bluuebunny/crossref_metadata_2025 huggingface dataset:
Actinomycin D Inhibition of Deoxyribonucleic Acid-Dependent Synthesis of Ribonucleic Acid
Authors: Goldberg I. H. , Rabinowitz M.
Published: October 2006

Minute amounts of actinomycin D inhibit the synthesis of ribonucleic acid by nuclear extracts of HeLa cells in a ribonucleic acid-synthesizing system that is dependent on deoxyribonucleic acid and requires the presence of all four ribonucleoside triphosphates. The inhibition can be reversed by adding deoxyribonucleic acid to the enzymatic reaction. These findings support the work of others on the mode of action of actinomycin D in vivo.
Very Small Diatoms: Preliminary Notes and Description of
Chaetoceros galvestonensis
Authors: Collier Albert , Murphy Alice
Published: October 2006

Several species and genera of very small diatoms have been isolated from Gulf of Mexico waters at Galveston. A quantitative and qualitative study of their distribution has not yet been made. The organisms were isolated in unialgal cultures, and very rapid growth rates were observed. Environmental and experimental implications are pointed out. A new species,
Chaetoceros galvestonensis,
1.5 by 3.0 microns in broad view, is described and figured.
Gravity Factor for Auxin Transport
Authors: Lyon Charles J.
Published: October 2006

The elongating internodes of the axis of a vigorous dicotyledonous plant develop strong curvatures if the tropistic effect of gravity is eliminated on a clinostat. Similar curvatures are produced by unbalancing either the supply of auxin or its transport paths, but only in the absence of unidirectional gravity as a distributive force.
Radiocarbon Ages of Postglacial Lake Clays near Michigan City, Indiana
Authors: Winkler Erhard M.
Published: October 2006

Two radiocarbon dates were obtained for postglacial clays. One sample, 6350 years old, was taken from a bed of compacted and carbonized wood just above a bed of pebbly clay. Overlying the woody bed is 5½ feet of organic bluish clays and beach sands near the present lake level. The upper clay layer contained a younger wood sample, 5475 years old. The blue clays are of shallow swamp origin and were deposited during the late low-water stage of Lake Chippewa; the pebbly clay is assumed to be of Glenwood age (about 11,000 years) or older.
Relationship of Erythrocyte to Leukocyte Antigens in Chickens
Authors: Schierman Louis W. , Nordskog Arne W.
Published: October 2006

Tests with blood typing antisera revealed that antigens of the
A
,
D
, and
L
blood group systems are erythrocyte specific, while antigens of the
B
and
C
systems are common to lymphocytes and erythrocytes. Injection of day-old chicks with erythrocytes inhibited production of agglutinins for lymphocytes as well as erythrocytes when subsequent immunizations were attempted.
Catalytic Dehydrogenation of Coal
Authors: Raymond Raphael , Wender Irving , Reggel Leslie
Published: October 2006

Coals were refluxed with palladium, ruthenium, and rhodium catalysts in high-boiling aromatic and heteroaromatic solvents. As much as 53 percent of the hydrogen in one coal was evolved as hydrogen gas. The yield of hydrogen varied with the rank of the coal and the nature of the solvent but was little influenced by the metal or catalyst support.
Electron Spin Resonance of Nitric Oxide-Hemoglobin Complexes in Solution
Authors: Sancier K. M. , Freeman G. , Mills J. S.
Published: October 2006

The electron spin resonance spectra of solutions of nitric oxide-hemoglobin and nitric oxide-methemoglobin, and whole blood treated at room temperature with nitric oxide, all exhibit resonance with a line width of 83 gauss, a g-value of 2.03, and a spin intensity corresponding to one unpaired electron spin per heme. The minimum detectable concentration of these nitric oxide complexes in solution is 10
-5
M.
Solutions were stable in a nitrogen atmosphere but when exposed to air in the absence of nitric oxide the spin intensity decreased with a half-life of about 5 hours. A preliminary examination of blood of rats exposed 1 and 9 days to 10 ppm of nitric oxide in air showed no electron spin resonance.
Variable Transmission Silicate Glasses Sensitive to Sunlight
Authors: Cohen Alvin J. , Smith Herbert L.
Published: October 2006

The process of variable transmission in silicate glasses has been accomplished by optically pumping color centers by electron transfer from europium (II) or cerium (III) which absorb sunlight at higher energies than the color center. Absorbed energy quickly pumps the visible color center band to a maximum. Upon removal of activating light, the visible color spontaneously decays.
Heart Autotransplantation: Effect on Myocardial Catecholamine and Histamine
Authors: Cooper Theodore , Willman Vallee L. , Jellinek Max , Hanlon C. Rollins
Published: October 2006

Complete excision and reimplantation of the canine heart is followed by a fall in myocardial norepinephrine to negligible levels. These decreases are attributable to the sympathetic denervation which necessarily accompanies the operative procedure. Myocardial histamine levels in survivors of this operation were not significantly different from those of normal dogs.
Uptake of Strontium-85 by Alfalfa
Authors: Lee C. C.
Published: October 2006

Experiments with alfalfa were carried out to study the possibility of changes with time in the availability of radiostrontium in soil. After the soil was treated once with Sr
85
, the first crop was harvested after 60 days of growth. Four subsequent crops, cut at successive 4-week intervals, were examined. The difference in uptake between the second and fifth crops was statistically significant, suggesting that some fixation of Sr
85
may occur in the soil. The effects of various applications of ammonium dihydrogen phosphate, monocalcium phosphate, calcium chloride, and potassium chloride on the uptake of Sr
85
by alfalfa were also investigated. Of the experiments carried out, only the treatment with 1.0 meq of potassium per 100g of soil resulted in a statistically significant reduction in strontium uptake.
Serial Propagation of Influenza B (Lee) Virus in a Transmissible Line of Canine Kidney Cells
Authors: Green Irving J.
Published: October 2006

