bluuebunny/crossref_metadata_2025 huggingface dataset:
Uncoupling of the Spectrin-Based Skeleton from the Lipid Bilayer in Sickled Red Cells
Authors: Liu Shih-Chun , Derick Laura H. , Zhai Sen , Palek Jiri
Published: October 2006

The distribution of spectrin and band 3 in deoxygenated reversibly sickled cells was visualized by immunofluorescence and immunoelectron microscopy. Antibodies against band 3, the major lipid-associated transmembrane protein, labeled the entire cell body, including the entire length of the long protruding spicule, whereas antibodies against spectrin labeled only the cell body and the base region of the spicules. The results suggest that the formation of long spicules during sickling is associated with a continuous polymerization of hemoglobin S polymers, presumably through gaps in the spectrin-actin meshwork, and a subsequent uncoupling of the lipid bilayer from the submembrane skeleton.
Spatial Control of Gut-Specific Gene Expression During
Caenorhabditis elegans
Development
Authors: Aamodt Eric J. , Chung May A. , McGhee James D.
Published: October 2006

The nematode
Caenorhabditis elegans
was transformed with constructs containing upstream deletions of the gut-specific ges-1 carboxylesterase gene. With particular deletions,
ges-1
was expressed, not as normally in the gut, but rather in muscle cells of the pharynx (which belong to a sister lineage of the gut) or in body wall muscle and hypodermal cells (which belong to a cousin lineage of the gut). These observations suggest that gut-specific gene expression in
C. elegans
involves not only gut-specific activators but also multiple repressors that are present in particular nongut lineages.
Three-Dimensional Readout of Flash X-Ray Images of Living Sperm in Water by Atomic-Force Microscopy
Authors: Tomie T. , Shimizu H. , Majima T. , Yamada M. , Kanayama T. , Kondo H. , Yano M. , Ono M.
Published: October 2006

The imaging of living specimens in water by x-ray microscopy can be greatly enhanced with the use of an intense flash x-ray source and sophisticated technologies for reading x-ray images. A subnanosecond x-ray pulse from a laser-produced plasma was used to record the x-ray image of living sea urchin sperm in an x-ray resist. The resist relief was visualized at high resolution by atomic-force microscopy. Internal structure of the sperm head was evident, and the carbon density in a flagellum was estimated from the relief height.
Biological Control of Dissolved Aluminum in Seawater: Experimental Evidence
Authors: Stoffyn Marc
Published: October 2006

Experimental evidence supports the hypothesis that the concentration and distribution of dissolved aluminum in ocean water are controlled by biological activity in the surface waters. The growth of the diatom
Skeletonema costatum
in artificial seawater media spiked with aluminum reduced the aluminum concentration to that actually found in surface open ocean waters (about 0.5 micrograms per liter). Furthermore, aluminum had a catalytic and limiting effect on the growth of the diatoms.
Chemical Characterization of a Hormone That Promotes Cell Arrest in G
2
in Complex Tissues
Authors: Evans Lance S. , Almeida Maria S. , Lynn David G. , Nakanishi Koji
Published: October 2006

A G
2|
factor in the cotyledons of
Pisum sativum
, which arrests the growth of cells in both roots and shoots in the G
2
stage of the cell cycle, has been isolated and identified as trigonelline (
N
-methylnicotinic acid). To our knowledge, trigonelline is the first hormone that effects cell arrest in complex tissues of plants and animals to be chemically identified.
Similarity of Human Mitochondrial Transcription Factor 1 to High Mobility Group Proteins
Authors: Parisi Melissa A. , Clayton David A.
Published: October 2006

Human mitochondrial transcription factor 1 (mtTF1) has been sequenced and is a nucleus-encoded DNA binding protein of 204 amino acids (24,400 daltons). Expression of human mtTF1 in bacteria yields a protein with correct physical properties and the ability to activate mitochondrial DNA promoters. Analysis of the protein's sequence reveals no similarities to any other DNA binding proteins except for the existence of two domains that are characteristic of high mobility group (HMG) proteins. Human mtTF1 is most closely related to a DNA binding HMG-box region in hUBF, a human protein known to be important for transcription by RNA polymerase I.
Limits to Wind Power Utilization
Authors: Gustavson M. R.
Published: October 2006

As wind energy receives increasing attention it is important to understand the noneconomic factors limiting the total power that can be extracted from the wind. These factors are examined here with a macroscopic approach. An upper global limit of 1.3 × 1014watts is arrived at with a sublimit of 2 × 1012watts for the continental United States. Some general conclusions are also reached regarding the sites that would have to be utilized to achieve these levels. Even within these limits, wind energy is seen to offer a potential far larger than many other self-renewing energy sources.
Temporal Pattern as a Cue for Species-Specific Calling Song Recognition in Crickets
Authors: Pollack Gerald S. , Hoy Ronald R.
Published: October 2006

Female crickets can recognize conspecific calling song from its temporal pattern alone. In
Teleogryllus oceanicus
, the song pattern consists of three classes of interpulse intervals arranged in a stereotyped sequence. Females recognize a model song in which the sequential order of intervals is random. This argues against the hypothesis that recognition results from matching auditory input to an internal template of the song.
Fruit, Fiber, Bark, and Resin: Social Organization of a Maya Urban Center
Authors: Folan William J. , Fletcher Laraine A. , Kintz Ellen R.
Published: October 2006

