bluuebunny/crossref_metadata_2025 huggingface dataset:
A Requirement for the Intercellular Messenger Nitric Oxide in Long-Term Potentiation
Authors: Schuman Erin M. , Madison Daniel V.
Published: October 2006

Long-term potentiation (LTP) of synaptic transmission is a widely studied model of neuronal plasticity. The induction of LTP is known to require processes in the postsynaptic neuron, while experimental evidence suggests that the expression of LTP may occur in the presynaptic terminal. This has led to speculation that a retrograde messenger travels from the post- to the presynaptic cell during induction of LTP. Extracellular application or postsynaptic injection of two inhibitors of nitric oxide synthase,
N
-nitro-L-arginine or
N
G
-methyl-L-arginine, blocks LTP. Extracellular application of hemoglobin, which binds nitric oxide, also attenuates LTP. These findings suggest that nitric oxide liberated from postsynaptic neurons may travel back to presynaptic terminals to cause LTP expression.
Refined Structure of Charybdotoxin: Common Motifs in Scorpion Toxins and Insect Defensins
Authors: Bontems Francois , Roumestand Christian , Gilquin Bernard , Ménez André , Toma Flavio
Published: October 2006

Conflicting three-dimensional structures of charybdotoxin (Chtx), a blocker of K+channels, have been previously reported. A high-resolution model depicting the tertiary structure of Chtx has been obtained by DIANA and X-PLOR calculations from new proton nuclear magnetic resonance (NMR) data. The protein possesses a small triple-stranded antiparallel β sheet linked to a short helix by two disulfides and to an extended fragment by one disulfide, respectively. This motif also exists in all known structures of scorpion toxins, irrespective of their size, sequence, and function. Strikingly, antibacterial insect defensins also adopt this folding pattern.
Chloride Conductance Expressed by ΔF508 and Other Mutant CFTRs In
Xenopus
Oocytes
Authors: Drumm Mitchell L. , Wilkinson Daniel J. , Smit Lisa S. , Worrell Roger T. , Strong Theresa V. , Frizzell Raymond A. , Dawson David C. , Collins Francis S.
Published: October 2006

The cystic fibrosis transmembrane conductance regulator (CFTR) is associated with expression of a chloride conductance that is defective in cystic fibrosis (CF).
Xenopus
oocytes injected with RNA coding for CFTR that contained mutations in the first nucleotide binding fold (NBF1) expressed chloride currents in response to raising adenosine 3′,5′-monophosphate (cAMP) with forskolin and 3-isobutyl-1-methylxanthine (IBMX). The mutant CFTRs were less sensitive than wild-type CFTR to this activating stimulus, and the reduction in sensitivity correlated with the severity of cystic fibrosis in patients carrying the corresponding mutations. This demonstration provides the basis for detailed analyses of NBF1 function and suggests potential pharmacologic treatments for cystic fibrosis.
How Does the Striate Cortex Begin the Reconstruction of the Visual World?
Authors: Pollen Daniel A. , Lee Jame R. , Taylor Joseph H.
Published: October 2006

The striate cortex transforms the topographic representation of visual space in the lateral geniculate body into a Fourier transform or frequency representation at the complex cell level via the intermediary simple cell stage of "strip integration." Each of these three stages contains essentially the same amount of information, which expresses a conservation of information principle; however, the form of the information is changed. In the transform domain, invariant descriptions of visual objects can be derived to serve as the basic sets required for pattern recognition and memory. We believe that our experimental and theoretical findings are fundamental for understanding the functional organization of the striate cortex.
Ethanol Preference in the Rat as a Function of Photoperiod
Authors: Geller Irving
Published: October 2006

Ethanol-drinking was induced in laboratory rats that were maintained in total darkness. The established preference for ethanol was not reversed under conditions of constant illumination although a decrease in ethanol intake occurred. Administration of melatonin to rats maintained under "normal" photoperiods (9 hours of darkness during a 24-hour day) also induced ethanol-drinking.
Radiohalos: Some Unique Lead Isotope Ratios and Unknown Alpha Radioactivity
Authors: Gentry Robert V.
Published: October 2006

Previously unreported lead isotope ratios, that is, values for the lead-206/lead-207 ratio ranging from about 20 to 60, primarily radiogenic in origin but unsupported by uranium decay, have been determined in the inclusions of certain polonium halos by means of ion microprobe techniques. Evidence for radiogenic lead-208 unsupported by thorium decay may also be inferred from the existence of a composite polonium halo type with rings from the radioactive precursors of lead-208. Several new dwarf halo sizes seem to indicate the existence of unknown, very low-energy alpha-emitters. Furthermore, the three-ring "X halo" also provides evidence for an unknown series of genetically related alpha-emitters with energies in the range from 3 to 7 million electron volts.
Clustering of Sulfur Dioxide and Water Vapor about Oxonium and Nitric Oxide Ions
Authors: Castleman A. W. , Tang I. N. , Munkelwitz H. R.
Published: October 2006

The mobilities of ions produced in electrical discharges in the presence of trace quantities of water vapor and sulfur dioxide are generally lower than those expected for simple ions. Mass spectrometric identification reveals that species composed of water vapor and sulfur dioxide molecules clustering about common atmospheric ions are formed under these conditions. The identification of these clusters provides an explanation for the effect of trace gases on the mobilities of ions.
Microwave Absorption by Normal and Tumor Cells
Authors: Webb S. J. , Booth A. D.
Published: October 2006

