bluuebunny/crossref_metadata_2025 huggingface dataset:
Laboratory Simulation of Thermal Convection in Rotating Planets and Stars
Authors: Busse F. H. , Carrigan C. R.
Published: October 2006

Because of dynamical constraints in a rotating system, the component of gravity perpendicular to the axis of rotation is the dominant driving force of convection in liquid planetary cores and in stars. Except for the sign, the centrifugal force closely resembles the perpendicular component of gravity. Convection processes in stars and planets can therefore be modeled in laboratory experiments by using the centrifugal force with a reversed temperature gradient.
Deep-Sea Carbonates: Dissolution and Mass Wasting on Ontong-Java Plateau
Authors: Berger W. H. , Johnson T. C.
Published: October 2006

Seismic reflection profiles and the structure of sediments in box cores from Ontong-Java Plateau indicate large-scale land sliding and sediment flow processes, respectively. The topographic morphology of sliding and slumping is depth-dependent, suggesting control by dissolution processes.
Autocrine or Paracrine Inflammatory Actions of Corticotropin-Releasing Hormone in Vivo
Authors: Karalis Katia , Sano Hajime , Redwine Jeffrey , Listwak Sam , Wilder Ronald L. , Chrousos George P.
Published: October 2006

Corticotropin-releasing hormone (CRH) functions as a regulator of the hypothalamic-pituitary-adrenal axis and coordinator of the stress response. CRH receptors exist in peripheral sites of the immune system, and CRH promotes several immune functions in vitro. The effect of systemic immunoneutralization of CRH was tested in an experimental model of chemically induced aseptic inflammation in rats. Intraperitoneal administration of rabbit antiserum to CRH caused suppression of both inflammatory exudate volume and cell concentration by approximately 50 to 60 percent. CRH was detected in the inflamed area but not in the systemic circulation. Immunoreactive CRH is therefore produced in peripheral inflammatory sites where, in contrast to its systemic indirect immunosuppressive effects, it acts as an autocrine or paracrine inflammatory cytokine.
Reversible Inhibition of Tomato Fruit Senescence by Antisense RNA
Authors: Oeller Paul W. , Lu Min-Wong , Taylor Loverine P. , Pike Deborah A. , Theologis Anasios A
Published: October 2006

Ethylene controls fruit ripening. Expression of antisense RNA to the rate-limiting enzyme in the biosynthetic pathway of ethylene, 1-aminocyclopropane-1-carboxylate synthase, inhibits fruit ripening in tomato plants. Administration of exogenous ethylene or propylene reverses the inhibitory effect. This result demonstrates that ethylene is the trigger and not the by-product of ripening and raises the prospect that the life-span of plant tissues can be extended, thereby preventing spoilage.
Hooked Trichomes: A Physical Plant Barrier to a Major Agricultural Pest
Authors: Pillemer Eric A. , Tingey Ward M.
Published: October 2006

Hooked epidermal appendages (trichomes) on leaves of field bean cultivars effectively capture nymph and adult leafhoppers. Frequency of capture and capture mortality are highly correlated with trichome density. Hooked trichomes inserted at angles less than 30° are ineffective in capture.
New Radar Image of Venus
Authors: Campbell D. B. , Dyce R. B. , Pettengill G. H.
Published: October 2006

A new radar image of Venus covering the latitude range 46° to 75° and the approximate longitude range 290° to 10° is shown. The resolution is approximately 20 kilometers.
Hormone-Induced Cyclic Guanosine Monophosphate Secretion from Guinea Pig Pancreatic Lobules
Authors: Kapoor C. L. , Krishna G,
Published: October 2006

Carbamylcholine (30 μ
M
) increased the concentration of guanosine 3′,5′-monophosphate (cyclic GMP) in guinea pig pancreatic lobules about eight- to tenfold over the basal concentration in 30 seconds with a concomitant increase in the rate of amylase secretion. The concentration of cyclic GMP rapidly declined to a plateau value of about 16 percent of the peak level in 10 minutes. Cellular cyclic GMP decreased, mostly because the nucleotide was secreted into the medium; cellular adenosine 3′,5′-monophosphate (cyclic AMP), however, did not change, nor was this nucleotide secreted into the medium. An immunocytochemical technique showed that cyclic GMP was distributed in the apical plasmalemma membrane and lumen of the pancreas. Carbamylcholine increased the cyclic GMP fluorescence in the apical plasmalemma membrane within 30 seconds, and in zymogen granules and the plasma membrane in the apical part of acinar cells in 10 minutes. The islets of Langerhans did not show any change in cyclic GMP. Fluorescence of cyclic AMP in pancreatic lobules was not altered by carbamylcholine and was localized along the apical portion of plasmalemma and cytoplasm. Cyclic GMP may thus participate either in the process of exocytosis or in the activation of enzymes secreted from the pancreas.
Increased Transport of Antarctic Bottom Water in the Vema Channel During the Last Ice Age
Authors: Ledbetter Michael T. , Johnson David A.
Published: October 2006

Particle size analyses of surface sediments in the Vema Channel reveal a spatial variation related to the present hydrography. Similar analyses of sediment deposited during the last ice age (18,000 years before the present) indicate a maximum shallowing of the upper limit of Antarctic Bottom Water (AABW) of about 100 meters, coupled with an increase in velocity, which resulted in an increase in AABW transport.
Inorganic Analyses of Martian Surface Samples at the Viking Landing Sites
Authors: Clark Benton C. , Baird A. K. , Rose Harry J. , Toulmin Priestley , Keil Klaus , Castro Angelo J. , Kelliher Warren C. , Rowe Catherine D. , Evans Peter H.
Published: October 2006

