bluuebunny/crossref_metadata_2025 huggingface dataset:
Increased Activities of Glycogenolytic Enzymes in Liver after Splanchnic-Nerve Stimulation
Authors: Shimazu Takashi , Fukuda Aoi
Published: October 2006

Electrical stimulation of the splanchnic nerve of rabbits caused a marked increase, within 30 seconds after the onset of stimulation, in liver-glycogen phosphorylase and glucose-6-phosphatase activities. The increased activity of liver phosphorylase after splanchnic-nerve stimulation was likewise observed in adrenalectomized and pancreatectomized rabbits. Glycogen content of the liver decreased only slightly after 5-minute stimulation.
Polonium-210 Analyses of Vegetables, Cured and Uncured Tobacco, and Associated Soils
Authors: Berger K. C. , Erhardt W. H. , Francis C. W.
Published: October 2006

Analysis of the edible portion of vegetables and samples of green leaf tobacco failed to show polonium-210. The cured samples of leaf tobacco and the soils that were analyzed all contained small quantities of the element. Muck soils contained three times as much Po
210
as did mineral soils. Solutions used commonly to extract "available" forms of many mineral elements failed to extract a detectable amount of Po
210
. Indications are that Po
210
or its radioactive precursors are not taken up from the soil directly by plant roots but rather by sorption in dead, moist plant materials at the atmosphere-plant interface.
Sleep: Effects of a Restricted Regime
Authors: Webb Wilse B. , Agnew H. W.
Published: October 2006

Eight young male subjects were permitted to sleep only 3 hours out of each 24 for 8 days. Electroencephalographic recordings were made during the 3-hour period of sleep. There was an increase in the amount of deep sleep (stage 4) during this period. On a recovery night, the first 6 hours revealed a significant increase in deep sleep, and beyond this period there was a sharp increase in stage 1-rapid eye movement sleep.
Germination of Lily Pollen: Respiration and Tube Growth
Authors: Dickinson David B.
Published: October 2006

Germinating pollen of
Lilium longiflorum
(cv. Ace) briefly exhibited a high rate of respiration before pollen tubes began to grow. A second period of high respiration occurred while tubes were growing. Between these periods respiration proceeded at a lower rate. Respiration was stimulated by 2,4-dinitrophenol to occur at approximately the same rate in all three periods.
Cyclopentanoid Terpene Biosynthesis in a Phasmid Insect and in Catmint
Authors: Meinwald Jerrold , Happ George M. , Labows John , Eisner Thomas
Published: October 2006

The stick insect,
Anisomorpha buprestoides
, and the catmint,
Nepeta cataria
, produce closely related cyclopentanoid terpenes, anisomorphal and nepetalactone. Tracer experiments with isotopes indicate that anisomorphal is synthesized by the walking stick from normal terpene precursors (acetate or mevalonate). In the catmint plant, isolated leaf disks synthesized nepetalactone, utilizing the same precursors.
Microinjection of Mouse Eggs
Authors: Lin Teh Ping
Published: October 2006

A technique has been developed for injecting known amounts of liquids into fertilized one-celled mouse eggs by use of a calibrated ocular micrometer superimposed on the terminal regions of the injection pipette. From 128 pronuclear eggs, each injected with 180 or 770 cubic microns of bovine gamma globulin at a concentration of 25 milligrams per milliliter in citrate-Locke's solution and then transferred to the oviducts of pregnant foster mothers, 18 living fetuses developed; from 74 eggs, each injected with 2730 cubic microns, 5 fetuses survived. The living fetuses that developed from the injected eggs were smaller than normal in 6 of 23 surviving experimental fetuses as contrasted to only 1 of 19 control fetuses.
Lipoprotein Patterns in Acrylamide Gel Electrophoresis
Authors: Raymond Samuel , Miles James L. , Lee Jessie C. J.
Published: October 2006

Lipoproteins of serum stained before electrophoresis gave distinct patterns in acrylamide gel of 3-percent concentration. Samples compared in parallel on gel slabs showed qualitative differences in migration rates of β-lipoprotein bands.
Application of High-Resolution Semiconductor Detectors in X-ray Emission Spectrography
Authors: Bowman Harry R. , Hyde Earl K. , Thompson Stanley G. , Jared Richard C.
Published: October 2006

Solid-state devices developed primarily for nuclear gamma spectroscopy have many potential uses in x-ray analysis.
Structure and Organization of the Living Mitotic Spindle of
Haemanthus
Endosperm
Authors: Bajer Andrew , Allen Robert D.
Published: October 2006

New details of mitotic spindle structures in the endosperm of
Haemanthus katherinae
(Bak) have been demonstrated by differential interference microscopy. Spindle fibers are clearly seen in the living spindle extending from the kinetochores to the polar region. Individual spindle fibers consist of a bundle of smaller filaments which diverge slightly from the kinetochore and intermingle with filaments from other spindle fibers as they approach the polar region. The degree of intermingling increases during metaphase and anaphase. The chromosomes stop moving when the spindle fibers are still 5 to 10microns long; then the fibers disappear. These observations explain some aspects of spindle movements which were difficult to reconcile with earlier concepts of spindle organization.
An Examination of "Transfer of Learning" by Nucleic Acid
Authors: Luttges Marvin , Johnson Terry , Buck Clayton , Holland John , McGaugh James
Published: October 2006

