bluuebunny/crossref_metadata_2025 huggingface dataset:
The Double Quasar 0957+561: Examination of the Gravitational Lens Hypothesis Using the Very Large Array
Authors: Greenfield P. E. , Roberts D. H. , Burke B. F.
Published: October 2006

A full 12-hour synthesis at 6-centimeter wavelength with the Very Large Array confirms the major features previously reported for the double quasar 0957+561. In addition, the existence of radio jets apparently associated with both quasars is demonstrated. Gravitational lens models are now favored on the basis of recent optical observations, and the radio jets place severe constraints on such models. Further radio observations of the double quasar are needed to establish the expected relative time delay in variations between the images.
Simulated Wind Pollination and Airflow Around Ovules of Some Early Seed Plants
Authors: Niklas Karl J.
Published: October 2006

Scale models of various early seed plant ovules and cupules were analyzed both for their characteristic air disturbance patterns and for the frequency of impact with airborne models of pollen (pseudopollen). The fossils on which the models were based had been arranged in an evolutionary sequence purporting to show the origin of the integument by the acropetal fusion and reduction in length of a subtending truss of lobes. Wind tunnel analyses of scale models showing the various stages in the consolidation of these preintegumentary lobes indicated that turbulent flow increases and becomes localized around the nucellar apex (salpinx) with the syngenesis and length reduction of those lobes. Similarly, the frequency of windborne pseudopollen impact increased. Thus, the transition from the megasporangium to the fully integumented ovule appears to favor increased wind-mediated pollination.
Encystment Discovered in a Marine Copepod
Authors: Coull Bruce C. , Grant Jonathan
Published: October 2006

It has been believed that marine crustacea do not encyst as adults. The benthic copepod
Heteropsyllus nunni
has been found to encyst in intertidal sands in the summer; free-living forms are abundant in the winter. A unique platelike structure on the cephalothorax is thought to be the site of cyst formation.
Mate Selection and Behavioral Thermoregulation in Fowler's Toads
Authors: Fairchild Lincoln
Published: October 2006

Male Fowler's toads produce mating calls that are affected by the body size and temperature of the caller. Females are able to discriminate between variations in these calls and select the largest available males. By thermoregulation, males are able to alter their calls to make them more attractive to females.
Solar Flare Acceleration of Solar Wind: Influence of Active Region Magnetic Field
Authors: Lundstedt H. , Wilcox J. M. , Scherrer P. H.
Published: October 2006

The direction of the photospheric magnetic field at the site of a solar flare is a good predictor of whether the flare will accelerate solar wind plasma. If the field has a southward component, high-speed solar wind plasma is usually observed near the earth about 4 days later. If the field has a northward component, such high-speed solar wind is almost never observed. Southward-field flares may then be expected to have much larger terrestrial effects than northward flares.
Application of Space Technology to Geodynamics
Authors: Flinn Edward A.
Published: October 2006

Measurements of the movement and deformation of tectonic plates are needed for many research areas in geodynamics, but observations with adequate accuracy and frequency of measurement are not feasible if classical geodetic methods are used. Long-baseline microwave interferometry and laser ranging to Earth satellites are among the new techniques that have been developed within the past decade to make the required measurements. Fixed and mobile stations using both these methods have been constructed in several countries and are now being used in an internationally coordinated research program. Baseline length accuracy better than 2 to 3 centimeters (1 standard deviation) is expected within the next 5 years.
Vibration Signal Transmission in Spider Orb Webs
Authors: Masters W. Mitchell , Markl Hubert
Published: October 2006

Vibration transmission from the prey-catching region to the hub of the unloaded orb web of
Nuctenea sclopetaria
was measured by laser vibrometry. Compared to transverse or lateral vibrations, longitudinal vibration shows less attenuation and contains more directional information. It is transmitted well throughout the entire frequency range measured (1 to 10,000 hertz).
Superheavy Elements: An Early Solar System Upper Limit for Elements 107 to 110
Authors: Nozette S. , Boynton W. V.
Published: October 2006

The abundance of samarium-152 in the Santa Clara iron meteorite is found to be 108 × 10
7
atoms per gram. This quantity, if attributed to fission of a superheavy element with atomic number 107 to 109, limits the amount of superheavy elements in the early solar system to 1.7 × 10
–5
times the abundance of uranium-238. For element 110, the limit is 3.4 × 10
–5
Models of the Earth's Core
Authors: Stevenson D. J.
Published: October 2006

Combined inferences from seismology, high-pressure experiment and theory, geomagnetism, fluid dynamics, and current views of terrestrial planetary evolution lead to models of the earth's core with the following properties. Core formation was contemporaneous with earth accretion; the core is not in chemical equilibrium with the mantle; the outer core is a fluid iron alloy containing significant quantities of lighter elements and is probably almost adiabatic and compositionally uniform; the more iron-rich inner solid core is a consequence of partial freezing of the outer core, and the energy release from this process sustains the earth's magnetic field; and the thermodynamic properties of the core are well constrained by the application of liquid-state theory to seismic and laboratory data.
Competition Between Ant Species: Outcome Controlled by Parasitic Flies
Authors: Feener Donald H.
Published: October 2006

