bluuebunny/crossref_metadata_2025 huggingface dataset:
Sleep: Suppression of Rapid Eye Movement Phase in the Cat after Electroconvulsive Shock
Authors: Cohen Harry B. , Dement William C.
Published: October 2006

Electroconvulsive shock, administered for 5 to 7 days, reduced the daily rapid eye movement sleep time of seven cats to as little as 28 percent of base line levels. After day 4, eye movements during periods of cortical activation without tonic electromyographic activity were greatly reduced. Although partially deprived of rapid eye movements for as long as 7 days, the cats showed no compensatory rise in rapid eye movement time during the recovery period, but controls equally deprived gave significant rebounds. Rapid eye movement time of anesthetized cats was not affected by current that usually produces convulsions; it was lowered in animals convulsed with metrazol, but the same dosage of this drug, administered so as to avoid convulsions, had little effect. It appears that some aspect of the convulsion is responsible for lowering the rapid eye movement time.
Manganese Nodules: Thorium-230: Protactinium-231 Ratios
Authors: Sackett William M.
Published: October 2006

The Th
230
: Pa
231
activity ratio in 7 of 11 manganese nodules is less than 10.8, the theoretical production ratio of activities in the ocean. This finding indicates differential accumulation of these nuclides in authigenic deposits of manganese-iron oxide.
Lethal Effects of Synthetic Juvenile Hormone on Larvae of the Yellow Fever Mosquito,
Aedes aegypti
Authors: Spielman Andrew , Williams Carroll M.
Published: October 2006

Emergence of adult mosquitoes is blocked after the addition of 1 part of crude synthetic juvenile hormone to 100,000 parts water. Development is arrested at stages ranging from pupae to fully formed pharate adults incapable of escaping from the pupal exuvium. Fourth-stage larvae just prior to metamorphosis are most sensitive: 40 percent were killed after being exposed for 1 day to 1 part juvenile hormone in 2 million parts water. The active material also inhibits the hatching of mosquito eggs.
Monkeys Reared in Isolation with Pictures as Visual Input: Evidence for an Innate Releasing Mechanism
Authors: Sackett Gene P.
Published: October 2006

Monkeys reared in isolation from birth to 9 months received varied visual input solely from colored slides of monkeys in various activities and from nonmonkey pictures. Exploration, play, vocalization, and disturbance occurred most frequently with pictures of monkeys threatening and pictures of infants. From 2.5 to 4 months threat pictures yielded a high frequency of disturbance. Lever-touching to turn threat pictures on was very low during this period. Pictures of infants and of threat thus appear to have prepotent general activating properties, while pictures of threat appear to release a developmentally determined, inborn fear response.
Interaction of the Water-Soluble Carcinogen 4-Nitroquinoline
N
-Oxide with DNA
Authors: Malkin Martin F. , Zahalsky Arthur C.
Published: October 2006

Thin-layer chromatography revealed that 4-nitroquinoline
N
-oxide interacts with native DNA, but not with denatured DNA's or the following macromolecules and nucleic acid derivatives: soluble RNA from
Escherichia coli
and from yeast, polyguanylate-cytidylate, and precursors of DNA and RNA. Polydeoxyadenylate-thymidylate, polyadenylate, and histone interacted to a lesser degree than native DNA's did. That magnesium ion, sodium ion, and proflavine did not interfere with interaction of carcinogen and DNA suggests that this interaction is not an intercalation. Interaction of 4-nitroquinoline
N
-oxide with DNA may be related to its carcinogenicity.
Structural Evidence for Induced Fit as a Mechanism for Antibody-Antigen Recognition
Authors: Rini James M. , Schulze-Gahmen Ursula , Wilson Ian A.
Published: October 2006

The three-dimensional structure of a specific antibody (Fab 17/9) to a peptide immunogen from influenza virus hemagglutinin [HA1(75-110)] and two independent crystal complexes of this antibody with bound peptide (Tyr
P100
-Leu
P108
) have been determined by x-ray crystallographic techniques at 2.0 Å, 2.9 Å, and 3.1 Å resolution, respectively. The nonapeptide antigen assumes a type I β turn in the antibody combining site and interacts primarily with the Fab hypervariable loops L3, H2, and H3. Comparison of the bound and unbound Fab structures shows that a major rearrangement in the H3 loop accompanies antigen binding. This conformational change results in the creation of a binding pocket for the β turn of the peptide, allowing Tyr
P105
to be accommodated. The conformation of the peptide bound to the antibody shows similarity to its cognate sequence in the HA1, suggesting a possible mechanism for the cross-reactivity of this Fab with monomeric hemagglutinin. The structures of the free and antigen bound antibodies demonstrate the flexibility of the antibody combining site and provide an example of induced fit as a mechanism for antibody-antigen recognition.
Bacterial Growth Rate in the Sea: Direct Analysis by Thymidine Autoradiography
Authors: Brock Thomas D.
Published: October 2006

Autoradiography with tritiated thymidine was used to study microbial growth directly in nature. The epiphyte
Leucothrix mucor
was used since it is a large filamentous bacterium with a characteristic morphology making it recognizable in natural collections. The technique was developed initially with pure cultures. The relation between growth rate and the rate of accumulation of radioactive cells permitted derivation of a constant for use in calculating growth rate in natural material and in two-membered cultures of
L. mucor
growing epiphytically on pure cultures of marine algae. The growth rate (generation time) in two-membered cultures with the red alga
Antithamnion sarniense
was 94 minutes under the conditions used. In nature the growth rate of a sample from Iceland was 685 minutes; that of a sample from Long Island Sound was 660 minutes. There was no evidence of preferential growth in the basal portion of bacterial filaments nearest the algal surface. However, filamentous growth in nature, but not in pure or two-membered culture, was nonrandom, growth being clustered in some regions.
Erythrocyte Chimerism after Injection of Spleen Cells into Anemic Mice of the W-Series
Authors: Seller Mary J.
Published: October 2006

