bluuebunny/crossref_metadata_2025 huggingface dataset:
Oil and Gas in Offshore Tracts: Estimates Before and After Drilling
Authors: Uman Myron F. , James William R. , Tomlinson Holly R.
Published: October 2006

Estimates of volumes of recoverable hydrocarbons underlying offshore tracts are made by the U.S. Geological Survey prior to the sale of leases and after drilling on those leases. Comparisons of these estimates show a moderate positive correlation and no evidence for relative bias, although the precision of the predictions is quite limited.
Changed Lyotropic Liquid Crystalline Structure Due to Polymerization of the Amphiphilic Component
Authors: Friberg Stig E. , Thundathil Raju , Stoffer James O.
Published: October 2006

Optical patterns in polarized light and x-ray reflections in the low-angle region were used to detect a shift from one liquid crystalline structure to another during polymerization. The polymerization took place in a lyotropic liquid crystal of water and sodium undecenoate, with a structure consisting of cylinders in a two-dimensional hexagonal close packing. After polymerization, a lamellar liquid crystalline structure was obtained.
Disaster, Catastrophe, and Local Persistence of the Sea Palm
Postelsia palmaeformis
Authors: Paine R. T.
Published: October 2006

Two components of natural disturbance, its local intensity and frequency beyond a threshold level, limit a marine benthic alga to wave-swept shores. Transplant experiments indicate that the limited distribution is not due to physiological restriction. Instead, it requires predictable annual disturbance of moderate intensity for local persistence.
Molecular Thermodynamics for Chemical Process Design
Authors: Prausnitz J. M.
Published: October 2006

Chemical process design requires quantitative information on the equilibrium properties of a variety of fluid mixtures. Since the experimental effort needed to provide this information is often prohibitive in cost and time, chemical engineers must utilize rational estimation techniques based on limited experimental data. The basis for such techniques is molecular thermodynamics, a synthesis of classical and statistical thermodynamics, molecular physics, and physical chemistry.
Isolation of a Deep-Sea Barophilic Bacterium and Some of Its Growth Characteristics
Authors: Yayanos A. Aristides , Dietz Allan S. , Boxtel R. Van
Published: October 2006

A bacterium, a spirillum, has been isolated from a deep-sea sample and has been found to grow optimally at about 500 bars and 2° to 4°C. These conditions are similar to those prevailing at the 5700-meter depth from which the sample was collected. The organism grows at these pressures and temperatures with a generation time of between 4 and 13 hours; at atmospheric pressure and 2° to 4°C, the generation time is about 3 to 4 days.
On the Global Distribution of Aerosols
Authors: Hogan A. W. , Mohnen V. A.
Published: October 2006

Aerosol concentrations were measured during a 54-hour circumnavigation of the earth at altitudes between 238 and 162 millibars and concurrently by a separate flight at lower altitudes over the Pacific Ocean. The aerosol concentrations were found to be symmetrically distributed about the earth. Concurrent meteorological measurements indicate that tropospheric aerosols enter the stratosphere in the vicinity of jet streams and that surface aerosols are carried aloft over the intertropical convergence and Antarctic polar front.
Chemotactic Antibody
Authors: Isturiz Martin A. , Sandberg Ann L. , Schiffmann Elliott , Wahl Sharon M. , Notkins Abner Louis
Published: October 2006

Antibody of the immunoglobulin G class to herpes simplex virus and antibody of the immunoglobulin M class to sheep red blood cells were coupled to the synthetic peptide formylmethionylleucylphenylalanine (fMet-Leu-Phe), which is chemotactic for both mononuclear and polymorphonuclear leukocytes. The resulting molecules were chemotactic and retained their antigen-binding activity. When antibodies coupled to fMet-Leu-Phe were incubated with antigen, the resulting immune complexes were also chemotactic. Chemotactic antibody may provide a potent means of enhancing the migration of inflammatory cells to specific sites.
Microbodies in Germinating Fern Spores: Evidence for Glyoxysomal Activity
Authors: DeMaggio A. E. , Greene Carolyn , Unal Serap , Stetler David A.
Published: October 2006

Enzymes of the glyoxylate cycle, isocitrate lyase and malate synthase, are active during the germination of spores of the fern
Dryopteris filix-mas.
Increases in activity of both enzymes are correlated with the breakdown of lipid reserves. The occurrence of these enzymes suggests that the microbodies previously described in these spores are glyoxysomes
.
Sex Discrimination in
Gerris remigis
: Role of a Surface Wave Signal
Authors: Wilcox R. Stimson
Published: October 2006

Even when blinded with masks, adult male water striders (
Gerris remigis
) accurately ascertain the sex of other adult water striders in the laboratory. Freely moving females that were artificially made to play back computer-generated male surface wave and body-contact signals of about 90 waves per second were treated as males by the masked males and as females when no such playbacks were made. Thus, the males can use presence or absence of the male signal as the sole means for sex discrimination.
A Meteoritic Component Rich in Volatile Elements: Its Characterization and Implications
Authors: Ganapathy R. , Larimer J. W.
Published: October 2006

An unusual carbon-rich material found in the Abee meteorite is highly enriched in volatile elements, by factors of 10
4
relative to the case for nonvolatile elements. Volatile-rich material of this type might form in the solar nebula toward the end of accretion, when small amounts of residual dust acquire all the uncondensed volatile elements. The mercury enrichment factor of 8500 could explain the paradox of the excess abundance of this element in meteorites.
Viscous Flow Circulation of the Solar Wind Behind Venus
Authors: Pérez-de-Tejada H.
Published: October 2006

