bluuebunny/crossref_metadata_2025 huggingface dataset:
Neuronal Activity in Narcolepsy: Identification of Cataplexy-Related Cells in the Medial Medulla
Authors: Siegel Jerome M. , Nienhuis Robert , Fahringer Heidi M. , Paul Richard , Shiromani Priyattam , Dement William C. , Mignot Emmanuel , Chiu Charles
Published: October 2006

Narcolepsy is a neurological disorder characterized by sleepiness and episodes of cataplexy. Cataplexy is an abrupt loss of muscle tone, most often triggered by sudden, strong emotions. A subset of cells in the medial medulla of the narcoleptic dog discharged at high rates only in cataplexy and rapid eye movement (REM) sleep. These cells were noncholinergic and were localized to ventromedial and caudal portions of the nucleus magnocellularis. The localization and discharge pattern of these cells indicate that cataplexy results from a triggering in waking of the neurons responsible for the suppression of muscle tone in REM sleep. However, most medullary cells were inactive during cataplexy but were active during REM sleep. These data demonstrate that cataplexy is a distinct behavioral state, differing from other sleep and waking states in its pattern of brainstem neuronal activity.
Detection of Somatic DNA Recombination in the Transgenic Mouse Brain
Authors: Matsuoka Masao , Nagawa Fumikiyo , Okazaki Kenji , Kingsbury Linda , Yoshida Kazuya , Müller Urs , Larue David T. , Winer Jeffery A. , Sakano Hitoshi
Published: October 2006

A DNA construct containing the bacterial β-galactosidase gene (
lacZ
) was used to study somatic DNA recombination in the transgenic mouse brain. Recombination-positive areas of the adult brain were stained blue with X-gal, a substrate of β-galactosidase. Blue-colored cells appeared soon after birth, and continued to emerge in postnatal tissue. Staining was prominent in sensory as opposed to motor regions of the brain, and was present in more than 70 discrete areas of the nervous system. The possibility of DNA rearrangement is discussed with respect to the development of the central nervous system.
Jupiter's Spectrum Between 12 and 24 Micrometers
Authors: Aumann H. H. , Orton G. S.
Published: October 2006

Spectroscopic measurements of the thermal radiation from Jupiter between 12 and 24 micrometers (420 to 840 reciprocal centimeters) with a resolution of 4 reciprocal centimeters are used to infer the Jovian temperature structure in the pressure region 0.1 to 0.4 atmosphere. The brightness temperature spectrum is in good agreement with previous ground-based measurements between 11 and 13 micrometers and with airborne measurements between 18 and 25 micrometers. However, the integrated flux calculated for a filter window and viewing angle equivalent to those of the 20 micrometer channel of Pioneer 10 is 20 percent below that measured by the Pioneer infrared radiometer. The Q branch of the ν
5
fundamental band of acetylene at 730 reciprocal centimeters appears in emission and leads to a mixing ratio estimate of 10
–6 ± 0.5
.
Halictine Social Evolution: The Australian Enigma
Authors: Knerer Gerd , Schwarz Michael
Published: October 2006

Australian halictines belong to the primitive genus
Lasioglossum
or related subgenera. The underground nests have lined cells in series or clusters and sometimes at the end of laterals. Two full generations per year are produced in the communal nests. Overwintered and newly emerged females form unique "pseudosocieties" rather than matrifilial societies along Holarctic patterns. Several
Chilalictus
species produce a "male caste" of big-headed, flightless males, in addition to normal individuals. Oviposition of unfertilized eggs on large pollen balls causes such allometric bees.
Mammal Teeth from the Forest Marble (Middle Jurassic) of Oxfordshire, England
Authors: Freeman Eric F.
Published: October 2006

A very early stage in the evolution of the talonid basin is seen in a eupantothere lower molar from the Upper Bathonian of central England. The corresponding upper molars and the first known Middle Jurassic morganucodontid, kuehneotheriid, and dryolestid teeth are briefly described and illustrated.
Pleistocene Volcanism and Glacial Initiation
Authors: Bray J. R.
Published: October 2006

During the past 2 million years, major Northern Hemisphere eruptions occurred within 0.01 million years before 22 of 24 maximum-temperature dates which preceded the ten European glacial stages and 42 of 60 maximum-temperature dates which preceded the 22 cooling episodes. Massive eruptions were even more closely associated with the glacial stages and the cooling episodes. Within the errors of Pleistocene dating, major eruptions apparently occurred at the crucial moments to have triggered each of the ice ages.
Soil Deterioration and the Growing World Demand for Food
Authors: Brink R. A. , Densmore J. W. , Hill G. A.
Published: October 2006

A recent survey of five watersheds in south-central Wisconsin, where corn is now the dominant annual crop, illustrates the soil erosion damage that is occurring on sloping land under modern agricultural technology and prevailing market forces. In 70 percent of the 93 quarter-sections sampled, estimated soil losses, on the average, were more than twice the amounts considered compatible with permanent agriculture. Scattered studies by others indicate that the findings are meaningful for a large area in the United States when row cropping is prevalent on sloping soils.

