bluuebunny/crossref_metadata_2025 huggingface dataset:
CHESS: The New Synchrotron Radiation Facility at Cornell
Authors: Batterman Boris W. , Ashcroft Neil W.
Published: October 2006

A new synchrotron radiation laboratory, CHESS, will soon be completed at Cornell University. The facility will operate in a mode parasitic to high energy physics experiments on the new 8-billion-electron-volt electron-positron storage ring (CESR) at Cornell. Electron and positron beams have already been stored and the first photons have been extracted. When completed, the laboratory will be available to the scientific community nationally and will provide the most intense tunable source of high energy x-rays in the country.
Synthesis of Lipid During Photosynthesis by Phytoplankton of the Southern Ocean
Authors: Smith Andrew E. , Morris Ian
Published: October 2006

Assimilation of carbon-14 labeled bicarbonate into photosynthetic products was measured at four stations in the Southern Ocean. Phytoplankton populations incorporated as much as 80 percent of the fixed carbon into lipid under conditions of low temperatures (–0.2° to –1.8°C) and low light intensities. At higher temperatures (+0.3° to +0.8°C) and higher light intensities, incorporation into lipid accounted for less than 20 percent of the fixed carbon, synthesis of polysaccharide and protein being more prominent.
Mount St. Helens, Washington, 1980 Volcanic Eruption: Magmatic Gas Component During the First 16 Days
Authors: Stoiber Richard E. , Williams Stanley N. , Malinconico Lawrence L.
Published: October 2006

Eruption plumes of Mount St. Helens, Washington, showed low rates of sulfur dioxide emission, and ash leachates had low ratios of sulfur to chlorine. These data and the nonvesicularity of ash fragments are indicative of only a small eruptive magmatic component. The low amounts of soluble fluorine on the ashes pose no health problems. Violent magmatic activity is possible, and thus continued geochemical monitoring is advised.
Atmospheric Water Uptake by an Atacama Desert Shrub
Authors: Mooney H. A. , Gulmon S. L. , Ehleringer J. , Rundel P. W.
Published: October 2006

Nolana mollis
, a succulent-leaved shrub of the extreme coastal desert of Chile, has the capacity to condense water on its leaves out of unsaturated atmospheres, Metabolic energy would have to be expended to move this water either from the leaf surface directly to the mesophyll or, when dripped to the soil, from there into the roots. Because of the unusual aridity of its habitat and of the utilization of water-use-efficient metabolism by
Nolana
, at least during certain periods, such an energy expenditure could be effective.
Composition of the Mount St. Helens Ashfall in the Moscow-Pullman Area on 18 May 1980
Authors: Hooper P. R. , Herrick I. W. , Laskowski E. R. , Knowles C. R.
Published: October 2006

Mineralogical and chemical analyses of the ashfall from Mount St. Helens on 18 May 1980 indicate that there were two distinct ashes. The early dark ash is composed principally of plagioclase and lithic fragments of plagioclase and glass with titanium-rich magnetite and some basaltic hornblende and orthopyroxene. The later pale ash, four-fifths by weight of the whole fallout, is 80 percent glass with plagioclase as the principal crystalline phase. Quartz and potassium feldspar are rare to absent in both ashes. Chemical analyses of nine ash fractions and of the glass in each type emphasize the differences between the two ash types and their chemical homogeneity.
Carbon Budget of the Southeastern U.S. Biota: Analysis of Historical Change in Trend from Source to Sink
Authors: Delcourt Hazel R. , Harris W. F.
Published: October 2006

Documentation of settlement patterns and deforestation in the southeastern United States allows evaluation of regional carbon dynamics since A.D. 1750. From 1750 to 1950, the Southeast was a net source for carbon at an average rate of 0.13 gigaton per year. Only in the past 20 to 30 years has increased productivity of commercial forests resulted in a sink for atmospheric carbon dioxide of 0.07 gigaton per year.
Gaseous Constituents in the Plume from Eruptions of Mount St. Helens
Authors: Inn Edward C. Y. , Vedder James F. , Condon Estelle P. , O'Hara Dean
Published: October 2006

Measurements in the stratosphere of gaseous constituents in the plume of Mount St. Helens were obtained during five flights of the NASA U-2 aircraft between 19 May and 17 June 1980. Mixing ratios from gas chromatographic measurements on samples acquired about 24 hours after the initial eruption show considerable enhancement over nonvolcanic concentrations for sulfur dioxide (more than 1000 times), methyl chloride (about 10 times), and carbon disulfide (more than 3 times). The mixing ratio of carbonyl sulfide was comparable to nonvolcanic mixing ratios although 3 days later it was enhanced two to three times. Ion chromatography measurements on water-soluble constituents are also reported. Very large concentrations of chloride, nitrate, and sulfate ions were measured, implying large mixing ratios for the water-soluble gaseous constituents from which the anions are derived. Measurements of radon-222 present in the plume are also reported.
Identification of Small Clusters of Divergent Amino Acids that Mediate the Opposing Effects of
ras
and K
rev
-1
Authors: Zhang Ke , Noda Mazkoto , Vass William C. , Papageorge Alex G. , Lowy Douglas R.
Published: October 2006

