bluuebunny/crossref_metadata_2025 huggingface dataset:
Detection of a Human Intracisternal A-Type Retroviral Particle Antigenically Related to HIV
Authors: Garry Robert F. , Fermin Cesar D. , Hart Darrenn J. , Alexander Steven S. , Donehower Lawrence A. , Luo-Zhang Hong
Published: October 2006

Sjögren's syndrome is an autoimmune disease that is characterized by dryness of the mouth and eyes. The loss of salivary and lacrimal gland function is accompanied by lymphocytic infiltration. Because similar symptoms and glandular pathology are observed in certain persons infected with human immunodeficiency virus (HIV), a search was initiated for a possible retroviral etiology in this syndrome. A human intracisternal A-type retroviral particle that is antigenically related to HIV was detected in lymphoblastoid cells exposed to homogenates of salivary tissue from patients with Sjögren's syndrome. Comparison of this retroviral particle to HIV indicates that they are distinguishable by several ultrastructural, physical, and enzymatic criteria.
Three-Dimensional Structures of Acidic and Basic Fibroblast Growth Factors
Authors: Zhu X. , Komiya H. , Chirino A. , Faham S. , Fox G. M. , Arakawa T. , Hsu B. T. , Rees D. C.
Published: October 2006

Members of the fibroblast growth factor (FGF) family of proteins stimulate the proliferation and differentiation of a variety of cell types through receptor-mediated pathways. The three-dimensional structures of two members of this family, bovine acidic FGF and human basic FGF, have been crystallographically determined. These structures contain 12 antiparallel β strands organized into a folding pattern with approximate threefold internal symmetry. Topologically equivalent folds have been previously observed for soybean trypsin inhibitor and interleukins-1β and -1α. The locations of sequences implicated in receptor and heparin binding by FGF are presented. These sites include β-sheet strand 10, which is adjacent to the site of an extended sequence insertion in several oncogene proteins of the FGF family, and which shows sequence conservation among the FGF family and interleukin-1β.
Stereoscopic Depth Aftereffect Produced without Monocular Cues
Authors: Blakemore Colin , Julesz Bela
Published: October 2006

Random-dot stereograms when used as adaptation stimuli can influence the perceived depth of similar test stimuli. Adaptation for 1 minute is sufficient to evoke this three-dimensional aftereffect for several seconds. This aftereffect must occur after stereopsis because prior to stereopsis no relevant monocular cues exist in these adaptation and test stimuli.
Extralunar Dust in Apollo Cores?
Authors: Barber D. J. , Hutcheon I. , Price P. B.
Published: October 2006

Densities of nuclear tracks exceed 10
11
per square centimeter in several percent of the micrometer-size silicate grains from all depths in the 12- and 60-centimeter lunar cores. Either these grains were irradiated in space as extralunar dust or the ratio of iron to hydrogen in low-energy (about 1 million electron volts per nucleon) solar particles is orders of magnitude higher than in the photosphere.
Predicting College Success of the Educationally Disadvantaged
Authors: Stanley Julian C.
Published: October 2006

Test scores predict the college grades of educationally disadvantaged students at least as well as they do those of the advantaged. High school grades considerably augment the prediction for both groups. Regardless of socioeconomic level, students who are predicted to earn quite low grades within a particular college will tend to have academic difficulties if enrolled in it. There are social and educational justifications for admitting to a particular college some minority-group students who are marginally qualified for it academically, provided that the students are given adequate financial aid and effective remedial courses, tutoring, and coaching. However, if entrants are greatly underqualified academically, new curricula will be required. These may tend to segregate the specially admitted students from the regular student body, thereby diminishing the pacesetter role of the latter. Also, a degree from a special curriculum may not be viewed by employers, graduate schools, and alumni as equivalent to the other degrees awarded by the institution. Thus, admitting students who are seriously underqualified academically for the particular college seems likely to cause frustrations that may be difficult to resolve. Current demands by minority groups for "relevant" courses may reflect the academic difficulties many of their members encounter in present courses more than the educational unsuitability for them of such courses.
Adenosine 3′,5′-Monophosphate in Nervous Tissue: Increase Associated with Synaptic Transmission
Authors: McAfee Donald A. , Schorderet Michel , Greengard Paul
Published: October 2006

Brief periods of stimulation of the preganglionic nerve fibers produced a severalfold increase in the content of adenosine 3′,5′-monophosphate in superior cervical sympathetic ganglia, whereas postganglionic stimulation did not. These and other experiments indicated that the increased concentrations of adenosine 3′5′-monophosphate were closely associated with the process of synaptic transmission. This increase occurred primarily in postsynaptic cells.
Hydroxyl Orientation in Muscovite as Indicated by Electrostatic Energy Calculations
Authors: Giese R. F.
Published: October 2006

The electrostatic energy of the 2
M
1
muscovite structure, KAl
2
(Si
3
Al)O
10
(OH)
2
, has been calculated as a function of the orientation of the hydroxyl group (O-H distance = 0.97 angstrom). The minimum in the electrostatic energy occurs when the OH bond makes an angle of 18° with the cleavage plane and an angle of 31° with the b-axis (in the
a-b
plane), which is 2.5° away from the orientation of the transition moment as determined from infrared measurements on single crystals. If the K
+
ion is excluded from the calculation, the O-H bond makes an angle of 53° with the cleavage plane. This indicates the strong influence that the interlayer cation exerts on the hydroxyl hydrogen in mica structures.
Theoretical and Experimental Basis for a Specific Countertransport System in Membranes
Authors: Cussler E. L. , Evans D. Fennell , Matesich M. A.
Published: October 2006

A sodium ion carrier transport system contains the antibiotic monensin in the membrane and uses a
p
H gradient as an energy source. The experimental results are in accord with theoretical predictions based on a mechanism which is understood on a molecular level.
A Gorilla-Sized Ape from the Miocene of India
Authors: Simons E. L. , Pilbeam David
Published: October 2006

A large ape existed in India at the close of the Miocene or the beginning of the Pliocene epochs; this ape shows a complex of anatomical structures at the opposite pole from its contemporary,Ramapithecus. Although found in the same beds, the two seldom occur at the same exact sites and levels. Considering the thickness of these beds, recovery close to Haritalyangar does not, of itself, prove sympatry of these two different kinds of Hominoidea. However, both are definitely present at one recently located site representing, most probably, a death assemblage.

