bluuebunny/crossref_metadata_2025 huggingface dataset:
Petroleum Hydrocarbons: Uptake and Discharge by the Marine Mussel
Mytilus edulis
Authors: Lee Richard F. , Sauerheber Richard , Benson A. A.
Published: October 2006

The common marine mussel
Mytilus edulis
has been observed to rapidly take up mineral oil, [
14
C]heptadecane, 1,2,3,4-tetrahydronaphthalene, [
14
C]toluene, [
14
C]naphthalene, and [
3
H]3,4-benzopyrene from seawater solution. This species of mussel did not metabolize any of these compounds, and transfer of the mussel to fresh seawater, after exposure to the hydrocarbon in solution, resulted in the discharge of most of the hydrocarbon, although significant amounts remained (between 1 and 400 micrograms per mussel). The nontoxic paraffinic hydrocarbons mineral oil and heptadecane were taken up (10 milligrams per mussel) to a much greater extent than the aromatic hydrocarbons (2 to 20 micrograms per mussel).
Air Lead: Relation to Lead in Blood of Black School Children Deficient in Glucose-6-Phosphate Dehydrogenase
Authors: McIntire Matilda S. , Angle Carol R.
Published: October 2006

Forty-four black children at two elementary schools within 0.7 mile of a battery plant had significantly higher (
P
< .001) concentrations of lead in their bloods (34.1 ± 9.7, micrograms per 100 milliliters, mean ± standard deviation) than 122 students (26.3 ± 7.1) at seven schools 1 to 3 miles distant; 5 months later there was a comparable difference between red cell lead values (54.1 ± 18.5 versus 37.4 ± 12.6). Among the blacks, those deficient in glucose-6-phosphate dehydrogenase had a higher (
P
< .005) concentration of lead in the blood after correction for anemia (32.9 ± 9.7) than the nondeficient (25.7 ± 8.8), and a higher concentration in the red cells (47.3 ± 14.7 as compared to 35.6 ± 15.8,
P
< .001); the enzyme effect was independent of geographic location.
Protein Absorption by the Intestine of the Fetal Rat in Utero
Authors: Lev Robert , Orlic Donald
Published: October 2006

Horseradish peroxidase (molecular weight, about 40,000) injected into the amniotic sacs in pregnant rats has been identified ultrastructurally, 6 to 18 hours later, within the fetal intestine in the absorptive cells and the underlying vascular endothelium. This indicates that macromolecular protein within amniotic fluid swallowed by the fetus can be absorbed and transported by fetal intestine, and may indicate that physiological compounds can be transported by this enteric route to contribute to fetal development.
Contingent Negative Variation as an Indicator of Sexual Object Preference
Authors: Costell Ronald M. , Lunde Donald T. , Kopell Bert S. , Wittner William K.
Published: October 2006

The contingent negative variation (CNV) was recorded in the interval between paired visual exposures of male nudes, female nudes, and sexually "neutral" silhouettes. Groups of 12 male and 12 female subjects viewing 50 randomized presentations from each stimulus category responded with averaged CNV amplitudes proportional to the predicted degree of sexual interest in the stimulus classes.
Abandoned Larvacean Houses: A Unique Food Source in the Pelagic Environment
Authors: Alldredge Alice L.
Published: October 2006

Observations made by using conventional scuba techniques reveal that abandoned larvacean houses serve as food sources for marine, planktonic copepods. Techniques have been developed for photographing these houses in the field for the first time. The abundance of larvacean houses in the open ocean indicates that they are important in pelagic food webs and as a source of particulate organic matter.
Virions from Progressive Multifocal Leukoencephalopathy: Rapid Serological Identification by Electron Microscopy
Authors: Penney J. B. , Weiner L. P. , Herndon R. M. , Narayan O. , Johnson R. T.
Published: October 2006

Virions were extracted directly from the brain of a patient with progressive multifocal leukoencephalopathy (PML). They were treated with antiserum to SV40, with rabbit antiserum to previous PML isolates, or with serum from another patient with the same disease and observed directly by electron microscopy. This procedure could be used for the rapid identification of the antigenic nature of virions in cases of PML.
Lead Aerosol Baseline: Concentration at White Mountain and Laguna Mountain, California
Authors: Chow Tsaihwa J. , Earl John L. , Snyder Carrie B.
Published: October 2006

The lead aerosol concentration at White Mountain, California, may be regarded as the present baseline concentration for atmospheric lead for the continental United States. The seasonal trend of lead aerosols at White Mountain and Laguna Mountain shows a summer maximum and a winter minimum. This is because both mountain sampling sites are well above the thermal (radiation) inversion, which normally occurs in the winter, trapping pollutants below the inversion boundary.
Rous Sarcoma Virus Nucleotide Sequences in Cellular DNA: Measurement by RNA-DNA Hybridization
Authors: Neiman Paul E.
Published: October 2006

Kinetic analysis of the hybridization of 71
S
RNA from Prague strain of Rous sarcoma virus with an excess of DNA from virus induced sarcomas indicated the presence of the majority of the viral genome sequences in cellular DNA with a very low average frequency per cell. About one-third of the viral sequences were at least partially complementary to DNA sequences with a higher average frequency on the order of 50 to 100 per cell. Normal chick embryo DNA was distinctly different, but contained sequences at least partially homologous to some fraction of the viral RNA.
Oyster Herpes-Type Virus
Authors: Farley C. Austin , Banfield William G. , Kasnic George , Foster Walter S.
Published: October 2006

