Myxotyrosides A and B, Unusual rhamnosides from Myxococcus sp.

PubMed

Ohlendorf, Birgit; Lorenzen, Wolfram; Kehraus, Stefan; Krick, Anja; Bode, Helge B; König, Gabriele M

2009-01-01

Myxobacteria are gliding bacteria of the delta-subdivision of the Proteobacteria and known for their unique biosynthetic capabilities. Two examples of a new class of metabolites, myxotyrosides A (1) and B (2), were isolated from a Myxococcus sp. The myxotyrosides have a tyrosine-derived core structure glycosylated with rhamnose and acylated with unusual fatty acids such as (Z)-15-methyl-2-hexadecenoic and (Z)-2-hexadecenoic acid. The fatty acid profile of the investigated Myxococcus sp. (strain 131) is that of a typical myxobacterium with a high similarity to those described for M. fulvus and M. xanthus, with significant concentrations of neither 15-methyl-2-hexadecenoic acid nor 2-hexadecenoic acid being detected.

The source of Witwatersrand gold: evidence from uraninite chemistry

USGS Publications Warehouse

Frimmel, Hartwig E.; Emsbo, Poul; Koenig, Alan E.

2009-01-01

An in-situ LA-ICP-MS study of different generations of uraninite from the Mesoarchaean Witwatersrand gold palaeoplacer deposits revealed unusually high Au concentrations in rounded, detrital uraninite grains but no detectable Au in secondary, hydrothermally mobilised uraninite. A Au-enriched uraninite-bearing magmatic host is suggested as a significant source for detrital gold in the Witwatersrand sediments.

Controls on porphyrin concentrations of Pennsylvanian organic-rich shales, Western U.S.A.

USGS Publications Warehouse

Clayton, J.L.; Michael, G.E.

1990-01-01

Organic-rich black shales of Middle Pennsylvanian (Desmoinesian) age occur over much of the central U.S. and as far west as the northern Denver and southeastern Powder River basins. Total organic carbon contents (Corg) are commonly greater than 10 wt %. Porphyrin concentrations (vanadyl + nickel) are as high as 40000 ppm relative to extractable bitumen. In bulk, the organic matter contained in the shales is mostly type II and III (Rock-Eval hydrogen indexes 200-400 mg of hydrocarbons/g of Corg). The finding of high porphyrin concentrations in type III organic matter is unusual but can be explained by a depositional model wherein high preservation of primary organic production (water column photosynthesis) is combined with substantial input of allochthonous organic matter. The allochthonous organic matter (low porphyrin concentration) may come from erosion during advance of the sea across the area or from fluvial transport from shore.

Oxidative tryptophan modification by terpene- and squalene-hydroperoxides and a possible link to cross-reactions in diagnostic tests.

PubMed

Natsch, Andreas; Emter, Roger; Badertscher, Remo P; Brunner, Gerhard; Granier, Thierry; Kern, Susanne; Ellis, Graham

2015-06-15

Hydroperoxides can act as specific haptens and oxidatively modify proteins. Terpene hydroperoxides trigger unusually high frequencies of positive skin reactions in human patients if tested at high concentrations. It is unknown whether this is due to specific hapten formation. Here, we show that both terpene hydroperoxides and the endogenous hydroperoxide formed from squalene can oxidatively modify tryptophan. Oxidative modifications of Trp were recently postulated to explain cross-sensitization between unrelated photosensitizers. Current observations may extend this hypothesis: Oxidative events triggered by endogenous hydroperoxides and hydroperoxides/oxidants derived from xenobiotics might lead to a sensitized state detected by patch tests with high concentrations of hydroperoxides.

Doppler line profiles measurement of the Jovian Lyman Alpha emission with OAO-C

NASA Technical Reports Server (NTRS)

Barker, E. S.; Cochran, W. D.; Smith, H. J.

1982-01-01

Observation of Jupiter made with the high resolution ultraviolet spectrometer of the Orbiting Astronomical Observatory copernicus in April and May, 1980, yield a Jovian Lyman alpha emission intensity of 7 + or 2.5 RR. This indicates a decrease by about a factor of two since the Voyager ultraviolet spectrometer measurements, nearly a year earlier. An unusually high column abundance of hydrogen atoms above the methane homopause at the Voyager epoch is indicated. Since the auroral charged particle bombardment of molecular hydrogen is expected to contribute significantly to the global population of the hydrogen atoms, it is suggested that at the time of the Voyager Jupiter encounter unusually high auroral activity existed, perhaps d to the high concentration of the Io plasma torus. The temporal variation of the Saturn lyman alpha emission, when contrasted with the Jovian data, reveals that the auroral processes are not nearly as important in determining the Saturn Lyman alpha intensity in the nonauroral region.

Unusual Passivation Ability of Superconcentrated Electrolytes toward Hard Carbon Negative Electrodes in Sodium-Ion Batteries.

PubMed

Takada, Koji; Yamada, Yuki; Watanabe, Eriko; Wang, Jianhui; Sodeyama, Keitaro; Tateyama, Yoshitaka; Hirata, Kazuhisa; Kawase, Takeo; Yamada, Atsuo

2017-10-04

The passivation of negative electrodes is key to achieving prolonged charge-discharge cycling with Na-ion batteries. Here, we report the unusual passivation ability of superconcentrated Na-salt electrolytes. For example, a 50 mol % sodium bis(fluorosulfonyl)amide (NaFSA)/succinonitrile (SN) electrolyte enables highly reversible Na + insertion into a hard carbon negative electrode without any electrolyte additive, functional binder, or electrode pretreatment. Importantly, an anion-derived passivation film is formed via preferential reduction of the anion upon charging, which can effectively suppress further electrolyte reduction. As a structural characteristic of the electrolyte, most anions are coordinated to multiple Na + cations at high concentration, which shifts the lowest unoccupied molecular orbitals of the anions downward, resulting in preferential anion reduction. The present work provides a new understanding of the passivation mechanism with respect to the coordination state of the anion.

Tuning of superconductivity by Ni substitution into noncentrosymmetric ThC o1 -xN ixC2

NASA Astrophysics Data System (ADS)

Grant, T. W.; Cigarroa, O. V.; Rosa, P. F. S.; Machado, A. J. S.; Fisk, Z.

2017-07-01

The recently discovered noncentrosymmetric superconductor ThCoC2 was observed to show unusual superconducting behavior with a critical temperature of Tc=2.65 K . Here we investigate the effect of nickel substitution on the superconducting state in ThC o1 -xN ixC2 . Magnetization, resistivity, and heat capacity measurements demonstrate Ni substitution has a dramatic effect with critical temperature increased up to Tc=12.1 K for x =0.4 Ni concentration, which is a rather high transition temperature for a noncentrosymmetric superconductor. In addition, the unusual superconducting characteristics observed in pure ThCoC2 appear to be suppressed or tuned with Ni substitution towards a more conventional fully gapped superconductor.

Extremely high intracellular concentration of glucose-6-phosphate and NAD(H) in Deinococcus radiodurans.

PubMed

Yamashiro, Takumi; Murata, Kousaku; Kawai, Shigeyuki

2017-03-01

Deinococcus radiodurans is highly resistant to ionizing radiation and UV radiation, and oxidative stress caused by such radiations. NADP(H) seems to be important for this resistance (Slade and Radman, Microbiol Mol Biol Rev 75:133-191; Slade, Radman, Microbiol Mol Biol Rev 75:133-191, 2011), but the mechanism underlying the generation of NADP(H) or NAD(H) in D. radiodurans has not fully been addressed. Intracellular concentrations of NAD + , NADH, NADP + , and NADPH in D. radiodurans are also not determined yet. We found that cell extracts of D. radiodurans catalyzed reduction of NAD(P) + in vitro, indicating that D. radiodurans cells contain both enzymes and a high concentration of substrates for this activity. The enzyme and the substrate were attributed to glucose-6-phosphate dehydrogenase and glucose-6-phosphate of which intracellular concentration was extremely high. Unexpectedly, the intracellular concentration of NAD(H) was also much greater than that of NADP(H), suggesting some significant roles of NADH. These unusual features of this bacterium would shed light on a new aspect of physiology of this bacterium.

Exposure to atmospheric radon.

PubMed Central

Steck, D J; Field, R W; Lynch, C F

1999-01-01

We measured radon (222Rn) concentrations in Iowa and Minnesota and found that unusually high annual average radon concentrations occur outdoors in portions of central North America. In some areas, outdoor concentrations exceed the national average indoor radon concentration. The general spatial patterns of outdoor radon and indoor radon are similar to the spatial distribution of radon progeny in the soil. Outdoor radon exposure in this region can be a substantial fraction of an individual's total radon exposure and is highly variable across the population. Estimated lifetime effective dose equivalents for the women participants in a radon-related lung cancer study varied by a factor of two at the median dose, 8 mSv, and ranged up to 60 mSv (6 rem). Failure to include these doses can reduce the statistical power of epidemiologic studies that examine the lung cancer risk associated with residential radon exposure. Images Figure 1 Figure 2 Figure 3 Figure 4 PMID:9924007

Mg-spinel lithology: A new rock type on the lunar farside

USGS Publications Warehouse

Pieters, C.M.; Besse, S.; Boardman, J.; Buratti, B.; Cheek, L.; Clark, R.N.; Combe, J.-P.; Dhingra, D.; Goswami, J.N.; Green, R.O.; Head, J.W.; Isaacson, P.; Klima, R.; Kramer, G.; Lundeen, S.; Malaret, E.; McCord, T.; Mustard, J.; Nettles, J.; Petro, N.; Runyon, C.; Staid, M.; Sunshine, J.; Taylor, L.A.; Thaisen, K.; Tompkins, S.; Whitten, J.

2011-01-01

High-resolution compositional data from Moon Mineralogy Mapper (M 3) for the Moscoviense region on the lunar farside reveal three unusual, but distinctive, rock types along the inner basin ring. These are designated "OOS" since they are dominated by high concentrations of orthopyroxene, olivine, and Mg-rich spinel, respectively. The OOS occur as small areas, each a few kilometers in size, that are widely separated within the highly feldspathic setting of the basin rim. Although the abundance of plagioclase is not well constrained within the OOS, the mafic mineral content is exceptionally high, and two of the rock types could approach pyroxenite and harzburgite in composition. The third is a new rock type identified on the Moon that is dominated by Mg-rich spinel with no other mafic minerals detectable (<5% pyroxene, olivine). All OOS surfaces are old and undisturbed since basin formation. They are effectively invisible in image data and are only recognized by their distinctive composition identified spectroscopically. The origin of these unusual lithologies appears to be linked to one or more magmatic intrusions into the lower crust, perhaps near the crust-mantle interface. Processes such as fractional crystallization and gravity settling within such intrusions may provide a mechanism for concentrating the mafic components within zones several kilometers in dimension. The OOS are embedded within highly anorthositic material from the lunar crust; they may thus be near contemporaneous with crustal products from the cooling magma ocean. Copyright ?? 2011 by the American Geophysical Union.

Unusual concentration-dependent microscopic dynamics of dendrimers in aqueous solution

NASA Astrophysics Data System (ADS)

Wong, Kaikin; Wu, Chin Ming; Lam, Hak Fai; Chathoth, Suresh M.

2016-05-01

Dendrimers are novel three-dimensional, hyperbranched globular nanopolymeric macromolecules. The nanoscopic size, narrow polydispersity index, excellent control over molecular structure, availability of multiple functional groups at the periphery, and cavities in the interior made them very attractive candidate for drug delivery. In this communication, we have studied the microscopic dynamics of tetra-acid and pentaerythritol glycidyl ether dendrimers dissolved in aqueous solution with different concentrations. The effects of concentration and temperature to their long-range diffusion process are investigated by dynamic light scattering. Experimental results show a huge variation in the translational diffusion coefficient for the two dendrimers samples. Besides, the dependence of diffusion coefficients on concentration is unusually different in these dendrimer samples. Although the diffusion process follows Arrhenius relation with the temperature in both systems, the activation energy for the diffusion process has a distinct concentration dependence.

Cerro Xalapaxco: An Unusual Tuff Cone with Multiple Explosion Craters, in Central Mexico (Puebla)

NASA Technical Reports Server (NTRS)

Abrams, M. J.; Siebe, C.

1994-01-01

The Xalapaxco tuff cone is located on the northeast flank of La Malinche stratovolcano in central Mexico. An unusually large number (10) of explosion craters, concentrated on the central and on the uphill side of the cone, expose alternating beds of stratified surge deposits and massive fall deposits.

Unusual properties of aqueous solutions of L-proline: A molecular dynamics study

NASA Astrophysics Data System (ADS)

Civera, Monica; Sironi, Maurizio; Fornili, Sandro L.

2005-11-01

Aqueous solutions of the bioprotectant proline are simulated for solute molar fractions ranging from 2.0 × 10 -3 to 2.3 × 10 -1. Statistical analyses show that proline affects the water structure more strongly than glycine betaine and trimethylamine- N-oxide, two of the most effective bioprotectants widely diffuse in nature, and as strongly as tert-butyl alcohol, a protein denaturant which at high concentration self-aggregates. No evidence is found, however, that proline self-aggregates as it has been previously suggested to explain experimental findings on concentrated proline solutions. Nevertheless, the behavior of the diffusion coefficients of proline and water vs. solute concentration qualitatively agrees with such results.

Spectroscopic investigation of inner filter effect by magnolol solutions

NASA Astrophysics Data System (ADS)

Li, Hongmei; YuzhuHu

2007-12-01

Spectroscopy is useful tool for aggregation studies on fluorephores. One of the major problems with this technique is that the inner filter effect becomes unavoidable since the samples are used at high concentration. In this work, our investigation on magnolol spectroscopic properties shows that the inner filter effect (IFE) of fluorescence plays a critical role in the spectra of magnolol. The strong dependence of the fluorescence parameters on the concentration accounts for the apparent experimental evidence of magnolol aggregation at high concentrations. There are some questions despite the aggregation model based on fluorescent aggregates seems to describe the behavior of the system. The mathematical correction on the emission intensities shows the linear fluorescence-concentration relationship. Furthermore, we propose a mathematic model of excitation spectrum based on the primary IFE (absorption of light of excitation wavelength), which provide a correct explanation of the unusual spectral shift and spectral narrowing in the excitation spectra of magnolol at high concentrations. The shapes of spectra are completely independent on magnolol aggregation and are due only to experimental artifacts, i.e. IFE.

Fogwater chemistry in an urban atmosphere

NASA Astrophysics Data System (ADS)

Munger, J. William; Jacob, Daniel J.; Waldman, Jed M.; Hoffmann, Michael R.

1983-06-01

Analyses of fogwater collected by inertial impaction in the Los Angeles basin and the San Joaquin Valley indicated unusually high concentrations of major and minor ions. The dominant ions measured were NO3-, SO42-, NH4+, and H+. Nitrate exceeded sulfate on an equivalent basis by a factor of 2.5 in the central and coastal regions of the Los Angeles basin but was approximately equal in the eastern Los Angeles basin and the San Joaquin Valley. Maximum observed values for NH4+, NO3-, and SO42- were 10.0, 12.0, and 5.0, meq 1-1, while the lowest p;H observed was 2.2. Iron and lead concentrations of over 0.1 mM and 0.01 mM, respectively, were observed. High concentrations of chemical components in fog appeared to correlate well with the occurrence of smog events. Concentrations in fogwater were also affected by the physical processes of condensation and evaporation. Light, dissipating fogs routinely showed the highest concentrations.

Analysis of dinosaur samples by nuclear microscopy

NASA Astrophysics Data System (ADS)

Wu, Xiankang; Orlić, I.; Tang, S. M.; Wang, Yiming; Wang, Xiaohong; Zhu, Jieqing

1997-07-01

Several dinosaur bone and eggshell fossil samples unearthed at different sites in China were analyzed by means of nuclear microscopy. Concentrations and distributions of elements such as Na, Mg, Al, P, S, Ca, Cr, Mn, Fe, Cu, Zn, As, Br, Sr, Y, Ce, Pb and U, etc. were obtained for each sample. The results of quantitative PIXE and RBS analyses show unusually high concentrations of U and Ce in several samples obtained from a period near the K-T boundary (between Cretaceous and Tertiary periods, 65 million years ago), suggesting that some form of environmental pollution could be the cause of dinosaur extinction.

In vitro activity of daptomycin against clinical isolates of Gram-positive bacteria.

PubMed

Piper, Kerryl E; Steckelberg, James M; Patel, Robin

2005-08-01

We determined the activity of daptomycin, a recently FDA-approved antimicrobial agent, against clinical isolates of Gram-positive bacteria, including viridans group streptococci (16 Streptococcus mitis species group, 12 S. mutans species group, 9 S. anginosus species group, 8 S. sanguinis species group, 5 S. salivarius species group) from patients with infective endocarditis, 32 methicillin-resistant Staphylococcus aureus, 32 high-level penicillin-resistant Streptococcus pneumoniae, 38 vancomycin-resistant enterococci (including 1 linezolid-resistant isolate), and the following unusual Gram-positive bacteria: 3 Listeria monocytogenes, 4 Erysipelothrix rhusiopathiae, 9 Corynebacterium species, 10 Abiotrophia/Granulicatella species, 2 Rothia (Stomatococcus) mucilaginosus, and 4 Gemella morbillorum. Daptomycin minimum inhibitory concentration (MIC)(90) values for the viridans group streptococci, methicillin-resistant S. aureus, penicillin-resistant S. pneumoniae, and Enterococcus species were 0.5, 0.5, < or =0.125, and 4 microg/ml, respectively. The daptomycin MIC range for the unusual Gram-positive bacteria was < or =0.125-2 microg/ml. We conclude that daptomycin has in vitro activity against viridans group streptococci associated with endocarditis as well as against several types of unusual Gram-positive bacteria that can cause endocarditis.

Supramolecular "Big Bang" in a Single-Ionic Surfactant/Water System Driven by Electrostatic Repulsion: From Vesicles to Micelles.

PubMed

Leclercq, Loïc; Bauduin, Pierre; Nardello-Rataj, Véronique

2017-04-11

In aqueous solution, dimethyldi-n-octylammonium chloride, [DiC 8 ][Cl], spontaneously forms dimers at low concentrations (1-10 mM) to decrease the strength of the hydrophobic-water contact. Dimers represent ideal building blocks for the abrupt edification of vesicles at 10 mM. These vesicles are fully characterized by dynamic and static light scattering, self-diffusion nuclear magnetic resonance, and freeze-fracture transmission electron microscopy. An increase in concentration leads to electrostatic repulsion between vesicles that explode into small micelles at 30 mM. These transitions are detected by means of surface tension, conductivity, and solubility of hydrophobic solutes as well as by isothermal titration microcalorimetry. These unusual supramolecular transitions emerge from the surfactant chemical structure that combines two contradictory features: (i) the double-chain structure tending to form low planar aggregates with low water solubility and (ii) the relatively short chains giving high hydrophilicity. The well-balanced hydrophilic-hydrophobic character of [DiC 8 ][Cl] is then believed to be at the origin of the unusual supramolecular sequence offering new opportunities for drug delivery systems.

Myopericytoma proliferating in an unusual anastomosing multinodular fashion.

PubMed

Inoue, Takuya; Misago, Noriyuki; Asami, Akihiko; Tokunaga, Osamu; Narisawa, Yutaka

2016-05-01

We herein describe a case of myopericytoma that proliferated in an unusual fashion. Myopericytoma is described as a group of rare, benign, dermal or subcutaneous tumors that are characterized histologically by a striking, concentric, perivascular proliferation of spindle cells and showing apparent differentiation towards perivascular myoid cells. Myopericytoma forms a morphological continuum with myofibroma/myofibromatosis, glomus tumor and angioleiomyoma. The patient was a 64-year-old woman who demonstrated a recurrent ulcer on an atrophic plaque on her left shin. A histopathological examination of the plaque demonstrated that tumor cells proliferated in an anastomosing multinodular fashion along the vessels in the dermis and subcutaneous tissue. In those nodules, there were numerous, small, concentric proliferations of myoid-appearing spindle cells around small vascular lumina. The present case is an unusual example of myopericytoma, manifesting in a characteristic anastomosing, multinodular, infiltrating fashion. © 2015 Japanese Dermatological Association.

ESR, SIMS and TEMF of an Y-Ba-Cu-O superconductor

NASA Technical Reports Server (NTRS)

Kirschner, I.; Giber, J.; Halasz, I.

1995-01-01

Superconducting transition comes into being between 92 K and 82 K in the samples having a Meissner's state value of 68 vol. percent. The main material content has an orthorhombic unit cell of Y1Ba2Cu408 accompanied by low quantity CuO and a sporadic phase. A proof of anisotropic superconductivity, an unusually high Cu ion concentration and a temperature dependent transition of charge carriers have been observed.

Limnonectins: a new class of antimicrobial peptides from the skin secretion of the Fujian large-headed frog (Limnonectes fujianensis).

PubMed

Wu, Youjia; Wang, Lei; Zhou, Mei; Ma, Chengbang; Chen, Xiaole; Bai, Bing; Chen, Tianbao; Shaw, Chris

2011-06-01

Amphibian skin secretions are rich sources of biologically-active peptides with antimicrobial peptides predominating in many species. Several studies involving molecular cloning of biosynthetic precursor-encoding cDNAs from skin or skin secretions have revealed that these exhibit highly-conserved domain architectures with an unusually high degree of conserved nucleotide and resultant amino acid sequences within the signal peptides. This high degree of nucleotide sequence conservation has permitted the design of primers complementary to such sites facilitating "shotgun" cloning of skin or skin secretion-derived cDNA libraries from hitherto unstudied species. Here we have used such an approach using a skin secretion-derived cDNA library from an unstudied species of Chinese frog - the Fujian large-headed frog, Limnonectes fujianensis - and have discovered two 16-mer peptides of novel primary structures, named limnonectin-1Fa (SFPFFPPGICKRLKRC) and limnonectin-1Fb (SFHVFPPWMCKSLKKC), that represent the prototypes of a new class of amphibian skin antimicrobial peptide. Unusually these limnonectins display activity only against a Gram-negative bacterium (MICs of 35 and 70 μM) and are devoid of haemolytic activity at concentrations up to 160 μM. Thus the "shotgun" cloning approach described can exploit the unusually high degree of nucleotide conservation in signal peptide-encoding domains of amphibian defensive skin secretion peptide precursor-encoding cDNAs to rapidly expedite the discovery of novel and functional defensive peptides in a manner that circumvents specimen sacrifice without compromising robustness of data. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

Comparison of the distribution of large magmatic centers on Earth, Venus, and Mars

NASA Technical Reports Server (NTRS)

Crumpler, L. S.

1993-01-01

Volcanism is widely distributed over the surfaces of the major terrestrial planets: Venus, Earth, and Mars. Anomalous centers of magmatic activity occur on each planet and are characterized by evidence for unusual concentrations of volcanic centers, long-lived activity, unusual rates of effusion, extreme size of volcanic complexes, compositionally unusual magmatism, and evidence for complex geological development. The purpose of this study is to compare the characteristics and distribution of these magmatic anomalies on Earth, Venus, and Mars in order to assess these characteristics as they may relate to global characteristics and evolution of the terrestrial planets.

Liquid Structure with Nano-Heterogeneity Promotes Cationic Transport in Concentrated Electrolytes.

PubMed

Borodin, Oleg; Suo, Liumin; Gobet, Mallory; Ren, Xiaoming; Wang, Fei; Faraone, Antonio; Peng, Jing; Olguin, Marco; Schroeder, Marshall; Ding, Michael S; Gobrogge, Eric; von Wald Cresce, Arthur; Munoz, Stephen; Dura, Joseph A; Greenbaum, Steve; Wang, Chunsheng; Xu, Kang

2017-10-24

Using molecular dynamics simulations, small-angle neutron scattering, and a variety of spectroscopic techniques, we evaluated the ion solvation and transport behaviors in aqueous electrolytes containing bis(trifluoromethanesulfonyl)imide. We discovered that, at high salt concentrations (from 10 to 21 mol/kg), a disproportion of cation solvation occurs, leading to a liquid structure of heterogeneous domains with a characteristic length scale of 1 to 2 nm. This unusual nano-heterogeneity effectively decouples cations from the Coulombic traps of anions and provides a 3D percolating lithium-water network, via which 40% of the lithium cations are liberated for fast ion transport even in concentration ranges traditionally considered too viscous. Due to such percolation networks, superconcentrated aqueous electrolytes are characterized by a high lithium-transference number (0.73), which is key to supporting an assortment of battery chemistries at high rate. The in-depth understanding of this transport mechanism establishes guiding principles to the tailored design of future superconcentrated electrolyte systems.

Anatomical Analysis of Saccharomyces cerevisiae Stalk-Like Structures Reveals Spatial Organization and Cell Specialization

PubMed Central

Scherz, Ruth; Shinder, Vera; Engelberg, David

2001-01-01

Recently we reported an unusual multicellular organization in yeast that we termed stalk-like structures. These structures are tall (0.5 to 3 cm long) and narrow (1 to 3 mm in diameter). They are formed in response to UV radiation of cultures spread on high agar concentrations. Here we present an anatomical analysis of the stalks. Microscopic inspection of cross sections taken from stalks revealed that stalks are composed of an inner core in which cells are dense and vital and a layer of cells (four to six rows) that surrounds the core. This outer layer is physically separated from the core and contains many dead cells. The outer layer may form a protective shell for the core cells. Through electron microscopy analysis we observed three types of cells within the stalk population: (i) cells containing many unusual vesicles, which might be undergoing some kind of cell death; (ii) cells containing spores (usually one or two spores only); and (iii) familiar rounded cells. We suggest that stalk cells are not only spatially organized but may undergo processes that induce a certain degree of cell specialization. We also show that high agar concentration alone, although not sufficient to induce stalk formation, induces dramatic changes in a colony's morphology. Most striking among the agar effects is the induction of growth into the agar, forming peg-like structures. Colonies grown on 4% agar or higher are reminiscent of stalks in some aspects. The agar concentration effects are mediated in part by the Ras pathway and are related to the invasive-growth phenomenon. PMID:11514526

The geochemistry of uranium and thorium isotopes in the Western Desert of Egypt

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dabous, A.A.

1994-11-01

The concentrations of {sup 238}U, {sup 234}U, {sup 232}Th, and {sup 228}Th have been measured in the groundwaters of the Bahariya and Farafra oases of the Western Desert of Egypt. These waters are characterized by normal amounts of U, but unusually high concentrations of Th. The pattern of variation of the parent isotopes, {sup 238}U and {sup 232}Th, as well as the daughter isotopes, {sup 234}U, {sup 230}Th, and {sup 228}Th, is systematic within and between the two oases. From the unusually consistent distribution of the {sup 234}U/{sup 238}U activity ratios one can conclude that the samples from both oasesmore » are representative of a two-component mixing system. One component, characterized by low U content and a high {sup 234}U/{sup 238}U activity ratio, is typical of deep artesian systems and probably represents flowthrough water derived from the Nubian highlands to the south. The second component is characterized by a greater U concentration and a low activity ratio. This signature is hypothesized as being derived by leaching of downward infiltrating water during pluvial times. The source of the U may be the uraniferous phosphate strata that overly the sandstone aquifer in both oasis areas. Higher Th values are associated with the artesian flow component of the mixing system and suggests that Th-bearing minerals may be abundant in the Nubian sandstone aquifer. The distribution of {sup 230}Th and {sup 228}Th in the water samples supports this interpretation.« less

Antioxidants and Autism: Teachers' Perceptions of Behavioral Changes.

PubMed

Sadek, Amy; Berk, Lee S; Mainess, Karen; Daher, Noha S

2018-06-05

BACKGROUND- Children with Autism Spectrum Disorder (ASD) demonstrate a physiological imbalance between free radicals, resultant from oxidative stress, and antioxidants. Oxidative stress is linked to the pathogenesis of this neurocognitive disorder. The aim of this pilot feasibility study was to examine the effect of consumption of high concentration antioxidant cacao on behavior of children with ASD. METHODS- This was a 4-week pre-test post-test experimental pilot study of high antioxidant cacao and children with ASD. Participants consumed 8 squares (or 16 grams) per day of the dark chocolate which had a concentration of 70% cacao and 30% organic cane sugar (total antioxidant concentration was 8,320). The two main behavioral measures were the Aberrant Behavior Checklist- 2nd Edition and the Autism Spectrum Rating Scale which were completed by the child's teacher at baseline and end of week four. RESULTS- Sixteen participants were recruited for this study. Follow up data was available on 12 participants (9 males, 3 females, mean age of 10.9 ±3.9 years). Significant improvements on the Autism Spectrum Rating Scale were noted in Social/Communication (p=0.03, η2=0.79), Unusual Behaviors (p=0.02, η2=0.70), and Self-Regulation (p=0.04, η2=0.59). No significant changes were noted on any of the Aberrant Behavior Checklist-2 subscales (p>.05). CONCLUSION- Results from this study support the potential therapeutic benefit of antioxidants in improving social communication, unusual behaviors, and self-regulation behaviors of children with ASD. Further robust randomized controlled trials are now necessary to elaborate the validity of these findings.

Unusual effects of penicillin G and chloramphenicol on the growth of Moraxella osloensis.

PubMed

DeLeys, R J; Juni, E

1977-11-01

Growth of exponential-phase liquid cultures of Moraxella osloensis was inhibited by 0.5 U of penicillin G per ml. For this organism, low concentrations of penicillin acted primarily in a bacteriostatic rather than in a bactericidal manner. At higher concentrations of penicillin some killing did take place, but the rate of killing was rather slow and appeared to be independent of penicillin concentration. Microscopic observation of cells from penicillin-treated cultures showed little or no cellular swelling or lysis. The total cell count did not decrease significantly during 6 h of incubation in 5,000 U of penicillin per ml. The rates of respiration, nucleic acid synthesis, and protein synthesis were not affected by the presence of penicillin. Attempts to counteract the bactericidal action of high concentrations of penicillin with growth inhibitory concentrations of chloramphenicol were unsuccessful, since chloramphenicol itself was more bactericidal than penicillin for M. osloensis.

Unusual Effects of Penicillin G and Chloramphenicol on the Growth of Moraxella osloensis

PubMed Central

DeLeys, Robert J.; Juni, Elliot

1977-01-01

Growth of exponential-phase liquid cultures of Moraxella osloensis was inhibited by 0.5 U of penicillin G per ml. For this organism, low concentrations of penicillin acted primarily in a bacteriostatic rather than in a bactericidal manner. At higher concentrations of penicillin some killing did take place, but the rate of killing was rather slow and appeared to be independent of penicillin concentration. Microscopic observation of cells from penicillin-treated cultures showed little or no cellular swelling or lysis. The total cell count did not decrease significantly during 6 h of incubation in 5,000 U of penicillin per ml. The rates of respiration, nucleic acid synthesis, and protein synthesis were not affected by the presence of penicillin. Attempts to counteract the bactericidal action of high concentrations of penicillin with growth inhibitory concentrations of chloramphenicol were unsuccessful, since chloramphenicol itself was more bactericidal than penicillin for M. osloensis. PMID:335964

Morphine, Endogenous Opioid Peptides, and Reproduction in the Male Rhesus Monkey

DTIC Science & Technology

1983-05-18

receptors are both antagonized at high dose levels, while at low doses , naloxone antagonizes only u-receptors (Kosterlitz, 1980). Studies of a...found witli the 20 ug/kg dose . As in the case of testosterone at the same dose , the LH pretreatment levels measured were unusually low (600 ng/dl vs...concentration of the dose of an- tagonist required to reduce agonistic potency by one-half. Due to differences in affinity, naloxone at low dose levels

Human contribution to the European heatwave of 2003

NASA Astrophysics Data System (ADS)

Stott, Peter A.; Stone, D. A.; Allen, M. R.

2004-12-01

The summer of 2003 was probably the hottest in Europe since at latest AD 1500, and unusually large numbers of heat-related deaths were reported in France, Germany and Italy. It is an ill-posed question whether the 2003 heatwave was caused, in a simple deterministic sense, by a modification of the external influences on climate-for example, increasing concentrations of greenhouse gases in the atmosphere-because almost any such weather event might have occurred by chance in an unmodified climate. However, it is possible to estimate by how much human activities may have increased the risk of the occurrence of such a heatwave. Here we use this conceptual framework to estimate the contribution of human-induced increases in atmospheric concentrations of greenhouse gases and other pollutants to the risk of the occurrence of unusually high mean summer temperatures throughout a large region of continental Europe. Using a threshold for mean summer temperature that was exceeded in 2003, but in no other year since the start of the instrumental record in 1851, we estimate it is very likely (confidence level >90%) that human influence has at least doubled the risk of a heatwave exceeding this threshold magnitude.

The unusual amino acid l-ergothioneine is a physiologic cytoprotectant

PubMed Central

Paul, BD; Snyder, SH

2010-01-01

Ergothioneine (ET) is an unusual sulfur-containing derivative of the amino acid, histidine, which is derived exclusively through the diet. Although ET was isolated a century ago, its physiologic function has not been clearly established. Recently, a highly specific transporter for ET (ETT) was identified in mammalian tissues, which explains abundant tissue levels of ET and implies a physiologic role. Using RNA interference, we depleted cells of its transporter. Cells lacking ETT are more susceptible to oxidative stress, resulting in increased mitochondrial DNA damage, protein oxidation and lipid peroxidation. ETT is concentrated in mitochondria, suggesting a specific role in protecting mitochondrial components such as DNA from oxidative damage associated with mitochondrial generation of superoxide. In combating cytotoxic effects of pyrogallol, a known superoxide generator, ET is as potent as glutathione. Because of its dietary origin and the toxicity associated with its depletion, ET may represent a new vitamin whose physiologic roles include antioxidant cytoprotection. PMID:19911007

Hingganite-(Y) from a small aplite vein in granodiorite from Oppach, Lusatian Mts., E-Germany

NASA Astrophysics Data System (ADS)

Thomas, Rainer; Davidson, Paul

2017-12-01

Crystals of hingganite-(Y) occur co-trapped in quartz crystals from miarolitic cavities in an aplite vein in the Cadomian granodiorite from Oppach/Lusatian, Germany. We describe the chemical composition and provide a reference Raman spectrum of this mineral, for which little useful spectral data has been published. In addition, we provide some inferences as to the genesis of this mineral in relationship to melt and fluid inclusions in quartz. The paragenetic sequence of minerals conserved only as small crystal inclusions in quartz, demonstrates an unusual occurrence in the Lusatian aplites, characterized by an unusual, extremely water-rich, near-supercritical melt-fluid system with high concentrations in alkali carbonates and sulfates. We propose that a sulfate-rich system was responsible for the fixation of Be and REE as hingganite-(Y), rather than the more common beryl + REE mineral assemblage. This may provide an explanation for the formation of this otherwise rare mineral

Seizure Suppression by High Temperature via cAMP Modulation in Drosophila.

PubMed

Saras, Arunesh; Tanouye, Mark A

2016-10-13

Bang-sensitive (BS) Drosophila mutants display characteristic seizure-like activity (SLA) and paralysis after mechanical shock . After high-frequency electrical stimulation (HFS) of the brain, they generate robust seizures at very low threshold voltage. Here we report an important phenomenon, which effectively suppresses SLA in BS mutants. High temperature causes seizure suppression in all BS mutants (para bss1 , eas, sda) examined in this study. This effect is fully reversible and flies show complete recovery from BS paralysis once the temperature effect is nullified. High temperature induces an increase in seizure threshold after a brief pulse of heat shock (HS). By genetic screening, we identified the involvement of cAMP in the suppression of seizures by high temperature. We propose that HS induces adenylyl cyclase which in turn increases cAMP concentration which eventually suppresses seizures in mutant flies. In summary, we describe an unusual phenomenon, where high temperature can suppress SLA in flies by modulating cAMP concentration. Copyright © 2016 Saras and Tanouye.

Harmful Algal Bloom Hotspots Really Are Hot: A Case Study from Monterey Bay, California

NASA Astrophysics Data System (ADS)

Kudela, R. M.; Anderson, C.; Birch, J. M.; Bowers, H.; Caron, D. A.; Chao, Y.; Doucette, G.; Farrara, J. D.; Gellene, A. G.; Negrey, K.; Howard, M. D.; Ryan, J. P.; Scholin, C. A.; Smith, J.; Sukhatme, G.

2015-12-01

Monterey Bay, California is one of several recognized hotspots for harmful algal blooms along the US west coast, particularly for the toxigenic diatom Pseudo-nitzschia, which produces domoic acid and is responsible for Amnesic Shellfish Poisoning. Historical observations have linked bloom activity to anomalously warm conditions with weak and sporadic upwelling. In particular, blooms appear to be associated with El Niño conditions. Monterey, as with much of the US west coast, experienced unusual warm conditions in spring and summer 2014, leading to multiple ecosystem effects including massive algal blooms, concentration of apex predators nearshore, and unusually high levels of domoic acid. As the warm anomalies continued and strengthened into 2015, Monterey (and much of the west coast) has been experiencing the largest and most toxic algal bloom recorded in the last 15 years, as well as unprecedented coccolithophore blooms associated with warm, nutrient-depleted waters. With the strengthening El Niño conditions developing in summer 2015, it is possible that 2016 will result in a third consecutive year of unusually toxic algal blooms. Using a combination of historical observations, intensive field studies, and predictive models we explore the hypothesis that these warm anomalies lead to shifts in the typical upwelling-dominated food web leading to a collapse of the ecosystem towards the coast, unusual algal blooms, and enhanced trophic transfer of toxins, resulting in magnified negative impacts to wildlife and, potentially, humans.

49 CFR 236.1021 - Discontinuances, material modifications, and amendments.

Code of Federal Regulations, 2011 CFR

2011-10-01

... such as landslide, burned bridge, high water, high and wide load, or tunnel protection when the unusual... to provide protection against unusual contingencies such as landslide, burned bridges, high water...

49 CFR 236.1021 - Discontinuances, material modifications, and amendments.

Code of Federal Regulations, 2010 CFR

2010-10-01

... such as landslide, burned bridge, high water, high and wide load, or tunnel protection when the unusual... to provide protection against unusual contingencies such as landslide, burned bridges, high water...

49 CFR 235.7 - Changes not requiring filing of application.

Code of Federal Regulations, 2013 CFR

2013-10-01

... unusual contingencies such as landslide, burned bridge, high water, high and wide load, or tunnel... used to provide protection against unusual contingencies such as landslide, burned bridges, high water...

49 CFR 235.7 - Changes not requiring filing of application.

Code of Federal Regulations, 2014 CFR

2014-10-01

... unusual contingencies such as landslide, burned bridge, high water, high and wide load, or tunnel... used to provide protection against unusual contingencies such as landslide, burned bridges, high water...

49 CFR 236.1021 - Discontinuances, material modifications, and amendments.

Code of Federal Regulations, 2013 CFR

2013-10-01

... such as landslide, burned bridge, high water, high and wide load, or tunnel protection when the unusual... to provide protection against unusual contingencies such as landslide, burned bridges, high water...

49 CFR 236.1021 - Discontinuances, material modifications, and amendments.

Code of Federal Regulations, 2014 CFR

2014-10-01

... such as landslide, burned bridge, high water, high and wide load, or tunnel protection when the unusual... to provide protection against unusual contingencies such as landslide, burned bridges, high water...

49 CFR 235.7 - Changes not requiring filing of application.

Code of Federal Regulations, 2012 CFR

2012-10-01

... unusual contingencies such as landslide, burned bridge, high water, high and wide load, or tunnel... used to provide protection against unusual contingencies such as landslide, burned bridges, high water...

49 CFR 236.1021 - Discontinuances, material modifications, and amendments.

Code of Federal Regulations, 2012 CFR

2012-10-01

... such as landslide, burned bridge, high water, high and wide load, or tunnel protection when the unusual... to provide protection against unusual contingencies such as landslide, burned bridges, high water...

Unusual Characteristics of the DNA Binding Domain of Epigenetic Regulatory Protein MeCP2 Determine Its Binding Specificity

PubMed Central

2015-01-01

The protein MeCP2 mediates epigenetic regulation by binding methyl-CpG (mCpG) sites on chromatin. MeCP2 consists of six domains of which one, the methyl binding domain (MBD), binds mCpG sites in duplex DNA. We show that solution conditions with physiological or greater salt concentrations or the presence of nonspecific competitor DNA is necessary for the MBD to discriminate mCpG from CpG with high specificity. The specificity for mCpG over CpG is >100-fold under these solution conditions. In contrast, the MBD does not discriminate hydroxymethyl-CpG from CpG. The MBD is unusual among site-specific DNA binding proteins in that (i) specificity is not conferred by the enhanced affinity for the specific site but rather by suppression of its affinity for generic DNA, (ii) its specific binding to mCpG is highly electrostatic, and (iii) it takes up as well as displaces monovalent cations upon DNA binding. The MBD displays an unusually high affinity for single-stranded DNA independent of modification or sequence. In addition, the MBD forms a discrete dimer on DNA via a noncooperative binding pathway. Because the affinity of the second monomer is 1 order of magnitude greater than that of nonspecific binding, the MBD dimer is a unique molecular complex. The significance of these results in the context of neuronal function and development and MeCP2-related developmental disorders such as Rett syndrome is discussed. PMID:24828757

Preparation of polydopamine nanocapsules in a miscible tetrahydrofuran-buffer mixture.

PubMed

Ni, Yun-Zhou; Jiang, Wen-Feng; Tong, Gang-Sheng; Chen, Jian-Xin; Wang, Jie; Li, Hui-Mei; Yu, Chun-Yang; Huang, Xiao-hua; Zhou, Yong-Feng

2015-01-21

A miscible tetrahydrofuran-tris buffer mixture has been used to fabricate polydopamine hollow capsules with a size of 200 nm and with a shell thickness of 40 nm. An unusual non-emulsion soft template mechanism has been disclosed to explain the formation of capsules. The results indicate that the capsule structure is highly dependent on the volume fraction of tetrahydrofuran as well as the solvent, and the shell thickness of capsules can be controlled by adjusting the reaction time and dopamine concentration.

The Anomalous Magnetoresistance of Graphite at High Magnetic Fields,

DTIC Science & Technology

1983-05-01

magnetoresistance anomaly. In the present work, the unusual properties of this fine structure (which is periodic in magnetic field H ) is examined in more detail...structure associated with the magnetoresistance anomly is (AH/ H ) - 0.1 T/25 T or about 0.4 Z. Thus, for typical magnetic field sweep rates (10 T in 10...magnetoresistance above 12 T have been associated by lye at al.2 with a linear increase in carrier concentration with increasing H .1 The anomalous increase

On the observation of the need for an unusually high concentration of cysteine and homocysteine to induce aggregation of polymer-stabilized gold nano particles

NASA Astrophysics Data System (ADS)

Radhakumary, C.; Sreenivasan, K.

2013-02-01

This study reports the interaction of chitosan-stabilized gold nanoparticles (CH-AuNPs) with cysteine (Cys) and homocysteine (Hcys) in aqueous media at pH 1.4. Since the polymer precipitates at higher pH, and the amino acids Cys and HCys are soluble at acidic pH, we kept the pH around 1.4 for stabilizing the particles. Zeta potential of CH-AuNPs was found to be positive and it is reasonable to assume that +ve Cys or Hcys at pH 1.4 will experience repulsive force. However, TEM images and absorption spectra indicated formation of aggregates including rod-like assembly. An interesting observation was the need for unusually high concentration of analytes (Cys and Hcys) to induce the assembly of CH-AuNPs. We also found time bound variation of the optical properties probably indicating the interaction is kinetically controlled and only a fraction of the analyte molecules having sufficient energy can bind onto the particles. We observed that at elevated temperature, the reaction was faster with a lower concentration of Cys or Hcys. These observations were supported by the classical Derjaguin-Landau-Verwey-Overbeek (DLVO) theory which describes the interparticle interaction and the colloidal stability in solution. Only molecules possessing enough energy to cross this force barrier can cause the aggregation. We also noted a time lag between Cys and Hcys to influence optical properties reflecting the possibility of using this simple approach to discriminate these two clinically relevant molecules. Our observation shows that simple sensing as well as generation of novel nanostructures could be manipulated by a judicious choice of conditions such as stabilizing agents, pH, etc.

Gold and other metals in big sagebrush (Artemisia tridentata Nutt.) as an exploration tool, Gold Run District, Humboldt County, Nevada

USGS Publications Warehouse

Erdman, J.A.; Cookro, T.M.; O'Leary, R. M.; Harms, T.F.

1988-01-01

Big sagebrush - a cold-desert species that dominates the terrain over large parts of western United States - was sampled along several traverses that crossed thermally metamorphosed limestone, phyllitic shale, and schist of the Middle and Upper Cambrian Preble Formation that host skarn-, disseminated gold and silver-, and hot springs gold-type mineral occurrences. Patterns of detectable levels of gold (8 to 28 ppb or ng g-1) in ash of new growth were consistent with areas affected by known or suspected gold mineralization. Soils collected along one of the traverses where a selenium-indicator plant was common contained no gold above background levels of 2ppb, but were consistently high in As, Sb, and Zn, and several samples were unusually high in Se (maximum 11 ppm or ??g g-1). Sagebrush along this traverse contained Li at levels above norms for this species. We also found a puzzling geochemical anomaly at a site basinward from active hot springs along a range-front fault scarp. Sagebrush at this site contained a trace of gold and an unusually high concentration of Cd (13 ppm) and the soil had anomalous concentrations of Cd and Bi (3.2 and 6 ppm, respectively). The source of this anomaly could be either metal-rich waters from an irrigation ditch or leakage along a buried fault. Despite the limited nature of the study, we conclude that gold in sagebrush could be a cost-effective guide to drilling locations in areas where the geology seems favorable for disseminated and vein precious metals. ?? 1988.

Unusually high (210)Po activities in the surface water of the Zhubi Coral Reef Lagoon in the South China Sea.

PubMed

Yang, Weifeng; Huang, Yipu; Chen, Min; Qiu, Yusheng; Li, Hongbin; Zhang, Lei

2011-10-01

Recent researches revealed the exciting application of (210)Po in tracing carbon and nitrogen cycling in the coral reef system. In order to quantify the recycling of particulate organic nitrogen (PON), both (210)Po and (210)Pb were examined at both high and low tides in the Zhubi Coral Reef lagoon, the South China Sea. Unusually, much higher (210)Po activities and (210)Po/(210)Pb ratios, in comparison with those found in the open seawater and the lagoon subsurface water, showed additional input of (210)Po besides production from in situ(210)Pb in the lagoon surface water. Statistical analysis identified that the reef flat seawater was the additional (210)Po source. Based on a mass balance model, the input rates of (210)Po varied from 0.04 Bq m(-3)year(-1) to 8.41 Bq m(-3)year(-1). On average, the additional (210)Po contributed more than 60% of the total (210)Po. The particulate (210)Po significantly correlated with the concentrations of PON, indicating that diffusion of (210)Po from sediment could be used to quantify the recycling of nitrogen. The average input rate of nitrogen was 16 mmol m(-3)year(-1), which can support up to 11% of the primary production rate. These results suggested that the unusual behavior of (210)Po could provide new insight into the nitrogen recycling in the coral reef system. Copyright © 2011 Elsevier B.V. All rights reserved.

Reproduction and organochlorine contaminants in terns at San Diego Bay

USGS Publications Warehouse

Ohlendorf, H.M.; Schaffner, F.C.; Custer, T.W.; Stafford, C.J.

1985-01-01

In 1981, we studied Caspian Terns (Sterna caspia) and Elegant Terns (S. elegans) nesting at the south end of San Diego Bay, California. Randomly collected Caspian Tern eggs contained signficantly (P < 0.05) higher mean concentrations of DDE (9.30 ppm) than did Elegant Tern eggs (3.79 ppm). DDE may have had an adverse effect on Caspian Tern reproduction but the relationship between hatching success and DDE concentration was not clear. We found an unusually high incidence of chicks (4.6%) that died in hatching. Caspian Tern eggs that broke during incubation or contained chicks that died while hatching had shells that were significantly (P < 0.05) thinner than eggs collected before 1947, and DDE was associated with reductions in shell thickness index (i.e., lowered eggshell density). Fish brought to Caspian Tern chicks contained up to 3.0 ppm DDE and 1.1 ppm PCBs. Organochlorine concentration brains of terns found dead were not high enough to suggest such poisoning as a cause of death.

Multispectral In-situ Measurements of Organic Matter and Chlorophyll Fluorescence in Seawater: Documenting the Intrusion of the Mississippi River Plume in the West Florida Shelf

NASA Technical Reports Server (NTRS)

DelCastillo, Carlos E.; Coble, Paula G.; Conmy, Robyn N.; Mueller-Karger, Frank E.; Vanderbloomen, Lisa; Vargo, Gabriel A.

2000-01-01

We performed multispectral in-situ fluorescence measurement of colored dissolved organic matter and chlorophyll in surface water of the West Florida Shelf using West Labs Spectral absorption and Fluorescence Instrument (SAFIre). Continuous measurements underway allowed us to simultaneously map the dispersion of riverine organic material and chlorophyll on the shelf. By using two fluorescence emission ratios we were able to differentiate between riverine and marine CDOM. Our data also showed unusually high concentrations of CDOM offshore. These were attributed to an intrusion of the Mississippi River Plume. We performed limited comparisons between in-situ chlorophyll concentrations measured with SAFIre and chlorophyll values obtained from SeaWiFS satellite data using OC4 and MODIS algorithm. Our results show that, although both algorithms overestimated chlorophyll, MODIS performed better than OC4, particularly in areas with high CDOM concentrations. Analysis of the relationship between chlorophyll and CDOM concentrations within the study area showed regional variability causes by differences in river source.

Non-monotonic permeability variation during colloidal transport: Governing equations and analytical model

NASA Astrophysics Data System (ADS)

Chequer, L.; Russell, T.; Behr, A.; Genolet, L.; Kowollik, P.; Badalyan, A.; Zeinijahromi, A.; Bedrikovetsky, P.

2018-02-01

Permeability decline associated with the migration of natural reservoir fines impairs the well index of injection and production wells in aquifers and oilfields. In this study, we perform laboratory corefloods using aqueous solutions with different salinities in engineered rocks with different kaolinite content, yielding fines migration and permeability alteration. Unusual permeability growth has been observed at high salinities in rocks with low kaolinite concentrations. This has been attributed to permeability increase during particle detachment and re-attachment of already mobilised fines by electrostatic attraction to the rock in stagnant zones of the porous space. We refine the traditional model for fines migration by adding mathematical expressions for the particle re-attachment rate, particle detachment with delay relative to salinity decrease, and the attached-concentration-dependency of permeability. A one-dimensional flow problem that accounts for those three effects allows for an exact analytical solution. The modified model captures the observed effect of permeability increase at high water salinities in rocks with low kaolinite concentrations. The developed model matches the coreflooding data with high accuracy, and the obtained model coefficients vary within their usual intervals.

Modeling 13C discrimination in Tree Rings

NASA Astrophysics Data System (ADS)

Berninger, Frank; Sonninen, Eloni; Aalto, Tuula; Lloyd, Jon

2000-03-01

Annual variations from 1877 to 1995 in tree-ring α-cellulose 13C/12C isotopic ratios for four subarctic Pinus sylvestris trees were determined, and, in conjunction with a recent record of atmospheric 13CO2/12CO2 ratios, the historical pattern of photosynthetic isotope discrimination, Δ13C, was evaluated. Year-to-year variability in Δ13C has been as much as 1.5‰ with the period 1900-1920 showing an extended period of unusually high photosynthetic discriminations. The summers during these years were, on average, unusually cold. Since 1920 a long term trend of increasing Δ13C of ˜0.016‰yr-1 is inferred. We compared measured Δ13C with those predicted on the basis of the theoretical relationship between Δ13C and the ratio of substomatal to ambient CO2 concentration, Ci/Ca using mechanistic equations for chloroplast biochemistry coupled with a stomatal conductance model. Two variations of a nonlinear optimal-regulation stomatal conductance model were compared. Although both models were based on the assumption that stomata serve to minimize the average transpiration rate for a given average rate of CO2 assimilation, one version of the model incorporated reductions in stomatal conductance in response to recent increases in atmospheric CO2 concentrations and the other did not. The CO2 sensitive stomatal model failed to describe the long-term increase in 13C discrimination, especially after 1950. The insensitive model gave good agreement, suggesting that an observed increase in subarctic Pinus sylvestris Δ13C since 1920 is attributable to recent increases in atmospheric CO2 concentrations with subsequent increases in the ratio of substomatal to ambient CO2 concentrations. The model was also capable of accounting for high frequency (year-to-year) variations in Δ13C, these differences being attributable to year-to-year fluctuations in the average leaf-to-air vapor pressure difference affecting stomatal conductance and hence Ci/Ca.

Rabbitfish ("aras"): an unusual source of ciguatera poisoning.

PubMed

Raikhlin-Eisenkraft, Bianca; Bentur, Yedidia

2002-01-01

Ciguatera poisoning is the commonest fish-borne seafood intoxication. It is endemic to warm water tropical areas and is caused by consumption of bottom-dwelling shore reef fish, mostly during spring and summer. The causative agent, ciguatoxin, is a heat-stable ester complex that becomes concentrated in fish feeding on toxic dinoflagellates. The common clinical manifestations are a combination of gastrointestinal and neurologic symptoms. Severe poisoning may be associated with seizures and respiratory paralysis. To describe a series of patients who sustained ciguatera poisoning in an uncommon region and from an unexpected source. Two families complained of a sensation of "electrical currents," tremors, muscle cramps, nightmares, hallucinations, agitation, anxiety and nausea of varying severity several hours after consuming rabbitfish ("aras"). These symptoms lasted between 12 and 30 hours and resolved completely. The temporal relationship to a summer fish meal, the typical clinical manifestations along with the known feeding pattern of the rabbitfish suggested ciguatera poisoning. The Eastern Mediterranean basin is an unusual region and the rabbitfish an unusual source for ciguatera poisoning. There are no readily available and reliable means for detecting ciguatoxin in humans. A high index of suspicion is needed for diagnosis and a thorough differential diagnosis is essential to eliminate other poisonings, decompression sickness and encephalitis. Supportive therapy is the mainstay of treatment.

Atmospheric organochlorine pesticides in the western Canadian Arctic: Evidence of transpacific transport

NASA Astrophysics Data System (ADS)

Bailey, R.; Barrie, L. A.; Halsall, C. J.; Fellin, P.; Muir, D. C. G.

2000-05-01

Concentrations of hexachlorocyclohexanes (HCHs), chlordane, and dichlorodiphenyltrichloroethane (DDT) were measured in ambient air samples on a weekly basis between December 1992 and January 1995 at Tagish Yukon, Canada. In winter, unusually high air concentrations of HCHs, DDT, and chlordanes at Tagish were predominantly influenced by transpacific long-range atmospheric transport from eastern Asia that generally occurred within 5 days. HCH and heptachlor epoxide concentrations were correlated with the time that air spent over eastern Asia prior to arrival at Tagish. Chlordane and DDT, which also increase with transpacific transport, do not show a correlation with the time the upwind airshed included Asia as the composition of these pesticides in the atmosphere is affected by differences in usage patterns, application methods, variable composition of parent pesticides and metabolites in the soil, and rates of volatilization. Air masses originating from North America had the highest concentrations of HCHs and chlordanes when the 5-day upwind airshed included the western United States. Concentrations of HCHs may also be influenced by lindane usage in Canada.

Climate, ENSO and 'Black Swans' over the Last Millennium

NASA Astrophysics Data System (ADS)

Thompson, L. G.; Mosley-Thompson, E.; Davis, M. E.; Kenny, D. V.; Lin, P. N.

2014-12-01

Tropical rainfall patterns influence the lives of billions of people both north and south of the Equator. Evidence of major ENSO events such as droughts is often recorded in the oxygen isotopic ratios and aerosol concentrations in tropical ice cores. Here we examine unusual events recorded in three ice cores, two (Quelccaya and Coropuna) in the Southern Hemisphere on the Peruvian Altiplano and the third (Dasuopu) located 22,000 km away on the southern edge of the Tibetan Plateau at the top of the Himalayas. These records suggest that the unique lower and middle tropospheric air flow over chloride (Cl-) and fluoride (F-) enriched areas upwind of the sites during ENSO events leads to enhanced deposition of these species on these glaciers. Linkages are demonstrated between ice-core chemistry and drought indicators, changes in lake levels, and ENSO and monsoon indices. Two unusual events, in the late 18th and mid-14th Centuries, are marked by abnormally high concentrations of F- and Cl- in at least two of the ice core records. All three records document a drought from 1789 to 1800 CE in which increases in these anionic concentrations reflect the abundance of continental atmospheric dust derived from arid regions upwind of the core sites. The earlier event, apparent only in the Quelccaya and Dasuopu ice cores, begins abruptly in 1343 and tapers off by 1375. The interaction between high frequency El Niños and low frequency shifts in the inter-tropical convergence zone may have resulted in these unusually severe and extended droughts. These "Black Swan" events correspond to historically documented, devastating population disruptions that were in part climate related. The 1789 to 1800 CE event was concurrent with the Doji Bara famine resulting from extended droughts that led to over 600,000 deaths in central India by 1792. Similarly extensive climate disruptions are documented in Central and South America. The mid-14th Century drought is concomitant with major monsoon failures in India, collapse of the Yang Dynasty in China, and the "Black Death" pandemic that eliminated roughly 30% of the global population. Understanding the characteristics and drivers of these historical events is critical for design of adaptive measures for a world with over seven billion people and unprecedented anthropogenic influences on the climate.

Mercury speciation and microbial transformations in mine wastes, stream sediments, and surface waters at the Almaden Mining District, Spain

USGS Publications Warehouse

Gray, John E.; Hines, Mark E.; Higueras, Pablo L.; Adatto, Isaac; Lasorsa, Brenda K.

2004-01-01

Speciation of Hg and conversion to methyl-Hg were evaluated in mine wastes, sediments, and water collected from the Almade??n District, Spain, the world's largest Hg producing region. Our data for methyl-Hg, a neurotoxin hazardous to humans, are the first reported for sediment and water from the Almade??n area. Concentrations of Hg and methyl-Hg in mine waste, sediment, and water from Almade??n are among the highest found at Hg mines worldwide. Mine wastes from Almade??n contain highly elevated Hg concentrations, ranging from 160 to 34 000 ??g/g, and methyl-Hg varies from <0.20 to 3100 ng/g. Isotopic tracer methods indicate that mine wastes at one site (Almadenejos) exhibit unusually high rates of Hg-methylation, which correspond with mine wastes containing the highest methyl-Hg concentrations. Streamwater collected near the Almade??n mine is also contaminated, containing Hg as high as 13 000 ng/L and methyl-Hg as high as 30 ng/L; corresponding stream sediments contain Hg concentrations as high as 2300 ??g/g and methyl-Hg concentrations as high as 82 ng/g. Several streamwaters contain Hg concentrations in excess of the 1000 ng/L World Health Organization (WHO) drinking water standard. Methyl-Hg formation and degradation was rapid in mines wastes and stream sediments demonstrating the dynamic nature of Hg cycling. These data indicate substantial downstream transport of Hg from the Almade??n mine and significant conversion to methyl-Hg in the surface environment.

Detergent effects on enzyme activity and solubilization of lipid bilayer membranes.

PubMed

Womack, M D; Kendall, D A; MacDonald, R C

1983-09-07

Over 50 detergents were tested to establish which would be most effective in releasing proteins from membrane-bounded compartments without denaturing them. Various concentrations each of detergent were tested for two activities: (1) solubilization of egg phospholipid liposomes as measured by reduction of turbidity and (2) effect of detergent concentration on the activities of soluble, hydrolytic enzymes. Those detergents most effective in solubilizing 0.2% lipid and least detrimental to enzymes were five pure, synthetic compounds recently introduced: CHAPS, CHAPSO, Zwittergents 310 and 312, and octylglucoside. Industrial detergents were generally much inferior, insofar as they solubilized membranes inefficiently and/or inactivated certain hydrolytic enzymes readily. The five detergents were characterized by (a) an unusually high critical micelle concentration and (b) a preference for forming mixed micelles with lipids instead of forming pure micelles, as indicated by an ability to solubilize lipid at concentrations of detergent significantly below the critical micelle concentration. This characteristic permits solubilization of high concentrations of membrane below the critical micelle concentration of the detergent so that protein denaturation is minimized. A generally applicable guideline that emerged from this study is that detergents should be used at approximately their critical micelle concentration which should not be exceeded by the concentration of membrane. Similar considerations should apply to the use of detergents in purifying and reconstituting intrinsic membrane proteins.

Doping mechanism of antinomy in PbWO4

NASA Astrophysics Data System (ADS)

Li, Wensheng; Tang, Tong B.; Feng, Xiqi

2002-01-01

Sb doped PbWO4 (Sb:PWO) shows unique features in its dielectric and visible spectra. We propose that, in low concentration, the dopant enters the lattice as interstitial ions, and at high level it also substitute for W6+ sties. The existence of interstitial ions with relatively high mobility leads to non-negligible dc conductivity, whereas the substitutional impurity produces O23- color centers, which results in absorption at 420 nm, as well as holes hopping among oxygen ions in the Sb-O tetrahedra, that is the origin for the observed dielectric relaxation with an unusually low activation energy of 30±2 meV.

Direct Observation of Optical Field Phase Carving in the Vicinity of Plasmonic Metasurfaces.

PubMed

Dagens, B; Février, M; Gogol, P; Blaize, S; Apuzzo, A; Magno, G; Mégy, R; Lerondel, G

2016-07-13

Plasmonic surfaces are mainly used for their optical intensity concentration properties that allow for enhancement of physical interaction like in nonlinear optics, optical sensors, or tweezers. Phase response in plasmonic resonances can also play a major role, especially in a periodic assembly of plasmonic resonators like metasurfaces. Here we show that localized surface plasmons collectively excited by a guided mode in a metallic nanostructure periodic chain present nonmonotonous phase variation along the 1D metasurface, resulting from both selective Bloch mode coupling and dipolar coupling. As shown by near-field measurements, the phase profile of the highly concentrated optical field is carved out in the vicinity of the metallic metasurface, paving the way to unusual local optical functions.

Spuriously high androstendione concentrations due to assay interference as a cause of diagnostic conundrum in women with oligomenorrhoea.

PubMed

Lewandowski, Krzysztof C; Grotowski, Waldemar; Dabrowska, Katarzyna; Głowacka, Ewa; Lewiński, Andrzej

2015-03-01

Polycystic ovary syndrome (PCOS) is a diagnosis of exclusion. We present two cases of women with oligomenorrhoea and high concentration of androstendione, suggestive of possible androgen-secreting tumour; caused by assay interference. The first patient, investigated for oligomenorrhoea, had no significant hirsutism or acne. Androstendione concentration was above 10.0 ng/ml (rr: 0.3-3.3 ng/ml). In order to rule out possible androgen-secreting tumour or hypercortisolaemia we performed 48-hour low dose dexamethasone suppression test (LDDST). This failed to demonstrate adequate suppression of androstendione (6.05 ng/ml and 9.32 ng/ml after the first and the second day respectively). Pelvic ultrasound examination showed polycystic ovaries, while abdominal CTscan failed to show any ovarian or adrenal lesion. Despite such high androstendione concentrations, urinary steroid profile (gas chromatography/mass spectrometry method) yielded normal results. Hence a possibility of androstendione assay interference was raised. The second patient was also admitted for investigations of oligomenorrhoea. Clinical examination was unremarkable. There was a high concentration of testosterone 0.78 ng/ml (rr. 0.084-0.481 ng/ml) and androstendione above 10.0 ng/ml (rr: 0.3-3.3 ng/ml). LDDST failed to demonstrate any suppression of androstendione, while recalculated concentrations of androstendione after serial dilutions were markedly lower in comparison to initial values. Therefore, such high androstendione concentrations (i.e. above the upper limit of the assay) must have resulted from assay interference. In both cases a final diagnosis of PCOS was established. In the absence of clinical features, contrasting with unusually high androgen levels, a possibility of androgen assay interference should be considered in differential diagnosis of hyperandrogenism or PCOS.

The effect of the osmolality of sugar-containing media, the type of sugar, and the mass and molar concentration of sugar on the survival of frozen-thawed mouse sperm.

PubMed

Koshimoto, Chihiro; Mazur, Peter

2002-08-01

Several factors have contributed to problems in mouse sperm cryopreservation, and we and others have found ways to ameliorate them. These include high sensitivity to several types of mechanical stresses and to oxygen-derived free radicals, low tolerance to osmotic cell volume changes, and rather rigorous requirements for cooling and warming rates. Another important factor is the cryoprotective agent. Mouse sperm are unusual in that our best results have been obtained in media containing the nonpermeating sugar raffinose (18% w/v) and lacking glycerol. This paper deals with questions about the basis of the protective action of sugars, and whether raffinose is unusual or unique in its ability to confer protection. More specifically, we investigated whether protection was more related to the total osmolality of the freezing solution, to the mass concentration of sugar, or to the molarity of the sugar, and we looked to see whether there are effects attributable to specific sugars. To investigate these questions, mouse sperm were frozen at the optimal rate of 25 degrees C/min in solutions prepared with different proportions of three sugars-raffinose, sucrose, and glucose-dissolved in 1/4x PBS. In the first experimental series, the total osmolality and the total sugar molarity were varied from 400 to 700 mOsm and from 300 to 530 mM, respectively, while holding the mass concentration of sugar constant at 18% (w/v). In the second experimental series, the mass concentration of sugars was varied from 10 to 18% while the sugar molarity and solution osmolality remained constant at 300 mM and 420 mOsm, respectively. The results suggest that protection against freezing and thawing depends more on the mass concentration of the sugar than on its molar concentration, a conclusion that has mechanistic implications.

Evidence for chronic stress in captive but not free-ranging cheetahs (Acinonyx jubatus) based on adrenal morphology and function.

PubMed

Terio, Karen A; Marker, Laurie; Munson, Linda

2004-04-01

The cheetah (Acinonyx jubatus) is highly endangered because of loss of habitat in the wild and failure to thrive in captivity. Cheetahs in zoos reproduce poorly and have high prevalences of unusual diseases that cause morbidity and mortality. These diseases are rarely observed in free-ranging cheetahs but have been documented in cheetahs that have been captured and held in captive settings either temporarily or permanently. Because captivity may be stressful for this species and stress is suspected as contributing to poor health and reproduction, this study aimed to measure chronic stress by comparing baseline concentrations of fecal corticoid metabolites and adrenal gland morphology between captive and free-ranging cheetahs. Additionally, concentrations of estradiol and testosterone metabolites were quantified to determine whether concentrations of gonadal steroids correlated with corticoid concentration and to assure that corticosteroids in the free-ranging samples were not altered by environmental conditions. Concetntrations of fecal corticoids, estradiol, and testosterone were quantified by radioimmunoassay in 20 free-ranging and 20 captive cheetahs from samples collected between 1994 and 1999. Concentrations of baseline fecal corticoids were significantly higher (p = 0.005) in captive cheetahs (196.08 +/- 36.20 ng/g dry feces) than free-ranging cheetahs (71.40 +/- 14.35 ng/g dry feces). Testosterone concentrations were lower in captive male cheetahs (9.09 +/- 2.84 ng/g dry feces) than in free-ranging cheetahs (34.52 +/- 12.11 ng/g dry feces), which suggests suppression by elevated corticoids in the captive males. Evidence for similar sulppression of estradiol concentrations in females was not present. Adrenal corticomedullary ratios were determined on midsagittal sections of adrenal glands from 13 free-ranging and 13 captive cheetahs obtained between 1991 and 2002. The degree of vacuolation of cortical cells in the zona fasciculata was graded for each animal. Corticomedullary ratios were larger (p = 0.05) in captive cheetahs; however, there was no difference (p = 0.31) in the degree of corticocyte vacnolation between the two populations. These data proxile both mnorphologic and functional evidence suggestive of chronic stress in captive cheetahs. Further research into the role of hypercortisolemia in the pathogenesis of the reproductive abnormalities and unusual diseases of captive cheetahs is needed.

Television Image of a Large Upward Electrical Discharge Above a Thunderstorm System

NASA Astrophysics Data System (ADS)

Franz, R. C.; Nemzek, R. J.; Winckler, J. R.

1990-07-01

An image of an unusual luminous electrical discharge over a thunderstorm 250 kilometers from the observing site has been obtained with a low-light-level television camera. The discharge began at the cloud tops at 14 kilometers and extended into the clear air 20 kilometers higher. The image, which had a duration of less than 30 milliseconds, resembled two jets or fountains and was probably caused by two localized electric charge concentrations at the cloud tops. Large upward discharges may create a hazard for aircraft and rocket launches and, by penetrating into the ionosphere, may initiate whistler waves and other effects on a magnetospheric scale. Such upward electrical discharges may account for unexplained photometric observations of distant lightning events that showed a low rise rate of the luminous pulse and no electromagnetic sferic pulse of the type that accompanies cloud-to-earth lightning strokes. An unusually high rate of such photometric events was recorded during the night of 22 to 23 September 1989 during a storm associated with hurricane Hugo.

Television image of a large upward electrical discharge above a thunderstorm system.

PubMed

Franz, R C; Nemzek, R J; Winckler, J R

1990-07-06

An image of an unusual luminous electrical discharge over a thunderstorm 250 kilometers from the observing site has been obtained with a low-light-level television camera. The discharge began at the cloud tops at 14 kilometers and extended into the clear air 20 kilometers higher. The image, which had a duration of less than 30 milliseconds,resembled two jets or fountains and was probably caused by two localizd electric charge concentrations at the cloud tops. Large upward discharges may create a hazard for aircraft and rocket launches and, by penetrating into the ionosphere, may initiate whistler waves and other effects on a magnetospheric scale. Such upward electrical discharges may account for unexplained photometric observations of distant lightning events that showed a low rise rate of the luminous pulse and no electromagnetic sferic pulse of the type that accompanies cloud-to-earth lightning strokes. An unusually high rate of such photometric events was recorded during the night of 22 to 23 September 1989 during a storm associated with hurricane Hugo.

An unusual autopsy case of cytokine storm-derived influenza-associated encephalopathy without typical histopathological findings: autopsy case report.

PubMed

Nara, Akina; Nagai, Hisashi; Yamaguchi, Rutsuko; Yoshida, Ken-ichi; Iwase, Hirotaro; Mizuguchi, Masashi

2015-03-01

Cytokine storm-derived influenza-associated encephalopathy is a severe complication, affecting not only the brain but also multiple systemic organs including the heart and lungs. Hundreds of Japanese children are afflicted by influenza-associated encephalopathy every year. Influenza-associated encephalopathy can be diagnosed by pathological changes, such as advanced brain edema and disruption of astrocytic projections, which is known as clasmatodendrosis. In the present case, despite the absence of significant histopathological findings in the brain, the diagnosis of influenza-associated encephalopathy was made on the basis of autopsy findings such as brain swelling, pathological findings including diffuse alveolar damage, and increase in the concentrations of interleukin-6 in both the serum and cerebrospinal fluid. In this case, the interval from high fever to death was approximately 7 hours and may have been too short for histopathological features to develop. This is an unusual autopsy case of cytokine storm-derived influenza-associated encephalopathy without typical histopathological findings.

Magnetic properties and granulometry of metallic iron in lunar breccia 14313

NASA Technical Reports Server (NTRS)

Dunlop, D. J.; Gose, W. A.; Pearce, G. W.; Strangway, D. W.

1973-01-01

Based on a detailed study of time-dependent or viscous remanence (VRM), thermoremanence (TRM) and magnetic granulometry of soil breccia 14313, single-domain particles of iron 100 to 200 A in size are proposed as the major carriers of natural remanence (NRM) in this rock. The VRM of 14313 is unusually intense and exhibits a logarithmic time decrease of VRM which ceases fairly abruptly after a time about equal to the original exposure to the field. The partial TRM spectrum reveals both a high-blocking-temperature fraction, scarcely affected by AF demagnetization to 1000 Oe, and an unusual concentration of blocking temperatures just above room temperature. The former fraction would contribute a very hard and stable component to any NRM of lunar origin, but the latter fraction, which accounts for the pronounced VRM of 14313 and undoubtedly has imparted a large viscous NRM component in the earth's field, is also surprisingly hard. A substantial portion (20 to 40%) is not demagnetized by an 800-Oe field.

Low induction of non-photochemical quenching and high photochemical efficiency in the annual desert plant Anastatica hierochuntica.

PubMed

Eppel, Amir; Shaked, Ruth; Eshel, Gil; Barak, Simon; Rachmilevitch, Shimon

2014-08-01

Non-photochemical quenching (NPQ) plays a major role in photoprotection. Anastatica hierochuntica is an annual desert plant found in hot deserts. We compared A. hierochuntica to three other different species: Arabidopsis thaliana, Eutrema salsugineum and Helianthus annuus, which have different NPQ and photosynthetic capacities. Anastatica hierochuntica plants had very different induction kinetics of NPQ and, to a lesser extent, of photosystem II electron transport rate (PSII ETR), in comparison to all other plants species in the experiments. The major components of the unusual photosynthetic and photoprotective response in A. hierochuntica were: (1) Low NPQ at the beginning of the light period, at various light intensities and CO2 concentrations. The described low NPQ cannot be explained by low leaf absorbance or by low energy distribution to PSII, but was related to the de-epoxidation state of xanthophylls. (2) Relatively high PSII ETR at various CO2 concentrations in correlation with low NPQ. PSII ETR responded positively to the increase of CO2 concentrations. At low CO2 concentrations PSII ETR was mostly O2 dependent. At moderate and high CO2 concentrations the high PSII ETR in A. hierochuntica was accompanied by relatively high CO2 assimilation rates. We suggest that A. hierochuntica have an uncommon NPQ and PSII ETR response. These responses in A. hierochuntica might represent an adaptation to the short growing season of an annual desert plant. © 2013 Scandinavian Plant Physiology Society.

A Supramolecular Ice Growth Inhibitor.

