bluuebunny/crossref_metadata_2025 huggingface dataset:
Fossil Grass Anthoecia Within Miocene Rhinoceros Skeletons: Diet in an Extinct Species
Authors: Voorhies Michael R. , Thomasson Joseph R.
Published: October 2006

Silicified anthoecia (fertile lemmas and paleas) of grasses (
Berriochloa communis
,
Berriochloa primaeva
, and
Berriochloa
cf.
nova
) were found in the oral cavity and rib cage in articulated skeletons of
Teleoceras major
buried in late Clarendonian volcanic ash in Nebraska. The plant fossils, thought to be food residues, help clarify the enigmatic paleobiological role of
Teleoceras
, which had hippopotamus-like proportions but very high-crowned teeth.
Teleoceras
was probably amphibious, but siliceous grasses formed a significant portion of its diet.
Laser-EXAFS: Fast Extended X-ray Absorption Fine Structure Spectroscopy with a Single Pulse of Laser-Produced X-rays
Authors: Mallozzi P. J. , Schwerzel R. E. , Epstein H. M. , Campbell B. E.
Published: October 2006

The extended x-ray absorption fine structure (EXAFS) spectrum of aluminum has been measured with a nanosecond pulse of soft x-rays generated by a laser-produced plasma. This technique provides a practical alternative to synchrotron radiation for the acquisition of EXAFS data. It also provides a unique capability for the analysis of molecular structure in highly transient chemical species.
Juvenile Hormone: Evidence of Its Role in the Reproduction of Ticks
Authors: Pound J. Mathews , Oliver James H.
Published: October 2006

Ovarian development, vitellogenesis, and embryogenesis in recently mated fed females of the soft tick
Ornithodoros parkeri
Cooley were prevented by topical application of the insect antiallatotropin precocene 2. The blockage was relieved by topical application of juvenile hormone. Cancellation of the anti-juvenile hormone effects of precocene 2 and the reestablishment of oogenesis (and oviposition in one specimen) by a naturally occurring insect juvenile hormone argues strongly for a physiological role of juvenile hormone in acarine reproduction.
Lectin-Induced Mucus Release in the Urn Cell Complex of the Marine Invertebrate
Sipunculus nudus
(Linnaeus)
Authors: Nicosia Santo V.
Published: October 2006

The mucociliary urn cell complex of the marine coelomate
Sipunculus nudus
secretes mucus 4 to 5 minutes after being exposed to
Lotus tetragonolobus
and
Ricinus communis
I agglutinins. Surface binding of both lectins is confined to the secretory area of the urn cell complex and, like the release of mucus, is inhibited by the specific saccharides L-fucose and D-galactose or by incubation in L-fucosidase and D-galactosidase. Mucus secretion may therefore be initiated by the interaction of mucus-releasing stimuli with fucosyl or galactosyl residues of specific membrane receptors.
Evidence of Acidification of Headwater Streams in the New Jersey Pinelands
Authors: Johnson Arthur H.
Published: October 2006

Seventeen years of stream
p
H data indicate a trend of acidification in two small streams in the New Jersey Pine Barrens which drain relatively undisturbed areas. The decline in
p
H has amounted to approximately 0.4 unit, with an estimated increase in H
+
concentration of about 50 microequivalents per liter. The data collected to date are consistent with the postulation of an atmospheric source for the increased H
+
.
Phanerozoic Land-Plant Diversity in North America
Authors: Knoll Andrew H. , Niklas Karl J. , Tiffney Bruce H.
Published: October 2006

A strong correlation exists between the outcrop area of nonmarine rocks deposited during a given geologic period and the observed vascular plant diversity for the same period; however, diversity residuals characteristic of certain periods may have underlying biological causes. Within-flora diversity changes through time indicate that stepwise increases in community species packing have accompanied major tracheophyte evolutionary innovations. Total and within-flora data suggest that the track of North American land-plant diversity has been similar in nature, but not in timing, to that inferred for marine invertebrates.
Reading a Neural Code
Authors: Bialek William , Rieke Fred , de Ruyter van Steveninck Rob R. , Warland David
Published: October 2006

Traditional approaches to neural coding characterize the encoding of known stimuli in average neural responses. Organisms face nearly the opposite task—extracting information about an unknown time-dependent stimulus from short segments of a spike train. Here the neural code was characterized from the point of view of the organism, culminating in algorithms for real-time stimulus estimation based on a single example of the spike train. These methods were applied to an identified movement-sensitive neuron in the fly visual system. Such decoding experiments determined the effective noise level and fault tolerance of neural computation, and the structure of the decoding algorithms suggested a simple model for real-time analog signal processing with spiking neurons.
Dislocations in Spinel and Garnet High-Pressure Polymorphs of Olivine and Pyroxene: Implications for Mantle Rheology
Authors: Madon Michel , Poirier Jean-Paul
Published: October 2006

The meteorite Tenham was observed by transmission electron microscopy and ringwoodite and majorite, the high-pressure polymorphs of olivine and pyroxene, were identified. Ringwoodite contains antiphase boundaries and straight dislocations that are probably dissociated. Mantle flow of spinel might proceed by pure climb, and whole-mantle convection may be possible if the grain size is small enough.
Saturn's Magnetic Field and Magnetosphere
Authors: Smith E. J. , Davis L. , Jones D. E. , Coleman P. J. , Colburn D. S. , Dyal P. , Sonett C. P.
Published: October 2006