Pressures on cultivated land, in general, are mounting rapidly because of the rising demand for meat in industrialized nations and the soaring numbers of marginally fed people in Third World countries. The world population-food problem makes increasing stress on U.S. soils inevitable in the foreseeable future. Adequate protection against excessive loss of productive topsoil requires that the level of publicly supported soil conservation activities be promptly adjusted to this circumstance.
Raymond Lindeman and the Trophic-Dynamic Concept in Ecology
Authors: Cook Robert Edward
Published: October 2006

Lindeman's classic paper on energy flow in ecosystems was initially rejected for publication in
Ecology
. Reviewers felt there were insufficient data to support the theoretical model and that theoretical essays were inappropriate for
Ecology
. The paper was subsequently accepted by Thomas Park, the zoological editor, after correspondence with G. Evelyn Hutchinson who indicated the importance of theory in the development of ecology.
Gemmae: A Role in Sexual Reproduction in the Fern Genus
Vittaria
Authors: Emigh Virginia D. , Farrar Donald R.
Published: October 2006

Gemmae are generally defined as vegetative propagules. In the shoestring ferns,
Vittaria
, gemmae grown in the presence of mature gametophyte plants or on medium containing gibberellic acid produce antheridia in lieu of vegetative growth. This suggests that antheridial differentiation in
Vittaria
is controlled by a chemical antheridogen system similar to those described in other fern genera. In natural populations of
Vittaria
gametophytes composed primarily of long-lived individuals, gemmae may provide the only source of tissue susceptible to antheridogen action and may have evolved in response to that condition.
The Effect of the Floor Plate on Pattern and Polarity in the Developing Central Nervous System
Authors: Hirano Shigeki , Fuse Shigeaki , Sohal G. S.
Published: October 2006

The effect of floor plate on cellular differentiation in the neural tube of quail embryos was examined. In the developing neural tube the floor plate, which consists of specialized neuroepithelial cells, is located in the ventral midline of the neural tube. When Hensen's node was extirpated the floor plate and notochord did not develop, and the normal differentiation of the ventral horn motor neurons and dorsal and ventral roots did not occur. When one side of the neural tube was deprived of notochord, the ventro-dorsal differentiation took place on both sides. However, when one side of the neural tube was deprived of the floor plate, the ventral horn motor neurons and dorsal and ventral roots did not develop on that side. These observations suggest that the floor plate influences motor neuron differentiation and acts as an intrinsic organizer to establish pattern and polarity in the developing nervous system.
Alkaloids in Whole Plant Material: Direct Analysis by Kinetic Energy Spectrometry
Authors: Kondrat R. W. , Cooks R. G. , McLaughlin J. L.
Published: October 2006

A new approach to mixture analysis has been applied to the direct detection of various alkaloids in plant materials. The method requires absolutely no sample treatment. Results are presented for cocaine, morphine, papaverine, coniine, and atropine. The signal-to-background characteristics are superior to those of conventional mass spectrometry. Sensitivity is sufficient to detect and identify between 1 and 10 nanograms of alkaloid.
Sex Ratio: Adaptive Response to Population Fluctuations in Pandalid Shrimp
Authors: Charnov Eric L. , Gotshall Daniel W. , Robinson Jack G.
Published: October 2006

Pandalus jordani
is a protandrous (sequential) hermaphrodite. Populations show large year-to-year variation in age composition. In response to this variation, individuals alter the age at which they change sex. This response is predicted by a genetic model that assumes that an individual shrimp maximizes its genetic contribution to the next generation.
Pollination by Lemurs and Marsupials: An Archaic Coevolutionary System
Authors: Sussman Robert W. , Raven Peter H.
Published: October 2006

Existing geographical and ecological relationships between bats, nonflying mammals, and birds that visit flowers for food suggest novel interpretations of their evolutionary history.
Recovery and Maintenance of Live Amphipods at a Pressure of 580 Bars from an Ocean Depth of 5700 Meters
Authors: Yayanos A. Aristides
Published: October 2006

Amphipods were collected from an ocean depth of 5700 meters in a windowed pressure-retaining trap, kept alive in the trap for as long as 9 days aboard ship, and transported to a land laboratory. Observations suggest that the animals can easily tolerate decompressions of 29 percent and briefly of 70 percent of the value of 580 bars, the pressure of their natural habitat. The average pleopod beat frequency was 106 beats per minute. Evidence suggests that food (fish bait) can have at least a 4-day residence time in the gut of these animals.
Periodic Freshwater Flooding and Stagnation of the Eastern Mediterranean Sea During the Late Quaternary
Authors: Williams Douglas F. , Thunell Robert C. , Kennett James P.
Published: October 2006

Major negative oxygen isotopic anomalies in planktonic foraminifera are associated with deep-sea anoxic mud layers (sapropels) deposited 9000 and 80,000 years ago in the eastern Mediterranean. The isotopic depletion in surface-dwelling foraminifera is significantly greater than in mesopelagic foraminifera. This difference in isotopic response suggests that surface-water salinities were drastically reduced during times of sapropel formation, possibly as the result of meltwater runoff from the Fennoscandian ice sheet into the eastern Mediterranean by way of the Black and Aegean seas.
Airplane Accident Fatalities Increase Just After Newspaper Stories About Murder and Suicide
Authors: Phillips David P.
Published: October 2006

Fatal crashes of private, business, and corporate-executive airplanes have increased after publicized murder-suicides. The more publicity given to a murder-suicide, the more crashes occurred. The increase in plane crashes occurred primarily in states where the murder-suicides were publicized. These findings suggest that murder-suicide stories trigger subsequent murder-suicides, some of which are disguised as airplane accidents.
Isoleucine Epimerization in Peptides and Proteins: Kinetic Factors and Application to Fossil Proteins
Authors: Kriausakul Nivat , Mitterer Richard M.
Published: October 2006