A latitudinal circulation model of solar wind flow in the near wake of Venus is presented. It is shown that solar wind fluxes entering through the polar terminator can be viscously forced to lower latitudes. The resulting motion produces a downstream elongation of the nightside polar ionosphere out to the downstream extension of the middle- and low-latitude ionopause. The geometry suggested by this flow circulation model provides a simple explanation of the ionospheric bulge inferred from the Pioneer Venus observations.
Is the Sun Shrinking?
Authors: Shapiro Irwin I.
Published: October 2006

Observations of 23 transits of Mercury in front of the sun between 1736 and 1973 show no indication of any significant change in the diameter of the sun. Regression analysis yields a decrease of the angular diameter, as viewed from the earth, of under 0.3 arc second per century (> 90 percent confidence limit). This limit is incompatible with the 2 arc seconds per century decrease obtained by Eddy for the equatorial diameter from direct observations made at the Greenwich Observatory and at the U.S. Naval Observatory.
Breeder Reactors in France
Authors: Zaleski C. Pierre
Published: October 2006

France relies on nuclear power as an important part of her energy program. Anticipating problems with the availability of natural uranium before the year 2020, the French have been pursuing a three-stage program of development of breeder reactors. The third reactor in this program, the near-commercial plant Super Phenix Mark I, is expected to reach power operation in 1983. Although there are still some uncertainties, particularly about the date when the breeder will become competitive with other energy sources, the outlook is considered favorable and preliminary designs for commercial plants are under way.
Crustal Structure of the Northeastern United States: Contrasts Between Grenville and Appalachian Provinces
Authors: Taylor Steven R. , Toksöz M. Nafi , Chaplin Michael P.
Published: October 2006

Average crustal models for the northeastern United States are computed on the basis of the travel times of P and S waves from regional earthquakes. The Precambrian Grenville Province in New York State has a relatively homogeneous crust. The Paleozoic New England Appalachians have a well-defined, two-layer crust that is slightly thicker and shows a high-velocity lower layer relative to the Grenville. A time-term analysis based on P
n
data (waves refracted from the Moho) shows that a relatively thick or low-velocity crust parallels northeast-trending geologic structures in central New England. The observed differences between the two orogenic belts may reflect contrasts in their tectonic evolution.
Aragonite Twinning in the Molluscan Bivalve Hinge Ligament
Authors: Marsh Mary E. , Sass Ronald L.
Published: October 2006

Molluscan bivalve hinge ligaments are composed of long needle-shaped aragonite crystals embedded in a protein matrix. These crystals are twinned and, in general, the twin forms a thin lamella through the center of the crystal.
Intrafloral Pollen Differentiation in the New World Lecythidaceae, Subfamily Lecythidoideae
Authors: Mori Scott Alan , Orchard John Eric , Prance Ghillean Tolmie
Published: October 2006

Floral biology, pollen germination, and scanning electron microscopy studies have indicated different types of pollen within the same flower in at least two species of New World Lecythidaceae, subfamily Lecythidoideae. Two types of pollen are produced in different parts of the androecium and serve different functions. One type attracts pollinators by providing a reward, and the other functions in fertilization. The former type has lost its ability to germinate, at least under in vitro conditions.
Seabed Minerals and the Law of the Sea
Authors: McKelvey V. E.
Published: October 2006

If, as seems likely, a comprehensive law-of-the-sea treaty is successfully concluded, minerals of the continental margins would be almost entirely controlled by coastal nations, and the right to produce minerals of the deep ocean floor would be licensed by an International Seabed Authority. Mineral production from the continental margins is likely to increase and diversify with time. The only minerals from the deep ocean floor for which there are reasonably good prospects of production within the next decade are the metalliferous muds from some of the deeps in the Red Sea (which lie within what is likely to be the jurisdiction of Saudi Arabia and Sudan) and nodules in the northeastern equatorial Pacific that contain recoverable metals, namely nickel, copper, cobalt, and possibly manganese, molybdenum, and vanadium.
Subsurface Circulation in the Somali Current
Authors: Leetmaa A. , Rossby H. T. , Saunders P. M. , Wilson P.
Published: October 2006

Direct velocity measurements were made at intermediate depths along the East African coast from March to July 1979. Strong time-dependent flows with multiple reversals in direction were found in the upper 1000 meters between 3° N and 4° S. At 700 meters, there may be a connection between the southwestward coastal current and an equatorial jet observed at 49° E, the latter turning south near the coast. North of 3° N little spatial organization of the flow can be recognized.
Evolution of Sea Surface Temperature in the Somali Basin During the Southwest Monsoon of 1979
Authors: Brown O. B. , Bruce J. G. , Evans R. H.
Published: October 2006

Satellite and research vessel observations of sea surface temperature during the southwest monsoon of 1979 show the development of large wedge-shaped areas of cold water along the Somali coast at both 5° and 10°N during June and July. The cold water associated with the large northern and southern Somali eddy systems could be traced several hundred kilometers offshore. By late August the cold wedge at 5°N translated northeastward as far as 10°N at speeds of 15 to 30 centimeters per second, indicating a coalescence of the systems.
Federal Funding in Materials Research
Authors: Ling James G. , Hand Mary Ann
Published: October 2006

