bluuebunny/crossref_metadata_2025 huggingface dataset:
Excitatory Synaptic Responses Mediated by GABA
A
Receptors in the Hippocampus
Authors: Michelson Hillary B. , Wong Robert K. S.
Published: October 2006

Gamma-aminobutyric acid (GABA) is a major inhibitory neurotransmitter in the cortex. Activation of postsynaptic GABA
A
receptors hyperpolarizes cells and inhibits neuronal activity. Synaptic responses mediated by GABA
A
receptors also strongly excited hippocampal neurons. This excitatory response was recorded in morphologically identified interneurons in the presence of 4-aminopyridine or after elevation of extracellular potassium concentrations. The synaptic excitation sustained by GABA
A
receptors synchronized the activity of inhibitory interneurons. This synchronized discharge of interneurons in turn elicited large-amplitude inhibitory postsynaptic potentials in pyramidal and granule cells. Excitatory synaptic responses mediated by GABA
A
receptors may thus provide a mechanism for the recruitment of GABAergic interneurons through their recurrent connections.
Functional Modulation of Brain Sodium Channels by Protein Kinase C Phosphorylation
Authors: Numann Randal , Catterall William A. , Scheuer Todd
Published: October 2006

Voltage-gated sodium channels, which are responsible for the generation of action potentials in the brain, are phosphorylated by protein kinase C (PKC) in purified form. Activation of PKC decreases peak sodium current up to 80 percent and slows its inactivation for sodium channels in rat brain neurons and for rat brain type IIA sodium channel α subunits heterologously expressed in Chinese hamster ovary cells. These effects are specific for PKC because they can be blocked by specific peptide inhibitors of PKC and can be reproduced by direct application of PKC to the cytoplasmic surface of sodium channels in excised inside-out membrane patches. Modulation of brain sodium channels by PKC is likely to have important effects on signal transduction and synaptic transmission in the central nervous system.
Thermal Radiation in Metabolic Chambers
Authors: Porter Warren P.
Published: October 2006

Emissivities and ratios of surface areas of metabolic chambers and their contents have been usually ignored in studies of the metabolic rates of animals. Failure to take these factors into account can lead to errors in the interpretation of results.
Superior Conjunction of Pioneer 6
Authors: Goldstein R. M.
Published: October 2006

Spectrograms of the radio signals from Pioneer 6 were taken as the spacecraft was occulted by the sun. The spectral bandwidths increased slowly at first, then very rapidly at 1 degree from the sun. In addition, six solar "events" produced marked increases of bandwidth lasting for several hours. The received signal power seemed unaffected by the solar corona.
A Molecular Basis for Heterosis
Authors: Schwartz Drew , Laughner William J.
Published: October 2006

Alcohol dehydrogenase allodimers composed of an unstable active subunit and a stable but inactive subunit are both active and stable. The implication of this finding for the problem of heterosis is discussed.
Vascular Smooth Muscle Reactivity in Normotensive and Hypertensive Rats
Authors: Spector Sydney , Fleisch Jerome H. , Maling Harriet M. , Brodie Bernard B.
Published: October 2006

Aortic strips from spontaneously hypertensive rats were less responsive than normal animals to the contractile effects of norepinephrine, serotonin, and potassium chloride but more reactive to the relaxant effects of the stimulant of beta receptors, isoproterenol. Thus, hypertension is not the result of an absence of beta receptor or a hypersensitivity of the vascular smooth muscle.
Structure of an Oxygen-Carrying Cobalt Complex
Authors: Wang Bi-Cheng , Schaefer William P.
Published: October 2006

Bis(3-fluorosalicylaldehyde)ethylenediimine cobalt(II), a reversible oxygen-carrying compound, has been crystallized as a tetramer with two oxygen molecules bound to the four cobalt atoms, each oxygen molecule bridging between two metal atoms. These dimers are further linked by two bonds between the oxygen atom of the salicylaldehyde and the cobalt atom. The oxygen-to-oxygen distance, 1.21 angstroms in molecular oxygen, has increased to 1.308(28) angstroms (where the number in parentheses is the estimated standard deviation) in this compound, the shortest distance yet observed in such a bridging arrangement.
Structural Studies on Transfer RNA: Preliminary Crystallographic Analysis
Authors: Labanauskas Mindaugas , Connors Peter G. , Young James D. , Bock Robert M. , Anderegg J. W. , Beeman W. W.
Published: October 2006

Single-crystal diffraction patterns from
Escherichia coli
leucine tRNA and yeast formylmethionine tRNA show a tetragonal lattice for the former, with
a
= 46 Å and
c
= 137 Å, and a hexagonal lattice for the latter, with
a
= 115 Å and
c
= 137 Å. Initial analysis suggests a molecule with a long, double helix parallel to the
c
-axis for both crystals.
Dialects in Elephant Seals
Authors: Le Boeuf Burney J. , Peterson Richard S.
Published: October 2006

Threat vocalizations of male elephant seals
Mirounga angustirostris
vary among four populations on islands off the coast of California and Baja California, Mexico. Males at San Nicolas Island in Southern California emit sound pulses at more than double the rate of males at Año Nuevo Island, 528 kilometers north. Mean pulse rates at San Miguel Island and Isla de Guadalupe (408 and 944 kilometers south of Año Nuevo, respectively) are intermediate to these two. Pulse rate is homogeneous within each population and consistent in the same individual. Other properties of the calls which separate populations are pulse duration and embellishment of the initial or terminal pulse in a series. These geographical differences in vocal behavior resemble local dialects in birds and humans.
Laser Ranging Retro-Reflector: Continuing Measurements and Expected Results
Authors: Alley C. O. , Chang R. F. , Currie D. G. , Poultney S. K. , Bender P. L. , Dicke R. H. , Wilkinson D. T. , Faller J. E. , Kaula W. M. , MacDonald G. J. F. , Mulholland J. D. , Plotkin H. H. , Carrion W. , Wampler E. J.
Published: October 2006

