bluuebunny/crossref_metadata_2025 huggingface dataset:
Isopycnic Separation of Subcellular Components from Poliovirus-Infected and Normal HeLa Cells
Authors: Baltimore David , Huang Alice S.
Published: October 2006

A rapid method for determining the density of ribonucleoprotein particles and complexes has been developed. The method involves glutaraldehyde fixation of sucrose gradient fractions and immediate centrifugation for 5 hours through preformed cesium chloride gradients. There is little or no aggregation of particles, so that components which co-sediment in sucrose gradients are resolved by the cesium chloride gradient. By this method the densities of HeLa cell ribosomes, polyribosomes, and subribosomal particles have been determined. Furthermore, the poliovirus replication complex has been separated from polyribosomes and its density has been found to be unaffected by treatment with ethylenediaminetetraacetic acid.
Erythromycin-Resistant Mutant of
Escherichia coli
with Altered Ribosomal Protein Component
Authors: Tanaka Kentaro , Teraoka Hiroshi , Tamaki Mikio , Otaka Eiko , Osawa Syozo
Published: October 2006

Erythromycin combines with 50
S
ribosomal subunit of an erythromycin-sensitive
Escherichia coli
(strain Q13), while ribosomes from an erythromycin-resistant mutant from this strain have little affinity for the antibiotic. A protein component of the 50
S
subunit of the mutant strain is distinct from that of the parent Q13 strain.
Insect Hormone Activity of
p
-(1,5-Dimethylhexyl)benzoic Acid Derivatives in
Dysdercus
species
Authors: Suchý M. , Sláma K. , Šorm F.
Published: October 2006

Derivatives of
p
-(1,5-dimethylhexyl)benzoic acid are juvenile hormone analogs with selective action on the hemipteran insects of the family Pyrrhocoridae. Their juvenile hormone activity is constant on five species of
Dysdercus;
it is about ten times lower on
Pyrrhocoris
, and no activity has been detected on hemipterans of some other families. Absence of profound species-specific variations in the activity suggests that the most active compounds of this type can be used as selective pesticides against all species of
Dysdercus
.
Microsomal
N
-Demethylation, by a Cotton Leaf Oxidase System, of 3-(4′-Chlorophenyl)-1,1-Dimethylurea (Monuron)
Authors: Frear D. S.
Published: October 2006

A cotton leaf microsomal oxidase system that
N
-demethylates 3-(4′-chlorophenyl)-1,1-dimethylurea (monuron) to 3-(4′-chlorophenyl)-1-methylurea has been partially characterized. The enzyme system is associated with a microsomal fraction separated by differential centrifugation and requires molecular oxygen as well as either the reduced form of nicotinamide adenine dinucleotide phosphate or the reduced form of nicotinamide adenine dinucleotide as cofactors.
Estimating the Number of Animals: A Rapid Method for Unidentified Individuals
Authors: Hanson William R.
Published: October 2006

A proposed model yields the density of a mobile population from quick, cursory surveys in which the observer identifies none of the animals. When the spaces on which animals were seen are successively removed, the decline in the counts permits estimation of the average probability of seeing a given animal. The method showed promise in initial trials.
Recombination of Nonchromosomal Mutations: A Three-Point Cross in the Green Alga
Chlamydomonas reinhardi
Authors: Gillham Nicholas W. , Fifer William
Published: October 2006

The heterothallic, unicellular green alga
Chlamydomonas reinhardi
possesses both chromosomal and nonchromosomal systems of inheritance. Mutations belonging to the latter system are capable of recombination. The experiments reported show that double and triple recombinants can be obtained from crosses employing three phenotypically distinct mutations and that certain pairs of mutants recombine more freely than others.
Mycobacterium tuberculosis
in Macrophages: Effect of Certain Surfactants and Other Membrane-Active Compounds
Authors: Hart P. D'Arcy
Published: October 2006

Some compounds, not directly inhibitory or enhancing, nevertheless influence growth of tubercle bacilli in macrophages in cell culture. They include certain surfactants whose effects can be varied by their structural design. The compounds are probably stored in cell lysosomes. They can interact with various membranes to affect permeability. The anti- and protuberculous surfactants differ in such interaction and also in effect on lysosomal enzyme activity in infected macrophages. A link between the effect on lysosomal membranes and on tuberculous infection is suggested.
Red-Cell Transport Defect in Patients with Cystic Fibrosis and in Their Parents
Authors: Balfe J. W. , Cole C. , Welt L. G.
Published: October 2006

The ouabain-sensitive and the ethacrynic acid-sensitive sodium efflux from erythrocytes of patients with cystic fibrosis are both decreased. Furthermore, the ouabain-sensitive adenosine triphosphatase activity is diminished in the red blood cell ghosts of these patients. Perhaps of greater significance is the fact that ethacrynic acid-sensitive sodium efflux is clearly diminished in the erythrocytes of the asymptomatic parents of these sick children. This defect in sodium transport may be valuable for detecting the heterozygous carrier state.
X-Ray Line and Continuum Spectra of Solar Flares from 0.5 to 8.5 Angstroms
Authors: Meekins John F. , Kreplin Robert W. , Chubb Talbot A. , Friedman Herbert
Published: October 2006

