bluuebunny/crossref_metadata_2025 huggingface dataset:
Color-Discrimination Performance of Pigeons: Effects of Reward
Authors: Boneau C. Alan , Holland Morris K. , Baker William M.
Published: October 2006

Performance of two pigeons given tasks in discriminating colors was examined on trials before and after they had occasionally received rewards for pecking when exposed to light of specific wavelengths. After a reward, the probability that the birds would respond to light stimuli that were never rewarded was higher than before the reward was given, but paradoxically the birds showed no general decline in their ability to differentiate between stimuli at wavelengths 1 millimicron apart.
Sands of the Mid-Atlantic Ridge
Authors: Fox Paul Jeffrey , Heezen Bruce C.
Published: October 2006

Sands collected at 24 locations along the crest of the Mid-Atlantic Ridge between 57°S and 38°N consist predominantly of olivine, diopsidic augite, hypersthene, enstatite, amphibole, quartz, plagioclase, and volcanic glass, suggesting an olivine tholeiitic source. Eight cores contain relatively pure mineral sands; three of these cores reflect local volcanic activity. In 16 cores the manganese-coated mineral grains are mixed in a current-winnowed foraminiferal sand or ooze.
Iodination in Relation to Thyroglobulin Maturation and Subunit Aggregation
Authors: Seed Randolph W. , Goldberg Irving H.
Published: October 2006

Noniodinated subunits of thyroglobulin can aggregate, but iodination of the aggregate is required for its stabilization (maturation). Rat-thyroid slices incorporate amino acids into subunits, but cannot form mature thyroglobulin from the newly synthesized subunits. This defect leads to an accumulation of 16
S
and 12
S
proteins, although the preexisting thyroglobulin is 19
S
. Accumulation of 16
S
and 12
S
proteins can be produced in rat thyroids by the administration to the animals of a thiocarbamide derivative, methimazole. Upon withdrawal of methimazole, iodination of the 16
S
and 12
S
proteins proceeds, and 19
S
protein appears.
Fatty-Tissue Changes in Rats with Acclimatization to Altitude
Authors: Blatteis Clark M. , Lutherer Lorenz O.
Published: October 2006

Adipose tissue in the adult white rat changes in both quantity and histologic characteristics during a 5-week period of acclimatization to a simulated altitude of 4350 meters at 26°C. These findings are descriptive and do not at present permit conclusions as to the mechanisms involved.
Terrestrial Heat Flow: Measurement in Lake Bottoms
Authors: Hart S. R. , Steinhart J. S.
Published: October 2006

The feasibility of measuring terrestrial heat flow in lakes has been investigated in Lake Superior. The temperature gradient and thermal conductivity of the sediment were measured at each of four stations in water depths exceeding 250 meters. Consideration of the effects of climatic variations suggests that they may not seriously affect the values for heat flow obtained by this method. The values measured are in reasonable agreement with other continental values in the shield areas.
Immunosuppression in Vivo by a Soluble Form of the CTLA-4 T Cell Activation Molecule
Authors: Linsley Peter S. , Wallace Philip M. , Johnson Jennifer , Gibson Marylou G. , Greene JoAnne L. , Ledbetter Jeffrey A. , Singh Cherry , Tepper Mark A.
Published: October 2006

In vitro, when the B7 molecule on the surface of antigen-presenting cells binds to the T cell surface molecules CD28 and CTLA-4, a costimulatory signal for T cell activation is generated. CTLA4Ig is a soluble form of the extracellular domain of CTLA-4 and binds B7 with high avidity. CTLA4Ig treatment in vivo suppressed T cell-dependent antibody responses to sheep erythrocytes or keyhole limpet hemocyanin. Large doses of CTLA4Ig suppressed responses to a second immunization. Thus, costimulation by B7 is important for humoral immune responses in vivo, and interference with costimulation may be useful for treatment of antibody-mediated autoimmune disease.
Anomalous Dispersion Method: Its Power for Protein Structure Analysis
Authors: Ramachandran G. N. , Parthasarathy S.
Published: October 2006

The phases of x-ray reflection of a crystal can be measured, except for an ambiguity, if the crystal contains heavy atoms which scatter x-rays anomalously. Theoretical studies show that the method of resolving this ambiguity by choosing the phases closer to those of the heavy atoms has a good potentiality for solving complicated structures, in which the average heavy atom contribution to the intensity is as low as 10 percent.
Delta-Aminolevulinate Dehydratase Activity in Mice with Hereditary Anemia
Authors: Margolis Frank L. , Russell Elizabeth S.
Published: October 2006

Homozygous (
f
/
f
) but not heterozygous (
f
/+) mice of the highly congenic strain, FL/ Re, manifest a severe transitory siderocytic fetal anemia. Adults of both
f
/
f
and
f
/+ genotype manifest decreased hepatic, splenic, and renal levels of Δ-aminolevulinate dehydratase (ALD) activity compared to homozygous (+/+) mice of the same strain. The degree of augmentation in splenic ALD activity following phenylhydrazine administration is high in +/+, intermediate in
f
/+, and low in
f
/
f
mice. These findings suggest that perhaps a deficiency in the fetal level of ALD may be responsible for the transitory fetal anemia.
Fast Reactions of Ascorbic Acid and Hydrogen Peroxide in Ice, a Presumptive Early Environment
Authors: Grant Norman H. , Alburn Harvey E.
Published: October 2006

