bluuebunny/crossref_metadata_2025 huggingface dataset:
Plastics on the Sargasso Sea Surface
Authors: Carpenter Edward J. , Smith K. L.
Published: October 2006

Plastic particles, in concentrations averaging 3500 pieces and 290 grams per square kilometer, are widespread in the western Sargasso Sea. Pieces are brittle, apparently due to the weathering of the plasticizers, and many are in a pellet shape about 0.25 to 0.5 centimeters in diameter. The particles are surfaces for the attachment of diatoms and hydroids. Increasing production of plastics, combined with present waste-disposal practices, will undoubtedly lead to increases in the concentration of these particles. Plastics could be a source of some of the polychlorinated biphenyls recently observed in oceanic organisms.
Apollo 14 Active Seismic Experiment
Authors: Watkins Joel S. , Kovach Robert L.
Published: October 2006

Explosion seismic refraction data indicate that the lunar near-surface rocks at the Apollo 14 site consist of a regolith 8.5 meters thick and characterized by a compressional wave velocity of 104 meters per second. The regolith is underlain by a layer with a compressional wave velocity of 299 meters per second. The thickness of this layer, which we interpret to be the Fra Mauro Formation, is between 16 and 76 meters. The layer immediately beneath this has a velocity greater than 370 meters per second. We found no evidence of permafrost.
Prehispanic Adaptation in the Ixtapalapa Region, Mexico
Authors: Blanton Richard E.
Published: October 2006

Data accumulated during an intensive survey of Prehispanic settlements in the Ixtapalapa Peninsula region enables me to formulate hypotheses regarding the nature of sociocultural change and adaptation during the Prehispanic period. A summary of these hypotheses follows. The Early and Middle Formative period was a time of low population, when most communities were located on or near the agriculturally productive lakeshore plain zone. During the subsequent period, attendant upon the development in the central highlands of more productive varieties of maize, population increased, and for the first time the agriculturally marginal piedmont zone was colonized. This process may have resulted in the enhancement of status differentiation in these societies because some communities maintained access to the preferred land along the lakeshore plain zone. Also, occupation of a variety of environmental zones may have encouraged symbiosis, which could have further enhanced status differentiation as some individuals or groups became the focuses of exchange networks. During the Late Formative period, developments along this line proceeded throughout the Valley of Mexico, but later, during the Terminal Formative period, some groups prospered more than others because they were favorably situated for the construction of large-scale irrigation systems. The foremost example of the latter is Teotihuacan, which eventually dominated the population of the Ixtapalapa Peninsula region, as well as the remainder of the Valley of Mexico and probably adjacent groups in the central highlands.

From A.D. 0 to A.D. 700, the region was dominated by Teotihuacan. This was a period of low population and apparently rural settlement patterns. A similar situation existed during the Late Toltec period as Tula dominated the region. I suggest that Teotihuacan and Tula had similar relationships with their rural peripheries; specifically, they were largely extractive and so dominated rural populations that they were the only important focuses of exchange and craft specialization. Population declined in the rural areas in part because they were too far from the urban centers to participate effectively in the exchange networks. In contrast, the Aztec period was characterized by the presence of a number of urban centers scattered widely over the valley; these centers served as the focuses of exchange and specialization. A similar situation may have characterized the Early Toltec period. During the Aztec period, the combination of intensive local and valleywide symbiosis plus the introduction of chinampas allowed the population to reach the greatest density of the Prehispanic period.
Rotational Inertia of Continents: A Proposed Link between Polar Wandering and Plate Tectonics
Authors: Kane Martin F.
Published: October 2006

A mechanism is proposed whereby displacement between continents and the earth's pole of rotation (polar wandering) gives rise to latitudinal transport of continental plates (continental drift) because of their relatively greater rotational inertia. When extended to short-term polar wobble, the hypothesis predicts an energy change nearly equivalent to the seismic energy rate.
Cortical Afferents to the Entorhinal Cortex of the Rhesus Monkey
Authors: Van Hoesen Gary W. , Pandya Deepak N. , Butters Nelson
Published: October 2006

Although the entorhinal cortex is a major contributor of afferents to the hippocampus and dentate gyrus, knowledge of its own afferents has been vague. Regions of both the frontal and temporal lobes were found to contribute afferents to this region of the brain. These afferents form probable multisynaptic links in pathways connecting the classical sensory areas of the cortex and the limbic system.
Immunoglobulin M: Fixation of Human Complement by the Fc Fragment
Authors: Plaut Andrew G. , Cohen Stanley , Tomasi Thomas B.
Published: October 2006

The Fc fragment [(Fc)
5
μ, with a molecular weight of 342,000] of human immunoglobulin M from patients with Waldenström's macroglobulinemia has a complement fixing ability approximately 19 times greater on a molar basis than that of the parent immunoglobulin M. This fragment, which occurs naturally as a pentamer fixes human but not guinea pig complement, and this activity remains unchanged even after the fragment is reduced to the monomeric form.
Pressure Measurement Made by the Utilization of Ruby Sharp-Line Luminescence
Authors: Forman Richard A. , Piermarini Gasper J. , Barnett J. Dean , Block Stanley
Published: October 2006