The performance of the 20 materials research laboratories (MRL's) at universities funded with institutional grants by the National Science Foundation, Department of Energy, and National Aeronautics and Space Administration is evaluated in comparison with 15 other universities (non-MRL's) receiving individually funded projects for materials research. Performance is measured by peer review and citation frequency analysis of publications, subjective evaluation of research achievements and researcher reputation by a panel of experts, review of equipment purchases and utilization, and analysis of administrative costs. The study concludes that there are no significant differences between the MRL's and non-MRL's with respect to innovation, interdisciplinarity, utilization of specialized equipment, concentration of funding, rate of turnover, duration of research areas, and level of effort per research paper. The MRL's have a greater number of major achievements and attract researchers with higher reputations. The MRL's tend to emphasize experimental work, and in about 70 percent of the materials research areas sponsored by the National Science Foundation there is no overlap between the two groups. Institutional grants involve much less total (federal plus university) administrative cost per grant dollar than project grants.
2-Aminoethylphosphonic Acid Metabolism During Embryonic Development of the Planorbid Snail
Helisoma
Authors: Miceli Michael V. , Henderson Thomas O. , Myers Terrell C.
Published: October 2006

In freshly laid egg masses of
Helisoma
sp., more than 95 percent of the phosphorus is found in alkylphosphonic acids, as determined by phosphorus-31 nuclear magnetic resonance spectroscopy. These compounds are metabolized during embryonic development, as shown by differential acid hydrolysis and experiments with phosphorus-33-labeled phosphoric acid. Further, nuclear magnetic resonance spectroscopy indicates phosphonic acid involvement in related snail families, including the schistosomal vector
Biomphalaria glabrata
.
Carbynes in Meteorites: Detection, Low-Temperature Origin, and Implications for Interstellar Molecules
Authors: Hayatsu Ryoichi , Scott Robert G. , Studier Martin H. , Lewis Roy S. , Anders Edward
Published: October 2006

Carbon from the Allende meteorite is not graphite but carbyne (triply bonded elemental carbon), inasmuch as on heating to 250° to 330° C it releases mainly triply bonded fragments: –(C≡C)

n

,– with
n
= 1 to 5, and –(C≡C)

n

–CN, with
n
= 1 to 3. Although carbynes have been known to form only by condensation of carbon vapor above 2600 K or by explosive shock of > 600 kilobars, it is found that they also form metastably by the reaction 2CO → CO
2
+ C (solid) at 300° to 400° C in the presence of a chromite catalyst. Such low-temperature formation by surface catalysis may be the dominant source of carbynes on the earth and in meteorites, and a major source of interstellar carbynes and cyanopolyacetylenes.
Geoidal Change and Shore-Level Tilt Along Holocene Estuaries: Sénégal River Area, West Africa
Authors: Faure H. , Fontes J. C. , Hebrard L. , Monteillet J. , Pirazzoli P. A.
Published: October 2006

An expedition under "Projet Rhéomarge" traced marine deposits along the Sénégal estuary. Leveled and dated samples have made it possible to reconstruct portions of paleogeoids of 6500, 5500, and 1800 years before present. The surfaces of these geoids show that the tilt across continental margins predicted by mathematical models is less than 1 meter from the coast to 120 kilometers inland.
Liquid-Phase Dehydration of Aqueous Ethanol-Gasoline Mixtures
Authors: Fanta George F. , Burr Robert C. , Orton William L. , Doane William M.
Published: October 2006

Two-phase mixtures of gasoline, water, and ethanol were dehydrated with both starch and saponified starch-
g
-polyacrylonitrile (HSPAN). Whereas starch absorbed ethanol as well as water, HSPAN selectively absorbed the water component, allowing ethanol to dissolve in the gasoline phase.
Sequence of Pumiceous Tephra Layers and the Late Quaternary Environmental Record Near Mount St. Helens
Authors: Heusser Calvin J. , Heusser Linda E.
Published: October 2006

Tephra in lake beds within 40 kilometers of Mount St. Helens was deposited an average of once every 2,700 years over the past 35,000 years, for a total of 13 layers. Times of deposition span the period of the Fraser Glaciation and intervals before and after it, and include the series of climates prevailing when vegetation west of the Cascade Range shifted between a park-tundra type and the modern western hemlock forest.
A Three-Band Hand-Held Radiometer for Field Use
Authors: Tucker Compton J. , Jones William H. , Kley William A. , Sundstrom Gunnar J.
Published: October 2006

A self-contained, hand-held radiometer designed for field use has been constructed and tested. The 4.5-kilogram device, consisting of a strap-supported electronics module and a hand-held probe containing three sensors, is powered by flashlight and transistor radio batteries, uses two silicon and one lead sulfide detector, has three liquid-crystal displays, features sample-and-hold radiometric sampling, and is spectrally configured to Landsat-D's thematic mapper bands TM3 (0.63 to 0.69 micrometer), TM4 (0.76 to 0.90 micrometer), and TM5 (1.55 to 1.75 micrometers). The device was designed to collect ground-truth data for the thematic mapper and to facilitate ground-based, remote-sensing studies of natural materials in situ. Prototype instruments were extensively tested under laboratory and field conditions, with satisfactory results.
Natural Disturbance and the Steady State in High-Altitude Balsam Fir Forests
Authors: Sprugel Douglas G. , Bormann F. H.
Published: October 2006