Nonenzymatic decomposition of hydrogen peroxide proceeded more rapidly in ice than in liquid water. At 5 × 10
-7
M
ferric chloride or 10
-8
M
cupric chloride, breakdown of hydrogen peroxide was significant at -11° and -18° but negligible at +1°C. Ascorbic acid oxidation was faster in ice both with or without added metal ion. Nonparallel effects of metals and
p
H indicate mechanism changes in ice.
Culture of a Planktonic Calanoid Copepod through Multiple Generations
Authors: Zillioux Edward J. , Wilson Donald F.
Published: October 2006

Acartia tonsa
has been propagated through 12 filial generations during 1 year in small laboratory cultures. The mean generation time was 25 days at 17°C on a slightly suboptimum, mixed algal diet. Body size, reproductive capacity, and generation time were unchanged during the culture period.
Antagonism of Purified Asparaginase from Guinea Pig Serum toward Lymphoma
Authors: Yellin Tobias O. , Wriston John C.
Published: October 2006

The tumor inhibitory activity of highly purified asparaginase from guinea pig serum toward the Gardner lymphosarcoma in C3H mice was compared with that of the serum itself. The purified enzyme, homogeneous by ultracentrifugation and immunoelectrophoresis, had activity comparable to that of the serum. The serum was also effective in mice which were made immunologically incompetent by radiation with cobalt-60.
Effects of Electroshock on Memory: Amnesia without Convulsions
Authors: McGaugh James L. , Alpern Herbert P.
Published: October 2006

Mice received a single training trial on an inhibitory avoidance task and a retention trial 24 hours later. Electroshock stimulation, administered 25 seconds after the training trial, produced amnesia even if the convulsion was prevented by ether anesthesia. The amnesia produced by such shock is apparently due to the electric current and not to the convulsion.
Strontium-90 Fallout from Surface and Underground Nuclear Tests
Authors: Sotobayashi Takeshi , Koyama Seitaro
Published: October 2006

Deposition of strontium-90 per unit area per unit fission energy from surface blast of the first Chinese atomic bomb was several times heavier than that from an earlier atmospheric test series. The venting of a Russian large-scale underground test also significantly increased deposition of strontium-90 at Niigata, Japan.
Growth-Hormone Deficiency in Man: An Isolated, Recessively Inherited Defect
Authors: Rimoin David L. , Merimee Thomas J. , McKusick Victor A.
Published: October 2006

A deficiency of human growth hormone not associated with other pituitary deficiencies was observed in midgets with sexual ateliosis, a form of dwarfism inherited as an autosomal recessive trait. Body proportions, sexual development, birth weight, and postpartum lactation are normal in this syndrome.
Ambrosia Fungi: Extent of Specificity to Ambrosia Beetles
Authors: Batra Lekh R.
Published: October 2006

Experiments with developing ambrosia beetles and fungi indicate that beetles may feed on more than one species growing in their tunnels. The yeast-like ambrosia propagules in mycangia of beetles arise from conida and ascospores picked up by callow adults during their stay in tunnels.
Ethics for an International Health Profession
Authors: Taylor Carl E.
Published: October 2006

These thoughts about an ethic of international health can be summarized in a very free revision of the Hippocratic Oath:

I will share the science and art by precept, by demonstration, and by every mode of teaching with other physicians regardless of their national origin. I will try to help secure for the physicians in each country the esteem of their own people, and in collaborative work see that they get full credit.

I will strive to eliminate sources of disease everywhere in the world and not merely set up barriers to the spread of disease to my own people.

I will work for understanding of the diverse causes of disease, including the social, economic, and environmental. I will promote the well-being of mankind in all its aspects, not merely the bodily, with sympathy and consideration for a people's culture and beliefs.

I will strive to prevent painful and untimely death, and also to help parents to achieve a family size conforming to their desires and to their ability to care for their children. In my concern with whole communities I will never forget the needs of its individual members.
Surface Area of Human Erythrocyte Lipids: Reinvestigation of Experiments on Plasma Membrane
Authors: Bar Robert S. , Deamer David W. , Cornwell David G.
Published: October 2006

Ratios of the lipid monolayer area to the erythrocyte surface area are 2:1 at low surface pressures and approach 1: 1 at collapse pressures. Unsaturated phospholipids in cholesterol-phospholipid complexes of membrane extracts resemble their saturated derivatives at collapse pressures. Area ratio and phospholipid area data are related by an equation that tests hypothetical values for molecular areas used in membrane models.
Structure of Biological Membranes
Authors: Korn Edward D.
Published: October 2006

The combined x-ray diffraction and electron microscopic examination of myelin has provided reasonable, but not conclusive, support for its structure as a basically bimolecular leaflet of phospholipid that is partially interspersed with protein. But there is very little basis for extending this concept to biological membranes in general. There is no adequate experimental support for the specific orientation of phospholipids as proposed in the unit membrane theory or for the proposed polar nature of protein-lipid bonds, even in myelin. Membranes differ widely in chemical composition, metabolism, function, enzymatic composition, and even in their electron microscopic image. The only similarity is their general resemblance in electron micrographs, but, until more is known about the chemistry of electron microscopy, this evidence cannot be interpreted with confidence. One positive conclusion to which I have come is that much more chemical evidence must, and can, be obtained. Techniques for the isolation of membranes are improving and protein and lipid chemistry are now highly refined arts. Quantitative analysis of many different membranes is possible and the data can be related in some instances, notably bacterial plasma membranes, to calculations of surface area. Chemical and physical changes induced in membranes of widely different lipid composition by the preparatory procedures of electron microscopy can be determined directly and correlated with the electron microscopic image. Model systems can be assembled whose compositions closely resemble those of biological membranes. Membranes can be disassociated into subunits whose properties can be studied. In particular, x-ray diffraction analysis and electron microscopy by negative staining of reaggregates of lipoproteins isolated from membranes would be very informative. Perhaps most important, the problem of membrane structure must be considered in relation to the problems of membrane function and membrane biosynthesis.
Synapses of Horizontal Cells in Rabbit and Cat Retinas
Authors: Dowling John E. , Brown Joel E. , Major Diane
Published: October 2006