A rapid, convenient technique for precision pressure measurement in the diamond-anvil high-pressure cell, which makes use of the sharp-line (R-line) luminescence of ruby, has been developed. The observed shift is -0.77 ± 0.03 reciprocal centimeters per kilobar for R
1
and -0.84 ± 0.03 reciprocal centimeters per kilobar for R
2
to lower energy and is approximately linear in the range studied (to 22 kilobars). Line-broadening has been observed in some instances and has been tentatively identified with nonhydrostatic conditions surrounding the ruby sample.
Greek Marbles: Determination of Provenance by Isotopic Analysis
Authors: Craig Harmon , Craig Valerie
Published: October 2006

A study has been made of carbon-13 and oxygen-18 variations in Greek marbles from the ancient quarry localities of Naxos, Paros, Mount Hymettus, and Mount Pentelikon. Parian, Hymettian, and Pentelic marbles can be clearly distinguished by the isotopic relationships; Naxian marbles fall into two groups characterized by different oxygen-18/oxygen-16 ratios. Ten archeological samples were also analyzed; the isotopic data indicate that the "Theseion" is made of Pentelic marble and a block in the Treasury of Siphnos at Delphi is probably Parian marble.
Tidal Growth Increments in the Cockle
Clinocardium nuttalli
Authors: Evans John W.
Published: October 2006

Sets of growth lines in the shell of
Clinocardium nuttalli
are extinguished every 13 or 14 increments only to be replaced by other sets, half an increment out of phase with the first. This can be explained only by assuming that the lines are deposited during periods of exposure at low tide. The average duration of an increment is 24 hours and 50 minutes.
Call Types of the
Rana pipiens
Complex in Illinois
Authors: Brown Lauren E. , Brown Jill R.
Published: October 2006

The presence of western, eastern, and northern call types of the
Rana pipiens
complex in Illinois supports evidence from the western United States that this complex can no longer be regarded as one species.
Zinc in
Entamoeba invadens
Authors: Morgan Richard S. , Sattilaro Richard F.
Published: October 2006

Atomic absorption spectroscopy, electron microprobe analysis, and dithizone staining of trophozoites and cysts of Entamoeba invadens demonstrate that these cells have a high concentration of zinc (approximately 10
-6
microgram per cell or 1 percent of their dry weight). In the cysts of this organism, the zinc is confined to the chromatoid bodies, which previous work has shown to contain crystals of ribosomes. The chemical state and function of this zinc are unknown.
Stimulation by Phagocytosis of the Deiodination of L-Thyroxine in Human Leukocytes
Authors: Woeber Kenneth A. , Doherty Gail F. , Ingbar Sidney H.
Published: October 2006

Intact human leukocytes actively deiodinate L-[
131
I]thyroxine, producing mainly inorganic
131
I and chromatographically immobile
131
I-labeled origin material. When phagocytosis is induced, the deiodination is enhanced, a suggestion that deiodination in mediated by a peroxidase-hydrogen peroxide system. L-Thyroxine can serve as a source of iodine for iodination reactions within the leukocyte.
Calcium Transient in Presynaptic Terminal of Squid Giant Synapse: Detection with Aequorin
Authors: Llinás R. , Blinks J. R. , Nicholson C.
Published: October 2006

Microinjection of aequorin, a bioluminescent protein sensitive to calcium, into the presynaptic terminal of the squid giant synapse demonstrated an increase in intracellular calcium ion concentration during repetitive synaptic transmission. Although no light flashes synchronous with individual presynaptic action potentials were detected, the results are considered consistent with the hypothesis that entry of calcium into the presynaptic terminal triggers release of the synaptic transmitter substance.
Auditory Induction: Perceptual Synthesis of Absent Sounds
Authors: Warren Richard M. , Obusek Charles J. , Ackroff John M.
Published: October 2006

Within certain auditory patterns, fainter sounds may be "heard" clearly when replaced by louder sounds having appropriate spectral compositions. This auditory induction of fainter by louder sounds can cancel the perceptual effects of masking. Phonemic restorations, which have been reported previously, appear to be a specialized application to speech of the much broader phenomenon of auditory induction. The rules governing auditory induction indicate that it helps maintain stable auditory perception in our frequently noisy environment.
Spontaneous Transformation of Human Brain Cells Grown in vitro and Description of Associated Virus Particles
Authors: Hooks John , Gibbs C. J. , Chopra H. , Lewis M. , Gajdusek D. C.
Published: October 2006

A human brain cell culture grown in vitro has spontaneously transformed, as determined by morphology, growth characteristics, and karyotype analysis. Virus particles morphologically akin to oncogenic RNA viruses are present in the transformed cells, which are now in subculture 60.
Wiswesser Line Notation: Simplified Techniques for Converting Chemical Structures to WLN
Authors: Koniver Deena A. , Wiswesser William J. , Usdin Earl
Published: October 2006

Techniques have been developed for the generation of Wiswesser Line Notations (WLN), which require knowledge neither of rules for manual conversion of structures to line notations nor of computer programming. The desired WLN are obtained simply by drawing the structures of the compounds of interest on a tablet, which is linked to an appropriately programmed computer.
Around-the-World Atomic Clocks: Observed Relativistic Time Gains
Authors: Hafele J. C. , Keating Richard E.
Published: October 2006

Four cesium beam clocks flown around the world on commercial jet flights during October 1971, once eastward and once westward, recorded directionally dependent time differences which are in good agreement with predictions of conventional relativity theory. Relative to the atomic time scale of the U.S. Naval Observatory, the flying clocks lost 59 ± 10 nanoseconds during the eastward trip and gained 273 ± 7 nanoseconds during the westward trip, where the errors are the corresponding standard deviations. These results provide an unambiguous empirical resolution of the famous clock "paradox" with macroscopic clocks.
Hemoglobin Adaptation for Fast and Slow Water Habitats in Sympatric Catostomid Fishes
Authors: Powers Dennis A.
Published: October 2006