The serial propagation of influenza B (Lee) virus has been demonstrated in a transmissible line of canine kidney cells, as evidenced by the presence of cytopathic effects and hemagglutinins in each of six consecutive tissue-culture passages, and by egg infectivity titers of 10
-4.3
and 10
-4.1
per 0.1 ml in 3rd and 5th tissue culture fluids, respectively.
Sodium Iodide Crystal Dosimeters for Use in Surveys of Regions of High Background Radiation
Authors: Roser Francisco X. , Cullen Thomas L.
Published: October 2006

In a study of selected regions of high background radiation in Brazil, thallium-activated NaI crystals were used as density amplifiers for dosimeter film badges. Calibration experiments were made, and the field results are summarized.
Evaluation of Isotope Exchange by Chromatography
Authors: Morávek J. , Nejedlý Z. , Filip J.
Published: October 2006

The study of exchange reaction kinetics between sulfur-35 and organic compounds which contain sulfur can be made much easier by use of radiochromatography. Activity ratios of the components of the reaction mixture can be estimated by use of very small amounts of radioactive materials. The reaction need not be halted and individual components need not be isolated. Any degradation of reacting substances can be measured quantitatively at the same time.
Quantitative Analysis of Blood Circulation through the Frog Heart
Authors: DeLong Karl T.
Published: October 2006

Analysis of the oxygen content of blood in the frog heart and its major vessels has shown that in
Rana pipiens
the carotids receive primarily left atrial blood, which is highly oxygenated, whereas the pulmocutaneous vessels receive blood almost exclusively from the right atrium. Only the aortas receive blood subjected to considerable mixing.
Binding of Inert Gas Halogenide Molecules
Authors: Allen Leland C.
Published: October 2006

An electronic explanation of the existence of noble gas halides and predictions of the properties to be expected of these compounds is presented.
Visual Observations of Nightglow from Manned Spacecraft
Authors: Carpenter Malcolm Scott , O'Keefe John Aloysius , Dunkelman Lawrence
Published: October 2006

The luminous band around the horizon noted by J. Glenn in the first U.S. manned orbital flight is attributable to airglow. Dip-of-the-horizon measurements on the star γ Ursae Majoris showed that the band is centered at an elevation of 91 kilometers or somewhat higher. The edge-on brightness of the airglow layer was 6 × 10
-7
candles per square centimeter.
Fusion of the Leucine Zipper Gene
HLF
to the
E2A
Gene in Human Acute B-Lineage Leukemia
Authors: Inaba Toshiya , Roberts W. Mark , Shapiro Linda H. , Jolly Kent W. , Raimondi Susana C. , Smith Stephen D. , Look A. Thomas
Published: October 2006

A t(17;19) chromosomal translocation in early B-lineage acute leukemia was shown to result in chimeric transcripts that contain sequences from the
E2A
basic helix-loop-helix transcription factor gene on chromosome 19, fused to sequences from a previously unidentified gene (
HLF
) on chromosome 17 that encodes a hepatic leukemia factor. The chimeric protein consisted of the amino-terminal transactivation domain of E2A linked to the carboxyl-terminal basic region-leucine zipper domain of HLF. HLF was normally expressed in liver and kidney, but not in lymphoid cells, and was found to be closely related to the leucine zipper-containing transcription factors DBP (albumin D-box binding protein) and TEF (thyrotroph embryonic factor), which regulate developmental stage-specific gene expression.
Hemolysis in Identifying Eaton's Pleuropneumonia-Like Organism
Authors: Clyde Wallace A.
Published: October 2006

A method for readily demonstrating hemolysis of mammalian erythrocytes by Eaton's pleuropneumonia-like organism is described. This reaction may be useful in preliminary identification of this organism, since other strains from human sources are not known to have this property.
"Caudate-Induced" Cortical Potentials: Comparison between Monkey and Cat
Authors: Goldring Sidney , Anthony Lyndon U. , Stohr Paul E. , O'Leary James L.
Published: October 2006

The segment of the internal capsule which carries axons relating to the sensorimotor cortex does not closely adjoin the caudate in the monkey as it does in the cat. Therefore, in seeking evidence for caudate-induced cortical responses, activation of the adjoining internal capsule by stimulus spread can be avoided. In the monkey, caudate stimulation never produced cortical responses, and only capsule stimulation evoked the potential complex which has been attributed to caudate stimulation in the cat.
Indophenol Blue as a Chromogenic Agent for Identification of Halogenated Aromatic Hydrocarbons
Authors: Graham Shirl O.
Published: October 2006

The metachromatic dye indophenol blue [
N
-(
p
-dimethylaminophenyl)-1,4-naphthoquinoneimine] is adaptable for qualitative and quantitative measurements of halogenated aromatic hydrocarbons in paper chromatographic procedures and spot tests.
"Flickering" in Protoplasts of
Bacillus megaterium
Authors: Miller D. M.
Published: October 2006

"Flickering," which has been observed in the erythrocytes of many animals, has now been observed in the protoplasts of
Bacillus megaterium
.
Altruism or Arousal in the Rat?
Authors: Lavery J. J. , Foley P. J.
Published: October 2006