A herpes-type virus infection, the first to be found in an invertebrate animal, is reported in the oyster
Crassostrea virginica
. Intranuclear herpes-type viral inclusions were more prevalent in the oyster at elevated water temperatures of 28° to 30°C than at normal ambient temperatures of 18° to 20°C. The inclusions were associated with a lethal disease at the elevated temperatures.
Uptake and Binding of Uranyl Ions by Barley Roots
Authors: Robards A. W. , Robb Marlene E.
Published: October 2006

After undergoing the processing for electron microscopy, bound uranyl ions are revealed as characteristic electron-opaque crystals. Meristematic walls and associated vesicles become heavily labeled, while pinocytotic accumulation into vacuoles seems probable in cap cells and those just behind the meristem. The endodermal Casparian strip and suberinized lamella are effective barriers to the passage of uranyl ions.
Beggiatoa
: Occurrence in the Rice Rhizosphere
Authors: Pitts G. , Allam A. I. , Hollis J. P.
Published: October 2006

A catalase-like activity surrounding the root tips of rice plants favors the presence of
Beggiatoa,
an organism capable of oxidizing the hydrogen sulfide which is toxic to rice and is found in paddy soil conditions.
Beggiatoa
has now been isolated from rice field soil. A mutually favorable interaction between rice and this bacterium is suggested.
The Apollo 16 Lunar Samples: Petrographic and Chemical Description
Authors:   Apollo 16 Preliminary Examination Team
Published: October 2006

The preliminary characterization of the rocks and soils returned from the Apollo 16 site has substantiated the inference that the lunar terra are commonly underlain by plagioclase-rich or anorthositic rocks. No evidence has been found for volcanic rocks underlying the regolith in the Apollo 16 region. In their place, we have found anorthositic rocks that are thoroughly modified by crushing and partial melting. The textural and chemical variations in these rocks provide some evidence for the existence of anorthositic complexes that have differentiated on a scale of tens to hundreds of meters.

The occurrence of deep-seated or plutonic rocks in place of volcanic or pyroclastic materials at this site suggests that the inference from physiographic evidence that the latter materials are widespread in terra regions may be incorrect.

Several additional, more specific conclusions derived from this preliminary examination are:

1) The combination of data from the Descartes region with data from the orbital x-ray fluorescence experiment indicates that some backside, highland regions are underlain by materials that consist of more than 80 percent plagioclase.

2) The soil or upper regolith between North Ray and South Ray has not been completely homogenized since the time of formation of these craters.

3) The chemistry of the soil indicates that rocks rich in potassium, uranium, and thorium, similar to those that prevail at the Fra Mauro site, are relatively abundant (10 to 20 percent) in the Descartes region.

4) The K/U ratio of the lunar crust is similar to that of the KREEP basalts.

5) The carbon content of the premare lunar crust is even lower than that of the mare volcanic rocks.
Collagen Synthesis in vitro by Embryonic Spinal Cord Epithelium
Authors: Trelstad Robert L. , Kang Andrew H. , Cohen Alan M. , Hay Elizabeth D.
Published: October 2006

Isolated spinal cords from chick embryos (stages 12 to 15) were incubated in vitro with radioactive proline. The proteins synthesized were fractionated by coprecipitation with added carrier collagen, followed by molecularsieve and ion-exchange chromatography. A portion of the isotopically labeled proteins were found to be collagen molecules consisting only of α1 chains.
Experimental Allergic Encephalomyelitis in the Rat: Response to Encephalitogenic Proteins and Peptides
Authors: McFarlin D. E. , Blank S. E. , Kibler R. F. , McKneally S. , Shapira R.
Published: October 2006

Lewis rats were used to determine the encephalitogenic activity of myelin basic protein of different species and of 45-residue fragments of basic protein. Basic protein from guinea pigs was more active than that from rats, and the fragments from the two species showed the same order of activity. Bovine basic protein was the least active of the intact proteins, and the respective fragment was inactive. Studies of serum-binding capacity did not support the hypothesis that blocking antibody played a role in this biological variation, whereas consideration of the amino acid sequences of the three fragments suggested that differences in primary structure, operating either at the sensitization or the effector phase of the immune response, could account for the variation.
Lack of Tolerance to Δ
9
-Tetrahydrocannabinol in Chimpanzees
Authors: Ferraro Douglas P. , Grilly David M.
Published: October 2006

Five chimpanzees were given Δ
9
-tetrahydrocannabinol (Δ
9
THC): 1.0 milligram per kilogram of body weight for 21 days and 4.0 milligrams per kilogram of body weight for 42 days. Although accuracy and speed of performance on a delayed matching-to-sample task were significantly affected by both doses, tolerance to Δ
9
THC did not develop. No long-term behavioral effects of Δ
9
THC were observed after termination of the drug regimens.
Motor Cortex Reflexes Associated with Learned Movement
Authors: Evarts Edward V.
Published: October 2006

In primates, sensory input can generate reflex motor cortex output in association with learned movement when the sensory input has a strong and direct connection to the motor cortex—for example, when a stimulus calling for repositioning of the hand consists of a perturbation of hand position. This finding supports the proposal that neurons of primate motor cortex may function in a transcortical servo-loop.
Bubble Formation in Physical and Biological Systems: A Manifestation of Counterdiffusion in Composite Media
Authors: Graves D. J. , Idicula J. , Lambertsen C. J. , Quinn J. A.
Published: October 2006

