bluuebunny/crossref_metadata_2025 huggingface dataset:
Calcium-Promoted Protein Phosphorylation in Plants
Authors: Veluthambi K. , Poovaiah B. W.
Published: October 2006

Phosphorylation of several polypeptides in corn coleoptiles was promoted by adding calcium. Chlorpromazine, a calmodulin inhibitor, reduced calcium-promoted phosphorylation, suggesting that the phosphorylation was modulated by calmodulin. This is evidence for the role of calcium in protein phosphorylation in plants and could serve as an experimental approach to understanding the molecular mechanism by which calcium modulates various physiological processes in plants.
Thickness of Saturn's Rings Inferred from Voyager 1 Observations of Microwave Scatter
Authors: Zebker H. A. , Tyler G. L.
Published: October 2006

Earth-based telescopic observations indicate that Saturn's rings are about 1 kilometer thick, while spacecraft measurements and theoretical considerations give an upper bound of about 100 meters. Analysis of a shielding effect present in radio occultation provides a sensitive new measure of the ring thickness. On the basis of this effect, Voyager 1 microwave measurements of near-forward scatter imply a thickness ranging from less than 10 meters in ring C to about 20 and 50 meters in the Cassini division and ring A, respectively. Monolayer models do not fit the observations in the latter two regions. The discrepancy between the Earth-based and spacecraft measurements may be due to warps in the ring plane or effects of tenuous material outside the primary ring system.
Communications Satellites: Countdown for INTELSAT VI
Authors: Pollack L. , Weiss H.
Published: October 2006

Since the formation of COMSAT 20 years ago, the number of international telephone circuits made through satellites has grown 400 times and the cost of a telephone call has decreased by 12,000 percent. Worldwide communications linking 109 nations are achieved with 14 satellites in earth-synchronous orbit. Advances in microwave technology have expanded the transmission bandwidth per satellite from 50 to more than 3000 megahertz. Improvements in solar cell, battery, stationkeeping, and microwave amplification technology have increased satellite lifetime from 1.5 years to 10. The sixth generation of INTELSAT satellites, now being manufactured, will be introduced into the system in 1986, and each satellite will carry more than 40,000 telephone channels plus two television programs. The next generation of satellites, now under design for expanded capacity, will be needed by the middle 1990's to meet the traffic demand. These satellites are likely to add new frequencies (20 and 30 gigahertz), onboard signal processing and switching, and more bandwidth-efficient modulation, to achieve larger communication capacity at each orbital location.
Time-Resolved X-ray Absorption Spectroscopy of Carbon Monoxide-Myoglobin Recombination After Laser Photolysis
Authors: Mills D. M. , Lewis A. , Harootunian A. , Huang J. , Smith B.
Published: October 2006

Results are presented for the first time-resolved x-ray absorption measurements with a time resolution of 300 microseconds on a dynamically evolving chemical system. By synchronizing a neodymium:yttrium-aluminum-garnet pulsed laser with the bursts of x-rays emitted from the Cornell High Energy Synchrotron Source, it was possible to monitor at room temperature the recombination of carbon monoxide with myoglobin after laser photolysis. Changes in the pre-edge structure and in the position of the iron edge of this protein were detected as a function of time.
Hydrogen-Evolving Solar Cells
Authors: Heller Adam
Published: October 2006

Sunlight is directly converted to chemical energy in hydrogen-evolving photoelectrochemical cells with semiconductor electrodes. Their Gibbs free energy efficiency of solar-to-hydrogen conversion, 13.3 percent, exceeds the solar-to-fuel conversion efficiency of green plants and approaches the solar-to-electrical conversion efficiency of the best
p-n
junction cells. In hydrogen-evolving photoelectrodes, electron-hole pairs photogenerated in the semiconductor are separated at electrical microcontacts between the semiconductor and group VIII metal catalyst islands. Conversion is efficient when the island diameters are small relative to the wavelengths of sunlight exciting the semiconductor; when the island spacings are smaller than the diffusion length of electrons at the semiconductor surface; when the height of the potential energy barriers that separate the photogenerated electrons from holes at the semiconductor surface is raised by hydrogen alloying of the islands; when radiationless recombination of electron-hole pairs at the semiconductor-solution interface between the islands is suppressed by controlling the semiconductor surface chemistry; and when the semiconductor has an appropriate band gap (1.0 to 1.8 electron volts) for efficient solar conversion.
Mesodermal Control of Neural Cell Identity: Floor Plate Induction by the Notochord
Authors: Placzek Marysia , Tessier-Lavigne Marc , Yamada Toshiya , Jessell Thomas , Dodd Jane
Published: October 2006

The floor plate is a specialized group of midline neuroepithelial cells that appears to regulate cell differentiation and axonal growth in the developing vertebrate nervous system. A floor plate-specific chemoattractant was used as a marker to examine the role of the notochord in avian floor plate development. Expression of this chemoattractant in lateral cells of the neural plate and neural tube was induced by an ectopic notochord, and midline neural tube cells did not express the chemoattractant after removal of the notochord early in development. These results provide evidence that a local signal from the notochord induces the functional properties of the floor plate.
Detectability of Supernova Neutrinos with an Existing Proton Decay Detector
Authors: Losecco J. M.
Published: October 2006

