bluuebunny/crossref_metadata_2025 huggingface dataset:
The Cyril Burt Question: New Findings
Authors: Dorfman D. D.
Published: October 2006

Cyril Burt presented data in his classic paper "Intelligence and social mobility" that were in perfect agreement with a genetic theory of IQ and social class. A detailed analysis of these data reveals, beyond reasonable doubt, that they were fabricated from a theoretical normal curve, from a genetic regression equation, and from figures published more than 30 years before Burt completed his surveys.
Future Sources of Organic Raw Materials
Authors: Shapiro Irving S.
Published: October 2006

Industrial organizations, academic institutions, and national governments should agree on the cooperative roles each will play in planning the decades-ahead raw materials needs of the chemical industry, which is vital to a modern, international economic system. The raw material future of the industry depends as much on political and social concerns as it does on technical and economic considerations. The generation in charge now cannot in good conscience go on consuming the world's supply of hydrocarbons and not acknowledge a duty to generations that will follow.
Mediterranean Action Plan: An Interim Evaluation
Authors: Boxer Baruch
Published: October 2006

The Mediterranean Action Plan is an extensive program of regional environmental cooperation on technical and institutional approaches to pollution monitoring, environmental assessment, and policy-making. The simultaneous development of a regional monitoring network and legal instruments to protect the Mediterranean from pollution is an important achievement, which provides a firm basis for continuing cooperative efforts.
Strain in Southern California: Measured Uniaxial North-South Regional Contraction
Authors: Savage J. C. , Prescott W. H. , Lisowski M. , King N.
Published: October 2006

The plate tectonics model of the Pacific moving northwest relative to North America implies that the regional strain in California should be simple shear across a vertical plane striking N45°W or equivalently equal parts of north-south contraction and east-west extension. Measurements of the strain accumulation at seven separate sites in southern California in the interval 1972 through 1978 indicate a remarkably consistent uniaxial north-south contraction of about 0.3 part per million per year; the expected east-west extension is absent. It is not clear whether the period from 1972 through 1978 is anomalous or whether the secular strain in southern California is indeed a uniaxial north-south contraction.
Neutron Scattering: Progress and Prospects
Authors: Axe J. D.
Published: October 2006

Over the last decade the unique properties of neutrons have proven useful in a growing number of scientific disciplines. Neutron scattering, traditionally the probe of choice for many magnetic and spectroscopic studies, is now firmly established as an invaluable complement to x-ray scattering for structural and dynamic studies within many other areas of the material sciences, chemistry, and biology. In recent years the instruments and techniques have matured to the point where they are of increasing relevance to the understanding and design of improved practical, everyday materials.
Irradiance Modulation Used to Examine Sound-Radiating Cuticular Motion in Insects
Authors: Masters W. Mitchell
Published: October 2006

A new, noncontact, optical technique for measurement of movements smaller than a few micrometers has been used to record cuticular motion of insects as they produce sound. The instrument described is highly sensitive to surface movement and offers good spatial resolution, broad dynamic range, tolerance of substantial background motion of the target surface, portability, and simplicity, and as such appears to hold promise for measuring other biologically interesting motions that have proved difficult to measure by other available techniques.
Ionosphere of Venus: First Observations of the Dayside Ion Composition Near Dawn and Dusk
Authors: Taylor Harry A. , Brinton Henry C. , Bauer Siegfried J. , Hartle Richard E. , Donahue Thomas M. , Cloutier Paul A. , Michel F. Curtis , Daniell Robert E. , Blackwell Bruce H.
Published: October 2006

The first in situ measurements of the composition of the ionosphere of Venus are provided by independent Bennett radio-frequency ion mass spectrometers on the Pioneer Venus bus and orbiter spacecraft, exploring the dawn and duskside regions, respectively. An extensive composition of ion species, rich in oxygen, nitrogen, and carbon chemistry is identified. The dominant topside ion is O
+
, with C
+
, N
+
, H
+
, and He
+
as prominent secondary ions. In the lower ionosphere, the ionization peak or F
1
layer near 150 kilometers reaches a concentration of about 5 × 10
3
ions per cubic centimeter, and is composed of the dominant molecular ion, O
2
+
, with NO
+
, CO
+
, and CO
2
+
, constituting less than 10 percent of the total. Below the O
+
peak near 200 kilometers, the ions exhibit scale heights consistent with a neutral gas temperature of about 180 K near the terminator. In the upper ionosphere, scale heights of all species reflect the effects of plasma transport, which lifts the composition upward to the often abrupt ionopause, or thermal ion boundary, which is observed to vary in height between 250 to 1800 kilometers, in response to solar wind dynamics.
Venus Upper Atmosphere Neutral Composition: Preliminary Results from the Pioneer Venus Orbiter
Authors: Niemann H. B. , Hartle R. E. , Kasprzak W. T. , Spencer N. W. , Hunten D. M. , Carignan G. R.
Published: October 2006

