bluuebunny/crossref_metadata_2025 huggingface dataset:
Potassium-Argon Ages and Spreading Rates on the Mid-Atlantic Ridge at 45° North
Authors: Aumento F. , Wanless R. K. , Stevens R. D.
Published: October 2006

Potassium-argon dates obtained from extrusives collected on a traverse across the Mid-Atlantic Ridge at 45°N are consistent with the hypothesis of ocean-floor spreading. The dates suggest a spreading rate in the range of 2.6 to 3.2 centimeters per year near the axis of the ridge; the rate agrees with that computed from fission-track dating of basalt glasses. Additional data for a basalt collected 62 kilometers west of the axis gives a spreading rate of 0.8 centimeter per year, which is similar to the rate inferred from magnetic anomaly patterns in the area. Reasons for the difference in calculated spreading rates are discussed.
Sarcomeric Oscillations in Frog Skeletal Muscle Fibers
Authors: Marco Luis A. , Nastuk William L.
Published: October 2006

Brief asynchronous, small-amplitude, cyclic, longitudinal displacements of the striations of frog skeletal muscle fibers were observed with ordinary light microscopy after application of caffeine and certain quaternary ammonium compounds. With time these oscillations became synchronized and evolved into peristaltic-like movements. The oscillations were influenced by sarcomere length, temperature, external concentration of calcium ions, membrane potential, and disruption of the transverse tubules.
Induction of Collagenolytic and Proteolytic Activities in Rat and Human Fibroblasts by Anti-Inflammatory Drugs
Authors: Houck J. C. , Sharma V. K.
Published: October 2006

Confluent monolayers of either mouse or diploid human fibroblasts contained no measurable amounts of either collagenolytic (
p
H 5.5) or proteolytic (
p
H 7.5) activities. Within a few hours after exposure of these cells to antiinflammatory drugs, significant amounts of these enzymatic activities were demonstrable extracellularly. These activities were profoundly decreased in cultures simultaneously treated with the anti-inflammatory drugs and cycloheximide or actinomycin D.
Neuronal Geometry: Determination with a Technique of Intracellular Dye Injection
Authors: Stretton A. O. W. , Kravitz E. A.
Published: October 2006

In a study of the specificity of neuronal connections in lobster abdominal ganglia, the dye Procion Yellow M4RS was electrophoretically injected into identified cell bodies. This dye spreads into fine branches of cells, survives fixation and routine histological procedures, and permits the reconstruction of cell shapes through examination of serial sections of ganglia. Certain cells were found to have an internal bilateral symmetry. Repeated injection of the same cells in ganglia from different animals showed that cells have characteristic shapes and that the neuropil is highly structured. This method of dye injection should have general applicability in studies where a knowledge of the geometry of specific cells is important.
Shatter Cones at Sierra Madera, Texas
Authors: Howard Keith A. , Offield Terry W.
Published: October 2006

Shatter cones abound in the central uplift of Sierra Madera and they occur as far as 6.5 kilometers from the center. Apical angles average near 90 degrees. Whole cones and full cones represented by diversely oriented cone segments in any structural block show relatively uniform orientations of axes and a dominant direction of point. The cones predate faulting and folding in the central uplift, and, when beds are restored to horizontal, most cones point inward and upward, a pattern that supports the hypothesis of an impact origin.
Lateral Giant Fibers of Crayfish: Location of Somata by Dye Injection
Authors: Remler M. , Selverston A. , Kennedy D.
Published: October 2006

Using a new technique for injecting fluorescent dye, we have analyzed the intraganglionic architecture of the lateral giant interneuron in crayfish. Each lateral giant interneuron comprises a giant axon, an ipsilateral dendritic arborization of fairly constant form, and a contralateral soma. Antidromic axon spikes produce only small, electronic potentials in the soma; direct depolarization there fails to produce electrically excitable membrane responses and cannot discharge the main axon.
Multiple Forms of Bacterial NADP-Specific Isocitrate Dehydrogenase
Authors: Reeves Henry C. , Brehmeyer Bette Ann , Ajl Samuel J.
Published: October 2006

Electrophoretically distinct forms of nicotinamide adenine dinucleotide phosphate-specific isocritrate dehydrogenase have been observed in extracts of
Escherichia coli
grown under different culture conditions. In glucose-grown cells, two distinct bands of isocitrate dehydrogenase activity were observed on polyacrylamide gels and have been completely resolved by employing ion-exchange chromatography. These multiple forms of the enzyme have been studied and their possible metabolic role is discussed.
Autoimmune Chorioretinitis in Rhesus Monkeys
Authors: Lerner Edwin M. , Stone Sanford H. , Myers Ronald E. , von Sallmann Ludwig
Published: October 2006

Monkeys injected with monkey retinal tissue incorporated in Freund's complete adjuvant developed ocular lesions characterized by choroiditic patches in the fundus periphery and sheathing of retinal vessels. Bovine retina, monkey choroid plexus, and guinea pig kidney were ineffective in this respect.
Hurler and Hunter Syndromes: Mutual Correction of the Defect in Cultured Fibroblasts
Authors: Fratantoni Joseph C. , Hall Clara W. , Neufeld Elizabeth F.
Published: October 2006

The biochemical defect of cultured skin fibroblasts from Hurler or Hunter patients (faulty degradation of sulfated mucopolysaccharide, resulting in excessive intracellular accumulation) may be corrected if cells of these two genotypes are mixed with each other or with normal cells. The effect is mediated by substances released into the medium.
A Hyperpolarizing Component of the Receptor Potential in the Median Ocellus of Limulus
Authors: Nolte John , Brown Joel E. , Smith T. G.
Published: October 2006

