bluuebunny/crossref_metadata_2025 huggingface dataset:
Prehistoric Maize in Southeastern Virginia
Authors: Whitehead Donald R.
Published: October 2006

Five fossil maize-pollen grains were identified in a peat profile from Dismal Swamp. Extrapolation from the radiocarbon age of peat lower in the section suggests an age of 2200 years. The find suggests that a small clearing within the swamp was cultivated and thus supports the hypothesis that agriculture had diffused into coastal regions before the end of Early Woodland time.
Andromeda Galaxy: Extension of the 610.5-Megacyle-per-Second Map
Authors: Dickel J. R. , MacLeod J. M. , Swenson G. W.
Published: October 2006

A radio map of the Andromeda galaxy, M 31, made with the 400-foot (122 m) radio telescope at the University of Illinois has been extended northward to cover the full optical extent of the galaxy. Several condensations of radio emission appear along the major axis of the galaxy, and other radio features are resolved.
Electrophysiological Studies of Chilean Squid Axons under Internal Perfusion with Sodium-Rich Media
Authors: Tasaki Ichiji , Luxoro Mario , Ruarte Adolfo
Published: October 2006

Electrophysiological properties of giant axons of Chilean squid were examined by intracellular perfusion combined with various recording techniques. The amplitude of the action potential of the axons perfused with equal sodium concentrations (0.35
M
) on both sides of the membrane was approximately 75 millivolts (glutamate salts being used internally); the resting potential recorded with a calomel electrode was roughly 45 mv. These observations confirm and extend previous data, obtained from Chilean squid axons, which show that the amplitude of the action-potential overshoot does not agree with the Nernst equation applied to sodium ion. The discrepancy between these results and those obtained by others is attributed to differences in the procedures used to determine the resting potential.
Effect of Gamma Radiation on Dietary and Hormonal Induction of Enzymes in Rat Liver
Authors: Pitot Henry C. , Peraino Carl , Lamar Carlos , Lesher Sam
Published: October 2006

The dietary induction of serine dehydrase, produced by the oral intubation of hydrolyzed casein to protein-depleted rats, is markedly inhibited by doses of γ-radiation of 400 roentgens or higher provided the irradiation is given within an hour after the initial dose of casein. If the irradiation is delayed until 7 hours after the initial dose of casein, induction is not inhibited. In contrast, the cortisone induction of tyrosine α-ketoglutarate transaminase is not inhibited by doses of γ-radiation up to 3200 roentgens; in some instances hormonal induction of this enzyme appears to be enhanced by irradiation.
Antibody-Complement Complexes
Authors: Willoughby William F. , Mayer Manfred M.
Published: October 2006

Soluble complexes containing the second and fourth components of guinea pig complement, as well as hemolytic rabbit antibody, have been prepared by elution from sheep erythrocytes carrying these factors. These complexes render erythrocytes susceptible to lysis by the other factors of guinea pig complement, without the usual requirements for hemolytic antibody, Ca
++
, and Mg
++
.
Prolonged Excitation in the Visual Cortex of the Cat
Authors: Evans C. R. , Robertson A. D. J.
Published: October 2006

Intense light flashes produce maintained increased in cortical activity not dependent on continuous excitation from the retina.
Radiation Sintering of Lunar Dust
Authors: Smoluchowski R.
Published: October 2006

Protons in the solar wind displace atoms in the grains of lunar dust. These atoms may, through diffusion, sinter the dust layer into a partly coherent but still highly porous structure.
Blood-Flow Relation between Hepatic Artery and Portal Vein
Authors: Ternberg Jessie L. , Butcher Harvey R.
Published: October 2006

Blood flows in the hepatic artery and portal vein have been measured with a square-wave, electromagnetic flow meter. Hepatic arterial flow increased when portal venous flow was decreased, but, when hepatic arterial flow was decreased, portal venous flow also decreased. The relation between the two blood systems can be explained as the simple mechanical effect of interposing a slower-flowing stream in the path of a faster-flowing stream.
Phenylketonuria: Limit in Capacity of Pre-Weanling Rats To Oxidize β-Phenyllactate and Other α-Hydroxy Acids
Authors: Goldstein Fred B.
Published: October 2006

In comparison with mature animals, pre-weanling rats have markedly higher and longer lasting serum levels of β-phenyllactate following the intraperitoneal injection of a moderate dose. A corresponding age-dependent difference in the rate of oxidation of β-phenyllactate and other α-hydroxy acids was observed in experiments with homogenates and supernatant fractions of rat kidney.
Codominance of Visual Pigments in Hybrid Fishes
Authors: McFarland William N. , Munz Frederick W.
Published: October 2006

Visual pigments of lake char and brook char (Salmonidae) are based on two different proteins. Both proteins are present in first-generation hybrids between these species and they segregate in second-generation and backcross hybrids, as expected of a single-factor difference. This first genetic study suggests that shifts observed in the absorption spectra maxima of visual pigments are related to substitutions of amino acids in the visual proteins.
Volume Measurements on Chromium to Pressure of 30 Kilobars
Authors: Evenson William E. , Hall H. Tracy
Published: October 2006

The unit cell volume of chromium was measured as a function of pressure from 1 bar to 30 kilobars by x-ray diffraction techniques. The antiferromagnetic transition occurred at 1.5 kilobars at 29°C, where there is a discontinuity in the slope of the curve for lattice parameter vs. pressure. By electrical resistance measurements the value of -Δ
T
N
/Δ
P
was determined to be 5.9° ± 0.3° per kilobar. At room temperature chromium remains in the body-centered cubic crystal structure from 0 to 55 kilobars.
Sulfur: Incorporation into the Transfer Fraction of Soluble Ribonucleic Acid
Authors: Schleich Thomas , Goldstein Jack
Published: October 2006