Quantitative analysis of 3579 trees recorded in the Classic Maya city of Cobá, Quintana Roo, Mexico, indicates a strong relation between the location and quantity of certain trees producing fruit, fiber, bark, and resin, high-status vaulted architecture, and their distance from the center of the site out toward the fringes. The relationships suggest agreement between the residence pattern of Cobá and Diego de Landa's 16th-century class-oriented description of Maya towns during preconquest times.
Low-Energy Charged Particle Environment at Jupiter: A First Look
Authors: Krimigis S. M. , Armstrong T. P. , Axford W. I. , Bostrom C. O. , Fan C. Y. , Gloeckler G. , Lanzerotti L. J. , Keath E. P. , Zwickl R. D. , Carbary J. F. , Hamilton D. C.
Published: October 2006

The low-energy charged particle instrument on Voyager was designed to measure the hot plasma (electron and ion energies ≳ 15 and ≳ 30 kiloelectron volts, respectively) component of the Jovian magnetosphere. Protons, heavier ions, and electrons at these energies were detected nearly a third of an astronomical unit before encounter with the planet. The hot plasma near the magnetosphere boundary is predominantly composed of protons, oxygen, and sulfur in comparable proportions and a nonthermal power-law tail; its temperature is about 3 × 10
8
K, density about 5 × 10
–3
per cubic centimeter, and energy density comparable to that of the magnetic field. The plasma appears to be corotating throughout the magnetosphere; no hot plasma outflow, as suggested by planetary wind theories, is observed. The main constituents of the energetic particle population (≳200 kiloelectron volts per nucleon) are protons, helium, oxygen, sulfur, and some sodium observed throughout the outer magnetosphere; it is probable that the sulfur, sodium, and possibly oxygen originate at Io. Fluxes in the outbound trajectory appear to be enhanced from ∼90° to ∼130° longitude (System III). Consistent low-energy particle flux periodicities were not observed on the inbound trajectory; both 5- and 10-hour periodicities were observed on the outbound trajectory. Partial absorption of > 10 million electron volts electrons is observed in the vicinity of the Io flux tube.
Carbon Dioxide in the Ocean Surface: The Homogeneous Buffer Factor
Authors: Sundquist E. T. , Plummer L. N. , Wigley T. M. L.
Published: October 2006

The amount of carbon dioxide that can be dissolved in surface seawater depends at least partially on the homogeneous buffer factor, which is a mathematical function of the chemical equilibrium conditions among the various dissolved inorganic species. Because these equilibria are well known, the homogeneous buffer factor is well known. Natural spatial variations depend very systematically on sea surface temperatures, and do not contribute significantly to uncertainties in the present or future carbon dioxide budget.
Ozone and Temperature Trends Associated with the 11-Year Solar Cycle
Authors: Callis Linwood B. , Natarajan Murali , Nealy John E.
Published: October 2006

Evidence is presented which suggests that trends in the ozone concentration and stratospheric temperature, reported between the early 1960's and 1976, are to a large extent due to solar ultraviolet flux variability associated with the 11-year solar cycle. Radiative-convective-photochemical simulations of ozone and temperature variations have been made with a solar ultraviolet flux variability model. Results for temperatures and ozone concentrations, when compared with published data, show good agreement.
Complementary DNA Sequencing: Expressed Sequence Tags and Human Genome Project
Authors: Adams Mark D. , Kelley Jenny M. , Gocayne Jeannine D. , Dubnick Mark , Polymeropoulos Mihael H. , Xiao Hong , Merril Carl R. , Wu Andrew , Olde Bjorn , Moreno Ruben F. , Kerlavage Anthony R. , McCombie W. Richard , Venter J. Craig
Published: October 2006

Automated partial DNA sequencing was conducted on more than 600 randomly selected human brain complementary DNA (cDNA) clones to generate expressed sequence tags (ESTs). ESTs have applications in the discovery of new human genes, mapping of the human genome, and identification of coding regions in genomic sequences. Of the sequences generated, 337 represent new genes, including 48 with significant similarity to genes from other organisms, such as a yeast RNA polymerase II subunit;
Drosophila
kinesin,
Notch
, and
Enhancer of split
; and a murine tyrosine kinase receptor. Forty-six ESTs were mapped to chromosomes after amplification by the polymerase chain reaction. This fast approach to cDNA characterization will facilitate the tagging of most human genes in a few years at a fraction of the cost of complete genomic sequencing, provide new genetic markers, and serve as a resource in diverse biological research fields.
Monoclonal Antibodies in Diagnosis and Therapy
Authors: Waldmann Thomas A.
Published: October 2006

Monoclonal antibodies have been applied clinically to the diagnosis and therapy of an array of human disorders, including cancer and infectious diseases, and have been used for the modulation of immune responses. Effective therapy using unmodified monoclonal antibodies has, however, been elusive. Recently, monoclonal antibody-mediated therapy has been revolutionized by advances such as the definition of cell-surface structures on abnormal cells as targets for effective monoclonal antibody action, genetic engineering to create less immunogenic and more effective monoclonal antibodies, and the arming of such antibodies with toxins or radionuclides to enhance their effector function.
Vaccinia Virus: A Tool for Research and Vaccine Development
Authors: Moss Bernard
Published: October 2006