Two crystal spectrometers aboard the orbiting solar observatory OSO-4 cover the wavelength ranges 0.5 to 3.9 angstroms and 1.0 to 8.5 angstroms. Within this range, there appear emission lines from hydrogen-like and helium-like states of calcium, sulfur, silicon, magnesium, and aluminum. The Mg XII Lyman-α is present strongly in all x-ray flares. The most intense flares (such as class 3) produce strong Si XIV Lyman-α and often S XVI Lyman-α. Emission, in the form of Ka lines of highly ionized states of calcium, iron, aluminum, and silicon is usually present. The continuum from 1 to 10 angstroms always dominates the line emission by more than an order of magnitude. Electron temperatures derived from the slope of the continuum spectrum are in the range of 10
7
to 10
8
°K, considerably higher than theoretical ionization equilibrium temperatures.
Composition of Aqueous Solutions in Equilibrium with Sulfides and Oxides of Iron at 350°C
Authors: Raymahashay Bikash C. , Holland Heinrich D.
Published: October 2006

Solutions of potassium chloride (
p
H-buffered and 1-molal) equilibrated at 350°C with pyrrhotite, pyrite, and magnetite contained approximately 1 millimole of reduced sulfur and less than 0.1 millimole of oxidized sulfur per kilogram. Similar solutions equilibrated with pyrite, magnetite, and hematite contained approximately 1 millimole of reduced sulfur, but 3 to 6 millimoles of oxidized sulfur per kilogram. Both types of solutions contained less than 0.1 millimole of iron per kilogram at
p
H ≥ 6 and approximately 100 millimoles per kilogram at
p
H 2.
Erythropoiesis in the Rat: Differential Rates of DNA Synthesis and Cell Proliferation
Authors: Monette Francis C. , LoBue Joseph , Gordon Albert S. , Alexander Peter , Chan Po-Chuen
Published: October 2006

Direct in vivo estimates of DNA synthesis time in early and late erythroblasts were obtained by using the H
3
- and C
14
-thymidine double-labeling technique. A double-emulsion autoradiographic procedure was used to resolve the two isotopes. Early erythroblasts were found to proliferate at a rate about five times that of late cells. This results primarily from a shorter mean DNA synthesis time in early cells (2.5 hours) than in late cells (6.5 hours).
Dorsal Root Potentials and Ventral Root Reflexes Evoked by Nonmyelinated Fibers
Authors: Franz Donald N. , Iggo Ainsley
Published: October 2006

Electrical stimulation of C-fibers in the cat superficial peroneal nerve, with the A-fibers either conducting or blocked by cold, evoked dorsal root potentials having the same polarity as those evoked by A-fibers. Ventral root reflexes evoked by A-fibers were facilitated by a pure C-volley in the same or another nerve, but dorsal root potentials evoked by A-fibers were reduced by isolated dorsal root potentials from C-fibers. In the absence of anesthetics, single C-volleys produced brisk and prolonged reflex discharges in ventral roots.
Radiobiological Damage: A New Class Identified in Barley Seeds Stored after Irradiation
Authors: Conger B. V. , Nilan R. A. , Konzak C. F.
Published: October 2006

A new class of radiobiological damage has been identified in irradiated barley seeds. Consisting of both physiological and genetic damage, it appears to be independent of oxygen and long-lived free radicals, and develops very slowly during storage after irradiation. Increasing the storage temperature accelerates its development.
Hydrofoils: Optimum Lift-Off Speed for Sailboats
Authors: Baker Robert M. L.
Published: October 2006

For a hydrofoil sailboat there is a unique optimum lift-off speed. Before this speed is reached, if there are no parasitic vertical hydrofoil appendages, the submerged or partially submerged hydrofoils increase drag and degrade performance. As soon as this speed is reached and the hydrofoils are fully and promptly deployed, the performance of a hydrofoil-borne craft is significantly improved. At speeds exceeding optimum lift-off speed, partially submerged hydrofoils impair performance if there is no significant effect of loading on the hydrofoil lift-to-drag ratio.
Mice Unilaterally Sensitized for Audiogenic Seizures
Authors: Fuller John L. , Collins Robert L.
Published: October 2006

Strain SJL/J mice exposed to loud bell-ringing (primed) with one ear blocked do not convulse, but are susceptible to audiogenic seizures 48 hours later when stimulated only through the ear open at priming. Mice stimulated through the ear blocked at priming do not convulse, but are convulsible when retested on the opposite ear. The site of sensitization appears to be either in the ear or in those portions of the auditory system receiving input only from one side.
Operant Controlled Neural Event: Formal and Systematic Approach to Electrical Coding of Behavior in Brain
Authors: Fox Stephen S. , Rudell Alan P.
Published: October 2006

Traditional studies of electrophysiological correlates of behavior contain inherent high variability resulting from the arbitrary choice of behaviors, brain locations, and wave parameters. The operant control of neural events is a formal and systematic approach to the study of prespecified parameters and components of brain activity as they encode behaviors. Two studies in which the electrical activity of brain was the criterion for reinforcement demonstrate the acquisition, under such operant control, of two mutually exclusive behaviors or states which selectively alter evoked potential components.
Radar Scattering from Venus at Large Angles of Incidence and the Question of Polar Ice Caps
Authors: Jurgens R. F.
Published: October 2006

Spectrum analysis of radar waves backscattered from an anulus near the limb of Venus shows that a uniform scattering model applies over regions extending from the equator to within approximately 15 degrees of the poles. These observations indicate that large polar ice caps extending to latitudes as low as 60 degrees are very unlikely.
Photosynthesis: Temperate and Tropical Characteristics within a Single Grass Genus
Authors: Downton John , Berry Joseph , Tregunna E. Bruce
Published: October 2006