PubMed

Drori, Ran; Li, Chao; Hu, Chunhua; Raiteri, Paolo; Rohl, Andrew L; Ward, Michael D; Kahr, Bart

2016-10-12

Safranine O, a synthetic dye, was found to inhibit growth of ice at millimolar concentrations with an activity comparable to that of highly evolved antifreeze glycoproteins. Safranine inhibits growth of ice crystals along the crystallographic a-axis, resulting in bipyramidal needles extended along the <0001> directions as well as and plane-specific thermal hysteresis (TH) activity. The interaction of safranine with ice is reversible, distinct from the previously reported behavior of antifreeze proteins. Spectroscopy and molecular dynamics indicate that safranine forms aggregates in aqueous solution at micromolar concentrations. Metadynamics simulations and aggregation theory suggested that as many as 30 safranine molecules were preorganized in stacks at the concentrations where ice growth inhibition was observed. The simulations and single-crystal X-ray structure of safranine revealed regularly spaced amino and methyl substituents in the aggregates, akin to the ice-binding site of antifreeze proteins. Collectively, these observations suggest an unusual link between supramolecular assemblies of small molecules and functional proteins.

Atom-efficient regioselective 1,2-dearomatization of functionalized pyridines by an earth-abundant organolanthanide catalyst

NASA Astrophysics Data System (ADS)

Dudnik, Alexander S.; Weidner, Victoria L.; Motta, Alessandro; Delferro, Massimiliano; Marks, Tobin J.

2014-12-01

Developing earth-abundant, non-platinum metal catalysts for high-value chemical transformations is a critical challenge to contemporary chemical synthesis. Dearomatization of pyridine derivatives is an important transformation to access a wide range of valuable nitrogenous natural products, pharmaceuticals and materials. Here, we report an efficient 1,2-regioselective organolanthanide-catalysed pyridine dearomatization process using pinacolborane, which is compatible with a broad range of pyridines and functional groups and employs equimolar reagent stoichiometry. Regarding the mechanism, derivation of the rate law from NMR spectroscopic and kinetic measurements suggests first order in catalyst concentration, fractional order in pyridine concentration and inverse first order in pinacolborane concentration, with C=N insertion into the La-H bond as turnover-determining. An energetic span analysis affords a more detailed understanding of experimental activity trends and the unusual kinetic behaviour, and proposes the catalyst ‘resting’ state and potential deactivation pathways.

Electron transport properties of degenerate n-type GaN prepared by pulsed sputtering

NASA Astrophysics Data System (ADS)

Ueno, Kohei; Fudetani, Taiga; Arakawa, Yasuaki; Kobayashi, Atsushi; Ohta, Jitsuo; Fujioka, Hiroshi

2017-12-01

We report a systematic investigation of the transport properties of highly degenerate electrons in Ge-doped and Si-doped GaN epilayers prepared using the pulsed sputtering deposition (PSD) technique. Secondary-ion mass spectrometry and Hall-effect measurements revealed that the doping efficiency of PSD n-type GaN is close to unity at electron concentrations as high as 5.1 × 1020 cm-3. A record low resistivity for n-type GaN of 0.16 mΩ cm was achieved with an electron mobility of 100 cm2 V-1 s-1 at a carrier concentration of 3.9 × 1020 cm-3. We explain this unusually high electron mobility of PSD n-type GaN within the framework of conventional scattering theory by modifying a parameter related to nonparabolicity of the conduction band. The Ge-doped GaN films show a slightly lower electron mobility compared with Si-doped films with the same carrier concentrations, which is likely a consequence of the formation of a small number of compensation centers. The excellent electrical properties presented in this letter clearly demonstrate the striking advantages of the low-temperature PSD technique for growing high-quality and highly conductive n-type GaN.

An ERP study of passive creative conceptual expansion using a modified alternate uses task.

PubMed

Kröger, Sören; Rutter, Barbara; Hill, Holger; Windmann, Sabine; Hermann, Christiane; Abraham, Anna

2013-08-21

A novel ERP paradigm was employed to investigate conceptual expansion, a central component of creative thinking. Participants were presented with word pairs, consisting of everyday objects and uses for these objects, which had to be judged based on the two defining criteria of creative products: unusualness and appropriateness. Three subject-determined trial types resulted from this judgement: high unusual and low appropriate (nonsensical uses), low unusual and high appropriate (common uses), and high unusual and high appropriate (creative uses). Word pairs of the creative uses type are held to passively induce conceptual expansion. The N400 component was not specifically modulated by conceptual expansion but was, instead, generally responsive as a function of unusualness or novelty of the stimuli (nonsense=creative>common). Explorative analyses in a later time window (500-900 ms) revealed that ERP activity in this phase indexes appropriateness (nonsense>creative=common). In the discussion of these findings with reference to the literature on semantic cognition, both components are proposed as indexing processes relevant to conceptual expansion as they are selectively involved in the encoding and integration of a newly established semantic connection between two previously unrelated concepts. Copyright © 2013 Elsevier B.V. All rights reserved.

The effect of high concentration additive on chiral separations in supercritical fluid chromatography.

PubMed

Speybrouck, David; Doublet, Charline; Cardinael, Pascal; Fiol-Petit, Catherine; Corens, David

2017-08-11

Supercritical Fluid Chromatography is frequently used to efficiently handle separations of enantiomers. The separation of basic analytes usually requires the addition of a basic additive in the mobile phase to improve the peak shape or even to elute the compounds. The effect of increasing the concentration of 2-propylamine as additive on the elution of a series of basic compounds on a Chiralpak-AD stationary phase was studied. In this study, unusual additive concentrations ranging from 0.3% to 10% of 2-propylamine 2-propylaminein the modifier were explored and the effect on retention, peak shape, selectivity and resolution was evaluated. The addition of a large quantity of additive allowed to drastically improve the selectivity and the resolution, and even enantiomers elution order reversal was observed by changing the concentration of basic additive. The role of the ratio additive/modifier appeared a key to tune the enantioselectivity. Finally, the impact of these drastic conditions on the column material was evaluated. Copyright © 2017 Elsevier B.V. All rights reserved.

Copernicus Measurement of the Jovian Lyman-alpha emission and its aeronomical significance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Atreya, S.K.; Festou, M.C.; Donahue, T.M.

1982-11-01

Observations of Jupiter made with the high-resolution ultraviolet spectrometer of the Orbiting Astronomical Observatory Copernicus in 1980 April and May yield the intensity of the Jovian Lyman-alpha emission to be 7 +- 2.5 kR. These measurements indicate that the Lyman-alpha intensity has decreased by about a factor of 2 from the time of the Voyager ultraviolet spectrometer measurements, nearly a year earlier. The Copernicus measurements, when combined with all other previous measurements of the Jovian Lyman-alpha emission, point to an unusually high column abundance of hydrogen atoms above the methane homopause at the Voyager epoch. Since the auroral charged particlemore » bombardment of moelcular hydrogen is expected to contribute significantly to the global population of the hydrogen atoms, it is suggested that at the time of the Voyager Jupiter encounter, unusually high auroral activity existed, and it was perhaps linked to the high concentration of the Io plasma torus. It should be pointed out that the temporal variation of the Saturn Lyman-alpha emission, when contrasted with the Jovian data, reveals that the auroral processes are not nearly as important in determining the Saturn Lyman-alpha intensity in the nonauroral region. The latest Copernicus observations also suggest an increase in the Jovian homopause value of the eddy mixing coefficient by about a factor of 5--10 since the Voyager epoch.« less

Field drains as a route of rapid nutrient export from agricultural land receiving biosolids.

PubMed

Heathwaite, A L; Burke, S P; Bolton, L

2006-07-15

We report research on the environmental risk of incidental nutrient transfers from land to water for biosolids amended soils. We show that subsurface (drainflow) pathways of P transport may result in significant concentrations, up to 10 mg total P l(-1), in the drainage network of an arable catchment when a P source (recent biosolids application) coincides with a significant and active transport pathway (rainfall event). However, the high P concentrations were short-lived, with drainage ditch total P concentrations returning to pre-storm concentrations within a few days of the storm event. In the case of the drainflow concentrations reported here, the results are unusual in that they describe an 'incidental event' for a groundwater catchment where such events might normally be expected to be rare owing to the capacity of the hydrological system to attenuate nutrient fluxes for highly adsorbed elements such as P. Consequently, there is a potential risk of P transfers to shallow groundwater systems. We suggest that the findings are not specific to biosolids-alone, which is a highly regulated industry, but that similar results may be anticipated had livestock waste or mineral fertilizer been applied, although the magnitude of losses may differ. The risk appears to be more one of timing and the availability of a rapid transport pathway than of P source.

Unusual and highly tunable missing-linker defects in zirconium metal-organic framework UiO-66 and their important effects on gas adsorption.

PubMed

Wu, Hui; Chua, Yong Shen; Krungleviciute, Vaiva; Tyagi, Madhusudan; Chen, Ping; Yildirim, Taner; Zhou, Wei

2013-07-17

UiO-66 is a highly important prototypical zirconium metal-organic framework (MOF) compound because of its excellent stabilities not typically found in common porous MOFs. In its perfect crystal structure, each Zr metal center is fully coordinated by 12 organic linkers to form a highly connected framework. Using high-resolution neutron power diffraction technique, we found the first direct structural evidence showing that real UiO-66 material contains significant amount of missing-linker defects, an unusual phenomenon for MOFs. The concentration of the missing-linker defects is surprisingly high, ∼10% in our sample, effectively reducing the framework connection from 12 to ∼11. We show that by varying the concentration of the acetic acid modulator and the synthesis time, the linker vacancies can be tuned systematically, leading to dramatically enhanced porosity. We obtained samples with pore volumes ranging from 0.44 to 1.0 cm(3)/g and Brunauer-Emmett-Teller surface areas ranging from 1000 to 1600 m(2)/g, the largest values of which are ∼150% and ∼60% higher than the theoretical values of defect-free UiO-66 crystal, respectively. The linker vacancies also have profound effects on the gas adsorption behaviors of UiO-66, in particular CO2. Finally, comparing the gas adsorption of hydroxylated and dehydroxylated UiO-66, we found that the former performs systematically better than the latter (particularly for CO2) suggesting the beneficial effect of the -OH groups. This finding is of great importance because hydroxylated UiO-66 is the practically more relevant, non-air-sensitive form of this MOF. The preferred gas adsorption on the metal center was confirmed by neutron diffraction measurements, and the gas binding strength enhancement by the -OH group was further supported by our first-principles calculations.

Metagenomic insights into strategies of carbon conservation and unusual sulfur biogeochemistry in a hypersaline Antarctic lake

PubMed Central

Yau, Sheree; Lauro, Federico M; Williams, Timothy J; DeMaere, Matthew Z; Brown, Mark V; Rich, John; Gibson, John AE; Cavicchioli, Ricardo

2013-01-01

Organic Lake is a shallow, marine-derived hypersaline lake in the Vestfold Hills, Antarctica that has the highest reported concentration of dimethylsulfide (DMS) in a natural body of water. To determine the composition and functional potential of the microbial community and learn about the unusual sulfur chemistry in Organic Lake, shotgun metagenomics was performed on size-fractionated samples collected along a depth profile. Eucaryal phytoflagellates were the main photosynthetic organisms. Bacteria were dominated by the globally distributed heterotrophic taxa Marinobacter, Roseovarius and Psychroflexus. The dominance of heterotrophic degradation, coupled with low fixation potential, indicates possible net carbon loss. However, abundant marker genes for aerobic anoxygenic phototrophy, sulfur oxidation, rhodopsins and CO oxidation were also linked to the dominant heterotrophic bacteria, and indicate the use of photo- and lithoheterotrophy as mechanisms for conserving organic carbon. Similarly, a high genetic potential for the recycling of nitrogen compounds likely functions to retain fixed nitrogen in the lake. Dimethylsulfoniopropionate (DMSP) lyase genes were abundant, indicating that DMSP is a significant carbon and energy source. Unlike marine environments, DMSP demethylases were less abundant, indicating that DMSP cleavage is the likely source of high DMS concentration. DMSP cleavage, carbon mixotrophy (photoheterotrophy and lithoheterotrophy) and nitrogen remineralization by dominant Organic Lake bacteria are potentially important adaptations to nutrient constraints. In particular, carbon mixotrophy relieves the extent of carbon oxidation for energy production, allowing more carbon to be used for biosynthetic processes. The study sheds light on how the microbial community has adapted to this unique Antarctic lake environment. PMID:23619305

Optical conductivity of three and two dimensional topological nodal-line semimetals

NASA Astrophysics Data System (ADS)

Barati, Shahin; Abedinpour, Saeed H.

2017-10-01

The peculiar shape of the Fermi surface of topological nodal-line semimetals at low carrier concentrations results in their unusual optical and transport properties. We analytically investigate the linear optical responses of three- and two-dimensional nodal-line semimetals using the Kubo formula. The optical conductivity of a three-dimensional nodal-line semimetal is anisotropic. Along the axial direction (i.e., the direction perpendicular to the nodal-ring plane), the Drude weight has a linear dependence on the chemical potential at both low and high carrier dopings. For the radial direction (i.e., the direction parallel to the nodal-ring plane), this dependence changes from linear into quadratic in the transition from low into high carrier concentration. The interband contribution into optical conductivity is also anisotropic. In particular, at large frequencies, it saturates to a constant value for the axial direction and linearly increases with frequency along the radial direction. In two-dimensional nodal-line semimetals, no interband optical transition could be induced and the only contribution to the optical conductivity arises from the intraband excitations. The corresponding Drude weight is independent of the carrier density at low carrier concentrations and linearly increases with chemical potential at high carrier doping.

Reproductive endocrine patterns and volatile urinary compounds of Arctictis binturong: discovering why bearcats smell like popcorn.

PubMed

Greene, Lydia K; Wallen, Timothy W; Moresco, Anneke; Goodwin, Thomas E; Drea, Christine M

2016-06-01

Members of the order Carnivora rely on urinary scent signaling, particularly for communicating about reproductive parameters. Here, we describe reproductive endocrine patterns in relation to urinary olfactory cues in a vulnerable and relatively unknown viverrid--the binturong (Arctictis binturong). Female binturongs are larger than and dominate males, and both sexes engage in glandular and urinary scent marking. Using a large (n = 33), captive population, we collected serum samples to measure circulating sex steroids via enzyme immunoassay and urine samples to assay volatile chemicals via gas chromatography-mass spectrometry. Male binturongs had expectedly greater androgen concentrations than did females but, more unusually, had equal estrogen concentrations, which may be linked to male deference. Males also expressed a significantly richer array of volatile chemical compounds than did females. A subset of these volatile chemicals resisted decay at ambient temperatures, potentially indicating their importance as long-lasting semiochemicals. Among these compounds was 2-acetyl-1-pyrroline (2-AP), which is typically produced at high temperatures by the Maillard reaction and is likely to be responsible for the binturong's characteristic popcorn aroma. 2-AP, the only compound expressed by all of the subjects, was found in greater abundance in males than females and was significantly and positively related to circulating androstenedione concentrations in both sexes. This unusual compound may have a more significant role in mammalian semiochemistry than previously appreciated. Based on these novel data, we suggest that hormonal action and potentially complex chemical reactions mediate communication of the binturong's signature scent and convey information about sex and reproductive state.

Reproductive endocrine patterns and volatile urinary compounds of Arctictis binturong: discovering why bearcats smell like popcorn

NASA Astrophysics Data System (ADS)

Greene, Lydia K.; Wallen, Timothy W.; Moresco, Anneke; Goodwin, Thomas E.; Drea, Christine M.

2016-06-01

Members of the order Carnivora rely on urinary scent signaling, particularly for communicating about reproductive parameters. Here, we describe reproductive endocrine patterns in relation to urinary olfactory cues in a vulnerable and relatively unknown viverrid—the binturong ( Arctictis binturong). Female binturongs are larger than and dominate males, and both sexes engage in glandular and urinary scent marking. Using a large ( n = 33), captive population, we collected serum samples to measure circulating sex steroids via enzyme immunoassay and urine samples to assay volatile chemicals via gas chromatography-mass spectrometry. Male binturongs had expectedly greater androgen concentrations than did females but, more unusually, had equal estrogen concentrations, which may be linked to male deference. Males also expressed a significantly richer array of volatile chemical compounds than did females. A subset of these volatile chemicals resisted decay at ambient temperatures, potentially indicating their importance as long-lasting semiochemicals. Among these compounds was 2-acetyl-1-pyrroline (2-AP), which is typically produced at high temperatures by the Maillard reaction and is likely to be responsible for the binturong's characteristic popcorn aroma. 2-AP, the only compound expressed by all of the subjects, was found in greater abundance in males than females and was significantly and positively related to circulating androstenedione concentrations in both sexes. This unusual compound may have a more significant role in mammalian semiochemistry than previously appreciated. Based on these novel data, we suggest that hormonal action and potentially complex chemical reactions mediate communication of the binturong's signature scent and convey information about sex and reproductive state.

Origin of unusual HREE-Mo-rich carbonatites in the Qinling orogen, China

NASA Astrophysics Data System (ADS)

Song, Wenlei; Xu, Cheng; Smith, Martin P.; Kynicky, Jindrich; Huang, Kangjun; Wei, Chunwan; Zhou, Li; Shu, Qihai

2016-11-01

Carbonatites, usually occurring within intra-continental rift-related settings, have strong light rare earth element (LREE) enrichment; they rarely contain economic heavy REE (HREE). Here, we report the identification of Late Triassic HREE-Mo-rich carbonatites in the northernmost Qinling orogen. The rocks contain abundant primary HREE minerals and molybdenite. Calcite-hosted fluid inclusions, inferred to represent a magmatic-derived aqueous fluid phase, contain significant concentrations of Mo (~17 ppm), reinforcing the inference that these carbonatitic magmas had high Mo concentrations. By contrast, Late Triassic carbonatites in southernmost Qinling have economic LREE concentrations, but are depleted in HREE and Mo. Both of these carbonatite types have low δ26Mg values (-1.89 to -1.07‰), similar to sedimentary carbonates, suggesting a recycled sediment contribution for REE enrichment in their mantle sources. We propose that the carbonatites in the Qinling orogen were formed, at least in part, by the melting of a subducted carbonate-bearing slab, and that 10 Ma younger carbonatite magmas in the northernmost Qinling metasomatized the thickened eclogitic lower crust to produce high levels of HREE and Mo.

Origin of unusual HREE-Mo-rich carbonatites in the Qinling orogen, China.

PubMed

Song, Wenlei; Xu, Cheng; Smith, Martin P; Kynicky, Jindrich; Huang, Kangjun; Wei, Chunwan; Zhou, Li; Shu, Qihai

2016-11-18

Carbonatites, usually occurring within intra-continental rift-related settings, have strong light rare earth element (LREE) enrichment; they rarely contain economic heavy REE (HREE). Here, we report the identification of Late Triassic HREE-Mo-rich carbonatites in the northernmost Qinling orogen. The rocks contain abundant primary HREE minerals and molybdenite. Calcite-hosted fluid inclusions, inferred to represent a magmatic-derived aqueous fluid phase, contain significant concentrations of Mo (~17 ppm), reinforcing the inference that these carbonatitic magmas had high Mo concentrations. By contrast, Late Triassic carbonatites in southernmost Qinling have economic LREE concentrations, but are depleted in HREE and Mo. Both of these carbonatite types have low δ 26 Mg values (-1.89 to -1.07‰), similar to sedimentary carbonates, suggesting a recycled sediment contribution for REE enrichment in their mantle sources. We propose that the carbonatites in the Qinling orogen were formed, at least in part, by the melting of a subducted carbonate-bearing slab, and that 10 Ma younger carbonatite magmas in the northernmost Qinling metasomatized the thickened eclogitic lower crust to produce high levels of HREE and Mo.

Tuning the surface anisotropy in Fe-doped NiO nanoparticles.

PubMed

Moura, K O; Lima, R J S; Coelho, A A; Souza-Junior, E A; Duque, J G S; Meneses, C T

2014-01-07

Ni(1-x)FexO nanoparticles have been obtained by the co-precipitation chemical route. X-ray diffraction analyses using Rietveld refinement have shown a slight decrease in the microstrain and mean particle size as a function of the Fe content. The zero-field-cooling (ZFC) and field-cooling (FC) magnetization curves show superparamagnetic behavior at high temperatures and a low temperature peak (at T = 11 K), which is enhanced with increasing Fe concentration. Unusual behavior of the coercive field in the low temperature region and an exchange bias behavior were also observed. A decrease in the Fe concentration induces an increase in the exchange bias field. We argue that these behaviors can be linked with the strengthening of surface anisotropy caused by the incorporation of Fe ions.

Temperature-Responsive Luminescent Solar Concentrators: Tuning Energy Transfer in a Liquid Crystalline Matrix.

PubMed

Sol, Jeroen A H P; Dehm, Volker; Hecht, Reinhard; Würthner, Frank; Schenning, Albertus P H J; Debije, Michael G

2018-01-22

Temperature-responsive luminescent solar concentrators (LSCs) have been fabricated in which the Förster resonance energy transfer (FRET) between a donor-acceptor pair in a liquid crystalline solvent can be tuned. At room temperatures, the perylene bisimide (PBI) acceptor is aggregated and FRET is inactive; while after heating to a temperature above the isotropic phase of the liquid crystal solvent, the acceptor PBI completely dissolves and FRET is activated. This unusual temperature control over FRET was used to design a color-tunable LSC. The device has been shown to be highly stable towards consecutive heating and cooling cycles, making it an appealing device for harvesting otherwise unused solar energy. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

2. GORGE HIGH DAM. UNUSUALLY HIGH WATER IN GORGE LAKE ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. GORGE HIGH DAM. UNUSUALLY HIGH WATER IN GORGE LAKE DUE TO THE COMBINATION OF UNIT 24 BEING DOWN FOR REWINDING AND TWO UNITS COMING ON LINE UNEXPECTEDLY AT ROSS POWERHOUSE LED TO WATER FLOWING OVER THE SPILLGATES. EACH GATE IF 47 FEET WIDE AND 50 FEET HIGH, 1989. - Skagit Power Development, Gorge High Dam, On Skagit River, 2.9 miles upstream from Newhalem, Newhalem, Whatcom County, WA

Intergranular fracture in irradiated Inconel X-750 containing very high concentrations of helium and hydrogen

DOE Office of Scientific and Technical Information (OSTI.GOV)

Judge, Colin D.; Gauquelin, Nicolas; Walters, Lori

2015-02-01

In recent years, it has been determined that Inconel X-750 CANDU spacers have lost strength and material ductility following irradiation in reactor. The irradiated fracture behaviour of ex-service material was also found to be entirely intergranular. The heavily thermalized flux spectrum in a CANDU reactor results in transmutation of 58Ni to 59Ni. The 59Ni itself has unusually high thermal neutron reaction cross-sections of the type: (n, γ), (n, p), and (n,α). The latter two reactions, in particular, contribute to a significant enhancement of the atomic displacements in addition to creating high concentrations of hydrogen and helium within the material. Metallographicmore » examinations by transmission electron microscopy (TEM) have confirmed the presence of helium bubbles in the matrix and aligned along grain boundaries and matrix-precipitate interfaces. He bubble size and density are found to be highly dependent on the irradiation temperature and material microstructure; the bubbles are larger within grain boundary precipitates. TEM specimens extracted from fracture surfaces and crack tips give direct evidence linking crack propagation with grain boundary He bubbles.« less

An Ultrasonic Multi-Beam Concentration Meter with a Neuro-Fuzzy Algorithm for Water Treatment Plants

PubMed Central

Lee, Ho-Hyun; Jang, Sang-Bok; Shin, Gang-Wook; Hong, Sung-Taek; Lee, Dae-Jong; Chun, Myung Geun

2015-01-01

Ultrasonic concentration meters have widely been used at water purification, sewage treatment and waste water treatment plants to sort and transfer high concentration sludges and to control the amount of chemical dosage. When an unusual substance is contained in the sludge, however, the attenuation of ultrasonic waves could be increased or not be transmitted to the receiver. In this case, the value measured by a concentration meter is higher than the actual density value or vibration. As well, it is difficult to automate the residuals treatment process according to the various problems such as sludge attachment or sensor failure. An ultrasonic multi-beam concentration sensor was considered to solve these problems, but an abnormal concentration value of a specific ultrasonic beam degrades the accuracy of the entire measurement in case of using a conventional arithmetic mean for all measurement values, so this paper proposes a method to improve the accuracy of the sludge concentration determination by choosing reliable sensor values and applying a neuro-fuzzy learning algorithm. The newly developed meter is proven to render useful results from a variety of experiments on a real water treatment plant. PMID:26512666

An Ultrasonic Multi-Beam Concentration Meter with a Neuro-Fuzzy Algorithm for Water Treatment Plants.

PubMed

Lee, Ho-Hyun; Jang, Sang-Bok; Shin, Gang-Wook; Hong, Sung-Taek; Lee, Dae-Jong; Chun, Myung Geun

2015-10-23

Ultrasonic concentration meters have widely been used at water purification, sewage treatment and waste water treatment plants to sort and transfer high concentration sludges and to control the amount of chemical dosage. When an unusual substance is contained in the sludge, however, the attenuation of ultrasonic waves could be increased or not be transmitted to the receiver. In this case, the value measured by a concentration meter is higher than the actual density value or vibration. As well, it is difficult to automate the residuals treatment process according to the various problems such as sludge attachment or sensor failure. An ultrasonic multi-beam concentration sensor was considered to solve these problems, but an abnormal concentration value of a specific ultrasonic beam degrades the accuracy of the entire measurement in case of using a conventional arithmetic mean for all measurement values, so this paper proposes a method to improve the accuracy of the sludge concentration determination by choosing reliable sensor values and applying a neuro-fuzzy learning algorithm. The newly developed meter is proven to render useful results from a variety of experiments on a real water treatment plant.

Unusual way of suicide by carbon monoxide. Case Report.

PubMed

Zelený, Michal; Pivnička, Jan; Šindler, Martin; Kukleta, Pavel

2015-01-01

Authors discuss the case of a suicide of a 29-year-old man caused by carbon monoxide (CO) intoxication. What the authors found interesting was the unusual way of committing suicide that required good technical skills and expert knowledge. The level of carboxyhemoglobin (COHb) in the blood of the deceased man was routinely determined by the modified method by Blackmoore (1970), using gas chromatography/thermal conductivity detection. The level of saturation of the hemoglobin by CO in the collected blood sample is determined relatively to the same sample saturated to 100%. In the blood sample of the deceased man the lethal concentration of COHb of 76.5% was determined. Within the following examinations the blood alcohol concentration of 0.05 g.kg(-1) was determined. Further analysis revealed traces of sertraline, its metabolite N-desmethylsertraline, omeprazole and caffeine in the liver tissue, traces of N-desmethylsertraline, ibuprofen and caffeine in urine sample, and only traces of caffeine in the stomach content and blood samples were proved. To commit suicide the man used a sophisticated double container-system equipped with a timer for controlled generation of CO based on the chemical reaction of concentrated sulphuric acid and formic acid. The used timer was set by an electromechanical timer switch that triggered the fatal reaction of the acids while the man was sleeping. The authors discuss an unusual case of suicide by CO intoxication rarely seen in the area of forensic medicine and toxicology that is specific due to its sophisticated way of execution.

Triacylglycerols determine the unusual storage physiology of Cuphea seed.

PubMed

Crane, Jennifer; Miller, Annette L; van Roekel, J William; Walters, Christina

2003-09-01

Many species within the genus Cuphea (Lythraceae) produce seed with high levels of medium-chain fatty acids. Seeds of some Cuphea species lose viability when placed into storage at -18 degrees C. These species tolerate significant drying to 0.05 g/g and may, therefore, be intermediate in their storage characteristics. The thermal properties of seed lipids were observed using differential scanning calorimetry. Species with peak lipid melting temperatures >/=27 degrees C were found to be sensitive to -18 degrees C exposure while those with melting temperatures <27 degrees C were able to tolerate low-temperature exposure. This relationship was determined by the triacylglycerol composition of the individual species. Sensitive species have high concentrations of lauric acid (C(12)) and/or myristic acid (C(14)). Species with high concentrations of capric (C(8)) or caprylic acid (C(10)) or with high concentrations of unsaturated fatty acids tolerate low temperature exposure. Potential damage caused by low temperature exposure can be avoided by exposing seeds to a brief heat pulse of 45 degrees C to melt solidified lipids prior to imbibition. The relationship between the behavior of triacylglycerols in vivo, seed storage behavior and sensitivity to imbibitional damage is previously unreported and may apply to other species with physiologies that make them difficult to store.

Leaching of silicon from ferronickel (FeNi) smelting slag with sodium hydroxide solution at atmospheric pressure

NASA Astrophysics Data System (ADS)

Mufakhir, F. R.; Mubarok, M. Z.; Ichlas, Z. T.

2018-01-01

The present paper reports the leaching behavior of silicon from ferronickel slag under atmospheric pressure using sodium hydroxide solution. The effect of several experimental variables, namely concentration of leaching agent, operating temperature, stirring speed, and slurry density was investigated. The leaching kinetic was also investigated by using shrinking core model. It was determined that leaching of silicon from the slag was controlled by diffusion through product layer, although the activation energy was found to be 85.84 kJ/mol, which was unusually high for such a diffusion-controlled process.

Melorheostosis and FGF-23: is there a relationship?

PubMed

Kerkeni, Samar; Chapurlat, Roland

2008-07-01

Melorheostosis is a rare chronic bone disease of unknown etiology that often affects lower limbs. Onset usually occurs in childhood or early adolescence. The diagnosis relies on the radiographic finding of hyperostosis within or around the cortex responsible for a "flowing wax" appearance. To our knowledge, Fibroblast growth factor-23 (FGF-23) levels have not yet been quantified in melorheostosis. We report an unusual case of this disease for whom the diagnosis of fibrous dysplasia had been wrongly made for a long period of time and the FGF-23 concentration has been found very high without any disturbance of serum phosphate.

Ice Volcanoes on Pluto?

NASA Image and Video Library

2015-11-10

NASA New Horizons scientists believe that the informally named feature Wright Mons, located south of Sputnik Planum on Pluto, and another, Piccard Mons, could have been formed by the cryovolcanic eruption of ices from beneath Pluto surface. Sputnik Planum on Pluto, is an unusual feature that's about 100 miles (160 kilometers) wide and 13,000 feet (4 kilometers) high. It displays a summit depression (visible in the center of the image) that's approximately 35 miles (56 kilometers) across, with a distinctive hummocky texture on its sides. The rim of the summit depression also shows concentric fracturing. http://photojournal.jpl.nasa.gov/catalog/PIA20155

Ferromagnetic ordering in Mn-doped quantum wells GaAs-AlGaAs resulting from the virtual Anderson transition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Agrinskaya, N. V.; Berezovets, V. A.; Bouravlev, A.

We present our results obtained for Mn-doped GaAs quantum wells where the evidences of the ferromagnetic transition at relatively high temperatures were found at unusually small Mn concentrations. The observed values of hopping resistance at small temperatures evidenced that the samples are deep in the insulating regime. Thus the corresponding estimates of the overlapping integrals can hardly explain the large values of Curie temperatures T{sub c} ≃ 100 K. We develop a theoretical model qualitatively explaining the experimental results basing on the concept of virtual Anderson transition.

Reconnaissance of the water resources of the Hoh Indian Reservation and the Hoh River basin, Washington

USGS Publications Warehouse

Lum, W.E.; Nelson, L.M.

1986-01-01

Ground- and surface-water resources of the Hoh Indian Reservation and the Hoh River basin were studied from 1977 to 1980 under a cooperative agreement between the U.S. Geological Survey and the Hoh Indian Tribe. It was determined that moderate quantities of groundwater can be obtained from near-surface, river-deposited sands and gravels on the northeastern part of the reservation. Groundwater recharge (induced by pumping from a nearby oxbow lake) could supply numerous wells indefinitely with yields of 25 to 50 gallons/min. Geologic units in other areas of the reservation appear to have a low hydraulic conductivity and would yield little, if any, water to wells. At seven sites where housing construction is planned, soils were tested for infiltration rates and it was determined that soils are adequate for waste disposal in septic tanks and associated drain fields at those locations. Chalaat Creek, which flows across the reservation, provides water for salmon-rearing ponds. Except for moderately high bacteria concentrations (fecal coliform bacteria concentrations were as high as 33 colonies/100 mL), results of water quality analyses indicate no unusual or harmful concentrations of any chemical constituent or physical properties of the water that would restrict its use for most purposes. Chemical and bacteriological analyses of the Hoh River and its major tributaries downstream from the Olympic Park boundary revealed no unusual or harmful levels of constituents, with some minor exceptions. Small increases in concentrations of sodium, chloride, nitrite plus nitrate, and turbidity were measured in water samples collected from the Hoh River in a downstream direction. These increases are probably the result of natural weathering of rocks and soils in the basin. Fluvial-sediment transport of the Hoh River was 82,000 tons from March 1978 to February 1979 and 1,510,000 tons from March 1979 to February 1980. Mean annual transport was estimated to be 630 ,000 tons. About 60% of the sediment transported by the Hoh River originates from within the boundaries of the Olympic National Park, which includes about 70% of the area of the Hoh River drainage basin. (USGS)

Evaluation of Drugs for Prevention of Hyperthermia in Rats Exposed to Microwave Irradiation.

DTIC Science & Technology

1987-03-04

is deficient in antidiuretic hormone (ADH) and has diabetes insipidus (DI). The latter condition causes unusually high water intake and urine...ADH) and consequently has diabetes ihsipidus (DI). A DI-rat, also known as Brattleboro rat, has both unusually high water intake and rate of

An unexpected tetanus case.

PubMed

Ergonul, Onder; Egeli, Demet; Kahyaoglu, Bulent; Bahar, Mois; Etienne, Mill; Bleck, Thomas

2016-06-01

1 million cases of tetanus are estimated to occur worldwide each year, with more than 200 000 deaths. Tetanus is a life-threatening but preventable disease caused by a toxin produced by Clostridium tetani-a Gram-positive bacillus found in high concentrations in soil and animal excrement. Tetanus is almost completely preventable by active immunisation, but very rarely unexpected cases can occur in individuals who have been previously vaccinated. We report a case of generalised tetanus in a 22-year-old woman that arose despite the protective antitoxin antibody in her serum. The patient received all her vaccinations in the USA; her last vaccination was 6 years ago. The case was unusual because the patient had received all standard vaccinations, had no defined port of entry at disease onset, and had symptoms lasting for 6 months. Tetanus can present with unusual clinical forms; therefore, the diagnosis and management of this rare but difficult disease should be updated. In this Grand Round, we review the clinical features, epidemiology, treatment, and prognosis of C tetani infections. Copyright © 2016 Elsevier Ltd. All rights reserved.

Plasma methylphenidate concentrations in youths treated with high-dose osmotic release oral system formulation.

PubMed

Stevens, Jonathan R; George, Robert A; Fusillo, Steven; Stern, Theodore A; Wilens, Timothy E

2010-02-01

Children and adolescents are being treated increasingly for attention-deficit/hyperactivity disorder (ADHD) with a variety of stimulants in higher than Food and Drug Administration (FDA)-approved doses and in combination with other medications. We sought to determine methylphenidate (MPH) concentrations in children and adolescents treated with high-dose, extended-release osmotic release oral system (OROS) MPH plus concomitant medications, and to examine MPH concentrations with respect to the safety and tolerability of treatment. Plasma MPH concentrations were measured by liquid chromatography-mass spectrometry 4-5 hours after administration of medication in a sample of youths diagnosed with ADHD. These youths were treated naturalistically with higher than FDA-approved doses of OROS MPH in addition to their concomitant medications. Markers of safety and tolerability (e.g., measures of blood pressure and heart rate) were also examined. Among the 17 patients (with a mean age of 16.2 +/- 2 years and a mean number of concurrent medications of 2.23 +/- 0.94), the mean plasma MPH concentration was 28 +/- 9.1 ng/mL, despite a mean daily dose of OROS MPH of 169 +/- 5 mg (3.0 +/- 0.8 mg/kg per day). No patient had a plasma MPH level >or=50 ng/mL or clinical signs of stimulant toxicity. No correlation was found between plasma MPH concentrations and OROS MPH dose or changes in vital signs. High-dose OROS MPH, used in combination with other medications, was not associated with either unusually elevated plasma MPH concentrations or with clinically meaningful changes in vital signs. Study limitations include a single time-point sampling of MPH concentrations, a small sample size, and a lack of outcome measures to address treatment effectiveness.

Particulate organic matter delta C-13 variations across the Drake Passage

NASA Technical Reports Server (NTRS)

Rau, G. H.; Takahashi, T.; Des Marais, D. J.; Sullivan, C. W.

1991-01-01

Particulate organic matter (POM) was sampled during two cruise transects across the Drake Passage during March 1986 to investigate the unusual C-13 depletion in high-latitude Southern Ocean plankton. This POM delta C-13 transition from -23.2 o/oo at 53.3 deg S to values as low as -30.3 o/oo at above 62 deg S does not track previously reported abrupt changes in water chemistry and plankton species composition associated with the Polar Front Zone. The north-south isotopic trend is not accompanied by significant changes in POM carbon or nitrogen concentrations, or in POM C/N. Differences in plankton standing crop or biochemistry (e.g. lipid content) do not appear responsible for the isotopic trends observed. The latitudinal change in POM delta C-13 is highly correlated with water temperature and with the calculated concentration of CO2 (aq) at equilibrium with atmospheric CO2. These observations are consistent with the hypothesis that CO2 (aq) significantly influences POM delta C-13 in ocean surface waters.

Spatial distribution and historical trends of heavy metals in the sediments of petroleum producing regions of the Beibu Gulf, China.

PubMed

Yang, Jichao; Wang, Weiguo; Zhao, Mengwei; Chen, Bin; Dada, Olusegun A; Chu, Zhihui

2015-02-15

The concentrations of As, Sb, Hg, Pb, Cd, and Ba in the surface and core sediments of the oil and gas producing region of the Beibu Gulf were measured by Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES), Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and Atomic Fluorescence Spectrometry (AFS), and the spatial distribution and historical trends of these elements are discussed. The results show that the concentrations of these elements are highest near the platforms. The results of Enrichment Factor (EF) and Potential Ecological Risk Index (PERI) also reveal significantly higher enrichment around the platforms, which imply that the offshore petroleum production was the cause of the unusual distribution and severe enrichment of these elements in the study area. The environment around the platforms was highly laden with toxic elements, thereby representing a very high ecological risk to the environment of the study area. Copyright © 2014 Elsevier Ltd. All rights reserved.

Massive spalling of intermetallic compounds in solder-substrate reactions due to limited supply of the active element

NASA Astrophysics Data System (ADS)

Yang, S. C.; Ho, C. E.; Chang, C. W.; Kao, C. R.

2007-04-01

Massive spalling of intermetallic compounds has been reported in the literature for several solder/substrate systems, including SnAgCu soldered on Ni substrate, SnZn on Cu, high-Pb PbSn on Cu, and high-Pb PbSn on Ni. In this work, a unified thermodynamic argument is proposed to explain this rather unusual phenomenon. According to this argument, two necessary conditions must be met. The number one condition is that at least one of the reactive constituents of the solder must be present in a limited amount, and the second condition is that the soldering reaction has to be very sensitive to its concentration. With the growth of intermetallic, more and more atoms of this constituent are extracted out of the solder and incorporated into the intermetallic. As the concentration of this constituent decreases, the original intermetallic at the interface becomes a nonequilibrium phase, and the spalling of the original intermetallic occurs.

Massive spalling of intermetallic compounds in solder-substrate reactions due to limited supply of the active element

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, S. C.; Ho, C. E.; Chang, C. W.

2007-04-15

Massive spalling of intermetallic compounds has been reported in the literature for several solder/substrate systems, including SnAgCu soldered on Ni substrate, SnZn on Cu, high-Pb PbSn on Cu, and high-Pb PbSn on Ni. In this work, a unified thermodynamic argument is proposed to explain this rather unusual phenomenon. According to this argument, two necessary conditions must be met. The number one condition is that at least one of the reactive constituents of the solder must be present in a limited amount, and the second condition is that the soldering reaction has to be very sensitive to its concentration. With themore » growth of intermetallic, more and more atoms of this constituent are extracted out of the solder and incorporated into the intermetallic. As the concentration of this constituent decreases, the original intermetallic at the interface becomes a nonequilibrium phase, and the spalling of the original intermetallic occurs.« less

Air pollution in Polish cities during January 2017 - an episode study

NASA Astrophysics Data System (ADS)

Durka, Pawel; Kaminski, Jacek W.; Struzewska, Joanna

2017-04-01

Poor air quality is a health issue in Poland, especially during winter. Six cities in Poland are in the top 10 and 33 cities are in the top 50 most polluted cities in Europe. In the first days of January 2017, there was a drastic change in the weather patterns over Central Europe. Temperatures dropped below -20oC in only a couple of days with calm wind conditions. Meteorological soundings showed inversions up to hundreds of meters above the surface. In such conditions PM10 and PM2.5 concentrations were unusually high. Thresholds were exceeded in most of the cities in Poland. In some of the cities PM concentrations were very high: reaching 1600 µg/m3 in Rybnik, 1300 µg/m3 in Zabrze, 1000 µg/m3 in Gliwice, 700 µg/m3 in Katowice. Most likely the main source of the pollution event were domestic emissions as well as traffic emissions. High concentration values were due to the stratification of the atmosphere. Nearly all cities issued smog alerts. The majority of the cities introduced free public transportation and schools were closed. We will show the evolution of this episode in the selected cities for the period when the highest concentrations measured and forecasted - from 7 to 11 January 2017. The synoptic situation for the episode will be discussed.

Unusual metabolic diversity of hyperalkaliphilic microbial communities associated with subterranean serpentinization at The Cedars.

PubMed

Suzuki, Shino; Ishii, Shun'ichi; Hoshino, Tatsuhiko; Rietze, Amanda; Tenney, Aaron; Morrill, Penny L; Inagaki, Fumio; Kuenen, J Gijs; Nealson, Kenneth H

2017-11-01

Water from The Cedars springs that discharge from serpentinized ultramafic rocks feature highly basic (pH=~12), highly reducing (E h <-550 mV) conditions with low ionic concentrations. These conditions make the springs exceptionally challenging for life. Here, we report the metagenomic data and recovered draft genomes from two different springs, GPS1 and BS5. GPS1, which was fed solely by a deep groundwater source within the serpentinizing system, was dominated by several bacterial taxa from the phyla OD1 ('Parcubacteria') and Chloroflexi. Members of the GPS1 community had, for the most part, the smallest genomes reported for their respective taxa, and encoded only archaeal (A-type) ATP synthases or no ATP synthases at all. Furthermore, none of the members encoded respiration-related genes and some of the members also did not encode key biosynthesis-related genes. In contrast, BS5, fed by shallow water, appears to have a community driven by hydrogen metabolism and was dominated by a diverse group of Proteobacteria similar to those seen in many terrestrial serpentinization sites. Our findings indicated that the harsh ultrabasic geological setting supported unexpectedly diverse microbial metabolic strategies and that the deep-water-fed springs supported a community that was remarkable in its unusual metagenomic and genomic constitution.

Landslides and liquefaction triggered by the M 7.9 denali fault earthquake of 3 November 2002

USGS Publications Warehouse

Harp, E.L.; Jibson, R.W.; Kayen, R.E.; Keefer, D.K.; Sherrod, B.L.; Carver, G.A.; Collins, B.D.; Moss, R.E.S.; Sitar, N.

2003-01-01

The moment magnitude (M) 7.9 Denali Fault earthquake in Alaska of 3 November 2002 triggered an unusual pattern of landslides and liquefaction effects. The landslides were primarily rock falls and rock slides that ranged in volume from a few cubic meters to the 40 million-cubic-meter rock avalanche that covered much of the McGinnis Glacier. Landslides were concentrated in a narrow zone ???30 km wide that straddled the fault rupture zone over its entire 300 km length. Large rock avalanches all clustered at the western end of the rupture zone where acceleration levels are reported to have been the highest. Liquefaction effects, consisting of sand blows, lateral spreads, and settlement, were widespread within susceptible alluvial deposits extending from Fairbanks eastward several hundred kilometers. The liquefaction effects displayed a pattern of increasing concentration and severity from west to east and extended well beyond the zone of landslides, which is unusual. The contrasting patterns formed by the distributions of landslides and liquefaction effects initially seemed to be inconsistent; however, preliminary analyses of strong-motion records from the earthquake offer a possible explanation for the unusual ground-failure patterns that are related to three subevents that have been discerned from the earthquake records.

36Cl: A tracer in groundwater in the aquia formation of Southern Maryland

USGS Publications Warehouse

Purdy, C.B.; Mignerey, A.C.; Helz, G.R.; Drummond, D.D.; Kubik, P.W.; Elmore, D.; Hemmick, T.

1987-01-01

The Aquia Formation (Paleocene) of Southern Maryland, a marine unit consisting predominantly of quartz sands, but containing 20-40% glauconite, represents one of the many productive, heavily pumped aquifers of the Southeastern Coastal Plain. An unusually high 36Cl activity ( ~ 15 ?? modem water) measured in an outcrop sample is interpreted as a result of the bomb pulse input. About 25 km downdip from the recharge area, a minimum in total chloride concentration occurs. This minimum is thought to correlate with the latest low-stand of sea-level, and thus to provide time information which is in general agreement with ages calculated from hydrodynamic data. However, significant increases in the 36Cl concentrations are observed along the flow path which may be due to ion filtration or to leakage of modem, bomb-contaminated water into the Aquia aquifer. ?? 1987.

Simultaneous concentration and purification through gradient deformation chromatography

NASA Technical Reports Server (NTRS)

Velayudhan, A.; Hendrickson, R. L.; Ladisch, M. R.; Mitchell, C. A. (Principal Investigator)

1995-01-01

Mobile-phase additives, commonly used to modulate absorbate retention in gradient elution chromatography, are usually assumed to be either linearly retained or unretained. Previous theoretical work from our laboratory has shown that these modulators, such as salts in ion-exchange and hydrophobic interaction chromatography and organic modifiers in reversed-phase chromatography, can absorb nonlinearly, giving rise to gradient deformation. Consequently, adsorbate peaks that elute in the vicinity of the head of the deformed gradient may exhibit unusual shapes, form shoulders, and/or be concentrated. These effects for a reversed-phase sorbent with aqueous acetonitrile (ACN) as the modulator are verified experimentally. Gradient deformation is demonstrated experimentally and agrees with simulations based on ACN isotherm parameters that are independently determined from batch equilibrium studies using the layer model. Unusual absorbate peak shapes were found experimentally for single-component injections of phenylalanine, similar to those calculated by the simulations. A binary mixture of tryptophan and phenylalanine is used to demonstrate simultaneous concentration and separation, again in agreement with simulations. The possibility of gradient deformation in ion-exchange and hydrophobic interaction chromatography is discussed.

Fire-extinguishing organic electrolytes for safe batteries

NASA Astrophysics Data System (ADS)

Wang, Jianhui; Yamada, Yuki; Sodeyama, Keitaro; Watanabe, Eriko; Takada, Koji; Tateyama, Yoshitaka; Yamada, Atsuo

2018-01-01

Severe safety concerns are impeding the large-scale employment of lithium/sodium batteries. Conventional electrolytes are highly flammable and volatile, which may cause catastrophic fires or explosions. Efforts to introduce flame-retardant solvents into the electrolytes have generally resulted in compromised battery performance because those solvents do not suitably passivate carbonaceous anodes. Here we report a salt-concentrated electrolyte design to resolve this dilemma via the spontaneous formation of a robust inorganic passivation film on the anode. We demonstrate that a concentrated electrolyte using a salt and a popular flame-retardant solvent (trimethyl phosphate), without any additives or soft binders, allows stable charge-discharge cycling of both hard-carbon and graphite anodes for more than 1,000 cycles (over one year) with negligible degradation; this performance is comparable or superior to that of conventional flammable carbonate electrolytes. The unusual passivation character of the concentrated electrolyte coupled with its fire-extinguishing property contributes to developing safe and long-lasting batteries, unlocking the limit toward development of much higher energy-density batteries.

Analysis of TES Satellite Ozone Observations from 2005 to 2013 to Understand Global Air Pollution Transport

NASA Astrophysics Data System (ADS)

Kladar, R. M.; Cooper, O. R.

2015-12-01

To better understand the causes of ozone formation and transport, we create and analyze global satellite ozone retrieval products for ground level to upper tropospheric ozone concentrations over the years 2005 to 2013 using the Tropospheric Emission Spectrometer (TES) that rides aboard the NASA Aura satellite. Many global and regional tropospheric ozone trends are not fully understood. Observing many different pressure levels between 1000 hPa to 215 hPa, we focus on the areas where model and other observation strategies disagree, namely the Arabian Peninsula, the Australian outback, and the southern Sahara. We observe (and these areas may be experiencing) unusually high ozone concentrations. We also comment on the historically high ozone areas such as China, Northern India, western Europe, and the western and southern United States and how known phenomena compare to our observations. Many observations confirm known mechanisms of ozone formation and transport, such as the effect of the yearly monsoon cycle in South, Southeast, and East Asia. Others, such as the surprisingly high monthly average concentrations on the Arabian Peninsula and Southern Sahara, deserve more thorough investigation. Several hypotheses for these disagreement areas are put forward here. Lastly, we comment on the usefulness of the TES instrument for trends analysis and future global observations.

Dissolved gasesous hydrocarbons in shallow groundwater of Lower Saxony, Germany - Revisited 2016

NASA Astrophysics Data System (ADS)

Schloemer, Stefan; Illing, Christian J.; Blumenberg, Martin; Oest, Johanna; Elbracht, Jörg

2017-04-01

Many concerns arise within the public and government/political institutions over potential groundwater contamination from deep drilling operations. For this reason we initiated a baseline study in 2014 on the distribution of dissolved methane, ethane and propane in shallow groundwater ( 1000 groundwater wells, Schloemer et al., 2016) of Lower Saxony, which includes the major petroleum and natural gas provinces in Germany. We observed a variation of dissolved methane concentration over 7 orders of magnitude (20 nl/l to 60 ml/l [v/v]). Methane delta13C compositions ranged from -110‰ to +25‰ vs VPDB, narrowly clustering around -70‰ at high concentrations but being increasingly more variable at lower concentrations (-40‰ to -80‰)). Most of the data are clearly indicative for methanogenic processes, samples unusually enriched in delta13C can best be explained by secondary methane oxidation. Although some general regional trend can be observed, results are highly variable within short lateral distances or within different aquifers/filter depths. Frequently ethane (27% of samples, median 50nl/l) and occasionally propane (8%, median 23nl/l) has been detected. Lacking the carbon isotope composition of these homologues and thus solely based on the extremely low concentrations and atypical ethane/propane ratios, these have been tentatively interpreted as ubiquitous microbial background. From the original 2014 sample set around 100 wells have been selected for consecutive testing through 2015. In spring 2016 a total number of 1100 wells have been sampled, 700 of which had already been part of the initial study, providing us with the unique opportunity to assess long term variations. The overall comparison of these 700 samples revealed only small relative variations in methane concentrations (mostly < ± 25%), although higher variations are common at concentrations less than 1 µl/l. Correspondingly the carbon isotopic composition of paired samples is quite stable (± 2‰)) for most of the samples ( 60%) but large discrepancies can be observed at low absolute concentrations (> ± 5‰ in 25% of samples). Minor variations could be related to uncertainties in laboratory analysis (± 10% in concentration, ± 0.5‰ delta13C). To which extent the small number of sampled groundwater with unusually high variations are indeed a result of a naturally occurring process (rapidly changing conditions or anthropogenic influence) is currently under investigation. However, applying different sampling conditions/procedures (i.e. different pumps, flow rates) had to be accepted during the course of the project and might be a reason as well. In any case our preliminary results point toward the necessity of repeated sampling (particularly in shallow unconfined aquifers) to account for possible natural variations and of strictly consistent sampling protocols when analyzing "non-conservative" dissolved gases. Reference Schloemer, S., Elbracht, J., Blumenberg, M. and Illing, C.J., 2016. Distribution and origin of dissolved methane, ethane and propane in shallow groundwater of Lower Saxony, Germany. Applied Geochemistry, 67: 118-132.

Origin of unusual HREE-Mo-rich carbonatites in the Qinling orogen, China

PubMed Central

Song, Wenlei; Xu, Cheng; Smith, Martin P.; Kynicky, Jindrich; Huang, Kangjun; Wei, Chunwan; Zhou, Li; Shu, Qihai

2016-01-01

Carbonatites, usually occurring within intra-continental rift-related settings, have strong light rare earth element (LREE) enrichment; they rarely contain economic heavy REE (HREE). Here, we report the identification of Late Triassic HREE-Mo-rich carbonatites in the northernmost Qinling orogen. The rocks contain abundant primary HREE minerals and molybdenite. Calcite-hosted fluid inclusions, inferred to represent a magmatic-derived aqueous fluid phase, contain significant concentrations of Mo (~17 ppm), reinforcing the inference that these carbonatitic magmas had high Mo concentrations. By contrast, Late Triassic carbonatites in southernmost Qinling have economic LREE concentrations, but are depleted in HREE and Mo. Both of these carbonatite types have low δ26Mg values (−1.89 to −1.07‰), similar to sedimentary carbonates, suggesting a recycled sediment contribution for REE enrichment in their mantle sources. We propose that the carbonatites in the Qinling orogen were formed, at least in part, by the melting of a subducted carbonate-bearing slab, and that 10 Ma younger carbonatite magmas in the northernmost Qinling metasomatized the thickened eclogitic lower crust to produce high levels of HREE and Mo. PMID:27857170

Enhancing multiphoton upconversion through energy clustering at sublattice level

NASA Astrophysics Data System (ADS)

Wang, Juan; Deng, Renren; MacDonald, Mark A.; Chen, Bolei; Yuan, Jikang; Wang, Feng; Chi, Dongzhi; Andy Hor, Tzi Sum; Zhang, Peng; Liu, Guokui; Han, Yu; Liu, Xiaogang

2014-02-01

The applications of lanthanide-doped upconversionnanocrystals in biological imaging, photonics, photovoltaics and therapeutics have fuelled a growing demand for rational control over the emission profiles of the nanocrystals. A common strategy for tuning upconversion luminescence is to control the doping concentration of lanthanide ions. However, the phenomenon of concentration quenching of the excited state at high doping levels poses a significant constraint. Thus, the lanthanide ions have to be stringently kept at relatively low concentrations to minimize luminescence quenching. Here we describe a new class of upconversion nanocrystals adopting an orthorhombic crystallographic structure in which the lanthanide ions are distributed in arrays of tetrad clusters. Importantly, this unique arrangement enables the preservation of excitation energy within the sublattice domain and effectively minimizes the migration of excitation energy to defects, even in stoichiometric compounds with a high Yb3+ content (calculated as 98 mol%). This allows us to generate an unusual four-photon-promoted violet upconversion emission from Er3+ with an intensity that is more than eight times higher than previously reported. Our results highlight that the approach to enhancing upconversion through energy clustering at the sublattice level may provide new opportunities for light-triggered biological reactions and photodynamic therapy.

Evidence of Anomalously Low δ13C of Marine Organic Matter in an Arctic Fjord.

PubMed

Kumar, Vikash; Tiwari, Manish; Nagoji, Siddhesh; Tripathi, Shubham

2016-11-09

Accurate estimation of relative carbon deposition (marine vs. terrestrial) is required for understanding the global carbon budget, particularly in the Arctic region, which holds disproportionate importance with respect to global carbon cycling. Although the sedimentary organic matter (SOM) concentration and its isotopic composition are important tools for such calculations, uncertainties loom over estimates provided by organic-geochemical bulk parameters. We report carbon and nitrogen concentrations and isotopes (δ 13 C and δ 15 N) of SOM at an Arctic fjord namely Kongsfjorden. We find that the bound inorganic nitrogen (ammonium attached to the clay minerals) forms a significant proportion of total nitrogen concentration (~77% in the inner fjord to ~24% in the outer part). On removing the bound nitrogen, the C/N ratio shows that the SOM in the inner fjord is made up of terrestrial carbon while the outer fjord shows mixed marine-terrestrial signal. We further show that the marine organic matter is unusually more depleted in 13 C (~-24‰) than the terrestrial organic matter (~-22.5‰). This particular finding also helps explain high δ 13 C values of SOM as noted by earlier studies in central Arctic sediments despite a high terrestrial contribution.

Structure and dynamics of propylammonium nitrate-acetonitrile mixtures: An intricate multi-scale system probed with experimental and theoretical techniques.

PubMed

Campetella, Marco; Mariani, Alessandro; Sadun, Claudia; Wu, Boning; Castner, Edward W; Gontrani, Lorenzo

2018-04-07

In this article, we report the study of structural and dynamical properties for a series of acetonitrile/propylammonium nitrate mixtures as a function of their composition. These systems display an unusual increase in intensity in their X-ray diffraction patterns in the low-q regime, and their 1 H-NMR diffusion-ordered NMR spectroscopy (DOSY) spectra display unusual diffusivities. However, the magnitude of both phenomena for mixtures of propylammonium nitrate is smaller than those observed for ethylammonium nitrate mixtures with the same cosolvent, suggesting that the cation alkyl tail plays an important role in these observations. The experimental X-ray scattering data are compared with the results of molecular dynamics simulations, including both ab initio studies used to interpret short-range interactions and classical simulations to describe longer range interactions. The higher level calculations highlight the presence of a strong hydrogen bond network within the ionic liquid, only slightly perturbed even at high acetonitrile concentration. These strong interactions lead to the symmetry breaking of the NO 3 - vibrations, with a splitting of about 88 cm -1 in the ν 3 antisymmetric stretch. The classical force field simulations use a greater number of ion pairs, but are not capable of fully describing the longest range interactions, although they do successfully account for the observed concentration trend, and the analysis of the models confirms the nano-inhomogeneity of these kinds of samples.

Structure and dynamics of propylammonium nitrate-acetonitrile mixtures: An intricate multi-scale system probed with experimental and theoretical techniques

NASA Astrophysics Data System (ADS)

Campetella, Marco; Mariani, Alessandro; Sadun, Claudia; Wu, Boning; Castner, Edward W.; Gontrani, Lorenzo

2018-04-01

In this article, we report the study of structural and dynamical properties for a series of acetonitrile/propylammonium nitrate mixtures as a function of their composition. These systems display an unusual increase in intensity in their X-ray diffraction patterns in the low-q regime, and their 1H-NMR diffusion-ordered NMR spectroscopy (DOSY) spectra display unusual diffusivities. However, the magnitude of both phenomena for mixtures of propylammonium nitrate is smaller than those observed for ethylammonium nitrate mixtures with the same cosolvent, suggesting that the cation alkyl tail plays an important role in these observations. The experimental X-ray scattering data are compared with the results of molecular dynamics simulations, including both ab initio studies used to interpret short-range interactions and classical simulations to describe longer range interactions. The higher level calculations highlight the presence of a strong hydrogen bond network within the ionic liquid, only slightly perturbed even at high acetonitrile concentration. These strong interactions lead to the symmetry breaking of the NO3 - vibrations, with a splitting of about 88 cm-1 in the ν3 antisymmetric stretch. The classical force field simulations use a greater number of ion pairs, but are not capable of fully describing the longest range interactions, although they do successfully account for the observed concentration trend, and the analysis of the models confirms the nano-inhomogeneity of these kinds of samples.

A steadying effect of acoustic excitation on transitory stall

NASA Technical Reports Server (NTRS)

Zaman, K. B. M. Q.

1991-01-01

The effect of acoustic excitation on a class of separated flows with a transitional boundary layer at the point of separation is considered. Experimental results on the flow over airfoils, a two-dimensional backward-facing step, and through large angle conical diffusers are presented. In all cases, the separated flow undergoes large amplitude fluctuations, much of the energy being concentrated at unusually low frequencies. In each case, an appropriate high frequency acoustic excitation is found to be effective in reducing the fluctuations substantially. The effective excitation frequency scales on the initial boundary layer thickness and the effect is apparently achieved through acoustic tripping of the separating boundary layer.

The Myszkow porphyry copper-molybdenum deposit, Poland

USGS Publications Warehouse

Chaffee, M.A.; Eppinger, R.G.; Lason, K.; Slosarz, J.; Podemski, M.

1994-01-01

The porphyry copper-molybdenum deposit at Myszkow, south-central Poland, lies in the Cracow-Silesian orogenic belt, in the vicinity of a Paleozoic boundary between two tectonic plates. The deposit is hosted in a complex that includes early Paleozoic metasedimentary rocks intruded in the late Paleozoic by a predominantly granodioritic pluton. This deposit exhibits many features that are typical of porphyry copper deposits associated with calc-alkaline intrusive rocks, including ore- and alteration-mineral suites, zoning of ore and alteration minerals, fluid-inclusion chemistry, tectonic setting, and structural style of veining. Unusual features of the Myszkow deposit include high concentrations of tungsten and the late Paleozoic (Variscan) age. -Authors

A rapid method to visualize von willebrand factor multimers by using agarose gel electrophoresis, immunolocalization and luminographic detection.

PubMed

Krizek, D R; Rick, M E

2000-03-15

A highly sensitive and rapid clinical method for the visualization of the multimeric structure of von Willebrand Factor in plasma and platelets is described. The method utilizes submerged horizontal agarose gel electrophoresis, followed by transfer of the von Willebrand Factor onto a polyvinylidine fluoride membrane, and immunolocalization and luminographic visualization of the von Willebrand Factor multimeric pattern. This method distinguishes type 1 from types 2A and 2B von Willebrand disease, allowing timely evaluation and classification of von Willebrand Factor in patient plasma. It also allows visualization of the unusually high molecular weight multimers present in platelets. There are several major advantages to this method including rapid processing, simplicity of gel preparation, high sensitivity to low concentrations of von Willebrand Factor, and elimination of radioactivity.

Continuous transport of Pacific-derived anthropogenic radionuclides towards the Indian Ocean

PubMed Central

Pittauer, Daniela; Tims, Stephen G.; Froehlich, Michaela B.; Fifield, L. Keith; Wallner, Anton; McNeil, Steven D.; Fischer, Helmut W.

2017-01-01

Unusually high concentrations of americium and plutonium have been observed in a sediment core collected from the eastern Lombok Basin between Sumba and Sumbawa Islands in the Indonesian Archipelago. Gamma spectrometry and accelerator mass spectrometry data together with radiometric dating of the core provide a high-resolution record of ongoing deposition of anthropogenic radionuclides. A plutonium signature characteristic of the Pacific Proving Grounds (PPG) dominates in the first two decades after the start of the high yield atmospheric tests in 1950’s. Approximately 40–70% of plutonium at this site in the post 1970 period originates from the PPG. This sediment record of transuranic isotopes deposition over the last 55 years provides evidence for the continuous long-distance transport of particle-reactive radionuclides from the Pacific Ocean towards the Indian Ocean. PMID:28304374

Unusual calcite cementing of quartz grains on Chandeleur Island Beach, offshore Louisiana

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mitchell-Tapping, H.J.

1983-09-01

A very unusual calcite cement was found in some beachchips from an unconsolidated beach surface of Chandeleur Island offshore approximately 35 nmi (65 km) south of Mississippi in the Gulf of Mexico. The beachchips are irregularly shaped and are well cemented by this unusual calcite. This calcite crystal structure has not been reported previously as existing in a marine environment. A similar cement has been found in freshwater lake beachrock and in some travertine samples. The calcite crystals are elongate parallel to the c-optic axis, and are composed of bunches of crystallite blades. The crystallite blades of each crystal bunchmore » are pointed and are more bladed than freshwater cement crystals. The intercrystallite pore space contains no fine calcite silt as was observed in the lake samples. Fresh water provided by rainfall may be held in the pore spaces and bounded to the quartz-grain surfaces by ionic attraction. Marine spray above and saline water concentrated underneath from a sandwich effect at the micropore level, allowing rapid growth and precipitation of these very unusual calcite crystals in a single-phase low-salinity fluid.« less

Factors controlling As and U in shallow ground water, southern Carson Desert, Nevada

USGS Publications Warehouse

Welch, A.H.; Lico, M.S.

1998-01-01

Unusually high As and U concentrations (> 100 ??g/L) are widespread in shallow ground water beneath the southern Carson Desert. The high concentrations, which locally exceed 1000 ??g/L, are of concern from a human health standpoint because the shallow ground water is used for domestic supply. Possible affects on wildlife are also of concern because the ground water flows into shallow lakes and marshes within wildlife refuges. Arsenic and U concentrations in ground water of the southern Carson Desert appear to be affected by evaporative concentration, redox reactions, and adsorption. The relation of these elements with Cl suggest that most of the high concentrations can be attributed to evaporative concentration of Carson River water, the primary source of recharge. Some ground water contains higher As and U concentrations that cannot be explained by evaporative concentration alone. Oxidation-reduction reactions, involving metal oxides and sedimentary-organic matter, appear to contribute As, U, inorganic C, Fe and Mn to the ground water. Arsenic in Fe-oxide was confirmed by chemical extraction and is consistent with laboratory adsorption studies. Uranium in both sedimentary-organic C and Fe-oxide coatings has been confirmed by fission tracks and petrographic examination. Arsenic concentrations in the ground water and chemical extracts of aquifer sediments are broadly consistent with adsorption as a control on some dissolved As concentrations. An apparent loss of As from some ground water as evaporative concentration proceeds is consistent with adsorption as a control on As. However, evidence for adsorption should be viewed with caution, because the adsorption model used values for the adsorbent that have not been shown to be valid for the aquifer sediments throughout the southern Carson Desert. Hydrologic and geochemical conditions in the Carson Desert are similar to other areas with high As and U concentrations in ground water, including the Salton Sea basin and southern San Joaquin Valley of California. Hydrologic and geochemical conditions that produced some sandstone-tyPe U-ore deposits, including those in the non-marine, closed-basin sediments of the Morrison Formation near Grants, New Mexico, suggest that the Carson Desert may be a modern analog for those systems.

Intercostal muscle twitching: An unusual manifestation of extracardiac stimulation related to right ventricular outflow tract pacing

PubMed Central

Erdogan, Okan

2007-01-01

The present case report describes a patient who underwent successful dual-chamber pacemaker implantation with active ventricular lead fixation at a high septal region in the right ventricular outflow tract. Unexpectedly, stimulation at a high output in the right ventricular outflow tract caused an unusual extracardiac stimulation, specifically, intercostal muscle twitching. PMID:17703261

Solar astrophysics - Ghettosis from, or symbiosis with, stellar and galactic astrophysics

NASA Technical Reports Server (NTRS)

Pecker, J.-C.; Thomas, R. N.

1976-01-01

The purpose of the paper is to show how the solar-stellar symbiotic approach has led to the modeling of a star as a concentration of matter and energy. By 'solar-stellar symbiosis' is meant the philosophy of investigation according to which one asks what change in our general understanding of stellar structure and of stellar spectroscopic diagnostics is required to satisfy both the sun and an unusual star when, for example, some feature of an unusual star is discovered. The evolution of stellar models is traced, from walled, thermodynamic-equilibrium models to de-isolated models featuring transition zones and nonlocal thermodynamic equilibrium.

A blood survey of elements, viral antibodies, and hemoparasites in wintering Harlequin Ducks (Histrionicus histrionicus) and Barrow's Goldeneyes (Bucephala islandica)

USGS Publications Warehouse

Heard, D.J.; Mulcahy, D.M.; Iverson, S.A.; Rizzolo, D.J.; Greiner, E.C.; Hall, J.; Ip, Hon S.; Esler, Daniel N.

2008-01-01

Twenty-eight Harlequin Ducks (Histrionicus histrionicus) and 26 Barrow's Goldeneyes (Bucephala islandica) were captured in Prince William Sound, Alaska, between 1 and 15 March 2005. Blood was collected for quantification of element concentrations, prevalence of antibodies to several viruses, and hemoparasite prevalence and identification. Although we found selenium concentrations that have been associated with selenosis in some birds (???.0 ppm ww), our findings contribute to a growing literature describing relatively high selenium in apparently healthy birds in marine environments. Avian influenza virus antibodies were detected in the plasma of 28% of the ducks. No antibodies against adenovirus, reovirus, or paramyxovirus 1 were detected. Several hemoparasite species were identified in 7% of ducks. Our findings are similar to those in other free-living marine waterfowl and do not indicate unusual concerns for the health of these species in this area in late winter. ?? Wildlife Disease Association 2008.

A blood survey of elements, viral antibodies, and hemoparasites in wintering Harlequin Ducks (Histrionicus histrionicus) and Barrow's Goldeneyes (Bucephala islandica).

PubMed

Heard, Darryl J; Mulcahy, Daniel M; Iverson, Samuel A; Rizzolo, Daniel J; Greiner, Ellis C; Hall, Jeff; Ip, Hon; Esler, Daniel

2008-04-01

Twenty-eight Harlequin Ducks (Histrionicus histrionicus) and 26 Barrow's Goldeneyes (Bucephala islandica) were captured in Prince William Sound, Alaska, between 1 and 15 March 2005. Blood was collected for quantification of element concentrations, prevalence of antibodies to several viruses, and hemoparasite prevalence and identification. Although we found selenium concentrations that have been associated with selenosis in some birds (>or=2.0 ppm ww), our findings contribute to a growing literature describing relatively high selenium in apparently healthy birds in marine environments. Avian influenza virus antibodies were detected in the plasma of 28% of the ducks. No antibodies against adenovirus, reovirus, or paramyxovirus 1 were detected. Several hemo-parasite species were identified in 7% of ducks. Our findings are similar to those in other free-living marine waterfowl and do not indicate unusual concerns for the health of these species in this area in late winter.

Mercury dilution by autochthonous organic matter in a fertilized mangrove wetland.

PubMed

Machado, Wilson; Sanders, Christian J; Santos, Isaac R; Sanders, Luciana M; Silva-Filho, Emmanoel V; Luiz-Silva, Wanilson

2016-06-01

A dated sediment core from a highly-fertilized mangrove wetland located in Cubatão (SE Brazil) presented a negative correlation between mercury (Hg) and organic carbon contents. This is an unusual result for a metal with well-known affinity to organic matter. A dilution of Hg concentrations by autochthonous organic matter explained this observation, as revealed by carbon stable isotopes signatures (δ(13)C). Mercury dilution by the predominant mangrove-derived organic matter counterbalanced the positive influences of algal-derived organic matter and clay contents on Hg levels, suggesting that deleterious effects of Hg may be attenuated. Considering the current paradigm on the positive effect of organic matter on Hg concentrations in coastal sediments and the expected increase in mangrove organic matter burial due to natural and anthropogenic stimulations of primary production, predictions on the influences of organic matter on Hg accumulation in mangrove wetlands deserve caution. Copyright © 2016 Elsevier Ltd. All rights reserved.

Fate, bioavailability and toxicity of silver in estuarine environments

USGS Publications Warehouse

Luoma, S.N.; Ho, Y.B.; Bryan, G.W.

1995-01-01

The chemistry and bioavailability of Ag contribute to its high toxicity in marine and estuarine waters. Silver is unusual, in that both the dominant speciation reaction in seawater and the processes important in sorbing Ag in sediments favour enhanced bioavailability. Formation of a stable chloro complex favours dispersal of dissolved Ag, and the abundant chloro complex is available to biota. Sequestration by sediments also occurs, but with relatively slow kinetics. Amorphous aggregated coatings enhance Ag accumulation in sediments, as well as Ag uptake from sediments by deposit feeders. In estuaries, the bioaccumulation of Ag increases 56-fold with each unit of increased Ag concentration in sediments. Toxicity for sensitive marine species occurs at absolute concentrations as low as those observed for any nonalkylated metal, partly because bioaccumulation increases so steeply with contamination. The environmental window of tolerance to Ag in estuaries could be narrower than for many elements.

Flower-like self-assembly of gold nanoparticles for highly sensitive electrochemical detection of chromium(VI)

PubMed Central

Ouyang, Ruizhuo; Bragg, Stefanie A.; Chambers, James Q.; Xue, Zi-Ling

2012-01-01

We report here the fabrication of a flower-like self-assembly of gold nanoparticles (AuNPs) on a glassy carbon electrode (GCE) as a highly sensitive platform for ultratrace Cr(VI) detection. Two AuNPs layers are used in the current approach, in which the first is electroplated on the GCE surface as anchors for binding to an overcoated thiol sol-gel film derived from 3-mercaptopropyltrimethoxysilane (MPTS). The second AuNPs layer is then self-assembled on the surface of the sol-gel film, forming flower-like gold nanoelectrodes enlarging the electrode surface. When functionalized by a thiol pyridinium, the fabricated electrode displays a well-defined peak for selective Cr(VI) reduction with an unusually large, linear concentration range of 10–1,200 ng L−1 and a low detection limit of 2.9 ng L−1. In comparison to previous approaches using MPTS and AuNPs on Au electrodes, the current work expands the use of AuNPs to the GCE. Subsequent functionalization of the secondary AuNPs by a thiol pyridinium and adsorption/preconcentration of Cr(VI) lead to the unusually large detection range and high sensitivity. The stepwise preparation of the electrode has been characterized by electrochemical impedance spectroscopy (EIS), scanning electronic microscopy (SEM), and IR. The newly designed electrode exhibits good stability, and has been successfully employed to measure chromium in a pre-treated blood sample. The method demonstrates acceptable fabrication reproducibility and accuracy. PMID:22444528

Observations of high droplet number concentrations in Southern Ocean boundary layer clouds

NASA Astrophysics Data System (ADS)

Chubb, T.; Huang, Y.; Jensen, J.; Campos, T.; Siems, S.; Manton, M.