After successful acquisition in August of reflected ruby laser pulses from the Apollo 11 laser ranging retro-reflector (LRRR) with the telescopes at the Lick and McDonald observatories, repeated measurements of the round-trip travel time of light have been made from the McDonald Observatory in September with an equivalent range precision of ±2.5 meters. These acquisition period observations demonstrated the performance of the LRRR through lunar night and during sunlit conditions on the moon. Instrumentation activated at the McDonald Observatory in October has yielded a precision of ±0.3 meter, and improvement to ±0.15 meter is expected shortly. Continued monitoring of the changes in the earth-moon distance as measured by the round-trip travel time of light from suitably distributed earth stations is expected to contribute to our knowledge of the earth-moon system.
Potassium, Rubidium, Strontium, Barium, and Rare-Earth Concentrations in Lunar Rocks and Separated Phases
Authors: Philpotts John A. , Schnetzler C. C.
Published: October 2006

Concentrations of potassium, rubidium, strontium, barium, and rareearth elements have been determined by mass spectrometric isotope dilution for eight Apollo 11 lunar samples and for some separated phases. Potassium and rubidium are at chondritic levels, strontium at 15 times, and barium and rare earths at 30 to 100 times chondritic levels. There are trace element similarities between the lunar samples and basaltic achondrites, terrestrial dredge basalts and the bulk earth. The trace element data appear to be consistent with these lunar samples being the result of limited partial fusion of some material similar to the brecciated eucrite meteorites.
Compressibilities of Lunar Crystalline Rock, Microbreccia, and Fines to 40 Kilobars
Authors: Stephens D. R. , Lilley E. M.
Published: October 2006

The compressibilities of three lunar samples were studied at room temperature from 0 to 40 kilobars. The samples were a fine-grained vesicular crystalline rock (type A), a microbreccia (type C), and fines (type D). All samples were porous. The microbreccia and fines were quite compressible at all pressures; the compressibility of the crystalline rock was somewhat less, being 8.4 megabar
-1
at 1 atmosphere and 1.5 megabar
-1
at 35 kilobars. Some porosity appeared to remain in the samples at all pressures. Thus the pressure-volume data derived from these samples may be representative of porous surface and near-surface material in the vicinity of the Apollo 11 landing site but may not be representative of lunar material at depth.
Organic Analysis of the Returned Lunar Sample
Authors: Abell Paul I. , Draffan G. H. , Eglinton Geoffrey , Hayes John M. , Maxwell James R. , Pillinger Colin T.
Published: October 2006

Lunar fines have been examined for organic compounds by crushing, programmed heating, hydrofluoric acid etching, and solvent extraction. Products were examined by mass spectroscopy. A variety of small organic molecules, including methane and other hydrocarbons, accompanied the release of the rare gases when the sample was heated in a stepwise fashion to 900°C under vacuum. Methane is more abundant (abundance on the order of 1 part per million) than argon in the matrix-entrapped gases liberated by hydrofluoric acid etching of lunar fines. Methane is also present in a dark portion of the gas-rich meteorite Kapoeta.
Ghar-i-Mordeh Gusfand (Cave of the Dead Sheep): A New Mousterian Locality in North Afghanistan
Authors: Dupree Louis , Lattman Laurence H. , Davis Richard S.
Published: October 2006

The Middle Paleolithic of Central Asia is little known and less understood. Several sites have been excavated in Soviet Central Asia, but few have been adequately presented. Recent excavations in north Afghanistan may throw new light on the problem because of the size of the rock shelter involved and its relative geologic dating.
Disintegration of Charged Liquid Jets: Results with Isopropyl Alcohol
Authors: Huebner A. L.
Published: October 2006

Disintegration processes occurring with charged jets of isopropyl alcohol differ in several respects from results obtained with water. Although bimodal distributions of drop size shift to smaller diameters with increasing electrification for both liquids, the lower surface tension of the alcohol promotes the formation of secondary jets and a fan configuration not observed for water.
Inside-Out Red Cell Membrane Vesicles: Preparation and Purification
Authors: Steck Theodore L. , Weinstein Ronald S. , Straus John H. , Wallach Donald F. H.
Published: October 2006

Plasma membranes purified from human red cells were converted into small vesicles by disruption in alkaline buffer of low ionic strength. Most of these vesicles were inside-out. The presence of divalent cations prevented this inversion. The inside-out vesicles were separated from right-side-out vesicles by centrifugation to equilibrium in dextran density gradients.
Pyroxferroite: Stability and X-ray Crystallography of Synthetic Ca
0.15
Fe
0.85
SiO
3
Pyroxenoid
Authors: Lindsley Donald H. , Burnham Charles W.
Published: October 2006