Measurements in situ of the neutral composition and temperature of the thermosphere of Venus are being made with a quadrupole mass spectrometer on the Pioneer Venus orbiter. The presence of many gases, including the major constituents CO
2
, CO, N
2
, O, and He has been confirmed. Carbon dioxide is the most abundant constituent at altitudes below about 155 kilometers in the terminator region. Above this altitude atomic oxygen is the major constituent, with O/CO
2
ratios in the upper atmosphere being greater than was commonly expected. Isotope ratios of O and C are close to terrestrial values. The temperature inferred from scale heights above 180 kilometers is about 400 K on the dayside near the evening terminator at a solar zenith angle of about 69°. It decreases to about 230 K when the solar zenith angle is about 90°.
Infrared Remote Sounding of the Middle Atmosphere of Venus from the Pioneer Orbiter
Authors: Taylor F. W. , Diner D. J. , Elson L. S. , Hanner M. S. , McCleese D. J. , Martonchik J. V. , Reichley P. E. , Houghton J. T. , Delderfield J. , Schofield J. T. , Bradley S. E. , Ingersoll A. P.
Published: October 2006

Orbiter infrared measurements of the Venus atmosphere in the 60- to 140-kilometer region show very small diurnal temperature differences near the cloud tops, increasing somewhat at higher levels. The seasonal (that is, equator to pole) contrasts are an order of magnitude larger, and the temperatures unexpectedly increase with increasing latitude below 80 kilometers. An isothermal layer at least two scale heights in vertical extent is found near the 100-kilometer altitude, where the temperature is about 175 K. Structure is present in the cloud temperature maps on a range of spatial scales. The most striking is at high latitude, where contrasts of nearly 50 K are observed between a cold circumpolar band and the region near the pole itself.
Melting of Io by Tidal Dissipation
Authors: Peale S. J. , Cassen P. , Reynolds R. T.
Published: October 2006

The dissipation of tidal energy in Jupiter's satellite Io is likely to have melted a major fraction of the mass. Consequences of a largely molten interior may be evident in pictures of Io's surface returned by Voyager I.
Atmospheric Halocarbons, Hydrocarbons, and Sulfur Hexafluoride: Global Distributions, Sources, and Sinks
Authors: Singh H. B. , Salas L. J. , Shigeishi H. , Scribner E.
Published: October 2006

The global distribution of fluorocarbon-12 and fluorocarbon-11 is used to establish a relatively fast interhemispheric exchange rate of 1 to 1.2 years. Atmospheric residence times of 65 to 70 years for fluorocarbon-12 and 40 to 45 years for fluorocarbon-11 best fit the observational data. These residence times rule out the possibility of any significant missing sinks that may prevent these fluorocarbons from entering the stratosphere. Atmospheric measurements of methyl chloroform support an 8- to 10-year residence time and suggest global average hydroxyl radical (HO) concentrations of 3 × 10
5
to 4 × 10
5
molecules per cubic centimeter. These are a factor of 5 lower than predicted by models. Additionally, methyl chloroform global distribution supports Southern Hemispheric HO levels that are a factor of 1.5 or more larger than the Northern Hemispheric values. The long residence time and the rapid growth of methyl chloroform cause it to be a potentially significant depleter of stratospheric ozone. The oceanic sink for atmospheric carbon tetrachloride is about half as important as the stratospheric sink. A major source of methyl chloride (3 × 10
12
grams per year), sufficient to account for nearly all the atmospheric methyl chloride, has been identified in the ocean.
Feathers of
Archaeopteryx
: Asymmetric Vanes Indicate Aerodynamic Function
Authors: Feduccia Alan , Tordoff Harrison B.
Published: October 2006

Vanes in the primary flight feathers of
Archaeopteryx
conform to the asymmetric pattern in modern flying birds. The asymmetry has aerodynamic functions and can be assumed to have evolved in the selective context of flight.
Cryptic Bioluminescence in a Midwater Shrimp
Authors: Warner Jon A. , Latz Michael I. , Case James F.
Published: October 2006

The mesopelagic shrimp
Sergestes similis
emits ventrally directed bioluminescence that closely matches the intensity of downward-directed illumination and is able to rapidly modify its light output to match changes in background intensity. Masking experiments show that the photoreceptors involved are the compound eyes or adjacent tissues. Light emission originates from modified portions of the hepatopancreas and is similar to oceanic light in angular distribution and spectral characteristics. Normally oriented animals respond minimally to upward-directed light.
Fluidization: Hydrodynamic Stabilization with a Magnetic Field
Authors: Rosensweig Ronald E.
Published: October 2006

Fluidization of magnetizable particles by a gas stream in the presence of a uniform applied magnetic field oriented parallel to the flow prevents the hydrodynamic instability that otherwise leads to bubbles and turbulent motion within the medium. The fluidized emulsion expands uniformly in response to gas flow speeds in excess of that at the incipient fluidization point, with transition from the quiescent stable state to bubbling occurring suddenly at a characteristic increased rate of flow. Experimental data demonstrate the dependence of this transition velocity on the intensity of the applied magnetic field, length of the bed, and type of magnetic solids. Data illustrate the pressure distribution through the bed medium, the bed flow characteristics, and other phenomena.
A Two-Fluid Approach to Town Traffic
Authors: Herman Robert , Prigogine Ilya
Published: October 2006

A two-fluid model of town traffic has been developed by extending ideas formulated in an earlier kinetic theory of multilane traffic. The-two fluids are taken to consist of moving cars and cars stopped as a result of traffic conditions. The average speed of the moving vehicles is assumed to be proportional to the fraction of the vehicles that are moving raised to a power that reflects the "goodness" of the traffic. It is then found that the trip time per unit distance is essentially linearly related to the stop time per unit distance, in general accord with data obtained in many cities. Relations are developed on this basis for flow, among other variables, versus average speed. These relations contain a new parameter that is identified with the quality of the traffic network system.
Nicotiana
Chromosome Coding for a Specific Polypeptide of the Small Subunit of Fraction 1 Protein
Authors: Chen Kevin , Sand Seaward A.
Published: October 2006