K
rev
-1 is an anti-oncogene that was originally identified by its ability to induce morphologic reversion of
ras
-transformed cells that continue to express the
ras
gene. The K
rev
-1-encoded protein is structurally related to Ras proteins. The biological activities of a series of
ras
-K
rev
-1 chimeras were studied to test the hypothesis that K
rev
-1 may directly interfere with a
ras
function. The
ras
-specific and K
rev
-1-specific amino acids immediately surrounding residues 32 to 44, which are identical between the two proteins, determined whether the protein induced cellular transformation or suppressed
ras
transformation. Because this region in Ras proteins has been implicated in effector function, the results suggest that K
rev
-1 suppresses
ras
-induced transformation by interfering with interaction of Ras with its effector.
Geotropism in Corn Roots: Evidence for Its Mediation by Differential Acid Efflux
Authors: Mulkey Timothy J. , Evans Michael L.
Published: October 2006

The elongation zone in intact growing corn roots secretes acid leading to a reduced
p
H along the surface of the root and in the adjacent medium. This can be detected by placing the root on an agar medium containing The
p
H indicator dye bromocresol purple. When the root is treated with a growth inhibitory concentration of the hormone indole-3-acetic acid, the acid efflux is reversed and growth is greatly retarded. When the root is mounted vertically, acid secretion is uniform along the elongation zone, and the root grows straight downward. When the root is placed horizontally, there is enhanced acid efflux along the upper surface of the elongation zone and reduced acid efflux along the lower surface. An increased rate of elongation of the upper cells relative to the lower cells then results in downward curvature of the root. The correlation between acid efflux patterns and growth patterns indicates that proton efflux is important in the control of root growth.
Two-Hundred-Million-Year-Old Chromosomes: Deceleration of the Rate of Karyotypic Evolution in Turtles
Authors: Bickham John W.
Published: October 2006

Cladistic analyses of chromosomal banding patterns from 48 species of cryptodiran turtles, combined with a fossil-based method for estimating rates of karyotypic change, show that karyotypic evolution was twice as fast and involved different types of rearrangements in Mesozoic turtles when compared to more recent forms. The deceleration in rate of karyotypic change is correlated with decelerated morphological change and is indicative of adaptive evolution. Comparisons of banded karyotypes reveal that some chromosomes have remained unchanged for at least 200 million years.
The Function of a Leader Peptide in Translocating Charged Amino Acyl Residues Across a Membrane
Authors: Rohrer Jack , Kuhn Andreas
Published: October 2006

Insertion of bacteriophage coat proteins into the membrane of infected bacterial cells can be studied as a model system of protein translocation across membranes. The coat protein of the filamentous bacteriophage Pf3—which infects
Pseudomonas aeruginosa
—is 44 amino acids in length and has the same basic structure as the coat protein of bacteriophage M13, which infects
Escherichia coli
. However, unlike the Pf3 coat protein, the M13 coat protein is synthesized as a precursor (procoat) with a typical leader (signal) sequence, which is cleaved after membrane insertion. Nevertheless, when the gene encoding the Pf3 coat protein is expressed in
E. coli
, the protein is translocated across the membrane. Hybrid M13 and Pf3 coat proteins were constructed in an attempt to understand how the Pf3 coat protein is translocated without a leader sequence. These studies demonstrated that the extracellular regions of the proteins determined their cellular location. When three charged residues in this region were neutralized, the leader-free M13 coat protein was also inserted into the membrane. Differences in the water shell surrounding these residues may account for efficient membrane insertion of the protein without a leader sequence.
Producer Gas Engines in Villages of Less-Developed Countries
Authors: Datta Rathin , Dutt Gautam S.
Published: October 2006

Producer gas engines could have an important role in the decentralized production of mechanical energy in rural areas of less-developed countries. With this technology mechanical energy is produced from solid fuels by use of internal combustion engines. A comparison with other renewable energy options, on the common basis of energy efficiency and economics, shows that producer gas engines may have significant advantages and deserve serious attention.
Functional Characteristics of the Blood of the Deep-Sea Hydrothermal Vent Brachyuran Crab
Authors: Arp Alissa J. , Childress James J.
Published: October 2006

Hemocyanin in the whole blood of the hydrothermal vent brachyuran crab,
Bythograea thermydron
, has a moderate oxygen affinity (P
50
= 6.6 millimeters of mercury at 2.6°C;
p
H 7.5), which unlike that of other hemocyanins is independent of temperature over the range 2° to 30°C; carbon dioxide and
p
H have independent effects on the oxygen affinity of this pigment. The
p
H effect on affinity is moderate (Δlog P
50
/Δ
p
H = –0.34), whereas increased carbon dioxide, which can act both directly and by changing
p
H, has a much larger effect (Δlog P
50
/Δ
p
H = –0.81). This blood has a moderately high degree of cooperativity (Hill cooperativity coefficient, n, was 2.8) and a large oxygen-carrying capacity for a crustacean (4.5 milliliters of oxygen per 100 milliliters of blood). These properties characterize an oxygen transport system whose function appears to be largely independent of the wide range of environmental conditions encountered around the vents.
Extrinsic Microbial Degradation of the Alligator Eggshell
Authors: Ferguson Mark W. J.
Published: October 2006

The outer, densely calcified layer of the alligator eggshell shows progressive crystal dissolution, with the production of concentrically stepped erosion craters, as incubation progresses. This dissolution is caused by the acidic metabolic by-products of nest bacteria. Extrinsic degradation serves to gradually increase the porosity and decrease the strength of the eggshell.
Photosynthesis in Copepods
Authors: Epp Robert W. , Lewis William M.
Published: October 2006

