bluuebunny/crossref_metadata_2025 huggingface dataset:
Mountain Bluebirds: Experimental Evidence Against Altruism
Authors: Power Harry W.
Published: October 2006

The frequency of true altruism in nature requires assessment because, if true altruism is common, Darwin's theory of natural selection is inadequate to account for all of evolution. An experiment provided birds with the opportunity to behave truly altruistically. One member of each of 25 wild pairs was collected. Ten of these were replaced naturally by courting birds, or consorts. Only one consort fostered the young of her prospective mate, and her behavior was interpretable as a reproductive error. Other consorts behaved reproductively selfishly.
Intermolecular Electron Transfer by Quantum Mechanical Tunneling
Authors: Miller John R.
Published: October 2006

The transfer of electrons from one molecule to another by quantum mechanical tunneling has recently been implicated in biological electron transport. This report describes observations of electron transfer between aromatic molecules in a rigid matrix, in which electrons apparently tunnel through tens of angstroms of inert solvent. The kinetics tend to confirm the tunneling process, which is likely to be an important means of electron transfer when diffusion is blocked by steric factors or immobilization of the reactants.
Distributive Computer Networking: Making It Work on a Regional Basis
Authors: Cornew Ronald W. , Morse Philip M.
Published: October 2006

After 4 years of operation the NERComP network is now a self-supporting success. Some of the reasons for its success are that (i) the network started small and built up utilization; (ii) the members, through monthly trustee meetings, practiced "participatory management" from the outset; (iii) unlike some networks, NERComP appealed to individual academic and research users who were terminal-oriented and who controlled their own budgets; (iv) the compactness of the New England region made it an ideal laboratory for testing networking concepts; and (v) a dedicated staff was willing to work hard in the face of considerable uncertainty. While the major problems were "political, organizational and economic" we have found that they can be solved if the network meets real needs.

We have also found that it is difficult to proceed beyond a certain point without investing responsibility and authority in the networking organization. Conversely, there is a need to distribute some responsibilities such as marketing and user services back to the member institutions. By adopting a modest starting point and achieving limited goals the necessary trust and working relationships between institutions can be built. In our case the necessary planning has been facilitated by recognizing three distinct network functions: governance, user services, and technical operations. Separating out the three essential networking tasks and dealing with each individually through advisory committees, each with its own staff coordinator, has overcome a distracting tendency to address all issues at once. It has also provided an element of feedback between the end user and the supplier not usually present in networking activity.

The success of NERComP demonstrates that a distributive-type network can work. Our experiences in New England—which, because of its numerous colleges and universities free from domination by any single institution, is a microcosm for academic computing in the United States—indicate that such networks are best structured in a hierarchical form. This suggests that national networking should be based in part on the more than 30 existing state and regional networks.

With the groundwork now laid, we expect to see links among existing regional networks to complement development efforts now occurring at the national level. With Greenberger and others, we believe that one or more networking organizations devoted to the management issues discussed in this article will be required to facilitate resource sharing on a national scale. Because of their experience with these problems and their ability to provide service in many areas of the country through existing facilities, regional networks have a major role to play.
Mediation of the Attachment or Fusion Step in Vesicular Transport by the GTP-Binding Ypt1 Protein
Authors: Segev Nava
Published: October 2006

The function of the guanosine triphosphate (GTP)-binding protein Ypt1 in regulating vesicular traffic was studied in a cell-free system that reconstitutes transport from the endoplasmic reticulum to the Golgi. Blocking the Ypt1 protein activity resulted in accumulation of vesicles that act as an intermediate passing between the two compartments. The Ypt1 protein was found on the outer side of these vesicles. The transport process is completed by fusion of these vesicles with the acceptor compartment, and Ypt1 protein activity was needed for this step. Thus, a specific GTP-binding protein is required for either attachment or fusion (or both) of secretory vesicles with the acceptor compartment during protein secretion.
Bile, Prolactin, and the Maternal Pheromone
Authors: Moltz Howard , Leidahl Lois C.
Published: October 2006

When bile from females that had been lactating for 21 days was injected into the cecum of male rats it induced release of a maternal pheromone. Males injected with bile drawn from females in which prolactin had been inhibited, or from females that had been lactating for only 5 days, did not emit the pheromone. These data suggest a sex difference in the way prolactin alters the composition of bile so that the female can emit the maternal pheromone while the male normally cannot.
Doubly Charged Negative Atomic Ions of Hydrogen
Authors: Anbar Michael , Schnitzer Rafael
Published: October 2006

The existence of a relatively long-lived doubly charged negative atomic ion H
2–
(and D
2–
), isoelectronic with the lithium atom, has been demonstrated by mass spectrometry through a combined analysis of ion energy, velocity, and momentum. This species, formed in a hydrogen plasma, has a half-life of 2.3 × 10
–8
seconds before it spontaneously dissociates to produce H
–
ions.
Methylation of Selenium in the Aquatic Environment
Authors: Chau Y. K. , Wong P. T. S. , Silverberg B. A. , Luxon P. L. , Bengert G. A.
Published: October 2006

Conversion of inorganic and organic selenium compounds to volatile selenium compounds (dimethyl selenide, dimethyl diselenide, and an unknown compound) by microorganisms in lake sediment has been observed. This conversion could also be effected by pure cultures of bacteria and fungi. Such transformations are significant in the transportation and cycling of elements in the environment.
Properties of the Background Global Aerosol and Their Effects on Climate
Authors: Shaw Glenn E.
Published: October 2006