The Pioneer Saturn vector helium magnetometer has detected a bow shock and magnetopause at Saturn and has provided an accurate characterization of the planetary field. The equatorial surface field is 0.20 gauss, a factor of 3 to 5 times smaller than anticipated on the basis of attempted scalings from Earth and Jupiter. The tilt angle between the magnetic dipole axis and Saturn's rotation axis is < 1°, a surprisingly small value. Spherical harmonic analysis of the measurements shows that the ratio of quadrupole to dipole moments is < 10 percent, indicating that the field is more uniform than those of the Earth or Jupiter and consistent with Saturn having a relatively small core. The field in the outer magnetosphere shows systematic departures from the dipole field, principally a compression of the field near noon and an equatorial orientation associated with a current sheet near dawn. A hydromagnetic wake resulting from the interaction of Titan with the rotating magnetosphere appears to have been observed.
Impact of Saturn Ring Particles on Pioneer 11
Authors: Humes D. H. , O'Neal R. L. , Kinard W. H. , Alvarez J. M.
Published: October 2006

The particle flux measured by the meteoroid detectors on Pioneer 11 increased greatly while the spacecraft was near the rings of Saturn. The data suggest that the particles were associated with the rings and were not interplanetary meteoroids concentrated near the planet by gravitational focusing. The data also suggest that the E ring may be 1800 kilometers thick with an optical thickness greater than 10
–8
.
Cellulose in the Cell Walls of the Bangiophyceae (Rhodophyta)
Authors: Gretz Michael R. , Aronson Jerome M. , Sommerfeld Milton R.
Published: October 2006

Mechanically isolated cell walls of the conchocelis phase of
Bangia fuscopurpurea
yield cellulose II (regenerated cellulose) upon treatment with Schweitzer's reagent. X-ray powder analysis and thin-layer chromatography of partial hydrolyzates confirm the presence of cellulose in this extract. Gas-liquid chromatographic analysis of wall hydrolyzates indicates that xylose, mannose, galactose, and glucose are major wall constituents. The presence of cellulose in the conchocelis provides evidence that this bangiophycean life cycle phase represents a transitional form or link between the two classes of red algae, Bangiophyceae and Florideophyceae. This suggests a close affinity of the two classes of the Rhodophyta and supports the hypothesis that bangiophycean algae were precursors of the Florideophyceae.
Genetic Differences in Physiological Tolerances of Amargosa Pupfish (
Cyprinodon nevadensis
) Populations
Authors: Hirshfield Michael F. , Feldmeth C. Robert , Soltz David L.
Published: October 2006

Amargosa pupfish from a constant-temperature spring have a narrower range of temperature and oxygen tolerances than pupfish from the much more variable Amargosa River, indicating that the two populations have diverged genetically since their isolation. The reduced tolerances of the fish inhabiting a constant environment support the predictions of evolution theory.
Core Drilling Through the Ross Ice Shelf (Antarctica) Confirmed Basal Freezing
Authors: Zotikov Igor A. , Zagorodnov Victor S. , Raikovsky Juriy V.
Published: October 2006

New techniques that have been used to obtain a continuous ice core through the whole 416-meter thickness of the Ross Ice Shelf at Camp J-9 have demonstrated that the bottom 6 meters of the ice shelf consists of sea ice. The rate of basal freezing that is forming this ice is estimated by different methods to be 2 centimeters of ice per year. The sea ice is composed of large vertical crystals, which form the waffle-like lower boundary of the shelf. A distinct alignment of the crystals throughout the sea ice layer suggests the presence of persistent long-term currents beneath the ice shelf.
Clarkforkian Land-Mammal Age: Revised Definition, Zonation, and Tentative Intercontinental Correlations
Authors: Rose Kenneth D.
Published: October 2006

New faunal and stratigraphic evidence documents the validity of the North American Clarkforkian Land-Mammal Age. Its limits are defined by the initial appearances of immigrant taxa. In the type area (northwestern Wyoming), the Clarkforkian is subdivided into three zones. Clarkforkian faunas are approximately correlative with latest Paleocene-earliest Eocene faunas of the Paris Basin of Europe and in part with the Gashato-Naran Bulak faunas of Mongolia.
Heterogeneous Catalysts
Authors: Sleight Arthur W.
Published: October 2006

Proven catalysts exist in many different forms and with many different kinds of composition. An understanding of how catalysts function is beginning to emerge in a few areas, and some superior catalysts have been developed as a result of this knowledge. Applications of new techniques and disciplines should lead to impressive advances in the years ahead.
New Methods of Processing Silicon Slices
Authors: Penn Thomas Clifton
Published: October 2006

Through the use of room-temperature, radio-frequency plasma ionization of gases, the insulating, conducting, and semiconducting materials associated with the fabrication of silicon integrated circuits can be patterned to submicrometer dimensions. A tutorial description is presented of the fabrication techniques used in the past with an overview of where plasma processing has made noteworthy improvements in the lithography of materials.
Technology Assessment, Soviet Style
Authors: Gustafson Thane
Published: October 2006

The Soviet Union is actively considering two plans to divert large northern lakes and rivers to the south of the country. If adopted, these would rank among the most expensive and complicated engineering projects ever undertaken, with unforeseeable but possibly far-reaching environmental effects. The plans, now at an advanced stage, have aroused a spirited public controversy, providing an unusual glimpse of Soviet policy-making and technology assessment. Major decisions are due by 1985. The question is, what will happen to the quality and openness of this debate as the political stakes rise and the time of decision draws near?
Stratospheric Sulfuric Acid Layer: Evidence for an Anthropogenic Component
Authors: Hofmann D. J. , Rosen J. M.
Published: October 2006