The observed rate of isoleucine epimerization in peptides and proteins is dependent on (in addition to time and temperature) (i) the position of isoleucine in the peptide chain, (ii) the nature of adjacent amino acids, and (iii) the stability of the isoleucine peptide bonds. The relative rate is: NH
2
-terminal > COOH-terminal ⪢ interior ≥ free amino acid. The gradual hydrolysis of peptides and proteins to the more slowly epimerizing free amino acid causes a decrease in the apparent first-order rate constant with time. These results explain the isoleucine kinetics observed in fossil shells.
Metastable Oxygen Emission Bands
Authors: Slanger Tom G.
Published: October 2006

Recombination of ground-state oxygen atoms populates six different bound electronic states of molecular oxygen. Of the six optical transitions expected between the three upper states at 4 to 4.5 electron volts and the two lowest states, five have been observed in the afterglow of a conventional helium-oxygen microwave discharge in both
16
O
2
and
18
O
2
, three of them for the first time in gas-phase spectra. Generation of these emissions from oxygen atoms in a system free of molecular oxygen establishes that atom recombination is the production mechanism.
A New Cofactor in a Prokaryotic Enzyme: Tryptophan Tryptophylquinone as the Redox Prosthetic Group in Methylamine Dehydrogenase
Authors: McIntire William S. , Wemmer David E. , Chistoserdov Andrei , Lidstrom Mary E.
Published: October 2006

Methylamine dehydrogenase (MADH), an α
2
β
2
enzyme from numerous methylotrophic soil bacteria, contains a novel quinonoid redox prosthetic group that is covalently bound to its small β subunit through two amino acyl residues. A comparison of the amino acid sequence deduced from the gene sequence of the small subunit for the enzyme from
Methylobacterium extorquens
AM1 with the published amino acid sequence obtained by the Edman degradation method, allowed the identification of the amino acyl constituents of the cofactor as two tryptophyl residues. This information was crucial for interpreting
1
Hand
13
C nuclear magnetic resonance, and mass spectral data collected for the semicarbazide- and carboxymethyl-derivatized bis(tripeptidyl)-cofactor of MADH from bacterium W3A1. The cofactor is composed of two cross-linked tryptophyl residues. Although there are many possible isomers, only one is consistent with all the data: The first tryptophyl residue in the peptide sequence exists as an indole-6,7-dione, and is attached at its 4 position to the 2 position of the second, otherwise unmodified, indole side group. Contrary to earlier reports, the cofactor of MADH is not 2,7,9-tricarboxypyrroloquinoline quinone (PQQ), a derivative thereof, or pro-PQQ. This appears to be the only example of two cross-linked, modified amino acyl residues having a functional role in the active site of an enzyme, in the absence of other cofactors or metal ions.
Some Applications of Fluorimetry to Synthetic Polymer Studies
Authors: Morawetz Herbert
Published: October 2006

Fluorimetry, a powerful research tool in the study of biological macromolecules, has a number of valuable applications in investigations of synthetic polymers. These techniques reveal the microscopically heterogeneous distribution of species in polymer systems, which is specially pronounced in solutions of polyelectrolytes. They also allow us to study conformational mobility of flexible chains, diffusion-controlled intermolecular reactions of macromolecular reagents, glass transition phenomena, and polymer compatibility.
Microevolution and Clone Structure in
Spartina patens
Authors: Silander John A.
Published: October 2006

Analysis of the clone structures within a population of
Spartina patens
reveals considerable adaptive genetic divergence among adjacent dune, swale, and marsh sites. The dune subpopulation includes a small number of frequently encountered, spatially isolated clones that follow microtopography and have high reproductive output and colonizing potential. The marsh subpopulation consists of a large number of infrequent interdigitating clones with high vegetative biomass and competitive success. The swale subpopulation is generally intermediate for these traits.
Nitrogenous Nutrition of Marine Phytoplankton in Nutrient-Depleted Waters
Authors: McCarthy James J. , Goldman Joel C.
Published: October 2006

Variability in the small-scale temporal and spatial patterns in nitrogenous nutrient supply, coupled with an enhanced uptake capability for nitrogenous nutrients induced by nitrogen limitation, make it possible for phytoplankton to maintain nearly maximum rates of growth at media nutrient concentrations that cannot be quantified with existing analytical techniques.
Ionosphere of Venus: First Observations of Day-Night Variations of the Ion Composition
Authors: Taylor Harry A. , Brinton Henry C. , Bauer Siegfried J. , Hartle Richard E. , Cloutier Paul A. , Daniell Robert E. , Donahue Thomas M.
Published: October 2006