Synthetic Ca
0.15
Fe
0.85
SiO
3
pyroxenoid has the same (pyroxmangite) structure and very nearly the same composition as pyroxferroite, a new mineral found in Apollo 11 lunar samples. The synthetic material is not stable below pressures of approximately 10 kilobars. It appears likely that the lunar pyroxferroite has persisted in a metastable state for some billions of years.
Metobromuron: Acetylation of the Aniline Moiety as a Detoxification Mechanism
Authors: Tweedy B. G. , Loeppky Carol , Ross James A.
Published: October 2006

p
-Bromoaniline is rapidly acetylated by four soil microorganisms. Two fungal species convert metobromuron to
p
-bromoacetanilide, but a bacterial and an algal species do not metabolize metobromuron. Acetylation may serve as a detoxification mechanism by competing with azobenzene formation in utilizing the aniline formed by metabolism of substituted urea herbicides.
Terrestrial and Aquatic Orientation in the Starhead Topminnow,
Fundulus notti
Authors: Goodyear C. Phillip
Published: October 2006

Starhead topminnows from various shores of a small woodland pond were displaced to unfamiliar surroundings, and their orientation was tested in aquatic and terrestrial arenas. These fish used a sun compass to move in a direction which, at the location of their capture, would have returned them to the land-water interface. The fish accomplished directional terrestrial locomotion by using the position of the sun to align its body for each jump. On heavily overcast days many fish were unable to orient their bodies in a consistent direction from, jump to jump; this inability to orient resulted in random rather than linear movement. There was considerable individual variation in terrestrial locomotor ability.
Norepinephrine Turnover and Metabolism in Rat Brain after Long-Term Administration of Imipramine
Authors: Schildkraut Joseph J. , Winokur Andrew , Applegate Clarence W.
Published: October 2006

The rate of disappearance of intracisternally administered tritiated norepinephrine from rat brain is decreased after a single dose of the tricyclic antidepressant imipramine. During long-term administration of imipramine, however, the rate of disappearance of tritiated norepinephrine from brain gradually increases, and there is a concurrent decrease in the content of endogenous norepinephrine in brain. These findings may help to explain why antidepressant effects are observed clinically only after long-term treatment with imipramine.
Subliming Ice Surfaces: Freeze-Etch Electron Microscopy
Authors: Davy J. Gordon , Branton Daniel
Published: October 2006

Vacuum sublimation of oriented single crystals of ice at temperatures from -110 to -60 degrees Celsius was studied by electron microscopy with the freeze-etch technique. Sublimation etches the ice surface to produce pits and asperities and above -85 degrees Celsius causes extreme surface roughening. The etch pits are ascribed to surface dislocations, and the extreme roughening is ascribed to the departure from unity of the vaporization coefficient. The asperities could not be attributed to impurities; they may be related to the whiskers that others have observed at higher temperatures.
Saccharomyces cerevisiae
: A Diffusible Sex Factor
Authors: Duntze Wolfgang , MacKay Vivian , Manney Thomas R.
Published: October 2006

A hormone-like substance is secreted by α mating-type cells of heterothallic yeast strains. It induces in cells of the opposite mating type,
a
, a morphological change characteristic of the mating process. Secretion of this substance and mating ability have some common genetic determinants. In partially purified preparations, the substance has properties of an oligopeptide.
Impairment of Shock Avoidance Learning after Long-Term Alcohol Ingestion in Mice
Authors: Freund Gerhard
Published: October 2006

Chronic alcohol consumption impaired the learning of a two-way shuttle box avoidance task in mice 10 to 14 days after the discontinuation of ethanol in the diet. Control groups received laboratory chow ad libitum or were pair-fed with the alcohol-consuming mice by diets containing isocaloric amounts of sucrose. The performance of the two control groups was indistinguishable from each other, and only the ethanol-consuming mice performed poorly. It was therefore concluded that alcohol consumption per se and not a nutritional deficiency was responsible for the impairment of learning.
Anomalous Water: Characterization by Physical Methods
Authors: Rabideau S. W. , Florin A. E.
Published: October 2006

Anomalous water samples have been prepared in fused quartz capillaries from pure water in an unsaturated atmosphere. In agreement with observations of other investigators, water prepared in this manner, after concentration, exhibited an increased viscosity, a lowered vapor pressure, a phase separation at low temperatures, an index of refraction of 1.48 or greater, and a depression of the temperature of maximum density. However, electron microprobe examination indicated that a significant weight fraction of these concentrated anomalous water residues consists of sodium, boron, and oxygen. The presence of about 6 percent boron was also confirmed through neutron activation analyses and by mass spectrometric measurements. A parallel is drawn between the similar physical properties of anomalous water and highly concentrated sodium tetraborate solutions. The possibility of polymorphism in liquid water should be accepted only with serious reservations.
Phylum Ectoprocta, Order Cheilostomata: Microprobe Analysis of Calcium, Magnesium, Strontium, and Phosphorus in Skeletons
Authors: Schopf Thomas J. M. , Allan J. R.
Published: October 2006

Calcium, magnesium, and strontium occur in approximately constant ratios in traverses through skeletal walls of a single mineralogy (either calcite or aragonite). Skeletal walls of more than one mineralogy have the magnesium-rich layer (calcite) surrounding the living chamber and the strontium-rich layer (aragonite) on the outside. In contrast, phosphorus may be present in greater or lesser amounts in different parts of the same calcite skeletal wall. Aragonitic crystallites appear oriented roughly perpendicular to skeletal walls, whereas calcitic crystallites are parallel to skeletal walls.
Conditioned Vocalizations as a Technique for Determining Visual Acuity Thresholds in Sea Lions
Authors: Schusterman Ronald J. , Balliet Richard F.
Published: October 2006