Vaccinia virus is no longer needed for smallpox immunization, but now serves as a useful vector for expressing genes within the cytoplasm of eukaryotic cells. As a research tool, recombinant vaccinia viruses are used to synthesize biologically active proteins and analyze structure-function relations, determine the targets of humoral- and cell-mediated immunity, and investigate the immune responses needed for protection against specific infectious diseases. When more data on safety and efficacy are available, recombinant vaccinia and related poxviruses may be candidates for live vaccines and for cancer immunotherapy.
Identification of p53 as a Sequence-Specific DNA-Binding Protein
Authors: Kern Scott E. , Kinzler Kenneth W. , Bruskin Arthur , Jarosz David , Friedman Paula , Prives Carol , Vogelstein Bert
Published: October 2006

The tumor-suppressor gene p53 is altered by missense mutation in numerous human malignancies. However, the biochemical properties of p53 and the effect of mutation on these properties are unclear. A human DNA sequence was identified that binds specifically to wild-type human p53 protein in vitro. As few as 33 base pairs were sufficient to confer specific binding. Certain guanines within this 33-base pair region were critical, as methylation of these guanines or their substitution with thymine-abrogated binding. Human p53 proteins containing either of two missense mutations commonly found in human tumors were unable to bind significantly to this sequence. These data suggest that a function of p53 may be mediated by its ability to bind to specific DNA sequences in the human genome, and that this activity is altered by mutations that occur in human tumors.
Initial Pioneer Venus Magnetic Field Results: Nightside Observations
Authors: Russell C. T. , Elphic R. C. , Slavin J. A.
Published: October 2006

Initial observations by the Pioneer Venus magnetometer on the nightside of Venus frequently reveal moderately strong fields from 20 to 30 nanoteslas. However, there is little evidence that these fields arise from an internal dynamo since they are mainly horizontal and vary from orbit to orbit. Determining a precise upper limit to the intrinsic moment awaits further processing. This limit is expected to be much less than 10
22
gauss-cubic centimeters.
Sperm in "Parthenogenetic" Freshwater Gastrotrichs
Authors: Weiss Mitchell J. , Levy Dennis P.
Published: October 2006

Freshwater members of the phylum Gastrotricha have been considered obligate parthenogens. In
Lepidodermella squammata
, the species for which there is most evidence for parthenogenesis, sperm have been discovered. This finding will necessitate reexamination of the nature of sexuality and life cycles and of the concept of "species" in freshwater gastrotrichs.
Magnetite in CI Carbonaceous Meteorites: Origin by Aqueous Activity on a Planetesimal Surface
Authors: Kerridge John F. , Mackay Alan L. , Boynton William V.
Published: October 2006

The composition and morphology of magnetite in CI carbonaceous meteorites appear incompatible with a nebular origin. Mineralization on the meteorite parent body is a more plausible mode of formation. The iodine-xenon age of this material therefore dates an episode of secondary mineralization on a planetesimal rather than the epoch of condensation in the primitive solar nebula.
Giant Interneurons Mediating Equilibrium Reception in an Insect
Authors: Hartman H. Bernard , Walthall W. William , Bennett Lisa P. , Stewart Randall R.
Published: October 2006

In the burrowing cockroach
Arenivaga
, two giant interneurons in each connective of the ventral nerve cord provide gravity orientation information. The interneurons receive input from plumb bob-like equilibrium receptors on the ventral surface of the cerci. Our results support the theory that the cerci of cockroaches are specialized equilibrium organs.
The Double Quasar 0957+561: A Radio Study at 6-Centimeters Wavelength
Authors: Roberts D. H. , Greenfield P. E. , Burke B. F.
Published: October 2006

The optical double quasar 0957+561 has been interpreted as the gravitational double image of a single object. A radio map made with the Very Large Array of the National Radio Astronomy Observatory shows unresolved sources coincident with the optical images as well as a complex of related extended emission. Although the results cannot rule out the gravitational lens hypothesis, the complex radio structure is more easily interpreted as two separate quasars. The optical and radio properties of the two quasars are so similar that the two must have been formed at the same time with similar initial conditions.
Giant Larvacean Houses: Observations from Deep Submersibles
Authors: Barham Eric G.
Published: October 2006

The abundance of large, previously unknown larvacean feeding structures in the deep ocean is a striking contrast to the rarity of such forms taken in net hauls. In some areas, abandoned houses and their disintegrated parts provide a substrate for other organisms and contribute to organic aggregates.
The Viscous Sublayer at the Sea Floor
Authors: Caldwell D. R. , Chriss T. M.
Published: October 2006

A 0.6-centimeter-thick sublayer was found in horizontal flow profiles obtained by traversing a heated thermistor from 19 centimeters above to 2 centimeters below the water-sediment interface in 200-meter-deep water on the Oregon continental shelf. In this sublayer the speed of the current varies linearly with distance above the sediment. Estimates of viscous stress from this sublayer and turbulent stress from the profile agree within 5 percent. Stress calculated from a current-meter spectrum agrees within its 95 percent confidence limits.
The Rise of the Angiosperms: A Genecological Factor
Authors: Mulcahy David L.
Published: October 2006