The oxygen equilibria of
Catostomus insignis
hemoglobins are
p
H dependent.
Catostomus clarkii
hemoglobins have some components (20 percent) whose oxygen equilibria are independent of
p
H because the alpha chains have NH
2
-termini that are blocked and the beta chains lack the "usual" COOH-terminal histidine. Since the Bohr effect is normally a beneficial phenomenon, the maintenance of some hemoglobins without a Bohr effect must provide a physiological advantage that is habitat specific. The intrastream ecological preferences of these sympatric catostomids suggest that the hemoglobins without the Bohr effect confer an ecological advantage in a swift water habitat.
Single Cell Activity in the Auditory Cortex of Rhesus Monkeys: Behavioral Dependency
Authors: Miller J. M. , Sutton D. , Pfingst B. , Ryan A. , Beaton R. , Gourevitch G.
Published: October 2006

The response to repetitive stimulation of single cells in the auditory cortex of the monkey is dependent upon behavioral performance and training of the subject in a simple auditory discrimination task. In the trained, performing animal, single cells are more responsive than in the animal that is trained but not performing in the task. In the naive monkey, evoked responses are labile and are maintained only with nonrepetitive auditory stimuli.
Deficiency of Kallikrein Activity in Plasma of Patients with Cystic Fibrosis
Authors: Rao G. J. S. , Posner L. A. , Nadler H. L.
Published: October 2006

Total kallikrein activity and kallikrein activity inhibited by soybean trypsin inhibitor are significantly reduced in the plasma of patients with cystic fibrosis compared to age-matched controls. The level of the STI inhibited kallikrein activity in the plasma of heterozygotes was significantly different from that in either controls or affected children. However, the individual heterozygote could not be reliably identified in each case.
Apollo 16 Far-Ultraviolet Camera/Spectrograph: Earth Observations
Authors: Carruthers George R. , Page Thornton
Published: October 2006

A far-ultraviolet camera/spectograph experiment was operated on the lunar surface during the Apollo 16 mission. Among the data obtained were images and spectra of the terrestrial atmosphere and geocorona in the wavelength range below 1600 angstroms. These gave the spatial distributions and relative intensities of emissions due to atomic hydrogen, atomic oxygen, molecular nitrogen, and other species—some observed spectrographically for the first time.
Thermal Panting in Dogs: The Lateral Nasal Gland, a Source of Water for Evaporative Cooling
Authors: Blatt Charles M. , Taylor C. Richard , Habal M. B.
Published: October 2006

Two lateral nasal glands appear to provide a large part of the water for evaporative cooling in the panting dog; their function is analogous to that of sweat glands in man. Each gland drains through a single duct which opens about 2 centimeters inside the opening of the nostril. This location may be essential to avoid desiccation of the nasal mucosa during thermal panting. The rate of secretion from one gland increased from 0 to an average of 9.6 g (gland ⋅ hour)
-1
as air temperature was increased from 10° to 50°C. Evaporation of the fluid from the paired glands could account for between 19 and 36 percent of the increase in respiratory evaporation associated with thermal panting. The fluid secreted by the gland was hypoosmotic to plasma.
Crustal Spreading in Southern California
Authors: Elders Wilfred A. , Rex Robert W. , Robinson Paul T. , Biehler Shawn , Meidav Tsvi
Published: October 2006

The current excitement among geologists and geophysicists stemming from the "new global tectonics" has led to a widespread, speculative reinterpretation of continental geology. The Gulf of California and its continuation into the Imperial Valley provide an excellent opportunity for studying the border zone between the North American and Pacific plates, and an interface of continental and oceanic tectonics. The Salton trough, the landward extension of the gulf, is a broad structural depression, comparable in size with the deeper marine basins of the southern part of the gulf, but here partially filled with sediments deposited by the Colorado River.
Quaternary Paleotemperatures and the Duration of the High-Temperature Intervals
Authors: Emiliani Cesare
Published: October 2006

Oxygen isotopic analysis of Caribbean cores P6304-4 and P6304-7, and the close correlation of these cores with other Caribbean and Atlantic cores previously analyzed, make possible the reconstruction of a paleotemperature curve of considerable detail. This curve demonstrates again the unusualness of the present interval of high temperature within the framework of Quaternary climatic evolution, and the need for a close study of man's impact on climate.
Mercury: Surface Composition from the Reflection Spectrum
Authors: McCord Thomas B. , Adams John B.
Published: October 2006

The reflection spectrum for the integral disk of the planet Mercury was measured and was found to have a constant positive slope from 0.32 to 1.05 micrometers, except for absorption features in the infrared. The reflectivity curve matches closely the curve for the lunar upland and mare regions. Thus, the surface of Mercury is probably covered with a lunar-like soil rich in dark glasses of high iron and titanium content. Pyroxene is probably the dominant mafic mineral.
Fluorescamine: A Reagent for Assay of Amino Acids, Peptides, Proteins, and Primary Amines in the Picomole Range
Authors: Udenfriend Sidney , Stein Stanley , Böhlen Peter , Dairman Wallace , Leimgruber Willy , Weigele Manfred
Published: October 2006

Fluorescamine is a new reagent for the detection of primary amines in the picomole range. Its reaction with amines is almost instantaneous at room temperature in aqueous media. The products are highly fluorescent, whereas the reagent and its degradation products are nonfluorescent. Applications are discussed.
Hemoglobin Beta Chain Structural Variation in Mice: Evolutionary and Functional Implications
Authors: Gilman John G.
Published: October 2006