Aerial visual acuity and underwater visual acuity were measured in two sea lions
(Zalophus californianus)
by training them to emit click bursts if they saw a striped target or to remain silent if they saw a gray target. The closest grating spacings that could be resolved both in air and under water subtended a visual angle of 5.5 minutes of arc at a distance of 5.5 meters.
Common Modifications of Trimeric G Proteins and ras Protein: Involvement of Polyisoprenylation
Authors: Finegold Alan A. , Schafer William R. , Rine Jasper , Whiteway Malcolm , Tamanoi Fuyuhiko
Published: October 2006

The heterotrimeric guanine nucleotide-binding regulatory proteins act at the inner surface of the plasma membrane to relay information from cell surface receptors to effectors inside the cell. These G proteins are not integral membrane proteins, yet are membrane associated. The processing and function of the γ subunit of the yeast G protein involved in mating-pheromone signal transduction was found to be affected by the same mutations that block ras processing. The nature of these mutations implied that the γ subunit was polyisoprenylated and that this modification was necessary for membrane association and biological activity. A microbial screen was developed for pharmacological agents that inhibit polyisoprenylation and that have potential application in cancer therapy.
Natural Oil Seepage at Coal Oil Point, Santa Barbara, California
Authors: Allen Alan A. , Schlueter Roger S. , Mikolaj Paul G.
Published: October 2006

Aerial, surface, and underwater investigations reveal that natural seeps off Coal Oil Point, California, introduce about 50 to 70 barrels (approximately 8,000 to 11,000 liters) of oil per day into the Santa Barbara Channel. The resulting slicks are several hundred meters wide and are of the order of 10
-5
centimeters thick; tarry masses within these slicks frequently wash ashore.
Radar Interferometric Observations of Venus at 70-Centimeter Wavelength
Authors: Campbell D. B. , Jurgens R. F. , Dyce R. B. , Harris F. S. , Pettengill G. H.
Published: October 2006

A radar interferometer was used to map unambiguously the surface reflectivity of Venus in the polarized mode at a wavelength of 70 centimeters. The observed region extended from 260° to 30° in longitude and from -60° to 50° in latitude with a surface resolution of approximately 3° by 3°. The result agrees well in most respects with earlier maps made elsewhere at shorter wavelengths and, in addition, discloses a number of new "features."
Pacific Geomagnetic Secular Variation
Authors: Doell Richard R. , Cox Allan
Published: October 2006

We have considered several different types of records of long-period geomagnetic secular variation: direct measurements made in geomagnetic observatories; paleomagnetic measurements on Hawaiian lava flows with accurately known ages in the interval 0 to 200 years; paleomagentic measurements on Hawaiian lava flows with loosely determined ages within the interval 200 to 10,000 years ago; and worldwide paleomagnetic measurements of the average geomagnetic angular dispersion recorded in lava flows that formed during the past 0.7 million years. All these magnetic records indicate that, during this time, the nondipole component of the earth's field was lower in the central Pacific than elsewhere, as it is today. This, in turn, indicates that there is some type of inhomogeneity in the lower mantle which is coupled to the earth's core in such a way as to suppress the generation of the nondipole field beneath the central Pacific. With the present incomplete state of knowledge about the processes that give rise to the earth's field, it is uncertain whether undulations in the core-mantle interface or lateral variations in the composition and physical state of the lower mantle are ultimately responsible for the pattern of secular variation seen at the earth's surface.
Synaptic Adjustment after Deafferentation of the Superior Colliculus of the Rat
Authors: Lund R. D. , Lund J. S.
Published: October 2006

Eyes were removed from rats shortly after birth, when there are few formed synapses in the colliculus. It was found that synaptogenesis continues to give a near-normal ratio of terminals containing either spheroidal or flattened vesicles. After eye removal in adult rats, however, reinvasion of synaptic sites vacated by degenerate optic terminals occurs, with an incomplete return toward a normal proportion of synaptic types.
Carbon Monoxide: Its Role in Photochemical Smog Formation
Authors: Westberg Karl , Cohen Norman , Wilson K. W.
Published: October 2006

The photochemistry of trace amounts of isobutene and oxides of nitrogen in an atmosphere of air was studied both in the presence and in the absence of small amounts of carbon monoxide. Carbon monoxide accelerates the reaction as measured by nitric oxide oxidation or ozone formation. This finding has relevance to photochemical smog formation.
Molecular Biology of Synaptic Receptors
Authors: De Robertis Eduardo
Published: October 2006

A special proteolipid (a hydrophobic protein) has been extracted and purified from nerve-ending membranes and total particulate matter of gray areas of the central nervous system. Such a proteolipid shows a high affinity for binding
d
-tubocurarine, serotonin, and atropine and has been called receptor proteolipid. The interaction of this proteolipid with atropine sulfate was studied with light scattering and polarization of fluorescence. The changes observed, which follow a cooperative type of curve, were attributed to the aggregation of the proteolipid macromolecules. Such a phenomenon was then observed under the electron microscope.

A receptor proteolipid having a high affinity for binding acetylcholine, hexamethonium, and other cholinergic drugs was isolated and purified from electric tissue of fishes and from electroplax membranes. Such a proteolipid was also extracted from membranes from which acetylcholinesterase had been removed, and it was concluded that this enzyme and the receptor proteolipid are two different macromolecules. A high affinity binding site with a dissociation constant of K
1
equal to 10
-7
and about ten sites with K
2
equal to 10
-5
were recognized in the receptor proteolipid.

Under the electron microscope the receptor proteolipid of brain appears as a rod-shaped macromolecule which may assume paracrystalline arrays with 10
-8
molar atropine sulfate. Similarly the receptor proteolipid from electric tissue and from skeletal muscle may form paracrystalline arrays under the action of acetylcholine and hexamethonium.