In the primitive angiosperms, closed carpels are believed to have evolved as protection for ovules, which would otherwise be injured by animal pollinators. The hypothesis is presented that, whatever the origin and other functions of angiosperms, insect pollination and closed carpels may, in combination, reduce the influence of random variation on pollen tube competition, thus enhancing the ability of natural selection to act on the gametophytic phase of the life cycle. The microgametophytic phase represented by vast numbers of haploid individuals can then serve, by insect pollination and closed carpels, as a screen against any genome not functioning with a high degree of metabolic vigor. Poorly balanced genomes could thus be eliminated at relatively little cost. Insect-pollinated angiosperms would therefore benefit from positive aspects of sexual recombination. Such a system may have allowed the angiosperms to undergo their rise to dominance.
Amino Acids in an Antarctic Carbonaceous Chondrite
Authors: Cronin John R. , Pizzarello Sandra , Moore Carleton B.
Published: October 2006

Amino acids have been found in aqueous extracts of a C2 carbonaceous chondrite recovered from Antarctica. The composition of the amino acids strongly suggests that they have a meteoritic origin. Comparison of these results with those obtained with other C2 chondrites supports the view that Antarctic meteorites have not been significantly altered by terrestrial processes since their fall.
Experimental Coarsening of Antiphase Domains in a Silicate Mineral
Authors: Carpenter Michael A.
Published: October 2006

Combined annealing experiments and observations by transmission electron microscopy show that in natural pigeonite crystals antiphase domains coarsen approximately according to a rate law in which the tenth power of the average domain size is proportional to time. This result suggests that certain cations (possibly Ca
2+
) were segregated preferentially onto the antiphase boundaries. The domain size in samples quenched from above the high-low transformation temperature is large and apparently independent of annealing time and temperature. It appears that large domains can be generated either by very fast or by very slow cooling; thus the estimation of geological cooling rates from the sizes of antiphase domains in natural samples becomes rather difficult.
Photometric Observations of Jupiter at 2400 Angstroms
Authors: Hord Charles W. , West Robert A. , Simmons Karen E. , Coffeen David L. , Sato Makiko , Lane Arthur L. , Bergstralh Jay T.
Published: October 2006

The photopolarimeter instrument on Voyager 2 was used to obtain a map of Jupiter at an effective wavelength of 2400 angstroms. Analysis of a typical north-south swath used to make this map shows strong absorption at high latitudes by a molecular or particulate constituent in the Jovian atmosphere. At 65° north latitude, the absorbing constituent extends to altitudes above the 50-millibar pressure level.
RNA Secondary Structure Repression of a Muscle-Specific Exon in HeLa Cell Nuclear Extracts
Authors: Clouet d'Orval Beatrice , d'Aubenton Carafa Yves , Sirand-Pugnet Pascal , Gallego Maria , Brody Edward , Marie Joelle
Published: October 2006

The chicken β-tropomyosin pre-messenger RNA (pre-mRNA) is spliced in a tissue-specific manner to yield messenger RNA's (mRNA's) coding for different isoforms of this protein. Exons 6A and 6B are spliced in a mutually exclusive manner; exon 6B was included in skeletal muscle, whereas exon 6A was preferred in all other tissues. The distal portion of the intron upstream of exon 6B was shown to form stable double-stranded regions with part of the intron downstream of exon 6B and with sequences in exon 6B. This structure repressed splicing of exon 6B to exon 7 in a HeLa cell extract. Derepression of splicing occurred on disruption of this structure and repression followed when the structure was re-formed, even if the structure was formed between two different RNA molecules. Repression leads to inhibition of formation of spliceosomes. Disrupting either of the two double-stranded regions could lead to derepression, whereas re-forming the helices by suppressor mutations reestablished repression. These results support a simple model of tissue-specific splicing in this region of the pre-mRNA.
Memory Formation: Evidence for a Specific Neurochemical System in the Amygdala
Authors: Gallagher Michela , Kapp Bruce S. , Musty Richard E. , Driscoll Patricia A.
Published: October 2006

β-Adrenergic antagonists injected into the amygdala complex of rats trained in a passive avoidance task produced time-dependent and dose-dependent decreases in retention of the task. In addition, the effects observed with β-adrenergic antagonists were both stereospecific and reversed by norepinephrine. The results support a role for an amygdala β-adrenergic system in memory processes.
Thermal Evolution of Plutons: A Parameterized Approach
Authors: Spera Frank
Published: October 2006

A conservation-of-energy equation has been derived for the spatially averaged magma temperature in a spherical pluton undergoing simultaneous crystallization and both internal (magma) and external (hydrothermal fluid) thermal convection. The model accounts for the dependence of magma viscosity on crystallinity, temperature, and bulk composition; it includes latent heat effects and the effects of different initial water concentrations in the melt and quantitatively considers the role that large volumes of circulatory hydrothermal fluids play in dissipating heat. The nonlinear ordinary differential equation describing these processes has been solved for a variety of magma compositions, initial temperatures, initial crystallinities, volume ratios of hydrothermal fluid to magma, and pluton sizes. These calculations are graphically summarized in plots of the average magma temperature versus time after emplacement. Solidification times, defined as the time necessary for magma to cool from the initial emplacement temperature to the solidus temperature vary as

R
1,3

, where
R
is the pluton radius. The solidification time of a pluton with a radius of 1 kilometer is 5 × 10
4
years; for an otherwise identical pluton with a radius of 10 kilometers, the solidification time is ∼10
6
years. The water content has a marked effect on the solidification time. A granodiorite pluton with a radius of 5 kilometers and either 0.5 or 4 percent (by weight) water cools in 3.3 × 10
5
or 5 × 10
4
years, respectively. Convection solidification times are usually but not always less than conduction cooling times.
Phenolic Ethers in the Organic Polymer of the Murchison Meteorite
Authors: Hayatsu Ryoichi , Winans Randall E. , Scott Robert G. , McBeth Robert L. , Moore Leon P. , Studier Martin H.
Published: October 2006