When S
35
-labeled soluble RNA from
Escherichia coli
K 38 is subjected to gel filtration, four fractions of RNA are obtained by elution. Only one RNA fraction, the transfer RNA, contains sulfur, presumably as thionucleotides. Treatment with ribonuclease suggests that the incorporated sulfur is an integral part of the polynucleotide chain; digestion with alkali yields a mixture of products containing sulfur, the major one being eluted in a position similar to uridine diphosphate upon Dowex-1 chromatography. Analysis by countercurrent distribution of S
35
-labeled transfer RNA from
E. coli
B reveals that the incorporated sulfur is found in many RNA's that accept amino acids, but the possibility remains that not all acceptor RNA's contain sulfur.
Quenching of DNA Phosphorescence
Authors: Isenberg I. , Baird S. L. , Rosenbluth R.
Published: October 2006

Paramagnetic cations quench the phosphorescence of DNA at concentrations well below one ion per DNA phosphate. The order of quenching efficiency is copper, nickel, cobalt, and manganese.
Iodine: Accumulation by
Balanoglossus gigas
Authors: De Jorge F. B. , Sawaya Paulo , Petersen J. A. , Ditadi A. S. F.
Published: October 2006

The whole body of the giant Brazilian enteropneust,
Balanoglossus gigas
, shows an accumulation of iodine, but the concentration in the hepatic region is 854.7 percent higher than it is in the proboscis, where the amount of iodine is the lowest. Such an iodine concentration has not yet been detected in any other enteropneust or protochordate.
Genetic Factors and Polypeptide Chain Subclasses of Human Immunoglobulin G Detected in Chimpanzee Serums
Authors: Alepa F. Paul , Terry William D.
Published: October 2006

The Gm and Inv genetic factors, characteristic antigens of human immunoglobulin G, were detected in chimpanzee serums. All animals tested were Gm(a+, x—, b
1
—, b
2
—, b
3
+, b
4
+). Polymorphism was demonstrated for factors Gm(c), Inv(l), and Inv(b). Three of the subclasses of heavy polypeptide chains and both types of light polypeptide chains that are present in human immunoglobulin G were identified in chimpanzee serums.
Defective RNA Synthesis in Lymphocytes from Patients with Primary Agammaglobulinemia
Authors: Cline M. J. , Fudenberg H. Hugh
Published: October 2006

Addition of tetanus toxoid to sensitized lymphocytes from normal subjects and patients with "secondary" acquired agammaglobulinemia resulted in an increased incorporation of tritiated uridine into RNA and this increase was sustained for 48 to 72 hours in vitro. In contrast, the quantity of H
3
-uridine incorporated into the RNA of lymphocytes from patients with "primary" acquired agammaglobulinemia decreased after 48 hours of exposure to specific antigen. Lymphocytes from patients with primary agammaglobulinemia were also distinguished by their subnormal and poorly sustained response to phytohemagglutinin and to rabbit antiserum to lymphocytes. These data suggest that the defect in primary agammaglobulinemia involves, either as a primary phenomenon or as a secondary event, an abnormality of quantitative RNA synthesis or of RNA stability in the circulating lymphocyte.
Pogonophora: Living Species Found off the Coast of Florida
Authors: Nielsen Claus
Published: October 2006

A population of pogonophorans, consisting of species attributable to at least four genera and living at a depth of about 200 meters in an accessible locality off south Florida, has been discovered.
Electron Microscopic and Biochemical Characterization of Fraction I Protein
Authors: Haselkorn R. , Fernández-Morán H. , Kieras F. J. , van Bruggen E. F. J.
Published: October 2006

Electron micrographs of high resolution have been obtained from fraction I protein of Chinese cabbage leaves. The protein, which has ribulose-1,5-diphosphate carboxylase activity, appears to be a cube with edge of about 120 angstroms. Substructure can be seen in individual particles, consistent with a model having 24 subunits, the number prescribed by the available physical and chemical data.
Acheulian Occupation Sites at Torralba and Ambrona, Spain: Their Geology
Authors: Butzer Karl W.
Published: October 2006

The Acheulian occupation sites of Torralba and Ambrona, central Spain, lie within the Torralba Formation, a complex of alluvial and slope deposits dating from a long period of glacial climate before the Holstein (Mindel-Riss) interglacial.
Artifact from Deposits of Mid-Wisconsin Age in Illinois
Authors: Munson Patrick J. , Frye John C.
Published: October 2006

Discovery of an artifact of human manufacture imbedded in Roxana loess, classed as Altonian substage of the Wisconsin stage of the Pleistocene, of an age of 35,000 to 40,000 years, contributes to the determination of the age of man in the New World.
Immunodiffusion: Detection of a Murine Leukemia Virus (Rauscher)
Authors: Fink Mary Alexander , Cowles Carolyn A.
Published: October 2006

Homologous and heterologous antiserums from several species of animals have been prepared against the Rauscher murine leukemia virus. The Ouchterlony technique, adapted to very small quantities, has been used to demonstrate at least two or three antigens in Rauscher virus preparations. Both infected-host materials and tissue-culture fluids were used as antigens. When monkey antiserum was used, one of the Rauscher virus antigens cross-reacted with an antigen in the virus strains isolated by Friend and Moloney, but there was apparently no reaction with the Moloney virus when guinea-pig antiserum was used.
Transhydrogenation in Root Tissue: Mediation by Carbon Dioxide
Authors: Ting Irwin P. , Dugger W. M.
Published: October 2006