There are two classes of photoreceptor cells in the median ocellus of
Limulus
. One class of cells respond to long wavelength (visible) stimuli with a depolarizing receptor potential and to near ultraviolet light with a biphasic, initially hyperpolarizing, receptor potential. The other class of receptors respond with a depolarization to near ultraviolet and with a biphasic response to visible light. In the latter type of cell, visible light can counteract the depolarization elicited by near ultraviolet light. The evidence suggests that there are two photopigments in each cell and that both are involved in the generation of receptor potential.
Genetic Implications of Common Region Sequence Comparisons of Lambda Immunoglobulin Chains Differing at Position 190
Authors: Hood Leroy , Ein Daniel
Published: October 2006

The common regions of two lambda chains (amino acid residues 109 to 213) have been partially sequenced. These two human immunoglobulin chains have lysine at position 190, but are otherwise identical in their common-region sequence to four reported lambda chains that have arginine at position 190. The single amino acid interchange at position 190 may be explained either by an ambiguous codon at this position or by a gene duplication so recent that only a single mutational event has occurred.
Specificity of Ribonuclease Ch from
Chalaropsis
Species
Authors: Hash John H. , Elsevier Susan
Published: October 2006

A ribonuclease is produced by the fungus
Chalaropsis
sp. that appears to have an absolute specificity for 3′-guanylic acid residues in ribonucleic acid.
Hepatic Microsomal Enzymes in Man and Rat: Induction and Inhibition by Ethanol
Authors: Rubin Emanuel , Lieber Charles S.
Published: October 2006

The feeding of ethanol increased significantly the activities of hepatic pentobarbital and benzpyrene hydroxylases in rats, and, in human volunteers, doubled pentobarbital hydroxylase activity. In vitro ethanol inhibited aniline, pentobarbital, and benzpyrene hydroxylases. These data may explain, at least in part, the increased tolerance of alcoholics to sedatives when sober, and the enhanced sensitivity to sedatives when inebriated.
Dietary Regulation of Galactose-Metabolizing Enzymes: Adaptive Changes in Rat Jejunum
Authors: Stifel Fred B. , Herman Robert H. , Rosensweig Norton S.
Published: October 2006

The effects of dietary galactose, sucrose, fructose, glucose, casein, and fasting upon the activity of four galactose-metabolizing enzymes (galactokinase, galactose-1-phosphate uridyltransferase, uridine diphosphate galactose 4-epimerase, and galactose dehydrogenase) were studied in the jejunum of rats. Galactose produced the greatest increase in enzyme activity, fructose and sucrose produced effects intermediate between galactose and glucose, and casein produced a greater activity increase than fasting, but less than the sugars.
Search for an Effect of Mass on Frequency during a Close Approach of Pulsar CP 0950 to the Sun
Authors: Sadeh D. , Hollinger J. P. , Knowles S. H. , Youmans A. B.
Published: October 2006

Observations of the pulse arrival times from the pulsar CP 0950 were made during August when the line of sight to the pulsar approached within 5 degrees of the sun in order to test a suggested mass-on-frequency effect. The observations do not show evidence for the predicted effect.
Earth's Bow Shock: Elapsed-Time Observations by Two Closely Spaced Satellites
Authors: Greenstadt E. W. , Green I. M. , Colburn D. S.
Published: October 2006

Coordinated observations of the earth's bow shock were made as Vela 3A and Explorer 33 passed within 6 earth radii of each other. Elapsed time measurements of shock motion give directly determined velocities in the range 1 to 10 kilometers per second and establish the existence of two regions, one of large amplitude magnetic "shock" oscillations and another of smaller, sunward, upstream oscillations. Each region is as thick as 1 earth radius, or more.
Phagocytosis of Inhaled Plutonium Oxide-
239
Pu Particles by Pulmonary Macrophages
Authors: Sanders C. L. , Adee R. R.
Published: October 2006

Pulmonary macrophages and plutonium particles were removed by washing the lungs of rats that had inhaled plutonium oxide-
239
Pu. A significant amount of plutonium was found in multiple washings of the same lung. The removal of toxic particles by washing is of potential therapeutic value. Particles were phagocytized by macrophages during the first 3 hours and retained within these cells for up to 25 days. Nearly all particles in washings were found in macrophages after the second day. The percent of macrophages with engulfed particles increased with increasing amounts of plutonium deposited in the lungs. The ability of pulmonary macrophages to rapidly phagocytize and retain plutonium particles deposited in the lungs has been shown.
Manganese Nodules in Lake Michigan
Authors: Rossmann Ronald , Callender Edward
Published: October 2006

Manganese nodules containing up to 22 percent manganese oxide were found in Green Bay and the western and northern parts of Lake Michigan. The chemical composition of these nodules resembles that of shallow-water lacustrine and marine nodules. The manganese content of interstitial water is in some places enriched as much as 4000 times over that of lake water.
Flagellar Adenosine Triphosphatase from Sea Urchin Sperm: Properties and Relation to Motility
Authors: Claybrook J. R. , Nelson Leonard
Published: October 2006

Adenosine triphosphatase activated by divalent cations is apparently a component of the motile apparatus in flagella of
Arbacia
sperm, as judged by the activity of this enzyme in intact flagella, glycerol-extracted flagella, and soluble extracts prepared from flagella. However, the variation in the physical properties and in the amount of enzyme obtained after a variety of treatments suggests that additional components are involved in the motile mechanism. These features distinguish the soluble flagellar enzyme from adenosine triphosphatases of other motile cells.
Chemical Potential of Water from Measurements of Optic Axial Angle of Zeolites
Authors: Eberlein G. Donald , Christ C. L.
Published: October 2006