Observations by the authors on scores of chimpanzees suggest that, at least in this ape, wear gradients on molar crowns exist, but that the wear differential between adjacent molars is almost never raised to the degree seen in mostRamapithecus.Dryopithecus indicusandD. fontani(from southern France), in contrast, show almost no wear gradient at all; that is, whether an individual is dentally young or old, wear on all three molars and the two premolars has proceeded to about the same degree. It is of considerable importance in understanding hominid phylogeny to be able to stress that an ape known to be contemporary withRamapithecusshows far less differential wear than does the hominid. This, in turn, strongly suggests that the molar eruption sequence ofD. indicuswas rapid, while that of the hominid was delayed. The implication is that, as far back as the late Miocene, the hominid maturation period was lengthened, relative to that of apes. A further fact which emerges is that the rate of interstitial wear was faster in the Haritalyangar ape than in the hominid contemporary with it. This, together with its large size, flatness of unworn tooth crowns, and other associated characters, suggests thatD. indicusis in, or close to, the ancestry ofGigantopithecus. From this emerges yet another object lesson, emphasizing the caution one has to observe in the manner and method by which ancient and modern apes are compared and contrasted. None of the species of Hominoidea dealt with here, whether pongid (D. indicusandPan troglodytes) or hominid (R. punjabicus), accumulates either interstitial or crown wear at the same rate or in the same manner.
Underground Nuclear Explosions: Tectonic Utility and Dangers
Authors: Toksöz M. Nafi , Kehrer Harold H.
Published: October 2006

The tectonic strain energy released by several underground nuclear explosions has been calculated through an analysis of seismic surface waves. The proportionally great amount of energy released in certain events suggests the possible uses for, as well as the hazards of, underground testing.
Sex Difference in the Number of Sympathetic Neurons in the Spinal Cord of the Cat
Authors: Calaresu Franco R. , Henry James L.
Published: October 2006

Counts of preganglionic sympathetic neurons in the spinal cords of four male and four female cats were obtained. The number of these neurons in males was significantly greater than that in females. These data suggest that the numbers of neurons in the mammalian central nervous system are different in the two sexes.
Core Binding Energy Difference between Bridging and Nonbridging Oxygen Atoms in a Silicate Chain
Authors: Yin Lo I , Ghose Subrata , Adler Isidore
Published: October 2006

The x-ray photoelectron spectra of the oxygen 1
s
level of olivines contain a single component whereas those of pyroxenes contain two components with an intensity ratio of 2:1 and an energy separation of about 1 electron volt. We interpret these two components to be the result of the binding energy differences between nonbridging and bridging oxygen atoms within a silicate chain in the pyroxene structure.
Effects of Long-Term Reserpine Treatment on Brain Tyrosine Hydroxylase and Behavioral Activity
Authors: Segal David S. , Sullivan John L. , Kuczenski Ronald T. , Mandell Arnold J.
Published: October 2006

Treatment of rats with reserpine (for 8 or 9 days) produced a temporally related increase in behavioral activity and in tyrosine hydroxylase activity in the midbrain. Weight loss resulting from such treatment was not sufficient, by itself, to account for either the behavioral or enzymatic changes. The results support the role of catecholamines in behavioral arousal.
Uroporphyrinogen III Cosynthetase Activity in the Fox Squirrel (
Sciurus niger
)
Authors: Levin Ephraim Y. , Flyger Vagn
Published: October 2006

The activity of uroporphyrinogen III cosynthetase in hemolyzates and tissue extracts from fox squirrels is much less than in similar preparations from gray squirrels. Low activity of this enzyme explains the production of large amounts of uroporphyrin I by the fox squirrel. Members of this species thus provide a small-animal model for studies of congenital erythropoietic porphyria, a hereditary disease of man and cattle which is associated with a similar partial deficiency of uroporphyrinogen III cosynthetase.
Prolonged Color Blindness Induced by Intense Spectral Lights in Rhesus Monkeys
Authors: Harwerth R. S. , Sperling H. G.
Published: October 2006

Prolonged exposure of rhesus monkeys to intense blue light produces long-term changes which are consistent with loss of response of those cones that contain a photopigment with peak absorption at 445 nanometers. The 90 percent reduction of spectral sensitivity in the blue region has lasted more than 5 months. Reduced sensitivity to long wavelengths is produced by adaptation to light of 520 nanometers. This reduced sensitivity, which lasts no more than 30 days, is attributed to a temporary loss of response of the cones containing a photopigment with peak absorption at 535 nanometers.
Light Adaptation in the Rat Retina: Evidence for Two Receptor Mechanisms
Authors: Green Daniel G.
Published: October 2006

