bluuebunny/crossref_metadata_2025 huggingface dataset:
Efflux of Cyclic Nucleotides from Rat Pineal: Release of Guanosine 3′,5′-Monophosphate from Sympathetic Nerve Endings
Authors: Zatz Martin , O'Dea Robert F.
Published: October 2006

Potassium and norepinephrine stimulate the efflux of adenosine 3′,5′-monophosphate (cyclic AMP) and guanosine 3′,5′-monophosphate (cyclic GMP) from intact pineal glands. The postsynaptic β-adrenergic receptor mediates the efflux of cyclic AMP. In contrast, the efflux of cyclic GMP requires calcium and intact nerve endings. It appears that sympathetic nerve endings may release cyclic GMP into the synaptic space.
Structurally Homologous Ligand Binding of Integrin Mac-1 and Viral Glycoprotein C Receptors
Authors: Altieri Dario C. , Etingin Orli R. , Fair Daryl S. , Brunck Terence K. , Geltosky John E. , Hajjar David P. , Edgington Thomas S.
Published: October 2006

Three spatially distant surface loops were found to mediate the interaction of the coagulation protein factor X with the leukocyte integrin Mac-1. This interacting region, which by computational modeling defines a three-dimensional macromotif in the catalytic domain, was also recognized by glycoprotein C (gC), a factor X receptor expressed on herpes simplex virus (HSV)-infected endothelial cells. Peptidyl mimicry of each loop inhibited factor X binding to Mac-1 and gC, blocked monocyte generation of thrombin, and prevented monocyte adhesion to HSV-infected endothelium. These data link the ligand recognition of Mac-1 to established mechanisms of receptor-mediated vascular injury.
Estimates of Cenozoic Oceanic Sedimentation Rates
Authors: Davies Thomas A. , Hay William W. , Southam John R. , Worsley thomas R.
Published: October 2006

Estimation of average Cenozoic sedimentation rates for the Atlantic, Indian, and Pacific oceans indicates global synchronous fluctuations. Paleocene-early Eocene and late Eocene-early Miocene rates are only a fraction of middle Eocene and middle Miocene-Recent rates. These changes must reflect significantly different modes of continental weathering, which may be due to alternate states of atmospheric circulation marked by reduction of global precipitation.
Comparison of Radioactive and Stable Tl
+
Diffusion in Potassium Chloride: Demonstration of a Transmutation Effect
Authors: Wei G. C. T. , Wuensch B. J.
Published: October 2006

Radioactive
204
Tl
+
was found to diffuse in potassium chloride up to three times more rapidly than stable Tl
+
. The difference is attributed to the
204
Pb
2+
daughter element produced by β
–
emission. A theoretical model accounts satisfactorily for the discrepancy and indicates that internal sources of cation vacancies are effective in maintaining electroneutrality at all but low temperatures.
Bag Cell Control of Egg Laying in Freely Behaving
Aplysia
Authors: Pinsker Harold. M. , Dudek F. Edward
Published: October 2006

Neuroendocrine (bag cell) control of egg laying was studied in freely behaving
Aplysia
. Surgical lesions showed that bag cells are not necessary for egg laying, although they play a crucial role in its control, and that the pleurovisceral connectives are the afferent pathway to the bag cells. Recording in vivo showed that synchronous bag cell spikes progressively invade the network, leading to prolonged repetitive firing that initiates natural egg laying.
Coevolution of Foraging in
Bombus
and Nectar Dispensing in
Chilopsis
: A Last Dreg Theory
Authors: Whitham Thomas G.
Published: October 2006

Flowers of
Chilopsis linearis
dispense nectar into pools and grooves. The bumblebee,
Bombus sonorus
, extracts pool nectar at a rate seven times faster than groove nectar. The result is the coevolution of a plant-pollinator system in which bees, while foraging efficiently, increase the number of flowers visited per calorie of nectar reward provided by the plant.
Clonal Deletion Versus Clonal Anergy: The Role of the Thymus in Inducing Self Tolerance
Authors: Ramsdell Fred , Fowlkes B. J.
Published: October 2006

During development in the thymus, T cells are rendered tolerant to self antigens. It is now apparent that thymocytes bearing self-reactive T cell receptors can be tolerized by processes that result in physical elimination (clonal deletion) or functional inactivation (clonal anergy). As these mechanisms have important clinical implications for transplantation and autoimmunity, current investigations are focused on understanding the cellular and molecular interactions that generate these forms of tolerance.
Pollen Influx and Volcanic Ash
Authors: Mehringer Peter J. , Blinman Eric , Petersen Kenneth L.
Published: October 2006

Pollen influx can be used to estimate the duration of short-term depositional events. When applied to volcanic ashes, it may also provide information on the season and ecological effects of ashfall. In our initial application of the method to volcanic ashes from Lost Trail Pass, Bitterroot Mountains, Montana, we have illustrated that (i) two falls of Glacier Peak ash, which occurred about 11,250
14
C years ago, were separated by 10 to 25 years; and (ii) volcanic ash from a major eruption of Mount Mazama (about 6700
14
C years ago) first fell in the autumn and 4.6 centimeters of ash was deposited before the following spring. We also believe there is a reasonable probability that (i) about 1 centimeter of ash fell during the following year and about 1.7 centimeters fell the year after; (ii) in all, the sporadic primary Mazama ashfall lasted for nearly 3 years; (iii) Mazama ash resulted in low lake productivity, as measured by the occurrence of
Botryococcus
and
Pediastrum
; (iv) Mazama ash, perhaps through a mulching effect, may have produced increased vigor and pollen production in some sagebrush steppe genera; and (v) as measured by the records of fossil pollen and acid-resistant algae, effects on the aquatic and terrestrial ecosystems were short-lived. With refinement of the methods and broader geographic application, pollen influx studies may prove valuable for separating the regional and chronological details of tephra attributed to Mazama, Glacier Peak, and other Cascade Range volcanoes.
Creative Penmanship in Animal Testing Prompts FDA Controls
Authors: Smith R. Jeffrey
Published: October 2006