Anemic mice (W
v
W
v
) when injected at birth with a mixture of isologous (genotype W
v
w) and homologous spleen cells, showed an improvement in their peripheral blood picture when adult. Red blood counts, red cell size, and electrophoresis of the hemoglobins indicated that, in some cases, the homologous tissue had become implanted and, in others, the isologous tissue was functioning.
Abductin: A Rubber-Like Protein from the Internal Triangular Hinge Ligament of
Pecten
Authors: Kelly Robert E. , Rice Robert V.
Published: October 2006

The rubber-like internal triangular hinge ligament from
Pecten
was studied by light and electron microscopy, x-ray diffraction, and chemical analysis. The ligament is composed of an amorphous protein, abductin. In physical properties abductin is similar to elastin and resilin but distinct by amino acid analysis. It is characterized by high concentrations of glycine and methionine.
The Ecological Significance of Sexual Dimorphism in Size in the Lizard
Anolis conspersus
Authors: Schoener Thomas W.
Published: October 2006

Adult males of
Anolis conspersus
capture prey of significantly larger size and occupy perches of significantly greater diameter and height than do adult females; similarly, these three dimensions of the niche are significantly larger for adult females than for juveniles. Adult males on the average eat a smaller number of prey, and the range in size of prey is larger. The relationship between the average length of the prey and that of the predator is linear when the predator size is above 36 millimeters, but becomes asymptotic when it is below that value. Subadult males as long as adult females eat significantly larger food than do the latter, but only in the larger lizards is this correlated with a relatively larger head.
Anolis conspersus
selects prey from a wide range of taxa and shows no obvious intraspecific specialization not connected to differences in microhabitat and prey size. The efficiency of this system for solitary species is pointed out.
Splashing of a Water Drop
Authors: Hobbs P. V. , Kezweeny A. J.
Published: October 2006

Measurements have been made of the number of spray droplets produced by the impact of a water drop on water, and of the charge to mass ratio for these droplets. For a drop 3 millimeters in diameter, the number of spray droplets increases linearly with the fall-distance of the drop over the range 10 to 200 centimeters. When the drop falls 100 centimeters, about 25 spray droplets are produced. The majority of the droplets carry a negative charge, and the ratio of the charge to the mass varies from 4 to 28 electrostatic units per gram.
Cosmological Element Production
Authors: Wagoner Robert V.
Published: October 2006

Two recent observations appear to have provided critical information about the past history of the universe. The thermal character of the microwave background radiation suggests that the universe has expanded from a state of high temperature and density, and places constraints on such a big-bang cosmology. The observations of very weak helium lines in the spectra of certain stars in the halo of our galaxy are possibly due to a low primeval abundance of this element. However, the simplest model of a big-bang cosmology leads to much higher helium abundances, such as are observed in the solar system and in many stars. The production of helium can be reduced either by altering the early expansion rate or by introducing degenerate electron neutrinos. Observations of interstellar and intergalactic deuterium and He
4
, and possibly even He
3
and Li
7
, are needed to test the various models.
Metastable Superheated Ice in Liquid-Water Inclusions under High Negative Pressure
Authors: Roedder Edwin
Published: October 2006

In some microscopic inclusions (consisting of aqueous liquid and vapor) in minerals, freezing eliminates the vapor phase because of greater volume occupied by the resulting ice. When vapor fails to nucleate again on partial melting, the resulting negative pressure (hydrostatic tension) inside the inclusions permits the existence of ice I crystals under reversible, metastable equilibrium, at temperatures as high as +6.5°C and negative pressures possibly exceeding 1000 bars.
Alga-Like Fossils from the Early Precambrian of South Africa
Authors: Schopf J. William , Barghoorn Elso S.
Published: October 2006

Micropaleontological studies of carbonaceous chert from the Fig Tree Series of South Africa (> 3.1 × 10
9
years old) revealed the presence of spheroidal microfossils, here designated
Archaeosphaeroides barbertonensis
, interpreted as probably representing the remnants of unicellular alga-like organisms. The presumed photosynthetic nature of these primitive microorganisms seems corroborated by organic geochemical and carbon isotopic studies of the Fig Tree organic matter, and is consistent with the geologically and mineralogically indicated Early Precambrian environment. These alga-like spheroids, together with a bacterium-like organism previously described from the Fig Tree chert, are the oldest fossil organisms now known.
Regulation of Body Temperature in the Blue-Tongued Lizard
Authors: Hammel H. T. , Caldwell Fred T. , Abrams Robert M.
Published: October 2006

Lizards (
Tiliqua scincoides
) regulated their internal body temperature by moving back and forth between 15° and 45°C environments to maintain colonic and brain temperatures between 30° and 37°C. A pair of thermodes were implanted across the preoptic region of the brain stem, and a reentrant tube for a thermocouple was implanted in the brain stem. Heating the brain stem to 41°C activated the exit response from the hot environment at a colonic temperature 1° to 2°C lower than normal, whereas cooling the brain stem to 25°C delayed the exit from the hot environment until the colonic temperature was 1° to 2°C higher than normal. The behavioral thermoregulatory responses of this ectotherm appear to be activated by a combination of hypothalamic and other body temperatures.
Stimulus Preferences and Imprinting
Authors: Klopfer Peter H.
Published: October 2006