Energy levels exist in mammalian cells which result in the absorption of microwaves between 66 and 76 gigahertz. Many of these energy levels occur when water molecules associate with the various chemical groups of macromolecules. The absorption spectra of cells between 66 and 76 gigahertz, therefore, is determined by the structure of in vivo water lattices, and these seem to reflect indirectly the structural makeup of macromolecules or macromolecular complexes. Tumor cells absorb 66-, 68-, and 70-gigahertz microwaves less strongly and 69-, 72-, and 75-gigahertz microwaves more strongly than normal cells. These differences in the strength of attenuation at each frequency suggest that either the ratio of RNA to DNA or the relative number of certain types of chemical groups in tumor cells is different from that in normal cells.
Inorganic Particles in Cigars and Cigar Smoke
Authors: Langer Arthur M. , Mackler Anne D. , Rubin Ivan , Hammond E. Cuyler , Selikoff Irving J.
Published: October 2006

A number of crystalline and optically isotopic inorganic materials are used in the manufacture of reconstituted tobacco sheets. These sheets, used primarily in inexpensive cigars, often contain diatomaceous earth, which exists in part in the silica mineral form cristobalite, a known fibrogen. Diatom fragments with this crystalline form have been observed in the main smoke stream of cigars made with these tobacco sheets.
Particle Formation during Water-Vapor Photolysis
Authors: Clark Ian D. , Noxon John F.
Published: October 2006

Micrometer-sized particles have been produced by the photolysis of water vapor at wavelengths between 1500 and 1700 angstroms. Although the composition of the particles was not determined, the rate of particle production is consistent with the efficient conversion of water photolysis products to particulate matter. Such a process may be of importance in planetary atmospheres.
Strontium Induced Rickets: Metabolic Basis
Authors: Omdahl J. L. , DeLuca H. F.
Published: October 2006

Dietary strontium inhibits both the synthesis of 1,25-dihydroxycholecalciferol and intestinal calcium absorption in vitamin D
3
-repleted chicks. 1,25-Dihydroxycholecalciferol restores calcium absorption to normal, while 25-hydroxycholecalciferol is without effect in the strontium-fed chick. It is suggested that strontium induces rickets by blocking the biosynthesis of 1,25-dihydroxycholecalciferol, the metabolically active form of vitamin D in the intestine.
Unstirred Water Layers in Intestine: Rate Determinant of Fatty Acid Absorption from Micellar Solutions
Authors: Wilson Frederick A. , Sallee Verney L. , Dietschy John M.
Published: October 2006

Bile acid and fatty acid uptake from micellar solutions by intestinal cells fails to reflect the incremental free energy changes expected for permeation that is rate limited by cell membranes. However, altering the size of the diffusing particle or the thickness of the unstirred water layer does change uptake. These observations show that the unstirred water layer is rate limiting for intestinal absorption of lipids from micellar solutions.
Raman Spectrum of a Transfer RNA
Authors: Tsuboi Masamichi , Takahashi Seizo , Muraishi Shuichi , Kajiura Teruo , Nishimura Susumu
Published: October 2006

Raman spectrum of purified formylmethionine transfer RNA from
Escherichia coli
has been observed in its aqueous solution. In the 1800 to 200 cm
-1
range, about 30 Raman lines are found, each of which can be assigned to one of the constituent nucleotide residues. From the positions and intensities of the lines, information on the intramolecular environments of these base residues can be obtained.
Proportional Release of Norepinephrine and Dopamine-β-Hydroxylase from Sympathetic Nerves
Authors: Weinshilboum Richard M. , Thoa Nguyen B. , Johnson David G. , Kopin Irwin J. , Axelrod Julius
Published: October 2006

Dopamine-β-hydroxylase (DBH), the enzyme that catalyzes the conversion of dopamine to norepinephrine, is localized in the vesicles containing catecholamine in sympathetic nerves. This enzyme is released with norepinephrine when the nerves to the guinea pig vas deferens are stimulated in vitro, and the amount of enzyme discharged increases as the length of stimulation periods increases. The amount of DBH released is proportional to the amount of norepinephrine released, and the ratio of norepinephrine to DBH discharged into the incubation medium is similar to that in the soluble portion of the contents of the synaptic vesicles from the vas deferens. These data are compatible with the release of the neurotransmitter norepinephrine and DBH from sympathetic nerves by a process of exocytosis.
Stage 4 Sleep: Influence of Time Course Variables
Authors: Webb W. B. , Agnew H. W.
Published: October 2006

Age, length of prior wakefulness, length of time asleep, and a circadian influence all affect stage 4 sleep. The amount of stage 4 sleep decreases as subject's age increases and as time asleep increases. Longer periods of wakefulness before sleep result in greater amounts of stage 4 sleep in the first 3 hours of sleep. Sleep periods that begin at times other than the regular onset time tend to produce less stage 4 sleep; this decrease suggests a circadian effect.
Long-Term Habituation of a Defensive Withdrawal Reflex in
Aplysia
Authors: Carew Thomas J. , Pinsker Harold M. , Kandel Eric R.
Published: October 2006

A tactile stimulus to the siphon of
Aplysia
produces a defensive withdrawal reflex consisting of contraction of the siphon, the gill, and the mantle shelf. We studied long-term habituation of this reflex using two types of preparations, one focusing on the siphon component and the other on the gill component of the reflex. Siphon withdrawal, studied in unrestrained animals, showed marked habituation within a single ten-trial training session. Five daily training sessions produced habituaton that built up across days and lasted for at least 3 weeks. Furthermore, spaced training produced significantly longer lasting habituation than massed training. Gill withdrawal, studied in a restrained animal, also showed long-term retention of habituation. Since the neural circuitry of gill withdrawal is relatively well understood, it may be possible to study the cellular mechanisms underlying a long-term behavioral modification.
Ultrathin Amorphous Coatings on Lunar Dust Grains
Authors: Bibring J. P. , Duraud J. P. , Durrieu L. , Jouret C. , Maurette M. , Meunier R.
Published: October 2006