The 8000-ton water IMB nucleon decay detector has good sensitivity to the neutrino burst associated with the collapse of stars. It is particularly sensitive to the ν̅
e
charged current interactions with protons but can also record other neutrino interactions through ν
e
scattering. Signal, noise, physics objectives, and detector modifications that would enhance burst detection are discussed. The objectives include astrophysical questions about the pulse structure and power. It also may be possible with a distant source to study neutrino masses and neutrino oscillations.
Early Eocene Vertebrates from Baja California: Evidence for Intracontinental Age Correlations
Authors: Flynn John J. , Novacek Michael J.
Published: October 2006

Newly discovered fossils support a Wasatchian (early Eocene) age for the Punta Prieta vertebrate fauna of Baja California and reveal the utility of land mammal ages on a continental scale. Dispersal scenarios for late Paleocene and early Eocene vertebrates usually invoke heterochrony for similar, but geographically separated, faunas or taxa. Such heterochrony is not supported by independent geochronologies or adequate geographic samples.
Conservation of Rice Genetic Resources: Luxury or Necessity?
Authors: Chang T. T.
Published: October 2006

There is remarkably rich diversity in the cultivated rices and their wild relatives. Substantial segments of the diverse germplasm have been collected and conserved during the past two decades by national, regional, and international research centers. Multidisciplinary and interinstitutional evaluation and use have drawn substantial rewards. However, nations in the developing world that grow and consume rice still face enormous challenges to meet the continuous growth of the human population. Further conservation efforts and improved preservation measures are needed to provide security for the irreplaceable rice germplasm. Modest inputs into conservation programs are highly justified by multibillion dollar returns from the improved varieties in the past two decades.
Drosophila
Males Contribute to Oogenesis in a Multiple Mating Species
Authors: Markow Therese A. , Ankney Paul F.
Published: October 2006

Two species of
Drosophila
that differ in their ecology and mating systems have been compared with respect to male contribution to the somatic tissues and developing oocytes of females. In the species
Drosophila mojavensis
females remate daily, exhibit a copulatory plug, and have been shown to obtain a contribution from the male ejaculate. In contrast,
Drosophila melanogaster
males do not contribute to females. Female
Drosophila melanogaster
do not remate as frequently as
Drosophila mojavensis
females nor is a copulatory plug formed.
A Candidate Magnetic Sense Organ in the Yellowfin Tuna,
Thunnus albacares
Authors: Walker Michael M. , Kirschvink Joseph L. , Chang Shih-Bin R. , Dizon Andrew E.
Published: October 2006

Single-domain magnetite crystals have been isolated and characterized from tissue located in a sinus within the dermethmoid bone of the skull of the yellowfin tuna,
Thunnus albacares
. Their chemical composition, narrow size distribution, and distinctive crystal morphology indicate that these crystals are biochemical precipitates. Experiments on the interaction between particles reveal the organization of the particles in situ and suggest a possible form for candidate magnetoreceptor organelles. The consistent localization of such particles with similar arrangement within the dermethmoids of this and other pelagic fishes suggests that the ethmoid region is a possible location for a vertebrate magnetic sense organ.
Starvation-Induced Decreased Sensitivity of Resting Metabolic Rate to Triiodothyronine
Authors: Wimpfheimer C. , Saville E. , Voirol M. J. , Danforth E. , Burger A. G.
Published: October 2006

The decrease in resting oxygen consumption induced by starvation was found to occur not only in euthyroid rats but also in hypothyroid and even in hypothyroid animals treated with triiodothyronine. Furthermore, the effectiveness of triiodothyronine was decreased when given to starved hypothyroid animals.
Protection of Plant Varieties and Parts as Intellectual Property
Authors: Williams Sidney B.
Published: October 2006

In view of the Supreme Court decision in
Chakrabarty v. Diamond, Commissioner of Patents and Trademarks
, it is possible that plant varieties can be protected under three different U.S. statutes: the Plant Variety Protection Act, the Plant Patent Law, and the General Patent Law. The Plant Variety Protection Act protects varieties that are reproduced by seed, whereas the Plant Patent Law protects varieties reproduced asexually. Varieties, irrespective of how they are reproduced, could be patentable under the General Patent Statute. It is not clear whether parts of plants can be protected by grants under the Plant Patent Law or Plant Variety Protection Act and it is possible that they will be best protected under the General Patent Statute and by maintaining them as trade secrets. Only time will show whether the existing statutes are sufficient to provide both guidance and adequate protection or whether changes in the law will be required.
Sample Performance of the Grille Spectrometer
Authors: Lemaitre M.-P. , Laurent J. , Besson J. , Girard A. , Lippens C. , Muller C. , Vercheval J. , Ackerman M.
Published: October 2006

The grille spectrometer observed the setting and rising sun 18 times during the Spacelab 1 mission. In addition to solar absorption lines, many of which had not been observed before, atmospheric spectral absorptions due to carbon monoxide and carbon dioxide were observed at heights tangent to the thermosphere (greater than 85 kilometers), and absorptions due to ozone, water, methane, and nitrous oxide were observed in the mesosphere (greater than 50 kilometers). The strongly coupled molecules NO-NO
2
and HCl-HF were observed as pairs in the stratosphere. Methane is presented as an example of the instrumental operations because of the characteristic aspect of the Q branch of its ν
3
band.
Very-Wide-Field Ultraviolet Sky Survey
Authors: Courtès G. , Viton M. , Sivan J. P.. , Decher R. , Gary A.
Published: October 2006