Properties of the aerosols above Hawaii, Alaska, and the South Pole are derived from sun photometry at several wavelengths. The mass loading of aerosol material is several milligrams per square meter. At the South Pole the mean particle radius is 0.04 micrometer; at Hawaii in March 1975 there was a thin volcanic layer with a mean particle radius of 0.1 micrometer. The aerosols cause heating of the earth-atmosphere system at the poles and cooling at low latitudes.
Establishment of Cell Type by Compartmentalized Activation of a Transcription Factor
Authors: Margolis Peter , Driks Adam , Losick Richard
Published: October 2006

Early in the process of spore formation in
Bacillus subtilis
a septum is formed that partitions the sporangium into daughter cells called the forespore and the mother cell. The daughter cells each have their own chromosome but follow dissimilar programs of gene expression. Differential gene expression in the forespore is now shown to be established by the compartmentalized activity of the transcription factor σ
F
. The σ
F
factor is produced prior to septation, but is active only in the forespore compartment of the post-septation sporangium. The σ
F
factor is controlled by the products of sporulation operons
spoIIA
and
spoIIE
, which may be responsible for confining its activity to one of the daughter cells.
Cloning of a Serotonin Transporter Affected by Antidepressants
Authors: Hoffman Beth J. , Mezey Eva , Brownstein Michael J.
Published: October 2006

A complementary DNA clone for a serotonin (5HT) transporter has been isolated from rat basophilic leukemia cells. The complementary DNA sequence predicts a 653-amino acid protein with 12 to 13 putative transmembrane domains. The 5HT transporter has significant homology to the γ-aminobutyric acid, dopamine, and norepinephrine transporters. Uptake by CV-1 cells expressing the transporter complementary DNA resembles 5HT uptake by platelets and brain synaptosomes; it is sensitive to antidepressants, amphetamine derivatives, and cocaine.
Selective Depletion in HIV Infection of T Cells that Bear Specific T Cell Receptor V
β
Sequences
Authors: Imberti Luisa , Sottini Alessandra , Bettinardi Alessandra , Puoti Massimo , Primi Daniele
Published: October 2006

The mechanism of T cell depletion during infection with the human immunodeficiency virus (HIV) is unclear. Examination of the repertoire of T cell receptor V (variable) regions in persons infected with HIV revealed the absence of a common set of V
β
regions, whereas V
α
usage was normal. The lack of these V
β
segments did not appear to correlate with opportunistic infections. The selective elimination of T cells that express a defined set of V
β
sequences may indicate the presence of an HIV-encoded superantigen, similar to those encoded by the long terminal repeat of the mouse mammary tumor virus.
Autoimmune Diseases: The Failure of Self Tolerance
Authors: Sinha Animesh A. , Lopez M. Theresa , McDevitt Hugh O.
Published: October 2006

The ability to discriminate between self and nonself antigens is vital to the functioning of the immune system as a specific defense against invading microorganisms. Failure of the immune system to "tolerate" self tissues can result in pathological autoimmune states leading to debilitating illness and sometimes death. The induction of autoimmunity involves genetic and environmental factors that have focused the attention of researchers on the trimolecular complex formed by major histocompatibility complex molecules, antigen, and T cell receptors. Detailed molecular characterization of these components points to potential strategies for disease intervention.
Adenine and Adenosine Are Toxic to Human Lymphoblast Mutants Defective in Purine Salvage Enzymes
Authors: Hershfield Michael S. , Snyder Floyd F. , Seegmiller J. Edwin
Published: October 2006

Mutants deficient in adenosine kinase or adenine phosphoribosyltransferase activities were selected from the WI-L2 line of human lymphoblasts. The adenosine kinase-deficient mutant was still as sensitive as its parent to growth inhibition caused by adenosine when adenosine deaminase was inhibited. Similarly, the adenine phosphoribosyltransferase mutant remained sensitive to growth inhibition caused by adenine. Thus, the toxicity of adenine and adenosine to human lymphoblasts is not mediated by nucleotides to which they may be converted.
Expression of Murine Sarcoma Virus Genes in Uninfected Rat Cells Subjected to Anaerobic Stress
Authors: Anderson Garth R. , Matovcik Lisa M.
Published: October 2006

Exposure of uninfected rat cells in tissue culture to anaerobic culture conditions induces transcription of RNA corresponding to the two principal constituents of rat-derived type-C sarcoma virus genomes: (i) those specific rat cell sequences present in the Kirsten and Harvey murine sarcoma virus genomes, and (ii) an endogenous type-C rat leukemia virus.
Regeneration of Douglas Fir Plantlets Through Tissue Culture
Authors: Cheng Tsai-Ying , Voqui Thanh H.
Published: October 2006

Douglas fir plantlets were produced in tissue culture under defined conditions from cotyledon explants obtained from 2- to 4-week-old seedlings. Tissue pieces were cultured on the surface of a fabric tissue support (100 percent polyester) saturated with liquid nutrient medium; this facilitated periodic changes of the medium to meet the requirements at successive developmental stages without transfer of cultured tissues. Plant growth regulators were needed to stimulate adventitious bud formation. Plantlets were regenerated by rooting excised shoots at 19°C on agar-solidified medium containing sucrose and the auxin naphthalene-2-acetic acid. After root initiation, plant growth regulators were removed; this resulted in stimulation of root elongation and the subsequent development of plantlets, which were then established in soil.
Asbestiform Chain Silicates: New Minerals and Structural Groups
Authors: Veblen David R. , Buseck Peter R. , Burnham Charles W.
Published: October 2006

The discovery and characterization of structurally ordered and disordered phases that are intermediate between amphiboles and micas have shown that the biopyriboles are a much more complex family of minerals than has previously been recognized. In addition to single-chain, double-chain, and sheet structures, there are also minerals with triple chains and with alternating double and triple chains. Many crystals exhibit disorder in the sequence of double and triple chains, and isolated chains that are wider than triple are common. This structural disorder helps to explain why asbestiform amphiboles are fibrous.