Ultrathin amorphous coatings have been observed by high-voltage electron microscopy on micrometer-sized dust grains from the Apollo 11, Apollo 12, Apollo 14, and Luna 16 missions. Calibration experiments show that these coatings result from an "ancient" implantation of solar wind ions in the grains. This phenomenon has interdisciplinary applications concerning the past activity of the sun, the lunar albedo, the ancient lunar atmosphere and magnetic field, the carbon content of lunar soils, and lunar dynamic processes.
Peripheral Thermoregulation: Foot Temperature in Two Arctic Canines
Authors: Henshaw Robert E. , Underwood Larry S. , Casey Timothy M.
Published: October 2006

Arctic foxes and gray wolves maintain their foot temperature just above the tissue freezing point (about -1°C) when standing on extremely cold snow, or when the foot is immersed in a -35°C bath in the laboratory. Proportional thermoregulation stabilized the subcutaneous temperature of the foot pad to a precision of ± 0.7°C (largest deviations). Selective shunting of blood-borne body heat through a cutaneous vascular plexus in the foot pad accounted for more than 99 percent of measured heat loss from the pad surface. Maximum energetic efficiency is achieved because the unit of heat exchange is located in the pad surface which contacts the cold substrate rather than throughout the pad.
Uplifted Trench Sediments: Southwestern Alaska-Bering Shelf Edge
Authors: Moore J. Casey
Published: October 2006

Cretaceous turbidites are discontinuously exposed for 1700 kilometers along the continental margin of southwestern Alaska and the Bering shelf edge. Paleocurrent flow parallel to exposure patterns and the abundance of primary andesitic volcanic detritus suggest deposition in an oceanic trench. This Cretaceous trench bordering the continent was superseded by the Aleutian arc-trench in the earliest Tertiary.
Intravascular Degranulation of Neutrophils: An Important Factor in Inflammation?
Authors: Schumacher H. Ralph , Agudelo Carlos A.
Published: October 2006

Polymorphonuclear leukocytes are degranulated in the lumens of vessels in synovial membrane in humans with various types of inflammatory arthritis and in dogs with synovitis induced by urate crystals. This degranulation, accompanied by the release of lysosomal enzymes and vasoactive materials, may be an important part of the mechanism resulting in vascular injury.
The Hill Plot and the Energy of Interaction in Hemoglobin
Authors: Saroff H. A. , Minton Allen P.
Published: October 2006

The Hill plot does not independently yield the average free energy of interaction per binding site, as has been proposed by Wyman, but rather the difference between the free energies of interaction on binding the first and last ligands. It is shown that additional data (or assumptions) and a model for cooperative behavior are required to obtain the average free energy of interaction.
Nucleotide Sequence of a Lysine Transfer Ribonucleic Acid from Bakers' Yeast
Authors: Madison James T. , Boguslawski Sophia J. , Teetor Gertrud H.
Published: October 2006

The nucleotide sequence of one of the two major lysine transfer RNA's from bakers' yeast has been determined. Its structure is compared to that of a lysine tRNA from a haploid yeast. A total of 21 nucleotides differ in the two molecules. Only the T-ψ-C-G (thymidine-pseudouridine-cytidine-guanosine) loop and its supporting stem are identical.
Mutations Induced in
Tradescantia
by Small Doses of X-rays and Neutrons: Analysis of Dose-Response Curves
Authors: Sparrow A. H. , Underbrink A. G. , Rossi H. H.
Published: October 2006

Dose-response curves for pink somatic mutations in
Tradescantia
stamen hairs were analyzed after neutron and x-ray irradiation with doses ranging from a fraction of a rad to the region of saturation. The dose-effect relation for neutrons indicates a linear dependence from 0.01 to 8 rads; between 0.25 and 5 rads a linear dependence is indicated for x-rays also. As a consequence the relative biological effectiveness reaches a constant value (about 50) at low doses. The observations are in good agreement with the predictions of the theory of dual radiation action and support its interpretation of the effects of radiation on higher organisms. The doubling dose of x-rays was found to be nearly 1 rad.
Relic Pleistocene Permafrost, Western Arctic, Canada
Authors: Mackay J. Ross , Rampton V. N. , Fyles J. G.
Published: October 2006

Icy layers and interbedded frozen sediments along the Arctic Coastal Plain of northwestern Canada have been subjected to glacial deformation. Radiocarbon dates indicate that the deformation took place more than 40,000 years ago.
Synaptic Vesicles: Selective Depletion in Crayfish Excitatory and Inhibitory Axons
Authors: Atwood Harold L. , Lang Fred , Morin Walter A.
Published: October 2006

Stimulation of the excitatory axon of the opener muscle of the crayfish in the presence of the metabolic inhibitor 2,4-dinitrophenol leads to depletion of synaptic vesicles in nerve terminals containing round vesicles. Stimulation of the inhibitory axon under these conditions produces depletion of vesicles in other nerve terminals containing more elongate synaptic vesicles. The experiments show that terminals with round synaptic vesicles are excitatory and that terminals with elongate synaptic vesicles are inhibitory. Replenishment of synaptic vesicles appears to require metabolic energy.
Acceleration of Argon Ions to 1.17 × 10
10
Electron Volts
Authors: Isaila M. V. , Schimmerling W. , Vosburgh K. G. , White M. G. , Filz R. C. , McNulty P. J.
Published: October 2006

