bluuebunny/crossref_metadata_2025 huggingface dataset:
Hydrogeologic Constraints on Yucatn's Development
Authors: Doehring Donald O. , Butler Joseph H.
Published: October 2006

The Republic of Mexico has an ambitious and effective national water program. The Secretaria de Recursos Hidraulicos (SRH), whose director has cabinet rank in the federal government, is one of the most professionally distinguished government agencies of its kind in the Americas. Resources for the Future, Inc., has been assisting the World Bank with a water planning study which the Bank is undertaking jointly with the Mexican government. The study is intended to provide guidelines for the development of government policies and projects designed to bring about the most efficient use of Mexico's water resources. However, to date, their study has not been directed toward the growing problems of the northern Yucatn Peninsula which are discussed here.

LeGrand suggested that man has inherited a harsh environment in carbonate terranes. In the case of the northern Yucatn Peninsula, the physical environment creates a set of hydrogeologic constraints to future economic and social development. Planning for intermediate and long-range land use on the peninsula must be related directly to the limited and fragile groundwater source. Continued contamination will make future aquifer management a difficult challenge for federal, state, and territorial agencies. We conclude that any strategy for long-range land use in the study area should include establishment of a regional aquifer-monitoring network for long-term measurements of key hydrogeologic parameters, including precipitation, evapotranspiration, water table elevations, and water quality. Information from this network would flow into a central facility for storage, interpretation, and analysis. At present the SRH is collecting some of these data. Expansion of the existing program to provide sound information for regional planning will greatly benefit present as well as future generations. If such a program is implemented, it will represent a model for regional planning in other tropical and subtropical karstic terrains.
Zinc Protoporphyrin in the Erythrocytes of Patients with Lead Intoxication and Iron Deficiency Anemia
Authors: Lamola A. A. , Yamane T.
Published: October 2006

The fluorescent porphyrin in the erythrocytes of patients with lead intoxication or with iron deficiency anemia is zinc protoporphyrin that is bound to globin moieties, probably at heme binding sites.
Continuous Random Network Model for Amorphous Solid Water
Authors: Alben Richard , Boutron Pierre
Published: October 2006

Continuous random network models representing amorphous solid water have been constructed. The x-ray and neutron scattering predictions for one type of model agree quite well with experimental results.
True Polar Wander since the Early Cretaceous
Authors: Jurdy D. M. , Van der Voo R.
Published: October 2006

The motions of the lithospheric plates have been reconstructed for three time intervals back to the Early Cretaceous. These displacements were analyzed to determine the best-fitting rigid rotation, which could then be ascribed to true polar wander. The true polar wander so obtained is no larger than a few degrees and is within the magnitude of the uncertainties involved.
Denudation Studies: Can We Assume Stream Steady State?
Authors: Trimble Stanley W.
Published: October 2006

Contemporary stream sediment loads are dubious indicators of regional denudation. Recent analysis of ten river basins in the southeastern United States indicates that of the material eroded from upland slopes since European settlement, only about 5 percent has been exported. The remainder, alluvium and colluvium, will probably not be exported because of extensive reservoir impoundments.
Ocean Thermal Gradient Hydraulic Power Plant
Authors: Beck Earl J.
Published: October 2006

Solar energy stored in the oceans may be used to generate power by exploiting thermal gradients. A proposed open-cycle system uses low-pressure steam to elevate water, which is then run through a hydraulic turbine to generate power. The device is analogous to an air lift pump.
Fossilized Eggs in a Pennsylvanian Blastoid
Authors: Katz Steven G. , Sprinkle James
Published: October 2006

A single specimen of
Pentremites rusticus
(Echinodermata, Blastoidea) from the Early Pennsylvanian of Oklahoma has hundreds of apparent eggs in one of its abnormal anal hydrospire groups. This rare occurrence suggests that female blastoids in this sexually dimorphic species had modified their anal hydrospiresfor brooding eggs instead of for normal respiration.
Endolithic Blue-Green Algae in the Dry Valleys: Primary Producers in the Antarctic Desert Ecosystem
Authors: Friedmann E. Imre , Ocampo Roseli
Published: October 2006

Endolithic unicellular blue-green algae occur under the surface of orthoquartzite rocks in the dry valleys of southern Victoria Land, Antarctica. This report of primary producers in the Antarctic desert ecosystem suggests that, in future efforts to detect life in extraterrestrial (for example, martian) environments, scientists should consider the possible existence of endolithic life forms.
Isotopic Composition of the Martian Atmosphere
Authors: Nier Alfred O. , McElroy Michael B. , Yung Yuk Ling
Published: October 2006

Results from the neutral mass spectrometer carried on the aeroshell of Viking 1 show evidence for NO in the upper atmosphere of Mars and indicate that the isotopic composition of carbon and oxygen is similar to that of Earth. Mars is enriched in
15
N relative to Earth by about 75 percent, a consequence of escape that implies an initial abundance of nitrogen equivalent to a partial pressure of at least 2 millibars. The initial abundance of oxygen present either as CO
2
or H
2
O must be equivalent to an exchangeable atmospheric pressure of at least 2 bars in order to inhibit escape-related enrichment of
18
O.
Calcium Carbonate Production, Coral Reef Growth, and Sea Level Change
Authors: Smith S. V. , Kinsey D. W.
Published: October 2006

