bluuebunny/crossref_metadata_2025 huggingface dataset:
Measurement of Precipitin Reactions in the Millimicrogram Protein-Nitrogen Range
Authors: Glick David , Good Robert A. , Greenberg Leonard J. , EDDY JENNIFER J. , DAY NOORBIBI K.
Published: October 2006

Exploitation of newer instrumentation and a dye-binding method for protein measurement made possible reduction in volume down to 1/1000 that commonly used, with no greater error. The procedure was tested at two levels, 1- and 10-μl volumes, with human gamma globulin and rabbit antiserum. Of the dyes tested, bromsulfalein proved best for the protein estimation.
Crossbridge Attachment, Resistance to Stretch, and Viscoelasticity in Resting Mammalian Smooth Muscle
Authors: Siegman Marion J. , Butler Thomas M. , Mooers Susan U. , Davies Robert E.
Published: October 2006

There exists a calcium-dependent resistance to stretch in resting mammalian smooth muscle that is not caused by depolarization of the cell membrane or release of calcium from intracellular sites. The similarity of the resistance to stretch in the resting state to that in rigor suggests that most, if not all, crossbridges are attached and thus able to resist stretch in noncontracting smooth muscles. When the muscle is stretched the breaking and subsequent reformation of links in nonstrained positions accounts for most of the so-called viscoelasticity, except at extreme lengths.
Possible Relation between Marine Fungi and
Limnoria
Attack on Submerged Wood
Authors: Ray D. L. , Stuntz D. E.
Published: October 2006

Wood submerged in the sea at Friday Harbor and at Naples contained only occasional hyphae, which showed no relationship to
Limnoria
burrows. Cultures of
Limnoria
established in "unconditioned" wood and in autoclaved wood were maintained in the absence of fungi. These results indicate that marine fungi have no significance for the activities of
Limnoria.
Mutation in the Protozoan
Paramecium multimicronucleatum
as a Result of X-irradiation
Authors: Wichterman Ralph
Published: October 2006

Mutations have been produced in the protozoan
Paramecium multimicronucleatum
by repeatedly exposing clonal cultures of the animals to large dosages of x-irradiation. The descendants of x-rayed survivors showed the following changes, which persisted in culture: destruction and loss of all micronuclei, decrease in vitality and reproductive rate, increase in x-radiation sensitivity, monstrosity, and reduced body size.
Enhancement by Inositol of the Nodulation of Isolated Bean Roots
Authors: Raggio Nora , Raggio Miguel , Burris R. H.
Published: October 2006

The percentage of isolated bean roots nodulated and the number of nodules per root were increased by the addition of mesoinositol to the agar medium into which the bases of bean roots were inserted. The following were without marked effect: glycine, thiamine, pyrodoxine, niacin, indoleacetic acid, gibberellic acid, kinetin, adenine, adenosinetriphosphate, biotin, riboflavin, calcium pantothenate, and folic acid.
Functional Hermaphroditism and Self-fertilization in a Serranid Fish
Authors: Clark Eugenie
Published: October 2006

Each mature individual of
Serranellus subligarius
, regardless of size, has at the same time both motile sperm and eggs. Embryos and larvae were produced from artificial fertilizations and from isolated fish kept in aquaria. Mating behavior of pairs and groups of hermaphrodites shows two types of behavioral patterns involving different color changes.
Maximum Permissible Body Burden of Strontium-90
Authors: Björnerstedt R. , Engström A.
Published: October 2006

The permissible body burden of Sr
90
is discussed with respect to the mode of intake. It appears that the maximum permissible load may depend on the type of exposure, acute or chronic, the acute being the more serious.
Partial Chromatographic Separation of Pentose- and Deoxypentosenucleic Acids
Authors: Main R. K. , Wilkins Marjorie J. , Cole L. J.
Published: October 2006

From a mixture of tobacco mosaic virus pentosenucleic acid (RNA) and calf thymus deoxypentosenucleic acid (DNA) (2 mg each), 73 percent of the RNA was separated free of DNA by discontinuous elution chromatography with phosphate buffers at
p
H 6.7 on columns of calcium phosphate.
Shape of the Nucleus
Authors: Wilets Lawrence
Published: October 2006

The gross features of nuclear morphology can be summarized as follows. Nuclei have shapes similar to a diffuse-surfaced, liquid drop. The interior density is rather uniform, and also constant from nucleus to nucleus. The constancy of nuclear density implies an A
1/3
law for the mean nuclear radius, the proportionality constant being 1.07 × 10
–13
centimeter. The surface region is diffuse, the nuclear density falling from 90 to 10 percent of the central value in a distance of about 2.4 × 10
–13
centimeter, independently of nuclear mass number.

Nuclear shapes can vary rather widely, with doubly magic nuclei preferring spherical symmetry. Some nuclei execute volume-preserving oscillations about spherical shape, while others possess permanent spheroidal deformations. The values of the deformation parameter, ε, for such spheroids possibly attains 0.85 for some light nuclei and 0.4 for some intermediate weight nuclei.