Zooplankton grazers consume appreciable amounts of algae that are not digested. Indigestibility has been considered of adaptive value to the algae and an unqualified disadvantage to the grazer. In Cartesian diver experiments, freshly killed copepods (
Acanthocyclops vernalis
) produced significant amounts of oxygen when exposed to the light, even after 24 hours of starvation. Also, significant amounts of oxygen were consumed by dead copepods in the dark. These observations suggest that the copepod gut is well suited for photosynthesis by ingested algae.
Voyager 2 Encounter with the Saturnian System
Authors: Stone E. C. , Miner E. D.
Published: October 2006

An overview of the Voyager 2 encounter with Saturn is presented, including a brief discussion of the trajectory, the planned observations, and highlights of the results described in the subsequent reports.
Slowly Dechlorinated Organic Chloramines
Authors: Stanbro William D. , Lenkevich Michael J.
Published: October 2006

Dechlorination of some organic chloramines with aqueous sulfite solutions does not take place instantaneously as previously assumed. Field dechlorination times on the order of hours for some compounds that are found in chlorinated effluents appear likely on the basis of laboratory studies. These chlorinated compounds are not detected by standard analytical methods in the presence of sulfite ion.
Computer-Detected Patterns of Electroencephalographic Delta Activity During and After Extended Sleep
Authors: Feinberg I. , Fein G. , Floyd T. C.
Published: October 2006

Delta (0.5 to 3 hertz) waves are the electroencephalographic hallmark of human sleep. We measured their rate of production during and following an extended night of sleep. On the extended night, we confirmed previous observations of a linear decline in delta wave production across the first four periods of non-rapid-eye-movement (non-REM) sleep. An asymptote was reached in the fifth non-REM period, perhaps signifying that sleep processes reached completion. On the day after the extended night, subjects were allowed to remain awake 3.6 hours less than normal. During the next sleep session, amplitude and number of delta waves in non-REM periods 1 and 3 were significantly reduced. These findings illustrate the value of computer analysis of electroencephalographic waveforms in sleep. Systematic measurement of the amount and distribution of these waveforms as a function of preceding waking duration should provide clues to the kinetics of the metabolic processes underlying sleep.
Nuclear Reactor Safety Research Since Three Mile Island
Authors: Mynatt F. R.
Published: October 2006

The Three Mile Island nuclear power plant accident has resulted in redirection of reactor safety research priorities. The small release to the environment of radioactive iodine—13 to 17 curies in a total radioactivity release of 2.4 million to 13 million curies—has led to a new emphasis on the physical chemistry of fission product behavior in accidents; the fact that the nuclear core was severely damaged but did not melt down has opened a new accident regime—that of the degraded core; the role of the operators in the progression and severity of the accident has shifted emphasis from equipment reliability to human reliability. As research progresses in these areas, the technical base for regulation and risk analysis will change substantially.
Chemical Changes of Lakes Within the Mount St. Helens Blast Zone
Authors: Wissmar Robert C. , Devol Allen H. , Nevissi Ahmad E. , Sedell James R.
Published: October 2006

Differences in the dissolved chemistry of lakes devastated by the 18 May 1980 eruption of Mount St. Helens are attributable to location relative to the lateral blast trajectory of the eruption and to the emplacement of mineral deposits. Elemental enrichment ratios of pre- and posteruption measurements for Spirit Lake and comparisons of the chemical concentrations and elemental ratios for lakes inside and outside the blast zone reflect the influences of the dissolution of magmatic and lithic deposits. The
p
H changes were minor because of buffering by carbonic acid and reactions involving mineral alteration, dissolved organics, and biological processes.
Hydrocarbon Resources of the Eastern Overthrust Belt: A Realistic Evaluation
Authors: Hatcher Robert D.
Published: October 2006

By considering the present occurrence of hydrocarbons, past geologic conditions, and timing of deposition, deformation, and metamorphism, realistic limits to hydrocarbon occurrences in the Appalachians may be defined. Additional consideration of thermal gradients and present depths to possible sedimentary rocks in the footwall beneath the Blue Ridge—Piedmont overthrust indicates that hydrocarbon stability is unlikely beneath much of it today.
Radio Astronomy with the Very Large Array
Authors: Hjellming R. M. , Bignell R. C.
Published: October 2006

The construction of the Very Large Array of radio telescopes has been completed, and this new research instrument is now being used to make radio images of astronomical objects with a resolution comparable to or better than that of ground-based optical telescopes. The role of the Very Large Array in current and future research is discussed both in principle and in terms of a sample of observing projects.
Activation of Polyphosphoinositide Hydrolysis in T Cells by H-2 Alloantigen But Not MLS Determinants
Authors: O'Rourke Anne M. , Mescher Matthew F. , Webb Susan R.
Published: October 2006

Murine minor lymphocyte-stimulating (Mls) determinants are cell surface antigens that stimulate strong primary T cell responses; the responding T cells display restricted T cell receptor (TCR) V
β
gene usage. Interaction of T cells with mitogens or major histocompatibility complex (MHC) antigens activated the polyphosphoinositide (PI) signaling pathway, but this pathway was not triggered by Mls recognition. However, interleukin-2 (IL-2) secretion and proliferation to all three stimuli were comparable. Thus, although recognition of both allo-H-2 and Mls determinants is thought to be mediated by the TCR, these antigens appear to elicit biochemically distinct signal transduction pathways.
Natural and Synthetic Allatotoxins: Suicide Substrates for Juvenile Hormone Biosynthesis
Authors: Bowers W. S. , Evans P. H. , Marsella P. A. , Soderlund D. M. , Bettarini F.
Published: October 2006