Argon ions were accelerated to 1.17 × 10
10
electron volts in the Princeton Particle Accelerator. The synchrotron was tuned by use of a neon beam with a charge-to-mass ratio equal to that of the argon ions. The fully accelerated argon ions were detected by the observation of etched tracks in cellulose nitrate sheets and also by the use of scintillation counters. Predictions of the range and of the characteristics of argon tracks in plastics were confirmed.
Insulin Insensitivity of Large Fat Cells
Authors: Livingston James N. , Cuatrecasas Pedro , Lockwood Dean H.
Published: October 2006

Large insulin-insensitive adipocytes from adult rats have normal binding capacities and affinities for insulin. Diminished insulin-like responses to spermine and reduced rates of glucose oxidation are also evident in these cells. The results indicate that the defect responsible for this insulin-resistant state exists in a step subsequent to insulin binding, possibly in transmission of the insulin-receptor "signal" since insensitivity occurs under conditions where glucose transport and oxidative processes are not apparently impaired.
Calcium Oxalate Crystals in the Aragonite-Producing Green Alga
Penicillus
and Related Genera
Authors: Friedmann E. Imre , Roth William C. , Turner James B. , McEwen Ronald S.
Published: October 2006

Calcium oxalate crystals occur in the marine green algae
Penicillus
,
Rhipocephalus
, and
Udotea
, known as producers of sedimentary aragonite needles. In contrast to the externally deposited aragonite crystals which are generally < 15 micrometers long, the oxalate crystals are larger (up to 150 micrometers) and are located in the vacuolar system of the plant. No calcium oxalate was found in the related but noncalcifying genera
Avrainvillea
and
Cladocephalus
.
Conditioned Approach and Contact Behavior toward Signals for Food or Brain-Stimulation Reinforcement
Authors: Peterson Gail B. , Ackilt James E. , Frommer Gabriel P. , Hearst Eliot S.
Published: October 2006

When presentation of a retractable lever always preceded food delivery, rats licked or gnawed the lever. They also approached but seldom orally contacted a lever signaling brain-stimulation reinforcement; instead, subjects sniffed, pawed, or "explored" the lever. Therefore, a Pavlovian conditioned stimulus evoked directed skeletal responses whose specific form depended on the forthcoming unconditioned stimulus.
Bacteriogenic Sulfur in Air Pollution
Authors: Grey D. C. , Jensen M. L.
Published: October 2006

On a yearly basis, the major source of atmospheric sulfur compounds in and near Salt Lake City, Utah, is industrial. Isotopic studies suggest that the next most important source is bacteriogenic sulfur released by anaerobes from muds. On a seasonal basis, the bacteriogenic source of sulfur compounds may rival the industrial source in importance.
Desulfurization of Coal
Authors: Meyers R. A. , Hamersma J. W. , Land J. S. , Kraft M. L.
Published: October 2006

Coal combustion is the largest single source of sulfur oxide pollution. Treatment of some major representative U.S. coals with aqueous ferric solution removes 40 to 75 percent of the sulfur content through near quantitative oxidation of the pyritic sulfur contained in the coal matrix. Elemental sulfur and iron sulfate are recovered as products of the reaction. Engineering assessment indicates that the system, when fully developed, offers high potential for the economic abatement of sulfur oxide pollution.
Neisseria gonorrhoeae
: Experimental Infection of Laboratory Animals
Authors: Arko Robert J.
Published: October 2006

Experimental
Neisseria gonorrhoeae
infections were established in five species of small laboratory animals (rabbits, guinea pigs, hamsters, mice, and rats) after subcutaneously implanted chambers were inoculated with gonococci. The chamber fluid was easily available for study or culture. A systemic immune response was indicated by hemagglutination assay.
Synthesis of Cysteine from Methionine in Normal Adult Subjects: Effect of Route of Alimentation
Authors: Stegink Lewis D. , Besten Lawrence Den
Published: October 2006

Parenteral alimentation solutions free of cysteine, probably an essential amino acid for premature infants, were administered continuously to eight healthy men through catheters in the superior vena cava and through nasogastric tubes. When the preparation was administered parenterally, the plasma cystine concentration dropped markedly. When feeding was switched to the oral route, the concentration rose immediately, but returned to baseline only when a cystine-containing diet was fed. These studies indicate that the synthesis of cysteine from methionine is limited, even in the adult subject, when cystine-free diets are administered parenterally.
Recognition of Cancer in vivo by Nuclear Magnetic Resonance
Authors: Weisman Irwin D. , Bennett Lawrence H. , Maxwell Louis R. , Woods Mark W. , Burk Dean
Published: October 2006

Pulsed nuclear magnetic resonance has been used to differentiate in vivo between normal mouse tail tissue and a malignant transplanted melanoma, S91, located on the tail. The tumor displayed a nuclear (proton) spin-lattice relaxation time of ∼0.7 second contrasted with the simultaneously measured normal tail tissue relaxation time of ∼0.3 second.
Myelination Inhibition Factor: Dissociation from Induction of Experimental Allergic Encephalomyelitis
Authors: Kies Marian W. , Driscoll Bernard F. , Seil Fredrick J. , Alvord Ellsworth C.
Published: October 2006

Sensitization of guinea pigs with purified myelin basic protein induces experimental allergic encephalomyelitis (EAE) but does not induce a serum factor which inhibits myelin formation in vitro. This factor, induced by some unidentified constituent of whole central nervous system tissue, should not be characterized as a component of "EAE serum."
Retzius Cells: Neuroeffectors Controlling Mucus Release by the Leech
Authors: Lent Charles M.
Published: October 2006