Wind-induced, cyclic waves of death, regeneration, and maturation constantly move through the high-altitude balsam fir forests in the northeastern United States. Biomass and productivity relations, species diversity, and nutrient cycling patterns are closely tied to this cycle of disturbance. Disturbance is thus an integral part of the long-term maintenance of this ecosystem. Since forests of this type normally include all phases of the disturbance-regeneration cycle, they may constitute a steady-state ecosystem in equilibrium with the surrounding environment.
Anabaseine: Venom Alkaloid of
Aphaenogaster
Ants
Authors: Wheeler J. W. , Olubajo O. , Storm C. B. , Duffield R. M.
Published: October 2006

Anabaseine, a tobacco alkaloid, is identified as a poison gland product in
Aphaenogaster
ants, in which it functions as an attractant.
Sex-Biased Litter Reduction in Food-Restricted Wood Rats (
Neotoma floridana
)
Authors: McClure Polley Ann
Published: October 2006

Mothers of eastern wood rats (
Neotoma floridana
) normally invest their lactation energy equally in male and female offspring, but alter that investment when their food is severely restricted during lactation. The effect of the altered investment is a significant bias against males in both mortality and growth.
Reworked Neritic Fossils in Upper Mesozoic and Cenozoic Central Pacific Deep-Sea Sediments Monitor Sea-Level Changes
Authors: Thiede Jørn
Published: October 2006

Upper Mesozoic and Cenozoic pelagic sediments in the central Pacific Ocean contain occasional horizons with reworked and displaced fossils produced by organisms that once lived in neritic shallow-water environments. The flux of neritic fossils was restricted to eight intervals of low eustatic sea level during Late Mesozoic and Cenozoic times. They were eroded from shoals along the flanks of volcanic highs which often supported tropical islands and which since then have subsided.
Cell Alignment Required in Differentiation of
Myxococcus xanthus
Authors: Kim Seung K. , Kaiser Dale
Published: October 2006

During fruiting body morphogenesis of
Myxococcus xanthus
, cell movement is required for transmission of C-factor, a short range intercellular signaling protein necessary for sporulation and developmental gene expression. Nonmotile cells fail to sporulate and to express C-factor-dependent genes, but both defects were rescued by a simple manipulation of cell position that oriented the cells in aligned, parallel groups. A similar pattern of aligned cells normally results from coordinated recruitment of wild-type cells into multicellular aggregates, which later form mature fruiting bodies. It is proposed that directed cell movement establishes critical contacts between adjacent cells, which are required for efficient intercellular C-factor transmission.
Soil as a Sink for Atmospheric Carbon Monoxide
Authors: Bartholomew Gene W. , Alexander Martin
Published: October 2006

The rate of carbon monoxide oxidation by soil increased with increasing carbon monoxide concentration in the gas phase, in line with Michaelis-Menten kinetics. Rates of carbon monoxide oxidation were determined for 20 soils at 0°, 10°, 20°, and 30°C. The observed oxidation rates were used to calculate a global soil uptake rate of atmospheric carbon monoxide of 4.1 × 10
14
grams per year, which is slightly less than the amount of carbon monoxide believed to be produced annually as a result of fossil fuel combustion.
Photovoltaics
Authors: Smith Jeffrey L.
Published: October 2006

The federal government has sponsored a program of research and development on terrestrial photovoltaic systems that is designed to reduce the costs of such systems through technological advances. There are many potential paths to lower system costs, and successful developments have led to increased private investment in photovoltaics. The prices for photovoltaic collectors and systems that appear to be achievable within this decade offer hope that the systems will soon be attractive in utility applications within the United States. Most of the advances achieved will also be directly applicable to the remote markets in which photovoltaic systems are now commercially successful.
Environmental Sex Determination: Interaction of Temperature and Genotype in a Fish
Authors: Conover David O. , Kynard Boyd E.
Published: October 2006

Sex determination in an atherinid fish, the Atlantic silverside (
Menidia menidia
), is under the control of both genotype and temperature during a specific period of larval development. The sex ratios of the progeny of different females are variable and differ in their responsiveness to temperature. This demonstrates that sex ratio in fishes that normally have separate sexes can be influenced by the environment.
Atomic Clouds as Distributed Sources for the Io Plasma Torus
Authors: Brown R. A. , Ip W.-H.
Published: October 2006

Several recent developments have implications for the neutral particle environment of Jupiter. Very hot sulfur ions have been detected in the Io torus with gyrospeeds comparable to the corotation speed, a phenomenon that would result from a neutral sulfur cloud. Current evidence supports the hypothesis that extensive neutral clouds of oxygen and sulfur exist in the Jupiter magnetosphere and that they are important sources of ions and energy for the Io torus.
Tunguska Meteor Fall of 1908: Effects on Stratospheric Ozone
Authors: Turco R. P. , Toon O. B. , Park C. , Whitten R. C. , Pollack J. B. , Noerdlinger P.
Published: October 2006

In 1908, when the giant Tunguska meteor disintegrated in the earth's atmosphere over Siberia, it may have generated as much as 30 million metric tons of nitric oxide (NO) in the stratosphere and mesosphere. The photochemical aftereffects of the event have been simulated using a comprehensive model of atmospheric trace composition. Calculations indicate that up to 45 percent of the ozone in the Northern Hemisphere may have been depleted by Tunguska's nitric oxide cloud early in 1909 and large ozone reductions may have persisted until 1912. Measurements of atmospheric transparency by the Smithsonian Astrophysical Observatory for the years 1909 to 1911 show evidence of a steady ozone recovery from unusually low levels in early 1909, implying a total ozone deficit of 30 ± 15 percent. The coincidence in time between the observed ozone recovery and the Tunguska meteor fall indicates that the event may provide a test of current ozone depletion theories.
Mechanism of Single-Layer Graphite Oxidation: Evaluation by Electron Microscopy
Authors: Yang Ralph T. , Wong Chop
Published: October 2006