Cytotoxic agents with antijuvenile hormone activity in insects have been discovered. Their mechanism of action may involve an oxidative bioactivation into a reactive quinone methide.
Carbonate Dissolution and Sedimentation on the Mid-Atlantic Continental Margin
Authors: Balsam William L.
Published: October 2006

The calcium carbonate content was determined for core tops from two transects on the upper slope to lower rise on the mid-Atlantic continental margin. Carbonate content in the sediment increases from ∼ 5 percent (by weight) on the upper slope to more than 30 percent on the upper rise. A zone of low-carbonate content extends from 3000 to 4400 meters. Below 4400 meters, the percent carbonate increases. An examination of dissolution indices in these core tops indicates that the low-carbonate zone is associated with intense dissolution. Below 4400 meters, dissolution decreases and carbonate is well preserved. The decrease in dissolution occurs where the high-velocity core of the Western Boundary Undercurrent is first encountered.
How the Law of the Sea Treaty Will Affect U.S. Marine Science
Authors: Ross David A. , Knauss John A.
Published: October 2006

The Law of the Sea treaty will clearly affect the way U.S. marine scientists operate in about 40 percent of the ocean. The matter will be made even more complex by the apparent intention of the Reagan Administration to remain outside the treaty.
Scaling in Tensile "Skeletons": Structures with Scale-Independent Length Dimensions
Authors: Peterson Jane A. , Benson John A. , Ngai Margaret , Morin James , Ow Cathy
Published: October 2006

Skeletal structures that resist only tensile forces can scale differently than compression resisting structures that fail in bending or buckling. The tensile structures examined scalelike simple ropes: length and diameter of the structure are not correlated, and in three of four cases, length is independent of scale or load, but diameter is dependent on scale. These relations suggest that similarity in stress rather than strain, or deformational behavior, is the basis for mechanical adaptation in the gross dimensions of these tensile structures.
Earthquake Dating: An Application of Carbon-14 Atom Counting
Authors: Tucker A. B. , Woefli W. , Bonani G. , Suter M.
Published: October 2006

Milligram-sized specimens of detrital charcoal from soil layers associated with prehistoric earthquakes on the Wasatch fault in Utah have been dated by direct atom counting of carbon-14 with a tandem Van de Graaff accelerator. The measured ratios of carbon-14 to carbon-12 correspond to ages of 7800, 8800, and 9000 years with uncertainties of ± 600 years.
An RNA Polymerase II Transcription Factor Shares Functional Properties with
Escherichia coli
σ
70
Authors: Conaway Joan Weliky , Conaway Ronald C.
Published: October 2006

A mammalian transcription factor, which, along with other factors, is essential for accurate initiation of transcription from promoters by RNA polymerase II, has been found to regulate the interaction of polymerase and DNA. This factor, designated βγ, drastically reduces the affinity of RNA polymerase II for free DNA containing either promoter or nonpromoter sequences. In this respect, βγ functions as does the bacterial transcription initiation factor σ
70
, which expedites the binding of
Escherichia coli
RNA polymerase to promoters in part by accelerating dissociation of the polymerase from nonpromoter sites in DNA.
Evolutionary Relatedness of Viper and Primate Endogenous Retroviruses
Authors: Andersen Philip R. , Barbacid Mariano , Tronick Steven R. , Clark H. Fred , Aaronson Stuart A.
Published: October 2006

A retrovirus previously isolated from a tumored Russell's viper is shown by molecular hybridization to be an endogenous virus of this reptilian species. Radio-immunologic techniques revealed that the viper retrovirus is immunologically and, hence, evolutionarily related to endogenous type D retroviruses of Old World primates. These findings extend the number of vertebrate classes possessing endogenous retroviruses and suggest that type D retroviruses may even be more widely distributed in nature than type C retroviruses.
Plant Chimeras Used to Establish de novo Origin of Shoots
Authors: Norris R. , Smith R. H. , Vaughn K. C.
Published: October 2006

When African violet leaf explants are cultured in vitro, buds and shoots develop directly from the upper leaf surfaces. Three developmentally different African violet chimeras were cultured, and in each case adventitious shoots that developed into plants had the parent chimera pattern. A multicellular origin of the adventitious buds accounts for these results.
Crystallization and X-ray Analysis of Stemphyloxin I, a Phytotoxin from
Stemphylium botryosum
Authors: Barash Isaac , Manulis Shulamit , Kashman Yoel , Springer James P. , Chen Marie H. M. , Clardy Jon , Strobel Gary A.
Published: October 2006

Certain isolates of the plant-pathogenic fungus
Stemphylium botryosum
produce a phytotoxin, stemphyloxin I. This toxin (C
21
H
34
O
6
) was crystallized and its structure was determined by x-ray crystallography to be a β-ketoaldehyde
trans
-Decalin. This compound is a highly unusual natural product. Iron (Fe
3+
) controls production of toxin by this fungus. Furthermore, iron reacts with the toxin to yield a colored product which aids in its detection on chromatograms and in its quantitative estimation by colorimetry.
Federal R & D and Industrial Policy
Authors: Keyworth G. A.
Published: October 2006