Light adapting the rat retina with transient white flashes too dim to bleach a substantial amount of visual pigment produces a change in electroretinogram spectral sensitivity and an increase in flicker fusion frequency. Increment threshold curves obtained with a long wavelength adapting stimulus and a short wavelength test stimulus show rod saturation.
Acceleration of Nitrogen Ions to 7.4 Gev in the Princeton Particle Accelerator
Authors: White M. G. , Isaila M. , Prelec K. , Allen H. L.
Published: October 2006

Nitrogen ions in charge states N
5+
and N
6+
have been accelerated in the Princeton Particle Accelerator to 4 and 7.4 billion electron volts (Gev), respectively. An external N
5+
beam of 1 × 10
6
particles per second has been obtained and focused to a 6-millimeter-diameter spot. The N
6+
beam was about 2 × 10
5
particles per second. The total charge-changing collision cross section of N
5+
in water vapor was determined as a function of ion energy. The improvement in vacuum necessary to increase the N
5+
beam at least tenfold was calculated. The N
6+
total cross section is probably smaller than that of N
5+
at the higher energies.
Intracellular Signaling by 14-hydroxy-4,14-
Retro
-Retinol
Authors: Buck Jochen , Derguini Fadila , Levi Ester , Nakanishi Koji , Hämmerling Ulrich
Published: October 2006

In mammals, retinol is the precursor for retinoids, which affect various aspects of morphogenesis and development. However, B lymphocytes, although retinol-dependent, do not use retinoic acid as mediator. Retinol is metabolized by B lymphocytes and other cell lines to optically active 14-hydroxy-4,14-
retro
-retinol; it is this compound that mediates the growth control. Thus another second messenger molecule, in addition to retinoic acid and retinal, is derived from retinol.
Electrical Generation of Natural Aerosols from Vegetation
Authors: Fish Birney R.
Published: October 2006

It is suggested that an alternative, or additional, source of the blue haze above heavily forested areas may be the generation of submicrometer-sized wax particles by the action of strong electrical fields at the tips of pine needles and other wax-covered plant surfaces. Exposure of pine needles to high potential gradients results in the production of airborne wax particles with diameters less than 0.6 micrometer.
Psychotomimetic
N
-Methylated Tryptamines: Formation in Brain in vivo and in vitro
Authors: Saavedra Juan M. , Axelrod Julius
Published: October 2006

The use of a sensitive enzymatic assay demonstrates that tryptamine occurs normally in rat brain. Intracisternal administration of [
14
C]tryptamine results in the formation of
N
-methyl- and dimethyltryptamine (a psychotomimetic compound) in the rat brain. An enzyme that converts tryptamine and
N
-methyltryptamine to
N
-methyl- and dimethyltryptamine was found to be present in rat and human brain. The
N
-methylation of tryptamine was inhibited by normally occurring compounds present in rat brain.
Spacecraft Propulsion: New Methods
Authors: Alfvén Hannes
Published: October 2006

Cosmic plasmas contain energy which may be tapped and used for spacecraft propulsion. The energy needed for launching a spacecraft could be supplied to it from the ground through a plasma channel in the atmosphere.
Polyamino Acids: Preparation from Reported Proportions of "Prebiotic" and Extraterrestrial Amino Acids
Authors: Saunders Mary A. , Rohlfing Duane L.
Published: October 2006

Polyamino acids were thermally prepared from the proportions of amino acids identified (sometimes after hydrolysis) among the products of simulated prebiotic syntheses and (after hydrolysis) in lunar and meteoritic samples. Inferences are made concerning the composition of prebiotic protein and the possible extraterrestrial existence of protein-like polymers.
Deficient Activity of Hepatic Acid Lipase in Cholesterol Ester Storage Disease
Authors: Burke Joseph A. , Schubert William K.
Published: October 2006

Absence of lysosomal acid lipase activity in the liver is described in cholesterol ester storage disease and Wolman's disease. This enzyme deficiency may result in the excess hepatic cholesterol ester found in both conditions. However, clinical, genetic, and histopathologic differences suggest that the two conditions are separate diseases not completely explained by deficient enzyme activity.
Human X Chromosome Carries Quantitative Genes for Immunoglobulin M
Authors: Grundbacher F. J.
Published: October 2006

Concentrations of immunoglobulin M in serum were one-third higher in females than in males in the Black and White populations of Virginia. In family studies, a much closer correlation was shown between boys and their mothers than between boys and their fathers. The immunoglobulin M concentrations in girls were more closely correlated with those of their fathers than with those of their mothers. The higher mean values for IgM in females and the relative magnitudes of the correlation coefficients between parents and offspring support the hypothesis that the X chromosome of man carries genes with an effect on IgM concentration. These patterns were not demonstrated for immunoglobulins A or G.
Cyclic Adenosine Monophosphate Phosphodiesterase in Brain: Effect on Anxiety
Authors: Beer Bernard , Chasin Mark , Clody Donald E. , Vogel John R. , Horovitz Zola P.
Published: October 2006

Drugs that reduce anxiety may be mediated by cyclic adenosine monophosphate in the brain because (i) potent anxiety-reducing drugs are also potent inhibitors of brain phosphodiesterase activity; (ii) dibutyryl cyclic adenosine monophosphate has the ability to reduce anxiety; (iii) the methylxanthines show significant anxiety-reducing effects; (iv) theophylline and chlordiazepoxide produce additive anxiety-reducing activity; and (v) there is a significant correlation between the anxiety-reducing property of drugs and their ability to inhibit phosphodiesterase activity in the brain.
Salicylate: Action on Normal Body Temperature in Rats
Authors: Satinoff Evelyn
Published: October 2006