The C
14
O
2
incorporated into organic acids by excised corn roots is released with an estimated halftime of 3 hours. Homogenates of root tissue can mediate these reactions by coupling, in series, phosphoenolpyruvate carboxylase, diphosphopyridine nucleotide malic dehydrogenase, and triphosphopyridine nucleotide malic dehydrogenase. An important consequence is the transfer of hydrogen from reduced diphosphopyridine nucleotide to triphosphopyridine nucleotide which is then reduced.
Shaping and Discriminative Control of Underwater Click Vocalizations in a California Sea Lion
Authors: Schusterman Ronald J. , Feinstein Stephen H.
Published: October 2006

A captive sea lion (
Zalophus californianus
) which had never before produced clicking sounds in the laboratory was first conditioned to vocalize in air and subsequently learned to emit underwater clicks. Clicking was brought under control by differential reinforcement procedures. Vocalization as an indicator response may be useful in the comparative study of discriminative behavior.
Gibberellin and Growth in Isolated Wheat Embryos
Authors: Kefford N. P. , Rijven A. H. G. C.
Published: October 2006

Gibberellic acid promoted elongation growth in the coleoptiles and leaves of embryos from gamma-irradiated wheat grains whether the embryos were isolated or attached to the endosperm. Thus gibberellic acid affected this growth directly rather than indirectly through an effect upon endosperm. However, root growth was promoted by gibberellic acid only on embryos attached to endosperm, suggesting an indirect effect of gibberellic acid upon growth.
Tobacco Seedlings: Damage by Excessive Nitrogen Lessened by Added Phosphorus
Authors: Pal N. L. , Ojha R. J.
Published: October 2006

Concentrations of nitrogen (as ammonium nitrate) of 50 kilograms per hectare and greater are toxic to tobacco seedlings; symptoms are poor growth and white leaves. The leaves have markedly less chlorophylls (especially chlorophyll a) and more carotene and xanthophyll than seedlings grown in media low in nitrogen. These ill effects are aggravated by short supply of phosphorus; they can be counteracted by more liberal supply of phosphorus.
Endoplasmic Reticulum in Rat Renal Interstitial Cells: Molecular Rearrangement after Water Deprivation
Authors: Bulger Ruth Ellen , Griffith Lyle Dean , Trump Benjamin F.
Published: October 2006

Cylindrical bodies in renal interstitial cells of dehydrated rats are confluent with membranes of endoplasmic reticulum. The cylinder walls, composed of helically arranged pentagonal tubules, may represent a molecular rearrangement of the membrane structure. The cylinders may represent a morphologic expression of altered ergastoplasmic function possibly related to the production of concentrated urine.
Spontaneous Mutation Rates at Five Coat-Color Loci in Mice
Authors: Schlager Gunther , Dickie Margaret M.
Published: October 2006

Examination of 1.5 million mice yielded natural mutation rates estimated from 5.2 million gene reproductions at five specific coat-color loci. The average rates were 11.1 × 10
-6
for forward mutations and 2.7 × 10
-6
for reverse mutations. Differences between the frequencies of mutations at the individual loci were evident.
Polymorphism of Lactate Dehydrogenase in Gelada Baboons
Authors: Syner Frank N. , Goodman Morris
Published: October 2006

In a group of 21 gelada baboons, three different lactate dehydrogenase patterns were observed after starch-gel electrophoresis of tissue extracts. The patterns indicate that a mutation has occurred in this population in the gene responsible for the A-subunit. The normal and variant homozygotes each contain five isozymes, those containing the A subunit having characteristically different electrophoretic mobilities. The heterozygote contains the expected 15 isozymes.
Enhanced Distress Vocalization through Selective Reinforcement
Authors: Hoffman H. S. , Schiff D. , Adams J. , Searle J. L.
Published: October 2006

Eighteen Peking ducklings were imprinted and tested for their tendency to emit distress calls during the presentation and withdrawal of the imprinted stimulus. A subsequent arrangement in which each distress vocalization led to a 5-second presentation of the imprinted stimulus resulted in an enhanced tendency to emit distress calls.
Radium Isotope Accumulation in Animal Thyroids
Authors: Van Middlesworth L. , Correa Pelayo , Perkins R. W. , Keane A. T.
Published: October 2006

Uranium and thorium daughters are ten times more concentrated in thyroids from some bovine animals than in the teeth of the same animals. These radioactive isotopes are believed to be from natural sources, but their resulting annual dosage of thyroid radiation has exceeded that from iodine-131 fallout.
Hyperphagia in Ruminants Induced by a Depressant
Authors: Baile Clifton A. , Mayer Jean
Published: October 2006

Attempts at causing ventromedial hyperphagia in ruminants have been hitherto unsuccessful. In our experiments perfusion of the ventriculocisternal system with pentobarbital caused marked hyperphagia. This suggests that the ventromedial hypothalamic area is functioning in ruminants, probably as in monogastric animals, by inhibiting the lateral area.
Gaseous-Diffusion Porometer for Continuous Measurement of Diffusive Resistance of Leaves
Authors: Slatyer R. O. , Jarvis P. G.
Published: October 2006

We describe a porometer that enables continuous monitoring of the stomatal diffusive resistance of leaves. The flux is measured of a gas-such as nitrous oxide—diffusing through a leaf that divides an enclosing chamber into two compartments. Nitrous oxide is added in known concentration to the airstream passing through the compartment on one side of the leaf and is recovered from the airstream passing through the opposite compartment. From measurements of the difference in concentration across the leaf and of the flux, the diffusive resistance of the leaf to N
2
O is calculated; this value, adjusted for resistance external to the leaf, gives a continuous record of internal diffusive resistance. This record can be made simultaneously with measurements of transpiration and photosynthesis.
Pentobarbital Sodium: Variation in Toxicity
Authors: Lindsay H. A. , Kullman V. S.
Published: October 2006