Inaccurate science, sloppy science, fraudulent science—these are the greatest threats to the health and safety of the American people. Whether the science is wrong because of clerical error, or because of poor technique, or because of incompetence, or because of negligence, is less important than the fact that it is wrong. For if it is wrong, and if the FDA did not know it was wrong, then the protective regulatory barrier between a potentially dangerous drug and the patient is removed.-SENATOR EDWARD KENNEDY (D-Mass.), in congressional hearings on preclinical testing.
Atomic Structure of Ferredoxin-NADP
+
Reductase: Prototype for a Structurally Novel Flavoenzyme Family
Authors: Karplus P. Andrew , Daniels Mark J. , Herriott Jon R.
Published: October 2006

The three-dimensional structure of spinach ferredoxin- NADP
+
reductase (NADP
+
nicotinamide adenine dinucleotide phosphate) has been determined by x-ray diffraction at 2.6 angstroms (Å) resolution and initially refined to an
R
factor of 0.226 at 2.2 Å resolution. The model includes the flavin-adenine dinucleotide (FAD) prosthetic group and the protein chain from residue 19 through the carboxyl terminus at residue 314 and is composed of two domains. The FAD binding domain (residues 19 to 161) has an antiparallel β barrel core and a single α helix for binding the pyrophosphate of FAD. The NADP binding domain (residues 162 to 314) has a central five-strand parallel β sheet and six surrounding helices. Binding of the competitive inhibitor 2′-phospho-AMP (AMP, adenosine monophosphate) places the NADP binding site at the carboxyl-terminal edge of the sheet in a manner similar to the nucleotide binding of the dehydrogenase family. The structures reveal the key residues that function in cofactor binding and the catalytic center. With these key residues as a guide, conclusive evidence is presented that the ferredoxin reductase structure is a prototype for the nicotinamide dinucleotide and FAD binding domains of the enzymes NADPH-cytochrome P450 reductase, NADPH-sulfite reductase, NADH-cytochrome b
5
reductase, and NADH-nitrate reductase. Thus this structure provides a structural framework for the NADH- or NADPH-dependent flavoenzyme parts of five distinct enzymes involved in photosynthesis, in the assimilation of inorganic nitrogen and sulfur, in fatty-acid oxidation, in the reduction of methemoglobin, and in the metabolism of many pesticides, drugs, and carcinogens.
Nitrous Oxide: Emission from Soils During Nitrification of Fertilizer Nitrogen
Authors: Bremner J. M. , Blackmer A. M.
Published: October 2006

Nitrous oxide is released from soils to the atmosphere during nitrification of ammonium and ammonium-producing fertilizers under aerobic conditions as well as by denitrification of nitrate under anaerobic conditions. Emissions of nitrous oxide during nitrification of fertilizer nitrogen may be significant in regard to the potential threat of fertilizer-derived nitrous oxide to the stratospheric ozone layer. Such emissions can be greatly reduced through the use of nitrapyrin, which inhibits nitrification of ammonium by soil microorganisms.
Predicting Future Atmospheric Carbon Dioxide Levels
Authors: Siegenthaler U. , Oeschger H.
Published: October 2006

Results from different models for the natural carbon dioxide cycle are compared. Special emphasis is given to the type of ocean modeling (diffusive deep-sea or two-box ocean), behavior of the biosphere, and value of the oceanic buffer factor against carbon dioxide uptake. According to the most probable models, the fraction of the cumulative production remaining airborne will be between 46 and 80 percent 100 years from now for any realistic assumptions concerning future carbon dioxide production. For a prescribed maximum increase of 50 percent above the preindustrial carbon dioxide level, the production could grow by about 50 percent until the beginning of the next century, but should then decrease rapidly.
Energy and Water
Authors: Harte John , El-Gasseir Mohamed
Published: October 2006

The geographic and temporal variability of freshwater supply in the United States constrains the choice and level of use of future energy sources. Ecological criteria for acceptable freshwater consumption, together with hydrological data on stream flow, provide a framework for estimating these constraints. The water consumption requirements for a variety of energy options are presented, and comparative judgments drawn. Attention is focused on problems resulting from synthetic, gaseous, and liquid fuel production. Scenarios describing possible future levels of coal and electricity use are analyzed. They point to the importance of water supply constraints in both the eastern and western United States.
Residential Natural Gas Consumption: Evidence That Conservation Efforts to Date Have Failed
Authors: Lehman Richard L. , Warren Henry E.
Published: October 2006

A new short-term natural gas consumption model is developed, tested against American Gas Association sales data, and applied to the question of the effectiveness of conservation efforts. The results indicate that unit residential gas-heating sales per heating degree-day have remained constant in four major gas-consuming regions during the period 1974 to 1976 and that heating sales have not been affected by the recent sharp changes in price.
Assembly of Greek Marble Inscriptions by Isotopic Methods
Authors: Herz Norman , Wenner David B.
Published: October 2006