Etch-decoration reveals that the rate of removal of carbon atoms exposed at monolayer steps on graphite surfaces depends on the population density of these edge atoms (the rate is higher at a low-density surface) and that carbon removal continues for a prolonged period after the oxygen supply in the gas phase has been shut off. The edge carbons are removed by both oxygen from the gas phase and oxygen in the adsorbed oxides which migrate from the neighboring basal carbon atoms.
Acoustic Communication and Reproductive Isolation in Two Species of Wolf Spiders
Authors: Stratron Gail E. , Uetz George W.
Published: October 2006

Sound production by male wolf spiders during courtship is critical for behavioral reproductive isolation of two sibling species. Females only respond to and copulate with conspecific males, and acoustic signals through a substrate are necessary to induce receptivity. No reproductive barriers that could arise during mating (such as genital or mechanical incompatibility) or after mating (infertility) are in effect between the species, since forced interspecific matings produce viable offspring.
Hanford-Derived Plutonium in Columbia River Sediments
Authors: Beasley T. M. , Ball L. A. , Andrews J. E. , Halverson J. E.
Published: October 2006

Mass spectrometry data on plutonium isolated from Columbia River sediments exhibit mean ratios of plutonium-240 to plutonium-242 consistent with those observed for integrated global fallout. Ratios of plutonium-240 to plutonium-239 show marked deviations from accepted fallout values, suggesting a second source of plutonium-239. This additional plutonium-239 arises from the decay of neptunium-239 produced in reactor effluent water from the old plutonium production reactors located on the Hanford Reservation. An estimated 20 to 25 percent of the total plutonium inventory in sediments behind McNary Reservoir, the first downriver site of fine sediment accumulation below the Hanford Reservation, is ascribed to reactor operations.
Stephanopogon
, a Phylogenetically Important "Ciliate," Shown by Ultrastructural Studies to Be a Flagellate
Authors: Lipscomb Diana L. , Corliss John O.
Published: October 2006

A benthic marine protist
(Stephanopogon)
with a homokaryotic nucleus has long been considered to be a gymnostome ciliate. It has been important in hypotheses concerning the origin of ciliates, the evolution and origin of the dual nuclear apparatus of contemporary species of the Ciliophora, and the origin of the multicellular Eumetazoa. Ultrastructural observations reveal that the organism should be reclassified as a flagellate, despite its superficial resemblance to ciliates
.
Differential Lead Retention in Zircons: Implications for Nuclear Waste Containment
Authors: Gentry Robert V. , Sworski Thomas J. , McKown Henry S. , Smith David H. , Eby R. E. , Christie W. H.
Published: October 2006

An innovative ultrasensitive technique was used for lead isotopic analysis of individual zircons extracted from granite core samples at depths of 960, 2170, 2900, 3930, and 4310 meters. The results show that lead, a relatively mobile element compared to the nuclear waste-related actinides uranium and thorium, has been highly retained at elevated temperatures (105° to 313°C) under conditions relevant to the burial of synthetic rock waste containers in deep granite holes.
Pheromone Source Location by Flying Moths: A Supplementary Non-Anemotactic Mechanism
Authors: Baker Thomas C. , Kuenen L. P. S.
Published: October 2006

After the wind was stopped in an insect flight tunnel, male oriental fruit moths continued to fly in zigzag fashion along a stationary pheromone plume. Their lateral excursions from the time-averaged pheromone plume were no greater without wind than in wind of 38 centimeters per second. When the pheromone plume was removed and the wind stopped, males initiated wider track reversals when they reached the pheromone-free area in still air than they had made while in the pheromone plume. This non-anemotactic mechanism of maintaining plume contact—possibly a special kind of klinotaxis—when coupled with the orthokinetic retinal velocity of apparent ground pattern motion, allowed males to reach the pheromone source area from 1 to 2 meters away without wind.
Skeleton of
Diacodexis
, Oldest Known Artiodactyl
Authors: Rose Kenneth D.
Published: October 2006

A nearly complete skeleton of early Eocene
Diacodexis
the oldest known member of the mammalian order Artiodactyla, is described. Its slender, elongate limb elements indicate that
Diacodexis
was highly cursorial and closer in postcranial adaptations to tragulids and other primitive ruminants than to living or extinct nonruminant artiodactyls. Its skeletal specializations call into question the widespread notion that
Diacodexis
was the ancestor of all later artiodactyls.
Juvenile-Adult Habitat Shift in Permian Fossil Reptiles and Amphibians
Authors: Bakker Robert T.
Published: October 2006

Among extant large reptiles, juveniles often occupy different habitats from those of adults or subadults and thus avoid competition with and predation from the older animals; small juveniles often choose cryptic habitats because they are vulnerable to a wide variety of predators. Evidence from fossil humeri and femora of Early Permian reptiles collected from sediments of several distinct habitats indicate that similar shifts in habitat occurred. Juvenile
Dimetrodon
seem to have favored cryptic habitats around swamp and swampy lake margins; adults favored open habitats on the floodplains. Similar patterns of habitat shift seem to be present in the reptile
Ophiacodon
and the amphibian
Eryops
and may have been common in fossil tetrapods of the Permian-Triassic.
Great Sand Sea and Selima Sand Sheet, Eastern Sahara: Geochronology of Desertification
Authors: Haynes C. Vance
Published: October 2006