Experimental evidence demonstrates that the parasitic phorid fly
Apocephalus
shifts the competitive balance between the ant species
Pheidole dentata
and
Solenopsis texana
by interfering with the defensive behavior of
Pheidole dentata
major workers (soldiers). This represents one of the first examples of a parasite affecting competitive interactions among terrestrial animals in natural communities. Similar complex interactions are probably common in many ant communities.
The Ice Lover: Biology of the Harp Seal (
Phoca groenlandica
)
Authors: Ronald K. , Dougan J. L.
Published: October 2006

The number of harp seals,
Phoca groenlandica
(Erxleben 1777) may now range from 2.25 million to 3 million. The total population is divided among three separate breeding stocks in the White Sea, the Greenland Sea, and the Northwest Atlantic. The continued exploitation of the Northwest Atlantic stock has caused controversy, primarily because of public concern for the fate of the newborn "whitecoat." The harp seal's life-cycle is marked by a progression from on-ice birth to in-water mating and subsequent on-ice molt. An extensive migration follows, taking these animals northward to high Arctic summering grounds and southward in an autumnal return migration to the breeding grounds. Harp seals are efficient divers and possess well-developed microsensory perceptions associated with anatomical adaptation to their environment. The relation between our understanding of the basic biology of the species and the confrontation that occurs between these mammals and man is considered with respect to our technological invasion of the North, the regulated commercial kill, and the slow movement toward multispecies management. Sound decisions regarding the exploitation of this species can only be made with a knowledge of its biology.
Technology, Enterprise, and American Economic Growth
Authors: Lewis Jordan D.
Published: October 2006

The weakening of technology-based economic growth in the United States may be due to inflation and to fundamental characteristics of American society and not, as is often suggested, to low expenditures on research and development, too much regulation, or risk-averse corporate management. Accordingly, renewed economic growth will require constraining inflation, as well as private initiatives and public policies that reflect the nature of technological progress and of the American people.
Anesthesia Cutoff Phenomenon: Interfacial Hydrogen Bonding
Authors: Chiou Jang-Shing , Ma Shao-Mu , Kamaya Hiroshi , Ueda Issaku
Published: October 2006

Anesthesia "cutoff" refers to the phenomenon of loss of anesthetic potency in a homologous series of alkanes and their derivatives when their sizes become too large. In this study, hydrogen bonding of 1-alkanol series (ethanol to eicosanol) to dipalmitoyl-L-α-phosphatidylcholine (DPPC) was studied by Fourier transform infrared spectroscopy (FTIR) in DPPC-D
2
O-in- CCl
4
reversed micelles. The alkanols formed hydrogen bonds with the phosphate moiety of DPPC and released the DPPC-bound deuterated water, evidenced by increases in the bound O-H stretching signal of the alkanol-DPPC complex and also in the free O-D stretching band of unbound D
2
O. These effects increased according to the elongation of the carbon chain of 1-alkanols from ethanol (C
2
) to 1-decanol (C
10
), but suddenly almost disappeared at 1-tetradecanol (C
14
). Anesthetic potencies of these alkanols, estimated by the activity of brine shrimps, were linearly related to hydrogen bond-breaking activities below C
10
and agreed with the FTIR data in the cutoff at C
10
.
Galactic Evolution: A Survey of Recent Progress
Authors: Strom K. M. , Strom S. E.
Published: October 2006

Current observational knowledge bearing on the evolution of elliptical and disk galaxies is reviewed. Particular emphasis is placed on identifying the factors that appear common to all galaxies of a particular type as opposed to those that seem to depend on environmental conditions. The success of various classes of galactic formation and evolution models used to confront these data is evaluated.
Suppression of Reflex Postural Tonus: A Role of Peripheral Inhibition in Insects
Authors: Zill Sasha N. , Moran David T.
Published: October 2006

Postural reflexes act through a single excitatory motoneuron of the several that innervate a flexor muscle of the cockroach leg. A peripheral inhibitory neuron whose axon accompanies this excitatory motoneuron is able to suppress muscle tensions developed from postural reflexes without affecting centrally generated muscle tensions. The inhibitory neuron could thus serve to rapidly suppress postural tensions at the initiation of escape.
Fine Particles in the Soufriere Eruption Plume
Authors: Woods David C. , Chuan Raymond L.
Published: October 2006

The size distributions of fine particles measured at tropospheric altitudes in the periphery of the eruption plume formed during the 17 April 1979 eruption of Soufriere Volcano and in the low-level effluents on 15 May 1979 were found to be bimodal, having peak concentrations at geometric mean diameters of 1.1 and 0.23 micrometers. Scanning electron microscopy and energy-dispersive x-ray analysis of the samples revealed an abundance of aluminum and silicon and traces of sodium, magnesium, chlorine, potassium, calcium, and iron in the large-particle mode. The submicrometer-sized particles were covered with liquid containing sulfur, assumed to be in the form of liquid sulfuric acid.
Aerosols from the Soufriere Eruption Plume of 17 April 1979
Authors: Sedlacek William A. , Heiken Grant , Zoller William H. , Germani Mark S.
Published: October 2006

Aerosol samples collected from the 17 April 1979 eruption plume of Soufriere, St. Vincent, at altitudes between 1.8 and 5.5 kilometers were physically and chemically very similar to the ash that fell on the island. Higher altitude samples (7.3 and 9.5 kilometers) had a much lower ash content but comparable concentrations of sulfate, which were above the background concentration found at these altitudes.
Restoration of the Plasticity of Binocular Maps by NMDA After the Critical Period in
Xenopus
Authors: Udin Susan B. , Scherer Warren J.
Published: October 2006