Nucleic acid extracted from brains of trained animals and injected intraperitoneally into naive animals produced no "transfer of learning" effect on several tasks under many conditions. P
32
-Labeled RNA was not found in the brain after intraperitoneal administration. Even intraventricular injections of nucleic acid produced no "transfer" effect.
Imagery: Effect of a Concealed Figure in a Stimulus
Authors: Eagle Morris , Wolitzky David L. , Klein George S.
Published: October 2006

A concealed figure formed by the contours of a perceptually dominant figure influenced the content of viewers' subsequent imagery, although in describing the stimulus they showed no awareness of the concealed figure even after several exposures.
Seasonal Variation in Mating Behavior in Cats after Desensitization of Glans Penis
Authors: Aronson Lester R. , Cooper Madeline L.
Published: October 2006

The glans penis in 14 sexually experienced cats was desensitized by section of the nerves dorsalis penis. These males mounted the estrous female readily but they were so disoriented that they could not achieve intromission. Reduced sensory feedback resulting from the operation and from lack of intromissions caused a decided drop in sexual activity in the fall with recovery in early winter. A latent sexual cycle in male cats is revealed, which corresponds in time to the established female cycle.
Tracers Determine Movement of Soil Moisture and Evapotranspiration
Authors: Zimmermann U. , Münnich K. O. , Roether W. , Kreutz W. , Schubach K. , Siegel O.
Published: October 2006

The downward movement of water in soil is a layered one. Marking a certain layer with hydrogen-isotope tracer, and watching its displacement, makes possible a water balance and gives information on evaporation and groundwater recharge.
Optomotor Response in Human Infants to Apparent Motion: Evidence of Innateness
Authors: Tauber Edward S. , Koffler Sandra
Published: October 2006

Human infants were placed inside a stationary cylinder containing a columnar pattern like that used to elicit the optokinetic reflex. By sequential illumination of the columns, the pattern was made to appear to rotate. Optokinetic nystagmus was clearly evoked in 64.7 percent of the subjects, with a weak-positive response in an additional 11.8 percent.
Nicotinamide-Adenine Dinucleotide in Tubercle Bacilli Exposed to Isoniazid
Authors: Bekierkunst A.
Published: October 2006

There is a decrease in the content of nicotinamide-adenine dinucleotide of tubercle bacilli grown in the presence of isoniazid. In extracts of tubercle bacilli, the activity of nicotinamide-adenine dinucleotidase is nil or very small; after incubation with the drug the enzyme becomes active. Isoniazid also increases the activity of the enzyme after it is partially activated by heating. There may be a correlation between the capacity of isoniazid to activate the enzyme and the decrease in the dinucleotide content of the tubercle bacilli.
Magnesium Ions: Activity in Seawater
Authors: Pytkowicz R. M. , Duedall I. W. , Connors D. N.
Published: October 2006

The activity of magnesium ions in seawater was determined from solubility data and found to be between the values determined by Platford and by Garrels and Thompson. Our value may result from extensive formation of magnesium sulfate ion pairs.
Pressure-Induced Phases of Sulfur
Authors: Geller S.
Published: October 2006

At least three phases of sulfur may be induced at pressures between 16 and 65 kilobars. A fibrous form obtained at pressures of 27 kilobars and higher appears to be closely related to the form obtained when plastic sulfur is chilled and stretched. Crystals of the fibrous form are orthorhombic with
a
= 13.8,
b
= 32.4, and
c
= 9.25 Å. Thus far the results are in accord with deductions made by Prins and co-workers that the sulfur atoms are arranged in helices with ten atoms and three turns per 13.8-Å period, and that these helices are essentially close-packed. The unit cell contains 16 ten-atom chain lengths. The probable space groups to which the crystal may belong are
C c m m, C c 2 m
, or

C c m 2
1

. These imply that the structure must contain both right- and left-handed helices and that at least half the helices have some disorder about their axes. The other two phases appear to have structures related to that of the fibrous form, but analyses of them has not progressed as far. One of these phases appears to be ω-sulfur.
Perception of Temporal Order and Relative Visual Latency
Authors: Rutschmann Ruth
Published: October 2006

Judgments of temporal order to monocular pairs of flashes of equal luminance delivered at various onset asynchronies to the light-adapted fovea and periphery show that uncertainty of temporal order results when the onset of the foveal flash is delayed. Relative latencies vary as a function of peripheral (nasal vs. temporal) locus stimulated.
Attention-Based Motion Perception
Authors: Cavanagh Patrick
Published: October 2006

Two "attentive" tracking tasks reveal the existence of an attention-based motion process. In the first task, oppositely rotating luminance and color gratings were superimposed. Because of masking from the color grating, the bars of the luminance grating were not visible; nevertheless, their motion was visible and it determined the perceived direction of the stimulus rotation. On the other hand, the bars of the color grating were visible but they could only be seen to move (in the opposite direction to the overall stimulus rotation) when they were tracked with attention. In a second task, the perceived velocity of a color grating, typically slow at equiluminance, speeded up when individual bars were attentively tracked. These findings demonstrate two independent motion processes: one that is "low-level" or automatic in that it signals motion even in the absence of attention to the stimulus, and one that is mediated by attention to visible features and provides accurate velocity judgments independently of the features being tracked.
Djerfisherite, Alkali Copper-Iron Sulfide: A New Mineral from Enstatite Chondrites
Authors: Fuchs Louis H.
Published: October 2006