The relation of playa sediments and associated archeological sites with longitudinal dunes allows estimation of ages for the two uppermost strata of the Great Sand Sea. Active dune formation corresponds with interpluvial periods of hyperaridity; dune stability corresponds with semiarid pluvial periods. Archeological sites associated with truncated paleosols in the Selima Sand Sheet suggest a similar climatic relation and indicate that the isohyets of central Sudan shifted at least 400 kilometers northward during the peak of pluvials.
Remote Acoustic Detection of a Turbidity Current Surge
Authors: Hay Alex E. , Burling R. W. , Murray J. W.
Published: October 2006

A turbidity current surge has been detected in a leveed submarine channel in Rupert Inlet, British Columbia, with the use of acoustic sounders operating at 42.5, 107, and 200 kilohertz.
Nickel for Your Thoughts: Urey and the Origin of the Moon
Authors: Brush Stephen G.
Published: October 2006

The theories of Harold C. Urey (1893-1981) on the origin of the moon are discussed in relation to earlier ideas, especially George Howard Darwin's fission hypothesis. Urey's espousal of the idea that the moon had been captured by the earth and has preserved information about the earliest history of the solar system led him to advocate a manned lunar landing. Results from the Apollo missions, in particular the deficiency of siderophile elements in the lunar crust, led him to abandon the capture selenogony and tentatively adopt the fission hypothesis.
Paleodictyon
: The Traces of Infaunal Xenophyophores?
Authors: Swinbanks D. D.
Published: October 2006

A xenophyophore found just below the surface of a box core of modern deep-sea sediment from the Japan Trench has a threadlike plasma body that extends through horizontal, anastomosing networks of organically bound sediment tubes (the organism's test). The tubes resemble some of the polygonal networks of the trace fossil
Paleodictyon
. Such xenophyophores may be the makers of
Paleodictyon
, and the complex, regular geometry of
Paleodictyon
may be determined by the xenophyophore's anastomosing body shape.
Crystalline Todorokite Associated with Biogenic Debris in Manganese Nodules
Authors: Siegel Malcolm D. , Turner Shirley
Published: October 2006

Platy intergrowths of crystalline todorokite are associated with biogenic debris in the cores of manganese nodules from a site in the Pacific Ocean. Analyses by electron diffraction and transmission electron microscopy demonstrate that this material is composed of tunnels of chains of linked MnO
6
octahedra. The chemical composition, morphology, and stability of the todorokite differ from those of nickel- and copper-rich manganese oxides in nodules that have been identified as todorokite or buserite in earlier investigations.
Bacterial, Viral, and Fungal Insecticides
Authors: Miller Lois K. , Lingg A. J. , Bulla Lee A.
Published: October 2006

Microorganisms that are pathogenic to insects provide a wealth of biological material that can be exploited by humans to control insect pests. Innovative applications of a few such entomopathogens are found throughout the world, but widespread commercial production of microbial insecticides awaits further studies of the biology, ecology, and pathogenicity of the agents. Genetic engineering techniques may be used to increase the virulence of these microorganisms, as well as to make them more tolerant of physical and chemical conditions and perhaps to broaden their host ranges. The use of microbial insecticides could decrease our dependence on chemical pesticides.
Peroxidase-Catalyzed Removal of Phenols from Coal-Conversion Waste Waters
Authors: Klibanov Alexander M. , Tu Tsu-Man , Scott Kevin P.
Published: October 2006

A novel, enzymatic approach has been developed for the removal of phenols from coal-conversion aqueous effluents. Treatment with horseradish peroxidase and hydrogen peroxide precipitates 97 to 99 percent of the phenol in a wide range of
p
H and phenol concentrations; both model mixtures and real industrial waste-water samples have been treated successfully. Other pollutants, such as polychlorinated biphenyls, can be enzymatically coprecipitated with the phenols.
Ediacaran (Precambrian) Fossils from the Wernecke Mountains, Northwestern Canada
Authors: Hofmann H. J. , Fritz W. H. , Narbonne G. M.
Published: October 2006

Fossil medusoids identified as
Cyclomedusa davidi?
,
Beltanelliformis brunsae
, and cf.
Sekwia excentrica
are reported from Late Precambrian strata in the Wernecke Mountains. They are representatives of the Ediacaran fauna, the oldest assemblage of cosmopolitan metazoans, and are only the third such occurrence in Canada. In addition, specimens broadly resembling the problematic structure
Rugoinfractus ovruchensis
, previously known only from the Precambrian of the Ukraine, are reported from the Lower Cambrian of the nearby Mackenzie Mountains.
Satellite Detection of Effects Due to Increased Atmospheric Carbon Dioxide
Authors: Kiehl J. T.
Published: October 2006

The use of satellites to detect climatic changes due to increased carbon dioxide was investigated. This method has several advantages over ground-based methods of monitoring climatic change. Calculations indicate that, by monitoring the outgoing longwave flux for small intervals in the 15-micrometer spectral region, changes in stratospheric temperatures due to doubled atmospheric carbon dioxide are large enough to be detected above the various sources of noise. This method can be extended to other spectral regions so that causal links between changes in outgoing longwave radiation due to other trace gases and the thermal structure of the atmosphere could be established.
An Unusual Phycoerythrin from a Marine Cyanobacterium
Authors: Ong Linda J. , Glazer Alexander N. , Waterbury John B.
Published: October 2006