Very-wide-field photographs of the sky were taken on Spacelab 1 at 1650, 1930, and 2530 angstroms with a limiting magnitude of 9.3 at 1930 angstroms. A 1.2 by 2.4 kiloparsec ultraviolet extension of the Shapley wing of the Small Magellanic Cloud is seen in some of the photographs.
Mechanical Wounding Induces the Formation of Extensive Coated Membranes in Giant Algal Cells
Authors: O'Neil Rory M. , La Claire John W.
Published: October 2006

Mechanically wounding giant cells of
Boergesenia forbesii
induces the formation of bristle-coated, plasma-membrane invaginations (coated pits) and coated vesicles, easily providing a plentiful source of coated membranes in a clean cellular system unencumbered by other tissues. Contractions evoked by wounding partition the cytoplasm into hundreds of spherical protoplasts with approximately 40 percent less total plasma-membrane surface area than the original cell. Ferritin labeling and the appearance of numerous large coated pits and vesicles at the peak period of contraction indicate that these organelles play a role in extensive endocytosis of the plasma membrane.
Albumin and Australian Frogs: Molecular Data a Challenge to Speciation Model
Authors: Maxson Linda R. , Roberts J. Dale
Published: October 2006

Vertebrate speciation in the southwest of Australia has long been viewed as resulting from multiple invasions of eastern source stocks during the Pleistocene. Microcomplement fixation studies of serum albumin evolution in frogs of the genus
Heleioporus
provide the first hard data on age and phylogenetic relationships among species in this genus and lead to rejection of the multiple invasion model in favor of speciation occurring in Western Australia. The albumin molecular clock was used to estimate that the species divergences in this genus occurred between 4 million to 12 million years ago in the late Tertiary (Pliocene-Miocene), rather than in the Quaternary (the last 2 million years).
Networking in International Agricultural Research
Authors: Plucknett Donald L. , Smith Nigel J. H.
Published: October 2006

Informal and structured collaboration is becoming increasingly common in international agricultural research. A network approach to research generally reduces costs, minimizes duplication, and boosts efficiency. Collaborative teams, sometimes involving hundreds of scientists in dozens of countries, have been formed to tackle numerous constraints to boosting food production. Networks have been established to test crop germplasm over a broad range of environments, explore ways of boosting the efficiency of fertilizer use, upgrade disease resistance in livestock, and identify socioeconomic obstacles to improved agricultural output. The benefits of networking are especially valuable to countries with limited funds and scientific manpower.
Hail Detection with a Differential Reflectivity Radar
Authors: Bringi V. N. , Seliga Thomas A. , Aydin Kultegin
Published: October 2006

A major objective in the remote sensing of convective storms by radar is the clear and reliable differentiation between regions of hail and regions of rainfall. This report describes the application of the differential reflectivity (Z
DR
) radar technique to the problem of hail detection. The procedure is based on the markedly different polarization-dependent backscatter characteristics of rain and hail. Field experiments conducted in Colorado during the spring of 1983 provide significant evidence of hail detection with this new radar technique.
Phosphatidylinositol as a Component of the Ice Nucleating Site of
Pseudomonas syringae
and
Erwinia herbiola
Authors: Kozloff Lloyd M. , Lute Murl , Westaway David
Published: October 2006

Phosphatidylinositol has been identified as a major component of the ice nucleating site on the outer surface of two bacteria,
Pseudomonas syringae
and
Erwinia herbicola
. Plant lectins binding to inositol and a highly purified phosphatidylinositol-specific hydrolase (a C
II
lipase) inhibited or decreased the efficiency of the ice nucleating activity (INA) of both bacteria. Extracts of these two INA
+
bacteria had phosphatidylinositol synthase activity while extracts from related INA
-
Pseudomonas
or
Erwinia
strains had no detectable synthase activity. An
Escherichia coli
strain acquired phosphatidylinositol synthase activity when transformed to the INA
+
phenotype with recombinant plasmids containing fragments of
P. syringae
DNA.
Two-Million-Year Record of Deuterium Depletion in Great Basin Ground Waters
Authors: Winograd Isaac J. , Szabo Barney J. , Coplen Tyler B. , Riggs Alan C. , Kolesar Peter T.
Published: October 2006

Fluid inclusions in uranium series-dated calcitic veins from the southern Great Basin record a reduction of 40 per mil in the deuterium content of ground-water recharge during the Pleistocene. This variation is tentatively attributed to major uplift of the Sierra Nevada Range and the Transverse Ranges during this epoch with attendant increasing orographic depletion of deuterium from inland-bound Pacific storms.
Raman Microprobe Evidence for Lignin Orientation in the Cell Walls of Native Woody Tissue
Authors: Atalla Rajai H. , Agarwal Umesh P.
Published: October 2006

Raman microprobe spectra from the secondary wall of earlywood tissue from
Picea mariana
(black spruce) reveal evidence of the orientation of lignin relative to the plane of the cell wall. In most instances, the aromatic rings of the phenyl propane structural units are parallel to the plane of the cell-wall surface.
Toward A Coherent Theory of Chemisorption
Authors: Shustorovich Evgeny , Baetzold Roger C.
Published: October 2006