Values of the uncorrected optic axial angle (2
H
α
) of a crystal of the calcium zeolite stellerite (CaAl
2
Si
7
O
18
⋅ 7H
2
O) immersed in calcium chloride solutions of known activity of water (
a
w
) are directly proportional to log
a
w
. A general relationship between the chemical potential of water in the crystal and the optic axial angle is obeyed.
Light Scattering in Central Arctic Ocean: Some Winter Profiles
Authors: Neshyba Stephen , Beardsley George F. , Neal Victor T. , Carder Kendall
Published: October 2006

Measurements for light scattering in an Arctic water column reveal strong gradients and variability of the order of 15 percent in depths of less than 500 meters. The region of variability appears to persist from day to day and is roughly associated with the typical hydrographic features of the region. No definite nephelocline was observed.
Zymogen Granules in Enzyme Liberation and Activation in Pea Seeds
Authors: Mayer A. M. , Shain Y.
Published: October 2006

Pea seeds have zymogen-like granules that contain an inactive form of the enzyme amylopectin-1,6-glucosidase. The enzyme can be liberated from the particles in the inactive form and can then be activated by limited proteolysis with trypsin.
Very-Low-Density Lipoprotein in Intestinal Lymph: Evidence for Presence of the A Protein
Authors: Ockner Robert K. , Bloch Kurt J. , Isselbacher Kurt J.
Published: October 2006

Rat mesenteric lymph very-low-density lipoproteins of intestinal origin contain components which are antigenically identical to plasma high-density lipoprotein. Because the antigenicity of the latter most likely resides in its apoprotein (the A protein), it is concluded that intestinal very-low-density lipoproteins contain the A protein. This and other evidence supports the concept that the intestine is a source of plasma very-low-density lipoprotein.
Conversion of Mesophilic to Psychrophilic Bacteria
Authors: Olsen Ronald H. , Metcalf Eleanor S.
Published: October 2006

The minimum temperature of growth of the mesophilic bacterium
Pseudomonas aeruginosa
has been significantly lowered from approximately 11° to 0°C. This shift in the minimum temperature of growth was accompanied by a corresponding decrease in the maximum temperature of growth. Transfer of this genetic characteristic by a transducing phage grown on a psychrophile or by ultraviolet mutagenesis was used to accomplish these shifts in range of growth temperature.
Insect Hormones: Olive Oil Is Not an Inert Vehicle for Hormone Injection into Locusts
Authors: Carlisle D. B. , Ellis P. E.
Published: October 2006

Like other fatty oils from plants, olive and peanut oils, the most commonly used vehicles for the injection of juvenile hormone and its analogs, contain substances that show effects similar to those of this hormone. A dose of olive oil smaller than that used to dissolve a single injection of juvenile hormone will cause nuclear enlargement in the cells of the prothoracic gland of the desert locus and advance the succeeding molt.
Surface Structure of Polymers: Glancing-Angle Electron Diffraction Study of Polyethylene
Authors: Schonhorn Harold , Drobek J.
Published: October 2006

The surface regions of polyethylene nucleated and crystallized in contact with both a high-energy surface (gold) and a low-energy surface (fluorinated ethylene-propylene copolymer Teflon) have been examined by means of glancing-angle electron-diffraction techniques. Examination of these surfaces has been confined to a maximum depth of 120 angstroms. The surface region of the polyethylene generated in contact with the gold is considerably more crystalline than the surface generated in contact with the fluorinated ethylene-propylene copolymer Teflon. These results tend to corroborate recent wettability and infrared studies. Apparently, the surface structure of polyethylene is highly dependent upon the method of preparation.
Crayfish Muscle Fiber: Spike Electrogenesis in Fibers with Long Sarcomeres
Authors: Ozeki Masahiro
Published: October 2006

Most of the muscle fibers in the walking legs of the crayfish
Procambarus clarkii
generate only graded electrical responses. However, some fibers in extensor muscles of the carpopodite have long sarcomeres, about 10 micrometers in length, and generate overshooting spikes that have conduction velocities of 0.3 meter per second. The spikes induce twitch contractions.
Nitrogen Abundances in Chondritic Meteorites
Authors: Moore Carleton B. , Gibson Everett K.
Published: October 2006

Carrier-gas fusion extractions of total nitrogen in 22 chondritic meteorites indicate a wide variation in total nitrogen contents, ranging from 660 parts per million for an enstatite chondrite to 18 parts per million for an ordinary chondrite. Total nitrogen and total carbon contents of individual chondrites do not show a positive correlation.
Gravitational Mechanism for Sea-Floor Spreading
Authors: Pollack Henry N.
Published: October 2006

The gravitational attraction of the continents produces a force field at the surface of the earth, similar in geometry to lithospheric displacements deduced from studies of earthquake focal mechanisms.
Potassium-Sodium Ratios in Aqueous Solutions and Coexisting Silicate Melts
Authors: Gammon J. B. , Borcsik M. , Holland H. D.
Published: October 2006

Silicate melts were equilibrated with aqueous chloride solutions at temperatures between 770° and 880°C and a total pressure of 1.4 to 2.4 kilobars. The ratio of potassium to sodium in the aqueous phase was (0.74 ± 0.06) times the corresponding ratio in the coexisting melt over the entire range of temperature and pressure for all chloride concentrations between 0.2 and 4.2 moles per kilogram.
β-1,3-Glucanase of Sea Urchin Eggs: Release from Particles at Fertilization
Authors: Epel David , Weaver Anthony M. , Muchmore Andrew V. , Schimke Robert T.
Published: October 2006