Visual input during a critical period of development plays a major role in the establishment of orderly connections in the developing visual system. In
Xenopus laevis
, the matching of visual maps from the two eyes to the optic tectum depends on binocular visual input during the critical period, which extends from late tadpole to early juvenile stages. Alterations in eye position, which produce a mismatch of the tectal maps, normally evoke a compensatory adjustment in the map of the ipsilateral eye only during the critical period. However, continuous application of the glutamate receptor agonist
N
-methyl-D-aspartate (NMDA) after the normal end of the critical period restores this ability to realign the visual map.
Inhibition of Steroid Glycoalkaloid Accumulation by Arachidonic and Eicosapentaenoic Acids in Potato
Authors: Tjamos Eleftherios C. , Kuć Joseph A.
Published: October 2006

Eicosapentaenoic and arachidonic acids extracted from the fungus
Phytophthora infestans
elicit the accumulation of fungitoxic sesquiterpenoid stress metabolites and inhibit the accumulation of steroid glycoalkaloids in potato tubers. This dual activity, which did not occur with other saturated and unsaturated fatty acids tested, corresponds to the activity of incompatible races of
Phytophthora infestans
and crude elicitor preparations from
Phytophthora infestans
that contain bound forms eicosapentaenoic and arachidonic acids. Arachidonic acid applied to potato slices, which had been aged for various time intervals, elicited the accumulation of sesquiterpenoid stress metabolites and concomitantly inhibited the accumulation of steroid glycoalkaloids.
Tissue, Developmental, and Tumor-Specific Expression of Divergent Transcripts in Wilms Tumor
Authors: Huang Annie , Campbell Christine E. , Bonetta Laura , McAndrews-Hill Monica S. , Chilton-MacNeill Susan , Coppes Max J. , Law David J. , Feinberg Andrew P. , Yeger Herman , Williams Bryan R. G.
Published: October 2006

The Wilms tumor locus on chromosome 11p13 has been mapped to a region defined by overlapping, tumor-specific deletions. Complementary DNA clones representing transcripts of 2.5 (WIT-1) and 3.5 kb (WIT-2) mapping to this region were isolated from a kidney complementary DNA library. Expression of WIT-1 and WIT-2 was restricted to kidney and spleen. RNase protection revealed divergent transcription of WIT-1 and WIT-2, originating from a DNA region of <600 bp. Both transcripts were present at high concentrations in fetal kidney and at much reduced amounts in 5-year-old and adult kidneys. Eleven of 12 Wilms tumors classified as histopathologically heterogeneous exhibited absent or reduced expression of WIT-2, whereas only 4 of 14 histopathologically homogeneous tumors showed reduced expression. These data demonstrate a molecular basis for the pathogenetic heterogeneity in Wilms tumorigenesis.
Differences and Similarities in DNA-Binding Preferences of MyoD and E2A Protein Complexes Revealed by Binding Site Selection
Authors: Blackwell T. Keith , Weintraub Harold
Published: October 2006

A technique was developed for studying protein-DNA recognition that can be applied to any purified protein, partially purified protein, or cloned gene. From oligonucleotides in which particular positions are of random sequence, that subset to which a given protein binds is amplified by the polymerase chain reaction and sequenced as a pool. These selected and amplified binding site (SAAB) "imprints" provide a characteristic set of preferred sequences for protein binding. With this technique, it was shown that homo- and heterooligomers of the helix-loop-helix proteins MyoD and E2A recognize a common consensus sequence, CA--TG, but otherwise bind to flanking and internal positions with different sequence preferences that suggest half-site recognition. These findings suggest that different combinations of dimeric proteins can have different binding sequence preferences.
Male Lek Formation and Female Calling in a Population of the Arctiid Moth
Estigmene acrea
Authors: Willis Mark A. , Birch Martin C.
Published: October 2006

Abdominal coremata in male
Estigmene acrea
(Lepidoptera: Arctiidae) are inflated and displayed in aggregations to which females and males are attracted and where mating occurs (leks). Female
E. acrea
also release a sex pheromone which attracts males. These two mating behaviors occur in the same populations at different peak times on the same nights. Thus male lek formation and female calling occur in the same species, and the male coremata, or related structures, appear to be integrally associated with lek behavior.
A New Role for Temperature in Insect Dormancy: Cold Maintains Diapause in Temperate Zone Diptera
Authors: Tauber Maurice J. , Tauber Catherine A. , Nechols James R. , Helgesen Robert G.
Published: October 2006

In early autumn, high temperatures terminate diapause in the alfalfa blotch leafminer
Agromyza frontella
; low temperatures maintain diapause. These responses subserve a thermally malleable dormancy and allow flexibility in the annual number of generations. The view that favorable conditions cannot reverse the course of diapause are contradicted by the data on
A. frontella
. A better understanding of the diverse seasonal adaptations that insects have evolved may add precision to life history studies and phenological models in insect pest management.
Advances in Picosecond Spectroscopy
Authors: Rentzepis P. M.
Published: October 2006

Progress in the technology of picosecond spectroscopy in the past few years has made possible the generation of well-characterized pulses emitted by synchronously pumped tunable dye lasers. In addition, the development of sensitive emission and absorption detection methods and the advent of picosecond Raman and coherent anti-Stokes Raman spectroscopy make possible the direct observation of picosecond transient spectra and lifetimes. The information obtained allows the complete determination of mechanisms through the identification of transient states, radicals, and ions that evolve during the course of a chemical or biological reaction.
Japanese Industrial Development and Policies for Science and Technology
Authors: Shishido Toshio
Published: October 2006