Phycoerythrin conjugates are reagents for cell sorting and analyses in which the argon-ion laser line at 488 nanometers is used for excitation. Many marine
Synechococcus
strains contain phycoerythrins with absorption maxima at approximately 490 and 550 nanometers; these maxima indicate the presence of phycourobilin and phycoerythrobilin prosthetic groups in the protein. Phycoerythrins of red algae contain both groups, but those of freshwater and soil cyanobacteria contain only phycoerythrobilin. Phycoerythrin purified from
Synechococcus
WH8103 has molecular properties typical of red algal phycoerythrins, but its phycourobilin content is higher than that of other phycoerythrins. The protein has absorption maxima at 492 and 543 nanometers and corresponding molar extinction coefficients of 2.78 and 1.14 × 10
6
; it fluoresces maximally at 565 nanometers with a quantum yield of 0.5. Conjugates of
Synechococcus
WH8103 phycoerythrin could increase the sensitivity of cell analysis techniques to almost twice that possible with other phycoerythrin conjugates.
Ozone- and Photon-Enhanced Atmospheric Sulfidation of Copper
Authors: Graedel T. E. , Franey J. P. , Kammlott G. W.
Published: October 2006

The sulfidation of materials upon exposure to the atmosphere has traditionally been attributed entirely to reactions with sulfur-containing gases and water vapor. New laboratory results demonstrate that the sulfidation of polycrystalline copper can be markedly enhanced both by solar radiation and by the ubiquitous atmospheric ozone, thus indicating that the high rates of corrosion in urban areas are a result of a complex sequence of multicomponent photochemical processes.
Inhibition of Plant Microtubule Polymerization in vitro by the Phosphoric Amide Herbicide Amiprophos-Methyl
Authors: Morejohn Louis C. , Fosket Donald E.
Published: October 2006

The phosphoric amide herbicide amiprophos-methyl (APM) produced a concentration-dependent inhibition of taxol-induced rose microtubule polymerization in vitro. Parallel studies on taxol-induced assembly of bovine brain microtubules showed no effect of APM at a concentration ten times that required to give complete inhibition of rose microtubule assembly. The data indicate that (i) APM is a specific and potent antimicrotubule drug and (ii) APM directly poisons microtubule dynamics in plant cells, rather than indirectly depolymerizing microtubules through a previously proposed mechanism involving deregulation of intracellular calcium levels.
Melting of Diamond
Authors: Gold Jon S. , Bassett William A. , Weathers Maura S. , Bird John M.
Published: October 2006

Radiation from a Q-switched YAG laser, focused on the (100) face of a single crystal diamond anvil in a high-pressure diamond cell, caused a portion of the diamond anvil face to melt. Potassium bromide mixed with graphite was under pressure between the anvils when melting occurred. The diamond surface melted at pressures greater than ∼120 kilobars and graphitized at lower pressures. Evidence for the melting and graphitization of the diamond was obtained by optical and scanning electron microscopy.
Rayleigh-Benard Convection in an Electrochemical Redox Cell
Authors: Ward William J. , Le Blanc Oliver H.
Published: October 2006

Damped voltage oscillations occur when current steps are applied to a cell consisting of a thin layer of Fe
111
/Fe
11
electrolyte sandwiched between horizontal, parallel, platinized platinum electrodes. The upper electrode must be the anode, and the magnitude of the current must be larger than a threshold value. The oscillations signal the onset of convection in the fluid. The experiment provides a new method for investigating transient convection processes.
Trends in Analytical Scale Separations
Authors: Jorgenson James W.
Published: October 2006

Although gas chromatography has been called a mature technology, advances are still being made in the development of faster columns as well as detectors which yield more information on solutes. In liquid chromatography short columns packed with 3-micrometer particles are already popular for fast analyses, while long narrow-bore columns are being developed for high-resolution separations. An increasing range of detection modes is enhancing the problem-solving capabilities of liquid chromatography. Electrophoresis continues to be of central importance to molecular biology. Computer-aided analysis and display of electropherogram patterns is helping researchers to better comprehend the wealth of data from two-dimensional electrophoresis. A new mode of two-dimensional electrophoresis is permitting separation of whole chromosomes containing as many as 3 million base pairs.
Holocene Sea Level Changes at the Coast of Dor, Southeast Mediterranean
Authors: Sneh Y. , Klein M.
Published: October 2006

Geological, geomorphological, and archeological data of changes in sea level during the Holocene at the Mediterranean coast of Dor provide a eustatic curve of the region. This curve shows that sea level was approximately 2 meters below the present level 4000 years ago, rose to 1 meter below the present level 3000 years ago, and was 1 meter higher than the present level 1500 years ago. It then dropped to 1 meter below the present level about 800 years ago.
Ecological Character Displacement in Darwin's Finches
Authors: Schluter Dolph , Price Trevor D. , Grant Peter R.
Published: October 2006