Horizontal cells in the retinas of cats and rabbits are morphologically similar; in both species, two types can be distinguished in Golgi-stained material. Horizontal cells and their processes are readily recognized in electron micrographs, and many of the horizontal cell processes appear to make synaptic contacts with dendrites and somata of bipolar cells, and probably with other horizontal cells. The synapses of the horizontal cell appear similar to chemical synaptic contacts described throughout the nervous system. With the finding of synaptic contacts, it seems clear that retinal horizontal cells should be classified as neurons.
Spermatophore Web Formation in a Pseudoscorpion
Authors: Weygoldt Peter
Published: October 2006

The male pseudoscorpion
Serianus
sp. n. deposits spermatophores without mating, but only when females are present. It marks a path to the spermatophore with silken threads produced in an endodermal gland, which is homologous to the rectal pocket in males and females of other species and in the female of the same species.
Molybdenum Diselenide: Rhombohedral High Pressure-High Temperature Polymorph
Authors: Towle Laird C. , Oberbeck Verne , Brown† Bruce E. , Stajdohar Ralph E.
Published: October 2006

A three-layered rhombohedral form of molybdenum diselenide has been produced by subjecting the normal two-layered hexagonal form to pressures of 40 kilobars and temperatures of 1500°C. The new form is isostructural with rhombohedral molybdenum disulfide.
Melting of Tin Telluride at High Pressures
Authors: Klement William , Cohen Lewis H.
Published: October 2006

The melting curve of tin telluride (Sn
0.496
Te
0.504
) was determined by differential thermal analysis at pressures between 5 and 40 kilobars. Near 844° ± 4°C and 12.0 ± 1.0 kb, the liquid and two solid polymorphs coexist.
Holomicrography: Transformation of Image during Reconstruction a posteriori
Authors: Ellis Gordon W.
Published: October 2006

Holomicrographs recorded through a microscope contain a hologram of the interior of the microscope, including the objective. During reconstruction of the microscopic image, modification of the aperture of the reconstructed objective produces the same alteration in the reconstructed image that would have occurred in the original image, if the actual objective had received the same modification. By this means, a single event holographed by bright-field microscopy may later be examined in reconstruction by dark-field, phase-contrast, or interference microscopy.
Evidence from Cultured Leucocytes of Blood Cell Chimerism in Ex-Parabiotic Frogs
Authors: Volpe E. Peter , Gebhardt Bryan M.
Published: October 2006

Postmetamorphic diploid and triploid frogs that had earlier been joined in parabiotic union from embryonic life until metamorphosis were each found to be chimeric with respect to their blood cells, as revealed in chromosome preparations of cultured leucocytes. Blood cells precursors most likely were interchanged when the ex-parabionts shared a common circulation in embryonic life, and the exchanged precursor cells apparently homed in the hematopoietic tissues of the hosts. The tolerance which exparabiotic pairs of frogs exhibit toward grafts of each other's skin is attributable to the blood cell chimerism.
Simple Photoreceptors in
Limulus polyphemus
Authors: Millecchia Ronald , Bradbury Jack , Mauro Alexander
Published: October 2006

The "olfactory nerve," the endoparietal eye, and the rudimentary lateral eyes of Limulus (polyphemus) contain simple photoreceptor cells that duplicate many of the electrical responses of the retinular cells of the lateral eye; the responses are a receptor potential consisting of an initial transient phase and a subsequent steady phase, low-amplitude fluctuations, and a small locally regenerative response to pulses of both light and current. Photic stimulation does not induce conducted action potentials, but does increase the membrane conductance. The receptor potential requires the presence of sodium ions in the external medium. Measurements of action and absorption spectra indicate a photopigment whose maximum absorption is of light with wavelength of 535 nanometers. The functional significance of these cells has not been ascertained.
Stimulated Brillouin and Raman Scattering in Quartz at 2.1° to 293° Kelvin
Authors: Tannenwald P. E. , Thaxter J. B.
Published: October 2006

Stimulated Brillouin shifts observed at 2.1°K in quartz are the same as those observed at 293°K. No extreme nonlinear behavior is observed. Recent anomalous results reported by Russian workers are shown to be due to the very strong stimulated Raman scattering that sets in at low temperatures.
Ozone-Induced Chemiluminescence of Organic Compounds
Authors: Bowman Robert L. , Alexander Nelson
Published: October 2006

Chemiluminescence was observed when organic compounds in a dry state, as well as in organic solvents, were exposed to ozone in oxygen. The peak intensity of the light emission is related quantitatively to the amount of compound. Many compounds can be identified by this method, and some are listed. Sensitivity of detection approximates that of fluorescence methods and extends to less-than-nanogram quantities for some compounds. Ozone-induced chemiluminescence of compounds in acetone solution was less sensitive than it was in the dry analysis.
Background Selections of Geometrid and Noctuid Moths
Authors: Sargent T. D
Published: October 2006

Several common moths, collected at night and placed in an experimental box, showed daytime selections of backgrounds which tended to match the reflectance of their forewings. In one case, two distinct forms of a species showed different background selections.
Natural Displacement of Pollution from the Great Lakes
Authors: Rainey Robert H.
Published: October 2006