Two important factors that contributed to Japan's economic success were government investment in industrial development and the early recognition that a good educational system is a prerequisite to technological progress. Government policies promoted the importation of technologies from Europe and North America and encouraged the education of students abroad. This facilitated the rapid development of Japanese industry and the adaptation of foreign technologies to local conditions. Many of the methods used to develop industry in Japan could be used to advantage in developing countries today.
An Unusual Lepidopteran Sex Pheromone System in the Bagworm Moth
Authors: Leonhardt B. A. , Neal J. W. , Klun J. A. , Schwarz M. , Plimmer J. R.
Published: October 2006

The female sex pheromone of the bagworm moth is (
R
)-1-methylbutyl decanoate. The antipode is biologically inactive and it neither enhances nor detracts from the potency of the
R
enantiomer. Unlike other moths for which female pheromones have been identified, the female secretes the pheromone from glands on her thorax and it is disseminated from hair that is shed from her body.
The Economics of Small Farms
Authors: Tweeten Luther
Published: October 2006

The role of the small farm in American agriculture has been the focus of much public discussion since Secretary of Agriculture Bob Bergland elevated farm structure to the national political agenda during the Carter Administration. Eight hypotheses based on common assertions concerning the alleged advantages of the small farm were tested in the light of available empirical evidence. No basis was found to accept any of the eight hypotheses. There may be reasons to preserve and even encourage small farms but they are not the reasons commonly given for political initiatives and public policies favoring small farms. Although it is questionable whether any size of farm can be viewed as optimal, the strongest case is for the typical moderate-size family farm of today rather than for small farms or large industrial-type farms.
Strontium Isotope Fractionation in the Kiglapait Intrusion
Authors: Morse S. A.
Published: October 2006

The initial ratio of strontium-87 to strontium-86 rises systematically from 0.70395 to 0.70662 over the upper 10 percent of the Kiglapait layered intrusion. This ratio is strongly correlated with potassium and rubidium. Contamination, exchange, and magma mixing fail to account for the increase, which is ascribed to the imperfect retention of radiogenic strontium-87 in feldspar-like structural units of the melt inherited from the magma source. These accidents in chemical discrimination persist most readily in anhydrous melts.
An Ictidosaur Fossil from North America
Authors: Chatterjee Sankar
Published: October 2006

Teeth of a North American ictidosaur,
Pachygenelus milleri
, n. sp., found in the Upper Triassic Dockum Group of Texas, indicate that it is very similar to
Pachygenelus monus
of South Africa and
Chaliminia musteloides
of South America. The presence of a Gondwana element in the Northern Hemisphere attests to the ease of dispersal of the Late Triassic vertebrates through Pangea. Ictidosaurs are small, highly advanced, carnivorous cynodonts that display a mosaic of reptilian and mammalian features in the masticatory apparatus. They were contemporaneous with early mammals and probably closely related to them.
The New Milky Way
Authors: Blitz Leo , Fich Michel , Kulkarni Shrinivas
Published: October 2006

Our understanding of the large-scale structure of the Milky Way has undergone considerable revision during the past few years. The Galaxy is larger and much more massive than was previously supposed; the newly discovered mass consists of nonluminous matter which is likely to be the dominant form of matter in the universe. New analyses of the atomic hydrogen gas show that the disk of the Galaxy is about twice as extended as was previously thought. Beyond the sun, the gas is concentrated in large-scale, coherent spiral arms indicative of a regular four-armed spiral pattern. The outer edge of the disk has a remarkable scalloping.
Eruption-Triggered Avalanche, Flood, and Lahar at Mount St. Helens—Effects of Winter Snowpack
Authors: Waitt R. B. , Pierson T. C. , MacLeod N. S. , Janda R. J. , Voight Barry , Holcomb R. T.
Published: October 2006

An explosive eruption of Mount St. Helens on 19 March 1982 had substantial impact beyond the vent because hot eruption products interacted with a thick snowpack. A blast of hot pumice, dome rocks, and gas dislodged crater-wall snow that avalanched through the crater and down the north flank. Snow in the crater swiftly melted to form a transient lake, from which a destructive flood and lahar swept down the north flank and the North Fork Toutle River.
Tetraplex Formation of a Guanine-Containing Nonameric DNA Fragment
Authors: Jin Renzhe , Breslauer Kenneth J. , Jones Roger A. , Gaffney Barbara L.
Published: October 2006

A combination of spectroscopic and calorimetric techniques has been used to characterize the structures formed by a family of short, guanine-containing DNA single strands of the form d[GGTTXTTGG], X = A, C, G, T. In 1 molar NaCl at low temperatures, these molecules do not behave like single strands, but rather exhibit properties consistent with tetraplex formation. The standard state enthalpies, entropies, and free energies for formation of each tetraplex have been measured, as have preliminary nuclear magnetic resonance (NMR) spectra. In 1 molar KCl, the melting behavior of the structure or structures is more complex than in 1 molar NaCl. This observation may be related to the recently proposed "sodium-potassium switch."
The Formation of Stellar Systems from Interstellar Molecular Clouds
Authors: Gehrz Robert D. , Black David C. , Solomon Philip M.
Published: October 2006