A model of the cholinergic receptor based on the properties of the proteolipid is presented. Preliminary work indicates the possibility of obtaining a biophysical response to acetylcholine when the receptor proteolipid is embedded in artificial bilayered lipid membranes.
A Correlation between Gametophytic and Sporophytic Characteristics in
Zea mays
L.
Authors: Mulcahy David L.
Published: October 2006

If a mixture of types of corn pollen, identified by genetic markers, is applied to the silks of other inbred lines, the rate of pollen tube growth often varies with type of pollen. This gametophytic differential is correlated with a sporophytic differential—relatively heavier seeds in seed mixtures result from fertilization by gametes from faster growing tubes. The increased seed weight is due to greater competitive ability of the zygotes thus formed.
Redwoods: A Population Model
Authors: Bosch C. A.
Published: October 2006

The chief conclusion to be drawn from the results of this study is that redwoods are amazingly vigorous. The results support both the lumber companies and the conservationists. There is no question that old growth giant redwoods must be preserved. Only commercial greed could be a basis for refuting that stand. On the other hand, the lumber companies seem to be supported in their contention that redwoods can be farmed without driving them to extinction. The central issue revolves around the old trees. And here profit is the big factor.

Lumbering is an important industry in California, and redwood lumbering represents about 20 percent of the industry. Most of the big names in timber, such as Weyerhaeuser and Georgia-Pacific, are involved in logging the California redwood. At the current rate of logging, particularly of old growth stands, the Bank of America estimates that employment in Humboldt County will be down significantly by 1975. It has been argued that tourism would more than compensate for the lower employment in logging. But not if the trees that the tourists come to see are gone. Why can't young and mature trees be harvested at a reasonable rate, the old trees saved, and both tourism and logging flourish?

The question posed earlier has been answered. Redwood growth and survival can be modeled, using matrix methods in a new context. Meaningful conclusions may be drawn. And the results are sufficiently tantalizing to inspire further research.
Vitamin D Metabolism: The Role of Kidney Tissue
Authors: Gray R. , Boyle I. , Deluca H. F.
Published: October 2006

The appearance of a polar metabolite of 25-hydroxycholecalciferol has been studied in the intestinal mucosas of nephrectomized rats and rats which have been made uremic by ureter ligation. In confirmation of previous work by Fraser and Kodicek, it was found that nephrectomy prevents the appearance of this metabolite in the intestine. On the other hand, equivalent amounts of the metabolite were found in uremic rats and in sham-operated controls, showing that the production of this metabolite is independent of the uremic state of the animals. In addition, it was shown that the metabolite produced in vitro by kidney homogenates is identical to that found in vivo in the intestine.
Thyrotropin-Releasing Hormone: Biosynthesis by Rat Hypothalamic Fragments in vitro
Authors: Mitnick Maryann , Reichlin Seymour
Published: October 2006

Biosynthesis of thyrotropin-releasing hormone (L-pyroglutamyl-L-histidyl-L-proline amide) in vitro was studied. Rat hypothalamic fragments were incubated in Krebs-Ringer bicarbonate buffer that contained either
14
C-labeled proline, histidine, or glutamic acid (the three probable precursor amino acids) and for control purposes each of 16 other naturally occurring amino acids. A number of labeled peptides were synthesized. With the use of synthetic thyrotropin-releasing hormone, detected by the Pauly reagent or with
125
I-labeled thyrotropin-releasing hormone as a marker, thin-layer chromatograms, paper electrophoresis, and carboxymethyl cellulose ion exchange chromatography revealed that only proline, histidine, and glutamic acid were consistently incorporated into peptides associated with the thyrotropin-releasing hormone region. This synthesizing activity was found in stalk median eminence, ventral hypothalamus. and dorsal hypothalamus but not in neural lobe or cerebral cortex. Because the biosynthetic peptide has identical properties with L-pyroglutamyl-L-histidyl-L-proline amide, it is probable that rat thyrotropin-releasing hormone is similar or identical to both bovine and porcine thyrotropin-releasing hormone and that the native material is present in the pyroglutamyl form in tissues.
Petroleum: Tar Quantities Floating in the Northwestern Atlantic Taken with a New Quantitative Neuston Net
Authors: Morris Byron F.
Published: October 2006

The neuston net has been modified to obtain quantitative samples of surface zooplankton. Petroleum lumps are commonly taken with these nets, and quantities of tar up to almost 0.1 gram (wet weight) per cubic meter of filtered surface water have been taken in the northwestern Atlantic. This information is used to estimate the quantity of tar lumps present in the North Atlantic and to indicate the probable limits of the degree of existing oil pollution in this region. It is suggested that previous estimates of ocean oil pollution may be too low.
Electroshock Effects on Brain Protein Synthesis: Relation to Brain Seizures and Retrograde Amnesia
Authors: Cotman Carl W. , Banker Gary , Zornetzer Steven F. , McGaugh James L.
Published: October 2006

The effects of electroshock on brain seizure activity and brain protein synthesis were studied in male mice. A significant but short-lasting inhibition of brain protein synthesis and an increase in the amount of free leucine were produced by electroshock at intensities above the brain seizure threshold. Electroshock at intensities below the brain seizure threshold did not affect brain protein synthesis.
Isolation of Mycoplasmatales Viruses and Characterization of MVL1, MVL52, and MVG51
Authors: Liss Alan , Maniloff Jack
Published: October 2006