Fraction 1 protein has been isolated from leaves of a male sterile
Nicotiana tabacum
plant containing an extra
N. debneyi
chromosome. The extra chromosome induces appearance of a third polypeptide composing the small subunit of fraction 1 protein, which otherwise contains two polypeptides as is shown by analysis of numerous different cultivars of
N. tabacum
.
Calcium and Potassium in the Motor Organ of the Sensitive Plant: Localization by Ion Microscopy
Authors: Campbell Neil A. , Stika Katherine M. , Morrison George H.
Published: October 2006

The ion microscope was used to study potassium and calcium distributions in the main motor organ of
Mimosa pudica
L. The cortex of the motor organ has two cell types differing in location, structure, and ion distribution. Histochemical features portrayed in ion micrographs were plainly correlated with structures seen in the light and electron microscopes.
Gulf Stream: Velocity Fluctuations During the Late Cenozoic
Authors: Kaneps Ansis G.
Published: October 2006

Biostratigraphic analysis of seven piston cores from the southeastern Blake Plateau suggests that the upper Miocene to Recent sedimentary section at this location represents a history of deposition of calcareous ooze alternating with current-induced nondeposition or erosion. This record is primarily a result of long-term fluctuations in the velocity of the western boundary current or Gulf Stream, which sweeps the plateau. High-velocity phases of this current system, as signaled by hiatuses in the section, lie within the time limits 4.8 to 6.1, 3.9 to 4.4, 2.3 to 2.9, and 0 to 1.5 million years before present (B.P.). These time intervals are coeval with dated episodes of climatic decline and glaciation. The most intense acceleration of the Gulf Stream, as indicated by deep erosion of the Blake Plateau, occurred in the latest Miocene to earliest Pliocene (4.8 to 6.1 million years B.P.) in conjunction with a major expansion of the Antarctic ice cap. Subsequent accelerations of the Gulf Stream coincide with early Pliocene cooling in the Southern Hemisphere, worldwide expansion of high-altitude-high-latitude glaciers in the late Pliocene, and the classical glaciations of the Pleistocene. An additional, protracted increase in the average velocity of the Gulf Stream, which began in the late Miocene and culminated in the mid-Pliocene (about 3.8 million years B.P.), can be attributed to the gradual emergence of the Central American isthmus.
Lichen Growth Responses to Stress Induced by Automobile Exhaust Pollution
Authors: Lawrey James D. , Hale Mason E.
Published: October 2006

Growth rates were significantly suppressed in juvenile thalli (less than 0.1 square millimeter in initial size) of the saxicolous lichen
Pseudoparmelia baltimorensis
from a Potomac River island with high atmospheric lead burden as compared to the case for a similar island with a lower lead burden. However, larger thalli showed no significant changes in growth response as a result of atmospheric pollution stress. Disruptions in lichen growth thus appear to affect life stages when growth is most rapid and food reserves are low. Once a minimum thallus size is attained, the stress tolerance of the lichen increases.
Direct Marine-Continental Correlation: 150,000-Year Oxygen Isotope—Pollen Record from the North Pacific
Authors: Heusser Linda E. , Shackleton Nicholas J.
Published: October 2006

Core Y72 11 1 (43°15′N, 126°22′W) contains sediment of oxygen isotope stages 1 through 6 (substages 5a through 5e are well developed) and abundant pollen from the nearby continent, enabling us for the first time to obtain a direct marine-continental correlation of events in the last interglacial sensu lato. From stage 6 to substage 5e the vegetational record resembles that during the waning of the last glacial. During substage 5e, after a rapid increase of alder, western hemlock was abundant and significant amounts of redwood, oak, and Douglas fir appeared. These results suggest that vegetation on the adjacent continent during substage 5e was similar to that of the temperate conifer forests which developed in the Pacific Northwest during the Holocene. The vegetation record since that brief episode (which like the Eemian in northwest Europe lasted only a few thousand years) has been complex.
"Transfer Connections": Specialized Pathways for Nutrient Translocation in a Red Alga?
Authors: Wetherbee Richard
Published: October 2006

"Transfer connections" are morphologically and developmentally distinct pit connections in
Polysiphonia
(Ceramiales). They are intracellular rather than extracellular and have been observed between all cells of the diploid carposporophyte plus those specialized cells of the gametophyte suspected of providing nutritive materials to it.
Jupiter Plasma Wave Observations: An Initial Voyager 1 Overview
Authors: Scarf Frederick L. , Gurnett Donald A. , Kurth William S.
Published: October 2006

The Voyager 1 plasma wave instrument detected low-frequency radio emissions, ion acoustic waves, and electron plasma oscillations for a period of months before encountering Jupiter's bow shock. In the outer magnetosphere, measurements of trapped radio waves were used to derive an electron density profile. Near and within the Io plasma torus the instrument detected high-frequency electrostatic waves, strong whistler mode turbulence, and discrete whistlers, apparently associated with lightning. Some strong emissions in the tail region and some impulsive signals have not yet been positively identified.
Nautilus
Movement and Distribution in Palau, Western Caroline Islands
Authors: Saunders W. Bruce , Spinosa Claude
Published: October 2006