Elemental analyses of fines in the Martian regolith at two widely separated landing sites, Chryse Planitia and Utopia Planitia, produced remarkably similar results. At both sites, the uppermost regolith contains abundant Si and Fe, with significant concentrations of Mg, Al, S, Ca, and Ti. The S concentration is one to two orders of magnitude higher, and K (<0.25 percent by weight) is at least 5 times lower than the average for the earth's crust. The trace elements Sr, Y, and possibly Zr, have been detected at concentrations near or below 100 parts per million. Pebblesized fragments sampled at Chryse contain more S than the bulk fines, and are thought to be pieces of a sulfate-cemented duricrust.
Viking Labeled Release Biology Experiment: Interim Results
Authors: Levin Gilbert V. , Straat Patricia Ann
Published: October 2006

This report summarizes all results of the labeled release life detection experiment conducted on Mars prior to conjunction. Tests at both landing sites provide remarkably similar evolution of radioactive gas upon addition of a radioactive nutrient to the Mars sample. The "active" agent in the Mars sample is stable to 18°C, but is substantially inactivated by heat treatment for 3 hours at 50°C and completely inactivated at 160°C, as would be anticipated if the active response were caused by microorganisms. Results from test and heat-sterilized control Mars samples are compared to those obtained from terrestrial soils and from a lunar sample. Possible nonbiological explanations of the Mars data are reviewed along with plans for resolution of the Mars data. Although such explanations of the labeled release data depend on ultraviolet irradiation, the labeled release response does not appear to depend on recent direct ultraviolet activation of surface material. Available facts do not yet permit a conclusion regarding the existence of life on Mars. Plans for conclusion of the experiment are discussed.
Modulation of Macrophage Tumoricidal Capability by Components of Normal Serum: A Central Role for Lipid
Authors: Chapman Harold A. , Hibbs John B.
Published: October 2006

The tumoricidal capabilities of macrophages can be reversibly inhibited by a lipoprotein of high molecular weight, and the inhibition appears to be reproduced by enrichment of macrophage plasma membranes with cholesterol. A second serum component of lower molecular weight enhances macrophage cytotoxicity. The presence of these components in normal serums suggests a physiological role for such factors in the regulation of macrophage function.
Optical Coherence Tomography
Authors: Huang David , Swanson Eric A. , Lin Charles P. , Schuman Joel S. , Stinson William G. , Chang Warren , Hee Michael R. , Flotte Thomas , Gregory Kenton , Puliafito Carmen A. , Fujimoto James G.
Published: October 2006

A technique called optical coherence tomography (OCT) has been developed for noninvasive cross-sectional imaging in biological systems. OCT uses low-coherence interferometry to produce a two-dimensional image of optical scattering from internal tissue microstructures in a way that is analogous to ultrasonic pulse-echo imaging. OCT has longitudinal and lateral spatial resolutions of a few micrometers and can detect reflected signals as small as ∼10
-10
of the incident optical power. Tomographic imaging is demonstrated in vitro in the peripapillary area of the retina and in the coronary artery, two clinically relevant examples that are representative of transparent and turbid media, respectively.
Sequence-Selective Recognition of DNA by Strand Displacement with a Thymine-Substituted Polyamide
Authors: Nielsen Peter E. , Egholm Michael , Berg Rolf H. , Buchardt Ole
Published: October 2006

A polyamide nucleic acid (PNA) was designed by detaching the deoxyribose phosphate backbone of DNA in a computer model and replacing it with an achiral polyamide backbone. On the basis of this model, oligomers consisting of thymine-linked aminoethylglycyl units were prepared. These oligomers recognize their complementary target in double-stranded DNA by strand displacement. The displacement is made possible by the extraordinarily high stability of the PNA-DNA hybrids. The results show that the backbone of DNA can be replaced by a polyamide, with the resulting oligomer retaining base-specific hybridization.
β-Endorphin and Adrenocorticotropin Are Selected Concomitantly by the Pituitary Gland
Authors: Guillemin Roger , Vargo Therese , Rossier Jean , Minick Scott , Ling Nicholas , Rivier Catherine , Vale Wylie , Bloom Floyd
Published: October 2006

The opiate-like peptide β-endorphin and adrenocorticotropin are concomitantly secreted in increased amounts by the adenohypophysis in response to acute stress or long-term adrenalectomy as well as in vitro in response to purified corticotropin releasing factor and other secretagogues. Conversely, administration of the synthetic glucocorticoid dexamethasone inhibits the secretion of both adrenocorticotropin and β-endorphin. Thus, both hormones possess common and identical regulatory mechanisms and there may be a functional role for circulating β-endorphin.
Synchronized Ultradian Cortisol Rhythms in Monkeys: Persistence During Corticotropin Infusion
Authors: Holaday John W. , Martinez Hugo M. , Natelson Benjamin H.
Published: October 2006

A highly synchronized ultradian cortisol rhythm with a predominant periodicity of 85 to 90 minutes was observed in eight isolated monkeys; this rhythm may be harmonically related to the circadian rhythm. The persistence of this synchronized rhythm during supramaximal infusions of adrenocorticotropin not only suggests that feedback is not causative but also challenges the classic concept that bursts of cortisol secretion are dependent upon an immediately preceding release of adrenocorticotropin.
International Sun-Earth Explorer: A Three-Spacecraft Program
Authors: Ogilvie K. W. , von Rosenvinge T. , Durney A. C.
Published: October 2006