A simplified mathematical model of a lake system indicates that, if the pollution of the Great Lakes were discontinued, the natural flow through the lower Great Lakes would be sufficient to remove about 90 percent of the waste in about 20 years. On the other hand, hundreds of years would be required to displace the pollution from Lake Michigan and Lake Superior.
Stereoscan Electron Microscopy of Soil Microorganisms
Authors: Gray T. R. G.
Published: October 2006

Details of the surface structure of microorganisms growing in soil and the complex topography of individual soil particles were observed with the Stereoscan electron microscope. Because it was not necessary to remove the microorganisms from the soil particles, it was possible to establish their occurrence in different microhabitats. This technique can provide useful ecological information about the soil microflora.
Artifact Produced in Disc Electrophoresis by Ammonium Persulfate
Authors: Brewer John M.
Published: October 2006

Ammonium persulfate, a common polymerizing agent for acrylamide gels, can inactivate yeast enolase and produce increased electrophoretic heterogeneity during disc electrophoresis in gels containing 8
M
urea. The use of riboflavin and light for polymerization or thioglycolate for removal of the persulfate are feasible alternatives.
Quinacrine (Atebrin): Mode of Action
Authors: Ciak Jennie , Hahn Fred E.
Published: October 2006

Quinacrine at a concentration of 8 × 10
-4
mole per liter is bactericidal for
Escherichia coli
, blocks DNA synthesis, and inhibits the syntheses of RNA and protein strongly. At a concentration of 2 × 10
-4
mole per liter, the drug is bacteriostatic, the syntheses of protein and DNA (but not that of RNA) are partially inhibited, and the bacteria grow into giant filaments. Impairment of DNA replication is proposed as the mode of action of quinacrine.
Irradiation Effects in Glasses: Suppression by Synthesis under High-Pressure Hydrogen
Authors: Faile S. P. , Schmidt J. J. , Roy D. M.
Published: October 2006

Glasses synthesized under high pressure of hydrogen showed resistance to certain effects of irradiation. Paramagnetic and light-absorption effects associated with irradiated glasses were diminished by a factor as large as 20 in some glasses. Irradiation increases the concentration of hydroxyl ions, as evidenced by increased absorption in the 2.7-micron (3700 cm
-1
) infrared region for hydrogen-silica glasses.
Recurrent Herpes in the Rabbit and Man
Authors: Kaufman Herbert E. , Brown David C. , Ellison Emily Maloney
Published: October 2006

Herpesvirus was present in secretory glands and frequently in tears of rabbits with recurrent herpetic keratitis even in the absence of corneal lesions. In normal people, herpesvirus could be cultured from saliva and tears. Chronic virus multiplication in structures such as the lacrimal and salivary glands, rather than latency, may cause recurrent herpetic disease.
Photoperiodic Control of the Cloacal Gland of the Japanese Quail
Authors: Sachs Benjamin D.
Published: October 2006

Changes in photoperiod cause correlated changes in testes, cloacal glands, cloacal foam, and reproductive behavior of male Japanese quail. The cloacal protrusion may serve as a convenient external index of androgen, permitting repeated measurement without operation on or killing of the animal.
The First Mesozoic Ants
Authors: Wilson Edward O. , Carpenter Frank M. , Brown William L.
Published: October 2006

Two worker ants preserved in amber of Upper Cretaceous age have been found in New Jersey. They are the first undisputed remains of social insects of Mesozoic age, extending the existence of social life in insects back to approximately 100 million years. They are also the earliest known fossils that can be assigned with certainty to aculeate Hymenoptera. The species,
Sphecomyrma freyi
, is considered to represent a new subfamily (Sphecomyrminae), more primitive than any previously known ant group. It forms a near-perfect link between certain nonsocial tiphiid wasps and the most primitive myrmecioid ants.
Splashing of Drops on Shallow Liquids
Authors: Hobbs P. V. , Osheroff T.
Published: October 2006

The events that follow the splashing of a drop on a liquid depend on the depth of the liquid. When the depth is less than about 5 millimeters the crown that is ejected is more unstable than that from a splash on a deep liquid. As the depth is decreased from 25 to 7 millimeters, there is an increase in the maximum height to which the Rayleigh jet rises, and in the number of drops that break away from the jet. With depths less than 7 millimeters these two quantities fall off sharply, and no jet drops are produced for depths less than about 3 millimeters.
Discrepancies between Viscosity Data for Simple Gases
Authors: Hanley H. J. M. , Childs G. E.
Published: October 2006

It has been known for some time that Kestin and his co-workers have reported dilute gas viscosity coefficients which differ from the usually accepted values. Recent work from the Los Alamos Scientific Laboratory supplements Kestin's results. We show that there is no evidence for not accepting this different data. We feel that the whole subject of dilute gas viscosity measurements above room temperature should be reexamined both from the experimenter's and correlater's viewpoints. There is evidence that published tables may be incorrect by as much as 10 percent above 600°K.
Human Hormone Production in vitro
Authors: Pattillo Roland A. , Gey George O. , Delfs Eleanor , Mattingly Richard F.
Published: October 2006

A new in vitro hormone-synthesizing cell system, line BeWO, derived from human gestational choriocarcinoma, has been permanently established; a high degree of synthesis of functional hormone has been maintained for 18 months in tissue culture. Predominantly glycolytic metabolism, dependent on the level of glucose in the medium, has been observed. Many facets of placental and tumor-cell metabolism, growth, and differentiation are found in this unique multipotential cell.
A Transcriptional Enhancer Whose Function Imposes a Requirement That Proteins Track Along DNA
Authors: Herendeen Daniel R. , Kassavetis George A. , Geiduschek E. Peter
Published: October 2006