Leaves of two subgenera of
Panicum
differ in photosynthetic physiology and bundle sheath characteristics. Species of the subgenus Eupanicum, like other tropical grasses, had high phosphoenolpyruvate carboxylase (E.C. 4.1.1.31) activity, had specialized chloroplasts within the parenchyma bundle sheath cells, and lacked photorespiration. The pattern for the temperate subgenus Dichanthelium was opposite.
Lysozyme Retention by Cockroach
Periplaneta americana
L.
Authors: Wharton Denis R. A.
Published: October 2006

Blood from the cockroach
Periplaneta americana
usually does not react with a suspension of
Micrococcus lysodeikticus
. When lysozyme is added to the mixture it causes an immediate reduction in the optical density at 450 nanometers which is soon followed by a strong rise. Blood from roaches injected with lysozyme causes a similar series of changes in the optical density of a suspension of
M. lysodeikticus
, an indication that lysozyme has been retained in the blood. It may persist for many days or weeks.
6-Phosphogluconate Dehydrogenase: Hemizygous Manifestation in a Patient with Leukemia
Authors: Fialkow P. J. , Lisker R. , Detter J. , Giblett Eloise R. , Zavala C.
Published: October 2006

In a study of 41 patients with chronic myelocytic leukemia, two were found to have the 6-phosphogluconate dehydrogenase heterozygous phenotype A-B, and two had the phenotype characteristic of

Pd
B

homozygosity. Since one of the two with

Pd
B

homozygosity was the mother of two children with the A phenotype, it was presumed that she carried a

Pd
A

gene not expressed in her blood cells. This was confirmed by electrophoretic analysis of her fibroblasts, which had the A-B phenotypic pattern. Gene deletion is considered to be the most likely explanation.
Brown Adipose Cells: Spontaneous Mobilization of Endogenously Synthesized Lipid
Authors: Angel Aubie
Published: October 2006

Isolated brown adipose cells, devoid of a basement membrane, readily synthesized a variety of lipids from radioactive acetate, a reaction augmented by glucose and insulin. A large proportion of the newly formed fatty acids passed into the incubation medium. In intact brown adipose slices and isolated white adipose cells, most of the synthesized lipid was retained as glyceride esters. The data suggest that the rapid turnover of endogenously synthesized lipid in brown adipose cells is almost totally obscured in studies with intact tissue slices because of interstitial barriers to the egress of fatty acid.
Antigen-Associated Immunosuppressant: Effect of Serum on Immune Response
Authors: Whang H. Y. , Neter E.
Published: October 2006

Serum from various animal species, including the test animals themselves, inhibits the antibody response of the rabbit to two bacterial antigens, provided that antigen and immunosuppressant interact prior to injection. The degree of immunosuppression is related to the length of incubation in vitro of antigen and serum. Serum does not hinder or destroy the antigenic determinant. Bacterial antibodies do not account for inhibition of the antibody response. Antigen-associated serum components, as yet unidentified, may affect the early events of the immune response.
Adrenergic Blood Pressure Responses in the Shark
Authors: Schwartz Sorell L. , Borzelleca Joseph F.
Published: October 2006

Both nurse and lemon sharks recovered slowly from the pressor effect of epinephrine and from the depressor effect of isoproterenol. The recovery time increased with the dose of epinephrine. Grading of dosage and the use of dibenzyline revealed that these species exhibit alpha and beta adrenergic vascular responses in a manner qualitatively similar but quantitatively dissimilar to that for mammals.
Sodium Current in Ventricular Myocardial Fibers
Authors: Reuter Harald , Beeler George W.
Published: October 2006

Membrane currents were measured in thin bundles of dog ventricular myocardium under voltage-clamp conditions. A rather large initial inward current which had an equilibrium potential at about + 55 millivolts could be recorded. When the external sodium concentration was reduced, the equilibrium potential for this current was shifted by the amount predicted theoretically for a current carried solely by sodium ions. The size of the sodium inward current (
I
Na
) was largely dependent on the preceding membrane potential. The
I
Na
was completely inactivated if the membrane potential was as low as -45 millivolts. Sodium ions are the main carrier of charge during the rapid depolarization phase of the action potential.
Stimulus Generalization as a Function of Discrimination Learning with and without Errors
Authors: Lyons Joseph
Published: October 2006

After discrimination learning with and without errors, three groups of pigeons were tested for generalization to the angularity (negative stimulus) dimension. For half the subjects from each group, each angle was superimposed on a light of 555-nanometer wavelength, the positive stimulus during training; for the other half, the angles were on a black background. When tested to the angularity alone, the group which had made errors (pecked at the negative stimulus) during discrimination training showed a typical incremental (inverted) gradient of responding to the negative stimulus dimension. The control group and the one learning the discrimination without errors showed no differential control by the negative stimulus dimension. When each angle was superimposed on the positive stimulus during testing, a decremental gradient with maximum response strength to the negative stimulus was evidenced by the two groups learning with and the one group learning without errors.
Myxovirus Envelope Proteins: A Directing Influence on the Fatty Acids of Membrane Lipids
Authors: Tiffany John M. , Blough Herbert A.
Published: October 2006

Acyl chain compositions of the lipids of three strains of influenza virus show differences not anticipated from current theories of myxovirus assembly. Fatty acids of viruses with antigenically related envelope proteins show greater resemblance than those of an unrelated strain, which suggests that these proteins influence the composition of membrane lipids at the site of viral release.
Unique Envelope of a Jellyfish Ovum: The Armed Egg
Authors: Szollosi Daniel
Published: October 2006