Classical Greek inscriptions cut in marble, whose association as original stelai by archeological methods was debatable, were selected for study. Using traditional geological techniques and determinations of the per mil increments in carbon-13 and oxygen-18, it was determined that fragments could be positively assigned to three stelai, but that fragments from three other stelai had been incorrectly associated.
Endothelial Expression of a Mononuclear Leukocyte Adhesion Molecule During Atherogenesis
Authors: Cybulsky Myron I. , Gimbrone Michael A.
Published: October 2006

An inducible rabbit endothelial adhesion molecule that is selective for mononuclear leukocytes has been identified. This adhesion protein was expressed on the surface of activated cultured endothelium in two forms, 118 and 98 kilodaltons, the amino-terminal sequence of each being highly homologous to human VCAM-1. In dietary hypercholesterolemic and Watanabe heritable hyperlipidemic rabbit models of atherosclerosis, this adhesion molecule was found to be expressed in a localized fashion by aortic endothelium that overlies early foam cell lesions. This lesion-localized expression suggests a potential endothelium-dependent mechanism for mononuclear leukocyte recruitment during atherogenesis and may provide a molecular marker for early atherosclerosis.
Past Glacial Activity in the Canadian High Arctic
Authors: England J. , Bradley R. S.
Published: October 2006

Field observations on northeast Ellesmere Island indicate that the maximum advance of the northwest Greenland Ice Sheet was about 100 kilometers beyond its present margin. This occurred before the outermost Ellesmere Island ice advance, which took place more than 30,000 years before present (B.P.). Recession from the Ellesmere Island ice margin began at least 28,000 to 30,000 and possibly more than 35,000 years B.P. During this sequence of glacial events, significant land areas remained free of ice. The late Wisconsin ice extent along both northeast Ellesmere Island and northwest Greenland was extremely limited, leaving an ice-free corridor along Kennedy and Robeson channels. Recession from these ice margins is indicated by initial postglacial emergence around 8100 to 8400 years B.P. The relatively minor extent of late Wisconsin ice in the High Arctic probably reflects a period of extreme aridity occasioned by the buildup of the Laurentide Ice Sheet to the south.
Photocontrol of Boron Metabolism in Sea Grasses
Authors: Pulich Warren M.
Published: October 2006

Boron is taken up in the dark and is excreted in response to light by the leaves of the marine vascular plant,
Halophila engelmannii
Ascherson. This phenomenon makes possible the study of boron metabolism in a higher plant without the stress of boron deficiency. Dependence of boron excretion on photosynthetic CO
2
fixation suggests that an organoboron complex between boron and a newly formed carbon compound from photosynthesis is selectively excreted.
Sm-Nd and Rb-Sr Chronology of Continental Crust Formation
Authors: McCulloch M. T. , Wasserburg G. J.
Published: October 2006

Samarium-neodymium and rubidium-strontium isotopic systematics, together with plausible assumptions regarding the geochemical evolution of continental crust material, have been used to ascertain the times at which segments of continental crust were formed. Analyses of composites from the Canadian Shield representing portions of the Superior, Slave, and Churchill structural provinces indicate that these provinces were all formed within the period 2.5 to 2.7 aeons. It has been possible to determine the mean age of sediment provenances, as studies of sedimentary rocks suggest that the samarium-neodymium isotopic system is not substantially disturbed during sedimentation or diagenesis.
The Physics Interviewing Project: A Tour of Interviews in Asia
Authors: Callen Earl , Scadron Michael
Published: October 2006

The Physics Interviewing Project assists graduate physics departments in evaluating foreign applicants. Supported by some 20 universities, two interviewers, both working scientists, travel abroad and interview students individually for about 1 hour each. Prospective teaching assistants are rated on physics knowledge, problem-solving ability, and English language proficiency. Ratings on all interviewees are sent to all supporting schools and other schools as requested. The Project aids able students from countries that have no physics Ph.D. programs (Indonesia, Malaysia, Thailand) to obtain assistantships and Ph.D.'s abroad, assists in the technological development of those countries, and helps U.S. schools in selecting the most promising foreign candidates. A similar program should be beneficial in other sciences.
River Quality Assessment Implications of a Prototype Project
Authors: Rickert David A. , Hines Walter G.
Published: October 2006

The U.S. Geological Survey recently completed an intensive river quality assessment study of the Willamette River basin, Oregon. The most noteworthy finding was that across-the-board advanced waste treatment was not the answer to the problem of meeting stringent water quality standards established for the Willamette River. This implies that rigid nationwide standards and regulations are likely to result in unneeded expenditures in some river basins and in unachieved standards in others. It was also found that existing water quality data collected under monitoring- and surveillance-type programs are inadequate for defining the critical cause-effect relationships that control river quality problems. Intensive, synoptic surveys keyed to local problems and conditions are required to provide an adequate information base for making key management decisions.
DNA: A Model Compound for Solution Studies of Macromolecules
Authors: Pecora R.
Published: October 2006

Well-defined, monodisperse, homologous series of oligonucleotides and DNA restriction fragments may now be produced and used as models of rigid and semirigid rodlike molecules in solution. Information from optical experiments on these model systems aids in the formulation and testing of theories of macromolecular dynamics in both dilute and concentrated solution.
Evoked Response Correlate of Symbol and Significate
Authors: Grastyán E. , John E. R. , Bartlett F.
Published: October 2006