If rats are exposed successively to white noise, then to recorded rat squeals, or alternatively to squeals first and then white noise, and if, in both situations, they are allowed to shut off the auditory stimulation by applying pressure on a bar, they will touch the bar more frequently when exposed to white noise. The results indicate that the bar-pressing behavior is the expression of increased activity resulting from the increased stimulation.
Electroencephalographic Desynchronization during Deep Sleep after Destruction of Midbrain-Limbic Pathways in the Cat
Authors: Carli Giancarlo , Armengol Vilma , Zanchetti Alberto
Published: October 2006

Lesions which interrupt the ascending limb of the midbrain-limbic circuit in the cat at different levels, or which even destroy it completely, do not prevent electroencephalographic desynchronization at the beginning of periods of deep sleep, nor do they affect the maintenance of desynchronization throughout the sleep episodes. The pontine mechanisms responsible for these electroencephalographic patterns can apparently exert their influence through ascending pathways other than those directly impinging on the hypothalamus and the limbic system.
Strychnine: Its Action on Spinal Motoneurons of Cats
Authors: Fuortes M. G. F. , Nelson P. G.
Published: October 2006

In cats strychnine does not alter measurably the potential, threshold, after potentials, or refractoriness of the membrane of the spinal motoneurons. Increased reflexes probably result from increase of excitatory impingement upon motoneurons. Spikes recorded during a rapid succession of nerve impulses produced by strychnine ("strychnine burst") suggest that soma membrane resistance is appreciable during stimulation.
Night Airglow Observations from Orbiting Spacecraft Compared with Measurements from Rockets
Authors: Koomen M. J. , Gulledge Irene S. , Packer D. M. , Tousey R.
Published: October 2006

A luminous band around the night-time horizon, observed from orbiting capsules by J. H. Glenn and M. S. Carpenter, and identified as the horizon enhancement of the night airglow, is detected regularly in rocket-borne studies of night airglow. Values of luminance and dip angle of this band derived from Carpenter's observations agree remarkably well with values obtained from rocket data. The rocket results, however, do not support Carpenter's observation that the emission which he saw was largely the atomic oxygen line at 5577 Å, but assign the principal luminosity to the green continuum.
Molecular Model for Protein Synthesis
Authors: Zubay Geoffrey
Published: October 2006

Molecular models constructed for RNA, adapter RNA, and the ribosome are consistent with available physical-chemical data. These components can be assembled to produce a stereochemically sound model for the template mechanism in protein synthesis.
Bent Chemical Bonds
Authors: Flygare W. H.
Published: October 2006

The obvious and not original conclusion is that the results obtained from considerations of
sp
3
hybridization in the substituted methanes breaks down as soon as all of the bonding atoms are not equivalent. Indeed, the concept of
sp
3
localized carbon hybrids may be invalid even for tetrahedral molecules like CCl
4
where the result of tetrahedral angles may be inferred from a naive hard sphere model. In other words the electrons in CCl
4
have a more delocalized molecular quality than the apparently more localized atomic quality in CH
4
. This result implies that perhaps a Hartree-Fock treatment of the outer valence electrons in the substituted methanes (frozen inner atomic shells) might give a fairly good description of the electron distribution. On the other hand, the valence bond method would have to be carried well past the convenient approximation of perfect pairing. McWeeny and Ohno were quite optimistic about the frozen inner atomic shell approximation in their treatment of H
2
O. As far as the strained small-ring compounds it appears the bending of a bond is a function of where one decides to draw the line between localized and delocalized character. Finally, no more appropriate ending could be contrived than a classic quote by Professor R. S. Mulliken, "I believe the chemical bond is not so simple as some people seem to think."
Synergistic Effect of 5-Bromodeoxyuridine and Gamma Rays on Chromosomes
Authors: Koo F. K. S.
Published: October 2006

The combined effect of 5-bromodeoxyuridine and gamma rays on chromosomes in cells from the root tips of
Zebrina pendula
is synergistic. The enhanced, combined effects per cell of aberrations, bridges, and acentric fragments were, respectively, 2, 2.4, and 1.9 times the sum of the separate effects.
Electron Microscope Autoradiography of Bacteria Labeled with Iodine-125
Authors: Kuhn Nobuko O. , Harford Carl G.
Published: October 2006

The low-energy extranuclear electrons emitted by iodine-125 can be used for electron microscope autoradiography with results comparable to those obtained with tritium. Autoradiographs of tritium-labeled bacteria showed that 71 percent of all reacted grains localized on the cell. This figure was 86 percent when I
125
-labeled bacteria were used.
"Microsome" Fraction of Brain: Structural Changes Induced by Ascorbic Acid
Authors: Aghajanian G. K.
Published: October 2006

The usual vesicular configuration of membrane fragments in the brain "microsome" fraction is radically altered by treatment with ascorbic acid and adenosine monophosphate. Light-scattering measurements and electron micrographs show that the treated membranes assume predominantly planar forms. This change in structure appears to be contingent upon a continued transport of electrons from ascorbic acid.
Lactate Dehydrogenase Variant from Human Blood: Evidence for Molecular Subunits
Authors: Boyer Samuel H. , Fainer David C. , Watson-Williams E. J.
Published: October 2006

A variant of human lactate dehydrogenase is described. The occurrence of lactate dehydrogenase-1, -2, -3, and -4 as five, four, three, and two components, respectively, is interpreted as supporting the hypothesis that LDH isozymes are tetramers formed from various combinations of two types of subunits.
Caudate Nucleus Lesions: Behavioral Effects in the Rat
Authors: Chorover Stephan L. , Gross Charles G.
Published: October 2006