The counterdiffusion of gases across a composite layer can lead to supersaturation and development of bubbles within the layer. A physicochemical model has been derived to predict the extent of such supersaturation; experiments with inert liquid layers confirm predictions. These findings explain the evolution of cutaneous lesions observed in man during simulated deep-sea dives and the cutaneous lesions and intravascular bubbles experimentally induced in pigs by exchanging certain inert gases across the skin. The phenomena associated with counterdiffusion have widespread physical and biological implications.
Familial Hypophosphatemic Rickets: Defective Transport of Inorganic Phosphate by Intestinal Mucosa
Authors: Short Elizabeth M. , Binder Henry J. , Rosenberg Leon E.
Published: October 2006

Uptake of inorganic phosphate is impaired in intestinal mucosa from hemizygous males and heterozygous females with X-linked familial hypophosphatemic rickets. Considerable intrafamilial and interfamilial variation in uptake of inorganic phosphate is observed in affected patients. Uptake by normal mucosa is concentrative and energy-dependent, and is mediated by at least two systems with widely different affinities. These results lend direct support to the thesis that the primary metabolic disturbance in this disease results from impaired transport of inorganic phosphate in kidney and gut.
Directionality of Rewarding Impulses within the Medial Forebrain Bundle Self-Stimulation System of the Rat
Authors: German Dwight C. , Holloway Frank A.
Published: October 2006

Self-stimulation performance of rats was tested with conditioning pulses to the anterior preoptic area of the medial forebrain bundle followed at various intervals by test pulses to the contralateral posterior hypothalamic area of this bundle. Alternatively, conditioning pulses were delivered through the posterior electrode and test pulses were sent through the anterior electrode. The animals' performance in these two test sequences was indicative of (i) synaptic facilitation and (ii) a posterior convergence site of "self-stimulation impulses" in the medial forebrain bundle.
Lunar Cinder Cones
Authors: McGetchin Thomas R. , Head James W.
Published: October 2006

Data on terrestrial eruptions of pyroclastic material and ballistic considerations suggest that in the lunar environment (vacuum and reduced gravity) low-rimmed pyroclastic rings are formed rather than the high-rimmed cinder cones so abundant on the earth. Dark blanketing deposits in the Taurus-Littrow region (Apollo 17 landing area) are interpreted as being at least partly composed of lunar counterparts of terrestrial cinder cones.
Unilateral Cortical Activity in Newborn Humans: An Early Index of Cerebral Dominance?
Authors: Crowell. David H. , Jones Richard H. , Kapuniai Linda E. , Nakagawa Joann K.
Published: October 2006

Spectral analyses show unilateral photic driving in newborn human infants to bilateral repetitive visual stimulation. Results are interpreted as evidence of dominance in the right hemisphere for rhythmic visual stimuli and lack of interhemispheric integration.
Shape and Nature of Small Sedimentary Quartz Particles
Authors: Krinsley D. H. , Smalley I. J.
Published: October 2006

Quartz particles in sediments become flatter with decreasing size; a cleavage mechanism may operate below the critical size of about 100 microns. Flat particles would tend to form a more open packing than spherical particles, and this may contribute to the collapse of loess and similar soils and the sudden loss of strength observed in "sensitive" clay soils.
Sarcocystis in Mice Inoculated with
Toxoplasma
-Like Oocysts from Cat Feces
Authors: Wallace Gordon D.
Published: October 2006

Sarcocysts morphologically similar to
Sarcocystis muris
were observed in mice after inoculation with
Toxoplasma
-like oocysts found in feces of a stray cat. Cats that were fed mice infected with the oocysts shed similar oocysts in their feces. Sarcocysts were found histologically in about 50 percent of mice inoculated with 40,000 or more oocysts and examined 42 days or longer after exposure. Most inoculated mice developed low
Toxoplasma
dye-test antibody titers 3 to 4 weeks after exposure, but
Toxoplasma
antibody was usually not detectable in infected cats.
Lead Inclusion Bodies in Osteoclasts
Authors: Hsu F. S. , Krook L. , Shively J. N. , Duncan J. R. , Pond W. G.
Published: October 2006

Inclusion bodies occur frequently in the nuclei and rarely in the cytoplasm of
osteoclasts in pigs with experimental lead poisoning. The light and electron microscope
pictures of undemineralized sections are similar to those described for liver cord cells
and renal tubular cells.
Speed-Accuracy Trade-Off in Recognition Memory
Authors: Reed Adam V.
Published: October 2006

In a recognition memory experiment, the time allowed for retrieval was controlled by using the offset of the probe as a signal to terminate retrieval and respond. The response latencies measured in the experiment indicate that this procedure effectively eliminated fast-guess strategies. The recognition signal-to-noise ratio,
d
′, rows at a negatively accelerated rate as the allowed retrieval time is increased from 0.5 second to 1 and 2 seconds.
Membrane Structure: Some General Principles
Authors: Bretscher Mark S.
Published: October 2006

The arrangement of lipids and some proteins in the erythrocyte membrane has been discussed. The conclusions from this are listed here as a set of general guidelines for the structure of membranes of higher organisms: some of these rules may be wrong. But at this stage it seems useful to sharpen our thoughts in this way and thereby focus attention on various specific points.

1) The basis of a membrane is a lipid bilayer with (i) choline phospholipids and glycolipids in the external half and (ii) amino (and possibly some choline) phospholipids in the cytoplasmic half. There is effectively no lipid exchange across the bilayer (unless enzymatically catalyzed).