There is some evidence, based on the occurrence of "inversion" spectra and asymmetrical fission, that pear-shaped nuclei may also exist.
Synchronized Cell Division and DNA Synthesis in a
Lactobacillus acidophilus
Mutant
Authors: Burns Victor W.
Published: October 2006

Withdrawal and subsequent restoration of deoxyriboside to a deoxyriboside-requiring mutant leads to synchronous cell division. There is a time lag between restoration and the first synchronous division; during this time the amount of deoxyribonucleic acid (DNA) per cell increases in stepwise fashion, and mass per cell increases linearly with time. The onset of cell division is heralded by cessation of DNA synthesis and an abrupt increase in rate of mass synthesis.
Cholecystokinin Activity of Urine
Authors: Svatos Antonin
Published: October 2006

In the urine of men and animals was found a factor which evokes the contraction of the gall bladder. This factor increases in the urine after the application of a secretogenous stimulus to the duodenum and decreases after resection of the duodenum. A urine concentrate was prepared which has an effect similar to that of cholecystokinin administered intravenously and which was therefore called urocholecystokinin.
Comparison of the Effects of Delayed Auditory Feedback on Speech and Key Tapping
Authors: Chase Richard Allen , Harvey Seth , Standfast Susan , Rapin Isabelle , Sutton Samuel
Published: October 2006

Delaying the return of a speaker's vocal output to his ears (the auditory feedback) radically changes his speech. The present report concerns the effect of delayed auditory feedback on simple key-tapping tasks. Evidence is presented which indicates that changes in speech and key tapping under delayed auditory feedback are analogous.
Interference with Feedback Control: a Mechanism of Antimetabolite Action
Authors: Moyed H. S. , Friedman Mildred
Published: October 2006

The action of an enzyme essential for tryptophan biosynthesis is inhibited by tryptophan and also by an analog of tryptophan. Similarly, histidine and one of its analogs inhibit the action of an enzyme essential for histidine biosynthesis. A mutant resistant to the histidine analog produces an apparently altered enzyme which is insensitive to both the analog and histidine.
Learning in Rats with Extensive Neocortical Damage
Authors: Thompson Robert
Published: October 2006

Albino rats with as much as 99 percent damage to the cerebral cortex were trained on a position habit in a simple
T
-maze. The operated rats were found to learn the problem as efficiently as normal animals even when a 30-second delay was imposed between the response and the food.
Free β-Hydroxy-γ-amino-butyric Acid in Brain
Authors: Ohara Kazuo , Sano Isamu , Koizumi Hideo , Nishinuma Keiji
Published: October 2006

By using the methods of paper chromatography and high-potential paper electrophoresis and by comparing the pattern of prepared extracts with that of synthesized β-hydroxy-γ-aminobutyric acid, we found that free β-hydroxy-γ-aminobutyric acid exists in the brains of mice, rabbits, cattle, and human beings.
High-Energy Phosphates during Long-Term Hibernation
Authors: Zimny Marilyn L. , Gregory Roy
Published: October 2006

Adenosine triphosphate (ATP) and phosphocreatine (PC) show contrasting levels in muscle and liver after short and long periods of hibernation. In prolonged hibernation cardiac and skeletal muscle PC continues to maintain ATP, but at lower levels. In the liver, control levels for these compounds are regained.
Factors Influencing the Effect of β-Propiolactone on Chromosomes of
Vicia faba
Authors: Swanson Carl P. , Merz Timothy
Published: October 2006

The effect of β-propiolactone on chromosomes is independent of
p
H, oxygen tension, and some metabolic inhibitors. It is influenced by temperature, concentration, and pretreatments with dinitrophenol. Interphase sensitivity and localization of breaks are discussed in terms of the action of β-propiolactone and the relationship of β -propiolactone to other radiomimetic compounds.
Spiral Capillary Plastic Scintillation Flow Counter for Beta Assay
Authors: Funt B. L. , Hetherington A.
Published: October 2006

Tracer counting of beta emitters in aqueous solution was performed with a detector fabricated from a plastic scintillator capillary. The detector exhibits low gamma background and reproducible detection efficiency, and it requires minimum sample preparation. Counting efficiencies were determined for aqueous solutions of P
32
, Na
22
, and C
14
and for C
14
O
2
gas.
Sex Peptide of
Drosophila melanogaster
Authors: Fox Allen S. , Mead Charles G. , Munyon Ilse L.
Published: October 2006

All tested stocks of
Drosophila melanogaster
exhibit a peptide in males but not in females. The failure of some investigators to demonstrate its presence is attributable to their choice of chromatographic solvents. Acid hydrolysis confirms its peptide identity. Its presence in females transformed into males by the mutant
tra
implicates the sex-determining loci in its formation.
Identification and Assay of 5-Hydroxytryptamine in Molluscan Tissues by Fluorescence Method
Authors: Welsh John H. , Moorhead Merilyn
Published: October 2006

The fluorescence assay method has been used in the identification and quantitative estimation of 5-hydroxytryptamine (5-HT) in mollusks. Ganglia of a representative pelecypod contain more 5-HT than those of a gastropod. Most non-nerve tissues have low levels of 5-HT, which, except in "kidneys," may derive from nerve endings.
Relationship of 3α-Hydroxysteroid Dehydrogenase to Pyridine Nucleotide Transhydrogenases
Authors: Stein Abraham M. , Kaplan Nathan O.
Published: October 2006

It appears that the α-hydroxysteroid dehydrogenases are not significant entities in promoting transhydrogenase reactions in animal tissues.
Antidromic Cortical Response to Stimulation of Isolated Pyramidal Tract
Authors: Towe A. L. , Jabbur S. J.
Published: October 2006

Direct electrical excitation of the intact medullary pyramids evokes a complex cortical response. When the pyramidal tract was dissected away from the bulb and stimulated in isolation, the antidromic cortical response consisted of a simple, positive potential, regardless of the stimulus parameters. This finding necessitates a reinterpretation of previous results obtained by stimulation of the intact pyramids.
Lactation Hair in the Asiatic Squirrel and Relationship of Lactation Hair to Mammary Hair
Authors: Landry Stuart O.
Published: October 2006