Bilateral lesions within the caudate nucleus led to a marked impairment on acquisition and retention of a spatial alternation habit but produced no deficit in Hebb-Williams maze performance. Conversely, subtotal bilateral lesions of posterior cortex produced no significant deficit on the alternation habit but markedly impaired maze performance.
Photochemical Production of the Solvated Electron in Ethanol
Authors: Grossweiner Leonard I. , Zwicker Earl F. , Swenson George W.
Published: October 2006

Flash photolysis of several inorganic anions in ethanol gives an absorption spectrum attributed to the solvated electron.
Photosensitizing Substance in Human Serum: Effect on HeLa Cells
Authors: Wheeler Willis B. , Hollinshead Ariel C.
Published: October 2006

The destructive effects of blue and white light on HeLa cells grown in monolayers is described. Apparently, there is a photosensitizer in the human-serum component of the growth medium. The photosensitizer may be a compound containing riboflavin.
A Priori Evaluation of Aqueous Polarization Effects through Monte Carlo QM-MM Simulations
Authors: Gao Jiali , Xia Xinfu
Published: October 2006

A Monte Carlo quantum mechanical-molecular mechanical (QM-MM) simulation method was used to determine the contributions of the solvent polarization effect to the total interaction energies between solute and solvent for amino acid side chains and nucleotide bases in aqueous solution. In the present AM1-TIP3P approach, the solute molecule is characterized by valence electrons and nucleus cores with Hartree-Fock theory incorporating explicit solvent effects into the total Hamiltonian, while the solvent is approximated by the three-point charge TIP3P model. The polarization energy contributes 10 to 20 percent of the total electrostatic energy in these systems. The performance of the hybrid AM1-TIP3P model was further validated by consideration of bimolecular complexes with water and by computation of the free energies of solvation of organic molecules using statistical perturbation theory. Excellent agreement with ab initio 6-31G(d) results and experimental solvation free energies was obtained.
Spectrophotometric Titrations of Human Serum Albumin and Reduced Carboxymethylated Albumin
Authors: Eisenberg David S. , Edsall John T.
Published: October 2006

The tyrosyl groups of reduced and carboxymethylated human serum albumin, in which all disulfide bonds are broken, ionize at lower
p
H than those of native albumin, in spite of the greater negative charge on the protein produced by the S-carboxymethyl groups. The heat and entropy of ionization of these groups in the reduced albumin are also "normal," in contrast to native albumin. Spectrophotometric titrations at 244 and 295 mμ give equivalent results. The more open structure of the reduced albumin, as compared with the native protein, presumably allows the tyrosine groups to come freely into contact with solvent. In acid solutions the heights of the two peaks at 236 and 287 mμ in the difference spectrum (albumin at
p
H 7 against albumin at a lower
p
H) are strictly proportional over the whole course of the titration. Both peaks apparently arise from changes in the environment of tyrosyl residues, rather than from more general conformational changes.
Spectroscopic Ultramicroanalysis with a Laser
Authors: Rosan Robert C. , Healy Mary K. , McNary William F.
Published: October 2006

A microbeam probe capable of vaporizing many biological materials is formed by focusing a conventional laser through a microscope objective. The elemental gases which are excited by this demagnified spot are raised to emission levels when sparked between carbon electrodes. Elemental analysis is then performed on the excited material by conventional spectroscopy. The method is simple and rapid. Simultaneous analysis of multiple elements is practical.
Schistosome Ova: Rapid Separation from Mouse Tissue by Digestion with Pinguinain
Authors: Toro-Goyco E. , Rivera-Collazo E. , Rodriguez-Molina R.
Published: October 2006

High yields of ova of
Schistosoma mansoni
were obtained from the livers and intestines of infected mice by digestion of the homogenized tissue with the proteolytic enzyme pinguinain.
Insecticide Resistance: Effects of WARF Antiresistant on Toxicity of DDT to Adult Houseflies
Authors: Spiller D.
Published: October 2006

Addition of
N,N
-dibutyl-
p
-chlorobenzene sulphonamide (Antiresistant/DDT) in amounts equal to one fifth the dose of DDT increased the toxicity of DDT to the DDT-resistant portion of a housefly population. Full susceptibility was not regained. There was no increase in toxicity to the DDT-susceptible portion.
Starch Synthesis in Excised Lemon Fruit Tissue Growing in vitro
Authors: Kordan Herbert A.
Published: October 2006

Significant quantities of starch accumulation were evident in excised mature lemon fruit tissue growing in vitro on a nutrient solution of mineral salts and sucrose. Positive evidence for the presence of starch in the growing cells was obtained with iodine staining and polarizing microscopy. Starch was observed in all growing cultures regardless of age.
Color Polymorphism in Pacific Tree Frogs
Authors: Resnick Linda E. , Jameson David L.
Published: October 2006

Crosses between green and non-green
Hyla regilla
suggest that green color is determined by genes at two loci; each loci must have a dominant gene. Red is the result of a recessive gene and brown a dominant gene. The frequency of frogs with each color varies in different populations.
Inhibition of Evoked Potentials by Striatal Stimulation and Its Blockage by Strychnine
Authors: Krauthamer George M.
Published: October 2006

Brief stimulation of the basal ganglia in cats deeply anesthetized with chloralose produces a selective, prolonged inhibition of multisensory peripherally evoked potentials at different levels of the neuraxis without altering activity in primary sensory pathways. The inhibition is blocked by small amounts of strychnine, administered intravenously.
Forms of Sounds as Shown on an Oscilloscope by Roulette Figures
Authors: Barton George W. , Barton Stephen H.
Published: October 2006