2) Some proteins extend across the bilayer. Where this is so, they will in general have carbohydrate on their surface remote from the cytoplasm. This carbohydrate may prevent the protein diffusing out of the membrane into the cytoplasm; it acts as a lock on the protein.

3) Just as lipids do not flip-flop, proteins do not rotate across the membrane. Lateral motion or rotation of lipids and proteins in the plane of the bilayer may be expected.

4) Most membrane protein is associated with the inner, cytoplasmic, surface of the membrane. Proteins are not usually associated exclusively with the outer half of the lipid bilayer.

5) Membrane proteins are a special class of cytoplasmic proteins, not of secreted proteins.
Insect Sex Pheromones: Minor Amount of Opposite Geometrical Isomer Critical to Attraction
Authors: Klun Jerome A. , Chapman O. L. , Mattes K. C. , Wojtkowski P. W. , Beroza Morton , Sonnet P. E.
Published: October 2006

(
Z
)-II-Tetradecenyl acetate is the reported sex pheromone of European corn borer and redbanded leafroller moths. However, geometrically pure preparations of the compound are weakly attractive to these species. Presence of the
E
geometrical isomer in the
Z
is necessary for maximum sex attraction and these moths are "tuned" to respond optimally to specific proportions of
Z
to
E
. This discovery is important to considerations of moth pheromonal specificity, evolution, and in application of knowledge of the pheromones to insect-pest suppression.
Selective in Vitro Growth of T Lymphocytes from Normal Human Bone Marrows
Authors: Morgan Doris Anne , Ruscetti Francis W. , Gallo Robert
Published: October 2006

Selective growth of T lymphocytes occurred when unfractionated normal human bone marrow cells were cultured with conditioned medium obtained from phytohemagglutinin-stimulated normal human lymphocytes (Ly-CM). Cultures of up to 90 percent T cells have been maintained for more than 9 months. The T cells exhibited a strict growth dependence upon Ly-CM and were consistently negative for Epstein-Barr viral information.
Gamma-Aminobutyric Acid Antagonism in Visual Cortex: Different Effects on Simple, Complex, and Hypercomplex Neurons
Authors: Pettigrew J. D. , Daniels J. D.
Published: October 2006

Intravenous bicuculline was used to examine how removing gamma-aminobutyric acid-mediated inhibition affects the visual response properties of single cortical neurons. Simple neurons were depressed and complex neurons showed increase in the vigor and range of responses. Hypercomplex cells were no longer inhibited by elongated stimuli. The results are consistent with present evidence concerning the origin and distribution of inhibitory connections within the cortex.
Neural Correlate of Perceptual Adaptation to Gratings
Authors: Maffei L. , Fiorentini A. , Bisti S.
Published: October 2006

Exposure of simple cells of the cat striate cortex to high-contrast drifting gratings greatly reduces the subsequent response of the cells to low-contrast gratings. This adaptation effect has an average duration of 30 seconds and shows interocular transfer and selectivity for spatial frequency and orientation. This effect is strikingly similar to the perceptual adaptation to high-contrast gratings.
Microwave Spectrometer on the Nimbus 5 Satellite: Meteorological and Geophysical Data
Authors: Staelin D. H. , Barrett A. H. , Waters J. W. , Barath F. T. , Johnston E. J. , Rosenkranz P. W. , Gaut N. E. , Lenoir W. B.
Published: October 2006

The Nimbus 5 microwave spectrometer has been used to measure thermal radiation in five frequency bands between 22.235 and 58.8 gigahertz, and has yielded both the temperature profile and, over ocean, the vapor and liquid water content of the terrestrial atmosphere, even in overcast conditions. Information has also been obtained on geophysical parameters that affect the surface emissivity, such as ice type, sea roughness, and snow cover. The experiment demonstrates the considerable potential of passive microwave sensing of meteorological and geophysical parameters.
Distributed Relaxation Processes in Sensory Adaptation
Authors: Thorson John , Biederman-Thorson Marguerite
Published: October 2006

Dynamic description of most receptors, even in their near-linear ranges, has not led to understanding of the underlying physical events—in many instances because their curious transfer functions are not found in the usual repertoire of integral-order control-system analysis. We have described some methods, borrowed from other fields, which allow one to map any linear frequency response onto a putative weighting over an ensemble of simpler relaxation processes. One can then ask whether the resultant weighting of such processes suggests a corresponding plausible distribution of values for an appropriate physical variable within the sensory transducer.

To illustrate this approach, we have chosen the fractional-order low-frequency response of
Limulus
lateral-eye photoreceptors. We show first that the current "adapting-bump" hypothesis for the generator potential can be formulated in terms of local first-order relaxation processes in which local light flux, the cross section of rhodopsin for photon capture, and restoration rate of local conductance-changing capability play specific roles. A representative spatial distribution for one of these parameters, which just accounts for the low-frequency response of the receptor, is then derived and its relation to cellular properties and recent experiments is examined.

Finally, we show that for such a system, nonintegral-order dynamics are equivalent to nonhyperbolic statics, and that the efficacy distribution derived to account for the small-signal dynamics in fact predicts several decades of near-logarithmic response in the steady state.