The International Sun-Earth Explorer is a three-spacecraft program of the National Aeronautics and Space Administration and the European Space Agency aimed at securing a more quantitative knowledge of the structure and stability of the magnetosphere. One spacecraft (ISEE-C) makes observations in the solar wind upstream of the earth, while the other two (ISEE-A and ISEE-B), in the same highly eccentric orbit but separated by a relatively small variable distance, observe inside the magnetosphere. This international program is concurrent with the International Magnetospheric Study, to which ISEE-A and ISEE-C form a large U.S. contribution. The scientific aims and technological methods are discussed.
Sedimentary Polycyclic Aromatic Hydrocarbons: The Historical Record
Authors: Hites Ronald A. , Laflamme Robert E. , Farrington John W.
Published: October 2006

Polycyclic aromatic hydrocarbons in three sections of a dated sediment core from Buzzards Bay, Massachusetts, have been analyzed by gas chromatographic spectrometry. This historical information suggests that sedimentary polycyclic aromatic hydrocarbons, at least at this location, result primarily from the anthropogenic combustion of fossil fuels.
Structure and Properties of Metallic Glasses
Authors: Chaudhari P. , Turnbull D.
Published: October 2006

Recent experience has shown that certain metal alloys can be put into glass form by rapid melt-quenching or by various condensation processes. Models for the nature and structure of these glasses are surveyed and shown to be quite parallel to those already developed for the more common nonmetallic glasses. The rather unique magnetic, superconducting, and mechanical properties and the technical potential of metallic glasses are also discussed.
Phytolith Analysis of Archeological Soils: Evidence for Maize Cultivation in Formative Ecuador
Authors: Pearsall Deborah M.
Published: October 2006

Soil samples from the archeological sites of Real Alto and OGCh-20, Santa Elena Peninsula, Ecuador, show the presence of cross-shaped silica bodies identifiable as maize (
Zea mays
L.) phytoliths by size comparison with known wild grass and maize phytoliths. These results support arguments for the cultivation of maize at 2450 B.C. in coastal Ecuador.
Population Aging Policies in East Asia and the United States
Authors: Martin Linda G.
Published: October 2006

As a result of successful efforts to reduce fertility and mortality, East Asian populations are beginning to age, in some cases rapidly. Policies in response to population aging range from attempts in Singapore to reverse it by encouraging more births to efforts in Japan to accommodate it by increasing employment opportunities for older workers. The population of the United States, which had a longer postwar baby boom, is aging more slowly than these two countries and may be able to learn from the East Asian experience with aging policies.
Light-Directed, Spatially Addressable Parallel Chemical Synthesis
Authors: Fodor Stephen P. A. , Read J. Leighton , Pirrung Michael C. , Stryer Lubert , Lu Amy Tsai , Solas Dennis
Published: October 2006

Solid-phase chemistry, photolabile protecting groups, and photolithography have been combined to achieve light-directed, spatially addressable parallel chemical synthesis to yield a highly diverse set of chemical products. Binary masking, one of many possible combinatorial synthesis strategies, yields 2

n

compounds in
n
chemical steps. An array of 1024 peptides was synthesized in ten steps, and its interaction with a monoclonal antibody was assayed by epifluorescence microscopy. High-density arrays formed by light-directed synthesis are potentially rich sources of chemical diversity for discovering new ligands that bind to biological receptors and for elucidating principles governing molecular interactions. The generality of this approach is illustrated by the light-directed synthesis of a dinucleotide. Spatially directed synthesis of complex compounds could also be used for microfabrication of devices.
Cyclic Nucleotides Injected Intracellularly into Rat Superior Cervical Ganglion Cells
Authors: Gallagher Joel P. , Shinnick-Gallagher Patricia
Published: October 2006

Intracellular iontophoresis of either adenosine 3′,5′-monophosphate or guanosine 3′,5′-monophosphate produces a membrane depolarization and an increased membrane conductance in sympathetic ganglion cells of the rat superior cervical ganglion. Since adenosine 3′,5′-monophosphate did not cause a membrane hyperpolarization, it is difficult to assign it a second messenger role in the mediation of the slow inhibitory postsynaptic potential. However, these results do not rule out the possibility that the cyclic nucleotides, at the intracellular concentrations attained in these experiments, participate in cellular processes that contribute to conductance changes which result in depolarization of the ganglion cell membrane.
North American Glacial History Extended to 75,000 Years Ago
Authors: Stuiver Minze , Heusser Calvin J. , Yang In Che
Published: October 2006

By concentrating carbon-14 through thermal diffusion, it is possible to extend the range of carbon-14 dating to 75,000 years ago. Samples with very low contamination levels have been encountered, and a reliable chronology appears possible. A Pacific Northwest climatic curve has been derived from palynological studies. The Pacific Northwest curve and the Great Lakes glacial history are age-calibrated by radiocarbon dating. The climatic patterns in the Pacific Northwest and Northwest Europe are similar in the early part of the last glaciation, with interstades near 60,000, 65,000, and 70,000 years ago. An age of 74,700 years for the St. Pierre interstade indicates a possible correlation with the previous interglacial.
Behavior and the Crustacean Molt Cycle: Changes in Aggression of
Homarus americanus
Authors: Tamm George R. , Cobb J. Stanley
Published: October 2006