It has been found that with an oscilloscope driven through a simple network of two resistors and two capacitors it is possible to produce recognizable pictures from speech sounds. These pictures thus become a natural phonetic alphabet, with which both standard pronunciation and the nuances of dialect and accent can be represented. While a given speech sound has certain invariant characteristics, it has also an overlay of accent, which can be represented in the alphabetic character. It is suggested that the technique may be useful in teaching deaf children to speak.
Milk Analysis of the Kangaroo Rat,
Dipodomys merriami
Authors: Kooyman Gerald L.
Published: October 2006

The milk of
Dipodomys merriami
has an average water content of 50.42 percent, which is low compared with milk from other mammals. The fat content is about 23.48 percent. The significance of these values is discussed in terms of the animal's water balance.
Selenoamino Acids: Decrease of Radiation Damage to Amino Acids and Proteins
Authors: Shimazu F. , Tappel A. L.
Published: October 2006

Selenomethionine and selenocystine protect amino acid and protein systems from radiation damage. Selenoamino acids are more powerful protectors than the analogous sulfur amino acids and other known —SH protectors. Free-radical scavenger and repair mechanisms by which selenoamino acids react with induced free radicals may be the key reactions in the biological function of selenium.
Identity of Tarichatoxin and Tetrodotoxin
Authors: Buchwald H. Dieter , Durham Lois , Fischer Hans G. , Harada Rockuro , Mosher Harry S. , Kao C. Y. , Fuhrman Frederick A.
Published: October 2006

Tarichatoxin (C
11
H
17
N
3
O
8
), a potent neurotoxin recently isolated in pure form from the eggs of the California newt,
Taricha torosa
, has been found to be identical to tetrodotoxin from the ovaries of
Sphoeroides rubripes
, the Japanese Fugu or puffer fish. As yet this substance has been detected only in a single family of fish,
Tetraodontidae
, and in a single family of amphibia,
Salamandridae
.
Analysis of Variance of Migmatite Composition II: Comparison of Two Areas
Authors: Ward Richard F. , Werner Sharon L.
Published: October 2006

To obtain comparison with previous results an analysis of variance was made on measurements of proportion of granite and country rock in a second Colorado migmatite. The distributional parameters (mean and variance) of both regions are similar, but the distributions of variance among the three levels of the nested design differ radically.
Daily Fluctuation in the Blood Sugar Concentration of the House Cricket,
Gryllus domesticus
L.
Authors: Nowosielski Józef W. , Patton Robert L.
Published: October 2006

The disaccharide trehalose is the main carbohydrate constituent in the hemolymph of the house cricket,
Gryllus domesticus
L. At different times of day the blood sugar in the hemolymph of crickets showed a fluctuation in trehalose concentration, which reached a peak value about 3 hours before dawn.
Intestinal Phosphatase Activity: Acceleration of Increase by Puromycin and Actinomycin
Authors: Moog Florence
Published: October 2006

Alkaline phosphatase activity of the mouse duodenum normally increases 20-fold between 13 and 20 days. Activity at 15 days is raised two to three times above normal by administering actinomycin D, puromycin, or the aminonucleoside of puromycin at 13 or 14 days. Phosphatase activity in the jejunum and kidney are not similarly affected.
Color Discrimination in the Cat
Authors: Sechzer Jeri A. , Brown John Lott
Published: October 2006

Red-green color discrimination by cats was demonstrated in a situation which effectively eliminated cues based on relative brightness. The persistence of the cat's response to cues based on brightness differences may help to account for the failure of previous experiments to show that cats can make behavioral color discriminations.
Calcium Absorption in Man: Based on Large Volume Liquid Scintillation Counter Studies
Authors: Lutwak Leo , Shapiro Jay R.
Published: October 2006

A technique has been developed for the in vivo measurement of absorption of calcium in man after oral administration of 1 to 5 microcuries of calcium-47 and continuous counting of the radiation in the subject's arm with a large volume liquid scintillation counter. The maximum value for the arm counting technique is proportional to the absorption of tracer as measured by direct stool analysis. The rate of uptake by the arm is lower in subjects with either the malabsorption syndrome or hypoparathyroidism. The administration of vitamin D increases both the absorption rate and the maximum amount of calcium absorbed.
Coal Mine Disasters: Frequency by Month
Authors: Boyer Raymond F.
Published: October 2006

Major coal mine disasters (five or more fatalities per accident) in the United States over the past 150 years have tended to occur primarily in the winter months from November through April. Minor accidents (zero to four fatalities per accident) occur at a fairly uniform rate throughout the year. This peak for major disasters is ascribed to effect of barometric minima on the methane content of mine air, to the effect of dry polar air masses in reducing the moisture content of coal dust, and, possibly, to cyclic fatigue of rock structures from cycling barometric pressure. Obvious safety practices are suggested.
Adenosine Triphosphate: Changes in Muscles Doing Negative Work
Authors: Infante Anthony A. , Klaupiks Dzintra , Davies Robert E.
Published: October 2006

Frog sartorius muscles were isolated, treated with 1-fluoro-2,4-dinitrobenzene at 0°C, then stimulated tetanically at the length in situ and stretched with a Levin-Wyman ergometer during stimulation. The normal adenosine triphosphate breakdown during the tetanus was reduced by about half during the forced stretch. The tension was increased by about 70 percent, but resynthesis of adenosine triphosphate did not occur. Thus, on the basis of A. V. Hill's results, adenosine triphosphate is probably not the direct final energy source for muscular contraction, although it intimately participates in the process. The use of adenosine triphosphate during negative work was less than one-tenth that needed for positive work.
Amphibian Cell Culture: Permanent Cell Line from the Bullfrog (
Rana catesbeiana
)
Authors: Wolf Ken , Quimby M. C.
Published: October 2006