Recent measurements of small aerosol particles in the stratosphere over Laramie, Wyoming, indicate low-concentration background conditions. A comparison of measurements made some 20 years ago with the present background concentration reveals the possibility of an increase of 9 percent per year. Since the aerosol particles are predominantly sulfuric acid droplets which form in the stratosphere from tropospheric sulfur-containing gases, such an increase may be related to man-made sulfur emissions.
Spaceborne Imaging Radar: Monitoring of Ocean Waves
Authors: Beal Robert C.
Published: October 2006

A well-organized, very low energy ocean swell system off the East Coast of the United States was tracked with the Seasat synthetic aperture radar from deep water, across the continental shelf, and into shallow water. The results indicate that spaceborne imaging radar may be used to accurately measure ocean wavelength and direction, even in coastal areas and in the presence of a mixed ocean.
Pressure-Adaptive Differences in Lactate Dehydrogenases of Congeneric Fishes Living at Different Depths
Authors: Siebenaller Joseph , Somero George N.
Published: October 2006

The muscle-type (M
4
) lactate dehydrogenases of
Sebastolobus altivelis
, a deep-water scorpaenid, and
S. alascanus
, a shallower species, are electrophoretically indistinguishable, yet differ in pressure sensitivities. The lactate dehydrogenase of
S. altivelis
exhibits lower pressure sensitivities of substrate and coenzyme binding and catalytic rate. Such apparently pressure-adaptive kinetic properties may be important for establishing species depth zonation patterns in the ocean.
Chemical Evolution from Hydrogen Cyanide: Photochemical Decarboxylation of Orotic Acid and Orotate Derivatives
Authors: Ferris J. P. , Joshi P. C.
Published: October 2006

Irradiation of solutions at
p
H 7 to
p
H 8.5 of orotic acid, orotidine, and orotidine 5′-phosphate with light at 254 nanometers yields the corresponding uracil derivative via the singlet excited state. This reaction completes a plausible prebiotic synthesis of uracil and its derivatives starting from HCN as the only carbon source.
Energy Dilemmas in Asia: The Needs for Research and Development
Authors: Revelle Roger
Published: October 2006

Outside of China, the countries of southern and eastern Asia contain 30 percent of the world's population but only 2 percent of the known fossil fuel resources. Economic growth has resulted in increasing imports of petroleum and petroleum products. Because of the tenfold rise in oil prices since 1972, several of these countries are faced with two dilemmas—one short range and one long range. Unless they can discover more fossil fuel resources within their own borders, they must either incur dangerously growing foreign exchange deficits or drastically slow their economic growth. Research and development in energy production, conversion, and conservation should eventually allow local energy sources, of which the most promising is biomass energy, to be substituted for imported fuels. But diverting scarce land and water to plantations of fast-growing trees or other kinds of biomass may seriously limit food production in these crowded countries.
Ion Pairing Techniques: Compatibility with On-Line Liquid Chromatography—Mass Spectrometry
Authors: Kirby D. P. , Vouros Paul , Karger B. L.
Published: October 2006

The mass spectrometric properties of a series of model ion pairs were examined. In the cases studied it was possible to vaporize the ion pair constituents and to produce spectra corresponding to those of the unpaired materials. These findings offer a convenient means for derivatizing certain ionic compounds and demonstrate the feasibility of analyzing ionic species by on-line liquid chromatography-mass spectrometry.
Arctic Oceanic Climate in Late Cenozoic Time
Authors: Herman Yvonne , Hopkins David M.
Published: October 2006

Faunal and lithologic evidence is used to reconstruct paleoceanographic events over the last 4.5 million years. The inception of perennial sea-ice cover is dated at about 0.7 million years.
Equatorial Currents in the Western Indian Ocean
Authors: Luyten J. R. , Fieux M. , Gonella J.
Published: October 2006

Measurements were made in the equatorial Indian Ocean during spring and summer 1979 from the Somali coast to 62°E in the interior of the western basin. The detailed vertical profiles of horizontal current show that the energetic dominance throughout the region of variability was on vertical scales of several hundreds of meters, confined to within a few degrees of the equator, as observed in 1976. The near-surface equatorial circulation responded directly to variations in the wind field, and satellite-tracked drifter buoys showed the equatorial surface jet extending across the width of the ocean. This eastward flow is generated by the eastward winds that appear in the interval between the northeast and southwest monsoons. The zonal velocity fluctuations extended in a consistent pattern over the observation region. The time and meridional scales of the variability were similar to those observed in 1976, suggesting that the velocity field is dominated by long-term, equatorially trapped motions with long zonal scales.
Focus on Polar Research
Authors: Washburn A. L.
Published: October 2006

A few of the scientific challenges of polar research are reviewed, with stress on the work being done by U.S. investigators. The accomplishments that have been made are impressive, but much remains to be done. An evaluation of future research goals and priorities in science per se and in the national interest is not attempted, but a research strategy for the future, presently planned by the National Research Council's Polar Research Board, should contribute to this end.
Stable Isotopes in Benthic Foraminifera: Seasonal Variation in Large Tropical Species
Authors: Wefer G. , Berger W. H.
Published: October 2006