A hair growth around the nipples during lactation is described in two species of the Asiatic squirrel genus
Callosciurus.
The term
lactation hair
is coined for this phenomenon, which is shown to be different from
mammary hair
in the sense for which that term was coined.
Occurrence of High Ozone Concentrations in the Air near Metropolitan Washington
Authors: Wanta R. C. , Heggestad Howard E.
Published: October 2006

Relatively high concentrations of surface ozone and the indication that ozone is the inciting agent in fleck injury to tobacco were reported previously. Considerable interest therefore attaches to weather parameters on the high-ozone days which may throw light on the source and on the physicochemical processes affecting the ozone level. A source in the direction of nearby Washington, D.C., and photochemical production of the oxidant are indicated. Days with appropriate wind direction but low peak ozone concentration are discussed in terms of coexisting weather parameters. The weather ensemble found on high-ozone days is considered in relation to instances of fleck injury for which peak ozone levels were not measured.
Display of Moving Parts of a Scene
Authors: Mackay R. Stuart
Published: October 2006

Methods for emphasizing the moving parts of a scene. By photographic or electronic means, a past image can be subtracted from the present one to emphasize the moving parts of a motion picture scene. Rhythms and patterns of motion become more noticeable, and changes in velocity can give an impression of accelerations and the force pattern.
Effect of the Solar Wind on the Lunar Atmosphere
Authors: Herring J. R. , Licht A. L.
Published: October 2006

The extent of the lunar atmosphere is severely limited by collision with the protons of the solar wind.
Generalization from Pain of Various Types and Diverse Origins
Authors: Beecher Henry K.
Published: October 2006

Pain that arises from very different pathological origins responds in a quantitative fashion to a given dose of a given narcotic, but this is not true when the pain has been contrived by experimental means, in man, with customary techniques.
Inhibition of O-Methyltransferase by Catechol and Sensitization to Epinephrine
Authors: Bacq Zenon M. , Gosselin Luc , Dresse Albert , Renson Jean
Published: October 2006

Catechol at equimolecular concentration inhibits the inactivation of adrenaline by O-methyltransferase in vitro about 50 percent. The inhibition is probably responsible for the sensitization of smooth muscles to epinephrine by various ortho di- or triphenols.
Self-Regulation of Brain-Stimulating Current Intensity in the Rat
Authors: Stein Larry , Ray Oakley S.
Published: October 2006

A modification of the self-stimulation technique of Olds enabled rats to regulate and maintain at a preferred level the amount of brain-stimulating current they received as reinforcement for lever pressing. The method used two levers to deliver brief brain shocks: each response at one lever increased the current intensity a small step and each response at the other lowered it one step.
Individuality of the Meromyosins
Authors: Middlebrook W. R.
Published: October 2006

Subtilisin, as well as trypsin and chymotrypsin, splits myosin into meromyosin-like components. Examination of the N- and C-terminal residues of the L-meromyosin-like products suggests that all three proteases produce identical L-meromyosins. It is proposed that the role of the enzymes is to break secondary bonds.
Specific Action of Adenine as a Feedback Inhibitor of Purine Biosynthesis
Authors: Gots Joseph S. , Goldstein Jacob
Published: October 2006

Purines can prevent the formation of aminoimidazole precursors which are accumulated by bacterial mutants genetically blocked in purine biosynthesis. If the block does not interfere with interconversions among adenine, guanine, hypoxanthine and xanthine, then any of the purines can act as a feedback inhibitor. If conversion of the other purines to adenine is prevented, then adenine becomes a specific requirement for inhibition; this indicates that feedback control operates at a level involving adenine or one of its congeners.
Effect of Light on Motility, Life-Span, and Respiration of Bovine Spermatozoa
Authors: Norman Charles , Goldberg Erwin
Published: October 2006

Exposure to light of bovine spermatozoa suspended in various media results in a progressive decline in metabolic activity followed by the premature death of the cells. The inhibitory and spermicidal effects of visible light resemble a photodynamic action; the photosensitizer is an intrinsic component of the cell.
Sensory Deprivation and Visual Speed: An Analysis
Authors: Held Richard , White Burton
Published: October 2006

Speeds of moving objects were markedly underestimated by human observers after prolonged patternless visual stimulation. Even greater underestimation followed exposure to a "noisy" visual field; on the other hand, exposure to a hyperstable field caused overestimation. The effects of external visual noise simulate those of deprivation; this finding suggests that similarly disordered but spontaneous neural discharge dominates the visual nervous system in deprivation.
Effect of Dietary Fats on Fatty Acid Composition of Human Erythrocytes and Chick Cerebella
Authors: Horwitt Max K. , Harvey Cecil C. , Century Bernard
Published: October 2006

Through gas-liquid chromatography it can be shown that increasing the ingestion of linoleic acid-containing fats increases the deposition of linoleic acid in erythrocytes and in brain tissue. Such changes are probably causally related to the tocopherol requirement, the incidence of chick encephalomalacia, and the peroxide hemolysis test. Whether similar mechanisms are involved in the ability of unsaturated oils to lower serum cholesterol levels remains to be determined.
Respiratory Carbon Dioxide Response Curve Computer
Authors: Bellville J. Weldon , Seed J. C.
Published: October 2006

The respiratory computer described here makes it possible to obtain more accurate and precise alveolar ventilation-
P