The survival rate of groups of female mice given a standard dose of pentobarbital sodium varied during a 12-hour period. When survival rate was plotted against time, a curve with several inflections was described.
Chromosomal Aberrations in a Population of Ground Squirrels
Authors: Nadler Charles F. , Hughes Charles E.
Published: October 2006

Chromosomes were analyzed from a population of
Spermophilus beldingi
that included an adult female and three juveniles from the same burrow. All animals had a diploid number of 30. The adult and a juvenile female from the burrow had identical aberrant karyotypes containing an unpaired submetacentric and a minute metacentric chromosome. A familial aberration involving an X chromosome, without phenotypic alteration, is most probable.
Lithium-Drifted Germanium Detectors: Applications to Neutron-Activation Analysis
Authors: Schroeder Gerald L. , Kraner Hobart W. , Evans Robley D. , Brydges Thomas
Published: October 2006

Lithium-drifted germanium detectors for high-resolution gamma-ray spectroscopy reduce the need for wet chemistry in neutron-activation analysis. Problems in fields as diverse as geochemistry and the history of 15th-century printing have proved susceptible to this analytic technique.
Intracellular Localization of Growth Hormones in Plants
Authors: Liao Shu-huei , Hamilton Robert H.
Published: October 2006

Autoradiographic studies of Allium cernuum and
Vicia faba
root-tip cells treated with indoleacetic acid-methyl-C
14
or 2,4-dichlorophenoxyacetic acid-carboxyl-C
14
revealed nuclear and cytoplasmic labeling of the cells. The cytoplasmic labeling decreased with time after the removal of the labeled auxin, but nuclear and chromosomal labeling was retained for at least 120 hours.
Electron Microscopic Autoradiography of Rabbit Reticulocytes Active and Inactive in Protein Synthesis
Authors: Miller Alexander , Maunsbach Arvid B.
Published: October 2006

Electron microscopic autoradiography indicates that only a fraction of ribosome-containing reticulocytes (from phenylhydrazine-treated rabbits) is capable of active protein synthesis in vitro. Ribosomes, and, indeed, polyribosomes, do not appear to limit the rate of protein synthesis.
Quenchable High-Pressure Polymorph of Zinc Selenate
Authors: Pistorius Carl W. F. T.
Published: October 2006

A new quenchable high-pressure form of zinc selenate (ZnSeO
4
) was produced by subjecting the low-pressure modification to 40 kilobars at 400°C for 30 minutes. The new form is orthorhombic, space group
D

2
h

17
-
Cmcm
. The cell constants at 29°C are:
a
, 5.511 angstroms;
b
, 8.110 angstroms; and
c
, 6.585 angstroms. The calculated density is 4.70 grams per cubic centimeter in comparison with 4.61 grams per cubic centimeter for the low-pressure modification. This implies a volume change of 2 percent at the transition.
Blood Flow in the Microvasculature of the Conjunctiva of Man
Authors: Wells Roe E. , Schildkraut E. Robert , Edgerton Harold E.
Published: October 2006

Cinephotomicrography of capillary blood flow in conjunctival vessels of man were carried out at 116 pictures per second. Red cells did not move in streamlines but rather in a heterogenous mixing type of flow. Flow in vessels of patients whose red cells were grossly aggregated was very slow and often stagnant.
Middle Devonian Lunar Month
Authors: Aveni Anthony F.
Published: October 2006

Simple dynamical calculations regarding the number of lunar months in the Middle Devonian year differ slightly from results obtained from periodicities found in the breeding of corals.
Flavin Mononucleotide Control of Glycolic Acid Oxidase and Photorespiration in Corn Leaves
Authors: Tregunna Bruce
Published: October 2006

Enzyme preparations from young corn shoots lacked the coenzyme, flavin mononucleotide, that is required for glycolic acid oxidation. When the coenzyme was added to the shoots, the rate of carbon dioxide production during photosynthesis increased. Shoots of wheat or oats did not lack the coenzyme.
Low-Energy Protons: Average Flux in Interplanetary Space during the Last 100,000 Years
Authors: Lal D. , Venkatavaradan V. S.
Published: October 2006

The radioactivity of aluminum-26 in two cores of Pacific sediments is an order of magnitude higher than was expected, as a result of its production by cosmic-ray interactions in the terrestrial environment. The higher activity can be explained only by postulating influx with extraterrestrial cosmic dust that had been exposed to significant flux of energetic particles capable of producing nuclear interactions. These particles may well be the "solar" cosmic rays that are sporadically accelerated by Sun during certain solar flares, since the steady galactic cosmic-ray flux is inadequate. The long-term average flux of low-energy protons in interplanetary space, required to yield the observed rate of influx of aluminum-26, is deduced on the basis of certain assumptions.
Enzyme Changes in Neurons and Glia during Barbiturate, Sleep
Authors: Hamberger A. , Hydén H. , Lange P. W.
Published: October 2006

During barbiturate sleep of rabbits, the succinoxidase activity in isolated neurons and glia from the caudal part of the reticular formation was lower than that during physiological sleep. No rhythmical, inverse enzyme changes were detected in barbiturate sleep in the neuron-glia unit, such as were found in physiological sleep.
Mammary Glands of Pregnant Rats: Development Stimulated by Licking
Authors: Roth Lorraine L. , Rosenblatt Jay S.
Published: October 2006

At the end of gestation, the mammary glands of pregnant rats that have been prevented from licking their ventral surfaces by neck collars are about 50-percent less developed than those of control animals. Neither the burden nor the stress effect of the collar is an alternative explanation. A considerable proportion of mammary development during pregnancy is thus caused by the female's own licking.
Dislocations in a Campo del Cielo Meteorite
Authors: Ashbee K. H. G. , Vassamillet L. F.
Published: October 2006