Changing the source and intensity of the auditory signal to six trained cats responding to meaningful auditory stimuli permits exogenous and endogenous processes in the auditory evoked potential to be separated. For short-latency exogenous processes, latency and amplitude depend on the parameters of the physical stimulus. However, the amplitude and shape of longer-latency endogenous processes are essentially independent of the location and intensity of the signal source and seem to be invariant concomitants of the significance of the signal.
Mission-Oriented Research for Light Machinery
Authors: Tesar Delbert
Published: October 2006

The time of intelligent machines is upon us. But the United States is not actively pursuing this rich field of technological development. This is evidenced by the U.S. trade deficit of $9 billion in this market in 1977. The synergistic approach of Japan, Germany, Russia, and other countries to research, development, and demonstration among government, academic, and industrial groups is paying big dividends in vital U.S. markets. This article outlines a specific solution in terms of a U.S. national research policy for light machinery and robotics.
Carbon-13 Depletion in a Subalpine Lake: Carbon Flow Implications
Authors: Rau Greg
Published: October 2006

Plankton (larger than 76 micrometers) taken from an undisturbed oligotrophic was found to have δ
13
C values (=
13
C/
12
C relative to the Pee Dee belemnite standard) ranging from –44 to –47 per mil. This extraordinary
13
C depletion, together with characteristics of the inorganic carbon pool, indicates that lake respiration as well as surrounding soil respiration provide important carbon sources for plankton production in this lake.
Characterization of a Human TAR RNA-Binding Protein That Activates the HIV-1 LTR
Authors: Gatignol Anne , Buckler-White Alicia , Berkhout Ben , Jeang Kuan-Teh
Published: October 2006

Human immunodeficiency virus type 1 (HIV-1) gene expression is activated by Tat, a virally encoded protein. Tat trans-activation requires viral (trans-activation—responsive; TAR) RNA sequences located in the R region of the long terminal repeat (LTR). Existing evidence suggests that Tat probably cooperates with cellular factors that bind to TAR RNA in the overall trans-activation process. A HeLa complementary DNA was isolated and characterized that encodes a TAR RNA-binding protein (TRBP). TRBP activated the HIV-1 LTR and was synergistic with Tat function.
Adenovirus-Mediated Transfer of a Recombinant α1-Antitrypsin Gene to the Lung Epithelium in Vivo
Authors: Rosenfeld Melissa A. , Siegfried Wolfgang , Yoshimura Kunihiko , Yoneyama Koichi , Fukayama Masashi , Stier Larue E. , Pääkkö Paavo K. , Gilardi Pascale , Stratford-Perricaudet Leslie D. , Perricaudet Michel , Jallat Sophie , Pavirani Andrea , Lecocq Jean-Pierre , Crystal Ronald G.
Published: October 2006

The respiratory epithelium is a potential site for somatic gene therapy for the common hereditary disorders α1-antitrypsin (α1AT) deficiency and cystic fibrosis. A replication-deficient adenoviral vector (Ad-α1AT) containing an adenovirus major late promoter and a recombinant human α1AT gene was used to infect epithelial cells of the cotton rat respiratory tract in vitro and in vivo. Freshly isolated tracheobronchial epithelial cells infected with Ad-α1AT contained human α1AT messenger RNA transcripts and synthesized and secreted human α1AT. After in vivo intratracheal administration of Ad-α1AT to these rats, human α1AT messenger RNA was observed in the respiratory epithelium, human α1AT was synthesized and secreted by lung tissue, and human α1AT was detected in the epithelial lining fluid for at least 1 week.
Size Fractionation Methods: Measuring Plutonium in Respirable Dust
Authors: Hayden J. A.
Published: October 2006

Methods used to evaluate the inhalation hazard of soil contaminated with plutonium were investigated. Four soil fractionation procedures were used to separate three size fractions of soil particles taken from two locations at the Department of Energy's Rocky Flats facility. The results show that increasing amounts of soil mass and plutonium activity (0.5 to 38 percent and 7 to 84 percent, respectively) remain in the fraction of soil smaller than 10 micrometers as the in situ particle associations are increasingly disrupted by physical and chemical forces. The introduction of forces of dispersion unrelated to ambient conditions yields results that are unrelated to the original particle associations.
Solar Rotation Determined from Thomas Harriot's Sunspot Observations of 1611 to 1613
Authors: Herr Richard B.
Published: October 2006

In 1612 the sun's mean sidereal rotation rate was only 13.3° per day based on a series of 199 unpublished drawings by Harriot. By comparison with the rates in 1625 to 1626 and 1642 to 1644 it appears that the solar rotation was accelerating significantly in the cycles leading up to the Maunder minimum.
Guanosine 3′,5′-Monophosphate: A Central Nervous System Regulator of Analgesia
Authors: Cohn Major L. , Cohn Marthe , Taylor Floyd H.
Published: October 2006

The dibutyryl derivative of guanosine 3′,5′-monophosphate (cyclic GMP), administered centrally, totally abolishes response to noxious stimuli without depressing the central nervous system. Analgesic properties of the nucleotide are not reversed by naloxone. Microinjected intracerebrally into different sites, dibutyryl cyclic GMP does not mimic the action of morphine. Pharmacological effects of dibutyryl cyclic GMP suggest that endogenous cyclic GMP modulates an inhibitory pain pathway distinct from that on which morphine acts.
Maternal Behavior as a Regulator of Polyamine Biosynthesis in Brain and Heart of the Developing Rat Pup
Authors: Butler Stephen R. , Suskind Mark R. , Schanberg Saul M.
Published: October 2006