The new phases have now been found in several localities, and it is possible that similar phenomena in other minerals could also have been overlooked. In particular, there is no reason to suppose that analogous substances and structures with both single and double chains do not occur between the pyroxenes and the amphiboles. Since the pyroxenes are used extensively by geologists to assess rock histories and formation temperatures and pressures, it is essential that the extent of this type of disorder be evaluated. It is possible that what appears to be only an interesting mineralogical problem may prove to be a petrological nightmare.
Peptidoglycan in the Cell Wall of the Primary Intracellular Symbiote of the Pea Aphid
Authors: Houk Edward J. , Griffiths Gareth W. , Hadjokas Nicholas E. , Beck Stanley D.
Published: October 2006

Primary intracellular symbiotes of the pea aphid
, Acyrthosiphon pisum
(Harris), when fixed with potassium permanganate, revealed a distinctly staining area between the cytoplasmic membrane and the outer cell-wall envelope. This area is thought to be analogous to the peptidoglycan complex of the Eubacteriales. In addition, the diagnostic bacterial peptidoglycan amino compounds, muramic acid and diaminopimelic acid, were detected in a hydrochloric acid hydrolyzate of isolated symbiotes
.
Spontaneous Neurodegeneration in Transgenic Mice with Mutant Prion Protein
Authors: Hsiao Karen K. , Scott Michael , Foster Dallas , Groth Darlene F. , DeArmond Stephen J. , Prusiner Stanley B.
Published: October 2006

Transgenic mice were created to assess genetic linkage between Gerstmann-Sträussler-Scheinker syndrome and a leucine substitution at codon 102 of the human prion protein gene. Spontaneous neurologic disease with spongiform degeneration and gliosis similar to that in mouse scrapie developed at a mean age of 166 days in 35 mice expressing mouse prion protein with the leucine substitution. Thus, many of the clinical and pathological features of Gerstmann-Sträussler-Scheinker syndrome are reproduced in transgenic mice containing a prion protein with a single amino acid substitution, illustrating that a neurodegenerative process similar to a human disease can be genetically modeled in animals.
Translational Potentiation of Messenger RNA with Secondary Structure in
Xenopus
Authors: Fu Loning , Ye Ruiqiong , Browder Leon W. , Johnston Randal N.
Published: October 2006

Differential translation of messenger RNA (mRNA) with stable secondary structure in the 5′ untranslated leader may contribute to the dramatic changes in protein synthetic patterns that occur during oogenesis and early development. Plasmids that contained the bacterial gene chloramphenicol acetyltransferase and which encoded mRNA with (hpCAT) or without (CAT) a stable hairpin secondary structure in the 5′ noncoding region were transcribed in vitro, and the resulting mRNAs were injected into
Xenopus
oocytes, eggs, and early embryos. During early oogenesis, hpCAT mRNA was translated at less than 3 percent of the efficiency of CAT mRNA. The relative translational potential of hpCAT reached 100 percent in the newly fertilized egg and returned to approximately 3 percent after the midblastula transition.
Periodicity and Chaos in Coupled Nonlinear Oscillators
Authors: Gollub J. P. , Brunner T. O. , Danly B. G.
Published: October 2006

A system of coupled tunnel diode relaxation oscillators shows a variety of complex periodic states as the external voltage is varied. The existence of chaotic or nonperiodic states is more dependent on the nature of the coupling than on the number of degrees of freedom. A simple but accurate numerical model shows many of the phenomena observed experimentally.
Biosynthesis and Accumulation of Formic Acid in the Poison Gland of the Carpenter Ant
Camponotus pennsylvanicus
Authors: Hefetz Abraham , Blum Murray S.
Published: October 2006

Formic acid synthesis in the poison gland of
Camponotus pennsylvanicus
is closely related to the C-1 metabolism of the glandular cells. Serine, glycine, and histidine are potential C-1 donors to formic acid by several tetrahydrofolate intermediates. Formic acid is accumulated by its transfer to an insulated reservoir, so that the ant avoids the acid's cytotoxicity. This combination of biochemical and morphological features provides an autodefensive mechanism. Possible factors that regulate the biosynthesis of formic acid in the poison gland apparatus are discussed.
Low-Resolution Real-Space Envelopes: An Approach to the Ab Initio Macromolecular Phase Problem
Authors: Subbiah S,
Published: October 2006