Shallow, seaward portions of modern coral reefs produce about 4 kilograms of calcium carbonate per square meter per year, and protected areas produce about 0.8 kilogram per square meter per year. The difference is probably largely a function of water motion. The more rapid rate, equivalent to a maximum vertical accretion of 3 to 5 millimeters per year, places an upper limit on the potential of modern coral reef communities to create a significant vertical structure on a rising sea.
Structure of Mars' Atmosphere up to 100 Kilometers from the Entry Measurements of Viking 2
Authors: Seiff Alvin , Kirk Donn B.
Published: October 2006

The Viking 2 entry science data on the structure of Mars' atmosphere up to 100 kilometers define a morning atmosphere with an isothermal region near the surface; a surface pressure 10 percent greater than that recorded simultaneously at the Viking 1 site, which implies a landing site elevation lower by 2.7 kilometers than the reference ellipsoid; and a thermal structure to 100 kilometers at least qualitatively consistent with pre-Viking modeling of thermal tides. The temperature profile exhibits waves whose amplitude grows with altitude, to ∼25°K at 90 kilometers. These waves are believed to be a consequence of layered vertical oscillations and associated heating and cooling by compression and expansion, excited by the daily thermal cycling of the planet surface. As is necessary for gravity wave propagation, the atmosphere is stable against convection, except possibly in some very local regions. Temperature is everywhere appreciably above the carbon dioxide condensation boundary at both landing sites, precluding the occurrence of carbon dioxide hazes in northern summer at latitudes to at least 50°N. Thus, ground level mists seen in these latitudes would appear to be condensed water vapor.
Prevention of Apoptosis by a Baculovirus Gene During Infection of Insect Cells
Authors: Clem Rollie J. , Fechheimer Marcus , Miller Lois K.
Published: October 2006

Programmed cell death is an active process of self destruction that is important in both the development and maintenance of multicellular animals. The molecular mechanisms controlling activation or suppression of programmed cell death are largely unknown. Apoptosis, a morphologically and biochemically defined type of programmed cell death commonly seen in vertebrates, was found to be initiated during baculovirus replication in insect cells. A specific viral gene product, p35, was identified as being responsible for blocking the apoptotic response. Identification of the function of this gene will allow further definition of the molecular pathways involved in the regulation of programmed cell death and may identify the role of apoptosis in invertebrate viral defense systems.
Thyroid Hormone Action: The Mitochondrial Pathway
Authors: Sterling Kenneth , Milch Peter O. , Brenner Milton A. , Lazarus John H.
Published: October 2006

The subcellular compartments have been investigated to compare proteins capable of binding triiodothyronine and thyroxine; specific binders have been found in cytosol, nuclei, and mitochondria from rat liver and kidney. The binding protein from the inner mitochondrial membrane had the highest association constant (> 10
11
liters per mole), suggesting possible direct hormone action on the mitochondria. Binding of hormone analogs was found to be related to known physiological potency, and stereospecific discrimination between L- and D-thyroxine was observed. The saturable receptor was found in the mitochondrial membranes of rat liver, kidney, myocardium, and skeletal muscle but not in mitochondria from the unresponsive tissues: brain, spleen, and testis. Oxidative phosphorylation by mitochondrial vesicles from hypothyroid rats increased after the addition of physiological concentrations of triiodothyronine, which corroborated direct hormone action on mitochondria.
Glacial-Holocene Transition in Deep-Sea Carbonates: Selective Dissolution and the Stable Isotope Signal
Authors: Berger W. H. , Killingley J. S.
Published: October 2006

The oxygen and carbon isotopic signals of planktonic Foraminifera from closely spaced samples from two box cores taken in the western equatorial Pacific change through the glacial-to-Holocene transition as a result of several factors, one of which is the Holocene dissolution pulse starting about 12,000 years ago and reaching full force shortly after. The onset of dissolution comes shortly after the maximum rate of deglaciation but well before the maximum drop in fertility in upper waters. The effect of dissolution is 20 to 30 percent of the amplitude of isotopic change in
Globigerinoides sacculifer
, at the depth of the present lysocline.
Ozone Monitoring with an Infrared Heterodyne Radiometer
Authors: Menzies Robert T. , Seals Robert K.
Published: October 2006

Measurements of the total burden and of the concentration versus altitude profiles of ozone have been made with a ground-based heterodyne radiometer at Pasadena, California. The measurements were made in the 9.5-micrometer wavelength region, where a strong ozone infrared absorption band exists. The radiometer measured solar absorption at selected wavelengths, with a spectral resolution of 0.001 reciprocal centimeter, equivalent to the half-width of an ozone absorption line at the 10-millibar altitude level. A carbon dioxide laser served as the local oscillator. This technique can be used to gather important data on both tropospheric and stratospheric ozone, which are not readily accessible with other remote-sensing techniques.
Telecommunication with Neutrino Beams
Authors: Sáenz A. W. , Überall H. , Kelly F. J. , Padgett D. W. , Seeman N.
Published: October 2006

Collimated neutrino beams in the energy range 1 to 100 gigaelectron volts, now available from high-energy proton accelerators, are proposed as a potential means for telecommunication over global distances. Quantitative estimates of the feasibility of this proposal based on a particular detector configuration are presented.
Interstitial Nitrate Profiles and Oxidation of Sedimentary Organic Matter in the Eastern Equatorial Atlantic
Authors: Bender Michael L. , Fanning Kent A. , Froelich Philip N. , Heath G. Ross , Maynard Valentine
Published: October 2006