The phase of the molt cycle affects dominance status and the performance of agonistic acts in individual juvenile lobsters (
Homarus americanus
). Lobsters in the midphase of proecdysis are more aggressive than those in intermolt; the latter are more aggressive than lobsters in early or late proecdysis and those in postecdysis.
Hail Suppression and Society
Authors: Changnon Stanley A. , Farhar Barbara C. , Swanson Earl R.
Published: October 2006

An interdisciplinary assessment of hail suppression in the past, present, and future has shown it to be currently scientifically uncertain but a potentially beneficial future technology. An established suppression technology would be widely adopted in the Great Plains, providing benefits to agriculture and secondarily to the American consumer. Development of a reliable technology will require a sizable long-term federal commitment to atmospheric and social research. Subcritical funding would be a mistake. Orderly future usage of hail suppression, with its scientific complexities and regional character, will necessitate development of governmental regulations, evaluation procedures, interstate arrangements, and means for compensating those who lose from modification.
Namoratunga: The First Archeoastronomical Evidence in Sub-Saharan Africa
Authors: Lynch B. M. , Robbins L. H.
Published: October 2006

Namoratunga, a megalithic site in northwestern Kenya, has an alignment of 19 basalt pillars that are nonrandomly oriented toward certain stars and constellations. The same stars and constellations are used by modern eastern Cushitic peoples to calculate an accurate calendar. The fact that Namoratunga dates to about 300 B.C. suggests that a prehistoric calendar based on detailed astronomical knowledge was in use in eastern Africa.
Repression of HIV-1 Transcription by a Cellular Protein
Authors: Kato Hiroyuki , Horikoshi Masami , Roeder Robert G.
Published: October 2006

A cellular DNA binding protein, LBP-1, sequentially interacts in a concentration-dependent manner with two sites that surround the transcriptional initiation site of the human immunodeficiency virus type 1 (HIV-1) promoter. Although sequences in the downstream site (site I) were found to enhance transcription, purified LBP-1 specifically repressed transcription in vitro by binding to the upstream site (site II), which overlaps the TATA element. The binding of human TATA binding factor (TFIID) to the promoter before LBP-1 blocked repression, suggesting that repression resulted from an inhibition of TFIID binding to the TATA element. Furthermore, mutations that eliminated binding to site II both prevented repression in vitro and increased HIV-1 transcription in stably transformed cells. These findings suggest that a cellular factor regulates HIV-1 transcription in a manner that is characteristic of bacterial repressors and that this factor could be important in HIV-1 latency.
Crystal Structure of Defensin HNP-3, an Amphiphilic Dimer: Mechanisms of Membrane Permeabilization
Authors: Hill Christopher P. , Yee Jeff , Selsted Michael E. , Eisenberg David
Published: October 2006

Defensins (molecular weight 3500 to 4000) act in the mammalian immune response by permeabilizing the plasma membranes of a broad spectrum of target organisms, including bacteria, fungi, and enveloped viruses. The high-resolution crystal structure of defensin HNP-3 (1.9 angstrom resolution,
R
factor 0.19) reveals a dimeric β sheet that has an architecture very different from other lytic peptides. The dimeric assembly suggests mechanisms by which defensins might bind to and permeabilize the lipid bilayer.
Temperatures of Desert Plants: Another Perspective on the Adaptability of Leaf Size
Authors: Smith William K.
Published: October 2006

Surface temperatures of perennial plants in the Sonoran Desert of California ranged from 20°C above air temperature to over 18°C below air temperature during rapid growth periods following rain. Desert cactus with large photosynthetic stem surfaces had the highest temperatures and lowest transpiration rates. Perennial plants with relatively small leaves had moderate transpiration rates and leaf temperatures close to air temperature. Desert perennials with relatively large leaves had leaf temperatures well below air temperature along with the greatest accompanying transpiration rates of over 20 micrograms per square centimeter per second, but also had correspondingly low temperatures for maximum photosynthesis. The low leaf temperatures measured for these large-leafed species are an exception to the more common pattern for desert plants whereby a smaller leaf size prevents overheating and leads to reductions in transpiration and increased water-use efficiency. The contribution of a larger leaf size to a lower leaf temperature, and thus higher rate of photosynthesis for these large-leafed species, may represent an adaptive pattern previously unrecognized for desert plants.
Toxicity in Resting Cysts of the Red-Tide Dinoflagellate
Gonyaulax excavata
from Deeper Water Coastal Sediments
Authors: Dale Barrie , Yentsch Clarice M. , Hurst John W.
Published: October 2006

For the first time,
Gonyaulax excavata
cysts have been shown to be toxic. Bottom sediments from a water depth of 90 meters off the Maine coast were extremely rich in cysts, which were approximately ten times more toxic than the corresponding motile stages. Cysts are probably ingested by shellfish, thereby causing shellfish toxicity in deeper waters offshore and contributing to shellfish toxicity in shallower coastal waters. A new approach to the problem of paralytic shellfish poisoning is therefore needed, one that takes into account benthic cysts and sedimentary factors affecting their distribution. The possible dangers of spreading poisoning through human activities must be considered.
Regions of Cerebral Ischemia Located by Pyridine Nucleotide Fluorescence
Authors: Welsh Frank A. , O'Connor Michael J. , Langfitt Thomas W.
Published: October 2006