The Bennett radio-frequency ion mass spectrometer on the Pioneer Venus orbiter is returning the first direct composition evidence of the processes responsible for the formation and maintenance of the nightside ionosphere. Early results from predusk through the nightside in the solar zenith angle range 63° (dusk) to 120° (dawn) reveal that, as on the dayside, the lower nightside ionosphere consists of F
1
and F
2
layers dominated by O
2
+
and O
+
, respectively. Also like the dayside, the nightside composition includes distributions of NO
+
, C
+
, N
+
, H
+
, He
+
, CO
2
+
, and 28
+
(a combination of CO
+
and N
2
+
). The surprising abundance of the nightside ionosphere appears to be maintained by the transport of O
+
from the dayside, leading also to the formation of O
2
+
through charge exchange with CO
2
. Above the exobase, the upper nightside ionosphere exhibits dramatic variability in apparent response to variations in the solar wind and interplanetary magnetic field, with the ionopause extending to several thousand kilometers on one orbit, followed by the complete removal of thermal ions to altitudes below 200 kilometers on the succeeding orbit, 24 hours later. In the upper ionosphere, considerable structure is evident in many of the nightside ion profiles. Also evident are horizontal ion drifts with velocities up to the order of 1 kilometer per second. Whereas the duskside ionopause is dominated by O
+
H
+
dominates the topside on the dawnside of the antisolar point, indicating two separate regions for ion depletion in the magnetic tail regions.
Highly Reiterated Sequences of SIMIANSIMIANSIMIANSIMIANSIMIAN
Authors: Rosenberg Hagai , Singer Maxine , Rosenberg Martin
Published: October 2006

A 172-base pair segment of DNA that is repeated several million times in the genome of the African green monkey has been characterized. Sequence analysis revealed that the many repeats of this complex unit are not all identical but represent a set of closely related segments: Sequence divergence occurs at various positions in the segment in a nonrandom manner. The uncloned segment obtained from monkey DNA is compared with a cloned segment of the same DNA which was recombined into the genome of simian virus 40 during permissive infection.
Ganymede: Radar Surface Characteristics
Authors: Goldstein R. M. , Green R. R.
Published: October 2006

Radar observations of Ganymede, at X-band, show that the surface is unusually bright and has unusual polarization properties. A model of the surface based on large numbers of random ice facets (hence vacuum-ice interfaces) is able to account for these characteristics.
Nitric Oxide in Seawater
Authors: Zafiriou O. C. , McFarland M. , Bromund R. H.
Published: October 2006

Nitrite photolysis at natural light intensities and normal nitrite concentrations in seawater produced detectable concentrations of nitric oxide, which was consumed rapidly by a dark chemical reaction in the laboratory. Nitric oxide was also detected in situ in nitrite-rich surface waters of the central equatorial Pacific, where it formed in daylight and disappeared rapidly at sunset. The formation and rapid cycling of nitric oxide implies the presence of other free radicals in seawater, perhaps as intermediates in ongoing autoxidation processes. The central equatorial Pacific is a nitric oxide source to the atmosphere.
Magnetic Bubble Materials
Authors: Giess Edward A.
Published: October 2006

Physicists, materials scientists, and engineers combined to bring solid-state bubble devices into the computer memory and recording marketplace. Devices with smaller bubbles are being developed for increased data capacity and lower cost. Epitaxial garnet films made by isothermal dipping in molten solutions helped put the technology in place and will probably satisfy the material needs of future devices with bubbles scaled down from 2 to 0.5 micrometer in size.
Interaction Between Posture, Color, and the Radiative Heat Load in Birds
Authors: Lustick Sheldon , Adam Margaret , Hinko Alexander
Published: October 2006

The effect of the angle of incidence on the radiative heat load was determined for light and dark plumage. As the angle of incidence to the solar radiation source increases the difference in heat transfer between light and dark plumage disappears. Thus, by postural adjustment, a dark bird may become thermally white with regard to the radiative heat load.
Chemical Feeding Deterrent Mobilized in Response to Insect Herbivory and Counteradaptation by
Epilachna tredecimnotata
Authors: Carroll C. Ronald , Hoffman Carol A.
Published: October 2006

Experimentally damaged leaves of
Cucurbita moschata
mobilize substances to the damaged region within 40 minutes. These substances stimulate feeding by
Acalymma vittata
(Coleoptera: Chrysomelidae) and inhibit feeding by
Epilacha tredecimnotata
(Coleoptera: Coccinelidae). Under natural conditions,
Epilachna
cuts a circular trench in the leaf before feeding on the encircled leaf material, thus preventing mobilization of the deterrent substances to the feeding area.
Origin and Mechanism of Large-Scale Climatic Oscillations
Authors: Sergin V. Ya.
Published: October 2006

Numerical experiments with a simplified thermodynamic model of the glacier-ocean-atmosphere global system have been performed. Characteristic regimes of the system are auto-oscillations with periods varying between 20,000 and 80,000 years. The longer climatic waves are generated by the influence of variations of the earth's orbital parameters. Computed changes of glacial area, temperature, sea level, and other climate characteristics have values within expected ranges. The transition from a relatively warm epoch (when continental ice sheets are absent) to conditions characteristic of the Pleistocene is modeled. The calculated curves show how weak temperature fluctuations have been followed by large-scale oscillations.
Nutmeg Dispersal by Tropical Birds
Authors: Howe Henry F. , Vande Kerckhove Gayle A.
Published: October 2006

Frugivorous birds preferentially remove fruits from Panamanian
Virola
trees where the ratio of edible aril to indigestible seed is high. A negative correlation between the proportion of the crop removed and mean seed size explains 59 percent of the variance in removal, suggesting that birds minimize ingestion of useless bulk.
Total Eclipses of the Sun
Authors: Zirker J. B.
Published: October 2006

Total eclipses of the sun offer research opportunities in a variety of sciences. Some of the advances in solar physics resulting from eclipse observations are discussed. Experiments at the total eclipse of 16 February 1980 in India are also described. These included a test of general relativity, studies in coronal physics, investigations of solar prominences, diameter measurements, a search for interplanetary dust, a study of the gravity waves in the earth's atmosphere, and experiments on the biological effects on animals and humans.
Opiate Effects After Adrenocorticotropin or β-Endorphin Injection in the Periaqueductal Gray Matter of Rats
Authors: Jacquet Yasuko F.
Published: October 2006