The shells of large benthic foraminifera contain a record of seasonal temperature ranges and life history stages.
Marginopora vertebralis
and
Cyclorbiculina compressa
show distinct differences in life history, growth rate history, and life-span, as reflected in stable isotope patterns within their shells.
Geographic Variation and Episodic Evolution in an Ordovician Trilobite
Authors: Cisne John L. , Chandlee George O. , Rabe Bruce D. , Cohen Jill A.
Published: October 2006

A single lineage of the trilobite
Flexicalymene
shows two evolutionary "punctuated equilibria" within a 2-million-year, 1000-square-kilometer stratigraphic interval. The 2 × 10
5
-year-long "punctuation" may represent parapatric speciation. Commonness of depth-related clines before, during and after this event suggests that short-term adjustment to local conditions was important in long-term evolution.
The Archeology of Alaska and the Peopling of America
Authors: Dumond Don E.
Published: October 2006

The proposed existence of a biotically productive tundra-steppe on the exposed Bering Land Bridge of the late Pleistocene aids conceptualization of the migrations of early Asian hunters. But clear knowledge of the human occupants of northwesternmost America before 11,000 years ago is elusive. Evidence indicates that at that time the Alaskan peoples had a culture generally based on microliths that, while obviously derived from Asia, were not sufficiently similar to the tools of the earliest widely distributed hunters of more southerly North America to support any direct and close relation between the two cultures.
High-Frequency Skywave Radar Measurements of Hurricane Anita
Authors: Maresca Joseph W. , Carlson Christopher T.
Published: October 2006

We tracked and monitored hurricane Anita over a 5-day period by using the SRI-operated Wide Aperture Research Facility (WARF) high-frequency skywave radar. The WARF-derived positions for Anita agreed to within ± 19 kilometers of the coincident temporal positions along the National Hurricane Center's smooth track. Hurricane Anita passed near the open ocean-moored buoy EB-71 of the National Oceanic and Atmospheric Administration, and measurements of wind direction, wind speed, and significant wave height made during this period at the WARF and in situ at the buoy showed agreement of 7°, 0.4 meter per second, and 0.5 meter, respectively. The WARF estimates of longshore coastal surface currents showed good agreement with measurements made at a moored current meter.
Ganymede: A Relationship Between Thermal History and Crater Statistics
Authors: Phillips Roger J. , Malin Michael C.
Published: October 2006

An approach for factoring the effects of a planetary thermal history into a predicted set of crater statistics for an icy satellite is developed and forms the basis for subsequent data inversion studies. The key parameter is a thermal evolution-dependent critical time for which craters of a particular size forming earlier do not contribute to present-day statistics. An example is given for the satellite Ganymede and the effect of the thermal history is easily seen in the resulting predicted crater statistics. A preliminary comparison with the data, subject to the uncertainties in ice rheology and impact flux history, suggests a surface age of 3.8 × 10
9
years and a radionuclide abundance of 0.3 times the chondritic value.
Eastern Geothermal Resources: Should We Pursue Them?
Authors: Tillman J. E.
Published: October 2006

A geothermal resource that consists of hot water at moderate temperatures (below 125°C) underlies many areas in the central and eastern United States. Programs funded by the Department of Energy have revealed that this resource is definable and economically competitive with conventional fuels for use in direct heat applications. The resource, therefore, has the potential for reducing our dependence on the imported oil used for space heating. However, front-end costs and risks to explore, drill, test, and evaluate the magnitude of the resource have inhibited development. The question is, therefore, how much federal stimulation will be needed to convince private capital to exploit this widespread low-quality energy source.
Adaptive Topography in Family-Structured Models of Kin Selection
Authors: Michod Richard E. , Abugov Robert
Published: October 2006

Adaptive topographies provide a means of summarizing the qualitative dynamics of evolution. Inclusive fitness serves as an organizing concept in much of sociobiology. Through the use of Sewall Wright's "fitness function," the theoretical equivalence of these concepts for weak selection in family-structured populations is demonstrated.
Io: Ground-Based Observations of Hot Spots
Authors: Sinton W. M. , Tokunaga A. T. , Becklin E. E. , Gatley I. , Lee T. J. , Lonsdale C. J.
Published: October 2006

Observations of Io in eclipse demonstrate conclusively that Io emits substantial amounts of radiation at 4.8 and 3.8 micrometers and a measurable amount at 2.2 micrometers. Color temperatures derived from the observations fit blackbody emission at 560 K. The required source area to yield the observed 4.8-micrometer flux is approximately 5 × 10
–5
of the disk of Io and is most likely comprised of small hot spots in the vicinity of the volcanoes.
Lightning on Jupiter: Rate, Energetics, and Effects
Authors: Lewis John S.
Published: October 2006

Voyager data on the optical and radio-frequency detection of lightning discharges in the atmosphere of Jupiter suggest a stroke rate significantly lower than on the earth. The efficiency of conversion of atmospheric convective energy flux into lightning is almost certainly less than on the earth, probably near 10
–7
rather than the terrestrial value of 10
–4
. At this level the rate of production of complex organic molecules by lightning and by thunder shock waves is negligible compared to the rates of known photochemical processes for forming colored inorganic solids.
Evidence for a Novel Thioredoxin-Like Catalytic Property of Gonadotropic Hormones
Authors: Boniface J .Jay , Reichert Leo E.
Published: October 2006