β-1,3-Glucanase is a latent enzyme found in large and small particles in unfertilized eggs. At fertilization, the enzyme in the large particles is released into the surrounding perivitelline space. The enzyme may be involved in transformations of extracellular glycoproteins.
Laser Diffraction Studies on Single Skeletal Muscle Fibers
Authors: Cleworth Derek , Edman K. A. P.
Published: October 2006

Sarcomere movements during isometric tetanic contractions were resolved to 50 angstroms by diffraction techniques. After a latent period that followed the first stimulus, all sarcomeres shortened simultaneously and uniformly. Oscillations in length and tension in synchrony with the stimuli occurred during an incomplete tetanus. However, no oscillations in length were detected during the plateau of a fused tetanus.
Shark Pit Organs: Response to Chemicals
Authors: Katsuki Yasuji , Yanagisawa Keiji , Tester Albert L. , Kendall James I.
Published: October 2006

Nerve fibers from pit organs and canal neuromasts are distinguished by the nature of their electrophysiological response to mechanical and chemical stimulation. Pit organs respond to touch but have a relatively high threshold compared with canal neuromasts. They respond readily to sodium and potassium chloride solutions, the rate of discharge increasing with the concentration of the solution. Order of effectiveness with 1 molar solutions of monovalent cations is as follows: potassium, rubidium > sodium, ammonium > cesium, lithium. Anions are ineffective. Divalent cations such as calcium and magnesium are inhibitory. Responses to acid, sugar, and quinine are either very slight or inhibitory.
Water on the Moon and a New Nondimensional Number
Authors: O'Keefe John A.
Published: October 2006

A nondimensional number called the Jeffreys number, which represents the ratio of the Reynolds number to the Froude number, is useful in geophysical problems related to the motion of viscous masses under gravity. The Jeffreys number is used to show that it is impossible for the lunar maria to be underlain by a layer of material 1 kilometer thick having the plastic properties of ice.
Hoabinhian: A Pebble-Tool Complex with Early Plant Associations in Southeast Asia
Authors: Gorman Chester F.
Published: October 2006

The term "Hoabinhian" has been applied to "mesolithic" assemblages from all parts of mainland Southeast Asia. Recent excavation in north Thailand has yielded the first associated carbon-14 dates and provided evidence for the early (about 7000 B. C.) domestication of plants in Southeast Asia.
Generalized Gangliosidosis: Impaired Cleavage of Galactose from a Mucopolysaccharide and a Glycoprotein
Authors: MacBrinn Monica C. , Okada Shintaro , Ho Mae Wan , Hu Chin Chai , O'Brien John S.
Published: October 2006

We have demonstrated a tenfold (or greater) reduction of the cleavage of galactose from a mucopolysaccharide and a glycoprotein in generalized gangliosidosis, a lysosomal β-galactosidase deficiency disease. The bony abnormalities in this disease may be due to defective catabolism of mucopolysaccharides in connective tissue.
N
-Formylseryl—Transfer RNA
Authors: Kim W. S.
Published: October 2006

The reactions between serine and transfer RNA from baker's yeast and from
Escherichia coli
have been investigated. Results obtained from in vitro, in vivo, and chemical syntheses and from electrophoretic, chromatographic, and radioautographic analyses demonstrate that
N
-formylseryl-transfer RNA is formed in these systems.
"Blow" of the Pilot Whale
Authors: Olsen C. Robert , Elsner Robert , Hale Frank C. , Kenney David W.
Published: October 2006

A captive pilot whale emptied as much as 88 percent of lung gas passively, without the aid of expiratory muscles. Level or decreasing pressures in the esophagus during expiration, and in the blowhole at the onset of expiration, revealed the driving force of expiration to be solely elastic recoil. Active muscular reexpansion of the lungs ensued immediately. Expiration and inspiration were completed in about 1 second.
Spectra, Variability, Size, and Polarization of H
2
O Microwave Emission Sources in the Galaxy
Authors: Knowles S. H. , Mayer C. H. , Cheung A. C. , Rank D. M. , Townes C. H.
Published: October 2006

Radio spectral line radiation of water molecules at a wavelength of 1.35 centimeters has been measured from eight sources in the galaxy. The sources are less than 1 arc minute in diameter, have extremely high brightness temperatures, and show many spectral features. Some spectral features are slightly polarized and some have changed greatly in intensity in a few weeks time.
Thyroid-Stimulating Hormone and Prostaglandin E
1
Stimulation of Cyclic 3′,5′-Adenosine Monophosphate in Thyroid Slices
Authors: Kaneko Toshio , Zor Uriel , Field James B.
Published: October 2006

Thyroid-stimulating hormone increased the cyclic 3′,5′-adenosine monophosphate concentration in dog thyroid slices during a 1-minute incubation period and produced a maximum effect soon thereafter. The elevation persisted for at least 30 minutes. The concentrations of the cyclic 3′,5′-adenosine monophosphate increased as the TSH concentration was increased from 0.125 to 50 milliunits per milliliter. Prostaglandin E
1
, which increases glucose oxidation in dog thyroid slices, also increased the concentration of cyclic 3′,5′-adenosine monophosphate. Although sodium fluoride stimulates thyroid adenyl cyclase, it did not increase concentration of cyclic 3′,5′-adenosine monophosphate. Carbamylcholine and menadiol sodium diphosphate augment glucose oxidation in dog thyroid slices but do not change concentrations of cyclic 3′,5′-adenosine monophosphate.
Automatic Identification and Measurement of Cells by Computer
Authors: Rosenberg Steven A. , Ledeen Kenneth S. , Kline Tilde
Published: October 2006