Long-term movement of up to 150 kilometers in 332 days by tagged, living
Nautilus
, and postmortem shell drift of 1000 kilometers in 138 days, corroborate and explain the cosmopolitan distribution of many fossil shelled cephalopods.
Mexico's Program for Science and Technology, 1978 to 1982
Authors: Flores Edmundo
Published: October 2006

In response to a request by President José López Portillo, the National Council of Science and Technology (CONACYT) worked out a program of scientific research and development in Mexico in keeping with the economic and social priorities of his administration—food production, energy, public health, and employment. Representatives from public, private, and academic sectors participated in preparing an inventory of needs for the development of human, economic, and physical resources. The program includes 2,489 projects in basic and applied sciences at a cost of $260 million to 1982 and 17,000 scholarships at a cost of $130 million.
Seasat Visible and Infrared Radiometer
Authors: McClain E. Paul , Marks Richard A.
Published: October 2006

Visual and infrared images produced by the Seasat visible and infrared radiometer (VIRR) are adequate for the identification of cloud, land, and water features. A statistical comparison of VIRR-derived sea-surface temperatures in a cloud-free region with a National Oceanic and Atmospheric Administration analysis based on various surface measurements taken in the same region showed agreement to ± 1.7°K root-mean-square.
Class II Aminoacyl Transfer Rna Synthetases: Crystal Structure of Yeast Aspartyl-trna Synthetase Complexed with tRNA
Asp
Authors: Ruff M. , Krishnaswamy S. , Boeglin M. , Poterszman A. , Mitschler A. , Podjarny A. , Rees B. , Thierry J. C. , Moras D.
Published: October 2006

The crystal structure of the binary complex tRNA
Asp
-aspartyl tRNA synthetase from yeast was solved with the use of multiple isomorphous replacement to 3 angstrom resolution. The dimeric synthetase, a member of class II aminoacyl tRNA synthetases (aaRS's) exhibits the characteristic signature motifs conserved in eight aaRS's. These three sequence motifs are contained in the catalytic site domain, built around an antiparallel β sheet, and flanked by three α helices that form the pocket in which adenosine triphosphate (ATP) and the CCA end of tRNA bind. The tRNA
Asp
molecule approaches the synthetase from the variable loop side. The two major contact areas are with the acceptor end and the anticodon stem and loop. In both sites the protein interacts with the tRNA from the major groove side. The correlation between aaRS class II and the initial site of aminoacylation at 3′-OH can be explained by the structure. The molecular association leads to the following features: (i) the backbone of the GCCA single-stranded portion of the acceptor end exhibits a regular helical conformation; (ii) the loop between residues 320 and 342 in motif 2 interacts with the acceptor stem in the major groove and is in contact with the discriminator base G and the first base pair UA; and (iii) the anticodon loop undergoes a large conformational change in order to bind the protein. The conformation of the tRNA molecule in the complex is dictated more by the interaction with the protein than by its own sequence.
Implications of the Gas Compositional Measurements of Pioneer Venus for the Origin of Planetary Atmospheres
Authors: Pollack James B. , Black David C.
Published: October 2006

Comparisons are made between the volatile inventories of the terrestrial planets, including Pioneer Venus data, and the predictions of three classes of theories for the origin of planetary atmospheres. Serious difficulties arise for the primary atmosphere and external source hypotheses. The grain accretion hypothesis can account for the trends in the volatile inventory from Venus to Earth to Mars, if volatiles were incorporated into planet-forming grains at nearly the same temperature for all of these planets, but at systematically lower pressures in the regions of planet formation farther from the center of the solar nebula.
Short-Term Cyclic Variations and Diurnal Variations of the Venus Upper Atmosphere
Authors: Keating G. M. , Taylor F. W. , Nicholson J. Y. , Hinson E. W.
Published: October 2006

Measurements of satellite drag obtained from the orbital decay of the Pioneer Venus orbiter on the nightside of Venus indicate an atomic oxygen atmosphere near 155 kilometers (an order of magnitude less dense than expected) with nighttime inferred exospheric temperatures averaging as low as 110 K. Densities at these altitudes decrease sharply from day to night, contrary to the predicted nighttime oxygen bulge. This decrease may be indicative of an unexpectedly weak transport across the evening terminator or a very strong heat sink at night that is possibly related to vertical eddy heat transport. Large periodic oscillations in density and inferred exospheric temperature are detected with a period of 5 to 6 days. We have subsequently discovered temperature variations of the same period in the stratosphere, which are tentatively interpreted as planetary-scale waves that may propagate upward producing the periodic variations in the thermosphere and exosphere. The peak-to-peak amplitude of the temperature oscillations associated with these waves apparently increases with altitude approximately as follows: 1 K (70 kilometers), 3 K (90 kilometers), 40 K (155 kilometers). Inferred nighttime exospheric temperatures are found to be asymmetric relative to midnight, minimizing on the morning side. The possibility of superrotation of the thermosphere, and exosphere is discussed.
Preliminary Results of the Pioneer Venus Small Probe Net Flux Radiometer Experiment
Authors: Suomi V. E. , Sromovsky L. A. , Revercomb H. E.
Published: October 2006

Net radiation measurements in the atmosphere of Venus indicate that the bulk of the atmosphere is radiatively cooling at high latitudes and heating at low latitudes. Similarity of features observed by all three probes indicate planetwide stratification. Flux variations within the clouds provide evidence of significant differences in cloud structure. A feature of unusually large opacity found near 60 kilometers at the north probe site is probably related to the unique circulation regime revealed by ultraviolet and infrared imagery. A stable layer between the cloud bottoms and about 35 kilometers contains several features in the flux profiles probably resulting from large-scale compositional stratifications rather than clouds. In the layer below 35 kilometers unexpectedly large fluxes were observed.
Atmospheric Refraction and Lake Monsters
Authors: Lehn W. H.
Published: October 2006