It has been proposed that dithiol-disulfide interchange and oxidation-reduction reactions may play a role in hormone-induced receptor activation. Inspection of the sequences of the gonadotropic hormones revealed a homologous tetrapeptide (Cys-Gly-Pro-Cys) between the β subunit of lutropin (LH) and the active site of thioredoxin (TD). The β subunit of follitropin (FSH) has a similar sequence (Cys-Gly-Lys-Cys). Thioredoxin is a ubiquitous protein serving as an electron donor for ribonucleotide reductase, but it also exhibits disulfide isomerase activity. The catalytic activity of TD was assayed by its ability to reactivate reduced and denatured ribonuclease. In this assay, the purified ovine FSH and bovine LH preparations tested were ∼60 and ∼300 times, respectively, as active as TD on a molar basis. This heretofore unsuspected catalytic property of FSH and LH may be important in understanding their mechanism of receptor activation and signal transduction.
Two Distinct Transcription Factors that Bind the Immunoglobulin Enhancer μE5/κE2 Motif
Authors: Henthorn Paula , Kiledjian Megerditch , Kadesch Tom
Published: October 2006

Activity of the immunoglobulin heavy and κ light chain gene enhancers depends on a complex interplay of ubiquitous and developmentally regulated proteins. Two complementary DNAs were isolated that encode proteins, denoted ITF-1 and ITF-2, that are expressed in a variety of cell types and bind the μE5/κE2 motif found in both heavy and κ light chain enhancers. The complementary DNAs are the products of distinct genes, yet both ITF-1 and ITF-2 are structurally and functionally similar. The two proteins interact with one another through their putative helix-loop-helix motifs and each possesses a distinct domain that dictates transcription activation.
Hypoxic Dilation of Coronary Arteries Is Mediated by ATP-Sensitive Potassium Channels
Authors: Daut Jürgen , Maier-Rudolph Willibald , von Beckerath Nikolas , Mehrke Gerhard , Günther Kerstin , Goedel-Meinen Liselotte
Published: October 2006

The function of the heart depends critically on an adequate oxygen supply through the coronary arteries. Coronary arteries dilate when the intravascular oxygen tension decreases. Hypoxic vasodilation in isolated, perfused guinea pig hearts can be prevented by glibenclamide, a blocker of adenosine triphosphate (ATP)-sensitive potassium channels, and can be mimicked by cromakalim, which opens ATP-sensitive potassium channels. Opening of potassium channels in coronary smooth muscle cells and the subsequent drop in intracellular calcium is probably the major cause of hypoxic and ischemic vasodilation in the mammalian heart.
The Hawaii to Tahiti Shuttle Experiment
Authors: Wyrtki Klaus , Firing Eric , Halpern David , Knox Robert , McNally G. J. , Patzert W. C. , Stroup E. D. , Taft B. A. , Williams R.
Published: October 2006

The Shuttle Experiment conducted between Hawaii and Tahiti from January 1979 to June 1980 was designed to observe the changing equatorial ocean structure and circulation, to study the variations and interactions of the four major equatorial ocean currents, and to develop a scientific basis for their monitoring by simple observations of thermal structure and sea level. Preliminary analyses of the results show that the equatorial thermal structure remains intact during a normal year and that only the positions and intensities of the currents are subject to change. The water transport of the equatorial undercurrent varied from 25 × 10
6
cubic meters per second in January to 51 × 10
6
cubic meters per second in July, but also exhibited strong short-term pulsations. The equatorial surface flow responded strongly to the winds at periods of 1 month and longer. An array of drifter buoys in the equatorial countercurrent was subject to very little dispersion while traveling over 4500 kilometers in 4 months. Low-frequency fluctuations in the North Equatorial Countercurrent can be monitored by means of the difference in sea level between Fanning and Majuro.
Science and Technology in the White House, 1977 to 1980: Part 2
Authors: Press Frank
Published: October 2006

This is the second half of a two-part article on Administration science and technology policy during the period 1977 to 1980. The first part discussed the role of the Office of Science and Technology Policy (OSTP) in the context of the overall federal policy-making framework and institutional structure and described specific activities aimed at strengthening U.S. science and technology, fostering industrial innovation, enhancing relationships among government, universities, and industry, and improving the regulatory process. This part focuses on OSTP activities related to national security and foreign policy, space, energy and the environment, health, and agriculture, and discusses OSTP advisory mechanisms and planning efforts.
Using Materials Science
Authors: Baker W. O.
Published: October 2006

The science of the solid state has joined nuclear science and molecular biology as a field of major importance in the latter half of the 20th century. It took particular shape during the genesis of solid-state electronics and the post-transistor era of integrated circuits for telecommunications, computers, and digital signal machines. However, these developments were soon joined by techniques from the ancient fields of metallurgy and ceramics and contributions from the more current fields of synthetic polymers, rubbers, plastics, and modified bioorganic substances. This vast realm was characterized by a National Academy of Sciences study of the 1970's as "materials science and engineering." The public, as well as the scientific and engineering community, are currently concerned about the uses of research and development and the applications of knowledge for national progress. Consideration is given here to how well we are using the science of materials for industrial strength and such governmental objectives as national security and energy economy.
Solar Cycle Signal in Earth Rotation: Nonstationary Behavior
Authors: Currie Robert G.
Published: October 2006