A visual-input computer system was used to automatically locate and perform measurements with high accuracy on single cells from microscopic slides. The nuclear radius, irregularity, area, and density of normal and malignant cells were automatically measured. These studies agreed with hand measurements and showed differences between normal and malignant cervical cells on Papanicolaou smears.
Thorny-Headed Worm Infection in North American Prehistoric Man
Authors: Moore John G. , Fry Gary F. , Englert Edwin
Published: October 2006

Examination of ova and parasites from coprolites of probable human origin revealed eggs of the phylum Acanthocephala. Specimens were gathered from Danger Cave in Utah, an area heavily populated with definitive rodent hosts for the Acanthocephala species
Moniliformis clarki
. It is postulated that prehistoric man developed Acanthocephala infection by ingesting the arthropod intermediate host, or that he was a victim of false parasitism by ingesting the whole rodent.
Hydration of Macromolecules
Authors: Kuntz I. D. , Brassfield T. S. , Law G. D. , Purcell G. V.
Published: October 2006

Frozen protein and nucleic acid solutions at -35°C show relatively narrow (100 milligauss) proton nuclear magnetic resonance signals which are assignable to water that is sufficiently mobile to reduce the dipolar broadening normally associated with solids. Hydration was found to be 0.3 to 0.5 gram of water per gram of protein. Nucleic acids are three to five times as hydrated as proteins. Conformational changes in solution produce detectable changes in line-width or amount of "bound" water, or both. The very fact that the water signals can be observed by high resolution nuclear magnetic resonance suggests that it is not "ice-like" in any literal sense, although it is clearly less mobile than liquid water at the same temperature. A simple model is described which considers both surface hydration and trapped water.
Potassium Ion: Is the Bulk of Intracellular K
+
Adsorbed?
Authors: Ling Gilbert N. , Cope Freeman W.
Published: October 2006

When a major portion of the intracellular K
+
in frog muscle is reversibly replaced by Na
+
, the extra Na
+
gained by the cells does not show the nuclear magnetic resonance signal that free Na
+
does. The data contradict the membrane theory but are in accord with the concept that the bulk of intracellular K
+
is adsorbed.
Conductivity and Photoconductivity in Egg White
Authors: Spruch Grace Marmor , Peskin Charles
Published: October 2006

Activation energies of 1.47 to 2.94 electron volts were obtained in egg white. These values are too large to be consistent with the large observed currents if one uses a semiconductor model and indicate that the standard semiconductor model is inappropriate for this biological material.
New Antheridiogen from the Fern
Onoclea sensibilis
Authors: Näf Ulrich , Sullivan James , Cummins Michael
Published: October 2006

An antheridium-inducing hormone (antheridiogen) derived from the fern species
Onoclea sensibilis
(Polypodiaceae) is chromatographically distinct from the native antheridiogen of Pteridium aquilinum (Polypodiaceae). It also differs from the native antheridiogens of
Lygodium japonicum
and
Anemia phyllitidis
(Schizaeaceae).
Crystal Structure of Transforming Growth Factor-β2: an Unusual Fold for the Superfamily
Authors: Daopin Sun , Piez Karl A. , Ogawa Yasushi , Davies David R.
Published: October 2006

The transforming growth factors-β (TGF-β1 through -β5) are a family of homodimeric cytokines that regulate proliferation and function in many cell types. Family members have 66 to 80% sequence identity and nine strictly conserved cysteines. A crystal structure of a member of this family, TGF-β2, has been determined at 2.1 angstrom (Å) resolution and refined to an
R
factor of 0.172. The monomer lacks a well-defined hydrophobic core and displays an unusual elongated nonglobular fold with dimensions of approximately 60 Å by 20 Å by 15 Å. Eight cysteines form four intrachain disulfide bonds, which are clustered in a core region forming a network complementary to the network of hydrogen bonds. The dimer is stabilized by the ninth cysteine, which forms an interchain disulfide bond, and by two identical hydrophobic interfaces. Sequence profile analysis of other members of the TGF-β superfamily, including the activins, inhibins, and several developmental factors, imply that they also adopt the TGF-β fold.
Visually Evoked Oscillations of Membrane Potential in Cells of Cat Visual Cortex
Authors: Jagadeesh Bharathi , Gray Charles M. , Ferster David
Published: October 2006

In response to visual stimulation, cells of the cat visual cortex fire rhythmically at frequencies between 30 and 60 hertz. This rhythmic firing can be synchronized among cells in widespread areas of the visual cortex. The visual stimulus conditions under which this process occurs suggest that the synchronization may contribute to the integration of information across broadly displaced parts of the visual field. An intricate mechanism must control the regularity of firing and its synchronization. In vivo whole-cell patch recordings from cells in area 17 have now shown that robust oscillations of membrane potential underlie the regularity of firing seen extracellularly. In the cells studied, the characteristics of the oscillations of membrane potential suggest that such oscillations are produced by rhythmic activity in synaptic inputs. These rhythmic synaptic inputs form the most likely mechanism for the synchronization of activity in neighboring cortical cells.
Antarctic Atmospheric Chemistry: Preliminary Exploration
Authors: Fischer W. H. , Lodge J. P. , Pate J. B. , Cadle R. D.
Published: October 2006

The particulate and trace gas content of polar air is very similar to that of tropical air despite differences in climatology and biotic activity.
Mammary Tumor Virus Antigen: Sensitive Immunoassay
Authors: Sibal Louis R. , Feller William F. , Fink Mary Alexander , Kohler Barbara E. , Hall William T. , Bond Howard E.
Published: October 2006