A survey of reported sightings of lake monster phenomena suggests that many of them may be attributable to atmospheric image distortion. The existence of the necessary conditions (surface temperature inversion and hence strong atmospheric refraction) can be inferred from most of the reports. Under such conditions familiar objects can easily take on unrecognizable form. Two photographs demonstrate the extent of the distortion that can occur.
Superconducting Properties of Protactinium
Authors: Smith J. L. , Spirlet J. C. , Müller W.
Published: October 2006

The superconducting transition temperature and upper critical magnetic field of protactinium were measured by alternating-current susceptibility techniques. Since the superconducting behavior of protactinium is affected by its 5
f
electron character, it is clear now that protactinium is a true actinide element.
Magnetospheres of the Galilean Satellites
Authors: Kivelson Margaret G. , Slavin James A. , Southwood David J.
Published: October 2006

The plasma and field perturbations of magnetospheres that would surround magnetized galilean satellites embedded in the corotating jovian plasma differ from those produced by interaction with an unmagnetized conductor. If the intrinsic satellite dipole is antiparallel to that of Jupiter, the magnetosphere will be open. It is predicted that Io has an internal magnetic field with a dipole moment of 6.5 × 10
22
gauss-cubic centimeters antiparallel to Jupiter's, and Io's special properties can be interpreted on the basis of a reconnecting magnetosphere.
The Colorado Plateaus: Cultural Dynamics and Paleoenvironment
Authors: Euler Robert C. , Gumerman George J. , Karlstrom Thor N. V. , Dean Jeffrey S. , Hevly Richard H.
Published: October 2006

Convergent archeological, geological, palynological, dendrochronological, and radiometric data provide a paleoenvironmental record for the American Southwest at a level of detail and time resolution not previously achieved. Many prehistoric cultural and demographic changes on the Colorado Plateaus coincided with environmental fluctuations defined by precisely dated geoclimatic and bioclimatic indicators. These coincidences support the interpretation that socioeconomic changes and population displacements were commonly triggered by environmental stress.
Changes in Carbon Fixation, Tuberization, and Growth Induced by CO
2
Applications to the Root Zone of Potato Plants
Authors: Arteca R. N. , Poovaiah B. W. , Smith O. E.
Published: October 2006

The root systems of potato plants (
Solanum tuberosum
L. var. Russet Burbank) treated with CO
2
for 12 hours showed an increase in dry matter as early as 2 days after the treatment. When treated plants were allowed to grow for 3 to 6 weeks there was a substantial increase in tuberization. In addition, there was an increase in stolon length, number of tubers per stolon, and overall dry weight after the enrichment of the root zone with CO
2
. Plants treated with CO
2
showed higher concentrations of malic and citric acids and of the cations Mg
2+
and Ca
2+
. The effect of CO
2
was more dramatic when CO
2
was applied to the root zone than when it was applied to the shoots.
Phycomyces
: Interference Between the Light Growth Response and the Avoidance Response
Authors: Harris Sally S. , Dennison David S.
Published: October 2006

Phycomyces
sporangiophores show a growth response to a light stimulus and an avoidance bending response to a physical barrier. A blue-light stimulus administered in conjunction with a barrier interferes with the avoidance bending response. This interference begins after a latency of about 3 minutes and continues for a period of 4 to 5 minutes.
Magnitude of Shear Stress on the San Andreas Fault: Implications of a Stress Measurement Profile at Shallow Depth
Authors: Zoback Mark D. , Roller John C.
Published: October 2006

A profile of measurements of shear stress perpendicular to the San Andreas fault near Palmdale, California, shows a marked increase in stress with distance from the fault. The pattern suggests that shear stress on the fault increases slowly with depth and reaches a value on the order of the average stress released during earthquakes. This result has important implications for both long- and short-term prediction of large earthquakes.
Early Hominid Population Densities: New Estimates
Authors: Boaz Noel T.
Published: October 2006

Proportional faunal representations in excavated fossil occurrences (Shungura Formation, Omo, Ethiopia) are very similar to modern sub-Saharan mammalian faunal proportions in a variety of environments. Early hominids comprise between 0.6 and 1.6 percent of the excavated assemblage, corrected to reflect numbers of individuals. With allochthonous faunal localities for comparison, direct analogies to modern fauna suggest early hominid population densities of between 0.006 to 1.7 individuals per square kilometer. Calculations based on population densities of modern large mammals indicate that population densities of early hominids were between 0.001 and 2.48 individuals per square kilometer.
Plasma Wave Observations Near Jupiter: Initial Results from Voyager 2
Authors: Gurnett D. A. , Kurth W. S. , Scarf F. L.
Published: October 2006

