bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermal Denaturation of Collagen in the Dispersed and Solid State
Authors: Gross Jerome
Published: October 2006

Thermal denaturation temperature of newly reconstituted collagen fibrils from rat tail tendons is 52°C compared with 42°C for neutral solutions. This suggests that the increase in concentration of collagen within the fibril increases the stability of the individual molecules. The absence of firm intermolecular bonds in these fibrils rules out crosslinking as an explanation for increased stability. "Aging" at 37°C up to 1 year raises the shrinkage temperature of reconstituted fibrous gels by 4° to 6°C and greatly increases resistance to dissolution at high temperature. The newly formed fibrils dissolve without shrinking, whereas older gels exhibit shrinkage before dissolution. Since nearly all extractable collagen is in the form of fibrillar aggregates in tissue, it is unlikely that thermal denaturation occurs at body temperature; therefore it could not be involved as a necessary stage in collagen resorption.
Behavior of Infant Monkeys: Differences Attributable to Mode of Birth
Authors: Meier Gilbert W.
Published: October 2006

A comparison of behavior of infant monkeys shortly after birth reveals differences in reactivity which can be related to the route of delivery, whether vaginal or cesarean section. The depression of behavior in the surgically delivered infants persists through day 5 postpartum and ultimately appears as lowered conditionability. Anesthetics or other drugs are not causal factors.
Behavior: Persistence of Shock-Induced Aggression
Authors: Ulrich R. E. , Craine W. H.
Published: October 2006

Previous research has shown that aversive stimulation causes aggression in several lower species of mammals prior to any specific conditioning. Our results show that fighting in response to shock tends to persist in spite of negative reinforcement for other behavior. The frequency of shock-induced fights decreased significantly only when the reinforcement of shock termination was made contingent upon a specific nonaggressive response.
Pursuit Eye Movements in the Absence of a Moving Visual Stimulus
Authors: Deckert Gordon H.
Published: October 2006

Subjects instructed to imagine a beating pendulum develop pursuit eye movements of a frequency comparable to the frequency of a previously visualized real pendulum. The appearance of pursuit rather than saccadic movements supports an "outflow" theory for central control of eye movement and suggests an objective technique for the identification of certain types of visual imagery.
Experimental Reversal of Germ Cells in Ovaries of Fetal Mice
Authors: Turner C. Donnell , Asakawa Hiroshi
Published: October 2006

When heterosexual pairs of gonads of fetal mice were homotransplanted in close contact with each other below the kidney capsule of castrated adult hosts, the testis developed normally for this environment, but the ovary became an ovotestis. The medulla of the ovotestis contained dilated seminiferous tubules in which spermatogenesis progressed to the point at which secondary spermatocytes were produced. Under these conditions, germ cells, genetically determined as ova, underwent differentiation toward spermatozoa. This is the second clear case of germ cell reversal by experimental means in a mammalian species.
Polymer Similar to Polydeoxyadenylate-Thymidylate in Various Tissues of a Marine Crab
Authors: Cheng Ts'ai-ying , Sueoka Noboru
Published: October 2006

Several species of a genus
Cancer
have a DNA that has a light buoyant density and that contains mainly deoxyadenylate and thymidylate. The presence of this polymer was demonstrated previously in testes and vas deferens. By a modified procedure for isolating DNA, the muscles, liver, and eggs of
Cancer borealis
are also shown to contain the deoxyadenylate-thymidylate-like polymer.
Selecting T Cell Receptors with High Affinity for Self-MHC by Decreasing the Contribution of CD8
Authors: Sherman Linda A. , Hesse Sabine V. , Irwin Michael J. , La Face Drake , Peterson Per
Published: October 2006

Selective events during T cell repertoire development in the thymus include both the positive selection of cells whose receptors recognize self-major histocompatibility complex (MHC) molecules and negative selection (tolerance) of cells whose interaction with self-MHC is of high affinity. The affinity of T cell interactions with class I MHC molecules includes contributions by both the T cell receptor and the CD8 coreceptor. Therefore, by decreasing the affinity of the interaction with CD8, T cells whose receptors have relatively high affinities for self-MHC may survive negative selection. Such T cells were generated and those T cells reactive with self-MHC plus antigen also displayed low affinity for self.
A Surface Protease and the Invasive Character of Plague
Authors: Sodeinde Ola A. , Subrahmanyam Y. V. B. K. , Stark Kimberly , Quan Thomas , Bao Youdi , Goguen Jon D.
Published: October 2006

A 9.5-kilobase plasmid of
Yersinia pestis
, the causative agent of plague, is required for high virulence when mice are inoculated with the bacterium by subcutaneous injection. Inactivation of the plasmid gene
pla
, which encodes a surface protease, increased the median lethal dose of the bacteria for mice by a millionfold. Moreover, cloned
pla
was sufficient to restore segregants lacking the entire
pla
-
bearing plasmid to full virulence. Both
pla
+
strains injected subcutaneously and
pla
-
mutants injected intravenously reached high titers in liver and spleen of infected mice, whereas
pla
-
mutants injected subcutaneously failed to do so even though they establish a sustained local infection at the injection site. More inflammatory cells accumulated in lesions caused by the
pla
-
mutants than in lesions produced by the
pla
+
parent. The Pla protease was shown to be a plasminogen activator with unusual kinetic properties. It can also cleave complement C3 at a specific site.
Possible Cyclic Nucleotide Regulation of Calcium Mediating Myocardial Contraction
Authors: Schwartz Arnold , Endman Mark L. , Ezrailson Edward G. , Lehotay Denis C. , Levey Gerald
Published: October 2006