Seven phenolic acids and many nonphenolic organic acids, including large amounts of meta-hydroxy (3-hydroxy) benzoic acid and 3-hydroxy-1,5-benzenedicarboxylic acid, were obtained from the organic polymer of the Murchison C2 chondrite upon oxidation with alkaline cupric oxide. The phenolic acids apparently were derived from phenolic ethers in the polymer, which in turn probably were formed from carbon monoxide and hydrogen by catalytic Fischer-Tropsch type reactions in the solar nebula. In contrast, terrestrial polymers such as lignin, humic acid, and coal yield mainly para-hydroxy (4-hydroxy) benzene derivatives by the same oxidation procedure.
Computer Models of Crystal Growth
Authors: Gilmer G. H.
Published: October 2006

Dynamic models of crystal surfaces have provided new insights into the crystal growth process. The effects of surface roughening, dislocations, and impurities have been assessed. Certain impurities have been found to cause a larger increase in the growth rate than screw dislocations.
Corrections in the Pioneer Venus Sounder Probe Gas Chromatographic Analysis of the Lower Venus Atmosphere
Authors: Oyama Vance I. , Carle Glenn C. , Woeller Fritz
Published: October 2006

Misidentification of two peaks from the Pioneer Venus sounder probe gas chromatograph (SPGC), also formerly known as the LGC, gave rise to quantitative errors in the abundances of oxygen, argon, and carbon monoxide. The argon abundance is estimated at 67 parts per million and that of carbon monoxide at 20 parts per million. At this time, no estimates for the oxygen abundance can be made.
Multipolymer Systems
Authors: Alfey Turner , Schrenk Walter J.
Published: October 2006

Different polymers can be combined to yield a wide variety of composite materials: layered sheets and films, homogeneous and heterogeneous blends, interpenetrating polymer networks, bicomponent fibers, and others. Some properties of a multipolymer material are roughly additive, but synergistic interactions can yield properties and performances superior to those of the individual constituents. Consequently, the use of polymers in combination is a rapidly growing component of polymer materials technology.
Biopolyester Membranes of Plants: Cutin and Suberin
Authors: Kolattukudy P. E.
Published: October 2006

Cutin, a biopolyester composed of hydroxy and epoxy fatty acids, is the barrier between the aerial parts of higher plants and their environment. Suberin, a polymer containing aromatics and polyesters, functions as a barrier in underground parts, wound surfaces, and a variety of internal organs. The composition and probable structure of these polymers are discussed. The biosynthesis of the hydroxy, epoxy, and dicarboxylic acids of the polyesters from the common cellular fatty acids is elucidated. An extracellular enzyme transfers the hydroxy and epoxyacyl moieties from their coenzyme A derivatives to the growing polyester. The enzymes acting in the biodegradation of the polyesters have been isolated from fungi, pollen, and mammals and characterized. The function and possible practical implications of these polyester barriers are briefly discussed.
Risks of Risk Decisions
Authors: Starr Chauncey , Whipple Chris
Published: October 2006

The analytical approaches utilized for evaluating the acceptability of technological risk originate from analogies to financial cost-benefit risk analysis. These analogies appear generally valid for viewing risk from a societal basis, but are not applicable to individual risk assessments. Conflicts arising from these different views of risk assessment provide insights to the origins of individual, intuitive evaluations. Societal risk decisions made under conflict represent political compromises, and the resulting decision process creates substantial conflict costs. The pragmatic use of quantitative risk criteria (safety targets) may be useful in reducing these costs.
Hormone-Induced Sexual Differentiation of Brain and Behavior in Zebra Finches
Authors: Gurney Mark E. , Konishi Masakazu
Published: October 2006

The male zebra finch sings, whereas the female does not. This behavioral dimorphism is correlated with the presence of morphological sex differences within the neural substrate that mediates this behavior, the song system. When a female chick is exposed to 17β-estradiol her song system is subsequently masculinized. Either testosterone or 5α-dihydrotestosterone may then induce such a female to sing when an adult.
Fossilized Viscera in Primitive Echinoderms
Authors: Haugh Bruce N. , Bell Bruce M.
Published: October 2006

Fossilized visceral organs in ancient echinoderms have anatomical features that were not inferred from the anatomy of extant relatives. The unique visceral anatomy of extinct echinoderms demonstrates the need to integrate paleontological and neontological analyses in order to fully evaluate this and other morphologically complex phyla. Comparative analysis of the visceral anatomy of extinct and extant echinoderms necessitates regrouping these animals into three new subphyla. Similar analyses for other metazoan groups could yield equally significant results.
Sources of Continental Crust: Neodymium Isotope Evidence from the Sierra Nevada and Peninsular Ranges
Authors: DePaolo Donald J.
Published: October 2006