A rapid, sensitive immunoassay for mammary tumor virus antigen based on inhibition of passive hemagglutination has been developed. The method permits measurement of this antigen in mouse milk from which the fat has been removed.
Lysergic Acid Diethylamide: Dissociation of Its Behavioral and Hyperthermic Actions by DL-α-Methyl-p-Tyrosine
Authors: Horita A. , Hamilton A. E.
Published: October 2006

Rabbits treated with LSD 25 exhibit characteristic signs of hyperexcitability, increased peripheral sympathetic activity, and hyperthermia. When the rabbits received prior treatment with DL-α-methyl-p-tyrosine, the excitation and sympathetic actions of LSD 25 were abolished or attenuated, but the hyperthermia was unchanged from that of the controls. Concentrations of norepinephrine in brain stems of treated rabbits were greatly decreased. The excitation of central nervous system and sympathomimetic actions of LSD 25 in the rabbit are apparently mediated by norepinephrine, whereas the hyperthermic action functions through a nonadrenergic mechanism.
Mars: Correlation of Optical and Radar Observations
Authors: Robinson J. C.
Published: October 2006

A comparison of recent photographic and radar data on Mars indicates a good positive correlation between dark areas and radar reflection peaks and also between cloudy "desert" areas and radar minima. The data may be taken as evidence that dark areas are, in general, relatively smooth whereas deserts are relatively rough.
Linkage of Lactate Dehydrogenase B and C Loci in Pigeons
Authors: Zinkham W. H. , Isensee H. , Renwick J. H.
Published: October 2006

Synthesis of lactate dehydrogenase in somatic and gametic tissues of certain avian and mammalian species is controlled by alleles at three loci,
A
,
B
, and
C
. We report breeding experiments with pigeons that conclusively demonstrate linkage between the
B
and
C
structural loci in this species. The most probable recombination fraction is zero, and contiguity is not excluded. The upper 95 percent probability limit is 4.5 percent. This tight linkage of two loci that produce closely similar polypeptides suggests that the loci acquired their separate identities through a duplication event. Furthermore, the existence of recognizable B- and C-type polypeptides in both the bird and the mammal suggests that the event and the resulting linkage preceded the separation of these fauna. If so, then the linkage has persisted for a very long time.
Immunological Detection of Single Amino Acid Substitutions in Alkaline Phosphatase
Authors: Cocks G. T. , Wilson A. C.
Published: October 2006

Antiserums to wild-type alkaline phosphatase from
Escherichia coli
were prepared and tested for reactivity with phosphatases altered by point mutations. Eight out of the nine mutant enzymes were distinguished from the wild type with quantitative microcomplement fixation. The structural changes are among the smallest yet observed immunologically.
Cycads: Evidence from the Upper Pennsylvanian
Authors: Taylor Thomas N.
Published: October 2006

The fossil record of true cycads is extended from the Upper Triassic to the upper Pennsylvanian.
Mode-Locked Lasers: Measurements of Very Fast Radiative Decay in Fluorescent Systems
Authors: Merkelo H. , Hartman S. R. , Mar T. , Govindjee G. S. Singhal
Published: October 2006

A mode-locked laser was used to measure fluorescence decay down to 80 picoseconds. Measurements on the fluorescence of methylene blue quenched with potassium iodide demonstrate the effectiveness of the method. Fluorescence decay times of chlorophyll b (3.87 ± 0.05 nanoseconds) and c-phycocyanin (1.14 ± 0.01 nanoseconds) in vitro and chlorophyll a in the green alga Chlorella pyrenoidosa (1.14 to 1.6 nanoseconds) compare well with some of the existing data.
Lunar Thermal Anomalies: Infrared Observations
Authors: Allen D. A. , Ney E. P.
Published: October 2006

The lunar craters Tycho, Copernicus, and Aristarchus have been observed during lunar night at wavelengths between 3 and 14 microns. After an initial fast decrease to a color temperature of 220°K, the temperature remains nearly constant through the lunar night. The data suggest that these thermal anomalies (craters) contain hot and cold regions with the hot portions constituting 2 to 10 percent of the area and probably thermally connected to a subsurface temperature of about 200°K.
Olmec Cave Paintings: Discovery from Guerrero, Mexico
Authors: Grove David C.
Published: October 2006

A cave in Guerrero, Mexico, investigated in 1968, contained previously unreported Olmec paintings. These paintings, some of the oldest known in Mesoamerica, are stylistically similar to Olmec art from the site of LaVenta, on Mexico's Gulf Coast, but contain several important glyphic motifs never previously known to have existed at this time level. The iconography of the paintings confirms several important hypotheses concerning basic concepts of Olmec religion; the cave itself was probably a shrine to water and fertility. Several pre-Hispanic textile fragments found in the cave are probably from a later culture period.
Pheromone-Induced Changes in the Acidophil Concentration of Mouse Pituitary Glands
Authors: Avery Thomas L.
Published: October 2006

Pituitaries of female mice in anestrus resulting from colony housing were characterized by a 58.0-percent acidophil content. Subsequent exposure to restrained male mice for one and two nights failed to evoke significant acidophilic degranulation and resulted in pituitary acidophil values of 57.4 and 55.1 percent respectively. Exposure to released males on the third night produced marked acidophilic degranulation resulting in a significant decline in pituitary acidophils to 38.0 percent. These findings support the view that female pheromone suppresses and male pheromone favors the secretion of follicle-stimulating hormone and indicate that luteotrophic hormone is secreted at its assigned time in the sequence of cyclic ovarian events initiated by the secretion of follicle-stimulating hormone.
Mycoplasma Membrane Lipids: Variations in Fatty Acid Composition
Authors: McElhaney Ronald N. , Tourtellotte Mark E.
Published: October 2006