2015-09-01

Data from the standard cloud physics payload during the NSF/NCAR High-performance Instrumented Airborne Platform for Environmental Research (HIAPER) Pole-to-Pole Observations (HIPPO) campaigns provide a snapshot of unusual wintertime microphysical conditions in the boundary layer over the Southern Ocean. On 29 June 2011, the HIAPER sampled the boundary layer in a region of pre-frontal warm air advection between 58 and 48° S to the south of Tasmania. Cloud droplet number concentrations were consistent with climatological values in the northernmost profiles but were exceptionally high for wintertime in the Southern Ocean at 100-200 cm-3 in the southernmost profiles. Sub-micron (0.0625 m s-1) were most likely responsible for production of sea spray aerosol which influenced the microphysical properties of the boundary layer clouds. The smaller size and higher number concentration of cloud droplets is inferred to increase the albedo of these clouds, and these conditions occur regularly, and are expected to increase in frequency, over windy parts of the Southern Ocean.

Unexpectedly high bacteriochlorophyll a concentrations in neotropical tank bromeliads.

PubMed

Lehours, Anne-Catherine; Jeune, Anne-Hélène Le; Aguer, Jean-Pierre; Céréghino, Régis; Corbara, Bruno; Kéraval, Benoit; Leroy, Céline; Perrière, Fanny; Jeanthon, Christian; Carrias, Jean-François

2016-06-06

The contribution of bacteriochlorophyll a (BChl a) to photosynthetically driven electron transport is generally low in aquatic and terrestrial systems. Here, we provide evidence that anoxygenic bacterial phototrophy is widespread and substantial in water retained by tank bromeliads of a primary rainforest in French Guiana. An analysis of the water extracted from 104 randomly selected tank bromeliads using infrared fluorimetry suggested the overall presence of abundant anoxygenic phototrophic bacterial populations. We found that purple bacteria dominated these populations responsible for unusually high BChl a/chlorophyll a ratios (>50%). Our data suggest that BChl a-based phototrophy in tank bromeliads can have significant effects on the ecology of tank-bromeliad ecosystems and on the carbon and energy fluxes in Neotropical forests. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

Growth strategies to control tapering in Ge nanowires

NASA Astrophysics Data System (ADS)

Periwal, P.; Baron, T.; Gentile, P.; Salem, B.; Bassani, F.

2014-04-01

We report the effect of PH3 on the morphology of Au catalyzed Ge nanowires (NWs). Ge NWs were grown on Si (111) substrate at 400 °C in the presence of PH3, using vapor-liquid-solid method by chemical vapor deposition. We show that high PH3/GeH4 ratio causes passivation at NW surface. At high PH3 concentration phosphorous atoms attach itself on NW surface and form a self-protection coating that prevents conformal growth and leads to taper free nanostructures. However, in case of low PH3 flux the combination of axial and radial growth mechanism occurs resulting in conical structure. We have also investigated axial PH3-intrinsic junctions in Ge NWs. The unusual NW shape is attributed to a combination of catalyzed, uncatalyzed and diffusion induced growth.

Effects of disordered Ru substitution in BaFe2As2: possible realization of superdiffusion in real materials.

PubMed

Wang, Limin; Berlijn, Tom; Wang, Yan; Lin, Chia-Hui; Hirschfeld, P J; Ku, Wei

2013-01-18

An unexpected insensitivity of the Fermi surface to impurity scattering is found in Ru substituted BaFe(2)As(2) from first-principles theory, offering a natural explanation of the unusual resilience of transport and superconductivity to a high level of disordered substitution in this material. This robustness is shown to originate from a coherent interference of correlated on-site and intersite impurity scattering, similar in spirit to the microscopic mechanism of superdiffusion in one dimension. Our result also demonstrates a strong substitution dependence of the Fermi surface and carrier concentration and provides a resolution to current discrepancies in recent photoelectron spectroscopy. These effects offer a natural explanation of the diminishing long-range magnetic, orbital, and superconducting orders with high substitution.

Selenium exposure in subjects living in areas with high selenium concentrated drinking water: results of a French integrated exposure assessment survey.

PubMed

Emmanuelle, Barron; Virginie, Migeot; Fabienne, Séby; Isabelle, Ingrand; Martine, Potin-Gautier; Bernard, Legube; Sylvie, Rabouan

2012-04-01

Selenium is an essential element which can be toxic if ingested in excessive quantities. The main human exposure is food. In addition, intake may be boosted by consumption drinking water containing unusual high selenium concentration. We measured the individual selenium level of people exposed to selenium concentration in drinking water greater than the maximum recommended limit which is 10 μg/L. We carried out a prospective cohort study on 80 adults (40 exposed subjects i.e. living in the involved area and 40 non-exposed ones i.e. living elsewhere) in western France. We used three different approaches: (1) direct measurement of ingested selenium by the duplicate portion method, (2) dietary reconstitution with a food frequency questionnaire (FFQ) and (3) evaluation of the individual selenium status by measuring the selenium content in toenail clippings. Analyses were performed by inductively coupled plasma-mass spectrometry. The association between toenail selenium concentration and area of residence was analyzed using linear regression with repeated measurements. We estimated selenium intake from FFQ at 64±14 μg/day for exposed subjects as opposed to 52±14 μg/day for the non-exposed ones. On the basis of 305 duplicate diet samples, average intake was estimated at 64±26 μg/day for exposed subjects. Area of residence (p=0.0030) and smoking (p=0.0054) were independently associated with toenail selenium concentration. Whatever method used for estimating selenium intake, the selenium level in this studied area with high selenium concentrated drinking water is much lower than in seleniferous areas. Copyright © 2011 Elsevier Ltd. All rights reserved.

The nature, distribution and genesis of the coesite and stishovite associated with the pseudotachylite of the Vredefort Dome, South Africa

NASA Astrophysics Data System (ADS)

Martini, J. E. J.

1991-04-01

The Vredefort Dome represents the uplift centre of a well known 2.00 Ga old impact structure of unusually large magnitude. Shock features like shatter cones, planar features and high-pressure silica polymorphs are common. The present study deals with the description, mode of occurrence, field distribution and post-shock metamorphic alteration of coesite and stishovite which were poorly documented up to now. These minerals occur as unusually large crystals in the quartzite of the wall rock in contact with very thin pseudotachylite veins. In the pseudotachylite itself, which can be interpreted as a friction and/or a shock recovery melt, fine needles of kyanite are ubiquitous. It is proposed that these thin pseudotachylites (A-type) formed during the transit of the shock wave. They preceded the development of thick pseudotachylite and microbreccia veins (B-type) which formed during the tensional period which immediately followed. From comparison with the model of formation of high-pressure polymorphs in porous sandstone, it is suggested that higher pressure and stress was concentrated along the A-type veins at the arrival of the shock front. At this time the quartz was transformed into a "high-pressure phase" which was probably poorly crystalline. Behind the shock front, that is during the rarefaction, the pressure was progressively released and the polymorphs crystallized from this initial "high-pressure phase". Stishovite crystallized first, followed by coesite. The high-pressure conditions may have lasted an unusually long time due to the magnitude of the Vredefort impact. This long time, probably about one second, may account for the large size of the coesite and stishovite crystals. Most of the high-pressure silica polymorphs are corroded to a variable degree by secondary quartz and preserved only in a restricted area of the impact structure. This alteration is attributed to post-shock metamorphism due to the temperature of the rock before impact plus the heat left after shock recovery. Some of the evidence put forward by authors against the impact model is discussed according to the facts arising from this investigation. It is concluded that an origin by impact remains the simplest and most realistic model to explain the origin of the Vredefort Dome.

Formal water oxidation turnover frequencies from MIL-101(Cr) anchored Ru(bda) depend on oxidant concentration.

PubMed

Bhunia, Asamanjoy; Johnson, Ben A; Czapla-Masztafiak, Joanna; Sá, Jacinto; Ott, Sascha

2018-06-21

The molecular water oxidation catalyst [Ru(bda)(L)2] has been incorporated into pyridine-decorated MIL-101(Cr) metal-organic frameworks. The resulting MIL-101@Ru materials exhibit turnover frequencies (TOFs) up to ten times higher compared to the homogenous reference. An unusual dependence of the formal TOFs on oxidant concentration is observed that ultimately arises from differing amounts of catalysts in the MOF crystals being active.

Nickel binding to NikA: an additional binding site reconciles spectroscopy, calorimetry and crystallography.

PubMed

Addy, Christine; Ohara, Masato; Kawai, Fumihiro; Kidera, Akinori; Ikeguchi, Mitsunori; Fuchigami, Sotaro; Osawa, Masanori; Shimada, Ichio; Park, Sam-Yong; Tame, Jeremy R H; Heddle, Jonathan G

2007-02-01

Intracellular nickel is required by Escherichia coli as a cofactor for a number of enzymes and is necessary for anaerobic respiration. However, high concentrations of nickel are toxic, so both import and export systems have evolved to control the cellular level of the metal. The nik operon in E. coli encodes a nickel-uptake system that includes the periplasmic nickel-binding protein NikA. The crystal structures of wild-type NikA both bound to nickel and in the apo form have been solved previously. The liganded structure appeared to show an unusual interaction between the nickel and the protein in which no direct bonds are formed. The highly unusual nickel coordination suggested by the crystal structure contrasted strongly with earlier X-ray spectroscopic studies. The known nickel-binding site has been probed by extensive mutagenesis and isothermal titration calorimetry and it has been found that even large numbers of disruptive mutations appear to have little effect on the nickel affinity. The crystal structure of a binding-site mutant with nickel bound has been solved and it is found that nickel is bound to two histidine residues at a position distant from the previously characterized binding site. This novel site immediately resolves the conflict between the crystal structures and other biophysical analyses. The physiological relevance of the two binding sites is discussed.

The projected demise of Barnes Ice Cap: Evidence of an unusually warm 21st century Arctic

NASA Astrophysics Data System (ADS)

Gilbert, A.; Flowers, G. E.; Miller, G. H.; Refsnider, K. A.; Young, N. E.; Radić, V.

2017-03-01

As a remnant of the Laurentide Ice Sheet, Barnes Ice Cap owes its existence and present form in part to the climate of the last glacial period. The ice cap has been sustained in the present interglacial climate by its own topography through the mass balance-elevation feedback. A coupled mass balance and ice-flow model, forced by Coupled Model Intercomparison Project Phase 5 climate model output, projects that the current ice cap will likely disappear in the next 300 years. For greenhouse gas Representative Concentration Pathways of +2.6 to +8.5 Wm-2, the projected ice-cap survival times range from 150 to 530 years. Measured concentrations of cosmogenic radionuclides 10Be, 26Al, and 14C at sites exposed near the ice-cap margin suggest the pending disappearance of Barnes Ice Cap is very unusual in the last million years. The data and models together point to an exceptionally warm 21st century Arctic climate.

The biogeochemistry and occurrence of unusual plant species inhabiting acidic, metal-rich water, Red Mountain, Bonnifield district, Alaska Range: Chapter J in Recent U.S. Geological Survey studies in the Tintina Gold Province, Alaska, United States, and Yukon, Canada--results of a 5-year project

USGS Publications Warehouse

Gough, Larry P.; Eppinger, Robert G.; Briggs, Paul H.

2007-01-01

This report presents results on the occurrence and biogeochemistry of unusual plant species, and of their supporting sediment, in an undisturbed volcanogenic massive sulfide deposit in the Tintina Gold Province (see fig. 1 of Editors’ Preface and Overview). The extraordinary plant assemblage found growing in the acidic metal-rich waters that drain the area is composed predominantly of bryophytes (liverworts and mosses). Ferricrete-cemented silty alluvial sediments within seeps and streams are covered with the liverwort Gymnocolea inflata, whereas the mosses Polytrichum commune and P. juniperinum inhabit the area adjacent to the water and within the splash zone. Both the liverwort-encrusted sediment and Polytrichum thalli have high concentrations of major- and trace-metal cations (for example, Al, As, Cu, Fe, Hg, La, Mn, Pb, and Zn). Soils in the area do not reflect the geochemical signature of the mineral deposit, and we suspect that they are most influenced by the chemistry of airborne dust (aeolian material) derived from outside the area.

THE BALMER-DOMINATED BOW SHOCK AND WIND NEBULA STRUCTURE OF {gamma}-RAY PULSAR PSR J1741-2054

DOE Office of Scientific and Technical Information (OSTI.GOV)

Romani, Roger W.; Shaw, Michael S.; Camilo, Fernando

2010-12-01

We have detected an H{alpha} bow shock nebula around PSR J1741-2054, a pulsar discovered through its GeV {gamma}-ray pulsations. The pulsar is only {approx}1.''5 behind the leading edge of the shock. Optical spectroscopy shows that the nebula is non-radiative, dominated by Balmer emission. The H{alpha} images and spectra suggest that the pulsar wind momentum is equatorially concentrated and implies a pulsar space velocity {approx}150 km s{sup -1}, directed 15{sup 0} {+-} 10{sup 0} out of the plane of the sky. The complex H{alpha} profile indicates that different portions of the post-shock flow dominate line emission as gas moves along themore » nebula and provide an opportunity to study the structure of this unusual slow non-radiative shock under a variety of conditions. CXO ACIS observations reveal an X-ray pulsar wind nebula within this nebula, with a compact {approx}2.''5 equatorial structure and a trail extending several arcminutes behind. Together these data support a close ({<=}0.5 kpc) distance, a spin geometry viewed edge-on, and highly efficient {gamma}-ray production for this unusual, energetic pulsar.« less

Chemical contamination of soils in the New York City area following Hurricane Sandy.

PubMed

Mandigo, Amy C; DiScenza, Dana J; Keimowitz, Alison R; Fitzgerald, Neil

2016-10-01

This paper presents a unique data set of lead, arsenic, polychlorinated biphenyl (PCB), and polycyclic aromatic hydrocarbon (PAH) concentrations in soil samples collected from the metropolitan New York City area in the aftermath of Hurricane Sandy. Initial samples were collected by citizen scientists recruited via social media, a relatively unusual approach for a sample collection project. Participants in the affected areas collected 63 usable samples from basements, gardens, roads, and beaches. Results indicate high levels of arsenic, lead, PCBs, and PAHs in an area approximately 800 feet south of the United States Environmental Protection Agency (US EPA) Superfund site at Newtown Creek. A location adjacent to the Gowanus Canal, another Superfund site, was found to have high PCB concentrations. Areas of high PAH contamination tended to be near high traffic areas or next to sites of known contamination. While contamination as a direct result of Hurricane Sandy cannot be demonstrated conclusively, the presence of high levels of contamination close to known contamination sites, evidence for co-contamination, and decrease in number of samples containing measureable amounts of semi-volatile compounds from samples collected at similar locations 9 months after the storm suggest that contaminated particles may have migrated to residential areas as a result of flooding.

The stress response to environmental change in captive cheetahs (Acinonyx jubatus).

PubMed

Wells, Amy; Terio, Karen A; Ziccardi, Michael H; Munson, Linda

2004-03-01

The captive North American cheetah (Acinonyx jubatus) population is not self-sustaining because of high prevalences of unusual diseases and poor reproductive success. Cheetahs are commonly moved between zoos for breeding purposes to maintain genetic diversity within the captive population, and movement may exacerbate infertility and disease. Fecal corticoids were analyzed by radioimmunoassay to measure the stress response of cheetahs to movement between facilities. Fecal samples were collected from 15 cheetahs for 14 days before movement and for at least 30 days after movement. For each cheetah, premovement fecal corticoid concentrations were used to determine baseline and then compared with trends in postmovement concentrations. In general, postmovement corticoid concentrations either increased (n = 8), did not change (n = 2), or decreased (n = 5). Although individual animal differences occurred, corticoid concentrations increased for most animals moved on-exhibit and decreased in animals moved off-exhibit. Animals moving on-exhibit had an 18-times greater risk of having corticoids elevated more than two standard deviations above baseline for 30 days after movement compared with animals that moved off-exhibit. In addition, greater day-to-day variation in corticoids occurred in animals moved on-exhibit. In general, animals with initially low baseline corticoid concentrations had a greater postmovement corticoid response than cheetahs with initially high baseline levels. These results indicate that some cheetahs have a prolonged stress response when moved between facilities, and the magnitude and character of this response is influenced by the exhibit environment.

Monthly variability and possible sources of nitrate in ground water beneath mixed agricultural land use, Suwannee and Lafayette Counties, Florida

USGS Publications Warehouse

Katz, Brian G.; Böhlke, J.K.

2000-01-01

In an area of mixed agricultural land use in Suwannee and Lafayette Counties of northern Florida, water samples were collected monthly from 14 wells tapping the Upper Floridan aquifer during July 1998 through June 1999 to assess hydrologic and land-use factors affecting the variability in nitrate concentrations in ground water. Unusually high amounts of rainfall in September and October 1998 (43.5 centimeters total for both months) resulted in an increase in water levels in all wells in October 1998. This was followed by unusually low amounts of rainfall during November 1998 through May 1999, when rainfall was 40.7 centimeters below 30-year mean monthly values. The presence of karst features (sinkholes, springs, solution conduits) and the highly permeable sands that overlie the Upper Floridan aquifer provide for rapid movement of water containing elevated nitrate concentrations to the aquifer. Nitrate was the dominant form of nitrogen in ground water collected at all sites and nitrate concentrations ranged from less than 0.02 to 22 milligrams per liter (mg/L), as nitrogen. Water samples from most wells showed substantial monthly or seasonal fluctuations in nitrate concentrations. Generally, water samples from wells with nitrate concentrations higher than 10 mg/L showed the greatest amount of monthly fluctuation. For example, water samples from six of eight wells had monthly nitrate concentrations that varied by at least 5 mg/L during the study period. Water from most wells with lower nitrate concentrations (less than 6 mg/L) also showed large monthly fluctuations. For instance, nitrate concentrations in water from four sites showed monthly variations of more than 50 percent. Large fluctuations in nitrate concentrations likely result from seasonal agricultural practices (fertilizer application and animal waste spreading) at a particular site. For example, an increase in nitrate concentrations observed in water samples from seven sites in February or March 1999 most likely results from application of synthetic fertilizers during the late winter months. Lower nitrate concentrations were detected in water samples from five of eight wells sampled during high-flow conditions for the Suwannee River in March 1998 compared to low-flow conditions in November 1998. Evidence for reduction of nitrate due to denitrification reactions was observed at one site (AC-1), as indicated by elevated concentrations of nitrogen gas and a corresponding increase in nitrogen isotope (d15N-NO3) values with a decrease in nitrate concentrations. Denitrification is unlikely at other sites based on the presence of dissolved oxygen concentrations greater than 2 mg/L in ground water and no observed trend between nitrate concentrations and values d15N-NO3 values. Nitrate was the dominant nitrogen species in most monthly rainfall samples; however, ammonium concentrations were similar or greater than nitrate during November and December 1998. During February through May 1999, both nitrate and ammonium concentrations were substantially higher in monthly rainfall samples collected at the study area compared to mean monthly concentrations at the Bradford Forest site located east of the study area, which is part of the National Atmospheric Deposition Program/National Trends Network. Also, higher nitrogen deposition rates in the study area compared to those at Bradford Forest could indicate that substantial amounts of ammonia are volatilized from fertilizers and animal wastes, released to the atmosphere, and incorporated as nitrate and ammonium in rainfall deposited in the middle Suwannee River Basin. Ground-water samples from most sites had d15N-NO3 values that indicated a mixture of inorganic and organic sources of nitrogen, which corresponded to multiple land uses where both synthetic fertilizers and manure are used on fields near these sites. Distinct d15N-NO3 signatures, however, were observed at some sites. For example, water samples from areas of row-crop farmin

Phase behaviour of disordered proteins underlying low density and high permeability of liquid organelles

NASA Astrophysics Data System (ADS)

Wei, Ming-Tzo; Elbaum-Garfinkle, Shana; Holehouse, Alex S.; Chen, Carlos Chih-Hsiung; Feric, Marina; Arnold, Craig B.; Priestley, Rodney D.; Pappu, Rohit V.; Brangwynne, Clifford P.

2017-11-01

Many intracellular membraneless organelles form via phase separation of intrinsically disordered proteins (IDPs) or regions (IDRs). These include the Caenorhabditis elegans protein LAF-1, which forms P granule-like droplets in vitro. However, the role of protein disorder in phase separation and the macromolecular organization within droplets remain elusive. Here, we utilize a novel technique, ultrafast-scanning fluorescence correlation spectroscopy, to measure the molecular interactions and full coexistence curves (binodals), which quantify the protein concentration within LAF-1 droplets. The binodals of LAF-1 and its IDR display a number of unusual features, including 'high concentration' binodal arms that correspond to remarkably dilute droplets. We find that LAF-1 and other in vitro and intracellular droplets are characterized by an effective mesh size of ∼3-8 nm, which determines the size scale at which droplet properties impact molecular diffusion and permeability. These findings reveal how specific IDPs can phase separate to form permeable, low-density (semi-dilute) liquids, whose structural features are likely to strongly impact biological function.

Robust cross-links in molluscan adhesive gels: Testing for contributions from hydrophobic and electrostatic interactions

PubMed Central

Smith, A.M.; Robinson, T. M.; Salt, M. D.; Hamilton, K. S.; Silvia, B. E.; Blasiak, R.

2009-01-01

The cross-linking interactions that provide cohesive strength to molluscan adhesive gels were investigated. Metal-based interactions have been shown to play an important role in the glue of the slug Arion subfuscus (Draparnaud), but other types of interactions may also contribute to the glue's strength and their role has not been investigated. This study shows that treatments that normally disrupt hydrophobic or electrostatic interactions have little to no effect on the slug glue. High salt concentrations and non-ionic detergent do not affect the solubility of the proteins in the glue or the ability of the glue proteins to stiffen gels. In contrast, metal chelation markedly disrupts the gel. Experiments with gel filtration chromatography identify a 40 kDa protein that is a central component of the cross-links in the glue. This 40 kDa protein forms robust macromolecular aggregations that are stable even in the presence of high concentrations of salt, non-ionic detergent, urea or metal chelators. Metal chelation during glue secretion, however, may block some of these cross-links. Such robust, non-specific interactions in an aqueous environment are highly unusual for hydrogels and reflect an intriguing cross-linking mechanism. PMID:18952190

Novel Culturing Techniques Select for Heterotrophs and Hydrocarbon Degraders in a Subantarctic Soil

PubMed Central

van Dorst, J. M.; Hince, G.; Snape, I.; Ferrari, B. C.

2016-01-01

The soil substrate membrane system (SSMS) is a novel micro-culturing technique targeted at terrestrial soil systems. We applied the SSMS to pristine and diesel fuel spiked polar soils, along with traditional solid media culturing and culture independent 454 tag pyrosequencing to elucidate the effects of diesel fuel on the soil community. The SSMS enriched for up to 76% of the total soil diversity within high diesel fuel concentration soils, in contrast to only 26% of the total diversity for the control soils. The majority of organisms originally recovered with the SSMS were lost in the transfer to solid media, with all 300 isolates belonging to Proteobacteria, Firmicutes, Actinobacteria or Bacteroidetes, the four phyla most frequently associated with soil culturing efforts. The soils spiked with high diesel fuel concentrations exhibited reduced species richness, diversity and a selection towards heterotrophs and hydrocarbon degraders in comparison to the control soils. Based on these observations and the unusually high level of overlap in microbial taxa observed between methods, we suggest the SSMS holds potential to exploit hydrocarbon degraders and other targets within simplified bacterial systems, yet is inadequate for soil ecology and ecotoxicology studies where identifying rare oligotrophic species is paramount. PMID:27827405

The molecular refractive function of lens γ-crystallins

PubMed Central

Zhao, Huaying; Brown, Patrick H.; Magone, M. Teresa; Schuck, Peter

2011-01-01

γ-crystallins constitute the major protein component in the nucleus of the vertebrate eye lens. Present at very high concentrations, they exhibit extreme solubility and thermodynamic stability to prevent scattering of light and the formation of cataracts. However, functions beyond this structural role have remained mostly unclear. Here, we calculate molecular refractive index increments of crystallins. We show that all lens γ-crystallins have evolved a significantly elevated molecular refractive index increment, which is far above those of most proteins, including non-lens members of the βγ-crystallin family from different species. The same trait has evolved in parallel in crystallins of different phyla, including in the S-crystallins of cephalopods. A high refractive index increment can lower the crystallin concentration required to achieve a suitable refractive power of the lens, and thereby reduce their propensity to aggregate and form cataract. To produce a significant increase of the refractive index increment, a substantial global shift in the amino acid composition is required, which can naturally explain the highly unusual amino acid composition of γ-crystallins and their functional homologues. This function provides a new perspective for interpreting their molecular structure. PMID:21684289

Robust cross-links in molluscan adhesive gels: testing for contributions from hydrophobic and electrostatic interactions.

PubMed

Smith, A M; Robinson, T M; Salt, M D; Hamilton, K S; Silvia, B E; Blasiak, R

2009-02-01

The cross-linking interactions that provide cohesive strength to molluscan adhesive gels were investigated. Metal-based interactions have been shown to play an important role in the glue of the slug Arion subfuscus (Draparnaud), but other types of interactions may also contribute to the glue's strength and their role has not been investigated. This study shows that treatments that normally disrupt hydrophobic or electrostatic interactions have little to no effect on the slug glue. High salt concentrations and non-ionic detergent do not affect the solubility of the proteins in the glue or the ability of the glue proteins to stiffen gels. In contrast, metal chelation markedly disrupts the gel. Experiments with gel filtration chromatography identify a 40 kDa protein that is a central component of the cross-links in the glue. This 40 kDa protein forms robust macromolecular aggregations that are stable even in the presence of high concentrations of salt, non-ionic detergent, urea or metal chelators. Metal chelation during glue secretion, however, may block some of these cross-links. Such robust, non-specific interactions in an aqueous environment are highly unusual for hydrogels and reflect an intriguing cross-linking mechanism.

The molecular refractive function of lens γ-Crystallins.

PubMed

Zhao, Huaying; Brown, Patrick H; Magone, M Teresa; Schuck, Peter

2011-08-19

γ-Crystallins constitute the major protein component in the nucleus of the vertebrate eye lens. Present at very high concentrations, they exhibit extreme solubility and thermodynamic stability to prevent scattering of light and formation of cataracts. However, functions beyond this structural role have remained mostly unclear. Here, we calculate molecular refractive index increments of crystallins. We show that all lens γ-crystallins have evolved a significantly elevated molecular refractive index increment, which is far above those of most proteins, including nonlens members of the βγ-crystallin family from different species. The same trait has evolved in parallel in crystallins of different phyla, including S-crystallins of cephalopods. A high refractive index increment can lower the crystallin concentration required to achieve a suitable refractive power of the lens and thereby reduce their propensity to aggregate and form cataracts. To produce a significant increase in the refractive index increment, a substantial global shift in amino acid composition is required, which can naturally explain the highly unusual amino acid composition of γ-crystallins and their functional homologues. This function provides a new perspective for interpreting their molecular structure. Copyright © 2011. Published by Elsevier Ltd.

Fatal fat embolism in isolated vertebral compression fracture

PubMed Central

Saldanha, Vilas; Balasubramanian, Manjula; Handal, John

2010-01-01

Fat embolism after long bone and pelvic fractures as well as orthopedic interventions is a well-documented phenomenon, but it is highly unusual after isolated vertebral fractures. We report a case of fatal fat embolism in a 78-year-old man after an isolated vertebral compression fracture with no related orthopedic intervention. A high index of suspicion is necessary for early diagnosis and successfully treating this unusual complication. PMID:20229119

Fatal fat embolism in isolated vertebral compression fracture.

PubMed

Lastra, Ricardo R; Saldanha, Vilas; Balasubramanian, Manjula; Handal, John

2010-07-01

Fat embolism after long bone and pelvic fractures as well as orthopedic interventions is a well-documented phenomenon, but it is highly unusual after isolated vertebral fractures. We report a case of fatal fat embolism in a 78-year-old man after an isolated vertebral compression fracture with no related orthopedic intervention. A high index of suspicion is necessary for early diagnosis and successfully treating this unusual complication.

Organic and metal contamination in marine surface sediments of Guánica Bay, Puerto Rico.

PubMed

Whitall, David; Mason, Andrew; Pait, Anthony; Brune, Lia; Fulton, Michael; Wirth, Ed; Vandiver, Lisa

2014-03-15

Land based sources of pollution have the potential to adversely impact valuable coral reef ecosystems. In Guánica Bay (Puerto Rico) sediment samples collected and analyzed in 2009 demonstrate unusually high concentrations of total chlordane, total PCBs, nickel and chromium. A variety of other contaminants (total DDT, total PAHs, As, Cu, Hg, and Zn) were also at levels which may indicate sediment toxicity. With the exception of chromium, all of these contaminants were detected in coral tissues (Porites astreoides), although it is unclear at what level these contaminants affect coral health. PCBs and chlordane are environmentally persistent and likely represent legacy pollution from historical uses in close geographic proximity to the Bay. We hypothesize that the high nickel and chromium levels are due to a combination of naturally high Ni and Cr in rock and soils in the watershed, and enhanced (human driven) erosional rates. Published by Elsevier Ltd.

Unusual Evolution of the Conduction-Electron State in CexLa1-xB6 from Non-Fermi Liquid to Fermi Liquid

NASA Astrophysics Data System (ADS)

Nakamura, S.; Endo, M.; Yamamoto, H.; Isshiki, T.; Kimura, N.; Aoki, H.; Nojima, T.; Otani, S.; Kunii, S.

2006-12-01

We report unusual evolution of the conduction-electron state in the localized f electron system CexLa1-xB6 from normal electron state to heavy Fermi liquid (FL) state through local FL and non-FL states with increasing Ce concentration and/or with increasing magnetic field. The effective mass of quasiparticle or the coefficient A of T2 term of resistivity is found to increase divergently near the boundary between FL state and non-FL state. The features of the non-FL state are also different from those of the typical non-FL systems previously observed or theoretically predicted.

Recognition of unusual presentation of natural killer cell leukemia.

PubMed

Gardiner, C M; Reen, D J; O'Meara, A

1995-10-01

Expansion of the natural killer (NK) subset of lymphocytes represents a rare leukemia phenotype with variations in clinical presentation, morphology, surface phenotype, and effector function. This paper reports on a 5-year-old male patient who had an unusual presentation of an NK cell leukemia that was initially diagnosed as neuroblastoma. A bone marrow (BM) aspirate showed clumps of undifferentiated cells with the following phenotype: CD56bright+, CD33dim+, CD45-, CD2-, CD19-, CD16-, and CD57-. Cytochemistry was noncontributory. The patient, having failed to respond to conventional neuroblastoma chemotherapy, was subsequently diagnosed as having NK cell leukemia based on functional in vitro assays. The patient responded to acute lymphoblastic leukemia (ALL) chemotherapy but relapsed 4 weeks into treatment and eventually died 25 weeks after initial presentation. The cell surface phenotype observed is consistent with a rare NK cell subset, the biology of which has not been well defined. Freshly isolated BM cells killed K562 cells in a conventional 51Cr-release assay. Both interleukin-2 (IL-2) and interferon-alpha (IFN-alpha) induced LAK activity against the Daudi cell line. IL-2 induced proliferation of the leukemic cells. TNF-alpha, IFN-gamma, IL-6, IL-1ra, and TGF-beta levels were assessed and found to be concentrated in BM, in contrast to plasma samples. TNF-alpha was present at a high concentration in BM (150.9 pg/ml), probably a reflection of the associated disease pathology of severe bone pain and pyrexia. In summary, this paper details clinical and laboratory investigations of a leukemia of a rare NK cell subset.

Groundwater noble gas, age, and temperature signatures in an Alpine watershed: Valuable tools in conceptual model development

USGS Publications Warehouse

Manning, Andrew H.; Caine, Jonathan S.

2007-01-01

Bedrock groundwater in alpine watersheds is poorly understood, mainly because of a scarcity of wells in alpine settings. Groundwater noble gas, age, and temperature data were collected from springs and wells with depths of 3–342 m in Handcart Gulch, an alpine watershed in Colorado. Temperature profiles indicate active groundwater circulation to a maximum depth (aquifer thickness) of about 200 m, or about 150 m below the water table. Dissolved noble gas data show unusually high excess air concentrations (>0.02 cm3 STP/g, ΔNe > 170%) in the bedrock, consistent with unusually large seasonal water table fluctuations (up to 50 m) observed in the upper part of the watershed. Apparent 3H/3He ages are positively correlated with sample depth and excess air concentrations. Integrated samples were collected from artesian bedrock wells near the trunk stream and are assumed to approximate flow‐weighted samples reflecting bedrock aquifer mean residence times. Exponential mean ages for these integrated samples are remarkably consistent along the stream, four of five being from 8 to 11 years. The tracer data in combination with other hydrologic and geologic data support a relatively simple conceptual model of groundwater flow in the watershed in which (1) permeability is primarily a function of depth; (2) water table fluctuations increase with distance from the stream; and (3) recharge, aquifer thickness, and porosity are relatively uniform throughout the watershed in spite of the geological complexity of the Proterozoic crystalline rocks that underlie it.

An unusual occurrence of plasmid-mediated blaOXA-23 carbapenemase in clinical isolates of Escherichia coli from India.

PubMed

Paul, Deepjyoti; Ingti, Birson; Bhattacharjee, Dibyojyoti; Maurya, Anand Prakash; Dhar, Debadatta; Chakravarty, Atanu; Bhattacharjee, Amitabha

2017-05-01

The bla OXA-23 group was considered as the first group of OXA-type β-lactamases conferring carbapenem resistance and has been reported worldwide in Acinetobacter baumannii, however their presence in Escherichia coli is very rare and unique. This study describes an unusual occurrence of bla OXA-23 in 14 clinical isolates of E. coli obtained from intensive care unit patients admitted to a tertiary referral hospital in India. The bla OXA-23 gene was found located within a self-conjugative plasmid of IncF rep B and IncK incompatibility types and simultaneously carrying bla CTX-M-15 , bla VEB-1 , bla PER-1 and/or bla NDM-1 . The copy number of bla OXA-23 within the IncK-type plasmid was inversely proportional to increasing concentrations of imipenem, whereas in the case of the IncF rep B-type the result was variable; and increased copy number of the IncK-type plasmid was observed with increasing concentrations of meropenem. Plasmids encoding bla OXA-23 could be successfully eliminated after single treatment and were found to be not highly stable, as complete loss of plasmids was observed within 5-10 days. This study emphasises that carbapenem stress invariably altered the copy number of two different Inc type plasmids encoding the bla OXA-23 resistance gene and also highlights a potential threat of clonal expansion of this class D carbapenemase through a heterologous host in this country, which is in second incidence globally. Copyright © 2017 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

The impacts of a massive harmful algal bloom along the US west coast in 2015

NASA Astrophysics Data System (ADS)

Kudela, R. M.; Trainer, V. L.; McCabe, R. M.; Hickey, B. M.; Negrey, K.

2016-02-01

In 2015, a massive bloom of the marine diatom Pseudo-nitzschia, stretching from southern California to southern Alaska, resulted in significant impacts to coastal resources and marine life. This bloom was first detected in early May 2015, when Washington closed its scheduled razor clam digs on coastal beaches. It is the largest and longest-lasting bloom in at least the past 15 years, and concentrations of domoic acid in seawater, some forage fish, and crab samples have been among the highest ever reported for this region. By mid-May, domoic acid concentrations in Monterey Bay, California were 10 to 30 times the level that would be considered high for a normal Pseudo-nitzschia bloom. Impacts to coastal communities and marine life include shellfish and Dungeness crab closures in multiple states, impacting commercial, recreational and subsistence harvesters, anchovy and sardine fishery health advisories in some areas of California, and sea lion strandings in California and Washington. Other marine mammal and bird mortalities have been reported in multiple states, and domoic acid poisoning is a suspected cause. In addition to the spatial extent and toxicity, the bloom has also lasted for many months (ongoing as of September 2015). While the exact causes of the bloom's severity and early onset are not yet known, unusually warm surface water in the Pacific Ocean may be a contributing factor. Here we present an overview of the bloom dynamics and impacts, and preliminary analysis about the bloom initiation and relationship to unusual ocean conditions in 2014-2015.

Geochemistry and mineralogy of Pd in the magnetitite layer within the upper gabbro of the Mesoarchean Nuasahi Massif (Orissa, India)

NASA Astrophysics Data System (ADS)

Prichard, Hazel M.; Mondal, Sisir K.; Mukherjee, Ria; Fisher, Peter C.; Giles, Nicolas

2018-04-01

Palladium concentrations of 1-3 ppm with an average Pt/Pd ratio of 0.15 have been located for the first time in a magnetitite layer in the Nuasahi Massif in Orissa India. This layer occurs at a high stratigraphic level in the complex and is nearly 4-km long and 5-12-m thick. The sections of the Pd-rich zone identified to date extend over a distance of 1 km at the southern end of the layer. Several phases of mineralization are evident. The first, primary assemblage of platinum-group minerals (PGM) contains Pd-sulfides (vysotskite), Pd-Pb alloys (zvyagintsevite), and a Pd-In alloy, a mineral probably new to mineralogy. These PGM are confined to central magnetite grains in the magnetitites. The magnetite grains with exsolved fine laths of ilmenite at centers are referred to as central magnetite grains. These central magnetite grains are commonly surrounded by blebs of ilmenite and magnetite that contain the majority of the PGM. These are dominated by Pd-antimonides, variably altered to Pd-oxides, and other PGM including PtAs2 (sperrylite), RuS2 (laurite), and IrRhAsS (irarsite/hollingwothite). Many of these PGM also occur in the interstitial silicates, with rare occurrences in the central magnetite grains. We propose that the platinum-group elements (PGE) crystallized during a minor sulfide saturation event that occurred as the magnetitites crystallized. This event produced the minor Cu-sulfides in these magnetitites. Later introduction of antimony and arsenic, during the alteration event that produced the blebby ilmenite and magnetite, led to the more primary PGM being succeeded by the main PGM assemblage, dominated by Pd-antimonides. These are associated with secondary Cu minerals and sperrylite. Subsequent oxidation during weathering in the hot wet Indian climate produced the Pd-oxides. The Nuasahi Massif is a sill-like Archean layered ultramafic-mafic intrusion genetically linked to high-Mg siliceous basalt or boninites and is characterized by unusually thick layers of chromitite. PGE are concentrated in these chromitites and in the base metal sulfide-bearing breccias in the overlying gabbro. The Pd in the magnetitites described here indicates the presence of a third level where PGE are concentrated and a magma that crystallized to produce PGE concentrations at three stratigraphic levels in the massif. This indicates that similar thin sill-like intrusions, hosting unusually thick chromitites, may also have PGE concentrations at a number of stratigraphic levels.

Research Progress towards Understanding the Unique Interfaces between Concentrated Electrolytes and Electrodes for Energy Storage Applications

PubMed Central

Lochala, Joshua A.; Kwok, Alexander; Deng, Zhiqun Daniel

2017-01-01

The electrolyte is an indispensable component in all electrochemical energy storage and conversion devices with batteries being a prime example. While most research efforts have been pursued on the materials side, the progress for the electrolyte is slow due to the decomposition of salts and solvents at low potentials, not to mention their complicated interactions with the electrode materials. The general properties of bulk electrolytes such as ionic conductivity, viscosity, and stability all affect the cell performance. However, for a specific electrochemical cell in which the cathode, anode, and electrolyte are optimized, it is the interface between the solid electrode and the liquid electrolyte, generally referred to as the solid electrolyte interphase (SEI), that dictates the rate of ion flow in the system. The commonly used electrolyte is within the range of 1–1.2 m based on the prior optimization experience, leaving the high concentration region insufficiently recognized. Recently, electrolytes with increased concentration (>1.0 m) have received intensive attention due to quite a few interesting discoveries in cells containing concentrated electrolytes. The formation mechanism and the nature of the SEI layers derived from concentrated electrolytes could be fundamentally distinct from those of the traditional SEI and thus enable unusual functions that cannot be realized using regular electrolytes. In this article, we provide an overview on the recent progress of high concentration electrolytes in different battery chemistries. The experimentally observed phenomena and their underlying fundamental mechanisms are discussed. New insights and perspectives are proposed to inspire more revolutionary solutions to address the interfacial challenges. PMID:28852621

Research Progress towards Understanding the Unique Interfaces between Concentrated Electrolytes and Electrodes for Energy Storage Applications

DOE PAGES

Zheng, Jianming; Lochala, Joshua A.; Kwok, Alexander; ...

2017-03-31

The electrolyte is an indispensable component in all electrochemical energy storage and conversion devices, for example, batteries. While most research efforts have been pursued on the materials side, the progress for the electrolyte is slow due to the decomposition of salts and solvents at low potentials, not to mention their complicated interactions with the electrode materials. The general properties of bulk electrolytes such as ionic conductivity, viscosity, and stability all affect the cell performance. However, for a specific electrochemical cell in which the cathode, anode and electrolyte are optimized, it is the interface between the solid electrode and the liquidmore » electrolyte, generally referred to as the solid electrolyte interphase (SEI), that dictates the rate of ion flow in the system. The commonly used electrolyte is within the range of 1-1.2 M based on the prior optimization experience, leaving the high concentration region insufficiently recognized. Recently, electrolytes with increased concentration (> 1.0 M) have received additional attention due to quite a few interesting discoveries in cells containing concentrated electrolytes. The formation mechanism and the nature of the SEI layers derived from concentrated electrolytes could be fundamentally different from those of the traditional SEI and thus enable unusual functions that cannot be realized using regular electrolytes. In this article, we provide an overview on the recent progress of high concentration electrolytes in different battery chemistries. The experimentally observed phenomena and their underlying fundamental mechanism are discussed. As a result, new insights and perspectives are proposed to inspire more revolutionary solutions to address the interfacial challenges.« less

Research Progress towards Understanding the Unique Interfaces between Concentrated Electrolytes and Electrodes for Energy Storage Applications.

PubMed

Zheng, Jianming; Lochala, Joshua A; Kwok, Alexander; Deng, Zhiqun Daniel; Xiao, Jie

2017-08-01

The electrolyte is an indispensable component in all electrochemical energy storage and conversion devices with batteries being a prime example. While most research efforts have been pursued on the materials side, the progress for the electrolyte is slow due to the decomposition of salts and solvents at low potentials, not to mention their complicated interactions with the electrode materials. The general properties of bulk electrolytes such as ionic conductivity, viscosity, and stability all affect the cell performance. However, for a specific electrochemical cell in which the cathode, anode, and electrolyte are optimized, it is the interface between the solid electrode and the liquid electrolyte, generally referred to as the solid electrolyte interphase (SEI), that dictates the rate of ion flow in the system. The commonly used electrolyte is within the range of 1-1.2 m based on the prior optimization experience, leaving the high concentration region insufficiently recognized. Recently, electrolytes with increased concentration (>1.0 m) have received intensive attention due to quite a few interesting discoveries in cells containing concentrated electrolytes. The formation mechanism and the nature of the SEI layers derived from concentrated electrolytes could be fundamentally distinct from those of the traditional SEI and thus enable unusual functions that cannot be realized using regular electrolytes. In this article, we provide an overview on the recent progress of high concentration electrolytes in different battery chemistries. The experimentally observed phenomena and their underlying fundamental mechanisms are discussed. New insights and perspectives are proposed to inspire more revolutionary solutions to address the interfacial challenges.

Research Progress towards Understanding the Unique Interfaces between Concentrated Electrolytes and Electrodes for Energy Storage Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zheng, Jianming; Lochala, Joshua A.; Kwok, Alexander

The electrolyte is an indispensable component in all electrochemical energy storage and conversion devices, for example, batteries. While most research efforts have been pursued on the materials side, the progress for the electrolyte is slow due to the decomposition of salts and solvents at low potentials, not to mention their complicated interactions with the electrode materials. The general properties of bulk electrolytes such as ionic conductivity, viscosity, and stability all affect the cell performance. However, for a specific electrochemical cell in which the cathode, anode and electrolyte are optimized, it is the interface between the solid electrode and the liquidmore » electrolyte, generally referred to as the solid electrolyte interphase (SEI), that dictates the rate of ion flow in the system. The commonly used electrolyte is within the range of 1-1.2 M based on the prior optimization experience, leaving the high concentration region insufficiently recognized. Recently, electrolytes with increased concentration (> 1.0 M) have received additional attention due to quite a few interesting discoveries in cells containing concentrated electrolytes. The formation mechanism and the nature of the SEI layers derived from concentrated electrolytes could be fundamentally different from those of the traditional SEI and thus enable unusual functions that cannot be realized using regular electrolytes. In this article, we provide an overview on the recent progress of high concentration electrolytes in different battery chemistries. The experimentally observed phenomena and their underlying fundamental mechanism are discussed. As a result, new insights and perspectives are proposed to inspire more revolutionary solutions to address the interfacial challenges.« less

An unusual percutaneous transmitral commissurotomy: A collection of four rare occurrences!

PubMed

Shankarappa, Ravindranath K; Agrawal, Navin; Patra, Soumya; Karur, Satish; Nanjappa, Manjunath C

2013-09-01

We are presenting an interesting case of a 30-year-old patient taken for percutaneous transvenous mitral commissurotomy (PTMC) for severe rheumatic mitral stenosis in which there was a collection of four unusual occurrences during the course of a procedure. She had recurrent generalized tonic-clonic seizures immediately after femoral sheath insertion requiring the patient to be mechanically ventilated. Subsequently, the pressure tracings recorded with catheters in the aorta and the pulmonary artery showed transient unusually high supra-systemic pulmonary artery pressure. During inflation the Accura PTMC balloon which was used to dilate the mitral valve ruptured and the procedure subsequently had to be completed using another balloon catheter. During the procedure the presence of a distended stomach due to insufflations of air during positive pressure ventilation which subsided subsequently was another unusual documentation on fluoroscopy. The final outcome of the procedure was successful. This case presents an interesting collection of unusual occurrences during a PTMC procedure which started on an unusual note but ended on a successful one. Careful assessment and appropriate management of complications can lead to successful outcome of procedures as in our case.

Organic matter and the geotechnical properties of submarine sediments

NASA Astrophysics Data System (ADS)

Keller, George H.

1982-09-01

Continental slope deposits off Peru and Oregon where coastal upwelling is a pronounced oceanographic process possess significant concentrations of organic carbon. Geotechnical properties are altered to varying degrees by the organic matter. Organic matter absorbs water and causes clay-size particles to aggregate forming an open fabric. This causes unusually high water contents and plasticity and exceptionally low wet bulk densities. Some of these deposits show notable increases in shear strength, sensitivity and degree of apparent overconsolidation. Owing to the unique geotechnical properties, sediment stability characteristics are considered to be poor in situations of excess pore pressures. Failure appears to take the form of a fluidized flow somewhat similar to the quick clays of Scandinavia.

Massive intoxication involving unusual high concentration of amitriptyline.

PubMed

Margalho, Cláudia; Barroso, Mário; Gallardo, Eugenia; Monsanto, Paula; Vieira, Duarte Nuno

2007-08-01

Amitriptyline is a tricyclic antidepressant widely used in the treatment of depression. Antidepressant drugs are among the most commonly encountered causes of self-poisoning, as illustrated by several published cases in the literature. This investigation reports a case of massive amitriptyline intoxication, involving a 44-year old female found dead in bed. The presence of this tricyclic antidepressant was revealed by a routine screening procedure. The concentration was calculated by gas chromatography/ electron ionization-mass spectrometry in the selected ion monitoring mode after solid-phase extraction using proadifen as internal standard and was in the post-mortem whole blood sample 85.9 mug/mL. This value was much higher than the reported toxic values ever found in the literature, and may therefore have caused the victim's death. Nortriptyline was also detected in the toxic concentration range, as well as therapeutic levels of diazepam and nor-diazepam. Taking into account both the available circumstantial information and toxicological results, it is very likely that death was caused by self-poisoning. Human & Experimental Toxicology (2007) 26, 667-670.

Copper tolerance mediated by polyphosphate degradation and low-affinity inorganic phosphate transport system in Escherichia coli.

PubMed

Grillo-Puertas, Mariana; Schurig-Briccio, Lici Ariane; Rodríguez-Montelongo, Luisa; Rintoul, María Regina; Rapisarda, Viviana Andrea

2014-03-19

Metal tolerance in bacteria has been related to polyP in a model in which heavy metals stimulate the polymer hydrolysis, forming metal-phosphate complexes that are exported. As previously described in our laboratory, Escherichia coli cells grown in media containing a phosphate concentration >37 mM maintained an unusually high polyphosphate (polyP) level in stationary phase. The aim of the present work was to evaluate the influence of polyP levels as the involvement of low-affinity inorganic phosphate transport (Pit) system in E. coli copper tolerance. PolyP levels were modulated by the media phosphate concentration and/or using mutants in polyP metabolism. Stationary phase wild-type cells grown in high phosphate medium were significantly more tolerant to copper than those grown in sufficient phosphate medium. Copper addition to tolerant cells induced polyP degradation by PPX (an exopolyphosphatase), phosphate efflux and membrane polarization. ppk-ppx- (unable to synthesize/degrade polyP), ppx- (unable to degrade polyP) and Pit system mutants were highly sensitive to metal even in high phosphate media. In exponential phase, CopA and polyP-Pit system would act simultaneously to detoxify the metal or one could be sufficient to safeguard the absence of the other. Our results support a mechanism for copper detoxification in exponential and stationary phases of E. coli, involving Pit system and degradation of polyP. Data reflect the importance of the environmental phosphate concentration in the regulation of the microbial physiological state.

Evidence of Anomalously Low δ13C of Marine Organic Matter in an Arctic Fjord

PubMed Central

Kumar, Vikash; Tiwari, Manish; Nagoji, Siddhesh; Tripathi, Shubham

2016-01-01

Accurate estimation of relative carbon deposition (marine vs. terrestrial) is required for understanding the global carbon budget, particularly in the Arctic region, which holds disproportionate importance with respect to global carbon cycling. Although the sedimentary organic matter (SOM) concentration and its isotopic composition are important tools for such calculations, uncertainties loom over estimates provided by organic-geochemical bulk parameters. We report carbon and nitrogen concentrations and isotopes (δ13C and δ15N) of SOM at an Arctic fjord namely Kongsfjorden. We find that the bound inorganic nitrogen (ammonium attached to the clay minerals) forms a significant proportion of total nitrogen concentration (~77% in the inner fjord to ~24% in the outer part). On removing the bound nitrogen, the C/N ratio shows that the SOM in the inner fjord is made up of terrestrial carbon while the outer fjord shows mixed marine-terrestrial signal. We further show that the marine organic matter is unusually more depleted in 13C (~−24‰) than the terrestrial organic matter (~−22.5‰). This particular finding also helps explain high δ13C values of SOM as noted by earlier studies in central Arctic sediments despite a high terrestrial contribution. PMID:27827457

The atypical excretion profile of meldonium: Comparison of urinary detection windows after single- and multiple-dose application in healthy volunteers.

PubMed

Görgens, Christian; Guddat, Sven; Bosse, Christina; Geyer, Hans; Pop, Valentin; Schänzer, Wilhelm; Thevis, Mario

2017-05-10

Following a one-year monitoring program providing unequivocal analytical evidence for a high prevalence in international elite sports, meldonium has been included in the World Anti-Doping Agency's (WADA) list of prohibited substances that came into effect on 1 January 2016. Despite of the polar and hydrophilic nature of the molecule, an unusual long detection window was observed in pilot elimination studies. Consequently, in the present study, urinary excretion profiles after single-dose (5 volunteers, 1×500mg) and multiple-dose oral application (5 volunteers; 2×500mg/day for 6days) were determined in order to facilitate the result management concerning meldonium findings in doping controls. Particularly the option to differentiate between recent use and tapering concentrations was studied. Urinary meldonium concentrations were determined using an analytical approach based on hydrophilic interaction liquid chromatography and high resolution tandem mass spectrometry. The study corroborates the hypothesis of a non-linear, dose-depended and biphasic excretion profile after oral application of meldonium and demonstrates that urinary detection windows are of considerable extent with up to 65 and 117days (concentrations>LOQ of 10ng/mL) following single- and multiple-dose applications, respectively. Copyright © 2017 Elsevier B.V. All rights reserved.

Magnetic vortex excitation as spin torque oscillator and its unusual trajectories

NASA Astrophysics Data System (ADS)

Natarajan, Kanimozhi; Muthuraj, Ponsudana; Rajamani, Amuda; Arumugam, Brinda

2018-05-01

We report an interesting observation of unusual trajectories of vortex core oscillations in a spin valve pillar. Micromagnetic simulation in the composite free layer spin valve nano-pillar shows magnetic vortex excitation under critical current density. When current density is slightly increased and wave vector is properly tuned, for the first time we observe a star like and square gyration. Surprisingly this star like and square gyration also leads to steady, coherent and sustained oscillations. Moreover, the frequency of gyration is also very high for this unusual trajectories. The power spectral analysis reveals that there is a marked increase in output power and frequency with less distortions. Our investigation explores the possibility of these unusual trajectories to exhibit spin torque oscillations.

Liquid ``Coffee Rings'' and the Spreading of Volatile Liquid Mixtures

NASA Astrophysics Data System (ADS)

Wood, Clay; Pye, Justin; Burton, Justin

When a volatile liquid drop is placed on a wetting surface, it rapidly spreads and evaporates. The spreading dynamics and drop geometry are determined by a balance between thermal and interfacial forces, including Marangoni effects. However, this spreading behavior is drastically altered when drops contain a miniscule amount of a less-volatile miscible liquid (solute) in the bulk (solvent); contact line instabilities in the form of ``fingers'' develop. Characteristic finger size increases with increasing solute concentration and is apparent for concentrations as small as 0.1% by volume. Also, the spreading rate depends sensitively on the solute concentration, especially if the solute preferentially wets the substrate. At higher solute concentrations, the spreading droplet will form ``beads'' at the contact line, rather than fingers, and are deposited as the solvent recedes and evaporates, leaving behind a complex pattern of solute micro-droplets. Liquid ``coffee rings'' are often left behind after evaporation because there is a high evaporation rate of the solvent at the contact line, which increases the concentration of the solute, and the longevity of the rings depends on the solute vapor pressure. These results highlight the unusual sensitivity to contamination of volatile spreading, and the complex patterns of liquid contamination deposited following evaporation from a wetted surface. NSF 1455086.

Unusual CoS2 ellipsoids with anisotropic tube-like cavities and their application in supercapacitors.

PubMed

Zhang, Lei; Wu, Hao Bin; Lou, Xiong Wen

2012-07-14

Unusual CoS(2) ellipsoids with anisotropic tube-like cavities have been synthesized from the simultaneous thermal decomposition and sulfidation of a preformed cobalt carbonate precursor. The as-prepared CoS(2) ellipsoids show interesting supercapacitive properties with high capacitance and good cycling performance.

Engineering the production of conjugated fatty acids in Arabidopsis thaliana leaves

USDA-ARS?s Scientific Manuscript database

The seeds of many non-domesticated plant species synthesize oils containing high amounts of a single unusual fatty acid, many of which have potential usage in industry. Despite the identification of enzymes for unusual oxidized fatty acid synthesis, the production of these fatty acids in engineered ...

Composition of microbial communities in aerosol, snow and ice samples from remote glaciated areas (Antarctica, Alps, Andes)

NASA Astrophysics Data System (ADS)

Elster, J.; Delmas, R. J.; Petit, J.-R.; Řeháková, K.

2007-06-01

Taxonomical and ecological analyses were performed on micro-autotrophs (cyanobacteria and algae together with remnants of diatom valves), micro-fungi (hyphae and spores), bacteria (rod, cocci and red clusters), yeast, and plant pollen extracted from various samples: Alps snow (Mt. Blank area), Andean snow (Illimani, Bolivia), Antarctic aerosol filters (Dumont d'Urville, Terre Adélie), and Antarctic inland ice (Terre Adélie). Three methods for ice and snow sample's pre-concentration were tested (filtration, centrifugation and lyophilisation). Afterwards, cultivation methods for terrestrial, freshwater and marine microorganisms (micro-autotrophs and micro-fungi) were used in combination with liquid and solid media. The main goal of the study was to find out if micro-autotrophs are commonly transported by air masses, and later stored in snow and icecaps around the world. The most striking result of this study was the absence of culturable micro-autotrophs in all studied samples. However, an unusual culturable pigmented prokaryote was found in both alpine snow and aerosol samples. Analyses of many samples and proper statistical analyses (PCA, RDA- Monte Carlo permutation tests) showed that studied treatments highly significantly differ in both microbial community and biotic remnants composition F=9.33, p=0.001. In addition, GLM showed that studied treatments highly significantly differ in numbers of categories of microorganisms and remnants of biological material F=11.45, p=0.00005. The Antarctic aerosol samples were characterised by having red clusters of bacteria, the unusual prokaryote and yeasts. The high mountain snow from the Alps and Andes contained much more culturable heterotrophs. The unusual prokaryote was very abundant, as were coccoid bacteria, red clusters of bacteria, as well as yeasts. The Antarctic ice samples were quite different. These samples had higher numbers of rod bacteria and fungal hyphae. The microbial communities and biological remnants of analysed samples comprises two communities, without a sharp boundary between them: i) the first community includes ubiquitous organisms including contaminants, ii) the second community represents individuals frequently occurring in remote terrestrial cold or hot desert/semi-desert and/or marginal soil-snow-ice ecosystems.

Anomalous abundances of deep-sea fauna on a rocky bottom exposed to strong currents

USGS Publications Warehouse

Genin, A.; Paull, C.K.; Dillon, William P.

1992-01-01

Unusually high abundances of sponges and gorgonian corals, covering as much as 25% of the bottom, occur at depths greater than 3.5 km on the Blake Spur, a rocky cliff-dominated feature on the western Atlantic continental margin. This is the first report of such high abundances of megafauna from a non-hydrothermal or otherwise chemosynthetically enriched site in abyssal depths. Animal densities at other steep rocky sites at similar depths are usually lower by more than an order of magnitude. The deep slope of the Blake Spur is exposed to the vigorous Western Boundary Undercurrent, with local flow speeds that may exceed 100 cm s-1. Currents can control this anomalous animal abundance by removing sediments and by enhancing fluxes, rather than concentrations, of food particles to the dominant suspension feeders. ?? 1992.

Mechanism of Electrophilic Fluorination with Pd(IV): Fluoride Capture and Subsequent Oxidative Fluoride Transfer†, ‡

PubMed Central

Brandt, Jochen R.; Lee, Eunsung; Boursalian, Gregory B.

2013-01-01

Electrophilic fluorinating reagents derived from fluoride are desirable for the synthesis of 18F-labeled molecules for positron emission tomography (PET). Here, we study the mechanism by which a Pd(IV)-complex captures fluoride and subsequently transfers it to nucleophiles. The intermediate Pd(IV)-F is formed with high rates even at the nano- to micromolar fluoride concentrations typical for radiosyntheses with 18F due to fast formation of an outer-sphere complex between fluoride and Pd(IV). The subsequent fluorine transfer from the Pd(IV)-F complex is proposed to proceed through an unusual SET/fluoride transfer/SET mechanism. The findings detailed in this manuscript provide a theoretical foundation suitable for addressing a more general approach for electrophilic fluorination with high specific activity 18F PET imaging. PMID:24376910

Temporal fluctuations in grain size, organic materials and iron concentrations in intertidal surface sediment of San Francisco Bay

USGS Publications Warehouse

Thomson-Becker, E. A.; Luoma, S.N.

1985-01-01

The physical and chemical characteristics of the oxidized surface sediment in an estuary fluctuate temporally in response to physical forces and apparently-fluctuating inputs. These characteristics, which include grain size and concentrations of organic materials and iron, will influence both trace-metal geochemistry and bioavailability. Temporal trends in the abundance of fine particles, total organic carbon content (TOC), absorbance of extractable organic material (EOM), and concentration of extractable iron in the sediment of San Francisco Bay were assessed using data sets containing approximately monthly samples for periods of two to seven years. Changes in wind velocity and runoff result in monthly changes in the abundance of fine particles in the intertidal zone. Fine-grained particles are most abundant in the late fall/early winter when runoff is elevated and wind velocities are low; particles are coarser in the summer when runoff is low and wind velocities are consistently high. Throughout the bay, TOC is linearly related to fine particle abundance (r = 0.61). Temporal variability occurs in this relationship, as particles are poor in TOC relative to percent of fine particles in the early rainy season. Iron-poor particles also appear to enter the estuary during high runoff periods; while iron is enriched on particle surfaces in the summer. Concentrations of extractable iron and absorbance of EOM vary strongly from year to year. Highest absorbances of EOM occurred in the first year following the drought in 1976-77, and in 1982 and 1983 when river discharge was unusually high. Extractable-iron concentrations were also highest in 1976-77, but were very low in 1982 and 1983. ?? 1985 Dr W. Junk Publishers.

Molecular basis for the high-affinity binding and stabilization of firefly luciferase by PTC124

DOE Office of Scientific and Technical Information (OSTI.GOV)

Auld, Douglas S.; Lovell, Scott; Thorne, Natasha

2010-04-07

Firefly luciferase (FLuc), an ATP-dependent bioluminescent reporter enzyme, is broadly used in chemical biology and drug discovery assays. PTC124 Ataluren; (3-[5-(2-fluorophenyl)-1,2,4-oxadiazol-3-yl]benzoic acid) discovered in an FLuc-based assay targeting nonsense codon suppression, is an unusually potent FLuc-inhibitor. Paradoxically, PTC124 and related analogs increase cellular FLuc activity levels by posttranslational stabilization. In this study, we show that FLuc inhibition and stabilization is the result of an inhibitory product formed during the FLuc-catalyzed reaction between its natural substrate, ATP, and PTC124. A 2.0 {angstrom} cocrystal structure revealed the inhibitor to be the acyl-AMP mixed-anhydride adduct PTC124-AMP, which was subsequently synthesized and shown tomore » be a high-affinity multisubstrate adduct inhibitor (MAI; KD = 120 pM) of FLuc. Biochemical assays, liquid chromatography/mass spectrometry, and near-attack conformer modeling demonstrate that formation of this novel MAI is absolutely dependent upon the precise positioning and reactivity of a key meta-carboxylate of PTC124 within the FLuc active site. We also demonstrate that the inhibitory activity of PTC124-AMP is relieved by free coenzyme A, a component present at high concentrations in luciferase detection reagents used for cell-based assays. This explains why PTC124 can appear to increase, instead of inhibit, FLuc activity in cell-based reporter gene assays. To our knowledge, this is an unusual example in which the 'off-target' effect of a small molecule is mediated by an MAI mechanism.« less

Responses of the brackish-water amphipod Gammarus duebeni (crustacea) to saline sewage

NASA Astrophysics Data System (ADS)

Jones, M. B.; Johnson, I.

Soon after the openiing of the Looe sewage treatment works (Cornwall, southwest England) in 1973, it became colonized by the brackish-water amphipod Gammarus duebeni Liljeborg. The works is unusual as it operates with saline sewage and has a tidally-based pattern of salinity fluctuation (S=13 to 34). Various responses of this unique amphipod population (sewage amphipods) have been compared with G. duebeni from the adjacent Looe River estuary (estuarine amphipods) in an attempt to identify long-term responses to sewage. Sewage amphipods were significantly smaller than their estuarine equivalents; the sewage population was biased significantly to males, whereas the sex ratio of the estuarine population significantly favours females. Compared with the estuary, the consistently lower oxygen levels in the works were reflected in significant differences in metabolism. Sewage amphipods maintained high levels of activity under hypoxia ( e.g. swimming), and the higher survival and lower rates of lactic acid accumulation under anoxia than estuarine individuals. In addition, sewage amphipods recovered more rapidly from anoxia and had a lower critical oxygen tension (p c) than estuarine amphipods. Sewage amphipods are exposed to higher levels of heavy metals associated with the domestic sewage and zinc concentrations are particularly elevated in the works. Exposure to elevated zinc concentrations resulted in similar patterns of body zinc uptake for sewage and estuarine Gammarus at high (30) and low (10) salinity, with zinc regulation apparently occuring to an external threshold of 200 γmgZn·dm -3. No consistent interpopulational differences in the effect ofzinc on zinc uptake or on osmoregulation have been identified. However, sewage amphipods had higher survival at all zinc/salinity combinations compared with estuarine individuals. These indicate that sewage amphipods are adapted to the unusual combination of conditions prevailing in the treatment works and, if reproductive isolation is confirmed, suggest that the speciation process may have commenced.

Recreational atmospheric pollution episodes: Inhalable metalliferous particles from firework displays

NASA Astrophysics Data System (ADS)

Moreno, Teresa; Querol, Xavier; Alastuey, Andrés; Cruz Minguillón, Mari; Pey, Jorge; Rodriguez, Sergio; Vicente Miró, José; Felis, Carles; Gibbons, Wes

The use of fireworks creates an unusual and distinctive anthropogenic atmospheric pollution event. We report on aerosol samples collected during Las Fallas in Valencia, a 6-day celebration famous for its firework displays, and add comparative data on firework- and bonfire-contaminated atmospheric aerosol samples collected from elsewhere in Spain (Barcelona, L'Alcora, and Borriana) and during the Guy Fawkes celebrations in London. Specific high-profile official firework events during Las Fallas included the afternoon Mascletà and the nightly aerial displays (especially in the climactic final 2 days of the fiesta) and were accompanied by pollution spikes in suspended particles, NO, SO 2, and the creation and dispersal of an aerosol cloud enriched in a range of metallic elements. Notable metal aerosol concentration increases recorded during Las Fallas were potassium (from 500 to 5900 ng m -3), aluminium (as Al 2O 3 from around 600 to 2200 ng m -3), titanium (from 200 to 700 ng m -3), magnesium (from 100 to 500 ng m -3), lead (from 17 to 379 ng m -3), barium (from 39 to 322 ng m -3), strontium (from 3 to 112 ng m -3), copper (from 12 to 71 ng m -3), and antimony (from 1 to 52 ng m -3). Firework-contaminated aerosols of similarly metalliferous composition were also identified at the other monitoring sites, although different sites show variations attributable to other sources such as bonfires and local industry. Unusual levels of the trace elements Ba, Sr and (to a lesser extent) Cu, always in proportions with Ba dominant, along with strongly enhanced K, Pb, and Sb, are identified as being particularly characteristic of firework aerosols. Although firework-related recreational pollution episodes are transient in nature, they are highly concentrated, contribute significantly to total annual metal emissions, and are on average fine enough to be easily inhaled and a health risk to susceptible individuals.

Organohalide respiration and bioremediation: harnessing biogeochemical cycles (Invited)

NASA Astrophysics Data System (ADS)

Edwards, E.; Hug, L.; Perez de Mora, A.

2013-12-01

Groundwater contamination is a serious threat to global health and prosperity. Chlorinated solvents are widely used as industrial degreasers, dry-cleaning agents and precursors in chemical synthesis, and therefore are common groundwater contaminants. Owing to their toxicity, even small spills render groundwater unsuitable for use, and cleanup is typically a costly and long-term undertaking. Dehalococcoides, Dehalobacter, Dehalogenimonas and other unusual microbes have been discovered that can dechlorinate many groundwater contaminants, in particular, the common solvents tetrachloroethene and trichloroethene to the benign product ethene. Remarkably, these organisms obtain energy for growth from dechlorination in a process termed organohalide respiration. The use of biostimulation and bioaugmentation is growing, even at sites with complex hydrogeology and high concentrations of contaminants. Molecular understanding of the unusual metabolism of these organisms is helping to design successful remediation strategies. Four aspects will be emphasized: 1) the nature of the remarkable enzymes that catalyze dechlorination reactions, 2) the role of the non-dechlorinating microbes in providing essential nutrients to dechlorinating organisms, 3) the effects of mixtures of contaminants and 4) the origins of organohalide respiration. Morevoer, the hunt is on to further explore nature's diversity to discover other unusual or novel microbes capable of detoxifying a broader range of contaminants. New molecular biology and genomic tools are helping us understand how these microbes make a living, and how we can take advantage of their abilities to clean up the environment. In this presentation I will review some of the current trends in bioremediation with particular focus on how molecular tools are helping with remediation design, scope and troubleshooting. I will draw from a number of examples from my own laboratory and elsewhere.

Structure and intense UV up-conversion emissions in RE3+-doped sol-gel glass-ceramics containing KYF4 nanocrystals

NASA Astrophysics Data System (ADS)

Yanes, A. C.; Santana-Alonso, A.; Méndez-Ramos, J.; del-Castillo, J.

2013-12-01

Transparent nano-glass-ceramics containing KYF4 nanocrystals were successfully obtained by the sol-gel method, doped with Eu3+ and co-doped with Yb3+ and Tm3+ ions. Precipitation of cubic KYF4 nanocrystals was confirmed by X-ray diffraction and high-resolution transmission electron microscope images. Excitation and emission spectra let us to discern between ions into KYF4 nanocrystals and those remaining in a glassy environment, supplemented with time-resolved photoluminescence decays, that also clearly reveal differences between local environments. Unusual high-energy up-conversion emissions in the UV range were obtained in Yb3+-Tm3+ co-doped samples, and involved mechanisms were discussed. The intensity of these high-energy emissions was analyzed as a function of Yb3+ concentration, heat treatment temperature of precursor sol-gel glasses and pump power, determining the optimum values for potential optical applications as highly efficient UV up-conversion materials in UV solid-state lasers.

Al Kushaymiyah as a target for a Colorado-type molybdenite deposit

USGS Publications Warehouse

Theobald, P.K.

1971-01-01

The granitic complex in the vicinity of Al Kushaymiyah was singled out by Whitlow (19,69, 1969a, 1971), as one of the most promising areas for exploration in the Southern Wajd quadrangle (Jackson and others, 1962). He noted in particular the intensity of shattering and silicification of these potassium-rich granites, and the presence of unusual concentrations of tungsten , molybdenum, and tin in samples from the area. In the light of shield-wide compilations, this area again stands out as the principal geochemical anomaly for the three metals. The similarity of these unusual geologic and geochemical features to those of Colorado-type molybdenite deposits is striking and suggests that the Al Kushaymiyah provides a favorableenvironment to explore for a stockwork molybdenum deposit.

Latherin: A Surfactant Protein of Horse Sweat and Saliva

PubMed Central

Beeley, John G.; Bovell, Douglas L.; Lu, Jian R.; Zhao, Xiubo; Cooper, Alan; Kennedy, Malcolm W.

2009-01-01

Horses are unusual in producing protein-rich sweat for thermoregulation, a major component of which is latherin, a highly surface-active, non-glycosylated protein. The amino acid sequence of latherin, determined from cDNA analysis, is highly conserved across four geographically dispersed equid species (horse, zebra, onager, ass), and is similar to a family of proteins only found previously in the oral cavity and associated tissues of mammals. Latherin produces a significant reduction in water surface tension at low concentrations (≤1 mg ml−1), and therefore probably acts as a wetting agent to facilitate evaporative cooling through a waterproofed pelt. Neutron reflection experiments indicate that this detergent-like activity is associated with the formation of a dense protein layer, about 10 Å thick, at the air-water interface. However, biophysical characterization (circular dichroism, differential scanning calorimetry) in solution shows that latherin behaves like a typical globular protein, although with unusual intrinsic fluorescence characteristics, suggesting that significant conformational change or unfolding of the protein is required for assembly of the air-water interfacial layer. RT-PCR screening revealed latherin transcripts in horse skin and salivary gland but in no other tissues. Recombinant latherin produced in bacteria was also found to be the target of IgE antibody from horse-allergic subjects. Equids therefore may have adapted an oral/salivary mucosal protein for two purposes peculiar to their lifestyle, namely their need for rapid and efficient heat dissipation and their specialisation for masticating and processing large quantities of dry food material. PMID:19478940

Unusual social behavior in HPC-1/syntaxin1A knockout mice is caused by disruption of the oxytocinergic neural system.

PubMed

Fujiwara, Tomonori; Sanada, Masumi; Kofuji, Takefumi; Akagawa, Kimio

2016-07-01

HPC-1/syntaxin1A (STX1A), a neuronal soluble N-ethylmaleimide-sensitive fusion attachment protein receptor, contributes to neural function in the CNS by regulating transmitter release. Recent studies reported that STX1A is associated with human neuropsychological disorders, such as autism spectrum disorder and attention deficit hyperactivity disorder. Previously, we showed that STX1A null mutant mice (STX1A KO) exhibit neuropsychological abnormalities, such as fear memory deficits, attenuation of latent inhibition, and unusual social behavior. These observations suggested that STX1A may be involved in the neuropsychological basis of these abnormalities. Here, to study the neural basis of social behavior, we analyzed the profile of unusual social behavior in STX1A KO with a social novelty preference test, which is a useful method for quantification of social behavior. Interestingly, the unusual social behavior in STX1A KO was partially rescued by intracerebroventricular administration of oxytocin (OXT). In vivo microdialysis studies revealed that the extracellular OXT concentration in the CNS of STX1A KO was significantly lower compared with wild-type mice. Furthermore, dopamine-induced OXT release was reduced in STX1A KO. These results suggested that STX1A plays an important role in social behavior through regulation of the OXTergic neural system. Dopamine (DA) release is reduced in CNS of syntaxin1A null mutant mice (STX1A KO). Unusual social behavior was observed in STX1A KO. We found that oxytocin (OXT) release, which was stimulated by DA, was reduced and was rescued the unusual social behavior in STX1A KO was rescued by OXT. These results indicated that STX1A plays an important role in promoting social behavior through regulation of DA-induced OXT release in amygdala. © 2016 International Society for Neurochemistry.

The Experimental Determination of Safe Atmospheric Exposure Concentrations of JP-10 Jet Fuel

DTIC Science & Technology

1985-11-01

adrenocortical adenoma was seen in another male control. An adrenal pheochromocytoma was observed in an exposed female dog and was the only neoplasm recorded in...Postexposure." Several unusual trends in the incidence of non-neoplastic lesions are evident in the table; however, most were regarded as sponta- neous

An unusual case of diffuse Merkel cell carcinoma successfully treated with low dose radiotherapy.