Thin-film transmission electron microscopy showed that a Campo del Cielo meteorite has an immobile dislocation network of high density. The network is not related to attendant precipitates.
Population Flushing with Sexually Sterile Insects
Authors: Monro J.
Published: October 2006

In theory, populations of animals can be displaced by overloading a resource with introduced sterile animals. The theory was tested on natural populations of the Queensland fruit-fly
Dacus tryoni
Frogg. Three of four treated populations declined sharply within 2 days after sterile flies had been introduced. This procedure may be useful both as a tool in experimental ecology and as a means of controlling pests.
Actin-Myosin Interaction: Inhibition of the Myosin Adenosine Triphosphatase by Actin
Authors: Barron S. , Eisenberg E. , Moos C.
Published: October 2006

In the absence of magnesium ion, the addition of actin to myosin in a 1 :4 ratio has a strong inhibitory effect on the adenosine triphosphatase activity, in contrast to the well-known activating effect of actin in the presence of magnesium ion. This finding suggests that both effects result from a conformational change in the active site of the myosin adenosine triphosphatase.
Chromosome Changes Induced by Infections in Tissues of
Rhynchosciara angelae
Authors: Pavan Crodowaldo , Basile Renato
Published: October 2006

The main effects of two infections, one by a protozoan and the other by a virus, in cells of
Rhynchosciara angelae
(Diptera, Sciaridae) are an increase in cell size and changes in the size, shape, and behavior of the chromosomes. The X chromosome of some cells reacts differently from the autosome to the protozoan infection. Some chromosomes show specific, easily traceable points after infection by the virus. Some of the effects of these infections may be similar to the effects of infective agents in other organisms.
Interferon: Lack of Detectable Uptake by Cells
Authors: Buckler Charles E. , Baron Samuel , Levy Hilton B.
Published: October 2006

No interferon, or at most a small fraction of that applied, is taken up by cells during the period of induction of antiviral activity. The lack of detectable adsorption was not influenced either by the concentration of interferon or the volume. The results were similar in both chicken and mouse systems.
Seroprimatology of Chimpanzees: Blood-Group Distribution as a "Racial" Characteristic
Authors: Moor-Jankowski J. , Wiener Alexander S. , Kratochvil Clyde H. , Fineg Jerry
Published: October 2006

Significant differences in the distribution of human-type and simian-type blood groups have been demonstrated in chimpanzees classified into subspecies or "races" on the basis of morphological traits. The differences in chimpanzees are analogous to racial differences in the distribution of blood groups in man.
Progesterone Retards Postpartum Involution of the Rabbit Myometrium
Authors: Goodall Forrest R.
Published: October 2006

Postpartum involution of the uterus was significantly reduced in rabbits by immediate and repeated injections of progesterone. Progesterone had no effect if the injections commenced 24 hours after delivery. The decrease in concentration of progesterone that accompanies birth results in release of proteolytic and other degradative enzymes from subcellular particles; these enzymes cause the involution, and, once the enzymes are released into the cellular milieu, progesterone has no effect.
Ornithine-Urea Cycle Enzymes in the African Lungfish,
Protopterus aethiopicus
Authors: Janssens Peter A. , Cohen Philip P.
Published: October 2006

The presence of all five enzymes of the ornithine-urea cycle has been demonstrated in the liver of the African lungfish
Protopterus aethiopicus
. Levels of activity of the rate-limiting enzymes, carbamoyl phosphate synthetase and argininosuccinate synthetase, are similar to those in the premetamorphic tadpole of
Rana catesbeiana
and considerably lower than the levels reported for other ureotelic animals. They are thus consistent with the predominantly ammonotelic metabolism of the lungfish in an aquatic environment.
Zonal Ultracentrifuge for the Separation of Ribosomal Subunits
Authors: Klucis E. S. , Gould H. J.
Published: October 2006

Ribosomal subunits were prepared by means of the Anderson zonal ultracentrifuge. With this technique it is possible to separate more than 300 milligrams of subunits with complete resolution in a single run, as compared with about 2 milligrams with conventional rotors. Superior resolution is achieved in the zonal ultracentrifuge, affording possibilities for the detection and preparation of minor ribosomal components.
Adrenocorticotrophin-Releasing Hormone in Peripheral Blood: Increase during Stress
Authors: Anderson Evelyn
Published: October 2006

Significant amounts of adrenocorticotrophin-releasing hormone appear in the peripheral blood under conditions of physiological stress. Associated with the appearance of this neurohormone is an increased antidiuretic activity. The neurohormone presumably enters the general circulation by way of the portal vessels of the anterior pituitary gland.
Native and Renatured Transfer Ribonucleic Acid
Authors: Lindahl Tomas , Adams Alice
Published: October 2006

Transfer ribonucleic acid, isolated under conditions in which the original macromolecular structure is never denatured, is indistinguishable from transfer ribonucleic acid prepared by conventional methods involving denaturing steps. This finding is consistent with the absence of direct genetic control of the formation of macromolecular structure of transfer ribonucleic acid.
Heterogeneous Catalysis: Effect of an Alternating Electric Field
Authors: Lee Vin-Jang
Published: October 2006

Oxidation of carbon monoxide was studied in a static reactor at 123° ± 1°C, with NiO as catalyst. An alternating electric field of about 22,000 volts per centimeter, peak to peak, was applied normal to the catalytic surfaces. The rate of oxidation was thereby enhanced by a factor of 6 at 100 cycles per second, with maximum enhancement at between 100 and 200 cycles per second.
Chromosomes from Testicular Preparations of Lepidoptera
Authors: Miller Lee D. , Miller Susan M.
Published: October 2006