An inhibitor of adenylate and guanylate cyclases was tested on strips of left atria from rabbits. Effects of catecholamines (cardiotonic) and of acetylcholine (cardiodepressive) were blocked, and positive force-frequency was converted to negative. Ouabain produced only contracture without positive inotropy. The cardiotonic effect of increased calcium remained. Data suggest that cyclic nucleotides modulate calcium associated with these stimuli.
Ethanol Accumulation in the Rumen after Overfeeding with Readily Fermentable Carbohydrate
Authors: Allison Milton J. , Dougherty R. W. , Bucklin J. A. , Snyder E. E.
Published: October 2006

A neutral volatile substance in ruminal contents from sheep suffering from acute indigestion due to overfeeding has been identified as ethanol. Ethanol was consistently observed in ruminal material from both cattle and sheep after they had been fed large amounts of readily fermentable carbohydrate.
Origin of Oceanic Manganese Minerals
Authors: Arrhenius G. , Mero J. , Korkisch J.
Published: October 2006

A criterion is suggested for discrimination between ferromanganese oxide minerals, deposited after the introduction of manganese and associated elements in sea water solution at submarine vulcanism, and minerals which are slowly formed from dilute solution, largely of continental origin. The simultaneous injection of thorium into the ocean by submarine vulcanism is indicated, and its differentiation from continental thorium introduced into the ocean by runoff is discussed.
Radioiodine Metabolism in Children and Adults after the Ingestion of Very Small Doses
Authors: Van Dilla M. A. , Fulwyler M. J.
Published: October 2006

One day after oral ingestion of very small doses (about 0.01 microcurie) of an I
131
/I
125
mixture, the radioiodine content of the thyroid gland was similar in children and adults (about 20 percent of the dose ingested) as was the biological half-life of the iodine (about 90 days). Measurements were made in 15 minutes by means of a whole-body counter with a cylindrical sodium iodide (Tl) crystal, 20 cm in diameter and 10 cm thick.
Estrogen Administered Neonatally Affects Adult Sexual Behavior in Male and Female Rats
Authors: Levine Seymour , Mullins Richard
Published: October 2006

The injection of 100 μg of estradiol benzoate into female rats 96 hours after birth abolished sexual receptivity in adulthood, even with estrogen and progesterone replacement after ovariectomy. The administration of testosterone propionate to these animals in adulthood elicited the full pattern of male sexual behavior. The same dose of estrogen given to male rats 96 hours after birth produced adults which were unable to achieve intromission, although they mounted as frequently as normal animals. Testosterone replacement after castration in adulthood reproduced this abnormal behavior.
Schistosomiasis: Age of Snails and Susceptibility to X-irradiation
Authors: Szumlewicz Alina Perlowagora
Published: October 2006

Studies on sensitivity of
Australorbis glabratus
to x-rays have defined the chronological and physiological age at which the snail is most sensitive to radiation damage. Results showed that the dose producing 50-percent mortality at 30 days after irradiation increased with age but that at 90 days it was practically constant from 2 to 210 days of age. In view of the available data on recovery from radiation damage caused by doses from 6000 to 9000 roentgens it is suggested that doses above those causing 50 percent lethality at 60 days but below those causing 50 percent lethality for 30 days should be considered in setting up "radiation barriers" to control snails in water-distribution systems.
Inherited Male-Producing Factor in an Insect That Produces Its Males from Unfertilized Eggs
Authors: Wilkes A.
Published: October 2006

An inherited factor causing the normal sex ratio of 92 percent females to drop to about 5 percent has been produced by selective breeding in a laboratory strain of the arrhenotokous parasitic wasp
Dahlbominus fuliginosus
(Nees) (Hymenoptera, Eulophidae). The factor is known to be of genetic origin and is sex-limited, being transmitted by females to their sons. Its effect on the sex ratio is constant and not influenced by the female parent, the host, or the environment.
Insect Fertility: Inhibition by Folic Acid Derivatives
Authors: Crystal Maxwell M.
Published: October 2006

Folic acid antagonists inhibited oviposition by screw-worm flies [
Cochliomyia hominivorax
(Coquerel); Diptera: Calliphoridae]. Fertility was unaltered when sufficient folic acid was administered simultaneously, or it was partly restored spontaneously about 2 weeks after treatment. Folic acid antagonists principally affected only maturing eggs at any age, rather than those already matured.
Habituation of Responses to Novel Stimuli in Monkeys with Selective Frontal Lesions
Authors: Butter Charles M.
Published: October 2006

Monkeys with surgically produced lesions of the orbital frontal cortex, monkeys with lesions of the lateral frontal cortex, and normal controls were tested for the effects of repeated presentation of novel stimuli on lever-pressing for food rewards. The results support the conclusion that the habituation of responses to novel stimuli was more impaired in monkeys with orbital frontal lesions than in monkeys with lateral frontal lesions.
Temperature Changes in the Rat in Response to Feeding
Authors: Rampone Alfred J. , Shirasu Myron E.
Published: October 2006

Feeding activity in fasted rats resulted in an immediate increase in brain temperature and a decrease in rectal temperature. The temperature changes did not correlate with any specific property of the food nor with the amount eaten. The responses were judged to be the result of reflex vasomotor changes resulting in widespread shifts in the direction of blood flow. They were not related to the regulation of food intake.
Periodic Phenomena Observed with Spherical Particles in Horizontal Pipes
Authors: Thomas David G.
Published: October 2006