Transcriptional regulation of the bacteriophage T4 late genes requires the participation of three DNA polymerase accessory proteins that are encoded by T4 genes 44, 62, and 45, and that act at an enhancer-like site. Transcriptional activation by these DNA replication proteins also requires the function of an RNA polymerase-bound coactivator protein that is encoded by T4 gene 33 and a promoter recognition protein that is encoded by T4 gene 55. Transcriptional activation in DNA constructs, in which the enhancer and a T4 late promoter can be segregated on two rings of a DNA catenane, has now been analyzed. The ability of an interposed DNA-binding protein to affect communication between the enhancer and the promoter was also examined. Together, these experiments demonstrate that this transcription-activating signal is conveyed between its enhancer and a T4 late promoter by a DNA-tracking mechanism. Alternative activation mechanisms relying entirely on through-space interactions of enhancer-bound and promoter-bound proteins are excluded.
Flicker Fusion Phenomena
Authors: Levinson John Z.
Published: October 2006

The high-frequency temporal behavior of the human visual system has been shown to have some of the properties of a linear low-pass filter. For such a system it is appropriate to consider a repetitive stimulus as having separable Fourier harmonic components. The direct-current component or average luminance is important in that it sets the adaptation level. It is therefore convenient to keep it constant when varying other stimulus parameters, such as frequency or wave form. Of the alternating-current components, only the fundamental is important at high frequencies, the higher harmonics being relatively more attenuated.

Any linear low-pass filter system responds in a predictable way to sinusoidal stimulation, whether continuous or of short duration. In the case of the visual system, predictable behavior is found at high frequencies, and it leads to discovery of hitherto unobserved pseudoflash and real flash phenomena. Measurement of a new characteristic time is suggested.

At low frequencies the use of half- and whole-sinusoidal flashes leads to the discovery of some interesting relations with flicker thresholds, but these remain for future discussion.
Proton Radiography
Authors: Koehler A. M.
Published: October 2006

Energetic protons from an accelerator may be used to produce radiographs showing unusually high contrast but relatively poor spatial resolution.
Cross-link in Fibrin Polymerized by Factor XIII: ε-(γ-Glutamyl)lysine
Authors: Pisano J. J. , Finlayson J. S. , Peyton Marjorie P.
Published: October 2006

ε-(γ-Glutamyl)lysine has been isolated from enzymatic hydrolyzates of cross-linked human fibrin. This compound was not detected in "non-cross-linked" fibrin prepared with ethylenediaminetetraacetic acid, which inhibits factor XIII; intermediate amounts were observed when the fibrin was prepared with glycine ethyl ester, which inhibits factor XIII competitively. These and ancillary experiments furnish conclusive evidence that ε-(γ-glutamyl)lysine cross-links form in human fibrin during polymerization catalyzed by factor XIII.
Haptoglobin and Catalase Loci in Man: Possible Genetic Linkage
Authors: Nance Walter E. , Empson Judith E. , Bennett Thomas W. , Larson Larry
Published: October 2006

Slow- and fast-migrating electrophoretic variants of human erythrocyte catalase were encountered in four of approximately 200 families. Tests for nine genetic polymorphisms provided evidence suggesting linkage only in the case of the haptoglobin system.
Dissociation of Bradycardia and Arterial Constriction during Diving in the Seal
Phoca vitulina
Authors: Murdaugh H. V. , Cross Carroll E. , Millen J. Eugene , Gee J. Bernard L. , Robin Eugene D.
Published: October 2006

Bradycardia associated with diving in the harbor seal has been dissociated from the arterial constrictor response by intracardiac pacing. Development of arterial constriction does not depend upon the development of bradycardia. During pacing, arterial constriction continues in the absence of bradycardia. Increases in heart rate to values greater than 120 beats per minute during a dive produce a progressive decrease in mean aortic pressure, which suggests that one major function of bradycardia is to reduce cardiac output, thus matching left ventricular output to the restricted vascular bed and decreased venous return associated with diving.
Alcohol and Amitriptyline Effects on Skills Related to Driving Behavior
Authors: Landauer Ali A. , Milner Gerald , Patman Joanna
Published: October 2006

Three motor-skill tests related to driving ability were given to 21 healthy young volunteers after administration of various combinations of amitriptyline, placebo, and alcohol. It was found that the tricylic antidepressant added to the deleterious effects of alcohol.
Honey Bee Recruitment to Food Sources: Olfaction or Language?
Authors: Wenner Adrian M. , Wells Patrick H. , Johnson Dennis L.
Published: October 2006

Honey bee recruits locate food sources by olfaction and not by use of distance and direction information contained in the recruitment dance. Recruitment efficiency increases as odor of the food source accumulates in the hive, from hour to hour and from day to day. Flight patterns, landing patterns, bee odor, and Nassanoff secretion apparently do not aid in recruitment of bees.
Metal Ion Activation of Phosphate Transfer by Bidentate Coordination
Authors: Farrell Francis J. , Kjellstrom William A. , Spiro Thomas G.
Published: October 2006

The hydrolysis of methyl phosphate bound to the triethylenetetramine-cobalt(III) ion is much faster than the hydrolysis of either dimethyl phosphate bound to the same cation or methyl phosphate bound to the pentamminecobalt-(III) ion. The rate enhancement is attributed to bidenate coordination of the methyl phosphate. This feature suggests a pseudorotation mechanism analogous to that proposed by Westheimer for the hydrolysis of ethylene methyl phosphate. Stabilization of bidentate coordination might play a role in metal ion activation of phosphate-transfer enzymes.
Complex Synaptic Configurations in Planarian Brain
Authors: Best J. B. , Noel J.
Published: October 2006