Studies of chemisorption phenomena, the cornerstone of heterogeneous catalysis, have become the central part of contemporary surface science. As a result of the great variety of the available experimental techniques, a backlog of information, some of which conflicts with current theoretical constructs, has accumulated. New models that combine analytical and computational facets have now begun to appear, revealing intrinsic relations among seemingly disparate chemisorption phenomena. Among the major findings are (i) the crucial role of antibonding adsorbate orbitals in bond activation and in the heat of chemisorption, (ii) adsorbate-induced surface polarization leading to a decrease of the metal work function and to an increase of the surface core binding energy, and (iii) important differences between atomic and molecular adsorbate modes of bonding and surface migration.
Margin to Craton Expansion of Late Ordovician Benthic Marine Invertebrates
Authors: Bretsky Peter W. , Klofak Susans M.
Published: October 2006

A biostratigraphic survey of 57 Late Ordovician marine shelly invertebrates from the
Climacograptus manitoulinensis
zone of eastern Canada supports suggestions that throughout the Early Phanerozoic benthic marine speciations occurred preferentially in marginal marine environments. The species subsequently spread onto the craton. There is no obvious positive correlation between the times of first appearance of new associations or novel communities along the continental margin and the first appearance on the craton of the species making up these communities. Taxonomic similarities between marine communities that occupied both marginal and cratonic regimes may reflect a more static local ecology than the evolutionary dynamics of a piecemeal species-by-species reassembly.
An Approach to Complexity: Numerical Computations
Authors: Smarr Larry L.
Published: October 2006

The use of supercomputers and modern color-imaging techniques for numerical computation is beginning to fulfill von Neumann's vision that digital computers would become the most appropriate tool for solving nonlinear partial differential equations. An example of this approach, a model for the gas flow in the vicinity of a black hole, is described. From such calculations comes a realization that the multidimensional, dynamic solutions of nonlinear partial differential equations can exhibit complex behavior compared to what one normally encounters in analytic solutions. This complexity includes small-scale chaotic structure and large-scale persistently ordered structure. Computational methodology and the aesthetics that derive from it are discussed.
Computers in Production Agriculture
Authors: Holt Donald A.
Published: October 2006

Modern production agriculture in the United States is becoming so complex and sophisticated that computers may soon be an essential tool of successful farm operation and management. Farmers are vigorously seeking information on relevant computer technology and using it as rapidly as economics and availability permit. Their demand for this technology is, however, price-sensitive under current economic conditions. The agricultural research and development system has a long way to go to provide the large integrated software and hardware packages—including simulators and expert systems interfaced with monitoring and control devices—needed to help American farmers retain their competitive edge.
Template-Directed Synthesis of Novel, Nucleic Acid-Like Structures
Authors: Schwartz Alan W. , Orgel Leslie E.
Published: October 2006

In studying the origins of life, it is important to examine reactions of substrate mixtures that could plausibly have accumulated on the primitive earth. Nucleoside diphosphates would probably have been synthesized along with the standard nucleotides under prebiotic conditions. For these reasons, the template-directed reactions of activated derivatives of these diphosphates, alone or mixed with activated nucleotides, were investigated. An activated derivative of deoxyguanosine 3′,5′-diphosphate condensed efficiently on a polycytidylate template to give oligonucleotide analogues in which each 3′,5′-phosphodiester bond was replaced by a pyrophosphate linkage. Oligomers were formed even in the absence of a template, but much more slowly. Template-directed condensation occurred also with an analogous deoxyadenosine derivative on polyuridylic acid and with an analogous acycloguanosine derivative on polycytidylic acid.
Competition for Phosphorus: Differential Uptake from Dual-Isotope—Labeled Soil Interspaces Between Shrub and Grass
Authors: Caldwell Martyn M. , Eissenstat David M. , Richards James H. , Allen Michael F.
Published: October 2006

Two species of
Agropyron
grass differed strikingly in their capacity to compete for phosphate in soil interspaces shared with a common competitor, the sagebrush
Artemisia tridentata
. Of the total phosphorus-32 and -33 absorbed by
Artemisia
, 86 percent was from the interspace shared with
Agropyron spicatum
and only 14 percent from that shared with
Agropyron desertorum
. Actively absorbing mycorrhizal roots of
Agropyron
and
Artemisia
were present in both interspaces, where competition for the labeled phosphate occurred. The results have important implications about the way in which plants compete for resources below ground in both natural plant communities and agricultural intercropping systems.
Mainbelt Asteroids: Dual-Polarization Radar Observations
Authors: Ostro Steven J. , Campbell Donald B. , Shapiro Irwin I.
Published: October 2006

Observations of 20 asteroids in the main belt between Mars and Jupiter provide information about the nature of these objects' surfaces at centimeter-to-kilometer scales. At least one asteroid (Pallas) is extremely smooth at centimeter-to-meter scales. Each asteroid appears much rougher than the Moon at some scale between several meters and many kilometers. The range of asteroid radar albedos is very broad and implies substantial variations in porosity or metal concentration (or both). The highest albedo estimate, for the asteroid Psyche, is consistent with a surface having porosities typical of lunar soil and a composition nearly entirely metallic.
Anthropoid Origins in Asia? New Discovery of
Amphipithecus
from the Eocene of Burma
Authors: Ciochon Russell L. , Savage Donald E. , Tint Thaw , Maw Ba
Published: October 2006