A new mineral, essentially a potassium-copper-iron sulfide, occurs in accessory amounts in the enstatite chondrites Kota Kota (a find) and St. Marks (a fall), and has been identified visually in the enstatite achondrite Pena Blanca Springs (a fall). The x-ray diffraction pattern, electron-microprobe analysis, and its appearance in polished sections all serve to identify it.
Olfactory Discrimination in the Rabbit Olfactory Glomerulus
Authors: Leveteau J. , MacLeod P.
Published: October 2006

Slow potentials evoked by odor stimulation were recorded from individual glomeruli in the olfactory bulb. Systematic analysis of responses to nine different, arbitrarily selected stimuli strongly suggests a certain amount of discrimination. This fact seems to reflect in the first synapse of the olfactory tract the type of discrimination that was recently demonstrated within olfactory neuroepithelium.
Diagenesis of Carbonate Sediments: Interaction of Magnesium in Sea Water with Mineral Grains
Authors: Berner Robert A.
Published: October 2006

Samples of natural fine-grained carbonate sediment from Florida Bay, Florida, undergo mole-for-mole cation exchange with aqueous solutions of MgCl
2
and CaCl
2
in the laboratory. The exchange reaction, which involves the surface of the grains of sediment, can be essentially described by a simple mass action-law equation. Enrichment of Mg
++
beyond the amounts found within particle interiors should take place on the surface of CaCo
3
sediments immersed in sea water; it may be on both exchangeable and unexchangeable sites.
Inhibitory and Facilitatory Effect of Two Related Peptides on Extinction of Avoidance Behavior
Authors: Bohus B. , de Wied D.
Published: October 2006

The polypeptide chain which constitutes the first ten amino acids of the ACTH molecule inhibits extinction of a shuttle-box avoidance response. If the phenylalanine molecule in the 7th position of this peptide is replaced by its dextrorotatory form, extinction is facilitated.
Atmospheric Gases and Particulates in Panama
Authors: Lodge James P. , Pate John B.
Published: October 2006

The concentrations of trace gases in tropical air from samples taken on the Isthmus of Panama are compared with those reported by others. The role of a tropical land mass as a sink or source of atmospheric components is discussed.
Iphita limbata
Stal.: Components of Neurosecretory Material
Authors: Seshan K. R. , Ittycheriah P. I.
Published: October 2006

The median neurosecretory cells of the pars intercerebralis of
Iphita limbata
seem to release two demonstrable components, probably representing allatotropin to the corpus allatum and myotropin to the aortic neurohemal site.
Quartz and Magnetite: Oxygen-18-Oxygen-16 Fractionation in Metamorphosed Biwabik Iron Formation
Authors: Perry E. C. , Bonnichsen Bill
Published: October 2006

Oxygen-18-oxygen-16 fractionation of coexisting quartz and magnetite from the Biwabik iron formation varies as a function of distance of the sample from an intrusive contact. This isotope fractionation is related to observed mineralogic variations and compared with a theoretical heat-flow model.
Corticosteroid Responses to Limbic Stimulation in Man: Localization of Stimulus Sites
Authors: Rubin Robert T. , Mandell Arnold J. , Crandall Paul H.
Published: October 2006

Corticosteroids in human plasma and urine increase after amygdala stimulation, and plasma corticosteroids decrease after hippocampus stimulation. Five subjects underwent unilateral temporal lobectomy, and histopathologic localization of electrode sites was attempted. Localization was successful for six sites: three in basolateral amygdala and three in hippocampus.
Ancient Heavy Transport, Methods and Achievements
Authors: Heizer Robert F.
Published: October 2006

That more and larger stones were transported over a much longer time span in the Old than in the New World is obvious. The earlier arrival of the peoples of the Old World at the level of cultural development generally termed "civilization," accompanied as it was by a superior technology, goes far to account for this fact. Similarities, even identities, in techniques employed in transporting heavy stones (for example, sledge, ramps) or beliefs about stones (for example, that stones can will themselves to move or remain fixed) are taken to be fortuitous and independent convergences of the same genre as those cultural parallels recently pointed out by Caso and Rowe.
Anolis carolinensis
: Effects of Feeding on Reaction to Aposematic Prey
Authors: Sexton Owen J. , Hoger Charles , Ortleb Edward
Published: October 2006

During a 15-day experiment, green anoles,
Anolis carolinensis
, were: (i) presented with one of two aposematic insects,
Oncopeltus fasciatus
or
Photinus pyralis
, during days 4, 6, and 8; (ii) maintained on one of four different food levels during days 9-14; and (iii) presented with the original model on day 15. Lizards on low rations tended to capture more
Photinus
on day 15 than did anoles on higher rations. No such correlation was observed with
Oncopeltus
.
Cytoplasmic Domain Heterogeneity and Functions of IgG Fc Receptors in B Lymphocytes
Authors: Amigorena Sebastian , Bonnerot Christian , Drake James R. , Choquet Daniel , Hunziker Walter , Guillet Jean-Gerard , Webster Paul , Sautes Catherine , Mellman Ira , Fridman Wolf Herman
Published: October 2006

B lymphocytes and macrophages express closely related immunoglobulin G (IgG) Fc receptors (FcγRII) that differ only in the structures of their cytoplasmic domains. Because of cell type-specific alternative messenger RNA splicing, B-cell FcγRII contains an insertion of 47 amino acids that participates in determining receptor function in these cells. Transfection of an FcγRII-negative B-cell line with complementary DNA's encoding the two splice products and various receptor mutants indicated that the insertion was responsible for preventing both FcγRII-mediated endocytosis and FcγRII-mediated antigen presentation. The insertion was not required for FcγRII to modulate surface immunoglobulin-triggered B-cell activation. Instead, regulation of activation involved a region of the cytoplasmic domain common to both the lymphocyte and macrophage receptor isoforms. In contrast, the insertion did contribute to the formation of caps in response to receptor cross-linking, consistent with suggestions that the lymphocyte but not macrophage form of the receptor can associate with the detergent-insoluble cytoskeleton.
Ionospheric Topside Sounding
Authors: Calvert W.
Published: October 2006

Over the past few years, the satellite topside sounders have significantly contributed to the understanding of the upper ionosphere. A great quantity of radio echo data has been accumulated, from which the ionospheric electron-density distribution can be determined.