Injections of adrenocorticotropic hormone (ACTH) into the periaqueductal gray matter of drug-naive rats resulted in a dose-dependent opiate abstinence syndrome characterized by fearful hyperreactivity and explosive motor behavior. Injecting shorter chains of ACTH caused attenuated forms of this behavior. Injections of β-endorphin at this same site caused opposite behavior: sedative, analgesic, and catatonic. If the effects of morphine are mediated by two classes of receptor) and the other which is not stereospecific and naloxone-insensitive—the endogtor)—and the other which is not stereospecific and naloxone-insensitive the endogenous ligand of the second receptor may be ACTH. The neuropeptides ACTH and endorphin may be part of an integrated neuromodulatory system, and the opiate abstinence syndrome may be the result of an altered interaction between the two receptor systems.
Theoretical Organometallic Chemistry
Authors: Hoffmann Roald
Published: October 2006

Organometallic chemists have synthesized a remarkable variety of new structural types. In these structures ligands, which are organic or inorganic molecules of variable independent stability, bind to one or more transition metal atoms. An approach to an understanding of the electronic structure, geometrical preferences, and reactivity of these complexes may be made if the molecule is "decomposed" conceptually into a metal fragment, ML
η
, and a ligand. A library of the molecular orbitals of these fragments is becoming available. One then "reconstructs" the molecule by examining the interaction of the orbitals of the ligand, typically an organic molecule, with the orbitals of the ML
η
fragment.
Purine Resistant Mutants of
Drosophila
Are Adenine Phosphoribosyltransferase Deficient
Authors: Johnson Daniel H. , Friedman Thomas B.
Published: October 2006

A deficiency for adenine phosphoribosyltransferase activity is the primary biochemical defect in mutants of
Drosophila
selected for resistance to purine-induced lethality.
Chemicals from Biomass: Petrochemical Substitution Options
Authors: Lipinsky E. S.
Published: October 2006

As a source of chemicals, biomass has several intrinsic advantages over fossil mass: it is renewable, flexible through crop switching, and adaptable through genetic manipulation. Inflexibility of the fossil mass resource is compensated for by highly effective technology for production of olefins and aromatics, economies of scale, and a highly developed system of conversion products with large markets. Direct and indirect strategies to substitute for petrochemicals are based on ecological succession concepts. A proliferation of lignocellulosic fractionation processes is arising from the need for inexpensive, homogeneous, chemically useful biomass feedstocks.
Central Object of the 30 Doradus Nebula, a Supermassive Star
Authors: Cassinelli Joseph P. , Mathis John S. , Savage Blair D.
Published: October 2006

R136 (HD 38268) is the central object of the 30 Doradus Nebula, a giant region of ionized hydrogen in the Large Magellanic Cloud. Observations of R136 at low and high spectral resolution with the International Ultraviolet Explorer reveal a peculiar hot object with a massive stellar wind. An outflow speed of 3500 kilometers per second and a temperature of approximately 60,000 K are indicated by the spectra. The bulk of the observed ultraviolet radiation must come from R136a, the brightest and bluest component of R136. Its absolute visual magnitude and observed temperature imply a luminosity about 10
8
times that of the sun. Most of the ionizations produced in 30 Doradus are provided by this peculiar object. If RI36a is a dense cluster of very hot stars, about 30 stars of classes O3 and WN3 exist in a region estimated to have a diameter of less than 0.1 parsec. This is inconsistent with the ultraviolet line spectrum and the evidence for optical variability. An alternative interpretation of the observations is that the radiation from R136a is dominated by a single superluminous object with the following approximate properties: luminosity and temperature as given above, a radius 100 times that of the sun, a mass 2500 times that of the sun, and a loss rate of 10
–3.5
solar masses per year. Model interior calculations for hydrogen-burning stars are consistent with these parameters. Such stars, however, are expected to be unstable, and this may account for the massive stellar wind.
Antibiotic-Induced Inhibition of Pheromone Synthesis in a Bark Beetle
Authors: Byers J. A. , Wood D. L.
Published: October 2006

Ingestion of diet containing streptomycin inhibited the conversion of myrcene, a host plant terpene, to the male-specific pheromones ipsenol and ipsdienol in
Ips paraconfusus
. Synthesis of
cis
-verbenol, which is not a sex-specific pheromone, from the host plant terpene (–)-α -pinene and other metabolites from these two terpenes was not inhibited by the antibiotic.
T Cell Antigen Receptor-Mediated Activation of Phospholipase C Requires Tyrosine Phosphorylation
Authors: Mustelin T. , Coggeshall K. M. , Isakov N. , Altman A.
Published: October 2006

Triggering of the antigen-specific T cell receptor-CD3 complex (TCR-CD3) stimulates a rapid phospholipase C-mediated hydrolysis of inositol phospholipids, resulting in the production of second messengers and in T cell activation and proliferation. The role of tyrosine phosphorylation in these events was investigated with a tyrosine protein kinase (TPK) inhibitor, genistein. At doses that inhibited TPK activity and tyrosine phosphorylation of the TCR ζ subunit, but not phospholipase C activity, genistein prevented TCR-CD3-mediated phospholipase C activation, interleukin-2 receptor expression, and T cell proliferation. These findings indicate that tyrosine phosphorylation is an early and critical event that most likely precedes, and is a prerequisite for, inositol phospholipid breakdown during receptor-mediated T cell activation.
Holocene Vegetation in Chaco Canyon, New Mexico
Authors: Betancourt Julio L. , Van Devender Thomas R.
Published: October 2006