An ab initio approach to the phase problem in macromolecular x-ray crystallography is described. A random gas of hard-sphere point scatterers is allowed to condense under the constraint of the solvent fraction and the restraint of the observed Fourier amplitude data. Two applications to real macromolecular examples are discussed. This method produces an approximate outline of the bulk solvent regions and thus yields a low-resolution picture of the unit cell that can be extended to higher resolutions in special cases, such as through the use of molecular replacement or of noncrystallographic symmetry-based phase extension.
Halohydrocarbon Synthesis by Bromoperoxidase
Authors: Theiler Richard , Cook J. Carter , Hager Lowell P. , Siuda Jerome F.
Published: October 2006

An enzyme extracted from marine red algae,
Bonnemaisonia hamifera
, is capable of incorporating bromine into a number of organic substrates in the
p
H range 5 to 8. At
p
H 7.3, incubation of partially purified preparations of bromoperoxidase with hydrogen peroxide, bromide ion, and 3-oxooctanoic acid leads to the formation of three volatile brominated hydrocarbons: dibromomethane, bromoform, and 1-pentyl bromide. The presence of significant quantities of halometabolites including volatile halohydrocarbons in marine organisms, ocean waters, and the upper atmosphere may result from peroxidase-catalyzed halogenation reactions.
The Early Days of Experimental Neutrino Physics
Authors: Reines Frederick
Published: October 2006

The neutrino hypothesis, put forward by Pauli to account for the apparent loss of energy and momentum in beta decay, was verified by a series of measurements at a nuclear reactor nearly 25 years ago. An account is given of the first observations of the interaction of neutrinos in a target remote from the fission process that produced them. These experiments completed the observations of the particles involved in beta decay and paved the way for use of the free neutrino to probe the nature of the weak interaction.
Venus: Density of Upper Atmosphere from Measurements of Drag on Pioneer Orbiter
Authors: Shapiro Irwin I. , Reasenberg Robert D. , Hintz Gerald R. , Jacobson Robert A. , Kirhofer William E. , Wong S. Kuen
Published: October 2006

Measurements of the changes in orbital period of the Pioneer Venus orbiter have yielded estimates of the density of the upper atmosphere of Venus at altitudes in the range from 150 to 200 kilometers. At the lower limit of this range, the density on the dayside of the terminator exhibits a temporal variation of amplitude near 4 × 10
–14
gram per cubic centimeter about a mean of approximately 1.4 × 10
–13
gram per cubic centimeter. The variation appears oscillatory, with a 4- to 5-day period, but barely one cycle was observed. The density on the nightside of the terminator, sampled in the same 150-kilometer altitude range, fluctuates about a smaller mean of approximately 4 × 10
–14
gram per cubic centimeter. The density between the altitudes of 150 and 200 kilometers, sampled only on the dayside of the terminator, imply a scale height of between 15 and 20 kilometers. The interpretation of this estimate is uncertain, however, in view of the measurements at the different altitudes having been made at different times and, hence, at different values of solar phase.
Structure of the Atmosphere of Venus up to 110 Kilometers: Preliminary Results from the Four Pioneer Venus Entry Probes
Authors: Seiff Alvin , Kirk Donn B. , Sommer Simon C. , Young Richard E. , Blanchard Robert C. , Juergens David W. , Lepetich Joseph E. , Intrieri Peter F. , Findlay John T. , Derr John S.
Published: October 2006

The four Pioneer Venus entry probes transmitted data of good quality on the structure of the atmosphere below the clouds. Contrast of the structure below an altitude of 50 kilometers at four widely separated locations was found to be no more than a few degrees Kelvin, with slightly warmer temperatures at 30° south latitude than at 5° or 60° north. The atmosphere was stably stratified above 15 or 20 kilometers, indicating that the near-adiabatic state is maintained by the general circulation. The profiles move from near-adiabatic toward radiative equilibrium at altitudes above 40 kilometers. There appears to be a region of vertical convection above the dense cloud deck, which lies at 47.5 to 49 kilometers and at temperature levels near 360 K. The atmosphere is nearly isothermal around 100 kilometers (175 to 180 K) and appears to exhibit a sizable temperature wave between 60 and 70 kilometers. This is where the 4-day wind is believed to occur. The temperature wave may be related to some of the wavelike phenomena seen in Mariner 10 ultraviolet photographs.
A Combined Irradiance-Transmittance Solar Spectrum and Its Application to Photovoltaic Efficiency Calculations
Authors: Ireland Philip J. , Wagner Sigurd , Kazmerskim Lawrence L. , Hulstrom Roland L.
Published: October 2006

SOLTRAN is a flexible computer model for the direct solar beam intensity spectrum at the earth's surface. It has been derived by combining the extraterrestrial solar spectrum with the atmospheric transmittance spectrum. Application of SOLTRAN to the calculation of the potential efficiency of photovoltaic cells demonstrates the effect of atmospheric absorption bands. These bands prevent unequivocal assignment of optimum energy gap values.
Production of Antibody to Tetanus Toxoid by Continuous Human Lymphoblastoid Cell Lines
Authors: Zurawski Vincent R. , Haber Edgar , Black Paul H.
Published: October 2006

Peripheral lymphocytes from human volunteers boosted with tetanus toxoid were cultured after in vitro infection with Epstein-Barr virus. Forty-four continuous lymphoblastoid lines were established which continued to secrete human gamma globulin; seven of these secreted antibody to tetanus toxoid. Subcultures derived from limiting dilution experiments continued to secrete the antibody. Some of these antibody-secreting cells have been in continuous culture for more than 6 months.
Opiate Peptide Modulation of Amino Acid Responses Suggests Novel Form of Neuronal Communication
Authors: Barker J. L. , Neale J. H. , Smith T. G. , Macdonald R. L.
Published: October 2006