The topside measurements of electron density essentially agree with similar measurements from the ground, except for an occasional 10-percent discrepancy near the peak of the ionosphere. While horizontal non-uniformity is a likely cause, this discrepancy has not yet been adequately explained.

The electron-density scale heights measured at a constant altitude indicate both a higher temperature and a heavier mean ion mass at high latitudes. At low latitudes the topside measurements have shown the detailed latitudinal structure of the equatorial anomaly, demonstrating control by the geomagnetic field.

A variety of electron-density irregularities have been studied. Most are greatly elongated along the magnetic field, and produce echoes either by lateral scattering, if they are thin, or by longitudinal ducting, if they are thick. Some of the thick irregularities are continuous between the hemispheres and support conjugate echo propagation.

The topside sounders have revealed the complex structure of the ionosphere near the auroral zone and at higher latitudes. At night an east-west trough of greatly reduced electron density occurs equatorward of the auroral zone. At the auroral zone itself the electron density is high and quite variable, both in space and time. The electron density at the polar cap within the auroral zone is often uniform and smooth. Ionospheric irregularities are common in the area of the trough and the auroral zone.

Among other satellites, the topside sounders have been used in various plasma studies involving the excitation and propagation of waves. These studies suggest that the ionosphere is an appropriate region for future plasma physics investigations, especially with rocket and satellite payloads designed specifically for that purpose.
Reversal Response Elicited in Nonbeating Cilia of
Paramecium
by Membrane Depolarization
Authors: Naitoh Yutaka
Published: October 2006

Ciliary reversal occurs in response to electrical and chemical stimuli in specimens of
Paramecium caudatum
in which ciliary beat has been completely inhibited by external application of nickel ions. The mechanism underlying ciliary reversal appears, therefore, to differ from that of ciliary beat. The cessation of ciliary beat has no effect on the intracellular potential of
Paramecium
. However, depolarizing action potentials are associated with ciliary reversals in paramecia, treated with nickel, without ciliary beat. Thus, membrane depolarization in this species seems specifically concerned with the ciliary reversal, and not with ciliary beat.
Nucleotide Sequence Repetition: A Rapidly Reassociating Fraction of Mouse DNA
Authors: Waring Michael , Britten Roy J.
Published: October 2006

The separated complementary strands of a minor component in mouse DNA reassociate with each other much more rapidly than do the complementary strands of other DNA's including those of the principal part of mouse DNA. This difference in capacity of the strands to reassociate can be used to effect a preparative separation of the minor component from the principal fraction. The rate constant for reassociation of the minor component, compared with those of viral and bacterial DNA's, indicates that the minor component consists of a short nucleotide sequence present in about one million copies.
Circular Dichroism of Biological Macromolecules
Authors: Beychok Sherman
Published: October 2006

Circular dichroism, the unequal absorption of right and left circularly polarized light, is a manifestation of optical activity in the vicinity of absorption bands. To the experimental scientist interested in the conformation of macromolecules and in the sensitive response of optical activity to conformational alteration, it offers a relatively new and powerful means of understanding the environment of chromophoric residues. As a tool in the elucidation of electronic spectra, it should be useful to the theoretical scientist in identifying weakly allowed absorption bands as well as in providing rotational parameters which can be compared with the developing theory of optical activity. I have stressed application of circular dichroism, to experimental aspects of protein and nucleic acid conformation in solution. Much is still uncertain in particular quantitative details. However, even these early results shed new light and yield new information on the conformation of these molecules.
Chromosomal Polymorphism in the White-Throated Sparrow,
Zonotrichia albicollis
(Gmelin)
Authors: Thorneycroft H. B.
Published: October 2006

In a study of 35 white-throated sparrows five distinct karyotypes were observed. A chromosomal polymorphism is present which involves at least two pairs of macrochromosomes. This species is phenotypically polymorphic with selective breeding occurring between morphs. Phenotype is related to chromosomal constitution, and selective breeding appears to maintain heterozygosity within the population.
Naturally Occurring Antimetabolite Antibiotic Related to Biotin
Authors: Hanka L. J. , Bergey M. E. , Kelly R. B.
Published: October 2006

A crystalline antibiotic produced by
Streptomyces lydicus
has been isolated and shown to be the hitherto unknown α-dehydrobiotin (I). This is active against a variety of grampositive and gram-negative bacteria and fungi. Its antimicrobial activity is reversed by the presence of biotin in growth media.
Transcription Factor IID Mutants Defective for Interaction with Transcription Factor IIA
Authors: Buratowski Stephen , Zhou Hong
Published: October 2006