Pore-water nitrate concentrations in six pelagic eastern equatorial Atlantic cores increase from bottom water values (22 micromolar) to 40 micromolar at a depth of about 5 centimeters, then decrease to undetectable levels at depths as shallow as 40 centimeters. These nitrate concentrations and concentration gradients reflect zones of oxygen reduction, nitrate reduction, and sulfate reduction in the sediments. The estimated benthic flux of nitrate to the ocean from our data is much less than the total global flux of nitrate to deep waters, even though these equatorial sediments underlie a productive upwelling zone. The estimated denitrification rate in our study area suggests that pelagic sediments may be important sites of marine denitrification.
Strontium Uptake in Shell Aragonite from the Freshwater Gastropod
Limnaea stagnalis
Authors: Buchardt Bjørn , Fritz Peter
Published: October 2006

Shell aragonite from 96 specimens of the freshwater gastropod
Limnaea stagnalis
grown in laboratory tanks at different temperatures in water with variable strontium/calcium ratios have been analyzed for its strontium content in order to evaluate the mechanisms of strontium uptake in molluskan aragonite. Within the limits defined by natural freshwater environments, the strontium/calcium ratio in the aragonite was found to be linearly related to the strontium/calcium ratio in the water. A distribution coefficient k
A
Sr
= 0.237 ± 0.029, unaffected by variations in temperature and growth rate, has been found. This finding substantiates the existence of a strontium-discriminating effect in aragonite precipitated by mollusks as compared to the case for nonbiogenic aragonite which contains about five times as much strontium when precipitated under the same conditions.
Human Immunodeficiency Virus Infection of Human-PBL-SCID Mice
Authors: Mosier Donald E. , Gulizia Richard J. , Baird Stephen M. , Wilson Darcy B. , Spector Deborah H. , Spector Stephen A.
Published: October 2006

Severe combined immunodeficient (SCID) mice reconstituted with human peripheral blood leukocytes (hu-PBL-SCID mice) have inducible human immune function and may be useful as a small animal model for acquired immunodeficiency syndrome (AIDS) research. Hu-PBL-SCID mice infected with human immunodeficiency virus-1 (HIV-1) contained virus that was recoverable by culture from the peritoneal cavity, spleen, peripheral blood, and lymph nodes for up to 16 weeks after infection; viral sequences were also detected by in situ hybridization and by amplification with the polymerase chain reaction (PCR). Mice could be infected with multiple strains of HIV-1, including LAV-1/Bru, IIIB, MN, SF2, and SF13. HIV-1 infection affected the concentration of human immunoglobulin and the number of CD4
+
T cells in the mice. These results support the use of the hu-PBL-SCID mouse for studies of the pathogenesis and treatment of AIDS.
Disturbance and the Dispersal of Fleshy Fruits
Authors: Thompson John N. , Willson Mary F.
Published: October 2006

Fruits of
Prunus serotina
,
Phytolacca Americana
, and
Vitis vulpina
were placed during separate trials in forest sites that varied in the degree to which the forest canopy was disturbed. Removal rates of fruits were consistently faster in the forest edge and light gap sites than in sites under closed canopy. Rapid removal of fruits from species that ripen fruit in summer and early fall is selectively advantageous to the plants because it minimizes the probability that fruits will be destroyed by invertebrates before dispersal. Disturbances probably play an important role in interactions between temperate fruits and birds and in community organization.
Proteins in a Nonvenomous Defensive Secretion: Biosynthetic Significance
Authors: Aldrich J. R. , Blum M. S. , Hefetz A. , Fales H. M. , Lloyd H. A. , Roller P.
Published: October 2006

In common with many arthropods, the true bug,
Leptoglossus phyllopus
, when disturbed, emits a two-phase secretion that consists of an organic phase and an aqueous phase. The organic phase is a mixture of highly reactive low-molecular-weight compounds, analogous to those produced by other arthropods, and is deterrent to many kinds of predators. The aqueous phase, heretofore ignored in most analyses of arthropod defensive secretions, contains proteins. Even though the secretion is not injected, the proteins enzymatically catalyze the derivation of the most reactive components within the impermeable cuticular storage reservoir and, thus, constitute part of the defensive system that appears to be commonly used by arthropods producing irritating chemicals.
Tentaculites:
Evidence for a Brachiopod Affinity?
Authors: Towe Kenneth M.
Published: October 2006

Transmission electron microscope studies of fractured surfaces reveal that the shells of
Tentaculites
are constructed of calcite with a ridge and groove structure and cross-bladed fabric heretofore unique to some articulate brachiopods. A possible affinity with brachiopods or phoronids is suggested for
Tentaculites
.
Energy Balance for Ethyl Alcohol Production from Crops
Authors: da Silva José Gomes , Serra Gil Eduardo , Moreira José Roberto , Conçalves José Carlos , Goldemberg José
Published: October 2006

Energy requirements to produce ethyl alcohol from three different crops in Brazil (sugarcane, cassava, and sweet sorghum) were calculated. Figures are presented for the agricultural and industrial phases. The industrial phase is always more energy-intensive, consuming from 60 to 75 percent of the total energy. Sugarcane is the more efficient crop for ethyl alcohol production, followed by sweet sorghum and cassava from a net energy viewpoint. The utilization of sweet sorghum stems might increase the total energy gain from this crop to almost the same level as sugarcane. Cassava has a lower energy gain at the present state of agriculture in Brazil.
Quark Catalysis of Exothermal Nuclear Reactions
Authors: Zweig George
Published: October 2006

This article discusses circumstances under which free quarks catalyze exothermal nuclear reactions. It also presents possible methods for removing quarks sequestered by nuclear reaction products.