Rats receiving intraperitoneal injections of sodium salicylate (30 to 300 milligrams per kilogram of body weight) showed a decline in rectal temperature of up to 5.5°C when placed in a 5°C environment. High dosages of salicylate lowered the rectal temperatures of rats kept in a 23°C environment. The finding that salicylate can lower nonfebrile body temperature suggests that this class of antipyretic agents does affect normal temperature regulation.
Galactonic Acid in Galactosemia: Identification in the Urine
Authors: Bergren William R. , Ng Won G. , Donnell George N. , Markey Sanford P.
Published: October 2006

Galactose is converted to galactonic acid in vivo in man. Galactonate was isolated from the urine of galactosemia patients who had been given galactose orally. The identity of the galactonate was established by gas-liquid chromatography and by the preparation of derivatives.
Noradrenaline Nerve Terminals in Human Cerebral Cortices: First Histochemical Evidence
Authors: Nyström Bo , Olson Lars , Ungerstedt Urban
Published: October 2006

The cerebral and cerebellar cortices of man are richly provided with varicose noradrenaline nerve terminals, which are visualized by fluorescence histochemistry of brain smears obtained by a new technique. The density of such nerves in human cortices equals that of the rat. The method permits simple and rapid analysis of noradrenergic nerves of the human cortex during routine neurosurgical operations.
Potassium and Sodium in Frog Muscle
Authors: Gulati Jagdish , Reisin Ignacio L.
Published: October 2006

Sodium-rich frog muscles are found to extrude sodium and reaccumulate potassium at 0°C. The uptake of potassium by these muscles is studied at three different temperatures as a function of external potassium concentration, K
ex
. The steady-state potassium content of the tissue is related to K
ex
by a sigmoidal cooperative curve at all temperatures. These results are compared with findings on a mammalian smooth muscle.
Chromosomal RNA: Its Properties
Authors: Holmes David S. , Mayfield John E. , Sander Gernot , Bonner James
Published: October 2006

We describe the properties of a special class of RNA associated with chromatin. We discuss why this RNA should be considered a distinct class of RNA and not an artifactual degradation product of either transfer or ribosomal RNA.
Fluorescent Modification of Adenosine 3′,5′-Monophosphate: Spectroscopic Properties and Activity in Enzyme Systems
Authors: Secrist John A. , Barrio Jorge R. , Leonard Nelson J. , Villar-Palasi Carlos , Gilman Alfred G.
Published: October 2006

The synthesis of a highly fluorescent analog of adenosine 3′,5′-monophosphate, namely, 1,N
6
-ethenoadenosine 3′,5′-monophosphate, has provided a powerful probe for systems involving adenosine 3′,5′-monophosphate. The potential utility of this analog is indicated by its long fluorescent lifetime, detectability at low concentration, and relatively long wavelength of excitation (300 nanometers). In protein kinase systems it is a highly acceptable substitute for adenosine 3′,5′-monophosphate.
Rapid Light-Induced Decrease in Pineal Serotonin
N
-Acetyltransferase Activity
Authors: Klein David C. , Weller Joan L.
Published: October 2006

Light acting by way of the eye causes the dark-induced activity of serotonin
N
-acetyltransferase in the pineal gland of the rat to decrease with a halving time of about 3 minutes. This effect, which is one of the more rapid physiological changes known to occur in the activity of any enzyme that metabolizes biogenic amines, appears to explain the rapid increase in the concentration of pineal serotonin that is caused by light exposure at night.
Enhancement of Lobster Growth
Authors: Hughes John T. , Sullivan John J. , Schleser Robert
Published: October 2006

Selected captive lobsters have been successfully mated at the Massachusetts Lobster Hatchery. Progeny raised in warm seawater grew at least four times as fast as lobsters grown at ambient ocean temperatures. These studies demonstrate that lobsters will reach sexual maturity (a weight of about 454 grams) in less than 2 years, compared to 8 years at ambient temperatures in Canadian waters. A further reduction in this time has been achieved by phenotypic selection for fast-growing lobsters. Our initial success in accelerating growth and in mating selected parents suggests that lobster farming may be possible.
Reverse Transcriptases of Primate Viruses as Immunological Markers
Authors: Scolnick Edward M. , Parks Wade P. , Todaro George J.
Published: October 2006

Antibodies were prepared against the DNA polymerases (reverse transcriptases) of three potentially oncogenic RNA viruses of primates. Two type C viruses, isolated from a woolly monkey fibrosarcoma and from a gibbon ape lymphosarcoma, have polymerases that are immunologically related to each other and are distinct from the type C viruses isolated from other mammals.
Cat Hemoglobin:
p
H-Dependent Cooperativity of Oxygen Binding
Authors: Hamilton Marit N. , Edelstein Stuart J.
Published: October 2006

Cat hemoglobin has a lower cooperativity and oxygen affinity than most mammalian hemoglobins. In contrast to the usual invariance of cooperativity with
p
H, a rise in cooperativity with
p
H is predicted by the allosteric model for low-affinity hemoglobins. Such a
p
H-dependent cooperativity for cat hemoglobin has been found.
Circadian Involvement in Termination of the Refractory Period in Two Sparrows
Authors: Turek Fred W.
Published: October 2006

Endogenous daily rhythmicity is involved in the short-day photoperiodic response of breaking the refractory period in both white-crowned and golden-crowned sparrows. Under a modified "coincidence model," short-day photoperiodic induction occurs when light is noncoincident with a specific phase of an internal rhythm.
Strengite Dissolution in Flooded Soils and Sediments
Authors: Patrick W. H. , Gotoh S. , Williams B. G.
Published: October 2006