Rat pups removed from the mother and placed in a warm incubator for 1 hour or more show a 50 percent reduction in ornithine decarboxylase activity in the brain and heart. The decline is not caused by lack of nutrition. Instead, these studies suggest that active maternal behavior is necessary to maintain normal polyamine metabolism in brain and heart of the pup during development.
Molecular Structure of an Unusual Organoactinide Hydride Complex Determined Solely by Neutron Diffraction
Authors: Broach Robert W. , Schultz Arthur J. , Williams Jack M. , Brown George M. , Manriquez Juan M. , Fagan Paul J. , Marks Tobin J.
Published: October 2006

The structure of an unusual organometallic complex, {Th[(CH
3
)
5
C
5
]
2
H(μ -H)}
2
⋅ C
6
H
5
CH
3
, has been determined from neutron diffraction data, using only the direct-methods program MULTAN. Besides providing accurate metrical information on the first organometallic actinide hydride complex, these results have general and far-reaching implications concerning the complexity and size of crystal structures that can be elucidated solely on the basis of neutron diffraction data.
Ross Sea Region in the Middle Miocene: A Glimpse into the Past
Authors: Brady Howard , Martin Helene
Published: October 2006

Fossil diatoms and pollen from sea-floor sediments beneath the Ross Ice Shelf indicate that a permanent ice cover was not present in the Ross Sea and that vegetation including angiosperms, gymnosperms, and ferns existed on at least some parts of the largely glaciated Antarctic mainland in the late middle Miocene.
Ross Ice Shelf Sea Temperatures
Authors: Gilmour A. E.
Published: October 2006

Two temperature profiles recorded by a sensitive bathythermograph at the Ross Ice Shelf Project site (82°22.5′S, 168°37.5′W) are presented. From the shape of the profiles it is concluded that an inflow of water at intermediate depths provides a source of heat to drive a regime in which ice is melted from the interface at a depth of 360 meters. Melting maintains the temperature of a thick layer under the ice at about –2.14°C, close to the ambient freezing temperature. A very well mixed layer about 35 meters thick was found at the seabed.
Biological Bulldozers and the Evolution of Marine Benthic Communities
Authors: Thayer Charles W.
Published: October 2006

During the Phanerozoic, the diversity of immobile suspension feeders living on the surface of soft substrata (ISOSS) declined significantly. Immobile taxa on hard surfaces and mobile taxa diversified. Extinction rates of ISOSS were significantly greater than in other benthos. These changes in the structure of benthic communities are attributed to increased biological disturbance of the sediment (bioturbation) by diversifying deposit feeders.
Initial Pioneer Venus Magnetic Field Results: Dayside Observations
Authors: Russell C. T. , Elphic R. C. , Slavin J. A.
Published: October 2006

Initial observations by the Pioneer Venus magnetometer in the sunlit ionosphere reveal a dynamic ionosphere, very responsive to external solar wind conditions. The locations of the bow shock and ionosphere are variable. The strength of the magnetic field just outside the ionopause is in approximate pressure balance with the thermal plasma of the ionosphere and changes markedly from day to day in response to changes in solar wind pressure. The field strength in the ionosphere is also variable from day to day. The field is often weak, at most a few gammas, but reaching many tens of gammas for periods of the order of seconds. These field enchantments are interpreted as due to the passage of spacecraft through flux ropes consisting of bundles of twisted field lines surrounded by the ionospheric plasma. The helicity of the flux varies through the flux tube, with low pitch angles on the inside and very large angles in the low-field outer edges of the ropes. These ropes may have external or internal sources. Consistent with previous results, the average position of the bow shock is much closer to the planet than would be expected if the solar wind were completely deflected by the planet. In total, these observations indicate that the solar wind plays a significant role in the physics of the Venus ionosphere.
Dual Function of the Damselfly Penis: Sperm Removal and Transfer
Authors: Waage Jonathan K.
Published: October 2006

The male of
Calopteryx maculata
(Beauvois) (Odonata) uses its penis not only to transfer sperm to the female but also to remove sperm deposited in the female's sperm storage organs from previous matings. Apparently, no such sperm removal function has previously been attributed to the intromittent organ of any animal.
Ammonia Volatilization from Senescing Leaves of Maize
Authors: Farquhar G. D. , Wetselaar R. , Firth P. M.
Published: October 2006

Ammonia release by plants growing in normal air is reported. Contrary to observations made at high ambient ammonia concentrations, corn plants did not absorb ammonia in normal air but released it as they senesced, even while photosynthesizing actively.
Extraction and Analysis of Organic Cations from Acid Solution with Strong Electric Fields and Mass Spectrometry
Authors: Ligon Woodfin V.
Published: October 2006

High electric fields have been used to extract organic cations from solutions of small organic molecules in polyphosphoric acid. The cations have been analyzed by mass spectrometry. Production of ions by this method is shown to be related to ease of protonation by acid rather than to ionization potential.
Natural Polyesters: Dufour's Gland Macrocyclic Lactones Form Brood Cell Laminesters in
Colletes
Bees
Authors: Hefetz Abraham , Fales Henry M. , Batra Suzanne W. T.
Published: October 2006