Following the discovery of the 11-year solar cycle signal in earth rotation, linear techniques were employed to investigate the amplitude and phase of the difference between ephemeris time and universal time (Δ
T
) as a function of time. The amplitude is nonstationary. This difference was related to Δ(LOD), the difference between the length of day and its nominal value. The 11-year term in Δ(LOD) was 0.8 millisecond at the close of the 18th century and decreased below noise level from 1840 to 1860. From 1875 to 1925, Δ(LOD) was about 0.16 millisecond, and it decreased to about 0.08 millisecond by the 1950's. Except for anomalous behavior from 1797 to 1838, Δ
T
lags sunspot numbers by 3.0 ± 0.4 years. Since Δ
T
lags Δ(LOD) by 2.7 years, the result is that Δ(LOD) is approximately in phase with sunspot numbers.
Structural Motif of the GCN4 DNA Binding Domain Characterized by Affinity Cleaving
Authors: Oakley Martha G. , Dervan Peter B.
Published: October 2006

The NH2-terminal locations of a dimer containing the DNA binding domain of the yeast transcriptional activator GCN4 have been mapped on the binding sites 5′-CTGACTAAT-3′ and 5′-ATGACTCTT-3′. Affinity cleaving was effected by synthetic GCN4 proteins with Fe⋅EDTA moieties at the NH
2
-terminus. Analysis of the DNA cleavage patterns for dimers of the Fe⋅EDTA-proteins corresponding to GCN4 residues 222 to 281 and 226 to 281 revealed that the NH
2
-termini were in the major groove nine to ten base pairs apart and were symmetrically displaced four to five base pairs from the central C of the recognition site. This result is consistent with the Y-shaped scissor grip-leucine zipper model recently proposed for a class of DNA binding proteins important in the regulation of gene expression.
The Role of B Cells for in Vivo T Cell Responses to a Friend Virus-Induced Leukemia
Authors: Schultz Kirk R. , Klarnet Jay P. , Gieni Randall S. , HayGlass Kent T. , Greenberg Philip D.
Published: October 2006

B cells can function as antigen-presenting cells and accessory cells for T cell responses. This study evaluated the role of B cells in the induction of protective T cell immunity to a Friend murine leukemia virus (F-MuLV)-induced leukemia (FBL). B cell-deficient mice exhibited significantly reduced tumor-specific CD4
+
helper and CD8
+
cytotoxic T cell responses after priming with FBL or a recombinant vaccinia virus containing F-MuLV antigens. Moreover, these mice had diminished T cell responses to the vaccinia viral antigens. Tumor-primed T cells transferred into B cell-deficient mice effectively eradicated disseminated FBL. Thus, B cells appear necessary for efficient priming but not expression of tumor and viral T cell immunity.
Voyager 1 Encounter with the Saturnian System
Authors: Stone E. C. , Miner E. D.
Published: October 2006

An overview of the Voyager 1 encounter with Saturn is presented, including a brief discussion of the flight, trajectory, science plan formulation, and highlights of the results described in the subsequent reports.
Hinged Teeth in Snakes: An Adaptation for Swallowing Hard-Bodied Prey
Authors: Savitzky Alan H.
Published: October 2006

Six genera of snakes, representing at least three lineages, possess teeth that fold backward against the jaws rather than being firmly ankylosed. This condition, effected by a connective tissue hinge at the base of each tooth, is associated with suites of cephalic modifications that enable the snakes to grasp and to swallow hard-bodied prey.
Oceanic Mechanisms for Amplification of the 23,000-Year Ice-Volume Cycle
Authors: Ruddiman William F. , McIntyre Andrew
Published: October 2006

Situated adjacent to the largest Northern Hemisphere ice sheets of the ice ages, the mid-latitude North Atlantic Ocean has an important role in the earth's climate history. It provides a significant local source of moisture for the atmosphere and adjacent continents, forms a corridor that guides moisture-bearing storms northward from low latitudes, and at times makes direct contact along its shorelines with continental ice masses. Evidence of major ice-ocean-air interactions involving the North Atlantic during the last 250,000 years is summarized. Outflow of icebergs and meltwater initially driven by summer insolation over the ice sheets affects mid-latitude ocean temperatures, summer heat storage, winter sea-ice extent, and global sea level. These oceanic responses in turn influence the winter moisture flux back to the ice sheets, as well as ablation of land ice by calving. Spectral data indicate that the oceanic moisture and sea-level feedbacks, in part controlled by glacial melt products, amplify Milankovitch (insolation) forcing of the volumetrically dominant mid-latitude ice sheets at the 23,000-year precessional cycle.
All-Female Fish: A Cryptic Species of
Menidia
(Atherinidae)
Authors: Echelle Anthony A. , Mosier Doyle T.
Published: October 2006

Electrophoretic evidence revealed the common occurrence of an all-female species of
Menidia
(Pisces: Atherinidae) at two localities separated by 280 kilometers on the Gulf Coast of Texas. This finding adds significantly to the known taxonomic spectrum of unisexuality in fishes and demonstrates that unisexuality may be more common among fishes that do not bear live young than is generally suspected.
The Role of β
2
-Microglobulin in Peptide Binding by Class I Molecules
Authors: Vitiello Antonella , Potter Terry A. , Sherman Linda A.
Published: October 2006

Efficient transport of class I major histocompatibility complex molecules to the cell surface requires association of the class I heavy chain with endogenous peptide and the class I light chain, β
2
-microglobulin (β
2
M). A mutant cell line deficient in β
2
M transports low amounts of nonpeptide-associated heavy chains to the cell surface that can associate with exogenously provided β
2
M and synthetic peptide antigens. Normal β
2
M-sufficient cells grown in serum-free media devoid of β
2
M also require an exogenous source of β
2
M to efficiently bind synthetic peptide. Thus, class I molecules on normal cells do not spontaneously bind or exchange peptides.
The Agriculture Grants Program
Authors: Krogmann David W. , Key Joe
Published: October 2006