Star formation, a crucial link in the chain of events that led from the early expansion of the universe to the formation of the solar system, continues to play a major role in the evolution of many galaxies. Observational and theoretical studies of regions of ongoing star formation provide insight into the physical conditions and events that must have attended the formation of the solar system. Such investigations also elucidate the role played by star formation in the evolutionary cycle which appears to dominate the chemical processing of interstellar material by successive generations of stars in spiral galaxies like our own. New astronomical facilities planned for development during the 1980's could lead to significant advances in our understanding of the star formation process. Efforts to identify and examine both the elusive protostellar collapse phase of star formation and planetary systems around nearby stars will be especially significant.
Mapping from Space: The Metric Camera Experiment
Authors: Konecny G. , Reynolds M. , Schroeder M.
Published: October 2006

The Spacelab metric camera experiment acquired stereoscopic high-resolution black-and-white and color infrared photographs of various regions of the world. In total, an area of about 11 million square kilometers was covered. Because of the delay in launching the shuttle until 28 November, illumination conditions were frequently poor over many candidate targets. However, unique high-quality images with a ground resolution of about 20 meters were obtained by increasing camera exposure time. Initial image analysis has shown that these images may be used for earth mapping at the scale 1:100,000.
Electron Flux Intensity Distributions Observed in Response to Particle Beam Emissions
Authors: Wilhelm Klaus , Stüdemann Wolfgang , Riedler Willibald
Published: October 2006

Modifications of the suprathermal electron population were observed by an electron spectrometer on Spacelab 1 during electron beam injections. The instrument covered its energy range (100 to 12,500 electron volts) and field of view (≈2π) with high energy, angle, and time resolution. The measurements demonstrate the presence of strong beam-plasma interactions during high-current modes of accelerator operations. Spacecraft charging could be studied as well as processes that accelerated electrons to more than four times the injection energy.
Resonant Nuclear Fusion Processes and the Gamma Rays of SS 433
Authors: Boyd R. N. , Newsom G. H. , Collins G. W. , Wiescher M.
Published: October 2006

Gamma-ray spectral lines have recently been reported coming from the celestial object SS 433, which is known to emit high-speed jets in opposite directions. The proposed identification of the lines as coming from fusion reactions on nitrogen nuclei as part of the carbon-nitrogen-oxygen cycle operating in the jets has now received observational support. Predictions of strengths and widths of additional lines which, if seen, would provide valuable new information about conditions giving rise to the jets are presented.
A Mutant of
Arabidopsis
Lacking a Chloroplast-Specific Lipid
Authors: Browse J. , McCourt P. , Somerville C. R.
Published: October 2006

In order to investigate the functional significance of membrane lipid unsaturation, we have isolated a series of mutants of
Arabidopsis thaliana
which are deficient in particular membrane fatty acids. The first of these mutants completely lacks Δ3-
trans
-hexadecenoate, an acyl group that until now has been thought to play an important role in the structure or function of thylakoid membranes in photosynthetic eukaryotes. The apparent absence of any marked physiological effect of the mutation illustrates the potential of this approach to the analysis of membrane structure and function.
A Sign Inversion Mechanism for Enzymatic Supercoiling of DNA
Authors: Brown Patrick O. , Cozzarelli Nicholas R.
Published: October 2006

Both the introduction and the removal of supertwists by DNA gyrase change the linking number of DNA in steps of two. This surprising finding provides strong evidence that gyrase acts by a mechanism, called sign inversion, whereby a positive supercoil is directly inverted into a negative one via a transient double-strand break.
Durability of the Accretion Disk of Millisecond Pulsars
Authors: Michel F. Curtis , Dessler A. J.
Published: October 2006

Pulsars with pulsation periods in the millisecond range are thought to be neutron stars that have acquired an extraordinarily short spin period through the accretion of stellar material spiraling down onto the neutron star from a nearby companion. Nearly all the angular momentum and most of the mass of the companion star is transferred to the neutron star. During this process, wherein the neutron star consumes its companion, it is required that a disk of stellar material be formed around the neutron star. In conventional models it is supposed that the disk is somehow lost when the accretion phase is finished, so that only the rapidly spinning neutron star remains. However, it is possible that, after the accretion phase, a residual disk remains in stable orbit around the neutron star. The end result of such an accretion process is an object that looks much like a miniature (about 100 kilometers), heavy version of Saturn: a central object (the neutron star) surrounded by a durable disk.
High-Speed Lightwave Transmission in Optical Fibers
Authors: Kogelnik Herwig
Published: October 2006

There has been considerable progress in the telecommunications technology based on the transmission of lightwaves through optical fibers. Systems experiments in the 1.55-micrometer band have now demonstrated the capability of transmitting at rates as high as 2 gigabits per second over fiber lengths exceeding 100 kilometers, without the use of repeaters to boost the signal. Elements of this progress are advances in the fabrication of low-loss single-mode fibers, in the spectral control of semiconductor junction lasers assuring single-frequency operation, and in high-speed detectors and receivers.
Native Iron in the Continental Lower Crust: Petrological and Geophysical Implications
Authors: Haggerty Stephen E. , Toft Paul B.
Published: October 2006