Bees in the genus
Colletes
make their brood cells in the ground and coat them with a highly resistant, waterproof, transparent membrane. This membrane is a polyester constructed mainly from 18-hydroxyoctadecanoic acid and 20-hydroxyeicosanoic acid, which are stored as their corresponding lactones in the Dufour's gland of the bee. When lining the cells, the bee secretes its glandular content, and the membrane is apparently a product of polycondensation reaction of its contents. This appears to be the first report of a naturally occurring linear polyester. The term laminester (lamina ≃ layer + ester) for this class of compounds is proposed.
Development of Vegetation and Climate in the Southwestern United States
Authors: Van Devender Thomas R. , Spaulding W. Geoffrey
Published: October 2006

Plant macrofossils in ancient packrat middens document the presence of woodland communities in most of the present Chihuahuan, Sonoran, and Mohave deserts in the southwestern United States during the late Wisconsinan (22,000 to 11,000 years before present by radiocarbon dating). Warm desert species were common in the woodlands at lower elevations and mixed conifer and subalpine forests were present at high elevations. Inferred mild, wet winters and cool summers produced unusual plant and animal associations compared to those of today. Montane communities acquired modern aspects and more mesophytic species disappeared from lower woodlands about 11,000 years ago. Early Holocene xeric woodlands and an inferred winter precipitation regime persisted until about 8000 years ago. The present circulation patterns, rainfall regimes, and biotic distributions probably formed as a result of the melting of the continental ice sheets. Southwestern communities appear to have responded quickly to climatic changes compared to the gradual responses of central and eastern United States forest communities.
Geothermal Convection Through Oceanic Crust and Sediments in the Indian Ocean
Authors: Anderson Roger N. , Hobart Michael A. , Langseth Marcus G.
Published: October 2006

Closely spaced heat flow surveys at four sites on the flanks of the Central Indian Ridge and the Southeast Indian Ridge delineate a pattern of oscillatory heat flow which can only result from cellular convection of oceanic bottom water through the oceanic crust and overlying sediment. These cells have a wavelength of 5 to 10 kilometers and are presently active in sea floor 18 × 10
6
, 25 × 10
6
, and 45 × 10
6
years old of the Crozet Basin and in sea floor 55 × 10
6
years old of the Madagascar Basin. The precise measurement of nonlinear temperature profiles makes it possible to calculate the conductive and convective heat transfer components through the sea floor. Even in the oldest sites, geothermal convection is still a major component of heat transfer through both the crust and sedimentary layers. These observations coupled with the results of earlier oceanwide geothermal studies indicate that more than one-third of the entire surface area of the world's ocean floor contains presently active geothermal convection that is cellular in plan form.
Power-Line Harmonic Radiation: Can It Significantly Affect the Earth's Radiation Belts?
Authors: Thorne Richard M. , Tsurutani Bruce T.
Published: October 2006

It has been suggested that harmonic radiation from the earth's 50- and 60-hertz power transmission lines might significantly influence the distribution of electrons in the radiation belts. On the basis of observations presented here, it seems advisable to accept such a hypothesis with caution. New evidence suggests that power-line radiation does not play any major role in the nonadiabatic dynamics of radiation belt electrons.
Voyager 1: Energetic Ions and Electrons in the Jovian Magnetosphere
Authors: Vogt R. E. , Cook W. R. , Cummings A. C. , Garrard T. L. , Gehrels N. , Stone E. C. , Trainor J. H. , Schardt A. W. , Conlon T. , Lal N. , McDonald F. B.
Published: October 2006

The observations of the cosmic-ray subsystem have added significantly to our knowledge of Jupiter's magnetosphere. The most surprising result is the existence of energetic sulfur, sodium, and oxygen nuclei with energies above 7 megaelectron volts per nucleon which were found inside of Io's orbit. Also, significant fluxes of similarly energetic ions reflecting solar cosmic-ray composition were observed throughout the magnetosphere beyond 11 times the radius of Jupiter. It was also found that energetic protons are enhanced by 30 to 70 percent in the active hemisphere. Finally, the first observations were made of the magnetospheric tail in the dawn direction out to 160 Jupiter radii.
Chesterton Soil Concretions: Ilmenite and Not Iron-Manganese Cementing Matrix
Authors: White Kenneth L.
Published: October 2006

Dark reddish-brown spherules are common in soils of the Chesterton soil series of a high marine terrace in southern California. The spherules are concretionary in structure and are bound by ilmenite rather than by an iron-manganese complex. The spherules have been mislabeled both with respect to structure and mineralogy.
Fast Ionic Transport in Solids
Authors: Farrington Gregory C. , Briant Jacqueline L.
Published: October 2006

The discovery of inorganic solids with ionic conductivities comparable to those of aqueous electrolytes has revolutionized solid-state electrochemistry. Sodium beta alumina, a Na
+
conductor, and Li

x

TiS
2
, an intercalation compound with simultaneous Li
+
and electronic conductivity, are two of the best and most versatile fast ionic conductors. A wide variety of cations can replace Na
+
in beta alumina and Li
+
in Li

x

TiS
2
and change the properties of the materials. Sodium beta alumina and Li

x

TiS
2
are currently used in the development of high-energy density batteries for electric vehicles and electrical utility load leveling. Current research in solid ionic conductors is exploring new intercalation compounds, solid polymer electrolytes, and alkali ion and proton transport in crystalline solids.
Evergreen Coniferous Forests of the Pacific Northwest
Authors: Waring R. H. , Franklin J. F.
Published: October 2006