CO
2

response curves than formerly and with fewer man-hours of labor. It is hoped that the ease of obtaining these response curves will lead to their more frequent use in evaluating respiratory phenomena. Clinical applications in evaluating the effects of changes in compliance and airway resistance on respiration are readily apparent. This technique is being used to study the degree of respiratory depression caused by narcotics and anesthetics and to study the effects of stimulating drugs. Respiratory stimulation and depression in a variety of disease states are also being pursued.
On Pleistocene Surface Temperatures of the North Atlantic and Arctic Oceans
Authors: Ewing Maurice , Donn William L.
Published: October 2006

Two additional interpretations are given for the important data of D. B. Ericson on the correlation of coiling directions of
Globigerina pachyderma
in late Pleistocene North Atlantic sediments with ocean surface temperatures. One interpretation relates the distribution of this species to the distribution and circulation of ocean water masses. On the basis of our ice-age theory, our second interpretation uses the data and correlations of Ericson to establish temperature limits of a thermal node, a line on which glacial and interglacial temperatures were equal, for the North Atlantic Ocean. This line crosses the strait between Greenland and Scandinavia. Further, Ericson's interpretation of the 7.2°C isotherm implies that the glacial-stage surface waters of the Arctic Ocean were between 0° and 3.5°C.
Inhibition of Central Auditory Response
Authors: Ruben Robert J. , Sekula Jan
Published: October 2006

Suitable electrical stimulation of the region of the decussation of the olivocochlear bundles, which supply efferent innervation to the organ of Corti, was found to abolish the response of the auditory cortex to a click, without changing the responses (N
1
and N
2
) of the eighth nerve in cats. At higher stimulation values the eighth nerve responses also were abolished, and at intermediate stimulus values responses at the medial geniculate and inferior colliculus were suppressed.
Geomagnetic Rotational Retardation of Satellite 1959α1 (Vanguard II)
Authors: Wilson Raymond H.
Published: October 2006

Radio observations made during the battery life of Vanguard II showed that the satellite's rotation was being retarded exponentially at a rapid rate. Precise analysis of electromagnetic couples on the conducting and magnetic parts of the satellite indicates a mean ambient geomagnetic field of 0.158 gauss, and confirms the eddy-current theory previously applied to Vanguard I.
Induction of Ovulation in Immature Hypophysectomized Rats
Authors: Velardo Joseph Thomas
Published: October 2006

Immature rats given minute doses of highly purified pituitary gonadotropins (follicle-stimulating hormone and luteinizing hormone) 7 to 100 days after hypophysectomy ovulated and formed corpora lutea. Neither hormone alone was effective. Luteinizing hormone repaired in part the atrophied theca interna and interstitial tissue, and follicle-stimulating hormone stimulated the development of the granulosa cells.
Geochemistry of Graywackes and Shales
Authors: Weber Jon N.
Published: October 2006

Sixty-nine graywackes and 33 shales were analyzed spectrographically for 14 minor elements to illustrate the variation of composition within a graywacke bed, between beds in one section, between sections, and between formations. Analyses of several fractions of a graywacke indicate what each contributes chemically to the rock.
Sexual Dimorphism of Rat Cells in vitro
Authors: Miles Charles P. , Koons Audrey S.
Published: October 2006

Large peripheral chromocenters occurred in about 10 percent of the nuclei of female rat cells grown in vitro but occurred on the average in less than 1 percent of the nuclei of male cells. Similar chromocenters occurred in hamster and mouse nuclei in vitro, but no clear-cut sexual difference was demonstrable.
Sexuality and Mating in
Salmonella
Authors: Zinder Norton D.
Published: October 2006

Another criterion for the presence of the agent (F) promoting genetic exchange in
Escherichia coli
was found. It involves a staining reaction of Hfr and F+ coli, but not F- coli, when mixed with strains of
Salmonella typhimurium
. This reaction was used as a guide in following the transfer of the F agent to
Salmonella
and back to
E. coli
. The F agent in
Salmonella
seems to promote the same kinds of events that it promotes in
E. coli
.
Isolation from Animals of Human Strains of Staphylococci during an Epidemic in a Veterinary School
Authors: Pagano Joseph S. , Farrer Sanford M. , Plotkin Stanley A. , Brachman Philip S. , Fekety F. Robert , Pidcoe Vern
Published: October 2006

Antibiotic-resistant staphylococci of the same bacteriophage type were isolated from the external nares of asymptomatic domestic animals and from human beings during an epidemic of staphylococcal disease in veterinary students. Not all of the infections could be attributed to person-to-person contact; spread could be explained also by transmission of staphylococci from animals.
Virus Production by Subcultured Monkey-Kidney Cells
Authors: Lieberman Irving , Youngner J. S. , Ove Peter
Published: October 2006

Cultured monkey-kidney cells, like the rabbit cells previously studied, have a relatively high folic acid requirement for growth. Subcultures can be readily prepared if the medium is supplemented with a high level of the vitamin. The sensitivity of the resultant cells to poliovirus and the yields of virus obtainable with them are the same as with primary cultures.
Significance of the Presence of Exchangeable Magnesium Ions in Acidified Clays
Authors: Barshad I.
Published: October 2006

Magnesium ions (Mg
++
) were shown to constitute a substantial percentage of the total exchangeable cations in acidified clay samples from various sources. This finding helps in solving several problems of long standing in the fields of soil chemistry, soil formation, and geochemical weathering.
Mean Lifetime of Free Radical Chains Determined by a Flow Technique
Authors: McIntosh R. G. , Eager R. L. , Spinks J. W. T.
Published: October 2006