Transcription factor IID (TFIID) recognizes the TATA element of promoters transcribed by RNA polymerase II (RNAPII) and serves as the base for subsequent association by other general transcription factors and RNAPII. The carboxyl-terminal domain of TFIID is highly conserved and contains an imperfect repetition of a 60-amino acid sequence. These repeats are separated by a region rich in basic amino acids. Mutagenesis of the lysines in this region resulted in a conditional phenotype in vivo, and the mutant proteins were defective for interactions with transcription factor IIA in vitro. Binding of TFIID to DNA was unaffected. These results suggest that the basic domain of TFIID is important for protein-protein interactions.
Structure, Expression, and Antisense Inhibition of the Systemin Precursor Gene
Authors: McGurl Barry , Pearce Gregory , Orozco-Cardenas Martha , Ryan Clarence A.
Published: October 2006

A gene that encodes systemin, a mobile 18-amino acid polypeptide inducer of proteinase inhibitor synthesis in tomato and potato leaves, has been isolated from tomato,
Lycopersicon esculentum
. Induction of proteinase inhibitors in plants is a response to insect or pathogen attacks. The gene has 10 introns and 11 exons, ten of which are organized as five homologous pairs with an unrelated sequence in the eleventh, encoding systemin. Systemin is proteolytically processed from a 200-amino acid precursor protein, prosystemin. Prosystemin messenger RNA was found in all organs of the plant except the roots and was systemically wound-inducible in leaves. Tomato plants transformed with an antisense prosystemin complementary DNA exhibited greatly suppressed systemic wound induction of proteinase Inhibitor I and II synthesis in leaves.
Tryptophan Deficiency in Rabbit Reticulocytes: Polyribosomes during Interrupted Growth of Hemoglobin Chains
Authors: Hori Makoto , Fisher Joyce M. , Rabinovitz Marco
Published: October 2006

Of several amino acids essential for optimum hemoglobin synthesis by the rabbit reticulocyte, only omission of tryptophan results in polyribosome disaggregation. This disaggregation is prevented by the omission of both tryptophan and an amino acid that is relatively more essential than tryptophan for hemoglobin synthesis. Since tryptophan is located only near the amino-terminal ends of both chains of rabbit globin, the results indicate that single ribosomes and those in polyribosomes are in a dynamic state in the intact cell.
Negro Variant of Glucose-6-Phosphate Dehydrogenase Deficiency (A
-
) in Man
Authors: Yoshida Akira , Motulsky Arno G.
Published: October 2006

Glucose-6-phosphate dehydrogenase in erythrocytes of the Negro type associated with enzyme deficiency (A
-
) was separated by chromatography on a carboxymethyl-Sephadex column from the electrophoretically indistinguishable Negro variant with normal enzyme activity (A
+
). Quantitative immunologic neutralization tests indicated that the A
-
enzyme had about the same enzymatic and serological activity as the A
+
and the normal (B
+
) enzymes. The enzyme activity of the A
-
variant in young erythrocytes was similar to that in young cells from normal individuals, although the activity of the A
-
variant in unfractionated red cells was 10 to 15 percent of normal. These data indicate that the basic defect in the variant enzyme (A
-
) is a structural mutation which causes more rapid degradation of the enzyme during erythrocyte aging.
Structure of Silica Glass
Authors: Hicks John F. G.
Published: October 2006

From configurational entropy considerations, it is estimated that the grains in silica glass are far more likely to have a cristobalite structure than a pentagonal dodecahedral one.
Venus: Atmospheric Evolution
Authors: Dayhoff Margaret O. , Eck Richard V. , Lippincott Ellis R. , Sagan Carl
Published: October 2006

Because of the high temperatures prevailing in the lower atmosphere of Venus, its chemistry is dominated by the tendency toward thermodynamic equilibrium. From the atomic composition deduced spectroscopically, the thermodynamic equilibrium composition of the atmosphere of Venus is computed, and the following conclusions drawn. (i) There can be no free carbon, hydrocarbons, formaldehyde, or any other organic molecule present in more than trace amounts. (ii) The original atomic composition of the atmosphere must have included much larger quantities of hydrogen and a carbon/oxygen ratio ≤ 0.5. (This ratio is now almost precisely 0.5.) (iii) The present atomic proportions of the atmosphere of Venus are so unique that an evolutionary mechanism involving two independent processes seems necessary, as follows. Water, originally present in large quantities, has been photodissociated in the upper atmosphere, and the resulting atomic hydrogen has been lost in space. The resulting excess oxygen has been very effectively bound to the surface materials. (iv) There must be some weathering process, for example, violent wind erosion, to disturb and expose a sufficient quantity of reduced surface material to react with the oxygen produced by photodissociation.
Testosterone Regulation of Sexual Reflexes in Spinal Male Rats
Authors: Hart Benjamin L.
Published: October 2006

Castrated male rats with complete midthoracic spinal transections were maintained on exogenous testosterone; they showed intermittent clusters of genital responses consisting of erections, quick flips, and long flips of the penis when gentle pressure was constantly applied to its base. The number of these genital responses per 30-minute test was markedly influenced by withdrawal or administration of testosterone.
Shock-Wave Compression and X-Ray Studies of Titanium Dioxide
Authors: McQueen Robert G. , Jamieson John C. , Marsh Stanley P.
Published: October 2006