Mucus release from the skin of leeches is under the control of the pair of large Retzius cells in each segmental ganglion. The rate of mucus release increases with the impulse activity of Retzius cells and with the concentration of their putative neurotransmitter, 5-hydroxytryptamine, to which the skin is exposed.
Graft versus Leukemia: Quantification of Adoptive Immunotherapy in Murine Leukemia
Authors: Bortin Mortimer M. , Rimm Alfred A. , Saltzstein Edward C.
Published: October 2006

Quantification of the antileukemic reactivity of transplanted immunocompetent cells from various allogeneic donors was achieved against a long-passage lymphocytic leukemia of AKR mice. Adoptive immunotherapy was the exclusive antileukemic treatment. Cells from DBA/2 donors exhibited maximal antileukemic effect, inactivating up to an estimated 10
7
leukemia cells. The cellular events were interpreted by using a theoretical cytokinetic construct.
Synthesis of Infective Poliovirus in BSC-1 Monkey Cells Enucleated with Cytochalasin B
Authors: Pollack Robert , Goldman Robert
Published: October 2006

BSC-1 monkey kidney cells were enucleated by two cycles of centrifugation in the presence of cytochalasin B. The resulting populations contained 99.5 percent enucleated cells. After infection, newly synthesized poliovirus was recovered from the enucleated populations. Final virus yield per enucleated cell was about one-fifth the yield per infected untreated cell.
Lonar Lake, India: An Impact Crater in Basalt
Authors: Fredriksson K. , Dube A. , Milton D. J. , Balasundaram M. S.
Published: October 2006

Discovery of shock-metamorphosed material establishes the impact origin of Lonar Crater. Coarse breccia with shatter coning and microbreccia with moderately shocked fragments containing maskelynite were found in drill holes through the crater floor. Trenches on the rim yield strongly shocked fragments in which plagioclase has melted and vesiculated, and bombs and spherules of homogeneous rock melt. As the only known terrestrial impact crater in basalt, Lonar Crater provides unique opportunities for comparison with lunar craters. In particular, microbreccias and glass spherules from Lonar Crater have close analogs among the Apollo specimens.
Moroccan Crustal Response to Continental Drift
Authors: Kanes W. H. , Saadi M. , Ehrlich E. , Alem A.
Published: October 2006

The formation and development of a zone of spreading beneath the continental crust resulted in the breakup of Pangea and formation of the Atlantic Ocean. The crust of Morocco bears an extremely complete record of the crustal response to this episode of mantle dynamics. Structural and related depositional patterns indicate that the African margin had stabilized by the Middle Jurassic as a marine carbonate environment; that it was dominated by tensile stresses in the early Mesozoic, resulting in two fault systems paralleling the Atlantic and Mediterranean margins and a basin and range structural-depositional style; and that it was affected by late Paleozoic metamorphism and intrusion. Mesozoic events record the latter portion of African involvement in the spreading episode; late Paleozoic thermal orogenesis might reflect the earlier events in the initiation of the spreading center and its development beneath significant continental crust. In that case, more than 100 million years were required for mantle dynamics to break up Pangea.
Spatial Orientation by Salamanders Using Plane-Polarized Light
Authors: Taylor Douglas H. , Adler Kraig
Published: October 2006

Tiger salamanders (
Ambystoma tigrinum
) can perceive the plane of polarization in linearly polarized light and can learn to use that e-vector direction for spatial orientation in indoor orientation tests.
Vasopressin: Possible Role of Microtubules and Microfilaments in Its Action
Authors: Taylor Ann , Mamelak Mortimer , Reaven Eve , Maffly Roy
Published: October 2006

Colchicine, vinblastine, podophyllotoxin, and cytochalasin B inhibit the action of vasopressin and cyclic adenosine monophosphate on osmotic water movement across the toad bladder. The findings suggest that microtubules, and possibly microfilaments, play a role in the action of vasopressin, perhaps through involvement in the mechanism of release of secretory material from the bladder epithelial cells.
Eelgrass (
Zostera marina
L.) in the Gulf of California: Discovery of Its Nutritional Value by the Seri Indians
Authors: Felger Richard , Moser Mary Beck
Published: October 2006

Zostera marina
occurs in the northern Gulf of California. The grain of eelgrass is harvested in the spring and formed an important part of traditional Seri diet and culture. This is the only known case of a grain from the sea being used as a human food source. Eelgrass has considerable potential as a general food resource for mankind. Its cultivation would not require fresh water, pesticides, or artificial fertilizer.
Chlorinated Urban Water: A Cause of Dialysis-Induced Hemolytic Anemia
Authors: Eaton John W. , Kolpin Charles F. , Swofford Harold S. , Kjellstrand C M. , Jacob Harry S.
Published: October 2006

Unexplained acute hemolytic anemia is sometimes seen in uremic patients undergoing hemodialysis. Chloramines, which are oxidant compounds made up of chlorine and ammonia and are widely used as bactericidal agents in urban water supplies, have been found responsible for two recent epidemics, in dialyzed uremic patients, of acute hemolytic anemia characterized by Heinz bodies. Chloramines produce denaturation of hemoglobin, both by their direct oxidizing capacity and their ability to inhibit red cell reductive (hexose monophosphate shunt) metabolism.
Imprinting: Lasting Effects on Uracil Incorporation into Chick Brain
Authors: Bateson P. P. G. , Rose S. P. R. , Horn G.
Published: October 2006