Pekin ducklings were tested with respect to their preference for approaching one of two simultaneously presented, rotating, silent duck decoys, painted in a variety of colors or patterns. Some of the ducklings had not been given any previous visual experience other than that gained in a 20-minute introduction to the empty apparatus; others had previously been given the opportunity to follow one particular decoy for 20 minutes. The decoys could be grouped into three categories: those in the first category were treated as equivalent, that is, so long as the duckling had followed one of these models it would approach either. The decoys of the second category were ones to which "imprinting" occurred, that is, the ducklings showed a decided preference for the model they had originally followed, whichever it was. The third category included models, one of which was always preferred, though the controls showed no such preference. The effects of the imprinting procedure vary with the stimuli presented.
Radiation Damage, at High Temperatures
Authors: Weir J. R.
Published: October 2006

The successful development of nuclear power reactors that are economically competitive with other sources of energy has led us to believe that more economical reactors will be developed. But, in developing the next generation of reactors, a new set of problems must be overcome. One of the most important of these is that of the embrittlement of the structural materials at high temperatures as a result of the intense neutron fields in these advanced systems.

The radiation-induced embrittlement at high temperatures is probably associated with helium produced in the materials due to (
n
,α) reactions with the metal, and in some alloys radiation-induced precipitation of compounds within the alloy may also play a role. We believe that the most serious long-term problem is the generation of helium. Our current understanding of the mechanism by which this radiation damage is produced has allowed us to effect some improvement in the behavior of conventionally produced structural alloys, through minor modifications of the normal working and annealing processes used in their manufacture. However, we may find that new alloys will have to be developed to withstand the service conditions in future nuclear power reactors.
Agglutinating Specificity for LW Factor in Guinea Pig and Rabbit Anti-Rh Serums
Authors: Levine Philip , Celano M. J.
Published: October 2006

Serums produced in guinea pigs or rabbits inoculated with monkey (rhesus or baboon) or human red cells contain the same high-incidence agglutinating activity found in human anti-LW serums. After one absorption with LW-negative blood cells. anti-LW specificity was observed with stronger reactions on Rh-positive than Rh-negative cells. The 85-percent specificity was obtained after complete absorption with Rh-negative blood.
Cell Aggregation: Its Enhancement by a Supernatant from Cultures of Homologous Cells
Authors: Lilien Jack E. , Moscona A. A.
Published: October 2006

A supernatant medium has been prepared from living embryonic neural retina cells which specifically promotes their histogenetic aggregation. Its function is dependent upon at least two experimentally separable steps: selective uptake and functional utilization.
Receptive Fields in the Cat Retina: A New Type
Authors: Rodieck R. W.
Published: October 2006

A new type of receptive field of cat retinal ganglion cells is described and termed the "suppressed-by-contrast" type. The firing rate of these cells is suppressed by a variety of visual stimuli. However, it has not been possible to find a stimulus that increases the firing rate above the maintained level.
Virus-Like Particles in Normal and Tumorous Tissues of
Drosophila
Authors: Akai Hiromu , Gateff Elisabeth , Davis Lowell E. , Schneiderman Howard A.
Published: October 2006

A new virus-like particle has been found in
Drosophila
. Thus far it has been detected only in electron micrographs of certain cells capable of division, such as those in larval imaginal disks, cell lines derived from imaginal disks, cells from a genetically controlled brain tumor, and adult gut cells. It appears to be slightly elliptical in shape, about 37 millimicrons by 45 millimicrons, and occurs in both the nucleus and cytoplasm. From the evidence it is suggested that the particle is a new virus.
Photosynthetic Utilization of Internal Carbon Dioxide by Hollow-Stemmed Plants
Authors: Billings W. D. , Godfrey P. J.
Published: October 2006

The hollow stems of wet-meadow and bog plants often contain relatively large amounts of carbon dioxide. The internal carbon dioxide apparently originates from respiration of root and stem cells. Some of this carbon dioxide is fixed photosynthetically by stem tissues and is thus recycled within the plant. Such internal stem photosynthesis would be advantageous, particularly in the early stages of growth in cold, wet, high-altitude environments.
Reversal Learning and Forgetting in Bird and Fish
Authors: Gonzalez R. C. , Behrend Erika R. , Bitterman M. E.
Published: October 2006

Pigeons and goldfish were trained in red-green discrimination in daily sessions, with the rewarded color changed every 2 days. Improvement in the performance of the pigeons could be traced to decrements in retention from each day to the next. The goldfish showed no improvement and no decrements in retention. The results suggest that progressive improvement in habit reversal is a product of proactive interference, and that the absence of improvement in the fish is due, not to the lack of some higher-order process which operates to produce improvement in higher vertebrates, but to a difference in learning-retention mechanisms.
Chemical Communication in Social Behavior of a Fish, the Yellow Bullhead (
Ictalurus natalis
)
Authors: Todd John H. , Atema Jelle , Bardach John E.
Published: October 2006