Strengite (FePO
4
⋅ 2H
2
O) undergoes partial dissolution under the reducing conditions existing in a flooded soil. The greatest release of phosphate and iron occurs under conditions of low oxidation-reduction potential in combination with low
p
H.
Norepinephrine-Containing Neurons: Changes in Spontaneous Discharge Patterns during Sleeping and Waking
Authors: Chu Nai-shin , Bloom Floyd E.
Published: October 2006

Norepinephrine-containing neurons of the locus coeruleus of the cat were recorded with microelectrodes during unrestrained sleeping and waking. The recorded neurons were subsequently defined by combined fluorescence histochemistry of catecholamines and production of microlesions at recording sites. These pontine units show homogeneous changes in discharge patterns with respect to sleep stages, firing slowly during drowsy periods and slow wave sleep and firing in rapid bursts during paradoxical sleep. These data provide a direct correlation between the activity of defined catecholamine-containing neurons and the spontaneous occurrence of sleep stages.
Camptothecin Blocks Memory of Conditioned Avoidance in the Goldfish
Authors: Neale J. H. , Klinger P. D. , Agranoff B. W.
Published: October 2006

Intracranial injection of 10 to 75 micrograms of camptothecin, a plant alkaloid that blocks RNA synthesis in eucaryotic cells, blocks incorporation of tritiated uridine into RNA in the goldfish brain. Injection of 10 to 50 micrograms of the drug within 1.5 hours of training results in greatly diminished memory, tested 1 week later. Injection of the drug 5 or 24 hours after training produces no measurable effect on retention of the learned response.
Lignification in Trees: Indication of Exclusive Peroxidase Participation
Authors: Harkin John M. , Obst John R.
Published: October 2006

Syringaldazine did not turn purple on cross sections of tree branches or saplings or on cambial tissue cultures unless hydrogen peroxide was added; this indicated the absence of laccase but presence of peroxidase in lignifying cells. Peroxidase, therefore, apparently is the only enzyme that polymerizes
p
-coumaryl alcohols to lignin in trees.
Trapped Free Radicals and Electrons in Organic Glasses
Authors: Willard John E.
Published: October 2006

Free radicals, hydrogen atoms, and electrons produced in rigid organic glasses at sufficiently low temperatures have lifetimes of minutes to years. They can be studied by their electron spin resonance spectra and, in the case of electrons, by their optical spectra, recombination luminescence, and electrical conductivity. The decay kinetics of these reaction intermediates serve to distinguish those trapped as geminate pairs or in spurs of high concentration from those formed with random distributions. Electron spin resonance studies of relaxation times and of the spectra of radical pairs provide further evidence on geometrical distributions. The decay rates of radicals combining with reactive geminate partners are dependent on the size and shape of the radical, the temperature, and the nature of the matrix. Decay is much slower in deuterated matrices than in protiated matrices. The factors that control the physical trapping of electrons in organic glasses are under intensive investigation. There is evidence that many electrons trapped relatively weakly during irradiations at 4°K deepen their traps by orientation of dipoles when the matrix is warmed; that most electrons are trapped in the field of the geminate positive ion; that in some matrices the traps have a bound excited state to which the electron can be promoted without detrapping; and that trapped electrons can tunnel to solute molecules with a higher electron affinity than the trap depth.
Condensation Nucleus Discriminator Making Optical Measurements on Fog: A Tool for Environmental Research
Authors: Hart Edwin J. , Schmidt Klaus H. , Vasudevan Keelathur N.
Published: October 2006

An instrument providing a new, rapid, and accurate method of determining the number and critical radii of condensation nuclei with radii under 200 angstroms is described. Based on the principle of the cloud chamber, the instrument measures transient changes in the attenuation and scattering of a monochromatic light beam by the growing fog droplets. From data obtained the absolute number concentration and radii of condensation nuclei can be calculated. Preliminary studies of aerosol formation in beta-irradiated mixtures of air and sulfur dioxide showed that carbon monoxide and methane inhibit the formation of nuclei; relative rate constants can be deduced. Some applications of this instrument for environmental and basic research are pointed out.
Streptozotocin-Induced Pancreatic Insulitis: New Model of Diabetes Mellitus
Authors: Like Arthur A. , Rossini Aldo A.
Published: October 2006

Multiple small injections of streptozotocin in mice produce pancreatic insulitis, with progression to nearly complete beta cell destruction and diabetes mellitus. The timing and appearance of the inflammatory islet lesions suggest but do not prove that streptozotocin acts by initiating a cell-mediated immune reaction. Ultrastructural evidence of abundant type C viruses within beta cells of treated mice suggests that streptozotocin may activate murine leukemia virus in vivo in susceptible hosts.
Induction and Ecological Significance of Gigantism in the Rotifer
Asplanchna sieboldi
Authors: Gilbert John J.
Published: October 2006

Dietary α-tocopherol and cannibalism together induce the giant, campanulate morphotype. Campanulates, unlike the two smaller female morphotypes, do not respond to α-tocopherol by forming male-producing offspring. Campanulate production probably is very significant ecologically, allowing a rapid, adaptive response to increased prey size and a rapid reproductive rate uninterrupted by sexuality and consequent dormancy.
Fire and the Nitrogen Cycle in California Chaparral
Authors: Christensen Norman L.
Published: October 2006

Analysis of soils from burned and unburned chaparral indicates that high nitrate concentrations following fire are due to the addition of ammonium and organic nitrogen in the ash. Inhibition of mineralization in unburned chaparral results in low nitrate concentrations. Fluctuations in the amount of soil nitrate in unburned chaparral are the direct result of foliar leaching.
Capacitor Electrode Stimulates Nerve or Muscle without Oxidation-Reduction Reactions
Authors: Guyton David L. , Hambrecht F. Terry
Published: October 2006