Character displacement resulting from interspecific competition has been extremely difficult to demonstrate. The problem was addressed with a study of Darwin's ground finches
(Geospiza).
Beak sizes of populations of
G. fortis
and
G. fuliginosa
in sympatry and allopatry were compared by a procedure that controls for any possible effects on morphology of variation among locations in food supply. The results provide strong evidence for character displacement. Measurement of natural selection in a population of
G. fortis
on an island (Daphne) lacking a resident population of
G. fuliginosa
shows how exploitation of
G. fuliginosa
foods affects the differential survival of
G. fortis
phenotypes
.
Uranium-Series Dating of Sediments from Searles Lake: Differences Between Continental and Marine Climate Records
Authors: Bischoff James L. , Rosenbauer Robert J. , Smith George I.
Published: October 2006

One of the major unresolved questions in Pleistocene paleoclimatology has been whether continental climatic transitions are consistent with the glacial δ
18
O marine record. Searles Lake in California, now a dry salt pan, is underlain by sediment layers deposited in a succession of lakes whose levels and salinities have fluctuated in response to changes in climate over the last 3 × 10
6
years. Uranium-series dates on the salt beds range from 35 × 10
3
to 231 × 10
3
years. This range of dates allows identification of lake-sediment horizons that are time correlatives of the boundaries of marine isotope stages from the recent 3/4 boundary back to the 8/9 boundary. The 5/6 boundary coincided with a deepening of the lake, but the analogous 1/2 boundary coincided with desiccation. The 3/4, 4/5, 6/7, 7/8, and 8/9 boundaries correspond in age to horizons that record little or no change in sedimentation or climate. These hydrologic results demonstrate that the continental paleoclimate record at this mid-latitude site does not mimic the marine record.
Xylem-Tapping Mistletoes: Water or Nutrient Parasites?
Authors: Ehleringer J. R. , Schulze E.-D. , Ziegler H. , Lange O. L. , Farquhar G. D. , Cowar I. R.
Published: October 2006

Most mistletoes parasitize higher plants by tapping the xylem (a conduction tissue) of their hosts. Field observations of diurnal gas exchange parameters and carbon isotope ratios in xylem-tapping mistletoes from three continents support the hypotheses that water use efficiency and carbon isotope composition are related and that mistletoes which are parasitic for water are also nutrient parasites, differing in their water use efficiency relative to that of their hosts on the basis of host nitrogen supply in the transpiration stream.
Tunable Coherent X-rays
Authors: Attwood David , Halbach Klaus , Kim Kwang-Je
Published: October 2006

A modern 1- to 2-billion-electron-volt synchrotron radiation facility (based on high-brightness electron beams and magnetic undulators) would generate coherent (laser-like) soft x-rays of wavelengths as short as 10 angstroms. The radiation would also be broadly tunable and subject to full polarization control. Radiation with these properties could be used for phase- and element-sensitive microprobing of biological assemblies and material interfaces as well as research on the production of electronic microstructures with features smaller than 1000 angstroms. These short wavelength capabilities, which extend to the K-absorption edges of carbon, nitrogen, and oxygen, are neither available nor projected for laboratory XUV lasers. Higher energy storage rings (5 to 6 billion electron volts) would generate significantly less coherent radiation and would be further compromised by additional x-ray thermal loading of optical components.
BK Virus DNA: Complete Nucleotide Sequence of a Human Tumor Virus
Authors: Yang Robert C. A. , Wu Ray
Published: October 2006

The complete DNA sequence of the human papovavirus BK is presented. From the 4963 base-pair sequence of BK virus (MM strain), the amino acid sequence of at least five proteins can be deduced: a T antigen and a t antigen, which share amino terminal peptides; proteins VP2 and VP3, which share 232 amino acids; and protein VP1, whose coding sequence overlaps those for VP2 and VP3 by 113 nucleotides but is read in a different frame. The gene loci and the arrangement of genes are strikingly similar in BK virus and simian virus 40 (SV40). The sequence of the deduced proteins in BK virus shares 73 percent amino acid homology with those in SV40, whereas the DNA sequence of the two viruses shares 70 percent homology, suggesting close evolutionary relationship. However, the repeated DNA sequences in the noncoding regions of these viruses are different.
Near-Earth Asteroids: Possible Sources from Reflectance Spectroscopy
Authors: McFadden Lucy A. , Gaffey Michael J. , McCord Thomas B.
Published: October 2006

Spectra of near-Earth asteroids were compared to spectra of selected asteroids, planets, and satellites to determine possible source regions. The diversity of reflectance spectra of the near-Earth asteroids implies different mineralogical compositions and hence more than one source region. The presence of near-Earth asteroid spectral signatures similar to those of certain main-belt asteroids supports models that derive some of these asteroids from the 5:2 Kirkwood gap and the Flora family by gravitational perturbations. Planetary and satellite surfaces are different in composition than the near-Earth asteroids, which is in agreement with theoretical arguments that such bodies should not be sources. Some near-Earth asteroids supply portions of Earth's meteorite flux, but other sources must also contribute.
Seismology of the Sun
Authors: Christensen-Dalsgaard Jørgen , Gough Douglas , Toomre Juri
Published: October 2006

Oscillations of the sun make it possible to probe the inside of a star. The frequencies of the oscillations have already provided measures of the sound speed and the rate of rotation throughout much of the solar interior. These quantities are important for understanding the dynamics of the magnetic cycle and have a bearing on testing general relativity by planetary precession. The oscillation frequencies yield a helium abundance that is consistent with cosmology, but they reinforce the severity of the neutrino problem. They should soon provide an important standard by which to calibrate the theory of stellar evolution.