PubMed

Chatzinasiou, Foteini; Papadavid, Euaggelia; Korkolopoulou, Penelope; Levidou, Georgia; Panayiotides, Ioannis; Theodoropoulos, Konstadinos; Pogka, Vasiliki; Asimakopoulos, Charalampos; Rigopoulos, Dimitrios

2015-01-01

Merkel cell carcinoma (MCC) is a rare and highly aggressive neuroendocrine carcinoma of the skin. MCC should be included in the diagnosis of a rapidly growing infiltrating mass and histology as well as laboratory investigations such as Merkel cell polyoma virus (MCPyV) detection are valuable in its diagnosis. We present an unusual case of giant MCC-positive MCPyV in a Greek woman located on the lower leg. Our patient is very unusual in terms of her extensive MCC and her rapid and complete response to radiotherapy. © 2015 Wiley Periodicals, Inc.

An episode of extremely high PM concentrations over Central Europe caused by dust emitted over the southern Ukraine

NASA Astrophysics Data System (ADS)

Birmili, W.; Schepanski, K.; Ansmann, A.; Spindler, G.; Tegen, I.; Wehner, B.; Nowak, A.; Reimer, E.; Mattis, I.; Müller, K.; Brüggemann, E.; Gnauk, T.; Herrmann, H.; Wiedensohler, A.; Althausen, D.; Schladitz, A.; Tuch, T.; Löschau, G.

2007-08-01

On 24 March 2007, the atmosphere over Central Europe was affected by an episode of exceptionally high mass concentrations of aerosol particles, most likely caused by a dust storm in the Southern Ukraine on the preceding day. At ground-based measurement stations in Slovakia, the Czech Republic, Poland and Germany PM10 mass concentrations rose to values between 200 and 1400 μg m-3. An evaluation of PM10 measurements from 360 monitoring stations showed that the dust cloud advanced along a narrow corridor at speeds of up to 70 km h-1. According to lidar observations over Leipzig, Germany, the high aerosol concentrations were confined to a homogeneous boundary layer of 1800 m height. The wavelength dependence of light extinction using both lidar and sun photometer measurements suggested the dominance of coarse particles during the main event. At a wavelength of 532 nm, relatively high volume extinction coefficients (300-400 Mm-1) and a particle optical depth of 0.65 was observed. In-situ measurements with an aerodynamic particle sizer at Melpitz, Germany, confirmed the presence of a coarse particle mode with a mode diameter >2 μm, whose maximum concentration coincided with that of PM10. A chemical particle analysis confirmed the dominance of non-volatile and insoluble matter in the coarse mode as well as high enrichments of Ti and Fe, which are characteristic of soil dust. A combination of back trajectory calculations and satellite images allowed to identify the dust source with confidence: On 23 March 2007, large amounts of dust were emitted from dried-out farmlands in the southern Ukraine, facilitated by wind gusts up to 100 km h-1. The unusual vertical stability and confined height of this dust layer as well as the rapid transport under dry conditions led to the conservation of high aerosol mass concentrations along the transect and thus to the extraordinary high aerosol concentrations over Central Europe. Our observations demonstrate the capacity of a combined apparatus of in situ and remote sensing measurements to characterise such a dust with a variety of aerosol parameters. As a conclusion, the description of dust emission, transport and transformation processes needs to be improved, especially when facing the possible effects of further anthropogenic desertification and climate change.

Fatigue mechanisms in patients with cancer: effects of tumor necrosis factor and exercise on skeletal muscle

NASA Technical Reports Server (NTRS)

St Pierre, B. A.; Kasper, C. E.; Lindsey, A. M.

1992-01-01

Fatigue is a common adverse effect of cancer and its therapy. However, the specific mechanisms underlying cancer fatigue are unclear. One physiologic mechanism may involve changes in skeletal muscle protein stores or metabolite concentration. A reduction in skeletal muscle protein stores may result from endogenous tumor necrosis factor (TNF) or from TNF administered as antineoplastic therapy. This muscle wasting would require patients to exert an unusually high amount of effort to generate adequate contractile force during exercise performance or during extended periods of sitting or standing. This additional effort could result in the onset of fatigue. Additionally, cancer fatigue may develop or become exacerbated during exercise as a consequence of changes in the concentration of skeletal muscle metabolites. These biochemical alterations may interfere with force that is produced by the muscle contractile proteins. These physiologic changes may play a role in the decision to include exercise in the rehabilitation plans of patients with cancer. They also may affect ideas about fatigue.

“Breakthrough” osmosis and unusually high power densities in Pressure-Retarded Osmosis in non-ideally semi-permeable supported membranes

PubMed Central

Yaroshchuk, Andriy

2017-01-01

Osmosis is the movement of solvent across a membrane induced by a solute-concentration gradient. It is very important for cell biology. Recently, it has started finding technological applications in the emerging processes of Forward Osmosis and Pressure-Retarded Osmosis. They use ultrathin and dense membranes supported mechanically by much thicker porous layers. Until now, these processes have been modelled by assuming the membrane to be ideally-semipermeable. We show theoretically that allowing for even minor deviations from ideal semipermeability to solvent can give rise to a previously overlooked mode of “breakthrough” osmosis. Here the rate of osmosis is very large (compared to the conventional mode) and practically unaffected by the so-called Internal Concentration Polarization. In Pressure-Retarded Osmosis, the power densities can easily exceed the conventional mode by one order of magnitude. Much more robust support layers can be used, which is an important technical advantage (reduced membrane damage) in Pressure-Retarded Osmosis. PMID:28332607

Multiple spike initiation zones in a neuron implicated in learning in the leech: a computational model.

PubMed

Crisp, Kevin M

2009-03-01

Sensitization of the defensive shortening reflex in the leech has been linked to a segmentally repeated tri-synaptic positive feedback loop. Serotonin from the R-cell enhances S-cell excitability, S-cell impulses cross an electrical synapse into the C-interneuron, and the C-interneuron excites the R-cell via a glutamatergic synapse. The C-interneuron has two unusual characteristics. First, impulses take longer to propagate from the S soma to the C soma than in the reverse direction. Second, impulses recorded from the electrically unexcitable C soma vary in amplitude when extracellular divalent cation concentrations are elevated, with smaller impulses failing to induce synaptic potentials in the R-cell. A compartmental, computational model was developed to test the sufficiency of multiple, independent spike initiation zones in the C-interneuron to explain these observations. The model displays asymmetric delays in impulse propagation across the S-C electrical synapse and graded impulse amplitudes in the C-interneuron in simulated high divalent cation concentrations.

Simultaneous organic nitrogen and sulfate removal in an anaerobic GAC fluidised bed reactor.

PubMed

Fdz-Polanco, F; Fdz-Polanco, M; Fernandez, N; Urueña, M A; García, P A; Villaverde, S

2001-01-01

A granular activated carbon (GAC) anaerobic fluidised bed reactor treating vinasse from an ethanol distillery of sugar beet molasses was operated for 250 days under three different organic loading rates. The reactor showed good performance in terms of organic matter removal and methane production but an anomalous behaviour in terms of unusual high concentrations of molecular nitrogen and low concentration of hydrogen sulphide in the biogas. The analysis of the different nitrogenous and sulphur compounds and the mass balances of these species in the liquid and gas phases clearly indicated an uncommon evolution of nitrogen and sulphur in the reactor. Up to 55% of the TKN and up to 80% of the sulphur disappear in the liquid phase. This is the opposite to any previously reported results in the bibliography. The new postulated anaerobic process of ammonia and sulphate removal seems to follow the mechanism: SO4 = +2 NH4+-->S + N2 + 4H2O (delta G degree = -47.8 kJ/mol).

Complex reassortment events of unusual G9P[4] rotavirus strains in India between 2011 and 2013.

PubMed

Doan, Yen Hai; Suzuki, Yoshiyuki; Fujii, Yoshiki; Haga, Kei; Fujimoto, Akira; Takai-Todaka, Reiko; Someya, Yuichi; Nayak, Mukti K; Mukherjee, Anupam; Imamura, Daisuke; Shinoda, Sumio; Chawla-Sarkar, Mamta; Katayama, Kazuhiko

2017-10-01

Rotavirus A (RVA) is the predominant etiological agent of acute gastroenteritis in young children worldwide. Recently, unusual G9P[4] rotavirus strains emerged with high prevalence in many countries. Such intergenogroup reassortant strains highlight the ongoing spread of unusual rotavirus strains throughout Asia. This study was undertaken to determine the whole genome of eleven unusual G9P[4] strains detected in India during 2011-2013, and to compare them with other human and animal global RVAs to understand the exact origin of unusual G9P[4] circulating in India and other countries worldwide. Of these 11 RVAs, four G9P[4] strains were double-reassortants with the G9-VP7 and E6-NSP4 genes on a DS-1-like genetic backbone (G9-P[4]-I2-R2-C2-M2-A2-N2-T2-E6-H2). The other strains showed a complex genetic constellation, likely derived from triple reassortment event with the G9-VP7, N1-NSP2 and E6-NSP4 on a DS-1-like genetic backbone (G9-P[4]-I2-R2-C2-M2-A2-N1-T2-E6-H2). Presumably, these unusual G9P[4] strains were generated after several reassortment events between the contemporary co-circulating human rotavirus strains. Moreover, the point mutation S291L at the interaction site between inner and outer capsid proteins of VP6 gene may be important in the rapid spread of this unusual strain. The complex reassortment events within the G9[4] strains may be related to the high prevalence of mixed infections in India as reported in this study and other previous studies. Copyright © 2017. Published by Elsevier B.V.

The Intrinsically X-Ray-weak Quasar PHL 1811. II. Optical and UV Spectra and Analysis

NASA Astrophysics Data System (ADS)

Leighly, Karen M.; Halpern, Jules P.; Jenkins, Edward B.; Casebeer, Darrin

2007-11-01

This is the second of two papers reporting observations and analysis of the unusually bright (mb=14.4), luminous (MB=-25.5), nearby (z=0.192) narrow-line quasar PHL 1811. The first paper reported that PHL 1811 is intrinsically X-ray-weak and presented a spectral energy distribution (SED). Here we present HST STIS optical and UV spectra, and ground-based optical spectra. The optical and UV line emission is very unusual. There is no evidence for forbidden or semiforbidden lines. The near-UV spectrum is dominated by very strong Fe II and Fe III, and unusual low-ionization lines such as Na I D and Ca II H and K are observed. High-ionization lines are very weak; C IV has an equivalent width of 6.6 Å, a factor of ~5 smaller than measured from quasar composite spectra. An unusual feature near 1200 Å can be deblended in terms of Lyα, N V, Si II, and C III* using the blueshifted C IV profile as a template. Photoionization modeling shows that the unusual line emission can be explained qualitatively by the unusually soft SED. Principally, a low gas temperature results in inefficient emission of collisionally excited lines, including the semiforbidden lines generally used as density diagnostics. The emission resembles that of high-density gas; in both cases this is a consequence of inefficient cooling. PHL 1811 is very unusual, but we note that quasar surveys may be biased against finding similar objects. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. These observations are associated with proposal 9181. Based on observations obtained at Kitt Peak National Observatory, a division of the National Optical Astronomy Observatories, which is operated by the Association of Universities for Research in Astronomy, Inc., under cooperative agreement with the National Science Foundation.

Distribution of radionuclide and trace-elements in ground water, grasses, and surficial sediments associated with the alluvial aquifer along the Puerco River, northeastern Arizona; a reconnaissance sampling program

USGS Publications Warehouse

Webb, R.H.; Rink, G.R.; Favor, B.O.

1987-01-01

The concentrations of gross alpha radioactivity minus uranium equaled or exceeded 15 picoCuries/L (pCi/L) in five of 14 wells sampled. The concentration of radium-226 plus radium-228 exceeded the primary water quality standard of 5 pCi/L in one well. The concentration of uranium exceeded a recommended limit of 0.035 mg/L in two wells. Perennial grass and sediment samples had low concentrations of radionuclides. The concentration of trace elements in the sediment samples was not unusual. Water quality of surface water in the Puerco River at Chambers varied as a function of the suspended sediment concentration. Concentrations of total gross alpha radiation fluctuated from 12 to 11,200 pCi/L. Concentrations of total gross beta radiation fluctuated from 45 to 4,500 pCi/L. (Author 's abstract)

Orthostatic hypotension as an unusual clinical manifestation of pheochromocytoma: a case report.

PubMed

Bortnik, Miriam; Occhetta, Eraldo; Marino, Paolo

2008-08-01

Pheochromocytoma is a rare endocrine tumor which can have a highly variable presentation related to increased catecholamine secretion. We report the case of a 74-year-old man in whom recurrent episodes of syncope due to orthostatic hypotension were the only clinical manifestations of this challenging entity. Diagnosis of pheochromocytoma was achieved by biochemical test samples and computed tomography scans. Surgical excision of the tumor resulted in clinical improvement with normalization of catecholamine concentrations and no more episodes of orthostatic hypotension during a follow-up of 24 months. Although rare, pheochromocytoma may frequently cause disorders of orthostatic tolerance; because of its meaningful implications, screening for this entity should be considered in case of recurrent syncopal episodes due to new-onset orthostatic hypotension.

Production and Characterization of a Polymer from Arthrobacter sp.

PubMed

Bodie, E A; Schwartz, R D; Catena, A

1985-09-01

An Arthrobacter sp. isolated from a glucose-sucrose agar plate was found to produce a neutral, extremely viscous, opalescent extracellular polymer. Growth, polymer production, and rheological properties and chemical composition of the isolated polymer were examined. The polymer was found to be substantially different from other arthrobacter polymers. Some unusual properties included irreversible loss of viscosity with high temperature and degradation of the polymer during fermentation and upon storage at 4 degrees C. Other characteristics included dependence on sucrose for polymer production, relative pH stability, increased viscosity with increased salt concentration, and pseudoplasticity. The polymer was found to be composed primarily (if not entirely) of d-fructose. The fructose content and other characteristics suggested that the polymer was a levan.

Production and Characterization of a Polymer from Arthrobacter sp

PubMed Central

Bodie, Elizabeth A.; Schwartz, Robert D.; Catena, Anthony

1985-01-01

An Arthrobacter sp. isolated from a glucose-sucrose agar plate was found to produce a neutral, extremely viscous, opalescent extracellular polymer. Growth, polymer production, and rheological properties and chemical composition of the isolated polymer were examined. The polymer was found to be substantially different from other arthrobacter polymers. Some unusual properties included irreversible loss of viscosity with high temperature and degradation of the polymer during fermentation and upon storage at 4°C. Other characteristics included dependence on sucrose for polymer production, relative pH stability, increased viscosity with increased salt concentration, and pseudoplasticity. The polymer was found to be composed primarily (if not entirely) of d-fructose. The fructose content and other characteristics suggested that the polymer was a levan. PMID:16346883

Reflecting on My Progressive Education

ERIC Educational Resources Information Center

Friend, Nina

2012-01-01

At the end of the 2011-12 version of the project course Schools Across Borders, Schools Across Time (SABSAT), a high school senior wrote a series of letters reflecting on the experience of participating in an unusual course with an unusual outcome. In the letters, the student wanted to evoke what was personal and what was critical--to herself, her…

An unusual reaction of α-alkoxyphosphonium salts with Grignard reagents under an O2 atmosphere.

PubMed

Fujioka, Hiromichi; Goto, Akihiro; Otake, Kazuki; Kubo, Ozora; Sawama, Yoshinari; Maegawa, Tomohiro

2011-09-21

An unusual and novel reaction of α-alkoxyphosphonium salts, generated from O,O-acetals and Ph(3)P, with Grignard reagents under an O(2) atmosphere afforded alcohols in moderate to high yields. It was clarified by isotopic labelling experiments that the reaction proceeded via a novel radical pathway.

Copper-Catalyzed Heteroarylboration of 1,3-Dienes with 3-Bromopyridines: A cine Substitution.

PubMed

Smith, Kevin B; Huang, Yuan; Brown, M Kevin

2018-04-26

A method for the heteroarylboration of 1,3-dienes is presented. The process involves an unusual cine substitution of 3-bromopyridine derivatives to deliver highly functionalized heterocyclic products. Mechanistic studies are included that clarify the details of this unusual process. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Unusual MR spectroscopic imaging pattern of an astrocytoma: lack of elevated choline and high myo-inositol and glycine levels.

PubMed

Londoño, Ana; Castillo, Mauricio; Armao, Diane; Kwock, Lester; Suzuki, Kinuko

2003-05-01

We present the case of a patient with an MR imaging study showing an ill-defined intra-axial mass in the right insula and frontal lobe. The mass showed high signal intensity on T2-weighted and fluid-attenuated inversion recovery images and an unusual proton MR spectroscopic imaging pattern characterized by the presence of high levels of myo-inositol/glycine, no significant elevation of choline, and mildly reduced N-acetylaspartate. The histopathologic diagnosis was of diffuse astrocytoma with oligodendroglial components (World Health Organization grade II).

The impact of water on dislocation content and slip system activity in olivine constrained by HR-EBSD and visco-plastic self-consistent simulations

NASA Astrophysics Data System (ADS)

Wallis, D.; Hansen, L. N.; Tasaka, M.; Kumamoto, K. M.; Lloyd, G. E.; Parsons, A. J.; Kohlstedt, D. L.; Wilkinson, A. J.

2016-12-01

Changes in concentration of H+ ions in olivine have impacts on its rheological behaviour and therefore on tectonic processes involving mantle deformation. Deformation experiments on aggregates of wet olivine exhibit different evolution of crystal preferred orientations (CPO) and substructure from experiments on dry olivine, suggesting that elevated H+ concentrations impact activity of dislocation slip-systems. We use high angular-resolution electron backscatter diffraction (HR-EBSD) to map densities of different types of geometrically necessary dislocations (GND) in polycrystalline olivine deformed experimentally under wet and dry conditions and also in nature. HR-EBSD provides unprecedented angular resolution, resolving misorientations < 0.01°. We also employ visco-plastic self-consistent (VPSC) simulations to investigate changes in slip-system activity. HR-EBSD maps from experimental samples demonstrate that olivine deformed under hydrous conditions contains higher proportions of (001)[100] and (100)[001] edge dislocations than olivine deformed under anhydrous conditions. Furthermore, maps of wet olivine exhibit more polygonal subgrain boundaries indicative of enhanced recovery by dislocation climb. VPSC simulations with low critical resolved shear stresses for the (001)[100] and (100)[001] slip systems reproduce an unusual CPO with bimodal maxima of both [100] and [001] observed in wet olivine aggregates. Analysis of a mylonitic lherzolite xenolith from Lesotho reveals the same unusual CPO and similar proportions of dislocation types to `wet' experimental samples, supporting the applicability of these findings to natural deformation conditions. These results support suggestions that H+ impacts the flow properties of olivine by altering dislocation activity and climb, while also providing full quantification of GND content. In particular, the relative proportions of dislocation types may provide a basis for identifying olivine deformed under wet and dry conditions.

Adverse Reactions to Zolpidem: Case Reports and a Review of the Literature

PubMed Central

Miyaoka, Tsuyoshi; Tsuji, Seiichi; Inami, Yasushi; Nishida, Akira; Horiguchi, Jun

2010-01-01

Objective: Zolpidem, a nonbenzodiazepine hypnotic, is very effective and widely prescribed in clinical practice for the treatment of insomnia and is thought to have few adverse effects. However, zolpidem-induced adverse effects have begun to be reported in the literature, but few systemic descriptions of the adverse effects (especially for psychotic reactions) of zolpidem have been undertaken. In light of the accumulating reports of adverse reactions to zolpidem, we present 2 case reports of zolpidem-induced adverse effects and review the literature on this subject. Data Sources: Articles were selected by the authors on the basis of our experience and by a PubMed search using the terms zolpidem or side effects or adverse effects or adverse reactions. Study Selection and Data Extraction: Publications relevant to the objective of this article were obtained (1992–2010), and some adverse neuropsychiatric reactions were summarized. Data Synthesis: Zolpidem has been associated with the development of adverse neuropsychiatric reactions, such as hallucinations/sensory distortion, amnesia, sleepwalking/somnambulism, and nocturnal eating. The following 4 variables should be considered when prescribing zolpidem: (1) gender: women have been found to have a significantly higher serum zolpidem concentration than men; (2) zolpidem dose: the adverse reactions that develop are dose dependent; (3) protein binding affinity: a high proportion of zolpidem is protein bound; therefore, low serum albumin results in a higher level of free zolpidem leading to adverse psychiatric reactions; and (4) cytochrome P450 (CYP) isoenzyme inhibition: concomitant administration of zolpidem and other drugs may cause interactions that lead to increased concentrations of zolpidem. Conclusions: Zolpidem is clinically very effective in treating insomnia. However, while rare, zolpidem-induced unusual complex behavior may develop. Primary care physicians should be alert to the possible unusual complex adverse effects of zolpidem. PMID:21494350

Self-regulation mechanism for charged point defects in hybrid halide perovskites

DOE PAGES

Walsh, Aron; Scanlon, David O.; Chen, Shiyou; ...

2014-12-11

Hybrid halide perovskites such as methylammonium lead iodide (CH 3NH 3PbI 3) exhibit unusually low free-carrier concentrations despite being processed at low-temperatures from solution. We demonstrate, through quantum mechanical calculations, that an origin of this phenomenon is a prevalence of ionic over electronic disorder in stoichiometric materials. Schottky defect formation provides a mechanism to self-regulate the concentration of charge carriers through ionic compensation of charged point defects. The equilibrium charged vacancy concentration is predicted to exceed 0.4 % at room temperature. Furthermore, this behavior, which goes against established defect conventions for inorganic semiconductors, has implications for photovoltaic performance.

Recall of false memories in individuals scoring high in schizotypy: memory distortions are scale specific.

PubMed

Saunders, Jo; Randell, Jordan; Reed, Phil

2012-06-01

Previous research has indicated abnormal semantic activation in individuals scoring higher in schizotypy. In the current experiment, semantic activation was examined by using the Deese-Roediger-McDermott paradigm of false memories. Participants were assessed for schizotypy using the Oxford-Liverpool Inventory of Feelings (OLIFE). Participants studied lists of semantically related words in which a critical and highly associated word was absent. Participants then recalled the list. Participants high in Unusual Experiences and Cognitive Disorganization recalled more critical non-presented words, weakly related studied words, and fewer studied words than participants who scored low on these measures. Previous research using the cognitive-perceptual factor of the Schizotypy Personality Questionnaire found reduced false memories, while the Unusual Experiences subscale of the OLIFE was associated with more false memories. Both scales cover similar unusual perceptual experiences and it is unclear why they led to divergent results. The findings suggest that subtypes of schizotypy are associated with abnormal semantic activation. Copyright © 2011 Elsevier Ltd. All rights reserved.

Mycotoxins and cyanogenic glycosides in staple foods of three indigenous people of the Colombian Amazon.

PubMed

Diaz, Gonzalo J; Krska, Rudolf; Sulyok, Michael

2015-01-01

A study was conducted to determine the incidence and levels of mycotoxins in the main staple foods of three indigenous people of the Colombian Amazon. A total of 20 corn, 24 rice and 59 cassava samples were analysed by a multi-analyte liquid chromatography-tandem mass spectrometry method covering the major classes of mycotoxins. In addition, cassava samples were also analysed for cyanogenic glycosides. The indigenous Amazon communities tested are exposed to potentially carcinogenic mycotoxins (particularly aflatoxins), as well as other mycotoxins, mainly through the intake of locally grown corn. Citrinin content in this corn was unusually high and has not been reported elsewhere. Two cassava samples contained high levels of cyanogenic glycosides. It is strongly recommended not to grow corn in the Amazon but instead purchase it from vendors capable of guaranteeing mycotoxin levels below the maximum allowable concentration in Colombia.

A SIMS study of lunar 'komatiitic glasses' - Trace element characteristics and possible origin

NASA Technical Reports Server (NTRS)

Shearer, C. K.; Papike, J. J.; Galbreath, K. C.; Wentworth, S. J.; Shimizu, N.

1990-01-01

In Apollo 16 regolith breccias, Wentworth and McKay (1988) identified a suite of minute (less than 120 microns) 'komatiitic glass beads'. The wide major element compositional range, and ultra-Mg-prime character of the glasses suggest a variety of possible origins from complex impact processes to complex volcanic processes involving rather unusual and primitive magmatism. The extent of trace element depletion or enrichment in these glasses appears to be correlated to the siderophile character of the element (ionization potential or experimentally determined silicate melt/Fe metal partition coefficients. The ultra-Mg-prime glasses are depleted in Co relative to a bulk Moon Mg/Co exhibited by many lunar samples (volcanic glasses, basalts, regolith breccia, estimated upper mantle). The low Co and high incompatible element concentrations diminish the possibility that these glasses are a product of lunar komatiitic volcanism or impact, excavation, and melting of a very high Mg-prime plutonic unit.

Elevated fat skatole levels in immunocastrated, surgically castrated and entire male pigs with acute dysentery.

PubMed

Skrlep, Martin; Batorek, Nina; Bonneau, Michel; Fazarinc, Gregor; Segula, Blaž; Candek-Potokar, Marjeta

2012-12-01

Boar taint is due to androstenone and skatole (3-methyl-indole) accumulation in fat tissues. During a study to investigate the effect of immunocastration on fattening pigs, an outbreak of acute dysentery occurred caused by Lawsonia intracellularis and Brachyspira hyodysenteriae and resulted in cachexia and high mortality. Low androstenone levels in the immunocastrates (0.25 ± 0.04 μg/g liquid fat) suggested that the immunocastration had been effective, but unusually high skatole concentrations in fat tissues were found not only in entire males, but also in surgical castrates and immunocastrates (0.22 ± 0.15, 0.14 ± 0.08 and 0.18 ± 0.14 μg/g liquid fat, respectively). The findings suggest that boar taint can arise in cases of intestinal infections, even in castrated pigs. Copyright © 2012 Elsevier Ltd. All rights reserved.

Therapeutic drug monitoring and the conservative management of chronic tuberculous empyema: case report and review of the literature.

PubMed

Long, Richard; Barrie, James; Peloquin, Charles A

2015-08-12

Chronic tuberculous empyema (CTE) is a rare and unusual, low grade and protracted, infection of the pleural space resulting in marked thickening, even calcification of the visceral and parietal pleura. Historically its management has been extraordinarily challenging. Differential penetration of anti-TB drugs into the pleural space has resulted in acquired drug resistance and surgery to remove the empyema or close a complicating bronchopleural fistula (BPF) has been technically difficult or unacceptably hazardous. On the basis of limited experience, the combination of tube thoracostomy or catheter drainage and high-end dosing of anti-TB drugs has been recommended as an initial approach to these lesions. Herein we report the first well documented case of closure of a BPF and cure of a CTE using this approach. The chances of a favorable outcome are improved, we suggest, by using therapeutic drug monitoring (TDM) to guide high-end drug dosing. An 84 year old male immigrant to Canada from Croatia was diagnosed with a CTE after he developed a BPF. The diagnosis was made 62 years after what was, in retrospect, an episode of tuberculous pleurisy. He was treated with computed tomography-guided catheter drainage and TDM-guided high-end dosed anti-TB drugs (serum and pleural fluid drug concentrations) over a 10 month period. Sustained closure of the BPF and mycobacteriologic cure of the CTE was achieved. Drug concentrations in the present case and all other reported cases are summarized and interpreted. When serum concentrations of the anti-TB drugs isoniazid, pyrazinamide and ethambutol at the high end of the normal range are achieved, pleural fluid concentrations at the low end of the normal range may be anticipated in CTE. Though highly protein bound drugs such as rifampin and moxifloxacin appear to penetrate CTEs less well, their free concentrations in the pleural space may be proportionately higher on account of lower protein concentrations. Interventional radiology and TDM increase the chances that conservative management of CTE will be successful.

Low-intensity red and infrared laser effects at high fluences on Escherichia coli cultures

PubMed Central

Barboza, L.L.; Campos, V.M.A.; Magalhães, L.A.G.; Paoli, F.; Fonseca, A.S.

2015-01-01

Semiconductor laser devices are readily available and practical radiation sources providing wavelength tenability and high monochromaticity. Low-intensity red and near-infrared lasers are considered safe for use in clinical applications. However, adverse effects can occur via free radical generation, and the biological effects of these lasers from unusually high fluences or high doses have not yet been evaluated. Here, we evaluated the survival, filamentation induction and morphology of Escherichia coli cells deficient in repair of oxidative DNA lesions when exposed to low-intensity red and infrared lasers at unusually high fluences. Cultures of wild-type (AB1157), endonuclease III-deficient (JW1625-1), and endonuclease IV-deficient (JW2146-1) E. coli, in exponential and stationary growth phases, were exposed to red and infrared lasers (0, 250, 500, and 1000 J/cm2) to evaluate their survival rates, filamentation phenotype induction and cell morphologies. The results showed that low-intensity red and infrared lasers at high fluences are lethal, induce a filamentation phenotype, and alter the morphology of the E. coli cells. Low-intensity red and infrared lasers have potential to induce adverse effects on cells, whether used at unusually high fluences, or at high doses. Hence, there is a need to reinforce the importance of accurate dosimetry in therapeutic protocols. PMID:26445339

Chance Encounter with a Stratospheric Kerosene Rocket Plume from Russia over California

NASA Technical Reports Server (NTRS)

Newman, P. A.; Wilson, J. C.; Ross, M. N.; Brock, C.; Sheridan, P.; Schoeberl, M. R.; Lait, L. R.; Bui, T. P.; Loewenstein, M.

1999-01-01

During a routine ER-2 aircraft high-altitude test flight on April 18, 1997, an unusual aerosol cloud was detected at 20 km altitude near the California coast at about 370 degrees N latitude. Not visually observed by the ER-2 pilot, the cloud was characterized bv high concentration of soot and sulfate aerosol in a region over 100 km in horizontal extent indicating that the source of the plume was a large hydrocarbon fueled vehicle, most likely a launch vehicle powered only by rocket motors burning liquid oxygen and kerosene. Two Russian Soyuz rockets could conceivably have produced the plume. The first was launched from the Baikonur Cosmodrome, Kazakhstan on April 6th; the second was launched from Plesetsk, Russia on April 9. Air parcel trajectory calculations and long-lived tracer gas concentrations in the cloud indicate that the Baikonur rocket launch is the most probable source of the plume. The parcel trajectory calculations do not unambiguously trace the transport of the Soyuz plume from Asia to North America, illustrating serious flaws in the point-to-point trajectory calculations. This chance encounter represents the only measurement of the stratospheric effects of emissions from a rocket powered exclusively with hydrocarbon fuel.

Bullous phytophotodermatitis associated with high natural concentrations of furanocoumarins in limes.

PubMed

Wagner, Annette M; Wu, Jashin J; Hansen, Ronald C; Nigg, Herbert N; Beiere, Ross C

2002-03-01

Phytophotodermatitis is a phototoxic reaction, occurring in skin exposed to sunlight after contact with plants containing furanocoumarins. Typical reactions are mild, showing erythema with post-inflammatory hyperpigmentation. A 6-year-old boy presented with marked, symmetric, painful erythema and edema of both hands that rapidly developed into dramatic bullae covering the entire dorsum of the hands. The history revealed that the hands had been bathed in lime juice for a prolonged period in the preparation of limeade. This report documents an unusual bullous presentation of phytophotodermatitis resulting from contact with furanocoumarins in local limes. This study was conducted to identify and measure the inciting substances from the rind and pulp of the limes. Psoralen, xanthotoxin, bergapten, and isopimpinellin content were measured by gas chromatography and high-pressure liquid chromatography The rind contained 6- to 182-fold concentrations of all furanocoumarins measured when compared with pulp. Bergapten was the most abundant substance in the rind. Hydration of the skin during the preparation of limeade combined with increased levels of bergapten in local limes to produce a dramatic bullous reaction. We encourage clinicians to consider the possibility of phytophotodermatitis in severe bullous skin reactions. Copyright 2002, Elsevier Science (USA). All rights reserved.

A graphical method for determining the dry-depositional component of aerosol samples and their field blanks

NASA Astrophysics Data System (ADS)

Huang, Suilou; Rahn, Kenneth A.; Arimoto, Richard

During the Atmosphere/Ocean Chemistry Experiment (AEROCE), field blanks of certain elements in aerosol samples occasionally increased abruptly, always during periods of unusually high atmospheric concentrations. We hypothesized that the anomalous blanks were created by coarse aerosol entering the sampling shelters and depositing onto the blank filters. If so, samples taken nearby should have been similarly affected. To test this hypothesis, we developed a simple graphical method in which elemental masses in field blanks are plotted against elemental masses in pumped samples, and zones of proportionality between the two are sought. Data from Bermuda and Mace Head (coastal western Ireland) confirmed that depositional zones did indeed appear, but only for coarse-particle elements and only under certain conditions. Actual increases of crustal and pollution-derived elements agreed well with values predicted from settling velocities and sampling rates: blanks increased up to an order of magnitude or more but samples by less than 1%. Marine elements behaved like crustal elements in most samples but occasionally were much more enriched: blanks increased up to 30-fold and samples up to about 3%. It thus appears that when coarse-particle elements are present in high concentrations, their field blanks and samples may be measurably affected by dry deposition. Depending on the elements of interest, this dry deposition may have to be measured and the concentrations corrected.

Whole-body concentrations of elements in three fish species from offshore oil platforms and natural areas in the Southern California Bight, USA

USGS Publications Warehouse

Love, Milton S.; Saiki, Michael K.; May, Thomas W.; Yee, Julie L.

2013-01-01

elements. Forty-two elements were excluded from statistical comparisons as they (1) consisted of major cations that were unlikely to accumulate to potentially toxic concentrations; (2) were not detected by the analytical procedures; or (3) were detected at concentrations too low to yield reliable quantitative measurements. The remaining 21 elements consisted of aluminum, arsenic, barium, cadmium, chromium, cobalt, copper, gallium, iron, lead, lithium, manganese, mercury, nickel, rubidium, selenium, strontium, tin, titanium, vanadium, and zinc. Statistical comparisons of these elements indicated that none consistently exhibited higher concentrations at oil platforms than at natural areas. However, the concentrations of copper, selenium, titanium, and vanadium in Pacific sanddab were unusual because small individuals exhibited either no differences between oil platforms and natural areas or significantly lower concentrations at oil platforms than at natural areas, whereas large individuals exhibited significantly higher concentrations at oil platforms than at natural areas.

Chemical residues in Dolphins from the US Atlantic coast including atlantic bottlenose obtained during the 1987/88 mass mortality

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuehl, D.W.; Haebler, R.; Potter, C.

1991-01-01

Bottlenose dolphins (Tursiops truncatus) collected during the 1987/88 mass mortality event along the Atlantic coast of the United States have been analyzed for anthropogenic chemical contaminants. Average contaminant concentrations in adult males were higher than the average concentrations measured in adult females. Females could be divided into two groups by contaminant concentrations, one with low concentrations, and another with concentrations 4.4 times (PCBs) to 8.9 times (p,p'-DDE) greater. Contaminant concentrations in bottlenose were generally greater than the concentrations measured in either common (Delphinus delphis) or white-sided (Lagernorhynchus acutus) dolphins from the western North Atlantic Ocean. A subset of animals screenedmore » for unusual chemical contaminants showed that numerous polybrominated chemicals were present, including polybrominated biphenyls and diphenyl ethers not previously found in marine mammals from U.S. coastal waters.« less

With an Unusually Hands-On Role, State Feels Its Way in New Orleans

ERIC Educational Resources Information Center

Robelen, Erik W.

2006-01-01

This article reports how Louisiana officials take hits amid strain to start schools. A year after Hurricane Katrina wreaked havoc on New Orleans, the state of Louisiana finds itself in the highly unusual position of essentially starting from scratch--and directly operating--a batch of public schools in the city. While much attention has focused on…

Anatomy Adventure: A Board Game for Enhancing Understanding of Anatomy

ERIC Educational Resources Information Center

Anyanwu, Emeka G.

2014-01-01

Certain negative factors such as fear, loss of concentration and interest in the course, lack of confidence, and undue stress have been associated with the study of anatomy. These are factors most often provoked by the unusually large curriculum, nature of the course, and the psychosocial impact of dissection. As a palliative measure, Anatomy…

Suggestive, Accelerative Learning and Teaching: A Manual of Classroom Procedures Based on the Lozanov Method.

ERIC Educational Resources Information Center

Schuster, Donald H.; And Others

The Suggestive Accelerative Learning and Teaching Method uses aspects of suggestion and unusual styles of presenting material to accelerate classroom learning. The essence of this technique is the use of a combination of physical relaxation exercises, mental concentration and suggestive principles to strengthen a person's ego and expand his memory…

Planned complex suicide: an unusual case.

PubMed

Pélissier-Alicot, Anne-Laure; Gavaudan, Gilles; Bartoli, Christophe; Kintz, Pascal; Piercecchi-Marti, Marie-Dominique; Desfeux, Jacques; Leonetti, Georges

2008-07-01

We report an unusual case of planned complex suicide. The victim was a woman aged 67 years, who was found dead in her bath in a state of advanced putrefaction. A plugged-in hairdryer was submerged in the water and the electrical fuses in the room had short-circuited. A kitchen knife lay below the body of the victim, whose left forearm bore incisions suggestive of wrist-cutting. At autopsy, no sign suggesting electrocution could be observed because of the advanced state of putrefaction of the body. Toxicological analysis revealed massive ingestion of tianeptine (blood concentration 15.5 mg/L). Although the exact cause of death could not be determined because of the state of the corpse, meticulous examination of the scene and information obtained from the victim's relatives led to the conclusion of suicide.

Gas chromatography-mass spectrometry profiles of urinary organic acids in healthy captive cheetahs (Acinonyx jubatus).

PubMed

Tordiffe, Adrian Stephen Wolferstan; van Reenen, Mari; Reyers, Fred; Mienie, Lodewyk Jacobus

2017-04-01

In captivity, cheetahs (Acinonyx jubatus) frequently suffer from several unusual chronic diseases that rarely occur in their free-ranging counterparts. In order to develop a better understanding of their metabolism and health we documented the urine organic acids of 41 apparently healthy captive cheetahs, in an untargeted metabolomic study, using gas chromatography-mass spectrometry. A total of 339 organic acids were detected and annotated. Phenolic compounds, thought to be produced by the anaerobic fermentation of aromatic amino acids in the distal colon, as well as their corresponding glycine conjugates, were present in high concentrations. The most abundant organic acids in the cheetahs' urine were an as yet unidentified compound and a novel cadaverine metabolite, tentatively identified as N 1 ,N 5 -dimethylpentane-1,5-diamine. Pantothenic acid and citramalic acid concentrations correlated negatively with age, while glutaric acid concentrations correlated positively with age, suggesting possible dysregulation of coenzyme A metabolism in older cheetahs. This study provides a baseline of urine organic acid reference values in captive cheetahs and suggests important avenues for future research in this species. Copyright © 2017 Elsevier B.V. All rights reserved.

Geochemistry of zircons from basic rocks of the Korosten anorthosite-mangerite-charnockite-granite complex, north-western region of the Ukrainian Shield

NASA Astrophysics Data System (ADS)

Shumlyanskyy, Leonid; Belousova, Elena; Petrenko, Oksana

2017-09-01

The concentrations of 26 trace elements have been determined by laser ablation ICP-MS in zircons from four samples of basic rocks of the Korosten anorthosite-mangerite-charnockite-granite plutonic complex, the Ukrainian Shield. Zircons from the Fedorivka and Torchyn gabbroic intrusions and Volynsky anorthosite massif have distinctive abundances of many trace elements (REE, Sr, Y, Mn, Th). Zircons from the gabbroic massifs are unusually enriched in trace elements, while zircons from pegmatites in anorthosite are relatively depleted in trace elements. High concentrations of trace elements in zircons from gabbroic intrusions can be explained by their crystallization from residual interstitial melts enriched in incompatible elements. The zircons studied demonstrate a wide range of Ti concentrations, which reflects their temperature of crystallization: the zircons most enriched in Ti, from mafic pegmatites of the Horbuliv quarry (20-40 ppm), have the highest temperature of crystallization (845 ± 40 °C). Lower (720-770 °C) temperatures of zircon crystallization in gabbroic rocks are explained by its crystallization from the latest portions of the interstitial melt or by simultaneous crystallization of ilmenite. The Ce anomaly in zircons correlates with the degree of oxidation of the coexisting ilmenite.

Multilayering of Calcium Aerosol-OT at the Mica/Water Interface Studied with Neutron Reflection: Formation of a Condensed Lamellar Phase at the CMC.

PubMed

Griffin, L R; Browning, K L; Lee, S Y; Skoda, M W A; Rogers, S; Clarke, S M

2016-12-13

Using specular neutron reflection, the adsorption of sodium and calcium salts of the surfactant bis(2-ethylhexyl) sulfosuccinate (Aerosol-OT or AOT) has been studied at the mica/water interface at concentrations between 0.1 and 2 CMC. The pH dependence of the adsorption was also probed. No evidence of the adsorption of Na(AOT) was found even at the critical micelle concentration (CMC) while the calcium salt was found to adsorb significantly at concentrations of 0.5 CMC and above. This interesting and somewhat unexpected finding demonstrates that counterion identity may be used to tune the adsorption of anionic surfactants on anionic surfaces. At the CMC, three condensed bilayers of Ca(AOT) 2 were adsorbed at pH 7 and 9 and four bilayers adsorbed at pH 4. Multilayering at the CMC of Ca(AOT) 2 on the mica surface is an unusual feature of this surfactant/surface combination. Only single bilayer adsorption has been observed at other surfaces at the CMC. We suggest this arises from the high charge density of mica which must provide an excellent template for the surfactant.

Large rock avalanches triggered by the M 7.9 Denali Fault, Alaska, earthquake of 3 November 2002

USGS Publications Warehouse

Jibson, R.W.; Harp, E.L.; Schulz, W.; Keefer, D.K.

2006-01-01

The moment magnitude (M) 7.9 Denali Fault, Alaska, earthquake of 3 November 2002 triggered thousands of landslides, primarily rock falls and rock slides, that ranged in volume from rock falls of a few cubic meters to rock avalanches having volumes as great as 20 ?? 106 m3. The pattern of landsliding was unusual: the number and concentration of triggered slides was much less than expected for an earthquake of this magnitude, and the landslides were concentrated in a narrow zone about 30-km wide that straddled the fault-rupture zone over its entire 300-km length. Despite the overall sparse landslide concentration, the earthquake triggered several large rock avalanches that clustered along the western third of the rupture zone where acceleration levels and ground-shaking frequencies are thought to have been the highest. Inferences about near-field strong-shaking characteristics drawn from interpretation of the landslide distribution are strikingly consistent with results of recent inversion modeling that indicate that high-frequency energy generation was greatest in the western part of the fault-rupture zone and decreased markedly to the east. ?? 2005 Elsevier B.V. All rights reserved.

Significant mobility enhancement in extremely thin highly doped ZnO films

DOE Office of Scientific and Technical Information (OSTI.GOV)

Look, David C., E-mail: david.look@wright.edu; Wyle Laboratories, Inc., 2601 Mission Point Blvd., Dayton, Ohio 45431; Air Force Research Laboratory Sensors Directorate, 2241 Avionics Circle, Wright-Patterson AFB, Ohio 45433

2015-04-13

Highly Ga-doped ZnO (GZO) films of thicknesses d = 5, 25, 50, and 300 nm, grown on 160-nm ZnO buffer layers by molecular beam epitaxy, had 294-K Hall-effect mobilities μ{sub H} of 64.1, 43.4, 37.0, and 34.2 cm{sup 2}/V-s, respectively. This extremely unusual ordering of μ{sub H} vs d is explained by the existence of a very high-mobility Debye tail in the ZnO, arising from the large Fermi-level mismatch between the GZO and the ZnO. Scattering theory in conjunction with Poisson analysis predicts a Debye-tail mobility of 206 cm{sup 2}/V-s at the interface (z = d), falling to 58 cm{sup 2}/V-s at z = d + 2 nm. Excellent fits to μ{sub H}more » vs d and sheet concentration n{sub s} vs d are obtained with no adjustable parameters.« less

Zero-order metoprolol pharmacokinetics after therapeutic doses: severe toxicity and cardiogenic shock.

PubMed

Isbister, Geoffrey K; Ang, Karyn; Gorman, Kieron; Cooper, Joyce; Mostafa, Ahmed; Roberts, Michael S

2016-11-01

Acute beta-blocker overdose can cause severe cardiac dysfunction. Chronic toxicity is rare but potentially severe. We report therapeutic dosing of metoprolol resulting in unusual pharmacokinetics and toxicity, given high-dose insulin therapy for treatment. A 90-year-old female presented with hypotension, tachycardia and severe cardiac dysfunction after commencing a rapidly increasing metoprolol dose of 250 mg split daily. She was admitted to intensive care and given high-dose insulin therapy (10 U/kg/h), noradrenaline, adrenaline and dobutamine for severe cardiac dysfunction (cardiac index, 0.76 L/min/m 2 ). She developed acute renal failure, ischaemic hepatitis and disseminated intravascular coagulopathy. Inotropes and high-dose insulin were weaned over four days with complete recovery. Metoprolol was quantified with liquid chromatography-tandem mass spectrometry and concentration-time data were analysed using MONOLIX ® vs 4.3 ( www.lixoft.com ). Admission metoprolol concentration was 2.39 μg/mL (therapeutic reference range: 0.035-0.5 μg/mL). Data best fitted a one compartmental model with Michaelis-Menten kinetics and zero order elimination at high concentrations. Final parameter estimates were V, 63.4 L, maximum rate [V m ], 9.57 mg h -1 , Michaelis constant [K m ], 1.97 mg L -1 . Predicted elimination half-life decreased from 20 h over time until there was first order elimination with a half-life 9 h. The time course of cardiac dysfunction was longer than acute overdose but consistent with prolonged zero order elimination of metoprolol, suggesting the patient was a poor CYP2D6 metaboliser. High-dose insulin euglycaemia appeared to be effective in combination with vasoconstrictors/inotropes.

Superconcentrated electrolytes for a high-voltage lithium-ion battery

PubMed Central

Wang, Jianhui; Yamada, Yuki; Sodeyama, Keitaro; Chiang, Ching Hua; Tateyama, Yoshitaka; Yamada, Atsuo

2016-01-01

Finding a viable electrolyte for next-generation 5 V-class lithium-ion batteries is of primary importance. A long-standing obstacle has been metal-ion dissolution at high voltages. The LiPF6 salt in conventional electrolytes is chemically unstable, which accelerates transition metal dissolution of the electrode material, yet beneficially suppresses oxidative dissolution of the aluminium current collector; replacing LiPF6 with more stable lithium salts may diminish transition metal dissolution but unfortunately encounters severe aluminium oxidation. Here we report an electrolyte design that can solve this dilemma. By mixing a stable lithium salt LiN(SO2F)2 with dimethyl carbonate solvent at extremely high concentrations, we obtain an unusual liquid showing a three-dimensional network of anions and solvent molecules that coordinate strongly to Li+ ions. This simple formulation of superconcentrated LiN(SO2F)2/dimethyl carbonate electrolyte inhibits the dissolution of both aluminium and transition metal at around 5 V, and realizes a high-voltage LiNi0.5Mn1.5O4/graphite battery that exhibits excellent cycling durability, high rate capability and enhanced safety. PMID:27354162

Unusually high rotational temperature of the CN radical

NASA Astrophysics Data System (ADS)

Krełowski, J.; Galazutdinov, G.; Beletsky, Y.

2011-07-01

We analyse a high-resolution, high signal-to-noise spectrogram of the hot reddened star Trumpler 16 112 to find relationships between the physical parameters of the intervening interstellar medium (e.g., the rotational temperature of the CN radical) and the intensities of interstellar lines/bands. We report on the discovery of an interstellar cloud that shows an exceptionally high rotational temperature of CN (4.5 K) and unusually strong Ca I and Fe I interstellar lines. This rare CaFe-type cloud seemingly contains no diffuse band carriers. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere, Chile. Programs 073.D-0609(A) and 082.C-0566(A).

The use of amino acid indices for assessing organic matter quality and microbial abundance in deep-sea Antarctic sediments of IODP Expedition 318

USGS Publications Warehouse

Carr, Stephanie A; Mills, Christopher T.; Mandernack, Kevin W

2016-01-01

The Adélie Basin, located offshore of the Wilkes Land margin, experiences unusually high sedimentation rates (~ 2 cm yr− 1) for the Antarctic coast. This study sought to compare depthwise changes in organic matter (OM) quantity and quality with changes in microbial biomass with depth at this high-deposition site and an offshore continental margin site. Sediments from both sites were collected during the International Ocean Drilling (IODP) Program Expedition 318. Viable microbial biomass was estimated from concentrations of bacterial-derived phospholipid fatty acids, while OM quality was assessed using four different amino acid degradation proxies. Concentrations of total hydrolysable amino acids (THAA) measured from the continental margin suggest an oligotrophic environment, with THAA concentrations representing only 2% of total organic carbon with relative proportions of non-protein amino acids β-alanine and γ-aminobutyric acid as high as 40%. In contrast, THAA concentrations from the near-shore Adélie Basin represent 40%–60% of total organic carbon. Concentrations of β-alanine and γ-aminobutyric acid were often below the detection limit and suggest that the OM of the basin as labile. DI values in surface sediments at the Adélie and margin sites were measured to be + 0.78 and − 0.76, reflecting labile and more recalcitrant OM, respectively. Greater DI values in deeper and more anoxic portions of both cores correlated positively with increased relative concentrations of phenylalanine plus tyrosine and may represent a change of redox conditions, rather than OM quality. This suggests that DI values calculated along chemical profiles should be interpreted with caution. THAA concentrations, the percentage of organic carbon (CAA%) and total nitrogen (NAA%) represented by amino acids at both sites demonstrated a significant positive correlation with bacterial abundance estimates. These data suggest that the selective degradation of amino acids, as indicated by THAA concentrations, CAA% or NAA% values may be a better proxy for describing the general changes in sedimentary bacterial abundances than total organic matter or bulk sedimentation rates.

Popping rocks from the Mid-Atlantic Ridge: Insights into mantle volatile concentrations and degassing dynamics

NASA Astrophysics Data System (ADS)

Jones, M.; Soule, S. A.; Kurz, M. D.; Wanless, V. D.; Le Roux, V.; Klein, F.; Mittelstaedt, E. L.; Curtice, J.

2016-12-01

During a 1985 cruise, the Mid-Atlantic Ridge (MAR) near 14°N yielded an unusually vesicular mid-ocean ridge (MOR) basalt that popped upon recovery from the seafloor due to the release of trapped volatiles. This `popping rock' has been inferred to be representative of primitive, undegassed magmas from the upper mantle due to its high volatile concentrations. Thus, the sample has been used to constrain CO2 flux from the MOR system, upper mantle volatile concentrations, and magma degassing dynamics. However, the lack of geologic context for the original popping rock raises questions about whether it truly reflects the volatile content of its mantle source. Here, we present results from a 2016 cruise to the MAR aimed at characterizing the geologic context of popping rocks and understanding their origins. The newly recovered samples display differences in volatile concentrations and vesicularities between popping and non-popping rocks. These differences may be related to geologic setting and eruption dynamics with potential implications for mantle volatile concentrations. Volatile concentrations in the outer quenched margin of new samples were measured by ion microprobe to elucidate degassing systematics, brine/magma interactions, and popping rock formation. The large variability in dissolved H2O (0.05-0.77 wt%) can be attributed to spatially variable brine contamination. Dissolved CO2 concentrations (153-356 ppm) are likely controlled by initial volatile concentrations and variable degrees of degassing. The subset of popping samples display low dissolved CO2 concentrations (161-178 ppm) and moderate dissolved H2O concentrations (.44-.50 wt%) and are at equilibrium with their eruption depth based on solubility calculations. X-ray microtomography reveals vesicularity in newly collected popping rocks exceeding 19%, making these samples the most highly vesicular recovered from the MAR. The total gas contents in the basaltic glasses are inferred from dissolved volatile concentrations and vesicularity. These calculations are aided by analysis of gas contents in vesicles by confocal Raman spectroscopy and vacuum crushing experiments. The preliminary results and seafloor observations allow an evaluation of the origins of popping rocks and their implications for mantle volatile concentrations.

Isoprene and its degradation products as strong ozone precursors in Insubria, Northern Italy

NASA Astrophysics Data System (ADS)

Duane, M.; Poma, B.; Rembges, D.; Astorga, C.; Larsen, B. R.

Frequent smog episodes occur during spring, summer, and autumn in Insubria, Northern Italy. On a test site in this area the atmospheric concentration of the photo-oxidants ozone and peroxyacetyl nitrate has been monitored over a year (2000) together with ozone precursors listed in the European Union Air Quality Directive 2002/3/EC, such as nitrous oxides (NO X) and volatile organic compounds (VOC) including hydrocarbons and carbonyls. The results of this study revealed a strong impact of biogenic isoprene on the air quality. In winter isoprene was detected at the ppt level and correlated with anthropogenic VOC. However, during the growing season isoprene exhibited a distinct diurnal variation with maximum concentrations late in the afternoon reaching up 70 ppbC attributed to strong emissions from the abundant vegetation of broad-leaf deciduous trees in this area. A new HPLC-MS method was developed for the determination of isoprene's primary atmospheric oxidation products methacrolein as its 2,4-dinitrophenylhydrazone and methyl vinyl ketone as an unusual double derivative with 2,4-dinitrophenylhydrazine. Methacrolein and methyl vinyl ketone followed the same diurnal and annual trends as isoprene. The average monthly concentration of isoprene and these products ranged from around 10 ppbC in June, July and September to 20 ppbC in August, which constitutes 15-30% of C 3-C 9 VOCs. The contribution from isoprene photo-oxidation to the ambient air formaldehyde concentrations was also found to be high during this period ranging from 30% to 60% in May, June, July and August. From the atmospheric VOC and NO X concentrations the local photochemical ozone formation was estimated by the incremental reactivity approach. The calculations showed that in summer isoprene's contribution to the local ozone formation was as high as 50-75%.

Purification and characterization of creatine kinase isozymes from the nurse shark Ginglymostoma cirratum.

PubMed

Gray, K A; Grossman, S H; Summers, D D

1986-01-01

Creatine kinase from nurse shark brain and muscle has been purified to apparent homogeneity. In contrast to creatine kinases from most other vertebrate species, the muscle isozyme and the brain isozyme from nurse shark migrate closely in electrophoresis and, unusually, the muscle isozyme is anodal to the brain isozyme. The isoelectric points are 5.3 and 6.2 for the muscle and brain isozymes, respectively. The purified brain preparation also contains a second active protein with pI 6.0. The amino acid content of the muscle isozyme is compared with other isozymes of creatine kinase using the Metzger Difference Index as an estimation of compositional relatedness. All comparisons show a high degree of compositional similarity including arginine kinase from lobster muscle. The muscle isozyme is marginally more resistant to temperature inactivation than the brain isozyme; the muscle protein does not exhibit unusual stability towards high concentrations of urea. Kinetic analysis of the muscle isozyme reveals Michaelis constants of 1.6 mM MgATP, 12 mM creatine, 1.2 mM MgADP and 50 mM creatine phosphate. Dissociation constants for the same substrate from the binary and ternary enzyme-substrate complex do not differ significantly, indicating limited cooperatively in substrate binding. Enzyme activity is inhibited by small planar anions, most severely by nitrate. Shark muscle creatine kinase hybridizes in vitro with rabbit muscle or monkey brain creatine kinase; shark brain isozyme hybridizes with monkey brain or rabbit brain creatine kinase. Shark muscle and shark brain isozymes, under a wide range of conditions, failed to produce a detectable hybrid.

Hurricane Agnes rainfall and floods, June-July 1972

USGS Publications Warehouse

Bailey, James F.; Patterson, James Lee; Paulhus, Joseph Louis Hornore

1975-01-01

Hurricane Agnes originated in the Caribbean Sea region in mid-June. Circulation barely reached hurricane intensity for a brief period in the Gulf of Mexico. The storm crossed the Florida Panhandle coastline on June 19, 1972, and followed an unusually extended overland trajectory combining with an extratropical system to bring very heavy rain from the Carolinas northward to New York. This torrential rain followed the abnormally wet May weather in the Middle Atlantic States and set the stage for the subsequent major flooding. The record-breaking floods occurred in the Middle Atlantic States in late June and early July 1972. Many streams in the affected area experienced peak discharges several times the previous maxima of record. Estimated recurrence intervals of peak flows at many gaging stations on major rivers and their tributaries exceeded 100 years. The suspended-sediment concentration and load of most flooded streams were also unusually high. The widespread flooding from this storm caused Agnes to be called the most destructive hurricane in United States history, claiming 117 lives and causing damage estimated at $3.1 billion in 12 States. Damage was particularly high in New York, Pennsylvania, Maryland, and Virginia. The detailed life history of Hurricane Agnes, including the tropical depression and tropical storm stages, is traced. Associated rainfalls are analyzed and compared with climatologic recurrence values. These are followed by a detailed description of the flood and streamflows of each affected basin. A summary of peak stages and discharges and comparison data for previous floods at 989 stations are presented. Deaths and flood damage estimates are compiled.

Histamine poisoning (scombroid fish poisoning): an allergy-like intoxication.

PubMed

Taylor, S L; Stratton, J E; Nordlee, J A

1989-01-01

Histamine poisoning results from the consumption of foods, typically certain types of fish and cheeses, that contain unusually high levels of histamine. Spoiled fish of the families, Scombridae and Scomberesocidae (e.g. tuna, mackerel, bonito), are commonly implicated in incidents of histamine poisoning, which leads to the common usage of the term, "scombroid fish poisoning", to describe this illness. However, certain non-scombroid fish, most notably mahi-mahi, bluefish, and sardines, when spoiled are also commonly implicated in histamine poisoning. Also, on rare occasions, cheeses especially Swiss cheese, can be implicated in histamine poisoning. The symptoms of histamine poisoning generally resemble the symptoms encountered with IgE-mediated food allergies. The symptoms include nausea, vomiting, diarrhea, an oral burning sensation or peppery taste, hives, itching, red rash, and hypotension. The onset of the symptoms usually occurs within a few minutes after ingestion of the implicated food, and the duration of symptoms ranges from a few hours to 24 h. Antihistamines can be used effectively to treat this intoxication. Histamine is formed in foods by certain bacteria that are able to decarboxylate the amino acid, histidine. However, foods containing unusually high levels of histamine may not appear to be outwardly spoiled. Foods with histamine concentrations exceeding 50 mg per 100 g of food are generally considered to be hazardous. Histamine formation in fish can be prevented by proper handling and refrigerated storage while the control of histamine formation in cheese seems dependent on insuring that histamine-producing bacteria are not present in significant numbers in the raw milk.

Complex layering of the Orange Mountain Basalt: New Jersey, USA

NASA Astrophysics Data System (ADS)

Puffer, John H.; Block, Karin A.; Steiner, Jeffrey C.; Laskowich, Chris

2018-06-01

The Orange Mountain Basalt of New Jersey is a Mesozoic formation consisting of three units: a single lower inflated sheet lobe about 70 m thick (OMB1), a middle pillow basalt about 10 to 20 m thick (OMB2), and an upper compound pahoehoe flow about 20 to 40 m thick (OMB3). The Orange Mountain Basalt is part of the Central Atlantic Magmatic Province. Quarry and road-cut exposures of OMB1 near Paterson, New Jersey, display some unusual layering that is the focus of this study. OMB1 exposures displays the typical upper crust, core, and basal crust layers of sheet lobes but throughout the Patterson area also display distinct light gray layers of microvesicular basalt mineralized with albite directly over the basal crust and under the upper crust. The lower microvesicular layer is associated with mega-vesicular diapirs. We propose that the upper and lower microvesicular layers were composed of viscous crust that was suddenly quenched before it could devolatilize immediately before the solidification of the core. During initial cooling, the bottom of the basal layer was mineralized with high concentrations of calcite and albite during a high-temperature hydrothermal event. Subsequent albitization, as well as zeolite, prehnite, and calcite precipitation events, occurred during burial and circulation of basin brine heated by recurring Palisades magmatism below the Orange Mountain Basalt. Some of the events experienced by the Orange Mountain Basalt are unusual and place constraints on the fluid dynamics of thick flood basalt flows in general. The late penetration of vesicular diapirs through the entire thickness of the flow interior constrains its viscosity and solidification history.

[Fatty acid of Rkatsiteli grape seed oil, Phellodendron lavallei oil and Amaranthus seeds oil and its comparative byological activity].

PubMed

Kikalishvili, B Iu; Zurabashvili, D Z; Zurabashvili, Z A; Turabelidze, D G; Shanidze, L A

2012-11-01

The aim of the study is individual qualitively and quantitatively identification of fatty acids in Pkatsiteli grape seed oil, Phellodendron lavallei oil and Amaranthus seed oil and prediction of its biological activity. Using high-effective liquid chromatogramphy fatty acids were franctionated. Their relative concentrations are expressed as percentages of the total fatty acid component. Identification of the fatty acids consituents is based on comparison of their retention time with that of known standards. The predominant fatty acids in the oils were palmitic, oleic and stearic acids. The investigation demonstrated that fatty acids composition takes marked part in lipid metabolism of biological necessary components. The most interesting result of the investigation was the detection of unusual for the essentain oil begenic acid.

Faces of a changing climate: semi-quantitative multi-mycotoxin analysis of grain grown in exceptional climatic conditions in Norway.

PubMed

Uhlig, Silvio; Eriksen, Gunnar Sundstøl; Hofgaard, Ingerd Skow; Krska, Rudolf; Beltrán, Eduardo; Sulyok, Michael

2013-09-27

Recent climatological research predicts a significantly wetter climate in Southern Norway as a result of global warming. Thus, the country has already experienced unusually wet summer seasons in the last three years (2010-2012). The aim of this pilot study was to apply an existing multi-analyte LC-MS/MS method for the semi-quantitative determination of 320 fungal and bacterial metabolites in Norwegian cereal grain samples from the 2011 growing season. Such knowledge could provide important information for future survey and research programmes in Norway. The method includes all regulated and well-known mycotoxins such as aflatoxins, trichothecenes, ochratoxin A, fumonisins and zearalenone. In addition, a wide range of less studied compounds are included in the method, e.g., Alternaria toxins, ergot alkaloids and other metabolites produced by fungal species within Fusarium, Penicillium and Aspergillus. Altogether, 46 metabolites, all of fungal origin, were detected in the 76 barley, oats and wheat samples. The analyses confirmed the high prevalence and relatively high concentrations of type-A and -B trichothecenes (e.g., deoxynivalenol up to 7230 µg/kg, HT-2 toxin up to 333 µg/kg). Zearalenone was also among the major mycotoxins detected (maximum concentration 1670 µg/kg). Notably, several other Fusarium metabolites such as culmorin, 2-amino-14,16-dimethyloctadecan-3-ol and avenacein Y were co-occurring. Furthermore, the most prevalent Alternaria toxin was alternariol with a maximum concentration of 449 µg/kg. A number of Penicillium and Aspergillus metabolites were also detected in the samples, e.g., sterigmatocystin in concentrations up to 20 µg/kg.

First Report of a Toxic Nodularia spumigena (Nostocales/ Cyanobacteria) Bloom in Sub-Tropical Australia. II. Bioaccumulation of Nodularin in Isolated Populations of Mullet (Mugilidae)

PubMed Central

Stewart, Ian; Eaglesham, Geoffrey K.; McGregor, Glenn B.; Chong, Roger; Seawright, Alan A.; Wickramasinghe, Wasantha A.; Sadler, Ross; Hunt, Lindsay; Graham, Glenn

2012-01-01

Fish collected after a mass mortality at an artificial lake in south-east Queensland, Australia, were examined for the presence of nodularin as the lake had earlier been affected by a Nodularia bloom. Methanol extracts of muscle, liver, peritoneal and stomach contents were analysed by HPLC and tandem mass spectrometry; histological examination was conducted on livers from captured mullet. Livers of sea mullet (Mugil cephalus) involved in the fish kill contained high concentrations of nodularin (median 43.6 mg/kg, range 40.8–47.8 mg/kg dry weight; n = 3) and the toxin was also present in muscle tissue (median 44.0 μg/kg, range 32.3–56.8 μg/kg dry weight). Livers of fish occupying higher trophic levels accumulated much lower concentrations. Mullet captured from the lake 10 months later were also found to have high hepatic nodularin levels. DNA sequencing of mullet specimens revealed two species inhabiting the study lake: M. cephalus and an unidentified mugilid. The two mullet species appear to differ in their exposure and/or uptake of nodularin, with M. cephalus demonstrating higher tissue concentrations. The feeding ecology of mullet would appear to explain the unusual capacity of these fish to concentrate nodularin in their livers; these findings may have public health implications for mullet fisheries and aquaculture production where toxic cyanobacteria blooms affect source waters. This report incorporates a systematic review of the literature on nodularin measured in edible fish, shellfish and crustaceans. PMID:22851952

First report of a toxic Nodularia spumigena (Nostocales/ Cyanobacteria) bloom in sub-tropical Australia. II. Bioaccumulation of nodularin in isolated populations of mullet (Mugilidae).

PubMed

Stewart, Ian; Eaglesham, Geoffrey K; McGregor, Glenn B; Chong, Roger; Seawright, Alan A; Wickramasinghe, Wasantha A; Sadler, Ross; Hunt, Lindsay; Graham, Glenn

2012-07-01

Fish collected after a mass mortality at an artificial lake in south-east Queensland, Australia, were examined for the presence of nodularin as the lake had earlier been affected by a Nodularia bloom. Methanol extracts of muscle, liver, peritoneal and stomach contents were analysed by HPLC and tandem mass spectrometry; histological examination was conducted on livers from captured mullet. Livers of sea mullet (Mugil cephalus) involved in the fish kill contained high concentrations of nodularin (median 43.6 mg/kg, range 40.8-47.8 mg/kg dry weight; n = 3) and the toxin was also present in muscle tissue (median 44.0 μg/kg, range 32.3-56.8 μg/kg dry weight). Livers of fish occupying higher trophic levels accumulated much lower concentrations. Mullet captured from the lake 10 months later were also found to have high hepatic nodularin levels. DNA sequencing of mullet specimens revealed two species inhabiting the study lake: M. cephalus and an unidentified mugilid. The two mullet species appear to differ in their exposure and/or uptake of nodularin, with M. cephalus demonstrating higher tissue concentrations. The feeding ecology of mullet would appear to explain the unusual capacity of these fish to concentrate nodularin in their livers; these findings may have public health implications for mullet fisheries and aquaculture production where toxic cyanobacteria blooms affect source waters. This report incorporates a systematic review of the literature on nodularin measured in edible fish, shellfish and crustaceans.

The performance and capabilities of terrestrial organisms in extreme and unusual gaseous and liquid environments. Performance of fungi in exotic and harsh environments

NASA Technical Reports Server (NTRS)

Siegel, S. M.

1975-01-01

The growth of Penicillium in saline and low temperature conditions during a 15 month incubation period was studied. Data are also given on the potential 1f fungu for modification of the surface geochemistry of the earth and the capacity of these fungi to solubilize and concentrate metals.

Hemophilia Care in the Pediatric Age

PubMed Central

Bertamino, Marta; Riccardi, Francesca; Banov, Laura; Svahn, Johanna; Molinari, Angelo Claudio

2017-01-01

Hemophilia is the most common of the severe bleeding disorders and if not properly managed since early infancy can lead to chronic disease and lifelong disabilities. However, it enjoys the most efficacious and safe treatment among the most prevalent monogenic disorders. Hemophilia should be considered in the neonatal period in the case of unusual bleeding or in the case of positive family history. Later, hemophilia should be suspected mainly in males because of abnormal bruising/bleeding or unusual bleeding following invasive procedures—for example, tonsillectomy or circumcision. Prophylactic treatment that is started early with clotting-factor concentrates has been shown to prevent hemophilic arthropathy and is, therefore, the gold standard of care for hemophilia A and B in most countries with adequate resources. Central venous access catheters and arterovenous fistulas play an important role in the management of hemophilia children requiring repeated and/or urgent administration of coagulation factor concentrates. During childhood and adolescence, personalized treatment strategies that suit the patient and his lifestyle are essential to ensure optimal outcomes. Physical activity is important and can contribute to better coordination, endurance, flexibility and strength. The present article focuses also on questions frequently posed to pediatric hematologists like vaccinations, day-care/school access and dental care. PMID:28534860

General solutions for the oxidation kinetics of polymers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gillen, K.T.; Clough, R.L.; Wise, J.

1996-08-01

The simplest general kinetic schemes applicable to the oxidation of polymers are presented, discussed and analyzed in terms of the underlying kinetic assumptions. For the classic basic autoxidation scheme (BAS), which involves three bimolecular termination steps and is applicable mainly to unstabilized polymers, typical assumptions used singly or in groups include (1) long kinetic chain length, (2) a specific ratio of the termination rate constants and (3) insensitivity to the oxygen concentration (e.g., domination by a single termination step). Steady-state solutions for the rate of oxidation are given in terms of one, two, three, or four parameters, corresponding respectively tomore » three, two, one, or zero kinetic assumptions. The recently derived four-parameter solution predicts conditions yielding unusual dependencies of the oxidation rate on oxygen concentration and on initiation rate, as well as conditions leading to some unusual diffusion-limited oxidation profile shapes. For stabilized polymers, unimolecular termination schemes are typically more appropriate than bimolecular. Kinetics incorporating unimolecular termination reactions are shown to result in very simple oxidation expressions which have been experimentally verified for both radiation-initiated oxidation of an EPDM and thermoxidative degradation of nitrile and chloroprene elastomers.« less

UNUSUAL BACTEROIDES-LIKE ORGANISM

PubMed Central

Goldberg, Herbert S.; Barnes, Ella M.; Charles, Anthony B.

1964-01-01

Goldberg, Herbert S. (University of Missouri, Columbia), Ella M. Barnes, and Anthony B. Charles. Unusual Bacteroides-like organism. J. Bacteriol. 87:737–742. 1964.—An organism is described which appears to be a new species of gram-negative, anaerobic, nonsporulating rod. It was isolated from poultry caeca at levels of 107 to 108 per g. It is primarily distinguished from related organisms by its unusual size (2.0 by 10.0 μ). It is biochemically differentiated from known species of Bacteroides, Fusobacterium, Sphaerophorous, and other accepted related genera. Its presence in large numbers in the gut of poultry, and its high metabolic activity would seem to indicate an important intestinal organism. Images PMID:14127590

An unusual case of posttrabeculectomy conjunctival granuloma.

PubMed

Choudhary, Samiksha; Sen, Swarnali; Gupta, Omprakash

2018-01-01

We report an unusual case of granulomatous inflammation that presented adjacent to bleb 3 weeks postoperatively after combined phacoemulsification and trabeculectomy surgery with mitomycin-C due to retained microfragments of methyl cellulose sponge. The commonly used antimetabolite delivery devices are made of cellulose. Methyl cellulose sponges are friable, and they are likely to leave behind microfragments in subconjunctival space. In our case, bleb integrity was maintained, unlike the earlier reported cases which presented with bleb leak. Hence, one should have high index of suspicion in unusual cases of postoperative inflammation not resolving conservatively. Although rare, retained sponge particles can be a cause of early bleb-related inflammation which can lead to bleb failure.

An unusual case of posttrabeculectomy conjunctival granuloma

PubMed Central

Choudhary, Samiksha; Sen, Swarnali; Gupta, Omprakash

2018-01-01

We report an unusual case of granulomatous inflammation that presented adjacent to bleb 3 weeks postoperatively after combined phacoemulsification and trabeculectomy surgery with mitomycin-C due to retained microfragments of methyl cellulose sponge. The commonly used antimetabolite delivery devices are made of cellulose. Methyl cellulose sponges are friable, and they are likely to leave behind microfragments in subconjunctival space. In our case, bleb integrity was maintained, unlike the earlier reported cases which presented with bleb leak. Hence, one should have high index of suspicion in unusual cases of postoperative inflammation not resolving conservatively. Although rare, retained sponge particles can be a cause of early bleb-related inflammation which can lead to bleb failure. PMID:29563697

Large PAMAM Dendron Induces Formation of Unusual P4332 Mesophase in Monoolein/Water system.

PubMed

Kumar, Manoj; Patil, Naganath G; Ambade, Ashootosh V; Kumaraswamy, Guruswamy

2018-05-18

Compact macromolecular dendrons have been shown to induce the formation of discontinuous inverse micellar assemblies with Fd3m symmetry in monoolein/water systems. Here, we demonstrate that a large PAMAM dendron (G5: fifth generation) induces the formation a very unusual mesophase with P4332 symmetry. This mesophase had previously been observed in monoolein/water systems only on addition of cytochrome C. The P4332 mesophase can be considered an intermediate phase between the bicontinuous Ia3d and discontinuous micellar mesophases. In this unusual phase, every third rod junction of the Ia3d mesophase is replaced with a spherical micelle. We present a detailed investigation of the phase behaviour of monoolein/water as a function of G5 concentration and temperature. Addition of 1% G5 in 85/15 monoolein/water system induces a transition from the L to Ia3d phase. Further increase in G5 concentration to above 2% induces the formation of the P4332 phase. Thus, incorporation of G5 yields a qualitatively different phase diagram when compared with incorporation of lower generation PAMAM dendrons (G2 - G4) in monoolein/water, where the reverse micellar Fd3m phase forms. PAMAM dendrons of all generations, G2 - G5, bear terminal amine groups that interact with the monoolein head group. The compact molecular architecture of the dendrons and these attractive interactions induce bending of the monoolein bilayer structure. For smaller dendrons, G2 - G4, this results in the formation of the Fd3m phase. However, the large size of the G5 dendron precludes this and a rare intermediate phase between the Ia3d and discontinuous micellar phase, the P4332 mesophase forms instead.

High concentrations of fluoride and boron in drinking water wells in the Muenster region--results of a preliminary investigation.