Porous tantalum disks, available as "slugs" from the capacitor industry, have large available surface area and a thin insulating coating of tantalum pentoxide. When implanted, they fill with extracellular fluid and operate as capacitor-stimulating electrodes having high capacitance per unit volume. Capable of stimulating excitable tissue without generating electrochemical by-products, these electrodes should provide a safer interface between neural prosthetic devices and human tissue.
Lead Pollution: Records in Southern California Coastal Sediments
Authors: Chow Tsaihwa J. , Bruland Kenneth W. , Bertine Kathe , Soutar Andrew , Koide Minoru , Goldberg E. D.
Published: October 2006

The present anthropogenic lead fluxes into sediments from the Santa Monica, San Pedro, and Santa Barbara basins of Southern California are, respectively, 0.9, 1.7, and 2.1 micrograms of lead per square centimeter of sea bottom per year; the natural (prepollution) rates for these three basins were, respectively, 0.24, 0.26, and 1.0 microgram of lead per square centimeter per year. Studies of isotopic composition indicate that lead pollutants in coastal sediments are derived mainly from the combustion of lead additives in gasoline.
Insecticide Inhibition of 5α-Dihydrotestosterone Binding in the Rat Ventral Prostate
Authors: Wakeling Alan E. , Visek Willard J.
Published: October 2006

The chlorinated hydrocarbon insecticides dieldrin and
o
,
p
′-DDT inhibit binding of 5α-dihydrotestosterone to specific receptor proteins in rat prostate cytosol. Dieldrin is less inhibitory than
o
,
p
′-DDT.
Failure of Limiting Antigen Doses to Selectively Stimulate High-Avidity Memory Cells
Authors: Segre Diego , Segre Mariangela
Published: October 2006

Mouse spleen cells secondarily stimulated with a small dose of antigen, which elicited few antibody-forming cells, produced antibodies of avidity no greater than that of antibodies synthesized by cells stimulated with an optimal antigen dose. This result is in conflict with the hypothesis that maturation of the immune response is based on competition for limiting amounts of antigen among cells with receptors of varying avidity.
N
-Acetyl-β-hexosaminidase: Role in the Degradation of Glycosaminoglycans
Authors: Thompson Jerry N. , Stoolmiller Allen C. , Matalon Reuben , Dorfman Albert
Published: October 2006

Extracts of cultured normal human skin fibroblasts released radioactivity from a
14
C-labeled heptasaccharide prepared by addition of [
14
C]
N
-acetylgalactosamine to the nonreducing terminus of a hexasaccharide derived from chondroitin 4-sulfate whereas fibroblast extracts from patients with Tay-Sachs and Sandhoff-Jatzkewitz diseases did not. The results suggest that
N
-acetyl- β-hexosaminidase A is responsible for degradation of the oligosaccharide substrate.
Stability of Catecholamines and Propranolol Covalently Bound to Sepharose and Glass Beads
Authors: Yong Man Sen
Published: October 2006

Catecholamines and propranolol were chemically bound to Sepharose and glass beads and washed extensively. The complexes were unstable and bound ligands were gradually released into the supernatants.
Plant Mycoplasmas: Serological Relation between Agents Associated with Citrus Stubborn and Corn Stunt Diseases
Authors: Tully J. G. , Whitcomb R. F. , Bove J. M. , Saglio P.
Published: October 2006

Growth-inhibition and precipitin tests established that antigens of the helical mycoplasma-like organism (
Spiroplasma citri
) associated with citrus stubborn disease are serologically related to antigens in corn infected with stunt disease but not in healthy corn.
Methylated Forms of Arsenic in the Environment
Authors: Braman Robert S. , Foreback Craig C.
Published: October 2006

Environmental samples were analyzed for arsenate and arsenite ions and the methylarsenic acids in nanogram amounts. Dimethylarsinic acid and methylarsonic acid were found in natural waters, bird eggshells, seashells, and human urine.
Encoding of Geographic Dialects in the Auditory System of the Cricket Frog
Authors: Capranica Robert R. , Frishkopf Lawrence S. , Nevo Eviatar
Published: October 2006

The frequency sensitivity of the auditory nervous system of cricket frogs
(Acris)
varies geographically. This variation is closely matched to the spectral energy in their mating calls, thus enabling them to respond preferentially to the calls of their local dialect.
Aggregation of HL-A Antigens at the Lymphocyte Surface Induced by Antiserum to β
2
-Microglobulin
Authors: Poulik M. D. , Bernoco Marietta , Bernoco D. , Ceppellinni R.
Published: October 2006

Rabbit antiserum to human β
2
-microglobulin followed by goat antiserum to rabbit immunoglobulin induces aggregation of β
2
-microglobulin at the lymphocyte surface, as shown by immunofluorescence and by acquisition of resistance to lysis by complement. This treatment also affects all HL-A antigens of the cell, which cap together with β
2
-microglobulin, so that the cell becomes resistant to lysis upon addition of antibodies to HL-A in the presence of complement. These findings suggest that a physical linkage exists between these two classes of polypeptides at the surface of the living cell and is in agreement with recent biochemical data obtained by others with cell membrane preparations.
Near Identity of Cognitive Structure in Two Ethnic Groups
Authors: DeFries J. C. , Vandenberg S. G. , McClearn G. E. , Kuse A. R. , Wilson J. R. , Ashton G. C. , Johnson R. C.
Published: October 2006

As part of a large-scale family study in Hawaii, Americans of either Japanese or European ancestry were administered a battery of 15 cognitive tests. Principal component analyses (varimax rotations) yielded the same four major cognitive factors for each of the two ethnic groups, and these factors are defined by strikingly similar factor loadings.
Radon-222 from the Island of Hawaii: Deep Soils Are More Important than Lava Fields or Volcanoes
Authors: Wilkening Marvin H.
Published: October 2006