The

Hbb
d

allele at the hemoglobin beta chain locus of
Mus musculus
is composed of two linked genes, coding for structurally different beta chains, βdmin and βdmaj.
Mus caroli
has only one beta chain, which combines structural features of both βdmin and βdmaj and thus may be a Lepore type of beta chain. Sequence data suggest that selection may have been important in the evolution of the mouse beta chains.
Collagen Synthesis in
Xenopus
Oocytes after Injection of Nuclear RNA of Frog Embryos
Authors: Rollins J. W. , Flickinger R. A.
Published: October 2006

A messenger RNA fraction from polysomes of frog larvae or RNA preparations from isolated nuclei of developing frog embryos were injected into growing
Xenopus laevis
oocytes that were incubated with labeled proline. Column chromatography of protein hydrolyzates revealed labeled hydroxyproline after injection of the messenger RNA fraction and neurula nuclear RNA, indicating that the injected material had promoted collagen synthesis.
Apollo 16 Exploration of Descartes: A Geologic Summary
Authors:   Apollo Field Geology Investigation Team
Published: October 2006

The Cayley Plains at the Apollo 16 landing site consist of crudely stratified breccias to a depth of at least 200 meters, overlain by a regolith 10 to 15 meters thick. Samples, photographs, and observations by the astronauts indicate that most of the rocks are impact breccias derived from an anorthositegabbro complex. The least brecciated members of the suite include coarse-grained anorthosite and finer-grained, more mafic rocks, some with igneous and some with metamorphic textures. Much of the traverse area is covered by ejecta from North Ray and South Ray craters, but the abundance of rock fragments increases to the south toward the younger South Ray crater. The Descartes highlands, a distinct morphologic entity, differ from the adjacent Cayley formation more in physiographic expression than in lithologic character.
Hypothalamic Polypeptide That Inhibits the Secretion of Immunoreactive Pituitary Growth Hormone
Authors: Brazeau Paul , Vale Wylie , Burgus Roger , Ling Nicholas , Butcher Madalyn , Rivier Jean , Guillemin Roger
Published: October 2006

A peptide has been isolated from ovine hypothalamus which, at 1 × 10
-9
M
, inhibits secretion in vitro of immunoreactive rat or human growth hormones and is similarly active in vivo in rats. Its structure is H-Ala-Gly-Cys-Lys-Asn-Phe-Phe-Trp-Lys-Thr-Phe-Thr-Ser-Cys-OH. The synthetic replicate is biologically active.
Induction of Choline Phosphotransferase and Lecithin Synthesis in the Fetal Lung by Corticosteroids
Authors: Farrell Philip M. , Zachman Richard D.
Published: October 2006

Rabbit fetuses 23 to 24 days of gestation were injected with either 9-fluoroprednisolone acetate or saline. Three days later the lungs of steroid-treated animals showed a significant increase in lecithin concentration and cholinephosphotransferase activity. In addition, lung slices from these animals incorporated more [
14
C]choline into lecithin. The rise in enzyme activity and [
14
C]choline incorporation was blocked by prior treatment of fetuses with cycloheximide but not by treatment with actinomycin D. It is proposed that the corticosteroids induce de novo synthesis of the lung enzyme, which in turn leads to increased synthesis of lecithin through the choline incorporation pathway. Furthermore, it appears that the site of regulation involves translation of messenger RNA.
Somatosensory Cortex: Structural Alterations following Early Injury to Sense Organs
Authors: Van der Loos Hendrik , Woolsey Thomas A.
Published: October 2006

In mouse somatosensory cortex there are discrete cytoarchitectonic units, called "barrels." Each barrel is related to one sensory vibrissa on the muzzle. Individual vibrissae were carefully injured at birth; 12 to 43 days later, the corresponding barrels proved to be absent. Evidently the sensory periphery has an important influence on the structure of the somatosensory cortex.
Pumice from Thera (Santorini) Identified from a Greek Mainland Archeological Excavation
Authors: Rapp George , Cooke Strathmore R. B. , Henrickson Eiler
Published: October 2006

Pumice fragments recovered from an archeological excavation on the Greek mainland have been correlated by means of index of refraction measurements with the Late Bronze Age volcanic eruption on the island of Thera (Santorini) in the Aegean Sea. Pottery from the strata containing the pumice dates from the 15th century B.C.
Reaction of Hydrated Electrons with Ferricytochrome c
Authors: Lichtin Norman N. , Shafferman Avigdor , Stein Gabriel
Published: October 2006

The reaction of ferricytochrome c with hydrated electrons produced at
p
H 6.8 by radiolysis with electron pulses lasting 50 to 1000 nanoseconds has a specific rate constant of 5.5 × 10
10
liter mole
-1
sec
-1
for the formation of the primary adduct. By using appropriate wavelengths, another fast, consecutive process was demonstrated, with the pure first order rate constant 1.0 × 10
5
sec
-1
. Its characteristics agree with it being an intramolecular process within the enzyme. Approximately 50 percent of all electrons which add to ferricytochrome c end in forming ferrocytochrome c.
Cerebral Hydroxylases: Stimulation by a New Factor
Authors: Gál E. M. , Roggeveen A. E.
Published: October 2006