Lower crustal granulite xenoliths recovered from a kimberlite pipe in western Africa contain native iron (Fe
0
) as a decomposition product of garnet and ilmenite. Magnetic measurements show that less than 0.1 percent (by volume) of iron metal is present. Data from geothermometry and oxygen geobarometry indicate that the oxide and metal phases equilibrated between iron-wüstite and magnetite-wüstite buffers, which may represent the oxidation state of the continental lower crust, and the depleted lithospheric upper mantle. Ferromagnetic native iron could be stable to a depth of ≃ 95 kilometers and should be considered in the interpretation of long-wavelength static magnetic anomalies.
Origins
Authors: Weinberg Steven
Published: October 2006

The farthest of the galaxies that can be seen through the large ground-based telescopes of modern astronomy, such as those on La Palma in the Canary Islands, are so far away that they appear as they did close to the time of the origin of the universe, perhaps some 10 billion years ago. Much has been learned, and much has still to be learned, about the young universe from optical and radio telescopes, but these instruments cannot be used to look directly at the universe in its first few hundred thousand years. Instead, they are used to search the relatively recent past for relics of much earlier times. Together with experiments planned for the next generation of elementary particle accelerators, astronomical observations should continue to extend what is known about the universe backward in time to the Big Bang and may eventually help to reveal the origins of the physical laws that govern the universe.
The Meteorological Satellite: Overview of 25 Years of Operation
Authors: Smith W. L. , Bishop W. P. , Dvorak V. F. , Hayden C. M. , McElroy J. H. , Mosher F. R. , Oliver V. J. , Purdom J. F. , Wark D. Q.
Published: October 2006

The first weather satellite was launched on 1 April 1960. In the 25 years since, weather satellites have contributed to improved weather analyses and forecasts worldwide. As a maturing component of a global observing system, the meteorological satellite promises even greater financial benefits and a higher quality of life to mankind.
De Gustibus Non Est Disputandem
: A Spiral Center for Taste in the Brain of the Teleost Fish,
Heterotis niloticus
Authors: Braford Mark R.
Published: October 2006

The teleost fish,
Heterotis niloticus
, has elaborate paired, spiraled pharyngeal structures that aid in concentrating and swallowing food. These epibranchial organs are lined by an epithelium rich in taste buds. Both the taste buds and the muscles of the epibranchial organs are innervated by components of the vagal nerve. Horseradish peroxidase neuronal tracing experiments show that these nerve fibers are connected centrally to an enormous epibranchial portion of the vagal lobes—a special visceral sensory and motor region of the medulla. The epibranchial portion of the vagal lobe is among the most remarkable structures found in the brains of vertebrates, for it is itself a spiral.
Plasma Observations Near Uranus: Initial Results from Voyager 2
Authors: Bridge H. S. , Belcher J. W. , Coppi B. , Lazarus A. J. , McNutt R. L. , Olbert S. , Richardson J. D. , Sands M. R. , Selesnick R. S. , Sullivan J. D. , Hartle R. E. , Ogilvie K. W. , Sittler E. C. , Bagenal F. , Wolff R. S. , Vasyliunas V. M. , Siscoe G. L. , Goertz C. K. , Eviatar A.
Published: October 2006

Extensive measurements of low-energy positive ions and electrons in the vicinity of Uranus have revealed a fully developed magnetosphere. The magnetospheric plasma has a warm component with a temperature of 4 to 50 electron volts and a peak density of roughly 2 protons per cubic centimeter, and a hot component, with a temperature of a few kiloelectron volts and a peak density of roughly 0.1 proton per cubic centimeter. The warm component is observed both inside and outside of
L
= 5, whereas the hot component is excluded from the region inside of that
L
shell. Possible sources of the plasma in the magnetosphere are the extended hydrogen corona, the solar wind, and the ionosphere. The Uranian moons do not appear to be a significant plasma source. The boundary of the hot plasma component at
L
= 5 may be associated either with Miranda or with the inner limit of a deeply penetrating, solar wind-driven magnetospheric convection system. The Voyager 2 spacecraft repeatedly encountered the plasma sheet in the magnetotail at locations that are consistent with a geometric model for the plasma sheet similar to that at Earth.
Bacterivory: A Novel Feeding Mode for Asteroid Larvae
Authors: Rivkin Richard B. , Bosch Isidro , Pearse John S. , Lessard Evelyn J.
Published: October 2006

Planktotrophic larvae that occur beneath the annual sea ice in the Antarctic assimilate organic solutes and preferentially ingest bacteria, whereas they actively exclude phytoplankton. In regions where phytoplankton biomass is temporally limited by light or nutrient concentrations, the growth and development of planktotrophic larvae may not be directly coupled to phytoplankton production.
Antarctica: Measuring Glacier Velocity from Satellite Images
Authors: Lucchitta B. K. , Ferguson H. M.
Published: October 2006

Many Landsat images of Antarctica show distinctive flow and crevasse features in the floating part of ice streams and outlet glaciers immediately below their grounding zones. Some of the features, which move with the glacier or ice stream, remain visible over many years and thus allow time-lapse measurements of ice velocities. Measurements taken from Landsat images of features on Byrd Glacier agree well with detailed ground and aerial observations. The satellite-image technique thus offers a rapid and cost-effective method of obtaining average velocities, to a first order of accuracy, of many ice streams and outlet glaciers near their termini.
Solar Neutrinos: Experimental Approaches
Authors: Friedlander Gerhart , Weneser Joseph
Published: October 2006

