakes. The formation of the "helium spots" and the occurrence of the earthquakes are interpreted as the results of a diapiric uprise of a magma approximately 1 kilometer in diameter.
A New High-Pressure Form of Sulfur Derived from the Decomposition of S
4
N
4
Authors: Vezzoli Gary C. , Abel James
Published: October 2006

A new phase of sulfur is formed from S
4
N
4
held at pressure-temperature conditions in the vicinity of the boundary representing the decomposition of S
4
N
4
to fibrous sulfur, S
x
.
The new phase is gray-black, is persistently metastable at room conditions, and is insoluble in carbon disulfide. The phase is apparently formed from a stage of decomposition during which high-conductance transients are observed in in situ electrical experiments. The sulfur phase appears to form upon the release of the nitrogen from a sulfur-nitrogen chain that is produced from the scission of an S
4
N
4
ring
.
Allylglucosinolate and Herbivorous Caterpillars: A Contrast in Toxicity and Tolerance
Authors: Blau Patricia A. , Feeny Paul , Contardo Lorraine , Robson Douglas S.
Published: October 2006

Allylglucosinolate, found in many cruciferous plants, is acutely toxic to
Papilio polyxenes
larvae, which do not normally attack crucifers. By contrast, larval growth of
Pieris rapae
, a crucifer specialist, is not affected even by artificially high concentrations of allylglucosinolate. Larval growth of
Spodoptera eridania
a generalist feeder, is inhibited by high but not by low concentrations of the compound.
Congress Considers Bill to Control Angel Dust
Authors: Smith R. Jeffrey
Published: October 2006

"It gave me a feeling of importance, you know, kind of like, I felt like I was the whole—the whole world was revolving around me ... where you feel like you are that important and you find yourself withdrawing from everything that is real, and you live in a type of spiritualistic level, like everything is very symbolic, everything has double meanings and [you] completely lose touch with yourself."—Illicit user of PCP testifying during U.S. Senate hearings on a bill to control sales of the drug's chemical ingredients.
Correction: Comparison of Two Forms of Long-Term Potentiation in Single Hippocampus Neurons
Authors: Zalutsky Robert A. , Nicoll Roger A.
Published: October 2006

In reviewing the data in our Research Article "Comparison of two forms of long-term potentiation in single hippocampus neurons" (29 June, p. 1619) [
Science
248, 1619 (1990)], we discovered that we made an error in composing one of the figures. The trace examples in figure 4C (p. 1622) were said to be from the mossy fiber pathway to a single cell from the experiment summarized in 4B. The "during tetanus" trace was as stated, but the "control" and "LTP" traces were not from the same recording, as is obvious from close inspection of the waveform and latencies. We show below the "control" and "LTP" traces from that cell.

[See figure in the PDF file]
Mutations Affecting Internal TEA Blockade Identify the Probable Pore-Forming Region of a K
+
Channel
Authors: Yellen Gary , Jurman Mark E. , Abramson Tatiana , MacKinnon Roderick
Published: October 2006

The active site of voltage-activated potassium channels is a transmembrane aqueous pore that permits ions to permeate the cell membrane in a rapid yet highly selective manner. A useful probe for the pore of potassium-selective channels is the organic ion tetraethylammonium (TEA), which binds with millimolar affinity to the intracellular opening of the pore and blocks potassium current. In the potassium channel encoded by the
Drosophila
Shaker
gene, an amino acid residue that specifically affects the affinity for intracellular TEA has now been identified by site-directed mutagenesis. This residue is in the middle of a conserved stretch of 18 amino acids that separates two locations that are both near the external opening of the pore. These findings suggest that this conserved region is intimately involved in the formation of the ion conduction pore of voltage-activated potassium channels. Further, a stretch of only eight amino acid residues must traverse 80 percent of the transmembrane electric potential difference.
Avian Pollination Studies: A Simple Scanning Electron Microscopic Technique
Authors: Boeke Jef D. , Ortiz-Crespo Fernando I.
Published: October 2006

Identifying ornithophilous plant species utilized by several different flower-visiting birds is simplified by the scanning electron microscope. The technique involves comparing pollen samples taken from the birds' head feathers with pollen reference standards collected in the same area, which simplifies analysis of pollination patterns in a complex community.
Deuterated Methane Observed on Saturn
Authors: Fink Uwe , Larson Harold P.
Published: October 2006

Absorptions for the ν
2
band of deuterated methane (CH
3
D) have been observed in the 5-micron spectrum of Saturn, obtained with a Fourier transform spectrometer. Analysis of the band yields a CH
3
D abundance of 2.6 ± 0.8 centimeter-amagat and a temperature of 175 ± 30 K for the mean level of spectroscopic line formation. This temperature indicates that a substantial portion of Saturn's flux at 5 microns is due to thermal radiation, and that we are therefore looking fairly deep into its atmosphere, as is the case for the Jupiter 5-micron window. This CH
3
D abundance leads to a deuteriumlhydrogen ratio of about 2 × 10
-5
in Saturn's atmosphere. This ratio is much lower than the terrestrial value but comparable to that determined for Jupiter and may be taken as representative of the deuterium/hydrogen ratio in the solar system at the time of its formation.
Radioisotope Dating with an Accelerator: A Blind Measurement
Authors: Muller Richard A. , Stephenson Edward J. , Mast Terry S.
Published: October 2006

The age of a sample of carbon dioxide has been determined by accelerating the carbon with a cyclotron and detecting the carbon-14 ions in the beam. Nitrogen-14 was eliminated as a background through the use of a range-separation technique. To avoid all possibility of experimenter bias, the measurement was conducted in a blind fashion.
Devonian Brachiopods from the Sillimanite Zone, Mount Moosilauke, New Hampshire
Authors: Boucot A. J. , Rumble Douglass
Published: October 2006

Devonian brachiopods, identifiable at the generic level, have been recovered from calc-silicate rocks more intensely metamorphosed and metasomatized than any other known fossil occurrence. The fossils are a key stratigraphic link between granulite facies rocks of central New Hampshire and fossiliferous rocks of western New Hampshire and Maine.