Long-term U.S. economic growth requires better use of R & D resources and closer interaction of the academic, government, and industrial research communities. The federal government has proposed to increase support for university research as a key means of addressing national needs for new knowledge in fields important to industrial development and for training of technical personnel. But continuing growth in support for basic research depends on how well the science community can agree on what research investments will have the greatest impact in producing new knowledge.
Localization of Wheat Germ Agglutinin—Like Lectins in Various Species of the Gramineae
Authors: Mishkind Michael L. , Palevitz Barry A. , Raikhel Natasha V. , Keegstra Kenneth
Published: October 2006

Antigenically similar chitin-binding lectins are present in the embryos of wheat, barley, and rye, members of the Triticeae tribe of the grass family (Gramineae). However, the lectins display different localization patterns in these embryos. Lectin is absent from the coleoptile of barley but is present in the outer surface cells of this organ in wheat and in both inner and outer surface cells of rye coleoptiles. All three cereals contain lectin at the periphery of embryonic roots. Similar lectins were not detected in oats and pearl millet, members of other tribes of the Gramineae. Rice, a species only distantly related to wheat, contains a lectin that is antigenically similar to the other cereal lectins and located at the periphery of embryonic roots and throughout the coleoptile.
An Episode of Steep Geomagnetic Inclination 120,000 Years Ago
Authors: Verosub Kenneth L.
Published: October 2006

The mean inclinations of three sections of 120,000-year-old fine-grained sediments from northern California range from 62° to 66°. These inclinations are significantly steeper than the inclination of the geocentric axial dipole at this site. Because these sediments have probably recorded an actual episode of steep inclination lasting several thousand years, they provide new insights into the significance of mean inclinations shallower than the geocentric axial dipole. Such inclinations are characteristic of fine-grained sediments younger than 35,000 years. The results raise questions about the time-averaged geomagnetic field and about the determination of plate motions from paleomagnetic data.
The Possible Link Between Net Surface Heating and El Niño
Authors: Weare Bryan C.
Published: October 2006

Three diagnostic analyses are described which strongly suggest the importance of local net surface heating in the life history of the large-scale, air-sea phenomenon centered in the eastern tropical Pacific Ocean, commonly called El Niño. These analyses rely upon monthly marine weather summaries for the period 1957 to 1976. In the first, correlations and coherence spectra were calculated which show a strong link between the net surface heat flux and sea-surface temperature variations over the eastern equatorial Pacific. The second analysis, also based upon the use of coherence spectra, indicates a sea temperature precursor in the eastern ocean near 25°S which precedes sea temperature changes near the El Niño focus near 5°S. Since the link between the two regions would require ocean advective velocities that appear to be unreasonably large, this analysis also suggests the importance of atmospheric forcing through the surface heat flux. In the third analysis a proxy variable is described that seems to be a reasonable indicator of the overall effect of ocean dynamics on the temperature of the El Niño core region. A composite analysis of the four El Niño events of 1957, 1965, 1972, and 1976 suggests that local surface heating is important during the early part of an event, whereas dynamical factors dominate later.
Effect of Fluorine Substitution on the Agonist Specificity of Norepinephrine
Authors: Cantacuzene Daniele , Kirk Kenneth L. , McCulloh David H. , Creveling Cyrus R.
Published: October 2006

Substitution of fluorine for hydrogen in position 2, 5, or 6 of the aromatic ring of norepinephrine markedly alters the α- and β-adrenergic agonist properties of norepinephrine. The 6-fluoro isomer is an α-adrenergic agonist with virtually no β agonist activity, while the 2-fluoro isomer is a β-adrenergic agonist with little α activity. The 5-fluoro isomer is equipotent with norepinephrine as an α agonist and significantly more potent as a β agonist. The possible physiochemical basis for these differences is discussed.
6-Hydroxydopamine Potentiates Acute Herpes Simplex Virus Infection of the Superior Cervical Ganglion in Mice
Authors: Price Richard W.
Published: October 2006

Treatment of mice with 6-hydroxydopamine increased herpes simplex virus replication in the superior cervical ganglion while it decreased the subsequent prevalence of latent infection. Preganglionic neurectomy failed to block this effect. These observations suggest that intrinsic neural events modify the outcome of viral infections of the nervous system.
Nitrous Oxide Production in Nearshore Marine Sediments
Authors: Seitzinger Sybil P. , Pilson Michael E. Q. , Nixon Scott W.
Published: October 2006

Coastal marine sediments are shown to be a net source of nitrous oxide. The rates of nitrous oxide flux from sediments in Narragansett Bay, Rhode Island, ranged from 20 to more than 900 nanomoles per square meter per hour. Sediments from a eutrophic area had higher rates of net nitrous oxide production than sediments from relatively unpolluted sites. The benthic nitrous oxide source exceeds the nitrous oxide source to the bay from sewage treatment plant effluent.
Scientists and Congress
Authors: Gonzalez Henry B.
Published: October 2006

Scientists are urged to make their views known to members of Congress. To be effectively heard, they should establish personal contact with their congressmen and senators and their staff. Communication should be frequent, personal, and carefully focused. In the last 2½ years, federal funding of scientific research has been severely cut back, while military research funding has been increased. The selection process for funding research is being politicized. Scientists should concern themselves with what is happening politically because the quality of American scientific research is being threatened.
Cyclic AMP Receptor Triggers Nuclear Protein Phosphorylation in a Hormone-Dependent Mammary Tumor Cell-free System
Authors: Cho-Chung Yoon Sang , Archibald David , Clair Timothy
Published: October 2006