Stable quarks that are negatively charged and significantly heavier than electrons attract positively charged nuclei to form new states of matter. The nuclei and quarks are closely bound, and presumably interact through both electromagnetic and nuclear forces. Nuclear fusion and fission are possible, as well as a new class of plural reactions in which either a quark isobar, isotope, or isotone is created in each individual reaction, with catalysis resulting in the overall system because the net transfer of charge, neutrons, or protons to the quarks is zero. The quark with quantum numbers of
u̅u̅
is a promising catalytic candidate. A satisfactory understanding of which reactions are or are not possible awaits the isolation of free quarks and a description of their strong interactions with matter.

Finally, other kinds of stable negatively charged particles (such as heavy leptons), if discovered, can catalyze deuterium fusion reactions if thermal neutrons are used to liberate He
3
-bound catalytic particles.
Condensation of Nonequilibrium Phases of Refractory Silicates from the Vapor
Authors: Day Kenrick L. , Donn Bertram
Published: October 2006

Silicon monoxide solid was evaporated in a bell jar containing reducing, neutral, or oxidizing atmospheres at pressures of a few torr. The vapor invariably condensed as smoke-sized particles of silicon sesquioxide, Si
2
O
3
. The condensation of a solid whose composition differs from that of the parent gas and is apparently the least stable of the three solid species illustrates the importance of specific nucleation effects in the condensation process. This result has significant implications for theories of formation of grains in space.
Temperature Sensitivity: A Cell Character Determined by Obligate Endosymbionts in Amoebas
Authors: JEON K. W. , AHN T. I.
Published: October 2006

A strain of
Amoeba proteus
has lost its ability to survive at temperatures above 26°C as a result of becoming dependent on endosymbiotic bacteria that are psychrophile-like. The observed temperature sensitivity develops in fewer than 200 host cell generations (18 months of culture) after the host cells are experimentally infected with the symbionts.
Regulatory Role of Guanosine 3′,5′-Monophosphate in Adrenocorticotropin Hormone-Induced Steroidogenesis
Authors: Perchellet Jean-Pierre , Shanker Gouri , Sharma Rameshwar K.
Published: October 2006

The relation between steroidogenesis induced by adrenocorticotropic hormone and the concentrations of adenosine 3′,5′-monophosphate (cyclic AMP) and guanosine 3′,5′-monophosphate (cyclic GMP) was studied at different time intervals in isolated adrenal cells. Submaximal and supramaximal steroidogenic concentrations of the hormone did not cause detectable changes in cyclic AMP during the first 30 minutes, whereas there was an increase in the concentration of cyclic GMP that was accompanied by phosphorylation and steroidogenesis. It is therefore suggested that cyclic GMP, rather than cyclic AMP, is the physiological mediator of adrenocorticotropic hormone-induced adrenal steroidogenesis.
Life Below the Ross Ice Shelf, Antarctica
Authors: Lipps Jere H. , Ronan T. E. , DeLaca T. E.
Published: October 2006

Samples and observations under 420 meters of ice and 430 kilometers from the open sea on the Ross Ice Shelf at a water depth of 597 meters revealed an unusual assemblage of benthic organisms. Scavenging amphipods, an isopod, and fish were present but a living infauna was absent. The observations may be accounted for by sampling or spatial bias, or by extremely low or fluctuating trophic resources.
Carbon-13 Depletion in a Hydrothermal Vent Mussel: Suggestion of a Chemosynthetic Food Source
Authors: Rau Greg H. , Hedges John I.
Published: October 2006

Tissues of a mytilid mussel from the Clambake I hydrothermal vent in the Galápagos Rift zone are strikingly depleted in carbon-13 relative to the tissues of other marine organisms. The stable carbon isotope composition of this mussel suggests that chemoautotrophic bacteria present in the hydrothermal waters are a major food source for filter-feeding organisms in this abyssal environment.
Hydrogenase in
Rhizobium japonicum
Increases Nitrogen Fixation by Nodulated Soybeans
Authors: Albrecht Steve L. , Maier Robert J. , Hanus F. Joe , Russell Sterling A. , Emerich David W. , Evans Harold J.
Published: October 2006

Some
Rhizobium
strains synthesize a unidirectional hydrogenase system in legume nodule bacteroids; this system participates in the recycling of hydrogen that otherwise would be lost as a by-product of the nitrogen fixation process. Soybeans inoculated with
Rhizobium japonicum
strains that synthesized the hydrogenase system fixed significantly more nitrogen and produced greater yields than plants inoculated with strains lacking hydrogen-uptake capacity.
Rhizobium
strains used as inocula for legumes should have the capability to synthesize the hydrogenase system as one of their desirable characteristics.
Relationship Between the Oxygen Isotope Ratios of Terrestrial Plant Cellulose, Carbon Dioxide, and Water
Authors: DeNiro Michael J. , Epstein Samuel
Published: October 2006

The ratios of oxygen-18 to oxygen-16 (
18
O/
16
O) of cellulose purified from two sets of wheat plants grown under conditions similar in all respects except for a large difference in the
18
O/
16
O ratios of the carbon dioxide supplied to them differ by only a small amount. The difference in the
18
O/
16
O ratios of the cellulose is similar to that observed for the
18
O/
16
O ratios of the water present in the plants. These results indicate that the oxygen derived from carbon dioxide undergoes complete exchange with the oxygen of the water in the plant during the synthesis of cellulose and that the
18
O/
16
O ratio of the water inside the plant is the primary influence on the
18
O/
16
O ratio of cellulose in terrestrial plants.
Helium/Carbon Dioxide Ratios as Premonitors of Volcanic Activity
Authors: Thomas Donald M. , Naughton J. J.
Published: October 2006