A new fossil of the primate
Amphipithecus mogaungensis
Colbert from the late Eocene of Burma shows that this species has a mandibular and molar morphology very similar to Oligocene and post-Oligocene higher primates. It has an exceptionally deep jaw. Its brachybunodont first and second molars have smooth enamel but lack hypoconulids. The shape of its second molar is nearly square—an advanced higher primate feature.
Amphipithecus mogaungensis
and related taxon
Pondaungia cotteri
Pilgrim are the earliest known higher primates. They suggest that Southeast Asia was an early theater of higher primate diversification.
Oroclinal Bending of the Southern Sierra Nevada Batholith
Authors: McWilliams Michael , Li Yianping
Published: October 2006

Structural, magmatic, and isotopic features of the southern Sierra Nevada batholith are deflected clockwise with respect to its central and northern parts. Directions of magnetization at three localities in the southern Sierra Nevada are progressively deflected; this is consistent with the hypothesis that the region was tectonically rotated in an orocline. No paleomagnetic deflection was observed northwest of the White Wolf-Kern Canyon fault system. Oroclinal bending of a block bounded by the San Andreas, Garlock, and White Wolf-Kern Canyon faults may have occurred before about 16 × 10
6
years ago. The deformation may have been a response to shear at the western boundary of the North American plate caused by oblique subduction.
Stone Age Prehistory of Northern Spain
Authors: Straus Lawrence Guy
Published: October 2006

The Vasco-Cantabrian region of Spain is one of the few areas of the world where a large sample of archeological sites has yielded a detailed record of the changes in the human condition in the period spanning Neanderthal times from about 125,000 years ago until the adoption of food production, less than 6000 years ago in this area. During this time, human adaptations underwent a series of crucial transformations involving profound changes in cultural systems and perhaps also in aspects of the biological basis for culture.
A 6-GeV Storage Ring: An Advanced Photon Research Facility
Authors: Eisenberger P.
Published: October 2006

The high brightness of synchrotron radiation produced by storage rings has enhanced research capability by factors of 10
6
to 10
8
, from the ultraviolet to the x-ray region. There has been a steady growth in synchrotron radiation research of interest in physics, chemistry, biology, geology, and the other physical sciences and their associated technologies. A large number of university, government, and industrial research organizations are utilizing this new capability at existing facilities. In the process, new partnerships have been created among these communities that have enabled each to contribute its expertise and to obtain its needed capability. A 6—gigaelectron volt storage ring, designed for use with periodic magnetic insertion devices called wigglers and undulators, has been proposed; such a facility could provide further enhancements of 10
4
to 10
6
in capability and could double the synchrotron radiation research capacity in the United States. This enhanced capability and capacity will provide new opportunities for a broad range of scientific and technological interests.
Infrared Astronomy After IRAS
Authors: Rieke G. H. , Werner M. W. , Thompson R. I. , Becklin E. E. , Hoffmann W. F. , Houck J. R. , Low F. J. , Stein W. A. , Witteborn F. C.
Published: October 2006

The 250,000 sources in the recently issued Infrared Astronomy Satellite (IRAS) all-sky infrared catalog are a challenge to astronomy. Many of these sources will be studied with existing and planned ground-based and airborne telescopes, but many others can no longer even be detected now that IRAS has ceased to operate. As anticipated by advisory panels of the National Academy of Sciences for a decade, study of the IRAS sources will require the Space Infrared Telescope Facility (SIRTF), a cooled, pointed telescope in space. This instrument may be the key to our understanding of cosmic birth—the formation of planets, stars, galaxies, active galactic nuclei, and quasars. Compared with IRAS and existing telescopes, SIRTF's power derives from a thousandfold gain in sensitivity over five octaves of the spectrum.
The Next Generation of Personal Computers
Authors: Crecine John D.
Published: October 2006

Surprisingly affordable workstations with powerful graphics and computational capabilities will be on the desks of students and professionals within the next 2 years. Leading computer manufacturers and universities are creating a UNIX-based systems software regime that allows for portable applications software that can run on a wide range of workstations and that exploits emerging technologies.
Structure of Ribosomal Subunits of
M. vannielii:
Ribosomal Morphology as a Phylogenetic Marker
Authors: Stöffler-Meilicke Marina , Böhme Claudia , Strobel Olaf , Böck August , Stöffler Georg
Published: October 2006

On the basis of ribosomal morphology, it has been proposed that the sulfur-metabolizing archaebacteria constitute a group (the eocytes) with a phylogenetic importance equal to that of the eubacteria, archaebacteria, and eukaryotes. It has been further proposed that eocytes should be given kingdom status. Ribosomal subunits from the methanogenic archaebacterium
Methanococcus vannielii
were examined by electron microscopy, and their structures were compared to those of other archaebacterial, eubacterial, and eukaryotic ribosomes. 30
S
subunits from
M. vannielii
showed the elongated contour and the one-third to two-thirds partition characteristic of such subunits. In addition, the angled asymmetric projections of those subunits showed a squarish base and a beak on the head. 50
S
subunits from
M. vannielii
were seen in both crown and kidney views. In crown views, the L1 protuberance was frequently pronounced and split; an incision below this protuberance and a protrusion at the base of the particle were also observed. Although previous studies suggested that certain of these structural features were found exclusively in ribosomes from sulfur-metabolizing archaebacteria, these new results indicate that such features also occur in ribosomes from a typical methanogenic archaebacterium and thus may not be reliable phylogenetic markers.
Living
Nautilus
Embryos: Preliminary Observations
Authors: Arnold John M. , Carlson Bruce A.
Published: October 2006