The massive, evergreen coniferous forests in the Pacific Northwest are unique among temperate forest regions of the world. The region's forests escaped decimation during Pleistocene glaciation; they are now dominated by a few broadly distributed and well-adapted conifers that grow to large size and great age. Large trees with evergreen needle- or scale-like leaves have distinct advantages under the current climatic regime. Photosynthesis and nutrient uptake and storage are possible during the relatively warm, wet fall and winter months. High evaporative demand during the warm, dry summer reduces photosynthesis. Deciduous hardwoods are repeatedly at a disadvantage in competing with conifers in the regional climate. Their photosynthesis is predominantly limited to the growing season when evaporative demand is high and water is often limiting. Most nutrients needed are also less available at this time. The large size attained by conifers provides a buffer against environmental stress (especially for nutrients and moisture). The long duration between destructive fires and storms permits conifers to outgrow hardwoods with more limited stature and life spans.
Seasat Low-Rate Data System
Authors: Brown J. W. , Cleven G. C. , Klose J. C. , Lame D. B. , Yamarone C. A.
Published: October 2006

The Seasat low-rate data system is a distributed, nonreal-time, magnetic-tape system for information processing. Its function is to apply the necessary calibrations, corrections, and conversions to yield geophysically meaningful products from raw spacecraft telemetry data. It also provides a remotely accessible catalog of satellite data.
Conformation of [Leu5]Enkephalin from X-Ray Diffraction: Features Important for Recognition at Opiate Receptor
Authors: Smith G. David , Griffin Jane F.
Published: October 2006

The conformation of [Leu5]enkephalin is produced by a Tyr-Gly-Gly-Phe β bend stabilized by antiparallel hydrogen bonding between tyrosine and phenylalanine. On the basis of a comparison of the observed structure with the structure of known opiate agonists, three hydrophilic and two hydrophobic regions have been identified as contributing to the recognition of the molecule at the opiate receptor site.
Monolayer Crystallization of Flagellar L-P Rings by Sequential Addition and Depletion of Lipid
Authors: Akiba Toshihiko , Yoshimura Hideyuki , Namba Keiichi
Published: October 2006

The L-P ring complex is thought to be a molecular bushing that supports flagellar motor rotation at about 10,000 revolutions per minute with presumably very little friction. Structural studies of this complex have been limited because only very small amount of samples are available. Therefore devising an efficient method of crystallization was essential. The addition of a phospholipid and its subsequent slow depletion by phospholipase A
2
have been used to successfully grow well-ordered monolayer crystals that extend up to about 10 micrometers. The interaction of the L-P ring complex with lipid membranes was also visualized during this process.
Venus Winds Are Zonal and Retrograde Below the Clouds
Authors: Counselman C. C. , Gourevitch S. A. , King R. W. , Loriot G. B. , Prinn R. G.
Published: October 2006

Winds in the lower atmosphere of Venus, inferred from three-dimensional radio interferometric tracking of the descents of the Pioneer day and north probes, are predominantly easterly with speeds of about 1 meter per second near the surface, 50 meters per second at the bottom of the clouds, and more than 200 meters per second within the densest, middle cloud layer. Between about 25 and 55 kilometers altitude the average flow was slanted equatorward, with superimposed wavelike motions and alternating layers of high and low shear.
Effects of Energy Conservation in Residential and Commercial Buildings
Authors: Hirst Eric , Hannon Bruce
Published: October 2006

In 1977, heating, cooling, lighting, and other operations in residential and commercial buildings used 27 quads (1 quad = 10
15
British thermal units) of energy. This is more than one-third of the nation's total energy budget. Future trends in energy use in buildings are likely to depend strongly on fuel prices and government policies designed to save energy. Three scenarios are examined: (i) a base line in which fuel prices rise as projected by the Department of Energy; (ii) a conservation case that includes higher gas and oil prices plus the regulatory, financial incentive, and information programs authorized by the 94th Congress and proposed in the April 1977 National Energy Plan; and (iii) another conservation case that also includes new technologies (more efficient equipment, appliances, and structures). These scenarios are analyzed for changes in energy use, costs, and employment by means of detailed engineering-economic models of energy use in residential and commercial buildings developed at the Oak Ridge National Laboratory and input-output analyses developed at the University of Illinois.
Market Penetration Characteristics for Energy Production and Atmospheric Carbon Dioxide Growth
Authors: Laurmann J. A.
Published: October 2006

Estimates are given for the maximum rate at which fossil fuel consumption can be reduced by the introduction of noncarbon-based energy sources, according to the market penetration time concept. These estimates indicate an immediate need to implement a revised energy policy if major climatic changes induced by increased amounts of carbon dioxide are to be avoided in the next century. However, application of market penetration ideas to energy consumption is new and may not be valid for the prediction of future trends.
Induction of Stalk and Spore Cell Differentiation by Cyclic AMP in Slugs of
Dictyostelium discoideum
Authors: Feit Ira N. , Fournier George A. , Needleman Robert D. , Underwood Mara Z.
Published: October 2006

Multicellular masses of the cellular slime mold
Dictyostelium discoideum
, under conditions which ordinarily suppress cell differentiation, develop clusters of stalk cells and spore cells when implanted with Sephadex particles that had been soaked in 5 × 10
-3
M
cyclic adenosine monophosphate (AMP). A possible relation exists between oxygen gradients, cyclic AMP gradients, and the pattern of morphogenesis and cell differentiation during fruiting.
Deciphering the Scattering Code Contained in the Resonance Echoes from Fluid-Filled Cavities in Solids
Authors: Gaunaurd Guillermo C. , Überall Herbert M.
Published: October 2006