The eggs of
Bougainvillia multitentaculata
are spawned with an envelope consisting of a single layer of cnidocvtes. The cnidocytes are surficial on eggs, cleavage stages, and young blastulae. During gastrulation, the cnidocytes are gradually incorporated into the ectoderm and become an integral part of the planula.
Condylactis
Toxin: Interaction with Nerve Membrane Ionic Conductances
Authors: Narahashi Toshio , Moore John W. , Shapiro Bert I.
Published: October 2006

A toxin from the Bermuda anemone
Condylactis gigantea
causes the early transient conductance change of crayfish giant axon membranes to persist without affecting the shape of its turning-on. The increase in late steady-state conductance is either not affected or slightly suppressed. The effect on the conductance components can adequately account for the prolonged action potential observed in the treated axon.
Cycasin: Detection of Associated Mutagenic Activity in vivo
Authors: Gabridge M. G. , Denunzio A. , Legator M. S.
Published: October 2006

Cycasin and its lagycone, methylazoxymethanol, increase the mutant frequency of
Salmonella typhimurium
histidine auxotrophs when tested in the host-mediated assay. As expected, the degree of cycasin-related mutagenic activity depends on the facility with which the compound can be enzymatically deglucosylated by the normal intestinal flora.
Evaporation Retarded by Monolayers
Authors: MacRitchie F.
Published: October 2006

The reduction in the steady-state rate of evaporation of water by hexadecanol monolayers depends only on the air velocity above the surface and is independent of the absolute rate of evaporation up to air velocities of 40 centimeters per second. This indicates that the monolayer does not affect the vaporization step but increases the size of the diffusion boundary layer. The mechanism (the creation of a surface pressure gradient in the monolayer which reduces the net stress on the surface by the air) is discussed.
Cytotoxic Effects of Leukocytes Triggered by Complement Bound to Target Cells
Authors: Perlmann Peter , Perlmann Hedvig , Müller-Eberhard Hans J. , Manni Jorge A.
Published: October 2006

Chromium-51-labeled chicken erythrocytes (E), treated with rabbit anti-Forssman antibody (A) and the first four (C1-4) or the first seven (C1-7) components of human complement (C), released isotope upon exposure to human leukocytes. Isotope release from EAC1-7 cells proceeded more rapidly and was more extensive than that from EAC1-3 cells. Lysis of these cells was suppressed by pretreatment of leukocytes with antimycin A. Monocyte-enriched leukocyte preparations affected both types of target cell-complement intermediates, whereas purified lymphocytes lysed EAC1-7 cells but not EAC1-3 cells.
Diffusive and Convective Flow Across Membranes: Irreversible Thermodynamic Approach
Authors: Bresler E. H. , Wendt Richard P.
Published: October 2006

The experimentally verified hydrodynamic approach to a description of diffusive and convective flow of solute across mutual membrane pathways is compared with the phenomenological equation resulting from the application of irreversible thermodynamics. Inherent nonlinearities in this equation severely, if not absolutely, limit its usefulness.
Spectral Reflectivity of Mars
Authors: McCord Thomas B. , Adams John B.
Published: October 2006

Analysis of data on the spectral reflectivity curves for both bright and dark areas of Mars disclosed several features not considered in previous models of the martian surface. The shape of the mean spectral geometric albedo curve between 0.3 and about 1.3 microns for Mars is defined to within a few percent. Spectral reflectivity curves based on relative reflectivity data were calculated for both a bright and a dark region between 0.4 and 1.1 microns. The curve for the dark region shows a broad, deep (∼13 percent) absorption feature centered near 1 micron. The curve for the dark area crosses that of the bright area between 0.4 and 0.5 micron during some martian seasons.
Venus Clouds: Test for Hydrocarbons
Authors: Plummer William T.
Published: October 2006

Infrared reflection spectra of hydrocarbon clouds and frosts now give a critical test of Velikovsky's prediction that Venus is surrounded by a dense envelope of hydrocarbon clouds and dusts. Venus does not exhibit an absorption feature near 2.4 microns, although such a feature is prominent in every hydrocarbon spectrum observed.
Triterpene Alcohol Isolation from Oil Shale
Authors: Albrecht P. , Ourisson G.
Published: October 2006

Isoarborinol, an intact pentacyclic unsaturated alcohol, was isolated from the Messel oil shale (about 50 × 10
6
years old). Complex organic substances, even those very sensitive to oxidation, reduction, or acidic conditions, can thus survive without alteration for long periods.
Bacterial Spores: Chemical Sensitization to Heat
Authors: Alderton Gordon , Snell Neva
Published: October 2006

Spore heat resistance is largely an inducible property, chemically reversible between a sensitive and resistant state. Therefore, the constitutive assumption and common practices based on it, such as direct testing of spores for heat resistance without prior treatment and the assumption of logarithmic death for spores in general, are no longer appropriate. A new approach is reported to the reduction of heating severity for a given survivor reduction of bacterial spores suspended in complex biological mixtures at their ordinary
p
H. Heating time advantages amount to severalfold and do not involve antimicrobial additives.
Optical Studies of Pulsar NP 0532
Authors: Duthie J. G. , Sturch C. , Richer H. B. , Rodney P.
Published: October 2006

The period of optical pulsations from NP 0532 has been determined to within 3 nanoseconds on three different nights. The time rate of change of the period

(dP/dt)
p

was 36.17 × 10
-9
second per day. The pulse shape was highly asymmetrical with strong indications of structure. The ratio of the amplitude of the main pulse to that of the interpulse varied with time. No evidence was found for photon coincidences in the pulse on a time scale shorter than 2 microseconds.
Planetary Probe: Origin of Atmosphere of Venus
Authors: Mueller Robert F.
Published: October 2006