The composition of the gaseous emissions of two fumaroles at the summit of Kilauea Volcano was monitored for more than 2 years. Magma was released from the summit reservoir on three occasions during this period; prior to or during each event the ratios of helium to carbon dioxide in the fumarole gases decreased substantially from that observed during periods of quiescence.
A New Mineralized Layer in the Hinge of the Oyster
Authors: Carriker Melbourne R. , Palmer Robert E.
Published: October 2006

A discrete, calcareous layer that binds the foliated calcite of the oyster's shell to the organic ligament in the hinge is reported, apparently for the first time. This layer is ultrastructurally, and generally mineralogically, different from the underlying foliated calcite, and is named the ligostracum.
Plasma Observations Near Jupiter: Initial Results from Voyager 2
Authors: Bridge H. S. , Belcher J. W. , Lazarus A. J. , Sullivan J. D. , Bagenal F. , McNutt R. L. , Ogilvie K. W. , Scudder J. D. , Sittler E. C. , Vasyliunas V. M. , Goertz C. K.
Published: October 2006

The first of at least nine bow shock crossings observed on the inbound pass of Voyager 2 occurred at 98.8 Jupiter radii (
R
J
) with final entry into the magnetosphere at 62
R
J
. On both the inbound and outbound passes the plasma showed a tendency to move in the direction of corotation, as was observed on the inbound pass of Voyager 1. Positive ion densities and electron intensities observed by Voyager 2 are comparable within a factor of 2 to those seen by Voyager 1 at the same radial distance from Jupiter; the composition of the magnetospheric plasma is again dominated by heavy ions with a ratio of mass density relative to hydrogen of about 100/1. A series of dropouts of plasma intensity near Ganymede may be related to a complex interaction between Ganymede and the magnetospheric plasma. From the planetary spin modulation of the intensity of plasma electrons it is inferred that the plasma sheet is centered at the dipole magnetic equator out to a distance of 40 to 50
R
J
and deviates from it toward the rotational equator at larger distances. The longitudinal excursion of the plasma sheet lags behind the rotating dipole by a phase angle that increases with increasing radial distance.
Images of Jupiter's Sulfur Ring
Authors: Pilcher Carl B.
Published: October 2006

Images of the ring of singly ionized sulfur encircling Jupiter obtained on two successive nights in April 1979 show that the ring characteristics may change dramatically in ∼ 24 hours. On the first night the ring was narrow and confined to the magnetic equator inside Io's orbit. On the second it was confined symmetrically about the centrifugal symmetry surface and showed considerable radial structure, including a "fan" extending to Io's orbit. Many of the differences in the ring on the two nights can be explained in terms of differences in sulfur plasma temperature.
Solar Ultraviolet Radiation and Coral Reef Epifauna
Authors: Jokiel Paul L.
Published: October 2006

Many "shade-loving" reef organisms show adverse effects when irradiated with full natural sunlight but not if radiation shorter than 400 nanometers is screened out. Shortwave solar radiation appears to be an important physical factor controlling the biology of shallow tropical benthic marine communities.
Swimming Ability of Carnivorous Dinosaurs
Authors: Coombs W. P.
Published: October 2006

Dinosaur tracks from Lower Jurassic rocks at Rocky Hill, Connecticut, were apparently made by a floating or half-submerged animal that was pushing along the bottom with the tips of its toes. These tracks were probably made by large carnivorous dinosaurs (Theropoda) and are apparently the first evidence of swimming by such animals.
Initial Solar Irradiance Determinations from Nimbus 7 Cavity Radiometer Measurements
Authors: Hickey J. R. , Stowe L. L. , Jacobowitz H. , Pellegrino P. , Maschhoff R. H. , House F. , Vonder Haar T. H.
Published: October 2006

Preliminary results from solar radiation measurements from the earth radiation budget experiment on the Nimbus 7 satellite yield a mean value of 1376.0 watts per square meter for the "solar constant" from 16 November 1978 to 15 May 1979. The observed variability (root-mean-square deviation) is ± 0.73 watt per square meter (± 0.05 percent) for the period.
Sediment Trap Experiment on the Galápagos Spreading Center, Equatorial Pacific
Authors: Cobler Richard , Dymond Jack
Published: October 2006

Two sediment traps were deployed for 234 days in 2670 meters of water at 0°36′N, 86°6′W. A comparison of the fluxes of ten elements into the traps and into the surface sediment indicates that the refractory elements iron, aluminum, and barium are accumulating in the sediments at rates very similar to those measured in the traps. In contrast, at least 80 percent of the opal, 50 percent of the carbonate, and 90 percent of the organic carbon is consumed at the sediment-water interface.
Induction of Suspension Feeding in Spionid Polychaetes by High Particulate Fluxes
Authors: Taghon Gary L. , Nowell Arthur R. M. , Jumars Peter A.
Published: October 2006

The feeding behavior of three species of spionid polychaetes varied with water velocity. At moderate flows the worms ceased deposit feeding, formed their feeding tentacles into helices, and lifted them into the water column to capture material in suspension. This behavior was apparently a response to increased flux of suspended matter at high flows rather than to flow velocity alone. Organisms capable of switching their feeding behavior may be common in dynamically variable benthic environments.
Hormesis: A Response to Low Environmental Concentrations of Petroleum Hydrocarbons
Authors: Laughlin Roy B. , Ng James , Guard Harold E.
Published: October 2006