Eleven Mycoplasmatales viruses are now known. Burst size, burst time, sensitivity to ultraviolet and the host range of three viruses that were studied are different. However, all three are naked, rod-shaped particles of similar size. Plaque morphology and the isolation of immune cells suggest that both virulent and nonvirulent infections are possible.
Amino Acid Composition of Proteins as a Product of Molecular Evolution
Authors: Ohta Tomoko , Kimura Motoo
Published: October 2006

The average amino acid composition of proteins is determined by the genetic code and by random base changes in evolution. Small but significant deviations from expected composition can be explained by selective constraint on amino acid substitutions. In particular, the deficiency of arginine in proteins has been caused by constraint, during evolution, on fixation of mutations substituting arginine for other amino acids.
Madagascar's Paleoposition: New Data from the Mozambique Channel
Authors: Heirtzler J. R. , Burroughs R. H.
Published: October 2006

The main paleopositions that have been proposed for Madagascar are examined after a recent geological and geophysical survey in the Mozambique Channel. Results from that survey show a north-south ridgelike feature and favor the theory that Madagascar fitted against Somalia rather than against Mozambique to the west.
Phenothiazine Effects on Auditory Signal Detection in Paranoid and Nonparanoid Schizophrenics
Authors: Rappaport M. , Silverman J. , Hopkins H. K. , Hall K.
Published: October 2006

The differential effects of phenothiazine medication on auditory signal detection performance were compared in two types of schizophrenic subjects and in normal subjects. With increasing phenothiazine dosage a decrease in efficiency of signal detection performance occurred among nonparanoid schizophrenics and an increase in efficiency occurred among paranoid schizophrenics. These and related findings were interpreted in terms of differences in neuropsychological response and information processing characteristics in the two types of schizophrenics. The primary deficit in information processing in nonparanoid schizophrenics may be related primarily to their hypersensitivity to sensory stimuli, whereas in paranoids it may be related primarily to their impaired focusing of attention. Phenothiazines appear to decrease sensitivity to stimuli in nonparanoids but increase the ability to focus attention in paranoids. The possibility of treatment regimens which take into account the differential effects of phenothiazine medication was suggested.
Melanin Pigmentation: An in vivo Model for Studies of Melanosome Kinetics within Keratinocytes
Authors: Wolff Klaus , Konrad Klaus
Published: October 2006

The phagocytosis of latex beads by epidermal cells is proposed as a model for studies on melanosome kinetics within the epidermis. Large latex beads (0.8 micrometer) are ingested singly, whereas small beads (0.1 micrometer) are taken up in groups, results showing that the uptake mechanism depends on the size of the individual particles. This size-dependency may explain the different distribution patterns of melanosomes and thus the differences of skin color in the Caucasoid and Negroid races.
Auditory Cortex of Squirrel Monkey: Response Patterns of Single Cells to Species-Specific Vocalizations
Authors: Wollberg Zvi , Newman John D.
Published: October 2006

Most of the neurons tested in the superior temporal cortex of awake squirrel monkeys responded to recorded species-specific vocalizations. Some cells responded with temporally complex patterns to many vocalizations. Other cells responded with simpler patterns to only one call. Most cells lay between these two extremes. On-line deletion of parts of a vocalization revealed the role of temporal interactions in determining the nature of some responses.
Rare Gas Record in the Largest Apollo 15 Rock
Authors: Marti K. , Lightner B. D.
Published: October 2006

The spallation krypton data from rock chip 15555,23 indicate a well-shielded location during most of the time during which the rock was exposed to cosmic rays. A krypton-krypton exposure age of 81
+17
-7
× 10
6
years is calculated, and the gas retention ages are estimated. No evidence for the presence of products from plutonium-244 or iodine-129 was found.
Air Containing Nitrogen-15 Ammonia: Foliar Absorption by Corn Seedlings
Authors: Porter Lynn K. , Viets Frank G. , Hutchinson Gordon L.
Published: October 2006

Thirty-day-old corn seedlings, grown in the greenhouse with different concentrations of supplemental nitrate nitrogen, were moved to a constant-temperature growth chamber and sealed in a 560-liter tent made of polyvinyl chloride. The plants were exposed to air containing ammonia labeled with nitrogen-15 (1, 10, and 20 parts per million) for 24 hours and then harvested. The nitrogen-15 content of the tops and roots showed that at 1 part per million 43 percent of the ammonia was absorbed, whereas at 10 and 20 parts per million, 30 percent of the ammonia was absorbed. The results demonstrate that growing plants may be a natural sink for atmospheric ammonia.
Photosynthetic Adaptation to High Temperatures: A Field Study in Death Valley, California
Authors: Björkman Olle , Pearcy Robert W. , Harrison A. Tyrone , Mooney Harold
Published: October 2006

The photosynthesis of
Tidestromia oblongifolia
(Amranthaceae) is remarkably well adapted to operate at the very high summer temperatures of the native habitat on the floor of Death Valley. The photosynthetic rate was very high and reached its daily maximum when the light intensity reached its noon maximum at the high leaf temperatures of 46° to 50°C which occurred at this time. At the intensity of noon sunlight the rate decreased markedly when the leaf temperature was experimentally reduced to below 44°C. The optimum rate occurred at 47°C. At this temperature the photosynthetic rate was essentially directly proportional to light intensity up to full sunlight.
Isolated Adrenal Cells: Adrenocorticotropic Hormone, Calcium, Steroidogenesis, and Cyclic Adenosine Monophosphate
Authors: Sayers George , Beall Robert J. , Seelig Steven
Published: October 2006