Studies of behavior in yellow bullheads showed that they recognized individuals of their own species by means of pheromones. After training by reward and punishment, blinded bullheads were able to discriminate between the odors of two donor fish, but they lost this ability when deprived of their sense of smell. The main source of the intraspecific chemical stimuli involved in recognition is the mucus. A change in status after fighting was chemically communicated to other bullheads.
Atmospheric Burnup of a Plutonium-238 Generator
Authors: Krey P. W.
Published: October 2006

The stratospheric inventory of the plutonium-238 resulting from the disintegration of a nuclear auxiliary power generator (SNAP-9A) in early 1966 accounts for essentially all the plutonium present in the original generator that reentered the atmosphere. Consequently, the pyrophoric
238
Pu must have completely burned up during reentry and ablated into small particles. The arithmetic mean of the distribution of the
238
Pu particle size was estimated to be 10 millimicrons, which confirms this conclusion.
Calcitonin from Ultimobranchial Glands of Dogfish and Chickens
Authors: Copp D. H. , Cockcroft D. W. , Kueh Yankoon
Published: October 2006

Acid extracts of thyroid glands from a small shark
Squalus suckleyi
and domestic fowl
Gallus domestica
contained no detectable calcitonin activity, while very potent hypocalcemic responses were obtained in rats with similar extracts from the ultimobranchial glands of these two species. The calcitonin concentration was 4 to 40 times that present in hog thyroid, which, as in most other mammals, contains ultimobranchial tissue. The evidence suggests that calcitonin is a fundamental calcium-regulating hormone present in all higher vertebrates and that it is an ultimobranchial rather than a thyroid hormone. It also indicates an important and hitherto unrecognized function for the ultimobranchial glands.
Stimulus Generalization as Signal Detection in Pigeons
Authors: Blough Donald S.
Published: October 2006

Pigeons that were reinforced for pecking at a single-wavelength responded to nearby wavelengths with lower rates. Response rates indicated the pigeons' certainty that the reinforced stimulus was present. The ratings yielded receiver operating characteristic functions that approximated straight lines on a double probability plot.
Life at High Temperatures
Authors: Brock Thomas D.
Published: October 2006

The time is now ripe for a concerted attack on the evolutionary, ecological, and molecular aspects of life at high temperatures. Hot springs provide nearly ideal ecosystems for such study, since they are natural environments of great antiquity and relative constancy, where organisms have evolved to meet the environmental challenges of high temperatures. Even from our present limited knowledge, we can draw a number of conclusions.
"Intrinsic" Immunological Tolerance in Allophenic Mice
Authors: Mintz Beatrice , Silvers Willys K.
Published: October 2006

Mice experimentally derived from pairs of conjoined, undifferentiated, cleavage-stage embryos of different histocompatibility genotypes can retain cells of each strain, which still produce their characteristic antigenic products. The animals are permanently tolerant of cells of both original types, remain free of runt disease, and display a normal and specific immune response to introduction of a foreign antigen. Absence of autoimmunity in development of ordinary animals is explainable by the "intrinsic" kind of tolerance found here.
Experimental Deprivation and Later Behavior
Authors: Fuller John L.
Published: October 2006

Our experiments on the effects of experiential deprivation upon later behavior of dogs have dealt with four major areas. The programming of life histories has involved the scheduling of breaks in isolation and the introduction of specific stimuli to isolation cages. Biweekly breaks, of less than 10 minutes each, largely counteract the effects of isolation. An opportunity for the animal to look out of the isolation cage has some counteracting effect, but the presence of playthings or rearing with a companion does not.
Selective Phagocytosis: A New Concept in Protein Catabolism
Authors: Gans H. , Subramanian V. , Tan B. H.
Published: October 2006

The clearance of different metabolic products derived from two plasma proteins, prothrombin and fibrinogen, was studied with the aid of the isolated, perfused rat liver. Active thrombin and fibrin were rapidly cleared by the Kupffer cells. Inactive thrombin and a partially degraded fibrin molecule were also cleared but at much slower rates. This difference in clearance rates suggests the presence of a high degree of selectivity in the clearance of altered plasma proteins.
The Biology of Isolated Chromatin
Authors: Bonner James , Dahmus Michael E. , Fambrough Douglas , Huang Ru-chih C. , Marushige Keiji , Tuan Dorothy Y. H.
Published: October 2006

The isolated chromatin of higher organisms possesses several properties characteristic of the same chromatin in life. These include the presence of histone bound to DNA, the state of repression of the genetic material, and the ability to serve as template for the readout of the derepressed portion of the genome by RNA polymerase. The important respect in which isolated chromatin differs from the material in vivo, fragmentation of DNA into pieces shorter (5 × 10
6
to 20 × 10
6
molecular weight) than the original, does not appear to importantly alter such transcription. The study of isolated chromatin has already revealed the material basis of the restriction of template activity; it is the formation of a complex between histone and DNA. Chromatin isolated by the methods now available, together with the basis provided by our present knowledge of chromatin biochemistry and biophysics, should make possible and indeed assure rapid increase in our knowledge of chromosomal structure and of all aspects of the control of gene activity and hence of developmental processes.
Atypical Cholinesterase Gene
E
1

a

: Rarity in Negroes and Most Orientals
Authors: Motulsky Arno G. , Morrow A.
Published: October 2006