A line of fibroblast cells has been established from tongue tissue of the bullfrog (
Rana catesbeiana
). The cells are near-triploid and were subcultured 57 times during the 2⅔ years of their existence. Some of their characteristics are described.
l
-Octopamine in Citrus: Isolation and Identification
Authors: Stewart Ivan , Wheaton T. A.
Published: October 2006

l
-Octopamine, [
l
-
p
-hydroxy-α-(aminomethyl)benzyl alcohol], has been isolated and identified from extracts of juice and leaves of the Meyer lemon. Identification was by chromatography, optical rotation, ultraviolet absorption curves, fluorescence spectra, and infrared spectroscopy.
l
-Octopamine has not previously been isolated and identified from plants.
Ultraviolet Sensitivity of
Escherichia coli
Containing Heat-Inducible λ Prophages
Authors: Lieb Margaret
Published: October 2006

The
c1-t
mutants of bacteriophage λ can form prophage at 36°C but cause lysis of sensitive bacteria at temperatures above 42°C. Growth of cultures at 42° to 46°C induces prophage replication and lysis in Escherichia coli K12 (λ
c1-t
); lysogenic strains containing wild-type prophage are not induced to lyse at these temperatures. Heat induction is prevented by chloramphenicol. Strains containing heatinducible prophage are much more sensitive to killing by ultraviolet light than is K12 (λ+).
Circadian Rhythmicity in the Sensitivity of Two Strains of Mice to Whole-Body Radiation
Authors: Pizzarello Donald J. , Isaak Daniel , Chua Kian Eng , Rhyne A. Leonard
Published: October 2006

When male mice of the Swiss-Webster and C
3
H strains are maintained on a light-dark cycle in which the light begins at 7 a.m. and ends at 7 p.m., they are more sensitive to whole body x-irradiation (800 to 900 roentgens) given at 2 a.m. than at any other time in the cycle tested.
Primate Retinal Responses: Slow Changes during Repetitive Stimulation with Light
Authors: Gouras P. , Carr R. E.
Published: October 2006

Sudden, repetitive illumination of the dark-adapted monkey eye produces transient changes in the electroretinogram and transocular potential which can last an hour or longer.
Magnesium Compounds: New Dense Phases
Authors: Cannon P. , Conlin E. T.
Published: October 2006

Magnesium silicide (Mg
2
Si) undergoes a transformation from a cubic (fluorite) type lattice to a hexagonal lattice at pressures above about 25 kilobars and temperatures above 900°C. There is an increase of density of about 15 percent associated with this structure change. Both the parent and product substances are semiconductors, but of different resistivities. The high pressure phase may be recovered and is indefinitely metastable at normal ambient conditions.
X-ray Diffraction Data on Two High-Pressure Phases of Calcium Carbonate
Authors: Davis B. L.
Published: October 2006

X-ray diffraction studies conducted at high pressure with a beryllium pressure vessel show that compression parallel to the
c
-axis of CaCO
3
-I (calcite), as the phase boundary of CaCO
3
-II (modified calcite type) is approached, results in a relative reduction of the
c
-axis of phase II of several times that of the
a
-axes. Such data are not consistent with previously proposed anion disorder in CaCO
3
-II. At 18.7 ± .5 kb and room temperature a new phase of CaCO
3
has been observed that is assumed to be phase III found by Bridgman. At this pressure the x-ray diffraction pattern can be indexed as orthorhombic KNO
3
-IV type, with
a
0
= 8.90 ± .01 Å,
b
0
= 8.42 ± .01 Å, and
c
0
= 7.14 ± .01 Å (
Z
= 10).
Photoflashes: A Potential New Tool for Control of Insect Populations
Authors: Barker Roy J. , Cohen Charles F. , Mayer Ann
Published: October 2006

Imported cabbageworms,
Pieris rapae
(L.), were reared in cans exposed to light from fluorescent lamps for 10 hours daily. When larvae were exposed to daily electronic photoflashes scheduled 3 to 4 hours after the fluorescent lamp was turned off, pupae failed to diapause. Effective wavelengths are lower than those controlling photoperiodism in plants. The effective energies are about 1 joule per square centimeter.
Disc Electrophoresis of
Hymenoptera
Venoms and Body Proteins
Authors: O'Connor Rod , Rosenbrook Wm. , Erickson Robert
Published: October 2006

The venom proteins of honey bee,
Polistes
wasp, yellow hornet, and yellow jacket are similar but not identical. Extracts of venom sacs and whole insects contain several proteins not found in the pure venoms.
Bee Venom Tolerance in White Mice in Relation to Diet
Authors: Benton Allen W. , Morse Roger A. , Gunnison Albert F.
Published: October 2006

In white mice the consumption of a high protein diet either just before, or over a period of 3 days prior to, the injection of venom from the honey bee
Apis mellifera
L. markedly increases the number of deaths. Conversely, a period of starvation or a nonprotein diet fed to white mice for 3 days prior to the injection of bee venom significantly reduces the number of deaths.
Visual Evoked Potentials as a Function of Flash Luminance and Duration
Authors: Wicke J. D. , Donchin E. , Lindsley D. B.
Published: October 2006