Mouse spinal neurons grown in tissue culture were used to study the electrophysiological pharmacology of the opiate peptide leucine-enkephalin. Enkephalin depressed glutamate-evoked responses in a noncompetitive manner independent of any other effects on membrane properties. The results demonstrate a neuromodulatory action of opiate peptide functionally distinct from the conventional neurotransmitter class of operation.
Recent Advances in the Polymerase Chain Reaction
Authors: Erlich Henry A. , Gelfand David , Sninsky John J.
Published: October 2006

The polymerase chain reaction (PCR) has dramatically altered how molecular studies are conducted as well as what questions can be asked. In addition to simplifying molecular tasks typically carried out with the use of recombinant DNA technology, PCR has allowed a spectrum of advances ranging from the identification of novel genes and pathogens to the quantitation of characterized nucleotide sequences. PCR can provide insights into the intricacies of single cells as well as the evolution of species. Some recent developments in instrumentation, methodology, and applications of the PCR are presented in this review.
Submarine Seep of Carbon Dioxide in Norton Sound, Alaska
Authors: Kvenvolden Keith A. , Weliky Karen , Nelson Hans , Des Marais David J.
Published: October 2006

Earlier workers have described a submarine gas seep in Norton Sound having an unusual mixture of petroleum-like, low-molecular-weight hydrocarbons. Actually, only about 0.04 percent of the seeping gas is hydrocarbons and 98 percent is carbon dioxide. The isotopic compositions of carbon dioxide (δ
13
C
PDB
= –2.7 per mil) and methane (δ
13
C
PDB
= –36 per mil, where PDB is the Peedee belemnite standard) indicate that geothermal processes are active here.
Earthquakes near Parkfield, California: Comparing the 1934 and 1966 Sequences
Authors: Bakun W. H. , McEvilly T. V.
Published: October 2006

Moderate-sized earthquakes (Richter magnitude
M
L
5½) have occurred four times this century (1901, 1922, 1934, and 1966) on the San Andreas fault near Parkfield in central California. In many respects the June 1966 sequence was a remarkably detailed repetition of the June 1934 sequence, suggesting a recurring recognizable pattern of stress and fault zone behavior.
Imprinting Behavior: Pituitary-Adrenocortical Modulation of the Approach Response
Authors: Martin James T.
Published: October 2006

Plasma corticosterone concentrations in newly hatched ducklings exposed to an imprinting model are inversely related to the strength of approach behavior. Injections of corticosterone before imprinting reduces following, whereas α
1-10
-adrenocorticotropin or antiserum to corticosterone augments following behavior. The sensitive period for imprinting may be regulated by changes in the pituitary-adrenocortical axis.
U.S. Geological Survey Core Drilling on the Atlantic Shelf
Authors: Hathaway John C. , Poag C. Wylie , Valentine Page C. , Manheim Frank T. , Kohout Francis A. , Bothner Michael H. , Miller Robert E. , Schultz David M. , Sangrey Dwight A.
Published: October 2006

The first broad program of scientific shallow drilling on the U.S. Atlantic continental shelf has delineated rocks of Pleistocene to Late Cretaceous age, including phosphoritic Miocene strata, widespread Eocene carbonate deposits that serve as reflective seismic markers, and several regional unconformities. Two sites, off Maryland and New Jersey, showed light hydrocarbon gases having affinity to mature petroleum. Pore fluid studies showed that relatively fresh to brackish water occurs beneath much of the Atlantic continental shelf, whereas increases in salinity off Georgia and beneath the Florida-Hatteras slope suggest buried evaporitic strata. The sediment cores showed engineering properties that range from good foundation strength to a potential for severe loss of strength through interaction between sediments and man-made structures.
Radio Science with Voyager at Jupiter: Initial Voyager 2 Results and a Voyager 1 Measure of the Io Torus
Authors: Eshleman V. R. , Tyler G. L. , Wood G. E. , Lindal G. F. , Anderson J. D. , Levy G. S. , Croft T. A.
Published: October 2006

Voyager 2 radio signals were observed essentially continuously during a grazing occultation of the spacecraft by the southern limb of Jupiter. Intensity data show a classic atmospheric occultation profile and the effects of turbulence and ionospheric focusing and defocusing. No reliable profile of the neutral atmosphere has yet been obtained, primarily because of a combination of large trajectory uncertainties and error multiplication effects associated with the grazing geometry of the Voyager 2 occultation. Analysis of the dispersive ionospheric refraction data yields preliminary profiles for the topside ionosphere at 66.7°S (entry in the evening) and 50.1°S (exit in the morning) that are reversed with respect to corresponding Voyager 1 profiles in terms of plasma concentration at a fixed altitude. Plasma scale heights and temperatures of 880 kilometers, 1200 K and 1040 kilometers, 1600 K were obtained for morning and evening conditions, respectively. Preliminary reduction of the pre-encounter occultation of Voyager 1 by the Io torus yields an average plasma density of about 1000 electrons per cubic centimeter.
Genetic Component of Bee Odor in Kin Recognition
Authors: Greenberg Les
Published: October 2006