Development of a rapid screening test for atypical cholinesterase in serum enabled large-scale surveys of populations. The frequency of the heterozygous trait among Greeks, Yugoslavs, and East Indians was similar to that among United States Caucasians (2.8 to 3.3 percent). In trait frequency, U.S. Negroes were intermediate (1.05 percent) between Congolese Africans (0.29 percent) and U.S. Whites (3.3 percent). The gene was absent from or very rare in populations originating in East Asia (Taiwanese, Japanese, Filipinos, and Eskimos). Prolonged apnea during anesthesia from administration of succinylcholine, caused by homozygosity for this gene, is expected to be extremely rare among populations of Negroes and East Asians.
Sex Attractant of Sugar Beet Wireworm: Identification and Biological Activity
Authors: Jacobson Martin , Lilly Charles E. , Harding Charles
Published: October 2006

The sex attractant produced by adult females of the sugar beet wireworm,
Limonius californicus
(Mannerheim) has been isolated and identified as valeric acid. In the laboratory, male wireworm beetles are repelled by the pure attractant but are drawn with intense sexual excitement to its dilute solutions; in the field, male beetles are lured from a distance of 12 meters. The pheromone occurs in unusually large amounts in the female's body.
Parametric Pumping: Separation of Mixture of Toluene and
n
-Heptane
Authors: Wilhelm Richard H. , Sweed Norman H.
Published: October 2006

Parametric pumping, a dynamic separation technique, comprises alternating axial displacement of a fluid mixture in a column of adsorptive particles upon which a synchronous cycling temperature is imposed. With direct coupling, separations of 10
5
:1 between column ends have been obtained, with indications of great potential for further separation. A mathematical model and its solution describe the behavior of the system.
Cyclic Changes in Enzyme Activity in Synchronized Mammalian Cell Cultures
Authors: Klevecz Robert R. , Ruddle Frank H.
Published: October 2006

Activity of the enzymes glucose-6-phosphate dehydrogenase and lactate dehydrogenase increases intermittently in synchronized cultures of Chinese hamster cells. During G
1
phase (3 hours after mitosis), midway through S phase (7 hours after mitosis) and again in late S phase (10 hours after mitosis), rapid increases in activity were observed and correlated with a net increase in cell size and total protein. The evidence suggests that this is a general phenomenon which affects a whole population of proteins and may be the expression of an endogenous cellular rhythm.
Chaetopterus
Photoprotein: Crystallization and Cofactor Requirements for Bioluminescence
Authors: Shimomura Osamu , Johnson Frank H.
Published: October 2006

The
Chaetopterus
photoprotein has been isolated in an amorphous form (molecular weight, 120,000) which in (NH
4
)
2
SO
4
solution converts to a crystalline form (molecular weight, 184,000) having the same specific light-emitting activity; quantum yields are 0.0093 and 0.0143, respectively. Two new cofactor requirements have been separated from impure extracts: a macromolecule resembling a nucleoprotein, and a lipid-like substance.
Neoplastic Transformation of Hamster Astrocytes in vitro by Simian Virus 40 and Polyoma Virus
Authors: Shein Harvey M.
Published: October 2006

Astrocytes in cultures of brain cells from fetal or newborn hamsters undergo neoplastic transformation after infection with simian virus 40 or polyoma virus. Subcutaneous or intracerebral inoculation of the transformed brain cells into newborn or adult hamsters produces progressively enlarging astrocytomas at the sites of injection. Astrocytomas produced by polyomatransformed cell lines are histologically better differentiated, but grow more rapidly and metastasize more frequently, than astrocytomas produced by cell lines transformed by simian virus 40. These observations make available in vitro models of virus-induced oncogenesis in astrocytes and provide simple techniques for obtaining astrocytoma cell lines suitable for screening studies of chemical agents effective against astrocytomas.
Amoebic Meningoencephalitis: Sixteen Fatalities
Authors: Červa L. , Novǎk K.
Published: October 2006

The parasitologic examination of pathologic brain tissue from 16 cases of acute purulent meningoencephalitis occurring between 1962 and 1965 in northern Bohemia disclosed massive infection of the central nervous system by amoebas of the limax type. The common source was an indoor swimming pool.
Precession of the Earth as the Cause of Geomagnetism
Authors: Malkus W. V. R.
Published: October 2006

I have proposed that the precessional torques acting on the earth can sustain a turbulent hydromagnetic flow in the molten core. A gross balance of the Coriolis force, the Lorentz force, and the precessional force in the core fluid provided estimates of the fluid velocity and the interior magnetic field characteristic of such flow. Then these numbers and a balance of the processes responsible for the decay and regeneration of the magnetic field provided an estimate of the magnetic field external to the core. This external field is in keeping with the observations, but its value is dependent upon the speculative value for the electrical conductivity of core material. The proposal that turbulent flow due to precession can occur in the core was tested in a study of nonmagnetic laboratory flows induced by the steady precession of fluid-filled rotating spheroids. It was found that these flows exhibit both small wavelike instabilities and violent finite-amplitude instability to turbulent motion above critical values of the precession rate. The observed critical parameters indicate that a laminar flow in the core, due to the earth's precession, would have weak hydrodynamic instabilities at most, but that finite-amplitude hydromagnetic instability could lead to fully turbulent flow.
Long-Distance Dispersal of Seeds by Retention in Digestive Tract of Birds
Authors: Proctor Vernon W.
Published: October 2006