Encouraged by the result that one plausible proposal can account approximately for both the low-frequency dynamics (the transfer function
s
k
) and the range-compressing statics (the Weber-Fechner relationship) measured in this photoreceptor, we have described some formally similar applications of these distributed effects to the vertebrate retina and to analogous properties of mechanoreceptors and chemoreceptors.
Ethane Evolution: A New Index of Lipid Peroxidation
Authors: Riely Caroline A. , Cohen Gerald , Lieberman Morris
Published: October 2006

Homogenates of mouse liver and brain at 37°C spontaneously formed lipid peroxides and simultaneously evolved ethane. α-Tocopherol, a lipid antioxidant, blocked ethane formation. When mice were injected with carbon tetrachloride (a liquid prooxidant for liver), the animals produced ethane. Ethane evolution in vivo was stimulated by prior administration of phenobarbital and it was diminished by prior injection of α-tocopherol. These data suggest that ethane production may be a useful index of lipid peroxidation in tissue homogenates and in intact animals.
Suppression of Nitrogen Fixation by Blue-Green Algae in a Eutrophic Lake with Trace Additions of Copper
Authors: Horne Alexander J. , Goldman Charles R.
Published: October 2006

Nitrogen fixation by blue-green algae in highly eutrophic Clear Lake, California, was severely inhibited by trace amounts of copper. The chelation capacity of the lake is probably saturated by indigenous copper. Additions were only 1/200 of those normally used in algal control. Since nitrogen fixation provides half of the lake's annual nitrogen budget, economical eutrophication control appears possible.
Cerebroside Antibody Inhibits Sulfatide Synthesis and Myelination and Demyelinates in Cord Tissue Cultures
Authors: Fry June M. , Weissbarth Sulamith , Lehrer Gerard M. , Bornstein Murray B.
Published: October 2006

Antiserum to cerebroside was prepared in rabbits by injection of cerebroside together with bovine serum albumin in complete Freund's adjuvant. When applied to cultures of embryo mouse spinal cord at explantation, this antiserum inhibited sulfatide synthesis and myelination; when applied to myelinated cultures it inhibited sulfatide synthesis and produced demyelination. Complement fixation assays also show antibody to cerebroside in serums from rabbits with experimental allergic encephalomyelitis induced by injection of whole white matter. Absorption of such serum with cerebroside abolishes the inhibiting and demyelinating activities.
Operant Control of Occipital Theta Rhythm Affects Performance in a Radar Monitoring Task
Authors: Beatty Jackson , Greenberg Arana , Deibler W. Phillip , O'Hanlon James F.
Published: October 2006

Detection efficiency of human observers deteriorates rapidly in monotonous monitoring tasks; this effect (the vigilance decrement) has been associated with increased theta band activity in the electroencephalogram. Suppression of theta activity by operant methods enhances monitoring efficiency, whereas theta augmentation further degrades task performance. These results demonstrate a lawful relationship between operantly regulated cortical activity and behavior in man.
Amino Acid Sequence of Rabbit Muscle Aldolase and the Structure of the Active Center
Authors: Lai C. Y. , Nakai N. , Chang D.
Published: October 2006

Elucidation of the amino acid sequence of fructose-1,6-bis-phosphate aldolase from rabbit muscle has made it possible to assign the positions of the functional groups known to play specific roles in the catalytic activity, and also to locate the buried, exposed, and active site cysteine residues. The results indicate that the middle portion of the polypeptide chain, including Cys-134, Cys-149, Cys-177, and Cys-199, is buried in the native structure, with regions containing Cys-72, Lys-107, Lys-227, Cys-336, His-359, and the COOH-terminal residue (Tyr-361) folded into the active center of the enzyme, at or near the surface of the enzyme molecule.
Mariner 10 Venus Encounter
Authors: Dunne James A.
Published: October 2006

The Mariner 10 spacecraft encountered Venus at 1701 G.M.T. on 5 February 1974. The preplanned encounter science sequence was executed satisfactorily, accomplishing all objectives despite a number of spacecraft problems that had occurred in the early phases of the flight. Seven experiments were conducted, including observations of the solar wind interaction region, extreme ultraviolet and infrared emissions, radio occultation, and imaging.
Regulation of Phagocytosis and [Ca
2+
]
i
Flux by Distinct Regions of an Fc Receptor
Authors: Odin Joseph A. , Edberg Jeffrey C. , Painter Catherine J. , Kimberly Robert P. , Unkeless Jay C.
Published: October 2006

The binding of multivalent immunoglobulin G complexes to Fc receptors (Fc
γ
Rs) on macrophages activates multiple immune functions. A murine macrophage cell line, but not a fibroblast cell line, that was transfected with human Fc
γ
RIIA mediated phagocytosis and an intracellular Ca
2+
concentration ([Ca
2+
]
i
) flux upon cross-linking of human Fc
γ
RIIA. Transfected macrophages that expressed a truncated receptor lacking 17 carboxy-terminal amino acids phagocytosed small antibody complexes. However, only wild-type transfectants phagocytosed labeled erythrocytes and fluxed [Ca
2+
]
i
. Thus, the cytoplasmic domain of human Fc
γ
RIIA contains distinct functional regions.
Myelin Basic Protein: Location of Multiple Independent Antigenic Regions
Authors: Driscoll Bernard F. , Kramer Allan J. , Kies Marian W.
Published: October 2006

Immunization of guinea pigs with homologous myelin basic protein induces antibodies that differ in their ability to bind specific peptide fragments of the protein. Antiserums with differing specificities made it possible to demonstrate at least three mutually exclusive antigenic sites in the protein molecule. One of these sites is located between residues 44 and 89, another between 90 and 116, and the third between 117 and 170.
Augmentation of Bone Repair by Inductively Coupled Electromagnetic Fields
Authors: Andrew C. , Bassett L. , Pawluk Robert J. , Pilla Arthur A.
Published: October 2006