The Competitive Research Grants Office was established in 1978 by the federal government to encourage and support basic research related to agriculture. The effort has been enfeebled by controversy and continues to teeter on the edge of congressional extinction. The origins of the Competitive Research Grants Office and its first 3 years of operation make an interesting portrait of the problems of science and government in these times.
Blood Function in the Hydrothermal Vent Vestimentiferan Tube Worm
Authors: Arp Alissa J. , Childress James J.
Published: October 2006

Extracellular hemoglobin in the whole blood of
Riftia pachyptila
has a high oxygen affinity (
P
50
= 1.8 millimeters of mercury at 3°C), a moderate decrease in oxygen affinity at higher temperatures (
P
50
= 2.7 millimeters of mercury at 14°C), a small effect of carbon dioxide on oxygen affinity (Δ log
P
50
/ Δ
p
H =–0.12), and a high oxygen carrying capacity (up to 11 milliliters of oxygen per 100 milliliters of blood). These characteristics are compatible with the high oxygen demand of chemoautotrophic metabolism in the variable vent environment.
Primitive Hominid Canine from Tanzania
Authors: White Tim D.
Published: October 2006

A primitive hominid canine recovered at Laetoli by Louis Leakey in 1935 and stored at the British Museum of Natural History adds to our knowledge of dental anatomy in
Australopithecus
. The specimen was the first adult
Australopithecus
recovered and the first ancient hominid discovered in eastern Africa.
Biomass as a Source of Chemical Feedstocks: An Economic Evaluation
Authors: Palsson B. O. , Fathi-Afshar S. , Rudd D. F. , Lightfoot E. N.
Published: October 2006

It is suggested that the raw materials and technology exist for basing a major fraction of the U.S. chemical industry on four fermentation products, used in the proper portions: ethanol, isopropanol,
n
-butanol, and 2,3-butanediol. The primary route for introduction of these materials is dehydration of the alcohols and diols to olefins, which would cause little disruption of the existing industry downstream from the olefins. The proposed substitution has the advantages that it would provide a smooth transition toward renewable feedstocks, while decreasing dependence on fossil sources of organic material and use of toxic materials. However, to make these materials attractive as feedstocks or intermediates in chemical production, their current prices must be substantially reduced. Even with the optimum mix, their large-scale utilization will only occur at about 20 to 40 percent of their estimated chemical prices.
Transformations of Nitrogen in a Polluted Estuary: Nonlinearities in the Demand for Oxygen at Low Flow
Authors: Wofsy S. C. , McElroy M. B. , Elkins J. W.
Published: October 2006

Oxidation of sewage ammonium in the Potomac River is described in terms of a simple kinetic model, with growth of nitrifying bacteria limited by the supply of ammonium ion. The oxidation rate varies inversely with freshwater inflow, and the associated demand for oxygen varies as the inverse square of the freshwater inflow rate. Similar behavior is observed for the Delaware River. The model accounts for the observed concentrations of ammonium and nitrous oxide.
Type 1 Neurofibromatosis Gene: Identification of a Large Transcript Disrupted in Three NF1 Patients
Authors: Wallace Margaret R. , Marchuk Douglas A. , Andersen Lone B , Letcher Roxanne , Odeh Hana M. , Saulino Ann M. , Fountain Jane W. , Brereton Anne , Nicholson Jane , Mitchell Anna L. , Brownstein Bernard H. , Collins Francis S.
Published: October 2006

Von Recklinghausen neurofibromatosis (NF1) is a common autosomal dominant disorder characterized by abnormalities in multiple tissues derived from the neural crest. No reliable cellular phenotypic marker has been identified, which has hampered direct efforts to identify the gene. The chromosome location of the
NF1
gene has been previously mapped genetically to 17q11.2, and data from two NF1 patients with balanced translocations in this region have further narrowed the candidate interval. The use of chromosome jumping and yeast artificial chromosome technology has now led to the identification of a large (∼13 kilobases) ubiquitously expressed transcript (denoted
NF1LT
) from this region that is definitely interrupted by one and most likely by both translocations. Previously identified candidate genes, which failed to show abnormalities in NF1 patients, are apparently located within introns of
NF1LT
, on the antisense strand. A new mutation patient with NF1 has been identified with a de novo 0.5-kilobase insertion in the
NF1LT
gene. These observations, together with the high spontaneous mutation rate of NF1 (which is consistent with a large locus), suggest that
NF1LT
represents the elusive
NF1
gene.
Dated Rock Engravings from Wonderwerk Cave, South Africa
Authors: Thackeray Anne I. , Thackeray J. Francis , Beaumont Peter B. , Vogel J. C.
Published: October 2006

Radiocarbon dates associated with engraved stones from sealed archeological deposits at Wonderwerk Cave in the northern Cape Province indicate that rock engraving in South Africa is at least 10,000 years old.
Lower Eocene and Paleocene Gentianaceae: Floral and Palynological Evidence
Authors: Crepet William L. , Daghlian Charles P.
Published: October 2006

Lower Eocene flowers with
Pistillipollenites macgregorii
pollen represent the earliest megafossil evidence of the Gentianaceae. The Paleocene occurrence of
P. macgregorii
, the fossil's modern floral structure, and suggested trends in the evolution of pollen in the Gentianaceae indicate a considerably earlier origin for the family. Floral morphology typical of bee-pollinated flowers provides the earliest, albeit indirect, fossil evidence of bees.
Wind Generation of the Costa Rica Dome
Authors: Hofmann Eileen E. , Busalacchi Antonio J. , O'Brien James J.
Published: October 2006