This report provides an initial survey of results from the plasma wave instrument on the Voyager 2 spacecraft, which flew by Jupiter on 9 July 1979. Measurements made during the approach to the planet show that low-frequency radio emissions from Jupiter have a strong latitudinal dependence, with a sharply defined shadow zone near the equatorial plane. At the magnetopause a new type of broadband electric field turbulence was detected, and strong electrostatic emissions near the upper hybrid resonance frequency were discovered near the low-frequency cutoff of the continuum radiation. Strong whistler-mode turbulence was again detected in the inner magnetosphere, although in this case extending out to substantially larger radial distances than for Voyager 1. In the predawn tail region, continuum radiation was observed extending down to extremely low frequencies, ∼ 30 hertz, an indication that the spacecraft was entering a region of very low density, ∼ 1.0 × 10
–5
per cubic centimeter, possibly similar to the lobes of Earth's magnetotail.
Terminal Cretaceous Extinction Scenario for a Catastrophe
Authors: Gartner Stefan , McGuirk James P.
Published: October 2006

All the biotic changes that occurred at the end of Cretaceous time, including the extinction of the dinosaurs, may be the result of a single terrestrial catastrophe. The Arctic spillover model, first proposed to explain the marine extinctions, would have caused a rapid and intense change in the earth's climate including a lowering of temperature and of precipitation. This change in climate may have triggered a series of ecological disasters that included the radical change in the distribution of vegetation on the earth as well as the extinction of the dinosaurs.
Tissue-Specific Splicing in Vivo of the β-Tropomyosin Gene: Dependence on an RNA Secondary Structure
Authors: Libri Domenico , Piseri Anna , Fiszman Marc Y.
Published: October 2006

The β-tropomyosin gene in chicken contains two mutually exclusive exons (exons 6A and 6B) which are used by the splicing apparatus in myogenic cells, respectively, before (myoblast stage) and after (myotube stage) differentiation. The myoblast splicing pattern is shown to depend on multiple sequence elements that are located in the upstream intron and in the exon 6B and that exert a negative control over exon 6B splicing. This regulation of splicing is due, at least in part, to a secondary structure of the primary transcript, which limits in vivo the accessibility of exon 6B in myoblasts.
Photoelectrochemistry
Authors: Bard Allen J.
Published: October 2006

The electron-hole pair formation that occurs at the interface between a semiconductor and a solution upon absorption of light leads to oxidation or reduction reactions of solution species. The principles of such photodriven processes are described as well as applications of semiconductors in electrochemical cells and as particulate systems for carrying out heterogeneous photocatalysis and photoelectrosynthesis.
Migrations of California Gray Whales Tracked by Oxygen-18 Variations in Their Epizoic Barnacles
Authors: Killingley J. S.
Published: October 2006

Barnacles attached to the California gray whale have oxygen isotope compositions that serve as a record of changing ocean temperatures as the whale migrates between arctic and subtropical waters. The isotopic values for the barnacles can be used to track whale migrations and to reconstruct the recent movements of beached whales. The method may be useful for tracing the movements of other animals, living or fossil, and for reconstructing the voyages of ancient ships.
The Climatological Significance of a Doubling of Earth's Atmospheric Carbon Dioxide Concentration
Authors: Idso Sherwood B.
Published: October 2006

The mean global increase in thermal radiation received at the surface of the earth as a consequence of a doubling of the atmospheric carbon dioxide content is calculated to be 2.28 watts per square meter. Multiplying this forcing function by the atmosphere's surface air temperature response function, which has recently been determined by three independent experimental analyses to have a mean global value of 0.113 K per watt per square meter, yields a value of ≤ 0.26 K for the resultant change in the mean global surface air temperature. This result is about one order of magnitude less than those obtained from most theoretical numerical models, but it is virtually identical to the result of a fourth experimental approach to the problem described by Newell and Dopplick. There thus appears to be a major discrepancy between current theory and experiment relative to the effects of carbon dioxide on climate. Until this discrepancy is resolved, we should not be too quick to limit our options in the selection of future energy alternatives.
Comment on Societal Risk
Authors: Okrent David
Published: October 2006

There is a need to measure societal risk more accurately; to examine and reevaluate our priorities in risk reduction; to determine the level of expenditure for risk reduction beyond which adverse economic and political effects may be overriding; and to develop a national approach to risk management.
Selenium Biomethylation Products from Soil and Sewage Sludge
Authors: Reamer D. C. , Zoller W. H.
Published: October 2006

Inorganic selenium compounds are converted to volatile methylated species (dimethyl selenide, dimethyl diselenide, and dimethyl selenone or methyl methylselenite) by microorganisms in sewage sludge and soil. In the absence of added selenium, no volatile selenium compounds were detected. All samples were evaluated without the addition of nutrients and in the presence of air or nitrogen. The methylation process may be an important step in the detoxification process for microorganisms exposed to high concentrations of selenium.
Rare Gas Isotopes in Hawaiian Ultramafic Nodules and Volcanic Rocks: Constraint on Genetic Relationships
Authors: Kaneoka Ichiro , Takaoka Nobuo
Published: October 2006

Differences in the rare gas isotopic ratios, especially the ratios of helium-3 to helium-4 and of argon-40 to argon-36, in Hawaiian ultramafic nodules and phenocrysts in volcanic rocks indicate that the nodules and phenocrysts were derived from different sources. The isotopic ratios in ultramafic nodules are similar to those in oceanic tholeiites. The phenocrysts seem to have formed in equilibrium with source materials richer in primordial components than those of the oceanic tholeiites. Mixing between the sources is quite likely.
Probing the Component Structure of a Maize Gene with Transposable Elements
Authors: Kermicle Jerry L.
Published: October 2006