The fatty acid composition of the membrane polar lipids of
Mycoplasma laidlawii
B can be dramatically altered. These variations result in characteristic morphological changes, and in most cases the cells remain viable. This organism should provide a useful system for clarifying the role of fatty acyl chains in biological membranes.
Resistance to Metronidazole by
Trichomonas foetus
in Hamsters Infected Intravaginally
Authors: Actor P. , Ziv D. S. , Pagano J. F.
Published: October 2006

Induced resistance to the antitrichomonad agent metronidazole administered to hamsters infected intravaginally with
Trichomonas foetus
and treated with subcurative levels of metronidazole was demonstrated in vitro and in vivo.
Cochlear Distortion: Effect of Direct-Current Polarization
Authors: Dallos P. , Schoeny Z. G. , Worthington D. W. , Cheatham M. A.
Published: October 2006

Intermodulation components (combination tones) appearing in microphonic potentials were measured from guinea pig cochleas with and without polarizing direct currents passing through the cochlear partition. At moderate intensities of stimulus the polarization had a qualitatively different effect on the distortion components than on their eliciting primaries or on pure tones simulating the distortion products. At high intensities, the primaries and the combination tones were similarly influenced by the polarizing current. It is concluded that cochlear distortion is a two-stage process, mechano-electrical at low levels and mechano-hydraulic at high levels.
Circadian Rhythm of Optic Nerve Impulses Recorded in Darkness from Isolated Eye of
Aplysia
Authors: Jacklet Jon W.
Published: October 2006

The isolated eye of the sea hare
Aplysia californica
shows a circadian rhythm of optic nerve impulses when kept in total darkness. Peak activity on the first day of isolation occurs during the projected "dawn" of the light-dark cycle to which the whole animal had previously been entrained. Eyes from animals previously exposed to constant light show a free-running rhythm. This simple photoreceptor provides a quantized output with an ideal control (the other eye) for studies on rhythms.
Sex Ratios of Newborns: Associated with Prepartum and Postpartum Schizophrenia
Authors: Taylor M. A.
Published: October 2006

From a review of the records of schizophrenic women whose psychotic symptoms were associated with pregnancy, it was found that those who had developed a psychosis within 1 month of conception delivered only live female infants. A predominance of males was born to 13 women who became psychotic during the first month after delivery. These observations are interpreted as consistent with a theory that schizophrenia is associated with plasma factors which interact with the fetus and provide the basis for a higher fetal mortality.
Generation and Maintenance of Gradients in Taxonomic Diversity
Authors: Stehli Francis G. , Douglas Robert G. , Newell Norman D.
Published: October 2006

Latitudinal gradients in diversity of organisms represent an equilibrium distribution for at least the last 270 × 10
6
years. Faunas endemic to tropical regions evolved significantly faster than extra-tropical faunas. The latitude-dependent difference in rates of evolution also represents an equilibrium condition for at least the last 270 × 10
6
years and has consequences for paleontological correlation of rocks because the attainable resolution depends on rate of evolution and will thus be greater in tropic regions than in extra-tropical ones.
Visualization of Nucleolar Genes
Authors: Miller O. L. , Beatty Barbara R.
Published: October 2006

The presence of extrachromosomal nucleoli in amphibian oocytes has permitted isolation and electron microscopic observation of the genes coding for ribosomal RNA precursor molecules. Visualization of these genes is possible because many precursor molecules are simultaneously synthesized on each gene. Individual genes are separated by stretches of DNA that apparently are not transcribed at the time of synthesis of precursor rRNA in the extrachromosomal nucleoli.
Nickel-63 in Marine and Terrestrial Biota, Soil, and Sediment
Authors: Beasley Thomas M. , Held Edward E.
Published: October 2006

A previously unreported radionuclide, nickel-63 (half-life, 92 years), produced in the testing of nuclear devices, was measured in biological and environmental samples from areas of the Pacific Ocean and the eastern seaboard of the United States. The concentrations of nickel-63 are low (maximum of 163 disintegrations per minute per gram of dry weight), but this radionuclide may be a useful tracer of oceanic processes because of its long half-life and long residence time in the ocean.
Lecithin Aerosols Generated Ultrasonically above 25°C
Authors: Merrill Edward W. , Graves David J. , Smith Kenneth A. , Shannon Daniel C. , Kazemi Homayoun
Published: October 2006

DL-Dipalmitoyl-α-lecithin, suspended in 0.15-molar sodium chloride solution by sonic cavitation at 20 kilohertz, can be aerosolized by an 800-kilohertz ultrasonic generator only at temperatures above 25°C. The aerosol thus produced is exceptionally stable against evaporation even at particle radii of 0.1 to 0.6 micron; this suggests applicability to the therapy of pulmonary disorders.
Sex Pheromone of the Queen Butterfly: Biology
Authors: Pliske T. E. , Eisner T.
Published: October 2006

Males of the queen butterfly
Danaus gilippus berenice
, deprived of the two extrusible brushlike "hairpencils" at the rear of their abdomen, are capable of courting females but incapable of seducing them. In normal courtship, an aphrodisiac secretion associated with the hairpencils is transferred by way of tiny cuticular "dust" particles to the antennae of the females. Of the two substances identified from the secretion, one (the ketone) acts as the chemical messenger that induces the females to mate. The only known function of the other compound (the diol) is to serve as a glue that sticks the dust to the female. Males were reared under conditions in which they produced subnormal amounts of ketone and showed reduced seductive capacity. Under certain experimental circumstances, the competence of these males was restored by addition of synthetic ketone.
Rate of Intracellular Diffusion as Measured in Barnacle Muscle
Authors: Bunch Wilton H. , Kallsen Gene
Published: October 2006