From the echoes of elastic waves incident on inclusions in solids, one may extract certain resonance features. These "spectral lines" and their widths form a code identifying the material composition of the inclusion in a way that resembles spectroscopy. This idea finds applications in geophysics, materials science, and any field dealing with materials containing inclusions.
Magnesium Isotopic Composition of Interplanetary Dust Particles
Authors: Esat Tezer M. , Brownlee D. E. , Papanastassiou D. A. , Wasserburg G. J.
Published: October 2006

The magnesium isotopic composition of some extraterrestrial dust particles has been measured. The particles are believed to be samples of interplanetary dust, a significant fraction of which originated from the disaggregation of comets and may contain preserved isotopic anomalies. Improvements in mass spectrometric and sample preparation techniques have made it possible to measure the magnesium isotopic composition of the dust particles, which are typically 10 micrometers in size and contain on the order of 10
–10
gram of magnesium. Of the 13 samples analyzed, nine have the terrestrial magnesium isotopic composition within 2 parts per thousand, and one shows isotopic mass fractionation of 1.1 percent per mass unit. A subset of the particles, described as chondritic aggregates, are very close to normal isotopic composition, but their normalized isotopic ratios appear to show nonlinear effects of 3 to 4 parts per thousand, which is near the present limit of detection for samples of this size. The isotopic composition of calcium was also determined in one particle and found to be normal within 2 percent. It is clear that the isotopic composition of interplanetary dust particles can be determined with good precision. Collection of dust particles during the earth's passage through a comet tail or an intense meteor stream may permit laboratory analysis of material from a known comet.
Estuarine Influences on a Continental Shelf Plankton Community
Authors: Turner R. E. , Woo S. W. , Jitts H. R.
Published: October 2006

On the southeastern U.S. continental shelf, phytoplankton primary production and the densities of zooplankton, fish eggs, and fish larvae peak simultaneously in late summer and early fall. Some community response to irregular storm events is observed. However, the gross plankton community dynamics on this shelf are dominated by couplings with the local estuaries and shallow nearshore zone.
A Physical Concept of Soil-Water Equilibria for Nonionic Organic Compounds
Authors: Chiou Cary T. , Peters Louis J. , Freed Virgil H.
Published: October 2006

Soil-water equilibrium data suggest that the transfer of nonionic chemicals from water to soil may be described in terms of a hypothesis of solute partitioning in the soil organic matter. This concept allows estimation of soil-water distribution coefficients either from solvent-water partition coefficients or aqueous solubilities.
Widmanstaetten Patterns in Josephinite, a Metal-Bearing Terrestrial Rock
Authors: Bird John M. , Bassett William A. , Weathers Maura S.
Published: October 2006

Widmanstaetten patterns have been found in several specimens of josephinite, a complex, metamorphosed, metal-bearing rock from placers on serpentinized peridotite in southwest Oregon. The patterns, in interior less-altered regions of the specimens, are typical of exsolution textures produced during slow cooling of a homogeneous metal. The bulk composition of the metal phases indicates that the homogeneous metal must have existed at temperatures above 500°C. Josephinite Widmanstaetten patterns are the first known in terrestrial rock. We interpret them as further evidence that josephinite was derived from the mantle.
Deep Methane Maxima in the Northwest Caribbean Sea: Possible Seepage Along the Jamaica Ridge
Authors: Brooks James M.
Published: October 2006

Methane concentrations as great as 30,000 nanoliters per liter were measured on two cruises in the northwest Caribbean Sea. Such concentrations are three orders of magnitude higher than Bunsen solubilities would predict. Although shallow maxima may result from in situ microbial activity, the deeper maxima appear to result from massive seepage (estimated at 1 × 10
8
to 10 × 10
8
liters per day) along the Jamaica Ridge.
Serpentine Minerals: Intergrowths and New Combination Structures
Authors: Veblen David R. , Buseck Peter R.
Published: October 2006

The serpentine minerals chrysotile, lizardite, and antigorite have been found intimately intergrown with each other and with talc, chlorite, and amphibole in incompletely reacted chain silicates. High-resolution transmission electron microscopy has revealed new variations in serpentine planar and roll structures, as well as regions of mixed-layer silicate consisting of serpentine and talc layers.
Blood Pressure Control—Special Role of the Kidneys and Body Fluids
Authors: Guyton Arthur C.
Published: October 2006

The arterial pressure of the adult human rarely deviates from normal by more than 10 to 15 percent during each day. To achieve such constancy, the body has a network of pressure control systems. Several are based on neural receptors that respond within seconds to help correct any abnormal pressure. The activities of these systems are followed within minutes by activation of hormonal controllers. Within hours or days, a kidney pressure control system is induced that increases body fluid volume when the pressure falls (or decreases the volume when the pressure rises). This kidney-fluid system is the dominant method of establishing long-term pressure control.
Edison and the Pure Science Ideal in 19th-Century America
Authors: Hounshell David A.
Published: October 2006

Between 1878 and 1882, key members of the American scientific community played an important role in Thomas A. Edison's work on electric lighting. Impressed by his abilities, these scientists came to regard Edison as a peer and led him to see himself as a scientific man. But Edison's high standing among scientists and the American public and his professed self-image as a scientist provoked America's noted experimental physicist, Henry A. Rowland, to make a "Plea for pure science" before the American Association for the Advancement of Science in 1883.