Well-preserved plant remains in packrat middens chronicle vegetation change in Chaco Canyon over the past 11,000 years. Early Holocene evidence of communities dominated by Douglas fir, Rocky Mountain juniper, and limber pine in the San Juan Basin calls for revision of traditional constructs based on fossil pollen. Middle and late Holocene vegetation in the canyon was pinyon-juniper woodland up until Anasazi occupation between 1000 and 800 years ago. Instead of climate, Anasazi fuel needs may explain the drastic reduction of pinyon and juniper after 1230 years ago. The lack of pinyon-juniper recovery over the past millennium has implications for contemporary forest and range ecology.
Extreme Ultraviolet Observations from the Voyager 2 Encounter with Saturn
Authors: Sandel B. R. , Shemansky D. E. , Broadfoot A. L. , Holberg J. B. , Smith G. R. , McConnell J. C. , Strobel D. F. , Atreya S. K. , Donahue T. M. , Moos H. W. , Hunten D. M. , Pomphrey R. B. , Linick S.
Published: October 2006

Combined analysis of helium (584 angstroms) airglow and the atmospheric occultations of the star δ Scorpii imply a vertical mixing parameter in Saturn's upper atmosphere of K (eddy diffusion coefficient) ∼8 × 10
7
square centimeters per second, an order of magnitude more vigorous than mixing in Jupiter's upper atmosphere. Atmospheric H
2
band absorption of starlight yields a preliminary temperature of 400 K in the exosphere and a temperature near the homopause of ∼200 K. The energy source for the mid-latitude H
2
band emission still remains a puzzle. Certain auroral emissions can be fully explained in terms of electron impact on H
2
, and auroral morphology suggests a link between the aurora and the Saturn kilometric radiation. Absolute optical depths have been determined for the entire C ring and parts of the A and B rings. A new eccentric ringlet has been detected in the C ring. The extreme ultraviolet reflectance of the rings is fairly uniform at 3.5 to 5 percent. Collisions may control the distribution of H in Titan's H torus, which has a total vertical extent of ∼14 Saturn radii normal to the orbit plane.
Precambrian Age of the Boston Basin: New Evidence from Microfossils
Authors: Lenk Cecilia , Strother Paul K. , Kaye Clifford A. , Barghoorn Elso S.
Published: October 2006

A Vendian (Late Proterozoic Z) age has been determined for the Boston Basin by comparison of a microflora from the Cambridge Argillite with other late Precambrian assemblages. The microfossils, which include
Bavlinella
cf.
faveolata
, are preserved as petrifactions in pyrite. This age designation for the sedimentary rocks of the Boston Basin should allow for the reinterpretation of the structure of the basin and its regional correlations.
Intracerebral Adrenocorticotropic Hormone Mediates Novelty-Induced Grooming in the Rat
Authors: Dunn Adrian J. , Green Edward J. , Isaacson Robert L.
Published: October 2006

Intact male rats exhibited more grooming in unfamiliar testing chambers than in their home cages. Hypophysectomized rats showed a much reduced increase in grooming in these testing chambers. Intraventricular injections of antiserum to adrenocorticotropic hormone to intact rats decreased the grooming usually observed in the novel situation, whereas a similar injection of control serum did not produce this effect. Peripheral injections of the antiserum did not affect grooming. Since intraventricularly injected adrenocorticotropic hormone induces excessive grooming, these results suggest that the increased grooming observed in the novel environment may be at least partly due to the release of this hormone directly into the cerebral ventricular system.
L-Canavanine, a Dietary Nitrogen Source for the Seed Predator
Caryedes brasiliensis
(Bruchidae)
Authors: Rosenthal Gerald A. , Hughes Charlie G. , Janzen Daniel H.
Published: October 2006

Larvae of the bruchid beetle
Caryedes brasiliensis
(Bruchidae) develop entirely within the seed of the neotropical legume
Dioclea megacarpa
The seed contains an appreciable concentration of L-canavanine, a potent antimetabolite and structural analog of L-arginine. This bruchid beetle uses the nitrogen stored in this toxic allelochemical as an effective dietary nitrogen source for amino acid biosynthesis.
Banded Corals: Changes in Oceanic Carbon-14 During the Little Ice Age
Authors: Druffel Ellen M.
Published: October 2006

Radiocarbon analyses and stable isotope measurements are presented for two recent cores of banded corals from the Florida Straits. These values provide a record of variations in the ratio of carbon-14 to carbon-12 in the dissolved inorganic carbon in the surface waters of the Gulf Stream from A.D. 1642 to 1800. An increase in the carbon-14/carbon-12 ratio of 7 per mil for coral growth during the early 1700's was most likely induced by an increase in the carbon-14/carbon-12 ratio of 20 per mil in the atmospheric carbon dioxide that occurred at about 1700. The ratios of oxygen-18 to oxygen-16 in these coral bands show a small decrease of water temperature (∼1°C) during the latter part of the Little Ice Age (1700 to 1725). These results support the hypothesis that the increase in atmospheric carbon-14 at about 1700, and possibly the temperature change as well, was caused by a decrease in solar activity (Maunder sunspot minimum).
Hydration Aging of Nuclear Waste Glass
Authors: Bates J. K. , Jardine L. J. , Steindler M. J.
Published: October 2006