Crab zoeae (
Rhithropanopeus harrisii
) were exposed to water-soluble fractions of jet fuel (JP5) for the first 5 days or for the duration of zoeal development (11 to 14 days). Short-term exposure or continuous exposure to low concentrations of petroleum hydrocarbons caused no increase in mortality or changes in development rate, and increased megalopal weight was characteristic of such groups. This phenomenon, termed "hormesis," is probably a generalized aspect of environmental stress etiology but has seldom been reported as such.
Airborne Studies of the Emissions from the Volcanic Eruptions of Mount St. Helens
Authors: Hobbs Peter V. , Radke Lawrence F. , Eltgroth Mark W. , Hegg Dean A.
Published: October 2006

The concentrations of particles less than 10 micrometers in diameter in the ash emissions from Mount St. Helens have been more than 1000 times greater than those in the ambient air. Mass loadings of particles less than 2 micrometers in diameter were generally several hundred micrograms per cubic meter. In the ash clouds, produced by the large eruption on 18 May 1980, the concentrations of several trace gases generally were low. In other emissions, significant, but variable, concentrations of sulfur gases were measured. The 18 May eruption produced nuées ardentes, lightning flashes, and volcanic hail.
The Cellular Functions of Small GTP-Binding Proteins
Authors: Hall Alan
Published: October 2006

A substantial number of novel guanine nucleotide binding regulatory proteins have been identified over the last few years but the function of many of them is largely unknown. This article will discuss a particular family of these proteins, structurally related to the Ras oncoprotein. Approximately 30 Ras-related small guanosine triphosphate (GTP)-binding proteins are known, and from yeast to man they appear to be involved in controlling a diverse set of essential cellular functions including growth, differentiation, cytoskeletal organization, and intracellular vesicle transport and secretion.
Induction of Donor-Specific Unresponsiveness by Intrathymic Islet Transplantation
Authors: Posselt Andrew M. , Barker Clyde F. , Tomaszewski John E. , Markmann James F. , Choti Michael A. , Naji Ali
Published: October 2006

The application of isolated pancreatic islet transplantation for treatment of diabetes mellitus has been hampered by the vulnerability of islet allografts to immunologic rejection. Rat islet allografts that were transplanted into the thymus of recipients treated with a single injection of anti-lymphocyte serum survived indefinitely. A state of donor-specific unresponsiveness was achieved that permitted survival of a second donor strain islet allograft transplanted to an extrathymic site. Maturation of T cell precursors in a thymic microenvironment that is harboring foreign alloantigen may induce the selective unresponsiveness. This model provides an approach for pancreatic islet transplantation and a potential strategy for specific modification of the peripheral immune repertoire.
Carbonyl Sulfide: Potential Agent of Atmospheric Sulfur Corrosion
Authors: Graedel T. E. , Kammlott G. W. , Franey J. P.
Published: October 2006

Laboratory exposure experiments demonstrate that carbonyl sulfide in wet air corrodes copper at 22°C at a rate that is approximately linear with total exposure (the product of exposure time and carbonyl sulfide concentration). The corrosion rate is similar to that of hydrogen sulfide, a widely recognized corrodant. The much greater average atmospheric abundance of carbonyl sulfide compared with that of hydrogen sulfide or sulfur dioxide suggests that carbonyl sulfide may be a major agent of atmospheric sulfur corrosion.
Miocene Stable Isotope Record: A Detailed Deep Pacific Ocean Study and Its Paleoclimatic Implications
Authors: Woodruff Fay , Savin Samuel M. , Douglas Robert G.
Published: October 2006

Deep Sea Drilling Project site 289 in the western equatorial Pacific has yielded an extremely detailed record of the carbon and oxygen isotopic changes in the Miocene deep ocean. The isotopic record reflects major changes in paleoclimate and paleoceanography, probably dominated by a major phase of Antarctic ice-cap growth. The transition from a relatively unglaciated world to one similar to today occurred between 16.5 × 10
6
and 13 × 10
6
years before the present, with the greatest change occurring between approximately 14.8 × 10
6
and 14.0 × 10
6
years before the present.
Origins of Chirality in Nature: A Reassessment of the Postulated Role of Bentonite
Authors: Youatt J. B. , Brown R. D.
Published: October 2006

Bondy and Harrington have proposed that selective binding of L isomers of amino acids and D isomers of sugars to bentonite is the mechanism by which the chirality of molecules in living cells was originally established. Further experiments indicate that the observations of Bondy and Harrington are better explained in terms of the effects of the binding to bentonite of the products of radiochemical decomposition.
Peripheral Clonal Elimination of Functional T Cells
Authors: Jones Lori A. , Chin L. Thomas , Longo Dan L. , Kruisbeek Ada M.
Published: October 2006

A major mechanism for generating tolerance in developing T cells is the intrathymic clonal deletion of T cells that have receptors for those self antigens that are presented on hematopoietic cells. The mechanisms of tolerance induction to antigens not expressed in the thymus remain unclear. Tolerance to self antigens can be generated extrathymically through the induction of clonal nonresponsiveness in T cells with self-reactive receptors. A second mechanism of extrathymic tolerance was identified: clonal elimination of mature T cells with self-reactive receptors that had previously displayed functional reactivity.
Detection of Overflow Events in the Shag Rocks Passage, Scotia Ridge
Authors: Zenk Walter
Published: October 2006