On the first day after hatching, domestic chicks were trained for 20, 60, 120, or 240 minutes with an imprinting stimulus. On the second day, they were all retrained for 60 minutes. The greater the chicks' experience on the first day, the lower the rate of incorporation of tritiated uracil into macromolecules in the anterior part of the forebrain roof on the second day. Such effects were not found in other brain regions, nor in any brain region of chicks that received similar treatment on the first day but were not retrained on the second.
Lack of Glucagon Response to Hypoglycemia in Diabetes: Evidence for an Intrinsic Pancreatic Alpha Cell Defect
Authors: Gerich John E. , Langlois Maurice , Noacco Claudio , Karam John H. , Forsham Peter H.
Published: October 2006

Despite excessive glucagon responses to infusion of arginine, plasma glucagon did not rise in six juvenile-type diabetics during severe insulin-induced hypoglycemia, whereas glucagon in the controls rose significantly. Thus in diabetics pancreatic alpha cells are insensitive to glucose even in the presence of large amounts of circulating insulin. An intrinsic defect common to both alpha and beta pancreatic cells—failure to recognize (or respond to) plasma glucose fluctuations—may be operative in juvenile diabetes.
Neuromuscular Junction in Myasthenia Gravis: Decreased Acetylcholine Receptors
Authors: Fambrough Douglas M. , Drachman Daniel B. , Satyamurti S.
Published: October 2006

The number of acetylcholine receptors was determined in the neuromuscular junctions of eight patients with typical myasthenia gravis and in five controls, by means of
125
I-labeled α-bungarotoxin binding. The junctional acetylcholine receptors were reduced in the myasthenic muscles as compared with the controls. This reduction in receptors may account for the defect in neuromuscular transmission in myasthenia gravis.
Raman Spectroscopic Evidence for Two Conformations of Uncomplexed Valinomycin in the Solid State
Authors: Rothschild Kenneth J. , Asher Irvin M. , Anastassakis Evangelos , Stanley H. Eugene
Published: October 2006

Raman spectroscopy is applied for the first time to elucidate the different conformations of the carrier transport molecule, valinomycin. Splitting of the ester and amide carbonyl stretch vibrations is observed in the Raman spectrum of crystals of valinomycin grown from both
n
-octane and acetone. These observations support the contention that some ester carbonyl groups are intramolecularly hydrogen bonded. The Raman spectrum of valinomycin grown from
o
-dichlorobenzene does not display this feature.
Venus: Composition and Structure of the Visible Clouds
Authors: Prinn Ronald G.
Published: October 2006

It is proposed that the visible cloud deck on Venus is composed of droplets of sulfuric acid. These are formed by the very rapid photooxidation of carbonyl sulfide in the upper atmosphere. The clouds are best described as an extensive haze since the predicted particulate scale height probably exceeds the gas scale height within the layer. The predicted mixing ratio for water is 10
-6
(lower limit), and for both carbonyl sulfide and sulfur dioxide it is 10
-7
(upper limit); these are in good agreement with observations. Gaps in the layer are not possible unless the planetary scale dynamics produce cloud turnover times of less than a few days. Under these conditions the water mixing ratio could approach 10
-4
and the formation of a thin hydrochloric acid haze at high altitude above the main cloud is possible.
Luteinizing Hormone-Releasing Factor Potentiates Lordosis Behavior in Hypophysectomized Ovariectomized Female Rats
Authors: Pfaff Donald W.
Published: October 2006

Subcutaneous injection of luteinizing hormone-releasing factor (LRF) in estrogen-primed hypophysectomized, ovariectomized female rats facilitates the appearance of the lordosis response. The LRF effect on lordosis was seen 90, 180, and 360 minutes after injection. This effect could help to synchronize the female's mating behavior with the ovulatory discharge of luteinizing hormone.
Flexible System for the Diagnosis of Schizophrenia: Report from the WHO International Pilot Study of Schizophrenia
Authors: Carpenter William T. , Strauss John S. , Bartko John J.
Published: October 2006

Behavioral data on a large patient group were collected by investigators from nine countries in the International Pilot Study of Schizophrenia, sponsored by the World Health Organization. The data on half the group were analyzed to derive a system of 12 signs and symptoms for the identification of schizophrenia, as this disorder is diagnosed in many centers throughout the world. The findings were replicated with the other half of the patient group. The criteria constitute an operational method for identifying patients who would be commonly considered schizophrenic in many centers.
Micrometeorite Craters Discovered on Chondrule-Like Objects from Kapoeta Meteorite
Authors: Brownlee D. E. , Rajan R. S.
Published: October 2006

Craters attributable to hypervelocity impacts of micrometeorites have been discovered on rare chondrule-like objects from the gas-rich meteorite Kapoeta. These chondrule-like objects, probably generated by impacts themselves, provide further evidence for the regolith origin of Kapoeta. The micrometeorite flux at the time of formation of the meteorites was probably an order of magnitude higher than the present flux, but the solar luminosity could not have been higher than 1.7 times its present value.
The
ras
Oncoprotein and M-Phase Activity
Authors: Daar Ira , Nebreda Angel R. , Yew Nelson , Sass Philip , Paules Richard , Santos Eugenio , Wigler Michael , Vande Woude George F.
Published: October 2006

The endogenous
mos
proto-oncogene product (Mos) is required for meiotic maturation. In
Xenopus
oocytes, the
ras
oncogene product (Ras) can induce meiotic maturation and high levels of M-phase-promoting factor (MPF) independent of endogenous Mos, indicating that a parallel pathway to metaphase exists. In addition, Ras, like Mos and cytostatic factor, can arrest
Xenopus
embryonic cell cleavage in mitosis and maintain high levels of MPF. Thus, in the
Xenopus
oocyte and embryo systems Ras functions in the M phase of the cell cycle. The embryonic cleavage arrest assay is a rapid and sensitive test for Ras function.
The Brunhes Epoch: Isotopic Paleotemperatures and Geochronology
Authors: Emiliani Cesare , Shackleton Nicholas J.
Published: October 2006