A thin layer of spherical particles resting on the bottom of a round pipe was observed to form into essentially equally spaced clumps or islands at fluid velocities only slightly greater than those required to initiate particle movement. This phenomenon appeared to be similar to dune formation in open channels since the ratio of the square of the stream velocity, U, and the product of the gravitational constant,
g
L, and the island wavelength, λ, was correlated by the same function of island height and velocity, particle diameter, and fluid depth regardless of whether the flow was through a closed conduit or an open channel.
Variation of Cesium in the Ocean
Authors: Folsom T. R. , Feldman C. , Rains T. C.
Published: October 2006

Samples of sea water from several oceans and several depths were analyzed for natural cesium by flame photometry with precision of about 3.5 percent. The average of 16 assays of surface water from four oceans was 0.37 microgram per liter, somewhat less than the average previously reported. The average cesium concentration in samples taken between 500 and 1500 meters was about 14 percent higher than the surface average, suggesting that cesium may be transported downward by particulate material. Natural cesium is now somewhat easier to study in the ocean than radiocesium from fallout is, and information on one complements the other.
Immunologically Determined and Competent Cells Are Affected Differentially by Actinomycin D
Authors: Weiler Eberhardt
Published: October 2006

A differential effect of actinomycin D on the capacity of mouse peritoneal fluid cells to form antibody after cell transfer has been found. Actinomycin treatment in vitro during transfer inhibited the delayed response toward a first antigen, administered before transfer, while the competence of cells to respond to a second antigen, given after transfer, was not affected.
Intestinal Disaccharidases: Absence in Two Species of Sea Lions
Authors: Sunshine Philip , Kretchmer Norman
Published: October 2006

Pups of both the California and Stellar sea lions have no intestinal enzymes for hydrolysis of sucrose, lactose, cellobiose, or trehalose. If these animals were given lactose or sucrose, they developed severe fermentative diarrhea and weight loss similar to the clinical syndrome encountered in infants with either hereditary or acquired intolerance to disaccharides.
Reevaluation of Assays Used To Show RNA Induction of Glucose-6-Phosphatase in Ascites Cells
Authors: Imsande John , Ephrussi Boris
Published: October 2006

The standard procedures—Glucostat method and Fiske-Subbarow phosphorus determination—are inadequate for the assay of glucose-6-phosphatase activity in Ehrlich ascites cells. Therefore, RNA induction of this enzyme in ascites cells, even if it occurs, cannot be demonstrated by these procedures.
Knots in
Leucothrix mucor
Authors: Brock Thomas D.
Published: October 2006

The filaments of
Leucothrix mucor
are able to form true knots under certain cultural conditions. Such structures have apparently not been previously seen in filamentous organisms. As the culture ages, the knots become tighter and eventually the cells in the knot region fuse and form a large bulb. The filament breaks on each side of the bulb, and two shorter filaments and a free bulb are produced. The free bulbs have not been observed to grow into new filaments.
Oxygen Isotopic Composition of Some Right-and Left-Coiled Foraminifera
Authors: Longinelli A. , Tongiorgi E.
Published: October 2006

Right- and left-coiled foraminiferal species were collected from living and fossil faunas from different habitats. A difference in the oxygen isotopic composition of right- and left-coiled specimens was observed. Deposition of calcium carbonate by right- and left-coiled Foraminifera takes place, at least in the species measured, during non-coincident periods of the year.
Quantasome: Size and Composition
Authors: Park Roderic B. , Biggins John
Published: October 2006

The quantasome as seen in a two-dimensional crystalline array is 185 Å long, 155 Å wide, and 100 Å thick. The surface of the quantasome appears to contain four or more subunits. The molecular weight, determined from volume and density measurements, is 2 × 10
6
. This is twice the minimum molecular weight calculated from the manganese content and corresponds to a chlorophyll content of 230 chlorophyll molecules per quantasome.
Haptoglobin Binding Capacity of Certain Abnormal Hemoglobins
Authors: Nagel Ronald L. , Ranney Helen M.
Published: October 2006

Hemoglobins H and Bart's failed to bind human haptoglobin. The binding of hemoglobins A
2
, F, I, and Lepore was comparable to that of hemoglobin A. These findings suggest that configurational differences or the absence of alpha chain dimers was responsible for the lack of binding of hemoglobins H and Bart's.
Night-Caught and Day-Caught Larvae of the California Sardine
Authors: Isaacs John D.
Published: October 2006

Some 70,000 larvae of the California sardine, collected from about 10,000 plankton hauls over the years 1950 to 1957, have been sorted by lengths and enumerated. The numbers of the day-caught larvae are very closely a numerical measure of the apparent mortality as indicated by the night-caught larvae. Over a considerable interval of size, the night-caught larvae appear to be representative of the entire larval population, but the day-caught larvae may represent a fraction that is a measure of the natural mortality of the population.
2-Aminoethylphosphonic Acid in Insoluble Protein of the Sea Anemone
Metridium dianthus
Authors: Quin Louis D.
Published: October 2006

2-Aminoethylphosphonic acid has been isolated from a hydrolysate of insoluble proteinaceous material of Metridium dianthus in 1.1 percent yield. It appears to be incorporated in the protein structure; when trichloroacetic acid is added to partial hydrolysates, precipitates form from which this compound is released on complete hydrolysis. The phosphonic acid was also detected in hydrolysates of the 70-percent ethanol- and chloroform-soluble fractions of the sea anemone. The total amount isolated accounted for 0.99 percent of the dry weight of the animal.
Reduction of Dimethylsulfoxide to Dimethylsulfide in the Cat
Authors: Distefano Victor , Borgstedt Harold H.
Published: October 2006