Cerebral tryptophan 5-hydroxylase and tyrosine hydroxylase are stimulated by a solution of lyophilized, protein-free 30,000g supernatant of brain homogenates (concentrate 1). This preparation can be further purified by passage through Sephadex G-75 and phosphocellulose columns to yield concentrate 2. Unlike concentrate 1, concentrate 2 is unstable after several days of storage even at -27°C. Neither preparation is active without the presence of a reduced pteridine cofactor. The stimulating factor appears to be thermostable, alkali-labile, dialyzable, and light-sensitive.
Conversion of Thyroxine to Triiodothyronine by Cultured Human Cells
Authors: Sterling Kenneth , Brenner Milton A. , Saldanha Victor F.
Published: October 2006

Human liver and kidney cells convert 6 to 10 percent of added thyroxine to triiodothyronine in vitro at 37°C. This extent of conversion is ten times greater than that in control studies with killed cells. Conversion is evident within 10 minutes and appears to be maximal within 1 hour. Greater net triiodothyronine formation results if greater amounts of exogenous thyroxine are added to the system, with no plateau evident even at very high thyroxine concentrations. The addition of high concentrations of nonradioactive triiodothyronine resulted in no evident inhibition of the conversion.
Hormonal Regulation of Growth in Unfertilized Cotton Ovules
Authors: Beasley C. A.
Published: October 2006

Exogenous plant growth regulators can substitute for pollination, fertilization, and subsequent embryo development in cotton. Isolated, unfertilized, immature ovules enlarge in the presence of kinetin, and both enlarge and produce fibers in the presence of indoleacetic acid or gibberellic acid or both. An extract of germinating cotton pollen qualitatively mimics the effect of exogenous hormones.
Electrocardiogram Monitoring: Computerized Detection of Ventricular Changes Induced by Drugs
Authors: Berni Albert J. , Luttges Marvin W. , Dick Donald E.
Published: October 2006

Cardiac arrhythmia was induced in mice by the injection of ouabain, lidocaine, and diphenylhydantoin. Temporal spreading of ventricular electrocardiographic complexes is shown consistently to follow injection of a cardioactive drug and to precede rhythm disturbances. A computerized monitoring technique based on temporal spreading and waveform distortion should find wide clinical and experimental application.
Number of Germ Cells in Known Male and Known Female Genotypes of Vertebrate Embryos (
Oryzias latipes
)
Authors: Quirk J. Gerald , Hamilton James B.
Published: October 2006

The number of primordial germ cells in embryos of known genotypic sex was the same in XY males and XX females until the gonad became recognizable as testis or ovary. It has been claimed that the heterogametic sex chromosome causes the gonad to differentiate as a testis in mammals and as an ovary in birds as a result of earlier and more mitoses. This claim was not supported in the present study where a sex difference in numbers of germ cells was first noted during differentiation of oocytes in the XX embryos.
Admixture Studies and the Detection of Selection
Authors: Adams Julian , Ward Richard H.
Published: October 2006

Three methods can be used to search for evidence of natural selection from admixture studies. These include classification of the admixture estimates into two groups; calculation of the rank correlation between estimates from more than one population; and the testing of admixture estimates for homogeneity. The use of these methods is discussed with special reference to black-white admixture in the United States. Using revised estimates of African gene frequencies, derived from a consideration of the geographical origin of the slaves, we calculated admixture estimates and their variances for five U.S. black populations; Claxton (Georgia); Sapelo Island (Georgia); James Island (South Carolina); Charleston (South Carolina); Oakland (California). Two out of the five populations yielded heterogeneous admixture estimates but all other tests were nonsignificant. The data provide little evidence for the action of selection. The few, inconsistent significant results are more indicative of the action of random drift or biased gene frequency estimates than natural selection, and in general these effects cannot be differentiated. It seems doubtful that admixture studies can ever provide unequivocal evidence for the action of natural selection in human populations. In the search for natural selection, perhaps admixture studies should only be used as a preliminary screening device.
Fine Particles Produced from Automotive Emissions-Control Catalysts
Authors: Balgord William D.
Published: October 2006

High concentrations of metal-containing condensation nuclei have been thermally induced from stabilized catalysts containing chromium, copper, and nickel under conditions closely resembling those found in automobile exhaust. Commercial and developmental catalyst formulations have been found to emit fine particles under a broad range of controlled conditions at temperatures ranging from 185° to 800°C, in filtered air, in a mixture of 3 percent carbon monoxide in molecular nitrogen, and in the product stream of a pulsed flame combustor.
Hormonal Control of Sexual Morphogenesis in Achlya: Dependence on Protein and Ribonucleic Acid Syntheses
Authors: Kane Bernard E. , Reiskind Julia B. , Mullins J. T.
Published: October 2006

The induction of the male sexual organ primordia (antheridial hyphae) by the steroid hormone antheridiol in the water mold
Achlya ambisexualis
requires both transcription and translation. Inhibition of either of these processes eliminates the expected increase in the production and release of the enzyme cellulase, which accompanies the formation of the antheridial hyphae.
Time Differences in the Formation of Meteorites as Determined from the Ratio of Lead-207 to Lead-206
Authors: Tatsumoto Mitsunobu , Knight Roy J. , Allegre Claude J.
Published: October 2006