Adenosine 3′,5′-monophosphate (cyclic AMP) receptor protein of 56,000 daltons increases markedly in mammary tumors induced by 7,12-dimethylbenz[
a
]anthracene (DMBA) after incubation of tumor slices with cyclic AMP, benzamidine, and arginine. Incubation of cytosol from these tumor slices with nuclei from unincubated tumors results in nuclear uptake of the 56,000-dalton cyclic AMP receptor and in phosphorylation of the 76,000-dalton nuclear protein. Binding of the 56,000-dalton receptor and phosphorylation of the 76,000-dalton protein also occur in DMBA tumor nuclei when protein kinase type II of bovine heart is used. The results suggest that cyclic AMP receptor is involved in the nuclear events of a hormone-dependent mammary tumor.
Isotopic Stack: Measurement of Heavy Cosmic Rays
Authors: Beaujean R. , Schmidt M. , Enge W. , Siegmon G. , Krause J. , Fischer E.
Published: October 2006

A stack of plastic nuclear track detectors was exposed to heavy cosmic rays on the pallet of Spacelab 1. Some layers of the stack were rotated with respect to the main stack to determine the arrival time of the particles. After return of the stack the latent particle tracks are revealed by chemical etching. Under the optical microscope the charge, mass, energy, and impact direction of the particles can be deduced from the track geometry.
Acid Rain: Ionic Correlations in the Eastern United States, 1980-1981
Authors: Gorham Eville , Martin Frank B. , Litzau Jack T.
Published: October 2006

Hydrogen ions in precipitation are correlated much more closely with sulfate than with nitrate, whereas ammonium ions are correlated more closely with nitrate than with sulfate. Target loadings of 14 to 16 kilograms of wet sulfate deposition per hectare per year, instead of 20 as suggested hitherto, are probably necessary to produce average
p
H values of 4.6 to 4.7, the approximate boundary levels for damage to aquatic ecosystems. Cluster analysis reveals that there are three linked groups of ions related to air pollution, agriculture, and sea spray.
Lunar Sample 14425: Characterization and Resemblance to High-Magnesium Microtektites
Authors: O'Keefe J. A. , Glass B. P.
Published: October 2006

Measurements by energy-dispersive x-ray analysis of the surface of lunar sample 14425, a large glass bead, yield a noritic composition enriched in aluminum and magnesium and, as compared with other norites, depleted in iron and especially calcium. The sample is close in composition to the most basic microtektites. Spherical inclusions of nickel-iron, flattened where they protrude, are found to be enriched in sulfur and phosphorus, at least at the surface. The inclusions form approximately 1 percent of the volume.
Mechanism of Aeration in Rice
Authors: Raskin Ilya , Kende Hans
Published: October 2006

Mass flow of air to the submerged parts of the plant constitutes the major mechanism of aeration in partially submerged rice. It is proposed that the flow of air results from reduction of pressure in the air-conducting system of the plant caused by consumption of oxygen and solubilization of respiratory carbon dioxide in the surrounding water.
Periodicity in Tree Rings from the Corn Belt
Authors: Meko D. M. , Stockton C. W. , Blasing T. J.
Published: October 2006

Previous tree-ring studies indicated that the total area affected by drought in the western United States has rhythmically expanded and contracted over the past 300 years, with a period near the 18.6-year lunar nodal and 22-year double-sunspot cycles. Recently collected tree-ring data from the U.S. Corn Belt for the years 1680 to 1980 were examined for evidence of either of these cycles on a regional scale. Spectral analysis indicated no periodicity in the eastern part of the Corn Belt, but a significant 18.33-year period in the western part. The period length changed from 17.60 to 20.95 years between the first 150 years and the last 151. High-resolution frequency analysis showed that the structure of the 18.33-year spectral peak was complex, with contributions from several frequencies near both the lunar nodal and double-sunspot periods. A t-test of difference of means in reconstructed annual precipitation weakly corroborated a previous finding of an association between drought area and the phase of the double-sunspot cycle. Both the high-resolution frequency analysis and the t-test results indicate that the periodic component of drought near 20 years is too weak and irregular to be of use in drought forecasting for the Corn Belt.
Soil Radon and Elemental Mercury Distribution and Relation to Magmatic Resurgence at Long Valley Caldera
Authors: Williams Stanley N.
Published: October 2006

The response of a large geothermal system to magmatic resurgence was analyzed by a survey of soil gas radon and elemental mercury at 600 sites in the silicic Long Valley Caldera, California. The broad geochemical anomaly over the caldera has superimposed on it a small zone of pronounced radon enrichment and mercury depletion coincident with the surface projection of a postulated dike of rising magma. Soil gas geochemistry studies can complement traditional geophysical and geodetical methods in the evaluation of potential volcanic eruption hazards.
Infrared Speckle Observations of Io: An Eruption in the Loki Region
Authors: Howell R. R. , McGinn M. T.
Published: October 2006

Speckle observations of Jupiter's satellite Io at a wavelength of 5 micrometers during July 1984 resolved the disk and showed emission from a hot spot in the Loki region. The hot spot contributed a flux approximately equal to 60 percent of that from the disk. Images reconstructed by means of the Knox-Thompson algorithm showed the spot moving across the disk as the satellite rotated. It was located at 301° ± 6° west longitude, 10° ± 6° north latitude, and had a radiance of (2.96 ± 0.54) × 10
22
ergs sec
-1
cm
-1
sr
-1
/
A
where
A
is the area of the spot. For an assumed temperature of 400 K, the area of the source would be 11,400 square kilometers. An active "lava lake" similar to that seen by Voyager may be the source of the infrared emission.
Transfer of
Agrobacterium
DNA to Plants Requires a T-DNA Border But Not the
vir
E Locus
Authors: Gardner Richard C. , Knauf Vic C.
Published: October 2006