A peculiar sweetish odor was noted in the exhaled breath of cats treated with dimethylsulfoxide. By means of gas chromatographic and mass spectrographic techniques, the responsible compound was identified as dimethylsulfide.
Linear Polymerization of a Gastropod Hemocyanin
Authors: Condie Richard M. , Langer Richard B.
Published: October 2006

The decreased solubility of a gastropod hemocyanin in the region of the isoelectric point has been correlated with a sharp increase in light scattering produced by the protein in solution. Electron microscopic observations on negatively stained spray preparations in the isoelectric region demonstrated that the formation of linear polymers of the molecule underlies both the increase in light scattering as well as the decreased solubility of the protein. While the linear polymerization produces chains of varying length with no evidence of interaction between chains, the polymerization proceeds with a high degree of ordering of individual molecules. On either side of the isoelectric region of this hemocyanin two forms of molecules are present, rectangular and circular. The rectangular molecules polymerize in an end-to-end fashion in the isoelectric region. The rectangular molecules which participate in the polymerization appear to be divided perpendicularly to their length into three major segments.
Lymphoid Organs and Normal Gamma-Globulin in the Rat
Authors: Andersen Stig Bryde , Bierring Franz
Published: October 2006

Serum gamma-globulin was determined in adult rats several months after total thymectomy, subtotal splenectomy, or a combination of total thymectomy, subtotal splenectomy, and subtotal lymphadenectomy. The thymus apparently is of little importance in the production of normal gamma-globulin, but it may influence the production of albumin because a reduction of serum albumin was only seen in groups where thymectomy was performed. The spleen seems to produce normal gamma-globulin to a greater extent than lymphoid tissue elsewhere in the body.
Negative Inotropic Effect of the Vagus Nerves upon the Canine Ventricle
Authors: DeGeest Hilaire , Levy Matthew N. , Zieske Harrison
Published: October 2006

In an innervated, paced, left heart preparation in which the left ventricle contracted against a constant volume of incompressible fluid (isovolumetric preparation), electrical stimulation of the distal end of either sectioned cervical vagus nerve decreased the peak tension generated by the left ventricle. The vagi, therefore, exert a negative inotropic effect directly upon the ventricular myocardium.
Heparinic Acids: Determination of Equivalent Weights and Sulfate to Carboxyl Ratios
Authors: Kuettner Klaus E. , Lindenbaum Arthur
Published: October 2006

By means of an automatic titration apparatus, a polyelectrolyte of biological origin, heparin, from two animal sources, was found to have an average equivalent weight of 170.0, a sulfate content of 34.44 percent, and a sulfate to carboxyl ratio of 2.59.
Cariostatic Effect of Phosphates
Authors: McClure F. J.
Published: October 2006

The caries-preventive effect of phosphate additives in cariogenic diets fed to white rats has been further demonstrated. Diammonium phosphate, β-glycerol phosphate, and sodium phytate again were shown to be caries-inhibiting, as was a 1,6-fructose diphosphate. The caries-inhibiting action of organic phosphates may coincide with a caries-protective factor presumed lost in the refining of sugar and in the processing of certain cereal foods.
Temperature Dependence of Anesthesia in Goldfish
Authors: Cherkin Arthur , Catchpool J. F.
Published: October 2006

The anesthetizing concentrations in water of diethyl ether, chloroform, halothane (CF
3
CClBrH), and methaxyflurane (CHCl
2
CF
2
OCH
3
) have been determined for temperature-acclimated goldfish (Carassius auratus) at 5° to 30°C. At 20°C, the concentrations that anesthetize 50 percent of the fish are 2160, 167, 76.4, and 57.0 mg/liter, respectively; the corresponding partial pressures are 13.0, 3.36, 4.12, and 0.67 mm-Hg. The anesthetizing partial pressures increase with body temperature, with enthalpies of 8.6, 13.2, 12.5, and 12.3 kcal/mole, respectively.
Carotenoids of Cavernicolous Crayfish
Authors: Wolfe Douglas A. , Cornwell David G.
Published: October 2006

Small amounts of β-carotene and lutein were found in
Orconectes pellucidus pellucidus
.
Cambarus bartonii tenebrosus
from the same cave contained much less carotenoid than surface crayfish. Astaxanthin, the principal carotenoid of most Crustacea, was absent from
O. p. pellucidus
, but accounted for 83 percent of the carotenoid of
C. b. tenebrosus
. These findings support other observations that pigmentation is dependent on the amount of carotenoid in the diet rather than on the presence of light. Furthermore, they suggest that
O. p. pellucidus
has lost or has never developed the ability to oxidize dietary carotenoids.
Alloocimene: Absence in Cigarette Smoke
Authors: Mold James D. , Walker Thomas B. , Williams James B.
Published: October 2006

Alloocimene was not found to be a constituent of cigarette smoke under test conditions that allowed 86 percent recovery when authentic alloocimene was added to the smoke. In the same experiments dipentene was found to the extent of 0.2 percent of the smoke condensate.
Prevention of a Mental Defect of Phenylketonuria with Serotonin Congeners such as Melatonin or Hydroxytryptophan
Authors: Woolley D. W. , van der Hoeven T.
Published: October 2006