Measurements of the lead isotopic composition and the uranium, thorium, and lead concentrations in meteorites were made in order to obtain more precise radiometric ages of these members of the solar system. The newly determined value of the lead isotopic composition of Canyon Diablo troilite is as follows:
206
Pb/
204
Pb = 9.307,
207
Pb/
204
Pb = 10.294, and
208
Pb/
204
Pb = 29.476. The leads of Angra dos Reis, Sioux County, and Nuevo Laredo achondrites are very radiogenic, the
206
Pb/
204
Pb values are about 200, and the uranium-thorium-lead systems are nearly concordant. The ages of the meteorites as calculated from a single-stage
207
Pb/
206
Pb isochron based on the newly determined primordial lead value and the newly reported
235
U and
238
U decay constants, are 4.528 × 10
9
years for Sioux County and Nuevo Laredo and 4.555 × 10
9
years for Angra dos Reis. When calculated with the uranium decay constants used by Patterson, these ages are 4.593 × 10
9
years and 4.620 × 10
9
years, respectively, and are therefore 40 to 70 × 10
6
years older than the 4.55 × 10
9
years age Patterson reported. The age difference of 27 × 10
6
years between Angra dos Reis and the other two meteorites is compatible with the difference between the initial
87
Sr/
86
Sr ratio of Angra dos Reis and that of seven basaltic achondrites observed by Papanastassiou and Wasserburg. The time difference is also comparable to that determined by
129
I-
129
Xe chronology. The ages of ordinary chondrites (H5 and L6) range from 4.52 to 4.57 × 10
9
years, and, here too, time differences in the formation of the parent bodies or later metamorphic events are indicated. Carbonaceous chondrites (C2 and C3) appear to contain younger lead components.
Insulin Binding to Cultured Human Fibroblasts Increases with Normal and Precocious Aging
Authors: Rosenbloom Arlan L. , Goldstein Samuel , Yip Cecil C.
Published: October 2006

Specific and nonspecific [
125
I]insulin binding and concentration of unlabeled hormone producing 50 percent competition with 1.0 nanomolar [
125
I]insulin for specific binding sites correlated positively with age of fibroblast donors. Cells from four children with precocious aging—three with progeria and one with Rothmund syndrome—resembled those from the chronologically old.
Large-Scale Variations in the Obliquity of Mars
Authors: Ward William R.
Published: October 2006

Large-scale variations in the obliquity of the planet Mars are produced by a coupling between the motion of its orbit plane due to the gravitational perturbations of the other planets and the precession of its spin axis which results from the solar torque exerted on the equatorial bulge of the planet. The obliquity oscillates on a time scale of approximately 1.2 × 10
5
years. The amplitude of this oscillation itself varies periodically on a time scale of 1.2 × 10
6
years. The present-day obliquity is approximately 25.1 degrees. The maximum possible variation is from about 14.9 to 35.5 degrees. Significant climatic effects must be associated with the phenomenon.
Superinduction of Endogenous Type C Virus by 5-Bromodeoxyuridine from Transformed Mouse Clones
Authors: Lieber M. M. , Livingston D. M. , Todaro G. J.
Published: October 2006

Certain transformed subclones of the mouse cell line BALB/3T3 release 5 to 15 times more type C virus per cell than the parent cell line after treatment with 5-bromodeoxyuridine. Virus release begins within 8 hours and exponentially increases for the first 24 to 48 hours. Superinducibility is associated with the transformed phenotype.
Snapping Behavior of the Shrimp
Alpheus californiensis
Authors: Ritzmann Roy
Published: October 2006

A pair of very smooth disks, located on the claw of the snapping shrimp
Alpheus californiensis
, are temporarily held together by cohesive forces of water. This allows the closer muscle of the claw to generate a large amount of tension before these cohesive forces are overcome, and results in a rapid closing movement.
Ice Nucleation by Solid Solutions of Silver-Copper Iodide
Authors: Passarelli Richard E. , Chessin Henry , Vonnegut Bernard
Published: October 2006

The lattice misfit between ice and silver iodide can be reduced by partial substitution of copper atoms for silver atoms in the silver iodide lattice. The best crystal match is obtained with a composition of CuI-3AgI, which corresponds to the most active silver-copper iodide nucleation catalyst.
Pleistocene Glaciation in the Blue Ridge Province, Southern Appalachian Mountains, North Carolina
Authors: Berkland James O. , Raymond Loren A.
Published: October 2006

Glacial polish, grooves, and striations discovered at an elevation of 1370 meters in the headwaters of Boone Fork on Grandfather Mountain, North Carolina, indicate the former existence of alpine glaciation at a latitude of 36°07′N. The Boone Fork glacier was located 890 kilometers south of the previously recognized southern limit of alpine glaciation in the Appalachian Mountains, and 350 kilometers southeast of the nearest point on the Laurentide ice sheet. This find has significant implications for studies of Pleistocene geomorphology, paleobiology, and paleoclimatology in the eastern United States.
Behavioral Development after Forelimb Deafferentation on Day of Birth in Monkeys with and without Blinding
Authors: Taub Edward , Perrella Philip , Barro Gilbert
Published: October 2006

Four infant monkeys underwent somatosensory deafferentation of both forelimbs within hours after birth. Ambulation, climbing, and reaching toward objects developed spontaneously in each case. Thumb-forefinger prehension could be trained by operant shaping methods. Two infants deafferented at birth and blinded by eyelid closure were retarded in motor development by only 1 to 2 weeks. Results indicate that topographic sensory feedback and autogenetic spinal reflexes are not necessary after birth for the development of most types of movement performed by the forelimb musculature in monkeys.
Premature Births in California Sea Lions: Association with High Organochlorine Pollutant Residue Levels
Authors: DeLong Robert L. , Gilmartin William G. , Simpson John G.
Published: October 2006