The high temperatures and chemical composition, as determined by space probe and terrestrial observation, suggest that the present atmosphere of Venus has formed by chemical interaction with the lithosphere. Although the precise reactions have not been identified, good theoretical approximations to the molecular abundance may be obtained from reactions applicable to terrestrial rocks. The high temperatures and chemical reactivity create conditions on Venus which are fundamentally different from those on the cooler terrestrial planets where the attainment of equilibrium is prevented by kinetic barriers.
Two Unusual Unionid Hermaphrodites
Authors: van der Schalie Henry
Published: October 2006

In a survey of the gonads of 97 species of North American freshwater mussels representing 59 genera, only four species were found to be hermaphroditic (monoecious). Among several other "occasional" hermaphrodites, two were unique in that the same follicles in the gonads produced eggs and sperm simultaneously. Evidently the control mechanism failed to function normally in these species [
Actinonaias ellipsiformis
and
Villosa
(formerly
Micromya
)
iris
(Lea)]. This simultaneous production of eggs and sperm is apparently quite unusual among mollusks.
Insulin-Induced Augmentation of Lymphocyte-Mediated Cytotoxicity
Authors: Strom Terry B. , Bear Robert A. , Carpenter Charles B.
Published: October 2006

Physiologic concentrations of insulin enhance the ability of cytotoxic lymphocytes to injure target cells. The effect of insulin closely resembles the action of cholinomimetics and guanosine 3′,5′-monophosphate upon this system. Since both insulin and cholinomimetics elevate intracellular concentrations of guanosine 3′,5′-monophosphate, a common mode of action is suggested.
Podocarpus
from the Eocene of North America
Authors: Dilcher David L.
Published: October 2006

A few leafy gymnosperm shoots were found in Eocene deposits of southeastern North America. Similar fossil material from Tertiary deposits in North America has been identified as
Taxodium
,
Taxites
, and
Sequoia
. This new fossil material is not related to these genera but belongs to
Podocarpus
section
Stachycarpus
. This is the first fossil record of this section in North America.
Solar Radiation Profiles in Openings in Canopies of Aspen and Oak
Authors: Miller Philip C.
Published: October 2006

Vertical profiles of solar radiation in openings in forest canopies showed increasing solar radiation with depth in Colorado, but not in Minnesota. A model was developed and tested to calculate solar radiation in openings from the incoming direct and sky radiation and from the depth and diameter of the opening. The increase occurs only with high direct and low sky radiation. The model may explain the geographic and seasonal distribution of the solar radiation profiles and the lack of such observations previously.
Corchorus pascuorum
: Transmission of Chemically Induced Fruit Formation with Environmental Change
Authors: Islam A. S. , Mughal R.
Published: October 2006

When
Corchorus pascuorum
(Tiliaceae), native to Australia, was grown in the arid region of West Pakistan, it flowered abundantly but produced no fruit. It was induced to form fruit by treatment with 25 percent sucrose solution containing indolebutyric acid (300 parts per million). When plants were raised from the induced fruits, they fruited without any further treatment and retained the ability to produce fruits in two subsequent generations, whereas those raised from the original seeds produced no fruit.
Insect Metabolism of Photoaldrin and Photodieldrin
Authors: Khan M. A. Q. , Rosen Joseph D. , Sutherland Donald J.
Published: October 2006

Photoaldrin and photodieldrin, sunlight products of aldrin and dieldrin, are rapidly metabolized to a more toxic material by flies and mosquito larvae. It is suggested that this conversion is the cause for the enhanced toxicities of the photoproducts.
Multiplicity Reactivation as a Test for Recombination Function
Authors: Huskey Robert J.
Published: October 2006

Multiplicity reactivation of bacteriophage inactivated by ultraviolet light is dependent on the recombination function of either the host bacterial cell or the infecting bacteriophage. Absence of both recombination systems leads to a loss of multiplicity reactivation.
Potassium, Corticosterone, and Adrenocorticotropic Hormone Release in vitro
Authors: Kraicer Jacob , Milligan J. V. , Gosbee J. L. , Conrad R. G. , Branson C. M.
Published: October 2006

Incubation of rat adenohypophyses in a high concentration of potassium increases adrenocorticotropic hormone release. This increased release is suppressed by the addition of corticosterone to the incubating medium. Our findings are consistent with a process of "stimulus-secretion coupling" proposed for other glands and suggest that corticosterone may operate directly on the adenohypophysial cell membrane to inhibit releasing mechanisms.
Phycomyces
: Stimulus Storage in Light-Initiated Reactions
Authors: Ebrey Thomas G. , Clayton R. K.
Published: October 2006

The sporangiophores of
Phycomyces blakesleeanus
, a unicellular fungus, increase their growth rate temporarily when given a symmetric light pulse. When a sporangiophore is cooled until normal growth stops, the light pulse can still be perceived, and, after the sporangiophore is warmed to room temperature, the normal light-growth response is observed. Thus stimulus information can be "stored" at low temperatures in this sensory system.
Brood Care in Halictine Bees
Authors: Knerer G.
Published: October 2006

Four species of the halictine bee genus
Evylaeus
keep their brood cells open during most or part of the development of the larvae. In the colonial summer phase, house bees care for the young and keep brood cells clean from feces and exuviae. Progressive feeding of nector is present at least in
Evylaeus malachurus
, whose fully fed larvae are, on an average, 60 percent heavier than the egg-and-pollen stage. Interactions between the two generations of social Halictinae are of general occurrence, and their intensity corresponds to the level of social behavior attained.
DDT: Sublethal Effects on Brook Trout Nervous System
Authors: Anderson John M. , Peterson Margaret R.
Published: October 2006