The primitively social sweat bee,
Lasioglossum zephyrum
, blocks the entry into its nest of most conspecifics from other colonies. Laboratory inbreeding of these bees produced lines which showed a positive linear relationship between the coefficient of relationship of bees tested and how often they permitted non-nestmates to pass them. The most probable mechanism is a genetically determined odor coupled with a learned component by which guard bees discriminate between odors of close kin and other bees.
Discharge of the Nile River: A Barometer of Short-Period Climate Variation
Authors: Riehl Herbert , Meitín José
Published: October 2006

Eight events of climate variation with durations of the order of 100 years have been found in the history of annual Nile River discharge dating from the year 622. They cease during the "little climatic optimum" in the North Atlantic and then reappear and intensify; this behavior suggests that control is from the belt of the polar westerlies.
The Essentiality of Vitamin D Metabolites for Embryonic Chick Development
Authors: Sunde M. L. , Turk C. M. , DeLuca H. F.
Published: October 2006

Laying hens maintained on 1,25-dihydroxyvitamin D
3
as their sole source of vitamin D produce eggs which appear normal but which produce embryos having a defective upper mandible and which die at 18 to 19 days of embryonic life. Hens maintained on 25-hydroxyvitamin D
3
, on the other hand, produce normal embryos. Hens fed a vitamin D deficient diet produce eggs which develop the same embryonic defect. Injection of the affected eggs from the 1,25-dihydroxyvitamin D
3
fed hens with vitamin D
3
, 25-hydroxyvitamin D
3
, or 1,25-dihydroxyvitamin D
3
greatly increases the percentage of normal embryos. It therefore appears that 1,25-dihydroxyvitamin D
3
is not transferred from hen to egg in sufficient amounts to support embryonic development and that vitamin D or its metabolites, or both, are necessary for normal chick embryo development.
Feedback Control of Juvenile Hormone Synthesis in Cockroaches: Possible Role for Ecdysterone
Authors: Stay Barbara , Friedel Thomas , Tobe Stephen S. , Mundall Eric C.
Published: October 2006

Inactive female corpora allata implanted into adult males become active and continue to synthesize juvenile hormone at high rates. However, when an ovary is implanted together with the corpora allata, rates of juvenile hormone synthesis decline as the oocytes complete maturation. Injections of ecdysterone mimic the effect of an implanted ovary.
How Electric Fields Modify Alkane Solubility in Lipid Bilayers
Authors: White Stephen H.
Published: October 2006

The planar lipid bilayer membrane is assumed to be in osmotic equilibrium with the surrounding Plateau-Gibbs border (annulus) and entrapped microlenses. An electric field applied across the membrane raises the chemical potential of the alkane in the bilayer, causing it to shift from the bilayer to the annulus and microlenses. This shift results in a decrease in thickness.
Enhancement of Superconductivity through Lattice Softening
Authors: Matthias B. T. , Stewart G. R. , Giorgi A. L. , Smith J. L. , Fisk Z. , Barz H.
Published: October 2006

The superconducting transition temperature of an iridium-yttrium eutectic is enhanced extraordinarily through lattice softening. This is shown by a drastically reduced Debye temperature.
β-Adrenergic Receptors in Aged Rat Brain: Reduced Number and Capacity of Pineal Gland to Develop Supersensitivity
Authors: Greenberg Louise H. , Weiss Benjamin
Published: October 2006

The density but not the affinity of β-adrenergic receptors declined significantly with age in rat pineal gland, corpus striatum, and cerebellum, as determined by the binding of tritiated dihydroalprenolol. Exposing rats to light for 12 hours increased the binding of this radioligand in 3-month-old but not in 24-month-old rats. The reduced responsiveness to catecholamines seen in aging may be due to a decrease in the number of β-adrenergic receptors which, in turn, may be caused by an impaired capacity of receptors in aged animals to adapt to changes in adrenergic neuronal input.
Rise and Fall of Cyclic AMP Required for Onset of Lymphocyte DNA Synthesis
Authors: Wang Tingchung , Sheppard J. R. , Foker John E.
Published: October 2006

The adenosine 3′,5′-monophosphate (cyclic AMP) levels of mouse lymphocytes rose and fell sharply 10 hours after stimulation with concanavalin A. Treatment of the cells with indomethacin reversibly prevented the increase in cyclic AMP and the subsequent onset of DNA synthesis. When the heightened cyclic AMP before S phase was maintained by either inhibiting phosphodiesterase or by adding the 8-bromo derivative of cyclic AMP, DNA synthesis was also blocked. Both the increase and decrease in cyclic AMP appear to be required for progression of lymphocytes into the S phase of growth.
Prostaglandin Restoration of the Interferon Response of Hyporeactive Animals
Authors: Stringfellow Dale A.
Published: October 2006

Virus-infected animals and those bearing various types of malignancies progressively lose their ability to respond to interferon inducers. The interferon response of virus-infected animals could be restored to normal levels when inducers were administered with certain prostaglandins. This suggests that prostaglandins may enhance the therapeutic efficacy of interferon inducers as antiviral and antineoplastic agents.
Research and Development, Productivity, and Inflation
Authors: Mansfield Edwin
Published: October 2006

R & D, through its effects on the rate of productivity increase, can significantly restrain the rate of inflation in the medium and long run. High rates of inflation damage the workings of the price system and impair the efficiency of practically all economic activities, including R & D. Findings suggest that the percentage increase between 1969 and 1979, in total real R & D expenditures, has been exaggerated due to the inadequacy of the gross national product deflator as applied to R & D.
Oxygen Consumption in Pelagic Marine Sediments
Authors: Murray James W. , Grundmanis Varis
Published: October 2006