Typical elongate, beaded chromosomes have been observed in squash preparations of testicular tissue of the butterfly
Speyeria aphrodite
(Fabricius), the first demonstration of relatively uncondensed chromosomes in the Lepidoptera.
Branched-Chain Fatty Acids in Sediments
Authors: Leo Richard F. , Parker Patrick L.
Published: October 2006

Branched-chain (iso and anteiso) fatty acids were isolated from marine sediments from several environments. The relatively high ratio of branched-chain to straight-chain fatty acids for the even-numbered carbon molecules suggests a bacterial origin for the branched-chain isomers. The branched-chain fatty acids are present in the Green River shale. Possible geochemical implications are suggested.
Erythropoietin: Production by a Particulate Fraction of Rat Kidney
Authors: Contrera Joseph F. , Gordon Albert S.
Published: October 2006

An erythropoietic factor was extracted with hypotonic phosphate buffer from the kidneys of hypoxic rats. Normal rat serum enhanced the activity of this factor, which is associated with the light mitochondrial fraction. The data suggest that the renal factor is not physiologically active unless it interacts with a serum carrier or activator, or that the factor may be an enzyme which produces erythropoietin from some serum substrate.
Upper Atmosphere and Ionosphere of Mars
Authors: Donahue T. M.
Published: October 2006

It is argued that the single-layer ionosphere at 125 kilometers discovered in the Mariner IV occultation experiment is an F1 region coinciding with the ultraviolet photoionization peak. The CO
2
density there must be of the order of 10
11
molecules per cubic centimeter. Such a density is consistent with the properties of the lower atmosphere by Mariner IV and the temperature model of Chamberlain and McElroy if the atmosphere is mainly CO
2
below 70 kilometers. The absence of an F2 region can be explained even if the density ratio of O to CO
2
is 100 at 230 kilometers on the basis of the rapid conversion of O
+
to O
2
by CO
2
. Thus a model with an exospheric temperature of 400°K, a modest degree of CO
2
dissociation, and diffusive separation above 70 kilometers is possible.
Immunochemical Characterization of Polyribonucleotides
Authors: Panijel Jacques , Souleil Claude , Cayeux Philippe
Published: October 2006

The degree of organization of polyribonucleotides determines their modalities of reaction with antibodies (NG-I) which are present in serums of animals hyperimmunized with ribosomes. The immunochemical behavior of the highly helical two-stranded complex of polyadenylic acid and polyuridylic acid and the corresponding three-stranded complex of one molecule of polyadenylic acid and two molecules of polyuridylic acid can be determined from examination of the associating and nonassociating mixtures of polyadenylic and polyuridylic acids. The immunochemical characteristics of various forms of polyinosinic acid in solution are described.
Retention of Potential to Differentiate in Long-Term Cultures of Tooth Germs
Authors: Main James H. P.
Published: October 2006

When tooth germs derived from 14-day mouse embryos were cultured on gelatin sponges in vitro for 37 days, they lost their characteristic morphology, appearing as a layer of undifferentiated epithelium on the sponge surface, with the mesenchymal cells scattered throughout the interstices. These cultures were then transplanted subcutaneously into isologous, newborn recipients and, over a period of 56 days, developed into incisor teeth that were almost perfect in shape and structure.
Growth in Microculture of Single Tobacco Cells Infected with Tobacco Mosaic Virus
Authors: Chandra Naresh , Hildebrandt A. C.
Published: October 2006

Single tobacco callus cells with or without tobacco mosaic virus inclusion bodies from systemically infected
Nicotiana tabacum plants
were grown in microcultures. The culture medium consisted of mineral salts and sucrose; it also contained coconut milk. Out of 100 inclusion-bearing cells and 150 inclusion-free cells, 10 and 70 cultured cells divided; eventually 5 and 65 cells, respectively, formed single cell clones. The 5 clones derived from inclusion-bearing cells, and all but 3 of 40 clones from inclusion-free cells, showed virus inclusions in somne cells. The virus could not be detected in three inclusion-free clones by local lesion assay. The results suggest single-cell culture methods for differentiating virus-free plants from cells of pathogen-infected plants.
Estrous Cycle in the Rat: Effects on Self-Stimulation Behavior
Authors: Prescott R. G. W.
Published: October 2006

The performance of female rats, in pressing a bar for electrical stimulation of the hypothalamus, changes during the estrous cycle. Highest bar-pressing rates accompany the appearance of vaginal cornification. This increase is not an artifact of increased spontaneous activity at estrus, although the factors underlying these changes in activity may also mediate the changes in self-stimulation behavior.
Replication of Chloroplast DNA of Tobacco
Authors: Green Beverley R. , Gordon Milton P.
Published: October 2006

An experimental method has been designed for determining the relative rates of replication of the chloroplast and nuclear DNA's of
Nicotiana tabacum
. By this method chloroplast DNA in week-old seedlings is being replicated several times faster than nuclear DNA.
Pleistocene Age Determinations from California and Oregon
Authors: Richards Horace G. , Thurber David L.
Published: October 2006

Mollusks have been collected from Pleistocene marine deposits at Tomales Bay, California, and Cape Blanco, Oregon. Dating by the carbon-14 and thorium-230-uranium-234 methods suggests that the shells are at least 33,000 years old. The more probable age of the Tomales Bay locality is ≥ 50,000 years.
Rotation Technique in Radially Symmetric Electron Micrographs: Mathematical Analysis
Authors: Norman Richard S.
Published: October 2006

The rotation operation of order
m
operating on a signal removes all spatial frequencies not multiple to
m
. Anomalous reinforcements, causing misinterpretation, can be discounted without following previously suggested restrictions. The improvement in signal-to-noise ratio is less than
m
, in contrast to signal averaging of electrophysiology. A dove prism and stroboscope can implement the technique.
Auxin-Induced Ethylene Formation: Its Relation to Flowering in the Pineapple
Authors: Burg Stanley P. , Burg Ellen A.
Published: October 2006