When brook trout are exposed for 24 hours to sublethal doses of DDT, the cold-blocking temperature for a simple reflex, which shows lability related to thermal history, is altered in a way suggesting that DDT is affecting the thermal acclimation mechanism. Sublethal dosage of DDT also prevents the establishment of a visual conditioned avoidance response.
Stereoscopic and Resolution Acuity with Various Fields of View
Authors: Lura S. M.
Published: October 2006

Progressively restricting the field of view—without, however, obstructing the binocular visibility of the targets—does not affect resolution acuity, but stereoacuity is increasingly degraded.
Paleocene Hyracothere from Polecat Bench Formation, Wyoming
Authors: Jepsen Glenn L. , Woodburne Michael O.
Published: October 2006

A lower jaw of an eohippus (
Hyracotherium
cf.
H. angustidens
) from late Paleocene strata in Wyoming has extended the geological record of fossil horses into pre-Eocene time and suggests that the order Perissodactyla had an origin earlier than that heretofore conjectured. This specimen, together with equid teeth also possibly of late Paleocene age from Baja California, indicates that early perissodactyls were widespread on the North American continent before the Eocene epoch. Late Paleocene and early Eocene deposits of northwestern Wyoming have yielded many vertebrate rarities and "first or earliest occurrences" which require reappraisals of inter-and intracontinental dispersal patterns of the vertebrate groups involved.
Aluminum-Rich Apatite
Authors: Fisher D. Jerome , McConnell Duncan
Published: October 2006

More than 25 atomic percent of aluminum can substitute for other cations in the structure of apatite [
A
10
(
X
O
4
)
6
Z
2
]. Such a synthetic product was obtained by expelling volatile constituents (H
2
O and F) from morinite during thermal treatment. Infrared absorption spectra, chemical analysis, and x-ray powder diffraction demonstrate that the aluminum has two coordination numbers, and more than twice as much aluminum substitutes for calcium (
A
position) as for phosphorus (
X
position).
Aminoacyl Transfer Ribonucleic Acid Synthetases from Cell-Free Extract of
Plasmodium berghei
Authors: Ilan Judith , Ilan Joseph
Published: October 2006

Aminoacyl transfer ribonucleic acid synthetases for leucine, tyrosine, histidine, valine, proline, threonine, and lysine were obtained from cell-free extract of
Plasmodium berghei
. The leucyl-tRNA synthetase can charge tRNA from liver or
Escherichia coli
with leucine-C
14
, liver tRNA being a better substrate. The amount of aminoacylation increases linearly with respect to the quantity of tRNA added from either source and is dependent on the amount of enzyme added. The rate of aminoacylation is constant for 10 minutes and then decreases. It is enhanced by polyvinylsulfate. One-tenth millimolar pyrimethamine, hydroxystilbamidine, quinacrine, and acriflavine inhibited the formation of C
14
-valyl-tRNA. Species specificity between tRNA and its charging enzyme with respect to the recognition site is discussed.
Hallucinogen-Tranquilizer Interaction: Its Nature
Authors: Halasz Michael F. , Formanek Jaroslav , Marrazzi Amedeo S.
Published: October 2006

Study of the competition between hallucinogens and tranquilizers at cerebral synapses and on behavior in various species of animals indicates a continuum of effects from protection to dominance of tranquilizer toxicity as the dose of tranquilizer increases. Data on cat and monkey behavior, supplementing that on the rat, show that it is possible to arrive at a tranquilizer dose that can aggravate instead of protect, in accord with the competitive inhibitory nature of the interaction of hallucinogen and tranquilizer.
Encephalitogenic Protein: Structure
Authors: Kibler Robert F. , Shapira Raymond , McKneally Sarah , Jenkins Julia , Selden Pamela , Chou Frank
Published: October 2006

Amino acid sequences of encephalitogenic proteins from bovine cord and rabbit brain are reported. The bovine protein contains 45 residues. The rabbit protein is identical except for two isopolar substitutions, a dipeptide and amino acid deletion. Analysis of this protein and a 140-residue myelin basic protein indicates that the smaller protein is a portion of the larger encephalitogen. The larger myelin protein contains at least two encephalitogenic sites.
Plasma Saluretic Activity: Its Nature and Relation to Oxytocin Analogs
Authors: Sedláková E. , Lichardus B. , Cort J. H.
Published: October 2006

Plasma natriuretic activity was evoked in cows and dogs by infusion of saline with or without dextran. Deproteinized samples were fractionated on both Sephadex and Bio-Gel columns; the activity was separated, the approximate molecular weight being in the region of 1000. Incubation with chymotrypsin destroyed the activity, suggesting that it might be a polypeptide. A similar activity in blood resulted from intracarotid injection of either oxytocin or either of two synthetic analogs. Possibly the latter are saluretic by virtue of a releasing action on some intracranial structure for another natriuretic peptide.
Interhemispheric Transport of Atmospheric Fission Debris from French Nuclear Tests
Authors: Palmer B. D.
Published: October 2006

Radioactive iodine-131 (half-life, 8.06 days) and barium-140 (half-life, 12.8 days), released into the atmosphere (21°S, 137°W) by the French nuclear tests conducted during the period 24 August to 8 September 1968, have been observed in rainfall at Arkadelphia, Arkansas (34°N, 94°W). The maximum time required for the transport of the debris from a mid-southern to a mid-northern latitude appears to be about 3 weeks.
Herpesvirus in Marek's Disease Tumors
Authors: Schidlovsky G. , Ahmed M. , Jensen K. E.
Published: October 2006