The fluorescence of the reduced form of the endogenous pyridine nucleotide nicotinamide adenine dinucleotide was used to map regions of ischemia in cat brain. A remarkably microheterogeneous pattern of increased fluorescence resulted from a critical level of incomplete cerebral ischemia. The fluorescence pattern suggests that ischemia occurs initially in microwatershed zones between penetrating cerebral arteries.
Control of Embryonic Motoneuron Survival in Vivo by Ciliary Neurotrophic Factor
Authors: Oppenheim Ronald W. , Prevette David , Qin-Wei Yin , Collins Frank , MacDonald John
Published: October 2006

During development of the nervous system, neurons in many regions are overproduced by proliferation, after which the excess cells are eliminated by cell death. The survival of only a proportion of neurons during normal development is thought to be regulated by the limited availability of neurotrophic agents. One such putative trophic agent is ciliary neurotrophic factor (CNTF), a polypeptide that promotes the survival of ciliary, sensory, and sympathetic neurons in vitro. In contrast to the results of in vitro studies, however, the daily treatment of chick embryos in vivo with purified human recombinant CNTF failed to rescue any of these cell populations from cell death, whereas CNTF did promote the in vivo survival of spinal motoneurons. Thus, CNTF may not act as a neurotrophic agent in vivo for those embryonic neurons (especially ciliary neurons) on which it acts in vitro. Rather, CNTF may be required for in vivo survival of motoneurons.
Primary Structure and Functional Activity of a Phosphatidylinositol-Glycan-Specific Phospholipase D
Authors: Scallon Bernard J. , Fung Wen-Jian C. , Tsang T. Chris , Li Shirley , Kado-Fong Helen , Huang Kuo-Sen , Kochan Jarema P.
Published: October 2006

A phosphatidylinositol-glycan-specific phospholipase D (PI-G PLD) that specifically hydrolyzes the inositol phosphate linkage in proteins anchored by phosphatidylinositol-glycans (PI-Gs) has recently been purified from human and bovine sera. The primary structure of bovine PI-G PLD has now been determined and the functional activity of the enzyme has been studied. Expression of PI-G PLD complementary DNA in COS cells produced a protein that specifically hydrolyzed the inositol phosphate linkage of the PI-G anchor. Cotransfection of PI-G PLD with a PI-G-anchored protein resulted in the secretion of the PI-G-anchored protein. The results suggest that the expression of PI-G PLD may influence the expression and location of PI-G-anchored proteins.
Late Holocene Tectonic Activity Along the Margins of the Sinai Subplate
Authors: Neev David , Friedman G. M.
Published: October 2006

Remarkable folding and uplifting movements were active along the western margin of the Sinai subplate (the Bardawil Lagoon and its periphery) during the Upper Holocene. The coasts of the eastern margin (Gulf of Elat) were also uplifted during the same tectonic phase. The nature of this activity is discussed in relation to the regional tectonic framework.
Carbon-14 Dating: A Comparison of Beta and Ion Counting
Authors: Stuiver Minze
Published: October 2006

Accelerator ion counting compares favorably with conventional beta counting. The major advantage of ion counting is that milligram samples can be analyzed. When sample size is not limiting, ion counting complements beta counting for the more routine carbon-14 determinations. Further development is needed before ion counting can achieve the same high precision as beta counting for large samples (± 2 per mil). A solution to the background variability has to be found before ion counting can be used to date samples back to the 75,000-year limit of beta counting.
Identification of p53 Gene Mutations in Bladder Cancers and Urine Samples
Authors: Sidransky David , Von Eschenbach Andrew , Tsai Yvonne C. , Jones Peter , Summerhayes Ian , Marshall Fray , Paul Meera , Green Pearl , Hamilton Stanley R. , Frost Philip , Vogelstein Bert
Published: October 2006

Although bladder cancers are very common, little is known about their molecular pathogenesis. In this study, invasive bladder cancers were evaluated for the presence of gene mutations in the p53 suppressor gene. Of 18 tumors evaluated, 11 (61 percent) were found to have genetic alterations of p53. The alterations included ten point mutations resulting in single amino acid substitutions, and one 24-base pair deletion. In all but one case, the mutations were associated with chromosome 17p allelic deletions, leaving the cells with only mutant forms of the p53 gene product. Through the use of the polymerase chain reaction and oligomer-specific hybridization, p53 mutations were identified in 1 to 7 percent of the cells within the urine sediment of each of three patients tested. The p53 mutations are the first genetic alterations demonstrated to occur in a high proportion of primary invasive bladder cancers. Detection of such mutations ex vivo has clinical implications for monitoring individuals whose tumor cells are shed extracorporeally.
Reproductive Behavior and Health in Consanguineous Marriages
Authors: Bittles Alan H. , Mason William M. , Greene Jennifer , Rao N. Appaji
Published: October 2006

In many regions of Asia and Africa, consanguineous marriages currently account for approximately 20 to 50% of all unions, and preliminary observations indicate that migrants from these areas continue to contract marriages with close relatives when resident in North America and Western Europe. Consanguinity is associated with increased gross fertility, due at least in part to younger maternal age at first livebirth. Morbidity and mortality also may be elevated, resulting in comparable numbers of surviving offspring in consanguineous and nonconsanguineous families. With advances in medicine and public health, genetic disorders will account for an increased proportion of disease worldwide. Predictably, this burden will fall more heavily on countries and communities in which consanguinity is strongly favored, as the result of the expression of deleterious recessive genes. However, studies conducted in such populations indicate that the adverse effects associated with inbreeding are experienced by a minority of families.
Coral Reef Growth in the Galápagos: Limitation by Sea Urchins
Authors: Glynn Peter W. , Wellington Gerard M. , Birkeland Charles
Published: October 2006