Viable seeds of
Celtis
,
Convolvulus
,
Malva
, and
Rhus
were regurgitated from the digestive tract of killdeer (
Charadrius vociferus
) after 160, 144, 152, and 340 hours, respectively; seeds were recovered in the same way, after long-time retention, from least sandpipers (
Erolia minutilla
). Most other birds do not retain seeds as long. There is evidence that seeds of many species can remain viable in the intestinal tract of some shorebirds long enough to be transported several thousand miles.
Tritium Movement in Soil of Tropical Rain Forest
Authors: Kline J. R. , Jordan C. F.
Published: October 2006

Tritiated water applied to the surface of soil in a tropical rain forest was found in free water of the litter and top 18 centimeters of soil as long as 7 months after the application. Plant roots, even in the high-rainfall environment of a tropical rain forest, therefore are exposed to tritiated water for considerable periods of time after release.
Peruvian Desert Mice: Water Independence, Competition, and Breeding Cycle near the Equator
Authors: Koford Carl B.
Published: October 2006

The native mouse of the Peruvian coastal desert, near latitude 6°S, can survive on dry seed without drinking water, it bears young in winter, and it burrows in sand. House mice (which abound in other adjoining deserts) also tolerate dehydration, and in some areas may displace the native mice.
Cystathionine Synthase in Tissue Culture Derived from Human Skin: Enzyme Defect in Homocystinuria
Authors: Uhlendorf B. William , Mudd S. Harvey
Published: October 2006

Fibroblasts derived from normal human skin and from cells in amniotic fluid and grown in tissue culture have cystathionine synthase activity. Skin from homocystinuric patients gives rise to fibroblast lines with normal activities of methionine-activating enzyme, but with very low or undetectable cystathionine synthase activity. Thus, the enzyme lesion in homocystinuria is demonstrable in readily available human cells. Neither cystathionine synthase nor methionine-activating enzyme could be detected in intact normal skin.
Research and Development at the University
Authors: Kash Don E.
Published: October 2006

In summary then, the growing call from government for the universities to do applied research in the civilian sector has many disturbing elements. It asks the university to provide more policy advice. In addition, it calls upon the university to become an advocate for that policy research. One can hardly be a part of the university tradition in this country without being initially appalled. Yet the demand is clearly there and it is hard to disagree with Perkins when he says, "The University—as the most sophisticated and, let us hope, independent agency now at work advancing, transmitting and applying knowledge—has come too far to retreat before what may be its finest hour".
Alcohol Preference in the Rat: Reduction Following Depletion of Brain Serotonin
Authors: Myers Robert D. , Veale Warren L.
Published: October 2006

Preference for ethyl alcohol was significantly reduced or totally abolished in rats given orally
p
-chlorophenylalanine, a tryptophan hydroxylase inhibitor that selectively depletes brain serotonin. Some aversion to alcohol was observed while
p
-chlorophenylalanine was administered, but the rats' rejection of alcohol was even more marked after the drug was discontinued. Oral administration of α-methyl-
p
-tyrosine, a tyrosine hydroxylase inhibitor that depletes brain catecholamines, slightly reduced selection of alcohol, but preference returned to normal as soon as α-methyl-
p
-tyrosine was terminated.
Aspirin: Action on Receptor in the Tooth
Authors: Scott Donald
Published: October 2006

Impulse frequency recorded from dentinal receptors in the cat's tooth provided an indication of sensory excitation. Topical application of aspirin to the dentin promptly inhibited both steady-state discharge and response to a brief heat stimulus. When the drug was washed out, the initial excitability was restored in 15 minutes.
Bioluminescence:
p
H Activity Profiles of Related Luciferase Fractions
Authors: Krieger Neil , Hastings J. W.
Published: October 2006

The 27,000g supernatant from crude extracts of the dinoflagellate Gonyaulax can be fractionated into two components having luciferase activity that differ both in molecular weight (35,000 and 150,000) and in
p
H activity profile. The smaller component has activity over a broad range from
p
H 5 to 9, while the larger one is active only in the acid region. This clarifies the previous ambiguity in the literature regarding the optimum
p
H for the assay of luciferase.
Radiocarbon: Analysis of Inorganic Carbon of Fossil Bone and Enamel
Authors: Haynes Vance
Published: October 2006

Carbon dioxide from calcium carbonate in fossil bone can be selectively separated from carbon dioxide in bone apatite by hydrolyzing the sample first in acetic acid and then in hydrochloric acid. Radiocarbon analyses of the inorganic carbon dioxide in three samples of known age clearly show calcium carbonate in fossil bone to be secondary and the carbonate of bone apatite to be indigenous and suitable for dating in some cases. Agreement between dates on collagen-bone apatite pairs increases the level of confidence.
Interferon: Protection of Cells Infected with an Intracellular Protozoan (
Toxoplasma gondii
)
Authors: Remington Jack S. , Merigan Thomas C.
Published: October 2006

Chick and mouse cell monolayers treated with interferon were significantly protected from destruction by toxoplasma. The results suggest that fewer numbers of organisms were released from interferon-treated cells. Interferons were uniformly more active in a viral assay than in a toxoplasma assay, and they had the same properties in both assays. The data suggest that interferon activity may be directed against organisms phylogenetically higher than viruses.
Oncogenicity by Methyl Methanesulfonate in Male RF Mice
Authors: Clapp N. K. , Craig A. W. , Toya R. E.
Published: October 2006