Upwelling in the Costa Rica Dome is seasonal and the result of the localized cyclonic wind stress curl. Fluctuations in the wind stress curl in the fall release the upwelled region as a Rossby wave. Similar low-latitude domes are hypothesized to be ubiquitous to those oceans where a localized cyclonic wind stress curl is associated with an Intertropical Convergence Zone.
Space Shuttle: A New Era in Terrestrial Remote Sensing
Authors: Taranik James V. , Settle Mark
Published: October 2006

The space shuttle will carry its first scientific cargo into orbit on its second test flight. The seven experiments to be conducted during this flight—investigations related to continental geology, atmospheric chemistry, meteorology, marine biology, and plant physiology—will demonstrate the potential usefulness of the shuttle for research in the earth and life sciences.
Growth Rate of a Vesicomyid Clam from the Galápagos Spreading Center
Authors: Turekian Karl K. , Cochran J. Kirk
Published: October 2006

The shell of a 19-centimeter-long vesicomyid clam, collected live at the Galápagos spreading center hydrothermal field, was sampled along growth lines and analyzed for members of the
238
U and
232
Th decay series. The growth rate, determined from the
210
Po/
210
Pb and
228
Th/
228
Ra couples, is about 4 centimeters per year along the axis of maximum growth, which is 12 centimeters long. This yields an age of 3 to 4 years for this clam.
Predation Through Geological Time: Evidence from Gastropod Shell Repair
Authors: Vermeij Geerat J. , Schindel David E. , Zipser Edith
Published: October 2006

Warm-water marine gastropods from soft-bottom habitats show an increase in the incidence of breakage-resistant shell characteristics over geological time. The hypothesis that breakage became a more important component of selection in the middle of the Mesozoic Era is supported by the finding that frequencies of breakage-induced shell repair increased from the Pennsylvanian and Triassic periods to the Cretaceous, Miocene, and Recent.
Pheromone Orientation: Role of Internal Control Mechanisms
Authors: Tobin Thomas R.
Published: October 2006

Male American cockroaches walk a zigzag path upwind toward a source of female sex pheromone. Although the maximum width of the pathway is regulated by the width of an odor plume, many turns are made before the edge of a wide plume is encountered. In addition to the pheromone regulation of the insect's orientation movements, an internal mechanism appears to influence the zigzag turning pattern.
D
1
and D
2
Dopamine Receptor-regulated Gene Expression of Striatonigral and Striatopallidal Neurons
Authors: Gerfen Charles R. , Engber Thomas M. , Mahan Lawrence C. , Susel Zvi , Chase Thomas N. , Monsma Frederick J. , Sibley David R.
Published: October 2006

The striatum, which is the major component of the basal ganglia in the brain, is regulated in part by dopaminergic input from the substantia nigra. Severe movement disorders result from the loss of striatal dopamine in patients with Parkinson's disease. Rats with lesions of the nigrostriatal dopamine pathway caused by 6-hydroxydopamine (6-OHDA) serve as a model for Parkinson's disease and show alterations in gene expression in the two major output systems of the striatum to the globus pallidus and substantia nigra. Striatopallidal neurons show a 6-OHDA-induced elevation in their specific expression of messenger RNAs (mRNAs) encoding the D
2
dopamine receptor and enkephalin, which is reversed by subsequent continuous treatment with the D
2
agonist quinpirole. Conversely, striatonigral neurons show a 6-OHDA-induced reduction in their specific expression of mRNAs encoding the D
1
dopamine receptor and substance P, which is reversed by subsequent daily injections of the D
1
agonist SKF-38393. This treatment also increases dynorphin mRNA in striatonigral neurons. Thus, the differential effects of dopamine on striatonigral and striatopallidal neurons are mediated by their specific expression of D
1
and D
2
dopamine receptor subtypes, respectively.
Nicotinamide Adenine Dinucleotide Splitting Enzyme: A Characteristic of the Mouse Macrophage
Authors: Artman M. , Seeley R. J.
Published: October 2006

Murine macrophages are endowed with nicotinamide adenine dinucleotide splitting activity that is markedly higher than that of other cells, tissues, or organs of the mouse. This enzyme therefore can be used as a biochemical marker for distinguishing macrophages from other cells of the lymphoreticular system and from polymorphonuclear leukocytes.
Scientific Exchanges and U.S. National Security
Authors: Carlucci Frank , Carey William D.
Published: October 2006

On 9 October 1981, in a letter addressed to The Honorable Frank Carlucci, Deputy Secretary of the Department of Defense, Mr. William D. Carey, Executive Officer and Publisher of
Science
, criticized statements by the Department of Defense concerning scientific exchanges, conferences, and the unclassified, open scientific literature. Mr. Carey's letter and the reply he received from Mr. Carlucci are printed here verbatim.
Paleoflood Hydrology
Authors: Kochel R. Craig , Baker Victor R.
Published: October 2006

The difficult task of estimating recurrence intervals for large floods has long plagued hydrologists because statistical measures fail when return intervals of floods exceed the length of historical data sets. Sediments deposited in the backwaters of large floods may accumulate thick sequences in tributary mouths. Stratigraphic and sedimentologic studies of these sequences combined with radiocarbon dating have established a 10,000-year paleoflood record for the lower Pecos and Devils rivers in southwestern Texas. This technique is rapid and relatively inexpensive and can be used where historical records are short or entirely absent.