Mice made phenylketonuric from birth until maturity by continuous administration of phenylalanine plus tyrosine had a subnormal maze-learning ability which was largely prevented when serotonin congeners such as melatonin or 5-hydroxytryptophan were administered continuously from birth to maturity. These results were interpreted to mean that the mental failure of experimental phenylketonuria is attributable to the serotonin deficiency imposed by it in infancy.
Glutamine Synthetase: Glial Localization in Brain
Authors: Martinez-Hernandez Antonio , Bell Katherine P. , Norenberg Michael D.
Published: October 2006

Light microscopy immunohistochemical techniques were used to examine the distribution of glutamine synthetase in rat brain. Glutamine synthetase was found to be localized in the glial cells. Neuronal cell bodies, endothelial cells, and choroid epithelium contained no enzyme. The findings indicate that glia have a crucial role in glutamic acid, γ-aminobutyric acid, and ammonia metabolism in brain.
Membrane Adenosinetriphosphatase: A Digitalis Receptor?
Authors: Akera Tai
Published: October 2006

The enzyme Na
+
,K
+
-ATPase is a good model for receptor studies because of its known functional correlates. The binding of digitalis to the enzyme observed in vitro satisfied the criteria for receptor binding. Studies of the relationship between the digitalis binding and the drug action reveal an impressive correlation between these events but fail to provide proof of a causal relationship. Studies with other Na
+
,K
+
-ATPase inhibitors and agents that affect transmembrane Na
+
movements (steps that would follow Na
+
,K
+
-ATPase inhibition) provide further supportive evidence that sodium pump inhibition and the resulting enhancement of intracellular Na
+
transients cause the inotropic action of digitalis.
Mitomycins and Porfiromycin: Chemical Mechanism of Activation and Cross-linking of DNA
Authors: Iyer V. N. , Szybalski Waclaw
Published: October 2006

Mitomycins and porfiromycin, generally nonreactive in the natural oxidized state, behave as bifunctional "alkylating" agents upon chemical or enzymatic reduction, followed by spontaneous loss of the tertiary methoxy (hydroxyl) group and formation of an aromatic indole system. Thus activated, mitomycins and porfiromycin react in vitro with purified DNA, linking its complementary strands. A high content of guanine and cytosine favors this cross-linking reaction, which is the basis of the lethal effect in vivo of these antibiotics. The activation and cross-linking reactions are discussed in terms of reactive sites on the mitomycin and DNA molecules.
Dome-Shaped Volcanic Gas Vents in Arizona
Authors: Laidley Richard A. , DuBois Robert L.
Published: October 2006

Dome-shaped fossil gas vents on one of the Hopi Butte diatremes attest to escape of gas during the closing stage of volcanic activity.
Identification of Acetylcholine in Sympathetic Ganglia by Chemical and Physical Methods
Authors: Friesen Abram J. D. , Kemp John W. , Woodbury Dixon M.
Published: October 2006

Extracts of sympathetic ganglionic chains contain a substance which behaves like acetylcholine biologically, chromatographically, and electrophoretically. The melting point of the tetrachloroaurate salt of this substance is identical to that of acetylcholine tetrachloroaurate. No other choline esters have been detected in these extracts. Perfusion of sympathetic ganglia with C
14
-choline indicates that C
14
-acetylcholine is released.
Thermal Inactivation of the Primer in DNA-Dependent Synthesis of RNA in Animal Tissue
Authors: Furth J. J. , Loh Patricia
Published: October 2006

An enzyme preparation obtained from bovine lymphosarcoma tissue catalyzes the DNA-dependent synthesis of RNA. Native DNA is a more efficient primer in the reaction than heat-denatured DNA.
Toxic Effect of
Pseudomonas tabaci
on RNA Metabolism in Tobacco and Its Counteraction by Kinetin
Authors: Lovrekovich L. , Klement Z. , Farkas G. L.
Published: October 2006

Treatment of intact tobacco leaves with toxin-containing culture filtrates of
Pseudomonas tabaci
markedly reduced the ribonucleic acid content of the leaves. The decrease was counteracted by spraying the leaves with 10
-4
M
kinetin. Simultaneously with the decrease in RNA, the ribonuclease activity of extracts from tissues treated with toxin increased. Experiments on the effect of kinetin on the ribonuclease activity of toxin-treated tissues gave no consistent results.
Spectroscopy of Solids in the Far-Infrared
Authors: Tinkham M.
Published: October 2006

The far-infrared spectral region (10-100 cm
-1
) is a fruitful one for studies of solids. The experimental obstacle of weak sources has been partially overcome in recent years by the introduction of very sensitive bolometric radiation detectors cooled by liquid helium to temperatures near 1°K. Used with a mercury arc source and a simple grating monochromator, these detectors have made work in a number of areas of solid-state physics possible. Important examples of such work are, (i) demonstration of the energy gap in superconductors and measurement of gap widths in various metals; (ii) observation of magnetic resonances in ordered magnetic materials, from which precise information about exchange fields and anisotropy energies can be obtained; and (iii) demonstration of the existence of a temperature-dependent low-frequency vibrational mode associated with the Curie-law dielectric constant in certain types of ferroelectric crystals.
Serological Evidence of Arbovirus Infection in the Seminole Indians of Southern Florida
Authors: Work Telford H.
Published: October 2006

A serological survey of the Seminole Indians in south Florida for evidence of exposure to arbovirus infection indicated not only past infection with the recognized North American encephalitis viruses—a high incidence for St. Louis encephalitis—but exposure to a Bunyamwera group agent and to Venezuelan equine encephalitis virus, activity of which had not been previously recognized north of Panama.
Venezuelan Equine Encephalitis Virus in Veracruz, Mexico, and the Use of Hamsters as Sentinels
Authors: Scherer W. F. , Dickerman R. W. , Chia C. Wong , Ventura A. , Moorhouse A. , Geiger R. , Najera A. Diaz
Published: October 2006