Complex synaptic configurations which appear to have especial evolutionary and functional significance are shown in the neuropil of the brain of the planarian
Dugesia dorotocephala
. Some of the endings in these synaptic attachments contain dense core vesicles, suggesting that nonadrenaline or serotonin or both are neurotransmitters at a more primitive phyletic level than reported hitherto. The spatial proximity and connectivity of the synapses suggest modes of action permitting greater functional complexity to the planarian brain than previously supposed. Closely adjacent cellular processes which contain polysomal ribosomes, unusual in the neuropil, suggest synaptic transmission-protein synthesis coupling and a possible role in memory.
Human Ooeytes: Maturation in Chemically Defined Media
Authors: Kennedy Joseph F. , Donahue Roger P.
Published: October 2006

Human oocytes from ovarian follicles resume meiosis in F10, a defined medium, in numbers comparable to that obtained in medium containing serum. Several simple Krebs-Ringer media also support maturation, which suggests a similarity of nutritional requirements between human and mouse oocytes. Fewer oocytes reach metaphase II when the investing follicular cells are removed prior to culture.
Hyperpolarizing and Depolarizing Receptor Potentials in the Scallop Eye
Authors: Gorman Anthony L. F. , McReynolds John S.
Published: October 2006

Depolarizing and hyperpolarizing responses to light were recorded intracellularly from different cells in the scallop retina. Both types of potentials appear to be primary effects of light on photoreceptor cells.
Similar Neuronal Alterations Induced by Axonal Injury And Learning in
Aplysia
Authors: Walters Edgar T. , Alizadeh Hassan , Castro Gilbert A.
Published: October 2006

Learning in the marine mollusk
Aplysia
has been associated with enhanced sensory function, expressed in mechanosensory neurons as (i) decreases in action potential threshold, accommodation, and afterhyperpolarization, and (ii) increases in action potential duration, afterdischarge, and synaptic transmission. These alterations also occur, with a delay, after sensory axons are injured under conditions in which synaptic transmission is severely reduced. The latency and specificity of injury-induced alterations indicate that induction signals are generated at the site of injury and conveyed centrally by axonal transport. Similarities in neuronal modifications support the hypothesis that some memory mechanisms evolved from mechanisms of injury-induced sensory compensation and repair.
Subsurface Phenomena and the Splashing of Drops on Shallow Liquids
Authors: Macklin W. C. , Hobbs P. V.
Published: October 2006

High-speed movies have been taken of the formation of the subsurface cavity and of the Rayleigh jet formed during the splash of a drop on a shallow liquid. They show that the initial increase and subsequent decrease in the rate of rise of the jet and the maximum jet height with decreasing depth of liquid are the result of the interaction of the subsurface cavity with the solid boundary beneath the liquid. This interaction modifies considerably the pressure gradients in the liquid during the formation and collapse of the cavity.
Lysergic Acid Diethylamide: Role in Conversion of Plasma Tryptophan to Brain Serotonin (5-Hydroxytryptamine)
Authors: Lin Robert C. , Ngai S. H. , Costa E.
Published: October 2006

Injections of D-lysergic acid diethylamide decrease the turnover rate of 5-hydroxytryptamine of rat brain, as measured from the conversion of
14
C-tryptophan into
14
C-5-hydroxytryptamine. The 2-bromolysergic acid diethylamide given in doses fivefold greater than those of lysergic acid diethylamide fails to change the rate of
14
C-tryptophan conversion into
14
C-5-hydroxytryptamine. The effect of D-lysergic acid diethylamide is discussed with regard to its action on brain serotonergic neurons and its psychotomimetic effects.
Regenerative Calcium Release within Muscle Cells
Authors: Ford Lincoln E. , Podolsky Richard J.
Published: October 2006

Free calcium appears to trigger the release of stored calcium from the sarcoplasmic reticulum of skinned skeletal muscle fibers immersed in solutions with a low concentration of magnesium ion.
Rhodanine: A Selective Inhibitor of the Multiplication of Echovirus 12
Authors: Eggers Hans J. , Koch M. A. , Furst Arthur , Daves G. Doyle , Wilczynski Joseph J. , Folkers Karl
Published: October 2006

A search for compounds which have previously unrecognized antiviral activity led to the discovery that rhodanine inhibits the multiplication of echovirus 12 and also the development of virus-induced morphologic changes. Eighteen derivatives and analogs of rhodanine were synthesized and tested against echovirus 12. These compounds were considerably less active than rhodanine or were inactive, and some of them were more toxic to the host cells than rhodanine.
Concentration and Isotopic Composition of Carbon and Sulfur in Apollo 11 Lunar Samples
Authors: Kaplan I. R. , Smith J. W.
Published: October 2006

The concentration of carbon and sulfur in six samples ranged between 20 to 200 and 650 to 2300 parts per million, respectively. Carbon was present in gaseous, volatilizable, and nonvolatile forms, and terrestrial contaminants were recognized. Sulfur appeared to exist only as acid-volatile sulfide. The bulk fines contain a high concentration of carbon and a low concentration of sulfur. They are always enriched in the heavier isotope carbon-13 or sulfur-34. The fine-grained basaltic rocks show the reverse relation; lowest carbon, highest sulfide concentrations, and no apparent enrichment in heavy isotopes. The breccias are of intermediate composition.
Lunar Organic Compounds: Search and Characterization
Authors: Burlingame A. L. , Calvin Melvin , Han J. , Henderson W. , Reed W. , Simoneit B. R.
Published: October 2006