Nautilus
, long recognized as the most primitive living cephalopod, provides insight into molluscan evolution. Despite many attempts, embryos have not been observed until now. This report details the surface morphology and extraembryonic circulatory pattern. It was found that development, as in other extant cephalopods, is direct, without larval stages. There appears to be no embryonic protoconch associated with shell ontogeny.
Development of Visual Pattern Discrimination in the Fly Depends on Light Experience
Authors: Mimura K.
Published: October 2006

Pattern discrimination by dewinged walking flies (
Boettcherisca peregrina
) was tested in behavioral experiments. After emergence, the flies were deprived of light or visual patterns. Deprivation impaired the normal development of visual pattern discrimination without impairing phototaxis. Flies kept in a lighted, white, unpatterned environment could not discriminate visual patterns, nor could flies kept in continuous darkness. These results indicate that there is considerable plasticity in the structure of the visual system of these flies.
Photosynthesis-Associated Gene Families: Differences in Response to Tissue-Specific and Environmental Factors
Authors: Simpson June , Van Montagu Marc , Herrera-Estrella Luis
Published: October 2006

The endogenous small subunit of the ribulose-1,5-bisphosphate carboxylase gene
rbcS
and the light-harvesting chlorophyll a/b-binding protein gene (
LHCP
) of pea are expressed in a light-inducible manner and are active mainly in green chloroplast-containing tissue. Chimeric genes under control of the 5′-flanking sequences of the
rbcS
ss
3.6 or
LHCP
AB
80 genes from pea were used to study the factors relating to the tissue-specific and light-inducible expression of these nuclear-encoded genes in transgenic tobacco plants. The results show that plastid development plays a crucial role in the activation of expression of these chimeric genes. Particular members of each of the above gene families respond differently to tissue-specific and environmental factors. Furthermore, the light-inducible expression directed by the 5′-flanking sequence of
ss
3.6
rbcS
gene is not exclusively mediated by phytochrome, but probably is controlled in large part by another photoreceptor.
Japanese Competitiveness and Japanese Management
Authors: Minabe Shigeo
Published: October 2006

Japanese-style management and industrial policy are shown to serve as a source of industrial dynamism and are used as a way to illuminate what is wrong with the American system. Japanese labor practices—specifically extra hours of unpaid work—are seen as a form of insurance fee that the worker pays in exchange for job security.
Evolution of Meson Science in Japan
Authors: Yamazaki Toshimitsu
Published: October 2006

Forty years after Yukawa predicted the existence of mesons, experimental research activities with the use of mesons were started in Japan. Particles of the "second generation," which have nothing to do with the structure of ordinary materials, such as muons, K mesons, and other exotic particles have been exploited as unique probes to study new constituents of matter.
Arctic Research in the National Interest
Authors: Washburn A. L. , Weller Gunter
Published: October 2006

The Arctic Research and Policy Act of 1984 was designed to advance arctic research in the national interest. Some of the research fields that require attention are weather and climate; national defense; renewable and nonrenewable resources; transportation; communications and space-disturbance effects; environmental protection; health, culture, and socioeconomics; and international cooperation. A research framework recommended by the Arctic Research Commission includes, in order of priority, integrated investigations to understand: (i) the Arctic Ocean (including the marginal seas, sea ice, and seabed) and how the ocean and atmosphere operate as coupled components of the arctic system; (ii) the coupled atmosphere and land components and how their interaction governs the terrestrial environment; and (iii) the high-latitude upper atmosphere and its extension into the magnetosphere with emphasis on predicting and mitigating effects on communications and defense systems. A separate recommendation is for high priority research to resolve the major health, behavioral, and cultural problems related to the arctic environment. Recommendations are also made concerning support services and management.
Observations of Pentagonally Twinned Precipitate Needles of Germanium in Aluminum
Authors: Dahmen U. , Westmacott K. H.
Published: October 2006

Unusual pentagonally twinned precipitates were observed in a high-resolution transmission electron microscopy study of needle-shaped germanium particles in aluminum. Although commonly found in small particles formed on substrates, such twinning has not been seen in precipitates grown in the solid state. The morphologies and orientation relationships are consistent with symmetry principles.
Macroeconomics in an Open Economy
Authors: Cooper Richard N.
Published: October 2006

The customary treatment of national economies as closed and self-contained must be substantially modified to allow for those economies that typically trade goods, services, and securities with other countries in increasing volume. Open economy macroeconomics is essential to understanding the major events of the U.S. economy over the past half dozen years. Both the sharp rise in the dollar and the unprecedentedly large U.S. trade deficit are linked to the U.S. budget deficit, as is the drop in the rate of inflation.
Crustal Structure of Yunnan Province, People's Republic of China, from Seismic Refraction Profiles
Authors: Kan Rong-Ju , Hu Hong-Xiang , Zeng Rong-Sheng , Mooney Walter D. , McEvilly Thomas V.
Published: October 2006