Pulsing electromagnetic fields of low frequency and strength have been inductively coupled across skin, directly to bone, to enhance the repair of canine osteotomies. The induced voltage field in bone appears to increase the organization and strength of the repair process at 28 days after "fracture."
Meteoric Water in Magmas
Authors: Friedman Irving , Lipman Peter W. , Obradovich John D. , Gleason Jim D. , Christiansen Robert L.
Published: October 2006

Oxygen isotope analyses of sanidine phenocrysts from rhyolitic sequences in Nevada, Colorado, and the Yellowstone Plateau volcanic field show that δ
18
O decreased in these magmas as a function of time. This decrease in δ
18
O may have been caused by isotopic exchange between the magma and groundwater low in
18
O. For the Yellowstone Plateau rhyolites, 7000 cubic kilometers of magma could decrease in δ
18
O by 2 per mil in 600,000 years by reacting with water equivalent to 3 millimeters of precipitation per year, which is only 0.3 percent of the present annual precipitation in this region. The possibility of reaction between large magmatic bodies and meteoric water at liquidus temperatures has major implications in the possible differentiation history of the magma and in the generation of ore deposits.
Perception of Letters in Words: Seek Not and Ye Shall Find
Authors: Johnston James C. , McClelland James L.
Published: October 2006

Subjects perceive a letter in a briefly presented word more accurately when they attend to the whole word than when they focus their attention on just the letter they want to see.
Microbodies (Peroxisomes) Containing Catalase in Myocardium: Morphological and Biochemical Evidence
Authors: Herzog Volker , Fahimi H. Dariush
Published: October 2006

Microbodies characterized by a single limiting membrane and finely granular matrix occur in mouse myocardium and appear in close spatial relation to mitochondria and sarcoplasmic reticulum. The presence of catalase in the microbodies is revealed cytochemically and confirmed biochemically by direct measurement of its activity in myocardial tissue fractions. It is suggested that the microbodies may play an important role in myocardial lipid metabolism.
Sodium: Stimulus for Puddling Behavior by Tiger Swallowtail Butterflies,
Papilio glaucus
Authors: Arms Karen , Feeny Paul , Lederhouse Robert C.
Published: October 2006

Male
Papilio glaucus
butterflies are attracted to sand soaked with dilute aqueous solutions of sodium salts. A sodium ion concentration of 10
-3
molar is sufficient to stimulate puddling behavior. Acquisition of sodium may be the main ecological function of puddling behavior.
Sea Otters: Their Role in Structuring Nearshore Communities
Authors: Estes James A. , Palmisano John F.
Published: October 2006

A comparison of western Aleutian Islands with and without sea otter populations shows that this species is important in determining littoral and sublittoral community structure. Sea otters control herbivorous invertebrate populations. Removal of sea otters causes increased herbivory and ultimately results in the destruction of macrophyte associations. The observations suggest that sea otter reestablishment indirectly affects island fauna associated with macrophyte primary productivity.
The Control of Oxidant Stress at Fertilization
Authors: Shapiro Bennett M.
Published: October 2006

Metazoan eggs alter their coats after fertilization to protect the early embryo. In sea urchins, this modification consists of a rapid, coordinated set of noncovalent macromolecular assembly steps that are stabilized by protein cross-linking. The sea urchin egg uses an oxidative cross-linking reaction that requires hydrogen peroxide and a secreted peroxidase and thus faces the challenge of oxidant stress at the beginning of its development. Protection from the deleterious effects of this oxidative mechanism is afforded by regulation of the production and utilization of oxidizing species. This regulation requires a specific protein kinase C-activated oxidase and ovothiol, an intracellular antioxidant.
Clusters of Coupled Neuroblasts in Embryonic Neocortex
Authors: Lo Turco Joseph J. , Kriegstein Arnold R.
Published: October 2006

The neocortex of the brain develops from a simple germinal layer into a complex multilayer structure. To investigate cellular interactions during early neocortical development, whole-cell patch clamp recordings were made from neuroblasts in the ventricular zone of fetal rats. During early corticogenesis, neuroblasts are physiologically coupled by gap junctions into clusters of 15 to 90 cells. The coupled cells form columns within the ventricular zone and, by virtue of their membership in clusters, have low apparent membrane resistances and generate large responses to the inhibitory neurotransmitter γ-aminobutyric acid. As neuronal migration out of the ventricular zone progresses, the number of cells within the clusters decreases. These clusters allow direct cell to cell interaction at the earliest stages of corticogenesis.
OPC-21268, an Orally Effective, Nonpeptide Vasopressin V1 Receptor Antagonist
Authors: Yamamura Yoshitaka , Ogawa Hidenori , Chihara Tomihiko , Kondo Kazumi , Onogawa Toshiyuki , Nakamura Shigeki , Mori Toyoki , Tominaga Michiaki , Yabuuchi Youichi
Published: October 2006

An orally effective, nonpeptide, vasopressin V1 receptor antagonist, OPC-21268, has been identified. This compound selectively antagonized binding to the V1 subtype of the vasopressin receptor in a competitive manner. In vivo, the compound acted as a specific antagonist of arginine vasopressin (AVP)-induced vasoconstriction. After oral administration in conscious rats, the compound also antagonized pressor responses to AVP. OPC-21268 can be used to study the physiological role of AVP and may be therapeutically useful in the treatment of hypertension and congestive heart failure.
Vascular and Brain Dopamine β-Hydroxylase Activity in Young Spontaneously Hypertensive Rats
Authors: Nagatsu Toshiharu , Ikuta Keiko , Numata Yukiko , Kato Takeshi , Sano Masao , Nagatsu Ikuko , Umezawa Hamao , Matsuzaki Meiki , Takeuchi Tomio
Published: October 2006