When radiolysis is induced in chloral hydrate solution flowing through a glass coil wound around a lead brick and irradiated from one side only, the rate of reaction depends on the flow rate. The effect resembles that for intermittent irradiation and makes it possible to estimate the mean lifetime of the free radical chain.
Inhibition of δ-Aminolevulinic Acid Dehydrase by δ-Oximinolevulinic Acid
Authors: Tschudy Donald P. , Collins Annie , Caughey Winslow S. , Kleinspehn George G.
Published: October 2006

δ-Oximinolevulinic acid competitively inhibits δ-aminolevulinic acid dehydrase at low concentrations.
Chromosome Number of the Chimpanzee,
Pan troglodytes
Authors: Young William J. , Merz Timothy , Ferguson-Smith Malcolm A. , Johnston Alan W.
Published: October 2006

The chromosome numbers of nine chimpanzees (
Pan troglodytes
) have been determined by the bone marrow technique. The diploid number in this species is 48, with a probable XX-XY sex chromosome constitution.
Permeability of Frog Skin to Choline
Authors: Kirschner Leonard B.
Published: October 2006

An inward movement of choline can be demonstrated across isolated skins of
Rana pipiens
when the outside is bathed by a saline made with choline chloride. This is in contrast to an earlier report indicating that skins of
R. esculenta
are impermeable to choline. The flux was very small and independent of the active transport of sodium by the skins. For most experiments choline can be used as an "inert" replacement for sodium in this preparation.
Effects of Temperature and Anions on Titration Curves of Frog Muscle
Authors: Engel Milton B. , Catchpole Hubert R. , Joseph Norman R.
Published: October 2006

Titration curves of frog muscle at 2°C and 25°C were determined in vivo. Lowered temperature decreases respiration without change of colloidal charge or of ion distribution as estimated from charge. Anions which are inhibitors or metabolites combine with muscle colloids, changing the distribution of other anions and cations.
Effects of Supernumerary Chromosomes on Production of Pigment in
Haplopappus gracilis
Authors: Jackson R. C. , Newmark Philip
Published: October 2006

One of the two types of supernumerary chromosomes found in
Haplopappus gracilis
effects pigment production in the achene walls. When one, two, and four supernumerary chromosomes were added to the basic complement, a corresponding increase in the amount of one type of pigment was found to occur. No overlapping of the effects on pigment production was observed among different numbers of supernumeraries or between the supernumeraries and normal chromosome complement.
Packaged Organic Materials as Monitoring Tools for Radionuclides
Authors: Williams Louis G. , Howell Michael , Straub Conrad P.
Published: October 2006

Pint-size perforated polyethylene bags were used as containers to test preserved tea, spinach, ion-exchange resin, live filamentous green algae, and dead filamentous green algae for the sorption and concentration of radionuclides from natural aquatic habitats and from a variety of laboratory controlled nutrient media. These packaged materials have been used to detect trace levels of radionuclides not found by the usual methods of analysis of the raw water itself for dissolved radionuclides.
Transplantation and Malignancy in a Companion-Host System on the Chorioallantoic Membrane
Authors: Leighton Joseph , Dreyer Donald A. , Mahoney Maurice J.
Published: October 2006

Pairs of tissue fragments in contact with one another were transplanted onto the chorioallantois. Ten days after transplantation, embryonic lung and liver were found to be accepted, without obvious infiltration of one another. When Walker tumor was substituted for either of the normal tissues, the pair of transplants was also accepted by the chorioallantois, and in addition there was extensive invasive replacement of the normal tissue by the cancer transplant.
Photodynamic Inactivation of Infectious Nucleic Acid
Authors: Chessin M.
Published: October 2006

Tobacco mosaic virus-infectious nucleic acid causes a color shift when combined with acridine orange, methylene blue, and safranine. A high concentration of acridine orange inactivates infectious nucleic acid even in darkness, while a mixture of nucleic acid with a low concentration of the dye must be exposed to visible light prior to inoculation for inactivation to occur.
Burst Firing in Dopamine Neurons Induced by
N
-Methyl-D-aspartate: Role of Electrogenic Sodium Pump
Authors: Johnson Steven W. , Seutin Vincent , North R. Alan
Published: October 2006

Dopamine-containing neurons of the mammalian midbrain are required for normal behavior and movements. In vivo they fire action potentials in bursts, but in vitro they discharge regularly spaced action potentials. Burst firing in vitro has now been shown to be robustly induced by the glutamate agonist
N
-methyl-D-aspartate (NMDA) although not by the non-NMDA agonists kainate or quisqualate. The hyperpolarization between bursts of action potentials results from electrogenic sodium ion extrusion by a ouabain-sensitive pump. This mechanism of burst generation in mammalian neurons may be important in the pathophysiology of schizophrenia and Parkinson's disease.
Changes in Incidence of Sex Chromatin in Subcultured Cells
Authors: Orsi Ernest V. , Wallace Roslyn E. , Ritter Hilda B.
Published: October 2006

Sex chromatin counts of subcultured cells of both female human mammary tumor and female rabbit kidney show a considerable drop from an initial high level. Cultures in which sex chromatin persists also retain the viral insensitivity of their source material.
Measurement of Geotropic Sensitivity of Seedlings
Authors: Lyon Charles J.
Published: October 2006

By a new method of applying small centrifugal forces, produced by vibration of wires which hold corn seedlings on a horizontal clinostat, threshold values of the required gravitational force have been obtained. In darkness the centrifugal acceleration need be only about 0.04 cm/sec
2
, while in weak light it must be 10 times as great.
Limitations on Space Flight due to Cosmic Radiations
Authors: Curtis Howard J.
Published: October 2006

These conclusions may be summarized as follows:

1) Flight below the Van Allen belts seems reasonably safe without radiation shielding.