The mean flux of radon-222 atoms from the island of Hawaii is 0.45 atom per square centimeter per second. Lava fields occupy 50 percent of the land area, but their radon flux is only 1 percent of that from deep volcanic soils. The island yields approximately 10 curies of radon-222 per hour to the air surrounding it. The radon-222 contribution of volcanoes is negligible.
Elemental Mercury Evolution Mediated by Humic Acid
Authors: Alberts James J. , Schindler James E. , Miller Richard W. , Nutter Dale E.
Published: October 2006

Elemental mercury is formed in aqueous solution by the chemical reduction of mercuric ion in the presence of humic acid. The reduction proceeds via first order kinetics (rate constant, 0.009 hour-
1
) and is dependent on
p
H. The reaction mechanism involves interaction of the ionic metal species with the free radical electrons of the humic acid.
Purgatorius
, an Early Paromomyid Primate (Mammalia)
Authors: Clemens William A.
Published: October 2006

Fragmentary mandibles of
Purgatorius unio
Van Valen and Sloan from the Puercan (approximately early Paleocene), Garbani Locality, Montana, preserve associated postcanines. Their morphology indicates that this mammal was an early paromomyid primate and suggests that primate ancestry does not include currently known members of the palaeoryctid and leptictid Insectivora or of the Condylarthra.
Choice in Free-Ranging Wild Pigeons
Authors: Baum William M.
Published: October 2006

A flock of free-ranging wild pigeons were trained to peck at buttons which, when operated, allowed brief access to grain. Although only one bird at a time could have access to the buttons, the pecks of the group were treated as an aggregate. When they chose between two buttons, each of which could occasionally produce grain, the ratios of pecks at the buttons approximately equaled the ratios of the grain presentations obtained from them. This accords with a relation well substantiated in the laboratory, the matching law. It suggests that the matching law may apply to the behavior of higher organisms in natural environments.
Thyrotropin-Releasing Hormone: Regional Distribution in Rat Brain
Authors: Winokur A. , Utiger R. D.
Published: October 2006

A sensitive and specific radioimmunoassay has been used to measure the distribution of thyrotropin-releasing hormone (TRH) in rat brain. All areas of brain tested, except cerebellum, contained readily measurable amounts of TRH. The hypothalamus contained only 31.2 percent of the total brain content of TRH. These results support recent suggestions of central actions for TRH in addition to its hypophysiotropic functions.
Noise-Induced Reduction of Inner-Ear Microphonic Response: Dependence on Body Temperature
Authors: Drescher Dennis G.
Published: October 2006

The rate of reduction of chinchilla cochlear microphonic response with exposure to steady noise is less at lower body temperatures and greater at higher body temperatures. Before exposure to noise, this auditory response is invariant within the range of temperatures employed. The mechanism of reduction of cochlear response appears to involve processes sensitive to body temperature.
Extracellular Acidosis Protects Ehrlich Ascites Tumor Cells and Rat Renal Cortex against Anoxic Injury
Authors: Penttila Antti , Trump Benjamin F.
Published: October 2006

The present study indicates that extracellular acidosis protects Ehrlich ascites tumor cells and rat kidney cortex cells against injury from anoxia. Parameters measured included cell potassium, adenosine 5′-triphosphate, and uptake of vital dyes. Cells survived longer at a
p
H of 5.6 to 6.5 than at a
p
H of 7.4;
p
H 7.9 was most detrimental. These findings indicate that production of protons by anoxic cells may be a protective feedback mechanism.
Cation Dependence of High-Affinity Angiotensin II Binding to Adrenal Cortex Receptors
Authors: Glossmann H. , Baukal A. , Catt K. J.
Published: October 2006

The specific binding of monoiodinated angiotensin II by particulate receptors from the bovine adrenal cortex is enhanced by addition of sodium and potassium ions, but not other cations. In the presence of 140 millimolar sodium, increased uptake of angiotensin II by adrenal receptors is associated with the appearance of high-affinity binding sites with an association constant of 2 × 10
9
liters per mole.
Free Radicals and Inflammation: Protection of Synovial Fluid by Superoxide Dismutase
Authors: McCord Joe M.
Published: October 2006

Enzymatically generated superoxide radical. by reacting with hydrogen peroxide to produce the hydroxyl radical, depolymerized purified hyaluronic acid and bovine synovial fluid. Since phagocytizing polymorphonuclear leukocytes produce superoxide radicals, this reaction is suggested and shown to be quantitatively feasible as the in vivo mechanism of synovial fluid degradation in an inflamed joint. Superoxide dismutase, and catalase protect synovial fluid against such degradation in vitro.
Neurochemical Correlate of a Spatial Preference in Rats
Authors: Zimmerberg Betty , Glick Stanley D. , Jerussi Thomas P.
Published: October 2006

Spatial (left or right) preferences were determined for rats given foot shock in a T-maze. The animals were killed, and left and right striata were assayed separately for dopamine and left and right teldiencephalic regions were assayed for norepinephrine. Dopamine content was significantly higher (by 12 percent) in the striata contralateral to rats' side preferences than in the ipsilateral striata; there was no such difference for teldiencephalic norepinephrine. The small asymmetry in striatal dopamine content is not due to any learning- or stress-related change induced by the testing procedure but is probably inherent in normal rats. Some spatial behavior appears to be the manifestation of a normal and specific difference in the activity of left and right nigrostriatal systems.
Pulmonary Platelet Aggregates Associated with Sudden Death in Man
Authors: Pirkle Hubert , Carstens Per
Published: October 2006