Within 1 day after pineapple plants are treated with naphthalene acetic acid they begin producing ethylene. It is suggested that applied auxins mimic the action of ethylene by stimulating ethylene formation, and that ethylene, not auxin, causes pineapples to flower.
D(—)-Lactate Dehydrogenase in Lower Fungi
Authors: Gleason Frank H. , Nolan Richard A. , Wilson Allan C. , Emerson Ralph
Published: October 2006

A lactate dehydrogenase, specific for nicotinamide-adenine dinucleotide and D(—)-lactate, has been detected in extracts from two fungi of the order Leptomitales (Oomycetes). Several fungi of this order carry out a lactic acid fermentation under conditions of reduced oxygen tension.
Effect of Interferon on Early Interferon Production
Authors: Levy Hilton B. , Buckler Charles E. , Baron Samuel
Published: October 2006

Chick embryo cells given prior treatment with interferon make new interferon earlier and in larger quantities upon stimulation with Chikungunya virus than cells not so treated. By the criterion of loss of sensitivity to actinomycin, the time needed for formation of messenger RNA for interferon was decreased in the primed cells. Thus interferon affects virus action within 1 hour after infection.
Pentagonal Aggregation of Virus Particles
Authors: Milman Gregory , Uzman Betty G. , Mitchell Anja , Langridge Robert
Published: October 2006

Virus aggregates with a unique fivefold axis have been observed in the electron microscope.
Quantum Yield of Oxygen Evolution and the Emerson Enhancement Effect in Deuterated
Chlorella
Authors: Bedell Glenn , Govindjee
Published: October 2006

The maximum quantum yield of oxygen evolution in deuterated chlorella is found to be 0.075, while normal chlorella showed, in parallel experiments, a value of 0.10. Deuterated
Chlorella vulgaris
showed a decline in the quantum yield of oxygen evolution ("red drop") beginning at 680 millimicrons and a clear Emerson enhancement effect qualitatively similar to that obtained in normal chlorella cells. However, the ratio of quantum yield at 680 to that at 710 millimicrons was about 1.5 times higher in normal than in deuterated chlorella cells. Action spectra of the Emerson enhancement effect in deuterated chlorella also are qualitatively similar to those of normal cells.
Visual Acuity in a Stumptail Macaque
Authors: Yarczower M. , Wolbarsht M. L. , Galloway W. D. , Fligsten K. E. , Malcolm R.
Published: October 2006

Visual acuity in a normal stumptail macaque is 1.4 minutes of arc—similar to man's. Destruction of the fovea by photocoagulation decreased acuity to 9 minutes of arc. These facts suggest that the fovea in the macaque has the same physiological role in visual acuity as in man.
Sea Cucumber Sibling Species: Polypeptide Chain Types and Oxygen Equilibrium of Hemoglobin
Authors: Manwell Clyde
Published: October 2006

The hemoglobin of the "thin" sibling species of
Thyonella gemmata
(phylum: Echinodermata; class: Holothuria) has three electrophoretically distinct polypeptide chains. In "stout" sibling species of
T. gemmata
there are only two chain types. These results account for the greater number of multiple hemoglobins in "thins" than in "stouts," as well as for differences in the amounts of some of the multiple hemoglobins when comparisons are made of hemolyzates of erythrocytes from the water vascular system and from the main body cavity of the "thin" but not the "stout" sibling species.
Availability of a Cationic Herbicide Adsorbed on Clay Minerals to Cucumber Seedlings
Authors: Weber Jerome B. , Scott Donald C.
Published: October 2006

Montmorillonitic and kaolinitic clays are effective in decreasing the toxicity of paraquat, an organic cation, to cucumber plants. The cation was adsorbed on the surface of the kaolinite clay particles and slowly became available to the plants. When it was adsorbed in the interlayer spacings of the montmorillonite clay, however, it was not available to the plants.
Actin: Volume Change on Transformation of G-Form to F-Form
Authors: Ikkai Takamitsu , Ooi Tatsuo , Noguchi Hajime
Published: October 2006

The volume change occurring on polymerizing actin was measured by dilatometry. A large positive value of + 391 ml/mole was obtained for the volume change during the transformation of G- to F-actin. This large increase in volume could be interpreted as arising from the local change in the ordered water structure on the protein's surface at polymerizing sites.
Cytochemical Localization of Lactate Dehydrogenase in Muscular Dystrophy of the Mouse
Authors: Fahimi H. D. , Roy P.
Published: October 2006

By use of phenazine methosulfate and the "incubation mixture film method," lactate dehydrogenase activity has been demonstrated in the dystrophic muscle fibers of strain 129 mice. The results indicate that for demonstration of lactate dehydrogenase activity in dystrophic muscle fibers phenazine methosulfate is necessary. This finding is typical for the "white" muscle fibers in the normal muscle and suggests that the dystrophy affects primarily the "white" muscle fibers.
Reserpine: Inhibition of Olfactory Blockage of Pregnancy in Mice
Authors: Dominic C. J.
Published: October 2006

Failure of pregnancy in newly mated female mice exposed to fresh urine from alien males is prevented by administration of reserpine, at 6.25 micrograms per day per female, on days 1 to 5
post coitum
—that is, throughout the period of exposure to male urine and for 2 more days. Since reserpine is known to suppress the inhibitory center in the hypothalamus controlling the release of prolactin, inhibition by reserpine of the blockage of pregnancy provides a strong direct indication of hypothalamic mediation in the male-induced failure of pregnancy in mice.
Antiserum to Immunoglobulin A: Inhibition of Cell-Mediated Demyelination in Tissue Culture
Authors: Winkler G. F. , Arnason B. G.
Published: October 2006