The aging of simulated nuclear waste glass by contact with a controlled-temperature, humid atmosphere results in the formation of a double hydration layer penetrating into the glass and in the formation of minerals on the glass surface. The hydration process described here provides insight into the aging kinetics of naturally occurring glasses and also suggests that simulated aging reactions are necessary for demonstrating that nuclear waste forms can meet projected Nuclear Regulatory Commission requirements.
Fast Atom Bombardment Mass Spectrometry
Authors: Rinehart Kenneth L.
Published: October 2006

Fast atom bombardment mass spectrometry has become a powerful structural tool since the first reports of its use in 1981. Samples are ionized in the condensed state, usually in a glycerol matrix, by bombarding the matrix with xenon or argon atoms with energies of 5000 to 10,000 electron volts. This yields both positive and negative secondary ions, which are sputtered from the surface. The technique has been used to detect inorganic ion clusters to mass 25,800 and biologically active peptides to mass 5700, and it gives molecular ions of such highly polar or labile organic compounds as glycosphingolipids and polyene antibiotics. It can be especially valuable in determining the sequences of amino acids in polypeptides.
Chemistry and World Food Supplies
Authors: Brady Nyle C.
Published: October 2006

Much of the unprecedented increase in developing countries' food production in the past two decades is due to chemical-based technologies and to the use of agricultural chemicals. However, these successes were won under generally favorable conditions of soil, climate, and irrigation water availability. The challenge of the future is to broaden the base of increased food production to include areas less well endowed with natural and economic resources. Chemistry and chemicals must play vital roles in this venture. Innovative chemical and biochemical approaches must be called upon to produce crop varieties, animal strains, and associated technologies to overcome constraints such as insects and diseases, acid and alkaline soils, and drought conditions. Genetic engineering will probably be a primary mechanism to achieve this goal.
Demography of Northern Elephant Seals, 1911-1982
Authors: Cooper Charles F. , Stewart Brent S.
Published: October 2006

Northern elephant seals (
Mirounga angustirostris
) were hunted to near extinction in the 19th century. Protection has allowed them to recolonize former habitat on islands off California, where the population is increasing more than 14 percent per year. Immigration of young pregnant females from Baja California initiated the California rookeries but is responsible for only a small part of recent population growth. Almost 25,000 northern elephant seal pups were born in the species' range in Mexico and the United States in 1982 in comparison with only six known births in 1911.
Defense in Thrips: Forbidding Fruitiness of a Lactone
Authors: Howard Dennis F. , Blum Murray S. , Fales Henry M.
Published: October 2006

Expulsion of anal fluid from the upturned abdomen was demonstrated to serve a defensive function in the thrips
Bagnalliella yuccae
. An allomone in the anal exudate was identified as γ-decalactone, a fruity-smelling compound that repelled potential predators. Chemical defenses may contribute to the ability of thrips to maintain large aggregations.
Thermodiffusional Transport in Pelagic Clay: Implications for Nuclear Waste Disposal in Geological Media
Authors: Thornton E. C. , Seyfried W. E.
Published: October 2006

Thermal gradient experiments in sediment-seawater systems revealed large-scale fluxes of aqueous electrolytic components away from the heat source through thermal diffusion. These findings indicate a need for similar studies in other geological materials of low permeability in order to assess the implications of this phenomenon for various nuclear waste disposal options.
Antibody-Mediated Activation of
Drosophila
Heat Shock Factor in Vitro
Authors: Zimarino Vincenzo , Wilson Susan , Wu Carl
Published: October 2006

Eukaryotic cells respond to elevated temperatures by rapidly activating the expression of heat shock genes. Central to this activation is heat shock-inducible binding of the transcriptional activator, termed heat shock factor (HSF), to common regulatory elements, which are located upstream of all heat shock genes. The DNA binding activity of the inactive form of
Drosophila
HSF was induced in vitro by treatment with polyclonal antibodies to the purified, in vivo-activated factor. This finding, together with observations that high temperature and low pH activate HSF binding in vitro, suggests that the inactive form of HSF can directly recognize and transduce the heat shock signal without undergoing a covalent modification of protein structure.
Anthropogenic Chlorofluoromethanes in the Greenland and Norwegian Seas
Authors: Bullister J. L. , Weiss R. F.
Published: October 2006

The concentrations of two industrially produced chlorofluoromethanes, CCl
3
F(F-11) and CCl
2
F
2
(F-12), have been measured in the water column and in the marine atmosphere of the Greenland and Norwegian seas. Measurable concentrations of these two chlorofluoromethanes have penetrated to the deep basins of both of these regions, and the general characteristics of their vertical distributions are similar to those of the bomb-produced radioisotopes injected into the atmosphere on a similar time scale. The data have been fitted to a time-dependent box model based on deep convective mixing in the Greenland Sea and lateral exchange between the deep basins. The model calculations for the two chlorofluoromethanes in the Greenland Sea give similar results, with a time scale for deep convection of about 40 years. The time scale for lateral mixing between the deep Greenland Sea and the deep Norwegian Sea is estimated to be 20 to 30 years, although the agreement between the calculations for the two chlorofluoromethanes is limited by analytical uncertainties at the low concentrations found in the deep Norwegian Sea and by uncertainties in the model assumptions.
Is There Any Chlorine Monoxide in the Stratosphere?
Authors: Mumma M. J. , Rogers J. D. , Kostiuk T. , Deming D. , Hillman J. J. , Zipoy D.
Published: October 2006