Computer-averaged evoked potentials were recorded to visual stimuli of constant duration and varying luminance, as well as to flashes whose luminance and duration varied reciprocally. With constant duration, the latency, amplitude, and waveform of the evoked response varied as a function of luminance. The effects of decreasing the luminance on amplitude and waveform of the responses can be balanced by increasing the duration of the flash. This reciprocity between luminance and duration suggests a relationship between apparent brightness and evoked potentials.
Eel Electroplaques: Spike Electrogenesis without Potassium Activation
Authors: Nakamura Yutaka , Nakajima Shigehiro , Grundfest Harry
Published: October 2006

Measurements with the voltage clamp technique demonstrate that only an early conductance increase occurs during spike electrogenesis of eel electroplaques. The delayed increase which is characteristic of spike electrogenesis in many other cells is absent. Instead, the membrane resistance increases two- to threefold above its resting value. The brief initial increase in conductance is due to sodium activation followed by rapid sodium inactivation. The influx of sodium causes an inward current of up to 80 ma/cm
2
. The inward current is abolished by eliminating the sodium from the normal medium (substitution of choline chloride for NaCl); by blocking sodium activation with tetrodotoxin; or by causing sodium inactivation through enrichment of the potassium in the medium. The delayed increase in membrane resistance is not affected by eliminating sodium influx, nor by substituting various impermeable anions for the chlorine of the normal medium. Thus, the increase in resistance signifies the occurrence of potassium inactivation which is unmasked by the absence of potassium activation.
Physical Interaction of a Murine Leukemia Virus with Influenza Virus in vitro
Authors: O'Connor T. E. , Rauscher F. J.
Published: October 2006

Incubated mixtures of PR8 influenza virus and Rauscher leukemia virus retained the egg infectivity and hemagglutinin of the influenza virus and the ability of the Rauscher virus to induce splenomegaly in mice. Density-gradient centrifugation on potassium citrate gradients revealed a new interviral product with an intermediate density as the principal constituent of such mixtures. Chicken erythrocytes adsorbed the Rauscher virus components as well as the influenza virus components of the interviral product from such mixtures at 4°C, whereas the Rauscher virus alone was little adsorbed. The adsorbed interviral product was eluted from the erythrocyte complex after incubation at 37°C.
Actinomycin and Puromycin: Effects on Sequential Gene Activation by Ecdysone
Authors: Clever Ulrich
Published: October 2006

A temporary inhibition of RNA synthesis leads to a corresponding delay in the formation of all puffs which are stimulated by ecdysone in the salivary gland chromosomes of
Chironomus tentans
. Inhibition of protein synthesis does not influence the induction of those puffs which appear shortly after injection of ecdysone. Puffs which develop after a longer period are delayed in appearance. It is concluded that early reacting genes are involved in those processes leading to the sequential activation of the puffs which appear later.
Separation of the Salivary and Motor Responses in Instrumental Conditioning
Authors: Ellison Gaylord D. , Konorski J.
Published: October 2006

If an instrumental conditioning schedule is arranged so that a dog must repeatedly perform a movement in response to one stimulus in order to secure the presentation of another stimulus, which is then followed by food, a virtually total separation of motor and salivary responses is observed. The first stimulus elicits the trained movement without salivation, and the second stimulus elicits salivation without instrumental responding. These experiments show a relative independence between classical and instrumental conditioned responses and clarify the rather complex relations between the two in the usual experimental procedure.
Paradoxical Phase of Sleep: Its Artificial Induction in the Cat by Sodium Butyrate
Authors: Matsuzaki M. , Takagi H. , Tokizane T.
Published: October 2006

In intact cats and cats with the mesencephalon transected the intravenous administration of sodium butyrate and related compounds (0.3 to 3 millimoles per kilogram) induced the so-called paradoxical phase of the sleep, as indicated by electroencephalograms, electromyograms, heart rate, respiration, and eye movement. This phase appeared after a 3- to 5-minute period of sleep characterized by slow waves, and continued for 4 to 15 minutes.
Quantized Magnetic Flux in Superconductors
Authors: Parks R. D.
Published: October 2006

The observation that the magnetic flux in a hollow superconducting cylinder is quantized in units of
hc/2e
has confirmed Fritz London's prediction that superconductivity is a macroscopic quantum phenomenon and that the superconducting state is a single-valued quantum state. It has also conclusively demonstrated that the pair interaction of the Bardeen-Cooper- Schrieffer theory of superconductivity is the important one, at least for the few superconductors studied. A superconducting ring or hollow cylinder must "decide" at the transition temperature what final quantum state it will be in when the temperature is lowered. This "thinking process" has been observed in experiments which demonstrate that the free energy of a hollow superconducting cylinder at the transition temperature is periodic in the magnetic flux. Very recently quantum-mechanical interference effects have been observed in the Josephson tunneling characteristics of multiply linked superconducting circuits. These experiments complement the other experiments on quantized flux and provide perhaps the most elegant proof of long-range order in the superconducting state.
Nucleosome Core Displacement in Vitro via a Metastable Transcription Factor-Nucleosome Complex
Authors: Workman Jerry L. , Kingston Robert E.
Published: October 2006

In order to function, transcription factors must compete for DNA binding with structural components of chromatin, including nucleosomes. Mechanisms that could be used in this competition have been characterized with the use of the DNA binding domain of the yeast GAL4 protein. The binding of GAL4 to a nucleosome core resulted in a ternary complex containing GAL4, the core histone proteins, and DNA. This ternary complex was unstable; upon the addition of nonspecific competitor DNA, it dissociated into either the original nucleosome core particle or GAL4 bound to naked DNA. Nucleosome core destabilization by GAL4 did not require a transcriptional activation domain. These data demonstrate the displacement of nucleosome cores as a direct result of binding by a regulatory factor. Similar mechanisms might affect the establishment of factor occupancy of promoters and enhancers in vivo.
Reversibility of Reaction of Potassium with Liquid Ammonia
Authors: Kirschke Ernest J. , Jolly William L.
Published: October 2006