Venezuelan equine encephalitis virus was recovered in the state of Veracruz, Mexico, during July and August 1963 from young, weaned hamsters, and from baby mice used as sentinel animals, and from
Culex
mosquitoes. Hamsters of 5 to 10 weeks of age became infected in nature and were nearly as susceptible as suckling mice to subcutaneous inoculation of VEE virus.
Silica Source in Soil Solutions
Authors: Gifford Richard O. , Frugoli Diana M.
Published: October 2006

Heat of solution of silica in soil saturation pastes was calculated from silica solubilities and agreed with values for solid silicic acid. The immediate source of silica in soil solutions apparently is solid silicic acid. The solution of silica from soils exhibited three stages of constant silica solubility.
Genetics of Isoniazid Metabolism in Caucasian, Negro, and Japanese Populations
Authors: Dufour Alfred P. , Knight Ralph A. , William H. Harris
Published: October 2006

Trimodal frequency distributions for isoniazid inactivation were found in Caucasian and Negro populations. The frequency of "rapid" and "slow" alleles in Caucasian and Negro populations was similar and differed from that of a Japanese population.
Ultraviolet Inactivation of Chloroplast Formation in Synchronously Dividing
Euglena gracilis
Authors: Petropulos Stephen F.
Published: October 2006

Ultraviolet inactivation of chloroplast formation was studied in synchronously dividing cultures of
Euglena gracilis
. Sensitivity to sublethal doses given at intervals throughout the cell cycle was greater just before cell division than during division. There was approximately a twofold difference in the dose-response relationships for the periods of high and low sensitivity.
Inhibition of 19
S
Antibody Synthesis by 7
S
Antibody
Authors: Sahiar Khurshed , Schwartz Robert S.
Published: October 2006

A brief course of treatment with 6-mercaptopurine prevented conversion of 19
S
to 7
S
antibodies during the immune response of rabbits to bovine gamma globulin. Specific reactive homologous 7
S
antibodies given intravenously to animals with such incompletely developed humoral reactions led to an abrupt fall in 19
S
antibodies. After a lag period the synthesis of 7
S
antibodies was apparently normal. These results suggest that the concentration of 7
S
antibodies controls the synthesis of 19
S
antibodies.
Congenital Anomalies Induced in Hamster Embryos with H-1 Virus
Authors: Ferm Vergil H. , Kilham Lawrence
Published: October 2006

Intravenous injection of H-1 virus into pregnant hamsters early in gestation produces an embryocidal and teratogenic effect. The congenital malformations, the presence of inclusion bodies in the fetuses, and the fact that the maternal animals are not affected by this virus, are points of similarity to the teratogenic effects of rubella virus and cytomegalic-inclusion disease virus in man.
Intercellular Electrical Coupling at a Forming Membrane Junction in a Dividing Cell
Authors: Ashman R. F. , Kanno Y. , Loewenstein W. R.
Published: October 2006

Ion communication between the halves (blastomere) of a dividing cell (
Asterias forbesi
egg), as determined electrically, diminishes progressively during division as a cell membrane junction forms at the plane of cleavage. Virtually all communication is lost towards the end of division by the time the first intercellular space becomes continuous with the exterior. Resting membrane potentials in both cell halves are essentially equal and constant throughout division.
Oxidation of Extramitochondrial Diphosphopyridine Nucleotide by Various Tissues of the Mouse
Authors: Sacktor Bertram , Dick Arthur R.
Published: October 2006

Exogenous reduced diphosphopyridine nucleotide was not oxidized by mitochondria but by cytoplasmic hydrogen-accepting systems catalyzed by lactic, α-glycerophosphate, and malic dehydrogenases. The three enzymes were found in all tissues of the mouse; the amount of activity of each enzyme differed in the various tissues, however. It is suggested that each tissue has a unique pattern for oxidation of extramitochondrial diphosphopyridine nucleotide.
Stereospecific Polymerization
Authors: Ketley A. D. , Werber F. X.
Published: October 2006

The great flurry of activity which followed the announcement of Ziegler and Natta's initial results has led to the discovery of an enormous number of catalyst systems which are effective in stereospecific polymerization. However, there is little more understanding now than in 1955 of how most of these systems work. Now that the initial excitement has cooled, a larger amount of thoughtful work on the mechanisms of these reactions should appear. As a basis for understanding both the heterogeneous and homogeneous systems, more mechanism studies in organometallic chemistry are urgently needed. More specifically for the heterogeneous catalysts, continued attempts should be made to find better models for the active sites, and new analytical methods should be sought to provide more information concerning the active site itself. In homogeneous systems, greater understanding of the ion pairs, the structure of which is so critical, could be obtained by the preparation and study of nonpolymeric analogues.

In addition to understanding better the catalysts that we already have, we may see in the future the development of new kinds of catalysts. Some of these may be capable of producing polymers in which the units have a more complex code than in those produced by simple stereospecific catalysts. Such catalysts already exist in nature. For example, we now know that the RNA molecule functions as a multifunctional catalyst in peptide syntheses, each sequence of three bases along the backbone corresponding to a particular amino acid. The molecule consequently acts as a catalytic template which defines the order in which these amino acids polymerize into the final peptide. Synthetic RNA's have also been prepared containing only one base such as uracil along the chain.