The incidences of lung tumors and thymic lymphomas were increased in young adult male RF mice receiving 30 milligrams of methyl methanesulfonate per kilogram of body weight daily in the drinking water throughout life. Differences in oncogenicity between treatment with methyl methanesulfonate and with dimethylnitrosamine or diethylnitrosamine suggest a qualitative difference between the site (or sites) of alkylation by methyl methanesulfonate and by dimethylnitrosamine or diethylnitrosamine within the nucleic acids.
Neuronal Perikarya of Rat Brain Isolated by Zonal Centrifugation
Authors: Flangas Arthur L. , Bowman Robert E.
Published: October 2006

Cerebral cortex and hippocampus of rat were disrupted in a specially designed tissue-press and prepared as a 2 percent suspension in 10 percent buffered Ficoll medium and fractionated by density-gradient centrifugation in the B XIV zonal rotor. The suspension was injected into a buffered 30 percent Ficoll, 58 percent sucrose discontinuous gradient previously loaded in the B XIV zonal rotor spinning at 3500 revolutions per minute. Intact neuronal perikarya were recovered as a discrete band in the dense sucrose zone of the gradient after centrifugation at 35,000 revolutions per minute for 45 minutes.
Taste-Modifying Protein from Miracle Fruit
Authors: Kurihara Kenzo , Beidler Lloyd M.
Published: October 2006

The active principle of miracle fruit (
Synsepalum dulcificum
) is a basic glycoprotein with a probable molecular weight of 44,000. Application of the protein to the tongue modifies the taste so that one tastes sour substances as sweet.
The Role of Solvent Viscosity in the Dynamics of Protein Conformational Changes
Authors: Ansari Anjum , Jones Colleen M. , Henry Eric R. , Hofrichter James , Eaton William A.
Published: October 2006

Nanosecond lasers were used to measure the rate of conformational changes in myoglobin after ligand dissociation at ambient temperatures. At low solvent viscosities the rate is independent of viscosity, but at high viscosities it depends on approximately the inverse first power of the viscosity. Kramers theory for unimolecular rate processes can be used to explain this result if the friction term is modified to include protein as well as solvent friction. The theory and experiment suggest that the dominant factor in markedly reducing the rate of conformational changes in myoglobin at low temperatures (<200 K) is the very high viscosity (>10
7
centipoise) of the glycerol-water solvent. That is, at low temperatures conformational substates may not be "frozen" so much as "stuck."
Color: A Motion-Contingent Aftereffect
Authors: Hepler Norva
Published: October 2006

After human observers alternately view green stripes moving up and red stripes moving down for periods of ½ to 4 hours, they see a pink aftereffect when white stripes move up and a green aftereffect when white stripes move down. Longer exposures produce aftereffects which are visible 20 hours after stimulation. Thus, experience which pairs simple attributes (color and motion) of visual stimulation can result in a lasting modification of perception.
Genetic Polymorphism of C′3(β
1C
-Globulin) in Human Serum
Authors: Azen Edwin A. , Smithies Oliver
Published: October 2006

Genetic polymorphism of the third component of human complement and its breakdown products has been detected in human serum by high-voltage starch-gel electrophoresis. Six phenotypes were observed in a study of 113 randomly chosen Caucasians. Their inheritance is controlled by four codominant alleles at an autosomal locus. The gene frequencies in this study were C3
1
, 0.21; C3
2
, 0.77; C3
3
, ∼0.01; and C3
4
, ∼0.004.
Milankovitch Radiation Variations: A Quantitative Evaluation
Authors: Shaw David M. , Donn William L.
Published: October 2006

A quantitative determination of changes in the surface temperature caused by variations in insolation calculated by Milankovitch has been made through the use of the thermodynamic model of Adem. Under extreme conditions, mean coolings of 3.1° and 2.7°C, respectively, at latitudes 25° and 65°N are obtained for Milankovitch radiation cycles. At the sensitive latitude 65°N, a mean cooling below the present temperature for each of the times of radiation minimum is only 1.4°C. This result indicates that the Milankovitch effect is rather small to have triggered glacial climates.
Investigation of Horizon Beta
Authors: Windisch Charles C. , Leyden R. J. , Worzel J. L. , Saito T. , Ewing J.
Published: October 2006

Horizon beta is a subbottom reflector in the North Atlantic deep ocean sediments that extends over a large portion of the North America basin. Cores from an outcrop of beta contained shallow-water Aptian-Albian sediments and deep-water Cenomanian sediments. A core near an outcrop of a deeper horizon, horizon B, contained shallow-water Lower Cretaceous (Barremian-Hauterivian) sediments. These cores can be interpreted to support extensive subsidence of the eastern portion of the basin in early Cretaceous time. It is equally likely that the shallow-water deposits are a result of sediments slumping into an already deep basin. A reconciliation of these interpretations depends upon the JOIDES project.
Absolute Dating of Caribbean Cores P6304-8 and P6304-9
Authors: Rona E. , Emiliani C.
Published: October 2006

Two deep-sea cores from the central Caribbean have been dated by the thorium-230/ protactinium-231 method. The ages obtained are in agreement with the ages previously obtained from other deep-sea cores from the same area. Because of their greater precision, the new dates provide a more accurate time scale for the past 170,000 years.
Boron Modifications Produced in an Induction-Coupled Argon Plasma
Authors: Sullenger Don B. , Phipps Kenneth D. , Seabaugh Pyrtle W. , Hudgens Claude R. , Sands Donald E. , Cantrell Joseph S.
Published: October 2006