This article discusses the new experiments, under way or proposed, that will measure the flux of solar neutrinos and so probe the "solar neutrino puzzle." Both radiochemical and electronic detector experiments are analyzed in terms of possible findings relevant to astrophysics and neutrino properties. Important elements are sensitivity to the principal components of the solar neutrino spectrum, directionality of the detector response, and an energy-measuring capability that might provide a unique identifying signal. Experiments beyond those currently under way will probably be needed, and development of real-time detectors is particularly important.
Supernova 1987A: Notes from All Over
Authors: Waldrop M. Mitchell
Published: October 2006

As Supernova 1987A in the Large Magellanic Cloud continues on its inexorable course—it has currently reached magnitude 3.3, with perhaps another magnitude of brightening to go in the next few months before it begins its long, slow fade into oblivion—astronomers are following its every step with avid interest. Some recent developments:
Changes in Stratospheric Ozone
Authors: Cicerone Ralph J.
Published: October 2006

The ozone layer in the upper atmosphere is a natural feature of the earth's environment. It performs several important functions, including shielding the earth from damaging solar ultraviolet radiation. Far from being static, ozone concentrations rise and fall under the forces of photochemical production, catalytic chemical destruction, and fluid dynamical transport. Human activities are projected to deplete substantially stratospheric ozone through anthropogenic increases in the global concentrations of key atmospheric chemicals. Human-induced perturbations may be occurring already.
Short Interval Time Measurement by a Parasitoid Wasp
Authors: Schmidt J. M. , Smith J. J. B.
Published: October 2006

The number of eggs laid by the parasitoid wasp
Trichogramma
varies with host volume. The duration of the wasp's initial transit across the host surface during host examination is used to determine the number of eggs laid. A 2.5-second reduction in initial transit resulted in a 30% reduction in eggs oviposited, demonstrating that these wasps measure short time intervals. This measure is used for progeny allocation independent of host body size.
Ultraviolet Observations of Solar Fine Structure
Authors: Dere Kenneth P. , Bartoe John-David F. , Brueckner Guenter E. , Cook John W. , Socker Dennis G.
Published: October 2006

The High Resolution Telescope and Spectrograph was flown on the Spacelab-2 shuttle mission to perform extended observations of the solar chromosphere and transition zone at high spatial and temporal resolution. Ultraviolet spectroheliograms show the temporal development of macrospicules at the solar limb. The C IV transition zone emission is produced in discrete emission elements that must be composed of exceedingly fine (less than 70 kilometers) subresolution structures.
Tetrahedral Intermediate in a Specific α-Chymotrypsin Inhibitor Complex Detected by Laser Raman Spectroscopy
Authors: Hess George P. , Seybert David , Lewis Aaron , Spoonhower John , Cookingham Robert
Published: October 2006

Laser Raman spectroscopy indicates that inhibition of α-chymotrypsin by 2-phenylethaneboronic acid occurs in two steps: (i) the formation of a loosely bound complex, in which the boron remains in a trigonal configuration; and (ii) reaction of the boron with a functional group in the catalytic site of the enzyme, resulting in a reversible, stable tetrahedral adduct.
Geophysics: Ancient Air, Ozone, and Faults
Authors: Kerr Richard A.
Published: October 2006

Researchers who gathered in San Francisco in December at the annual fall meeting of the American Geophysical Union heard the usual variety of talks treating everything from Earth's core to the tenuous wisps of solar particles far beyond Pluto. Earthquakes, the local California variety in particular, figured prominently, as did the currently popular subjects of ancient air trapped in amber and the deepening Antarctic ozone hole.
Advances in Measurement Science
Authors: Pool Robert
Published: October 2006

Year after year, physicists measure various quantities with increasing accuracy and see various objects in increasing detail. These advances are vital, because science's understanding of the physical world is necessarily limited by the accuracy with which science can measure that world. The Instrument and Measurement Science Topical Group of the American Physical Society sponsored several symposia at the recent APS March meeting in New Orleans that discussed recent advances in measurement and observation.
A Model of Solar Luminosity Modulation by Magnetic Activity Between 1954 and 1984
Authors: Lean J. , Foukal P.
Published: October 2006

A simple model based on the changes in excess radiation from bright magnetic faculae and on changes in reduced radiation from dark spots is remarkably successful in matching the slow variations of total solar irradiance measured simultaneously by the ERB and ACRIM satellite radiometers between 1981 and 1984. This model was extended back to 1954 to reconstruct the modulation of irradiance by magnetic activity during the past three 11-year solar cycles. The model predicts that the sun is consistently brighter at activity maximum than at minimum. The 0.07 percent brightening at the peak of the last cycle in 1980 was more pronounced than the brightenings found for either of the two previous cycles, even though cycle 19, which peaked around 1957, had the largest sunspot number amplitude in the history of reliable sunspot records.
Cell-Autonomous Recognition of the Rust Pathogen Determines
Rp1
-Specified Resistance in Maize
Authors: Bennetzen Jeffrey L. , Blevins William E. , Ellingboe Albert H.
Published: October 2006

The
Rp1
gene of maize determines resistance to the leaf rust pathogen
Puccinia sorghi.
X-ray treatment of heterozygous (
Rp1 Oy/rp1 oy
) maize embryos generated seedlings with yellow sectors lacking
Rp1
. Yellow sectored seedlings inoculated with rust spores gave rust pustule formation in yellow (
Rp1
-lacking) sectors and hypersensitive resistance in green tissues, thereby demonstrating that the
Rp1
gene product is cellautonomous in its action. In cases where the hypersensitive reaction was initiated in green (
Rp1
) tissue next to a yellow sector, the hypersensitive response appeared to be propagated poorly, if at all, through
Rp1
-lacking cells.
Thermodynamic Efficiency of Brittle Frictional Mountain Building
Authors: Barr Terence D. , Dahlen F. A.
Published: October 2006