The Hugoniot of the rutile phase of titanium dioxide has been determined to 1.25 megabars, and data show the existence of a phase change at about 0.33 megabar. The volume decrease associated with this transformation appears to be quite large (approximately 21 percent). Rutile, when recovered from shock-loading in excess of the transformation pressure, is found to be irreversibly transformed to the orthorhombic lead dioxide structure (a distortion of the fluorite structure) with parameters
a
, 4.529;
b
, 5.464; and
c
, 4.905 angstroms and a calculated density of 4.374 grams per cubic centimeter. The new phase reverts to rutile at temperatures above 450°C. It is suggested that the new phase may be another diagnostic indicator of meteorite impact on the earth's surface.
Effects of Visual Form on the Evoked Response
Authors: John E. Roy , Herrington R. N. , Sutton Samuel
Published: October 2006

The average visual evoked potentials elicited from relaxed human subjects are different for a blank visual field and one containing a geometric form, are different for different geometric forms of
equal
area, are similar for versions of the same geometric form of
unequal
area, and are different for two printed words equated for total letter area. These findings suggest that the waveform of evoked responses is not determined solely by the set of peripheral receptors which is stimulated, but it also reflects the perceptual content of the stimulus.
Response of a Protein Structure to Cavity-Creating Mutations and Its Relation to the Hydrophobic Effect
Authors: Eriksson A. E. , Baase W. A. , Zhang X. J. , Heinz D. W. , Blaber M. , Baldwin E. P. , Matthews B. W.
Published: October 2006

Six "cavity-creating" mutants, Leu
46
→ Ala (L46A), L99A, L118A, L121A, L133A, and Phe
153
→ Ala (F153A), were constructed within the hydrophobic core of phage T4 lysozyme. The substitutions decreased the stability of the protein at pH 3.0 by different amounts, ranging from 2.7 kilocalories per mole (kcal mol
-1
) for L46A and L121A to 5.0 kcal mol
-1
for L99A. The double mutant L99A/F153A was also constructed and decreased in stability by 8.3 kcal mol
-1
. The x-ray structures of all of the variants were determined at high resolution. In every case, removal of the wild-type side chain allowed some of the surrounding atoms to move toward the vacated space but a cavity always remained, which ranged in volume from 24 cubic angstroms (Å
3
) for L46A to 150 Å
3
for L99A. No solvent molecules were observed in any of these cavities. The destabilization of the mutant Leu → Ala proteins relative to wild type can be approximated by a constant term (∼2.0 kcal mol
-1
) plus a term that increases in proportion to the size of the cavity. The constant term is approximately equal to the transfer free energy of leucine relative to alanine as determined from partitioning between aqueous and organic solvents. The energy term that increases with the size of the cavity can be expressed either in terms of the cavity volume (24 to 33 cal mol
-1
Å
-3
) or in terms of the cavity surface area (20 cal mol
-1
Å
-2
). The results suggest how to reconcile a number of conflicting reports concerning the strength of the hydrophobic effect in proteins.
Site-Specific Incorporation of Novel Backbone Structures into Proteins
Authors: Ellman Jonathan A. , Mendel David , Schultz Peter G.
Published: October 2006

A number of unnatural amino acids and amino acid analogs with modified backbone structures were substituted for alanine-82 in T4 lysozyme. Replacements included α,α-disubstituted amino acids,
N
-alkyl amino acids, and lactic acid, an isoelectronic analog of alanine. The effects of these electronic and structural perturbations on the stability of T4 lysozyme were determined. The relatively broad substrate specificity of the
Escherichia coli
protein biosynthetic machinery suggests that a wide range of backbone and side-chain substitutions can be introduced, allowing a more precise definition of the factors affecting protein stability.
Optical Analysis of Synaptic Vesicle Recycling at the Frog Neuromuscular Junction
Authors: Betz William J. , Bewick Guy S.
Published: October 2006

The fluorescent dyes FM1-43 and RH414 label motor nerve terminals in an activity-dependent fashion that involves dye uptake by synaptic vesicles that are recycling. This allows optical monitoring of vesicle recycling in living nerve terminals to determine how recycled vesicles reenter the vesicle pool. The results suggest that recycled vesicles mix with the pool morphologically and functionally. One complete cycle of release of transmitter, recycling of a vesicle, and rerelease of transmitter appears to take about 1 minute.
Heliacus
(Gastropoda: Architectonicidae) Symbiotic with Zoanthiniaria (Coelenterata)
Authors: Robertson Robert
Published: October 2006

Eight species of
Heliacus
are obligate symbionts with
Zoanthus
and
Palythoa
, colonial zoanthid sea anemones. The gastropods live among
Zoanthus
polyps and under the edges of
Palythoa
incrustations, on which they feed and to which they and their egg masses are attached with sturdy but elastic mucous threads.
Temperature Tolerance of Some Antarctic Fishes
Authors: Somero George N. , DeVries Arthur L.
Published: October 2006

Three species of Antarctic fishes which live in constantly near-freezing waters have a markedly low upper-lethal temperature of 6°C ; this is the lowest upper-lethal temperature reported for any organism. The fishes survive supercooling to —2.5°C. Data on brain metabolism in vitro support the hypothesis that the central nervous system is a primary site of thermal injury.
Hormone-Dependent Differentiation of Mammary Gland: Sequence of Action of Hormones in Relation to Cell Cycle
Authors: Lockwood Dean H. , Stockdale Frank E. , Topper Yale J.
Published: October 2006