Agrobacterium tumefaciens
induces tumors in plants by transferring and integrating oncogenes (T-DNA) into the chromosomes of host plant cells.
Agrobacterium
strains were used to transfer complementary DNA copies of a potato spindle tuber viroid (PSTV) to plant cells at a wound site on tomato plant stems. Subsequently, infectious viroid RNA was found in the leaves of these plants, indicating systemic PSTV infection. This process utilized the T-DNA transfer mechanisms of
Agrobacterium
since PSTV infection required most virulence genes (
vir
) as well as one of the DNA sequences that flank either side of the
Agrobacterium
T-DNA. However, transfer still occurred from
vir
E mutants of
Agrobacterium
, strains that fail to induce tumors even though a completely functional T-DNA is present. The
vir
E gene seems to be directly involved in the integration of foreign DNA into plant chromosomes.
Thymic Epithelium Tolerizes for Histocompatibility Antigens
Authors: Salaün Josselyne , Bandeira Antonio , Khazaal Ibrahim , Calman Françoise , Coltey Monique , Coutinho Antonio , Le Douarin Nicole M.
Published: October 2006

The role of thymic epithelium in the establishment of tissue tolerance was analyzed with a murine chimeric system. All T cells differentiated from birth onward in a thymus comprising allogeneic epithelium and syngeneic hematopoietic cells. Embryonic thymic rudiments that contained no hematopoietic cells from C3H (H-2
k
) donors were grafted to newborn athymic (nude) BALB/c (H-2
d
) mice. Chimeras that had normal T cell numbers and function rejected third-party skin grafts, but permanently accepted grafts syngeneic to the thymic epithelium. In vitro functional assays did not always correlate with the state of tolerance in vivo. Thus, pure thymic epithelium induces tolerance to histocompatibility antigens.
Predicting New Solids and Superconductors
Authors: Cohen Marvin L.
Published: October 2006

It is now possible to start with a simple model of a solid composed of atomic cores and itinerant valence electrons and compute the total energy for a given structural arrangement of atoms with enough precision to predict the existence of new solids and their properties. The application of the model based on the pseudopotential method is described with silicon chosen as a prototype material. With only information about the constituent atoms, the electronic, structural, vibrational, and even superconducting properties of solids can be calculated from first principles. The successful predictions of superconductivity in highly condensed hexagonal silicon and the existence of new high-pressure semiconductor phases are highlighted. A discussion is presented of the use of the method to discover new stable or metastable solids at high pressures.
Age of the Earliest African Anthropoids
Authors: Fleagle John G. , Bown Thomas M. , Obradovich John D. , Simons Elwyn L.
Published: October 2006

The earliest fossil record of African anthropoid primates (monkeys and apes) comes from the Jebel Qatrani Formation in the Fayum depression of Egypt. Reevaluation of both geologic and faunal evidence indicates that this formation was deposited in the early part of the Oligocene Epoch, more than 31 million years ago, earlier than previous estimates. The great antiquity of the fossil higher primates from Egypt accords well with their primitive morphology compared with later Old World higher primates. Thus, the anthropoid primates and hystricomorph rodents from Fayum are also considerably older than the earliest higher primates and rodents from South America.
New Production Techniques for Alberta Oil Sands
Authors: Carrigy Maurice A.
Published: October 2006

Low world oil prices represent a serious threat to expanded commercial development of the Canadian oil sands in the near term, as they do to all of the higher cost alternatives to crude oil such as oil shales and coal liquefaction. Nonetheless, research and field testing of new technology for production of oil from oil sands are being pursued by industry and government in Alberta. New production technology is being developed in Canada to produce synthetic oil from the vast resources of bitumen trapped in the oil sands and bituminous carbonates of northern Alberta. This technology includes improved methods of mining, extraction, and upgrading of bitumen from near-surface deposits as well as new drilling and production techniques for thermal production of bitumen from the more deeply buried reservoirs. Of particular interest are the cluster drilling methods designed to reduce surface disturbance and the techniques for horizontal drilling of wells from underground tunnels to increase the contact of injection fluids with the reservoir.
Reversal of Creatine Kinase Translational Repression by 3′ Untranslated Sequences
Authors: Ch'ng J. Lai C. , Shoemaker David L. , Schimmel Paul , Holmes Edward W.
Published: October 2006

A subline of U937 cells (U937D) was obtained in which creatine kinase B (CK-B) messenger RNA was present and bound to ribosomes, but CK activity was undetectable. Transformation of U937D cells with retrovirus vectors that contain the 3′ untranslated region (3′ UTR) of CK-B messenger RNA exhibited CK activity with no change in abundance of CK-B mRNA. The 3′ UTR formed a complex in vitro with a component of S100 extracts from wild-type cells. This binding activity was not detectable in S100 extracts from cells that expressed CK activity after transformation with the 3′ UTR-containing vector. These results suggest that translation of CK-B is repressed by binding of a soluble factor or factors to the 3′ UTR.
Chaotic Bursts in Nonlinear Dynamical Systems
Authors: Devaney Robert L.
Published: October 2006