Seismic refraction, profiles in Yunnan Province, southwestern China, define the crustal structure in an area of active tectonics on the southern end of the Himalaya-Burma arc. The crustal thickness ranges from 38 to 46 kilometers, and the relatively low mean crustal velocity indicates a crustal composition compatible with normal continental crust and consisting mainly of meta-sedimentary and silicic intrusive rocks, with little mafic or ultramafic component. This composition suggests a crustal evolution involving sedimentary processes on the flank of the Yangtze platform rather than the accretion of oceanic island arcs, as has been proposed. An anomalously low upper-mantle velocity observed on one profile but not on another at right-angles to it may indicate active tectonic processes in the mantle or seismic anisotropy.
Long-Term Downward Trend in Total Solar Irradiance
Authors: Willson R. C. , Hudson H. S. , Frohlich C. , Brusa R. W.
Published: October 2006

The first 5 years (from 1980 to 1985) of total solar irradiance observations by the first Active Cavity Radiometer Irradiance Monitor (ACRIM I) experiment on board the Solar Maximum Mission spacecraft show a clearly defined downward trend of -0.019% per year. The existence of this trend has been confirmed by the internal self-calibrations of ACRIM I, by independent measurements from sounding rockets and balloons, and by observations from the Nimbus-7 spacecraft. The trend appears to be due to unpredicted variations of solar luminosity on time scales of years, and it may be related to solar cycle magnetic activity.
Long-Term Brightness Variations of Neptune and the Solar Cycle Modulation of Its Albedo
Authors: Lockwood G. W. , Thompson D. T.
Published: October 2006

The visual brightness and albedo of Neptune vary periodically during the 11-year solar cycle with an amplitude of 4%, anticorrelated with the variation of solar ultraviolet output. A seasonal trend in color suggests that Neptune, like Uranus, may have a slightly reddened pole.
Wind Speed and Mortality Rate of a Marine Fish, the Northern Anchovy (
Engraulis mordax
)
Authors: Peterman Randall M. , Bradford Michael J.
Published: October 2006

Large variability in recruitment of marine fishes creates challenging management problems. In northern anchovy (
Engraulis mordax
), there is a significant linear relation between larval mortality rate and the frequency of calm, low wind speed periods during the spawning season, possibly because calm winds permit maintenance of concentrated patches of larval food. Neither cannibalism on larvae nor offshore transport contributed significantly to interannual variation in early larval mortality. These results are consistent with the hypothesis that wind-driven turbulent mixing affects variability in survival of young fish larvae. However, abundance of recruits does not necessarily reflect abundance of larvae surviving through this early stage.
Focal Points in Mass Spectrometry
Authors: Delgass W. N. , Cooks R. G.
Published: October 2006

Mass spectrometry has advanced with the renaissance of time-of-flight mass analysis, the use of ion traps as analyzers and reactors, the application of tandem mass spectrometers to problems in ionic reaction mechanisms and chemical analysis, and the development of new desorption ionization techniques. These developments have allowed determination of the molecular weight distributions for polymers through the 10,000-dalton range, as well as the molecular weight and partial sequence of biopolymers of similar size. Surfaces can be characterized by use of the mass, energy, and angle distributions of particles ejected by sputtering or by laser-induced desorption. Mass spectrometry has yielded new information on the kinetics of catalytic surface reactions and on the reactivity of metal clusters.
Phosphorus in Antique Iron Music Wire
Authors: Goodway Martha
Published: October 2006

Harpsichords and other wire-strung musical instruments were made with longer strings about the beginning of the 17th century. This change required stronger music wire. Although these changes coincided with the introduction of the first mass-produced steel (iron alloyed with carbon), carbon was not found in samples of antique iron harpsichord wire. The wire contained an amount of phosphorus sufficient to have impeded its conversion to steel, and may have been drawn from iron rejected for this purpose. The method used to select pig iron for wire drawing ensured the highest possible phosphorus content at a time when its presence in iron was unsuspected. Phosphorus as an alloying element has had the reputation for making steel brittle when worked cold. Nevertheless, in replicating the antique wire, it was found that low-carbon iron that contained 0.16 percent phosphorus was easily drawn to appropriate gauges and strengths for restringing antique harpsichords.
Geophysics Smorgasbord Was Spread in Baltimore
Authors: Kerr Richard A.
Published: October 2006

Geophysicists specializing in everything from atmospheric science to volcanology converged on Baltimore for the spring meeting of the American Geophysical Union held 18 to 21 May. The range of fare was huge, but here is a sampler: two high-energy phenomena—nuclear testing and the less frequent cratering by large impacts—and an imperceptibly slow process—the motion of the tectonic plates.
More Superconductivity Questions Than Answers
Authors: Robinson Arthur L.
Published: October 2006

Although making liquid nitrogen—temperature superconductors is easy enough that high school science projects already feature them, researchers still have little idea how the new ceramic oxides work and therefore little guidance for improving them. At the International Workshop on Novel Mechanisms of Superconductivity, held from 22 to 26 June in Berkeley, California, theorists reviewed a host of competing explanations of how these materials come by their remarkable properties, but they could not get far in sifting through the candidates for the best one.