Differentiation of mouse mammary gland in vitro requires insulin, hydrocortisone, and prolactin. The epithelial cells must first divide in order to synthesize casein in response to these hormones. Insulin is required for the initiation of DNA synthesis and is also necessary during G
1
phase (after mitosis). Prolactin can elicit the overt differentiative responses after mitosis. Activity of hydrocortisone precedes that of prolactin, that is, after mitosis it is not capable of eliciting the differentiative response.
Gaseous Hydrocarbons in Sea Water: Determination
Authors: Swinnerton J. W. , Linnenbom V. J.
Published: October 2006

Low-molecular-weight hydrocarbons in the C
1
to C
4
range have been detected and measured in sea water. Methane shows by far the highest concentration, followed in order by the C
2
, C
3
, and C
4
fractions. In general, the concentration tends to decrease with depth, but there is a strong indication that a maximum may exist about 30 to 50 meters below the surface.
The Ocean as a Chemical System
Authors: Sillén Lars Gunnar
Published: October 2006

This discussion may have given the feeling that the present composition of ocean water does not result just from blind chance. The composition may in the main be given by well-defined equilibria, and the deviations from equilibrium may be explainable by well-defined processes. However, much remains to be discovered by laboratory work and studies of the natural systems.

For any discussion of equilibria between sediments and sea water to become really fruitful and decisive, one must achieve a much better separation of the various sediment phases than has been obtained hitherto. Equilibrium data for various silicate systems are highly desirable. Studies of various elements indicate that there are serious gaps in our knowledge of soluble species and of equilibrium constants for known species; equilibrium measurements in the ionic medium, sea water, are scarce and not too reliable.

Obviously, better understanding of the system ocean plus air plus sediments and of its history will require close cooperation between geologists, biologists, and chemists of various specialties.
Mitochondrial-Satellite and Circular DNA Filaments in Yeast
Authors: Sinclair John H. , Stevens Barbara J. , Sanghavi Panna , Rabinowitz Murray
Published: October 2006

Mitochondrial DNA of
Saccharomyces cerevisiae
contains a satellite DNA (density, 1.682) that appears to exist as open-ended filaments at least 5 microns long. DNA from intact cells contains circular filaments whose lengths vary from 0.5 to 7 microns, with a great majority at 1.95 microns. The circular DNA has a density similar to that of the major nuclear peak (1.697). When heat-denatured mitochondrial-satellite DNA is renatured, it cross-links to form a molecule that is larger than the native molecule. The formation of cross-links results in hypersharpening of the density profiles in cesium chloride and also leads to failure to pass Millipore filter paper.
Climate Modification by Atmospheric Aerosols
Authors: McCormick Robert A. , Ludwig John H.
Published: October 2006

Theoretical considerations and empirical evidence indicate that atmospheric turbidity, a function of aerosol loading, is an important factor in the heat balance of the earth-atmosphere system. Turbidity increase over the past few decades may be primarily responsible for the decrease in worldwide air temperatures since the 1940's.
Saturation in Milk and Meat Fats
Authors: Patton Stuart , Kesler Earl M.
Published: October 2006

Meat and milk products from ruminants (cows, goats, sheep, and beef animals) contribute 35 to 40 percent of the fat in the average American diet. Such fat is highly saturated, containing less than about 4 percent polyunsaturated fatty acids. The unsaturated plant lipids (fats) ordinarily consumed by the ruminant are hydrogenated (saturated) in the rumen. Transport and incorporation of this hydrogenated fat into meat and milk follows. Rumen hydrogenation does not take place until the fat is broken down to free fatty acids, thus establishing the fact that lipolysis is an essential feature of the process. Circumvention of this lipolysis may lead to more-unsaturated meat and milk fat.
Modified Cilia in Sensory Organs of Juvenile Stages of a Parasitic Nematode
Authors: Ross Mignon M. R.
Published: October 2006

Electron microscopical studies revealed the presence of dendritic nerve processes in sensory organs of the third- and fourth-stage juveniles of
Haemonchus contortus
, which contained structures resembling modified cilia. With few exceptions, the outer circle of fibers consisted of ten doublets, and in place of typical cilia-like central fibers were small microtubules or vesicles varying in number from zero to five.
Life Cycle and Variation of
Prototheca wickerhamii
Authors: El-Ani Arif S.
Published: October 2006

Prototheca wickerhamii
is a yeastlike organism that resembles the green alga
Chlorella
. Nuclear division in coordination with cytoplasmic cleavage gives rise to uninucleate cytoplasmic segments, each of which acquires a delicate cell wall and develops into an autospore. The autospores in this species are spherical; but in a variant that presumably arose as a result of spontaneous mutation, the cytoplasmic cleavage is irregular, and the resultant autospores are ovoid to bacillary. When these variant autospores grow, they swell and round up before the nuclear division begins, producing spherical cells like those seen in wild-type cultures. In view of the fact that species concept in the genus is based on size and shape of cells, the variation limits in these morphological characteristics have significant bearing on species classification.
Sulfite Oxidase Deficiency in Man: Demonstration of the Enzymatic Defect
Authors: Mudd S. Harvey , Irreverre Filadelfo , Laster Leonard
Published: October 2006

An infant who died with neurological abnormalities, mental retardation, and dislocated ocular lenses excreted in his urine abnormally large amounts of
S
-sulfo-L-cysteine, sulfite, and thiosulfate and virtually no inorganic sulfate. The present report establishes the occurrence of an enzymatic defect in this infant. His liver, brain, and kidney specifically lacked sulfite oxidase activity. Deficiency of sulfite oxidase, which has not apparently been described in man, provides a reasonable explanation for the abnormalities in this infant.
Evoked Cortical Potentials: Relation to Visual Field and Handedness
Authors: Eason Robert G. , Groves Philip , White C. T. , Oden David
Published: October 2006