A ground-based search for stratospheric chlorine monoxide was carried out during May and October 1981 with an infrared heterodyne spectrometer in the solar absorption mode. Lines due to stratospheric nitric acid and tropospheric carbonyl sulfide were detected at about 0.2 percent absorptance levels, but the expected 0.1 percent lines of chlorine monoxide in this same region were not seen. Stratospheric chlorine monoxide is less abundant by at least a factor of 7 than is indicated by in situ measurements, and the upper limit for the integrated vertical column density of chlorine monoxide is 2.3 × 10
13
molecules per square centimeter at the 95 percent confidence level. These results imply that the release of chlorofluorocarbons may be significantly less important for the destruction of stratospheric ozone than is currently thought.
Sex Change in a Coral-Reef Fish: Dependence of Stimulation and Inhibition on Relative Size
Authors: Ross Robert M. , Losey George S. , Diamond Milton
Published: October 2006

The removal of a single dominant individual has been shown to trigger a sex change in some coral-reef fish. In the saddleback Wrasse (
Thalassoma duperrey
), however, female-to-male sex change requires visual stimulation from smaller conspecifics. This change is not dependent on the sex or color of the stimulus fish and can be inhibited by larger conspecifics. On the reef, a female probably changes sex when the relative numbers of larger and smaller conspecifics change within her home range.
Radiation Hybrid Mapping: A Somatic Cell Genetic Method for Constructing High-Resolution Maps of Mammalian Chromosomes
Authors: Cox David R. , Burmeister Margit , Price E. Roydon , Kim Suwon , Myers Richard M.
Published: October 2006

Radiation hybrid (RH) mapping, a somatic cell genetic technique, was developed as a general approach for constructing long-range maps of mammalian chromosomes. This statistical method depends on x-ray breakage of chromosomes to determine the distances between DNA markers, as well as their order on the chromosome. In addition, the method allows the relative likelihoods of alternative marker orders to be determined. The RH procedure was used to map 14 DNA probes from a region of human chromosome 21 spanning 20 megabase pairs. The map was confirmed by pulsed-field gel electrophoretic analysis. The results demonstrate the effectiveness of RH mapping for constructing high-resolution, contiguous maps of mammalian chromosomes.
Biotechnology in the Marine Sciences
Authors: Colwell Rita R.
Published: October 2006

Genetic engineering applied to the production of fish, molluscs, algae, algal products, and crustaceans in natural environments and hatchery systems is still at the rudimentary stage. Cloning systems for producing commercially important chemicals, pharmacologically active compounds, and metamorphosis-stimulating substances present in marine organisms are being sought. Attempts are being made to develop useful drugs from the sea, including antineoplastic, antibiotic, growth-promoting (or -inhibiting), analgesic, and antispasmodic agents. Immediate commercial applications can be expected from engineered systems involving polysaccharide and specialty chemical production, with marine microorganisms as the source of genetic material.
Host-Selective Toxins and Their Role in Plant Diseases
Authors: Scheffer Robert P. , Livingston Robert S.
Published: October 2006

Toxins with unusual characteristics are involved in some destructive diseases of plants. Certain parasitic fungi produce toxins of low molecular weight that selectively affect the host plant; nonhosts are tolerant. These toxins have diverse structures, including cyclic peptides and linear polyketols. Genetic and other data show that resistance to each fungus is based on tolerance to its toxin. The same fungal genes control toxin production and ability to cause disease. Little is known about toxic action, although one toxin selectively affects mitochondria. Plant cell membranes are affected; this may allow the fungus to colonize tissues. Resistant cells may lack toxin receptor sites.
The Meteorite-Asteroid Connection: Two Olivine-Rich Asteroids
Authors: Cruikshank Dale P. , Hartmann William K.
Published: October 2006

Two asteroids have clear indications of olivine-rich surface petrology without any indication of pyroxene or plagioclase, suggesting that the olivine may be quite pure. They provide probable examples of mantles of differentiated parent asteroids exposed by fragmentation and are good candidates for the parent bodies of the unusual olivine meteorite Brachina or the olivine-iron alloy meteorites called pallasites.
An El Niño Signal in Atmospheric Angular Momentum and Earth Rotation
Authors: Rosen Richard D. , Salstein David A. , Eubanks T. Marshall , Dickey Jean O. , Steppe J. Alan
Published: October 2006

Anomalously high values of atmospheric angular momentum and length of day were observed in late January 1983. This signal in the time series of these two coupled quantities appears to have been a consequence of the equatorial Pacific Ocean warming event of 1982-1983.
Divalent Carbon Intermediates: Laser Photolysis and Spectroscopy
Authors: Eisenthal Kenneth B. , Moss Robert A. , Turro Nicholas J.
Published: October 2006

A brief review is given of the structures of an important class of reactive intermediates, divalent carbon species (carbenes). The electronic properties of carbenes force an unusual electronic character upon these species that, in turn, leads to intriguing physical and chemical properties. Because of the fleeting nature of carbenes, which are extraordinarily reactive, direct investigation of their structural and chemical behavior has presented a challenge to the experimentalist. The application of spectroscopic and ultrafast laser techniques has met this challenge. With the use of laser methods, along with conventional techniques, quantitative evaluation of the energetics, dynamics, and reactivities of a variety of carbenes has been possible.