The regular echinoid
Eucidaris thouarsii
is a conspicuous omnivore on coral bottoms in the Galápagos. Unlike
Eucidaris
in Panama and mainland Ecuador, Galápagos
Eucidaris
are large and abundant and graze heavily in the open on live corals day and night. These differences are probably due in large part to more intense predation by fishes on mainland compared with island urchin populations. An assessment of coral growth versus coral attrition from grazing shows that
Eucidaris
interferes with the establishment of pocilloporid reef frame and therefore reduces reef growth in the Galápagos.
Djurleite (Cu
1.94
S) and Low Chalcocite (Cu
2
S): New Crystal Structure Studies
Authors: Evans Howard T.
Published: October 2006

Additional x-ray structure studies on low chalcocite generally confirm the previously reported structure but show that either disorder is present or the true space group is not
P
2
1
/
c
but
Pc
, four of the 96 copper atoms in the monoclinic unit cell taking on twofold (linear) coordination. The crystal structure of djurleite has been solved in space group
P
2
1
/
n
, the monoclinic cell having parameters
a
= 26.897,
b
= 15.745, and
c
= 13.565 angstroms; β = 90.13 °; and a content of 248 copper and 128 sulfur atoms. Of the 62 different copper atoms in the structure, 52 are in threefold, triangular coordination with sulfur, nine in tetrahedral, and one in linear coordination.
Plasma Waves Near Venus: Initial Observations
Authors: Scarf F. L. , Taylor W. W. L. , Green I. M.
Published: October 2006

The Pioneer Venus electric field detector observes significant effects of the interaction of the solar wind with the ionosphere of Venus all along the orbiter trajectory. Information is obtained on plasma oscillations emitted by suprathermal electrons beyond the bow shock, on sharp and diffuse shock structures, and on wave-particle interaction phenomena that are important near the boundary of the dayside ionosphere.
Pleistocene Climate: Deterministic or Stochastic?
Authors: Kominz Michelle A. , Pisias Nicklas G.
Published: October 2006

Application of a simple linear model to the earth's ice volume record of the past 730,000 years indicates that although forcing by variations in the earth's orbital parameters of tilt and precession is real, it is small (less than 25 percent of the variance in the record). No relationship with the eccentricity is observed. This indicates that the Pleistocene glacial variations are largely stochastic in nature.
Chemical Warfare Agents: Verification of Compounds Containing the Phosphorus-Methyl Linkage in Waste Water
Authors: Verweij Albert , Boter Henk L. , Degenhardt Carla E. A. M.
Published: October 2006

The chemical analysis of the waste water from plants that manufacture chemicals is a nonintrusive method for confirming a suspected violation of the prohibition against the production of chemical warfare agents. The chemical structure of most nerve gases is related to that of methylphosphonic acid, whereas most organophosphorus pesticides have the phosphoric acid structure. On the basis of this characteristic difference, a procedure has been developed in which the presence of a nerve gas, its decomposition products, or its starting materials in waste water (Rhine River and Meuse River water) is reflected by the appearance of methylphosphonic acid as a breakdown product after hydrolysis. This acid is concentrated and converted into a volatile compound by methylation. After cleanup, the ester may be separated from related compounds by gas chromatography and is detected by means of a specific detector for phosphorus. The detection limit of nerve gases by this procedure is approximately 1 nanomole per liter of water. The scope and limitations of the method are discussed.
Search Image Formation in the Blue Jay (
Cyanocitta cristata
)
Authors: Pietrewicz Alexandra T. , Kamil Alan C.
Published: October 2006

Blue jays trained to detect
Catocala
moths in slides were exposed to two types of slide series containing these moths: series of one species and series of two species intermixed. In one-species series, detection ability increased with successive encounters with one prey type. No similar effect occurred in two-species series. These results are a direct demonstration of a specific search image.
Rainfall Changes in Summer Caused by St. Louis
Authors: Changnon Stanley A.
Published: October 2006

Precipitation in and around St. Louis was investigated to study urban influences on summer precipitation conditions. Prerain winds were used to define the "downwind area" where influences would be greatest, and wind-sorted rains were combined into monthly and summer totals. Seventy-five percent of the 16 rain patterns revealed a rainfall maximization downwind of the city, and the rainfall in the downwind area was 22.7 percent more than the rainfall upwind of St. Louis where no urban influences existed. Various statistical tests of the summer rainfall distribution reveal the downwind rainfall to be significantly greater than elsewhere and supportive of other findings that St. Louis increases rainfall.
Microcracking and Healing in Granites: New Evidence from Cathodoluminescence
Authors: Sprunt Eve S. , Nur Amos
Published: October 2006

Quartz grains in granitic rocks usually have blue cathodoluminescence (CL). Within the blue-luminescing grains, there are often red-luminescing domains which are frequently impossible to detect without CL contrast. This finding suggests that the red-luminescing quartz is sealing preexisting microcracks. The presence of these now-healed microcracks has important implications with respect to the role of pore fluid pressure and fluid transfer in metamorphism, the origin of granites, long-period crustal deformation, earthquake mechanics, physical properties of rocks, and deep-seated geothermal energy.
Aluminum in Seawater: Control by Inorganic Processes
Authors: Hydes David J.
Published: October 2006

The distribution of dissolved aluminum in open ocean waters is probably controlled by the solution of aluminum from atmospherically derived particles and bottom sediments balanced against scavenging by siliceous shells of dead organisms. Variations in the aluminum concentration within vertical hydrographic profiles are small as compared to those for other trace metals. Aluminum concentrations in the Atlantic and Pacific are inversely related to the silica contents of these oceans.
Dinosaurs: A Jurassic Assemblage from Patagonia
Authors: Bonaparte J. F.
Published: October 2006