An active fold-and-thrust belt in unchanging tectonic and climatic conditions attains a dynamic steady-state in which the influx of accreted material at the toe is balanced by the erosive efflux off the top. The overall balance of energy in such a steady-state fold-and-thrust belt is described by the equation
Ė
=
Ẇ
G
+
Q
, where
Ė
is the rate at which both mechanical and heat energy are added from external sources,
Ẇ
G
is the rate of work performed against gravitational body forces, and
Q
is the rate at which waste heat flows out of the upper and lower boundaries. The total amount of power being supplied to the active Taiwan fold-and-thrust belt by the subducting Eurasian plate and in situ radioactivity is 4.2 gigawatts. Because only 0.5 gigawatts are expended in doing useful work against gravity and the remaining 3.7 gigawatts are ejected as heat, the efficiency of brittle frictional mountain building in Taiwan is 11 percent.
Effect of the Orbital Debris Environment on the High-Energy Van Allen Proton Belt
Authors: Konradi Andrei
Published: October 2006

Orbital debris in the near-Earth environment has reached a number density sufficient for a significant collisional interaction with some of the long-lived high-energy protons in the radiation belt. As a result of a continuing buildup of a shell of man-made debris, the lifetimes of high-energy protons whose trajectories remain below 1500 kilometers will decrease to the point where in the next decades we can expect a noticeable reduction in their fluxes.
Submicrometer Superconducting YBa
2
Cu
3
O
6+x
Particles Made by a Low-Temperature Synthetic Route
Authors: Horowitz H. S. , McLain S. J. , Sleight A. W. , Druliner J. D. , Gai P. L. , VanKavelaar M. J. , Wagner J. L. , Biggs B. D. , Poon S. J.
Published: October 2006

Evidence suggests that superconducting, orthorhombic YBa
2
Cu
3
O

6+
x

(
x
≳ 0.5) is always produced by oxidation of the oxygen-deficient, tetragonal form (
x
≲ 0.5) of this phase (commonly referred to as 123). A synthetic route whereby solution-derived, carbon-free precursors are decomposed at 650° to 700°C in inert atmosphere to yield tetragonal 123 is now available. Appropriate precursors include hydrated oxides derived from the hydrolysis of organometallic solutions and aqueous solution-derived hyponitrites. Subsequent oxidation of the tetragonal phase at 400°C results in submicrometer particles of orthorhombic 123. Superconductivity (
T
c
onset ≈ 87 K) has been confirmed in these materials by both Meissner effect and specific-heat measurements.
Hydrogen Sulfide on IO: Evidence from Telescopic and Laboratory Infrared Spectra
Authors: Nash Douglas B. , Howell Robert R.
Published: October 2006

Evidence is reported for hydrogen sulfide (H
2
S) on Io's surface. An infrared band at 3.915 (± 0.015) micrometers in several ground-based spectra of Io can be accounted for by reflectance from H
2
S frost deposited on or cocondensed with sulfur dioxide (SO
2
) frost. Temporal variation in the occurrence and intensity of the band suggests that condensed H
2
S on Io's surface is transient, implying a similar variation of H
2
S abundance in Io's atmosphere. The band was observed in full-disk measurements of Io at several orbital longitudes, including once at 24° (∼ 0.5 hour after Io's reappearance after an eclipse)—but not after another reappearance at 22°—and once at 95°(on Io's leading hemisphere). These results suggest that condensed H
2
S is sparse and variable but can be widespread on Io's surface. When present, it would not only produce the infrared band but would brighten Io's typical surface at ultraviolet and visible wavelengths.
Cone Cell-Specific Genes Expressed in Retinoblastoma
Authors: Bogenmann E. , Lochrie M. A. , Simon M. I.
Published: October 2006

Retinoblastoma, an intraocular tumor that occurs in children, has long been regarded, on the basis of morphological criteria, as a malignancy of the photoreceptor cell lineage. Here it is shown that when this tumor is grown in vitro, the cells express highly specialized photoreceptor cell genes. Transcripts for the transducin alpha subunit, T
Cα
, which is specific to the cone cell, as well as transcripts for the red or green cone cell photopigment, were found in seven out of seven low-passage retinoblastoma cell lines. No marker genes specific to rod cells were expressed, suggesting that retinoblastoma has a cone cell lineage.
A Point Mutation in the c-
myc
Locus of a Burkitt Lymphoma Abolishes Binding of a Nuclear Protein
Authors: Zajac-Kaye Maria , Gelmann Edward P. , Levens David
Published: October 2006

A 20-base pair region in the first intron of the human c-
myc
gene was identified as the binding site of a nuclear protein. This binding site is mutated in five out of seven Burkitt lymphomas sequenced to date. To investigate the protein-recognition region in greater detail, the abnormal c-
myc
allele from a Burkitt lymphoma line (PA682) that carries a t(8;22) chromosomal translocation was used. A point mutation in the binding region of the PA682 c-
myc
DNA abolished binding of this nuclear protein. This protein may be an important factor for control of c-
myc
expression, and mutations in its recognition sequence may be associated with c-
myc
activation in many cases of Burkitt lymphoma.