Three instances of
R
gene instability were found in maize stocks carrying the controlling elements Dissociation (
Ds
) and Modulator (
Mp
). In each,
Ds
or a
Ds
-like element had transposed to
R
, inhibiting kernel pigmentation irregularly. When
Mp
was removed from the genome,
R
expression stabilized at low to intermediate levels. Strong pigmenting action was restored through recombination in heterozygotes of the three new forms with an
R
allele that specifies only plant pigmentation. The sites of
Ds
insertion mapped distal to the region that specifies seed versus plant expression. The evidence suggests that an
R
functional unit consists of one component that both governs tissue-specific expression and another that is common to alleles of different tissue-specific activities
Stars, Galaxies, Cosmos: The Past Decade, the Next Decade
Authors: Rubin Vera C.
Published: October 2006

Our perception of the universe has been altered by recent discoveries in astronomy, discoveries of new objects and of new phenomena, coming from a wide range of observing techniques. By 1990 astronomers expect to know more about the distribution of mass in the universe, the physics of energetic sources, and the intricate interconnections of astrophysical processes on a variety of spatial and temporal scales.
Crustacean Eye Fine Structure Seen with Scanning Electron Microscopy
Authors: Waterman Talbot H. , Pooley Alan S.
Published: October 2006

The internal fine structure of crustacean compound eyes has been reexamined with scanning electron microscopy. Several different preparative techniques were used in a comparative study of crab, crayfish, shrimp, and stomatopod eyes. The three-dimensional pattern of photoreceptive, dioptric, and screening components of these eyes has been directly demonstrated, and new insight has been gained into their functional organization. Particularly interesting in apposition eyes is the elaborate array of boundary membranes and protoplasmic strands linking the photoreceptive microvilli to their parent cell cytoplasm across the large intracellular vacuoles surrounding the axial rhabdom. Quantitative application of scanning electron microscopy to this system promises to advance our understanding of its proven high rate of receptor membrane turnover.
Aeromagnetic and Radio Echo Ice-Sounding Measurements Show Much Greater Area of the Dufek Intrusion, Antarctica
Authors: Behrendt John C. , Drewry David J. , Jankowski Edward , Grim Muriel S.
Published: October 2006

A combined aeromagnetic and radio echo ice-sounding survey made in 1978 in Antarctica over the Dufek layered mafic intrusion suggests a minimum area of the intrusion of about 50,000 square kilometers, making it comparable in size with the Bushveld Complex of Africa. Comparisons of the magnetic and subglacial topographic profiles illustrate the usefulness of this combination of methods in studying bedrock geology beneath ice-covered areas. Magnetic anomalies range in peak-to-trough amplitude from about 50 nanoteslas over the lowermost exposed portion of the section in the Dufek Massif to about 3600 nanoteslas over the uppermost part of the section in the Forrestal Range. Theoretical magnetic anomalies, computed from a model based on the subice topography fitted to the highest amplitude observed magnetic anomalies, required normal and reversed magnetizations ranging from 10
-3
to 10
-2
electromagnetic units per cubic centimeter. This result is interpreted as indicating that the Dufek intrusion cooled through the Curie isotherm during one or more reversals of the earth's magnetic field.
Gravitropism in Plant Stems May Require Ethylene
Authors: Wheeler Raymond M. , Salisbury Frank B.
Published: October 2006

Two inhibitors of ethylene synthesis in plants (cobaltous ion and aminoethoxyvinylglycine) and two inhibitors of ethylene action (silver ion and carbon dioxide) significantly delay the gravitropic response (upward bending) of mature dicot stems laid on their sides. This evidence suggests that ethylene may be required in the gravitropic response of shoots.
Radioactive Waste Storage Materials: Their α-Recoil Aging
Authors: Dran J. C. , Maurette M. , Petit J. C.
Published: October 2006

Ion implantation experiments suggest that the accumulation of α-recoil damage in radioactive waste storage materials, which behave like solid-state track detectors, plays a drastic role in their long-term degradation. The understanding of α-recoil "aging," overlooked in earlier studies, offers new guidelines for improving waste storage conditions.
Long-Range Atmospheric Transport of Soil Dust from Asia to the Tropical North Pacific: Temporal Variability
Authors: Duce R. A. , Unni C. K. , Ray B. J. , Prospero J. M. , Merrill J. T.
Published: October 2006

The concentration of airborne soil dust at Enewetak Atoll (11°N, 162°E) in April 1979 was 2.3 micrograms per cubic meter but decreased steadily to 0.02 microgram per cubic meter over the next 5 months. The spring dust is probably derived from China; its deposition rate (∼0.3 millimeter per 1000 years) suggests that it may be a significant contributor to the deep-sea sediments of the North Pacific.
Ecology of Colors of Firefly Bioluminescence
Authors: Lall Abner B. , Seliger Howard H. , Biggley William H. , Lloyd James E.
Published: October 2006

Dark-active North American fireflies emit green bioluminescence and dusk-active species emit yellow, in general. Yellow light and yellow visual spectral sensitivity may be adaptations to increase the signal-to-noise (that is, foliage-reflected ambient light) ratio for sexual signaling during twilight. The peaks of the electroretinogram visual spectral sensitivities of four species tested, two dark- and two dusk-active, correspond with the peak of their bioluminescent emissions.
Evolution of Clutch Size in Birds: Adaptive Variation in Relation to Territory Quality
Authors: Högstedt Göran
Published: October 2006