Lymph node cells from rats immunized with sciatic nerve in Freund's adjuvant demyelinate trigeminal ganglion cultures. Rabbit antiserum to rat immunoglobulin A blocks this cytodestructive event. The antiserum may act by combining with IgA on the lymphoid cell surface, preventing the interaction of cell-bound antibody and tissue antigen.
Polysomes and Protein Synthesis in Cells Infected with a DNA Virus
Authors: Sydiskis Robert J. , Roizman Bernard
Published: October 2006

In HEp-2 cells infected with herpes simplex virus the rate of protein synthesis at first decline, is stimulated between 4 and 8 hours after infection, and progressively and irreversibly declines from 9 to 16 hours later. The increase and decrease in rates coincide with corresponding changes in the amounts of cytoplasmic polysomes and amounts of labeled amino acids in nascent peptides bound to polysomes. The data indicate that (i) early and late inhibition and intervening stimulation of protein synthesis are due to the corresponding breakdown and formation of polysomes, and (ii) the bulk of viral proteins is probably made on cytoplasmic polysomes.
Calibration of β Gauges for Determining Leaf Water Status
Authors: Jarvis P. G. , Slatyer R. O.
Published: October 2006

The recent development of β gauges for the indirect determination of the water status of plants has had a widespread impact on plant ecological-physiological research. Calibration of these instruments has, however, been tedious and cumbersome, involving repeated simultaneous measurements of β absorption and leaf water content. This procedure can be much simplified, as long as the β absorption at a single known relative water content is measured, together with the turgid and dry weights of a sample of leaf discs.
Influence of the Lethal Yellow (A
y
) Gene on Estrous Synchrony in Mice
Authors: Bartke Andrzej , Wolff George L.
Published: October 2006

Introduction of an adult male induces partially synchronous estrus in female laboratory mice that have been caged in groups. In the inbred YS/ChWf strain, this effect was observed only when the male was nonyellow (
aa
), while males heterozygous for the lethal yellow allele (

A
y
a

) failed to induce synchrony.
Glucuronidase Gene Expression in Somatic Hybrids
Authors: Ganschow Roger
Published: October 2006

Evidence at the enzymic level confirms the dual origin of the genetic material of somatic hybrids. Furthermore, the pattern of glucuronidase gene expression in somatic hybrids qualitatively resembles that in livers of animals heterozygous for this gene.
Satellite Deoxyribonucleic Acid from
Bacillus cereus
Strain T
Authors: Douthit H. A. , Halvorson H. O.
Published: October 2006

DNA isolated from exponentially growing cultures of
Bacillus cereus
T has a single component (density 1.696 g cm
-3
) in a cesium chloride density gradient whereas DNA isolated from spores shortly after the initiation of germination has two components: a major one (density 1.696 g cm
-3
) and a satellite (density, 1.725 g cm
-3
). The DNA of both components is double-stranded. By the first cell division there is no satellite DNA.
Chromosome Aberrations: Increased Incidence in Bone Marrow of Continuously Irradiated Rats
Authors: Chlebovský Ondrej , Praslička Milan , Horák Jindrich
Published: October 2006

The number of chromosomal aberrations in the bone marrow of continuously irradiated rats temporarily decreases after exposure, and then increases as the total dose and time after irradiation increase. This increase in aberrations is greater than that expected as a result of age alone.
Absence of Short-Term Variability of CTA 102
Authors: Bologna J. M. , McClain E. F. , Sloanaker R. M.
Published: October 2006

Short-time variations in intensity of about 40 percent, with a period of the order of 100 days, have been reported for the quasistellar radio source CTA 102 at 32.5-centimeter wavelength. We have observed CTA 102 at 25.5-centimeter wavelength over a 67-day, period and have detected no significant variations of intensity.
Radiocarbon Dating of Coastal Peat, Barrow, Alaska
Authors: Brown Jerry , Sellmann Paul V.
Published: October 2006

A buried, frozen section of peat from sea level yielded radiocarbon dates between 700 and 2600 B.C.; it suggests burial by a transgressing sea.
Intravenous Injection of Thalidomide in Pregnant Rabbits
Authors: Fox R. R. , Sawin P. B. , Crary Dorcas D. , Wuest H. M.
Published: October 2006

When administered orally to pregnant strain III rabbits, thalidomide is teratogenic to their fetuses. However, when the drug is injected intravenously to females of the same genetically controlled stock, it has no observable effect. This finding indicates that a metabolite of thalidomide formed in the intestinal tract may be the real teratogenic agent.
Inhibition of Protein Synthesis: A Mechanism for the Production of Impaired Iron Absorption
Authors: Greenberger Norton J. , Ruppert Richard D.
Published: October 2006

Treatment of rats with cycloheximide results in a defect in intestinal iron transport. A similar defect occurs after the parenteral administration of iron. Under both conditions there is impaired uptake of iron into the mucosal cells as well as defective transfer from the intestinal mucosa. It is suggested that the interference in iron transport may be due to a deficiency of an unidentified carrier substance.
Simultaneous Changes in Visual Separation Threshold and Voltage of Cortical Alpha Rhythm
Authors: Anliker James
Published: October 2006

An automated psychophysical method allows a human subject to track his own separation threshold for two flashes delivered in sequence without interfering with the simultaneous recording of the alpha rhythm of his electroencephalogram. A systematic rise in this threshold is observed when the alpha voltage declines from its normal alert level. This suggests that an increase in the minimum resolvable temporal sequence may contribute to the development of the negative time errors associated with drowsiness and sleep.