Dopamine β-hydroxylase activity was higher in mesenteric vessels, adrenal glands, and serum of 3-week-old spontaneously hypertensive rats but lower in the locus coeruleus than it was in the control Wistar-Kyoto rats. The results support the concept that the nervous system is an important regulator of blood pressure.
Serum Globulin in Myasthenia Gravis: Inhibition of α-Bungarotoxin Binding to Acetylcholine Receptors
Authors: Almon Richard R. , Andrew Clifford G. , Appel Stanley H.
Published: October 2006

Serum factors that inhibit the binding of
125
I-labeled α-bungarotoxin to the acetylcholine receptor extracted in detergent from denervated rat muscle were detected by a sensitive assay. The serum of at least 5 and possibly 11 out of 15 patients with myasthenia gravis showed inhibitory activity that was localized to the globulin fraction. No controls showed inhibitory activity. The demonstration of inhibitory globulins may help explain the involvement of the immune system in the pathophysiology of the neuromuscular junction in patients with myasthenia gravis.
The Temperature Gradient in the Solar Nebula
Authors: Lewis John S.
Published: October 2006

The available compositional data on planets and satellites can be used to place stringent limits on the thermal environment in the solar nebula. The densities of the terrestrial planets, Ceres and Vesta, the Galilean satellites, and Titan; the atmospheric compositions of several of these bodies; and geochemical and geophysical data on the earth combine to define a strong dependence of formation temperature on heliocentric distance. The pressure and temperature dependences of the condensation process are separable in the sense that the variation of the deduced formation temperatures with heliocentric distance is insensitive to even very diverse assumptions regarding the pressure profile in the nebula. It is impossible to reconcile the available compositional data with any model in which the formation temperatures of these bodies are determined by radiative equilibrium with the sun, regardless of the sun's luminosity. Rather, the data support Cameron's hypothesis of a dense, convective solar nebula, opaque to solar radiation, with an adiabatic temperature-pressure profile.
Visual Detection of Line Segments: An Object-Superiority Effect
Authors: Weisstein Naomi , Harris Charles S.
Published: October 2006

Observers identified a briefly flashed line segment more accurately when it was part of a drawing that looked unitary and three-dimensional than when the line was in one of several less coherent flat designs.
DNA Ligase: Structure, Mechanism, and Function
Authors: Lehman I. R.
Published: October 2006

DNA ligase of
E. coli
is a single polypeptide of molecular weight 75,000. The comparable T4-induced enzyme is somewhat smaller (63,000 to 68,000). Both enzymes catalyze the synthesis of phosphodiester bonds between adjacent 5′-phosphoryl and 3′-hydroxyl groups in nicked duplex DNA, coupled to the cleavage of the pyrophosphate bond of DPN (
E. coli
) or ATP (T4). Phosphodiester bond synthesis catalyzed by both enzymes occurs in a series of these discrete steps and involves the participation of two covalent intermediates (Fig. 1). A steady state kinetic analysis of the reaction-catalyzed
E. coli
ligase supports this mechanism, and further demonstrates that enzyme-adenylate and DNA-adenylate are kinetically significant intermediates on the direct path of phosphodiester bond synthesis.

A strain of
E. coli
with a mutation in the structural gene for DNA ligase which results in the synthesis of an abnormally thermolabile enzyme is inviable at 42°C. Although able to grow at 30°C, the mutant is still defective at this temperature in its ability to repair damage to its DNA caused by ultraviolet irradiation and by alkylating agents. At 42°C, all the newly replicated DNA is in the form of short 10
S
"Okazaki fragments," an indication that the reason for the mutant's failure to survive under these conditions is its inability to sustain the ligation step that is essential for the discontinuous synthesis of the
E. coli
chromosome. DNA ligase is therefore an essential enzyme required for normal DNA replication and repair in
E. coli
. Purified DNA ligases have proved to be useful reagents in the construction in vitro of recombinant DNA molecules.
Sea-Level Solar Radiation in the Biologically Active Spectrum
Authors: Halpern Paul , Dave J. V. , Braslau Norman
Published: October 2006

Calculations show a significant depletion of ultraviolet and visible radiation due to absorption and scattering by particulates and cloud drops for a fixed amount of ozone.
Innate Recognition of Coral Snake Pattern by a Possible Avian Predator
Authors: Smith Susan M.
Published: October 2006

Inexperienced hand-reared motmots avoided a pattern of red and yellow rings but readily attacked a pattern of green and blue rings and also one of red and yellow stripes. The motmots' avoidance of the "coral snake" pattern indicates that mimic snake species can derive protection from some potential predators.
Environmental Impact of a Geothermal Power Plant
Authors: Axtmann Robert C.
Published: October 2006

The Wairakei plant discharges approximately 6.5 times as much heat, 5.5 times as much water vapor, and 0.5 times as much sulfur, per unit of power produced, as would a modern coal plant in New Zealand. It also contaminates the Waikato River with H
2
S, CO
2
, arsenic, and mercury at concentrations that have adverse but not calamitous effects. Designed and built at a time when environmental sensibilities were less acute and geothermal technology was less developed, Wairakei produces an overall environmental impact that would be neither acceptable nor necessary in a new plant. Despite its imperfections, however, the Wairakei plant has been under development or in operation for more than 20 years without presenting any serious environmental problems for the local population. Reinjection of the hot waste water, an as yet unproven procedure for liquid-dominated fields, would reduce the plant's environmental impact sharply. Ground subsidence is not a severe problem at Wairakei but may prove to be one at the nearby Broadlands field.