During an almost yearlong period of observations made with a current meter in the fracture zone between the Falkland Islands (Islas Malvinas) and South Georgia, several overflow events were recorded at a depth of 3000 meters carrying cold bottom water from the Scotia Sea into the Argentine Basin. The outflow bursts of Scotia Sea bottom water, a mixing product of Weddell Sea and eastern Pacific bottom water, were associated with typical speeds of more than 28 centimeters per second toward the northwest and characteristic temperatures below 0.6°C. The maximum 24-hour average speed of 65 centimeters per second, together with a temperature of 0.29°C, was encountered on 14 November 1980 at a water depth of 2973 meters, 35 meters above the sea floor.
Antiphase Domains and Reverse Thermoremanent Magnetism in Ilmenite-Hematite Minerals
Authors: Lawson Charles A. , Nord Gordon L. , Dowty Eric , Hargraves Robert B.
Published: October 2006

Examination of synthetic ilmenite-hematite samples by transmission electron microscopy has for the first time revealed the presence of well-defined antiphase domains and antiphase domain boundaries in this mineral system. Samples quenched from 1300°C have a high density of domain boundaries, whereas samples quenched from 900°C have a much lower density. Only the high-temperature samples acquire reverse thermoremanent magnetism when cooled in an applied magnetic field. The presence of a high density of domain boundaries seems to be a necessary condition for the acquisition of reverse thermoremanent magnetism.
Hurricane Allen's Impact on Jamaican Coral Reefs
Authors: Woodley J. D. , Chornesky E. A. , Clifford P. A. , Jackson J. B. C. , Kaufman L. S. , Knowlton N. , Lang J. C. , Pearson M. P. , Porter J. W. , Rooney M. C. , Rylaarsdam K. W. , Tunnicliffe V. J. , Wahle C. M. , Wulff J. L. , Curtis A. S. G. , Dallmeyer M. D. , Jupp B. P. , Koehl M. A. R. , Neigel J. , Sides E. M.
Published: October 2006

Coral reefs of north Jamaica, normally sheltered, were severely damaged by Hurricane Allen, the strongest Caribbean hurricane of this century. Immediate studies were made at Discovery Bay, where reef populations were already known in some detail. Data are presented to show how damage varied with the position and orientation of the substratum and with the shape, size, and mechanical properties of exposed organisms. Data collected over succeeding weeks showed striking differences in the ability of organisms to heal and survive.
Airborne Lead and Other Elements Derived from Local Fires in the Himalayas
Authors: Davidson Cliff I. , Grimm Thomas C. , Nasta Margaret A.
Published: October 2006

The combustion of wood and yak dung for heating and cooking in a populated Nepal Himalayan valley contributes significantly to the ambient airborne concentrations of lead, copper, aluminum, magnesium, and elemental and organic carbon. A comparison of the concentrations of these elements in fresh snow with corresponding values in air suggests that the pollution aerosol is confined to the valley, with pristine air aloft.
The Pineal Gland: A Biological Clock in Vitro
Authors: Binkley Sue A. , Riebman J. B. , Reilly K. B.
Published: October 2006

Circadian rhythmicity was studied by following the course of N-acetyl-transferase activity in the pineal glands of chickens in vitro. The results indicate (i) a daily change during day 1 of organ culture in constant dark that was dependent on the time the chickens were killed, (ii) equivocal persistence of the daily change in constant dark during 6 to 7 days of organ culture, (iii) an effect of light, (iv) inhibition by adrenergic agents and cycloheximide, and (v) stimulation by dibutyryl adenosine 3′,5′-monophosphate and related compounds.
Delayed Light Imaging for the Early Detection of Plant Stress
Authors: Ellenson James L. , Amundson Robert G.
Published: October 2006

Image-intensified photographs of delayed light emission (DLE) from soybean leaves exposed to sulfur dioxide showed evidence of the stress that developed during the exposure period. A comparison of DLE images taken during the fumigation with a conventional photograph taken 5 days later showed a clear correspondence between leaf areas that had the most diminished DLE intensity and those that showed the greatest visible injury. These results suggest that DLE imagery will be a useful tool in the investigation of the spatial distribution and temporal development of plant stress.
Territoriality and the Origin of Slave Raiding in Leptothoracine Ants
Authors: Stuart Robin J. , Alloway Thomas M.
Published: October 2006

The slave-raiding behavior of
Harpagoxenus canadensis
closely resembles the territorial behavior of its host species,
Leptothorax muscorum
. Of primary importance is the discovery that both species of ants recruit nest mates into battle using an alarm-recruitment system which is a probable evolutionary precursor of more specialized forms of slave-raiding recruitment. The behavior of these species supports the hypothesis that slave raiding in leptothoracine ants evolved from territorial behavior.
Lumber Spill in Central California Waters: Implications for Oil Spills and Sea Otters
Authors: VanBlaricom Glenn R. , Jameson Ronald J.
Published: October 2006

A large quantity of lumber was spilled in the ocean off central California during the winter of 1978, and it spread through most of the range of the threatened California sea otter population within 4 weeks. The movement rates of lumber were similar to those of oil slicks observed elsewhere. These observations indicate that a major oil spill could expose significant numbers of California sea otters to oil contamination.
Coal Gasification for Electric Power Generation
Authors: Spencer Dwain F. , Gluckman Michael J. , Alpert Seymour B.
Published: October 2006

The electric utility industry is being severely affected by rapidly escalating gas and oil prices, restrictive environmental and licensing regulations, and an extremely tight money market. Integrated coal gasification combined cycle (IGCC) power plants have the potential to be economically competitive with present commercial coal-fired power plants while satisfying stringent emission control requirements. The current status of gasification technology is discussed and the critical importance of the 100-megawatt Cool Water IGCC demonstration program is emphasized.
Transplantation of the Cockroach Circadian Pacemaker
Authors: Page Terry L.
Published: October 2006