Premature pupping in California sea lions has been noted on the breeding islands since 1968. Organochlorine pesticides and polychlorinated biphenyl residues were two to eight times higher in tissues of premature parturient females and pups than in similar tissues of full-term parturient females and pups collected on San Miguel Island in 1970.
The Earth's Mantle: Evidence of Non-Newtonian Flow
Authors: Post Robert L. , Griggs David T.
Published: October 2006

Recent information from experimentally deformed dunite coupled with a reanalysis of data on the Fennoscandian postglacial rebound suggest that the rheological behavior of the upper mantle is distinctly non-Newtonian, and that the shear strain rate is proportional to the shear stress raised to about the third power.
Velocity and Displacement Responses in Auditory-Nerve Fibers
Authors: Zwislocki J. J. , Sokolich W. G.
Published: October 2006

With the help of nonsinusoidal acoustic stimuli, it is demonstrated that most fibers of the auditory nerve respond to both displacement and velocity of the basilar membrane. Except at very high stimulus levels, motion and displacement toward scala tympani produce excitation; motion and displacement toward scala vestibuli produce inhibition. The displacement and velocity responses interact. When both are excitatory or inhibitory, they reinforce each other; when they are of opposite nature, a partial cancellation occurs. The presence of both displacement and velocity responses in the single fibers suggests that outer and inner hair cells of the cochlea interact.
Earthquake-Induced Structures in Sediments of Van Norman Lake, San Fernando, California
Authors: Sims John D.
Published: October 2006

The 9 February 1971 earthquake in the San Fernando Valley damaged the Lower Van Norman Dam severely enough to warrant draining the reservoir. In March 1972 the sediment deposited on the reservoir floor was examined to determine whether the 1971 earthquake had induced sediment deformation and, if so, what types. A zone of deformational structures characterized by small-scale loads and slightly recumbent folds associated with the 1971 earthquake was discovered, in addition to two older zones of load structures. Each of the zones has been tentatively correlated with an historic earthquake.
Sulfur Dioxide Contributions to the Atmosphere by Volcanoes
Authors: Stoiber Richard E. , Jepsen Anders
Published: October 2006

The first extensive measurements by remote-sensing correlation spectrometry of the sulfur dioxide emitted by volcanic plumes indicate that on the order of 10
3
metric tons of sulfur dioxide gas enter the atmosphere daily from Central American volcanoes. Extrapolation gives a minimum estimate of the annual amount of sulfur dioxide emitted from the world's volcanoes of about 10
7
metric tons.
Visual Experience without Lines: Effect on Developing Cortical Neurons
Authors: Pettigrew J. D. , Freeman R. D.
Published: October 2006

Kittens were reared in a planetarium-like visual environment that lacked straight line contours. Cortical neurons were subsequently highly sensitive to spots of light but not to straight lines, in marked contrast to those from a normal cat. If linear contour processing is an innate function it appears to be subject to substantial modification by early visual experience.
Antibodies to Herpesvirus Nonvirion Antigens in Squamous Carcinomas
Authors: Hollinshead Ariel C. , Lee Obong , Chretien Paul B. , Tarpley John L. , Rawls William E. , Adam Ervin
Published: October 2006

Serums from tumor-bearing patients, cured patients, and normal subjects were examined for antibodies to the separated complement-fixing reactive components of nonvirion antigens of herpesvirus type 1 and type 2. The occurrence of antibodies to the antigens was similar in serums from tumor-bearing patients and cured patients. Antibodies to the antigens were observed among 21 of 24 (87 percent) cervical cancer cases, 44 of 49 (90 percent) laryngeal cancer cases, 15 of 24 (62 percent) cases of squamous cell carcinomas of the head and neck excluding the larynx, 2 of 24 (8 percent) nonsquamous cell cancer cases, and 3 of 51 (6 percent) normal subjects. By contrast, no differences were found in the titers of neutralizing antibodies to the virus in serums from laryngeal cancer patients and controls. The observations support an etiologic role of herpesviruses in cervical cancer and in laryngeal cancer, and possibly other squamous cell cancers of the head and neck.
Human Visual Ecology and Orientation Anisotropies in Acuity
Authors: Annis Robert C. , Frost Barrie
Published: October 2006

The visual environment of Cree Indians from the east coast of James Bay, Quebec, is different from that of city-raised Euro-Canadians. So also are their corresponding orientation anisotropies in visual acuity. A Euro-Canadian sample exhibited the usual higher resolution for vertically and horizontally oriented gratings as compared with oblique orientations, while a Cree Indian sample did not. The most parsimonious explanation of these acuity differences is that orientation-specific detectors in humans are tuned by the early visual environment.
The Beginnings of Metallurgy: A New Look
Authors: Wertime Theodore A.
Published: October 2006

In the 9 years since my first survey of early metallurgy appeared in this journal metallurgy has become a major battleground between those who argue independent invention and those who argue diffusion in the evolution of urban civilization. In this new article I contend that:

1) The upland belt and debouching river valleys of southwestern Asia have a clear priority in the beginnings of copper metallurgy and extractive metallurgy generally, suggesting that the forces of urbanization contributing to the rise of metallurgy there were more massive, widespread, and better integrated than elsewhere.

2) The trend to polymetallism, against the background of pyrotechnology generally and the other important technologies of urbanism, established a necessary sequence to early metallurgy. This sequence was a prerequisite to the coming of the Iron Age, which was uniquely contained at first within the environment of Anatolia and the eastern Mediterranean and spread outward from there.