2) It is probably impractical to shield a rocket sufficiently to permit a man to remain in the inner Van Allen belt for more than about an hour, but it should be possible for him to go through it without serious harm.

3) Shielding for the outer Van Allen belt is possible but would have to be quite heavy if a stay of more than a few hours were contemplated.

4) The primary cosmic radiation is not intense enough to deliver a serious radiation dose, even for exposures of a few weeks, and the heavy cosmic ray primaries do not seem to present an unusual hazard.
Growth Inhibition of Insects and a Fungus by Indole-3-Acetonitrile
Authors: Smissman Edward E. , Beck Standley D. , Boots Marvin R.
Published: October 2006

Indole-3-acetonitrile obtained from cabbage has been found to inhibit growth of
Pyrausta nubilalis
(Hbn.),
Galleria mellonella
(L.), and
Penicillium chrysogenum
.
Variability in Male Stature as Function of Adolescent Maturation Rate
Authors: Livson Norman , McNeill David
Published: October 2006

Boys who mature very early and, to a lesser degree, those who mature later than average show less variation in stature than boys who are somewhat early in adolescent development. These variability differences are paralleled in the heights of the mothers and fathers except in the case of boys who mature very early; there is far less variability in height among these boys than among their parents.
Radioprotection by Mitotic Inhibitors and Mercaptoethylamine
Authors: Rothe William E. , Grenan Marie M.
Published: October 2006

In the mouse, chemical interference with cellular proliferation alters the radiosensitivity of the bone marrow, and this results in protection from otherwise lethal x-irradiation. When intestinal damage is minimized by appropriate timing and dosage, many mitotic inhibitors increase radioresistance and enhance the protective effects of mercaptoethylamine.
Auditory Information from Subcortical Electrical Stimulation in Cats
Authors: Nieder Philip C. , Neff William D.
Published: October 2006

Animals trained to respond to sound stimuli were found to perform the learned response when they were electrically stimulated through electrodes chronically implanted in subcortical structures of the auditory pathway. Other animals trained to respond to electrical stimulation of subcortical auditory structures showed differential transfer effects depending on the positions of the stimulating electrodes.
Immunization as a Factor Affecting the Course of Septicemic Anthrax
Authors: Klein Frederick , Mahlandt Bill G. , Lincoln Ralph E. , Dearmon Ira A. , Fernelius Albert L.
Published: October 2006

Immunization of guinea pigs with alum-precipitated antigen increased resistance approximately 1600 times. The growth rate of
Bacillus anthracis
, in the septicemic phase, was the same in both normal and immunized animals; however, the number of bacilli per milliliter of blood at death was decreased by 75 percent in immunized animals. Neither the enhancement of virulence by treatment with egg yolk nor the size of the challenge dose affected the growth rate or the number of bacilli per milliliter of blood at death. Mean time to death for the treatments tested varied from approximately 20 to 100 hours. Nonimmunized animals challenged with a strain of low virulence had a terminal number of bacilli per milliliter of blood and a growth rate in the blood the same as that for the highly virulent strain.
Growth of Sporangiophores of
Phycomyces
Immersed in Water
Authors: Stifler Richard Bond
Published: October 2006

Sporangiophores of
Phycomyces
are capable of sustained growth when immersed in aerated water, and under these conditions they are negatively phototropic.
Blockade of Deoxyribonucleic Acid Synthesis by Deuterium Oxide
Authors: Gross Paul R. , Harding Clifford V.
Published: October 2006

Interference with deoxyribonucleic acid replication need not be a
primary
mechanism in the blockade of cell division by deuterium oxide, but current hypotheses on the molecular basis of the blockade do suggest that such interference might take place under appropriate conditions. Autoradiographic experiments support the suggestion, for whereas normal sea urchin eggs incorporate H
3
-thymidine into deoxyribonucleic acid from almost the beginning of development, cells immersed in deuterium-enriched media do not. Blockade of mitosis and inhibition of thymidine incorporation are simultaneously relieved when the eggs are returned to normal water.
Specificity of Discrimination Learning to the Original Context
Authors: Logan Frank A.
Published: October 2006

Rats learned a black-white discrimination at one location in a maze. Subsequently, most rats required over half as many trials to learn the same discrimination when it was placed in another location in the maze. Additional evidence was consistent with the assumption that the relevant cues are, in effect, modified by interaction with the contextual stimuli.
An Advancing Glacier in Canada
Authors: West Robert , Maki Arthur
Published: October 2006

The Commander Glacier, in the Purcell Range of interior British Columbia, advanced 810 ± 50 feet in the 6 years 1954-1960. The advance may be a response to a general cooling trend previously noted elsewhere in the Pacific Northwest.
Phototropic Inversion in
Phycomyces
Authors: Castle E. S.
Published: October 2006

Transient reversed bending follows an adequate step-up in light intensity given a bending cell from any direction around its axis, yet the plane of the response is specifically that in which prior phototropic bending occurred. The cell "remembers" what it was doing and reverses this in the ensuing light-growth response. Antecedent asymmetric growth itself built the pattern for reversal.
Age Changes in Adenine Nucleotides in Flight Muscle of Male House Fly
Authors: Rockstein Morris , Gutfreund Donald E.
Published: October 2006