The rate of intracellular diffusion of water, urea, and glycerol was measured in the giant barnacle
Balanus nubilus
. The calculated diffusion coefficients were not different from those values reported for dilute solutions.
Moon: Two New Mascon Basins
Authors: Campbell Malcolm J. , O'Leary Brian T. , Sagan Carl
Published: October 2006

Lunar gravity data and orbital photography indicate that there is a mascon basin approximately 1000 kilometers in diameter on the farside of the moon and that Mare Marginis is the flooded fraction of a mascon basin approximately 900 kilometers in diameter.
Protein-Bacteriophage Conjugates: Application in Detection of Antibodies and Antigens
Authors: Haimovich Joseph , Sela Michael
Published: October 2006

Covalent attachment of proteins to bacteriophage yielded modified phage preparations with which it is possible to detect antibodies to proteins at concentrations as low as 0.5 to 2.0 nanograms per milliliter. Similarly, antibodies may be linked covalently to phage, and the resulting antibody-phage conjugate is useful in detecting proteins. An alternative method for quantitative determination of proteins is suggested, in which the inactivation of protein-phage by antibodies to protein is inhibited by the protein tested. With rabbit immunoglobulin G as the protein, as little as 0.3 nanogram per milliliter could be determined.
Extraoptic Phase Shifting of Circadian Locomotor Rhythm in Salamanders
Authors: Adler Kraig
Published: October 2006

Timing of locomotor rhythm in the slimy salamander,
Plethodon glutinosus
, can be shifted in phase by the environmental light cycle, whether the animals have eyes or not. Rhythmicity persists at least for the first day when animals are transferred to constant conditions, with a period of about 24 hours, and is therefore circadian in nature. An extraoptic photoreceptor site in the brain is suggested.
Centrioles of a Human Cancer: Intercellular Order and Intracellular Disorder
Authors: Schafer Paul W.
Published: October 2006

A continuous, symmetric, and periodic pattern of long-range spatial order has been observed among the centrioles of both normal and neoplastic cells. Consecutive ultrathin sections of lethal human esophageal cancers have revealed a defect in the centriolar angle with random angularity and random, long, intercentriolar distances.
2,3-
cis
-3,4-
trans
-3,4-Dihydroxy-L-proline: Mass Spectrometry and X-Ray Analysis
Authors: Karle Isabella L. , Daly John W. , Witkop Bernhard
Published: October 2006

Mass spectrometry showed the new amino acid from diatom cell walls to be a dihydroxyproline. X-ray analysis of the unmarked free amino acid by the use of the symbolic addition procedure revealed the complete three-dimensional structure as 2,3-
cis
-3,4-
trans
-3,4-dihydroxy-L-proline with carbon number 3 being 0.06 angstrom above the plane of the pyrrolidine ring.
Acetylcholine Receptor: Covalent Attachment of Depolarizing Groups at the Active Site
Authors: Silman Israel , Karlin Arthur
Published: October 2006

Following reduction of the acetylcholine receptor in the electroplax with dithiothreitol, the quaternary ammonium compounds bromoacetylcholine bromide and the
p
-nitrophenyl ester of (
p
-carboxyphenyl) trimethylammonium iodide react near the active site probably with a sulfhydryl group. The covalently attached quaternary ammonium moieties additionally interact with the active site noncovalently to activate the receptor and cause depolarization of the cell.
Waterfall-Generated Earth Vibrations
Authors: Rinehart John S.
Published: October 2006

Waterfalls generate periodic earth vibrations whose frequencies are inversely proportional to the height of the waterfall. Action of turbulent eddies is a probable explanation.
Strontium-90 Concentration Factors of Lake Plankton, Macrophytes, and Substrates
Authors: Kalnina Z. , Polikarpov G.
Published: October 2006

The ratio of concentration of strontium-90 in living and inert lake components to that in lake water (concentration factors) was determined for plankton, macrophytes, and substrates in eutrophic, mesotropric-eutrophic, and dystrophic Latgalian lakes. Concentration factors of strontium-90 in aquatic organisms and substrates are higher in a dystrophic lake than in the other types.
Neural Readout from Memory during Generalization
Authors: John E. R. , Shimokochi M. , Bartlett F.
Published: October 2006

Eight cats with implanted electrodes were trained to obtain food on presentation of one flicker frequency and to avoid shock on presentation of a second flicker frequency. A third flicker frequency, midway between the first and the second, was then presented. Differential generalization ensued, in which either the food response or the avoidance response was performed. Average evoked potentials from generalization trials with different outcomes were significantly different. The wave shape elicited by the stimulus for generalization closely resembled the usual response to the appropriate signal for the behavior which was displayed. This constitutes evidence for release of a neural process representing previous experience. The release of this process begins about 35 milliseconds after stimulation.
Aspirin: Its Effect on Platelet Glycolysis and Release of Adenosine Diphosphate
Authors: Doery J. C. G. , Hirsh J. , de Gruchy G. C.
Published: October 2006

Incubation of human platelets with aspirin inhibited glycolysis and produced a fall in the concentration of adenosine triphosphate. When platelets were exposed to collagen there was an increase in glycolysis and release of adenosine diphosphate. Prior incubation of the platelets with aspirin for 5 minutes did not totally suppress the increase in glycolysis after exposure to collagen but completely inhibited the collagen-induced reaction of the release of adenosine diphosphate. It is suggested that aspirin acts on human platelets by inhibiting both release of adenosine diphosphate and the transport of glucose across the platelet membrane.