PubMed

Queste, A; Lacombe, M; Hellmeier, W; Hillermann, F; Bortulussi, B; Kaup, M; Ott, K; Mathys, W

2001-03-01

In 1998, two cases of severe dental fluorosis in schoolchildren occurred in the Muenster region. These cases took place in one household, where fluoridated toothpaste, fluoridated salt, and fluoride tablets were consumed. Furthermore, the family used drinking water from its private well only. Analyses of the well water ordered by local health officials revealed very high amounts of fluoride, boron, and other electrolytes. This unusual combination of high amounts of fluoride and boron could also be found in the water of a great number of other private wells that are the only source for drinking water in this rural region of the Muensterland. Anthropogenic sources could be excluded. Because of this, the results of the water samples were collated to the specific geological situation in this area. In the Muenster region there are marl layers of the chalk era covered with quarternary sediments. The quarternary sediments are up to 10 to 20 metres thick and they usually conduct the groundwater. The marl contains high concentrations of fluoride and boron. In some places the groundwater has contact with these layers. To check the amount of fluoride and boron in the groundwater, indicator values were sought, which can give a hint of high contents of these trace elements. In this study the conductivity and acidity were identified as possible indicators of a high amount of fluoride and boron in the drinking water in this specific region. To work economically and efficiently, the drinking water should be checked for fluoride and boron on a regular basis only when these values are extraordinarily high. In the case of high concentrations, especially of fluoride, in the drinking water the persons concerned should be informed about their potential health risk, giving them the opportunity to optimise the total daily intake of fluoride.

From coffee ring to spherulites ring of poly(ethylene oxide) film from drying droplet

NASA Astrophysics Data System (ADS)

Hu, Yinchun; Zhang, Xuerong; Qiu, Maibo; Wei, Yan; Zhou, Qiong; Huang, Di

2018-03-01

We discuss how the "spherulites ring" morphology and "coffee ring" profile of PEO film formed by the drying droplet at glass substrate with different heating rate. Upon increasing the heating rate of substrate, it is found that deposited PEO film from drying droplet shows the unusually observed "coffee ring" profile and "spherulites ring" morphology. The main mechanism for this phenomenon is proposed to be an enhanced Marangoni convection which is induced by the increased solute concentration gradient and reduced viscous force above 70 °C. A simple formation mechanism of the unusually observed "coffee ring" profile and "spherulites ring" morphology is proposed. These findings can be exploited to trace the center of Marangoni convection, with potential applications in designing the spherulite patterns of crystalline polymer films in ink-jet printing and self-assembly fields.

[Activity of butenafine against ocular pathogenic filamentous fungi in vitro].

PubMed

Xu, Yan; Pang, Guang-ren; Zhao, Dong-qing; Gao, Chuan-wen; Zhou, Lu-tan; Sun, Sheng-tao; Wang, Bing-liang; Chen, Zu-ji

2010-01-01

To investigate antifungal activity of butenafine in comparison with that of natamycin, amphotericin B and fluconazole against ocular pathogenic filamentous fungi in vitro. It was an experimental study. Susceptibility tests were performed against 260 isolates of ocular pathogenic filamentous fungi by broth dilution antifungal susceptibility test of filamentous fungi approved by the Clinical and Laboratory Standards Institute (CLSI) M38-A document. The isolates included Fusarium spp. (136), Aspergillus spp. (98), Alternaria alternata (9), Curvularia lunata (3), and unusual ocular pathogens (14). Final concentration ranged from 0.008 to 16.000 mg/L for butenafine, from 0.031 to 16.000 mg/L for amphotericin B and natamycin, and from 0.5 to 256.0 mg/L for fluconazole. Following incubation at 35 degrees C for 48 h, minimal inhibitory concentration (MIC) was determined according to the CLSI M38-A document. For amphotericin B and natamycin, the MIC was defined as the lowest drug concentration that prevented any discernible growth. For butenafine and fluconazole, the MIC was defined as the lowest concentration in which an approximately 75% reduction compared to the growth of the control was observed. Candida parapsilosis ATCC22019 was used as quality control strains to validated the results. Mean MIC and MIC range, the MIC at which 50% of the isolates tested were inhibited (MIC(50)) and the MIC at which 90% of the isolates tested were inhibited (MIC(90)), were provided for all the isolates tested by using descriptive statistical analysis with the statistical SPSS package (version 13.0). MIC(90) of butenafine, natamycin, amphotericin B and fluconazole were 4, 8, 2 and 512 mg/L for Fusarium spp., respectively; 0.063, 32.000, 2.000 and 256.000 mg/L for Aspergillus spp., respectively; 0.5, 8.0, 2.0 and 128.0 mg/L for Alternaria alternate, respectively; 0.125, 2.000, 0.500 and 4.000 mg/L for Curvularia lunata, respectively; and 1, 4, 1 and 256 mg/L for unusual ocular pathogens, respectively. Butenafine exhibits potent antifungal activity against a wide variety of ocular pathogenic fungi, especially for Aspergillus spp., Alternaria alternata, Curvularia lunata, and some unusual ocular pathogens and may have a role in future studies of antifungal eye drops and treating fungal keratitis.

Intramuscular Dirofilariasis Mimicking an Orbital Metastasis in a Patient with Breast Cancer

PubMed Central

Henderson, Brett M.; Hunt, Christopher H.; Eckel, Laurence J.; Schwartz, Kara M.; Diehn, Felix E.; Pritt, Bobbi S.; Schembri Wismayer, David J.; Garrity, James A.

2012-01-01

We present the unusual case of a 74 year-old female with a history of breast cancer who presented with acute painless orbital swelling and vertical diplopia. MRI revealed a focal enhancing mass within the superior rectus muscle. As the concern for metastatic disease was high, surgical biopsy was performed and revealed an unusual mimicker of metastatic disease, the parasitic infection dirofilariasis. PMID:23008795

Increased Prevalence of Unusual Sensory Behaviors in Infants at Risk For, and Teens With, Autism Spectrum Disorder

ERIC Educational Resources Information Center

Van Etten, Hannah M.; Kaur, Maninderjit; Srinivasan, Sudha M.; Cohen, Shereen J.; Bhat, Anjana; Dobkins, Karen R.

2017-01-01

The current study investigated the prevalence and pattern of unusual sensory behaviors (USBs) in teens with Autism Spectrum Disorder (ASD) and infants (3-36 months) at risk for ASD. From two different sites (UCSD and UConn), caregivers of infants at high (n = 32) and low risk (n = 33) for ASD, and teenagers with (n = 12) and without ASD (n = 11),…

A fluorophosphate-based inverse Keggin structure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fielden, John; Quasdorf, Kyle; Cronin, Leroy

An unusual PFO(3)(2-)-templated "inverse Keggin" polyanion, [Mo(12)O(46)(PF)(4)](4-), has been isolated from the degradation reaction of an {Mo(132)}-type Keplerate to [PMo(12)O(40)](3-) by [Cu(MeCN)(4)](PF(6)) in acetonitrile. (31)P-NMR studies suggest a structure-directing role for [Cu(MeCN)(4)](+) in the formation of the highly unusual all-inorganic inverse Keggin structure.

A fluorophosphate-based inverse Keggin structure.

PubMed

Fielden, John; Quasdorf, Kyle; Cronin, Leroy; Kögerler, Paul

2012-09-07

An unusual PFO(3)(2-)-templated "inverse Keggin" polyanion, [Mo(12)O(46)(PF)(4)](4-), has been isolated from the degradation reaction of an {Mo(132)}-type Keplerate to [PMo(12)O(40)](3-) by [Cu(MeCN)(4)](PF(6)) in acetonitrile. (31)P-NMR studies suggest a structure-directing role for [Cu(MeCN)(4)](+) in the formation of the highly unusual all-inorganic inverse Keggin structure.

Transient 5-oxoprolinuria: unusually high anion gap acidosis in an infant.

PubMed

Hulley, Sarah L; Perring, Jeff; Manning, Nigel; Olpin, Simon; Yap, Sufin

2015-12-01

Transient 5-oxoprolinuria is a phenomenon that is well recognised in adults. We illustrate an unusual paediatric case of transient 5-oxoprolinuria presenting during an episode of severe sepsis with concomitant paracetamol use. The 15-month-old patient had an extremely high anion gap metabolic acidosis. Adequate resuscitation failed to correct the biochemical disturbance, and high levels of 5-oxoproline were identified. A combination of haemofiltration, replenishment of glutathione stores with N-acetylcysteine and cessation of paracetamol administration resulted in the resolution of the acidosis. Subsequent testing following treatment of the sepsis revealed no ongoing 5-oxoprolinuria. Transient 5-oxoprolinuria has been previously reported in the adult population during episodes of severe sepsis and various pharmaceutical interventions. This case illustrates that it is a phenomenon that should be considered in paediatric patients where a very high anion gap metabolic acidosis exists that cannot be explained by the biochemical indices. • 5-oxoprolinuria in the paediatric population is usually secondary to an inborn error of metabolism. • Transient 5-oxoprolinuria is well recognised in adults during episodes of severe glutathione depletion. • Transient 5-oxoprolinuria is a phenomenon rarely reported in the paediatric population. • It highlights the importance of investigating a high anion gap such that unusual diagnoses are not missed.

A non-human primate model of human radiation-induced venocclusive liver disease and hepatocyte injury

PubMed Central

Yamamoto, Toshiyuki; Ito, Ryotaro; Brooks, Jenna M.; Guzman-Lepe, Jorge; Galambos, Csaba; Fong, Jason V.; Deutsch, Melvin; Quader, Mubina A.; Yamanouchi, Kosho; Kabarriti, Rafi; Mehta, Keyur; Soto-Gutierrez, Alejandro; Roy-Chowdhury, Jayanta; Locker, Joseph; Abe, Michio; Enke, Charles A.; Baranowska-Kortylewicz, Janina; Solberg, Timothy D.; Guha, Chandan; Fox, Ira J.

2014-01-01

Background Human liver has an unusual sensitivity to radiation that limits its use in cancer therapy or in preconditioning for hepatocyte transplantation. Since the characteristic venocclusive lesions of radiation-induced liver disease do not occur in rodents, there has been no experimental model to investigate the limits of safe radiation therapy or explore the pathogenesis of hepatic venocclusive disease. Methods We performed a dose escalation study in a primate, the cynomolgus monkey, using hypofractionated stereotactic body radiotherapy in 13 animals. Results At doses ≥40Gy, animals developed a systemic syndrome resembling human radiation-induced liver disease, consisting of decreased albumin, elevated alkaline phosphatase, loss of appetite, ascites, and normal bilirubin. Higher radiation doses were lethal, causing severe disease that required euthanasia approximately 10 weeks after radiation. Even at lower doses where radiation-induced liver disease was mild or non-existent, latent and significant injury to hepatocytes was demonstrated by asialoglycoprotein-mediated functional imaging. These monkeys developed hepatic failure with encephalopathy when they received parenteral nutrition containing high concentrations of glucose. Histologically, livers showed central obstruction via an unusual intimal swelling that progressed to central fibrosis. Conclusions The cynomolgus monkey, as the first animal model of human venocclusive radiation-induced liver disease, provides a resource for characterizing the early changes and pathogenesis of venocclusion, for establishing nonlethal therapeutic dosages, and for examining experimental therapies to minimize radiation injury. PMID:24315566

Biosynthesis of ilamycins featuring unusual building blocks and engineered production of enhanced anti-tuberculosis agents.

PubMed

Ma, Junying; Huang, Hongbo; Xie, Yunchang; Liu, Zhiyong; Zhao, Jin; Zhang, Chunyan; Jia, Yanxi; Zhang, Yun; Zhang, Hua; Zhang, Tianyu; Ju, Jianhua

2017-08-30

Tuberculosis remains one of the world's deadliest communicable diseases, novel anti-tuberculosis agents are urgently needed due to severe drug resistance and the co-epidemic of tuberculosis/human immunodeficiency virus. Here, we show the isolation of six anti-mycobacterial ilamycin congeners (1-6) bearing rare L-3-nitro-tyrosine and L-2-amino-4-hexenoic acid structural units from the deep sea-derived Streptomyces atratus SCSIO ZH16. The biosynthesis of the rare L-3-nitrotyrosine and L-2-amino-4-hexenoic acid units as well as three pre-tailoring and two post-tailoring steps are probed in the ilamycin biosynthetic machinery through a series of gene inactivation, precursor chemical complementation, isotope-labeled precursor feeding experiments, as well as structural elucidation of three intermediates (6-8) from the respective mutants. Most impressively, ilamycins E 1 /E 2 , which are produced in high titers by a genetically engineered mutant strain, show very potent anti-tuberculosis activity with an minimum inhibitory concentration value ≈9.8 nM to Mycobacterium tuberculosis H37Rv constituting extremely potent and exciting anti-tuberculosis drug leads.Tuberculosis (TB) remains one of the world's deadliest communicable diseases, novel anti-TB agents are urgently needed due to severe drug resistance and the co-epidemic of TB/HIV. Here, the authors show that anti-mycobacterial ilamycin congeners bearing unusual structural units possess extremely potent anti-tuberculosis activities.

Measurement of Total and Free Urinary Phenol and Paraben Concentrations over the Course of Pregnancy: Assessing Reliability and Contamination of Specimens in the Norwegian Mother and Child Cohort Study

PubMed Central

Longnecker, Matthew P.; Aase, Heidi; Eggesbø, Merete; Zeiner, Pål; Reichborn-Kjennerud, Ted; Knudsen, Gun P.; Bertelsen, Randi J.; Ye, Xiaoyun; Calafat, Antonia M.; Engel, Stephanie M.

2015-01-01

Background Exposures to environmental phenols and parabens may be harmful, especially in utero. Prior studies have demonstrated high within-person variability of urinary concentrations across pregnancy. Objectives We sought to measure phenol and paraben biomarker concentrations for the Norwegian Mother and Child Cohort (MoBa) study, assess within-person variability, and investigate any possible external phenol or paraben contamination of specimens. Methods We collected three spot urine samples at approximately 17, 23, and 29 weeks gestation in a hospital setting and added a preservative containing ethyl paraben. We measured urinary concentrations and within-person variability for phenols and parabens in a MoBa sample (n = 45), including a subgroup of 15 participants previously randomly selected for a bisphenol A (BPA) exposure study who had unusually high total BPA concentrations. Additionally, we compared reliability results for total, conjugated, and free concentrations of phenolic compounds. Results We detected total and free BPA, butyl paraben, propyl paraben, and methyl paraben in 100% of samples, total benzophenone-3 in 95% of samples, and infrequently detected free benzophenone-3 and total and free 2,4-dichlorophenol and 2,5-dichlorophenol. Intraclass correlation coefficients (ICCs) for total, conjugated, and free concentrations ranged from relatively low for BPA to moderate for propyl paraben. ICCs were generally similar overall and by subgroup. Conclusions Using conjugated concentrations improved reliability estimates only for BPA. Measuring total and free concentrations, an approach that may be useful for future studies, allowed us to identify likely BPA and butyl paraben contamination of archived MoBa urine specimens. Citation Guidry VT, Longnecker MP, Aase H, Eggesbø M, Zeiner P, Reichborn-Kjennerud T, Knudsen GP, Bertelsen RJ, Ye X, Calafat AM, Engel SM. 2015. Measurement of total and free urinary phenol and paraben concentrations over the course of pregnancy: assessing reliability and contamination of specimens in the Norwegian Mother and Child Cohort Study. Environ Health Perspect 123:705–711; http://dx.doi.org/10.1289/ehp.1408325 PMID:25782115

Structure and properties during aging of an ultra-high strength Al-Cu-Li-Ag-Mg alloy

NASA Technical Reports Server (NTRS)

Gayle, Frank W.; Heubaum, Frank H.; Pickens, Joseph R.

1990-01-01

The structure and properties of the strengthening phases formed during aging in an Al-Cu-Li-Ag-Mg alloy (Weldalite 049) were elulcidated, by following the development of the microstructure by means of TEM. The results of observations showed that the Weldalite 049 alloy has a series of unusual and technologically useful combinations of mechanical properties in different aging conditions, such as natural aging without prior cold work to produce high strengths, a reversion temper of lower yield strength and unusually high ductility, a room temperature reaging of the reversion temper eventually leading to the original T4 hardness, and ultrahigh-strength T6 properties.

Texture related unusual phenomena in electrodeposition and vapor deposition

NASA Astrophysics Data System (ADS)

Lee, D. N.; Han, H. N.

2015-04-01

The tensile strength of electrodeposits generally decreases with increasing bath temperature because the grain size increases and the dislocation density decreases with increasing bath temperature. Therefore, discontinuities observed in the tensile strength vs. bath temperature curves in electrodeposition of copper are unusual. The tensile strength of electrodeposits generally increases with increasing cathode current density because the rate of nucleation in electrodeposits increases with increasing current density, which in turn gives rise to a decrease in the grain size and in turn an increase in the strength. Therefore, a decrease in the tensile strength of copper electrodeposits at a high current density is unusual. The grain size of vapor deposits is expected to decrease with decreasing substrate temperature. However, rf sputtered Co-Cr deposits showed that deposits formed on water-cooled polyimide substrates had a larger grain size than deposits formed on polyimide substrates at 200 °C. These unusual phenomena can be explained by the preferred growth model for deposition texture evolution.

Winter Photochemistry Underlying High Ozone in an Oil and Gas Producing Region

NASA Astrophysics Data System (ADS)

Brown, S. S.; Edwards, P. M.; Roberts, J. M.; Ahmadov, R.; Banta, R. M.; De Gouw, J. A.; Dube, W. P.; Field, R. A.; Gilman, J.; Graus, M.; Helmig, D.; Koss, A.; Langford, A. O.; Lefer, B. L.; Lerner, B. M.; McKeen, S. A.; Li, S. M.; Murphy, S. M.; Parrish, D. D.; Senff, C. J.; Stutz, J.; Thompson, C. R.; Trainer, M.; Veres, P. R.; Warneke, C.; Wild, R. J.; Young, C.; Yuan, B.; Zamora, R. J.; Washenfelder, R. A.

2014-12-01

Ozone formation during wintertime in oil and gas producing basins of the Rocky Mountain West now accounts for some of the highest ozone pollutant concentrations observed in the U.S. These events are scientifically challenging, occurring only during cold, snow covered periods when meteorological inversions concentrate pollutants near the surface, but when incident solar actinic flux that initiates photochemical reactions is at or near its minimum. A near-explicit chemical model that incorporates detailed measurements obtained during three successive winter field studies in the Uintah Basin, Utah, accurately reproduces the observed buildup of ozone and other photochemically generated species. It also identifies the sources of free radicals that drive this unusual photochemistry, and quantifies their relative contributions. Although sharing the same basic atmospheric chemistry, winter ozone formation differs from its summertime, urban counterpart in its dependence upon the relative concentrations of volatile organic compounds (VOCs) and nitrogen oxide (NOx) precursors. Observed NO­­x mixing ratios in the Uintah basin are lower than is typical of urban areas, while VOC levels are significantly larger. These extreme VOC concentrations allow for nearly optimal efficiency of ozone production from the available NO­x. This analysis will inform the design of mitigation strategies and provide insight into the response of winter ozone to primary air pollutants in other regions, particularly those where oil and gas development is contemplated.

Unusual forest growth decline in boreal North America covaries with the retreat of Arctic sea ice.

PubMed

Girardin, Martin P; Guo, Xiao Jing; De Jong, Rogier; Kinnard, Christophe; Bernier, Pierre; Raulier, Frédéric

2014-03-01

The 20th century was a pivotal period at high northern latitudes as it marked the onset of rapid climatic warming brought on by major anthropogenic changes in global atmospheric composition. In parallel, Arctic sea ice extent has been decreasing over the period of available satellite data records. Here, we document how these changes influenced vegetation productivity in adjacent eastern boreal North America. To do this, we used normalized difference vegetation index (NDVI) data, model simulations of net primary productivity (NPP) and tree-ring width measurements covering the last 300 years. Climatic and proxy-climatic data sets were used to explore the relationships between vegetation productivity and Arctic sea ice concentration and extent, and temperatures. Results indicate that an unusually large number of black spruce (Picea mariana) trees entered into a period of growth decline during the late-20th century (62% of sampled trees; n = 724 cross sections of age >70 years). This finding is coherent with evidence encoded in NDVI and simulated NPP data. Analyses of climatic and vegetation productivity relationships indicate that the influence of recent climatic changes in the studied forests has been via the enhanced moisture stress (i.e. greater water demands) and autotrophic respiration amplified by the declining sea ice concentration in Hudson Bay and Hudson Strait. The recent decline strongly contrasts with other growth reduction events that occurred during the 19th century, which were associated with cooling and high sea ice severity. The recent decline of vegetation productivity is the first one to occur under circumstances related to excess heat in a 300-year period, and further culminates with an intensifying wildfire regime in the region. Our results concur with observations from other forest ecosystems about intensifying temperature-driven drought stress and tree mortality with ongoing climatic changes. © 2013 Her Majesty the Queen in Right of Canada Global Change Biology © 2013 John Wiley & Sons Ltd Reproduced with the permission of the Minister of Natural Resources Canada.

Uptake of antibiotics by human polymorphonuclear leukocyte cytoplasts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hand, W.L.; King-Thompson, N.L.

Enucleated human polymorphonuclear leukocytes (PMN cytoplasts), which have no nuclei and only a few granules, retain many of the functions of intact neutrophils. To better define the mechanisms and intracellular sites of antimicrobial agent accumulation in human neutrophils, we studied the antibiotic uptake process in PMN cytoplasts. Entry of eight radiolabeled antibiotics into PMN cytoplasts was determined by means of a velocity gradient centrifugation technique. Uptakes of these antibiotics by cytoplasts were compared with our findings in intact PMN. Penicillin entered both intact PMN and cytoplasts poorly. Metronidazole achieved a concentration in cytoplasts (and PMN) equal to or somewhat lessmore » than the extracellular concentration. Chloramphenicol, a lipid-soluble drug, and trimethoprim were concentrated three- to fourfold by cytoplasts. An unusual finding was that trimethroprim, unlike other tested antibiotics, was accumulated by cytoplasts more readily at 25 degrees C than at 37 degrees C. After an initial rapid association with cytoplasts, cell-associated imipenem declined progressively with time. Clindamycin and two macrolide antibiotics (roxithromycin, erythromycin) were concentrated 7- to 14-fold by cytoplasts. This indicates that cytoplasmic granules are not essential for accumulation of these drugs. Adenosine inhibited cytoplast uptake of clindamycin, which enters intact phagocytic cells by the membrane nucleoside transport system. Roxithromycin uptake by cytoplasts was inhibited by phagocytosis, which may reduce the number of cell membrane sites available for the transport of macrolides. These studies have added to our understanding of uptake mechanisms for antibiotics which are highly concentrated in phagocytes.« less

Accessible silanol sites - beneficial for the RP-HPLC separation of constitutional and diastereomeric azaspirovesamicol isomers.

PubMed

Wenzel, Barbara; Fischer, Steffen; Brust, Peter; Steinbach, Jörg

2010-12-10

Different RP-HPLC columns (phenyl, conventional ODS, cross-linked C(18) and special end-capped C(8) and C(18) phases) were used to investigate the separation of four basic ionizable isomers. Using ACN/20mM NH(4)OAc aq., a separation was observed exclusively on RP columns with higher silanol activity at unusual high ACN concentration, indicating cation-exchange as main retention mechanism. Using MeOH/20mM NH(4)OAc aq., another separation at low MeOH concentrations was observed on both, RP columns with higher as well as RP columns with lower silanol activity, which is mainly based on hydrophobic interactions. The isomers were also separated on a bare silica column at higher MeOH content using NH(4)OAc. Since cation-exchange governs this retention, the elution order was different compared to the RP phases. A strong retention on the silica column was observed in ACN, which could be attributed to partition processes as additional retention mechanism. Copyright © 2010 Elsevier B.V. All rights reserved.

Lithiation-Assisted Strengthening Effect and Reactive Flow in Bulk and Nano-Confined Sulfur Cathodes of Lithium-Sulfur Batteries

NASA Astrophysics Data System (ADS)

Wang, Mingchao; Yu, Jingui; Lin, Shangchao

Sulfur (S) serves as a promising cathode material in Li-ion batteries owing to its abundance on earth, low cost and high theoretical specific capacity 1670 mAhg-1, which is 3-5 times higher than that of current commercial Li-ion batteries. Nowadays, the most popular strategies of using S cathode are based on producing nanostructured carbon matrices (i.e. hollow carbon nanospheres and nanofibers) to sustain S cathode loading. However, the possible stress evolution and mechanical degradation of the confined S cathode in those carbon matrices have never been explored before. In addition, the associated structural and conductivity changes of the confined S cathode during the lithiation/delithiation process plays a significant role in the battery performance. With the above in mind, here we conduct reactive molecular dynamics simulations to investigate the microstructural and stress evolution of the confined S cathode during lithiation/delithiation process. Simulation results indicate an unusual stress relaxation state in LixS compounds at lower Li concentrations (x >0.7). The strength of corresponding Li-S compounds also increases with respect to the Li concentration.

Contrasted nitrogen utilization in annual C 3 grass and legume crops: Physiological explorations and ecological considerations

NASA Astrophysics Data System (ADS)

Del Pozo, Alejandro; Garnier, Eric; Aronson, James

2000-01-01

Although it is well known that legumes have unusually high levels of nitrogen in both reproductive and vegetative organs, the physiological implications of this pattern have been poorly assessed. We conducted a literature survey and used data from two (unpublished) experiments on annual legumes and C 3 grasses in order to test whether these high nitrogen concentrations in legumes are correlated to high rates of carbon gain. Three different temporal/spatial scales were considered: full growing season/stand, days to month/whole plant and seconds/leaf. At the stand level, and for plants grown under both extratropical and tropical settings, biomass per unit organic-nitrogen was lower in legume than in grass crops. At a shorter time scale, the relative growth rate per unit plant nitrogen (`nitrogen productivity') was lower in faba bean ( Vicia faba var. minor cv. Tina) than in wheat ( Triticum aestivum cv. Alexandria), and this was confirmed in a comparison of two wild, circum-Mediterranean annuals - Medicago minima, a legume, and Bromus madritensis, a grass. Finally, at the leaf level, a synthesis of published data comparing soybean ( Glycine max) and rice ( Oryza sativa) on the one hand, and our own data on faba bean and wheat on the other hand, demonstrates that the photosynthetic rate per unit leaf nitrogen (the photosynthetic nitrogen use efficiency) is consistently lower in legumes than in grasses. These results demonstrate that, regardless of the scale considered and although the organic-nitrogen concentration in vegetative organs of legumes is higher than in grasses, this does not lead to higher rates of carbon gain in the former. Various physiological factors affecting the efficiency of nitrogen utilization at the three time scales considered are discussed. The suggestion is made that the ecological significance of the high nitrogen concentration in legumes may be related to a high nitrogen demand for high quality seed production at a time when nitrogen fixation is shut off rather than to a high production potential.

Enantioseparation of angiotensin II receptor type 1 blockers: evaluation of 6-substituted carbamoyl benzimidazoles on immobilized polysaccharide-based chiral stationary phases. Unusual temperature behavior.

PubMed

Su, Ran; Hou, Zhun; Sang, Lihong; Zhou, Zhi-Ming; Fang, Hao; Yang, Xinying

2017-09-15

Enantioseparation of thirteen 6-substituted carbamoyl benzimidazoles by high-performance liquid chromatography (HPLC) was investigated using two immobilized polysaccharide-based chiral stationary phases (CSPs), Chiralpak IC and Chiralpak IA, in normal-phase mode. Most of the examined compounds were completely resolved. The effects of a polar alcohol modifier, analyte structure, and column temperature on the chiral recognition were investigated. Furthermore, the structure-retention relationship was evaluated, and thermodynamic parameters were calculated from plots of ln k' or ln α versus 1/T. The thermodynamic parameters indicated that the separations were enthalpy-driven. Moreover, nonlinear van't Hoff plots were obtained on Chiralpak IA. However, two unusual phenomena were observed: (1) an unusual increase in retention with increasing temperature with linear van't Hoff plots on Chiralpak IC and (2) an extremely high T iso value (i.e., several thousand degrees centigrade). Copyright © 2017 Elsevier B.V. All rights reserved.

Unusual Entropy of Adsorbed Methane on Zeolite-Templated Carbon

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stadie, Nicholas P.; Murialdo, Maxwell; Ahn, Channing C.

2015-11-25

Methane adsorption at high pressures and across a wide range of temperatures was investigated on the surface of three porous carbon adsorbents with complementary structural properties. The measured adsorption equilibria were analyzed using a method that can accurately account for nonideal fluid properties and distinguish between absolute and excess quantities of adsorption, and that also allows the direct calculation of the thermodynamic potentials relevant to adsorption. On zeolite-templated carbon (ZTC), a material that exhibits extremely high surface area with optimal pore size and homogeneous structure, methane adsorption occurs with unusual thermodynamic properties that are greatly beneficial for deliverable gas storage:more » an enthalpy of adsorption that increases with site occupancy, and an unusually low entropy of the adsorbed phase. The origin of these properties is elucidated by comparison of the experimental results with a statistical mechanical model. The results indicate that temperature-dependent clustering (i.e., reduced configurations) of the adsorbed phase due to enhanced lateral interactions can account for the peculiarities of methane adsorbed on ZTC.« less

Childhood nodal marginal zone lymphoma with unusual clinicopathologic and cytogenetic features for the pediatric variant: a case report.

PubMed

Aqil, Barina; Merritt, Brian Y; Elghetany, M Tarek; Kamdar, Kala Y; Lu, Xinyan Y; Curry, Choladda V

2015-01-01

Nodal marginal zone lymphoma (NMZL) is a B-cell lymphoma that shares morphologic and immunophenotypic features with extranodal and splenic marginal zone lymphomas but lacks extranodal or splenic involvement at presentation. NMZL occurs mostly in adults with no sex predilection, at advanced stage (III or IV), with frequent relapses and a high incidence of tumoral genetic abnormalities including trisomies 3 and 18 and gain of 7q. Pediatric NMZL, however, is a rare but distinct variant of NMZL with characteristic features including male predominance, asymptomatic and localized (stage I) disease, low relapse rates with excellent outcomes, and a lower incidence of essentially similar genetic aberrations compared to adult NMZL. Here we describe a unique case of childhood NMZL with unusual clinicopathologic features for the pediatric variant including generalized lymphadenopathy, high-stage disease with persistence after therapy, unusual immunophenotype (CD5, CD23, and BCL6 positive), and unique chromosomal abnormalities including monosomy 20 and add(10)(p11.2).

Science of Global Climate Modeling: Confirmation from Discoveries on Mars

NASA Astrophysics Data System (ADS)

Hartmann, William K.

2012-10-01

As early as 1993, analysis of obliquity changes on Mars revealed irregular cycles of high excursion, over 45°1. Further obliquity analyses indicated that insolation and climatic conditions vary with time, with the four most recent episodes of obliquity >45° occurring about 5.5, 8, 9, and 15 My.2 Various researchers applied global climate models, using Martian parameters and obliquity changes. The models (independent of Martian geomorphological observations) indicate exceptional climate conditions during the high-obliquity episodes at >45°3,4, with localized massive ice deposition effects east of Hellas and on the west slopes of Tharsis.5 At last year’s DPS my co-authors and I detailed evidence of unusual active glaciation in Greg crater, near the center of the predicted area of ice accumulation during high obliquity.6 We found that the timescale of glacial surface layer activity matches the general 5-15 My timescale of the last episodes of high obliquity and ice deposition. Radar results confirm ice deposits in debris aprons concentrated in the same area.7 Less direct evidence has also been found for glacial ice deposits in the west Tharsis region.8 Here I emphasize that if the models can be adjusted to Mars and then successfully indicate unusual, specific features that we see there, it is an argument for the robustness of climate modeling in general. In recent years we have see various public figures casting doubt on the validity of terrestrial global modeling. The successful match of Martian climate modeling with direct Martian geological and chronometric observations provides an interesting and teachable refutation of the attacks on climate science. References: 1. Science 259:1294-1297; 2. LPSC XXXV, Abs. 1600; 3. Nature 412:411-413; 4. Science 295:110-113; 5. Science 311:368-371; 6. EPSC-DPS Abs. 1394; 7. Science 322:1235-1238; 8. Nature 434:346-351.

Characterization of the Unusual Product from the Reaction between Cobalt(II) Chloride, Ethane-1,2-diamine, and Hydrochloric Acid: An Undergraduate Project Involving an Unknown Metal Complex.

ERIC Educational Resources Information Center

Curtis, Neil F.; And Others

1986-01-01

Discusses the need for student research-type chemistry projects based upon "unknown" metal complexes. Describes an experiment involving the product from the reaction between cobalt(II) chloride, ethane-1,2-diamine (en) and concentrated hydrochloric acid. Outlines the preparation of the cobalt complex, along with procedure, results and…

Sunset

NASA Technical Reports Server (NTRS)

1992-01-01

This cross section of the Earth's atmosphere at sunset and earth limb (24.5S, 43.5E) displays an unusual layering believed to be caused by temperature inversions which effectively concentrate smoke, dust and aerosols into narrow layers. the top of the stratosphere can be seen as the top of the white layer thought to contain volcanic debris. The purple layer is the troposphere containing smoke from landclearing biomass burning.

Sunset

NASA Image and Video Library

1992-11-01

This cross section of the Earth's atmosphere at sunset and earth limb (24.5S, 43.5E) displays an unusual layering believed to be caused by temperature inversions which effectively concentrate smoke, dust and aerosols into narrow layers. the top of the stratosphere can be seen as the top of the white layer thought to contain volcanic debris. The purple layer is the troposphere containing smoke from landclearing biomass burning.

Graphene-coated materials using silica particles as a framework for highly efficient removal of aromatic pollutants in water

PubMed Central

Yang, Kaijie; Chen, Baoliang; Zhu, Lizhong

2015-01-01

The substantial aggregation of pristine graphene nanosheets decreases its powerful adsorption capacity and diminishes its practical applications. To overcome this shortcoming, graphene-coated materials (GCMs) were prepared by loading graphene onto silica nanoparticles (SiO2). With the support of SiO2, the stacked interlamination of graphene was held open to expose the powerful adsorption sites in the interlayers. The adsorption of phenanthrene, a model aromatic pollutant, onto the loaded graphene nanosheets increased up to 100 fold compared with pristine graphene at the same level. The adsorption of GCMs increased with the loading amount of the graphene nanosheets and dramatically decreased with the introduction of oxygen-containing groups in the graphene nanosheets. The highly hydrophobic effect and the strong π-π stacking interactions of the exposed graphene nanosheets contributed to their superior adsorption of GCMs. An unusual GCM peak adsorption coefficient (Kd) was observed with the increase in sorbate concentration. The sorbate concentration at peak Kd shifted to lower values for the reduced graphene oxide and graphene relative to the graphene oxide. Therefore, the replacement of water nanodroplets attached to the graphene nanosheets through weak non-hydrogen bonding with phenanthrene molecules via strong π-π stacking interactions is hypothesized to be an additional adsorption mechanism for GCMs. PMID:26119007

A persistent organic pollutant related with unusual high frequency of hermaphroditism in the neotropical anuran Physalaemus cuvieri Fitzinger, 1826.

PubMed

Moresco, Rafaela M; Margarido, Vladimir P; de Oliveira, Classius

2014-07-01

Representing a reflection of anthropic activity, the level of xenobiotic compounds in aquatic ecosystems has increased in recent years, bringing severe damage to the environment. The present work reports the occurrence of malformation in gonads of Physalaemus cuvieri individuals from a population of Atlantic Forest in Southern Brazil. Twenty male specimens were collected, which had their testicles removed, immersed in Karnovsky fixative solution, included in historesin for 2 μm cuts and stained with Hematoxylin-eosin. Four specimens showed intersexual gonads condition along with the presence of sperm and oocytes. In order to test a possible contamination of water, 2L were collected from the water body to check organochlorine, organophosphate and carbamate compounds. The analysis of water showed the presence of agrotoxic Dieldrin in a concentration of 0.05 μg/L, representing a concentration above the recommended reference. This agrotoxic, in addition to acting as endocrine disrupter and commercially prohibited, has quite persistent residual effects, and may be responsible for the high frequency of P. cuvieri with intersexual gonads, which in the long term can represent a risk for this population due to the potential impact on its effective reproductive ability. Copyright © 2014 Elsevier Inc. All rights reserved.

Graphene-coated materials using silica particles as a framework for highly efficient removal of aromatic pollutants in water

NASA Astrophysics Data System (ADS)

Yang, Kaijie; Chen, Baoliang; Zhu, Lizhong

2015-06-01

The substantial aggregation of pristine graphene nanosheets decreases its powerful adsorption capacity and diminishes its practical applications. To overcome this shortcoming, graphene-coated materials (GCMs) were prepared by loading graphene onto silica nanoparticles (SiO2). With the support of SiO2, the stacked interlamination of graphene was held open to expose the powerful adsorption sites in the interlayers. The adsorption of phenanthrene, a model aromatic pollutant, onto the loaded graphene nanosheets increased up to 100 fold compared with pristine graphene at the same level. The adsorption of GCMs increased with the loading amount of the graphene nanosheets and dramatically decreased with the introduction of oxygen-containing groups in the graphene nanosheets. The highly hydrophobic effect and the strong π-π stacking interactions of the exposed graphene nanosheets contributed to their superior adsorption of GCMs. An unusual GCM peak adsorption coefficient (Kd) was observed with the increase in sorbate concentration. The sorbate concentration at peak Kd shifted to lower values for the reduced graphene oxide and graphene relative to the graphene oxide. Therefore, the replacement of water nanodroplets attached to the graphene nanosheets through weak non-hydrogen bonding with phenanthrene molecules via strong π-π stacking interactions is hypothesized to be an additional adsorption mechanism for GCMs.

Graphene-coated materials using silica particles as a framework for highly efficient removal of aromatic pollutants in water.

PubMed

Yang, Kaijie; Chen, Baoliang; Zhu, Lizhong

2015-06-29

The substantial aggregation of pristine graphene nanosheets decreases its powerful adsorption capacity and diminishes its practical applications. To overcome this shortcoming, graphene-coated materials (GCMs) were prepared by loading graphene onto silica nanoparticles (SiO2). With the support of SiO2, the stacked interlamination of graphene was held open to expose the powerful adsorption sites in the interlayers. The adsorption of phenanthrene, a model aromatic pollutant, onto the loaded graphene nanosheets increased up to 100 fold compared with pristine graphene at the same level. The adsorption of GCMs increased with the loading amount of the graphene nanosheets and dramatically decreased with the introduction of oxygen-containing groups in the graphene nanosheets. The highly hydrophobic effect and the strong π-π stacking interactions of the exposed graphene nanosheets contributed to their superior adsorption of GCMs. An unusual GCM peak adsorption coefficient (Kd) was observed with the increase in sorbate concentration. The sorbate concentration at peak Kd shifted to lower values for the reduced graphene oxide and graphene relative to the graphene oxide. Therefore, the replacement of water nanodroplets attached to the graphene nanosheets through weak non-hydrogen bonding with phenanthrene molecules via strong π-π stacking interactions is hypothesized to be an additional adsorption mechanism for GCMs.

Exotic s-wave superconductivity in alkali-doped fullerides.

PubMed

Nomura, Yusuke; Sakai, Shiro; Capone, Massimo; Arita, Ryotaro

2016-04-20

Alkali-doped fullerides (A3C60 with A = K, Rb, Cs) show a surprising phase diagram, in which a high transition-temperature (Tc) s-wave superconducting state emerges next to a Mott insulating phase as a function of the lattice spacing. This is in contrast with the common belief that Mott physics and phonon-driven s-wave superconductivity are incompatible, raising a fundamental question on the mechanism of the high-Tc superconductivity. This article reviews recent ab initio calculations, which have succeeded in reproducing comprehensively the experimental phase diagram with high accuracy and elucidated an unusual cooperation between the electron-phonon coupling and the electron-electron interactions leading to Mott localization to realize an unconventional s-wave superconductivity in the alkali-doped fullerides. A driving force behind the exotic physics is unusual intramolecular interactions, characterized by the coexistence of a strongly repulsive Coulomb interaction and a small effectively negative exchange interaction. This is realized by a subtle energy balance between the coupling with the Jahn-Teller phonons and Hund's coupling within the C60 molecule. The unusual form of the interaction leads to a formation of pairs of up- and down-spin electrons on the molecules, which enables the s-wave pairing. The emergent superconductivity crucially relies on the presence of the Jahn-Teller phonons, but surprisingly benefits from the strong correlations because the correlations suppress the kinetic energy of the electrons and help the formation of the electron pairs, in agreement with previous model calculations. This confirms that the alkali-doped fullerides are a new type of unconventional superconductors, where the unusual synergy between the phonons and Coulomb interactions drives the high-Tc superconductivity.

The nature of unusual luminescence in natural calcite, CaCO3

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gaft, M.; Nagli, L.; Panczer, G.

2008-11-01

The unusual luminescence of particular varieties of natural pink calcite (CaCO{sub 3}) samples was studied by laser-induced time-resolved luminescence spectroscopy at different temperatures. The luminescence is characterized by intense blue emission under short-wave UV lamp excitation with an extremely long decay time, accompanied by pink-orange luminescence under long wave UV excitation. Our investigation included optical absorption, natural thermostimulated luminescence (NTL) and Laser-Induced Breakdown Spectroscopy (LIBS) studies. Two luminescence centers were detected: a narrow violet band, with {lambda}{sub max} = 412 nm, {Delta} = 45 nm, two decay components of {tau}{sub 1} = 5 ns and {tau}{sub 2} = 7.2 ms,more » accompanied by very long afterglow, and an orange emission band with {lambda}{sub max} = 595 nm, {Delta} = 90 nm and {tau} = 5 ns. Both luminescence centers are thermally unstable with the blue emission disappearing after heating at 500 C, and the orange emission disappearing after heating at different temperatures starting from 230 C, although sometimes it is stable up to 500 C in different samples. Both centers have spectral-kinetic properties very unusual for mineral luminescence, which in combination with extremely low impurity concentrations, prevent their identification with specific impurity related emission. The most likely explanation of these observations may be the presence of radiation-induced luminescence centers. The long violet afterglow is evidently connected with trapped charge carrier liberation, with their subsequent migration through the valence band and ultimate recombination with a radiation-induced center responsible for the unusual violet luminescence.« less

Design and optimization of non-clogging counter-flow microconcentrator for enriching epidermoid cervical carcinoma cells.

PubMed

Tran-Minh, Nhut; Dong, Tao; Su, Qianhua; Yang, Zhaochu; Jakobsen, Henrik; Karlsen, Frank

2011-02-01

Clogging failure is common for microfilters in living cells concentration; for instance, the CaSki Cell-lines (Epidermoid cervical carcinoma cells) utilizing the flat membrane structure. In order to avoid the clogging, counter-flow concentration units with turbine blade-like micropillar are proposed in microconcentrator design. Due to the unusual geometrical-profiles and extraordinary microfluidic performance, the cells blocking does not occur even at permeate entrances. A counter-flow microconcentrator was designed, with both processing layer and collecting layer arranged in terms of the fractal based honeycomb structure. The device was optimized by coupling Artificial Neuron Network (ANN) and Computational Fluid Dynamics (CFD). The excellent concentration ratio of a final microconcentrator was presented in numerical results.

Elemental Analysis of Zircon by High Mass Resolution USGS-Stanford SHRIMP-RG: Measuring and Evaluating Ti-in-zircon Temperatures and Compositional Characteristics

NASA Astrophysics Data System (ADS)

Wooden, J. L.; Mazdab, F. K.; Claiborne, L. L.; Miller, C. F.; Barth, A. P.

2006-12-01

High mass resolution of SHRIMP-RG permits measurement of a large set of trace elements for zircon, including 48Ti, Sc, and Nb (requiring better than 9,000 MR) and Be, B, F, P, 49Ti, V, Y, all the REE, Hf, Th, and U (Mazdab and Wooden 2006). A 15-20 micron spot allows analysis of numerous discrete CL zones from single zircons with minimal contributions from unknown material below the exposed surface. Data from suites of zircons from more than 20 individual granitoid samples suggest several general observations: (1) Temperatures calculated by Ti-in-zircon (Watson et al 2006) are entirely compatible with petrologic constraints; uncertainty in a(TiO2) introduces uncertainty in calculated T, but for reasonable values between 0.5 and 0.8 T's consistently fall between 650 and 900 C, mostly in the lower half of the range; (2) T can vary by 150-200 C within suites of zircons from individual samples and even in single zircons, where zonation may be normal (high to low, core to rim), reverse (low to high) or fluctuating; (3) Hf concentrations increase with decreasing T because of Zr/Hf fractionation between zircon and melt (Claiborne et al in press); (4) Many elements and element ratios show a co-variation with T and Hf concentration e.g., Th/U and MREE/HREE decrease with increasing Hf and decreasing T. Hf concentrations can continue to increase after a minimum T is reached, indicating continuing zircon growth from remaining (near eutectic?) melt. Yb/Gd (steepness of the HREE pattern) is an excellent monitor of fractionation, particularly at lower T (below 750 C) where the ratio increases rapidly. This trend may result from co-fractionation of accessory minerals and/or be driven by the thermodynamics of crystal growth, and/or may involve other factors and processes as yet poorly understood. Magmatic zircons commonly have a negative Eu anomaly of about 0.5 or lower which may change little or become more pronounced with falling T; anomalies probably reflect feldspar fractionation rather than magmatic oxidation conditions. Zircons typically have positive Ce anomalies that rise as T falls and Hf increases. This reflects either fractionation of minerals that incorporate Ce+3 but little Ce+4, or oxidation. U and Th concentrations are typically highest in low-T zones but often show very irregular patterns with T and Hf. Molar ratios of total 3+ ions over P are mostly 1-5, suggesting charge compensation other than the xenotime substitution (Mazdab and Wooden 2006). Random analyses of zircons for T and composition are of limited use given wide variation within single zircons. Process interpretations should be based on trends observed in multiple zircons from individual samples, as many samples have characteristics distinct from general trends. Hydrothermal zircon (Hoskin 2005) is not unusual as a rim zone and may reflect a fine intergrowth of other minerals (apatite, titanite, oxides) or unusual late stage growth conditions. Ti temperatures from these zones are often unreliable, and all analyses for Ti and trace elements should include screens (i.e. F, Al, Ca, Fe) for Ti-bearing minerals and other accessories. While trace element concentrations of zircons may not be diagnostic of rock types in general, careful analyses as described above provide invaluable information about magmatic and metamorphic processes.

Simulation study of sulfonate cluster swelling in ionomers

NASA Astrophysics Data System (ADS)

Allahyarov, Elshad; Taylor, Philip L.; Löwen, Hartmut

2009-12-01

We have performed simulations to study how increasing humidity affects the structure of Nafion-like ionomers under conditions of low sulfonate concentration and low humidity. At the onset of membrane hydration, the clusters split into smaller parts. These subsequently swell, but then maintain constant the number of sulfonates per cluster. We find that the distribution of water in low-sulfonate membranes depends strongly on the sulfonate concentration. For a relatively low sulfonate concentration, nearly all the side-chain terminal groups are within cluster formations, and the average water loading per cluster matches the water content of membrane. However, for a relatively higher sulfonate concentration the water-to-sulfonate ratio becomes nonuniform. The clusters become wetter, while the intercluster bridges become drier. We note the formation of unusual shells of water-rich material that surround the sulfonate clusters.

Boron uptake, localization, and speciation in marine brown algae.

PubMed

Miller, Eric P; Wu, Youxian; Carrano, Carl J

2016-02-01

In contrast to the generally boron-poor terrestrial environment, the concentration of boron in the marine environment is relatively high (0.4 mM) and while there has been extensive interest in its use as a surrogate of pH in paleoclimate studies in the context of climate change-related questions, the relatively depth independent, and the generally non-nutrient-like concentration profile of this element have led to boron being neglected as a potentially biologically relevant element in the ocean. Among the marine plant-like organisms the brown algae (Phaeophyta) are one of only five lineages of photosynthetic eukaryotes to have evolved complex multicellularity. Many of unusual and often unique features of brown algae are attributable to this singular evolutionary history. These adaptations are a reflection of the marine coastal environment which brown algae dominate in terms of biomass. Consequently, brown algae are of fundamental importance to oceanic ecology, geochemistry, and coastal industry. Our results indicate that boron is taken up by a facilitated diffusion mechanism against a considerable concentration gradient. Furthermore, in both Ectocarpus and Macrocystis some boron is most likely bound to cell wall constituent alginate and the photoassimilate mannitol located in sieve cells. Herein, we describe boron uptake, speciation, localization and possible biological function in two species of brown algae, Macrocystis pyrifera and Ectocarpus siliculosus.

Outlier Detection in Urban Air Quality Sensor Networks.

PubMed

van Zoest, V M; Stein, A; Hoek, G

2018-01-01

Low-cost urban air quality sensor networks are increasingly used to study the spatio-temporal variability in air pollutant concentrations. Recently installed low-cost urban sensors, however, are more prone to result in erroneous data than conventional monitors, e.g., leading to outliers. Commonly applied outlier detection methods are unsuitable for air pollutant measurements that have large spatial and temporal variations as occur in urban areas. We present a novel outlier detection method based upon a spatio-temporal classification, focusing on hourly NO 2 concentrations. We divide a full year's observations into 16 spatio-temporal classes, reflecting urban background vs. urban traffic stations, weekdays vs. weekends, and four periods per day. For each spatio-temporal class, we detect outliers using the mean and standard deviation of the normal distribution underlying the truncated normal distribution of the NO 2 observations. Applying this method to a low-cost air quality sensor network in the city of Eindhoven, the Netherlands, we found 0.1-0.5% of outliers. Outliers could reflect measurement errors or unusual high air pollution events. Additional evaluation using expert knowledge is needed to decide on treatment of the identified outliers. We conclude that our method is able to detect outliers while maintaining the spatio-temporal variability of air pollutant concentrations in urban areas.

Sorbitol, Rubus fruit, and misconception.

PubMed

Lee, Jungmin

2015-01-01

It is unclear how the misunderstanding that Rubus fruits (e.g., blackberries, raspberries) are high in sugar alcohol began, or when it started circulating in the United States. In reality, they contain little sugar alcohol. Numerous research groups have reported zero detectable amounts of sugar alcohol in fully ripe Rubus fruit, with the exception of three out of 82 Rubus fruit samples (cloudberry 0.01 g/100 g, red raspberry 0.03 g/100 g, and blackberry 4.8 g/100 g(∗); (∗)highly unusual as 73 other blackberry samples contained no detectable sorbitol). Past findings on simple carbohydrate composition of Rubus fruit, other commonly consumed Rosaceae fruit, and additional fruits (24 genera and species) are summarised. We are hopeful that this review will clarify Rosaceae fruit sugar alcohol concentrations and individual sugar composition; examples of non-Rosaceae fruit and prepared foods containing sugar alcohol are included for comparison. A brief summary of sugar alcohol and health will also be presented. Published by Elsevier Ltd.

High-ionic-strength electroosmotic flows in uncharged hydrophobic nanochannels.

PubMed

Kim, Daejoong; Darve, Eric

2009-02-01

We report molecular dynamics simulation results of high-ionic-strength electroosmotic flows inside uncharged nanochannels. The possibility of this unusual electrokinetic phenomenon has been discussed by Dukhin et al. [A. Dukhin, S. Dukhin, P. Goetz, Langmuir 21 (2005) 9990]. Our computed velocity profiles clearly indicate the presence of a net flow with a maximum velocity around 2 m/s. We found the apparent zeta potential to be -29.7+/-6.8 mV, using the Helmholtz-Smoluchowski relation and the measured mean velocity. This value is comparable to experimentally measured values in Dukhin et al. and references therein. We also investigate the orientations of water molecules in response to an electric field by computing polarization density. Water molecules in the bulk region are oriented along the direction of the external electric field, while their near-wall orientation shows oscillations. The computation of three-dimensional density distributions of sodium and chloride ions around each individual water molecule show that chloride ions tend to concentrate near a water molecule, whereas sodium ions are diffusely distributed.

Vacancy-controlled ultrastable nanoclusters in nanostructured ferritic alloys

PubMed Central

Zhang, Z. W.; Yao, L.; Wang, X.-L.; Miller, M. K.

2015-01-01

A new class of advanced structural materials, based on the Fe-O-vacancy system, has exceptional resistance to high-temperature creep and excellent tolerance to extremely high-dose radiation. Although these remarkable improvements in properties compared to steels are known to be associated with the Y-Ti-O-enriched nanoclusters, the roles of vacancies in facilitating the nucleation of nanoclusters are a long-standing puzzle, due to the experimental difficulties in characterizing vacancies, particularly in-situ while the nanoclusters are forming. Here we report an experiment study that provides the compelling evidence for the presence of significant concentrations of vacancies in Y-Ti-O-enriched nanoclusters in a nanostructured ferritic alloy using a combination of state-of-the-art atom-probe tomography and in situ small angle neutron scattering. The nucleation of nanoclusters starts from the O-enriched solute clustering with vacancy mediation. The nanoclusters grow with an extremely low growth rate through attraction of vacancies and O:vacancy pairs, leading to the unusual stability of the nanoclusters. PMID:26023747

Vacancy-controlled ultrastable nanoclusters in nanostructured ferritic alloys

DOE PAGES

Zhang, Z. W.; Yao, L.; Wang, X. -L.; ...

2015-05-29

A new class of advanced structural materials, based on the Fe-O-vacancy system, has exceptional resistance to high-temperature creep and excellent tolerance to extremely high-dose radiation. Although these remarkable improvements in properties compared to steels are known to be associated with the Y-Ti-O-enriched nanoclusters, the roles of vacancies in facilitating the nucleation of nanoclusters are a long-standing puzzle, due to the experimental difficulties in characterizing vacancies, particularly in-situ while the nanoclusters are forming. We report an experiment study that provides the compelling evidence for the presence of significant concentrations of vacancies in Y-Ti-O-enriched nanoclusters in a nanostructured ferritic alloy using amore » combination of state-of-the-art atom-probe tomography and in situ small angle neutron scattering. The nucleation of nanoclusters starts from the O-enriched solute clustering with vacancy mediation. The nanoclusters grow with an extremely low growth rate through attraction of vacancies and O:vacancy pairs, leading to the unusual stability of the nanoclusters.« less

Ecological effects of nitrogen deposition in the western United States

USGS Publications Warehouse

Fenn, M.E.; Baron, Jill S.; Allen, E.B.; Rueth, H.M.; Nydick, K.R.; Geiser, L.; Bowman, W.D.; Sickman, J.O.; Meixner, T.; Johnson, D.W.; Neitlich, P.

2003-01-01

In the western United States vast acreages of land are exposed to low levels of atmospheric nitrogen (N) deposition, with interspersed hotspots of elevated N deposition downwind of large, expanding metropolitan centers or large agricultural operations. Biological response studies in western North America demonstrate that some aquatic and terrestrial plant and microbial communities are significantly altered by N deposition. Greater plant productivity is counterbalanced by biotic community changes and deleterious effects on sensitive organisms (lichens and phytoplankton) that respond to low inputs of N (3 to 8 kilograms N per hectare per year). Streamwater nitrate concentrations are elevated in high-elevation catchments in Colorado and are unusually high in southern California and in some chaparral catchments in the southwestern Sierra Nevada. Chronic N deposition in the West is implicated in increased fire frequency in some areas and habitat alteration for threatened species. Between hotspots, N deposition is too low to cause noticeable effects or has not been studied.

PCR/oligonucleotide probe typing of HLA class II alleles in a Filipino population reveals an unusual distribution of HLA haplotypes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bugawan, T.L.; Chang, J.D.; Erlich, H.A.

1994-02-01

The authors have analyzed the distribution of HLA class II alleles and haplotypes in a Filipino population by PCR amplification of the DRB1, DQB1, and DPB1 second-exon sequences from buccal swabs obtained from 124 family members and 53 unrelated individuals. The amplified DNA was typed by using nonradioactive sequence-specific oligonucleotide probes. Twenty-two different DRB1 alleles, including the novel Filipino *1105, and 46 different DRB1/DQB1 haplotypes, including the unusual DRB1*0405-DQB1*0503, were identified. An unusually high frequency (f = .383) of DPB1*0101, a rare allele in other Asian populations, was also observed. In addition, an unusual distribution of DRB1 alleles and haplotypesmore » was seen in this population, with DR2 (f = .415) and DRB1*1502-DQB1*0502 (f = .233) present at high frequencies. This distribution of DRB1 alleles differs from the typical HLA population distribution, in which the allele frequencies are more evenly balanced. The distribution of HLA class II alleles and haplotypes in this Filipino population is different from that of other Asian and Pacific groups: of those populations studied to date, the Indonesian population is the most similar. DRB1*1502-DQB1*0502 was in strong linkage disequilibrium (D[prime] = .41) with DPB 1*0101 (f = .126, for the extended haplotype), which is consistent with selection for this DR, DQ, DP haplotype being responsible for the high frequency of these three class II alleles in this populations. 30 refs., 2 figs., 6 tabs.« less

AlGaAs diode pumped tunable chromium lasers

DOEpatents

Krupke, William F.; Payne, Stephen A.

1992-01-01

An all-solid-state laser system is disclosed wherein the laser is pumped in the longwave wing of the pump absorption band. By utilizing a laser material that will accept unusually high dopant concentrations without deleterious effects on the crystal lattice one is able to compensate for the decreased cross section in the wing of the absorption band, and the number of pump sources which can be used with such a material increases correspondingly. In a particular embodiment a chromium doped colquiriite-structure crystal such as Cr:LiSrAlF.sub.6 is the laser material. The invention avoids the problems associated with using AlGaInP diodes by doping the Cr:LiSrAlF.sub.6 heavily to enable efficient pumping in the longwave wing of the absorption band with more practical AlGaAs diodes.

Elemental Levels Analyzed by PIXE in Florida Alligators

NASA Astrophysics Data System (ADS)

Kuharik, J. C.; Kravchenko, I. I.; Dunnam, F. E.; Van Rinsvelt, H. A.; Ross, J. P.

2003-08-01

Unusual and alarming mortality of alligators (Alligator mississippiensis) has been reported from Lake Griffin, Florida, where almost 400 dead alligators have been observed since 1997. In addition, the hatch rate for alligator eggs around Lake Griffin fell below 10% and remains low (30-45%) while the normal hatch rate is typically 80%. Standard diagnostic methods have been ineffective in determining the cause of the phenomenon. Many possibilities have been considered including pollutants, nutrition, and toxic algae. Particle Induced X-ray Emission (PIXE) analysis is highly suitable for investigating concentrations of a wide range of elements in animal tissue. Liver, kidney and spinal cord tissues from healthy and sick alligators have been analyzed by PIXE for elemental content. Initial results showed positive correlation between certain elements and neural impairment and morbidity of alligators in Lake Griffin, but have failed to prove significant.

Rhodium(I)-catalyzed cyclization of allenynes with a carbonyl group through unusual insertion of a C-O bond into a rhodacycle intermediate.

PubMed

Oonishi, Yoshihiro; Yokoe, Takayuki; Hosotani, Akihito; Sato, Yoshihiro

2014-01-20

Rhodium(I)-catalyzed cyclization of allenynes with a tethered carbonyl group was investigated. An unusual insertion of a CO bond into the C(sp(2) )-rhodium bond of a rhodacycle intermediate occurs via a highly strained transition state. Direct reductive elimination from the obtained rhodacyle intermediate proceeds to give a tricyclic product containing an 8-oxabicyclo[3.2.1]octane skeleton, while β-hydride elimination from the same intermediate gives products that contain fused five- and seven-membered rings in high yields. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Magnetic field drift shell splitting - Cause of unusual dayside particle pitch angle distributions during storms and substorms

NASA Technical Reports Server (NTRS)

Sibeck, D. G.; Mcentire, R. W.; Lui, A. T. Y.; Lopez, R. E.; Krimigis, S. M.

1987-01-01

This paper presents a magnetic field drift shell-splitting model for the unusual butterfly and head-and-shoulder energetic (E greater than 25 keV) particle pitch angle distributions (PADs) which appear deep within the dayside magnetosphere during the course of storms and substorms. Drift shell splitting separates the high and low pitch angle particles in nightside injections as they move to the dayside magnetosphere, so that the higher pitch angle particles move radially away from earth. Consequently, butterfly PADs with a surplus of low pitch angle particles form on the inner edge of the injection, but head-and-shoulder PADs with a surplus of high pitch angle particles form on the outer edge. A similar process removes high pitch angle particles from the inner dayside magnetosphere during storms, leaving the remaining lower pitch angle particles to form butterfly PADs on the inner edge of the ring current. A detailed case and statistical study of Charge Composition Explorer/Medium-energy Particle Analyzer observations, as well as a review of previous work, shows most examples of unusual PADs to be consistent with the model.

Ruptured profunda femoris aneurysm secondary to neurofibromatosis: vascular involvement in an unusual location.

PubMed

Emrecan, Bilgin; Onem, Gokhan; Susam, Ibrahim

2010-01-01

Neurofibromatosis is an autosomal dominant genetic disease characterized by abnormal growth that involves tissues of mesodermal and neuroectodermal origin. Aneurysms are rarely seen in peripheral arteries. This report presents a case of ruptured arterial aneurysm secondary to neurofibromatosis; the lesion occurred in the profunda femoris artery, a highly unusual location. Treatment of patients with ruptured arterial aneurysm secondary to neurofibromatosis may be interventional or surgical. In this case, a surgical approach was successful.

Unusual developmental pattern of brain lateralization in young boys with autism spectrum disorder: Power analysis with child-sized magnetoencephalography.

PubMed

Hiraishi, Hirotoshi; Kikuchi, Mitsuru; Yoshimura, Yuko; Kitagawa, Sachiko; Hasegawa, Chiaki; Munesue, Toshio; Takesaki, Natsumi; Ono, Yasuki; Takahashi, Tsutomu; Suzuki, Michio; Higashida, Haruhiro; Asada, Minoru; Minabe, Yoshio

2015-03-01

Autism spectrum disorder (ASD) is often described as comprising an unusual brain growth pattern and aberrant brain lateralization. Although it is important to study the pathophysiology of the developing ASD cortex, examples of physiological brain lateralization in young children with ASD have yet to be well examined. Thirty-eight boys with ASD (aged 3-7 years) and 38 typically developing (TD) boys (aged 3-8 years) concentrated on video programs and their brain activities were measured non-invasively. We employed a customized child-sized magnetoencephalography system in which the sensors were located as close to the brain as possible for optimal recording in young children. To produce a credible laterality index of the brain oscillations, we defined two clusters of sensors corresponding to the right and left hemispheres. We focused on the laterality index ([left - right]/[left+right]) of the relative power band in seven frequency bands. The TD group displayed significantly rightward lateralized brain oscillations in the theta-1 frequency bands compared to the ASD group. This is the first study to demonstrate unusual brain lateralization of brain oscillations measured by magnetoencephalography in young children with ASD. © 2014 The Authors. Psychiatry and Clinical Neurosciences © 2014 Japanese Society of Psychiatry and Neurology.

High Laccase Expression by Trametes versicolor in a Simulated Textile Effluent with Different Carbon Sources and PHs.

PubMed

Ottoni, Cristiane; Simões, Marta F; Fernandes, Sara; Santos, Cledir R; Lima, Nelson

2016-08-02

Textile effluents are highly polluting and have variable and complex compositions. They can be extremely complex, with high salt concentrations and alkaline pHs. A fixed-bed bioreactor was used in the present study to simulate a textile effluent treatment, where the white-rot fungus, Trametes versicolor, efficiently decolourised the azo dye Reactive Black 5 over 28 days. This occurred under high alkaline conditions, which is unusual, but advantageous, for successful decolourisation processes. Active dye decolourisation was maintained by operation in continuous culture. Colour was eliminated during the course of operation and maximum laccase (Lcc) activity (80.2 U∙L(-1)) was detected after glycerol addition to the bioreactor. Lcc2 gene expression was evaluated with different carbon sources and pH values based on reverse transcriptase-PCR (polymerase chain reaction). Glycerol was shown to promote the highest lcc2 expression at pH 5.5, followed by sucrose and then glucose. The highest levels of expression occurred between three and four days, which corroborate the maximum Lcc activity observed for sucrose and glycerol on the bioreactor. These results give new insights into the use of T. versicolor in textile dye wastewater treatment with high pHs.

Hyperglycemia and Diabetic Ketoacidosis

MedlinePlus

... your child's age. Causes of High Blood Sugar Levels A major goal in controlling diabetes is to ... be unusually tired. Checking for High Blood Sugar Levels As part of the diabetes management plan, you' ...

Enzymatic production of dietary nucleotides from low-soluble purine bases by an efficient, thermostable and alkali-tolerant biocatalyst.

PubMed

Del Arco, J; Cejudo-Sanches, J; Esteban, I; Clemente-Suárez, V J; Hormigo, D; Perona, A; Fernández-Lucas, J

2017-12-15

Traditionally, enzymatic synthesis of nucleoside-5'-monophosphates (5'-NMPs) using low water-soluble purine bases has been described as less efficient due to their low solubility in aqueous media. The use of enzymes from extremophiles, such as thermophiles or alkaliphiles, offers the potential to increase solubilisation of these bases by employing high temperatures or alkaline pH. This study describes the cloning, expression and purification of hypoxanthine-guanine-xanthine phosphoribosyltransferase from Thermus thermophilus (TtHGXPRT). Biochemical characterization indicates TtHGXPRT as a homotetramer with excellent activity and stability across a broad range of temperatures (50-90°C) and ionic strengths (0-500mMNaCl), but it also reveals an unusually high activity and stability under alkaline conditions (pH range 8-11). In order to explore the potential of TtHGXPRT as an industrial biocatalyst, enzymatic production of several dietary 5'-NMPs, such as 5'-GMP and 5'-IMP, was carried out at high concentrations of guanine and hypoxanthine. Copyright © 2017 Elsevier Ltd. All rights reserved.

Isolation and characterization of a novel 2-methyl-4-chlorophenoxyacetic acid-degrading Enterobacter sp. strain SE08.

PubMed

Tan, Lin; Hu, Qiulong; Xiong, Xingyao; Su, Xiaojun; Huang, Yanning; Jiang, Ziwei; Zhou, Qingming; Zhao, Songyi; Zeng, Wei-ai

2013-10-01

A bacterial strain (SE08) capable of utilizing 2-methyl-4-chlorophenoxy acetic acid (MCPA) as the sole carbon and energy source for growth was isolated by continuous enrichment culturing in minimal salt medium (MSM) from a long term MCPA exposed soil. This bacterial strain was identified as Enterobacter sp. based on morphological, physiological and biochemical tests, as well as 16S rRNA sequence analysis. Its ability to degrade MCPA was determined using high performance liquid chromatography. The strain SE08 can tolerate unusually high MCPA concentrations (125-2000mg/L). The influences of culturing factors (initial concentration, pH, and temperature) on the bacterial growth and substrate degradation were studied. The results showed that the optimal MCPA degradation occurred at an MCPA concentration of 500mg/L, 30°C and pH 6.0. Under these conditions, 68.5 percent of MCPA in MSM was degraded by SE08, and the OD600nm reached 0.64 after culturing for 72h. The degradation of MCPA could be enhanced by addition of both carbon and nitrogen sources. At an initial MCPA concentration of 500mg/L, when 5g/L glucose and 2.5g/L yeast extract were added into the MSM media, the MCPA degradation was significantly increased to 83.8 percent, and OD600nm was increased to 1.09 after incubation at 30°C and pH 6.0 for 72h. This is the first study showing that an Enterobacter sp. strain is capable of degrading MCPA, which might provide a new approach for the remediation of MCPA contaminated soil and contribute to the limited knowledge about the function of Enterobacter species. Crown Copyright © 2013. Published by Elsevier Inc. All rights reserved.

Enhanced Primary Production, and Altered Biogeochemical Patterns in the German Bight in Response to the Extreme June 2013 Elbe Flood

NASA Astrophysics Data System (ADS)

Voynova, Y. G.; Petersen, W.; Brix, H.

2016-02-01

Due to a number of well documented and unusual atmospheric conditions, the late-spring of 2013 in Central and Eastern Europe was colder and wetter than usual, with saturated soils and higher than average cumulative precipitation. Additional precipitation at the end of May, and beginning of June 2013, caused widespread floods within the Danube and Elbe Rivers, and billions of euros in damages. Within the Elbe watershed, the discharge generated under these conditions was the largest among all summer floods and the second largest on record over the last 140 years (based on daily discharges). The high-frequency monitoring network of the Coastal Observing System for Northern and Arctic Seas (COSYNA) captured the influence of this major freshwater influx on the German Bight. Data from an Elbe Estuary (Cuxhaven) monitoring station, and from a FerryBox aboard a ferry travelling between Büsum and Helgoland, documented the salinity changes in the German Bight, which persisted for a month after the peak river discharge. The flood generated a large influx of dissolved and particulate organic carbon, associated with the freshwater plume, while surface dissolved oxygen between Büsum and Helgoland became undersaturated (not typical for the summer). The Federal Maritime and Hydrographic Agency (BSH) also reported unusually high nutrient concentrations in the German Bight caused by the flood. These conditions subsequently generated a month-long chlorophyll bloom, prolonged dissolved oxygen supersaturation, and higher than usual surface water pH within the German Bight. In the context of predicted increase in frequency of extreme discharge events due to climate change, the June 2013 flood-related biogeochemical changes could become more ubiquitous in the future, and should be considered in management and modeling efforts.

7 CFR 3201.41 - Metalworking fluids.

Code of Federal Regulations, 2013 CFR

2013-01-01

... feedstock during grinding and machining operations involving unusually high temperatures or corrosion... prevention when applied to metal feedstock during normal grinding and machining operations. (iii) High... percent. (3) High performance soluble, semi-synthetic, and synthetic oils—40 percent. (c) Preference...

7 CFR 3201.41 - Metalworking fluids.

Code of Federal Regulations, 2012 CFR

2012-01-01

... feedstock during grinding and machining operations involving unusually high temperatures or corrosion... prevention when applied to metal feedstock during normal grinding and machining operations. (iii) High... percent. (3) High performance soluble, semi-synthetic, and synthetic oils—40 percent. (c) Preference...

7 CFR 3201.41 - Metalworking fluids.

Code of Federal Regulations, 2014 CFR

2014-01-01

... feedstock during grinding and machining operations involving unusually high temperatures or corrosion... prevention when applied to metal feedstock during normal grinding and machining operations. (iii) High... percent. (3) High performance soluble, semi-synthetic, and synthetic oils—40 percent. (c) Preference...

Sensitivities of winter ozone pollution events in oil and gas producing regions to VOCs, NOx and radicals (Invited)

NASA Astrophysics Data System (ADS)

Edwards, P. M.; Aikin, K.; De Gouw, J. A.; Dube, W. P.; Geiger, F.; Gilman, J.; Helmig, D.; Holloway, J.; Kercher, J. P.; Koss, A.; Lerner, B. M.; Martin, R. S.; McLaren, R.; Min, K.; Parrish, D. D.; Peischl, J.; Roberts, J. M.; Ryerson, T. B.; Thornton, J. A.; Veres, P. R.; Warneke, C.; Wild, R. J.; Williams, E. J.; Young, C.; Yuan, B.; Brown, S. S.

2013-12-01

The Uintah Basin in northeastern Utah, a region of intense oil and gas extraction, experienced ozone (O3) mixing ratios well above limits set by air quality standards for multiple days during three of the last four winters. The Uintah Basin Winter Ozone Study (UBWOS) consisted of two field intensives, in early 2012 and 2013, with the goal of addressing current uncertainties in the chemical and physical processes that drive wintertime O3 production in regions of oil and gas development. The data from these two study periods provide an excellent comparison of high and low O3 production years, as meteorological conditions during the winter of 2011-2012 resulted in no elevated O3 mixing ratios, in contrast to the winter of 2012-2013 when observed O3 mixing ratios were the highest yet recorded in the Uintah Basin. Box modeling studies, using the Master Chemical Mechanism (MCM v3.2) chemistry scheme, have been used to investigate our understanding of O3 photochemistry in this unusual emissions environment. Simulations identify O3 production in 2012 to be highly radical limited, with less conventional radical sources, such as HCHO, HONO, and ClNO2 photolysis, playing a central role. Consequently, O3 production during 2012 was highly VOC sensitive, despite the much larger mixing ratio of total non-methane hydrocarbons relative to NO¬x. Conditions during UBWOS 2013 resulted in significantly higher O3 precursor species concentrations than during 2012, including the concentrations of the radical precursors HCHO and HONO. Simulations constrained to the 2013 data show the effects of these changes in pre-cursor concentrations on the radical budget, and thus on local O3 photochemistry and its sensitivities during a wintertime O3 pollution episode.

[Rhabdomyolysis in a well-trained woman after unusually intense exercise].

PubMed

Larsen, Christian; Jensen, Mogens Pfeiffer

2014-06-16

A 35-year-old woman was acutely hospitalized with oedema of the upper limbs, reduced force, severe movement reduction and muscle pain in both upper extremities. Her symptoms started after three days of intense exercise doing kayaking and a lot of pull-ups in crossfit. Rhabdomyolysis is a syndrome, characterized by muscle necrosis. Usually there is a marked elevation of creatine kinase (CK) concentration with symptoms as described and myoglobinuria (dark coloured urine). After hard muscular work there will often be asymptomatic, but significant elevations in CK concentration, and in rare cases life-threatening rhabdomyolysis with electrolyte imbalances and acute kidney failure.

High blood oxygen affinity in the air-breathing swamp eel Monopterus albus.