The first Jurassic assemblage of carnosaurs and sauropods from South America has been recorded in the Callovian-Oxfordian beds of Patagonia. The new genus of carnosaur is related to
Allosaurus
. The two new genera of sauropods are cetiosaurids, comparable with but different from
Cetiosaurus
, and more primitive than
Haplocanthosaurus
.
Maternal Haploids of
Nicotiana tabacum
L. from Seed
Authors: Burk L. G. , Gerstel D. U. , Wernsman E. A.
Published: October 2006

Abundant seeds of high germinability are obtained when
Nicotiana tabacum
is pollinated by
Nicotiana africana
. Most of the seedlings die at the cotyledonary stage. The remaining seedlings are viable F
1
hybrids or maternal haploids that can be easily distinguished. This simple method of producing
Nicotiana tabacum
haploids offers an alternative to anther culture.
Coal Conversion Technologies: Some Health and Environmental Effects
Authors: Morris S. C. , Moskowitz P. D. , Sevian W. A. , Silberstein S. , Hamilton L. D.
Published: October 2006

Several technologies to convert coal to liquid and gaseous fuels are being developed in the United States, some with support from the Department of Energy. Substitution of these technologies for those currently being used will produce different health and environmental hazards. In this article, selected health and environmental effects of four coal conversion and four existing technologies are compared. For each technology, the emission estimates for complete fuel cycles, including all steps in fuel use from extraction to the end use of space and water heating by electricity or direct combustion, were prepared by means of the Brookhaven Energy System Network Simulator model. Quantitative occupational health and safety estimates are presented for the extraction, transportation, distribution, processing, and conversion activities associated with each technology; also included are some public health damage estimates arising from fuel transportation and air pollution impacts. Qualitative estimates of health damage due to polycyclic organic matter and reduced sulfur are discussed. In general, energy inefficiencies, environmental residuals, and hence implied environmental effects and health damage increase in the order: (i) direct combustion of natural gas and oil, (ii) direct combustion of synthetic gas and oil, (iii) central-station electric power produced from synthetic gas, (iv) central-station electric power produced from coal, and (v) central-station electric power produced by the combustion of synthetic liquid fuels. The compliance and conflict of these technologies with the amendments of the Clean Air Act and other legislation are discussed.
Effect of Cosmic Rays on Computer Memories
Authors: Ziegler J. F. , Lanford W. A.
Published: October 2006

A method is developed for evaluating the effects of cosmic rays on computer memories and is applied to some typical memory devices. The sea-level flux of cosmic-ray particles is reviewed and the interaction of each type of particle with silicon is estimated, with emphasis on processes that produce bursts of charge. These charge pulses are then related to typical computer large-scale integrated circuit components and cosmic-ray-induced errors are estimated. The effects of shielding (such as building ceilings and walls), altitude, and solar cycle are estimated. Cosmic-ray nucleons and muons can cause errors in current memories at a level of marginal significance, and there may be a very significant effect in the next generation of computer memory circuitry. Error rates increase rapidly with altitude, which may be used for testing to make electronic devices less sensitive to cosmic rays.
Three-Dimensional Structure of the LDL Receptor-Binding Domain of Human Apolipoprotein E
Authors: Wilson Charles , Wardell Mark R. , Weisgraber Karl H. , Mahley Robert W. , Agard David A.
Published: October 2006

Human apolipoprotein E, a blood plasma protein, mediates the transport and uptake of cholesterol and lipid by way of its high affinity interaction with different cellular receptors, including the low-density lipoprotein (LDL) receptor. The three-dimensional structure of the LDL receptor-binding domain of apoE has been determined at 2.5 angstrom resolution by x-ray crystallography. The protein forms an unusually elongated (65 angstroms) four-helix bundle, with the helices apparently stabilized by a tightly packed hydrophobic core that includes leucine zipper-type interactions and by numerous salt bridges on the mostly charged surface. Basic amino acids important for LDL receptor binding are clustered into a surface patch on one long helix. This structure provides the basis for understanding the behavior of naturally occurring mutants that can lead to atherosclerosis.
Imaging Photopolarimeter on Pioneer Saturn
Authors: Gehrels T. , Baker L. R. , Beshore E. , Blenman C. , Burke J. J. , Castillo N. D. , DaCosta B. , Degewij J. , Doose L. R. , Fountain J. W. , Gotobed J. , KenKnight C. E. , Kingston R. , McLaughlin G. , McMillan R. , Murphy R. , Smith P. H. , Stoll C. P. , Strickland R. N. , Tomasko M. G. , Wijesinghe M. P. , Coffeen D. L. , Esposito L.
Published: October 2006