Oxygen isotopic analysis of a long piston core from the western equatorial Pacific has produced a record for the entire Brunhes epoch. This record can be correlated point by point with the isotopic records of previously analyzed Atlantic and Caribbean cores, leading to the construction of a generalized temperature curve for the entire Brunhes epoch.
Toxaphene Insecticide: A Complex Biodegradable Mixture
Authors: Casida John E. , Holmstead Roy L. , Khalifa Safy , Knox John R. , Ohsawa Tomihiko , Palmer Kenneth J. , Wong Rosalind Y.
Published: October 2006

Adsorption and gas-liquid chromatography separate toxaphene into at least 175 polychlorinated 10-carbon compounds including Cl
6
, Cl
7
, Cl
8
, Cl
9
, and Cl
10
derivatives. One toxic component is 2,2,5-
endo
,6-
exo
,8,9,10-heptachlorobornane. Rats metabolically dechlorinate toxaphene, removing about half of the chlorine from the technical insecticide and from each of seven subfractions of varying composition and toxicity.
Parathyroid Secretion: Discovery of a Major Calcium-Dependent Protein
Authors: Kemper Byron , Habener Joel F. , Rich Alexander , Potts John T.
Published: October 2006

Bovine parathyroid tissue incubated in vitro secretes a protein that is distinct from both parathyroid hormone and proparathyroid hormone and comprises about 50 percent of the total secreted protein. This protein appears to be an aggregate consisting of two or more subunits of molecular weight 70,000 as determined by polyacrylamide gel electrophoresis in sodium dodecyl sulfate. Although the function of this protein is unknown, the secretion rates of both the protein and parathyroid hormone respond in parallel to changes in the concentration of calcium in the medium.
Human Acid Phosphatase in Somatic Cell Hybrids
Authors: Bruns Gail A. P. , Gerald Park S.
Published: October 2006

The human enzyme, lysosomal acid phosphatase ACP
2
, is expressed in man-rodent somatic cell hybrids as a dimeric molecule. The human-rodent heteropolymer, as well as the human and rodent homopolymer, is associated with lysosomes in these cells. The genes specifying lysosomal acid phosphatase ACP
2
and LDH A are syntenic.
Elephant Seals: Genetic Variation and Near Extinction
Authors: Bonnell Michael L. , Selander Robert K.
Published: October 2006

Blood samples from northern elephant seals (
Mirounga angustirostris
), representing five breeding colonies in California and Mexico, were surveyed electrophoretically for protein variation reflecting underlying genetic differences. No polymorphisms were found among 21 proteins encoded by 24 loci. This uniform homozygosity may be a consequence of fixation of alleles brought about by the decimation of this species by sealers in the last century.
Behavioral Thermoregulation in Lizards: Importance of Associated Costs
Authors: Huey Raymond B.
Published: October 2006

The Puerto Rican lizard
Anolis cristatellus
behaviorally regulates body temperature in an open habitat but passively tolerates lower and more variable temperatures in an adjacent forest where basking sites are few and distant. Thermoregulation may be adaptive only when costs resulting from associated losses of time and energy are low.
Acupunctural Analgesia? Evaluation by Signal Detection Theory
Authors: Clark W. Crawford , Yang J. C.
Published: October 2006

Pain responses to noxious thermal stimulation decreased in the acupunctured arm of subjects as compared to the arm not treated with acupuncture; this result suggested that effective analgesia had been induced. However, sensory decision theory analysis of the data revealed no difference in discriminability. This failure to find a sensory (physiological) change strongly suggests that analgesia had not been induced. The sole effect of acupuncture was to cause the subjects to raise their pain criterion in response to the expectation that acupuncture works.
Deposition of DDE and Polychlorinated Biphenyls in Dated Sediments of the Santa Barbara Basin
Authors: Hom Wilson , Risebrough Robert W. , Soutar Andrew , Young David R.
Published: October 2006

Analysis of dated oceanic sediments from the Santa Barbara Basin of the Southern California Bight has shown that deposition of polychlorinated biphenyls (PCB) began about 1945 and that DDE [1,1-dichloro-2-2-bis(
p
-chlorophenyl)ethylene] first appeared in sediments deposited about 1952. Concentrations of both show a progressive increase through 1967; estimated deposition rates (in grams per square meter per year) in 1967 of DDE and PCB were 1.9 × 10
-4
and 1.2 × 10
-4
, respectively.
Positive Control of Transformed Phenotype in Hybrids between SV40-Transformed and Normal Human Cells
Authors: Croce Carlo M. , Koprowski Hilary
Published: October 2006

Somatic cell hybrids have been obtained between SV40-transformed Lesch-Nyhan fibroblasts, which are deficient in hypoxanthine-guanine phosphoribosyltransferase (HGPRT) and display glucose-6-phosphate dehydrogenase A (G6PD-A) activity, and late-passage HGPRT-positive W138 human embryo fibroblasts, which display G6PD-B activity. The human-human hybrid clones, which display G6PD-A and G6PD-B and heteropolymers of the two enzyme forms, have the same growth characteristic as the SV40-transformed parental cells and behave as continuous cell lines. The SV40 tumor antigen, the gene for which has been assigned to human chromosome 7, is present in all clones examined.
Control of Experimental Diabetes Mellitus in Rats by Transplantation of Fetal Pancreases
Authors: Brown Josiah , Molnar I. Gabriella , Clark William , Mullen Yoko
Published: October 2006