Intranuclear and cytoplasmic virus particles of the herpes type were located in epithelial cells that line the kidney collecting tubules obtained from a chick with Marek's disease. The chick had contracted the disease by direct contact transmission. The virus was not observed in any of the invading tumor cells in the same kidney.
Auditory Habituation and Barbiturate-Induced Neural Activity
Authors: Webster W. R.
Published: October 2006

The finding that barbiturates abolish habituation decrements in auditory evoked potentials has been interpreted as being caused by removal of the influence of the reticular formation. Similar changes in the medial geniculate are produced by barbiturates without any intervening habituation, suggesting that refractory processes have been confused with habituation.
Venus: An Isothermal Lower Atmosphere?
Authors: Gale W. , Liwshitz M. , Sinclair A. C. E.
Published: October 2006

Use of Earth-based microwave data in extrapolating the atmospheric profile of Venus below the region probed by Mariner V and Venera 4 reveals an isothermal layer at 670° ± 20°K that extends to an altitude of 7 ± 2 kilometers. This model gives a value of 6054.8 kilometers for the radius of Venus, and agreement with brightness spectrum, radar cross sections, and results of microwave interferometry.
Nucleoside Triphosphate Termini from RNA Synthesized in vivo by
Escherichia coli
Authors: Jorgensen Sally E. , Buch Loraine B. , Nierlich Donald P.
Published: October 2006

Alkaline hydrolyzates of RNA made in vivo by
Escherichia coli
contain ribonucleoside-3′-monophosphate-5′-triphosphates. These probably arise by hydrolysis of the initial nucleoside triphosphate from the 5′ terminus of the nascent RNA chains. Logarithmically growing cultures, labeled for 45 seconds with
32
P-labeled phosphate, yield about 2000 molecules of labeled tetraphosphate per cell, this yield increasing only slightly with continued labeling. Only the tetraphosphates of adenosine and guanosine have been found in
Escherichia coli
, and these two are present in approximately equal amounts.
Stability of Asymmetric Phospholipid Membranes
Authors: Papahadjopoulos Demetrios , Ohki Shinpei
Published: October 2006

Bilayers (black films) composed of phosphatidylserine are unstable under conditions of asymmetric distribution of calcium or hydrogen ions with respect to the membrane. Addition of calcium ions to the solution (100 millimolar sodium chloride,
p
H 7.0) on one side only, produces lowering of the direct-current resistance and results in breaking of the membrane. However, with calcium ions on both sides the membranes are stable and show very high electrical resistance.
Automatic Determination of Crystal Structure
Authors: Johnson Quintin , Smith Gordon S. , Kahara Eileen
Published: October 2006

Several crystallographic computer programs have been organized into one large automatic program for solving crystal structures. The emphasis of this organization has been to produce a noninteractive system, that is, to have all decisions made by the computer. Input data are the raw intensity data, cell constants, space group, chemical formula, and other miscellaneous items. The output is a stereo picture of the contents in a unit cell. The program, operating in a noninteractive mode, has successfully solved compounds of unknown structure; in addition, for a test compound of completely unknown composition, this program deduced the correct structure with an average error in bond distance of 0.05 angstrom and an average error in bond angle of 7°.
Calcium Uptake by Isolated Sarcoplasmic Reticulum Treated with Dithiothreitol
Authors: Van der Kloot William
Published: October 2006

Isolated vesicles of the sarcoplasmic reticulum are known to take up calcium when provided with magnesium adenosine triphosphate as an energy source. Preparations of high activity are obtained by keeping the vesicles in 5 millimolar dithiothreitol (a reagent that reduces disulfide groups), and these preparations retain activity for a week or longer. The highly active preparations lend themselves to a spectrophotometric method for following calcium uptake, and continuous uptake kinetics are readily obtained. Calcium uptake appears to follow Michaelis-Menten kinetics (
K
m
= 8 × 10
-6
;
V
max
= 7 × 10
-7
mole per second per milligram of protein). These preparations are also useful for studying the effects of inhibitors of uptake, such as quinine. When extrapolated to the intact muscle, the results from these isolated vesicles should give a better estimate than has been available of the actual rates of calcium uptake and of the physiological effect of inhibitors of uptake.
Dark Adaptation: An Interocular Light-Adaptation Effect
Authors: Lansford Theron G. , Baker Howard D.
Published: October 2006

Presentation of light to the left eye simultaneously with adaptation of the right eye to light may accelerate dark adaptation in the right eye. The result is that the rod-cone-break and the final threshold of the rods are achieved earlier than when the right eye alone is adapted to light.
Immunoglobulins G, A, and M Determined in Single Cells from Human Tonsil
Authors: Gitlin David , Sasaki Teruo
Published: October 2006

The analysis of specific proteins in single cells is described and applied to the determination of immunoglobulins G, A, and M (γG, γA, and γM) in lymphoid cells of the human tonsil. The number of cells containing γA or γM was much less than the number of cells containing γG, but the average cell content of γA or γM was much greater than the average cell content of γG. Similarly, in one child where relatively few cells containing γG were found, the average cell content of γG in those cells was higher than that in the other children. The limit of sensitivity of the method for each of the three immunoglobulins with the antiserums used was less than 10
-14
gram of the specific protein.
Blood-Brain Barrier: Evidence for Active Cation Transport between Blood and the Extracellular Fluid of Brain
Authors: Bito Laszlo Z.
Published: October 2006