Under standard conditions of temperature, humidity, and (artificial) diet, loss in flight ability is paralleled by a decline of up to 66⅔ percent in activity of enzymes dephosphorylating organophosphorous compounds in the thoracic flight muscle. Concomitantly, the content of adenosine triphosphate in the flight muscle increases five times, while the content of adenosine monophosphate correspondingly diminishes.
Pollination of Saguaro Cactus by Doves, Nectar-Feeding Bats, and Honey Bees
Authors: Alcorn Stanley M. , McGregor S. E. , Olin George
Published: October 2006

In a large cage, free-flying western white-winged doves, nectar-feeding
Leptonycteris
bats, and honey bees were each effective as cross-pollinators of self-sterile saguaro flowers. Seed production and seed viability were not significantly different in fruit from flowers pollinated by these agents. Pollination is not a limiting factor in saguaro repopulation.
Ultrahigh-Energy Accelerators
Authors: Wilson Robert R.
Published: October 2006

Summarizing, one can say that the construction of ultrahigh-energy accelerators will be justifiable even at presently predictable costs. There is little doubt that eventually physicists will push into the domain of superintensity as well as that of superenergy. If they do this, it will be because the information that will then become available will be needed in order to formulate a more complete picture of nature. For the time being, we should examine the results of the 30-Gev synchrotrons in the light of their bearing on these large constructions of the future. But if these projects are to be realized in a time comparable to our lifetime, then those study projects which have become a necessary prelude to actual construction should be started now.
High-Rate Laboratory Filtration with Büchner Funnels
Authors: Shapiro Joseph
Published: October 2006

A method is described for greatly increasing the efficiency of Büchner funnels by utilizing a much larger fraction of the filter paper surface. The method also makes it possible to use Millipore filters efficiently on Büchner funnels.
The Humoral Regulation of Breathing
Authors: Blide Richard W. , Workman John M. , Armstrong Bruce W. , Hurt Holcombe H.
Published: October 2006

The classic concept that breathing is regulated only by chemoreceptor mechanisms in the arterial blood stream— the respiratory center, the carotid and aortic bodies—has been modified in two ways. It has been expanded by postulating another chemoreceptor which reacts to the composition of mixed venous blood. It has been qualified by questioning the assumption that the respiratory center has physiologically significant chemosensitivity. (The respiratory center is considered to be, on the contrary, primarily a computing mechanism that integrates information received from chemoreceptors responding to both arterial and mixed venous blood.)

By postulating a chemoreceptor mechanism which reacts to the composition of mixed venous blood, a variety of ventilatory responses can be accounted for with a unified and semiquantitative concept based on the ventilatory response to exercise.

For the quantitative description of exercise, data obtained from normal men at rest and during exercise have been used to develop several equations which describe the ventilatory response to exercise in terms of P
CO
2
and H
+
of arterial and mixed venous blood. The simplest of these equations, yet a useful one, is the following:

V̇
= 1.1 H
+
a
+ 2.3
Pv̅
CO
2
- 135 (5
a
)

which states that the volume of breathing is determined by the algebraic summation of influences in arterial and mixed venous blood.

Ventilatory responses, as measured in several experimental and clinical situations characterized by acid-base imbalance and associated hyperpnea, have been compared with the ventilation predicted by this equation and by the equation which quantifies Gray's multiple-factor theory. Equation 5
a
estimated the various ventilatory responses as closely as the multiple-factor theory equation did. Equation 5
a
was also able to predict ventilation during exercise. It is concluded, therefore, that the hyperpnea of muscular exercise may be a generally applicable expression of the ventilatory response to alterations of the composition of both arterial and mixed venous blood.

When applied to the ventilatory responses of cross-perfused animals during exercise, the concept gives a satisfactory qualitative explanation of the various observations.

Although there is strong indirect evidence that a chemoreceptor mechanism exists which reacts to the composition of mixed venous blood and whose activity can be quantified, the equations that have been developed are not definitive expressions of the stimuli which regulate breathing. That the equations apply as well as they do, in view of the known errors of fact in their development, is probably the best evidence yet adduced for the essential validity of the present concept.
Identity of a Fungus Causing Blue Stain in Balsam Fir
Authors: Etheridge David E. , Pomerleau René
Published: October 2006

Blue-stained balsam fir wood [
Abies balsamea
(L.) Mill.] consistently yielded cultures of a nonsporulating fungus which were found to be the same as those obtained from ascospores of
Amphisphaeria thujina
(Peck) Sacc. collected from dead branches of this host. This blue stain appears to be identical with a previously reported but hitherto unidentified stain of conifers. The association of
Amphisphaeria
with stain in living trees does not appear to have been recognized before.
A Bacteriophage Specific for F—
Salmonella
Strains
Authors: Zinder Norton D.
Published: October 2006

A bacteriophage is described which grows on recipient (F-) and not on donor (Hfr, F+, or F′) salmonella. The reason for this differential is unknown, since the phage attaches to all mating types, but progeny ensue only from female bacteria. Purification of this phage has been accomplished. A procedure is described for quantitatively determining either the acquisition or loss of the F agent by bacteria.
Partial Metamorphosis in
Anomia simplex
Authors: Loosanoff V. L.
Published: October 2006