Measurements in the interstitial waters of pelagic red clay and carbonate ooze sediments in the central equatorial Pacific show that the dissolved oxygen content decreases with depth and levels off at nonzero values. The supply of reactive organic carbon introduced by bioturbation limits oxygen consumption at depth in the sediment. These gradients should produce diffusive fluxes across the sediment-water interface that average about 8.8 × 10
–14
mole per square centimeter per second or 0.08 milliliter per square meter per hour.
Nimbus-7 Coastal Zone Color Scanner: System Description and Initial Imagery
Authors: Hovis W. A. , Clark D. K. , Anderson F. , Austin R. W. , Wilson W. H. , Baker E. T. , Ball D. , Gordon H. R. , Mueller J. L. , El-Sayed S. Z. , Sturm B. , Wrigley R. C. , Yentsch C. S.
Published: October 2006

The Coastal Zone Color Scanner (CZCS) on Nimbus-7, launched in October 1978, is the only sensor in orbit that is specifically designed to study living marine resources. The initial imagery confirms that CZCS data can be processed to a level that reveals subtle variations in the concentration of phytoplankton pigments. This development has potential applications for the study of large-scale patchiness in phytoplankton distributions, the evolution of spring blooms, water mass boundaries, and mesoscale circulation patterns.
MalePhoturisFireflies Mimic Sexual Signals of Their Females' Prey
Authors: Lloyd James E.
Published: October 2006

Photurismales emit flashed signals matching those of unrelated sympatric forms (PhotinusandPyractomenaspecies). Some have only one flash pattern matching that of another species, others mimic at least two species, as well as emitting "their own" species-specific pattern. They tend to restrict the mimicking signals, but not their own, to the habitats, seasons, and daily periods of the mimicked species. SincePhoturisfemales prey on males of other firefly species by mimicking their females' flashes, thePhoturismales may be using their mimicry to locate and seduce their own hunting females. This mimicry is without known parallel in other animal communicative systems. It explains why the genusPhoturishas been a frustrating mystery to taxonomists, who have long used flash patterns to distinguish sibling species in other genera.
The Works of Living Social Insects as Pseudofossils and the Age of the Oldest Known Metazoa
Authors: Cloud Preston , Gustafson L. B. , Watson J. A. L.
Published: October 2006

Living organisms are known to create structures in ancient rocks that are indigenous but not primary and that have been mistaken for fossils. Examination of burrows recently reported as fossils from 10
9
-year-old sedimentary rocks indicates that they are not the same age as the rocks but were probably made by termites working down after water. The burrows are partially filled with material from a modern lateritic surface from which they descend into steeply dipping, decomposed siltstones of the Zambian Copperbelt. In fact, no authentic record of Metazoa that are demonstrably coeval with rocks older than 680 million years is known.
Deforestation and Increased Flooding of the Upper Amazon
Authors: Gentry A. H. , Lopez-Parodi J.
Published: October 2006

The height of the annual flood crest of the Amazon at Iquitos has increased markedly in the last decade. During this same period, there has been greatly increased deforestation in the upper parts of the Amazon watershed in Peru and Ecuador, but no significant changes in regional patterns of precipitation. The change in Amazonian water balance during the last decade appears to be the result of increased runoff due to deforestation. If so, the long-predicted regional climatic and hydrological changes that would be the expected result of Amazonian deforestation may already be beginning.
Atmospheric Trace Gases in Antarctica
Authors: Rasmussen R. A. , Khalil M. A. K. , Dalluge R. W.
Published: October 2006

Trace gases have been measured, by electron-capture gas chromatography and gas chromatography-mass spectrometry techniques, at the South Pole (SP) in Antarctica and in the U.S. Pacific Northwest (PNW) (∼45°N) during January of each year from 1975 to 1980. These measurements show that the concentrations of CCl
3
F, CCl
2
F
2
, and CH
3
CCl
3
have increased exponentially at substantial rates. The concentration of CCl
3
F increased at 12 percent per year at the SP and at 8 percent per year in the PNW; CCl
2
F
2
increased at about 9 percent per year at both locations, and CH
3
CCl
3
increased at 17 percent per year at the SP and 11.6 percent per year at the PNW site. There is some evidence that CCl
4
(∼3 percent per year) and N
2
O (0.1 to 0.5 percent per year) may also have increased. Concentrations of nine other trace gases of importance in atmospheric chemistry are also being measured at these two locations. Results of the measurements of CHClF
2
(F-22), C
2
Cl
3
F
3
(F-113), SF
6
, C
2
-hydrocarbons, and CH
3
Cl are reported here.
Competition in Desert Rodents: An Experiment with Semipermeable Exclosures
Authors: Munger James C. , Brown James H.
Published: October 2006

Larger species of seed-eating desert rodents were excluded from experimental plots while smaller, potentially competing species were allowed to enter. Density of small granivores on these plots increased to nearly 3.5 times that on control plots but only after 8 months. These results indicate that interspecific competition affects the abundance of desert rodents; they also support indirect evidence that competition for seeds influences the organization of desert rodent communities.
Characterization of Aerosols from Eruptions of Mount St. Helens
Authors: Chuan R. L. , Woods D. C. , McCormick M. P.
Published: October 2006