PubMed

Damsgaard, Christian; Findorf, Inge; Helbo, Signe; Kocagoz, Yigit; Buchanan, Rasmus; Huong, Do Thi Thanh; Weber, Roy E; Fago, Angela; Bayley, Mark; Wang, Tobias

2014-12-01

The Asian swamp eel (Monopterus albus, Zuiew 1793) is a facultative air-breathing fish with reduced gills. Previous studies have shown that gas exchange seems to occur across the epithelium of the buccopharyngeal cavity, the esophagus and the integument, resulting in substantial diffusion limitations that must be compensated by adaptations in others steps of the O₂ transport system to secure adequate O₂ delivery to the respiring tissues. We therefore investigated O₂ binding properties of whole blood, stripped hemoglobin (Hb), two major isoHb components and the myoglobin (Mb) from M. albus. Whole blood was sampled using indwelling catheters for blood gas analysis and determination of O₂ equilibrium curves. Hb was purified to assess the effects of endogenous allosteric effectors, and Mb was isolated from heart and skeletal muscle to determine its O₂ binding properties. The blood of M. albus has a high O₂ carrying capacity [hematocrit (Hct) of 42.4±4.5%] and binds O₂ with an unusually high affinity (P₅₀=2.8±0.4mmHg at 27°C and pH7.7), correlating with insensitivity of the Hb to the anionic allosteric effectors that normally decrease Hb-O₂ affinity. In addition, Mb is present at high concentrations in both heart and muscle (5.16±0.99 and 1.08±0.19mg ∙ g wet tissue⁻¹, respectively). We suggest that the high Hct and high blood O₂ affinity serve to overcome the low diffusion capacity in the relatively inefficient respiratory surfaces, while high Hct and Mb concentration aid in increasing the O₂ flux from the blood to the muscles. Copyright © 2014 Elsevier Inc. All rights reserved.

A Diverticular ‘Pain in the Bottom’

PubMed Central

Bardhan, Suchi K; Morgan, Emma; Daniels, Ian R; Mortensen, Neil J

2006-01-01

This is the case of a 40-year-old man with a gluteal abscess as the first presentation of diverticular disease. As well as the unusual site, imaging revealed the lack of a connective tract between the abscess and the abdominal cavity or retroperitoneum. In addition, a lack of gastrointestinal symptoms made this case very unusual. Hence, this highlights the need for a high index of clinical suspicion when the usual clinical pointers that guide to the diagnosis of diverticulitis are absent. PMID:16834842

A diverticular 'pain in the bottom'.

PubMed

Bardhan, Suchi K; Morgan, Emma; Daniels, Ian R; Mortensen, Neil J

2006-07-01

This is the case of a 40-year-old man with a gluteal abscess as the first presentation of diverticular disease. As well as the unusual site, imaging revealed the lack of a connective tract between the abscess and the abdominal cavity or retroperitoneum. In addition, a lack of gastrointestinal symptoms made this case very unusual. Hence, this highlights the need for a high index of clinical suspicion when the usual clinical pointers that guide to the diagnosis of diverticulitis are absent.

Rare Orbital Infections ~ State of the Art ~ Part II

PubMed Central

Hamed-Azzam, Shirin; AlHashash, Islam; Briscoe, Daniel; Rose, Geoffrey E; Verity, David H.

2018-01-01

Infections of the orbit and periorbita are relatively frequent. Identifying unusual organisms is crucial because they can cause severe local and systemic morbidity, despite their rarity. Opportunistic infections of the orbit should be considered mainly in debilitated or immunocompromised patients. The key to successful management includes a high index of suspicion, prompt diagnosis, and addressing the underlying systemic disease. This review summarizes unusual infectious processes of the orbit, including mycobacterial, fungal, and parasitic infections, as well as their pathophysiology, symptoms, signs, and treatment. PMID:29719648

Queensland tick typhus: three cases with unusual clinical features.

PubMed

Wilson, P A; Tierney, L; Lai, K; Graves, S

2013-07-01

Queensland tick typhus (QTT), caused by Rickettsia australis, is usually a relatively mild illness but can occasionally be severe. We describe three cases of probable QTT with unusual clinical features, namely splenic infarction, fulminant myopericarditis and severe leukocytoclastic vasculitis. QTT may present with uncommon clinical features in addition to the more common manifestations. A high index of suspicion enables specific antibiotic therapy that may hasten recovery. © 2013 The Authors; Internal Medicine Journal © 2013 Royal Australasian College of Physicians.

EDTA-assisted Pb phytoextraction.

PubMed

Saifullah; Meers, E; Qadir, M; de Caritat, P; Tack, F M G; Du Laing, G; Zia, M H

2009-03-01

Pb is one of the most widespread and metal pollutants in soil. It is generally concentrated in surface layers with only a minor portion of the total metal found in soil solution. Phytoextraction has been proposed as an inexpensive, sustainable, in situ plant-based technology that makes use of natural hyperaccumulators as well as high biomass producing crops to help rehabilitate soils contaminated with heavy metals without destructive effects on soil properties. The success of phytoextraction is determined by the amount of biomass, concentration of heavy metals in plant, and bioavailable fraction of heavy metals in the rooting medium. In general, metal hyperaccumulators are low biomass, slow growing plant species that are highly metal specific. For some metals such as Pb, there are no hyperaccumulator plant species known to date. Although high biomass-yielding non-hyperaccumulator plants lack an inherent ability to accumulate unusual concentrations of Pb, soil application of chelating agents such as EDTA has been proposed to enhance the metal concentration in above-ground harvestable plant parts through enhancing the metal solubility and translocation from roots to shoots. Leaching of metals due to enhanced mobility during EDTA-assisted phytoextraction has been demonstrated as one of the potential hazards associated with this technology. Due to environmental persistence of EDTA in combination with its strong chelating abilities, the scientific community is moving away from the use of EDTA in phytoextraction and is turning to less aggressive alternative strategies such as the use of organic acids or more degradable APCAs (aminopolycarboxylic acids). We have therefore arrived at a point in phytoremediation research history in which we need to distance ourselves from EDTA as a proposed soil amendment within the context of phytoextraction. However, valuable lessons are to be learned from over a decade of EDTA-assisted phytoremediation research when considering the implementation of more degradable alternatives in assisted phytoextraction practices.

Skeletal muscle as an endogenous nitrate reservoir

PubMed Central

Piknova, Barbora; Park, Ji Won; Swanson, Kathryn M.; Dey, Soumyadeep; Noguchi, Constance Tom; Schechter, Alan N

2015-01-01

The nitric oxide synthase (NOS) family of enzymes form nitric oxide (NO) from arginine in the presence of oxygen. At reduced oxygen availability NO is also generated from nitrate in a two step process by bacterial and mammalian molybdopterin proteins, and also directly from nitrite by a variety of five-coordinated ferrous hemoproteins. The mammalian NO cycle also involves direct oxidation of NO to nitrite, and both NO and nitrite to nitrate by oxy-ferrous hemoproteins. The liver and blood are considered the sites of active mammalian NO metabolism and nitrite and nitrate concentrations in the liver and blood of several mammalian species, including human, have been determined. However, the large tissue mass of skeletal muscle had not been generally considered in the analysis of the NO cycle, in spite of its long-known presence of significant levels of active neuronal NOS (nNOS or NOS1). We hypothesized that skeletal muscle participates in the NO cycle and, due to its NO oxidizing heme protein, oxymyoglobin, has high concentrations of nitrate ions. We measured nitrite and nitrate concentrations in rat and mouse leg skeletal muscle and found unusually high concentrations of nitrate but similar levels of nitrite, when compared to the liver. The nitrate reservoir in muscle is easily accessible via the bloodstream and therefore nitrate is available for transport to internal organs where it can be reduced to nitrite and NO. Nitrate levels in skeletal muscle and blood in nNOS−/− mice were dramatically lower when compared with controls, which support further our hypothesis. Although the nitrate reductase activity of xanthine oxidoreductase in muscle is less than that of liver, the residual activity in muscle could be very important in view of its total mass and the high basal level of nitrate. We suggest that skeletal muscle participates in overall NO metabolism, serving as a nitrate reservoir, for direct formation of nitrite and NO, and for determining levels of nitrate in other organs. PMID:25727730

Unusual transformation from strong negative to positive thermal expansion in PbTiO3-BiFeO3 perovskite.

PubMed

Chen, Jun; Fan, Longlong; Ren, Yang; Pan, Zhao; Deng, Jinxia; Yu, Ranbo; Xing, Xianran

2013-03-15

Tetragonal PbTiO(3)-BiFeO(3) exhibits a strong negative thermal expansion in the PbTiO(3)-based ferroelectrics that consist of one branch in the family of negative thermal expansion materials. Its strong negative thermal expansion is much weakened, and then unusually transforms into positive thermal expansion as the particle size is slightly reduced. This transformation is a new phenomenon in the negative termal expansion materials. The detailed structure, temperature dependence of unit cell volume, and lattice dynamics of PbTiO(3)-BiFeO(3) samples were studied by means of high-energy synchrotron powder diffraction and Raman spectroscopy. Such unusual transformation from strong negative to positive thermal expansion is highly associated with ferroelectricity weakening. An interesting zero thermal expansion is achieved in a wide temperature range (30-500 °C) by adjusting particle size due to the negative-to-positive transformation character. The present study provides a useful method to control the negative thermal expansion not only for ferroelectrics but also for those functional materials such as magnetics and superconductors.

A Nonhuman Primate Model of Human Radiation-Induced Venocclusive Liver Disease and Hepatocyte Injury

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yannam, Govardhana Rao; Han, Bing; Department of Hepatobiliary Surgery, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi

Background: Human liver has an unusual sensitivity to radiation that limits its use in cancer therapy or in preconditioning for hepatocyte transplantation. Because the characteristic veno-occlusive lesions of radiation-induced liver disease do not occur in rodents, there has been no experimental model to investigate the limits of safe radiation therapy or explore the pathogenesis of hepatic veno-occlusive disease. Methods and Materials: We performed a dose-escalation study in a primate, the cynomolgus monkey, using hypofractionated stereotactic body radiotherapy in 13 animals. Results: At doses ≥40 Gy, animals developed a systemic syndrome resembling human radiation-induced liver disease, consisting of decreased albumin, elevatedmore » alkaline phosphatase, loss of appetite, ascites, and normal bilirubin. Higher radiation doses were lethal, causing severe disease that required euthanasia approximately 10 weeks after radiation. Even at lower doses in which radiation-induced liver disease was mild or nonexistent, latent and significant injury to hepatocytes was demonstrated by asialoglycoprotein-mediated functional imaging. These monkeys developed hepatic failure with encephalopathy when they received parenteral nutrition containing high concentrations of glucose. Histologically, livers showed central obstruction via an unusual intimal swelling that progressed to central fibrosis. Conclusions: The cynomolgus monkey, as the first animal model of human veno-occlusive radiation-induced liver disease, provides a resource for characterizing the early changes and pathogenesis of venocclusion, for establishing nonlethal therapeutic dosages, and for examining experimental therapies to minimize radiation injury.« less

Resolution of fine biological structure including small narcomedusae across a front in the Southern California Bight

NASA Astrophysics Data System (ADS)

McClatchie, Sam; Cowen, Robert; Nieto, Karen; Greer, Adam; Luo, Jessica Y.; Guigand, Cedric; Demer, David; Griffith, David; Rudnick, Daniel

2012-04-01

We sampled a front detected by SST gradient, ocean color imagery, and a Spray glider south of San Nicolas Island in the Southern California Bight between 14 and 18 October 2010. We sampled the front with an unusually extensive array of instrumentation, including the Continuous Underway Fish Egg Sampler (CUFES), the undulating In Situ Ichthyoplankton Imaging System (ISIIS) (fitted with temperature, salinity, oxygen, and fluorescence sensors), multifrequency acoustics, a surface pelagic trawl, a bongo net, and a neuston net. We found higher fluorescence and greater cladoceran, decapod, and euphausiid densities in the front, indicating increased primary and secondary production. Mesopelagic fish were most abundant in oceanic waters to the west of the front, market squid were abundant in the front associated with higher krill and decapod densities, and jack mackerel were most common in the front and on the shoreward side of the front. Egg densities peaked to either side of the front, consistent with both offshore (for oceanic squid and mesopelagic fish) and shelf origins (for white croaker and California halibut). We discovered unusually high concentrations of predatory narcomedusae in the surface layer of the frontal zone. Potential ichthyoplankton predators were more abundant either in the front (decapods, euphausiids, and squid) or shoreward of the front (medusae, chaetognaths, and jack mackerel). For pelagic fish like sardine, which can thrive in less productive waters, the safest place to spawn would be offshore because there are fewer potential predators.

Unusual diffusive effects on the ESR of Nd 3+ ions in the tunable topologically nontrivial semimetal YBiPt

DOE PAGES

Lesseux, G. G.; Garitezi, T. M.; Rosa, P. F. S.; ...

2016-02-24

Electron spin resonance (ESR) of diluted Nd 3+ ions in the topologically nontrivial semimetallic (TNSM) YBiPt compound is reported. The cubic YBiPt compound is a non-centrosymmetric half Heusler material which crystallizes in the F43m space group. The low temperature Nd 3+ ESR spectra showed a g-value of 2.66(4) corresponding to amore » $${{\\Gamma}_{6}}$$ cubic crystal field Kramers' doublet ground state. Remarkably, the observed metallic and diffusive (Dysonian) Nd 3+ lineshape presented an unusual dependence with grain size, microwave power, Nd 3+ concentration and temperature. Furthermore, the spin dynamic of the localized Nd 3+ ions in YBiPt was found to be characteristic of a phonon-bottleneck regime. It is claimed that, in this regime for YBiPt, phonons are responsible for mediating the diffusion of the microwave energy absorbed at resonance by the Nd 3+ ions to the thermal bath throughout the skin depth ($$\\delta \\simeq 15$$ μm). We argue that this is only possible because of the existence of highly mobile conduction electrons inside the skin depth of YBiPt that are strongly coupled to the phonons by spin–orbit coupling. Thus, our unexpected ESR results point to a coexistence of metallic and insulating behaviors within the skin depth of YBiPt. This scenario is discussed in the light of the TNSM properties of this compound.« less

Enhanced Magnetization of Cobalt Defect Clusters Embedded in TiO2-δ Films.

PubMed

Cortie, David L; Khaydukov, Yury; Keller, Thomas; Sprouster, David J; Hughes, Jacob S; Sullivan, James P; Wang, Xiaolin L; Le Brun, Anton P; Bertinshaw, Joel; Callori, Sara J; Aughterson, Robert; James, Michael; Evans, Peter J; Triani, Gerry; Klose, Frank

2017-03-15

High magnetizations are desirable for spintronic devices that operate by manipulating electronic states using built-in magnetic fields. However, the magnetic moment in promising dilute magnetic oxide nanocomposites is very low, typically corresponding to only fractions of a Bohr magneton for each dopant atom. In this study, we report a large magnetization formed by ion implantation of Co into amorphous TiO 2-δ films, producing an inhomogeneous magnetic moment, with certain regions producing over 2.5 μ B per Co, depending on the local dopant concentration. Polarized neutron reflectometry was used to depth-profile the magnetization in the Co:TiO 2-δ nanocomposites, thus confirming the pivotal role of the cobalt dopant profile inside the titania layer. X-ray photoemission spectra demonstrate the dominant electronic state of the implanted species is Co 0 , with a minor fraction of Co 2+ . The detected magnetizations have seldom been reported before and lie near the upper limit set by Hund's rules for Co 0 , which is unusual because the transition metal's magnetic moment is usually reduced in a symmetric 3D crystal-field environment. Low-energy positron annihilation lifetime spectroscopy indicates that defect structures within the titania layer are strongly modified by the implanted Co. We propose that a clustering motif is promoted by the affinity of the positively charged implanted species to occupy microvoids native to the amorphous host. This provides a seed for subsequent doping and nucleation of nanoclusters within an unusual local environment.

An Intense Polarized Radio Flare from AR Lac

NASA Astrophysics Data System (ADS)

Mutel, R. L.; Neff, J. E.; Bookbinder, J.; Pagano, I.

1992-12-01

We have detected an intense, highly circularly polarized radio flare from the close binary system AR Lacertae during a 4 day multi-wavelength observing campaign in 1991 December. The flare lasted more than 6 hours and was preceded by a strong CIV flare one day earlier. The peak circular polarization was 70%, 38%,and 39% RCP at 1.4, 4.9, and 8.4 GHz respectively, with ~ 15% LCP at 15 and 22 GHZ. The high degree of circular polarization over such a large time scale and frequency range is highly unusual compared with previously observed radio flares from RS CVn binaries. Given these unusual characteristics, it is difficult to interpret the radiation mechanism either as a result of gyrosynchrotron emission or a coherent process such as an electron cyclotron maser.

Synthesis of sodium polyhydrides at high pressures

NASA Astrophysics Data System (ADS)

Struzhkin, Viktor V.; Kim, Duck Young; Stavrou, Elissaios; Muramatsu, Takaki; Mao, Ho-Kwang; Pickard, Chris J.; Needs, Richard J.; Prakapenka, Vitali B.; Goncharov, Alexander F.

2016-07-01

The only known compound of sodium and hydrogen is archetypal ionic NaH. Application of high pressure is known to promote states with higher atomic coordination, but extensive searches for polyhydrides with unusual stoichiometry have had only limited success in spite of several theoretical predictions. Here we report the first observation of the formation of polyhydrides of Na (NaH3 and NaH7) above 40 GPa and 2,000 K. We combine synchrotron X-ray diffraction and Raman spectroscopy in a laser-heated diamond anvil cell and theoretical random structure searching, which both agree on the stable structures and compositions. Our results support the formation of multicenter bonding in a material with unusual stoichiometry. These results are applicable to the design of new energetic solids and high-temperature superconductors based on hydrogen-rich materials.

Preliminary paleomagnetic and rock magnetic results from 17 to 22 ka sediment of Jeju Island, Korea: Geomagnetic excursional behavior or rock magnetic anomalies?

NASA Astrophysics Data System (ADS)

Ahn, Hyeon-Seon; Sohn, Young Kwan; Lee, Jin-Young; Kim, Jin Cheul

2018-05-01

Paleomagnetic and rock magnetic investigations were performed on a 64-cm-thick section of nonmarine unconsolidated muddy sediment from the Gosan Formation on Jeju Island, Korea. This sediment was recently dated to have been deposited between 22 and 17 kyr BP calibrated, with a sedimentation rate of 13-25 cm/kyr, based on many radiocarbon ages. Interestingly, stepwise alternating field (AF) demagnetization revealed characteristic natural remanent magnetizations with anomalous directions, manifested by marked deviations from the direction of today's axial dipole field, for some separate depth levels. On the other hand, stepwise thermal (TH) demagnetization showed more complex behavior, resulting in the identification of multiple remanence components. For all TH-treated specimens, consistently two different components are predominant: a low-temperature component unblocked below 240-320 °C entirely having normal-polarity apparently within the secular variation range of the Brunhes Chron, and a high-temperature component with unblocking temperatures (Tubs) between 240-320 and 520-580 °C that have anomalous directions, concentrated in the 13-34-cm-depth interval ( 17-19 ka in inferred age) and possibly below 53 cm depth (before 20 ka). Rock magnetic results also infer the dominance of low-coercivity magnetic particles having 300 and 580 °C Curie temperature as remanence carriers, suggestive of (titano)maghemite and/or Ti-rich titanomagnetite and magnetite (or Ti-poor titanomagnetite), respectively. A noteworthy finding is that AF demagnetizations in this study often lead to incomplete separation of the two remanence components possibly due to their strongly overlapping AF spectra. The unusual directions do not appear to result from self-reversal remanences. Then, one interpretation is that the low-temperature components are attributable to post-depositional chemical remanences, associated possibly with the later formation of the mineral phase having Tub 300 °C, whereas the high-temperature components are of primary detrital origin that survived later chemical influence. Accordingly, the unusual directions might record geomagnetic instability within the 17-22 ka period manifested by multiple excursional swings, partly associated with the Tianchi/Hilina Pali excursion. However, further work is needed to verify this interpretation and distinguish it from alternative explanations that invoke rock magnetic complexities as the cause of the unusual directions.[Figure not available: see fulltext.

An Award Winning Design for Downtown Manhattan High School

ERIC Educational Resources Information Center

Modern Schools, 1974

1974-01-01

New York City's downtown Commercial High School will be completely air conditioned with an unusual all-air, variable air volume system that will keep students and teachers comfortable throughout the year. (Author/MF)

The remarkably high excitation planetary nebula GC 6537

PubMed Central

Aller, Lawrence H.; Hung, Siek; Feibelman, Walter A.

1999-01-01

NGC 6537 is an unusually high excitation point symmetric planetary nebula with a rich spectrum. Its kinematical structures are of special interest. We are here primarily concerned with the high resolution spectrum as revealed by the Hamilton echelle Spectrograph at Lick Observatory (resolution ≈ 0.2 Å) and supplemented by UV and near-UV data. These extensive data permit a determination of interstellar extinction, plasma diagnostics, and ionic concentrations. The photoionization models that have been used successfully for many planetary nebulae are not entirely satisfactory here. The plasma electron temperature of a photoionization model cannot much exceed 20,000 K, but plasma diagnostics show that regions emitting radiation of highly ionized atoms such as [Neiv] and [Nev] are much hotter, showing that shock excitation must be important, as suggested by the remarkable kinematics of this object. Hence, instead of employing a strict photoionization model, we are guided by the nebular diagnostics, which reveal how electron temperature varies with ionization potential and accommodates density effects. The predictions of the photoionization model may be useful in estimating ionization correction factor. In effect, we have estimated the chemical composition by using both photoionization and shock considerations. PMID:10318889

Highly Viscoelastic Reverse Wormlike Micellar Systems from a Mixture of Lecithin, Polyglycerol Fatty Acid Monoesters, and an Oil.

PubMed

Hashizaki, Kaname; Imai, Miko; Yako, Shuhei; Tsusaka, Hitomi; Sakanishi, Yuichi; Saito, Yoshihiro; Fujii, Makiko

2017-09-01

We report new lecithin reverse wormlike micelles with high viscoelasticity formed using lecithin/polyglycerol fatty acid monoester (PGLFA)/oil systems. In this study, the influence of the amphiphilicity (i.e., hydrophile-lipophile balance, HLB) of PGLFA on the phase behavior and rheological properties of reverse wormlike micelles was investigated in detail. PGLFAs with degrees of polymerization of polyglycerol varying between 6-40 and constituent fatty acids with chains between 6-18 carbon atoms long were used. Partial phase diagrams of the lecithin/PGLFA/n-decane systems indicated that the appropriate PGLFA could change the lecithin/oil solution into a highly viscoelastic solution comprising reverse wormlike micelles. Rheological measurements showed that all systems that formed reverse wormlike micelles exhibited an unusual phenomenon called "shear-thickening". Furthermore, reverse wormlike micelles grew as the PGLFA concentration increased and the zero-shear viscosity (η 0 ) of the solution rapidly increased. Our results indicate that the magnitude of the maximum η 0 depends on the degree of polymerization of the constituent polyglycerol in the PGLFA, while the size of the reverse micellar region and the highly viscous region in the phase diagram depends on the HLB value of the PGLFA.

Self-optimizing, highly surface-active layered metal dichalcogenide catalysts for hydrogen evolution

NASA Astrophysics Data System (ADS)

Liu, Yuanyue; Wu, Jingjie; Hackenberg, Ken P.; Zhang, Jing; Wang, Y. Morris; Yang, Yingchao; Keyshar, Kunttal; Gu, Jing; Ogitsu, Tadashi; Vajtai, Robert; Lou, Jun; Ajayan, Pulickel M.; Wood, Brandon C.; Yakobson, Boris I.

2017-09-01

Low-cost, layered transition-metal dichalcogenides (MX2) based on molybdenum and tungsten have attracted substantial interest as alternative catalysts for the hydrogen evolution reaction (HER). These materials have high intrinsic per-site HER activity; however, a significant challenge is the limited density of active sites, which are concentrated at the layer edges. Here we unravel electronic factors underlying catalytic activity on MX2 surfaces, and leverage the understanding to report group-5 MX2 (H-TaS2 and H-NbS2) electrocatalysts whose performance instead mainly derives from highly active basal-plane sites, as suggested by our first-principles calculations and performance comparisons with edge-active counterparts. Beyond high catalytic activity, they are found to exhibit an unusual ability to optimize their morphology for enhanced charge transfer and accessibility of active sites as the HER proceeds, offering a practical advantage for scalable processing. The catalysts reach 10 mA cm-2 current density at an overpotential of ˜50-60 mV with a loading of 10-55 μg cm-2, surpassing other reported MX2 candidates without any performance-enhancing additives.

The remarkably high excitation planetary nebula GC 6537.

PubMed

Aller, L H; Hung, S; Feibelman, W A

1999-05-11

NGC 6537 is an unusually high excitation point symmetric planetary nebula with a rich spectrum. Its kinematical structures are of special interest. We are here primarily concerned with the high resolution spectrum as revealed by the Hamilton echelle Spectrograph at Lick Observatory (resolution approximately 0.2 A) and supplemented by UV and near-UV data. These extensive data permit a determination of interstellar extinction, plasma diagnostics, and ionic concentrations. The photoionization models that have been used successfully for many planetary nebulae are not entirely satisfactory here. The plasma electron temperature of a photoionization model cannot much exceed 20,000 K, but plasma diagnostics show that regions emitting radiation of highly ionized atoms such as [NeIV] and [NeV] are much hotter, showing that shock excitation must be important, as suggested by the remarkable kinematics of this object. Hence, instead of employing a strict photoionization model, we are guided by the nebular diagnostics, which reveal how electron temperature varies with ionization potential and accommodates density effects. The predictions of the photoionization model may be useful in estimating ionization correction factor. In effect, we have estimated the chemical composition by using both photoionization and shock considerations.

Biogeochemical characterization of an undisturbed highly acidic, metal-rich bryophyte habitat, east-central Alaska, U.S.A.

USGS Publications Warehouse

Gough, L.P.; Eppinger, R.G.; Briggs, P.H.; Giles, S.

2006-01-01

We report on the geochemistry of soil and bryophyte-laden sediment and on the biogeochemistry of willows growing in an undisturbed volcanogenic massive sulfide deposit in the Alaska Range ecoregion of east-central Alaska. We also describe an unusual bryophyte assemblage found growing in the acidic metal-rich waters that drain the area. Ferricrete-cemented silty alluvial sediments within seeps and streams are covered with the liverwort Gymnocolea inflata whereas the mosses Polytrichum commune and P. juniperinum inhabit the area adjacent to the water and within the splash zone. Both the liverwort-encrusted sediment and Polytrichum thalli have high concentrations of major and trace metal cations (e.g., Al, As, Cu, Fe, Hg, La, Mn, Pb, and Zn). Soils in the area do not reflect the geochemical signature of the mineral deposit and we postulate they are influenced by the chemistry of eolian sediments derived from outside the deposit area. The willow, Salix pulchra, growing mostly within and adjacent to the larger streams, has much higher concentrations of Al, As, Cd, Cr, Fe, La, Pb, and Zn when compared to the same species collected in non-mineralized areas of Alaska. The Cd levels are especially high and are shown to exceed, by an order of magnitude, levels demonstrated to be toxic to ptarmigan in Colorado. Willow, growing in this naturally occurring metal-rich Red Mountain alteration zone, may adversely affect the health of browsing animals. ?? 2006 Regents of the University of Colorado.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bozovic, I.; Wu, J.; He, X.

Over the course of three decades of intense study, apart from the exceptionally high critical temperature, many unusual properties of cuprates have been discovered, notably including resistivity linear in temperature, electronic Raman continuum and optical absorption extending throughout the infrared region, pseudogap, hour-glass spin excitation spectrum, etc. However, each of these features have been also observed in other materials, including some that are not even superconducting at all. Here, we describe an extensive experiment in which over 2,000 films of the La 2-xSr xCuO 4 have been synthesized and studied in detail over the course of the last twelve years.more » We argue here that, uniquely, in the cuprates an unusual superconducting state, that defies the standard BCS description, develops from an unusual metallic state, in which the rotational symmetry of the electron fluid is spontaneously broken.« less

Big Jump of Record Warm Global Mean Surface Temperature in 2014-2016 Related to Unusually Large Oceanic Heat Releases

NASA Astrophysics Data System (ADS)

Yin, Jianjun; Overpeck, Jonathan; Peyser, Cheryl; Stouffer, Ronald

2018-01-01

A 0.24°C jump of record warm global mean surface temperature (GMST) over the past three consecutive record-breaking years (2014-2016) was highly unusual and largely a consequence of an El Niño that released unusually large amounts of ocean heat from the subsurface layer of the northwestern tropical Pacific. This heat had built up since the 1990s mainly due to greenhouse-gas (GHG) forcing and possible remote oceanic effects. Model simulations and projections suggest that the fundamental cause, and robust predictor of large record-breaking events of GMST in the 21st century, is GHG forcing rather than internal climate variability alone. Such events will increase in frequency, magnitude, and duration, as well as impact, in the future unless GHG forcing is reduced.

'Snake River (SR)-type' volcanism at the Yellowstone hotspot track: Distinctive products from unusual, high-temperature silicic super-eruptions

USGS Publications Warehouse

Branney, M.J.; Bonnichsen, B.; Andrews, G.D.M.; Ellis, B.; Barry, T.L.; McCurry, M.

2008-01-01

A new category of large-scale volcanism, here termed Snake River (SR)-type volcanism, is defined with reference to a distinctive volcanic facies association displayed by Miocene rocks in the central Snake River Plain area of southern Idaho and northern Nevada, USA. The facies association contrasts with those typical of silicic volcanism elsewhere and records unusual, voluminous and particularly environmentally devastating styles of eruption that remain poorly understood. It includes: (1) large-volume, lithic-poor rhyolitic ignimbrites with scarce pumice lapilli; (2) extensive, parallel-laminated, medium to coarse-grained ashfall deposits with large cuspate shards, crystals and a paucity of pumice lapilli; many are fused to black vitrophyre; (3) unusually extensive, large-volume rhyolite lavas; (4) unusually intense welding, rheomorphism, and widespread development of lava-like facies in the ignimbrites; (5) extensive, fines-rich ash deposits with abundant ash aggregates (pellets and accretionary lapilli); (6) the ashfall layers and ignimbrites contain abundant clasts of dense obsidian and vitrophyre; (7) a bimodal association between the rhyolitic rocks and numerous, coalescing low-profile basalt lava shields; and (8) widespread evidence of emplacement in lacustrine-alluvial environments, as revealed by intercalated lake sediments, ignimbrite peperites, rhyolitic and basaltic hyaloclastites, basalt pillow-lava deltas, rhyolitic and basaltic phreatomagmatic tuffs, alluvial sands and palaeosols. Many rhyolitic eruptions were high mass-flux, large volume and explosive (VEI 6-8), and involved H2O-poor, low-??18O, metaluminous rhyolite magmas with unusually low viscosities, partly due to high magmatic temperatures (900-1,050??C). SR-type volcanism contrasts with silicic volcanism at many other volcanic fields, where the fall deposits are typically Plinian with pumice lapilli, the ignimbrites are low to medium grade (non-welded to eutaxitic) with abundant pumice lapilli or fiamme, and the rhyolite extrusions are small volume silicic domes and coule??es. SR-type volcanism seems to have occurred at numerous times in Earth history, because elements of the facies association occur within some other volcanic fields, including Trans-Pecos Texas, Etendeka-Paran, Lebombo, the English Lake District, the Proterozoic Keewanawan volcanics of Minnesota and the Yardea Dacite of Australia. ?? Springer-Verlag 2007.

Brassicaceae seed oil identified as illuminant in Nilotic shells from a first millennium AD Coptic church in Bawit, Egypt.

PubMed

Romanus, Kerlijne; Van Neer, Wim; Marinova, Elena; Verbeke, Kristin; Luypaerts, Anja; Accardo, Sabina; Hermans, Ive; Jacobs, Pierre; De Vos, Dirk; Waelkens, Marc

2008-01-01

Burned greasy deposits were found inside shells of the large Nile bivalve Chambardia rubens, excavated in an eight- to tenth- century AD church of the Coptic monastery of Bawit, Egypt, and supposedly used as oil lamps. The residues were subjected to a combination of chromatographic residue analysis techniques. The rather high concentrations of unsaturated fatty acids, as analysed by gas chromatography (GC) in the methylated extract, suggest the presence of a vegetal oil. Analysis of the stable carbon isotopes (delta 13C values) of the methyl esters also favoured plants over animals as the lipid source. In the search for biomarkers by GC coupled to mass spectrometry on a silylated extract, a range of diacids together with high concentrations of 13,14-dihydroxydocosanoate and 11,12-dihydroxyeicosanoate were found. These compounds are oxidation products of erucic acid and gondoic acid, which are abundantly present in seeds of Brassicaceae plants. Liquid chromatography coupled to mass spectrometry analysis showed low concentrations of unaltered triglycerides, but revealed sizeable amounts of triglycerides with at least one dihydroxylated acyl chain. The unusual preservation of dihydroxylated triglycerides and alpha,omega-dicarboxylic acids can be related to the dry preservation conditions. Analysis of the stereoisomers of the dihydroxylated fatty acids allows one to determine whether oxidation took place during burning of the fuel or afterwards. The results prove that the oil of rapeseed (Brassica napus L.) or radish (Raphanus sativus L.) was used as illuminant in early Islamic Egypt, and that not only ceramic lamps but also mollusk shells were used as fuel containers.

The Current Driven Kink Instability and its Relationship to Delta-Spot Active Regions

NASA Astrophysics Data System (ADS)

Linton, Mark George

The current driven kink instability may be the cause of both the unusual morphology of solar δ-spot active regions and the tendency of these regions to be significantly more flare active than most active regions. We investigate the current driven kink instability of flux tubes in the solar interior both with a linear stability analysis and with nonlinear MHD simulations. The linear analysis shows that there is a critical twist, which depends on the axial magnetic field profile, that a flux tube needs to become kink unstable. This critical twist decreases as the tube expands, so twisted flux tubes will become increasingly unstable as they rise through the convection zone. The nonlinear simulations show that a twisted tube excited by a single unstable kink mode will evolve to a helical equilibrium state. The emergence through the photosphere of such a kinked tube would create an active region which was tilted with respect to Hale's law and which would rotate as it evolved, as δ-spots are observed to do. We then find that, when excited by multiple unstable kink modes, highly twisted flux tubes develop concentrated kinks. These concentrated kinks would produce more of the observed characteristics of δ-spot active regions. They would create active regions which, in addition to emerging tilted and then rotating, would remain compact as they evolved, and develop strong shear along their magnetic neutral line. Finally, we find that a strong concentrated kink develops a current sheet at which the magnetic field reconnects, which may be the cause of the high flare activity of δ-spots.

A mineral separation procedure using hot Clerici solution

USGS Publications Warehouse

Rosenblum, Sam

1974-01-01

Careful boiling of Clerici solution in a Pyrex test tube in an oil bath is used to float minerals with densities up to 5.0 in order to obtain purified concentrates of monazite (density 5.1) for analysis. The "sink" and "float" fractions are trapped in solidified Clerici salts on rapid chilling, and the fractions are washed into separate filter papers with warm water. The hazardous nature of Clerici solution requires unusual care in handling.

Water quality of North Carolina streams

USGS Publications Warehouse

Harned, Douglas; Meyer, Dann

1983-01-01

Interpretation of water quality data collected by the U.S. Geological Survey and the North Carolina Department of Natural Resources and Community Development, for the Yadkin-Pee Dee River system, has identified water quality variations, characterized the current condition of the river in reference to water quality standards, estimated the degree of pollution caused by man, and evaluated long-term trends in concentrations of major dissolved constituents. Three stations, Yadkin River at Yadkin College (02116500), Rocky River near Norwood (02126000), and Pee Dee River near Rockingham (02129000) have been sampled over different periods of time beginning in 1906. Overall, the ambient water quality of the Yadkin-Pee Dee River system is satisfactory for most water uses. Iron and manganese concentrations are often above desirable levels, but they are not unusually high in comparison to other North Carolina streams. Lead concentrations also periodically rise above the recommended criterion for domestic water use. Mercury concentrations frequently exceed, and pH levels fall below, the recommended criteria for protection of aquatic life. Dissolved oxygen levels, while generally good, are lowest at the Pee Dee near Rockingham, due to the station 's location not far downstream from a lake. Suspended sediment is the most significant water quality problem of the Yadkin-Pee Dee River. The major cation in the river is sodium and the major anions are bicarbonate and carbonate. Eutrophication is currently a problem in the Yadkin-Pee Dee, particularly in High Rock Lake. An estimated nutrient and sediment balance of the system indicates that lakes along the Yadkin-Pee Dee River serve as a sink for sediment, ammonia, and phosphorus. Pollution makes up approximately 59% of the total dissolved solids load of the Yadkin River at Yadkin College, 43% for the Rocky River near Norwood, and 29% for the Pee Dee River near Rockingham. Statistically significant trends show a pattern of increasing concentration of most dissolved constituents over time, with a leveling off and decline in the middle to late 1970's.

Towards a Unified Understanding of Lithium Action in Basic Biology and its Significance for Applied Biology.

PubMed

Jakobsson, Eric; Argüello-Miranda, Orlando; Chiu, See-Wing; Fazal, Zeeshan; Kruczek, James; Nunez-Corrales, Santiago; Pandit, Sagar; Pritchet, Laura

2017-12-01

Lithium has literally been everywhere forever, since it is one of the three elements created in the Big Bang. Lithium concentration in rocks, soil, and fresh water is highly variable from place to place, and has varied widely in specific regions over evolutionary and geologic time. The biological effects of lithium are many and varied. Based on experiments in which animals are deprived of lithium, lithium is an essential nutrient. At the other extreme, at lithium ingestion sufficient to raise blood concentration significantly over 1 mM/, lithium is acutely toxic. There is no consensus regarding optimum levels of lithium intake for populations or individuals-with the single exception that lithium is a generally accepted first-line therapy for bipolar disorder, and specific dosage guidelines for sufferers of that condition are generally agreed on. Epidemiological evidence correlating various markers of social dysfunction and disease vs. lithium level in drinking water suggest benefits of moderately elevated lithium compared to average levels of lithium intake. In contrast to other biologically significant ions, lithium is unusual in not having its concentration in fluids of multicellular animals closely regulated. For hydrogen ions, sodium ions, potassium ions, calcium ions, chloride ions, and magnesium ions, blood and extracellular fluid concentrations are closely and necessarily regulated by systems of highly selective channels, and primary and secondary active transporters. Lithium, while having strong biological activity, is tolerated over body fluid concentrations ranging over many orders of magnitude. The lack of biological regulation of lithium appears due to lack of lithium-specific binding sites and selectivity filters. Rather lithium exerts its myriad physiological and biochemical effects by competing for macromolecular sites that are relatively specific for other cations, most especially for sodium and magnesium. This review will consider what is known about the nature of this competition and suggest using and extending this knowledge towards the goal of a unified understanding of lithium in biology and the application of that understanding in medicine and nutrition.

Vacancy–Vacancy Interaction Induced Oxygen Diffusivity Enhancement in Undoped Nonstoichiometric Ceria

DOE PAGES

Yuan, Fenglin; Zhang, Yanwen; Weber, William J.

2015-05-19

In this paper, molecular dynamics simulations and molecular static calculations have been used to systematically study oxygen vacancy transport in undoped nonstoichiometric ceria. A strong oxygen diffusivity enhancement appears in the vacancy concentration range of 2–4% over the temperature range from 1000 to 2000 K. An Arrhenius ion diffusion mechanism by vacancy hopping along the (100) direction is unambiguously identified, and an increasing trend of both the oxygen migration barrier and the prefactor with increasing vacancy concentration is observed. Within the framework of classical diffusion theory, a weak concentration dependence of the prefactor in oxygen vacancy migration is shown tomore » be crucial for explaining the unusual fast oxygen ion migration in the low concentration range and consequently the appearance of a maximum in oxygen diffusivity. Finally, a representative (100) direction interaction model is constructed to identify long-range vacancy–vacancy interaction as the structural origin of the positive correlation between oxygen migration barrier and vacancy concentration.« less

Physics of rare events: insights on Napoleon death

NASA Astrophysics Data System (ADS)

Fiorini, Ettore

2009-03-01

This unusual report tries to show that the high level of sophistication reached in the instrumentation in experiments on rare events can allow to investigate with unprecedented accuracy problems far from those of fundamental physics, but quite important in other fields of physics. The technique and the know-how on neutron activation developed to reduce the background due to spurious events in the CUORE detector to search for neutrinoless double beta decay has been applied to determine the arsenic contents in the hairs of Napoleon Bonaparte and of historical subjects of his time and to compare it with those of subjects living presently. This contents has been found to be about two orders of magnitude larger than the present ones. The As concentration in the hairs of the Emperor is large, but similar to those of the his contemporaries. In additions a comparison among fraction of one of his hairs allows to exclude a criminal act.

Ambient intelligence application based on environmental measurements performed with an assistant mobile robot.

PubMed

Martinez, Dani; Teixidó, Mercè; Font, Davinia; Moreno, Javier; Tresanchez, Marcel; Marco, Santiago; Palacín, Jordi

2014-03-27

This paper proposes the use of an autonomous assistant mobile robot in order to monitor the environmental conditions of a large indoor area and develop an ambient intelligence application. The mobile robot uses single high performance embedded sensors in order to collect and geo-reference environmental information such as ambient temperature, air velocity and orientation and gas concentration. The data collected with the assistant mobile robot is analyzed in order to detect unusual measurements or discrepancies and develop focused corrective ambient actions. This paper shows an example of the measurements performed in a research facility which have enabled the detection and location of an uncomfortable temperature profile inside an office of the research facility. The ambient intelligent application has been developed by performing some localized ambient measurements that have been analyzed in order to propose some ambient actuations to correct the uncomfortable temperature profile.

Ambient Intelligence Application Based on Environmental Measurements Performed with an Assistant Mobile Robot

PubMed Central

Martinez, Dani; Teixidó, Mercè; Font, Davinia; Moreno, Javier; Tresanchez, Marcel; Marco, Santiago; Palacín, Jordi

2014-01-01

This paper proposes the use of an autonomous assistant mobile robot in order to monitor the environmental conditions of a large indoor area and develop an ambient intelligence application. The mobile robot uses single high performance embedded sensors in order to collect and geo-reference environmental information such as ambient temperature, air velocity and orientation and gas concentration. The data collected with the assistant mobile robot is analyzed in order to detect unusual measurements or discrepancies and develop focused corrective ambient actions. This paper shows an example of the measurements performed in a research facility which have enabled the detection and location of an uncomfortable temperature profile inside an office of the research facility. The ambient intelligent application has been developed by performing some localized ambient measurements that have been analyzed in order to propose some ambient actuations to correct the uncomfortable temperature profile. PMID:24681671

[Methods of eliminating alkaloids from the seeds of Lupinus mutabilis Sweet].

PubMed

Torres Tello, F; Nagata, A; Dreifuss Spiegel, W

1980-06-01

The basic purpose of this work was to find a simple and economic method to control and eliminate the presence of alkaloids, as detected by organoleptic or toxicity tests, in Lupinus mutabilis, S. (tarhui) seeds. Taking advantage of the physical and chemical properties of the seeds, they were subjected to four methods of extraction; b) chemical treatment; c) extraction with two solvents, and d) treatment with a modified water-heat process. The results indicated that the most adequate method was the water-heat modified treatment, which showed a yield of 85% and a debittering efficiency of 98.6%, figures which were above those obtained with any of the other treatments studied. The final product had a bland taste without traces of bitterness and a 32% concentration of protein in the kayra line. Amino acid content showed this product to have an unusual high lysine content.

Evidence for a photoprotective function for secondary carotenoids of snow algae

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bidigare, R.R.; Ondrusek, M.E.; Kennicutt, M.C. II

Snow algae occupy a unique habitat in high altitude and polar environments. These algae are often subject to extremes in nutrient availability, acidity, solar irradiance, desiccation, and ambient temperature. This report documents the accumulation of secondary carotenoids by snow algae in response to the availability of nitrogenous nutrients. Unusually large accumulations of astaxanthin esters in extra-chloroplastic lipid globules produce the characteristic red pigmentation typical of some snow algae (e.g., Chlamydomonas nivalis (Bauer) Wille). Consequently, these compounds greatly reduce the amount of light available for absorption by the light-harvesting pigment-protein complexes, thus potentially limiting photoinhibition and photodamage caused by intense solarmore » radiation. The esterification of astaxanthin with fatty acids represents a possible mechanism by which this chromophore can be concentrated within cytoplasmic globules to maximize its photoprotective efficiency. 53 refs., 2 figs., 4 tabs.« less

Non-scaling behavior of electroosmotic flow in voltage-gated nanopores

DOE PAGES

Lian, Cheng; Gallegos, Alejandro; Liu, Honglai; ...

2016-11-17

Ionic transport through nanopores is of fundamental importance for the design and development of nanofiltration membranes and novel electrochemical devices including supercapacitors, fuel cells and batteries. Recent experiments have shown an unusual variation of electrical conductance with the pore size and the electrolyte parameters that defies conventional scaling relations. Here ionic transport through voltage-gated nanopores was studied by using the classical density functional theory for ion distributions in combination with the Navier–Stokes equation for the electroosmotic flow. We also identified a significant influence of the gating potential on the scaling behavior of the conductance with changes in the pore sizemore » and the salt concentration. Finally, for ion transport in narrow pores with a high gating voltage, the conductivity shows an oscillatory dependence on the pore size owing to the strong overlap of electric double layers.« less

Novel surface attachment mechanism of the Streptococcus pneumoniae protein PspA.

PubMed Central

Yother, J; White, J M

1994-01-01

Pneumococcal surface protein A (PspA) of Streptococcus pneumoniae has been found to utilize a novel mechanism for anchoring to the bacterial cell surface. In contrast to that of surface proteins from other gram-positive bacteria, PspA anchoring required choline-mediated interactions between the membrane-associated lipoteichoic acid and the C-terminal repeat region of PspA. Release of PspA from the cell surface could be effected by deletion of 5 of the 10 C-terminal repeat units, by high concentrations of choline, or by growth in choline-deficient medium. Other pneumococcal proteins, including autolysin, which has a similar C-terminal repeat region, were not released by these treatments. The attachment mechanism utilized by PspA thus appears to be uniquely adapted to exploit the unusual structure of the pneumococcal cell surface. Further, it has provided the means for rapid and simple isolation of immunogenic PspA from S. pneumoniae. Images PMID:7910604

Diverse Formation Mechanisms for Compact Galaxies

NASA Astrophysics Data System (ADS)

Kim, Jin-Ah; Paudel, Sanjaya; Yoon, Suk-Jin

2018-01-01

Compact, quenched galaxies such as M32 are unusual ones located off the mass - size scaling relation defined by normal galaxies. Still, their formation mechanisms remain unsolved. Here we investigate the evolution of ~100 compact, quenched galaxies at z = 0 identified in the Illustris cosmological simulation. We identify three ways for a galaxy to become a compact one and, often, multiple mechanisms operate in a combined manner. First, stripping is responsible for making about a third of compact galaxies. Stripping removes stars from galaxies, usually while keeping their sizes intact. About one third are galaxies that cease their growth early on after entering into more massive, gigantic halos. Finally, about half of compact galaxies, ~ 35 % of which turn out to undergo stripping, experience the compaction due to the highly centrally concentrated star formation. We discuss the evolutionary path of compact galaxies on the mass – size plane for each mechanism in a broader context of dwarf galaxy formation and evolution.

Hydrologic data for computation of sediment discharge : Toutle and North Fork Toutle Rivers near Mount St. Helens, Washington, water years 1980-84

USGS Publications Warehouse

Childers, Dallas; Hammond, Stephen E.; Johnson, William P.

1988-01-01

Immediately after the devastating May 18, 1980, eruption of Mount St. Helens, a program was initiated by the U.S. Geological Survey to study the streamflow and sediment characteristics of streams impacted by the eruption. Some of the data gathered in that program are presented in this report. Data are presented for two key sites in the Toutle River basin: North Fork Toutle River near Kid Valley, and Toutle River at Tower Road, near Silver Lake. The types of data presented are appropriate for use with sediment transport formulas; however, the data are also intended for use in a wide variety of additional applications. The data presented in this report are unique because they delineate flow conditions possessing great potential fo sediment transport. The data define unusually high suspended-sediment concentration. Data defining hydraulic, peak discharge, suspended-sediment, and bed-material characteristics are presented. (USGS)

Chemotaxis cluster 1 proteins form cytoplasmic arrays in Vibrio cholerae and are stabilized by a double signaling domain receptor DosM.

PubMed

Briegel, Ariane; Ortega, Davi R; Mann, Petra; Kjær, Andreas; Ringgaard, Simon; Jensen, Grant J

2016-09-13

Nearly all motile bacterial cells use a highly sensitive and adaptable sensory system to detect changes in nutrient concentrations in the environment and guide their movements toward attractants and away from repellents. The best-studied bacterial chemoreceptor arrays are membrane-bound. Many motile bacteria contain one or more additional, sometimes purely cytoplasmic, chemoreceptor systems. Vibrio cholerae contains three chemotaxis clusters (I, II, and III). Here, using electron cryotomography, we explore V. cholerae's cytoplasmic chemoreceptor array and establish that it is formed by proteins from cluster I. We further identify a chemoreceptor with an unusual domain architecture, DosM, which is essential for formation of the cytoplasmic arrays. DosM contains two signaling domains and spans the two-layered cytoplasmic arrays. Finally, we present evidence suggesting that this type of receptor is important for the structural stability of the cytoplasmic array.

Mass extinctions: Ecological selectivity and primary production

NASA Astrophysics Data System (ADS)

Rhodes, Melissa Clark; Thayer, Charles W.

1991-09-01

If mass extinctions were caused by reduced primary productivity, then extinctions should be concentrated among animals with starvation-susceptible feeding modes, active lifestyles, and high-energy budgets. The stratigraphic ranges (by stage) of 424 genera of bivalves and 309 genera of articulate brachiopods suggest that there was an unusual reduction of primary productivity at the Cretaceous/Tertiary (K/T) boundary extinction. For bivalves at the K/T, there were (1) selective extinction of suspension feeders and other susceptible trophic categories relative to deposit feeders and other resistant categories, and (2) among suspension feed-ers, selective extinction of bivalves with active locomotion. During the Permian-Triassic (P/Tr) extinction and Jurassic background time, extinction rates among suspension feeders were greater for articulate brachiopods than for bivalves. But during the K/T event, extinction rates of articulates and suspension-feeding bivalves equalized, possibly because the low-energy budgets of articulates gave them an advantage when food was scarce.

Diagnosis of systemic lupus erythematosus in an unusual presentation: what a primary care physician should know.

PubMed

Pramanik, Bimalendu

2014-01-01

Systemic Lupus Erythematosus (SLE) is a multisystem autoimmune disease affecting millions of people worldwide. It can affect any organ systems of the body. However, all systems may not be involved initially rather than they may be affected gradually, sometimes over years. Diagnosis depends on characteristic clinical features and laboratory test results. Some features such as skin rash, joint symptoms and oral ulcers are common in SLE. But initial presentation of many patients is unusual because either they do not have these common features of the disease or the presentation mimics other illnesses. As a result, delayed diagnosis and misdiagnosis are common. Therefore, high index of initial suspicion of SLE is critical. In clinical practice, SLE should be suspected in any patient presenting with an unexplained disease process involving two or more organ systems. To make a diagnosis in an unusual presentation, thorough clinical evaluation with details history of both present and past illnesses as well as laboratory tests for SLE should be performed. Usually primary-care physicians first evaluate SLE patients; but there is no single article, where all the information on when to suspect SLE in an unusual presentation, is available in an integrated form. In this article, a list of conditions, when SLE should be suspected in an unusual presentation, has been given and some relatively common areas with diagnostic challenges of SLE have been briefly described. To prepare this manuscript, most articles have been identified through 'Pubmed' search using keywords-atypical/ unusual presentation of SLE, case reports on SLE, gastrointestinal manifestations of SLE, neuropsychiatric SLE, diagnostic challenges with SLE, etc. Selected most articles are from currently medline-indexed journals.

Novel electrode systems for amperometric sensing: the case of titanium

NASA Astrophysics Data System (ADS)

Terzi, F.; Pigani, L.; Zanardi, C.; Zanfrognini, B.; Ruggeri, S.; Maccaferri, G.; Seeber, R.

2014-10-01

After working for years on organic materials, e.g., polythiophenes and relevant composites with metal nanoparticles, we shifted our attention to unusual metals, chosen as candidates to effective amperometric sensing on the basis of the atomic structure and crystalline properties. The present contribution aims at proposing an electrode material rarely employed in electroanalysis, namely Ti. We have experimented that the peculiar nature of Ti leads to electrochemical behavior quite different with respect to the conventional electrode materials, including those based on TiO2 (nano)particles. Our work focuses on the determination of strong oxidizing species, namely H2O2 and HClO, and noble metal ions, namely Au(III). Strong oxidizing species are commodity chemicals employed in a number of different industrial processes, in which usually high concentration levels should be monitored. The procedures proposed have been successfully applied also in complex matrices, such as detergent samples. As to Au(III) determination, it also constitutes a crucial tool in order to increase the efficiency of hydrometallurgic processes and of the recovery of precious materials from electronic waste. Ti electrodes allow the determination of dissolved Au species in the presence of other metal ions. In any cases the electrodes exhibit reproducible and repeatable electrochemical responses, even in the presence of high concentration of organic fouling species typical of bio-sorption processes.

Non-ureolytic calcium carbonate precipitation by Lysinibacillus sp. YS11 isolated from the rhizosphere of Miscanthus sacchariflorus.

PubMed

Lee, Yun Suk; Kim, Hyun Jung; Park, Woojun

2017-06-01

Although microbially induced calcium carbonate precipitation (MICP) through ureolysis has been widely studied in environmental engineering fields, urea utilization might cause environmental problems as a result of ammonia and nitrate production. In this study, many non-ureolytic calcium carbonate-precipitating bacteria that induced an alkaline environment were isolated from the rhizosphere of Miscanthus sacchariflorus near an artificial stream and their ability to precipitate calcium carbonate minerals with the absence of urea was investigated. MICP was observed using a phase-contrast microscope and ion-selective electrode. Only Lysinibacillus sp. YS11 showed MICP in aerobic conditions. Energy dispersive X-ray spectrometry and X-ray diffraction confirmed the presence of calcium carbonate. Field emission scanning electron microscopy analysis indicated the formation of morphologically distinct minerals around cells under these conditions. Monitoring of bacterial growth, pH changes, and Ca 2+ concentrations under aerobic, hypoxia, and anaerobic conditions suggested that strain YS11 could induce alkaline conditions up to a pH of 8.9 and utilize 95% of free Ca 2+ only under aerobic conditions. Unusual Ca 2+ binding and its release from cells were observed under hypoxia conditions. Biofilm and extracellular polymeric substances (EPS) formation were enhanced during MICP. Strain YS11 has resistance at high pH and in high salt concentrations, as well as its spore-forming ability, which supports its potential application for self-healing concrete.

Mars Ascent Vehicle Needs Technology Development with a Focus on High Propellant Fractions

NASA Astrophysics Data System (ADS)

Whitehead, J. C.

2018-04-01

Launching from Mars to orbit requires a miniature launch vehicle, beyond any known spacecraft propulsion. The Mars Ascent Vehicle (MAV) needs an unusually high propellant mass fraction. MAV mass has high leverage for the cost of Mars Sample Return.

Modeling steady-state methanogenic degradation of phenols in groundwater

USGS Publications Warehouse

Bekins, Barbara A.; Godsy, E. Michael; Goerlitz, Donald F.

1993-01-01

Field and microcosm observations of methanogenic phenolic compound degradation indicate that Monod kinetics governs the substrate disappearance but overestimates the observed biomass. In this paper we present modeling results from an ongoing multidisciplinary study of methanogenic biodegradation of phenolic compounds in a sand and gravel aquifer contaminated by chemicals and wastes used in wood treatment. Field disappearance rates of four phenols match those determined in batch microcosm studies previously performed by E.M. Godsy and coworkers. The degradation process appears to be at steady-state because even after a sustained influx over several decades, the contaminants still are disappearing in transport downgradient. The existence of a steady-state degradation profile of each substrate together with a low biomass density in the aquifer indicate that the bacteria population is exhibiting no net growth. This may be due to the oligotrophic nature of the biomass population in which utilization and growth are approximately independent of concentration for most of the concentration range. Thus a constant growth rate should exist over much of the contaminated area which may in turn be balanced by an unusually high decay or maintenance rate due to hostile conditions or predation.

Heterogeneous incidence and propagation of spreading depolarizations

PubMed Central

Kaufmann, Dan; Theriot, Jeremy J; Zyuzin, Jekaterina; Service, C Austin; Chang, Joshua C; Tang, Y Tanye; Bogdanov, Vladimir B; Multon, Sylvie; Schoenen, Jean; Ju, Y Sungtaek

2016-01-01

Spreading depolarizations are implicated in a diverse set of neurologic diseases. They are unusual forms of nervous system activity in that they propagate very slowly and approximately concentrically, apparently not respecting the anatomic, synaptic, functional, or vascular architecture of the brain. However, there is evidence that spreading depolarizations are not truly concentric, isotropic, or homogeneous, either in space or in time. Here we present evidence from KCl-induced spreading depolarizations, in mouse and rat, in vivo and in vitro, showing the great variability that these depolarizations can exhibit. This variability can help inform the mechanistic understanding of spreading depolarizations, and it has implications for their phenomenology in neurologic disease. PMID:27562866

Pnc1p-Mediated Nicotinamide Clearance Modifies the Epigenetic Properties of rDNA Silencing in Saccharomyces cerevisiae

PubMed Central

McClure, Julie M.; Gallo, Christopher M.; Smith, Daniel L.; Matecic, Mirela; Hontz, Robert D.; Buck, Stephen W.; Racette, Frances G.; Smith, Jeffrey S.

2008-01-01

The histone deacetylase activity of Sir2p is dependent on NAD+ and inhibited by nicotinamide (NAM). As a result, Sir2p-regulated processes in Saccharomyces cerevisiae such as silencing and replicative aging are susceptible to alterations in cellular NAD+ and NAM levels. We have determined that high concentrations of NAM in the growth medium elevate the intracellular NAD+ concentration through a mechanism that is partially dependent on NPT1, an important gene in the Preiss–Handler NAD+ salvage pathway. Overexpression of the nicotinamidase, Pnc1p, prevents inhibition of Sir2p by the excess NAM while maintaining the elevated NAD+ concentration. This growth condition alters the epigenetics of rDNA silencing, such that repression of a URA3 reporter gene located at the rDNA induces growth on media that either lacks uracil or contains 5-fluoroorotic acid (5-FOA), an unusual dual phenotype that is reminiscent of telomeric silencing (TPE) of URA3. Despite the similarities to TPE, the modified rDNA silencing phenotype does not require the SIR complex. Instead, it retains key characteristics of typical rDNA silencing, including RENT and Pol I dependence, as well as a requirement for the Preiss–Handler NAD+ salvage pathway. Exogenous nicotinamide can therefore have negative or positive impacts on rDNA silencing, depending on the PNC1 expression level. PMID:18780747

A benzimidazole derivative (RCB20) in vitro induces an activation of energetic pathways on Taenia crassiceps (ORF strain) cysticerci.

PubMed

Fraga, Carolina Miguel; da Costa, Tatiane Luiza; de Castro, Ana Maria; Reynoso-Ducoing, Olivia; Ambrosio, Javier; Hernández-Campos, Alicia; Castillo, Rafael; Vinaud, Marina Clare

2017-01-01

Human cysticercosis caused by Taenia crassiceps is unusual; however, it is an useful experimental model for cysticercosis studies. Benzimidazole derivatives are important antihelminthic drugs widely used against helminths. A novel compound 6-chloro-5-(1-naphthyloxy) -2-(trifluoromethyl)-1H-benzimidazole (RCB20) is a benzimidazole derivative less polar and more lipophilic. The aim of this study was to detect the effect of the RCB20 on the in vitro energetic metabolism of T. crassiceps cysticerci. For this, products of the metabolism both produced and secreted/excreted (S/E) by the parasite were detected through spectrophotometry and high performance liquid chromatography after exposure to 6.5 and 13 μM of RCB20 and albendazole sulfoxide (ABZSO). There was a gradual increase in the concentrations of glucose not uptaken by parasites exposed to both concentrations RCB20 and ABZSO. There was a higher concentration of all the organic acids related to the tricarboxilic acid cycle int the parasites exposed to RCB20. The structural differences between RCB20 and ABZSO result in different targets within the parasite and in a greater induction of the energetic pathways, such as the glycolysis and the TCA cycle. RCB20 is a good candidate as a substitute for anthelminthic benzimidazoles due to a differentiated site of action with similar outcome. Copyright © 2016 Elsevier Inc. All rights reserved.

High cesium concentrations in groundwater in the upper 1.2 km of fractured crystalline rock - Influence of groundwater origin and secondary minerals

NASA Astrophysics Data System (ADS)

Mathurin, Frédéric A.; Drake, Henrik; Tullborg, Eva-Lena; Berger, Tobias; Peltola, Pasi; Kalinowski, Birgitta E.; Åström, Mats E.

2014-05-01

Dissolved and solid phase cesium (Cs) was studied in the upper 1.2 km of a coastal granitoid fracture network on the Baltic Shield (Äspö Hard Rock Laboratory and Laxemar area, SE Sweden). There unusually high Cs concentrations (up to 5-6 μg L-1) occur in the low-temperature (<20 °C) groundwater. The material includes water collected in earlier hydrochemical monitoring programs and secondary precipitates (fracture coatings) collected on the fracture walls, as follows: (a) hydraulically pristine fracture groundwater sampled through 23 surface boreholes equipped for the retrieval of representative groundwater at controlled depths (Laxemar area), (b) fracture groundwater affected by artificial drainage collected through 80 boreholes drilled mostly along the Äspö Hard Rock Laboratory (underground research facility), (c) surface water collected in local streams, a lake and sea bay, and shallow groundwater collected in 8 regolith boreholes, and (d) 84 new specimens of fracture coatings sampled in cores from the Äspö HRL and Laxemar areas. The groundwater in each area is different, which affects Cs concentrations. The highest Cs concentrations occurred in deep-seated saline groundwater (median Äspö HRL: 4.1 μg L-1; median Laxemar: 3.7 μg L-1) and groundwater with marine origin (Äspö HRL: 4.2 μg L-1). Overall lower, but variable, Cs concentrations were found in other types of groundwater. The similar concentrations of Cs in the saline groundwater, which had a residence time in the order of millions of years, and in the marine groundwater, which had residence times in the order of years, shows that duration of water-rock interactions is not the single and primary control of dissolved Cs in these systems. The high Cs concentrations in the saline groundwater is ascribed to long-term weathering of minerals, primarily Cs-enriched fracture coatings dominated by illite and mixed-layer clays and possibly wall rock micaceous minerals. The high Cs concentrations in the groundwater of marine origin are, in contrast, explained by relatively fast cation exchange reactions. As indicated by the field data and predicted by 1D solute transport modeling, alkali cations with low-energy hydration carried by intruding marine water are capable of (NH4+ in particular and K+ to some extent) replacing Cs+ on frayed edge (FES) sites on illite in the fracture coatings. The result is a rapid and persistent (at least in the order of decades) buildup of dissolved Cs concentrations in fractures where marine water flows downward. The identification of high Cs concentrations in young groundwater of marine origin and the predicted capacity of NH4+ to displace Cs from fracture solids are of particular relevance in the disposal of radioactive nuclear waste deep underground in crystalline rock.

Synthesis of sodium polyhydrides at high pressures

DOE PAGES

Struzhkin, Viktor V.; Kim, Duck Young; Stavrou, Elissaios; ...

2016-07-28

Archetypal ionic NaH is the only known compound of sodium and hydrogen. Application of high pressure is known to promote states with higher atomic coordination, but extensive searches for polyhydrides with unusual stoichiometry have had only limited success in spite of several theoretical predictions. Here we report the first observation of the formation of polyhydrides of Na (NaH 3 and NaH 7) above 40 GPa and 2,000 K. Moreover, we combine synchrotron X-ray diffraction and Raman spectroscopy in a laser-heated diamond anvil cell and theoretical random structure searching, which both agree on the stable structures and compositions. Our results supportmore » the formation of multicenter bonding in a material with unusual stoichiometry. These results are applicable to the design of new energetic solids and high-temperature superconductors based on hydrogen-rich materials.« less

Legionella feeleii: an unusual organism associated with cutaneous infection in an immunocompromised patient.

PubMed

Verykiou, S; Goodhead, C; Parry, G; Meggitt, S

2018-04-01

We report a 23-year-old immunocompromised woman who, following cardiac transplantation, presented with an unusual cutaneous eruption. She developed a widespread pustular rash, systemic symptoms and a high temperature with raised inflammatory markers. The diagnosis was reached when a skin biopsy was cultured onto Legionella agar (buffered charcoal yeast extract) and Legionella feeleii was isolated. The patient was treated with 6 weeks of moxifloxacin and her cutaneous lesions gradually resolved. Cutaneous Legionella infections are uncommon and usually affect immunocompromised patients. © 2017 British Association of Dermatologists.

Interplay of superconductivity and magnetic fluctuations in single crystals of BaFe2-xCoxAs2

NASA Astrophysics Data System (ADS)

Bag, Biplab; Kumar, Ankit; Banerjee, S. S.; Vinod, K.; Bharathi, A.

2018-04-01

We report unusual pinning response in optimally doped and overdoped single crystals of BaFe2-xCoxAs2. Here we use magneto-optical imaging technique to measure the local magnetization response which shows an unusual transformation from low temperature diamagnetic state to high temperature positive magnetization response. Our data suggests coexistence of magnetic fluctuation along with superconductivity in the optimally doped crystal. The strength of magnetic fluctuations is the strongest in the optimally doped compound with the highest Tc.

Consequences of localized frustration for the folding mechanism of the IM7 protein

PubMed Central

Sutto, Ludovico; Lätzer, Joachim; Hegler, Joseph A.; Ferreiro, Diego U.; Wolynes, Peter G.

2007-01-01

In the laboratory, IM7 has been found to have an unusual folding mechanism in which an “on-pathway” intermediate with nonnative interactions is formed. We show that this intermediate is a consequence of an unusual cluster of highly frustrated interactions in the native structure. This cluster is involved in the binding of IM7 to its target, Colicin E7. Redesign of residues in this cluster to eliminate frustration is predicted by simulations to lead to faster folding without the population of an intermediate ensemble. PMID:18077415

Highly hydroxylated steroids of the starfish Archaster typicus from the Vietnamese waters.

PubMed

Ivanchina, Natalia V; Kicha, Alla A; Huong, Trinh T T; Kalinovsky, Anatoly I; Dmitrenok, Pavel S; Agafonova, Irina G; Long, Pham Q; Stonik, Valentin A

2010-12-01

Five new steroidal compounds, including an unusual glucoside, along with several known steroids were isolated from the starfish Archaster typicus collected in shallow waters of Quang Ninh province (Vietnam). Three new compounds are 27-nor-cholestane derivatives and the other two are 24,26-dihydroxycholestane derivatives. A biogenesis pathway for the unusual side chain of 27-nor-cholestane derivatives is proposed. Isolated compounds presented moderate toxic effects in the sperm- and 8-blastomere tests on embryonal development of the sea urchin Strongylocentrotusintermedius. Copyright 2010 Elsevier Inc. All rights reserved.

An unusual fragmentation of oxetane-embedded tetracyclic ketal systems.

PubMed

Rao, G Hari Mangeswara; Khan, Faiz Ahmed

2013-11-01

An unusual route for the synthesis of functionalized cyclobutane derivatives starting from functionalized norbornane derivatives is reported. Base-induced fragmentation of an oxetanol-type moiety embedded in a tetracyclic norbornyl ketal leads to a cyclobutane-fused derivative as the major or exclusive product. The fragmentation reaction for bridgehead-bromine-substituted derivatives was much faster than for the corresponding chlorine-substituted substrates. The functionalized cyclobutane product was formed exclusively in high yield in the former case, while the latter furnished a minor uncyclized side product in varying yields.

An unusual presentation of primary malignant B-cell-type dural lymphoma

PubMed Central

Low, Yin Yee Sharon; Lai, Siang Hui; Ng, Wai Hoe

2014-01-01

Primary malignant B-cell-type dural lymphoma is a rare subtype of primary central nervous system lymphoma (PCNSL). We herein report an unusual case of diffuse B-cell lymphoma that presents as a chronic subdural haematoma without extracranial involvement. The notable aspects of this case include the patient’s immunocompetence, a short clinical history of symptom onset, rapid neurological deterioration and a final diagnosis of high-grade PCNSL. This case highlights the challenges neurosurgeons face, especially in the emergency setting, when the disease manifests in varied presentations. PMID:25631982

King Tides and Climate Change

EPA Pesticide Factsheets

The highest predicted high tide of the year at a coastal location can bring unusually high water levels and can cause flooding. Learn about these tides including what they are, when they occur, and what they can mean for the future.

Deducing Water Concentrations in the Parent Magma of Cumulate Clinopyroxene and Olivine: Implications for a Hydrous Parent Melt of a Primitive Deccan Lava

NASA Astrophysics Data System (ADS)

Seaman, S. J.

2017-12-01

Water concentrations of clinopyroxene megacrysts in the Powai ankaramite flow, located near Mumbai, Deccan province, India, indicate that the parent magma of the flow hosted at least 4.3 wt.% water, an unusually high water concentration for a continental flood basalt magma. The Powai flow hosts clinopyroxene and olivine phenocrysts. Chatterjee and Sheth (2015) showed that phenocrysts in the flow were part of a cumulate layer intruded by basaltic melt at 6 kb and 1230oC, so the phenocrysts record characteristics of the cumulate parent melt. Clinopyroxene phenocrysts are oscillatorily zoned in water, Mg, Fe, and Ca concentrations, and have concentric bands 100-200 microns thick of 10-20 micron diameter melt inclusions. Olivine phenocrysts host only larger isolated melt inclusions. Zones in the cpx phenocrysts where melt inclusion-rich concentric bands occur have higher concentrations of water than inclusion-free zones. Water concentrations of cpx were used to calculate water concentrations in the melt from which the crystals formed using partition coefficients of Hauri et al. (2004). Water concentrations in the parent magma were between 4.3 and 8.2 wt. % based on water concentrations in cpx. Both Mg and Fe are relatively depleted in the water- and melt inclusion-rich zones in cpx, and Ca is enriched in these zones. Oscillatory zoning in cpx may be a result of repeated growth of cpx in water- richer and water-poorer boundary layers where water lowered melt viscosity and enhanced diffusion and crystal growth rates. Water-enhanced growth rates may have resulted in capture of melt inclusions preserved in water-rich cpx zones. Melt inclusions in olivine phenocrysts preserve lower water concentrations ( 1.2 wt. %) than those indicated by water concentration in cpx phenocrysts. This disparity may be evidence of water loss from melt inclusions in olivine (Gaetani et al., 2009) or may indicate that cpx and ol crystals did not crystallize from the same parent at the same time.

2:1 Charge disproportionation in perovskite-structure oxide La{sub 1/3}Ca{sub 2/3}FeO{sub 3} with unusually-high-valence Fe{sup 3.67+}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guo, Haichuan; Hosaka, Yoshiteru; Seki, Hayato

La{sub 1/3}Ca{sub 2/3}FeO{sub 3} with unusually-high-valence Fe{sup 3.67+} was synthesized at a high pressure and high temperature. The compound crystallizes in a √2a×2a×√2a perovskite cell in which the La and Ca ions at the A site are disordered. At 217 K the Fe{sup 3.67+} shows charge disproportionation to Fe{sup 3+} and Fe{sup 5+} in a ratio of 2:1, and this disproportionation is accompanied by transitions in magnetic and transport properties. The charge-disproportionated Fe{sup 3+} and Fe{sup 5+} are arranged along the <111> direction of the cubic perovskite cell. The local electronic and magnetic environments of Fe in La{sub 1/3}Ca{sub 2/3}FeO{submore » 3} are quite similar to those of Fe in La{sub 1/3}Sr{sub 2/3}FeO{sub 3}, and the 2:1 charge disproportionation pattern of Fe{sup 3+} and Fe{sup 5+} in La{sub 1/3}Ca{sub 2/3}FeO{sub 3} is also the same as that in La{sub 1/3}Sr{sub 2/3}FeO{sub 3}. - Graphical abstract: The perovskite-structure oxide La{sub 1/3}Ca{sub 2/3}FeO{sub 3} with unusually-high-valence Fe{sup 3.67+} shows charge disproportionation to Fe{sup 3+} and Fe{sup 5+} in a ratio of 2:1, and the charge-disproportionated Fe{sup 3+} and Fe{sup 5+} are arranged along the <111> direction of the cubic perovskite cell. - Highlights: • La{sub 1/3}Ca{sub 2/3}FeO{sub 3} with unusually-high-valence Fe{sup 3.67+} was synthesized at a high pressure and high temperature. • At 217 K the Fe{sup 3.67+} shows charge disproportionation (CD) to Fe{sup 3+} and Fe{sup 5+} in a ratio of 2:1. • The charge-disproportionated Fe{sup 3+} and Fe{sup 5+} are arranged along the <111> direction of the cubic perovskite cell. • The disproportionation is accompanied by transitions in magnetic and transport properties.« less

Air quality models and unusually large ozone increases: Identifying model failures, understanding environmental causes, and improving modeled chemistry

NASA Astrophysics Data System (ADS)

Couzo, Evan A.