Six human cases of unexpected sudden death were found to have many platelet aggregates in the small arterial vessels of the lungs. Postmortem examination revealed no other significant findings.
Leukocyte Peroxidase Deficiency in a Family with a Dominant Form of Kuf's Disease
Authors: Armstrong Donald , Dimmitt Sandra , Boehme Diethelm H. , Leonberg Stanley C. , Vogel Wolfgang
Published: October 2006

Use of a spectrophotometric assay of peroxidase with
p
-phenylenediamine as cosubstrate demonstrated deficient enzyme activity in leukocytes from two patients with a dominantly inherited form of ceroid lipofuscinosis (Kuf's disease) and a clinically healthy unaffected sibling. When the reaction was performed in the absence of added hydrogen peroxide, oxidation of the
p
-phenylenediamine cosubstrate (indicating the presence of endogenous peroxide) occurred only with enzyme samples from the three siblings but not with those from a large number of unrelated, unaffected controls. This demonstrates that the deficiency of peroxidase found previously in the recessively inherited infantile and juvenile forms of ceroid lipofuscinosis (Batten-Spielmeyer-Vogt disease) is also present in an adult form with dominant inheritance.
Electron-Optical Observations on the α-Transformation in Troilite
Authors: Putnis A.
Published: October 2006

The transformation from high to low troilite occurs via a transitional structure. The transformation to this transitional state is continuous, whereas that to the low-temperature form is discontinuous. This illustrates alternative metastable behavior in a system when nucleation of the low-temperature phase may be impeded.
Presynaptic Inhibition: Primary Afferent Depolarization in Crayfish Neurons
Authors: Kennedy Donald , Calabrese Ronald L. , Wine Jeffrey J.
Published: October 2006

Inhibition of transmission between tactile sensory neurons and interneurons in the crayfish was investigated by intracellular recording in the presynaptic processes. Inhibition is correlated with a depolarization of the presynaptic process, as in the mammalian spinal cord; the depolarization is accompanied by a conductance increase, and is mediated by interneurons that can be excited by a variety of routes.
Ice Crystal Concentration in Cumulus Clouds: Influence of the Drop Spectrum
Authors: Mossop S. C. , Hallett J.
Published: October 2006

Secondary ice crystals are thrown off when supercooled cloud drops are captured and freeze on a moving target in a cloud at —5°C. The rate of production of these ice crystals is proportional to the rate of accretion of drops of diameter ≥24 micrometers.
Vitamin D in Solution: Conformations of Vitamin D
3
, 1α,25-Dihydroxyvitamin D
3
, and Dihydrotachysterol
3
Authors: Wing Richard M. , Okamura William H. , Pirio Marcel R. , Sine Steven M. , Norman Anthony W.
Published: October 2006

Solution conformations of the A and seco B rings of vitamin D
3
, 1α,25-dihydroxyvitamin D
3
, 1α-hydroxyvitamin D
3
, and dihydrotachysterol
3
have been established by high resolution, 300-megahertz proton magnetic resonance spectroscopy. The A ring of these steroids is dynamically equilibrated between two chair conformers. For vitamin D
3
, 1α-hydroxyvitamin D
3
, and 1α,25-dihydroxyvitamin D
3
the relative proportions of the two conformers are 1 : 1, whereas dihydrotachysterol3 exists principally as only one conformer. Thus, the substituent groups on the A ring may be either equatorially or axially oriented, and suggests a refinement of the existing topological model for vitamin D hormonal activity.
Pioneer 11 Observations of Energetic Particles in the Jovian Magnetosphere
Authors: Van Allen J. A. , Randall B. A. , Baker D. N. , Goertz C. K. , Sentman D. D. , Thomsen M. F. , Flindt H. R.
Published: October 2006

Knowledge of the positional distributions, absolute intensities, energy spectra, and angular distributions of energetic electrons and protons in the Jovian magnetosphere has been considerably advanced by the planetary flyby of Pioneer 11 in November-December 1974 along a quite different trajectory from that of Pioneer 10 a year earlier. (i) The previously reported magnetodisc is shown to be blunted and much more extended in latitude on the sunward side than on the dawn side. (ii) Rigid corotation of the population of protons
E
p
≈ 1 million electron volts in the magnetodisc is confirmed. (iii) Angular distributions of energetic electrons
E
e
> 21 million electron volts in the inner magnetosphere are shown to be compatible with the Kennel-Petschek whistler-mode instability. (iv) A diverse body of magnetospheric effects by the Jovian satellites is found. (v) Observations of energetic electrons in to a radial distance of 1.59 Jovian radii provide a fresh basis for the interpretation of decimetric radio noise emission.
Hormonal Release of Programmed Behavior in Silk Moths: Probable Mediation by Cyclic AMP
Authors: Truman James W. , Fallon Ann Marie , Wyatt G. R.
Published: October 2006

The eclosion hormone triggers a stereotyped preprogrammed pattern of behavior in silk moths. The effects of the hormone were duplicated by the injection of dibutyryl adenosine 3′,5′-monophosphate, adenosine 3′,5′-monophosphate (cyclic AMP), or guanosine 3′,5′-monophosphate (cyclic GMP) into theophylline-treated pharate moths. Treatment with theophylline reduced the latency of the response to a low dose of hormone, presumably by blocking phosphodiesterase. Endogenous levels of cyclic AMP, but not cyclic GMP, increased significantly in the central nervous system within 10 minutes after hormone injection. We conclude that an early step leading to the release of the eclosion motor program is an increase in cyclic AMP in target neurons of the central nervous system.