An imaging photopolarimeter aboard Pioneer 11, including a 2.5-centimeter telescope, was used for 2 weeks continuously in August and September 1979 for imaging, photometry, and polarimetry observations of Saturn, its rings, and Titan. A new ring of optical depth < 2 × 10
–3
was discovered at 2.33 Saturn radii and is provisionally named the F ring; it is separated from the A ring by the provisionally named Pioneer division. A division between the B and C rings, a gap near the center of the Cassini division, and detail in the A, B, and C rings have been seen; the nomenclature of divisions and gaps is redefined. The width of the Encke gap is 876 ± 35 kilometers. The intensity profile and colors are given for the light transmitted by the rings. A mean particle size ≲ 15 meters is indicated; this estimate is model-dependent. The D ring was not seen in any viewing geometry and its existence is doubtful. A satellite, 1979 S 1, was found at 2.53 ± 0.01 Saturn radii; the same object was observed ∼ 16 hours later by other experiments on Pioneer 11. The equatorial radius of Saturn is 60,000 ± 500 kilometers, and the ratio of the polar to the equatorial radius is 0.912 ± 0.006. A sample of polarimetric data is compared with models of the vertical structure of Saturn's atmosphere. The variation of the polarization from the center of the disk to the limb in blue light at 88° phase indicates that the density of cloud particles decreases as a function of altitude with a scale height about one-fourth that of the gas. The pressure level at which an optical depth of 1 is reached in the clouds depends on the single-scattering polarizing properties of the clouds; a value similar to that found for the Jovian clouds yields an optical depth of 1 at about 750 millibars.
Lead Isotope Identification of Sources of Galena from Some Prehistoric Indian Sites in Ontario, Canada
Authors: Farquhar R. M. , Fletcher I. R.
Published: October 2006

Lead isotopic compositions of 12 galenas from five late Archaic-initial Woodland grave and habitation sites in southern Ontario have made it possible to determine the "most likely" source areas for the galenas. For one of the oldest sites (Finlan), the most likely source is in the southwestern Upper Mississippi Valley (Wisconsin-Illinois-Iowa) mineral district. The seven Finlan galenas exhibit a range of isotopic ratios; three of the largest specimens have substantial isotopic variations (up to 1.8 percent in the ratio of lead-207 to lead-206) on a scale of a few centimeters. This suggests that the lead isotopic zoning ascribed to the Upper Mississippi Valley area is not sufficiently well defined to enable us to determine if all the Finlan samples were derived from a single mineral deposit. Galenas from the other sites (Constance Bay, Hind, Bruce Boyd, and Picton) most probably originated in the southeastern Ontario-northwestern New York area. Isotopic differences among the Constance Bay, Hind, and Bruce Boyd galenas, on the one hand, and the Picton galena, on the other, suggest that at least two distinct sources in that region were exploited.
Early Miocene Subglacial Basalts, the East Antarctic Ice Sheet, and Uplift of the Transantarctic Mountains
Authors: Stump Edmund , Sheridan Michael F. , Borg Scott G. , Sutter John F.
Published: October 2006

Subglacially erupted volcanic rocks from Mount Early and Sheridan Bluff, Antarctica, yield whole-rock potassium-argon dates and argon-40/argon-39 release spectra of Early Miocene age. Field associations suggest the existence of the East Antarctic ice sheet and significant uplift of the Transantarctic Mountains by that time.
Anthophora
Bees: Unusual Glycerides from Maternal Dufour's Glands Serve as Larval Food and Cell Lining
Authors: Norden Beth , Batra Suzanne W. T. , Fales Henry M. , Hefetz Abraham , Shaw G. John
Published: October 2006

The Dufour's gland of
Anthophora abrupta
, a solitary bee, secretes a complex mixture of liquid triglycerides containing one long-chain and two short-chain fatty acids. This is applied inside the earthen brood cells and added to the provision, where it is converted, perhaps by enzymes from the bee's saliva or gut, to solid diglycerides that are later eaten by the bee larvae. This use of Dufour's gland secretion as food and its nutritive function are reminiscent of the royal jelly secreted by honey bees.
Dissolution of Pyroxenes and Amphiboles During Weathering
Authors: Berner Robert A. , Sjöberg E. L. , Velbel Michael A. , Krom Michael D.
Published: October 2006

Augite, hypersthene, diopside, and hornblende all undergo dissolution during weathering by means of the formation, growth, and coalescence of distinctive, parallel, lens-shaped etch pits. Similar etch features can be produced if these minerals are treated in the laboratory with concentrated hydrofluoric acid plus hydrochloric acid. These pits most likely form at dislocation outcrops, and their shape and orientation are controlled primarily by the crystallography of the underlying mineral. The results are similar to those found for soil feldspars and suggest that silicate weathering, in general, takes place by selective etching and not by general attack of the surface with consequent rounding as necessitated by bulk diffusion-type weathering theories.
Sediment-Water Chemical Exchange in the Coastal Zone Traced by in situ Radon-222 Flux Measurements
Authors: Martens Christopher S. , Kipphut George W. , Klump J. Val
Published: October 2006

In situ radon-222 flux experiments conducted in benthic chambers in Cape Lookout Bight, a small marine basin on the North Carolina coast, reveal that enhanced chemical transport across the sediment-water interface during summer months is caused by abiogenic bubble tube structures. Transport rates for dissolved radon, methane, and ammonium more than three times greater than those predicted on the basis of molecular diffusion occur when open tubes are maintained by semi-diurnal low-tide bubbling.
Internal Solitons in the Andaman Sea
Authors: Osborne A. R. , Burch T. L.
Published: October 2006

The solitary wave is a localized hydrodynamic phenomenon that can occur because of a balance between nonlinear cohesive and linear dispersive forces in a fluid. It has been shown theoretically, and observed experimentally, that some solitary waves have properties analogous to those of elementary particles, and the waves have therefore been named solitons. During a measurement program in the Andaman Sea near northern Sumatra, large-amplitude, long internal waves were observed with associated surface waves called tide rips. Using theoretical results from the physics of nonlinear waves, it is shown that the internal waves are solitons and their interactions with surface waves are described.