Many larvae of the common bivalve,
Anomia simplex
, when grown under laboratory conditions, exhibited a partial metamorphosis. They attained a considerably larger size than that at which larvae normally set. The partial metamorphosis was also characterized by the disappearance of velum, but the retention of a functional foot. Moreover, these organisms were not able to attach to the substratum, and their shells showed a distinct demarcation line between larval and adult portions
Potential versus Time Asymmetries in Adsorption Membranes
Authors: Sjodin R. A.
Published: October 2006

An outer membrane surface is assumed to take up potassium ions in a manner analogous to adsorption. This model, already successful in predicting transmembrane flux, is shown to predict also an asymmetrical potential-time relation depending on the direction of the concentration changes. The results may have some value in explaining recent observations of similar effects in muscle.
Optical Properties of Sugar Flavazoles
Authors: Nordin P. , Doty M.
Published: October 2006

The absorption of glucose flavazole was measured in the ultraviolet and visible regions of the spectrum. Three maxima were observed: 267, 335, and 410 mμ. The absorption at 410 mμ follows Beer's law with 70 percent propanol or water as solvent. The molar absorptivities for glucose, maltose, and lactose flavazoles were the same and equal to 3.7 × 10
3
.
Isolation and Identification of a Neuroactive Factor from
Lathyrus latifolius
Authors: Ressler Charlotte , Redstone Paul A. , Erenberg Renée H.
Published: October 2006

A neuroactive principle of
Lathyrus latifolius
has been isolated in crystalline form as a monohydrochloride and has been identified as L-α,γ-diaminobutyric acid. This amino acid has also been found in very high concentration in the toxic seed of
Lathyrus sylvestris Wagneri
A structural relationship between this factor, the lathyrus factor from
Lathyrus odoratus
, and β-cyano-L-alanine, a new, synthetic neuroactive amino acid nitrile, is pointed out, and a possible biosynthetic pathway relating these is indicated.
L-Tyrosine Oxidase System in Tuber of Nutsedge
Authors: Palmer Rupert D.
Published: October 2006

In the nutsedge,
Cyperus rotundus
L., the oxidation of L-tyrosine follows steps similar to those reported for mammalian liver and
Blattella conjuncta
. The system is activated by α-ketoglutarate, L-ascorbic acid, glutathione, and pyridoxal phosphate. Folic acid markedly inhibits the reaction.
Localization of Porphyrin Fluorescence in Planarians
Authors: MacRae Edith Krugelis
Published: October 2006

Two species of planarians were studied by fluorescence microscopy. Red fluorescence of uroporphyrin was observed localized in the epidermal rhabdites and subepidermal rhabdite-containing gland cells. Fluorescence was observed in isolated rhabdites of homogenates, but was not seen in rhabdites of the living animal. The identity of rhabdites was established by their location, shape, size, and acidophilic staining properties.
Aging in Irradiated and Nonirradiated Hydras
Authors: Stevenson J. Ross , Buchsbaum Ralph
Published: October 2006

Evidence is presented that as hydras become older they bud more slowly and become more susceptible to adverse conditions. In these studies, a 2000-roentgen dose of x-radiation did not seem to affect the rate of these changes. The mean number of tentacles did not change with age.
Radiation Dosimeter Utilizing the Thermoluminescence of Lithium Fluoride
Authors: Cameron J. R. , Daniels F. , Johnson Noye , Kenney G.
Published: October 2006

A dosimeter, with little wavelength dependence and large useful energy range for electromagnetic radiation, which is simple to use and read, has been developed. It appears to have applications in personnel monitoring as well as radiation research.
Fluorine Substitution Affects Decarboxylation of 2,4-Dichlorophenoxyacetic Acid in Apple
Authors: Edgerton L. J. , Hoffman M. B.
Published: October 2006

Marked differences exist in the rate at which 2,4-dichlorophenoxyacetic acid (2,4-D) is broken down by different plant species and varieties. This activity has been measured by collecting carbon dioxide from leaves treated with carboxyl-C
14
labeled compounds. The substitution of fluorine for chlorine in the 4-position of 2,4-D inhibits this decarboxylation in leaves which are able to break down 2,4-D rapidly.
Natural Tritium Measurements by Ethane Counting
Authors: Bainbridge A. E. , Sandoval Paula , Suess H. E.
Published: October 2006

A method is described for the synthesis of ethane from hydrogen that is at present used for the counting of low-level tritium activity at the La Jolla tritium laboratory. The reaction procedure is simple and involves the mixing of the hydrogen with acetylene over a colloidal palladium catalyst. Counting characteristics of ethane are found to be ideal. With a 1-liter counter filled to three atmospheres of ethane, only a tenfold tritium enrichment is necessary in order to obtain a sensitivity of 0.32 counts per minute per tritium unit.
Mass Culture of Phytoplankton as Foods for Metazoans
Authors: Davis Harry C. , Ukeles Ravenna
Published: October 2006

An apparatus for mass culture of photosynthetic microorganisms has been developed to grow algae for use as foods for larval and juvenile mollusks in studies of their physiological requirements. The apparatus consists of a series of 5-gal growth chambers, and the system can be enlarged to yield any desired volume of algae by replication of basic units. Approximately 50 lit. of algal suspension, averaging about 0.5 ml of packed wet cells per liter, are produced daily.
Nonlinear Property of the Visual System at Fusion
Authors: Forsyth D. M. , Brown Charles R.
Published: October 2006

The response of the visual system to intermittent stimulation at rates above the fusion point is generally considered to be independent of frequency, that is, linear with respect to time-average luminance. However, trains of 1000 light pulses per second alternated successively with trains of 500 light pulses per second may be perceived as flickering even though the time-average luminance is the same in each train.