The carbon concentration in Apollo 11 lunar fine material is of the order of 200 ppm. By far the largest single amount of this carbon appears to be in carbon monoxide. Some of this seems to be in the form of gas bubbles in the glass spheres, but most of it could be in some complex form other than gas. This result would be consistent with the idea that most of the fines passed through a high temperature and that the carbon was oxidized by mineral oxides at that time.
Radio-Frequency Thrombosis of Vascular Malformations with a Transvascular Magnetic Catheter
Authors: Taren James A. , Gabrielsen Trygve O.
Published: October 2006

A tiny magnetic electrode catheter introduced into the human carotid artery has been mechanically and magnetically propelled, with fluoroscopic control, to cranial arteriovenous malformations. Radio-frequency heating of the catheter tip in successive positions occludes abnormal blood vessels.
Alkaloid from Fire Ant Venom: Identification and Synthesis
Authors: MacConnell John G. , Blum Murray S. , Fales Henry M.
Published: October 2006

An alkaloid,
trans
-2-methyl-6-
n
-undecylpiperidine (solenopsin A), has been isolated from the venom of the fire ant
Solenopsis saevissima
. The structure has been confirmed by an unambiguous synthesis.
Chemical Inducers of Oviposition for the Corn Earworm,
Heliothis zea
(Boddie)
Authors: Jones Richard L. , Burton Robert L. , Bowman Malcolm C. , Beroza Morton
Published: October 2006

The corn earworm moth lays its eggs in the vicinity of triacetin, an ingredient of felt-tipped marking pens. Related compounds also induce this behavior. A bioassay was devised to measure the activity of chemicals as oviposition inducers.
Pyrrhotites: Stoichiometric Compounds with Composition Fe

n
-1

S

n

(
n
≥ 8)
Authors: Morimoto Nobuo , Nakazawa Hiromoto , Nishigucmi Katsuhisa , Tokonami Masayasu
Published: October 2006

A new type of natural pyrrhotite, orthorhombic 11
C
type (
a
= 6.892,
b
= 11.952,
c
= 5.744 × 11 angstroms), and the hexagonal 6
C
type (
a
= 6.89,
c
= 5.76 × 6 angstroms) are described. Their compositions are Fe
10
S
11
and Fe
11
S
12
, respectively. Pyrrhotites stable in nature have essentially stoichiometric composition, Fe

n
-1

S

n

(
n
≥ 8), with the structures of
n
/2
C
type for
n
even and of
n
C
type for
n
odd. The solid solutions between Fe
11
S
12
and Fe
10
S
11
, and between Fe
10
S
11
and Fe
9
S
10
are considered metastable in nature.
Lymphocytic Responses to Streptococcal Antigens in Glomerulonephritic Patients
Authors: Zabriskie J. B. , Lewshenia R. , Möller G. , Wehle B. , Falk R. E.
Published: October 2006

The lymphocytes from patients with progressive glomerulonephritis showed significant inhibition of cell migration in the presence of group A streptococcal particulate antigens. Marked increases in the level of DNA synthesis of these lymphocytes were also observed after contact with these antigens. Lymphocytes from patients with unrelated renal disorders exhibited minimum reactivity to streptococcal antigens.
Morphine: Radioimmunoassay
Authors: Spector Sydney , Parker Charles W.
Published: October 2006

The development of a radioimmunoassay for morphine is described. The hapten morphine is made antigenic by coupling it to a protein at the phenolic group of the molecule. Extremely low concentrations of morphine (0.5 nanogram) can be measured by this assay procedure.
Density-Modulus Relationship in Graphite Fibers Made from Acrylic Yarns
Authors: Ezekiel Herbert M.
Published: October 2006

Three types of polyacrylonitrile yarn were converted to graphite fibers. There was a linear relation between density and Young's modulus of the graphite fibers, the ranges observed being 1.58 to 2.18 grams per cubic centimeter and 25 to 112 × 10
6
pounds per square inch.
Chemical Basis of Hashish Activity
Authors: Mechoulam Raphael , Shani Arnon , Edery Habib , Grunfeld Yona
Published: October 2006

A sample of hashish was extracted consecutively with petroleum ether, benzene, and methanol. When tested intravenously in monkeys only the petroleum-ether fraction was active. This material was further fractionated. The only active compound isolated was Δ
1
-tetrahydrocannabinol. Cannabinol, cannabidiol, cannabichromene, cannabigerol, and cannabicyclol when administered together with Δ
1
-tetrahydrocannabinol do not cause a change in the activity of the latter, under the experimental conditions used. These results provide evidence that, except for Δ
1
-tetrahydrocannabinol, no other major, psychotomimetically active compounds are present in hashish.
Brain Weight Increases Resulting from Environmental Enrichment: A Directional Dominance in Mice
Authors: Henderson Norman D.
Published: October 2006

A genetic analysis of brain weights of 544 mice reared in either enriched or standard laboratory environments indicated significant directional dominance in the percentage of increase in brain weight as a result of enrichment.
Infrared Emission Spectra: Enhancement of Diagnostic Features by the Lunar Environment
Authors: Logan Lloyd M. , Hunt Graham R.
Published: October 2006

Information diagnostic of general rock type is available as a well-defined emission maximum (related to the Christiansen frequency), rather than as contrast-depleted minima, in the infrared spectra of particulate solids. The amount of spectral information varies directly with the sharpness of the thermal gradient at the sample surface. Lunar thermal conditions optimize this gradient, making the moon an excellent target for remote sensing.
"Sex Ratio" in
Drosophila pseudoobscura
: Spermiogenic Failure
Authors: Policansky David , Ellison John
Published: October 2006