Granitic rocks from batholiths of the Sierra Nevada and Peninsular Ranges exhibit initial
143
Nd/
144
Nd ratios that vary over a large range and correlate with
87
Sr/
86
Sr ratios. The data suggest that the batholiths represent mixtures of materials derived from (i) chemically depleted mantle identical to the source of island arcs and (ii) old continental crust, probably sediments or metasediments with a provenance age of ∼1.6 × 10
9
years. These conclusions are consistent with a model for continental growth whereby new crustal additions are repeatedly extracted from the same limited volume of the upper mantle, which has consequently become depleted in elements that are enriched in the crust. There is little evidence that hydrothermally altered, subducted oceanic crust is a primary source of the magmas.
Voyager Detection of Nonthermal Radio Emission from Saturn
Authors: Kaiser M. L. , Desch M. D. , Warwick J. W. , Pearce J. B.
Published: October 2006

The planetary radio astronomy experiment on board the Voyager spacecraft has detected bursts of nonthermal radio noise from Saturn occurring near 200 kilohertz, with a peak flux density comparable to higher frequency Jovian emissions. The radiation is right-hand polarized and is most likely emitted in the extraordinary magnetoionic mode from Saturn's northern hemisphere. Modulation that is consistent with a planetary rotation period of 10 hours 39.9 minutes is apparent in the data.
Juvenile Hormone Induction of Biting Behavior in
Culex
Mosquitoes
Authors: Meola Roger W. , Petralia Ronald S.
Published: October 2006

Juvenile hormone deprivation caused by surgical removal of corpora allata shortly after adult emergence blocked the initiation of biting behavior in
Culex pipiens
and
Culex quinquefasciatus
. Reimplantation of corpora allata or injection of a synthetic juvenile hormone (JH-I) corrected the juvenile hormone deficiency and restored biting behavior. Ovariectomy experiments demonstrated that this behavioral effect of juvenile hormone was independent of ovarian involvement.
Anomalous Sounds from the Entry of Meteor Fireballs
Authors: Keay Colin S. L.
Published: October 2006

A very bright fireball observed over New South Wales in 1978 produced anomalous sounds clearly audible to some of the observers. An investigation of the phenomenon indicates that bright fireballs radiate considerable electromagnetic energy in the very-low-frequency (VLF) region of the spectrum. A mechanism for the production of VLF emissions from the highly energetic wake turbulence of the fireball is proposed. Trials with human subjects revealed a very extended range of thresholds for the perception of electrically excited sounds among a sample population, particularly when the VLF electric field excites surface acoustic waves in surrounding objects. This fact, together with variable propagation effects and local conditions, can account for the sporadic distribution of reports of anomalous sounds from fireballs and auroras.
Is the Proton Stable?
Authors: Goldhaber M. , Langacker P. , Slansky R.
Published: October 2006

For nearly 50 years there has been a strong belief that the proton is absolutely stable. The current experimental upper bound on its decay rate is less than one proton decay per 3 tons of matter per year, which corresponds to a mean lifetime of more than 10
30
years. Even more sensitive searches for proton decay are now in progress. These are partially motivated by the development of a class of models that combine the presently accepted theories of electromagnetic, weak, and strong interactions into an elegant unified form. Some of these theories predict a proton lifetime short enough for the decays to be detectable by the proposed experiments. If the proton is unstable, a plausible explanation can be given for the apparent excess of matter over antimatter in the universe.
Applications of Laser Radiation Pressure
Authors: Ashkin A.
Published: October 2006

Use of lasers has revolutionized the study and applications of radiation pressure. Light forces have been achieved which strongly affect the dynamics of individual small particles. It is now possible to optically accelerate, slow, stably trap, and manipulate micrometer-sized dielectric particles and atoms. This leads to a diversity of new scientific and practical applications in fields where small particles play a role, such as light scattering, cloud physics, aerosol science, atomic physics, quantum optics, and high-resolution spectroscopy.
Stress Anomaly Accompanying the 1979 Lytle Creek Earthquake: Implications for Earthquake Prediction
Authors: Clark Bruce R.
Published: October 2006

An unusual stress transient was recorded 15 kilometers from the epicenter of the Lytle Creek earthquake in southern California. It was observed at the recording site as an increased shear stress parallel to the fault surface and with the proper sense of shear to have triggered the earthquake. The anomaly began 2 to 4 weeks before the earthquake and lasted for 3 months.
Rural Africa: Modernization, Equity, and Long-Term Development
Authors: Lele Uma
Published: October 2006

Prospects for rural development in sub-Saharan Africa appear to be much poorer than in the rest of the developing world, especially since the oil price increases. If present trends continue, African dependence on food imports will increase. Despite the rhetorical acknowledgment of the importance of the agricultural and rural sector, most African countries are not giving that sector the needed priority in their policies and budgets. Indeed, the rural sector is heavily taxed for the support of urban modernization. Large investments by foreign donors in the rural sector have had little overall effect. Donors need to adopt a longer perspective on development and to make greater efforts to promote indigenous capacities for policy, planning, and administration. Their investments need to be geared more to broad-based higher education and training and to transport and communications.
Crystal and Molecular Structure of a Pentagonal Dodecahedrane
Authors: Paquette Leo A. , Balogh Douglas W. , Usha R. , Kountz Dennis , Christoph Gary G.
Published: October 2006

The successful synthesis of a pentagonal dodecahedrane molecule has been achieved. Obtained by a sequence of 20 stereochemically controlled steps beginning with the readily available cyclopentadienide anion, the 1,16-dimethyl derivative has
D

3
d

symmetry and unusual physical properties. The x-ray crystal structure shows that the alkyl groups cause only small distortions from pure dodecahedral symmetry.
Geologic Remote Sensing
Authors: Goetz Alexander F. H. , Rowan Lawrence C.
Published: October 2006