Several elementary nonlinear dynamical systems in the complex plane may provide models for abrupt transitions to chaotic dynamics. In particular, the complex trigonometric and exponential functions explode into chaos as a parameter is varied. Numerical evidence is presented that supports the contention that these explosions occur whenever an elementary bifurcation occurs. This numerical evidence, in the form of computer graphics, is an example of the increasing importance of experimentation in mathematics research.
Solar Neutrinos: Questions and Hypotheses
Authors: Weneser Joseph , Friedlander Gerhart
Published: October 2006

The "solar neutrino puzzle" has been a challenge for almost 20 years, posing broad and fundamental questions about astrophysics and neutrino properties. This article sketches some of the ideas that have been put forward to solve the problem. These ideas can be grouped into two main classes: those involving changes in the standard solar model or in the basic nuclear reaction data, and those that attribute the puzzle to as yet unobserved properties of the neutrinos.
Release of Juvenile Water on Mars: Estimated Amounts and Timing Associated with Volcanism
Authors: Greeley Ronald
Published: October 2006

The amount of water released on Mars in association with volcanism is estimated to equal a layer 46 meters deep over the entire planet. Most of this water was released in the first 2 billion years of martian history. The estimate is based on mapping the volcanic materials and by inferring the volatile content of the lavas. Water from other sources, such as plutonic activity and cometary contributions, is not included in the estimate.
Detection of Uranium from Cosmos-1402 in the Stratosphere
Authors: Leifer Robert , Juzdan Z. Russell , Kelly W. R. , Fassett J. D. , Eberhardt K. R.
Published: October 2006

The nuclear reactor from the Soviet radar reconnaissance satellite, Cosmos-1402, reentered the earth's atmosphere on 7 February 1983 and disintegrated over the South Atlantic Ocean. The reactor was powered by approximately 50 kilograms of uranium-235 (
235
U). In an effort to determine the fate of the reactor core, a series of aerosol samples were collected at altitudes between 27 and 36 kilometers in the Northern Hemisphere approximately 1.1 years later by high-altitude balloons. At an altitude of 36 kilometers a 53 ± 20 percent excess in the
235
U concentration was measured. The total excess of
235
U in the stratosphere was calculated to be 44 ± 15 kilograms.
When Will a Pulsar in Supernova 1987a Be Seen?
Authors: Michel F. Curtis , Kennel C. F. , Fowler William A.
Published: October 2006

The means by which a pulsar might be detected in the remnant of supernova 1987a in the Large Magelanic Cloud is examined. One possibility is that the slower-than-radioactive decay typically seen in the type II light curves is itself the sign of powering by the underlying pulsar, with the decline representing not the spinning down of the pulsar but rather the declining nebular opacity that would allow increasing amounts of the energy to escape as gamma rays. The test of this hypothesis (if the supernova conforms to type II expectations) would be to look for the "missing" energy in the form of those gamma rays that escape from the remnant instead of powering it.
Spectrophotometry of Pluto-Charon Mutual Events: Individual Spectra of Pluto and Charon
Authors: Sawyer S. R. , Barker E. S. , Cochran A. L. , Cochran W. D.
Published: October 2006

Time-resolved spectra of the 3 March and 4 April 1987 mutual events of Pluto and its satellite Charon were obtained with spectral coverage from 5,500 to 10,000 angstroms with 25 angstrom spectral resolution. Since both events were total occultations of Charon by Pluto, spectra were obtained of the anti-Charon—facing hemisphere of Pluto, with no contribution from Charon during totality. On 4 April, a combined spectrum of Pluto and Charon immediately before first contact was also obtained. The spectrum of the Pluto-facing hemisphere of Charon was extracted by differencing the pre-event and totality spectra. The spectra were reduced to reflectances by ratioing them to spectra of solar analog stars. Charon has a featureless reflectance spectrum, with no evidence of methane absorption. Charon's reflectance appears neutral in color and corresponds to a geometric albedo of ∼0.37 at 6000 angstroms. The Pluto reflectance spectrum displays methane absorption bands at 7300, 7900, 8400, 8600, and 8900 angstroms and is red in color, with a geometric albedo of ∼0.56 at 6000 angstroms. The signal-to-noise ratios of the eclipse spectra were not high enough to unambiguously identify the weaker methane band at 6200 angstroms.
Horizontal Plate Motion: A Key Allocyclic Factor in the Evolution of the Great Barrier Reef
Authors: Davies P. J. , Symonds P. A. , Feary D. A. , Pigram C. J.
Published: October 2006

The Great Barrier Reef complex of northeastern Australia thins dramatically and becomes younger from north to south. These variations are a consequence of the Cenozoic northward movement of the Indian-Australian plate. The temperate climatic conditions that applied off northeast Australia during the early Tertiary were progressively replaced by tropical conditions. The present-day south-to-north facies distribution along the eastern Australian continental margin mimics the Cenozoic vertical facies sequence through the northern part of the Great Barrier Reef region.
Oligomerization of Intervening Sequence RNA Molecules in the Absence of Proteins
Authors: Zaug Arthur J. , Cech Thomas R.
Published: October 2006

The intervening sequence RNA excised from the ribosomal RNA precursor of
Tetrahymena
forms linear and circular oligomers when exposed to a heating-cooling treatment in vitro. The reactions require no protein or external energy source. Oligomerization is different from other self-catalyzed reactions of the intervening sequence RNA in that it involves intermolecular rather than intramolecular recombination, producing RNA molecules that are substantially larger than the original. The observation that RNA molecules can catalyze their own oligomerization has possible implications for the evolution of chromosomes and for the replicative cycle of plant viroids and virus-associated RNA's.