Several factors combine to make ozone (O3) pollution in Houston, Texas, unique when compared to other metropolitan areas. These include complex meteorology, intense clustering of industrial activity, and significant precursor emissions from the heavily urbanized eight-county area. Decades of air pollution research have borne out two different causes, or conceptual models, of O 3 formation. One conceptual model describes a gradual region-wide increase in O3 concentrations "typical" of many large U.S. cities. The other conceptual model links episodic emissions of volatile organic compounds to spatially limited plumes of high O3, which lead to large hourly increases that have exceeded 100 parts per billion (ppb) per hour. These large hourly increases are known to lead to violations of the federal O 3 standard and impact Houston's status as a non-attainment area. There is a need to further understand and characterize the causes of peak O 3 levels in Houston and simulate them correctly so that environmental regulators can find the most cost-effective pollution controls. This work provides a detailed understanding of unusually large O 3 increases in the natural and modeled environments. First, we probe regulatory model simulations and assess their ability to reproduce the observed phenomenon. As configured for the purpose of demonstrating future attainment of the O3 standard, the model fails to predict the spatially limited O3 plumes observed in Houston. Second, we combine ambient meteorological and pollutant measurement data to identify the most likely geographic origins and preconditions of the concentrated O3 plumes. We find evidence that the O3 plumes are the result of photochemical activity accelerated by industrial emissions. And, third, we implement changes to the modeled chemistry to add missing formation mechanisms of nitrous acid, which is an important radical precursor. Radicals control the chemical reactivity of atmospheric systems, and perturbations to radical budgets can shift chemical pathways. The mechanism additions increase the concentrations of nitrous acid, especially right after sunrise. The overall effect on O3 is small (up to three ppb), but we demonstrate the successful implementation of a surface sub-model that chemically processes adsorbed compounds. To our knowledge, this is the first time that chemical processing on surfaces has been used in a three-dimensional regulatory air quality model.

Assessment of attenuation processes in a chlorinated ethene plume by use of stream bed Passive Flux Meters, streambed Point Velocity Probes and contaminant mass balances

NASA Astrophysics Data System (ADS)

Rønde, V.; McKnight, U. S.; Annable, M. D.; Devlin, J. F.; Cremeans, M.; Sonne, A. T.; Bjerg, P. L.

2017-12-01

Chlorinated ethenes (CE) are abundant groundwater contaminants and pose risk to both groundwater and surface water bodies, as plumes can migrate through aquifers to streams. After release to the environment, CE may undergo attenuation. The hyporheic zone is believed to enhance CE attenuation, however studies contradicting this have also been reported. Since dilution commonly reduces contaminant concentrations in streams to below quantification limits, use of mass balances along the pathway from groundwater to stream is unusual. Our study is conducted at the low-land Grindsted stream, Denmark, which is impacted by a contaminant plume. CE have been observed in the stream water; hence our study site provides an unusual opportunity to study attenuation processes in a CE plume as it migrates through the groundwater at the stream bank, through the stream bed and further to the point of fully mixed conditions in the stream. The study undertook the determination of redox conditions and CE distribution from bank to stream; streambed contaminant flux estimation using streambed Passive Flux Meters (sPFM); and quantification of streambed water fluxes using temperature profiling and streambed Point Velocity Probes (SBPVP). The advantage of the sPFM is that it directly measures the contaminant flux without the need for water samples, while the advantage of the SBPVP is its ability to measure the vertical seepage velocity without the need for additional geological parameters. Finally, a mass balance assessment along the plume pathway was conducted to account for any losses or accumulations. The results show consistencies in spatial patterns between redox conditions and extent of dechlorination; between contaminant fluxes from sPFM and concentrations from water samples; and between seepage velocities from SBPVP and temperature-based water fluxes. Mass balances and parent-metabolite compound ratios indicate limited degradation between the bank and the point of fully mixed stream water. Since the plume at the bank mainly consists of cis-DCE and vinyl chloride, this implies high and persistent stream water concentrations of these compounds. Finally, this study demonstrates the usefulness and complementary nature of sPFM and SBPVP measurements for assessing the attenuation processes through mass balance calculations.

Exclusive nuclear location of estrogen receptors in Squalus testis.

PubMed Central

Callard, G V; Mak, P

1985-01-01

An estrogen (E)-binding molecule having both occupied and unoccupied sites is restricted to nuclear subfractions in the testis of the spiny dogfish (Squalus acanthias). We investigated the hypothesis that a species characterized by high body-fluid osmolarity (1010 mosM) has an estrogen receptor (ER) that binds to chromatin with high affinity and consequently resists redistribution during tissue processing. Although the steroid binding and sedimentation properties of the Squalus nuclear ER conformed to those of classical ER, its elution maximum from DNA-cellulose was unusually high (0.55 M NaCl). A tendency to adhere tightly to cell nuclei was reflected in the high salt concentration (0.43 M KCl) required to extract 50% of the receptors from the nuclear compartment during homogenization and in the stability of the nuclear ER population in the presence of high concentrations of a nonionic solute (urea) or increased buffer volume. Mixing and redistribution experiments showed that nuclear ER could be quantitatively and qualitatively measured in cytosolic extracts, ruling out the possibility that soluble receptors were being masked. Although Squalus oviduct ER was similar to that of testis, ER in the testis and liver of a related elasmobranch (Potamotrygon) that maintains osmotic equilibrium at 300 mosM more closely resembled mammalian ER in its elution maximum from DNA-cellulose (0.22 M NaCl) and cytosolic/nuclear ratios in low-salt buffers. We conclude that Squalus testis has a single ER pool located exclusively in the nuclear compartment. These observations support a revised concept of steroid action and further indicate that the chromatin affinity of the hormone-ER complex is an important factor in determining subfractional distribution during tissue processing. PMID:3856265

Chemical composition of HAL, an isotopically-unusual Allende inclusion

NASA Astrophysics Data System (ADS)

Davis, A. M.; Tanaka, T.; Grossman, L.; Lee, T.; Wasserburg, G. J.

1982-09-01

Samples of hibonite, black rim, and portions of friable rim from an unusual Allende inclusion, named HAL, were analyzed by INAA and RNAA for 37 major, minor, and trace elements. An unusually low amount of Ce was found in HAL, although it otherwise was highly enriched in REE compared to C1 chondrites. HAL is also depleted in Sr, Ba, U, V, Ru, Os, and Ir relative to other refractory elements. It is concluded that the distribution of REE between hibonite and rims was established when hibonite and other refractory minerals were removed at slightly different temperatures from a hot, oxidizing gas in which they previously coexisted as separate grains. Possible locations for the chemical and mass dependent isotopic fractionation are considered to be in ejecta from the low temperature helium-burning zone of a supernova and in the locally oxidizing environment generated by evaporation of interstellar grains of near-chondritic chemical composition.

Chemical composition of HAL, an isotopically-unusual Allende inclusion

NASA Technical Reports Server (NTRS)

Davis, A. M.; Tanaka, T.; Grossman, L.; Lee, T.; Wasserburg, G. J.

1982-01-01

Samples of hibonite, black rim, and portions of friable rim from an unusual Allende inclusion, named HAL, were analyzed by INAA and RNAA for 37 major, minor, and trace elements. An unusually low amount of Ce was found in HAL, although it otherwise was highly enriched in REE compared to C1 chondrites. HAL is also depleted in Sr, Ba, U, V, Ru, Os, and Ir relative to other refractory elements. It is concluded that the distribution of REE between hibonite and rims was established when hibonite and other refractory minerals were removed at slightly different temperatures from a hot, oxidizing gas in which they previously coexisted as separate grains. Possible locations for the chemical and mass dependent isotopic fractionation are considered to be in ejecta from the low temperature helium-burning zone of a supernova and in the locally oxidizing environment generated by evaporation of interstellar grains of near-chondritic chemical composition.

What is really extraordinary in cuprate superconductors?

DOE PAGES

Bozovic, I.; Wu, J.; He, X.; ...

2018-03-07

Over the course of three decades of intense study, apart from the exceptionally high critical temperature, many unusual properties of cuprates have been discovered, notably including resistivity linear in temperature, electronic Raman continuum and optical absorption extending throughout the infrared region, pseudogap, hour-glass spin excitation spectrum, etc. However, each of these features have been also observed in other materials, including some that are not even superconducting at all. Here, we describe an extensive experiment in which over 2,000 films of the La 2-xSr xCuO 4 have been synthesized and studied in detail over the course of the last twelve years.more » We argue here that, uniquely, in the cuprates an unusual superconducting state, that defies the standard BCS description, develops from an unusual metallic state, in which the rotational symmetry of the electron fluid is spontaneously broken.« less

Synthetic Vision System Commercial Aircraft Flight Deck Display Technologies for Unusual Attitude Recovery

NASA Technical Reports Server (NTRS)

Prinzel, Lawrence J., III; Ellis, Kyle E.; Arthur, Jarvis J.; Nicholas, Stephanie N.; Kiggins, Daniel

2017-01-01

A Commercial Aviation Safety Team (CAST) study of 18 worldwide loss-of-control accidents and incidents determined that the lack of external visual references was associated with a flight crew's loss of attitude awareness or energy state awareness in 17 of these events. Therefore, CAST recommended development and implementation of virtual day-Visual Meteorological Condition (VMC) display systems, such as synthetic vision systems, which can promote flight crew attitude awareness similar to a day-VMC environment. This paper describes the results of a high-fidelity, large transport aircraft simulation experiment that evaluated virtual day-VMC displays and a "background attitude indicator" concept as an aid to pilots in recovery from unusual attitudes. Twelve commercial airline pilots performed multiple unusual attitude recoveries and both quantitative and qualitative dependent measures were collected. Experimental results and future research directions under this CAST initiative and the NASA "Technologies for Airplane State Awareness" research project are described.

Unusually large Stokes shift for a near-infrared emitting DNA-stabilized silver nanocluster

NASA Astrophysics Data System (ADS)

Ammitzbøll Bogh, Sidsel; Carro-Temboury, Miguel R.; Cerretani, Cecilia; Swasey, Steven M.; Copp, Stacy M.; Gwinn, Elisabeth G.; Vosch, Tom

2018-04-01

In this paper we present a new near-IR emitting silver nanocluster (NIR-DNA-AgNC) with an unusually large Stokes shift between absorption and emission maximum (211 nm or 5600 cm-1). We studied the effect of viscosity and temperature on the steady state and time-resolved emission. The time-resolved results on NIR-DNA-AgNC show that the relaxation dynamics slow down significantly with increasing viscosity of the solvent. In high viscosity solution, the spectral relaxation stretches well into the nanosecond scale. As a result of this slow spectral relaxation in high viscosity solutions, a multi-exponential fluorescence decay time behavior is observed, in contrast to the more mono-exponential decay in low viscosity solution.

Changes in Naval Aviation Basic Instrument Flight Training: An Analysis.

DTIC Science & Technology

1985-12-01

position to the desired attitude in relation to the horizon [Refs. 4,5: pp.2,16-3]. C. BASIC INSTRUMENT FLIGHT TRAINING The objective of basic...were related to the treatment lecture: 1. Basic Air Work (BAW) 2. Partial Panel 3. Unusual Attitudes (full panel) 4. Initial Climb to Altitude (ICA) 5...of student aviators was compared. The modifi- cations consisted of a lecture concentrating on the fundamentals of attitude instrument flight. One group

A Field of Hollows

NASA Image and Video Library

2015-04-01

Mercury's hollows are among its most distinctive -- and unusual -- surface features. In this stunning view, we see a field of hollows in the western portion of the floor of Zeami impact basin. Hollows populate much of the rest of the basin's interior, with large concentrations several kilometers across occurring in the north and northeast parts of the floor. Individual hollows, however, can be as small as a couple of hundred meters in width. http://photojournal.jpl.nasa.gov/catalog/PIA19267

Phakopsora euvitis Causes Unusual Damage to Leaves and Modifies Carbohydrate Metabolism in Grapevine

PubMed Central

Nogueira Júnior, Antonio F.; Ribeiro, Rafael V.; Appezzato-da-Glória, Beatriz; Soares, Marli K. M.; Rasera, Júlia B.; Amorim, Lilian

2017-01-01

Asian grapevine rust (Phakopsora euvitis) is a serious disease, which causes severe leaf necrosis and early plant defoliation. These symptoms are unusual for a strict biotrophic pathogen. This work was performed to quantify the effects of P. euvitis on photosynthesis, carbohydrates, and biomass accumulation of grapevine. The reduction in photosynthetic efficiency of the green leaf tissue surrounding the lesions was quantified using the virtual lesion concept (β parameter). Gas exchange and responses of CO2 assimilation to increasing intercellular CO2 concentration were analyzed. Histopathological analyses and quantification of starch were also performed on diseased leaves. Biomass and carbohydrate accumulation were quantified in different organs of diseased and healthy plants. Rust reduced the photosynthetic rate, and β was estimated at 5.78, indicating a large virtual lesion. Mesophyll conductance, maximum rubisco carboxylation rate, and regeneration of ribulose-1,5-bisphosphate dependent on electron transport rate were reduced, causing diffusive and biochemical limitations to photosynthesis. Hypertrophy, chloroplast degeneration of mesophyll cells, and starch accumulation in cells close to lesions were observed. Root carbohydrate concentration was reduced, even at low rust severity. Asian grapevine rust dramatically reduced photosynthesis and altered the dynamics of production and accumulation of carbohydrates, unlike strict biotrophic pathogens. The reduction in carbohydrate reserves in roots would support polyetic damage on grapevine, caused by a polycyclic disease. PMID:29018470

Prediction and analysis of near-road concentrations using a reduced-form emission/dispersion model

PubMed Central

2010-01-01

Background Near-road exposures of traffic-related air pollutants have been receiving increased attention due to evidence linking emissions from high-traffic roadways to adverse health outcomes. To date, most epidemiological and risk analyses have utilized simple but crude exposure indicators, most typically proximity measures, such as the distance between freeways and residences, to represent air quality impacts from traffic. This paper derives and analyzes a simplified microscale simulation model designed to predict short- (hourly) to long-term (annual average) pollutant concentrations near roads. Sensitivity analyses and case studies are used to highlight issues in predicting near-road exposures. Methods Process-based simulation models using a computationally efficient reduced-form response surface structure and a minimum number of inputs integrate the major determinants of air pollution exposures: traffic volume and vehicle emissions, meteorology, and receptor location. We identify the most influential variables and then derive a set of multiplicative submodels that match predictions from "parent" models MOBILE6.2 and CALINE4. The assembled model is applied to two case studies in the Detroit, Michigan area. The first predicts carbon monoxide (CO) concentrations at a monitoring site near a freeway. The second predicts CO and PM2.5 concentrations in a dense receptor grid over a 1 km2 area around the intersection of two major roads. We analyze the spatial and temporal patterns of pollutant concentration predictions. Results Predicted CO concentrations showed reasonable agreement with annual average and 24-hour measurements, e.g., 59% of the 24-hr predictions were within a factor of two of observations in the warmer months when CO emissions are more consistent. The highest concentrations of both CO and PM2.5 were predicted to occur near intersections and downwind of major roads during periods of unfavorable meteorology (e.g., low wind speeds) and high emissions (e.g., weekday rush hour). The spatial and temporal variation among predicted concentrations was significant, and resulted in unusual distributional and correlation characteristics, including strong negative correlation for receptors on opposite sides of a road and the highest short-term concentrations on the "upwind" side of the road. Conclusions The case study findings can likely be generalized to many other locations, and they have important implications for epidemiological and other studies. The reduced-form model is intended for exposure assessment, risk assessment, epidemiological, geographical information systems, and other applications. PMID:20579353

The use of minimum selectable concentrations (MSCs) for determining the selection of antimicrobial resistant bacteria.

PubMed

Khan, Sadia; Beattie, Tara K; Knapp, Charles W

2017-03-01

The use of antimicrobial compounds is indispensable in many industries, especially drinking water production, to eradicate microorganisms. However, bacterial growth is not unusual in the presence of disinfectant concentrations that would be typically lethal, as bacterial populations can develop resistance. The common metric of population resistance has been based on the Minimum Inhibitory Concentration (MIC), which is based on bacteria lethality. However, sub-lethal concentrations may also select for resistant bacteria due to the differences in bacterial growth rates. This study determined the Minimal Selective Concentrations (MSCs) of bacterial populations exposed to free chlorine and monochloramine, representing a metric that possibly better reflects the selective pressures occurring at lower disinfectant levels than MIC. Pairs of phylogenetically similar bacteria were challenged to a range of concentrations of disinfectants. The MSCs of free chlorine and monochloramine were found to range between 0.021 and 0.39 mg L -1 , which were concentrations 1/250 to 1/5 than the MICs of susceptible bacteria (MIC susc ). This study indicates that sub-lethal concentrations of disinfectants could result in the selection of resistant bacterial populations, and MSCs would be a more sensitive indicator of selective pressure, especially in environmental systems.

An Unusual Coronal Mass Ejection: First Solar Wind Electron, Proton, Alpha Monitor (SWEPAM) Results from the Advanced Composition Explorer. Appendix 6

NASA Technical Reports Server (NTRS)

McComas, D. J.; Bame, S. J.; Barker, P. L.; Delapp, D. M.; Gosling, J. T.; Skoug, R. M.; Tokar, R. L.; Riley, P.; Feldman, W. C.; Santiago, E.

2001-01-01

This paper reports the first scientific results from the Solar Wind Electron Proton Alpha Monitor (SWEPAM) instrument on board the Advanced Composition Explorer (ACE) spacecraft. We analyzed a coronal mass ejection (CME) observed in the solar wind using data from early February, 1998. This event displayed several of the common signatures of CMEs, such as counterstreaming halo electrons and depressed ion and electron temperatures, as well as some unusual features. During a portion of the CME traversal, SWEPAM measured a very large helium to proton abundance ratio. Other heavy ions, with a set of ionization states consistent with normal (1 to 2x10(exp 6) K) coronal temperatures, were proportionately enhanced at this time. These observations suggest a source for at least some of the CME material, where heavy ions are initially concentrated relative to hydrogen and then accelerated up into the solar wind, independent of their mass and first ionization potential.

Palomar 13: An Unusual Stellar System in the Galactic Halo

NASA Astrophysics Data System (ADS)

Côté, Patrick; Djorgovski, S. G.; Meylan, G.; Castro, Sandra; McCarthy, J. K.

2002-08-01

We report the first results of a program to study the internal kinematics of globular clusters in the outer halo of the Milky Way. Using the Keck telescope and High Resolution Echelle Spectrometer, we have measured precise radial velocities for 30 candidate red giants in the direction of Palomar 13, an object traditionally cataloged as a compact, low-luminosity globular cluster. We have combined these radial velocities with published proper motion membership probabilities and new CCD photometry from the Keck and Canada-France-Hawaii telescopes to isolate a sample of 21 probable members. We find a systemic velocity of s=24.1+/-0.5 km s-1 and a projected, intrinsic velocity dispersion of σp=2.2+/-0.4 km s-1. Although modest, this dispersion is nevertheless several times larger than that expected for a globular cluster of this luminosity and central concentration. Taken at face value, it implies a mass-to-light ratio of ΥV=40+24-17 based on the best-fit King-Michie model. The surface density profile of Palomar 13 also appears unusual compared to most Galactic globular clusters; depending upon the details of background subtraction and model-fitting, Palomar 13 either contains a substantial population of ``extratidal'' stars, or is considerably more spatially extended than previously suspected. The full surface density profile is equally well fitted by a King-Michie model having a high concentration and large tidal radius, or by a Navarro-Frenk-White model. We examine-and tentatively reject-a number of possible origins for the observed characteristics of Palomar 13 (e.g., velocity ``jitter'' among the red giant branch stars, spectroscopic binary stars, nonstandard mass functions, modified Newtonian dynamics) and conclude that the two leading explanations are either catastrophic heating during a recent perigalacticon passage or the presence of a dark matter halo. The available evidence therefore suggests that Palomar 13 is either a globular cluster that is now in the process of dissolving into the Galactic halo or a faint, dark matter-dominated stellar system. Based on data obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and NASA, and was made possible by the generous financial support of the W. M. Keck Foundation.

A Rare Dispersion of Low-Salinity, High-Gelbstoff, High-Primary Production Water in the East China Sea During the Summer of 2010: Possible Influence of the ENSO

NASA Astrophysics Data System (ADS)

Siswanto, Eko; Xu, Yongjiu; Ishizaka, Joji

2018-04-01

We applied ocean color algorithms and a primary production model to a 13-year ocean color data set to assess interannual variations of Changjiang-influenced water (CIW) dispersion, with an emphasis on the unusual CIW dispersion during July 2010. The characteristics of the CIW offshore dispersion were primarily driven by alongshore winds and secondarily by the Changjiang discharge, the interannual variations of which were linked to the El Niño/La Niña. The unusual southeastward dispersion of CIW in July 2010 was attributed to a relatively weak southwesterly wind (with southwesterly wind anomalies) and high Changjiang discharge (after the El Niño peak in winter). In July 2010, the CIW, which is characterized by low-salinity, high-gelbstoff, and high-primary production, intruded into the Kuroshio Current axis to form a rare band of CIW that flowed toward an area south of Japan. The southeastward dispersion of CIW in July 2003 was also unusual, but it did not extend as far as in July 2010, perhaps because of the relatively strong southwesterly winds and low Changjiang discharge in July 2003. During La Niña events, the dispersion of CIW retreated toward the coast due to prevailing northeasterly wind anomalies. We confirmed that the CIW in July 2010 was characterized by low-salinity, abundant phytoplankton biomass, and high biological production. The fact that high biological production and the peak of Changjiang discharge occurred in the same month (July) in 2010 indicated that biogeochemical production stimulated by nutrients from the Changjiang was higher than during normal summer conditions.

High Laccase Expression by Trametes versicolor in a Simulated Textile Effluent with Different Carbon Sources and PHs

PubMed Central

Ottoni, Cristiane; Simões, Marta F.; Fernandes, Sara; Santos, Cledir R.; Lima, Nelson

2016-01-01

Textile effluents are highly polluting and have variable and complex compositions. They can be extremely complex, with high salt concentrations and alkaline pHs. A fixed-bed bioreactor was used in the present study to simulate a textile effluent treatment, where the white-rot fungus, Trametes versicolor, efficiently decolourised the azo dye Reactive Black 5 over 28 days. This occurred under high alkaline conditions, which is unusual, but advantageous, for successful decolourisation processes. Active dye decolourisation was maintained by operation in continuous culture. Colour was eliminated during the course of operation and maximum laccase (Lcc) activity (80.2 U∙L−1) was detected after glycerol addition to the bioreactor. Lcc2 gene expression was evaluated with different carbon sources and pH values based on reverse transcriptase-PCR (polymerase chain reaction). Glycerol was shown to promote the highest lcc2 expression at pH 5.5, followed by sucrose and then glucose. The highest levels of expression occurred between three and four days, which corroborate the maximum Lcc activity observed for sucrose and glycerol on the bioreactor. These results give new insights into the use of T. versicolor in textile dye wastewater treatment with high pHs. PMID:27490563

High-rate nano-crystalline Li 4Ti 5O 12 attached on carbon nano-fibers for hybrid supercapacitors

NASA Astrophysics Data System (ADS)

Naoi, Katsuhiko; Ishimoto, Shuichi; Isobe, Yusaku; Aoyagi, Shintaro

A lithium titanate (Li 4Ti 5O 12)-based electrode which can operate at unusually high current density (300 C) was developed as negative electrode for hybrid capacitors. The high-rate Li 4Ti 5O 12 electrode has a unique nano-structure consisting of unusually small nano-crystalline Li 4Ti 5O 12 (ca. 5-20 nm) grafted onto carbon nano-fiber anchors (nc-Li 4Ti 5O 12/CNF). This nano-structured nc-Li 4Ti 5O 12/CNF composite are prepared by simple sol-gel method under ultra-centrifugal force (65,000 N) followed by instantaneous annealing at 900 °C for 3 min. A model hybrid capacitor cell consisting of a negative nc-Li 4Ti 5O 12/CNF composite electrode and a positive activated carbon electrode showed high energy density of 40 Wh L -1 and high power density of 7.5 kW L -1 comparable to conventional EDLCs.

High water concentrations in a primitive Deccan lava: evidence from clinopyroxene crystals

NASA Astrophysics Data System (ADS)

Seaman, Sheila

2017-04-01

Measurements of water concentrations in clinopyroxene phenocrysts in the Powai ankaramite flow, located near Mumbai, west of the Western Ghats escarpment of the Deccan province, India, indicate that the parent magma of the flow hosted at least 4.3 wt.% water, an unusually high water concentration for a continental flood basalt magma. However, similar water concentrations (3.39 to 6.61 wt.%) were calculated by Xia et al. (2016), also on the basis of water concentrations in clinopyroxene crystals, for continental basalts of the Tarin basin in northwestern China, which hosts >200,000 km3 of flood basalts (Xia et al., 2016). In the Powai ankaramite flow, textural and compositional features of clinopyroxene phenocrysts further support crystallization in a water-rich melt. The flow hosts clinopyroxene and olivine phenocrysts. Chatterjee and Sheth (2015) showed that phenocrysts in the flow were part of a cumulate layer intruded by high-temperature basaltic melt at 6 kb and 1230oC, so the phenocrysts record characteristics of the cumulate parent melt. Clinopyroxene phenocrysts are large (to 0.5 cm diameter), euhedral, are oscillatorily zoned in water, Mg, Fe, and Ca concentrations, and have concentric bands 100-200 microns thick of fine (10-20 micron diameter) melt inclusions. Olivine phenocrysts are smaller (to 0.1 cm diameter, are unzoned, and host only larger isolated melt inclusions. Zones in the cpx phenocrysts where melt inclusion-rich concentric bands occur have higher concentrations of water than inclusion-free zones. Water concentrations of cpx were used to calculate water concentrations in the melt from which the crystals formed using partition coefficients of Hauri et al. (2004). Water concentrations in the parent magma were between 4.35 and 8.26 wt. % based on water concentrations in cpx. Both Mg and Fe are relatively depleted in the water- and melt inclusion-rich zones in cpx, and Ca is enriched in these zones. Oscillatory zoning in cpx may be a result of repeated growth of cpx in water-richer and water-poorer boundary layers in which water lowered melt viscosity and enhanced diffusion and crystal growth rates. Water-enhanced growth rates may have resulted in capture of melt inclusions preserved in water-rich cpx zones. Mg was preferentially incorporated into the cpx, causing Ca and water to build up in the boundary layer, and Mg and Fe to become relatively depleted in the boundary layer, as discussed for oscillatorially-zoned minerals by Wang and Merino (1993). These apparently water-dependent variations in crystal growth processes ugsuggest that at least this Deccan magma was relatively hydrous. Melt inclusions in olivine phenocrysts, however, preserve lower water concentrations ( 1.2 wt. %) than those indicated by water concentration in cpx phenocrysts. This disparity may be evidence of water loss from melt inclusions in olivine (Gaetani et al., 2009) or may indicate that cpx and ol crystals did not crystallize from the same parent at the same time.

Geothermal constraints on enrichment of boron and lithium in salt lakes: An example from a river-salt lake system on the northern slope of the eastern Kunlun Mountains, China

NASA Astrophysics Data System (ADS)

Tan, Hongbing; Chen, Jun; Rao, Wenbo; Zhang, Wenjie; Zhou, Huifang

2012-06-01

Some rivers on the northern slope of the eastern Kunlun Mountains in the Qaidam Basin, China, show very high concentrations of boron and lithium. Correspondingly, the salt lakes fed by these rivers show an unusual enrichment of boron and lithium, and become an important economic resource. The origin of boron and lithium has long been debated. The aim of this study is to analyze the water chemistry and hydrogen and oxygen isotopic composition of river water to understand the unusual enrichment of boron and lithium in the salt lakes of the Qaidam Basin. Oxygen and hydrogen isotope data show that the source of river water in the winter and summer originates from the Kunlun Mountain ice and snow melt water, respectively. The water chemistry shows that boron and lithium contents are high but little variable with seasons in the Nalenggele River and Wutumeiren River waters. By contrast, other rivers have much lower lithium and boron contents. Moreover, the contents of B3+ and Li+ in the river loads or bed sands show little difference amongst the rivers. This indicates that removal by adsorption or input by surface rock weathering is not the main controlling factor of the B3+ and Li+ variation in the rivers. Rivers with high B3+ and Li+ content are chemically similar to geothermal waters in the Tibetan Plateau. In addition, the source area of the Nalenggele River is located in a collision zone of the Kunlun Mountains and Altun Mountains. Large and deep faults can serve as conduits for geothermal fluids. Thus, deep geothermal waters in the source area can easily migrate to the surface and discharge as springs feeding the rivers. They are an important source of B3+ and Li+ to the rivers. The abnormally high contents of B3+ and Li+ in the Nalenggele and Wutumeiren Rivers also suggest that the geothermal source area may be a future target for boron and lithium resources.

Properties and Expression of Na+/K+-ATPase α-Subunit Isoforms in the Brain of the Swamp Eel, Monopterus albus, Which Has Unusually High Brain Ammonia Tolerance

PubMed Central

Chen, Xiu L.; Wee, Nicklaus L. J. E.; Hiong, Kum C.; Ong, Jasmine L. Y.; Chng, You R.; Ching, Biyun; Wong, Wai P.; Chew, Shit F.; Ip, Yuen K.

2013-01-01

The swamp eel, Monopterus albus, can survive in high concentrations of ammonia (>75 mmol l−1) and accumulate ammonia to high concentrations in its brain (∼4.5 µmol g−1). Na+/K+-ATPase (Nka) is an essential transporter in brain cells, and since NH4 + can substitute for K+ to activate Nka, we hypothesized that the brain of M. albus expressed multiple forms of Nka α-subunits, some of which might have high K+ specificity. Thus, this study aimed to clone and sequence the nka α-subunits from the brain of M. albus, and to determine the effects of ammonia exposure on their mRNA expression and overall protein abundance. The effectiveness of NH4 + to activate brain Nka from M. albus and Mus musculus was also examined by comparing their Na+/K+-ATPase and Na+/NH4 +-ATPase activities over a range of K+/NH4 + concentrations. The full length cDNA coding sequences of three nkaα (nkaα1, nkaα3a and nkaα3b) were identified in the brain of M. albus, but nkaα2 expression was undetectable. Exposure to 50 mmol l−1 NH4Cl for 1 day or 6 days resulted in significant decreases in the mRNA expression of nkaα1, nkaα3a and nkaα3b. The overall Nka protein abundance also decreased significantly after 6 days of ammonia exposure. For M. albus, brain Na+/NH4 +-ATPase activities were significantly lower than the Na+/K+-ATPase activities assayed at various NH4 +/K+ concentrations. Furthermore, the effectiveness of NH4 + to activate Nka from the brain of M. albus was significantly lower than that from the brain of M. musculus, which is ammonia-sensitive. Hence, the (1) lack of nkaα2 expression, (2) high K+ specificity of K+ binding sites of Nkaα1, Nkaα3a and Nkaα3b, and (3) down-regulation of mRNA expression of all three nkaα isoforms and the overall Nka protein abundance in response to ammonia exposure might be some of the contributing factors to the high brain ammonia tolerance in M. albus. PMID:24391932

Fate of individual sewage disposal system wastewater within regolith in mountainous terrain

NASA Astrophysics Data System (ADS)

Dano, Kathleen; Poeter, Eileen; Thyne, Geoff

2008-06-01

In order to improve understanding of the fate of septic tank or individual sewage disposal system (ISDS) effluent in regolith overlying fractured-rock aquifers, effluent from an ISDS in such a setting was tracked via geophysical, hydrological, and geochemical methods. Under typical precipitation conditions, the effluent entered the fractured bedrock within 5 m of the boundary of the constructed infiltration area. During a period of unusually high spring recharge, the plume migrated between 50 and 100 m within the regolith before infiltrating the fractured bedrock. The chemical signature of the effluent is similar to that required to account for the decline in water quality, suggesting a causative relationship (as estimated from mass-balance models of the surface-water chemistry near the mouth of the basin). The elevated salt content of the effluent during periods of high natural recharge to the infiltration area correlates with elevated salt concentrations in surface and groundwater at the basin scale, suggesting that some of the effluent salt load may be stored in the unsaturated zone during dry periods and flushed during periods of elevated natural recharge.

A red tide of Alexandrium fundyense in the Gulf of Maine.

PubMed

McGillicuddy, D J; Brosnahan, M L; Couture, D A; He, R; Keafer, B A; Manning, J P; Martin, J L; Pilskaln, C H; Townsend, D W; Anderson, D M

2014-05-01

In early July 2009, an unusually high concentration of the toxic dinoflagellate Alexandrium fundyense occurred in the western Gulf of Maine, causing surface waters to appear reddish brown to the human eye. The discolored water appeared to be the southern terminus of a large-scale event that caused shellfish toxicity along the entire coast of Maine to the Canadian border. Rapid-response shipboard sampling efforts together with satellite data suggest the water discoloration in the western Gulf of Maine was a highly ephemeral feature of less than two weeks in duration. Flow cytometric analysis of surface samples from the red water indicated the population was undergoing sexual reproduction. Cyst fluxes downstream of the discolored water were the highest ever measured in the Gulf of Maine, and a large deposit of new cysts was observed that fall. Although the mechanisms causing this event remain unknown, its timing coincided with an anomalous period of downwelling-favorable winds that could have played a role in aggregating upward-swimming cells. Regardless of the underlying causes, this event highlights the importance of short-term episodic phenomena on regional population dynamics of A. fundyense .

A red tide of Alexandrium fundyense in the Gulf of Maine

NASA Astrophysics Data System (ADS)

McGillicuddy, D. J.; Brosnahan, M. L.; Couture, D. A.; He, R.; Keafer, B. A.; Manning, J. P.; Martin, J. L.; Pilskaln, C. H.; Townsend, D. W.; Anderson, D. M.

2014-05-01

In early July 2009, an unusually high concentration of the toxic dinoflagellate Alexandrium fundyense occurred in the western Gulf of Maine, causing surface waters to appear reddish brown to the human eye. The discolored water appeared to be the southern terminus of a large-scale event that caused shellfish toxicity along the entire coast of Maine to the Canadian border. Rapid-response shipboard sampling efforts together with satellite data suggest the water discoloration in the western Gulf of Maine was a highly ephemeral feature of less than two weeks in duration. Flow cytometric analysis of surface samples from the red water indicated the population was undergoing sexual reproduction. Cyst fluxes downstream of the discolored water were the highest ever measured in the Gulf of Maine, and a large deposit of new cysts was observed that fall. Although the mechanisms causing this event remain unknown, its timing coincided with an anomalous period of downwelling-favorable winds that could have played a role in aggregating upward-swimming cells. Regardless of the underlying causes, this event highlights the importance of short-term episodic phenomena on regional population dynamics of A. fundyense.

Utilization of Microwave Spectroscopy to Identify and Probe Reaction Dynamics of Hsno, a Crucial Biological Signaling Molecule

NASA Astrophysics Data System (ADS)

Nava, Matthew; Martin-Drumel, Marie-Aline; Stanton, John F.; Cummins, Christopher; McCarthy, Michael C.

2016-06-01

Thionitrous acid (HSNO), a potential key intermediate in biological signaling pathways, has been proposed to link NO and H2S biochemistries. Its existence and stability in vivo, however, remain controversial. By means of Fourier-transform microwave spectroscopy, we establish that HSNO is spontaneously formed in high concentration when NO and H2S gases are simply mixed at room temperature in the presence of metallic surfaces. Our measurements reveal that HSNO is formed with high efficiency by the reaction H2S and N2O3 to produce HSNO and HNO2, where N2O3 is a product of NO disproportionation. These studies also suggest that further reaction of HSNO with H2S may form HNO and HSSH. The length of the S--N bond has been derived to high precision from isotopic studies, and is found to be unusually long, 1.84 Å -- the longest S--N bond reported to date for an SNO compound. The present structural and reactivity investigations of this elusive molecule provide a firm fundation to better understand its physiological chemistry and propensity to undergo S--N bond homolysis in vivo.

Venom Concentrations and Clotting Factor Levels in a Prospective Cohort of Russell's Viper Bites with Coagulopathy.

PubMed

Isbister, Geoffrey K; Maduwage, Kalana; Scorgie, Fiona E; Shahmy, Seyed; Mohamed, Fahim; Abeysinghe, Chandana; Karunathilake, Harendra; O'Leary, Margaret A; Gnanathasan, Christeine A; Lincz, Lisa F

2015-01-01

Russell's viper envenoming is a major problem in South Asia and causes venom induced consumption coagulopathy. This study aimed to investigate the kinetics and dynamics of venom and clotting function in Russell's viper envenoming. In a prospective cohort of 146 patients with Russell's viper envenoming, we measured venom concentrations, international normalised ratio [INR], prothrombin time (PT), activated partial thromboplastin time (aPTT), coagulation factors I, II, V, VII, VIII, IX and X, and von Willebrand factor antigen. The median age was 39 y (16-82 y) and 111 were male. The median peak INR was 6.8 (interquartile range [IQR]: 3.7 to >13), associated with low fibrinogen [median,<0.01 g/L; IQR: <0.01-0.9 g/L), low factor V levels [median,<5%; IQR: <5-4%], low factor VIII levels [median,40%; IQR: 12-79%] and low factor X levels [median, 48%; IQR: 29-67%]. There were smaller reductions in factors II, IX and VII over time. All factors recovered over 48 h post-antivenom. The median INR remained >3 at 6 h post-antivenom but had reduced to <2, by 24 h. The aPTT had also returned to close to normal (<50 sec) at 24 h. Factor VII, VIII and IX levels were unusually high pre-antivenom, median peak concentrations of 393%, 307% and 468% respectively. Pre-antivenom venom concentrations and the INR (r = 0.20, p = 0.02) and aPTT (r = 0.19, p = 0.03) were correlated (non-parametric Spearman analysis). Russell's viper coagulopathy results in prolonged aPTT, INR, low fibrinogen, factors V, VIII and X which recover over 48 h. Severity of clotting abnormalities was associated with venom concentrations.

The Dynamics of Rapidly Emplaced Terrestrial Lava Flows and Implications for Planetary Volcanism

NASA Technical Reports Server (NTRS)

Baloga, Stephen; Spudis, Paul D.; Guest, John E.

1995-01-01

The Kaupulehu 1800-1801 lava flow of Hualalai volcano and the 1823 Keaiwa flow from the Great Crack of the Kilauea southwest rift zone had certain unusual and possibly unique properties for terrestrial basaltic lava flows. Both flows apparently had very low viscosities, high effusion rates, and uncommonly rapid rates of advance. Ultramafic xenolith nodules in the 1801 flow form stacks of cobbles with lava rinds of only millimeter thicknesses. The velocity of the lava stream in the 1801 flow was extremely high, at least 10 m/s (more than 40 km/h). Observations and geological evidence suggest similarly high velocities for the 1823 flow. The unusual eruption conditions that produced these lava flows suggest a floodlike mode of emplacement unlike that of most other present-day flows. Although considerable effort has gone into understanding the viscous fluid dynamics and thermal processes that often occur in basaltic flows, the unusual conditions prevalent for the Kaupulehu and Keaiwa flows necessitate different modeling considerations. We propose an elementary flood model for this type of lava emplacement and show that it produces consistent agreement with the overall dimensions of the flow, channel sizes, and other supporting field evidence. The reconstructed dynamics of these rapidly emplaced terrestrial lava flows provide significant insights about the nature of these eruptions and their analogs in planetary volcanism.

Improved high-intensity microwave discharge lamp for atomic resonance absorption and fluorescence spectrometry.

PubMed

Lifshitz, A; Skinner, G B; Wood, D R

1978-09-01

An unusually good combination of high intensity and narrow line has been achieved in a microwave discharge lamp by placing the optical window in the center of the microwave cavity. Construction details and performance characteristics are described.

Hypothyroidism and acute kidney injury: an unusual association.

PubMed

Neves, Precil Diego Miranda de Menezes; Bridi, Ramaiane Aparecida; Balbi, André Luis; Ponce, Daniela

2013-08-09

Association between severe hypothyroidism and acute kidney injury (AKI) is rare. A 40-year-old woman presented with 15 days history of generalised muscle pain, weakness, weight gain and oedema. hypertension and hypothyroidism. dry skin, peripheral/periorbital oedema, slow thought and speaking, thyroid increased. Laboratory examinations: high levels of creatine kinase , creatinine, uric acid and lactate dehydrogenase. Free T4 was very low (<0.3 ng/dL) and thyroid-stimulating hormone was high (21.7 µIU/mL). Urinalysis showed haem pigment without haematuria. We performed the diagnosis of AKI secondary to hypothyroidism-induced rhabdomyolysis. Intravenous fluids were started, urinary alkalisation and increased l-thyroxine dose replacement. On the day after admission, forced diuresis with furosemide was introduced leading to a progressive improvement of symptoms. Although hypothyroidism and AKI is unusual, it should be suspected in patients presenting decrease of renal function and high creatine kinase in the absence of other causes of rhabdomyolysis.

Acoustic Levitation Containerless Processing

NASA Technical Reports Server (NTRS)

Whymark, R. R.; Rey, C. A.

1985-01-01

This research program consists of the development of acoustic containerless processing systems with applications in the areas of research in material sciences, as well as the production of new materials, solid forms with novel and unusual microstructures, fusion target spheres, and improved optical fibers. Efforts have been focused on the containerless processing at high temperatures for producing new kinds of glasses. Also, some development has occurred in the areas of containerlessly supporting liquids at room temperature, with applications in studies of fluid dynamics, potential undercooling of liquids, etc. The high temperature area holds the greatest promise for producing new kinds of glasses and ceramics, new alloys, and possibly unusual structural shapes, such as very uniform hollow glass shells for fusion target applications. High temperature acoustic levitation required for containerless processing has been demonstrated in low-g environments as well as in ground-based experiments. Future activities include continued development of the signals axis acoustic levitator.

Can the fatty acid selectivity of plant lipases be predicted from the composition of the seed triglyceride?

PubMed

Hellyer, S A; Chandler, I C; Bosley, J A

1999-09-22

To address the question can the fatty acid selectivity of plant lipases be predicted from the composition of the seed triglyceride, we have characterised the selectivity of lipases from a wide range of oilseeds with diverse fatty acid compositions. For this study, a novel hydrolysis assay using a fully randomised oil, was developed. From some seed sources (e.g. Cinnamomum camphora), lipases show high preference for particular fatty acids, whilst from others (e.g. Brassica napus, Theobroma cacao80% saturated or 'unusual' fatty acids may contain lipases which exhibit selectivity. It therefore follows that since the majority of seeds are composed of unsaturated fatty acids, that highly selective lipases will be unusual in nature. However lipases from some species of the Cuphea genera show exceptionally high preference for particular fatty acids. For example, lipase from seeds of Cuphea procumbans has over 20-fold selectivity for C10:0.

Asymmetric mass acquisition in LaBi. Topological semimetal candidate

DOE PAGES

Wu, Yun; Kong, Tai; Wang, Lin-Lin; ...

2016-08-18

We use our high resolution He-lamp-based, tunable laser-based angle-resolved photoemission spectroscopy measurements and density functional theory calculations to study the electronic properties of LaBi, a binary system that was proposed to be a member of a new family of topological semimetals. Both bulk and surface bands are present in the spectra. Furthermore, the dispersion of the surface state is highly unusual. It resembles a Dirac cone, but upon closer inspection we can clearly detect an energy gap. The bottom band follows roughly a parabolic dispersion. The dispersion of the top band remains very linear, “V” -shape like, with the tipmore » approaching very closely to the extrapolated location of Dirac point. Finally, such asymmetric mass acquisition is highly unusual and opens a possibility of a new topological phenomenon that has yet to be understood.« less

Increased Prevalence of Unusual Sensory Behaviors in Infants at Risk for, and Teens with, Autism Spectrum Disorder.

PubMed

Van Etten, Hannah M; Kaur, Maninderjit; Srinivasan, Sudha M; Cohen, Shereen J; Bhat, Anjana; Dobkins, Karen R

2017-11-01

The current study investigated the prevalence and pattern of unusual sensory behaviors (USBs) in teens with Autism Spectrum Disorder (ASD) and infants (3-36 months) at risk for ASD. From two different sites (UCSD and UConn), caregivers of infants at high (n = 32) and low risk (n = 33) for ASD, and teenagers with (n = 12) and without ASD (n = 11), completed age-appropriate Sensory Profile questionnaires (Infant/Toddler Sensory Profile; Dunn 2002; Adolescent/Adult Sensory Profile; Brown and Dunn 2002). The results show that high-risk infants and teenagers with ASD exhibit higher-than-typical prevalence of USBs. Results of our distribution analyses investigating the direction of sensory atypicalities (greater-than-typical vs. less-than-typical) revealed a fair degree of consistency amongst teens, however, USB patterns were more varied in high-risk infants.

Exotic Light Nuclei

ERIC Educational Resources Information Center

Cerny, Joseph; Poskanzer, Arthur M.

1978-01-01

Among the light elements, nuclei with unequal numbers of protons and neutrons are highly unstable. Some survive just long enough to be detected and exhibit unusual regimes of radioactive decay. ( Autor/MA)

Evidence for a Dying Magma Chamber at Rábida Island, Galápagos

NASA Astrophysics Data System (ADS)

Bercovici, H.; Geist, D.; Harpp, K. S.; Almeida, M.

2015-12-01

Rábida Island in the Galapagos has experienced both explosive and effusive volcanism. It is located to the east of the most active volcanoes of the Galapagos, and previously determined ages range from 0.9 to 1.1 Ma. An unusually curved escarpment cuts the western sector of the island, which might be part of a caldera wall, although its radius of curvature is much greater than that of the island. Lavas range from basalt to rhyolite, and there are also several intermediate compositions, which are unique in the archipelago. A welded ignimbrite crops out in northeast sector, the only such deposit known in the entire region. The volumetric proportion of evolved rocks is unusually high; 25% of the rocks in our comprehensive sample set are intermediate to felsic. The siliceous rocks occur in two clusters in the southern and southwestern sections of the island, suggesting two separate sources. The intermediate rocks are concentrated in the center and northwestern parts of the island. Despite these foci of more siliceous lavas, basalt is the most widespread rock type across the island. It is notable that Rabida is immediately east of Volcan Alcedo, which is the only active Galápagos volcano that has also erupted rhyolite, and south of Santiago Island, which erupted the trachyte dome observed by Charles Darwin in 1835. These observations, in conjunction with the cumulate xenoliths observed in Rábida explosive deposits, are consistent with the evolved rocks resulting from fractional crystallization of a dying magma chamber, as the volcano is carried away from the hotspot.

Geochemistry and field geology of shoshonitic magmas in the Late Cretaceous foreland fold and thrust belt of southwestern Montana: Results from the North Doherty Mountain Intrusive Complex

NASA Astrophysics Data System (ADS)

Beranek, L. P.; Burton, B. R.; Ihinger, P. D.

2002-12-01

The North Doherty Mountain Intrusive Complex (NDMIC) is one of several satellite plutons related to the areally extensive Boulder batholith of southwestern Montana. The Boulder batholith comprises multiple plutons and intrusive phases, and the magmatism has long been thought to be the result of subduction due to its calc-alkaline granodioritic composition. The batholith is situated in the Helena salient, which differs from other parts of the North American Cordilleran foreland because there, magmatism spatially and temporally overlaps with deformation in the foreland fold and thrust belt. The North Doherty Mountain Intrusive Complex (NDMIC) is one of several satellite plutons related to the Boulder batholith and represents an ideal microcosm of the batholith for petrogenetic and structural studies because it exposes both mafic and felsic units and was emplaced in the limb of a major thrust related fold. We present new geologic mapping and detailed trace element geochemical analyses to show that the entire mafic-to-felsic suite of rocks in the NDMIC are cogenetic and shoshonitic in character. Shoshonites are unusual magmas that are distinguished by their high concentrations of K, Rb, Sr, Ba, Zr, and Th contents, and are thought to represent partial melting at great depths within the mantle wedge above a subducting slab. The presence of shoshonitic magma in the Cordilleran foreland fold and thrust belt provides important clues into the nature of the formation of this unusual magma type and can provide insights into our understanding of magmatism in foreland structural settings.

Enhanced Magnetization of Cobalt Defect Clusters Embedded in TiO 2-δ Films

DOE PAGES

Cortie, David L.; Khaydukov, Yury; Keller, Thomas; ...

2017-02-23

High magnetizations are desirable for spintronic devices that operate by manipulating electronic states using built-in magnetic fields. However, the magnetic moment in promising dilute magnetic oxide nanocomposites is very low, typically corresponding to only fractions of a Bohr magneton for each dopant atom. In this study, we report a large magnetization formed by ion implantation of Co into amorphous TiO 2-δ films, producing an inhomogeneous magnetic moment, with certain regions producing over 2.5 μ B per Co, depending on the local dopant concentration. Polarized neutron reflectometry was used to depth-profile the magnetization in the Co:TiO 2-δ nanocomposites, thus confirming themore » pivotal role of the cobalt dopant profile inside the titania layer. X-ray photoemission spectra demonstrate the dominant electronic state of the implanted species is Co 0, with a minor fraction of Co 2+. The detected magnetizations have seldom been reported before and lie near the upper limit set by Hund’s rules for Co 0, which is unusual because the transition metal’s magnetic moment is usually reduced in a symmetric 3D crystal-field environment. Low-energy positron annihilation lifetime spectroscopy indicates that defect structures within the titania layer are strongly modified by the implanted Co. We propose that a clustering motif is promoted by the affinity of the positively charged implanted species to occupy microvoids native to the amorphous host. This provides a seed for subsequent doping and nucleation of nanoclusters within an unusual local environment.« less

Biogeochemistry and nitrogen cycling in an Arctic, volcanic ecosystem

NASA Astrophysics Data System (ADS)

Fogel, M. L.; Benning, L.; Conrad, P. G.; Eigenbrode, J.; Starke, V.

2007-12-01

As part of a study on Mars Analogue environments, the biogeochemistry of Sverrefjellet Volcano, Bocfjorden, Svalbard, was conducted and compared to surrounding glacial, thermal spring, and sedimentary environments. An understanding of how nitrogen might be distributed in a landscape that had extinct or very cold adapted, slow- growing extant organisms should be useful for detecting unknown life forms. From high elevations (900 m) to the base of the volcano (sea level), soil and rock ammonium concentrations were uniformly low, typically less than 1- 3 micrograms per gm of rock or soil. In weathered volcanic soils, reduced nitrogen concentrations were higher, and oxidized nitrogen concentrations lower. The opposite was found in a weathered Devonian sedimentary soil. Plants and lichens growing on volcanic soils have an unusually wide range in N isotopic compositions from -5 to +12‰, a range rarely measured in temperate ecosystems. Nitrogen contents and isotopic compositions of volcanic soils and rocks were strongly influenced by the presence or absence of terrestrial herbivores or marine avifauna with higher concentrations of N and elevated N isotopic compositions occurring as patches in areas immediately influenced by reindeer, Arctic fox ( Alopex lagopus), and marine birds. Because of the extreme conditions in this area, ephemeral deposition of herbivore feces results in a direct and immediate N pulses into the ecosystem. The lateral extent and distribution of marine- derived nitrogen was measured on a landscape scale surrounding an active fox den. Nitrogen was tracked from the bones of marine birds to soil to vegetation. Because of extreme cold, slow biological rates and nitrogen cycling, a mosaic of N patterns develops on the landscape scale.

Investigation of hydrophobic contaminants in an urban slough system using passive sampling - Insights from sampling rate calculations

USGS Publications Warehouse

McCarthy, K.

2008-01-01

Semipermeable membrane devices (SPMDs) were deployed in the Columbia Slough, near Portland, Oregon, on three separate occasions to measure the spatial and seasonal distribution of dissolved polycyclic aromatic hydrocarbons (PAHs) and organochlorine compounds (OCs) in the slough. Concentrations of PAHs and OCs in SPMDs showed spatial and seasonal differences among sites and indicated that unusually high flows in the spring of 2006 diluted the concentrations of many of the target contaminants. However, the same PAHs - pyrene, fluoranthene, and the alkylated homologues of phenanthrene, anthracene, and fluorene - and OCs - polychlorinated biphenyls, pentachloroanisole, chlorpyrifos, dieldrin, and the metabolites of dichlorodiphenyltrichloroethane (DDT) - predominated throughout the system during all three deployment periods. The data suggest that storm washoff may be a predominant source of PAHs in the slough but that OCs are ubiquitous, entering the slough by a variety of pathways. Comparison of SPMDs deployed on the stream bed with SPMDs deployed in the overlying water column suggests that even for the very hydrophobic compounds investigated, bed sediments may not be a predominant source in this system. Perdeuterated phenanthrene (phenanthrene-d10). spiked at a rate of 2 ??g per SPMD, was shown to be a reliable performance reference compound (PRC) under the conditions of these deployments. Post-deployment concentrations of the PRC revealed differences in sampling conditions among sites and between seasons, but indicate that for SPMDs deployed throughout the main slough channel, differences in sampling rates were small enough to make site-to-site comparisons of SPMD concentrations straightforward. ?? Springer Science+Business Media B.V. 2007.

A case of lead poisoning due to snooker chalk

PubMed Central

Dargan, P; Evans, P; House, I; Jones, A

2000-01-01

A 3 year, 9 month old child with pica presented with a blood lead concentration of 1.74 µmol/l (360 µg/l). The source of poisoning was snooker chalk (lead content 7200 µg/g). She was treated with intravenous calcium disodium edetate chelation. Thirty months later her blood lead was 0.39 µmol/l (80 µg/l). This case illustrates the need to be vigilant for more unusual causes of lead poisoning in the home.

 PMID:11087293

Essential but Not Vulnerable: Indazole Sulfonamides Targeting Inosine Monophosphate Dehydrogenase as Potential Leads against Mycobacterium tuberculosis.

PubMed

Park, Yumi; Pacitto, Angela; Bayliss, Tracy; Cleghorn, Laura A T; Wang, Zhe; Hartman, Travis; Arora, Kriti; Ioerger, Thomas R; Sacchettini, Jim; Rizzi, Menico; Donini, Stefano; Blundell, Tom L; Ascher, David B; Rhee, Kyu; Breda, Ardala; Zhou, Nian; Dartois, Veronique; Jonnala, Surendranadha Reddy; Via, Laura E; Mizrahi, Valerie; Epemolu, Ola; Stojanovski, Laste; Simeons, Fred; Osuna-Cabello, Maria; Ellis, Lucy; MacKenzie, Claire J; Smith, Alasdair R C; Davis, Susan H; Murugesan, Dinakaran; Buchanan, Kirsteen I; Turner, Penelope A; Huggett, Margaret; Zuccotto, Fabio; Rebollo-Lopez, Maria Jose; Lafuente-Monasterio, Maria Jose; Sanz, Olalla; Diaz, Gracia Santos; Lelièvre, Joël; Ballell, Lluis; Selenski, Carolyn; Axtman, Matthew; Ghidelli-Disse, Sonja; Pflaumer, Hannah; Bösche, Markus; Drewes, Gerard; Freiberg, Gail M; Kurnick, Matthew D; Srikumaran, Myron; Kempf, Dale J; Green, Simon R; Ray, Peter C; Read, Kevin; Wyatt, Paul; Barry, Clifton E; Boshoff, Helena I

2017-01-13

A potent, noncytotoxic indazole sulfonamide was identified by high-throughput screening of >100,000 synthetic compounds for activity against Mycobacterium tuberculosis (Mtb). This noncytotoxic compound did not directly inhibit cell wall biogenesis but triggered a slow lysis of Mtb cells as measured by release of intracellular green fluorescent protein (GFP). Isolation of resistant mutants followed by whole-genome sequencing showed an unusual gene amplification of a 40 gene region spanning from Rv3371 to Rv3411c and in one case a potential promoter mutation upstream of guaB2 (Rv3411c) encoding inosine monophosphate dehydrogenase (IMPDH). Subsequent biochemical validation confirmed direct inhibition of IMPDH by an uncompetitive mode of inhibition, and growth inhibition could be rescued by supplementation with guanine, a bypass mechanism for the IMPDH pathway. Beads containing immobilized indazole sulfonamides specifically interacted with IMPDH in cell lysates. X-ray crystallography of the IMPDH-IMP-inhibitor complex revealed that the primary interactions of these compounds with IMPDH were direct pi-pi interactions with the IMP substrate. Advanced lead compounds in this series with acceptable pharmacokinetic properties failed to show efficacy in acute or chronic murine models of tuberculosis (TB). Time-kill experiments in vitro suggest that sustained exposure to drug concentrations above the minimum inhibitory concentration (MIC) for 24 h were required for a cidal effect, levels that have been difficult to achieve in vivo. Direct measurement of guanine levels in resected lung tissue from tuberculosis-infected animals and patients revealed 0.5-2 mM concentrations in caseum and normal lung tissue. The high lesional levels of guanine and the slow lytic, growth-rate-dependent effect of IMPDH inhibition pose challenges to developing drugs against this target for use in treating TB.

Factors Affecting Source-Water Quality after Disturbance of Forests by Wildfire

NASA Astrophysics Data System (ADS)

Murphy, S. F.; Martin, D. A.; McCleskey, R. B.; Writer, J. H.

2015-12-01

Forests yield high-quality water supplies to communities throughout the world, in part because forest cover reduces flooding and the consequent transport of suspended and dissolved constituents to surface water. Disturbance by wildfire reduces or eliminates forest cover, leaving watersheds susceptible to increased surface runoff during storms and reduced ability to retain contaminants. We assessed water-quality response to hydrologic events for three years after a wildfire in the Fourmile Creek Watershed, near Boulder, Colorado, and found that hydrologic and geochemical responses downstream of a burned area were primarily driven by small, brief convective storms that had relatively high, but not unusual, rainfall intensity. Total suspended sediment, dissolved organic carbon, nitrate, and manganese concentrations were 10-156 times higher downstream of a burned area compared to upstream, and water quality was sufficiently impaired to pose water-treatment concerns. The response in both concentration and yield of water-quality constituents differed depending on source availability and dominant watershed processes controlling the constituent. For example, while all constituent concentrations were highest during storm events, annual sediment yields downstream of the burned area were controlled by storm events and subsequent mobilization, whereas dissolved organic carbon yields were more dependent on spring runoff from upstream areas. The watershed response was affected by a legacy of historical disturbance: the watershed had been recovering from extensive disturbance by mining, railroad and road development, logging, and fires in the late 19th and early 20th centuries, and we observed extensive erosion of mine waste in response to these summer storms. Therefore, both storm characteristics and historical disturbance in a burned watershed must be considered when evaluating the role of wildfire on water quality.

Concentrations, sources and geochemistry of airborne particulate matter at a major European airport.

PubMed

Amato, Fulvio; Moreno, Teresa; Pandolfi, Marco; Querol, Xavier; Alastuey, Andrés; Delgado, Ana; Pedrero, Manuel; Cots, Nuria

2010-04-01

Monitoring of aerosol particle concentrations (PM(10), PM(2.5), PM(1)) and chemical analysis (PM(10)) was undertaken at a major European airport (El Prat, Barcelona) for a whole month during autumn 2007. Concentrations of airborne PM at the airport were close to those at road traffic hotspots in the nearby Barcelona city, with means measuring 48 microg PM(10)/m(3), 21 microg PM(2.5)/m(3) and 17 microg PM(1)/m(3). Meteorological controls on PM at El Prat are identified as cleansing daytime sea breezes with abundant coarse salt particles, alternating with nocturnal land-sourced winds which channel air polluted by industry and traffic (PM(1)/PM(10) ratios > 0.5) SE down the Llobregat Valley. Chemical analyses of the PM(10) samples show that crustal PM is dominant (38% of PM(10)), followed by total carbon (OC + EC, 25%), secondary inorganic aerosols (SIA, 20%), and sea salt (6%). Local construction work for a new airport terminal was an important contributor to PM(10) crustal levels. Source apportionment modelling PCA-MLRA identifies five factors: industrial/traffic, crustal, sea salt, SIA, and K(+) likely derived from agricultural biomass burning. Whereas most of the atmospheric contamination concerning ambient air PM(10) levels at El Prat is not attributable directly to aircraft movement, levels of carbon are unusually high (especially organic carbon), as are metals possibly sourced from tyre detritus/smoke in runway dust (Ba, Zn, Mo) and from brake dust in ambient PM(10) (Cu, Sb), especially when the airport is at its most busy. We identify microflakes of aluminous alloys in ambient PM(10) filters derived from corroded fuselage and wings as an unequivocal and highly distinctive tracer for aircraft movement.

Negative response of photosynthesis to natural and projected high seawater temperatures estimated by pulse amplitude modulation fluorometry in a temperate coral.

PubMed

Caroselli, Erik; Falini, Giuseppe; Goffredo, Stefano; Dubinsky, Zvy; Levy, Oren

2015-01-01

Balanophyllia europaea is a shallow water solitary zooxanthellate coral, endemic to the Mediterranean Sea. Extensive field studies across a latitudinal temperature gradient highlight detrimental effects of rising temperatures on its growth, demography, and skeletal characteristics, suggesting that depression of photosynthesis at high temperatures might cause these negative effects. Here we test this hypothesis by analyzing, by means of pulse amplitude modulation fluorometry, the photosynthetic efficiency of B. europaea specimens exposed in aquaria to the annual range of temperatures experienced in the field (13, 18, and 28°C), and two extreme temperatures expected for 2100 as a consequence of global warming (29 and 32°C). The indicators of photosynthetic performance analyzed (maximum and effective quantum yield) showed that maximum efficiency was reached at 20.0-21.6°C, slightly higher than the annual mean temperature in the field (18°C). Photosynthetic efficiency decreased from 20.0 to 13°C and even more strongly from 21.6 to 32°C. An unusual form of bleaching was observed, with a maximum zooxanthellae density at 18°C that strongly decreased from 18 to 32°C. Chlorophyll a concentration per zooxanthellae cell showed an opposite trend as it was minimal at 18°C and increased from 18 to 32°C. Since the areal chlorophyll concentration is the product of the zooxanthellae density and its cellular content, these trends resulted in a homogeneous chlorophyll concentration per coral surface across temperature treatments. This confirms that B. europaea photosynthesis is progressively depressed at temperatures >21.6°C, supporting previous hypotheses raised by the studies on growth and demography of this species. This study also confirms the threats posed to this species by the ongoing seawater warming.

A different type of 'glue ear': report of an unusual case of prominent ears.

PubMed

Purcell, Elizabeth M; O'Neill, Ann C; Regan, Padraic J

2003-09-01

Prominent ears is a condition that can cause extreme psychological distress in young people. This cosmetic deformity can be corrected by otoplasty, an outpatient surgical procedure that is associated with a high rate of patient satisfaction. We report the unusual case of a teenage boy who had repeatedly applied cyanoacrylate adhesive ("superglue") to his postauricular skin in an attempt to pin back his prominent ears. This case of "glue ear" was ultimately resolved by successful otoplasty, although the residual effects of the glue resulted in delayed healing of the surgical wound.

An unusual slowdown of fast diffusion in a room temperature

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chathoth,; Mamontov, Eugene; Fulvio, Pasquale F

2013-01-01

Using quasielastic neutron scattering in the temperature range from 290 to 350 K, we show that the diffusive motions in a room temperature ionic liquid [H2NC(dma)2][BETI] become faster for a fraction of cations when the liquid is confined in a mesoporous carbon. This applies to both the localized and long-range translational diffusive motions of the highly mobile cations, although the former exhibit an unusual trend of slowing-down as the temperature is increased, until the localized diffusivity is reduced to the bulk ionic liquid value at a temperature of 350 K.

Uniportal anatomic combined unusual segmentectomies.

PubMed

González-Rivas, Diego; Lirio, Francisco; Sesma, Julio

2017-01-01

Nowadays, sublobar anatomic resections are gaining momentum as a valid alternative for early stage lung cancer. Despite being technically demanding, anatomic segmentectomies can be performed by uniportal video-assisted thoracic surgery (VATS) approach to combine the benefits of minimally invasiveness with the maximum lung sparing. This procedure can be even more complex if a combined resection of multiple segments from different lobes has to be done. Here we report five cases of combined and unusual segmentectomies done by the same experienced surgeon in high volume institutions to show uniportal VATS is a feasible approach for these complex resections and to share an excellent educational resource.

Refractory inclusions in the Ornans C30 chondrite

NASA Technical Reports Server (NTRS)

Davis, A. M.

1985-01-01

Several types of metedorites contain unusual objects 10 micrometers to 2 centimeters across that are enriched in refractory elements such as calcium, aluminum and titanium. These objects, commonly known as refractory inclusions, are most abundant in the meteorites known as carbonaceous chondrites. The refractory inclusions that have been found in the Ornans metedorite, a member of a little-studied group of carbonaceous chondrites are described. Some refractory inclusions in Ornans resemble those found in other meteorites, while others are unlike any seen before. The unusual inclusions in Ornans contain minerals with extraordinary enrichments in highly refractory elements.

Migrating foreign body in the tracheobronchial tree: an unusual case of firework penetrating neck injury.

PubMed

Khan, M Sarwar; Kirkland, P M; Kumar, R

2002-02-01

Firework injuries can manifest themselves in many different ways; usually as an explosive or burn injury. This case describes an unusual presentation of a firework penetrating injury resulting in a sharp coiled metal foreign body travelling through a small entry wound in the neck and subsequently lodging itself in the tracheobronchial tree. A foreign body such as this can potentially travel a considerable distance through the soft tissues and end up in an unsuspecting distant site. There must, therefore, be a high index of suspicion with the appropriate radiological investigations for appropriate management of such cases.

Unusually severe food poisoning from vanilla slices.

PubMed Central

Fenton, P. A.; Dobson, K. W.; Eyre, A.; McKendrick, M. W.

1984-01-01

Thirty six people suffered from severe vomiting and diarrhoea 15 min to 3 h after eating vanilla slices from the same bakery. Five patients were admitted to hospital, and one developed unusual skin lesions after admission. Staphylococcus aureus was isolated in large numbers from vanilla slices of the same batch as those giving rise to symptoms, and from five faecal specimens obtained from affected persons. Bacillus cereus and Bacillus subtilis were also isolated from the slices. Unbaked custard provides an ideal environment for bacterial multiplication, especially when (as on this occasion) the ambient temperature is persistently high. PMID:6438231

Global scale concentrations of volcanic activity on Venus: A summary of three 23rd Lunar and Planetary Science Conference abstracts. 1: Venus volcanism: Global distribution and classification from Magellan data. 2: A major global-scale concentration of volcanic activity in the Beta-Atla-Themis region of Venus. 3: Two global concentrations of volcanism on Venus: Geologic associations and implications for global pattern of upwelling and downwelling

NASA Technical Reports Server (NTRS)

Crumpler, L. S.; Aubele, Jayne C.; Head, James W.; Guest, J.; Saunders, R. S.

1992-01-01

As part of the analysis of data from the Magellan Mission, we have compiled a global survey of the location, dimensions, and subsidiary notes of all identified volcanic features on Venus. More than 90 percent of the surface area was examined and the final catalog comprehensively identifies 1548 individual volcanic features larger than approximately 20 km in diameter. Volcanic features included are large volcanoes, intermediate volcanoes, fields of small shield volcanoes, calderas, large lava channels, and lava floods as well as unusual features first noted on Venus such as coronae, arachnoids, and novae.

Space Radiation Effects and Reliability Consideration for the Proposed Jupiter Europa Orbiter

NASA Technical Reports Server (NTRS)

Johnston, Allan

2011-01-01

The proposed Jupiter Europa Orbiter (JEO) mission to explore the Jovian moon Europa poses a number of challenges. The spacecraft must operate for about seven years during the transit time to the vicinity of Jupiter, and then endure unusually high radiation levels during exploration and orbiting phases. The ability to withstand usually high total dose levels is critical for the mission, along with meeting the high reliability standards for flagship NASA missions. Reliability of new microelectronic components must be sufficiently understood to meet overall mission requirements.The proposed Jupiter Europa Orbiter (JEO) mission to explore the Jovian moon Europa poses a number of challenges. The spacecraft must operate for about seven years during the transit time to the vicinity of Jupiter, and then endure unusually high radiation levels during exploration and orbiting phases. The ability to withstand usually high total dose levels is critical for the mission, along with meeting the high reliability standards for flagship NASA missions. Reliability of new microelectronic components must be sufficiently understood to meet overall mission requirements.

The biosynthesis of nitrogen-, sulfur-, and high-carbon chain-containing sugars.

PubMed

Lin, Chia-I; McCarty, Reid M; Liu, Hung-wen

2013-05-21

Carbohydrates serve many structural and functional roles in biology. While the majority of monosaccharides are characterized by the chemical composition (CH2O)n, modifications including deoxygenation, C-alkylation, amination, O- and N-methylation, which are characteristic of many sugar appendages of secondary metabolites, are not uncommon. Interestingly, some sugar molecules are formed via modifications including amine oxidation, sulfur incorporation, and "high-carbon" chain attachment. Most of these unusual sugars have been identified over the past several decades as components of microbially produced natural products, although a few high-carbon sugars are also found in the lipooligosaccharides of the outer cell walls of Gram-negative bacteria. Despite their broad distribution in nature, these sugars are considered "rare" due to their relative scarcity. The biosynthetic steps that underlie their formation continue to perplex researchers to this day and many questions regarding key transformations remain unanswered. This review will focus on our current understanding of the biosynthesis of unusual sugars bearing oxidized amine substituents, thio-functional groups, and high-carbon chains.

Size-resolved chemical composition of aerosol emitted by Erebus volcano, Antarctica

NASA Astrophysics Data System (ADS)

Ilyinskaya, E.; Oppenheimer, C.; Mather, T. A.; Martin, R. S.; Kyle, P. R.

2010-03-01

Persistent, open-vent degassing of Erebus volcano, Antarctica, is a significant point source of gases and aerosol to the austral polar troposphere. We report here on the chemical composition and size distribution of the Erebus aerosol, focusing on the water-soluble fraction. The aerosol was sampled at the rim of the active crater using a cascade impactor, which collected and sized particles in 14 size bins from >10 to 0.01 μm. The soluble fraction of the Erebus aerosol is distinct from other volcanic sources in several respects. It is dominated by chloride-bearing particles (over 30% of total mass) and has an unusually high Cl-/SO42- molar ratio of 3.5. Coarse particles contribute little to the total mass of the soluble fraction. Elevated concentrations of F-, Cl-, Br-, and SO42- are found in a narrow particle size fraction of 0.1-0.25 μm. The detection of particulate Br- reinforces our understanding of the potential for quiescent volcanic emissions to deplete tropospheric ozone. The small aerosol size reflects the low atmospheric temperature and humidity, which inhibit particle growth. Halide-alkali metal salts (Na, K)(Cl, F) appear to be the most abundant species in the aerosol. The concentration of Pb is high compared to other volcanoes; its exsolution may be promoted by the high abundance of halogens in Erebus magma. Despite the previously reported high NOx content in the plume, we did not detect significant quantities of nitrate in the near-vent aerosol. Our findings emphasize the potential regional significance of emissions from Erebus for understanding the Antarctic atmospheric composition and glaciochemical records.

Arsenic concentrations in Baltic Sea sediments close to chemical munitions dumpsites

NASA Astrophysics Data System (ADS)

Bełdowski, Jacek; Szubska, Marta; Emelyanov, Emelyan; Garnaga, Galina; Drzewińska, Anna; Bełdowska, Magdalena; Vanninen, Paula; Östin, Anders; Fabisiak, Jacek

2016-06-01

In addition to natural sources and land-originated pollution, the Baltic Sea has another anthropogenic source of arsenic in bottom sediments-arsenic-based Chemical Warfare Agents (CWA). To examine the potential usage of arsenic contents results for monitoring the leakage from chemical weapons, sediment samples were collected from officially reported and potential chemical weapon dumpsites located in the Baltic Sea, and total and inorganic arsenic concentrations were analyzed. Results showed an elevated arsenic content in dumpsite areas compared to reference areas. Correlations of arsenic with other metals and organic matter were studied to elucidate any unusual behavior of arsenic in the dumpsites. In the area of the Bornholm Deep, such behavior was observed for inorganic arsenic. It appears that in close vicinity of dumped munitions, the inorganic arsenic concentration of sediments is not correlated with either organic matter content or authigenic minerals formation, as is commonly observed elsewhere. Investigations on CWA concentrations, performed within the CHEMSEA (Chemical Munition Search and Assesment) project, allowed us to compare the results of arsenic concentrations with the occurrence of arsenic-containing CWA.

Morphological and ultrastructural changes in tobacco BY-2 cells exposed to microcystin-RR.

PubMed

Huang, Wenmin; Xing, Wei; Li, Dunhai; Liu, Yongding

2009-08-01

Tobacco BY-2 cells were exposed to microcystin-RR (MC-RR) at two concentrations, 60 microg mL(-1) and 120 microg mL(-1), to study the changes in morphology and ultrastructure of cells as a result of the exposure. Exposure to the lower concentration for 5 d led to typical apoptotic morphological changes including condensation of nuclear chromatin, creation of a characteristic 'half moon' structure, and cytoplasm shrinkage and decreased cell volume, as revealed through light microscopy, fluorescence microscopy, and transmission electron microscopy, respectively. Exposure to the higher concentration, on the other hand, led to morphological and ultrastructural changes typical of necrosis, such as rupture of the plasma membrane and the nuclear membrane and a marked swelling of cells. The presence of many vacuoles containing unusual deposits points to the involvement of vacuoles in detoxifying MC-RR. Results of the present study indicate that exposure of tobacco BY-2 cells to MC-RR at a lower concentration (60 microg mL(-1)) results in apoptosis and that to a higher concentration (120 microg mL(-1)), in necrosis.

Exciton antennas and concentrators from core-shell and corrugated carbon nanotube filaments of homogeneous composition.

PubMed

Han, Jae-Hee; Paulus, Geraldine L C; Maruyama, Ryuichiro; Heller, Daniel A; Kim, Woo-Jae; Barone, Paul W; Lee, Chang Young; Choi, Jong Hyun; Ham, Moon-Ho; Song, Changsik; Fantini, C; Strano, Michael S

2010-10-01

There has been renewed interest in solar concentrators and optical antennas for improvements in photovoltaic energy harvesting and new optoelectronic devices. In this work, we dielectrophoretically assemble single-walled carbon nanotubes (SWNTs) of homogeneous composition into aligned filaments that can exchange excitation energy, concentrating it to the centre of core-shell structures with radial gradients in the optical bandgap. We find an unusually sharp, reversible decay in photoemission that occurs as such filaments are cycled from ambient temperature to only 357 K, attributed to the strongly temperature-dependent second-order Auger process. Core-shell structures consisting of annular shells of mostly (6,5) SWNTs (E(g)=1.21 eV) and cores with bandgaps smaller than those of the shell (E(g)=1.17 eV (7,5)-0.98 eV (8,7)) demonstrate the concentration concept: broadband absorption in the ultraviolet-near-infrared wavelength regime provides quasi-singular photoemission at the (8,7) SWNTs. This approach demonstrates the potential of specifically designed collections of nanotubes to manipulate and concentrate excitons in unique ways.