The concentration gradients of Mg
++
and K
+
in the cerebrospinal fluid system indicate that the (Mg
++
) is higher and the (K
+
) is lower in the extracellular fluid of the cerebral cortex than the concentrations of these cations in either plasma-dialysate or cisternal fluid. Such cation distribution demonstrates the existence of an active transport process across the blood-brain barrier.
Cooling History of Orthopyroxenes
Authors: Hafner Stefan S. , Virgo David
Published: October 2006

Order-disorder transitions between ferrous iron and magnesium in orthopyroxenes [minerals close to the composition (Fe,Mg)SiO
3
] occur rapidly between approximately 480° and 1000°C. Disordering and ordering have been studied experimentally. The determination of the metastable ferrous iron site occupancy in orthopyroxenes from rapidly cooled volcanic rocks provides information on the cooling rates, especially from 600° to 480°C.
Photoperiod in Three
Xanthium
Populations from the Tropic of Cancer in Mexico
Authors: McMillan Calvin
Published: October 2006

Diverse photoperiodic responses were shown by three populations of
Xanthium strumarium
L. originating between 22° and 25°N on the western coast near Culiacán, Sinaloa; in the Chihuahuan Desert near Matehuala, San Luis Potośi; and on the Gulf Coast near Ciudad Mante, Tamaulipas, respectively. A combination of differences in critical night length and in ripeness-to-flower response (maturity) appears to be the basis for reproductive adaptation of these populations to different climatic regimes that prevail at the same latitude (and photoperiodic regime).
Cell Wall Protein in Plants: Autoradiographic Evidence
Authors: Sadava D. , Chrispeels Maarten J.
Published: October 2006

Autoradiography of phloem-parenchyma tissue from carrots, which was allowed to incorporate radioactive proline and then plasmolyzed, indicates that a stable protein moiety is associated with the cell wall.
Field Potentials Generated by Dendritic Spikes and Synaptic Potentials
Authors: Zucker Robert S.
Published: October 2006

Predictions from the cable model and equations for field potentials generated by single neurons are computed and compared with extracellular recordings from synaptically activated cerebellar Purkinje cell dendrites. Neither theory predicts the results, nor does the experimental situation satisfy the assumptions of either theory. Theoretical calculations from a recent formulation developed by Rall compare favorably with potentials recorded by other authors. Applications of these formulations are discussed.
Antigen Combining Activity Associated with Immunoglobulin D
Authors: Gleich Gerald J. , Bieger R. Cyril , Stankievic Raisa
Published: October 2006

The titers of antibodies to the benzylpenicilloyl antigenic determinant are increased with specific antiserum to immunoglobulin D, as shown by the enhancement method. This increase in titer is blocked by purified immunoglobulin D protein but not by immunoglobulins of the other four classes.
Epinephrine Metabolism in Mammalian Brain after Intravenous and Intraventricular Administration
Authors: Steinman Alan M. , Smerin Stanley E. , Barchas Jack D.
Published: October 2006

Epinephrine given intravenously or intraventricularly has a half-life in the brain of the rat of 2 to 2.5 hours. After intravenous administration of the drug the principal route of metabolism is
O
-methylation, whereas after intraventricular administration the principal route is conjugation.
Acidic Components of Green River Shale Identified by a Gas Chromatography-Mass Spectrometry-Computer System
Authors: Murphy Robert C. , Djuricic Milica V. , Markey Sanford P. , Biemann K.
Published: October 2006

A system consisting of a gas chromatograph coupled to a mass spectrometer and computer has been used to characterize the extractable acidic components of Green River shale. This system accumulates mass spectra at every point of the gas chromatogram in a permanent form which permits one to observe mass spectra of minor as well as major constituents. One minor component, whose identification was confirmed by synthesis, was 6,10,14-trimethylpentadecanoic acid.
Atherosclerotic Plaque: X-ray Diffraction Investigation
Authors: Spector M. , Krokosky E. M. , Sax M. , Pletcher J.
Published: October 2006

Human atherosclerotic plaque material continuously maintained in an aqueous environment has been subjected to examination by x-ray diffraction. The first diffraction pattern from single crystals of human biological apatite was obtained from the plaque material of a freshly excised plaque when it was equilibrated with its aqueous environment. As the plaque material dried, the discrete spots characteristic of single crystal diffraction disappeared, leaving only the powder pattern of apatite.
Viral Infection Across Species Barriers: Reversible Alteration of Murine Sarcoma Virus for Growth in Cat Cells
Authors: Fischinger Peter J. , O'Connor Timothy E.
Published: October 2006

Infection of cat embryo cells by a centrifugally induced aggregate of murine sarcoma virus and feline leukemia virus gave rise to a defective, focus-forming virus which propagated in cat cells, but not in mouse cells. This virus, apparently enveloped with a feline leukemia virus coat, was later subjected to aggregation with murine leukemia virus, whereupon it regained the capacity for growth in mouse cells.
Separation of Type 2 Toxins of
Vibrio cholerae
Authors: Lewis A. Carter , Freeman Bob A.
Published: October 2006

Choleragenic toxin was separated from vascular permeability factor by ion-exchange chromatography of supernatants of dialyzed peptone cultures of
Vibrio cholerae
. The choleragenic toxin eluted from columns of QAE-Sephadex with low-ionicity systems is free of permeability factor activity. Further elution of these columns with 0.5
M
NaCl removes both the permeability factor and residual choleragenic toxin. When this latter material is chromatographed on columns of carboxymethyl-Sephadex, the permeability factor toxin is eluted by 0.02
M
phosphate buffer and is free of choleragenic activity. Therefore, choleragenic and permeability factor activities of the type 2 cholera toxins are different and can be separated by these procedures.