Remote-sensing techniques are now being used routinely in geologic interpretation for mineral and energy exploration, plant siting, waste disposal, and the development of models for regional and continental tectonics. New spaceborne methods and associated technologies are being developed to produce data from which geologic information about large areas can be derived much more rapidly than by conventional techniques.
Trajectories of the Mount St. Helens Eruption Plume
Authors: Danielsen Edwin F.
Published: October 2006

The plume of the major eruption of Mount St. Helens on 18 May 1980 penetrated 10 to 11 kilometers into the stratosphere, attaining heights of 22 to 23 kilometers. Wind shears rapidly converted the plume from an expanding vertical cone to a thin, slightly inclined lamina. The lamina was extruded zonally in the stratosphere as the lower part moved eastward at jet stream velocities, while the upper part slowly moved westward in the region of nonsteady transition from the westerlies to the summer stratospheric easterlies. Trajectories computed to position the NASA U-2 aircraft for sampling in the plume are described. Plume volume after 8 hours of strong volcanic emission is estimated at 2 × 10
6
cubic kilometers. Only about 1 percent of this volume is attributed to the volcano; the rest was entrained from the environment.
Changes in Stratospheric Water Vapor Associated with the Mount St. Helens Eruption
Authors: Murcray David G. , Murcray Frank J. , Barker D. Boyd , Mastenbrook H. John
Published: October 2006

A frost point hygrometer designed for aircraft operation was included in the complement of instruments assembled for the NASA U-2 flights through the plume of Mount St. Helens. Measurements made on the 22 May flight showed the water vapor to be closely associated with the aerosol plume. The water vapor mixing ratio by mass in the plume was as high as 40 × 10
–6
. This compares with values of 2 × 10
–6
to 3 × 10
–6
outside of the plume.
Parasitoids as Selective Agents in the Symbiosis Between Lycaenid Butterfly Larvae and Ants
Authors: Pierce Naomi E. , Mead Paul S.
Published: October 2006

The larvae of
Glaucopsyche lygdamus
(Lepidoptera: Lycaenidae) secrete substances that attract ants. In two field sites in Colorado, tending ants protect caterpillars of
G. lygdamus
from attack by braconid and tachinid parasitoids. This protection may have been an important feature in the evolution of the association between lycaenid larvae and ants.
Calcite Dissolution: An in situ Study in the Panama Basin
Authors: Thunell Robert C. , Keir Robin S. , Honjo Susumu
Published: October 2006

The results of an in situ study of calcite dissolution in the Panama Basin indicate that the rate of dissolution in the water column increases suddenly below a water depth of about 2800 meters. This coincides with the depth at which the calcium carbonate content of surface sediments begins to decrease rapidly or the sedimentary lysocline. Since this level of increased dissolution both in the water column and on the sea floor does not appear to be related to the transition from supersaturation to undersaturation with respect to carbonate, there may be a kinetic origin for the lysocline in this region.
Method for Estimation of Ocean Current Velocity from Satellite Images
Authors: Mollo-Christensen Erik , Cornillon Peter , Mascarenhas Affonso Da S.
Published: October 2006

Barotropic instability waves on a shear interface propagate at the average speed of the water on the two sides. Assuming the instability to be excited by tidal oscillations, the phase speed is the wavelength divided by the tidal period. If the water is at rest on one side of the shear layer the current speed on the other side can be calculated. This method, applied to the Gulf Stream beyond Cape Hatteras as seen in satellite images, gives estimates of current speed in general agreement with in situ observations.
Radioactive Waste Disposal in Thick Unsaturated Zones
Authors: Winogard Isaac J.
Published: October 2006

Portions of the Great Basin are undergoing crustal extension and have unsaturated zones as much as 600 meters thick. These areas contain multiple natural barriers capable of isolating solidified toxic wastes from the biosphere for tens of thousands to perhaps hundreds of thousands of years. An example of the potential utilization of such arid zone environments for toxic waste isolation is the burial of transuranic radioactive wastes at relatively shallow depths (15 to 100 meters) in Sedan Crater, Yucca Flat, Nevada. The volume of this man-made crater is several times that of the projected volume of such wastes to the year 2000. Disposal in Sedan Crater could be accomplished at a savings on the order of $0.5 billion, in comparison with current schemes for burial of such wastes in mined repositories at depths of 600 to 900 meters, and with an apparently equal likelihood of waste isolation from the biosphere.
Characterization of Plutonium in Maxey Flats Radioactive Trench Leachates
Authors: Cleveland Jess M. , Rees Terry F.
Published: October 2006

Plutonium in trench leachates at the Maxey Flats radioactive waste disposal site exists as dissolved species, primarily complexes of the tetravalent ion with strong organic ligands such as ethylenediaminetetraacetic acid. The complexes are not sorbed well by sediment and are only partly precipitated by ferric hydroxide. These results indicate the importance of isolating radioactive waste from organic matter.
U1-Specific Protein C needed for Efficient Complex Formation of U1 snRNP with a 5′ Splice Site
Authors: Heinrichs Volker , Bach Montserrat , Winkelmann Gerd , Lührmann Reinhard
Published: October 2006