Novel technique to suppress hydrocarbon contamination for high accuracy determination of carbon content in steel by FE-EPMA

PubMed Central

Yamashita, Takako; Tanaka, Yuji; Yagoshi, Masayasu; Ishida, Kiyohito

2016-01-01

In multiphase steels, control of the carbon contents in the respective phases is the most important factor in alloy design for achieving high strength and high ductility. However, it is unusually difficult to determine the carbon contents in multiphase structures with high accuracy by electron probe microanalysis (EPMA) due to the unavoidable effect of hydrocarbon contamination during measurements. We have investigated new methods for suppressing hydrocarbon contamination during field emission (FE) EPMA measurements as well as a conventional liquid nitrogen trap. Plasma cleaner inside the specimen chamber results in a improvement of carbon-content determination by point analysis, increasing precision tenfold from the previous 0.1 mass%C to 0.01 mass%C. Stage heating at about 100 °C dramatically suppresses contamination growth during continuous point measurement and mapping. By the combination of above two techniques, we successfully visualized the two-dimensional carbon distribution in a dual-phase steel. It was also noted that the carbon concentrations at the ferrite/martensite interfaces were not the same across all interfaces, and local variation was observed. The developed technique is expected to be a powerful tool for understanding the mechanisms of mechanical properties and microstructural evolution, thereby contributing to the design of new steel products with superior properties. PMID:27431281

Purification of white spot syndrome virus by iodixanol density gradient centrifugation.

PubMed

Dantas-Lima, J J; Corteel, M; Cornelissen, M; Bossier, P; Sorgeloos, P; Nauwynck, H J

2013-10-01

Up to now, only a few brief procedures for purifying white spot syndrome virus (WSSV) have been described. They were mainly based on sucrose, NaBr and CsCl density gradient centrifugation. This work describes for the first time the purification of WSSV through iodixanol density gradients, using virus isolated from infected tissues and haemolymph of Penaeus vannamei (Boone). The purification from tissues included a concentration step by centrifugation (2.5 h at 60,000 g) onto a 50% iodixanol cushion and a purification step by centrifugation (3 h at 80,000 g) through a discontinuous iodixanol gradient (phosphate-buffered saline, 5%, 10%, 15% and 20%). The purification from infected haemolymph enclosed a dialysis step with a membrane of 1,000 kDa (18 h) and a purification step through the earlier iodixanol gradient. The gradients were collected in fractions and analysed. The number of particles, infectivity titre (in vivo), total protein and viral protein content were evaluated. The purification from infected tissues gave WSSV suspensions with a very high infectivity and an acceptable purity, while virus purified from haemolymph had a high infectivity and a very high purity. Additionally, it was observed that WSSV has an unusually low buoyant density and that it is very sensitive to high external pressures. © 2013 John Wiley & Sons Ltd.

Direct high-pressure NMR observation of dipicolinic acid leaking from bacterial spore: A crucial step for thermal inactivation.

PubMed

Akasaka, Kazuyuki; Maeno, Akihiro; Yamazaki, Akira

2017-12-01

A bacterial spore protects itself with an unusually high concentration (~10% in dry weight of spore) of dipicolinic acid (DPA), the release of which is considered the crucial step for inactivating it under mild pressure and temperature conditions. However, the process of how the spore releases DPA in response to pressure remains obscure. Here we apply 1 H high-resolution high-pressure NMR spectroscopy, for the first time, to the spore suspension of Bacillus subtilis natto and monitor directly and in real-time the leaking process of DPA in response to pressure of 200MPa at 20°C. We find that about one third of the total DPA leaks immediately upon applying pressure, but that the rest leaks slowly in hrs upon decreasing the pressure. Once DPA is fully released from the spore, the proteins of the spore become easily denatured at a mild temperature, e.g., 80°C, much below the temperature commonly used to inactivate spores (121°C). The success of the present experiment opens a new avenue for studying bacterial spores and cells at the molecular level in response to pressure, temperature and other perturbations. Copyright © 2017 Elsevier B.V. All rights reserved.

High-Silica Lamoose Rock

NASA Image and Video Library

2015-07-23

A rock fragment dubbed "Lamoose" is shown in this picture taken by the Mars Hand Lens Imager (MAHLI) on NASA's Curiosity rover. Like other nearby rocks in a portion of the "Marias Pass" area of Mt. Sharp, Mars, it has unusually high concentrations of silica. The high silica was first detected in the area by the Chemistry & Camera (ChemCam) laser spectrometer. This rock was targeted for follow-up study by the MAHLI and the arm-mounted Alpha Particle X-ray Spectrometer (APXS). Silica is a rock-forming compound containing silicon and oxygen, commonly found on Earth as quartz. High levels of silica could indicate ideal conditions for preserving ancient organic material, if present, so the science team wants to take a closer look. The rock is about 4 inches (10 centimeters) across. It is fine-grained, perhaps finely layered, and etched by the wind. The image was taken on the 1,041st Martian day, or sol, of the mission (July 11, 2015). MAHLI was built by Malin Space Science Systems, San Diego. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Science Laboratory Project for the NASA Science Mission Directorate, Washington. JPL designed and built the project's Curiosity rover. http://photojournal.jpl.nasa.gov/catalog/PIA19828

5 CFR 337.206 - Terminations, modifications, extensions, and reporting.

Code of Federal Regulations, 2010 CFR

2010-01-01

... advertised under the direct-hire authority, the number of qualified applicants, the specific qualification... assessment of the effectiveness of the authority in attracting employees with unusually high qualifications...

Lyme Disease Tests

MedlinePlus

... by the laboratory that performed your test to evaluate whether your results are "within normal limits." For ... causing Lyme borreliosis with unusually high spirochaetaemia: a descriptive study. The Lancet Infectious Diseases . Available online at ...

High PRF high current switch

DOEpatents

Moran, Stuart L.; Hutcherson, R. Kenneth

1990-03-27

A triggerable, high voltage, high current, spark gap switch for use in pu power systems. The device comprises a pair of electrodes in a high pressure hydrogen environment that is triggered by introducing an arc between one electrode and a trigger pin. Unusually high repetition rates may be obtained by undervolting the switch, i.e., operating the trigger at voltages much below the self-breakdown voltage of the device.

48 CFR 1332.114 - Unusual contract financing.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Unusual contract financing... CONTRACTING REQUIREMENTS CONTRACT FINANCING Non-Commercial Item Purchase Financing 1332.114 Unusual contract financing. The designee authorized to approve unusual contract financing arrangements is set forth in CAM...

48 CFR 32.114 - Unusual contract financing.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Unusual contract financing... CONTRACTING REQUIREMENTS CONTRACT FINANCING Non-Commercial Item Purchase Financing 32.114 Unusual contract financing. Any contract financing arrangement that deviates from this part is unusual contract financing...

48 CFR 432.114 - Unusual contract financing.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Unusual contract financing... CONTRACTING REQUIREMENTS CONTRACT FINANCING Non-Commercial Item Purchase Financing 432.114 Unusual contract financing. The HCA is authorized to approve unusual contract financing. The signed determination and finding...

Assembly processes under severe abiotic filtering: adaptation mechanisms of weed vegetation to the gradient of soil constraints.

PubMed

Nikolic, Nina; Böcker, Reinhard; Kostic-Kravljanac, Ljiljana; Nikolic, Miroslav

2014-01-01

Effects of soil on vegetation patterns are commonly obscured by other environmental factors; clear and general relationships are difficult to find. How would community assembly processes be affected by a substantial change in soil characteristics when all other relevant factors are held constant? In particular, can we identify some functional adaptations which would underpin such soil-induced vegetation response? Eastern Serbia: fields partially damaged by long-term and large-scale fluvial deposition of sulphidic waste from a Cu mine; subcontinental/submediterranean climate. We analysed the multivariate response of cereal weed assemblages (including biomass and foliar analyses) to a strong man-made soil gradient (from highly calcareous to highly acidic, nutrient-poor soils) over short distances (field scale). The soil gradient favoured a substitution of calcicoles by calcifuges, and an increase in abundance of pseudometallophytes, with preferences for Atlantic climate, broad geographical distribution, hemicryptophytic life form, adapted to low-nutrient and acidic soils, with lower concentrations of Ca, and very narrow range of Cu concentrations in leaves. The trends of abundance of the different ecological groups of indicator species along the soil gradient were systematically reflected in the maintenance of leaf P concentrations, and strong homeostasis in biomass N:P ratio. Using annual weed vegetation at the field scale as a fairly simple model, we demonstrated links between gradients in soil properties (pH, nutrient availability) and floristic composition that are normally encountered over large geographic distances. We showed that leaf nutrient status, in particular the maintenance of leaf P concentrations and strong homeostasis of biomass N:P ratio, underpinned a clear functional response of vegetation to mineral stress. These findings can help to understand assembly processes leading to unusual, novel combinations of species which are typically observed as a consequence of strong environmental filtering, as for instance on sites affected by industrial activities.

Assembly Processes under Severe Abiotic Filtering: Adaptation Mechanisms of Weed Vegetation to the Gradient of Soil Constraints

PubMed Central

Nikolic, Nina; Böcker, Reinhard; Kostic-Kravljanac, Ljiljana; Nikolic, Miroslav

2014-01-01

Questions Effects of soil on vegetation patterns are commonly obscured by other environmental factors; clear and general relationships are difficult to find. How would community assembly processes be affected by a substantial change in soil characteristics when all other relevant factors are held constant? In particular, can we identify some functional adaptations which would underpin such soil-induced vegetation response? Location Eastern Serbia: fields partially damaged by long-term and large-scale fluvial deposition of sulphidic waste from a Cu mine; subcontinental/submediterranean climate. Methods We analysed the multivariate response of cereal weed assemblages (including biomass and foliar analyses) to a strong man-made soil gradient (from highly calcareous to highly acidic, nutrient-poor soils) over short distances (field scale). Results The soil gradient favoured a substitution of calcicoles by calcifuges, and an increase in abundance of pseudometallophytes, with preferences for Atlantic climate, broad geographical distribution, hemicryptophytic life form, adapted to low-nutrient and acidic soils, with lower concentrations of Ca, and very narrow range of Cu concentrations in leaves. The trends of abundance of the different ecological groups of indicator species along the soil gradient were systematically reflected in the maintenance of leaf P concentrations, and strong homeostasis in biomass N:P ratio. Conclusion Using annual weed vegetation at the field scale as a fairly simple model, we demonstrated links between gradients in soil properties (pH, nutrient availability) and floristic composition that are normally encountered over large geographic distances. We showed that leaf nutrient status, in particular the maintenance of leaf P concentrations and strong homeostasis of biomass N:P ratio, underpinned a clear functional response of vegetation to mineral stress. These findings can help to understand assembly processes leading to unusual, novel combinations of species which are typically observed as a consequence of strong environmental filtering, as for instance on sites affected by industrial activities. PMID:25474688

Honeybees Produce Millimolar Concentrations of Non-Neuronal Acetylcholine for Breeding: Possible Adverse Effects of Neonicotinoids.

PubMed

Wessler, Ignaz; Gärtner, Hedwig-Annabel; Michel-Schmidt, Rosmarie; Brochhausen, Christoph; Schmitz, Luise; Anspach, Laura; Grünewald, Bernd; Kirkpatrick, Charles James

2016-01-01

The worldwide use of neonicotinoid pesticides has caused concern on account of their involvement in the decline of bee populations, which are key pollinators in most ecosystems. Here we describe a role of non-neuronal acetylcholine (ACh) for breeding of Apis mellifera carnica and a so far unknown effect of neonicotinoids on non-target insects. Royal jelly or larval food are produced by the hypopharyngeal gland of nursing bees and contain unusually high ACh concentrations (4-8 mM). ACh is extremely well conserved in royal jelly or brood food because of the acidic pH of 4.0. This condition protects ACh from degradation thus ensuring delivery of intact ACh to larvae. Raising the pH to ≥5.5 and applying cholinesterase reduced the content of ACh substantially (by 75-90%) in larval food. When this manipulated brood was tested in artificial larval breeding experiments, the survival rate was higher with food supplemented by 100% with ACh (6 mM) than with food not supplemented with ACh. ACh release from the hypopharyngeal gland and its content in brood food declined by 80%, when honeybee colonies were exposed for 4 weeks to high concentrations of the neonicotinoids clothianidin (100 parts per billion [ppb]) or thiacloprid (8,800 ppb). Under these conditions the secretory cells of the gland were markedly damaged and brood development was severely compromised. Even field-relevant low concentrations of thiacloprid (200 ppb) or clothianidin (1 and 10 ppb) reduced ACh level in the brood food and showed initial adverse effects on brood development. Our findings indicate a hitherto unknown target of neonicotinoids to induce adverse effects on non-neuronal ACh which should be considered when re-assessing the environmental risks of these compounds. To our knowledge this is a new biological mechanism, and we suggest that, in addition to their well documented neurotoxic effects, neonicotinoids may contribute to honeybee colony losses consecutive to a reduction of the ACh content in the brood food.

Paleolimnological assessment of riverine and atmospheric pathways and sources of metal deposition at a floodplain lake (Slave River Delta, Northwest Territories, Canada).

PubMed

MacDonald, Lauren A; Wiklund, Johan A; Elmes, Matthew C; Wolfe, Brent B; Hall, Roland I

2016-02-15

Growth of natural resource development in northern Canada has raised concerns about the effects on downstream aquatic ecosystems, but insufficient knowledge of pre-industrial baseline conditions continues to undermine ability of monitoring programs to distinguish industrial-derived contaminants from those supplied by natural processes. Here, we apply a novel paleolimnological approach to define pre-industrial baseline concentrations of 13 priority pollutant metals and vanadium and assess temporal changes, pathways and sources of these metals at a flood-prone lake (SD2) in the Slave River Delta (NWT, Canada) located ~500 km north of Alberta's oil sands development and ~140 km south of a former gold mine at Yellowknife, NWT. Results identify that metal concentrations, normalized to lithium concentration, are not elevated in sediments deposited during intervals of high flood influence or low flood influence since onset of oil sands development (post-1967) relative to the 1920-1967 baseline established at SD2. When compared to a previously defined baseline for the upstream Athabasca River, several metal-Li relations (Cd, Cr, Ni, Zn, V) in post-1967 sediments delivered by floodwaters appear to plot along a different trajectory, suggesting that the Peace and Slave River watersheds are important natural sources of metal deposition at the Slave River Delta. However, analysis revealed unusually high concentrations of As deposited during the 1950s, an interval of very low flood influence at SD2, which corresponded closely with emission history of the Giant Mine gold smelter indicating a legacy of far-field atmospheric pollution. Our study demonstrates the potential for paleolimnological characterization of baseline conditions and detection of pollution from multiple pathways in floodplain ecosystems, but that knowledge of paleohydrological conditions is essential for interpretation of contaminant profiles. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

Biliary Secretion of Quasi-Enveloped Human Hepatitis A Virus.

PubMed

Hirai-Yuki, Asuka; Hensley, Lucinda; Whitmire, Jason K; Lemon, Stanley M

2016-12-06

Hepatitis A virus (HAV) is an unusual picornavirus that is released from cells cloaked in host-derived membranes. These quasi-enveloped virions (eHAV) are the only particle type circulating in blood during infection, whereas only nonenveloped virions are shed in feces. The reason for this is uncertain. Hepatocytes, the only cell type known to support HAV replication in vivo, are highly polarized epithelial cells with basolateral membranes facing onto hepatic (blood) sinusoids and apical membranes abutting biliary canaliculi from which bile is secreted to the gut. To assess whether eHAV and nonenveloped virus egress from cells via vectorially distinct pathways, we studied infected polarized cultures of Caco-2 and HepG2-N6 cells. Most (>99%) progeny virions were released apically from Caco-2 cells, whereas basolateral (64%) versus apical (36%) release was more balanced with HepG2-N6 cells. Both apically and basolaterally released virions were predominantly enveloped, with no suggestion of differential vectorial release of eHAV versus naked virions. Basolateral to apical transcytosis of either particle type was minimal (<0.02%/h) in HepG2-N6 cells, arguing against this as a mechanism for differences in membrane envelopment of serum versus fecal virus. High concentrations of human bile acids converted eHAV to nonenveloped virions, whereas virus present in bile from HAV-infected Ifnar1 -/- Ifngr1 -/- and Mavs -/- mice banded over a range of densities extending from that of eHAV to that of nonenveloped virions. We conclude that nonenveloped virions shed in feces are derived from eHAV released across the canalicular membrane and stripped of membranes by the detergent action of bile acids within the proximal biliary canaliculus. HAV is a hepatotropic, fecally/orally transmitted picornavirus that can cause severe hepatitis in humans. Recent work reveals that it has an unusual life cycle. Virus is found in cell culture supernatant fluids in two mature, infectious forms: one wrapped in membranes (quasi-enveloped) and another that is nonenveloped. Membrane-wrapped virions circulate in blood during acute infection and are resistant to neutralizing antibodies, likely facilitating HAV dissemination within the liver. On the other hand, virus shed in feces is nonenveloped and highly stable, facilitating epidemic spread and transmission to naive hosts. Factors controlling the biogenesis of these two distinct forms of the virus in infected humans are not understood. Here we characterize vectorial release of quasi-enveloped virions from polarized epithelial cell cultures and provide evidence that bile acids strip membranes from eHAV following its secretion into the biliary tract. These results enhance our understanding of the life cycle of this unusual picornavirus. Copyright © 2016 Hirai-Yuki et al.

The role of hydrothermal processes in concentrating high-field strength elements in the Strange Lake peralkaline complex, northeastern Canada

NASA Astrophysics Data System (ADS)

Salvi, Stefano; Williams-Jones, Anthony E.

1996-06-01

The middle-Proterozoic peralkaline pluton at Strange Lake, Quebec/Labrador, comprises hypersolvus to subsolvus phases which are unusually enriched in Zr, Y, REEs, Nb, Be, and F, as exotic alkali and alkaline-earth silicate minerals. The highest concentrations of these elements are in subsolvus granite, which underwent intense low temperature (≤200°C) hydrothermal alteration involving hematization and the replacement of alkali high-field strength element (HFSE) minerals by calcic equivalents. This alteration is interpreted to have been caused by meteoric or formational waters. High temperature (≥ 350°C) alteration, attributed to orthomagmatic fluids, is evident in other parts of the subsolvus granite by the replacement of arfvedsonite by aegirine. Comparisons of the chemical compositions of fresh and altered rocks indicate that rocks subjected to high temperature alteration were chemically unaffected, except for depletion in Zr, Y, and HREEs. These elements were appreciably enriched in rocks that underwent low temperature alteration. Other elements affected by low temperature alteration include Ca and Mg, which were added and Na, which was removed. Available data on HFSE speciation in aqueous fluids and the chemistry of the pluton, suggest that the HFSEs were transported as fluoride complexes. If this was the case, the low temperature fluid could not have been responsible for HFSE transport, because the high concentration of Ca and low solubility of fluorite would have buffered F - activity to levels too low to permit significant complexation. We propose that HFSE mineralization and accompanying alteration were the result of mixing, in the apical parts of the pluton, of a F-rich, essentially Ca-free orthomagmatic fluid containing significant concentrations of HFSEs, with an externally derived meteoric-dominated fluid, enriched in Ca as a result of interaction with calc-silicate gneisses and gabbros. According to this interpretation, the latter fluid was responsible for the exchange of Ca for alkalis, mainly Na, in HFSE-rich minerals and, by sharply reducing F - activity in the mixed fluid through fluorite precipitation and/or increasing pH, destabilised the HFSE-fluoride complexes, causing deposition of HFSE-bearing minerals. An important implication of this study is that major HFSE enrichment may be restricted to those rare cases where F-rich, Ca-free, metal leaching environments and Ca-rich depositional environments are juxtaposed.

Unusually high genetic diversity in COI sequences of Chimarra obscura (Trichoptera: Philopotamidae)

EPA Science Inventory

Chimarra obscura (Walker 1852) is a philopotamid caddisfly found throughout much of North America. Using the COI DNA barcode locus, we have found unexpectedly high amounts of genetic diversity and distances within C. obscura. Of the approximately 150 specimens sampled, we have fo...

77 FR 54951 - Disadvantaged Business Enterprise: Program Implementation Modifications

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-06

... tension with one another, particularly when information collection can be viewed as burdensome to... payments, this approach could smooth out statistical anomalies (e.g., years with unusually high or... (particularly high valued assets), and more stringent guidelines for deposits of funds used to acquire the...

Magnetic field topology and chemical abundance distributions of the young, rapidly rotating, chemically peculiar star HR 5624

NASA Astrophysics Data System (ADS)

Kochukhov, O.; Silvester, J.; Bailey, J. D.; Landstreet, J. D.; Wade, G. A.

2017-09-01

Context. The young, rapidly rotating Bp star HR 5624 (HD 133880) shows an unusually strong non-sinusoidal variability of its longitudinal magnetic field. This behaviour was previously interpreted as the signature of an exceptionally strong, quadrupole-dominated surface magnetic field geometry. Aims: We studied the magnetic field structure and chemical abundance distributions of HR 5624 with the aim to verify the unusual quadrupolar nature of its magnetic field and to investigate correlations between the field topology and chemical spots. Methods: We analysed high-resolution, time series Stokes parameter spectra of HR 5624 with the help of a magnetic Doppler imaging inversion code based on detailed polarised radiative transfer modelling of the line profiles. Results: We refined the stellar parameters, revised the rotational period, and obtained new longitudinal magnetic field measurements. Our magnetic Doppler inversions reveal that the field structure of HR 5624 is considerably simpler and the field strength is much lower than proposed by previous studies. We find a maximum local field strength of 12 kG and a mean field strength of 4 kG, which is about a factor of three weaker than predicted by quadrupolar field models. Our model implies that overall large-scale field topology of HR 5624 is better described as a distorted, asymmetric dipole rather than an axisymmetric quadrupole. The chemical abundance maps of Mg, Si, Ti, Cr, Fe, and Nd obtained in our study are characterised by large-scale, high-contrast abundance patterns. These structures correlate weakly with the magnetic field geometry and, in particular, show no distinct element concentrations in the horizontal field regions predicted by theoretical atomic diffusion calculations. Conclusions: We conclude that the surface magnetic field topology of HR 5624 is not as unusual as previously proposed. Considering these results together with other recent magnetic mapping analyses of early-type stars suggests that predominantly quadrupolar magnetic field topologies, invoked to be present in a significant number of stars, probably do not exist in real stars. This finding agrees with an outcome of the MHD simulations of fossil field evolution in stably stratified stellar interiors. Based on observations collected at the European Southern Observatory, Chile (ESO programs 085.D-0296, 089.D-0383, 095.D-0194) and on observations obtained at the Canada-France-Hawaii Telescope (CFHT) which is operated by the National Research Council of Canada, the Institut National des Science de l'Univers of the Centre National de la Recherche Scientifique of France, and the University of Hawaii.

Petrology and geochemistry of the unbrecciated achondrite Northwest Africa 1240 (NWA 1240): an HED parent body impact melt

NASA Astrophysics Data System (ADS)

Barrat, J. A.; Jambon, A.; Bohn, M.; Blichert-Toft, J.; Sautter, V.; Göpel, C.; Gillet, Ph.; Boudouma, O.; Keller, F.

2003-10-01

NWA 1240 is an unusual eucrite recently recovered in Morocco as a single stone of 98 g. It is an unbrecciated greenish-brown rock nearly devoid of fusion crust. It displays porphyritic texture consisting of skeletal hollow low-Ca pyroxene phenocrysts set in a variolitic (fan-spherulitic) mesostasis of fine elongate pyroxene and plagioclase crystals. Minor phases are skeletal chromite, iron, silica, troilite, ilmenite and minute amounts of phosphate and fayalite. Pyroxenes are unequilibrated and show one of the widest ranges of composition so far described for a eucrite, from En 76.0Wo 1.9Fs 22.1 to compositions nearly devoid of Mg (unusual ferrosilite and Fe-augite symplectites and possibly pyroxferroite). Plagioclase crystals contain significant amounts of Fe and Mg, which are possibly controlled by the Ca(Mg,Fe 2+)Si 3O 8 plagioclase component. To discuss the potential effects of hot-desert weathering on NWA 1240, we have analyzed a series of Saharan eucrites (Agoult, Aoufous, Igdi, Smara, NWA 047 and NWA 049) and large aliquots (0.39 to 2.8 g) of eucrite falls (Bereba, Bouvante, Jonzac, Juvinas and Serra de Magé). These results indicate that among the elements we have determined, Pb, Ba and Sr are the most sensitive indicators of Saharan weathering. The bulk composition of NWA 1240 has been determined for 45 elements by ICP-AES and ICP-MS. The data show that the meteorite is not significantly weathered: its Pb concentration is very low; Ba and Sr concentrations are not anomalously high; the Th/U and Hf/Sm ratios are chondritic (Th/U = 3.65, Hf/Sm = 0.74). NWA 1240 is rich in MgO (10.4 wt%) and Cr 2O 3 (0.71 wt%), and displays striking similarities with cumulate eucrites, such as having similar incompatible trace element patterns and a significant positive Eu anomaly (Eu/Eu* = 1.37). The combination of fast cooling and cumulate eucrite-dominated composition suggests that NWA 1240 is not an igneous rock but rather an impact melt.

Vapor-rich Hydrothermal Fluid Migration Within Pumiceous Sediment in the Iheya North Knoll, Okinawa Trough

NASA Astrophysics Data System (ADS)

Ishibashi, J.; Suzuki, R.; Hamasaki, H.; Yamanaka, T.; Chiba, H.; Tsunogai, U.; Ijiri, A.; Nakagawa, S.; Nunoura, T.; Takai, K.; Kinoshita, M.; Ashi, J.

2007-12-01

The newly developed ROV NSS (Navigable Sampling System) enabled pin-point piston core sampling from the active hydrothermal field. In the Iheya North hydrothermal field in the mid-Okinawa Trough (27°47.5'N, 126°53.8'E, depth = 1000m), animal colonies are observed not only around the central mound structure (named as NBC) which discharges vigrously high temperature (T=311°C) clear fluid, but also as Calyptogena colony at 200m east from the NBC mound and as tube-worm colony at 250m southeast from the NBC mound. During Leg 3 of KY05-14 cruise (R/V Kaiyo of JAMSTEC) in Jan. 2005, fourn piston cores were successfully recovered with length from 65cm to 250cm. Surface sediments from the Calyptogena colony and the tube-worm colony were revealed as mainly composed of pumiceous sediment. Pore fluids from the Calyptogena Field showed unusual chemistry characterized as very low salinity (Cl=420mM), low Mg concentration, significantly lower Na/Cl ratio than seawater and high methane concentration, which suggests contribution of a vapor-rich hydrothermal component migrating within the pumice layer from the activity center. Moreover, decrease of SO4 accompanied by increase of alkalinity is notable even less than one meter depth below the seafloor. In situ sulfate reduction in the surface sediment caused by entrainment of the hydrothermal component would be a source of hydrogen sulfide that supports Calyptogena colony.

Early miocene bimodal volcanism, Northern Wilson Creek Range, Lincoln County, Nevada

USGS Publications Warehouse

Willis, J.B.; Willis, G.C.

1996-01-01

Early Miocene volcanism in the northern Wilson Creek Range, Lincoln County, Nevada, produced an interfingered sequence of high-silica rhyolite (greater than 74% SiO2) ash-flow tuffs, lava flows and dikes, and mafic lava flows. Three new potassium-argon ages range from 23.9 ?? 1.0 Ma to 22.6 ?? 1.2 Ma. The rocks are similar in composition, stratigraphic character, and age to the Blawn Formation, which is found in ranges to the east and southeast in Utah, and, therefore, are herein established as a western extension of the Blawn Formation. Miocene volcanism in the northern Wilson Creek Range began with the eruption of two geochemically similar, weakly evolved ash-flow tuff cooling units. The lower unit consists of crystal-poor, loosely welded, lapilli ash-flow tuffs, herein called the tuff member of Atlanta Summit. The upper unit consists of homogeneous, crystal-rich, moderately to densely welded ash-flow tuffs, herein called the tuff member of Rosencrans Peak. This unit is as much as 300 m thick and has a minimum eruptive volume of 6.5 km3, which is unusually voluminous for tuffs in the Blawn Formation. Thick, conspicuously flow-layered rhyolite lava flows were erupted penecontemporaneously with the tuffs. The rhyolite lava flows have a range of incompatible trace element concentrations, and some of them show an unusual mixing of aphyric and porphyritic magma. Small volumes of alkaline, vesicular, mafic flows containing 50 weight percent SiO2 and 2.3 weight percent K2O were extruded near the end of the rhyolite volcanic activity. The Blawn Formation records a shift in eruptive style and magmatic composition in the northern Wilson Creek Range. The Blawn was preceded by voluminous Oligocene eruptions of dominantly calc-alkaline orogenic magmas. The Blawn and younger volcanic rocks in the area are low-volume, bimodal suites of high-silica rhyolite tuffs and lava flows and mafic lava flows.

Workshop on Extraterrestrial Materials from Cold and Hot Deserts

NASA Technical Reports Server (NTRS)

Schultz, Ludolf (Editor); Franchi, Ian A. (Editor); Reid, Arch M. (Editor); Zolensky, Michael E. (Editor)

1999-01-01

Since 1969 expeditions from Japan, the United States, and European countries have recovered more than 20,000 meteorite specimens from remote ice fields of Antarctica. They represent approximately 4000-6000 distinct falls, more than all non-Antarctic meteorite falls and finds combined. Recently many meteorite specimens of a new "population" have become available: meteorites from hot deserts. It turned out that suitable surfaces in hot deserts, like the Sahara in Africa, the Nullarbor Plain in Western and South Australia, or desert high plains of the U.S. (e.g., Roosevelt County, New Mexico), contain relatively high meteorite concentrations. For example, the 1985 Catalog of Meteorites of the British Museum lists 20 meteorites from Algeria and Libya. Today, 1246 meteorites finds from these two countries have been published in MetBase 4.0. Four workshops in 1982, 1985, 1988, and 1989 have discussed the connections between Antarctic glaciology and Antarctic meteorites, and the differences between Antarctic meteorites and modern falls. In 1995, a workshop addressed differences between meteorites from Antarctica, hot deserts, and modem falls, and the implications of possible different parent populations, infall rates, and weathering processes. Since 1995 many more meteorites have been recovered from new areas of Antarctica and hot deserts around the world. Among these finds are several unusual and interesting specimens like lunar meteorites or SNCs of probable martian origin. The Annual Meeting of the Meteoritical Society took place in 1999 in Johannesburg, South Africa. As most of the recent desert finds originate from the Sahara, a special workshop was planned prior to this meeting in Africa. Topics discussed included micrometeorites, which have been collected in polar regions as well as directly in the upper atmosphere. The title "Workshop on Extraterrestrial Materials from Cold and Hot Deserts" was chosen and the following points were emphasized: (1) weathering processes, (2) terrestrial ages, (3) investigations of "unusual" meteorites, and (4) collection and curation.

Short-tailed shrews: Toxicity and residue relationships of DDT, dieldrin, and endrin

USGS Publications Warehouse

Blus, L.J.

1978-01-01

Experiments involving dietary toxicity and residue relationships of DDT, dieldrin, and endrin were conducted with short-tailed shrews. Dietary concentrations of DDT dissolved in vegetable oils were usually more toxic than diets containing comparable amounts of powdered DDT. Younger shrews, particularly females, were more tolerant of powdered DDT than older animals; yet, there were no conspicuous age differences in toxicity of DDT dissolved in oils. In comparison to other mammals, short-tailed shrews are not unusually sensitive to DDT, dieldrin, or endrin on the basis of two-week feeding tests. The influence of age and sex on toxicity of DDT, endrin, and dieldrin was sometimes more important than body weight. Of those shrews of the same age and sex that were fed the same dietary dosage, heavier shrews were more tolerant than lighter individuals; and, heavier shrews tended to lose a greater percentage of body weight before death. There was a range of 15 to 105 DDT equivalents in brains of shrews dying on dietary dosages of DDT. Six shrews fed a high level of DDT seemed to have unusual metabolite capabilities and died with apparent lethal levels of DDD in their brains. Levels of dieldrin in brains of shrews that died on a dietary dosage of dieldrin ranged from 3.7 to 12.6 ppm. In the rates of gain and loss experiments where shrews were given diets containing 400 ppm DDT or 50 ppm dieldrin up to 17 days, high residues were noted in tissues of shrews after two weeks on a contaminated diet and a few died at that time. After shrews were placed on clean food, it was determined that >50% of the dieldrin residues in carcass and brain were lost in 50% of residues of DDT and metabolites in brains after 2 weeks on clean food; males lost nearly 50% of residues in carcasses after two weeks on clean food compared with a loss of only 11% in females.

Temporal record of osmium concentrations and 187Os/188Os in organic-rich mudrocks: Implications for the osmium geochemical cycle and the use of osmium as a paleoceanographic tracer

NASA Astrophysics Data System (ADS)

Lu, Xinze; Kendall, Brian; Stein, Holly J.; Hannah, Judith L.

2017-11-01

We present a compilation of 192Os concentrations (representing non-radiogenic Os) and initial 187Os/188Os isotope ratios from organic-rich mudrocks (ORM) to explore the evolution of the Os geochemical cycle during the past three billion years. The initial 187Os/188Os isotope ratio of a Re-Os isochron regression for ORM constrains the local paleo-seawater 187Os/188Os, which is governed by the relative magnitudes of radiogenic Os (old continental crust) and unradiogenic Os (mantle, extraterrestrial, and juvenile/mafic/ultramafic crust) fluxes to seawater. A first-order increase in seawater 187Os/188Os ratios occurs from the Archean to the Phanerozoic, and may reflect a combination of increasing atmosphere-ocean oxygenation and weathering of progressively more radiogenic continental crust due to in-growth of 187Os from radioactive decay of 187Re. Superimposed on this long-term trend are shorter-term fluctuations in seawater 187Os/188Os ratios as a result of climate change, emplacement of large igneous provinces, bolide impacts, tectonic events, changes in seafloor spreading rates, and lithological changes in crustal terranes proximal to sites of ORM deposition. Ediacaran-Phanerozoic ORM have mildly higher 192Os concentrations overall compared with pre-Ediacaran Proterozoic ORM based on the mean and 95% confidence interval of 10,000 median values derived using a bootstrap analysis for each time bin (insufficient Archean data exist for robust statistical comparisons). However, there are two groups with anomalously high 192Os concentrations that are distinguished by their initial 187Os/188Os isotope ratios. Ediacaran-Cambrian ORM from South China have radiogenic initial 187Os/188Os, suggesting their high 192Os concentrations reflect proximal Os-rich crustal source(s), ultraslow sedimentation rates, and/or other unusual depositional conditions. In contrast, the unradiogenic initial 187Os/188Os and high 192Os concentrations of some Mesozoic ORM can be tied to emplacement of large igneous provinces. Excluding these two anomalous groups and repeating the bootstrap analysis, we find that, overall, the 192Os concentrations for the Ediacaran-Phanerozoic and pre-Ediacaran Proterozoic time bins are not significantly different. An improved understanding of Os geochemical behavior in modern environments is required before our compilation can be fully used to constrain the temporal evolution of the seawater Os reservoir.

Magmatic carbon dioxide emissions at Mammoth Mountain, California

USGS Publications Warehouse

Farrar, Christopher D.; Neil, John M.; Howle, James F.

1999-01-01

Carbon dioxide (CO2) of magmatic origin is seeping out of the ground in unusual quantities at several locations around the flanks of Mammoth Mountain, a dormant volcano in Eastern California. The most recent volcanic activity on Mammoth Mountain was steam eruptions about 600 years ago, but seismic swarms and long-period earthquakes over the past decade are evidence of an active magmatic system at depth. The CO2 emission probably began in 1990 but was not recognized until 1994. Seismic swarms and minor ground deformation during 1989, believed to be results of a shallow intrusion of magma beneath Mammoth Mountain, probably triggered the release of CO2, which persists in 1998. The CO2 gas is at ambient temperatures and emanates diffusely from the soil surface rather than flowing from distinct vents. The CO2 has collected in the soil by displacing air in the pore spaces and reaches concentrations of greater than 95 percent by volume in places. The total area affected by high CO2 concentrations and high CO2 flux from the soil surface was estimated at 60 hectares in 1997. Coniferous forest covering about 40 hectares has been killed by high CO2 concentrations in the root zone. In more than 300 soil-gas samples collected from depths of 0.5 to 2 m in 1995, CO2 concentrations ranged from background levels (less than 1 percent) to greater than 95 percent by volume. At 250 locations, CO2 flux was measured using a closed chamber in 1996; values, in grams per square meter per day, ranged from background (less than 25) to more than 30,000. On the basis of these data, the total emission of magmatic CO2 in 1996 is estimated to be about 530 megagrams per day. Concentrations of CO2 exceeding Occupational Safety and Health Administration standards have been measured in pits dug in soil and snow, in poorly ventilated buildings, and in below-ground valve-boxes around Mammoth Mountain. CO2 concentrations greater than 10 percent in poorly ventilated spaces are not uncommon on some parts of Mammoth Mountain. Humans and other animals exposed to CO2 concentrations greater than 10 percent could lose consciousness and die rapidly. With knowledge of the problem and reasonable caution, however, the health hazard to humans can be avoided. As noted earlier, the CO2 emission is related to magmatic activity at depth, but at present (1998) it does not portend an imminent volcanic eruption.

Rise and Persistence of Global M1T1 Clone of Streptococcus pyogenes

PubMed Central

Kotb, Malak

2008-01-01

The resurgence of severe invasive group A streptococcal infections in the 1980s is a typical example of the reemergence of an infectious disease. We found that this resurgence is a consequence of the diversification of particular strains of the bacteria. Among these strains is a highly virulent subclone of serotype M1T1 that has exhibited unusual epidemiologic features and virulence, unlike all other streptococcal strains. This clonal strain, commonly isolated from both noninvasive and invasive infection cases, is most frequently associated with severe invasive diseases. Because of its unusual prevalence, global spread, and increased virulence, we investigated the unique features that likely confer its unusual properties. In doing so, we found that the increased virulence of this clonal strain can be attributed to its diversification through phage mobilization and its ability to sense and adapt to different host environments; accordingly, the fittest members of this diverse bacterial community are selected to survive and invade host tissue. PMID:18826812

Unusual target site disruption by the rare-cutting HNH restriction endonuclease PacI

PubMed Central

Shen, Betty; Heiter, Daniel F.; Chan, Siu-Hong; Wang, Hua; Xu, Shuang-Yong; Morgan, Richard D.; Wilson, Geoffrey G.; Stoddard, Barry L.

2010-01-01

The crystal structure of the rare-cutting HNH restriction endonuclease PacI in complex with its eight base pair target recognition sequence 5'-TTAATTAA-3' has been determined to 1.9 Å resolution. The enzyme forms an extended homodimer, with each subunit containing two zinc-bound motifs surrounding a ββα-metal catalytic site. The latter is unusual in that a tyrosine residue likely initiates strand-cleavage. PacI dramatically distorts its target sequence from Watson-Crick duplex DNA basepairing, with every base separated from its original partner. Two bases on each strand are unpaired, four are engaged in non-canonical A:A and T:T base pairs, and the remaining two bases are matched with new Watson-Crick partners. This represents a highly unusual DNA binding mechanism for a restriction endonuclease, and implies that initial recognition of the target site might involve significantly different contacts from those visualized in the DNA-bound cocrystal structures. PMID:20541511

Unusual fentanyl patch administration.

PubMed

Thomas, Sandra; Winecker, Ruth; Pestaner, Joseph P

2008-06-01

Fentanyl is an extremely potent narcotic analgesic that is becoming more popular as a drug of abuse. Because of the unique way in which the drug is packaged and delivered, the potential for unusual methods of abuse exists. We report the first case of true fentanyl patch ingestion in the medical literature. Initially, though unusual, cases of fentanyl ingestion were thought to have been reported, but further investigation of the literature revealed that in other case reports the patches had been held in the mouth and chewed. Because no reports of swallowing the patch had been published, suicide was initially a strong consideration in this case; however, further investigation showed that the decedent and his brother enjoyed swallowing the patches for quick "highs." Cases such as these serve to remind medical examiners and law enforcement officials of the value of performing thorough death investigations by performing complete autopsies with toxicological testing and correlating with investigation information to form an opinion with regard to the cause and manner of death.

Unusual magnetoelectric memory and polarization reversal in the kagome staircase compound N i3V2O8

NASA Astrophysics Data System (ADS)

Liu, Y. J.; Wang, J. F.; He, Z. Z.; Lu, C. L.; Xia, Z. C.; Ouyang, Z. W.; Liu, C. B.; Chen, R.; Matsuo, A.; Kohama, Y.; Kindo, K.; Tokunaga, M.

2018-05-01

We study the electric polarization of the kagome staircase N i3V2O8 in magnetic fields up to 30 T and report a magnetoelectric memory effect controlled by bias electric fields. The explored ferroelectric phase in 19 -24 T is electrically controlled, whereas the ferroelectric phase in 2 -11 T exhibits unusual memory effects. We determine a characteristic critical magnetic field H3=11 T , below which strong memory exists and the polarization is frozen even in opposite bias fields. But when magnetic fields exceed H3, the frozen polarization is released and polarization reversal appears by tuning bias electric fields. We ascribe these phenomena to the pinning-depinning mechanism: nucleation and the accompanying pinning of chiral domain walls cooperatively induce the frozen behavior; the polarization reversal results from the depinning through the ferroelectrtic-to-paraelectric phase transition in high magnetic fields. Our experimental results reveal that the first-order phase transition plays an important role in these unusual memory effects.

Weird planets and odd relations: Atmospheric Circulation on Hot Jupiters

NASA Astrophysics Data System (ADS)

Zhang, Michael; Knutson, Heather; Kataria, Tiffany; Burrows, Adam; Fortney, Jonathan

2018-01-01

We extract phase curves from Spitzer photometry for the highly irradiated hot Jupiter WASP-33b and the unusually dense Saturn-mass planet HD 149026b. To do so, we develop a new variant of Pixel Level Decorrelation that is effective at removing intrapixel sensitivity variations for long observations (> 10 hours) where the position of the star can vary by a significant fraction of a pixel. Using this algorithm, we derive eclipse depths, phase amplitudes, and phase offsets for both planets at 3.6 um and 4.5 um. We use a simple toy model to show that WASP-33b's phase offset, albedo, and heat recirculation efficiency are largely similar to those of other hot Jupiters despite its very high irradiation. On the other hand, our fits for HD 149026b prefer a very high albedo and an unusually high recirculation efficiency. We also compare our results to predictions from GCM models, and find that while neither provide a good match to the data, the discrepancies for HD 149026b are unusually large. We speculate that this may be related to its high bulk metallicity, which could lead to enhanced atmospheric opacities and the formation of reflective cloud layers in localized regions of the atmosphere. We then place these two planets in a broader context by exploring relationships between the temperatures, albedos, efficiencies, and phase offsets of all planets with published thermal phase curves. We find a striking relationship between phase offset and irradiation temperature--the former dips with temperature until around 3300 K, and rises thereafter. Although some aspects of this trend are mirrored in GCM models, there are notable differences that provide important clues for future modeling efforts.

A Cesium Rare-Earth Silicate Cs3 RESi6 O15 (RE=Dy-Lu, Y, In): The Parent of an Unusual Structural Class Featuring a Remarkable 57 Å Unit Cell Axis.

PubMed

Terry, Rylan; Vinton, Daniel; McMillen, Colin D; Kolis, Joseph W

2018-02-19

The structure of Cs 3 RESi 6 O 15 , where RE=Dy-Lu, Y, In, is unusual in that it contains octahedrally coordinated rare-earth ions; their relative orientation dictates the structure, as they rotate about the c-axis supported by the cyclic Si 6 O 15 framework. The repeat unit of the rotation is eight units generating a very long (ca. 57 Å) unit cell axis. This unusual repeat unit is created by the structural flexibility of the hexasilicate ring, which is in turn affected by the size of the rare earth ion as well as the size of alkali ion residing within the silicate layers. Previous work showed for the smaller Sc 3+ ion, the rotation of the octahedra is not sufficient to achieve closure at an integral repeat unit and an incommensurate structure results. The products are prepared as large, high quality single crystals using a high-temperature (650 °C) hydrothermal method with CsOH and F - mineralizers. The presence of fluoride is essential to the formation of the product. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

A site-specific screening comparison of modeled and monitored air dispersion and deposition for perfluorooctanoate.

PubMed

Barton, Catherine A; Zarzecki, Charles J; Russell, Mark H

2010-04-01

This work assessed the usefulness of a current air quality model (American Meteorological Society/Environmental Protection Agency Regulatory Model [AERMOD]) for predicting air concentrations and deposition of perfluorooctanoate (PFO) near a manufacturing facility. Air quality models play an important role in providing information for verifying permitting conditions and for exposure assessment purposes. It is important to ensure traditional modeling approaches are applicable to perfluorinated compounds, which are known to have unusual properties. Measured field data were compared with modeling predictions to show that AERMOD adequately located the maximum air concentration in the study area, provided representative or conservative air concentration estimates, and demonstrated bias and scatter not significantly different than that reported for other compounds. Surface soil/grass concentrations resulting from modeled deposition flux also showed acceptable bias and scatter compared with measured concentrations of PFO in soil/grass samples. Errors in predictions of air concentrations or deposition may be best explained by meteorological input uncertainty and conservatism in the PRIME algorithm used to account for building downwash. In general, AERMOD was found to be a useful screening tool for modeling the dispersion and deposition of PFO in air near a manufacturing facility.

Northwest Africa 773: Lunar Mare Breccia with a Shallow-formed Olivine-Cumulate Component, Very-Low-Ti Heritage, and a KREEP Connection

NASA Technical Reports Server (NTRS)

Jolliff, B. L.; Korotev, R. L.; Zeigler, R. A.; Floss, C.; Haskin, L. A.

2003-01-01

Northwest Africa 773 is one of the more unusual lunar meteorites found in recent years because it contains a prominent clast lithology, which appears to be an olivine-rich cumulate and because it is a very-low-Ti (VLT) mare breccia with relatively high incompatible-trace-element concentrations and LREE/HREE enrichment. A lunar origin was verified by Fagan and coworkers on the basis of noble-gas contents, oxygen isotopes, and mineral compositions. Fagan et al. described two lithologies: (1) heterolithic impact breccia with a regolith component and (2) cumulus olivine gabbronorite. Here, we refer to these as the breccia (Bx) lithology and the olivine-cumulate (OC) lithology. The impact breccia components are predominantly volcanic (basaltic), and, in this context, the occurrence of the cumulus lithology is especially significant: is it related to the volcanic components or does it represent a deep-seated rock entrained by the basaltic magma as it rose to the surface? Elevated incompatible-element concentrations with more or less KREEP-like inter-element ratios and very-low-Ti concentrations distinguish both lithologies of this meteorite from Apollo mare basalts. Here, we summarize key compositional information (bulk and mineral), especially related to the OC lithology, to show that it formed at shallow depth and comes from a VLT ultramafic precursor that mixed with a KREEP-like trace-element component deep in the crust or upper mantle.

Thermal responses of Symbiodinium photosynthetic carbon assimilation

NASA Astrophysics Data System (ADS)

Oakley, Clinton A.; Schmidt, Gregory W.; Hopkinson, Brian M.

2014-06-01

The symbiosis between hermatypic corals and their dinoflagellate endosymbionts, genus Symbiodinium, is based on carbon exchange. This symbiosis is disrupted by thermally induced coral bleaching, a stress response in which the coral host expels its algal symbionts as they become physiologically impaired. The disruption of the dissolved inorganic carbon (DIC) supply or the thermal inactivation of Rubisco have been proposed as sites of initial thermal damage that leads to the bleaching response. Symbiodinium possesses a highly unusual Form II ribulose bisphosphate carboxylase/oxygenase (Rubisco), which exhibits a lower CO2:O2 specificity and may be more thermally unstable than the Form I Rubiscos of other algae and land plants. Components of the CO2 concentrating mechanism (CCM), which supplies inorganic carbon for photosynthesis, may also be temperature sensitive. Here, we examine the ability of four cultured Symbiodinium strains to acquire and fix DIC across a temperature gradient. Surprisingly, the half-saturation constant of photosynthesis with respect to DIC concentration ( K P), an index of CCM function, declined with increasing temperature in three of the four strains, indicating a greater potential for photosynthetic carbon acquisition at elevated temperatures. In the fourth strain, there was no effect of temperature on K P. Finding no evidence for thermal inhibition of the CCM, we conclude that CCM components are not likely to be the primary sites of thermal damage. Reduced photosynthetic quantum yields, a hallmark of thermal bleaching, were observed at low DIC concentrations, leaving open the possibility that reduced inorganic carbon availability is involved in bleaching.

Quasiparticle density of states, localization, and distributed disorder in the cuprate superconductors

NASA Astrophysics Data System (ADS)

Sulangi, Miguel Antonio; Zaanen, Jan

2018-04-01

We explore the effects of various kinds of random disorder on the quasiparticle density of states of two-dimensional d -wave superconductors using an exact real-space method, incorporating realistic details known about the cuprates. Random on-site energy and pointlike unitary impurity models are found to give rise to a vanishing DOS at the Fermi energy for narrow distributions and low concentrations, respectively, and lead to a finite, but suppressed, DOS at unrealistically large levels of disorder. Smooth disorder arising from impurities located away from the copper-oxide planes meanwhile gives rise to a finite DOS at realistic impurity concentrations. For the case of smooth disorder whose average potential is zero, a resonance is found at zero energy for the quasiparticle DOS at large impurity concentrations. We discuss the implications of these results on the computed low-temperature specific heat, the behavior of which we find is strongly affected by the amount of disorder present in the system. We also compute the localization length as a function of disorder strength for various types of disorder and find that intermediate- and high-energy states are quasiextended for low disorder, and that states near the Fermi energy are strongly localized and have a localization length that exhibits an unusual dependence on the amount of disorder. We comment on the origin of disorder in the cuprates and provide constraints on these based on known results from scanning tunneling spectroscopy and specific heat experiments.

Neon produced by solar cosmic rays in ordinary chondrites

NASA Astrophysics Data System (ADS)

Roth, Antoine S. G.; Trappitsch, Reto; Metzler, Knut; Hofmann, Beda A.; Leya, Ingo

2017-06-01

Solar-cosmic-ray-produced Ne (SCR-Ne), in the form of low cosmogenic 21Ne/22Ne ratios (21Ne/22Necos <0.8), is more likely to be found in rare meteorite classes, like Martian meteorites, than in ordinary chondrites. This may be the result of a sampling bias: SCR-Ne is better preserved in meteorites with small preatmospheric radii and these specimens are often only studied if they belong to unusual or rare classes. We measured He and Ne isotopic concentrations and nuclear tracks in 25 small unpaired ordinary chondrites from Oman. Most chondrites have been intensively heated during atmospheric entry as evidenced by the disturbed track records, the low 3He/21Ne ratios, the low 4He concentrations, and the high peak release temperatures. Concentration depth profiles indicate significant degassing; however, the Ne isotopes are mainly undisturbed. Remarkably, six chondrites have low 21Ne/22Necos in the range 0.711-0.805. Using a new physical model for the calculation of SCR production rates, we show that four of the chondrites contain up to 20% of SCR-Ne; they are analyzed in terms of preatmospheric sizes, cosmic ray exposure ages, mass ablation losses, and orbits. We conclude that SCR-Ne is preserved, regardless of the meteorite class, in specimens with small preatmospheric radii. Sampling bias explains the predominance of SCR-Ne in rare meteorites, although we cannot exclude that SCR-Ne is more common in Martian meteorites than it is in small ordinary chondrites.

High School Mathematics Teaching in the USA

ERIC Educational Resources Information Center

Sherman, Brian

2010-01-01

The United States of America is a large and diverse country; nevertheless, high schools have a lot in common across the nation. In particular, mathematics teaching in American high schools, while not stereotyped, has some accepted norms which would be seen as unusual here in Australia. In order for the Australians to learn from the Americans, as…

The role of lecithin degradation on the pH dependent stability of halofantrine encapsulated fat nano-emulsions.

PubMed

Haidar, Iman; Harding, Ian H; Bowater, Ian C; Eldridge, Daniel S; Charman, William N

2017-08-07

We report on the successful incorporation of the antimalarial drug, halofantrine, into laboratory based soybean oil emulsions which were designed to mimic the commercially available parenteral fat emulsion, Intralipid ® . A high pH (minimum of pH 9, preferable pH of 11) was required for the drug laden emulsion to remain stable on storage and also to resist breaking under various stresses. Ageing of lecithin samples on storage was noted to result in degradation and a decrease in pH. We argue that this is the main reason for a similar decrease in pH for lecithin based emulsions and subsequent instability in drug laden emulsions. As expected, incorporation of the drug (halofantrine) resulted in lower stability. The (intensity weighted) particle size increased from 281nm for the drug free emulsion to 550nm following a loading of 1gL -1 of halofantrine, indicative of a lowering in stability and this was reflected in a shorter shelf life. Interestingly, incorporation of even higher concentrations of drug then resulted in better stability albeit never as stable as the drug free emulsion. We also report on unusual and complex surface tension behaviour for fresh lecithin where multiple critical concentration points were observed. Copyright © 2017 Elsevier B.V. All rights reserved.

Adhesion kinetics of viable Cryptosporidium parvum oocysts to quartz surfaces.

PubMed

Kuznar, Zachary A; Elimelech, Menachem

2004-12-15

The transport and deposition (adhesion) kinetics of viable Cryptosporidium parvum oocysts onto ultrapure quartz surfaces in a radial stagnation point flow system were investigated. Utilizing an optical microscope and an image-capturing device enabled real time observation of oocyst deposition behavior onto the quartz surface in solutions containing either monovalent (KCl) or divalent (CaCl2) salts. Results showed a significantly lower oocyst deposition rate in the presence of a monovalent salt compared to a divalent salt. With a monovalent salt, oocyst deposition rates and corresponding attachment efficiencies were relatively low, even at high KCl concentrations where Derjaguin-Landau-Verwey-Overbeek (DLVO) theory predicts the absence of an electrostatic energy barrier. On the other hand, in the presence of a divalent salt, oocyst deposition rates increased continuously as the salt concentration was increased over the entire range of ionic strengths investigated. The unusually low deposition rate in a monovalent salt solution is attributed to "electrosteric" repulsion between the Cryptosporidium oocyst and the quartz surface, most likely due to proteins on the oocyst surface that extend into the solution. It is further proposed that specific binding of calcium ions to the oocyst surface functional groups results in charge neutralization and conformational changes of surface proteins that significantly reduce electrosteric repulsion.

Mechanism behind the high thermoelectric power factor of SrTiO3 by calculating the transport coefficients

NASA Astrophysics Data System (ADS)

Shirai, Koun; Yamanaka, Kazunori

2013-02-01

The thermoelectric power factor of SrTiO3 is unusually high with respect to its mobility and band gap. Good thermoelectrics usually have high mobility and a narrow band gap, but such properties are not found in SrTiO3. We have determined the mechanism behind the high power factor by calculating the transport coefficients. The key to understanding the power factor is that different effective masses contribute to different transport phenomena. The discrepancy between the effective mass for the conductivity and the thermoelectric power showed that the conductivity and thermoelectric power are conveyed by electrons with different effective masses in the Brillouin zone. Light electrons were responsible for the high conductivity, whereas heavy electrons were responsible for the high thermoelectric power. The high carrier concentrations of more than 1020 cm-3 did not reduce the thermoelectric power of SrTiO3 above the classical limit. This indicates that the electrons carrying the thermoelectric power were not degenerate. This is achieved by a decrease in the Fermi energy and the contribution of the heavy electrons to the Seebeck coefficient. The strong dielectric screening also contributed to the high power factor. The Coulomb scattering by ionized impurities, which would usually reduce the carrier mobility, was effectively screened. These results clarify the mechanism behind the contribution of different types of electrons, and show that high thermoelectric power does not necessarily reduce conductivity. Our findings provide a new direction for the band engineering of thermoelectric materials.

An Alignment/Transfer Experiment with Low Socioeconomic Level Students.

ERIC Educational Resources Information Center

Elia, June Isaacs

1994-01-01

This study examined the amount of variance explained by alignment of testing to instruction among low socioeconomic level fourth graders, proposing two instructional alignment hypotheses. Results indicated that alignment had an unusually high effect. Low performing low socioeconomic level students achieved high success levels when conditions of…

Visual Neuroscience: A Retinal Ganglion Cell to Report Image Focus?

PubMed

Baden, Tom; Schaeffel, Frank; Berens, Philipp

2017-02-20

A recent study describes a mouse neuron projecting from the retina to the brain that exhibits exquisitely high sensitivity to high spatial frequency patterns presented over an unusually large receptive field: could this cell be a (de)focus detector? Copyright © 2017 Elsevier Ltd. All rights reserved.

A non-multimacrocyclic heteroditopic receptor that cooperatively binds and effectively extracts KAcO salt.

PubMed

Zakrzewski, Maciej; Kwietniewska, Natalia; Walczak, Wojciech; Piątek, Piotr

2018-06-06

Prepared in only three synthetic steps, a non-multimacrocyclic heteroditopic receptor binds potassium salts of halides and carboxylates with unusually high cooperativity, suggesting salt binding as associated ion-pairs. Unprecedented extraction of highly hydrophilic KAcO salt from water to organic solution is also demonstrated.

Using High-Precision Specific Gravity Measurements to Study Minerals in Undergraduate Geoscience Courses

ERIC Educational Resources Information Center

Brandriss, Mark E.

2010-01-01

This article describes ways to incorporate high-precision measurements of the specific gravities of minerals into undergraduate courses in mineralogy and physical geology. Most traditional undergraduate laboratory methods of measuring specific gravity are suitable only for unusually large samples, which severely limits their usefulness for student…

Textures in Utopia Planitia

NASA Image and Video Library

2002-12-20

In this image from NASA Mars Odyssey spacecraft, bizarre textures cover the surface of eastern Utopia Planitia, where there is a high probability that ground ice has played a role in the formation of this unusual landscape.

Gas-separation process

DOEpatents

Toy, Lora G.; Pinnau, Ingo; Baker, Richard W.

1994-01-01

A process for separating condensable organic components from gas streams. The process makes use of a membrane made from a polymer material that is glassy and that has an unusually high free volume within the polymer material.

High-pressure phase transitions of nitinol NiTi to a semiconductor with an unusual topological structure

NASA Astrophysics Data System (ADS)

Liu, Guangtao; Liu, Hanyu; Feng, Xiaolei; Redfern, Simon A. T.

2018-04-01

Systematic ab initio structure simulations have been used to explore the high-pressure behavior of nitinol (NiTi) at zero temperature. Our crystal structure prediction and first-principles calculations reveal that the known B 19 phase is dynamically unstable, and an orthorhombic structure (Pbcm) and a face-centered-cubic B 32 structure (F d 3 ¯m ) become stable above ˜4 and 29 GPa, respectively. The predicted, highest-pressure, B 32 phase is composed of two interpenetrating diamond structures, with a structural topology that is quite distinct from that of the other phases of NiTi. Interestingly, the B 32 phase shows an unusual semiconducting characteristic as a result of its unique band structure and the nature of 3 d orbitals localization, whose expected synthesis pressure is accessible to current experimental techniques.

Reconstructing the prevailing meteorological and optical environment during the time of the Titanic disaster

NASA Astrophysics Data System (ADS)

Basu, Sukanta; Nunalee, Christopher G.; He, Ping; Fiorino, Steven T.; Vorontsov, Mikhail A.

2014-10-01

In this paper, we reconstruct the meteorological and optical environment during the time of Titanic's disaster utilizing a state-of-the-art meteorological model, a ray-tracing code, and a unique public-domain dataset called the Twentieth Century Global Reanalysis. With high fidelity, our simulation captured the occurrence of an unusually high Arctic pressure system over the disaster site with calm wind. It also reproduced the movement of a polar cold front through the region bringing a rapid drop in air temperature. The simulated results also suggest that unusual meteorological conditions persisted several hours prior to the Titanic disaster which contributed to super-refraction and intermittent optical turbulence. However, according to the simulations, such anomalous conditions were not present at the time of the collision of Titanic with an iceberg.

An extreme anomaly in stratospheric ozone over Europe in 1940-1942

NASA Astrophysics Data System (ADS)

Brönnimann, S.; Luterbacher, J.; Staehelin, J.; Svendby, T. M.

2004-04-01

Reevaluated historical total ozone data reveal extraordinarily high values over several European sites in 1940-1942, concurrent with extreme climatic anomalies at the Earth's surface. Using historical radiosonde data, reconstructed upper-level fields, and total ozone data from Arosa (Switzerland), Dombås, and Tromsø (Norway), this unusual case of stratosphere-troposphere coupling is analyzed. At Arosa, numerous strong total ozone peaks in all seasons were due to unusually frequent upper troughs over central Europe and related ozone redistribution in the lower stratosphere. At the Norwegian sites, high winter total ozone was most likely caused by major stratospheric warmings in Jan./Feb. 1940, Feb./Mar. 1941, and Feb. 1942. Results demonstrate that the dynamically driven interannual variability of total ozone can be much larger than that estimated based on the past 25-40 years.

Highly deformable bones: unusual deformation mechanisms of seahorse armor.

PubMed

Porter, Michael M; Novitskaya, Ekaterina; Castro-Ceseña, Ana Bertha; Meyers, Marc A; McKittrick, Joanna

2013-06-01

Multifunctional materials and devices found in nature serve as inspiration for advanced synthetic materials, structures and robotics. Here, we elucidate the architecture and unusual deformation mechanisms of seahorse tails that provide prehension as well as protection against predators. The seahorse tail is composed of subdermal bony plates arranged in articulating ring-like segments that overlap for controlled ventral bending and twisting. The bony plates are highly deformable materials designed to slide past one another and buckle when compressed. This complex plate and segment motion, along with the unique hardness distribution and structural hierarchy of each plate, provide seahorses with joint flexibility while shielding them against impact and crushing. Mimicking seahorse armor may lead to novel bio-inspired technologies, such as flexible armor, fracture-resistant structures or prehensile robotics. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Aspiration cytology of mammary analogue secretory carcinoma of the salivary gland.

PubMed

Jung, Min Jung; Kim, Sang Yoon; Nam, Soon Yuhl; Roh, Jong-Lyel; Choi, Seung-Ho; Lee, Jeong Hyun; Baek, Jung Hwan; Cho, Kyung-Ja

2015-04-01

Aspiration cytologic findings of mammary analogue secretory carcinoma (MASC), a newly established salivary gland neoplasm defined by a t(12;15)(p13;q25) ETV6-NTRK3 translocation, are not fully characterized to date. We report cytologic descriptions of nine cases of molecularly confirmed MASC, including two with unusual findings. Aspiration smears from nine MASCs of the salivary glands were retrospectively reviewed and analyzed according to the cellular and structural features of the corresponding surgical specimens. Aspiration smears of MASC generally reflected the histologic diversity of the tumors. Among usual histologic findings, a micropapillary pattern was associated with a predominance of vacuolated individual cells on aspiration smears, a papillary-cystic pattern with a predominance of thin branching papillary structures, and a microcystic pattern with a predominance of irregular sheets of eosinophilic cells. There were two unusual cases, one with three-dimensional groups of high-grade atypical cells, and one with epithelial clusters floating in a notably mucinous background. These cases represented MASC with high-grade transformation and MASC with cystadenocarcinoma-like features, respectively. The secretory activity of MASC was not prominent in the aspiration specimens. Although unusual cases were present, most MASC cases showed characteristic cytologic findings, which could aid the cytologic diagnosis of MASC. And knowledge of the histologic spectrum of MASC, including high-grade transformation, could be valuable for cytological differential diagnoses of salivary gland tumors, and the management of patients with MASC. © 2014 Wiley Periodicals, Inc.

PM10-bound polycyclic aromatic hydrocarbons in Chiang Mai (Thailand): Seasonal variations, source identification, health risk assessment and their relationship to air-mass movement

NASA Astrophysics Data System (ADS)

Wiriya, Wan; Prapamontol, Tippawan; Chantara, Somporn

2013-04-01

This study aims to analyze the seasonal variations of PM10-bound polycyclic aromatic hydrocarbons (PAHs) for an estimation of the human health risk and identification of their possible sources. Ninety four PM10 samples were collected during the dry and wet seasons of 2010 and the dry season of 2011 in Chiang Mai, Thailand, and analyzed for 16 PAHs by gas chromatography-mass spectrometry. The average PM10 concentrations were 104.91 ± 32.70, 13.28 ± 11.34 and 36.24 ± 19.16 μg/m3 in dry season of 2010, wet season of 2010 and dry season of 2011, respectively, while the average 16-PAHs concentrations were 25.87 ± 10.13, 3.12 ± 2.18 and 4.58 ± 2.18 ng/m3, respectively. Correlations of PM10 and total PAHs concentrations were relatively high during all seasons (r > 0.796). In addition, PM10 concentrations were highly correlated with carcinogenic PAHs (r = 0.927) during the dry season of 2010, indicating that carcinogenic compounds were dominant in the particulate PAHs and could be generated from open burning, usually conducted in the dry season. The average PM10 concentration in the dry season of 2011 was much lower than that in 2010 and lower than the annual average of the past 12 years (48.17 μg/m3) because of the unusually high amount of rain precipitation and low open burning activity in this year. According to the accumulated number of hot spots occurring in northern part of Thailand, approximately 19,000 spots were found in the dry season of 2010, while only 6,600 spots were found in the dry season of 2011. It can be seen that larger scale open burning activities were performed in the dry season of 2010 than in the dry season of 2011. The value of toxicity equivalent concentration from PAHs in the dry season of 2010 was higher than that of the wet season of 2010 and the dry season of 2011. This is obviously related to concentrations of PM10 and PAHs. Diagnostic ratio and principal component analysis were used to find out the sources of PM10-bound PAHs. It was found that vehicle emission and biomass burning were the main sources of PM10 and PAHs in this area. The high ratio value of benzo(a)anthracene/chrysene (BaA/CHR) in the dry season of 2010 indicated possible photochemical processes and long distance emissions. Findings on source identification of PM10 and PAHs were found to be relevant to the direction and speed of air mass movement run by backward trajectory.

Uniportal anatomic combined unusual segmentectomies

PubMed Central

Lirio, Francisco; Sesma, Julio

2017-01-01

Nowadays, sublobar anatomic resections are gaining momentum as a valid alternative for early stage lung cancer. Despite being technically demanding, anatomic segmentectomies can be performed by uniportal video-assisted thoracic surgery (VATS) approach to combine the benefits of minimally invasiveness with the maximum lung sparing. This procedure can be even more complex if a combined resection of multiple segments from different lobes has to be done. Here we report five cases of combined and unusual segmentectomies done by the same experienced surgeon in high volume institutions to show uniportal VATS is a feasible approach for these complex resections and to share an excellent educational resource. PMID:29078653

Thyroid tuberculosis: presenting symptom of mediastinal tuberculous lymphadenitis--an unusual case.

PubMed

Chandanwale, Shirish S; Buch, Archana C; Vimal, Shruti S; Sachdeva, Punita

2014-01-01

Tuberculosis of thyroid gland is extremely rare. It spreads to thyroid by lymphogenous or heamatogenous route or from adjacent focus, either from larynx or cervical and mediastinal adenitis. We report an unusual case of a 33-year-old male with thyroid swelling. Fine needle aspiration (FNA) smears showed epithelioid cells without necrosis and acid fast bacilli (AFB). Subsequent investigation revealed mediastinal tuberculous lymphadenitis on Computerized Tomography (CT) scan. FNA confirmed the diagnosis of mediastinal tuberculous lymphadenitis. We conclude, when epithelioid cells are seen on FNA thyroid, tuberculosis must be ruled out especially in regions where there is high prevalence of tuberculosis.

A painful pulsatile abdominal mass in a young man with elevated blood pressures: an unusual presentation of phaeochromocytoma.

PubMed

Lee, B M K; Ti, L K

2002-08-01

We report an unusual presentation of phaeochromocytoma in a young man with a painful, pulsatile abdominal mass and elevated blood pressures. This led to a delay in diagnosis and resulted in the administration of triggers of catecholamine release, possibly causing a catecholamine surge. This caused the development of catecholamine-induced cardiomyopathy and multiple organ failure, requiring inotropic and ventilatory support, intra-aortic balloon pump and dialysis. Fortunately, his condition reversed with supportive treatment and alpha-adrenergic blockade. This illustrates the importance of having a high index of suspicion of phaeochromocytoma, especially in young patients with elevated blood pressures.

myBlackBox: Blackbox Mobile Cloud Systems for Personalized Unusual Event Detection.

PubMed

Ahn, Junho; Han, Richard

2016-05-23

We demonstrate the feasibility of constructing a novel and practical real-world mobile cloud system, called myBlackBox, that efficiently fuses multimodal smartphone sensor data to identify and log unusual personal events in mobile users' daily lives. The system incorporates a hybrid architectural design that combines unsupervised classification of audio, accelerometer and location data with supervised joint fusion classification to achieve high accuracy, customization, convenience and scalability. We show the feasibility of myBlackBox by implementing and evaluating this end-to-end system that combines Android smartphones with cloud servers, deployed for 15 users over a one-month period.

myBlackBox: Blackbox Mobile Cloud Systems for Personalized Unusual Event Detection

PubMed Central

Ahn, Junho; Han, Richard

2016-01-01

We demonstrate the feasibility of constructing a novel and practical real-world mobile cloud system, called myBlackBox, that efficiently fuses multimodal smartphone sensor data to identify and log unusual personal events in mobile users’ daily lives. The system incorporates a hybrid architectural design that combines unsupervised classification of audio, accelerometer and location data with supervised joint fusion classification to achieve high accuracy, customization, convenience and scalability. We show the feasibility of myBlackBox by implementing and evaluating this end-to-end system that combines Android smartphones with cloud servers, deployed for 15 users over a one-month period. PMID:27223292

An unusual case of intraorbital foreign body and its management

PubMed Central

Mukherjee, Bipasha; Goel, Shubhra; Subramanian, Nirmala

2011-01-01

Intraorbital foreign bodies are usually the result of accidental trauma and can lead to considerable morbidity. We report an unusual case of an industrial injury in a plastic manufacuring unit wherein hot molten plastic splashed and solidified inside the orbit. The resultant increased intraorbital pressure led to loss of vision in that eye. The extreme temperature of the foreign body caused extensive thermal damage to the surrounding adnexal structures. Staged reconstructive surgery was undertaken to repair the damage, with an acceptable final cosmetic outcome. Employment of protective eye wear to prevent such accidents in high-risk occupations should be made mandatory. PMID:21157077

Unusual Carrier Thermalization in a Dilute GaAs1-xNx Alloy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tan, P. H.; Xu, Z. Y.; Luo, X. D.

2007-01-01

Photoluminescence (PL) properties of the E{sub 0}, E{sub 0} + {Delta}{sub 0}, and E{sub +} bands in an x=0.62% GaAs{sub 1-x}N{sub x} alloy were investigated in detail, including their peak position, linewidth, and line shape dependences on the excitation energy, excitation power, and temperature, using micro-PL. The hot electrons within the E{sub +} band are found to exhibit highly unusual thermalization, which results in a large blueshift in its PL peak energy by >2k{sub B}T, suggesting peculiar density of states and carrier dynamics of the E{sub +} band.

An analysis of high fine aerosol loading episodes in north-central Spain in the summer 2013 - Impact of Canadian biomass burning episode and local emissions

NASA Astrophysics Data System (ADS)

Burgos, M. A.; Mateos, D.; Cachorro, V. E.; Toledano, C.; de Frutos, A. M.; Calle, A.; Herguedas, A.; Marcos, J. L.

2018-07-01

This work presents an evaluation of a surprising and unusual high turbidity summer period in 2013 recorded in the north-central Iberian Peninsula (IP). The study is made up of three main pollution episodes characterized by very high aerosol optical depth (AOD) values with the presence of fine aerosol particles: the strongest long-range transport Canadian Biomass Burning (BB) event recorded, one of the longest-lasting European Anthropogenic (A) episodes and an extremely strong regional BB. The Canadian BB episode was unusually strong with maximum values of AOD(440 nm) ∼ 0.8, giving rise to the highest value recorded by photometer data in the IP with a clearly established Canadian origin. The anthropogenic pollution episode originated in Europe is mainly a consequence of the strong impact of Canadian BB events over north-central Europe. As regards the local episode, a forest fire in the nature reserve near the Duero River (north-central IP) impacted on the population over 200 km away from its source. These three episodes exhibited fingerprints in different aerosol columnar properties retrieved by sun-photometers of the AErosol RObotic NETwork (AERONET) as well as in particle mass surface concentrations, PMx, measured by the European Monitoring and Evaluation Programme (EMEP). Main statistics, time series and scatterplots relate aerosol loads (aerosol optical depth, AOD and particulate matter, PM) with aerosol size quantities (Ångström Exponent and PM ratio). More detailed microphysical/optical properties retrieved by AERONET inversion products are analysed in depth to describe these events: contribution of fine and coarse particles to AOD and its ratio (the fine mode fraction), volume particle size distribution, fine volume fraction, effective radius, sphericity fraction, single scattering albedo and absorption optical depth. Due to its relevance in climate studies, the aerosol radiative effect has been quantified for the top and bottom of the atmosphere, obtaining mean daily values for this extraordinary summer period of -14.5 and -47.5 Wm-2, respectively.