Since three uracil units correspond to phenylalanine, the polyuracil acts as a template for the formation of a peptide containing only this amino acid. There seems no reason why, ultimately, we should not be able to synthesize polymeric catalysts of this type which can act as templates for the polymerization of specific monomers other than those found in living systems. If a number of systems such as this can be found, we will be on the road to producing catalysts which can not only control the stereochemistry of a polymer chain but also the order in which a group of different monomers can enter into it.
Origin of Ice Ages: Pollen Evidence from Arctic Alaska
Authors: Colinvaux Paul A.
Published: October 2006

Pollen analysis of radiocarbon-dated samples from the arctic coastal plain of Alaska shows that vegetation of 14,000 years ago reflected a climate colder than the present, and that there has been a progressive warming, culminating in the present cold arctic climate. The record indicates that the Arctic Ocean has been covered with ice since the time of the Wisconsin glacial maximum, suggesting that the essential condition of the Ewing and Donn hypothesis for the origin of ice ages, that the Arctic Ocean be ice-free up to 11,000 years ago, cannot be met.
Staphylococcal Alpha-Hemolysin: Detection on the Erythrocyte Membrane by Immunofluorescence
Authors: Klainer Albert S. , Madoff Morton A. , Cooper Louis Z. , Weinstein Louis
Published: October 2006

Purified staphylococcal α-hemolysin (but not the toxoid) was demonstrated on the surface of rabbit and human erythrocytes by immunofluorescence. This occurred during the period of maximal hemolysis and was a transient event. These findings have been analyzed in relation to previous data on the kinetics of leakage of both small and complex molecular constituents of the erythrocyte.
Atrophy of Skeletal Muscle in Chick Embryos Treated with Botulinum Toxin
Authors: Drachman Daniel B.
Published: October 2006

Botulinum toxin was given in large intravenous doses to 7- and 12- day chick embryos. Atrophy of skeletal muscle resulted without significant atrophy of other organs. The histological appearance of muscle was consistent with denervation. The results suggest that neural acetylcholine release may play a significant role in "trophic transmission" from nerve to muscle.
Sleep Pattern of Tooth-Grinding: Its Relationship to Dreaming
Authors: Reding Georges R. , Rubright William C. , Rechtschaffen Allan , Daniels Robert S.
Published: October 2006

Simultaneous recordings of brain waves, eye movements, and masticatory muscle potentials throughout the night demonstrate a temporal relationship between episodes of bruxism (nocturnal grinding of the teeth) and periods of rapid eye movements indicative of dreaming.
Lipopolysaccharide of the Gram-Negative Cell Wall
Authors: Osborn M. J. , Rosen S. M. , Rothfield L. , Zeleznick L. D. , Horecker B. L.
Published: October 2006

The use of mutants of
Salmonella typhimurium
in which biosynthesis of specific lipopolysaccharide precursors is blocked has made possible both biosynthetic studies and structural analyses which provide the basis for the structure of the core polysaccharide shown in Fig. 6. The simplest mutant, which is unable to synthesize UDP-glucose, forms only the backbone structure, containing heptose, phosphate, and keto-deoxyoctonate. To this backbone are attached side chains containing glucose, galactose, and
N
-acetylglucosamine. The resulting core structure is found in the lipopolysaccharide of the rough strain, as well as in that of the GDP-mannose-deficient mutant. In the wild type organism, long O-antigenic chains composed of repeating units containing galactose, mannose, rhamnose, and abequose are linked to the core, perhaps to the
N
-acetylglucosamine residue, as indicated in Fig. 6. The rough phenotype could presumably arise from mutation either at the level of nucleotide sugar synthesis or at some stage in assembly or attachment of the O-antigenic side chains. The pathways of nucleotide sugar synthesis appear to be normal in most rough strains of
S. typhimurium
, a finding which suggests loss of a lipopolysaccharide transferase reaction in these mutants. The site of the enzymatic defect has not yet been established in these cases, but two distinct genetic types of rough mutants have been detected.

It is interesting to speculate about the function of the lipopolysaccharide. The lipopolysaccharide can account for as much as 5 percent of the dry weight of the cell, and its synthesis clearly involves major expenditure both of energy and of material. Yet loss of the antigenic side chains, or even of a major part of the core structure, appears to have little or no effect on the ability of the organism to survive under laboratory conditions, since the rough and mutant strains grow as well as the wild type does. However, only the wild types, possessing the complete antigenic side chains, are pathogenic. It is possible that the lipopolysaccharide is an important factor in aiding the bacterium to evade host defense mechanisms, such as phagocytosis. Such a role is well established for the capsular polysaccharides of the pneumococci. No mutants have thus far been detected which lack the backbone or lipid portions of the lipopolysaccharide. It may be that these parts of the lipopolysaccharide play an essential role in the physiology of the organism.
Nicotinic Acid Biosynthesis: Control by an Enzyme that Competes with a Spontaneous Reaction
Authors: Mehler Alan H. , Yano Kunihiko , May Everette L.
Published: October 2006

Extracts of livers from diabetic rats contain normal amounts of the enzymes needed to convert 3-hydroxyanthranilic acid to nicotinic acid nucleotide. The decreased capacity of diabetic animals to synthesize nicotinic acid is therefore attributed to increased amounts of picolinic carboxylase, which competes for a common intermediate with the spontaneous reaction in which quinolinic acid is formed as a precursor of nicotinic acid. These studies were facilitated by the synthesis of 3-hydroxyanthranilic acid labeled with carbon-14 in positions 3 and 6.
Release of Metaraminol (Aramine) from the Heart by Sympathetic Nerve Stimulation
Authors: Crout J. R. , Alpers H. S. , Tatum E. L. , Shore P. A.
Published: October 2006