One of the functions of U1 small nuclear ribonucleoprotein (snRNP) in the splicing reaction of pre-mRNA molecules is the recognition of the 5′ splice site. U1 snRNP proteins as well as base-pair interactions between U1 snRNA and the 5′ splice site are important for the formation of the snRNP-pre-mRNA complex. To determine which proteins are needed for complex formation, the ability of U1 snRNPs gradually depleted of the U1-specific proteins C, A, and 70k to bind to an RNA molecule containing a 5′ splice site sequence was studied in a nitrocellulose filter binding assay. The most significant effect was always observed when protein C was removed, either alone or together with other U1-specific proteins; the binding was reduced by 50 to 60%. Complementation of protein C-deficient U1 snRNPs with purified C protein restored their 5′ splice site binding activity. These data suggest that protein C may potentiate the base-pair interaction between U1 RNA and the 5′ splice site.
Antigen Presentation Requires Transport of MHC Class I Molecules from the Endoplasmic Reticulum
Authors: Cox Josephine H. , Yewdell Jonathan W. , Eisenlohr Laurence C. , Johnson Philip R. , Bennink Jack R.
Published: October 2006

The role of exocytosis of major histocompatibility complex (MHC) class I molecules in the presentation of antigens to mouse cytotoxic T lymphocytes (CTLs) was examined by use of a recombinant vaccinia virus that expresses the E19 glycoprotein from adenovirus. E19 blocked the presentation of vaccinia and influenza virus proteins to CTLs in a MHC class I allele-specific manner identical to its inhibition of MHC class I transport from the endoplasmic reticulum. This finding indicates that (i) the relevant parameter for antigen presentation is the rate of MHC class I molecule exocytosis, not the level of class I cell surface expression, and (ii) association of class I molecules with antigen is likely to occur within the endoplasmic reticulum.
Association Reaction in Forsterite Under Shock Compression
Authors: Syono Yasuhiko , Goto Tsuneaki , Takei Humihiko , Tokonami Masayasu , Nobugai Kohji
Published: October 2006

Transmission electron microscopic observation of forsterite (Mg
2
SiO
4
) shocked to peak pressures of 78 to 92 gigapascals revealed that forsterite breaks down to an assemblage of MgO plus MgSiO
3
glass. This strongly supports the interpretation that the high-pressure phase of forsterite under shock compression is due to the assemblage of MgSiO
3
perovskite plus MgO.
High-Latitude Stratospheric Aerosols Measured by the SAM II Satellite System in 1978 and 1979
Authors: McCormick M. P. , Chu W. P. , Grams G. W. , Hamill Patrick , Herman B. M. , McMaster L. R. , Pepin T. J. , Russell P. B. , Steele H. M. , Swissler T. J.
Published: October 2006

Results of the first year of data collection by the SAM (Stratospheric Aerosol Measurement) II satellite system are presented. Almost 10,000 profiles of stratospheric aerosol extinction in the Arctic and Antarctic regions are used to construct plots of weekly averaged aerosol extinction versus altitude and time and stratospheric optical depth versus time. Corresponding temperature fields are presented. These data show striking similarities in the aerosol behavior for corresponding seasons. Wintertime polar stratospheric clouds that are strongly correlated with temperature are documented. They are much more prevalent in the Antarctic stratosphere during the cold austral winter and increase the stratospheric optical depths by as much as an order of magnitude for a period of about 2 months. These clouds might represent a sink for stratospheric water vapor and must be considered in the radiative budget for this region and time.
Vibratory Communication Through Living Plants by a Tropical Wandering Spider
Authors: Rovner Jerome S. , Barth Friedrich G.
Published: October 2006

Female
Cupiennius salei
pheromone on banana and
Agave
plants elicits patterned oscillations by the male. Resulting pulse trains of vibrations through the leaf average 76 hertz. The brief vibratory response by the otherwise immobile female hidden up to at least 1 meter away on another leaf guides the male across the plant to her location. Reciprocal signaling continues in the presence of random noise that masks the male's airborne sounds.
Computer Simulation in Chemical Kinetics
Authors: Edelson David
Published: October 2006

Numerical methods for modeling complex chemical reactions are being used to gain insight into the mechanisms of these systems as well as to provide a capability for predicting their behavior from a knowledge of elementary physical and chemical processes. The state of the art is reviewed, and some projections about likely future developments are made.
Close-Range Attraction of Female Oriental Fruit Moths to Herbal Scent of Male Hairpencils
Authors: Baker Thomas C. , Nishida Ritsuo , Roelofs Wendell L.
Published: October 2006

A blend of ethyl
trans
-cinnamate, methyl 2-epijasmonate, methyl jasmonate, and (
R
)-(–)- mellein, identified from the hairpencils of male Oriental fruit moths, attracts sex pheromone-releasing females several centimeters away. The chemicals thereby duplicate the behavioral effect elicited by hairpencil-displaying males during courtship; the chemicals also produce the herbal scent emanating from the hairpencils.
Copernicus Crater Central Peak: Lunar Mountain of Unique Composition
Authors: Pieters Carle M.
Published: October 2006

Olivine is identified as the major mafic mineral in a central peak of Copernicus crater. Information on the mineral assemblages of such unsampled lunar surface material is provided by near infrared reflectance spectra (0.7 to 2.5 micrometers) obtained with Earth-based telescopes. The composition of the deep-seated material comprising the Copernicus central peak is unique among measured areas. Other lunar terra areas and the wall of Copernicus exhibit spectral characteristics of mineral assemblages comparable to the feldspathic breccias returned by the Apollo missions, with low-calcium orthopyroxene being the major mafic mineral.