Most of the small particles (50 to 100 micrometers in diameter) of microcrystalline β-rhombohedral boron that quickly transit an argon plasma maintained within a radio-frequency induction-coupled torch emerge as better crystallized spheroids of the same crystalline form and nearly the same size as the starting material. A few crystals of each of four distinctive, well-faceted habits are formed along with the general product. Three of these types are monocrystals of the β-rhombohedral polymorph, of the tetragonal-III modification, and of an unreported cubic form of boron. Specimens of the fourth type are polycrystals of another unreported form of boron, apparently consisting of many hexagonal platelets stacked in an imprecise fashion.
Teleostean Urophysis: Stimulation of Water Movement across the Bladder of the Toad
Bufo marinus
Authors: Lacanilao Flor
Published: October 2006

An effect of material from the caudal neurosecretory system of a teleost on the isolated toad bladder is described. Urophysial breis from
Gillichthys mirabilis
result in dose-related water movement across the bladder. As little as one one-hundredth of a urophysis induces a threefold increase in osmotic water movement.
Microbody-Like Organelles in Leaf Cells
Authors: Frederick Sue Ellen , Newcomb Eldon H.
Published: October 2006

An organelle approximately 0.5 to 1.5 microns in diameter, limited by a single membrane, occurs abundantly in the chlorophyllous cells of leaves of several dicotyledonous and monocotyledonous plants. Its finely granular matrix frequently contains crystalline, fibrous, or amorphous inclusions. It is frequently appressed to a chloroplast or squeezed between chloroplasts so that its limiting membrane is in extensive contact with the outer membranes of the chloroplast envelopes. The organelle is probably identical with recently isolated leaf particles that contain enzymes involved in the metabolism of glycolate, a chloroplast product; it is interpreted as a form of plant microbody.
1-Δ
9
-Tetrahydrocannabinol: Neurochemical and Behavioral Effects in the Mouse
Authors: Holtzman David , Lovell Richard A. , Jaffe Jerome H. , Freedman Daniel X.
Published: October 2006

Administration of pure 1-Δ
9
-tetrahydrocannabinol to mice had the following dose-dependent neurochemical and behavioral effects: a slight but significant increase in concentrations of 5-hydroxytryptamine in whole brain; a decrease in concentration of norepinephrine in brain after administration of low doses and an increase after high doses; diminished spontaneous activity, moderate hypothermia, hypersensitivity to tactile and auditory stimuli, and ataxia after low doses; and sedation, pronounced hypothermia, and markedly diminished spontaneous activity and reactivity after high doses. The duration of the effects on body temperature and spontaneous activity correlated generally with the changes in brain amines. The characteristic changes in brain amines do not correspond exactly to those observed with other psychotropic drugs.
Mole Rat Spalax: Evolutionary Significance of Chromosome Variation
Authors: Wahrman J. , Goitein Ruth , Nevo E.
Published: October 2006

Four forms of mole rats with diploid numbers of chromosomes of 52, 54, 58, and 60, respectively, were found in Israel and the vicinity. The differences between the chromosome sets are due to whole-arm (Robertsonian) changes and pericentric inversions. The geographic distribution of the different forms is contiguous. Only a few hybrid individuals have been discovered. These chromosome forms are tentatively considered as sibling species, almost completely isolated by cytogenetic and possibly ethological mechanisms. The weak dispersal powers of mole rats may have contributed to a rapid fixation of adaptive homozygous chromosomal changes.
Pan-Cultural Elements in Facial Displays of Emotion
Authors: Ekman Paul , Sorenson E. Richard , Friesen Wallace V.
Published: October 2006

Observers in both literate and preliterate cultures chose the predicted emotion for photographs of the face, although agreement was higher in the literate samples. These findings suggest that the pan-cultural element in facial displays of emotion is the association between facial muscular movements and discrete primary emotions, although cultures may still differ in what evokes an emotion, in rules for controlling the display of emotion, and in behavioral consequences.
Vitamin K and Coumarin Anticoagulants: Dependence of Anticoagulant Effect on Inhibition of Vitamin K Transport
Authors: Lowenthal Julius , Birnbaum Henry
Published: October 2006

Coumarin anticoagulants inhibit the release of plasma clotting factor VII by vitamin K in liver slices from vitamin K-deficient animals without inhibition of protein synthesis. When the ratio of vitamin K to coumarin anticoagulant is kept constant, but the concentrations are increased, the inhibition disappears. This suggests that the pharmacological action of coumarin anticoagulants depends on irreversible inhibition of normal vitamin K transport to its site of action. At higher concentrations of vitamin K the inhibition can be surmounted, because vitamin K can enter the cell by an alternate route that is not inhibited by coumarin anticoagulants.
High-Pressure Mechanical Instability in Rocks
Authors: Byerlee James D. , Brace William F.
Published: October 2006

At a confining pressure of a few kilobars, deformation of many sedimentary rocks, altered mafic rocks, porous volcanic rocks, and sand is ductile, in that instabilities leading to audible elastic shocks are absent. At pressures of 7 to 10 kilobars, however, unstable faulting and stick-slip in certain of these rocks was observed. This high pressure-low temperature instability might be responsible for earthquakes in deeply buried sedimentary or volcanic sequences.
Positive Contrast in the Runway Obtained with Delay of Reward
Authors: Shanab Mitri E. , Sanders Richard , Premack David
Published: October 2006

The failure to find positive contrast effects in the runway may be attributed to a ceiling effect that can be overcome with the use of delay of reward. Rats were trained one trial a day in a runway with small, medium, or large reward. When a shift to large reward was combined with delay of reward, shift groups slowed down less than controls.