Cats were injected intravenously with metaraminol, an amine which depletes norepinephrine from the sympathetic nerve endings; their hearts were then perfused in vitro. Stimulation of the sympathetic nerve supply released metaraminol from the hearts, demonstrating that a synthetic compound can replace norepinephrine and serve as a transmitter at adrenergic nerve endings.
Thysanuran Median Frontal Organ: Its Structural Resemblance to Photoreceptors
Authors: Pipa Rudolph L. , Nishioka Richard S. , Bern Howard A.
Published: October 2006

The median frontal organ of
Thermobia domestica
(Packard) and the median ocellus of
Tricholepidion gertschi
Wygodzinsky were compared with respect to location, innervation, and fine structure. The data suggest that the two organs are homologous. Elementary neurosecretory granules were not found in the median frontal organ, but multivesicular bodies are present in both the frontal organ and ocellus.
Pulse Radiolysis of Potassium Bromide Solutions
Authors: Cercek B. , Ebert M. , Keene J. P. , Swallow A. J.
Published: October 2006

After application of a 2-microsecond pulse of an electron beam to aqueous, aerated, acid solutions of KBr, transient spectra of Br
2
-
and Br
3
-
were observed. The kinetic analysis of the reactions as well as the measured values of G(H
2
O
2
), G(Br
2
), and G(Br
3
-
) revealed a reaction mechanism differing from the one which is accepted for radiolysis at low intensity
Hydrogen Atom Thermal Parameters
Authors: Jensen L. H. , Sundaralingam M.
Published: October 2006

Isotropic hydrogen atom thermal parameters for
N,N
′-hexamethylenebispropionamide have been determined. They show a definite trend and vary from approximately the same as the mean thermal parameters for atoms other than hydrogen near the center of the molecule to appreciably greater for atoms near the end. The indicated trend for this compound, along with other results, provides the basis for a possible explanation of the anomolous values that have been obtained for hydrogen atom thermal parameters.
Acid Phosphatases of Human Red Cells: Predicted Phenotype Conforms to a Genetic Hypothesis
Authors: Lai L. , Nevo Sarah , Steinberg A. G.
Published: October 2006

Analysis of data from 80 families and 369 unrelated individuals confirms the hypothesis that human red cell acid phosphatase phenotypes are determined by three codominant alleles at a single autosomal locus. Further confirmation is afforded by the finding of the predicted sixth phenotype.
Pulmonary Alveolar Cell Inclusions: Their Development in the Rat
Authors: Buckingham Sue , McNary William F. , Sommers Sheldon C.
Published: October 2006

Cytoplasmic inclusions in the special pulmonary alveolar cells of adult, newborn, and fetal rats were investigated by electron microscopy and histochemistry, and lung extracts were analyzed for surface-tension activity. The inclusions were positive in the periodic acid-Schiff test after digestion with diastase and were not stained with toluidine blue; they formed myelin figures and possessed alkaline phosphatase activity. Both the typical surface tension activity and the inclusions developed 2 days before birth. These properties differentiated the inclusions from mitochondria.
Simultaneous Recordings of Scalp and Epidural Somatosensory-Evoked Responses in Man
Authors: Domino Edward F. , Matsuoka Shigeaki , Waltz Joseph , Cooper Irving
Published: October 2006

The calvarium and scalp markedly attenuate the amplitude, but do not alter the latency or frequency, of somatosensory responses evoked by electrical stimulation of the contralateral median nerve in man. With scalp electrodes no significant potentials are obtained that are not also present in the epidural recordings when proper averaging techniques are used. The somatosensory-evoked response recorded with scalp electrodes in man appears to be the result of brain activity.
Intracellular Perfusion of Chilean Giant Squid Axons
Authors: Tasaki Ichiji , Luxoro Mario
Published: October 2006

Axons of the Chilean giant squid were subjected to continuous intracellular perfusion with either potassium- or sodium-rich salt solutions. In axons immersed in natural sea water and internally perfused with potassium glutamate solution, action potentials which exceeded 160 millivolts were often observed. The resting potential did not vary appreciably with the internal concentration of potassium glutamate. With perfusing solutions containing sodium aspartate or sodium glutamate, action potentials were observed which exceeded the value calculated from the Nernst equation applied to sodium-ion activity. Nervous conduction could be maintained more than 1 hour with equal concentrations of sodium inside and outside the axon.
Bacterial Mutant with Impaired Potassium Transport and Methionine Biosynthesis
Authors: Damadian R. , Solomon A. K.
Published: October 2006

A mutant of
Escherichia coli
has been isolated in which potassium transport and methionine biosynthesis are both impaired. Studies on the nutritional requirements of this organism suggest that the cystathionine cleavage enzyme is impaired. Experiments in low-potassium medium showed that the mutant was unable to maintain the usual high cell potassium concentration. Studies that were made of the mutant and its revertants suggested that a single genetic event was responsible.
Experimenter Bias in Hypnotist Performance
Authors: Troffer Suzanne A. , Tart Charles T.
Published: October 2006

Eight hypnotist-experimenters administered a standardized suggestibility test to subjects under two separate experimental conditions. The experimenters understood the problem of experimenter bias, knew that they were being checked, and felt that they had treated both groups alike, yet judges were able to tell under which condition the subjects were tested by listening to the performances of the experimenters.