Reproductive output from enlarged or reduced magpie broods showed that each female generally lays a clutch of optimal size. This size varies considerably between females. Approximately 85 percent of the within-years variation in clutch size was associated with differences between territories. Colonial bird species, lacking individual foraging territories, have a smaller clutch size variation than territorial species.
Observations of a Probable Change in the Solar Radius Between 1715 and 1979
Authors: Dunham David W. , Sofia Sabatino , Fiala Alan D. , Herald David , Muller Paul M.
Published: October 2006

Solar eclipses were observed from locations near both edges of the paths of totality in England in 1715, in Australia in 1976, and in North America in 1979. Analysis of these observations shows that the solar radius has contracted by 0.34 ± 0.2 arc second in 264 years.
Isolation of a cDNA from the Virus Responsible for Enterically Transmitted Non-A, Non-B Hepatitis
Authors: Reyes Gregory R. , Purdy Michael A. , Kim Jungsuh , Luk Ka-Cheung , Young LaVonne M. , Fry Kirk E. , Bradley Daniel W.
Published: October 2006

Major epidemic outbreaks of viral hepatitis in underdeveloped countries result from a type of non-A, non-B hepatitis distinct from the parenterally transmitted form. The viral agent responsible for this form of epidemic, or enterically transmitted non-A, non-B hepatitis (ET-NANBH), has been serially transmitted in cynomolgus macaques (cynos) and has resulted in typical elevation in liver enzymes and the detection of characteristic virus-like particles (VLPs) in both feces and bile. Infectious bile was used for the construction of recombinant complementary DNA libraries. One clone, ET1.1, was exogenous to uninfected human and cyno genomic liver DNA, as well as to genomic DNA from infected cyno liver. ET1.1 did however, hybridize to an approximately 7.6-kilobase RNA species present only in infected cyno liver. The translated nucleic acid sequence of a portion of ET1.1 had a consensus amino acid motif consistent with an RNA-directed RNA polymerase; this enzyme is present in all positive strand RNA viruses. Furthermore, ET1.1 specifically identified similar sequences in complementary DNA prepared from infected human fecal samples collected from five geographically distinct ET-NANBH outbreaks. Therefore, ET1.1 represents a portion of the genome of the principal viral agent, to be named hepatitis E virus, which is responsible for epidemic outbreaks of ET-NANBH.
Noble Gases in Stratospheric Dust Particles: Confirmation of Extraterrestrial Origin
Authors: Hudson B. , Flynn G. J. , Fraundorf P. , Hohenberg C. M. , Shirck J.
Published: October 2006

Noble gas elemental and isotopic ratios were measured in a group of 13 "chondritic" stratospheric dust particles. Neon and argon are present in "solar" proportions; xenon appears to be dominated by contributions from "planetary" sources. The apparent xenon concentration is higher than that measured in any bulk meteorite, approaching the concentration found in the noble gas-rich, acid-insoluble residues from carbonaceous chondrites.
Three-Dimensional Methods in Seismic Exploration
Authors: Graebner Robert , Wason Cam , Meinardus Hans
Published: October 2006

Two-dimensional seismic prospecting methods are inadequate to solve the three-dimensional geological problems that arise in petroleum exploration. The three-dimensional seismic technique is a data collection and processing system that samples the subsurface adequately. The structure and lithology of rocks are mapped accurately by imaging their acoustic reflectivity with the scalar wave equation. In oil industry economics, the expense of three-dimensional seismic methods is justified by their usefulness for discovering additional reserves and for reducing the growing costs of developing oil and gas fields.
Measurements of Cloud Condensation Nuclei in the Stratosphere Around the Plume of Mount St. Helens
Authors: Rogers C. F. , Hudson J. G. , Kocmond W. C.
Published: October 2006

Measurements of cloud condensation nuclei were made from small samples of stratospheric air taken from a U-2 aircraft at altitudes ranging from 13 to 19 kilometers. The measured concentrations of nuclei both in and outside the plume from the May and June 1980 eruptions of Mount St. Helens were higher than expected, ranging from about 100 to about 1000 per cubic centimeter active at 1 percent supersaturation.
Filter Measurements of Stratospheric Sulfate and Chloride in the Eruption Plume of Mount St. Helens
Authors: Gandrud B. W. , Lazrus A. L.
Published: October 2006

Five flights of the U-2 aircraft with a filter sampler aboard were flown in the Mount St. Helens debris from 19 May to 17 June 1980. Sulfate concentrations as large as 216 times the expected background were observed. The enhancements of acid chloride vapor were considerably smaller, suggesting an insignificant increase of background values of hydrogen chloride once the plume is well mixed throughout the lower stratosphere.
Trace Element Composition of the Mount St. Helens Plume: Stratospheric Samples from the 18 May Eruption
Authors: Vossler Teri , Anderson David L. , Aras Namik K. , Phelan Janet M. , Zoller William H.
Published: October 2006

Atmospheric particulate material collected from the stratosphere in the plume of the 18 May 1980 eruption of the Mount St. Helens volcano was quite similar in composition to that of ash that fell to the ground in western Washington. However, there were small but significant differences in concentrations of some elements with altitude, indicating that the stratospheric material was primarily produced from fresh magma, not fragments of the mountain.
Extended Family System in a Communal Bird
Authors: Brown Jerram L. , Brown Esther R.
Published: October 2006

The genealogical structure of an extended family system in a nonprimate species is described. In Mexican jays, social units are more complex genealogically than in most other communal birds and may contain grandparents, uncles, aunts, and cousins in addition to parents and older siblings. The average relatedness within the units varies greatly, and is lower than would be expected for a highly social bird.