Surgical removal of the optic lobes of the cockroach
Leucophaea maderae
followed by transplantation of the optic lobes from another individual led to a restoration of the circadian activity rhythm in 4 to 8 weeks. The free-running period of the restored rhythm was determined by the period of the donor rhythm before surgery. The results suggest that the transplanted optic lobe contains a circadian clock that regenerates those neural connections with the host brain that are necessary to drive the circadian rhythm of activity.
Photoprotection by Carotenoids During Photosynthesis: Motional Dependence of Intramolecular Energy Transfer
Authors: Moore Ana L. , Joy Anna , Tom Roderick , Gust Devens , Moore Thomas A. , Bensasson René V. , Land Edward J.
Published: October 2006

A new carotenoporphyrin has been prepared in which a synthetic carotenoid is joined to a tetraarylporphyrin through a flexible trimethylene linkage. This molecule exists primarily in an extended conformation with the carotenoid chromophore far from the porphyrin π-electron system. In benzene solution, where large-amplitude molecular motions are rapid, the molecule can momentarily assume less stable conformations which favor triplet energy transfer, and quenching of the porphyrin triplet by the carotenoid is fast. In a polystyrene matrix or frozen glass such motions are slow, and energy transfer cannot compete with other pathways for depopulating the triplet state. These observations help establish the requirements for biological photoprotection.
Skirt Clouds Associated with the Soufriere Eruption of 17 April 1979
Authors: Barr Sumner
Published: October 2006

A fortuitous and dramatic photograph of the Soufriere eruption column of 17 April 1979 displays a series of highly structured skirt clouds. The gentle distortion of thin, quasi-horizontal layers of moist air has been documented in meteorological situations. It is proposed that at St. Vincent subhorizontal layers of moist air were intensely deformed by the rapidly rising eruption column and were carried to higher altitudes, where they condensed to form the skirt clouds.
Low-Frequency Eddy Kinetic Energy Spectrum in the Deep Western North Pacific
Authors: Imawaki S. , Takano K.
Published: October 2006

The frequency spectrum for the low-frequency eddy kinetic energy is estimated from a long-term current meter record obtained in a deep layer in the western North Pacific. The eddy field is characterized by three time scales: an "annual scale" with zonal dominance of eddy motions, a "temporal mesoscale" with meridional dominance, and a "monthly scale" with horizontal isotropy. About two-thirds of the eddy kinetic energy is contained in the temporal mesoscale.
Rotaviral Immunity in Gnotobiotic Calves: Heterologous Resistance to Human Virus Induced by Bovine Virus
Authors: Wyatt Richard G. , Mebus Charles A. , Yolken Robert H. , Kalica Anthony R. , James Harvey D. , Kapikian Albert Z. , Chanock Robert M.
Published: October 2006

The possibility of immunizing human infants against rotaviruses, which cause severe dehydrating diarrheal disease, may depend on the use of a related rotavirus, derived from another animal species, as a source of antigen. To test the feasibility of this approach, calves were infected in utero with a bovine rotavirus and challenged with bovine or human type 2 rotavirus shortly after birth. Infection in utero with bovine rotavirus induced resistance to diarrheal disease caused by the human virus as well as the homologous bovine virus. These data suggest that the bovine virus is sufficiently related antigenically to the human type 2 virus to warrant further evaluation of the former as a source of vaccine.
Cell Cycle Dependence of Chloride Permeability in Normal and Cystic Fibrosis Lymphocytes
Authors: Bubien James K. , Kirk Kevin L. , Rado Thomas A. , Frizzell Raymond A.
Published: October 2006

Cystic fibrosis (CF) is a genetic disease characterized by abnormal regulation of epithelial cell chloride channels. Nonepithelial cells, including lymphocytes and fibroblasts, may exhibit a similar defect. Two independent techniques were used to assess the macroscopic chloride permeability (
P
Cl
) of freshly isolated B lymphocytes and of B and T lymphocyte cell lines. Values for
P
Cl
increased specifically during the G
1
phase of the cell cycle and could be further enhanced by increasing intracellular adenosine 3′,5′-monophosphate (cAMP) or calcium. In lymphocytes from CF patients, regulation of
P
Cl
during the cell cycle and by second messengers was absent. Characterization of the cell cycle-dependent expression of the chloride permeability defect in lymphocytes from CF patients increases the utility of these cells in the analysis of the functional consequences of mutations in the CF gene.
Isotopic Composition of Neodymium in Waters from the Drake Passage
Authors: Piepgras Donald J. , Wasserburg G. J.
Published: October 2006

The isotopic composition of neodymium has been determined in seawaters from the Drake Passage. The Antarctic Circumpolar Current, which controls interocean mixing, flows through this passage. The parameter ε
Nd
(0), which is a function of the ratio of neodymium-143 to neodymium-144, is found to be uniform with depth at two stations with a value which is intermediate between the values for the Atlantic and the Pacific and indicates that the Antarctic Circumpolar Current consists of about 70 percent Atlantic water. Cold bottom water from a site in the south central Pacific has the neodymium isotopic signature of the waters in the Drake Passage. By using a box model to describe the exchange of water between the Southern Ocean and the ocean basins to the north together with the isotopic results, an upper limit of approximately 33 million cubic meters per second is calculated for the rate of exchange between the Pacific and the Southern Ocean. Concentrations of samarium and neodymium were also determined and found to increase approximately linearly with depth. These results suggest that neodymium may be a valuable tracer in oceanography and may be useful in paleo-oceanographic studies.