Measurements of mass concentration and size distribution of aerosols from eruptions of Mount St. Helens as well as morphological and elemental analyses were obtained between 7 April and 7 August 1980. In situ measurements were made in early phreatic and later, minor phreatomagmatic eruption clouds near the vent of the volcano and in plumes injected into the stratosphere from the major eruptions of 18 and 25 May. The phreatic aerosol was characterized by an essentially monomodal size distribution dominated by silicate particles larger than 10 micrometers in diameter. The phreatomagmatic eruption cloud was multimodal; the large size mode consisted of silicate particles and the small size modes were made up of mixtures of sulfuric acid and silicate particles. The stratospheric aerosol from the main eruption exhibited a characteristic narrow single mode with particles less than 1 micrometer in diameter and nearly all of the mass made up of sulfuric acid droplets.
Size Distributions and Mineralogy of Ash Particles in the Stratosphere from Eruptions of Mount St. Helens
Authors: Farlow Neil H. , Oberbeck Verne R. , Snetsinger Kenneth G. , Ferry Guy V. , Polkowski George , Hayes Dennis M.
Published: October 2006

Samples from the stratosphere obtained by U-2 aircraft after the first three major eruptions of Mount St. Helens contained large globules of liquid acid and ash. Because of their large size, these globules had disappeared from the lower stratosphere by late June 1980, leaving behind only smaller acid droplets. Particle-size distributions and mineralogy of the stratospheric ash grains demonstrate inhomogeneity in the eruption clouds.
Solution Structure of the Glucocorticoid Receptor DNA-Binding Domain
Authors: Härd Torleif , Kellenbach Edwin , Boelens Rolf , Maler Bonnie A. , Dahlman Karin , Freedman Leonard P. , Carlstedt-Duke Jan , Yamamoto Keith R. , Gustafsson Jan-Åke , Kaptein Robert
Published: October 2006

The three-dimensional structure of the DNA-binding domain (DBD) of the glucocorticoid receptor has been determined by nuclear magnetic resonance spectroscopy and distance geometry. The structure of a 71-residue protein fragment containing two "zinc finger" domains is based on a large set of proton-proton distances derived from nuclear Overhauser enhancement spectra, hydrogen bonds in previously identified secondary structure elements, and coordination of two zinc atoms by conserved cysteine residues. The DBD is found to consist of a globular body from which the finger regions extend. A model of the dimeric complex between the DBD and the glucocorticoid response element is proposed. The model is consistent with previous results indicating that specific amino acid residues of the DBD are involved in protein-DNA and protein-protein interactions.
Protection Against Mucoid
Pseudomonas aeruginosa
in Rodent Models of Endobronchial Infections
Authors: Pier Gerald B. , Small Gloria J. , Warren Henry B.
Published: October 2006

Chronic endobronchial infection with mucoid
Pseudomonas aeruginosa
accounts for much of the morbidity and mortality in patients with cystic fibrosis (CF). Reduced morbidity is observed when infection is absent. Clinical investigations have implicated opsonizing antibody specific for the mucoid exopolysaccharide (MEP) surrounding these bacteria as a potential immunologic protective mechanism, whereas nonopsonizing antibody to MEP is not protective. Mice and rats immunized with doses of MEP that elicited opsonizing antibody had reduced levels of infection compared with nonimmune controls after intratracheal challenge with mucoid
P. aeruginosa
enmeshed in agar beads. Doses of MEP that elicited nonopsonizing antibody were not protective. Parallel experiments in which passive transfer of polyclonal and monoclonal opsonizing and nonopsonizing antibody were used yielded similar results. These data indicate that MEP-specific opsonizing antibody can protect against chronic
P. aeruginosa
infection in this model of disease.
Growth of Bivalves at Deep-Sea Hydrothermal Vents Along the Galápagos Rift
Authors: Rhoads Donald C. , Lutz Richard A. , Revelas Eugene C. , Cerrato Robert M.
Published: October 2006

Direct measurements of shell growth of an unclassified mussel from active hydrothermal vents along the Galápagos Rift reveal growth rates of approximately 1 centimeter per year for mature specimens. The largest mussel collected (with shell length of 18.4 centimeters) was estimated to be 19 ± 7 years old at the time of sampling. Recorded growth rates are among the highest documented for deep-sea species.
Paleognathous Carinate Birds from the Early Tertiary of North America
Authors: Houde Peter , Olson Storrs L.
Published: October 2006

Fossils newly discovered in the Paleocene and early Eocene of western North America document some of the oldest birds known from nearly complete skeletons. These were medium-sized carinates with powers of sustained flight but which had a paleognathous palate like that of the flightless ostrich-like birds and the tinamous. The fossils provide additional evidence that the paleognathous palate is probably primitive and therefore should not be cited as a derived character state to define the ostrich-like birds as a monophyletic group.
Transmembrane Helical Interactions and the Assembly of the T Cell Receptor Complex
Authors: Manolios Nicholas , Bonifacino Juan S. , Klausner Richard D.
Published: October 2006

Studies of the subunit interactions of the multicomponent T cell antigen receptor (TCR) revealed that specific pairs of chains have the ability to assemble after transfection into fibroblasts. For one such pair, TCR-α and CD3-δ, their ability to assemble was encoded by their transmembrane domains. The specificity of this interaction suggests that well-defined helical interactions in the membrane can explain the assembly of some multichain membrane complexes.