The amplitude of evoked responses of occipital cortex in man depends on the visual field in which the stimulus appears. Greater responses occurred repeatedly for two of three subjects, both left-handed, when the stimulus appeared in the left field than in the right. Subsequent tests of 13 right- and 13 left-handed males indicted that the magnitude of the response of the right lobe, relative to that of the left, was greater for left-handed individuals. We conclude that the difference in amplitude between the two lobes is related to handedness.
Venus: Volcanic Eruptions May Cause Atmospheric Obscuration
Authors: Davidson Gerald T. , Anderson Albert D.
Published: October 2006

High rates of volcanic and tectonic activities are inferred from Venus's high surface temperature. The effects of volcanic effluents, gas and dust, on obscuration in the atmosphere are considered. The optical extinction due to particulate matter is estimated from assumed distributions as to particle size and altitude. As few as ten explosive eruptions per annum would cause significant absorption and scattering of visible light.
Ring D Chromosome: A Second Case Associated with Anomalous Haptoglobin Inheritance
Authors: Bloom Gerald E. , Gerald Park S. , Reisman Leonard E.
Published: October 2006

A second child with a ring D chromosome and anomalous inheritance of haptoglobin has been identified. Autoradiographic studies of peripheral lymphocytes from this child and of those from the previously described patient indicate that the ring in each is derived from chromosome No. 13. These findings are evidence that the locus for the haptoglobin alpha-chain is situated on one end of chromosome No. 13.
Interferon Binding: The First Step in Establishment of Antiviral Activity
Authors: Friedman Robert M.
Published: October 2006

Chick cells incubated at 1°C with interferon fail to develop antiviral activity, but this activity appears subsequent to a 7-hour incubation at 37°C after removal of interferon by repeated washings. Treatment with actinomycin D blocks the development of the latter activity. Cells incubated with interferon at 1°C for up to 1 hour and then washed and incubated for 2 hours at 37°C develop a degree of antiviral activity proportional to the concentration of interferon at initial incubation; at any concentration, the antiviral activity increased with the duration of initial incubation at 1°C, but a maximal response was reached at 10 or 20 minutes. Treatment with trypsin after incubation with interferon at 1°C inhibited development of antiviral activity. Interferon is rapidly bound to a superficial cell site, and this binding is necessary for development of antiviral activity in chick cells.
Chemotherapy of Parasitic Worms: New Biochemical Strategies
Authors: Mansour Tag E.
Published: October 2006

Many chemotherapeutic agents that are effective against parasitic helminths affect cellular regulatory sites that control motility, metabolism, chemotaxis, and egg formation. Serotonin receptors are present in several species of parasitic flatworms and appear to participate in the regulation of motility and carbohydrate metabolism. In
Fasciola hepatica
these receptors are coupled to an adenylate cyclase through a cellular component that requires guanosine triphosphate. Serotonin is the most potent indoleamine agonist, while lysergic acid diethylamide and its 2-bromo derivative are the most potent antagonists. These studies are revealing additional sites in trematodes that may be important for the development of new and more selective chemotherapeutic agents.
Tektites That Were Partially Plastic after Completion of Surface Sculpturing
Authors: Nininger H. H. , Huss Glenn I
Published: October 2006

Among the 50,000 tektites collected over an 8-year period as part of a representative collection of the indochinities in an area near Dalat, South Vietnam, several individual ones have been found that show evidence of having been internally plastic after surface sculpturing was essentially completed. Two drops, which were bent after having formed a thin exterior skin or crust, exhibit surface breaks and stretching of their plastic interiors within the breaks. The lack of deep sculpturing in this interior stretched area, coupled with twisting within the break on one of them, indicates that the surface features on these tektites were formed in the atmosphere and not by etching by soil acids, as had been widely believed.
The (±) Reference: Accuracy of Estimated Mean Components in Average Response Studies
Authors: Schimmel Herbert
Published: October 2006

The (±) reference is defined as the result of alternate addition and subtraction and division by
N
(the number of sample functions). Under suitable conditions both the (±) reference and the variable component (noise) of the usual average tend to be derived from the same Gaussian process, and the former can be used as a measure of the latter. This property is most easily applied when the noise is derived from a stationary process. Application of the (±) reference and the average of the square of the voltage in studies of evoked response is discussed.
Creative Tensions in the Research and Development Climate
Authors: Pelz Donald C.
Published: October 2006

As Andrews and I examined the conditions under which scientists and engineers did effective work, we observed a number of apparent paradoxes. Achievement was high under conditions that seemed inconsistent, including on the one hand sources of stability or confidence (what I have called "security") and on the other hand sources of disruption or intellectual conflict (that is, "challenge"). It appears that, if both are present, the creative tension between them can promote technical achievement.
Oxygen Solubility in Sea Water: Thermodynamic Influence of Sea Salt
Authors: Green E. J. , Carritt D. E.
Published: October 2006

Precise measurements of the solubility of oxygen in sea water show that the solubility declines exponentially with increase in salt concentration according to the empirical Setschenow relation. The deviation from linearity is nearly 0.6 percent from the fitted straight-line relations of previous workers. Our experimental data reveal that, in contrast to the effect predicted by the Debye theory, the salting-out decreases with increasing temperature.