Corticosterone production by isolated adrenal cells in response to adrenocorticotropic hormone is reduced when the cells are incubated in a medium that contains no calcium. This reduction is associated with an equal reduction of accumulation of cyclic adenosine monophosphate. Production of corticosterone and accumulation of cyclic adenosine monophosphate are increased when the calcium concentration in the medium is increased (from zero to 7.65 millimolar). This is in contrast to the situation in "subcellular membrane fragments" of adrenal tissue where high calcium in the medium (> 1.0 millimolar) inhibits cyclic adenosine monophosphate accumulation. We propose that adenyl cyclase in the intact plasma membrane is located in a compartment wherein calcium concentration is low and remains unaffected by the concentration of calcium in the extracellular space. It is proposed that, as the concentration of calcium in the incubation medium is increased from zero to 7.65 millimolar, the strength of the signal generated by the interaction of adrenocorticotropic hormone with its receptor and transmitted to the adenyl cyclase compartment is proportionately increased.
Cribriform Degeneration (
cri
): A New Recessive Neurological Mutation in the Mouse
Authors: Green Margaret C. , Sidman Richard L. , Pivetta Omar H.
Published: October 2006

The mutation cribriform degeneration (
cri
) occurred in the DBA/2J strain; it is in linkage group VIII, 31 recombination units from b. Homozygotes show severe vacuolar degeneration in white and gray matter of the spinal cord and brainstem, normocytic anemia at birth which decreases in severity with age, and abnormalities of electrolyte distribution.
Polymers: Synthesis and Characterization of Extremely High-Molecular-Weight Polystyrene
Authors: McIntyre D. , Fetters L. J. , Slagowski E.
Published: October 2006

Polystyrenes with molecular weights up to 44 × 10
6
grams per mole have been characterized by light-scattering and equilibrium ultracentrifugation methods. The Mark-Houwink equation, which relates the molecular weight and the intrinsic viscosity of flexible polymers, can be used only if the measurements are made in a theta solvent at the theta temperature.
Specific Triiodothyronine Binding Sites in the Anterior Pituitary of the Rat
Authors: Schadlow Alan R. , Surks Martin I. , Schwartz Harold L. , Oppenheimer Jack H.
Published: October 2006

Studies with L-[
125
I]triiodothyronine and L-[
125
I]thyroxine, and with equilibrium dialysis of plasma proteins indicate that rat pituitary binds L-triiodothyronine 9.8 times as strongly as it does L-thyroxine. Injection of even small doses of nonradioactive L-triiodothyronine reduces the pituitary/plasma ratio of radioactive L-triiodothyronine, an indication of the existence of pituitary binding sites with a limited capacity for L-triiodothyronine. Limited capacity binding sites for L-thyroxine could not be demonstrated.
Adenosine 3′,5′-Monophosphate Is Localized in Cerebellar Neurons: Immunofluorescence Evidence
Authors: Bloom F. E. , Hoffer B. J. , Battenberg E. R. , Siggins G. R. , Steiner A. L. , Parker C. W. , Wedner H. J.
Published: October 2006

Adenosine 3′,5′-monophosphate is localized in specific cerebellar neurons, as shown by fluorescence immunocytochemistry with a specific rabbit immunoglobulin. Positive staining is exhibited by Purkinje neurons and granule cells. The increase in concentration of cyclic adenosine monophosphate in the cerebellum, which is known to follow decapitation, is represented by greatly increased fluorescence of Purkinje neurons only. These immunofluorescence data provide the first evidence for localization of cyclic adenosine monophosphate in specific neurons and may permit further exploration into the role of this cyclic nucleotide in neuronal function.
Visual Sensations Induced by Relativistic Nitrogen Nuclei
Authors: McNulty P. J. , Pease V. P. , Pinsky L. S. , Bond V. P. , Schimmerling W. , Vosburgh K. G.
Published: October 2006

The ability of the human eye to detect nitrogen nuclei that enter the retina at speeds just above the Cerenkov threshold has been confirmed in an experiment at the Princeton Particle Accelerator. A system for beam transport and subject alignment delivered individual nitrogen nuclei onto a spot 3 millimeters in diameter on the retina at a visual angle of 7 degrees on the temporal side of the fovea. The beam particles entered the retina within 25 degrees of normal and induced visual sensations that had the appearance of streaks for three out of four subjects.
Spinel Troctolite and Anorthosite in Apollo 16 Samples
Authors: Prinz Martin , Dowty Eric , Keil Klaus , Bunch T. E.
Published: October 2006

A spinel troctolite and an anorthosite from the Apollo 16 landing site represent contrasting types of "primitive" lunar cumulates. The two rock types probably formed from the same parent magma type, a high-alumina magnesian basalt, with the troctolite forming earlier by crystal settling, and the anorthosite later, possibly by flotation.
Isolation of Aleutian Mink Disease Virus by Affinity Chromatography
Authors: Kenyon A. J. , Gander J. E. , Lopez C. , Good R. A.
Published: October 2006

Affinity chromatography was used to isolate the Aleutian disease virus of mink. Dissociation of the immunoadsorbent-virus complex with 0.75 molar sodium chloride and then with a glycine-hydrochloride gradient released infective particles resembling picornaviruses. The elution profile suggests that two different types of virus-antibody complexes are formed, one dissociated by sodium chloride and another that requires glycine-hydrochloride in addition to sodium chloride for release of virus.
Magnetic Transitions Observed in Sulfide Minerals at Elevated Pressures and Their Geophysical Significance
Authors: Vaughan David J. , Tossell John A.
Published: October 2006