3) The course of metallurgy and possibly of the other urbanizing technologies can best be understood through a process of diffusion and multiple innovation interrelating metallurgical evolution over much of Eurasia, but with the area defined by the Black Sea, the Caspian Sea, the Red Sea, and the eastern Mediterranean as its center. Only in this fashion can we place metallurgy in its proper role as an important subsystem in the rise of civilization.
Domestication of Pulses in the Old World
Authors: Zohary Daniel , Hopf Maria
Published: October 2006

This article reviews the available information on the place of origin and time of domestication of the cultivated pea (
Pisum sativum
), lentil (
Lens culinaris
), broad bean (
Vicia faba
), bitter vetch (
V. ervilia
), and chickpea (
Cicer arietinum
). On the basis of (i) an examination and evaluation of archeological remains and (ii) an identification of the wild progenitors and delimitation of their geographic distribution, it was concluded that pea and lentil should be regarded as founder crops of Old World Neolithic agriculture. Most probably they were domesticated, in the Near East, simultaneously with wheats and barley (certainly not later than the sixth millennium B.C.). Bitter vetch shows a similar mode of origin. The evidence on the broad bean and the chickpea is much more fragmentary and the wild progenitors of these legumes are yet not satisfactorily identified. But also these two pulses emerge as important food elements in Bronze Age cultures of the Near East and Europe.
Long-Term Sensitization of a Defensive Withdrawal Reflex in
Aplysia
Authors: Pinsker Harold M. , Hening Wayne A. , Carew Thomas J. , Kandel Eric R.
Published: October 2006

When a weak tactile stimulus is applied to the siphon of
Aplysia californica,
the animal withdraws the siphon between the parapodia. This defensive withdrawal reflex can be facilitated (sensitized) if the animal is previously given 4 days of training, consisting of four brief noxious stimuli each day. The sensitization of this reflex can last for up to 3 weeks after training and is mediated by the abdominal ganglion which also mediates long-term habituation. This preparation may provide a system for analyzing the neural mechanism of long-term behavioral modifications of complexity which is intermediate between habituation and associative learning.
Premonitory Variations in
S
-Wave Velocity Anisotropy before Earthquakes in Nevada
Authors: Gupta Indra N.
Published: October 2006

Application of nonhydrostatic stress to rock induces velocity anisotropy, causing the S wave to split into two components traveling with somewhat different velocities. Large premonitory changes in the extent of S-wave splitting have been observed for two earthquakes in Nevada. Observations of the difference between the two S-wave velocities may provide a simple method for predicting earthquakes.
Control of Guanylate Cyclase Activity in the Rod Outer Segment
Authors: Pannbacker Richard G.
Published: October 2006

Mammalian photoreceptors contain a guanylate cyclase which has a high specific activity and is inhibited by exposure of the rod outer segment to light. Several minutes are required for this inhibition to take effect, indicating that it is not a step in visual excitation. The activity of the enzyme is sensitive to the concentration of calcium ion in the medium, suggesting that light-induced changes in calcium distribution in the photoreceptor could control guanylate cyclase activity.
Stimulation of Cells by Antibody
Authors: Shearer William T. , Philpott Gordon W. , Parker Charles W.
Published: October 2006

Tumor cell lines exposed to immunoglobulins specific for cell surface antigens developed increased cellular incorporation of [
125
I]iododeoxyuridine and [
3
H]thymidine (up to 200-fold increases over cells treated with normal rabbit immunoglobulins). Antibody-stimulated cells multiplied more rapidly and lived longer than control cells in tissue culture. These observations were made both with cells substituted with 2,4,6-trinitrophenol and purified antibody against 2,4,6-trinitrophenol, and with several cell lines and their respective whole-cell antibodies. Antibodies that were stimulatory at low concentrations were cytotoxic at high concentrations. These observations may have significance in regard to enhancing effects of antibodies on tumor cell growth in vivo.
The Silica-Alumina System: Stable and Metastable Equilibria at 1.0 Atmosphere
Authors: Aksay Ilhan A. , Pask Joseph A.
Published: October 2006

Diffusion couples, consisting of sapphire and fused silica, which were annealed in the temperature range from 1678° to 2003°C and analyzed by electron beam microprobe, have provided data on the stable phase equilibrium of the silica-alumina system. Under stable equilibrium conditions, the intermediate compound of this system, mullite (3Al
2
O
3
⋅ 2SiO
2
), melts incongruently at 1828° ± 10°C and its solid solution field extends from 70.5 to 74.0 percent (by weight) alumina. The stable phase diagram is a composite of the two binary eutectic diagrams: silica-mullite in the absence of alumina and silica-alumina in the absence of mullite. Under metastable conditions, mullite melts congruently at ≈ 1890° ± 10°C and its solid solution field extends to ≈ 83.2 percent (by weight) alumina.
Intestinal Lactase Activity in the Suckling Rat: Influence of Hypophysectomy and Thyroidectomy
Authors: Yeh Kwo-Yih , Moog Florence
Published: October 2006

Intestinal lactase activity, which is high in the infant rat intestine but falls to a low level by the end of the third week, fails to decline in animals hypophysectomized at the age of 6 days. Treating these animals with thyroxine lowers lactase activity to the control level at 24 days, but cortisone is only partly effective. Thyroidectomy at 6 days also results in persistence of high lactase activity; thyroxine again is more effective than cortisone in reducing activity. The thyroid gland appears to play a previously unsuspected role in intestinal maturation.