Contrary to earlier reports, testes of "sex ratio"
Drosophila pseudoobscura
males have only half as many sperm per bundle as testes of normal males do. This fact, determined from electron micrographs, indicates that the functional pole hypothesis is not applicable to the action of "sex ratio."
Splash of a Waterdrop at Terminal Velocity
Authors: Mutchler Calvin K. , Hansen Lyle M.
Published: October 2006

High-speed movies of splash formation caused by waterdrop impact at terminal velocity in thin water layers show that splash size increases with drop size. For increasing water depth, splash size increases to a maximum at a depth of one-third drop diameter; splash size then decreases to a constant size for depths greater than three drop diameters.
Crystal Structure of the Ribonuclease H Domain of HIV-1 Reverse Transcriptase
Authors: Davies Jay F. , Hostomska Zuzana , Hostomsky Zdenek , Jordan Steven R. , Matthews David A.
Published: October 2006

The crystal structure of the ribonuclease (RNase) H domain of HIV-1 reverse transcriptase (RT) has been determined at a resolution of 2.4 Å and refined to a crystallographic
R
factor of 0.20. The protein folds into a five-stranded mixed beta sheet flanked by an asymmetric distribution of four alpha helices. Two divalent metal cations bind in the active site surrounded by a cluster of four conserved acidic amino acid residues. The overall structure is similar in most respects to the RNase H from
Escherichia coli
. Structural features characteristic of the retroviral protein suggest how it may interface with the DNA polymerase domain of p66 in the mature RT heterodimer. These features also offer insights into why the isolated RNase H domain is catalytically inactive but when combined in vitro with the isolated p51 domain of RT RNase H activity can be reconstituted. Surprisingly, the peptide bond cleaved by HIV-1 protease near the polymerase-RNase H junction of p66 is completely inaccessible to solvent in the structure reported here. This suggests that the homodimeric p66-p66 precursor of mature RT is asymmetric with one of the two RNase H domains at least partially unfolded.
Primitive Earth Synthesis of Nicotinic Acid Derivatives
Authors: Friedmann Nadav , Miller Stanley L. , Sanchez Robert A.
Published: October 2006

Nicotinonitrile, 2-cyanopyridine, and 4-cyanopyridine can be synthesized under primitive earth conditions by the action of electric discharges on ethylene and ammonia. The electric discharge first synthesizes pyridine and hydrogen cyanide, which react in the discharge to form the cyanopyridines. Nicotinonitrile would have hydrolyzed in the primitive ocean to nicotinamide and nicotinic acid.
Major Element Variation and Possible Source Materials of Apollo 12 Crystalline Rocks
Authors: Kushiro Ikuo , Haramura Hiroshi
Published: October 2006

Nine different crystalline rocks of the Apollo 12 samples have been analyzed with conventional chemical rock analysis methods. Five of the rocks have normative quartz, whereas the others have normative olivine and hypersthene. The rocks show a wide range in the ratio of iron to magnesium, and their compositions fall on relatively smooth curves in the oxide variation diagram. It is suggested that these rocks, with one exception, represent different parts of a differentiated magmatic body, in which magmatic differentiation by crystallization and settling of olivine was most effective. The source material of the original magma may be peridotite with or without minor amounts of plagioclase or spinel or garnet, with the presence or absence of these minerals dependent on the depth of magma generation.
A Combinatorial Approach Toward DNA Recognition
Authors: Pei Dehua , Ulrich Helle D. , Schultz Peter G.
Published: October 2006

A combinatorial approach has been used to identify individual RNA molecules from a large population of sequences that bind a 16-base pair homopurine-homopyrimidine DNA sequence through triple-helix formation. Fourteen of the seventeen clones selected contained stretches of pyrimidines highly homologous to the target DNA sequence (T⋅AT and C
+
⋅GC). In addition, these RNA molecules contained hairpin loops, interior loops, and nonstandard base triplets [C
+
(or C)⋅AT, U⋅GC, G⋅GC, and A⋅AT] at various positions. Affinity cleavage experiments confirmed the ability of selected sequences to bind specifically to the target DNA. Systematic variation in both the target DNA sequence and buffer components should provide increased insight into the molecular interactions required for triple-helix-mediated recognition of natural DNA.
Cholestasis: Lamellar Structure of the Abnormal Human Serum Lipoprotein
Authors: Hamilton Robert L. , Havel Richard J. , Kane John P. , Blaurock Allen E. , Sata Teizo
Published: October 2006

An abnormal lipoprotein was visualized directly in serum by electron microscopy of preparations negatively stained with potassium phosphotungstate. It appears as a unique disk-shaped particle with major axis measuring 400 to 600 angstroms and minor axis measuring about 100 angstroms. Chemical analysis, viscosity measurements, and x-ray diffraction analysis of purified preparations indicate that the particle, consisting of a one-to-one molar mixture of cholesterol and choline phosphatides associated with a small amount of protein, is a flattened vesicle, the wall of which is a continuous lipid bilayer.
Acetylcholine Liberation from Cerebral Cortex during Paradoxical (REM) Sleep
Authors: Jasper Herbert H. , Tessier Jacques
Published: October 2006

The rate of liberation of free acetylcholine from the surface of prostigmin-treated cerebral cortex in the freely moving cat has been determined in states of slow wave sleep, paradoxical or activated sleep, and waking. The average rate during slow wave sleep (1.2 nanograms per minute per square centimeter of cortical surface) increased during paradoxical sleep (2.2 nanograms per minute) and during waking (2.1 nanograms per minute). The rate of acetylcholine release is thus related to the electroencephalogram pattern of desynchronized activation of the cortex rather than to the behavioral responsiveness of the animals.