The magnetic behavior of iron in chalcopyrite (CuFeS
2
) and pyrrhotite (Fe
7
S
8
) in the pressure range from 1 atmosphere to 20 kilobars has been studied by Mössbauer spectroscopy. Both chalcopyrite and pyrrhotite exhibit transitions from magnetically ordered to disordered states over the range from 5 to 16 kilobars. Both transitions, particularly the loss of ferrimagnetism in pyrrhotite, have geophysical consequences.
Dopaminergic and Noradrenergic Substrates of Positive Reinforcement: Differential Effects of
d
- and
l
-Amphetamine
Authors: Phillips Anthony G. , Fibiger Hans C.
Published: October 2006

Intracranial self-stimulation was elicited from electrodes located in either the lateral hypothalamus or substantia nigra of the rat. Facilitatory effects of
d-
and
l-
isomers of amphetamine on self-stimulation were assessed. The
d-
isomer was seven to ten times more effective than the
l-
isomer at the hypothalamic placement, whereas the two isomers were equipotent for substantia nigra electrodes. These data support the hypothesis that both dopaminergic and noradrenergic systems subserve positive reinforcement.
Amyotrophic Lateral Sclerosis: Effect of Serum on Anterior Horn Cells in Tissue Culture
Authors: Wolfgram Frederick , Myers Lawrence
Published: October 2006

A high proportion of diluted serums of patients with amyotrophic lateral sclerosis were toxic to the anterior horn cells of the mouse in tissue culture. This is not a general cytotoxicity, since apparently only the neurons were killed. Serums from other degenerative neurological diseases were inactive.
Cyclic Adenosine Monophosphate and Hypertension in Rats
Authors: Amer M. Samir
Published: October 2006

Aortas from spontaneously hypertensive and stress hypertensive rats contained significantly lower intracellular concentrations of cyclic adenosine monophosphate than did their respective controls. Adenylate cyclase activity was normal but was less responsive to stimulation, while phosphodiesterase activity (especially the low Michaelis-Menten constant form) was significantly elevated. Human aortas contained two forms of phosphodiesterase that were similar to those in rat aortas.
Central Norepinephrine Metabolism in Affective Illness: MHPG in the Cerebrospinal Fluid
Authors: Post Robert M. , Gordon Edna K. , Goodwin Frederick K. , Bunney William E.
Published: October 2006

Concentrations of the norepinephrine metabolite 3-methoxy-4-hydroxyphenyl glycol in cerebrospinal fluid were measured by a gas chromatographic method in 34 patients with affective illness and in 44 controls. Concentrations of this metabolite in spinal fluid were significantly lower in depressed patients than in controls or manic patients. These low values may occur secondary to depressive phenomena such as reduced psychomotor activity, or they may reflect a primary change in norepinephrine metabolism in depressive illness.
Activation of Lordotic Responding in Female Rats by Suppression of Serotonergic Activity
Authors: Zemlan Frank P. , Ward Ingeborg L. , Crowley William R. , Margules D. L.
Published: October 2006

After systemic administration of several serotonergic antagonists, female rats that had been ovariectomized, adrenalectomized, and estrogen-primed showed lordotic responding. Lordosis could also be elicited after direct placement of serotonergic receptor blockers into hypothalamic sites known to contain serotonergic terminals. None of the treatments activated the soliciting component of the estrous behavior pattern of the female rat. It is postulated that the hypothalamus contains serotonergic terminals which suppress lordotic responding.
Solar Magnetic Sector Structure: Relation to Circulation of the Earth's Atmosphere
Authors: Wilcox John M. , Scherrer Philip H. , Svalgaard Leif , Roberts Walter Orr , Olson Roger H.
Published: October 2006

The solar magnetic sector structure appears to be related to the average area of high positive vorticity centers (low-pressure troughs) observed during winter in the Northern Hemisphere at the 300-millibar level. The average area of high vorticity decreases (low-pressure troughs become less intense) during a few days near the times at which sector boundaries are carried past the earth by the solar wind. The amplitude of the effect is about 10 percent.
Periodic Insolation Variations on Mars
Authors: Murray Bruce C. , Ward William R. , Yeung Sze C.
Published: October 2006

Previously unrecognized insolation variations on Mars are a consequence of periodic variations in eccentricity, first established by the theory of Brouwer and Van Woerkom (1950). Such annual insolation variations, characterized by both 95,000-year and 2,000,000-year periodicities, may actually be recorded in newly discovered layered deposits in the polar regions of Mars. An additional north-south variation in seasonal insolation, but not average annual insolation, exists with 51,000-year and 2,000,000-year periodicities.
Deep-Sea Microorganisms: In situ Response to Nutrient Enrichment
Authors: Jannasch Holger W. , Wirsen Carl O.
Published: October 2006

After inoculation of sterile organic materials on the deep-sea floor and in situ incubation for 1 year, relatively minute rates of microbial transformation were recorded. This extremely slow conversion rate, as well as the type and quantity of organic matter normally reaching the ocean floor, appear to characterize microbial life in the deep sea.
Phosphoribosylpyrophosphate Synthetase Is Elevated in Fibroblasts from Patients with the Lesch-Nyhan Syndrome
Authors: Martin David W. , Maler Bonnie A.
Published: October 2006

In subconfluent cultures of fibroblasts from patients with complete or partial deficiencies of hypoxanthine-guanine phosphoribosyltransferase, phosphoribosylpyrophosphate synthetase activity is elevated. The abnormally high catalytic activity of the synthetase appears to account for the overproduction of purines by the cultured mutant cells and presumably for that by the patients.