Ammoniated electrons exist in solutions of potassium amide in liquid ammonia which have reached thermodynamic equilibrium with hydrogen gas. By determining electron concentrations by electron spin resonance, an equilibrium constant of 10
5
at room temperature has been obtained.
Genetic Influence on Experimental Allergic Thyroiditis in Guinea Pigs
Authors: McMaster Philip R. B. , Lerner Edwin M. , Mueller Peter S.
Published: October 2006

After immunization with low doses of guinea pig thyroid extract, incidence of experimental allergic thyroiditis is greater in the Hartley strain of guinea pig than in strain 13.
Localization of Calcium-Accumulating Structures in Striated Muscle Fibers
Authors: Costantin LeRoy L. , Franzini-Armstrong Clara , Podolsky Richard J.
Published: October 2006

When frog muscle fibers from which the sarcolemma had been dissected away were perfused with a calcium solution and then treated with oxalate, electron-opaque material, probably calcium oxalate, accumulated in the terminal sacs of the sarcoplasmic reticulum. These regions of calcium accumulation were identified with the intracellular calcium sink that controls the relaxation phase of the contraction-relaxation cycle; their proximity to tubules implicated in intracellular stimulus conduction suggests that they might also be regions from which calcium is released to trigger contraction.
Thymus: Role in Resistance to Polyoma Virus Oncogenesis
Authors: Law Lloyd W.
Published: October 2006

Mice of the C57BL strain are highly resistant to the oncogenic property of LID-1 polyoma virus, but complete thymectomy within 24 hours of birth rendered these mice susceptible. In thymectomized mice inoculated with adult syngeneic spleen cells, the capacity to resist oncogenesis was restored. The results add further weight to the concept that induction and progression of tumors by polyoma virus has an immunologic basis.
Polysomes from Yeast: Distribution of Messenger RNA and Capacity to Support Protein Synthesis in vitro
Authors: Marcus Leon , Bretthauer Roger , Halvorson Harlyn , Bock Robert
Published: October 2006

Individual fractions of polysomes were isolated from yeast. Pulse labeling experiments in vivo show constant specific activity of messenger RNA in each polysome peak; this suggests a uniform density of ribosomes per unit length of messenger RNA. In the cell-free incorporating system, the amount of peptide per ribosome unit increased with the size of polysome.
Pronuclear Ovum from a Patient Using an Intrauterine Contraceptive Device
Authors: Noyes R. W. , Dickmann Z. , Clewe T. H. , Bonney W. A.
Published: October 2006

Ova were sought in the washings of the excised reproductive tracts of 48 patients after they had ovulated. From 24 patients using no contraceptives, two unfertilized ova were recovered. From 24 patients using intrauterine coils, one unfertilized and one fertilized pronuclear ovum were recovered. The latter ovum was at the earliest stage of development recorded for the human.
Itch and Vibration
Authors: Melzack R. , Schecter Bayla
Published: October 2006

Itch produced by application of cowage to the wrist was reduced in intensity by vibration of the stimulated area. Application of vibration to the opposite wrist also reduced intensity. The results may be attributed to physiological activities occurring at the early stages of information transmission.
Dislocation Networks in Folded-Chain Polyethylene Crystals
Authors: Holland V. F. , Lindenmeyer P. H.
Published: October 2006

Interaction between the fold surfaces of polymer crystals can be strong enough to concentrate any mismatch in orientation into a network of dislocations. Direct observation of these networks by diffraction contrast electron microscopy yields strong evidence in favor of polymer crystallization by a regular chain-folding mechanism.
Superconducting Gallium Antimonide
Authors: McWhan D. B. , Hull G. W. , McDonald T. R. R. , Gregory E.
Published: October 2006

A metallic phase of gallium antimonide, obtained by quenching at approximately 120 kilobars to 77°K and then releasing pressure, is a superconductor. The transition temperature depends on the annealing conditions; for samples annealed at 250°C under pressure before quenching, it is 4.24° ± 0.10°K, and H
c2
(the critical field) equals 2640 gauss at 3.50°K. This temperature is higher than the 2.1°K reported for metallic indium antimonide.
Hepatic Glycogen Depletion in
Amphiuma
during Induced Anoxia
Authors: Rose Francis L. , Zambernard Joseph , Pogany Gilbert S.
Published: October 2006

Giant salamanders,
Amphiuma means
, measuring 240 to 280 millimeters from snout to vent, tolerate induced anoxia for 6 hours. After 3 hours of anoxia, hepatic glycogen units are reduced in size and concentration; after 6 hours the glycogen units are almost completely depleted. Greater development and changes in the density of the endoplasmic reticulum indicate that this structure participates in the mobilization of glycogen from the cell.
Noradrenaline Stores in Nerve Terminals of the Spleen: Changes during Hemorrhagic Shock
Authors: Dahlström Annica B. , Zetterström Bengt E. M.
Published: October 2006

In dogs subjected to hemorrhagic shock, a marked decrease in the noradrenaline content of the sympathetic nerve terminals in the normally innervated spleen is revealed by means of a histochemical fluorescence method. Deprivation of the sympathetic impulse-flow to the tissue immediately before the animals are subjected to shock prevents this depletion. The results support the hypothesis that the vasoconstriction which occurs during shock is due to the effect of noradrenaline released locally in the tissues, and not to circulating noradrenaline.