Experimental diabetes mellitus in young adult Lewis rats was successfully treated by transplantation of fetal pancreases from syngeneic fetuses. Complete or partial control lasting up to 165 days was achieved in 64 percent of recipients by using two to three pancreases of fetal age (15 to 18½ days) placed under each kidney capsule. Islets of Langerhans without exocrine elements were present in the transplants.
Fibroblast Growth Factor Receptors from Liver Vary in Three Structural Domains
Authors: Hou Jinzhao , Kan Mikio , McKeehan Kerstin , McBride George , Adams Pamela , McKeehan Wallace L.
Published: October 2006

Changes in heparin-binding fibroblast growth factor gene expression and receptor phenotype occur during liver regeneration and in hepatoma cells. The nucleotide sequence of complementary DNA predicts that three amino-terminal domain motifs, two juxtamembrane motifs, and two intracellular carboxyl-terminal domain motifs combine to form a minimum of 6 and potentially 12 homologous polypeptides that constitute the growth factor receptor family in a single human liver cell population. Amino-terminal variants consisted of two transmembrane molecules that contained three and two immunoglobulin-like disulfide loops, as well as a potential intracellular form of the receptor. The two intracellular juxtamembrane motifs differed in a potential serine-threonine kinase phosphorylation site. One carboxyl-terminal motif was a putative tyrosine kinase that contained potential tyrosine phosphorylation sites. The second carboxyl-terminal motif was probably not a tyrosine kinase and did not exhibit the same candidate carboxyl-terminal tyrosine phosphorylation sites.
Brain Catechol Synthesis: Control by Brain Tyrosine Concentration
Authors: Wurtman Richard J. , Larin F. , Mostafapour S. , Fernstrom J. D.
Published: October 2006

Brain catechol synthesis was estimated by measuring the rate at which brain dopa levels rose following decarboxylase inhibition. Dopa accumulation was accelerated by tyrosine administration, and decreased by treatments that lowered brain tyrosine concentrations (for example, intraperitoneal tryptophan, leucine, or parachlorophenylalanine). A low dose of phenylalanine elevated brain tyrosine without accelerating dopa synthesis. Our findings raise the possibility that nutritional and endocrine factors might influence brain catecholamine synthesis by controlling the availability of tyrosine.
Helicoidal Crack Propagation in Aluminous Orthoamphiboles
Authors: Stout James H.
Published: October 2006

Sodic and aluminous orthoamphiboles from metamorphosed volcanic rocks develop helicoidal fractures upon cooling, due to elastic strain gradients radial to the
c
-axis. This condition may arise from radial composition gradients involving substitution of tetrahedral silicon by aluminum in the double chain structure or from intergranular boundary constraints with adjacent quartz.
Lateral Diffusion of Visual Pigment in Photoreceptor Disk Membranes
Authors: Liebman P. A. , Entine G.
Published: October 2006

Visual pigment molecules are found to move transversely, but not longitudinally, in both rod and cone outer segments of mud puppy and frog. This is consistent with the idea that they are immersed in a two-dimensional fluid disk membrane. The diffusion coefficient for the motion is about 5 × 10
-9
square centimeters per second at 20°C, corresponding to a root-mean-square molecular displacement of 0.3 micrometer in 1 second.
Rocket Ultraviolet Spectrophotometry of Comet Kohoutek (1973f)
Authors: Feldman Paul D. , Takacs Peter Z. , Fastie William G. , Donn Bertram
Published: October 2006

Observations of Comet Kohoutek (1973f) in the spectral region between 1200 and 3200 angstroms were made from an Aerobee rocket on 5.1 January 1974 universal time. The strongest features observed were the Lyman alpha line of neutral atomic hydrogen at 1216 angstroms and the hydroxyl (OH) bands at 3090 and 3142 angstroms. Atomic oxygen and atomic carbon were also detected, and their luminosity implies a production rate (of carbon monoxide or carbon dioxide) commensurate with that of water vapor.
Stratospheric Ozone Destruction by Man-Made Chlorofluoromethanes
Authors: Cicerone Ralph J. , Stolarski Richard S. , Walters Stacy
Published: October 2006

Calculations indicate that chlorofluoromethanes produced by man can greatly affect the concentrations of stratospheric ozone in future decades. This effect follows the release of chlorine from these compounds in the stratosphere. Present usage levels of chlorofluoromethanes can lead to chlorine-catalyzed ozone destruction rates that will exceed natural sinks of ozone by 1985 or 1990.
A Policy for Investment in Biomedical Research
Authors: Challoner David R.
Published: October 2006

Given a continuation of the current approach toward the managing and funding of research across the spectrum of disciplines basic to health, the country is headed for stultification and possible social disaster. Health care delivery should be considered as a science-based social industry and managed accordingly. Stability and adequate relation of the research effort to the industry's output should be sought. The establishment of a trust fund, derived as a percentage of health revenues, and of a public commission or a board of directors to provide expert advice on its expenditures are suggested.
Phosphate Release and Sorption by Soils and Sediments: Effect of Aerobic and Anaerobic Conditions
Authors: Patrick W. H. , Khalid R. A.
Published: October 2006

Anaerobic soils released more phosphate to soil solutions low in soluble phosphate and sorbed more phosphate from soil solutions high in soluble phosphate than did aerobic soils. The difference in behavior of phosphate under aerobic and anaerobic conditions is attributed to the change brought about in ferric oxyhydroxide by soil reduction. The probably greater surface area of the gel-like reduced ferrous compounds in an anaerobic soil results in more soil phosphate being solubilized where solution phosphate is low and more solution phosphate being sorbed where solution phosphate is high.