There are several environmental characteristics that are unique to geothermal power: (i) pollutant formation may be independent of the power productionc rate; (ii) effluent pathways may change abruptly; (iii) preoperational testing and wild bores contribute significantly to the overall impact; and (iv) waste water may be discharged at temperatures high enough so that utilization of the waste heat becomes both practical and imperative.
Deep-Sea Erosion and Manganese Nodule Development in the Southeast Indian Ocean
Authors: Kennett J. P. , Watkins N. D.
Published: October 2006

Features exhibited by a large number of sea floor photographs together with the dating of 187 sediment cores from the southeast Indian Ocean have revealed extensive manganese nodule development and sediment erosion in deep basinal areas. The most extensive nodule field, with an area of 10
6
square kilometers, occurs in the northwestern sector of the South Australian Basin and is named the Southeast Indian Ocean Manganese Pavement. The crests and flanks of the adjacent mid-ocean ridge are, in contrast, free of nodules and marked by much less dynamic bottom water conditions.
Kinetics of the Fe
2+
-Mg, Order-Disorder Reaction in Anthophyllites: Quantitative Cooling Rates
Authors: Seifert Friedrich A. , Virgo David
Published: October 2006

The kinetics of the Fe
2+
-Mg, order-disorder phenomenon in a highly ordered natural anthophyllite have been determined over the temperature range from 400° to 720°C at a pressure of 2 kilobars. At temperatures of 600°C and above, equilibrium is attained by disordering as well as ordering reactions. The intracrystalline exchange is defined by a standard Gibbs free energy of 4247 ± 54 calories per formula unit. Rate studies at 550° and 500°C show that equilibrium is attained by ordering but not by disordering within the same time scale and that the exchange reaction is characterized by an activation energy of ∼55 kilocalories per formula unit. An equilibration temperature for the natural anthophyllite of 270°C is determined from the termination of the ordering process owing to excessively slow reaction kinetics after ∼10
7
years. From the rate constants of the exchange process, for different crystallization temperatures, the apparent equilibration temperature of 270°C defines a maximum linear cooling rate for the rock of 1 × 10
4
°C per year.
Energy and Resources
Authors: Sørensen Bent
Published: October 2006

Two possible futures for the industrial world may be distinguished: (i) Large amounts of low-cost energy become available and the more energy-intensive methods for extracting resources from lower-grade deposits continue to sustain industrial expansion until either the environmental impact becomes unacceptable or ultimate limits, such as climate disruptions, put an end to such growth. (ii) The cost of nonrenewable energy resources continue to rise, but a fixed amount of energy from continuous sources may be utilized at constant cost. In this case a lower production level may be set by the amount of energy that is available from renewable sources, and society may thus have to be reshaped with energy economization in focus. If it is possible to choose between these two alternatives, the choice should be based on a discussion of the pros and cons of each one, and in particular on the desirability of having to process an increasing fraction of the earth's crust in search of raw materials in order to maintain growth as long as possible. However, the availability, of the first option is far from certain and it thus seems reasonable to plan for the second alternative.

I have tried to propose such a plan for a small, homogeneous geographical region, namely Denmark. The ceiling on the consumption of energy from continuous sources is chosen in accordance with the criterion of not having to convert a major part of the land area to energy-collecting systems. The proposed annual average energy consumption of 19 gigawatts by the year 2050 corresponds to solar energy collecting panels (in use only 50 percent of the time) with an area of roughly 180 square kilometers and a windmill swept area of about 150 square kilometers. These (vertical) areas constitute less than 1 percent of the total land area.

The selection of solar or wind energy for different applications has been based on known technology and may be subject to adjustments. The project has been shown to be economically feasible according to estimates of the cost of various alternatives during the 25-year depreciation period adopted. However, the initial cost per energy unit produced is higher than that for most of the alternatives, so that action is not expected to be taken immediately as a result of purely private initiative. In a public economic evaluation, other factors must be considered in addition to the cost of energy per kilowatt-hour. At present, Denmark has over 10 percent of its labor force out of employment and a substantial deficit on its balance of payments, so that an early start on the solar and wind energy project, based on national industry, would have additional payoffs compared with energy systems based on imported technology or imported fuels. Several factories that are now being closed down as a result of the economic crisis could be adapted to the production of parts for solar or wind power systems, and the building industry, badly hit by unemployment, would receive legitimate work.
Top Predators in the Southern Ocean: A Major Leak in the Biological Carbon Pump
Authors: Huntley M. E. , Lopez M. D. , Karl D. M.
Published: October 2006

Primary productivity in the Southern Ocean is approximately 3.5 gigatons of carbon per year, which accounts for nearly 15 percent of the global total. The presence of high concentrations of nitrate in Antarctic waters suggests that it might be possible to increase primary production significantly and thereby alleviate the net accumulation of atmospheric carbon dioxide. An analysis of the food web for these waters implies that the Southern Ocean may be remarkably inefficient as a carbon sink. This inefficiency is caused by the large flux of carbon respired to the atmosphere by air-breathing birds and mammals, dominant predators in the unusually simple food web of Antarctic waters. These top predators may transfer into the atmosphere as much as 20 to 25 percent of photosynthetically fixed carbon.