One cause of the unsettled situation is that theorists have not yet pushed their models far enough to make many specific predictions about physical properties and therefore to provide a reason to choose one theory over another. But experimental data for comparison with theory are lacking, too. For example, experimentalists are just now succeeding in being able to grow single crystals and thin films of the ceramic oxide superconductors, whose properties were shown at the workshop to be highly anisotropic. Measurements already made on the polycrystalline sintered material available up to now are difficult to interpret and therefore need to be repeated on good-quality crystals and films, where the variation of properties with crystallographic orientation can be mapped out.

Given the high level of Japanese activity in the field, it was surprising that no researchers from industrial laboratories in Japan presented their findings at the workshop. In the light of a budding international competition in commercializing superconductors, some American scientists interpreted the absence as an attempt to protect proprietary advances. A more pleasant surprise was the attendance of a delegation of six Soviet scientists, although one of the fathers of superconductivity theory, Vitaly Ginzburg of the P.N. Lebedev Institute of Physics in Moscow, who was expected, did not come.
The 30-Kilodalton Gene Product of Tobacco Mosaic Virus Potentiates Virus Movement
Authors: Deom Carl M. , Oliver Melvin J. , Beachy Roger N.
Published: October 2006

The proposed role of the 30-kilodalton (kD) protein of tobacco mosaic virus is to facilitate cell-to-cell spread of the virus during infection. To directly define the function of the protein, a chimeric gene containing a cloned complementary DNA of the 30-kD protein gene was introduced into tobacco cells via a Ti plasmid-mediated transformation system of
Agrobacterium tumefaciens
. Transgenic plants regenerated from transformed tobacco cells expressed the 30-kD protein messenger RNA and accumulated 30-kD protein. Seedlings expressing the 30-kD protein gene complemented the Ls1 mutant of TMV, a mutant that is temperature-sensitive in cell-to-cell movement. In addition, enhanced movement of the Ls1 virus at the permissive temperature was detected in seedlings that express the 30-kD protein gene. These results conclusively demonstrate that the 30-kD protein of tobacco mosaic virus potentiates the movement of the virus from cell to cell.
Search for a New Exchange-Rate Regime
Authors: Williamson John
Published: October 2006

The regime of unmanaged floating exchange rates was implicitly judged a failure when, with the Plaza Agreement, attempts at cooperative exchange-rate management were reintroduced primarily because of concern at the size of misalignments. Any satisfactory successor regime will need to limit misalignments while retaining the genuine social benefits of exchange-rate flexibility. It is argued that a system of target zones for exchange rates, ideally embedded in a more comprehensive set of guidelines for international economic policy coordination, could best reconcile these needs.
High-Resolution Electron Microscopy and Scanning Tunneling Microscopy of Native Oxides on Silicon
Authors: Carim A. H. , Dovek M. M. , Quate C. F. , Sinclair R. , Vorst C.
Published: October 2006

High-resolution transmission electron microscopy and scanning tunneling microscopy have been combined to examine the structure of the thin "native" oxide that forms on silicon surfaces at room temperature. Differences in the cleaning procedures for silicon wafers may affect the morphology of this oxide and critically influence further processing on the silicon substrates. An etch that ended with a dip in hydrofluoric acid provided a thinner oxide and a lower interface step density than did a sulfuric peroxide treatment. The availability of complementary information from high-resolution transmission electron microscopy and scanning tunneling microscopy is discussed.
IRAS Serendipitous Survey Observations of Pluto and Charon
Authors: Sykes Mark V. , Cutri Roc M. , Lebofsky Larry A. , Binzel Richard P.
Published: October 2006

On 16 August 1983 the Infrared Astronomical Satellite made two separate pointed observations of Pluto and its moon Charon. Because of the small angular displacement of the system between the times of measurement, the Pluto-Charon system was identified as a source in the Serendipitous Survey (SSC 14029+0518). Detections were made at 60 and 100 micrometers with color-corrected flux densities of 581 ± 58 and 721 ± 123 millijanskys, respectively. Pluto is best described as having a dark equatorial band, and brighter polar caps of methane ice extending to ±45° latitude, at most. An upper limit of approximately 9 meter-amagats is placed on the column abundance of a methane atmosphere on Pluto, which is comparable to recent upper limits based on independent ground-based spectroscopy.
Eclipse Measurements of Io's Sodium Atmosphere
Authors: Schneider Nicholas M. , Donald Donald M. , Wells William K. , Trafton Laurence M.
Published: October 2006

The satellites of Jupiter eclipsed each other in 1985, and these events allowed an unusual measurement of the sodium in Io's extended atmosphere. Europa was used as a mirror to look back through the Io atmosphere at the sun. The measured column abundances suggest that the atmosphere is collisionally thin above 700 kilometers and may be collisionally thin to the surface. The sodium radial profile above 700 kilometers resembles a 1500 kelvin exosphere with a surface density near 2 × 10
4
sodium atoms per cubic centimeter, but a complete explanation of the dynamics requires a more complex nonthermal model: the calculated loss rates suggest that the atmosphere is being replaced on a time scale of hours.